Learning the proper techniques and methods for doing something enables desired results to be achieved in a timely manner, promotes safety, minimizes risks, and increases self-confidence. This month, we are answering questions to equip you with the necessary expertise for you to tackle challenges and be successful!
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: During hydrant flow testing, where would residual pressure be measured?
A:During hydrant flow testing, residual pressure is typically measured at two specific locations:
Hydrant Outlet: Residual pressure is measured directly at the outlet of the hydrant being tested. A pressure gauge is connected to the hydrant outlet, and the reading obtained represents the residual pressure at that particular hydrant. This measurement provides information about the pressure available at the specific location where the hydrant is situated.
Hydrant Pitot Gauge: A pitot gauge is a specialized device used to measure the water velocity at a specific point in the flow stream. During hydrant flow testing, a pitot gauge is inserted into the water stream coming out of the hydrant nozzle. By measuring the velocity, it is possible to calculate the residual pressure using Bernoulli's equation. This measurement provides an accurate representation of the pressure at the hydrant outlet, taking into account the flow velocity.
Both these measurements are important in determining the available pressure and water flow characteristics of a hydrant. The residual pressure readings help evaluate the performance of the water distribution system, assess the firefighting capabilities, and ensure compliance with standards and regulations.
Q: How is the chlorine gas feed rate usually controlled?
A: The chlorine gas feed rate is typically controlled using a variety of methods, depending on the specific system and application. Here are some common methods used to control the feed rate of chlorine gas:
Chlorinator/Feed System: Chlorinators are devices specifically designed to introduce chlorine gas into a water treatment system. They typically consist of a gas control valve and a flow meter. The gas control valve regulates the flow of chlorine gas, while the flow meter measures the rate of gas flow. By adjusting the gas control valve, operators can control the feed rate of chlorine gas into the water treatment process.
Gas Pressure Regulators: Gas pressure regulators are used to control the pressure of chlorine gas in the supply line. By adjusting the regulator, operators can indirectly control the feed rate of chlorine gas. Lowering the pressure reduces the flow rate, while increasing the pressure increases the flow rate.
Flow Control Valves: Flow control valves can be installed in the chlorine gas supply line to regulate the feed rate. These valves are typically manually operated and can be adjusted to control the flow of chlorine gas. By changing the valve position, the flow rate can be increased or decreased.
Automatic Control Systems: In larger water treatment facilities, automatic control systems may be employed to regulate the chlorine gas feed rate. These systems use feedback from sensors and instruments to monitor and control the chlorine gas flow. The control system adjusts the gas flow based on setpoints and feedback signals, ensuring precise and consistent dosing.
pH/ORP Control: In some cases, the chlorine gas feed rate may be controlled based on pH (acidity/alkalinity) or ORP (oxidation-reduction potential) levels in the water being treated. A feedback loop is established where the pH or ORP is continuously monitored, and the chlorine gas feed rate is adjusted accordingly to maintain desired water quality parameters.
It is important to note that the precise method of chlorine gas feed rate control can vary depending on the specific system and regulatory requirements. Proper training, adherence to safety protocols, and compliance with applicable regulations are crucial when working with chlorine gas to ensure safe and effective disinfection.
Q:How can point-of-use (POU) devices be used to achieve compliance with a volatile organic chemical's maximum contaminant level (MCL or MAC)?
A: POU devices can be used to achieve compliance with an MCL or MAC for volatile organic chemicals (VOCs) in drinking water. POU devices can be employed for this purpose as filtration systems that are equipped with activated carbon filters, as they are commonly used to remove VOCs from water. Activated carbon has a high adsorption capacity for organic compounds, including VOCs. The water passes through the carbon filter, and the activated carbon traps and retains the VOCs, thereby reducing their concentration in the water. These filtration systems can be installed at individual taps or on specific water outlets, such as kitchen faucets or drinking water dispensers.
POU reverse osmosis (RO) systems are highly effective in removing a wide range of contaminants, including VOCs. In an RO system, water is forced through a semipermeable membrane, which blocks the passage of dissolved impurities, including VOC molecules. The purified water is collected, while the concentrated contaminants are flushed away. RO systems can be installed under the sink or at a specific water outlet to treat the water at the point of use.
POU distillation units are another method of removing VOCs from water. In this process, water is heated to generate steam, and then the steam is condensed to produce purified water. VOCs, being volatile, do not vaporize with the steam and remain behind in the distillation unit. Distillation units can be installed at individual taps or used to fill dedicated containers for drinking water.
POU adsorption cartridges, similar to activated carbon filters, can be used to remove VOCs from water. These cartridges contain adsorbent materials specifically designed to capture and retain VOC molecules. Water passes through the cartridge, and the VOCs are adsorbed onto the surface of the adsorbent material. These cartridges can be installed on specific taps or integrated into pitcher-style water filters.
Compliance with MCL or MAC for VOCs may require a combination of POU devices, source water treatment, or a comprehensive water treatment strategy tailored to the specific contaminant and regulatory requirements. Regular maintenance and replacement of filter cartridges or membranes is essential to ensure the continued effectiveness of POU devices in achieving compliance and providing safe drinking water. Consulting with water treatment professionals and adhering to local regulations and guidelines is recommended to determine the most appropriate approach for achieving compliance with each VOC's MCL or MAC.
Q:What can a major break in a water main assist the distribution operator to do?
A: A major break in a water main, while an undesirable event, can assist the distribution operator in assessing system vulnerabilities. A major water main break can provide insights into the vulnerabilities of the distribution system, such as weak points or aging infrastructure. The distribution operator can use this information to conduct a thorough analysis, identify potential areas for improvement, and develop strategies to prevent similar incidents in the future.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
Backflow and backsiphonage pose potential risks to public health and to water quality. This is because they can contaminate potable water, damage water infrastructure (such as pipes and equipment), and have adverse effects on the environment. This month, we are answering questions about what backflow and backsiphonage are and devices to prevent them.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: What is backflow?
A:Backflow refers to the undesired reversal of the flow of water or other liquids, gases, or substances through a plumbing system. Normally, water flows in one direction through a plumbing system, from the water supply into the various fixtures and outlets in a building, and then out through the drainage system. However, under certain circumstances, backflow can occur, causing the reversal of this flow.
Backflow can happen due to a drop in water pressure in the main water supply, a sudden increase in downstream pressure, or a cross-connection between the potable (drinking) water supply and a contaminated source. When backflow occurs, it can potentially allow contaminants, such as chemicals, bacteria, or other substances, to enter the drinking water supply, posing a health risk to consumers.
To prevent backflow, plumbing systems are typically equipped with backflow prevention devices. These devices, such as check valves or backflow preventer assemblies, are designed to prevent the reversal of water flow and protect the potable water supply. They ensure that water can only flow in one direction, preventing any contaminants from entering the water supply.
Backflow prevention is crucial to maintaining the safety and quality of the drinking water supply, and it is regulated by plumbing codes and regulations in many jurisdictions. Regular inspections and maintenance of backflow prevention devices are necessary to ensure their proper functioning and prevent potential health hazards associated with backflow.
Q: What is backsiphonage?
A: Backsiphonage is a specific type of backflow that occurs when there is a sudden drop in water pressure in a plumbing system, causing a reverse flow of water. It happens when the pressure in the downstream side of the system becomes greater than the pressure in the upstream side, creating a vacuum or negative pressure.
Backsiphonage typically occurs when there is a significant demand for water downstream, such as during firefighting or when a large volume of water is being used simultaneously. This high demand causes a rapid drop in pressure, which can lead to backsiphonage if there are no adequate safeguards in place.
One common scenario where backsiphonage can occur is when a garden hose is submerged in a container of water or any other liquid. If the water supply pressure suddenly drops, for example, due to a water main break or a firefighting operation nearby, the lowered pressure can cause the water in the container to be siphoned back into the plumbing system, potentially contaminating the potable water supply.
To prevent backsiphonage, plumbing systems are equipped with backflow prevention devices, such as vacuum breakers or atmospheric vacuum breakers. These devices allow air to enter the plumbing system if there is a drop in pressure, breaking the siphoning action and preventing the reverse flow of water.
Backsiphonage poses a risk to the quality and safety of the drinking water supply, as it can allow contaminants or non-potable water to enter the plumbing system. Proper installation and maintenance of backflow prevention devices are essential in preventing backsiphonage and ensuring the integrity of the potable water supply.
Q:What is an approved device to prevent backflow and backsiphonage?
A: There are several types of approved devices used to prevent both backflow and backsiphonage in plumbing systems. The specific device required depends on the level of hazard and the local plumbing codes and regulations. Here are some commonly used backflow prevention devices:
Air Gap: An air gap is the most effective and reliable method for preventing backflow and backsiphonage. It is a physical gap or space between the water supply outlet and any potential source of contamination. The gap ensures that there is no direct connection between the potable water supply and the potential contaminant source.
Double Check Valve Assembly (DCVA): A DCVA consists of two independently operating check valves with a shutoff valve between them. It is designed to prevent backflow and backsiphonage in low to moderate hazard applications. DCVAs are commonly used in commercial and industrial settings.
Reduced Pressure Zone Assembly (RPZ): An RPZ assembly provides a higher level of protection and is suitable for high hazard applications. It includes two independently operating check valves with a pressure-reducing valve and a relief valve between them. The RPZ assembly ensures that if backflow occurs, it is contained within the assembly and cannot contaminate the potable water supply.
Pressure Vacuum Breaker (PVB): A PVB is a mechanical backflow prevention device that includes a check valve and an air inlet valve. It is commonly used in residential and irrigation systems to prevent backsiphonage. When there is a drop in pressure, the air inlet valve opens, allowing air to enter and prevent the siphoning of water.
Atmospheric Vacuum Breaker (AVB): An AVB is a simple and cost-effective backflow prevention device commonly used in residential applications. It consists of a check valve and an air inlet valve. When water flow stops, the air inlet valve opens to break the siphoning action and prevent backflow.
It is important to note that the selection of a specific backflow prevention device should be based on local plumbing codes and regulations, as well as the level of hazard associated with the plumbing system. Certified and approved devices should always be used, and regular testing and maintenance of these devices is necessary to ensure their effectiveness.
Q:If a main that cannot be shut down for testing is to have a reduced pressure principal backflow preventer installed, what should be done?
A: If a main cannot be shut down for testing and you need to install a reduced pressure principal backflow preventer (RPZ), there are a few steps you can take:
Isolate the section: Determine whether it is possible to isolate the section of the main where the RPZ is to be installed. This can be done by closing valves upstream and downstream of the desired location. By isolating the section, you can minimize the impact on the overall system during the installation.
Temporary bypass: If isolation is not feasible or if you need to maintain water supply during the installation, consider setting up a temporary bypass. This involves installing a parallel line or temporary piping arrangement to divert water flow around the section where the RPZ will be installed. This allows you to maintain water service while working on the installation.
Notify stakeholders: Inform relevant stakeholders about the installation process and any potential temporary disruptions. This could include notifying water utility providers, customers, or any other parties affected by the installation.
Coordinate with professionals: Engage the services of certified plumbers, backflow prevention specialists, or professionals experienced in RPZ installation. They will ensure that the installation is carried out correctly, adhering to local regulations and best practices.
Follow manufacturer guidelines: Strictly adhere to the manufacturer's instructions and guidelines for installing the RPZ. This includes proper placement, orientation, and pipe sizing to ensure optimal performance and prevent any potential issues.
Post-installation testing: Once the RPZ is installed, schedule testing and certification by a qualified backflow prevention tester to ensure the device is functioning correctly and providing the required level of protection.
It is worth noting that the specific steps may vary depending on the details of your situation and local regulations. Consulting with professionals familiar with local codes and regulations is crucial to ensure compliance and the proper installation of the RPZ.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
Chlorine residuals in water can be in several different forms. This month, we are answering questions about the possible forms in which the residuals can be, why the residuals would be in hypochlorite form, and what to do if disinfection is incomplete because the chlorine residual is in hypochlorite form.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: In what forms can chlorine residuals be?
A:Chlorine residuals in water can exist in several different forms, depending on various factors such as pH, temperature, and the presence of other chemicals. The main forms of chlorine residuals include:
Hypochlorous Acid (HOCl): Hypochlorous acid is the primary form of chlorine residual that exhibits the highest disinfection efficacy. It is more effective at killing microorganisms compared to other forms. Hypochlorous acid predominates at lower pH values, typically below 7, where it is uncharged and can easily penetrate the cell walls of microorganisms.
Hypochlorite Ion (OCl-): Hypochlorite ions are formed when chlorine reacts with water, leading to the dissociation of hypochlorous acid. Hypochlorite ions are negatively charged and are more prevalent at higher pH values, typically above 7. While hypochlorite ions are less effective disinfectants than hypochlorous acid, they still contribute to the overall disinfection process.
Chlorine Gas (Cl2): Chlorine gas is the elemental form of chlorine used for disinfection purposes. It can be added to water in gaseous form, often in large-scale disinfection processes. Chlorine gas can dissolve in water, forming hypochlorous acid and hypochlorite ions, depending on the pH and other factors.
Combined Chlorine Compounds: When chlorine reacts with organic matter, such as ammonia or certain nitrogen-containing compounds, it can form combined chlorine compounds. The most common combined chlorine compound is chloramine (monochloramine), which consists of a chlorine atom bonded with an ammonia molecule (NH2Cl). Chloramines are often used as a secondary disinfectant in water treatment and distribution systems.
It is crucial to carefully monitor and manage the chlorine residuals to achieve the desired disinfection efficacy while complying with regulatory requirements and maintaining water quality standards.
Q: Why would the chlorine residual be in hypochlorite form?
A: The chlorine residual in water can exist in different forms depending on the disinfection process and the water conditions. One form of chlorine residual is in the hypochlorite form, typically as sodium hypochlorite (NaOCl). There are a few reasons why the chlorine residual may be present in this form:
Chlorine Disinfection Method: Sodium hypochlorite is commonly used as a disinfectant in water treatment processes. It is often added to water as a solution or through a chemical feed system to achieve disinfection. When sodium hypochlorite is introduced into water, it dissociates to release hypochlorous acid (HOCl) and hypochlorite ions (OCl-). These species are responsible for the disinfection process.
pH Influence: The presence of hypochlorous acid (HOCl) and hypochlorite ions (OCl-) in water depends on the pH level. Hypochlorous acid is more prevalent at lower pH values, while hypochlorite ions are dominant at higher pH values. At pH values commonly found in drinking water (around neutral or slightly basic), the hypochlorite ions (OCl-) are more stable and make up a significant portion of the chlorine residual.
Chlorine Stability: Hypochlorite ions (OCl-) are more stable and have a longer-lasting residual than hypochlorous acid (HOCl). This stability allows the hypochlorite form to persist in the water and to provide sustained disinfection effects over a longer period.
It is worth noting that the presence of the hypochlorite form in the chlorine residual does not necessarily imply any issues with water quality or disinfection effectiveness. Sodium hypochlorite and the resulting hypochlorite ions are widely used and recognized as effective disinfectants for water treatment purposes. The specific form of chlorine residual and its concentration must be carefully regulated to ensure safe and reliable disinfection of drinking water. However, hypochlorite ions are less reactive than hypochlorous acid and they penetrate the cell walls of microorganisms at a slower rate.
Q:If disinfection is incomplete because the chlorine residual is in hypochlorite form, what should you change to improve disinfection?
A: If disinfection is incomplete because the chlorine residual is primarily in the hypochlorite form, several changes can be made to improve disinfection efficacy:
Adjust pH levels: The effectiveness of chlorine as a disinfectant is influenced by pH. Hypochlorous acid (HOCl), the more effective disinfectant form of chlorine, dominates at lower pH levels, while hypochlorite ion (OCl-) is more prevalent at higher pH levels. To promote the formation of HOCl, the pH can be lowered by adding an acid, such as sulfuric acid or carbon dioxide, to the water. This adjustment can enhance disinfection efficiency.
Increase contact time: Increasing the contact time between the water and the disinfectant can enhance disinfection effectiveness. This can be achieved by slowing down the flow rate or by implementing a contact tank or reservoir where the water remains in contact with the disinfectant for an extended period.
Increase chlorine dosage: If the disinfection is inadequate, it may be necessary to increase the chlorine dosage. This can be achieved by adjusting the feed rate of the chlorine disinfectant or by using a more concentrated chlorine solution. However, it is important to consider the regulatory limits for chlorine levels and ensure they are not exceeded (and to remember that chlorination disinfection byproducts are formed when water is chlorinated and organic matter in the water reacts with chlorine, and chlorination disinfection byproducts can be carcinogenic).
Use alternative disinfectants: If achieving adequate disinfection with chlorine is challenging, it might be necessary to consider alternative disinfectants. Chlorine dioxide, ozone, or ultraviolet (UV) disinfection are examples of alternative disinfection methods that can be effective in situations where chlorine is not achieving the desired results. Each alternative method has its own advantages, limitations, and operational considerations that need to be evaluated.
It is crucial to consult with water treatment professionals, engineers, or local regulatory authorities to determine the most appropriate course of action for improving disinfection in your specific water treatment system. They can provide guidance based on the water quality parameters, the system's design, and the regulatory requirements in your area.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
Best practices should be used in water treatment to ensure public health, comply with regulations, protect the environment, mitigate risks, and for optimal efficiency and continuous improvement.
We hope that you are having a great summer and that you are at the top of your water treatment game!
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: With which size meshed screen should the vent opening of an aerator be screened?
A:The size of the meshed screen for the vent opening of an aerator depends on the specific requirements of the system and the purpose of the screen. The primary goal is to prevent debris, insects, or small animals from entering the aerator while allowing adequate airflow.
The appropriate mesh size can vary depending on the location and the intended use of the aerator. In general, a mesh size between 1/4 inch (6.35 mm) and 1/2 inch (12.7 mm) is commonly used to provide effective protection while allowing sufficient ventilation. However, it is essential to consider factors such as the surrounding environment, the type of debris expected, and any specific regulations or guidelines applicable to your situation.
If you are unsure about the ideal mesh size for your aerator, you should consult the manufacturer's guidelines or contact a professional in the field who can provide specific recommendations based on your requirements and circumstances.
Q: At what point in the water treatment process should polyphosphates used to sequester (suspend) iron be injected?
A: Polyphosphates are commonly used in water treatment processes to sequester or suspend iron and prevent it from causing issues such as staining or precipitation. The specific point of injection for polyphosphates can vary depending on the water treatment system and the nature of the iron problem. However, a common practice is to inject polyphosphates before or during the coagulation and flocculation stage of the treatment process.
Coagulation and flocculation are typically employed to remove suspended particles and impurities from water. During this stage, a coagulant (such as alum or ferric chloride) is added to the water, which forms floc by binding to the suspended particles. Polyphosphates can be introduced alongside the coagulant or immediately after to sequester any iron present in the water and prevent its unwanted effects.
It is important to note that the exact dosage and injection point of polyphosphates may vary depending on factors such as the iron concentration, the pH level, and the water's temperature. To determine the optimal injection point and dosage, it is advisable to consult water treatment experts, engineers, or professionals who can analyze your water quality and system requirements.
Q:What must be used to protect a direct water connection to a boiler containing a scale prevention compound?
A: To protect a direct water connection to a boiler containing a scale prevention compound, a backflow preventer must be used. A backflow preventer is a device designed to prevent the reverse flow of water or substances from the boiler system back into the main water supply. This is crucial to safeguard the potable water supply from potential contamination.
In this specific scenario, where a scale prevention compound is present in the boiler, it is essential to ensure that the backflow preventer used is appropriate for the specific application and meets the necessary regulatory standards. The backflow preventer should be selected and installed according to local plumbing codes and regulations, as well as the specific requirements of the boiler system.
There are different types of backflow preventers available, such as reduced pressure zone (RPZ) valves, double-check valves, or pressure vacuum breakers. The choice of backflow preventer will depend on factors such as the local plumbing code requirements, the level of hazard posed by the scale prevention compound, and the specific needs of the boiler system.
Consulting with a qualified plumbing professional or engineer experienced in backflow prevention is strongly recommended to ensure the appropriate backflow preventer is selected, installed, and maintained correctly for protecting the direct water connection to the boiler containing the scale prevention compound.
Q:When installing service lines, what should be installed to provide for movement due to soil settling?
A: To accommodate movement due to soil settling when installing service lines, a flexible joint or expansion joint should be installed. These joints allow for slight movement and flexibility in the service lines, preventing damage or stress caused by soil settlement or other ground movements.
There are several types of joints commonly used for this purpose:
Mechanical couplings: Mechanical couplings are commonly used for connecting pipes in service line installations. They provide a flexible connection that allows for limited movement and helps compensate for soil settlement. These couplings typically consist of two halves that are bolted or clamped together, allowing for expansion and contraction.
Expansion joints: Expansion joints are specifically designed to absorb thermal expansion, contraction, and other movement in pipes. They consist of flexible materials, such as rubber or metal bellows, that can stretch or compress as needed. Expansion joints are particularly useful when there are significant temperature variations in the system or when long sections of pipe are involved.
Flexible connectors: Flexible connectors, such as flexible rubber or plastic connectors, are used to join sections of service lines. These connectors can accommodate minor movement due to soil settling and provide a degree of flexibility. They are commonly used in plumbing applications and can be effective for small-scale service line installations.
The choice of joint or connector will depend on factors such as the pipe material, the anticipated movement, and the specific requirements of the installation. It is crucial to consult local building codes and regulations, as well as professional plumbers or engineers, to ensure the appropriate jointing method is selected and installed correctly to allow for movement due to soil settling.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
Actions have consequences, sometimes these consequences are known but the action must be taken in any case. Other times, we are not sure what the consequences of an action will be. This month, we are discussing causes and effects.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: What can be the result of the sudden closure of a check valve?
A: The sudden closure of a check valve can have several potential outcomes depending on the specific circumstances and the characteristics of the system involved. It can result in a water hammer, which is when the sudden closure of a check valve can create a hydraulic shock wave in fluid systems, particularly those involving liquids like water. Water hammer occurs when the kinetic energy of the moving fluid is rapidly converted into pressure energy due to the abrupt stoppage of flow. This can result in a loud banging or hammering noise and cause significant pressure spikes within the system. Water hammer can lead to damage to pipes, fittings, valves, and other components if not properly controlled.
Even if a water hammer does not occur, there can be a pressure surge that can cause pressure fluctuations or damage to sensitive equipment or pipelines. Or, there can be vibration and stress that can affect the valve, nearby piping, and other connected equipment. These vibrations can result in fatigue failure or damage to the components if they exceed the design limits.
It is important to note that the exact consequences of a sudden check valve closure will depend on various factors, including the flow rate, system pressure, valve design, pipe material, and other specific conditions. Engineering practices, such as proper valve sizing, surge protection devices, and hydraulic modeling can help mitigate the potential negative effects of a sudden check valve closure.
Q: What can water that is high in sulfates cause?
A: Water that is high in sulfates can cause several issues and potential impacts. Here are some of the common effects associated with elevated sulfate levels in water:
Taste and Odour: Water with high sulfate concentrations may have an unpleasant taste, often described as bitter or salty. It can also contribute to a sulfurous or rotten egg-like odour, which is caused by the presence of hydrogen sulfide gas. These sensory qualities can make the water unpalatable and undesirable for consumption.
Laxative Effect: Consuming water with high sulfate levels can have a laxative effect on some individuals. This is particularly true for people who are not accustomed to sulfates or those with sensitivity to sulfate compounds. Ingesting water with high sulfate concentrations can lead to diarrhea or loose stools.
Corrosion: Sulfates in water can contribute to corrosion issues, especially in plumbing systems and appliances. High sulfate concentrations can react with metals, such as iron or steel, present in pipes, fixtures, and water-using appliances. This can result in the formation of sulfide compounds and accelerate the corrosion process, leading to pipe degradation, leaks, and potential damage to equipment.
Scaling and Fouling: Sulfates can also cause scaling and fouling in water systems. When water with high sulfate levels is heated, such as in boilers or water heaters, sulfates can precipitate and form deposits on surfaces. These deposits, commonly known as scale, can reduce the efficiency of heat transfer, restrict water flow, and decrease the lifespan of equipment.
Environmental Impact: Discharge of water with high sulfate concentrations into natural water bodies can have adverse effects on aquatic ecosystems. Sulfates can promote the growth of certain types of bacteria that produce hydrogen sulfide gas. Elevated hydrogen sulfide levels in water can be toxic to aquatic life, negatively impacting fish, invertebrates, and other organisms.
It is important to note that the specific impacts of high sulfate levels in water can vary depending on the concentration of sulfates, other water quality parameters, and individual sensitivities. Water treatment methods such as reverse osmosis, ion exchange, or activated carbon filtration can be employed to reduce sulfate levels and mitigate the associated issues if necessary.
Q:What can create heat that causes the metal strip in a normal electrical fuse to melt?
A: The metal strip in a normal electrical fuse, often made of a material like copper, aluminum, or an alloy, will melt from the heat caused by excessive current flowing through it. The primary purpose of a fuse is to protect electrical circuits and devices from damage or fire caused by overcurrent conditions.
When the current passing through a fuse exceeds its rated current capacity, the resistance of the metal strip generates heat due to the Joule heating effect. The heat generated is proportional to the square of the current and the resistance of the metal strip. As the current increases, the temperature of the metal strip rises until it reaches its melting point.
Once the temperature exceeds the melting point of the metal strip, the strip will melt or fuse, creating an open circuit. This melting or "blowing" of the fuse interrupts the flow of current, preventing further damage to the electrical system. The open circuit caused by the melted fuse indicates that a fault or excessive current condition occurred, signaling the need for investigation and repair before replacing the fuse.
The selection of a fuse with a specific current rating is critical to ensure that it can handle the expected normal operating current while providing adequate protection against overcurrent events. Choosing a fuse with a rating significantly lower than the expected operating current can cause nuisance tripping, while a rating significantly higher may not provide sufficient protection against excessive currents.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
As you likely know, reservoirs are used in water treatment plants to store treated water. This is necessary because consumer demand for water varies from hour to hour.
You might have heard the saying "The dose makes the poison." This is a quote from Paracelsus (a Swiss physician who was one of the first scientists to introduce chemistry to medicine). This is very true, as all things are poisons and nothing is without poison, it is only the dose that makes something not a poison. For example, even if the water is safe, drinkable water, if you drink too much water it can cause water intoxication (also known as water poisoning). This can result in hyponatremia (your blood sodium concentration becomes very low). If you drink more water than your kidneys can flush out, it will dilute the sodium in your bloodstream, causing cells to swell.
This month, we are discussing reservoirs and dosages.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: What is the main component of water that encourages algae growth in a reservoir?
A: Phosphorus is the main component of water that encourages algae growth in a reservoir. This is because phosphorus is an essential nutrient for plant growth, including algae. Therefore, when phosphorus is available in sufficient quantities in water, it can act as a nutrient for algae, promoting their growth and reproduction.
Q: What is the optimal dosage rate of fluoride in a potable drinking water system? Why is this the optimal dosage rate? Is there evidence that it is safe to add fluoride to drinking water?
A: The optimal dosage rate of fluoride is 0.7 mg/L. Fluoride is a naturally occurring mineral that can strengthen tooth enamel and make it more resistant to acid attacks from bacteria in the mouth, helping to prevent cavities. Excessive fluoride in water can cause fluorosis, a condition in which white spots form on tooth enamel (at 1.5 mg/L), and it can increase the risk of skeletal fluorosis (at 2.5 mg/L).
While water fluoridation is a very contentious topic, various research shows that countries that add fluoride to their drinking water have lower rates of tooth decay, and that it is both beneficial and safe as long as the optimal dosage rate is maintained. Community water fluoridation has been extensively studied and endorsed by reputable health organizations and agencies, including the World Health Organization (WHO), Health Canada, the Canadian Dental Association (CDA), the Canadian Medical Association (CMA), many of the provincial and territorial health authorities, and various public health agencies at the municipal, regional, and provincial levels.
Q:For which water treatment chemical is chemical feeder adjustment most critical because of potential toxicity?
A: Chlorine is widely used as a disinfectant of choice in many water treatment plants. However, the dosage rate of chlorine needs to be closely monitored, as chlorine can react with organic matter to create trihalomethanes (THMs).
Prolonged exposure and/or exposure to high levels of trihalomethanes can increase the risk of developing bladder or colorectal cancer.
Thank you to Delco Water for their help with this forum!
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
Workers want, and deserve, to work in a safe environment. Everyone wants to come home safe from work each day! Safety should always be a top priority.
This month, we are providing you with information about SDS and chemicals, as well as hearing protection.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: Why was Material Safety Data Sheets (MSDS) changed to Safety Data Sheets (SDS)? What is the difference between them?
A: MSDS was changed to SDS, effective June 1, 2015, as the SDS is a simpler, more consistent, and more effective way to communicate the hazards of chemicals. SDS follow the formatting of the United Nations' Globally Harmonized System of Classification and Labeling of Chemicals, also known as the GHS. Previously, MSDS could come in many different formats, depending on the organization.
SDS follows a standardized 16-section format, which includes information such as identification, hazard identification, composition, first-aid measures, firefighting measures, accidental release measures, handling and storage, and exposure controls. SDS also includes standardized hazard pictograms, signal words, and precautionary statements to convey hazard information in a clear and consistent manner.
Q: Is an SDS required for all chemicals, even those that are not dangerous? If so, why?
A: Anything that lacks physical and health hazards is not hazardous and, therefore, does not require an SDS. However, chemicals that are considered to be non-hazardous or minimally hazardous might still have potential risks associated with their handling, use, storage, or disposal. For example, there is an SDS for wheat flour as wheat flour dust is combustible and, under some circumstances, can form explosive clouds in the air. It is a good idea to have an SDS for each chemical that you have in your facility, regardless of their hazard classifications.
Q:To which employees must hearing protection be made available?
A: All employees who are or who will be exposed to noise that is at or above the occupational exposure limits (OEL) for noise must be provided with suitable hearing protection devices (HPDs), such as earplugs or earmuffs, and they must be trained on their proper use, maintenance, and limitations. The criterion level, often abbreviated as Lc, is the steady noise level permitted for a full eight-hour work shift. This is 85 dBA (adjusted decibels, based on a weighted scale for judging loudness that corresponds to the hearing threshold of the human ear) in most jurisdictions, but it is 90 dBA in Quebec and 87 dBA for organizations that follow the Canadian federal noise regulations.
Also, as the sound level increases above the criterion level, Lc, the allowed exposure time must be decreased. The allowed maximum exposure time is calculated by using an exchange rate, which is the amount by which the permitted sound level may increase if the exposure time is halved. The 3 dBA exchange rate is more stringent than the 5 dBA exchange rate. For example, if the Lc is 87 dBA, then the maximum permitted duration for a 102 dBA noise exposure in the 3 dBA exchange rate is 15 minutes, with the 5 dBA exchange rate, it is one hour.
To give you an idea of what noise at these different decibel levels sound like, heavy city traffic would be approximately 85 dB, a noisy restaurant would be approximately 90 dB, a motorcycle would be approximately 100 dB, and a handheld drill would be approximately 105 dB.
Employers should create and implement a hearing conservation program for workers who are exposed to noise at the workplace. This program would typically include noise monitoring, engineering controls, administrative controls, audiometric testing, training, and the provision of appropriate HPDs.
Thank you to Delco Water for their help with this forum!
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
Some tasks should be completed at certain times and some tasks need to be completed periodically.
This month, we are telling you about these tasks and when they should be done or how often they should be done.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: During periods of what type of flow should maintenance inspections of tanks and channels be scheduled? Why should they be scheduled at that time?
A: There is no perfect time for inspections, but both high demand and low demand periods of time offer different advantages.
During periods of time when there is higher demand there is a lower water level and the water tanks and channels can be more thoroughly inspected as the sides and the bottoms of the vessels will be more easily accessible and visible.
During periods of time when there is a lower demand there is a higher water level and an inspection that is conducted at this time can reveal whether the additional pressure is putting stress on the vessel and this can make water leaks more noticeable.
Additionally, tanks and channels should be inspected after any major repairs or modifications to ensure the system is still in good working order.
Whenever an inspection is conducted, any corrosion, cracks, leaks, or other signs of deterioration should be noted and addressed promptly.
Q: Generally, how often does a valve exercising program recommend valves be exercised? Why?
A: Valves should be exercised at least once every two years, or annually if possible. The frequency will depend on the location of the valve or the operating conditions. It is a good idea to perform the valve exercising during favourable weather conditions.
Valves are exercised to prevent a build-up of tuberculation or other deposits that could render the valve inoperable or prevent a tight shut-off.
The following are important to remember when turning the valve:
Do not force the valve.
Do not be in a big rush.
Use the lowest torque (turning force or rotational force) setting possible.
Avoid using a cheater bar (a handle extension that allows for greater torque). (A cheater bar shouuld only be used in emergencies.)
Do not close the valve on the first cycle.
If, and when, the valve is moving freely, turn it slowly to avoid a water hammer. If you open or close a valve too quickly the line could rupture.
Listen carefully, sometimes you can hear the flow change when operating a valve and this will help you to determine whether the valve is moving.
Notify the public before starting the process, since debris can be stirred up during valve exercising - this will reduce the number of complaint phone calls.
Consider conducting your flushing program at the same time you exercise the valves.
Always count your turns down and up, they should match.
Q:How often is a maintenance and inspection program for storage tanks and reservoirs performed? Why?
A: Treated water storage tanks and reservoirs should be inspected at least annually to ensure the tanks and reservoirs are free of bacteria and other contaminants. During this time, the tanks and reservoirs should also be inspected for cracks, corrosion, leaks, or other damage. Additionally, tanks and reservoirs should be inspected after any major repairs or modifications.
Thank you to Delco Water for their help with this forum!
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
As water systems operators, there are many tasks that you must do. However, there are some things that you must never do.
This month, we are telling you what not to do and why it should not be done.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: In what situations should a washer never be reused?
A: A washer should never be reused if it was under any of the following three conditions:
Heat Exposure - If a washer is exposed to high temperatures, its material can deteriorate, which can cause it to crack, become brittle, or dry out.
Fluid Saturation - Some materials, with prolonged exposure to fluids, can swell, saturate, and possibly rust (depending on the material).
Physical Deformation - When a washer is under pressure for extended periods, is exposed to high temperatures, or has become saturated with fluids, it can become deformed or damaged.
Q: How close to each other can the sewer and watermain be put? Why should they not be put very close together?
A: The answer is dependent on the municipal/provincial/national code. For example, in British Columbia, the basic rule is that the Water Supplier shall ensure that no sanitary sewer or storm sewer is constructed within 3.0 metres (10 feet), measured horizontally, or 450 mm (18 inches), measured vertically, of the watermain without the approval of the health region. In Saskatchewan, it is recommended that the watermain and sewer main not be within 2.5 metres of each other. In fact, in Saskatchewan, the watermain and the sewer line cannot be in the same trench unless one of the following three conditions apply:
The watermain and sewer main are separated by a minimum of 2.5 metres horizontally under normal soil conditions and the sewer pipe is not internally pressurized.
If a 2.5 m distance cannot be met due to soil conditions, dewatering problems, congestion, etc., the crown (the highest point of the internal surface of the cross-section of a pipe) of the sewer pipe must be at least 0.5 metres below the watermain.
If the horizontal and vertical separation cannot be achieved, the sewer pipe and the joint materials of which it is constructed must be equivalent to the watermain standards.
The watermain and the sewer lines are separated to reduce the potential contamination of the potable water in the watermain from the sewer line in the case of equipment failure (pipe burst, leaks, blow-offs, etc.).
Q:Why should pipes of dissimilar metals not be connected?
A: Bimetallic connections with dissimilar metals should be avoided if at all possible. When one dissimilar metal causes another to corrode, it is called galvanic corrosion (galvanic corrosion happens when there are two dissimilar metals and an electrolyte - some common electrolytes are water, salts, and bacteria). When two dissimilar metals are touching, the electrolyte will jump-start the corrosion process. As electrons move from the anode (the basic metal) to the cathode (the noble metal), the first metal is vulnerable to oxidation. For example, in the case of carbon steel, iron oxide (rust) will form and corrode the weaker metal.
However, there are ways dissimilar metals can be used together without setting off corrosion:
Galvanizing is when a zinc finish is added to the pipe support (zinc is more basic than most metals), so it will sacrific its electrons and spare the electrons of the metal below it.
Minimizing exposure to electrolytes can slow down corrosion and can be accomplished by adding waterproofing, creating drainage systems, or applying sealants to keep electrolytes from seeping into crevices.
Insulating is when two metals are physically separated by adding a barrier between them. A good example of this is when pipe shoes (supports that lift pipes off beams or supports and keep dissimilar metals from rubbing against each other) are used.
Thank you to Delco Water for their help with this forum!
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
Chlorine kills dangerous bacteria, viruses, and parasites in water. It also helps reduce disagreeable tastes and odours in water. However, its by-products can cause major health issues.
This month, we are answering questions about chlorine and its by-products.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q:How are chloramines formed?
A: Chloramines are formed through the combination of chlorine and ammonia. Based on reaction conditions, three different types of chloramines can be created: monochloramine, dichloramine, and trichloramine.
Q: What are some examples of compounds that are produced by the chlorination of organic compounds?
A: The most common examples of disinfection by-products include trihalomethanes (THMs) and haloacetic acids (HAAs). They are both created when chlorine reacts with the natural organic matter in water and they become a concern when this reaction takes place prior to distribution.
Q:What are the effects of some of the compounds that are produced by the chlorination of organic compounds?
A: At high levels and with prolonged exposure, THMs and HAAs are toxins and are carcinogenic (cancer-causing).
Q:What increases chlorine demand?
A: Chlorine demand may increase with elevated levels of iron, manganese, viruses, and bacteria. An increased dosage of chlorine might be required before filtration to make sure that iron and manganese are fully oxidized. If iron and manganese are not fully oxidized, filtration will be unsuccessful. Similarly, if high levels of viruses and bacteria are present, high levels of chlorine might be required for successful disinfection. However, it is important to note that increased chlorine demand will result in higher operation and maintenance costs, as well as possible formation of THMs and HAAs. Thus, caution must be taken when determining the level of dosing.
Q:How is the effective disinfection of a distribution system most accurately monitored?
A: Effective disinfection is monitored by using treatment methods that achieve log removal credits for Cryptosporidium, Giardia, and viruses. Ultrafiltration, ultraviolet light, and chlorination can all provide log removal, with ultrafiltration being the most effective. To meet drinking water guidelines, water treatment plants must have enough of these treatment options in place to remove 99.9% (3-log) of Cryptosporidium and Giardia and to remove 99.99% (4-log) of viruses.
Thank you to Delco Water for their help with this forum!
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
As you most likely know, there are two main types of water - surface water and ground water. Ground water is accessed via a well. Wells must be properly maintained in order to provide safe drinking water.
We often receive questions from individuals about testing their well water for Helicobacter pylori (H. pylori). Unfortunately, it is quite difficult to test water for H. pylori and, therefore, the testing is only done at some universities. Most people discover that their well water might have H. pylori by having breath tests conducted at a doctor's office after they feel ill.
It was once thought that stress caused ulcers. However, in 2005, Barry Marshall and Robin Warren were awarded the Nobel Prize in Physiology or Medicine for their discovery that peptic ulcer disease (PUD) was mainly caused by H. pylori. As a result, PUD that is associated with H. pylori is currently treated with antibiotics. For decades prior to their discovery, it was widely believed that PUD was caused by excess acid in the stomach.
This month, we are answering questions about well water!
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q:Where must a well screen be installed?
A: A well screen is to be installed at any point where the well wall is "loose" or "unstable", often being the furthest point on the bottom of the well. The installation of the well screen will prevent any loose material from entering the well, while still allowing water passage.
Q: Why would a well be acidized?
A: Wells should be acidized when there is a disruption in normal functioning. Acidization will increase the productivity and the lifespan of the well.
Q:How is a well acidized?
A: A variety of chemicals can be used for acidization. Chemicals, that are chosen based on the properties of the well, are pumped into the pores of the well, causing breakdown of buildup. Additionally, new pores can be created by acidizing at a high pressure. The high pressure will cause fracturing of the well's wall, thereby increasing the number of pores that are present for water passage. Once buildup is removed from existing pores or new pores have been created, water will be able to move more efficiently.
Q:What can be done if my well water contains H. pylori bacteria?
A: Different types of water treatment can be used to remove H. pylori prior to consumption. However, if only well treatment is being considered, chlorination can be used to disinfect the well. However, it must be noted that chlorination will not provide a long-term solution to bacteriological contamination as there is likely a break in the well through which new organisms are entering. Also, disinfection will not treat remaining water quality problems and, therefore, further treatment might still be necessary.
Once raw water has been removed from the well, ultrafiltration and ultraviolet light can also be used to remove viruses and bacteria.
Thank you to Delco Water for their help with this forum!
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
Have you found your life's purpose? You are certainly doing important work! Being a diligent, skilled water systems operator prevents the members of your community from becoming ill.
The world definitely needs it, hopefully you are great at it, hopefully you love it, and unfortunately you are probably not paid enough for it (but you are technically paid for it!), so maybe you have found your purpose!
This month, we are answering questions about the purpose of different chemicals and testing procedures in water treatment.
I found my purpose as a circuit rider trainer! I love helping water systems operators to troubleshoot issues and to learn more about water and wastewater treatment. If you would like to learn more, feel free to email me any questions you have!
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q:For what purpose is potassium permanganate most often used?
A: It is most often used for oxidation. It oxidizes dissolved iron, manganese, and hydrogen sulfide into solid particles that are then filtered out of the water.
Q:Other than disinfection, for what can chlorine be used in water treatment?
A: Chlorine can also be used for oxidation. It oxidizes dissolved contaminants before filtration so they can be removed more efficiently. Specifically, chlorine can oxidize iron, manganese, and hydrogen sulfide. It is most often used as an oxidant in greensand filtration.
Q:What is the purpose of adding ammonia to potable water?
A: The main purpose is to enhance the disinfection properties of chlorine and provide longer-lasting disinfection. When both ammonia and chlorine are added to potable water, they react and form chloramines, with the most desired result being monochloramine. Remember, it is always important to ensure an appropriate amount of chemical is being used when treating the water to reduce the chance of overdosing. Ammonia in drinking water can sometimes create an unpleasant taste and smell that is caused by the formation of chloramines.
Q:For what are polyphosphates used in water treatment?
A: Phosphates (orthophosphate and polyphosphate) are typically used to treat inorganic contaminants in ground water as they work well together. Polyphosphates are sequestering agents and their main purpose is to reduce the likelihood of residual iron oxidizing and turning "red" in potable water and of residual manganese oxidizing and turning "black" in potable water. Orthophosphate prevents corrosion and diminishes the amount of lead that is leached from lead pipes. Note, however, that polyphosphates should not be used as a treatment solution to remove iron and manganese, as it only sequesters iron and manganese and does not remove them. Iron and manganese should be properly removed by filtering the water before it is distributed.
Q:What does hydrostatic pressure testing diagnose?
A: This testing is used to ensure structural integrity of equipment and to determine whether the equipment is capable of withholding the pressure that will pass through the system. Hydrostatic pressure testing will indicate any deficiencies in material selection and in connection types that would result in equipment failure or safety risk.
Thank you to Delco Water for their help with this forum!
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
A crucial component of the water treatment process, filtration, has been used for approximately 4000 years. Obviously, the filtration processes of 4000 years ago were much more rudimentary than those we use these days!
Approximately 4000 years ago, people would attempt to avoid illnesses and diseases by boiling water before drinking it and allowing the water to sit. The sediment would sink to the bottom, and people would skim the drinking water from the top of the container.
In the 5th century BC, Hippocrates was the first to develop the concept of passing water through a cloth to help remove silt and other sediment.
Then, in the mid-1700s, Joseph Amy obtained the first patent for a water filter. His design incorporated wool, sponge, and charcoal layers to help purify drinking water. The first water filters for use in the home were sold in 1750.
In 1827, John Doulton and his son Henry (of English fine china and pottery fame) invented the ceramic water filter to remove bacteria from drinking water.
These days, we talk about ultrafiltration, nanofiltration, reverse osmosis, and automatic variable filtration technology, among many others.
This month, we are answering some questions about filters!
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: What is the best indicator that the filter should be backwashed?
A: The best indicators of a filter requiring a backwash include:
- Turbidity: If the filter is beginning to have high turbidity level (Nephelometric Turbidity unit) (NTU) readings on the effluent, this is an indicator that not enough of the contaminants are being removed.
- Head Loss: The pressure is decreasing and sometimes even becomes negative pressure. In a negative head situation, the pressure from gravity is insufficient to provide sufficient flow at the outlet, and the flow speed at the outlet is usually less than 1 litre per minute.
Q:What is the most crucial element of effective filter performance?
A: To ensure the filter is effective, it is critical to design the system with an adequate flux rate (flux rate = measure of flow per unit area). Ensuring that the filter is designed with an appropriate flux will guarantee that the fluid has enough contact time with the media to properly filter out contaminants.
Q:What cannot be controlled in the normal operation of a sand filter?
A: The limiting factor in the operation of sand filters is raw water quality. If, at any time, the quality of the raw water changes, it will alter the success of the sand filter. Operators can change backwashing frequencies and durations, as well as pressures and flows. However, changing the quality of the water entering the sand filter is very difficult without the implementation of another treatment process. Yet another reason source water protection is so important!
Q:How can Giardia Lamblia be removed from a surface water source?
A: Giardia can be removed by coagulation/flocculation/sedimentation (all together as a package) or primarily by filtration (either media (sand) or membrane filtration). The level of degree to which these two processes can remove Giardia is stipulated in drinking water guidelines as 'log removal credits'. It is assumed that sand filtration will remove 2.5 log (99.68%) of all Giardia particles. Any bacteria and viruses that remain after filtration can be inactivated through disinfection. Disinfection can occur in two primary ways, with chemicals or with ultraviolet radiation. Regulations allow (given adequate design conditions) 3 log removal credit (99.9% reduction) to 4 log removal credit (99.99% reduction) to be achieved through inactivation (depending on type and design conditions).
Q:What does it mean if debris is noticed in the filter bed during backwashing?
A: Debris should not be present in the filter bed during backwash, except in the case of mudballs being misinterpreted as debris. A mudball (chunk of caked up filter material) is a result of inadequate backwashing of a filter, of water not being spread evenly over the whole surface, or of channeling. These mudballs result in the filter not being restored to its clean, sand-like state. This is a difficult problem to overcome, especially if an air scour system is not being used. Mudballs are most often caused by the bottom of the filter becoming plugged or clogged. In many cases, if there is no air scour system, mudballs can lead to having to re-bed the filter.
Q:For what is a chemical feed line that is installed after the sedimentation tank and before the filter used?
A: To automatically inject chemicals that will oxidize the dissolved contaminants before the water is filtered.
Thank you to Delco Water for their help with this forum!
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
There is a lot of terminology in the field of water treatment. Sometimes, it is hard to remember it all! This month's forum is a reminder of some of the terminology.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q:What is the purpose of a forced-draft ventilator?
A: Its purpose is to get rid of entrained gases (tiny microbubbles of gas that travel at the same speed as the water and are transported by the flow of the liquid) in water, like CO2 or H2S. It is a treatment process wherein you cascade water down through a loosely packed column while simultaneously blowing atmospheric air upward through the down-flowing water.
Q:What is quicklime? What happens when quicklime is added to water?
A: Quicklime is a caustic alkaline substance also known as calcium oxide, and it is produced through the heating of limestone. When quicklime is added to water, an exothermic reaction takes place to produce slaked lime (which is more common referred to as calcium hydroxide). Simply put, calcium oxide becomes hydrated in water and becomes calcium hydroxide.
Q:What is a centrifugal pump?
A: A centrifugal pump is a pump that has a shaft-driven impeller that rotates inside a casing and the impeller is always submerged in water. When the pump is operating, the impeller spins rapidly. The centrifugal force applied to the water from this rotation forces the water outside of the casing, where it exits through a discharge port. More liquid is introduced through a suction port and the velocity imparted to the liquid by the impeller is converted to pressure energy.
Q:To what does suction lift refer?
A: Suction lift refers to the negative pressure present on the suction side of a pump due to the pump being located above the source of liquid. Most centrifugal pumps can operate with a suction lift as long as the pump is primed (primed means that the suction line, pump casing and impeller are full of liquid and all of the air or non-condensable gases are removed).
Q:What is a bubbler and how does it work?
A: Bubblers disperse tiny bubbles of gas into water. The tiny bubbles travel to the liquid's surface more slowly than larger bubbles that are created through standard aeration. This results in an overall increase in oxygen contact time with the liquid. Bubblers are most often used in wastewater applications as the increased oxygen contact time with the liquid gives bacteria more time to use dissolved oxygen to convert organic components into carbon.
Thank you to Delco Water for their help with this forum!
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
This month, we present an investigation and ask you to derive your own conclusions.
The consequences of climate change on water are said to be two-fold - water availability and water quality. Increased wind energy can reduce the reliance on hydro power, which can divert more surface water from hydro power to irrigation, which can in turn reduce overall groundwater extraction. However, there are concerns that wind turbines might negatively impact groundwater quality. This month, we will present some information and ask you to form your own opinion.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q:Do wind power projects cause the deterioration of groundwater quality?
However, some people believe that wind turbines are causing water wells to be poisoned: Rick Nicholls, a Member of the Provincial Parliament of Ontario from 2011 to 2022, states that "Installing wind turbines means pile-driving massive steel beams into the bedrock. The problem is that the bedrock is made of Kettle Point black shale and is known to contain uranium and arsenic. Vibration from the pile-driving breaks up this toxic shale below the groundwater and contaminates it. Area residents can't drink, bathe, or wash their clothes because of this. Water wells are being poisoned as the government continues to allow the pile driving." (https://torontosun.com/2017/09/11/concern-that-wind-turbines-are-polluting-ground-water)
Q:What are some examples of wind power projects that have potentially caused the deterioration of groundwater quality?
Dave Lusk holds a jar of water drawn from his Wallaceburg well. Wind turbines surround his property.
Q:In what way does the groundwater quality potentially deteriorate? What health effects could this have?
A: In North Kent wells, numerous exceedences for multiple aesthetic parameters were found. It was also found that a comparison of results with those in a baseline study strongly suggests significant deterioration in general well water quality, which is consistent with well water interference having occurred within the area in the previous years. The Expert Panel stated that it could have been due to construction and/or to operation of the North Kent wind turbines. However, the Expert Panel could not conclude that health risks were present, but said several contaminants of concern were identified, including lead, arsenic, and total coliforms. More sampling and testing of well water is needed to determine whether the water poses health risks. (https://www.chathamdailynews.ca/news/potential-for-water-well-interference-caused-by-north-kent-wind-farm-low-participation-prompts-call-for-more-sampling)
Test results obtained by Dr. Rachel Connor over a four-year period showed high levels of the potentially cancer-causing chemical trihalomethane (THM). Research has also linked THMs to stillbirths and miscarriages. At one point, samples taken near her home showed THM levels that were almost 70% above the recommended UK maximum. Dr. Connor says that all the medical advice states that the effects of THMs may not be seen for 10 to 20 years. However, regulators say that the data Dr. Connor found related to periods when specific problems were being investigated, and they say that the water supply is safe. However, test results from East Ayrshire Council stated that the water had been grossly contaminated by E. coli bacteria. Additionally, tests showed iron levels 27 times over the regulatory limit and turbidity at 10 times the maximum acceptable level. Manganese levels also increased after the wind farm was built from just under the allowed level to 14 times the maximum concentration that is allowed. However, ScottishPower Renewables, who operate the Whitelee site, insist that the wind farm has had "no negative impact" on water supplies. (https://www.dailyrecord.co.uk/news/scottish-news/doctor-claims-scotlands-biggest-windfarm-4881760 and https://www.dailyrecord.co.uk/news/scottish-news/ex-manager-wet-wet-wet-seeking-4597180)
What are your thoughts? There are over 341 000 wind turbines on the planet, 124 of which are in Canada's largest wind farm in Chatham-Kent and 215 of which are in Whitelee Wind Farm, the largest on-shore wind farm in the United Kingdom.
Do wind farms not impact water, as the Union of Concerned Scientists states?
Are water wells being poisoned and levels of potentially carcinogenic THMs increasing, as Rich Nicholls and Dr. Connor state?
Do wind farms only cause groundwater quality issues when they are at a massive scale? Are smaller wind farms causing groundwater quality issues to a lesser extent or in a gradual manner that will cause problems in the future? Why are we not hearing about this more often, since there are over 341 000 wind turbines on the planet?
Do wind farms have "no negative impact" on water supplies, as ScottishPower Renewables claim?
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
We hope you are having a great summer! This edition is all about water hammers - what they are, what causes them, what they cause, and how to minimize them.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: What are water hammers?
A: Water hammers exist when you hear a sound like someone hammering on a pipe. Water that is under pressure and in motion can exert tremendous force inside a pipe. When a rapidly closing valve suddenly stops water from flowing in a pipe, pressure energy is transferred to the valve and to the pipe wall.
Q: What causes water hammers?
A: They are commonly caused by opening or closing a valve too rapidly, and by large pumps starting and stopping. In either case, there is a momentary increase in pressure due to a sudden change in direction of the water or in the velocity of the water.
Q: What do water hammers cause?
A: They can damage valves and burst pipes in extreme cases, because the magnitude of the forces that result from the water hammers can be extremely large and neither the water nor the pipe will compress to absorb the shock.
Q: What can minimize water hammers?
A: Some methods to reduce or eliminate water hammers and their effects include:
Opening and closing valves slowly.
Reducing the pressure of the water supply.
Using appropriately-sized pipes to reduce flow velocity.
Having, and using, pressure relief valves (PRVs) that release some of the energy that is created by a sudden stop in flow.
Having, and using, slow-closing check valves to moderate pressure changes during pump starts and stops.
Thank you to Delco Water for their help with this forum!
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
Low lift pumps, submersible pumps, horizontal centrifugal pumps, cavitation, bellhousing, shock waves... there are so many different types of pumps and so much information to learn about them! We hope this newsletter helps pump up your knowledge about pumps!
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: What should an operator do to increase capacity and eliminate the need for a new pump if a low lift pump is not adequate to keep up with flow at certain times of the day?
A: To increase capacity without pump alterations, the operator could lower the pressure that the low lift pump is required to pump against. This could be accomplished by lowering the operating height of the treatment process (likely through the means of a large tank - a clarifier or a gravity filter). Any existing low lift pump likely has a flat pump curve. Therefore, even a small reduction in the required pressure from the pump will result in a significant flow increase.
If the low lift pump is located above ground, a storage tank on the pump inlet would allow for operation at maximum capacity. Fluctuating peaks in flow would be captured in the storage tank and emptied via gravity at a max flow rate over time. Therefore, increasing the overall flow through the pump.
Q: What type of pump would be used for a higher capacity well?
A: For any large well, the use of a submersible pump is the most advantageous. The overall capacity of the given pump will then depend on the size of the motor, the impeller, and the type of pump material.
Q: What is the most important effect of the extra lubricant if the pump bearings on horizontal centrifugal pumps are over-lubricated?
A: Lubrication allows for the separation of moving parts (i.e., bearings), hence minimizing friction that will cause degradation. In addition, it can also aid in controlling contamination, facilitate the absorption and transformation of heat, and reduce energy consumption of the system. If the moving parts of the pump are over-lubricated this can result in leaking grease, energy loss, and overheating. Over time, the high temperatures will result in oil degradation and buildup on the bearings, which will cause system failure.
Q: What must be true of all couplings on pumps to meet safety regulations?
A: Occupational Health & Safety laws require guards to be installed on all equipment that has pinch points, energized parts, or other hazards that could endanger workers. For this reason, all couplings on pumps are required to be guarded or protected. This means that the coupling must be fully encapsulated to ensure that there is no hazard due to bolts, nuts, setscrews, or revolving surfaces. This guard apparatus is commonly referred to in industry as a bellhousing.
Q: What would a sound like a rotating bowl full of rocks in a pump indicate?
A: If the inside of your pump sounds like popping bubbles or a rotating bowl full of rocks, it is likely due to cavitation. Other noises that might also be heard due to cavitation are a cracking or a continuous rumble. These noises are different than a periodic rattle sound, which may be caused by mineral deposits or eroded material. A pump operating optimally will have a consistent hum.
Cavitation is caused when there is not enough pressure on the inlet side of the pump. This results in the formation of tiny air bubbles in the process fluid, which then flow to the outlet side of a pump. At the outlet, the pressure increases greatly, which causes the bubbles in the fluid to implode. These implosions create shock waves that hit the impeller and cause pump vibration, mechanical damage, and potentially even pump failure.
Q: What might partial blockage on the intake line of a centrifugal pump cause?
A: For optimal pump operation, the conditions at the inlet of the pump are crucial. There must be a consistent flow of fluid entering the pump at a sufficiently high pressure. Partial blockage on the intake line of a centrifugal pump would interrupt these conditions and cause low flow to the pump, resulting in cavitation and an increase in noise and vibration.
Thank you to Delco Water for their help with this forum!
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
The Guideline for Canadian Drinking Water Quality for pH is 7.0-10.5. Keeping water at an appropriate pH level is very important, because if the water is too acidic it can leach metals from pipes. This month, we answer some common questions about pH - including how it can be increased or decreased, how to calibrate pH meters, and much more!
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: What is an effective chemical to use to raise pH?
A: In potable water treatment, the pH needs to be increased when the solution is acidic. This means the pH is below a neutral pH of 7. To increase the pH of water that is acidic, the most effective chemical to use is sodium hydroxide (NaOH), also known as caustic soda. This is done most efficiently and safely via an injection system fed directly into the process line.
Q: What chemicals can be used to reduce the water's pH?
A: A variety of aqueous acids can be used to reduce the pH of water. This includes sulphuric acid, hydrochloric acid, nitric acid, and citric acid. Diluted sulphuric or hydrochloric acid are most recommended as they are the most cost effective and can reduce the pH most efficiently.
Q: Against what should pH meters be standardized?
A: The most common and accurate technique to determine pH is to measure the potential difference across an electrode bulb/water interface using a voltmeter. To calibrate this type of pH meter, pH buffers are used. These buffers have a known pH at different temperatures and cover the entire pH scale. These buffers are utilized internationally and are traceable, so that values can be compared globally. Some of the most common calibration buffers used are the IUPAC buffers pH 4.005 and pH 10.012 (at 25°C). If the pH of the water being measured is within an extremely high range (pH > 11) it is recommended to calibrate the meter with high range buffers (pH 10.012 and pH 12.45). If the pH of the water being measured is within an extreme low range (pH < 2) it is recommended to calibrate the meter with low range buffers (pH 1.09 and pH 4.01).
Q: What increases when lime is fed to water for corrosion control?
A: Lime is a mineral composed of mostly oxides and hydroxides, which primarily occurs as calcium oxide (CaO) and calcium hydroxide (Ca(OH)₂). When fed into water, lime causes an increase in pH, calcium content, and alkalinity formed from the added hydroxide and dissolved CO₂ in the water. This aids in corrosion control because the increased constituents result in the water being closer to the precipitation of calcium carbonate (CaCO₃), which provides a protective coating on the inside of water mains.
Q: What do calcium carbonate, calcium oxide and magnesium bicarbonate increase?
A: Calcium and magnesium minerals increase the hardness of water. The main sources of these constituents are from calcium carbonate, calcium oxide, and magnesium bicarbonate in the ground. As water moves through soil and rock, it dissolves small amounts of the minerals with which it interacts. Therefore, ground water contains higher levels of minerals than surface water, since the latter does not pass through the ground. Hardness is the amount of dissolved minerals in water.
Thank you to Delco Water for their help with this forum!
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
Coagulation, flocculation and sedimentation are three steps in the water treatment process that must all work for the process to be successful. If coagulation is incomplete, the flocculation step will be unsuccessful, and if flocculation is incomplete, sedimentation will be unsuccessful. In this issue of the forum, we answer questions about coagulation, flocculation and sedimentation.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: Alum is used as a chemical coagulant. When alum is added to water, a floc is formed from the combination of alum and what?
A: Floc is formed from the combination of two aluminum ions and six hydroxyl ions along with trapped fine particles, colloids and other contributions to turbidity that can then be settled.
Q: What is the most widely used coagulant?
A: Aluminum sulphate is, by far, the most commonly used coagulant. It is relatively inexpensive, and it is easy to handle, store, and apply.
Q: What affects coagulation performance?
A: Coagulation performance is dependent on the pH of water. It has been found that, with most waters, the best pH for coagulation and flocculation is between 5 and 7.
Q: When coagulant aids are used with aluminum sulfate, what is the ratio of coagulant aid to aluminum sulfate?
A: Coagulant aids used with aluminum sulfate tend to be polymers. These polymers vary widely in type, classification, strength, method of storage, and application rate. Therefore, it is not possible to typify that down to a single ratio of coagulant aid (polymer) to alum. In most circumstances, in general conditions, the polymer dosage will be less than the alum dose.
Q: What does optimum flocculation require?
A: An efficient flocculation process requires the right combination of coagulant dosage, detention (mixing) time, mixing intensity, and flocculation tank design.
Q: What is the result if sludge is not continually removed from the sedimentation basin?
A: If sludge is not removed from the sedimentation basin often enough, the effective (useable) volume of the tank will decrease, reducing the efficiency of sedimentation.
Q: What is the recommended detention time for a sedimentation basin?
A: Most sedimentation basins have detention times of one to three hours.
Thank you to Delco Water for their help with this forum!
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
Happy World Water Day! It is time for the final installment of our three-part series on water sampling! This information is about actions that should be taken based on the results of the tests performed on water samples.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: When is an emergency boil water advisory called based on results from testing a water sample and when is a precautionary boil water advisory called based on results from testing a water sample?
A: Emergency boil water advisories are issued in response to the confirmed detection of Escherichia coli (E. coli) in drinking water. The detection of E. coli in drinking water is a definite indication of human or animal faecal contamination and the possible presence of pathogenic microorganisms. If the presence of E. coli is confirmed in drinking water, an emergency boil water advisory should be issued immediately. Emergency boil water advisories are very important in situations where epidemiological evidence indicates that the drinking water is or may be responsible for an outbreak of illness.
Persistent presence of total coliforms in the distribution system, despite remedial measures (such as flushing water mains, increasing chlorine residuals) and unexpected and significant changes in routine monitoring parameters within the distribution system such as pressure, turbidity and disinfectant residuals may prompt the issuance of a precautionary boil water advisory.
Boil water advisories are not an effective measure for addressing chemical or radiological contamination events, as boiling the water does not remove or reduce the concentration of these types of contaminants in the water. “Do not consume” and “do not use” advisories are usually issued when a chemical contaminant is suspected or confirmed in a drinking water supply.
Q: When operating a surface water plant, which laboratory tests are most significant for establishing dosages for coagulation?
A: Jar tests are the most significant tests for establishing dosages for coagulation. This is because jar tests are laboratory procedures that simulate coagulation/flocculation with differing chemical doses. The purpose of jar tests is to estimate the minimum coagulant dose that is required to achieve certain water quality goals. Samples of water to be treated are placed in six jars, various amounts of chemical are added to each jar, stirred, and the settling of solids is observed. The lowest dose of chemicals that provides satisfactory settling is the dose used to treat the water.
Q: What are volatile organic compounds, and what do I need to do if I find them when I test the water sample?
A: Volatile organic compounds (VOCs) are chemicals that both vaporize into air and dissolve in water. They are pervasive in daily life, because they are used in industry, agriculture, transportation, and day-to-day activities around the home. Once released into groundwater, many VOCs are persistent and can migrate to drinking water supply wells. When water is treated with chlorine to kill waterborne pathogens, the chlorine reacts with naturally occurring organic matter in your pipes and various (potentially carcinogenic) VOCs form as disinfection by-products. Many VOCs can be removed with activated carbon filters. Reverse osmosis systems that meet the standards can remove many VOCs as well. If VOCs are detected, sampling must then be conducted quarterly.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
The long month of January has passed and here is the second email of a three-part series on water sampling! This information is all about taking and preserving water samples.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q:How should samples taken for routine analysis be preserved?
A: The time between sampling and analysis should be kept to a minimum. The water sample should be stored in glass or polyethylene bottles at a low temperature (around 4°C). It is recommended that the sample be stored in the dark.
Q: What might cause temporary cloudiness in a freshly drawn sample of tap water?
A: Cloudy water, also known as white water, is caused by air bubbles in the water. It is completely harmless. It usually happens when it is very cold outside because the solubility of air in water increases as water pressure increases and/or water temperature decreases. Cold water holds more air than warm water.
Q: According to regulations, where should bacteriological samples be collected?
A: Bacteriological samples should not be collected from any tap which may have additional water treatment devices on it (for example, a home water softener). Water samples should only be collected from a cold water tap. A tap without a screen should be used to take the sample, or the screen should be removed before the sample is collected. The water sample should be taken from a clean sink and faucet. The person taking the sample needs to wash their hands with soap and warm water before taking the sample. The cold water should be run constantly for at least two minutes before the sample is collected. The person taking the sample should hold the bottle near the base of the tap to get the sample, and then they should put the cap on the bottle right after collecting the sample. They should make sure the cap is secure but they should not over-tighten it.
Q: What is the minimum length of time water must remain motionless in pipes prior to first-draw residential lead sampling?
A: The minimum length of time water must remain motionless in pipes prior to first-draw residential lead sampling is eight hours. However, the water should not have been stagnant in the pipes for more than 24 hours. To ensure that representative samples are collected, the aerator or screen on the outlet should not be removed prior to sampling.
The Lead and Copper Rule specifies that all public water systems must initially monitor for lead content by collecting samples from high-risk residences.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
2022 has begun and we are beginning a three-part series on water sampling! Sometimes, chain of custody of water samples must be demonstrated for legal purposes. Sometimes, water samples are not admissible as evidence before the court. Therefore, it is important to have responsible people in charge at all times and to document everything.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q:Who can collect samples?
A: The field sampler, wastewater laboratory technician, or a bylaw officer can collect samples.
Q: How is chain of custody demonstrated when it is necessary for legal purposes?
A: Chain of custody is demonstrated when there is documented evidence confirming that a sample has not been exchanged with another sample, contaminated, or tampered with in any manner. The chain of custody shows how evidence was collected, who collected it, the location where it was collected, and who has had custody of the evidence throughout the various steps that followed. The forms confirming the sample has been secure should be signed by each person that had true possession of the sample.
Q: What does it mean to be in true possession or custody?
A: A sample is considered to be in true possession or custody when it is in the actual physical possession of one person, in view of one person after being in their physical possession, in physical possession and then locked up so that nobody can tamper with it, or kept in a secured area that is restricted to authorized personnel only.
Q: When are samples not admissible as evidence before the court?
A: When their continuity has been interrupted for any reason – when the sample was not in true possession or custody the entire time.
Q: Which forms should the chain of custody documentation include?
A: The chain of custody documentation should include the following forms:
Reagents and Supplies Sheet
Field Data Sampling Sheet
Sample Shipping/Receiving Sheet
Sample Receipt and Record Log Sheet
Sample Control Record Sheet
Analytical Data Sheet
Sample Data Archiving Sheet
Q: What are the three elements that must be taken into consideration to achieve a full control of sample custody?
A: To achieve a full control of sample custody, control at site must be achieved by a member of the sampling team who is responsible for correct labelling and storage of samples. Transport needs to be controlled by completing a form with shipping notes, including brief descriptions of the samples. Also, within laboratories, custody of samples is controlled by establishing detailed procedures, as many samples must be tested and reported correctly.
Q: What steps can be taken to ensure legal sample continuity?
A: Proper techniques for sealing the sample should be used, such as custody seals. Masking tape should be used to seal the sample.
Permanent waterproof uniquely numbered label and/or a diamond-tipped scribe, waterproof marker, or other means of permanent identifications with sufficient information to enable sample identification should be used to label the sample. All data from the label should be transferred into the Field Sampling Data Sheet including the reference to the unique identifier.
The sample must be locked in a secure container, refrigerator, etc. or kept in the possession or view of the person dealing with the sample at all times until it can be secured. The number of people who handle the sample must be limited and only one person can have access to the sample at any given time.
The Chain of Custody Forms must be completed and included with the sample.
The sample must be placed in an appropriate and secure shipping container. During transportation to the laboratory and from the laboratory to the sender/submitter or to the court, the sample must be sent by appropriate means and must arrive within the required holding period. Samples should be delivered to the laboratory as soon as possible to minimize sample degradation.
Laboratory personnel are responsible for maintaining the chain of custody, the sample must be traced from the moment it was received to the time the final results are reported.
To introduce sample results as evidence in court, the chain of custody procedure must be clear and complete. The chain of custody procedure must demonstrate that the sample has not been exchanged, contaminated, or tampered with at any stage. Detailed notes of sample collection methods, container markings, packaging, shipping and details for sample analysis, storage and disposal must be retained and they must be made available as required.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
We are sure that you have heard about lead pipes - from the stories that have come out of Flint, Michigan to Regina, Saskatchewan - lead pipes are in many communities. This month, we are going to share some information about lead pipes, including the maximum acceptable concentration for total lead in drinking water, the health effects of lead in drinking water, what you can do if there is lead in your water, and what water treatment plant operators can do to help.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q:What is the maximum acceptable concentration for total lead in drinking water?
A:The maximum acceptable concentration for total lead in drinking water is 0.005 mg/L (5 µ/L), based on a sample of water taken at the tap and using the appropriate protocol for the type of building being sampled. Every effort should be made to maintain levels in drinking water as low as reasonably achievable (or ALARA).
Q:What are the health effects of lead in drinking water?
A: Inorganic lead compounds have been classified as probably carcinogenic to humans, based on findings in experimental animals. However, the cancer effects are not the biggest concern when it comes to health effects of lead in humans. Effects that have been studied include reduced cognition, increased blood pressure, and renal dysfunction in adults. In children, adverse neurodevelopmental and behavioural effects in children have been found. The strongest association observed to date is between increased blood lead levels in children and reductions in intelligence quotient (IQ) scores. The threshold below which lead is no longer associated with adverse neurodevelopmental effects cannot be identified.
Q:What can I do if there is lead in my water?
A: Some certified residential treatment devices are available that can remove lead from drinking water. However, their use should not be considered to be a permanent solution. The best approach to minimize exposure to lead from drinking water is to remove the full service line and to control corrosion in the distribution and treatment systems.
Q:What can water treatment plant operators do to help until the lead pipes have been replaced?
A: The more acidic the water is (pH below 6.5), the greater the ability of the water to leach lead from lead pipes. Therefore, ensuring that the pH level of the water meets the Guideline for Canadian Drinking Water Quality (7.0-10.5) is important. Since alkalinity is a measure of the capacity of the water to resist changes in pH, maintaining an appropriate level of alkalinity in the treated water is also important.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
It is vital that you are prepared in the case of an emergency in a confined space. There needs to be rescue personnel with personal protective and rescue equipment ready and available to help rescue your employees in the event of an emergency involving a worker who is in a confined space.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q:How do you prepare for a confined space rescue scenario?
A: The following are some of the activities that can help you prepare for a confined space rescue scenario:
Run rescue drills - The rescue service personnel, in addition to your employees, must also be trained as authorized entrants and be trained in performing the assigned rescue duties, CPR and first aid that is laid out in your confined space entry emergency evacuation and rescue plan. It is very important to run rescue drills on a regular basis and to adequately inform employees of the hazards that are present in every confined space in which they will be working. By having staff members and rescue personnel practice different confined space rescue scenarios, they will be better prepared to react appropriately when an actual emergency occurs.
Understand what a confined space emergency is - Not all incidents in confined spaces are emergencies. The determining factor to help you decide whether an incident is an emergency is time sensitivity. For example, if an employee becomes trapped in a confined space and there is limited oxygen in the air within the space, then that is considered a very time-sensitive scenario and it is an emergency. However, if an employee becomes trapped in a confined space that has sufficient oxygen levels, that is not an emergency and a slower and more methodical approach can be taken to perform the rescue. Basically, if there are any hazards that would cause a life threatening injury to an employee, then that is an emergency.
Make sure that every entrant wears proper equipment - Authorized confined space entrants must have a chest or full body harness on, attached to a retrieval line at the centre of their backs. If this option does not seem possible or if it would create a greater hazard, then wristlets can be used instead. The retrieval line must be attached to a fixed point or a mechanical device outside of the confined space and it must be able to retrieve a person who is in a deep vertical space.
Discuss rescue capabilities with local authorities - In many confined space rescue scenarios, the local police, fire department and paramedics need to be brought onto the scene to assist with the rescue and first aid treatment of the trapped and/or injured employee. These departments have different resources, capabilities, and response times. Understanding what they are capable of and what they can do to assist you in a confined space rescue scenario is crucial to making a confined space entry emergency evacuation and rescue plan that is as effective as possible.
Have a rescue team ready - This is crucial for ensuring employees can be rescued in a timely manner. This team could consist entirely of your employees who have been trained and certified for confined space rescue, or it could include members of local emergency responders. Alternatively, you could hire an external contractor to provide a rescue team.
Ensure that there is an adequate communications system to enable communication between people inside and outside the confined space and to summon help in an emergency.
Make sure that the attendant is trained to communicate with entrants, to raise the alarm quickly in an emergency, and to take charge of the rescue procedures. Effective arrangement for raising the alarm and carrying out rescue operations in an emergency are crucial. Entrants can also be trained to use radios, air horns, a rope, personal alarms, or other methods to raise the alarm if they need help. Communication systems must be maintained and tested regularly to ensure they are functioning properly.
Have contingency plans - these will depend on the nature of the confined space, the risks identified and the likely nature of an emergency rescue.
The responsible supervisor must ensure that the emergency response plan includes the emergency procedures to be followed if there is an accident or other emergency, including procedures in place to evacuate the confined space immediately when an alarm is activated, if the concentration of oxygen inside the confined space is no longer safe, or if there is a significant change in the amount of hazardous substances inside the confined space.
Q:What are the three main types of rescue?
A: The three main types of rescue are:
Self-rescue - A worker gets themselves out of the confined space, for example by using a self-contained emergency breathing apparatus. This is the best option as it does not put anyone else at risk and it is a quicker form of rescue.
Non-entry rescue - A worker is rescued by a trained team who do not need to enter the confined space (for example, the worker is extricated by a tripod and lifeline).
Entry rescue - A rescuer or team enters the confined space to retrieve the worker (for example, in a complex confined space where it is not simply a vertical entry). This is the last option, as it puts other people at risk and exposes them to the hazards in the confined space.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
Think about the typical hazardous energy-related accident. A well-meaning worker does not see that their coworker is at risk, they activate equipment, and the sudden start-up causes serious injury, sometimes death, for the coworker who was unable to react in time to escape the unexpected danger. Confined spaces greatly expand the risk of this scenario because the coworker is now impossible to observe due to them having entered a confined space and start/stop control of the dangerous equipment being located outside this space. Add to this situation that the person watching the confined space entry operation has their attention on the people who are inside the confined space and not on distant personnel who still have the ability to trigger an accident. The result can be a seriously injured worker in a difficult place to perform a rescue.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q:How are energy sources controlled in confined spaces?
A: Isolating each form of energy that could be present is critical for worker safety in confined spaces. All potentially hazardous energy sources such as electrical, mechanical, hydraulic, pneumatic, chemical, or thermal must be de-energized (or isolated) and locked out before anyone enters the confined space so equipment cannot be turned on accidentally. Verification by testing is a critical step of lockout, it is important to ensure energy is fully dissipated to eliminate potential exposure inside the space before entry. Entrants must be authorized to apply lockout to protect themselves. Personal safety locks should be placed on all required lockout isolation points, and the controls should be tested to verify safe working conditions. If lock out is not possible, the hazardous energy must be controlled in a manner that eliminates or minimizes worker exposure to the hazards before workers can enter the confined space. Any method of control other than isolation and lockout must be evaluated and its effectiveness in controlling the hazardous energy must be demonstrated.
Many times, confined spaces have never been entered as they were either newly created or no prior history of needing to work inside the confined spaces exists. Entry supervisors must have the ability to create an accurate and effective lockout procedure prior to issuing a permit, or they need to have access to trained personnel who can complete a hazardous energy assessment and document the correct lockout procedure for the task to be performed.
Q:What are some other safety precautions that should be taken in confined spaces?
A: Any liquids or free-flowing solids should be removed from the confined space to eliminate the risk of drowning or suffocation. All pipes should be physically disconnected or isolation blanks should be bolted in place, closing the vales is not sufficient! Use two blocking valves, with an open vent or bleed valve between the blocking valves when isolating pipelines or similar conveyances to prevent entry of materials and hazardous contaminants. Put barriers in place to prevent any liquids or free-flowing solids from entering the confined space. Ensure that the opening for entry into and exit from the confined space is large enough to allow the passage of a person using protective equipment.
Q: What work practices help ensure confined space work is done safely?
A: There are several work practices that help ensure confined space work is done safely, including:
Training employees about the potential hazards of confined spaces and your facility's confined space entry requirements.
Remembering to retest the air in confined spaces periodically to verify the air remains safe for personnel. However, "periodically" leaves room for interpretation, and a safer procedure is to arm all confined space workers with direct-reading personal gas monitors and ask them to continuously monitor for gas hazards throughout the work period. If conditions begin to trend toward danger, workers will have the notice they need to exit the confined space safely. If you rely on alarm-only monitors, this would not be possible - alarms are set to go off at predetermined thresholds, and alarm-only instruments do not give workers a heads-up about potential dangers.
Training employees who enter confined spaces (entrants) and those serving as the "hole watchers" (attendants). This should include a review of confined space hazards; confined space preparation requirements, responsibilities of entrants and attendants, and emergency response. You may want to quiz your entrants and attendants to ensure that they know the information!
Thinking of the entry permit form as a checklist to verify that the confined space is safe for entry. Ensure that the entry permits are completed accurately and fully.
What needs to happen when, despite safety measures having been taken, there is an accident in a confined space? Watch for part 4 of our Confined Space series next month to learn about what to do when emergencies occur.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
Worldwide, approximately 56% of confined space fatalities (so, over half!) are caused by inadequate air quality. Insufficient oxygen is the leading cause of death due to atmospheric hazards, followed by hydrogen sulfide. Therefore, it is very important to ensure that confined space air quality is tested properly and the air quality is maintained.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q:How should air quality testing be performed?
A: The air within the confined space should be tested from outside of the confined space before entry into the confined space. The air should be tested throughout the confined space - side-to-side and top to bottom! Continuous monitoring should be considered in situations where a worker is in a space where atmospheric conditions could change (for example, due to broken or leaking pipes or vessels, work activities that could create a hazardous environment, or when isolation of a substance is not possible). The air quality testing should be performed by a trained worker who uses detection equipment that has remote probes and sampling lines. The testing equipment should always be properly calibrated and properly maintained. The sampling should show that the oxygen content is within safe limits, toxic gases are not present, the atmosphere is not flammable, and ventilation equipment is operating properly. The results of the air quality testing need to be recorded on the Entry Permit along with the equipment or method(s) that were used to perform the tests.
Q:How is air quality maintained?
A: Usually, natural ventilation (natural air currents) is not reliable and is not sufficient to maintain air quality. Mechanical ventilation (blowers, fans) is usually needed to maintain air quality. If mechanical ventilation is used, there should be a warning system in place to immediately notify the worker in the event of a hazard or of a failure in the ventilation equipment. Care should be taken to make sure that the air that is being provided by the ventilation system is "clean" throughout the entire confined space. Ease of air movement throughout the confined space should be considered because of the danger of pockets of toxic gases still remaining, even with the use of mechanical ventilation. It is essential to remember that oxygen should not be substituted for fresh air, as increasing the oxygen content will significantly increase the risk of fire and the risk of explosion. The use of mechanical ventilation should be noted on the entry permit. The air that is removed from the confined space must be exhausted away from workers on the outside.
Q: How are fires and explosions prevented in confined spaces?
A: Work in which a flame is used or a source of ignition might be produced should not normally be performed in a confined space unless all flammable gases, liquids, and vapours are removed before beginning any work that involves a flame or the potential production of a source of ignition. Mechanical ventilation should be used to keep the concentration of any explosive or flammable hazardous substances less than 10% of its Lower Explosive Limit and to make sure that the oxygen content in the confined space is not enriched (oxygen content should be approximately 19.5% to 23%, but check the specific regulations in your jurisdiction). Surfaces coated with combustible material should be cleaned or shielded to prevent ignition. If at all possible, fuel or fuel containers should not be brought into a confined space. Welding equipment should be checked to make sure that it is in good condition. Where appropriate, spark-resistant tools should be used and all equipment should be bonded or grounded properly.
While doing any work in which a flame is used or a source of ignition might be produced, the concentrations of oxygen and combustible materials must be monitored to ensure that the oxygen levels remain in the proper range and the levels of the combustible materials are not in excess of 10% of the Lower Explosive Limit. In special cases, this might not be possible and, in those cases, additional precautions must be taken to ensure the safety of the worker prior to entering the confined space.
If potential flammable atmosphere hazards are identified during the initial testing, the air in the confined space should be cleaned or purged, ventilated, and then tested again before entry to the confined space is allowed. Entry should only occur after the air testing results show that the air quality is within allowable limits, as the gases that are used for purging can also be extremely hazardous! Furthermore, if a fire does happen it is important that the measures introduced do not increase risks (for example, carbon dioxide in some fire extinguishers can displace oxygen, which would be dangerous in a confined space).
Watch for part 3 of our Confined Space series next month to learn about controlling energy sources in confined spaces.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
Many workers are injured and killed each year while working in confined spaces. An estimated 60% of the fatalities have been among the would-be rescuers. To effectively control the risks associated with working in a confined space, a confined space hazard assessment and control program should be implemented for your workplace. Before putting together a confined space hazard assessment and control program, make sure to review the specific regulations that apply to your workplace as the regulations can vary slightly between jurisdictions. In case you have questions, here is a link to contact information for the Canadian government departments that are responsible for occupational health & safety.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: What is a confined space?
A:A confined space is a fully or partially enclosed space that is not primarily designed or intended for continuous human occupancy, has limited or restricted entrance or exit (or a configuration that can complicate first aid, rescue, evacuation, or other emergency response activities), and can represent a risk for the health and safety of anyone who enters the space due to one or more factors (its design, construction, location, or atmosphere; the materials/substances in it; work activities being carried out in it; or the mechanical, process, and safety hazards that are present).
Confined spaces can be below or above ground. Despite its name, a confined space is not necessarily small. Examples of confined spaces include utility vaults, tanks, water supply towers, sewers, pipes, boilers, manholes, pump stations, wells, storage bins, subcellars, culverts, and open ditches (when entrances and/or exits are limited).
Q:What hazards can be found in a confined space?
A: All hazards that are found in a regular work space can also be found in a confined space. However, they can be even more hazardous in a confined space than they are in a regular work space. Some examples of hazards in confined spaces are:
Poor air quality (There may be an insufficient amount of oxygen for the worker to breathe or the atmosphere could contain a poisonous substance that could make the worker ill or even cause the worker to lose consciousness.
Asphyxiants, including argon, nitrogen, and carbon monoxide. (Gases that can become so concentrated that they displace oxygen in the air, low oxygen levels can cause symptoms such as rapid breathing, rapid heart rate, clumsiness, emotional upset, fatigue, nausea and vomiting, collapse, convulsions, and coma. Asphyxiants can cause death.)
Chemical exposures due to skin contact or ingestion and inhalation of "bad" air.
Fire (Flammable liquids, gases, and combustible dusts can cause an explosive/flammable atmosphere because if they were ignited there would be a fire or explosion.)
Process-related hazards (residual chemicals, release of contents of a supply line)
Physical hazards (noise - entrants might not be able to hear warnings or directions, heat/cold, radiation, vibration, electrical, inadequate lighting)
Safety hazards (moving parts of equipment, structural hazards, engulfment, entanglement, slips, falls)
Vehicular and pedestrian traffic
Shifting or collapse of bulk material
Barrier failure resulting in a flood or a release of free-flowing solid or liquid
Visibility (for example, smoke particles in the air)
Biological hazards (viruses, bacteria from fecal matter and sludge, fungi, moulds)
Q: Why is working in a confined space more hazardous than working in other work spaces?
A: There is a smaller margin for error in a confined space. The process of hazard and risk identification and assessment is extremely important due to the variability and unpredictability of the conditions in confined spaces. Some examples include:
The entrance/exit might not allow the worker to get out in time if there was a flood or a collapse of free-flowing solid.
Self-rescue by the workers is more difficult.
Rescue of the victim is more difficult because the interior configuration of the confined space often does not allow easy movement of people or equipment within it. (Remember, an estimated 60% of the fatalities have been among the would-be rescuers.)
Natural ventilation alone will often not be sufficient to maintain breathable quality air.
Conditions can change very quickly.
The space outside the confined space can impact on the conditions inside the confined space and vice versa.
Work activities might introduce hazards that were not initially present.
Lack of communication between the workers in the space, the attendant, and the emergency response team.
Q: What should be done when preparing to enter a confined space?
The next step is to ask whether it is absolutely necessary for the work to be carried out inside the confined space.
Before entering any confined space, a trained and experienced person should identify and evaluate all of the existing and all of the potential hazards within the confined space.
Air quality testing should be performed by a trained worker (watch for part 2 of our Confined Space series next month to learn more about air quality in confined spaces).
Stay tuned for part 2 in this series about confined space next month!
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
You know what they say... Canada has two seasons: Winter and Construction. So, it is really important these days to think about cave-in protection, shielding, shoring, and similar safety measures.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: When is cave-in protection required for trenches/excavations?
A:Cave-in protection is required for trenches/excavations that are 5 feet (1.5 m) deep or greater. Saskatchewan Labour defines a temporary protective structure as "a structure or device in an excavation, trench, tunnel or excavated shaft that is designed to provide protection from cave-ins, collapse, sliding or rolling materials, and includes shoring, trench boxes, trench shields and similar structures."
Shoring is a system that supports the sides or walls. It is installing aluminum, steel, or wood panels that are supported by screws or hydraulic jacks. Wherever possible, install the shoring equipment as the excavation proceeds. If there is any delay between digging and shoring, no one should enter the unprotected trench. Some shoring systems can be installed without the workers entering the trench, and this should be done when possible because this provides additional safety for the workers.
In some cases, the trench or excavation walls are made of rock but are not entirely stable. Support the walls by using rock bolts, wire mesh, or a method that provides equivalent support.
Trench boxes, also called shields, are commonly used in open areas that are away from utilities, roadways, and foundations. They can be used to protect workers in cases of cave-ins, but not to shore up or support trench walls. However, they can support trench walls if the space between the box and the trench wall is backfilled with soil and compacted properly.
Q:What are the disadvantages of shielding when working in a trench?
A: If the space between the shield and the trench wall is not backfilled with soil and compacted properly, a cave-in or collapse may cause the shield to tilt or turn over. Therefore, the workers can be injured.
A trench box can be cumbersome to handle and might require additional equipment to move.
Trench production is usually slowed by the efforts to advance the shield.
The trench walls have to be stable enough to operate equipment near the top of the trench.
It should not be used if there are a lot of underground utilities or other obstructions.
Q: How many metres above the upper surface of a trench must a portable ladder extend?
A: A portable ladder must extend at least 1 metre (3 feet) above the upper surface of a trench. The top must also be tied at support points.
A safe means of entry/exit must be provided within 25 feet of all workers.
Q: What should you NOT do during an excavation?
A: Do not start digging before locating and de-energizing buried services.
Do not enter a trench before testing the air for hazardous gasses and vapours, or for the lack of oxygen.
Do not place sections of pipes, piles of soil, unused tools, timber, or any other materials within 1 metre from the trench's edge.
Do not rely on natural freezing to act as a method of soil stabilization.
Do not work under suspended or raised loads and materials.
Never stand behind a vehicle that is moving backwards.
Q: What are some of the other things that should be done when trenching/excavating?
A: Know the contact numbers of underground/utility services and have them readily accessible at the site.
Have pumps available at the site to remove water.
Ensure that the excavation has been marked to make the workers and others aware of the excavation (for example, a fence, flags, or other safeguards).
Ensure that proper barriers or guardrails are in place to protect anyone or any equipment from falling into the excavation or trench.
Ensure that workers are wearing appropriate personal protective equipment (for example, hard hats, respirators, safety boots, and hearing protection).
Ensure that high visibility vests or clothing are provided and worn by all exposed to vehicular traffic.
Ensure that first aid boxes are available at the site.
Ensure that a competent person inspects the excavation regularly (at the start of each shift before work begins and after any event that is likely to affect the strength or stability of the excavation).
Ensure that there is a competent person stationed at the surface of the trench to warn workers in the trench of danger and to provide help in the event of an emergency.
Also, it has been so hot this summer - make sure that you are staying hydrated!
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
What causes excess phosphorus and nitrogen to leach into raw water sources? What are normal readings of these parameters in raw source water? How can nutrient runoff of phosphorus and nitrogen be neutralized? We will discuss all of this!
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: What causes excess phosphorus and nitrogen to leach into raw water sources?
A:Excess phosphorus may come from partially treated and untreated sewage, runoff from agricultural sites, pollutants carried by precipitation, and application of some lawn fertilizers.
Excess nitrogen can come from animal manure, chemical fertilizers, pollutants carried by precipitation, sewer and septic systems, electric power generation, industry, transportation, and yard and pet waste.
Excess ammonia may come from nitrogen-fertilizer application, livestock operations, industrial processes, sewage infiltration, and cement mortar pipe lining.
Q:What are normal readings of phosphorus in a raw water source?
A: The natural levels of phosphorus in raw water sources usually range from 0.005 mg/L to 0.05 mg/L. In 1986, the Environmental Protection Agency (EPA) established the following recommended criteria for phosphorus: no more than 0.1 mg/L for streams that do not empty into reservoirs; no more than 0.05 mg/L for streams discharging into reservoirs; and no more than 0.024 mg/L for reservoirs.
Q: What are normal readings of nitrogen in a raw water source?
A: The natural levels of nitrogen in raw water sources vary substantially. Statistical analyses of water quality data suggest that appropriate reference levels range from 0.12 mg/L to 2.2 mg/L total nitrogen (nitrate-nitrite and ammonia, organic and reduced nitrogen). Natural ammonia levels in groundwater and surface water are usually below 0.2 mg/L, but many regions throughout the world have high levels of naturally occurring ammonia. During 1998 to 2010, samples from 393 private water wells in Saskatchewan were analyzed for ammonia and it was detected in more than 87% of the samples with an average value of 1.19 mg/L. The Guidelines for Canadian Drinking Water Quality state the guideline for nitrate as 45 mg/L and the guideline for nitrate-nitrogen as 10 mg/L. The guideline for nitrite is 3 mg/L and the guideline for nitrite-nitrogen is 1 mg/L. There is no guideline in the Guidelines for Canadian Drinking Water Quality for ammonia. The World Health Organization suggests that at a concentration above 1.5 mg/L ammonia can cause odour and taste problems.
Q: How can nutrient runoff of phosphorus and nitrogen be neutralized?
A: Source water protection is the first step. It is important to reduce or eliminate phosphorus and nitrogen from entering the water source via runoff, if possible.
If there is excess phosphorus in a raw water source, there are several substances that will absorb phosphate, immobilizing it and making it biologically unavailable (they are called phosphorus precipitants), some of them can effectively lower phosphorus concentrations in lakes, reservoirs, and ponds. They can "strip" phosphorus in a water column before it becomes available for absorption by algae or plants. After careful calculation, there is a measured dose of flocculant applied to "strip" the water column. it absorbs the phosphorus in the water column and precipitates to the bottom. If too much phosphorus is present in the water that has gone into the water treatment plant to be treated, alum is used in water treatment to mitigate phosphorus.
If there is excess nitrogen in a raw water source, a new and relatively inexpensive way to treat wastewater and drainage from agriculture lands is by using "denitrifying bioreactors". These bioreactors use common waste products, such as wood chips, to provide a food source for naturally occurring microorganisms. The microbes convert dissolved nitrogen into harmless nitrogen gas, which is then released into the atmosphere. Research results from New Zealand, and several locations in the United States all confirm that denitrifying bioreactors may be used in many settings, and operate well in a range of temperatures.
Separation of unionized-ammonia (NH3) from water can be achieved with air stripping in a packed tower by raising the pH of the water above 10 and increasing the temperature. Ammonia is soluble in water, so a high air/water ratio is required. Then, pH must be lowered again. An aeration tower can be used, the purpose of an aeration tower is to make oxygen react with reducing species in water - for example, iron and manganese. Ammonia does not react with oxygen in normal conditions. However, some unionized-ammonia, if present, ma also escape in an aeration tower due to mass transfer with air. Unfortunately, the most widely used method of removing ammonia during the drinking water treatment process is to add chlorine. In a process called "break-point chlorination" chlorine is continuously added to water until all of the ammonia and bacteria have been removed or, in other words, until the chlorine demand has been met. This works if there is only a small amount of ammonia, but if the ammonia concentration is more than 0.3 mg/L then so much chlorine would have to be added to get rid of it that it would result in dangerous levels of chlorination byproducts.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
Last month, we talked about accidents. This month, we are going to take a deeper dive into chlorine leaks.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: How can I check for chlorine leaks?
A: All joints and piping on chlorine lines should be checked with a plastic squeeze bottle containing 10% ammonium hydroxide solution. White smoke indicates a chlorine gas leak. Evidence of chlorine leaks can be detected by green or reddish brown deposits on metal.
Q:What should be done if a chlorine tank has a leak around the valve stem?
A: After using proper safety procedures you should tighten the packing nut. However, be careful to not over-tighten valves. Some operators tend to be over cautious and believe they are going the "extra mile" by over-tightening the valves. This might seem like a good, logical idea. However, it is not! When you over-tighten (torque) a valve, you are putting excessive pressure on the valve. Over time, excessive tension will cause the packing nut to crack. Over-tightening the valve can also put stress on the valve body and cause it to crack and release chlorine gas. It is important to tighten the valve according to the specifications provided by the valve manufacturer.
Q: An operator encounters a liquid chlorine leak in a one-ton container. What should they do to immediately help to reduce the effects of the leak?
A: Rotate the tank so the leak is positioned upwards, this will make it so that gas, and not liquefied gas, escapes. The gas can be knocked down with fog or fine water spray, one should not direct water at the spill or the source. Chlorine reacts with water to form hypochlorite and hypochlorous acid. Hypochlorite ions and hypochlorous acid are highly toxic and corrosive. Ventilate the area to prevent the gas from accumulating, especially if this is occurring in a confined space.
Q: What breathing devices can be used while dealing with chlorine leaks?
A: The only acceptable breathing device to wear when dealing with chlorine leaks is a self-contained breathing apparatus.
Q: At what temperature range is the fusible metal plug on a chlorine cylinder designed to open?
A: The fusible metal plug on the chlorine cylinder valve is a safety device and it is designed to melt at about 70ºC (158ºF). This safety device exists because heat could start an explosive chemical reaction. This safety plug protects the chlorine cylinder against excessive pressure, by melting and allowing the contents of the cylinder to escape when exposed to high temperature, allowing the gas to release before the hazardous reaction can begin. The fusible metal plug should not be tampered with under any circumstances.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
Prevention is key to avoiding accidents. However, it is still important to know what to do if various emergencies do happen. This month, we are talking about fires, explosions and electrical shock.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: What can cause a gas fire in a water treatment plant?
A: A build up of methane gas in the wastewater collection system can be explosive. Methane gases develop naturally in collection systems where there is little movement of air. If air and an ignition source come in contact with the methane gas, a violent explosion will happen. This explosion can cause immediate burns and/or death for the operators exposed to this hazard. Methane gas is also a byproduct of sludge digestion, which is a process used to treat the settled solids in the treatment plant.
Q:How can gas fires and explosions be prevented?
A: Combustible gas detection systems can alert personnel to a leak before it ignites and causes a blast or an explosion. When these detection systems are used in wastewater treatment plants, they are able to measure methane to determine whether a combustible level has been reached. Newer systems are able to trigger alarms, provide time for intervention or evacuation, release water mist if a gas cloud is forming, and/or record events. There are two different types of gas detection systems - line-of-sight and fixed-point. Line-of-sight gas detection systems use lasers or UV technology. These detectors monitor combustible gas levels between two points and are usually used to monitor open spaces that are above pipelines and valves. Fixed-point gas detection systems use either catalytic or infrared technology. These detectors use these technologies to activate when any gas comes in contact with them. These are usually installed in more high-risk areas and some models are even hand-held to help with use by crews entering high-risk zones. Gas detectors in hazardous areas must have approvals to be installed.
Smoke detectors should be located in areas where airflow is anticipated to come from sources that are likely to present fire risks. Smoke detectors should be installed in the sludge-processing areas of a wastewater treatment plant. Smoke detectors in hazardous areas also must have approvals to be installed. Some smoke detectors can self-test periodically. However, even with this option, these detectors should be tested manually on a regular basis.
Q: What can cause an electrical fire in a water treatment plant?
A: Electrical fires can start due to faulty electrical outlets or worn out sockets that are not properly grounded. As outlets and switches get older, the wiring behind them wears as well. Wires can loosen over time and can potentially break and cause a fire. Frequently overloaded circuit breakers and the installation of light bulbs that use too many watts for the light fixture can also cause electrical fires. Combine this with the environment of a water treatment plant where there is a lot of moisture, and you have a recipe for disaster.
Activated carbon is an electrical conductor and should not be allowed to accumulate as dust on open electrical circuits, to avoid potential for short-circuits. This dust should be considered as potentially explosive and appropriate precautions should be taken. The lower explosive limit for activated carbon dust is variously reported as 50 g/m3 and 140 g/m3, so this suggests that there is a small risk of dust explosions inside silos, conveyors, dust filters, and other items in the water treatment plant that handle dry activated carbon, and in the area immediately adjacent to this equipment.
Q: How can electrical fires be prevented?
A: Repair or replace loose outlets as soon as you notice them. You may need to have an electrician make the repair. Obviously, do not overload circuits and do not use light bulbs that use too many watts for the light fixture.
It is important to maintain proper exhaust in areas where activated carbon is handled and fed to prevent possible explosions. To minimize any risk of explosion related to activated carbon, dust filters should be provided and sources of ignition should be avoided. All equipment and piping used for dry handling of activated carbon should be earthed for static electricity.
Q: What if a fire does happen?
A: If you have any doubt about your ability to extinguish a fire, you should immediately evacuate.
If you know that you can extinguish the fire, you should use carbon dioxide to extinguish a gas fire.
In the case of an electrical fire, cut off the electricity. If the device that is causing the electrical fire is identified, and you can reach the cord and outlet safely, unplug it. Never use water to fight electrical fires because the water may transmit electrical shock to the user! If you know that you can extinguish the fire, you can use a fire extinguisher with C in its label (the C means that the extinguisher is equipped to handle Class C fires which are, essentially, electrical fires). If the electrical fire is small, you can extinguish it with sodium bicarbonate (baking soda).
Q: What can cause electric shock in water treatment plants?
A: Contact with “live” wires or defective electrical installations can cause electric shock.
Q: How can electric shock be prevented in water treatment plants?
A: Electrical equipment should always be checked for safety before beginning to do any work. If there is suspect equipment, a qualified electrician should be called to test the equipment.
When any piece of equipment is being worked on, the circuit breaker should be de-energized and locked out.
When doing work, proper rubber insulating gloves should always be used. Every insulating rubber glove is required to have a colour-coded label on the cuff that informs the user of the maximum use voltage on which that glove can be used. The number on the label must be greater than the voltage of the equipment with which the person is working. Selected properly, insulating rubber gloves will do the job of protecting the worker against electrical shock. Do not forget about leather protectors, they are a vital part of wearing and using rubber gloves correctly. Leather protectors are worn over electrical-insulating rubber gloves to protect rubber gloves from pinpricks or tears. The class of the leather protector should match the class of the electrical-insulating rubber glove. Wearing the proper size of gloves is also important. To determine glove size, measure the circumference of the hand around the knuckles and palm. This can be done by using a cloth tape measure or even by using a piece of string. If the circumference of the hand is 9 inches long, then the person’s hand is a size 9, if it is 11 inches long, then the person’s hand is a size 11, and so on. Allow for additional room if fabric liners are worn. If a second point of contact is possible, the worker must use additional insulating equipment, such as blankets, sleeves, and barriers that will insulate him or her from contacting energized and/or grounded equipment.
Q: How can someone help a victim of electric shock?
A: The first thing that must be done is to disconnect the power supply. Do not even touch the victim until you are sure that the power supply is turned off! Be especially careful in wet areas, as water conducts electricity. Check for the person’s response and breathing. It might be necessary to start cardiopulmonary resuscitation (CPR). Call 911 for an ambulance. If you are unsure of resuscitation techniques, or you just cannot think clearly, the ambulance call-taker will give you easy-to-follow instructions over the telephone, so you can increase the person’s chances of survival until the ambulance arrives. If the person’s breathing is steady and they are responsive, attend to their injuries. Cool the burns with cool running water for 20 minutes and cover with dressings, if available, that will not stick. Even plastic wrap is very suitable to cover burns as long as it is not applied tightly. Never put ointments or oils onto burns! If the person has fallen from a height, try not to move them unnecessarily in case they have spinal injuries. Only move them if there is a chance of further danger from the environment (and move them very carefully if you must move them). Talk calmly and reassuringly to the person.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
This month the forum is all about one of the most common causes of boil water advisories - turbidity!
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: What is turbidity?
A: Turbidity is the relative clarity of the water, ranging from perfectly clear and transparent to cloudy, hazy or opaque. It is caused by suspended matter such as clay, silt, finely divided organic and inorganic matter, coloured organic compounds, algae and other microscopic organisms.
Q:Why is turbidity important in drinking water treatment?
A: Waterborne disease-causing organisms such as bacteria, viruses, Giardia and Cryptosporidium often attach themselves to particles in raw water. The ability of particles suspended in water to shield attached organisms from disinfection is the most important health-related effect of turbidity. Excessive turbidity is often associated with unacceptable tastes, odours and colours in water and can represent a health concern where heavy metal ions, pesticides or waterborne disease causing organisms may attach to the suspended particles.
Q: How is turbidity measured?
A: Turbidity is measured by using an instrument that transmits a beam of light into a water sample, by measuring the amount of light scattered at right angles to the beam using a photoelectric sensor. There are other ways in which turbidity can be measured as well - a nephelometric turbidity meter which meets the American Water Works Association/American Public Health Association method 2130B and the United States Environmental Protection Agency method 180.1 and Great Lakes Instrument Method 2 are considered acceptable ways to measure turbidity. Meters are available as portable units, desktop instruments, as well as in a form that allows continuous measurement. Larger water treatment plants often use instrumentation that will provide continuous measurement, and this is required for certain waterworks.
Q: In what unit is turbidity measured?
A: Turbidity is most often measured in the Nephelometric Turbidity Unit (NTU). Other measurement units that are sometimes used are Jackson Turbidity Units (JTU) and Formazin Turbidity Units (FTU), but these are not equivalent and they are not accepted by the Water Security Agency (WSA).
Q: How sensitive are nephelometers?
A: Differences of 0.02 Nephelometric Turbidity Units (NTUs) can be determined.
Q: What are the Drinking Water Quality Standards for Turbidity?
A: The Drinking Water Quality Standards for Turbidity are affected by the source water and the treatment method.
Surface water that uses chemically assisted filtration and in which case the monthly source water average turbidity is 1.5 NTU or more should have less than 0.3 NTU for 95% of the discrete measurements or 95% of the time if continuous monitoring is employed, each calendar month. Turbidity should not exceed 0.3 NTU for more than 12 consecutive hours if continuous monitoring is employed and turbidity should never exceed the absolute maximum of 1.0 NTU.
Surface water that uses chemically assisted filtration and in which case the monthly source water average turbidity is less than 1.5 NTU should have less than 0.2 NTU for 95% of the discrete measurements or 95% of the time if continuous monitoring is employed, each calendar month. Turbidity should not exceed 0.2 NTU for more than 12 consecutive hours if continuous monitoring is employed and turbidity should never exceed the absolute maximum of 1.0 NTU.
Surface water that uses membrane filtration should have less than 0.1 NTU for 95% of the discrete measurements or 95% of the time if continuous monitoring is employed, each calendar month. Turbidity should never exceed the absolute maximum of 0.3 NTU.
Surface water that uses slow sand or diatomaceous earth filtration should have less than 1.0 NTU for 95% of the discrete measurements or 95% of the time if continuous monitoring is employed, each calendar month. Turbidity should not exceed 1.0 NTU for more than 12 consecutive hours if continuous monitoring is employed and turbidity should never exceed the absolute maximum of 3.0 NTU.
Groundwater should have less than 1.0 NTU for 95% of the discrete measurements or 95% of the time if continuous monitoring is employed, each calendar month.
Q: What are the requirements for monitoring for turbidity?
A: In the case of a groundwater source, if the population is 500 or less the turbidity needs to be measured at least once per day, if the population is 501-2,000 the turbidity needs to be measured one to two times per day, if the population is 2,001-5,000 the turbidity needs to be measured two times per day, if the population is 5,001-15,000 the turbidity needs to be measured three times per day, if the population is 15,001-50,000 the turbidity needs to be measure four times per day, and if the population is greater than 50,000 the turbidity needs to be measured continuously.
In the case of surface water and blended source water, if the population is 500 or less the turbidity needs to be measured at least once per day, if the population is 501-2,000 the turbidity needs to be measured one to two times per day, if the population is 2,001-5,000 the turbidity needs to be measured four times per day, and if the population is greater than 5,000 the turbidity needs to be measured continuously.
Q: What should we do if the influent water turbidity increases?
A: Treatment and disinfection processes should be adjusted. If the turbidity changes were not predicted, the situation should be investigated to determine the cause.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
This month the forum is all about Groundwater Under Direct Influence of Surface Water (GUDI)!
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: When is a water source said to be Groundwater Under Direct Influence of Surface Water (GUDI)?
A: A water source is said to be GUDI when it has significant occurrence of insects or other macro-organisms, algae or large diameter pathogens (such as Giardia lamblia and Cryptosporidium), or significant and relatively rapid shifts in water characteristics (including turbidity, temperature, conductivity or pH factors) that closely correlate to climatological or surface water conditions.
Q:What water sources are most likely to be GUDI?
A: Wells located near surface waters or poorly constructed springs are most likely to be GUDI.
Q: What changes in terms of monitoring requirements when a water source is determined to be GUDI?
A: If a water source is determined to be GUDI the monitoring requirements are the same as those for surface water. Filtered surface water needs to have continuous turbidity monitoring equipment on each filter effluent line. Also, in the case of community systems and public facilities, surface water or GUDI needs to have an alarm connected to their chlorine residual treated water continuous monitoring equipment.
Q: What changes in terms of treatment requirements when a water source is determined to be GUDI?
A: The minimum level of treatment for drinking water when the source is groundwater is disinfection. Whereas, when the source is surface water or GUDI, the minimum level of treatment for drinking water is filtration combined with disinfection. There are many other requirements as well, and we refer you to the Protocol for Centralised Drinking Water Systems in First Nations Communities.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
Happy New Year! This month, Deon is answering all of your questions about soft water!
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: Is it important to have soft water?
A: Soft water is preferred for cleaning, as it does not tend to cause soap scum or mineral stains. Also, it is a more efficient and effective cleaning agent, so you might save money on your water bill by not having to re-wash clothes or dishes, and you might be able to feel fully cleaned and rinsed even when taking short showers. Soft water can also be very beneficial for your hair and skin while bathing or showering.
While most softened water is completely safe to drink, the amount of sodium in the water that has been softened via sodium exchange will depend on the hardness of the original water. People on restricted sodium intake diets should account for increased levels of sodium in softened water.
Q: How is iron and manganese removal accomplished in the sodium water softening process?
A: Sodium is exchanged for iron and manganese. The iron and manganese are then removed from the softener resin bed through backwashing and regeneration.
Q: What solution is used to regenerate a zeolite softening unit?
A: A zeolite softening unit will replace calcium and magnesium ions with sodium ions. Therefore, the iron and manganese do need to be removed from the softener resin bed through backwashing and regeneration. Salt is used for regeneration. A high concentration of sodium ions needs to be applied to the resin to replace calcium and magnesium. The resin is treated with a 10% sodium chloride solution. During regeneration, a large excess of regenerant (approximately three times the amount of calcium and magnesium in the resin) is used. However, the regeneration is less efficient at the higher regenerant levels and, therefore, softener operating costs increase as the regenerant level increases.
Q: How can lime and soda ash be used to soften hard water?
A: Lime is used to remove chemicals that cause carbonate hardness, while soda ash is used to remove chemicals that cause non-carbonate hardness. When lime and soda ash are added, hardness-causing minerals form nearly insoluble precipitates. Calcium hardness is precipitated as calcium carbonate, while magnesium hardness is precipitated as magnesium hydroxide. These precipitates are then removed by conventional processes of coagulation/flocculation, sedimentation and filtration. Due to the fact that these precipitates are very slightly soluble, some hardness (about 50 mg/L to 85 mg/L) remains in the water. This hardness level is desirable as it prevents corrosion problems that are associated with water being too soft and having little to no hardness. This water softening process does not add sodium to the drinking water.
Q: When lime and soda ash are used to soften hard water, why is the water sometimes aerated before the softening begins?
A: When water, especially groundwater, has a high carbon dioxide concentration, the water is often pretreated with aeration before softening begins in order to remove the excess carbon dioxide and lower the lime requirements.
Q:Why are lime-soda ash softening and zeolite softening acceptable methods of corrosion control for relatively small systems?
A: Both lime-soda ash softening and zeolite softening reduce the hardness of water. Hard water can cause corrosion in water pipes and home appliances. Therefore, softening the water controls corrosion.
Q: What is the correct order for regeneration of a zeolite softening unit after it has been removed from service?
A: The regeneration cycle of a sodium zeolite softener consists of four steps in the following order:
1. Backwash
2. Regeneration (brining)
3. Displacement (slow rinse)
4. Fast rinse
Q: How does sodium hydroxide (caustic soda) remove calcium and magnesium?
A: Caustic soda can be used in place of lime and sodium carbonate in the calcium and magnesium ions' removal process. In this case, the reduction of alkalinity is only 50% that of lime and sodium carbonate softening processes. Caustic soda is easier to handle than lime, only one chemical might be required, and the quantity of calcium carbonate sludge that is produced is less. However, it does have a higher cost, it is a hazardous chemical, and sodium is added to the treated water.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
Water Movement is starting a series called "Wednesdays with Warren". This week's video of expert Indigenous Water Operator Warren Brown shows us how to complete an accurate chlorine residual test, and you can watch it here: https://www.youtube.com/watch?v=h2qNJfwvqdk. You can catch all of the future videos as they come out on Water Movement YYC's website here: https://www.watermovementyyc.com/forum.
We hope that you have happy holidays and that you have healthy drinking water! This month, we answer questions about healthy drinking water.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: What is healthy drinking water?
A: Drinking water should meet all of the Guidelines for Canadian Drinking Water Quality. It should appear clear, and have no undesirable taste or odour.
Q: Colour is an aesthetic objective, so what does that have to do with the safety of my drinking water?
A: Colour in and of itself is purely aesthetic, but when it has a visible tint to it, it is usually due to the presence of decaying organic material or inorganic contaminants such as iron, copper, or manganese.
If the water has a red or brown tint to it, this is indicative of iron or manganese in the water. Iron or manganese in the water can stain sinks and discolour laundry.
If the water has a yellow tint to it, this is indicative of suspended organic particles. This causes health risks due to the chlorination causing organic material to combine with the chlorine to form compounds called trihalomethanes.
If the water has a blue or green tint to it, this is indicative of copper in the water. Copper can cause staining of fixtures and laundry. High copper content (30 ppm or higher) can cause vomiting, diarrhea, and general gastrointestinal symptoms.
If the water is cloudy, has a white tint to it, or is foamy, this can be indicative of turbidity. Turbidity is a critical parameter in drinking water because bacteria, viruses and parasites can attach themselves to the suspended particles and the particles can interfere with disinfection by shielding contaminants from the disinfectant. However, usually milky white or cloudy water is caused by tiny air bubbles. If your water is white, fill a clear glass with water and set it on the counter - if the water starts to clear at the bottom of the glass first, the cloudy or white appearance is trapped air. Trapped air is not a health threat and should clear in a few minutes.
If your water suddenly changes colour - no matter what colour it becomes - it could indicate a public health concern.
Q: What do taste and odour problems indicate?
A: If a taste or odour occurs at every water faucet on the property, the cause is probably the main water supply. However, if it occurs only in certain faucets then the problem is the fixtures or pipes supplying those specific faucets.
Petroleum, gasoline, turpentine, fuel, or solvent odours are rare, but potentially serious. If you smell any of these in the water then do not use the water! A leaking underground storage tank may be contaminating your water supply. Contact your water utility or health authority.
Metallic taste is often caused by iron or copper leaching into the water from the pipes. Less common metals, such as zinc and manganese, could also be a problem. If you are concerned, contact your water utility.
Chlorine, chemical, or medicinal tastes or odours can be caused by the addition of chlorine to the water or the interaction of chlorine with a build-up of organic matter in your plumbing system. This is not usually an immediate health threat. If the taste or odour seems strong to you, contact your health authority or your water utility.
Sulfur or rotten egg odour is usually caused by bacteria growing in your sink drain or in your hot water heater. Naturally occurring hydrogen sulfide in your water supply might also cause this odour. To determine the cause, put a small amount of water in a narrow glass, step away from the sink, swirl the water around inside the glass, and smell it. If the water has no odour, the likely problem is bacteria in the sink drain. If the water does have an odour, it could be from your hot water heater. There is an element in your hot water heater designed to protect it from corrosion. Sometimes the element causes sulfide smell as it deteriorates over time. A licensed plumber might be able to determine the issue. If you rule out the drain and the water heater, and the odour is definitely coming from the tap water, do not use it. Contact your water utility or your health authority.
Mouldy, musty, earthy, grassy, or fishy odour is usually caused by bacteria growing in a sink drain or from organic matter such as plants, animals, or bacteria that are naturally present in lakes and reservoirs during certain times of the year. For example, cyanobacteria such as Anabaena produce compounds with unpleasant odours and tastes. You can evaluate the source of this problem by putting a small amount of water in a narrow glass, stepping away from the sink, swirling the water around inside the glass, and smelling it. If the water has no odour, the likely source is the sink drain. If the water does have an odour, the source could be organic matter in your drinking water. While harmless, this material can affect the taste and smell of your drinking water even at very low concentrations.
Salty taste is usually caused by high levels of naturally occurring sodium, magnesium, or potassium. If you live in a coastal area, this might be due to seawater seeping into the fresh water supply. This could be a health threat. You should contact your water utility or health authority.
Q: Why is it important for water to not have unpleasant tastes or odours, if the issue is not a health threat?
A: Water is the healthiest drink - it does not contain any sugar, artificial sweeteners, artificial colours, or artificial flavours. If the water has an unpleasant taste or odour, people will not want to drink it and they will often turn to something less healthy - such as pop or juice. Even if they turn to bottled water, that is not good because bottled water has grave effects on the environment and it has also been found to contain double the microplastic particles when compared to tap water. Bottled water is also less regulated than tap water.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
Researchers have demonstrated that a fall in water system pressure can suck in groundwater bearing bacteria and viruses, leading to contamination of the water supply and creating a health risk. This month, we answer questions about low and negative pressure and the risks caused by this issue.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: What is the acceptable range for incoming water pressure?
A: Many plumbing professionals suggest 50 psi as the ideal, and this is also the default setting for most pressure regulators. Larger homes require a higher incoming pressure rating than small homes, as water will slow down slightly each time it encounters a bend in the pipes. Depending on where you live, the water pressure could vary greatly as it comes in from the supply lines. The incoming water pressure should never be over 100 psi and it should never be below 20 psi.
Q: What happens if the water pressure is too low or even becomes negative?
A: If negative pressure develops near a leaking pipe joint there is a very real risk of contaminated water getting into the system. An additional risk is that if there is a complete vacuum, extremely high pressure is created as the vacuum is collapsed by the returning water column, and this can cause stress on pipe joints - increasing the risk of bursts.
Q: What are the pressure requirements for water systems?
A: According to the Water Security Agency's Water Pipeline Design Guidelines, the normal operating pressure range for water pipelines is 50 psi to 80 psi. The maximum pressure should not exceed 100 psi, in order to protect household piping. Under special circumstances where the main lines are allowed to exceed 100 psi, the adjacent lateral pipelines or service lines must be protected with pressure reducing valves.
The minimal acceptable water pressure at water pipeline withdrawal points is 14 psi if all serviced connection withdrawal points are protected by an air gap backflow preventer or equivalent. The minimal acceptable water pressure at all other withdrawal points is 20 psi.
Q: What causes negative pressure?
A: Negative pressure can be cause by changes in flow rates due to valve operation, by pump trip or (in worst-case scenarios) by power failure. Each change in flow rate leads to a series of alternating high and low pressure spikes, risking the creation of negative pressure along the main.
Q: How can negative pressure be prevented?
A: Negative pressure can be prevented by ensuring that surge vessels are appropriate to the main they are protecting and that they are correctly controlled. Well-maintained and well-designed surge vessels should be a key part of engineers' and water systems operators' due diligence.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
It was two years ago today that Dr. Hans Peterson passed away suddenly from a heart attack. He founded Safe Drinking Water Foundation (SDWF) along with a few other international scientists and he founded Safe Drinking Water Team in 2015. He most definitely has not been forgotten and he is most definitely missed every day. We wanted to remember him with you today.
His obituary stated, "Dr. Hans, as he was affectionately known, had one dream, and that was to provide water treatment solutions to even the smallest community with the poorest quality raw water source."
Here are some of his most memorable quotes:
"Any raw water source is a smorgasbord for bacteria. As long as we supply ice cream, steak, French fries and Greek salads to the bacteria we will continue to fail to produce safe drinking water even if we meet every regulation in the book."
"I started to count the number of people who now have safe drinking water due to our work, more than 100,000."
"I started to dream about a world that had abandoned expensive and ineffective chemical treatment processes in favour of inexpensive and effective biological treatment."
Chlorination continues to be an area of difficulty for water systems operators, especially new operators. Therefore, to help you out, Deon has answered questions about chlorination this month.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: How much chlorine needs to be added to the water?
A: It is vital that sufficient chlorine is added to the water to meet the chlorine demand and to provide residual disinfection. The chlorine that does not combine with other components in the water is free (residual) chlorine. The breakpoint is the point at which free chlorine is available for continuous disinfection. In piped water systems, all water must be chlorinated and have a free chlorine residual of no less than 0.2 mg/L at all points throughout the distribution system. It is important to test the residual chlorine level at the furthest points in the distribution system. Therefore, enough chlorine needs to be added such that breakpoint is reached and there is sufficient free (residual) chlorine for there to be at least 0.2 mg/L of free chlorine residual throughout the distribution system.
Q: Can you tell me more about breakpoint chlorination?
A: Sure! Some of the demands on chlorine (some of the things that will require more chlorine to be added in order to reach breakpoint chlorination) are iron, manganese, organic matter, and ammonia. In fact, when chlorine reacts with some of these components, such as organic matter and ammonia, chlorination by-products are formed (such as chloramines and trihalomethanes). Trihalomethanes have been linked to cancer and Health Canada's regulations set 100 ug/L as the limit for human consumption.
Q: What are the guidelines for water sampling in terms of testing for free chlorine?
A: Water system operators are responsible for operating and maintaining drinking water systems and for implementing effective sampling and testing to continuously monitor drinking water quality. The water system operator of a small community system needs to test one treated water sample per day and one distribution system sample per week. If the system is not a small system and the water source is surface water or groundwater under the direct influence of surface water (GUDI), the treated water needs to have continuous monitoring equipment with an alarm and one distribution system sample needs to be tested per week. If the system is not a small system and the water source is groundwater, there needs to be continuous monitoring of the treated water and at least one distrubution system sample per day needs to be tested. Consecutive samples should not be taken from the same sampling location.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
Few people can think clearly and logically in a crisis, so it is important to do so in advance, when you have time to be thorough.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: If an operator was in a room where chlorine gas is leaking and the operator does not have a mask, what should the operator do?
A: The vapours are heavier than air, so do not crouch down. The operator should keep their mouth closed, keep their head as high as possible, and quickly walk out of the room, holding their breath if possible.
Q: If ammonia vapour is passed over a chlorine leak in a cylinder valve, how is the presence of the leak indicated?
A: The presence of the leak is indicated by a white cloud or vapour.
Q: What are some of the health risks of exposure to chlorine gas?
A: Exposure to low concentrations of chlorine gas can cause burning eyes, nose and throat; redness in the face; sneezing and coughing.
Exposure to high concentrations of chlorine gas can cause tightness in the throat and difficulty breathing.
1,000 parts per million is fatal after a few breaths. Concentrations of about 400 ppm and higher are usually fatal over 30 minutes or less. Concentrations as low as 40 ppm can cause a toxic pneumonitis and/or acute pulmonary edema to develop.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
Sometimes people complete actions and tasks the way they were taught to do them, but they do not know why they do them that way. To have a deeper understanding of water testing and water treatment topics, it is important to know the reasons for which tasks are to be done in certain ways.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: Why is the coliform bacteria test used to indicate the bacteriological quality of water?
A: Coliform bacteria are non-pathogenic bacteria that occur in the feces of warm-blooded animals. Their presence in a water sample indicates that harmful pathogenic bacteria may also be present. Coliforms are found in numbers corresponding to the degree of fecal pollution, are relatively easy to detect, and are overall hardier than pathogenic bacteria. Therefore, coliforms are important “indicator organisms” in an environmental sample to assess water quality prior to or in place of culturing other organisms.
Q: Why is treated water always used for backwashing?
A: Treated water is always used for backwashing so that the filter bed will not be contaminated. This treated water can be delivered from elevated storage tanks designed for this purpose or it can be pumped in from the clearwell.
Q: Why do prepared water sample bottles used for collecting samples for bacteriological examination contain sodium thiosulfate crystals?
A: Sodium thiosulfate is a dechlorinating agent that neutralizes the residual chlorine or other halogen and prevents continuation of bactericidal action during sample transit.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
In Quebec, the Ministère de l'Environnement et de la Lutte contre les changements climatiques has adjusted its expectations in situations where COVID-19 affects personnel in drinking water production and distribution. Those responsible for drinking water distribution systems must make sure that they have competent operators to run the system, particularly in situations where regular personnel is affected by COVID-19. Also, laboratories accredited by the MELCC have been advised to give priority to the analysis of drinking water samples sent to them. The MELCC will exercise leniency regarding certain administrative obligations during the pandemic. However, absolutely no compromise should be made with respect to the microbiological quality monitoring of distributed drinking water.
Here is the most recent news regarding COVID-19 and wastewater:
There have been some updates to information regarding COVID-19 and wastewater since we sent you information that we gathered from World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) for the First Nations and Rural Water Operators Forum in March. As you likely have heard by now, the virus that causes COVID-19 has been detected in sewage. In fact, it has been found at surprisingly high levels in sewage (https://cen.acs.org/biological-chemistry/infectious-disease/Novel-coronavirus-found-surprisingly-high/98/i15). Studying coronavirus in sewage can be an early warning system as researchers can find a sharp rise in viral concentrations in sewage before cases explode in the clinic. This could, therefore, be a cheap, noninvasive tool to warn against oubreaks (www.sciencemag.org/news/2020/04/coronavirus-found-paris-sewage-points-early-warning-system). Also, monitoring influent could provide better estimates than testing can of how widespread the coronavirus is, because wastewater surveillance can account for those who have not been tested and have only mild or no symptoms (https://www.nature.com/articles/d41586-020-00973-x).
Q: Does the virus that causes COVID-19 persist in drinking water? A: While the presence of the virus that causes COVID-19 in untreated drinking-water is possible, it has not been detected in drinking-water supplies. Furthermore, other coronaviruses have not been detected in surface or groundwater sources and, thus, the risk of coronaviruses to water supplies is low.
The virus that causes COVID-19 is enveloped and, thus, less stable in the environment compared to non-enveloped human enteric viruses with known waterborne transmission (such as hepatitis A). One study found that other human coronaviruses survived only two days in dechlorinated tap water and in hospital wastewater at 20°C. In comparison, high levels of removal (>4 log) of the influenza virus were found in drinking-water after contact time of only five minutes and a chlorine residual of 0.3 mg/L. Other studies found similar removals in days to weeks. Significant (99.9%) removal of coronaviruses was observed in two days in primary sewage effluent at 23°C, two weeks in pasteurized settled sewage at 25°C and four weeks in reagent grade water at 25°C. Higher temperature, high or low pH, and sunlight all facilitate virus reduction.
Q: How do we keep water supplies safe? A: Several measures can improve water safety, starting with protecting the source water; treating water at the point of distribution, collection or consumption; and ensuring that treated water is safely stored at home in regularly cleaned and covered containers. Such measures can be effectively planned, implemented and monitored using water safety plans.
Conventional, centralized water treatment methods that use filtration and disinfection should inactivate the COVID-19 virus. Other human coronaviruses have been shown to be sensitive to chlorination and disinfection with ultraviolet (UV) light. For effective centralized disinfection, there should be a residual concentration of free chlorine of ≥ 0.5 mg/L after at least 30 minutes of contact time at pH < 8.0. A chlorine residual should be maintained throughout the distribution system.
In addition to effective water treatment, water utility managers can adopt several other preventive measures, as part of a broader water-safety planning approach. These measures include ensuring adequate stocks of chemical additives and consumable reagents for water-quality testing, ensuring that critical spare parts, fuel and contractors can still be accessed and that there are contingency plans for staff and training to maintain the required supply of safe drinking-water.
In places where centralized water treatment and safe piped-water supplies are not available, a number of household water treatment technologies are effective in removing or destroying viruses, including boiling or using high-performance ultrafiltration or nanomembrane filters, solar irradiation and, in non-turbid water, UV irradiation and appropriately dosed free chlorine.
Q: How do we safely dispose of greywater or water from washing Personal Protective Equipment (PPE), surfaces and floors? A: Utility gloves or heavy-duty, reusable plastic aprons should be cleaned with soap and water, and then decontaminated with 0.5% sodium hypochlorite solution each time they are used. Single-use gloves and gowns should be discarded as infectious waste after each use and not reused, and hand hygiene should be performed after PPE is removed. If greywater includes disinfectant used in prior cleaning, it does not need to be chlorinated or treated again. However, it is important that such water is disposed of in drains connected to a septic system, to a sewer, or in a soak-away pit. If greywater is disposed of in a soakaway pit, the pit should be fenced off within the health facility grounds to prevent tampering and to avoid possible exposure in the case of overflow.
Q: What are the water quality and quantity requirements for handwashing? A: The quality of water used for handwashing does not need to meet drinking-water standards. Evidence suggests that even water with moderate faecal contamination when used with soap and the correct technique can be effective in removing pathogens from hands. However, efforts should be made to use and source water of the highest quality possible (e.g. an improved water source). Reported quantities of water used for handwashing that have enabled reduction of faecal contamination ranges from 0.5 litres to 2 litres per person. Also, the quantity of water used has been associated with less viral contamination of hands. Where water is limited, hands can be wetted with water, the water then turned off while lathering with soap and scrubbing for at least 20 seconds, and then the water can be turned on again to rinse. Water should always be allowed to flow to a drainage area or receptacle, and hands should not be rinsed in a communal basin, as this may increase contamination.
Q: Is the virus that causes COVID-19 found in feces (stool)? A: The virus that causes COVID-19 has been found in the feces of some patients diagnosed with COVID-19. However, it is unclear whether the virus found in feces may be capable of causing COVID-19. There has not been any confirmed report of the virus spreading from feces to a person. Scientists also do not know how much risk there is that the virus could be spread from the feces of an infected person to another person. However, they think this risk is low based on data from previous outbreaks of diseases caused by related coronaviruses, such as severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS).
Q: Can the COVID-19 virus spread through sewerage systems? A: The virus that causes COVID-19 has been found in untreated wastewater. Researchers do not know whether this virus can cause disease if a person is exposed to untreated wastewater or sewerage systems. There is no evidence to date that this has occurred. At this time, the risk of transmission of the virus that causes COVID-19 through properly designed and maintained sewerage systems is thought to be low.
Researchers have analyzed the available information which suggest that standard municipal and individual septic system wastewater treatment practices should inactivate the virus that causes COVID-19. CDC is reviewing information on COVID-19 transmission as it becomes available. Guidance will be updated as new evidence is assessed.
Q: Should wastewater workers take extra precautions to protect themselves from the virus that causes COVID-19? A: Recently, the virus that causes COVID-19 has been found in untreated wastewater. While data are limited, there is no information to date that anyone has become sick with COVID-19 because of exposure to wastewater.
Standard practices associated with wastewater treatment plant operations should be sufficient to protect wastewater workers from the virus that causes COVID-19. These standard practices can include engineering and administrative controls, hygiene precautions, specific safe work practices, and PPE normally required when handling untreated wastewater (including protective outerwear, heavy-duty gloves, boots, goggles or a face shield, and a mask). They should perform hand hygiene frequently. They should avoid touching their eyes, nose or mouth with unwashed hands, and they should practice social distancing while working. No additional COVID-19-specific protections are recommended for workers involved in wastewater management, including those at wastewater treatment facilities.
Safe Drinking Water Team keeps those affected by the virus in our hearts.
After we sent out the email message in March regarding water and wastewater and COVID-19 we received some replies from town and city employees regarding keeping their water systems operators healthy and what organizations can do if their water systems operators become ill in order to mitigate risk to the community's ability to provide safe water and wastewater treatment.
Q: Have any water systems employees tested positive for COVID-19?
A: In the United States, there have definitely been a number of water systems employees who have tested positive for COVID-19.
Q: What have cities/towns done after a water systems employee tested positive?
A: Followingthe San Antonio Water System employee contracting the virus (likely during working hours), a deep cleaning of the employee's work area was conducted and the San Antonio Water System is continuing to sanitize all locations to ensure the safety of employees. Fellow employees were notified of the situation.
Following the Lower Valley Water District employee's positive test result, 25 employees of the Lower Valley Water District were placed under quarantine for having direct and indirect contact with the employee. Most of the employees who were impacted were from the field operations team (some were operators, some were pipe layers, they were all working together). The water district also worked to notify two contractors with whom the employee worked. They made a plan to start conducting daily health screening of all employees entering their facilities the following week and stated that employees who do not pass the health screening will be sent home and directed to isolate.
Following the Pinellas County, Florida storm water employee testing positive for COVID-19 officials contacted other employees who worked closely with the infected employee, based on records. All of the other employees reported that they felt fine but, in an abundance of caution, they were told to stay home. The building where the employees worked was disinfected by a professional cleaning company. A county cleaning crew also disinfected the vehicle used by the infected employee. Furthermore, the county took steps to limit the contact that staff at the landfill scale house have with the public by waiving flat fee transactions until further notice and requiring customers to pay with credit cards.
Following the Santa Clara Valley Water District employee in the communications department testing positive for COVID-19 at least eight other employees, including their CEO, and one of their elected board members were in self-quarantine as a result. Water district officials contacted Santa Clara County Public health officials and had crews deep clean office areas and conference rooms where the employee had worked. Many employees started working from home, facilities are being cleaned more often, staff members are washing their hands regularly and staying six feet apart. A water district board of directors meeting took place but it was broadcast by video conference and public attendance was limited. Some meetings were delayed.
Q: What are cities/towns doing to prevent water systems operators from becoming ill?
A: Internet research did not turn up any water systems operators in Canada who have tested positive for COVID-19. Here are some of their strategies to prevent water systems operators from contracting the virus:
Canadian Water & Wastewater Association has developed a Water Sector Pandemic Action Plan. In this action plan, it is recommended that:
Projects involving contractors on site be suspended;
Access for all plant tours and scheduled visits of groups be suspended;
Access be limited to all but essential services which should be further defined as Critical, Vital, Necessary and Desired;
Meeting people face to face be avoided;
The telephone, email and the Internet be used to conduct business as much as possible even when participants are in the same building;
Unnecessary travel be avoided;
Non-essential meetings and training sessions be cancelled or postponed;
The alternate SCADA site be prepared to be used remotely, if required;
Telecommuting be arranged so employees can work from home or work flex hours to avoid crowding at the workplace;
All employees wash hands frequently with soap and water;
Coughs and sneezes are covered with tissues;
All employees have up to date vaccinations;
Sick employees be encouraged to stay home;
Employees have medical clearances prior to returning to work from travel or from an illness;
All hard surfaces including control panels, keyboards, etc. be wiped down and disinfected;
All capital projects be suspended;
Preventative maintenance be reduced to critical equipment only;
Sampling be limited to collection from auto samplers and essential samples;
Staff focus only on Critical and Vital services;
All policies on physical distancing be implemented;
Illness and expenses related to the pandemic be monitored and documented;
Contact be maintained with suppliers and modifications of treatment to conserve chemicals and energy be considered;
Water and Wastewater facilities be prepared for potential impacts to operations (including staff absenteeism);
Staff communicate frequently with customers regarding the safety of the water supply per provincial and federal health authorities;
Employees receive cross training of essential skills before a staffing shortage develops;
Staff be educated in personal hygiene and be diligent regarding workplace cleanliness;
Restrictions or protection for face-to-face interactions be considered (including customer service and payments);
Reviews of current minimum stock quantities on part inventories be conducted to ensure no shortages will hinder plant operation (this includes all personal protective equipment); and
Staff of Water and Wastewater facilities work with their Director of Emergency Management (DEM) to ensure that they are recognized as "Essential-Critical" to the continued operation of their municipality. (Source: https://cwwa.ca/wp-content/uploads/2020/03/CWWApandemicAction.pdf)
Government of Canada has issued risk-informed decision-making guidelines for workplaces and businesses during the COVID-19 pandemic. Some of the additional information in this document that might be useful includes:
Emphasis of communication about risk to staff/clients;
Providing options to the medically at risk to reduce social contacts at work, such as teleworking arrangements, if possible;
Giving consideration to more stringent self-monitoring and other measures to reduce exposure and transmission to others in the case of returning travellers who are asymptomatic and deemed essential workers, this includes consulting with the Public Health Authority, conducting a risk assessment considering local epidemiology, response goal, critical infrastructure resources, and potential positive and negative impacts of recommendations;
Considering involving the local Public Health Authority in decision-making about workplace/business closure;
Considering going cashless and encouraging hand hygiene after exchange of money or items;
Reinforcing safe food handling practices;
Avoiding sharing communal office equipment/supplies (for example, tablets and electronic devices);
Avoiding potlucks and buffets where serving utensils, plates, trays and other objects may be handled by multiple people;
Reviewing and revising (as needed) your business continuity plans to prioritize key functions in the event of high workplace absenteeism;
Encouraging employees to take public transit at non-peak times or to use a personal vehicle if possible to limit contact with others;
Updating emergency contact information of employees and contractors;
Preparing to institute flexible workplace and leave policies for employees who are sick, in self-isolation, or caring for family members;
Developing a risk communication plan to ensure effective and efficient communication with employees, contractors and clients;
Considering relaxing sick leave policies that support employees in self-isolating when ill, exposed to cases, or returning from international travel, such as suspending the need for medical notes to return to work;
Providing mental health support services;
Using a physical barrier (e.g., cubicle, Plexiglas window), if possible;
Creating a plan for rapid isolation of a symptomatic employee;
Identifying an area where employees can be isolated if they become ill at the workplace;
Ensuring that health care professionals onsite are using appropriate personal protective equipment (PPE) and infection prevention and control (IPC) measures, as per usual procedure;
Reminding employees not to touch their faces;
Actively monitoring travel advisories and providing information about the risk of travel;
Cancelling all non-essential travel outside of Canada; and
Q: Do you have any other news to share about water and COVID-19?
A: Yes! We definitely do!
The COVID-19 pandemic could threaten drinking water safety in buildings that have been closed. Water left to sit in pipes can get contaminated with toxic heavy metals and bacteria - like the kind that causes Legionnaires' disease, another illness that affects the lungs. Read more here: https://www.wfyi.org/news/articles/covid-19-closures-could-make-water-unsafe-in-offices-schools
A new test to detect SARS-CoV-2 in the wastewater of communities infected with the virus is being developed by researchers from Cranfield University and the Institute of Geochemistry. The wastewater-based epidemiology (WBE) approach might provide an effective and rapid way to predict the potential spread of COVID-19 by picking up on biomarkers in faeces and urine from disease carriers that enter the sewer system. Read more here: https://www.watercanada.net/wastewater-test-could-provide-early-warning-of-covid-19/
Two researchers, Haizhou Liu, an associate professor of chemical and environmental engineering at the University of California, Riverside; and Professor Vincenzo Naddeo, director of the Sanitary Environment Engineering Division at the University of Salerno, have called for more testing to determine whether water treatment methods are effective in killing SARS-CoV-19 and coronaviruses in general. Researchers have called for more research to determine the best ways to keep SARS-CoV-19 out of the water cycle. They also suggest that developed nations should finance water treatment systems in the developing world to help prevent future COVID-19 pandemics. Read more here: https://www.sciencedaily.com/releases/2020/04/200403132347.htm
We have gathered information from the United States Environmental Protection Agency, World Health Organization and Centers for Disease Control and Prevention for this special issue of the First Nations and Rural Water Operators Forum.
Q: Is drinking tap water safe? A: It is recommended that people continue to use and drink tap water as usual. Drinking water guidelines require treatment at public water systems to remove or kill pathogens, including viruses.
Q: Do I need to boil my drinking water? A: Boiling your water is not required as a precaution against COVID-19.
Q: Do I need to buy bottled water or store drinking water? A: It is recommended that people continue to use and drink tap water as usual. At this time, there are no indications that COVID-19 is in the drinking water supply or will affect the reliable supply of water.
Q: Can I get COVID-19 from wastewater or sewage? A: There is no evidence to date that the COVID-19 virus has been transmitted via sewerage systems, with or without wastewater treatment.
Q: Do wastewater treatment plants treat COVID-19? A: Yes, wastewater treatment plants treat viruses and other pathogens. COVID-19 is a type of virus that is particularly susceptible to disinfection. Standard treatment and disinfection processes at wastewater treatment plants are expected to be effective.
Q: Will my septic system treat COVID-19? A: While decentralized wastewater treatment (i.e., septic tanks) do not disinfect, it is expected that a properly managed septic system will be able to treat COVID-19 the same way it safely manages the other viruses often found in wastewater. Additionally, when properly installed, a septic system is located at a distance and location designed to avoid impacting a water supply well.
Q: Does the COVID-19 virus persist in drinking water? A: While persistence in drinking water is possible, there is no current evidence from surrogate human coronaviruses that they are present in surface or groundwater source water or transmitted through contaminated drinking water. The COVID-19 virus is an enveloped virus, with a fragile outer membrane. Generally, enveloped viruses are less stable in the environment and are more susceptible to oxidants, such as chlorine. While there is no evidence to date about survival of the COVID-19 virus in water or sewage, the virus is likely to become inactivated significantly faster than non-enveloped human enteric viruses with known waterborne transmission (such as adenoviruses, norovirus, rotavirus and hepatitis A).
Q: How do we keep water supplies safe? A: The COVID-19 virus has not been detected in drinking water supplies, and based on current evidence, the risk to water supplies is low. Laboratory studies of surrogate coronaviruses that took place in well-controlled environments indicated that the virus could remain infectious in water contaminated with feces for days to weeks. A number of measures can be taken to improve water safety, starting with protecting the source water; treating water at the point of distribution, collection or consumption; and ensuring that treated water is safely stored at home in regularly cleaned and covered containers.
Conventional, centralized water treatment methods that utilize filtration and disinfection should inactivate the COVID-19 virus. Other human coronaviruses have been shown to be sensitive to chlorination and disinfection with ultraviolet (UV) light. As enveloped viruses are surrounded by a lipid host cell membrane, which is not robust, the COVID-19 virus is likely to be more sensitive to chlorine and other oxidant disinfection processes than many other viruses, such as coxsackieviruses, which have a protein coat.
Q: How do we safely manage wastewater and fecal waste? A: There is no evidence to date that the COVID-19 virus has been transmitted via sewerage systems with or without wastewater treatment. Furthermore, there is no evidence that sewage or wastewater treatment workers contracted severe acute respiratory syndrome (SARS), which is caused by another type of coronavirus that caused a large outbreak of acute respiratory illness in 2003. As part of an integrated public health policy, wastewater carried in sewerage systems should be treated in well-designed and well-managed centralized wastewater treatment works. Each stage of treatment (as well as retention time and dilution) results in a further reduction of the potential risk.
Q: Can the COVID-19 virus spread through drinking water? A: The COVID-19 virus has not been detected in drinking water. Conventional water treatment methods that use filtration and disinfection, such as those in most municipal drinking water systems, should remove or inactivate the virus that causes COVID-19.
Q: Is the COVID-19 virus found in feces? A: The COVID-19 virus has been detected in the feces of some patients diagnosed with COVID-19. The amount of virus released from the body (shed) in stool, how long the virus is shed, and whether the virus in stool is infectious are not known.
The risk of transmission of COVID-19 from the feces of an infected person is also unknown. However, the risk is expected to be low based on data from previous outbreaks of related coronaviruses, such as several acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). There have been no reports of fecal-oral transmission of COVID-19 to date.
Q: Can the COVID-19 virus spread through sewerage systems? A: At this time, the risk of transmission of the virus that causes COVID-19 through sewerage systems is thought to be low. Although transmission of COVID-19 through sewage may be possible, there is no evidence to date that this has occurred. This guidance will be updated as necessary as new evidence is assessed.
SARS, a similar coronavirus, has been detected in untreated sewage for up to 2 to 14 days. In the 2003 SARS outbreak, there was documented transmission associated with sewage aerosols. Data suggest that standard municipal wastewater system chlorination practices may be sufficient to inactivate coronaviruses, as long as utilities monitor free available chlorine during treatment to ensure it has not been depleted.
Wastewater and sewage workers should use standard practices, practice basic hygiene precautions, and wear personal protective equipment (PPE) as prescribed for current work tasks.
Q: Should wastewater workers take extra precautions to protect themselves from the COVID-19 virus? A: Wastewater treatment plant operations should ensure workers follow routine practices to prevent exposure to wastewater. These include using engineering and administrative controls, safe work practices, and PPE normally required for work tasks when handling untreated wastewater. No additional COVID-19-specific protections are recommended for employees involved in wastewater management operations, including those at wastewater treatment facilities.
Safe Drinking Water Team keeps those affected by the virus in our hearts.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: How does the size of the filter media affect the filter capacity or run?
A: General filtration theory states that the more filter grains you have in a filter or the smaller the filter media's average size, the better your filtrate quality will be because the effective filtration of particulate will be greater. However, there are limitations in relation to both grain size and filter bed depth. When grain size becomes too small, the clean filter head loss is impractically high and filter run times are too short, typically due to surface binding of the fine media. When using deep bed filters, such as those that are six feet deep, with 1.5 mm sand media, the effluent quality may be similar to that obtained from use of finer filter sand and the clean head loss will be reduced. However, the implementation of filter beds that are six feet deep has installation and operational costs that may not be feasible.
The filter capacity and filtrate quality produced by different media grain sizes and at different bed depths has been studied extensively. After decades of filtration design and operation, many engineers and utilities have determined that one key design criterion is the ratio of the bed depth (L) to the average filter grain effective size (d). As the L/d ratio increases, the removal of particle efficiency increases.
The development of high surface area or ‘rough engineered ceramic’ media and the use of improved surface area measurement technologies allows for alternative bed depth to grain size ratios.
Q: What is the purpose of the top anthracite layer in multimedia filters?
A: It allows the largest dirt particles to be removed near the top of the media bed and this allows the entire bed to act as a filter, allowing much longer filter run times between backwash and more efficient particulate removal.
Q: Why are gravel layers in multimedia filters used?
A: The job of these layers is to support the lighter layer above and to provide efficient drainage. The gravel layers also trap and strain particles in the water.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
The holidays are over (taking down the holiday decorations is heartbreaking!)
You're trying to keep resolutions (and likely not enjoying it)
It's dark almost 24/7
It's so cold you can't feel your face when you walk outside
There is only one statutory holiday, and it is the 1st of the month
By now, it feels like it's January 74th, so it feels like New Year's Day was a long time ago
There's not much we can do about most of the problems in January (we're sorry!), but at least Deon may be able to solve some of your problems in your water treatment plant!
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: When checking the sedimentation basin immediately before filtration, the water systems operator noticed an extreme amount of tiny floc carryover. What should the water systems operator have done?
A: The water systems operator should have checked that the correct amount of coagulants are being applied. The water treatment plant operator might also want to consider using a polymer coagulant instead of inorganic coagulants as they produce smaller volumes of more concentrated, rapidly settling floc. Floc formed from use of a properly selected polymer will be more resistant to shear, resulting in less carryover and a cleaner effluent. Selection of the proper polymer requires considerable jar testing under simulated plant conditions, followed by pilot or plant-scale trials. All polymers must be approved for potable water use by regulatory agencies.
Tube or plate settlers are often added to settling basins to improve their efficiency. Tube settlers can be installed in most conventionally designed settling basins and, in many cases, result in twice the basin’s original settling capacity.
Q: What does it indicate if debris is found in the filter bed after backwashing a sand filter?
A: This indicates that there might have been a turbidity or colloidal breakthrough associated with longer backwash return. The turbidity and head loss at backwash, coagulation and flocculation process, sedimentation operation, hydraulic filter overloading, and whether a filter has been taken offline causing other filters to run at too high of a rate should all be checked. The backwash cycle and the prefilter process control should be adjusted as required.
Q: What happens to operations if the floc that reaches a filter is too large?
A: The filters will begin to deteriorate, become clogged, and produce poor-quality filtered water. Filters cannot perform well under these conditions and the problems with prior units need to be resolved.
Q: If microscopic examination of your raw water indicates the presence of a large number of diatoms, cyanophycae and chlorophyceae, what should you do?
A: Diatoms are single-celled algae and they are the only organism on the planet with cell walls that are composed of transparent, opaline silica. Cyanophycae are blue-green algal-like bacteria and chlorophyceae are blue algal-like bacteria. Algal overgrowths on surface water are treated with a registered copper sulfate product at the rate of one kilogram copper sulfate by weight per 2.1 million litres of water.
It has been found that when the algae density in raw water is less than 106 cells per litre, more than 98% of algae can be removed with a coagulant dosage of 13 mg/L. When the algae density is increased to more than 1060 cells per litre (during algae outbreak periods), 96% or more of algae can be removed using a coagulant dosage of approximately 20 mg/L and a chlorine dosage of approximately 4.0 mg/L.
Biological water treatment can also be very effective in treating raw water that contains diatoms, cyanophycae and chlorophyceae. The first surface water biological treatment plant in the world was installed at Saddle Lake Cree Nation in northern Alberta. Saddle Lake has many issues with algae and the biological treatment plant is able to treat the water to a level such that it exceeds all current Guidelines for Canadian Drinking Water Quality as well as all other international regulations and standards.
Q: What are some possible causes if you are having problems achieving adequate disinfection?
A: The raw water might contain contaminants that interfere with the disinfection process, there might be insufficient contact time in the holding tank, and ammonia can decrease disinfection efficiency. Bacteria, viruses, and parasites such as Giardia and Cryptosporidium can attach themselves to the suspended particles in turbid water and these particles then interfere with disinfection by shielding contaminants from the disinfectant.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
This month, Deon Hassler will help you be ready for 2020 by explaining how to complete tasks in the best possible way.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: What methods are most effective in removing high iron content from a well water supply?
A: The best way to remove high iron content from groundwater is to use a biological water treatment system. Biological iron removal is much more efficient and cost effective than conventional physio-chemical iron removal.
Q: How do I determine the correct disinfectant dosage and contact time in order to maintain the desired level of residual in the system?
A: Disinfectant dose is determined by the amount of disinfectant (usually chlorine) required to kill pathogens and for oxidation of reducing agents like iron, manganese, and hydrogen sulfide. The chlorine dose can be determined by adding excess chlorine to water and then by measuring the difference between the added amount of chlorine and the residual chlorine after a specified time period.
The chlorine requirement, or chlorine dosage, is the sum of the chlorine demand and the desired chlorine residual. It can be expressed mathematically as Chlorine dosage (mg/L) = Chlorine demand (mg/L) + Chlorine residual (mg/L).
Contact time is a product of a disinfectant residual concentration (C), in mg/L and the effective disinfectant contact time (T), in minutes. The CT value is developed to relate the levels of inactivation under different operational conditions. For all true groundwater systems, a CT value that provides a minimum of a 4-log virus reduction/inactivation must be achieved. In the case of surface water or Groundwater Under Direction Influence (GUDI) systems, a CT value that provides a minimum of a 0.5 log Giardia and 2-log virus reduction/inactivation must be achieved.
To complete CT calculations, the following operating or design conditions must be applied to determine the effective contact time provided at a water treatment plant:
The peak hourly flow rate (typically the pump peak flow);
Minimum normal operating level of the storage reservoir, clearwell or tank;
The baffling factor (BF) for the chlorine contact tank;
Minimum disinfectant residual measured at the end of each disinfection segment, or the minimum disinfectant residual allowed in the Permit to Operate;
Minimum temperature of the water undergoing disinfection; and
Maximum pH of the water undergoing disinfection.
For groundwater treatment plants and surface water treatment plants with chlorine disinfection the first step of the process is to collect data and calculate actual CT and then the next (and final) step is to compare actual CT to required CT.
For surface water treatment plants with multiple disinfection segments the steps are to calculate the CT value for the first disinfection segment, calculate the Giardia log credit for the first disinfection segment, calculate the CT value for the second disinfection segment, calculate the Giardia inactivation log for the second disinfection segment, and then to calculate the total log inactivation of Giardia.
A: The coagulation/flocculation process can be adjusted in order to improve sedimentation. Coagulants should be rapidly and thoroughly mixed in water and they need accurate dosing equipment to function efficiently. The retention time can be up to two days and it is better to have a longer retention time. Sedimentation can be improved by placing parallel-connected baffles in the vicinity of the inlet in order to improve hydraulic conditions.
Q: For how long should the person collecting the sample allow the water to run before filling the sample bottle when collecting a distribution-system sample for bacteriological testing?
A: The person collecting the sample (who should have washed their hands with soap and warm water!) should let the cold water run constantly for at least two minutes before they collect the sample.
Q: How should an operator test for residual chlorine?
A: The most common test is the dpd (diethyl paraphenylene diamine) indicator test, using a comparator. This test is the quickest and simplest method for testing chlorine residual. With this test, a tablet reagent is added to a sample of water, colouring it red. The strength of colour is measured against standard colours on a chart to determine the chlorine concentration. The stronger the colour, the higher the concentration of chlorine in the water.
Q: When is the best time to perform a flushing program on the mains?
A: At the beginning of spring and during daylight hours. Flushing is routinely conducted in spring because the demand for water tends to be at its lowest and cold weather is not an issue. It is safer for staff to work on the streets in daylight and daylight provides better visibility to see when all of the sediment has been flushed out and the water is running clear.
Q: What should be done after a new water main is installed and pressure tested?
A: After a new water main is installed and pressure tested the next step is for continuous feed chlorination to be used and introduced through the by-pass using the water from the distribution system. Chlorine concentration range should be within the range of 80 ppm to 120 ppm. An appropriate high count instrument needs to be used to verify high chlorine concentrations.
Next, the watermain needs to be flushed so that all of the superchlorinated water is removed from all points of the watermain that is being commissioned. This includes all hydrant leads, services, and sample point locations. All superchlorinated water must be neutralized before being discharged into the natural environment. Chlorine residuals must be taken and they must be 1.0 mg/L (combined chlorine) or greater and be reflective of the trend of the community. After 24 hours of contact time, chlorine high count must be taken at all sample points prior to flushing the watermain. At the end of this 24 hour period, all sample points must meet at least 50% concentration from the original chlorination day. If any one sample fails, then rechlorination of the watermain is required.
After final flushing and before the new watermain is connected to the existing water distribution system, two consecutive sets of passing microbiological samples must be taken at least 16 hours apart. At least one set of samples must be collected from every 370 metres (1200 feet) of the new watermain, plus one set from the end of each branch. Sample points must be constructed with appropriate fittings. All water distribution samples will be conducted by an operator.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
This month, Deon Hassler will explain what causes various problems.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: What causes breaking up of floc particles?
A: The water being mixed too rapidly can cause breaking up of floc particles. It is important for the mixing intensity of the downstream flocculator to not be set too high.
Also, check that the pH level of the source water has not changed. If the pH level has changed then adjust the pH level to target levels as indicated by jar test.
Check the alkalinity of source water and the holding time in the coagulation tank because the cause might be alkalinity being consumed by coagulant. In this case, adjust the alkalinity and make process adjustments, as necessary.
Q: What causes filter media to crack?
A: Sometimes filter runs are too long (backwashing is done too infrequently). It is important to check the filtration rates to be sure that they are within the design specifications and to remove the top one inch of media and replace it with new media. Replacing the top one-inch of media with new media keeps the top of the media from collecting the floc and it seals the entrance into the filter media.
Q: What causes backsiphonage?
A: Backsiphonage is caused by negative pressure from a vacuum (or partial vacuum) in the supply piping. This might be caused by main breaks, flushing, pump failure, high demand, or emergency firefighting water drawdown. Since backsiphonage is induced by drops in distribution system pressure, maintaining positive and stable pressure reduces the risk of backflow. Minimizing pressure spikes through the use of variable speed pumps and proper valve opening and closing procedures may reduce the frequency of main breaks that cause backsiphonage. Regular inspection of pipelines may identify conditions that could lead to main breaks such as frozen valves, advanced corrosion, and small leaks, and allow them to be repaired before they lead to main breaks. Regularly cleaning and flushing pipelines may also reduce buildup and growth of biofilms that may promote corrosive conditions that can cause pipeline leaks and eventually breaks.
Backflow prevention assemblies include pressure vacuum breakers (PVBs), spill resistant vacuum breakers (SVBs), double check valve assemblies (DCVAs), and reduced pressure principle backflow assemblies (RPs). The selection of any particular assembly or device is a function of the hazard assessment that balances the likelihood of backpressure and backsiphonage and the potential contaminants involved.
Q: What causes black stains on plumbing fixtures?
A: Black stains on plumbing fixtures are usually caused by sulfur bacteria, which also cause a rotten egg odour (because they produce hydrogen sulfide gas). Optimizing ion exchange treatment systems can remove sulfate from water and a shock chlorination/disinfection of the water can temporarily control hydrogen sulfide. Proper use and maintenance of a carbon filter can remove low levels of hydrogen sulfide that occur with no bacterial problems. They can also be caused by manganese. Consider additional water treatment involving the addition of polyphosphates or silicates.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
This month, Deon Hassler will answer a wide variety of questions.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: What effect does turbidity have on disinfection requirements?
A: Turbidity is an important water quality indicator because bacteria, viruses, and parasites such as Giardia and Cryptosporidium can attach themselves to the suspended particles in turbid water. These particles then interfere with disinfection by shielding contaminants from the disinfectant. The amount of alum used in the water treatment process should be adjusted when turbidity increases or decreases.
Q: What factors promote the corrosive behaviour of water supplies?
A: If the pH level is low (the water is acidic) the water will be more corrosive. One reason the pH of the water might be too low is that carbon dioxide gas forms carbonic acid when dissolved in water and this lowers the pH of the water. A minimum amount of alkalinity is necessary to provide a stable pH throughout the distribution system in order to help control corrosion. Temperature of the water influences several water quality parameters, including dissolved oxygen solubility, solution viscosity, diffusion rates, activity coefficients, enthalpies of reactions, compound solubility, oxidation rates, and biological activities. These parameters, in turn, influence the corrosion rate.
Q: Of what is water that has a pH of less than seven likely to contain high amounts?
A: Carbon dioxide is the most common cause of acidity in water. Photosynthesis, respiration, and decomposition all contribute to pH fluctuations due to their influences on CO2 levels. Carbon dioxide exists in water in a dissolved state, but it can also react with water to form carbonic acid. Carbonic acid can then lose one or both of its hydrogen ions and the released hydrogen ions decrease the pH of the water.
Q: Over which water quality indicators do operators have the greatest control in a conventional surface water treatment plant?
A: Operators have the most control over turbidity because they can use a variety of methods to remove it (sand filtration and alum work well). They also have a lot of control over microbiological exceedences because procedures and treatment plants are designed to identify and treat such incidents.
Q: During the night, how does algae affect the pH of the water?
A: Algae increase the pH level of the water during the night. This is because, at night, oxygen is consumed through respiration and carbon dioxide is released, which lowers the pH level of the water.
Q: After chlorination, what does the free chlorine residual include?
A: The free chlorine residual includes combined concentrations of HOCl (hypochlorous acid), OCl-(hypochlorite) and Cl2 (chlorine gas).
Q: What are tubercles and on what types of pipes can they form?
A: Tubercles are corrosion deposits that reduce the diameter of a pipe and are caused by crevice corrosion often encountered in cooling water systems. They can form in steel and cast iron pipes. Tubercles are not formed in oxygenated water on more corrosion-resistant materials such as stainless steel, brass, copper-nickel, titanium, and aluminum.
Q: What does the term “C value” mean?
A: The C value is derived by using the Hazen-Williams equation that relates the flow of water in a pipe with the physical properties of the pipe and the pressure drop caused by friction. Lower C values represent smoother inside surfaces of pipes.
The Hazen-Williams Equation is V = k C (D/4)0.63S0.54 where S = hf/L and Q = VπD2/4, where k is a unit conversion factor and equals 1.318 for English units (feet and seconds) and 0.85 for SI units (metres and seconds), C = Hazen-Williams Coefficient, and D = Pipe inside diameter.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
This month, Deon Hassler will answer questions about the effects of temperature.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: What is affected by the water temperature in ion exchange reactions?
A: In an ion exchange reaction, the ability of water to expand the resin is greatly affected by temperature. Less flow is required to expand the bed with cold water than is required to expand the bed with warm water. Therefore, resin bed expansion should be checked regularly and the flow rate needs to be adjusted in order to maintain proper bed expansion.
Q: When winter arrives, the water temperature drops. What operational problem is this likely to cause at a filtration plant in terms of coagulation?
A: Generally, water temperature and settling rate are directly proportional to each other. As water temperature increases, settling rate increases and as water temperature decreases, settling rate decreases. This is due to the fact that when the water is colder the density differential between water and floc is less, so settling is slower. Overcoming problems of cold water floc can be accomplished by adding weighing agents (coagulant aids). Coagulant aids are chemicals that are used to add density to slow-settling floc and to strengthen floc formation. Some coagulant aids are activated silica (this strengthens floc at low temperatures), bentonite clay, and synthetic organic polymers.
Q: If the water temperature decreases, what effect does this have on chlorination?
A: When the water temperature decreases, the capabilities of chlorine are reduced. In general, every drop of 10 degrees Celsius in water temperature will double the required contact time.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
This month, Deon Hassler will answer questions about pumps, valves, and bearings.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: There is a pinging sound coming from a pump, what could be causing this?
A: This could be caused by air cavitation in the pump impeller assembly, by a damaged impeller, by mineral or other debris in the pump impeller, or by air in the well piping or water supply piping. The water systems operator should check that the pump motor and pump assembly bearings and mounts are in good condition and should replace these if they are worn.
Q: What is the primary purpose of pressure-reducing valves between water system pressure zones?
A: The main purpose is reducing incoming water pressure for the area of houses on that part of the distribution waterline. Other names of the valve are pressure regulator, pressure sustaining valve, or singer valve.
Homeowners do not want water pressure that is too high coming into their homes as it can create plumbing issues and cause unnecessary stress on appliances like dishwashers and clothes washers.
Q: How does an operator inspect valves to determine whether they are holding properly?
A: The operator can test that the valves are holding properly by slightly closing off the discharge valve as pressure builds up. The operator should hear the pressure-reducing valve open and discharge. On some systems, there is a sight glass on the discharge lines.
Q: How often should grease-lubricated bearings be regreased after initial full-service operation?
A: Always grease bearings according to manufacturer’s instructions. Too much grease volume in a bearing cavity will cause the rotating bearing elements to begin churning the grease, pushing it out of the way, resulting in energy loss and rising temperatures. Remember that overgreasing bearings can cause the electrical motor to overheat!
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
This month, Deon Hassler will answer questions about chlorine.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: How can free chlorine be removed from water?
A: Since chlorine is a gas at room temperature, you can simply let it evaporate out by putting it in a pitcher for 24 hours. If you want to speed the process up, you can boil the water for 20 minutes. You could use a granular activated carbon filter. Reverse osmosis systems have granular activated carbon filters and they are able to remove the chloramines as well. Another option is to dissolve potassium metabisulfite, sodium metabisulfite, sodium bisulfite, sodium thiosulfate, or ascorbic acid (vitamin C) (1 teaspoon per 1 gallon - 3.8 L - of water) into the water in order to remove both chlorine and chloramine.
Q: Will chlorine in chemical feed barrels lose its strength over time?
A: Many chemical feed barrels are not airtight. Therefore, the chlorine can lose its strength and dissipate over time. It will dissipate into the atmosphere at a rate of approximately 0.75 mg/L per day. Water systems operators should make the barrels as airtight as possible to prevent dissipation of chlorine. Also, since there might still be dissipation of chlorine, it is important to have a way to ventilate the water treatment plant.
Q: What are the key differences between free chlorine and total chlorine?
A: Free chlorine is the chlorine that has not yet reacted with contaminants (like bacteria, parasites, etc.) and is still available to kill contaminants. Total chlorine is the total of both free chlorine and the chlorine that has already reacted with contaminants.
Q: Can chlorine cause more harm than good when incorporated in water as a form of disinfection? What harmful aspects can arise?
A: Chlorine is necessary in order to kill bacteria, parasites, viruses etc. However, when chlorine reacts with things like that it forms chlorination by-products like Trihalomethanes, which are carcinogenic (cancer causing). When the water has a high level of ammonia more chlorine is required in order to achieve breakpoint chlorination and more chlorination by-products will be formed.
Q: When mixing chlorine and water, is this the formula to use? Cl2 + H2O -> HOCl + HCl. What roles do HOCl and HCl play in the disinfection process?
A: Yes, that is the formula to use. HOCl is hypochlorous acid and HCl is hydrochloric acid. Hypochlorous acid is a weak acid (but it is the stronger of the two acids) that has oxidizing properties that form when chlorine dissolves in cold water. Hydrochloric acid is a strong pH reducer and it is suitable for lowering the pH. The amount of each compound present in the water is dependent on the pH level of the water prior to the addition of chlorine. At lower pH levels, the hypochlorous acid will dominate. The combination of hypochlorous acid and hypchlorite ions makes up what is called 'free chlorine'. Free chlorine has a high oxidation potential and is a more effective disinfectant than other forms of chlorine, such as chloramines.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
This month, Deon Hassler will answer many questions - from what to do if you have lead pipes to updated guidelines and standards.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: I have been hearing about something called "Saskatchewan First Nations Water Association" - what is it?
A: The Saskatchewan First Nations Water Association Inc. is a registered Saskatchewan non-profit organization that has the mission to provide an opportunity for education, training, networking and skills enhancement to the staff involved in the day-to-day operation and maintenance of water and wastewater systems. For more information, please visit www.fnwa.ca.
Q: If I want to see a biological water treatment plant and how it works, how could I do that?
A: Contact an operator of a First Nations water treatment plant that is biological. You can find a list of the communities that have biological water treatment plants here: https://www.safedrinkingwaterteam.org/ibrom.
Q: From where could I get a TDS meter and/or a pH meter?
A: You can contact Safe Drinking Water Foundation at 1-306-934-0389 or info@safewater.org to ask about purchasing one or more TDS and/or pH meters.
Q: What guidelines/standards are being updated soon? What will be the guidelines/standards for those components? What if my current water treatment plant cannot produce water that meets those guidelines/standards?
A: On May 10, 2019 the Guidelines for Canadian Drinking Water Quality (issued by Health Canada) aesthetic guideline for manganese was lowered to 0.02 mg/L and a new health guideline for manganese was set at 0.12 mg/L.
Recently, the guideline for lead was reduced from 0.01 mg/L to 0.005 mg/L.
If the water treatment plant cannot produce water that meets the new guidelines/standards then let the environmental health officers know about this. They and the community will request an upgrade from the federal government.
Q: How do I find out about upcoming changes to guidelines/standards?
Q: My community cannot produce enough safe drinking water to meet the needs of everyone who relies on our system (especially in summer when people water lawns, etc.) what should I do?
A: As long as the water treatment system is operating to the design capacity, we should focus on water conservation. Engineers design to a ten year population growth. Some communities grow faster than others. Investigation into potential water main breaks that have not been located, household plumbing leaks, or abandoned homes should be done. Then, we should notify water treatment plant operators or public works managers so they can look into reservoir expansion and upgrading the capacity of the water treatment system.
Q: Water treatment plant operators keep leaving our community to work in bigger cities instead - what can we do about this problem?
A: Recruit the youth to be water treatment plant operators. If you pay the water treatment plant operators more (and pay them for the overtime they work, for being on call, etc.) they will be less likely to leave.
Q: Is ultraviolet light disinfection effective? What problems do ultraviolet light disinfection prevent?
A: Yes, it alters pathogens such that they cannot reproduce and they are essentially killed. Then, these pathogens cannot cause infection. This DNA modification is called inactivation. They also destroy at least 99.99% of harmful microorganisms, including E. coli, Cryptosporidium and Giardia.
However, chlorine is still required in order for parasites, bacteria and viruses to be killed throughout the distribution lines. At least 0.1 mg/L of residual chlorine is required throughout the distribution system.
Q: There are lead water distribution pipes in my community. I know that Saskatoon and Regina are also experiencing this issue. What can I do about this problem in my small community?
A: If you live in a rural community and you suspect that you have lead pipes then talk to the members of your town council about this issue. In the meantime, you can let the water run for 3-5 minutes before using it for drinking or cooking in order to reduce your exposure to lead. You can also install an on-the-tap filtration system or under-the-sink filtration system that filters the water finely enough to remove the lead. Another option is to purchase one of the few, new pitcher-style water filtration systems that removes lead from the water.
If you have lead pipes, lead solder, or lead faucets in your home then you need to hire a plumber and have these items replaced with pipes and plumbing fixtures that do not contain lead.
The amount of lead going into your water is diminished if the pH of the water is 7.0 or higher. This is up to the water treatment plant operator to monitor and adjust.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
This month, Deon Hassler will answer a variety of questions - from knowing when it is time to clean in place RO membrane filters to how long Confined Space Certificates last!
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: How do you know it is time to clean-in-place reverse osmosis (RO) membrane filters?
A: Keeping records from the first day of operation of new filters is essential! As time goes by, parameters will eventually change as more water passes through the filters. By monitoring Silt Density Index (SDI), differential pressure, normalized permeate flow, percent rejection, and pressure drop coefficiency, the water treatment plant operator can catch the indication of fouling potential and/or measure the extent of fouling and/or scaling. Monitoring raw/feed water pressures, flow, conductivity, total dissolved solids (TDS), and oxidation-reduction potential (ORP) are also a must in record keeping.
Q: What is conductivity? Is it the same as TDS?
A: Conductivity is the degree to which a substance is able to conduct electricity. While pure water cannot hold an electrical charge, water that contains minerals and salt can due to stronger bonds between molecules. Therefore, conductivity is related to the amount of salt and minerals in the water. TDS, while related, is not the ability to conduct electricity but, rather, the amount of inorganic salts (mainly calcium, magnesium, potassium, sodium, bicarbonates, chlorides, and sulfates) and organic matter dissolved within the water, which results in the ability to conduct electricity.
Q: What is ORP?
A: ORP is the acronym for oxidation-reduction potential (also called redox potential). It is a measure of the tendency of a chemical species to acquire from or lose electrons to an electrode and, thereby, be reduced or oxidized. It is critical to measure ORP in order to ensure that all of the chlorine and other oxidizing chemicals have been removed. If present, these chemicals can physically attack polyamide RO membranes, creating leaks through which dissolved salts can pass.
Q: Why is pH important in drinking water?
A: The pH in most RO water treatment systems will drop below 6 because removing the minerals makes the water acidic. The operational guideline for pH is a range of 7.0 to 10.5 in finished drinking water. A pH of less than 7.0 is acidic and can corrode pipes, which can then leach lead and copper out of plumbing. If a sudden pH change is present in a distribution system, it can indicate a water quality issue.
Q: How long do Confined Space Entry Certificates last?
A: According to Saskatchewan Health and Safety, Confined Space Entry Certificates (and all other safety certificates) do not expire. However, if you feel the need to refresh your memory then you should take a certified course.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
This month, Deon Hassler will be trying to help you maintain your water treatment plant in good working order by answering some questions related to chemical injection systems.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: Why do chemical injection systems need to be cleaned?
A: Chemical injection systems do plug up on occasion and they require regular preventative maintenance. When you are doing maintenance, you should be checking for cracks or breaks in the lines. Check and clean all the valves and the dosing pump. Clean and maintain the pump injection point.
Q: How often do chemical injection systems need to be cleaned?
A: It depends on the system. Therefore, they should be cleaned as recommended by the operating instructions. A good plan would be to schedule preventative maintenance on a monthly basis, or as often as needed to prevent plugging. You should flush chemical residue from the pump monthly. The frequency of required maintenance will differ from chemical to chemical.
Q: How do you clean a chemical injection system?
A: Clean them according to the operating instructions. Cleaning liquid chlorine lines can be done using hot water or vinegar. Taking apart injectors, check the valves and the dosing pumps and clean or replace those parts. Alternatively, if you are in a rush, running hot water through the injection system sometimes works. This is also a good time to calibrate the dosing pump.
Q: What are the potential causes of no chlorine in the distribution lines?
A: In terms of the chemical injection system, the most likely cause is dosing pump failure, which could be caused by several issues. Check the usage of the chemical in the barrel, is the level in the barrel decreasing? Did an injection line come off, most likely due to a plugged injector? Check the valves, make sure the pump is lifting liquid up to the pump. Check the power to the electrical plug. Some other potential causes of low chlorine residual are that the chlorine solution could have lost strength due to light, heat, or long storage time or there could be destruction of chlorine residual by inorganic reducing compounds, i.e. Fe++, Mn++, H2S or by organic material.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
This month, Deon Hassler will be answering questions related to running a water treatment plant.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: Why is it important to test the raw water?
A: Raw water is subject to taste and/or odour and treatment process adjustments should be made when this happens. It is also subject to algal growths and, in this case, treatment process adjustments need to be made. Furthermore, testing the raw water can inform the water treatment plant operator regarding dosages of different chemicals.
In summary, the characteristics of the raw water can change (especially if it is raw surface water) and you need to know exactly what you are treating in order to be able to treat it properly.
Q: How do you calculate potassium permanganate dosing?
A: Potassium permanganate should be dosed into the raw water supply in the ratio of 1.0 mg/L of potassium permanganate per 0.5 mg/L of soluble manganese and 1.0 mg/L of potassium permanganate per 1.0 mg/L of iron.
If you are treating taste and odour, use doses of potassium permanganate ranging from 0.25 mg/L to 20 mg/L according to the manufacturer's instructions.
Q: How do you calculate how much greensand needs to be added to the pressure filter?
A: There should be a 4-6 inch layer of fine gravel at the bottom of the filter tank, then the greensand should be added until the tank is 50% to 65% full.
Here is how you can calculate how much greensand needs to be added:
(π)(radius of filter)2(h) = volume of greensand
Where h is the height of the filter tank multiplied by 0.5 to 0.65 (depending on where in the 50% to 65% range full you want the filter to be) minus the height of the layer of gravel at the bottom of the filter tank.
Q: Why is antiscalant used?
A: Antiscalant is used to keep water hardness from precipitating during reverse osmosis treatment of water. It is used to cause the suspended solids that may be present in the water to coagulate and settle out. It is highly effective in preventing the membranes from scaling.
Q: How do you conduct jar testing for breakpoint chlorination?
A: While breakpoint chlorination usually happens at a chlorine dosage 10 times the raw water ammonia concentration, more details about the shape of the breakpoint chlorination curve can be determined by jar testing. In order for the test results to be accurate, it's important to use fresh chlorine stock. Breakpoint chlorination is achieved when a chlorine dose increase results in an increase of chlorine residual.
These are the steps involved in jar testing:
Step 1 - Plan Your Jar Test to Solve the Problem
Define the variables you want to involve in your test. Try to make the jar test as similar to what happens in the water treatment plant as possible (mixing energy, settling time, etc.).
Step 2 - Organize Equipment and Chemicals
Clean jar test apparatus.
Gather the equipment that you will need and SDS sheets for the chemicals that will be used.
Freshly mix chemicals in appropriate dilutions. Dilution should generally be done with distilled, deionized water (DDW) to prevent chemical reactions.
Step 3 - Collect Water Sample for Testing
Collect sample from the right location - the point at which chlorination will be added. 5 gallons is enough for one jar test.
Step 4 - Dose Each Jar
Inject each pre-prepared syringe or pipette quickly.
Add chemicals in the same order as they are added in the plant and in the same treatment process as in the full-scale plant.
Add chemicals in the sequence required by your test plan.
Step 5 - Take Proper Measurements and Record Data
Measure the free chlorine and the residual chlorine. Record the data. Determine at what point, or around what point, breakpoint chlorination occurred. Conduct another jar test to narrow down the amount of chlorine that is needed, if necessary.
Q: Here is a question we didn't get a chance to answer last month - How many people are required for confined space jobs?
A: Confined Spaces of the Canada Occupational Health and Safety Regulations (COHSR) sets out the confined space requirements for federally-regulated workplaces such as many First Nations water treatment plants. The COHSR states that the employer shall, where a person is about to enter a confined space, appoint a qualified person to conduct the assessments to ensure the hazards are identified and ensure the assessment has been completed and covers the hazards of the specific space. The results of the hazard assessment shall determine how many entrants are required. The COHSR requires the employer to keep two or more persons in the immediate vicinity of the confined space to assist in the event of an accident or other emergency. One of the persons shall be the holder of a basic first aid certificate.
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
This month, Deon Hassler will be answering questions about water treatment plant operator rights and responsibilities.
Deon Hassler, Circuit Rider Trainer, File Hills Qu'Appelle Tribal Council
Q: What are the water treatment plant operators responsible for in the water treatment plant and outside of the water treatment plant?
A: The water plant operators are responsible for operating and maintaining drinking water treatment systems as well as for implementing effective sampling and testing to continuously monitor drinking water quality. They must also keep records to fully document maintenance, activities, monitoring, and corrective action. [Protocol for Centralized Drinking Water Systems in First Nations (PCDWSFN), Appendix A: 1:2]. (Water and Wastewater Operator Certification Program Guide; Appendix B-1 & B-2, Typical Duties).
Q: What records do the water treatment plant operators need to keep in the water treatment plant?
A: The water system operator must keep an up-to-date register in which the dates and results of all required operational sampling and testing (as outlined in Section 3.4 of the PCDWSFN) are recorded along with the name of the person who conducted the sampling and testing. The data collected for registers must be kept for a minimum of five years. In addition, water system managers must keep all records related to water quality monitoring, operations, and system maintenance [including laboratory analyses, ACRS (Asset Condition Reporting System) reports, annual reports, and consultant reports] for a period of not less than five years. The water system operator's daily and weekly record-keeping will include Log Book of Daily Plant Checks. (PCDWSFN; 1. Operational Monitoring, 2. Quality Control, 3. Compliance & Third-Party Monitoring, 4.2 Record Keeping).
Q: Can operators refuse to enter confined spaces?
A: Yes, operators can refuse to enter confined spaces until all issues have been resolved according to the standards. Proper confined space procedures need to be followed. Warnings must be prominently placed in any hazard zones. Barricades should be set to prevent unauthorized entry.
In general, all workers in Canada have three fundamental rights:
The right to know what hazards are present in the workplace, and be given the information, training, and supervision you need to protect yourself.
The right to participate in keeping your workplace healthy and safe, which may include selecting or being a health and safety representative or committee member. You also have a right to report unsafe conditions and practices.
The right to refuse work that you believe to be dangerous to yourself or your co-workers. When you exercise your right to refuse work, you must follow the proper procedure.
Q: In Saskatchewan, how many Continuing Education Unit (CEU) credits do water treatment plant operators need to renew their certification?
A: In Saskatchewan, to renew a certificate, an Operator needs to obtain no less than 1.0 Continuing Education Units (CEU) during the two year renewal period. 1.0 CEU is earned by completing 10 hours of training courses approved by the Operator Certification Board (OCB).
Deon is eager to answer more of your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
We are launching the First Nations and Rural Water Operator Forum!
Meet Deon Hassler - Feel free to ask him questions!
Deon Hassler
Deon Hassler has worked for the File Hills Qu’Appelle Tribal Council for five years. He has worked in water treatment and wastewater treatment for over ten years. Deon is responsible to 11 First Nations bands in terms of technical services to mentor, train, and assist the water treatment operators in operating and maintaining their systems, and obtaining and maintaining certifications.
Some people have already asked questions!
Q: What is TDS?
A: TDS is short for Total Dissolved Solids. In Canada, and the rest of the world, the guideline/regulation/standard is 500 mg/L. However, in Saskatchewan the province has set the TDS limit to 1500 mg/L. Such a high TDS limit will make the water taste salty and it is extremely harsh on any appliances that use water. The life of such appliances will typically decrease by 50%.
Q: What are THMs?
A: THMs is short for trihalomethanes. THMs can cause cancer. They are formed by free chlorine reacting with dissolved organic carbon (DOC). Originally, the guideline for THMs in Canada was 350 ug/L but, in 2006, it was decreased to 100 ug/L. This is especially important for water treatment plants treating surface water.
Q: What is DOC?
A: DOC is short for Dissolved Organic Carbon. When you make tea or coffee you are producing DOC. In the natural environment, DOC is formed from decaying vegetation and, if there are high enough levels, the water can take on a yellowish/brownish tint. There are no guidelines/regulations for DOC but if you want the water to meet the Canadian guideline for THMs (100 ug/L) then you need to make sure the water contains less than 5 mg/L of DOC before treating the water with chlorine.
Q: The water in my community smells really bad and tastes even worse, is it still safe to drink?
A: Will anybody in the community drink the water? Most likely not many. However, it is possible that it is still safe to drink. It is funny, but neither federal nor provincial water agencies in Canada have tested tap water for smell and taste, they only test for safety. So, if this community is a First Nations community, then Health Canada has likely tested the water and made sure that it is safe.
Q: How much chlorine do you need to add to the treated water?
A: That depends, you need to have a free chlorine residual of 0.20 mg/L at the end of the distribution system. Therefore, if you are using a treatment system like the Integrated Biological and Reverse Osmosis Membrane (IBROM) process where there are no chlorine consuming substances, 0.30 mg/L of chlorine is added at the treatment plant. If, however, you have ammonium and dissolved organics in your treated water you need to take into account how much free chlorine will be converted to total chlorine by the time the water has reached the end of the distribution system.
Q: How much chlorine do you need to add to the treated water?
A: That depends, you need to have a free chlorine residual of 0.20 mg/L at the end of the distribution system. Therefore, if you are using a treatment system like the Integrated Biological and Reverse Osmosis Membrane (IBROM) process where there are no chlorine consuming substances, 0.30 mg/L of chlorine is added at the treatment plant. If, however, you have ammonium and dissolved organics in your treated water you need to take into account how much free chlorine will be converted to total chlorine by the time the water has reached the end of the distribution system.
Q: Doesn't chlorine smell and taste bad?
A: If large quantities of chlorine are added, then it sure does! However, at low levels like those needed to be added to water that has been treated by the IBROM process (0.30 mg/L of free chlorine) there is no smell or taste of chlorine.
Deon is eager to answer your questions. So, feel free to hassle the Hassler! Send an email message to safedrinkingwaterteam@gmail.com with any and all questions you have regarding drinking water treatment!
It Is With Heavy Hearts that We Inform You of the Passing of Dr. Hans Peterson
It is with heavy hearts that we write to inform you of the passing of Dr. Hans Peterson on October 24, 2018.
Hans devoted his life to trying to make safe drinking water available to every Canadian.
Following his retirement, Hans founded the Safe Drinking Water Team (SDWT). He was an SDWT Scientific Advisor and, as most of you likely know, he worked tirelessly to try to get safe drinking water to rural and First Nations communities.
SDWT’s focus is on providing water treatment operators with training, which enables them to earn Continuing Education Units (CEUs) to keep their certification. SDWT focuses on rural and First Nations water treatment plant operators so they can help each other to resolve water treatment issues as well as by commenting on political issues involving drinking water.
Hans’ email signature included the following quote, “For many of us, clean water is so plentiful and readily available that we rarely, if ever, pause to consider what life would be like without it.” - Marcus Samuelsson
Quotes from Dr. Hans Peterson:
“Then one day I was back in Saskatoon and was biking on the dirt trails along the river when I started to count the number of people who now have safe drinking water due to our work, more than 100,000.”
“I began to think about drinking water treatment again, I started to dream about a world that had abandoned expensive and ineffective chemical treatment processes in favour of inexpensive and effective biological treatment.”
“Any raw water source is a smorgasbord for bacteria. As long as we supply ice cream, steak, French fries and Greek salads to the bacteria we will continue to fail to produce safe drinking water even if we meet every regulation in the book.”
In lieu of flowers, the family has requested donations be made to Safe Drinking Water Foundation (SDWF). Hans was one of the original founders of SDWF.
Please visit https://www.safewater.org/donate/ to make a donation online or mail a cheque payable to Safe Drinking Water Foundation to #1-912 Idylwyld Drive North, Saskatoon, SK S7L 0Z6.
The 3 Most Notable Observations and Conclusions Gained from Applying a Scientific Approach to the Treatment of Bad Source Water for Rural Communities
Applying a scientific approach to the treatment of bad source water for rural communities on the prairies leads to several observations and conclusions. Below are a few of the more notable ones:
1) Larger cities have relatively good quality raw water sources. These raw water sources contain manageable amounts of contaminants, including chemicals. These cities use chemicals to treat their raw water.
2) Smaller communities across the prairies generally depend on very poor quality raw sources. These sources contain higher levels of contaminants including metals, organic compounds, other trace elements, and chemicals. Given these conditions, it is simply not possible to treat the water with a “big city approach”. Adding chemicals to treat drinking water is disastrous when the water already contains high levels of chemicals.
Do not hesitate to contact us at safedrinkingwaterteam@gmail.com if you have any comments or questions regarding this article.
Have a Wonderful Fall,
Safe Drinking Water Team
Important Questions for Prime Minister Justin Trudeau
Dear Right Honourable Justin Trudeau,
Thank you for having one of your employees respond to my e-mail message. While it was, more or less, the expected response (if I was lucky enough to receive one), it was still good to know that someone in the government saw my e-mail message.
It was a good example of your government’s and Indigenous Services Canada (ISC)’s lack of understanding of the issues facing First Nations communities. For decades, government agencies have provided advice for First Nations communities across Canada. The way that ISC (which, at other points in time, had various other names and acronyms) provides advice is by encouraging (or forcing) First Nations communities to go with the Lowest Cost Bid. Therefore, what First Nations communities have are simply the cheapest, poorest water treatment systems of any rural community. The bottom line is always simply the price, not how well the system works.
Cheap equipment and processes that do not work are in hundreds of First Nations communities. How do we correct this? I am trying to do everything I can by writing to you, but I fear that at best I will receive another letter that again shows little understanding of the real issues.
I know that you saw and listened to Autumn Peltier, a twelve-year-old girl who is doing everything in her power to help First Nations communities have access to safe drinking water, when she gave you gifts during a ceremony in Gatineau, Quebec on December 6, 2016. Here is a picture of that moment:
She was crying as she said to you, “I’m very unhappy with the choices you’ve made.” Your response to her was, “I understand that.”
As part of your election platform, you pledged to eradicate all drinking water advisories in First Nations communities by March 2021. However, now we read articles in the news about funding gaps on the First Nations water promise, the fact that the Indigenous water crisis isn’t improving, and that the government’s work on First Nations drinking water advisories falls short. While 67 long-term drinking water advisories have been lifted on public systems since November 2015, 35 have been added.
Have you seen the graph on ISC’s website predicting the progress on lifting long-term drinking water advisories on public systems on reserve? As you can see, here, it is unrealistic:
If you look at the graph from 2016 until the present date, you will see that out of the 13 data points four of them (31%, almost one-third) are higher than the data point before it. Suddenly, from now until 2021 there will be no increases? Could you please explain what has changed?
From 2016 until present, there was a net decrease of 32 long-term drinking water advisories. This was a period of approximately two and a half years. However, in the next two and a half years you think that the number of long-term drinking water advisories can go from 73 to 0, a net decrease of 73? Again, what has changed? Maybe I have figured out your plan to achieve the unrealistic results in your graph – I think that plan is called “Adding Massive Amounts of Bleach to Water in First Nations Communities”.
Also, it is very important that the government’s goal not just be to get to zero long-term boil water advisories, but to make sure that the boil water advisories do not reappear a year or two later. Therefore, the proper solutions as well as excellent, ongoing water plant operator training, and a decent rate of pay for the water plant operators, must be in place.
If your promise does go unfulfilled in 2021, what are you going to say to a then 17-year-old Autumn Peltier? Are you going to tell her, again, how you understand that she’s very unhappy with the choices you made?
What will get the long-term drinking water advisories number to 0 by March 2021? Forming a Truth and Reconciliation Committee? Alternatively, more simply, ditching the Lowest Cost Bid and implementing water treatment processes that actually work for First Nations communities?
Wow, would that not be a novel idea? In Saskatchewan, we actually have a water treatment process that works on the worst source water imaginable, and its development was actually spearheaded by two Indigenous and Northern Affairs Canada (INAC) employees, Jouko Kurkiniemi and Earl Kreutzer, both unfortunately now retired. It was named the Integrated Biological and Reverse Osmosis Membrane (IBROM) treatment process. It was developed on our poor quality source waters (both ground water and surface water designated by INAC as untreatable), it is based on science, it was developed between 2002 and 2004 at Yellow Quill First Nation, and since then another 22 communities have adopted it. It works flawlessly and is producing superior quality treated water that meets all global standards, regulations, and guidelines. The treated water also meets the World Health Organization’s guidelines for calcium and magnesium, ending up with a treated water that is safe, healthy, and good tasting. It has been presented at the United Nations in New York as the Indigenous Environmental Network (IEN) of the United States considered the development of the IBROM the most significant water development in Indigenous communities globally.
There are currently seven IBROM water treatment plants in communities within the Saskatoon Tribal Council (STC) area. In 2018 all of the water treatment plants in communities within the STC area will be replaced by IBROM water treatment plants. These IBROM plants will replace INAC’s standard treatment: manganese greensand, a 100-year-old technology that nobody uses. Well, except INAC/ISC. The Environmental Health Officer (EHO) for STC stated, “When a community gets an IBROM my work is done.”
Why is the federal government not focusing on implementing water treatment systems which are proven to work, which are known to be effective on the worst source water in the country?
To us, safe, healthy, and good tasting tap water is a basic human right.
The Guidelines for Canadian Drinking Water Quality outline the minimum acceptable quality of water to be distributed to consumers’ taps in Canada. Health Canada’s Water Quality and Health Bureau plays a leadership role in science and research when it comes to the guidelines and Health Canada has published the Guidelines for Canadian Drinking Water Quality and the Guideline Technical Documents (formerly known as Guideline Supporting Documents) since 1968.
It is interesting to note that it is the Federal-Provincial-Territorial Committee on Drinking Water that actually develops the Guidelines for Canadian Drinking Water Quality. This committee meets twice per year and is composed of voting and non-voting members. There are 14 voting members, one for each jurisdiction in Canada (10 provinces, three territories, and the federal government). Each of these members represents the authority responsible for drinking water quality in their jurisdiction, usually one of either the department of health or the department responsible for the environment. Non-voting members include representatives from the Committee on Health and the Environment, Environment Canada, and the Canadian Advisory Council on Plumbing.
This creates an odd dynamic. Health Canada’s researchers are trying to put together guidance that is technically solid, but the provincial representatives have different objectives. They try to figure out if what Health Canada wants to implement is possible or practical in their own provinces. Most of the time the provincial representatives vote against Health Canada.
Since there are 13 provincial and territorial votes and Health Canada only has one vote, it is next to impossible for Health Canada’s technical position to win. However, every province and territory in Canada subscribes to this equation. As an example, Health Canada suggested that the guideline for the maximum amount of arsenic be reduced from 25 ug/L to 5 ug/L in 2006. The provincial and territorial delegates agreed to lower the arsenic guideline to 10 ug/L. Even then, some provinces failed to endorse Health Canada’s Guideline. Ontario’s drinking water standard for arsenic was actually held at 25 ug/L until January 1, 2018, when it was finally lowered to the 10 ug/L guideline. This is a large reduction as, not that long ago, the arsenic guideline sat at 50 ug/L. A review of published literature led Kapaj, Peterson, Liber, and Bhattacharya (2006) in their paper "Human Health Effects From Chronic Arsenic Poisoning - A Review" published in Journal of Environmental Science and Health to recommend that communities with arsenic levels higher than 5 ug/L in their drinking water supply should have community members tested for arsenic poisoning.
Some people considered Dr. Kapaj’s guidance as too “extreme”. At the same time, Health Canada wrote that human health effects could be expected at levels as low as 0.3 ug/L of arsenic. The question then is why would setting the Canadian guideline for arsenic at over sixteen times higher be too “extreme”? Would a maximum acceptable level of 0.3 ug/L not be more appropriate? Granted, stand-alone technologies like manganese greensand and even direct RO will fail to produce such low arsenic levels when treating anaerobic arsenic-tainted groundwater having these problems.
There are many similar examples, leading us to argue that the Guidelines for Canadian Drinking Water Quality is a document that is compromised by provincial politics and conflicting objectives. Moreover, while some don’t see this coming, we need to ask ourselves: “Where is the input from First Nations?” Would First Nations subscribe to politics rather than health?
Maybe not. However, as First Nations are not represented on the Federal-Provincial-Territorial Committee on Drinking Water how do we find out? What if First Nations develop their own water quality regulations with a different objective: to promote health in First Nations communities?
There is one source that First Nations could use to move such regulations forward: Health Canada’s own statements. What if First Nations embrace Health Canada’s health-based recommendations and ignore the politically influenced guidelines set by the Federal-Provincial-Territorial Committee on Drinking Water?
It would clearly set a major precedent, perhaps to the point of over-throwing the current regulatory governance framework. Why are First Nations not included in the committee that sets the Guidelines for Canadian Drinking Water Quality? These guidelines affect them, so should they not have a say?
Open Letter to The Right Honourable Justin P. J. Trudeau, Prime Minister of Canada
Robert Pratt Vice President, Safe Drinking Water Team May 8, 2018
Justin Trudeau House of Commons Ottawa, ON K1A 0A6
Dear Prime Minister Trudeau,
Much has been said by you and reiterated by the national press regarding one of your election promises: the elimination of boil water advisories by March 2021. The press has frequently repeated your promises. The only discussion that seems to be entertained is whether this is feasible. However, I believe there is a much bigger question at play: “Is it the right thing to do?” I think not. Let me explain.
The federal government’s Indigenous Services Canada (ISC) has embraced your battle cry with gusto. Unfortunately, they are focused on managing the very visible metric of the number of outstanding long-term boil water advisories rather than the root cause of the problem. This is leading to short cut solutions such as pouring more chlorine into treated water or adding whatever piece of equipment that can kill E. coli and total coliforms, the causes of the majority of boil water advisories issued by Health Canada. The national press is led to believe that water treatment problems are being resolved, but are they actually being resolved?
The single biggest issue that I would like to highlight is the increasing use of temporary approaches to end boil water advisories as your government puts pressure on ISC to meet an election promise. It does a fundamental disservice to these communities and it wastes money. These plants will quickly fail again and there will be more boil water advisories. What is worse is that lifting a boil water advisory does not mean that the tap water is safe, healthy, and good tasting. I believe this should be the goal for distributed water in First Nations communities, actually, in all communities across Canada.
Small First Nations communities must deal with horrible raw water quality and antiquated water treatment processes and equipment. This only serves to promote bottled water sales. This is what your government is encouraging. Many community members do not even have the means to obtain bottled water, and their health is at risk.
Short-term band-aids have replaced ISC’s implementation of longer term, sustainable solutions for the most vulnerable people in Canada, Canada’s First Nations. It is embarrassing. Will you take the necessary steps to reframe the original election promise? A renewed promise should put a more realistic timeline on the objective. The promise should also be framed to promote sustainable, long-term fixes that address evolving drinking water guidelines that will move Canada towards internationally recognized standards. Let us do the right thing and fix this issue community by community. Oh, and let us stop wasting taxpayer dollars and rewarding ISC for managing a single, very visible metric.
Political leaders frequently make decisions regarding water treatment processes for their communities. Others involved with this can be managers of project teams. All involved know one thing: water is wet. However, moving from this basic fact, their knowledge is variable and sometimes limited. And, why not? These people are not water professionals that have made it their career to understand water treatment processes.
Looking at what is available to treat water, the selection can be bewildering even for a water treatment professional. Therefore, it is not surprising that political leaders stumble when they try to select a water treatment process. To help them out, I am trying to summarize the basic concepts that most water treatment processes employ.
We have ground water and surface water, which offer somewhat different problems and somewhat different solutions. My discussion will include both. Two fundamentally different strategies are being employed. There are processes where a raw water is treated in various ways and close to 100% of the water is then sent out for consumption. This is how water treatment used to be for more than a hundred years. Another name for this is conventional treatment and it is employed by most cities, such as Buffalo Pound Water Treatment Plant (serving Regina and Moose Jaw) and Saskatoon. The second strategy is where technologies employing osmosis will split the water into a concentrate (waste) stream and a product stream that we can drink.
First, I will discuss the technologies where all the water is distributed. These technologies often employ two steps. The first step can rely on the addition of a chemical that will bunch smaller particles together to make them bigger (coagulation), to make them easier to be removed, or an oxidation chemical, such as permanganate, in the manganese greensand process. Oxidation processes are often used to change the chemical state of iron, manganese, and arsenic in ground water sources, facilitating removal.
Filtration steps can be granular (various forms of sand filtration, granular activated carbon, and manganese greensand) or water can be pushed through cartridge filters of different kinds (micro- and ultra-filtration). Cartridge filters have “holes” that will let water through. Both granular and cartridge filtration have one thing in common, close to 100% of the treated water is distributed. Therefore, what we can do is coagulate, adsorb, oxidize, and filter.
Where many of the above treatment processes fail, however, is in the removal of dissolved organics. These organics are composed of fat-loving (lipophilic) and water-loving (hydrophilic) compounds. Globally, we can assume that these compounds are present in equal quantities. Therefore, we have water that has 50% fat-loving organics and 50% water-loving organics. This is very important. Coagulation can only pull out fat-loving compounds.
Therefore, for example, when an engineering company does a pilot process on a 24 mg/L dissolved organics water it really does not matter how much coagulant is added, the removal will stop at 12 mg/L. No matter how much coagulant is added, only 50% of the organics will be removed. If a community has demanded that 2 mg/L be reached it simply will not happen. This points to something that is lacking in water treatment, the use of science to make sure a water treatment process works. Dissolved organics are not a concern by themselves, but they are pre-cursors to chlorination by-products that can be carcinogenic. To meet future regulations 2 mg/L of dissolved organics or less will be required.
Chlorination is required in many countries as a final water treatment step. During chlorination, water becomes bleached and although its quality for drinking may have deteriorated, its aesthetics have improved.
Chlorinating (bleaching) a cup of tea (left)
What is left in the water when chlorine is added can be a concern for government officials. What are the reasons you may ask? First, the above processes typically leave at least 50% of the dissolved organic material behind in the water (remember my comments about fat- and water-loving organics). These organics react with chlorine to form chlorination by-products, such as Trihalomethanes (THMs) and halo-acetic acids (HAAs), for which many countries have regulations because they are carcinogens. Secondly, water treatment has, unfortunately, become a numbers game where the main concern is meeting regulations. However, we should heed the following comments by the United States National Research Council (1998):
Current drinking water quality standards are aimed at water obtained from relatively uncontaminated sources and, thus, cannot be relied on as the sole standard of safety.
Diverting the action of chlorine towards dissolved organics is detrimental in other ways, too, as it leaves less chlorine to kill microbes. Chlorinated organic compounds are measured by the operator as total chlorine and the operator also measures free chlorine, which kills microbes.
When a water treatment operator notices a difference between the free and total chlorine level in the drinking water he/she knows that the difference is caused by chlorine reacting with mainly organic material. Chlorine also likes ammonium. Therefore, if there is ammonium in the water, chlorine reacts with the ammonium to form chloramines that are 10 to 1,000 times less powerful than free chlorine. This means the microbes in the water will not be killed effectively. However, chloramines are more stable than chlorine, so their use is approved if at first free chlorination has been practised (primary disinfection) with enough contact time, after which ammonium can be added to form chloramines. This is termed secondary disinfection. Health Canada states that no community in Canada should use secondary disinfection alone. Secondary disinfection is only acceptable if primary disinfection has been used first.
Whatever microbes, organics, and chemicals remain in the water will be exposed to chlorine. Chlorine kills microbes and what we actually drink is free chlorine, chlorinated organics, and dead microbes. That is, if we are lucky. Chlorine cannot kill some microbes, such as the human parasite Cryptosporidium. Therefore, a water operator’s only chance to deal with Cryptosporidium is before the chlorination step. This is very difficult to achieve with granular filtration, a water treatment process that close to 100% of conventional water treatment plants employ.
During the past several decades technologies have been developed that are based on osmosis. These technologies have become commercially available. In the water industry the main technology used is Reverse Osmosis (RO) and Nano-filtration (NF). Contrary to the technologies described above, both of these technologies split the water in two. A concentrate or waste stream and a product stream that will be distributed.
Saddle Lake RO concentrate water/stream (left) and product water (right). No chemicals have been added to either bucket.
To visualize how osmosis works, think of a sealed envelope that sits in water. We then apply pressure to the water and pure water migrates into the envelope while dirty water stays on the “concentrate side” or “waste side”, it remains outside the envelope. Nano membranes often provide water with a Total Dissolved Solids (TDS) content below most drinking water guidelines of 500 mg/L. The TDS level of RO treated water can be ten to twenty times lower than this. While Nano membranes may produce water with a pH of just below 7.0, that of RO water can be below 6.0. This seems to be two strikes against RO, in favour of NF, but closer examination may show something different. Both membranes remove calcium and magnesium and the higher TDS with a Nano membrane is mainly composed of ions that we do not want in distributed water.
The concentrate stream typically ranges from 10% to 25% of the amount of the raw water. At 10%, this means that 9 L of product water will be produced and 1 L of wastewater will be produced. This has been viewed as a negative for both technologies. However, moving microbes, organics, and indeed ions out from the treated water has many advantages. When this water is chlorinated it does not encounter any of the problems with which old technologies struggle. There are no chlorination by-products because all of the organics have been removed. All of the microbes have virtually been eliminated. The quality of the treated water has been much improved. Every guideline/regulation can be met with ease. Indeed, many compounds are 10 to 100 times lower than guidelines/regulations require. Many contaminants like heterotrophic bacteria, disinfection by-products, and arsenic can be below detection levels. This is great, as some of these guidelines are decreased from time to time. Tight membrane technologies are prepared for this, whereas most conventional treatment processes are not. As most water treatment plants are expected to last at least 20-30 years, using technologies that can meet guidelines for the same time periods has the advantage that “meeting guidelines” does not become an issue every time the guidelines change.
Some see the RO split of water into product and waste as a negative. I do not understand that, and I believe that this is the most positive development in water treatment in the past 100 years. Not making us drink a virtual graveyard of microbes and carcinogenic organics is nothing but a huge upside, in my opinion. What to do with the concentrate stream from an RO can of course be a challenge, but a challenge well worth taking.
The real crux of the problem with using RO membranes on most water sources is membrane scaling and fouling. Scaling is the precipitation of inorganic ions on the concentrate side of the membrane. This causes decreases in the transfer of pure water to the product side. Membrane fouling can be a combination of scaling, fouling (adsorption of organic compounds), and growth of microbes on the concentrate side of the membranes. Attempts to deal with these issues have included the use of anti-scalants, modification of membrane surfaces providing lower “stickiness”, and the addition of chemicals to discourage microbial growth. Mostly, these efforts have shown limited success. Research and development activities on some of the poorest quality water sources on Earth have come up with a surprising solution to this dilemma. Starving bacteria. More about this in a future e-mail message.
Dr. Hans Peterson, Scientific Advisor, Safe Drinking Water Team
