Treatment, Testing, Monitoring, and Sampling

To know whether your treatment methods and maintenance practices are effective, you should develop and implement a monitoring program for your small drinking water system. Monitor it routinely to ensure the drinking water provided to users is safe to drink and, where required, is effectively treated.

Steps to include in your monitoring program:

• develop a check sheet
• list all of the items to be monitored, the frequency of monitoring and the sampling location(s), consistent with the directive issued for your small drinking water system
• record the activity
• keep records of all operational activities in accordance with the regulations and any directive issued for your system
• it is important to keep records such as:
  • treatment residuals results, lab test results, equipment maintenance and other operational requirements, including any adverse results or observations and corrective actions taken

The frequency, number and type of samples will be outlined in the directive for the small drinking water system. The directive may also dictate what location(s) you must take water sample(s) from. To begin, you must select a commercial lab that is licensed by the Ministry of the Environment, Conservation and Parks to test for E. coli, total coliforms or any other parameters listed in your directive.

The Ministry of the Environment, Conservation and Parks has a current list of labs licensed to perform tests of drinking water samples, you can also call their public information centre at 1.800.565.4923.

Tips before collecting a drinking water sample:

• Before you collect water samples, contact the lab you’ll be sending your samples to for testing. Follow the sampling instructions provided to you.
• Take the drinking water sample from any tap after the water has entered the distribution or plumbing system. It is preferred that the sample is taken from a cold-water tap commonly used by the public for drinking purposes.
• It is important to work in a clean area and to keep all of the equipment used during sampling clean (for example, the sample bottles, the transport container, the surface where the water bottles will be stored, etc.)
• Attach the label provided by your licensed laboratory to the bottle before taking the sample. On the label, put the date, your drinking water system identification number and the location where the sample will be taken.
• Wash your hands or wear new, clean disposable gloves.

Properly collecting a drinking water sample:

• Remove any aerators, tap screens, hoses, or filters on the tap.
• Use an alcohol swab or bleach and water solution to clean the mouth of the tap before collecting the sample. Do not flame the tap.
• Let the water run until it is cold (2 to 5 minutes) before collecting the sample.
• Use a sterile sampling bottle provided by a licensed laboratory to collect the water. These bacteriological sampling bottles have tamper-proof seals. Don’t use one if the seal has been broken; ask the laboratory for a new one.
• Don’t rinse the sampling bottle before using, or you will remove some or all of its preservative and ruin the sample.
• Don’t touch the inside or lip of the sampling bottle or its cap, otherwise you may contaminate your sample. For the same reason do not place the bottle cap face down on any surface while filling the bottle with the sample. The inside of the cap and container should only come into contact with the air and the collected sample of drinking water.
• Fill the sample bottle to the fill line. Adjust the tap flow rate to prevent splashing. Fill the bottle up to the fill line, leaving an air space. Do not allow the water to overflow. The air space is needed to conduct the test in the laboratory.
• Cap the bottle immediately after collecting the sample. Put the cap on tightly to prevent leakage. Remember not to touch the inside of the cap or the mouth of the bottle with your hands!

How to store your drinking water sample and send it to the laboratory

• Submit your drinking water test sample to the licensed laboratory as quickly as possible after collection, preferably within 24 hours. To give the most accurate results, testing for bacteria must begin within 24 hours of collecting the drinking water sample. Be sure to obtain clear instructions from the laboratory regarding sample submission drop-off time.
• Refrigerate samples until ready for shipping. It is best to keep the sample between 4-10°C. Do not allow samples to freeze.
• Ship your sample bottles or containers to the laboratory in coolers, or in foam pack containers, with ice bags or ice packs. Do not pack the bottles in loose ice, as this may contaminate the sample. If you only have loose ice, encase the sample/container in waterproof packaging or a sealed container.
• Ensure the laboratory’s Chain of Custody form (provided by the laboratory) is completed in full and send it to the laboratory along with the collected sample. If sending it inside the cooler containing the sample, ensure that the form is enclosed inside a waterproof package (for example, a new resealable plastic bag).

Understanding drinking water test results

The lab report will provide you with two test results, one for E. coli and the other for total coliforms present in your drinking water supply. Total coliforms exist naturally in animal waste, soil, and vegetation. The presence of these bacteria in your supply may suggest that surface water is seeping into your well or for surface water supplies that your treatment is no longer working. E. coli bacteria are found in human and animal digestive systems. Their presence may suggest your water supply is contaminated by manure or sewage from a local septic system or feedlot.

The presence of these bacteria in your water can be dangerous to one’s health.

Recording your samples and test results

• For non-adverse test results, the licensed laboratory is required to send you a report on the test of your drinking water sample within 28 days of the lab validating the results. These lab reports must be kept on file and available for viewing at any time.
• For adverse test results, the laboratory is required to report the results to you and to Public Health Sudbury & Districts immediately after the results are obtained. This will allow you to take the necessary action to address the issue that caused the adverse condition. In addition, the lab will fax the Notification of Adverse Test Results and Issue Resolution form to the appropriate contact at the small drinking water system and to Public Health Sudbury & Districts.

An adverse water result must be reported to the Medical Officer of Health immediately using the notification of adverse test results and issue resolution form. Your public health inspector will work with you to ensure that the public is kept safe.

A public health inspector will conduct a site-specific risk assessment of your small drinking water system and will list requirements to monitor, sample and test your system in a directive.

Testing requirements depend on several factors, such as:

• the source and quality of the water supply to your system
• the type of treatment methods used in your system:
  • you may be required to test daily or several times per week to ensure the drinking water is adequately treated
  • you may be required to collect samples from several locations in the distribution system depending on the size of the system
• the presence of chemical, physical or radionuclide parameters:
  • you may be required to test your drinking water for the presence of chemical (nitrate or lead), physical (turbidity) or radionuclide (uranium) parameters in specific circumstances

Protect the source(s) of drinking water from contamination and overuse to support the provision of safe, clean drinking water.

Preventing drinking water contamination at the source can be accomplished by identifying contaminants of concern and reducing or eliminating them. Potential sources of contamination include:

• rainfall and snow melt
• ground slope towards well
• natural chemical content in soil or rock
• wildlife activity
• agricultural runoff
• pets or farm animal activity
• private sewage disposal systems
• chemical spills or releases

Wells must be a safe distance from pollution sources, have a water-tight casing and be protected overall from contaminants

Preventing drinking water contamination at the source can be accomplished by identifying contaminants of concern and reducing or eliminating them. Water can become contaminated with: biological organisms, such as bacteria, parasites and viruses chemical agents, such as nitrates and lead toxins created by algae in surface water

Types of source water

Secure ground water systems

A secure ground water system is a well system that is designed and maintained in accordance with Regulation 903 – Wells under the Ontario Water Resources Act. Important considerations are that the well is a safe distance from any pollution source, has a water-tight casing to over 6 metres in depth and is otherwise protected from surface water contamination.

A secure groundwater system without treatment may be capable of providing safe water. If no treatment is provided, ensuring the safety of the water is limited to source water protection and routine surveillance activities.

Some tips to prevent contamination of your secure ground water supply:

• Ensure that the well is constructed and maintained in such a way to prevent possible contaminants from entering the well.
• Ensure that potential sources of contamination (for example, septic systems, manure storage or chemical usage) are kept safely away from the well.
• Conduct additional sampling and testing if there is a possible threat to the quality of the well water.

Non-secure ground water systems

A non-secure groundwater system is a well or other groundwater collection system that is not a safe distance from pollution sources or is not designed or constructed to prevent contamination by surface water.

If you get your drinking water from a well, contaminants may enter through cracks in the casing, poorly fitted lids or other structural faults. Private wells can become contaminated with bacteria, nitrates or other chemicals if they are close to sources of pollution.

A non-secure groundwater source will require disinfection, at a minimum, to be used for drinking water. This type of water supply has a greater potential for becoming contaminated. The treatment equipment must be checked and maintained to ensure proper operation.

Some tips to prevent contamination of non-secure ground water supply:

• Ensure that the well is constructed and maintained in a manner that prevents contamination that would require filtration.
• Ensure that the well is protected from any potential source of contamination (for example, septic systems, manure storage or chemical use).
• Ensure that the treatment system is always operating so the water is safe.
• Conduct additional sampling and testing where there is a possible threat to the quality of the well water.
• Maintain a level of surveillance of the source water, surrounding area and treatment system suitable to the complexity of the system by scheduling frequent sampling, testing and routine maintenance checks.

Surface water systems

A surface water system is any system that draws water from surface water or a system that may be contaminated by surface water.

Surface water sources are unsafe for drinking, unless the water is filtered and treated to destroy harmful micro-organisms. A surface water system (which may also include a groundwater system that is contaminated by surface water) requires both filtration to physically remove microbes that are not killed by disinfection and disinfection to kill bacteria and viruses.

Some tips to prevent contamination of a surface water supply:

Maintain a level of surveillance of the source water, surrounding area and treatment system suitable to the complexity of the system by scheduling frequent sampling, testing and routine maintenance checks.

Ensure that the treatment system is capable of providing the level of treatment necessary to properly remove micro-organisms and disinfect water.

Ensure that potential contamination that could overburden the treatment system does not enter the drinking water intake.

Ensure that the treatment system is always operating so that the water is safe.

Conduct additional sampling and testing if there is a possible threat to the quality of the well water.

In Ontario, most small drinking water system operators get their water from two sources: groundwater or surface water. The type and quality of source water used, and the design of your system, usually determines the treatment required.

Secure groundwater

Treatment may not be required for water that is obtained from a secure, well-constructed and maintained groundwater source, such as a drilled well.

Non-secure groundwater

Treatment is required if the source water supplying your small drinking water system is a non-secure groundwater source. If the construction or design of your well allows contamination by surface water, then you may be required to provide filtration and disinfection to the well water.

Surface water

Treatment must be provided if the source water supplying your small drinking water system is from a surface water source. For surface water, you will be required to provide mechanical or chemical-assisted filtration and primary disinfection.

If your system has a distribution system, you may be required to provide secondary disinfection.

There are two types of drinking water treatment devices available: disinfecting devices that are used to deactivate or remove harmful micro-organisms, and water conditioning devices that are used to control or remove chemical, taste and odour problems.

Before you choose a device, it is important to have your water tested and speak with a water treatment specialist. You can also speak with a public health inspector from Public Health Sudbury & Districts by phoning 705.522.9200 or calling toll-free at 1.866.522.9200. Look for a device that has been certified by an accredited body. They provide standards that have been designed to safeguard drinking water by helping to ensure the material safety and performance of products that come into contact with drinking water.

The two main processes used in treating your small drinking water system supply are filtration and disinfection.

Filtration

• This process uses a filter to remove particles and reduce the number of parasites from the source water. Filtration is required for all surface water systems and for non-secure groundwater systems that are vulnerable to surface water contamination.
• Filtration is the simplest method for removing suspended particles and turbidity from a drinking water supply to allow for successful disinfection. Filtration methods include slow and rapid sand filtration, diatomaceous earth filtration, direct filtration, membrane filtration and cartridge filtration.

Disinfection

• This process reduces or eliminates the number of harmful micro-organisms in water. Disinfection is required for all surface water systems and for non-secure groundwater systems that are vulnerable to surface water contamination.
• Disinfection can be achieved with chemical or physical disinfectants such as chlorine, chlorine dioxide, ozone and ultraviolet (UV) light. The most common disinfectants used to treat water for small drinking water systems are chlorine and UV light.

Depending on where the treatment is installed in your small drinking water system, it may be considered a point-of-entry treatment system or a point-of-use treatment system.

Point-of-entry treatment system

• This device is installed where the water enters the building. All water used within the building will be treated, including water used for bathing and laundry.
• Point-of-entry systems tend to be larger and more expensive than alternative systems.

Point-of-use treatment system

• This device is installed at the tap where the water is being used for drinking or cooking. Only water used from this tap is treated.
• Water from all other taps will be untreated and should not be used for drinking purposes.

Ultraviolet (UV) Light

• Ultraviolet treatment is the disinfection process of passing water by a UV light source. The UV light is immersed in the water in a protective transparent sleeve and emits UV radiation that destroy harmful micro-organisms. UV devices are required to have an alarm or automatic shut-off to alert when there is a failure.
• The UV device works by emitting similar UV radiation to the sun. This radiation alters the genetic material of viruses, bacteria, moulds or parasites so they cannot reproduce and are considered inactivated. UV treatment does not remove dirt particles, metals such as lead or iron, or hard minerals such as calcium. Other devices are required to remove particles, metals and minerals.
• UV devices are not effective at treating water that is highly contaminated, heavily cloudy or turbid, or high in iron. To increase the effectiveness of the UV device, the water may have to be pre-treated.
• UV lamps should be checked and cleaned periodically, or replaced when necessary in accordance with the manufacturer’s instructions.

Chlorinators

• Chlorination devices provide disinfection to a system by continuously adding a chlorinated product to all water that is drawn from the system.
• Treatment is provided by thoroughly mixing all water in the system with a specific amount (concentration) of chlorine for a sufficient (contact) time period.
• The time that is required for disinfection depends on the concentration of the chlorine solution, the quality of the water entering the system, the pH and temperature of the water and the discharge rate of the pump.
• Frequent monitoring of the water chemistry is necessary to ensure that adequate disinfection is being continuously provided.
• Chlorine provides a disinfection residual, continuous disinfection and allows for easy monitoring.

Ozonators

• These devices use ozone to inactivate micro-organisms and provide some residual protection.
• The device is sealed and requires moderate amounts of electricity to produce ozone.
• These devices are easy to install and maintain, but can be expensive.

The appearance, taste and smell of drinking water are usually more obvious to the consumer than the bacterial quality. Chemicals such as iron, manganese, sulphide and calcium hardness can cause odour and taste problems.

There are several devices available to remedy these problems; however, these units deal mainly with poor odour and taste problems and do not provide disinfection. If not used correctly, they may even increase existing problems with bacterial contamination.

 Activated carbon or charcoal filters

• These devices are used to remove chlorine, odour and taste caused by organic materials. The efficiency of the device depends on the quality of the source water your system uses.
• They are easy to install and require no power to operate. These are not disinfection devices and should only be used on water that is already disinfected and safe to drink.
• If using these devices for water conditioning, you should know that the bacterial levels in your drinking water may increase because of the dirt and organic material that are trapped in the filters.

 Reverse osmosis

• This device conditions your water supply by forcing water through a filtering membrane to remove most microbiological (bacteria, viruses and protozoa) and chemical (metals and mineral salts) parameters.
• It is easy to install and maintain, however the water must be pre-treated to increase the life of the membrane filters that may clog or rupture if the water is of poor quality.

Water softener

• This process is used to remove inorganic contaminants that are inadequately removed by filtration or sedimentation. It is also used to treat hard water and can be used to remove arsenic, chromium, excess fluoride, nitrates, radium and uranium.
• Softened water is not recommended for drinking because increased sodium content can pose health risks if exceeding the upper limit of 20 mg/L.
• This process may use and discharge significant amounts of salt; however, sodium-free softeners are available.

Get advice from a water treatment specialist to choose the best ways to make your drinking water safe.

For the best treatment, buy only devices that have been certified and meet industry standards.