Testing, monitoring and sampling requirements: small drinking water systems

Protect your drinking water by keeping potential contaminants away from your water source.

The Health Protection and Promotion Act – Ontario Regulation 319/08 (Small Drinking Water Systems) requires you, as the owner or operator of a small drinking water system, to provide users with safe drinking water at all times and to know your responsibilities for the type of system you operate.

How to keep your drinking water safe

Protect your drinking water at the source by:

Monitor your drinking water system regularly:

Treat your water with a disinfection system if lab results show unacceptable levels of contamination. This is especially important for surface water sources.

Maintain your drinking water system:

Notify the public if there is a problem with your small drinking water system, whether it is a poor water sample test result or equipment that is not working properly.

Well water may not require treatment if the well is secure and regular samples show acceptable water quality. Consult with professional suppliers to identify and install the appropriate methods for treatment where required.

Testing requirements

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:

Monitoring requirements

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:

Sampling requirements

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:

Properly collecting a drinking water sample:

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

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

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.

This item was last modified on August 27, 2018