Small drinking water system operators are required to immediately report every adverse observation or test result to Public Health that would indicate the system may not be providing safe water to users.
- The immediate notice must be done by speaking in person or by phone with the public health inspector or the after-hours on-call inspector. You cannot leave a voicemail.
In the event that an adverse event or observation requires an order or advisory, the information will be made public on Check Before You Go!
Responding to Adverse Events Factsheet: Ministry of Health (PDF)
You are required, as an owner or operator of a small drinking water system, to provide users with safe drinking water at all times.
When something goes wrong with your drinking water system, the event may be referred to as either an adverse observation or an adverse test result, and specific notification requirements and corrective actions will be required.
The regulation provides the initial directions with regard to the appropriate response, which may include actions such as:
- notifying the users of the drinking water system
- taking necessary steps to correct the problems
- notifying the Medical Officer of Health (MOH)
If your test results indicate your drinking water is unsafe, then you must:
- contact Public Health Sudbury & Districts
- stop using the water supply for drinking unless boiled
- notify all other users to avoid drinking the water and to use an alternative source
- follow the notification requirements listed in the regulation
If you are reporting an adverse water test result or observation to Public Health, you must call and state that you need to speak with a live person as you are mandated to report an adverse water test result or observation. If you are reporting an adverse water test result or observation after-hours, an agent will send a page to the after-hours on-call inspector. A public health inspector will call you back with steps to follow to resolve the problem.
A follow-up written notice within 24 hours must also be sent to the MOH. You can do this by completing the notice of adverse test results and issue resolution (Ministry of Health) form.
Both the immediate report and the 24-hour notice must specify the adverse result or observation, the actions being taken in response, and whether any required corrective action (specified in the regulations) is being taken.
In addition to the above general notification requirements, the small drinking water system regulation also includes corrective actions and notification requirements according to the specific adverse result or observation in question. Some examples are as follows:
Presence of E. coli
- Immediately notify all users of the drinking water system to use an alternate source of drinking water or, if none is available, to bring their water to a rapid, rolling boil for at least one minute before use.
- Immediately notify the Medical Officer of Health (MOH).
- Immediately resample and test. Follow the requirements given to you by a public health inspector.
If your drinking water system uses chlorine, immediately increase the chlorine dose and flush the system to ensure there is adequate chlorine residual.
Maintain the residual until two consecutive water samples taken 24 – 48 hours are free of E. coli.
Presence of total coliforms
- Immediately notify the MOH.
- Resample and test as soon as possible.
If your drinking water system uses chlorine and total coliforms are still detected upon resampling, immediately increase the chlorine dose and flush the system to ensure there is adequate chlorine residual. Maintain the residual until two consecutive water samples taken 24 – 48 hours apart are free of total coliforms.
If your SDWS does not use chlorine, immediately follow the steps for temporary disinfection of the system as required by the MOH (consistent with the Ministry of Health and Long-Term Care’s Procedure for Corrective Action for Small Drinking Water Systems that are Not Currently Using Chlorine).
Improper disinfection
- Immediately restore the disinfection.
- Immediately notify and instruct all users of the drinking water system to use an alternate source of water or, if none is available, to bring their water to a rapid, rolling boil for at least one minute before use.
- Immediately notify the MOH.
Other adverse events
When an adverse event is not a result of bacterial contamination, you may need to apply different corrective measures than those listed above. Some adverse events may be caused by any of the following:
- Chemical spill that enters the source water that supplies your drinking water system (for example, diesel or other petroleum-based products).
- Agricultural products that enter your drinking water system source either from a run-off or by leaching into the aquifer that supplies your system.
- Broken pipes or water mains that become contaminated.
- Naturally occurring chemicals or radiological agents such as nitrate, lead or uranium.
At such times, you must notify Public Health Sudbury & Districts and follow any steps required by the MOH or public health inspector to resolve the problem.
In addition to the specific regulatory requirements for responding to adverse observations and adverse test results, the Medical Officer of Health or public health inspector may issue additional requirements to correct the problem. These steps are mandatory.
Once you have taken the necessary steps to remedy the problem that caused the adverse test result or observation, you must provide a written notice to the Medical Officer of health summarizing:
- actions that were taken to correct the issue; and
- the results that were achieved.
The written notice must be on the same Notice of Adverse Test Results and Issue of Resolution form advising of the adverse water test result or observation.