O.Reg. 170/03 and O.Reg. 248/03 were amended with regard to requirements for lead sampling in municipal systems and schools and day nurseries. (Revised)

In 2007, the Ontario government required municipal drinking water systems, schools and day nurseries to undertake mandatory testing for lead in drinking water to ensure lead levels met the Ontario Drinking Water Standards. 

Since that time, the testing undertaken has demonstrated that the vast majority of municipal and non-municipal residential drinking water systems, schools and day nurseries have met the standards. As a result, MOE has recently filed amended regulations under the Safe Drinking Water Act to clarify some of the requirements for testing and to introduce an automatic exemption for municipal drinking water systems serving under 50,000 people. The exemption is available to these systems if:

  • The system is already doing reduced sampling or if the system has been granted sampling relief by the Ministry, AND
  • Not more than ten per cent of plumbing samples over a complete year of sampling (winter and summer) have exceeded the standard
The exemption is automatic once test results have been submitted to the Ministry and MOE approval is not needed. Distribution system samples are still required.

MOE has already alerted drinking water systems owners registered with the Ministry regarding the changes.

For further information, municipal officials are encouraged to contact the Ministry of the Environment’s Public Information Centre at 416-325-4000 or 1-800-565-4923 or by email at picemail.moe@ontario.ca.


Members are encouraged to use contact the Ministry of the Environment for more detailed information regarding the amendments. AMO will continue to keep members informed of developments in water policy and requirements.