Ontario has published several amendments related to drinking water quality standards, lead in schools and day nurseries: drinking water systems; drinking water testing services; and drinking water operator certification. Changes are summarized below

1. changes to Ontario’s Drinking Water Quality Standards will include the introduction of three new drinking water quality standards based on new federal guidelines: 0.06 mg/L for Toluene; 0.14 mg/L for Ethylbenzene; and 0.09 mg/L for Total Xylenes. Two drinking water quality standards will be revised: - from 0.01 mg/L to 0.05 mg/L for Selenium; and from 0.03 mg/L to 0.01 mg/L for Tetrachloroethylene. One drinking water standard, (10 mg/L for Nitrate Nitrite) will be removed. Under changes to the ministry’s Technical Support Document, one new Aesthetic Objective will be introduced: (0.015 mg/L for methyl t-butyl ether [MTBE]); and two Aesthetic Objectives – for ethylbenzene and xylenes will be revised.
2. changes will be made to: lead sampling requirements; flushing requirements for fountains and taps; using filters or other devices for lead removal; changes to reduced lead sampling; and corrective action.
3. All pesticides found at levels above 100 nanograms/Litre (ng/L) will initiate an Adverse Water Quality Incident (or AWQI). All test results that indicate the presence of pesticides – even if their concentration levels are at or below the threshold of 100 ng/L – will need to be provided to the ministry.
4.  laboratories, among other things, will need to submit drinking water test results to the ministry more quickly, within ten days (reduced from current 28 days).
5. requirements for Drinking Water Operator-in-Training (OIT) Certification have been updated.