Backgrounder: City of Toronto’s Lead Mitigation Strategy
April 3, 2018
Regulated lead testing program
- In 2007, the Ontario Ministry of Environment and Climate Change (MOECC), under the Safe Drinking Water Act, implemented a Regulated Lead Testing Program for Ontario municipalities where fewer than 10 per cent of samples could exceed 10 parts per billion (ppb) in order to be in compliance.
- In 2008 and 2009, more than 10 per cent of Toronto’s samples exceeded 10 ppb. In June-October 2008, 52 per cent of samples exceeded 10 ppb. In June-October 2009, 18 per cent of samples exceeded 10 ppb.
- As a result of the exceedances, the MOECC mandated the City of Toronto to create a Corrosion Control Plan.
- From 2009 to 2017, during corrosion control planning and implementation, the MOECC did not require the City to collect and analyze regulated water samples from homes or businesses.
- In 2017, the Corrosion Control Plan was fully implemented in the drinking water system and the MOECC-regulated lead testing resumed and is required annually.
- In 2017, early results indicated that corrosion control is having an impact on lowering lead levels compared with results in 2008 and 2009 before corrosion control took effect. Of the samples of 55 homes and businesses suspected or known to have lead, two per cent of samples exceeded 10 ppb and none of the samples in the distribution system exceeded 10 ppb.
- The results are available on the City’s website at toronto.ca/water.
- Corrosion control involves adding phosphate to the drinking water system to form a protective coating on pipes and household plumbing fixtures, which helps to reduce the potential for lead to enter tap water.
- Corrosion control, mandated and approved by the MOECC under the Safe Drinking Water Act, was adopted by City Council, and is supported and endorsed by Toronto Public Health as a safe way to reduce the amount of lead in tap water and reduce the associated health risks.
- It costs approximately $3 million annually to add phosphate to the drinking water system and remove excess phosphate from treated wastewater before it is released into the lake.
- The City of Toronto is continually evaluating the effectiveness of corrosion control and is adjusting the phosphate dose accordingly. The phosphate used at the City’s water treatment plants is a food grade additive derived from a natural source of mineral rock. It has no impact on the taste or odour of the drinking water.
Lead mitigation strategy
- In 2011, Toronto City Council approved the Lead in Drinking Water Mitigation Strategy, a multi-pronged approach aimed at protecting public health by reducing lead in drinking water. Components of the strategy include: free, non-regulated lead testing, corrosion control, lead pipe replacement and tap-water faucet filters.
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Media contact: Kris Scheuer, Strategic Communications, 416-338-0698 Kris.Scheuer@toronto.ca