Clean Water Act

In May of 2000, the municipal water supply in the Town of Walkerton became contaminated with E.Coli bacteria. As a result, seven people died and thousands more became ill.

Provincial Inquiry

As a result of the events in Walkerton, the provincial government convened an inquiry, which was led by Justice Dennis O'Connor of the Supreme Court of Ontario. In 2002, Justice O'Connor released two report findings and recommendations to ensure safe water supply systems in Ontario.

Part 1 Part 2
Described the events that took place in Walkerton and the series of human and system failures that led to the water being contaminated. Focused on the public policy development for the protection of Ontario's drinking supply. A total of 121 recommendations were made with 22 of those related to source water protection.


Justice O'Connor recommended that drinking water is best protected by taking an approach that uses multiple barriers to prevent contamination from affecting our drinking water, called the "multi-barrier approach." Actions to prevent contamination include water treatment and distribution systems, water testing, and training of water managers.

The full Walkerton Inquiry can be found here:

The Response

In response, the McGuinty Government introduced The Clean Water Act, which received Royal Assent on October 19, 2006. On July 3rd, 2007, the Act and five regulations came into effect. The intent of the legislation is to ensure communities are able to protect their municipal drinking water supplies through developing collaborative, locally driven, science-based protection plans. Communities will identify potential risks to local water sources and take action to reduce or eliminate these risks. Municipalities, conservation authorities, property owners, farmers, industry, community groups and the public will all work together to meet common goals.

The Clean Water Act directly addresses 12 and supports the implementation of 22 recommendations of the Walkerton Inquiry on protecting drinking water at its source made in the Part 2 report. Protecting water at its source is the first step in making that commitment achievable. By stopping contaminants from getting into sources of drinking water — lakes, rivers and aquifers — we can provide the first line of defense in the protection of our environment and the health of Ontarians.

For the first time, communities will be required to create and carry out a plan to protect the sources of their municipal drinking water supplies. The Clean Water Act will:

  • Require local communities to look at the existing and potential threats to their water and set out and implement the actions necessary to reduce or eliminate significant threats.
  • Empower communities to take action to prevent threats from becoming significant.
  • Require public participation on every local source protection plan. This means everyone in the community gets a chance to contribute to the planning process.
  • Require that all plans and actions are based on sound science

This legislation is designed to promote voluntary initiatives but does require mandatory action where needed. The legislation sets out a basic framework for communities to follow in developing an approach to protecting their water supplies that works for them:

Identify and assess risks to the quality and quantity of drinking water sources and decide which risks are significant and need immediate action, which need monitoring to ensure they do not become significant, or which pose a low or negligible risk.

Develop a source protection plan that sets out how the risks will be addressed. Broad consultation will involve municipalities, conservation authorities, property owners, farmers, industry, businesses, community groups, public health officials, First Nations and the public in coming up with workable, effective solutions.

Carry out the plan through existing land use planning and regulatory requirements or approvals, or voluntary initiatives. Activities that pose a significant risk to drinking water sources may be prohibited or may require a site specific risk management plan. This plan will set out the measures that a property owner will take to ensure the activity is no longer a threat.

Stay vigilant through ongoing monitoring and reporting to measure the effectiveness of the actions taken to protect drinking water sources and ensure they are protected in the future.

Clean Water Act Background Information