Image


about source water protection

Image What is Source Water Protection?
Ontario's Clean Water Act
Source Water Protection Planning
Multi-Barrier Approach
Defining Vulnerable Areas
Effects on Residents and Small Businesses
Major Threats to Source Water Protection

The Ontario government has put strong legislation into place to protect all drinking water sources throughout the province. The Clean Water Act identifies prevention as a fundamental principle and key component of a multi-barrier approach to protecting drinking water and human health.

What is Source Water Protection?

Source water protection (SWP) is the protection of water bodies at the earliest stage possible in order to minimize the potential threats of contamination (i.e. at the lake, river, stream, or other source). This approach incorporates safeguard measures at all stages of the water cycle and wherever water moves and flows. It is a critical first step in what’s called a multi-barrier approach to achieving safe drinking water systems. And, of course, it is more economical and much easier for water treatment plants to purify lake water when it is clean to start with.

Ontario's Clean Water Act

Ontario’s Clean Water Act was passed in 2006 to ensure safe and clean drinking water for all Ontarians. It works to protect water from source to tap so that residents can have peace of mind about the quality of the water they drink.

The Clean Water Act was developed in response to Justice O’Connor’s Walkerton Inquiry Recommendations that came after the Walkerton Tragedy in 2000 when 7 people died and thousands got sick by drinking e-coli contaminated water.

Source Water Protection Planning

The Clean Water Act requires the establishment of Source Protection Committees that must develop local science-based protection policies to safeguard water sources in vulnerable areas. The committees are also expected to raise public awareness about the importance of source water protection, whether it is lake water or municipal well water.

Each of these Committees is actively encouraging public input into the development of a source protection plan. Each of these plans will include policies intended to protect water sources and will be implemented following approval by the Ministry of the Environment. The development of and public consultation on Proposed Assessment Reports has been a key step in this process.

Multi-Barrier Approach

The multi-barrier approach aims to eliminate or significantly reduce the chance of drinking water contamination. It applies a set of preventative procedures, processes, and tools that, when used in combination, provide greater assurance that water will be safe for consumption.

To make sure that the approach is effective, it must be applied all the way from the source of the drinking water to the consumer’s tap. For the approach to be applied successfully, the general characteristics of the water supply and the land surrounding it must be understood. The system is based on sound science.

With a thorough understanding of the water system, all the possible and existing threats to water quality can be exposed and dealt with. The multi-barrier approach considers these threats and ensures that adequate measures are taken to lessen or eliminate their impacts.

The key steps that the approach takes include: selecting the best available source and protecting it from contamination, using effective water treatment, and preventing water quality deterioration in the distribution system. The approach recognizes that each individual barrier may be not be able to prevent contamination on its own; however, the barriers can work together to deliver overall safer drinking water. Although complete protection can never be guaranteed, there is a significantly reduced risk of contamination. This multi-barrier approach also helps ensure the long-term sustainability of water supply systems.

Defining Vulnerable Areas

As part of the Source Protection Planing process, as outlined in the Clean Water Act, four major vulnerable areas need to be mapped and identified for protection:

Each of these four areas of concern can often be found within a watershed. It is important for these areas to be clearly defined and well-publicized so that citizens and businesses can minimize potential threats to drinking water sources.

Significant Groundwater Recharge Areas
A recharge area is the region where precipitation travels into the groundwater source or aquifer. A Significant Groundwater Recharge Area is identified by the relative rate of water flow through surface soil and rock to the water table below.

A recharge area is considered significant when it helps maintain the water level in an aquifer that supplies a community with drinking water, or if it plays a necessary role in recharging cold water streams that fish species need to live.

These areas are typically located where there is sand and gravel from shallow fractured bedrock. The areas have high rates of infiltration and there is the potential for contamination of the groundwater source.

Highly Vulnerable Aquifers
A Highly Vulnerable Aquifer is identified based on its depth and type of land cover. An aquifer is identified as vulnerable if possible contaminants could quickly flow into it and impact water quality. The factors that make an aquifer Highly Vulnerable include: depth, soil and rock cover and the characteristics of the soil or rock surrounding it.

The identification and classification of aquifers within each watershed help to allow for proper management and education and ensure groundwater protection.

Wellhead Protection Areas
Wellhead Protection Areas immediately surround active and decommissioned wells. Land use activities have the potential to affect the quality of water that flows into the wells in these regions. The size of a Wellhead Protection Area depends on the topography, the amount of water pumped from the well, the type of soil surrounding the well, and the direction and speed of the groundwater.

These protection areas are most often split into four categories:

  • 100-metre zone (area of highest risk for contamination);
  • Two-year time of travel (bacteria and viruses from human and animal waste are a concern, as are hazardous chemicals);
  • Five-year time of travel (biological contaminants are less of a concern, but chemical pollutants remain a concern); and
  • 25-year time of travel zone (the most persistent and hazardous pollutants remain a concern).

Once they have been mapped and identified, Wellhead Protection Areas can be accounted for and proper education and protection can occur.

Intake Protection Zones

An Intake Protection Zone is the region, made up of both water and land, surrounding a surface water intake pipe. The size of an Intake Protection Zone is determined by the time that it takes for a material spilled in or near the water to flow into the water intake pipe.

In Ontario, Intake Protection Zones are separated into three categories:

(1) the area immediately adjacent to the intake
(2) an area upstream where a spill might reach the intake pipe before the plant operator can react
(3) a larger part of the watershed where contaminants might find their way into the intake pipe.

The first zone – the area immediately adjacent to the intake – is the most vulnerable as there would be little opportunity for contamination to be diluted before it reached the intake. This zone is usually a 1-km radius around the intake with a setback on land of 120 metres from the shoreline.

The second zone – the area upstream – is determined in three parts: in-water and along the shoreline; upland; and along tributaries. This zone is determined by a minimum time of two hours of travel of any contaminant, depending on the response time of the water plant operator.

The third zone includes parts of the watershed that may be impacted by extreme events such as storms, strong winds, or high waves.

Effects on Residents and Small Businesses

With the introduction of the Clean Water Act, property owners in communities (including residents and small business owners) will contribute to the development of plans to protect the quality and quantity of their source water. The act requires that residents and business owners identify the existing and potential threats that they or their businesses may pose to source waters. They are then required to carry out the actions needed to reduce or eliminate these threats. The key to the successful development of a Source Protection Plan is the participation of the public and all stakeholders involved. For a truly effective Plan to be established, all views, including those of property owners, residents, and businesses, must be considered.

Certain businesses and property owners may be impacted by the Source Protection Plan that is established for their community. Source Protection Plans may have policies that prohibit or limit certain activities in Intake Protection Zones. If restrictions inhibit certain activities, businesses and property owners that are affected may be required to execute risk management plans on their properties to deal with the risks their businesses and operations pose to source waters. Qualified authorities will be able to work with business and property owners to develop effective risk management plans that will identify the steps a property or business owner will take to make sure the activity is no longer a significant hazard.

Major Threats to Source Water Protection

Identifying major threats allows us to properly manage and maintain vulnerable Intake Protection Zones. In urban settings the major threats include:

  • Spills of industrial chemicals and hazardous materials (ex. gasoline)
  • Storage and spreading of road salts
  • Use and spills of fertilizers and pesticides
  • Faulty septic systems
  • Raw sewage spills and bypasses
  • Leakage from landfills
  • Sewage treatment sludge and manure from farming
  • Urban runoff

These human activities introduce contaminants of concern into the environment that can threaten our drinking water. These contaminants include:

  • Microorganisms (bacteria, parasites and viruses)
  • Nutrients (nitrates and phosphorus)
  • Heavy Metals (ex. Arsenic, cadmium, copper, mercury, lead…)
  • Endocrine-disrupting Substances (ex. DDT, atazine…).

All of these contaminants can enter drinking water sources through point and non-point sources. Point sources include industrial discharges and spills, municipal waste effluents, landfill leachate, waste from mine sites, on-site septic systems and leaking underground oil and gas storage tanks.

Non-point source pollution tends to be caused by water runoff that picks up contaminants as it flows. It can be contributed to by all human activities – urban and rural, commercial and residential.

Sources and additional information: