The Regional Municipality Of York


Drinking Water Source Protection

York Region provides clean, safe, reliable drinking water to more than one million people. It originates from three sources: Lake Ontario, Lake Simcoe and groundwater wells within York Region. Groundwater wells draw water from underground aquifers made up of water, soil and rock.

Everyone plays an important role in protecting drinking water sources.

What is Source Water Protection?

Source Water Protection is a program legislated by the Province of Ontario to protect municipal drinking water sources from contamination or over use. The program protects water supplies from threats within vulnerable areas now and into the future.

What Can Threaten Drinking Water Sources?

Activities that may pose a threat to the quality and quantity of ground and surface water include:

Threats to Drinking Water

What can you do to Protect Drinking Water Sources?

  1. View this map to see if your home, farm, business or land development project is located in or near a vulnerable area.
  2. If you are located in a vulnerable area and you are:
    • A) opening a business or developing the property, you may be required to get a Source Protection Permit called a Section 59 Notice
    • B) an existing business in a vulnerable area, you may require a Risk Management Plan.
  3. You may also be required to complete a Source Water Impact Assessment and Mitigation Plan or Contaminant Management Plan before you proceed.
  4. Get familiar with local drinking water source protection plans:
    1. South Georgian Bay Lake Simcoe Source Protection Plan
    2. Credit Valley, Toronto and Region, Central Lake Ontario Drinking Water Source Protection Plan
  5. Contact a York Region Risk Management Official or Risk Management Inspector at

For more information, please contact

What else can you do?

There are many simple things residents can do to protect drinking water sources, including:

Businesses can also:

  • Find ways to reduce your water usage
  • Develop a Risk Management Plan that can minimize the risk of a spill or leak
  • Find out if you need a Source Protection Permit by contacting
  • Safely handle and dispose of chemicals 
  • Consider low-impact development practices when planning new construction to get run-off from roofs and parking lots back into the ground

Farmers can also protect drinking water sources by:

  • Staying up-to-date with best practices of storing and applying manure, pesticides and fertilizers
  • Creating or updating a Nutrient Management Plan with practices to protect drinking water sources

Landowners, including farmers, can apply for funding for projects that protect municipal drinking water through the Landowner Environmental Assistance Program in the Lake Simcoe watershed and the Rural Clean Water Program in the  Toronto and Region watershed.

York Region Protects Drinking Water Sources by:

  • Conducting a groundwater monitoring program
  • Defining Wellhead Protection Areas for all municipal water supply wells
  • Defining the Intake Protection Zones for Lake Simcoe and Lake Ontario
  • Conducting studies to better understand and manage municipal groundwater supplies
  • Preparing source protection plans
  • Reviewing all development applications to make sure that drinking water sources are protected
  • Helping businesses identify and implement risk management measures

Where We Are Vulnerable

York Region’s water supplies are most vulnerable in Wellhead Protection Areas and Intake Protection Zones. Wellhead Protection Areas are the areas around drinking water wells. Intake Protection Zones are the areas around surface water (lake) intakes.

Wellhead protection zone and Intake protection zone

Wellhead Protection Areas

The length of time that it takes for a contaminant to reach the well depends on the distance from the well and the thickness and type of sediment between the surface and the aquifer. An aquifer is an underground layer of sediment or rock that is full of water that can be accessed by a well or spring. Generally, the concern that contaminants from human activity could enter the water supply is highest in the areas close to the wells.

Wellhead Protection Areas (WHPA) are the areas around drinking water wells. It takes a drop of water 25 years to travel to the municipal well from this area once it is in the aquifer. WHPAs are determined by soil types (i.e. water travels faster through sand than clay) and water pumping rates.

Intake Protection Zones (IPZ) are the areas around surface water (lake) intakes. It takes 2 hours for water to reach the intake pipe from this zone.  Intake protection zones are determined by wind, water currents, water temperature and water pumping rates.

Highly Vulnerable Aquifers (HVA) are portions of the landscape that are vulnerable to contamination, based on depth to the aquifer and type of materials above it, for instance, clay versus sand or fractured rock.

Significant Groundwater Recharge Areas (SGRA) help maintain water levels in drinking water supply aquifers. These are areas with porous soils such as sand or gravel that have higher than average infiltration rates and are hydraulically connected to a groundwater supply well.

WHPA-Q / Recharge Management Area (WHPA-Q/RMA) are identified to ensure York Region has a sustainable supply of groundwater. A water quantity risk assessment, identified a groundwater recharge management area. The assessment considered drought, future water demand, land-use change and population growth.

View Recent News Articles:

Local Businesses Help Protect Drinking Water Supplies in York Region

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Related Resources

Drinking Water Source Protection Fact Sheets:

New developments,construction,water,water protection,wellhead protection areas,intake protection zones,surface water,groundwater,clean water act,famers,landowners,apply for funding The Regional Municipality of York en-US Drinking Water Source Protection Drinking Water Source Protection We all play an important role in protecting York Region’s underground and lake water drinking water sources. Find out what York Region is doing and what landowners can do to help.

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