Manage risks to drinking water sources

Activities that can pose a risk

Certain activities can pose a risk to drinking water if pollutants are released to the environment. Pollutants, also called contaminants, are either:

• chemicals, such as fuels, solvents, metals and pesticides
• biological pathogens, such as bacteria and viruses

If one or more of the listed activities occurs near your well or surface water intake, or within a drinking water protection zone that you have created, then there is a potential for contamination of your drinking water source. Drinking water protection zones are areas of land where drinking water sources could be at risk of contamination from certain activities.

Some of these activities are regulated by the province, with measures taken to protect drinking water sources. If a provincial approval or registration is already in place, you may not need to take additional management actions.

Identify local risks

If you know, or are already concerned, about specific activities that are impacting or may impact your drinking water sources in your protection zone, you can focus your efforts on managing them. 

If you don’t know which activities may be of concern, start by thinking about current activities, as well as future activities to prevent problems from occurring. Take into consideration local activities that may impact your drinking water source, such as those listed in the table above.

Conduct an inventory of activities to help identify activities and prioritize management actions.

Create an activity inventory form

Your activity inventory form can include:

• location of activity and contact names of the owner and/or operator
• type of activity
• age and condition of the facility
• likelihood of a spill
• whether there are any risk management measures in place
• whether the activity is managed by provincial regulations
• whether contaminants associated with the activity are biological pathogen, chemical or both
• if you know any potential contaminants associated with the activity, and whether they have been detected in your drinking water supply

Conduct the inventory

You can use any of the following methods to conduct as comprehensive an inventory as resources (staff, cost, time) allow. These methods are listed in order of increasing resources needed:

• desktop inventory
• windshield survey
• email or online survey
• mail survey
• virtual meetings
• phone survey
• door-to‐door survey
• personal interviews
• field inspections

Choosing an inventory method, or combination of methods, should consider the type(s) of activity(ies), the efficiency of the inventory method and how much detail is needed to make further management decisions.

When conducting the inventory, remember that several activities may be occurring at one facility.

As an alternative to soliciting information about activities on a property, you can make assumptions about activities and then confirm with property owners whether those activities are occurring.

Desktop inventory information sources

You can use readily available information sources to make a list of activities that could pose a risk to your drinking water source, including:

• Google maps and Ontario’s GeoPortal
• current and historical aerial photographs
• telephone directories
• real estate title searches
• zoning and land use maps
• waste management databases (such as Hazardous Waste Information Network)
• fire insurance plans
• environmental reports
• provincial and federal records and databases
• municipal permits and licences

Using these information sources can give you an idea of the types of businesses and other activities in your area to create a desktop inventory of activities that may pose a risk to your drinking water. These sources are available by talking to local residents, or at:

• public libraries or archives
• provincial, regional and municipal government offices

You may want to consider cross-referencing multiple information sources to verify their accuracy.

Map activities

Mapping activities is a simplified way to assess risk and prioritize your management actions. You can use any maps you’ve created that show the location of your drinking water protection zones and add the location of activities in your inventory to see where they overlap.

You can map discrete activities, such as a gas station, with a point (with coordinates) on your map. Activities that extend across greater distances such as sanitary sewer lines, can be displayed as a line feature. Wide-scale activities that cover larger areas, such as application of manure on farm fields, can be represented as a polygon shape.

You can also use more advanced mapping techniques like computerized Geographic Information Systems (GIS). These systems can ‘layer’ data electronically using shapefiles (GIS layer) or spreadsheets with x,y values to represent spatial locations.

You can also upload your data directly into the Source Protection Information Atlas following the steps below:

1. Open the Source Protection Information Atlas, click Tools, and then click Upload Data.
2. Locate your shapefile or spreadsheet using Choose Files.
3. Give your layer a name and symbol and click Upload.
4. You should now see your layer in the Map Legend (note your layer is only temporarily available and no one else can see it).

Prioritize activities

When prioritizing which activities to manage, consider:

• The location of the activity in relation to your drinking water well or intake.
• The type of contaminants associated with the activity.

A basic understanding of common contaminants associated with the risk activity can help you identify which activities are a higher risk and should be addressed first. Identifying priorities will help you direct work to where it is most needed to protect the drinking water source.

You can also consider the age and condition of the facility where the activity is taking place.

Manage local activities that may be a risk

There are many tools available to help develop local management strategies to minimize the risk that identified activities may pose to your drinking water source.

Decide on a management approach

There are several factors to consider when selecting the most appropriate tool or combined approach. Ask yourself:

• Is the activity occurring now? In the past? Predicted to occur in the future?
• How hazardous is an activity, and what is the likelihood of a negative impact from that activity?
• Is the management tool protective enough to manage the activity?
• Do you have the time, staff and resources to develop and administer the tool? Do you have the legal authority to implement the tool?
• How much time will it take to implement?
• Is there community support or opposition from landowners?
• Does the science that determined your protection zone support the type of management tool?

Management tools

Management tools can range from restrictive rules that prohibit certain activities from occurring to less restrictive strategies that help people carry out activities responsibly. The tools listed in the table below are similar to the approaches used in local source protection plan policies under the Clean Water Act.

For municipalities and local planning authorities

There are many tools available to you through Ontario’s land use planning system to help you meet your obligations under the Provincial Policy Statement and other provincial plans, where applicable, to protect sources of drinking water. Land use planning tools generally only apply to future uses.

You can:

• Direct development that may pose a risk to your drinking water source away from the protection zones you identified through official plan policies and zoning by-laws.
• Restrict land uses that may be a risk to your drinking water source.
• Use planning tools, such as a community improvement plan, to provide financial assistance with rehabilitating and redeveloping land, such as brownfields, within your established protection zones to help address historical environmental issues.

The Planning Act allows for regulation of land uses, not activities. Therefore, municipal planning documents may need to identify the land use category or type of development that encompasses the activity or groups of activities in question.

Municipal official plans

The Planning Act requires that certain development applications, such as subdivision approvals, be accompanied by a set of supporting studies for a complete application. Prescribed supporting studies include a servicing options report and a hydrogeological report prepared by a qualified professional (Professional Geoscientist or Professional Engineer), which assesses the groundwater and surface water quality and quantity impacts of the proposed development, and how the impacts will be managed.

Municipal official plans may include policies, with mapping of drinking water protection zones to direct future development away from the drinking water source. Municipal official plans must be consistent with the Provincial Policy Statement, and are required to conform to provincial plans, where applicable, to protect drinking water sources.

You can also use official plan policies to require other studies to support development applications. Additional supporting studies may include:

• Disclosure reports provide details on the activities and operations of the proposed development/use.
• Geotechnical reports prepared by a Professional Geotechnical Engineer characterize the soil condition and the status of groundwater resources (details from this report can also be included in the hydrogeological study). 
• Spill prevention and contingency plans outline design measures, facilities and procedures to avoid and mitigate spills of contaminants.

You can also establish specific support materials, such as a checklist identifying all the required documentation. This type of material can help municipal staff assess the risk to your drinking water source and can be a valuable tool for pre-consultation.

Communal drinking water systems can end up under your care and control. Whether this is a planned transition or becomes necessary due to inadequate operation of the system by the owner, this transition can result in responsibilities that you may not have planned for, including:

• Responsibilities to incorporate the drinking water system into the local source protection plan at your expense.
• Legally binding source protection plan policies that can affect existing property owners, businesses and your municipality.

Consider the long-term ownership of any proposed communal drinking water systems. You can require that development proposals that rely on such systems be subject to conditions as part of the development approval. Conditions could include requiring the developer to complete any potentially required source protection plan technical work or financial assurance to complete such work should the system become your responsibility in the future.

Zoning by-laws

Zoning by-laws are used to control the use of land – the type of land use and the specifications relating to that land use. You can identify zones where certain land uses are allowed. Zoning can be used to restrict uses that may pose a risk to drinking water.

Similarly, a zoning by-law can specify certain required design standards, including the location of a connection to municipal water and wastewater servicing. This can work hand-in-hand with an official plan policy and by-law under the Municipal Act to require connection to municipal sewage servicing. Zoning by-laws also allow you to restrict development that may pose a risk to the drinking water source in areas where there is no municipal sewage servicing.

Site plan control

Site plan control, under Section 41 of the Planning Act, is an important tool in regulating development. It can be used to ensure that the proposed development is designed in a way to minimize risks to your drinking water source.

You can consider developing content in your site plan control guidance document or manual that addresses sites that are located in your identified protection zones.

The table below provides examples of site plan control requirements that you can use to address various activities. Note that zoning by-laws can apply in agricultural areas, but for farms requiring a nutrient management strategy under the Nutrient Management Act, the size of manure storage is generally dictated through nutrient management plans and separation distances under the Act for phased-in farms.

Community planning permit system

The community planning permit system is a land use planning tool intended to help promote development by combining zoning, site plan and minor variance processes into one application and approval process. This gives you a greater range of options than the conventional development approval process and can help protect environmentally sensitive areas and control development, including site alteration and the removal of vegetation.

Municipal Act authorities

Outside of land use planning, you can also consider your authority under other legislation to pass by-laws to control activities. Under the Municipal Act, you have broad powers to pass by-laws, including those that concern the economic, social and environmental well-being of your municipality and the health, safety and well-being of people. Limits apply, and by-laws cannot conflict with provincial acts and regulations. The City of Toronto has similar broad powers under the City of Toronto Act.

You can consider using these and other powers when putting local programs in place to manage certain types of activities in your drinking water protection zones or to help protect your drinking water sources.

Examples of local programs that may have taken the above powers into account include:

• The disconnection of roof downspouts from municipal sewers. This can reduce the volume of water collected by storm sewers, which can reduce municipal wastewater plant overflows, spills or bypasses during storm events.
• The collection of household hazardous waste. This can help keep hazardous substances from being released to the environment through improper disposal.

Building Code authorities

The Building Code sets requirements for the design and installation of on-site sewage (septic) systems, including minimum setbacks/clearances from wells and surface water features such as lakes and streams. Inspection programs for septic systems under the Ontario Building Code can help you identify septic systems that are not functioning properly or are poorly maintained. These may pose a risk to drinking water within a certain distance of wells and intakes. Inspection programs consist of regular inspections of the system and follow up actions to ensure septic systems are properly maintained.

Usually the property owner pays for the cost of the inspection but cost recovery through residential taxes is also an option. Funding programs are available through the Federation of Canadian Municipalities to help your residents offset the costs of replacing defective or substandard septic systems. You can choose who performs the inspections on your behalf such as municipal building inspectors/officials, health department staff, third party contractors or conservation authorities. Property owners also have the option to hire a qualified third party to conduct the inspection. You can decide how to administer and offset the costs of running the program in these cases.

Within source protection areas, the Building Code governs mandatory on-site sewage system maintenance inspection programs. You can establish areas where septic system inspections should happen and then these inspections become mandatory. The Ministry of Municipal Affairs and Housing has published a guide to help you implement a septic system inspection program. Other guides are also available to help you deliver your own program, including the Federation of Ontario Cottagers’ Associations, who have published a guide for septic system re-inspection programs for lake associations.

Municipal education and outreach programs

Municipal education and outreach programs can also raise awareness of protecting drinking water sources among landowners. These programs advise on the steps landowners can take to protect their own private wells and neighbouring drinking water systems, such as ensuring their septic systems are functioning properly and any sources of contaminants on their property (such as fuel oil and pesticides) are properly stored and managed.

You can collaborate with neighbouring municipalities (or upper tier municipalities, where applicable), conservation authorities and/or health units to roll-out education and outreach programs.

An education and outreach program can include:

• written materials, such as brochures, fact sheets, internet sites, documentation of best management practices
• community outreach, such as presentations before local communities, school programs
• special activities, such as workshops, demonstrations and tours, videos, slide presentations
• media liaison, such as press releases

Local circumstances will guide specific education and outreach requirements.

Best management practices can help protect sources of drinking water by providing guidelines for businesses to follow that can help prevent contaminants from reaching source waters. Often, these guidelines have added benefits to the potential polluter, by reducing costs and liability, improving worker health and safety, and enhancing public image.

In addition, you can create incentive programs to help landowners offset the cost of implementing best management approaches.

Conservation Ontario has a wide variety of information and tools to help you undertake education and outreach campaigns on a number of activities that may pose a risk to your drinking water source. In addition, you can also visit local or nearby conservation authority source protection websites for local education and outreach materials.

For Local Services Boards, communities and private landowners

As a Local Services Board, community, or private landowner relying on a shared drinking water source, you have a unique opportunity to protect your drinking water source and those of your neighbours. Even though you do not have the rule-making authority that municipalities and local planning authorities have, you can make a difference by taking steps independently to manage activities that could pose a risk to drinking water.

You can:

• Ensure that septic systems are functioning properly.
• Properly store and manage any on-site sources of potential contamination (such as pesticides and fuel oil tanks).
• Choose native plants and landscaping that may require less fertilizers and pesticides to maintain.
• Ensure proper sealing and decommissioning of nearby abandoned or unused wells.
• Site your well and/or septic system using best practices.
• Self-evaluate the everyday practices and activities occurring around you and/or your community to assess the potential for on-site and off-site contaminants to your system.
• Ensure you have an action plan in place in the event of a spill or contamination.
• Talk to your neighbours and encourage good water stewardship and conservation practices in your community.

Resources are available to help you take action:

• Ontario Ministry of Agriculture, Food and Rural Affairs: Best management practices: Water Wells (Free to order)
• Ontario Well Maintenance Technical Bulletin
• Chapter 4 of the Ministry of the Environment, Conservation and Parks’ Water Supply Wells: Requirements and Best Practices document and the Ministry of the Environment, Conservation and Parks Wells on Your Property webpage
• Smart about Salt
• Conservation Authority information/funding opportunities:
  • Central Lake Ontario Conservation Authority – Well Decommissioning Program
  • Lake Simcoe Region Conservation Authority – Decommissioning, rehabilitation of wells on farmland
  • Toronto and Region Conservation Authority – Rural Clean Water Program
• Source Protection Authority websites:
  • Cataraqui – Best management practices for homeowners and the groundwater protection workbook for well and septic owners
  • Trent Conservation Coalition – Landowners Roles and Responsibilities
• Public Health Units:
  • Region of Peel Health Unit – Private Wells
  • Public Health Grey Bruce – Private Drinking Water
• Risk Management Catalogue
• Septic Smart! provides provincial resources for maintaining your septic system

A watershed approach

Knowing more about your watershed will help you understand how your drinking water system fits into the bigger picture of how land use and water supply needs are managed.

A watershed, also known as a drainage basin or catchment area, is an area of land where rain and snow drains or flows into one water body such as a marsh, river or lake. The Provincial Policy Statement defines a watershed as an area that is drained by a river and its tributaries. Watersheds are generally defined by the elevation of the land, also known as topography and neighbouring watersheds are usually divided by areas of high ground. Watersheds can be divided into subwatersheds based on the size of the watershed and the number of streams contributing to the water body.

All the water that enters a watershed flows to the same place, and contamination and land use in one part of the watershed can affect other parts. Understanding your watershed, and the activities occurring within it, can help manage risks to drinking water sources.

For areas of the province with completed source protection plans, watersheds have been characterized by the following key elements:

• boundaries and subwatershed boundaries
• land uses, population and location of towns and cities
• location of drinking water systems and the areas they serve
• water bodies and types of soil and rock in the watershed
• weather conditions
• surface water and groundwater quality and quantity
• water use and potential stresses on water supply
• activities that may pose a risk to drinking water sources

Watershed resources

Many of Ontario’s watersheds have already been mapped. The resources listed can help you determine your watershed’s boundaries and characteristics. You can add your watershed characteristics to these maps to help you understand the impact of human use activities on your drinking water source:

• Ontario’s Watershed Boundary data (Primary, Secondary, Tertiary, and Quaternary)
• Create or order topographic maps
• Geographic data can be found through the Land Information Ontario database
• Make watershed maps and calculate flow and stream characteristics using the Ontario Flow Assessment Tool
• The Source Protection Information Atlas can be used to see watershed and topographic layers for Ontario

You may also wish to contact your local or nearby Conservation Authority through Conservation Ontario for further resources and assistance.

For municipalities

Planning at the watershed scale is useful for long-term consideration of cumulative impacts of development on drinking water sources. You can use source protection information and actions as part of your strategy to protect your watershed and to provide information for understanding watershed characteristics, risks to watersheds, and threats to water quality and quantity of municipal drinking water sources.

Building on drinking water source protection, broader watershed considerations include the following:

• climate change mitigation and adaptation considerations, including the assessment of severe weather events and drought conditions
• water, wastewater and stormwater servicing needs – location and distribution of systems and potential impacts to the quality and quantity of water
• identification of water related areas, features and functions, like significant groundwater recharge areas, that are necessary for the hydrologic integrity of watersheds
• nutrient assessments and land use scenario modelling – to assist in the development of land use and water management goals and recommendations to address the impacts of growth and servicing
• types of plants and trees, wetlands, and other natural characteristics
• impervious cover, like building roofs, parking lots, and roads 
• environmental monitoring
• fisheries and other aquatic habitats
• habitats of species at risk

You can incorporate this information into your management strategy to protect your drinking water sources.