Drinking water source protection in Ontario 20 years after Walkerton

By Carl Seider, Mary Lynn MacDonald, Donna Clarkson, David Ellingwood, Amy Dickens, Chitra Gowda, Melissa Carruther and Kyle Davis

It has been twenty years since a municipal drinking water well in the Town of Walkerton, Ontario, became contaminated with deadly bacteria. Seven people died due to the contamination, and thousands of residents were left with severe long-term illnesses, including neurological damage, arthritis and kidney failure.

It was a tragic event that quickly came under a public inquiry by the provincial government. The inquiry was led by Justice Dennis O’Conner, and resulted in major legislative and policy changes in Ontario to ensure clean, safe municipal drinking water.

Ontario’s Clean Water Act for protecting sources of drinking water

The Ontario Clean Water Act was established in 2006. Administered by the Province of Ontario, this legislation mandates the protection of sources of water for municipal residential drinking water systems. Certain other types of drinking water systems can be included as well.

Under this Act, 19 local multi-stakeholder source protection committees were established to guide source protection planning efforts across Ontario. They are supported by 38 source protection authorities, comprised of Ontario’s 36 watershed-based conservation authorities, the Severn Sound Environmental Association, and the Municipality of Northern Bruce Peninsula. Some of the corresponding 38 source protection areas are grouped into larger regions.

The committees developed 38 local plans that contain more than 12,500 policies, to bring about actions to protect sources of municipal residential drinking water systems across Ontario. The source protection plan policies are based on strong science. Using local scientific data (like soil type, watershed time of travel of contaminants, depth of aquifer, etc.), drinking water vulnerable areas were delineated per provincial technical methodologies.

There are four types of vulnerable areas: wellhead protection areas, intake protection zones, significant groundwater recharge areas, and highly vulnerable aquifers. If a water quality issue is identified by a committee, an issue contributing area can be delineated within the vulnerable areas. Examples of water quality issues identified in Ontario include nitrate and chloride. Within the vulnerable areas, activities are identified that could pose a threat to drinking water sources under certain circumstances. Risk assessments determine risk levels of each threat activity as significant, moderate or low.

These in turn influence the policy tool chosen by the committee, and whether the policy is legally binding or not. Various policy tools and their implementers include: land use planning mainly by municipalities; risk management plans by Risk Management Officials (RMOs); educational and monitoring programs by conservation authorities and others; prescribed instruments by the provincial government; and in limited instances, prohibition by RMOs, municipalities or provincial government.

Source protection plans guiding local actions

Source protection plans have been in effect for around five years. Various source protection authorities and municipal partnership groups across Ontario describe the progress achieved in policy implementation.

The Saugeen, Grey Sauble, Northern Bruce Peninsula Source Protection Region, comprised of three source protection areas, covers a large portion of Grey and Bruce Counties in Ontario. Project Manager and RMO Carl Seider indicates that the region has the responsibility of overseeing plan policies, including for the municipality of Brockton where the community of Walkerton is located.

The local source protection committee developed its policies through a science-based approach premised on provincial technical rules. For example, the development of Intake Protection Zone – 3 (Event-based Areas) were assessed based on modelled fuel spills of various volumes, to determine the level of risk and appropriate protection measures.

Through this analysis, the majority of fuel handling and storage threats were managed through risk management plan requirements, with only a couple of areas identified as prohibition zones for future fuel storage activities. Risk management measures in these areas include requirements to develop and maintain spill prevention and response plans, secondary containment systems, spill cleanup and disposal measures, and spill alerting and notification systems.

This committee has tapped into expertise available at the Walkerton Clean Water Centre over the years through scientific assessments, policy development and more. The region has worked especially well with partner municipalities through the implementation of land use planning restrictions and Clean Water Act Section 59 screening processes to ensure that existing and future drinking water threats are effectively managed.

In this capacity, Grey Sauble Conservation has been designated RMO responsibilities on behalf of 13 municipalities, and has successfully negotiated over 150 risk management plans since the local plan came into effect in July 2016.

Mary Lynn MacDonald and Donna Clarkson are project managers for the Ausable Bayfield Maitland Valley Region. They are also appointed RMOs, who negotiated close to 100 risk management plans with landowners for activities, including the application of manure, pesticide and fertilizer. MacDonald says that working in a prime agricultural region brings challenges and rewards. Based on her experiences, farmers have always been early adopters of technology, and this helps to protect municipal water supplies.

Risk management plans often reflect the embracing of technology, and include measures such as: specifying GIS data layer options for incorporation into farm guidance equipment and “As Applied” maps reporting the actual application rates, timing and areas covered. Many farmers use certified crop consultants and custom application services, so it is important for those partners to be part of the risk management plan development and reporting process. Innovative ideas, such as soil sampling at double the normal depth for high nutrient requirement crops like corn, can determine if nitrogen and phosphorus have infiltrated past the root zone (and in what levels), by harvest time.

This allows for application rates, timing and method of application to be adjusted as needed in the future. Pesticide licensing, 4-R nutrient training or other industry certification is also recognized in risk management plans.

Climate change is also having an impact on the watershed, so region staff participated in a climate change vulnerability assessment pilot study. It was led by Conservation Ontario, the network organization of Ontario’s 36 conservation authorities. The Municipality of Huron East generously assisted to gain an understanding of climate change impacts on the source water quality of their wells.

David Ellingwood is the source water protection supervisor at the North Bay-Mattawa Conservation Authority. He reports that cyanobacteria blooms were identified as a drinking water issue for the Callander drinking water system. Callander is a small community on Lake Nipissing near North Bay, Ontario. The microcystin toxins from certain cyanobacteria are a known health hazard. Phosphorus fuels cyanobacteria blooms.

Water quality monitoring has been conducted for over 20 years by the conservation authority in Callander Bay and its main tributary of the Wasi River and Wasi Lake. A phosphorus budget showed that anthropogenic inputs have added to physical conditions in the watershed and the bay to elevate phosphorus levels. Anoxic conditions develop periodically at the bottom of the bay and liberate phosphorus from the sediments.

Periods of high flows on the Wasi River cause erosion in drains, at culverts and along meanders, adding to the phosphorus load. Charcoal filtration at the water treatment plant can remove the toxins. However, source water protection seeks to reduce contaminants in the first place. The local source protection committee developed policies to address the issue. Septic systems within 120 m of tributaries are inspected every five years under the Ontario Building Code.

Environmental permits, such as for the Callander sewage lagoons that discharge into the bay, have been reviewed. An education and outreach program is ongoing, including practices to reduce phosphorus movement from agricultural and other lands. A successful educational stewardship program called Restore Your Shore has helped prevent erosion and runoff from hundreds of metres of shoreline. Partnerships with academia are helping to better understand the factors contributing to cyanobacterial blooms.

Amy Dickens is the project manager and RMO at the Quinte Region Source Protection Authority. She reports that the authority saw large community buy-in from early on in the program. From 2007 to 2014, stewardship grants supported 90 projects in the region to address activities posing a significant risk to drinking water sources.

Through this grant program, half of all septic systems around the drinking water intake for the Village of Ameliasburgh (Prince Edward County) were upgraded or replaced entirely. As a result, the village’s raw water quality results showed a decreasing trend in E. coli levels, demonstrating the benefits of protecting drinking water right at the source.

Community buy-in has continued, and is paramount to, the success of the policy implementation stage as well. Dickens also says that when landowners in Madoc Township became aware they would be required to negotiate a risk management plan, they took proactive measures based on information from the region’s consultation letters and education materials.

Prior to meeting the RMO, they added measures to their farm operations. This included using the fields closest to creeks for hay only, installing fences to keep cattle out of creeks, and adding vegetative buffers between fences and creeks. Dickens and her colleagues at source protection authorities across Ontario believe that it is also important to highlight the tremendous work and advancements in water treatment and delivery by municipalities.

She and others developed the “Trust the Tap” campaign to commemorate the 20 years since the Walkerton tragedy, and raise awareness about work being done to supply clean, safe municipal drinking water.

The Severn Sound Source Protection Authority, which is not a conservation authority, is part of the South Georgian Bay Lake Simcoe Source Protection Region. This authority consists of eight municipalities, with 32 groundwater systems and two surface water systems.

Melissa Carruthers, RMO for all eight municipalities, reports on progress made. Throughout the pandemic, she continues to provide comments on development applications, respond to landowner inquiries, negotiate draft risk management plans, conduct land use restriction screening, and several other tasks necessary for the protection of local municipal drinking water sources.

Prior to the pandemic, negotiations of risk management plans were going well, with buy-in from the industrial, residential, commercial and agricultural community. This was despite the challenges of implementing a prohibition on commercial fertilizer containing nitrogen on 270 residential properties in a nitrate issue contributing area around municipal wells. The same issue contributing area also involves risk management plans with eight agricultural producers, to help manage nutrient runoff.

Besides having a crucial role in drinking water treatment and supply for over 80% of Ontario’s population, municipalities implement around two-thirds of the source protection policies in Ontario. This includes land use planning, where planners proactively review development and building applications for source protection considerations.

Kyle Davis is the RMO at Wellington Source Water Protection, a partnership between the eight municipalities of Wellington County, formed to implement five source protection plans. He indicates that this arrangement ensures consistent and efficient delivery while meeting the local municipal needs, and was modelled after other shared service arrangements within the County.

Davis works with County and local municipal staff on all aspects of the program, including delivery of education, review of development applications (approxi­mately 250 per year), verification of activities, including inspection and negotiation of risk management plans, completion of over 640 septic inspections every five years and updates to the County Official Plan and local municipal zoning by-laws.

In 2016, the County Official Plan was amended, along with most of the zoning by-laws in the years following. Davis also notes that there have been a number of technical and policy updates, including water quantity (Tier 3) studies and delineation of new wellhead protection areas and chloride issue contributing areas, since the source protection plans became effective.

Elements of successful source water protection

Source protection authorities indicate that the success of the Drinking Water Source Protection program in Ontario is largely attributable to the reliance on sound technical information, strong working relationships with local municipalities and provincial ministries. Also, there has been overall support from landowners who understand the need for ongoing protection of our drinking water sources.

Source protection planning continues, as we face ongoing and new challenges including climate change.

Carl Seider is with the Grey Sauble Conservation Authority. Email: c.seider@greysauble.on.ca. Mary Lynn MacDonald and Donna Clarkson are with the Ausable Bayfield Conservation Authority. Email: mmacdonald@abca.ca, dclarkson@abca.ca. David Ellingwood is with the North Bay-Mattawa Conservation Authority. Email: david.ellingwood@nbmca.ca. Amy Dickens is with Quinte Conservation. Email: adickens@quinteconservation.ca. Chitra Gowda is with Conservation Ontario. Email: cgowda@conservationontario.ca. Melissa Carruthers is with the Severn Sound Environmental Association. Email: mcarruthers@severnsound.ca. Kyle Davis is with the County of Wellington. Email: kdavis@centrewellington.ca

Read the full article in ES&E Magazine’s June/July issue below.