The “Triple Confluence Threat” to Groundwater Quality

This article summarizes my work on Karst, groundwater, rural private wells, and agricultural intensification. At the end of this article, you can find my main resources linked.

In short, I believe our region’s rural drinking water is at serious risk, especially for private homes relying on water from private wells. I believe that this threat is serious, may accumulate to billions of dollars in damages to homeowners, as well as sustained injury (e.g. kidney failure) and loss of life. After reviewing similar regions in North America, it is clear to me that contamination will happen – it is not a question of if, but of when. Also, communities will organize and governments will take action – either reactively after the damage is done, or proactively before widespread damage is done. With a first well cluster contaminated, I believe that communities should urgently wake up to protect our shared groundwater that so many of us rely on.

This risk comes from the confluence of three factors:

1. Ultra-vulnerable groundwater aquifers due to soluble Karst and/or fractured bedrock formed in the Silurian age. This bedrock spans from Niagara Falls to Tobermory. In much of Ontario, the bedrock is covered by hundreds of feet of loam, protecting groundwater from contamination. However, between Meaford and Tobermory, the protective layer is consistently less than two feet thick. Residents in this area have no access to groundwater sources other than the Silurian bedrock aquifer because deeper wells tap into salty shale.
2. High density of rural residential homes. Over the past few decades, farmers have severed small acreages for residential development, with local governments approving these severances and collecting taxes from new residents. By doing so, governments have accepted responsibility under Ontario’s Environmental Bill of Rights, which guarantees protection from undue contamination. Although constructing private rural wells is a homeowner’s responsibility, access to clean groundwater is a public responsibility.
3. “Contextually inappropriate” agricultural practices, including the spreading of manure and fertilizer, as well as the storage of manure and silage near feedlots, which are unsuitable for ultra-vulnerable aquifers. Larger dairy operations and feedlots are of particular concern, but human waste (Non-Agricultural Source Materials or NASMs) and chemical fertilizers also pose risks. Some feedlot operators truck manure from protected aquifers into our area and spread it on marginal farmland over vulnerable aquifers as part of their nutrient management plans.

Ontario’s agricultural regulations generally permit “normal” agricultural practices that are assumed to protect groundwater under “normal” conditions. Unfortunately, Ontario’s regulations do not adequately account for ultra-vulnerable aquifers like the barely protected Karst formations in our region. What is “normal” and safe elsewhere may present a serious health risk in the Bruce-Grey region. It’s like comparing sleeping with an open window in a cottage versus doing so on an airplane—what’s safe in one context can be dangerous in another.

The Contaminants

I believe two primary contaminants pose the most significant risks from agricultural practices: pathogens from manure, which can be traced to a single point source, and nitrates from fertilizers, which are often spread diffusely and cannot be traced to a single source. Research by the USDA in Wisconsin, with a nearly identical geological context to ours, identified these contamination pathways. Yet, regional groundwater nitrate monitoring remains poor, and standard well-water testing does not check for nitrates at all. We lack an early warning system for nitrate contamination in our aquifers.

A Legal Gap

There is currently inadequate regulatory protection to prevent groundwater contamination in ultra-vulnerable aquifers:

• The Clean Water Act primarily focuses on protecting municipal wells, though it identifies “Highly Vulnerable Aquifers.” The Source Protection Committee can only make recommendations and provide education but lacks enforcement power.
• The Nutrient Management Act defines “normal” manure and fertilizer management, but it does not account for highly vulnerable aquifer conditions, resulting in insufficient protections in regions like ours.
• The Farm & Food Protection Act shields farmers using “normal” practices from nuisance lawsuits, but it fails to address the unique vulnerability of Karst aquifers, making what is safe elsewhere unsafe in our region.
• Several funding programs offer “carrot” policies to encourage sustainable practices, and about one-third of farmers have adopted them. However, when it comes to preventing nitrate contamination, “voluntary” measures aren’t enough. A combination of “carrot” and “stick” policies is necessary to guarantee clean drinking water.

In the absence of stricter regulations, rural homeowners are left with the costly and uncertain option of private lawsuits against individual farmers. These cases are difficult, expensive (with legal fees easily reaching $250,000), and burden homeowners with proving the contamination source. Diffuse contaminants, such as nitrates and pesticides, make identifying a culprit nearly impossible, leaving rural homeowners without any legal protection.

Why Are Historic Severances a Concern Now?

The root cause of this escalating threat is thousands of historic severances that converted agricultural land into residential lots. Retiring farmers have sold much of this land, previously used as pasture, to large cash-crop or feedlot operations. These buyers likely assumed they were acquiring “normal” farmland suitable for standard agricultural practices, such as intensive cash-cropping and feedlots. However, these practices are inappropriate in Karst landscapes, where aquifers are barely protected by thin layers of soil. This reality was created with government approval of severances during the 1990s. These severance applications by farmers, with government approval, has put rural residential homes and agricultural landowners on a collision course over water rights and contamination risks.

Yet, it took several decades until the agricultural landscape changed. As a generation of beef farmers has retired and is in the process of selling off their agricultural lands, new investors – large cash croppers or land investors – have moved into our region. They have turned tens of thousands of acres of perennial pastureland into cash crop land, and crop these with long periods of bare soil. While agricultural productivity increases, damages to the environment – biodiversity, soil health, aesthetic value – are carried by the general public. It is this transition of agricultural land ownership that has turned historic severances into a real liability.

What Can Be Done?

At a minimum, local governments should explore existing regulatory options, both to protect groundwater and limit liability. Governments have already started to act:

• Education: After my presentation to the local Drinking Water Source Protection Committee, the committee and the Grey County Federation of Agriculture published an article in Rural Voice on farming in Karst areas.
• Water testing advocacy: Counties are lobbying for the continuation of free pathogen testing in private wells.

However, more can be done:

• Municipalities can recommend that realtors inform buyers about the specific vulnerabilities of Karst aquifers and “contextually appropriate” agricultural practices.
• Government agencies could promote Wisconsin’s Silurian Agricultural Bedrock Performance Standard as a voluntary guideline. This standard is based on research and restricts agricultural practices over highly vulnerable aquifers.
• Expanded groundwater quality monitoring should include nitrate testing, and well-testing services should be made affordable.
• Homeowners should push for the redefinition of “normal” agricultural practices in Karst landscapes under the Farm & Food Protection Act.
• Farmers and farm organizations should proactively advocate for a solution to a very real conflict between them and their rural residential neighbours. This solution should give BOTH sides fairness. Any solution cannot legitimize polluting the drinking water of these neighbours. But it could bring substantial financial support for transitioning to a mutually compatible landuse.

Once groundwater contamination leads to health and property damage, further actions may be pursued:

• Under the Clean Water Act, clusters of private wells can be protected, giving the Source Protection Committee authority to regulate contamination.
• A class action lawsuit could be brought against government agencies for failing to protect citizens’ drinking water, as guaranteed under Ontario’s Environmental Bill of Rights.
• New regulation may be required to strengthen personal liability in cases of aquifer pollution, especially if farmers historically pushed for residential severances and municipalities approved these.

Preventative measures must be taken now to avoid irreversible aquifer contamination. Waiting until there is significant damage—or worse, harm to human life—will only make matters more costly and difficult to resolve.

Resources

I am happy to assist within my abilities. Please reach out to me!

• Backgrounder on Karst and agriculture
• Presentation to Bruce County Council, September
• Article about the presentation to Bruce and Grey County Councils
  • • Original website: https://www.bayshorebroadcasting.ca/2024/09/10/186973/
    • Download as pdf: Environmental Scientist Calls On Bruce County To Form Proactive Groundwater Safety Task Force
    • Clarification of several mistakes in the article.
• Article on Karst risks, published in the Rural Voice a month after my delegation. It was written by our local Source Protection staff and was brought forward by the Grey County Federation of Agriculture: