Behind the Scenes of Ontario’s Water: What You Don’t See

Water monitoring is something many of us know is happening, but the work behind it often takes place out of view. This Earth Day, we connected with Jennifer Winter, Ph.D., Manager of the Water Monitoring Section at Ontario’s Ministry of the Environment, Conservation and Parks, to learn more about what the role involves. Her Q&A offers a look at the day-to-day work, challenges, and surprises of water monitoring.

1.) What does a typical day look like for your team?

No two days are the same, but most involve a mix of data analysis, field work, and problem‑solving. My team spends time reviewing information from groundwater, streams, rivers and lakes across Ontario, looking for patterns or changes that could affect people or ecosystems. That information includes physical conditions including water flow and temperature, chemistry such as nutrients or salts, and biological signals that show how aquatic life is responding. Together, these give us a much more complete picture of water quality than any single measure on its own.

Some days my team is analyzing long‑term monitoring data to understand what’s “normal” for different regions of the province. Other days they’re responding to emerging issues or priorities. The goal is always the same: understanding what’s happening in our waters, why it’s happening, and what it means for drinking water sources, recreation, and environmental health. That understanding directly supports decisions around compliance, planning, and policy.

2.) Most people think water quality is just about E. coli, how does that compare to what you actually monitor?

E. coli is important, but it’s just one piece of a much bigger picture. We monitor a number of measures of water quality and aquatic health, including nutrients like phosphorus and nitrogen, chloride, a range of chemical and microbial indicators, sediments and biological communities. Together, these tell us not just whether water is safe at a moment in time, but why water quality changes and what pressures are affecting it. Water quality can’t be captured by a single number - it’s complex and influenced by land use, weather, location and human activity.

By looking at both short‑term changes and long‑term regional patterns, we can tell whether something is unusual or part of natural variation. Establishing these baselines is critical when assessing risk, setting environmental conditions for approvals, and making sure protection is reasonable, effective, and grounded in science.

3.) What’s something in Ontario’s water that would genuinely surprise people?

Many people are surprised to learn how closely water quality is tied to what happens on land - sometimes far from the water itself. For example soil washed off fields during rainstorms can travel long distances through waterways.

4.) This Earth Day, many people are thinking about their environmental impact, how do everyday things like road salt or urban runoff affect Ontario’s water over time?

Small actions, repeated across millions of people, really add up. Urban runoff carries oils, metals, and nutrients from roads, roofs, and lawns into waterways, especially during heavy rain. Over time, these pressures can slowly change the chemistry and biology of rivers and lakes, making them harder to protect and restore.

5.) What makes this work meaningful for you?

Water connects all of us. Knowing that the work my team does helps protect drinking water, ecosystems, and public health makes it incredibly meaningful. Much of this work happens quietly, behind the scenes, but it supports everyday things people depend on, like turning on the tap, swimming at a beach, or fishing in a local river. Being part of that protection is something I take seriously and feel proud of.

6.) What do you wish more people knew about the work behind keeping our water safe?

I wish more people knew how much dedicated, proactive work goes into keeping our water safe. For me, this work is about preventing risks before they become problems, through careful monitoring, science‑based decision‑making, and strong collaboration across government, municipalities, conservation authorities, land managers, and communities. Protecting water is a shared responsibility, and clean, reliable water is the result of long‑term planning and people working together to safeguard public health and the environment.