Oil Spills: ECCC Science

June 22, 2023


Did you know Canada holds 7% of the world’s renewable fresh water supply?

Water is a sacred resource that is vital to every form of life! Protecting our water supply means protecting ourselves, our earth, and our future! This is why Environment and Climate Change Canada has created a new field guide to aid in freshwater shoreline treatment options in response to an oil spill, of course with the help of Owens Coastal Consultants, Triox Environmental emergencies Inc., Environmental Mapping Ltd., and ECRC-SIMEC!

How do oil spills happen?

Tanks carrying cargo oil, train carts derailing, and pipelines transporting oil are just a few of the varying causes of freshwater oil spills. Taking accountability in spill prevention and reporting oil spills is the responsibility of all Canadians. Oil spills happen, and when prevention is unsuccessful, being reactive and taking immediate action is the next best thing. Immediacy gives way to responders to determine the best possible way to deal with a spill and prevent damage. The Freshwater Shoreline Response Field Guide was created to give planners and field responders the tools and information needed to promptly respond to an oil spill.

Why was the Freshwater Shoreline Response Field guide created?

Canada is often seen as a “water-rich” country due to the vast amounts of water in forms of rivers, lakes, groundwater, snow, and ice.

The extensive amount of water situated in Canada does not mean that it is all potable. Water supply and availability is restricted in many areas. In some areas (such as the Arctic, interior British Columbia, and Southern Prairies) groundwater supply is limited due to salt levels. There is also heavily polluted water in the highly settled areas of the country that is unsafe for humans, animals, and industrial use and can only be used at a relatively high cost of treatment.

These examples of inaccessible freshwater in Canada serve to highlight how important it is to protect our water and clean up any harmful debris found along shorelines or in water. Environment and Climate Change Canada (ECCC) wants to support those who work to keep our water clean, specifically in the event of an oil spill, which is why this new field guide dedicated to freshwater shoreline environments was developed.

Freshwater vs. Saltwater

The focus on freshwater within this field guide is unique and the first of its kind. There have been oil spill field guides in the past, yet none of them have had a distinct focus on freshwater shoreline environments. There are some definite differences between freshwater and saltwater oil spills including water density, fetch, water levels and flow, and ecosystems.

Water density in freshwater environments is different from saltwater because saltwater environments have dissolved salts. These dissolved salts make saltwater denser than freshwater, which in turn means oil can sink easier and quicker in freshwater.

Fetch is an area where waves are created by the wind, and fetch in freshwater environments is much smaller than in marine environments. The size and height of waves has an impact on oil spill response because of its' effect on safety, equipment suitability and efficacy, as well as the effects of oil behaviour.

Water flow in marine environments is more dominated by tides than in freshwater environments. Although tides are still present in freshwater environments, they are smaller and are masked by seiches. Seiches are an occurrence that happens when strong winds and quick changes in atmospheric pressure push water from one side of a lake to another, resulting in a wave that moves back and forth like a pendulum.

Water levels in freshwater environments are affected by many factors, though the most dominant are precipitation, water storage, and variations with changing seasons. Factors such as ice melt and spring freshet can cause extreme variances in water levels and flow, which can result in oil moving far distances down rivers and into backshore areas.

Freshwater Ecosystems are important for both humans and wildlife. Oil spills in freshwater ecosystems can greatly affect the animals and plants living in nearby waters, along with those who live along its shores and drink water.


Freshwater environments play an important role in the life of every Canadian. Whether it be a river, stream, or lake, each source of freshwater is important in its own way. From food production, to power generation, to household water use, freshwater is a necessity that is relevant to almost every aspect of Canadian life. This field guide helps to protect our freshwater environments and ensure that when oil spills occur, they are treated promptly with the correct tools and techniques.

The Freshwater Shoreline Response Field Guide addresses unique challenges and gaps in the field of freshwater oil spill response. Thanks to the teams here at Environment and Climate Change Canada, this guide aligns with the ECCC Shoreline Cleanup Assessment Technique (SCAT) Manual (ECCC, 2018), and the ECCC Field Guide to Oil Spill Response on Marine Shorelines (ECCC, 2016). Key learnings from the past 25 years have also been influential sources of knowledge throughout the development of this field guide.