Water is critical to the diverse habitats and working landscapes of the Lake Champlain Basin. The region’s climate provides enough rainfall to feed 14,700 miles of streams and rivers and fill Lake Champlain with 6.8 trillion gallons of water. Vibrant communities, outstanding recreational opportunities, and a strong environmental ethic that rely on this abundance of water attract more people to the Lake Champlain Basin each year. Pressures from human activities, however, threaten to degrade water quality.


Some toxic substances and contaminants are present in Lake Champlain, but their effects and prevalence are not well understood.

A number of pollutants and contaminants found in the Lake are of potential concern, including microplastics, pharmaceuticals, road salt, pesticides, PCBs, mercury, and other bioaccumulating toxic substances. These substances are generally found at low concentration levels. The long-term effects of low-concentration toxic substances on ecosystem and human health are not well understood.

Law Island is a recent toxic clean-up success story. This 8.5-acre island, located north of Burlington, Vermont, off Colchester Point, was the site of five dilapidated and abandoned structures, two abandoned cars, and associated refuse that left a legacy of toxic contaminants. Tests conducted in 2007 demonstrated lead and asbestos contamination from materials on the island. In partnership with the Vermont Agency of Natural Resources, the Town of Colchester undertook environmental remediation. By the summer of 2012, the site was determined to no longer be an environmental hazard. It is hoped that Law Island will serve as both wildlife habitat and a public recreation site.

Microplastics, small pieces of plastic less than 5 mm in diameter, are a growing concern in Lake Champlain. Microplastics come from a variety of sources and come in different forms; microbeads are found in some personal care products, microfibers from synthetic clothing, and eroded pieces of material from litter and other human sources. These materials often pass through wastewater treatment systems. A recent study conducted by SUNY Plattsburgh found between 10,000 to 15,000 microplastic particles were discharged every day at monitored treatment facilities in the Basin.

Microplastics can be ingested by fish and other wildlife and can cause digestive blockage and altered feeding behavior, which can in turn affect reproduction and overall health. Harmful bioaccumulating chemicals have been found in microplastics around the world; heavy metals and PCBs have been found in microplastics in Lake Champlain. The SUNY Plattsburgh study found fibers to be the most common plastics ingested by the bird and fish species upon which the research focused. The study also found greater amounts of plastics in organisms higher in the food chain, particularly cormorants, bowfin, and lake trout.

As seen in many lakes across the Northeast, the amount of chloride in Lake Champlain is increasing. Chlorides are the primary active ingredient in most winter deicing solutions and are carried to the Lake in spring runoff. Also, water softeners add chloride to water systems, and chlorides typically are not removed by wastewater treatment facilities. High chloride levels can interfere with the survival and reproduction of certain aquatic species, such as plankton and some types of bacteria, and can also indicate the presence of harmful toxic substances like heavy metals. Some invasive species, such as Eurasian watermilfoil, are tolerant of chlorides and can displace native species affected by this form of water pollution.

Dive In: What You Can Do

Don’t trash toxics. Take toxic waste and hazardous items to designated waste drop-off centers. This includes electronics, paint, pesticides, herbicides, motor oil, and items that contain mercury, such as non-digital thermometers and compact fluorescent light bulbs (CFLs).

Look for leaks. Check cars, trucks, boats, and other machinery for leaking oil and other fluids.

Don’t flush unused medications. Return them to a pharmacy or an authorized drug collection site.

Go natural. Reduce or eliminate the application of pesticides and herbicides on your property. Choose less toxic options for pest control.

Clean greener. Use less toxic household cleaners. Not all chemicals can be removed in the wastewater treatment process.

Avoid plastic microbeads. Don’t use personal care products that contain tiny pieces of polyethylene plastic used as exfoliants.

Use reusable. Drink from reusable coffee mugs or water bottles instead of buying disposable plastic versions. Bring reusable bags to the grocery store rather than using plastic or paper bags.