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.

DRINKABLE, FISHABLE, AND SWIMMABLE WATER

Lake Champlain continues to provide high-quality and great-tasting drinking water to surrounding communities.

More than 145,000 people rely on Lake Champlain as their source of safe and reliable drinking water—approximately 24% of the Basin’s population. There are 100 public water suppliers in the Lake Champlain Basin (73 in Vermont, 26 in New York, and one in Québec). Most of the drinking water from these sources comes from 35 monitored and regulated public water utilities; motels, mobile home parks, restaurants, and other businesses also treat and use the Lake’s water. A number of seasonal camps and cabins draw untreated water directly from the Lake, but consuming untreated water is unsafe and not recommended.

The U.S. Safe Water Drinking Act requires all public water utilities to monitor for 86 potential contaminants in drinking water. Lake Champlain’s drinking water rarely exceeds limits for any of these 86 contaminants. The Lake’s water is not only safe and reliable, it is award-winning. The 2015 “Best of the Best” People’s Choice Taste Award for North America went to Champlain Water District, which draws water from Shelburne Bay and is the largest supplier of drinking water in Vermont.

Lake Champlain fish can be a safe and delicious part of a healthy diet when consumption advisories are followed.

Fishing is a longstanding tradition on Lake Champlain and continues to be an important way in which people connect with the Lake’s ecosystem. New York, Québec, and Vermont have each determined safe fish consumption levels for their jurisdictions to provide guidance to consumers.

Most of these fish consumption advisories are a result of the presence in fish tissue of mercury, a toxic heavy metal that can cause severe illness, even at low doses. Mercury biomagnifies through the food chain, which means that older, larger fish farther up the food chain typically contain more mercury than small fish. Therefore, a small species such as yellow perch will generally contain lower levels of mercury than lake trout, a large, predatory fish.

Historically, the biggest source of mercury in Lake Champlain is deposition from air pollution, primarily from coal-burning plants and industries in the Midwest. Some common household items, such as old thermometers and compact fluorescent light bulbs, also contain small amounts of mercury that can enter waterways if the items are not disposed of properly as hazardous materials.

Local and national efforts have resulted in decreases in mercury concentration in several Lake Champlain fish species. This was particularly true from the 1990s until 2011, when mercury decreased in nearly all fish species sampled (Figure 1). Between 2011 and 2017, however, the trend reversed, and mercury was found to have increased in all species sampled. The reason for this reversal is unclear, and researchers continue to investigate potential causes for the change. A similar trend has been observed in the Great Lakes region.

Figure 1 - Mercury in fish tissue

Figure 1 | Mercury concentration in Lake Champlain fish tissue

The Lake Champlain Basin’s rivers and lakes are safe for swimming at most times.

Thousands of residents and visitors enjoy swimming in Lake Champlain and its tributaries each year. With 587 miles of shoreline, 54 public beaches on the Lake, and hundreds of swimming holes on rivers in the Basin, there are countless ways to cool off in the summer months. For most of the swimming season, beaches in most places on the Lake are safe and open to the public.

When a public beach is closed for health concerns, it is usually a result of elevated levels of coliform bacteria or presence of cyanobacteria (also known as blue-green algae; Figure 2). Coliform bacteria are usually harmless and are naturally present in all animals, including humans. Elevated coliform levels in water, however, can be an indicator of the presence of harmful disease-causing pathogens. Elevated coliform levels typically occur following rainstorms that wash sediment, pollutants, and bacteria into the Lake.

Figure 2 - Beach closures

Figure 2 | Public beach closures on Lake Champlain, 2015-2017

While Lake Champlain and its tributaries provide a fine way to cool off on a hot day, health officials recommend that swimmers check in with their local municipality about public beach water quality and safety before jumping in. Experts advise waiting 24 hours after a heavy rainfall before entering a water body to reduce the risks associated with exposure to unsafe levels of coliform bacteria or high river flows.

A young swimmer contemplates a plunge. Photo: LCBP.