Lake Champlain is a reservoir for about 188,000 people, or 32% of the Basin population. Almost all (about 98%) of these people obtain their water from 100 public water supplies monitored and regulated by the states. Vermont has 73 systems, New York has 26 and Quebec has one. Thirty-six of the 100 water withdrawl systems are community water supplies. The remaining 64 are motels, trailer parks, restaurants, and other business. The Federal Safe Drinking Water Act (SDWA) requires public water systems to monitor 84 potential contaminants in drinking water. Visit the US EPA's SDWA Website for more information. Roughly 20 million gallons of water are pumped daily from the Lake.

About 2% of the Basin population, or roughly 4000 people, withdraw water directly from Lake Champlain. Little information is available from either state on the quality of these non-regulated drinking water supplies. It is likely that this water has minimal or no treatment. Because public water systems drawing from the same source have had coliform contamination, it is possible that these individual water withdrawals are similarly contaminated. Untreated water should never be consumed from any surface waters, including Lake Champlain. Residents who do draw their water from the lake are advised to contact their local health department to make sure they safely filter or process their drinking water.

Some of the largest water suppliers in the Basin include the City of Burlington and The Champlain Water District, which serves many cities and towns within Chittenden County (VT). Most of the Plattsburgh area uses ground water and a reservoir outside the City for drinking water.

Public water suppliers in areas affected by blue-green algae have become increasingly knowledgeable about the problem and effective in treating the water so it is safe to drink. In the summer of 2004, raw (untreated) water was tested for toxins at public water suppliers in North Hero, St. Albans, Swanton, and Alburg Springs. Samples of raw water from Alburg Springs and North Hero contained traces of the toxin microcystin, but at levels well below health guidelines for drinking water. Moreover, following treatment, toxin concentrations in the finished (treated) drinking water were below measurable levels.

The boiling and filtering methods used by most private cottages and camps for drinking water, however, are not effective at removing blue-green algae toxins. Owners are advised to contact their local health departments to determine how to prevent this type of toxin exposure.

• Champlain Water District
• City of Burlington Water Department
• Clinton County, NY Public Water Supply Contacts
• VT Dept. of Public Health Laboratory Water Testing Information
• Safe Drinking Water Act - USEPA
• Safe Drinking Water Database