The 2025 Annual Water Quality Report of Sebago Lake

We are proud to say that mainelove water comes from Sebago Lake, one of the cleanest and most protected lakes in the nation. This isn’t just a claim; it’s reinforced year after year by the Portland Water District’s Annual Water Quality Report, including the most recent 2025 report.

Sebago Lake is widely recognized for its exceptional water quality. In fact, the water is so clean that it is exempt from filtration requirements under the U.S. Environmental Protection Agency’s Surface Water Treatment Rule. This is an extremely rare distinction: out of more than 13,000 surface water supplies across the country, only about 50 meet the strict criteria required for this exemption.

What does that mean for the water you drink? Because Sebago Lake water does not require filtration, it avoids many of the chemical and mechanical processes commonly used elsewhere. Filtration systems often rely on added chemicals and treatments that can alter the water’s natural mineral balance and affect taste. Sebago Lake’s purity keeps the water closer to its natural state -- clean, crisp, and great-tasting.

The Portland Water District continuously monitors the lake and the water supply through rigorous testing that meets or exceeds state and federal standards. The annual report details testing for bacteria, organic and inorganic compounds, metals, and other potential contaminants, all of which consistently fall well within safe limits. This ongoing stewardship ensures that Sebago Lake remains a reliable and protected source of drinking water for generations to come.

We encourage you to read the full 2025 Water Quality Report to learn more about how carefully Sebago Lake is monitored and protected.

Read the full report here.

Learn more about the history of Sebago Lake.