TapWaterGuide
Worldwide water safety reference
United States Last reviewed:

Maine Tap Water Quality

about 380
Community water systems
City reports on this site
3
Tracked contaminants
August 28, 2026
Data reviewed

Check a Maine ZIP Code

Overview

Portland's Sebago Lake supply is so clean it holds one of the EPA's rare filtration waivers: the protected watershed delivers water needing only disinfection. Maine's other surface-water systems are similarly well-sourced for the most part.

Maine's real water issue is underground: it has among the nation's highest rates of arsenic in private wells, with roughly half the state on unregulated wells drilled into arsenic-bearing bedrock. PFAS from decades of sludge-spreading on farmland has also emerged as a statewide crisis, with Maine setting some of the country's strictest standards and testing programs.

Common Contaminants in Maine

Arsenic in private wells

Bedrock wells across large swaths of Maine exceed the arsenic limit; an estimated one in ten wells is affected and testing rates remain low

PFAS from sludge-spreading

Land-applied biosolids contaminated farms and wells statewide; Maine banned sludge spreading and funds well testing and treatment

Disinfection byproducts

Occasional exceedances in small systems with organic-rich sources

Violations & Compliance

Public systems have strong compliance, anchored by Sebago Lake's waiver-grade quality. The state's attention is on private wells (arsenic, PFAS), which fall outside federal regulation and depend on homeowner testing.

City Reports for Maine

We haven't published individual city water reports for Maine yet. Use the ZIP lookup for a statewide assessment, and check your utility's annual Consumer Confidence Report for local detail.

Frequently Asked Questions

Sources & References

The safety rating and guidance on this page draw on the following sources. See our full methodology.