Well Water Nerd

Copper in Maine well water

In Maine, 0% of 187 tested private well samples exceeded the EPA limit for copper (1.3 mg/L).

Copper leaches from pipes when water is acidic. Above 1.3 mg/L it causes stomach upset, and long-term exposure can harm the liver and kidneys. Blue-green stains on fixtures are the giveaway.

By county, from individual samples

Public monitoring samples against the EPA limit (1.3 mg/L); counties with at least 30 samples.

CountySamplesDetectedAbove EPA limitMedianHighest
Oxford33100%0%00.63 mg/L
Washington4547%0%00.03 mg/L

Sources

  • Individual samples from the USGS Water Quality Portal and state monitoring, summarized per geography. copper counts and shares are listed on each county and town page with their sources.