High levels of copper were found in the drinking water of 220 homes on the west side of town last week, the Aquarion Water Co. confirmed Tuesday, Oct. 31.

In a notice to homeowners sent out last week, Aquarion said water tests had revealed copper levels of 1.35 milligrams per liter — 0.05 milligrams higher than the level allowed by the Environmental Protection Agency.

Peter Fazekas, Aquarion’s director of media relations, said there were 15 streets with homes affected by the copper levels.

Those streets are Mountain Road, Oscaleta Road, Peaceable Ridge, Peaceable Hill Road, Revere Drive,, Minuteman Road, Pump Station Road, Eleven Levels Road, Green Lane, Oreneca Road, Trail-End Lane, Old West Mountain Road, Armand Road, Armand Place, and Wild Turkey Court.

The notice states that higher levels of copper can cause gastrointestinal distress in some people. Over several years, high levels of copper in drinking water can also cause kidney or liver damage. The notice states that people with a genetic intolerance for copper or who have Wilson’s disease should consult their personal physician.

Aquarion said it would be installing “new equipment to improve corrosion control at the Oscaleta Wellfield.”

The notice to residents states that “copper enters drinking water primarily as a result of the corrosion of materials containing copper in customer plumbing systems” — such as “copper pipes and brass faucets.”

Fazekas said that the company’s plan would likely involve “some form of pH adjustment.”

“If we adjust the pH level,” Fazekas said, “there would be less copper leaching from [the affected home’s] plumbing.”

Fazekas said the water tests were taken from “the worst case scenario” — stagnant water left sitting in homes’ plumbing for more than six hours. That gave the water ample time to leach copper from plumbing fixtures.

Fazekas said homeowners concerned about the levels of copper in their water may run their faucets “for two to three minutes” to draw fresh water into the system.