A broken valve on a well pump may have allowed bacteria to seep into the Kearns Improvement District's water supply, contaminating the tap water delivered to at least 20 homes in west Salt Lake County last month.
District manager Mike Embley said Wednesday the faulty valve may have been malfunctioning since the well, one of seven currently in use by the district, was installed five years ago.The valve, contained inside a metered box underneath the ground, may have sucked bacteria from the surrounding soil into the waterline. That can happen, Embley said, when the system starts back up after being shut down because of a power outage. Outages occur frequently in the Oquirrh Mountains, where the well is located, he said.
"It's in a swampy area," Embley said. "There is constant pressure in those lines, but there are occasional electrical storms up there that can knock out the power. We believe an outage might have caused a back-flow."
Embley said the contamination of fecal bacteria could have reached 1,030 homes in an area between 5400 South and 6400 South west of 5600 West, all of which are served by the well. But he said only about 20 households actually received bad water through their faucets.
Numerous cases of gastrointestinal illness were reported as a result of the contamination, which occurred the first week of January.
The broken valve has been fixed, and the well is back in operation, Embley said.