Valley's TCE water scares unprecedented in U.S.

Two recent drinking water contamination scares that affected Scottsdale and Paradise Valley customers were unprecedented in Arizona, and possibly the nation, federal environmental regulators said Thursday.

“I do not believe that it has happened in the rest of the country,” said Keith Takata, Environmental Protection Agency Superfund Division director.

At the behest of U.S. Rep. Harry Mitchell, D-Ariz., the House Subcommittee on Water Resources and Environment, held a hearing in Washington Thursday involving the trichloroethylene, or TCE, scares at a private drinking water facility that serves residential and commercial customers in Scottsdale and Paradise Valley.

“I felt pretty good that the EPA knows our concerns and will respond to them,” Mitchell said in a phone interview.

The congressman said several questions remain unanswered about how elevated levels of TCE, a suspected cancer-causing chemical, entered the drinking water supply of Arizona American last October, and then again in January.

In the wake of the second spill, it remains unclear why three different alarms failed to notify technicians of an equipment failure, why the treatment process was left unsupervised overnight — allowing high levels of TCE into the company’s water supply — and why the utility’s customer notification system was insufficient in alerting the public, Mitchell said.

Customers may have been exposed to TCE levels on Jan. 16 of quadruple the maximum allowable limit after a mechanical breakdown at Arizona American’s Miller Road Treatment Facility. The company had a previous TCE problem in October, but at the time officials said the tainted water was blended with TCE-free water, lowering concentrations to within federal limits.