Water from a south Scottsdale Superfund site laced with nearly double the maximum legal limit of a suspected cancer-causing chemical may have entered a drinking-water supply in Scottsdale during an eight-day period last month, federal officials revealed Thursday.

Scottsdale: TCE scare limited to private supply

Representatives of the U.S. Environmental Protection Agency also said they have rejected Motorola’s request to remove air filters at the Scottsdale Central Groundwater Treatment Facility near 86th Street and Thomas Road, which treats contaminated groundwater from the North Indian Bend Wash Superfund site. Doing so would have put about 6 pounds of a solvent called trichloroethylene, or TCE, into the air each day in an area bordered by residential neighborhoods, according to Motorola representatives.

“The EPA has made the decision that we will keep the filters on,” said Jamey Watt, EPA remedial project manager.

About 70 people turned out for a meeting Thursday to hear about the proposed removal of the air filters. Many were outraged at the announcement that water containing 9 parts per billion of TCE could have been introduced into the drinking water supply. The federal maximum for TCE in drinking water is 5 parts per billion, or 2.5 teaspoons in an Olympic size swimming pool, according to A. Jay Gandolfi, director of a University of Arizona research program on Superfund sites.

Resident Robert Romano said officials had previously promised to notify the public immediately if there were any problems at the treatment plant.

“It’s too late. It’s over. We all drank that water,” Romano said.

Sheryl Bilbrey, chief of the EPA’s Superfund Private Site Section, said the incident happened at the Miller Road Treatment Facility, 5975 N. Miller Road. The facility has three treatment towers, two of which are normally in use.

On Oct. 15, workers at the site shut down one of the towers for inspection and shifted operations to the third, unused tower. Samples were taken of the water leaving the new tower and sent off to a lab, Bilbrey said. The third tower was active for eight days, she said.

Watt said the EPA did not receive the results from tests on the water, however, until Wednesday. That’s because the first lab had equipment problems, requiring that the sample be sent to a second lab. The EPA then notified the public within the seven days required by its own guidelines for the Scottsdale Superfund site, Watt said.

During the tower’s eight days of operation, the tainted water was sent to a facility run by Arizona American Water Co. — a private water utility — where it was blended with water from several other sources before being sent to customers. That water company serves mostly Paradise Valley residents, and about 1,500 Scottsdale residents, Scottsdale officials said.

Company representatives asserted that in the blending, the TCE was diluted to within federal guidelines.

The EPA is investigating how the water may have been tainted.

“Based on what the company has told us, we do not believe anyone was exposed to levels of concern,” Bilbrey said.

But many residents were incensed that they were not told so they could avoid drinking the water during that time.

“I don’t care about the average,” said Hannah Goldstein. “I care about how much my coffee is poisoned in the morning.”

The public should have been notified immediately, Goldstein said.

“Why can’t we make a choice whether we want to drink the water or we don’t while you’re playing around with your labs and your test tubes?” she said.

About the Indian Bend Wash Superfund site

The Indian Bend Wash Superfund site, one of the largest groundwater cleanup projects in the United States, covers a 13-square-mile area in Scottsdale and Tempe. About three-quarters of the Indian Bend Wash contamination is in Scottsdale, covering an area from McDonald Drive to McKellips Road, between Pima Road and 68th Street. It is expected to take 20 more years to clean up 90 percent of all the TCE in the groundwater.

Companies like Motorola used TCE to clean circuit boards beginning in the 1950s. The chemical was dumped down dry wells, sewers and into leaching beds for three decades until it was discovered in 1981 in five wells serving Scottsdale.

Three companies — Motorola, GlaxoSmithKline and SMI Holding, formerly Siemens — are responsible for most of the more than $100 million in cleanup costs.