County and state water officials are still trying to discover how high levels of a toxic industrial solvent got into some San Luis Obispo wells.

Representatives from the Central Coast Regional Water Quality Control Board, as well as staff from the SLO County Environmental Health Department, met with concerned residents at a community meeting Feb. 4 to discuss the contamination.

“We don’t have the source identified at this point,” John Robertson, a ground water group manager for the Central Coast Water Board, said at the meeting. 

Concerns over TCE contamination were originally raised in late December. Since then, the water board has tested 61 private SLO wells and found that 11 of those samples contained TCE in amounts above maximum contaminant levels. Much of the contamination was found in wells in the area of Buckley Road, near the SLO Regional Airport. A Feb. 1 statement from Kevin Bumen, the county’s regional airport director, said that the airport was cooperating with the water board’s investigation.

“We are very concerned about water contamination near the airport and are trying to uncover the source,” Bumen wrote. “But we do not believe the airport is the source of the contamination.”

The cause of the contamination may not have come from a recent incident, according to Dr. Penny Borenstein, SLO County public health officer. TCE, an industrial solvent, has been out of use for some time.

“[The contamination] is probably a product from some use in the past,” Borenstein said.

Residents in the impacted area who think their water may be contaminated are encouraged to contact the Central Coast water board at 549-3147.