A new detection of the carcinogen TCE near the San Luis Obispo County Airport has prompted another investigation into its source, two years after regulators pinned the pollution on a nearby machine shop, which denied responsibility.
Recent soil gas samples taken by the SLO County Airport turned up high amounts of TCE at a property located next door to the known TCE groundwater plume, which officials had considered to be "ground zero" for the decades-old pollution in the Buckley Road area.
The newly detected TCE could not have come from the contaminated groundwater next door, according to the Central Coast Regional Water Quality Control Board. That fact alone raised the question again of who really spilled the cancer-causing solvent, which has poisoned more than a dozen area wells.
- Map Courtesy Of The Central Coast Regional Water Quality Control Board
- NEW LEAD Recent soil tests done near the SLO County Airport detected elevated levels of TCE [in the green box], spurring another investigation.
Additional evidence unearthed over the past two years has also cast doubt on the water board's conclusion in 2019 that a machine shop above the TCE plume—Noll Inc.—caused the pollution. As the alleged responsible party, Noll Inc. is required to provide replacement water to affected residents and clean up the TCE.
In late 2019, Noll Inc.'s attorneys deposed a former employee of a geotechnical engineering and testing firm that was once housed next door at 795 Buckley Road, where recent tests detected TCE in the soil gas.
The employee testified that the company, Central Coast Laboratories, had used TCE on-site until the 1980s to dissolve asphalt, receiving it in steel drums as large as 35 gallons. One of the lab buildings was destroyed in a fire in 1981, according to the deposition.
"Central Coast Laboratories and its successors did handle sufficient quantities of TCE to easily be responsible for the groundwater contamination that has been identified in the Buckley Road area," read an October 2019 memo sent to the water board from Avocet Environmental, a consultant retained by Noll Inc. "It is our strong opinion that this new information warrants a far more comprehensive soil, soil vapor, and groundwater investigation of the 795 Buckley Road property."
On Feb. 1, in response to the new TCE tests done by the airport, the water board opened a new investigation. The agency ordered the current 795 Buckley Road property owner, John Coakley, and those associated with Central Coast Laboratories to have further TCE testing performed at the site. The parties submitted a work plan to regulators in April.
The Central Coast Regional Water Quality Control Board declined a request for a phone interview on June 2 and did not return New Times' emailed questions before press time.
John Noll of Noll Inc. said in an email that the recent information should exonerate him and his company from the TCE accusations.
"[Central Coast Laboratories] is the only business location in the Thread Lane/Buckley Road area that used TCE for many, many years," Noll said in written materials shared with New Times. "That's the bottom line." Δ