Buckley Road Area Trichloroethylene (TCE) Investigation

Project Description and Background

Buckley Road AreaThe Central Coast Regional Water Quality Control Board (Central Coast Water Board) is the lead agency overseeing the investigation of trichloroethylene (TCE) in groundwater in the Buckley Road area, adjacent to the San Luis Obispo County airport (as shown on the adjacent map). The initial investigation area included properties along Buckley Road, Thread Lane (also known as Noll Road), Davenport Creek Road, Evans Road, Angie Lou Lane, Mello Lane, Three Sisters Road, Hidden Springs Road, Edna Road, Windmill Road, Rancho Oaks Drive, Sherpa Ranch Road, and Airport Drive. Central Coast Water Board staff has conducted drinking water testing at 67 locations. Currently, 9 private domestic wells and 3 industrial wells out of the 67 locations tested since 2015 exceed the safe drinking water standard for TCE (5 micrograms per liter). The current maximum detected concentrations of TCE in a private domestic well and industrial well are 31 and 53 micrograms per liter (μg/L), respectively, and occur in the Thread Lane area. Based on the distribution of TCE detected in supply wells, Central Coast Water Board staff has focused the primary area for further investigation to Thread Lane, Davenport Creek Road, Evans Road, Angie Lou Lane, Mello Lane, and Three Sisters Road, where TCE concentrations are near or above the drinking water standard.

In 2016, Central Coast Water Board staff required the San Luis Obispo County to conduct soil gas and groundwater investigations on its regional airport property to investigate potential sources of TCE associated with industrial operations and old dump sites at the airport. The County completed their fieldwork investigation in early September 2016. The results of the soil gas and groundwater investigation indicate that there is no evidence that a source of TCE is present on the airport property that is contributing to the Buckley Road Area TCE plume. Given the results from the County’s soil gas and groundwater investigations, the next step was for additional investigation and delineation of TCE in the industrial area overlying the highest concentrations of TCE along Thread Lane. Investigations at two of three properties on Thread Lane have been completed and investigation reports submitted. Based on review of the two received investigation reports, the TCE source remains undiscovered. The third property owner started a soil and groundwater investigation in August 2018 with partial funding under a State grant to perform the investigation. This investigation is nearing completion. Additional details on the investigations are provided in the section below entitled "Buckley Road Area TCE Investigation Reports and Correspondence."

Central Coast Water Board staff has created this website to help provide residents with current information. An email subscription ("Lyris") for the Buckley Road Area TCE Investigation has also been developed to keep interested parties notified of current events (you can subscribe to the email list by clicking the link at under "Subscribe to our Email Lists" section).

Check for updated information in the "Announcements & Public Notices" and "Buckley Road Area TCE Investigation Reports and Correspondence" section below. The most recent announcements will be at the top of the list. A summary of Central Coast Water Board actions is also available under the "Executive Officer’s Report" on this webpage.

Buckley Road Area TCE Investigation Reports and Correspondence





Contacto en español

El Consejo Regional de la Costa Central para el Control de Calidad de Agua (Central Coast Regional Water Quality Control Board) está proporcionando esta notificación a propietarios, inquilinos e interesados acerca de nuestra investigación del químico "trichloroethylene", encontrado en aguas subterráneas en el área de “Buckley Road" en San Luis Obispo. Si desea obtener información en español, póngase en contacto con:

Hector Hernandez al (805) 542-4641


Central Coast Water Board