On January 31st, 2018, a fatal accident occurred on Highway 20 between the local Grass Valley towing company Kilroys and a Williams Tank Lines gasoline truck out of Stockton. The collision caused an explosion which spilled fuel and oil on the roadway sending dense smoke into the air. Estimates from Cal Fire approximated 12 to 15 thousand gallons of fuel caught on fire during the accident. While much of the gasoline was burned off and evaporated, nearby waterways were still at risk. California Department of Fish and Wildlife (CDFW) acted quickly to respond to the accident and protect the Bear River and PG&E’s Drum Canal.
Given the potential to impact nearby waterways, interagency cooperation allowed for rapid management of the fuel spill. To reduce the likelihood that fuel would travel downstream, PG&E deployed booms (an oil catching device) in the Drum Canal and dropped the flow within the canal to zero. The California Department of Transportation (CalTrans) installed a temporary barrier on the Bear River to stop any passage of potential contaminants. Most contaminants were prevented by the temporary containment structure installed on the Bear River. Inspections did not indicate fish kills or major impacts to aquatic life.
Sediment samples were taken at the accident site and soil contamination was prevalent. The site was excavated, which resulted in the road being torn up and then replaced to remove all contaminated soil and material.
NID took action to make sure no contaminants were moving downstream. On the day of the crash, NID collected water samples along the road that were slightly above detection limits. Through their sampling efforts, NID was able to confirm that the water supply for Nevada City and Grass Valley was unaffected by the spill. Additional water quality sampling following the incident have shown no detections of contamination.
On February 21st, 2018, the temporary barrier on the Bear River was removed by Hanson Brothers, who was hired by CalTrans, PG&E and CDFW. After the removal of the barrier and contaminated soil, additional flows were allocated to the Bear River to flush the system. The containment area in the Bear River was then stabilized with natural materials. The Central Valley Regional Water Quality Control Board is following up with future monitoring and samplings of the area.
SYRCL sends our condolences to the families of the drivers and appreciation to the agencies who swiftly responded to this tragedy.