Damage at Ruth Dam Releases Hydraulic Oil to the Mad River which Supplies Water to Areas of Humboldt County

Trinity County officials say a hydraulic oil release from Ruth Dam has affected portions of Ruth Lake and the Mad River. Officials say there is currently no known risk to the public, though repairs are still pending and reports differ on when the problem first began.

According to a Trinity County news brief issued March 12, the county was notified of the incident on March 11 at approximately 2 p.m. Trinity County Environmental Health is investigating the release and is working with the California Department of Fish and Wildlife’s Office of Spill Prevention and Response and the North Coast Regional Water Quality Control Board.

County officials say response crews have deployed containment booms to capture the oil and limit its spread. Trinity County also said additional releases of hydraulic fluid are expected until repairs are completed. Those repairs are scheduled to be completed by March 18.

A hazardous materials spill report filed with the California Governor’s Office of Emergency Services describes the mechanical issue somewhat differently. According to that report, damage occurred March 3 when a flap gate at the dam’s intake structure failed and hydraulic oil escaped from its containment system.

The spill report states that an oil sheen measuring about 200 feet long and 10 feet wide was observed on the surface of Ruth Lake, which is on the Mad River. The amount of hydraulic fluid observed on the water surface was estimated at about 15 gallons.

The report also notes that absorbent pads were used while response crews traveled to the scene and divers were scheduled to inspect the structure and identify the source of the leak.

The difference between the March 3 mechanical failure described in the spill report and the county’s statement that officials were notified March 11 was not explained in the county’s announcement. We’ve reached out to the Humboldt Bay Municipal Water District which operates the R.W. Matthews Dam at Ruth Lake and is working with Trinity County during the response. Redheaded Blackbelt has sought clarification about the timeline of the failure, the estimated amount of hydraulic oil released, and whether fluid is still leaking from the system.

The district had not responded in the short time between when we requested the information and when this article was published.