The Curry County Road Department violated state pollution laws last month when it flushed sediment through a clogged pipe and into the Chetco River near the Port of Brookings Harbor, the state Department of Environmental Quality (DEQ) said Wednesday.

The DEQ was notified Aug. 25 of a dark liquid draining from a pipe into the Chetco River near the port, said Kendra Girard, the Western Region Basin specialist with the agency, in a pre-enforcement notice to the county.

According to the state investigation report, the county road crew was flushing water down the pipe to clear sediment from blocked stormwater lines; Girard asked them to stop after an Aug. 28 investigation.

She also cited the county road crew for violating a state law that forbids “causing pollution to waters … or placing or causing to be placed any wastes in a location where such wastes are likely to escape or be carried into the water.”

The violation is a Class 1 violation, the most serious of three outlined in the law.

“By flushing sediment and other debris into the (Chetco River), the road department caused sediments and turbid water to be released into the waters of the state,” the notice reads. The sediment had built up in the pipes over time, Girard said.

The letter outlines the importance of the Chetco River to the habitat of fish, particularly coho salmon, which are listed as a threatened species under the federal Endangered Species Act.

“Water with high levels of turbidity and sediment can disrupt the food web, have an adverse effect on juvenile fish-rearing and migration and can kill fish,” the notice reads. “This water can clog fish gills, lower photosynthesis in aquatic plants and lower fish-feeding success and (subsequent) growth.”

It is unknown how much sediment was flushed into the harbor.

The violation indicates the activity caused or posed the risk of causing significant harm to the environment; Girard said in the letter to the county that the matter was being referred to the agency’s Office of Compliance and Enforcement for formal enforcement action, which could result in civil penalties.

The county road department can, however, comply with certain actions to reduce the severity of whatever punishment it might receive. Roadmaster Richard Christensen said he is working with DEQ to develop a maintenance plan for storm drains in the port area.

“DEQ’s civil penalty formula used to calculate fines depends on a number of other factors,” Girard said. “They include whether the responsible party had previous violations, their cooperation in correcting past violations, how long the violation occurred, their cooperation in correcting the current violation, and any economic benefit they may have gained by not complying with the rules.”

The county must now submit within 45 days a stormwater management plan that addresses the maintenance of its stormwater infrastructure, including capturing sediment to keep it out of the river. The management plan must then be implemented and photos and written statements to confirm that compliance must be submitted to the DEQ within 60 days.