Anacortes WWTP approves discharge agreement for Skagit County landfill remediation

Anacortes WWTP approves discharge agreement for Skagit County landfill remediationThe Anacortes wastewater treatment plant will process up to 5 million gallons of manganese-contaminated effluent after the Department of Ecology prohibited direct discharge into the Salish Sea.

Skagit County will discharge an estimated 4 to 5 million gallons of dewatering effluent to the Anacortes sanitary sewer over a 600-day term.

The effluent, generated from the Whitmarsh landfill cleanup, contains elevated manganese levels that exceed surface water standards.

The city will charge a consumption rate of approximately $0.01 per gallon, plus a $100 monthly administrative fee and a $300 permit fee.

The contract allows the city to immediately halt discharges if the influent threatens the wastewater plant's regulatory compliance or mechanical operations.

The Anacortes City Council has approved a water discharge agreement with Skagit County to accept contaminated water from the Whitmarsh landfill remediation site into the municipal sanitary sewer system. The county is currently executing a cleanup under the Model Toxics Cleanup Act (MOTCA), which requires dewatering the site on March's Point to dredge fill material. The Washington State Department of Ecology mandated the sewer discharge after determining the site's water—which contains manganese levels exceeding surface water standards—was too contaminated for direct discharge into the nearby Salish Sea. The agreement allows for the discharge of an estimated 4 to 5 million gallons of water over a 600-day term, or until the county reaches substantial completion of the cleanup project. According to city staff, this volume represents approximately 10% of the Anacortes wastewater treatment plant's dry weather flow, which is well within the facility's existing capacity. Wastewater Treatment Plant Manager Brian Walker negotiated the technical terms of the agreement to align with Department of Ecology requirements and the plant's safe operating limits. Skagit County will pay a consumption charge of approximately $0.01 per gallon, alongside a $100 monthly administrative fee and a $300 permit fee. Public Works Director Logan Lee noted that the county will likely utilize existing sewer mains and pump stations to transport the effluent to the treatment plant, though trucking the liquid remains an alternative option. To protect the municipal system, the contract establishes strict testing frequencies and contaminant limits. The city retains the contractual right to interrupt or terminate the discharge at any time if the influent threatens the plant's operational compliance, or presents mechanical or hydraulic challenges. The council's approval clears a critical hurdle for Skagit County, allowing a previously mobilized contractor to proceed with the remediation work.