Anacortes advances $3.5M CSO pump station and emergency water main repairs amid tightening NPDES nitrogen limits

Anacortes advances $3.5M CSO pump station and emergency water main repairs amid tightening NPDES nitrogen limitsThe Washington municipality is navigating stricter regulatory thresholds for its wastewater treatment plant while actively addressing aging water distribution infrastructure through emergency contracts and long-term corrosion protection.

The city received a draft NPDES permit that lowers the allowable nitrogen discharge threshold, prompting staff to evaluate remediation options with the Department of Ecology.

Construction has begun on a $3.5 million combined sewer overflow (CSO) pump station designed to prevent intake capacity backups during heavy rain events.

The city council ratified an emergency contract for the 34th Street water main replacement after the aging pipe experienced three breaks in a single month.

Public Works completed permanent repairs on a 36-inch transmission line from the water treatment plant, installing new magnetic discharge meters to curtail water loss.

An alternatives analysis for the city's biosolids incinerator has been narrowed to five options, with a focus on reliability, operability, and cost.

The City of Anacortes, Washington, is advancing a suite of water and wastewater infrastructure upgrades as it faces tightening environmental regulations and the ongoing challenge of aging pipe networks. During a July 20, 2026, Q2 update, city officials detailed significant capital expenditures, including a $3.5 million combined sewer overflow (CSO) pump station and emergency water main replacements. A key regulatory hurdle for the city's wastewater operations is the recent receipt of a draft National Pollutant Discharge Elimination System (NPDES) permit. According to Councilmember Bruce McDougall, the draft permit lowers the threshold for allowable nitrogen discharges from the treatment plant. Public Works staff are currently in dialogue with the Washington State Department of Ecology to explore remediation options and ensure future compliance. Concurrently, the city is awaiting a draft Title V air operating permit from the Northwest Clean Air Agency for its wastewater treatment plant incinerator. Public Works Director Logan Lee noted that an ongoing alternatives analysis for the aging biosolids incinerator has been narrowed down to five options. The city council is expected to review these alternatives next week, prioritizing reliability, operability, and cost-effectiveness based on recent council surveys. To address wet-weather capacity issues, construction has commenced on the $3.5 million CSO pump station. During heavy rain events, excess stormwater infiltration has historically overwhelmed the wastewater treatment plant's intake capacity, causing backups. The new project involves installing a 10-foot-wide manhole over the main intake pipe to safely manage excess wastewater during overflow events. On the drinking water side, Anacortes is actively managing emergency repairs and long-term asset preservation. The city council ratified an emergency declaration and contract for the 34th Street Water Main Replacement Project. The aging section of pipe suffered three breaks in a single month, necessitating an immediate replacement between Commercial Avenue and M Avenue. The frequent breaks pushed the Water Department's overtime budget utilization to 92% for the year, though overall overtime spending remains below the previous year's total. The city also completed a permanent repair on its "north line," a 36-inch transmission main leaving the water treatment plant that had previously failed due to a nearby sinkhole. The project included the installation of new vaults and two 36-inch magnetic discharge meters to improve reporting accuracy and reduce unaccounted water loss. Looking ahead, the city council is slated to approve an engineering contract to survey the water system's cathodic protection infrastructure. The system utilizes test points to monitor and mitigate corrosion on large water transmission pipes, extending the lifecycle of critical distribution assets.