Anacortes Former Water Treatment Plant
14549 River Bend Rd, Mount Vernon, WA 98273

Location of Anacortes Former Water Treatment Plant next to the Skagit River in Mount Vernon, WA
Please click on the photo for a larger view


Last Updated August, 2019

Cleanup Process Moves Toward Remedial Investigation and Feasibility Study

Información en español

Ecology conducted a public comment period (April 15 - May 14, 2019) on an agreed order (legal agreement) and a public participation plan for the Anacortes Former Water Treatment Plant (Site). The Site is located next to the Skagit River in Mount Vernon and is next to the current water treatment plant, which provides the drinking water for the city of Anacortes and surrounding communities.

The legal agreement between Ecology and the City of Anacortes (City) will require the City to analyze cleanup options and create a cleanup plan. A future legal agreement will require the City to design and carry out the work described in the plan. 

Ecology did not receive any public comments on the documents so they have been finalized.


The Model Toxics Control Act (MTCA; Chapter 70.105D RCW is Washington’s environmental cleanup law). It provides requirements for contaminated site cleanup and sets standards that protect human health and the environment. Ecology enacts the MTCA and oversees cleanups. The MTCA site cleanup process is completed in steps (see graphic below) over a variable timeline. 

Please click on the photo for a larger view


  • Early 2019: Held a 30-day public comment period (April 15 – May 14, 2019).
  • Later 2019:  Complete the Remedial Investigation and Feasibility Study Report. Ecology will provide notice for a public comment period and a public meeting to finalize these documents.
  • 2020:  Select cleanup action. Based on the information in the final Remedial Investigation/ Feasibility Study report, Ecology will select a cleanup action for the Site. We will issue our cleanup action plan and an associated legal agreement for public review. The legal agreement will require the City to design and implement the cleanup action.  


Current Anacortes Former Water Treatment Plant cleanup site Public Participation Plan 

This plan includes information for the public regarding opportunities to get involved in the Site cleanup process. The outreach activities and mechanisms presented reflect Ecology’s current plans for keeping the public informed and for receiving information and comments from the public.

Anacortes Former Water Treatment Plant Site Layout (click for larger image)
Please click on the photo for a larger view


The Site is located at 14489 River Bend Road in Mount Vernon. The former plant was constructed on the property between 1969 and 1970 to treat water from the Skagit River prior to transfer to the City of Anacortes municipal water storage and distribution network. The Site structures were decommissioned in 2013 when the new water treatment plant (built on a different part of the same property) became active.

The Site consists of these decommissioned structures (click on site layout to the left for larger image):

Administration Building:  a two-story building that housed a control room,  laboratory, and chemical additive mixing operations. 

Filtration Basin:  a nearly 8,000 square foot concrete basin that used anthracite,  sand, and gravel for water purification. 

Clear well:  an approximately 12,000 square foot, multi-chambered, concrete  storage space below ground and beneath the Administration Building, Filtration Basin,  and Pump Room.

Waste well:  a concrete structure next to the Clear well where settled particulates  were collected before pumping it to settling lagoons.

Sedimentation Basin:  an over 19,000 square foot concrete basin that featured  gravity flow through the system into clean water overflow troughs for settled  particulate collection. 

In 2015, while conducting a demolition assessment (Hazardous Materials Assessment) of the decommissioned Site, samples of building materials and soil were found to contain polychlorinated biphenyls (PCBs). 

Initial conclusions of the 2015 Hazardous Materials Assessment and related preliminary site investigation studies include:

Building Materials:  PCBs were found in the coating material of the Sedimentation  Basin and some of the building materials of the Administration Building.

 • Soil:  PCBs were only found in shallow soils between 0 to 12 inches below ground  surface on a limited portion of the Site immediately next to Site structures. PCBs  were detected in Site soils at concentrations that exceed the unrestricted land use  cleanup levels under MTCA. These soils are the focus of the Remedial Investigation  and Feasibility Study in development.

Groundwater and surface water:  The field sampling confirmed that there was  no indication of PCBs released to surface water or groundwater. 

The City conducted regular sampling of drinking water produced from the former plant beginning in 1976 and continuing throughout operation. No samples of drinking water tested for PCBs ever contained detectable concentrations of PCBs.

In 2017, the City conducted an Evaluation of Potential Human Health Risks associated with contamination at the Site and determined that no adverse health effects are likely to have occurred to customers, workers, or water plant visitors as a result of PCBs at the former plant. 

For more information, to sign-up for updates, and to view the Human Health Assessment go to: 

For Questions, Contact the City of Anacortes:
• 360-299-1950


Map showing site location as Skagit County, WA SITE INFORMATION


View Electronic Documents

Cleanup Site Details Report

Facility Site ID: # 79423677

Cleanup Site ID: 13264

Mount Vernon, Skagit County

Status: Awaiting Cleanup   Get definitions of Status terminology

Cris (NW) Matthews
Site Manager
(360) 255-4379

Ian Fawley
Public Involvement Coordinator
(360) 255-4382

Document Repositories:

Northwest Regional Office
3190 160th Ave SE
Bellevue, 98008-5452

Ecology Bellingham Field Office
913 Squalicum Way, Unit 101
Bellingham, 98225

City of Anacortes City Hall
904 6th Street
Anacortes, 98221