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
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CURRENT STATUS

Last Updated:  May 5, 2020

RESPONSE
TO
COMMENTS
  
Response to Comments Summary (May 2020)

 

ONLINE
PUBLIC
MEETING
 
Monday, March 23, 2020

View online public meeting

(YouTube Video, 35 min)


COMMENTS   30-day Comment Period:  March 16 - April 14, 2020
View Comments  



2020
FACT
SHEET
English En español

After review of public comments, Ecology is finalizing the Remedial Investigation and Feasibility Study reports. Ecology will make a draft Cleanup Action Plan available for public review and comment (estimated in 2020-2021). This draft Cleanup Action Plan for the Site is based on the information in the final Remedial Investigation and Feasibility Study reports.

On March 16, 2020, Ecology started a 30-day public comment period on two environmental reports for the Anacortes Former Water Treatment Plant (Plant) cleanup site (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 (City) and surrounding communities. 

Ecology also hosted an online public meeting on March 23, 2020. (YouTube video)


The reports, called a Remedial Investigation and Feasibility Study:

  • Describe contamination found at the Site.
  • Evaluate cleanup alternatives.
  • Identify a preferred cleanup alternative.

Field sampling confirmed that there was no release of contaminants to surface water or groundwater. However, contamination was found in some former Plant building materials and shallow soils immediately adjacent to two former Plant structures. Contaminant levels in soils are above residential cleanup levels and must be addressed under Washington’s cleanup law, the Model Toxics Control Act (MTCA). 

In 2017, the City conducted a Site-specific human health risk assessment that determined no adverse health effects are likely to have occurred to customers, workers, or plant visitors as a result of the contaminants at the former Plant. The City’s long-term monitoring confirmed the contaminants have never been detected in any drinking water samples from the former Plant.


GENERAL CLEANUP PROCESS

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. 


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SITE TIMELINE

  • March 16 – April 14, 2020:  Held 30-day public comment period.
  • March 23, 2020; 4:00 - 5:30 p.m.:  Held an online public meeting.
  • 2020:  Finalize Remedial Investigation/Feasibility Study report. Ecology will review and consider all comments received and respond accordingly. 
  • 2020-2021:  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.


PUBLIC PARTICIPATION

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.


Figure displaying PCB concentrations in structure exterior walls; Acronym note: “N.D.” means “not detected.” (Click for larger image)
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CONTAMINATION

PCBs were found in the exterior wall coatings of the Sedimentation and Filtration basins and adjacent soils (see “Soil Removal” in figure below). The thin veneer coating on the exterior of the concrete basin walls of the Sedimentation and Filtration Basins is the source of localized PCB contamination in shallow soils. PCBs in the coatings were also absorbed into the top 1- to 3- centimeters (cm) of the concrete walls, which are just over 20 cm thick. The figure to the right shows the typical PCB concentrations in the coating and adjacent concrete of Site structures. 

No contamination was found in the Sedimentation and Filtration basin interior walls.

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

  • Groundwater and surface water:  The field sampling confirmed that there was no indication of PCBs released to groundwater or surface water. 
  • Building Materials:  PCBs were found in the exterior coatings of the Sedimentation and Filtration Basins and some of the building materials of the Administration Building. This is the source of PCBs in soil at the property.
  • Soil:  PCBs were only found in shallow soils between 0 to 12 inches below ground surface on a limited portion immediately next to Site structures. PCBs were detected in shallow soils at concentrations that exceed the residential/unrestricted land use cleanup level (1 milligram per kilogram [mg/kg]) under MTCA. These shallow soils will be removed and disposed off-Site in a permitted landfill. See figures on page 3.  

For more information on cleanup standards download the fact sheet: “Focus on: Washington’s Environmental Cleanup Law


Preferred cleanup alternative at the Anacortes Former Water Treatment Plant site
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PREFERRED CLEANUP ALTERNATIVE

Removal and Off-Site Disposal

All soils exceeding the MTCA Method A Unrestricted Land Use cleanup level for PCBs (1 mg/kg) will be excavated and disposed off-Site in a permitted landfill.  Structures that represent a source of PCB contamination to shallow soil (the Sedimentation and Filtration Basins) will be demolished and also properly disposed off-Site.

For more information on cleanup standards download the fact sheet: “Focus on: Washington’s Environmental Cleanup Law


Anacortes Former Water Treatment Plant Site Layout (click for larger image)
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SITE BACKGROUND

BACKGROUND AND LOCATION
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. 



City of Anacortes Safe & Clean Water website: www.safeandcleanwater.com
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DRINKING WATER MONITORING AND RISK ASSESSMENT FINDINGS

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:

www.safeandcleanwater.com 

For Questions, Contact the City of Anacortes:
info@safeandcleanwater.com
360-299-1950



 

Map showing site location as Skagit County, WA SITE INFORMATION

Map

View Electronic Documents

Cleanup Site Details Report

Facility Site ID: # 79423677

Cleanup Site ID: 13264

Location:
Mount Vernon, Skagit County

Status: Awaiting Cleanup   Get definitions of Status terminology

Contacts:
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
(425)649-7190

Ecology Bellingham Field Office
913 Squalicum Way, Unit 101
Bellingham, 98225
(360)255-4400

City of Anacortes City Hall
904 6th Street
Anacortes, 98221
(360)293-1900