Mount Vernon Library Commons

Ecology issued a Site No Further Action (NFA) opinion letter on May 31, 2024.  The future development of this Site will be the Mount Vernon Library Commons Project.

Contamination on the Property was successfully remediated to meet Ecology cleanup levels. An environmental Covenant was filed with Skagit County.  

The Site, on 0.75-acre Skagit County parcel numbers P54139, P54141, P54142, and P54147, is located in section 19, township 34 north, and range 4 east of the Willamette Meridian.

The Property is owned by City of Mount Vernon, 910 Cleveland Avenue, Mount Vernon, WA, and is located in the City of Mount Vernon Downtown neighborhood, in an area zoned as Public.

Prior to 1948 the Property was developed as a petroleum products service station and operated by Chevron.

The current redevelopment of the Site into Mount Vernon Library Commons, transit center, and multi-use community space by the City of Mount Vernon led to the discovery and decommissioning of four undocumented underground storage tanks (USTs) the following capacities: 250-gallon, 440- gallon, 1, 200-gallon, and 3,200-gallon.

Environmental assessments were conducted following the discovery of the four underground storage tanks (USTs) at the Site between September 2022 and February 2023.

During the decommissioning of these four USTs, the surrounding soil was observed to be contaminated with TPH-D.

• Approximately 900 cubic yards of petroleum-contaminated soil (PCS) were excavated.
• Approximately 200 cubic yards of which were above state cleanup levels (Model Toxics Control Act Method A) and transported for off-Site disposal.
• Three groundwater samples were collected from temporary monitoring wells installed in these borings and analyzed for petroleum hydrocarbons. Chemical concentrations from all three groundwater samples were below state cleanup levels (Model Toxics Control Act Method A) cleanup levels.

However, due to challenging soil conditions, including wet soil and unstable excavation sidewalls, deeper excavation in the vicinity of the decommissioned 1,200-gallon UST was not feasible. Consequently, an estimated 30 cubic yards of residual PCS containing a TPH-D concentration of 9,000 milligrams per kilogram (mg/kg), exceeding the Model Toxics Control Act (MTCA) 1,500 mg/kg generic TPH Method B direct contact cleanup level. The in-place residual PCS resulted in the enactment of the recorded environmental covenant.

Diesel-range Total Petroleum Hydrocarbons (TPH-D) into soil.

The Model Toxics Control Act (MTCA) 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.

What's In My Neighborhood shows contamination cleanup sites in Washington state. Ecology encourages cleanup of these sites to protect the health of people, plants, and animals. Cleanups are projects that remove, treat, or contain potentially harmful substances.

To report an environmental problem or concern, any time, day or night, use the online reporting form.

Counties: Island, King, Kitsap, San Juan, Skagit, Snohomish, and Whatcom
Email: nwroerts@ecy.wa.gov
Phone: 206-594-0000

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