Home Depot Wenatchee

The Home Depot Wenatchee Site is 13 acres in size and is bordered on the west by residential property, on the north by Maiden Lane, on the east by Wenatchee Avenue North, and on the south by Walnut Street. The surrounding area consists of residential properties to the west and south, and a mix of commercial, retail, and light industrial properties to the west and north.  

At the time that construction began, approximately 90 percent of the subject property was in use as an active orchard. The associated structures on the subject property included four houses, two mobile homes, and a small storage shed. The central portion of the subject property included a swimming pool, and a level, grass-covered area that was created by filling of a former concrete-lined fish pond. The structures on the subject property were demolished during the initial stages of construction.
 
Based on local topography and the river elevation, the depth to groundwater at the subject property is anticipated to be greater than 50 feet, with groundwater flow to the east toward the Columbia River. Groundwater was not encountered during site activities to the maximum exploration depth of 25 feet.

The remedial action implemented at the subject property included excavation and offsite disposal of ash/soil from the former fish pond with PCB concentrations exceeding site cleanup levels and containment of soils with arsenic and lead concentrations greater than the cleanup levels. Tasks to prepare the site for construction, including removal of three heating oil USTs and five septic tanks, and removal and offsite disposal of organic-rich surface soil, which was not suitable for use as fill, were also conducted as part of the remedial action.

The remedial action for the former fish pond area consisted of excavation from within the pond structure, demolition/removal of the concrete structure, and appropriate offsite disposal of the excavated material. The removal of the PCB-impacted material from the former fish pond was conducted pursuant to the PCB cleanup plan, which was accepted by the United States Environmental Protection Agency in 2003.

Concrete, asphalt, or the store building that was constructed as part of site development capped most of the surface of the subject property. The concrete, asphalt, and store structures contain the arsenic- and lead-impacted soil remaining at the subject property and prevent future users of the property from contacting the impacted soil. The containment also prevents infiltration and controls surface run-on/run-off, and generation of dust due to exposed soil.

In the few areas that were not covered by concrete, asphalt, or the store building, including planting strips, landscape areas, and an area in the southwestern portion of the subject property, the native shallow soil was excavated to a depth of at least 3 feet and backfilled with clean soil. The excavated soil was used as general backfill under impervious surfaces elsewhere on the subject property.

It was determined that the site would be eligible for a no further action determination if institutional controls were implemented in the form of a restrictive covenant to prevent exposure to contained contaminated soils. The restrictive covenant was recorded in 2006.

Based upon cleanup activities and the recorded restrictive covenant, Ecology has determined the site is no longer a threat to human health and the environment. Ecology issued a no further action determination in February 2006.

Periodic reviews are conducted every 5 years by Ecology for sites that have institutional controls. The review is intended to examine the effectiveness of cleanup activities and to assure the continued protection of human health and the environment.

Periodic review results

Asphalt and building structures continue to serve as a cap for the site and eliminate the human exposure pathways (ingestion, contact) to contaminated soils. Additionally, there are several small landscaped areas throughout the site that are covered with clean soil and landscaping mulch and vegetation.

The restrictive covenant for the site was recorded and remains active. The covenant prohibits activities that will result in the release of contaminants contained as part of the cleanup without Ecology’s approval, and prohibit any use of the property that is inconsistent with the covenant. The covenant serves to assure the long term integrity of the surface cover.

Based on the periodic reviews, Ecology has determined that the requirements of the restrictive covenant have been satisfactorily completed. No additional remedial actions are required by the property owner. It is the property owner’s responsibility to continue to inspect the site to assure that the integrity of the site surface is maintained.