1458 Old Hwy, Malott, WA 98829

Front of store - from the southwest. Photo by Jeff Newschwander, Ecology.
Please click on the photo for a larger view


The Arden’s Store Site formerly operated as a retail store and gasoline station.  A release from an underground storage tank in 1988 caused gasoline vapors to enter the basement of a neighboring home, triggering remedial activities at the Site. 

In 1991, the Site was added to Ecology’s Hazardous Sites List with a ranking of “3". Sites on the Hazardous Sites List are a priority for Ecology, and have completed a Site Hazard Assessment (SHA).  A SHA provides information about the environmental risk of the Site. Risk is based on the amount of contaminants, how toxic they are, and how easily they can come in contact with people and the environment.  Sites are ranked relative to each other on a scale of “1” to “5”; with a rank of “5” being the lowest.

back of residence, recovery well and post office - from the north. Photo by Jeff Newschwander, Ecology.
Please click on the photo for a larger view


Ecology issued an Enforcement Order at the Site in 1991.  Remedial excavation was conducted at the Site in 1993.  Excavated soils were treated by thermal desorption and used as backfill at the Site.  Several groundwater monitoring wells and recovery wells were installed at the Site and sampled annually by Ecology until 1999.  Low levels of gasoline and volatile organic compounds continued to be detected in several wells at the Site, but no additional remedial activities were conducted at that time. 

In 2011, a Phase II Environmental Site Assessment was conducted.  An environmental covenant was recorded in December 2011.  Based upon cleanup activities and the recording of the environmental covenant, Ecology issued a No Further Action letter in May 2012.


Based upon cleanup activities and the recording of the environmental covenant, Ecology has determined the site is no longer a threat to human health and the environment.  The Site was removed from the Hazardous Sites List in September 2012. 

You can find site documents by using the "View Electronic Documents" link in the bar on the right, or requesting information from the Central Regional Office public records coordinator.


Periodic reviews are conducted every 5 years by Ecology for sites that have Environmental Covenants and/or 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

The portion of the Site containing residual contaminated soils is covered by an asphalt parking area and building foundations.  The asphalt surface area in the vicinity of the residual contaminated soils appears cracked but undisturbed.  This surface continues to eliminate direct contact exposure pathways to contaminated soils. 
Soil cleanup levels have not been met at the Site; however, the cleanup action is determined to comply with cleanup standards under WAC 173-340-740(6)(f), since the long-term integrity of the containment system is ensured and the requirements for containment technologies have been met.

The covenant for the property is in place and will be effective in protecting public health and the environment from exposure to hazardous substances and protecting the integrity of the cleanup action.

Based on the periodic reviews, Ecology has determined the restrictions in the environmental covenant are being observed.  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.


Map showing site location as Okanogan County, WA SITE INFORMATION


View Electronic Documents

Cleanup Site Details Report

Facility Site ID: # 419

Cleanup Site ID: 4906

Malott, Okanogan County

Status: No Further Action   Get definitions of Status terminology

Document Repositories:

Central Regional Office
1250 W Alder St
Union Gap, 98903-0009