12th Ave & Eastern St, Spokane, WA 99212

Cap Surface from the South
Please click on the photo for a larger view


The Sparks & Buttercup Subdivision site was a non-permitted landfill from approximately 1928 until 1960. Domestic refuse, construction debris, scrap metal, and other types of debris were buried here. The site remains undeveloped.
Soil and groundwater samples were collected from the site in 1991. Petroleum products, 4,4 dichloro-diphenyl-trichloroethane (DDT), antimony, arsenic, barium, beryllium, cadmium, chromium, lead, mercury, nickel, and zinc were all detected in soil at concentrations exceeding Method A cleanup levels defined in the Model Toxics Control Act (MTCA), Washington's environmental cleanup law.
In 1992, Kleinfelder, Inc., conducted a subsurface investigation to address groundwater contamination. Groundwater was encountered between 56 and 121 feet below the ground surface in three monitoring wells which were installed at the site.  Arsenic, chromium, and lead were detected in soil samples collected between 24 and 29 feet during the installation of these wells. DDT, lead, arsenic, and chromium were detected at concentrations exceeding MTCA Method A cleanup levels in groundwater samples collected from two of the monitoring wells. 
A landfill gas survey was also conducted at the site at this time. Six landfill gas probes were installed in and around the landfill and sampled over a two day period. These samples did not detect appreciable levels of combustible gas in either the landfill or in near-surface soils surrounding the landfill.
In 1995, two additional groundwater monitoring wells were installed north of the landfill boundary. These wells were monitored quarterly for total petroleum hydrocarbons (TPH), pesticides, polychlorinated biphenyls (PCBs), arsenic, chromium, and lead. Also, gas vapor monitoring was conducted again at six locations around the perimeter of the site to determine if any landfill gas was being emitted. These samples did not detect appreciable levels of combustible gas in either the landfill or in near-surface soils surrounding the landfill.
Sample results from the two years of groundwater compliance monitoring did not detect pesticides, PCBs, TPH, or metals at concentrations exceeding MTCA Method A cleanup levels.
The landfill was covered with a one-foot protective cap of clean soil. The soil was covered with a plastic liner and an additional 1.5 to 2 feet of topsoil. New grass was planted on the topsoil. Additionally, a groundwater compliance monitoring program was started in 1993 to assure the protection of groundwater.
A restrictive covenant was filed that limits how the property may be used. Ecology then issued a No Further Action letter determining that cleanup is complete.

Periodic reviews

We complete a periodic review at least every 5 years after beginning cleanup at a site, as required by MTCA. The purpose of the review is to evaluate site conditions after initial cleanup is complete to ensure people and the environment are protected.

Periodic reviews were completed for this site in 2008, 2014, and 2019. Petroleum products, pesticides, and metals in soil continue to exceed state standards. The protective cap prevents human exposure to the remaining contaminants by eliminating potential ingestion or direct contact. The restrictive covenant for the property ensures that the cap will be protected. 


Map showing site location as Spokane County, WA SITE INFORMATION


View Electronic Documents

Cleanup Site Details Report

Facility Site ID: # 695

Cleanup Site ID: 1140

Spokane, Spokane County

Status: No Further Action   Get definitions of Status terminology

Ted Uecker
Site Manager

Document Repositories:

Eastern Regional Office
N 4601 Monroe St
Spokane, 99205-1265