Brewster Elementary School
502 S 7th, Brewster, WA 98812

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Brewster Elementary School is located on former orchard land and was subjected to historical pesticide applications resulting in area-wide soil contamination.  In 2002, Ecology staff tested the soil at the Site and found lead and arsenic contamination exceeding state cleanup levels. 

Area-wide soil contamination is defined as contamination above state cleanup levels that is dispersed over a large geographic area. The soil contamination in this case is a result of central Washington’s orchard industry. Much of the region consists of current or former orchard land, where long-term pesticide application has taken its toll. Lead arsenate, a pesticide commonly used between the years of 1905 and 1947 to control the codling moth, has been identified as the primary source of increased lead and arsenic concentrations.

Due to their chemical structure, lead and arsenic tend to bond with soil particles and often remain at or near ground surface level for decades, creating an exposure pathway through inhalation and/or ingestion.

Although lead and arsenic are naturally occurring elements, elevated concentrations have been proven to have a negative impact on human health. Young children are generally more susceptible than adults, which is why Ecology has focused remediation efforts on schools.

In 2004, 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.


During the summer of 2006, Ecology staff managed a cleanup at the Site designed to reduce or eliminate the lead and arsenic contamination.  It involved two major steps: 1) placement of geotextile fabric, and 2) import and placement of a clean topsoil cap. New seed was planted to establish grass, and new infield material was imported.

Ecology staff verified through confirmational sampling that the contamination had been completely covered with a layer of clean topsoil.

Following cleanup, an environmental covenant was recorded for the property with the Okanogan County Auditor. The purpose of the environmental covenant is to provide a permanent legal record of the contamination that remains on the property, and to prevent activities at the site that might disturb or damage the soil cap.


Based upon cleanup activities and the recording of a restrictive 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 June 2008.

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 cleanup actions completed at the Site are protective of human health and the environment.
  • Soil cleanup levels have not been met at the Site; however, the cleanup actions were 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.
  • A new environmental covenant has been recorded for the Site that prevents activities that may expose contaminated soils beneath the soil caps.
Based on this periodic review, Ecology has determined that the restrictions of the environmental covenant is being followed.  No additional remedial actions are required by the School District.  It is the School District’s responsibility to continue to inspect the Site to ensure that the integrity of the cap is maintained.


Map showing site location as Okanogan County, WA SITE INFORMATION


View Electronic Documents

Cleanup Site Details Report

Facility Site ID: # 7994127

Cleanup Site ID: 422

Brewster, Okanogan County

Status: No Further Action   Get definitions of Status terminology

Document Repositories:

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