Pacific Southwest, Region 9: Superfund
Serving Arizona, California, Hawaii, Nevada, the Pacific Islands, and Tribal Nations
EPA #: CAD066635442
Congressional District: 52
On 10/13/17, this website will no longer be updated. Site information will be migrated to the new web page at: http://www.epa.gov/superfund/stoker .
EPA appreciates your patience through this transition. If you have questions, please contact EPA staff listed below.
On this page
Description and History
NPL Listing History
NPL Status: Proposed
Proposed Date: 07/29/91
The Stoker Co., which is located in a sparsely populated agricultural area, has supplied and aerially applied pesticides since 1966. Waste and rinse waters resulting from the cleanup of equipment are sprayed onto a 20-acre land treatment unit, which consists of a dirt road and landing strip. Studies have shown that in the 1970s close to 300 gallons of waste waters per day were disposed of in the land treatment unit; this amount dropped to 100 gallons sometime before 1988. Empty pesticide bags and boxes were also burned on site. While the disposal of waste waters is permitted by the California Regional Water Quality Control Board (CRWQCB), the Stoker Co. is required to sample the soil and the groundwater beneath the site. In 1988, birds and fish that died in a pond at a nearby residence were found to have high levels of pesticides in their tissue. This discovery alerted local authorities to site contamination and resulted in the closing of the pond. Shortly afterwards an on-site warehouse containing pesticide supplies burned to the ground. The Stoker Co. responded to this incident by removing contaminated soil, an action performed under the Resource Conservation and Recovery Act (RCRA). In the early 90's, Stoker initiated closure of the land treatment unit (including areas at the runway). This work is being overseen by CRWQCB. A canal runs along the southern and eastern borders of the airstrip, delivering water to a residence less than 80 feet from the site, wetlands, and a fishery. The wetlands also border the entire length of the airstrip and provide a habitat for four endangered or threatened species. The fishery, which raises catfish, is located within 1/4 mile of the site. Close to 130 people live within 1 mile of the site.
Contaminants and Risks
- Surface Water
- Soil and Sludges
- Environmentally Sensitive Area
Even though the site is located in an agricultural area where pesticides are used extensively, the levels of pesticides in air, surface water, sediment, and soil samples greatly exceed background concentrations. In 1988, several pesticides were detected in the canal. Pesticides also were found in on-site soil and the pond. Sediment and air samples collected in 1989 indicated that pesticides had been released into the air and the wetlands.
Who is Involved
This site is being addressed through Federal, State, and potentially responsible parties' actions.
Investigation and Cleanup Activities
This site is being addressed in two stages: immediate actions and a long-term remedial phase focusing on cleanup of the entire site.
Immediate Actions: In 1988, after discovering contaminants in dead birds and fish, local authorities closed the nearby pond. In response to the 1988 fire, approximately 300 tons of contaminated soil were removed and disposed of in a landfill regulated under the Resource Conservation and Recovery Act (RCRA).
Entire Site: In early 1993, the EPA evaluated the site to determine if any additional immediate actions were necessary. Assessment results indicated that further actions were not warranted at the site at that time. The EPA is currently evaluating the scope of any additional investigations pending the site's final listing on the NPL.
Cleanup Results to Date
Immediate actions such as closing the pond and removing contaminated soil have reduced health and safety risks to the nearby population and environment while further investigations into contamination at the Stoker Co. site are being planned.
Potentially Responsible Parties
Potentially responsible parties (PRPs) refers to companies that are potentially responsible for generating, transporting, or disposing of the hazardous waste found at the site.
Online information about the PRPs for the site is not yet available.
Documents and Reports
No documents found
Public Information Repositories
The public information repositories for the site are at the following locations:
EPA Site Manager
EPA Community Involvement Coordinator
San Francisco, CA 94105
EPA Public Information Center
After Hours (Emergency Response)