1900 Block W 1st St, Warden, WA 98857


Draft Cleanup Action Plan, Agreed Order, and State Environmental Policy Act documents

Ecology seeks your input on the following draft documents for the Warden City Water Supply Wells 4 & 5 (site).

  • Cleanup Action Plan — explains our proposed cleanup plan for the site
  • Agreed Order — legal agreement requiring J.R. Simplot Company (Simplot), the party responsible for funding and completing cleanup, to follow the Cleanup Action Plan to remediate ethylene dibromide (EDB) contamination in soil and groundwater
  • State Environmental Policy Act (SEPA) documents — we have reviewed the cleanup actions using the SEPA checklist, and decided they won’t adversely affect people or the environment

J.R. Simplot Company (Simplot), the property owner since 1971, is responsible for cleanup. The proposed plan is to excavate contaminated soil, treat it onsite, and backfill the excavation with treated, clean soil. Groundwater will be monitored semi-annually to confirm contamination is reducing following the removal of contaminated soil.

You can learn more in the fact sheet that was mailed to local residents.

Review the draft documents
Submit comments online or via email or mail by 3/4 to:

Christer Loftenius, christer.loftenius@ecy.wa.gov
4601 N. Monroe St., Spokane, WA 99205
Online comment form

Next steps

We will consider and respond to all comments received during the comment period. If the documents change substantially based on public comments, we will hold another comment period. If not, the documents will be final and cleanup will proceed. We will hold a public meeting if 10 people request it.

EDB soil contamination was found on property owned by Simplot near the city wells.
Please click on the photo for a larger view


In 1989, the City of Warden tested their public water wells in response to changes in monitoring guidelines and found Wells 4 and 5 contained the pesticide ethylene-dibromide (EDB) at levels exceeding safe drinking water standards.

The city notified residents that the EDB levels were not likely to affect the general population, but recommended that pregnant women and children not drink the water. To temporarily fix the problem, the city stopped using the most contaminated well and blended the less contaminated water with clean water to reduce contaminants to drinking water standards.

Then the city stopped using Well 4 and established a new drinking water well. Well 5 will only be used as a back up in an emergency situation. The community's current drinking water supply is coming from Wells 6 and 7. Both wells have been tested and do not contain EDB.

Further investigation found EDB in soil on property owned by Simplot, the party now responsible for cleanup. 


In 2011, we entered into an Agreed Order with Simplot, requiring them to complete a remedial investigation and feasibility study to identify all contaminated areas and propose cleanup options.

The remedial investigation and feasibility study became final after undergoing public comment July 30 through August 28, 2018. We responded to comments from one person. You may read a summary of the investigation findings and four cleanup options in the notice that was mailed to local residents.

We used public input and the information Simplot gathered to write the cleanup action plan. The draft plan is available for public review and comment February 3 through March 4, 2020, before becoming final. 

Then, Simplot will follow the plan to fully cleanup the EDB contamination in soil and groundwater.


Map showing site location as Grant County, WA SITE INFORMATION


View Electronic Documents

Cleanup Site Details Report

Facility Site ID: # 2802409

Cleanup Site ID: 1618

Warden, Grant County

Status: Cleanup Started   Get definitions of Status terminology

Comment Period:
FEBRUARY 03, 2020 - MARCH 04, 2020

Christer Loftenius
Site Manager
(509) 329-3543

Erika Beresovoy
Public Involvement Coordinator
(509) 329-3546

Document Repositories:

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

Warden Public Library
305 South Main
Warden, 98857