North Colfax Petroleum Contamination Site
Site Background
The site is about 1,000 feet south of the Palouse River and east of the South Fork of the Palouse River. The site is made up of three main properties that are current or previous gas stations whose owners are jointly responsible for cleanup:
- The Colfax Grange Supply Company, Inc. property at 105 E. Harrison Street and 102 E. Tyler Street
- The PetroSun/Time Oil Co. property at 804 N. Main
- The Cenex property bordered on the north by Tyler Street, to the west by North Main Street, to the south by the railroad tracks and to the east by an unopened City of Colfax right-of-way
In 1999, Time Oil upgraded their facility and found soil and groundwater with petroleum contamination. They installed seven groundwater monitoring wells in 2001 and more in 2002, which detected petroleum in groundwater beyond their property boundaries.
At Ecology's request, Colfax Grange installed groundwater monitoring wells at their nearby property in 2004.
Prior to sampling these wells but also in 2004, Cenex overfilled their underground unleaded fuel tank. An unknown amount of fuel seeped into soil surrounding the tank. Colfax Grange notified Ecology of the leak.
Contamination
Cleanup
In 2007, Ecology entered into an Agreed Order with the Colfax Grange Supply Company, Inc., CHS, Inc., and Time Oil Co., requiring these companies to conduct a Remedial Investigation (Addendum) and Feasibility Study. The purposes of these reports is to determine the extent and locations of contamination and evaluate cleanup options.
In 2013, Ecology published a draft Cleanup Action Plan providing details about the cleanup action selected and how the cleanup will be conducted. Three cleanup alternatives were evaluated to address contamination at the site. Ecology selected Alternative 1, monitored natural attenuation, which is allowing contamination to dissipate through natural processes, for all three properties.
Ecology responded to public comments on the draft cleanup action plan and finalized the plan in June 2013. Cleanup is ongoing.
Documents 17
Legal 4
Document Title | Document Date | Document Type |
Agreed Order: Colfax Grange Supply Signiture | 9/6/2007 | Agreed Order |
Final Agreed Order: North Colfax Petroleum Contamination Site: | 9/6/2007 | Agreed Order |
Agreed Order Remedial Action: North Colfax Petroleum Contamination Site | 9/6/2007 | Agreed Order |
Draft Agreed Order for RI/FS, Scope of Work and Public Participation Plan: : North Colfax Petroleum Contamination Site | 7/1/2007 | Agreed Order |
Public Information 5
Document Title | Document Date | Document Type |
Responsiveness Summary for DCAP, SEPA and DNS: North Colfax Petroleum Contamination Site | 3/25/2013 | Responsiveness Summary |
Fact Sheet DCAP, SEPA, DNS: North Colfax Petroleum Contamination Site | 2/6/2013 | Fact Sheet\Public Notices |
Responsiveness Summary: North Colfax Petroleum Contamination Site | 3/7/2012 | Responsiveness Summary |
Fact Sheet Remedial Investigation and Feasibility Study Reports: North Colfax Petroleum Contamination Site | 1/31/2012 | Fact Sheet\Public Notices |
Fact Sheet Agreed Order for Remedial Investigation and Feasibility Study: North Colfax Petroleum Contamination Site | 8/1/2007 | Fact Sheet\Public Notices |
State Environmental Policy Act 2
Document Title | Document Date | Document Type |
DNS: North Colfax Petroleum Contamination Site | 2/6/2013 | SEPA Documents |
SEPA Checklist: North Colfax Petroleum Contamination Site | 2/6/2013 | SEPA Documents |
Technical Reports 6
Document Title | Document Date | Document Type |
Cleanup Action Plan: North Colfax Petroleum Contamination Site | 2/6/2013 | Cleanup Action Plan |
Feasibility Study & Disproportionate Cost Analysis: North Colfax Petroleum Contamination Site | 3/16/2012 | Feasibility Study |
Remedial Investigation Report Addendum: North Colfax Petroleum Contamination Site: | 3/16/2012 | Remedial Investigation Report |
Remedial Investigation Report: North Colfax Petroleum Site | 1/4/2010 | Remedial Investigation Report |
Site Hazard Assessment: Food Mart 041 | 8/22/2007 | Site Hazard Assessment Report |
Site Hazard Assessment: North Colfax Petroleum Contamination | 8/10/2007 | Site Hazard Assessment Report |
Places to see print documents
-
Eastern Regional OfficeN 4601 Monroe StSpokane, 99205-1265Please schedule an appointment to view print documents at this location.
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Whitman County Library102 S MainColfax, 99111This location may only have print documents available during open comment periods.
Contaminants 6
Contaminant Type | Soil |
Groundwater |
Surface Water |
Air |
Sediment |
Bedrock |
---|---|---|---|---|---|---|
Non-Halogenated Organics - Methyl tertiary-butyl ether | C | C | ||||
Metals - Lead | B | B | ||||
Non-Halogenated Organics - Benzene | C | C | ||||
Non-Halogenated Organics - Petroleum-Diesel | C | C | ||||
Non-Halogenated Organics - Petroleum-Gasoline | C | C | ||||
Non-Halogenated Organics - Petroleum-Other | C | C |
- S
- Suspected
- C
- Confirmed Above Cleanup Levels
- B
- Below Cleanup Levels
- RA
- Remediated-Above
- RB
- Remediated-Below
- R
- Remediated