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Environmental Cleanup Site Information (ECSI) Database Site Summary Report - Details for Site ID 1657, Black Butte Mine

This report shows data entered as of August 8, 2022 at 6:15:27 PM

This report contains site details, organized into the following sections: 1) Site Photos (appears only if the site has photos); 2) General Site Information; 3) Site Characteristics; 4) Substance Contamination Information; 5) Investigative, Remedial and Administrative Actions; and 6) Site Environmental Controls (i.e., institutional or engineering controls; appears only if DEQ has applied one or more such controls to the site).  A key to certain acronyms and terms used in the report appears at the bottom of the page.

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Environmental Cleanup Site Information (ECSI) Database Site Summary Report - Details for Site ID 1657, Black Butte Mine

Site Photos
Click to View Photo Picture Date Caption Size
View Photo 06/24/2004 Primary waste tailings pile. 113 Kb
View Photo 06/24/2004 Upper portion of "new" rotary kiln furnace, located above Dennis Creek. 105 Kb

General Site Information

Site ID: 1657 Site Name: Black Butte Mine CERCLIS No: 0000515759
Address: London Rd. (approx. 15 miles S of Cottage Grove)  
  County: Lane Region: Western
Other location information: Black Butte Mine is located in T23S/R3W/s16. The tailings area (Mine Dump) is primarily in Section 8. The lat/long is for the tailings.
Investigation Status: Listed on CRL or Inventory
Brownfield Site: No NPL Site: Yes Orphan Site: Yes Study Area: No
Property: Twnshp/Range/Sect: 23S , 3W , 8 Tax Lots:
  Latitude: 43.5793 deg. Longitude: -123.0679 deg.  Site Size:
Other Site Names:

Site Characteristics

General Site Description:
Site History: Black Butte Mine was one of the largest mercury mines in Oregon. It was developed in the late 1890s and operated under various owners until its final closure in the late 1960s. The mine was the fourth largest producing mercury mine in Oregon. Two furnace locations are present within the mill site. One is above the main tailings pile above Dennis Creek. The other is located adjacent to Furnace Creek and was in operation from the 1890s to the 1930s. Soil near the Furnace Creek furnace has the highest mercury concentrations at the site.
Contamination Information: (2/25/2003 GA/SRS) DEQ completed a Preliminary Assessment of the site in 1996. Approximately 300,000 cubic yards of mine tailings were identified at the site, within 30 feet of Dennis Creek. EPA conducted a Site Investigation at the mine in 1998. Mercury was detected at 48 ppm in sediment from Dennis Creek directly below the tailings pile. Arsenic was detected in several nearby domestic wells, including an upgradient well. Both arsenic and mercury were found in site soils and in the tailings pile.

(6/16/04 BT/SRS) DEQ and OSU completed a mercury reconnaissance assessment. 99 shallow soil samples were collected from locations in a radial grid pattern extending to a 1.5-mile radius from the mill site. The objective was to determine what impact, if any, historical vapor releases may have had on the surrounding watershed. Soil samples near the furnaces within the mill site had total mercury up to 2,090 mg/Kg. Soil samples in the general area around the mill site, including tailings, had total mercury between 10 and 100 mg/Kg. Soil samples from the Dennis Creek and Furnace Creek watersheds had total mercury between 0.1 and 10 mg/Kg, with a few samples up to 200 mg/Kg.
Manner and Time of Release: Past operating practices; tailings piles exposed to erosion, leading to sediment transport from site and downstream.
Hazardous Substances/Waste Types: Arsenic, mercury
Pathways: Although soil contamination has been documented, because of the site's remote location, direct contact is not considered significant. Surface water impacts appear to be potentially significant, with mercury migration resulting in widespread downstream contamination in Dennis and Garoutte Creeks, the Coast Fork of the Willamette River, and Cottage Grove Reservoir.
Environmental/Health Threats: Studies conducted by Oregon State University in 1990 found up to 1.8 ppm mercury in fish tissue in Cottage Grove Reservoir, and up to 1.1 ppm mercury in reservoir sediments. Black Butte Mine is upstream of the reservoir and is a potential source of the mercury contamination. In addition, arsenic has been found in domestic wells near the mine.
Status of Investigative or Remedial Action: (2/25/2003 GA/SRS) The site has been owned by the Land and Timber Company since 1994. However, Land and Timber has stated that since they did not operate the mine, they are unwilling to conduct an investigation or cleanup. Other potentially responsible parties, such as the mine operators, are no longer viable. DEQ designated Black Butte Mine as an Orphan Site in August 2002. DEQ plans to investigate and clean up the site as funding becomes available.

(6/15/04 BET/SRS) Conceptual scope for a removal assessment completed in May for funding proposals. Removal assessment anticipated to be initiated in late summer 2004.

(2/15/05 BET/SRS) EPA funding for a removal assessment was granted in December 2004. Removal assessment workplan anticipated to be complete in spring 2005 and assessment work to be conducted in Summer 2005.

(12/06 BET) EPA removal assessment conducted 9/05. Removal of soil as well as sloping and vegetation of exposed soil is planned for Spring 2007. EPA to conduct removal July of 07.
Data Sources: US EPA Site Investigation Report 4/99

OSU/DEQ Hg Recon Assessment Draft Report 4/31/04

Substance Contamination Information

Substance Media Contaminated Concentration Level Date Recorded
ARSENIC Soil 114 - 952 mg/kg  
CHROMIUM Soil 95 - 858 mg/kg  
MERCURY Sediment 148 - 54,300 mg/kg  
MERCURY Soil 148 - 54,300 mg/kg  
VANADIUM Soil 184 - 682 mg/kg  
ZINC Soil 454 - 2,330 mg/kg  

Investigative, Remedial and Administrative Actions

Action Start Date Compl. Date Resp. Staff Lead Pgm
REMEDIAL INVESTIGATION  (Primary Action) 09/05/2010   Bryn Thoms SRS
View Full Report Showing Action History

Key to Certain Acronyms and Terms in this Report:

You may be able to obtain more information about this site by contacting Bryn Thoms at the Western regional office or via email at If this does not work, you may contact Ximena Cruz Cuevas (503) 229-6811, or via email at or contact the Western regional office.