The 32 acre site is currently owned by Klamath County, which acquired it through tax foreclosure in 1998. The Chiloquin Lumber and Box Company operated a box factory and lumber mill on the Site starting in 1918. The box factory burned down in 1947 but the lumber mill remained operational until 1988. The last operator of the mill was Chiloquin Forest Products, Inc. which filed for bankruptcy in 1991. US Bank liquidated the company’s assets in 1993 but did not foreclose on the real property. Klamath County foreclosed on the real property on September 28, 1998.
Historic operations included lumber milling and finishing, chemical storage, equipment maintenance and vehicle fueling. A log pond was created in the northwest portion of the property (where the box factory and housing were located). Between 1968 and 1983, the log pond was filled to become a log deck for the mill. The area where the log deck existed currently consists of degraded wood waste averaging one to two feet deep and covering 6.5 acres on the west side of the Site.
Three sampling events by the Oregon Department of Environmental Quality (ODEQ) in 2005 showed evidence of widespread contamination of the surface and subsurface soil with dioxins and furans with concentrations ranging from 1.5 to 2,629 ng/kg dioxin Toxicity Equivalent Concentration (TEC).
ODEQ performed a Preliminary Assessment in 1992, a Removal Assessment in 1996, a Targeted Brownfields Assessment in 2002 and a Supplemental Targeted Brownfields Assessment in 2003. ODEQ, on behalf of Klamath County, performed Brownfields funded cleanup activities in April 2005 that included abating asbestos-containing materials (ACM) from a boiler house, demolishing the boiler house, and removing soils contaminated with pentachlorophenol (PCP), dioxin, and petroleum hydrocarbons. Cleanup activities were successful in addressing PCP, ACM, and petroleum contamination. Post-cleanup sampling, however, indicated that dioxin was still present in the soils. Several phases of subsequent sampling and dioxin analysis showed that there remained elevated dioxin concentrations in surface soils around the former PCP excavation (presumably associated with use of PCP at the former mill Site), but also in presumed background samples obtained from other locations on the Site. The cleanup operation was halted until a plan could be developed to address the dioxin contamination.
In May 2006, ODEQ conducted dioxin delineation activities to understand the origin and extent of dioxin contamination on and off the Site. Soil samples were collected on public lands, from unassessed areas of the Site, adjacent properties (including the school and residential properties), other urban areas of Chiloquin, and the surrounding vicinity. Dioxin concentrations were highest in surface soil in the area of the former PCP excavation. On-site concentrations will be addressed as part of this Removal Action for dioxin contamination at the former mill property where concentrations are the highest.
EPA proposes capping the dioxin-contaminated soil with clean material (stock piled on-site by the Oregon Department of Transportation) and recording a deed restriction and easement on the property to ensure that the long-term integrity of the remedy remains protective. This action will contain the dioxin contamination and prevent it from threatening human health and the environment. Existing on-site wood waste will be incorporated into the surface of the cap to improve growing conditions for the grass that will be planted on the surface after capping. This proposed action requires no off-site disposal of hazardous waste.
On May 18, 2007 EPA Region 10 approved the following removal action with primary tasks to include:
1.Securing the Site by installing a gate and fence;
2.Site clearing and demolition work including breaking of asphalt pavement and removal of railroad ties;
3.Soil cap construction consisting of spreading and compacting soil from existing soil stockpile on the Site;
4.Spreading and incorporating wood waste from the former log deck area into the surface of the soil cap.
The Site will be secured to prevent illegal dumping, vandalism, and trespassing. This will consist of installing a heavy duty gate at the northern access point and blocking off the southern access point.
Once the proposed removal action is completed, the dioxin on-site will no longer pose a threat to human health or the environment because it will be contained under sixteen inches of clean material and a layer of vegetation. Future development of the Site will require compliance with the identified cap management practices associated with a deed restriction and easement that Klamath County and ODEQ will implement.
The selected alternative can be implemented quickly. The materials are already on-site to build the cap and no further Site characterization is required. EPA will rely on data collected by ODEQ in 2006 for delineation of the dioxin contamination. This data is available in the Administrative Record. The only identified potential adverse impact associated with the intermediate steps of this proposed action is the migration of contamination due to construction activities. Keeping soils moist during on-site work will minimize the potential for wind to carry the disturbed dirt.
To protect the endangered aquatic species, no soil movement activities or vehicles will operate within the fifty foot buffer along the Sprague River. Temporary erosion and sediment controls in combination with the fifty foot buffer along the river will mitigate the potential for runoff to carry the disturbed, dioxin-contaminated soil to the river while construction activities are occurring.
The Removal Action Memo was signed by the EPA Region 10 Environmental Cleanup Division Director on 5/18/2007. Since the Removal Action proposal was for an action level lower than the EPA limit of 1000 ppb, EPA Headquarters approval was required. Approval was granted on 6/14/2007.
EPA site work is expected to start in early July 2007 and finish in August 2007
The administrative record is available to the public at the EPA Region 10 Superfund Records Center, 1200 6th AVe., Seattle, WA 98101 and near the site at the Chiloquin Library, Chiloquin, Oregon 97624, 541-783-3315.
