1.1.1 Incident Category

Time Critical Removal Action

1.1.2 Site Description

The Valley Post and Sawmill site (Site) is a former sawmill and wood treatment facility located along the south side of Big Goose Road approximately 2 miles south west of Sheridan, Sheridan County, Wyoming.  The Valley Post and Sawmill treated wood using Pentachlorophenol (PCP) mixed with diesel fuel.  It is unknown precisely when the facility commenced its wood treating operation; however, the state of Wyoming believes that it shut down sometime during 1996.

Carl Sayer owned and operated the Valley Post and Sawmill during the entire period of operation.  PCP was mixed with diesel fuel in a small tank, after which, it was transferred to the retort tank/pressure vessel where the posts were treated.  In addition to the retort vessel, there were also two smaller tanks that posts were dipped in to be treated.  Treated posts were then stacked on bare soil to dry.  There is no record of any containment features associated with Site operations, and the use of engineered containment features was not a standard practice in the industry prior to the mid to late 1980s.

The Wyoming Department of Environmental Quality (WDEQ) and EPA’s Resource Conservation and Recovery Act (RCRA) programs conducted an inspection of the facility while it was in operation in 1987.  The inspection documented areas of significant soil contamination and dumping of PCP laden solution directly to soil, however, at the time of the inspection, the F032 waste listing had not been promulgated, so no actions were taken.  Results of this inspection are available in the Site file.  There is no evidence that either EPA or DEQ followed up on this inspection. 

In October of 2008, WDEQ responded to an inquiry about the facility from a prospective purchaser and conducted an inspection.  This inspection identified that the tanks and equipment had been removed from the Site and that significant movement of soil had occurred recently.  A cure notice was issued to the current property owner, Mr. Shane Taylor – Carl Sayer’s nephew, to conduct an assessment of the property and to develop a clean up plan.  Taylor was given 60 days to respond.  WDEQ requested EPA’s assistance for the Valley Post and Sawmill Site upon the expiration of the 60 day time period, on approximately May 15, 2009.

The Site is an inactive 25 acre sawmill and wood treating facility consisting of several areas of contaminated soil where wood treatment, dipping, and drying occurred.  The Site as not been used for wood treatment since approximately 1996.  The site also includes a parcel of property located in Guernsey, WY, where Mr. Taylor moved the aforementioned tanks.

1.1.2.1 Location
 

650 West Wheatland Ave, Guernsey, WY; and
446 Big Goose Road, Sheridan, WY

1.1.2.2 Description of Threat

PCP has been documented at the Site in concentrations exceeding 390 mg/kg, indicating that PCP has been released into the environment.  Documents from the joint EPA/WDEQ inspection show very poor housekeeping during facility operations and support the Removal Site Evaluation findings of PCP in the soils on the Site.

PCP has been documented in concentrations exceeding 8,000 mg/kg in the tank at the Guernsey Property.  This tank has also been documented to have existing holes, thus threatening a release of listed hazardous waste to the environment.

1.1.3 Preliminary Removal Assessment/Removal Site Inspection Results
 
In March 2009, a removal site evaluation was initiated after WDEQ requested EPA’s assistance to assess two tanks that were taken from the Valley Post and Sawmill which were currently located at the property in Guernsey, WY.  OSC Steven Merritt accompanied the Superfund Technical Assistance Response Team (START3) contractor team to the Site on March 25, 2009.
 

Upon arrival, the team found two tanks on a semi trailer.  The trailer showed slight staining near the rear tank, indicating a small amount of leakage during transport.  The rear tank, the retort tank, was found to contain metal apparatus used to hold posts in the tank while being treated, several wood posts, and a layer of black sludge that had apparently settled to the bottom of the tank.  This sludge was sampled and, upon laboratory analysis, determined to contain 8,600 mg/kg Pentachlorophenol (PCP).  The front tank was apparently empty and not able to be sampled for reasons outlined in the START3 Trip Report dated April 24, 2009.  Both tanks had what appeared to be small holes drilled in them near the bottom. 

In May, 2009, the OSC elected to conduct a Removal Site Assessment at the Valley Post and Sawmill facility.  The objective of the Removal Site Assessment was to identify if a release of hazardous substances had occurred, as well as to begin delineation of said release if at all possible.

On June 8, 2009, OSC Myers accompanied the START3 team to the Site.  OSC Myers discussed the investigation with Mr. Shane Taylor.  The START3 team collected numerous surface and subsurface samples, predominantly from areas where inspection records suggested process equipment had been located as well as where soil discoloration and/or odors were present.  Two ground water wells were attempted, with only one yielding enough water to obtain a sample.  The START3 team also collected composite samples from areas that would have been amenable to stacking and drying wood in hopes of locating additional areas of contamination.

A second round of sampling was conducted between September 21^st and September 24^th to delineate the additional area(s) of contamination that were identified/delineated during the June event.  EPA mobilized the START3 team and EPA’s mobile laboratory to the Site for this event to ensure that the additional areas were fully delineated prior to demobilization.  Sample results are available in the Sampling Activities Report in the Administrative Record for the Site.  

Analytical results of the aforementioned collected samples indicate significant levels of PCP and diesel fuel in the surface and subsurface soils at the Site, with the highest concentration detected being 16,424 ug/g (mg/kg) in a sample of highly stained soil in the former drip area.  The highest average concentration detected on the sample grid was 390 mg/kg near the location where the WDEQ documented drum storage and significant spillage in their June 1987 inspection (photo 36).  Sample results also indicated that two of the areas sampled had PCP present even though there was no discoloration or odor noted at the time of sampling.

EPA Region 8 commissioned The Environmental Response Team (ERT) out of Edison, NJ to conduct biological prospecting and a treatability study to determine if augmented biological treatment would be a viable option on this Site.  ERT located a strain of bacteria from the samples taken in September that is very aggressive at breaking down PCP in soil; it degraded approximately 100 parts per million PCP in 4 days with very low chloride production.