Brownfield Assessment of the Benton Auto Wreckers Site,

Corvallis, Oregon

Project Overview

Under a Cooperative Agreement with EPA Region 10, the Site Assessment Program of the
Oregon Department of Environmental Quality (DEQ) conducted a Brownfield Assessment at the
4-acre Benton Auto Wreckers site, located several miles southwest of the City of Corvallis on
State Highway 20 in Benton County, Oregon (see map below). In June 1997, Benton County
asked DEQ and EPA to expand on previous investigations of this former auto wrecking yard that
had suggested the presence of contamination at levels of concern. The County believed that
further knowledge about the extent and magnitude of contamination would facilitate the
property's sale and redevelopment. DEQ completed its assessment in August 1998 at no cost to
the county, and concluded that contaminants in surface and near-surface soils warrant further
assessment that may lead to remedial action.

DEQ completed the assessment in the third year of a Brownfield Pilot Project funded by EPA.
The pilot is designed to determine the demand for, and potential effectiveness of, an expanded
Brownfield evaluation program and to assist local redevelopment efforts. (Brownfields are
usually defined as vacant or under-utilized commercial/industrial sites with known or perceived
contamination that has affected their sale or redevelopment.)

Site Background

Apparently, a slaughter yard originally occupied the site. In the early 1950s, the site was
converted to an auto wrecking facility, a use that continued until 1991, when Benton County
acquired the property through tax foreclosure. Junkyard operations during this period included

-------
vehicle service, repair, and painting. Transients may at times have occupied the property after the
wrecking yard went out of business; otherwise, the site has been vacant since 1991.

Benton County began environmental investigations of the site in 1992, after a consultant noted
significant areas of soil staining throughout the facility, found abandoned solvent and oil storage
containers (which were removed from the site in 1993), and documented an out-of-service
underground storage tank (UST). Soil samples collected in 1992 showed elevated concentrations
of many contaminants, but petroleum hydrocarbons and arsenic were the primary contaminants of
concern. Sampling in 1994 also showed the presence of lead at very high levels in paint chips
around several site buildings. These previous investigations turned up the presence of an
abandoned water-supply well within the main shop building on-site; its former use is unknown.

What We Did

The project began with a scoping meeting in July 1997, attended by representatives of Benton
County, DEQ, the Oregon Economic Development Department, and EPA Region 10. In
December 1997, DEQ conducted a geophysical survey of near-surface debris that was suspected
of being present. No buried objects considered hazardous were found. In May 1998, after this
low-lying site dried out, DEQ returned to the site to collect 33 surface soil samples distributed in
a grid over the entire site (including a background sample); seven soil samples from depths of
between 1 and 2 feet in areas where 1992 sampling had shown elevated contaminants; a soil
sample from a depth of 8 feet near the abandoned UST; and a groundwater sample from the on-
site well.

What We Found

Soil samples were analyzed by EPA Contract Laboratories for a wide range of constituents.
Surface samples contained certain polynuclear aromatic hydrocarbons (PAHs), as well as arsenic
and lead, above levels of concern; one of the surface samples contained elevated polychlorinated
biphenyl (PCB) levels. Several subsurface samples also contained elevated levels of arsenic and
lead. DEQ attributed detections of beryllium in soil to background conditions. The groundwater
sample did not contain any metals above EPA drinking water standards.

The Next Steps

As noted previously, Benton County is interested in the sale and redevelopment of this property.
Before redevelopment occurs, DEQ recommends a remedial investigation and feasibility study
(RI/FS) targeted at PAH, PCB, arsenic, and lead levels in surface and shallow subsurface soils.
DEQ also recommends the decommissioning of the abandoned UST and the on-site well. Further
evaluation of groundwater does not appear to be necessary.

For more information or for a copy of the Brownfield Assessment report, contact:

Mary Otley, Benton County: (541) 757-6767, or
Gil Wistar, Oregon DEQ - Portland: (503) 229-5512

-------