Former Rocket and Jet Engine Testing Facility Remediation

(Boardman, OR)  Landau Associates provided environmental consulting services at a former engine test facility (ETF) near Boardman, Oregon from 1999 through receipt of a No Further Action (NFA) determination in 2012. The 600-acre former ETF was used for liquid-fuel rocket engine testing between 1963 and 1965, and for jet engine ground testing into the 1980s. Site facilities included several engine test stands, pads, and support infrastructure (buildings, underground fuel piping, a septic tank, and roads). The site was an area of approximately 93,000 acres, including the ETF, which had been leased from the State of Oregon and subleased to several farming ventures. Landau Associates assisted with the sale of lease rights to another entity including investigation of the ETF and other sites within the larger lease area.

Landau Associates performed environmental investigations, remediation, and risk assessment at the site under the Oregon Voluntary Cleanup Program. Fuel piping, asbestos materials, septic sludge, and petroleum-impacted soils were removed from the ETF. ETF site investigation included groundwater, surface water, soil, and soil vapor sampling, which indicated that trichloroethene (TCE) and perchlorate were contaminants of concern. Our investigation demonstrated that TCE was present within suprabasalt groundwater extending over approximately 50 acres. We combined extensive sampling of perchlorate in various surface water bodies within 10 miles of the Site and other regional studies to demonstrate that perchlorate was regionally distributed and not associated with site activities.

Landau Associates performed a risk assessment that demonstrated that TCE present in site groundwater posed no unacceptable risk to human or ecological receptors. TCE was not present in the deeper water-bearing zone used by nearby water supply wells, and the shallow and intermediate water-bearing zones are not used due to typically poor water quality and yields. Landau Associates performed a human health risk assessment that demonstrated that TCE concentrations at the site were protective of human health for all exposure scenarios, with the exception of potentially unacceptable risk from indoor air exposure within potential future buildings. We also performed sub-slab vapor sampling beneath existing slabs at the site to evaluate the potential risk, with results demonstrating no unacceptable risk to indoor air. With no TCE present in shallow soil or surface water, a Level 1 Ecological Risk Assessment demonstrated no complete exposure pathways for ecological receptors. As a result of these assessments, we successfully negotiated a determination of No Further Action with Oregon Department of Environmental Quality (DEQ), based on our demonstration of no unacceptable risk to human health and the environment.

Although DEQ accepted that there was no unacceptable risk at the site that would require treatment of groundwater, our client voluntarily elected to perform treatment of the highest concentration portions of the plume using in situ chemical oxidation (ISCO). Landau Associates designed an ISCO treatment using three infiltration trenches backfilled with a mixture of potassium permanganate powder and sand, perforated piping, and drain rock. Water pumped into the trenches dissolved emplaced permanganate resulting in infiltration of oxidant solution to groundwater. Treatment effects observed in the vicinity of the ISCO trenches included purple water characteristic of permanganate solution and TCE concentration reduction.