Report • �• NEC 02005 -ooh i 3
Envir onto
SeNice , Inc.
May 2, 2005
RE: Soil and Groundwater Cleanup Proposal for the Leaking Heating Oil Underground Storage
Tank located at 11330 SW 90 Ave.
Soil and groundwater sampling conducted by Soil Solutions revealed elevated diesel range petroleum
hydrocarbons adjacent to the residential underground heating oil storage tank located at the above
referenced address. On March 17, 2005 representatives of Soil Solutions collected soil samples under
the tank that revealed high levels of contamination. On April 4 the tank was decommissioned and
parts of the tank were removed. Approximately 1.3 tons of contaminated soil were removed. Because
contamination was still in place, a risk based solution was provided. A soil boring was made in an
attempt to determine the vertical extent of the contamination. Groundwater was encountered in the
soil boring at approximately 12 feet below the ground surface. A water sample was collected and
analyzed for BTEX, NW- TPHDx, and PAIL The concentrations are higher than the maximum
allowable concentrations to be left on site. Soil Solutions anticipates that additional groundwater
sampling will be required to assess the extent of the groundwater contamination. The DEQ requires
the contamination in the groundwater be defined by completing one soil boring upgradient and two
soil borings downgradient of the contamination plume. A water sample and a soil sample will be
analyzed from each boring. If TPH and BTEX levels are below the DEQ acceptable limits, the release
file can be closed. If contamination exceeding acceptable levels extends beyond our borings,
additional borings will be required.
Soil Solutions Environmental Services Inc. (SSES) will outline the tasks and estimated costs below to
conduct soil and groundwater investigation at the above - referenced property.
Soil and groundwater analytical data obtained from this investigation will be evaluated by SSES to
determine if additional site activities are necessary in order to satisfy Oregon Department of
Environmental Quality (DEQ) requirements. The probable costs to complete the proposed soil and
groundwater investigation are summarized below.
64 0
P.O. Box 15102 Portland, OR 97293 • 503.234.2118 • Fax 503. 31.7133
CCB# 138344 WA# SOILS* *995NM