Download Hoffman Construction strategy recommendation (April 1994)

DEQ SITE ASSESSMENT PROGRAM - STRATEGY RECOMMENDATION
Site Name: Hoffman Construction Co.
site CERCLIS Number: none
DEQ ECSI Number: 1522
Site Address: 8027 NE Killingsworth St.
Portland, OR 97218
Recommendation By: Gil Wistar, Voluntary Cleanup and site
Assessment Section, DEQ Northwest Region
Approved By: Michael E. Rosen, Manager, Voluntary
Cleanup and Site Assessment Section, DEQ
Northwest Region
Date: April 12, 1994
Background: Not much is known about Hoffman Construction Co.
(Hoffman), except that the site is active and has been in operation
since at least 1973. Hoffman uses the site to store, maintain, and
repair equipment employed in its commercial and industrial
construction business.
In late 1988, Hoffman decided to· remove its four underground
storage tanks, under contract to Pegasus Waste Management, Inc.
These four tanks contained gasoline, diesel, kerosene, and waste
oil, respectively. Pegasus removed the four tanks in January 1989,
and none except the 8,000-gallon waste oil tank appeared to have
caused significant contamination.
Although the waste oil tank
showed no evidence of holes or leakage, there was obvious soil
contamination in the pit, which was attributed to overfilling or
surface spillage.
A sample of oil from the tank contained 1,320
ppm 1,1,1-trichloroethane (TCA)
and 1,200 ppm PCB,
so DEQ
apparently required disposal of the tank at a Class I landfill, and
disposal of contaminated soil from around the tank at an
"acceptable" facility. (This information is taken from the Pegasus
report; there is no file documentation of such DEQ directives.)
Upon discovery of contaminated soil in the pit, Pegasus submitted
a sample of the soil for analysis.
According to the 1/18/89 lab
report, this sample contained 6 ppm PCB (Aroclor 1248), as well as
methylene chloride, TCE, and perchloroethylene (PCE).
(This lab
report used EPA Method 450.1 (total organic halogens) to derive
these results, and found 67.9 ppm organic halogens; the quantities
of methylene chloride, TCE, and PCE were not specified.) Based on
1
these
results,
Pegasus
prepared
a
detailed
sampling
and
investigation plan, which focused on PCBs.
It is unknown whether
this plan was implemented; there are no records in the file to
suggest that it was carried out.
In February 1989, Spencer Environmental Services collected an
additional soil sample from the bottom of the tank pit, and an
additional sample of the waste oil itself. The soil sample, taken
from an area of discoloration, contained 2,025 ppm total halogens,
22 ppm Aroclor 1248, and 28,665 ppm oil-range hydrocarbons.
The
waste oil sample contained 2,274 ppm total halogens, 85 ppm Aroclor
1~48, and 310 ppm total lead.
After excavating more soil from the
pit, to a depth. of about 20 feet, a bottom sample contained 346 ppm
total halogens, 0.37 ppm Aroclor 1254 (not 1248), and 270 ppm oil.
In March 1989, Spencer installed two test borings near the tank pit
to obtain more information on the extent of contamination.
Test
hole 1 was located 1.5 feet from the northeast corner of the pit,
and test hole 2, 16 feet north of the pit. Analytical results are
shown l:>elow.
CONSTITUENT
!EPA Method 9020)
TEST
HOLE 1,
20 ft.
TEST
HOLE 1,
25ft.
TEST
HOLE2,
20ft.
TEST
HOLE2,
25ft.
TEST
HOLE2,
30ft.
Total halogens, ppm
167.5
157
223
1,701
271
Organic halogens,
ppm
115
107
208
1,686*
255**
Inorganic halogens,
ppm
52.5
50
15
15
16
*
**
Identified by lab report as 1,1,1-trichloroethane (TCA).
Identified by lab report as chloroform.
In the meantime, about 45 yards.of contaminated soil from the pit
were stockpiled on site, and Hoffman Construction applied through
Metro to dispose of the soil at st. John's Landfill in North
Portland.
After consulting with DEQ, Metro requested additional
profiling on the soil as a condition of accepting the application.
Then, in July 1989, Metro .denied the application, after learning
that Hoffman had already returned the soil to the pit and filled
the hole to grade.
DEQ's Leaking Underground Storage Tank (LUST) section closed site
file #26-89-005 on July 10, 1989, indicating in its closure letter
to Hoffman that no further action was needed with respect to the
former gasoline, diesel, and kerosene tanks. LUST had previously
referred the waste oil tank contamination to DEQ's Environmental
Cleanup Division (ECD), and indicated in the letter that the
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situation warranted further action, under ECD oversight.
It
appears that ECD was consulted about the site, but did not take an
active role in follow-up.
In a March 28, 1989 E-mail to Loren
Garner of LUST, Paul Burnet of ECD made the following points:
1) If the source of the halogens were a pre-1973 spill (the
facility had indicated that it had not used chlorinated solvents
since 1973), extensive offsite migration may have occurred, and
high soil levels at depth were "not a good sign."
2) Chlorinated solvents like TCE typically will not leave much of
a trace as they pass through soil, indicating that much higher
concentrations of halogens might be found at greater ·depths or
further downgradient.
3) The water table had not been located, so that it was not known
whether groundwater had been affected.
4) TCE levels in soil were orders of magnitude above the federal
drinking water.standard of 5 ~gfL.
Despite these concerns, the only evidence of ECD action at the site
is a June 27, 1989 letter to Cecil Drinkward, President of Hoffman
Construction, in which ECD recommends that Hoffman initiate site
cleanup.
Site Assessment considers groundwater to be the most threatened
exposure pathway at this site.
This is because the depth of
documented contamination makes the other three pathways unlikely to
be affected. In addition, the site is located at the western edge
of the Portland Water Bureau (PWB's) Columbia South Shore Planning
Area (see attached map), where most of the city's backup drinking
water wells are located.
Although PWB is not currently drawing
water from these wells, it is likely that they will be needed in
the near future due to population growth and the unpredictability
of surface water supplies.
Specifically, the Hoffman site is 1.5 miles west of the nearest PWB
production well, #29, which is screened in deep Troutdale aquifers.
The site is also located 1.5 miles northwest of Parkrose #1, a
backup well now owned by PWB that is screened in shallower,
unconfined water-bearing zones. In addition, Bible Temple School
maintains an active drinking water well between 1 and 1.25 miles
southeast of the site;. it serves up to 2, 400 persons (Sunday
worship). The depth of this well is unknown, as is the direction
of local groundwater flow.
References: site Assessment has reviewed the following sources in
preparation of the background information above:
A copy
of
a
report
entitled Underground
3
Fuel
Storage. Tank
Removals and Site Remediation
Final Report,
Pegasus Waste Management, Inc. (undated).
prepared
by
An application to dispose of special wastes, filed at Metro,
which includes lab results from an investigation conducted by
Spencer Environmental Services.
Notes and correspondence from the LUST file.
Significant concentrations of chlorinated
hydrocarbons have been documented in soil below depths of 25 feet
at this site. With respect to soil, this contamination may extend
to much greater depths and may have migrated off-site. Groundwater
may also be contaminated, particularly in light of Hoffman's having
apparently backfilled the former waste oil pit with contaminated
excavation spoils in 1989. Due to the site's location on the edge
of the Columbia South Shore Wellfield area, the types and
concentrations of contaminants found, and the unknown extent of
chlorinated hydrocarbons, Site Assessment recommends further action
at the Hoffman site, under high priority.
The owner/operator
should characterize soils on-site (and off-site as necessary) with
respect to types and extent of PCBs and chlorinated solvents. At
the same time, a groundwater investigation should be conducted to
determine impacts to groundwater and to assess the potential damage
to local drinking water supplies ..
Recommendation/Action:
In addition, this site should be added to the Confirmed Release
List and Confirmed Release Inventory.
Referrals Within or outside DEQ: This site has not been referred to
another division of DEQ or to an outside regulatory agency. DEQ's
LUST section referred the site to DEQ' s Environmental Cleanup
Division in 1989.
Other: This site is currently listed on DEQ's ECSI database; it
will be updated with information contained in this decision
document, and to reflect Site Assessment's decision for further
action at the site.
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coNS<f'f'-VC\ION
COLUMBIA SOUTH SHORE
LEGEND
COLUMBIA SOUTH
SHORE BOUNDARY
BLA
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SGA
+
~
TSA
)I(
CRSA+
SCALE
1000
0
1000 2000 3000
FEET
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--~-----~·-
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--·-~--~------
SITE PRIORITIZATION WORKSHEET
Site Name:
·~ c~ Co.,
Medium of Concern:
~
H
M
L
NA
1. Substance Characteristics:
A. Toxicity/Persistence:
B. Mobility:
X
X
.X
2. Contamination Route:
3. Vulnerable Targets:
.. A.
Population
Affected~
X
-
X
B. Sensitive Environments/Species:
4. Verification of Release/Threatened Release:
5. Quantity/Concentration of Substance:
6. Environmental Effects on Release Control:
Overall Site Priority:
X
X.
X
X
Comments:
Evaluator: __
~~~~-~~----~---·--~--~----~-----------
Date:
~
NOTE:
Under no circumstances can a documented release above action levels be
NFA'd without additional assessment and/or sufficient supporting documentation.