Record of Decision Remedial Alternative Selection Toftdahl Drums Brush Prairie Clark County Washington


RECORD OF DECISION
REMEDIAL ALTERNATIVE SELECTION

Site: Toftdahl Drums, Brush Prairie, Clark County, Washington

Documents Reviewed	>"

I am basing my decision primarily on the following documents
describing the Toftdahl Drums site.

-	Final Report Remedial Investigation for the Toftdahl Drpm
Site. July 17, 1986

-	Summary of Remedial Alternative Selection. Toftdahl Drum
Site. August 1986

-	Responsiveness Summary dated September 22, 1986
Description of Selected Remedy

-	No further action to remediate the site

-	Sample and analyze groundwater samples from existing
monitoring wells and private residential wells semi-annually
for five years, and then annually for ten additional "years,
subject to funding by the Washington State Legislature.

Declarations

Consistent with the Comprehensive Environmental Response,
Compensation and Liability Act of 1980 (CERCLA), and the National
Contingency Plan (40 CFR Part 300), I have determined that the
"no further action" alternative combined with precautionary *
monitoring of the groundwater by sampling the existing monitoring
and private residential wells on or near the site is the
appropriate remedy for the Toftdahl Drums site. Because of the
lack of significant contamination at the site, and the lack of
evidence that contamiantion has migrated from the site, these
measures are adequate to protect public health, welfare, and the
environment. The Washington Department of Ecology (Ecology) has
been consulted and agrees with this remedy. Ecology has also
agreed to undertake the precautionary monitoring.

I have also determined that the action being taken is
appropriate when balanced against the availability of Trust Fund
monies for use at other sites. The "No Further Action"

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EPA/ROD/R10-86/Q09
Toftdahl Drums, WA

16. ABSTRACT (continued)

the site, conducted an investigation. Approximately six crushed and badly
rusted drums were sampled and stored onsite and a fence was placed around
the final drum burial area. In November 1983 the Washington Department of
Social and Health Services (DSHS) determined, based on the available
sampling data from nearby residential wells, there was no immediate public
health hazard in the drinking water. However, DSHS was concerned about the
£K3tential for future contamination from the high levels of heavy metals and
synthetic organic compounds detected in the soil and drum samples. While
several priority pollutants were detected in the RI sampling and analysis
program, the concentration of such contamination is very small and could
reflect a source(s) not related to this particular drum cleaning and
disposal operation. In most sampling cases, the concentration levels could
not be reliably differentiated from background values or
laboratory-introduced variability. No significant or extensive
contamination of surface soils, surface water, or ground water is present at
the site. Indicator constituents, defined as having been detected at"least
one time during investigational sampling include: heavy metals, VOCs,
base-neutral organic compounds, cyanides, and PCBs.

The remedial action selected for this site includies a no further action
response and semi-annual ground water monitoring for five years, followed by
ten years of annual monitoring pending continued funding by the Washington
State Legislature.

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alternative in conjunction ^ith
adequately protect public healtl

Date

groundwater
llfare, an

monitoring will
environment.

lobie <3. Rus s<

Regional Administrator
EPA Region 10

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SUMMARY OF REMEDIAL ALTERNATIVE SELECTION
TOFTDAHL DRUM SITE
BRUSH PRAIRIE, CLARK COUNTY/ WASHINGTON

Sits. Location aM Description

The Toftdahl Drum site is approximately 15 acres situated
approximately 4 miles east-southeast of Battleground, Washington.
(See Figure 1.) The site lies on a considerably dissected,
irregular, rolling upland section of the Troutdale bench, a
north-south trending feature about 2 miles wide situated between
the Cascade foothills to the east and a broad alluvial plain to
the west.

The three main areas of the site where hazardous substance
handling activities may have occurred are a drum cleaning area,
an initial burial trench, and a final drum burial area. (See
figure 2) These areas are situated in a saddle at approximately
500 feet above mean sea level. The land slopes uphill to the
east and west. The surface of the site slopes downward to the
northwest to a spring and a small westerly flowing tributary of
Morgan Creek (informally referred to as Toftdahl Creek), or to
the southeast directly to Morgan Creek/ about 350 feet away and
200 feet lower in elevation.

The general land use in the area is rural residential, with
approximately 14 homes in the approximately 90 acres between NE
189th Street and Morgan Creek. Most of these homes obtain their
water from wells which are screened at least 70 feet below the
surface. The natural vegetation at the site is dense and
consists of a mixture of second-growth coniferous forest and
brushy cut-over areas. Access to these homes and to the site is
via an unpaved road.

Site HlstOCY

In the early 1970's, Mr. Toftdahl is alleged to have had
delivered to this property 100 to 200 drums containing unknown
amounts of industrial waste material, possibly from a plywood
manufacturer. His intent was to clean and then sell the drums,
but he was apparently unable to sell about 50 drums in which
waste residues remained. Mr. Toftdahl subsequently constructed a
burial trench about 500 feet from the cleaning location, placed
crushed drums into the trench, and covered the trench with
mounded dirt.

The drums were rediscovered in the mid 1970's after the new
owners of a portion of the Toftdahl property, the Davis's,
attempted to level the mound over the burial trench. In 1978 or
1982, approximately 38 drums were removed from the site by Mr.

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Toftdahl and disposed of in a local landfill, while approximately
12 drums were reburied in the final burial location.

The Washington Department of Ecology (Ecology) was first
notified about the possible presence of buried drums in 1982. In
1983 the Environmental Protection Agency's (EPA) FIT contractor,
Ecology and Environment (E&E), conducted a site investigation
which included a magnetometer survey, soil and surface water
samples, residential well groundwater samples, and a subsurface
exploration in the area defined by the magnetometer survey as
potentially having buried metal materials. Approximately six
crushed and badly rusted drums were sampled and stored on-site.
A fence was placed around the final drum burial area. (Area III
in Figure 2.) Samples were collected from six of these drums.

In November 1983, the Washington Department of Social and
Health Services (DSRS) determined that, based the available
sampling data, there was no immediate public health hazard in
drinking water taken from residential wells near the site.
However, DSHS was concerned that there was an "obvious potential
for contamination ..[from] inorganic sources of contamination" as
the soil and drum samples did have high levels of both heavy
metals and various synthetic organic compounds in the area of
E&E's first sampling. Additional samples ftorn several wells
taken in February, March, July, and November 1984 and May 1985 by
Ecology continued to show no significant degradation of water
quality. (See the Current Site Status section below for
additional information.)

In May 1984, Ecology nominated the Toftdahl Drum site for
addition to the National Priorities List under CERCLA. Also in
May 1984, Ecology took soil samples from the area where Mr.
Toftdahl's drum cleaning activities were alleged to have
occurred. No organic contaminants were detected, and no gross
quantities of heavy metals were found in this area.

Using state monies, Ecology's contractor, Dames & Moore,
became involved with the site in December 1984 with a site survey
and magnatometer survey designed to identify additional potential
burial areas. Six potential drum burial locations were
identified, including five outside the E&E fenced area. After
plans and specifications were prepared by Dames and Moore for
drum and contaminated soil removal. Initial Remedial Measure
(IRM) work was initiated in June 1985 by Riedel Environmental
Services, Inc..

No subsurface drums were found outside the fenced area
during the IRM. The five potential drum burial locations were
found to generally contain metal debris at or just under the
surface. Exploratory digging was also performed where paint chip-
looking materials were found. These waste materials were present
at widely scattered locations from 0 to 6 inches below the ground

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surface.

Twenty exploratory pits were dug inside the fenced area, in
total, five crushed drums and parts of additional drums were
unearthed and 40 cubic yards of visibly contaminated soil
collected. Subsequent analysis demonstrated that none of the
material was classifiable as a RCRA hazardous waste by the EP
toxicity procedure. All drums, contaminated soils, waste
materials and decontamination waters were disposed of off-site at
the CSSI hazardous waste landfill at Arlington, Oregon.

As lead agency for the site, Ecology's Remedial
Investigation (RI) was performed by Dames & Moore and was
designed to: 1) characterized the nature and extent of the
contamination present, and 2) provide a data base sufficient for
the evaluation of remedial alternatives. The RI was begun in
December 1985 and was completed in July 1986.

Current Site Status

The recent environmental sampling and chemical analysis
program shows no significant or extensive contamination of
surface soils, surface water, or groundwater at the site. While
several priority pollutants have been detected in the RI sampling
and analysis program, the concentration of such contamination is
very small and in most cases could not be reliably differentiated
from background values or laboratory-introduced .variability. In
fact most of the potentially waste related indicator constituents,
that have been detected have not been consistently detected over
repeated sampling events at the site.

Wastes

Pre-RI chemical data for drum/waste samples and adjacent,
soil samples show that the drum cleaning and disposal activities
at the Toftdahl site did introduce some contaminants at the site.
Priority pollutants which had been detected at least 1 time in
the drum/waste or nearby soil samples were used as indicator
constituents in the RI. (See Table 1.) The indicator constituents
include metals, volatile organic compounds, base/neutral organic
compounds, cyanides, and PCBs.

As waste characterization was based solely on chemical
analysis of samples collect at the site, rather than on certain
knowledge of the source or nature of the drummed materials, it is
possible that other organic compounds found during the RI and
earlier sampling may have been waste related. Available
information on the source of drums found at t:he Toftdahl site
indicates that they came from a plywood manufacturing plant. The
chemical profile shown by the waste analyses is consistent with
paint sludge wastes. Many plywood operations use paints for
marking the edges of plywood sheets to indicate type and grade.

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The concentration of contaminants in the laboratory analyses
of the waatea and soils collected from the site near these wastes
showed that, they were not RCRA hazardous wastes nor Ecology
dangerous wastes using both the EP toxicity test and the Ecology
bioasaay test.

Some white cake-like material similar to that found in and
near drums on the site is still visible at several scattered
locations on the site. These materials look like paint chips.
The Ecology project manager has described the density of these
•paint chips" as about what would land on a neighbor's lawn if
one's house had been scraped. As noted above, none of these
materials are RCRA hazardous wastes.

Soils

After the IRM was completed, RI samples from the top foot
of soil were taken from the suspected drum cleaning area, the
alleged initial drum burial area, the final drum burial area, and
a designated background area. Ecology had earlier taken samples
from the alleged drum cleaning area. Tables 2, 3 and 4 summarize
the results.

These tables show no significant inorganic contamination in
the soil. The only significant concentrations of-, organic
compounds are non-priority pollutant/ tentatively identified
compounds at the several thousand parts per billion (ppb) levels.
These appear to be primarily hydrocarbons and are probably
related to traffic on the dirt road rather than to site
contamination from drum disposal activities. A few common
solvent and phthalate organic compounds were detected at low ppb
concentrations. The EP toxicity test results show that none of
the soils could be classified as hazardous waste by that test.

Surface Water

Analysis of water samples from Toftdahl Creek identified
contaminants which are consistent with minor contamination from'
surface runoff; distinguishing such minor effects from normal
variability between sites, geochemical influences and laboratory
and sampling errors cannot be done with assurance. Morgan Creek
does not appear to have received contaminants from the site.

The upstream Morgan Creek sampling location had the highest
zinc concentration, and had marginally higher concentrations of
the other inorganic parameters and phenols than the downstream
Morgan Creek sampling location.

For inorganic waste constituents other than zinc, Toftdahl
Creek has generally had higher maximum concentrations than Morgan

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Creek. Assuming a hardness of 50 mg/1, three of these inorganics
exceeded the freshwater aquatic ambient water quality criteria:
cadmium with a maximum concentration of 3 ppb, though cadmium was
not even detected in 5 out of the 7 sampling events at Toftdahl
Creek; lead with a maximum concentration of 23 ppb, though lead
was not detected in 4 sampling events; and copper with a maximum
concentration of 20 ppb, though copper was also not detected in 4
sampling events at Toftdahl Creek. Again assuming a hardness of
50 mg/1, water quality criteria for aquatic organisms for
cadmium, lead, and copper are as follow: cadmium, 2 ppb for both
long and short term; lead, 25 ppb short term and 1.0 long term;
copper 6.4 ppb short term and 5.8 ppb long term. Only copper at
5 ppb was found in samples collected in 1986 at the location
downstream of the site.

The generally higher maximum concentrations of potentially
waste-related inorganic constituents at Toftdahl Creek sampling
locations may reflect the unpaired comparisons over time, as
Morgan Creek was not sampled on the same dates as those maximums.
They may also reflect some natural geochemical or soils
differences. If they do reflect movement of Toftdahl site
contaminants by ground- or surface water, the magnitude of the
effect is quite small.

A total of 14 organic compounds has been detected in
Toftdahl Creek. However, only' four organic compounds have been',
detected on more than one sampling event, and of these, only two>.
phthalates have been reported at more than 1 ppb. Both of these;
phthalates were found in blanks during at least one round of;,
sampling. The two latest rounds of surface water samples have-
shown no detectable organic compounds in Toftdahl Creek.- Again
the lack of persistence over time may indicate that most reported
results are anomalies of sampling or laboratory procedures. This
conclusion is also supported by the generally low concentrations
of these compounds reported. No organics other than phenol were
detected in any of the Morgan Creek samples.

The areas of alleged drum cleaning and drum burial have very
slight topographic slopes and are moderately to well vegetated..
These influences tend to restrict surface runoff. However, the
soils present at the site have a moderate to high runoff
potential due to a reddish brown clay which is present near the
surface throughout much of the site. This clay has a vertical
permeability of 6.5 x 10-7 cm/sec, which impedes the downward
movement of water.

Geology and Hydrogeology

A complex sequence of discontinuous sediments, sedimentary
rocks and volcanics underlies the site. Extensive weathering
and/or hydrothermal alternation has altered all but a few of the
original deposits to clays and silts. Generally, groundwater

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occurs in the coarser stratified sand, gravel and clayey gravel
zones at various depths. These water-bearing zones occur between
thicker sequences of clay and silt.

During construction of the five shallow Rl monitoring wells,
groundwater was encountered at very variable depths ranging from
6 to 33 feet below ground surface. It was not possible to
evaluate the hydraulic connection between the shallow saturated
zones, and thus, the potential shallow contaminant migration
pathways. It is likely that groundwater occurrences in some of
the thin shallow saturated zones is seasonally dependent, as some
of the shallow monitoring wells dried up during the RI study
period.

Deeper groundwater was encountered at approximately 95 feet
and 70 feet below the surface in the two deep monitoring wells.
This aquifer is a confined- aquifer as the water levels in the
deep borings rose to approximately 50 feet below ground level
after the water bearing zone was penetrated. Measured
groundwater elevations in the deep monitoring and private wells
indicate that the hydraulic gradient of the confined aquifer
ranges from 0.05 to 0.009, sloping generally to the south.
However, as the deeper water bearing strata is discontinuous,
there is some uncertainty regarding the hydraulic communication
between these units.

Groundwater

Private wells surrounding the Toftdahl site were sampled on
nine occasions. A total of 10 residences have been sampled at
least once, with one of the 10 served by a water supplier- rather
than by a private well. These private wells include both
upgradient and downgradient directions with respect to
groundwater flow from the site. Five shallow monitoring wells
and 2 deep monitoring wells were constructed as part of the RI.
The shallow monitoring wells were all constructed in areas
thought to be downgradient of the site's waste activity areas.
All private wells are deep.

Tables 5 and 6 summarize the groundwater chemistry data. It
should be noted that while private and RI monitoring well results
are displayed separately in these table, upgradient and
downgradient well results have not been separated.

Shallow groundwater (which has been sampled only from nearby
new monitoring wells, as all domestic wells are deep) appears to
have higher concentrations for many parameters than were measured
in deeper groundwater samples. The potential for pathways
between the relatively less pure shallow groundwater and the
deeper groundwater could not be established on the basis of
existing data.

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A total of 22 organic priority pollutant compounds (plus
other tentatively identified compounds) have been detected in
groundwater. They have not, however, been persistent and are
typically at very low ppb concentrations. Of these 22 organics,
nine had been found in the waste constituents. Also, of these
22, only five compounds out of 22 have been detected in more than
one sampling. Less than half of the organics have been
quantified at levels of 1 ppb or higher, and only two at 5 ppb or
higher. These two - bis(2-ethyl hexyl) phthalate and methylene
chloride - are both waste indicator constituents, but are also
common compounds that are sometimes seen in the blank quality
control samples. Also, of these 22, 13 have been found in
private wells that are upgradient of the site and are unlikely to
be related to the Toftdahl site by any potential surface or
ground-water contaminant pathway. The RI's conclusion is that at
least part of the data set is an artifact (lab or sampling
problem) or the contamination is from an independent source. For
example, the one residence that is connected to a water supplier
had three organic compounds detected, all on one sampling round.
No organics appeared in any other sampling rounds at that
residence.

Compared to the regional background values, the maximum
ground-water concentrations of the metals at and near the
Toftdahl site are almost uniformly higher. This may reflect, in
part, the small number of samples included in the regional
background data set for some parameters. For example, while
aluminum is a possible constituent of paint sludge wastes,' it's
presence in the drums handled at the Toftdahl site has not been:
well documented. Hydrothermal alternations of soils and rocks:
may contribute to higher local levels. The private wells"have
shown higher maximum concentrations of copper and zinc, which is
probably related to their design and construction. For other
metals, the concentrations are higher in the shallow monitoring
wells than in either the deep monitoring and private wells.
However, Table 7 demonstrated that there are no significant
violations of drinking water standards in any well for the
inorganic waste indicator constituents.

Summary

It is likely that at least a substantial portion of the
surface and groundwater sampling results is an artifact of the
sampling and analytical program or reflects a source of
contaminants not related to the drum cleaning and disposal
operation at the Toftdahl site. However, the data is
insufficient to entirely eliminate the possibility that one or
more contaminants related to waste materials is still present at
the site, whether related or not, the magnitude of the
contamination is extremely small and does not exceed any
applicable or relevant and appropriate Federal public health or
environmental standard and does not appear to be a potential

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source for public health risks. There is no information to
determine what levels of contamination existed at the site prior
to 1983.

No enforcement actions have been taken and none are
currently underway. The ownership of the site is in dispute
between Mr. Toftdahl and the Davis's. A determination on whether
to recover Federal and State past costs will be made at a later
time.

community Relations

Local interest in the site and media coverage of activities
has been light and sporadic. Ecology held one public meeting in
December 1983 to discuss the test results and possible cleanup
actions. Community relations have also consisted of fact sheets
and direct communications advising residents when there will be
well and water sampling as well as investigation and cleanup
activities. Nearby residents have requested and received copies
of maps and reports on the test results on wells and streams neat
the site. The residents' concerns include impacts on property
owners who are trying to sell their homes.

Alternative Evaluation

A number of preliminary remedial technologies were listed in
the RI as maybe being appropriate for consideration as additions
to the actions which have already been taken at the site. These
include control of any possible contaminant release by removing
any remaining surface waste material and contaminated soil or
surface sealing, control of any possible contaminant migration by
grading or revegetating bare areas, and monitoring surface and
groundwater.

The site currently poses no health hazard to the public.
This is because the level of contamination at the site is very
low. Testing and analysis show that previous actions have
effectively eliminated any threats to the public health, welfare,"
and the environment. Therefore a Feasibility Study will not be
performed at this time.

According to section 300.68(i)(l) of the National Oil and
Hazardous Substances Pollution Contingency Plan, the appropriate
extent of remedy is that cost-effective remedial alternative that
effectively mitigates and minimizes threats to and provides
adequate protection of public health and welfare and the
environment.

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The recommended alternative is that no further Superfund
remedial action is necessary. Previous Ecology actions have
removed druma and any significant quantities of wastes from the
site. More than two years of groundwater monitoring have
demonstrated that there is currently no threat from the Toftdahl
drum site to drinking water quality at the nearby residences.
Similarly, there are currently no threats to surface waters from
the Toftdahl drum site.

For additional verification. Ecology intends to continue
performance monitoring by sampling and analyzing nearby private
residential and monitoring wells semi-annually for five years,
and then annually for ten additional years, subject to funding by
the legislature of the State of Washington. EPA concurs with
this precautionary measure. If significant contamination is ever
found in these wells, the no further action decision could be
reconsidered.

The no further action alternative is consistent with other
environmental laws. No RCRA hazardous wastes nor Ecology
dangerous wastes are present at the site. Federal drinking water
standards are met at the downgradient private wells for all waste
indicator constituents. No substances regulated by TSCA have
been found.at the site.

This site may be recommended for deletion from the National
Priorities list as it no longer presents a significant threat to
public health or the environment.

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TABLE 1

WASTE MATERIAL INDICATOR PARAMETERS (a)

Qrganlsa

Bis(2-ethyl hexyl)phthalate

Di-n-butyl phthalate

Di-n-octyl phthalate

Benzyl butyl phthalate

Napthalene

Phenanthrene

Fluorene

PCB 1254

PCB 1560

Toluene

Ethyl benzene

Methylene chloride

Tetrachloroethane

Benzene

Acetone

2-Butanone (MEK)

4-Methyl-2-pentanone

0~Xylene (1,2-dimethyl benzene)

tngcqsnicg

Concentration Range ia Wastes

(ppm)

b
b
0
0
0
0
0

0
0
0
0
0
0
0
0
0

-	400

91
15
12

7.1
.41
.18
.41
.61

-	44000

-	5500

.453
.4

-	50M

2.2

. 42M
1.7
. 16M

Arsenic

, 0

18.6

Cadmium

0

- * 3.1

Chromium

0

- 119

Copper"

5

- 590

Lead

0

- 1000

Mercury

0

- 115.?

Zinc

25

- 4430

Cyanide

0

16.3

(a) Includes (1) those organic compounds that were specifically
identified and for which quality control sample blank results
were below detection limits, and (2) those inorganics for which
sample results were above soil background values. The list of
inorganic indicator parameters includes three that are only
marginally above background values (arsenic, cadmium, and
chromium) and is thus conservative. It is possible that the
waste contains forms of these chemicals (or others) that are more
mobile than normal background soils; EP toxicity testing of
wastes, however, shows detectable leachate values only for
chromium (0.14 ppm.)

M designates an estimated value.

? on the mercury value indicates that spectral interference
prevented confirmation. The highest value unaffected by
interference is 19.4.

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