United States
Environmental Protection
Agency
Office of
Emergency and
Remedial ResponM
EPA/ROD/P09-85/010
September 1985
Superfund
Record of Decision:
Del Norte, CA
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TECHNICAL REPORT DATA
(Please read Instructions on the rtvtnt before completing)
1. REPORT NO.
EPA/ROD/R09-85/010
4. TITLE AND SUBTITLE
SUPERFUND RECORD OF DECISION
Del Norte, CA
7. AUTMORISI
0. PERFORMING ORGANIZATION NAME AND ADDRESS .
12. SPONSORING AGENCY NAME AND ADO
U.S. Environmental Protectio
401 M Street, S.W.
Washington, D.C. 20460
RESS
n Agency
3. RECIPIENT'S ACCESSION NO.
8. REPORT DATE
September 30, 1985
6. PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION REPORT NO.
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
13. TYPE OF REPORT AND PERIOD COVERED
Final ROD Report
14. SPONSORING AGENCY CODE
800/00
IS. SUPPLEMENTARY NOTES :
16. ABSTRACT
The Del Norte County Pesticide Storage Area Site, located approximately one mile
northwest of Crescent City, CA consists of less than one acre of land contaminated with
a variety of herbicides, pesticides, and volatile and semi -volatile organic compounds.
Interim and emergency storage activities that occurred during the site operations from
1970 to 1981 have resulted in the contamination of soil and ground water onsite.
Available documentation about the actual day-to-day site operations is inadequate.
However, site investigations revealed that a sump, approximately 15 feet by 20 feet,
is the primary area of soil contamination, with organic compounds detected to a depth
of approximately 15 feet below grade. It is suspected that wastes and/or rinse water
were disposed of in the sump. Primary contaminants detected in both soil and ground
water are 2,4-D and 1,2 dichloropropane.
The selected remedial action for the site includes : excavation and off site disposal
of approximately 700 cubic yards of soils from the sump and trench areas to a RCRA ap-
proved< facility; extraction of contaminated ground water; treatment of ground water
contaminated by organics and pesticides by carbon adsorption; offsite disposal of
spent carbon filters to a RCRA approved facility; treatment of chromium contaminated
ground water by coagulation and sand filtration technologies; offsite disposal of
chromium-rich waste brine to a RCRA approved facility; piping treated ground water to
(see separate sheet)
17.
t. DESCRIPTORS
KEY WORDS AND DOCUMENT ANALYSIS
6.IDENTIFIERS/OPEN ENDED TERMS
Record of Decision
Del Norte, CA
Contaminated Media: gw, soil .
Key contaminants: VOCs, 2,4-D, .. .
1,2 dichloropropane, herbicides, pesticides, .
chromium
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53
22. PRICE
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EPA Form 2220-1
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SUPERFUND RECORD OF DECISION .
Del Norte, CA
Abstract - continued .
the County Sewer main; and ground water monitoring in accordance with RCRA Part 264,
Total capital cost is estimated to be $1.24 million with no O&M requirements.
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Record of Decision
Remedial Alternative Selection
SITE Del Norte County Pesticide Storage Area,
Crescent City, California
DOCUMENTS REVIEWED
My decision is based primarily on the following documents
describing the findings of EPA's Remedial Investigation and the
analysis of cost-effectiveness of remedial alternatives for the
Del Norte site:
- Study entitled "Del Norte County Pesticide Storage Area
Site Remedial Investigation, Draft Report*, July, 1985.
- study entitled "Del Norte County Pesticide Storage Area
Site Feasibility Study, Draft Report", July, 1985.
- Summary of Remedial Alternative Selection.
- Community Relations Responsiveness Summary.
DESCRIPTION OF SELECTED REMEDY
- Excavation and removal of contaminated soils to a RCRA
approved, offsite. Class 1, hazardous waste disposal
facility.
- Extraction of contaminated ground water.
'?
- Treatment of ground water contaminated by organics and
pesticides by carbon adsorption.
- Disposal of spent carbon filters containing organic con-
taminants to a RCRA approved, offsite, Class I, hazardous
waste disposal facility.
- Treatment of ground water contaminated by chromium by
coagulation and sand filtration technologies.
-Disposal of chromium-rich waste brine to a RCRA approved,
offsite, Class I, hazardous waste disposal facility.
- Disposal of treated ground water by piping to the County
sewer main.
- Ground water monitoring in accordance with RCRA Part 264.
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DECLARATIONS
Consistent with the Comprehensive Environmental Response,
Compensation, and Liability Act of 1980 (CERCLA), and the National
Oil and Hazardous Substances Contingency Plan (NCP) (40 C.F.R.
Part 300), I have determined that excavation and offsite disposal
of contaminated soils, and pumping and treatment of contaminated
ground water along with disposal of treated ground is adequate
to protect public health, welfare, and the environment. The
State of California Department of Health Services and the North
Coast Regional Water Quality Control Board have been consulted
and fully support the approved remedy. ~
I have also determined that this action is appropriate when
balanced against the availability of Trust Fund monies for use at
other sites. In addition, the off-site transport and secure
disposition of contaminated soils along with disposal of treated
ground water by piping to the sewer main is more cost-effective
than other remedial actions, and is necessary to protect public
health, welfare, and the environment.
. 65"
DATE VX JUDITH E. AYRES
ft* Regional Administrator
U.S. EPA Region 9
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SUMMARY OF REMEDIAL ALTERNATIVE SELECTION
DEL NORTE COUNTY PESTICIDE STORAGE AREA SITE
CRESCENT CITY, CALIFORNIA
September 30, 1985
Prepared by Michele S, Dermer
Federal Response Section
Superfund Programs Branch
Toxics and Waste Management Division
United States Environmental Protection Agency
215 Fremont Street
San Francisco, California 94105
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SUMMARY OF REMEDIAL ACTION SELECTION
DEL NORTE COUNTY PESTICIDE STORAGE AREA SITE
Crescent City, California
SITE LOCATION AND DESCRIPTION
The Del Norte County Pesticide Storage Area Site, located
approximately one mile northwest of Crescent City, California,
consists of less than one acre of land contaminated with a variety
of herbicides, pesticides, and other compounds. The site is
located in a rural area immediately south of McNamara Field, the
airport which serves Del Norte County (See Figure 1). According
to the California Department of Finance, approximately 18,300
people presently reside in Del Norte County. The population for
Del Norte County is projected to be 24,100 by the year 2000 (an
increase of about 30% over the present population).
As of January, 1985, the population of Crescent City was
estimated at 3,280. In 1982, EPA estimated that 250 persons
lived within one mile of the Del Norte County Pesticide Storage
Area Site. No substantial change has occurred since then.
The Del Norte site and the land surrounding it are owned by
Del Norte County. The storage site itself, closed in 1981, is
fenced, locked, and posted with a public notice stating that
hazardous substances may be present. The entire County-owned
parcel (including the site) covers an area of approximately 480
acres. The County property is bounded on the north by state-
owned land, which is intended for use as a natural and recreational
area; on the south by Washington Boulevard and privately owned
farmland; on the east by Riverside Drive and approximately seven
private residences; and on the west by the Pacific Ocean.
SITE HISTORY
In December, 1969,'the Del Norte County Sanitarian notified
the North Coast Regional Water Quality-Control^Board^tNCRWQCB^p""" "*
of the County's intent to operate a pesticide container storage
area. The designated site, 200 feet long and 100 feet wide, was to
be located at the southern border of the McNamara Field County
Airport, 3/4 of a mile east of the Pacific Ocean. The County
requested operating advice and approval from the NCRWQCB, and in
January 1970, the NCRWQCB responded with suggested.operating .
procedures and requested additional information about the site.
During 1970, the site was designated by the NCRWQCB as a Class
II-2 disposal site. It was to serve as a county-wide-collection
point for interim or emergency :storage of pesticide containers
generated by local agricultural and forestry-related industries.
The NCRWQCB approved the site for this use, provided that all
containers were triple rinsed and punctured prior to arrival at
the site.
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Figure 1. LOCATION MAP
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In 1974, the California Department of Health Services (DOHS)
issued a memorandum requiring hazardous waste handlers to comply
with a monthly reporting system and fee schedule. The Del Norte
site was exempted from the rule due to the small quantities of
waste which they handled. DOHS requested that Del Norte County
keep accurate records of their operations in spite of the
exemption. j
In early November, 1976, a NCRWQCB representative inspected
the site. On November 12, 1976, the NCRWQCB approved the site
for interim and emergency storage of small quantities of
industrial and agricultural wastes and pesticide containers. The
NCRWQCB waived the Report of Waste Discharge requirement for the
site, but required the County to log all incoming wastes and
affirm that all empty containers brought to the site had been
triple rinsed.
Very little documentation is available about actual day-to-
day site operations, site investigations have revealed that a
sump approximately 20 feet long, 15 feet wide and several feet
deep was constructed on-site. Testing revealed that this sump
contains the highest chemical concentrations on-site. It is
likely that wastes and/or rinse water had been disposed of in the
sump.
On August 13, 1981, an inspection of the site by the NCRWQCB
revealed that the in-coming drums had not complied with the
triple-rinse and puncture procedures and that the County had
failed to keep an accurate log of incoming wastes. One week later,'
the County ceased accepting deliveries at the site. Based on an
inspection report, there were approximately 1,600 drums on the
site, and only a few were properly rinsed and punctured. The
condition of the drums ranged from badly corroded to nearly new.
The available log of incoming wastes was inspected and found to
date back only to 1979. The EPA inspected the site on September
25, 1981, and found numerous Resource Conservation and Recovery
Act (RCRA) violations.
As a result of the site inspections, the NCRWQCB issued-
Cleanup and Abatement Order No. 81-213 in October, 1981, which
required the removal of all hazardous wastes (e.g. drums) to a
site authorized to accept California-designated Class I wastes.
The order also required the County to determine the extent of
potential contamination by sampling and analyzing soils and by
installing exploratory monitoring wells to sample ground water.
The County in turn requested financial assistance from the DOHS
to comply with this order later that month. In November 1981, .
Del Norte County submitted a proposed site closure plan to the
NCRWQCB.--
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In January 1982, the County removed 1,150 of the containers
from the site. The rusted or corroded drums were removed and
disposed in a section of the Crescent City Landfill. The County
Agricultural Commissioner certified that the remainder of the
1,150 drums had been adequately rinsed prior to storage at the
Del Norte Storage site. These drums were also disposed of in a
different section at .the Crescent City Landfill. In April,
1982, the remaining 440 unrinsed drums of D-D and Telone were
shipped to a licensed recycler, the Rose Cooperage Company, in
Montebello, California. ,
During these activities, several drums on the site were
found to contain usable quantities of various pesticides, which
were recycled by the County Agricultural Commissioner for weed
control. These drums were then triple-rinsed and disposed of at
the Crescent City Landfill. The rinsing location is unknown.
Three remaining drums containing pesticides that were not recyclable
(i.e. 2,4-D sludge, Thimet, and miscellaneous materials) were put
in a vacant building near the County Agricultural Commissioner's
office for later shipment to a Class I disposal site. In November,
1983 the three drums were shipped to a disposal site in King City,
California.
Under the NCRWQCB Cleanup and Abatement Order 81-213, the
County was charged with determining the extent of potential
contamination at the site. The County was unable to comply with
the order due to lack of funding, so the NCRWQCB and the DOHS
carried out post-closure monitoring.
The DOHS collected on-site soil samples from three locations
in December 1981. An additional 21 soil samples were collected
in June 1982. The results of their analyses showed high concen-
trations of 2,4-D, 2,4-DB, 2,4,5-TP, 2,4,5-T, ethion and malathion
in several areas, particularly the sump and areas of known drum
storage.
The NCRWQCB collected ground water samples from two on-site
monitoring wells which were installed for that purpose, as well
as nine off-site supply wells, In September 1982 and early 1983.
The on-site water samples showed elevated levels of the same
contaminants found in .the soil, along with several other compounds.
On the basis of these results, the NCRWQCB determined that a
problem existed at the site, and amended its Cleanup and Abate-
ment Order 81-213 in August 1983 to require that the extent of
contamination be determined. A plan for cleanup and/or abatement
of the contamination was also to be developed. The Del Norte
County Board of Supervisors asserted in a letter to DOHS that
the County was unable to fund a study to determine the extent
of contamination. The County's inability to fund further site
investigations triggered the process of incorporating the site
on the National Priorities List, in the fall of 1983.
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CURRENT STATUS
EPA conducted a remedial investigation and feasibility study'
(RI/PS) which began in January 1985 after the workplan for the
site The Del Norte County Pesticide Storage Area Site Remedial
Investigation and Feasibility Study Work Plan was completed
and approved."7
EPA conducted remedial investigation activities at the site
from January to May 1985. During the remedial investigation,
ground water, soil, and surface water were sampled in and around
the site property. Results of the surface soil sampling program
are shown in Pigure 2. Six soil borings were sampled and results
are illustrated in Pigure 3. As part of the ground water inves-
tigation, water monitoring wells were installed and sampled in
the vicinity of the site. An additional five domestic supply
wells were sampled as part of the RI. Pigure 4 shows the location
of the wells sampled, and results of sampling rounds are shown
in Table 1-1. As part of the remedial investigation, a computer
ground water model was used to better understand the flow of
ground water in the area of the site, and to predict movement of
contaminants from the site.
The major findings of the remedial investigation ate:
"Activities that occurred during the site operations from
1970 to 1981 have resulted in contamination of soil and
ground water on-site. The contaminants are herbicides,
pesticides, and volatile and semi-volatile organic
compounds.
The primary contaminants of concern in both soil and
ground water are 2,4-D and 1,2 dichloropropane. Ingestion
of these contaminants at levels above the relevant drinking
water criteria has been linked to an increased cancer
risk. The remedial investigation has shown the on-site
monitoring well to contain 2,4-0 at a level of 150 ppb;
50 ppb higher than the applicable drinking water standard
(MCL). 1,2 dichloropropane was seen at levels of 1200
ppb; with the applicable drinking, water advisory*(-SNARLS^ii:»
set at-10 ppb^for^long-teriir exposure. Use of the contamin-
ated on-site ground water as a water supply would result
in a significant health risk.
* The on-site sump, measuring 15 feet by 20 feet is the
primary area of soil contamination, with organic compounds
detected to a depth of about 15 feet below grade. Contam-
ination of soils on the remainder of the site is restricted
to very limited areas, including a previous trench area.
Contamination in these^ar.eas'-^Bv"ll-ke~j(y^a'8'~a:'"'re;8'Ult'"'o£'"'.
leaks or spills from drums. No contamination below 1 foot
was detected outside the sump. The spread of soil contam-
ination off-site due to wind or runoff was not detected.
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Figure 2.
CONCENTRATION DPI1
SITE BOUNDARY
MOO
1. IOP
1/iJMD
JAO
0
1. 100
0. §00
IV 000
0.000
III
IN (UM'ACI I
OUADMAKT I07.W*
CONTAMINAHTf Ml Of UK*
OUACWAMTU4.M*
UOINO
1.1.2.
T«im>
II COI
- *li«r*ll*Mt
VIOT
Oxuotl
wink)
MO tol rv
4.'4-DOT
tt.oot M/DI
11.000 m/oi
11.000 uuoi
1.400 IWOI
40 «VO)
>?o aval
tl M/DI
MO «vei
11. MB ti.'oo
114.000 »4,IOO
n.ooo n.ooo
OONTAMIHANTS DETECTED IN SURFACE SOILS.
JANUARY 1985 SAMPLES
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Figure 3.
ill
I.I
1 Jilt
MHO
I-4IIJ1
mm
MIMl
MOT
Mturt
nun
Mtri
.M 14.41
MM.I1
4.1 in
4JH.41
u IMI
J.«O
1.45 1
ri.4*
14.000
11.000
S7O
47
1.400
130
u
IJOO
no
(70
1*00
IJOO
14^00
MJOO
114.41
11441
O n/o
O-I1M-1 U
II
10.400
O »'O
o Mm
OH/0
4.4-000
14.900
mom
.on
00
I4JOO
m.ooo
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ONMGSISANOK
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17 J 'ricMon>f»oix». I
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fend to. 7.4 0:>.4j).r!l
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11.300 A^nlt. J77.000 Chombn
m COOMI 5 000
HID NoiMfif Mnend
CONTAMINA?TT5'OF,TECTEO IN ''»
sxiS'j'ri^rf sour
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EXPLANATION
Private Welt
A Monitoring Well
«S Groundw«ter Contours - April 28. 1985
(dashed where inferred)
Topographic Contour Interval - 10 feet
0 280 SCO
1000 «wi
Monitoring Well Locations and April Groundwater Contours
Del Norte County Pesticide Storage Area Site
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Table 1-1. VOLATILE, SEMI-VOLATILE AND PESTICIDE COMPOUNDS IN.GROUNDWATER
Location
MW-1
MW-1 7
(duplicate
of MW-1)
MW-5
MW-1 8
(duplicate
of MW-6)
MW-12
MW-1 4
Compound
1 ,2-Dlchloropropane
Benzene
1 ,3-01ch1oropropane
1,2,3-Trlchloropropane
2,4-D1ch1oropheno1
Pentachlorophenol
2,4,5-Trlchlorophenol
2,3,4,5-Tetrachlorophenol
Methylene chloride
2-Butanone
2,4-D
2.4, 5-T
2.4,5-TP
ds-3-Chloroallyl alcohol
1 ,2-01ch1oropropane
Benzene
1 ,3-01ch1oropropane
1,2,3-Trlchloropropane
2,4-D1chlorophenol
2,4,5-Trlchlorophenol
2,3,4-5-Tetrachlorophenol
Methylene chloride
2,4-0
2, 4. 5-T
ds-3-Chloroallyl alcohols
2.4-01chloropheno1
2,4,5-Trlchlorophenol
2,3,4 , 5-Tetrachlorophenol
Total Xylenes
2,4-0
4,4'-ODE
4',4'-DOT
2,4-0
Benzo(a)anthracene
Chrysene
Benzo( e) f 1 uroanthene
Benzo(a)pyrene
Phenanthrene-
Anthracene
Pyrene
2-23-85
1900
6
15
47
18
. *
34
66
* .
*
26
68
1.2
*
2100
6
16
50
15
32
57
*
40
84
*
15
32
57
6
2V
' *
''. * - :
0.6
7
8
3
6
8
3 "'
13
Concentration (ppb)
3-5-85 3-25-85
1400 1200v
* 68v
* '
*
11
24
20
*
110
39V
100V 150v
47V llOv
* *
17b
1200 1200v
*
*
'*
8
14
*
62v
82v 50v
41v llOv
20b
*
*
* .._
* '
12v
0.2
2 ~
* ~
'
.. i . ' '-
-:,..- ','
"
a
4-28-85
..
~
~
.
__
-.
-+
-^
.
*
*
*
*
*
_
__
'
~
-
-------
Table 1-1. VOLATILE, SEM'-VOLATILE AND PESTICIDE UJHPOUNDS IN GROUNDWATER
(concluded)
Location
MW-25
MW-17
(duplicate
of MW-25)
HW-15
(blank)
Compound
1,2-Dlchloroprane
Toluene
Xylenes
Pentachlorophenol
Napthalene
Benzole Add
Carbon tetrachlorlde
Methylene chloride
Chloroform
Concentration (ppb)a
2-23-85 3-5-85 3-25-85 4-28-85
-' _ . '
».« .
.'
.. . \~ - - : -
-- "~
* ' *
* *
* ' *
. __-,
- . '
.
--
37v
78v
18v
5
46
5
50
10
50
*
*
*
aA11 values reported by EPA Contract Laboratories as estimated and valid
for planning purposes (unless otherwise noted).
^Lack of trans Isomer makes this Identification tentative.
"Compound not detected.
Not sampled on this date.
v-Results reported as valid for all purposes.
-------
". Many of the compounds found in the soil were also detected
in the ground water beneath the site. Ground water contaraj
ination has spread a distance of about 150 to 300 feet in
the southeasterly direction from the on-site sump area.
" Potential use of the contaminated aquifer poses an immediate
public health threat. Projections of future migration
of ground water contaminants indicate that under conservative
modeling assumptions, existing private wells to the
southeast of the site could become unsuitable for use in
the next 50 to 100 years. .
CHROMIUM DISCOVERY
In September 1984, during EPA workplan development, penta-
chlorophenol was detected in a subsurface soil sample. Since
pentachlorophenol is used as a wood preservative, EPA decided
to analyze future soil and ground water samples for metals (copper,
arsenic, and chromium) associated with wood treating. Copper
and arsenic were detected at insignificant concentrations;
however, high levels of chromium were detected in January 1985
surface soil samples (see Figure 2), February 1985 subsurface
soil samples (see Figure 3) and February, March, and April 1985
ground water samples (see Table 1-2).
The chromium analyses described above were for total chromium,
and it is not known in what form (trivalent or hexavalent) the
chromium exists. Hexavalent chromium is more toxic than trivalent
chromium. EPA's Maximum Contaminant Level (MCL) for total chromium1
is 50 ppb. Water samples from existing domestic wells in the
vicinity of the site showed total chromium considerably below 50
ppb. Samples from the other monitoring wells showed total chromium
averaging five times the drinking water standard, with maximum
values over ten times the standard (547 ppb).
Two facts indicate that the chromium contamination is not
the result of past disposal practices at the pesticide storage
area site: 1) background monitoring wells upgradient of the site
also contain high levels of ch'rQmium^-andv.2)'-«there^8?nowh*i>s'-t6rl'c'a~l::'*:''-''
information which indicates that chromium or chromium compounds
were handled at the site.
We intend to investigate the chromium contamination as a
separate site because there is no apparent relationship to the
pesticide storage area site. Our next step will be to establish
whether the chromium is either hexavalent or trivalent. Following
the results of these analyses, we will proceed with the identification
of possible sources of chromium, and determination of the extent-
of contamination;--- ~ : -...-. ; ,fl;
-------
Table 1-2.
CHROMIUM RESULTS
Dissolved
Hexavalent Dissolved
Total Total
Sample Cr, 2/85 Cr, 3/85
Mtf-l NO NO
W.|7 (MM duplidate 22 NS
MW-2 190 177
MN-3 291 547
MW-4 157 247
MW-5 , 83 187
M₯-6 331 355
MW-18 (MW-6 duplicate) 420 NS
MW-7 372 226
Mt-8 (44 84
W-IO NO 23
MM-15 (field blank) NO NS
MM-25 NS NS
MM-26 NS NS
W-28 (field blank) NS NS
NS «' not sampled
NO - not detected: Cr detection 1 imit 10 ppb
* e duplicate analysis not within control limits
Total
Cr. 4/85
' NS
NS
NS
NS
NS
38
NS
NS
MS
NS
NS
NO
104
305
NS
Cr (Vl)«,
7/24, 25
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
Total Cr6,
7/24, 25
NO
NO
NO
II
5
NO
II
(101
NO
NO
NO
NO
19. 3 J
(91
(91
a unecfdlfled samples for hexavalent chromium must be filtered (0.45 mm) end separated
or within 24 hrs of receipt; samples must be
maintained
b = unacidified IL bottle, senile must be filtered (0.45 mm)
c » acidified IL bottles
() « indicate Cr between contract detection limit
at 4°C until
analysis
Total
Cr6,
7/24, 25
52
12
353
94*
117*
17
245*
150*
32
34
19
20
213*
81*
64*
A.S.A.P.
prior to analysis
and the Instrument detection Malt
-------
ALTERNATIVES EVALUATION
The major objective of the feasibility study was to evaluate
remedial alternatives using a cost-effective approach consistent
with the goals and objectives of CERCLA. A cost-effective remedial
alternative is defined in the National Oil and Hazardous Substances
Contingency Plan (NCP) of July 16, 1982 (40 C.P.R. 300.68J) as
"the lowest cost alternative that is technologically feasible and
reliable and which effectively mitigates and minimizes damage to
and provides adequate protection of public health, welfare, or the
environment." The NCP outlines procedures and criteria to be used
in selecting the most cost-effective alternative.
Three levels of screening were performed on the remedial
/action alternatives. First, an initial technology screening was
performed to eliminate inapplicable, infeasible, or unreliable
technologies. Next, an initial alternative screening was performed,
according to the NCP 40 C.P.R. Part 300.68(h) was performed.
Finally, we performed a detailed alternative evaluation, according
to the NCP 40 C.F.R. Part 300.68(1).
Based on site background information and the nature and
extent of the contamination as defined by the technical investigation
to date, we developed the following general objectives for cleanup
of the Del Norte Site:
"To minimize off-site contaminant migration via ground
water, and . . . .
" To minimize exposure to contaminated soil.
Key specific cleanup objectives are:
" To prevent the contamination of nearby wells, and
"To clean up the ground water and soils found to be
contaminated on-site.
Cleanup of soils; and -ground water will also serve to address
the objective of maximizing the potential use of the land and the
aquifer in the area. The contaminants of primary concern at the
Del Norte site are 1,2-dichloropropane, and 2,4-D, and chromium
because: (1) they were detected in soils and ground water at high
levels, and (2) they have adverse effects on public health and
welfare and the environment. These compounds were found in
both the soils and ground water at the site at levels exceeding
applicable standards and criteria.
For soils, the preferred cleanup level is background,
concentrations. Natural soils, however, do not contain synthetic
compounds such as 1,2-dichloropropane and 2,4-D. Thus, a standard
other than background is required. In general, exposure to con-
taminated soil could occur by direct contact or by the compounds
in the soil leaching into the ground water. At the Del Norte Site,
-------
contaminants are generally below levels of concern for direct
exposure. However, during the winter months when the ground
water reaches the ground surface,.the contaminants in the soil
would leach directly into the ground water. If we assume the
contaminants leach into the ground water at an equivalent
concentration, our cleanup objective for soil would be the
applicable drinking water standard.
Cleanup of chromium in soils or ground water was not
explicitly included as an objective because the nature and extent
of this problem is not sufficiently understood. Chromium was
considered only because it influences the treatment and disposal
technologies for organics. Thus, the treatment of chromium
present in the ground water will be limited to any ground water
that may be pumped out and treated for the removal of organics.
The relevant criteria for soils and ground water cleanup at
the site are as follows:
Contaminant
1,2-dichloropropane
2,4-D
Total Chromium
100 ppb
50 ppb
Basis (Federal Criteria)
Suggested Adverse
Response Level
(excess cancer risk of 10~6)
Maximum Contaminant Level
Maximum Contaminant Level
The relevant standards and criteria cited above were the
basis for remedial action technologies and alternatives described
herein.
Response objectives for the soil and ground water contamina-
tion problems at the Del Norte Site include minimizing impacts
from on-site contaminated soils and minimizing off-site contaminant
migration via ground water. Response actions that address these
objectives also address the goals of soil and ground water cleanup.
General response actions for soil and ground water cleanup
that would be applicable to the Del Norte site include:
(a) For soils
* In-situ treatment
" Off-site treatment
Off-site disposal
" Capping/encapsulation
-------
(b) For ground water
" Containment
" Pumping
" Collection systems .
" On and off-site treatment ..'-.''
' Off'-site disposal
A complete list of technologies considered for the Del Norte
site is included in Table 2-1. The table also, includes our
decision regarding the applicability of each technology.
The applicable technologies identified were combined to form
remedial action alternatives that address the cleanup of both
contaminated soils and contaminated ground water. In order to
reduce the number of alternatives that would be evaluated in
detail/ the applicable technologies were examined with regard
to technical feasibility, degree of public health protection
afforded/ environmental impact/ institutional concerns/ and cost.
Those technologies that provided the best environmental and public
health protection benefits for the least cost were designated as
preferred technologies. The others were eliminated.
Preferred technologies for the various components of soil
and ground water cleanup are identified in Table 2-2.
According to the proposed NCP, 40 C.P.R. Part 300.68(f)
alternatives must be developed for each of the following five
categoriest . .
a. Alternatives for treatment or disposal at an off-site
RCRA permitted facility approved by EPA.
b. Alternatives tha.t attain applicable and relevant federal
public health br environmental standards.
c. As appropriate/ alternatives that exceed applicable and
relevant public health or environmental standards.
d. Alternatives that do not attain applicable or relevant
.,..;, ...._ public health or environmental standards but which will
reduce the likelihood of present or future threat from
; the hazardous substances. This must include an alter-
native that closely approaches the level of protection
provided by the applicable^or-,relevant^standardsf'and
meets CERCLA's objective of adequately protecting public
health and welfare and the environment.
e. A no-action alternative.
-------
TABLE 2-1. SCREENING OF TECHNOLOGIES CONSIDERED FOR THE DEL NORTE SITE
Possible Technologies
Screened Out(S)
or
Retalned(R)
If Screened Out, Reason
for Doing So
SOIL EXCAVATION
SOIL DISPOSAL/TREATMENT
Capping/encapsulation
Dispose of excavated soil
Incinerate excavated soil
Dispose of excavated soil
Treat soil on-slte
In on-slte landfill
at an on-slte temporary facility
In off-site RCRA landfill
Incinerate excavated soil using a mobile Incinerator
GROUNOHATER CONTAINMENT/EXTRACTION
Slurry wall containment
Pumping alone
Pumping with an underdraln system
GROUNOHATER TREATMENT
(a) For Removal of Organic*
Carbon adsorption
Aeration
(b) For Removal of Chromium
Coagulation/filtration treatment
Carbon adsorption
S
s
S
R
R
R
S
R
S
R
R
R
S
Technically Infeaslble
Technically Infeaslble
Excessive cost
Excessive cost
Excessive cost
Technically Infeaslble: not
effective for chromium VI removal
-------
TABLE 2-1. SCREENING OF TECHNOLOGIES CONSIDERED FOR THE DEL NORTE SITE (concluded)
Possible Technologies
Screened Out(S)
or
Retalned(R)
If Screened Out. Reason
for Doing So
GROUNOMATER DISPOSAL
Dispose of untreated water In an off-site RCRA facility S
Dispose of untreated water by piping It Into the S
Crescent City sewer main or sewer outfall
i J ' .
Dispose of untreated water Into an evaporation pond S
Dispose of treated water Into a percolation pond
Inject treated groundwater back Into ground S
Dispose of treated water by trucking It to the R
Crescent City wastewa'ter plant
i.
Dispose of treated water by piping It to the R
nearest Crescent City sewer main
Dispose of treated water Into the ocean R
9 I '
Dispose of treated water to surface drainage R
Excessive cost
Excessive cost
Technically Infeaslble: rate of
precipitation plus Inflow
greater than rate of evaporation
Technically Infeaslble: rate of
precipitation plus Inflow
greater than rate of percolation
and evaporation
Technically Infeaslble:
operational problems
-------
The preferred technologies listed in Table 2-2 were combined
to form remedial action alternatives which satisfy cleanup
objectives and fall into the five categories described above.
Table 3 lists the remedial action alternatives which were retained
for detailed analysis. At least one of the remedial action
alternatives in Table 3 falls into each of the above categories,
as follows:
Category a -Alternatives 2, 3, 4, 5, 6
Category b - Alternatives 3, 4, 6
Category c - Alternative 6 '
Category d - Alternative 2
Category e - Alternative 1
The remaining alternatives were analyzed in detail according
to the NCP, 40 C.F.R. Part 300.68 (i). Alternatives were evaluated
in terms of cost/ technical concerns, public health concerns and
environmental impacts. The following discussion describes this
detailed analysis. Costs developed for the alternatives are within
+50% and -30% of the actual construction costs.
Alternative 11 No Action;
The no action alternative would leave the contaminated soils
and ground water in their present locations. However, monitoring
of the site would be required to continue indefinitely to detect
the migration of the contaminant plume. Annual cost of $35,000
for monitoring would amount to a total present worth over 30 years
of $330,000.
The contaminated soils would be a continuing source for
contamination of ground water. The plume of contaminated ground
water would migrate with time and might reach domestic supply
wells. In addition, future well development of the aquifer in
the vicinity of the plume would be restricted.
A risk of direct contact with contaminated soil would continue
to exist for any person on site. This is, however, a very low
risk since the site is fenced, posted, and remote.
Alternative 12 Excavation of soil contamination; no action on
ground water;
This alternative would involve the excavation of approximately
700 cubic yards of contaminated soils in the sump and trench areas,
plus other known locations of surface or near-surface contamination,
and disposal off-site at a federally permitted facility. No,
action would be taken on the contaminated ground water at this
time until the nature of the area-wide source of chromium was
determined. Monitoring of ground water, however would be required.
Total present worth including a 30-year monitoring period is
$805,000.
-------
Table 2-2.
TECHNOLOGIES rot sou AND GKOUNMUUR CLEANUP
Component of Cleanup
Applicable Technologies
Preferred
technologies
Reason for Considering
Other technologies Less Preferable
Soil disposal/treatment
Disposal In off-site RCRA landfill
Treat soli on-slte
Incineration using a mobile Incinerator
Unproven technology
Uncertainty In the cost of Implementation
Groundwater treatment for
(a) revival of organic
contaminants '
(b) removal of chromium
Groundwater disposal
Carbon adsorption
Aeration
Coagulation/filtration treatment
Discharge treated water Into
ocean water by pipeline
f.'f
Truck treated water to Crescent City
Not effective In removing 2.4-0
Similar In cost to other alternatives.
but a potential for adverse environ-
mental Impact
Discharge treated water to surface
drainage!?
'? ' '
Truck treated water to sewer main
Similar In cost to piping to sewer
main, but extended labor charges would
be Incurred if groundwater pumping/
treating were to eiceed two years
Pipe treated water to sewer main
-------
TABLE 3. REMEDIAL ACTION ALTERNATIVES
Alternative
Remedial Action Name
Components of the Remedial Action
No action
No action on contaminated soils
or groundwater
Monitoring and site protection
Excavation of known soil
contamination, no action for
groundwater
Excavate sump and trench areas
plus other known contaminated
locations
Dispose of excavated soils 1n
the off-site RCRA landfill
No action for groundwater
Excavation of known soil con-
tamination and trucking of
treated water to Crescent City WWP
Excavate sump and trench
areas plus known contaminated
locations
Dispose of excavated soils in
off-site RCRA landfill
Pump groundwater
Treat pumped water by carbon
adsorption and
coagu1at1on/f1Itratlon
treatments
Truck treated groundwater to
Crescent City WWP
Excavation of known soil con-
tamination, and piping of
treated water to Crescent City
sewer main
Excavate sump and trench areas
plus known contaminated
locations
Dispose of excavated soils 1n
off-site RCRA landfill
Pump groundwater
Treat pumped water by carbon
adsorption and
coagulation/filtration
treatments
Pipe treated groundwater to
nearest Crescent City sewer
main
-------
TABLE 3. REMEDIAL ACTION ALTERNATIVES (concluded)
Alternative
Remedial Action Name
Components of the Remedial Action
Excavation of known soil
contamination, disposal of
treated water to surface
drainage
Excavate sump and trench
areas plus known
contaminated locations
Dispose of excavated soils in
off-site RCRA landfill
Pump gfoundwater
Treat pumped water by carbon
adsorption and
coagulation/filtration treatments
Discharge treated water to
ground for surface drainage
Excavation of entire site, .
and piping of treated water
to a sewer main
Excavate sump and trench areas
plus 1.5 ft over the entire
site
Dispose of excavated soils
off-site RCRA landfill
Pump groundwater
Treat pumped water by carbon
adsorption and
coagulation/filtration
treatments
P1pe=jtreated-groundwater to
nearest Crescent City sewer
main
-------
: Under this alternative, the source of continuing contamination
of ground water would be removed. However, the potential use of
the aquifer in the vicinity of the plume would still be adversely
affected. Removal of the contamination source would not eliminate
this problem. This alternative would not fully comply with
cleanup objectives set for this site, since it would leave in
place ground water contamination at levels higher than applicable
standards. Future well drilling in the vicinity of the site
would need to be restricted to prevent use of contaminated ground
water for supply.
Excavation and off-site removal of contaminated soils is a
proven and reliable technology which has been used at many other
hazardous waste sites. Application of stringent health and safety
requirements would help prevent potential health risks during
off-site transportation of the contaminated soils.
Alternative 13 Excavation of soil contamination; ground water
treatment and disposal via trucking to the Crescent City Wastewater
Treatment Plant:
Approximately 700 cubic yards of soils from the sump and
trench areas would be excavated. These contaminated soils would
be disposed off-site at a federally permitted facility. The
plume of contaminated ground water would be pumped from the
aquifer, and treated using carbon adsorption, coagulation, and
sand filtration technologies. The treated ground water would be
trucked to the Crescent City municipal waste water treatment
plant for additional treatment prior to disposal into the ocean
from the deep-water outfall pipe. Total present worth is estimated
at $1.41 million.
Under this alternative, the source of continuing contamination
of ground water would be removed. The treatment of ground water
using carbon adsorption, coagulation and sand filtration to appli-
cable standards would provide a high degree of public protection,
and would fully satisfy the cleanup objectives for the site.
Based on preliminary ground water modeling results, it is
estimated that extraction of contaminated ground water would
continue for approximatley two years. The cost for this alterna-
tive is therefore based on trucking treated water to the Crescent
City municipal waste water treatment plant for two years. If
extraction and treatment extended beyond two years, cost of
implementing this alternative would increase proportionally.
Under this alternative, there is a low risk of environmental
impacts due to the potential for spillage of treated water during
the trucking operation. Additionally, the labor intensive means
of transport would not fully satisfy requirements for reliability.
The spent carbon filters containing organic?, and waste y
brine containing chromium would be disposed of in a federally
approved off-site facility.
Potential health and safety concerns related to all construc-
tion activities could be addressed by implementation of proper
construction practices and stringent health and safety requirements,
-------
Alternative 14 Excavation of soil contamination; ground water
treatment and disposal via piping to the nearest sewer main;
This alternative is the same as Alternative 13, except
that the ground water would be piped to the nearest municipal
sewer main. From there it would flow to the Crescent City municipal
waste water treatment plant for additional treatment prior to
discharge from the deep-water outfall pipe. Total present worth
of this alternative would be approximately $1.41 million.
This alternative would fully satisfy the cleanup objectives
for soil and ground water contamination at the site. Off-site
disposal of contaminated soils would eliminate a source of future
contamination of ground water. .Contaminated ground water would
be treated by carbon adsorption, coagulation and sand filtration
technologies to the applicable standards and piped to the nearest
municipal sewer main (located approximately three-fourths of a
mile from the site). The contaminated ground water would
be pumped and treated until levels of contamination dropped
below the applicable standards. The spent carbon filters containing
organics, and the waste brine containing chromium would be disposed
off-site at a RCRA approved facility.
If ground water extraction should continue beyond two years,
no additional costs would be incurred since the pipeline would
already be in place.
Potential health and safety concerns related to all constructiq
activities could be addressed by implementation of proper construc-
tion practices and stringent health and safety requirements.
Alternative #5 Excavation of soil contamination; ground water
treatment and discharge to surface drainage; .
This alternative is the same as the third and fourth
alternatives except that the ground water would be treated and
piped to surface drainage in the immediate area. Total present
worth of this alternative would be approximatley $1.04 million.
This alternative-would^-meet^site-objective
the source of future ground water contamination and treating
contaminated ground water to applicable standards. The ground
water would continue to be pumped and treated until levels of
contamination drop below the applicable standards. .However, unlike
alternatives three and four, ho additional treatment of discharged
water would occur because the treated water would not be passing
through the municipal waste water treatment plant.
This alternative would be inconsistent,with^the--NorthiCo'astr
Regional Water Quality Control Board's "Water Quality Control
Plan, Klamath River Basin (IA)" July, 1975 which prohibits any
surface discharge of treated waters (see Consistency with Other
Environmental Laws section).
-------
In addition, if the treatment system were to fail over the
course of the two year extraction and treatment period, there
would be a potential for discharge of untreated water to local
surface drainage. This alternative would therefore not be as
reliable as Alternatives 13 and §4. The spent carbon filters
containing organics, and the waste brine containing chromium would
be disposed off-site at a federally approved facility.
Potential health and safety concerns related to construction
activities would be addressed by implementation of proper construc-
tion practices and stringent health and safety requirements.
Alternative 16 Excavation of entire site? ground water treatment
and disposal via piping to nearest sewer main:' ~~
This alternative exceeds applicable standards. Excavation
would occur over the entire site to a depth of 1.5 feet, in addition
to the removal of the 700 cubic yards of contaminated soil as
described in Alternatives 2,3,4 and 5. All contaminated soils
would be disposed of off-site at a federally permitted facilty.
Contaminated ground water would be extracted and treated using
carbon adsorption, coagulation and sand filtration technologies.
Treated ground water would then be piped to the nearest sewer
main. The total present worth of this alternative is estimated
at $1.9 million.
This alternative.is similar to the Alternative 14, except
that excavation of 1.5 feet over the entire site is considered
in addition to excavating the sump and trench areas. This would
provide a higher degree of public health protection than the
limited soil excavation options. Since this alternative will exceed
the soil cleanup standards, the probability of leaving any isolated
spots of contaminated soil within the site boundary would be reduced
to a negligible level.
Since this alternative involves higher volumes of excavated
soils than alternatives 2, 3,4 and 5, a greater degree of exposure
would be associated with construction activities associated with
Alternative 6. However, the excavation activities would be
expected to last less than a week for any of the alternatives, and
hence the increase in the exposure would not be significant, partic-
ularly if appropriate protection measures are taken. ....,,.
With regard to the cleanup of ground water, this alternative
would physically remove the organic and chromium contaminants to the
levels specified as cleanup objectives (applicable drinking water
standards). The spent carbon filters containing organics, and the
waste brine containing chromium would be disposed of in a federally
approved off-site facility.
-------
Summary
A summary of the evaluation of Remedial Action alternatives
is presented in Table 4. Alternatives 1 and 2 would not meet the
site objectives, nor comply with all applicable environmental
laws. Alternatives 3, 4 and 5 would adequately meet the cleanup
objectives set for the site, and alternative 6 would exceed the
cleanup objectives. The use of a pipeline in alternative 4 would
provide a simple, passive method for transporting the treated
ground water from the site to the sewer system, as opposed to
the labor and mechanically intensive transporting method under
alternative 3. Over time, alternative 4 would be more reliable.
Also, if the cleanup of contaminated ground water exceeded two
years, there would be no additional costs to operate the pipeline.
Alternative 5 would meet cleanup objectives, but would not fully
comply with the NCRWQCB's Klamath River Basin Plan. In addition,
if the treatment plant were to fail, there could be a discharge
of untreated water to local surface drainage. This is a significant
environmental impact. Alternative 6 would satisfy site cleanup
objectives but exceeds applicable standards. Since no significant
incremental benefit to public health, welfare or the environment
would be realized by excavating to 1.5 feet over the entire site,
alternative 6r would not meet the requirements for cost effectiveness
when compared to alternatives 3, 4 or 5.
COMMUNITY RELATIONS
Documents made available for public comment included the
Remedial Investigation and Feasibility Study reports. The public
comment period was held July 9 through July 30, 1985. Public
notification of the public comment period was announced two
weeks prior to the public comment period through notices in the
local newspaper. A fact sheet summarizing the contents of the
RI and FS reports was sent to the mailing list on July 9, 1985.
There was very little general public interest in the project, so
instead of holding a formal public meeting, two meetings were
held with interested County, City and State officials and the
local citizens action group. The meeting with the local citizens
action^qroupy^-the~'Fr-iend8~6f''"I>el?'Nort:e County, occurred on July
31, 1985. A meeting with Del Norte County and Crescent City
officals was held on August 1, 1985. Comments received regarding
the recommended alternative were generally favorable. All
parties emphasized the need for an additional investigation of
the area-wide chromium problem.
Of the four written sets of comments received on the Draft
Feasibility Study, three were from state or local agencies, ..and
one was from a citizens action group. Two commentor^e^^
a preference for Alternative 14, one commentor recommended
Alternative 2 (excavation of soil contamination; no action for
ground water) be implemented until the occurrence of chromium was
explained, and one commentor expressed a preference for no action.
Responses to the comments are presented in the Responsiveness
Summary attached.
-------
Table 4. Sumwry of the Evaluation of Remedial Action Alternatives
Alternative Technical Feasibility Environmental Impacts Public Health Concerns Intfltutlonal Requirements
I. No action
2. Limited soil
excavation,
no action on
groundwater
Required groundMatw
on i tor Ing procedures
aro rout In*
Cuemun equipment
and procedures
Terrestrial animals
and birds exposed to
contaminated soils
Continued potential
for exposure to
contaminated soils
and groundwater
Long-tor* groundwater
onltorlng and maintenance
of sit* Mcurlty required
Potential for advorso Risk of wiposuro to Permits required for
onvlronMantal Impact contanlnatad soils
Itlgatod. Low
environmental risk
duo to possibility
. of spill during
transportation of
contaminated soils
3. Limited soil
excavation,
trucking of
treated water
to the IMP
4. Limited sell
excavation and
piping of
treated water
to sower ejeln
Cuemin equlpMNtt and
procedures for soil
excavation. Specialized
but well-proven
equipment and procedures
for water treatment
minimized. Continued
potential for
exposure to
contaminated
groundwatar
Risks of exposure to
contaminated soils and
groundwatar minimized
transportation of
contaminated soils. EPA
manifest documentation
required
Cost
Perpetual (MM cost of
groundwater monitoring *
$35,000/yr. Total
present worth cost over
30 yi -. m $330,000
Perpetual OM cost of
groundwater monitoring =
$35,000/yr. Total
present worth cost over
30 yr. « $809,000
Total cost =
$1.23 million
Total cost =
$1.24 million
9. Limited soil
excavation and
disposal of
treated water
to surface
drainage
6. Excavation of
entire site
and piping of
treated water
to sewer main
potential for
environmental Impact
due to surface release
of contaminated.water
after being treated
Greater environmental
protection provided
against exposure to
contaminated soils.
Low environmental risk
due to possibility of
spill during
transports!JOT nf
+NPOES
permit required from NCRWQCB
for surface discharge of
treated water. Standards
for disposal to surface
waters established by
NCRMQCB's Basin Plan
would not be mat
Permits required for
transportation of
contaminated soils.
EPA manifest documentation
required
Itotal cost =
$1.08 million
Total cost =
$1.75 million
-------
CONSISTENCY WITH OTHER ENVIRONMENTAL LAWS
RCRA Subtitle C, 40 C.F.R. Part 264 and 265 contain closure
requirements for landfills and .surface impoundments that would
apply to this site. .Under RCRA, the site could not be left in
its current state without some form of remedial action. In
order to comply fully with all relevant and applicable portions
of RCRA, immobilization of the contaminants must be assured; any
off-site migration of contaminants would be unacceptable.
Excavation of known areas of soil contamination, and extraction,
and treatment of ground water to applicable standards, will assure
that contaminants will not continue to migrate off-site. Alter-
native 1 - No Action, cannot comply with RCRA because it cannot
prevent ground water from being contaminated by soils which have
been found to be contaminated.
Any applicable Occupational Safety and Health Administration
requirements will be addressed during the detailed design phase
of the selected alternative. Department of Transportation
Hazardous Material Transport Rules would be complied with during
the off-site transportation of hazardous materials for any of the
alternatives which include soil removal. EPA manifest documen-
tation would also be required. Approval of the facility owner
and the local communities to accept the contaminated soils would
also be required. These requirements apply to all but the No-
Action Alternative.
Spent carbon filters containing organics, and the waste brine
containing chromium would be disposed of in an off-site RCRA
facility. Disposal of these would require State and federal
transportation department permits for hazardous waste transport.
These requirements would apply to Alternatives 3, 4, 5 and 6.
According to the Proposed NCP, 40 C.F.R. Part 300.68 (i),
remedial actions must comply with all relevant and applicable
federal laws and regulations unless one of five exceptions apply.
None of those five exceptions apply to this site. This guidance
also specifies,that-,state standardsshall1-be-^considered"'in''determining
the appropriate remedial action. Alternative 5 does not comply
with the North Coast Regional Water Quality Control Board's
"Water Quality Control Plan, Klamath River Basin (IA)" July, 1975.
Under the plan, any surface discharge of treated waters is unac-
ceptable. Specifically, the proposed treatment of contaminated
ground water cannot achieve standards for discharge to surface
waters established by the Regional Board's Basin Plan cited
above, such as 2 ppb of 2,4-D for a 24-hour period, and zero
discharge of 2,4,5-T.
The ground water under the site is considered Class II ground
water under the EPA Ground Water Protection Strategy (GWPS). Such
a classification indicates that the water is a current or potential
source of drinking water or has other beneficial uses. The ground
water in the vicinity of the site is presently being used for
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agricultural and domestic purposes. According to the GWPS, the
goal of remedial actions for this site should be to maintain
drinking water quality or .background levels. Alternatives 3, 4,
5, and 6 fully comply with the GWPS.
Compliance with the CERCLA Offsite Policy (Nay, 1985),
would be required at -the Remedial Action stage. Under the Offsite
Policy, no offsite disposal of hazardous wastes would be allowed
at any facility not in compliance with RCRA, unless the facility
had entered into an enforceable agreement for correcting its
problems; and the disposal occured at a unit which was found
to be in compliance. During the Remedial Design phase, we will
select the RCRA approved facility to use for off-site disposal
of the contaminated soils from the Del Norte Site. Any remedial
action proposed for the site which includes off-site disposal
must comply with CERCLA Section 101 (24).
Alternative 15 would require an NPDES permit, since it
involves a discharge to a surface water of the United states.
Discharge of treated ground water, as in Alternatives 3,4 and
6 must comply with -any pretreatment limits set by the Crescent
City Waste Hater Treatment Plant. The discharge to the Waste
Water Treatment Plant should not jeopardize the plant's compliance
with the Ocean Plan limitations of its permit. Any permits
required by Del Norte County or Crescent City in conjunction
with the implementation of the recommended alternative would be
completed during the Remedial Design phase.
No other relevant or applicable federal laws, regulations,
requirements, advisories, or guidances are known that might
pertain to the remedial actions which were evaluated for this
site. Alternatives 3, 4, 5 and 6 fully comply with all
applicable Federal and State laws. However, as mentioned above,
alternative 5 does not comply with the North Coast Regional
Board's Basin Plan.
RECOMMENDED ALTERNATIVE
The recommended alternative (Alternative 14) is comprised
of the following elements:
- Excavation and removal of contaminated soils to a RCRA
approved, offsite, Class I, hazardous waste disposal
facility. ;
- Extraction of contaminated ground water.
- Treatment of ground water contaminated by organics and
pesticides by carbon adsorption.
- Disposal of spent carbon filters containing organic
contaminants to a RCRA approved, offsite, Class I,
hazardous waste disposal facility.
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- Treatment of ground water contaminated by chromium by
coagulation and sand filtration technologies.
- Disposal of chromium-rich waste brine to a RCRA approved,
offsite, Class I, hazardous waste disposal facility.
- Disposal of treated ground water by piping to the County
sewer main.
- Ground water monitoring in accordance with RCRA Part 264.
This action will address all public health concerns by
eliminating the potential for direct contact with soils contam-
inated by organics, pesticides and chromium, as well as eliminating
the potential for contamination of domestic supply wells via the
migration of the contaminant plume emanating from the on-site
federal and state laws, standards, and guidance.
The recommended alternative (Alternative 14) is consistent
with the cost effectiveness requirement of the NCP, 40 C.F.R.
Part 300.68 (j) which requires "the lowest cost alternative that
is technologically feasible and reliable and which effectively
mitigates and minimizes damage to and provides adequate protection
of public health, welfare, or the environment." The recommended
alternative also satisfies criterion (A) of CERCLA Section 101 (24),
as it is more cost-effective than the other proposed alternatives.
The components of the recommended alternative are all tech-
nically feasible and reliable, and when combined, provide an
adequate level of protection for public health, welfare and the
environment. An alternative which involved trucking of treated
water to the Crescent City Waste Water Treatment Plant was
rejected although comparable in cost with the recommended alter-
native, because it was determined to be less reliable over time.
Alternative 6 which included the excavation of 1.5 feet over the
entire site in addition to all known areas of contamination, was
rejected because it cost more and would not provide significantly
better protection of the public health, or welfare or the
environment. '
OPERATION AND'MAINTENANCE
There are no O&M requirements for the recommended alternative.
Maintenance and operation of equipment is included as part of the
remedial action alternative. The soil excavation component is
expected to be completed in less than a week and will require no
further monitoring. The ground water extraction and treatment
system is expected to attain cleanup objectives within two years.
Post cleanup monitoring eight times per year for two years to
verify that -cleanup objectives-' have^-been -mety-'vil^bW'pei: formed
as part of the remedial action program.
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SCHEDULE
Approve Remedial Action; Sept. 30, 1985
Sign Record of Decision
Transmit an Interagency Agreement to the Pending Funding
U.S. Army Corps of Engineers for Remedial
Design
' Award State Superfund Contract for Nov. 30, 1985
Remedial Design and Remedial Construction
"Transmit an Interagency Agreement with the Feb. 1, 1986
U.S. Army Corps of Engineers for
Remedial Action
" Start Remedial Action Sept. 1, 1986
* Complete Remedial Action Sept. 1, 1989
* Delete Site from the National Priorities March 1, 1990
List
FUTURE ACTIONS
Once this Record of Decision is sighed, EPA will enter into
an Interagency Agreement with the Corps of Engineers for design
of the selected remedial action. Negotiations with the State
will then begin on the State Superfund Contract. Prior to the
completion of the design of the selected remedial action, at the
time when an accurate cost estimate is available, EPA will enter
into an Interagency Agreement with the Corps of Engineers for
construction of the remedial action. Construction is expected to
take approximately two months. Within two years, extraction and
treatment of ground water is expected to be completed. An
additional two years of monitoring will precede the deletion of
the site from the National Priorities List.
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1.0 DEL NORTE COUNTY
PESTICIDE STORAGE AREA SITE
RESPONSIVENESS SUMMARY
1.1 INTRODUCTION
This responsiveness summary describes EPA's responses to concerns and
comments raised by state and local officials and community members about
Superfund activities and proposed remedial alternatives at the Del Norte
County Pesticide Storage Area Site. It also provides a brief history of
community Involvement at the site and community relations activities
conducted through July 30, 1985, the close of the public comment period
on the Draft Feasibility Study report. This responsiveness summary 1s
organized as follows:
A. Background of Community Involvement and Concerns
B. Summary of Major Comments Received During the Public Comment
Period and EPA Responses
C. Remaining Public Concerns
Section B. 1s based.on written and oral comments received by EPA during
the public comment period. This section categorizes public comments by
their subject matter. The major categories are remedial alternative
preferences, water quality concerns, technical comments on the proposed
alternatives, enforcement questions, and public participation comments.
The responsiveness summary also "includes, as Attachment A, copies of
comment letters submitted to EPA during the comment period.
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1.1.1 BACKGROUND OF COMMUNITY INVOLVEMENT AND CONCERNS
Del Norte County officials, the California Department of Health Services
(DOHS). and the North Coast Regional Hater Quality Control Board
(NCRWQCB) have been the ones most Involved with the site, starting 1n
1979 when the NCRWQCB Issued a cleanup and abatement order to the
County. Most newspaper coverage of the site has focused on activities of
the NCRWQCB and Del Norte County Supervisors related to the site. The
County and some residents In the community have been most concerned with
the County's share of site cleanup costs because of County financial
problems. The Friends of Del Norte County, an environmental Interest
group, has followed activities at the site and the recent RI/FS. This
group 1s concerned about where site contaminants will be disposed of, and
how EPA will address the problem of chromium-contaminated groundwater.
The following 1s a summary of community relations activities conducted 1n
connection with the Del Norte Site:
EPA conducted community Interviews and established a site
mailing 11st (March 1985).
EPA prepared Final Community Relations Plan (June 1984).
EPA and OOHS briefed representatives from Del Norte County,
Crescent City; NCRWQCB, U.S. Congressman Bosco's office, and
California
EPA distributed fact sheet describing proposed RI/FS activities
(August 1984). - , ;^
Two letters were distributed to the community describing EPA
activities at the site: one from the EPA Project Officer and
one from the Community Relations Coordinator (February 1985).
-------
Notices of the public comment period on the Draft Feasibility
Study report were announced In.the Del Norte Triplicate and
Eureka Times Standard (June 22 and 25, 1985, respectively).
EPA distributed a second fact sheet that described the results
of the remedial Investigation, presented the remedial
alternatives proposed In the Draft Feasibility Study report, and
announced the public comment period (July 1985).
Public comment period was held from July 9 to 30, 1985.
EPA met with DOHS and NCRWQCB representatives (July 29, 1985)
and The Friends of Del Norte County (July 31, 1985) to discuss
proposed alternatives. On August 1, 1985, EPA staff met with
representatives from Del Norte County, Crescent City. NCRWQCB,
and DOHS. Representatives from The Friends of Del Norte County,
the Del Norte Triplicate, and KPOD Radio also attended this
meeting.
1.1.2 SUMMARY OF RESPONSES TO COMMENTS RECEIVED DURING THE PUBLIC
COMMENT PERIOD
Comments raised during the Del Norte Site public comment period on the
Draft Feasibility Study report are summarized briefly below. The comment
period was held from Ju.ly 9 to July 30, 1985. During the comment period,
EPA briefed state and local officials and The Friends of Del Norte County
representatives. Oral comments from these briefings are Included 1n this
section. Public comments and EPA responses are organized Into the
following categories: .
Remedial alternative preferences
Water quality comments
Technical comments on the proposed alternatives
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Enforcement questions
Public participation comments
Questions and comments unrelated to the Del Norte Site
-
1.2 REMEDIAL ALTERNATIVE PREFERENCES
1. In written comments, NCRWQCB AND OOHS recommended modifications to
the remedial alternatives proposed 1n the Draft Feasibility Study
report. The NCRWQCB preferred the alternative Involving limited soil
excavation, water treatment, and disposal to a sewer main with the
following revisions: (1) Extent of soil excavation should be
determined by thorough sampling and analysis during design; (2)
treated groundwater should be piped to the nearest Crescent City
sewer main; and (3) during the startup of the wastewater treatment
plant, treated water should be contained In a holding tank and
analyzed for contaminant levels before being discharged to the sewer
main. DOHS also recommended that additional soil testing be
conducted during the design phase to more closely define the location
of contaminated soils prior to remedial action. DOHS supports
discharge of treated wastewater to the municipality's sanitation
system.
EPA Response: The Final Feasibility Study report reflects these
modifications 1n Alternatives 4 and 6. During remedial design, soil
excavation and sample analyses will be done 1n order to further
define soil contamination. ..Alternatives 4 and 6 specify piping -
treated water td a sewer main. Alternatives 3 through 6 specify that
treated water should be contained In a holding tank for sampling and
analyses during startup of the treatment processes. . ....
2. The Friends of Del Norte County Indicated a preference for
Alternative 2, excavation of known soil contamination and no
groundwater treatment, untl1^EPA'aoha! thoroughly evaluates chromium
contamination of groundwater. Following EPA's explanation given
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below, representatives of The Friends of Del Norte County Indicated
their support of the recommended alternative.
EPA Response; In a meeting with The Friends of Del Norte County, EPA
explained that the chromium Issue will be resolved by a separate
study.
3. During a briefing for County and City officials. County officials
expressed a preference for Alternative 1, the no-action alternative,
based on Its low cost. They suggested zoning the site as restricted
property. Following EPA response described below, the County stated
support for Alternative 4.
EPA Response: Federal and state governments are required by law to
protect the public health, surface water, and groundwater of the
state. Selection of the no-action alternative would degrade rather
than protect the groundwater resources 1n the vicinity of the site.
EPA bases Its selection of the remedial alternative on several
factors 1n addition to cost.
1.3 MATER QUALITY COMMENTS
1. In a written comment, The Friends of Del Norte County commented that
water and soil samples 1n the vicinity of a monitoring well (HW-5)
located upgradlent from the drum storage site may Indicate that some
materials had been transferred out of the designated storage area or
that unauthorized dumping of pesticides, fumlgants, and toxic
materials may have occurred on lands controlled by the Del Norte
County Agricultural Commissioner.
. ' . . . . , ';.-;-r\ .'.*''. - '- -' '
EPA Response; As stated 1n the draft Remedial Investigation report
(July 8, 1985), groundwater samples from MW-5 and nearby auger hole
13 were found to contain limited amounts of 2,4-0. Sroundwater
elevations show that MW-5 1s hydraullcally upgradlent of the source
-------
of contamination on-s1te. Therefore, the source of the 2,4-D
detected 1n samples taken from MW-5 1s not believed to be from the
pesticide storage site. This conclusion 1s supported by the lack of
2,4-0 In the auger holes located between the site and NW-5. The area
Immediately surrounding Mf-5 has been extensively disturbed by
trenching, the result of animal burial and.other activities by the
Del Norte County Agricultural Commissioner's Office. It Is possible
that during these activities, pesticide-contaminated materials may
have been placed 1n the trenches, as evidenced by the presence of a
few contaminants 1n a background soil sample taken near NW-5.
2. Both County and City officials and members of The Friends of Del
Norte County were concerned about chromium contamination 1n the
groundwater 1n the vicinity of the site.
Four of the six remedial action alternatives specify that the
groundwater be treated. The groundwater will be treated for chromium
and organic* for the length of time required to clean up the organics
contamination. Organic; removal will be accomplished by carbon
adsorption. Chromium removal will be by a combination
coagulation/filtration process since 1t has been determined that the
chromium 1s 1n participate form. Further sampling during the
remedial design stage will verify the form (hexavalent or trlvalent)
of chromium. EPA Intends to address the source and size of the
chromium contamination plume 1n another study, separate from the Del
Norte S1tei1nvest1gat1oniF^~A^
contamination 1s not known.
3. Del Norte County and The Friends of Del Norte County representatives
provided suggestions as to the possible sources of chromium
contamination In the area, such as past Military activities In the
area; prev1ous.m1H1ng operations located adjacent ;to Dead Lake;- past
and present uses of the area by the County airport; or past and
present uses of the area as an Illegal dumping ground.
-------
EPA Response; EPA acknowledges the receipt of this Information and
will pursue these possibilities as part of the chromium Investigation.
1.4 TECHNICAL COMMENTS ON THE PROPOSED REMEDIAL ALTERNATIVES
1. A letter from the Del Norte County Planning Department questioned the
cost of monitoring the site under Alternative 1 In light of the
conclusion 1n the Draft Feasibility Study report that there 1s a low
likelihood of direct contact with contaminated soils and contaminated
water reaching domestic wells.
EPA Response; As stated In the Draft Feasibility Study report.
Alternative 1 provides for no soil removal and no groundwater
treatment, and quarterly groundwater monitoring for a minimum of
thirty years. Well monitoring would be required to detect plume
migration through the aquifer. Groundwater resources 1n the site
vicinity are contaminated. Selection of the no-action alternative
would degrade rather than protect the groundwater resources 1n the
vicinity of the site.
2. At a meeting with EPA, both County and DOHS representatives
questioned the environmental Impacts of the discharge of treated
water to surface drainage.
EPA Response; 'Environmental Impacts on surface drainage may result
from the discharge of untreated water during a period of treatment
plant failure. The Final Feasibility Study report Incorporates this
Impact Into Alternative 5.
3. The Del Norte County Planning Department Indicated that a variety of
City, County, and State permits will be required for the
Implementation of the remedial alternative.
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EPA Response; EPA will attempt to meet the Intent of all state and
local regulations which may apply to the remedial action chosen.
1.5 ENFORCEMENT QUESTIONS
1. At a meeting with EPA, Del Norte County representatives expressed
concern about the County's liability for cleanup costs. .
EPA Response; At this t1«e, EPA Is continuing to evaluate Its
enforcement position with respect to the County.
2. The Friends of Del Norte County and Del Norte County representatives
Inquired about Identification of and negotiations with Potentially
Responsible Parties (PRPs). The Friends of Del Norte County were
Interested 1n the availability of an enforcement-confidential 11st of
PRPs 1f EPA determined that these parties were not liable for cleanup
costs.
\
EPA Response; According to EPA policy, this Information 1s available
to the public and may be requested by writing to the Regional Office
at any time.
1.6 PUBLIC PARTICIPATION COMMENTS
At the August 1..1985, briefing 1n Crescent City, a representative of
the Del Norte Triplicate requested that EPA,g1 ve * brlef-1 ng;ito-North*"
Coast newspapers and radio stations on the status of all sites In
northern California.
EPA Response; This type of media briefing 1s a special request that
would be best directed to the EPA Office of External Affairs.
215 Fremont St., San Francisco, California, the Office of External
Affairs was Informed of this request by Superfund Program staff.
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1.7 EPA RESPONSES TO COMMENTS UNRELATED TO THE DEL NORTE SITE
1. A letter from The Friends of Del Norte County questioned where
hazardous wastes generated withIn the County are being transported
and what agency regulates the Crescent City Landfill.
EPA Response: The Individual generators of hazardous wastes can send
their waste to whatever approved site they choose. Information from
manifest forms (stating the waste and disposal site) may be obtained
from the Toxic Substances Control Division of the Northern California
Section of OOHS. The NCRWQCB routinely samples monitoring wells at
the Crescent City Landfill, which 1s presently not 1ri compliance with
State Haste Discharge Requirements.
2. According to the Remedial Investigation report, 1150 drums from the
Del Norte Site were transferred to sections of the Crescent City
Landfill. However, members of The Friends of Del Norte County said
that there 1s no Indication that the NCRWQCB has made any checks to
ensure that those areas are free of site contaminants. They also
asked about the fate of 3 barrels of hazardous materials once under
the control of the County Agricultural Commissioner.
EPA Response; The 1150 drums ultimately disposed of at the Crescent
City Landfill were certified by the County Agricultural Commissioner
as either having been adequately rinsed prior to storage at the Del
Norte Site or having been open to the elements and adequately rinsed
by rainwater. Regarding the 3 barrels of hazardous materials, on
November 17, 1963, the barrels were shipped to a disposal site 1n
King City, California. ;
1.8 REMAINING PUBLIC CONCERNS
The major public concern Is contamination of the groundwater with
chromium. During the remedial design phase, further soil and water
-------
sampling will verify the form (hexavalent or trlvalent) of chromium.
Hexavalent chromium 1s much more toxic than trlvalent chromium.
Following the additional analyses, EPA will make a determination as
to further Investigation of chromium contamination. If hexavalent
chromium 1s present, EPA should anticipate community Inquiries about
the chromium contamination and possible health effects. Another
ongoing concern 1n the community Is the liability of the County for
cleanup costs. EPA should maintain contact with NCRWQCB. Del Norte
County, and The Friends of Del Norte County representatives on the
chromium Issue, enforcement, and the schedule for the remedial action.
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Attachment A
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STAfE OF CALIFORNIA CEORQC OEUKMEJIAM.
CALIFORNIA REGIONAL WATER QUALITY CONTROL BOAR&-
NORTH COAST REGION
1000 COODINCTOWN CENTER
SANTA ROSA. CALIFORNIA BS401
fhont: 707-S76-MJO .
August 9, 1985 '-.-'
Ms. Hlchele Dermer .
Toxics and Waste Management Division ;
U.S. Environmental Protection Agency
Hal) Code T-4-3
215 Fremont Street
San Francisco. CA 94105
Dear Ms. Dermert .
The draft Feasibility Study for the Del Norte County Pesticide Storage
Area dated July 6, 1965. has been reviewed. The following recommendations
are based on this review and the clarification of specific points
established during our meeting on July 29. 19B5. with the Department of
Health Services and woodward-Clyde Consultants.
The remedial action alternatives that we prefer along with additional
considerations are as follows:
1. Limited soil excavation to include excavation of the sump and
trench areas along with other areas of identified contamination.
A thorough sampling and analysis of soils during the design phase
will serve as a basis for determining the extent of contamination
and excavation.
2. Pump and treat the contaminated groundwater as proposed and
discharge the treated water to the nearest Crescent City sewer
main via a pipeline. The nearest sewer main Is located on Pebble
Beach Drive, approximately 5800 feet from the site.
We prefer the above alternatives for«the-following reasbnsl
1. The high cost associated with the removal, transport, and disposal
of soil can be minimized by Identifying and removing only the
contaminated soils. . ,
2. The discharge of treated wastewaters (treated groundwater) to
surface or groundwaters of the State Is not an acceptable
alternative. The proposed treatment cannot achieve standards for
discharge to surface waters established by the Regional Board's-"
Basin Plan; I.e., 24-hour average of 2 ppb for 2,4-D and zero
discharge for 2.4,5-T. Discharge to the sewer main will provide
additional treatment and greater than 100 times dilution before
discharge to the ocean.
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Ms. Hlchele Dermer
Page 2 -
August 9. 1985 ,
3. The use of a. pipe Tine provides a simple, passive method for
transporting the treated groundwater from the site to the City's
ewer system. Installation of the pipeline will probably cost
significantly less than trucking the treated groundwater, and It
will eliminate the potential for labor and Mechanical problems.
Also, If the cleanup takes longer than the predicted two years,
there will be no additional costs to operate the pipeline.
In addition to the acltlvltes already detailed to carry out the above
alternative* It will be necessary to provide facilities to hold the
treated grounovater In order that It can be analyzed for contaminant
levels before It Is released. This batching procedure awst be continued
until the groundwater treatment facility Is operating In a consistent and
satisfactory manner.
If you have any questions regarding the above, please contact me.
Sincerely,
'Charles S. Greene
Associate Land and
Water Use Analyst
cct Mr. Dave Gaboury
Woodward-Clyde Consultants
I Walnut Creek Center
1000 Pringle Avenue
Walnut Creek. CA 94596
Friends of Del Norte County
P.O. Box 229
Gasquet. CA 95543-
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The friends of Del NorteGouty
P.O. Bex 225 Gtqiirt, fcKfomii 95S4S
July 30, 1985
Michele Dermer .... ; :, -. -'.' .,-.: v /.-'; ;' .y-'..-.-;' - .."'"..:' .
Project Manager .
O.S. EPA, (T-4-3)
215 Fremont Street
San Francisco, CA 94105
SUBJECTt Comments on Del Morte County Pesticide Storage Site
draft Remedial Investigation ft Feasibility Study
The Friends of Del Norte County have reviewed the draft
Remedial Investigation (RI) and Feasibility Study (FS) for the
Del Norte County Pesticide Storage Area "Superfund* Site. We
commend the EPA for assuming'responsibility for cleaning up this
site after our local officials pleaded lack of funds and declined
to clean np the contamination they either generated or allowed to
occur, we offer the following comments on your draft RI ft FS.
We believe that immediate action should be taken to excavai
the known locations of surface and near-surface pesticide
contamination for disposal off-site at a federally permitted
facility but, that treatment of contaminated groundwater should
be deffered until the cause and extent of area-wide chromium
contamination is determined. Your July '65 'Fact Sheet*
identifies such a choice as Alternative |2s the FS's Alternative
12 does not imply that action will eventually be taken to remove
and treat pesticide contaminated groundwater. The FS discussions
of alternatives 3:6 indicate that removal of chromium
complicates the treatment of pesticide contaminated groundwater;
on ce the ch r omi urn si tua tlbn*-t§;- f u 1 ly undef r;s tbod ~we - wou 1d ~no t be " -
surprised to find out that pesticides complicate the treatment of
chromium contaminated groundwater.
The revelation that chromium and other petals are present in
both the soil and groundwater surrounding the Pesticide Storage
Area greatly distresses us. We urge the EPA to determine as
rapidly as possible if the chromium concentrations observed are
of trivalent or hexavalent chromium. We feel that if bexavalent
chromium is present at unacceptable levels in the present --
onitoring wells that the all of the airport property should be
checked so that an adequate riak assessment can be performed.
Since we expect that EPA will eventually treat and dispose
of contaminated groundwater in the Pesticide Storage Area ft
McNamara Field complex it is appropriate to comment thatin ouj|
viewtrucking of treated wastewater to the Crescent City
deep-water outfall is the prefered option for final disposal o^
Friends of Del Norte County, P.O. Box 229, Gasquet, CA 95543
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FDNC/EPA(Dermer)- 07/30/85 - Page 2
such fluids. Zt is apparently the cheapest option that does not
unduly alter the present surface/groundvater regime of the area.
It should have the lowest probability of unexpected
cooplications.
Finally, we must admit to aone dismay at the failure of the
PA to evaluate all possible contamination sites that have
resulted fro* the activities connected with the operation of Del
Morte County** Pesticide Container Storage Urea. Section 1.1.2,
Site Closure^ of the Hi states that 1,150 drums vere transfered
to special sections of the Crescent City Landfill; however, there
is no indication that any checks have been Bade to insure that
those areas are free of contamination by the sane materials that
pollute the 'Superfund* site. The HI, Section 1.1.2, also
reveals that 3 drums of hasardous Material from the site have
remained under the control of the County Agricultural
Commissioner for over 3 1/2 years, apparently still awaiting
shipment to a Claas I disposal site. Water and soil samples in
the vicinity of MW-5, up-gradient from the acknowledged storage
site, show that some material may have been transferred out of the
designated area or that 'unauthorised* dumping of pesticides,
fumigants, and toxic material may have occured on lands controled
by the County Agricultural Commissioner. (It may be pertinent to
point out that this county baa never had an SPCA; all animial
control functions here are performed by the Agriculture
Department^) Given the track record of our Agriculture
Department with respect to the authorised pesticide container
storage site, we feel strongly that all opportunitiea for
possible aoil or groundwater contamination resulting from its
existence should be completely checked out.
We appreciate the opportunity to comment on EPA'a draft RI
and PS on the Del Norte County Pesticide Storage Area. We hope
that our comments will assist you in developing a final set of
studies that adequately address all the man-induced contamination
of the aoil and groundwater in the vicinity of HcNamara Field
and the Del Norte County Agricultural Commissioner's area of
responsibility.
erely,
Martin C. Kelly
President
Friends of Del Morte County, p.p. Box 229, Gaaquet, CA 9SS43
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COUNTY OF DEL NORTE
PUBLIC WORKS BUILDING
.700FITTHST.
CRESCENT CITY. CALIFORNIA 05531
July 30, 1985
PLANNINC DEPARTMENT ; . .' ' .:;.' ',-:-'. /". .-v";;;' -,.;'.;..,-'
Michele Denser ;
Project Manager
U.S. EPA (T-4-3)
215 Fremont Street
San Francisco, CA 94105
BE: Del Norte County Pesticide Storage Area Site
Feasibility Study
Dear Ms. Dermer: '
Yesterday X returned from a vacation and have found the
above referenced document on ay desk for review and comment.
In order to meet your public comment period my comments are
prepared without benefit of the Board of Supervisors and
Planning Commission review. Additionally, my comments may
have already been addressed in previous correspondence not
received by this office as our involvement has been quite
limited. .
Our comments are as follows:
1. Under all the alternatives identified who bears the
financial cost? This County is quite limited in its
financial abilities and our financial constraints are
"
2. On Page 1-15 the report states that the prevention of
groundwater leaching is the most sensitive criteria
for site cleanup. Further on, the report states that
the treatment of extracted groundwater for chromium
would have little effect on the continued "contami-
nation" of groundwater since extracted groundwater
will be replaced by chromium-contaminated groundwater
from^the surrounding area. The report refers to the, ___ ....
source of this chromium contamination as previous
land use (RI pg. ix) . Would the continued monitoring
in Alternative One include identifying the source of
the chromium contamination and identify any action, if
necessary, appropriate to remedy the contamination?
If not, does EPA propose to address the chromium contami-
nation further than this report?
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Michele Dermer/ U.S. EPA (T-4-3)
July 30, 1985
Page Two
3. The prior land use at the project site was under the
direction of the Secretary of the Navy. To date we
have no specific information which would explain in
any detail the Navy1* activity at the project site.
As a fellow Federal agency you say be able to obtain
information which could explain any of their activity
and any source of potential chromium contamination*.
4. On Page 4-2 the report states that the likelihood
of direct contact with contaminated soils and the
likelihood of contaminated water reaching domestic
wells is considered low, what are the costs involved
with monitoring under Alternative One providing to the
involved agencies?
5. Alternative Five provides that the treated ground water
would be discharged to surface drainage. What drainage
course would be used and could a nap of the route of the
drainage course be provided? Mill there be any antici-
~ pated impacts on wildlife, domestic animals or riparian
and wetland vegetation?
. Assuming excavation of the site, will the site be
backfilled and will the area be continued to be
monitored? What use, if any, will the site.be avail-
able for after backfill?
7. A local grading permit may be required and a Coastal
Consistency determination by the State Coastal Office
may be applicable.
The report appears to down-play Alternative One as a viable
alternative. Under the circumstances involved it appears that
it may have genuine merit that should be more carefully considered
by your agency.
Thank you for this opportunity to
ERNEST PERRY,
Director of B
EP/db and Planning
CC: Board of Supervisors
Planning Commission :
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tTATj Of CMffOtMl*MUiTH AND wn>AM AOINCf CtOtOt OtUKMtMAN.
DEPARTMENT OF HEALTH SERVICES
714/744 > STttIT .
SACtAMfNJO. C* *M14
(916) 324-7773
Mr. Keith Takata
U.S. Environmental Protection ;
Agency, Region 9
215 Fremont Street ' ' , : ...: ' "; "','' ;'',:' ' :: -'- . ''-..
San Francleco, CA 94105
Dear Hr. Takatas
DEL RORTE COUNTY PESTICIDES FEASIBILITY STUDY, RECOtHENDATION FOR
REMEDIAL ACTION. j :
-.**' ' : "
The Department of Health Services has reviewed the alternatives for
Del Rorte County pesticides storage site contained in the July 6, 1985
draft Feasibility Study (FS). Six alternatives are suggested to
handle the contaminated soil and the groundwater contamination.
Generally, the soil contamination consists of organic chemicals and
exists in s sump area and several former drum storage areas. However,
the groundwater la contaminated with several organ!ca and hexavalent
chromium and extends beyond the site. Apparently the chromium is
coming from outside sources.
The six alternatives discussed in the FS are summarised below:
o no action well monitoring only - $330,000 present worth;
o limited excavation no action on groundwater - $796,000 preaent
worth; . .
o limited soil excavation, water treatment and disposal (treatment
using carbon absorption and trucking water to Cresoent City Waste
Water Treatment Plant) - $141 -millioni
o limited soil excavation, water treatment and disposal. Same as
abovebut water trucked to nearest sewer manhole $1.41 million;
o limited soil excavation, water treatment sad disposal. Same as
above, but short outfall to nearby drainage course. Rational
Pollution Discharge Elimination System permit would be required
$1.04
excavate entire site to 1 1/2 feet and all hot spots, treat water
and discharge to the local drainage course - $1.56 Billion.
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Mr. Keith Takata . AUP20J90IJ
Page 2
Based on our review of the problem and consideration of the above
alternatives, the Department would like to recommend a different
approach. Based on reviewing both the TS and the Remedial
Investigation it appears that insufficient area characterization
exists to designate a 1-1/2 foot excavation depth over the entire
site. However, cental nine tl on appears to exist on the surface
throughout the site. In view of the approximately $500,000 extra
cost for the 1-1/2 foot excavation, it would seem prudent to
perform additional testing prior to final design to determine the
location of contaminants.
The Department supports groundwster treatment for both organic* and
chromium. Further, the Department supports a dlaeharge of the treated
wastewater disposal to the municipality's sanitary system because of
uncertainty over the length of pumping time.
If you have any questions please call Mr. Steven Vlanl of my staff
(916) 324-2444.
Sincerely,
Thomas £. Bailey, Chief
Program Management Section
Toxic Substances Control Division
cc: Michel Derner, EPA
Bfevid Gaboury, Woodward-Clyde Associates
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