United States
Environmental Protection
Agency
Office of'
Emergency and
Remedial Response
EPA/ROD/R09-89/037
September 1989
Superfund
Record of Decision
Kopper's (Oroville Plant), CA
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50272-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/ROD/R09-89/037
X Recipient1* Accee*ion No.
4. TlBeandSubtJo*
SUPERFUND RECORD OF DECISION
'oppers (Oroville Plant), CA
irst Remedial Action - Final
5. Report Data
09/13/89
8. Performing Organization Rept No.
9. Pertoimlng Organization Name and Addree*
10. ProfecVTuk/Work Unit No.
11. Contnct(C) or Grant(G) No.
(C)
(G)
12. Sponaorlng Organization Nun* and Addree*
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
13. Type of Report ft Period Covered
800/000
14.
15. Supplementary Note*
18. Abetfact (Limit: 200 word*)
The Koppers (Oroville Plant) site is a 200-acre operating wood treating plant in Butte
County, Calijfornia, just south of Oroville. The site is bordered on the west by a
Louisiana-Pacific Corporation facility, which is also a Superfund site, and lies within
the floodplain of the Feather River, which runs 3,000 feet to the east. Land use in the
"Vcinity of the site is mixed agricultural, residential, commercial, and industrial.
hough there is a history of wood treating operations at the site, wood treating
erations were greatly expanded in 1955 when Koppers Company, Inc. became the owner and
operator. Chemical preservatives including pentachlophenol (PCP), creosote, and
chlorinated copper arsenate solution have been used in the wood treating processes.
Wastewater discharge and other site activities have resulted in contamination of unlined
ponds, soil, and debris. In 1971 PCP was detected in onsite ground water and, in 1972,
in residential wells to the southwest. Pursuant to a State order, Koppers conducted
cleanup activities from 1973-74, including ground water pumping and discharge to spray
fields and offsite disposal of contaminated debris, and process changes, including
construction of a wastewater treatment plant. In 1986 Koppers provided an alternate
water supply for domestic uses to affected residents. In 1987 an explosion and fire
occurred at a PCP wood treatment process facility prompting EPA to issue a removal order
requiring cleanup of fire debris, and removal and stabilization (Continued on next page)
17. Document Analymta a. Descriptor*
Record of Decision - Koppers (Oroville Plant), CA
First Remedial Action - Final
Contaminated Media: soil, gw
Key Contaminants: VOCs (benzene, toluene, xylenes), other organics (PAHs, PCP,
dioxins/furans), metals (arsenic, chromium)
b. Mentfflerm/Open-Ended Term*
'. COSATI Reid/Group
Uabifty SUUment
19. Security da** (IN* Report)
None
20. Security d*M(TM* Page)
None
21. No. of Page*
73
22. Price
(Sa»ANSI-Z3a.18)
S**> Jnttuctfora on fl»t*ma»
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-15)
Department of Commerce
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EPA/ROD/R09-89/037
Koppers (Oroville Plant), CA
Abstract (Continued)
of surface soil. This Record of Decision addresses the remaining contamination in onsite
soil, and ground water affected by site contamination. The primary contaminants of
concern affecting the soil and ground water are VOCs including toluene, xylenes, and
benzene; other organics including PAHs, PCP, and dioxins/furans; and metals including
arsenic and chromium.
The selected remedial action for this site includes a soil component and a ground water
component. The soil remedy includes four discrete soil treatment areas: in situ
biodegradation of 110,000 cubic yards of PCP-contaminated soil; excavation and soil
washing of 200,000 cubic yards of soil contaminated with wood treating wastes with
redisposal of treated soil onsite and treatment of residual contamination in the washing
fluid in an onsite treatment facility; installation of a low permeability cap over the
wood treating process area and downgradient extraction wells with future treatment of
20,000 cubic yards of contaminated soil beneath this area as soil becomes accessible
during equipment change or ceasing of operations; and excavation and chemical fixation of
4,000 cubic yards of soil contaminated with metals, followed by onsite disposal. The
ground water remedy includes pumping and treatment of approximately 22,000,000 cubic
yards of ground water using activated carbon, and reinjection of treated waste to the
ground water; and formalization of the provision of an existing alternate water supply
and extension, if needed, of the water supply during implementation of the remedy. The
estimated present worth cost for this remedial action is $77,700,000, which includes an
estimated present worth O&M cost of $37,100,000.
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Declaration
SITE NAME AND LOCATION
Koppers Company, Inc.
Oroville, CA
STATEMENT OF BASIS AND PURPOSE
This decision document presents selected soil and ground
water remedial actions for the Koppers site in Oroville, Califor-
nia, developed in accordance with the Comprehensive Environmental
Response, Compensation and Liability Act, as amended by the Su-
perfund Amendments and Reauthorization Act (CERCLA), and to the
extent practicable, the National Contingency Plan. This is con-
sidered an Operable Unit Record of Decision (ROD). Investigatory
work related to this site is ongoing, and could potentially lead
to additional CERCLA actions, or actions pursuant to other
statutory authority, at this site. This decision is based on the
administrative record for this site.
The State of California has concurred with the selected
remedy.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from
this site, if not addressed by implementing the response action
selected in this ROD, may present an imminent and substantial en-
dangerment to public health, welfare, and the environment.
DESCRIPTION OF THE REMEDY
This remedy includes EPA's first remedial actions selected
for this site and addresses the documented public health threats
from the site contamination. Actions have been selected to ad-
dress onsite soils, on and offsite ground water, and the con-
tinuation of an alternative water supply until the ground water
cleanup meets EPA's remedial objectives.
The selected soil remedy includes:
- In situ biodegradation of approximately 100,000 cubic
yards of soil contaminated primarily with pentachlorophenol.
- Excavation and treatment by soil washing of approximately
200,000 cubic yards of soil contaminated with a variety of wood
treating wastes. The treated soil will be redisposed of on the
site. Residual contamination in the washing fluid will be
treated in an onsite waste water treatment facility.
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- Installation of a low permeability cap over the currently
active wood treating process area, along with the installation of
extraction wells downgradient of this area to prevent the migra-
tion of contamination into the surrounding ground water. When
contaminated soil beneath the process area is accessible, either
when process equipment is replaced or when wood treating opera-
tions cease, this contaminated soil will be remediated to the
same remedial objectives as the aforementioned two soil units.
- Excavation and treatment by chemical fixation of soils
contaminated with metals used in the wood treating processes.
The treated soils will be disposed of on the site.
The selected ground water remedy includes:
- Extraction of contaminated ground water, treatment using
activated carlxpn, and reinjection of treated water to the ground
water. Contaminated residuals from the carbon treatment will be
treated by biodegradation.
- Formal izat ion of the provision of an alternative water
supply to residents with contaminated wells during implementation
of the remedy. (An alternative water supply has been provided by
Koppers since early 1986.) Water provided will be~ sufficient in
volume to preclude use of contaminated residential wells for any
purpose, and to prevent the use of wells that would adversely af-
the pump and treat remediation of contaminated ground water.
Site specific treatability studies have shown that activated
carbon sucessfully removes contamination from ground water.
Other selected treatment methods will be tested on site soils and
groundwater during remedial design to demonstrate their effec-
tiveness.
The aforementioned actions will address all documented
threats from the site, litvestigatory work is currently underway
on an additional area that might result in future response ac-
tions under CERCLA or other regulatory authority. These involve
air emissions from wood treating operations at the site.
STATUTORY DETERMINATIONS
The selected remedies are protective of human health and the
environment, comply with Federal and State requirements that are
legally applicable or relevant and appropriate to the remedial
actions, and are cost-effective. These remedies utilize per-
manent solutions and alternative treatment technologies to the
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-3-
maximum extent practicable and satisfy the statutory preference
for remedies that employ treatment that reduces toxicity,
mobility, or volume as a principal element. As this remedy in-
volves treatment that will take approximately twenty to thirty
years to reach remedial objectives, a review will be conducted
every five years after commencement of remedial actions to ensure
that the remedy continues to provide adequate protection of human
health and the environment.
Daniel W. McGovern*^ Date
Regional Administrator
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Decision Summary
1.0 Site Name, Location. Description
The Koppers Company site is located in Butte County just
south of the city limits of Oroville, California. (See Figure
1-1, Site Location Map) The facility is a 200-acre operating
wood treating plant. The Koppers site is bordered on the west by
the Louisiana-Pacific Corporation facility, which is also on
EPA's Superfund National Priorities List.
The western boundary of the Koppers site is about 3000 feet
east of the Feather River. The site lies in the Feather River
flood plain, which is approximately 2.7 miles wide near the site.
The site lies about 145 feet above sea level, while the Feather
river is about 130 feet above sea level. Gold mining dredge
operations occurred in the early 1900's in the area of the Kop-
pers site. Tailing piles from this dredging remain on the north-
ern part of the site. These piles rise 150 feet above sea level.
To the east and southeast of the plant are hills which rise 250
to 300 feet above sea level.
Surface water runoff flows from the Koppers site to the west
onto the neighboring Louisiana-Pacific facility. This water
flows primarily in a ditch between the two sites, and through a
channel which traverses the Koppers site's spray fields in a
^ci-i<=rally northeast to southwest direction.
The geology underlying the site consists of gravels, sands,
and clays that were deposited by the Feather and ancestral
Feather River systems. Several interconnected aquifer zones have
been defined on and off the site. The regional ground water flow
is generally to the south, with upper aquifers demonstrating some
southwesterly components.
Land use in the vicinity of the site is mixed agricultural,
residential, commercial, and industrial. One- to five-acre farms
exist, and much of the produce and livestock is raised for home
use and not sold commercially. Residential areas are located to
the south, southeast, west, and northeast of the site. Three
schools are located within a two-mile radius of the site.
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'
CALIFORNIA
^County Health
\ ICenter Library
:|:|Jtxijk:-:-"-
Oroville
k
San Francisco
m
OROVIUE
OROVILLE STATE
WILDLIFE AREA
Koppers Wood
reating Site
PALERMO
FIGURE 1-1
SITE LOCATION MAP
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2.0 Site and Enforcement History
;! V'lvfiU. ..
During the early 1900's the area around the Koppers site was
used for gold mining dredge operations. From approximately 1920
to approximately 1948, Hutchison Lumber Mill was located at the
site. From approximately 1948 to 1955, the site was owned and
operated by National Wood Treating Company. In 1955, Koppers be-
came the owner and operator of the site, and expanded wood treat-
ing operations. Contamination was first documented in onsite
ground water in 1971. The contribution of Hutchison Lumber Mill
and National Wood Treating Company to the pollution problem at
the Koppers site is unknown. Koppers has not identified these
other companies as being liable for causing site contamination.
Since 1955 Koppers has operated several wood treating
processes at the site. Chemical preservatives including pen-
tachlophenol, creosote, and chromated copper arsenate (CCA) solu-
tion, have been applied to wood in pressurized treatment vessels.
Treated wood product uses include utility poles, railroad ties,
and building foundations. .........
Wastewater from the creosote and pentachlorophenol wood
treating processes were discharged directly to unlined ponds near
the western site boundary. (See Figure 1-2, Site Features) One
of Koppers' pentachlorophenol treating processes resulted in
poles with a-layer of pentachlorophenol crystals. From 1963 to
1973, Koppers used a caustic solution to rinse off this excess
pentachlorophenol over unlined soil. In 1963 a treatment process
using pentachlorophenol exploded, resulting in the death of one
Koppers worker. Debris from this fire were buried onsite.
In 1971, pentachlorophenol was detected in onsite ground
water. In 1972, this contamination was found in residential
wells southwest of the site. In 1973, the California Regional
Water Quality Control Board, Central Valley Region (RWQCB) issued
an order to Koppers which led to cleanup activities and process
changes. Two ground water recovery wells were installed. Con-
taminated ground water was discharged to spray fields on the
site. Pursuant to this 1973 order, contaminated debris from the
1963 fire were sent to an offsite landfill. A waste water treat-
ment process was constructed which led to the discontinuation of
direct wastewater discharge to unlined ponds. In 1974, after
contaminant levels in offsite wells declined, the RWQCB Order was
rescinded.
In 1981, the State of California (RWQCB and Department of
Health Services) directed investigations of onsite contamination.
The RWQCB issued two orders in 1982 for the cleanup of con-
taminated soils and ground water.
In September, 1983, the site was proposed for the EPA's Su-
perfund National Priorities List (NPL). In September, 1984 Kop-
pers was finalized on the NPL. Koppers began work on a Remedial
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TREATED LUMBER
STORAGE AREA
Louisiana-Pacific
FIRE SAFETY
WATER POND
FORMER CREOSOTE
POND AREA
FORMER PENTA
DISCHARGE AREA
500
0 1000
Approximate Scale in Feet
FIGURE 1-2 SITE FEATURES
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Investigation/Feasibility Study (RI/FS) work plan in 1984, under
the direction of the California Department of Health Services
(DHS). In mid-1985, the DHS requested that EPA take the lead on
the site. On April 25, 1986, EPA and Koppers agreed to an Ad-
ministrative Order on Consent for Koppers to conduct the RI/FS.
In December, 1983 contaminated ground water was found in
residential wells over one mile south of the Koppers site. In
March, 1984 Koppers began supplying bottled water to residents
with contaminated wells. In March, 1986 Koppers provided an al-
ternative water supply for domestic uses to residents with con-
taminated wells, although residents have been charged for.water
used for irrigation.
On April, 6, 1987 an explosion and fire occurred at one of
Koppers' pentachlorophenol wood treating processes. EPA issued a
unilateral removal order requiring clean-up of fire debris, and
removal and stabilization of surface soils.
Subsequent to the April, 1987 fire, the DHS sampled areas
around the Koppers site. In March, 1988, the DHS announced its
finding of elevated levels of dioxins in chicken eggs in the
area. Further sampling led the DHS to issue an advisory on the
use of agricultural products for an area southeast of the Koppers
facility. In January, 1989 the DHS requested EPA assistance for
its investigation of these dioxin findings. The EPA headquarters
o^-F-ice has met with the DHS and is currently working on recommen-
dations on how to address these area-wide dioxin findings. The
source of the area-wide trace dioxin contamination has yet to be
determined.
In August, 1988, Koppers completed the Remedial Investiga-
tion Report. In November, 1988 the EPA completed an Endangerment
Assessment on the risks from the Koppers site. The draft
Feasibility Study report was completed by Koppers in May, 1989.
On April 28, 1989, the RWQCB adopted Waste Discharge Re-
quirements which place contaminant limits on discharges from
waste water treatment and the onsite recovery well.
In 1988, ownership of the Koppers site changed hands. Be-
tween June and November, 1988, Beazer Materials and Services,
Inc. (Beazer) purchased Koppers Company, Inc. On December 28,
1988, Beazer sold some aspects of the corporation, including the
Koppers/Oroville Superfund site, to Koppers Industries, Inc. Ac-
cording to attorneys for Beazer, Beazer has retained respon-
sibilities for CERCLA matters at the Koppers site.
The EPA will be issuing special notice letters later in 1989
to responsible parties at the Koppers site to initiate Remedial
Design/Remedial Action negotiations on a Consent Decree for fu-
ture site work.
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Correspondence between EPA and Koppers can be found in the
Administrative Record for this site, an index of which is at-
tached to this Record of Decision.
3.0 Community Participation
The EPA has encouraged public participation throughout the
RI/FS, and has gone beyond the CERCLA requirements in this area.
In May, 1986, the EPA solicited comments on the RI/FS work
plan. Regular community meetings were held on a monthly and
bimonthly basis throughout 1986 and 1987. Fact sheets on mile-
stones at the site were sent out to the interested public. RI/FS
documents, including the RI Report, Endangerment Assessment, and
FS Report, were sent to local libraries and a representative of
the major community group.
Input received from the public influenced EPA's oversight of
the RI/FS, and the substance of the RI/FS. Sampling events were
performed by EPA and required of Koppers after suggestions were
made by the public. EPA increased its presence during Koppers'
well-drilling activities in order to respond to public input.
The community has had concerns with the Potentially Respon-
sible Party (PRP) performing the RI/FS and has suggested that EPA
should be doing this investigation instead of Koppers.
Another concern of the community has been with contamination
impacts on ground water, in an area where most people have tradi-
tionally used wells for domestic water supply. Koppers had an
alternative water supply piped into the area in 1986, but con-
cerns remain about the volume of water provided, and the areal
extent of the alternate supply.
A public comment period on the proposed plan was held be-
tween May 22, 1989 and June 20, 1989. Public notice was provided
in a local newspaper, the Oroville Mercury-Register, prior to the
opening of the public comment period. Briefings on the proposed
plan were given to representatives of community groups, elected
officials, and the press on May 16, 1989. In reporting on these
briefings, the press advertised the proposed plan and public com-
ment period. An open house on the proposed plan was held in
Oroville on June 1, 1989 to informally explain the plan and dis-
cuss it with concerned citizens. A formal public meeting, in ac-
cordance with CERCLA section 117(a)(2), was held on June 13,
1989.
EPA has prepared the attached response summary, which
provides EPA's responses to comments submitted in writing during
the public comment period, and to comments that were not ad-
dressed during the June 13 public meeting. A transcript of the
June 13 meeting is also attached.
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Therefore as described above, public participation require-
ments for EPA's selection of the remedy in CERCLA sections
113(k)(2)(B)(i-v) and 117(a) were met.;>
4.0 Scope and Role of Decision
The selected remedial actions address contamination in on-
site soils and ground water impacted by Koppers' contamination.
These actions are considered an operable unit with EPA's first
remedial activities at the Koppers site.
The soils remedy will reduce contamination to health protec-
tive levels consistent with potential future residential exposure
to these soils. Soils beneath the wood treating process area are
not presently being treated as part of these xemedial actions.
However this remedy stipulates that these soils will be-ad-
dressed, consistent with the overall remedial objectives for the
site, when these soils are accessible.
Ground water will be restored to a condition that will
enable its safe use as a public drinking water supply. In 1986,
Koppers provided an alternative domestic water supply to resi-
dents affected by contaminated ground water. The provision of
water was not formalized in a record of decision. This decision
document formalizes the provision of an alternative water supply
to those affected by the contamination until remedial objectives
i^ ground water are met. The volume of water provided will be
sufficient to meet all uses (including irrigation), and to ensure
that contaminated domestic wells are not utilized, and that the
use of wells that would adversely affect the pump and treat
remediation is discontinued.
These selected actions address the documented potential
threats from the site. An additional area is currently being in-
vestigated and could result in future actions regarding this
site. The selected remedies are therefore considered an operable
unit for this site.
Trace dioxin contamination has bean found in offsite soils
and in chicken and eggs. The State of California is investigat-
ing the extent of potential problems, and potential sources of
this contamination. Since dioxin contamination has been docu-
mented onsite at Koppers, it is possible that Koppers is a con-
tributor to the offsite dioxin levels, although there are several
potential sources.
Additionally, an investigation of air emissions from Kop-
pers' ongoing wood treating operations is underway by EPA. At
this point, it is unclear whether these emissions pose a public
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health threat, or whether they would need to be addressed under
CERCLA or other statutory authorities. It is possible that fu-
ture actions will be needed to address these emissions.
5.0 Summary of Site Characteristics
Site characterization activities at the Koppers site have
involved sampling and analysis of soil, ground water, surface
water, sediment, and airborne particulate matter.
Chemical analyses of soils from the Koppers site revealed
the presence of wood treatment formulation chemicals in on-site
soils, resulting from past processing and waste management prac-
tices at the Koppers site. Wood treatment solutions dripped onto
the ground as the treated woods were removed from the process
areas and as treated wood was handled. Waste waters from wood
treating processes were collected in unlined ponds. In addition,
process fires in 1963 and 1987 resulted in releases of pen-
tachlorophenol (PCP) and polychlorinated dibenzodioxins/
dibenzofurans (PCDDs/PCDFs) to site soils. Contamination
releases to onsite soil from the 1987 fire were addressed by a
mitigation program directed by EPA.
Table 5-1 summarizes the results of all soil sampling at the
site. PCP was frequently detected, showing elevated concentra-
tions at the process area, the former Cellon blowdown area, the
pole washing area, and the areas along the railcar tracks north
of the process area. PCP was also detected in two off-site soil
samples where contaminated well water was used for irrigation.
Polynuclear Aromatic Hydrocarbons (PAHs) were detected on site at
elevated 'concentrations in areas in which creosote was stored or
used; for instance, in the vicinity of the former creosote pond
and the process area. Phenanthrene, a PAH compound, was detected
in one off-site sample from the irrigated property.
PCDD/PCDFs were detected in site soils. The highest levels
of PCDDs/PCDFs observed in samples collected by Koppers for the
RI/FS were in soils from the Koppers process area, and in the
former Cellon blowdown area.
Arsenic, chromium, and copper were used by Koppers in the
Copper Chromated Arsenate (CCA) process. Elevated concentrations
of all three metals were found at the process area, with elevated
levels of arsenic and chromium also detected north and west of
the process area where wood treated with these metals was stored.
Ground water in the area occurs in three aquifers. The
physical and chemical characteristics of these aquifers have been
characterized in the Remedial Investigation. Ground water from
the site flows in a generally southerly direction. Contamination
originating from the Koppers site was detected in off-site wells
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891017SAT CON-3
Table 5-1. CONTAMINANTS OF CONCERN, SOIL AND SEDIMENTS. KOPPERS FEATHER RIVER PLANT
Compound
ORGAN I CS
PCP
Detection
Frequency
(wg/kg)
241/344
Soil
Geometric
Mean3
(ug/kg)
480
Maximum
Concentration
(ng/kg)
33,000,000
Detection
Frequency
28/29
Sediments6
Geometric
Mean3
(Kg/kg)
98.03
Maximum
Concentration
(pg/kg)
4,000
2,3,4.6-
tetrachlorophenol
(on-s1te soil only)
PCDDs/PCDFs
Tetra Furans (Total)
Penta Furans
Hexa Furans
Hepta Furans
Octa Furans
Tetra Dloxlns (Total)
Penta Dloxlns
Hexa Dloxlns
Hepta Dloxlns
Octa Dloxlns
PAHs
Acenaphthene
Acenapthylene
Anthracene
Benzo(a)anthracene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(g,h,1)perylene
Benzo(a)pyrene
Chrysene
D1benzo(a,h)anthracene
47/123
12/41
14/41
24/41
28/41
28/41
4/41
10/41
19/41
29/41
35/41
880
240,000
0.86
9
13
23
32
0.27
6.2
16
47
83
15
216
1.360
5.130
15,800
1.9
55
958
9,260
43,700
11/298
8/298
80/298
62/298
103/298
89/298
10/298
60/298
73/298
4/298
16,000
3,600
150
710
150
120
320
300
480
95
77,000
93,000
290,000
220.000
140,000
83,000
12,000
144,000
500,000
400
3/17
7/17
10/17
10/17
10/17
2/17
8/17
7/17
14/17
15/17
0.94
1.66
6.00
14.67
21.86
1.67
1.39
10.75
17.03
47.49
3/8
4/8
8/8
4/8
3/8
4/8
4/8
1/8
185.16
168.31
28.97
114.72
257.49
222.76
276.22
1,400
1.9
24.50
102
305
9,920
1.70
12^20
111.
792
3,900
230
860
940
470
1,300
1,800
1,400
1,400
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Table 5-1. CONTAMINANTS OF CONCERN, SOIL AND SEDIMENTS, KOPPERS FEATHER RIVER PLANT (concluded)
Compound Detection
Frequency
D1ben2o(g,h,1)perylene
Dlbenzofuran
Fluoranthene
Fluorene
Indeno(l,2,3-CD)pyrene
Naphthalene
Phenanthrene
Pyrene
Methylene chloride
(on-s1te soils only)
Xylenes (Total)
(on-slte soils only)
INORGANICS
Arsenic
Boron (on-s1te soils only)
Chromium
Copper
Nickel (on-s1te soils only)
1/12
125/298
41/298
47/298
25/298
134/298
94/298
1/12
1/12
88/112
4/6
114/114
112/112
17/17
Soil
Geometric
Mean3
(ugAg)
64,000
660
1.900
210
5,100
280
1,300
200
91
(mg/kg)
12
10
90
46
56
Maximum
Concentration
(pgAg)
64,000
1,300,000
940.000
60,000
1,500,000
2,400,000
1,200,000
200
91
(mg/kg)
681
28
1,425
1.091
105
Detection
Frequency
1/8
3/8
1/8
2/8
2/8
4/8
28/29
29/29
29/29
Sediments5
Geometric Maximum
Mean3 Concentration
(pg/kg)
38
621.32
69
320.47
404.10
304.52
(mg/kg)
6.92
35.62
21.36
(Mg/kg)
38
2,600
69
1,300
710
2,000
(mg/kg)
36
120
130
J Geometric mean of positive detects only.
b Includes sediments from off-site ponds, down-gradient from Koppers plant.
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in 1972. In order to prevent further off-site migration, two
recovery wells were installed on the Koppers property to inter-
cept contaminated ground water. At the present time, only one of
these wells (RW-2) is still in operation.
Ground water quality has been characterized by sampling
throughout the RI/FS, beginning in June, 1986. Data used to as-
sess site risks were collected through December, 1987. Quarterly
monitoring of ground water has continued to the present and
results from this testing can be found in the Administrative
Record. Thirty-nine on-site wells and 105 off-site wells were
sampled during the RI efforts. Samples were collected from both
monitoring wells and existing private wells. Ground water
samples were collected using standard EPA protocol and were
analyzed for volatile and semivolatile organics and inorganics.
Chemicals detected in on-site and off-site ground water are
listed in Table 5-2, along with the frequency of detection,
geometric mean, and maximum concentrations.
PCP was detected with high frequency in both on- and off-
site monitoring wells. The highest levels were observed in the
former Cellon blowdown discharge area next to the Louisiana-
Pacific (L-P) property line. PCP was detected in off-site ground
water, up to 2 miles south of the site, in a narrow plume which
appears to follow the route of a buried paleovalley.
Isopropyl ether (IPE) has been detected in both on- and
off-site wells associated with the PCP plume. PCP and IPE
originated from the same wood treatment formulation. The highest
IPE contamination was detected in the processing area. IPE was
detected in off-site ground water up to approximately 1 mile
south of the site.
Polycyclic Aromatic Hydrocarbons (PAHs) have been detected
in both on-and off-site ground water. The highest concentrations
of PAHs were detected at the location of the former creosote pond
and in the process area. Detected off-site values occurred in
isolated wells and did not form a distinct plume.
PCDDs/PCDFs are known contaminants of technical PCP and were
also formed by combustion of PCP in the 1987 Cellon process fire.
Low levels have also been detected in on-site and off-site ground
water samples.
Arsenic, boron, and chromium were detected at low levels in
a small percentage of on-site ground water samples. Copper,
chromium, and arsenic were all detected near the CCA treatment
area. These metals have been detected a few times in offsite
wells in very low levels that may be attributable to naturally
occurring metals.
-------
8910175AT COH-1
Table 5-2. CONTAMINANTS OF CONCERN. GROUNDWATER. KOPPERS FEATHER RIVER PLANT
On-Slte Groundwaterb
Compound Detection
Frequency
DRGANICS
?CP
IPE
PCDDs/PCDFs
Tetra 01ox1ns (Total)
Penta D1ox1ns
Hexa D1ox1ns
Hepta 01ox1ns
Octa Dloxlns
Tetra Furans (Total)
Penta Furans
Hexa Furans
Hepta Furans
Octa Furans
PAHs
Acenaphthene
Acenapthylene
Anthracene
Benzo( a) anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(k)f1uoranthene
Chrysene
Dlbenzofuran
Fluoranthene
Fluorene
Indeno(l,2,3-CD)pyrene
2-Methyl naphthalene
111/160
21/42
1/6
1/6
1/6
2/6
5/6
1/6
1/6
1/6
1/6
1/6
3/80
2/80
19/80
4/80
2/80
4/80
4/80
6/80
3/5
35/80
24/80
2/80
3/5
Off -Site Groundwater
Geometric Maximum Detection
Mean* Concentration Frequency
(wg/1)
160
660
0.00025
0.00038
0.00012
0.0009
0.0098
0.0014
0.00082
0.00015
0.000076
0.000020
300
3.9
0.34
4.52
390
1.0
0.79
0.85
180
0.29
3.25
89
160
(wg/i)
44,000
9,400
0.00025
0.00038
0.00012
0.0022
0.022
0.0014
0.00082
0.00015
0.000076
0.000020
1,600
6
3,900
2,000
520
410
290
1,600
970
9,700
12,000
130
2,000
116/372
20/107
1/4
0/4
1/4
2/4
2/4
1/2
1/4
0/4
2/4
0/4
1/113
4/113
1/113
1/113
3/113
2/113
4/113
2/113
_ _
Geometric Maximum
Mean3 Concentration
(ug/i)
3.1
65
0.000012
0.00003
0.000033
0.000067
0.00045
0.000012
0.000027
0.10
0.012
0.0080
0.0080
0.0035
0.0060
0.034
0.088
_
(wg/i)
680
1,300
0.000012
0.0011
0.0013
0.0025
0.00045
0.000012
0.00095
_ __
0.10
0.097
0.008
0.008
0.0045
0.006
0/% f\
.23
0.10
-------
891017SAT CON-2
Table 5-2. CONTAMINANTS OF CONCERN, GROUNDWATER, KOPPERS FEATHER RIVER PLANT (concluded)
On-S1te Groundwaterb
Compound
ORGAN I CS
PAHs (continued)
Naphthalene
Phenanthrene
Pyrene
Benzene
(on-slte GW only)
Ethyl Benzene
(on-slte GW only)
Methylene Chloride
(on-s1te GW only)
Toluene
(on-slte GW only)
Xylenes (Total)
(on-slte GW only)
INORGANICS
Arsenic
Barium
Boron
Chromium (Total)
Copper
Detection
Frequency
13/80
26/80
30/80
3/7
3/7
4/7
2/7
4/7
2/47
2/2
34/39
18/98
6/38
Geometric
Mean3
(pg/D
105
1.36
0.29
4.8
8.7
2.2
21
18
(9/1)
0.021
1.2
0.57
0.02
0.066
Maximum
Concentration
(yg/D
70,000
26,000
8,200
19
110
4.0
150
410
(mg/1)
0.022
1.32/2
1.970/86
0.095
0.252/25
Off -Site Groundwater
Detection
Frequency
3/113
15/113
6/95
0.66
0.41
24/181
0.017
Geometric
Mean3
(wg/1)
0.081
0.011
(mg/1)
0.017
0.69
6.6
0.011
0.030
Maximum
Concentration
(M9/1)
0.18
0.51
(mg/1)
0.027
0.1
3 Geometric mean of positive detects only.
b On-slte groundwater data presents results from testing of the aquifer designated as the B1 Aquifer
by Koppers' consultants. Contamination 1n on-s1te groundwater was found 1n this aquifer.
-------
-17-
Sediment results are presented in Table 5-1. Surface water
results are presented in Table 5-3. PGP was detected in all
sediment sample locations and in 17 of 20 surface water sample
locations. The highest concentrations were in the ditch between
the Koppers and L-P sites, and in a drainage channel immediately
south of the Koppers site. PAHs were detected in all sediment
samples and at low levels in surface waters south of the Koppers
property. The highest PAH levels in sediment samples were
detected in the ditch between the Koppers and L-P sites. Ar-
senic, chromium, and copper were measured in all sediment
samples; arsenic, boron, and copper were detected in on-site and
off-site surface waters.
Results from sampling of airborne particulate are presented
in Table 5-4. Maximum PCP, arsenic, and copper concentrations
were detected at the midsite process location. The highest PAHs
concentration was reported at the northern wood storage area.
6.0 Summary of Site Risks .........
The EPA prepared an Endangerment Assessment to document the
potential risks associated with the no-action remedial alterna-
tive at the Koppers site. This document is included in the Ad-
ministrative Record.
Wood treating operations and waste water handling at the
site have contaminated site soils. Water passing over con-
taminated soils has led to impacts on surface waters and sedi-
ments on the site. Contaminated soil has become airborne due to
vehicular traffic and wind erosion. Soil contamination has, in
turn, migrated into ground water, which has migrated off-site.
The use of contaminated ground water to irrigate offsite soils
has led to contaminated offsite soils.
Characterization of these media in the Remedial Investiga-
tion led to the documentation of sixteen organic and inorganic
contaminants that have been treated as chemicals of concern in
the assessment of site risks.
Table 6-1 presents the contaminants of concern in all media.
Table 6-2 presents the concentrations (geometric means and max-
ima) of these contaminants that were detected and used to assess
site risks.
PCDDs/PCDFs are contaminants of concern at this site. The
concentrations of the various components that make up
this group of compounds are combined into one concentration rep-
resenting 2,3,7,8 Tetrachloro Dibenzo-dioxin, the compound of
most concern from a toxicological standpoint. The calculation of
this Toxicity Equivalent Factor (TEF) is documented in the Endan-
-------
Table 5-3. CONTAMINANTS OF CONCERN, SURFACE WATER, KOPPERS FEATHER RIVER
SITE
Compound
ORGANICS
PCP
IPE
PCDDs/PCDfs
Tetra Furans (Total)
Hexa Furans
Hepta Furans
Octa Furans
Hexa Dloxins (Total)
Hepta Dioxlns
Octa Dioxlns
PAHs
Anthracene
Fluoranthene
Fluorene
Phenanthrene
INORGANICS
Arsenic
Boron
Chloride
Chromium
Copper
Detection
Frequency
15/18
6/15
1/6
3/12
3/12
1/12
2/6
3/12
6/12
2/5
1/5
1/5
1/5
14/31
15/24
15/32
3/31
6/31
Geometric
Mean4
ug/i)
8.22
21.41
(ng/i)
0.60
5.19
13.52
11.10
3.32
35.30
17.25
(ug/1)
0.03
0.10
0.22
0.28
(rag/1)
0.01
0.77
11.99
0.03
0.01
Maximum
Concentration
(ug/D
140
50
(ng/D
0.60
8.52
19.85
11.10
3.35
44.55
96.65
(ug/i)
0.041
0.10
0.22
0.28
(mg/1)
0.030
1.10
71
0.030
0.030
a Geometric mean of positive detects only.
-------
8910175AU CON-1
Table 5-4. CONTAMINANTS OF CONCERN, AIR. KOPPERS FEATHER RIVER SITE
Compound
Pentachlorophenol
PAHs
Acenaphthene
Acenaphthylene
Anthracene
6enzo(a anthracene
Benzo(a)pyrene
Beruofb f luoranthene
Benzoi k f luoranthene
Beiuo g,h.1)perylene
Chrysene
Fluoranthene
Fluorene
Indeno(1.2,3-CD)pyrene
Napthalene
Phenanthrene
Pyrene
Inorganics
Arsenic
Chroalua (Total)
Copper
Total Suspended
Participates
Detection
Frequency
10/18
0/18
0/18
1/18
0/18
0/18
0/18
0/18
0/18
1/18
0/18
1/18
0/18
2/18
6/18
0/18
0/6
16/18
18/18
18/18
Cross wind
Mean"
(M9/«3)
1.02E-04
NO
NO
4.15E-04
NO
NO
NO
NO
NO
1.81E-04
NO
1.10E-04
NO
7.62E-04
1.07E-04
HO
NO
3.87E-02
1.11E-02
1.13E+00
MaxImM
(pg/-3)
2.04E-04
NO
NO
4.15E-04
NO
NO
NO
NO
NO
1.81E-04
NO
1.10E-04
NO
7.89E-04
9.74E-04
NO
NO
3.59E-01
1.95E-02
3.78E+01
Detection
Frequency
83/84
2/84
5/84
63/84
21/84
17/84
68/84
45/84
9/84
28/84
68/84
4/84
29/84
2/84
43/84
40/84
5/12
83/84
84/84
84/84
Downwind
Mean"
(M9/«3)
1.90E-02
1.98E-02
8.94E-03
9.00E-04
3.51E-04
4.58E-04
3.24E-04
1.72E-04
2.06E-03
7.98E-04
1.27E-03
1.50E-03
3.86E-04
3.80E-03
1.21E-03
8.59E-04
2.98E-03
1.95E-02
9.62E-02
1.93E+02
Location
Maximum Detection
(eg/a ) Frequency
3.44E-01 42/42
2.65E-02 0/42
1.29E-02 0/42
1.03E-01 25/42
2.56E-03 14/42
2.53E-03 11/42
2.47E-03 40/42
1.16E-03 37/42
1.4 IE -02 10/42
8.09E-03 21/42
1.53E-02 42/42
3.19E-03 3/42
2.66E-03 14/42
3.87E-03 0/42
1.83E-02 30/42
1.03E-02 26/42
5.14E-03 6/6
7.23E-01 41/42
2.18E-01 42/42
7.64E+02 42/42
Mldslte
Mean'
(pg/«3)
3.39E-02
NO
NO
4.35E-04
8.96E-04
8.96E-04
1.15E-03
5.10E-04
1.21E-03
1.97E-03
3.10E-03
1.28E-03
6.79E-04
NO
1.89E-03
2.45E-03
6.88E-03
4.78E-02
1.25E-01
2.18E+02
Maximum
(pg/m3)
4.20E-01
NO
NO
2.92E-03
3.65E-03
2.73E-03
1.02E-02
5.01E-03
3.36E-03
1.53E-02
3.27E-02
1.51E-03
2.06E-03
NO
1.69E-02
2.61E-02
2.57E-02
6.49E-01
6.54E-01
7.15E402
t
Detection
Frequency
41/41
0/41
0/41
14/41
6/41
9/41
36/41
17/41
8/41
1/41
25/41
2/41
15/41
2/41
13/41
8/41
0/6
37/41
41/41
41/41
pwlnd
Mean"
(Mg/m3)
9.23E-04
NO
NO
1.87E-04
2.22E-04
2.64E-04
1.51E-04
1.04E-04
3.68E-04
8.48E-04
2.31E-04
1.52E-03
3.62E-04
3.08E-03
3.41E-04
2.06E-04
NO
1.36E-02
5.12E-02
6.35E+01
Max tnun
(pg/n3)
2.53E-02
NO
NO
1.05E-03
8.01E-04
1.19E-03
1.15E-03
5.25E-04
1.48E-03
8.48E-04
1.06E-03
4.43E-03
1.30E-03
5.81E-03
9.56E-04
5.63E-04
NO
6.19E-01
1.08E-01
1.68E+02
GeoMtrlc *ean of positive detects only.
NO Not Detected
-------
TABLE 6-1
Contaminant* of Concern
In All Media
(Copper* feather River Site
AH*
immmmmmmmmmmmmmm*mmmmmf^mmmmmmmmmnm**+mmmmmmmmmmm
On- site Off-site
xwid toiu toll*
itachlorophenot X X
1.4,6-Tetrachloropnenot K
propyl ether
Os/PCDFs
! MX
aene
lyt beniene
hylene chloride X
uene
nee X
On- site Off-tit* Surface Sedlwenta Air
Crounduater Crounduater Water
X « X X X
X X
X XX
X X X XX
X X XXX
X ...
X * * * *
II ' *
X ...
X ...
X corrta»lnent of concern for thl* Mdlua.
- not contaminant of concern for thU edlux. for reasons discussed In the text.
-------
TABJ.E 6-1
(continued)
On- site
Compound Soil*
Arsenic X
arlue
oron X
Chromium
Copper X
Ickal X
Off-site On-slte Off-site Surface Sediments Air
Soils Grounduater Croundwater Water
X X XXX
X X
X X -X
X X XXX
X X XXX
X
contaminant of concern for this
not a contaminant of concern for this medlu». for reasons discussed In the text.
-------
I I f *\
Concentrations oYTontMlnants of Concern
Used In Exposure Assessment
All Soil*
Surface Soils
Ceoawtrlc
Mean
Geometric
ntfM*
MMla
unpevcd Surface
Soils
Geometric
Mean Nixlau
Off-site Surface Soils
(Prince property)
Ceoa*trlc
Mean NaxliMi
CVTACmOMMKttlt
tf 18 ACMOMPsXiM.
(TOO Equivalents)
Ms: CMCinoniC
Ms: MM-CAKCIMCfRIC
VDLMIIEI
MMVMM
EflKR
CHIMIK
I ROMANIC*
*
AMCNIC
MHIUN
TOtUCNC
CMKMIUN (TOTAL)
com*
NICKCL
1)
k
ZRIC
(ug/ko)
480 S3,000,POO
880 240,000
0.20 84.8
2.100 1.150.000
93,000 '. MO. 000
*
» *
200 200
91 91
12 681
110 178
10 28
90 1,425
46 1.091
56 105
(ug/kg; (up/kg)
420 33.000,000
2eO 240.000
24 84.8
1,900 810.000
110,000 2.280.000
* *
% . * *
(g/kg)
1* 681
*
8.0 8.0
92 1,425
51 1.100
55 90
(ug/kf) (ug/kg)
290 33,000,000
120 240.000
11 () 84.8
1,600 810.000
34,000 2.280,000
-» «
*
» .
»*
*
(«g/ka)
14 681
8 8
92 1.425
48 1,091
34 34
(ug/kg) (m/ka)
If If
« *
* * *
8.9 8.9
*
* * *
..
C«g/k«>
» »
*
« »
..
(a) Two saaples of unpaved surface soils with detected PCDOt/PCOFs.
- not of concern In this wedlu*. not detected, or mnltorlng data not available.
HD - Hot detected
-------
...------ -
TABkl 6-2 (continued)
Concentration! of Contanlnanta of Concern
U$«d In Exposure AttesMwnt
*»'* Off-alte «lr Sedlacnta Surface Water
eroundwater Crouncfcater (Ntdslte) Off-alte Ponda Off-alte Ponfc
CeoMtrlc
Chealcal Mean RaMlaua
PERTACNLOROMENOl
POtte/PCDFa
(top Eojulwalenta)
Mat CMCIMOENIC
Mat KM-CMCINOCniC
VOLATILE*
ENZENE
ETNuoEmaf
ifOPRom ETN«
NETNTLENE CNLOtlOC
TOLUENE
RYLENES
INOXGMICt
MSCNIC
OMIUN
gown
CNtOMlUN (TOTAL)
COPPCt
NICKEL
Cut/ll (ug/l)
MO 44,000
2.5E-06 2.0E-04
490 5.000
750 135.000
4.8 19
8.7 110
660 9.400
2.3 4
21 150
18 410
(g/l) (*g/t>
0.021 0.022
1.2 1.3
0.37 1.9
0.020 0.095
0.066 0.25
Ceowtrlc
Mean *toxliM«
a
.(ug/l) (ug/l)
3.1 680
4.1E-06 4,11-06
0.026 0.026
0.33 1.2?
65 1300
* »
* »
* *
(9/0
0.017 0.027
0.660 0.690
0.410 6.6
0.011 0.100
0.017 O.OJO
Ceowtrlc
Mean Max) MM
(ug/Ml)
1.9E-02 3.4E-01
> * *
5.3E-05 3.31-04
8.9E-05 7.2E-04
*
* *
* * *
6.8E-03 2.6E-02
4.8E-02 6.5E-01
1.2E-01 6.5E-01
Geometric
Mean Maxlaua
(ug/kg) (ug/kg)
43 1.400
NO NO
2.4E-02 2.71*00
6.600 MOO
1.300 1.300
*
* *
* *
(^/k.) (^/kg,
8.6 36
*
* »
32 120
21 130
CeoMetrlc
Mean Nanliua
(ug/l) (ug/l)
J.J 92
2.80E-04 2.80E-M
» MO
0.6 0.6
o *
* .
10 10
(9/1 ) (M9/O
t
0.015 0.030
0.71 0.60
24 30
0.030 0.030
a "
- not of concern In
NO - Not detected
this edlu*, not detected, or Monitoring data not available.
-------
-24-
germent Assessment. When the toxicity and remediation of
PCDDs/PCDFs are discussed in this Record of Decision, they are
given in terms of TEF.
A variety of potential current and future exposure scenarios
were evaluated. Table 6-3 presents the six current use scenarios
and four future-use scenarios for exposure that were evaluated.
Since alternative water supplies are currently used for both
on- and off-site drinking water, the current use scenarios only
include indirect exposure to ground water used for irrigation.
Future-use scenarios examined include the potential use of
ground water for drinking, and the possible residential use of
the site.
Exposure was assessed for both an average case and a maximum
plausible case for each exposure scenario. For the average case,
geometric mean concentrations are used, together with what are
considered to be the most likely exposure conditions. For the
maximum plausible case, the highest measured concentrations are
generally used, together with high, although plausible, estimates
of the range of potential exposure parameters relating to fre-
quency and duration of exposure and quantity of contaminated
media contacted.
Since Koppers did not complete ground water modeling for the
purposes of the endangerment assessment, it was assumed that
ground water contamination would remain constant over the ex-
posure scenarios. EPA consultants who authored the endangerment
assessment used standard assumptions for the degree of exposure
(i.e. amount of water consumed by an adult, area of skin exposed
in direct contact with soils).
The applicable toxicological criteria at the time the endan-
germent assessment was prepared were used in assessing risks.
These criteria are presented in Table 6-4.
Cancer potency factors (CPFs) have been developed by EPA's
Carcinogenic Assessment Group for estimating excess lifetime can-
cer risks associated with exposure to potentially carcinogenic
chemicals. CPFs, which are expressed in units of (mg/kg-day)-1
are multiplied by the estimated intake of a potential carcinogen,
in mg/kg-day, to provide an upper-bound estimate of the excess
lifetime cancer risk associated with exposure at that intake
level. The term "upper-bound" reflects the conservative estimate
of the risks calculated from the CPF. Use of this approach makes
underestimation of the actual cancer risk highly unlikely. Can-
cer potency factors are derived from the results of human
epidemiological studies or chronic animal bioassays to which
animal-to-human extrapolation and uncertainty factors have been
applied.
-------
TABLE 6-3
Scenarios Used for Risk Characterization
Koppers Feather River Site
Medium
Population Exposed
Exposure Route
Current-Pse
Unpaved on-site surface
oils
Off-sice soils
Off-site soils
Off-site groundvater
Off-site sediments
Air
Future-Use
On-site surface soils
On-site subsurface soils
On-site groundvater
Off-site groundvater
trespassers
residents
residents
residents
resident children
residents downwind
potential residents
construction workers
potential residents
potential z*sl4ea£s
ingestion/dermal
ingestion/dermal
ingestion of
vegetables
Ingestion of neat
and/or milk
Inge s t ion/de rma1
inhalation
ingestion/dermal
Ingestion/dermal
Ingestion
Ingestion
-------
TABLE 64
HEALTH-BASED CRITERIA FOR ORGANIC CONTAMINANTS OF CONCERN*
KOPPERS FEATHER RIVER SITE
Cheaical
Risk
Reference Dose
Cancer
Potency Factor
Oral
Inhalation
Oral
Inhalation
Benzene
Ethylbenzene
Isopropyl Ether
Jfethylene Chloride
Pentachlorophenol
2,3,4.6-Tetra-
chlorophenol
Polychlorinated
dibanzodioxin* (PCODs)d
PAHs"
(nap lene)
Carcinogenic PAHs*
'benzo [ a J py rane )
oluene
ylenes (mixed)
1 X 10
-1
2.6 X 10"1
3 x lO'2
3 x 10'2
1 X 10"9
4.1 X 10"1
3 X 10*1
2.0
2.9 X 10'2 [A]c 2.9 X 10'2 [Aj
2.6 X 10
7.5 x 10'3 [B2J
1.56 X 105 [B2] 1.56 X 105 [B2J
11.5 (B2J
6.1 [B2]
4.4 X 10
1.5
-1
Health-based criteria are derived fro* nuabcr of sources. Sources for the criteria are
given in the discussions of the toxic properties of the individual cheaicals presented in
Section 3.2 of this report.
-- - no criteria hav* b««n developed.
EPA Weight of Evidence Classification for the compound by the specific route of
xposure. Weight of the evidence classification: Group A Human Carcinogen; Croup B2 -
Probable Human Carcinogen based on sufficient evidence from animal studies.
Criteria based on 2,3,7,8-TCDD equivalence.
^rcinogenic PAHs as represented by benzo[ajpyr«n«, non-carcinogenic PAHs by naphthalene.
-------
TA3LE 6-4
(CONTINUED)
HEALTH-BASED CRITERIA FOR INORGANIC CONTAMINANTS OF CONCERN*
KOPPERS FEATHER RIVER SITE
Chemical
Risk
Reference Dose
Cancer
Potency Factor
Oral
Inhalation
Oral
Inhalation
Arsenic
Barium
Boron
Chroaiua III
Chroaiua VI
Copper
Nickel
...
5.0 X 10"2 1.4 X 10"4
8.6 X 10"2
l.» 5.1 X 10"3
5 X 10°
3.7 x ID*2 1 X 10~2
.2
2 X 10 i
1.5 (A]e 50 [A]
... ...
...
...
41 (A]
0.84 [A]e
* Health-based criteria are derived froa » zuaaber of sources. Sources for the criteria are
given in the discussions of the toxic propertie* of the individual chemicals presented in
Section 3.2 of this report.
-- -no criteria have been developed.
c EPA Weight of Evidence Classification for the compound by the specific route of
xposure. Weight of the evidence classification: Group A - Human Carcinogen; Bl -
Probable Human Carcinogen based on limited evidence from human studies and sufficient
evidence from animal studies; Group B2 - Probable Human Carcinogen based on aufficient
evidence from animal studies.
* Value reported is for nickel refinery dust.
-------
-28-
Reference doses (RfDs) have been developed by EPA for in-
dicating the potential for adverse health effects from exposure
to chemicals exhibiting noncarcinogenic effects. RfDs, which are
expressed in units of mg/kg-day, are estimates of lifetime daily
exposure levels for humans, including sensitive individuals. Es-
timated intakes of chemicals from environmental media (e.g., the
amount of a chemical ingested from contaminated drinking water)
can be compared to the RfD. RfDs are derived from human
epidemiological studies or animal studies to which uncertainty
factors have been applied (e.g., to account for the use of animal
data to predict effects on humans). These uncertainty factors
help ensure that the RfDs will not underestimate the potential
for adverse noncarcinogenic effects to occur.
It should be noted that the Koppers endangerment assessment
was prepared using an RfD for pentachlorophenol since this was
the applicable toxicological criteria available for this chemical
at the time the risks were assessed. This chemical will likely
be reclassified by EPA as a carcinogen. If this occurs, the CPF
that is eventually adopted by EPA will be used in assessing the
progress of remediation in the five-year review.
Cancer risks calculated in the endangerment assessment are
probabilities that are generally expressed in scientific notation
(e.g., IxlO""6) . An excess lifetime cancer risk of IxlO"6 indi-
cates that, as a plausible upper bound, an individual has a one
in one million chance of developing cancer as a result of site-
related exposure to a carcinogen over a 70-year lifetime under
the specific exposure conditions at a site.
Potential concern for noncarcinogenic effects of a single
contaminant in a single medium is expressed as the hazard
quotient (HQ) (or the ratio of the estimated intake derived from
the contaminant concentration in a given medium to the
contaminant's reference dose.) By adding the HQs for all con-
taminants within a medium or across all media to which a given
population may reasonably be exposed, the Hazard Index (HI) can
be generated. The HI provides a useful reference point for guag-
ing the potential significance of multiple contaminant exposures
within a single medium or across media.
A summary of potential health risks for various exposure
pathways, in term of excess cancer risks, and hazard indices, are
presented in Table 6-5.
As table 6-5 illustrates, the highest current potential
health risks were concluded to be exposure by trespassers to sur-
face soil (9xlO~7 average exposure, 2xlO~4 maxium plausible ex-
posure) and inhalation of airborne dusts (3xlO~6 average ex-
posure, lxlO~4 maximum plausible exposure). The non-carcinogenic
risks from current use exposure did not exceed a hazard index of
1 for any exposure pathway.
-------
TABLE 6-5
J
J
Summary of Potential Health Risks
Koppers Feather River Site
Chemical
Noncarcinogenic
Hazard Index
(CDIrRfD)
Average Maximum
Case Plausible Case
Total Upper-bound
Lifetime Excess
Cancer Risks
Average
Case
Maximum
Plausible Case
CURRENT USE
1. Exposure of trespassers
to surface soil
contaminants
FUTURE VSE
Exposure to
contaminated soil
residents
workers
Use of off -site
groundvater as a
potable water supply
off-sice
on-site
<1
2. Exposure of residents <1
to off-site soil
contaminants
3. Ingest ion of produce <1
grown in contaminated
off-site soils
4. Ingestion of beef and
Billr'froa covs drinking
contaminated groundvater
- beef
- ailk
5. Exposures of area
children to
contaminated sediments
6. Inhalation of
concamioanted air-
borne dusts.
<1
<1
<1
>1
<1
<1
<1
<1
9 x 10
-7
6 x 10
1 x 10
-7
-6
2 x 10"
3 x 10
-6
5 x 10
8 x 10
-8
1 x 10
7 x 10
-A
-3
2 x 10
4
4 x 10'
2 x 10"
2 x 10
-5
1 x 10
7 x 10
8 x 10
2
-3
1 x 10
8 x 10'
-3
-------
-30-
Higher health risks were associated with potential future
residential use of the site (5xlO~4 average exposure, 7xlO~2 max-
imum plausible exposure), and use of contaminated onsite ground
water (7xlO~3 average exposure, SxlO"1 maximum plausible
exposure). Risks from exposure to non-carcinogens exceeded a
hazard index of 1 for several potential future use exposures.
The Endangerment Assessment documents uncertainties in these
risk conclusions, which may both over- or underestimate risks.
It is recognized that the assumption that ground water contamina-
tion will remain the same and not attenuate or biodegrade may
overestimate risks, while the assumption that intake over time is
constant and representative of the exposed population may under-
estimate risks.
The Remedial Investigation Report and Endangerment Assess-
ment both looked at potential environmental receptors. The
Feather River Wildlife Refuge is located on the western side of
the Feather River near the site. Sampling of the Feather River
water and sediments did not find site-related contaminants, and
thus it can be concluded that the site contamination is not af-
fecting this refuge. Waterfowl and other wildlife frequenting
onsite ponds and ditches may be at risk from ingestion and dermal
contact with contaminants in surface water and sediments. The RI
Report documents that a search of the California Natural Diver-
sity Data Base was performed for threatened or endangered species
occurring in regions in which the Koppers site and adjacent areas
are located. Although several threatened or endangered flora and
fauna were identified as potentially occurring in this area, none
have been observed on or directly adjacent to the Koppers site,
primarily due to the disturbed, industrial nature of the area.
Therefore, as described above, actual or threatened releases
of hazardous substances from this site, if not addressed by im-
plementing the response actions selected in this ROD, may present
an imminent and substantial endangerment to public health, wel-
fare, or the environment.
7.0 Description of Alternatives
Because of the variety of contaminants, and the distinct
land use patterns present at the site, alternatives were
developed for remediation of four onsite soil units and on and
offsite ground water. The size and make-up of these units is
summarized in the following:
-------
-31-
Unit
SI
S2
S3
S4
Contaminant
PCP
PCP, PAHs
PCP, PAHs,
Metals
Metals
Area
(Sq. Ft.)
869,300
800,000
308,000
84,600
Maximum
Depth
(Feet)
10
25
1-6
5
Volume
110,000 yd3
200,000 yd3
19,400 yd3
4000 yd3
GW PCP, IPE 16.1 X (10°)
(off-site)
GW PCP, IPE, 3.9 x (106)
(on-site) PAHS, Metals
3.01 x (108) ft3
8.4 X (107) ft3
The following discussion presents a brief description of the
soil and ground water remedial alternatives that have survived
the preliminary screening and been carried through a detailed
analysis in the Koppers FS. Preliminary screening can be found
in the Koppers Feasibility Study (FS) report. It should be noted
that the numerical designations of the alternatives (e.g. Sl-3)
have been changed from the FS report in attempt to clarify the
discussion in this ROD.
7.1 SOIL ALTERNATIVES
A brief description of each of the four soil units precedes
the discussion of the alternatives considered in the detailed
analysis.for that specific soil unit. The estimated areal extent
of these soil units is shown on Figure 7-1.
7.1.1 Soil Unit 81 includes the former pole washer area and
areas along the drip track leading to the process area, the areas
east and south of the process area, the fire debris site at the
eastern side of the Western Spray Field, and the surface soils
throughout the treated wood transport areas. The principal
chemicals of concern in SI are PCP and PCDDs/PCDFs. The es-
timated area of SI is 869,300 square feet and the estimated total
volume of soil is 110,000 cubic yards.
-------
L-P
APPROXIMATE EXTENT OF CONTAMINATED SOILS
-------
-33-
7.1.1.1 Alternative Sl-l - Excavation and Soil Washing
Excavation would be accomplished by conventional methods, using a
dragline excavation, a backhoe, or both. Soil washing operations
would be used to remove contaminants from solids for treatment or
reuse. Because of the variability in physical and chemical
properties of the contaminated soil, the soil washing unit (or
series of units) must be equipped to operate under variable con-
ditions. After contact with the soil, the washing solution is
treated and discharged or recirculated through the washing
process. The treated soil is then dewatered and placed back into
the excavation. The water from dewatering operations will be
treated onsite.
7.1.1.2 Alternative Sl-2 - In situ biodegradation
Biodegradation of soils is based on the fact that microbes cur-
rently exist in the soil that have adapted to, and are using, PCP
and other organic chemicals as carbon sources. This biodegrada-
tion process is capable of mineralizing the contaminants. In
this alternative, the natural system is enhanced to overcome rate
limits by adding nutrients and oxygen to the contaminated soil.
In alternative Sl-2, water with oxygen and nutrients will be ap-
plied to surface soil. The water is subsequently withdrawn by
shallow extraction wells in the treatment zone, treated, reinocu-
lated with oxygen and nutrients, and returned to the soil. Over
time, the combined action of water flushing contaminants from the
»oil and microbes degrading contaminants will cleanse the soil.
7.1.1.3 Alternative Sl-3 - Excavation and Onsite Landfilling
This alternative involves transferring the soil in SI from its
present on-site location into a secure on-site landfill. The
landfill would be designed to meet RCRA and California standards
for Class 1 landfills.
7.1.1.4 Alternative Sl-4 - Capping
This alternative specifies capping the SI area with a low per-
meability cap designed to contain contaminants and support site
activities. The cap will be constructed by removing 1-2 feet of
surface soil, backfilling with clean soil as necessary, providing
a layer of clean, crushed rock to support the cap, and installing
a low permeability cap, likely to be asphalt.
7.1.2 Soil Unit 82 includes the former creosote pond and Cel-
lon blowdown areas, an area of creosote-contaminated soil along
the L-P ditch, and sediments in off-site drainage ditches and
ponds southwest of the Koppers site. The soil contained within
this unit is estimated to cover 800,000 square feet with a total
volume of 200,000 cubic yards.
-------
7.1.2.1 Alternative S2-1 - Excavation and Soil Washing
The excavation will be accomplished by conventional methods,
using a dragline excavation, backhoe, or both. Soil washing will
be used to remove contaminants from the soil for treatment or
reuse. In general, available soil washing techniques incorporate
the use of physical 'separation procedures for particle size
screening and then washing of contaminants from the soil into a
liquid medium. After contact with the soil, the washing solution
is treated and discharged or recirculated through the washing
process. The treated soil is dewatered and placed back into the
excavation.
7.1.2.2 Alternative S2-2 - Excavation and on-site landfill
This alternative involves transferring the soil in S2 from its
present on-site location to a secure on-site landfill. The
landfill will be designed to »eet RCRA and California standards
for Class 1 landfills.
7.1.2.3 Alternative S2-3 - Capping
This alternative specifies capping the S2 area with a low per-
meability cap designed to contain contaminants and support site
activities. The cap will be constructed by removing 1-2 feet of
surface soil, backfilling with clean soil as necessary, providing
a layer of rock to support the cap, and installing a low per-
meability cap, likely to be asphalt.
7.1.3 Soil Unit S3 includes the wood treating process area.
The area is characterized by elevated levels of PCP, creosote-
related PAHs, and metals. The process area is considered to be a
separate unit in order to allow the application of a remedial ac-
tion that permits continued manufacturing operations. The soil
in S3 is estimated to cover 308,000 square feet with a total
volume of 19,400 cubic yards. For the soil remedy at Unit S3,
only alternatives that could be implemented with continued wood
treating operations were considered in the detailed analysis.
As part of the selected remedy for this unit, when soil beneath
the process area is accessible, the contamination will be
remediated in a manner consistent with soil in other units.
7.1.3.1 Alternative S3-1 - No Action
This alternative for the process area and adjacent soil
would involve institutional actions, and monitoring. Quarterly
monitoring from five specified wells (three existing and two new
wells) is included in this alternative.
7.1.3.2 Alternative S3-2 - Capping and Ground water Extraction
-------
-35-
This alternative includes capping (with limited excavation)
of the process area and ground water pumping. The process area
and adjacent soils will be capped with a concrete cap designed to
contain contaminants and support manufacturing activities. The
cap will be constructed by removing 1 to 3 feet of surface soil,
backfilling with soil as necessary, providing a layer of base
rock to support the concrete, pouring concrete an estimated 6
inches thick with reinforcing bars, and sealing the concrete
seams as required to reduce infiltration. Extraction wells will
be installed near the process area to contain contaminated water
beneath the facilities. This pumping system will supplement the
extraction system alternative proposed for the ground water
remediation.
7.1.4 Soil Unit 84 consists of soil in the areas east and
south of the process area where wood treated with metals has been
stored. These soils contain arsenic, chromium, and copper. The
boundaries of unit S4 are defined by those soils with arsenic and
chromium concentrations in excess of local background concentra-
tions. The exact extent of this area will be determined during
remedial design. In the FS report, using a 10~4 risk level, this
unit has been estimated to cover 84,600 square feet with a total
volume of 4000 cubic yards.
7.1.4.1 Alternative S4-1 - No Action i
This no remedial action alternative for S4 would involve institu-
tional actions, and monitoring. Quarterly monitoring from four
specified wells is included in this alternative.
7.1.4.2 Alternative S4-2 - Excavation and Fixation
I
This alternative proposes to chemically stabilize the S4 soils
with an agent designed to immobilize the contaminants. Soils in
unit S4 would first be excavated. The soils would be mixed with
water; a fixation reagent added; the soil, water, and reagent
mixed to facilitate the reaction; and the mixture would be
redisposed of on the site and allowed to cure. The fixation
reagent may contain, for example, gypsum, blast furnace slag,
Portland cement, and other minor constituents. Fixation of soil
reduces the potential for soil to act as a source of further
ground water contamination.
7.1.4.3 Alternative S4-3 - Excavation and Offsite Disposal
This alternative proposes excavation and disposal to an off-site
landfill. Unlike the other soil units, S4 may be small enough
that off-site landfill disposal is an economic and environmen-
tally sound alternative. After excavation, the soil would be
loaded onto rail cars or trucks at the site for transportation to
a RCRA-permitted landfill meeting EPA's Offsite Policy require-
ments. Currently the closest such facilities are located in
Idaho and Utah.
-------
7.2 GROUND WATER ALTERNATIVES
The off-site and on-site ground water areas of contamination
are combined into one unit for the Koppers site. The PCP cleanup
level of 2.2 ug/1 established an off-site area of 16.1 x 10°
square feet, with a mean thickness of 62.8 feet, for a volume of
3 x 108 cubic feet. The on-site area is approximately 3.9 x 10°
square feet, with a mean thickness of 71.3 feet, for a volume of
8.4 x 107 cubic feet.
Creosote is present in small volumes of on-site ground water
as a free oil phase in the immediate vicinity of the former
creosote ponds. Here it appears that free creosote exists as a
separate liquid phase in thin pools of on the top of clay lenses
that occur within the gravelly aquifer. PAHs, PCP,
dioxins/furans, IPE, arsenic, and chromium have been established
as contaminants of concern in on-site groundwater.
The estimated areal extent of the ground water contamination
is shown on Figure 7-2.
Extraction and treatment of ground water was the only ap-
proach that was evaluated in the detailed analysis of alterna-
tives. Containment, and other options, were screened out because
they would not adequately protect public health. A variety of
treatment methods to remove contamination from ground water were
net evaluated in the detailed analysis, since site specific
treatability studies have shown that carbon adsorption effec-
tively removes contamination. When water is treated by carbon
adsorption, contaminated water is passed through a bed of carbon
and the contaminants are physically retained by the carbon par-
ticles. Koppers will be demonstrating a modified carbon adsorp-
tion system which utilizes a biological process for regeneration
of carbon (known as "Bi-far"). If the demonstration of this
process proves it is successful, it will be used in the ground
water remediation. If this process is not acceptable, another
polishing technique utilizing carbon adsorption will be applied.
Institutional actions such as site access and ground water
use restrictions will be implemented for all alternatives.
These activities include the continued supply of alternative
water. The water supply will be expanded as necessary to ensure
that contaminated residential wells are not used for any purpose
(including irrigation). In addition, during the remedial design,
it will be necessary to determine whether the use of other wells
will interfere with the extraction of contaminated ground water.
If such wells are identified, they will need to be replaced with
an alternative water supply.
Ground water extraction will be accomplished by the con-
struction of groundwater recovery wells to be located during
remedial design. At the plant site, wells specifically designed
-------
Based on October, 1988 sampling results
FIGURE 7-2
APPROXIMATE EXTENT OF GROUND WATER CONTAMINATION
-------
-38-
to recover free creosote will be placed near the former creosote
pond area. Pretreatment of on-site ground water may consist of
filtration to remove suspended solids and fine silt, if present.
Pretreatment is optional depending on the quality of pumped
water. Pretreatment of on-site fluids would also include
oil/water separation. Recovered oils may be reused in the
manufacturing process. Ground water treatment by carbon adsorp-
tion will be required to meet discharge limits.
Two alternatives were evaluated for the discharge of the
treated ground water.
7.2.1 Alternative G-l - Disposal to Surface Water
Under this alternative, treated water from both onsite and off-
site extraction wells would be discharged to surface wafer that
would eventually run into the Feather River.
7.2.2 Alternative G-2 - Disposal to Ground Water
Under this alternative, treated water from both onsite and off-
site extraction wells would be discharged via recharge wells into
the aquifer.
8.0 Applicable and Relevant and Appropriate Requirements (ARARS)
and To Be Considered Criteria
Remedial actions selected under CERCLA, as amended by the
Superfund Amendments and Reauthorization Act of 1986 (SARA), must
attain levels of cleanup of hazardous substances released into
the environment and control of further release which assure
protection of human health and the environment. SARA specifies
that any selected remedial action must achieve a level or stan-
dard of cleanup that meets legally applicable or relevant and ap-
propriate requirements, standards, criteria, or limitations
(ARARs).
ARARs are generally separated into three categories: (1)
ambient or chemical specific requirements that set health or
risk-based concentration limits or ranges for particular chemi-
cals; (2) performance, design, or action-specific requirements
that govern particular activities; and (3) location-specific re-
quirements .
The regulatory framework for setting remedial objectives for
the cleanup of groundwater and soil at the Hoppers site and for
the selection of ARARs is based on the beneficial (current or
potential) use of local ground water as a drinking water supply.
In the Agency's explanation of the implementation of SARA,
Federal Register on page 51433 (December 21, 1988), "The goal of
EPA's Superfund approach is to return usable ground waters to
their beneficial uses within a timeframe that is reasonable."
-------
-39-
Use of ground water for drinking is considered to be the highest
beneficial use and warrants the greatest level of protection and
cleanup.
8.1 CHEMICAL-SPECIFIC ARARS
Chemical-specific ARARs for the Koppers site are Federal and
state of California drinking water standards. Each is relevant
and appropriate to setting cleanup standards at the site. Ap-
plicable Federal and State drinking water standards are presented
in the first column of Table 8-1.
In addition, maximum allowable concentrations of con-
taminants in soils are set by State of California standards.
8.1.1 Federal Drinking Water Standards
Potential drinking water standards at the Koppers site in-
clude Maximum Contaminant Levels (MCLs), Maximum Contaminant
Level Goals (MCLGs), and Secondary Maximum Contaminant Levels
(SMCLs). As stated in CERCLA Section 121(d)(l), MCLGs are men-
tioned as potential cleanup standards when these levels "are
relevant and appropriate under the circumstances". Only one
MCLG, 220 ug/1 for PCP, is potentially appropriate at the Koppers
site. This MCLG is considered relevant and appropriate to the
I\^^peiT5 site.
The relevant and appropriate standards to establish
groundwater cleanup levels at the site are the Federal Maximum
Contaminant Level (MCLs), as established under the Safe Drinking
Water Act. EPA bases this decision on the fact that MCLs are in
most cases fully protective of human health.
8.1.2 State Drinking Water Standards
California Drinking Water Standards establish enforceable
limits for substances that may affect health or aesthetic
qualities of water and apply to water delivered to customers.
The state's Primary Standards are based on federal National In-
terim Primary Drinking Water Regulations. Currently, for con-
taminants found at this site, California has promulgated MCLs for
benzene, ethylbenzene, and xylenes.
8.1.3 Ambient Water Quality Criteria
Adjusted EPA Ambient Water Quality Criteria (AWQCs) for
drinking water, and aquatic life are potentially ARARs for the
Koppers site (Table 8-1, Column 2). For potential carcinogens,
AWQCs are set at zero. For these carcinogens, concentrations as-
sociated with 10~6 excess lifetime cancer risks are also shown
(in parentheses) in Column 2 of Table 8-1.
-------
8910175t81 CON-1
Table 8-1. CHEMICAL-SPECIFIC POTENTIALLY APPLICABLE OR RELEVANT AND APPROPRIATE
REQUIREMENTS (ARARS), KOPPERS FEATHER RIVER SITE
Safe Drinking Drinking Water
Chemical
Water Act MCLsa
AWQC
d
Freshwater
Aquatic Life
AWQC9
Acute
(wg/i)
Chronic
(vg/i)
Benzene
Ethyl benzene
Isopropyl Ether
Methylene Chloride
Pentachlorophenol
Tetrachlorophenol
PAHs
Carcinogenic
Noncarcinogenic
PCDOs/PCDFs
Toluene
Xylenes
Formaldehyde
5(Db.
(680)b
220C
(l,750)b
0(0.67)
2,400
1,010
1.0
0(0.031)
0(0.00000018)e
15,000
20
13
Arsenic
Barium
Boron
Chromium
i jjer
. .el
50
1,000
50
1,000
"
0(0.25)
*.
. 750f
50
1,000
15
360
»_
WW
l,700(16)h
18
1,400
190
....
210(ll)h
12
160
c
d
f
g
Primary Maximum Contaminant Levels (MCLs), based on health-related considerations and
technological and economic feasibility of control, except for copper. For copper, the
MCL is an SMCL or Secondary Maximum Contaminant Level based on organoleptic effects.
These are ARARs.
Parenthetical values in the MCLs column are State of California maximum contaminant
levels. These enforceable limits are ARARs.
EPA-proposed maximum contaminant level goal (MCLG).
Adjusted EPA Ambient Water Quality Criteria (AWQCs) for drinking water only. AWQCs
for potential carcinogens are set at zero; values in parentheses are concentrations
associated with 10~° excess lifetime cancer risk. Criterion for copper is based on
organoleptic considerations.
EPA treats d1ox1n/furan Toxidty Equivalent Factors (TEFs) as equivalent to 2,3,7,8-
TCDD.
Boron AWQC is based on protection of sensitive crops during long-term irrigation.
EPA Ambient Water Quality Criteria for freshwater aquatic life only.
Acute values are 1-hour and chronic are 4-day criteria.
For trivalent and hexavalent (parenthetical values) chromium, respectively.
-------
-41-
8.1.4 California Total Threshold Limit Concentrations
Concentrations of hazardous waste constituents that may be
left in place in soil are regulated by Total Threshold Limit Con-
centrations (TTLCs) from California Administrative Code Title 22.
Chemical specific concentrations have been set for pen-
tachlorophenol (17 ppm), arsenic (500 ppm), chromium (2500 ppm),
and 2,3,7,8 Tetrachoro Dibenzodioxin (0.01 ppm).
8.2 ACTION-SPECIFIC ARARS
Ground water extraction and treatment involves pumping,
treating, and discharging the treated water to surface water or
reinjecting it into the aquifer. The treatment would involve
removal of contaminants by pretreatment followed by activated
carbon adsorption. Use of carbon adsorption may require con-
sideration of ARARs associated with disposal or regeneration of
the carbon. Surface water discharge or reinjection of treated
water must meet action-specific ARARs.
Soil remediation alternatives include excavation and treat-
ment, in situ treatment, and excavation followed by on-site or
off-site landfill disposal. There are action-specific ARARs cor-
responding to these options.
8.2.1. Discharge of Treated Effluentto Surface Water
Substantive National Pollutant Discharge Elimination System
(NPDES) permit requirements would apply to treated effluent dis-
charging to surface waters. These requirements would primarily
be effluent limitations and monitoring requirements. The
California Regional Water Quality Control Board (RWQCB) regulates
NPDES discharges. Ambient Water Quality Criteria and technology
based standards are used by the RWQCB to set NPDES effluent dis-
charge limitations.
Discharge to surface water would also be controlled under
the Porter-Cologne Water Quality Control Act regulated by the
RWQCB.
8.2.2 Reinjection of Treated Effluent Into Aquifers
If treated ground water is reinjected, regulations governing
underground injection may apply. Specifically, the Federal Safe
Drinking Water Act requires an Underground Injection Control
(UIC) program. In California, the UIC program is administered by
the U.S. EPA. For CERCLA cleanups, the UIC program regulates the
method and location of the injection. These Federal requirements
regarding injection are ARARs for the site.
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-42-
Federal RCRA requirements and the State's Toxic Injection
Well Control Act of 1985 (Cal. Health & Safety Code Section
25159.10 et seg.) are also ARARs for the reinjection of treated
ground water.
As in the case of surface discharge, reinjection of treated
ground water would be controlled under the Porter-Cologne Water
Quality Control Act regulated by the California RWQCB.
8.2.3 Air Emission Standards
Any new source that emits toxic chemicals to the atmosphere
at levels determined by the Butte County Air Pollution Control
District (BCAPCD) to be appropriate for review must have
authorization to construct and a permit to operate from this
agency. Although on-site treatment facilities are exempted by
CERCLA from the administrative requirements of the permitting
process, emission limits and monitoring requirements imposed by
the BCAPCD must be met.
8.2.4 Carbon Adsorption
Use of granular activated carbon for remediation of ground
water can trigger requirements associated with regeneration or
disposal of the spent carbon. If the spent carbon is a listed
waste or a characteristic waste under RCRA, then it is regulated
as a hazardous waste under RCRA and California's hazardous waste
control laws. Disposal of contaminants can trigger RCRA land
disposal restrictions. For disposal, the spent carbon would need
to be treated to meet Best Demonstrated Available Technology
(BOAT) treatment standards. RCRA off-site Subtitle C disposal
restrictions would also apply. Regeneration is preferred over
disposal.
Regeneration of activated carbon, using the Bi-Far system (a
biological process), is considered "recycling" under both Federal
and California hazardous waste regulations. Transportation,
storage, and generation of hazardous waste for recycling must
comply with requirements in RCRA and California hazardous waste
control regulations. On-site storage of contaminated carbon may
trigger substantive requirements under municipal or county haz-
ardous materials ordinances. If the spent carbon is considered a
hazardous waste, construction and monitoring requirements for
storage facilities may also apply.
8.2.5 Excavation. Treatment, and Disposal of Soil
Alternatives have been evaluated for remediating con-
taminated soil by a variety of methods including; (1) excavation
and soil washing, (2) in situ bioremediation, (3) on-site
landfill, (4) off-site landfill, (5) capping, and (6) excavation
and chemical fixation.
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-43-
Butte County APCD emission limits and monitoring require-
ments may be ARARs associated with these alternatives.
For the alternatives involving on-site and off-site
landfills (items 3 and 6 above), landfill siting and design must
be consistent with federal standards described in Code of Federal
Regulations 40 CFR Part 264, Subpart N; and state standards
described in California Administrative Code (CAC) Title 22, Divi-
sion 4, Chapter 30, Article 29, and CAC Title 23, Chapter 3, Sub-
chapter 15, Article 3.
In addition, the off-site landfill would be a Class I
landfill, in compliance with federal and state law governing haz-
ardous waste disposal off site.
The Koppers fire safety pond and its surroundings is a "wet
riparian habitat," and may be impacted by excavation associated
with soil washing, on-site landfill, and capping (items 1, 3, and
5 above). If so, requirements to repair or replace these wet-
lands consistent with EPA wetlands requirements and policies will
be met.
Excavation, treatment, and redisposal of soil in the western
portion of the Koppers site (Unit S2) is subject to RCRA land
disposal restrictions because RCRA K001 wastes will be "placed"
(under the RCRA Land Disposal Restrictions) there. The con-
centrations that cannot be exceeded for the "placement" of this
waste under the land disposal restrictions are:
Napthalene 8 mg/kg
PCP 37 mg/kg
Phenanthrene 8 mg/kg
Pyrene 7.3 mg/kg
Toluene 0.14 mg/kg
Xylenes 0.16 mg/kg
Remediation of Unit S4 could potentially be determined to be
treatment of hazardous waste as defined by RCRA. Two alterna-
tives for this unit involve "placement" of treated soil (S4-2,
S4-3). However, it appears that arsenic and chromium levels are
not high enough to qualify as RCRA waste. EP Toxicity tests have
not been performed, however they will be done during the Remedial
Design to verify that this is not RCRA waste. The RCRA Land Dis-
posal Restrictions are not ARARs for Unit S4 unless the EP
Toxicity tests show this to be RCRA waste.
Fixation of soil in Unit S4 (alternative S4-2) would need to
meet applicable standards for leachable contamination. These
would include the California Soluble Threshold Limit Concentra-
tions (STLC). The STLC for Arsenic is 5 mg/1 of leachate and for
chromium is 560 mg/1 of leachate.
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-44-
8.3 LOCATION-SPECIFIC.;ARARS '
8.3.1 Fault Zone
The Koppers site is not located within 61 meters (200 feet)
of a fault. Therefore, the fault zone requirement of 40 CFR Sec-
tion 264.18(a) is satisfied.
8.3.2 Floodplain
A hazardous waste treatment facility located in a 100-year
floodplain must be designed, constructed, operated, and main-
tained to prevent washout of any hazardous waste by a 100-year
flood. The Koppers site is located in a 100-year floodplain of
the Feather River. The requirements of 40 CFR Part 264.18(b)
must be met. This means that facilities such as the soil washing
unit will have to be designed, constructed, operated, and main-
tained to prevent washout from a 100-year flood.
8.4 TO BE CONSIDERED CRITERIA
In establishing selected remedial alternatives, EPA con-
siders various procedures, criteria, advisories, and resolutions.
These "to be considered" criteria (TBCs) do not carry the weight
of ARARs, but are relevant to the cleanup of the site. The fol-
lowing discussion presents selected criteria relevant to the
selection of remedial alternatives.
8.4.1 State Criteria for Ground water Cleanup
California's criteria for evaluating drinking water quality
and ground water cleanup are advisory Drinking Water Action
Levels and advisory Applied Action Levels respectively. These
criteria are presented in Table 8-2.
Drinking Water Action Levels are health-based concentration
limits set by the Department of Health Services (DHS) to limit
public exposure to substances not yet regulated by promulgated
standards.
Applied Action Levels (AALs) were developed by DHS for use
with the California guidanance in the "Site Mitigation Decision
Tree." AALs are guidelines that DHS uses to evaluate the risk a
site poses. While the DHS Applied Action Levels are not promul-
gated standards and are not, therefore, ARARs, they have been
taken into consideration in developing cleanup standards for the
Koppers site pursuant to the National Contingency Plan (NCP).
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8910175t81 CON-2
Tab-le 8-2. TO BE CONSIDERED ' (TBC) CRITERIA, KOPPERS FEATHER RIVER SITE
California DHS California DHS
Recommended Drinking Applied Action
Water Action Levels4 Levels (AALs)a
Chemical (yg/1) (
Benzene 0.70 0.70
Ethyl benzene 680 680
Isopropyl Ether
Methylene Chloride 40,
Pentachlorophenol 30° 2.2°
Tetrachlorophenol
PAHs
Carcinogenic « 0,023°
Noncarcinogenic ' « 19
PCDDs/PCDFs
Toluene 100 100
Xylenes 620 620
Formaldehyde 30
Arsenic
Barium
Boron
Chromium
Copper
Nickel
Recommended Drinking Water Action Levels and Applied Action Levels
(AALs) by the State of California, Department of Health Services
(DHS). These are not ARARs but are termed To Be Considered (TBC)
standards by EPA.
The California Drinking Water Action Level for pentachlorophenol is 30 ug/1
based on noncarcinogenic effects; the California Applied Action
Level (AAL) is 2.2 ug/1 based on 10"° excess lifetime cancer risk.
c
AAL for benzo(A)pyrene only, the most carcinogenic of the PAHs.
d The California Applied Action Level for noncarcinogenic PAHs applies to
the sum of 8 PAHs.
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-46-
8.4.2 California Resolution 68-16
Resolution 68-16 is California's "Statement of Policy With
Respect to Maintaining High Quality of Waters in California".
EPA regards Resolution 68-16 as criteria to establish ground
water cleanup levels. The policy requires maintenance of exist-
ing water quality unless it is demonstrated that a change will
benefit the people of the state, will not unreasonably affect
beneficial uses of the water, and will not result in water
quality less than prescribed by other state policies.
A beneficial use of the ground water in the aquifer system
is drinking water. Establishing a cleanup level which maintains
this beneficial use should attain the requirements of Resolution
68-16.
8.4.3 Centers for Disease Control Dioxin Advisories
The Centers for Disease Control (CDC) have advised EPA on
setting cleanup standards for Superfund sites with dioxins in
soils. Soils on sites that are currently or potential a residen-
tial area have been cleaned up to 1 ug/1. The CDC has also ad-
vised that industrial exposure should be limited to soils less
than 5-7 ug/1. No advisory level has been developed for agricul-
tural land usage, but current indication is that the level may be
less than that for residential or industrial land use.
9.0 Summary of Comparative Analysis of Alternatives
Twelve soil alternatives and two ground water alternatives
were evaluated and compared for the Koppers site. Each of the
alternatives were evaluated with respect to EPA's nine evaluation
criteria.
1) Overall protection of human health and the environment,
2) Compliance with ARARs,
3) Short term effectiveness in protecting human health and
the environment,
4) Long term effectiveness and permanence in protecting
human health and the environment,
5) Reduction of toxicity, mobility, and volume of
contaminants by treatment,
6) Technical and administrative feasibility of
implementation,
7) Capital and operation and maintenance costs,
8) Community Acceptance,
9) State Acceptance.
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-47-
A summary of the evaluation of alternatives with respect to
these criteria is presented in Tables 9-1 to 9-5. Since comments
on each alternative were not received from the State of Califor-
nia or the community, the last two criteria are not included in
the tables. A general discussion of state and community accept-
ance follows. A full documentation of all state and community
input is provided in the response summary.
A brief discussion of the comparison of alternatives follows
the sections on state and community acceptance.
9.1 State Acceptance
The State of California supports the treatment and disposal
options proposed by EPA, and has the following concerns or sug-
gestions regarding the selected remedies:
The cleanup level for dioxins/furans in soil should be
set at the 10"6 cancer risk level (30 ppt).
- The cleanup level for PCP in ground water should be
lower than the state action level of 2.2 ppb to account for other
carcinogens.
The majority of the comments raised by the state are
relevant to the Consent Decree for the Remedial Design/Remedial
Actions, or the details of the RD/RA. These concerns will be
saved for consideration at the appropriate time.
9.2 Community Acceptance
Except for one letter, all community comments were provided
during a public hearing on the proposed plan. Unified comments
on the proposed plan were not provided by any community group as
a whole. The following concerns from individuals were raised:
- Cleanup levels should not be greater than background.
- Soil fixation should not be used since it does not remove
contamination.
Several community comments also dealt with the implementa-
tion of the remedial action and can not be definitively addressed
at this time. These will be considered at the appropriate time.
9.3 Comparative Analysis of Alternatives for Unit SI
The alternatives evaluated for unit SI are excavation and
soil washing (Sl-1), in situ biodegradation (Sl-2), excavation
and onsite landfilling (Sl-3), and limited excavation and capping
(Sl-4). All alternatives are evaluated in Table 9-1.
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-48-
Alternatives Sl-3, and Sl-4 do not provide adequate overall
protection of human health and the environment, or comply with
ARARs. Sl-4 has problems in long-term effectiveness, since it
will not achieve remedial objectives. Neither Sl-3 nor Sl-4
reduces toxicity, mobility and volume by treatment.
Both Sl-1 and Sl-2, are protective, would comply with ARARs,
and involve treatment to reduce toxicity, mobility and volume of
contamination. In comparing alternatives Sl-1 and Sl-2, the
major differences are in short-term effectiveness and cost. The
excavation associated with Sl-1 would require extensive dust con-
trol measures to prevent airborne contaminant migration, that are
not necessary with the insitu treatment in Sl-2. Costs of Sl-1
exceed those of Sl-2 by nearly 50%
9.4 Comparative Analysis of Alternatives for Unit S2
The alternatives evaluated for Unit S2 are excavation and
soil washing (S2-1), excavation and onsite landfilling (S2-2),
and limited excavation and capping (S2-3).
The comparative analysis in Table 9-2 shows that alternative
S2-1 provides superior protection of public health and the en-
vironment and compliance with ARARs. Alternative S2-1 is also
the only alternative for this unit that will reduce toxicity,
mobility and volume by treatment.
9.5 Comparative Analysis of Alternatives for Unit S3
The alternatives evaluated for Unit S3 are no action (S3-1),
and limited excavation, with capping and containment of ground
water contamination by the installation of extraction wells (S3-
2). These alternatives are evaluated in Table 9-3.
Alternative S3-2 provides protection of human health and the
environment, while alternative S3-1 does not. It is important to
note that the actions evaluated for unit S3 are not intended as
permanent remedies for these soils. These soils will be
remediated in a manner consistent with other site soils when they
are accessible.
9.6 Comparative Analysis of Alternatives for Unit S4
The alternatives evaluated for Unit S4 are no action (S4-1),
excavation and chemical fixation (S4-2), and excavation and off-
site disposal (S4-3). The evaluation of these alternatives is
presented in Table 9-4.
Both S4-2, and S4-3 are superior to S4-1 for their protec-
tiveness of public health and the environment and compliance with
ARARs. S4-2 has advantages over S4-3 in that it reduces toxicity
and mobility through treatment, and is more cost effective than
S4-3.
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-49-
9.7 ' Comparative Analysis of Alternatives for Ground Water
The alternatives for remediation of ground water both in-
clude extraction and treatment of contaminated ground water by
carbon adsorption. Alternative Gl involves disposal of treated
ground water by discharge to surface water, and Alternative G2
involves disposal of treated ground water back to the ground
water. The comparison of these alternatives is presented in
Table 9-5.
In comparing these alternatives differences appear in over-
all protection of human health and short-term effectiveness. The
reinjection of water in G2 could also be used for hydraulic con-
trol to prevent contamination from migrating into now uncon-
taminated areas. This provides added protection of public
health. Reinjection can also facilitate the removal of con-
tamination by flushing contaminants from the aquifer. This may
result in reaching remedial objectives quicker, thus improving
short-term effectiveness.
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Tat L|. COMPARATIVE ANALYSIS OF ALTERNATIVES, SOIL UNIT SI
AIternatlve t:
Sl-l
SI-2
SI-3
SI-4
Description of
AIternatIves
Excavate and Mash 110,000 cu.
yd. contaminated soil, backfill
110,000 cu. yd. treated soil.
Overall Protection Protection achieved by
of Human Health & significant reduction of PCP
Environment and other contaminants In SI
soils.
Compliance with
ARARs
The California TTLC standards
for arsenic, chromium, and PCP
are expected to be met. RCRA
Land Disposal Restrictions
compliance likely to be
achieved.
In situ soil biodegradation
utill/ing soil application of
enriched water and water
treatment system.
Protection achieved by
significant reduction of PCP
and other contaminants in SI
sol Is.
The California TTLC standards
for arsenic, chromium, and PCP
are expected to be met.
Excavate 110,000 cu. yd.
contaminated soil, construct
RCRA Class I landfill on site,
backfill 110,000 cu. yd. soil.
Protection achieved by
containing PCP and other
contaminants in a secure
landfi11.
Landfill siting and design must
be consistent with federal RCRA
and State Title 22 standards.
RCRA Land Disposal Restrictions
compliance not likely to be
achieved. Excavated soil will
not likely meet RCRA Land
Disposal Restrictions.
Excavate to limited depth,
grade and pave 869,300 sq. ft.
of soil to establish a low
permeab iIi ty cap.
Limited protection achieved by
containing PCP and other
contaminants beneath a low
permeability cap. Likely
adverse impact on meeting
groundwater remedial
objectives.
California TTLCs cannot be met
without deep excavation in
addition to the capping.
Short-Term Excavation over a large area
Effectiveness will require dust control
measures. The time required to
meet remedial response
objectives is estimated to be
10 to 15 years.
A localized rise in the water . Excavation will require dust
table, change in soiI
chemistry, or microbial
population may result from
applications of water and
nutrients to the soil. The
time required for meeting
remedial response objectives is
estimated to be 20 years.
control measures. The time
required to complete the
landfill is estimated to be I
to 3 years. Federal and state
approval is the critical time
factor.
Limited excavation and grading
will require dust control
measures. The time required to
install the cap Is estimated to
be I to 2 years.
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Table 9-1. COMPARATIVE ANALYSIS OF ALTERNATIVES, SOIL UNIT SI (continued)
Alternative /:
Sl-l
Sl-2
S1-3
S1-4
Long-Term
Effectiveness
Reduction of
Toxiclty,
Mobility, and
Volume Through
Treatment
ImplementabiIIty
Soil washing removes soil as a
source of further groundwater
contamination. Operation and
maintenance of the soil washing
equipment Is complex but
manageable. Controls to
prevent washwater spills will
enhance re I lab 11ity. Washwater
treated on-site. Long-term
effectiveness will be further
evaluated during design in
treatability studies.
Combined with treatment of
washwater, soil washing is
effective in reducing toxicity,
mobility, and volume (TMV) of
PCP, the major contaminant of
SI.
Performance can be monitored by
chemical analysis of soil and
washwater; ready availability
of equipment and specialists,
and storage/disposal services
for residuals.
In situ biodegradation will
eliminate contaminated soil as
a source of further groundwater
contamination. Reliability
enhanced by controls to prevent
water spills and shut down
processing in the event of
operational failures. Long-
term effectiveness will be
further evaluated during design
in treatability studies.
Initial increase in mobility of
PCP to enable biological
processes to act on the contam-
inant. Groundwater extraction
wells designed to confine
groundwater to soils involved
in biodegradation system.
Permanent reduction in TMV.
Technical feasibility
promising. It is possible that
the subsurface environment may
present difficulties not iden-
tified with currently available
soiI/groundwater data. System
performance can be monitored.
System components readily
aval(able.
Disposal to an on-site secure
landfiII will eliminate the
contaminated soil as a source
of further groundwater
contamination. Long-term
management, operation, and
maintenance is routine.
Landfill containment is a
proven technology for long-term
management of solid waste.
Monitoring wells and leachate
monitoring will enhance
re I lab 11Ity.
No reduction of TMV through
treatment.
Technical feasibiIity of this
proven technology is
promising. Groundwater and
leachate monitoring system will
insure performance of landfill.
Containment of soil reduces
risks of further surface water,
groundwater, and airborne dust
contamination. Capping is a
proven technology for reducing
management requirements of
contaminated soil. Occasional
maintenance and replacement of
portions of the asphalt may be
required. Likely adverse
impact on groundwater remedial
objectives.
No reduction of TMV through
treatment.
Readily imp lamentable. Asphalt
material and installation
contractors are available
locally.
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69IOI75T10 CON-3
Table 9-1. COMPARATIVE ANALYSIS OF ALTERNATIVES, SOIL UNIT SI (concluded)
Alternative t:
Sl-1
SI-2
SI-3
SI-4
Cost
Capital
Net Present Month
S7.1 ill Ion
S17.1 all I Ion
14.5 mi I I ion
S12.2 million
12.23 mi II ion
16.50 million
S8.35 mi 11 ion
$8.50 mi 11 ion
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BdlOI75-TX CON-1
Table 9-2. COMPARATIVE ANALYSIS OF ALTERNATIVES, SOIL UNIT S-2
Alternative I:
S2-I
S2-2
S2-3
Description of
Alternatives
Overall Protection
of Human Health &
Environment
Compllance with
ARARs
Short-Term
Effectiveness
Excavate up to 200,000 cu. yd.
contaminated soil, wash soil and treat
washwater, backfill and grade 200,000
cu. yd. sol I.
Protection achieved by significant
reduction of creosote and other
contaminants In S2 soils. Long-term
risks to human health reduced,
environmental protection enhanced.
Soil treatment process may be considered
a hazardous waste treatment process. If
so, the applicable TTLC standards and
RCRA LORs are expected to be met.
Potential risk from airborne dust Mill
need to be mitigated. Time required to
complete the landfill is estimated to be
10 to 15 years.
Excavate 200,000 cu. yd. soil, backfill
Into RCRA Class I on-site landfill.
Protection achieved by containing
creosote and other contaminants In a
secure landfill. Landfill Mill reduce
the mobility of the contaminants,
thereby reducing long-term risks to
humans and enhancing environmental
protection.
Will not meet the RCRA land disposal
restrictions.
Potential risk from airborne dust Mill
need to be mitigated. Time required to
complete the landfill is estimated to be
I to 3 years.
Excavate to limited depth, grade and
pave 800,000 sq. ft. of soil to
establish a low permeability cap.
Limited protection achieved by
containing creosote and other
contaminants beneath a low permeability
cap. Likely adverse impact on meeting
groundwater remedial objectives.
Capping may not be sufficient by Itself
to protect groundwater. Excavated,
untreated soil will not meet RCRA Land
Disposal Restrictions. Capping without
deep excavation will not meet California
TTLC standards.
Potential risk from airborne dust will
need to be mitigated. Time required to
complete construction of a cap is
estimated to be I to 2 years.
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8910175-TX CON-2
Table 9-2. COMPARATIVE ANALYSIS OF ALTERNATIVES, SOIL UNIT S-2 (concluded)
Alternative i:
S2-1
S2-2
S2-3
Long-Term
Effectiveness
Reduction of
Toxlclty. Mobility.
and Volume Through
Treatment
Implementabl11ty
Soil washing Mill reduce long-term risk
of further groundwater contamination.
Equipment operation and maintenance is
complex but manageable. The system Mill
include controls to prevent washwater
spills and shut down processing in the
event of failures. Washwater will be
treated onslte.
Contaminants are amenable to soil
washing and are Irreversibly destroyed
by microbial action of washwater
treatment. Volume, mobility, and
toxlcity of creosote In soil reduced.
Readily implementable. Viscosity of
creosote may present special technical
problems that can be resolved.
Disposal to an on-site secure landfill
provides a method to eliminate soil as a
source of further groundwater
contamination. Landfill containment is
a proven technology. Clay liners,
monitoring wells, and leachate control
systems provide a highly reliable
containment system.
No reduction of TMV through treatment.
Readily Implementable. Landfill
performance will be monitored by
chemical analysis of leachate and nearby
groundwater.
Containment reduces long-term risk of
further airborne dust contamination, and
surface water infiltration to
contaminated soil. Capping Is a proven
technology for reducing management
requirements of contaminated soil. Does
not meet remedial objectives due to
continued leaching of soil contaminants'*
into groundwater.
No reduction of TMV through treatment.
Readily implementable. Asphalt material
and installation contractors are ''_
available locally. Low probabiIity thatt:
technical problems will involve schedule
delays.
Cost
Capital
Net Present Worth
$7.1 million
$14.6 million
S2.63 million
$10.20 ml 11 Ion
$7.7 mi 11 ion
$8.0 mi 11 Ion
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Table 9-3. COMPARATIVE ANALYSIS OF ALTERNATIVES. SOIL UNIT S3
Alternative
S3-1
S3-2
Description of
Alternatives
No remedial action. Only Institutional actions and groundwater
monitoring Mill be performed under this alternative.
Overall Protection Not protective, but It Mill contribute in combination with
of Human Health & actions taken at other units.
Environment
Excavate, grade and cap with concrete 308,000 sq. ft. of the
process area and drip track, drill two extraction wells for
groundwater pumping to Insure containment of contaminated water
beneath the facilities. Concrete cap to contain contaminants
and support manufacturing activities.
Protect Iveness achieved by containing contaminants beneath
impermeable cap and by groundwater pumping.
Compliance with Does not comply,
ARARs
Short-Term
Effectiveness
Long-Term
Effectiveness
Reduction of
Toxlclty,
Mobility, and
Volume Through
Treatment
No potential health risks or environmental Impacts through
remediation activities. Won't meet remedial objectives.
Monitoring Metis to detect contamination from the process area
are reliable tools. This alternative Mill not meet remedial
objectives.
No reduction of TMV through treatment.
Capping by Itself Is Insufficient to protect groundwater.
Combined with proposed pump and treat system, however, capping
will contribute to compliance. Capping without significant
excavation will not achieve California TTLCs for arsenic,
chromium, or PCP.
Potential risks from airborne dust contamination will need to
be mitigated. Time required to Implement remedy is estimated
to be I to 2 years.
Containment can reduce soil as a source of further groundwater
contamination. Adequate hydraulic control of groundwater
beneath the process area will be provided by extraction
wells. Capping is a proven technology for reducing management
requirements of contaminated soil.
Mobility of soil contaminants will be reduced by groundwater
pumping and treatment.
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Table 9=3. COMPARATIVE ANALYSIS OF ALTERNATIVES, SOIL UNIT S3 (concluded)
Alternative t:
S3-I
S3-2
ImplementablIIty Technically and administratively feasible.
Technically feasible. Concrete material and installation
contractors available locally. Performance can be monitored by
chemical analysis of nearby monitoring Me I Is.
Cost
Capital
Net Present Worth
S63.250
1340,000
$978,000
SI.2 mil I ion
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8910175-TX CON-S
Table 9-4. COMPARATIVE ANALYSIS OF ALTERNATIVES, SOIL UNIT S4
Alternative *:
S4-1
S4-2
S4-3
Description of
AIternatlves
Overall Protection
of Human Health &
Environment
Compllance with
ARARs
Short-Term
Effectiveness
No remedial action. Soil sampling and
groundwater monitoring are the only
activities performed under this
alternative.
Not protective.
This alternative Mill not meet the
California TTLC ARAR.
No potential health risks or
environmental Impacts through
remediation activities. This
alternative will not meet remedial
objectives.
Chemically fixate 4,000 cu. yd. soil to
contain contaminants.
Protection achieved by immobilizing
arsenic and chromium.
This alternative is expected to meet the
California TTLCs for arsenic and
chromium leachate.
Potential risks from airborne dust
contamination will need to be
mitigated. Time required to meet
remedial action objectives is estimated
to be t to 2 years.
Excavate 4,000 cu. yd. contaminated
soil, backfill 4,000 cu. yd. soil, grade
84,600 sq. ft. soil. Transport and
dispose off site 4,000 cu. yd.
contaminated soil.
Protectiveness achieved by removing
contaminated soil to an off-site secure
Class 1 landfill.
This alternative is expected to meet
ARARs by removing contamination.
Potential risks from airborne dust
contamination will need to be
mitigated. Time required to meet
remedial response objectives is
estimated to be I to 2 years.
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Tablo r-4. COMPARATIVE ANALYSIS OF ALTERNATIVES, SOIL UNIT S4 (concluded)
Alternative
S4-1
S4-2
S4-3
Long-Term
Effectiveness
Reduction of
Toxiclty, Mobility,
and Volume Through
Treatment
ImplementabiIIty
Monitoring wells to detect contamination
are reliable tools. Access restrictions
can reliably reduce unintentional
trespass.
No reduction of TMV through treatment.
Readily Implementable.
Fixation reduces the potential for soil
to contaminate groundwater and,
therefore, reduces the long-term risk of
further groundwater contamination. The
utility of the fixation method for
arsenic and chromium must be tested
during remedial design. Soils are
expected to remain fixed over the long
term with little required maintenance.
Fixation reduces the toxicity and
mobility of contaminants.
Readily implementable; the probabiIity
that technical problems will result in
schedule delays is low.
Disposal to a secure landfill eliminates
contaminated soil as a source of further
groundwater contamination. Landfill
containment is a proven technology for
long-term management of solid waste.
Long-term management is left to the
disposal vendor, who is required by RCRA
to perform long-term monitoring and
maintenance.
. ' '?,
No reduction of TMV through treatment.' ,
Readily implementable.
Cost
Capital
Net Present Worth
$12,500
$289,000
$500,000
$1.0 mi I lion
$0
$1.7 mi 11 ion
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8910175T10 CON-4
Table 9-5. COMPARATIVE ANALYSIS OF ALTERNATIVES, GROUNDWATER UNIT
Alternative I:
Gl
G2
Description of
Alternatives
Overall Protection
of Human Health
and Environment
Compliance with
ARARs
Short-Term
Effectiveness
Long-Term
Effectiveness
Reduction of
Toxicity,
Mobility, and
Volume Through
Treatment
ImplementabiIity
Construct groundwater extraction wells and carbon treatment
facility, extract and treat contaminated groundwater, discharge
treated Mater to surface Mater. Pre-treatment required for on-
slte groundwatar to remove suspended solids and oils. Proposed
biological treatment of contaminated carbon filters.
Implementation of extraction and treatment systems Mill reduce
the mobility, volume, and toxicity of contaminants, resulting
In reduction of potential health risks and increased protection
of the environment.
System designed to comply with contaminant-specific ARARs
specified in Koppers EA and Proposed Plan. RWQCB discharge
permit required.
Clean-up risk Mill be controlled. The time required to meet
remedial response objectives Is estimated to be 20 to 30 years.
Likelihood that performance specifications Mill be achieved is
high. Technical components of the system are simple and
readily available. Acceptability of residuals for off-site
disposal Is not anticipated to be difficult.
PCP and other contaminants removed by treatment process.
Residuals may be treated on site in process to be studied
during remedial design. Volume, chemical characteristics, and
proper disposal of residuals Mill be determined during remedial
des i gn.
Technical feasibility is promising. Surface water discharge
subject to RWOCB discharge requirements. RWOCB nondegradation
requirements in effect.
Same as Gl except that treated water discharged to recharge
Mel Is.
Same as Gl; recharge of treated groundwater will help control
further migration of contamination.
Same as Gl; ARARs for underground injection will need to be
met.
Samd as Gl; recharge of treated groundwater will result in more
expeditious achievement of remedial objectives.
Samtf as Gl.
Same as Gl.
Same as Gl. RWQCB nondegradation policy also applies to
groundwater recharge.
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Tat ,-5. COMPARATIVE ANALYSIS OF ALTERNATIVES, GROUNDWATER UNIT (concluded)
Alternative t: Gl G2
Cost
Capital J22.6 million $23.1 mi 11 ion
Net
Present North $48.6 mi 11 ion $48.7 mi 11 ion
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10.0 Selected Remedy
10.1 Selected Soil Remedies
The soil cleanup goals for the major contaminants at the
Koppers site are 17 ppm for PCP, 30 ppt for dioxins/furans, back-
ground for arsenic and chromium, and 0.19 ppm for carcinogenic
PAHs. (See Table 10-1) Soil cleanup goals were set to meet 10~6
risk targets for total exposure to carcinogens under a potential
future residential scenario, or more stringent available state
standards.
10.1.1 Unit SI - In situ Biodegration
The selected remedial action for soil area SI is in situ
biodegradation. Approximately 110,000 cubic yards of soil con-
tain contaminants in concentrations greater than the site
remediation goals. The goals especially applicable to this area
are 17 ppm pentachlorophenol and 30 ppt dioxins/furans.
Treatability study work provided by Koppers from other sites has
shown promising reductions in PCP using this approach. Site
specific treatability studies will be performed during design to
develop all operating parameters. Attention will be given to the
most effective approach to be used for application of the en-
riched water to the soil. Attention will be given to preventing
any air contaminant migration during the application of water.
During implementation of this action performance will be
monitored by analyses of soil and water pumped from extraction
wells.
All costs presented in this ROD are present worth costs.
It is estimated that remedial objectives for this unit will
be achieved in approximately 20 years. Total capital costs for
this remedy include extraction wells, a soil irrigation system,
and a water treatment system.
These capital costs have been estimated as: $ 4.5 million
Operating costs, including monitoring, water treatment,
and well maintenance total: $ 7.7 million
Total costs for Area 81: $ 12.2 million.
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TABLE 10-1 - SUMMARY OF MAJOR'1' REMEDIAL OBJECTIVES
Total Carcinogenic Dioxins/ Arsenic, PCP
PAHs Furans Chromium
Soil 0.19 ppm 30 ppt background^ 17 ppm
GW 7 ppt 0.53 ppq* background^ 2.2 ppb
+ - The remediation goals for these four contaminant groups cor-
respond to all goals specified in Table 2-3 of the Feasibility
Study report since the remedy selected is expected to meet all
goals when these four have been achieved. These were selected
for this table for brevity, and because they have the most exten-
sive impacts on the volumes to be remediated. Remedial objec-
tives for all contaminants of concern are required to be met.
ppm = parts per million
ppb = parts per billion
ppt = parts per trillion
ppq = parts per quadrillion
# - The objectives for remediation of arsenic and chromium are to
address all levels above background. The exact background con-
centrations will be determined during remedial design.
* - Verification of achievement of the goal is limited currently
to the analytical detection limit of 25 ppq. Since the remedial
action is expected to take 20-30 years, it is expected that sig-
nificant improvement in analytical methods will be achieved
during implementation. Therefore, the remedial goal remains 0.53
ppq, and the analytical detection limit will remain the means of
verification as it is improved.
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10.1.2 Unit 82 - Excavation and Soil Washing
The selected remedy for soil area S2 is excavation, soil
washing, and redisposal of the treated soil. Approximately
200,000 cubic yards of soil exceed the site remediation goals.
Those goals especially applicable are 17 ppm pentachlorophenol,
30 ppt dioxins/furans, and 0.19 ppm total carcinogenic PAHs.
Oust control measures will be necessary during implementation to
prevent airborne migration of contaminants. Treatability
studies from other sites has shown promising reduction of PCP and
PAHs using soil washing techniques. The details of the washing
process, including the types of additives used to promote con-
taminant extraction, and the number of washing steps necessary,
will be determined during remedial design when site specific
treatability studies will be performed. Performance of the sys-
tem will be monitored by chemical analyses of soil entering and
leaving the system, and of wash water.
Wash water from this process will be handled in an on-site
wastewater treatment system. After treatment wash water may be
recycled back into the soil washing system.
It is estimated that remedial objectives will be met for
this unit in 10 to 15 years. Total capital costs, including soil
washing equipment, the wash water treatment system, and indirect
capital costs such as engineering and design, and construction
are approximately: $ 7 million.
Operating costs including sampling, excavation, backfilling,
grading, and process operations come to: $ 7.6 million.
Total costs for area 82: $ 14.6 million
10.1.3 Unit 83 - Capping with Ground water Extraction
Area S3 will be remediated by the installation of a low per-
meability cap over the currently active wood treating process
area, along with the installation of extraction wells to contain
contaminated ground water migrating from this area. For the pur-
poses of this Record of Decision, it has been concluded that this
soil can be left in place while plant operations continue without
adverse impacts on the surrounding environment. This conclusion
will be verified after implementation of the remedy. This is not
considered a permanent remedy for this soil. The intent of the
selected remedy is to allow continued plant process operations
while controlling migration of airborne dust from contaminated
soils and preventing the migration of contaminated ground water
away from this unit. When the soil is accessible, i.e. when wood
treating operations cease, or when process equipment is replaced,
these soils will be remediated to the overall goals of 17 ppm
pentachlorophenol, 30 ppt for dioxins, 0.19 ppm for carcinogenic
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,,.. . ... .
' -64- ' ' '
PAHs, and background concentrations for metals (Arsenic and
Chromium). Approximately 20,000 cubic yards of soil are con-
taminated above these concentrations.
The selected remedial action will involve limited excavation
to facilitate installation of the cap. The excavated soil will
be handled with soil from unit S2. The cap will also serve as a
drip track. It will be graded to collect spills and storm water.
These waters will be handled in the onsite wastewater treatment
unit.
The cap and extraction wells are expected to be operational
in 1 to 2 years. Pumping of the extraction wells will continue
for approximately 20 to 30 years. Capital costs for this action
include excavation and grading, installation of a drip track, ex-
traction well installation, and indirect capitol costs such as
engineering and design. These costs total approximately:
$ 1 million
Operating costs are primarily ground water monitoring expenses
and are approximately: $ 2Ot),000
Total costs for Area 83: $ 1.2 million
10.1.4 Unit 84 - Excavation and Fixation
The selected remedy for Area S4 is excavation and chemical
fixation. This action will need to be taken on soils with ar-
senic and chromium concentrations above background. The back-
ground concentrations of these metals will be determined during
remedial design. If the volume of soil with metals levels above
background is sufficiently low to make -this remedy not cost ef-
fective, EPA will consider allowing the soil to be disposed of at
a permitted offsite facility.
Excavation and soils handling operations will require dust
control measures to prevent the generation of airborne con-
taminants. The exact mixture of fixation chemicals, along with
other process parameters, will be determined during treatability
studies as part of the remedial design.
It is estimated that this remedial action can be implemented
in one to two years. In order to estimate costs, it was assumed
that 4000 cubic yards of soil exceed the remedial objectives.
Capital costs will include process equipment and indirect costs
such as design and contruction costs. These costs will be
approximately: $ 500,000
Operation costs include the costs for fixation chemicals, excava-
tion and backfilling, and chemical analyses. These costs are es-
timated as: $ 500,000
Total costs for area 84: $1.0 million
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10.2 Selected Ground water Remedies
10.2.1 Remediation of Contaminated Ground water
The selected ground water remedy includes extraction of con-
taminated water, treatment with activated carbon, and disposal of
the treated water by injection wells. In order to meet remedial
objectives for both on and offsite ground water, it is estimated
that 6 x 10s cubic feet of ground water will need to be treated.
Remedial objectives for ground water are based on the more
stringent of 10~6 excess cancer risks from use of ground water as
a drinking water supply or state action levels. These objectives
are 2.2 ppb pentachlorophenol, 7 ppt total carcinogenic PAHs,
0.53 ppg dioxins, and background levels of arsenic and chromium.
If the remedial objective for dioxins cannot be achieved due to
analytical limitations, the objective will be the lowest avail-
able detection limit. Remedial Objectives are presented in Table
10-1.
Onsite ground water contains metals and oil in some loca-
tions. These components will need to be removed by pretreatment
prior to use of carbon to meet discharge requirements.
Onsite disposal of treated ground water (defined as disposal
within the site boundaries or within the contaminated area) will
jieed to comply with the substantive details of California
Regional Water Quality Control Board permit requirements for
disposal to ground water.
Carbon regeneration will be handled onsite in a biodegration
process that will be demonstated during treatability studies as
part of remedial design.
The ground water remediation will need to operate for an es-
timated 20 to 30 years. Capital costs for the ground water
remediation include installation of extraction wells, recharge
wells, treatment equipment, along with indirect capital costs
such as engineering and design, construction and permitting.
These costs come to approximately: $23.1 million
Operation and maintenance costs include monitoring, well main-
tenance, treatment system operation and maintenance for a total
of: $ 25.6 million
Total costs for ground water: $ 48.7 million.
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-66-
10.2.2 Provision of Alternative Water Supply
The selected ground water remedy also includes the
provision of an alternative water supply to prevent the use of
contaminated residential wells and the use of wells that could
adversely impact the ground water remediation. Thus residents
that currently receive domestic water from an alternative supply
would be provided with sufficient water for all uses (including
irrigation). If contamination above EPA's remedial objectives is
found in residential wells that are not serviced by an alterna-
tive supply, the supply will need to be extended to these wells.
If it is determined that the use of any well adversely affects
the ground water remediation, an alternative supply will need to
be provided to this user.
11.0 Documentation of Revisions to the Proposed Plan
In the proposed plan, the remedial objective for dioxins in
soils was presented in the range from 30 parts per trillion
(ppt), to 1 part per billion (ppb). The 1 ppb level is the Cen-
ters for Disease Control's recommended remedial objective for Su-
perfund sites. This may be adjusted to reflect unique site cir-
cumstances and additivity of risk from multiple carcinogens.
Comments on this range of objectives for dioxins (30 ppt - 1
ppb) were received during public comment on the proposed plan.
Input from the State of California agencies and community were
considered as modifying criteria (see Section 9 for a discussion
of EPA's nine evaluation criteria). The comments supported the
30 ppt cleanup goal.
As this Record of Decision documents, remediation of soils
by in situ biodegradation and soil washing will be further tested
during Remedial Design to demonstrate effectiveness in reducing ~
the levels of dioxins. The RI/FS developed by Koppers indicated
that dioxin levels in soil might be reduced by insitu biodegrada-
tion and soil washing in areas SI and S2 respectively. EPA has
decided that since these innovative technologies have not been
demonstrated to achieve treatment goals and implementation is ex-
pected to take 20-30 years, the treatment goal for dioxins is ap-
propriately set at 30 ppt, which must be achieved by the in situ
biodegradation and. soil washing processes to the maximum extent
practicable. Should the technologies fail to achieve the 1 ppb
level at a minimum, this ROD will require amendment to select
further remedial action. This approach is within an acceptable
risk range.
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12.0 Statutory Determinations
The selected remedies are protective of human health and the
environment as required by Section 121 of CERCLA. Existing or
potential risks from exposure to soils and ground water will be
addressed by treating contamination, stabilizing contamination,
and by containing contaminants. Remedial objectives are to
reduce excess cancer risks to 10~°6 when possible (if background
levels of chemicals do not exceed this risk level), and will
reduce risks to within the 10~4 to 10~7 risk range. Risks from
noncarcinogens will be reduced to hazard indices less than one.
During the implementation of the remedy, engineering con-
trols will be utilized to ensure that contaminant releases do not
pose unacceptable risks. As an example, when contaminated soil
is handled and treated, it will be necessary to take dust control
measures to prevent the airborne migration of contaminants.
The selected remedies will comply with ARARs and TBCs. The
selected remedies will meet Safe Drinking Water Act MCLs, and the
California DHS Applied Action Levels for drinking water.
The remediation of contaminated soils will comply with the
RCRA Land Disposal Restrictions (LDRs) where applicable. LDRs
are applicable to CERCLA actions only when they constitute place-
ment of RCRA-restricted wastes. RCRA-restricted wastes are found
cncite in area S2 and potentially in area S4. If the waste is
consolidated or otherwise moved within the area of contamination,
LDR is not an ARAR since placement is not involved* If a RCRA
waste is present that does not currently have a treatment stan-
dard (to be determined in this case by EP toxicity for area S4)
and placement occurs after the waste is restricted, the remedy
must comply with LDR. If treatment cannot meet del1sting
criteria or BOAT standards, a treatability variance may be
sought.
During implementation of the remedies, the substantive re-
quirements of the Butte County Air Pollution Control District
will be met.
The aforementioned protectiveness and compliance with en-
vironmental requirements is achieved in a cost effective manner.
The alternatives chosen are the cost effective approaches avail-
able to achieve the necessary degree of protectiveness. Remedial
actions for soils in area S4 could change if it is determined
that the volume of soil to be addressed can be more cost effec-
tively addressed by disposal at an offsite facility.
The selected remedies utilize permanent solutions and alter-
native technologies to the maximum extent possible. Remedial ac-
tions for soils at SI, S2, and S4 will consist of permanent solu-
tions. The ground water remedy is also a permanent solution.
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The containment of contaminated soil at area S3 is not a per-
manent solution but is protective while being cost effective in
minimizing disruption of the manufacturing processes at the site.
It should be noted that this ROD calls for a long term remedy of
soil in S3, when it is accessible, which would be a permanent
solution.
In situ bioremediation, soil washing, and bioregeneration of
activated carbon are all innovative, alternative technologies
that are part of the selected remedy.
The selected remedies also satisfy CERCLA's preference for
treatment as the principle element to reduce toxicity, mobility,
and volume of contamination. Remediation of soil units SI and
52, along with the ground water remedy will be treating con-
tamination to reduce toxicity, mobility and volume. The. approach
selected to address soil in S3 will only treat to reduce mobility
of contamination. Due to the nature of this contamination, this
soil cannot be treated to reduce toxicity and volume without ex-
cavating the soil. This cannot be done without unnecessarily
disrupting wood treating operations.
The selected remedy for soil in unit S4 involves treatment
to address mobility and toxicity. This approach effectively
protects public health in a cost effective manner. The total
volume of the treated Material will be in excess of the original
waste volume, because of the addition of a fixation agent.
The five year review required by section 121 of CERCLA is
applicable to these remedial actions. Those actions that will
result in permanent destruction of the contamination will not be
completed within five years of implementation of the remedies.
The selected actions at S3 and S4 will leave some hazardous sub-
stances onsite, and it will be necessary to periodically review
the effectiveness of the remediation.
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KOPPERS SUPERFUND SITE
OROVILLE, CALIFORNIA
OPERABLE UNIT RECORD OF DECISION
United States Environmental Protection Agency
Region"IX - San Francisco, California
September, 1989
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KOPPERS RECORD OF DECISION
TABLE OF CONTENTS
SECTION .
Declaration 1
Decision Summary 4
1.0 Site Name, Location, Description 4
2.0 Site and Enforcement History 6
3.0 Community Participation 9
4.0 Scope and Role of Decision 10
5.0 Summary of Site Characteristics 11
6.0 Summary of Site Risks 17
7.0 Description of Alternatives 30
8.0 Applicable and Relevant and Appropriate
Requirements (ARARs) and To Be Considered
Criteria 38
9.0 Summary of Comparative Analysis
of Alternatives 46
10.0 Selected Remedy 61
11.0 Documentation of Revisions to the
Proposed Plan 66
12.0 Statutory Determinations 67
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