United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R09-93/095
June 1993
EPA Superfund
Record of Decision
McColl, CA
-------
50272-101
REPORT DOCUMENTAT10N 11. REPORT NO. 2. 3. Recipient'. Acc8nIon No.
PAGE EPA/ROD/R09-93/095
4. Title .nd Subtitle 5. R.port Date
SUPERFUND RECORD OF DECISION 06/30/93
McColl, CA 6.
Second Remedial Action
7. Author(.) 8. Performing Organization Rlpl. No.
8. Performing Organization Name and Addr- 10 ProJect Ta8klWork Unit No.
11. Contract(C) or Grant(G) No.
(C)
(G)
12. Sponeorlng Organization Name and Add,... 13. Type of Report & Period Covered
U.S. Environmental Protection Agency
401 M Street, s.w. 800/800
Washington, D.C. 20460 14.
15. Supplementary Note.
PB94-964520
16. Abstract (Limit: 200 worda)
The McColl site is a former refinery waste disposal site located in a residential area
of Fullerton, Orange County, California. Based on the topography of the site and the
former site development features, the site can be divided into three general areas: the
Ramparts area, the Los Coyotes area, and the staging and parking area. The former
disposal area is located within the Ramparts and Los Coyotes areas and consists of 12
sumps; six in each area. From 1942 to 1946, approximately-72,600 yd3 of sludge was
disposed of into the 12 onsite waste disposal sumps. During the 1950s and early 1960s,
three sumps in the Ramparts area were covered with drilling mud in an attempt to
mitigate site odors. At an unknown date, arsenic-containing waste of an unknown origin
was disposed of in another of the Ramparts area sumps. During the late 1950s, the Los
Coyotes sumps were covered with natural fill during the construction of the Los Coyotes
Country Club. In addition, in September 1983, a soil cover was placed over the
Ramparts area sumps. As a result of these activities, the sumps at the McColl site are
covered by one to five feet of overburden. Previous studies by EPA and the State
characterized the wastes within the sumps to be comprised of four materials: char,
drilling mud, tar, and soil. The waste material occurs in two distinct layers; a layer
(See Attached Page)
17. Document Analyei8 a. Deacrlptora
Record of Decision - McColl, CA
Second Remedial Action
Contaminated Media: soil, debris
Key Contaminants: VOCs (benzene, toluene, xylenes), other organics (PAHs), metals
(arsenic, chromium, lead), other inorganics.
b. Identifiers/Open-Ended Terms
c. COSATI field/Group
18. Availability Statement 19. Security CIas8 (ThIs Report) 21. No. of Pag..
None 76
20. Security CIa88 (ThIs Page) 22. Price
None
(SH ANSI-Z39.18)
SH Instructions on Rev8fS&
OPTIONAL FORM 272 (4-77)
(Formerty NTIS-35)
Oepartment of Commerce
-------
EPA/ROD/R09-93/095
McColl, CA
Second Remedial Action
Abstract (Continued)
of soft material over a layer of hard material. The soft material is a combination of
soil, drilling mud, and tar, while the hard layer is mostly char, a coal-like material,
with pockets of tar. The interface between the soft and hard material 'occurs at various
depths in each of the sumps. Seeps of the tar waste have been observed in approximately
50 surface locations on seven of the sumps at the site, and this caused a health hazard
because upon exposure to the atmosphere, the tar emits gases, including benzene and sulfur
dioxide. In 1984, EPA issued a ROD to address the potential risks to human health and
environment posed by onsite soil. However, in 1985, the California Superior Court blocked
implementation of the remedy because the State agency failed to comply with State laws
which require submittal of an Environmental Impact Report prior to site remediation.
Since then, EPA has conducted two Supplemental Review of Alternatives (SROAs) for the
McColl site. These extensive studies included treatability studies to further assess the
effectiveness of the proposed remedial alternatives. Based on the results of the second
SROA, EPA selected the remedy presented in this ROD to address source contamination at the
Mc~oll site. A future ROD will address ground water contamination at the site as OU2.
The primary contaminants of concern affecting the soil and debris are VOCs, including
benzene, toluene, and xylenes; other organics( including PARs; metals, including arsenic,
chromium, and lead; and other inorganics.
The selected remedial action for this site includes excavating shallow metallic sprinkler
pipes in the Los Coyotes Area and decontaminating them onsite, with transportation offsite
for disposal; field characterization of each sump to determine the top of the char layer;
installing subsurface slurry walls around the Ramparts and Los Coyotes sumps; applying an
emission-suppressing foam over the waste sumps; treating approximately 55,280 yd3
soft-materials layer using in-situ solidification onsitei installing a RCRA-equivalent cap
over the solidified sumps, which will include a permanent gas collection and treatment
. system; grading the site to allow movement of waste away from homes and stabilizing
unstable slope areas; operating and maintaining the site, which will include installation
of ground water and vadose zone monitoring wells, ground water monitoring, and a gas
collection system; disposing of residuals generated during the remedial action offsite in
a permitted hazardous waste facility; providing for a contingent remedy of RCRA-equivalent
closure, including perpetual operation and maintenance of the site, if EPA determines that
use of solidification is not technically implementable; and implementing institutional
controls, including deed restrictions. The estimated present worth cost for this remedial
action is $78,620,000, which includes an estimated annual O&M cost of $828,000 for 30
years. The estimated present worth cost for the contingent remedy action is $36,722,000,
which includes an estimated annual O&M cost of $828,000 for 30 years.
PERFORMANCE STANDARDS OR GOALS:
Chemical-specific standards were not provided; however, the selected remedy will
potential carcinogenic risk and noncarcinogenic hazard levels to levels that are
considered acceptable by EPA, i.e., 10-6 and 0.03, respectively.
reduce
-------
. . VOLUME 1
RECORD OF DECISION
FOR THE
MCCOLL SUPERFUND SITE.
SOURCE OPERABLE UNIT"
FULLERTON, CALIFORNIA
June 1993
u.s. ENVIRONMENTAL PROTECTION AGENCY, REGION IX
75 HAWTHORNE STREET
SAN FRANCISCO, CALIFORNIA 94105
-------
Section
Part I.
Part II.
TABLE OF CONTENTS .
. Record of Decision for McColl Superfund Site
Fullenon, California
Declaration
1.0 Site Name and Location
2.0 Statemem of Basis and Purpose
3.0 Assessmem of Site
4.0 Description of Selected Remedy
4.1 Components of the Selected Remedy
4.2 Contingent Remedy
Statutory Determinations
5.0
. Decision Summary
1.0 Site "Name, Location and Description
2.0 Site History
3.0 Enforcemem History
4.0 Past Investigations and Cleanup Proposals
5.0 Highlights of Community Panicipation
6.0 Scope and Role of Operable Unit
7.0 Summary of Site Characteristics
8.0 Summary of Site Risks.
8.1 Toxicity Assessmem Information
8.1.1 Inhalation of VOC's
8.1.2 Inhalation of Fugitive Dusts
8.1.3 Ingestion of Comaminated Homegrown Vegetables
8.1.4 Ingestion of Contaminated Soil
8.1.5 Dermal Comact with Comaminated Soil
8.2 Risk Characterization
8.3 Environmental Risks
8.4 Determination Regarding Risk
Description of Altematives
9.1 Alternative # 1: No Action
9.2 Alternative # 2: RCRA Equivalem Closure
9.3 Alternative # 3: RCRA Equivalem Containmem
9.4 Alternative .# 4: Excavation and On-Site Rotary Kiln
Incineration
Alternative # 5: Fullin-Situ Solidification with a
RCRA Equivalem Cap .
Alternative # 6: Fullin-Situ Solidification with a
Clay Cap
Alternative # 7: Soft Material Solidification
Alternative # 8: Selective In Situ Solidification
with Waste Excavation
Alternative # 9: Selective In Situ Solidification
without Excavation
10.0 Nine Evaluation Criteria
10.1 Comparative Analysis of Alternatives
11.0 The .Selected Remedy
11.1. Goals of the Selected Remedy
9.0
9.5
9.6
9.7
9.8
9.9
Paae
i
i.
i
i
i
ii
iii
1
1
1
5
5
7
7
12
15
15
15
15
21
21
21
25
26
26
26
26
29
29
30
31
31
31
32
32
33
35
35
-------
12.0
13.0
Components of Selected Remedy
Depth of Treatment for Selected Remedy
Slutry Walls, Retaining Walls. and RCRA-Equivalent Cap
Residual Generation
Cost and Time
Risks and Hazards
One Sump Test: Performance Criteria for the Selected
Remedy .
11.8.1 Evaluation of Performance Criteria
11.9 Contingency Remedy
11.9.1 Cost and Time
11.10 End Use of the McColl Site
Statutory Determinations
12. 1 Protection of Human Health and the Environment
12.2 Compliance with Applicable or Relevant and. Appropriate
Requirements (ARARs)
12.3. Cost Effectiveness
12.4 Utilization of Permanent Solutions and Alternative
Treatment Technologies (or Resource Recovery
Technologies) to the Maximum Extent Practicable
12.5 Preference f~r Treatment as a Principal Element
Documentation of Significant Changes
11.2
11.3
11.4
11:5
11.6
11.7
11.8
VOLUME 1 APPENDICES
35
36
40
41
41
41
41
42.
43
43
43
44
44
44
44
45
45
45
-------
UST OF TABLES Paae
Table 1: Estimated McColl Sump Waste Material by Depth and Volume 9
Table 2: Concentrations of Selected Chemicals of Potential Concern 10
Table 3: Concentrations of Selected Inorganic Chemicals 11
Table 4: Characteristic Waste Types - Physical and Chemical Descriptions 13
Table 5: Chemicals of Potential Concern 14
Table 6: Matrix of Potential Exposure Routes Quantitatively Evaluated 16
Table 7: Summary of Complete ExpOsure Pathways Evaluated for Each Receptor 17
Table 8: Summary of Carcinogenic CDl's for the Potential Receptors for Inhalation of
vec's Exp!JSure PathwaY 18
Table 9: . Summary of NoncarcinogenicCDl's for the Potential Receptors for
Inhalation of vec's Exposure Pathway 18
Table 10: Summary of Carcinogenic CDl's for the Potential Receptors for Inhalation of
Fugitive Dust Exposure PathWay 19
Table 11: Summary of Noncarcinogenic CDl's for the Potential Receptors for
Inhalation of Fugitive DuSt Exposure Pathway 19
Table 12: Summary of Carcinogenic and Noncarcinogenic CDl's for the Potential
Receptors for Ingestion of Contaminated Homegrown Vegetation: Leafy
Crops 20
Table 13: Summary of Carcinogenic and Noncarcinogenic CDI's for the Potential
Receptors for Ingestion of Contaminated Homegrown Vegetation: Vine
Crops 20
Table 14: Summary of Carcinogenic CDl's for the Potential Receptors for Ingestion of
Contaminated Soil 22
Table 15: Summary of Noncarcinogenic CDrs For the Potential Receptors for
Ingestion of Contaminated Soil 22
Table 16: Summary of Carcinogenic CDI's for the Potential Receptors for Dermal
Contact with Contaminated Soil 23
Table 17: Summary of Noncarcinogenic CDl's for the Potential Receptors for Dermal
Contact With Contaminated Soil 23
Table 18: Summary Total Carcinogenic Risks Due to Multipathway Exposure 24
Table 19: Summary Total Noncarcinogenic Risks (Hazard Indices) Due to
Multipathway Exposure 24
Table 20: Alternatives Considered in the September 1992 Proposed Plan 20
Table 21: Nine Criteria"Level of Confidence Analysis 34
Table 22: Depth to Char Layer in the Sumps 39
-------
UST OF FIGURES
PaQe
Figure 1: Location of McColl Superfund Site 2
Figure 2: McColl Supe~nd Site Layout Map 3
Figure 3: . Location of Surface Seeps 4
Figure 4: Conceptualization of Typical Sump. 8
Figure 5: RCRA-Equivalent Cap 28
Figure .6: Slurry Walls Surrounding Sumps 37
Figure 7: Slope Stability Improvements 38
-------
Appendix A:
Appendix B:
Appendix C:
UST OF APPENDICES
Assumptions Used to Calculate Inhalation of VOC's
Levels of Confidence for Five Balancing Criteria
Tables of Applicable, Relevant, and Appropriate Requirements (ARAR's)
-------
ARAR
BPHE
CD I
CED
CEQA
CERCLA
CFR
DOl
DTSC
EIR
EPA
ESD
HI
NCP
OU.
PHERA
PRP
RCRA
RfC
RfD
RifFS
RME
ROD
SARA
SROA
TBC
UST OF ACRONYMS
Applicable or Relevant and Appropriate Requirement
Baseline Public Health Evaluation
Chronic Daily Intake
Campaign for Economic Democracy
California Environmental Quality Act
Comprehensive Environmental Response, Compensation, and Uability Act of 1980
Code of Federal Regulations
U.S. Department of Interior
California Department of Toxic Substances Control
Environmental Impact Repon
U.S. Environmental Protection Agency
Explanation of Significant Differences .
Hazard Index.
National Oil and Hazardous Substances Pollution Contingency Plan
Operable Units
Public Heatth Evaluation of Remedial Alternatives
Potentially Responsible Party
Resource Conservation and Recovery Act
Reference Concentration
Reference Dose
Remedial Jnvestigation/Feasibility Study
Reasonable Maximum Exposure
Record of Decision
Superfund Amendments and Reauthorization Act of 1986
Supplemental Reevaluation of Alternatives
To Be Considered
-------
PART I. DECLARATION
1.0 SITE NAME AND LOCATION
McColl Superfund Site
2650 Rosecrans Avenue
Fullerton, California 92633
2.0 STATEMENT OF BASIS AND PURPOSE
This Record of Decision (ROD) presents the selected remedial action for the McColl Superfund site in
Fullerton, California The ROD is presented in two volumes. Volume one contains the Declaration, the.
Decision Summary, and appendices. Volume two contains the Responsiveness Summary and
appendices. .
. This document was developed in accordance with the Comprehensive Environmental Response,
Compensation, and Uability. Act of 1980 (CERCLA) as amended by the Superfund Amendments and
Reauthorization Act of 1986 (SARA), 42 U.S.C. Section 9601 et sea., and, to the extent practicable, in
accordance with the National Oil and Hazardous Substances Pollution Contingency Plan, 40 C.F.R.
Section 300 et sea., ("NCP"). The administrative record index identifies the documents upon which the.
selection of the remedial action is based.
3.0 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 endangerment to
public health, welfare, or the environment.
4.0 DESCRiPTION OF THE SELECTED REMEDY
This ROD selects a remedy for the source soils operable unit, addressing the waste and the contaminated
surrounding soils. Groundwater issues will be addressed in a later operable unit ROD.
Based upon consideration of the requirements of CERCLA, the detailedanalysis of the alternatives using
the nine criteria, and public comments, EPA, after consultation with the California Department of Toxic
Substances Control (DTSC) , has determined that Soft Material Solidification is the most appropriate
remedy for the McColl Superfund Site. Due to technical uncertainties that cannot be resolved until field
implementation, EPA has included a contingency to the selected remedy. Therefore, EPA believes that
Soft Material Solidification with a contingency of RCRA-equivalent closure is the most appropriate remedy.
This remedy will treat the principal threats at the Site such as benzene, sulfur dioxide, and arsenic. It will
minimize the seeping material and will treat the acidic soft material by eliminating its corrosive
characteristic.
4.1 Comoonents of the Selected Remedy
The selected remedy will involve solidification of all soft material in each surri.p above the char/soft material .
interface. The remedy consists of the following components: .. ..
- Excavation and decontamination of shallow metallic sprinkler pipes in the Los Coyotes area, followed
by off-site transportation an~ disposal. .
i
-------
- Characterization of each sump using field methods such as cone penetrometers, correlated with
subsurface borings, to determine the top of the char layer in each sump.
- Installation of subsurface 'slurry cut-ott walls around the Upper Rampans sumps, and a separate slurry
cut-off wall around the Lower Ramparts and the Los Coyotes sumps (see Figure 6, Part II).
- Slope stability improvements are to be determined during design in unstable slope areas (see Figure
7, Part II).
- In:situ solidification of the soil, drilling mud, tar wastes, and contaminated soils above the char layer.
The proposed plan presented a conceptual approach of using two S...foot diameter augers for the
solidification. However, the final decision on the equipment size will be determined during design.
- The site will be graded (to contour the site, and to allow movement of waste away from homes) and a
. 'RCRA cover system, including a permanent gas collection and treatment system, will be placed over the
solidified sumps.
- Long-term operation and maintenance includes installation of groundwater and vadose monitoring wells,
monitoring of the groundwater, and a gas collection system.
- Site security and routine site maintenance.
In selecting Soft Material Solidification, EPA intends to treat by solidification all of the material in each
sump above the char/soft material interface. '
The project implementation cost for this alternative is $46,073,000 (1990 dollars). The annual operation
and maintenance costs are $828,000. The net present value (1994 dollars) for capital cost and operation
and maintenance cost for the 30 year design is $78,620,000. Implementation of this remedy is expected
to take approximately 4.7 years, of which approximately 2.8 years is utilized for actual in-situ solidification
activities.
4.2 ContinQent Remedv
Soft Material Solidification will be applied first to one sump. If EPA determines that Soft Material
Solidification is technically implementable, it will be implemented on the remaining 11 sumps. In deciding
whether Soft Material Solidification is technically implementable, EP A will consider at a minimum eight
performance criteria .
At the conclusion of the one sump test, EPA will consider whether the results of the one sump test, when
extrapolated to site-wide implementation, deviate excessively, both individually and collectively, trom the
expected results set forth in these eight criteriaEPA will evaluate the extent of deviation from these
criteria and determine if Soft Material Solidification continues to be the most appropriate remedy for the
site.
Although EPA is confident that Soft Material Soiidification will be successful at the McColl site, there is
inherent uncertainty whenever a remedy involves the implementation of a proven treatment technology
in an innovative manner. Therefore, EPA has decided to include RCRA-equivalent closure as a contingent
remedy in the event EPA determines that Soft Material Solidification is not technically implementable as .
discussed above. .
If RCRA-equivalent closure is chosen it would consist of the following: constructing a multilayer cap over
the untreated sumps with a 935 collection and treatment system to prevent infiltration of water and release
ii
-------
of hazardous air emissions; building subsurface slurry walls around the sumps to prevent migration of
water into the waste and outward migration of contaminants; stabilizing steep slopes on the site with
retaining walls; and conducting groundwater monitoring. Operation and maintenance will be necessary
in perpetuity at the site, wnich include site security and routine site maintenance.
The project implementation cost for the contingency remedy is $14,737,000 (1990 dollars). The annual
operation and maintenance costs are estimated at $828,000. The net present value (1994 dollars) for
capital cost and operation and maintenance cost for 30 year design is $36,722,000. Implementation of
this remedy is expected to take approximately 2.2 years, of which approximately 1.3 years is utilized for
actual field activities. .
5.0 STATUTORY DETERMINATIONS
The selected remedy, including the contingent remedy, is protective of human health and the environment,
complies with Federal and state requirements that are legally applicable or relevant and appropriate to
the remedial action, and is cost-effective. This remedy utilizes permanent solutions and alternative
treatment technologies to the maximum extent practicable and satisfies the statutory preference for
remedies that employ treatment that reduces toxicity, mobility, or volume as a principle element. Because
this remedy will result in hazardous substances remaining on-site above health-based levels, a review will
be conducted within fi\te years after commencement of remedial action to ensure that the remedy
continues to provide adequate protection of human health and the environment.
c. w ~
'.30,cr3
Date
iii
-------
PART II. DECISION SUMMARY
1.0 SITE NAME. LOCATION AND DESCRIPTION
The McColl Superfund site is a former refinery waste disposal site located in the City of Fullerton, Orange
County, California (see Figure 1). The site surface and former site development features divide the site
into three general areas. The Ramparts area is a terraced section, sloping toward the south, located In
the northeast portion of the site. The Los Coyotes area is southwest of the Ramparts area in the
southeast section of the site. The Ramparts and Los Coyotes areas contain waste disposal pits called
sumps. These areas are now covered with sparse grasses and other low-growing vegetation. The third
area, a staging and parking area located at the northwestern section of the site, was developed in .1983
in anticipation of waste exc~vation remediation activities. These areas are presented in Figure 2.
2.0 SITE HiSTORY
From 1942 through 1946, approximately 72,600 cubic yards of waste sludge was disposed of into the 12
Ramparts and Los Coyotes sumps at the McColl site. The Ramparts area contains six sumps, referred
to as sumps R-1 through R-6. The Los Coyotes area also contains six sumps, referred to as sumps L-1
through L-6. In an attempt to mitigate site odors during the 1950s and early 1960s, three sumps (R-1,
R-2, and R-4)in the Ramparts area were covered with drilling mud. Arsenic-containing waste of an
unknown date and origin was later disposed of into Ramparts sump R-1. Additional soil cover was placed
over the sumps in the Ramparts area in September 1983. The Los Coyotes sumps were covered with
natural fill materials during the construction of the Los Coyotes Country Club golf course in the late 19508.
As a result, all of the sumps at McColl are now covered by one to fIVe feet of overburden.
Previous remedial investigations completed by DTSC and EP A provided characterization of the types and
location of wastes at the McColl site. In general, the four types of material (char, tar, drilling mud, and
soiQ are contained within the sumps and occur as distinct types of waste that are somewhat segregated
by depth, although not as discrete strata. The largest waste fraction consists of a char waste material that
occurs mainly in the bottom layer of all sumps. The char has been described as a coal-like material in
various drilling logs. The upper portion of the sumps is comprised of soil or a combination of soil and
drilling mud. The tar is believed to be dispersed as pockets within the soil cover, drilling mud and char
mate.rial. However, the exact location and disposition of tar within the sumps is unknown. Because the
tar is soft and mobile, it appears at approximately 50 surface locations at the site as seeps (see Figure
3). .
3.0 ENFORCEMENT HISTORY
EPA has identified several potentially responsible parties (PRPs) for the McColl site. As discussed below,
EPA is currently in litigation with four national oil company PRPs (Shell Oil Company; Union Oil Company
of California; Atlantic Richfield Company; and Texaco, Inc.) and a site landowner PRP, McAuley LCX
Corporation. EPA has interacted with other PRPs from time to time, including Phillips Petroleum. Several
PRPs have been involved in the McColl site since the early 1980s, when they participated in site
investigatory work. Over the last several years, the four oil companies plus Phillips Petroleum have
referred to themselves collectively as the McColl Site Group.
Enforcemerit activities began in 1983 when EPA sent general notice letters to a group of PRPs including
several oil companies. In July 1984, after EPA issued a ROD selecting. an excavation and redisposaJ
remedy, EPA issued orders to several PRPs pursuant to CERCLA Section 106 directing implementation
of the remedy. The respondents named in the orders refused to comply and sued EPA in federal district
court. In early 1990, EPA issued special notice letters to the fIVe oil companies and the landowner
-------
0rmIp ec-r, LiIw ../"-.._1
-.._.._.._n_n_o._..._..-.--..-..-..-...-...-..-. -..-----..-...'
!
!
!
!
. _u_.._.~ !
!! !
i " ."'''-''-''---.
i . a-.."....
,,-..-...-.--..-...-..-. .-...-;
!
J
.-"....
N
.
I.
i
J
r
"
FULLERTON
. ....,.. To SooI8
Mol,. A.....
!
!
r'-"-,,-,,-,.]
! BUENA PARK
~
,.
~..... ....
FIGURE 1
Location 01 McColl Superfund Site
2
-------
ROSECRANS AVENUE
w
518910g Area
o
c
Q)
Q)
~
"n;
u.
o
"E
.g
"n;
u.
LEGEND
R.I Ramparb Sum~ Number
L-I Los Coyotes Sump Number
FIGURE 2
McColl Superfund Site - Layout Map
-------
r
N
Not to Scale
Ralph B. Clark
Regional Park
~
. Rosecrans Avenue
McCOLL SITE
. 0
. X~. ~ :"
L-4
(0 L-1 x
L-3 @x Xx
. Xx
L-2
~
"t:::
Q
t:
Q)
~
~
~
R- Ramparts Sumps
L- Los Coyotes Sumps
x Approximate Location
of See .
Los Coyotes Golf Course
FIGURE 3 Location o' Seeps
-------
McAuley, followed by Section 106 orders, relating to groundwater investigatory. work. These parties again
refused to comply with the orders.
In February 1991, the United States and the State of California filed suit in a federal district court against
Shell Oil Company, Union Oil Company of California; Atlantic Richfield Company; Texaco, Inc.; and
McAuley LCX Corporation pursuant to Section 107 of CERCLA. The governments are seeking to recover
all costs already incurred in connection with the site and are seeking a declaration that the defendants
are liable for the cleanup. The court has ruled that the landowner McAuley LCXCorporation is liable
under CERCLA for costs and for cleanup. EPA is seeking a similar early ruling against the oil company
defendants based on clear evidence that they arranged for the disposal of the waste at the site.
4.0 PAST INVESTIGATIONS AND CLEANUP PROPOSALS
In 1984, EPA signed a ROD selecting excavation and off-site disposal of the wastes at the McCOll site.
In 1985, a California State Superior Court enjoined the predecessor of DTSC from implementing the
excavation remedy, finding the state had failed to comply with the California Environmental Quality Act
(CEQA), withoUt performing an Environmental Impact Report (EIR).
Congress amended the Superfund law in 1986, and EPA undertook a reevaluation of remedial alternatives.
The reevaluation included extensive work on an excavation and thermal destruction alternative. In 19.89
EPA issued an updated feasibility study (the SROA), and a Proposed Plan identifying thermal destruction
. as the preferred remedy. EPA provided a public comment period on the Proposed Plan. In 1989 and
1990, EPA also conducted off-site thermal destruction tests and an on-site excavation demonstration.
Based on the information from the treatability studies and the public comments received, EPA decided
to re-evaluate the remedial alternatives. The result of this assessment was the SROA II. The SROA II re-
evaluated RCRA-equivalent closure, RCRA-equivalent containment, and thermal destruction from the 1989
SROA and evaluated several new alternatives involving full or partial solidification of waste materials,
including a proposal by the McColl Site Group.
In August 1992, EPA issued a Proposed Plan expressing its preference for the Soft Material Solidification
alternative with a contingency for RCRA-equivalent closure. A public comment period was held from
August 31 to September 29, 1992 on the SROA II and EPA's Proposed Plan. The McColl Site Group
requested and received an extension to the comment period until October 29, 1992. A public meeting
was held on September 17,1992 to answer questions and accept formal public comments. .
5.0 HIGHUGHTS OF COMMUNITY PARTICIPATION
The remedy selection process has fulfilled the public participation requirements of CERCLA Sections 113
and 117. Community members have been involved with the McColl site since the beginning of the
investigation. The site initially was brought to the attention of the regulatory agencies as a result of odor
and health complaints received from residents beginning in July 1978. Community concern increased
gradually through 1980. . The efforts of the Campaign for Economic Democracy (CED) , a statewide
consumer and environmental organization, and a speech given to residents by Louis Gibbs, president of
the Love Canal Homeowners Association, focused media attention on the site and heightened community
awareness about McColl. .
Due to the increasing community concerns, DTSC organized a public hearing in the fall of 1980. Peter
Weiner, the Governor's speciSl assistant on Toxic Substances Control, chaired the hearing. A panel of
state agency representatives also participated. Jane Fonda, of CED, spoke to the community residents
and the media following the hearing. .
5
-------
Individual memberS of the community continued to be involved in discussions and decisions related to
the site through 1984, when. EPA and DTSC announced that the site would be remediated using the
excavation and redisposaJ alternative. Community comments received at the first public hearing indicated
strong community support for this decision.
Following the state court injunction blocking the state from implementing the remedy, some community
members expressed increasing frustration at delays in the clean-up process. This frustration led to the
formation of the McColl Action Group. This neighborhood committee participated actively in decisions
related to the site from 1985 through 1991. EPA and DTSC often were invited to make presentations to
the group. The group disbanded in 1991. .
Another community group was formed in 1991, the Fullerton Hills Community Association. This group has
had input into site-related decisions since its formation.
Elected officials also have expressed interest in the site, most notably former Congressman William
Dannemeyer. . All elected officials in the area are on the mailing list for the site, and receive information
related to site activities. ..
Starting in 1986, EPA and DTSC have held regular meetings as part of the Interagency Committee. The
committee is comprised of the following agencies: U.S. Environmental Protection Agency, State of
. California Department of Toxic Substances Control, City of Fullerton, South Coast Air Quality Management
District, City of Buena Park, Orange County Environmental Health, and California Regional Water Quality
Control Board, California Department of Health Services' Drinking Water Branch, and California
Environmental Protection Agency's Office of Environmental Health Hazard Assessment. The elected
officials include the 39th Congressional District (formerly held by Representative Dannemeyer and
currently held by Representative Edward Royce).
Community participation has continued to be important in the decision-making process over the last
several years. During the pubHc comment period and public hearing to receive comments on the
proposed thermal destruction plan of February 1989, community members wrote more than 140 letters
and made more than 100 oral comments.
Far fewer comments were received from the public during the 1992 comment period compared to the
comment period on the proposed thermal destruction plan in 1989. The most recent public comments
indicate that community opinion on the Proposed Plan varied widely. Some commenters supported EPA's
proposed plan. Some residents continued supporting a total cleanup of McColl waste, and others
supported the McColl Site Group's proposal for selective treatment of the waste. In general, residents
are frustrated at a perceived lack of action at the site, and .are in favor of moving forward with any plan
they believe will minimize risk to the community. and can be implemented in a reasonable amount of time
at a reasonable cost. .
Throughout the remedial process, EPA and DTSC have continued to conduct a variety of community
relations activities. Activities have included frequent public meetings, small group meetings, regular
mailings to community members, a toll-free information line, an on-site open house, and. regular contact
with the media to provide info.rmation.
EPA.has taken community concerns into account in its decision making for the remedy. In order to avoid
future frustration caused by project delays, EPA has proposed a contingency of RCRA-equivalent closure
if the selected remedy (Soft Material Solidification) is not technically implementable. . The. use of a
contingency ROD will help avoid further delays in the cleanup. process by eliminating the need to select
another remedy if the selected remedy (Soft Material Solidification) cannot be fully implemented. EPA
believes the selected remedy protects human health and the environment. will be completed in a
6
-------
reasonable amount of time with low risk to the community, and is coSt effective.
EPA will continue to work. closely with DTSC and the community throughout the entire remediation
process to keep residents informed of progress at the site. EPA and DTSC will monitor community
interests and concerns, and will conduct community relations activities as needed to address those
concerns.
For more detailed information on community participation, see the McColl Community Relations Plan,
dated May 1992.
6.0 SCOPE AND ROLE OF OPERABLE UNIT
As with many Superfund sites, the problems at the McColl site are complex. As a result, EPA has.
organized the work into two operable units (OUs). These are:
- OU One: Waste and contaminated soil
- OU Two: Contamination in the groundwater
The first OU, the subject of this ROD, addresses the waste and contamination of the surrounding soils.
EPA is currently in the Remedial Investigation/Feasibility Study (RI/FS) stage of OU Two. The ROD
regarding OU Two is scheduled to be signed in October 1995.
7.0 SUMMARY OF SITE CHARACTERISTICS
As shown in Figure 2, there are 12 sumps containing waste at the site. The Ramparts area contains six
sumps and the Los Coyotes area contains six sumps. Table 1 shows the estimated sump depths and
volume of waste for each sump.
Figure 4 is a conceptual picture of a typical sump at the site, showing the soft material on the upper
portion of the sump, followed by the char layer and finally contaminated soil.
Tables 2 and 3 show the average concentrations for waste-only samples and for waste 'and contaminated
soil for selected organic and inorganic compounds of concern.
In general, the material contained within the sumps occurs as distinct tYpes of waste that are somewhat'
segregated by depth, although not as discrete strata. The largest waste fraction consists of a hard
organic waste material (char) that occurs mainly in the bottom layer of all sumps. The char has been
described as a coal-like material in various drilling logs. The upper portion of the sumps is cOl1:'lprised
of soil or a combination of soil and drilling mud. Tar wastes (tar) are also located in the sumps; however,
the location and disposition of tar within the sumps is unknown. The area between the surface and the
top of the continuous layer of char materiaJ has been designated by EPA as the 'soft materiaJ layer" of
the sumps.
Seeping of the tar waste has been observed in approximately 50 locations on seven of the sumps (see
Figure 3). .The tar waste is geotechnically unstable. It is acidic (pH cons.istently less than 2), contains
a high concentration of leachable sulfate, and has a total organic carbon content of t,lp to 61 percent. .
When exposed to the atmosphere, it emits gases including sulfur dioxide. benzene, and
tetrahydrothiophene (an organic sulfur compound). .
7
-------
SOFT MATERIAL
Q)
-~- r,,'
~---~ ,.... (," J
-y.' ~,
~ - C - - "-- I "'i-:
~~ ~~~
~-{"-- /_/.J{
~..:. --;- , '&jj' /"
",'" -.... '..... ,~
""5:.....:,,'... ~'-~~ J-
~ ~ ....- ... r (-
...... ,-";""....... "" " ~ ,..., r-
, t""'-'J :"-,,,,"----,-"-, .......~,-, -; "" ,---~~~-=. .J,jI---- /"1
- - -- ("" -- , .....) " '" -./'" , .,,""" - J -
-"., ...:- /. ,,).J.... '" :'I" -...... -'''....", ,. -:; ( , ~- -.,/
:\. - /~-;',L-"'J-;"'-'.J ,,~- ,..-,-'"""\. .-.-.-~ -" r~ r
CONTAMINATED SOIL
CHAR
FIGURE 4 Conceptualization .of Typical Sump
-------
TABLE 1
ESTIMATED McCOLL SUMP WASTE MATERIAL BY DEPTH AND VOLUME
.SUMP. ..DEPTHOF' CONTAMINATED WASTE VOLUME
MATERIAl . . '(cubic yards)
(feet)-
R-1 28 8,800
R-2 55 9,800
R-3 31 6,800
R-4 30 5,200
R-5 35 7,300
R-6 45 15,100
L-1 31 11,000
L-2 35 8,000
L-3 37 10,600
L-4 33 4,800
L-5 45 4,000
L-6 35 5,700
Total 97,100
9
-------
TABLE 2
CONCENTRATIONS OF SELECTED CHEMICALS OF POTENTIAL CONCERN
.. Chemical. ofConcem. . Waste~pecific Samples... All Samples
.. . Averag~.(I1g/kgHa). HAve rage (l1g/kg)
Chlorinated Aliphatic Hvdrocarbons
Methylene Chloriqe 15.814 5,233
Aromatic Hvdrocarbons
Benzene 226,428 53,755
Ethylbenzene 57,404 16,724
Toluene 166,179 41,310
Total Xylenes 102,676 31,283
Ketones
Acetone 36,333 11,876
2-BUtanone 7,384 5,568
Pthalate Esters
2-Methylnapthalene 99,031 43.158
Napthalene 143,313 68.815
Phenanthrene 58,550 19,076
bis(2-ethylhexyQ pthalate 52,050 16.266
Oraanic Sulfur Compounds (expressed as)
Tetrahydrothiophenes 198,923 70.720
Total Organic Compounds 1.164,085 383,784
-
Inoraanic Chemicals
Leachable Sulfate 192,718 41.821
pH ' 1.73 5.5
Note: Chemical concentrations and component classifications based on CH2M Hill Field Report. October 1987
(a) lLg/kg = ppb
10
-------
TABLE 3
CONCENTRATIONS OF SELECTED INORGANIC CHEMICALS
. ChemicaJ:ofConcem
All. Samples
(mg/kg){?)
Average
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper.
Lead
Manganese
Mercury
Nickel
Tin
Vanadium
Zinc
al mgtKg ppm
15.1
179.0
0.35
1.2
134.2
4.2
14.6
216.1
0.05
56.1
5.2
35.5
50.1
11
-------
Drilling mud covers wastes in Lower Ramparts sumps R-1, R-2, and R-4. The drilling mud is similar to a
soft clay with a high moisture content. It is chemically characterized bya neutral to slightly alkaline pH
(6-8), high leachable sulfate content, and a total organic carbon content of 34 percent.
The majority of char waste has been identified at the bottom layers of the sumps. Characteristics of this
waste are a hard black, coal-like texture and a fine granular consistency when crushed. It is acidic (pH
less than 2), contains elevated levels of organic and sulfur compounds, has a total organic carbon content
of 40 percent and releases, like the tar waste, sulfur dioxide and volatile organic compounds such' as
benzene when exposed to the atmosphere.
Arsenic-containing waste has been identified in a limited area within the upper one to fIVe feet of Ramparts
sump R-1. This zone represents the interface between the drilling mud and the soil cover. Arsenic
concentrations ranging from 40 to 5,000 mg/kg are found in the drilling mud and soil in this zone.
Contaminated on-site soils include the underlying soil material in contact with waste, the overburden, and
the mixed soil and waste. The mixed wastes can appear as black liquid or coal-like materials. white
powder, or dry black to brown powder within the soil matrix. Table 4 presents general physical and
chemical descriptions of the characteristic wastes at McColl. -
8.0 SUMMARY OF SITE RISKS
The baseline risk assessment provides the basis for taking action and indicates the exposure pathways
that need to be addressed by the remedial action. It serves as the baseline indicating what risks could
exist if no action were taken at the site. This section of the ROD reports the results of the baseline risk
assessment conducted for the site. .
The particular chemicals of concern identified in the risk assessment are listed in Table 5. The Baseline
Public Health Evaluation. dated May 1992, and the addendum dated July 1992, provides more detailed
information.
The exposure pathways of concern evaluated for potential health risks are: 1) inhalation of volatile organic
compounds (VOCs) emitted from the waste sumps, 2) inhalation of fugitive dust and inorganic compounds
generated by wind erosion, 3) incidental ingestion of contaminated soil, 4) ingestion of contaminated
garden vegetables, and 5) dermal contact with contaminated soil.
Below is a brief discussion of the health effects for primary chemicals of concern. For a complete
discussion of health effects related to all chemicals of concern see the Baseline Public Health Evaluation,
dated May 1992. and the addendum dated July 1992. .
Benzene and sulfur dioxide are the primary chemicals of concern. The possible toxic effects of benzene
in humans following exposure by inhalation include leukemia, central nervous system effects,
hematological effects, and immune system depression. Chronic exposure to benzene vapors can
produce reduced leukocyte, platelet, and red blood cell counts. Benzene is a known human carcinogen.
In humans, acute exposure to high concentrations of benzene vapors has been associated with dizziness,
nausea, vomiting, headache, d~wsinesst narcosis. coma, and death.
Sulfur dioxide is a colorless gas with a. strong odor, which is emitted from the combustion of sulfur-
containing fossil fuels, such as coal and oil, as well as many other sources. Sulfur dioxide is readily
absorbed upon contact with the. moist surfaces of the nose and upper respiratory passages.. Once
inhaled, sulfur dioxide is absorbed into the secretions lining the respiratory passages, then most of the
sulfur dioxide is then transferred into the systemic circulation. The majo~ toxic effects of sulfur dioxide
12
-------
TABLE 4
CHARACTERISTIC WASTE TYPES. PHYSICAL AND CHEMICAL DESCRIPTIONS
. . ',,:,""'" "' .::~ .. " : :Drllllng.": '.'.,:: . :,'ArSenlc . Contaminated
,pr~pe~::',:':: .. ". .'
Char .. .' .:,'., :'Tai':' "'. "Mud.. .. ".: 'Contalnln~' : SoIl
Appearance hard. coal-like black viscous-like soft clay with high not visually variable
appearance substance found moisture content distinct
within the soft
material layer and
the char layer
Characteristic high leachable high- leachable high leachable high arsenic Elevated total
Chemical sulfate content. sulfate content. sulfate content .organic carbon,
Constituents releases sulfur releases sulfur leachable sulfate
dioxide, benzene, dioxide, benzene, content and sulfur
tetrahydrothiophene tetrahydrothiophene dioxide levels
pH <2 <2 <7 Unknown variable
Cubic yards (BM) 49,370 10,160 13,070 2,000 22.500
Moisture conteml', 20.1 11.7 13.2 19 variable.
%
Sulfur conteml', % 4.5 10.6 0.8 0.8 variable
Total Organic 20.76 Not available 34% Not applicable variable
Carbon (waste sample (average for Sump R-
average) 2)
a . Sulfur content assumed to be the same as drilling mud
b. Source: SITE Trial Excavation Report, EPA. 1990
8M = bank measurement = in-place volume of waste in sumps
13.
-------
TABLE 5
CHEMICALS OF POTENTIAL CONCERN
....Vapoi'S .
Sulfur Dioxide
Methylene Chloride
Benzene
Ethylbenzene
Toluene
Xylenes
Acetone
2-Butanone
2-Methylnaphthalene
Naphthalene
Phenanthrene
Tetrahydrothiophenes
. .
'.AIR..
..FugitiveDusts
Arsenic
Bis(2-ethylhexyl)
phthalate
2-Methylnaphthalene
Naphthalene
Phenanthrene
14
SURFACE SOIL AND
. VEGETABLES
Arsenic
Bis(2-ethylhexyQ
phthalate
2-Methylnaphthalene
Naphthalene
Phenanthrene
-------
inhalation occur in'the respiratory tract. Other information shows increased airway resistance or other
bronchoconstrictive effects aSsociated with sulfur dioxide. For more detailed information on the toxic
effects of these and other, contaminants associated with this site, see the Public Health Evaluation of
Remedial Alternatives (PHERA), dated May 1992 and the addendum dated July 1992 and August 1992.
Arsenic, although not a primary chemical of concern, is a significant contaminant found at the McColl site.
Arsenic is a known human carcinogen. The acute effects of arsenic are gastrointestinal effects, hemolysis,
and neuropathy. Respiratory irritation may occur following contact with arsenic. The chronic effects can
produce toxic effects on both the peripheral and central nervous systems, keratosis, hyperpigmentation,
precancerous dermal lesions, and cardiovascular damage.
8.1 Toxicity Assessment Information
Evaluation of health risks from a chemical or mixture of chemicals is based on the concentration of the
chemical to which, an individual is exposed and on the duration and frequency of exposure. The chronic
daily intake (CDI) is the estimate of daily exposure to a, chemical resulting from all complete or potentially
complete exposure pathways to a receptor averaged over an extended period of time. Calculation of the
CDI considers the 'concentratian of the chemical at the exposure point, the exposure frequency, the
exposure duration, and the physical characteristics of the receptor. The total CDI for a potential receptor
is the sum of the CDls for each chemical of concern. For detailed calculations see the Baseline Public
, Health Evaluation, dated May 1992, and the addendum dated July 1992.
Table 6 shows a matrix of potential exposure routes quantitatively evaluated.
Table 7 shows a summary of complete exposure pathways evaluated for each receptor. (Child resident,
adult resident, and Country Club worker.)
The following describes the CDI factor for each chemical within each relevant exposure pathway for a
given population at risk and assumptions under which the CDI was calculated. The assumptions used
to calculate these numbers are located in Appendix A.
8.1.1 Inhalation of VOCs
Tables 8 and 9 show a summary of carcinogenic and noncarcinogenic CDls for th'e potential recepto~
for the inhalation of VOCs exposure pathway. '
8.1.2 Inhalation of FUQitive Dusts
Tables 10 and 11 show a summary of carcinogenic and noncarcinogenic CDls for the potential receptors
for inhalation of fugitive dust exposure pathway.
The assumptions us~d to calculate these numbers are the same as those used for inhalation of VOCs.
8.1.3 InQestion of Contaminated HomeQrown VeQetables
Tables 12 and 13 show ,a summary carcinogenic and noncarcinogenic' CD Is for the potential receptors
of contaminated homegrown vegetation.
The assumptions used to calculate these numbers are located in Appendix A. .
15
-------
TABLE 6
MATRIX OF POTENTIAL EXPOSURE ROUTES QUANTITATIVELY EVALUATED
ExPosureM~diunil... ...Residential .. CommerciaV . Recreational..'
1<: . . ExposureRQute .... .. . populatior Industrial Population ...
I....,.. .. .".:..... ...... . Population .
Air
Inhalation of Vapors
Onsite C, VA, A - VA, A
Offsite C, YA,A W YA,.A
Inhalation of Fugitive Dusts
Onsite C, YA,A. - YA,A
Offsite C, YA,A W YA,A
Soil
Incidental Ingestion
Onsite C, YA,A - e,YA
Offsite C, YA,A W e. YA, A
Dermal Contact
Onsite C, YA,A - e, VA, A
Offsite C, YA,A W e. YA,A
Food
Ingestion of Vegetables C,A - e,A
C = child (1 - 6 years)
YA = young adult (7 - 18 years)
A = adult
. W = country club worker
- = not applicable
16
-------
TABLE 7
SUMMARY OF COMPLETE EXPOSURE PATHWAYS EVALUATED FOR EACH RECEPTOR
. . Exposure .Path\Nay ... Child Adult . Country
.. Resident .Resident Club
, . Worker
, 7-:18..:, .19&.
. . ..
...,. . .older. .
OFFSITE
Inhalation of VOCs X X X X
Inhalation of Fugitive Dust X .X X X
Incidental Ingestion of Soil X X X X
Dermal Contact with Soil X X X X
Ingestion of Vegetables X X' X'
ONSITE
Inhalation of VOCs X X
Inhalation of Fugitive Dust X X
Incidental Ingestion of Soil X
Dermal Contact with Soil X X
X = Complete Pathway
1. Ingestion of vegetables by adult residents was assessed as one receptor for 24 years as
an adult.
17
-------
TABLE 8
CARCINOGENIC CDIS
, .
. pReceptor .:Average .Case RMECase
...
..Chemical.'.. .. . LoweSt ,. Chemical. Highest;p .. Chemical Lowest Chemical Highest
. .C[)t.P ..:.CDI '"., CDI CDI
. (mgikg.; : (."g/kSt .:"..'.',.. . (mglkg. (mglkg-
Pday) P day) ., ...,..: day) day)
Child Methylene 7.Ox10-6 Benzene 5.9x1 0.5 Methylene 1.9x10'5 Benzene 1.5x1 O~
Residents Chloride Chloride
Young Adult Methylene 2.2x1 0-6 Benzene 1.9x10-5 Methylene 1.6x1 0-5 Benzene 1.3x1 O~
Residents Chloride Chloride
Adult Methylene 1.7x10-6 Benzene 1.4x10.5 Methylene 1.5x10.5 Benzene 1.2x1 O~
Residents Chloride Chloride
Young Adult Methylene 7.1x10-6 Benzene 5.7x10-5 Methylene 5.7x1 0-5 Benzene 4.6x1 0-4
Recr~ationist Chloride Chloride
Adult . Methylene 1.2x10-6 Benzene 9.6x10-6 Methylene 1.5x10.5 Benzene 1.2x1 O~
Recreationist Chloride Chloride
Country Club. Methylene 1.3x10.7 Benzene 1.1x10-6 Methylene 4.7x10.7 Benzene 3.8x1 0-6
Worker Chloride Chloride
TABLE 9
NONCARCINOGENIC CDiS
/ ..,..... ..
,-:Receptor. Avenlge Case RMECase
.',''''. .: ..,
ChemiC81' ..., LOwest . Chemical.:. Highest :" . Chemic8l:' .'Lowest'. Chemical. . Highest
CDI CDI .. .CDI. CDI
. (in.gikg- (mg/k~ .. (mg/~g- (mQlkg-
.. day) day). pday) day)
Child Phenanthrene 3.0x10-9 TICs . 1.Ox1 0-3 Phenanthrene 8.5x10.9 TICs 2.7x10-3
Residents -
Young Adult Phenanthrene 1.4x10-9 TICs 4.8x10-4 Phenanthrene 3.7x10-9 TICs 1.1x10-3
Residents
Adult Phenanthrene 8.5x10.1o TICs 2.9x1 O~ Phenanthrene 2.2x1 0-9 TICs 7.Ox10-4
Residents
Young Adult Phenanthrene 4.3x1 0-6 TICs 1.4x10-3 Phenanthrene 1.3x1 0-6 TICs 4.Ox10-3
Recreationist
Adult Phenanthrene 5.7x10.1o TICs 1 .9x1 0-4 Phenanthrene 2.3x10-9 TICs 7.1 x1 0-4
Recreationist
Country Phenanthrene 2.6x10.11 TICs 9.Ox10-9 Phenanthrene 5.2x10'11 TICs 1.6x10.5
Club Worker
TICS - Tentatively Identified Compounds
Ethylbenzene was evaluated as a separate chemical of potential concern and was selected to represent all non-thiophene based
tentatively identified compounds.
18
-------
TABLE 10
CARCINOGENIC eels
"Receptor Average Case ' uRMECase
" " "Chemical , , HigheSi: : LoWest '
" ,Chemicai' ',LoWest ' 'Chemical Chemical Highest '
CDI, .,' ,'CDI" CDJ CDI
(mgJk~ " (mg/kg:; '. (mg/kg- (mg/kg-
" ,day): day) day) day)
Child BEHP 2. 7x1 0.11 Arsenic 6.4x10-ll BEHP 7.7x10.11 Arsenic 2. 7x1 0-3
Residents '
Young Adult BEHP 8.4x10.12 Arsenic 2.0x10-ll BEHP 6.7x10:11 Arsenic 2.1x10"
Residents
Adult BEHP 6.4x10.12 Arsenic 1 .5x1 0-8 BEHP 6.1x10.11 Arsenic 1.9x1 0"
Residents '
Young Adult BEHP 9.6x1 0.12 Arsenic 2.3x1 0" BEHP 8.5x10.11 Arsenic 2.6x1 0"
Recreationist
Adult BEHP 1.6x10.12 Arsenic 3.9x1 0.10 BEHP 2.2x10.11 Arsenic 7.Ox10-9
Recreationist
, Country BEHP 5.Ox10.13 Arsenic 1.2x10.1o BEHP 1.9x10.12 Arsenic 6.Ox10.1o
Club Worker
TABLE 11
NONCARCINOGENIC CDIS
'Receptor': 'AverageCase ....1'.""'. 'RMECase
Chemical ': Lowest Chemical' uHighest ' , Chemical lowl!,st ' 'Chemical Highest' :'
u CDI CDlu,,": ,CDI CDI ,"
: (mgJkg" ': (rng/kg- ',. I', (rnQ!kg- : (mg/kg- : '
,,'}f~r""'" 'day} I ' . ,'day) ,': day)
, 1,'- , "'
Child Phenanthrene 3.Ox10.10 Arsenic 7.5x10" BEHP - 9.Ox10.1o Arsenic 2.8x1 0.7
Residents
Young Adult Phenanthrene 1.4~10'10 Arsenic 3.6x1 0" BEHP 3.9x1 0.10 Arsenic 1.2x10.7
Residents
Adult Phenanthrene 8.5x1 0.11 Arsenic 2.1 x1 0-8 BEHP 2.4x10.10 Arsenic 7.4x10"
Residents
Young Adult Phenanthrene 1.6x10.1o Arsenic 4.Ox10-8 BEHP 5.Ox10.1o Arsenic 1.6x10.7
Recreationist
Adult Phenanthrene 2.1x10.11 Arsenic 5.3x1 0-8 BEHP 8.8x1 0.11 Arsenic 2.8x10"
Recreationist
Country Club Phenanthrene 2.7x10.12 Arsenic 6.9x10.1o BEHP 5.~x10.12 Arsenic 1.7x10-9
Worker,
BEHP = bis(2-ethylhexyl)phthalate
19
-------
TABLE 12 .
LEAFY CROPS
CARCINOGENIC CD IS
.:Receptor Average Case RME Case
, .
ChemicaL ': LoWest, . Chemical . Highest ,Chemical Lowest Chemical Highest
,COI COI: COI COI
.. (mgfkjf. (mg/kg- (rng/kg-.. (mg/kg-
"day)' day) : daY) day)
Child BEHP 3.1x10"o Arsenic 7.5x1 0.7 BEHP . 9.4x10"o Arsenic 2.9xfO.7
Residents
Adult BEHP 1.1x10"o Arsenic 2.6x10.e BEHP 1.1x10-8 Arsenic 3.5x1 0.7
Residents
Child BEHP 6.7x10'" Arsenic 1.6x10.e BEHP
Residents
Adult BEHP 2.3x1 0'" Arsenic 5.5x1 0-8 BEHP
Residents
:. ReCeptor '"
'.:,:>', " ::..
"' . .
Chemicai.',..
,.,
",'" :
Child
Residents
."''','
.... ...
Phenanthrene
Adult
Residents
Phenanthrene
Receptor' ':
, ,
, Chemic:al
ReCeptor;
.... .....
:phemiCal
:',':.,. ..
c.' '
Child
Residents
Phenanthrene
Adult
Residents
Phenanthrene
BEHP = bis(2-ethylhexy~phthalate
NONCARCINOGENIC CDIS
../Average:Case(
,.
RMEease.
'.
P'" ..
P. . ... .
'.' 'lOWest' '. .
':':"cpCi
: (rri~!t
"d.ay)
3.5x10-8
".. "","',",",',',"'. . .... ..
.. . "". ... .. .
Highe.t:CfiemicaJ
,CPI;\
,'" (mg/k~:',:,.
day)" ::
8.8x1 0.7
Arsenic
..
Lowest
'.;COI.,',.,:."
(ing/kg-
day); ,
1.1 x1 0-8
. ...' ..
Chemica. :
. Chemical
: Highea1
CD!
.' (mg/kg.
day)
3.5x10.e
BEHP
Arsenic
7.9x10"O
2.Ox10'7
2.5x10-8
Arsenic
7.9x1 0.7
BEHP
Arsenic
TABLE 13
VINE CROPS
CARCINOGENIC CDIS
.. . ..
,:: Average Case ,
HIgheSt
COI
(mg/kg-
day)
. 6.3x1 0-8
RME~.
"Lowest .'.
':CDI:',
(mg/k~
day) ,',
,CheinitaJ " '
LOWeSt
'COI'. '
(mg/k~ ",
'day) .
2:Ox10.10
: Chemical
Arsenic
2.4x10"O
Arsenic
7.5x1 0-8
NONCARCINOGENIC CD IS
: ... .. " ,,,,":'.':..,:;
::Ave~geCase,. RMEC8se ,',
..
LOwest, Chemical Highest' . : ChemicaL Lowest Chemical Highest
CDr COLi " 0" " :,COI/" ,COI
,:(11'19/1<9-, ,(mg/kg. (,,;g/kg. (ing/l
-------
8.1.4 InQestion of Contaminated Soil
Tables 14 and 15 show the summary of carcinogenic and noncarcinogenic CDls for the potential
receptors for ingestion of contaminated soil.
The assumptions used to calculate these numbers are essentially the same as those used to calculate
the ingestion of contaminated homegrown vegetables. .
8.1.5 Dermal Contact with Contaminated Soil
Tables 16 and 17 show the summary of carcinogenic and noncarcinogenic CDls.for the potential
receptors for dermal contact with contaminated soil.
The residential and recreation receptors may also be exposed to chemicals via direct .soil contact with the
skin. As with other exposure pathways, exposure to soil contaminants via dermal contact is a function
of exposure frequency and exposure duration. However, dermal absorption of chemicals is also a function
of the amount of exposed body surface area. The exposure factors for the dermar pathways are the same
as those described above for the inhalation pathways. Exposure .to soil via dermal contact is also a
function of several parameters unique to this pathway. They include the amount of skin exposed to soil,
the amount of soil adhered to skin, and the proportional absorption of chemicals through the skin.
The assumptions use.d to calculate these numbers are located in Appendix A.
8.2 Risk Characterization
Potential carcino~enic risks at Superfund sites are generally evaluated by EPA in relation to an acceptable
risk range of 10 to 10-6 established in the National Contingency Plan. Risks below this range are
considered acceptable. Risks above this range are considered unacceptable and remediation is usually
required. Within the risk range (10-4 to 10-; the Agency has the discretion to take action depending on
site specific conditions.
A summary of total carcinogenic risks due to multi pathway exposure is shown in Table 18. The risks range
from 3x10.;s to 5X10-4. . .
Noncarcinogenic risks are described as a Hazard Index (HI), a unitless -value. The HI is a measure of the
potential for cumulative noncarcinogenic health effects and is the ratio of the exposure concentration or
. dose to the reference concentration (RfC) or reference dose (RfD). An HI greater than 1.0 indicates that
there is a potential for a noncarcinogenic health effect to occur as a result of exposure to chemicals
released from the site.. .
A summary of total noncarcinogenic risks due to multipathway exposure is shown in Table 19. The HI
numbers range from less than 0.1 to 1.8. .
There are certain aspects of the risk assessment that have likely resulted in an underestimation of
potential risks for the McColl site. Airborne chemical concentrations resulting from sulfur dioxide and
VOCs from the McColl site were estimated without consideration of the probable contribution.of emissions
from active seeps. The potential impact of seep emissions could not be evaluated quantitatively because
of insufficient data on the chemical composition -of the seeps and uncertainty related to the size and
number of seeps that would occur at the site under baseline conditions. Therefore, potential risks and
hazards associated with inhalation of sulfur dioxide and VOCs are likely ~o be underestimated.
21
-------
TABLE 14
CARCINOGENIC CDIS
,'Receptor " ' , Average 'Case RME Case
" Chemic8J, ,LoweSt:, 'Chemical Highest Chemical Lowest Chemical Highest
" CDI , ,"'.-CDt":,,',, CDI CDI
,(mg/kg.;, (mg/kg" ,(mgJkg- (mg/kg-
,day).' day) " , day) day)
Child BEHP 1.8x10-9 Arsenic 4.2x1 0.7 BEHP :U~1 ~-9 Ars,enic 1.1x1o.-6
Residents - .'
Young Adult BEHP 1.1x10.10 Arsenic 2.7x10-6 BEHP 6.4x10.10 Arsenic 2.Ox10.7
Residents
BEHP 1.7x10.1o Arsenic 42x10-a- ' BEHP' 1.2x10-9 " Arsenic 3.7x10.7
Adult
Residents
Young Adult BEHP 9.2x1 0-6 Arsenic 2.2x1 0.5 BEHP' 5.7x10.7 Arsenic 1.6x1 O~
Recreationist
Adult BEHP NA Arsenic NA BEHP, NA Arsenic NA
Recreationist
Country Club BEHP 4.4x10.12 Arsenic 1.1x10-9 BEHP 1.7x10'11 Arsenic 5.2x1 0-9
Worker
it:/'11" - DIS(z-etnYlneXYI)pntnaJate
TABLE 15
NONCARCINOGENIC CDIS
,Receptor
.",' AverageC8II8 '"
RME Case
Chemical
..,
ChemicaL
"'"
'<
Lowest '
CDI..
(riiglk~ ".
"day)"'"
2.0x1 0-6
"
Hi~6;,themiCaJ "
< (fT)9I~g;; ..,',;,',{) " """"" ",,',' , ' ,.,"".,..:,
'...day):<'" I',"""" ",," '
.' Chemical,
Highest
CDI
(ing/kg- ,
',day)-",
1.3x1 0'5
Child
, Residents
Phenanthrene
Arsenic
5.1x10-6
LoweSt
" ,
...,CDI.,
(m9lklf
, .';daYf
4.1x10-6
Arsenic
BEHP -
Young Adult Phenanthrene 1.8x1 0-9 Arsenic 4.7x10.7 BEHP, 3.7x10'9 Arsenic 1.2X10-6
Residents
Adult Phenanthrene 2.3x10-9 Arsenic 5.9x1 0.7 BEHP 4.7x10-9 Arsenic 1.5x10-9
Residents
Young Adult Phenanthrene 1.5x1 0-6 Arsenic 3.8x1 O~ BEHP 3.1 x1 0-6 Arsenic 9.6x10~
Recreationist
Adult Phenanthrene NA Arsenic NA BEHP NA 'Arsenic NA
Recreationist
Country Club Phenanthrene 2.4x10.11 Arsenic 6.Ox10-9 BEHP '4.8x1 0.11 Arsenic 1.5x10-9
Worker
BEHp. bis(2-ethylhexyQ phthalate
22
-------
TABLE 16
CARCINOGENIC CDIS
,. .
::.,R8ceptor .... ...... .
.. CJ:lemicai:
....:.... .}
..
Child
Residents
Young Adult
Residents
Adult
Residents
Young Adult
Recreationist
Adult
Recreationist
. Country
Club Worker
Receptor. .
':':':....
.,...,
Child
Residents
Young Adult
Residents
Adult
Residents
Young Adult
Recreatiorlist
Adult
Recreationist
Country
Club Worker
.,Aver.age c::ase::.
..
..
..
.'.RME. Case .
...
.:' LoWeSt' ,:'
.....CDI.).
...(m~g.
.:.day):::::.
1.8x10.'o
.. ..
.. .. .
:~i,!~~"
... ..
.: Lowest:
CD'.
.:(mglkg.' ,
. day):...
. .
,. Cnemical"::.
..
..
..
....:. :.
BEHP
Arsenic
1.1X10<8
BEHP
5.5x10." Arsenic 3.3x1 0-8
1.7x10"o Arsenic 4.2x10-9
4.5x10<8 Arsenic 2.7ic10<8
5.6x1 0-9 Arsenic 3.4x10-9
BEHP
BEHP
BEHP
BEHP
8.7x10.,2
Arsenic
2.1x10.'0
BEHP
8.7x10,'0
Chemical
Highest
CDI
(mg/kg- ..
day)
6.8x1 0-6
Arsenic
BEHP 8.OX10,'0 Arsenic 6.2x1 0-6
BEHP 3.OX10-6 Arsenic 9.3x1 0-6
BEHP 6.5x10'7 Arsenic 5.Ox10-5
BEHP 9.8x1 0.7 Arsenic 7,7x10-5
BEHP 8.8x1 0'" Arsenic 2.7x1 0-6
TABLE 17
NONCARCINOGENIC CDIS
.: ...:' .:, .::....;,AV~rI1~!~:"'"
..
BEHP = bis(2-ethylheXYOphthaiate
23.
..... .
. . . .
. . . ... . .
\::R~ECase :.
;..'.Chemical
., Highest::
..CDr"i
(mg/k~:
.. ,day).i,:'.'
1 .3x10-6
....
. . .. .. ,. .
t~
"..CDI:'
(!fI9fI!1f."
...day).....
1.0x1 0<8
-
4.6x1 0-6
Naphthalene
Naphthalene
5.8x10.7
, .. . ... .. '" ... .... ... ..
.. .. . . . ..
",", ',,",.. ',' .. .
Ctiemicai. ... . .
L.c:iWeSt,. Chemic81 :Hi9tieSt pl'ie;ni~:: ..
",:CDI . /:CDI ....
.cmg/k~. ...(....: }(mg/kSf
.day).,.. ..'.....day)::."
BEHP 2.1 x1 0-9 Naphthalene 2.1x10.7 BEHP
BEHP 9.9x1 0.10 Naphthalene 9.6xt 0-6 BEHP
BEHP 9.9x1 0.10 Naphthalene 9.6x1 0-6 BEHP
BEHP 7.8x1 0.7 Naphthalene 7.6x10's BEHP
BEHP 7.8x10.7 Naphthalene 7.6x10's BEHP
BEHP 2.Ox10.11 Naphthalene 1.9x1 0-9 BEHP
4.6x1 0-6 Naphthalene 5.8x1 0.7
3.9x1 0-6 Naphthalene 4.9x1 0-4
3.9x1 0-6 Naphthalene 4.9x1 0-4
9.4x10." Naphthalene 1.2x1 0-6
-------
TABLE 18
SUMMARY TOTAL CARCINOGENIC RISKS DUE TO MULTIPATHWAY EXPOSURE
" .,'. H
'.
. . Ingestion of .
.Homegrown
Vegetables
. . .Incidental .
. :lflgestionofSoil .:
Dermal Contact with .
Soil
Total
Receptors
'Inhalation ofV0C8 ;'Inhalation of.
.' '.. , . .' ,'.: ",.. '.. . FugitiveDu:m
Child
Residents
.'AVE..
2x10~
: ,'RME.','.:': ,.:AVE
RME,
AVE
5x10~
1X10.7
4X10.7
3x10.7
'RME."
6x10.7
AVE,
RME.,
7X10.7
2x1 O~
. ,AVE
2x1 O~
RME
AVE
RME
1x10.7
3x1 O~
8x10~
Adult
Residents
3x10~
2x10-5
9x1 O~
1x10~
5x10~
7X10.7
4x10.5
3x104
1X10.5
2x104
5x10.5
5X104
Country
Club
Worker
3x10~
1x10.7
2x10-8
9x10-8
NA
NA
2x10-8
9x1 0-8
4X10'\O
5x10-8
3x10~
1x10.7
TABLE 19
SUMMARY TOTAL NONCARCINOGENIC RISKS (HAZARD INDICES) DUE TO MUL TIPATHWA Y EXPOSURE
H " .
, . ...
'JnhaJation . . . .
,Recepto~ ofVOCs .Inhaliltioriof" IngeStion of .' ,'Iricid.,ntailngestioii. "Dermal:Contact with Total
Ir,.,., '
" H) H Fugitive', :00 Homegrown H' .'.'ofS6i1.'" '.' Soil
, '.DustS Vegetables '
H
HAVE RME' ,AVE .RME AVE 'RME AVE RME AVE RME AVE RME
Child 0.004 0.01 - - 0.001 0.004 0.005 0.01 0.002 0.001 0.01 0.02
Residents
Adult 0.01 0.03 - - 0.0003 0.001 0.4 1.0 0.1 0.8 0.5 1.8
Residents -
Country 0.00004 0.00007 - - NA NA 0.000006 0.00002 0.000002 0.00001 0.QOOO5 0.0001
Club
Worker
AVE = Average-case Exposure Scenario
RME = Reasonable Maximum Exposure Scenario
NA = Not Applicable .
- = Could not be calculated due to lack of inhalation toxicity values (i.e.. inhalation Rfcs)
Child exposure duration = 6 years '
Adult exposure duration = 24 years
HI for benzene and sulfur dioxide could not' be calculated
24
-------
The potential noncarcinogenic effects of inhalation of fugitive dusts could not be evaluated quantitatively
because of the lack of toxicity criteria for inhalation exposure to the chemicals of potential concern in
surface soil.
Exposure to surface contamination, including exposure to the waste, is likely to be underestimated for the
following reasons: 1) exposure to seeps via dermal contact and/or incidental ingestion could not be
evaluated quantitatively, and 2) the surface soil database is limited and may not represent the entire site.
Potential exposure to surface water runoff could not be evaluated quantitatively because surface runoff
data representing current site conditions were not available.
Also, there are no EPA verified RfDs for sulfur dioxide and benzene. Therefore, EPA was not able to
estimate non-carcinogenic risks for these compounds. However, if EPA verified RfCs are' developed prior
to implementation, their impact to human health will be evaluated during design.
EPA has made the following conclusions taking into account the uncertainties listed above:
-Of the chemicals initially identified as being of potential concern, three were identified as being
associated with potential risks: arsenic, sulfur dioxide, and benzene. .
-The average and RME total site carcinogenic risk estimates for all receptors, which range between 3x1 0-8
and 5x10-4, are below or within the acceptable risk range.
-The potential carcinogenic risks to residents living adjacent to the McColl site as a result of inhalation of
organic vapors, ranging between 2 x 10-6 and 2 x 10-5, are within the acceptable risk range. The
concentrations of VOCs at the fenceline locations were based on fate and transport modeling without
consideration of the contribution of active seeps.
-For exposure to noncarcinogenic chemicals other than sulfur dioxide, the estimated total site
noncarcinogenic His for the child resident and adult Country Club worker were less than 1.0.
-The estimated average total site noncarcinogenic His for exposure to chemicals other than sulfur dioxide
for the adult resident was below 1.0, and the RME HI was above 1.0. The elevated HI for the RME case
is associated with the dermal contact and incidental ingeStion of on-site surface soil pathways.
-Potential risks associated with inhalation of sulfur dioxide could not be assessed quantitatively because
of the lack of EP A-verified health criteria The estimated concentrations of sulfur dioxide on-site and at
nearby receptor locations resulting from the site were compared to concentrations known to produce
adverse effects in humans. The estimated concentrations on-site and at the fenceline receptor location
were greater than those known to produce adverse effects in humans, indicating that toxic effects to the
respiratory system$ of people recreating on-site or living adjacent to the site could result from sulfur
dioxide inhalation.
8.3 Environmental Risks
The Department of the Interior (DOl) prepared a preliminary natural resources survey in 1990, to determine
whether any' natural resources under the 001 trusteeship would be affected by hazardous substance
releases at this site. The conclusions of this survey indicate that wildlife exposure to contaminants. from
the pits is minimal, and it 'would be hard to demonstrate if wildlife were contaminated or impacted by
wastes prior to capping. It was also determined that a damage assessment to quantify injuries and
damages to resources held in trust by the 001 is not needed.
25
-------
8.4 Determination ReQardinQ Risk.
Based on the results of th~ BPHE and the conclusions summarized in this section, EPA has determined
that 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
endangerment to public health, welfare, or the environment. . .
9.0 DESCRIPTION OF ALTERNATIVES
A detailed evaluation of the alternatives for treatment of waste and soils IS presented in the SROA II, dated
April 1992. Alternatives selected for discussion in the September 1992 Proposed Plan are listed below
(see Table 20).
Risk evaluations (see the Public Health Evaluation of Remedial Alternatives, dated Mat 1992, and the
addendum dated. July 1992 and August 1992) were performed on all of the following alternatives,
excluding No Action, Full in-situ Solidification With A Clay Cap, and Selective in-situ Solidification With
Waste Excavation. . .
9.1 Alternative # 1: No Action
. EPA is required to develop and evaluate the No Action Alternative. The No Action Alternative serves as
the basis for the Baseline Public Health Evaluation (BPHE). This alternative assumes that no action would
occur at the site, which would allow unrestricted access to hazardous wastes and contaminated soils.
9.2 Alternative #2: RCRA EQuivalent Closure
Major Components of the Remedial Alternative
The major feature of this alternative is remediation of the site according to RCRA-equivalent closure
requirements for a landfill or surface impoundments with waste left in place. This alternative would have
provides for in-situ waste containment with perimeter soil-bentonite cutoff walls, a multilayer low-
permeability RCRA-Equivalent cap, and long-term groundwater and vadose zone monitoring.
Cover System Components
,
A multilayer cap would control air emissions escaping from the sumps and limit infiltration of surface
waters and precipitation into the wastes: Gases emitted by the wastes would be collected and sent to
a scrubber and granular activated carbon gas treatment system to control sulfur dioxide and organic
compound emissions. Each of these systems would be designed, constructed, and operated to conform
to current State of California and Federal RCRA requirements governing hazardous waste landfills. The
proposed multi-layer cap design of this alternative would consist of a foundation layer, a gas collection
layer, a compacted soil barrier layer, and a vegetation layer (see Figure 5). Slope stabilization, final
grading, and recontouring of the site would be performed.
Time and Cost Components"
The estimated time to implement this remedy is 2.2 years, with actual field work taking 1.3 years. The
estimated capital (1990), oper.ation and maintenance (yearly), "and total present worth (1994) costs are
$14,737,000, $828,000, and $36,722,000, respectively.
26
-------
TABLE 20
AL-T #1: NO ACTION . ALT #2: RCRA CLOSURE ALT #3: RCRA CONTAINMENT
. No. EPA Involvement . Subsurface cut-off walls . Slope stability Improvements and
. No Fence . Slope stability Improvements and retaining walls
. No Guard retaining walls . Construction of RCRA.equlvllent
. No Maintenance . RCRA-equlvalent cap on-slte landfill
. Gas collection and treatment system . excavation of wastes In sumps
. Groundwater and vadose zone using enclosures
monitoring wells . Placement of waste In landfill.
. Long term O&M of gas collection . Installation of RCRA-equlvalent cap
system and cap . G.. collection and treatment system
. Umlted guard and fence . Groundwater and vadose zone
monitoring wells
. Long-term O&M of g.. collection
system and illndfill
. Umlted guard and fence
ALT #4: ON-SITE ROTARY KILN ALT #5: FULL IN SITU SOLIDIFICATION ALT #6: FULL IN SITU SOUDIFICATION
INCINERATION WITH RCRA COVER WITH CLAY COVER
. excavation of arsenic and off-slte . Slope stability Improvements an~ . Slope stability Improvements and
treatment and disposal. retaining walls retaining walls
. exCavation of all wastes using an . Full In situ solidification of all waste . Full In situ solidification of all waste
enclosure and cover material, Including the and .cover material, Including the
. On-slte treatment of waste In a rotary arsenic In Sump R-1 arsenic In Sump fi..1
kiln Incinerator . Capture and treatment of emissions . Capture and treatment of emissions
. Flue gas treatment to meet SCAQMD from the solidification process from the solidification process
regulations . Grading of solidified material . Grading of solidified material
. Final grading and aesthetic . Installation of RCRA-equlvalent cap . Installation of clay cap
Improvements to the site . Gas collection and treatment system . G.. collection and treatment system
. Placement of ash on-slte as clean . Groundwater and vadose zone . Groundwater and vadose. zone
material monitoring wells monitoring wells
. No guard and fence . Long-term O&M . Long-term O&M
. Urnlted guard and fence . Umlted guard and fence
ALT #7: SOFT MATERIAL AL T #8: SELECTIVE IN SITU ALT #9: SELECTIVE IN SITU
SOUDIFICA TlON SOLIDIFICATION WITH EXCAVATION SOLIDIFICATION WITHOUT EXCAVATION
. Characterization of sumps using cone . Characterization of sumps using . Characterization of sumps using cone
pentrometer tests calibrated with cone pentrometer tests calibrated pentrometer testa calibrated with
borings with borings borings
. Subsurface cut-off walls . Subsurface cut-off walls .. Subsurface cut-otf walls
. Slope stability Improvements and . Slope stability I~provements and . Slope stability Improvements and
retaining walls retaining walls retaining walls
. In situ solidification of soft material . excavation and off-site treatment . In situ solidification of Identified zones
(soli cover, drilling mud, tar, and and disposal of arsenic of tar and drilling mud, Including the
contaminated soli, Including the contaminated material. arsenic In Sump fi..1
arsenic In Sump R-1) . In situ solidification of Iden1lfled . Capture and treatment of emissions
. Capture and treatment of emissions zones of tar and drilling mud from the solidification process
. from the solidification process . Capture and treatment of emISsions . Grading 01 solidified material
. . Grading of solidified material from the solidification process . Installation of RCRA-equlvalent cap
. Installation of RCRA-equlvalent cap . Excavation and off-slte treatment . Ga. collection and treatment system
. Gas collection and treatment system and disposal 01 selected tar material . Groundwater and vadose zone
. Groundwater and vadose zone . Grading of solidified material monitoring wells
monitoring we.!ls . Installation of RCRA-equlvalent cap .. . Long-term O&M
. Long-term O&M . Gas collection and treatment system. . Umlted guard and. fence
. Umlted guard and fence . Groundwater and vadose zone
monitoring wells
. Long-term O&M
. Umlted guard and fence
27
-------
T Vegetation
Approximate . . . . . .
. .
Depths .
2'- 0" . . . . Topsoil
of . . . .
. . .
+ . . . . . .
Layers . .
. .
c:::> c:::> c:::> c:::> c:::> Water Drainage
c:::> c:::> c:::>
l' - 6" c:::> c:::> c:::> c:::> c:::> Granular Sand
c c c
+ c:::> <:::) c:::> c:::> c:::> <:::) c c:::>
c:::> c:::> c:::>
. Geotextile
HDPE Liner.
~ 2' - 0"
+ Bentonite/Clay Mix
Geotextile
-
- -
-
2' - 0" - - - Gas Collection
+ - - -
- -- - - -
- - - - oundation. Soil Layer
-
WASTE MA TERIALS
FIGURE 5 RCRA-Equlvalent Cap
-------
9.3 Alternative #3 RCRA-Eauivalent Containment
Major Components of the, RemedIal Alternatlve
The major features of this alternative include constructing a secure, on-site hazardous waste landfill unit
that meets the current State of California and Federal RCRA requirements. It also includes excavation of
all waste materials and contaminated soil, excavating under engineering structures (enclosures)' and
placing the waste, and contaminated soils in the newly constructed unit, and implementing RCRA
requirements for site closure and post-closure maintenance. .
The emissions from the enclosures would be collected and treated through an air treatment system. The
air treatment system would be designed to treat for particulates, organic emissions (vol,atile and semi-
volatile), and sulfur dioxide.
ContaInment Components
A multilayer cap syStem would control air emissions escaping from landfill and limit infiltration of surface
waters and precipitation into the landfill. Gases emitted by the landfill would be collected and sent to a
sulfur dioxide scrubber and granular activated carbon gas treatment system. Each of these systems
. would be designed, constructed, and operated to conform to current State of California and Federal RCRA
requirements governing hazardous waste landfills. The final proposed multi-layer cap design of this
alternative would consist of a foundation layer, a gas collection layer, a compacted soil barrier layer, and
a vegetation layer (see Figure 5). Slope stabilization, final grading, and recontouring of the site would be
performed.
Approximately 121,200 cubic yards of contaminated soil and hazardous waste would be excavated and
re-deposited in a landfill with a final re-disposal volume of 151,700 cubic yards due to re-handling. Slope
stabilization, final grading, and recontouring of the site would be performed.
Time and Cost Components
The estimateq time to implement this remedy is 5 years, with actual field work taking 4 years. The
estimated capital (1990), operation and maintenance (yearly), and total present worth (1994) costs are
$88,794,000, $828,000, and $135,740,000, respectively.
9.4 Alternative #4 Excavation and On-Site Rotary Kiln Incineration
Major Components of the Remedial Alternative
The major features of this alternative are excavation and on-site rotary kiln incineration. This alternative
includes excavation of all waste materials and contaminated soil under engineered structures (enclosures)
to control air emissions. The small volume of waste material having elevated levels of arsenic would be
treated off-site and disposed of at a RCRA facility. The excavated non-arsenic contaminated materials
would be transported to a waste storage enclosure and then to a waste-feed pretreatment enclosure and
finally to a rotary kiln incinerator, all located on-site. Slope stabilization; final grading, and recontouring
of the site wo~ld be performed.
The emissions from the enclosures and the rotary kiln incinerator would, be collected and treated through
air treatment systems. The air treatment system for the enclosures would be designed to treat for
particulates, organic emissions (volatile and semi-volatile), and sulfur dioxide. The air treatment system
for the rotary kiln incinerator would be designed to treat for particulates, organic 'emissions (volatile and
29
-------
semi-volatile), carbon oxides, nitrous oxides, and sulfur oxides.
Treatment Components
Approximately 121,200 cubic yards of contaminated soil and waste would be excavated and treated
through rotary kiln incineration. The incineration process would destroy 99.99% of the principal organic
hazardous constituents. The results of a rotary kiln incineration treatability study demonstrated that ash
from the incinerator would be non-hazardous and would be used as backfill in excavated sumps. Reter
to Demonstration of a Trial Excavation at the McColl Superfund Site, AppliCations Analysis Report dated
October 1992 and the McColl Site Thermal Destruction Analysis Report dated October 1 ~91 for .further
information. .
Time and Cost ComponentS:
The estimated time to implement this remedy is approximately 7.1 years, with actual field work taking 4.3
years. The estimated capital (1990), operation and maintenance (yearly), and total present worth (1994)
costs are $167,863,000, $828,000, and $226,354,000, respectively.
9.5 Alternative #5 Full In-situ SOlidifiCation with a RCRA-Eauivalent Cae
Major Components of the Remedial Alternative
The major features of this alternative are full in-situ solidifiCation of the cover material, drilling mud, tar, and
char wastes in the Ramparts and Los Coyotes sumps. In addition to slope stability improvements, control
and treatment of emissions would be handled by a shroud system routed to an air pollution control train.
Also, grading of the solidified waste material and closure of the site with a RCRA-equivalent closure
system followed by placement of top soil and re-vegetation would be performed.
Treatment Components
Approximately 121,200 cubic yards of hazardous waste & contaminated soil would be treated under this
alternative.
The solidification process is envisioned as a multiple step procedure. The first step is the lime slurry
neutralization process for the entire depth of the sump. The second step will consist of the a solidifiCation
. pass down to 30 feet in depth. The third step will be another solidification pass for depths greater than
30 feet. Three of the deeper sumps (L-5, R-2, and R-6) would require the deep solidifiCation pass. All
hazardous material and contaminated soil would be treated using the . in-situ sOlidifiCation process.. Only
the metals, some of the semi-volatile organics, and the corrosive characteristics of the wastes would be
treated by the sOlidifiCation process. Volatile organic compounds and sulfur dioxide would be liberated
from the waste and then captured and treated through an air treatment system using a lime based
scrubber and an activated carbon unit.
Time and Cost Components
The estimated time to implement this remedy is 7.5 years, with actual field work taking 5.6 years. The
estimated 'capital (1990), Operation and maintenance (yearly), and total present worth (1994) costs are
$68,446,000, $739,000, and $106,696,000, respectively. .
30
-------
9.6 Alternative #6 Full In-situ Solidification with a Clav Cap
Major Components 0.1 th~ Remedial Alternative
The major features of this alternative include full in-situ solidification of the cover material, drilling mud,
tar, and char wastes in the Ramparts and Los Coyotes sumps. Control and treatment of air emissions
would be performed using a shroud system routed to air pollution control trains, grading of the solidified
waste material, and closure of the site with clay cap cover system followed by placement of top soil and
re-vegetation.
Treatment Components
The components of this alternative are the same as Alternative #5 Full In-situ solidification with the.
exception of the cap. This alternative includes a clay cap rather than a RCRA-equivalent cap.
Time and Cost Components
. The estimated time to complete this remedy is 7 years with actual field work taking approximately 5.1
years. The estimated capital.(1990), operation and maintenance (yearly), and total present worth (1994)
costs are $58,000,000, $739,000, and $97,000,000, respectively. .
9.7 Alternative #7 Soft Material Solidification
Major Components 01 the .Remedlal Alternative
The major feature of this alternative is solidification treatment of waste and cover materials above the
"> char/soft material interface in each of the sumps. /n addition, slope Stability improvements and inStai/ation
of slurry cut-off walls would be included. Air emissions would be controlled and treated by the use of a
shroud system routed to air pollution control trains. Also, grading of the solidified waste material and
installation of a RCRA-equivalent cap followed by placement of top soil and re-vegetation would occur.
Treatment Components
Approximately 55,280 cubic yards of material would be solidified using this alternative (See Selected
Remedy for specific details).
Time and Cost Components
The estimated. time to complete this remedy is approximately 4.7 years with actual field work. taking
approximately 2.8 years. The eStimated capital (1990), operation and maintenance (yearly), and total
present worth (1994) costs are $46,073,000, $828,000, and $78,620,000, respectively. .
9.8 Alternative #8 Selective In Situ Solidification with Waste Excavation
Major Components 01 the Remedial Alternative
This alternative was developed by the McColl Site Group and submitted to EPA on February 12, 1991.
For a more detailed explanation of this alternative, see the Selective Excavation Treatment and RCRA .
Equivalent Closure Report prepared by Environmental Solutions, dated February 12. 1991.
In general, this plan includes pre-design cone penetrometer testing, treatment of selected materials that
cause seeps, removal of arsenic hot spots, placement of crib retaining walls, slurry walls, surface water
31
-------
control, placement of a RCRA-equivalent cap, and a commitment to a site maintenance, monitoring, and
security program.
Treatment Components
Approximately 33,000 cubic yards of material would be treated under this alternative. This process is
envisioned as a two step procedure. The first step is a lime slurry neutralization process. It is expected
that this step will be achieved at an average penetration rate of 0.4 feet/minUte. The second step would
consist of the solidification pass down to 30 feet in depth. Under this alternative none of the sumps would
require a second solidification pass. The hazardous material would be processed using the in-situ
solidification process. It is expected that only the metals and the semi-volatile organics would be treated
during this process. Volatile organics and sulfur dioxide would be liberated from the waste and then
. captured and treated through an air treatment system using a lime based scrubber and activated carbon.
Time and Cost Components
The. estimated. time to complete this remedy is approximately 6 years with actual field work taking
approximatelY 4 years. The estimated capital (1990), operation and maintenance (yearly), and total
present worth (1994) costs are $37,000,000, $828,000, and $79,000,000, respectively. .
9.9 Alternative #9 Selective In-Situ Solidification without Excavation
Major Components of the Remedial Alternative
This alternative is identical to Alternative #8 with the exception of the excavation portion. No excavation
would be undertaken with this alternative.
Treatment Components
Same as Alternative #8
Time and Cost Components
. The estimated time to complete this remedy is approximated 4.3 years with actual field work taking
approximately 2.2 years. The estimated capital (1990), operation and maintenance (yearly), and total
. present worth (1994) costs are $37,729,000, $828,000, and $67,463,000, respectively.
10.0 NINE EVALUATION CRITERIA
EPA uses nine criteria to. evaluate alternatives for cleaning up a National Priorities Ust site. The nine
criteria are summarized below. In order for an alternative to be.eligible for selection, it must meet the first
. two criteria described below, called threshold criteria The next fIVe criteria are known as balancing
criteria The final two criteria are modifying criteria (See 40 CFR 300.430(e».
1. Overall Protection of Human Health and the Environment
Addresses whether or not a remedy provides adequate protection and describes how risks posed through
each pathway are eliminated, reduced, or controlled through treatment, engineering. control~, or
institutional controls. . . .
2. Compliance with Applicable or Relevant and Appropriate Requirements (ARARs)
/
32
-------
Addresses whether or not a re'medy will meet certain federal and state environment laws and regulations,
and provides grounds for waiving a particular ARAR.
3. Long-term Effectiveness and Permanence
Refers to the ability of a remedy to maintain reliable protection of human health and the environment over
time, once the remedy has been implemented.
4. ,Reduction of Toxicity, Mobility, or Volume through Treatment
Refers to the ability of a remedy to reduce the toxicity, mobility, or volume thr()ugh ,treatment of the,
hazardous components present at the site. '
5. Cost
Evalu~es the estimated capital, operation and maintenance costs, and 30 year present worth of each
alternative.
6. Short-Term Effectiveness
Addresses the period of time needed to complete the remedy, and any adverse impact on human health
and the environment that may be posed during the construction and implementation period, until the
remedy is fully implemented.
7. Implementability
Refers to the technical and administrative feasibility of a remedy, including the availability of materials and
services needed to carry out a particular option.'
8. State Acceptance
Indicates whether, based on its review of the information, the state concurs with, opposes, or has no
comment on the preferred alternative.
9. Community Acceptance
Indicates whether community concerns are addressed by the remedy and whether or not the community
has a preference for a remedy.' . '
10.1 Comparative Analvsis of Alternatives Aaainst the Nine Criteria
For detailed information on the individual analysis of the alternatives against each of the nine criteria, refer
to the Nine Criteria Analysis For the McColl Superfund Site, dated August 1992.
The comparative analysis portion of the nine criteria evaluation is a qualitative assessment of the relative
strengths/weaknesses of the alternatives in relation to the nine criteria This assessment appears in Table
21.
The assessment compares the level of confidence that EP A has in the ability of the identified remedy to
aC!'1ieve the objectives of a given criterion based on the information presented in the individual
assessment portion of the nine criteria analysis. This is true for all of the criteria except cost, for which
the 30 year present worth cost is presented. The cost figures have a +50/-30 percent confidence level.
33
-------
Protection of Human
Health and the
Environm~n~
Compliance with
Applicable or Relevant
and Appropriate
Requirements
(including application of
waivers)
Long term effectiveness
and permanence
Reduction in toxicity,
mobility, and volume
through treatment
Short term
effectiveness
Implementability
Total30-year present
worth cost In 1994
dollars (In millions)
State acceptance
Community acceptance
TABLE 21
NINE CRITERIA LEVEL OF CONFIDENCE ANALYSIS
Np . RCRA RGRA.
~ctlon . Closure.. Containment
Low
NA
NA
NA
NA
NA
NA
NA
Low
.:>. .....,.:. :.:
.. .
On-Slt~ . ....
Rotary. .
Kiln.
. ..:..:
High
High
High
High
Moderate
Low
226 M
Low
Low
Hlgh= High level of confidence that criterion will be achieved
Moderate = Moderate level of confidence that criterion will be achieved
Low = Low level 01 confidence that criterion will be achieved.
NA= Not Applicable
High
High
High
High
.Low
Moderate
Low
Low
High
Moderate
High
37M
I
Low
136 M
Low
Low
Low
Low
.soft........:. .........
Material
Solidification
High
High
Moderate
Moderate
Moderate
Moderate
79M
Moderate
Moderate
4
.
.. Selective
In:'Sku. .:
Solidification.
without. . .
excavation
High
High
. Moderate
Moderate
Moderate
Low
68M
Low
Moderate
~elective .
. '":'Situ
Solidification.
with. .
. .excavation.
High
High
Moderate
Moderate
Moderate
Low
79M
Low
Moderate
'" .... ..
FlJUIr)~itli .
Solidification. :
withFtCRA .
cap
.:.....
High
High
High
High
Moderate
Moderate
107 M
Moderate
Low
Fullin-Sltu:
. Solidification
with clay
cap
High
High
High
High
Moderate
Moderate
97M
Low
Low
-------
The assessment assumes that, with the exception of no action, all of the alternatives will provide a
minimum level of achievement under each criterion. The alternatives are compared in terms of level of
confidence (high, medium, low) in the ability of each alternative to achieve the goals of the specific
criterion under consideration.
EPA has assigned a high level of confidence to the first two criteria (Overall Protection of Human Health
and the Environment and Compliance with ARARS) for all alternatives except No Action. EPA believes
that each alternative except for the no action would achieve these threshold criteria
Descriptions and examples in parentheses of levels of confidence for the five balancing criteria, with the
exception of cost, are described in Appendix B.
For the modifying criteria, the levels of confidence for state acceptance and community acceptance
reflects EPA's assessment of their support for the respective remedies based on comments received.
EPA believes this comparative assessment allows an objective comparison of the tradeoffs between the
respective alternatives within a specific criterion and across all of the criteria Based on both individual
assessment and the comparative assessment, EP A weighed the alternatives and selected a preferred
alternative for public review and comment.
11.0 THE SELECTED REMEDY
Based upon consideration of the requirements of CERCLA, the detailed analysis of the alternatives using
the nine criteria, and public comments, EPA, after consultation with DTSC, has determined that Alternative
#7 (Soft Material Solidification) is the most appropriate alternative for the McColl Superfund Site. Due to
technical uncertainties that cannot be resolved until field implementation, EPA has determined that it is
prudent to add a contingency to the selected' remedy. Therefore, EPA believes that Soft Material
Solidification with a contingency of RCRA-equivalent closure is the most appropriate remedy.
The selected remedy will involve solidification of all soft material in each sump above the char/soft material
interface. EP A has selected Soft Material Solidification rather than closure alone be~ause of the treatment
component of solidification, which reduces the toxicity, mobility, and volume of hazardous waste while
providing greater long-term effectiveness and permanence. Treatment of all soft material would best
achieve the goals for solidification while providing the best balance of the nine criteria
11.1 Goals of the Selected Remedv
The goals of solidification at the site are: (1) to solidify all of the soft material to minimize the potential
threat of seeping material in the future; (2) to prevent the release of volatile inorganic (sulfur dioxide) and
organic contaminants (benzene and tetrahydrothiophenes), to the maximum extent practicable, through
chemical and physical reactions; and (3) to neutralize. all of the soft material to eliminate the hazardous
characteristics of corrosivity. In addition, as a result of the introduction of water and reagents to the
existing soft material, it is also prudent to ensure that (4) the solidified material possesses internal strength
characteristics (unconfined compressive strength) to support the RCRA-equivalent cap that is an integral
part of the remedy. .
11.2 Components of the Selected Remedv
This alternative consists of the following components:
- Excavation and decontamination of shallow metallic sprinkler pipes in. the Los Coyotes area, followed
35
-------
by off-site transportation. and disposal.
- Characterization of eact) sump using field. methods (such as cone penetrometers, correlated with
subsurface borings) to determine the top of the char layer in each sump.
- Installation of subsurface slurry cut-off walls around the Upper Ramparts sumps, and a separate slurry
cut-off wall around the Lower.Ramparts and the Los Coyotes sumps (see Figure 6).
- Slope stability improvements are to be determined during design in unstable slope areas (see Figure
7). .
- In-situ solidification of the soil, drilling mud, tar wastes, and contaminated soils above the char. layer.
The proposed plan presented a conceptual approach of using two 5-foot diameter augers for the.
solidification. However, the final decision on the equipment size will be determined during design.
- The site will be graded (to contour the site, and to allow movement of waste away from homes) and a
RCRA-equivalent cap, including a permanent gas collection and treatment system, will be placed over the
solidified sumps.
- Long-term operation and maintenance including installation of groundwater and vadose zone monitoring
wells, monitoring of. the groundwater, and a gas collection system.
- Site security and routine site maintenance.
Prior to the initiation of in-situ treatment operations, a subsurface lime-slurry layer will be placed in each
sump, and an emission suppressing foam will be applied over .the entire ground .surface of the waste
sumps to help control emissions. The foam is expected to form a tough, flexible membrane over the
sumps. .
Emissions will also be controlled during solidification using a shroud system around the augers. The
shroud will be maintained at a negative pressure so that emissions will flow into the gas treatment system.
The conceptual design of the gas treatment system consists of two stages of scrubbing with lime to
reduce sulfur dioxide concentrations, followed by granular activated carbon units to absorb residual
hydrocarbons. The primary scrubber will be a venturi scrubber and is ~xpected to remove approximately
90 percent of the sulfur dioxide from the gas stream, condense out-approximately 75 percent of the
volatile hydrocarbons and 95 percent of the semi-volatile hydrocarbons, and remove most of the'
particulate matter. ..
The secondary scrubber will be a packed-column scrubber that also utilizes lime as the scrubbing
solution. It is estimated that the secondary scrubber will also have a 90 percent efficiency in removing
sulfur dioxide from the primary scrubber effluent air stream. A granular activated carbon unit will be used
to reduce total hydrocarbon emissions before the air stream is vented to the atmosphere.
11.3 Depth of Treatment for the Selected Remedv
Based on data gathered to date, the waste material is estimated to be distributed across the site in 12
sumps which range from 17 to 55 feet deep. Each of the sumps consists of several layers of soils ~d'
waste (soft materiaO and then char waste. The thickness of each of the different layers varies from sump
to sump. Based on existing field data, EPA estimates that the continuous char layer starts approximately
6 - 17 feet below the ground surface (See Table 22). Based on the depths in Table 22, EPA estimates
that 55,280 cubic yards of .contaminated material will be treated.
36
-------
Rosecrans Avenue
McCOLL SITE
c
~c
1:.
o
&L
,b .
Ii
C
Ralph B. Clark
Regional Park
Co)
.....
LEGEND
Los Coyotes
Golf Course
R- t Rwnparts Sump Number
I.-I Los Coyoles Sump Number
__n: 511111)' Walls.
FIGURE 6 Slurry Walls
,
N~~S,., t
-------
Rosecrans Avenue
McCOLL SITE.
Ralph B. Clark
Regional Park
ell
>
~
c
C
ell
~
m
...
ai
II.
w
CD
l.EGEND
Los Coyotes
Gol"Course
R-I Ramparts Sump Number
L-I Los Coyotes Sump Number
m Arcas to be reinforced
iii with concrete slabs
FIGURE 7 Slope Stability Improvements
A
No"o s,., t
-------
TABLE 22
ESTIMATED DEPTH TO CHAR LAYER IN THE SUMPS
Maximum Depth to Top of Char
.Sump. .. .. (feet) .
,
L1 15
L2 10
L3 14
L4 14
L5 15
L6 12
R1 15
R2 15
R3 17
R4 10
R5 10
R6 6
39
-------
In selecting Soft Material Solidification, EPA intends to treat by solidification all of the material in each
sump above the char/soft. material interface. The performance criteria that will guide the decision on
whether Soft Material Solidification is technically implementable are based in part on the estimated depths
of the char/soft material interface shown in Table 22.
However, these depths could be either overestimated or underestimated due to the limited nature of the
existing data The actual depth of the soft material layer in each sump will be determined during design.
If the depth of the char/soft material interface is determined to be at a shallower dep~h than estimated in
Table 22, EPA is committed to treating only the soft material necessary to reach the char/soft material
interface. This will result in treatment of less soft material than estimated in the SROA II. .
If the depth of the char/soft material interface is determined to be at a greater depth than estimated in
Table 22, EPA will determine how much, if any, of the soft material below the estimated depths will be
solidified. EPA recognizes that a limit on depth for solidification may need to be established during
design. The ultimate depth for solidification will be based on data collected during design, and will be
guided by the performance criteria and the goals for Soft Material Solidification. This scenario could result
in treatment of more soft material than estimated in the SROA II.
The scenarios discussed above are based on EPA's conceptualization of a typical sump presented in
Figure 4. Given the uncertainty related to the relative flatness of the char/soft material interface, it is
possible that under e.ither scenario given above that some soft material may remain untreated and that
some of the char material may also be treated. EPA expects that these slight variations in the type and/or
volume of waste treated would not be considered significant changes to the remedy.
If the depth of the char/soft material interface is different than current estimates such that the volume of
treated material is significantly altered (greater or smaller), EPA anticipates that modifications to this ROD
might be necessary. EPA believes that modifications to the selected remedy resulting from changes in
estimated volume of material treated due to a change in the definition of the char/soft material interface
can be accomplished through an Explanation of Significant Differences (ESD). Notice of a change to the
remedy through an ESD would not require an additional public comment period and would not delay
remedy implementation. The remedy as. modified could be implemented as soon as the changes are
identified during design.
11.4 Slurrv Walls. Retainina Walls. and RCRA-Eauivalent Cap
The selected remedy includes slurry cut-off walls, retaining walls, and a RCRA-equivalent cap. The.cut-off
walls are intended to keep the wastes from migrating laterally. It is anticipated that two walls will be
needed, one that will surround the Upper Ramparts area and one that will surround the Lower Ramparts
and Los Coyotes area
With the addition of material during solidification and placement of the cap, retaining walls may be needed
on the slopes of the Upper Ramparts, Lower Ramparts, and Los Coyotes portions of the site. A detailed
evaluation of all of the slopes will need to be done during the design phase and the actual size of those
walls should be determined at .that time.
The RCRA-equivalent cap will be necessary to ensure that water does not get into the waste and that
gaseous emissions are not released to the atmosphere without treatment. This will be accomplished
through the use of clay and gravel layers, synthetic liners, and water and gas collection systems. It is
estimated that the cap could be up to nine feet thick. The actual height ~d materials to be used will be
determined during the design phase of this project. .
40
-------
11.5 Residual Generation
Some residuals are expected as a result of implementing this remedy. These materials are scrubber
effluent and spent activated carbon. They will be treated as hazardous waste and disposed of off-site at
a facility permitted to accept such waste. In addition, approximately 14,000 cubic yards (40% of treated
material) of additional material will be created due to swell during treatment. EPA anticipates that this
material will be considered non-hazardous and will be graded across the site.
11.6 Cost and Time
The project implementation cost for this alternative is $46,073,000 (1990 dollars). The annual operation
and maintenance costs are $828,000. The net present value (1994 dollars) for capital cost, and operation
and maintenance cost for the 30 year design is $78,620,000. For a detailed breakdown of costs see.
Appendix C of the SROA II.
Implementation of this remedy is expected to take approximately 4.7 years, of which approximately 2.8
years is utilized for actual in-situ solidification activities. The remedial timeframe is based on the use of
. two in-situ drill rig units, support equipment, crews, and the requirement of a single sump pass for
solidification. It is also assumed that the rigs would operate 300 days per year and treat wastes at a rate
of 100 cubic yards per day per drill rig. .
11.7 Risks and Hazards
The pathway of concern when evaluating the risks and hazards from implementation of Soft Material
Solidification is inhalation of organic and inorganic substances. EP A anticipates potential exposure from
fugitive emissions and emissions related to the air treatment systems of the cap and shroud. The primary
compounds of concern are those listed in Table 5.
The carcinogenic risks associated with the implementation of this alternative range from 6x1 0.9 (worke~
to 6x10-7 (child) under an average case exposure scenario. For the RME case, the range is from 1x10
(worker) to 1X10-9 (child). These risks fall within EPA's acceptable risk range.
The ranges of receptor HI (noncarcinogenic risks) for this alternative are 0.00002 (worker) to 0.005 (child)
for the average case and the range is 0.00004 (worker) to 0.03 (child) for RME. cases. EPA has
determined an HI greater than 1.0 indicates that there is potential for a noncarcinogenic health effect to
occur as a result of exposure to chemicals released from the site. The estimated His are acceptable to
EPA. Overall, it has been determined that this alternative is protective of human health and the.
environment. .
11.8 One Sump Test: Performance Criteria for the Selected Remedv
Soft Material Solidification will be applied first to one sump to determine if it is technically implementable.
In deciding whether Soft Material Solidification is technically implementable, EPA will consider at a
minimum the following eight performance criteria:
1. Ability to control gener.atlon 01 future seeps:
- Ability to perform sufficient mixing of waste and reagents to prevent seepage of tar material from treated.
material .. .
41
-------
I--
I
2. Ability to control emissions during treatment process:
- Ability to meet air ARARs
3. Ability to render waste material non-hazardous:
- Ability to eliminate through solidification the corrosivity characteristics of the waste material
. .
4. Ability to support RCRA-equivalent cap:
- Unconfined compressive strength sufficient to support RCRA-equivalent cap both short and long term
. 5. Ability to move or grade the treated material:
- Shear strength sufficient to allow for grading of material
- Emission potential of treated material low enough to allow
grading
6. Ability to control nuisance to surrounding community:
- Ability to control noise impacts to within acceptable levels
for surrounding community
i .
I
- Ability to control odor impacts to within acceptable levels
for surrounding community
- Ability to control visual impacts to within acceptable levels
for surrounding community
7. Estimated field time:
- Ability to control field time to four to six years
8. Estimated cost of completion:
- Ability to control costs to a thirty (30) year present worth range of $79,"000,000 to $120,000,000.*
11.8.1 Evaluation of Performance Criteria
At the conclusion of the one sump test, EPA will consider whether the results of the one sump test, when
. extrapolated to site-wide implementation, deviate excessively, both individually and collectively, from the
expected results set forth in these eight criteria EPA recognizes that the interpretation of the test results
will require qualitative judgement by EPA, in consultation with the State, regarding the implementability
of Soft Material Solidification site-wide. These criteria are guidelines that EPA will use as parameters for
decision-making. Deviation from these criteria does not automatically trigger implementation of the
contingent remedy. . EPA will evaluate the extent of deviation from these criteria and determine if Soft
Material Solidification continues to be the most appropriate remedy for the s.ite.
* $120,000,000 is EPA's initial cost estimate of $79,000,000 with fifty (50) percent escalation, which is
consistent with +50/-30 percent cost estimating performed during RIIFS phase of project.
42
-------
If. EPA determines that Soft Material Solidification is technically implementable, it will be implemented on
the remaining eleven sumps. The amount of material to be solidified in these remaining eleven sumps
is addressed in Section 11.3 above.
EP A currently envisions at least two scenarios that would result in a decision not to implement Soft
Material Solidification site-wide following the one sump test. The information necessary for the evaluation
of these two scenarios will be. gathered during the implementation of Soft Material Solidification on sump
L-4 and from other design work. The first scenario. would arise if for purely engineering reasons Soft
Material Solidification is unable to meet the first six criteria. Under this scenario, EPA will immediately
proceed with the implementation of the contingent remedy of RCRA-equivalent closure.
The second scenario would be that Soft Material Solidification is viable from .an engineering perspective
but, in EPA's judgment, the cost and/or time frame for implementing the remedy site-wide excessively
exceeds the guidelines of criteria 7 and 8. Under this scenario, EPA will immediately proceed with the
implementation of the contingent remedy of RCRA-equivalent closure. .
11.9 Continaencv Remedv
Although EPA is confident that Soft Material Solidification will be successful at the McColl site, there is
inherent uncertainty whenever a remedy involves the implementation of a proven treatment technology
in an innovative manner. Therefore, EPA has decided to include RCRA-equivalent closure (Alternative #2)
as a contingent remedy in the event EPA determines that Soft Material Solidification is not technically
implementable as discussed above.
If RCRA-equivalent closure is chosen it would consist of the following: constructing a multilayer cap over
the untreated sumps with a gas collection and treatment system to prevent infiltrati9n of water and release
of hazardous air emissions; building subsurface . slurry walls around the sumps to prevent migration of
water into the. waste and outward migration of contaminants; stabilizing steep slopes on the site with
retaining walls; and conducting groundwater monitoring. Operation and maintenance will be necessary
in perpetuity at the site, which include site security and routine site maintenance.
During the Design phase, EPA will update the existing Community Contingency Plan. This document
deals with monitoring of emissions and implementing responses to emissions when necessary .in order
to protect the health and safety of the community during field activities. -
11.9.1 Cost and Time
The project implementation cost for the contingency remedy is $14,737,000 (1990 dollars). The annual
operation and maintenance costs are estimated at $828,000. The net present value (1994 dollars) for
capital cost and operation and maintenance cost for 30 year design is $36,722.000.
Implementation of this remedy is expected to take approximately 2.2 years, of which approximately 1.3
years is utilized for actual field activities.
11.10 End Use of the McColl Site
After implementation of the selected remedy, the McColl Site will have characteristics of a closed landfill .
for purposes of end use. While the property owners of the McColl site. will have discretion to propose end
uses, EPA must ensure that the end use is consistent .with the implemented remedy. While EPA is not
approving a particular end use in this ROD. potential end uses could include a nature park, recreational
park, or golf course. .
43
-------
As part of this remedy, EPA .is also imposing institutional controls on the site property to prevent uses
inconsistent with the implemented remedy. Because waste materials will remain under the cap, these
controls will prevent construction of structures or addition of materials that could compromise the integrity
of the implemented remedy.
EPA will require improvements to the Site necessary for the succeSsful implementation of the remedy.
Off-site improvements cannot.be incorporated into this ROD. However, EPA intends to work closely with
interested groups including the City of Fullerton, the landowners, the PRPs and the community to explore
the need for and implementation of improvements to the property surrounding the site.
A maintenance program will be implemented and will involve regular inspections for: differential settlement;
soil cover integrity; the need for additional grading or vegetation; sediment and erosion; and gas
collection/treatment system operation. The design of any end use would have to be compatible with the
design and operation and maintenance of the cap. In addition, long-term groundwater and vadose zone
monitoring wili take place.
12.0 STATUTORY DETERMINATIONS
Under CERCLA section 121; EPA must select remedies .that are protective of human health and the
environment, comply with applicable or relevant and appropriate requirements (unless a statutory waiver
. is justified), are cost-effective, and utilize permanent solutions and altemative treatment technologies or
resource recovery technologies to the maximum extent practicable. In addition, CERCLA includes a
preference for remedies that employ treatment that permanently and significantly reduce the volume,
toxicity, or mobility of hazardous wastes as their principal element. The following sections discuss how
the selected remedy and the contingency remedy meet these statutory requirements.
12. 1 Protection of Human Health and the Environment
EPA has determined that the selected remedy, Soft Material Solidification, is protective of human health
and the environment by conducting a risk assessment which evaluated both the implementation and long
term risk associated with the alternative. This risk assessment evaluated both carcinogenic and non-
carcinogenic risks associated with the project over a lifetime. The maximum carcinogenic risk and non-
carcinogenic hazard estimated for the project are 1 x 10-6 and 0.03 respectively. . EPA considers risks
within or below 10-4 to 10-6 to be acceptable. EP A also considers non-carcinogenic hazards with an
hazard index (HI) value of 1.0 or less to be acceptable. EPA also believes that the unquantified risk and
hazard due to the waste seepage at th~ site will be effectively reduced as a result of the implementation
of the selected remedy. Therefore, EPA believes that the selected remedy is protective. of human health
and the environment. The risk assessment also indicate that the contingency remedy, RCRA-equivalent
closure, is protective of human health and the environment using the above definitions of acceptable risk
and hazard.
12.2 Compliance with Applicable or Relevant and Appropriate ReQuirements (ARARs)
The selected and contingent remedy will comply with all ARARs. The ARARs are presented in Appendix
C. .
12.3 Cost Effectiveness
This remedy will achieve short and long term effectiveness and permanence, and reduCtion of toxicity,
mobility and volume of hazardous waste through treatment, at an estimated cost of $79,000,000.
Therefore, the selected remedy provides an overall effectiveness proportionate to its costs, when
compared to the :ost effectiveness of the. other alternatives consider~d. If Soft Material Solidification is
44
-------
not technically implementable, the contingent remedy of RCRA-equivalent closure would provide overall
effectiveness proportionate to its costs, when compared to the cost. effectiveness of the remaining
alternatives.
12.4 Utilization of Permanent Solutions and Alternative Treatment Technoloaies (or Resource Recoverv
Technoloaies) to the Maximum Extent Practicable
The selected remedy utilizes permanent solutions and alternative treatment technologies to the maxim-urn
extent practicable. Soft Material Solidification provides the best balance of trade-offs among the nine
criteria in combining treatment technologies with containment technologies. -
If the selected remedy is not technically implementable based on the performance criteria pr-ovided in this
ROD, the contingency remedy (RCRA-equivalent closure) will provide the utilization of permanent solutions
and alternative treatment technologies to the maximum extent practicable. . .
12.5 Preference for Treatment as a Principal Element
EPA believes that the selected remedy effectively treats the principal threats at tne site. There are three
significant pathways (inhalation, direct contact, ingestion) identified in the Baseline Public Health
Evaluation.
The principal threats for the inhalation pathway are benzene and sulfur dioxide. The benzene and sulfur
dioxide will be effectiv.ely treated through two mechanisms. During the implementation of the solidification
portion of the selected remedy, the benzene and sulfur dioxide found in the soft material layer will be
liberated and captured in the shroud of the drilling rig. They will then be processed through an air
treatment System. After installation of the RCRA equivalent cap, any remaining benzene and sulfur dioxide
will be captured by the cap itself and processed through an air treatment system.
The principal threat for the ingestion and direct contact pathways is arsenic. The arsenic found in the soft
material layer will be effectively treated during the solidification process.
EPA believes that the preference for treatment as a principal element has been addressed through the
selection of Soft Material Solidification. Soft Material Solidification will treat those hazardous volatile
organic compounds emitted during the solidification process through the air treatment system associated
with the solidification process. Hazardous semi-volatile .organic compounds will be treated either through
the ~olidification process or through the air treatment system associated with the solidification process.
Soft Material Solidification will also treat the acidic waste material in the soft material layer and is expected
to render it non-hazardous. . .
. .
If Soft Material Solidification is not technically implementable, the contingent remedy, while primarily a
. containment remedy, will provide for limited treatment of hazardous volatile, semi-volatile, and inorganic
compounds through the air treatment system of the RCRA-equivalent cap.
13.0 DOCUMENTATION OF SIGNIFICANT CHANGES
The Proposed Plan for the McColl Superfund site was released for Public comment in August 1992. Soft
Material Solidification with a contingensy of RCRA-equivalent closure was identified as the preferred
remedy in the Proposed Plan. EPA has reviewed all written and verbal comments submitted during the
public comment. period. After reviewing the comments received, it was determined that no significant
changes to the remedy, as originally identified in the Proposed Plan, were necessary.
45
-------
APPENDIX A
Assumptions Used to Calculate Inhalation of VQC's
-------
APPENDIX A
Assumptions used to calculate inhalation of VOCs are as follows:
Adult Residents
The inhalation rate of adult residential receptors was calculated to be 0.83 m3 (cubic meters)/hour or 20
m3/day. "
Child Residents
An average inhalation rate of 0.66 m3/hour or 16 m3/day was estimated for child residents by using the
following activity pattern and inhalation rates.
" - 48% of the time at rest and 0.4 m3/hour
- 48% of the time at light activity and 1.0 m3/ hour
- 3% of the time at moderate activity arid 3.2 m3/hour
- 1% of the time at heavy activity and 4.2 m3/hour
Country Club Worker
The inhalation rate of 20 m3/day per 8 hour work day.
Youna "Adult Recreation RecePtor
For the average case scenario, an inhalation rate of 4.2 m3/hour was assumed, based on a standard
factor for a child (aged 10 years) involved in heavy activity. For the RME case, a inhalation rate of 3.2
m3/hour was used based on an assumed moderate level of physical activity for twice the length of
exposure. The lower rate was chosen because it is expected that an individual could not maintain the
heavy physical activity implied by the 4.2 m3/hour inhalation rate for the length of exposure assumed for
the RME case.
Exposure Time
Exposure time refers to the number of hours per day an individual is exposed to chemical in air. The
following assumptions were used:
-
- Children (1-6 years) exposure time was 16 hours/day for the average case and 24 hours/day for the RME
case.
-Young adults were assumed to be 16 hours/day for the average case and 22 hours/day for the RME
case. The average and RME case exposure times for on-site inhalation exposure for these receptors was
assumed to be 1 and 2 hours/day. "
-Country Club worker was assumed to be 8 hours/day.
Exposure Freauencv
Exposure Frequency refers to the number of days in which exposure occurs per week, month or year.
The following assumptions were used: "
-Child and adult residents, and adult recreation receptors exposure frequency was 350 days/year.
-On-site young adult recreation receptors frequency exposure was assumed to be 6 days/week or 312
days/year. ". "
-Country Club worker exposure frequency was assumed to be 250 days/year.
-------
Exoosure Duration
Exposure duration is the period of time the exposure will persist. Resident receptors evaluated have been
divided into three age groups. The following assumptions were used:
Children (1-6 years old) - Average and maximum exposure durations were both 6 years.
Young adult receptor - Average and RME exposure durations were 4 and 12 years respectiVely.
Adult Residents - Average and RME durations were 5 and 18 years respectively.
Young adult recreation receptors - Average and RME exposure durations were 4 and 12 years
. respectively. .
Adult recreation receptors - Average and RME durations were 5 and 18 years respectively.
Country Club Worker - Average and RME durations were 12.5 and 25 years respectively.
Bodv Weiaht
The standard assumptions are as follows:
Adult Residents - 70 kilograms (kg)
Recreation receptors - 70 kg
Country Club workers - 70 kg
Resident children (between 1 and 6 years of age) - 16 kg
Young adults (age 7-18) - 43 kg
Averaaina Time
Based on the hypothesis that cancer risk is proportional to an average exposure to a carcinogen during
a lifetime, the averaging time for carcinogens is considered to be a 70-year lifetime. The averaging time
for noncarcinogens is based on the .exposure duration rather than a lif~ime because the adverse health
effects on noncarcinogens are believed to have thresholds and are not . believed to accumulate over a
lifetime. The noncarcinogen averaging time for each exposure. pathway is equivalent to the exposure
duration in years multiplied by 365 days/year.
The assumptions used to calculate ingestion of contaminated homegrown vegetables are as f0110ws:
The intake of chemicals through ingestion pathways is a function of the quantity of soil and vegetables
consumed, the frequency and duration of exposure, and the body weight of the receptor. Aside from the
ingestion rates, ingestion fractions, and exposure frequencies, the exposure factors for the ingestion
pathways (e.g. exposure durations and body weights) are the same as those described above for the
inhalation' pathways.
Exoosure Freauencv
The exposure frequency for incidentai ingestion of soil by on-site recreation and off-site residential and
worker receptors are the same as that used for the inhalation exposure scenarios. The exposure
frequency for ingestion of t\omegrown vegetables is assumed to be one-half of the residential exposure
frequency of 350 days/year; or 175 days/year. A lower frequency of exposure is assumed for this pathway
.because it is unlikely that an individual will eat homegrown vegetables year-round. .
-------
Soillnaestion Rate
The soil ingestion rate used for adult and children residential receptors are 100 mg (milligrams)!day and
200 mg/day respectively. The rate used for workers is 50 mg!day.
Veaetable Inaestion Rate
The total vegetable ingestion rate for all both adult and child residents was assumed to be 200 g
(grams)!day for both average and RME exposures~ Workers at off-site receptor location R23 were
assumed not to consume vegetables grown in the study area It was assumed that 50-percent of the total
intake was from leafy vegetables (e.g. lettuce) and 50 percent from vine vegetables (e.g. tomatoes).
Fraction Inaested
It is assumed that 100% of the total daily ingestion rate for soil/dust for all receptors ;s derived from
exposures associated with the McColl site. The fraction of vegetables ingested from the site is a function
of the percent of total daily vegetable ingestion that is derived from household gardens. Twenty-fIVe
percent of vegetables are assumed to be homegrown under the average case and 40-percent was
assumed for the RME cases.
The assumptions used to calculate dermal contact with contaminated soil are as follows:
. Skin Surface Area Exposed
The average and RME surface areas for children are 1,000 and 2,000 cm2 (square centimeters)!event,
respectively. The surface areas for young adult and adult residents, recreation receptors, and workers
are 2,000 .and 5,000 cm2/event for average and RME cases respectively. For the average cases, an
individual is assumed to wear a long sleeve shirt, pants and shoes. Therefore, the exposed skin surface
is limited to the head and hands. For RME cases, it was assumed that an individual wears a short sleeve
shirt, shorts and shoes. Therefore, their exposed skin surface is limited to the head, hands, forearms, and
lower legs. These scenarios suggest that approximately 10 to 25 percent of the skin may be exposed to
soil.
Soil-te-skin Adherence Factor
The soil-te-skin adherence factor of 0.5 mg/cm2 used is based on dermal exposure guidance issued by
EPA (1991).
Absorption Factor
Dermal absorption factors for chemicals of potential concern were assumed to be as follows:
PAHs (Phenanthrene, Naphthalene, 2-Methylnaphthalene) 0.1 (10%)
Bis(2-ethylhexyQ phthalate 0.04 (4%)
Arsenic 0.01 (1.%)
-------
APPENDIX B
Levels Of Confidence for Five Balancing Criteria
-------
Appendix B
Below are descriptions and examples of levels of confidence for the fIVe balancing criteria: Long Term
Effectiveness, Reduction of Toxicity, Mobility or Volume through Treatment and Short Term Effectiveness.
Lona Term Effectiveness and Permanence
A hiah level of confidence is assigned to an altemative in which the magnitude of residual' risk is
minimized through engineering controls or institutional controls that are permanent and .that do not need
long-term controls to assure minimization of residual risk. This is envisioned for altematives where a
proven technology (incineration) renders the treated material non-hazardous and long-term engineering.
and/or institutional controls.are not necessary to assure minimization of residual risk.
A medium level of confidence is assigned to an altemative in which the magnitude of residual risk is
minimized through engineering controls and/or institutional controls that are potentially permanent but not
. proven on the waste matrix present. A medium level of confidence is also assigned to an alternative in
which long-term ~ontrols to assure minimization of residual risk are necessary with the confidence in the
adequacy and' reliability of the controls high. This is envisioned for alternatives where an innovative.
technology (solidification of acid waste) is employed and a cap with gas collection is provided to assure
minimization of residual risk.
A low level of confidence is assigned to an altemative is which the magnitude of residual risk is minimized
through engineering controls and/or institutional controls. but the certainty of permanence and the
effectiveness of treatment on the waste matrix present is unknown. A low level of confidence is also
assigned to an alternative in which long-term controls to assure minimization of residual risk are necessary
controls is low; This is envisioned for alternatives where an unproven technology (in-situ steam stripping
of acid waste) is employed and a cap with unproven treatment (biodegradation to control emissions) is
provided to assure minimization of residual risk.
Reduction of Toxicity. Mobility or Volume throuah Treatment
A hiah level of confidence is assigned to an altemative in which a proven treatment technology is
employed to reduce the toxicity. mobility or volume 6f a hazardous. waste. This is envisioned for an
alternative that employs a proven technology (solidification of acid sludge) on a portion of the hazardous
waste at the site. .
A medium level of confidence is assigned to an alte'rnative in which an innovative technology is employed
to reduce the toxicity. mobility. or volume of a hazardous waste or a portion of the hazardous waste at
the site. This is envisioned for alternatives that use an innovative technology (solidification of acid sludge)
on a portion of the hazardous waste at the site. .
A low level of confidence is assigned to an alternative in which no treatment is employed to reduce the
toxicity, mobility or volume of a hazardous waste. This is envisioned for alternatives that employ non-
treatment.engineering controls (Caps, slurry walls) only.
Short Term Effectiveness
A hiah level of confidence is assigned to an- alternative if protection of the community. workers and
environment during implementation are assured and easy to achieve over.a short period of time. This is
envisioned for alternatives. where minimal disturbance of hazardous material is expected or where, if
hazardous materials are encountered. the potential for adverse impacts are minimal due to the elimination
of exposure pathways through easily implemented engineering and/or institutional controls. It is also
-------
envisioned that these control are necessary over a short period of time.
A medium level of confidence is assigned to an alternative if protection of the community, workers and
the environment during implementation are assured, but low level of uncertainty exists related to the
performance of the engineering or institutional controls employed to achieve the desired level of
protection. This is visualized for alternatives where there is reliance on innovative technologies (using a
shroud to control volatile organic compounds and sulfur dioxide emissions during solidification) for
minimizing exposure when hazardous materials are encountered. Another. scenario is for alternatives
where special operating conditions (limiting) the rate of solidification to control emissions) are employed
in the field to minimize exposure duration. This in turn leads to longer time periods until long term
protection is achieved.
. A low level of confidence is assigned to an alternative if protection of the community, workers and the
environment during implementation are assured, but a high level of uncertainty exists. related to
performance of the engineering or institutional controls employed to achieve the desired level of
protection. This is visualized.for alternatives where there is reliance on innovative technologies to provide
high levels of r~uction (Qreater than 90%) to control exposure t~ hazardous material.
Implementabilitv
A hiQh level of confidence is. assigned to an alternative where the technical and administrative
implementability is assured and the level of uncertainty in the technical aspects of implementation is low.
This is envisioned for alternatives where disturbance of hazardous rnaterial is minimized (capping) and
the technology has been implemented successfully before at similar sites (capping).
A medium level of confidence is assigned to an alternative where the technical and administrative
implementability is assured but the level of uncertainty in the technical aspects of implementability is
moderate. This is envisioned for alternatives where definition of the material of concern is easily assured
(full in-situ solidification), but ease of application of the treatment technology is uncertain (material to be
treated).
A low level of confidence is assigned to an alternative where the technical and administrative
implementability is assured but the level of uncertainty in the technical aspects of implementability is high.
This is envisioned for alternatives where excavation under an enclosure is a prime component of the
alternatives (incineration). This is also envisioned for alternatives where definition of the material of
concern is not easily assured (selective in-situ solidification with excavation).
-------
APPENDIX C
Tables of Applicable, Relevant, and Appropriate Requirements
-------
u
Ii:
(j
W
Q.
rn
cl
o
~
:c
o
I.
flequlrement
Resource Conservation and Recovery Act
(RCRA) as amended by Hazardous and
Solid Waste Amendments (HSWA) (42 USC
6901 et seq.)
. . . . .
FEPERA~ARAR.
. . . .. . De.c;rlptlon .
RCRA is the federal law providing requirements for hazardous waste management
including criteria for the identification of hazardous waste and specific standards
for the design, operation, and closure of hazardous waste treatment, storage, or
. disposal units and facilities. RCRA requirements are generally applicable to
CEACLA actions when the following conditions are met:
(1) the waste meets the RCRA criteria. for a listed hazardous waste or a
characteristic hazardous waste, and
(2) the waste Is treated, stored or disposed (as defined In 40 CFR 260.10)
after the effective date of the RCRA requirement.
RCRA identifies a solid waste as a hazardous waste if it exhibits the characteristic
properties of ignitabillty, reactivity, toxicity, or for liquid or aqueous wastes,
corrosivity. Based on available data, untreated McColl wastes are expected to
exhibit characteristic corroslvlty and toxicity. The RCRA toxicity characteristic is
based upon the leachability of designated constituents as measured by the
Toxicity Characteristic Leaching Procedure (TCLP). Specific. chemicals present at
McColl which are currently included In the toxicity criteria are:
TCLP Maximum
Concentration (mWI)
5.0
100.0
1.0
5.0
5.0
0.5
A. Characteristics of Hazardous Waste (40
CFR 261.24)
Chemical
Arsenic
Barium
Cadmium
Chromium
Lead
Benzene
EPA HW No.
0004
0005
0006
0007
D008
0018
B. Groundw.ater Maximum Concentration.
Limits (40 CFR 264.94)
Groundwater in the upper-most aquifer underlying a hazardous waste
management unit should not exceed the RCRA maximum contaminant levels
(MCLs). Chemicals at McColl that have RCRA MCLs are listed below in mg/l.
Chemical MCL (mwl)
Arsenic 0.05
Barium 1.0
Cadf11lum 0.01
Chromium 0.05
Lead 0.05
A = Applicable
RA = Relevant and Appropriate
. All ARARs and other requirements identified apply equally to the preferred remedy (SMS) and the contingent remedy (RCRA-equlvalent closure).
1
A
AA
x
.
x
399 j 4\ararsfed
-------
..
FEDeR~LAFIAR.
R.,qulreme,.t . De$~rlp.IQ." A AA
B. Groundwater MaXimum Concentration' This requirement is included for use in the groundwater monitoring program to be
Limits (40 CFR 264.94) (continued) maintained as part of the post.closur~ care. It is not intended to define an ARAR
for groundwater remedial action because this. analysis does not address the
groundwater operable unit. The requirement is not applicable because they do
not Include hazardous waste management units; however, the requirement Is
considered well suited for use in monitoring the effectiveness of the closure
actions and is therefore considered to be relevant and appropriate.
III. Clean Air Act (CAA)
. (42 USC ?401 et seq.)
'u National Emission Standards for Hazardous
u: Air Pollutants (NESHAPs)
U A. Fugitive Emissions Sources (40 CFR This regulation controls fugitive emissions of volatile hazardous air pollutants X
W,. 61.240) (VHAP) from equipment Including: pumps, compressor pressure relief devices,
0..
U) sampling connection systems, open-ended valves or lines, valve, flanges and
-" other connectors, product accumulator vessels and control devices or systems.
iCC
0 Standards given in the regulation are for equipment that either contains. or contact
_..
~ a liquid or gas that is at least 10% by weight VHAP, defined as regulated
:1:. substances including benzene and vinyl chloride.
t).. B. Benzene Waste Operation Standards: Owners or operators of chemical manufacturing plants, coke by-product recovery X
Surface Impoundments (40 CFR 61.344) plants, petroleum refineries, or. RCRA-permltted 'hazardous .waste facilities that
treat, store, or dispose of hazardous waste (TSDFs) from these three types of
. facilities must comply with benzene emission standards If they manage a total
quantity of benzene in excess of 10 megagrams per year (11 tons/year). These
standards include general treatment and operation requirements and specific
requirements for surface Impoundments (defined as waste management units
containing liquids wastes or wastes with fre~ liquids), tanks, containers, and 011-
water separators. The surface Impoundment operation standard requires that the
unit be equipped with a cover that does not release detectable emissions as
indicated by an instrument reading less than 500 ppmv above background.
These requirements are not applicable to McColl actions b~caus.e the alternative
does not use a surface impoundment as the disposal unit.
.
A = Applicable
RA = Relevant and Appropriate
All ARARa and other requlremants identified apply equally to the preferred remedy (SMS) and the contingent remedy (RCRA-equivalent closure).
2 .
39914\arallfad .
-------
o
ii:
G
w
a.;
U).
;:l.
O'
~...
:r:
Q
U
ii:
U
ill
a.;
~
z
o.
F:;
c
o
o
~
......
o
it
2
Q;
. CI).'
z
B
c
. . ...
. . ~.q~lf~m~rit . ..
B. Benzene Waste Operation Standards:
Surface Impoundments (40 CFR 61.344)
I.
RCRA Location Standards
(40 CFR 264.18)
.... ... .. ".
.. FI;PERA~~RAa.t ... .,. ..i.. .
. d ..."'......e.... . [)e,~ripdtJ~
T: . \)qulrements are considered relevant to actions at McColl because they
regulate emissions of benzene (which Is a si. . .1:
-------
O'
u:
.Id
a.;
en.
z
o
fi
<1:"
.
. ... ..... ...
. . .. .
feDE~,,"ARAR'
..'
.. . . .
.........."'. . a,q....lr."'ftnt .
I. RCRA (continued)
" .
'P'.~rl~tIQn
A. Permitted HaZardous Waste Facilities
(40 CFR 264) (continued)
1. Groundwater Protection
(40 OFR 264.90-264.99)
There are three types of groundwater monitoring required under Subpart F:
detection monitoring, compliance monitoring and torrective action monitoring.
The groundwater monitoring program must be designed and operated to verify
that hazardous constituents have not migrated beyond the outer containment
layer prior to the end of post-closure care. The regulations are applicable to
'regulated units' which are surface impoundments, waste plies, landfills, and land
treatments units that receive hazardous wastes after July 26, 1982.
However, under RCRA, the Regional Administrator can exempt a facility under the
conditions that the unit does not contain or receive waste containing free liquid, is
designed to prevent infiltration of rainwater and groundwater, and Is an
engineered structure with inner and outer containment and leak detection. The
alternative would include either leaving or disposing treated or untreated waste in
the ground. Therefore groundwater monitoring requirements are well suited for
assuring the effective protection of the alternatives and is therefore considered
relevant and appropriate.
2. Closure and Post-Closure
(40 CFR 264.110 - 120)
Closure requires minimization of need fpr further maintenance; control;
minimization or elimination of post-closure escape of hazardous waste, hazardous
constituents, leachate, contaminated runoff, or hazardous waste decomposition
, products; and disposal or decontamination of equipment, structures, and soils.
. Closure and post-closure requirements are well-suited and thus relevant and
appropriate.
3. Land Treatment Unsaturated Zone
Monitoring (40 CFR 264.278)
Where wastes are not removed from the regulated units, and are not eventually
disposed In a RCRA-equivalent landfill, vadose zone (unsaturated zone)
monitoring requirements, that require monitoring of soil and' soil-pore liquids as
feasible to determine whether hazardous constituents are migrating, are relevant.
This requirement should be considered .appropriate to' the extent that a remedial
design can feasibly Incorporate vadose zone monitoring.
A = Applicable
RA = Relevant and Appropriate
* All ARARs and other requirements identified apply equally to the preferred remedy (SMS) and the contingent remedy (RCRA-equlvalent closure).
4
A
RA
x
x
x
J9914\8ra,sfed
-------
o
ii:
(j
W
D.
f/)
Z
o
f::
fcl. .
.
R.,qLilr~ment
4. Surface Impoundments
(40 CFR 264.220-264.228)
II. Clean Water Act (CWA)
. A. National Pollutant Discharge Elimination
System (NPDES) (40 CFR 122-125)
... . .. .. .......
... .. ...
. FEPt:RAi. AftAFi"
.
. .. ....
. .d. . ge~~tjptIQn . d
Closure with waste In place. (capping) us~s Closure and Post Closure
requirements, and elimination or solidification of free liquids; stabilization of
remaining waste and waste residues to support cover Installation of a final cover
to provide long term mlnimlzati.on of infiltration and monitoring and maintenance
for at least 30 years after closure. In addition, landfill closure and post closure
requirements are used (see immediately above).
Both on-site and off-site discharges from CERCLA sites to surface waters are
required to meet the substantive CWA NPDES requirements, including discharge
limitations, monitoring requirements, and best management practices. Only off-
site CERCLA discha~ges to surface waters must be NPDES-permitted. Stormwater
runoff from the site that is channeled to a receiving water body Is included under
this requirement.
A = Applicable
RA = Relevant and Appropriate
* All ARARs and other requirements Identified apply equally to the preferred remedy (SMS) and the contingent remedy (RCRA-equlvalent closure).
5
A
.RA
.X
x
399 I 4\818/.led
-------
u
Ii:
~.
I/)
~
u
m
:r:
9
...............
... ..
.....
... ..
I.
. .... .. . Requlr@lJ'ttnt
Hazardous Waste Control Act (HWCA)
(Health and Safety Code Section
25100-25395)
STATE "RAft,
. .. . ..~tt.c~lptio.n .
HCWA provides the state law for the management of hazardous waste Including the
state criteria for the identification of hazardous waste and standards for the design,
operation and closure of hazardous waste treatment, storage and disposal facilities.
While this program closely parallels the federal RCRA program it contains some
components with requirements in excess or more stringent than RCRA.
The Cal-EPA Department of Toxic Substance Control (DTSC) defines hazardous waste
according to any of the following criteria.
Toxicity Criteria: Toxicity of hazardous waste is established by LD50 or LC,?o criteria.
Persistent and Bloaccumulatlve Toxic Substances: Total Threshold Limit
Concentrations (TILCs) and Soluble Threshold Limit Concentrations (STLCs) have
been established to Identify hazardous waste. STLCs and TILCsare not Identified for
organics found on site. Those chemicals identified at McColl are listed below:
Chemical STLC (mall) TILC (maiko)
Arsenic 5 500
Barium 100 10,000 (excludes Ba SO,.)
Chromium (total) 560 2,500
Copper 25 2,500
Lead 5 1,000
Nickel 20 2,000
Vanadium 24 2,400
Zinc 250 5,000
Corroslvity Criteria: If, when mixed with an equivalent weight of water, a liquid is
produced which corrodes steel according to EPA test method 1110 SW-846, It is a
hazardous waste.
Extremely Hazardous Wastes: TILCs have been established for extremely hazardous
persistent and bloaccumulatlve toxic substances. TILCs for McColl waste constituents
are limited to arsenic at 50,000 mg/kg.
List of Special Wastes: These Include bag house and scrubber waste such as from
APCDs, and drilling muds from all and gas wells.
New waste management units shall have a 61 meter (200-foot) setback from any known
Holocene earthquake fault (23 CFR 2531). The location standards are relevant and
appropriate because their Intent Is to prevent the release of hazardous waste through
unusual environmental events.
A
.AA
A. Criteria for Identifying Hazardous
Waste (22CCR, 66261.1'-66261.126)
.1.
POIter-Cologne Water Quality Ad.
rNC 130()()., 13806) ~ administered by the .
Wmer Resources Control Board rNRCB)
and the Regional Water Quality Control
Board (AWQCB) (Z3 CCR 251()'2836).
x
x
A = Applicable
RA = Relevant and Appropriate
* All ARARs and other requirements Identified .apply equally to the preferred remedy (SMS) and the contingent remedy (RCRA-equlvalent closure).
6
39914\0'0'1110
-------
u
Ii:
~
IL
~
Z
o
a::
~
o
;.;;.I
u
u:
U
W
IL
fP
z:
o
.1;
CJ
C.:
I.
Requirement.
Porter-Cologne Water Quality Act
(continued)
STATE ARARs
H Q8sorlptl9"
New and existing hazardous waste management units shall be Immediately underlain
by natural geologic materials with a perme~blllty of not more than 10-7 em/see and shall
not be located where porous soil could impair the ability of natural geologic materials to
act as a barrier to vertical fluid movement. New and existing Class I units (hazardous
waste management units) shall also be located outside of floodplains subject to
inundation by floods with a 100-yr return period (23 CFR 2531). Alternatives to these
standards may be considered under certain conditions if the standard is not feasible
and the alternative is consistent with the performance goal and affords equal prot~ction
against water quality impairment. (See 23 CCR 2510 for specific conditions under
which alternatives may be considered).
These general standards include requirements for waste analyses, facility security and
inspection, training of personnel, requirements for handling ignitable, reactive or
. incompatible wastes, as well as seismic ~nd precipitation design standards. These
requirements are considered relevant and appropriate because waste is left at the site.
This article contains the requirements for the environmental monitoring of air, soli, and
water for on-site facilities that treat, store, or dispose of hazardous waste. General
requirements Include a provision for groundwater monitoring. The requirement of
environmental monitoring is considered relevant and appropriate because waste is left
at the site.
A facility shall be closed in a manner that minimizes the need for further maintenance
and controls, minimizes, or eliminates post-closure escape of hazardous waste,
leachate, contaminated rainfall, or waste. decomposition products to the ground or
surface waters or the atmosphere. Closure shall be completed within 90 days after
receiving the final volume of hazardous waste. When closure is completed, all facility
equipment and structures shall be properly disposed of, or decontaminated by
removing all hazardous waste and residues.
A = Applicable
RA = Relevant and Appropriate
All ARARa and other requirements identified apply equally to the preferred remedy (SMS) and the contingent remedy (RCRA-equivalent closure).
7 .
I.
Hazardous Waste Control Act (HWCA)
(Health and Safety Code Section
25100-25395). .
A. General Facility Standards for
Interim Status and Permitted
Facilities (22CCR 66264.10)
B. Environmental Monitoring for
Interim Status and Permitted.
Facilities (22 CCR, 66264.700)
C. Qlosure and Pc;»st-Closure for
Interim Status and Permitted
Facilities (22 CCR, 66264.110-.
66264.120)
1. Closure
A
X
RA
X
X
X
39914\8'8'0018 .
-------
o
ii.
pm:.
,cp
z
a
.~.'..
~.
..... II.
......
........../.
eJ',
.1"
.~.
z.
B
.~
. ..
. .. . p. .. Requlr~m."t..
C. Closure and Post-Closure for
Interim Status and Permitted
Facilities (continued)
2. Post Closure/Waste Left in
Place
D. Surface Impoundments, Closure
and Post Closure (22 CCR,
66264.220-66264.228)
Porter-Cologne Water Quality Act (WC
13000-13806) as administered by the
State Water Resources Control Board
(SWRCB) and the Regional Water
. Quality Control Board (RWQCB) under
CCR Title 23,. Chapter 15, 1050-2836.
A. Water Quality Monitoring for
Classified Waste Management
Units (23 CCR 2550)
.. . . . . . . ... .. .
:$TATI;ARAR$.,.'.. .. p
... :.........,. .'.... p ... ,. ... p' .... .pp. .D,~~ma)ti~".
,.
At facilities where hazardous waste will remain after closure, post-closure care shall
continue for 30.years after the date of completing closure and shall consist of at least
monitoring and reporting and malntenan~e, post-closure care and monitoring of waste
containment systems. The requirement is relevant and appropriate for the monitoring
and containments used for the untreated waste left In place and the wastes treated In
situ.
If it can be demonstrated that non liquid hazardous waste or contaminated subsoil can
remain at a closed surface Impoundment without posing a. significant hazard to water
quality, public health, or the environment, material can be left In place and closed. The
soil and soli-pore liquid should be monitored to determine whether hazardous
constituents migrate out of the treatment lone. Such monitoring would Include use of
soii cores and soli-pore liquid monitoring. Closure of a permitted surface Impoundment
Is not directly applicable to the proposed CERCLA actions at McColl; however, the
requirement for soli monitoring Is well-suited because untreated or treated waste is left
at the site.
The Porter-Cologne Water Quality Act gives the state broad statutory authority to
protect water quality by regulating waste disposal and requiring hazardous waste
cleanup. Regulations Implementing monitoring and corrective action are also
applicable to .persons responsible for discharges at waste management units which are
closed, abandoned, or Inactive on the effective date of the regulations,. meaning that
the SWRCB and the RWQCB have jurisdiction over waste disposal sites abandoned
prior to the enactment of requirements (fi 2510.(g)). Porter-Cologne delegates
standard-setting authority to the AWQCBs. Santa Ana AWQCB will not dictate specific
treatment alternatives but will require that the alternative meet minimum action levels
and perform at a level near the Best Available Technology (BAT).
This regulation requires monitoring to detect leaks from waste management units and a
corrective action program If leaks are detected. A waste management unit Is broadly
defined as an area of land where hazardous, designated, or nonhazardous waste Is
discharged. Owners and operators of new or existing landfills and surface
impoundments shall monitor groundwater, surface water and the unsaturated zone as
feasible. These requirements remain applicable through .the post-closure period.
A = Applicable
RA = Relevant and Appropriate . .
* All ARARs and other requirements Identified apply equally to the preferred remedy (SMS) and the contingent remedy (RCRA-equlvalent closure),
8
. .. p
A
RA
x
x
x
39914\ararssta
-------
o
ii:
(j
;w
a.;
CI)
z
o
.~.
<;...... /
;...
. . :;;:
. CO:::;.
......:
.' ..:::;;..
'.:!
; Requirement
B. Discharges of Waste to Land,
Construction and Operation
Requirements for Hazardous Waste
Management Units (23 CCR 2510-
2601).
... ....
. $TA11; ARAB....
. .'"
. ..; ..; :.; :.. ..D~tlcrlptlon
The Porter-Cologne Water Quality Act provides the SWRCB and the RWQCB with
specific authority to regulate hazardous waste management units Including the design,
construction, operation and closure of landfills and surface Impoundments. The
regulations distinguish between new units and units In existence before the effective
date of the regulations, but the act provides authority to regulate both new and existing
units to protect the quality of state waters. Specific requirements for hazardous waste
management units Include the following:
. New and existing landfills must be sited or oper~ted to ensure that wastes will be
a minimum of 5 feet above the highest anticipated elevation of groundwater.
. New units must be designed to withstand the maximum credible earthquake.
. Cutoff walls are required where there Is a potential for lateral movement of fluid;
the walls must be constructed a minimum of 5 feet .into natural geologic material
with a permeability of 10-7 cm/s or less.
. Landfills construction must Include a clay liner at least 2 feet thick, of 90%
relative compaction and maximum permeability of 1 x 10-7 cm/s.
. Landfills construction must Include a synthetic liner at least 40 millimeter thick.
. A blanket type leachate collection and removal system must be constructed
directly above underlying containment features for landfills and between liners for
surface impoundments.
. New and existing units must be closed with 2 feet of foundation material, 1 foot
of compacted top soil (permeability equal to the bottom liner), and the final cover
must be graded to prevent ponding or erosion.
'. Post-closure care Including monitoring, leachate collection, and cover
maintenance must continue for as long as wastes present a threat to water
quality.
These requirements are generally applicable. If treatment would render the McColl
waste nonhazardous, less stringent design standards for Class II or Class III waste
management units would be applicable.
A = Applicable.
RA = Relevant and Appropriate
* All ARARs and other requirements Identified apply equally to the preferred remedy (SMS) and the contingent remedy (RCRA-equivalent closure). .
9
A
X
RA
39914\8'8,."8
-------
0'.
it
.5t
0;;'
,n,.
z
o
~.
,.
::7. ' ." Aequir'me~t .
III. South Coast Air Quality Management
District (SCAQMD) Rules and
Regulation~
'.:
A. Regulation IV--Prohlbltory Rules
.STAte.AMRet:/'...."'... ..,
. . .. .., ,< ."" . '. ..... .... iQ'8.;rlpJ'Qn . ' . .
The South Coast Air Quality Management District has authority to implement the federal
and state air quality management programs through the State Implementation Plan and
the Rules and Regulations to comply with the Nonattalnment Area Plan for the South
Coast Air Basin. In general, SCAQMD Rules and Regulation are applicable t~ all
actions at McColl; however, specific emission control requirements may have limited
application to specific source units.
.,
limits visible emissions from any point source to Rlngelmann No.1 or 20 percent
opacity for 3 minutes In any hour.
Prohibits the discharge of any material (Including odorous compounds) that causes
Injury, or annoyance to the public, property, or businesses or endangers human health,
comfort, repose, or safety.
This regulation limits on-site activities so that the concentrations of fugitive dust at the
property line shall not be visible and the downwind particulate concentration shall not
be more than 100 micrograms per cubic meter, averaged over 5, hours, above the,
upwind particulate concentration. These requirements do not apply if the wind speed,
averaged over 15 minutes, Is above 15 miles per hour. The rule also requires every
reasonable precaution to minimize fugitive dust and the prevention and cleanup of any
mate,rial accidently deposited on paved streets.
Rule 404(a) limits particulate emissions for given volumetric gas flow rates. '
,
This rule establishes allowable discharges for particulates at rates Of 0.99 to 30 Ib/hr.
This rule limits carbon monoxide emissions to 2000 ppm and sulfur dioxide emissions
t
-------
(.)
i!;
o
W
Go
",
Z
o
~
1<
.
.R.q~lre"'.frt .
B. Regulation X--National Emission
Standards for Hazardous Air
Pollutants
III. . South Coast Air Quality Management
District (SCAQMD) ~ules and
Regulations (continued)
C. Regulation XI--Source Specific
Standards
Rule 1150 Excavation of Land/ill
Sites
Rule 1150.2 Control of Gaseous
Emissions
Rule 1166 Organic Gas Emissions
from Decontamination of Soli
.,.. '.
. ......
...$TATE..A8AR$
.'.' . ,.... .'. "..i .' p..cr'Ptlon
Implements the provisions .of Part 61, Chapter " Title 40, of the CFR under the
supervision of SCAQMD Executive Officer. The only NESHAP standard that would
serve as an ARAR for the McColl site Is "Benzene Waste Operation Standards for
Surface Impoundments" (40 CFR 61.344). A cover for a surface Impoundment should
be designed to operate with no detectable emissions as Indicated by an instrument
reading of less that 500 ppm above background. The provisions apply to hazardous
waste facilities that use surface Impoundments to 'treat, store, or dispose of hazardous
wastes from petroleum refineries.
This rule states that no person shall Initiate excavation of an active or Inactive landfill
without an Excavation Management Plan. The plan shall provide Information regarding
the quantity and characteristics of the material to be excavated and transported and
shall Identify mitigation measures Including gas collection and disposal, baling,
encapsulation, covering of the material, and chemical neutralizing.
The rule limits gaseous emissions from Inactive land/ills. Within this rule, an inactive
landlill Is defined as a site where refuse had been disposed before 1982. Total Organic
Carbon (TOC) emissions are limited to 500 ppm measured as methane (CH,J at any
point on the surface of the landlill and to 50 ppm measured as total organic
compounds over a surface area of the land/ill. This requirement Is not strictly
applicable to the - McColl site because the McColl wastes do not fit the accepted
definition of refuse. However, the requirement Is relevant and appropriate because the
Intent Is to protect air quality by limiting emissions of organic compounds from a
disposal site.
This rule limits the emissions of volatile organic compounds (VOCs) from contaminated
soli. The rule prohibits anyon-site or off-site spreading of VOC- contaminated soil
which results In uncontrolled evaporation of VOC to the atmosphere. Rule
1166(c)(2)(B) requires that a person treating or handling VOC-contaminated soil
implement BACT mitigation measures approved by the SCAQMD Executive Officer.
There Is an exemption for emergency soil excavation performed under the jurisdiction of
an authorized health officer.
A = Applicable
RA = Relevant and Appropriate
* All ARARs and other requirements identified apply equally to the preferred remedy (SMS) and the contingent remedy (RCRA.equlvalent closure).
11
A
~~.'
X
x
x
x
39914\8.....1.
-------
.'
.} ....'. .R"q",'r~m..ot ..
D. Regulation XIII--New Source Review
~'..
II;.
~.,..
CL
cp
z
5
c
E. Regulation XIV-Toxlcs
I...": .
.: .".
. .
. .. ........... '"
.. $TATEARARI.' ."" . . . "H. .
" H .". .,..,,:,}. .".. .'. Q"Qr~Ptlq" . ... .
This regulation sets forth preconstructlon review requirements for new, modified, or
relocated facilities to ensure that the operation of such stationary sources does not
Interfere with progress In attainment of the national and state ambient air quality
standards without unnecessarily restricting the future economic growth within the
district. These requirements apply to new or modified permit units, meaning articles,
machinery, equipment, contrivances, or any combination of the above, which causes
the iss\Jance of nonattalnment air .contaminants or halogenated hydrocarbons at the
site. Included in these permit units are emission control equipment.
Rule 1303 requirements mandate Best Available Control technology (BACT) and
requires modelling to demonstrate that any new or modified facility will not cause a
violation of NMOS standards. BACT guidelines are available for commonly processed
permit units. BACT for other permit units is determined on a case-by-case basis.
Modeling for sulfur oxides, as primary contaminants, and reactive organic gases Is not
presently required. The rule also states that accumulated emissions can be offset by
reduction credits or credits from Community Bank.
Rule 1306 provides that emissions calculations are to be used as the basis for
calculating applicability of Regulation XIII.' These requirements are considered
. applicable to all alternatives, except the "no action" alternative, to the extent that the
alternatives employ equipment which either cause or . control the Issuance of
nonattalnment air contaminants.
. . Rule 1401 - New Source Review of Carcinogenic Air Contaminants specifies limits for
cancer risk and excess cancer cases from new, modified, and relocated permit uf,llts
that emit carcinogenic air contaminants. The rule establishes allowable emission
Imp-acts for all such permit units requiring new permits pursuant to SCAOMD Rules 201
or 203. Best Available Control Technology for Toxlcs (T-BACT) will be required for any
system where a lifetime (70 year) maximum Individual cancer risk of one in one million
or greater Is estimated to occur. Limits are calculated using unit risk factors for specific
contaminants. Contaminants identified at the .McColi site (Table 1-3) that have
Identified unit risk factors Include: arsenic, benzene, cadmium, chromium methylene
chloride, and possibly phenols. .
A = Applicable
RA = Relevant and Appropriate
All ARARa and other requirements Identified apply equally to the preferred remedy (SMS) and the contingent rem'edy (RCRA-equlvalent closure).
12 .
A
X
RA
X
39914Ia,a,..'a .
------- |