United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R09-93/092
June 1993
v°/EPA Superfund
Record of Decision:
San Fernando Valley Area 2
(Operable Unit 2), CA
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50272-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/ROD/RO9-93/0 92
3. Recipient's Accession No.
4. THIe and Subtitle
SUPERFUND RECORD OF DECISION
San Fernando Valley Area 2 (Operable Unit 2), CA
Third Remedial Action
5. Report Date
06/18/93
6.
7. Author(s)
8. Performing Organization Rapt. No.
9. Performing Organization Name and Address
10 Pro|ect Taskwork Unit No.
1 1 . Contraet(C) or Grant(G) No.
(0)
12. Sponsoring Organization Name and Address
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
13. Type of Rsport & Period Covered
800/800
14.
15. Supplsmsntary Notes
PB94-964527
16. Abstract (LlmH: 200 words)
The San Fernando Valley Area 2 (Operable Unit 2) site is part of the Crystal Springs
NPL Site, which is one of four San Fernando Valley Superfund sites in Los Angeles
County, California. Land use in the area is mixed industrial, commercial, and
residential. The 122,800-acre Glendale Study Area is located within the San Fernando
Basin, is adjacent to the Los Angeles River, and consists of the North Plume and the
South Plume, which are two main portions of the aquifer in the San Fernando Basin where
high concentrations of contaminants have been identified. An estimated 800,000
residents use the ground water of the San Fernando Basin as a significant source of
their drinking water supply. In 1980, after finding organic chemical contamination in
the ground water of the San Gabriel Valley, the State ordered all major water purveyors
in the San Fernando Valley using ground water to conduct tests for the presence of
certain industrial chemicals. Initial and subsequent testing revealed the presence of
VOCs in the San Fernando Valley ground water. As a result, several municipal supply
wells were taken out of service in Los Angeles, Burbank, and Glendale. By 1986, four
sites within the San Fernando Valley had been added to the NPL; the North Hollywood,
Crystal Springs, Verdugo, and Pollock sites, also referred to as San Fernando Valley
(See Attached Page)
17. Document Analysis a. Descriptors
Record of Decision - San Fernando Valley Area 2 (Operable Unit 2), CA
Third Remedial Action
Contaminated Medium: gw
Key Contaminants: VOCs (benzene, PCE, TCE), other organics (PAHs), inorganics
(nitrates)
b. Identifiers/Open-Ended Terms
e. COSATI Field/Group
19. Security Class (This Rsport)
None
20. Security Class (This Page)
None .
21. No. of Pages
64
22. Pries
(SeeANSI-Z39.18)
Seo Instructions on Reverse
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-35)
Department of Commerce
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EPA/ROD/R09-93/092
San Fernando Valley Area 2 (Operable Unit 2), CA
Third Remedial Action
Abstract (Continued)
Areas 1, 2, 3, and 4, respectively. EPA has preliminarily identified twenty-two facilities
that are located in the vicinity of the Glendale Study Area (North Plume) and that are
potentially responsible for the ground water contamination. 1987 and 1989 RODs addressed
interim remedies for contaminated ground water at the North Hollywood site and the Burbank
site, respectively. This ROD addresses an interim remedy for the Glendale North Study
Area, which includes the VOC contamination of the North Plume and adjacent areas where
contamination is known or believed to have migrated, as OU2. Another 1993 ROD addresses
the Glendale South Study Area, as OU3. Future RODs will address additional OUs and a
final remedy for the San Fernando Valley Areas 1, 2, 3, and 4. The primary contaminants
of concern affecting the ground water are VOCs, including benzene, PCE, and TCE; other
organics, including PAHs; and inorganics, including nitrates.
The selected interim remedial action for this site includes installing new extraction
wells to most effectively inhibit the migration of the contaminant plume and maximize the
extraction of the most contaminated ground water; extracting approximately 3,000 gpm of
the contaminated ground water; filtering the extracted ground water to remove suspended
solids, if necessary, followed by onsite treatment to remove VOCs using single-stage or
dual-stage air stripping or liquid phase granular activated carbon (GAC); using
vapor-phase GAC adsorption for emissions control, if air stripping is used; blending the
VOC-treated water offsite with water that does not contain nitrate in excess of the
nitrate MCL to reduce nitrate levels, followed by delivering the water to the Glendale
public drinking water supply system or another municipal system; abandoning or
rehabilitating existing production wells in the area, if required; providing for a
contingency remedy with no blending for nitrate reduction and reinjection into the aquifer
for the treated ground water, if the City of Glendale or another municipality does not
accept any or all of the treated water; and establishing ground water monitoring wells to
evaluate the effectiveness of the interim remedy. In order to decrease cost, treatment
and delivery of treated water for the Glendale North and Glendale South OUs will be
combined. Ground water monitoring wells also will be established to evaluate the
effectiveness of the interim remedy. The estimated present worth cost for this interim
remedial action is $36,400,000, which includes an annual O&M cost of $3,240,000 for 12
years. If the treatment plants for the Glendale North and South Plumes are combined as
planned, the estimated present worth cost for both would be $47,532,000.
PERFORMANCE STANDARDS OR GOALS:
Chemical-specific cleanup goals for the treatment plant effluent from the Glendale North
OU are based on the more stringent of Federal and State MCLs for VOCs, and include benzene
1 ug/1; bis(2-ethylhexyl)phthalate 4 ug/1; carbon tetrachloride 0.5 ug/1; 1,1-DCA 5 ug/1;
1,2-DCA 0.5 ug/1; 1,1-DCE 6 ug/1; 1,2-DCE 6 ug/1; 1,1,2,2-PCE 1 ug/1; PCE 5 ug/1; and TCE
5 ug/1.
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GLENDALE NORTH OPERABLE UNIT
RECORD OF DECISION
PART I: DECLARATION
PART II: DECISION SUMMARY
PART III: RESPONSIVENESS SUMMARY
SAN FERNANDO VALLEY AREA 2 SUPERFUKD SITE
LOS ANGELES COUNTY, CALIFORNIA
United States Environmental Protection Agency
Region 9 - San Francisco, California
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TABLE OF CONTENTS
Page No.
Part I. Declaration 1
Part II. Decision Summary 4
1.0 Site Location and Description 4
2.0 Site History 5
3.0 Enforcement Activities 8
4.0 Highlights of Community Participation 9
5.0 Scope and Role of the Operable Unit 10
6.0 Summary of Glendale North OU Site
Characteristics 11
7.0 Summary of Site Risks 13
8.0 Description of Alternatives 18
9.0 Summary of Comparative Analysis
of Alternatives 24
10.0 Applicable or Relevant and Appropriate
Requirements 30
11.0 The Selected Remedy 39
12.0 Statutory Determinations 43
13.0 Documentation of Significant Changes 44
Part III. Responsiveness Summary 45
Executive Summary 45
Part I - Responses to Comments from the Local
Community (including the City
of Glendale)
Part II - Responses to Legal and Technical
Comments (including those of the State
of California)
Appendix A - San Fernando Valley Information Respositories
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RECORD OF DECISION
GLENDALE NORTH OPERABLE UNIT INTERIM REMEDY
PART I. DECLARATION
SITE NAME AND LOCATION
San Fernando Valley Area 2
Glendale North Operable Unit
Los Angeles County, California
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action
for the Glendale North Operable Unit, San Fernando Valley Area 2
Superfund site, chosen in accordance with, CERCLA as amended by SARA
and, to the extent practicable, the National Contingency Plan.
This decision is based on the Administrative Record for this
operable unit.
In a letter to EPA dated March 29, 1993, the State of
California agreed with the selected remedy for the Glendale North
OU.
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.
DESCRIPTION OF THE REMEDY
EPA has selected an interim remedy for the North plume of
groundwater contamination in the Glendale Study Area. This interim
remedy is referred to as the Glendale North Operable Unit (OU). An
OU is a discrete action that comprises an incremental step toward
comprehensively addressing Superfund site problems. The remedy-and
all of the alternatives presented in the feasibility study were
developed to meet the following specific cleanup objectives for the
Glendale North OU:
o To inhibit vertical and horizontal migration of
groundwater contamination in the North Plume of the
Glendale Study Area; and
o To begin to remove contaminant mass from the upper zone
of the aquifer in the North Plume of the Glendale Study
Area.
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The remedy involves groundwater extraction and treatment for
the shallow aquifer system in the Glendale area of the San Fernando
Valley.-^ Under this remedy, -contaminated groundwater would be
extracted at a rate of 3,000 gallons per minute (gpm) for 12 years
from new wells to be installed in the Glendale Study Area. The
extracted contaminated groundwater will be filtered to remove any
suspended solids, if necessary, and then treated by air stripping
(single or dual-stage) and/or liquid phase granular activated
carbon (GAC) to remove volatile organic compounds (VOCs). After
treatment, the water shall meet drinking water standards (maximum
contaminant levels or MCLs) for VOCs. If air stripping treatment
is selected, air emissions will be treated using vapor phase GAC to
ensure that all air emissions meet applicable or relevant and
appropriate requirements. The exact number, location and other
design specifics of these new extraction wells and air
stripping/liquid phase GAC units will be determined during the
remedial design phase of the project. After treatment to remove
VOCs, to meet the nitrate MCL, the water will be blended with an
alternative water of a quality such that the resulting water
treated, blended water will meet all drinking water MCLs. All or
part of the extracted treated water will then be conveyed to the
City of Glendale or another San Fernando Valley water purveyor for
distribution through its public water supply system.
As a result of comments by the City of Glendale on the
Glendale North OU Proposed Plan (July 1992) and Glendale South OU
Proposed Plan (September 1992) which indicated that the City had
sufficient water credits to accept the treated water from both the
Glendale North and Glendale South OUs, and in order to decrease
overall costs associated with the OUs, EPA has determined that the
treatment plants for the Glendale North and Glendale South OUs will
be combined. The total 5,000 gpm of treated water will be conveyed
to the City of Glendale for distribution to its public water supply
system. The exact configuration of the combined treatment plant
will be determined during the remedial design phase of the project.
The Glendale South OU Record of Decision will also reflect this
decision to combine the treatment plants.
However, if the City of Glendale does not agree to accept the
treated water from both OUs or if EPA determines that combining the
treatment plants will significantly delay or hinder the
implementation of the Glendale North OU, the treatment plants will
not be combined. Furthermore, if the City of Glendale does not
accept any or all of the treated water (possibly due to water
supply needs), any remaining portion of the water will be 1)
offered to another San Fernando Valley water purveyor or 2)
reinjected into the aquifer.
The total duration of the Glendale North OU interim remedy
will be 12 years. EPA will determine the need for and scope of any
further actions every five years throughout this interim remedy
period and again at the conclusion of this period.
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The remedial action for the Glendale North OU represents a
discrete element in the overall long-term remediation of
groundwater in the eastern portion of the San Fernando Valley. The
objectives of this interim action; inhibition of migration and
restoration of groundwater quality to meet drinking water standards
for VOCs to the extent practicable, would not be inconsistent with
nor preclude implementation of any final, overall remedial action
or actions selected by EPA in the future for the San Fernando
Valley Areas l, 2, 3 and 4.
EPA is the lead agency for this project and the Department of
Toxic Substances Control of the state of California Environmental
Protection Agency Department of Toxic Substances Control (DTSC) is
the support agency.
DECLARATION
This interim action is protective of human health and the
environment, complies with Federal and State applicable or relevant
and appropriate requirements directly associated with this action
and is cost effective. This action utilizes permanent solutions
and alternative treatment (or resource recovery) technologies to
the maximum extent practicable, given the limited scope of the
action. Because this action does not constitute the final remedy
for the site, the statutory preference for remedies that employ
treatment that reduces toxicity, mobility, or volume as a principal
element will be addressed at the time of the final response action.
Subsequent actions are planned to fully address the principal
threats at these sites.
Because this remedy will result in hazardous substances
remaining on-site above health-based levels, EPA shall conduct a
review, pursuant to CERCLA Section 121, 42 U.S.C. Section 9621, at
least once every five years after commencement of remedial action
to ensure that the remedy continues to provide adequate protection
of human health and the environment.
^f-Q'KA
mjz. Wise
C . co
Johajz. Wise Date
Acting Regional Administrator
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'^ PART II. DECISION SUMMARY
This Decision Summary provides an overview of the Glendale
North OU interim remedy, including the nature and extent of
contamination to be addressed, a description of the remedial
alternatives, the comparative analysis of the remedial
alternatives, a description of the selected remedy and the
rationale for remedy selection
1.0 SITE LOCATION AND DESCRIPTION
The Glendale Study Area is located within the San Fernando
Basin. The following sections present a basin description,
regulatory history, and a summary of the Remedial Investigation and
Feasibility Study (RI/FS) activities within the San Fernando Valley
and the Glendale Study Area.
1.1 Description of the San Fernando Basin
The San Fernando Basin is located within the Upper Los Angeles
River Area (ULARA), which consists of the entire watershed of the
Los Angeles River and its various tributaries. The San Fernando
Basin covers approximately 122,800 acres and comprises 91.2 percent
of the ULARA alluvial fill. It is bounded on the north and
northwest by the Santa Susana Mountains, on the northeast by the
San Gabriel Mountains, on the west by the Simi Hills, and on the
south by the Santa Monica Mountains.
The San Fernando Basin is a significant source of drinking
water, with an estimated total volume of 3 million acre-feet of
groundwater stored in aquifers within the alluvial fill of the
basin. The groundwater of the San Fernando Basin has been used as
a source of drinking water for more than 800,000 residents within
the cities of Los Angeles, Burbank, Glendale, and San Fernando.
Groundwater extractions within the San Fernando Basin typically
provide 15 percent of Los Angeles' annual average water supply and
historically have accounted for between 50 and 100 percent of the
water needs of the other cities.
1.2 Description and Background of the Glendale Study Area
The Glendale Study Area is in the vicinity of the Crystal
Springs National Priorities List (NPL) Site, one of the four San
Fernando Valley Superfund NPL sites, and is adjacent to the Los
Angeles River (Figure 1). The Glendale Study Area includes two
portions of the aquifer where high concentrations of contaminants
have been identified: the North Plume and the South Plume (Figure
2). Although contamination has been detected throughout the
Glendale Study Area in an apparently contiguous plume, differences
exist between the North Plume and South Plume, including the types
of contaminants detected and the concentrations of the
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^AN^FERNANDO VALL EY SUPERFUND SITE
San Gabriel Mountains
iWVERDUGO
NPL
X«i.'-!?«i^. SITE
Verdugo Mountains ^i^v
NORTH
HOLLYWOOD
NPL SITE -*
Glendale
Study Area
CRYSTAL
SPRINGS
NPL SITE
Santa Monica
Mountains
POLLOCK
NPL SITE
GLENDALE
GROUNDWATER
BASIN BOUNDARY
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NORTH OU
HEADWORKS
SPREADING
GROUNDS
TCE CONCENTRATION IN GROUNDWATER
POTENTIALLY EXCEEDING 5000 ug/l
TCE CONCENTRATION IN GROUNDWATER
POTENTIALLY RANGING FROM 500 ug/l TO 5000 ug/l
TCE CONCENTRATION IN GROUNDWATER
POTENTIALLY RANGING FROM 100 ug/l TO 500 ug/l
TCE CONCENTRATION IN GROUNDWATER
POTENTIALLY RANGING FROM 50 ug/l TO 100 ug/l
TCE CONCENTRATION IN GROUNDWATER
POTENTIALLY RANGING FROM 5 ug/l (MCL) TO 50 ug/l
FIGURE 2: AREAS OF CURRENTLY
KNOWN TCE CONTAMINATION
IN THE GLENDALE STUDY AREA
QLENDALE STUDV AREA REMEDIAL INVESTIGATION
0 2000
I
SCALE IN FEET
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contaminants. The Glendale North and South Plumes are separated by
an area of lower-level groundwater contamination. The Glendale
North OU includes the North Plume of VOC contamination and adjacent
areas where contamination is known or believed to have migrated.
In 1990, an analysis was performed to evaluate the need for an
OU within the Crystal Springs NPL site (CH2M Hill, 1990). This
analysis included a qualitative comparison based on known
groundwater contamination, potential downgradient impacts and water
supply. This analysis concluded that there was a need for an OU
within the Crystal Springs NPL site because: 1) high
concentrations of TCE and PCE were present in groundwater, 2) the
critical loss of groundwater production in the Glendale area and 3)
the potential for contaminating groundwater downgradient from the
Crystal Springs NPL site. Additional data collection was
recommended to more adequately characterize the horizontal and
vertical distribution of contamination in the aquifer, and also to
improve the definition of the hydrogeology of the area.
EPA conducted a remedial investigation (RI) that
characterized the nature and extent of contamination in the
Glendale-Study Area. Upon completion of the Remedial Investigation
Report for the Glendale Study Area (January 1992), a feasibility
study (FS) was undertaken for the Glendale North OU which evaluated
a range of cleanup alternatives for addressing the contaminated
groundwater. The FS report entitled Feasibility Study for the
Glendale Study Area North Plume Operable Unit was completed in
April 1992.
2.0 SITE HISTORY
In 1980, after finding organic chemical contamination in the
groundwater of the San Gabriel Valley, the California Department of
Health Services (DHS) requested that all major water purveyors in
the San Fernando Valley using groundwater conduct tests for the
presence of certain industrial chemicals in the water they were
serving. The results of initial tests and of subsequent testing
revealed the presence of volatile organic compound (VOC)
contamination in the groundwater of the San Fernando Valley.
These findings resulted in a number of municipal supply wells for
the cities of Los Angeles, Burbank, and Glendale being taken out of
service. The primary contaminants of concern were and are the
solvents trichloroethylene (TCE) and perchloroethylene (PCE),
widely used in a variety of industries including metal plating,
machinery degreasing and dry cleaning.
In 1984, EPA proposed four sites within the San Fernando
Valley for inclusion on the NPL and in 1986 the sites were added to
the list (Figure 3). Each site boundary encompasses an area in
which production wells produced groundwater containing
concentrations of TCE and PCE above State and Federal standards in
1984. The four NPL sites in the San Fernando Valley are the North
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contaminants. The Glendale North and South Plumes are separated by
an area of lower-level groundwater contamination. The Glendale
North OU includes the North Plume of VOC contamination and adjacent
areas where contamination is known or believed to have migrated.
In 1990, an analysis was performed to evaluate the need for an
OU within the Crystal Springs NPL site (CH2M Hill, 1990). This
analysis included a qualitative comparison based on known
groundwater contamination, potential downgradient impacts and water
supply. This analysis concluded that there was a need for an OU
within the Crystal Springs NPL site because: 1) high
concentrations of TCE and PCE were present in groundwater, 2) the
critical loss of groundwater production in the Glendale area and 3)
the potential for contaminating groundwater downgradient from the
Crystal Springs NPL site. Additional data collection was
recommended to more adequately characterize the horizontal and
vertical distribution of contamination in the aquifer, and also to
improve the definition of the hydrogeology of the area.
EPA conducted a remedial investigation (RI) that
characterized the nature and extent of contamination in the
Glendale' Study Area. Upon completion of the Remedial Investigation
Report for the Glendale Study Area (January 1992), a feasibility
study (FS) was undertaken for the Glendale North OU which evaluated
a range of cleanup alternatives for addressing the contaminated
groundwater. The FS report entitled Feasibility Study for the
Glendale Study Area North Plume Operable Unit was completed in
April 1992.
2.0 SITE HISTORY
In 1980, after finding organic chemical contamination in the
groundwater of the San Gabriel Valley, the California Department of
Health Services (DHS) requested that all major water purveyors in
the San Fernando Valley using groundwater conduct tests for the
presence of certain industrial chemicals in the water they were
serving. The results of initial tests and of subsequent testing
revealed the presence of volatile organic compound (VOC)
contamination in the groundwater of the San Fernando Valley.
These findings resulted in a number of municipal supply wells for
the cities of Los Angeles, Burbank, and Glendale being taken out of
service. The primary contaminants of concern were and are the
solvents trichloroethylene (TCE) and perchloroethylene (PCE),
widely used in a variety of industries including metal plating,
machinery degreasing and dry cleaning.
In 1984, EPA proposed four sites within the San Fernando
Valley for inclusion on the NPL and in 1986 the sites were added to
the list (Figure 3). Each site boundary encompasses an area in
which production wells produced groundwater containing
concentrations of TCE and PCE above State and Federal standards in
1984. The four NPL sites in the San Fernando Valley are the North
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SAN FERNANDO
VALLEY
NORTH
HOLLYWOOD
NPL SITE
SANTA UONI
MOUNTAIN
SAN FERNANDO VALLEY STUDY AREA.
INCLUDING THE FOUR NATIONAL
PRIORITIES LIST (NPL) SITES
CLENDAIE STUDY AREA
FIGURE 3
SITE LOCATION MAP
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Hollywood, Crystal Springs, Verdugo, and Pollock sites, also
referred to as San Fernando Valley Areas l, 2, 3, and 4,
respectively. EPA is managing the four sites as one large site.
The San Fernando Valley Study Area includes the four sites as
listed on the NPL and adjacent areas where contamination has or may
have migrated. A basinwide groundwater RI report for the San
Fernando Valley Study Area was completed in December 1992.
Groundwater wells installed by EPA as part of the basinwide
groundwater RI are routinely sampled to continue to monitor the
nature and extent of the groundwater contamination in the San
Fernando Valley.
EPA has previously signed Record of Decision (ROD) documents
for two OUs in the San Fernando Valley: the North Hollywood OU
(1987) and the Burbank OU (1989). The North Hollywood OU interim
remedy is currently operating and the Burbank OU is in the remedial
design phase. In the Glendale Study Area, EPA has identified two
OUs: the Glendale North Plume OU and the Glendale South Plume OU.
In addition, EPA has recently initiated an RI/FS for an OU in the
Pollock area of the San Fernando Valley. All of these OUs
represent interim cleanups currently in progress throughout the
eastern portion of the San Fernando Valley. All remedial actions
established by EPA thus far in the Record of Decision for each OU
have been interim measures. EPA has not yet selected a final
remedy for the entire San Fernando Valley.
TCE and PCE have been detected in the majority of the City of
Glendale's wells at levels that are above the Federal Maximum
Contaminant Level (MCL), which is 5 parts per billion (ppb) for
each of these VOCs. The State of California MCL is also 5 ppb for
both TCE and PCE. Other VOC contaminants have been detected above
State and/or Federal MCLs in the Glendale area. As a result of the
groundwater contamination, the majority of the City of Glendale's
wells have been taken out of service. The most prevalent
contaminants are TCE and PCE. In 1992, the highest concentrations
of TCE and PCE detected in EPA monitoring wells in the San Fernando
Valley were 7100 ppb and 160 ppb, respectively. Groundwater
samples from wells installed at industrial facilities in the San
Fernando Valley near potential sources of contamination have shown
concentrations greater than 30,000 ppb for TCE and over 15,000 ppb
for PCE. The maximum of 30,000 ppb for TCE was detected in a
facility well located in the north plume portion of the Glendale
Study Area.
Nitrate, an inorganic contaminant, has been detected
consistently at levels in excess of the MCL (45 mg/1 as nitrate or
10 mg/1 nitrate as nitrogen) in the groundwater of the Glendale
Study Area. The nitrate contamination is likely to be the result
of past agricultural practices and/or septic systems in the San
Fernando Valley.
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It* should be noted that the City of Glendale closely monitors
the quality of drinking water delivered to residents. The water
the City serves to its residents must meet all Federal and State
drinking water requirements. Currently, nearly all of the water
delivered by the City of Glendale is purchased from the
Metropolitan Water District (MWD) of Southern California. The City
uses a limited amount of groundwater from a small percentage of its
nine production wells in the San Fernando Valley. .If the levels of
VOCs and other contaminants detected in the groundwater of
production wells are equal to or less than 10 times MCLs, the State
of California Department of Health Services, Office of Drinking
Water permits the City to extract the water, blend it with MWD
water to meet all drinking water standards, and convey the
extracted, blended water to its public distribution system.
As described briefly in Section 1 above, the Glendale Study
Area includes two portions of the aquifer .where high concentrations
of contaminants have been identified: the north plume and the south
plume. A remedial investigation (RI) that characterized the nature
and extent of contamination in the Glendale Study Area was
completed in (January 1992). The Glendale Study Area RI included
a characterization of the nature and extent of contamination,
baseline risk assessments, and other RI data for both the north and
south plumes. However, separate FS reports evaluating a range of
cleanup alternatives for the contaminated groundwater were prepared
for each plume. The Glendale North OU FS report and subsequent
Proposed Plan were finalized in April 1992 and July 1992,
respectively. The Glendale South OU FS report was completed in
August 1992 and the Proposed Plan was completed in September 1992.
EPA's preferred alternatives as described in the Proposed
Plans were: extraction of 3000 gallons per minute (gpm) of
contaminated groundwater for Glendale North and 2000 gpm for
Glendale South, treatment of VOCs by air stripping or liquid phase
GAC, and conveyance of the treated water to a water purveyor, where
it would be blended with water of a quality such that the treated,
blended water would meet all drinking water standards, for eventual
distribution through a public water system. As a contingency, if
all or part of the treated water was not accepted by the purveyors
(possibly due to water supply needs), the treated water from
Glendale North would be reinjected and for Glendale South would be
recharged at the Headworks Spreading Grounds (see Figure 1-2).
In response to comments by the City of Glendale on the
Glendale North and South OU Proposed Plans and in order to decrease
overall costs associated with the OUs, EPA has determined that the
treatment plants for the Glendale North and Glendale South OUs will
be combined and the total 5,000 gpm of treated water will be
conveyed to the City of Glendale for distribution to its public
water supply system. The exact configuration of the combined
treatment plant will be determined during the remedial design phase
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of the--^>roject. The Glendale South OU Record of Decision also
reflects this decision to combine the treatment plants.
However, if the City of Glendale does not agree to accept the
treated water from both OUs or if EPA determines that combining the
treatment plants will significantly delay or hinder the
implementation of the Glendale North OU, the treatment plants will
not be combined and only the extracted treated water from the
Glendale North OU will be conveyed to the City of Glendale for
distribution to its public water supply system. As a further
contingency, if the City of Glendale does not accept any or all of
the treated water (possibly due to water supply needs), any
remaining portion of water will be 1) offered to another San
Fernando Valley water purveyor or 2) reinjected/recharged into the
aquifer.
3.0 ENFORCEMENT ACTIVITIES
In September 1989, EPA signed a cooperative agreement with the
State Water Resources Control Board (SWRCB) providing funds for the
Regional Water Quality Control Board, Los Angeles Region (RWQCB) to
expand its capability to conduct source reduction, identification,
and enforcement activities at individual facilities in the San
Fernando Valley. Activities include conducting surveys and inspec-
tions, and overseeing investigations and remedial activities. The
cooperative agreement has been renewed annually since 1989. If
RWQCB investigations confirm soil or groundwater contamination at
a specific facility, then that facility is referred to EPA. EPA is
using the RWQCB's facility specific information in conjunction with
RI data, groundwater and vadose zone modeling results and
information gathered from other sources including California
Environmental Protection Agency (CAL-EPA) investigations, South
Coast Air Quality Management District (SCAQMD) investigations and
responses to information request letters, to build enforcement
cases.
EPA is and will be using its investigatory resources,
enforcement resources and authority under CERCLA in conjunction
with the work of the Los Angeles Region (Region 4) of the RWQCB to:
o Identify individuals and companies who are responsible
for the historic and current contamination.
o Compel responsible parties to design, construct and
operate treatment facilities and reimburse EPA for prior
and any future expenditures at the site.
EPA issued preliminary notices of potential liability
(General Notice) for the Glendale North OU to 35 parties on August
27, 1992 and to two additional parties on August 31, 1992. The
list of General Notice parties was updated in February 1993 when
one owner was deleted and three others added. These parties have
8
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been preliminarily identified as owners and operators of 22
facilities located in the vicinity of the north plume portion of
groundwater contamination in the Glendale Study Area of the San
Fernando Valley. EPA anticipates that additional parties will be
notified of potential liability. Special notice pursuant to CERCLA
§122 has not yet been issued for the Glendale North OU.
4.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION
EPA's preferred alternative, as well as six other alternatives
.were described in EPA's Proposed Plan for the Glendale North OU
(July 1992). The Proposed Plan was in the form of a fact sheet and
was distributed to 'all parties on EPA's mailing list for the San
Fernando Valley Superfund sites. The original 30 day public
comment period was extended an additional 30 days after EPA
received requests for extensions from members of the public. The
public comment period closed on September 8, 1992. EPA received
over 150 comments. These comments and EPA's responses to these
comments are summarized in Part III (the Responsiveness Summary) of
this ROD.
A public meeting was held in the City of Glendale on July 23,
1992, to discuss EPA's preferred alternative and the other
alternatives. At this meeting EPA gave a brief presentation
regarding the Proposed Plan, answered questions, and accepted
comments from members of the public.
At the public meeting and in a subsequent letter, the City of
Glendale emphasized that it would like to receive greater than
3,000 gpm of extracted, treated groundwater. The City also
indicated that it had stored water credits and water rights
sufficient to accept greater than 5,000 gpm of extracted, treated
groundwater from the San Fernando Valley. As a result of the
City's oral and written comments on the Glendale North OU, EPA has
determined that the treatment plants for the Glendale North and
South OUs will be combined and the total 5,000 gpm of treated water
will be conveyed to the City of Glendale.
Notice of the public meeting as well as the availability of
the Proposed Plan was published in the Los Angeles Daily News on
July 8, 1992. In addition, several newspaper articles were written
about the remedial investigation, the feasibility study and the
Proposed Plan for the Glendale North OU including: Los Angeles
Times - June 19, 1992; Los Angeles Daily News - June 19, 1992; Los
Angeles Times - July 23, 1992; Los Angeles Daily News - July 24,
1992 and the Glendale News Press - July 24, 1992. A map of the
Glendale North OU was provided in the Proposed Plan and the various
newspaper articles described the area that would be impacted by the
Glendale North OU.
Prior to mailing out the Proposed Plan fact sheet and
conducting the public meeting for the Glendale North OU, EPA
-------
conducted an outreach program specifically aimed at the Glendale
community. EPA placed inserts describing the proposed interim
cleanup of groundwater in the Glendale area in utility bills
delivered to over 127,000 community members. The insert not only
explained the project but offered an opportunity to be added to
EPA's mailing list for the San Fernando Valley project by filling
out and returning an attached coupon. As a result of this utility
bill insert project, EPA was able to double its mailing list for
the San Fernando Valley project and to educate community members
likely to be impacted by the Glendale North OU project.
In general, the purpose of EPA's community relations program
for the San Fernando Valley project is to inform community members
and other interested parties about the Federal process for
addressing contamination at hazardous waste sites, as well as to
encourage two way communication between the concerned public and
EPA and/or other local agencies.
From March 1987 through December 1991, EPA and LADWP attended
quarterly meetings of the Community Work Group (CWG) to discuss
technical issues and management strategies involving the San
Fernando Valley Superfund project including the interim groundwater
cleanup for the Glendale area. The CWG consisted of interested San
Fernando Valley community residents, elected officials, agency
representatives, and environmental and business leaders. The CWG
provided input to EPA on the various components of the Superfund
project, including the interim groundwater cleanup of the Glendale
area.
The community relations plan for the San Fernando Valley
Superfund sites was most recently updated and issued in April 1990.
The plan will be revised again in 1993 to address community
relations during the remedial design phase of the Glendale North OU
interim action and other changes in the community relations
program.
5.0 SCOPE AND ROLE OF THE OPERABLE UNIT
The interim remedial action for the Glendale North OU
represents a discrete element in the overall long-term remediation
of groundwater in the eastern portion of the San Fernando Valley.
While the final overall plan for the remediation of the San
Fernando Valley Sites has not yet been determined, the objectives
of the Glendale North OU are:
o To inhibit vertical and horizontal migration of
groundwater contamination in the North Plume of the
Glendale Study Area
o To begin to remove contaminant mass from the upper zone
of the aquifer in the North Plume of the Glendale Study
Area.
10
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EPA does not expect these objectives to be inconsistent with,
nor preclude, any final action for San Fernando Valley Areas 1, 2,
3, and 4.
The Glendale North OU interim remedy is intended to address
the immediate and significant groundwater contamination problem in
and beyond a portion of San Fernando Valley Area 2 (also known as
the Crystal Springs NPL site) and includes a large section of the
City of Glendale. A more complete investigation of the overall
groundwater problem in the San Fernando Valley is being conducted
through the basinwide remedial investigation and feasibility study
process.
The basinwide groundwater RI Report for the San Fernando
Valley Study Area was completed in December 1992. Groundwater
. wells installed by EPA as part of the basinwide RI are routinely
sampled to continue to monitor the nature and extent of the
groundwater contamination in the San Fernando Valley.
EPA is currently using the results of the remedial
investigation in basinwide feasibility studies to address VOC
contamination in both the groundwater and vadose zone of the
eastern portion of the San Fernando Valley.
As part of the basinwide groundwater FS, EPA is revising and
recalibrating the basinwide groundwater flow model to incorporate
the most recent data. The updated version of the model will be
complete in early 1993. EPA will then review and evaluate various
groundwater remediation options for the basin including: regional
pump and treat, well-head treatment, use of innovative technologies
and no-action alternatives.
During 1993, EPA will also initiate work on a vadose zone FS
to examine ways to protect the groundwater from contaminants that
could reach the groundwater in the future. This FS will review and
evaluate options for cleanup of VOC contamination in the vadose
zone of the San Fernando Valley.
EPA will continue to gather and analyze information important
to the project. EPA has been working with the San Fernando Valley
water purveyors and the Upper Los Angeles River Area (ULARA)
Watermaster to summarize past and future groundwater management in
the San Fernando Valley, including an overall water balance for the
San Fernando Valley. EPA's interim actions to remove contaminants
and inhibit migration from the most contaminated areas in North
Hollywood, Burbank, Glendale North, Glendale South and Pollock OUs
will also provide information useful for the basinwide FS.
6.0 SUMMARY OF GLENDALE NORTH OU SITE CHARACTERISTICS
Results of LADWP's groundwater monitoring programs conducted
from 1981 through 1987 revealed that TCE and PCE had contaminated
11
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approximately 50 percent of the water supply wells in the eastern
portion""" of the San Fernando Valley groundwater basin at
concentrations exceeding State and Federal drinking water
standards.
The results of recent (1989-1992) EPA sampling of groundwater
monitoring wells installed by EPA throughout the San Fernando
Valley indicate that TCE and PCE continue to be the principal con-
taminants of concern. TCE and PCE are industrial solvents commonly
used in the metal degreasing and dry-cleaning industries. Both are
known animal carcinogens and probable human carcinogens. The
Federal MCL for both TCE and PCE is 5 ug/1 (ppb). The State MCLs
for TCE and PCE are also 5 ug/1 (ppb).
There are ten EPA monitoring wells located in the north plume
portion of the Glendale Study Area. In these ten wells, nine VOCs
have been detected above Federal and/or State MCLs: benzene;
carbon tetrachloride; 1,1-dichloroethane (1,1-DCA); 1,2-DCA; 1,1-
dichloroethene (1,1-DCE); total 1,2-DCE; 1,1,2,2-tetrachloroethane;
PCE; and TCE (See Tables 6-1 and 6-2). As reported in the RI
Report for the Glendale Study Area, TCE was detected in eight of
ten EPA monitoring wells in the north plume at a maximum
concentration of 12,000 ppb. PCE was detected in seven of the ten
wells at a maximum of 120 ppb. Groundwater samples from wells
installed at industry facilities in the Glendale north plume
portion of the Glendale Study Area, near potential sources of
contamination, have shown concentrations greater than 30,000 ppb
for TCE and greater than 500 ppb for PCE (See Figures 6-1 and 6-2).
Nitrate has been detected consistently at levels in excess of
the MCL in the groundwater of the Glendale Study Area. The highest
level detected in groundwater from a shallow monitoring well in the
Glendale Study Area is 16 mg/1 as nitrogen (See Figure 6-3). The
Federal MCL is 10 mg/1 for nitrate as nitrogen. The nitrate
contamination is likely the result of past agricultural practices
and/or septic systems in the San Fernando Valley. Nitrate is not
a CERCLA hazardous substance. However, the interim OU remedies in
the San Fernando Valley involve the distribution of treated water
to public water supply systems and therefore, EPA has been
compelled to address the nitrate contamination in developing
remedial alternatives.
Some metals have been detected at levels above the Federal
and/or State MCLs in groundwater monitoring wells located in the
Glendale Study Area. These metals include: arsenic, cadmium,
chromium, lead and mercury. MCL exceedances occurred in early
(1989) sampling rounds when field filtering of samples was not
performed. Subsequent sampling and current sampling protocol
require field filtering. As a result, only chromium and mercury
have been found to exceed their MCLs since the initial sampling and
only in a small number of wells. An analysis of these data to
examine the likelihood that the metals are waterborne contaminants
12
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TABLE 6-1
MAXIMUM VALUES OF VOLATILE AND SEMIVOLATILE ORGANIC COMPOUNDS DETECTED IN
GROUNDWATER FROM THE CRYSTAL SPRINGS CLUSTER WELLS
WITHIN THE NORTH PLUME OU
Constituent
Volatile Organics (/ig/l)
Acetone
Benzene
2-Butanone (MEK)
Carbon Tetrachloride
Chlorofonn
1 , 1 -Dichloroethane
1 ,2-Dichloroethane
1 , 1 -Dichloroethene
1 ,2-Dichloroethene (total)
Ethylbenzene
Methylene Chloride
1 , 1 ,2,2-Tetrachloroethane
TetrachJoroethene (PCE)
Toluene
1,1,1 -Trichloroethane (TCA)
Trichloroethene (TCE)
Xylene (total)
Semivolatile Organics (j»g/l)
Bis(2-ethylhexyl)phthalate
Di-n-octylphthalate
MCL'
(Mg/0
c
1.0
»-»c
0.5
100"
5.0
0.5
6.0
6.0r
680
-..*
1.0
5.0
1,000
200
5.0
1,750
4
_^_e
Shallow Cluster
Number of
Maximum Wells With
Concentration Detects
(Mg/l) out of 9
6'
0.8
22
42
23
39
2
100
17
ND
0.5"
8.0
120
0.4"
26
3,100
ND
ND
ND
4
1
1
4
4
3
1
3
3
0
2
2
8
1
3
9
0
_.
Wells"
Number of
Wells Which
Exceed MCL
0
4
0
2
1
2
1
0
0
2
6
0
0
8
0
...
t
Maximum
Concentration
(Mg/D
22
ND
ND
1.0
2.0
ND
ND
ND
ND
0.2
5.0*
2.0
130
3"
ND
220
1
140
11'
Lower Cluster
i
Wells"
Number of
Wells With Number of
Detects Wells Which
out of 12 Exceed MCL
5
0
...
2
1
0
0
0
...
1
7
1
9
3
0
8
2
1
1
...
0
...
2
0
0
0
0
...
0
0
1
6
0
0
6
0
...
Note: Samples collected May 1990 and October 1990
ND = Not Detected
' Promulgated federal or state MCL, whichever is more stringent.
b Shallow cluster wells include CS-COl-105, CS-CO2-62, CS-CO2-180, CS-CO3-100, CS-VPB-04, CS-VPB-05, CS-VPB-06, CS-CO5-160 and CS-C06-I85.
Lower cluster wells include all remaining cluster wells.
' No state or federal MCL promulgated. ,, ,
' MCLisforthesumoftrihalomethanes. Source: Remedial Investigation for the
' Detected in laboratory blanks; may be considered a lab contaminant. Glendale Study Area (January 1992)
' For sum of cis- and trans-isomers, use the MCL for cis-; this isomer is more prevalent and its MCL is lower.
-------
TABLE 6-2
MAXIMUM VALUES OF VOLATILE AND SEMIVOLATILE ORGANIC COMPOUNDS DETECTED IN
GROUNDWATER FROM THE CRYSTAL SPRINGS VERTICAL PROFILE BORINGS
WITHIN THE NORTH PLUME OU
Initial Sampling - September 1989b
Resampling - September 1990''
Maximum
MCL* Concentration
Constituent G»g") ' G«g/0
Number of
VPBs With
Detects
out of 10
Number of
VPBs which are
at or Exceed
MCL
Maximum
Concentration
G'g/0
Number of
VPBs With
Detects
out of 1 1
Number of
VPBs Which
are at or Exceed
MCL
Volatile Organics 0 Not Detected
Promulgated federal or state MCL, whichever is more stringent.
k Initially sampled wells include CS-VPB-01, CS-VPB-02, and CS-VPB-04 through CS-VPB-11; Rcsampled wells include CS-VPB-01 through CS-VPB-11.
No state or federal MCL promulgated.
' MCL is for the sum of trihalomethanes.
Delected in laboratory blanks; considered a lab contaminant.
' For sum of cis- and trans-isomers, use the MCL for cis-; this isomer is more prevalent and its MCL is lower.
Source: Remedial Investigation for the Glendale Study Area (January 1992)
-------
.V' » .'V
x . sS Vy
V" < .' j-
* s ^ *
NORTH PLUME OU
MONITORING WELL
CLUSTER WELL
VPB WELL
PHILIPS
COMPONENTS
SITE
TCE CONCENTRATION IN GROUNDWATER POTENTIALLY-0
EXCEEDING 5000 ug/l
TCC CONCENTRATION IN GROUNDWATER POTENTIALLY
RANGING FROM 500 ug/l TO 5000 ug/l
TCE CONCENTRATION IN GROUNOWATER POTENTIALLY
RANGING FROM 100 ug/l TO 500 ug/l
TCE CONCENTRATION IN GROUNDWATER POTENTIALLY
RANGING FROM 50 ug/l TO 100 ug/l
TCE CONCENTRATION IN GROUNDWATCR POTENTIALLY
RANGING FROM 5 ug/l (MCL) TO 50 n»|/l
FIGURE 6-1
ESTIMATED EXTENT OF TCE CONTAMINATION
IN THE UPPER ZONE AT THE WATER TABLE
SEPT.-OCT. 1990
NORTH PLUME OPERABLE UNIT
FEASIBILITY STUDY
-------
NORTH PLUME OU
V/V/
A.C. LAYNE SITE
PMC-MW-04
COLORADO BLVD
-VPB-02
PHILIPS
COMPONENTS
SITE
CLUSTER WELL
VPB WELl
PCE CONCENTRATION IN GROUNDWATER POTENTIALLY
RANGING FROM 100 ug/l TO 500 ug/l
PCE CONCENTRATION IN GROUNDWATER POTENTIALLY
RANGING FROM SO ug/l TO 100 ug/l
PCE CONCENTRATION IN GROUNDWATER POTENTIALLY
RANGING FROM 5 ug/l (MCL) TO 50 ug/l
FIGURE 6-2
ESTIMATED EXTENT OF PCE CONTAMINATION
IN THE UPPER ZONE AT THE WATER TABLE
SEPT.-OCT. 1990
PO-VPB-OI
A
NORTH PLUME OPERABLE UNIT
FEASIBILITY STUDY
-------
NORTH PLUME OU
CLENOAKS BLVO
A
-VPB-tl
PHILIPS
COMPONENTS
NITRATE CONCENTRATIONS
GREATER THAN 10 mg/l-N
tono o 1000 2000
rtti
FIGURE 6-3 £
ESTIMATED EXTENT OF NITRATE CONTAMINATION <
IN UPPER ZONE \
SEPT.-OCT. 1990
NORW PLUME OPERABLE UNIT
FEASIBILITY STUDY
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rather than sampling artifacts (i.e., residual particulates from
well construction and development) was conducted by EPA's
contractor and presented in a technical memorandum entitled:
Review of Metals Data from Monitoring Wells located in the Glendale
Study Area. North Operable Unit (June 16, 1992) . This memorandum,
available for review in the Administrative Record for the Glendale
North OU, concluded that the metals exceedances were most likely
the result of sampling artifacts. EPA continues to analyze
groundwater samples collected under the quarterly monitoring
program for priority pollutant metals.
Thirty-one wells in the Glendale Study Area were sampled for
naturally-occurring radionuclides as part of EPA's quarterly
monitoring program. The samples were taken during the period of
July 31 to August 7, 1992. The results of this third quarter 1992
groundwater sampling for radionuclides. indicate that all EPA
groundwater monitoring wells in the Glendale Study Area are in
compliance with current MCLs for radionuclides (gross alpha, gross
beta, gross radium, radium-226, strontium-89, strontium-90, gross
uranium, tritium, and radon). In addition, the samples were also
in compliance with all proposed radionuclide MCLs, except radon.
The proposed MCL for Radon is 300 pCi/1. Most of the groundwater
samples from the 31 monitoring wells exceeded the proposed MCL for
radon. If necessary, this factor will be taken into account for
remedial design. Radionuclides in the groundwater of the Glendale
Study Area and their potential impacts on the design of the
Glendale North OU are discussed in greater detail in: Technical
Memorandum San Fernando Valley Superfund Site, Radionuclides in the
Glendale Study Area, dated March 2, 1993. This memorandum is
available for review in EPA's Administrative Record Supplement 1
for the Glendale North OU.
In addition, during the RI for the Glendale Study Area, EPA
confirmed through modeling that the groundwater in the area is a
source of recharge for the Los Angeles River.
7.0 SUMMARY OF SITE RISKS
Data regarding contaminants in the north plume of groundwater
contamination in the Glendale Study Area obtained by EPA during the
remedial investigation was used to estimate the health risks
associated with exposure to the groundwater. This estimate, called
a risk assessment, was then used to identify which contaminants
pose risks to human health. The data used for the Glendale North
OU risk assessment is presented in the Remedial Investigation
Report for the Glendale Study Area (January 1992) and in other
documents include in the Glendale North OU Administrative Record
file.
Baseline risk assessments are conducted at Superfund sites to
fulfill one of the requirements of the National Oil and Hazardous
Substances Pollution Contingency Plan (NCP). The NCP (40 CFR Part
13
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300) requires development of a baseline risk assessment at sites
listed on the National Priorities List (NPL) under CERCLA. The
CERCLA process for baseline risk assessments is intended to address
both human health and the environment. However, due to the highly
urbanized setting of the Glendale Study Area, the focus of the
baseline risk assessment for the Glendale North OU was focused on
human health issues, rather than environmental issues.
The objective of the baseline risk assessment for the Glendale
North OU was to evaluate the human health and environmental risks
posed by the contaminated groundwater beneath the north plume
portion of the Glendale Study Area if it were to be used as a
source of drinking water without treatment. The baseline risk
assessment incorporated the water quality information generated
during the basinwide groundwater RI field investigation and
sampling program to estimate current and future human health and
environmental risks. The groundwater data used for the Glendale
North OU risk assessment included sampling results from the 1990
Crystal Springs initial cluster well sampling, and the 1991
resampling of the Crystal Springs Vertical Profile Borings/shallow
monitoring wells (VPBs). In cases where more than one sample event
was recorded for a single well, the most recent data were used. If
a compound was not detected in a particular well, half the value of
the lowest detection limit was used from the most recent sampling
event. The current public health risk calculations were based on
estimates of concentrations at points of exposure from these
sampling efforts.
The risk assessment for the Glendale North OU was conducted in
accordance with EPA guidance including: Guidance for Conducting
Remedial Investigation and Feasibility Studies under CERCLA (USEPA,
1988), Risk Assessment Guidance for Superfund. Vol. I Health
Evaluation Manual (Part A) and Vol. 2JEcological Assessment (USEPA,
1989), The Exposure Factors Handbook (USEPA, 1989), and Risk
Assessment Guidance for Superfund Human Health Risk Assessment.
USEPA Region IX Recommendations (USEPA, 1989).
A risk assessment involves the qualitative or quantitative
characterization of potential health effects of specific chemicals
on individuals or populations. The risk assessment process
comprises four basic steps: 1) hazard identification, 2) dose-
response assessment, 3) exposure assessment, and 4) risk
characterization. The purpose of each element is as follows:
Hazard identification characterizes the potential threat
to human health and the environment posed by the detected
constituents.
Dose response assessment critically examines the
toxicological data used to determine the relationship
between the experimentally administered animal dose and
14
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the predicted response (e.g., cancer incidence) in a
receptor.
Exposure assessment estimates the magnitude, frequency,
and duration of human exposures to chemicals.
Risk characterization estimates the incidence of or
potential for an adverse health or environmental effect
under the conditions of exposure defined in the exposure
assessment.
Human Health Risk Assessment
Risk assessments estimate the possibility that one additional
occurrence of cancer will result from exposure to contamination.
A risk of 1 in 1,000,000 (one million) means that one person in one
million exposed could develop cancer as a result of the exposure.
EPA considers risks greater than one in ten thousand (10~4)
"unacceptable."
In preparing risk assessments, EPA uses very conservative
assumptions that weigh in favor of protecting public health. For
example, EPA may assume that individuals consume two liters of
drinking water per day from wells situated within a contaminant
plume, over a 70-year lifetime or that a person is exposed to a
chemical, 24 hours a day, 365 days a year, for a 30-year period,
even though typical exposure to the chemical would be far less.
The baseline risk assessment for the Glendale North OU is
presented in Section 7.0 of the Remedial Investigation Report for
the Glendale Study Area (January 1992)i The risk assessment
estimated the potential risks to public health under current
situations and potential future situations. The risk assessment
examined the potential health effects if individuals were exposed
to contaminated groundwater from the upper and lower zones of the
aquifer for the Glendale north plume groundwater contamination in
the Glendale Study Area.
Chemicals of potential concern for the Glendale North OU used
in the risk assessment calculations included: TCE; PCE; carbon
tetrachloride; 1,1-DCA; 1,2-DCA; total 1,1-DCE; 1,2-DCE; nitrate
and others including some metals. A list of all potential
compounds of concern for both the upper and lower aquifer zones
included in the quantitative risk assessment for the Glendale North
OU are presented in Table 7-1. Due to the potential for adverse
health effects to infants from consumption of water with high
nitrate levels, a quantitative evaluation of this compound for
chronic non-carcinogenic risks was calculated. The maximum value
and an average value were used for exposure point concentrations in
the calculations.
15
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TABLE 7-1
COMPOUNDS OF POTENTIAL CONCERN INCLUDED IN THE QUANTITATIVE
RISK ASSESSMENT FOR THE GLENDALE NORTH PLUME OU
Constituent
Upper
Zone
(Yes/No)
Lower
Zone
(Yes/No)
VOCS
Benzene
Carbon Tetrachloride
1,l-Dichloroethane
1,2-Dichloroethane
Tetrachloroethene
Trichloroethene
1,1-Dichloroethene
1,1,2,2-Tetrachloroethene
2-Butanone (MEK)
1,2-Dichloroethene (total)
BNAs
Bis(2-ethylhexyl)phthalate
Inorganics
Arsenic
Nickel
Lead
Mercury
Zinc
Nitrate
y
Y
Y
Y
Y
Y
Y
Y
Y
Y
N
Y
Y
N
Y
Y
Y
N
Y
N
N
Y
Y
N
Y
N
N
N
N
Y
Y
Y
Y
-------
As indicated by the table, fewer compounds of potential
concern were identified in samples from wells installed in the deep
aquifer. Therefore, a separate characterization of risk was
performed for the upper and lower groundwater zones.
An exposure assessment was conducted to identify potential
transport pathways (e.g., groundwater, surface water, air); routes
of exposures (e.g., ingestion, inhalation, dermal contact); and
potential on-site and off-site receptor populations. Exposure
assessment involves the consideration of particular transport
pathways and routes of exposure to potential receptors which may
include current users of the site as well as adjacent populations
that may be exposed to chemicals that have been transported off
site. Receptors may also include aquatic and terrestrial biota.
A critical step in assessing the potential risk to public
health is to identify the pathways through which exposure could
occur. The major transport pathway considered in the Glendale
North OU baseline risk assessment was the use of contaminated
groundwater. The point of potential contact with the contaminated
groundwater is through water use from the upper or lower zone.
EPA evaluated four potential methods of exposure to water from
the upper and lower zones of the aquifer: (1) exposure during
residential use, (2) worker exposure during operations at the
Glendale Grayson Steam Plant (3) exposure from discharge into the
Los Angeles River, or (4) exposure in various other commercial
uses. Other commercial users of groundwater in the Glendale Study
Area include Walt Disney; Sears, Roebuck & Co.; and the Los Angeles
City Zoo. The residential use of the contaminated groundwater as
well as exposure from Glendale Grayson Steam Plant operations were
carried into the quantitative risk assessment.
EPA included three potential exposure routes in the Glendale
North OU risk assessment: (1) drinking the groundwater during
residential use, (2) inhaling the chemicals in groundwater vapors
during showering, and (3) inhaling groundwater vapors during steam
plant operations. Dermal contact was also considered but was found
by EPA not to pose a significant risk.
In accordance with current scientific opinion concerning
carcinogens, it is assumed that any dose, no matter how small, has
some associated response. This is called a nonthreshold effect.
In the risk assessment for the Glendale North OU, the non-threshold
effect was applied to all probable carcinogens. EPA has classified
carcinogens with regard to the epidemiologic and toxicologic data
available. The assessment of noncarcinogenic effects is complex.
There is a broad interaction of time scales (acute, subchronic, and
chronic) with varying kinds of effects. In addition, there are
various levels of "severity" of effect. The Hazard Index is used
to determine the potential for adverse health effects resulting
from exposure to non-carcinogenic chemicals.
16
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The Hazard Quotient is defined as the ratio of a single
exposure level over a specified time period to a reference dose for
that substance derived from a similar exposure period. A reference
dose (RfD) is EPA's preferred toxicity value for evaluating non-
carcinogenic effects resulting from exposures at Superfund sites.
The Hazard Index is the sum of more than one Hazard Quotient for
multiple substances or multiple pathways. The Hazard Index is
calculated separately for chronic, sub-chronic and shorter-duration
exposures. A Hazard Index greater than 1.0 indicates the potential
for adverse health effects. However, it should be noted that a
Hazard Index value of 1.0 or greater does not mean that an adverse
health effect is certain. It is a benchmark value indicating a
greater probability for a possible adverse effect.
The results of the baseline risk characterization for the
upper and lower zones of the aquifer are summarized in Tables 7-2
and 7-3. A detailed discussion of the data presented in these
tables is included in Section 7.0 of the Remedial Investigation
Report for the Glendale Study Area (January 1992).
The risk associated with ingestion of groundwater from the
upper zone found that TCE, l,l-DCE and arsenic were the primary
contributors to the carcinogenic risk in the ingestion scenario.
PCE and carbon tetrachloride were secondary contributors.
Concentration levels of TCE and Ijl-DCE were several orders of
magnitude above their respective MCLs, but concentrations of
arsenic were detected below its MCL. For shower inhalation risks,
TCE and l,i-DCE were major contributors to risk for groundwater in
the upper and lower zones.
The uncertainties associated with the Glendale North OU risk
assessment are discussed in detail in Section 7.6 (page 7-24) of
the Remedial Investigation Report for the Glendale Study Area
(January 1992).
In summary, the results of the human health portion of the
Glendale North OU risk assessment indicated that contaminant levels
in the upper zone of the aquifer of the Glendale Study Area would
pose an unacceptable (2 x 10"3) risk to human health if this water
were to be delivered directly to local residents, without being
treated. This means that an estimated 1 in 500 persons would be
more likely to develop cancer during their lifetimes.
Environmental Risk Assessment
An ecological risk assessment was also performed for the
Glendale North OU to address the potential ecological risks to
flora and fauna in the area. This assessment provided a
qualitative evaluation of potential current and future risks
represented by the present site conditions, assuming no remedial
action is taken in the Glendale Study Area.
17
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TABLE 7-3
SUMMARY OF RISK CHARACTERIZATION FOR THE
LOWER ZONE AQUIFER
FOR THE GLEMDALE NORTH FLUKE OU
Exposure
Scenario
Adult
Ingestion
Shower -
Inhalation
Steam Plant
Inhalation
Arithmetic
Mean1
2E-05
3E-01
IE-OS
2E-01
RKE2 Maximum3
5E-05 1E-04
7E-01 2E+00
2E-05 6E-^05
4E-01 1E+00
1E-07
2E-03
Type of
Risk
Cancer Risk
Hazard Index
Cancer Risk
Hazard Index
Cancer Risk
Hazard Index
1 Average Value
2 Reasonable Maximum Exposure. The highest exposure that
is reasonably expected to occur at a site (95% upper confidence
limit of observed concentrations).
3 The exposure scenario using the highest observed
concentration in any monitoring well in the north plume of
groundwater contamination of the Glendale Study Area.
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TABLE 7-2
SUMMARY OF RISK CHARACTERIZATION FOR THE
UPPER ZONE AQUIFER
FOR THE GLENDALE NORTH PLUME OU
Exposure
Scenario
Arithmetic
Mean1
RMEa
Maximum3
Type of
Risk
Adult
Ingestion
8E-04
4E+00
2E-03
8E+00
5E-03
2E+01
Cancer Risk
Hazard Index
Shower
Inhalation
1E-03
4E+00
2E-03
8E+00
8E-03
2E+01
Cancer Risk
Hazard Index
Steam Plant
Inhalation
2E-05
4E-02
5E-05
7E-02
Cancer Risk
Hazard Index
1 Average Value
2 Reasonable Maximum Exposure. The highest exposure that is
reasonably expected to occur at a site (95% upper confidence
limit of observed concentrations).
3 The exposure scenario using the highest observed
concentration in any monitoring well in the north plume of
groundwater contamination in the Glendale Study Area. EPA
considers this scenario to be unreasonably high.
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The Glendale Study Area is-zoned for commercial and industrial
establishments. The surrounding area is a mixture of residential
and commercial zoning. Although an extensive ecological survey was
not performed for the area, the presence of a significant wildlife
population was not indicated. In addition, the developed condition
of the site excludes the potential for significant natural
vegetative cover.
The release pathway of primary concern at this site is
contaminated groundwater. There is no information, at present, to
indicate that this groundwater reaches the surface or that
significant concentrations are discharged to a surface water source
(i.e., canal, river, etc.). Discharges to the Los Angeles River
are likely to occur but are not expected to be significant enough,
in volume or frequency, to impact aquatic biota.
Given the present developed condition of the site and the
major exposure pathway consideration of contaminated groundwater,
there was no expectation for significant impact to potential
environmental receptors. Urbanization has already replaced habitat
potential; therefore, no significant number of receptors appeared
to be present. There appeared to be no apparent mechanism for
exposure to environmental receptors from contaminated groundwater.
Also, there was no indication that future site plans would
reinstate habitat and thereby recreate a potential for
environmental receptors in the future.
8.0 DESCRIPTION OF ALTERNATIVES
Based on the results of the RI, EPA identified several cleanup
alternatives for addressing groundwater contamination in the
Glendale North Plume. The alternatives were developed to meet the
following specific cleanup objectives for the Glendale North OU:
o To inhibit vertical and horizontal migration of
groundwater contamination in the North Plume of the
Glendale Study Area; and
o to begin to remove contaminant mass from the upper zone
of the aquifer in the North Plume of the Glendale Study
Area.
All of the alternatives, with the exception of the "no action"
alternative (Alternative l), involve groundwater extraction and
treatment for the shallow aquifer system in the Glendale area of
the San Fernando Valley. The upper zone or shallow-most portion of
the aquifer is where the majority of the VOC contamination has been
identified. Detailed descriptions of the various alternatives are
presented in the Feasibility Study for the Glendale Study Area
North Plume Operable Unit (April 1992).
18
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Initially, all of the alternatives were screened for: 1)
effectiveness at protecting public health and the environment, 2)
technical feasibility (implementability), and 3) cost. As a result
of this initial screening, seven alternatives were evaluated using
nine specific criteria: l) Overall Protection of Human Health and
the Environment, 2) Compliance with Applicable or Relevant and
Appropriate Requirements (ARARs), 3) Long-term Effectiveness and
Permanence, 4) Reduction of Toxicity, Mobility or Volume through
Treatment, 5) Short-term Effectiveness, 6) Impleroentability, 7)
Cost, 8) State Acceptance, and 9) Community Acceptance. Each of
EPA's nine evaluation criteria is summarized below.
Overall Protection of Human Health and the Environment; This
criterion assesses whether each alternative provides for both short
term and long term overall protection of human health and the
environment from unacceptable risks posed by the hazardous
substances, pollutants, or contaminants present in the North Plume.
The assessment draws upon the evaluation of short-term
effectiveness, long-term effectiveness, implementability, reduction
of toxicity, mobility and/or volume through treatment, and
compliance with ARARs.
Compliance with ARARs; This criterion is used to determine whether
the alternative meets all of the chemical-, action- and
location-specific ARARs identified in Section 10 of this ROD.
Since the remedial action established by the Glendale North OU ROD
is an interim action, chemical-specific requirements to be attained
in the aquifer at the end of the final remedy are not ARARs for
this action. Action-specific ARARs address the groundwater
response actions that may be taken as part of this interim action
for the Glendale North OU. All of the alternatives, except no
action, include groundwater extraction followed by treatment and
disposal or use as potable supply. Therefore, specific levels for
treatment of the contaminated water prior to disposal or to
delivery to the drinking water purveyor are chemical-specific and
action-specific ARARs for the Glendale North OU.
Long-Term Effectiveness and Permanence; Long-term effectiveness
refers to the period after the remedial action is complete. Each
alternative is assessed for its long-term effectiveness and
permanence in reducing the risk to human health and the environment
at the end of the 12-year period. The long-term effectiveness
evaluation focuses on how much total contaminant mass has been
removed and contaminant concentrations remaining in the aquifer at
the end of the 12-year period.
Reduction of Toxicitv. Mobility, and/or Volume through Treatment;
This criterion addresses how well the remediation technologies
permanently and significantly reduce the toxicity, mobility and/or
volume of the hazardous substances. The evaluation based on this
criterion focuses on the quantity of hazardous materials destroyed
or treated, the degree to which the remedial action is
19
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irreversible, the type and quantity of residuals that are remaining
after the remedial action is complete, and whether the alternative
satisfies the statutory preference for treatment as a principal
element of the remedy.
Short-Term Effectiveness; Each alternative is evaluated based on
its effectiveness in protecting human health and the environment
during the construction and implementation period. The short-term
effectiveness evaluation for each alternative focuses on how well
the alternative removes contaminant mass, inhibits the movement of
the contaminant plume, and how well the treatment system meets the
cleanup levels in the extracted and treated groundwater during the
12-year period. Short-term effectiveness also addresses the
effectiveness of the alternative in reducing potential risks to
people living in the vicinity of the Glendale North Plume and to
workers' health and safety during construction of the proposed
facilities and implementation of the interim remedy.
Implement ability; The implementability criterion includes both the
technical and administrative feasibility of implementing an
alternative. The technical feasibility refers to the ability to
construct, reliably operate and maintain, and meet cleanup levels
for process options. Administrative feasibility refers to the
ability to obtain approvals from other offices and agencies, the
availability and capacity of treatment, storage, and disposal
services, and the availability of specific equipment and technical
specialists.
Cost; The NCP requires that the following types of costs be
evaluated: 1) Capital costs, including both direct and indirect
costs, 2) Annual operation and maintenance costs and 3) Net present
value of capital and operations and maintenance (O&M) costs.
Capital and O&M costs presented in the Glendale North OU FS report
have an accuracy of +50 percent to -30 percent, as specified by the
Guidance for Conducting Remedial Investigations and Feasibility
Studies Under CERCLA (USEPA, 1988). Capital costs include a
contingency of 20 percent of total field cost (TFC) and a
contractor's overhead and profit (OH&P) at 30 percent of the sum of
TFC and contingency. Evaluating present worth costs assumes an
interest rate of 10 percent and operating period of 12 years. The
O&M cost evaluation assumes an operating load factor of 90 percent.
State Acceptance; This criterion considers the concerns of the
State (technical and administrative) regarding the alternatives.
Public Acceptance; This criterion assesses the components of
alternatives that interested persons in the community support, have
reservations about or oppose.
EPA's preferred alternative, as well as the other six
alternatives were described in EPA's Proposed Plan for the Glendale
North OU (July 1992).
20
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ffie Glendale North OU is an interim action and is not the
final remedy for cleanup of contaminated groundwater in the
Glendale area. With the exception of the no action alternative,
all of the alternatives involve the extraction of 3,000 gpm of
groundwater for a period of 12 years. The total duration of the
remedy is 15 years, but during the first three years the remedy
will be in the remedial design and construction phases and no
extraction or treatment of groundwater will be taking place. A
computer model called a solute transport model was developed and
used to determine that the extraction rate of 3,000 gpm over a 12
year period would result in the most effective inhibition of plume
migration and effective contamination removal for this interim
action. With the exception of Alternative 1 - No Action, all of
the alternatives would involve the construction and operation of a
VOC treatment system.
With the exception of Alternative l - No Action, the seven
alternatives analyzed and compared during the FS and presented in
the Glendale North OU FS report include three major elements: 1)
extraction of contaminated groundwater at the rate of 3000 gpm, 2)
treatment of the VOCs, and 3) one of four options for final use -
distribution to a public water supply system, reinjection into the
aquifer, spreading at an existing spreading grounds, or discharge
to the Los Angeles River (See Table 8-1). The major elements of
each of seven alternatives are listed below.
Alternative l NO Action
Alternatives 2 Extract/Treat VOCs(air stripping or
liquid phase GAC)/Public Water
Supply
Alternative 3 Extract/Treat VOCs(perozone)/Public
Water Supply and/or Reinject
Alternative 4 Extract/Treat VOCs/River
Alternative 5 Extract/Treat VOCs plus ion exchange
for nitrate/Reinject
Alternative 6 Extract/Treat VOCs/Spreading Grounds
Alternative 7 Extract/Treat VOCs/Reinject
The highlights of the seven alternatives are summarized
briefly below. More detailed descriptions of the alternatives are
presented in the Feasibility Study for the Glendale Study Area
North Plume Operable Unit (April 1992).
21
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Table 8-1: Summary of AlternativesGlendale North OU
Components
Groundwater Extraction
Treatment
Final Use
CRITERIA
Effectiveness and
Permanence
HeajKon ol Toxsiy. MoSnty.
Volume, ana Treatment
Compliance »:-. ARARs
Overall Protection of human
Heaitn ar.d Environment
(Human Hea'th)
[Environment)
ImplementaDility
(Tecnncal)
ESTIMATED COSTS
Total Capital Cost
Annual O&M
Total Present Wonh
Alternative 1
None
None
Monitor groundwater quality
Not effective in the short or long-term
No reduction of toxicity, mobility, or
volume
Will not meet ARARs
Assuming no institutional controls,
increased lifetime cancer risk of
ingesting contaminated groundwater
is estimated to be 1 in 500
Not protective of environment
Monitoring wells easy to construct
Spread of groundwater plume could
make future remediation difficult
$230.000
$110,000
$791,000
Alternative 2
Extract 3000 gpm groundwater feom
12 wells
Treat VOCs with dual-stag* air
tripping and vapor-phase GAC
Meet nitrate MCL toy blending
Convey treated, blended water to "i:----
. City of Glendale'* PublteDiBtraxrton;
: System : -*;-" - ,'.'
EVALUATION
Inhfeit vertical and lateral migration;
of contaminant plume , ;
No contaminated groundwater
discharged to Los Angeles River
Remove contaminant maas from
aquifer . :
Treated groundwater would meet
drinking water standards
Estimated to reduce TCE concentra-
tions in the aquifer from 600 ppbto
less than 100 ppb attar 12 years
Removes 82% o( the rnfttial mass of
TCE in the aquifer
Wit meet ARARs
Protective of human health
Environmental degradation will be
reduced because migration of .
groundwater contain^ TCE
concenbalions inhibftetf and TC£
masa removed
Can be implemented
V
~
si9.eoo.ooo
$3^40.000 >-,-,'
$36,400,000
Alternative 3
Same as Alternative 2
Treat VOCs with perozone oxidation,
airstripping, and vapor-phase GAC
Same as Alternative 2
Same as Alternative 2
Same as Alternative 2
Same as Alternative 2
Same as Alternative 2
Same as Alternative 2
Same as Alternative 2
* Same as Alternative 2
Same as Alternative 2
Same as Alternative 2
Same as Alternative 2
Same as Alternative 2, except
perozone oxidation treatment proven
at pilot scale only
S17.BOO.000
$2,610.000
S31.200.000
EPA's Preferred alternatives.
Alternative *S presented here in this Proposed Plan was formerly Alternative *8 in the Feasibility Study for the Glendale Sfjfly Area- North Plume
O;e-aB!e 'J-ii'. (Asr.; 199?'.
Aite;r.a;ive *7 p'esented here in this Proposed Plan was formerly Alternative *10 in the Feasibility Study for the Glendale Study Area: North Plume
Ose'aS'e LJ-X iAs'i! 1992).
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Table 8-1 (cont): Summary of AlternativesGlendale North OU
Alternative 4
Same as Alternative 2
Same as Alternative 2
Discharge treaiea water to Los
Angeles River
Alternative 5*
Same as Alternative 2
Same as Alternative 2. plus treat-
ment of nitrate with ion exchange
Inject 3,000 gpm treated water into
12 wells
Alternative 6
Sam» as Alternative 2
Sam* as Alternative 2
Discharge treated water to
Headworks Spreading Ground
EVALUATION
Same as Alternative 2
Same as Alternative 2
Same as Alternative 2
Treated g-ojicwate- wa-M meet
Brining wa:e- staissrss for VOCs
and $j<1ace waie- fl.scnarge
standards for nitrates
Sa me as Attema :we 2
Same as Alternative 2
Same as Auemat've 2
Same as Alternative 2
Same as Aternative 2
Same as Afle.-natwe 2
$17,700.000
S3.0SO.OOO
$33.300.000
Same as Alternative 2
Groundwater discharge to Los
Angeles River may be greater than
Alternative 2 (but TCE concentra-
tions lower)
Same as Alternative 2
Same as Alternative 2
Estimated to reduce TCE concentra-
tions from 600 ppb to less than 100
ppb after 12 years
Removes 69% of initial mass of TCE
in the plume
Same as Alternative 2
Same as Alternative 2
Same as Alternative 6, except
greater mass of TCE removed
Same as Alternative 2; issues
associated with waste brine disposal
(from ion exchange) and with
injection (e.g., potential for clogging)
will have to be addressed
S37.000.000
$4.760.000
$61.400,000
Same as Alternative 2
Same as Alternative 2
Sam* as Alternative 2
Treated groundwater would meet
drinking water standards for VOCs
and groundwater recharge standards
for nitrates
Sam* as Alternative 2
Removes 66% of the initial mass of
TCE in the plume
Sam* as Alternative 2
Same as Alternative 2
Same as Alternative 2, except
greater mass of TCE removed
Same as Alternative 2; on*
administrative issue may be the
availability of the Headworks
Spreading Grounds (or recharge
$19.600.000
S3.300.000
$36,500.000
Alternative?**
'> Same as Alternative 2
Seme as Alternator* 2
Same as Alternative 5
Sam*asAH*mattv*2 .
Same as Alternative 5
Same as Alternative 5
Same a* Alternative 5
Sam* as Alternative 5
Sam* a* Altemativ* 5
Sent* a* Alternative 2
Sam* «s Alternative 2
Same * Alternatives .. .
>
Same as Alternative 2, saeept issues
associated wRn Injection (e.g..
dogging), which win have to be pilot-
tested prior to fuB-*cale Implementa-
tion -,
S21.800.000
$3.300,000
$38.700.000
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Alternative 1; No Action
The No Action alternative serves as a "baseline" against which
other alternatives are compared. This alternative is evaluated to
determine the risks that would be posed to public health and the
environment if no action were taken to treat or contain the
contamination. The no action alternative would involve only
groundwater monitoring; no additional cleanup activities would be
conducted.
Alternative 2; EPA's Preferred Alternative
Extract/TreatrAir Stripping or Liquid Phase GAC1/Public Water
System
Alternative 2 involves the extraction of 3,000 gpm of
contaminated groundwater for 12 years. The extraction wells would
be located to inhibit most effectively the migration of the
contaminant plume. Various locations and scenarios for extraction
wells and rates of extraction are proposed in the feasibility study
report.for the Glendale North OU. However, all design decisions
for this interim remedy will be made during the remedial design
phase. At that time, one of the locations proposed for extraction
wells and scenarios for rates of extraction at individual wells may
be selected or new ones may be selected.
The extracted groundwater will be filtered to remove any
suspended solids, if necessary, and then treated for VOCs using
dual-stage or single-stage air stripping with vapor-phase GAC
adsorption for emissions control or liquid phase GAC. Whether air-
stripping (dual versus single) or liquid phase GAC will be used
'Will be determined during remedial design as will the exact
location for the treatment plant (note that four possible locations
were proposed in the Glendale North OU FS report). The treated
water will be blended with water which does not contain nitrate in
excess of the nitrate MCL to reduce nitrate levels to meet the
nitrate MCL. The treated water shall meet all ARARs identified in
Section 10 of this ROD and will be conveyed to the City of Glendale
and/or another San Fernando Valley water purveyor for blending and
distribution through the public supply system. The treated,
blended water will have to meet all applicable drinking water
requirements for drinking water in existence at the time that the
water is served prior to distribution through the public drinking
water supply system.
In response to comments by the City of Glendale on the
Glendale North and South OU Proposed Plans and in order to decrease
overall costs associated with the OUs, EPA has determined that the
treatment plants for the Glendale North and Glendale South OUs will
be combined and the total 5,000 gpm of treated water will be
conveyed to the City of Glendale for distribution to its public
water supply system. The exact location of the combined treatment
plant will be determined during the remedial design phase of the
22
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project. The Glendale South' OU Record of Decision will also
reflect this decision to combine the treatment plants.
However, if the City of Glendale does not agree to accept the
treated water from both OUs (possibly due to water supply needs) or
if EPA determines that combining the treatment plants will
significantly delay or hinder the implementation of the Glendale
North OU, the treatment plants will not be combined. Furthermore,
if the city of Glendale does not accept any or all of the treated
water, any remaining portion of water will be 1) offered to another
San Fernando Valley water purveyor or 2) reinjected into the
aquifer, per Alternative 7 (see description below).
Existing production wells that may provide pathways for
vertical migration of contamination will be abandoned or
.rehabilitated, if required. Final determinations regarding which
production wells will be abandoned and/tor rehabilitated will be
made during remedial design. Groundwater monitoring wells will be
installed to evaluate the effectiveness of the remedial action.
More specifically, groundwater monitoring shall be conducted no
less frequently than quarterly to: 1) evaluate influent and
effluent water quality, 2) determine and evaluate the capture zone
of the extraction wells, 3) evaluate the vertical and lateral
(including downgradient) migration of contaminants, 4) evaluate the
effectiveness of the reinjection well system, if necessary and 5)
monitor any other factors associated with the effectiveness of the
interim remedy determined to be necessary during remedial design.
Alternative 3; Extract/Treat(Perozone Oxidations/Public Water
System
Alternative 3 also requires the extraction of 3,000. gpm of
contaminated groundwater for 12 years, and the same final use of
the treated water and the same groundwater monitoring requirements
as Alternative 2. Alternative 3 only differs from Alternative 2 in
that the extracted groundwater would be treated for VOCs using
perozone oxidation, followed by air stripping with vapor-phase GAC
adsorption for emissions control. Air stripping would be required
to remove any carbon tetrachloride in the extracted groundwater
because the perozone oxidation process alone does not effectively
treat this VOC.
Alternative 4: Extract/Treat/River
Alternative 4 also involves the extraction of 3,000 gpm of
contaminated groundwater for 12 years, and the same treatment
methodology and the same groundwater monitoring requirements as
Alternative 2. However, rather than providing the treated water to
a public water purveyor, the treated water would be discharged to
the Los Angeles River.
23
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Alternative 51: Extract/Treat-plus Ion Exchange/Reinject
Alternative 5 also involves the extraction of 3,000 gpm of
contaminated groundwater for 12 years, and the same monitoring
requirements as Alternative 2. Alternative 5 differs from
Alternative 2 in that the extracted groundwater would be treated
for VOCs using dual-stage air stripping with vapory-phase GAC
adsorption for emissions control and then would be treated using
ion exchange to reduce the nitrate levels in the water to meet the
nitrate MCL. The treated water would then be reinjected.
Alternative 6: Extract/Treat/Spreading Grounds
Alternative 6 also involves the extraction of 3,000 gpro of
contaminated groundwater for 12 years, the same treatment approach
as described in Alternative 2 and the same ground water monitoring
requirements as Alternative 2. However, ..unlike Alternative 2, the
treated water would be recharged to the aquifer at the Headworks
Spreading Grounds.
Alternative 72; Extract/Treat/Reinject
Alternative 7 also involves the extraction of 3,000 gpm of
contaminated groundwater for 12 years, the same treatment system,
the same groundwater monitoring requirements and provides for
abandonment or rehabilitation of production wells as required for
Alternative 2. However, the treated water would be reinjected.
The reinjection shall occur where nitrate levels in the aquifer are
equal to or greater than the nitrate levels in the water to be
reinjected.
9.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
A comparative analysis of the alternatives against the nine
evaluation criteria is presented in this section.
No Action versus the Nine Criteria. Clearly, Alternative 1 would
not be effective in the short- and long-term in protecting human
health and the environment as it does not provide for removing any
contaminants from the upper zone of the aquifer, for inhibiting
further downgradient and vertical contaminant plume migration, or
for reducing the toxicity, mobility and volume of contaminants
through treatment. Implementing the no-action alternative would be
1 Note: Alternative #5 presented here in this ROD was
formerly Alternative #8 in the Feasibility Study for the Glendale
Study Area: North Plume Operable Unit (April 1992).
2 Note: Alternative #7 presented here in this ROD was
formerly Alternative #10 in the Feasibility Study for the
Glendale Study Area; North Plume Operable Unit (April 1992).
24
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-^
simple and inexpensive since it involves only groundwater
monitoring. As indicated by the baseline risk assessment for the
Glendale North OU presented in the RI Report for the Glendale Study
Area (January 1992), Alternative 1 could pose both carcinogenic and
non-carcinogenic risk if a person were exposed to the groundwater
from the upper zone of the aquifer. Loss of a valuable water
resource from continued degradation of the aquifer and discharge of
valuable water to the river is a major concern.
overall Protection of Human Health and the Environment, Short Term
Effectiveness and Long Term Effectiveness. Alternatives 2 through
7 are effective in the short-term and long-term in reducing the
risk to human health and the environment by removing contaminants
from the upper zone of the aquifer, by inhibiting further
downgradient and vertical contaminant plume migration, and by
reducing the toxicity, mobility, and volume of contaminants in the
aquifer. Alternatives 2 through 4 have the same effectiveness in
inhibiting downward and downgradient migration of the contaminant
plumes, in removing contaminant mass from the Upper Zone of the
aquifer, and in reducing the discharge of contaminated groundwater
to the Los Angeles River. During the first 12 years of operation,
Alternatives 2 through 4 are estimated to remove approximately 82
percent of the total estimated initial TCE mass, and may reduce the
maximum TCE concentration remaining in the upper zone of the
aquifer by as much as 88 percent.
Alternative 6 is effective in inhibiting downward and
downgradient migration of the contaminant plumes, in removing
contaminant mass from the upper zone of the aquifer, and in
reducing the discharge of contaminated groundwater to the Los
Angeles River. Because Alternatives 6 involves recharge at the
Headworks Spreading Grounds which would push a portion of the
contaminant plume located upgradient of the extraction sites
towards the extraction wells, this alternative may remove slightly
more mass (86 percent of the estimated initial TCE mass) than
Alternatives 2 through 4 (82 percent of the estimated initial TCE
mass). Alternative 6 also reduces the maximum TCE concentration
remaining in the Upper Zone of the aquifer by as much as 88
percent.
Alternatives 5 and 7 have the same effectiveness in inhibiting
downward and downgradient migration of the contaminant plumes and
in removing contaminant mass from the Upper Zone of the aquifer.
The extraction well configuration proposed in the FS report for
Alternative 5 is different from those proposed for Alternatives 2
through 6, in that three extraction sites are used instead of four,
to accommodate injection downgradient of extraction. Reinjecting
the treated groundwater may increase the discharge of contaminated
groundwater to the river near the injection wells in excess of the
discharge estimated in the no-action alternative. However, the
injection of 3,000 gpm of treated water would dilute the
contamination in the groundwater and decrease the contaminant
25
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concentration levels in the groundwater discharged to the Los
Angeles River. Other injection sites could be investigated during
the remedial design phase. The model estimates that approximately
89 percent of the initial estimated mass of TCE in the groundwater
would be removed during the first 12 years of operation.
Alternatives 5 and 7 reduce the maximum TCE concentration
remaining in the Upper Zone of the aquifer by as much as 86
percent. Although slightly more contaminant mass (89 percent
versus 82 and 86 percent for Extraction Scenarios 4 and 8,
respectively) is removed in this scenario due to the effects of
aquifer recharge, the TCE concentration remaining in the Upper Zone
is slightly higher. The higher TCE concentration is due to the
downgradient reinjection of the treated groundwater, which may tend
to restrict the remaining contaminant mass to a slightly smaller
area.
Reduction of Toxicity, Mobility and Volume through Treatment. The
VOC treatment technologies used in Alternatives 2, 4, 5, 6, and 7
(dual-stage air stripping with vapor-phase GAC adsorption and/or
liquid phase GAC adsorption) and used in Alternative 3 (perozone
oxidation followed by air stripping with vapor-phase GAC
adsorption) are technically feasible and effective in meeting ARARs
for VOCs in the extracted and treated groundwater. Treatment of
the extracted contaminated groundwater via dual-stage air stripping
with vapor-phase GAC adsorption and/or liquid phase GAC adsorption
would reduce substantially the toxicity and mobility of
contaminants in the aqueous phase. The adsorption of contaminants
onto the GAC would reduce the volume of contaminated media.
However, a substantially larger quantity of contaminated GAC media
would be generated with the dual-stage air stripping system
compared to perozone oxidation (which is a destructive technology)
followed by air stripping with vapor-phase GAC adsorption. This
contaminated GAC would require disposal or regeneration.
Treatment of the extracted contaminated groundwater via
perozone oxidation followed by air stripping with vapor-phase GAC
adsorption would destroy greater than 90 percent of the VOCs, and
generate a smaller quantity of contaminated GAC media compared to
dual-stage air stripping. VOC treatment using perozone oxidation
has only been tested and applied in pilot-scale/limited
applications, and limited O&M data are available; however, a
demonstration-scale (2,000-gpm) facility has begun operation in
North Hollywood for treating TCE- and PCE-contaminated groundwater.
This prototype facility should provide useful information regarding
the long-term performance and O&M costs.
As a result of comments received during the public comment
period, EPA further evaluated the use of perozone oxidation for the
Glendale North OU. Additional research on perozone use and revised
cost estimates based on a bench scale treatability study can be
found in the following technical memorandum: Applicability of
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Perozone Treatment. Process for the Glendale North Operable Unit
Groundwater Remediation (March 12, 1993) included in Supplement 1
of the Administrative Record for the Glendale North OU available at
all five information repositories for the San Fernando Valley
Superfund sites. Carbon tetrachloride, which is one of the
contaminants found in the groundwater of the Glendale North plume,
is not as readily treated using the perozone process and must be
treated using air-stripping or liquid phase GAC to ensure that the
treated water will meet all drinking water standards for VOCs. In
addition, incomplete oxidation can lead to the formation of by-
products such as formaldehyde which would also need to addressed.
The bench scale treatability study found that the total present
worth cost estimated in the FS report is underestimated and
$500,000 or more could be added to the estimated $31,200,000.
These factors coupled with the uncertainties associated with
design,~capital and operational costs and reliability, and finally
the fact that a municipality will be receiving this water, all
combine to make Alternative 3 less preferable than Alternatives 2
and 4 through 7 which propose using air stripping or liquid phase
GAC for VOC treatment.
Compliance with ARARs. As discussed in the ARARs section (Section
10) of this ROD, since this remedial action is an interim action,
there are no chemical-specific ARARs for aquifer cleanup for any of
the alternatives. For Alternatives 2-7, the chemical-specific
ARARs for the treated water from the VOC treatment plant at this
site are Federal MCLs and more stringent State MCLs for VOCs.
Alternatives 2, 4, 5, 6 and 7 are expected to meet these ARARs for
the treated water. There is some uncertainty regarding the ability
of Alternative 3 to meet these ARARs because perozone has not been
used to treat such high concentrations of VOCs at such high flow
rates. Therefore, there could be problems unless the air stripping
unit proposed to follow the perozone system is a redundant
treatment system which would add substantially to the cost.
For the Alternatives that involve distribution of the treated
water to a public water supply system (Alternatives 2 and 3),
secondary drinking water standards are ARARs and will be met prior
to blending of the water for nitrate. For water that will be
served at the tap, all applicable requirements will have to be met
after blending, including the nitrate MCL. For Alternatives 6 and
7, the nitrate levels in the treated groundwater will meet ARARs by
ensuring that recharge of the treated groundwater (Alternative 6)
and reinjection of the treated water (Alternatives 5 and 7) occurs
where levels of these substances in the receiving aquifer are
similar to those in the treated water to be discharged, recharged
or reinjected. EPA has confirmed that nitrate levels in the
groundwater beneath the Headworks Spreading Grounds are similar to
the nitrate levels observed in the vicinity of proposed extraction
well sites. In Alternative 4, the treated water will meet MCLs
for VOCs prior to discharge to the Los Angeles River (which is on-
site) .
27
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For a more detailed discussion of ARARs please review Section
10 of this ROD .
Implementability. Technically and administratively. Alternatives
2, 3, 4 and 6 could be implemented. The technologies considered
for groundwater monitoring, extraction, and conveyance are proven
and have been applied extensively. For Alternative 6, the
availability of the Headworks Spreading Grounds for discharge of
extracted and treated groundwater would need to be addressed.
Technically, Alternatives 5 and 7 could probably be implemented,
but using ion exchange for nitrate treatment (Alternative 5) and
reinjection for treated groundwater disposal may pose some
technical and administrative feasibility issues. In particular,
disposing of the waste brine generated from backwashing the ion
exchange system may restrict the technical and administrative
feasibility of using ion exchange for nitrate treatment. Several
technical feasibility issues may arise when injecting treated
groundwater. At the location of the proposed reinjection sites,
the groundwater is approximately 30 feet below the ground surface;
thus, only a limited hydraulic head could be applied to induce
injection. Groundwater-injection pilot studies may be required
prior to full-scale application. In addition, other possible
locations for reinjection well placement can be proposed and
reviewed during the design phase.
EPA has determined that the treatment plants for the Glendale
North and Glendale South OUs will be combined. The total 5,000 gpm
of treated water will be conveyed to the City of Glendale for
distribution to its public water supply system. The exact
configuration of the combined treatment plant will be determined
during the remedial design phase of the project. The City of
Glendale has indicated that it has sufficient water credits and
capacity in their existing water system to accept this amount of
extracted treated water. Therefore, combining the treatment plants
for the Glendale North and South OUs would be implementable.
State and Public Acceptance. Based on comments received during the
public comment period, the State and the public generally expressed
support for Alternatives 2 through 7. In a letter dated June 16,
1992, the State (DTSC) expressed its concurrence with EPA's
preferred alternative presented in the Proposed Plan for the
Glendale North OU which is now EPA's. selected remedy for the
Glendale North OU. In a letter dated March 29, 1993, after
reviewing the Draft ROD for the Glendale North OU, DTSC stated that
it agreed with EPA's selected remedy for the Glendale North OU.
EPA received several comments from other State agencies, the City
of Glendale and members of the Glendale community specifically in
support of Alternatives 2 and 7. In a letter dated September 8,
1992, the Los Angeles Region of the Regional Water Quality Control
Board offered support for EPA's preferred alternative presented in
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the Proposed Plan for the Glendale North OU but requested to go "on
record" as favoring the direct use of the treated water as opposed
to reinjecting it.
One member of the public commented that he did not like
Alternative 2 and asked that EPA not include distribution to a
public water supply as a final use of the treated water.. The State
Water Resources Control Board, City of Glendale, and many other
commenters did not support Alternative 4, involving discharge to
the Los Angeles River. A few commenters including the City of
Glendale had a preference for Alternative 3, which proposes
perozone for VOC treatment. Comments received during the public
comment period along with EPA responses are presented in Part III
of this ROD, the Responsiveness Summary.
A public meeting was held in the City of Glendale on July 23,
1992, to discuss EPA's preferred alternative and the other
alternatives. At this meeting EPA gave a brief presentation
regarding the Proposed Plan, answered questions, and accepted
comments from members of the public.
At the public meeting and in a subsequent letter, the City of
Glendale emphasized that it would like to receive greater than
3,000 gpm of extracted, treated groundwater. The City also
indicated that it had stored water credits and water rights
sufficient to accept greater than 5,000 gpm of extracted, treated
groundwater from the San Fernando Valley. As a result of the
City's oral and written comments on the Glendale North OU, EPA has
determined that the treatment plants for the Glendale North and
South OUs shall be combined and the total 5,000 gpm of treated
water will be conveyed to the City of Glendale.
Cost. The estimated total present worth of Alternatives 2, 3, 4,
6, and 7 ranges from $28,200,000 to $38,700,000. The total present
worth costs for Alternative 2 fall within the middle of this range
at $36,400,000. The total present worth for Alternative 5 which
includes nitrate treatment using ion exchange is $61,400,000.
Using ion exchange for nitrate treatment adds significantly to the
cost of the alternatives.
EPA has determined that the treatment plants for the Glendale
North and Glendale South OUs will be combined. The total 5,000 gpm
of treated water will be conveyed to the City of Glendale for
distribution to its public water supply system. The exact
configuration of the combined treatment plant will be determined
during the remedial design phase of the project. The costs of the
two separate OU projects is. estimated to be $36,400,000 for
Glendale North and $25,020,000 for Glendale South. Therefore,
these two separate OU projects total $61,420,000. Recent EPA cost
estimates (included in Supplement 1 to the Glendale North OU
Administrative Record) indicate that combining the Glendale North
and South OUs could result in a cost savings of $13,888,000.
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Although the cost estimate for Alternative 2 is slightly
higher than some of the other alternatives, the estimated costs
presented here and in the FS do not take into account the value of
utilizing the groundwater resource as opposed to disposing of the
water in the Los Angeles River (Alternative 4) or reinjecting the
water back into the aquifer (Alternative 7).
10.0 APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
This section discusses Applicable or Relevant and Appropriate
requirements (ARARs) for the Glendale North OU. Under Section
121 (d) (1) of the Comprehensive Environmental Response, Compensation
and Liability Act of 1980 as amended by the Superfund Amendments
and Reauthorization Act of 1986 (collectively, CERCLA). 42 U.S.C.
§ 9621(d) remedial actions must attain a level or standard of
control~ of hazardous substances which complies with ARARs of
Federal environmental laws and more stringent state environmental
and facility siting laws. Only state requirements that are more
stringent than Federal ARARs, and are legally enforceable and
consistently enforced statewide may be ARARs.
Pursuant to Section 121(d) of CERCLA, the on-site portion of
a remedial action selected for a Superfund site must comply with
all ARARs. Any portion of a remedial action which takes place off-
site must comply with all laws legally applicable at the time of
the off-site activity occurs, both administrative and substantive.
An ARAR may be either "applicable", or "relevant and
appropriate", but not both. According to the National Oil and
Hazardous Substances Pollution Contingency Plan (NCP) (40 CFR Part
300) , "applicable" and "relevant and appropriate" are defined as
follows:
Applicable requirements are those cleanup standards,
standards of control, or other substantive environmental
protection requirements, criteria, or limitations
promulgated under Federal or state environmental or
facility siting laws that specifically address a
hazardous substance, pollutant, contaminant, remedial
action, location, or other circumstance found at a CERCLA
site. Only those state standards that are identified by
a state in a timely manner and that are more stringent
than Federal requirements may be applicable.
"Applicability" implies that the remedial action or the
circumstances at the site satisfy all of the
jurisdictional prerequisites of a requirement.
Relevant and appropriate requirements are those cleanup
standards, standard of control, and other substantive
environmental protection requirements, criteria, or
limitations promulgated under Federal environmental or
state environmental or facility siting laws that, while
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not "applicable" to a hazardous substance, pollutant,
contaminant, remedial action, location, or other
circumstance at a CERCLA site, address problems or
situations sufficiently similar to those encountered at
the CERCLA site that their use is well suited to the
particular site. Only those state standards that are
identified in a timely manner and that are more stringent
than Federal requirements may be relevant and
appropriate.
Chemical-Specific ARARs. Chemical-specific ARARs are health- or
risk-based concentration limits, numerical values, or methodologies
for various environmental media (i.e., groundwater, surface water,
air, and soil) that are established for a specific chemical that
may be present in a specific media at the site, or that may be
discharged to the site during remedial activities. These ARARs set
limits on concentrations of specific hazardous substances,
pollutants, and contaminants in the environment. Examples of this
type of ARAR are ambient water quality criteria and drinking water
standards.
Location-Specific ARARs. Location-specific requirements set
restrictions on certain types of activities based on site
characteristics. Federal and state location-specific ARARs are
restrictions placed on the concentration of a contaminant or the
activities to be conducted because they are in a specific location.
Examples of special locations possibly requiring ARARs may include
flood plains, wetlands, historic places, and sensitive ecosystems
or habitats.
Action-Specific ARARs. Action-specific requirements are
technology- or activity-based requirements which are triggered by
the type of remedial activities under consideration. Examples are
Resource, Conservation and Recovery Act (RCRA) regulations for
vaste treatment, storage or disposal.
Neither CERCLA nor the National Oil and Hazardous Substances
Pollution Contingency Plan (NCP) (400 C.F.R. Part 300) provides
across-the-board standards for determining whether a particular
remedy will result in an adequate cleanup at a particular site.
Rather, the process recognizes that each site will have unique
characteristics that must be evaluated and compared to those
requirements that apply under the given circumstances. Therefore,
ARARs are identified on a site-specific basis from information
about specific chemicals at the site, specific features of the site
location, and actions that are being considered as remedies.
The following section outlines the Applicable or Relevant and
Appropriate Requirements (ARARs) that apply to this site.
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10.1 Chemical-Specific ARARs
10.1.1 Federal Drinking Water Standards
Section 1412 of the Safe Drinking Water Act (SDWA^. 42 U.S.C.
S300g-l. "National Water Regulations"; National Primary Drinking
Water Regulations. 40 CFR Part 141.
EPA has established Maximum Contaminant Levels (MCLs) (40 CFR
Part 141) under the Safe Drinking Water Act (SDWA) to protect
public health from contaminants that may be found in drinking water
sources. These requirements are applicable at the tap for water
provided directly to 25 or more people or which will be supplied to
15 or more service connections. The MCLs are applicable to any
water that would be served as drinking water. Under NCP Section
300.430ff) (5), remedial actions must generally attain MCLs and non-
zero Maximum Contaminant Level Goals (MCLGs) for remedial actions
where the groundwater is currently or potentially a source of
drinking water.
The Glendale North groundwater is a source of drinking water.
However, since the Glendale North OU remedial action is an interim
action, chemical-specific cleanup requirements for the aquifer such
as attaining MCLs and non-zero MCLGs, which would be ARARs for a
final remedy, are not ARARs for this interim action. (See 55 Fed.
Reg. 8755.) Nevertheless, EPA has determined that for the
treatment plant effluent from the Glendale North OU, the Federal
Maximum Contaminant Levels (MCLs) for VOCs and any more stringent
State of California MCLs for VOCs are relevant and appropriate and
must be attained regardless of the end use or discharge method for
the treated water.
For the treated and blended water which will be put into the
public water supply, all applicable requirements for drinking water
in existence at the time that the water is served will have to be
met because EPA considers the blending facility and the serving of
the water to the public (at the tap) to be off-site. Complying
with all applicable requirements for drinking water at the tap will
also require attainment of the MCL for nitrate prior to serving the
water to the public. Since these are not ARARs, these requirements
are not "frozen" as of the date of the ROD. Rather, they can
change over time as new laws and regulations applicable to drinking
water change. See 55 Fed. Reg. 8758 (March 8, 1990). Figure 10-1
provides a diagram of the treatment chain and blending process for
the treated water prior to distribution of the treated and blended
water to the public water supply for Alternatives 2 and 3.
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ON-SITE
Treatment
Plant
I I I I I I I I I
Extraction
Wells
OFF-SITE
1. Point o! Delivery
to Water Purveyor*
Blending
Facilities
I ITT
Infection Wells
Must meet all ARARs
Must meet all legal requirements
Including MCL tor nitrate
2. Point ol Public
Water System
Introduction"
FIGURE 10-1: ON-SITE ARARS AND OFF-SITE LEGAL
REQUIREMENTS FOR THE GLENDALE NORTH OU
INTERIM REMEDY
SFO69208.06.01
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10.1.2 '""State Drinking Water standards
California Safe Drinking Water Act. Health and Safety Code.
Division 5. Part 1. Chapter 7. 54010 et sea.. California Domestic
Water Quality Monitoring regulations. CCR Title 22. Division 4,
Chapter 15. S64401 et sea.
California has also established drinking water standards for
sources of public drinking water, under the California Safe
Drinking Water Act of 1976, Health and Safety Code Sections
4010.l(b) and 4026(c). The State of California has promulgated
MCLs for primary VOCs. Several of the State MCLs are more
stringent than Federal MCLs. In these cases, EPA has determined
that the more stringent State MCLs for VOCs are relevant and
appropriate for the treatment plant effluent from the Glendale
North OU interim remedy. The VOCs for which there are more
stringent State standards include: benzene; carbon tetrachloride;
1,2-Dichloroethane (1,2-DCA); 1,1-Dichloroethene (1,1-DCE); cis-
1,2-DCE; trans-l,2-DCE; and Xylene. There are also some chemicals
where State MCLs exist but there are no Federal MCLs. EPA has
determined that these state MCLs are relevant and appropriate for
the treated water prior to discharge or delivery to the water
purveyor. The VOCs for which there are no Federal MCLs but for
which state MCLs exist include: 1,1-DCA; 1,1,2,2-
tetrachloroethane; and 1,1,2-Trichloroethane.
In a letter to EPA dated June 2, 1992, the California
Environmental Protection Agency, Department of Toxic Substances
Control (DTSC) stated that EPA should include a discussion
regarding "future State MCLGs and the cumulative hazard index and
how they will affect the use of treated groundwater as a drinking
water source." Water served as drinking water is required to meet
MCLs at the tap, not MCLGs. Therefore, EPA would generally not
expect a future change in an MCLG to affect the use of treated
groundwater as a drinking water source. The cumulative hazard
index is also not an ARAR. However, EPA does retain the authority
to require changes in the remedy if necessary to protect human
health and the environment, including changes to previously
selected ARARS. See 40 C.F.R. Sections 300.430(f)(1)(ii)(B)(1) and
300.430(f)(5)(iii)(C). If EPA receives new information indicating
the remedy is not protective of public health and the environment,
EPA would review the remedy and make any changes necessary to
ensure protectiveness.
EPA has also determined that the monitoring requirements found
in CCR Title 22 Sections 64421-64445.2 are relevant and appropriate
for any treated water which will be delivered to the City of
Glendale's Public Water distribution system. However, the
selection of these sections as ARARs involves only the requirements
that specific monitoring be performed. It would not include any
administrative requirements (such as reporting requirements) and
would also not include meeting substantive standards set within
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these sections since no such standards have been identified by the
State as being more stringent than Federal requirements. For the
off-site portion of this remedy, including the treated water after
blending, all applicable requirements would have to be satisfied
including the monitoring requirements in CCR Title 22 Sections
64421-64445.2.
Accordingly, the chemical-specific standards for the
groundwater extracted and treated under the Glendale North OU
interim remedy are the current Federal or State MCLs for VOCs,
whichever is more stringent.
10.2 Location-Specific ARARs
No special characteristics exist in the Glendale Study Area to
warrant location-specific requirements. Therefore, EPA has
determined that there are no location-specific ARARs for the
Glendale"North OU.
10.3 ActionSpecific ARARs
10.3.1 Clean Air Act. 42 U.S.C. S7401 et sea.
Rules and Regulations of the South Coast Air Quality Management
District
Glendale North OU treatment of VOCs by air stripping, whereby
the volatiles are emitted to the atmosphere, triggers action-
specific ARARs with respect to air quality.
The Clean Air Act regulates air emissions to protect human
health and the environment, and is the enabling statute for air
quality programs and standards. The substantive requirements of
programs provided under the Clean Air Act are implemented primarily
through Air Pollution Control Districts. The South Coast Air
Quality Management District (SCAQMD) is the district regulating air
quality in the San Fernando Valley.
The SCAQMD. has adopted rules that limit air emissions of
identified toxics and contaminants. The SCAQMD Regulation XIV,
comprising Rules 1401, on new source review of carcinogenic air
contaminants is applicable for the Glendale North OU. SCAQMD Rule
1401 also requires that best available control technology (T-BACT)
be employed for new stationary operating equipment, so the
cumulative carcinogenic impact from air toxics does not exceed the
maximum individual cancer risk limit of ten in one million (1 x 10~
5) . EPA has determined that this T-BACT rule is applicable for the
Glendale North OU because compounds such as TCE and PCE are present
in groundwater, and release of these compounds to the atmosphere
may pose health risks exceeding SCAQMD requirements.
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The substantive portions of SCAQMD Regulation XIII, comprising
Rules 1331 through 1313, on new source review are also ARARs for
the Glendale North OU.
The SCAQMD also has rules to limit the visible emissions from
a point source (Rule 401), which prohibits discharge of material
that is odorous or causes injury, nuisance or annoyance to the
public (Rule 402), and limits down-wind particulate concentrations
(Rule 403) . EPA has determined that these rules are also ARARs for
the Glendale North OU interim remedy.
10.3.2 Water Quality Standards for Reinjection and Discharges of
Treated Water to Surface Waters or Land
Federal Standards
The Safe Drinking Water Act provides Federal authority over
injection wells. The Federal Underground Injection Control Plan is
codified in Part 144 of 40 C.F.R and prohibits injection wells such
as those that would be located at the Site from (1) causing a
violation of primary MCLs in the receiving waters and (2) adversely
affecting the health of persons. 40 C.F.R. §144.12. Section
144.13 of the Federal Underground Injection Control Plan provides
that contaminated ground water that has been treated may be
reinjected into the formation from which it is withdrawn if such
injection is conducted pursuant to a CERCLA cleanup and is approved
by EPA. 40 C.F.R. §144.13. These regulations are applicable to
any Glendale North OU treated water that is reinjected into the
Glendale North groundwater.
The Resource Conservation and Recovery Act (RCRA) Section 3020
is also an action-specific ARAR. This section of RCRA provides
that the ban on the disposal of hazardous waste into a formation
which contains an underground source of drinking water (set forth
in Section 3020(a)) shall not apply to the injection of
contaminated groundwater into the aquifer if: (i) such injection is
part of a response action under CERCLA; (ii) such contaminated
groundwater is treated to substantially reduce hazardous
constituents prior to such injection; and (iii) such response
action will, upon completion, be sufficient to protect human health
and the environment. RCRA Section 3020(b).
State Standards
For any reinjection to the basin, including spreading, or
discharges to surface water that occur on-site, the reinjected or
discharged water must meet all action-specific ARARs for such
reinjection or discharge. The ARAR applicable to the recharged
(Alternative 6) or reinjected (Alternative 5 or 7) water is:
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~ The Los Angeles Regional Water Quality Control Board's
Water Quality Control Plan, which incorporates State
Water Resources Control Board Resolution Mo. 68-16,
"Statement of Policy with Respect to Maintaining High
Quality of Waters in California.11 Resolution No. 68-16
requires maintenance of existing State water quality
unless it is demonstrated that a change will benefit the
people of California, will not unreasonably affect
present or potential uses, and will not result in water
quality less than that prescribed by other State
policies.
EPA anticipates that there may be short-term discharges of
treated water to the Los Angeles River during the initial operation
of the VOC treatment plant and on certain other limited occasions.
The ARAR for any treated water that is discharged, on a short term
basis, to the Los Angeles River is the National Pollutant Discharge
Elimination System (NPDES) Program which is implemented by the
LARWQCB. In establishing effluent limitations for such discharges,
the LARWQCB considers the Water Quality Control Plan for the Los
Angeles River Basin (the "Basin Plan"), which incorporates
Resolution 68-16, and the best available technology economically
achievable (BAT). See. Cal. Water Code § 13263.
Since the RWQCB did not identify specific substantive
discharge requirements or technology standards for such temporary
discharges, EPA has reviewed the Basin Plan and considered BAT and
has made certain determinations for the short-term discharges to
the Los Angeles River. In order to comply with this ARAR, any
treated groundwater that will be discharged, on a short-term basis,
to the Los Angeles River on-site must be treated to meet Federal
MCLs or State MCLs for VOCs, whichever is more stringent.
The treated water will also contain nitrate. The Basin Plan
states that the level of nitrate shall not exceed 45 mg/1 in water
designated for use as domestic or municipal supply. According to
the Basin Plan, the Los Angeles River is not designated for
municipal or domestic water supply. Therefore, the 45 mg/1 is not
an ARAR for the short-term discharges associated with the Glendale
North OU.
EPA has also considered what BAT could be for such short-term
discharges. For on-site discharges, meeting the nitrate MCL
through treatment by ion exchange would result in complex technical
issues, such as disposal of waste brine, and would be very costly
given the temporary nature of such discharges. Therefore, EPA has
not identified ion exchange as the NPDES treatment standard for
such short-term discharges.
EPA also considered the Mineral Quality Objective for the Los
Angeles River of 36 mg/1 (8 rog/1 nitrate-N) established in the
Basin Plan. Because the anticipated average concentration of
36
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-a »
nitrate in the short-term discharge is likely to be close to the
MCL, and any discharge would be short-term, there should not be any
significant long-term effects on the mineral quality of the Los
Angeles river associated with short-term discharges of VOC-treated
water from the Glendale North OU.
It should also be noted that extractions of 3,000 gpm of
groundwater per the Glendale North OU will result in decreased
amounts of contaminated groundwater recharging to the Los Angeles
River, thereby further protecting its beneficial uses.
Again, with respect to VOCs, any on-site discharge to the Los
Angeles River must meet Federal MCLs or State MCLs for VOCs,
whichever is more stringent. Since short-term discharges to the
Los Angeles River would occur on-site, the procedural requirements
for Federal National Pollution Discharge Elimination System (NPDES)
as implemented in RWQCB Waste Discharge Requirements (WDRs) issued
under Section 13263 of the California Water Code would not be
ARARs.
10.3.3 'Secondary Drinking Water Quality Standards
The State of California's Secondary Drinking Water Standards
(SOWS) are ARARs for the Glendale North OU if the final use option
involves serving treated groundwater as drinking water. 22 CCR
§64471. The California SOWS are selected as ARARs because they are
promulgated state standards and are relevant and appropriate to the
action of supplying the treated water to a public water supplier.
Although California SOWS are not applicable to non-public water
system suppliers, the California SOWS are relevant and appropriate
since the treated water under this action would be put into the
City's drinking water system action. Since the Federal SOWS are
not enforceable limits and are intended as guidelines, they are not
ARARs for this action. Furthermore, since the State SOWS are more
stringent than the Federal SDWS, EPA has not selected the Federal
SDV?S as requirements for this action. In summary, if the treated
water is to be served as drinking water, the treated water prior at
the point of delivery must meet the California SOWS. See Figure
10-1. If the treated water is reinjected or discharged to the
river, the water will not be required to meet State SDWS.
10.3.4 Resource Conservation and Recovery Act (RCRA) and Hazardous
Solid Waste Amendment (HSWA1 Standards. 42 U.S.C. SS6901-6987.
RCRA, passed by Congress in 1976 and amended by the Hazardous
and Solid Waste Amendments of 1984, contains several provisions
that are ARARs for the Glendale North OU. The State of California
has been authorized to enforce its own hazardous waste regulations
(California Hazardous Waste Control Act) in lieu of the Federal
RCRA Program administered by the EPA. Therefore, State regulations
in the California Code of Regulations (CCR), Title 22, Division
4.5, Environmental Health Standards for the management of Hazardous
37
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Wastes (hereinafter the State HWCL Regulations), are now cited as
ARARs instead of the Federal RCRA Regulations.
Since the source of the contaminants in the groundwater is
unclear, the contaminated groundwater is not a listed RCRA waste.
However, the contaminants are sufficiently similar to RCRA wastes
that EPA has determined that portions of the State's HWCL
Regulations are relevant and appropriate. Specifically, the
substantive requirements of the following general hazardous waste
facility standards are relevant and appropriate to the VOC
treatment plant for Alternatives 2 through 7: Section 66264.14
(security requirements), Section 66264.15 (location standards) and
Section 66264.25 (precipitation standards).
In addition, the air stripper would qualify as a RCRA
miscellaneous unit if the contaminated water constitutes RCRA
hazardous waste. EPA has determined that the substantive
requirements for miscellaneous units set forth in Sections
66264.601 - .603 and related substantive closure requirements set
forth in 66264.111 - .115 are relevant and appropriate for the air
stripper. The miscellaneous unit and related closure requirements
are relevant and appropriate because the water is similar to RCRA
hazardous waste, the air stripper appears to qualify as a
miscellaneous unit, and the air stripper should be designed,
operated, maintained and closed in a manner that will ensure the
protection of human health or the environment.
The land disposal restrictions (LDR), 22 CCR Section 66268 are
relevant and appropriate to discharges of contaminated groundwater
to land. The remedial alternatives presented do not include land
disposal of untreated groundwater. Because of the uncertainty in
the levels of contamination and volumes of water to be derived from
the development, purging and/or aquifer testing of monitoring
and/or extraction wells at the Glendale North OU, these waters must
be treated to meet Federal and State MCLs for VOCs, whichever is
more stringent, prior to discharge to land.
The container storage requirements in 22 CCR Sections
66264.170 -.178 are relevant and appropriate for the storage of
contaminated groundwater over 90 days.
On-site storage or disposal of the spent carbon from the
treatment system could trigger the State HWCL requirements for
storage and disposal if the spent carbon contains sufficient
quantities of hazardous constituents that cause the spent carbon to
be classified as a characteristic hazardous waste. If the spent
carbon is determined to be a hazardous waste under HWCA, the
requirements for handling such waste set forth in Sections 66262
and 66268 are applicable.
Certain other portions of the State's HWCL's regulations are
considered to be relevant but not appropriate to the VOC treatment
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plant. ""EPA has determined that the substantive requirements of
Section 66264.15 (general inspection requirements). Section
66264.15 (personnel training) and Sections 66264.30-66264.56
(Preparedness and Prevention and Contingency Plan and Emergency
Procedures) are relevant but not appropriate requirements for this
treatment system. EPA has made this determination because the
treatment plant will be required to have health and safety plans
and operation and maintenance plans under CERCLA that are
substantively equivalent to the requirements of Sections 66264.15,
66264.30-66264.56.
10.4 Summary of ARARs for the GlendaleJNorth OU Interim Remedy
EPA has determined a number of chemical-, and action-specific
ARARs for the Glendale North OU interim remedy. All of the
alternatives that involve groundwater extraction and treatment
could achieve the chemical-specific treatment standards for the
groundwater at the point of delivery (See Figure 10-1). However,
Alternative 3 which uses perozone is a less certain technology than
air stripping or liquid-phase GAC adsorption for such a large
volume of water and therefore is somewhat less likely to achieve
the chemical-specific ARARs.
11.0 THE SELECTED REMEDY
Based upon consideration of the requirements of CERCLA, the
detailed analysis of the alternatives, and public comments, EPA has
determined that Alternative 2: Extraction, Treatment of VOCs by
air stripping (either single- or dual-stage) or liquid phase GAC,
Blending to meet the nitrate standard and Conveyance to a public
water distribution system, in combination with Alternative 7 (as a
contingency): Extraction, Treatment of VOCs, and Reinjection, is
the most appropriate interim remedy for the Glendale North OU.
Alternative 2 includes the extraction of 3,000 gpm of
contaminated groundwater for 12 years. The extraction wells will
be new and will be located to inhibit most effectively the
migration of the contaminant plume while maximizing the extraction
of the most contaminated groundwater. The most contaminated
groundwater is located in the upper or shallowest zone of the
aquifer. Various locations and scenarios for extraction wells and
rates of extraction are proposed in the FS report for the Glendale
North OU; however, all design decisions for this interim remedy
will be made during the remedial design phase. During the remedial
design phase one of the locations proposed for extraction wells and
scenarios for rates of extraction per individual well may be
selected or new ones may be selected.
The extracted groundwater will be filtered to remove any
suspended solids, if necessary, and then treated for VOCs using
dual-stage or single-stage air stripping with vapor-phase GAC
adsorption for emissions control or liquid phase GAC may also be
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used. Whether air-stripping (dual versus single) or liquid phase
GAC will be used will be determined during remedial design as will
the exact location for the treatment plant (note that four possible
locations were proposed in the FS report). If air-stripping is
used for VOC treatment, the air stream will be treated using a
vapor-phase GAC adsorption system to ensure that air emissions meet
Federal air quality standards as regulated by the South Coast Air
Quality Management District and described in the ARARs section of
this ROD.
After the extracted groundwater is treated for VOCs, the
treated water exiting the treatment plant shall meet all MCLs and
secondary drinking water standards with the exception of nitrate.
The VOC-treated water will then be blended with water which does
not contain nitrate in excess of the nitrate MCL to reduce nitrate
levels to meet the nitrate MCL. The treated and blended water to
be delivered to a public drinking water supply shall meet all legal
requirements. The water will then be conveyed to the City of
Glendale and/or another municipality for distribution through the
public water supply system.
As a result of comments by the City of Glendale on the
Glendale North OU Proposed Plan (July 1992) and Glendale South OU
Proposed Plan (September 1992) which indicated that the City had
sufficient water credits to accept the treated water from both of
these OUs, and in order to decrease overall costs associated with
the OUs, EPA has determined that the treatment plants for the
Glendale North and Glendale South OUs will be combined. The total
5,000 gpjn of treated water will be conveyed to the City of Glendale
for distribution to its public water supply system. The exact
configuration of the combined treatment plant will be determined
during the remedial design phase of the project. The Glendale
South OU Record of Decision will also reflect this decision to
combine the treatment plants.
However, if the City of Glendale does not agree to accept the
treated water from both OUs (possibly due to water supply needs) or
if EPA determines that combining the treatment plants will
significantly delay or hinder the implementation of the Glendale
North OU, the treatment plants will not be combined.
EPA has selected Alternative 7, reinjection of the treated
water, as a contingency if the City of Glendale or another San
Fernando Valley water purveyor does not accept any or all of the
treated water. As a result, any remaining portion of water not
accepted by the City of Glendale will be: first, offered to another
San Fernando Valley water purveyor or second, reinjected into the
aquifer, per Alternative 7.
With the exception of blending to meet the nitrate MCL and
final use of the treated water, Alternative 7 is identical to
Alternative 2 above.
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After the extracted grouhdwater is treated for VOCs, the
treated water exiting the treatment plant shall meet all MCLs for
VOCs but will not need to meet secondary drinking water standards.
with the exception of nitrate. The VOOtreated water will then be
reinjected into the aquifer. To comply with ARARs, nitrate
concentrations in the water to be reinjected will have to be
similar to or lower than the levels of nitrate in the area of the
aquifer where the reinjection will occur.
Reinjection wells will be new wells and will be located such
that the effectiveness of inhibition of further downgradient
groundwater contamination migration and contaminant mass removal
from the aquifer are optimized, to the maximum extent practicable.
Locations and injection rates for injection wells are proposed in
the FS report for the Glendale North OU, however, all design
decisions for this interim remedy will be made during the remedial
design phase. During the remedial .design phase one of the
locations proposed for reinjection wells may be selected or new
ones may be selected.
Existing production wells that may provide pathways for
vertical migration of contamination will be abandoned or
rehabilitated, if required. While the Glendale North OU FS report
proposed several production wells be abandoned or rehabilitated,
these are only proposals. Again, final determinations regarding
which production wells will be abandoned and/or rehabilitated, if
any, will be made during remedial design.
Alternative 7 production well abandonment and/or
rehabilitation and monitoring well requirements are identical to
those discussed above for Alternative 2.
Groundwater monitoring wells shall be installed to evaluate
the effectiveness of the Alternative 7 interim remedial action for
the Glendale North OU. More specifically, groundwater monitoring
will be conducted no less frequently than quarterly to: 1) evaluate
influent and effluent water quality, 2) determine and evaluate the
capture zone of the extraction wells, 3) evaluate the vertical and
lateral (including downgradient) migration of contaminants, 4) to
evaluate the effectiveness of the reinjection well system and its
impact on the remedy and 5) to monitor any other factors associated
with the effectiveness of the Alternative 7 interim remedy
determined to be necessary during remedial design. Once the
Glendale North OU remedial action has been operating for six years,
monitoring frequency may be decreased to less than quarterly if
conditions warrant.
The VOC treatment plant of the Glendale North OU interim
remedy (whether it be Alternative 2, Alternative 7 or a combination
thereof) shall be designed and operated so as to prevent the
unknowing entry, and minimize the possible effect of unauthorized
entry, of persons or livestock into the active portion of the
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facility. One means of preventing unauthorized entry would be to
erect a perimeter fence around the VOC treatment plant. This fence
should be in place prior to initiation of the remedial action and
should remain in place throughout the duration of the remedy. The
VOC treatment plant shall also be designed and operated so as to
prevent releases of contaminated groundwater from the plant.
The selected remedy for the Glendale North OU meets all of
EPA's nine evaluation criteria. The selected remedy is equally
effective as the other alternatives in the short-term and long term
reduction of risk to human health and the environment by removing
contaminants from the upper zone of the aquifer, by inhibiting
further downgradient and vertical migration of the contaminant
plume, and by reducing the toxicity, mobility, and volume of
contaminants in the aquifer.
The selected remedy is estimated to remove approximately 82%
(Alternative 2) to 89% (Alternative 7) of the total estimated
initial TCE mass after 12 years of extraction, and may reduce the
maximum TCE concentration remaining in the upper zone of the
aquifer- by 88% or more. Thus, at the end of the 12 year interim
remedy, the maximum TCE concentration remaining in the upper zone
of the aquifer would be approximately 250 ug/1. The selected
remedy is estimated to significantly inhibit downgradient migration
of contaminated groundwater as well as vertical migration from the
upper to the lower zone of the aquifer. Vertical migration will be
further curtailed with the rehabilitation and/or abandonment of
inactive production wells screened in both the upper and lower
zones. Furthermore, the modeling conducted as part of the FS
indicated that the 3000 gpm extraction rate of the selected remedy
would be effective in inhibiting the discharge of contaminated
groundwater to the Los Angeles River by reducing groundwater levels
to below river bottom elevations.
The VOC treatment technologies selected (dual- or single-stage
air stripping with vapor phase GAC or liquid phase GAC) are
technically feasible and proven effective at meeting ARARs for VOCs
in the treated groundwater.
Alternative 2, in combination with alternative 7, could be
implemented, both technically and administratively. Other
alternatives which dispose of the water by spreading at the
Headworks Spreading Grounds may not be implementable because
Headworks is widely used and may not be available.
In a letter dated March 29, 1993, the State expressed
agreement with EPA's selected remedy. EPA received several public
comments during the sixty day public comment, the majority of which
expressed support for Alternative 2, primarily because this
alternative provides the treated water to a drinking water
purveyor. EPA's preferred alternative. These comments, along with
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EPA's "Responses are presented in Part III of this ROD, the
Responsiveness Summary.
The selected remedy is protective of human health and the
environment, meets ARARs, and unlike some other alternatives such
as Alternative 4 which includes discharge of the treated water to
the Los Angeles River, provides beneficial uses (distribution to a
public water supply and/or reinjection) for the treated water. The
selected remedy is cost-effective. The estimated cost of
Alternative 2 has a total present worth of $36,400,000, which is in
the middle of the range for all seven alternatives and this cost
would be significantly reduced by combining the treatment plants
for the OUs (based on a total cost savings of up to $13.8 million
for both OUs) . The estimated total cost of Alternative 7 is
$38,700,000, which is higher than Alternative 2 but significantly
less than Alternative 5, the most expensive alternative proposed.
As discussed in Section 10 (ARARs), Alternative 5 exceeds the
chemical-specific ARARs because it involves treatment of nitrate by
ion exchange.
12.0 STATUTORY DETERMINATIONS
As required under Section 121 of CERCLA, the selected interim
remedial action is protective of human health and the environment,
complies with Federal and State requirements that are legally
applicable or relevant and appropriate to the interim remedial
action, and is cost effective. The selected remedy utilizes
permanent solutions and alternative treatment technologies to the
maximum extent practicable and satisfies the statutory preference
for remedies that employ treatment to reduce toxicity, mobility,
and volume as a principal element.
The selected interim remedial action is protective of human
health and the environment in that it removes a significant VOC
contaminant mass from the upper zones of the aquifer and inhibits
further downgradient and vertical migration of contaminated
groundwater.
The VOC treatment technologies selected (dual- or single-stage
air stripping with vapor phase GAC or liquid phase GAC) are
technically feasible and proven effective at meeting ARARs for VOCs
in the treated groundwater and the air.
The selected remedy permanently and significantly reduces the
toxicity, mobility, and volume of hazardous substances in the
aquifer as well as the extracted groundwater.
Because this remedy will result in hazardous substances
remaining on-site above health-based levels, EPA shall conduct a
review, pursuant to CERCLA Section 121, 42 U.S.C. Section 9621, at
least once every five years after commencement of remedial action
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to ensure that the remedy continues to provide adequate protection
of human health and the environment.
13.0 DOCUMENTATION OF SIGNIFICANT CHANGES
The only significant change to the Glendale North OU interim
remedy proposed in the Proposed Plan fact sheet dated July 1992
involves the volume of water to be conveyed to the City of
Glendale.
As a result of oral comments at the Glendlae North OU Proposed
Plan public meeting as well as written comments by the City of
Glendale on the Glendale North OU Proposed Plan (July 1992) and
Glendale South OU Proposed Plan (September 1992) which indicated
that the City had sufficient water credits to accept the treated
water from both the Glendale North and Glendale South OUs, and in
order to decrease overall costs associated with the OUs, EPA has
determined that the treatment plants for. the Glendale North and
Glendale South OUs will be combined. The total 5,000 gpm of
treated water will be conveyed to the City of Glendale for
distribution to its public water supply system. The exact
configuration of the combined treatment plant will be determined
during the remedial design phase of the project. The Glendale
South OU Record of Decision will also reflect this decision to
combine the treatment plants.
However, if the City of Glendale does not agree to accept the
treated water from both OUs (possibly due to water supply needs) or
if EPA determines that combining the treatment plants will
significantly delay or hinder the implementation of the Glendale
North OU, the treatment plants will not be combined and only the
extracted treated water from the Glendale North OU will be conveyed
to the City of Glendale for distribution to its public water supply
system. As a further contingency, if the City of Glendale does not
accept any or all of the treated water, any remaining portion of
water will be 1) offered to another San Fernando Valley water
purveyor or 2) reinjected/recharged into the aquifer.
The impact of this change is that an additional 2,000 gpm of
treated water would be provided to the City. In its comments to
EPA on both the Glendale North and South OU Proposed Plans, the
City indicated that it would be able to accept the additional
treated water. The cost of construction and operation and
maintenance of the combined treatment plant is expected to be less
than the cost of construction and operation and maintenance of
individual treatment plants. Recent EPA cost estimates indicate
that as much as $13,888,000 would be saved on the total present
worth cost by combining the two treatment plants.
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PART III. RESPONSIVENESS SUMMARY
For Public Comments received during the Public Comment Period
for the Glendale North Operable Unit Interim Remedy
at the San Fernando Valley Superfund Site
Los Angeles County/ California
EXECUTIVE SUMMARY
This Responsiveness Summary addresses comments received from
the public, state agencies, and local agencies on EPA's proposed
interim cleanup plan for the Glendale North OU. Comments from the
California Environmental Protection Agency, Department of Toxic
Substances Control (DTSC) on the RI report for the Glendale Study
Area, the Glendale North FS Report, and the draft Proposed Plan for
the Glendale North OU were received by EPA prior to issuing the
Proposed Plan and initiating the public comment period. DTSC's
'comments and EPA's responses are available for review in the
Administrative Record for the Glendale North OU and are not
included in this responsiveness summary.
EPA held a sixty day public comment period on the RI and FS
reports, Proposed Plan and other Glendale North OU Administrative
Record documents between July 6, 1992 and September 8, 1992. A
public meeting was held in Glendale on July 23, 1992.
Approximately 30 representatives of the community, state and local
agencies, and EPA attended the meeting. EPA staff made a
presentation on the Glendale North OU alternatives, including EPA's
preferred alternative, and answered questions. A transcript of the
meeting is included in the Supplement 1 to the Administrative
Record for the Glendale North OU.
EPA received comments orally from three members of the public
during the July 23, 1992 public meeting. The first commenter was
a representative of the City of Glendale. The City's comments
included a request for additional water (up to 12,000 gpm) and
their overall support of EPA's preferred alternative for the
Glendale North OU. EPA responded to this comment by stating that
the Glendale North OU remedy involves extractions of 3,000 gpm
only. However, EPA has since determined that the Glendale North
and South OUs will be combined and the extracted, treated water
will be conveyed to the City of Glendale. If this is accomplished,
an additional 2,000 gpm of extracted, treated water would be
provided to the City, for a total of 5,000 gpm.
The second commenter expressed an interest in seeing EPA
consider selecting Alternative 3 for the Glendale North OU interim
remedy. Similar comments were also made by the City of Glendale.
Alternative 3 involves treating VOC contamination using an
innovative technology called perozone (hydrogen peroxide and
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ozone)-i» EPA explained that this VOC treatment is not proven at
high flow rates (> 3,000 gpm), may be substantially more costly
than estimated and is not effective at treating some of the
Glendale North OU contaminants (e.g. carbon tetrachloride). Since
the final use of the treated water is distribution to a public
water supply system, EPA determined that selecting a proven
technology (e.g., air stripping or liquid phase GAC) was
preferable.
The third commenter expressed concern about using groundwater
from the lower zone of the aquifer for blending to meet the nitrate
MCL. The State also expressed this same concern to EPA in writing.
EPA explained that it shares these concerns because this water is
also likely to be contaminated and extracting it would likely
result in vertical migration of both VOC and nitrate contamination.
In addition, such extractions might interfere with the
effectiveness of the Glendale North OU remedy.
EPA also received nine letters containing comments from
interested community members, the City of Glendale, the California
Department of Health Services Office of Drinking Water (ODW), and
the Los Angeles Region of the California Regional Water Quality
Control Board (RWQCB). A tenth letter was received one day after
the close of the public comment period. The comments included in
the tenth letter were similar to those of earlier commenters and
thus EPA was able to address them. These letters are included in
Supplement l of the Glendale North OU Administrative Record.
One member of the public was concerned that extracting 3000
gpro of groundwater over a 12-year period would result in subsidence
and sink hole formation. EPA responded that subsidence is not
likely to occur as a result of Glendale North OU extractions.
Other commenters asked that EPA use the treated water only for
reclaimed water purposes and not for drinking water. EPA explained
that the treated water will be of a much higher quality than
reclaimed water and will meet all drinking water standards prior to
final use.
The City of Glendale's written comments were similar to those
presented orally at the public meeting.
The RWQCB expressed support for EPA's preferred alternative
and favors direct use of the treated water to reinjecting it. EPA
also prefers direct use of the treated water but will reinject any
remaining portion if a water purveyor cannot accept it. ODW stated
that it considers the perozone treatment process an experimental
one and that it should not be used for the Glendale North OU
interim remedy. EPA agreed with this comment. ODW also stated
that the City of Glendale must obtain a water supply permit. EPA
responded that the City will receive the treated water at the point
of delivery and thereafter the water will need to meet all offsite
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legal requirements, including permits for offsite actions, before
it is cbnveyed to the public water distribution system.
EPA also received numerous comments from ITT General Controls,
Inc. on several issues relating to the RI and FS documents and the
Proposed Plan for the Glendale North OU interim remedy. Most of
these comments criticized EPA for not justifying its decisions
including its preferred alternative selection, suggested that EPA
did not provide the proper supporting documentation and stated that
the interim remedy for Glendale North OU did not demonstrate
consistency with a permanent remedy for the San Fernando Valley
sites. EPA responded that the Glendale North OU is an interim
action and not a permanent remedy, that the RI/FS and remedy
selection were conducted in accordance with the NCP, applicable EPA
guidance, that an entire Administrative Record with supporting
documentation is available for review at the San Fernando Valley
information repositories, and finally that the Glendale North OU
interim remedy would not be inconsistent with nor preclude
implementation of any final remedy for the San Fernando Valley
sites.
The Responsiveness Summary is divided into two parts. Part I
focuses on EPA's responses to the concerns and major issues raised
by members of the local community including the City of Glendale.
Part II includes detailed responses to the comments received that
were more legal or technical in nature. Comments submitted by
State agencies are included in Part II.
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