United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R09-93/093
June 1993
&ER& Super-fund
Record of Decision:
San Fernando Valley Area 2
(Operable Unit 3), CA
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50272-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/ROD/R09-93/093
3. Reclpienfe Accession No.
4. TlUeandSubtite
SUPERFUND RECORD OF DECISION
San Fernando Valley Area 2 (Operable Unit 3), CA
Fourth Remedial Action
& Report Data
06/18/93
&
7. Aulhort»)
a Performing Organization Rcpt. No.
9. Performing Organization Nam* and Address
10 Prelect Task/Work Unit No.
11. Contract(C) or Grant(G) No.
(G)
12. Sponsoring Organization Name and Address
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
13. Type of Report & Period Covered
800/800
14.
15. Supplementary Notes
PB94-964523
ia Abstract (Limit: 200 words)
The San Fernando Valley Area 2 (Operable Unit 3) 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 3), CA
Fourth Remedial Action
Contaminated Medium: gw
Key Contaminants: VOCs (PCE, TCE), other organics (PAHs), metals (chromium), other
inorganics (nitrates)
b. (dsntlfiers/Opert€nded Terms
c COSATI Field/Group
ia Availability Statement
19. Security Class (This Report)
None
20. Security Class (This Peas)
None
21. No. of Pages
64
22. Price
(See ANSI-239.18)
SM Instruction* on ftever**
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-35)
Department of Commerce
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EPA/ROD/R09-93/093
San Fernando Valley Area 2 (Operable Unit 3), CA
Fourth Remedial Action
Abstract (Continued)
Areas 1, 2, 3, and 4, respectively. EPA has preliminarily identified twelve facilities
that are located in the vicinity of the Glendale Study Area (South 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 South Study
Area, which includes the South Plume of VOC contamination and adjacent areas where
contamination is known or believed to have migrated, as OU3. Another 1993 ROD addresses
the Glendale North Study Area, as OU2. 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 PCE and TCE; other organics,
including PAHs; metals, including chromium; and other inorganics, including nitrates.
The selected interim remedial action for this site includes installing new extraction
wells in locations to most effectively inhibit the migration of the contaminant plume and
maximize extraction of the most contaminated ground water; extracting approximately 2,000
gpm of 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 GAC; using vapor-phase GAC adsorption for
emissions control, if air stripping is used; implementing a chromium reduction and
filtration unit to meet drinking water standards, if necessary; 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 water to the Glendale public drinking water
supply system or another municipal system; providing for a contingency remedy with no
nitrate treatment/blending and with recharge of the treated water into the aquifer at the
Headworks Spreading Ground for the treated ground water, if the City of Glendale or
another municipality does not accept any or all of the treated water; and installing
ground water monitoring wells to evaluate the effectiveness of the remedy. In order to
decrease cost, treatment, and delivery of treated water for the Glendale North and
Glendale South operable units will be combined. The estimated present worth cost for this
interim remedial action is $25,020,000, which includes an estimated annual O&M cost of
$1,852,000 for 12 years. Additional costs for chromium treatment, if necessary, include
an estimated present worth cost of $6,750,000, which includes an estimated annual O&M cost
of $611,000 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 South
OU are based on Federal MCLs for VOCs and any more stringent State MCLs for VOCs, and
include 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 SOUTH OPERABLE UKIT
RECORD 07 DECISION
PART I: DECLARATION
PART II: DECISION SUMMARY
PART III: RESPONSIVENESS SUMMARY
SAN FERNANDO VALLEY AREA 2 8UPERFUND 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 South OU Site
Characteristics 11
7.0 Summary of Site Risks 14
8.0 Description of Alternatives 20
9.0 Summary of Comparative Analysis
of Alternatives " 26
10.0 Applicable or Relevant and Appropriate
Requirements 30
11.0 The Selected Remedy 39
12.0 Statutory Determinations 42
13.0 Documentation of Significant Changes 43
Part III. Responsiveness Summary s 45
Executive Summary
Part I - Responses to Comments from the Local
Community (including the City
of Glendale)
Part II - Responses to Legal and Technical
Comments
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RECORD "OF DECISION
GLEKDALE SOUTH OPERABLE UNIT INTERIM REMEDY
PART I. DECLARATION
SITE NAME AND LOCATION
San Fernando Valley Area 2
Glendale South Operable Unit
Los Angeles County, California
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action
for the Glendale South 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 May 28, 1993 the State of California
agreed with the selected remedy for the Glendale South 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, nay 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 South plume of
groundwater contamination in the Glendale Study Area. This interim
remedy is referred to as the Glendale South 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 objectives for the
Glendale South OU:
o To inhibit vertical and horizontal migration of
groundwater contamination in the South Plume of the
Glendale Study Area; and
o To begin to remove contaminant mass from the upper zone
of the aquifer in the South Plume of the Glendale Study
Area.
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 will be
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extracted at a rate of 2,000 gallons per minute (gpm) for 12 years
from new wells to be installed 'in the South Plume of 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 to best meet the
objectives of the remedy. After treatment to remove VOCs, the
water will be blended as necessary with an alternative water source
of a quality such that the treated, blended water would meet all
drinking water standards (including the nitrate MCL). 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. Groundwater
monitoring wells will be installed and sampled regularly to help
evaluate the effectiveness of the remedy.
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 at a single location. 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 North OU Record of
Decision will also reflect this decision to combine the treatment
plants.
However, if EPA determines that combining the treatment plants
will significantly delay or hinder the implementation of the
Glendale South 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 water will be: 1) offered to another San
Fernando Valley water purveyor or 2) recharged into the aquifer at
the Headworks Spreading Grounds.
The total duration of the Glendale South 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.
The remedial action for the Glendale South OU represents a
discrete element in the overall long-term remediation of
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groundwater in the eastern portion of the San Fernando Valley. The
objectives of this interim action (i.e. inhibiting vertical and
horizontal migration of groundwater contamination and beginning to
remove contaminant mass from the upper zone of the aquifer in the
South Plume of the Glendale Study Area) 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 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.
(/pun. 6. /1.
John t/Wise Date
Acting Regional Administrator
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PART II. DECISION SUMMARY
This Decision Summary provides an overview of the Glendale
South OU. interim remedy, including a description of the nature and
extent of contamination to be addressed and 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 1-1). 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
1-2). 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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contaminants. The Glendale North and South Plumes are separated by
an area of groundwater with lower concentrations of contamination.
the Glendale South OU includes the South Plume of VOC contamination
and adjacent areas where contamination is known or believed to have
migrated. The Glendale South OU extends south towards the Pollock
Operable Unit. Some of the monitoring wells constructed to help
define the extent of the Pollock Ou are located within the Glendale
South OU.
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 of the: 1) high
concentrations of TCE and PCE present in groundwater, 2) critical
loss of groundwater production in the Glendale area and 3)
potential impact of 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 South OU which evaluated
a range of cleanup alternatives for addressing the contaminated
groundwater. The FS report entitled feasibility Study for the
Glendale Study Area South Plume Operable Unit was completed in
August 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
using groundwater in the San Fernando Valley 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, Bur bank, and Glendale being taken out of
service. The primary contaminants of concern were and are the
solvents trichloroethylehe (TCE) and perchloroethylene (PCE), which
have been widely used in a variety of industries including
machinery decreasing, metal plating 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
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the list (Figure 2-1). Each 'site 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 Hollywood,
Crystal Springs, Verdugo, and Pollock sites, also referred to as
San Fernando Valley Areas 1, 2, 3, and 4, respectively. The EPA
has now shifted from defining the sites based on production wells
to managing it as one large site defined by the extent of the
contaminated plume of groundwater. 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. In addition, monitoring
well data gathered at individual facilities in the San Fernando are
included in the EPA database which is used to generate plume maps
of the basin.
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 ROD for each OU have been
interim measures. EPA has not yet selected a final remedy for the
entire San Fernando Valley.
The most prevalent groundwater contaminants in the Glendale
Study area 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 levels of 820 ppb of TCE and 220 ppb of PCE
were detected in shallow wells located in the south plume portion
of the Glendale Study Area. The MCL for both TCE and PCE is 5 ppb.
Nitrate, an inorganic contaminant, has been detected
consistently at levels in excess of the MCL (45 milligrams per
liter (mg/1), also referred to as parts per million (ppm) 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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SAN FERNANDO VA. JEY SUPERFUND SITE
San Gabriel Mountains
Mountains
NORTH
HOLLYWOOD
NPL SITE •—
A
Glendale
Study Area
CRYSTAL
SPRINGS
NPL SITE
Santa Monica
Mountains
POLLOCK
NPL SITE
NPL SITE
GROUNDWATER
BASIN BOUNDARY
FREEWAY
FIGURR 1-1
GLENDALE
STUDY AREA
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HEADWORKS
SPREADING
GROUNDS
TCE CONCENTRATION IN GROUNDWATER
POTENTIALLY EXCEEDING SOOO ug/l
TCE CONCENTRATION IN GROUNDWATER
POTENTIALLY RANGING PROM 500 ug/l TO 5000 U0/I
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 GROUNDWATER
POTENTIALLY RANGING FROM 5 ug/l (MCL) TO 50 ug/l
AREAS OF CURRENTLY
KNOWN TCE CONTAMINATION
IN THE GLENDALE STUDY AREA
QLENDALE 8TUOV AREA REMEDIAL INVESTIGATION
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SAN FERNANDO
VALLEY
NORTH
HOLLYWOOD
NPL SITE
SANTA U
SAN FERNANDO VALLEY STUDY AREA.
INCLUDING THE FOUR NATIONAL
PRIORITIES LIST (NPL) SITES
GLCNDAIC STUDY AREA
FIGURE 2-1
SITE LOCATION MAP
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It should be noted that the Cities of Glendale and Los Angeles
closely monitor the quality of drinking water delivered to
residents. The water served to 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 South OU FS report and subsequent
Proposed Plan were finalized in August 1992 and September 1992,
respectively. The Glendale North OU FS report was completed in
April 1992 and the Proposed Plan was completed in June 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 at one location 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
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design phase of the project. The Glendale North OU Record of
Decision also reflects this decision to combine the treatment
plants.
However, if EPA determines that combining the treatment plants
will significantly delay or hinder the implementation of the
Glendale South 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 water will be l) offered to another San
Fernando Valley water purveyor or 2) recharged into the aquifer at
the Headworks Spreading Grounds.
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 tinder CERCLA in conjunction
with the work 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 has issued preliminary notices of potential liability
(General Notice) for the Glendale South OU to nineteen parties to
date. These parties have been preliminarily identified as owners
and operators of twelve facilities located in the vicinity of the
South Plume of 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 S122 has
not yet been issued for the Glendale South OU.
8
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4.0 HIGHLIGHTS Of COMMUNITY PARTICIPATION
EPA's preferred, alternative, as well as five other
alternatives were described in EPA's Proposed Plan for the Glendale
South OU (September 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 several times for a total
comment period of 15 weeks (107 days) after EPA received requests
for extensions from members of the public. The public comment
period closed on January 19, 1993. EPA received over 250 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 October
21, 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.
During the public comment periods for the Glendale North and
Glendale South OUs, the City of Glendale provided comments
emphasizing that it would like to receive more than the 3,000 gpm
of extracted, treated groundwater proposed under the Glendale North
Proposed Plan. 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 comments on the Glendale North and
Glendale South OUs, and after evaluating the relative total cost of
a combined plant versus separate plants, 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.
A press release to announce the release of the Proposed Plan
was issued October 1, 1992. Notice of the public meeting as well
as the availability of the Proposed Plan was published in the Los
Angeles Daily News on November 4, 1992. An announcement of the
extension of the public comment period was published in the Los
Angeles Daily News on December 3, 1992. In addition, two newspaper
articles were written about the remedial investigation, the
feasibility study and the Proposed Plan for the Glendale south OU
including: Los Angeles Times - October 8, 1992 and Los Angeles
Daily News - October 22, 1992. A map of the Glendale South OU was
provided in the Proposed Plan and the various newspaper articles
described the area that would be impacted by the Glendale South OU.
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 activities to
address contamination at the 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 South OU
interim action, and to document other changes in the community
relations program.
5.0 SCOPE AND ROLE OF THE OPERABLE UNIT
The interim remedial action for the Glendale South 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 South OU are:
o To inhibit vertical and horizontal migration of
groundwater contamination in the South Plume of the
Glendale Study Area
o To begin to remove contaminant mass from the upper zone
of the aquifer in the South Plume of the Glendale study
Area.
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 South 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, see Figure 1-1). 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
10
-------
sampled to continue to monitor the nature and extent of the
groundvater 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 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-further-action alternatives.
EPA has also initiated 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)
Water-master 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 SOUTH OU SITE CHARACTERISTICS
Results of LADWP's groundwater monitoring programs conducted
from 1981 through 1987 revealed that TCE and PCE had contaminated
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 seven EPA monitoring wells located in the south
plume portion of the Glendale Study Area (vertical profile borings
11
-------
and cluster wells). These wells are: PO-VPB-Ol, PO-VPB-02, PO-VPB-
10, PO-COl-195, PO-C01-354, PO-C02-052, and PO-C02-205. Wells PO-
VPB-Ol, PO-VPB-02 and PO-VPB-10 were sampled initially .during
November 1989 and PO-VPB-Ol and PO-VPB-10 were resampled during
August and September 1990. The cluster wells PO-C01 and PO-C02 and
were sampled initially in September 1990, at the same time PO-VPB-
02 was resampled. The following discussion summarizes the results
of chemical analyses on the sampling events in August and September
1990.
In the four Upper Zone wells (the three PO-VPBs and PO-C02-052),
six VOCs were detected above Federal and/or State MCLs: carbon
tetrachloride; 1,2-Dichloroethane (1,2-DCA); 1,1-dichloroethene
(1,1-DCE); 1,1,2,2-tetrachloroethane; PCE; and TCE (see Table 6-
1). As reported in the FS Report for the Glendale South OU, TCE
was detected in three of the four Upper Zone wells in the south
plume at a maximum concentration of 820 ppb. PCE was also detected
in three of the four Upper Zone wells at a maximum concentration of
140 ppb (see Table 6-1, Figure 6-1 and Figure 6-2).
In the three Lower Zone wells (PO-COl-195, PO-C01-354 and PO-
C02-205), the only VOC detected was TCE at a maximum concentration
of 4 ppb.
Monitoring wells have been installed at industry facilities in
the Glendale south plume portion of the Glendale Study Area. These
include three wells at the A.G. Layne facility, seventeen wells at
the Philips Components facility and nine wel-ls at the former
Franciscan Ceramics facility. All of these wells are screened in
shallow groundwater and are discussed as Upper Zone wells.
Nine VOCs (benzene, toluene, total xylenes, 1,1-DCA, 1,1-DCE,
1,1,1-TCA, methylene chloride, PCE and TCE were detected above MCLs
at the A.G. Layne facility wells based on samples collected in July
1990. Samples collected in August 1990 at the Philips Components
wells show PCE, TCE, methylene chloride and vinyl chloride above
MCLs.
Four base, neutral, and acid extractable semi-volatile organic
compounds (BNAs), 2-methylnaphthalene, naphthalene, 2,4-
dimethyIphenol, and 2-methylphenol, were detected in the A.G. Layne
wells. Two BNAs, bis(2-ethylhexyl)phthalate and di-n-
octylphthalate, were detected in one of the Lower Zone EPA wells
(none in Upper Zone sampling). No State or Federal MCLs have been
promulgated for these compounds. No chlorinated pesticides or PCBs
were detected in the Upper or Lower Zones.
Nitrate has been detected at levels in excess of the MCL in
the some of the groundwater samples collected in the South Plume of
the Glendale Study Area (see Table 6-1, and Figure 6-3). Nitrate
was detected in all of the VPB and cluster wells at concentrations
ranging from 9.55 to 16.1 mg/1 (as nitrogen). The Federal MCL is
12
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TABLE 6-1
SUMMARY OF ALL DETECTED CONSTITUENTS IN THE UPPER ZONE RI WELLS
FOR THE SOUTH PLUME OU
(Page 1 of 2)
Constituent
MCL'
Minimum
Concentration
Maximum
Concentration
Number of
Wells With
Detects out of 4*
Volatile Organic Compounds (pg/l)
Carbon Tetrachloride
Chloroform
1,1-Dichloroe thane
1,2-DichloroeUune
1,1 -Dichloroethene
1,1,2,2-TetrachloroeJhuie
TetrachJoroethene (PCE)
1,1,1 -Trichloroethane (TCA)
Trichloroethene (TCE)
Semivolatile Organics (/ig/1)
2-Melhylnaphtbalene
Naphthalene
2,4-Dimethylphenol
2-Methylphenol
Priority Pollutant Metals (mg/1)
Arsenic
Chromium
Mercury
Nickel
Selenium
Silver
Zinc
Inorganic Compounds (mg/1)
Nitrate (as N)
Total Dissolved Solids (TDS)
By Addition
0.5
100«
5.0
0.5
6.0
1.0
5.0
200
5.0
..b
„»
k
0.05
0.05
0.002
_b
0.05
0.05
10
500
3
23
0.03
9.55
458
1
1
1
5
41
9
140
11
820
110
160
16
16
0.005
1.2
0.0004
0.06
0.007
0.005
0.051
3
I
3
16.1
693
4
4
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TABLE 6-1
SUMMARY OP ALL DETECTED CONSTITUENTS IN THE UPPER ZONE RI WELLS
FOR THE SOUTH PLUME OU
(Page 2 of 2)
Constituent
MCL'
Minimum
Concentration
Maximum
Concentration
• Number of
Wells With
Detects out of 4*
Radionudides (pCi/l)
Gross Alpha
Gross BeU
Radon
IS
50
_»
2.2 ± 2.5
5.0 ± 2.0
66 ± 4.1
4.5 ± 4.8
8.2 ± 1.7
480 ± 5.4
4
4
4
Note: Samples collected August and September 1990.
' Promulgated federal or state MCL, whichever is more stringent.
* No state or federal MCL promulgated.
• MCL is for the sum of trihalomethanes.
4 The shallow wells include PO-VPB-0!, PO-VPB-02, PO-VPB-10, and PO-C02-52.
-------
GLENOAKS BLVD
ICC CONCENTRATION IN GROUNOWATER POTCHTUILY
EXCEEDING 5000 ug/l
TCC CONCCNTRATION IN CROUNDWATER POTENTIALLY
RANGING FROM 500 ug/l TO 5000 ug/l
TCC CONCENTRATION IN CROUNOWATCR POTENTIALLY
RANGING FROM 100 ug/l TO 900 ug/l
Kt CONCENTRATION IN CROUNOWATCR POTENTIALLY
RANGING FROM SO ug/l TO 100 ug/l
TCC CONCCNTRATION IN GROUNDWATCR POTENTIALLY
RANGING FROM S ug/l (MCL) TO SO ug/l
LOS ANGELES RIVER (LINED)
LOS ANGELES RIVER (UNLINEO)
FIGURE 6-1
ESTIMATED EXTENT OF TCE CONTAMINATION
IN THE UPPER ZONE AT THE WATER TABLE
SEPT.-OCT. 1990
SOUTH PLUME OPERABLt UNIT
FEASIBILITY STUDY
-------
A
CS-VPB-02
ACS-VPB-10
GL-MW-02
A.G. LAYNE 3
PHC-MW-04
COLORADf BLVD
J
MONITORING WELL
CLUSTER WELL
VPB WELL
PCE CONCENTRATION IN GROUNOWATER POTENTIALLY
RANGING FROM 100 ug/l TO 500 ug/l
PCE CONCENTRATION IN GROUNDWATER POTENTIALLY
RANGING FROM 50 ug/l TO 100 ug/l
PCE CONCENTRATION IN GROUNDWATER POTENTIALLY
RANGING FROM 5 ug/l (MCL) TO 50 ug/l
LOS ANGELES RIVER (LINED)
LOS ANGELES RIVER (UNLINED)
FIGURE 6-2
ESTIMATED EXTENT OF PCE CONTAMINATION
IN THE UPPER ZONE AT THE WATER TABLE
SEPT.-OCT. 1990 ~~
0 1000 2000
i
FEET
SOUTH PLUME OPERABLE UNIT
FEASIBILITY STUDY
-------
GLENOAKS BLVD
A.C. LAYNE SITE
CLUSTER WELL
MONITORING WELL
nrj NITRATE (as N) CONCENTRATIONS
GREATER THAN 10 mg/l(MCL)
—— LOS ANGELES RIVER (LINED)
= LOS ANGELES RIVER (UNLINED)
tOOO 0 1000 2000
=35
FEET
FIGURE 6-3 I *"
ESTIMATED EXTENT OF NITRATE CONTAMINATION
IN UPPER ZONE
SEPT.-OCT. 1990
SOUTH PLUME OPERABLE UNIT
FEASIBILITY STUDY
-------
10 mg/1 for nitrate as nitrogen. Nitrate concentrations did not
exceed MCLs in any of the Lower Zone wells. 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.
From the sampling and analyses of the EPA wells, only one
metal (chromium) has been detected above the HCL (when field
filtering of samples occurred). No metals were detected in the
Lower Zone above the MCL. An analysis of these data was performed
by EPA's contractor to examine the likelihood that chromium was a
waterborne contaminant rather than a sampling artifact (i.e.,
residual particulates from well construction and development) was
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 South OU,
concluded that the metal exceedances were most likely the result of
sampling artifacts. EPA has continued to analyze groundwater
samples collected under the quarterly monitoring program for
priority pollutant metals. In a technical memorandum dated May 17,
1993 (available for review in the administrative record for
Glendale South), recent sampling of monitoring wells for metals is
summarized. Within the Glendale South OU, one well had chromium
levels above MCLs; total chromium was reported as high as 733 ppb
and bexavalent (dissolved) chromium as high as 182 ppb. This well
likely represents contamination from a local source that would not
impact extraction wells. However, if necessary, the extracted
groundwater will be treated for chromium if this contaminant
exceeds drinking water standard.
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 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
13
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available for review in EPA's Administrative Record for the
Glendale South OU.
In addition, analysis of hydrogeology and groundwater modeling
conducted during the RI for the Glendale Study Area showed 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 south plume of groundwater
contamination in the Glendale Study Area obtained by EPA during the
remedial investigation were 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 South
OU risk assessment are presented in the Remedial investigation
Report for the Glendale Study Area (January 1992) and in other
documents included in the Glendale South OU Administrative Record.
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
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 South OU was on human
health issues, rather than environmental issues.
The objective of the baseline risk assessment for the Glendale
South OU was to evaluate the human health and environmental risks
posed by the contaminated groundwater beneath the south 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
South OU risk assessment included the water quality information
from the PO-VPB wells (with the exception of PO-VPB-10 which is
outside the plume area), cluster wells, Philips Components wells,
Franciscan Ceramics wells, and A.G. Layne wells.
The risk assessment for the Glendale South 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 fPart A^ and Vol. 2 Ecological Assessment (USEPA,
1989), The Exposure Factors Handbook (USEPA, 1989), and Risk
Assessment Guidance for Superfund Human Health Risk Assessment.
14
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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: l) 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
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 less.
The baseline risk assessment for the Glendale South OU is
presented in Section 8.0 of the Remedial Investigation Report for
the Glendale Study Area (January 1992). 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
15
-------
aquifer of the Glendale South "plume groundwater contamination in
the Glendale Study Area. Although no production wellfields are
located in the area encompassed by the South Plume OU, the
potential exists for use of this groundwater as a source of
drinking water in the future.
Chemicals of potential concern for the Glendale South OU used
in the risk assessment calculations included: TCE; PCE; carbon
tetrachloride; 1,1-DCA; 1,2-DCA; 1,1-DCE; nitrate and others
including the metals arsenic and chromium. 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
South 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.
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.
Table 7-2 lists the wells in the Upper and Lower Zones that
were incorporated in the risk assessment. The concentrations of
contaminants in these wells used in the risk assessment are from
the August and September 1990 sampling for EPA wells (PO-VPBs and
PO-Cluster wells), from July 1990 sampling at A.G. Layne wells
(AGLs), from August 1990 sampling at Phillips Components wells
(PHCs), and March 1989 sampling at the Franciscan Ceramic wells
(FRCs). A compound was totally excluded if it was not detected in
any of these wells. Half of the detection limit was used if a
compound was not detected in a particular well.
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
South 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 two potential methods of exposure to water from
the upper and lower zones of the aquifer: (1) exposure during
16
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TABLE 7-1
COMPOUNDS OF POTENTIAL CONCERN INCLUDED IN THE QUANTITATIVE
RISK ASSESSMENT FOR THE GLENDALE SOUTH PLUME OU
Constituent
Upper
Zone
(YES/NO)
Lover
Zone
(YES/NO)
VOCs
Benzene
Carbon Tetrachloride
1t1-Dichloroethane
1,2-Dichloroethane
1,1-Dichloroethene
Ethylbenzene
Methylene Chloride
1,1,2,2-Tetrachloroethane
Tetrachloroethene
Toluene
1,1,1-Trichloroethane
Tr i ch1oroethene
Vinyl Chloride
Xylene, Total
Y
Y
Y
Y
Y
N
Y
Y
Y
Y
Y
Y
Y
Y
N
N
N
N
N
N
N
N
N
N
N
Y
N
N
BNAs
Bis(2-ethylhexyl)phthalate
Di-n-octylphthalate
2-Methylnaphthalene
Naphthalene
N
N
Y
Y
Y
Y
N
N
Priority Pollutant Metals
Arsenic
Chromium
Y
Y
N
N
Inorganics
Nitrate
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TABLE 7-2
SUMMARY OF MONITORING WELLS USED
ZN THE BASELINE RISK ASSESSMENT
FOR THE GLENDALE SOUTH PLUME OU
Aquifer Zone
Monitoring
Wells Included in Quantitative
Risk Evaluation
Upper PO-VPB-01
PO-VPB-02
PO-C02-52
AGL-MW-1 '
AGL-MW-2
AGL-MW-3
PHC-MW-01
PHC-MW-02
PHC-MW-03
PHC-MW-04
PHC-MW-05
PHC-MW-06
PHC-MW-07
PHC-MW-08
PHC-MW-09
PHC-MW-10
PHC-MW-11
PHC-MW-12
PHC-MW-13
PHC-MW-14
PHC-MW-15
PHC-OS-01
PHC-EW-01
FRC-OW-01a
FRC-OW-02a
FRC-OW-03a
FRC-OW-04a
FRC-OW-05a
FRC-WCW-01a
FRC-WCW-02a
FRC-WCW-03a
FRC-WCW-04a
Lower
PO-COl-195
PO-CO1-354
PO-CO2-205
a Results
nitrate
available only for priority pollutant metals and
-------
residential use and (2) exposure from discharge into the Los
Angeles River.
EPA included three potential exposure routes in the Glendale
North OU risk assessment: (1) drinking the groundvater during
residential use and (2) inhaling the chemicals in groundwater
vapors during showering. 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 South 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.
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.
A quantitative analysis for potential human exposures was
performed during the remedial investigation of the Glendale Study
Area. The groundwater quality data were used to calculate the
arithmetic mean and upper confidence limit (95 percent) of the
arithmetic mean for the upper zone and the lower zone of the South
Plume OU.
The methods and equations used to calculate the exposure due
to ingestion of drinking water and inhalation of vapors during
showering are described in Section 7.3.4 of the Remedial
Investigation Report for the Glendale Study Area (January 1992).
The results of the baseline risk characterization for the upper and
lower zones of the aquifer are summarized in Tables 7-3 and 7-4 of
this ROD. A summary of hazard index calculations for nitrate in
groundwater is included in Table 7-5 of this ROD. A detailed
discussion of the data presented in these tables is included in
17
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TABLE 7-3
SUMMARY OF RISK CHARACTERIZATION FOR THE
UPPER ZONE AQUIFER
FOR THE GLENDALE SOUTH PLUME OU
Exposure
Scenario
Adult
Ingest ion
Shower
Inhalation
Arithmetic
Mean1
8.00E-04
2.00E+01
l.OOE-03
2 . OOE+01
RME2
2.00E-03
7. OOE+01
4.00E-03
6. OOE+01
Maximum3
l.OOE-02
l.OOE+02
2.00E-02
9. OOE+01
Type of
Risk
Cancer Risk
Hazard Index
Cancer Risk
Hazard Index
Average Value
Reasonable Maximum Exposure. The highest, exposure that is reasonable expected to
occur at a site (95% upper confidence limit of observed concentrations).
The exposure scenario using the highest observed concentration in any monitoring well
in the south plume of groundwater contamination in the Glendale Study Area. EPA
considers this scenario to be unreasonably high.
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TABLE 7-4
SUMMARY OF RISK CHARACTERIZATION FOR THE
LOWER ZONE AQUIFER
FOR THE GLENDALE SOUTH PLUHE OU
Exposure
Scenario
Arithmetic
Mean1
Maximum2
Type of
Risk
Adult
Ingestion
2.OOE-05
2.00E-01
5.OOE-05
4.00E-01
Cancer Risk
Hazard Index
Shower
Inhalation
5.00E-07
l.OOE-01
8.00E-07
4.00E-01
Cancer Risk
Hazard Index
i
2
Average Value
The exposure scenario using the highest observed
concentration in any monitoring well in the south plume of
groundwater contamination in the Glendale Study Area. EPA
considers this scenario to be unreasonably high.
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TABLE 7-5
SUMMARY OF HAZARD INDEX CALCULATIONS
FOR NITRATE IN GROUNDWATER
FOR THE GLENDALE SOUTH FLUME OU
Aquifer Arithmetic
Zone Mean1 RME2 Maximum3
Upper 1E+00 2E+00 2E+00
Lower 4E-01 a 8E-01
Average Value
Reasonable Maximum Exposure. The highest exposure that is
reasonable expected to occur at a site (95% upper confidence
limit of observed concentrations).
The exposure scenario using the highest observed
concentration in any monitoring well in the south plume of
groundwater contamination in the Glendale Study Area. EPA
considers this scenario to be unreasonably high.
Not calculated due to small sample set.
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Section 8.0 of the RI Report.
The risk associated with ingestion of groundwater from the
upper zone found that the major contributors to the total risk
value are methylene chloride, arsenic, benzene, 1,1-DCE, vinyl
chloride, PCE and TCE, in descending order of risk contribution.
For shower inhalation risks, nethylene chloride is the most
significant contributor to the overall risk. Benzene, 1,1-DCE, and
TCE are secondary contributors.
As can be seen from Table 7-3, the total cancer risk values
for estimates of concentrations at point of exposure for this
pathway (i.e., ingestion of groundwater from the upper zone) are
8E-04, 2E-03, and 1E-02 for the arithmetic mean, upper bound 95
percent confidence interval, and the maximum concentrations in
groundwater, respectively. The total noncarcinogenic risk values
for estimates of concentrations at point of exposure for this
pathway are 2E+01, 7E+01, and 1E+02 for the arithmetic mean, upper
bound 95 percent confidence interval, and the maximum
concentrations in groundwater, respectively. The noncarcinogenic
risk values for exposure to nitrate in the upper zone is 2E+00, for
the upper bound 95 percent confidence interval, which exceeds the
benchmark of 1.0.
Table 7-3 also contains a summary of risk characterization for
inhalation of groundwater from the upper zone. The total
carcinogenic risk values for estimates for concentrations at point
of exposure for this pathway are 1E-03, 4E-03, and 2E-02 for the
arithmetic mean, upper bound 95 percent confidence interval, and
the maximum concentrations in groundwater, respectively. Methylene
chloride is the most significant contributor to the overall risk.
The total noncarcinogenic risk values for estimates of
concentrations at point of exposure for this pathway are 2E+01,
6E+01, and 9E+01 for the arithmetic mean, upper bound 95 percent
confidence interval, and the maximum concentrations in groundwater,
respectively. Benzene is the single most significant contributor
to the elevated hazard index.
Table 7-4 summarizes the risk characterization for the lower
zone aquifer. The total carcinogenic risk values for estimates for
concentrations at point of exposure for ingestions are 2E-05 and
5E-05 for the arithmetic mean and the maximum concentrations in
groundwater, respectively. TCE and bis(2-ethylhexyl)phthalate were
the only carcinogenic compounds detected in the lower zone carried
into the quantitative assessment for risk through ingestion. Of
these, bis(2-ethylhexyl)phthalate is the most significant
contributor to risk levels above 1E-06. The total noncarcinogenic
risk values for all three of the compounds quantified are below the
benchmark of 1.0 for the arithmetic mean and maximum concentrations
at point of exposure for ingestion of groundwater from the lower
zone. The noncarcinogenic risk values calculated for nitrate were
also below the benchmark of 1.0.
18
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TCE was the only carcinogenic compound detected in the lower
zone to be quantified for risk due to inhalation. The risk levels
for the estimates of concentrations for this pathway are 5E-07 and
8E-07 for the arithmetic mean and maximum values, respectively.
Both risk values are below 1E-06. The sum of noncarcinogenic risk
values for all three of the compounds quantified are below the
benchmark of 1.0 for the arithmetic mean and maximum concentrations
at point of exposure for inhalation of groundwater from the lower
zone.
The uncertainties associated with the Glendale South OU risk
assessment are discussed in detail in Section 8.6 of the Remedial
Investigation Report for the Glendale Study Area (January 1992).
In summary, the results of the human health portion of the
Glendale South 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 individual exposed to the
conservatively high conditions used in the risk assessment (eg,
consume two liters of untreated water every day over a 70-year
lifetime) would have an increased chance (1 in 500) of developing
cancer during their lifetime.
Environmental Risk Assessment
An ecological risk assessment was also performed for the
Glendale South OU to address the potential ecological risks to
flora and fauna in the area (see Section 8.7 of the Remedial
Investigation Report for the Glendale Study Area. January 1992).
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.
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 to the Los Angeles River. Discharge
occurs under rising water conditions in the aquifer due to lack of
production well pumping in this area. However, discharges are
expected to be infrequent, seasonal, and localized.
Given the present developed condition of the site and the
major exposure pathway consideration of contaminated groundwater,
19
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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 groundvater.
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 South Plume. The alternatives were developed to meet the
following specific cleanup objectives for the Glendale South OU:
o To inhibit vertical and horizontal migration of
groundwater contamination in the South Plume of the
Glendale Study Area
o To begin to remove contaminant mass from the upper zone
of the aquifer in the South Plume of the Glendale Study
Area.
All of the alternatives, with the exception of the "no action"
alternative (Alternative 1), 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
South Plume Operable Unit (August 1992).
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, six alternatives were evaluated using
nine specific criteria: 1) 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) Implementability, 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 South Plume.
The assessment draws upon the evaluation of short-term
effectiveness, long-term effectiveness, implementability, reduction
20
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of toxicity, nobility 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 South 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 South OU. All of the alternatives, except no
action, include groundwater extraction followed by treatment and
use as potable supply or disposal. Therefore, specific levels for
treatment of the contaminated water prior to disposal or to
delivery to the drinking water purveyor are chemical-rspecific and
action-specific ARARs for the Glendale South OU.
Lona-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 well the contamination has been contained
by the remedial action and what are the 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
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 South Plume and to
workers' health and safety during construction of the proposed
facilities and implementation of the interim remedy.
21
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Implementabi 1 ity; 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:.l) 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 South 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 CERCIA (USEPA, 1988). Capital costs include a
contingency of 20 percent of total field costs (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 five
alternatives were described in EPA's Proposed Plan for the Glendale
South OU (September 1992).
The Glendale South 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 2,000 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 2,000 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.
22
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With the exception of Alternative 1 - No Action, the six
alternatives analyzed and compared during the FS and presented in
the Glendale South OU FS report include four major elements: l)
extraction of contaminated groundwater at the rate of 2000 gpm, 2)
treatment of the VOCs, 3) treat/blend/no action for nitrates, and
4) one of three options for final use - distribution to a public
water supply system, spreading at an existing spreading grounds, or
discharge to the Los Angeles River (See Table 8-1). The major
elements of each of six alternatives are listed below.
Alternative l NO Action
Alternative 2 Extract/Treat VOCs (either air
stripping w/vapor-phase GAC or
liquid-phase GAC)/Blending for
Nitrate/Public Water Supply
Alternative 3 Extract/Treat VOCs (perozone)/
Blending for Nitrate/Public Water
Supply
Alternative 4 Extract/Treat VOCs (either air
stripping w/vapor-phase GAC or
liquid-phase GAC)/No nitrate
treatment/River
Alternative 5 Extract/Treat VOCs (either air
stripping w/vapor-phase GAC or
liquid-phase GAC)/Ion Exchange for
nitrate/Recharge at Headworks
Spreading Ground
Alternative 6 Extract/Treat VOCs (either air
stripping w/vapor-phase GAC or
liquid-phase GAC)/No nitrate
treatment/Recharge at Headworks
Spreading Grounds
The highlights of the six alternatives are summarized briefly
below. More detailed descriptions of the alternatives are
presented in the Feasibility Study for the Glendale Study Area
South Plume Operable Unit (August 1992).
Alternative l; 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
23
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TABLE 8-1
SUMMARY OF ALTERNATIVES
COMPONENTS
Groundwater
Extraction
Treatment
Final Use
CRITERIA
Effectiveness and
Permanence
Reduction of
Toricity, Mobility,
Volume through
Treatment
Compliance with
ARARs
Overall Protection
of Human Health
and Environment
(Human Health)
(Environment)
Implemenubility
(Technical)
ESTIMATED
COSTS
Total Capital Cost
Annual O&M
Total Present Worth
ALTERNATIVE 1
None
None
Monitor groundwater quality
Not effective in the short- or long-
term
No reduction of toricity, mobility, or
volume
Will not meet ARARs
Assuming no institutional controls,
increased 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
nake future remediation difficult
S211.000*
$109,000*
$769,000*
ALTERNATIVE 2
Extract 2000 gpm of groundwater.
Treat VOCs with either air stripping and vapor-
phase GAC or liquid-phase GAG
Meet nitrate MCL by blending.
Chromium treatment to be added if necessary.
Convey treated, blended water to water
purveyor.
EVALUATION
Inhibit vertical ud lateral initiation of
contaminant plume.
Significantly reduced contaminated groundwater
discharge to LA River.
Remove contaminant mass from aquifer.
Treated, blended groundwater would meet
drinking water standard*
Estimated to reduce TCE concentrations in the
aquifer from 200 ppb to less than 10 ppb after
12 years.
Removes 80% of the initial mass of TCE in the
aquifer.
Will meet ARARs.
Protective of human health.
Environmental degradation wfl] be reduced
because migration of groundwater containing
TCE concentrations inhibited and TCE mass
removed.
Can be implemented
$15^40,000'
$1,852,000*
$25,020,000*
ALTERNATIVE 3
Same as Alternative 2.
Treat VOCs with perozone
oxidation, amtnpping and
vapor-phase GAC
Same as Alternative 2.
Same as Ahenntive 2.
Same as Alternative 2.
Same as Alternative 2.
Same is Alternative 2.
Same as Alternative 2.
Same as Alternative 2.
Same as Alternative 2.
Same as Alternative 2.
Same as Alternative Z
Same as Alternative 2.
Same as Alternative 2.
Can be implemented.
Perozone oxidation only
proven in pDot-ccale tests.
$16,620,000*
$1,729,000*
$25,470,000*
* If chromium treatment is needed, additional capital costs are expected to be $2,950,000, additional annual O&M $611,000, and
additional total present worth costs $6,750,000.
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TABLE 8-1 (Continued)
SUMMARY OF ALTERNATIVES
ALTERNATIVE 4
Same as Alternative Z
Same as Alternative 2.
No nitrate treatment
Same as Alternative Z
Discharge treated water to Los Angeles
River.
Same as Alternative 2.
Same as Alternative 2.
Same as Alternative 2.
Treated grouniJwmtcr would meet drinking
water standards for VOCs and surface
discharge standards for nitrates.
Same as Alternative Z
Same as Alternative 2.
Same as Ahernative 2.
Same as Alternative 2,
Same as Alternative Z
Can be implemented. Administrative
concerns associated with objection to non-
beneficial use of water.
$10,611,000-
$1,384,000*
S17,700,000*
ALTERNATIVE 5**
Same as Alternative 2.
Same as Alternative 2.
Treatment of nitrate with ion exchange.
Same as Alternative Z
Discharge treated water to Headworks Spreading
Grounds.
• -
Same as Alternative 2.
Same as Alternative 2.
Same as Alterantive 2.
Treated groundwater would meet drinking water
standards for VOCs and nitrates.
Same as Alternative Z
Same as Alternative Z
Same as Alternative 2.
Same as Alternative 2.
Same as Alternative 2.
waste brine disposal from nitrate treatment facility
and availability of Headworks Spreading Grounds
$25,140400*
$2,464,000*
$37,750,000*
ALTERNATIVE 6
Same as Alternative 2.
Same as Alternative 2.
No nitrate treatment
Same as Alternative 2.
Same as Alternative 5.
Same as Alternative 2.
Same as Alternative Z
Same as Alternative 2.
Treated groundwater would meet
drinking water standards for VOOc and
recharge requirements.
Same as Alternative 2.
Same as Alternative 2.
Same as Alternative Z
Same as Alternative Z
Same as Alternative Z
Gin be implemented; one administrative
issue may be the availability of the
recharge.
$14,160,000*
$1,613,000*
$22,420,000*
* Alternative 5 was formerly Alternative 8 in the Feasibility Study for the Glendate Study Area: South Plume Operable Unit
(August 19921
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groundvater monitoring; no additional cleanup activities would be
conducted.
Alternative 2; EPA's Preferred Alternative; Extract/Treat(either
Air Stripping w/Vaoor-Phase GAG or Liquid-Phase GAC/Blend for
nitrates/Public Water System
Alternative 2 involves the extraction of 2,000 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 South 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. If necessary to meet drinking
water standards, a chromium reduction and filtration unit will be
added to the treatment train. The treated water will be blended
with water of a quality such that the treated, blended water would
meet all drinking water standards (including 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 water supply system. The 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 at a single location 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 and
configuration of the combined treatment plant will be determined
during the remedial design phase of the project. The Glendale
North OU Record of Decision will also reflect this decision to
combine the treatment plants. However, 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)
24
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recharged into the aquifer at the Headworks Spreading Grounds per
Alternative 6 (see description below).
If EPA determines that combining the treatment plants will
significantly delay or hinder the implementation of the Glendale
South OU, a separate Glendale South OU treatment plant will be
constructed and the water will be conveyed to another San Fernando
Valley water purveyor. Two of the possible locations for the
treatment plant in the Glendale South OU are proposed in the
Glendale South OUFS report* As a further contingency, if a
municipality or municipalities do not accept all or part of the
treated water from a separate Glendale South OU treatment plant
(possibly due to water supply needs), the extracted treated water
will be conveyed to the Headworks Spreading Grounds where it will
be recharged to the aquifer.
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
recharge 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; Extr act /Treat f Per ozone Oxidations/Blending for
Nitrates/Public Water System
Alternative 3 also requires the extraction of 2,000 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 either air stripping with vapor-
phase GAC adsorption for emissions control or liquid phase GAC.
Air stripping or liquid-phase GAC would be required to remove any
carbon tetrachloride in the extracted groundwater because the
perozone oxidation process alone does not effectively treat this
VOC. If necessary to meet drinking water standards, a chromium
reduction and filtration unit will be added to the treatment train.
Alternative 4i Extract/Treat (either Air Stripping w/Vapor-Phase
GAC or Liquid-Phase GAC)/No Nitrate Treatment/River
Alternative 4 also involves the extraction of 2,000 gpm of
contaminated .groundwater for 12 years, and the same treatment
methodology and the same groundwater monitoring requirements as
Alternative 2. As with Alternative 2, if necessary to meet
drinking water standards, a chromium reduction and filtration unit
will be added to the treatment train. However, rather than
25
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providing the treated water to a public water purveyor, the treated
water would be discharged to the Los Angeles River.
Alternative 51; Extract/Treat (either Air Stripping w/Vapor-Phase
GAC or Liquid-Phase GAC1/ion Exchange for Nitrates/Recharge at
Spreading Grounds
Alternative 5 also involves the extraction of 2,000 gpm of
contaminated groundwater for 12 years, and the same treatment and
monitoring requirements as Alternative 2. As with Alternative 2,
if necessary to meet drinking water standards, a chromium reduction
and filtration unit will be added to the treatment train.
Alternative 5 differs from Alternative 2 in that after treatment
for VOCs, the water 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 recharged at a spreading ground.
Alternative 6; Extract/Treat (either Air Stripping w/Vapor-Phase
GAC or Liquid-Phase GAP /No Nitrate Treatment/Recharge at Spreading
Grounds
Alternative 6 also involves the extraction of 2,000 gpm 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. As with Alternative 2, if necessary
to meet drinking water standards, a chromium reduction and
filtration unit will be added to the treatment, train. However,
unlike Alternative 2, the treated water would be recharged to the
aquifer at the Headworks Spreading Grounds. No blending or
treatment for nitrates would occur prior to recharge.
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-tern 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
simple and inexpensive since it involves only groundwater
monitoring. As indicated by the baseline risk assessment for the
Glendale South OU presented in the RI Report for. the Glendale Study
Area (January 1992), Alternative l could pose both carcinogenic and
1 Note: Alternative f5 as presented in this ROD was formerly
Alternative #8 in the feasibility Study for the Glendale Study
Area: South Plume Operable Unit (August 1992).
26
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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, 3, 4, 5, and 6 have the same effectiveness in the
short 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 contaminant migration;
and by reducing the toxicity, mobility, and volume of contaminants
in the aquifer. During the first 12 years of operation, these
alternatives are estimated to remove approximately 80 percent of
the total estimated initial dissolved-phase TCE mass, with a peak
TCE concentration of 10 ug/1 remaining in the Upper Zone of the
aquifer.
Reduction of Toxicity, Mobility and Volume through Treatment. The
VOC treatment technologies used in Alternatives 2, 4, 5, and 6
(either air stripping with vapor-phase GAC adsorption or liquid
phase GAC adsorption) and used in Alternative 3 (perozone oxidation
followed by either air stripping with vapor-phase GAC adsorption or
liquid-phase GAC) are technically feasible and effective in meeting
ARARs for VOCs in the extracted and treated groundwater. Treatment
of the extracted contaminated groundwater via air stripping with
vapor-phase GAC adsorption 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 either air stripping with vapor-phase GAC or liquid-
phase GAC systems compared to perozone oxidation (which is a
destructive technology) followed by either air stripping with
vapor-phase GAC adsorption or liquid-phase GAC. This contaminated
GAC would require disposal or regeneration.
Treatment of the extracted contaminated groundwater via
perozone oxidation followed by either air stripping with
vapor-phase GAC adsorption or liquid-phase GAC would destroy
greater than 90 percent of the VOCs, and generate a smaller
quantity of contaminated GAC media compared to air stripping with
vapor-phase GAC alone. 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.
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As a result of comments received during the public comment
period for the Glendale North OU, EPA further evaluated the use of
per02one oxidation for the Glendale South 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 Perozone Treatment Process for the
Glendale North Operable Unit Groundwater Remediation (March 12,
1993) included in the Administrative Record for the Glendale South
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
South 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 6 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 through 6, the chemical-
specific ARARs for the treated water from the VOC treatment plant
at this site are Federal NCLs and more stringent State MCLs for
VOCs. Alternatives 2, 4, 5, and 6 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 is the potential for not meeting
MCLs unless the air stripping or liquid-phase GAC unit following
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 5 and
6, the nitrate levels in the treated groundwater will meet ARARs by
ensuring that recharge of the treated groundwater occurs where
levels of these substances in the receiving aquifer are similar to
those in the treated water to be recharged or that the water will
be treated for nitrates prior to recharge. EPA has confirmed that
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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).
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, Alternative 5 could probably be implemented, but using
ion exchange for nitrate treatment poses 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.
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 public generally expressed support for
Alternatives 2 through 6. EPA received comments from the City of
Glendale and members of the Glendale community specifically in
support of Alternatives 2 and 6. Comments received during the
public comment period along with EPA responses are presented in
Part III of this ROD, the Responsiveness Summary. In a letter
dated May 28, 1993, the State (Cal-EPA) agreed with EPA's selected
remedy for the Glendale South OU. The State Water Resources
Control Board did not support Alternative 4 which involves
discharge to the Los Angeles River because this alternative does
not put the treated water "to beneficial use to the fullest extent
of which they are capable."
A public meeting was held in the city of Glendale on October
21, 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.
In their written comments during the public comment period for
the Glendale South Proposed Plan, the City of Glendale emphasized
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that it would like to receive, more than just the 3,000 gpm of
extracted, treated groundwater proposed for Glendale North and that
the City would accept the water from both North and South OUs. 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 comments on the Glendale North and South OUs and the
cost analysis discussed below, 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.
Cost. The estimated total present worth of Alternatives 2, 3, 4,
and 6 ranges from $17,700,000 to $25,470,000. The total present
worth cost for Alternative 2 is $25,020,000 . The total present
worth for Alternative 5 which includes nitrate treatment using ion
exchange is $37,750,000. Using ion exchange for nitrate treatment
adds significantly to the cost of the alternatives. If a chromium
reduction and filtration unit is found to be necessary to meet
drinking water standards this would add an estimated $6,750,000 to
the total present worth 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 would total $61,420,000. Recent EPA
cost estimates (included in the Glendale South OU Administrative
Record) indicate that combining the Glendale North and South OUs
could result in a total cost of $ 47,532,000, resulting in an
estimated cost savings of $ 13,888,000.
Although the cost estimate for Alternative 2 is slightly
higher than some of the other alternatives, these overall project
costs 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 recharging at the Headworks
Spreading Ground (Alternatives 5 and 6).
10.0 APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
This section discusses Applicable or Relevant and Appropriate
requirements (ARARs) for the Glendale South OU. Under Section
12l(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.
§ 962l(d) remedial actions must attain a level or standard of
control of hazardous substances which complies with ARARs of
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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 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
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
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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
waste 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.
10.1 Chemical-Specific ARARs
10.1.1 Federal Drinking Water Standards
Section 1412 of the Safe Drinking Water Act fSDWAi . 42 U.S.C.
S300cr-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 Hater 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
300.430(f) (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
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drinking water.
.. »•
The Glendale South groundwater is a potential source of
drinking water. However, since the Glendale South 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 South 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.
10.1.2 State Drinking Water Standards
California Safe Drinking Water Act. Health and Safety Code.
Division 5. Part 1. Chapter 7. S4010 et seq.. California Domestic
Water Quality Monitoring regulations. CCR Title 22. Division 4.
Chapter 15. S64401 et seq.
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). 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 South 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-l,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;
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1,1,2,2-tetrachloroethane; and * 1,1,2-trichloroethane.
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
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 South 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 South OU.
10.3 Action-Specific ARARs
10.3.1 Clean Air Act. 42 U.S.C. S7401 et seq.
Rules and Regulations of the South Coast Air Quality Management
District
Glendale South OU treatment of VOCs by air stripping, whereby
the volatiles are emitted to the atmosphere, triggers action-
specific ARARs with respect to air quality.
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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 South 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 South 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.
The substantive portions of SCAQMD Regulation XIII, comprising
Rules 1301 through 1313, on new source review are also ARARs for
the Glendale South 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 South OU interim remedy.
10.3.2 Water Quality Standards for Discharges of Treated Water
to Surface Waters or Land
State Standards
For any recharge to the basin, including spreading, or
discharges to surface water that occur on-site, the recharged or
discharged water must meet all action-specific ARARs for such
recharge or discharge. The ARAR applicable to the recharged
(Alternative 6) water is:
• The Los Angeles Regional Water Quality Control Board's
Water Quality Control Plan, which incorporates State
Water Resources Control Board Resolution No. 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
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present or potential uses, and will not result in water
quality less than that prescribed by other State
policies.
In order to comply with this State ARAR, any treated
groundwater that is recharged on-site will be treated to
concentrations below Federal MCLs or State MCLs for VOCs, whichever
is more stringent. In addition, any nitrate concentrations in the
water to be recharged will have to be similar to or lower than the
levels of these substances in the area of the aquifer where the
recharge will occur. The quality and quantity of the water to be
recharged, as well as the duration of the project, will be
considered with respect to the existing water quality.
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 S 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 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 mg/1 nitrate-N) established in the
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Basin Plan. Because the anticipated average concentration of
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 South OU.
It should also be noted that extractions of 2,000 gpm of
groundwater per the Glendale South 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
(SDWS) which are more stringent than the Federal Secondary Drinking
Water Standards shall be ARARs for the Glendale South OU if the
final use option involves serving treated groundwater. as drinking
water. 22 CCR $64471. The California SDWS 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 SDWS are not applicable
to non-public water system suppliers, the California SDWS are
relevant and appropriate since the treated water under this action
would be put into the City's drinking water system. Since the
Federal SDWS are not enforceable limits and are intended as
guidelines only, they are not ARARs for this action. Furthermore,
since the State SDWS are more stringent than the Federal SDWS, EPA
has not selected the Federal SDWS as requirements for this action.
In summary, if the treated water is to be served as drinking water,
the treated water prior to the point of delivery must meet the
California SDWS. See Figure 10-1. if the treated water is
recharged or discharged to the river, the water will not be
required to meet State SDWS.
10.3.4 Resource Conservation and Recovery Act fRCRA1 and Hazardous
Solid Waste Amendment fHSWAi 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 South 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
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ON-SITE
Treatment
Plant
I I I I I I I I I
Extraction
Wells
I
11
OFF-SITE
1. Point of Delivery
to Water Purveyor*
Blending
Facilities
I
Recharge at
Headwords
Spreading
Grounds
Must meet all ARARs
' Must meet all legal requirements
Including MCL for nitrate
2. Point of Public
Water System
Introduction"
FIGURE 10-1: ON-SITE ARARS AND OFF-SITE LEGAL
REQUIREMENTS FOR THE GLENDALE SOUTH OU
INTERIM REMEDY
SFO69210.04.02
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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
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 6: 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.ill-.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 or treated
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 monitoring and extraction wells at this site, these
waters must be treated to meet Federal and State HCLs for VOCs,
whichever is more stringent, prior to discharge to land. By
meeting the Federal and State MCLs for VOCs before spreading at the
Headworks Spreading Grounds, Alternative 6 will satisfy the RCRA
LDRs because the groundwater will no longer contain the listed
wastes when it is recharged.
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
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carbon is determined to be a hazardous waste under HWCA, the
requirements for handling suchvwaste 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
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 Glendale South OU Interim Remedy
EPA has determined a number of chemical-, and action-specific
ARARs for the Glendale South 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 6 (as a
contingency): Extraction, Treatment of VOCs, and Recharge at a
Spreading Ground, is the most appropriate interim remedy for the
Glendale South OU.
Alternative 2 includes the extraction of 2,000 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
South 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
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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 GAG
adsorption for emissions control (liquid phase GAC may also be
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. 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 of such a
quality that the treated, blended water .will meet all drinking
water standards (including 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 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
North OU Record of Decision also reflects this decision to combine
the treatment plants.
However, if EPA determines that combining the treatment plants
will significantly delay or hinder the implementation of the
Glendale South OU, the treatment plants will not be combined.
EPA has selected Alternative 6, recharge of the treated water
at the Headworks Spreading Ground, 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 (possibly due to water
supply needs). 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, recharged into the
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aquifer, per Alternative 6.
With the exception of blending to meet the nitrate MCL and
final use of the treated water, Alternative 6 is identical to
Alternative 2 above.
Under Alternative 6, after the extracted groundwater 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. The VOC-treated water will then be
recharged into the aquifer at a Spreading Ground. To comply with
ARARs, nitrate concentrations in the water to be recharged will
have to be similar to or lower than the levels of nitrate in the
area of the aquifer where the recharge will occur.
Groundwater monitoring wells shall be installed to evaluate
the effectiveness of the Alternative 2 or 6 interim remedial action
for the Glendale South 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 recharge well
system and its impact on the remedy and 5) to monitor any other
factors associated with the effectiveness of the interim remedy
determined to be necessary during remedial design. Monitoring
frequency may be decreased to less than quarterly if EPA determines
that conditions warrant such a decrease.
The VOC treatment plant of the Glendale South OU interim
remedy (whether it be Alternative 2, Alternative 6 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
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 South 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 80%
of the total estimated initial TCE mass after 12 years of
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extraction. Thus, at the end of the 12 year interim remedy, a
maximum TCE concentration of remaining in the upper zone of the
aquifer would be approximately 10 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. Furthermore, the modeling
conducted as part of the FS indicated that the 2000 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' 6, could be
implemented, both technically and administratively.
In a letter dated May 28, 1993, the State agreed with EPA's
selected remedy. EPA received several public comments during the
public comment period, the majority of which expressed support for
Alternative 2 primarily because Alternative 2 provides the treated
water to a drinking water purveyor. These comments, along with
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 recharge) for the treated water. The
selected remedy is cost-effective. The estimated cost of
Alternative 2 has a total present worth of $25,020,000, which is in
the middle of the range for all six alternatives but this cost
would be significantly reduced by combining the treatment plants
for the two OUs (total cost savings of up to $13.8 million for both
OUs). The estimated total cost of Alternative 6 is $22,420,000.
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.
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The selected interim remedial action is protective of human
health and the environment in that it removes 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
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 South OU interim
remedy proposed in the Proposed Plan fact dated September 1992
involves the volume of water to be conveyed' to the City of
Glendale.
As a result of oral comments at the public meetings and
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 North OU Record of Decision will also reflect this
decision to combine the treatment plants.
However, if EPA determines that combining the treatment plants
will significantly delay or hinder the implementation of the
Glendale South OU, the treatment plants will not be combined.
Also, 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) recharged into the aquifer.
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The impact of this change is that the City of Glendale will be
receiving 5,000 gpm of treated water. 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 South 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 South 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 South FS Report, and the draft Proposed Plan for
the Glendale South 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 South OU and are not
included in this responsiveness summary.
EPA held a 107-day public comment period on the RI and FS
reports, Proposed Plan and other Glendale South OU administrative
record documents between October 5, 1992 and January 19, 1993. A
public meeting was held in Glendale on October 21, 1992.
Approximately 25 representatives of the community, local agencies,
and EPA attended the meeting. EPA staff made a presentation on the
Glendale South OU alternatives, including EPA's preferred
alternative, and answered questions. A transcript of the meeting
is included in the Administrative Record for the Glendale South OU.
EPA received comments orally from three members of the public
during the October 21, 1992 public meeting.
EPA also received approximately 10 letters containing comments
from interested community members, the City of Glendale, and the
Los Angeles Department of Water and Power (LADWP). These letters
are included in the Glendale South OU Administrative Record.
EPA 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 South 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 South OU did not demonstrate
consistency with a permanent remedy for the San Fernando Valley
sites. EPA responded that the Glendale South 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
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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 South 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 (by
ITT) that were more legal or technical in nature.
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