SDMS DOCID# 1140256
FIRST FIVE-YEAR REVIEW REPORT FOR
SAN GABRIEL VALLEY AREA 1 SUPERFUND SITE
South El Monte Operable Unit (SEMOU, OU5)
Richwood Operable Unit (ROU, OU3)
Suburban Operable Unit (SOU, 0U4)
Whittier Narrows Operable Unit (WNOU, OU2)
EI Monte Operable Unit (EMOU, OU1, OU08, and OU09)
LOS ANGELES COUNTY, CALIFORNIA
• •
PREPARED BY
United States Environmental Protection Agency
Region 9
San Francisco, California
Approved by:
Date:
Kathleen Salyer
Assistant Director
Superfund Division
CA Site Cleanup Branch
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Executive Summary
This is the first Five-Year Review (FYR) of the San Gabriel Valley Area 1 Superfund Site (the Site)
located in Los Angeles County, California (see Figure 3-1). The purpose of this FYR is to review
information to determine if the remedy is and will continue to be protective of human health and the
environment. The triggering action for this FYR was the signing of the South El Monte Operable Unit
(OU) Cooperative Agreement between the United States Environmental Protection Agency (EPA) and
the San Gabriel Basin Water Quality Authority (WQA) on August 7, 2008 (EPA, 2008a), which
funded the South El Monte OU remedy. This FYR discusses the South El Monte, Richwood,
Suburban, Whittier Narrows, and El Monte OUs at the Area 1 Site. The Area 1 Site addresses multiple
commingled plumes of groundwater contamination. The contamination originates at various industrial
facilities and extends through portions of the cities of South El Monte, El Monte, Temple City, and
Rosemead in Los Angeles County, California. The depth to groundwater in the Area 1 Superfund Site
ranges from approximately 15 to 100 feet. The groundwater is contaminated with volatile organic
compounds (VOCs), perchlorate, n-nitrosodimethylamine (NDMA), and 1,4-dioxane.
This FYR addresses the South El Monte, Richwood, and Suburban OUs. The report also describes the
Whittier Narrows and El Monte OUs to a lesser extent, because a separate FYR was completed for
Whittier Narrows OU in July 2011 and the selected remedy for the El Monte OU is still under
construction. Separate Records of Decision (RODs) were prepared for each OU, selecting separate
remedies.
South El Monte OU
In September 2000, EPA prepared an Interim Record of Decision (IROD) that selected an interim
groundwater pump-and-treat remedy for South El Monte OU to protect human health and the
environment. An Explanation of Significant Differences (ESD) was signed in 2005, which
incorporated the addition of perchlorate treatment as a necessary component of the interim remedy.
The major components of the South El Monte OU interim remedy are four separate groundwater
pump-and-treat systems operated by three water purveyors: the City of Monterey Park (MP), Golden
State Water Company (GSWC), and San Gabriel Valley Water Company (SGVWC). The systems
include the following:
• Multiple water supply wells used as remedial groundwater extraction wells, for which rates and
locations were selected during the remedial design process
• Water treatment equipment capable of removing VOCs from contaminated groundwater
• Conveyance systems including pipelines and booster pumps to transport contaminated
groundwater from the extraction wells to the treatment plants, and to transport treated water from
the plant to the water distribution systems of the three water purveyors
• Monitoring wells to help assess remedy performance
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Initial work on the water purveyor treatment facilities started before EPA prepared the South El Monte
OU IROD and continued in various stages through mid-2006. By the time remedy implementation
began under the Cooperative Agreement in October 2008, all of the primary construction activities had
been completed by the water purveyors.
Richwood OU
In May 1984, EPA selected initial remedial measures (IRMs) for a portion of the Area 1 Superfund
Site that later became the Richwood OU. The intent of the IRMs was to develop an alternative water
supply or a treatment system to enable three local water purveyors - Richwood Mutual Water
Company (RMWC), Hemlock Mutual Water Company (HMWC), and Rurban Homes Mutual Water
Company (RHMWC) - to supply drinking water with levels of tetrachloroethene (PCE) contamination
below the EPA Suggested No Adverse Response Level (SNARL) of 4 micrograms per liter ((.ig/L).
Ultimately, EPA only constructed a treatment system for RMWC. The treatment plant for RMWC
became operational on January 15, 1992. In March 1994, the California Department of Toxic
Substances Control (DTSC) assumed operations and maintenance (O&M) responsibility for the
treatment plant. In November 1994, DTSC shut down the treatment plant and entered into an
agreement with SGVWC to provide domestic water supply to the residents that previously had been
served by RMWC. SGVWC has continued to provide water since that time. The RMWC treatment
system was removed, the two production wells were destroyed, and SGVWC acquired RMWC's
assets in March 1999. HMWC and RHMWC continue to supply water to their customers in the
Richwood OU. EPA is considering partial deletion of the Richwood OU from the Area ISite listing on
the National Priorities List (NPL) because no further response action is warranted.
Suburban OU
In September 1988, EPA selected a remedy for the Suburban OU that was intended to partially control
the movement and spread of contaminants in the Whittier Narrows area of the San Gabriel Valley and
to address the potential public health threat posed by contaminants in the Suburban Water Systems
(SWS) Bartolo Well Field. The Suburban OU, also referred to as SWS Bartolo Well Field, consisted
of four water supply wells (201W-2, 201W-4, 201W-5, and 201W-6). In 1993, EPA amended the
remedy by changing the treatment level from 1 (ig/L to the newly established primary drinking water
maximum contaminant level (MCL) of 5 (ig/L for PCE, and delaying construction of a treatment
system because contaminant concentrations remained below MCLs. PCE concentrations in the
Bartolo Well Field have continued to be well below the MCL since that time so a treatment system
was never constructed. SWS has installed newer production wells to replace three of the aging original
wells and continues to pump considerable volumes of water from the Bartolo Well Field. SWS Bartolo
Well Field is located within the footprint of the Whittier Narrows OU. EPA is considering partial
deletion of the Suburban OU from the Site listing on the NPL because no further response action is
warranted.
Whittier Narrows OU
In March 1993, EPA issued an IROD for the Whittier Narrows OU for groundwater monitoring only.
An IROD Amendment was signed in November 1999, calling for groundwater extraction and
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treatment from extraction wells located just north of the Whittier Narrows Dam. EPA started
construction of the Whittier Narrows OU groundwater extraction and treatment facility in June 2001
and completed construction in March 2002. The interim groundwater pump-and-treat remedy has
been operating since that time. EPA completed a second FYR of the Whittier Narrows OU in
September 2011 and determined that the remedy is protective of human health and the environment.
El Monte OU
In June 1999, EPA issued an IROD for the El Monte OU that includes construction of groundwater
extraction wells, conveyance pipelines, and three groundwater treatment systems. An ESD was signed
in 2002, which incorporated treatment, as necessary, for emergent chemicals in the area. Construction
of the VOC cleanup systems began in mid-2011 and is ongoing.
Conclusion
Although the South El Monte OU interim remedy has not consistently achieved target extraction rates
during the review period, the remedy extraction systems are limiting the migration of contaminants of
concern (COCs) in groundwater and providing complete containment of the VOC-contaminated target
areas (called the central containment area and western containment area in the IROD). The
institutional controls (governmental controls) that are in place continue to effectively prevent
unacceptable exposure to contaminated Site groundwater. The South El Monte OU remedy is meeting
all Applicable or Relevant and Appropriate Requirements (ARARs) in the IROD, and there have been
no changes in ARARs affecting the protectiveness of the remedy. Although the toxicity values for
trichloroethene (TCE) became more stringent in 2011, the current MCL is within EPA's risk range and
is therefore protective of human health and the environment. Otherwise, there have been no other
significant changes in the toxicity factors for the COCs that were used in the previous risk assessments
or the standardized risk assessment methodology that could affect the protectiveness of the remedy.
EPA is actively evaluating vapor intrusion at facilities in the upgradient source areas as part of an
ongoing supplemental remedial investigation/feasibility study (RI/FS) to support a Final ROD for the
South El Monte OU. There is no other information that calls into question the protectiveness of the
remedy.
The Richwood OU remedy was shut down in November 1994. No active remedy was ever
implemented in the Suburban OU.
The overall protectiveness determination for the San Gabriel Valley Area 1 Superfund Site interim
remedy is deferred. A protectiveness determination at the South El Monte OU (OU 5) cannot be made
until further information is obtained. EPA is currently conducting a vapor intrusion investigation,
including soil vapor sampling and indoor air sampling at and near source facilities throughout the
South El Monte OU. It is expected that the investigation will take approximately 3 years to complete,
at which time a protectiveness determination will be made. The interim remedies for the Richwood
OU (OU 3) and Suburban OU (OU 4) are protective of human health and the environment.
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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iv Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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Five-Year Review Summary Form
Site Identification
Site Name: San Gabriel Valley (Area 1) - South El Monte, Richwood, Suburban,
Whittier Narrows, and El Monte Operable Units (OUs)
EPA ID:
Region: 9
CAD980677355
State: CA
NPL Status: Final
City/County: South El Monte, El Monte,
Temple City, and Rosemead/Los Angeles
County
Multiple OUs?
Yes
Has the site achieved construction completion?
No
Lead agency: EPA
If "Other Federal Agency" was selected above, enter Agency name:
Author name (Federal or State Project Manager): Rachelle Thompson
Author affiliation: EPA Region 9
Review period: October 2012 - May 2013
Date of site inspection: March 20, 2013
Type of review: Statutory
Review number: 1
Triggering action date: August 2008
Due date (five years after triggering action date): August 2013
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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Five-Year Review Summary Form (continued)
Issues/Recommendations
OU(s) without Issues/Recommendations Identified in the Five-Year Review:
Richwood OU 03, Suburban OU 04
Issues and Recommendations Identified in the Five-Year Review:
OU(s): South El
Monte OU 05
Issue Category: Changed Site Conditions
Issue: Vapor intrusion was not considered as an exposure pathway in the IROD.
Recommendation: Continue the ongoing vapor intrusion investigation and
implement removal and remedial actions at selected facilities, as appropriate.
Affect Current
Protectiveness
Affect Future
Protectiveness
Implementing
Party
Oversight Party
Milestone Date
Yes*
Yes*
EPA
EPA
09/30/2016
*The Comprehensive Environmental Response, Compensation, and Liability Information System
(CERCLIS) database only accepts "Yes" or "No" entries regarding whether an issue affects current or
future protectiveness. However, this protectiveness determination has been deferred because there is not
enough information to make the determination. For the purposes of the CERCLIS database, a "defer"
determination is equivalent to "yes" entry.
Protectiveness Statement(s)
Operable Unit:
Richwood OU 03
Protectiveness Determination:
Protective
Addendum Due Date
(if applicable):
Protectiveness Statement:
The interim remedy for the Richwood OU (OU 3) is protective of human health and the environment.
Operable Unit:
Suburban OU 04
Protectiveness Statement(s)
Protectiveness Determination:
Protective
Addendum Due Date
(if applicable):
Protectiveness Statement:
The interim remedy for the Suburban OU (OU 4) is protective of human health and the environment.
Operable Unit:
South El Monte OU05
Protectiveness Statement(s)
Protectiveness Determination:
Protectiveness Deferred
Addendum Due Date
(if applicable):
09/30/2016
Protectiveness Statement:
A protectiveness determination at the South El Monte OU (OU 5) cannot be made until further
information is obtained. EPA is currently conducting a vapor intrusion investigation, including soil vapor
sampling and indoor air sampling at and near source facilities throughout the South El Monte OU. It is
expected that the investigation will take approximately 3 years to complete, at which time a
protectiveness determination will be made.
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Contents
Executive Summary i
List of Tables ix
List of Figures x
List of Appendices x
List of Abbreviations xi
First Five-Year Review Report 1-1
1. Introduction 1-1
2. Site Chronology 2-1
3. Background 3-1
3.1. Physical Characteristics 3-1
3.2. Hydrology 3-2
3.3. Land and Resource Use 3-3
3.4. History of Contamination 3-3
3.4.1. South El Monte OU 3-4
3.4.2. Richwood OU 3-5
3.4.3. Suburban OU 3-5
3.5. Initial Response 3-6
3.6. Basis for Taking Action 3-6
4. Remedial Actions 4-1
4.1. Remedy Selection 4-1
4.1.1. South El Monte OU 4-1
4.1.2. Richwood OU 4-4
4.1.3. Suburban OU 4-4
4.1.4. Whittier Narrows OU 4-5
4.1.5. El Monte OU 4-5
4.2. Remedy Implementation 4-6
4.2.1. South El Monte OU 4-6
4.2.2. Richwood OU 4-9
4.2.3. Suburban OU 4-9
4.2.4. Whittier Narrows OU 4-10
4.2.5. El Monte OU 4-10
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4.3. Operation and Maintenance 4-11
4.3.1. South El Monte OU 4-11
4.3.2. RichwoodOU 4-13
4.3.3. Suburban OU 4-14
5. Progress Since the Last Five-Year Review 5-1
5.1. Previous Five-Year Review Protectiveness Statement 5-1
5.2. Work Completed at the Site During the Review Period 5-1
6. Five-Year Review Process 6-1
6.1. Administrative Components 6-1
6.2. Community Involvement 6-1
6.3. Document Review 6-1
6.3.1. Applicable or Relevant and Appropriate Requirements Review 6-1
6.3.2. Risk Assessment Review 6-2
6.4. Data Review 6-6
6.4.1. South El Monte OU 6-6
6.4.2. RichwoodOU 6-10
6.4.3. Suburban OU 6-10
6.5. Site Inspection 6-11
6.6. Interviews 6-11
6.7. Institutional Controls 6-13
7. Technical Assessment 7-1
7.1. Question A: Is the remedy functioning as intended by the decision
documents? 7-1
7.1.1. South El Monte OU Remedy 7-1
7.1.2. RichwoodOU 7-2
7.1.3. Suburban OU 7-2
7.2. Question B: Are the exposure assumptions, Toxicity Data, Cleanup
Levels, and Remedial Action Objectives (RAOs) Used at the Time of
Remedy Selection Still Valid? 7-2
7.2.1. Changes in Standards and Advisory Levels 7-3
7.2.2. Changes in Exposure Pathways 7-3
7.2.3. Changes in Toxicity and Other Contaminant Characteristics 7-3
7.2.4. Changes in Risk Assessment Methods 7-4
7.2.5. Expected Progress Toward Meeting RAOs 7-4
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7.3. Question C: Has Any Other Information Come to Light That Could Call
Into Question the Protectiveness of the Remedy? 7-4
7.4. Technical Assessment Summary 7-4
8. Issues 8-1
9. Recommendations and Follow-up Actions 9-1
9.1. South El Monte OU 9-1
9.2. Richwood OU 9-2
9.3. Suburban OU 9-2
10. Protectiveness Statements 10-1
10.1. South El Monte OU 10-1
10.2. Richwood OU 10-1
10.3. Suburban OU 10-1
11. Next Review 11-1
Appendix A: List of Documents Reviewed 3
Appendix C: Site Inspection Checklists 9
Appendix D: Interview Forms 3
List of Tables
Table 2-1: Chronology of Site Events by Operable Unit
Table 4-1: South El Monte OU Remedy Design Information
Table 4-2: Minimum Pumping Rates Required for Containment - Interim South El Monte OU
Remedy
Table 4-3: Approximate Costs of O&M for South El Monte OU Remedy Treatment Plants
Table 6-1: Summary of Changes in Chemical-Specific Standards and California Notification
Levels
Table 6-2: Applicable or Relevant and Appropriate Requirements Evaluation
Table 6-3: Exposure Pathways and Risks from Preliminary Risk Assessments
Table 6-4: Comparison Between Toxicity Values in Preliminary Risk Assessments and
Current Region 9 Values
Table 6-5: Summary of Drinking Water RSLs for Contaminants of Concern
Table 6-6. South El Monte OU Remedy Wells Annual Extraction Rates Compared to
Target Rates
Table 6-7. South El Monte OU Remedy Wells Extraction Rates Compared to Target Rates
Table 6-8. Mass of Contaminants Removed from South El Monte OU Remedy Wells
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Table 6-9: Compliance Monitoring Program for the South El Monte OU
Table 6-10: Water Quality Data from Compliance Monitoring, May 2011 to October 2012,
South El Monte OU
Table 6-11: Institutional Controls Summary Table
List of Figures
Figure 3-1: Location Map for the San Gabriel Valley Area 1 Superfund Site
Figure 3-2: Detailed Map of the South El Monte Operable Unit
Figure 3-3: Detailed Map of the Richwood Operable Unit
Figure 3-4: Detailed Map of the Suburban Operable Unit
Figure 4-1: Locations of Wells in the South El Monte OU Compliance Monitoring Program
Figure 6-1: Monterey Park Well 5 Comparison of Actual versus Target Pumping Rates
Figure 6-2: Monterey Park Wells 12/15 Comparison of Actual versus Target Pumping Rates
Figure 6-3: Golden State Water Company Wells SG1/SG2 Comparison of Actual versus
Target Pumping Rates
Figure 6-4: San Gabriel Valley Water Company Wells 8B/8C/8D Comparison of Actual
versus Target Pumping Rates
Figure 6-5: VOC Plume in the South El Monte OU Intermediate Aquifer
Figure 6-6: VOC Plume in the South El Monte OU Upper Intermediate Aquifer
Figure 6-7: Perchlorate Concentrations in the South El Monte OU Intermediate Aquifer
Figure 6-8: Capture Zones for the South El Monte OU Remedy
List of Appendices
Appendix A. List of Documents Reviewed
Appendix B: Public Notices
Appendix C: Site Inspection Checklists
Appendix D: Interview Forms
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List of Abbreviations
pg/L micrograms per liter
1,1,1 -TCA 1,1,1- trichloroethane
1,2,3-TCP 1,2,3-trichloropropane
1,2-DCA 1,2-dichloroethane
1,2-DCP 1,2-dichloropropane
AL Action Level
ARAR Applicable or Relevant and Appropriate Requirement
ASR applicable state requirement
ASTM ASTM International (formerly American Society for Testing and Materials)
ATSDR Agency for Toxic Substances and Disease Registry
bgs below ground surface
Cal-EPA California Environmental Protection Agency
CCR California Code of Regulations
CDHS California Department of Health Services
CDPH California Department of Public Health (formerly California Department of Health
Services)
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act of 1980
CERCLIS Comprehensive Environmental Response, Compensation, and Liability Information
System
CFR Code of Federal Regulations
cis-1,2-DCE cis-1,2-dichloroethene
COC contaminant of concern
DTSC California Department of Toxic Substances Control
EC emergent chemical
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ECAO Environmental Criteria and Assessment Office
EMOU El Monte Operable Unit
EPA United States Environmental Protection Agency
ESD Explanation of Significant Differences
FBR fluidized bed reactor
FS feasibility study
FYR Five-Year Review
GAC granular activated carbon
gpm gallons per minute
GSWC Golden State Water Company
HEAST Health Effects Assessment Summary Tables
HHRA human health risk assessment
HMWC Hemlock Mutual Water Company
HQ hazard quotient
IC institutional control
IRIS Integrated Risk Information System
IRM initial remedial measure
IROD Interim Record of Decision
IX ion exchange
LARWQCB Los Angeles Regional Water Quality Control Board
lb pound (s)
LGAC liquid-phase granular activated carbon
MCL maximum contaminant level
mg/kg milligrams per kilogram
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mg/kg/day
milligrams per kilogram per day
mg/L
milligrams per liter
mgd
million gallons per day
MP
City of Monterey Park
MRL
minimal risk level
msl
mean sea level
NCEA
National Center for Environmental Assessment
NCP
National Contingency Plan
NDMA
n-nitrosodimethylamine
NL
Notification Level
NPDES
National Pollutant Discharge Elimination System
NPL
National Priorities List
O&F
operational and functional
O&M
operations and maintenance
OEHHA
Office of Environmental Health Hazard Assessment
OMMP
Operations, Monitoring, and Maintenance Plan
OSWER
EPA Office of Solid Waste and Emergency Response
OU
operable unit
Ox
oxidation
PCE
tetrachloroethene
ppb
parts per billion
PPRTV
Provisional Peer Reviewed Toxicity Value
PRP
Potentially Responsible Party
RAO
remedial action objective
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RBCA
risk-based corrective action
REL
reference exposure level
RfD
reference dose
RfDi
reference dose inhalation
RfDo
reference dose oral
RHMWC
Rurban Homes Mutual Water Company
RI
remedial investigation
RME
Reasonable Maximum Exposure
RMWC
Richwood Mutual Water Company
ROD
Record of Decision
ROU
Richwood Operable Unit
RPM
Remedial Project Manager
RSL
Regional Screening Level
SCAQMD
South Coast Air Quality Management District
SEMOU
South El Monte Operable Unit
SFi
cancer slope factor inhalation
SFo
cancer slope factor oral
SGVWC
San Gabriel Valley Water Company
Site
San Gabriel Valley Area 1 Superfund Site
SNARL
Suggested No Adverse Response Level
SOU
Suburban Operable Unit
Suburban
Suburban Water Systems Bartolo Well Field
sws
Suburban Water Systems
TCE
trichloroethene
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trans-1,2-DCE trans-1,2-dichloroethene
U.S.C. United States Code
UV ultraviolet
VFD variable-frequency drive
VGAC vapor-phase granular activated carbon
VOC volatile organic compound
Watermaster Main San Gabriel Basin Watermaster
WIP well investigation program
WNOU Whittier Narrows Operable Unit
WQA San Gabriel Basin Water Quality Authority
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First Five-Year Review Report
for
San Gabriel Valley Area 1 Superfund Site
1. Introduction
The purpose of a Five-Year Review (FYR) is to evaluate the implementation and performance of a
remedy to determine whether the remedy will continue to be protective of human health and the
environment. The methods, findings, and conclusions of FYRs are documented in FYR reports, which
identify issues found during the review, if any, and document recommendations to address these
issues.
The United States Environmental Protection Agency (EPA) prepares FYRs pursuant to the
Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA)
Section 121, and the National Contingency Plan (NCP). CERCLA Section 121 states:
"If the President selects a remedial action that results in any hazardous substances,
pollutants, or contaminants remaining at the site, the President shall review such
remedial action no less often than each five years after the initiation of such remedial
action to assure that human health and the environment are being protected by the
remedial action being implemented. In addition, if upon such review it is the judgment
of the President that action is appropriate at such site in accordance with section [104]
or [106], the President shall take or require such action. The President shall report to the
Congress a list of facilities for which such review is required, the results of all such
reviews, and any actions taken as a result of such reviews. "
EPA interpreted this requirement further in the NCP (40 Code of Federal Regulations [CFR]
Section 300.430[f] [4] [ii]), which states:
"If a remedial action is selected that results in hazardous substances, pollutants, or
contaminants remaining at the site above levels that allow for unlimited use and
unrestricted exposure, the lead agency shall review such actions no less often than every
five years after the initiation of the selected remedial action. "
EPA conducted the FYR and prepared this report for the remedy implemented at the San Gabriel
Valley Area 1 Superfund Site (the Site) in Los Angeles County, California. The Site is being
addressed in five long-term remedial phases focusing on cleanup of areawide contamination: the
South El Monte Operable Unit (OU) (SEMOU, OU5), the Richwood OU (ROU, OU3), the Suburban
Water Systems Bartolo Well Field (Suburban) OU (SOU, OU4), the Whittier Narrows OU (WNOU,
OU2), and the El Monte OU (EMOU, OU1). EPA is the lead agency for developing and implementing
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the remedy for the Site. The California Department of Toxic Substances Control (DTSC), as the
support agency representing the State of California, provided input to EPA during the FYR process in
a letter regarding the scope of the review and through comments on the draft report.
This is the first FYR for the Richwood, Suburban, and South El Monte OUs (03, 04, and 05) of the
Area 1 Site. The Whittier Narrows OU (OU2) was evaluated in 2006 and 2011. The triggering action
for this statutory review was the signing of the South El Monte OU project Cooperative Agreement by
EPA and the San Gabriel Basin Water Quality Authority (WQA) on August 7, 2008, which funded the
South El Monte OU remedy. A FYR is required because hazardous substances, pollutants, or
contaminants remain onsite in groundwater above levels that allow for unlimited use and unrestricted
exposure.
Each OU is designated separately in EPA's Comprehensive Environmental Response, Compensation,
and Liability Information System (CERCLIS) database (an EPA database of information about
Superfund sites) and has individual cleanup goals and strategies specific to the OU. The cleanup goals
and plans for each OU are reported in documents known as Records of Decision (RODs). The RODs
for each OU were developed at different times, and as such, the cleanup efforts for each OU are at
different stages.
This FYR addresses the South El Monte, Richwood, and Suburban OUs in detail. The Whittier
Narrows OU and El Monte OU remedies are described in this FYR; however, they are not evaluated in
detail. A second FYR was completed for the Whittier Narrows OU in September 2011 and determined
that the remedy was protective. The El Monte OU remedy is under construction. It is anticipated that
subsequent Area 1 FYRs will fully evaluate all active Area 1 OUs.
The San Gabriel Valley Area 1 Superfund Site is one of four San Gabriel Valley groundwater sites
listed on the National Priorities List (NPL). The other three San Gabriel Valley sites are San Gabriel
Valley Area 2 (referred to as the Baldwin Park OU), San Gabriel Valley Area 3 (which addresses
contamination in the Alhambra area), and San Gabriel Valley Area 4 (which addresses the Puente
Valley OU).
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2. Site Chronology
Table 2-1 lists the dates of important events for the Site.
Table 2-1: Chronology of Site Events by Operable Unit
Event
Dnte
Initial discovery or contamination (volatile organic compounds [VOCs]
detected in a drinking water supply well).
1979
NPL listing (final).
05/08/1984
South El Monte OU
Interim Record of Decision (IROD) signed, defining the selected remedy for
the South El Monte OU.
09/2000
Golden State Water Company (GSWC) permitted by California Department of
Public Health (CDPH) to begin SG1/SG2 liquid-phase granular activated
carbon (LGAC) system operations.
10/2001
San Gabriel Valley Water Company (SGVWC) permitted by CDPH to begin
Plant 8 air stripper operations.
07/2002
GSWC permitted by CDPH to begin ion exchange (IX) system operations for
perchlorate treatment
11/2003
City of Monterey Park (MP) permitted by CDPH to begin operation of the
Well 12 IX (perchlorate treatment) and LGAC (secondary VOC treatment)
systems at the Delta facility.
05/2005
Explanation of Significant Differences (ESD) signed.
11/10/2005
MP permitted by CDPH to add Well 15 water to the Well 12 treatment
systems.
08/2006
MP permitted by CDPH for revised Well 5 LGAC operations (lead-lag
configuration) and perchlorate blending.
08/2006
SGVWC permitted by CDPH to begin LGAC (secondary VOC treatment)
system operations at Plant 8.
09/2006
EPA and WQA finalized the basic components of the Cooperative Agreement
covering use of water purveyor facilities to implement the interim remedy.
10/2006
EPA entered Cooperative Agreement with WQA. Minimum pumping rates set
for remedy wells.
08/07/2008
EPA funded the WQA grant initiating formal operation of the interim remedy
under the Cooperative Agreement.
09/2008
GSWC removes the perchlorate treatment from GSWC's San Gabriel
Treatment Plant.
03/2010
Removal of perchlorate treatment at MP Wells 9,12, and 15 treatment plant
05/20/2009
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
2-1
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tble 2-1: Chronology of Site Events by Operable Unit
Event
Date
Final Sampling and Analysis Plan - Remedial Action Compliance Monitoring
completed.
02/2011
Final Sampling and Analysis Plan - Supplemental Remedial Investigation/
Feasibility Study (RI/FS) completed.
03/2011
EPA completes installation of 12 new compliance monitoring wells.
06/2011
MP removes the Well 12/15 perchlorate treatment system from service.
08/2011
Compliance Well Installation and First Semi-Annual Remedial Action
Compliance Monitoring Report completed.
03/2012
EPA conducts final inspection of the South El Monte OU remedial action.
05/10/2012
CDPH permits use of GSWC's Well SG2 under an approved nitrate blending
plan.
07/2012
Remedial Action 2012 Compliance Monitoring Report completed.
04/2013
EPA declares the South El Monte OU interim remedy to be Operational and
Functional (O&F).
05/10/2013
Richwood OU
Focused FS completed for Area 1. The FS focused on the Richwood OU.
12/06/1983
ROD signed for the San Gabriel Area 1 Site. Initial remedial measures (IRMs)
for Richwood OU presented.
05/11/1984
ROD amendment for Richwood OU completed. Selected remedy included
granular activated carbon (GAC) treatment for Richwood Mutual Water
Company (RMWC).
09/1987
Richwood treatment plant completed and operational.
01/15/1992
Richwood OU transferred to the State of California. The California
Department of Toxic Substances Control (DTSC) assumed operations and
maintenance (O&M) of the treatment plant.
03/15/1994
DTSC entered into an agreement with SGVWC to supply water to RMWC
customers.
11/29/1994
Richwood OU treatment plant closed and wells abandoned.
11/1998
SGVWC purchased RMWC's assets and water rights and agreed to
permanently supply water to RMWC residences.
03/19/1999
SGVWC completed distribution system to RMWC residences.
12/06/1999
Suburban OU
Draft FS issued.
06/24/1988
ROD signed. Selected remedy included treatment by air stripping with GAC
off-gas treatment
9/26/1988
2-2
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
Table 2-1: Chronology of Site Events by Operable Unit
Event
Date
Screening risk assessment completed.
07/13/1992
ROD amendment signed. Due to decreasing levels of contaminants, treatment
system put on hold.
09/22/1993
Suburban Water Systems (SWS) destroys original Bartolo Wells 201W1,
201W2, 201W3, 201W5, and 201W6 and installs replacement wells 201W7,
201W8, 201W9, and 201W10.
2005-2011
Whittier Narrows OU
Monitoring-only IROD signed.
03/31/1993
FS Addendum and Proposed Plan completed.
10/1998
IROD Amendment signed.
11/10/1999
Construction completed for selected remedy.
03/31/2002
Remedial action complete, and remedial action report signed.
09/30/2003
First Five-Year Review (FYR) completed.
09/2006
Second FYR completed.
09/2011
O&M responsibility transferred from EPA to DTSC. SGVWC replaced City of
Whittier as operator of the treatment facility.
05/17/2013
El Monte OU
IROD signed.
06/1999
ESD signed to incorporate treatment of emerging contaminants of concern
(COCs).
8/22/2002
Construction of El Monte OU cleanup systems began and is currently
ongoing.
Mid-2011
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
2-3
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2-4 Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
3. Background
3,1, Physical Characteristics
The San Gabriel Valley lies approximately 25 miles east of the Pacific Ocean and encompasses an
area of approximately 170 square miles. The San Gabriel Valley Area 1 Superfund Site is an area of
contaminated groundwater that includes multiple, separate and commingled plumes that comprise a
large area of groundwater contamination in eastern Los Angeles County. The Site is located in the
San Gabriel Valley and consists of five OUs: South El Monte, Richwood, Suburban,
Whittier Narrows, and El Monte (see Figure 3-1). The contamination originates at current and former
industrial facilities in and near the cities of South El Monte, El Monte, Temple City, and Rosemead,
California.
The South El Monte OU covers approximately 8 square miles in the south-central portion of the
San Gabriel Basin and is bounded by the San Bernardino Freeway (Interstate 10) to the north, the
Pomona Freeway (Highway 60) to the south, the San Gabriel River Freeway (Interstate 605) to the
east, and San Gabriel Boulevard to the west (see Figure 3-1).
The Richwood OU is located in the City of El Monte, California, approximately 0. 5 mile west of
Interstate 605 and approximately 1 mile north of Interstate 10 (see Figure 3-1). The OU originally
consisted of an area of contaminated groundwater impacting three mutual water companies
(purveyors): the former RMWC, RHMWC, and HMWC.
The Suburban OU includes the SWS Bartolo Well Field, a set of public water supply wells located
along the east side of the San Gabriel River in the Whittier Narrows area (see Figure 3-1). The Bartolo
Well Field is located South of California Highway 60 and West of Interstate 605.
The Whittier Narrows OU encompasses approximately 4 square miles in the southern portion of the
San Gabriel Basin (see Figure 3-1) and represents the primary discharge point for groundwater and
surface water flow exiting the basin. Whittier Narrows is a 1.5-mile gap in the low-lying hills that
separate the San Gabriel Basin and the downgradient Central Basin. EPA designated Whittier Narrows
as an OU specifically to address groundwater contamination flowing out of the San Gabriel Basin,
through Whittier Narrows, into the Montebello Forebay portion of the Central Basin. The Montebello
Forebay is critical to the Central Basin groundwater aquifers because this is where the aquifers are
closest to the ground surface and receive most of their recharge. The Whittier Narrows OU is bounded
to the north by the Pomona Freeway (Highway 60) and to the south by the Montebello Forebay
portion of the Central Basin near the Whittier Narrows Dam.
The El Monte OU covers a surface area of approximately 10 square miles in the south-central portion of
the San Gabriel Basin. The El Monte OU is bounded on the north by several streets that traverse a
residential area between Lower Azusa and East Live Oak Avenue, on the south by Interstate 10, on the
west by Rosemead Boulevard, and on the east by Santa Anita Avenue (see Figure 3-1).
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
3-1
-------
3,2, Irology
The San Gabriel Basin, a piedmont plain that slopes gradually to the southwest at a gradient of
approximately 65 feet per mile, is located within the San Gabriel Valley. The San Gabriel Basin is a
structural groundwater reservoir that collects rainfall on the valley floor and runoff from the
surrounding highlands, recharging the groundwater. The San Gabriel Basin is bounded to the north by
the San Gabriel Mountains and to the southwest, south, and southeast by a crescent-shaped system of
low hills (see Figure 3-1). Surface water flows south out of the San Gabriel Basin via the Rio Hondo
River and the San Gabriel River, both of which flow through the South El Monte OU. The majority of
outflow from the San Gabriel Basin aquifer (about 80 percent) is through extraction by water supply
wells; the remaining 20 percent occurs as groundwater flow.
The San Gabriel Basin aquifer underlies most of the San Gabriel Valley and is characterized by
interfingering lenses of alluvial deposits (e.g., cobbles, gravel, sand, silt, and clay). It stores an
estimated 3 trillion gallons of water and is the primary source of water for most of the one million
residents in the Basin.
Groundwater in the South El Monte, Whittier Narrows, and Suburban OUs in the southern portion of
the San Gabriel Basin occurs at depths ranging from approximately 15 to 50 feet. In the South El
Monte OU, the data generated during the interim RI (Geosystem Consultants, Inc. [Geosystem], 1998)
and the interim FS (Geosystem, 1999) indicate the presence of a fairly extensive fine-grained sequence
of sediments that separates the Shallow Aquifer from the Intermediate Aquifer. This fine-grained
sequence, termed the Separating Sequence, generally is found in the interval between 100 and 200 feet
below ground surface (bgs), although its depth and thickness vary. The Separating Sequence tends to
become less apparent to the south, toward the Whittier Narrows OU. Lithologic data collected during
installation of new wells in 2011 generally support the presence of a fine-grained unit (Separating
Sequence) in the northern portion of the South El Monte OU and the presence of mostly medium- to
coarse-grained material to the south (ITSI Gilbane Company [ITSI], 2013).
Groundwater flow in the Shallow Aquifer is principally to the south and southwest, toward the
Whittier Narrows. Groundwater flow conditions in the Intermediate Aquifer are affected by a flow
divide that separates westward flow from southward flow through the Whittier Narrows. The Whittier
Narrows OU Five-Year Review (CH2M HILL, 201 la) reports that the flow divide is approximately
south of Rush Street and east of Rosemead Boulevard. This would place the divide or split roughly
beneath the middle of the primary industrial contaminant source areas in the central portion of the
South El Monte OU, and thus there is contaminated groundwater in the Intermediate Aquifer flowing
both west and south that has important ramifications on the evaluation of remedial alternatives for the
South El Monte OU. The location of the flow divide is transient, and it generally moves to the south in
the vicinity of the Highway 60 during low-water level conditions (CH2M HILL, 201 la). In this area of
the South El Monte OU, the bottom of the Intermediate Aquifer is approximately 600 feet bgs. The
Intermediate Aquifer is underlain by the Deep Aquifer, which extends to bedrock.
Groundwater in the El Monte OU flows generally in a west to southwest direction, although flow
fields in the shallow aquifer may be variable (Geosyntec, 2009) and includes a southerly flow
3-2
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
direction during prolonged drought conditions. The depth to groundwater is approximately 65 to
100 feet. Recent groundwater conditions in the nearby Richwood OU are not documented, but
expected to be similar to those in the El Monte OU.
3,3, Land ami Resource Use
Land use at the Site is largely urban, with a mix of residential, commercial, and industrial
development. Much of the development occurred in the 1950s and 1960s. Groundwater at the Site is
the primary source of drinking water to residents and businesses overlying the Site and in adjacent
areas. Groundwater is pumped from wells in each of the OUs at the Site and is replenished with
precipitation in the Valley, recharge of water flowing from the adjacent San Gabriel Mountains, and
recharge of water imported from Northern California and the Colorado River.
Most of the South El Monte OU is highly developed (Figure 3-2), except for the large area of land within
the Whittier Narrows flood control basin (ITSI, 2013). The South El Monte OU encompasses the entire
City of South El Monte and parts of the City of El Monte and the City of Rosemead. A majority of the
OU area is zoned for residential use, particularly the eastern and western portions of the OU, and these
areas are likely to remain residential. However, industrial activity, primarily small to medium-sized
businesses, does occur across a significant section of the central portion of the South El Monte OU.
Groundwater flow in the Whittier Narrows OU is principally from northeast to southwest from the San
Gabriel Basin into the Central Basin (CH2M HILL, 201 la). There are shallow, intermediate, and deep
drinking water wells located within Whittier Narrows and immediately downgradient in the Central
Basin. Most of the Whittier Narrows OU is undeveloped land dedicated to flood control and outdoor
recreational uses. Densely populated residential, commercial and light industrial areas surround the
Whittier Narrows OU. This includes extensive industrial areas in the immediately upgradient South El
Monte OU. Industrial activities within the Whittier Narrows OU are generally limited to the far eastern
portion of the Narrows. The nearby Suburban OU is largely undeveloped except for the production
wells and facilities of the Bartolo Well Field.
The area of land encompassing the El Monte OU is highly developed and lies within the cities of El
Monte, Rosemead, and Temple City (EPA, 1999). Most of the area is zoned for residential use and is
likely to remain residential. Industrial activity in the El Monte OU is primarily concentrated in the
central portion of the OU. The Richwood OU is located in the northeastern portion of the City of El
Monte has similar land and resource use to the El Monte OU.
nation
VOCs were first detected in groundwater in the San Gabriel Valley in 1979 during environmental
monitoring activities near a Potentially Responsible Party (PRP) facility in Azusa, California. By
1984, high levels of VOCs were found in 59 wells. On May 8, 1984, the Site was listed on the NPL.
Groundwater quality data generated by monitoring programs initiated by water purveyors in the basin
subsequently indicated that certain production wells completed in the deeper water-bearing zones also
had been impacted. In some wells, VOC concentrations were above the corresponding maximum
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
3-3
-------
contaminant levels (MCLs). Additional investigations triggered by this discovery revealed the
presence of VOCs, notably tetrachloroethene (PCE) and trichloroethene (TCE), throughout large areas
of the basin, apparently from multiple sources. The releases are widely believed to have begun shortly
after World War II when much of the San Gabriel Valley became industrialized. In response to the
contamination, water companies have shut down contaminated wells, installed new treatment
facilities, and taken other steps to ensure that they can continue to supply clean drinking water to the
public.
As of August 2004, 196 out of 275 water supply wells in the San Gabriel Valley had detectable levels
of one or more of the following contaminants: VOCs, perchlorate, n-nitrosodimethylamine (NDMA),
and 1,4-dioxane. The groundwater contamination is believed to result from the cumulative impact of
decades of improper chemical handling and disposal practices at hundreds of industrial operations in
the Valley. Although many of the laws regulating the handling and disposal of hazardous chemicals
went into effect after 1970, historical documents describe local officials' concerns about the potential
for groundwater contamination by industrial activity in the San Gabriel Valley as early as the 1950s.
Despite the widespread areas of contamination, the San Gabriel Basin aquifer continues to provide
approximately 90 percent of the domestic water supply for the Valley's residents.
Since site discovery, contaminant levels in groundwater have varied significantly across and within the
five OUs of the Area 1 Site. Although the highest historically measured groundwater contaminant
concentrations were in the 1,000s of micrograms per liter (pg/L), contaminant concentrations are now
commonly detected in the 10s to 100s of pg/L.
3.4.1. South El Monte OU
Subsequent to EPA's designation of the South El Monte OU to address regional groundwater
contamination, the Los Angeles Regional Water Quality Control Board's (LARWQCB's) well
investigation program (WIP) identified 143 facilities in the South El Monte OU at which VOCs were
stored, used, or otherwise handled (Geosystem, 1998). The WIP investigated 62 of the 143 facilities
through installation of 187 groundwater monitoring wells. On July 25, 1995, EPA executed
Administrative Consent Order, Docket No. 95-19 (the Consent Order) for the South El Monte OU
RI/FS and subsequently sent letters to 52 PRPs representing 43 facilities requesting they participate in
the RI/FS. A subset of those PRPs formed the South El Monte OU Participants who implemented the
interim RI/FS that was completed in 1999.
The RI determined that PCE, TCE, and other VOCs were contaminating portions of the shallow and
intermediate depth groundwater aquifer in a 15-square-mile area of the San Gabriel Valley around
South El Monte (EPA, 2005). Businesses in South El Monte and surrounding areas had used these
chemicals for degreasing, metal cleaning, and other purposes, and had probably released them to the
ground through a combination of onsite disposal, careless handling, leaking pipes, and other means.
The RI found that the uppermost, or shallow aquifer included most of the known sources of the
groundwater contamination. At the time, VOC concentrations in portions of the shallow aquifer were
hundreds of times federal and state drinking water standards, especially for PCE and TCE. In the
3-4
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
intermediate aquifer, VOC concentrations were generally lower, but still exceeded drinking water
standards.
In addition to the two primary VOC contaminants, PCE and TCE, recent groundwater monitoring
detected several, less extensive, emerging contaminants (ECs including perchlorate, 1,4-dioxane,
NDMA, and 1,2,3-trichloropropane (1,2,3-TCP)) (ITSI, 2013). Additionally, both the Shallow Aquifer
(generally less than 100 feet bgs) and the Intermediate Aquifer (generally between 100 and 600 feet
bgs) are considered by the State of California to be potential and existing drinking water sources,
respectively.
3.4.2. Richwood OU
In the early 1980s, PCE was detected above the California Department of Health Services (CDHS)
(now known as the California Department of Public Health [CDPH]) Action Level (AL) (now referred
to as Notification Level [NL]) in effect at that time of (4 pg/L), and TCE was detected above the
CDHS AL of 5 jig/L in production wells operated by RMWC, RHMWC, and HMWC (CH2M HILL,
1983). The MCLs for PCE and TCE were later set at 5 (ig/L.
As of 1984, RMWC provided water to approximately 204 households from two production wells
designated Well 1 (South or 1901521 on Figure 3-3) and Well 2 (North or 1901522 on Figure 3-3)
(EPA, 1984). In October 1980, PCE was first detected in RMWC Wells 1 and 2. From 1980 to 1983,
PCE concentrations ranged from 12 pg/L up to 92 pg/L in the RMWC wells.
As of 1984, HMWC provided water to approximately 199 households from two production wells
designated as the North Well (1901178 on Figure 3-3) and South Well (1902806 on Figure 3-3)
(EPA, 1984). PCE was first detected in the HMWC wells in May 1982 (EPA, 1984). Subsequent
sampling results indicated PCE concentrations of 50 pg/L in the South Well in December 1982 and
38 ]ig/L in the North Well in April 1983. In 1984, the South Well was taken out of service when a
PCE concentration of 184 ]ig/L was detected.
As of 1984, RHMWC provided water to approximately 290 households from two production wells
designated Well 1 (North or 1900120 on Figure 3-3) and Well 2 (South or 1900121 on Figure 3-3)
(EPA, 1984). In October 1980, PCE was first detected in RHMWC Wells 1 and 2 (EPA, 1984).
From October 1980 to early 1983, PCE concentrations ranged up to 16 pg/L in Well 1 and 54 pg/L in
Well 2. In May 1983, PCE concentrations declined to 1.7 ]ig/L in Well 1 and 3.7 ]ig/L in Well 2.
Figure 3-3 shows the location of the production wells and approximate historical extent of PCE
contamination in the Richwood OU.
3.4.3. Suburban OU
In 1986, EPA identified 36 wells, including the four SWS Bartolo Well Field wells (201W-2, 201W-
5, 201W-4, and 201W-6), that were threatened by VOC contamination above CDHS ALs (EPA,
1988). In the fall of 1986, SWS contacted EPA concerning contamination in the Bartolo Well Field.
The four wells in the Bartolo Well Field provided over 55 percent of the water supply for 70,000
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
3-5
-------
residents in the City of Whittier and had a combined pumping capacity of approximately 9,300 gallons
per minute (gpm) (EPA, 1988). In March 1987, based on the discussions with SWS regarding the
Bartolo Well Field contamination, EPA initiated the SWS Bartolo Well Field OU (later referred to
simply as the Suburban OU) Feasibility Study. PCE and TCE concentrations in the Bartolo Well Field
increased from 1986 through 1988, when TCE was detected above the MCL of 5 (ig/L in Well 201W4
(EPA, 1988).
Figure 3-4 shows the location of the original and current production wells in the Bartolo Well Field.
3.5, Initial Respon
No pre-ROD removal actions were taken at the Site. However, prior to the South El Monte OU IROD,
water purveyors did begin implementing wellhead treatment units at production wells that ultimately
were designated as South El Monte OU remedy extraction wells.
3.6, 1 ' 1 1 ' >#?
The concentrations of multiple contaminants in the groundwater exceed federal and state MCLs or
State of California NLs (previously known as ALs).
3-6
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
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SAN GABRIEL VALLEY
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Figure 3-3: Detailed Map of the Richwood Operable Unit
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Location of Wells and Pipelines
Figure 3-4: Detailed Map of the Suburban Operable Unit
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4. Remedial Actions
4. >lection
4.1.1. South El Monte OU
EPA issued an IROD for the South El Monte OU on September 29, 2000. The selected remedy
includes containment of groundwater contaminated with VOCs in the intermediate aquifer zone at two
general locations within the western portion of the South El Monte OU. EPA's remedial action
objectives (RAOs) for the South El Monte OU are to:
• Prevent exposure of the public to contaminated groundwater.
• Contain further migration of contaminated groundwater from more highly contaminated portions
of the aquifer to less contaminated areas or depths.
• Reduce the impact of continued contaminant migration on downgradient water supply wells.
• Protect future uses of less contaminated and uncontaminated groundwater.
The IROD indicates that the selected remedy for the South El Monte OU will be implemented using a
performance-based approach. The performance-based approach specifies criteria ("performance
criteria") that must be met while allowing flexibility in implementation. The performance criteria are
designed to attain the RAOs for the South El Monte OU. The selected remedy addresses the
intermediate zone groundwater contamination present in the western portion of the South El Monte
OU. For purposes of describing the remedy, the contamination has been separated into two areas:
(1) the central area of intermediate zone contamination, and (2) the western area of intermediate zone
contamination.
The central area of intermediate zone contamination refers to the contamination located in the vicinity
of MP production Wells 12 and 15 and the SGVWC Plant 8 Wells 8A through 8F, and is also referred
to the Central Containment Area (well locations are shown in Figure 3-2).
The western area of intermediate zone groundwater contamination refers to the intermediate zone of
contamination downgradient (west) of MP Well No. 12 in the vicinity of the GSWC Wells San
Gabriel (SG) 1 and 2, Garvey 1 and 2, and Earle 1 and additional MP Wells 1,3,5,6, 10 and Fern and
is also referred to as the Western Containment Area (see Figure 3-2).
The existing groundwater remedy in the Whittier Narrows OU is anticipated to capture shallow and
intermediate zone VOC contamination in the South El Monte OU that is migrating to the south
(EPA, 2005).
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IROD Performance Criteria
The remedial action shall provide sufficient hydraulic control to prevent migration of intermediate
zone groundwater contaminated above chemical-specific Applicable or Relevant and Appropriate
Requirements (ARARs) into or beyond the Central Containment Area and into or beyond the Western
Containment Area.
Compliance with performance criteria is verified through monitoring of compliance wells for two
parameters: hydraulic gradient and chemical-specific ARARs. The remedial action must create an
inward hydraulic gradient at each of the containment areas. These hydraulic gradients must be
sufficient to demonstrate that contaminated groundwater is captured by the extraction wells under all
flow conditions (e.g., during both wet and dry periods in the hydrologic cycle). Implementation of
the remedial action cannot result in any adverse effects (i.e., increases in migration of contamination)
to production wells that are not part of the remedial action. In addition, the remedial action must
provide the required capture of contamination above chemical-specific ARARs without relying on the
effects of wells that are not part of the remedial action.
Compliance with the performance criteria is confirmed by sampling and water level monitoring at
compliance wells. In the Central Containment Area, compliance with the performance criteria is
initially determined through monitoring of hydraulic gradients. After hydraulic containment has been
achieved and contaminant concentrations downgradient from extraction wells have dropped below
ARARs, the monitoring program will be expanded to include monitoring for compliance with
chemical-specific ARARs at downgradient compliance wells.
In the Western Containment Area, compliance with the performance criteria is determined through
monitoring of hydraulic gradients and chemical-specific ARARs. Contaminant concentrations in
downgradient compliance wells must meet chemical-specific criteria at all times.
In both containment areas, EPA expects that groundwater containment actions will be implemented
sufficiently upgradient of the chemical-specific compliance wells to provide a buffer zone to allow
additional actions to be taken, if necessary, to ensure compliance, but close enough to ensure that
groundwater contamination is being contained. Imminent exceedance of chemical-specific ARARs at
downgradient compliance wells indicates that groundwater contamination is continuing to migrate and
improved hydraulic containment is required.
The IROD assumed that the groundwater would be treated to remove VOCs and delivered to local
water purveyors. In addition to the compliance monitoring described above, the remedy includes
monitoring in selected shallow and intermediate zone wells throughout the South El Monte OU.
Explanation of Significant Differences
In response to the detection of contaminants that were not specifically addressed in the IROD, EPA
prepared an ESD in November 2005. Perchlorate, a chemical used in solid rocket fuel, was detected in
the groundwater in the Central and Western Containment Areas above the state of California (State)
drinking water advisory level (which later became a formal State MCL). Because of these detections,
CDPH required that the extracted water be treated for perchlorate before its use by water purveyors as
drinking water supply.
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The ESD incorporates the potential need for perchlorate treatment into the South El Monte OU interim
remedy, describes potential treatment technologies to be used, and summarizes the estimated costs
associated with treating perchlorate.
An additional contaminant, 1,4-dioxane, a stabilizer in chlorinated solvents, has also been detected at
elevated concentrations in South El Monte OU groundwater. However, at the time the ESD was
prepared, the concentrations of 1,4-dioxane detected in the intermediate zone were not high enough to
require treatment of the extracted water before use as drinking water.
Remedial Design
In October 2006, WQA and EPA successfully completed negotiations and a work plan for a Superfund
Support Agency Cooperative Agreement that covers implementation of the South El Monte OU
interim remedy described in the IROD. WQA has separate agreements with three local water
purveyors (MP, SGVWC, and GSWC) whose facilities are being used to meet EPA's remedial goals.
The remedy needs to meet the IROD-specified performance criteria to demonstrate that the required
hydraulic control is being provided. In 2006, EPA conducted groundwater modeling simulations to
identify minimum pumping rates and operational scenarios for implementation of the remedy. The
groundwater modeling results suggested that the target areas (those portions of the Central
Containment Area and Western Containment Area where VOCs exceed MCLs) in the intermediate
zone can generally be captured under a number of different extraction scenarios that incorporate
seasonally varied pumping from MP Wells 5, 12, and 15; SGVWC Wells 8C and 8D; and GSWC
Wells SGI and SG2. The minimum pumping rate scenario shown in Table 4-2, with an average annual
pumping rate of just under 6,000 gpm, was selected to meet the hydraulic containment goals of the
interim remedy, while also addressing water purveyor demands and treatment system limitations.
In August 2008, after various legal settlements with PRPs were completed, the grant for the
Cooperative Agreement was funded, marking the formal start of remedy operations (EPA, 2008a). The
minimum quarterly average target pumping rates identified in Table 4-2 are incorporated into the
Cooperative Agreement between EPA and WQA. The water purveyor facilities described as remedy
components had all been designed and constructed well in advance of the formal initiation of work
under the Cooperative Agreement. CDPH reviewed each treatment system, required that the water
purveyors demonstrate system performance during startup and testing, and based on each system's
performance, approved and issued separate drinking water permits for each facility.
The major components of the South El Monte OU interim remedy are four separate groundwater
pump-and-treat systems, ranging in capacity from 1,500 gpm to 5,000 gpm. Total treatment capacity is
12,600 gpm of contaminated groundwater (18 million gallons per day [mgd]). The South El Monte
OU remedy design information is summarized in Table 4-1.
The final component of the remedy is a network of compliance monitoring wells (covering both the
Central and Western Containment Areas) specifically intended to produce data for use in evaluating
remedy performance and determining compliance with the performance criteria identified in the
IROD. The location and design assumptions for the compliance monitoring wells were based on
interpreted groundwater flow conditions and the lateral and vertical distribution of contamination in
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the two Containment Areas. Figure 4-1 shows the locations of the compliance monitoring wells and
remedy extraction wells.
4.1.2. Richwood OU
In May 1984, EPA adopted a ROD that selected IRMs for a portion of the Area 1 Superfund Site that
later became the Richwood OU. The intent of the IRMs was to develop either alternative water
supplies or treatment systems that would allow three local water purveyors to supply clean drinking
water to their customers. The ROD stated that the IRM should be developed to meet the cancer risk
level of 1 x 10"6 and enable the three purveyors to supply drinking water with levels of PCE
contamination below the EPA Suggested No Adverse Response Level (SNARL) of 4 (ig/L
(EPA, 1984). The IRMs were focused on three local water purveyors (RMWC, HMWC, and
RHMWC) operating in a portion of the City of El Monte.
In September 1987, EPA issued an amendment to the 1984 ROD (EPA, 1987) indicating that
installation of a carbon adsorption or GAC treatment system was more effective than the installation
of an air stripper treatment system. At the time of the ROD Amendment, PCE detected in RHMWC
production wells had declined from a maximum concentration of 54 (ig/L to 1.14 (ig/L. below the
CDHS AL. Based on the reduced concentrations, EPA stated in the ROD Amendment that
implementation of the IRM selected for the RHMWC was not necessary. HMWC had already declined
EPA assistance and installed a GAC treatment system that became operational in 1986.
In June 1985, PCE was detected in RMWC production wells at concentrations as high as 110 (ig/L,
which prompted CDHS to make a determination of imminent or substantial endangerment. CDHS
subsequently funded installation of a temporary emergency connection between the RMWC
distribution system and the SGVWC system. At the time of the ROD Amendment, EPA recommended
the design and installation of a GAC treatment facility for the RWMC production wells due to the
temporary nature of the emergency connection between RWMC and SGVWC, and because PCE
concentrations remained well above the CDHS AL (EPA, 1987).
4.1.3. Suburban OU
In September 1988, EPA adopted the Suburban OU ROD that was intended to partially control the
movement and spread of contaminants in the eastern portion of the Whittier Narrows area and to
address the potential public health threat posed by contaminants in the SWS's Bartolo Well Field
(EPA, 1988). The selected remedy consisted of a groundwater treatment system at the Bartolo Well
Field designed to treat PCE to a concentration of 1 (.ig/L. At the time of the 1988 ROD, there was no
state or federal regulatory standard set for PCE. Subsequent to the 1988 ROD, the CDHS and EPA
established the MCL for PCE at 5 j^ig/L (EPA, 1993).
Design of the potential treatment system for the Bartolo Well Field was completed in 1991. However,
groundwater contamination levels in the Suburban OU had dropped below federal drinking water
standards. In September 1993, EPA issued a ROD Amendment that changed the remedy to monitoring
only and included:
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• Postponing construction of the proposed treatment system because PCE concentrations were
below the MCL
• Increasing the treatment level from 1 (.ig/L to the MCL of 5 (.ig/L for PCE
• Adding a contingency plan to treat groundwater should contaminant levels again exceed federal
drinking water standards
• Adding evaluation of sampling results from the Bartolo wells for at least 5 years
4.1.4. Whittier Narrows OU
In 1993, EPA issued an IROD that concluded no immediate action was needed to address groundwater
contamination, but that monitoring should continue, including installation of additional monitoring
wells. In response to increasing contaminant levels, EPA issued an IROD Amendment in 1999 that
required an active pump-and-treat system, including extraction of groundwater from extraction wells
located just north of the Whittier Narrows Dam (EPA, 1999). A remedy was designed to extract and
treat 11,000 gpm of groundwater. The remedy consisted of seven groundwater extraction wells,
conveyance pipelines, and 20 pairs of GAC vessels for removal of VOCs. EPA started construction of
the Whittier Narrows OU groundwater extraction and treatment facility in June 2001 and completed
construction in March 2002.
4.1.5. El Monte OU
EPA issued an IROD in June 1999 to address containment of groundwater contaminated with VOCs.
An ESD was signed in 2002 which incorporated treatment, as necessary, for the emergent chemicals
(ECs) perchlorate, 1,4-dioxane, hexavalent chromium, and NDMA. For implementation purposes, the
groundwater remedy has been divided into the East Side and West Side subprojects (OU8 and OU9).
Each subproject is being implemented by a separate PRP or PRP group and EPA is overseeing the
work of both. The two subprojects include construction of 11 extraction and injection wells, four
pipelines, and three groundwater treatment plants to supplement eight existing extraction wells and an
existing treatment plant. When completed, there will be four individual groundwater pump-and-treat
systems to remove VOC contamination from the Eastern Shallow Zone, Southern Deep Zone, Western
Shallow Zone, and Northwestern Deep Zone.
^mentation
4.2.1. South El Monte OU
Construction of the water purveyor treatment facilities started before EPA prepared the South El
Monte OU IROD and continued in various stages through mid-2006. By the time remedy
implementation began under the Cooperative Agreement in August 2008, all of the primary
construction activities had been completed by the water purveyors. The specific water purveyor
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facilities included in the Cooperative Agreement for use in the South El Monte OU remedy are
described in the following sections.
EPA has negotiated nine Consent Decrees with industrial facility PRPs to partially fund
implementation of the IROD interim remedy.
City of Monterey Park
Three of the MP wells have been incorporated into the South El Monte OU remedy: Well 5, Well 12,
and Well 15. Water pumped from Well 5 is treated separately at its own facility. Water pumped from
Wells 12 and 15 is treated at a separate treatment facility.
The VOC treatment facility for MP Wells 12 and 15 consists of an air stripper system with VGAC off-
gas treatment, acid injection to control precipitation, an LGAC secondary barrier, and caustic addition, if
necessary, to raise pH levels. The combined treatment system is limited to a maximum combined flow of
4,500 gpm because of the air stripper system capacity. The air stripper was constructed in 1999.
The MP Well 12 perchlorate treatment system was constructed in 2003 at MP's Delta Plant. It was
built to remove perchlorate using IX technology and disposable IX resins. The perchlorate system was
permitted for active use by CDPH in May 2005. The perchlorate treatment system had a design
capacity of 4,500 gpm and was intended to treat the effluent water from the Well 12 air stripper. The
perchlorate treatment system was taken offline in August 2011 because the perchlorate concentrations
are low enough that CDPH no longer requires treatment. The plant piping has been reconfigured to
bypass the IX vessels.
Because MP Wells 12 and 15 were being considered for use in the Superfund remedy and VOC
concentrations were increasing, CDPH required that a secondary "dual-barrier" VOC treatment
process be added to the treatment facility. MP installed an LGAC treatment system to serve as the dual
barrier. The LGAC system was constructed in 2004 at MP's Delta plant. The LGAC system has a
design capacity of 4,500 gpm (750 gpm through each of six carbon vessels) and treats water that has
already passed through the air stripper (and, when active, the IX vessels). CDPH permitted operation
of the LGAC system in May 2005.
MP Well 15 is located on the Whittier Narrows golf course, which is part of the Whittier Narrows
Recreation Area. Well 15 was installed in 2004 specifically to serve as a key component of the South
El Monte OU interim remedy and is located directly downgradient of elevated intermediate zone VOC
contamination. Well 15 is connected by pipeline to the air stripper located adjacent to Well 12.
Well 15 was permitted for use by CDPH in 2006.
The MP Well 5 LGAC treatment system for VOC removal was constructed and began operating in
1999. The treatment system consists of five carbon vessels. In the original parallel configuration, the
system had a design capacity of 2,500 gpm for the removal of VOCs. The system was modified in
2003 to a lead-lag series configuration using four of the carbon vessels. This reduced the capacity to
approximately 1,600 gpm. The carbon was removed from the fifth vessel and it is inactive. Perchlorate
has also been detected in MP Well 5. However, the levels have been low enough that CDPH does not
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require treatment. A perchlorate blending plan was approved by CDPH as part of a 2006 permit
amendment for the Well 5 treatment system.
Golden State Water Company
There are two production wells located at GSWC's San Gabriel Plant: San Gabriel Well No. 1 (SGI)
and San Gabriel Well No. 2 (SG2).
In 2001, GSWC installed a VOC treatment facility. The treatment facility included three lead-lag pairs
of LGAC vessels intended to remove the VOC contamination in Wells SGI and SG2. The treatment
system originally had a capacity of 2,250 gpm (750 gpm per vessel pair), which was adequate to
accommodate the combined flow from Wells SGI and SG2. However, elevated concentrations of
nitrate in Well SG2 have affected GSWC's ability to produce potable water from this well, so it was
not operated on a consistent basis for many years. The original permit for treatment facility operations
was issued October 24, 2001.
In July 2002, perchlorate was detected in Well SGI and shortly thereafter in Well SG2. To address
perchlorate, the carbon was removed from one of the LGAC vessel pairs and replaced with an IX resin
specifically intended for perchlorate removal. The plant piping was modified so that water from the
wells first flowed through the remaining two pairs of LGAC vessels for VOC removal, then flowed
through the single vessel pair with IX resin for perchlorate removal. The permitted system capacity
under the new configuration was reduced to 1,100 gpm, the peak flow allowed through the IX vessel
pair. However, the actual capacity was closer to 1,000 gpm. CDPH issued the revised permit
incorporating the IX vessels for perchlorate treatment on November 14, 2003.
In early 2010, GSWC began working with CDPH on a potential nitrate blending plan that would allow
Well SG2 to return to service. CDPH approved the blending plan and issued an updated permit
amendment in July 2012.
Changes made at the San Gabriel treatment facility as part of returning Well SG2 to service included
refilling two of the LGAC vessels with carbon such that all three pairs of vessels were once again
arranged in a lead-lag configuration for the removal of VOCs, and installing two in-line nitrate
analyzers. In accordance with the CDPH-approved nitrate blending plan, Well SG2 has a maximum
flow rate of 300 gpm and cannot run unless Well SGI is also operating. Under the blending plan, the
maximum flow rate from Well SGI will be approximately 1,200 gpm, and the maximum flow rate
from the treatment plant 1,500 gpm.
San Gabriel Valley Water Company
SGVWC's Plant No. 8 is located along the Rio Hondo Channel in the City of South El Monte. There
are five active water production wells at the Plant 8 facility : Wells 8B, 8C, 8D, 8E, and 8F. However,
only Wells 8B, 8C, and 8D are part of the South El Monte OU interim remedy. Wells 8E and 8F are
perforated in a deeper portion of the aquifer, below the vertical extent of contamination.
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In December 2001, SGVWC completed construction of the VOC treatment facility at Plant No. 8. The
treatment facility consisted of a 5,000-gpm air stripper and an off-gas VGAC treatment system
approved by the South Coast Air Quality Management District (SCAQMD). After complying with the
CDPH procedures for permitting the air stripper, SGVWC placed the treatment facility online in
July 2002. The current SCAQMD permit for the air stripper includes an influent VOC concentration
limit of 100 parts per billion (ppb). In March 2003, CDPH required SGVWC to add a second
"dual-barrier" VOC treatment system to the existing treatment facility at Plant 8 because of concerns
about the sharply rising VOC concentrations.
In December 2004, SGVWC completed construction of an LGAC treatment system to serve as the
dual barrier for water treated by the air stripper. CDPH approved SGVWC's amended permit in
September 2006 allowing operation of the LGAC treatment system.
The LGAC treatment system consists of six pairs of vessels. Each pair of vessels operates in a lead-lag
configuration where the water runs through the first (lead) vessel and then through the second (lag)
vessel.
Additional Contaminant Source Area Investigation
In the 2000 IROD, EPA acknowledged that the interim remedial action was only intended to control
the migration of contamination, and that future remedial actions may include additional actions at or in
the vicinity of industrial facilities identified as groundwater contamination sources in the South El
Monte OU. The IROD also stated that the interim action would neither be inconsistent with, nor
preclude, implementation of a final remedy. EPA is currently conducting a supplemental RI/FS that
will facilitate preparation of a final ROD for the Site. The initial phases of work completed to date
have included sampling existing shallow monitoring wells, collecting grab groundwater samples,
conducting focused soil gas investigations at selected facilities, and installing shallow and
intermediate zone monitoring wells. EPA is also investigating the potential for vapor intrusion in the
South El Monte OU as part of its ongoing supplemental RI. During soil gas sampling at source
facilities in 2011 and 2012, EPA discovered concentrations of VOCs in soil gas at five facilities that
warranted further investigation by EPA's emergency response program. EPA conducted indoor air
sampling at those commercial facilities and nearby residences. Two of the locations, the former
One Dollar Cleaners and Hytone Cleaners, had indoor air levels of PCE that were well above
screening levels, so EPA is overseeing a voluntary cleanup at the former One Dollar Cleaners facility,
and conducting a removal action at five residences near the Hytone Cleaners facility to mitigate vapor
intrusion. Additional indoor air sampling is planned in 2013 at approximately 20 other commercial
facilities. EPA plans to address the findings from the supplemental RI/FS, including source area
groundwater and soil vapor contamination, in the final ROD.
Compliance Monitoring
EPA installed a network of compliance groundwater monitoring wells in 2011 to monitor the
performance of the remedy (see Figure 4-1).
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4.2.2. Richwood OU
On January 15, 1992, EPA completed construction of the Richwood Treatment Plant, located at
4155 Richwood Avenue in El Monte, California (EPA, 1995). EPA transferred responsibility for the
O&M of the treatment plant to DTSC on March 15, 1994. DTSC staff felt that the O&M costs of the
treatment facility were unreasonably high. Rather than continuing to operate the treatment plant,
DTSC entered into an agreement with SGVWC in which SGVWC would provide water to the
approximately 200 residences served by RMWC. SGVWC purchased RMWC's assets and water
rights in March of 1999 (McCormick, 1999). As part of the purchase agreement, SGVWC installed a
new water distribution system for the former RMWC customers, and DTSC contributed funds to
facilitate the transfer of assets. The distribution system upgrades and transition to SGVWC's system
were complete and operational in December 1999. The former RMWC customers are primarily
supplied water from SGVWC Plants 1 and 2; however, because SGVWC's water distribution system
is interconnected, the water could potentially come from almost any of the company's wells. This
operation has not changed since the RMWC customers were originally integrated.
RHMWC continues to supply water to 300 homes for approximately 1,200 persons. RHMWC samples
their two production wells twice per year for a full range of contaminants and has not had detections of
contaminants exceeding drinking water standards.
HMWC also continues to supply water to its customers. HMWC's wells are sampled annually and no
contaminants have been detected in recent years as reported by the Watermaster in the interview for
this FYR (see Appendix D) and in the Draft Five-Year Water Quality and Supply Plan (Watermaster,
2012).
4.2.3. Suburban OU
As described above, contaminant concentrations in SWS's Bartolo Well Field have remained low
since the early 1990s. In accordance with the September 1993 ROD Amendment, no active remedy
was ever implemented for the Suburban OU. SWS destroyed Wells 201W1 and 201W3 in 2005,
201W2 and 201W6 in 2008, and 201W5 in 2011. These wells were replaced with four new wells
(Wells 201W7, 201W8, 201W9, and 201W10) that together with Well 201W4, make up the active
wells in the Bartolo Well Field also known as Plant 201 (see Figure 3-4). The SWS Bartolo Well Field
continues to extract water at high rates and represents a key component of the SWS water supply
system.
4.2.4. Whittier Narrows OU
EPA started construction of the Whittier Narrows interim remedy in June 2001 and completed
construction in March 2002. The interim remedy is now in the operation and maintenance phase.
Starting in 2005, the interim remedy was operated by the City of Whittier on behalf of EPA. EPA
funded operation of the remedy through a Cooperative Agreement between the City of Whittier and
EPA. The City of Whittier incorporated the intermediate zone treated groundwater, which was
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permitted for potable use, into its drinking water supply. The treated shallow zone groundwater was
discharged to Legg Lakes under a three-party water production agreement between EPA, the Main San
Gabriel Basin Watermaster, and Los Angeles County. On May 17, 2013, DTSC assumed
responsibility for implementation of the Whittier Narrows OU interim remedy and SGVWC replaced
the City of Whittier as operator of the treatment facility. Pending completion of planned modifications
to the treatment facility, and subsequent approval by CDPH, the treated intermediate zone water will
be distributed to SGVWC's system for use as drinking water. Until that time, all of the treated water is
being discharged to Legg Lakes.
EPA conducted a second FYR of the Whittier Narrows OU in 2011 (EPA, 2011) and determined that
the remedy is protective of human health and the environment.
This section completes the description of the Whittier Narrows OU remedy for this FYR report. The
Whittier Narrows OU is not evaluated as part of this FYR because the remedy was recently evaluated
in a separate FYR completed in July 2011.
4.2.5. El Monte OU
The Northwestern Deep Zone remedy component of the interim El Monte OU remedy is the only
portion of the remedy that has been completely implemented. The Northwestern Deep Zone system
makes use of GSWC's Encinita Well Field. The extracted groundwater is treated through a GAC
treatment system to remove VOCs, then distributed by GSWC as drinking water supply.
The Western Shallow Zone component of the El Monte OU remedy has been constructed and initial
operations are underway. The final construction inspection process has not been completed. The
groundwater extracted for the Western Shallow Zone component water is treated for VOCs through a
GAC system and for nitrates through a FBR system, then discharged into Eaton Wash surface water.
The Southern Deep Zone and Eastern Shallow Zone components of the El Monte OU remedy are still
under construction. Construction of these last two VOC treatment systems is expected to be completed
in 2014. The El Monte OU remedy is expected to be protective of human health and the environment
once construction is complete.
This section completes the description of the El Monte OU remedy for this FYR report. The El Monte
OU is not evaluated further as part of this FYR because the construction of the remedy is not yet
complete.
laintenance
4.3.1. South El Monte OU
O&M requirements for the South El Monte OU interim remedy are primarily associated with meeting
EPA's minimum pumping rate targets (see Table 4-2) and producing treated water that meets all
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drinking-water criteria and CDPH-permit requirements. Specific O&M requirements vary between the
four different treatment systems operated by the three water purveyors.
The treatment facilities have been operating continuously in compliance with CDPH requirements for
a number of years. However, there have been some operational constraints that have resulted in the
flow rates periodically being less than the minimum pumping rates identified by EPA (see Table 4-2),
particularly for MP Wells 12 and 15. Despite flow rates periodically being below the minimum
pumping rates, capture of contamination appears to be adequate as discussed further in Section 5.
Under the Cooperative Agreement, WQA submits quarterly and annual reports to EPA that document
any significant O&M issues. The following paragraphs briefly summarize key operational issues from
the last few years for each treatment plant. Additional details of O&M activities can be found in the
O&M plans for each treatment facility and performance reports prepared by WQA, as listed in
Appendix A.
City of Monterey Park
The minimum target pumping rates for Well 5 are very low compared to the system capacity, so there
have not been any challenges in meeting target rates. In addition, the Well 5 system has not had any
significant operational issues over the last several years. Routine O&M activities at the Well 5
treatment plant include changeout of spent carbon from the VOC treatment system, and operation of
the chlorination system, nitrate analyzer, and perchlorate blending plan. Carbon changeouts at the
Well 5 LGAC system are relatively infrequent because of the low contaminant concentrations. Routine
O&M activities at the Wells 12 and 15 treatment plant include changeout of spent carbon in the
VGAC and LGAC treatment vessels, replacing the filters located upstream of the LGAC vessels, and
operating the acid injection, caustic injection, and chlorination systems. Water quality samples are
collected at varying frequencies at both MP treatment facilities and analyzed for VOCs, 1,4-dioxane,
perchlorate, and other chemical constituents (CH2M HILL, 2013).
MP has had a difficult time achieving the quarterly minimum target pumping rates for Well 15 and, to
a lesser extent, Well 12. The combined target rate for these two wells is relatively close to the
treatment system capacity (4,500 gpm) in some quarters, so there is limited operational flexibility to
make up for any downtime. In addition, through August 2011, the Well 12/Well 15 treatment system
also included the IX system for perchlorate treatment. Inclusion of an additional treatment process
increased O&M requirements and the potential for downtime. The primary O&M activities that have
resulted in increased downtime and reduced average pumping rates over the last few years include:
Well 15 pump replacement and motor repairs required because of excessive shaft vibration, air stripper
system maintenance and repairs, and dual-barrier LGAC system carbon changeouts and associated
post-changeout bacteriological detections. The reduced pumping rates primarily occur at Well 15
because it is equipped with a variable-frequency drive (VFD) that allows its pumping rate to be
adjusted. Well 12 only operates at approximately 2,000 gpm and is either on or off. In 2012, Wells 12
and 15 operated at approximately 92 percent of the combined target rate for the two wells.
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San Gabriel Valley Water Company
Routine O&M at the SGVWC Plant 8 treatment system includes changeout of spent carbon in the
liquid-phase GAC vessels and the vapor-phase off-gas treatment system, monitoring air stripper
operations, and chlorination. Water quality samples are collected from throughout the treatment plant
and from plant effluent to ensure compliance with CDPH standards (CH2M HILL, 2013).
Production from SGVWC's Plant 8 remedy Wells 8B, 8C, and 8D has consistently exceeded the
combined minimum target pumping rates for the three wells over the last several years. There has been
minimal downtime at the Plant 8 system. Carbon changeouts at the dual-barrier LGAC only occur
every 2 to 3 years, and the production wells and air stripper have not required any significant
maintenance.
Golden State Water Company
Routine O&M at the treatment plant associated with the GSWC SGI and SG2 wells includes
changeout of spent carbon in the GAC vessels, chlorination, and a blending operation to address
nitrate levels in Well SG2. Water quality samples are collected from the LGAC vessels and from the
plant effluent to ensure compliance with CDPH standards. Occasional backwashing of the GAC
treatment vessels is required (CH2M HILL, 2013).
In the two quarters since GSWC Well SG2 was brought back online under the CDPH-approved nitrate
blending plan, production has significantly exceeded the minimum target pumping rates of the two
wells combined. Prior to that, the system generally met the target pumping rates using the SGI well
alone. However, based on the capacity of the SGI well, there was limited flexibility to make up for
periods of downtime associated with either routine or nonroutine O&M requirements. For example, if
the system was down for a carbon changeout during one of the quarters with the higher target pumping
rates, GSWC would have difficulty meeting the quarterly combined target rates. In the second quarter
of 2011, the SG1 well pump/column was replaced and the motor rebuilt due to wear (WQA, 2011).
This major repair resulted in significantly reduced production for the quarter.
Groundwater Monitoring Wells
There is an extensive groundwater monitoring well network in place that provides critical data for
evaluating groundwater and contaminant conditions in the South El Monte OU interim remedy area
and demonstrating compliance with IROD performance criteria. The monitoring well network is fully
operational and most wells are monitored at least twice a year. In spring 2013, minor maintenance
activities were conducted at seven of the older monitoring wells. This included replacing missing bolts
from the monitoring well covers and replacing a damaged concrete apron surrounding two of the
wellheads.
Future Operation and Maintenance Activities
To maintain compliance with the South El Monte OU interim remedy performance criteria, the remedy
wells operated by the three water companies described above will need to continue to extract enough
4-12
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
groundwater, on average, to meet EPA's minimum target pumping rates identified for each well or set
of wells. Future O&M activities will be similar to the current ongoing O&M activities and include:
• Routine operation of the groundwater production wells
• Routine operation of the air strippers and GAC treatment systems
• Periodic changeout of spent LGAC and VGAC
• Routine operation of booster pumps and chlorination facilities
• Extensive system monitoring in accordance with CDPH requirements
• Periodic collection of groundwater level and groundwater quality data
If contaminant concentrations increase significantly or if new contaminants are detected, more
substantial changes to the existing treatment systems may be required to meet the target pumping rates
and maintain remedy performance.
O&M Costs
In the South El Monte OUIROD, EPA initially estimated that annual O&M costs would be $840,000.
In the ESD, EPA revised the estimated annual O&M costs as ranging from $2.2 million to $4.8 million
to account for additional treatment needed for perchlorate in the intermediate groundwater and the
dual-barrier treatment for VOCs in groundwater. Table 4-3 summarizes the past O&M costs for the
South El Monte OU remedy. Annual O&M costs have ranged from $1.54 million to $2.07 million,
which is consistent with the low end of the range of estimated annual O&M costs in the ESD. It should
be noted that perchlorate treatment has not been required for the last several years. Total expenditures
in the first quarter of 2013 were approximately $500,000 dollars, and future expenditures are expected
to remain near that level (WQA, 2013).
4.3.2. Richwood OU
While the RMWC treatment plant was operational, O&M activities included carbon changeout,
maintenance and repair of piping and treatment vessels, chlorination, and upkeep of the RMWC
distribution system that was originally built in the 1930s. According to a 1995 DTSC memorandum,
leaks in the RMWC distribution system were detected and repaired on a weekly basis, and a
significant O&M project was the installation of a recycle loop to smooth out variations in chlorine
concentrations in the effluent pipeline in the mid-1990s (DTSC, 1995). The RMWC treatment plant
was shut down in 1995, marking the end of O&M activities for the remedy.
4.3.3. Suburban OU
An active remedy was never constructed for the Suburban OU, so there were no O&M activities. SWS
continues to operate and maintain the Bartolo Well field as an important component of their water
supply system.
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
4-13
-------
4.3.3. Suburban OU
An active remedy was never constructed for the Suburban OU, so there were no O&M activities. SWS
continues to operate and maintain the Bartolo Well field as an important component of their water
supply system.
Trocitmont
I'kmt
Trmitmont
CiipiK'itv
I'lxti'iKtion
VVolls
Tieiitnient
MP Well 5
1,600 gpm
Well No. 5
Extraction well, LGAC treatment for VOCs, CDPH-
approved blending plan for perchlorate, and
disinfection.
MP Wells 12
and 15
4,500 gpm
Well No. 12
Well No. 15
Extraction wells, air stripping, off-gas vapor-phase
granular activated carbon [VGAC] treatment, acid
injection to control precipitation, LGAC secondary
barrier, caustic injection for pH adjustment, and
disinfection. Ion exchange (IX) treatment for
perchlorate was previously included but has been
removed
SGVWC Wells
8B, 8C, and 8D
5,000 gpm
Well No. 8B
Well No. 8C
Well No. 8D
Extraction wells, air stripping, off-gas VGAC
treatment, acid injection to control precipitation
and LGAC calcification, LGAC secondary barrier,
and disinfection.
GSWC San
Gabriel
Treatment Plant
1,500 gpm
Well No. SGI
Well No. SG2
Extraction wells, LGAC for VOC treatment, CDPH-
approved blending plan for nitrate, and
disinfection. IX treatment for perchlorate was
previously included but has been removed.
4-14
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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Minimi . , ¦ 1 < ¦ 1 n 1 ' »dy
South El Monte Operable Unit
San Gabriel Valley Area 1 Superfund Site. Los Angeles County, California
Minimum Pumping Rates3
Quarter lb
Quarter 2h
Quarter 3b
Quarter 4h
Annual Total*
Remedy Wells
Avg GPM
A ere-Feet'
Avg GPM
A ere-Feet'
Avg GPM
A ere-Feet'
Avg GPM
A ere-Feet'
Avg GPM
A ere-Feet'
MPS
69
27
89
36
270
110
89
36
130
209
MP 12
2,000
796
2,000
804
2,000
813
2,000
813
2,000
3,226
MP 15
1,612
641
1,923
773
2,205
897
1,917
779
1,916
3,091
Purveyor Usage'1
5,370
5,670
5,670
5,670
GSVVC SGI
424
169
564
227
625
254
438
178
513
828
GSVVC SG2
297
118
395
159
437
178
307
125
359
579
Combined SG Total1
721
287
959
386
1,062
432
745
303
872
1,407
Purveyor Usage'1
1,512
1,594
1,624
1,549
SGVVVC 8B
0
0
0
0
0
0
0
0
0
0
SGVVVC 8C
582
231
751
302
1,333
542
682
277
839
1,353
SGVVVC 8D
138
55
179
72
317
129
162
66
199
322
Combined Plant 8 Totalr
720
286
930
374
1,650
671
844
343
1,038
1,674
Purveyor Usage'1
1,600
3,800
3,300
1,500
SOURCE: ITS I, 2013, Remedial Action 2012 Compliance Monitoring Report, San Gabriel Valley Superfund Site, South El Monte Operable Unit, April
The average GPM rates shown assume continuous pumping 24/7 for the entire quarter. If there is any time when a well is not pumping or is pumping at less
than the target rate, pumping during the remainder of the quarter will have to be increased to meet the quarterly target rate.
'"Quarter 1 = Jan -Mar. (90 days), Quarter 2 = Apr.-Jun. (91 days), Quarter 3 = July-Sept. (92 days), Quarter 4 = Oct.-Dec. (92 days)
cThe acre-feet target per quarter is calculated by multiplying the average GPM x 1440 minutes/day x # of days per quarter divided by 325,829 gallons/acre-foot
"'Estimates provided by well owners.
eGSWC can use any combination of pumping from the SGI and SG2 wells to meet these minimum production targets.
£
SGVVVC should try and match the distribution of remedy well pumping shown; however, the Plant 8 pumping will be acceptable as long as the combined total
is met from the three remedy wells.
8 The water purveyors should try to meet the quarterly target rates listed in the table; however, the pumping totals will be acceptable as long as the annual totals
arc met each year and none of the quarterly pumping totals is more than 25% below the target rate for that quarter.
9/20/2010 (Modified prior version to include annual rates and additional notes)
-------
Table 4-3: Approximate Costs of O&M for South El Monte Oil Remedy Treatment Plants
Treatment Plant
O&M Costs ($)
20081
2009
2010
2011
2012
Total
MP Well 5
-
366,979
308,277
248,805
215,376
1,139,437
MP Wells 12 and 15
32,509
1,022,597
1,225,699
926,203
580,737
3,787,746
City of Monterey Park
Total
32,509
1,389,576
1,533,976
1,175,009
796,113
4,927,182
GSWC Wells SGI and SG2
7,068
90,258
145,413
101,702
254,690
599,129
SGVWC Plant 8
-
171,169
391,217
411,785
490,136
1,464,307
Total
39,576
1,651,002
2,070,606
1,688,495
1,540,939
6,990,619
Note:
1 Only includes O&M costs for September 2008 through December 2008.
4-16
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
t
-SAXON 3
SAXON 4
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San Gabriel 1 and 2
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Monterey Park
Well 5
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fountain Valley,,
a Sft
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Ezcarpmti
ra-- w . ,* Miiu nm
Fountain^Vallev.. /
Huntington Beach.. ~ -- .Irvtne ,
Newport Beach ,/Costa Mesa '
>EMW09
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-MP08
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I ism u^s,
. Rancho Santa t.
ulonV^o
Late Fore^ ^ \
Copyiight:'©3S?<,Pel-orme
SEMW19AB
Monterey Park
Well 15
t,
Monterey Park
Well 12
U
SEMW21 ABC
L
SEMW20AB S
Uj
§
co
O
EPAW414
M
SEMW27
SEMW22AB
J
^-SEW
SEMW06—
m£Em3\
SEMW24AB
- - - .HW.Y60, -
0t .t tIC-. a |
1&:
• "hf
ik
Modified from ITS 1,2013, Remedial Action 2012 Compliance Monitoring Report, San Gabriel Valley Superfund Site, South B Monte Operable Unit, April;
;
dv r.
SEMW28
'
O
A
New Compliance Monitoring Well 2013
Intermediate Aquifer Monitoring Well
Remedy Extraction Well
Non-Remedy Extraction Well
South El Monte Operable Unit Boundary
NOTES:
GSWC = Golden State Water Company
SGVWC = San Gabriel Valley Wfoter Company
MP = Monterey Park
-New compliance monitoring wells
SEMW10 - SEMW17 were installed in 2011.
-Refer to Table 2-3 for well specifications.
Background image from Microsoft® Bing™, 2011.
1,500
A
Feet
1.500
iTsicgjHB
Remedial Action Compliance Monitoring
South El Monte Operable Unit
Los Angeles County, California
Image courtesy of USG"5 Ci^^^MifcTosoft Corporation Image ®6ufte>,y*o| LAR-I^C
New Monitoring Well Locations 2013
Figure 4-1: Locations of Wells in the South El Monte OU Compliance Monitoring Program
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This page is intentionally left blank.
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5. Progress Since the Last Five-Year Review
•wh r / Protective*!ess Statement
The San Gabriel Valley Area 1 Superfund Site has not undergone a previous FYR, and thus there is no
previous FYR protectiveness statement. However, one OU within the Area 1 Superfund Site, Whittier
Narrows, has undergone two OU-specific FYRs. The protectiveness statement from the second FYR
for the Whittier Narrows OU (EPA, 2011) was as follows:
The remedy at Whittier Narrows OU is protective of human health and the environment.
Work completed at the Site during the review period is discussed in Section 4.
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
5-1
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This page is intentionally left blank.
5-2 Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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6. Five-Year Review Process
iilnlsi iponents
EPA Region 9 initiated the FYR in October 2012 and scheduled its completion for August 2013. The
FYR team for Area 1 was led by Rachelle Thompson of EPA, Remedial Project Manager (RPM) for
the South El Monte OU Site. The team also included Cynthia Wetmore of the Regional Technical
Support Program, and contractor support provided by CH2M HILL. The review process included
document and data review, standards review, interviews, site inspections, and community
involvement.
6.2. 'vo/vement
EPA published notices announcing the start of the FYR in the San Gabriel Valley Tribune on
December 7, 2012, and in La Opinion (in Spanish) on December 8, 2012. No responses to the public
notices were received. The public notices are provided in Appendix B.
The FYR report will be made available to the public once it has been finalized. Copies of this
document will be placed in the following designated public repositories:
West Covina Library EPA Superfund Records Center
1601 West Covina Parkway 95 Hawthorne Street, Room 403
West Covina, CA 91790 San Francisco, CA 94105-3901
Upon completion of the FYR, EPA will produce and distribute a fact sheet announcing the availability
of the final FYR report in the Site document repositories. Both the fact sheet and the final FYR report
also will be made available on EPA's website.
6.3. Docur. w
This FYR included a review of relevant, site-related documents including the South El Monte OU
IROD, South El Monte OU ESD, Remedial Action 2012 Compliance Monitoring Report for the South
El Monte OU (ITSI, 2013), recent monthly progress reports and annual performance monitoring
reports for the South El Monte OU (WQA, 2010 to 2013), the San Gabriel Area 1 ROD and ROD
Amendment for the Richwood OU, and the ROD and ROD Amendment for the Suburban OU. A
complete list of the documents reviewed is provided in Appendix A.
6.3.1. Applicable or Relevant and Appropriate Requirements Review
Section 121 (d) (2) (A) of CERCLA specifies that Superfund Remedial Actions must meet any federal
standards, requirements, criteria, or limitations that are determined to be ARARs. ARARs are those
standards, criteria, or limitations promulgated under federal or state law that specifically address a
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
6-1
-------
hazardous substance, pollutant, contaminant, remedial action, location, or other circumstance at a
CERCLA site.
Chemical-specific standards and nonpromulgated advisories or guidance identified for the selected
remedy in the South El Monte OU IROD (2000) or in the subsequent South El Monte OU ESD (2005)
for the groundwater at this Site, and considered for this FYR for continued groundwater treatment and
monitoring, are listed in Table 6-1. Because the Richwood OU remedy stopped operating in 1994 and
the Suburban OU remedy was never implemented, ARARs for these two OUs were not reviewed. The
IROD included 39 VOCs for chemical-specific ARARs, but only 8 of those 39 were included as COCs
in the risk assessment. Those eight chemicals are included in Table 6-1 along with perchlorate and
1,4-dioxane, which were discussed in the ESD (although treatment for 1,4-dioxane was not added to
the interim remedy in the ESD).
As the IROD adopted an interim remedy, chemical-specific cleanup requirements for the aquifer were
not established. Federal and state drinking water standards for COCs were considered relevant and
appropriate for treatment plant effluent (i.e., ARARs). Perchlorate did not have an MCL at the time of
the 2005 ESD. For COCs that lack MCLs, safe levels were specified by NLs (previously known as
Als) developed by the CDPH (formerly the CDHS). The NLs are not ARARs but are "to be
considered" (TBC) because water purveyors must notify customers if these levels are exceeded. The
current NL for 1,4-dioxane of 1 pg/L is more stringent than at the time of the IROD and the ESD.
Effective October 18, 2007, the State of California promulgated an MCL for perchlorate of 6 ]ig/L
(Cal-EPA, 2012).
State primary drinking water standards are the same as federal primary drinking standards with the
following exceptions:
• Perchlorate does not have a federal MCL.
• Benzene, 1,2-dichloroethane (1,2-DCA), trans-1,2-dichloroethene (trans-1,2-DCE),
cis-l,2-dichloroethene (cis-1,2-DCE), and vinyl chloride have more stringent state MCLs than
federal MCLs.
Federal and state laws and regulations that have been promulgated or changed over the past 5 years, or
that are otherwise applicable to the South El Monte OU interim remedy, are described in Table 6-2.
There have been no revisions to laws and regulations that affect the protectiveness of the remedy.
6.3.2. Risk Assessment Review
The preliminary risk assessments discussed below identified the exposure pathways and associated
risks presented in Table 6-3. The preliminary risk assessments were reviewed to identify any changes
in exposure or toxicity that would impact protectiveness of the remedy currently in place.
6-2
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
South El Monte OU Human Health Risk Assessment
The South El Monte OU Preliminary Human Health Risk Assessment (HHRA) (CH2M HILL, 1997)
is based on data collected from production and monitoring wells between July 1993 and July 1995,
except for 15 monitoring wells where data collected between February 1990 and April 1993 is used.
Sampling data were available from 25 production wells, one EPA monitoring well, and 131 site
assessment monitoring wells for the HHRA. A total of eight COCs were identified in South El Monte
OU groundwater that contributed significantly to the risk results and include: benzene, 1,2-DCA,
1,2-DCE, cis-l,2-DCE, 1,2-dichloropropane (1,2- DCP), TCE, PCE, and vinyl chloride.
Exposure to contaminants in groundwater could occur through the use of groundwater for domestic
purposes, such as ingestion of tap water, inhalation of contaminants from water used for bathing,
cooking and laundering, and dermal contact with the water. The two exposure scenarios and pathways
evaluated in the South El Monte OU HHRA include: (1) potential for a current resident to be exposed
to contamination in groundwater through domestic use and (2) potential for a future resident to be
exposed to contamination in groundwater through domestic use. A summary of risk and hazard
estimates is provided in Table 6-3.
A screening level evaluation of volatile emissions to indoor air was also performed as part of the
preliminary HHRA (CH2M HILL, 1997). See exposure pathways section below for revisions to vapor
intrusion exposure pathway evaluation methodology.
Suburban OU Human Health Risk Assessment
The groundwater quality data used in the Suburban OU HHRA were obtained from analyses of
samples collected in the Bartolo Well Field and upgradient in that portion of the San Gabriel Basin
groundwater system expected to influence the Bartolo Well Field in the near future (EPA, 1992). For
the preliminary HHRA, only the most recent sampling data available at the time were evaluated (dated
September 23-24, 1991).
COCs were detected in groundwater samples obtained from the SWS Bartolo Well Field OU. The
primary COCs included chloroform, TCE, PCE, 1,1-DCE and 1,1-DCA, cis-l,2-DCE, and
1,1,1- trichloroethane (1,1,1-TCA). Risks were evaluated for residents that currently obtain water from
the Bartolo Well Field. The exposure pathways associated with potential residential use of
groundwater in this HHRA were primarily domestic uses including: (1) exposure resulting from
ingestion of ground water and (2) exposure resulting from inhalation of VOCs while engaged in
domestic activities (showering, dish washing, doing laundry etc.). A summary of risk and hazard
estimates is provided in Table 6-3.
Richwood OU
A preliminary risk assessment was not performed for the Richwood OU. The 1987 ROD Amendment
identified PCE as the primary COC at the Richwood OU. A PCE concentration limit of 1 ppb was
recommended because it was deemed to be both protective of public health and technologically
feasible for treatment (EPA, 1987).
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
6-3
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Changes and Revisions to Preliminary Risk Assessments
Each preliminary risk assessment identified the exposure pathways and associated risks shown in
Table 6-3. The risk assessments were reviewed to identify any changes in exposure or toxicity that
would impact protectiveness of the remedy currently in place.
Exposure Pathways
EPA's understanding of contaminant migration from soil gas and/or groundwater into buildings has
evolved over the past few years leading to the conclusion that vapor intrusion may have a greater
potential for posing risk to human health than assumed when the preliminary risk assessments and
RODs were prepared. In April 2013, EPA released an external review draft version of its vapor
intrusion guidance titled OSWER Final Guidance for Assessing and Mitigating the Vapor Intrusion
Pathway from Subsurface Sources to Indoor Air (EPA, 2013a).
EPA is currently conducting an evaluation of vapor intrusion at selected facilities identified during a
screening-level assessment for the South El Monte OU that includes soil gas sampling and indoor air
sampling. The findings from this indoor air evaluation will support a final ROD for the Site.
Indoor air evaluations were not performed for the Suburban OU preliminary risk assessment or for the
Richwood OU. However, the remedy at the Suburban OU was never implemented and the remedy at
the Richwood OU ceased operation in 1994. There are no known sources is the Richwood or
Suburban OUs that would suggest a vapor intrusion pathway in these areas.
No other changes in exposure pathways were identified that would impact protectiveness of the
remedy.
Toxicity Values:
EPA's Integrated Risk Information System (IRIS) (EPA, 2013b) has a program to update toxicity
values that are used to conduct human health risk assessments when newer scientific information
becomes available. Since the completion of the preliminary risk assessments, there have been a
number of changes to the toxicity values for various COCs at the Site. Current toxicity values take into
account values provided in the California Office of Environmental Health Hazard Assessment's
(OEHHA) Toxicity Criteria Database (2013) and EPA's Regional Screening Level (RSL) table
(2013). The most conservative value between what is provided by OEHHA and the EPA RSL table is
selected as the current toxicity value. Table 6-4 provides a comparison of the current toxicity values
with the values used in the preliminary risk assessments. For each chemical that had an update, the
toxicity value change would cause an increase or a decrease in the estimated risk/hazard in comparison
with the results of the preliminary risk assessments.
Based on the changes to toxicity values provided in Table 6-4, the current estimated risk and hazard
may be over- or underestimated. However, the preliminary risk assessments were used to estimate the
human health and environmental risks that the Site could pose if no action were taken. EPA's current
action and remedy are primarily based on the presence of contamination in groundwater at levels that
exceed current drinking water standards.
6-4
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
The EC 1,4-dioxane has been detected consistently in the South El Monte OU since 2000, at levels
exceeding CDPH NLs. 1,4-Dioxane was not considered in the preliminary risk assessments. Both
cancer and noncancer toxicity values are currently available for 1,4-dioxane and provided by OEHHA
and EPA (2013a). Critical human health effects include the liver, kidney, and hematologic effects.
Perchlorate has also been detected regularly since 2000 across a broad area of South El Monte OU
groundwater. Though treatment was required for several years, perchlorate concentrations are now
consistently below the California MCL of 6 pg/L. For perchlorate, a noncancer oral reference dose
(RfD) is provided by EPA and the primary target organ is the thyroid gland.
Two other ECs detected sporadically in the South El Monte OU are NDMA and hexavalent chromium.
NDMA and hexavalent chromium concentrations are typically very low. For NDMA, cancer and
noncancer toxicity values are provided by OEHHA and EPA; the primary target organ is the liver.
Both cancer and noncancer toxicity values are available for hexavalent chromium and provided by
OEHHA and EPA. The primary target organ for hexavalent chromium is the respiratory tract.
A detailed discussion of the changes to the toxicity criteria for TCE and PCE is provided below.
TCE/PCE in Groundwater
Groundwater results are compared to EPA RSLs as a first step in determining whether response
actions may be needed to address potential human health exposures. The RSLs are chemical-specific
concentrations that correspond to an excess cancer risk level of 1x10 6 (or a Hazard Quotient (HQ) of 1
for noncarcinogens) developed for standard exposure scenarios (e.g., residential and
commercial/industrial). RSLs are not de facto cleanup standards for a Superfund site, but they do
provide a good indication of whether actions may be needed. In September 2011, EPA completed a
review of the TCE toxicity literature and posted on IRIS both cancer and noncancer toxicity values
which resulted in lower RSLs for TCE. The screening level for chronic exposure for an excess cancer
risk level of 1x10 6 is 0.44 pg/L. EPA uses an excess cancer risk range of 10 4 tolO 6 for assessing
potential exposures, which correlates to a TCE concentration between 0.44 and 44 pg/L. The current
TCE MCL of 5 pg/L is within the revised protective carcinogenic risk range. EPA's 2011
Toxicological Review for TCE also developed safe levels that include at least a 10 fold margin of
safety for health effects other than cancer. Any concentration below the noncancer RSL indicates that
no adverse health effect from exposure is expected. Concentrations significantly above the RSL may
indicate an increased potential of noncancer effects. The noncancer screening level for TCE is
2.6 ]ig/L. EPA considers the TCE MCL of 5 ]ig/L protective for both cancer and noncancer effects.
EPA also recently reassessed PCE toxicity literature for both cancer and noncancer effects and
released the toxicological review in February 2012, which is posted on IRIS. The reassessment
determined that the screening level risk for cancer in excess of 1x106 was less stringent than
previously assumed and has raised the cancer RSL for PCE to 9.7 jxg/L. The noncancer RSL was also
revised based on adverse neurological effects and resulted in a noncancer risk RSL of 35 pg/L. The
PCE MCL of 5 pg/L remains protective for both carcinogenic and noncancer effects.
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
6-5
-------
ew
6.4.1. South El Monte OU
Data from quarterly and annual performance reports prepared by WQA (2010 to 2013), the
Compliance Well Installation and First Semi-Annual Remedial Action Compliance Monitoring Report
(ITSI, 2012), the Final 2012 Remedial Action Compliance Monitoring Report (ITSI, 2013), the Draft
Remedial Action Report (CH2M HILL, 2013), queries of EPA's SGV database, and various other
reports were reviewed as part of the FYR to evaluate whether the South El Monte OU interim remedy
is achieving remedial action objectives. The results of the data review are discussed below.
Groundwater Extraction System Performance
Table 6-6 summarizes the annual extraction rates by calendar year achieved at the South El Monte OU
remedy wells from September 2008 through March 2013, compared to the target rates included in the
Cooperative Agreement. Except for the first performance reporting period (September 2008 to June
2010), the performance reporting periods for the South El Monte OU remedy are July through June of
each year. To be consistent with the WQA performance reports, Table 6-7 presents the pumping rates
in terms of reporting periods.
During the first reporting period, September 2008 through June 2010, MP Well 5 met the target
quarterly pumping rates during all quarters. MP Well 12 met quarterly pumping rates except for
September 2008 (89 percent of the target rate) and the first quarter of 2010 (85 percent of the target
rate). MP Well 15 did not meet target pumping rates. Although GSWC Well SG2 was out of operation
during the entire operating period, Well SGI was able to meet the combined target pumping rates
during all quarters except the second and third quarters of 2009. SGVWC Wells 8B and 8D met the
target pumping rates for each quarter; however SGVWC Well 8C did not meet target pumping rates.
Overall, the remedy wells substantially met the target pumping rates during the first reporting period.
During the second reporting period, July 2010 through June 2011, MP Well 5 exceeded target
pumping rates during each quarter. MP Well 12 exceeded target pumping rates in the first and second
quarter of the reporting period and nearly met them in the fourth quarter. MP Well 12 did not meet the
target pumping requirements in the third quarter. MP Well 15 pumped below target pumping
requirements for each quarter of the reporting period. GSWC Well SG2 remained out of service;
however, Well SGI was able to meet the combined pumping rates in the second and third quarter of
the reporting period. Well SGI pumped below the pumping requirements in the second quarter of
2011. The SGVWC Plant 8 wells met the target combined pumping requirements for all quarters of
the reporting period. The remedy wells substantially met the target pumping rates except during the
second reporting period.
During the third reporting period, July 2011 through June 2012, MP Wells 5 and 12 achieved target
pumping rates during every quarter. MP Well 15 pumped below target pumping rates in three of the
four quarters; however, it achieved 87 percent of the annual target rate. GSWC Well SG2 remained
out of service. Well SGI was able to meet the annual combined target pumping rate during the third
6-6
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
reporting period despite pumping slightly below the target quarterly rate in the first quarter of 2012.
SGVWC Plant 8 wells exceeded the combined target pumping rates each quarter. Overall, the remedy
wells substantially met the target pumping rates during the third reporting period.
From July 2012 through March 2013, MP Well 5 exceeded target pumping rates in all three quarters.
MP Wells 12 and 15 did not meet target pumping rates in the third and fourth quarter of 2012. MP
Wells 12 and 15 exceeded target pumping rates in the first quarter of 2013. GSWC Wells SGI and
SG2 met the target pumping rates during all three quarters, as did the SGVWC Plant 8 remedy wells.
Overall, the remedy wells substantially met the target pumping rates from July 2012 through March
2013.
Charts illustrating the quarterly 2011-2013 pumping rates for each set of remedy wells compared to
the EPA minimum quarterly target pumping rates shown in Table 4-2 are included in Figures 6-1
through 6-5.
Contaminant Mass Removal
Contaminant mass removal is estimated annually based on flow rates from groundwater extraction
wells and water quality results for these same extraction wells. Table 6-8 summarizes the contaminant
mass removal estimates for the South El Monte OU.
Significant contaminant mass continues to be removed by the interim remedy. The majority of
contaminant mass removed occurs at the MP remedy wells primarily due to their larger total pumping
rate. Mass removal at the GSWC wells was significantly lower than removal at SGVWC wells.
Performance Monitoring
In addition to the groundwater extraction rate measurements and contaminant mass removal estimates,
the primary data collected to evaluate performance of the interim remedy include groundwater level
and groundwater quality data. A comprehensive groundwater compliance monitoring program is in
place to monitor water levels and water quality to provide data needed to evaluate remedy
performance. The monitoring program, described in the Final Sampling and Analysis Plan, Remedial
Action Compliance Monitoring (ITSI, 201 la) includes seven multi-port wells (SEMW01 through
SEMW05, SEMW07 and SEMW08), each with three discrete-depth sample intervals representing
various intermediate zone intervals; multi-port well SEMW06 with two intermediate zone sample
intervals; multi-port EPAW414, with four intermediate zone sample intervals; conventional well
SEMW09 (which is not a multi-port well and has one interval); and 12 conventional compliance
monitoring wells or well pairs (SEMW10, SEMW11, SEMW12, SEMW13A/13B, SEMW14,
SEMW15A/15B, SEMW16A/16B and SEMW17A/17B). The wells are all monitored for water levels
and groundwater quality. Locations of the monitoring wells that are included in the compliance
monitoring program are shown on Figure 4-1, and their monitoring frequencies are listed in Table 6-9.
Remedy implementation is being conducted by the water companies under the oversight of EPA,
WQA and CDPH (CH2M HILL, 2013). The CDPH permits specify the allowable operating
parameters and the extensive water quality monitoring required to demonstrate that the treatment
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
6-7
-------
systems are operating as intended and consistently producing water that meets all drinking water
requirements. Each of the three water purveyors has prepared CDPH-approved Operations,
Monitoring and Maintenance Plans (OMMPs) for the treatment systems that describe the specific
routine and non-routine procedures to be followed to ensure compliance with the CDPH permits,
including water quality monitoring. The samples collected in accordance with the extensive water
quality monitoring requirements prescribed by CDPH in the drinking water permits are all submitted
to state-certified laboratories for analysis by designated drinking-water method. WQA prepares
quarterly and annual remedy performance reports that include results from samples collected at the
wellheads for the remedy extraction wells (prior to treatment).
Over the last two years, EPA Contractor ITSI has installed compliance monitoring wells, collected
groundwater level and groundwater quality data, and evaluated remedy performance. In April 2012,
ITSI prepared a report documenting the compliance well installation efforts and presenting an initial
evaluation of interim remedy performance (ITSI, 2012). This initial report only included data from the
first water level and water quality monitoring event conducted at the new compliance monitoring
wells. In addition, the report did not include the use of a numerical model of groundwater flow to
support the hydraulic evaluation (e.g., capture zone analysis) of the remedy.
ITSI completed a more thorough evaluation of remedy performance and comparison to IROD
performance criteria that makes use of three additional semi-annual groundwater monitoring events
and includes computer groundwater flow modeling results evaluating hydraulic control (ITSI, 2013).
The following sections summarize the conclusions and recommendations presented in that report
based on data collected from the compliance monitoring wells installed in 2011, sampling of existing
groundwater monitoring wells, four rounds of sampling the new groundwater monitoring wells,
quarterly water level sounding events for new and existing monitoring wells, and the expanded capture
zone analysis.
Contaminant Distribution in the Intermediate Aquifer
The groundwater flow direction in the vicinity of the target containment areas is generally to the west.
Downgradient of the extraction systems, flow directions appear to be to the northwest, toward the City
of Alhambra, where other water purveyors are extracting groundwater.
The lateral extent of VOC contamination (primarily represented by PCE concentrations) is considered
to be adequately characterized immediately downgradient of the western extraction system and also
along the southern boundary of the contaminated area, thus establishing the target capture zone for the
extraction systems. Figures 6-5 and 6-6 show the extent of PCE contamination based on the results of
the October 2012 sampling event in the Intermediate Aquifer and the Upper Intermediate Aquifer,
respectively.
Based on the October 2012 sampling results, the lateral extent of the plume also appears to be well-
defined (as represented by PCE concentrations less than the MCL) along the northwestern boundary of
the plume, which is downgradient of the central extraction system and cross-gradient of the western
extraction system. However, there is some uncertainty in this area because previous results in 2011
6-8
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
and May 2012 showed PCE concentrations slightly above the MCL. In addition, the 2012 sampling
result at one SEMW08 port (SEMW08_04) was slightly above the MCLs and the duplicate result was
slightly below the MCL (see Figure 6-6 and Table 6-10).
The vertical extent of VOC contamination is generally well defined along the boundaries of the South
El Monte OU target areas. However, the vertical extent is not fully characterized in the central portion
of target area or upgradient near the source areas. New monitoring wells were installed in these areas
in early 2013 (see Figure 4-1) with screened intervals extending down to approximately 500 feet bgs.
Initial sampling results from the new deeper monitoring wells indicate that contaminant levels are
either nondetect or below MCLs. If subsequent sampling confirms the initial results, the vertical extent
of contamination will have been defined. These new deeper wells will also facilitate evaluation of the
influence that deeper extraction wells may be having on contaminants migrating deeper into the
intermediate zone.
The lateral and vertical extent of perchlorate exceeding the MCL of 6 pg/L and 1,4-dioxane exceeding
the NL of 1 pg/L are considered adequately characterized. Table 6-10 includes perchlorate and 1,4-
dioxane concentrations in the South El Monte OU. The highest concentrations of perchlorate were
found in downgradient Wells SEMW15A (3.5 (ig/L) and SEMW16A (3.4 pg/L), mid-plume Well
SEMW11 (6.3 lig/L), and upgradient Well SEMW02_02 (4.2 pg/L). Figure 6-7 shows the distribution
of perchlorate in the Intermediate Aquifer. The highest concentrations of 1,4-dioxane were found in
upgradient Well SEMW02_02 (1.2 (ig/L) and cross-gradient Well SEMW12 (0.91 ]ig/L). All
downgradient wells had 1,4-dioxane concentrations below the reporting limit of 0.5 pg/L (see
Table 6-10).
Compliance with IROD Performance Criteria/ Capture Zone Analysis
The groundwater extraction systems appear to be operating in compliance with the IROD performance
criteria. The expanded capture zone analysis (including use of a numerical groundwater flow model
and potentiometric surface maps from four quarters of sampling events), indicates that the extraction
systems are achieving complete capture of the affected groundwater above VOC MCls ("target areas")
in both the central and western areas. The overall "target area" is shown in Figure 6-8. The only
uncertainty is in the area west/northwest of Wells SEMW17A/17B, where PCE concentrations have
recently dropped below MCLs, and a consistent contaminant trend has not been observed.
The estimated capture zone generated from the groundwater flow model extends approximately 1,500
to 2,000 feet beyond the targeted capture zone (see Figure 6-8). Ongoing monitoring, including from a
newly installed sentinel well downgradient of Wells SEMW17A/17B will provide data on water
quality and flow conditions in this area to better substantiate the model predictions.
The potentiometric surface map shown for February 2012 (see Figure 6-8) and maps prepared for the
subsequent three quarterly water level sounding events in 2012 (ITSI, 2013) indicate that the
extraction systems are operating as designed and providing containment beyond the boundary of the
monitoring network.
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
6-9
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Ongoing water quality monitoring in the compliance monitoring wells will be necessary for evaluation
and confirmation of concentration trends observed in Wells SEMW17A/17B and SEMW08 (see
Table 6-10). Additional data collected during the recent (2012-2013) installation of new monitoring
wells, as well as future monitoring results from these wells, is expected to address the remaining data
gaps related to the total depth of VOC contamination and conditions to the west/northwest of Wells
SEMW17A/17B.
6.4.2. Richwood OU
Data for the Richwood OU after the acquisition of RMWC by SGVWC in 1999 are limited. The Main
San Gabriel Basin Watermaster's Draft Five-Year Water Quality and Supply Plan (2012-2013)
(Watermaster, 2012) includes pumping and water quality data for the HMWC and RHMWC
production wells for the 2011-2012 water year, as summarized below.
The HMWC North/1901178 well has a capacity of 136 gpm and produced approximately 31 acre-feet
during the 2011-2012 water year. Water quality results indicate the HMWC North/1901178 well was
nondetect for PCE and TCE in September 2011 and perchlorate in September 2010. The HMWC
South/1902806 well has a capacity of 320 gpm and produced approximately 58 acre-feet during the
2011-2012 water year. Water quality results indicate the HMWC South/1902806 well was nondetect
for PCE in March 2012, TCE in September 2011, and perchlorate in September 2010.
RHMWC Well l-North/1900120 has a capacity of 450 gpm and produced approximately 199 acre-feet
during the 2011-2012 water year. Water quality results indicate the RHMWC North 1/1900120 well
was nondetect for PCE and TCE in March 2012 and perchlorate in September 2010. RHMWC
Well 2-South/l900121 has a capacity of 300 gpm and produced approximately 87 acre-feet during the
2011-2012 water year. Water quality results indicate the RHMWC South 2/1900121 well was
nondetect for PCE and TCE in March 2012 and perchlorate in June 2011.
Based on these recent data for HMWC and RHMWC wells, the water quality in the Richwood OU
continues to meet drinking water standards.
6.4.3. Suburban OU
The most recent pumping status and groundwater quality sampling results, as available, for the active
wells in the SWS Bartolo Well Field compiled by the Watermaster (2012) indicate the following:
• Well 201W-4 - TCE and PCE were not detected in February 2009 and perchlorate was not
detected in August 2010. Note the Watermaster reports this well as destroyed, however SWS
reports the well is active.
• Well 201W-7 - PCE was not detected in June 2012 and perchlorate was not detected in August
2011.
• Well 201W-8 - TCE was not detected in May 2012 and perchlorate was not detected in August
2011.
6-10
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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• Well 201W-9 -PCE was not detected in May 2012 and perchlorate was not detected in September
2011.
• Well 201W-10 (active) - The TCE concentration was 0.7 (ig/L, the PCE concentration was 0.8 ]ig/L
in June 2012, and perchlorate was not detected in May 2011.
Available data for 2010 through 2012 provided by SWS indicate wells 201W-7, 201W-8, 201W-9,
and 201W-10 did not contain 1,4-dioxane above the CDPH reporting limit of 1 ju.g/L.
Based on these recent data for the SWS Bartolo Well Field production wells, the water quality in the
Suburban OU continues to meet drinking water standards.
ispection
Site inspections were conducted on March 20, 2013, by the EPA Project Manager, and CH2M HILL,
EPA's Contractor. The purpose of the inspections was to observe the current condition of the remedy
components and discuss system operations with operations staff.
Site inspections were conducted at the following facilities in the South El Monte OU:
• SGVWC Plant 8 Facility
• GSWC San Gabriel Facility
• MP Well 12/15 Facility
• MP Well 5 Facility
The inspections found these four treatment facilities to be in good condition and operating as reported.
Some relatively minor issues were noted with the operation of these systems, as described in
Section 4.3 of this FYR report.
The SWS Bartolo Well Field in the Suburban OU and the former RMWC treatment facility location in
the Richwood OU were also visually inspected and photographed. The Bartolo Well Field is active
and no issues were noted. Inspection of the former RMWC treatment facility location confirmed that
the facility no longer exists and no issues were noted.
The site inspection checklists and inspection photographs are provided in Appendix C.
6,6, Interviews
Site interviews were conducted with the following personnel:
• Chris Arriola, MP - February 21, 2013
• Craig Gott, Vice President of Engineering, John Brettl, Ken Reich, and Josh Vaughn, Quality
Assurance Department, and Kevin Hostert, Production Department, SWS - February 25, 2013
• David Chang, Vice President, Environmental Quality, GSWC - February 27, 2013
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
6-11
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• Frank LoGuidice, Vice President, Engineering and Operations, Dan Arrighi, Vice President, Water
Quality and Planning, and Oscar Ramos, Water Quality Superintendent, SGVWC - February 27,
2013
• Tony Zampiello, Executive Officer, Watermaster, and Steve Johnson, Stetson Engineers -
February 28, 2013
• Ken Manning, Executive Director, and Randy Schoellerman, Assistant Executive Director,
WQA-March 15, 2013
• Mike Cox, RHMWC - May 7, 2013
The purpose of the interviews was to document perceptions about problems or successes at the Site
and remedial activities implemented to date. Common concerns expressed by the three water
purveyors which could potentially affect performance of the South El Monte OU remedy include:
• Viability of aging production wells up to 60 years old and associated shutdowns due to
maintenance, repairs, and potential failure requiring well replacement
• Achieving EPA's target pumping rates relative to system operational capacity and relatively lower
water system demands
• Presence of 1,4-dioxane and perchlorate at concentrations relatively close to (or exceeding)
standards
• Potential for new lower MCLs and NLs for contaminants including 1,4-dioxane, perchlorate,
hexavalent chromium, and PCE
Chris Arriola indicated that MP is also concerned about the higher-than-expected PCE concentrations
in MP Well 15 and is proceeding with plans to consolidate all treatment to a centralized plant at the
Delta facility that will include ultraviolet light/oxidation (UV/Ox) treatment for 1,4-dioxane and
VOCs and an LGAC dual barrier. The City is proceeding through the Proposition 218 process for a
water rate increase to fund the new treatment system, which is expected to cost $7 to $8 million.
David Chang explained that GSWC's CDPH-approved nitrate blending plan restricts the pumping rate
from GSWC's SG2 to 300 gpm and requires that Well SGI also be operating for Well SG2 to operate.
If Well SGI fails the system would need to be shut down. This possibility is a concern to GSWC.
Frank LoGuidice, Dan Arrighi, and Oscar Ramos of SGVWC requested specific acknowledgment that
the minimum pumping target rates for Plant 8 can be achieved through pumping of any combination of
the three remedy Wells 8B, 8C and 8D, rather than the well-specific rates included in the Cooperative
Agreement. To address perchlorate concentrations approaching levels of concern, SGVWC has an on-
the-shelf design and has identified a footprint at Plant 8 for adding perchlorate treatment that will be
implemented if concentrations increase.
SGVWC also provided details on their acquisition of the former RMWC's water rights and assets.
6-12
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
For the Suburban OU, Craig Gott of SWS expressed concerns regarding the potential for future
increases in 1,4-dioxane concentrations relative to the persistent low detections (1 pg/L or less) in all
production wells in the Bartolo Well Field. SWS destroyed older production Wells 201W2 and 201W3
in 2005, 201W2 and 201W6 in 2008, and 201W5 in 2005, which were replaced with new production
wells. SWS would concur with delisting the Suburban OU, if EPA were to propose it.
Ken Manning and Randy Schoellerman of WQA expressed concerns about 1,4-dioxane in the South
El Monte OU and noted that it should be addressed in the Final ROD. WQA has had discussions with
the water purveyors and the WQA Board about long-term administration of the South El Monte OU
and what funding options there may be beyond the existing settlement funds and EPA's current
commitments. WQA endorses delisting the Suburban and Richwood OUs.
Tony Zampiello of the Watermaster and Steve Johnson of Stetson Engineers on behalf of the
Watermaster provided contact information for representatives of the HMWC and RHMWC in the
Richwood OU. Steve Johnson provided a summary of recent (and historical) contaminant
concentrations and production rates for both HMWC and RHMWC. The Watermaster does not have
concerns about the Richwood or Suburban OUs.
Mike Cox of RHMWC in the Richwood OU reported that RHMWC continues to supply water to
300 homes located in the northern portion of the City of El Monte and never needed to install a
treatment system to remove VOCs. RHMWC has no opposition to EPA delisting the Richwood OU.
Interview reports are provided in Appendix D.
6.7. Institutional tls
The September 2000 South El Monte OU IROD discusses groundwater management and associated
governmental controls that affect the extraction and use of groundwater. The primary governmental
control is the judgment in the matter of Upper San Gabriel Valley Municipal Water District vs. City of
Alhambra, et al, by the Superior Court of California, County of Los Angeles. This judgment
established the entity known as the Main San Gabriel Basin Watermaster (Watermaster) with authority
to regulate groundwater pumping in the San Gabriel Valley. The Watermaster has authority to manage
and restrict the use of groundwater resources in the San Gabriel Basin. The withdrawal and utilization
of water resources in the Basin are subject to the Watermaster's authority. No drinking water
production wells may be drilled without the Watermaster's approval. In conjunction, governmental
controls on the use of groundwater as drinking water, including EPA- and California-promulgated
MCLs and California NLs, require that drinking water standards be met prior to serving the water.
These drinking water controls and the Watermaster's authority to regulate water resources and
eliminate unregulated use of area groundwater, as mentioned in the RODs and IRODs for the OUs in
the Area 1 Superfund Site, serve as institutional controls (ICs) that prohibit unauthorized use of, or
exposure to, contaminated groundwater.
Table 6-11 lists the ICs associated with the Area 1 Site.
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
6-13
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Table 6-1: Summary of Changes in Chemical-Specific Standards and California Notification
Levels
Co n tn mi mints of
Concern
2000 IROD
2005
ESD
(HS/L)
Current Standard
or NotiNuition
Level (NL)
(H«/L)
Stiindiird or NL
Changed since IROD
or ESD?
Stiite
Federal
Benzene
1
-
1
5
No
1,2-DCA
0.5
-
0.5
5
No
1,2-DCE 2
-
-
-
-
No
trans-l,2-DCE
10
-
10
100
No
cis-1,2-DCE
6
-
6
70
No
1,2-DCP
5
-
5
5
No
PCE
5
-
5
5
No
TCE
5
-
5
5
No
Vinyl Chloride
0.5
-
0.5
2
No
Perchlorate
-
63
6
NA
No
1,4-dioxane
3
33
li
NA
More stringent
Notes:
1 California Notification Level
2 Standards are established for the individual cis-1,2-DCE and trans-1,2-DCE isomers
3 California drinking water advisory level
-- not established
NA - not applicable, no federal MCL
6-14
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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Table 6-2: Applicable or Relevant and Appropriate Requirements Evaluation
Requirement
Citation
Document
Description
Effect on
Protectiveness
Comments
Amendment
Diite
Safe Drinking
Water Act
National Drinking
Water Standards
(Federal
Maximum
Contaminant
Levels [MCLs])
40 CFR141
40 CFR
300.430(f)
(5)
2000
Interim
ROD
Establishes national
primary drinking water
standards, MCLs, to protect
the quality of water in
public water systems. MCLs
represent the maximum
concentrations of
contaminants permissible in
water delivered to the
public. MCLs are generally
relevant and appropriate
when determining
acceptable exposure limits
for groundwater that is a
current or potential source
of drinking water.
There have been no
revisions that affect
protectiveness.
Treated groundwater
delivered to a public water
supply system must meet all
legal requirements for
drinking water in existence
at the time the water is
served.
NA
California Safe
Drinking Water
Standards (State
MCLs)
Health and
Safety Code
Sections
4010.1(b),
4026(c)
State MCLs
found in
22 CCR
64435 and
64444.5
2000
Interim
ROD
Establishes primary MCLs
for contaminants that
cannot be exceeded in
public water systems.
In some cases, the California
drinking water standards
are more stringent than the
federal MCLs.
There have been no
revisions that affect
protectiveness.
Adoption of the
State MCL for
perchlorate in 2007
did not affect the
protectiveness of
the remedy, as the
same concentration
was included in the
2005 ESD.
Treated groundwater
delivered to a public water
supply system must meet all
legal requirements for
drinking water in existence
at the time the water is
served.
The perchlorate notification
level established at the time
of the ESD was 6 |ig/L. Since
then, the State of California
promulgated an MCL of
6 ng/L for perchlorate.
The effective
date for the
State MCL for
perchlorate
is October 18,
2007.
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
6-15
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Table 6-2: Applicable or Relevant and Appropriate Requirements Evaluation
Effect on
Amendment
Requirement
Citation
Document
Description
Protectiveness
Comments
Diite
California
22 CCR
2005 ESD
Safe levels for some
The 2005 ESD cited
1,4-Dioxane has been
The effective
Domestic Water
64401
chemicals that lack MCLs
the perchlorate NL;
detected in the South El
date for the
Quality
California
are specified by notification
however there is
Monte OU since 2000.
revised 1,4-
Monitoring
Health &
levels. Drinking water
now an MCL for
However, concentrations
dioxane
Regulations
Safety Code
systems provide public
perchlorate. The
have not been high enough
notification
California
Section
notification if notification
2005 ESD
to require treatment. The
level is
Notification
116455
levels are exceeded, unless
referenced the 1,4-
lowering of the NL,
August 2 2,
Levels
the wells in question are
taken out of service.
Although not an enforceable
standard and not an ARAR, a
notification level is the
concentration of a
contaminant in drinking
water that CDPH has
determined, based on
available scientific
information, to provide an
adequate margin of safety to
prevent potential risks to
human health.
dioxane NL, but did
not add 1,4-dioxane
treatment to the
remedy. Since the
2005 ESD, the 1,4-
dioxane notification
level was decreased
from 3 ng/L to
1 [J-g/L.
This change does
not currently impact
the protectiveness
of the remedy
because the water
being served to
customers does
meet the NL
increases the likelihood that
1,4-dioxane treatment could
be required in the future.
1,4-Dioxane has been
detected in some remedy
production wells at
concentrations above
1 [J-g/L.
2010.
6-16
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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Table 6-2: Applicable or Relevant and Appropriate Requirements Evaluation
Effect on
Amendment
Requirement
Citation
Document
Description
Protectiveness
Comments
Diite
Water Quality
Porter-
2000
Requires that high-quality
There have been no
Treated groundwater
There have
Control Plan
Cologne
Interim
surface water and
revisions that affect
discharged to land,
been multiple
(Basin Plan) for
Water
ROD
groundwater be maintained
protectiveness.
groundwater, or surface
basin plan
the Los Angeles
Quality
to the maximum extent
water, including recharge at
amendments
Region
Control Act
possible. Degradation of
a spreading basin, must be
since the
State Water
(California
waters will be allowed only
treated to meet established
2000 Interim
Resources Control
Water Code
if it is consistent with the
numeric water quality
ROD.
Board Resolution
Sections
maximum benefit to the
objectives, including federal
No. 68-16
13240,
people of the state, does not
or state MCLs, whichever is
(Antidegrada-tion
13241,
unreasonably affect present
more stringent, except for
Policy)
13242,
and anticipated beneficial
EPA-approved CERCLA
13243)
uses, and does not result in
Section 104(b) activities
water quality less than that
prescribed in State Water
Board policies. If
degradation is allowed, the
discharge must meet best
practicable treatment or
control, which must prevent
pollution or nuisance and
result in the highest water
quality consistent with
maximum benefit to the
people of the state.
that will result in temporary
high flow, high volume
discharges.
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
6-17
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Table 6-2: Applicable or Relevant and Appropriate Requirements Evaluation
Requirement
Citation
Document
Description
Effect on
Protectiveness
Comments
Amendment
Diite
National Pollution
Discharge
Elimination
System
California Toxics
Rule
40 CFR
Parts 122,
123,124,
40 CFR Part
131
Cal. Water
Code
Section
13263
2000
Interim
ROD
Regulates discharges to
surface water. Applicable to
discharge of treated
groundwater.
The California Toxics Rule
establishes permit limits for
new or revised NPDES
permits.
In establishing effluent
limitations for such
discharges, the Regional
Board typically considers
the Basin Plan, which
incorporates Resolution 68-
16.
There have been no
revisions that affect
protectiveness.
Each of the three water
purveyors implementing the
South El Monte OU interim
remedy maintains an active
NPDES permit that covers
any discharges of treated
water to surface water.
These discharges are
generally limited to
backwash water that is
generated after carbon
changeouts.
NA
California
Hazardous Waste
Control Act
22 CCR
66261,
66262,
66268
2000
Interim
ROD
In lieu of the federal RCRA
program, the State is
authorized to enforce its
Hazardous Waste Control
Act and implement
regulations subject to EPA
authority (CCRTitle 22,
Division 4.5).
Wastes can be classified as
non-RCRA, state-only
hazardous wastes if they
exceed the soluble threshold
limit concentration or total
threshold limit
concentration values.
There have been no
revisions that affect
protectiveness.
Potentially applicable to
waste streams associated
with treatment operations
that include, but are not
limited to, spent granular
activated carbon and spent
ion exchange (IX) resins.
If waste is determined to be
hazardous, the
requirements for handling
such waste set forth in
Sections 66262 and 66268
are applicable.
NA
6-18
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
Table 6-2: Applicable or Relevant and Appropriate Requirements Evaluation
Requirement
Citation
Document
Description
Effect on
Protectiveness
Comments
Amendment
Diite
Operation,
maintenance, and
closure
requirements for
treatment units
22 CCR
66264.601-
.603
22 CCR
Sections
66264.111-
.115
2000
Interim
ROD
These regulations include
design, operation,
maintenance, and closure
requirements for
miscellaneous treatment
units and units that use
chemical, physical, or
biological treatment
methods to treat hazardous
waste.
There have been no
revisions that affect
protectiveness.
Potentially relevant and
appropriate to air strippers
or granular activated carbon
contactors.
If units are used to treat
water containing hazardous
waste, the requirements set
forth in Sections 66264.601-
.603 and66264.lll-.115
are relevant and
appropriate.
NA
Container Storage
Requirements
22 CCR
66264.170-
.178
2000
Interim
ROD
Establishes requirements
for the storage of
contaminated groundwater
over 90 days.
There have been no
revisions that affect
protectiveness.
Potentially relevant and
appropriate for the storage
of contaminated
groundwater over 90 days.
If groundwater is
determined to be
hazardous waste, the
requirements set forth in
Sections 66264.170 -.178
are relevant and
appropriate.
NA
Land Disposal
Restrictions
22 CCR
66268
2000
Interim
ROD
Relevant and appropriate to
discharges of contaminated
or treated groundwater to
land, including the
discharge of treated water
to spreading basins.
There have been no
revisions that affect
protectiveness.
Waters must be treated to
meet federal or state MCLs,
whichever is more stringent,
prior to discharge to land.
If groundwater is
determined to be hazardous
waste, the requirements set
forth in Section 66268 are
relevant and appropriate.
NA
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
6-19
-------
Table 6-2: Applicable or Relevant and Appropriate Requirements Evaluation
Requirement
Citation
Document
Description
Effect on
Protectiveness
Comments
Amendment
Diite
Clean Air Act
Rules and
Regulations of the
South Coast Air
Quality
Management
District
(SCAQMD)
42 U.S.C.
section
7401 etseq.
SCAQMD
Regulation
XIV, Rule
1401
SCAQMD
Rules 401,
402,403
2000
Interim
ROD
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
are implemented primarily
through Air Pollution
Control Districts. The
SCAQMD regulates air
quality in the San Gabriel
Valley.
There have been
revisions since the
2000 Interim ROD.
However, none of
the revisions affect
protectiveness.
Two of the treatment plants
incorporated into the South
El Monte OU interim remedy
(MP Well 12/Welll5 and
SGVWC Plant 8) include air-
stripping towers and
associated VGAC off-gas
treatment units for VOC
removal. MP and SGVWC
both have active SCAQMD
permits that cover the air
strippers and off-gas
treatment units. SCAQMD
reviews the permits each
year. Planned new
construction for
consolidating treatment at
the Delta Plant and possible
perchlorate treatment
addition at the SGVWC
Plant 8 facility may be
subject to the amendments.
Visible
Emissions
amended
November 9,
2001.
Fugitive Dust
amended
June 3, 2005.
Notes:
ASR applicable state requirement
CCR California Code of Regulations
CFR Code of Federal Regulations
NA not applicable
SCAQMD South Coast Air Quality Management District
U.S.C. United States Code
6-20
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
Exposure Scenario & Pathway
Risk Driver(s)
Rcingc of Risk Estimates
South El Monte OU HHRA
RME Residential
Scenario/Ingestion/Inhalation
Benzene, 1,2-DCA, 1,2-DCE,
cis-l,2-DCE, 1,2-DCP, PCE,
TCE, vinyl chloride
2 x 10"6 to 9 x 10"4
RME Residential Scenario/Inhalation
VOCs via indoor air
VOCs
1 x lO 9 to 9 x lO 6
Suburban Water Systems/Bartolo Well Field OU HHRA
RME Residential
Scenario/Ingestion/Inhalation
TCE and PCE
5 x lO 7 to 2 x lO 6
Note:
RME = Reasonable Maximum Exposure
Source: South El Monte OU ROD (September, 2000); Suburban Water Systems/Bartolo Well Field
OU HHRA (July, 1992)
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
6-21
-------
This page is intentionally left blank.
6-22 Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
Table 6-4: Comparison Between Toxicity Values in Preliminary Risk Assessments and Current Region 9 Values
Chemical
Ingestion Exposure
Inhalation Exposure
Reference Dose Oral (RfDo)
(mg/kg/day)
Cancer Slope Factor Oral (SFo)
(mg/kg/day)1
Reference Dose Inhalation (RfDi)
(mg/kg/day)
Cancer Slope Factor Inhalation (SFi)
(mg/kg/day)1
Preliminary
HHRA Values
Current
Values2
Impact on
Estimated
Hazard
Preliminary
HHRA Values
Current
Values2
Impact on
Estimated
Risk
Preliminary
HHRA Values
Current
Values2
Impact on
Estimated
Hazard
Preliminary
HHRA Values
Current
Values2
Impact on
Estimated
Risk
South El Monte OU HHRA1
Benzene
0.0011
NCEA
0.004
I
decrease
0.029
I
0.1
C
increase
0.0017
NCEA
0.0086
I
decrease
0. 029
I
0.1
C
Increase
1,2-Dichloroethane
0.01
NCEA
0.006
X
increase
0. 091
I
0. 091
I
--
0.0029
NCEA
0.002
P
increase
0.091
I
0. 091
I
--
1,2-Dichloroethene
0. 006
H
0. 009
H
decrease
--
--
--
--
--
0.009
R
0.009
R
--
--
--
--
--
--
cis-l,2-Dichloroethene
0. 0017
H
0.002
I
decrease
--
--
--
--
--
0.01
R
0.002
R
increase
--
--
--
--
--
1,2-Dichloropropane
0. 0029
R
0.09
A
decrease
0. 068
H
0.036
C
decrease
0. 0011
I
0.00001
I
increase
0. 068
R
0. 036
C
Decrease
Tetrachloroethene
0. 009
I
0.006
I
increase
0. 052
NCEA
0. 54
C
increase
0.01
R
0.011
I
increase
0. 002
NCEA
0. 021
C
Increase
Trichloroethene
0.01
NCEA
0.0005
I
increase
0.011
NCEA
0. 046
I
increase
0. 006
R
0. 00057
I
increase
0. 006
NCEA
0.014
I
Increase
Vinyl Chloride
--
I
0.003
I
increase
1.9
H
0. 72
I
decrease
--
--
0.029
I
increase
0.3
H
0.27
C
Decrease
Suburban Water Systems/Bartolo Well Field OU HHRA3
1,1-Dichloroethene
0. 0009
H
0.05
I
decrease
0.6
I
--
--
decrease
--
--
0.057
I
increase
1.2
H
--
--
decrease
1,1-Dichloroethane
0.11
H
0.2
P
decrease
--
--
0.0057
C
increase
--
--
0.2
R
increase
--
--
0. 0057
C
increase
cis-l,2-Dichloroethene
0. 001
H
0.002
I
decrease
--
--
--
--
--
--
--
0.002
R
increase
--
--
--
--
--
Chloroform
0. 002
H
0.01
I
increase
0.0061
H
0. 031
C
increase
--
--
0. 028
A
increase
0.081
H
0. 081
I
--
1,1,1-Trichloroethane
0. 09
H
2
I
decrease
--
--
--
--
--
0.3
H
1.4
I
decrease
--
--
--
--
--
T etrachloroethene
0.002
H
0.006
I
decrease
0.051
H
0. 54
C
increase
--
--
0.011
I
increase
0.0018
H
0. 021
C
increase
Trichloroethene
0. 006
E
0.0005
I
increase
0.011
H
0. 046
I
increase
--
--
0.00057
I
increase
0.017
H
0.014
I
increase
Notes:
1 EPA, Region 9. September 2000. Record of Decision. South El Monte Operable Unit. Los Angeles County, California.
2 Current value is the most conservative value between EPA RSLs (2012) and OEHHA Toxicity Criteria Database toxicity values. EPA. 2012. Regional Screening Levels (RSL) Table. November. Online: http://www. epa. gov/region9/superfund//prg/index.
html; California Environmental Protection Agency (Cal-EPA) Office of Environmental Health Hazard Assessment's (OEHHA's) Chronic Reference Exposure Levels (RELs] from December 2008 and the Cancer Potency Values from July 21,2009)
3 EPA, Region 9. July 1992. Suburban Water Systems/Bartolo Well Field OU Screening Risk Assessment.
A = Agency for Toxic Substances and Disease Registry (ATSDR) Minimal Risk Levels (MRLs)
C = California Environmental Protection Agency (Cal-EPA) Office of Environmental Health Hazard Assessment's (OEHHA's) Chronic Reference Exposure Levels (RELs) from December 2008 and the Cancer Potency Values from July 21, 2009)
E = Environmental Criteria and Assessment Office (ECAO)
H = Health Effects Assessment Summary Tables (HEAST)
I = Integrated Risk Information System (IRIS)
NCEA = National Center for Environmental Assessment (NCEA)
P = Provisional Peer Reviewed Toxicity Values (PPRTVs)
R = Route Extrapolation
X = PPRTV Appendix H
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
6-23
-------
This page is intentionally left blank.
6-24 Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
Table 6-5: Summary of Drinking Water RSts for Contaminants of Concern
Co n fo mi mint of
Concern
RSL for excess ameer risk
level of 1x10 ''
(H«/L)
RSL for nonanicer hii/iird
TCE
0. 44
2. 6
PCE
9. 7
35
Table 6-6. South El Monte Oil Remedy Wells Annual Extraction Rates Compared to Target Rates
Remedy Well
lll'A Til ryot
Annual
KiltOS (illTO-
feet/yea r)
Actual Annual I'uinpin^ Rates (acre-feet/year)1
2008-
2009
2010
2011
2012
2013 f
MP 5
209
647
1,774
922
1,081
1,051
154
MP 12
3,226
1,091
3,306
3,246
2,930
3,213
800
MP 15
3,091
551
1,782
1,954
2,303
2,632
711
MP T otal
6,526
2,289
6,861
6,140
6,314
6,897
1,665
GSWC SGI
828
462
1,333
1,283
1,209
1,473
388
GSWC SG2
579
0
0
0
0
168
97
GSWC Total
1,407
462
1,333
1,283
1,209
1,641
485
SGVWC 8B
0
39
179
15
10
4
1
SGVWC 8C
1,353
69
412
641
1,029
924
128
SGVWC 8D
322
381
1,441
1,331
1,889
2,130
238
SGVWC Total
1,674
489
2,031
1,987
2,927
3,058
367
Total
9,607
3,240
10,225
9,410
10,450
11,596
2,517
Source: San Gabriel Basin Water Quality Authority Revised Performance Reports, Superfund Support Agency
Cooperative Agreement (V-96923701-0), South El Monte OU.
1: Pumping rates rounded to the nearest acre-foot
2: 2008 includes September through December
3: 2013 includes January through March. The last available performance report at the time of the FYR was the
1st Quarter 2013 reporting period performance report.
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
6-25
-------
Table 6-7. South El Monte Oil Remedy Wells Extraction Rates Compared to Target Rates
Remedy Well
lll'A Target
Annual Kates
(acre-
feet/yea r)
Actual Annual I'limping Kates (acre-feet/vear)1
Sep 2008 -
|un 2010
|ul 2010 -
|un2011
|ul 2011 -
|ii 11 2012
(ill 2012-
Mar 2013
MP 5
209
2,777
1,182
950
748
MP 12
3,226
5,969
2,967
3,275
2,385
MP 15
3,091
3,691
1,461
2,710
2,070
MP T otal
6,526
12,437
5,609
6,935
5,203
GSWC SGI
828
2,428
1,042
1,491
1,187
GSWC SG2
579
0
0
0
265
GSWC Total
1,407
2,428
1,042
1,491
1,452
SGVWC 8B
0
228
8
8
3
SGVWC 8C
1,353
741
792
1,029
640
SGVWC 8D
322
2,357
1,570
1,894
1,178
SGVWC Total
1,674
3,325
2,369
2,931
1,821
Total
9,607
18,190
9,020
11,357
8,476
Source: San Gabriel Basin Water Quality Authority Revised Performance Reports, Superfund Support Agency
Cooperative Agreement (V-96923701-0), SEMOU.
1: Pumping rates rounded to the nearest acre-foot/year
6-26
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
Table 6-8. Mass of Contaminants Removed from South El Monte Oil Remedy Wells
Remedy Wo 11
Mass of VOCs Removed (lb)1
2008-
2009
2010
2011
2012
2013 f
Total
MP 5
66
169
62
82
79
14
483
MP 12
122
380
327
398
321
110
1,800
MP 13
134
443
470
651
537
192
2,672
MP T otal
321
992
859
1,131
937
316
4,955
GSWC SGI
11
26
30
35
32
14
159
GSWC SG2
0
0
0
0
0.4
1.8
3
GSWC Total
11
26
30
35
32
16
162
SGVWC 8B
15
50
7
4
1
0
78
SGVWC 8C
18
90
134
182
169
24
653
SGVWC 8D
48
187
195
333
289
63
1,169
SGVWC Total
81
326
335
518
460
88
1,899
T otals
413
1,344
1,224
1,684
1,429
420
7,016
Source: San Gabriel Basin Water Quality Authority Performance Reports, Superfund Support Agency
Cooperative Agreement (V-96923701-0), SEMOU.
1: Mass removed rounded to the nearest pound
2: 2008 includes September through December
3: 2013 includes January through March (the latest available data at the time of the FYR Report).
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
6-27
-------
Final Sampling and Analysis Plan
Remedial Action Compliance Monitoring
San Gabriel Valley Area 1 Superfund Site, South El Monte Operable Unit
Los Angeles County, California
f 6-3
iance Monitoring Program 1
Well
Screen
Interval
(feetbgs)
Aquifer Zone
Monitoring
Frequency
Other
Monitoring
Program
Summary of VOC sampling results/comments
SEMW01_01
330-340
Intermediate
Annual
ND to < MCLs, vertical extent defined
SEMW01 02
238-248
Intermediate
Semi-annual
Early Warning
> 5x MCLs, increasing
SEMW01 03
166-176
Intermediate
Annual
ND to 10x MCLs, increasing, vertical undefined
SEMW02 02
248-258
Intermediate
Semi-annual
Early Warning
> 3x MCLs
SEMW02 03
112-122
Intermediate
Annual
ND to 20x MCLs, increasing, monitors WNOU
SEMW03 02
265-275
Intermediate
Annual
> 20x MCLs, increasing, monitors WNOU
SEMW03 03
180-190
Intermediate
Semi-annual
Early Warning
> 20x MCLs, increasing, monitors WNOU
SEMW03 04
62-72
Shallow
RI
> 2x MCLs
SEMW04_01
389-398
Intermediate
Annual
ND, vertical extent defined
SEMW04_02
281-290
Intermediate
Semi-annual
at MCLs
SEMW04_03
189-198
Intermediate
Annual
ND
SEMW04_04
64-74
Shallow
RI
ND to <1 ug/L
SEMW05_01
381-391
Intermediate
Annual
> 20x MCLs, increasing, vertical extent undefined
SEMW05_02
299-309
Intermediate
Annual
> MCLs
SEMW05_03
209-218
Intermediate
Semi-annual
Early Warning
> 20x MCLs, decreasing
SEMW05_04
98-107
Shallow
RI
at MCLs
SEMW05_05
65-74
Shallow
RI
at MCLs
SEMW06_01
357-366
Intermediate
Annual
> 5x MCLs, monitors WNOU, vertical ext. undefined
SEMW06_02
270-280
Intermediate
Annual
> lOx MCLs, monitors WNOU
SEMW06_03
120-129
Shallow
RI
> 5x MCLs, decreasing
SEMW06_04
58-67
Shallow
RI
> 5x MCLs, decreasing
SEMW07_01
415-425
Intermediate
Semi-annual
Early Warning
> 3x MCLs, vertical extent undefined
SEMW07_02
285-295
Intermediate
Annual
ND
SEMW07_03
215-225
Intermediate
Semi-annual
> 3x MCLs
SEMW07_04
80-90
Shallow
RI
ND
SEMW08_01
445-455
Intermediate
Annual
ND, vertical extent defined
SEMW08_02
375-385
Intermediate
Annual
ND, vertical extent defined
SEMW08_03
305-315
Intermediate
Semi-annual
MCLs,
SEMW08_05
100-110
Shallow
RI
ND
SEMW09
260-310
Intermediate
Semi-annual
Early Warning
>10x MCLs, increasing
SEMW10
240-250*
Intermediate
Annual
Hydraulic Gradient, mid-plume area
SEMW11
290-300*
Intermediate
Annual
Hydraulic Gradient, mid-plume area
SEMW12
370-380*
Intermediate
Semi-annual
Cross-gradient monitors edge of plume
SEMW13A
240-250*
Intermediate
Semi-annual
Mid-plume, COC trend
SEMW13B
390-400*
Intermediate
Semi-annual
Mid-plume, COC trend
SEMW14
270-280*
Intermediate
Semi-annual
Hydraulic Gradient and COC trend
SEMW15A
250-260*
Intermediate
Semi-annual
Cross Gradient Sentinel
SEMW15B
420-430*
Intermediate
Semi-annual
Cross Gradient Sentinel
SEMW16A
270-280*
Intermediate
Semi-annual
Downgradient Sentinel well
SEMW16B
450-460*
Intermediate
Semi-annual
Downgradient Sentinel well
SEMW17A
240-250*
Intermediate
Semi-annual
Downgradient Sentinel well
SEMW17B
330-340*
Intermediate
Semi-annual
Downgradient Sentinel well
EPA414_01
440-450
Intermediate
Annual
WNOU Monitoring Program
EPA414_02
365-375
Intermediate
Annual
WNOU Monitoring Program
EPA414_03
270-280
Intermediate
Annual
WNOU Monitoring Program
EPA414_04
175-185
Intermediate
Annual
WNOU Monitoring Program
EPA414_05
100-110
Shallow
RI
EPA414_06
50-60
Shallow
RI
SOURCE: ITSI, 201 la, Final Sampling and Analysis Plan, Remedial Action Compliance Monitoring, San Gabriel Valley Area 1 Superfund Site, South El Monte Operable Unit, February.
* Proposed screen interval, actual completion depth will be determined after review of geophysical log and drilling cuttings.
Note Sampling frequency can be adjusted from annual to semi-annual pending results from each sampling event.
ND - COCs not detected
NS - not sampled during October 2010 sampling event (most recent sampling results shown in parenthesis)
— sample results not available
6-28
-------
Table 6-10
Water Quality Data from Compliance Monitoring and New Monitoring Wells, May 2011 to February 2013
South El Monte OU
Well
Location ID
Aquifer
(Screen Interval,
feet bgs)
Sample
Date
Tetrachloroethene
Trichloroethene
cis-1,2-Dichloroethene
1,1 -Dichloroethene
1,1 -Dichloroethane
Trichlorofluoromethane
Chloroform
Chloromethane
Methylene Chloride
1,1,2,2-Tetrachloroethane
Methyl tert-butyl ether
Vinyl Chloride
Acetone
Toluene
1,2-Dibromo-3-chloropropane
Chloroethane
1,2,3-Trichlorobenzene
2-Butanone (MEK)
Benzene
1,2,3-Trichloropropane
Perchlorate
1,4-Dioxane (P-Dioxane)
n-Nitrosodimethylamine
SEMW01
SEMW01_01
Intermediate
(330-340)
05/09/2011
2.8
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.3
<1
-
SEMW01_01
05/02/2012
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
1.2
<0.5
-
SEMW01
SEMW01_02
Intermediate
(238-248)
05/09/2011
52
1.7
<0.5
<0.5
<0.5
3.6
<0.5
<0.5
<0.5
<0.5
<2
<0.5
-
<0.5
-
<0.5
<0.5
<5
<0.5
0.0033 J
1.8
1.9
0.00031 J
SEMW01_02
10/25/2011
62
0.79
<0.5
<0.5
<0.5
0.34 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.9
0.8
-
SEMW01_02
05/02/2012
59
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
<0.005
2
0.73
<0.0022
SEMW01_02
10/19/2012
62
1 J
0.29 J
<0.5
<0.5
0.67
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
--
1.9
<0.5
--
SEMW01
SEMW01_03
Intermediate
(166-176)
05/09/2011
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
<0.3
<1.1
-
SEMW01_03
05/02/2012
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
0.21 J
<0.5
-
SEMW01
SEMW01_04
Shallow (45-
53)
05/09/2011
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
0.18 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
4.2
<1
-
SEMW01_04
10/19/2012
0.2 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
--
3.1
<0.5
--
SEMW02
Intermediate
(344-354)
05/03/2011
190
3.6
0.36 J
0.54
0.49 J
<0.5
0.23 J
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
2.8
1 J
-
SEMW02 01
(dup)
05/03/2011
220
3.7
0.32 J
0.63
0.49 J
<0.5
0.25 J
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
2.8
1
-
SEMW02_01
10/28/2011
100
2.1
0.21 J
<0.5
0.32 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
2.3
0.61 J
-
SEMW02_01
05/01/2012
130
2.7 J
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
2.3
0.94 J
-
SEMW02_01
10/17/2012
100
2.4
0.3 J
<0.5
0.5
<0.5
<0.5
<0.5
<0.5
<0.5
0.26 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
2.3
0.4 J
-
SEMW02
SEMW02_02
Intermediate
(248-258)
05/03/2011
31
5.4
4.7
0.21 J
1.7
0.76
<0.5
<0.5
<0.5
<0.5
0.4 J
<0.5
-
<0.5
-
<0.5
<0.5
<5
<0.5
0.0026 J
4.5
2.9
-
SEMW02_02
10/28/2011
12
1.9
1.8
<0.5
0.64
0.21 J
<0.5
<0.5
<0.5
<0.5
0.27 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
4.2
1.4
-
SEMW02_02
05/01/2012
25
3.4 J
3.1 J
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
<0.0052
4.2
1.8 J
<0.0022
SEMW02_02
10/17/2012
18
2.7
2.6
<0.5
0.97
0.29 J
<0.5
<0.5
<0.5
<0.5
0.28 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
4.1
1.2
-
SEMW02 02
(dup)
10/17/2012
27
3
3
<0.5
1.1
0.29 J
<0.5
<0.5
<0.5
<0.5
0.31 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
__
4.2
1.1
__
SEMW02
SEMW02_03
05/03/2011
<0.5
0.89
5.1
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
<0.3
0.9 J
-
SEMW02_03
05/01/2012
<5
<5
2.3 J
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
<0.3
0.72 J
-
SEMW02
SEMW02_04
05/03/2011
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
<0.3
<1.1
-
SEMW02_04
10/17/2012
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
--
-
-
--
SEMW03
SEMW03_01
Intermediate
(371-380)
05/03/2011
200
3.6
0.43 J
<0.5
0.32 J
<0.5
0.15 J
<0.5
<0.5
<0.5
0.4 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.4
0.9 J
-
SEMW03_01
05/09/2012
47
1.8 J
0.36 J
<2.8
<2.8
<2.8
<2.8
<2.8
<2.8
<2.8
0.22 J
<2.8
<28
<2.8
<2.8
<2.8
<2.8
<28
<2.8
-
-
0.59 J
-
SEMW03
SEMW03_02
Intermediate
(265-275)
05/03/2011
120
3
0.44 J
<0.5
0.77
<0.5
0.19 J
<0.5
<0.5
<0.5
0.27 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.4
1.2
-
SEMW03_02
05/09/2012
73
2.8 J
0.22 J
<3.7
<3.7
<3.7
<3.7
<3.7
<3.7
<3.7
0.24 J
<3.7
<37
<3.7
<3.7
<3.7
<3.7
<37
<3.7
-
-
1.1
-
SEMW03
SEMW03_03
Intermediate
(180-190)
05/04/2011
120
5.6
0.31 J
<0.5
0.88 J
<0.5
<0.5
<0.5
<0.5
<0.5
<2
<0.5
-
<0.5
-
<0.5
<0.5
<5
<0.5
0.0034 J
2
2.4
<0.002
SEMW03_03
05/04/2011
120
5.9
0.28 J
<0.5
0.89
<0.5
<0.5
<0.5
<0.5
<0.5
<2
<0.5
-
<0.5
-
<0.5
<0.5
<5
<0.5
0.0036 J
2
2.5
0.0028
SEMW03_03
10/27/2011
43
2.2
0.14 J
<0.5
0.38 J
<0.5
<0.5
<0.5
<0.5
<0.5
0.24 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.6
1.8
-
SEMW03_03
05/09/2012
70
2.7 J
0.2 J
<3.7
<3.7
<3.7
<3.7
<3.7
<3.7
<3.7
0.19 J
<3.7
<37
<3.7
<3.7
<3.7
<3.7
<37
<3.7
-
-
1.2
-
SEMW03_03
10/17/2012
41
2.1
0.19 J
<0.5
0.35 J
<0.5
<0.5
<0.5
<0.5
<0.5
0.25 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.6
0.96
<0.002
SEMW03
SEMW03_04
Shallow
(62-72)
05/04/2011
130
12
3
<0.5
1
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.8
2.6
-
SEMW03_04
10/27/2011
37
3.8 J
0.62
<0.5
0.34 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.005
1.3
2.2
<0.0023
SEMW03_04
05/09/2012
62
4.5
0.6 J
<3.2
<3.2
<3.2
<3.2
<3.2
<3.2
<3.2
<3.2
<3.2
<32
0.047 J
<3.2
<3.2
<3.2
<32
<3.2
-
-
1.6
-
SEMW04
SEMW04_01
Intermediate
(389-398)
05/06/2011
0.3 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.3
<1
-
SEMW04_01
05/01/2012
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
1.2
<0.5
-
SEMW04
SEMW04_02
Intermediate
(281-290)
05/06/2011
14
4.5
<0.5
<0.5
<0.5
1.2
<0.5
<0.5
<0.5
<0.5
0.15 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.5
0.7 J
-
SEMW04_02
10/25/2011
6.3
0.95
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
0.16 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.5
0.3 J
-
SEMW04_02
05/01/2012
20
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
1.6
<0.5
-
SEMW04 02
(dup)
05/01/2012
17
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
1.6
<0.5
-
SEMW04_02
10/16/2012
19
0.46 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.6
<0.5
-
SEMW04
SEMW04_03
Intermediate
(189-198)
05/06/2011
0.58
<0.5
<0.5
<0.5
<0.5
4
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
0.36
<1
-
SEMW04_03
05/01/2012
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
0.44
<0.5
-
lof 5
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
Table 6-10
Water Quality Data from Compliance Monitoring and New Monitoring Wells, May 2011 to February 2013
South El Monte OU
Well
Location ID
Aquifer
(Screen Interval,
feet bgs)
Sample
Date
Tetrachloroethene
Trichloroethene
cis-1,2-Dichloroethene
1,1 -Dichloroethene
1,1 -Dichloroethane
Trichlorofluoromethane
Chloroform
Chloromethane
Methylene Chloride
1,1,2,2-Tetrachloroethane
Methyl tert-butyl ether
Vinyl Chloride
Acetone
Toluene
1,2-Dibromo-3-chloropropane
Chloroethane
1,2,3-Trichlorobenzene
2-Butanone (MEK)
Benzene
1,2,3-Trichloropropane
Perchlorate
1,4-Dioxane (P-Dioxane)
n-Nitrosodimethylamine
SEMW04
SEMW04_04
Shallow
(64-74)
05/06/2011
0.41 J
3
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
2.4
<1.1
-
SEMW04_04
10/25/2011
0.16 J
0.31 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.005
2.4
<0.5
<0.0021
SEMW04_04
10/16/2012
<0.5
0.54
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
2.1
-
-
SEMW05
SEMW05_01
Intermediate
(381-391)
05/05/2011
130
0.85
<0.5
<0.5
<0.5
<0.5
0.14 J
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
2.3
<1.1
-
SEMW05 01
(dup)
05/05/2011
140
0.83
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
—
2.3
<1
—
SEMW05_01
05/02/2012
67
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
2
<0.5
-
SEMW05
SEMW05_02
Intermediate
(299-309)
05/05/2011
230
1.3
<0.5
<0.5
<0.5
<0.5
0.14 J
<0.5
<0.5
<0.5
0.16 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
2.4
<1.1
-
SEMW05_02
10/26/2011
73 J
0.77 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
0.31 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.7
0.23 J
-
SEMW05_02
05/02/2012
96
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
1.8
<0.5
-
SEMW05
SEMW05_03
Intermediate
(209-218)
05/05/2011
260
1.1
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<2
<0.5
-
<0.5
-
<0.5
<0.5
<5
<0.5
0.0072
2.4
<1.1
<0.002
SEMW05_03
10/26/2011
120 J
0.4 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
2.4
0.23 J
-
SEMW05_03
05/02/2012
160
3.3 J
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
<0.0059
2.1
<0.5
0.0016
SEMW05_03
10/18/2012
92
0.71 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
0.27 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.9
<0.5
-
SEMW05
SEMW05_04
Shallow
(98-107)
05/05/2011
11
4.6
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
0.32 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
0.55
3.6
-
SEMW05_04
10/26/2011
6.3 J
3.4 J
0.18 J
0.39 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
0.57 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.005
0.7
1.8
<0.0023
SEMW05_04
10/18/2012
3.9
1.3 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
0.17 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
--
1.9
0.51
--
SEMW05_05
Shallow
(65-74)
05/05/2011
9.2
4.4
0.42 J
<0.5
0.17 J
<0.5
<0.5
<0.5
<0.5
<0.5
0.79
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.3
4.5
-
SEMW05_05
10/26/2011
1.5 J
1.1 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
0.29 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.005
0.56
2.2
<0.0023
SEMW05_05
10/18/2012
8.3
0.94 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
0.17 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
0.68
<0.5
-
SEMW06
SEMW06_01
Intermediate
(357-366)
05/04/2011
22
1.7
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
0.21 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.5
<1.1
-
SEMW06_01
05/04/2012
3.8 J
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
1.5
<0.5
-
SEMW06 01
(dup)
05/04/2012
3.5 J
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
1.6
<0.5
-
SEMW06
SEMW06_02
Intermediate
(270-280)
04/01/2011
32
1.2
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
-
0.7
<0.002
SEMW06_02
11/01/2011
22
0.86
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<2
0.61
<0.5
SEMW06_02
04/01/2012
23
0.91
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
-
0.6
0.017
SEMW06
SEMW06_03
Intermediate
(120-129)
05/04/2011
43
1.8
<0.5
<0.5
0.14 J
0.21 J
0.21 J
<0.5
<0.5
<0.5
0.19 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.5
0.6 J
-
SEMW06_03
10/26/2011
15
0.8
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.005
1.3
0.46 J
<0.0023
SEMW06
SEMW06_04
Shallow
(58-67)
11/01/2011
11
1.1
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<2
0.73
<0.5
SEMW06_04
04/01/2011
25
1.4
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
-
0.64
<0.002
SEMW06_04
04/01/2012
11
0.86
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
-
0.88
0.023
SEMW07
SEMW07_01
Intermediate
(415-425)
05/06/2011
18
2.5
0.6
0.39 J
0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<2
<0.5
-
<0.5
-
<0.5
<0.5
<5
<0.5
<0.5
1.4
0.9 J
0.0012 J
SEMW07_01
10/24/2011
15 J
1 J
0.29 J
<0.5
0.31 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.4
0.85
-
SEMW07_01
05/03/2012
7.6
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
<0.005
0.93
<0.5
<0.0022
SEMW07_01
10/16/2012
5.5
0.69
0.19 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
--
0.73
<0.5
--
SEMW07
SEMW07_02
Intermediate
(285-295)
05/06/2011
1.3
0.33 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.1
<1
-
SEMW07_02
05/03/2012
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
0.93
<0.5
-
SEMW07
SEMW07_03
Intermediate
(215-225)
05/06/2011
13
2.4
0.75
<0.5
0.45 J
0.66
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
2.2
1
-
SEMW07 03
(dup)
05/06/2011
13
2.5
0.89
<0.5
0.5
0.52
<0.5
<0.5
<0.5
<0.5
0.12 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
—
2.1
0.9 J
—
SEMW07_03
10/24/2011
4.6 J
1 J
0.53 J
<0.5
0.3 J
0.18 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
2.4
0.62
-
SEMW07_03
05/03/2012
5.4
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
1.9
0.7 J
-
SEMW07_03
10/16/2012
5.8
1
0.47 J
<0.5
0.31 J
0.31 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
2.8
<0.5
-
SEMW07
SEMW07_04
Shallow (80-
90)
05/06/2011
0.16 J
0.38 J
0.31 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.7
<1
-
SEMW07_04
10/16/2012
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.7
-
-
SEMW08
SEMW08_01
Intermediate
(445-455)
05/09/2011
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
<0.3
<1
-
SEMW08_01
05/03/2012
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
<0.3
<0.5
-
2 of 5
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
Table 6-10
Water Quality Data from Compliance Monitoring and New Monitoring Wells, May 2011 to February 2013
South El Monte OU
Well
Location ID
Aquifer
(Screen Interval,
feet bgs)
Sample
Date
Tetrachloroethene
Trichloroethene
cis-1,2-Dichloroethene
1,1 -Dichloroethene
1,1 -Dichloroethane
Trichlorofluoromethane
Chloroform
Chloromethane
Methylene Chloride
1,1,2,2-Tetrachloroethane
Methyl tert-butyl ether
Vinyl Chloride
Acetone
Toluene
1,2-Dibromo-3-chloropropane
Chloroethane
1,2,3-Trichlorobenzene
2-Butanone (MEK)
Benzene
1,2,3-Trichloropropane
Perchlorate
1,4-Dioxane (P-Dioxane)
n-Nitrosodimethylamine
SEMW08
SEMW08_02
Intermediate
(375-385)
05/09/2011
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
0.26 J
<1.1
-
SEMW08_02
05/03/2012
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
0.43
<0.5
-
SEMW08
SEMW08_03
Intermediate
(305-315)
05/10/2011
6.3
<0.5
<0.5
<0.5
<0.5
0.22 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.4
<1
-
SEMW08_03
10/24/2011
1.9 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.4
0.05 J
-
SEMW08_03
05/03/2012
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
1.3
<0.5
-
SEMW08_03
10/16/2012
2.3
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
--
1.1
-
--
SEMW08
SEMW08_04
Intermediate
(230-240)
05/10/2011
10
<0.5
<0.5
<0.5
<0.5
1.2
<0.5
<0.5
<0.5
<0.5
0.13 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.7
<1
-
SEMW08_04
10/24/2011
4.4 J
1.3 J
<0.5
<0.5
<0.5
0.53 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.7
0.34 J
-
SEMW08_04
05/03/2012
3.7 J
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
1.5
<0.5
-
SEMW08_04
10/16/2012
6.6 J
2
<0.5
<0.5
<0.5
0.83
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
--
1.6
-
--
SEMW08 04
(dup)
10/16/2012
4.3 J
1.5
<0.5
<0.5
<0.5
0.56
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
..
1.5
—
..
SEMW08
SEMW08_05
Shallow (100-
110)
05/10/2011
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
2.1
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
0.47
<1.1
-
SEMW08_05
10/16/2012
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
1.6
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
0.42
-
-
SEMW09
SEMW09
Intermediate
(260-310)
06/16/2011
330
0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
0.012
<2
<0.5
<0.002
SEMW09
5/30/2012
210
0.33
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
0.69
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
0.012
1.4
<0.5
<0.002
SEMW10
SEMW10
Intermediate
(250-260)
06/27/2011
110 J
0.81
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
0.12 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
2.7
<2
0.003
SEMW10
10/25/2011
78
0.74
<0.5
<0.5
<0.5
0.17 J
<0.5
<0.5
<0.5
<0.5
0.15 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
0.0033 J
2.4
0.39 J
<0.0019
SEMW10
05/08/2012
61 J
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
2.4
<0.5
-
SEMW10
10/24/2012
64
0.43 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
0.07 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
2.3
<0.5
-
SEMW11
SEMW11
Intermediate
(280-290)
06/27/2011
5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.9
<2
<0.0019
SEMW11
10/25/2011
5.6
0.42 J
<0.5
<0.5
<0.5
0.33 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
0.0028 J
4.9
0.23 J
<0.0019
SEMW11 (dup)
10/25/2011
5.9
0.44 J
<0.5
<0.5
<0.5
0.33 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.005
5
0.25 J
0.0026
SEMW11
05/09/2012
7.4 J
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
6.3
<0.5
-
SEMW11 (dup)
05/09/2012
7.8 J
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
6.1
<0.5
-
SEMW11
10/24/2012
10
0.67
0.092 J
<0.5
0.19 J
0.51
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
6.3
<0.5
-
SEMW12
SEMW12
Intermediate
(370-380)
06/27/2011
<0.5
<0.5
0.59
<0.5
0.2 J
<0.5
<0.5
<0.5
<0.5
<0.5
0.067 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
4.8 J
<0.5
-
1
<2
<0.0019
SEMW12
10/25/2011
3.6
2.6
1.6
<0.5
0.76
<0.5
<0.5
0.19 J
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.005
<0.3
1.5
0.0022
SEMW12
05/08/2012
9.4 J
5 J
3.5 J
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
1.5
2.1 J
-
SEMW12
10/24/2012
7.5
3.7
2.8
0.47 J
1.4
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.4
0.6
-
SEMW12 (dup)
10/24/2012
8.1
3.8
2.8
0.47 J
1.4
0.18 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
--
1.4
0.91
--
SEMW13A
SEMW13A
Intermediate
(240-250)
06/28/2011
120
1
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
0.091 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
2.6
0.45 J
<0.0019
SEMW13A
10/26/2011
48 J
0.45 J
<0.5
<0.5
<0.5
0.19 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
0.004 J
2.6
<0.5
<0.0019
SEMW13A
05/08/2012
56 J
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
2.6
<0.5
-
SEMW13A
10/23/2012
75
0.63
<0.5
<0.5
<0.5
0.2 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
--
2.4
-
--
SEMW13B
SEMW13B
Intermediate
(390-400)
06/28/2011
0.8
<0.5
<0.5
<0.5
0.08 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1
0.92 J
<0.0019
SEMW13B (dup)
06/28/2011
0.71
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
—
1.2
<2
<0.0019
SEMW13B
10/26/2011
0.97
0.15 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.005
1.1
0.23 J
<0.0019
SEMW13B
05/08/2012
2.1 J
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
1.2
<0.5
-
SEMW13B
10/23/2012
1.4
0.25 J
0.12 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
0.27 J
<0.5
<0.5
<5
<0.5
-
1.1
<0.5
-
SEMW14
SEMW14
Intermediate
(260-270)
06/27/2011
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
5.4 J
<0.5
-
0.53
<2
<0.0019
SEMW14
10/25/2011
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
6.9
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.005
0.81
0.095 J
0.0032
SEMW14
05/07/2012
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
0.65
<0.5
-
SEMW14
10/23/2012
<0.5
0.21 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
0.54
<0.5
-
SEMW15A
SEMW15A
Intermediate
(224-234)
06/28/2011
0.18 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
4.1
<2
<0.0019
SEMW15A
10/24/2011
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.005
3.7
0.13 J
<0.0019
3 of 5
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
Table 6-10
Water Quality Data from Compliance Monitoring and New Monitoring Wells, May 2011 to February 2013
South El Monte OU
Well
Location ID
Aquifer
(Screen Interval,
feet bgs)
Sample
Date
Tetrachloroethene
Trichloroethene
cis-1,2-Dichloroethene
1,1 -Dichloroethene
1,1 -Dichloroethane
Trichlorofluoromethane
Chloroform
Chloromethane
Methylene Chloride
1,1,2,2-Tetrachloroethane
Methyl tert-butyl ether
Vinyl Chloride
Acetone
Toluene
1,2-Dibromo-3-chloropropane
Chloroethane
1,2,3-Trichlorobenzene
2-Butanone (MEK)
Benzene
1,2,3-Trichloropropane
Perchlorate
1,4-Dioxane (P-Dioxane)
n-Nitrosodimethylamine
SEMW15A
05/07/2012
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
4
<0.5
-
SEMW15A
10/22/2012
<0.5
<0.5
0.12 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
3.5
<0.5
-
SEMW15B
SEMW15B
Intermediate
(434-444)
06/28/2011
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
0.59
2.1
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
<0.3
0.17 J
<0.0019
SEMW15B
10/24/2011
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
0.39 J
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.005
<0.3
<0.5
<0.0019
SEMW15B
05/07/2012
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
<0.3
<0.5
-
SEMW15B
10/22/2012
<0.5
<0.5
0.11 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
-
-
-
SEMW16A
SEMW16A
Intermediate
(270-280)
06/29/2011
0.4 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
3.8
<2
<0.0019
SEMW16A
10/26/2011
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
0.31 J
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.005
3.7 J
0.049 J
<0.0019
SEMW16A
05/09/2012
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
3.5
<0.5
-
SEMW16A (dup)
05/09/2012
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
3.6
<0.5
-
SEMW16A
10/23/2012
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
3.4
-
-
SEMW16B
SEMW16B
Intermediate
(444-454)
06/29/2011
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
<0.3
<2
<0.0019
SEMW16B
10/26/2011
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.005
<0.3
<0.5
<0.0019
SEMW16B
05/09/2012
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
<0.3
<0.5
-
SEMW16B
10/23/2012
<0.5
<0.5
<0.5
0.086 J
0.071 J
<0.5
<0.5
<0.5
<0.5
0.065 J
<0.5
<0.5
2.5 J
<0.5
<0.5
<0.5
<0.5
<5
0.091 J
-
-
-
-
SEMW17A
SEMW17A
Intermediate
(220-230)
06/29/2011
20
0.59 J
<0.5
<0.5
<0.5
0.98
<0.5
<0.5
<0.5
<0.5
0.097 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
2.1
<2
<0.0019
SEMW17A
09/19/2011
10
0.39 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<1.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
0.0035 J
2
<0.5
R
SEMW17A
10/24/2011
9.7 J
0.36 J
<0.5
<0.5
<0.5
0.88 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
-
0.26 J
-
SEMW17A
05/07/2012
12 J
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
2
<0.5
-
SEMW17A
10/22/2012
2.6 J
0.12 J
0.097 J
<0.5
<0.5
0.36 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.2
<0.5
-
SEMW17B
SEMW17B
Intermediate
(330-340)
06/29/2011
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
16
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.2
<2
<0.0019
SEMW17B
10/24/2011
2.3 J
0.12 J
<0.5
<0.5
<0.5
0.59 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.005
1.9
0.14 J
<0.0019
SEMW17B
05/07/2012
5.9 J
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<5
<10
<5
<5
<5
<5
<10
<5
-
1.5
<0.5
-
SEMW17B
10/22/2012
3.5
0.12 J
<0.5
<0.5
<0.5
0.47 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
-
1.1
<0.5
-
New Monitoring Wells
SEMW18A
SEMW18A
Shallow
(86-96)
2/28/2013
41
28
1.5
<0.5
0.14 J
0.16 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
0.2 J
<0.5
<0.5
<0.5
<5
<0.5
<0.005
0.83
39
<0.002
SEMW18B
SEMW18B
Shallow
(144-154)
2/28/2013
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.005
<0.3
<0.5
<0.002
SEMW18C
SEMW18C
Intermediate
(240-250)
2/28/2013
2.3
4.8
<0.5
<0.5
<0.5
1.9
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.005
1.1
1.3
<0.0019
SEMW19A
SEMW19A
Intermediate
(264-274)
2/26/2013
80
0.5 J
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<10
<1
<1
<1
<1
<10
<1
<0.005
2
<0.5
<0.0019
2/26/2013
84
0.48 J
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<10
<1
<1
<1
<1
<10
<1
0.0026 J
1.9
<0.5
<0.0019
SEMW19B
SEMW19B
Intermediate
(502-512)
2/26/2013
2.1 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
0.12 J
<0.5
<0.5
<0.5
<5
<0.5
<0.005
1.7
<0.5
<0.002
SEMW20A
SEMW20A
Intermediate
(256-266)
2/26/2013
43
1.2
<0.5
<0.5
0.14 J
<0.5
<0.5
<0.5
<0.5
<0.5
0.2 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
0.0032 J
1.9
<0.5
<0.0019
SEMW20B
SEMW20B
Intermediate
(494-504)
2/26/2013
1.6 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
0.14 J
<0.5
<0.5
<0.5
<5
<0.5
<0.005
1.2
<0.5
<0.002
SEMW21A
SEMW21A
Shallow
(78-88)
2/21/2013
99
1.4
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<10
<1
<1
<1
<1
<10
<1
<0.005
1.6
<0.5
<0.0019
SEMW21B
SEMW21B
Shallow
(138-148)
2/21/2013
130
<2
<2
<2
<2
<2
<2
<2
<2
<2
<2
<2
<20
<2
<2
<2
<2
<20
<2
<0.005
1.1
<0.5
<0.002
SEMW21C
SEMW21C
Intermediate
(250-260)
2/21/2013
50
0.27 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
0.15 J
<0.5
<0.5
<0.5
<5
<0.5
0.014
2.7
<0.5
<0.0019
4 of 5
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
Table 6-10
Water Quality Data from Compliance Monitoring and New Monitoring Wells, May 2011 to February 2013
South El Monte OU
Well
Location ID
Aquifer
(Screen Interval,
feet bgs)
Sample
Date
Tetrachloroethene
Trichloroethene
cis-1,2-Dichloroethene
1,1 -Dichloroethene
1,1 -Dichloroethane
Trichlorofluoromethane
Chloroform
Chloromethane
Methylene Chloride
1,1,2,2-Tetrachloroethane
Methyl tert-butyl ether
Vinyl Chloride
Acetone
Toluene
1,2-Dibromo-3-chloropropane
Chloroethane
1,2,3-Trichlorobenzene
2-Butanone (MEK)
Benzene
1,2,3-Trichloropropane
Perchlorate
1,4-Dioxane (P-Dioxane)
n-Nitrosodimethylamine
SEMW22A
SEMW22A
Intermediate
(252-262)
2/27/2013
33
1
<0.5
<0.5
0.15 J
<0.5
<0.5
<0.5
<0.5
<0.5
0.16 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.005
1.4
<0.5
<0.002
SEMW22B
SEMW22B
Intermediate
(486-496)
2/27/2013
0.44 J
0.084 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
0.12 J
<0.5
<0.5
<0.5
<5
<0.5
<0.005
1.2
<0.5
<0.002
SEMW23A
SEMW23A
Intermediate
(214-224)
2/27/2013
3.5 J
0.077 J
<0.5
<0.5
<0.5
1.3 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
0.13 J
<0.5
<0.5
<0.5
<5
<0.5
0.0036 J
2.1
<0.5
<0.0019
SEMW23B
SEMW23B
Intermediate
(366-376)
2/27/2013
<0.5
<0.5
<0.5
<0.5
<0.5
0.49 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
0.12 J
<0.5
<0.5
<0.5
<5
<0.5
<0.005
0.96
<0.5
<0.0021
2/27/2013
<0.5
<0.5
<0.5
<0.5
<0.5
0.5 J
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
0.11 J
<0.5
<0.5
<0.5
<5
<0.5
<0.005
0.93
<0.5
<0.002
SEMW24A
SEMW24A
Shallow
(150-160)
2/22/2013
19
1.1
0.16 J
<0.5
0.68
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.005
1.4
1.1
<0.0019
SEMW24B
SEMW24B
Intermediate
(452-462)
2/22/2013
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.005
<0.3
<0.5
<0.002
SEMW26
SEMW26
Shallow
(75-85)
2/28/2013
1.6
92
3.9
<1
<1
<1
<1
<1
<1
<1
<1
<1
<10
<1
<1
<1
<1
<10
<1
<0.005
0.5
<0.5
<0.002
SEMW27
SEMW27
Shallow
(110-120)
2/21/2013
39
6.6
3.6
<0.5
1.5
0.17 J
<0.5
<0.5
<0.5
<0.5
0.24 J
<0.5
<5
<0.5
<0.5
<0.5
<0.5
<5
<0.5
<0.005
5.2
1.2
<0.002
SEMW28
SEMW28
Shallow
(75-85)
2/28/2013
5,000
<100
<100
<100
<100
<100
<100
<100
<100
<100
<100
<100
<1000
<100
<100
<100
<100
<1000
<100
<0.005
1.3
0.45 J
<0.0019
MCL
5
5
6
6
5
150
100
None
5
None
13
0.5
None
150
None
None
None
None
None
0.005a
6a
la
0.01a
Notes:
All results in micrograms per liter (|j.g/L)
Positive results in bold
Results above MCLs highlighted
feet bgs - feet below ground surface
MCL = EPA or California Maximum Contaminant Level (whichever is lower); a = California Notification Level; b = California MCL for Total Chromium.
Source: ITSI, 2013
5 of 5
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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Medici
ICs Ccillotl
Tor in the
Decision
Documents
Impacted
Piircel(s)
IC
Objective
Instrument in Place
Notes
Groundwater
No
All
Regulate
groundwater
pumping and
eliminate
unregulated use of
area groundwater
January 4,1973,
judgment, as
amended,
administered by the
Main San Gabriel
Basin Watermaster
Groundwater
No
All
Protect public
health by limiting
the levels of
contaminants in
drinking water
EPA and California
promulgated MCLs
and California NLs
Treatment
systems
remove COCs
to comply
with drinking
water
standards
6-30
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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Monterey Park - Well 5 Pumping - 2011-2013
¦ Well 5 Target Pumping Rate
1,159
aaaaaaaaa
T-ic^cn*t*-ic-\cnrfr-\
Figure 6-1: Monterey Park Well 5 Comparison of Actual versus Target Pumping Rates
-------
Monterey Park - Wells 12/15 Pumping - 2011-2013
¦ Wells 12/15 Total Target Pumping Rate
a a a a a a a a a
Figure 6-2: Monterey Park Wells 12/15 Comparison of Actual versus Target Pumping Rates
-------
Golden State Water Company - Wells SG1/SG2 Pumping - 2011-2013
Wells SG1/SG2 Total Target Pumping Rate
1,187
1,190 1,219
851
721
a»
959
133
I
1,108
1,062
721
721
a
!N
a
m
a
a
rsi
a
m
a
Figure 6-3: Golden State Water Company Wells SG1/SG2 Comparison
of Actual versus Target Pumping Rates
-------
San Gabriel Valley Water Company - Wells 8B/8C/8D Pumping -
2011-2013
¦ 8B/8C/8D Total Target Pumping Rate
2,824
aaaaaaaaa
THrsiro,=^^H(Nro'=t*H
Figure 6-4: San Gabriel Valley Water Company Wells 8B/8C/8D Comparison
of Actual versus Target Pumping Rates
-------
Figure 6-5: VOC Plume in the South El Monte OU Intermediate Aquifer
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Jk Remedy Extraction Well
• Existing Intermediate Aquifer Monitoring Well
6.6 PCE concentration in ug/L
[4.3] Duplicate Sample Result
(8.1) PCE concentration in deeper monitoring
well at this location.
A/ PCE Isoconcentration Contours (ug/L)
(Dashed where inferred)
South El Monte Operable Unit Boundary
NOTES:
1) Concentration represents highest PCE
concentration from a depth range of
approximately 100 ft.msl to -70 ft. msl.
2) PCE concentrations at Remedy Extraction
Wells from June 2012. Actual depth of PCE
concentration in extraction well is unknown
due to long well screen interval of extraction well.
3) PCE concentrations are highest in VOC plume
and are considered representative of the overall
VOC plume distribution.
NOTES:
GSWC = Golden State Water Company
SGVWC - San Gabriel Valley Water Company
PCE = Tetracholorethene
Wells SEMW13, SEMW15, SEMW16, and SEMW17
are dual completion wells designated as A and B.
Background image from Microsoft Bing™, 2011. Modified from ITS I, 2013, Remedial Action 2012 Compliance Monitoring Report, San Gabriel Valley Superfund Site, South El Monte Operable Unit, April
Remedial Action Compliance Monitoring
South El Monte Operable Unit
Los Angeles County, California
VOC Plume - October 2012
Upper Intermediate Aquifer
Figure 6-6: VOC Plume in the South El Monte OU Upper Intermediate Aquifer
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r
1.4 to 1.6
Modified from ITSI, 2013, Remedial Action 2012 Compliance Monitoring Report, San Gabriel Valley Superfund Site, South Ei Monte Operable Unit, April
ERus
SEMW16A/B -
- Well ID
• -* Intermediate Aquifer Monitoring We!i
2,4 Perchlorate concentrations (in ug/L)
1.1 in shallow and deeper screen intervals.
_Range of perchlorate concentrations
1.3 to 1,6-
in multi-screen well.
-Remedy Extraction Wall
— — South Ei Monte
L — ' Operable Unit Boundary
NOTES:
ND = Not Detected
GSWC = Golden State Water Company
SGWVC = San Gabriel Valley Vteter Company
Wells SEMW13, SEMW15, SEMW16, and SEMW17
are dual completion wells designated as A and B.
Water purveyor well data from September 2012.
1,200
1,200
Feet
5 2010 NAVTEQ © AND © 2012 Microsoft Corporation
itsigSSHB
Remedial Action Compliance Monitoring 2012
South El Monte Operable Unit
Los Angeles County, California
Perchlorate Concentrations - Intermediate Aquifer
May/October 2012
Figure 6-7: Perchlorate Concentrations in the South El Monte OU Intermediate Aquifer
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"SEMW04
181.90
SGVWC 8D'
SEMW08_01
GSWC*
San Gabriel 1 and 2
f SEMW17B*
159.§5
*m.ZgARVEY'AV
¦SEMW09'
187.81
SEMW01_01
NA/NA
SEMW16B"
SEMW13B'
SEMW10'
"SEMW14'
148.99
SGVWC 8B1
SEMW07_01"
163.35
Monterey Park
Well 5*
"SEMW11
SGVWC 8C'
SEMW05_01
SEMW15B"
Monterey Park
Well 12*
Monterey Park
Well 15*
'SEMW12
189.52.
SEMW02_01
Rio
^ Hondo
\ River
SEMW06_01"
199.17
'1
SEMW03_01
197.17
Modified from ITSI, 2013, Remedial Action 2012 Compliance Monitoring Report, San Gabriel Valley Superfund Site, South El Monte Operable Unit, April
itsi <35333
Remedial Action Compliance Monitoring 2012
South El Monte Operable Unit
LosAngeies County, California
Capture Zone Analysis Results
Intermediate Aquifer - 2012
Existing Monitoring Well
—SEMW01 -< LocatbnID
187.81 -<
Groundwater Elevation in feet above
mean sea level (ms()
Remedy Extraction Well
SGVWC 8D Location ID
12g. ^ Groundwater Elevation in feet above
mean sea level (msl)
February 2012 Groundwater Elevation Contours (ft msl)
(Dashed where inferred)
February 2012 Intermediate Zone VOC Plume - MCL
" ~ Target zone of capture based on VOC MCLs
Calculated Individual Extraction Well Capture Zone
- - - Interpreted Capture Zone
Model Estimated Capture Zones:
- — Maximum Rates (Layers 4 and 5)
- - - Minimum Rates (Layers 4 and 5)
NOTES:
GSWC = Golden State Water Company
SGVWC = San Gabriel Valley V\foter Company
MCL = Maximum Contaminant Level
Wells SEMW13, SEMW15, SEMW16, and SEMW17 are
dual completion wells, indicated by A and B.
Intermediate Aquifer defined by well screen elevations from
approximately -90 ft mean sea level (msl) to -185 ft msl.
Extraction Well Operational Notes:
GSWC
San Gabriel 1 - operating @ 1,116 gallons per minute (gpm)
San Gabriel 2 - not operating
Monterey Park
MP5 - operating @ 1,579 gpm
MP 12 - operating @ 2,000 gpm
MP15 - operating @ 1,804 gpm
San Gabriel Valley V\fater Company
Well 8B - operating @ 1,400 gpm
Well 8C - operating @ 1,600 gpm
Well 8D - operating @ 3,200 gpm
Water level in production well was measured
by purveyor during monthly O&M.
* Monitors well screen interval outside elevation
range used for contours.
1,200 0 1,200
5
Feet
Figure 6-8: Capture Zones for the South El Monte OU Remedy
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7. Technical Assessment
This section presents the technical assessment of the remedies in the various San Gabriel Valley
Area 1 OUs.
sst 1 nedy functioning as intended by the
decision documents?
7.1.1. South El Monte OU Remedy
The interim remedy was designed to hydraulically contain contaminated groundwater in the
intermediate zone of the western portion of the South El Monte OU aquifer. Design, construction, and
permitting by CDPH of the four pump-and-treat projects occurred between 1999 and 2006. Operation,
maintenance, and system improvement activities have been performed since construction completion.
Based on a review of documents from the past 5 years, the project extraction wells are limiting the
migration of COCs in groundwater, and the South El Monte OU contamination has not migrated
beyond the capture zone of the downgradient extraction wells located in the western portion of the
South El Monte area. Despite the fact that two of the groundwater extraction and treatment systems
(MP Wells 12 and 15 and GSWC Wells SGI and SG2) did not consistently achieve the minimum
target extraction rates identified by EPA, hydraulic containment of the targeted areas was achieved.
MP Wells 12 and 15 did not consistently achieve the combined target rates in 2010 and 2011 and
GSWC Wells SGI and SG2 did not consistently achieve the combined target rates between 2009 and
2011.
A review of documents and the results of the site inspections and interviews indicate that the reduced
production from MP Wells 12 and 15 is primarily related to various system O&M issues that resulted
in increased downtime. The target pumping rates are fairly close to the treatment system capacity
(4,500 gpm) so there is little operational flexibility to make up for periods of increased system
downtime. The primary O&M activities that resulted in increased downtime and reduced average
pumping rates over the last few years include: MP Well 15 pump replacement and motor repairs
required because of excessive vibration, air stripper system maintenance and repairs, and dual-barrier
LGAC system carbon changeouts and associated post-changeout bacteriological detections.
The reason that total production from GSWC Wells SGI and SG2 periodically did not meet target
rates was because Well SG2 was offline for many years prior to the CDPH-approved nitrate blending
plan which was implemented in 2012. Prior to that, the system generally met the target pumping rates
using Well SGI alone. However, based on the capacity of Well SGI, in some quarters there was
almost no flexibility to make up for periods of downtime associated with either routine or nonroutine
O&M requirements. For example, if the system was down for a carbon changeout during one of the
quarters with the higher target pumping rates, there was no extra system capacity to allow for pumping
at higher rates once the system was back online. In the second quarter of 2011, the SGI well
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
7-1
-------
pump/column was replaced and the motor was rebuilt. This major repair resulted in significantly
reduced water production for the quarter.
Recent data indicate that the lateral extent of VOC contamination has largely been defined in the
northwestern portion of the contaminated area; there is some uncertainty in this area because
monitoring results from 2011 and May 2012 indicated PCE concentrations slightly above the MCL in
a well located northwest of the expected extent of contamination. The vertical extent of VOC
contamination is generally well-defined along the boundaries of the South El Monte OU target areas.
However, the vertical extent is not yet fully characterized in the central portion of the target area or
upgradient near the source areas. New monitoring wells were installed in these areas in early 2013 (see
Figure 4-1) with screened intervals extending down to approximately 500 feet bgs. Initial sampling
results from the new deeper wells indicate that contaminant levels are either very low or nondetect. If
subsequent sampling confirms the initial results, the vertical extent of contamination will have been
defined.
The Watermaster's authority to regulate water resources and eliminate unregulated use of area
groundwater, along with drinking water regulations that control unacceptable exposure to
contaminated Site groundwater, serve as effective governmental controls that supplement the remedy
and ensure protection of human health at the Site.
7.1.2. Richwood OU
The Richwood OU remedy functioned as intended until 1994, when DTSC stopped operating the
treatment system and SGVWC began supplying water from its distribution system to the RMWC
customers. The intent of the remedy to supply clean water that meets CDPH drinking water
requirements to RMWC's customers has been met continuously since 1994. HMWC and RHMWC
have also operated their respective water systems consistent with the intent of the remedy and have
consistently supplied clean water to their customers that meets CDPH drinking water requirements.
7.1.3. Suburban OU
An active remedy was never implemented in the Suburban OU because VOC contamination levels
were not high enough to trigger action. However, SWS has satisfied the intent of the remedy by
operating the Bartolo Well Field to supply clean water to its customers in accordance with CDPH
drinking water requirements.
Question 1 ¦' ¦ i 1 impti*
Clean< . ¦ dis ion Object1 ¦
at t action Still Valid?
This section only addresses the South El Monte OU remedy because the Richwood OU remedy is no
longer operating and an active remedy was never required for the Suburban OU, as described
previously.
7-2
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
7.2.1. Changes in Standards and Advisory Levels
Effective August 22, 2010, the NL for 1,4-dioxane became more stringent. 1,4-Dioxane has been
detected in South El Monte OU groundwater at concentrations above the NL. However, the NL
change does not currently impact the protectiveness of the remedy. 1,4-Dioxane concentrations at the
GSWC and SGVWC remedy production wells remain below the NL. Although the 1,4-dioxane
concentrations in the MP remedy wells have periodically exceeded the revised NL, the blended water
in the City's water supply distribution system does not exceed the NL.
SGVWC has a preliminary design for a 1,4-dioxane treatment system at Plant 8 should concentrations
increase in the future. MP has begun planning for a new centralized groundwater treatment plant. As
currently conceived, the centralized plant would be equipped to treat 1,4-dioxane if necessary.
There have been no other revisions to laws, regulations, or advisory levels that affect the
protectiveness of the remedy.
7.2.2. Changes in Exposure Pathways
No changes in exposure pathways were identified that would impact the protectiveness of the South El
Monte OU remedy, but vapor intrusion was not considered as an exposure pathway in the IROD. EPA
is currently conducting a supplemental RI/FS in the South El Monte OU that includes investigation of
vapor intrusion. During soil gas sampling at source facilities in 2011 and 2012, EPA discovered
concentrations of VOCs in soil gas at five facilities that warranted further investigation by EPA's
emergency response program. EPA conducted indoor air sampling at those commercial facilities and
nearby residences. Two of the locations, the former One Dollar Cleaners and Hytone Cleaners, had
indoor air levels of PCE that were well above screening levels, so EPA is overseeing a voluntary
cleanup at the former One Dollar Cleaners facility, and conducting a removal action at five residences
near the Hytone Cleaners facility to mitigate vapor intrusion. Additional indoor air sampling is
planned in 2013 at approximately 20 other commercial facilities. EPA plans to use the findings from
the supplemental RI/FS to support a final ROD.
7.2.3. Changes in Toxicity and Other Contaminant Characteristics
In the past 5 years, there have been a number of changes to the toxicity values for certain COCs at the
Site. The most relevant changes are to TCE and PCE.
In September 2011, EPA completed a review of the TCE toxicity literature and posted on the IRIS
both cancer and noncancer toxicity values, which resulted in lower RSLs for TCE. EPA considers the
current MCL for TCE of 5 (ig/L protective for cancer and noncancer effects as explained in
Section 5.3.2.
EPA also recently reassessed PCE toxicity literature for both cancer and noncancer effects and
released the toxicological review in February 2012. The reassessment determined that risk for cancer
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
7-3
-------
was less than previously assumed, and has raised the cancer and noncancer RSLs for PCE. Therefore,
the PCE MCL of 5 (ig/L remains protective for both carcinogenic and noncancer effects.
7.2.4. Changes in Risk Assessment Methods
There have been no changes in standardized risk assessment methodologies that could affect the
protectiveness of the South El Monte OU interim remedy.
7.2.5. Expected Progress Toward Meeting RAOs
The interim remedy established treatment levels for groundwater leaving the treatment plants, but did
not establish groundwater aquifer cleanup levels. The treatment systems continue to successfully
reduce COC concentrations to levels below the current MCLs and NLs that were specified as
treatment levels in the IROD and ESD. The remedy is preventing contaminated groundwater from
migrating into less-contaminated and uncontaminated areas and depths and reducing the impact on
downgradient water supply wells in accordance with the RAOs. EPA will determine when sufficient
information is available to develop remedial alternatives for the final remedy for the Site.
sstion 1 Informant if That
jlel Call Into Question the Protectiveness of the Remedy?
There is no other information that calls into question the protectiveness of the South El Monte OU
interim remedy.
nmary
The Richwood OU remedy functioned as intended until 1994, when DTSC stopped operating the
treatment system and SGVWC began supplying water from its distribution system to the RMWC
customers. The intent of the remedy to supply clean water that meets CDPH drinking water
requirements to RMWC's customers has been met continuously since 1994. HMWC and RHMWC
have also operated their respective water systems consistent with the intent of the remedy and have
consistently supplied clean water to their customers that meets CDPH drinking water requirements.
An active remedy was never implemented in the Suburban OU because VOC contamination levels
were not high enough to trigger action. However, SWS has satisfied the intent of the remedy by
operating the Bartolo Well Field to supply clean water to its customers in accordance with CDPH
drinking water requirements.
In the South El Monte OU, although selected remedy extraction wells have not consistently achieved
target extraction rates during the review period, remedy extraction systems are providing the required
hydraulic control and limiting the migration of COCs in groundwater at the downgradient (leading
edge) of contamination in each of the target areas. The institutional controls (governmental controls)
that are in place supplement the remedy and effectively prevent unacceptable exposure to
contaminated Site groundwater. The remedy is meeting all ARARs in the ROD, and there have been
7-4
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
no changes in ARARs affecting the protectiveness of the remedy. Although the toxicity values for
TCE became more stringent in 2011, the current MCL is within EPA's risk range and is therefore
protective of human health and the environment. Otherwise, there have been no other changes in the
toxicity factors for the COCs that were used in the previous risk assessments or the standardized risk
assessment methodology that could affect the protectiveness of the remedy.
The water purveyors operating the South El Monte OU remedy have developed preliminary plans for
installation of systems to treat the EC 1,4-dioxane to meet drinking water standards in the future, as
necessary.
EPA is actively evaluating the potential for vapor intrusion at selected facilities in the upgradient
source areas as part of its supplemental RI/FS. There is no other information that calls into question
the protectiveness of the remedy.
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
7-5
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7-6 Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
-------
8. Issues
No issues were identified that affect the protectiveness of the Richwood OU and Suburban OU
remedies.
Issue
Affects Current
Protectiveness
(Yes or No)
Affects Future
Protectiveness
(Yes or No)
South El Monte OU: Vapor intrusion was not
considered as an exposure pathway in the IROD.
Yes*
Yes*
*The Comprehensive Environmental Response, Compensation, and Liability Information System (CERCLIS)
database only accepts "Yes" or "No" entries regarding whether an issue affects current or future protectiveness.
However, this protectiveness determination has been deferred because there is not enough information to make the
determination. For the purposes of the CERCLIS database, a "defer" determination is equivalent to "yes" entry.
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
8-1
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8-2 Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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9. Recommendations and Follow-up Actions
No actions are needed to achieve or maintain the protectiveness of the Richwood OU and Suburban OU
remedies.
Issue
Recommendations
-------
Richwood OU
The Richwood OU has been inactive for a long time. EPA should consider partial deletion of the
Richwood OU from the NPL because RMWC no longer exists, all of the former RMWC customers are
served by SGVWC, and the remedy treatment plant was shut down in 1994.
)urba.
The Suburban OU has been inactive for a long time. EPA should consider partial deletion of the
Suburban OU from the NPL. Contaminant concentrations have remained consistently low since the 1993
ROD Amendment and there are no upgradient indications of future increases. In the unlikely event that
concentrations do start increasing, conditions would be evaluated as part of the Whittier Narrows OU
given that the SWS Bartolo Well Field is within the Whittier Narrows OU footprint.
9-2
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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10. Protectiveness Statements
fii
A protectiveness determination for the South El Monte OU (OU 5) interim remedy cannot be made
until further information is obtained. EPA is currently conducting a vapor intrusion investigation,
including soil vapor sampling and indoor air sampling at and near source facilities throughout the
South El Monte OU. It is expected that the investigation will take approximately 3 years to complete,
at which time a protectiveness determination will be made.
10.2. Richwood Oil
The interim remedy for the Richwood OU (OU 3) is protective of human health and the environment.
wrban OU
The interim remedy for the Suburban OU (OU 4) is protective of human health and the environment.
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
10-1
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10-2 Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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11. Next Review
Because there is still contamination onsite that does not allow for unrestricted use and unlimited exposure,
another FYR will be required. The next FYR will be due within 5 years of the signature date of this FYR
in 2018. However, the Whittier Narrows OU was last reviewed in 2011, so EPA plans to evaluate the
entire San Gabriel Valley Area 1 Superfund Site in 2016, including the OUs evaluated in this report, so
that all of the OUs will be on the same review schedule moving forward. Because the protectiveness
determination was deferred for the South El Monte OU interim remedy during this review, a
determination will be made at the time of the next FYR.
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
11-1
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11-2 Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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Appendix A: List of Documents Reviewed
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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Appendix A. List of Documents Reviewed
California Department of Public Health (CDPH). 2009a. Removal of Perchlorate Treatment at the San
Gabriel Treatment Plant - Golden State Water Company. May.
CDPH. 2009b. Removal of Treatment at [Monterey Park] Wells 9, 12, and 15 Treatment Plant. May.
CH2M HILL. 1983. Draft Focused Feasibility Study, San Gabriel. December.
CH2M HILL. 1988. Draft Operable Unit Feasibility Study for Suburban Water Systems Bartolo Well
Field of San Gabriel Areas 1-4. June.
CH2M HILL. 1995. Capture Zone Evaluation for Suburban Production Wells within Whittier Narrows.
October.
CH2M HILL. 1997. South El Monte OU Final Preliminary Baseline Risk Assessment. December.
CH2M HILL. 2006. Recommended SEMOUInterim Remedial Action Pumping Rates. June.
CH2M HILL. 2007. Draft Technical Memorandum, Evaluation of the Potential Impact of 1,4-Dioxane
Contamination on Proposed Remedy Wells, South El Monte Operable Unit, San Gabriel Basin,
California. September.
CH2M HILL. 2009. Evaluation of Perchlorate Concentration Trends in Groundwater, South El Monte
OU. May.
CH2M HILL. 201 la. Data Review and Remedy Performance Evaluation Technical Memorandum—
Whittier Narrows OUFive-Year Review. May.
CH2MHILL. 2011b. Whittier Narrows OU Groundwater Flow Model Update and Contaminant
Transport Simulations. June.
CH2M HILL. 2013. Draft Remedial Action Report, San Gabriel Valley Area 1 Superfund Site - South El
Monte Operable Unit
DTSC. 1994a. Letter re: Notification of Option to Shut Down Richwood Treatment Plant. January.
DTSC. 1994b. Contract 94-T0753 between DTSC and SGVWC. November.
DTSC. 1996. Memorandum Re: Status and Failures of Richwood Operable Unit. November.
DTSC. 1998a. Letter Re: Dismantling of Richwood Treatment Plant. June.
DTSC. 1998b. RMWC Treatment Plan Decommissioning Fact Sheet. November.
DTSC. 1999a. Contract 94-T1721 Between DTSC and SGVWC. March.
DTSC. 1999b. Report of AWP Activity Completion. December.
DTSC. 2010. Agreement between DTSC and EPA. Agreement Number 09-T9114. July.
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
A-1
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DTSC. 2012a. Comments on Upcoming Five Year Review of San Gabriel Valley Superfund Site Area 1,
Los Angeles County. May.
DTSC. 2012b. Comments on Compliance Well Installation and First Semi-Annual Remedial Action
Compliance Monitoring Report. June.
EPA. 1984. Superfund Record of Decision: San Gabriel/Area 1 Site, CA. May.
EPA. 1987. Record of Decision Amendment Decision Summary, San Gabriel Area 1, Initial Remedial
Measures. September.
EPA. 1988. Record of Decision for Suburban Water Systems Bartolo Well Field Operable Unit.
September.
EPA. 1992. Interim San Gabriel Basin Remedial Investigation Report, Los Angeles County, California.
July.
EPA. 1993. Record of Decision Amendment, Suburban Water Systems Bartolo Well Field Operable Unit,
Declaration. September.
EPA. 1994. Memorandum: Review of Data for Suburban Record of Decision Requirements. September.
EPA. 1995. Memorandum Re: Verification by EPA and DTSC that the Richwood Treatment Plant has
been Operational and Functional. April.
EPA. 1999. Interim Record of Decision Amendment, San Gabriel Valley Superfund Site, Whittier
Narrows Operable Unit. November 10.
EPA. 1999. Interim Record of Decision, San Gabriel Valley Superfund Site, El Monte Operable Unit.
June.
EPA. 2000. Interim Record of Decision, San Gabriel Valley Superfund Site, South El Monte Operable
Unit, Los Angeles County, CA. September.
EPA. 2002. EPA Guidance for Quality Assurance Project Plans, EPA/QA/G-5. EPA/240/R-02/009.
December.
EPA. 2003. Letter Re: Response to Inquiry Regarding Region 9's Involvement at Suburban Operable
Unit. June.
EPA. 2004. Supplemental Risk Assessment, South El Monte Operable Unit.
EPA. 2005. Explanation of Significant Differences to the 2000 Interim Record of Decision, South El
Monte Operable Unit, San Gabriel Valley Superfund Sites, Area 1. November.
EPA. 2006. Work Plan and Addendum to Cooperative Agreement Between EPA and the San Gabriel
Basin Water Quality Authority (SGBWQA). October.
EPA. 2008a. Superfund Support Agency Cooperative Agreement (V-96923701-0), South El Monte OU.
August.
A-2
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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EPA. 2008b. A Systematic Approach for Evaluation of Capture Zones at Pump and Treat Systems, EPA
Office of Research and Development, Ground Water and Ecosystems Restoration Division, National Risk
Management Research Laboratory. USEPA/600/R-08/003. January. Available on the Internet at:
(http://www. epa. gov/ada/download/reports/600R08003/600R08003.pdf).
EPA. 2009a. 2009 Edition of the Drinking Water Standards and Health Advisories. EPA 822-R-09-011.
EPA. 2011. Second Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site, Whittier
Narrows Operable Unit. September.
EPA. 2012a. Site Inspection for San Gabriel Valley Area 1 Superfund Site, South El Monte Operable
Unit. June.
EPA. 2012b. Response to DTSC Letter of June 28, 2012, Compliance Well Installation & First Semi-
Annual Remedial Action Compliance Monitoring Report for San Gabriel Valley Area 1 Superfund Site,
South El Monte OU, Los Angeles County. August.
EPA. 2012c. Response to DTSC Letter of May 25, 2012 on Upcoming Five Year Review of San Gabriel
Valley Superfund Site, Area 1, Los Angeles County. December.
EPA. 2013a. OSWER Final Guidance for Assessing and Mitigating the Vapor Intrusion Pathway from
Subsurface Sources to Indoor Air (External Review Draft). April 11.
EPA. 2013b. Integrated Risk Information System (IRIS) Database.
Online: http: //www.epa.gov/1 RIS/
Geosyntec Consultants (Geosyntec). 2009. General Monitoring Plan, Eastern Shallow and Southern
Deep Portions of the El Monte Operable Unit. January 30.
Geosystem Consultants, Inc. (Geosystem). 1999. Feasibility Study Report, Interim Remedial
Investigation/Feasibility Study, South El Monte Operable Unit, San Gabriel Basin, Los Angeles County,
California. April.
Geosystem. 1997. Technical Memorandum, Site Characterization and Alternatives Development, Interim
Remedial Investigation/Feasibility Study, South El Monte Operable Unit, San Gabriel Basin, Los Angeles
County, California. March.
Geosystem. 1998. Remedial Investigation Report, Interim Remedial Investigation/Feasibility Study, South
El Monte Operable Unit, San Gabriel Basin, Los Angeles County, California. August.
ITSI Gilbane Company (ITS I). 2011a. Final Sampling and Analysis Plan, Remedial Action Compliance
Monitoring, San Gabriel Valley Area 1 Superfund Site, South El Monte Operable Unit, San Gabriel
Basin, Los Angeles County, California. February.
ITSI. 201 lb. Final Sampling and Analysis Plan, Supplemental Remedial Investigation/Feasibility Study,
San Gabriel Valley Area 1 Superfund Site, South El Monte OU. March.
ITSI. 2012a. Compliance Well Installation and First Semi-Annual Remedial Action Compliance
Monitoring Report, San Gabriel Valley Area 1 Superfund Site, South El Monte Operable Unit. March.
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
A-3
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ITSI. 2012b. Technical Memorandum: Third Modification to Sampling and Analysis Plan, Supplemental
Remedial Investigation/Feasibility Study, San Gabriel Valley Area 1 Superfund Site, South El Monte,
Operable Unit. August.
ITSI. 2013. Remedial Action 2012 Compliance Monitoring Report, San Gabriel Valley Superfund Site,
South El Monte Operable Unit. April.
Main San Gabriel Basin Watermaster (Watermaster). 2012. Draft Five-Year Water Quality and Supply
Plan (2012-13 - 2016-17). November.
McCormick, Kidman, & Behrens, LLP (McCormick). 1999. Agreement to Purchase and Sale of Assets:
RMWC to SGVWC. March.
San Gabriel Basin Water Quality Authority (WQA). 2010. Revised Performance Report (September 1,
2008 through June 30, 2010) Superfund Support Agency Cooperative Agreement (V-96923701-0) South
El Monte OU. October.
WQA. 2010. Summary Schedule for EPA Request #2, Schedules of Operations and Maintenance Costs
Not Funded by Other Sources. Agreement #¥-96923701-0. September.
WQA. 201 la. Summary Schedule for EPA Request #3 - Revision 2, Schedules of Operations and
Maintenance Costs Not Funded by Other Sources. Agreement #¥-96923701-0. February.
WQA. 201 lb. Summary Schedule for EPA Request #4 - Revision 1, Schedules of Operations and
Maintenance Costs Not Funded by Other Sources. Agreement #¥-96923701-0. March.
WQA. 201 lc. Summary Schedule for EPA Request #5 - Revision 1, Schedules of Operations and
Maintenance Costs Not Funded by Other Sources. Agreement #¥-96923701-0. July.
WQA. 201 Id. Revised Annual Performance Report (July 1, 2010 through June 30, 2011), Superfund
Support Agency Cooperative Agreement (V-96923701-0), South El Monte OU. September.
WQA. 201 le. Summary Schedule for EPA Request #6- Revision 1, Schedules of Operations and
Maintenance Costs Not Funded by Other Sources. Agreement #¥-96923701-0. November.
WQA. 201 If. Summary Schedule for EPA Request # 7 - Revision 1, Schedules of Operations and
Maintenance Costs Not Funded by Other Sources. Agreement #¥-96923701-0. November.
WQA. 2012a. Summary Schedule for EPA Request #8 - Revision 2, Schedules of Operations and
Maintenance Costs Not Funded by Other Sources. Agreement #¥-96923701-3. March.
WQA. 2012b. Revised Annual Performance Report (July 1, 2011 through June 30, 2012), Superfund
Support Agency Cooperative Agreement (V-96923701-0), South El Monte OU. July.
WQA. 2012c. Summary Schedule for EPA Request #9 - Revision 1, Schedules of Operations and
Maintenance Costs Not Funded by Other Sources. Agreement #¥-96923701-3. July.
WQA. 2012d. Summary Schedule for EPA Request #10 - Revision 2, Schedules of Operations and
Maintenance Costs Not Funded by Other Sources. Agreement #¥-96923701-3. July.
WQA. 2012e. Summary Schedule for EPA Request #11 - Revision 1, Schedules of Operations and
Maintenance Costs Not Funded by Other Sources. Agreement #¥-96923701-3. September.
A-4
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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WQA. 2012f. Quarterly Report (Reporting Period of July-September 2012), Superfund Support Agency
Cooperative Agreement (V-96923701), South El Monte OU. October.
WQA. 2012g. Summary Schedule for EPA Request #12 - Revision 1, Schedules of Operations and
Maintenance Costs Not Funded by Other Sources. Agreement #¥-96923701-3.
WQA. 2013a. Summary Schedule for EPA Request #13 - Revision 1, Schedules of Operations and
Maintenance Costs Not Funded by Other Sources. Agreement #¥-96923701-3. May.
WQA. 2013b. Summary Schedule for EPA Request #14, Schedules of Operations and Maintenance Costs
Not Funded by Other Sources. Agreement #¥-96923701-3. May.
WQA. 2013c. Quarterly Report (Reporting Period of October-December 2012), Superfund Support
Agency Cooperative Agreement (V-96923701), South El Monte OU. October.
WQA. 2013d. Quarterly Report (Reporting Period of January-March 2013), Superfund Support Agency
Cooperative Agreement (V-96923701), South El Monte OU. October.
San Gabriel Valley Water Company (SGVWC). 1995. Letter from SGVWC to RMWC Re: SG¥WC
willing to Install New Distribution System and Take Over RMWC. April.
SGVWC. 1999. Letter Re: Completion of Distribution System Described in Contract 91-T1721.
December.
Smucker, Stanford Ph. D. 1992. Suburban Water Systems /Bartolo Well Field Operable Unit Screening
Risk Assessment. July.
Suburban Water Systems. 2013. Plant 201 - Location of Wells and Pipelines. March.
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
A-5
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A-6 Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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Appendix B: Public Notices
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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^prct
PUBLIC NOTICE
THE UNITED STATES ENVIRONMENTAL PROTECTION AGENCY BEGINS
FIRST FIVE-YEAR REVIEW OF CLEANUP AT THE SAN GABRIEL VALLEY
AREA 1 SUPERFUND SITE
The U.S. Environmental Protection Agency (EPA) has begun its first five-year
review of cleanup actions at the San Gabriel Valley Area 1 Superfund Site (Site)
located in Los Angeles County. Because the Site is large, it includes multiple
cleanup actions or operable units (OUs), including the South El Monte OU, the
Whittier Narrows OU, the Richwood OU, the Suburban OU, and the El Monte OU.
The focus of this five-year review will be the South El Monte OU, which has an
active groundwater remedy that EPA began funding in 2008, and the Richwood and
Suburban OUs, which have not previously been evaluated. Five-year reviews for
the Whittier Narrows OU were completed in 2006 and 2011, and the remedy at the
El Monte OU is still under construction. All of the cleanup actions at the Site address
contaminated groundwater.
THE REVIEW PROCESS
The primary purpose of a five-year review is to determine whether a site remedy
remains protective of human health and the environment. EPA generally conducts
five-year reviews when hazardous substances remain in the groundwater above
risk-based levels that prevent unrestricted use and exposure. As part of the review,
EPA will be looking at how well the remedy is achieving EPA's cleanup goals,
changes in scientific knowledge about site contaminants, changes in exposure
pathways, and changes in regulations.
COMMUNITY INVOLVEMENT
If you have any concerns about the San Gabriel Valley Area 1 Site, and particularly
if you have direct knowledge regarding the operation and maintenance of the
remedy, then EPA would like to talk with you. When completed, a copy of the five-
year review report will be placed in the information repository and will be available
on-line at EPA's website listed below.
SITE HISTORY
The San Gabriel Valley Area 1 site is an area of contaminated groundwater over 4
miles long and VA miles wide located in the San Gabriel Valley. The Site is one of four
groundwater cleanup sites in the San Gabriel Valley being addressed under EPA's
Superfund cleanup program since 1984. The groundwater contamination is the result
of decades of poor chemical handling and disposal practices by hundreds of industrial
facilities. The primary chemical contaminants in the Site's groundwater are volatile
organic compounds including tetrachloroethene (PCE) and trichloroethene (TOE),
which are both industrial solvents. EPA has multiple ongoing remedies throughout
Area 1, including extracting and treating contaminated groundwater.
FOR MORE INFORMATION
Please visit EPA's website for the San Gabriel Valley Area 1 Site:
www.epa.gov/region09/SouthEIMonte
Information Repositories:
Rosemead Public Library Superfund Records Center
880 Valley Blvd. 75 Hawthorne St.
Rosemead, CA91770 San Francisco, CA94105
(626) 573-5220 (415) 947-8000
Hours: Mon-Fri 8am-5pm
West Covina Public Library
1601 West Covina Parkway
West Covina, CA91790-2786
(626) 962-3541
Contact Information:
Alejandro Diaz Bella Dizon
Community Involvement Coordinator Project Manager,
75 Hawthorne Street (SFD-6-3) Whittier Narrows OU & El Monte OU
San Francisco, CA94105 75 Hawthorne Street (SFD-7-3)
(800) 231 -3075 or (415) 972-3242 San Francisco, CA 94105
diaz.alejandro@epa.gov (415)-972-3190
dizon.bella@epa.gov
Rachelle Thompson
Project Manager, South El Monte OU
75 Hawthorne Street (SFD-7-3)
San Francisco, CA94105
(415)-972-3962
thompson.rachelle@epa.gov CNS#2417326
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5RJND RECORDS CTR
2271279
AVISO PUBLICO
LA AGENCIA DE PROTECCfQN AMBIENTAL OE LOS ESTADOS UNIDOS
COMIENZA LA PRIMERA REVISON DE CINCO ANOS SOBRp LA
LIMPIE2A EN EL SITIO SUPERFUND SAN GABRIEL VALLEY AREA 1
La Agenda de Profeccidn Ambientaf de los Estados Unidos (EPA, por sus siglas
en ingles) ha comenzaco au primera revision de cinco Afios sobre activWades
de Iimpieza en el sitio Superfund San Gabriel Valley Area 1 ubicado en el
Condado de Los Angeles, El sitio es muy grande y por esa raz6n incluye a
varias acetones de iimpieza o unidades operables fUU OO.). incluyendo a la
UO South EI Monte. UO Whittier Narrows, UO Richwood, UO Suburban y la
UO EI Monte. El enfoque de esta revisi6n de cinco afios sera la UO South
El Monte, donde se encuentra un remedio activo del agua subterrdnea que !a
EPA comenzo a financfar en 2008 y las UU.OO, da Richwood y Suburban, que
no habian sido evaEuadas previamenta. La revision de cinco afios para la UO
Whittier Narrows fue compfatada en 2006 y 2011 y el remedio por la UO Ei
Monte esta bajo construcc»6n. Todas las acciones de JSmpieza del sitto abordan
agua subterranea contaminada.
EL PROCESSO DE REVISION
El propositc principal de la revtsidn de cinco aftos es determiner si un remedio
continua protegiendo la salud humana y e! medio ambienle. En general, fa
EPA hace revisiones de etneo afios cuando sustancias toxicas permanecen
en el agua subterranea sobre niveies basados en riesgo que prohfben su
uso y exposici6n sin restrtcciones. Como parte de la revision, la EPA estard
viendo como el remedio esta aicanzando los obj'etivos de iimpieza, cambios en
conocimiento cieniifico sobre los contaminantes de! sitio, cambios en vias de
exposicidn y cambios en reglamentos,
PARTICIPACI6N COMUNtTARIA
Si usted tiene preocupaciones ,sobre si sitio San GabrieJ Valley Area 1, y
especiaimente si usted tiene conocimiento dtrecio sobre la operacion y
mantenimiento de) remedio, entonces la EPA gustaria habiar con usted.
Cuando se complete, una copla dei informe de la revisi6n de cinco afios estara
disponibie en el deposrto de informacibn y tambten sera dispcnible en internet aI
sitio de la EPA a continuation.
HISTORJA DEL SITIO
EJ sitio San Gabriel Valley Area 1 es un area de agua subterranea contaminada
m4s de 4 mliias de iargo y V/s millas de ancbo ubicado en el vaiie de San
Gabriel. El Sitio es uno de cuatro sitios de iimpieza dei agua subterranea
en eJ vaiie de San Gabriel abordado bajo el programs Superfund de ia EPA
desde 1984. La contaminaciAn del agua subterranea es resuitado de dicadas
de pobre manejo y eifminacidn de contaminantes de cientos de instataciones
industriafes. Los qufmicos principales de contaminaci6n en ei agua subterranea
del sitto son productos organicos vol&iiles incluyendo a tetraclcroetileno {PCE) y
tricloroetiieno (TCE), que ambos son solventes Industriaies de Iimpieza, La EPA
tiene varios remedies actlvos en ei £rea 1, Incluyendo ia extraccidn y tratamiento
dei agua subterranea contaminada.
PARA MAS INFORMACldN
For favor visile sitio de internet de ia EPA para ei sitio San Gabriel Valley Area 1:
www.epa.gov/ragion09fSouthEIMonte
Dopositos Oo Informaclcn:
Bibliotsca Rosemead
880 Valley Blvd.
Rosemead, CA 91770
(828)573-5220
Bibliotsca West Covins
1601 West Covina Parkway
West Covina, CA 91790-2786
(826) 882-3541
Informacion de Contaeto;
Alejandro Diaz (hispanohablanta)
Coordlrtador de Participacifin Comunitaria
75 Hawthorns Street (SFD-6-3)
San Francisco, CA94105
(800) 231-3075 or (415) 972-3242
diaz.atejandro@epa.gov
Rachalte Thompson
Gerente del Proyeoto, UO South El Monte
75 Hawthorne Street (SFD-7-3)
San Francisco, CA 94105
(415)-972-3i62
ttiompson.rarfielle@epa.gov
109-10MS97J CNS#2417343
7 A j SABAPO S mci?MP»r nF ?ni? u aDj0l6n
¦ i i I I, -i . ¦ ¦ j ^
Centre de Registros Superfund
75 Hawthorne St,
San Francisco. CA 94105
(415)947-8000
Moras: lun-vier 8am-5pm
Bella Dizon
Gerente del Proyecto,
UO Milttiar Narrows y EI Monte
75 Hawthorne Street (SFD-7-3)
San Francisco, CA 94105
(415)-972-3190
ai2an.bella@epa.gov
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Appendix C: Site Inspection Checklists
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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Appendix C: Site Inspection Checklists
The following Site Inspection Checklists are provided in this appendix:
• City of Monterey Park Well 5 Treatment Facility
• City of Monterey Park Wells 12 and 15 Treatment Facility
• Golden State Water Company San Gabriel Wells 1 and 2 Treatment Facility
• San Gabriel Valley Water Company Plant Treatment Facility
• Former Richwood Mutual Water Company
• Suburban Water Systems Bartolo Well Field
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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San Gabriel Valley Area 1 Superfund Site
Los Angeles County, California
Five-Year Review Site Inspection Checklist
SEMOU - MONTEREY PARK WELL 5 FACILITY
1. SITE INFORMATION
Site Name: San Gabriel Valley Area 1 Superfund Site
EPA ID: CAD980677355
City/State: Rosemead, CA
Date of Inspection: March 20, 2013
Agency Completing 5 Year Review: USEPA
Weather/temperature: Hazy, Upper 60s
Remedy Includes: (Check all that apply)
O Landfill cover/containment
O Access controls
~ Institutional controls
H Groundwater pump and treatment
O Surface water collection and treatment
Attachments: M Inspection team roster attached
O Site map attached
II. INTERVIEWS (Check all that apply)
1. Monterey Park Management
Contact: Chris Arriola
Title: Water Utilities Manager
Date: 2/21/13
Interviewed: Q at site Q at office
^ by phone Phone Number:
Problems, suaaestions: l~1 Additional report attached (if additional space required).
See Interview Form in Appendix C.
2. Local regulatory authorities and response agencies (i.e., State and Tribal offices, emergency response office, police
department, office of public health or environmental health, zoning office, recorder of deeds, or other city and county
offices, etc.): None interviewed.
3. Other interviews (optional) ON/A ^ Additional report attached (See Interview Forms in Appendix C).
Water Purveyors- Golden State Water Company, San Gabriel Valley Water Company, Suburban Water Systems, Rurban
Mutual, Hemlock Mutual
Water Management Agencies- Main San Gabriel Basin Watermaster, San Gabriel Basin Water Quality Authority
III. ONSITE DOCUMENTS & RECORDS VERIFIED (Check all that apply)
1. O&M Documents
H O&M Manuals
S As-Built Drawings
M Maintenance Logs
Remarks:
There is an on-site logbook used to track routine operational observations and daily readings. Separate from the inspection,
Monterey Park has provided the latest version of their operations, maintenance and monitoring plan (OMMP). The as-built
drawings are kept in the document storage room at the Delta Plant. Maintenance logs are also kept at the Delta Plant.
S Readily available ^ Up to date Q N/A
S Readily available S Up to date ~ N/A
M Readily available M Up to date ~ N/A
SGArea1_FYR_SiteInspectionChecklist_MPWell5_dt.doc Page 1 of 8
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Monterey Park Well 5, Site Inspection Checklist
2.
Health and Safety Plan Documents
M Site-Specific Health and Safety Plan M Readily available M Up to date ~ N/A
H Contingency plan/emergency response plan H Readily available H Up to date ~ N/A
Remarks: Monterey Park has on-site, site-specific plans to address each treatment facility, includina Well 5. In addition,
they have an emergency response plan for the overall water system. These plans are reviewed annually and updated as
necessary.
3.
O&M and OSHA Training Records H Readily available H Up to date ON/A
Remarks: Monterey Park operators are HAZWOPER trained and aet annual 8-hr refreshers. Documentation is kept in
each employees personnel file. CDPH requires that the system operators be T-2 certified (at a minimum). All Monterey
Park's operations staff have at least a T-2 certification. Training and certification information is provided to CDPH
annually. Certificates are on the wall at the Delta Plant and the operators carry a card documenting their certification.
4.
Permits and Service Agreements
l~l Air discharge permit l~l Readily available O-Uptodate E3 N/A
E3 Effluent discharge ^ Readily available El Up to date ON/A
^ Waste disposal, POTW O Readily available ~ Up to date O N/A
O Other permits O-Readily available O Up to date ^ N/A
Remarks: Effluent discharge is covered by the CDPH permit, which was updated in 2011 when the perchlorate treatment
was removed. The City has an NPDES permit to cover discharge of backwash water to the wash. Neither permit was
reviewed as part of the inspection.
5.
Groundwater Monitoring Records ^ Readily available El Up to date O N/A
Remarks: Groundwater monitoring for the South El Monte OU remedy is conducted by EPA. Monterey Park is not
involved.
6.
Discharge Compliance Records O Readily available ^ Up to date O N/A
Remarks: All of the CDPH-permit reauired monitoring, including the wells, LGAC vessels and plant effluent, is conducted
by Monterey Park and the analyses are done in accordance with the CDPH permit. The lab submits the data directly to
CDPH. In addition, the City submits monthly reports and an annual report to CDPH. There is still an active perchlorate
blending plan for Well 5, although they have reduced the monitoring frequency.
7.
Daily Access/Security Logs O Readily available ^ Up to date ON/A
Remarks: The City performs daily checks when Well 5 is operating (for most of the year, the well is off for several days a
week). The daily access/checks are documented in the on-site logbook kept at Well 5.
IV. O&M Costs MApplicable ON/A
1.
O&M Organization
O State in-house O Contractor for State
O PRP in-house O Contractor for PRP
^ Other: The City of Monterey Park operates the facility.
2.
O&M Cost Records-
^ Readily available ^ Up to date O Funding mechanism/agreement in place
Remarks: Not reviewed as part of the Site Inspection, but EPA reviews O&M costs on a auarterlv basis
3.
Unanticipated or Unusually High O&M Costs During Review Period ^ N/A
Describe costs and reasons: Nothing of note for the last several years.
V. ACCESS AND INSTITUTIONAL CONTROLSApplicable ~ N/A
SGArea1_FYR_SiteInspectionChecklist_MPWell5_dt.doc
Page 2 of 8
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Monterey Park Well 5, Site Inspection Checklist
1.
Fencing
1.
Fencing damaged Q Location shown on site map ^ Gates secured
Remarks: The facility is fullv enclosed bv an intact fence.
ON/A
2.
Other Access Restrictions
1.
Signs and other security measures ~ Location shown on site map
Remarks: There are no specific warnina sians on the aate or fence.
ON/A
3.
Institutional Controls
1. I mplementation and enforcement
Site conditions imply ICs not properly implemented:
OYes
O
No
M
N/A
Site conditions imply ICs not being fully enforced:
OYes
O
No
M
N/A
Reporting is up-to-date:
OYes
O
No
B
N/A
Reports are verified by the lead agency:
OYes
~
No
M
N/A
Specific requirements in deed or decision documents have been
met: O Yes
O
No
M
N/A
Violations have been reported:
OYes
O
No
M
N/A
2. Adequacy Q ICs are adequate Q ICs are inadequate ^ N/A
Remarks:
4. General
1. Vandalism/trespassing ~ Location shown on site map ^ No vandalism evident
Remarks: The City has not had any issues with vandalism or trespassing. Well 5 is in a fairly isolated area.
2. Land use changes onsite ~ N/A
Remarks: None
3. Land use changes offsite Q N/A
Remarks: None, although the surrounding nursery operations have been reduced. The City has had discussions with
GSWC about selling them a portion of the surrounding property so they can construct a storage reservoir.
VI. GENERAL SITE CONDITIONS
1. Roads Q Applicable ^N/A
1. Roads damaged ~ Location shown on site map ~ Roads adequate O N/A
Remarks:
2. Other Site Conditions
Remarks: Nothing of note.
IX. GROUNDWATER/SURFACE WATER REMEDIES
^Applicable
ON/A
1. Groundwater Extraction Wells, Pumps, and Pipelines
O Applicable
ON/A
SGArea1_FYR_SiteInspectionChecklist_MPWell5_dt.doc
Page 3 of 8
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Monterey Park Well 5, Site Inspection Checklist
1.
Pumps, Wellhead Plumbing, and Electrical ~ N/A
^ All required wells located ^ Good condition ~ Needs 0& M
Remarks:
2.
Extraction System Pipelines, Valves, Valve Boxes, and Other Appurtenances ~ N/A
^ System located ^ Good condition ~ Needs 0& M
Remarks:
3.
Spare Parts and Equipment ^ N/A
~ Readily available ~ Good condition
~ Requires Upgrade ~ Needs to be provided
Remarks:
2.
Treatment System Applicable Q N/A
1.
Treatment Train (Check components that apply)
~ Metals removal ~ Oil/water separation ~ Bioremediation
~ Air stripping ^ Carbon adsorbers ~ Filters (list type):
~ Additive (list type, e.g., chelation agent, flocculent)
Q Others (list):
^ Good condition ~ Needs O&M
^ Sampling ports properly marked and functional
~ Sampling/maintenance log displayed and up to date
^ Equipment properly identified
~ Quantity of groundwater treated annually (list volume):
Remarks: LGAC vessel pipina and valve trees need to be painted. The vessels themselves are fine. Sodium
hypochlorite is added prior to the water leaving the Well 5 facility
2.
Electrical Enclosures and Panels (properly rated and functional) ~ N/A
^ Good condition ~ Needs 0& M
Remarks: All operational readinas/data are recorded bv the SCADA system and transmitted back to the Delta Plant.
3.
Tanks, Vaults, Storage Vessels ^ N/A
~ Good condition ~ Proper secondary containment ~ Needs O&M
Remarks:
4.
Discharge Structure and Appurtenances ~ N/A
^ Good condition ~ Needs 0& M
Remarks: The extraction wells pump the water throuah the LGAC vessels at system pressure (-135 psi) and directly into
the distribution system carrying water from the Delta Plant back to the City. There are no booster pumps.
5.
Treatment Building(s) ON/A
^ Good condition (esp. roof and doorways) Q Needs Repair
^ Chemicals and equipment properly stored (Only chemical is the sodium hypochlorite.)
Remarks: The small buildina houses the sodium hypochlorite storaae and all of the electrical eauipment and controls.
6.
Monitoring Wells (pump and treatment remedy) Q N/A
^ All required wells located ^ Properly secured/locked ^ Functioning^ Routinely sampled
^ Good condition ~ Needs O&M
Remarks: Monitorina wells are not on-site and were not included in the inspection. However, EPA routinely samples all
of the required monitoring wells and all are functioning and in good condition.
3.
Long Term Monitoring Applicable Q N/A
SGArea1_FYR_SiteInspectionChecklist_MPWell5_dt.doc Page 4 of 8
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Monterey Park Well 5, Site Inspection Checklist
1. Monitoring Wells- See preceding entry regarding the status of monitoring wells associated with the remedy.
X. OTHER REMEDIES ~ Applicable MN/A
If there are remedies applied at the site which are not covered above, attach an inspection sheet describing the physical
nature and condition of any facility associated with the remedy.
XI. OVERALL OBSERVATIONS
1. Implementation of the Remedy
Describe issues and observations relating to whether the remedy is effective and functioning as designed. Begin with a brief
statement of what the remedy is to accomplish (i.e., to contain contaminant plume, minimize infiltration and gas emission,
etc.).
Nothing significant noted, but see the interview form for Chris Arriola/Monterey Park for additional detail. The City does not
have any problems meeting the Well 5 minimum target pumping rates for containment.
2. Adequacy of O&M
Describe issues and observations related to the implementation and scope of O&M procedures. In particular, discuss their
relationship to the current and long-term protectiveness of the remedy.
Nothing significant.
3. Early Indicators of Potential Remedy Failure
Describe issues and observations such as unexpected changes in the cost or scope of O&M or a high frequency of
unscheduled repairs that suggest that the protectiveness of the remedy may be compromised in the future.
Nothing significant.
4. Opportunities for Optimization
Describe possible opportunities for optimization in monitoring tasks or the operation of the remedy.
The City anticipates ultimately bringing Well 6 back on-line to provide more operational flexibility. This would occur after the
City has constructed the new, centralized treatment facility they are currently planning. The new facility would be designed to
treat the water from all of their active wells and include UV/Ox treatment to address 1,4-dioxane. Well 5 (and 6 once re-
activated) would be piped back to the Delta Plant and the Well 5 LGAC system would be eliminated
SGArea1_FYR_SiteInspectionChecklist_MPWell5_dt.doc
Page 5 of 8
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Monterey Park Well 5, Site Inspection Checklist
Inspection Team Roster
Name
Organization
Title
Rachelle Thompson
U.S. EPA Region 9
Remedial Project Manager
David Towell
CH2M HILL
EPA Contractor
Chris Arriola
City of Monterey Park
Water Utilities Manager
Tom Ruggeri
City of Monterey Park
Sr. Water Production Specialist
6
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Monterey Park Well 5, Site Inspection Checklist
Photo 1: MP Well 5 Wellhead
Photo 2: LGAC Vessels
7
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San Gabriel Valley Area 1 Superfund Site
Five- Year Review Report, Monterey Park Well 5, Site Inspection Checklist
Photo 3: Discharge Piping and Chlorine Injection
Photo 4: Chlorine Storage
8
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San Gabriel Valley Area 1 Superfund Site
Los Angeles County, California
Five-Year Review Site Inspection Checklist
SEMOU - MONTEREY PARK WELL 12/15 FACILITY
I. SITE INFORMATION
Site Name: San Gabriel Valley Area 1 Superfund Site
EPA ID: CAD980677355
City/State: Rosemead, CA
Date of Inspection: March 20, 2013
Agency Completing 5 Year Review: USEPA
Weather/temperature: Hazy, Upper 60s
Remedy Includes: (Check all that apply)
O Landfill cover/containment
O Access controls
~ Institutional controls
H Groundwater pump and treatment
O Surface water collection and treatment
Attachments: M Inspection team roster attached ~ Site map attached
II. INTERVIEWS (Check all that apply)
1. Monterey Park Management
Contact: Chris Arriola
Title: Water Utilities Manager
Date: 2/21/13
Interviewed: ~ at site Ogt office ^ by phone Phone Number:
Problems, suggestions: ~ Additional report attached (if additional space required).
See Interview Form in Appendix C.
2. Local regulatory authorities and response agencies (i.e., State and Tribal offices, emergency response office, police
department, office of public health or environmental health, zoning office, recorder of deeds, or other city and county
offices, etc.): None interviewed.
3. Other interviews (optional) ON/A ^ Additional report attached (See Interview Forms in Appendix C).
Water Purveyors- Golden State Water Company, San Gabriel Valley Water Company, Suburban Water Systems, Rurban
Mutual, Hemlock Mutual
Water Management Agencies- Main San Gabriel Basin Watermaster, San Gabriel Basin Water Quality Authority
III. ONSITE DOCUMENTS & RECORDS VERIFIED (Check all that apply)
1. O&M Documents
S O&M Manuals S Readily available S Up to date ~ N/A
M As-Built Drawings M Readily available M Up to date ON/A
JSL Maintenance Logs H Readily available H Up to date O N/A
Remarks: There is an on-site logbook (at both the Well 12 facility and at Well 15) that is used to track routine operational
observations and daily readings. Separate from the inspection, Monterey Park has provided the latest version of their
operations, maintenance and monitoring plan (OMMP). The as-built drawings are kept in the document storage room at
the Delta Plant. Maintenance logs are also kept at the Delta Plant.
SGArea1_FYR_SiteInspectionChecklist_MPWell12_15_dt.doc Page 1 of 11
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Monterey Park Well 12/15 Site Inspection Checklist
2.
Health and Safety Plan Documents
M Site-Specific Health and Safety Plan M Readily available M Up to date ~ N/A
H Contingency plan/emergency response plan H Readily available H Up to date ~ N/A
Remarks: Monterev Park has on-site, site-specific plans to address each treatment facility, includina Well 12 and the
Delta Plant. In addition, they have an emergency response plan for the overall water system. These plans are reviewed
annually and updated as necessary.
3.
O&M and OSHA Training Records H Readily available M Up to date ON/A
Remarks: Monterev Park operators are HAZWOPER trained and aet annual 8-hr refreshers. Documentation is kept in
each employees personnel file. CDPH requires that the system operators be T-2 certified (at a minimum). All Monterey
Park's operations staff have at least a T-2 certification. Training and certification information is provided to CDPH
annually. Certificates are on the wall at the Delta Plant and the operators carry a card documenting their certification
4.
Permits and Service Agreements
E3 Air discharge permit E3 Readily available ^JJptodate l~l N/A
E3 Effluent discharge ^ Readily available El Up to date QN/A
^ Waste disposal, POTW ~ Readily available ~ Up to date ~ N/A
^ Other permits JJ_Readily available ~ Up to date ~ N/A
Remarks: The Citv has an AQMD permit for the Well 12 air stripper. The permit is updated annually and a copy is at
Well 12. The City also has a Hazardous Materials Permit from Los Angeles County Fire Department for the Well 12
facility because of the acid. Effluent discharge is covered by the CDPH permit, which was last updated in 2006. The City
has an NPDES permit to cover discharge of backwash water from the LGAC vessels. None of the permits were directly
reviewed as part of the inspection.
5.
Groundwater Monitoring Records ^ Readily available El Up to date ~ N/A
Remarks: Groundwater monitoring for the South El Monte OU remedy is conducted by EPA. The City is not involved.
6.
Discharge Compliance Records ^ Readily available ^ Up to date Q N/A
Remarks: All of the CDPH-permit reauired monitoring, including the wells, air stripper, LGAC vessels and plant effluent, is
conducted by Monterey Park and the analyses are done in accordance with the CDPH permit. The lab submits the data
directly to CDPH. In addition, the City submits monthly reports and an annual report to CDPH. The City does not have
specific reporting requirements associated with the AQMD permit. The effluent is sampled quarterly and the carbon is
changed out every three years unless break through occurs sooner.
7.
Daily Access/Security Logs ^ Readily available ^ Up to date ON/A
Remarks: The Citv performs daily checks when Wells 12/15 are operating. The daily access/checks are documented in
the on-site logbook kept at Well 12 and at Well 15.
IV. O&M Costs ^Applicable ON/A
1. O&M Organization
Q State in-house Q Contractor for State
~ PRP in-house ~ Contractor for PRP
M Other: City of Monterey Park operates the facility
2. O&M Cost Records-
S Readily available ^ Up to date ^ Funding mechanism/agreement in place
Remarks: Not reviewed as part of the Site Inspection, but EPA reviews O&M costs on a quarterly basis
3. Unanticipated or Unusually High O&M Costs During Review Period Q N/A
Describe costs and reasons: Nothing significant. The City had to change the air stripping packing media a couple years
ago and the initial replacement media didn't work. The Well 15 pump had to be replaced because of excessive vibration.
V. ACCESS AND INSTITUTIONAL CONTROLSJS1 Applicable ~ N/A
SGArea1_FYR_SiteInspectionChecklist_MPWell12_15_dt.doc Page 2 of 11
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Monterey Park Well 12/15 Site Inspection Checklist
1. Fencing
1. Fencing damaged Q Location shown on site map ~ Gates secured Q N/A
Remarks: The Well 12 facility is fully enclosed by an intact fence, although the southeast corner of the Well 12 facility
has small section with a shorter 5-foot tall fence. Well 15 is also fully fenced with a secured gate. The Delta Plant is fully
fenced with automatic gates. However, the fence on the west side of the facility is not in as good of shape.
2. Other Access Restrictions
1. Signs and other security measures Q Location shown on site map Q N/A
Remarks: There are no specific warning signs on the gates or fences other than a standard chemical hazard warning
sign at Well 12.
3. Institutional Controls
1. I mplementation and enforcement
Site conditions imply ICs not properly implemented:
~ Yes
~
No
~
N/A
Site conditions imply ICs not being fully enforced:
~ Yes
~
No
M
N/A
Reporting is up-to-date:
~ Yes
~
No
M
N/A
Reports are verified by the lead agency:
~ Yes
~
No
~
N/A
Specific requirements in deed or decision documents have been
met: ~ Yes
~
No
~
N/A
Violations have been reported:
~ Yes
~
No
M
N/A
2. Adequacy ~ ICs are adequate ~ ICs are inadequate ~ N/A
Remarks:
4. General
1. Vandalism/trespassing ~ Location shown on site map ~ No vandalism evident
Remarks: The City has periodic trespassing and tagging at the Well 12 facility, but no significant vandalism. There have
not been any issues at Well 15. The Delta Plant previously had some issues trespassing, but not vandalism. The City
now has perimeter alarms and cameras at the Delta Plant that have curbed trespassing.
2. Land use changes onsite ~ N/A
Remarks: None.
3. Land use changes offsite ~ N/A
Remarks: None.
VI. GENERAL SITE CONDITIONS
1. Roads ~ Applicable ~ N/A
1. Roads damaged Q Location shown on site map Q Roads adequate ~ N/A
Remarks:
2. Other Site Conditions
Remarks: Nothing of note.
IX. GROUNDWATER/SURFACE WATER REMEDIES
~ Applicable
~ N/A
1. Groundwater Extraction Wells, Pumps, and Pipelines
~ Applicable
~ N/A
SGArea1_FYR_SiteInspectionChecklist_MPWell12_15_dt.doc Page 3 of 11
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Monterey Park Well 12/15 Site Inspection Checklist
1.
Pumps, Wellhead Plumbing, and Electrical ~ N/A
^ All required wells located ^ Good condition ~ Needs 0& M
Remarks: The Well 15 pump was replaced in 2011 and there have not been anv issues since.
2.
Extraction System Pipelines, Valves, Valve Boxes, and Other Appurtenances ~ N/A
^ System located ^ Good condition ~ Needs 0& M
Remarks:
3.
Spare Parts and Equipment ^ N/A
Remarks:
3.
Treatment System ^Applicable QN/A
1.
Treatment Train (Check components that apply)
Q Metals removal Q Oil/water separation Q Bioremediation
^ Air stripping ^ Carbon adsorbers (6 vessels) ^ Filters: Pre-filters- 2 vessels; 200 filters each
^ Additive (list type, e.g., chelation agent, flocculent): HCI added after the Well 12 air stripper
^ Others: Vapor phase GAC for air stripper off-gas. Ion exchange (IX) system for perchlorate (currently inactive)
^ Good condition Q Needs O&M
^ Sampling ports properly marked and functional
~ Sampling/maintenance log displayed and up to date
^ Equipment properly identified
Q Quantity of groundwater treated annually (list volume):
Remarks: Air stripper is at maximum capacity, but can't remove PCE to ND: pre-filters (upstream of IX and LGAC) need
to be changed -every 4 months; LGAC vessels are single pass, so CDPH requires change with a detection at the 50%
port; two booster pumps at Well 12 the pump the stripper effluent through the LGAC system and to the settling tanks.
2.
Electrical Enclosures and Panels (properly rated and functional) ~ N/A
^ Good condition ~ Needs 0& M
Remarks: Well 15 is eauipped with a VFD. All operational readinas/data are recorded bv the SCADA system and
transmitted back to the Delta Plant.
3.
Tanks, Vaults, Storage Vessels ~ N/A
^ Good condition ~ Proper secondary containment ~ Needs O&M
Remarks: There are two small (190,000 gallons each) settling tanks at the Delta Plant.
4.
Discharge Structure and Appurtenances ~ N/A
^ Good condition ~ Needs 0& M
Remarks: The booster pumps that pump the water back to the Citv are old. The Citv plans to replace the pumps and
provide a backup generator as part of the construction of the new centralized treatment facility at the Delta Plant
(described below in "Overall Observations")
5.
Treatment Building(s) QN/A
^ Good condition (esp. roof and doorways) ~ Needs Repair
^ Chemicals and equipment properly stored
Remarks: No buildinas or chemicals at Well 15. Well 12 has a small storaae shed. In addition, Well 12 has a 10,000
gallon HCL tank that includes secondary containment. The buildings at the Delta Plant are in good shape. They
generate the chlorine for disinfection on-site using food-grade salt.
SGArea1_FYR_SiteInspectionChecklist_MPWell12_15_dt.doc Page 4 of 11
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Monterey Park Well 12/15 Site Inspection Checklist
6. Monitoring Wells (pump and treatment remedy) Q N/A
^ All required wells located ^ Properly secured/locked ^ Functioning^ Routinely sampled
M Good condition Q Needs O&M
Remarks: Monitoring wells are not on-site and were not included in the inspection. However, EPA routinely samples all
of the required monitoring wells and all are functioning and in good condition.
5. Long Term Monitoring ^ Applicable QN/A
1. Monitoring Wells- See preceding entry regarding the status of monitoring wells associated with the remedy.
X. OTHER REMEDIES ~ Applicable MN/A
If there are remedies applied at the site which are not covered above, attach an inspection sheet describing the physical
nature and condition of any facility associated with the remedy. An example would be soil vapor extraction.
XI. OVERALL OBSERVATIONS
1. Implementation of the Remedy
Describe issues and observations relating to whether the remedy is effective and functioning as designed. Begin with a brief
statement of what the remedy is to accomplish (i.e., to contain contaminant plume, minimize infiltration and gas emission,
etc.).
The City frequently has difficulty achieving the Well 12/15 target pumping rates for containment because the treatment system
capacity, combined with other CDPH permit limitations, does not allow much flexibility to make up for down time or times with
reduced pumping. EPA's recent evaluation indicates that the remedy is still achieving containment despite Well 12/15
frequently not meeting their minimum quarterly pumping targets.
2. Adequacy of O&M
Describe issues and observations related to the implementation and scope of O&M procedures. In particular, discuss their
relationship to the current and long-term protectiveness of the remedy.
The elevated PCE concentrations present in Wells 12/15 have resulted in the air stripper not being able to remove all of the
PCE. Although the existing dual barrier LGAC system addresses this issue, CDPH has expressed some concerns with the air
stripper's performance.
3. Early Indicators of Potential Remedy Failure
Describe issues and observations such as unexpected changes in the cost or scope of O&M or a high frequency of
unscheduled repairs that suggest that the protectiveness of the remedy may be compromised in the future.
Nothing significant, although there are some concerns as noted above in #1 of this section and in Chris Arriola's interview.
The City does not currently have any ability to treat for 1,4-dioxane which could be a major issue if concentrations were to
increase further.
4. Opportunities for Optimization
Describe possible opportunities for optimization in monitoring tasks or the operation of the remedy.
The City anticipates constructing a new, centralized treatment facility at the Delta Plant. The centralized plant is currently in
the early planning stages. The new facility would be designed to treat the water from all of the city's active wells and include
UV/Ox treatment to address 1,4-dioxane followed by LGAC polishing using existing vessels at Delta. The Well 12 air stripper
and Well 5 LGAC systems would be eliminated.
SGArea1_FYR_SiteInspectionChecklist_MPWell12_15_dt.doc Page 5 of 11
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Monterey Park Well 12/15 Site Inspection Checklist
Inspection Team Roster
Name
Organization
Title
Rachelle Thompson
U.S. EPA Region 9
Remedial Project Manager
David Towell
CH2M HILL
EPA Contractor
Chris Arriola
City of Monterey Park
Water Utilities Manager
Tom Ruggeri
City of Monterey Park
Sr. Water Production Specialist
6
-------
San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Monterey Park Well 12/15 Site Inspection Checklist
Photo 2: MP Well 12 Air Stripper and VGAC Vessel
7
-------
San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Monterey Park Well 12/15 Sue Inspection Checklist
Photo 3: HC1 Acid Storage Tank and VGAC Vessel
Photo 4: Well 12 Facility Electrical Cabinets
8
-------
San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Monterey Park Well 12/15 Site Inspection Checklist
Photo 5: Well 12 Facility Booster Pumps
Photo 6: MP Well 15 Wellhead
9
-------
San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Monterey Park Well 12/15 Site Inspection Checklist
Photo 7: Pre-Filters for LGAC Vessels
Photo 8: Dual Barrier LGAC Vessels
10
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Monterey Park Well 12/15 Site Inspection Checklist
MICRO u ok
Photo 9: Delta Plant Chlorine Generation Unit
Photo 10: Delta Plant Booster Pumps
11
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This page is intentionally left blank.
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San Gabriel Valley Area 1 Superfund Site
Los Angeles County, California
Five-Year Review Site Inspection Checklist
SEMOU - GSWC SAN GABRIEL FACILITY
I. SITE INFORMATION
Site Name: San Gabriel Valley Area 1 Superfund Site
EPA ID: CAD980677355
City/State: Rosemead, CA
Date of Inspection: March 20, 2013
Agency Completing 5 Year Review: USEPA
Weather/temperature: Hazy, Upper 60s
Remedy Includes: (Check all that apply)
O Landfill cover/containment
O Access controls
~ Institutional controls
H Groundwater pump and treatment
O Surface water collection and treatment
Attachments: M Inspection team roster attached ~ Site map attached
II. INTERVIEWS (Check all that apply)
1. GSWC Management
Contact: David Chang
Title: Vice President Environmental Quality
Date: 2/27/13
Interviewed: ~ at site Ogt office ^ by phone Phone Number:
Problems, suggestions: ~ Additional report attached (if additional space required).
See Interview Form in Appendix C.
2. Local regulatory authorities and response agencies (i.e., State and Tribal offices, emergency response office, police
department, office of public health or environmental health, zoning office, recorder of deeds, or other city and county
offices, etc.) None interviewed.
3. Other interviews (optional) ON/A ^ Additional report attached (See Interview Forms in Appendix C).
Water Purveyors- City of Monterey Park, San Gabriel Valley Water Company, Suburban Water Systems, Rurban Mutual,
Hemlock Mutual
Water Management Agencies- Main San Gabriel Basin Watermaster, San Gabriel Basin Water Quality Authority
III. ONSITE DOCUMENTS & RECORDS VERIFIED (Check all that apply)
1. O&M Documents
H O&M Manuals H Readily available H Up to date ~ N/A
S As-Built Drawings S Readily available S Up to date ON/A
M Maintenance Logs M Readily available O Up to date O N/A
Remarks: There is an on-site logbook used to track routine operational observations. In addition, each operator has a
notebook to record O&M activities. The operator notebook info is transferred into GSWC's computerized tracking
system. Separate from the inspection, GSWC has provided the latest version of their as-built drawings and operations,
maintenance and monitoring plan (OMMP).
SGArea1_FYR_SiteInspectionChecklist_GSWC_photos.doc Page 1 of 10
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, GSWC San Gabriel Plant Site Inspection Checklist
2.
Health and Safety Plan Documents
O Site-Specific Health and Safety Plan ~ Readily available ~ Up to date M N/A
H Contingency plan/emergency response plan H Readily available H Up to date ~ N/A
Remarks: Each district has an overall emeraencv response plan. Copies are kept at the district office and the water
operator's office. The plan is reviewed annually and updated as necessary.
3.
O&M and OSHA Training Records M Readily available JSl Up to date ON/A
Remarks: CDPH reauires that operators of this facility be T-2 certified (at a minimum). All 6 of GSWC's operators have at
least a T-2 certification. Training and certification information is provided to CDPH annually. Records are kept at
GSWC's offices
4.
Permits and Service Agreements
l~l Air discharge permit l~l Readily available dUptodate E3 N/A
E3 Effluent discharge ^ Readily available ^ Up to date ON/A
O Waste disposal, POTW O Readily available O Up to date O N/A
O Other permits O.Readily available O Up to date ^ N/A
Remarks: Effluent discharge is covered bv the CDPH permit, which was updated last vear when SG-2 was re-activated.
They also have an NPDES permit to discharge backwash water to the wash. Neither permit was reviewed as part of the
inspection.
5.
Groundwater Monitoring Records ^ Readily available El Up to date O N/A
Remarks: Groundwater monitoring for the South El Monte OU remedy is conducted by EPA. GSWC is not involved.
6.
Discharge Compliance Records ^ Readily available ^ Up to date O N/A
Remarks: All of the CDPH-permit reauired monitoring, including the wells, LGAC vessels and plant effluent, is conducted
by GSWC and the analyses are done in accordance with the CDPH permit. The lab submits the data directly to CDPH.
7.
Daily Access/Security Logs ^ Readily available El Up to date ON/A
Remarks: The daily access log is part of the on-site logbook kept at the plant.
IV. O&M Costs ^Applicable ON/A
1.
O&M Organization
O State in-house O Contractor for State
O PRP in-house O Contractor for PRP
^ Other: GSWC operates the facility.
2.
O&M Cost Records-
S Readily available ^ Up to date ^ Funding mechanism/agreement in place
Remarks: Not reviewed as part of the Site Inspection, but EPA reviews O&M costs on a auarterlv basis.
3.
Unanticipated or Unusually High O&M Costs During Review Period ^ N/A
Describe costs and reasons:
V. ACCESS AND INSTITUTIONAL CONTROLSApplicable ~ N/A
1.
Fencing
1.
Fencing damaged O Location shown on site map ^ Gates secured O N/A
Remarks: Main fence is in good shape. There is a small gap at the back corner of the facility along the wash.
SGArea1_FYR_SiteInspectionChecklist_GSWC_photos.doc
Page 2 of 10
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, GSWC San Gabriel Plant Site Inspection Checklist
2. Other Access Restrictions
1. Signs and other security measures Q Location shown on site map Q N/A
Remarks: The front gate has a warning sign.
3. Institutional Controls
1. I mplementation and enforcement
Site conditions imply ICs not properly implemented:
OYes
O
No
M
N/A
Site conditions imply ICs not being fully enforced:
OYes
O
No
M
N/A
Reporting is up-to-date:
OYes
O
No
M
N/A
Reports are verified by the lead agency:
OYes
O
No
M
N/A
Specific requirements in deed or decision documents have been
met: O Yes
O
No
B
N/A
Violations have been reported:
OYes
O
No
M
N/A
2.
Adequacy O ICs are adequate O ICs are inadequate
Remarks:
MN/A
4.
General
1.
Vandalism/trespassing O Location shown on site map
Remarks: GSWC has not had anv issues with vandalism or trespassina.
B No vandalism evident
2.
Land use changes onsite
Remarks: None
ON/A
3.
Land use changes offsite
Remarks: None
ON/A
VI. GENERAL SITE CONDITIONS
1.
Roads O Applicable ^N/A
1.
Roads damaged O Location shown on site map O Roads adequate ^ N/A
Remarks:
2.
Other Site Conditions
Remarks: Nothina of note.
IX. GROUNDWATER/SURFACE WATER REMEDIES M Applicable ~ N/A
1. Groundwater Extraction Wells, Pumps, and Pipelines ^Applicable ON/A
1. Pumps, Wellhead Plumbing, and Electrical ON/A
O All required wells located M Good condition O Needs 0& M
Remarks: The SG-1 pump was replaced in Spring 2011. The SG-2 pump was replaced in Fall 2012.
2. Extraction System Pipelines, Valves, Valve Boxes, and Other Appurtenances O N/A
O System located O Good condition O Needs 0& M
Remarks:
SGArea1_FYR_SiteInspectionChecklist_GSWC_photos.doc
Page 3 of 10
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, GSWC San Gabriel Plant Site Inspection Checklist
3.
Spare Parts and Equipment ^ N/A
Remarks:
2.
Treatment System ^Applicable QN/A
1.
Treatment Train (Check components that apply)
Q Metals removal Q Oil/water separation Q Bioremediation
~ Air stripping ^ Carbon adsorbers ~ Filters (list type):
~ Additive (list type, e.g., chelation agent, flocculent)
~ Others (list):
^ Good condition Q Needs O&M
^ Sampling ports properly marked and functional
~ Sampling/maintenance log displayed and up to date
^ Equipment properly identified
Q Quantity of groundwater treated annually (list volume):
Remarks: LGAC vessel pipina and valve tree were recently cleaned and painted. In-line nitrate analyzers were added in
2012 as part of the CDPH-approved nitrate blending plan that allowed SG-2 to return to service.
2.
Electrical Enclosures and Panels (properly rated and functional) Q N/A
^ Good condition ~ Needs 0& M
Remarks: All operational readinas/data are recorded by the SCADA system and transmitted back to the office.
3.
Tanks, Vaults, Storage Vessels Q N/A
^ Good condition ~ Proper secondary containment ~ Needs O&M
Remarks: There is only one tank on-site (-40,000 gallon capacity). It is used to hold backwash water prior to discharge.
4.
Discharge Structure and Appurtenances Q N/A
^ Good condition ~ Needs 0& M
Remarks: The extraction wells pump the water throuah the LGAC vessels at system pressure (-80 psi) and directly into
GSWC's distribution system. There are no booster pumps.
5.
Treatment Building(s) ON/A
^ Good condition (esp. roof and doorways) ~ Needs Repair
^ Chemicals and equipment properly stored (Only chemical is the sodium hypochlorite for disinfection.)
Remarks: There is a buildina surroundina the SG-1 well and a small buildina to contain the sodium hypochlorite.
6.
Monitoring Wells (pump and treatment remedy) ~ N/A
^ All required wells located ^ Properly secured/locked ^ Functioning^ Routinely sampled
^ Good condition Q Needs O&M
Remarks: Monitorina wells are not on-site and were not included in the inspection. However, EPA routinely samples all
of the required monitoring wells and all are functioning and in good condition.
3.
Long Term Monitoring ^ Applicable Q N/A
1. Monitoring Wells- See preceding entry regarding the status of monitoring wells associated with the remedy.
X. OTHER REMEDIES ~ Applicable MN/A
If there are remedies applied at the site which are not covered above, attach an inspection sheet describing the physical
nature and condition of any facility associated with the remedy.
SGArea1_FYR_SiteInspectionChecklist_GSWC_photos.doc Page 4 of 10
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, GSWC San Gabriel Plant Site Inspection Checklist
XI. OVERALL OBSERVATIONS
1. Implementation of the Remedy
Describe issues and observations relating to whether the remedy is effective and functioning as designed. Begin with a brief
statement of what the remedy is to accomplish (i.e., to contain contaminant plume, minimize infiltration and gas emission,
etc.).
Now that well SG-2 is on-line, GSWC does not expect to have any significant issues meeting EPA's minimum target rates for
containment. No other major issues noted, but see the interview form for David Chang/GSWC for additional detail.
2. Adequacy of O&M
Describe issues and observations related to the implementation and scope of O&M procedures. In particular, discuss their
relationship to the current and long-term protectiveness of the remedy.
Nothing significant, but see the interview form for David Chang/GSWC for some potential issues.
3. Early Indicators of Potential Remedy Failure
Describe issues and observations such as unexpected changes in the cost or scope of O&M or a high frequency of
unscheduled repairs that suggest that the protectiveness of the remedy may be compromised in the future.
Nothing significant, but see the interview form for David Chang/GSWC for some potential concerns.
4. Opportunities for Optimization
Describe possible opportunities for optimization in monitoring tasks or the operation of the remedy.
GSWC is not currently considering any optimization activities. However, if nitrate levels remain where they are now for
several more months, they may approach CDPH regarding increasing the allowable flow rate from SG-2.
SGArea1_FYR_SiteInspectionChecklist_GSWC_photos.doc
Page 5 of 10
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, GSWC San Gabriel Plant Site Inspection Checklist
Inspection Team Roster
Name
Organization
Title
Rachelle Thompson
U.S. EPA Region 9
Remedial Project Manager
David Towell
CH2M HILL
EPA Contractor
David Chang
GSWC
Vice President Environmental Quality
Stacey Roberts
GSWC
Water Quality Engineer
Drew Williams
GSWC
Operations Foreman
6
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, GSWC San Gabriel Plant Site Inspection Checklist
Photo 1: GSWC SGI Wellhead
Photo 2: GSWC SG2 Wellhead
7
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, GSWC San Gabriel Plant Site Inspection Checklist
Photo 3: In-Line Mixer for blending SGI and SG2
Photo 4: In-line Nitrate Analyzers
8
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, GSWC San Gabriel Plant Site Inspection Checklist
Photo 5: LGAC Vessels
Photo 6: Electrical Panels and Backwash Storage Tank
9
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, GSWC San Gabriel Plant Site Inspection Checklist
ChemicalS!
Syst*"1
Photo 7: Chlorine Storage Shed
10
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San Gabriel Valley Area 1 Superfund Site
Los Angeles County, California
Five-Year Review Site Inspection Checklist
SEMOU - SGVWC PLANT 8 FACILITY
I. SITE INFORMATION
Site Name: San Gabriel Valley Area 1 Superfund Site
EPA ID: CAD980677355
City/State: South El Monte, CA
Date of Inspection: March 20, 2013
Agency Completing 5 Year Review: USEPA
Weather/temperature: Hazy, Low 70s
Remedy Includes: (Check all that apply)
O Landfill cover/containment
O Access controls
~ Institutional controls
H Groundwater pump and treatment
O Surface water collection and treatment
Attachments: M Inspection team roster attached ~ Site map attached
II. INTERVIEWS (Check all that apply)
1. SGVWC Management:
Contact: Frank LoGuidiceA/ice President Engineering and Operations, Dan ArrighiA/ice President Water Quality and
Planning, Oscar Ramos/Water Quality Superintendent
Date: 2/27/13
Interviewed: Q at site Q at office ^ by phone Phone Number:
Problems, suggestions: n Additional report attached (if additional space required).
See Interview Form in Appendix C.
2. Local regulatory authorities and response agencies (i.e., State and Tribal offices, emergency response office, police
department, office of public health or environmental health, zoning office, recorder of deeds, or other city and county
offices, etc.) None interviewed.
3. Other interviews (optional) QN/A ^ Additional report attached (See Interview Forms in Appendix C).
Water Purveyors- Golden State Water Company, City of Monterey Park, Suburban Water Systems, Rurban Mutual,
Hemlock Mutual
Water Management Agencies- Main San Gabriel Basin Watermaster, San Gabriel Basin Water Quality Authority.
III. ONSITE DOCUMENTS & RECORDS VERIFIED (Check all that apply)
1. O&M Documents
M O&M Manuals M Readily available ~ Up to date ~ N/A
H As-Built Drawings H Readily available HUptodate QN/A
M Maintenance Logs H Readily available H Up to date ~ N/A
Remarks: SGVWC operators fill out a daily log form 7 days a week that includes operational readings and documents
any O&M activities. The operators turn these in at SGVWC's main office each day. The as-built drawings and
maintenance logs are also kept at the main office, but were not observed during the inspection. SGVWC is working with
CDPH to finalize an update to their OM&M Plan. They have up-to-date operational procedures and monitoring
requirements, but not all have been formally incorporated into the OM&M Plan.
SGArea1_FYR_SiteInspectionChecklist_SGVWCPlant8_dt_rev1.doc
Page 1 of 10
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, SGVWC Plant 8 Site Inspection Checklist
2. Health and Safety Plan Documents
O Site-Specific Health and Safety Plan ~ Readily available ~ Up to date M N/A
H Contingency plan/emergency response plan H Readily available H Up to date ~ N/A
Remarks: SGVWC does not have site-specific safety plans. They have an overall emergency response plan. Also, they
are updating their contingency plan based on a treatment plant failure that occurred last year at one of their Baldwin Park
OU treatment plants.
3. O&M and OSHA Training Records H Readily available M Up to date ON/A
Remarks: SGVWC operators are not typically OSHA trained. CDPH requires that the system operators be T-2/D-1
certified (at a minimum). Most SGVWC operators have much higher certifications, including 6 at the T-4 level. Training
and certification information is provided to CDPH annually and is kept at the SGVWC offices.
4. Permits and Service Agreements
E3 Air discharge permit E3 Readily available ^JJptodate l~l N/A
E3 Effluent discharge ^ Readily available ^ Up to date ON/A
Waste disposal, POTW ^ Readily available O Up to date O N/A
O Other permits O-Readily available O Up to date O N/A
Remarks: SGVWC has an AQMD permit for the Plant 8 air stripper. The permit is updated annually. Effluent discharge
is covered by the CDPH permit, which was last updated in 2006 with the addition of the LGAC system. The City has an
NPDES permit to cover discharge of water to the wash- primarily backwash water from the LGAC vessels. SGVWC
notifies the RWQCB in advance of discharging. None of the permits were directly reviewed as part of the inspection.
5. Groundwater Monitoring Records O Readily available ^ Up to date O N/A
Remarks: Groundwater monitoring for the South El Monte OU remedy is conducted by EPA. SGVWC is only involved
with the SEMW-09 well (an early warning well for Plant 8), which is sampled annually by Stetson on their behalf.
6. Discharge Compliance Records O Readily available ^ Up to date O N/A
Remarks: All of the CDPH-permit required monitoring, including the wells, air stripper, LGAC vessels and plant effluent, is
conducted by SGVWC and the analyses are done in accordance with the CDPH permit. The lab submits the data directly to
CDPH. In addition, the SGVWC submits monthly reports and an annual report to CDPH. SGVWC has an AQMD permit for
activated carbon, an emergency generator, and the groundwater treatment system (air stripper and carbon adsorber).
7. Daily Access/Security Logs ^ Readily available ^ Up to date ON/A
Remarks: SGVWC operators perform daily checks at Plant 8. The daily checks are documented in the operator's daily
logs that are stored at SGVWC's offices.
IV. O&M Costs OApplicable ON/A
1. O&M Organization
O State in-house O Contractor for State
O PRP in-house O Contractor for PRP
^ Other: SGVWC operates the facility.
2. O&M Cost Records-
^ Readily available J3 Up to date ^ Funding mechanism/agreement in place
Remarks: Not reviewed as part of the Site Inspection, but EPA reviews O&M costs on a quarterly basis
3. Unanticipated or Unusually High O&M Costs During Review Period O N/A
Describe costs and reasons: None.
V. ACCESS AND INSTITUTIONAL CONTROLSApplicable O N/A
SGArea1_FYR_SiteInspectionChecklist_SGVWCPlant8_dt_rev1.doc
Page 2 of 10
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, SGVWC Plant 8 Site Inspection Checklist
1. Fencing
1. Fencing damaged Q Location shown on site map ^ Gates secured Q N/A
Remarks: The site is fully fenced and gates secured.
2. Other Access Restrictions
1. Signs and other security measures ~ Location shown on site map ~ N/A
Remarks: There are no specific warning signs at the facility. The booster pump building that also houses the electrical
equipment and chlorination system is equipped with an alarm.
3. Institutional Controls
1. I mplementation and enforcement
Site conditions imply ICs not properly implemented:
~ Yes
O
No
M
N/A
Site conditions imply ICs not being fully enforced:
~ Yes
O
No
B
N/A
Reporting is up-to-date:
~ Yes
~
No
M
N/A
Reports are verified by the lead agency:
~ Yes
~
No
M
N/A
Specific requirements in deed or decision documents have been
met: ~ Yes
O
No
M
N/A
Violations have been reported:
~ Yes
O
No
B
N/A
2. Adequacy ~ ICs are adequate ~ ICs are inadequate ^ N/A
Remarks:
4. General
1. Vandalism/trespassing ~ Location shown on site map ~ No vandalism evident
Remarks: SGVWC has not had any issues with trespassing or vandalism at Plant 8.
2. Land use changes onsite ~ N/A
Remarks: None.
3. Land use changes offsite ~ N/A
Remarks: None.
VI. GENERAL SITE CONDITIONS
1. Roads Q Applicable ^N/A
1. Roads damaged ~ Location shown on site map ~ Roads adequate ~ N/A
Remarks:
2. Other Site Conditions
Remarks: Nothing of note.
SGArea1_FYR_SiteInspectionChecklist_SGVWCPlant8_dt_rev1.doc
Page 3 of 10
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, SGVWC Plant 8 Site Inspection Checklist
IX. GROUNDWATER/SURFACE WATER REMEDIES M Applicable ~ N/A
1.
Groundwater Extraction Wells, Pumps, and Pipelines ^Applicable ON/A
1.
Pumps, Wellhead Plumbing, and Electrical Q N/A
^ All required wells located ^ Good condition ~ Needs 0& M
Remarks: The three remedy wells 8B, 8C and 8D are all located on the Plant 8 property alona with the two deeper non-
remedy wells 8E and 8F. Pumping from the wells is controlled by set points that maintain water levels in the on-site
reservoirs. 8E and 8F are used minimally except during peak demand periods.
2.
Extraction System Pipelines, Valves, Valve Boxes, and Other Appurtenances ~ N/A
^ System located ^ Good condition ~ Needs 0& M
Remarks: All of the wells except 8F (which does not contain anv VOCs) are plumbed into the same line that serves as
the air stripper influent.
3.
Spare Parts and Equipment ^ N/A
Remarks:
3.
Treatment System ^Applicable QN/A
1.
Treatment Train (Check components that apply)
~ Metals removal ~ Oil/water separation ~ Bioremediation
^ Air stripping ^ Carbon adsorbers (6 vessels) ~ Filters:
Additive (list type, e.g., chelation agent, flocculent): HCI added after the Plant 8 air stripper. 1,550 gallon acid tank.
SGVWC uses about V2 tank per month.
^ Others: Vapor phase GAC for air stripper off-gas. Carbon only changed on breakthrough and lasts for years.
^ Good condition ~ Needs O&M
^ Sampling ports properly marked and functional
O Sampling/maintenance log displayed and up to date
^ Equipment properly identified
O Quantity of groundwater treated annually (list volume):
Remarks: There are lead-laa booster pumps after the air stripper that boost the water throuah the LGAC vessels and into
the on-site storage tanks.
2.
Electrical Enclosures and Panels (properly rated and functional) ~ N/A
^ Good condition Q Needs O& M
Remarks: The electrical eauipment for all of the wells and booster pumps is located in the booster pump buildina. All
operational readings/data are recorded by the SCADA system and transmitted back to the SGVWC main control room.
3.
Tanks, Vaults, Storage Vessels Q N/A
^ Good condition ~ Proper secondary containment ~ Needs O&M
Remarks: There are two large (600,000 gallons each) storage tanks at Plant 8 and also a backwash water tank.
4.
Discharge Structure and Appurtenances Q N/A
^ Good condition ~ Needs O& M
Remarks: There are 5 booster pumps that pump the water from the tanks into SGVWC's system. The booster pumps are
controlled by maintaining system pressure at 80 to 90 psi.
5.
Treatment Building(s) ON/A
^ Good condition (esp. roof and doorways) ~ Needs Repair
^ Chemicals and equipment properly stored
Remarks: Plant 8 has one buildina that contains the booster pumps, electrical eauipment and chlorination system. The
building is in good shape. There is a small three-sided storage building that contains the HCI tank.
SGArea1_FYR_SiteInspectionChecklist_SGVWCPlant8_dt_rev1.doc
Page 4 of 10
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, SGVWC Plant 8 Site Inspection Checklist
6. Monitoring Wells (pump and treatment remedy) Q N/A
^ All required wells located ^ Properly secured/locked ^ Functioning^ Routinely sampled
M Good condition Q Needs O&M
Remarks: Monitoring wells are not at Plant 8 and were not included in the inspection. However, EPA routinely samples all
of the required monitoring wells and all are functioning and in good condition. Stetson samples SEMW-09 annually.
5. Long Term Monitoring ^ Applicable QN/A
1. Monitoring Wells- See preceding entry regarding the status of monitoring wells associated with the remedy.
X. OTHER REMEDIES ~ Applicable MN/A
If there are remedies applied at the site which are not covered above, attach an inspection sheet describing the physical
nature and condition of any facility associated with the remedy. An example would be soil vapor extraction.
XI. OVERALL OBSERVATIONS
1. Implementation of the Remedy
Describe issues and observations relating to whether the remedy is effective and functioning as designed. Begin with a brief
statement of what the remedy is to accomplish (i.e., to contain contaminant plume, minimize infiltration and gas emission,
etc.).
Generally, SGVWC does not have any problems meeting the combined minimum Plant 8 target pumping rates for
containment. SGVWC does have concerns about the presence of perchlorate and 1,4-dioxane and has treatment system
designs ready to go if concentrations of those constituents increase. See the SGVWC interview form for additional details.
2. Adequacy of O&M
Describe issues and observations related to the implementation and scope of O&M procedures. In particular, discuss their
relationship to the current and long-term protectiveness of the remedy.
There are no significant issues related to Plant 8 O&M procedures that impact remedy performance.
3. Early Indicators of Potential Remedy Failure
Describe issues and observations such as unexpected changes in the cost or scope of O&M or a high frequency of
unscheduled repairs that suggest that the protectiveness of the remedy may be compromised in the future.
There have not been any O&M issues that indicated potential future failure of the remedy. However, as noted above, if
perchlorate or 1,4-dioxane concentrations increase new treatment systems will be required. SGVWC's other main concerns
would if new contaminants showed up or if water quality standards were lowered for existing contaminants.
4. Opportunities for Optimization
Describe possible opportunities for optimization in monitoring tasks or the operation of the remedy.
SGVWC does not have any current plans for optimization and did not identify potential opportunities for optimization.
SGArea1_FYR_SiteInspectionCheckust_SGVWCPlant8_dt_rev1.doc
Page 5 of 10
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, SGVWC Plant 8 Site Inspection Checklist
Inspection Team Roster
Name
Organization
Title
Rachelle Thompson
U.S. EPA Region 9
Remedial Project Manager
David Towell
CH2M HILL
EPA Contractor
Oscar Ramos
SGVWC
Water Quality Superintendent
Paul Smit
SGVWC
Water Production Foreman
6
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, SGVWC Plant 8 Site Inspection Checklist
Photo 1: SGVWC Well 8B
Photo 2: SGVWC Well 8C
7
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, SGVWC Plant 8 Site Inspection Checklist
Photo 3: SGVWC Well 8D
Photo 4: Plant 8 Air Stripper and VGAC Vessel
8
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, SGVWC Plant 8 Site Inspection Checklist
Photo 5: Plant 8 LGAC Vessels
HydraclteW
Warning
Photo 6: Plant 8 HC1 Acid Storage Tank
9
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, SGVWC Plant 8 Site Inspection Checklist
Esia
CHLORINE
AR|A
MHME
Photo 7: Plant 8 Chlorine Storage and Feed Pumps
Photo 8: Plant 8 Booster Pump/Electrical Equipment Building and Storage Tanks
10
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San Gabriel Valley Area 1 Superfund Site
Los Angeles County, California
Five-Year Review Site Inspection Checklist
RICHWOOD OU
1. SITE INFORMATION
Site Name: San Gabriel Valley Area 1 Superfund Site
EPA ID: CAD980677355
City/State: El Monte, CA
Date of Inspection: March 20, 2013
Agency Completing 5 Year Review: USEPA
Weather/temperature: Hazy, Low 70s
Remedy Includes: (Check all that apply)
O Landfill cover/containment
~ Access controls
~ Institutional controls
S Groundwater pump and treatment
O Surface water collection and treatment
Attachments: M Inspection team roster attached ~ Site map attached
II. INTERVIEWS (Check all that apply)
1.
Richwood Mutual Water Company: N/A - Richwood Mutual Water Company no longer exists
2.
Local regulatory authorities and response agencies (i.e., State and Tribal offices, emergency response office, police
department, office of public health or environmental health, zoning office, recorder of deeds, or other city and county
offices, etc.) None interviewed.
3.
Other interviews (optional) ~ N/A ^ Additional report attached (See Interview Forms in Appendix C).
Water Purveyors- San Gabriel Valley Water Company (SGVWC). San Gabriel Valley Water Company purchased the
assets of Richwood Mutual Water Company and provides water to the former Richwood customers.
Water Management Agencies- Main San Gabriel Basin Watermaster, San Gabriel Basin Water Quality Authority.
III. ONSITE DOCUMENTS & RECORDS VERIFIED (Check all that apply)
1. O&M Documents
~ O&M Manuals ~ Readily available
~ As-Built Drawings ~ Readily available
O Maintenance Logs ~ Readily available
Remarks: All of the facilities associated with the former remedy in
abandoned and no longer exist.
~ Up to date H N/A
~ Up to date H N/A
O Up to date S N/A
the Richwood OU have been dismantled or
2. Health and Safety Plan Documents
O Site-Specific Health and Safety Plan ~ Readily available ~ Up to date M N/A
~ Contingency plan/emergency response plan ~ Readily available ~ Up to date H N/A
Remarks:
SGArea1_FYR_SiteInspectionChecklist_Richwood.doc
Page 1 of 6
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Richwood OU Site Inspection Checklist
3. O&M and OSHA Training Records ~ Readily available ~ Up to date S N/A
Remarks:
Permits and Service Agreements
l~l Air discharge permit |~| Readily available dllptodate E3 N/A
~_Effluent discharge |~| Readily available dUptodate E3 N/A
O Waste disposal, POTW |~| Readily available |~| Up to date E3 N/A
~ Other permits 0_Readily available D_Up to date E3 N/A
Remarks:
5. Groundwater Monitoring Records JJ_Readily available LLUp to date E3 N/A
Remarks: There are no recent groundwater monitoring records directly related to the Richwood OU, however, Stetson
Engineers (on behalf of the Main San Gabriel Basin Watermaster) does collect samples on an annual basis from
production wells in the general vicinity.
6. Discharge Compliance Records 0_Readily available D_Up to date E3 N/A
Remarks:
Daily Access/Security Logs |~| Readily available dUptodate E3 N/A
Remarks:
IV. O&M Costs ~ Applicable ~ N/A
1. O&M Organization- There have not been any O&M activities for more than a decade.
V. ACCESS AND INSTITUTIONAL CONTROLS _~ Applicable M N/A
1. Fencing
1. Fencing damaged Q Location shown on site map Q Gates secured ~ N/A
Remarks:
2. Other Access Restrictions
1. Signs and other security measures Q Location shown on site map ~ N/A
Remarks:
3. Institutional Controls
1. I mplementation and enforcement
Site conditions imply ICs not properly implemented:
~ Yes
~
No
M
N/A
Site conditions imply ICs not being fully enforced:
~ Yes
~
No
M
N/A
Reporting is up-to-date:
~ Yes
O
No
M
N/A
Reports are verified by the lead agency:
~ Yes
O
No
B
N/A
Specific requirements in deed or decision documents have been
met: ~ Yes
~
No
M
N/A
Violations have been reported:
~ Yes
~
No
M
N/A
2. Adequacy Q ICs are adequate Q ICs are inadequate ^ N/A
Remarks:
4. General
SGArea1_FYR_SiteInspectionChecklist_Richwood.doc
Page 2 of 6
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Richwood OU Site Inspection Checklist
1.
Vandalism/trespassing ~ Location shown on site map ^ No vandalism evident
Remarks:
2.
Land use changes onsite Q N/A
Remarks: The former treatment plant has been dismantled and a residence has been built.
3.
Land use changes offsite ~ N/A
Remarks: None.
VI. GENERAL SITE CONDITIONS
1.
Roads Q Applicable £3. N/A
1.
Roads damaged ~ Location shown on site map ~ Roads adequate ^ N/A
Remarks:
2.
Other Site Conditions
Remarks:
IX. GROUNDWATER/SURFACE WATER REMEDIES M Applicable
ON/A
1.
Groundwater Extraction Wells, Pumps, and Pipelines ^Applicable
ON/A
1.
Pumps, Wellhead Plumbing, and Electrical ^ N/A
~ All required wells located ~ Good condition ~ Needs 0& M
Remarks: The former Richwood Mutual wells have been abandoned.
2.
Extraction System Pipelines, Valves, Valve Boxes, and Other Appurtenances ^ N/A
~ System located ~ Good condition ~ Needs 0& M
Remarks: As noted above, the extraction wells have been abandoned.
3.
Spare Parts and Equipment ^ N/A
Remarks:
3.
Treatment System Q Applicable ON/A
1.
Treatment Train (Check components that apply)
~ Metals removal ~ Oil/water separation ~ Bioremediation
O Air stripping Q Carbon adsorbers Q Filters:
~ Additive (list type, e.g., chelation agent, flocculent):
Remarks: Historically, a aranular activated carbon (GAC) system was used to treat the extracted aroundwater.
5.
Long Term Monitoring ~ Applicable O N/A
1.
Monitoring Wells- There were no monitoring wells specifically installed for the Richwood OU remedy.
X. OTHER REMEDIES ~ Applicable
ON/A
If there are remedies applied at the site which are not covered above, attach an inspection sheet describing the physical
nature and condition of any facility associated with the remedy. An example would be soil vapor extraction.
SGArea1_FYR_SiteInspectionChecklist_Richwood.doc
Page 3 of 6
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Richwood OU Site Inspection Checklist
XI. OVERALL OBSERVATIONS
1. Implementation of the Remedy
Describe issues and observations relating to whether the remedy is effective and functioning as designed. Begin with a brief
statement of what the remedy is to accomplish.).
The remedy was intended to provide treatment of Richwood Mutual Water Company's water supply. SGVWC purchased the
assets of Richwood Mutual and connected the customers to SGVWC's system. So, the remedy is no longer needed.
2. Adequacy of O&M
Describe issues and observations related to the implementation and scope of O&M procedures. In particular, discuss their
relationship to the current and long-term protectiveness of the remedy.
Not Applicable. The remedy has been inactive for well over 10 years and the former Richwood Mutual customers are supplied
by SGVWC.
3. Early Indicators of Potential Remedy Failure
Describe issues and observations such as unexpected changes in the cost or scope of O&M or a high frequency of
unscheduled repairs that suggest that the protectiveness of the remedy may be compromised in the future.
Not applicable.
4. Opportunities for Optimization
Describe possible opportunities for optimization in monitoring tasks or the operation of the remedy.
Not applicable.
SGArea1_FYR_SiteInspectionChecklist_Richwood.doc
Page 4 of 6
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Richwood OU Site Inspection Checklist
Inspection Team Roster
Name
Organization
Title
Rachelle Thompson
U.S. EPA Region 9
Remedial Project Manager
David Towell
CH2M HILL
EPA Contractor
5
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Richwood OU Site Inspection Checklist
Photo 1: The Richwood OU Treatment Plant was located at this address (behind the pictured
home). The location is now occupied by a second house.
6
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San Gabriel Valley Area 1 Superfund Site
Los Angeles County, California
Five-Year Review Site Inspection Checklist
SUBURBAN OU
I. SITE INFORMATION
Site Name: San Gabriel Valley Area 1 Superfund Site EPA ID: CAD980677355
City/State: Los Angeles County, CA Date of Inspection: March 20, 2013
Agency Completing 5 Year Review: USE PA Weather/temperature: Hazy, Low 70s
Remedy Includes: No remedy was implemented in the Suburban OU. However, Suburban Water Systems' (SWS) Bartolo well
field (the intended focus of the OU) is still active.
Q Landfill cover/containment
O Access controls
~ Institutional controls
~ Groundwater pump and treatment
~ Surface water collection and treatment
Attachments: M Inspection team roster attached Q Site map attached
II. INTERVIEWS (Check all that apply)
1. Suburban Water Systems (SWS) Management:
Contact: Craig Gott, Vice President Engineering; John Brettl, Quality Assurance Department; Ken Reich, Quality Assurance
Department; Kevin Hostert, Production Department; Josh Vaughn, Chief Operator Quality Assurance Department
Date: 2/25/13
Interviewed: ~ at site Q at office M by phone Phone Number:
Problems, suaaestions: fl Additional report attached (if additional space reauired).
See Interview Form in Appendix C.
2.
Local regulatory authorities and response agencies (i.e., State and Tribal offices, emergency response office, police
department, office of public health or environmental health, zoning office, recorder of deeds, or other city and county
offices, etc.) None interviewed.
3.
Other interviews (optional) Q N/A H. Additional report attached (See Interview Forms in Appendix C).
Water Purveyors- Golden State Water Company, City of Monterey Park, San Gabriel Valley Water Company, Rurban
Mutual, Hemlock Mutual
Water Management Agencies- Main San Gabriel Basin Watermaster, San Gabriel Basin Water Quality Authority.
III. ONSITE DOCUMENTS & RECORDS VERIFIED (Check all that apply)
1.
O&M Documents
Q O&M Manuals Q Readily available Q Up to date M N/A
O As-Built Drawings Q Readily available ~ Up to date M N/A
O Maintenance Logs Q Readily available ~ Up to date M N/A
Remarks:
SGArea1_FYR_SiteInspectionChecklist_Suburban.doc
Page 1 of 8
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Suburban OU Site Inspection Checklist
2. Health and Safety Plan Documents
Q Site-Specific Health and Safety Plan Q Readily available Q Up to date M N/A
~ Contingency plan/emergency response plan Q Readily available Q Up to date M N/A
Remarks:
3. O&M and OSHA Training Records Q Readily availableQ Up to date UN/A
Remarks:
4. Permits and Service Agreements
QAir discharge permit QReadily available QUp to date M.N/A
~.Effluent discharge QReadily available QUp to date j&N/A
~ Waste disposal, POTW QReadily available QUp to date j&N/A
O Other permits QReadily available QUp to date J&.N/A
Remarks:
5. Groundwater Monitoring Records H Readily available H Up to date ~ N/A
Remarks: There are no groundwater monitoring records that are specifically associated with the Suburban OU. However,
SWS' Bartolo wells are routinely monitored and recent results were obtained. In addition, EPA routinely monitors
groundwater throughout Whittier Narrows, including upgradient of the Bartolo well field.
6. Discharge Compliance Records ~ Readily available QUp to date H N/A
Remarks:
Daily Access/Security Logs ~ Readily available ~ Up to date H N/A
Remarks:
IV. O&M Costs Q Applicable N/A
1. O&M Organization
V. ACCESS AND INSTITUTIONAL CONTROLS Q Applicable ^ N/A
1. Fencing - The Bartolo well field wells are all fully fenced and secured.
1. Fencing damaged Q Location shown on site map Q Gates secured )& N/A
Remarks:
Other Access Restrictions
1. Signs and other security measures Q Location shown on site map M.N/A
Remarks:
Institutional Controls
Implementation and enforcement
Site conditions imply ICs not properly implemented: Q Yes Q No J&N/A
Site conditions imply ICs not being fully enforced: Q Yes Q No )& N/A
Reporting is up-to-date: Q Yes Q No J&N/A
Reports are verified by the lead agency: Q Yes Q No )& N/A
Specific requirements in deed or decision documents have been met: Q Yes Q No j& N/A
Violations have been reported: Q Yes Q No J&N/A
SGArea1_FYR_SiteInspectionChecklist_Suburban.doc
Page 2 of 8
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Suburban OU Site Inspection Checklist
2.
Adequacy ~ ICs are adequate ~ ICs are inadequate IN/A
Remarks:
4.
General
1.
Vandalism/trespassing Q Location shown on site map H. No vandalism evident
Remarks:
2.
Land use changes onsite Q N/A
Remarks: The oriainal Bartolo Well Field wells have been abandoned and replaced with newer production wells located in
the same area.
3.
Land use changes offsite Q N/A
Remarks: None.
VI. GENERAL SITE CONDITIONS
1.
Roads ~ Applicable gj|\|/A
1.
Roads damaged Q Location shown on site map Q Roads adequate N/A
Remarks:
2.
Other Site Conditions
Remarks:
IX. GROUNDWATER/SURFACE WATER REMEDIES Q Applicable
a N/A
1.
Groundwater Extraction Wells, Pumps, and Pipelines Q Applicable
MN/A
1.
Pumps, Wellhead Plumbing, and Electrical H N/A
~ All required wells located Q Good condition Q Needs 0& M
Remarks:
2.
Extraction System Pipelines, Valves, Valve Boxes, and Other Appurtenances N/A
~ System located Q Good condition Q Needs 0& M
Remarks:
3.
Spare Parts and Equipment H N/A
Remarks:
3.
Treatment System Q Applicable H.N/A
1.
Treatment Train (Check components that apply)
~ Metals removal Q Oil/water separation Q Bioremediation
~ Air stripping ~ Carbon adsorbers Q Filters:
Q Additive (list type, e.g., chelation agent, flocculent):
Remarks:
5.
Long Term Monitoring ~Applicable H N/A
1.
Monitoring Wells- There were no monitoring wells specifically installed for the Suburban OU.
SGArea1_FYR_SiteInspectionChecklist_Suburban.doc
Page 3 of 8
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Suburban OU Site Inspection Checklist
X. OTHER REMEDIES ~.Applicable EN/A
If there are remedies applied at the site which are not covered above, attach an inspection sheet describing the physical nature
and condition of any facility associated with the remedy. An example would be soil vapor extraction.
XI. OVERALL OBSERVATIONS
1. Implementation of the Remedy
Describe issues and observations relating to whether the remedy is effective and functioning as designed. Begin with a brief
statement of what the remedy is to accomplish.).
The ROD called for monitoring of the SWS Bartolo wells and contingent installation of a treatment system if contaminant levels
increased. No active remedy was ever installed because contaminant levels remained low.
2. Adequacy of O&M
Describe issues and observations related to the implementation and scope of O&M procedures. In particular, discuss their
relationship to the current and long-term protectiveness of the remedy.
Not Applicable.
3. Early Indicators of Potential Remedy Failure
Describe issues and observations such as unexpected changes in the cost or scope of O&M or a high frequency of
unscheduled repairs that suggest that the protectiveness of the remedy may be compromised in the future.
Not applicable.
4. Opportunities for Optimization
Describe possible opportunities for optimization in monitoring tasks or the operation of the remedy.
Not applicable.
SGArea1_FYR_SiteInspectionChecklist_Suburban.doc
Page 4 of 8
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Suburban OU Site Inspection Checklist
Inspection Team Roster
Name
Organization
Title
Rachelle Thompson
U.S. EPA Region 9
Remedial Project Manager
David Towell
CH2M HILL
EPA Contractor
5
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Suburban OU Site Inspection Checklist
Photo 1: SWS Bartolo Well Field Area (Well 201W8 in the distance)
-------
San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Suburban OU Site Inspection Checklist
Photo 3: SWS 201W8 Discharge Line
U:07
mm*
Photo 4: SWS 201W9 Wellhead
7
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report, Suburban OUSite Inspection Checklist
Photo 5: Location of Abandoned SWS Well 201W2
-------
Appendix D: Interview Forms
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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Appendix D. Interview Forms
The following Interview Forms are provided in this appendix:
• Golden State Water Company (GSWC)
• City of Monterey Park (MP)
• San Gabriel Valley Water Company (SGVWC)
• Suburban Water Systems (SWS)
• Main San Gabriel Basin Watermaster (Watermaster)
• San Gabriel Basin Water Quality Authority (WQA)
• Rurban Homes Mutual Water Company (RHMWC)
Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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Five-Year Review Report for San Gabriel Valley Area 1 Superfund Site
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report Appendix C, Site Interview Forms
Five-Year Review Interview Record
Interviewee(s): Golden State Water Company
David Chang, Vice President, Environmental Quality
Email: dchang(®gswater.com
Telephone: 714-535-7711x218
Address: 1920 W. Corporate Way
Anaheim, CA 92801
Site Name
EPAOUs
Date of
Interview
Interview
Method
San Gabriel Valley Area 1
Superfund Site
South El Monte OU
2/27/13
Telephone
Interviewer
Contacts
Organization
Phone
Email
Address
Rachelle
Thompson
EPA Region 9
415-972-3962
Thompson. rachelle(S)epa.gov
75 Hawthorne Street, SFD-7-3
San Francisco, CA 94105
David Towell
CH2M HILL, EPA
contractor
213-228-8285
dtowell(S)ch2m.com
1000 Wilshire Blvd., Ste. 2100
Los Angeles, CA 90017-2457
Interview Questions
1. The Golden State Water Company (GSWC) operates wells SGI, SG2, and the respective treatment
facility as part of the South El Monte OU cooperative agreement. Beyond operation of these facilities,
does GSWC have a broader interest in the South El Monte OU?
Response: Yes, GSWC is in interested in how the South El Monte OU remedy is operating. They would
like to see regular updates on how the overall cleanup is progressing and suggest periodically reviewing
remedy performance compared to progress to assess if modifications are needed.
2. Do you believe that wells SGI and SG2 and the treatment facility, and more broadly, the South El
Monte OU remedy, are operating effectively and efficiently? Do you have any comments,
suggestions, or recommendations regarding the project's management or on EPA's role in the
project?
Response: The pumping rate from the SG2 continues to be restricted to 300 gpm because of the CDPH-
approved nitrate blending plan requirements. The blending plan also requires that SGI be operating for
SG2 to operate. So, if SGI goes down, the system is down. GSWC is more comfortable running the
treatment plant, now that SG2 is back online. Both of the wells are 50 to 60 years old and can be
expected to have ongoing maintenance concerns. Overall, the system is operating effectively now but the
age of the wells is a longer-term concern.
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report Appendix C, Site Interview Forms
3. What are your biggest near-term and/or longer-term concerns, if any, regarding GSWC's ability to
meet EPA's target pumping rates? Do you have any particular concerns about changing contaminant
concentrations or new contaminants affecting operation of SG1/SG2?
Response: As noted in the prior response, the biggest short-term and long-term concerns are about the
viability of the wells. The PCE/TCE concentrations have been stable are not of particular concern. GSWC
hopes that perchlorate concentrations remain low and that nitrate concentrations do not increase. There
are no other specific contaminants they are concerned about. However, new drinking water regulations
are always possible (e.g., hexavalent chromium) and could impact future operations.
4. Are you aware of any complaints or concerns from cities, neighbors, or other community members
regarding wells SGI, SG2, the treatment facilities, or the South El Monte OU?
Response: No, GSWC has not had any complaints at all related to the San Gabriel site or any other
aspects of the remedy. This includes during recent well rehabilitation and other treatment plant
modifications.
5. Do you feel well informed about the site activities and progress?
Response: Yes, GSWC feels well informed, primarily through participation in the quarterly meetings.
6. Is there anything else related to wells SGI, SG2, the treatment facilities, or the South El Monte OU
remedy as a whole that you would like to bring up?
Response: GSWC is concerned with what would happen if the SGI well fails. In addition, EPA's minimum
pumping targets for the SG1/SG2 wells are relatively high compared to the water demands in GSWC's San
Gabriel system which is fairly small. Achieving the pumping targets requires that GSWC reduce
production from other wells (i.e., Saxon). In addition, any maintenance or repairs needed at the SG1/SG2
wells or the associated treatment plant must be performed quickly to ensure target rates can be met.
Overall, GSWC operations staff feel constrained by having to meet the target rates.
GSWC_022713_SGV_AREA1_FYR_INTERVIEW_FINAL.DOCX
Page 2 of 2
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report Appendix C, Site Interview Forms
Five-Year Review Interview Record
Interviewee(s): City of Monterey Park
Address: 320 West Newmark Avenue
Monterey Park, CA 91754
Chris Arriola
Email: carriola(® monterevpark.ca.gov
Telephone: 626-307-1295
Site Name
EPA OU(s)
Date of
Interview
Interview
Method
San Gabriel Valley Area 1
Superfund Site
South El Monte OU
2/21/13
Telephone
Interviewer
Contacts
Organization
Phone
Email
Address
Rachelle
Thompson
EPA Region 9
415-972-3962
ThomDson.rachellefSJeDa.sov
75 Hawthorne Street, SFD-7-3
San Francisco, CA 94105
David Towell
CH2M HILL, EPA
contractor
213-228-8285
dtowell(S)ch2m.com
1000 Wilshire Blvd., Ste 2100
Los Angeles, CA 90017-2457
Interview Questions
1. The City of Monterey Park (the City) operates wells 5, 12, 15, and their respective treatment systems
as part of the South El Monte OU cooperative agreement. Beyond operation of these facilities, does
the City have a broader interest in the South El Monte OU?
Response: Yes, the City is very interested in everything that is happening in the South El Monte OU,
particularly activities and data upgradient of the City's production wells and information on remedy
performance from downgradient wells. The City appreciates that data that EPA shares and presents at
the quarterly South El Monte OU technical meetings.
2. Do you believe that Wells 5, 12, and 15 and their respective treatment facilities, and more broadly,
the South El Monte OU, are operating effectively and efficiently? Do you have any comments,
suggestions, or recommendations regarding the project's management or on EPA's role in the project?
Response: The City feels that generally, yes the wells, treatment facilities and South El Monte OU are
operating effectively. They have some concerns about the higher-than-expected PCE concentrations at
Well MP-15 and the presence of 1,4-dioxane. The City does not have any comments or recommendations
regarding overall project management or EPA's role.
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report Appendix C, Site Interview Forms
3. What are your biggest near-term and/or longer-term concerns, if any, regarding the City's ability to
meet EPA's target pumping rates? Do you have any particular concerns about changing contaminant
concentrations or new contaminants affecting operation of the remedy wells?
Response: Their biggest concern by far is the higher contaminant concentrations noted above that
impact performance. Further increases in PCE would impact air stripper performance and LGAC changeout
frequency. Further increases in 1,4-dioxane could result in wells having to be shut down because no 1,4-
dioxane treatment is available.
The City is proceeding with plans to consolidate all treatment to a centralized plant at the Delta facility
that will include UV/Ox treatment for 1,4-dioxane and an LGAC dual barrier. In addition to providing for
1,4-dioxane treatment, the City feels this will be a much more efficient system than their current set-up of
3 different plants and 3 different CDPH permits. The City needs a water rate increase to facilitate the
project. They are going through the Prop. 218 process and expect to take the increase to the public within
the next couple of months. The project is expected to cost from $7 to 8 million and in addition to the new
UV/Ox treatment unit would include replacement of their booster pumps and settling tanks and a back-up
generator for emergency power.
4. Are you aware of any complaints or concerns from cities, neighbors, or other community members
regarding Wells 5, 12, and 15, their respective treatment facilities, or the South El Monte OU?
Response: The City is not aware of any complaints or concerns related to the remedy facilities or the
South El Monte OU. They used to periodically get complaints regarding dust blowing off of the Delta
facility, but that issue went away once they paved it. He does not anticipate any major community issues,
even when they undertake construction of the new treatment facilities noted above.
5. Do you feel well informed about the site activities and progress?
Response: Yes, the City feels up-to-speed. The quarterly meetings are very informative and provide
updates on both EPA's efforts and issues being faced by the other two water purveyors.
6. Is there anything else related to Wells 5, 12, and 15 and their respective treatment facilities, or the
South El Monte OU remedy that you would like to bring up?
Response: The City does not have any other issues to bring up. They believe that the project is running
smoothly with all parties being very cooperative. There are good working relationships among the
stakeholders (water purveyors, state agencies and EPA).
MONTEREY_PARK_022113_SGV_AREA1_FYR_INTERVIEW_FINAL.DOC Page 2 of 2
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report Appendix C, Site Interview Forms
Five-Year Review Interview Record
Interviewee(s): San Gabriel Valley Water
Company
Address: 11142 Garvey Blvd,
El Monte, CA 91733
Frank LoGuidice, Vice President Engineering and Operations
Email: faloguidice(®sgvwater.com
Dan Arrighi, Vice President Water Quality and Planning
Email: darrighi(®sgvwater.com
Oscar Ramos, Water Quality Superintendent
Email: omramos(®sgvwater.com
Telephone: 626- 448-6183
Site Name
EPAOUs
Date of
Interview
Interview
Method
San Gabriel Valley Area 1
Superfund Site
South El Monte OU, Richwood OU
2/27/13
Telephone
Interviewer
Contacts
Organization
Phone
Email
Address
Rachelle Thompson
EPA Region 9
415-972-3962
Thompson. rachelle(S)epa.gov
75 Hawthorne Street, SFD-7-3
San Francisco, CA 94105
David Towell
CH2M HILL, EPA
contractor
213-228-8285
dtowell(S)ch2m.com
1000 Wilshire Blvd., 21st Floor
Los Angeles, CA 90017-2457
Interview Questions
1. The San Gabriel Valley Water Company (SGVWC) operates wells 8B, 8C, 8D, and Plant No. 8 as part of
the South El Monte OU cooperative agreement. Beyond operation of these facilities, does SGVWC
have a broader interest in the South El Monte OU?
Response: Yes, SGVWC has a direct broad interest in the South El Monte OU because of both their Plant
8 facility and their upcoming involvement in operating EPA's Whittier Narrows OU remedy. SGVWC also
operates the Plant G4 treatment facility. While not part of the South El Monte OU remedy, it is a vital
drinking water source for SGVWC.
2. Do you believe that wells 8B, 8C, 8D, and the treatment facility at Plant No. 8, and more broadly, the
South El Monte OU, are operating effectively and efficiently? Do you have any comments,
suggestions, or recommendations regarding the project's management or on EPA's role in the
project?
Response: SGVWC believes that their wells and treatment systems are operating effectively. Regarding
overall project management, SGVWC wants there to be specific acknowledgment that the minimum
pumping target rates for Plant 8 can be achieved through pumping any combination of the three remedy
wells 8B, 8C and 8D rather that the well-specific rates included in the cooperative agreement.
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San Gabriel Valley Area 1 Superfund Site
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3. What are your biggest near-term and/or longer-term concerns, if any, regarding SGVWC's ability to
meet EPA target pumping rates? Do you have any particular concerns about changing contaminant
concentrations or new contaminants affecting operation of the Plant 8 remedy wells?
Response: SGVWC is very concerned about the concentrations of perchlorate and 1,4-dioxane that are
present in some of the Plant 8 wells. They have not observed any increasing concentrations recently, but
the concentrations are very close to levels of concern. SGVWC has an on-the-shelf design for perchlorate
and has identified a footprint at Plant 8 for perchlorate treatment. They will finalize the design and
initiate construction if concentrations one half the Maximum Contaminant Level (MCL). CDPH has not yet
formally reviewed the designs.
SGVWC is also concerned with the levels of PCE because their AQMD permit for the Plant 8 air stripper
has an influent concentration limit of 100 ppb. There is also always the potential for MCLs, ALs, or NLs to
be lowered, for example the PCE MCL, which could impact performance.
4. Are you aware of any complaints or concerns from cities, neighbors, or other community members
regarding wells 8B, 8C, 8D, Plant No. 8 or the South El Monte OU?
Response: SGVWC has not had any complaints regarding the Plant 8 facility and is not aware of any
concerns from the neighbors or City. SGVWC maintains constant communication with the cities it purveys
water to.
5. Do you feel well informed about the site activities and progress?
Response: SGVWC feels reasonably well informed on project activities through the updates provided at
the quarterly meetings.
6. Is there anything else related to wells 8B, 8C, 8D, Plant No. 8 or the South El Monte OU remedy that
you would like to bring up?
Response: SGVWC has no immediate concerns. However, remedy wells at Plant 8 are old, so there is
uncertainty about their long-term viability. SGVWC has concerns about the long-term funding status of
the South El Monte OU remedy.
SGVWC_022713_SGV_AREA1_FYR_INTERVIEW_FINAL_REV1 .DOCX Page 2 of 3
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report Appendix C, Site Interview Forms
7. Once SGVWC purchased Richwood Mutual Water Company, how has SGVWC supplied water to the
former Richwood Mutual customers? For example, what are the current sources and the distribution
system through which Richwood Mutual's former customers receive their water? Has that changed
since 1999 when SGVWC originally assumed responsibility for supplying these customers?
Response: SGVWC acquired Richwood's water rights and connected all of Richwood's customers to
SGVWC's system individually through new service connections. The former Richwood customers are
primarily supplied water from SGVWC's Plants 1 and 2; however, because SGVWC's system is
interconnected the water could potentially come from almost any of the company's wells. This operation
has not changed since the customers were initially integrated.
SGVWC never took ownership of the Richwood supply wells, but did provide Richwood guidance
regarding the well destruction process and believes the wells were destroyed.
There are a number of small mutual water companies that continue to operate in the El Monte area.
SGVWC has emergency connections with all of them.
SGVWC also noted they would have no objection to EPA de-listing the Richwood OU.
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report Appendix C, Site Interview Forms
Five-Year Review Interview Record
Interviewee(s): Suburban Water Systems
Address: 1325 N. Grand Avenue, Suite 100
Covina, CA 91724-4044
Craig Gott, Vice President Engineering
Email: cgott(®swwc.com
Telephone: 626-543-2500
John Brettl, Quality Assurance Department
Email: JbrettiPswwc.com
Ken Reich, Quality Assurance Department
Email: kreich(®swwc.com
Kevin Hostert, Production Department
Email: khostert(®swwc.com
Josh Vaughn, Chief Operator 1, Quality Assurance
Department
Email: ivaughn(®swwc.com
Site Name
EPA OUs
Date of
Interview
Interview
Method
San Gabriel Valley Area 1
Superfund Site
Suburban OU
2/25/13
Telephone
Interviewer
Contacts
Organization
Phone
Email
Address
Rachelle
Thompson
EPA Region 9
415-972-3962
Thompson. rachelle(S)epa.gov
75 Hawthorne Street, SFD-7-3
San Francisco, CA 94105
David Towell
CH2M HILL, EPA
contractor
213-228-8285
dtowell(S)ch2m.com
1000 Wilshire Blvd., Ste 2100
Los Angeles, CA 90017-2457
Interview Questions
1. Suburban Water Systems operates the Bartolo Well Field, the primary component of EPA's Suburban
OU. Is Suburban Water Systems' interest in the overall San Gabriel Valley Area 1 Superfund Site (South
El Monte OU, Richwood OU and Suburban OU) limited to the operation of the Bartolo Well Field or
does it have a broader interest in the ongoing cleanup efforts?
Response: Suburban does not have an interest in operating remedy components or taking treated water
from any of the listed OUs. Suburban has had discussions with EPA regarding potential involvement in
the Whittier Narrows OU.
Suburban does have concerns regarding the presence of 1,4-dioxane in the Bartolo well field. 1,4-
Dioxane has been detected in all off the Bartolo wells at low concentrations. VOC concentrations have
been very low (1 ppb or less) at the Bartolo well field for a long time. If water quality conditions began to
change, Suburban may become more interested in the activities occurring at the OUs in San Gabriel Valley
Area 1.
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2. What was done regarding the closure of wells 201W2, 201W5, and 201W6? Were they destroyed or
abandoned?
Response: Wells 201W1 and 201W3 were destroyed in 2005. Wells 201W2 and 201W6 were destroyed
in 2008. Well 201W5 was destroyed in 2011.
3. Can you provide a map showing the locations of all nine wells (active and inactive) in the Bartolo well
field?
Response: Suburban will provide a map of the well field if EPA or CH2M HILL submits a more formal
request (on letterhead) for the information.
4. Historical documents show there was a concern regarding nitrate at the Bartolo well field in 1997.
Are you aware of any past or current issues related to nitrate levels at the Bartolo wells? Are you
concerned about increasing contaminant concentrations or new contaminants affecting Bartolo well
field pumping operations?
Response: Suburban is not aware of any past issues with nitrate levels at the Bartolo wells. They noted
that the Bartolo nitrate levels are very low.
5. Do you believe that EPA should be conducting any additional activities in the Suburban OU?
Response: No, Suburban does not believe any additional activities are warranted.
6. Are you aware of any complaints or concerns from cities, neighbors, or other community members
regarding the Bartolo Well Field or the Suburban OU?
Response: Suburban is not aware of any complaints.
7. Do you feel well informed about the site activities and progress?
Response: No, Suburban is not well informed with activities at the San Gabriel Valley Area 1 site.
However, they are actively involved in Area 2 (Baldwin Park OU).
8. Is there anything else related to the Bartolo Well Field, the treatment facilities, or the Suburban OU
remedy that you would like to bring up?
Response: No.
(As a follow-up question, EPA mentioned the possibility of de-listing the Suburban OU from the Superfund
site and asked Suburban's opinion of this. EPA also noted that if contaminant levels started increasing
again at the Bartolo wells, that the wells are located within the footprint of the Whittier Narrows OU and
could be evaluated through that OU.)
Suburban is fine with de-listing.
SUBURBAN_022513_SGV_AREA1_FYR_INTERVIEW_FINAL.DOCX
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report Appendix C, Site Interview Forms
Five-Year Review Interview Record
Interviewee(s): Main San Gabriel Basin
Watermaster
Address: 725 N. Azusa Avenue
Azusa, CA 91702
Tony Zampiello, Executive Director
Email: tonvz(®watermaster.org
Telephone: 626-815-1300
Steve Johnson, Stetson Engineers
stevei(® stetsonengineers.com
Telephone: 626-967-6202
Site Name
EPAOUs
Date of
Interview
Interview
Method
San Gabriel Valley Area 1
Superfund Site
South El Monte OU, Richwood OU,
Suburban OU
2/28/13
Telephone
Interviewer
Contacts
Organization
Phone
Email
Address
Rachelle Thompson
EPA Region 9
415-972-3962
Thompson. rachelle(S)epa.gov
75 Hawthorne Street
San Francisco, CA 94105
David Towell
CH2M HILL, EPA
contractor
213-228-8285
dtowell(S)ch2m.com
1000 Wilshire Blvd., 21st Floor
Los Angeles, CA 90017-2457
Interview Questions
1. Can you provide contact information for knowledgeable representatives of the Hemlock Mutual
Water Company and Rurban Mutual Water Company we could interview to learn about the status of
these water systems?
Response: Stetson/Watermaster do have contact information for Hemlock Mutual and Rurban Mutual
representatives that are knowledgeable about their systems. Both are very small operations.
Watermaster will send along the information that Stetson has compiled.
Note: The Watermaster send the requested information compiled by Stetson to EPA via email on 3/31/13.
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San Gabriel Valley Area 1 Superfund Site
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2. Can you provide operational information for the Hemlock and Rurban Mutual Water Companies,
including service area, approximate number of customers, recent pumping data and the status of any
operating treatment systems?
Response: Hemlock Mutual- The Hemlock wells no longer require treatment and the treatment system
has not been active for a long time. Hemlock started treating water from the North and South wells in
April 1986 and treated a total of 2,600 acre-feet. The peak concentrations of PCE were 52 ppb in the
North well and 210 ppb in the South well and these occurred in the late 1980s. In recent years, both wells
have been non-detect. They are sampled annually as part of the Title 22 monitoring conducted by
Watermaster.
Rurban Mutual- The Rurban wells were never equipped with treatment. Peak PCE concentrations were
16 ppb in 1980 at the North well and 24 ppb in 1981 at the South well. Both wells have been non-detect
in the recent annual Title 22 sampling events. There have not been any changes to Rurban Mutual
operations.
Watermaster believes that the Richwood wells were destroyed, but Stetson can verify this. The
treatment system has been removed.
3. Do you have any near-term and/or long-term concerns about the South El Monte, Suburban, or
Richwood OUs?
Response: The Watermaster has had a fairly limited role in the South El Monte OU, but may eventually
look more closely into the effectiveness of the remedies in the various OUs including South El Monte.
Watermaster typically becomes engaged in the remedies when a water purveyor plans either new wells
or a new treatment unit because of the Watermaster's Section 28 permit process. As part of the Section
28 process, Watermaster evaluates the potential impacts of a new well or new treatment unit.
Watermaster can also help in addressing surface water discharge issues which can arise when a new
contaminant is detected that requires installation and testing of new treatment units.
Recently, the Watermaster has provided some technical support to WQA for the Whitmore project. The
State Water Resources Control Board requested additional evaluation of the effectiveness of that project
as part of their approval for additional operating funds. Watermaster has concerns about a potential
source area east of the SEMW-09 well (which is upgradient of Plant 8). Concentrations have increased
considerably in SEMW-09. Watermaster does not have any concerns about the Richwood or Suburban
OUs.
4. Do you feel well informed about the site activities and progress?
Response: Watermaster feels fairly well informed through Stetson's attendance at the quarterly South El
Monte OU meetings. Watermaster staff may also start attending the South El Monte OU meetings. The
Watermaster is much more engaged in the Baldwin Park OU and Puente Valley OU remedies than in the
South El Monte OU. They expect that this will continue to be the case unless any of the water entities
raise concerns about South El Monte to the Watermaster.
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5. Is there anything else related to the South El Monte, Suburban, or Richwood OUs that you would like
to bring up?
Response: Watermaster does not have any other issues or concerns to bring up.
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report Appendix C, Site Interview Forms
Five-Year Review Interview Record
Interviewee(s): San Gabriel Basin Water Quality
Authority
Address: 1720 W. Cameron Ave., Suite 100
West Covina, CA 91790
Ken Manning
Email: Ken(®WQA.com
Telephone: 626-338-5555
Randy Schoellerman
Randv(® WQA.com
Telephone: 626-338-5555
Site Name
EPAOUs
Date of
Interview
Interview
Method
San Gabriel Valley Area 1
Superfund Site
South El Monte OU, Richwood OU, and
Suburban OU
3/15/13
Telephone
Interviewer
Contacts
Organization
Phone
Email
Address
Rachelle Thompson
EPA Region 9
415-972-3962
Thompson. rachelle(S)epa.gov
75 Hawthorne Street, SFD-7-3
San Francisco, CA 94105
David Towell
CH2M HILL, EPA
contractor
213-228-8285
dtowell(S)ch2m.com
1000 Wilshire Blvd., 21st Floor
Los Angeles, CA 90017-2457
Interview Questions
1. Do you believe the South El Monte OU cleanup is operating effectively and efficiently? Do you have
any comments, suggestions, or recommendations regarding the project's management or EPA's role
in the project?
Response: WQA believes that the South El Monte OU remedy is operating effectively as an interim
remedy. They do have concerns about 1,4-dioxane and want to make sure it is considered in the Final
ROD. DTSC has also been in contact with WQA about whether more PRPs could be identified for the
South El Monte OU. WQA is not aware of any additional PRPs, but will support DTSC's efforts.
WQA is okay with EPA's current role in the OU and feels that all of the stakeholders need to continue to
work together moving forward. WQA noted that data transfer should be more efficient and quicker in the
future.
2. Are you aware of any complaints or concerns from cities, neighbors, or other community members
regarding cleanup activities in the South El Monte OU?
Response: WQA is not aware of any concerns from local stakeholders regarding the South El Monte OU
cleanup. WQA did note that DTSC has expressed concerns about their ultimate role in the project and in
identifying more PRPs.
WQA_031515_SGV_AREA1_FYR_INTERVIEW_FINAL.DOCX
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report Appendix C, Site Interview Forms
3. Do you feel well informed about the site activities and progress? Are you familiar with the Richwood
and Suburban OUs?
Response: In general WQA feels well informed with activities and progress in the South El Monte OU.
They would like more frequent updates (beyond the quarterly meetings) when EPA is engaged in active
fieldwork.
WQA is only vaguely familiar with the Richwood and Suburban OUs and understands them to be inactive
OUs. They would endorse de-listing the two OUs and think that is an appropriate action.
4. Do you have any concerns regarding the administration of the South El Monte cooperative
agreement, either regarding the funding from EPA or the agreements with the water companies?
Response: WQA does not have any significant concerns with cooperative agreement administration at
this time and feels they are working smoothly with both EPA and the water purveyors. WQA to start the
process early on developing the next cooperative agreement scheduled for 2015.
5. Is there anything else related to the cleanup activities in the South El Monte OU that you would like to
bring up?
Response: WQA has had discussions with the water purveyors and the WQA Board about long-term
administration of the South El Monte OU and what funding options there may be beyond the existing
settlement funds and EPA's current commitments. DTSC also shares WQA's concerns about long-term
funding sources.
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report Appendix C, Site Interview Forms
Five-Year Review Interview Record
Interviewee(s): Rurban Mutual Water Company
Address: 5044 Cogswell Road
El Monte, CA 91732
Mike Cox
Email: iennvmikecox(®gmail.com
Telephone: 626-401-9103
Site Name
EPA OU(s)
Date of
Interview
Interview
Method
San Gabriel Valley Area 1
Superfund Site
Richwood OU
5/7/13
Telephone
Interviewer
Contacts
Organization
Phone
Email
Address
Rachelle
Thompson
EPA Region 9
415-972-3962
ThomDson.rachellefSJeDa.sov
75 Hawthorne Street, SFD-7-3
San Francisco, CA 94105
Alan Bradford
CH2M HILL, EPA
contractor
714-435-6297
alan.bradford(S)ch2m.com
6 Hutton Centre Drive, Ste. 700
Santa Ana, CA 92707
Interview Questions
1. Is the Rurban Mutual Water Company (Rurban) continuing to supply water? What area does it serve,
and approximately how many households/people does it supply water to?
Response: Yes, Rurban continues to supply water to an area in the northern portion of the City of El
Monte, formerly known as Norwood Village. Rurban supplies water to 300 homes, with an average of 4
persons per home or approximately 1,200 persons.
2. Besides providing its customers with water that meets drinking water standards, does Rurban Mutual
currently have an interest in the broader volatile organic compound (VOC) contamination and
associated cleanup activities in the general area?
Response: Yes, Rurban is aware of and interested in VOC contamination and cleanup activities in the San
Gabriel Valley. Rurban is in contact with the City of El Monte, who at Rurban's request samples their two
production wells once per year. Rurban also has another party conduct a second sampling event of their
production wells each year, for a total of two sampling events per year.
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San Gabriel Valley Area 1 Superfund Site
Five-Year Review Report Appendix C, Site Interview Forms
3. The 1987 ROD Amendment for the Richwood Operable Unit (OU) indicated that the GAC treatment
system for Rurban Mutual was never implemented because tetrachloroethene (PCE) and
tricholoroethene (TCE) concentrations detected in wells (01900120 and 01900121) declined to below
Action Levels. Since the 1987 ROD Amendment, have concentrations of PCE or TCE in Rurban wells
ever exceeded state or federal drinking water standards? Was a granular activated carbon (GAC)
treatment system ever installed?
Response: No, Rurban has not had detections of contaminants exceeding drinking water standards.
Rurban tests water samples for a full range of contaminants including PCE, TCE, hexavalent chromium,
perchlorate and nitrate. Rurban currently samples their two production wells twice per year. No, Rurban
never installed a GAC system.
4. Are you aware of any complaints from cities, neighbors, or other community members, regarding VOC
contamination or associated cleanup activities?
Response: Rurban received one complaint recently from a customer who reported their water tasted like
it had jet fuel in it. Rurban tested the water and no contaminants were detected. There are old gravel
pits surrounding the Rurban service area which are being backfilled because they are no longer used. The
customer who complained lives on the edge of Rurban's service area near one of the gravel pits. Rurban
believes the backfill material can get into the groundwater and may influence the taste of their
groundwater from time to time. Rurban monitors the gravel pit backfilling operations.
Rurban operates independently from other nearby water companies, such as Hemlock Mutual Water
Company, but does interact occasionally with the nearby water company representatives.
5. Is there anything else related to the VOC contamination or associated cleanup activities you would like
to bring up?
Response: No. Rurban is a small water system and believes their water is of good quality because their
wells are located between two river beds. Rurban monitors the data for the Key Well in Baldwin Park and
is aware of the Aerojet facility to the north in Azusa, CA.
6. Would Rurban have any objections to EPA de-listing the Richwood OU from Area 1 of the San Gabriel
Valley Superfund Site given that the VOC cleanup activities were implemented long ago and VOCs
have not been an issue for many years?
Response: Rurban has no opposition to EPA de-listing the Richwood OU.
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