United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R09-89/043
September 1989
Superfund
Record of Decision
Sacramento Army Depot, CA
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50272-101
| REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/ROD/R09-89/043
3. Redpiefrfe Acceeelon No.
4. Title and Subtitle
SUPERFUND RECORD OF DECISION
Sacramento Army Depot, CA
First Remedial Action
5. Report tot*
09/29/89
7. Author(e)
8. Performing Orgintarton Rept No.
9. Performing OrgelnliBtlon Neme end Addree*
ia ProlKVTuk/Woffc UnH No.
11. Contract(C) or Grint(G) No.
(C)
(G)
12. Sponsoring Orgmlutton Nun* end Addreee
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
13. Type of Report & Period Covered
800/000
14.
IS. Supplementary Nolee
16. Abtfrect (Limit: 200 worde)
The 485-acre Sacramento Army Depot (SAAD) site, 7 miles southeast of downtown Sacramento,
California, is surrounded by land zoned as commercial and light industrial property. SAAD
is an electronic maintenance and repair depot consisting of storage, maintenance, and
office facilities. Present operations include shelter repair, electro-optics equipment
I repair, metal plating, and treatment of metal plating wastes. From approximately 1947 to
L.972 paint sludges, oil, grease wood, trash, solvents and other industrial wastes were
purned and disposed of onsite in burn pits. SAAD has since removed most of the burned
(material from the burn pits. The burn pits were subsequently covered with soil and
[revegetated. Ground water samples, collected by SAAD from 1981 to 1984, indicated that
several chemical compounds were present at levels above drinking water standards in two
areas. The primary contaminants of concern affecting the ground water are VOCs including
TCE and PCE.
The selected remedial action for this interim remedy includes ground water pumping and
treatment, using ultraviolet light/chemical oxidation followed by discharge to the regional
treatment plant and industrial reuse of the treated ground water. The estimated capital
cost of the remedy is $1,764,000 with an estimated annual O&M cost of $264,000.
17. Document Anelyelo e, Deecrlptore
Record of Decision - Sacramento Army Depot,
First Remedial Action
Contaminated Medium: gw
Key Contaminants: VOCs (TCE, PCE)
b. Mentfflere/Open-Ended Ti
CA
c. COSAT1 FWd/Oroup
1*. Security Ctaee (Thte Report)
None
20. Security Cteee (TMe Page)
None
21. No.ofP«oee
22
22. Price
(SeeANSI-ZU.il)
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-35)
Department of Commerce
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RECORD OF DECISION FOR ON-SITE GROUND WATER REMEDIATION
AT THE SACRAMENTO ARMY DEPOT
1. DECLARATION
Site Name and Location:
* Sacramento Army Depot (SAAD)
(On-Site ground water Contamination)
Sacramento, California 95813-5052.
Statement of Basis and Purpose:
The basis of this Record of Decision (ROD) is:
* The Administrative Record for the Site which contains:
* The Operable Unit Feasibility Study (OUFS) which contains site
investigation data.
* The Proposed Plan (PP).
* The Responsiveness Summary, which summarizes the public
comments on the OUFS and the PP.
The purpose of this ROD is:
* To set forth the interim remedial action to be conducted at
SAAD to remedy ground water contamination associated with
the former burn pits located in the southwest corner of the
Depot. This is the first of several potential remedial actions
addressing soil and ground water contamination which may be
conducted at SAAD. Subsequent ROD'S will address other
potential threats posed by the site, both on and off-site.
Summary:
* The U.S. Environmental Protection Agency, Region IX (EPA DC)
and State of California (DHS) concur on the selected interim
remedial action.
* This interim remedial action is consistent with the
Comprehensive Environmental Response Compensation and
Liability Act as amended by the Superfund Amendments and
Reauthorization Act of 1986 (CERCLA/SARA), to the extent
practicable, the National Contingency Plan (NCP), the
National Environmental Policy Act (NEPA) and the California
Environmental Quality Act (CEQA).
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RECORD OF DECISION FOR ON-SITE GROUND WATER REMEDIATION
AT THE SACRAMENTO ARMY DEPOT, cont
Assessment of Site: Ground water samples collected by SAAD from 1981 to
1989 indicate that several chemical compounds are present, primarily
trichloroethene, tetrachloroethene, 1,2-dichloroethane, and cis/trans-1,2-
dichloroethene. These compounds have been detected at levels above
drinking water standards in the ground water. An area known as the former
burn pits located in the southwest corner of the Depot is considered the likely
source of the organic compounds found in ground water.
Description of Selected Remedy:
The major components of the selected remedy include:
* Installation of seven ground water extraction wells down
gradient from the former burn pits.
* Extraction of contaminated ground water on-site at
approximately 350 gallons per minute.
* Treatment of contaminated ground water by ultraviolet
light/chemical oxidation without toxic air emissions or creation
of residual hazardous waste.
* Discharge of treated ground water to the Regional
Treatment Plant pending completion of beneficial reuse
analysis.
* Completion of construction and start-up of the extraction and
treatment system within the next twelve months.
* Restoration of the contaminated ground water on-site to current
drinking water standards within approximately ten to fifteen
years of system operations.
Declaration: This interim remedial action is protective of human health and
the environment, complies with Federal and State applicable or relevant and
appropriate requirements directly associated with this action and is cost-
effective. This action utilizes permanent solutions and alternative treatment
technologies to the maximum extent practicable. The statutory preferences
for remedies that employ treatment that reduces toxicity, mobility, or volume
as a principal element have been addressed and are encompassed by this
response action.
IT IS SO AGREED:
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RECORD OF DECISION FOR ON-SITE GROUND WATER REMEDIATION
AT THE SACRAMENTO ARMY DEPOT, cont
FOR THE U.S. DEPARTMENT OF THE ARMY:
Date Lewis D. Walker
Deputy for Environmental, Safety,
and Occupational Health
Office of the Assistant Secretary
of the Army (I&L)
3fbuL?—.
Date John F. Donahoe
; Colonel, SC
/ Commander, Sacramento Army Depot
FOR THE STATE OF CALIFORNIA:
'f>.
Date Alex Cunningham f
Chief Deputy Director
Toxic Substances Control Program
California Department of Health
Services
FOR THE U.S. ENVIRONMENTAL PROTECTION AGENCY:
Date Daniel W. McGovern
Regional Administrator
United States Environmental
Protection Agency, Region IX
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RECORD OF DECISION FOR ON-SITE GROUND WATER REMEDIATION
AT THE SACRAMENTO ARMY DEPOT, cont
2. DECISION SUMMARY
Site Name, Location, and Description
Site Name: Sacramento Army Depot (SAAD) (On-Site Ground water
Contamination)
Location: 8350 Fruitridge Road, Sacramento, California, 95813-5052.
Description: SAAD is an electronics maintenance and repair depot consisting
of storage, maintenance, and office facilities. Present operations at SAAD
include shelter repair, electro-optics equipment repair, metal plating, and
treatment of metal plating wastes.
SAAD is located in the center of Sacramento County, approximately 7 miles
southeast of downtown Sacramento. Encompassing approximately 485 acres
(approximately 2 square kilometers), SAAD is immediately surrounded on all
sides by land zoned as commercial/light industrial property.
Site History and Enforcement Actions
The former burn pits (See Figure 1), the suspected source of the ground water
contamination, were used beginning between 1947 -1953 and used through
approximately 1972 to dispose of wastes by burning including paint sludges,
oil, grease, wood, trash, solvents and other industrial wastes. SAAD
excavated the bum pits when incineration activities were stopped around
1972. Based upon a recent soil gas investigation of the burn pits, it appears
that most of the burned material was removed from the burn pits. Currently,
the burn pits are covered with soil and have considerable vegetative growth.
No environmental enforcement actions have been taken against SAAD. In
December 1988, the Army, EPA, and DHS entered into a Federal Facility
Agreement governing the conduct of the Installation Restoration Program on
SAAD.
Highlights of Community Participation
Public notice was placed in two of the local daily newspapers of general
circulation (Sacramento Bee, Sacramento Union) beginning 15 July 1989
announcing the availability of the OUFS and the PP for review and comment.
These documents are part of the SAAD Administrative Record and are
available at the following local repositories: SAAD Visitor Control Center,
and at the California State University> Sacramento, Library. The OUFS and PP
were also available for public review at the Sacramento office of DHS, and at
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RECORD OF DECISION FOR ON-SITE GROUND WATER REMEDIATION
AT THE SACRAMENTO ARMY DEPOT, cont.
EPA headquarters in San Francisco. DHS has also noticed the contiguous
property owners to the Depot.
Public review and comment was invited for a period of thirty-five days
from 22 July 1989 to 26 August 1989. No written or telephone comments
were received.
A public meeting on the PP was held on 8 August 1989 at Will C. Wood
Middle School, which is located near the Depot. The meeting was attended by
three, members of the public from the local SAAD area and responses are
summarized in Section 3.
The Depot environmental contamination and management program
have also been the subject of numerous newspaper, radio, and television
articles over the past five years. Additionally, two previous public meetings
have been held in 1987 and 1988 to discuss the Depot Installation Restoration
Program.
Scope and Role of Operable Unit
An operable unit is an interim measure that prevents , minimizes, stabilizes,
mitigates or eliminates the release of a hazardous substance, consistent with
or until a permanent remedy is developed. The Operable Unit proposed by
SAAD will contain, extract and treat on-site contaminated ground water
associated with the former burn pits located in the southwest corner of the
installation. The ground water cleanup is intended to reduce potential health
risks from exposure to contaminated ground water by treating the water to
meet Federal and State drinking water standards. Ground water extraction
wells will extract contaminated ground water at approximately 350 gallons per
minute down-gradient from the former burn pits and the contaminants will
be destroyed as the contaminated ground water passes through an ultraviolet
light/chemical oxidation treatment system. The treated water will be used for
industrial processes once evaluation of potential uses has been completed and
an agreement with an industrial facility has been concluded. Construction of
the treatment system will be completed within the next twelve months. The
overall quality of the ground water will be restored to meet current drinking
water standards after ten to fifteen years of operation.
This is the first of several potential remedial actions addressing soil and
ground water contamination which may be conducted at SAAD. Subsequent
ROD's will address other potential threats posed by the site, both on and off-
site.
Site Characteristics
SAAD has a topography that is relatively flat with ground surface elevations
ranging from 36 to 42 feet above mean sea level. SAAD is situated within the
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RECORD OF DECISION FOR ON-SITE GROUND WATER REMEDIATION
AT THE SACRAMENTO ARMY DEPOT, cont.
Morrison Creek drainage basin with Morrison Creek being the only surface
water located near the depot. Until it was diverted around the southern
border of the site by the U.S. Army Corps of Engineers in 1945, Morrison
Creek bisected SAAD at the center of the eastern boundary and flowed across
the site toward the west. Morrison Creek discharges into the two overflow
basins of the Sacramento and American Rivers and eventually empties into
the Sacramento River. Mean annual precipitation at the site is approximately
17 inches.
Depth to ground water beneath the site is approximately 78 feet. The ground
water gradient is approximately 1.5 feet per thousand feet and the flow
direction is to the south-southwest.
Subsurface geologic data from SAAD indicates a number of small sand
channels exist in the upper 140 feet which are difficult to trace. This upper
section has been grouped into two zones, "A" and "B", based on the relative
permeabilities of the lithologies encountered. Beneath the "B" zone at a
depth of about 140 feet, a silty zone occurs with a thickness varying from 8 to
14 feet. This zone appears to be a relatively continuous confining layer. This
zone overlies the "C" zone, which has an approximate thickness of 20 to 25
feet. The "C" zone is underlain by a clayey silt zone approximately 8 to 15 feet
thick. The "C" zone overlies the T>" zone, which is encountered at
approximately 200 feet below ground surface.
A review of aerial photographs by EPA showed several areas where past
industrial practices may have created contamination. Ground water samples
collected by SAAD from 1981 to 1988 indicated that several chemical
compounds were present, primarily trichloroethene, tetrachloroethene, 1,2-
dichloroethane, and cis/trans-l,2-dichloroethene. These compounds have
been detected at levels above drinking water standards in the "A" and "B"
zones (See Figure 2).
Summary of Site Risks
A variety of carcinogenic and noncarcinogenic chemicals have been
identified in on-site and off-site monitoring wells. From this initial list of
contaminants nine indicator chemicals were selected based on factors such as
ground water concentration levels, potential toxicity and environmental fate
and persistence. The indicator chemicals and a quantitative summary of the
baseline public health evaluation bases upon EPA ARAR's (See Figure 3).
Evaluation of the site-specific conditions in the 2 mile radius study area
indicates that the ground water transport is the only release mechanism
applicable to the OUFS analysis. Ground water concentrations of the
chemicals were estimated using off-site ground water monitoring data and
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RECORD OF DECISION FOR ON-SITE GROUND WATER REMEDIATION
AT THE SACRAMENTO ARMY DEPOT, cont
ground water modeling. Monitoring data provides a look at the present day
concentration near the potential exposure point.
Modeled ground water concentrations were predicted at two primary
exposure points:
1. The nearest business and nearest residence located down-gradient of
the former burn pits, and
2. All identified down-gradient municipal drinking water wells located
within the study area.
The nearest business/residence scenario represents the maximum
exposed individual (MEI) present in the study area. The potential
carcinogenic risks posed by these contaminants are significantly higher for the
MEI than for the individuals consuming water from the municipal well
sources. A 95% upper-bound confidence interval lifetime cancer risk of 4.4E-
04 was calculated for the MEI based upon the lifetime consumption of
drinking water at the highest concentrations modeled at the respective
nearest business/residence drinking water well. In other words, the MEI (a
fictitious person who lives next to SAAD and and drinks 2 liters per day of
120 part per billion tricholorethene contaminated ground water for 70 years)
would have a 440 in a million increased chance of contracting cancer. No
significant risk to the public or the environment would remain, once clean-
up goals are attained.
Description of Alternatives and Summary of Comparative Analysis of
Alternatives
Fourteen clean-up options for the SAAD site were considered in the On-Site
Ground water Operable Unit Feasibility Study (OUFS). The six most feasible
alternatives were evaluated with respect to nine evaluation criteria, which
are summarized below. Number five was selected as the preferred
alternative.
1. Short-term effectiveness - Addresses the period of time needed to
complete the remedy, and to minimize any adverse impact on human health
and the environment that may be posed during the construction and
implementation period, until the clean-up goals are achieved.
2. Long-term Effectiveness and Permanence - Refers to the ability of a
remedy to maintain reliable protection of human health and the
environment over time, once cleanup goals have been met.
3. Reduction of Toxicity, Mobility and Volume (TMV) Through
Treatment - Refers to the anticipated ability of a remedy to reduce the toxicity,
mobility, and volume of the hazardous components present at the site.
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RECORD OF DECISION FOR ON-SITE GROUND WATER REMEDIATION
AT THE SACRAMENTO ARMY DEPOT. conL
4. Implementability - Refers to the technical and administrative feasibility
of a remedy, including the availability of materials and services needed to
carry out a particular option.
5. Cost - Evaluates the estimated capital and operation and maintenance
costs of each alternative.
6. Overall Protection of Human Health and the Environment - Addresses
whether or not a remedy provides adequate protection and describes how
risks posed through each pathway are eliminated, reduced or controlled
through treatment, engineering controls, or institutional controls.
7. Compliance with Applicable or Relevant and Appropriate
Requirements (ARARs) - Addresses whether or not a remedy will meet all
ARARs of federal and state environmental statutes and/or provide grounds
for invoking a waiver.
8. State Acceptance - Indicates whether, based on its review of the
information, the state concurs with, opposes, or has no comment on the
preferred alternative.
9. Community Acceptance - Indicates whether community concerns are
addressed by the remedy and whether or not the community has a preference
for a remedy. Although public comment is an important part of the final
decision, EPA is compelled by law to balance community concerns with all of
the previously mentioned criteria.
After evaluating options for technical feasibility, implementability, and cost, a
detailed analysis was performed on the six most feasible alternatives. Each of
the six alternatives is briefly described below:
1. No Action - The no-action alternative was used as a baseline to
evaluate other potential alternatives. Under the no action alternative, no
control or remediation of the affected ground water would occur. However, a
limited ground water monitoring program would monitor for the presence of
the organic compounds and track their migration from the SAAD site.
Immediate implementation of this alternative is possible.
Estimated Construction Cost: $51,000
Estimated Annual Maintenance Costs: $25,000
2. Ground Water Extraction. Treatment by Air Stripping, and Surface
Discharge - Under this alternative, wells extract the affected ground water,
contamination is removed from the extracted ground water by air stripping,
and treated ground water is discharged to Morrison Creek. Compounds
8
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RECORD OF DECISION FOR ON-SITE GROUND WATER REMEDIATION
AT THE SACRAMENTO ARMY DEPOT. conL
removed from the ground water by the air stripper would be transferred to
the air without further treatment. Other alternatives using air stripping with
air emission control were considered, however, were eliminated during
preliminary screening due to excessive costs. This alternative also includes
monitoring of ground water, surface water, treatment plant influent, and
discharge water over the term of the operation to assess the effectiveness of
extraction and treatment, and compliance with discharge requirements.
Construction could be completed within approximately 12 months. The
overall quality of ground water in the aquifer would be restored to meet
current drinking water standards after 10 to 15 years of operation.
Estimated Construction Cost: $1,170,000
Estimated Annual Maintenance Costs: $242,000
3. Ground Water Extraction. Treatment by Air Stripping, and Industrial
Reuse - This alternative is similar to Alternative 2 above, except that treated
water would be discharged to a local industrial facility for reuse instead of to
Morrison Creek. Other construction details and monitoring requirements
will be the same. The overall quality of ground water in the aquifer would be
restored to meet current drinking water standards after 10 to 15 years of
operation.
Estimated Construction Cost: $1,345,000
Estimated Annual Maintenance Costs: $207,000
4. Ground Water Extraction. Treatment with Ultraviolet/Chemical
Oxidation, and Surface Discharge - This alternative is similar to Alternative 2
except that ultraviolet light/chemical oxidation is used for treatment of
ground water, not air stripping. The organic contamination in the extracted
water would be destroyed as the water passes through the treatment process,
without releases to the air or creation of residual wastes. Tests conducted
using this alternative technology demonstrated a high degree of effectiveness
in destroying SAAD organic contaminants. After two minutes exposure to
ultraviolet light/chemical oxidation, the organic contaminants were rendered
non-detect using EPA analytical methodologies. Other construction details
and monitoring requirements will be the same. Construction of this
alternative could be completed in approximately 12 months. The overall
quality of ground water in the aquifer would be restored to meet current
drinking water standards after 10 to 15 years of operation.
Estimated Construction Cost: $1,530,000
Estimated Annual Maintenance Costs: $298,000
5. Ground Water Extraction. Treatment with Ultraviolet/Chemical
Oxidation, and Industrial Reuse - This alternative is similar to Alternative 4
above, except the treated water would be discharged to a local industrial
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RECORD OF DECISION FOR ON-SITE GROUND WATER REMEDIATION
AT THE SACRAMENTO ARMY DEPOT, cont
facility, not to surface water. Other construction details and monitoring
requirements will be the same. Construction of this alternative could be
completed within about 12 months. The overall quality of ground water in
the aquifer would be restored to meet current drinking water standards after
10 to 15 years of operation.
Estimated Construction Cost: $1,764,000
Estimated Annual Maintenance Costs: $264,000
6. Ground Water Extraction and Discharge to the Sacramento Regional
Wastewater Treatment Plant - Under this alternative wells would extract
ground water, which would then be discharged without treatment to the
Sacramento Regional Wastewater Treatment Plant (regional treatment plant).
The organic compounds in the water would be diluted in the sewer system
and ultimately released to the air in the treatment plant, and discharged to
the Sacramento River. This alternative also includes monitoring of ground
water and discharge water to assess the effectiveness of the extraction process,
and compliance with discharge requirements. Construction of the alternative
could be completed in about 12 months. The quality of ground water in the
aquifer would be restored to meet current drinking water standards after 10 to
15 years of operation.
Estimated Construction Cost: $1,316,000
Estimated Annual Maintenance Costs: $197,000
Selection of the Preferred Alternative
A summary of the alternatives is presented in Figure 4 and 5. All of the final
alternatives except Alternative 1 (No Action) considered use ground water
extraction to control migration and remove contaminated ground water. The
main differences are: 1) the treatment technology, if any, to be used to treat
contaminated ground water prior to discharge, and 2) the discharge option to
be used.
All of the alternatives considered except Alternative 1 provide protection of
human health and the environment and meet the current ARARs.
However, only alternatives that use ultraviolet light/chemical oxidation
result in permanent destruction of the contaminants, unlike air stripping or
discharge to the regional treatment plant. The potential health risk associated
with operation of a ultraviolet light/chemical oxidation system is much
lower than for air stripping because the organic compounds are not released
to the air. Therefore, the most desirable alternative would use ultraviolet
light/chemical oxidation for ground water treatment.
10
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RECORD OF DECISION FOR ON-SITE GROUND WATER REMEDIATION
AT THE SACRAMENTO ARMY DEPOT, cont
Three disposal options for the extracted ground water were evaluated: 1)
surface water discharge to Morrison Creek, 2) industrial reuse, and 3)
discharge to the regional treatment plant. Although no significant public
health or environmental impacts are expected to result from the disposal
options, alternatives that entail industrial reuse are preferred because the
water would serve beneficial purposes. More time may be needed to
implement industrial reuse because a long-term agreement with the
industrial user would be necessary. Negotiating a water reuse agreement
could delay implementation of the alternative; however, a delay will be
avoided by temporarily discharging the treated ground water to the regional
treatment plant.
The public comment period has closed and no changes have been suggested.
Therefore, based on the information presented in the Proposed Plan and the
OUFS report, Alternative 5 (ground water extraction, treatment with
ultraviolet light /chemical oxidation, and eventual industrial reuse) has been
selected as the preferred alternative.
In summary, the preferred alternative is believed to provide the best balance
among alternatives relative to the evaluation criteria used to weigh the
potential options. Based on the information available at this time, the Army,
the EPA IX and the DHS believe the preferred alternative will be protective of
human health and the environment, will attain current ARARs, would be
cost-effective, and will use permanent solutions and alternative treatment
technologies to the maximum extent practicable.
Statutory Determinations
* The U.S. Environmental Protection Agency, Region IX (EPA IX)
and State of California (DHS) concur on the selected Interim
Remedial Action.
* This interim remedial action is consistent with the
Comprehensive Environmental Response Compensation and
Liability Act as amended by the Superfund Amendments and
Reauthorization Act of 1986 (CERCLA/SARA), to the extent
practicable, the National Contingency Plan (NCP), the National
Environmental Policy Act (NEPA), and the California
Environmental Quality Act (CEQA).
* The preferred alternative represents the most economic and
environmentally acceptable alternative since the contaminants
are destroyed on site without generating additional toxic waste,
and without generating toxic air contaminants.
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RECORD OF DECISION FOR ON-SITE GROUND WATER REMEDIATION
AT THE SACRAMENTO ARMY DEPOT, cont.
* Construction .of the treatment system will be completed within
next twelve months following approval of the ROD. The
overall quality of the ground water will be restored to meet
current drinking water standards (see Figure 2 for chemical
specific ARARs) after ten to fifteen years of operation.
* This interim remedial action is protective of human health and
the environment, complies with Federal and State applicable or
relevant and appropriate requirements directly associated with
this action and is cost-effective. This action utilizes permanent
solutions and alternative treatment technologies to the
maximum extent practicable. The statutory preferences for
remedies that employ treatment that reduces toxicity, mobility,
or volume as a principal element have been addressed and are
encompassed by this response action.
3. RESPONSIVENESS SUMMARY
The Depot environmental contamination and management program have
also been the subject of numerous newspaper, radio, and television articles
over the past five years. Additionally, two previous public meetings have
been held in 1987 and 1988 to discuss the Depot Installation Restoration
Program.
Public notice was placed in the local community daily newspapers
(Sacramento Bee, Sacramento Union) starting on 15 July 1989 announcing the
availability of the OUFS and the PP for review and comment. These
documents are part of the SAAD Administrative Record and are available at
the following local repositories: SAAD Visitor Control Center, and at the
California State University, Sacramento, Library. The OUFS and PP were
available at the Sacramento office of DHS, and EPA headquarters in San
Francisco. DHS has also noticed the contiguous property owners to the Depot.
Public review and comment was invited for a period of thirty-five days
from 22 July 1989 to 26 August 1989. No written or telephone comments were
received.
A public meeting on the PP was held on 8 August 1989 at Will C. Wood
Middle School, which is located near the Depot. The meeting was attended by
three members of the public from the local SAAD area and a summary of
questions and answers include:
A. Why wasn't the public informed of this meeting and this situation?
The public was informed of the meeting via the public notices in
the local newspaper and the notices to contiguous property owners. The
Depot environmental contamination has been the subject of numerous
newspaper, radio, and television articles over the past five years.
Additionally, two previous public meetings in 1987 and 1988 have been held
12
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RECORD OF DECISION FOR ON-SITE GROUND WATER REMEDIATION
AT THE SACRAMENTO ARMY DEPOT, cont
to present and discuss the Depot Installation Restoration Program. The Depot
intends to expand its public information process to include additional public
meetings, fact sheets, and updating its mailing list.
B. When did the Depot first know that it had a problem?
The original Records Assessment and limited Remedial
Investigation were conducted between 1979 -1981. Although they revealed
soil and ground water contamination on the Depot, the Investigation Report
concluded that it was unlikely that the ground water contamination would
migrate beyond Depot boundaries and that the ground water contamination
could be coming from an off-Depot source. The Depot initiated additional
actions in 1983 when the Depot suspected that it could be a source for
contamination discovered off-site and immediately beyond Depot boundaries.
C Why has it taken the Army so long to take any action on this problem?
One of the most critical factors in arriving at a solution to any
environmental contamination problem is the identification of the size and
extent of the problem. This work was begun in 1983 and continues to this
day. Once the identification of the size and extent of the problem were
established, the alternatives to remediating the problem were explored. The
geohydrology of the Depot is extremely complex. Over seventy ground water
wells have been installed and additional actions, such as supplying bottled
water to one private business and removing underground tanks, have
occurred. Additionally, the technical, administrative, and legal process
required to comply with applicable federal, state, and local environmental
laws and regulations governing remedial actions is very detailed, complex,
and time consuming.
D. What are the ground water contaminants?
The ground water contaminants are primarily organic
contaminants and include; trichloroethene, tetrachloroethene, 1,2-
dichloroethane, and cis/trans-l,2-dichloroethene.
E. What is the major contaminant?
Trichloroethene represents the major [concentration of
contamination] contaminant in the ground water with a maximum
concentration of one hundred and twenty parts per billion (micrograms per
liter). The state and federal action level for trichloroethene is five parts per
billion. Drinking water action levels are established to protect public health.
For the contaminant trichloroethene in drinking water, the action level is
based upon a risk of contracting cancer of one-in-one million. That means
that a person exposed by drinking 2 liters of water per day for 70 years
contaminated with 5 parts per billion of trichloroethene would have a one-
in-one million chance of contracting cancer as a result of drinking the water.
F. Are the Depot employees drinking the contaminated water?
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RECORD OF DECISION FOR ON-SITE GROUND WATER REMEDIATION
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Depot employees do not drink the contaminated ground water
because the City of Sacramento supplies the Depot with drinking water.
G. Who is drinking the contaminated water?
To the best of our knowledge there is no one drinking the
contaminated water. There are two private businesses (just beyond the Depot
southwest boundary) that are using contaminated water which exceeds
drinking water standards for industrial purposes only.
H. What is the health risk from drinking the contaminated ground water?
To the best of our knowledge no one drinks the contaminated
ground water. However, health risks are established by calculating the long
term exposure to the contaminants as if someone were drinking the water. In
this instance, for example, the health risk for contracting cancer to an adult
individual weighing seventy kilograms consuming two liters of this
contaminated ground water per day over their 70 year lifespan would be 4.4E-
04 (440 in a million). By comparison, the acceptable risk factor established by
EPA and DHS is E-06 (1 in a million). On this basis, the decision to treat the
contaminated ground water was made.
I. How far has the contaminated ground water spread?
Contamination has been found south-west beyond the Depot
boundaries in an area within (approximately) 100 yards south of Elder Creek
Road, and approximately one-quarter mile west of the Depot (See Figure 6).
J. How long will it take to clean up?
The current estimate is that it will take approximately ten to
fifteen years of extraction and treatment to restore the ground water to
drinking water standards.
K. Is the Depot using the latest technology to clean-up the contamination?
While the ultraviolet light/chemical oxidation technology has
been used widely for the disinfection of drinking water, it's application to
cleaning up organic contaminated ground water is a fairly new, but proven
technology. EPA and DHS are looking very closely at the Depot project as a
possible alternative which may be applicable for wide-spread use. This
technology represents the "best" technology for dealing with the Depot
contamination in that it permanently destroys contaminants, leaves no
hazardous residues and does not generate toxic air contaminants.
L What does this technology do to the contamination in the water?
The ultraviolet light/chemical oxidation uses a destructive
chemical treatment process that oxidizes the contaminants to innocuous
compounds. The oxidation process oxidizes the organic contaminants in the
presence of ultraviolet light. The products of the reaction are carbon dioxide,
water, and a minute amount of chlorine which remains dissolved in the
14
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RECORD OF DECISION FOR ON-SITE GROUND WATER REMEDIATION
AT THE SACRAMENTO ARMY DEPOT, cont
water. The chemical treatment process has the advantage of destroying the
contaminants and producing no toxic by-products.
M. What is the Depot going to do with the cleaned-up water?
The Depot will be discharging the treated ground water directly
to the Sacramento Regional Treatment Plant on a temporary basis until
alternate beneficial reuses (currently industrial reuses) can be studied. Studies
of alternative reuses are underway at this time.
N. Why is the Depot dumping the contamination into Morrison Creek?
The Depot does not discharge contamination into Morrison
Creek. The only Depot discharge into Morrison Creek is the storm drain
system.
15
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SITE MAP
FruHridoo Rood
FACIUTY^OUNDARY*
A
N
100 400 1000
8c«U In FMt
FIGURE 1
-------
GROUNDWATER CONTAMINANTS. DESIGN CONCENTRATIONS. AND
TREATMENT OBJECTIVES
Contaminant
chloroform
carbon tetrachloride
trichlorocthene
tetrachloroethene
1,1-dichloroe thane
1,1-dichloroethene
1,1,1-trichloroethane
trans-l,2-dichloroetbene
1,2-dichloroethane
bromodichloromethane
Average
Concentration
(ug/1)
4.9
0.4
642
103
0.5
03
0.1
8.6
0.9
02
Design
Concentration
(ug/1)
7.4
0.6
963
15.5
0.8
03
0.2
12.9
1.4
03
Treatment
Objective
(ug/1)
1001
5
5
4
5
6
200
16
1
1001
TOTAL
Total trihalomethanes.
90.7
136.4
FEDERAL AND STATE CONTAMINANT ACTION LEVELS
Contaminant
chloroform
carbon tetrachloride
trichloroethene
tetrachloroethene
1,1-dichloroethane
1,1-dichloroethene
1,1,1-trichloroethane
trans-l,2-dlchloroethene
1,2-dichloroetbane
Federal
MCL
(ug/1)
1002
5
5
_
5
7
200
—
5
State
SAL3
(ug/1)
5
5
4
20
6
200
16
1
MCL «• Maximum Contaminant Level.
2 MCL is for total tribalomethanes.
3 SAL=State Action Level which existed during OUFS development.
FIGURE 2
-------
SUMART OF ttt IASELINE FOIL 1C HEALTH tVAUMUM
SlUt MM)
Crowd W»ttr CUM
Indicator ChaailcaUt 1. Arsenic. 2. tarlua. 1. Cadalua. «. tartan Tatractilarlda. S. CMarofe
6. 1.2-OtcMoroatliana, 7. 1.1-OlcMoroatJiant. 8. Tatraehlaraathana.
9. frlchleretthcnt.
Requlraaanta/Cr 1 terla
Nuaan
Exposure
Point
Naaraat
•uslnesa/
3 Naaraat
2 Residence
50
m
UJ
Naxlaua
Ispactad
Nunlclpal
Drinking
Watar
Walt
Nuabtr
af Paapla
Exposure Patent I ally
Patlmsy Exposed CMpered
1. Ingest Ion 1 1. EPA NCL
2. EPA NO.
2. Inhalation/ 3. EPA NO.
Daraal 4. EPA NCL
Absorption 3. N/A
A. EPA NO.
7. EPA NCL
6. N/A
9. EPA NCL
1. Ingattlen 14.905 1. EPA NCL
2. EPA NCL
2. Inhalation/ 3. EPA NCL
Darwl 4. EPA NCL
Absorption : S. N/A
6. EPA NCL
7. EPA NCL
a. N/A
O.EPA NCL
Standard
Concentration
Ratio
4.8C-05
2.8E-OS
2.3E-04
4.8E-01
•-
7.BE-01
2.36-01
-
5.06*01
<2.0E-09
<1.0E-10
<1.0E-08
4.BE-07
-•
1.3E-0&
3.4E-07
* •
3.AE-05
Potential Carcinogenic Rltk
Weight af
Evidence Chronic
Rltk Ooalnant for Don. Naiard
Eatlaata CKMlcal die*. Index
A.9E-07 9.3E-OI
..
..
7.5E-04
1.11-0* Oilarofans 12
1.«E-OS
5.7E-05
1.4E-04 PCE 12
1.1 t-0* Ttt 12
4.4E-11 1.5E-07
•-
--
1.«E-11
3.4E-11
3.4E-11
1.3E-10 1.1-OCE C
5.36-12
1.3E-10 PCE 12
Roncarclnoganlc Nlsk
tavarlly
Rating Subchronlc Significant '<
Ooailnant for Ooa>. Naiard Sources af
Oiaalcal Chea. Inde* Uncertainty Caiaiantt,
PCX 7.10 N/A Ground
Water
Nodal Ing
CPr for
PCE
Carbon 10.10 N/A Creund
Tit. Witer
Model Im
-------
SUMMARY OF DETAILED ANALYSIS
OF GROUND WATER OUFS ALTERNATIVES
Assessment Criteria
Alternative No. 1 - No Action
Alternative No. 2 - Containment
by Pumping, Air Stripping,
Surface Discharge
Alternative No. 3 - Containment
by Pumping, Air Stripping,
Industrial Reuse
Description
Short-Term
Effectiveness
Effectiveness and
Permanence
3
2 Reduction in
50 Toricitv. Mobility.
Implementabilitv
Compliance with
ARARs
Overall Protection of
Hitman
Environment
Cost
No mitigating measures.
Continued ground water
monitoring.
No significant risk from
monitoring.
Long-term health risks
remain from ingestion of
contaminated water from
offsite production wells
No treatment used.
No technical impediments to
implementation. Regulatory
concurrence not probable.
Does not comply with ARARs.
Does not provide protection.
No mitigation of primary
exposure pathway.
Capital
Annual
Present Worth
Economic Life
$ 51,000
$ 25,000
$288,000
30 years
Install extraction well system; Pump
and treat using air stripping; Discharge
to Morrison Creek; Ground water
and performance monitoring.
Low risk during construction.
No significant risk to public Of
environment would remain, once
cleanup goals are attained.
The organic compounds are transferred
to the air, but not destroyed unless
vapor-phase carbon is used.
Technologies used are readily available.
About 12 months needed for
construction.
Complies with ARARs, but does not meet
statutory preference for treatment.
No significant health risk during
construction and operation, except for
air emission. No significant risk remains
once cleanup goals are attained.
Capital
Annual
Present Worth
Economic Life
$1,170,000
$ 242,000
$3,449,000
,30 years
Install extraction well system; Pump
and treat using air stripping; Discharge
to local industrial facility; Ground water
and performance monitoring.
Low risk during construction.
No significant risk to public or
environment would remain, once
cleanup goals are attained.
The organic compounds are transferred
to the air, but not destroyed unless
vapor-phase carbon is used.
Technologies used are readily available.
About 12 months needed for construction.
Negotiation with industrial user could delay
implementation unless interim discharge to
SRWTP is used.
Complies with ARARs, but does not meet
statutory preference for treatment.
No significant health risk during
construction and operation, except for air
emission. No significant risk remains once
cleanup goals are attained.
Capital
Annual
Present Worth
Economic Life
$1345,000
$ 207,000
$3,299,000
30 years
-------
SUMMARY OF DETAILED ANALYSIS
OF GROUND WATER OUFS ALTERNATIVES
(CONTINUED)
Assessment Criteria
Alternative No. 4 - Containment
by Pumping, UV
Chemical Oxidation,
Surface Discharge
Alternative No. 5 - Containment
by Pumping. UV
Chemical Oxidation,
Industrial Reuse
Alternative No. 6 - Containment
by Pumping, SRWTP Discharge
1
8
Description
Short-Term
Effectiveness
Long-Tcrm
Effectiveness
Permanence
Reduction in
Toricitv. Mobility.
and Volume
Im olementabilitv
Compliance with
ARARs
Overall Protection
pf Human,
and the
Environment
Cost
Install attraction well system. Pump
and treat using UV
oxidation technology. Discharge
to Morrison Creek. Ground water
and performance monitoring.
Low risk during construction.
No significant risk to public
or environment would remain.
Technology destroys volatile
organic compounds without
formation of residual by-products.
Only two vendors offer technology
used, but they both have operating
systems at other sites. About 12
months needed for construction.
Complies with ARARs.
No significant health risk during
construction and operation.
No fjgnificant risk remains
once cleanup goals are attained.
Capital
Annual
Present Worth
Economic Life
$1,530,000
S 298,000
$4341,000
30 years
Install extraction well system
Pump and treat using UV
chemical oxidation technology.
Discharge to local industrial facility.
Ground water and performance monitoring.
Low risk during construction
No significant ruk to public or environment
would remain, once cleanup goals are attained.
Technology destroys volatile
organic compounds without
formation of residual by-products.
Only two vendors offer technology used
but they both have operating systems at
other sites. About 12 months needed for
construction. Negotiation with industrial
user could delay implementation unless interim
discharge to SRWTP used.
Complies with ARARs.
No significant health risk during
construction and operation.
No significant risk remains once
cleanup goals are attained.
Capital
Annual
Present Worth
Economic Life
$1,764,000
$ 264,000
$4,250,000
30 years
Install extraction well system.
Pump and discharge untreated water to
sewer routed to SRWTP. Ground
water and discharge monitoring.
Low risk during construction.
No significant risk to public or
environment would remain, once
cleanup goals are attained.
Compounds are either removed during pure
oxygen activated sludge process or levels
reduced by dilution. No destruction
of organics achieved.
Easily implemented within 6 to 12 months.
SRWTP has agreed to accept water.
Complies with ARARs, but does not meet
statutory preference for treatment
No significant health risk during
construction and operation. No significant
risk remains once cleanup goals are attained.
Capital
Annual
Present Worth
Economic Life
$1316,000
$ 197,000
$3,177,000
30 years
-------
APPROXIMATE CONTAMINANT PLUME BOUNDARIES
(Southwest Corner of SAAD)
ormer Oxid ition Lagoo
MM
Door Craok Rood
Approximate Plume Area
APPROXIMATE SCALE
I INCH-403FT.
FIGURE 6
-------
SACRAMENTO ARMY DEPOT
FEDERAL FACILITY AGREEMENT
ADMINISTRATIVE RECORD
INDEX OF DOCUMENTS
01 Sacramento Army Depot (SAAD) Federal Facility Agreement (FFA)
02 Proposed Plan for on-site Ground Water Remediation at the Sacramento Army
Depot
03 Onsite Ground Water Operable Unit Feasibility Study (OUFS)
\
04 Public Health Evaluation - Sacramento Army Depot - Phase II OUFS - Ground
Water Treatment System
05 Listing of CERCLA response Selection Guidance Documents Consulted for Pro-
posed Grpound Water OUFS
July 27,1989
06 Notice of Availability of Proposed Plan; and Notice of Intent to Adopt A Negative
Declaration
July 31,1989
FIGURE?
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