PB94-964506
EPA/ROD/R09-94/110
July 1994
EPA Superfund
Record of Decision:
Castle Air Force Base
(O.U. 2) CA
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FINAL
RECORD OF DECISION
FOR
OPERABLE UNIT NO. 2
CASTLE AIR FORCE BASE
COUNTY, CALIFORNIA
NOVEMBER 1993
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m.
IV.
TABIE OF CDNnNfS
TABLES AND FIGURES. . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 . . . . . 0 . . . . . . . . . . . . . . . . . . . . . . .. ii
DECLARATION FOR 1HE RECORD OF DEOSION .......................,. 0 . . . . . . 0 . . . .
DECISION SlJl\1l\1ARY . . . . . . . . . . . . . . . . . . . . . . . 0 . . . 0 . 0 0 . . . . 0 . . 0 . . . 0 . . 0 . . . . . . . 0 . . . . .
1
4
I.
no
SI1E NAME, LOCATION AND DESCRIPTION. .. . .. .. . 0 . . . . .. .. .. .. . . . o. . . . . .. . .
4
SITE InSTORY AND ENFORCEMENT ACIIVITIES.. 0 . . . . . . . . . . . . . . . . . 0 . . . . . . . . .. 11
HIGHLIGHrS OF COMMUNITY INVOLVEMENT. . .. . .. . . . .. . .. . .. .. .. .. . . .. . .. .. 13
v.
VI.
SCOPE AND ROLE OF TIlE OPERABLE UNIT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 .. 14
SUMMARY OF OU-2 INVESTIGATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 . . . . . .. 15
VITo
S~Y OF OU-2 RISKS """"""""""""""""" 0 . . . 0 . . . . . . . . . 22
QESCRIPnON OF ALlERNATIVES .. . . . . .. . . . . .. .. 0 . . . . . .. 0 0 .. . . . . . 0 . , .. 0 . 0 .. 30
VITI. SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES 0 . . . . . . . . . . . . . . 0 0 0 . .. .38
IX
X
SELE~~Y.. ... "0"""" ...... ... 0.. ... o' 0"'0""'0'" 0 0"'" 45
SI'A1UI'ORY DETERMINATIONS. .. . .. . .. . .. . .. .. 0 .. ... .. . . . . .. 0 . 0 . . . . . .. ." .;Vr'lE.
APPENDIX A:. ADMINIS1RATIVE RECORD FILE INDEX
APPENDIX B: RESPONSIVENESS SUMMARY
i
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TABLES AND FIGURES
TABLES
Table 1. SUMMARY OF VOC CONTAMINATION IN GROUND WA1ER IN WALLACE ROAD
AREA [[[ ;'. 11
Table 2. SUMMARY OF VOC CONTAMINATION IN GROUND WA1ER IN DA4 AREA. . . . . . . . .. 13
Table 3. VOC, 1PH,ANDMEI'ALSANALYnCALPRaTOCOL............................ 16
Table 3-A Federally or State-listed Species Potentially Occmring in the Region of Influence of Castle
Am..... ...........,........ .........,....... ...,.. ...,.. ..., .....,. . . 25
Table 4. SUMMARY OF COMPARATIVE ANALYSIS. . . . . . . . . . . . . . . . . . . . : . . . . . . . . . . . . . .. 50
Table 5-A APPUCABLE OR RELEVANT AND APPROPRIAlE FEDERAL REQUIREMENTS FOR
OU-2 .. . . . . . . . . . ". . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . :. . . . . . . 56
Table 5-B. APPUCABLE OR RELEVANT AND APPROPRIAlE CALIFORNIA REQUIREMENTS
FOR OU-2 [[[ 58
Table 5-C. GROUND WA1ER DISCHARGE lREATMENT STANDARDS. . . . . . . . . . . . . . . . . . . . .. 60
Table 6. RESULTS OF QUARTERLY GROUND WATER SAMPLING PROGRAM SUMMARY OF
TCE CONCENIRATIONS AT OD-2 ....................................,...... 61
Table 7. TCE RESULTS OF PRIVAlE WElLS IN WALLACE ROAD AREA . . . . . . . . . . . . . . . . . .. 63
FIGURES
Figure 1. OPERABLE UNIT NO.2 AREA OF CONTAMINATION. . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Figure 2. SUBSURFACE GEOLOGIClHYDROOEOLOGIC UNITS ......................,.... 9
Figure 3. SAMPLING LOCATIONS FOR OU NO.2. . . . . . . . . . . . . . . . . . . . . . . ... . . . . . . . . . . . -. ".' 20
Figure 4. SHALLOW HYDROSIRATIGRAPHIC ZONE GROUNDWAlER MO}.ITJ'()R WELL TCE
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DECLARATION FOR TIlE RECORD OF DECISION
SITE NAME AND LOCATION
Castle Air Force Base
Operable Unit No.2
Mem:d County, California
STATEMENT OF BASIS AND PURPOSE
. .
This Record of Decision (ROD) presents the remedial action selected for Castle Am, Operable Unit
NO.2 (OU-2), in Merced County, Califomia. OU-2 is defined as the contaminated ground water under the area
on Base iefened to as Dischaxge Area No.4 (DA-4) and the contiguous area off-Base v.here contamination from
Castle Am has migrated, in the vicinity of Wallace Road (Figure I), including all ground water along the .
interim OU-I/OU-2 boundary in Figure 1, which is not remediated by interim OU-l. The OU-2 system will be
designed to remediate degraded ground water that is not 1aterally covered by the interim OU-l system
This remedial action was chosen in accordance with the Comprehensive Fnvironmental Response,
Compensation and Liability Act of 1980 (CERCLA), as amended by the Superfimd Amendment.; and
Reauthoriza1ion Act of 1986 (SARA) (42 U.S.c. Section %O1~., and, to the extent pI3dicable, the National
Oil and Hazardous Substances PollutiOn Contingency Plan (NCP: 40 C.F.R Part 300). The attIr.hed
Administrative Record Index (A~r.hment A) identifies the docmnents upon v.hich the decision is based.
ASSESSMENT OF OU-2
If the actual or 1hreatened releases of hazardous substances for OU-2 are not addressed by impJeI\'IP.I1ting
the remedial response action selected in this ROD, OU-2 may present an Unminent and substantial endangerment
to public hea1tb, welfi1re and/or the enviromnent. Although a grotmd water removal action is underway in the
area of OU-2, it is not known to what extent contamination bas been controlled.
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DESCRIPTION OF 1HE SELECI'ED ,REMEDY
EP A, the U. S. Air Force, and the State of California, have selected Alternative n as the remedy for
Castle AFB, OU-2. The selected remedy consists of
..
1) Design, construction and operation of a grmmd water extIaction and treatment system to treat
extracted ground water with a packed tower air stripping method and caIbon treatment of air stripper off-gases to
levels that meet eftluent limits set forth in this ROD, and
2)
DischaIge by injection of treated grmmd water to the same aquifer from which it was extracted,
and
3) Ground water monitoring to demonstrate that the extIaction system is effectively capturing the
VOC contaminant plmne, attainment of the cleanup standards established for OU-2, and compliance with all
ARARs.
Implementation of this remedy will prevent the spread of ground water contamination and reduce the
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principal risk of human exposure to cOntaminated ground water. The ground water extraction and treatment
system will operate until ~ cleanup standards are achieved throughout the area defined as OU-2. The OU-2
extractionltreatment/disposal system will be designed to compliment the hydraulic influences of interim OU-l and
neaIby wells. Additional1y,the OU-2 remedial design shall remediate any ground water crnmnn1n:rt1on at its
southem boundaIy not covered by the interim OU-l remedial system.
STAlUTORY DEIERMINAll0NS
The selected remedy is protective of hwnan health and the environment, complies with FedeIal and State
requirements that are legally applicable or relevant and appropriate for the remedial action and is cost-effective.
This remedy employs pennanent solutions and a1temative treatment teclm.ologi.es to the maximum extent
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pI3Cticable, and satisfies the statutory preference for remedies that employ treatment to reduce toxicity, mobility,
or volmne as a primaIy element. A five-year review will be conducted to detennine the degree of mitigation
achieved through remediation and the amount of contamination remaining in the ground water.
~~~
FeliCIa Marcus J- .
Regional Administrator
U.S. EPA, ~on 9
11.11.. .tJ3
Dare
Alan P. Babbitt
Dare
Deputy for Hazardous Materials and Waste
Deputy Assistant Secretmy of the Air Force
(Environment, Safety and Occupational Health)
. Val Siebal
Regional Administrator
CaIifomia EP A
. .
Department of Toxic Substances Control
Region 1
Date
. 3
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DECISION SUMMARY
This decision smnmary provides an oveIView of the enviroJunental concems posed by OU-2. It also
includes a description of the remedial alternatives considered in the Castle Am RIJFS for OU-2 (Janumy 1992)
and the analysis of these alternatives when compared to criteria set forth in the National Contingency Plan
(NCP). This Decision SUIIDIlalY explains the mtionale for the selection of .A1temative IT and how the selected !
remedy satisfies the statutoIy requirements of CERCLA.
I.
SfIE NAME, LOCATION AND DESCRIPTION
A.
Site Name and Location
Castle Air Force Base
Operable Unit No.2
Merced County, California
B.
OU-2 Description
Operable Unit No.2 (OU-2), is located both on Castle AFB and in an unincorporated portion of Merced
Cowrty outside the city of Atwater, California. Ground water c:cmtamination underlies an area that is on-Base
and known as Discharge Area No.4 (DA-4) and a contiguous area off-Base (Wallace Road). The westwaId
. ,
migration of volatile OIgaDic compounds (V0Cs) in the ground water has proceeded beneath Wallace Road and
has been detected near the intersection ofWa1lace Road and Santa Fe Drive (FIgUre 1).
Seventeen volatile oIganic compounds (fables 1 and 2) have been detected in the ground water in the
area of OU-2. Of these 17 detected VOCS, ten were detennined to be present at levels that pose health risks.
Following Region 9 Risk Assessment Guidance, chemicals that were detected in fewer than 5 percent of the
analyzed samples were eliminated from. consideration in the quantitative risk assessment. The ten rem:rining
chemicals to be considered in the risk assessment are listed in Section VI.
Trichloroethylene (ICE) is the most prevalent and mobile contaminant, and is therefore determined to
be an indicator chemical. The risk assessment contained in the RI/FS for OU-2 identifies TCE as the major
CODIributor to health risks. The VOC chemicals moo will be remedied in OU-2 are trichloroethylene (fCE);
tetrachloroethylene (PCE), and benzene. While same lower health risk will remain due to remaining residual
contamllmtion from. the VOCS, reducing the level of C(1t11Mnin:rtion ofTCE, PCB and benzene to Maximum
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, Contaminant Levels (MCLs) willl~r risks to an acceptable range' of l.OE-4 to l.OE -6. The concentrations of
all VOCS will similarly be reduced by the remedial action.
OU-2 is the second grmmd water operable unit at Castle AFB. The contamination in OU-2 is a
combination of grmmd water degradation associated with sources in the main base sector and DA-4. OU-I and
OU-2 are areas designated by the parties. Once grmmd water contamination moves into an area, grmmd water
remediation will be perfonned under that operable unit. The ROD for interim OU- 1 was Dnaliz.ed in August
1991 and the remedial system for interim OU-l is currently under construction. Ultimately, the Comprehensive
Base-wi~e RI!FS ROD will address any soils cnntAA1irurtion and augment, as necessary, the ground water
remedies associated with operable unit Nos. 1 and 2.
c.
Land and Water Use
Land use within a two-mile radius of OU-2 is primarily agricultuml. Crops grown in the area consist
mostly of almonds, peaches, and grapes. Several small dairies and a laIge chicken fann are located to the east.
Open pasture lands are located to the north and east. Residential areas are located primarily west of OU-2 and
. .
include Base housing, trailer paIks, recently-constIUCted residential suburban housing and nua1 fimn residences.
Land use along Wallace Road is nrixed residential and agricu1tural (i.e., 0ICbards). Land use on the Base
includes a mixture of industrial and light-industrial fucilities, as well as militaIy offices and housing.
According to the RI/FS for OU-2 (Janumy 1992), approximately nine wells used for domestic and for
agricultural purposes have been impacted by the VOC ground water contAA1ination. An additional six wells in
the immediate vicinity could be impacted by OU-2 VOC contamination if remedial action were not taken. This
infonnation was confumed during the field activities completed in accordance with the "OU-2 Conceptual Design
Support Technical Memorandmn" ( October 1993), and the data collected from routine sampling of domestic
wells in the OU-2 area..
As part of a nation-wide militaIy cut-back, Castle AFB is cmrently scbeduI~ to close in September
1995.
D.
Regional Topography
. The Base is located in Merced County, California in the east central part of the San Joaquin Valley.
Neighboring conmnmities .include Atwater, located to the immediate west, Wmton, and Merced, ,located
approximately 5 miles south of the Base. .
The San Joaquin Valley fonns the southem half of the Great Valley Geommphic Province of Califomia.
This province is csppJUN.tuately 400 miles long and averages about 40 miles in width. It is bounded by the Siena
Nevada range to the east, the Coastal Range to the west, and is drained by the San Joaquin River. This river
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N
"No Scale"
-?- ~ TeE plume bcundatrbased on
Tee Met. (5.0~)
(Ouiried wtIefe I1nC1I1UI)
OtJ.2Pbne
Man TeE PluM (OU.')
Operable Unit 2
Castle Air Force Base
OU-2 Location Map
Figure
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..,.".".".-.,
1
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flows from the southeast to the Sacramento-San Joaquin Delta region, vmich lies between the Central Valley and
the San Francisco Bay.
The Base is located about halfway between the Merced River and Black Rascal Creek, two southwest-
flowing tributaries of the San Joaquin River. The valley floor in the vicinity of the Base area slopes gently to
the west-southwest. Natural drainage is to the southwest; however, surfuce flow patterns are locally controlled
by a system of drainage and irrigation canals. .
The total relief across the Base is approximately -35 feet, rangjDg from 200 feet above mean sea level
. .
(MSL). ~ the northwestern comer to 165 feet MSL at the southem comer. Relief within the Base boundaries is
essentially flat.
E.
GeologylHydrology
Geoloo:v
The eastern. San Joaquin Valley of Central Califomia is underlain by a basement complex composed of
metamcnphic and granitic~. In the vicinity of Castle AFB, the basement is overlain by a 1Iiick sequence of
sed1mentaty deposits of Tertiary/Quatemmy age (Figure 2).
Consolidated sedimentaIy units overlie the basement complex and have a minimum combined thickness
of over 700 feet. These consolidated mrits include, from oldest to youngest, the lone, Valley Springs and
Mehrten Fonnations.
Unconsolidated sedUnents overlie these fonnations from an elevation of approximately 450 feet below
MSL to an elevation of 165 feet above MSL. Beneath Castle AFB, the unconsolidated mrits include the Laguna,
Turlock Lake, RiveIbank, and Mxlesto Fonnations. Recent smficial dune deposits, which attain a maximmn
thickness of approximately 10 feet, occur at the ground surfuce. .
Nature and Occurrence of Grmmdwater
The coarser-gmined unconsolidated ~P.TIt~ (i.e., sands and gravels) underlying Castle AFB CODtain
miter that is tapped for water-supply pmposes. Three mIter-bearing units have been identified in the
unconsolidated sediments underlying Castle AFB, as shown in Figure 2. These units have been infonnally
desi81':rted as the sballow, confined and deep aquifers, respectively.
An aquitard sepanUes the sballow aquifer from the oonfinine aquifer. The aquitard is primarily
composed offine-gmined sediments (i.e., silts and clays) that are i1rterbedded with water-bearing sands and
gravels. Because these mterbedded coarse-grained materials provide a somce of water supply, the aquitard is .
also known as the "subshaIlowaquifer."
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Shallow Aauifer
The saturated portion of the Riverbank and Modesto Fonnations comprise the shallow aquifer, a
hydrogeologic unit which has been locally developed for irrigation and domestic uses. The shallow aquifer is
unconfined, and extends ftom the water table (at a depth of approximately 60 feet below the ground smfuce) to a
depth of approximately 100 feet.
Interbedded sands, gravels and silts with minor clay are cbaracteristic of the shallow aquifer, with the
.
exception of the lower IO-to-20 feet, which is primarily composed of gravel. The portion of the shallow aquifer
. above the basal gravel is knov.n as the "upper' shallow aquifer, while the basal gravel is referred to as the
''lower'' shallow aquifer.
Overdraft of wells completed in the shallow aquifer has resulted in a gradual decline in water table
levels in the vicinity of Castle AFB. When Merced Inigation District (MID) Well No.8, located off-base
approximately 2 miles south ofDA-4, was installed in the 1920's, the water table was encountered less than 10
feet below the ground surfiIce. The cmrent depth of the water table, as measured in the well, is approximately
50 feet. 1pe saturated thickness of the shallow aquifer has thus decreased about 40 feet in the last 70 years.
Aauitard ("Subshallow Aauifer")
A marl<.ed change in grain size OCCW'S beneath the basal gravel of the shallow aquifer at a depth of
approximately 100 feet below the ground surface. Predominantly fine~ sediments (i.e., silts and clays)
beneath the gravel marl<. the top of the Turlock Lake Fonnation. The upper Turlock Lake Fonnation comprises
the aquitard between the shallow and confined aquifers. The aquitard is approximately 165 feet thick, extending
from a depth of about 100 feet to 265 feet below the ground surface.
Sand and gravel lenses occur in the aquitard that contain water. Wells completed in these lenticular
zones supply water for both domestic and numicipal use, as well as for irrigation. Due to the presence of these
lenticular water-bearing zones, the aquitard is also known as the "subshallowaquifer." The aquitard also serves
as the C.(JI1iin;1\f unit for the underlying confined aquifer.
Confined Aauifer
In the vicinity of Castle AFB, the confined aquifer is comprised of the coarser-grained lower Turlock
Lake Fonnation. The confined aquifer extends from a depth of approximately 265 feet to 350 feet (Weston,
1988) and is the most extensively developed aquifer in the area. The confined aquifer supplies water to the
facilities on Castle AFB as well as to off-Base housing units. h also supplies water for irrigation purposes.
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Figure 2
SUBSURFACE GEOLOGIC AND HYDROGEOLOGIC UNITS
CASTLE AIR FORCE BASE OU-2
x'w
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o
CM
T
1
6
o
CVJ
o
in
C\J
o
o
^3
^^
A
O
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I
0
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GEOLOGIC
AGE
Reecn
•
Quaternary
1
o JS
£
GEOLOGIC UNIT
Dune Sands
Modesto and
Riverbank Formations
*
§L
§•
Turlock Lake Formation
§»
Laguna "Formation
Mehrten Formation
Valley Springs Formation
lone Formation
Basement Complex
HYDROGEOLOGIC
UNIT
Vadose "Unsaturated" Zone
M
water table
Shallow °PPer
Ac>uffer . lower
AquitarbV
"Subshallow
Aquifer"
Confined
Aquifer
Deep
Aquifer
(not to scale)
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Wells completed in the confined aquifer yield an average of approximately 1,900 gallons per minute
(gpm) and range upward to 4,450 gprn. Based on aquifer test data for Base Production Well No. PW-2, the
transmissivity of the confined aquifer was calculated to be 51,000 gallons per day per foot [(gpc:I/ft), Castle AFB,
PreliminaIy Site Characterization Report, June 1990]. Storativity was calculated to be approximately 0.0001.
Deeo Aauifer
. The deep aquifer occurs in the upper part of the Mehrten FODDation. The top of the deep aquifer is
approximately 650 feet below the ground surfuce. The actual vertical extent of the deep aquifer is unknown.
However, the groundwater is knO"Ml to become too saline below a depth of 1,200 feet to be used for a pot2ble
water supply or for irrigation purposes.
As discussed in the description of the subsmface geology for Castle Am and vicinity, the Mehrten
Fonnation consists of consolidated sedimentary depOsits including claystone, siltstone, sandstone, and
conglomerate. .1he deep aquifer supplies most of the water used at the Base and its off-Base housing units.
Well yields range from about 1,320 to 2,100 gprn.
Groundwater Movement
The regional direction of groundwater flow in the eastem San Joaquin Valley is to the west-southwest.
The primaIy source of natural recharge to the aquifers underlying the eastern San Joaquin Valley is stann nmoff
that infiltrates the Mehrten Fonnation and younger lDlconsolidated sedimeuts which crop out to the east.
Recharge from direct precipitation on the valley floor is limited by a vet)' high evapotranspimtion rate.
Infiltration of precipitation on the valley floor is also inhibited by the presence af hardpan layers (caliche) in
many of the valley soil profiles.
A seconda1y source of recbaIge in the region is percolation from irrigation. In the eastern San Joaquin
Valley, sources of irrigation water are primarily surfuce water reservoirs funned by damming streams in the
Siena Nevada foothills during the growing season. Water from these sources is conveyed to the valley floor
through natural and mamnade channels.
Under natural conditions, groundwater flows to the San Joaquin River and its major tributaries,
dischaiging as seepage to surfuce streams and marshes. Pumping of municipal. irrigation and Base production
wells are major groundwater dischaIge zones that locally may exert consideIable influence on the direction of
groundwater flow. The vertical component of groundwater flow is downwards and is influenced by ptnnping
groundwater from the deeper aquifers.
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u.
SITE HISTORY AND ENFORCEMENT ACTIVITIES
Wallace Road Area
In 1978, following the sampling of several on-Base production wells, the Air Force identified TCE
contamination in the ground water beneath the Base. In 1980, the Air Force and the Merced County Health
Department began a well sampling program to assess potential impacts of contaminants on aquifers serving the
local area wells. Figure 3 shows the locations of priv.ate and Air Force wells. One of the two areas where off-
Base wells were found to be affected by TCE contamination is tbe Wallace Road Area, between Santa Fe Drive.
and the western boundary of the Base. Table 1 presents both a summary of the range of concentrations of the
VOCs detected in ground water samples collected from wells in the Wallace Road area and their corresponding
Federal and State Maximum Contaminant Levels (MCL's).
Table 1. SUIfllARY OF vec CONTAMINATION IN GROUND WATER IN WALLACE ROAD AREA
UtilI
CCJo1POUNO CONCENTRAT ION FEO'MCL STATE'MCL
T~fchloroethvlene (TCE) NO to 310 5 5 .
Benzene NO to 12 5 1
Xylenes NO to 4.4 1000 1750
Toluene NO to 3.8 1000. u.
Ethyl benzene NO to 1.3 700 680
Olbromochloropropene (OICP) . NO to 0.09 0.2 0.2
Chloromethene NO to 5.8 u- u.
Chlorobcnzene NO to 1.1 100 30
1.2'Olchlorobenzene. NO to 0.1 600 u.
..
Methylene chloride NO to 4.4 5 u.
1.2-0ichloropropene NO to 0.6 5 5
Note: NO" not detected.
... .. no MCL.
The Air Force initiated a ground water removal action in the area of OU-2 in 1991. The perfonnance
record of this removal action (e.g., total TCE removed, water treated, levels of TCE in surrounding monitoring
wells and capture zone analysis) will be included in the design of OU-2.
11
. £O'd VOO'ON 9S:0t
£6'Ot I\ON
0£V~-9~L-60~-t:l31
'8~~ 3l1S~) A3)/S3) £f
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Discharge Area NO.4
A smmnary of the nmge of each VOC parameter detected in ground water samples collected from wells
at DA-4 is presented in. Table 2, also presented are the C01Tesponding Federnl and State MCL's (i.e. for
infonnational purposes).
DA-4 encompasses the liquid oxygen (LOX) fucility (Buildings 1314 and 1316). The 12.5-ton LOX
plant genernted liquid oxygen until it was discon1Dmed in 1959-1960. Building 1314 served as a toolshed and
Builcfu:1g 1316 contained the liquid oxygen tanks. Curreotly, Building 1314 contains the office that handles
liquid oxygen procurement from an outside contractor.
The process of producing liquid oxygen from air at the LOX plant required all parts that were touched
or taken apart to be thoroughly cleaned with TCE. If parts were not properly cleaned, pressurizt:d vessels had
the potential to explode. To peIfonn such extensive clemring, fonner Base personnel stated TCE was poured into
55-gallon drums each month so that parts could be bathed in laxge quantities of the solvent. Spent TCE was
thereafter disposed of into a concrete sump acljacent to the LOX plant. A concrete sump with drainage holes at
the ~ is located on the northwest side of the slab that once served as the foundation of the LOX plant.
Investigative efforts have revealed that acid (less than 1 %) was used to clean the drains at the LOX
plant. The acid dwnped into the drains caused the teITa cotta pipes to become brittle. During replacement of the
pipeline from Building 1309 to Building 1200, soils in the area of the LOX plant had the same citrus smell as
the acid and caused a mild irritation to skin. It is possible that this pipeline provided an additional mechanism
for TCE to be released.
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Table 2. SUMMARY OF VOC CONTAMINATION IN GROUND WATER. IN DA-4 AREA
1L9/l
COMPOUND CONCENTRATION FED-MCL STATE-MCL
Trichloroethylene (TCE) ND to 5,600 5 5
Ch loroform NO to 12 100 ---
Chloromethane NO to 0.5 --- ---
Freon 112 NO to 0.7 --- ---
"Tetrachloroethylene (PCE) NO to 8.3 5 5
1 1 2-trichloroethane (TCA) ND to 1.2 5 ---
cis-1,2-dichloroethylene ND to 2.3 70 6
Bromodichloromethane NO to 0.5 100 ---
Xylenes ND to 4,4 1000 1750
Benzene NO to 65 5 1
Toluene NO to 2.6 1000 ---
Ethyl benzene NO to 0.9 700 680
Not'e: ND = not detected. --- = no MCt.
Enforcement H.storv
Castle AFB was proposed for the National Priority List (NPL) of hazardous waste sites on July 22,
. .
1987. The Base was officially listed as an NPL site on November 21, 1989. The U.S. EPA, the State of
ailifomia, and the U.S. Air Force signed an interagency agreement, now known as the Castle AFB Federal
Facility Agreement (FFA), on July 21; 1989. The FFA is a legal docmnent that outlines the basic CERCIA
. .
process required of the Air Force, includiDg CERCLA procedures to address state requirements, and documents
the regulatoIy agency enforcement authority.
m.
IDGHLIGHrS OF COMMUNrIY INVOLVEMENT
The Community Relations Plan (CRP) for Castle AFB was completed in 1990 and \DlOfficially updated
in January 1992 by Castle AFB's Office of Public AffiUrs,in accordance 'With EPA guidance. Consistent with
the Base's Community Relations Plan, the Air Force established a Technical Review Connnittee composed of
EPA, the State of Califomia, the Air Force, Merced County, and local representatives from adjacent
comnnmities. The Technical Review COmmittee meets on a quarterly basis to provide the connnunity
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representatives with up-UHJate infonnation on recent mileStone events. Castle Am publishes and distn"butes
"Enviromnental Update", a connnunity newsletter, v.bich also serves to keep the community infonned of recent
activities.
A public meeting occun-ed on May 18, 1992 on the OU-2 analysis of altematives and the preferred
remedy. A public comment period for the Proposed Plan for OU-2 was held between May 4, 1992 and Jtme 3,
1992. A response to comments (Appendix B) is attached to this ROD.
. IV.
SCOPE AND ROLE OF 'THE OPERABLE UNIT
The identification of DischaIge Area NO.4 and Wa11ace Road ccmtnninat.ion as a ground water opemble
unit (OU-2) occurred in Spring of 1991. It was recogIrized by the EPA, the State of California and the Air Force
that defining OU-2 as a ground-water-only operable unit (i.e., excluding soils) would allow for earlier initiation
of ground water remedial action. The definition of OU-2 includes all aquifers vWrich may be contaminated below
the DA-40Va1Iace Road areas and ground water cnnt:mtil1at1on that may have migrated from these areas.. The
defini1ion of OU-2 also includes any ground water c:ontmnil1at1on south ofWa1Iace Road v.bich is not addressed
by interim OU-I. It was also recognized that further cbarncterization of potential soil cmrtmnination would
proceed under a subsequent investigation. ~ecti.on for the OU-2 remedial system will be designed to prevent
exasperating the contaminant plmne. This will be addressed during the RDIRA phase.
In 1986, v.ben VOC ccmtnninat.ion was identified in domestic ~lls Castle Am began actions to protect
public health by providing residents in the Wallace Road area with either carbon filtIation units or a clean
alternative water supply. Domestic wells in the yicinity are monitored regularly for contamination and, -M1en
necessary, the Air Force has provided.additional residences with carbon filtration or altemative water supplieS.
The Air Force initiated ground water removal action near the area of Discharge Area No.4 (on-Base) in July
1991 and additional pmnping has connnenced in the area ofWa1Iace Road (on-Base) in December 1991.
Based on the infonnation in the RI/FS for OU-2, finalized in Januazy 1992, COIItaminant concentrations
in the grmmd water exceed the Federal and California standards for dril11ci112 water for three compounds (fables
I and 2) and may present an imminent and substantial endangennent to hmnan hea11h. MCLs are exceeded for
TeE, tetrachloroethylene, and benzene. Therefore, remediation of the ground water is required to reduce
ccmtaminant concentrations in the ground vvater.
The ROD for interim Operable Unit No. I (OU-l), also a ground-water-onIy opemble unit, was finalized
in August 1991. The objective of OU-l, is to initiate early action to clean-up the most heavily contaminated
portion of the ground water under the main part of the Base and to attempt CODtainment of the contamination m
the Main Base Area. The remedial design for interim OU-I was finalized in late 1992. Consbuction of the
remedial system for interim OU-l is expected to be complete in December 1993. Inrerim OU-I is adjacent to
14
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OU-2 (Figure 1) and there is no distinct division between: the two areas of contaminmP.{f ground water.. However, .
it is the intent of the Air Force, EPA, and Cal-EPA, to design.the remedial systems ofboth iDterim OU-l and
OU-2 to be complementary.
In addition, the Air Force, EPA and Cal-EPA have planned the Comprehensive Base-wide RIIFS and
ROD. This final RI/FS and ROD will re-evaluate all previous operable units as well as address any remainiT1f
contmn1nation in the ground water and in soils. The final Comprehensive Base-wide RIIFS and ROD will also
re-evaluate risks associated with overall Base contamination and provide an opportunity to re-examine the taIget
. .
c1ean-u.p.levels established to protect hmnan health and the environment.
v.
SUMMARY OF OU-2 INVESTIGATIONS
Several studies and investigations have been peIfoImed at the Base to identify the historical use of
chemicals, the disposal of these chemicals into the ~oil and to deteIIDiDe the extent and impact of these chemicals
on the ground water in and around the Base. . The focus of this ,Record of Decision is on the finmTlg.c: of the
investigations applicable to the Wallace Road Area and DA-4 areas (OU-2).
The pace of environmental investigative activities at Castle AFB increased in 1989. 'Ilie investigation
activities have consisted of sampling programs to: (1) characterize kncmn on-site areas \Were hazardous
substances were disposed of in the past, (2) characterize off-Base areas where contamination is known to have .
spread and (3) screen' for the presence of contamination in areas where contamination may have spread.
Screening activities in the area of OU-2 included the testing of local orchard produce to deteImine if
contamination-uptake was present in the local almond crop. Air sampling was perfonned during crop inigation
to detennine if air-bome cnntamination could pose a potential health threat to local residents. Contamination was
not detected during either the crop study or the ambient air sampling study.
, . .
A Base-wide VOC-probe investigative effort was conducted in 1991 to further delineate the vertical and
horizontal extent of ground water contamination.
A Smf4ce and Subsurfuce Soils
As a ground-water-
-------
TabLe 3. VOC, TPH, AND METALS ANALYTICAL PROTOCOL
GROUND WATER SAMPLING ROUNDS 1 THROUGH 6
voc' TPH' Water
S~Ling S~Ling CLP quaLity
point round EPA EPA EPA metals parameterst
601 602 8015
MW440 1/2 Ie X X X X
3/4/5 X )( X .. d ..
6 -- .. -- -- ..
MW455 . 1/2 X X X X X
3/4/5 X X X .. --
6 -- - .. -- --
MW501 1/2 X X X X X
3/4/5 X X X -- ..
6 .. .. -- -- ..
MW502 1/2 X X X X X
3/4/5 X X X -- --
6 -- -- - - .. --
MW503 112 X X X X X
3/415 X X. X -- --
6 -- - - -- .. --
MW504 1/2 X X X X 'X
3/4/5 X X X .. ..
6 .. -- -- .. ..
MWS05 1/2 X X X .. X
3/4/5 X X X -- --
6 -- -- -- .. ..
MWS06 1/2 X X X -- X
3/1.15 X X X -- ..
6 -- .. -- -- --
MW507 1/2" X X X .. X
3/4/5 X X X ... --
6 .. .. -- -- --
MW508 1/2 . X X X -- X
3/4/5 X X X -- --
6 X X -- -- --
MWS09 1/2 X X X -- X '
3/4/5 X X X -- --
6 -- -- -- -- --
MW510 1/2 X X X -- X
3/4/5 X X X -- --
6 X X eo -- --
MWS11 1/2 X X X -- X
3/4/5 X X X -- --
6 -- .. -- -- --
MW512 1/2 . X X X -- X
3/4/5 X X X -- --
6 X X -- -- '..
MW513 1/2 X X X eo X
3/4/5 X X X -- ..
6 .. -- .. -- --
MWS14 1/2 X X X .. X
3/4/5 X X X eo ..
6 -- -- .. .. ..
16
-------
Table 3. VOC, TPH, AND METALS ANALYTICAL PROTOCOL
GROUND WATER SAMPLING ROUNDS 1 THROUGH 6
VOc" TPtf Water
S~ling Sarrpl ;ng CLP qual ity
point round EPA EPA EPA metals parametersC
601 602 8015
MW515 1/2 X X X -- X
3/4/5 X X X -- --
6 -- -- -- -- --
MWS16 1/2 X X X -- X
.. . 3/4/5 X X X -- --
6 -- -- -- -- --
MW576A 1/213/4 -- -- -- -- --
5/6 X X -- -- u
MW601 1/2 X X -- -- X
3/415 X X -- -- --
6 - - -- -- -- --
MW602 1/2 X X -- .. X
3/4/5 X X -- -- --
6 -- -- -- -- --
MW604 1/2 X X -- -- X
3/4/5 X X -- -- --
. 6 -- -- -- -- --
MW701 1/2 X X -- -- X
3/4/5 X X -- -- --
6 -- -- -- .. --
MW702 1/2 X X - - -- X
3/4/5 X X .. -- --
6 -- -- -- .. ..
MW702A 1/213 -- -- -- .. --
4/5/6 X X -- -- --
MW703 1/2" X X -- -- X
3/4/5 X X -- -- --
6 -- -- -- -- --
MW704 1/2 X X -- - - X
3/4/5/6 X X -- -. --
D5144 1/2 X X -- -- )(
3/4/5/6 -- . -- - - -- --
D5266 1/2 X X. -- -- X
3/4/5/6 -- -- -- -- --
15266 1/2 X X -- .. X
3/41516 -- -- -- -- --
D5486 1/2 X X .. -- X
3/415/6 -- -- -- -- --
D5502 1/2 X X - - -- X
3/4/5/6 -- -- -- -- --
15502 1/2 X X -- -- X
3/4/5/6 -- -- -- -- --
MID70 1/2 X X -. -- X
3/4/5/6 -- -- -- -- --
17
.~
-------
Table 3. vec, TPH, ANO.M~TALS ANALYTICAL PROTOCOL
GROUND WATER SAMPLING ROUNDS 1 THROUGH 6
VOC' TPHD Weter
Sall'f)ling SIIII'f)I i n9 CLP qu811 ty
point round EPA EPA EPA -tell per8llletersc
601 602 8015
15502 -- X X
.. eo X
3/4/5/6 -- -- ..
eo eo
"ID70 1/2 .X X " X
3/4/5/6 .. .. .. eo '-
8. Vol8tile organic cCll1'Ounds.
b. Totel petroleUII hydroc8rbons. ..
c. Total dissolved solids (EPA 160.1). major tons (EPA 300.0>. ha~ness (EPA 130.2>, pH (EPA
150.1). and specific conductance (EPA 120.1).
d. Not 8n8 I yzed.
e. One of 17 wells analyzed for pesticide enalysis using EPA 504 Mod.
B. Metals in Ground Water
SeJected ground water samples have been analyzed for metals (Table 3). The maximum metal
concentrations from this inv~tigative effort do not indicate a danger to public health or the environment.
Arsenic was detected at 10 jJgll; the MCL for arsenic in ground water is 50 jJglJ. Lead was detected
at 4 ~s'1; the MCL for lead in ground water is 50 ~gI1. However, additional metals analysis will be performed
during the design of the remedy to confirm water quality parameters for treatment and injection to the aquifer.
C. TeE and Other VOCs in Ground Water
Ground water contamination was originally detected in the area of OU-2 when the Air Force started
sampling local domestic: wells in 1986. Sampling of the domestic wells and the installation and sampling of
additional monitoring wells in the area yielded the data presented in Table 6. At present there are a total of 39
wells which have been sampled at OU.2 (Figure 3). Of these, 26 are Air Force monitoring wells and the
remainder are either private drinking water wells or private irrigation wells. All of these wells are screened in
various aquifen. Analytical protocols are presented in Table 3.
The principal contaminant identified in the ground water in the Wallace Road Area is TCE. ~er
contaminants found, but at lower frequency and lower concentrations are PCE, dibromochloropropane (DBCP).
toluene, benzene, ethyl benzene, xylenes. chloromethane, chlorobenzene. l,2-dic:hlorobenzene. l,2-dic:hloropropane
and methylene chloride (Tables 1 and 2). The maximum reported value for TeE in the OU-2 area is 740 Jlg/l
based on water quality monitoring perfonned by the Air Force. Additional infonnation on TCE and benzene
c:oncentrations and their spatial distribution Is available from preliminary field saeening results of depth-specific
18
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O£v~-9~L-60~~t:l31
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-------
Table 3. VOC. TPK, AND METALS ANALYTICAL PROTOCOL
GROUND WATER SAMPLING ROUNDS 1 THROUGH 6
VOC. TPHb Water
Sampl ing Sampling -I EPA CLP quali ty
point round EPA EPA metals parameters'
601 602 8015
a. Volatile organic compounds.
b. Total petroleum hydrocarbons.
c. Total dissolved solids (EPA 160.1), major ions (EPA 300.0), hardness (EPA 130.2), pH (EPA
150.1), and specific conductance (EPA 120.1). '
d. ... Not analyzed.
e. One of 17 wells analyzed for cesticide analvsis using EPA 504 Mod.
B. Metals in Ground Water
Selected ground water samples have been analyzed for metals (fable 3). The maximum metal
concentrations from this investigative effort do not indicate a danger to public health or the environment.
Arsenic was detected at 10 J.1g/l; the MCL for arsenic in ground water is 50 J.1g/l. Lead was detected at 4 J.1g/l;
the MCL for lead m ground water is 50 J.1g/l. However, additional metals analysis will beperfimned during the
design of the remedy to confum water quality par.uneters for treatmeIIt and injection to the aquifer.
C. TCE and Other VOCS in Ground Water
Ground water contamination was originally detected m the area of 0U-2 ~ the Air Force stMtOO
sampling local domestic wells m 1986. Sampling of the domestic wells and the installation and sampling of
additional monitoring wells m the area yielded the data presented in Table 6. At present there are a total of 39
wells which have been sampled at 011-2 (Fi~ 3). Of these, 26 are Air Force monitoring wells and the
remainder are either private drinking water wells or private inigation wells. All of these wells are screened in
various aquifers. Analytical protocols are presented m Table 3.
The principal contam1n:mt identified m the ground v.mer in the Wallace Road Area is TCE. Other
contmnin:mt~ fOUIld. but at lower ftequency and lower con.centI3tions are dibromocb1wuplupcwe (DBCP), toluene,
benzene, ethylbenzene, xylenes, chloromethane, chI0r0benzene, 1,2-
-------
has generally non-detect levels based on two monitoring wells (MW601 and MW602) and limited VOC probes.
TCE was detected in each well at only one sampling event at a maximum concentration of 1.2 ~, less than the
MCL of 5~. No other sampling events detected TCE.
A summaI)' of the concentration range of TCE and the other cnntmnin:rnt~ identified in ground water in
the area of OU-2 is provided in Tables 1 and 2. The results of the quarterly ground water monitoring rounds are
presented in Table 6.
D. ~ Investigation
In early 1991 the Air Force conducted an investigative screening effort to cletem1ine the horizcmta1 and
vertical extent of contamination in ground water. VOC probe sampling is a screeningIsampling investigative
technique used to obtain ground water samples at varying depths w.bile drilling. The sample integrity is such that
the loss of VOCS is minim!!l. Ground water samples are collected and analyzed in the field to detennine \W.en
drilling'sampling of a location has been advana:d to a sufficient depth for vertical cbamcterization pwposes.
FIfteen V9C probes were installed in and armmd the Wallace Road Area and DA-4 in early 1991. A total of 26
VOC probes were drilled Base-wide (HAZWRAP VOC Probe Results for Castle AFB, Februa1y 1992). This
data was useful in partially characterizing the exrent of contamination and in the development of the OU-2 plmne
characterization (Figme 1).
The area-wide extent of the TCE contaminant plmne is partially based on the VOC probe screening
investigative results for the upper and lower shallow aquifer and the ~ed aquifer. The plmne as identified
for the lower shallow aquifer is relatively broad-based near the Base boundazy. The Wallace Road portion of the
plmne in each of these aquifer units appears to consist of two lobes, one trending toward the west and the other
toward the south.
In early 1993 the Air Force conducted an additional investigative screening effort in the OU-2 area in
order to further characterize the verticle and horizontal extent of contamination in ground water and to detennine
design parameters for the selected remedial action. A total of fifteen Hydropunch borings were installed (OU-2
Hydrogeological Technical Memorandwn, October 1993). Seven of these borings were converted to monitoring
wells. Four other monitoring wells were also installed. This data was useful in further chaIacterization of the
extent of contamination (Figme 1) as well as providing design pammeters for the selected remedial action. .
19
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E. Data Validation
The remedial investigation database was validat.ed in accordance with EP A guidance and meets the
objectives ofNCP Section 300.43O(b)(8)(ri):in that the data quality is sufficient to support the selection of the
remedy. All data used in the risk assessment was validated in accordance with EPA Region 9 guidance.
VI. .. "SUMMARY OF OU-2 RISKS
The risk assessment contained in the RI!FS for OU-2 (Janwuy 1992) evaluates the public health and
enviromnental risks posed by VOCs at OU-2. TCE is the primaIy chemical of concern at OU-2; however,
numerous other VOCS have been detected :in the ground water at both DA-4 and the Wallace Rqad Area. It was
also considered that TCE-breakdown-products such as vinyl " chloride may also be present in OU-2. Therefore,
samples were specifically analyzed for vinyl chloride in addition to the other VOCS. No vinyl chloride was
detected. . In accordance with U.S. EPA, Region IX Risk Assessment Guidance, chemicals much were detected
in fe\\er than five percent of the samples analyzed for OU-2 were elimin:rtP.rl fiom consideration in the
quantitative risk assessment. Following the screening process, the constituents below were considered in the
baseline risk assessment as chemicals of concem:
OUorofonn
OUoromethane
Tetrachloroethylene (PCE)
Trichloroethylene (TCE)
Qs-I,2-dichloroethylene
Xylenes
Toluene
Etbylbenzene
Benzene
Cblorobenzene
Hmnan Health Risk
Potential exposed populations at and near OU-2 include residences, on-site worlrers, visitors or
trespassers who might come in contact with the C(II1t:m1in:rtP4 ground water, and off-site ~ or residents
who might came in COJJtact with the oontamin:rtP.rl ground water. Because residential development is located on
part of OU-2 and because there is a possibility of residential development of the base after closure, risks for OU-
2 have been evaluated assuming a future resideJItial exposure scenario.
Potential exposure pathways identified in the risk assessment included ingestion of CODtaminated ground
water, inhalation of vapor-phase chemicals mule showering with contaminated ground water, and inhalation of
vapor-phase chemicals from spray irrigation with ground water. Conservatively, to assure that risks were not
underi:stimated the highest concentmtion of each chemical of concem observed was used as the exposure point
22
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concentration. In calculating the exposure for 30 years for an adult the risk "tfmnifiit assumed a body weight
of 70 kg, consumption of two liters of water per day. Further detail regarding risk assessment assumptions can
be found in the KI/FS for OU-2 (January 1992) Section 7.
The risk assessment concluded that the excess lifetime cancer risks, assuming residential use of
contaminated ground water and spray irrigation (ingestion and inhalation) located at OU-2, for all chemicals of
concern, is estimated at 1.99E m (adult) and 1.83E * (child). The major contributor to risk was TCE exposure
through inhalation while showering. Risk associated with ground water ingestion and inhalation exceeded the
range generally considered to be acceptable by EPA (l.OE "* to l.OE *) pursuant to the NCP, 40 C.F.R. Section
300.430(e)(2X'XAX2)- Additionally, TCP. is a known carcinogen and is present in the ground water at levels
that significantly exceed the federal aod California drinking water standards for this chemical. Drinking water
(chemical-specific) standards arc health-based levels and may be used to determine whether remediation is
warranted.
Seventeen volatile organic compounds (Tables 1 and 2) have been detected in the ground water in the
area of OU-2. Ten were determined to be present at levels which could pose health risks (refer to Section VI,
Summary of OU-2 Risks). Trichloroethylene (TCE) is the most prevalent and mobile contaminant, and is
therefore determined to be an indicator chemical. The risk assessment contained in the RI/FS for OU-2 identifies
TCE as the major contributor to health risks. The VOC chemicals which will be remedied in OU-2 are
trichloroethylene (TCE), tetrachloroethylene (PCE), and benzene. While some lower health risk will remain due
to remaining residual contamination from the VOCs, reducing the level of contamination of TCE, PCE and
benzene to Maximum Contaminant Levels (MCLs) will lower risks to an acceptable range (l.OE "* to l.OE4).
EPA considers the results of the baseline risk assessment and compares OU-2 concentrations to
chemical-specific standards to assess whether there is an unacceptable risk to human health or the environment in
making the decision as to whether remediation at a site is appropriate. EPA has determined that the ground
water contamination at OU-2 poses an unacceptable risk to human health because ground water at OU-2 (1) is a
drinking water source that contains carcinogens and if unabated poses an excess risk of more than l.OE "* to
1 .OE "* and (2) exceeds federal and state drinking water standards (Tables 5A and SB). The risk calculation for
ground water is summarized below.
SUMMARY OF CARCINOGENIC RISKS
Exposure Pathway
Ingestion
Inhalation/Vapors
Irrigation/Vapors
Total Pathway Risk
Adult
7J6E*
1.91E*
3.9IF"
1.99E"
Child
3.52E-04
1.79E*1
3.65E-"
1.83F"
24
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-------
SUMMARY OF NON-CARCINOOENIC HAZAR.D
Expu'Ule Pathway Adult Child
Inge~tion 4.48~ 1.0S~1
InhalationNapors 1.29~' 6.00~1
IrrigationIVopors 2.63~s 3.7sF"
Total Pathway Hamd 1.74£-41 7.0,~1'
Environmental Rlsle
Table 3-A iIIustratcs the Federally and/or State-Listed species potentially occurring in the region of
Castle AFB. Although the presence or absence of these speeies is being determined at the Base, potential
exposure to ground water in the OU-2 Grea is judged to be less than that estimated for humans in the future
residential scenario.
2S
90'd POD' ON 8S:0T
£6'OT /\ON
O£P,-9,l-60,-T:l31
a~~ 3l1S~~ ~3~/S3J £6
-------
Table 3-A Federally or State-Listed Species Potentially Occurring in the Region of Influence of Castle AFB
Federal State
Name Status Status CNPS Habitat and Distribution
PLANTS
Henderson's bentgrass C2 3 Occurs in vernal pools and in
(Agrostis microphyllaWlf. valley and foothill grassland.
. henders0171) Known to occur east of Castle
AFB.
Hoover's rosinweed C2 IB Occurs in valley and foothill
(Colycaknia hooven) grassland, cismontane
woodlands. Known ftom
various locations within Merced
Cowrty.
Beaked cIarlcia (Clarlcia Rostn:zt4 C2 1 B Occurs in valley and foothill
Grassland, cismontane
woodland. Known to occur
northeast of Castle AFB.
Colusa grass (lVeostapha Cl E IB Occurs in vernal pools. Known
colusC111d) to occur near Castle AFB.
San Joaquin orcutt grass Cl E IB Occurs in vernal pools. Known
(Orcuttia inaequali~ to occur northwest of base.
Considered likely to occur at .
Castle AFB.
Pilose on:utt grnSS (01r:uttia C1 E m Occurs in vernal pools. Known.
pilosdj to occur in areas north and
west of base. Considered
likely to occur at Castle AFB.
fleshy owl's clover C2 E 1B Occurs in vernal pools. Known
(Orthocarpus campestrls var. to occur east and west of base.
succulentus) Considered likely to occur at
Castle AFB.
Merced phacelia (fhacelia C2 1 B Occurs on clay soils in a variety
ciliatavar. opa:a) of habitats. although primarily .
in valley and foothill grnSsland.
Known to occur southeast of
base. May occur at Castle
AFB.
Green's tuctoria (/'uctoria Cl R IB Occurs in vernal pools. Known
greenei) to occur northwest of base.
Considered likely to occur at
Castle AFB.
25
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Federally or State-Listed Species Potentially Occmring in the Region of Influence of Castle AFB
Name
Federal
Status
State
Status
CNPS
Habitat and Distribution
ANIMAlS
Jnvertebrntes
.~
. Vemal pOol £airy shrimp
(J3ranchinecta lyndu)
PE
Larvae are stem and root borers
of elde1beny. Adults feed on
its foliage and flowers. Not
expected to occur at Castle
AFB due to absence of
elderbeny trees.
May inhabit vernal pools on
Castle AFB.
Valley eTde1beny longhom T
beetle ({)esmocerus cal.ifomzcus
dlmotphus)
Vemal pool tadpole shrimp
(Lepidunis packardJ)
Conservancy faity shrimp
(Branchinecta conservatiq
PE
May inhabit vernal pools on
Castle AFB. .
PE
May inhabit vernal pools on
Castle AFB.
Califomia linderiella fl-intkriel/a PE
occidentalis)
May inhabit vernal pools on
Castle AFB.
AropBliam
Califomia tiger ~1:m1:mder
(Amhystoma cal.ifomiens~
C2
csc
Breeds in tempoI3IY pools and
peunanent waters of grassland
and open woodland of low hills
and valleys; eliminated from
much of its fanner Central
Valley range by agriculture and
mban developments. Suitable
habitat occurs on Castle AFB.
Reptiles
Blunt-nosed leopard lizard
(Gambelia sUus)
E
E
Occurs in scattered locations,
inhabits sparsely vegetated
plains and semi-ariCl grasslands.
Castle AFB is within distribution
of species and contains marginal
habitats. Not expected to occur on
Castle AFB.
26
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Federally or State-listed Species Potentially Occurring in the Region of Influence of Castle Am
Federal State
Name Satus Status CNPS Habitat and Distribution
Giant garter snake PE T Occurs in streams and sloughs,
(Thamnophis gig~) usually with mud bottoms,
range includes floor of Q:ntral
Valley fttm Delevan National
WIldlife Refuge in Colusa
County to Los Banos Creek and
Mud Slough in San Joaquin
Valley. Castle AFB is outside
the nonna! rcmge of this
species. Further, it would not
be expected on base due to
dredging of drainage ditches
v.bicb are the only pennanent
3quatic habitat on base.
Southwestern pond turtle Cl CSC Found in rivers, ponds, and
(Clemmys marmorata pallid4 ditches with pennanent water
flow, usually in woodland,
grassland, and open forest.
Castle AFB is outside the
nonna! range of this species.
Fmther, it would not be
expected on base due to
dredging of drainage ditches
v.hicb are the only pennanent
aquatic habitat on base.
Birds
American peregrine falcon E E
(Falco peregrinus anatum)
Rare and local, nests on
Protected ledges of high cliffs
and foIages primarily in coastal
and inland marshes and riparian
areas. Nesting habitat is not .
present in the vicinity of Castle
Am but breeding does occur in
Yosemite National Parle.
Aleutian Canada qoOse E
(Bmnta conaknsis lelicopareiq
Wmter visitor or migrant in
Central Valley of Qilifomia.
Feed in wetlands, grasslands,
and cultivated fields during
miqrations. Vernal pools on
Castle AFB could offer some
suitable habitat.
27
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Federally or State-Listed Species Potentially Occurring in the Region of Influence of Castle AFB
Fedetal State
Name Status Status CNPS Habitat and Distribution
Loggerl1ead shrike C2 Fairly connnon and inhabits
(Lanius ludovicianus) open grassland and pastures. ~
Observed during September
1992 field visit.
Tricolored blackbird C2 Habitat includes cattail and tule
(Agelaius trieoloF) marshes; forages in gI3S-c:laniis
and agricultmal areas. No
suitable nestinglroosting
habitat on base, though
foxaging habitat is present.
Mumnals
San Joaquin kit fox E R Occurs from the soutbem end
(Vulpes ma::rotis muticq of the San Joaquin Valley tn
Contra Costa County along the
westem footbills and Interior
coastal range valleys. Castle
AFB is within historic range of
kit fox though it is outside of
its current distribution.
Grassland habitat on base
would be suitable for kit fox if
this species' distribution
expanded and other
~titive fox species (red
fox) were not a threat.
Fresno kangaroo 131 E. E Restricted to a1.kali sinks in
(Dipodomys nitrr:rJoides exili~ Fresno County in the vicinity of
Kelman. Castle AFB is outside
the present distribution of this
species. .
Pacific westem big-eared bat C2 CSc Occurs in mra1 areas and is
(Pleeotus townsenil) most common in moist sites.
Habitat nmst include
. ap}/lVpIiate roosting sites (i.e.,
caves, tmmels, or abandoned
buildings), which are not found
on or near Castle AFB.
28
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Federally or State-Listed Species Potentially Occuning in the Region of Influence of Castle AFB
Name
Federal
Status
Greater western mastiff-bat
(Eumops perotis californicuSj
C2
State
Status
CSC
CNPS
Habitat and Distribution
-.
Prefers rocky canyons and
creviced cliffs and is an .
uncommon resident in the San
Joaquin Valley. This speci~
will roost in tall,buildings.
trees, or tmmels. This species
is unlikely to be present on
base.
.~
Notes: Federal staJus.
E = Listed as Endangered by the U.S. FIsh and Wildlife Service (USFWS)
PE ; = Proposed as Endangered by the USFWS.
T = Listed as 1hteatened by the USFWS.
a = Category I candidate for federal listing. (Taxa for which The USfWS has sufficient biological
WfUuUdtion 10 supPort a proposal 10 list as Endangered or ~.)
= Category 2 candidate for federal listing. (Taxa which existing infonnation indicates may wammtlisting,
but for v.bich substaJJtial biological infonnation to support a proposed rule is lacking.)
= "Recommended" for Category 2 status by the USFWS.
C2
2R
California staJus.
E = Listed as Endangered by the State of Califomia. .
T = Listed as Threatened by the State of Califomia.
R = Listed as Rare by the State of California.
CSC = California Department of FIsh and Game "Species of Special Concern".
California Native Plant Society (CNPS) stotus
I B = Plants listed as Rare Threatened or Fndangered in California and elsevmere.
3 = Plants about which we need more infonnation - a review list.
29
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Risk Summarv
Release of hazan:lous substances from OU- 2 has resulted in the contamination of ground water that presents
an imminent and substantial endangennent to public health, welfure or the environment if the releases from OU-2
are not addressed by implementing the remedial response action selected in this ROD. The removal action at
DA-4 and Wallace Road may reduce OU-2 risks, hOwever, growid water contmnination remains beneath OU-2
which exceeds drinking water standards and requires remedial action.
.~
Vll. DESCRIPTION OF AL1ERNATIVES
This section describes the six altematives evaluated by the OU-2 RI/FS in selecting the final cleanup plan
for OU-2. The FS presented and compared the six altematives using nine criteria required by the NCP (40
C.FR ~. 300.430(e)(9» in the Feasibility Study. The nine criteria are:
- overall protection of hmnan health and theenviromnent,
- compliance with applicable or relevant; and appl0fU.lare requirements (ARARs).
- long-tenn effectiveness and pennanence,
- reduction of toxicity, mobility, or volmne through treatment,
- short-tenn effectiveness,
- implementation,
- cost,.
- state acceptance, and
- community acceptance.
These criteria are categorized into three groups in accordance with the NCP ~300.430(f)(1)(i)(A), (B)
and (q:
(1) The threshold criteria: the overall protection of hmnan health and the enviromneirt; and compliance
with applicable or relevact and applUpliate requirements. Each alternative nmst meet the ~shold criteria
in order to be eligible for selection.
(2) The primary balancing criteria: long-teDn effectiveness and pennanence; reduction of toxicity,
mobility, or volmne through treatment; short-teIm effectiveness; implementability; and cost.
30
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(3) The modifying criteria: both state and community acceptance are modifying criteria that shall be
considered in remedy selection.
The nine criteria are described in more detail in Part VIII ("Summary of Comparauve Analysis of
Alternatives"), and in Table 4.
The focus of Ihe Feasibility Study was on the achievement of the drinking water standards in ground water
at .the end .of the remedial action. The aquifers underlying DA-4 and Wallace Road are designated by the State
of California as sources of drinking water and therefore must be restored to drinking water quality standards.
The federal and State drinking water standards for the chemicals, for which aquifer standards have been
developed are presented in Tables S-A and 5-8. The alternatives described below, except the no-action
alternative, employ different approaches but are designed to meet these standards in the aquifer over the
indicated time periods.
~ch alternative would require periodic ground. water monitoring to determine the effectiveness of the
clean-up and to verify achievement of the clean-up standards. The details of the specific ground water
monitoring program will be determined during remedial design, using information from the operating removal
action. Effectiveness of the selected remedy will be illustrated through implementation of the ~ng term
Groundwater Sampling Plan.
No-Action Alternative
The NCP requires that a no-action alternative be considered at each site or operable unit. The no-action
alternative serves primarily as a point of comparison. to other alternatives. Continued groundwater monitoring is
the cost associated with this alternative. No active treatment systems would be implemented in this alternative.
As demonstrated by the risk assessment for OU-2, this alternative is not acceptable since it would not result in
overall protection of human health or the environment.
Alternative I
Alternative I would.not provide any treatment or exuaction of contaminated ground water. Instead,
Alternative I, based on institutional controls, depends on natural attenuation of the VOCs to meet the cleanup
levels. The institutional controls to be used under this alternative are imposing deed restrictions to prevent
contact with the contaminated ground water and providing city water to the affected residents
-------
93 CES/CEV CASTLE AFB
TEL:1-209-726-2430
NOV lU,~~
l~;~~ NO.U~q ~.U~
Alternative I provides no near-term reduction in risk to human health posed by the contaminated ground
, water. It allows for the possible continued migration of the contaminant plume and further degradation of the
ground water. The carcinogenic risk resultins from this alternative is l.99E.Q% (adult).
The long-term reliability of institutional controls to prevent use, of the contaminated ground water is
problematic. Therefore. all current and potential future risks are assumed to remain under this alternative.
This alternative provides no reduction in toxicity. mobility, or volume of the contaminated ground water
through treatment. There would be additional risks posed to the community and the environment as a result of
this 8Jiemative being implemented since the contaminant plume would continue to spread. As the plume
spreads, more wells are likely to become impacted.
It is estimated that the annual operation and maintenance (O&M) cost for Alternative I is $30,000. This
cost oc:cun in each of the remaining four alternatives examined in this detailed analysis since on-going
monitoring of the contamination plume is required in each case. This cost reflects on-going sampling and
analytical activities.
Alternative n - Packed Tower Air Stripper
In this altemative. the ground water would be pumped from the shallow Aquifer and treated in a packed
tower air stripper. Treated water would be injected into the same aquifer. The contaminated ground water is
introduced into the top of the tower by distribution nozzles and allowed to flow by gravity over a bed of packing
material to a clearweU at the bottom. Packing 'material occupies the majority of the height of the, tower above
the clearwell. The choice of the packing would be designed to maximize surface area and to enhance air-water
\ ,
contact while minimizing the air pressure drop through the tower and be cost effective. ' Air traveling
countercurrent to the water would be forced into the bottom of the tower by a blower. and would exit at an
exhaust pan at the top. As the air moves through the tower, TCE and other VOCs would be stripped from the
water and transferred to the vapor phase.
Carbon adsorption is the tcclmology chosen to reduce air emissions as the Best Available Control.
Technology (BACT) as required by the San Joaquin Valley Unified Air Pollution Contro] District (APCD).
Monitoring would be required to determine the breakthrough point of the carbon vessels. Initially. the sampling.
frequency for the carbon vessels would be once a week. rms frequency would be reduced once a time frame
for breakthrough is established. The use of carbon adsorption as the emisSion control system requires
regeneration or disposal of the spent carbon, The volume of carbon required for air phase removal, of TeE and
other VOCs is considerably less than that required for watefphase removal. The cbange-out frequency for the
vapor phase carbon system is estimated to be approximately once evCl)' three months.
Scale prevention must be considered as pan of the design of the air stripper. Due to levels of hardness
and alka]inity in water samples coJlected from 1he shallow aquifer, scaling of the tower packing during operation
33
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Alternative I provides no near-tenn reduction in risk to hmnan health posed by the cnntamln:rtf"fl ground
water. It allows for the possible continued migration of the contaminant phnne and finther degradation of the
ground water. The carcinogenic risk resulting from this alternative is 1.99f!02 (adult).
The long-tenn reliability of institutional controls to prevent use of the COIItaminated ground water is
problematic. Therefore, all cmrent and ~ future risks are asswned to remain under this alternative.
This aItemative provides no reduction in toxicity, mobility, or volmne of the contaminated ground water
through treatment. There would be additional risks posed to the crnmmmity and the environment as a result of ..
this alternative being implemented since the contaminant plmne would continue to spread. As the plmne spreads,
more wells are likely to become impacted.
It is estimated that the ammal operation and maintenance (O&M) cost for Altemative I is $30,000. This
cost occurs in each of the remaJnlT\f four alWmatives examined in this detailed analysis since on-going
monitoring of the contamination phnne is required in each case. This cost reflects on-going sampling and
analytical activities.
Alternative II - Packed Tower Air Stripper
In this alternative, the ground water would be pmnped from the shallow Aquifer and treated in a packed
tower air stripper. Treated water would be ~ected into the same aquifer. The cantaminated ground water is
introduced into the top of the tower by distribution nozzles and allowed to flow by gravity over a bed ofpacking
material to a clearwell at the bottom. Packing material occupies the majority of the height of the tower above
the clearwell. The choice of the packing would be designed to maximize surfuce area and to enhance air-water
contact -MUle minimizing the air pressure drop through the tower and be cost effective. Air traveling
countercurrent to the water would be fon:ed into the bottom of the tower by a blower, and would exit at an
exhaust port at the top. As the air moves through the tower, TCE and other VOCS would be stripped from the
water and transferred to the vapor phase.
Carlxm. adsOIption is the technology chosen to reduce air emissions by 95% or more as required by the San
Joaquin Valley Unified Air Pollution Control District (APCD). Monitoring would be required to detennine the
breakthrough point of the carbon vessels. Initially, the sampling frequency for the carbon vessels would be once
a week. This frequency would be reduced once a time ftame for breakthrough is established. The use of carbon
adsorption as the emission control system requires regeneration or disposal of the spent carlxm. The volmne of
carbon required for air phase removal of TCE and other VOCS is considerably less than that required for water
phase removal. The cbangtHmt frequency for the vapor phase carbon system is estimated to be approximately
once every three months: .
. .
Scale prevention must be considered as part of the design of the air stripper. Due to levels ofbaIdness and
alkalinity in water samples collected from the sballow aquifer, scaling of the tower packing during operation is
32
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likely. This phenomenon occurs 'when carbon dioxide (COJ is stripPed ftom the water along with the TCE
(and other VOCS). The stripping of CO 2 increases the pH of the water, resulting in precipitation of calcimn .
carbonate. A continuous acid addition system 'WOUld not be necessary; however, semiannual acid washing of the
tower would be perfonned, with acid neutJ:alizatjon of the waste prior to discharge to the Base sewer. A .'
scheduled shutdown would be required approximately once eveI)' six months for this pmpose.
In this alternative, as with all the treatment aJ:tematives (Alternatives n through V), the 1reated effluent is
~ected into the shallow aquifer using recbaIge wells. Injection of the treated waste stream is the chosen.
technology for disposal of treated ground water tbatmeets effiuent limits established in this ROD. By ~ection,
depletion of the aquifer by the selected remedy is prevented. The method proposed for ~ection 'WOUld entail the
construction of ~ection wells screened in the shallow aquifer in which the ~ected water would be fed into the
aquifer by gravity flow via the ~ection wells. The optimmn location and mnnber of wells and well ~ection
Iates would be based on a hydraulic evaluation USing ground water flow modeling simulation and best
professional judgement.
Monitoring of grmmd water flow conditions resulting ftom the combined effects of ~ection and extraction
'WOUld entail water level measurements in monitoring wells located in the plwne. Injection well perfonnance in
tenns of roainmimng selected ~ection Iates 'WOUld be evaluated quarterly. The evaluation would be based on
measured ~ection Iates and measured water level head build-up in each of the injection wells. An established
perfonnance criterion, for each ~ection well, as detennined by aquifer testing at the time of well constructi.on,
development and subsequeDt ground water level monitoring, would be used to detennine the need for
. .
modification to the injection rate and/or the need for servicing the well to maUttain perfonnance levels as
established at the time of opemti.ons start-up.
Alternative n would be protective of both hmnan health and the enviromnent. Ground water extraction
and treatment would reduce the threat.to human health by ingestion of contaminated ground water, and reduce
the possibility of further enviramnental degradation. The aquifer treated by this a1temative would meet tht:
federal and state promulgated maximum contaminant levels (MCLs) for TCE and the other cnnrnmin:mt~
identified as part of OU-2. The carcinogenic risk resulting ftom this altemative is 6.73E-07 for ingestion of 5
. .
J1g/l TCE in ground water and 1.70E-OS for inhalation of TCE vapors while showering. . The showering scenario
asswnes a TCE conceotIati.on of 5 J.I!¥l in ground water. .
The air emissions ftom the treatment system 'WOUld be min1mal with the addition of the air emission control
system. The aff-gases ftom the packed tower air stripper would be filtered by granular activated carbon (GAq.
GAC:filtration is one of the more effective means to capture volatile oIganic compounds. WIth.this treatment air
emissions will be negligJ.Dle. This a1temative will meet all air emission ARARs developed under the Califomia
Mu1fard-Cazrell Resources Act, as administered by the San Joaquin Valley Unified APCD.
To provide for long-teIm effectiveness of this a1temative, careful maintenance of the CODtrols would be
needed. Hmnan health risks posed by dennal contact, ingestion, arid inhalation of ground water in the future
33
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is likely. This phenomenon occurs when carbon dioxide (CO J is stripped from the water along with the TCE
(and other VOCs). The stripping of CO 2 increases the pH of the water, resulting in precipitation of calcium
carbonate. A continuous acid addition system would not be necessary; however, semiannual acid washing of the
tower would be performed, with acid neutralization of the waste prior to discharge to the Base sewer. A
scheduled shutdown would be required approximately once every six months for this purpose..
In this alternative, as with all the treatment alternatives (Alternatives II through V), the treated effluent is
injected into the shallow aquifer using recharge wells. Injection of the treated waste stream is the chosen
techno~0.BY for disposal of treated ground water that meets effluent limits established in this ROD. By
injection, depletion of the aquifer by the selected remedy is prevented. The method proposed for injection
would entail the construction of injection wells screened in the shallow aquifer in which the injected water
would be fed into the aquifer by gravity flow via the injection wells. The optimum location and number of
wells and well injection rates would be based on a hydraulic evaluation using ground water flow modeling
simulation and best professional judgement.
Monitoring of ground water flow conditions resulting from the combined effectS of injection and extraction
would CDt:,il water level measurements in monitoring wells located in the plume. Injection well performance in .
terms of maintaining selected .injection rates would be evaluated quarterly. The evaluation woUld be based on
measured injection rates and measured water level head build-up in each of the injection wells. An established
performance criterion, for each injection well, as detennined by aquifer testing at the time of well coDStruction,
development and subsequent ground water level monitoring, would be used to determine the need for
modification to the injection rate andlor the need for servicing the well to maintain performance levels as
established at the time of operations start-up.
Alternative II would be protective of both human health and the enviromnent. Ground water extraction
and treatment would reduce the threat 10 human health by ingestion of contaminated ground water, and reduce
the possibility of further environmental degradation. Tbe aquifer treated by this alternative would meet the
federal and state promulgated maximum contaminant levels (MCLs) for TCE and the other contaminants
identified as part of OU-2. Tbe carcinogenic risk resulting from this alternative is 6.73E 41 for ingestion of 5
pg/l TCE in ground water and 1.70E.(15 for inhalation of TeE vapon while showering. The showering scenario
assumes a TCE concentration of 5 pgll in ground water.
The air emissions from the treatment system ~ou1d be minimal with the addition. of the air emission.
control system. The off-gases from the packed tower air stripper would be filtered by granular activated carbon
(GAC). GAC filtration is considered Best Available Control Tcdmology (BACT) and is one of the more
effective means to capture volatile organic compounds. With this treatment air emissions will be negligible.
This alternative will meet all air emission ARARs developed under the California Mulford-Carrell Resources
Act, as administered by the San Joaquin Valley Unified APeD.
34
- - - - -_.
- ... --. ......- ,.....~ ;"'..,""" ,...,
-------
would be reduced. To detennine its long-tenn effectiveness, the air stripper would be monitored under a long-
tenn program. Any modifications to the system would be based on evaluation of monitoring results.
The air stripper will reduce the toxicity, mobility, and volume of TCE and other VOCS in ground water.
TCE and other VOCS would be removed from the pmnped water by treatmeIIt with an air stripper. Contaminants
. in the air stream will be minimal due to the air emissions control system.
Alternative n meets the statutory preference for using treatment as a principal element since the principal
threat is addressed through treatmeIIt. Safety teclmiques, including monitoring the eqnipment, will be used to .
. .
minimize any failures of the components. Once the exlraction and air stripper systems are installed, the
(:()I1taminmrt plmne will begin to reCede from its current: position. There are no additional risks to the oonmnmity
in the short-tenn. An approved health and safety plan will be implemented for workers \\he> may come in
contact with contaminated ground water. The 1ime required to achieve MCLs in the ground water (m situ) is
approximately 16 years.
This alternative involves the use of a proven technology. Air stripper treatment uses equipment that is
readily available. Operntors are also readily available and easily ttainOO. Operntion of this altemative would
require monitoring of the ground water and the treated effiuent to assess the effectiveness of the air stripper.'
Controlling the opemling conditions would be neceSsaty to ma1nrnin the effectiveness of this system. .
Engineering judgment would be required during operation to detennine the operating parameters, such as air flow
rate in the air stripper and VOC ('.()I1tamination in the exhaust gas. The system could be easily modified if
additional cnntmninM1t!: were detected.
The capital cost for Alternative n is estimated to be $340,000 with projected ammal O&M costs of
$290,000.
Alternative m - Steam Stripper
Steam stripping is a conventional method of removing gases or volatile OIganics from water. The
technology of steam stripping is essentially fractional distillation with steam as the energy source.
The feed water is first heated in a heat recovery heat exchanger prior to being introduced into the top of the
tower. Nozzles distribute the water across the packing v.here it is allowed to flow by gravity to the reboiler at
the bottom of the tower. Additional heat is imparted to the waste stream by an extemalloop of boiler steam in
the reboiler.
Heating of the feed liquid occurs at two points in the process. The first point is prior to ~ring the tower
by a heat exchanger, the second is in the bottom of the tower by an extemalloop of steam. The vapor produced
then rises through the tower, countercuIreDt to the water, and enters a reflux condenser at the top. As the steam
rises through the tower, the TCE (including the other VOCs) concentration in the vapor phase increaSes and that
in the water phase decreases. The reflux condenser receives the concentrated TCFIwater (and VOCIwater) vapor
34
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.- . .-.'--
and condenses the mixture into a separator built into the condenser. The contaminants drop to the bottom of the
separator and the water rises to the top. The water is returned to the tower for finther treatment and the liquid
TCE (and VOCS) is removed from the bottom of the separator.
Like air stripping. this a1temative would require air emission control due to regulations of the San Joaquin
Valley Unified APCD. CaIbon adsmption is the technology of choice. Approximately one 55-gallon drum of
spent carbon is expected to be generated per month. It would also be necessary to dispose of the 'I'CE'fwater
solution removed from the bottom of the separator. This solution is expected to contain a 9: 1 mtio of TCE to ~
.water. . .
Scale prevention would be addressed as part of the design of the steam stripper. Based on the hardness and
a1kalinity of ground water in the shallow aquifer, scaling of the tower packing is likely. A conbnuous acid
addition system would be required since scaling would pose a problem in the perfonnance of the steam stripper.
As described for Alternative II, the treated effluent in Altemative n is injected into the shallow aquifer
using wells. Identical monitoring of well perfonnance will be conducted as for Alternative n.
Alternative ill would be protective of both hmnan hea1th and the environment. The assessment for this .
alternative'is very much like the assessment for Alternative n.
Long-tenn monitoring would be necessary to evaluate the effectiveness of the system. There would be no
additional risks to the community in the short-tenn for this altemaiive. An approved hea1th and safety plan will
be implemented for WOIkers who may came in contact with contaminated ground water. The area1 extent and
the contaminant levels v.ithin the plume are expected to decrease once this alternative is operational. The
carcinogenic risk resulting from implementation of this aItemative is 6.73E'7 for ingestion of 5 ~ TCE in
ground water and 1.70E -05 for inhalation of TCE vapors while showering. The showering scenario assmnes a
TCE concentration of 5 ~ in ground water. The time required to achieve MCLs in the ground water (m situ)
using Alternative m is approximately 16 years.
The steam stripping system would reduce the toxicity, mobility and volume of TCE in ground water.
Steam stripping emission control is a proven technology for treatment ofVOCs and equipment is readily
available. A steam supply is required and some specialized operator 1Iaining may be required due to the use of
high-pressure steam. Carlxm from the air emission control system will have to be replaced or regenerated on a
regular basis. The TCFJwater (V0CsIwater) condensate will also have to be disposed or recycled. The ~
cost is approximately $1,400,000 with annual O&M costs of $780,000.
Alternative IV - Cazbon Adsmption
Liquid phase carbon adsoxption is frequently used for water purification applications. ContaminaIJts are
adsorbed onto granular activated cmbon (GAC) as ground v.mer is passed through a filter bed. GAC.is well
suited for removal ofVOCs.
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The key parameter for GAC adsorption is the carbon requirement. TeE, and other VOCs, once adsoxbed,
remain m the carlxm. Eventually, all adsorption sites on the GAC would be filled with molecules of the OU-2
contaminants, saturating the carbon bed. Breakthrough would occur when contaminants passed through the GAC
filter bed unadsorbed. Nonnally, two GAC vessels are used m series to ensure adequate treatment after there is
breakthrough m the first column.
Adsorption can occur as long as the concentration ofTCE (and other VOCs) at the surfuce of the carbon is
less than the com:sponWng equilibrimn cnntmn1n:mt concentration in the passing liquid. Once the liquid
.,
concentration drops below the surface equilibriwn concentIation, cnnrnmin:mtJ: will not be adsOIbed. This poses'
problems m applications where the contaminaut concentration varies or declines over time, and the effluent must
be closely monitored to identify the occurrence ofbreaktbrough.
The conditions at OU-2 are such that a four-vessel system would be best suited for the desired treatmeIIt.
FoW" 1O,000-p0und capacity vessels, two in par.illel, two in series, are reconnnended to provide sufficient
treatmeDt capacity. The 700-gpm extIaction stream would be divided into two 35O-gpm streams tl1rougb two
vessels. Since injection of the treated effluent into the shallow aquifer is highly fuvored, it would be necessary
to closely ,monitor eftluent ftum the first vessel of the treatment system to detennine when replacement is
required.
The carbon requirement. is an estimate based on an assmned influent concentration. As the influent
concentration changes, the ammmt of carbon required for adsorption of COIItaminants also changes. As influent
conceni:rations decrease, the usable life of a carbon vessel can be expected to increase. Carbon adsorption
capacity varies among different suppliexs. A carbon consmnpti.on rate of ~v~oAi.warely 500 pounds of
carbonIday has been estimated for the treatment of contam;nm-ed ground water at OU-2.
The capacity of the GAC adsorption system described is approximately one million gallons per day, based
on a 700-gpm pumping rate.
As described for Alternatives IT and m, the treated effluent would be injected into the shallow aquifer using
recbazge wells. Similar monitoring of well perl'onnance would occur as described for Alternatives IT and m.
Altemative IV is protective of both hmnan health and the environment. The assessment for this altemative
is vety much like the assessment for Alternatives IT and m. This altemative would allow the MCLs for the OU-
2 contamin:mf!; to be achieved. There are no air emissions with the carbon adsmption system. Altemative IV
would also meet all other ARARs.
Umg-teDIl monitoring would be necessary to detennine the effectiveness of the system. Additional
monitoring would be required with the carbon adsorption system to detennine when breakthrough of the first
carbon vessel occurs. The additional monitoring would initially occur on a weekly basis.
Altemative IV preSents no additional short-tenn risk to the connmmity. An approved health and safety plan
would be implemented to protect worlrers v.ho might come m contact with oontaminated ground water. The
areal extent of the plwne will begin to decrease once Alternative IV is implemented. The cmcinogenic risk
36
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resulting from this alternative is 6.73~ for ingestion of 5 J.1g1'l TCE in ground water and 1.70E~ for inhalation
of TCE vapors while showering. The showering scenario assumes a TCE conceDtration of 5 J.1g1'l in grotmd
water. The tUne required to achieve MCLs in ground water (in situ) is approximately 16 years.
The carbon adsOIption system would also reduce the toxicity, mobility, and volume of OU-2 contaminants
in ground water; however, the disposal of cnntmnin:rtp4 carbon would have to be ammged through a contractor.
Carbon ads01ption has a removal efficiency of near 100% prior to breakthrough.
Carbon adsOIption is a proven technology for treatment ofVOCs and equipment is readily available.
Operators are readily available and easily 1rained. The capital cost is estimated to be $500,000 with annual
O&M costs of $700,000. O&M costs also include annual replacement of GAc.
Alternative V - Catalyzed Olemical Oxidation
Olemical oxidation refers to the chemical reaction that occun; when an oxidant, such as hydrogen peroxide,
reacts with the contaminant to reduce 1he oxidation state of the readant. In the case of TeE, a chlorinated
molecule, the reaction proceeds through a series ofintennediate steps to produce water, carbon dioxide and free
chloride ions. These residual products are oxidized states of the TCE molecule. The other OU-2 Cl1I'I1M11in:mtc:
are also effectively oxidized in 'this process.
Catalyzed chemical oxidation consists of catalyzing ultraviolet (UV) radiation and chemical oxidation using
hydrogen peroxide. The combination induces:rapid photochemical oxidation of halogenated oxganic compounds.
The process takes place in a UV/oxidation reactor operated on a continuous-flow basis. A 400-600 kilowatt
reactor is reconnnended.
As described in Alternatives II, m and IV, 1he 1reaIed eftluent would be injected into the shallow aquifer
using rechazge wells. The treatment system proposed in Altemative V would be monitored. Well perfonnance
would be evaluated as in Alternatives -II, III, aud IV.
Catalyzed chemical oxidation can provide protection to human health and the enviromneot since it
essentially destroys TCE on-site, and does not generate secondaIy wastes requiring fiuther treatment. For this
reason, it is very effective in reducing toxicity, mobility, and volume of co.otaminants. Catalyzed chemical
oxidation has the capability to reduce toxic levels of TCE in ground water to the MCL. The carcinogenic risk
resulting from this alternative is 6. 73~ for ingestion of 5 J.1g1'l TCE in ground water and 1. 70E~ for inhalation
of TCE vapors while showering. The showering scenario assumes a TCE concentration of 5 J.1g1'l in ground
water. . There are no contaminated air emissions with the chemical oxidation system. Alternative V would also
meet all other ARARs. The chemical oxidation process system is readily implemented since it ~ portable and
requires no extensive design. .
There are no additional short-teml risks to the cnmrmmity ~ the implementation of Altemative V.
Protection of WOIkers who may come in contact with contaminated ground water will be afforded through the
implementation of an approved health and safety plan. The areal extent of the plume would decrease once the .
37
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treatment system proposed in Altemative V was opernble and would take approximately 16 years for ground
water cleanup standards (MCLs) to be met.
The equipment for catalyzed chemical oxidation can be readily obtained fium commercial vendors. More
specialized opeI3tor training is required for Alternative V than for the other alternatives. Addition of specific
doses of chemicals is required for this alternative. h is estimated that capital costs, which includes the initial
purchase of the equipment and installation, are $500,000. h is estimated that O&M costs are $340,000 per year.
VllI. . SUMMARY OF COMPARATIVE ANALYSIS OF AL1ERNATIVES
The five alternatives presented in Section vn are evaluated below in relation to one another for each of the
evaluation criteria. This analysis will identify the advantages and disadvantages of each alternative. Table 4 is a
summaxy of the comparative analysis.
A Protection ofHmnan Health and the Fnviromnent
Overall protection of hmnan health and the enVironment addresses whether an alternative provides adequate
protection from exposure to cant.amination and descn"bes how risks for the exposure pathways are e1imin~p.d or
reduced.
The no-action alternative would not provide any protection from exposure to ground water mrmunirurtion at
OU-2 and there would be no reduction of OU-2 associated risk.' Altemative I would not actively e1iminat.e or
reduce risks posed by ground water contamination and could result in the contamination spreading. Ground
water monitoring would measure the effects of possible natural processes such as degradation and aUenuation;
however, these processes are uncertain and provide virtually no protection against existing risks.
A1tematives II, III, IV and V, through the use of engineering controls (in the fom1 of a ground water
extraction and treatment system) would protect against the spread of contaminated ground water and reduce the
risk of exposure. The treatment method selected will allow clean-up of the in situ ground water to comply with
ARARs.
B. Compliance with ARARs
Section l21(d) of the CERCLA, 42 U.S.c. Section 9621(d), requires that remedial actions selected under
CERCLA attain a level or standard of control of the hazardous substances at a site or operable unit which
complies with "applicable or relevant and appropriate requirements" (ARARs). ARARs are derived from federal
and more stringent state enviromneIJtal and fucility siting laws that have been identified by the state in a timely
mmmer.
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"Applicable" requirements are those cleanup standards, standards of control, and other substantive
requirements or limitations that have been promulgated under federal or state environmental and fuci1ity siting
laws that specifically address a hazardous substance, pollutant or contaminant, remedial action or other
circumstance at a particular CERCLA site or operable unit. "Relevant and appropriate" requirements are cleanup
standards, standards of control and other substantive environmenml proteCtiOll requirements, criteria, or
limitations promulgated under federal or state law that, mwe not directly applicable 10 a hazardous substance,
pollutant or cnnt:mtin:mt, remedial location or other circumstance at a CERCLA site or ope13ble unit, address .
problettlS or situations sufficiently similar to those encountered at the particular site or operable unit that their use
is well suited to the particular site. If an ARAR is detemrlned to be insufficient to protect human health or the
environment, non-prnmn1vtPil advisories or guidance (fo Be Considered or 1BCs)may be used in detennining
the necessazy cleanup level for protection of hmnan health or the environment.
There are three categories of ARARs or 1BCs: (1) chemical-speci:fic, (2) action-specific and (3) location-
specific. OJemical-speci:fic ARARs and 'IBCs are limits on concentrnti.ons of specific hazardous substances, .
pollutants or COJIIaminants in the enviromnent. Examples of this type of requirement are drinking water
standards and ambient water quality criteria. Action-speci:fic ARARs and 'IBCs. are restrictions ~ are triggered
by a particular type of activity at a site or operable unit, such as Resource ConseIVation and Recovery Act
(RCRA) regulations regarding hazardous waste treatment, storage or disposal. I.ocation-specific ARARs or
1BCs are restrictions on certain tYPes of activities based on the location of the Site or operable unit. These
include restrictions on activities in wetlands, floodplains and historic areas.
A detailed analysis of ARARs for this ROD is presented in Tables 5-A and 5-B. A partial narrative
description of ARARs follows.
Olemical-SDecific ARARs
A total of 10 contaminants were identified for evaluation in the risk assessment (see Section VI "Summary
ofOU-2 Risks"). The combined risk from these contanrlnants exceeded EPA'sacceptable risk range (i.e., l.0)!
to 1.0E ~ for all exposure pathways. Additionally, three of these contamina11ts (ICE, t.et:racb1oroethylene, and
benzene) exceed their respective federal or state MCLs (fables 5-A and 5-B) and present an uoacceptable ~ to
. .
human health.
The State has asserred that TItle 23 of the CCR, Division 3, O1apter 15, Article 5 is an ARAR for this site
requiring clean-up of the aquifer to background unless it is technologically or economically infeasible to do so.
All parties to 1he FFA have not agreed that Olapter 15 is an ARAR in this case. Therefore, the contaminant
specific ARARs for the OU-2 aquifer clean-up are the Federal or more stringent State of Califomia ~
water standaJds because the site or operable units ground water is a potential source of drinking water. The
aquifer clean-up levels for theconstitueDts of concern are therefore established at the following levels: TeE,
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Sppb (federal MCL); PCB, 5 ppb (fedeIal MCL); and benzene, 1 ppb (state MCL). The Air Force agrees to
conduct studies to assess the teclmical and economic feasJ.1>ility of achieving background (at the analytical
detection limit of 0.5 ppb for TCE), the one-in- Parts 144 and 146. (2) Section 3020 of the Resource Conservation and Recovery Act, and
(3) the substantive portions of State Water Resoun:es Control Board (SWRCB) Resolution No. 68-16 "Statement
of Policy with Respect to MIDnminn,g High Quality of Waters in Califomia".
Section 3020 of the Resource Conservation and Recovexy Act (RCRA) prohibits disposal of hazardoUs
waste above or into a fonnation that contains an 1mdeIground somce of drinlcing water. This prohibition does
not apply to injection of treated ~ ground water into the same aquifer ftom whiCh it was withdrawn if
(1) such injection is part of a response action under CERCLA, (2) the contamiDated ground water is treated to
substamially reduce hazardous substances prior to such injection, and (3) the response action will upon
completion, be adequate to protect hmnan health and the environment.
The fedezal Undezground Injection Control (VIe) Program requires that injection wells, such.as those that
would be located at OU-2, do not cause a violation of primaIy MQ.s in the receiving acjuifer. and do not
adversely affect the health ofpersons (40 C.F.R Section 144.12).
Additionally, according to the decision of the EPA Administrator, Resolution 68-16, the water anti-
degradation policy, is a state ARAR for the establishment of mnnericalIimits for the reinjection of treated
groundwater into clean areas (i.e., high quality waters) of the aquifer, i.e., outside of the cnnfamimlted phnne.
The mnnericallimits established on a monthly median and on a daily maximum basis to meet the requirements
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of Resolution 68-16 are set forth in Table 5-C. Wrth respect to the renyection of1reated groundwater within the
contaminated plume, 1reatment shall be at least to the concentration level of the substance being regulated in the
grouruhvater at the point of reinjection measured on a monthly median basis, but not greater than the more
stringent of the federal or the state primary MCL, also set forth in Table 5-C. To meet the requirement that the
selected remedy be protective of human health and the enviromnent. the Air Foree shall maintain hydraulic
control of the plume vArile extracting conf;m1in~ groundwater, and reinjecting treated ground water into the
COIItaminant plume or the clean portion of the aquifer.
It is believed that the remedy selected will clean the reinjecred water to the selected clean-up standards.
Additionally, in response to State concerns regarding the adequacy of current metals data for OU-2, the Air Force
has agreed to perfonn metals and minerals monitoring. If the results necessitate the estabIislnnent of reinjection
standards for additional constituents in order to meet Resolution 68-16, an amendment to the ROD, inclusion in
the Comprehensive Base-\\ide ROD, or other appropriate procedural medmnim1 , will be considered by the
parties.
CaIbon AdsomQon
Use of activated CaIbon for organics in the liquid1>hase trealment (for Alternative IV) and in treatment of the
off-gases from the air stripper (for Alternatives n and Ill) to mitigate poteiItial air emissions, could trigger
California Hazardous Waste Control Act (HWCA) (the federn]ly delegated state RCRA program) requirements
associated with treatment, stomge, regeneration and disposal of the spent carbon. v.hich is regulated as a
hazardous waste under HWCA, CCR TItle 22. Transportation and storage of hazardous waste for recycling must
comply with requirements of HWCA (CCR TItle 22). The selected remedy (Alternative D) will utilize off-slte
thennal regeneration (i.e., recycling) of the spent carbon from the air stripper. The spent carlxm will be
transported to a thennal regeneration fiIcility by a vendor licensed by the State of Califomia. Since the selected
remedy does not contemplate on-site disposal of hazardous or remedial action derived wastes, no such action
specific ARARs were selected. Hazardous and remedial action derived wastes could consist of wastewater,
screenings, sludges and other solids geneIated during ccmst:roction, operation and maintenance of the treatment
system. Off-site disposal of such wastes will be performed in accordance with applicable federal., state and local
laws, regulations and ordinances. However, these requirements would not be considered ARARs under
CER.CLA, as ARARs apply only to on-site activities.
Additionally, carbon adsoIption of the off-gasses from the air stripper will mitigate VOC releases to the
atmosphere, thereby meeting, inter alia, the requirement of the San Joaquin Valley Unified Air Pollution Control
District (RDle 2201) to use best available control technology.
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groundwater into clean areas (i.e., high quality waters) of the aquifer, i.e., outside of the contaminated plume.
The numerical limits established on a monthly median and on a daily maximum basis to meet the requirements
of Resolution 68-16 are set forth in Table SOC. With respect to the reinjection of treated groundwater within the
~ntaminated plume, treatment shall be at least to the CODCCDttatiOD level of the substance being regulated in the
groundwater at the point of reinjection measured on a monthly median basis, but iIot peater than the more
stringent of the federal or the state primary MCL, also set forth in Table S-C. To meet the requirement that the
selected remedy be protective of human health and the environment, the Air Force shall maintain hydraulic
control of the plume while extracting comaminated groundwater, and reinjecting treated ground water into the
contaminant plume or the. clean portion of the aquifer.
It is believed that the remedy selected will clean the reinjected water to the selected clean-up standards.
Additionally, in JaPODSC 10 State concerns regarding the adequacy of current metals data for OU-2, the Air
Force has agreed to perform metals and mmerW monitoring. If tbe results necessitate the establishment of
reinjection standards for additional constituents in order to meet Rcsolu1ion 68-16, an amendment to the ROD,
inclusion j,n the Comprehensive Base-wide ROD. or other appropriate procedural mechanism, will be considered
by the parties.
Carbon Adsonrtion
Use of activated carbon for organics in the liquid-phase treatment (for Alternative IV) and in treatment of the
off-gases from the air stripper (for Alternatives n and III) to mitigate potential air emissions, could trigger
California Hazardous Was~e Control Act (HWCA) (the federally delegated state RCRA program) requirements
associated with treatment, storage, rcgeoeration and disposal of the spent carbon, which is regulated as a
hazardous waste under HWCA, CCR Title 22. Transportation and storage of hazardous waste for recycling
must comply with requirements of HWCA (CCR Tide 22). The selected remedy (Alternative II) will utilize
off-site thermal regeneration (i.e., recycling) of the: spent carbon from the air stripper. Tbe spent carbon will
be transported to a thermal regeneration facility by a vendor licensed by the State of California. Since the
selected remedy does not contemplate on-site disposal of hazardous or remedial action derived wastes, no such
action specific ARARa were selected. Hazardous and mnedial action derived wastes could consist of
wastewater, screenings, sludges and other solids generated during construction, operation and maintenance of
the treatment system. Off-site disposal of such wastes will be performed in accordance with applicable federal,
. . .
state and local laws, regulations and ordinances. However, these requirements would DOt be considered ARARa
under CERCLA. as ARARs apply only to on-site activities.
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Location Specific ARARs
h is known that the Base is in the historical range of several endangered and/or threatened species (Figure
4). In the absence of a fimlli"ed study to detennine the absence or presence of these species, it will be assmned.
that they do exist at OU-2. The Fndangered Species Act is an ARAR.
Similarly, there is an effort currently undetway to detennine v.hether or not jwisdictional wetlands exist at
Castle AFB. PrelinrlnaIy indications are that wetlands do exist at Castle AFB, however, none have been
identi1ied in the OU-2 area.
The constIUction and operation of the OU-2 treatment fucility will occur in a manner which will not have
an adverse impact on endangered species should they exist. Evety reasonable effort will be made to ensure that
any resource areas are left in an undistutbed state throughout and following the remedial activi1ies. Should this
not be possible, a mitigation plan will be developed in consultation with EPA and the U.S. Fish and Wildlife
Service.
~
c. Long-:renn Effectiveness and Pennanence
Long-tenn effectiveness and pennanence refers to the ability of a remedy to maintain reliable protection of
human health and the environment over time. This criterion includes the considerntion of residual risk and the
adequacy and reliability of controls after implementation of the remedy. The residual risk, or risk remaimng
after completion of the cleanup, is the same for all of the altematives, with the exception of the "No Action"
Alt.emative and Alternative I. The treatment standards are the same for all altematives. The residual risk for
TCE at the cleanup standard of 5 ppb is approximately 1. m-s for showering and 6.7E -7 for ingestion. Other
VOC contamin:mt~ are present, concepttations of which would be reduced to MCLs during the cleanup of TCE .
to 5 flg/l.
Long-tenn effectiveness is also measured by the adequacy of controls. Alternatives n through V would
have the greatest ability to maintain reliable protection of hmnan health and the environment over time because
active measures are used under these a1tematives to control the spread of contamination and to restore the
aquifer. All altematives under consideration include grmmd water monitoring.
Alternatives n, Ill, IV, and V provide high degrees of long-tenn effectiveness and pennanence since each
treats the ground water to reduce hazardous concentIations ofVOCs to drinking water standards. Altematives n,
Ill, and IV would be effective in treating all of the chemicals of concern listed in Table 2. OUQrofonn and
chloromethane may pose a problem for Alternative V; however, the effectiveness of Alternative V in treating
those compounds would be evaluated in the design phase. Some long-tenn maintenance and ground water
monitoring would be required for each altemative until the health-based cleanup standards for ground water have
been met, at which point monitoring could be reduced. Alternative I relies solely on institutional controls to
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prevent exposure. The institutional controls would prevent the instaUa1ion of new wells and, thereby, the
ingestion of contaminated ground ~r. However, it is questionable whether such controls would be effective
with a high degree of certainty for more than 5 to 10 years. Also with Base closure in 1995, the future
disposi1ion of the land is questionable.
A1tema1ive I also has long-temJ. ground water monitoring requirements. Monitoring will continue UJJtil the
health-based cleanup standards (fables 1 and 2) are met, much would not occur for an estimated 50 years
(RI/FS for OU-2;January 1992).
D. Reduction of Toxicity, MObility, or Volmne through Trea1ment
Reduction of toxicity, mobility, or volmne through treatment refers to 1be preference for a remedy that uses
treatment to reduce health hazards, contaminant migration, or the quantity of the c;nntMnin:mt<: at the Site or
operable unit. Neither the no-action altemative nor Altemative I use treatment and do not satisfY this criterion;
all of the contaminated ground water would remain, although the contaminants in the ground water would
potentially,attenuate naturally.
A1tema1ives n, Ill, N and V use treatment teclmo1ogies to reduce the hazard posed by the TCE (and VOC)
contaminated ground water. Each alremative treats the clmricals of concem to drinking water standards.
Regeneration of the carbon in Altemative II ultimately destroys the TCE. These four altema1ives would satisfY
the statutory preference for treatment as a principal element.
E. Short-Tenn Effectiveness
Short-tenn effectiveness refers to. the period of time needed to complete the remedy and to prevent adverse
impacts on hmnan health and the enviromnent that may be posed dming constroction and implementation of the
remedy. Since a complete health and safety plan would be completed prior to the implementation of the
remedies, short-tenn adverse Unpacts dming constroction of the remedies would be minimized. Altematives II
through V are all estimated to reduce in situ ground water contamination to MCL levels in 16 years. .
The no-action a1tema1ive and A1temative I present the greatest risk to the conmnmity and the enviromneDt
since further migration of the plmne is not prevented. Therefore, a greater area would be impacted by the
contanlination.
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F. Implementability
Implementability refers to the technical and administrative feasibility of a remedy, including the availability
of materials and services needed to implement the selected remedy. h also includes coordination of Fedeml,
State and local govemmems in cleanup of the Site or operable unit.
The no-action altemative and Alternative I would be the easiest to implement since monitoring wells have
been installed and are periodically monitored at OU-2. .
Alternatives n and IV would be the next easiest to implement since both use proven technologies that are
readily obtained and can be constructed in the area of OU-2. If additional contaminants are fmmd at OD-2, the
components of either altemative can be sized to include the additional requirements.
,
Alternatives ill and V are som~ more difficult to implement. Altema1ive ill uses some non-routine and
specialized materials and equipment and specialized operator tr.Uning is required. Alternative V uses proven
technologies that are readily obtained and constructed in the area of OU-2; however, non-routine and specialized
operator 1Iai.ning may be required. The operator tr.Uning required for Altematives ill and V is more specialized
than that ~ for Alternatives n and IV. A1temative ill requires the use of high-pressure ~ and
Altema1ive V requires specific doses of chemicals as compared to primarily mechanical systems for Alternatives
n and IV.
~
G. Cost
This criterion examines the estimated costs for each remedial altemative. For comparison, capital costs and
annual O&M costs are used to calculate a total net present worth cost for each a1temative. The no-action
a1temative is not discussed in detail in this section because it requires no action and therefore no costs other than
costs for monitoring existing wells. ..
Individual cost estimates for each of the altematives are also the result of an accumulation of vendor
infonnation and engineering judgment. The costs assmne that 6 aquifer volmnes would be treated over 16 years.
The costs assmne a materials discount rate of six percent. Costs developed here are for comparison purposes
only. ActuaI costs developed after finther study and design may be substantially different; however, the re~
relationship of the costs will remain the same. WIth the exception of the "No Action" Altemative and
Alternative I, the least expensive treatment: altemative is Alternative n with a present worth cost of $3,200,000, .
while the most costly is Alternative llI, at $9,300,000 (Table 4).
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H State Acceptance
State acceptance indicates whether, based on a State's review of the RIfFS and Proposed Plan, the State
agrees with the preferred alternative.
The parties to the FFA for Castle AFB (Le., US EPA, Cal-EPA's DTSC, and the US Air Force) have all
been involved in the selection of the remedy. Based on the present database, the State agrees in concept with the
selected remedy for OU-2.
Also, the State supports injection of the treated ,effiuent, but is concemed when uyection takes place directly
back into the plume. The injection increases the likelihood that the hydraulic control of the plume will not be
achieved and that spreading of the contaminant will occur. This will be fully addressed in the remedial design
phase.
The State has also requested that this ROD connnit the Air Force to undertake additional characterization,
as necessaIy, for the design of the remedial system, including the extraction and injection wells. This additional
investigative effort will iDclude further characterization of the extent of con:taminati.on to more carefully
detennine the plume boundaries and water quality characteristics. This effort shall also include additional
monitoring wells both on and off the Base. The design of the remedy will consider a phased implementation of
. the treatment system. The overall project schedule will balance investigation and remediation priorities to assist
the Air Force in expediting reuse of the OU-2 part of the closing Air Force Base. EPA and the State will "WOIic
with the Air Force to streamline the teclmica1 and administmtive requirements to enable the development of an
expeditious overall project schedule.
I. Connmmity Acceptance
. The Air Force has solicited input from the conmnmity on the alternatives evaluated for OU-2. No
commentor expressed disagreement with the preferred alterative. A response to these comments is provided in
.Attachment B.
IX. SELECIED REMEDY
Five alternative remedial actions (and the no-action alternative) were investigated in detail for the 1reatment
of the contaminated ground water at OU-2.
No-Action Alternative
Altemative I - InstitutiOnal Controls
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',,,";'~';,:~::....:'...... .,
AltelIlative II - Packed Tower Air Stripping
AltemaIive m . Steam Stripping
Alternative IV . Carbon Adsorption
Alternative V - Catalyzed Chemical Oxiclation
Based on the evaluation of Ihe six alternatives and consideration of Ihe nine criteria, Alterative n. is
selected. This selection is based on operability. degree of treatment, handling of treatment residues. md
.e.xpected COSfs. The selected remedy "requirc.s additional OU.2 plume defiJ1ition, water quality cbaracterization
of the plume and the pOtential receiving watcr of the treatment system effluent, and hydrological aquifer
characterization. The Air Force has developed a detailed scope of work for completion of clwacterization of
all aquifers. Thc KOpe of work will be the basis for the Ume schedule. Based on further data collection,
phased implementatioD of the desigD will be considered.
, Alternative III will be difficult 10 implement since there may not be a steam supply that is readily available
and specialized operator training is required. The expected cost also makes this alternative prohibitive.
Although Alternative IV can provide a higher degree of removal of TCE from ground water, the spent
c~ must either be regenerated or handled and disposed of as hazardous waste. Furthermore, activared
carbon has a finite life and requires close monitOring to determine when replacement is required. Unlike the
stripping tower. the performance of the activated carbon will be affected by other dissolved cont!lminlnts, and
the adaorption capacity may not perform coDsistendy over the life of the Carbon as adsozption sites become
occupied by contaminant molecules. "
While the technologies used in Alternative V are readily available, specialized operator training may be
required. The performance of the. chemical oxidation treatment system will be affected by other undefined
contamination that may be present at OU-2. An assumption made in the development and Kreening of the
alternatives is that the primary chcmiea1 of concern is TCE. Although Other volatile organic compounds have
been detected in OU-2, TCE is considered to be the most prevalent and mobile of the contaminanu. The
currently operating removal action in the DA-4 and Wallace Road areas will be coasiden:d during the
prqlaration of the OU-2 remedial design.
.Ground Water Extraction and Tn:atment System
Ground water wiJI be extracted using multiple extraction wells. Four extraction wells are cw:rently in
place as part of the Ca.ule AFB's ongoing removal action. The exact location, number and pumpiq rates of
any additional remedial action extraCtion weIls, as weJl as a deCision on the long-term use of the CWTeDt
removal action extraction wells, will be addressed during the dcsilU of the remedial around water rccovel)'
aystem. Recovered ground water will be treated un...ite using an air stripper system with ictivated carbon
48
01'd VOO'ON 10:11
£6'Ot fION
0£V~-9~l-60~-1:131
8~~ 311S~J A3J/S3J £6
-------
Alternative n - Packed Tower Air Stripping
Alternative m - Steam Stripping
Alternative IV - Qubon Adsorption
Alternative V - Catalyzed O1emical Oxidation
Based on the evaluation of the six a1tematives and consideration of the nine criteria, Alterative n is
selected. This selection is based on opexability, degree of treatment, h:mrlliT\g oftrealment residues, and expe~
costs. The selected remedy requires additional OU-2 plmne definition, water quality cbaracterization of the
plmne and the potential receiving water of the treatment system effiuent, and hydrological aquifer
characterization. The Air Force has developed a detailed scope of WOIk for completion of characterization of all
aquifers. The scope of WOIk will be the basis for the time schedule. Based on further data collection, phased
implementation of the design will be considered.
Alternative m will be difficult to implement since there may not be a steam supply that is readily available
and specialized operntor training is required. The expected cost also makes this alternative prohibitive.
Although Alternative IV can provide a higher degree of removal ofTCE from ground water,. the spent
cmbon must either be regenerated or bandIed and disposed of as hazan:lous waste. Furt:hennore, activated cmbon
has a finite life and requires close monitoring to detennine when replacement is required. Unlike the stripping
tower, the perfonnance of the activated carbon will be affected by other dissolved contaminants, and the
adsorption capacity may not perfonn consistently over the life of the carbon as adsorption sites become occupied
by co.rrtamin:mt molecules.'-
While the teclmologies used in Alternative V are readily available, specialized operator training may be
required. The perfonnance of the chemical oxidation treatment system will be affected by other undefined
contamination that may be present at OU-2. An assumption made in the development and screening of the
alternatives is that the primmy chemical of concern is TCE. Although other volatile OIgaDic compounds have
been detected in OU-2, TCE is consideredto be the most prevalent and mobile of the cormmrin:mt~. The
cmrently operating removal action in the DA-4 and Wallace Road ateaS{Will be mcolpOratedinto-the-QU-2- .-
~...:I;~1 ~ will be considered dming the prepaI3tion of the OU-2 remedial design.
Ground Water Extraction and Treatment Svstem
Ground water will be extracted using multiple extraction wells. Four extraction wells are t(UD'ently in place
as part of the Castle AFB's ongoing removal action. The exact location, nmnber and pumping rates Of any
additional remedial action extraction wells, as well as a decision on the long-tenn use of the cun:ent removal
action extIaction wenS, will be addressed dming the design of the remedial ground water recovexy system.
Recovered ground water will be treated on-site using an air stripper system with activated carlxm treatment of the
46
-------
. contamination that may be present at OU-2. An assumption made in the development and screening of the
alternatives is that the primary chemical of concern is TCE. Although other volatile organic compounds have
been detected in OU-2, TeE is considered to be the most prevalent and mobile of the contanUnants. The
currently operating removal action in the DA-4 and Wallace Road areas will be considered during the
preparation of the OU-2 remedial design. .
Ground Water Extraction and Treatment SYstem
.. .
Ground water will be extracted using multiple extraction wells. Four extraction wells are currently in
place as part of the Castle AFB's ongoing removal action. The eXact location, number and pumping rates of
any additional remedial action extraction wells, as well as a decision on the long-term use of the current
removal action extraction wells, will be addressed during the design of the remedial ground water recovery
system. Recovered ground water will be treated on-site using an air stripper system with activated carbon
treatment of the off-gases. Additional monitoring wells are needed to verify and further define the OU-2
contaminant plume. Final flow rates and treatment unit dimensions will be determined during the remedial
design. =The treated effluent will be injected back into the subsurface through injection wells constructed as part
of the remedial action.
Moreover, the selected remedy (1) does not contemplate discharge to surface waters, and such discharge is
prohibited, and (2) prohibits the bypass or overflow of untreated or partially treated waste. The Remedial
Design and the Remedial Action Work Plan will provide for alternative discharge options in the event the
reinjection capacity becomes insufficient to handle the treated effluent. These alternative discharge options will
be used only on a temporary basis.
CleanuD Standards for Ground Water
The aquifer cleanup standards (MCLs) arc set forth in Tables S-A and S-D. The selected remedy, when
complete, will have reduced the concentrations of contaminants in ground water to the cleanup standards,
thereby satisfying the chemical-specific ARARs for aquifer cleanup (Federal Or State MCLs, whichever is more
stringent). In addition, during remediation, this remedy will meet chemical and action-specifIC ARARs, as
presen~ in Tables S-A, S-D, and S-C for discharging the treated water, into the aquifer by injection.
Ground Water Remedv ImDlemcntation
The detailed implementation of the selected remedial action will be performed by the Air Force in
consultation with the regulatory agencies during the RD/RA phase, at which time the Air Force will develop
48
GO'd SIO'ON 60:£I
£6 '-0 I "ON
O£PG-9Gl-60G-t:131
a~~ 311S~J A3J/S3J £E
-------
-; ------------ -------
off-gases. Additional monitoring wells are needed to verify and further define the OU-2 contaminant plmne.
Fmal flow rates and treatment unit dimensions will be detennined during the remedial design. The treated
effluent will be injected back into the subsurfuce through injection wells constructed as part of the remedial
action.
Moreover, the selected remedy (1) does not contemplate dischaIge to surfuce warers, and such discbaIge is
prohibited, and (2) prohibits the bypass or overflow of untreated or partially treated waste. The Remedial Design
and the Remedial Action WOIk Plan will provide for alternative discharge optioris in the event of an emergency..
A
Oeanuo Standards for Ground Water
The aquifer cleanup standards (MCLs) are set forth in Tables S-A and S-B. The selected remedy, when
complete, will have reduced the concentrations of contaminants in ground water to the cleanup standards, thereby
satisfying the chemical-specific ARARs for aquifer cleanup (Federal or State MCLs, vmichever is more
stringent). In addition, during remediation, 1his remedy will meet chemical and action-specific ARARs, as
presented in Tables S-A, S-B, and S-C for discharging the treated water into the aquifer by injection.
Ground Water Remedv Imolementation
The detailed implementation of the selected remedial action will be perfonned by the Air Force in
consultation with the regulatory agencies during the RDIRA phase, at vmich time the Air Force will develop
reporting, notification and monitoring programs. The monitoring program sbal1 include sufficient monitoring
(both in tenns of frequency and test methods employed) to evaluate the effectiveness of the remedial action and .
ensw-e that the effluent reiJ;1jection Standards adopted herein are being met. The Air Force sball, at a minimum,
include the following in the RDIRA phase: Locations of the extraction, injection and perfonnance monitoring
wells, estimated extraction and injection rates, proposed operational procedures, proposed contingency plan for
the extraction, treatment and injection system in the event of power outage and/or mechanical fuilure, geologic
well logs and well development data sheets for all available extraction, injection and perfonnance monitoring
wells proposed for the OU-2 Sroundwater treatment system. The operational procedures shall reflect that the
groundwater treatment system will not be operated in excess of its design capacity without the Prior approval of
the regulatory agencies.
Phased implementation of the remedy may be necessary to assure adequate evaluation and placement of
extraction and injection wells. An operation and maintenance plan for the ground water extIaction and treatment
system will be carefully monitored on a regular basis and the system may be modified (including the installation
of additional monitoring wells) as wammted by the perfonnance data collected during its operation upon
agreement of the parties to the Federal Facilit.y Agreement.
47
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X STA11JTORY DE1ERMINATIONS
The selected remedy is protective ofhmnan health and the enviromnent as required by Section 121 of
CERClA The selected remedial action, when complete, will comply with applicable or relevant and app!opriate
enviromnental standat:ds established under Federal and State enviromnental facility siting laws. The selected
remedy is cost-effective, uses pennanent 1reatmeDt teclmologies to the maximmn extent pI3Cti.cable and includes,
treatment as a principal element. The followiDg sections discuss how the selected remedy for OU-2 meets the
statutory requirements.
..
Protection of Public Health and the Enviromnent
Attainment of clean-up standards will assure that the levels of the chemicals of concern in the. ground water
at OU-2 will not exceed drinking water standards. Alternative II uses engineering controls in the fonn of a
ground ~r extraction treatment system to remove contaminated ground water from the aquifer:. The extraction
of contaminated ground water will significantly reduce the threat of exposure to residents. The implementation
of this remedy will not create any short-tenn risks nor any negative cross-media impacts.
Attaimnent of ARARs
. All ARARs will be met by the selected remedy. The remedY will achieve compliance with chemical-
specific ARARs by treating ground water to concentrations at or below the chemical-specific cleanup standards.
Action-specifi.c ARARs will be met fQr the injection of ground water. RCRA requirements will be met for the
treatment :facility, and stoI3ge and hJUldliTlf of spent carlxm. Air emission control requirements will be satisfied
. .
by use of activated caIbon.
Coot Effectiveness
EP A, the Air Force and the State of California believe that the selected remedy fulfills the nine criteria of
. the NCP and providesovera1I effectiveness in relation to its cost. Alternative II has a capital CO$t of
approximately $340,000 and an approximate ammaI o&M cost of $290,000. The total net present valUe is
$3,200,000, based on a 16-year estimate for the time required to clean up OU-2.
48
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Use of Pennanent Solutions and Alternative Treatment Teclmolo1ries or Resource Recoverv Teclmolo1ries to the
Maximum Extent Practicable'
The selected remedy represents the maxinnnn extent to \\hi.ch pennanent solutions and treatment
technologies can be used in a cost-effective manner for the Site or operable unit. Ofthase alternatives that are
protective ofhmnan health and the enviromnent (and comply with ARARs), EPA, the Air Force, and the State of .
California have detemrined that the selected remedy provides the best balance of lang-tenn effectiveness and.
pennanence; reduction of toxicity, mobility and volume through treaImeDt; short-tenn effectiveness;
implementability and cost-effectiveness.
Preference for Treatment as a Princinal Element
Olemicals of concern in the ground water will be exb:act:ed and treated. The treatment will occur in the
capture of the VOCS by the activated carlxm ~ of the off-gasses from the air stripper. Captured
contaminants will be destroyed mren the carlxm is regeneIated for recycling or disposed of in a pennitted
hazardous waste landfill. Therefore, this remedy satisfies the statutoI)' preference for remedies that employ
treatment which pennanently and significantly reduces toxicity, mobility or volume of hazardous substances as a
principal element.
49
-------
Table 4. SUMMARY OF COMPARATIVE ANALYSIS
.
Al ternative II I Alternative IV Alternative V
Alternative I Al ternative II Steam Stripping Carbon Adsorption Catalyzed Chemical
No-action Institutional Air Stripping Oxidation
Criteria Alternative Controls
,
OVERALL PROTECTIVENESS
Hunan heal th
crotectlon
- Ground water No reduction In No reduction In Aquifer ~ing Aquifer ~ing Aquifer plII'ping Aquifer pul'f)i ng
exposure for risk. risk. will control areal will control areal will control areal will control areal
existing users extent of extent of extent of extent of
contaminant plume. contaminant clume. contaminant clume. contaminant clune.
- Ground water Likely increase In Possible Increase in Aquifer plll'ping Aquifer ~ing Aquifer ~Ing Aquifer ~Ing
exposure for risk due to plume risk due to plume will reduce will reduce will reduce wi II reduce
future users migration. migration. contaminant levels contaminant levels contaminant levels contaminant levels
and contain plume. and contain clume. and contain clume. and contain plume.
Environmental Allows continued Allows continued Continued plume Continued plume Continued plume Continued plune.
protection migration of migration of . migration is migration is migration Is migration Is
contaminant plume. contaminant plume. mitigated by mitigated by mitigated by mitigated by
extraction. extraction. extraction. extraction.
Treatment wi II Treatment wi II Treatment will Treatment will
reduce contaminant reduce contaminant reduce contaminant reduce contaminant
levels below levels. below levels below levels below
drinking water drinking water drinking water drinking water
standards. standards. standards. No standards. No
Atmospheric VOC Atmospheric VOC atmospheric VOC atmospheric VOC
emission levels emission levels emission levels. emission levels.
will be controlled will be controlled
through use of through use of
carbon. carbon.
50
.,
-------
Table 4. SUMMARY OF COMPARATIVE ANALYSIS
Al ternative III Al ternaHve IV Alternative V
Alternative I Alternative II S!elll11 Stripping Carbon Adsorption Catalyzed Chemical
No-action" Institutional Air Stripping Oxidation
Criteria Alternative Controls
COMPLIANCE WITH ARARs
Chemical-specific Will not meet Will not meet Will meet cleanup Will meet cleanup Will meet cleanup Will meet cleanup
ARARs cleanup standards cleanup standards standards. standards. standards. standards.
for aquifer or for aquifer or
drinking water. drinking water. .
location-specific Will meet location- Will meet location- Will meet locatlon- will meet Will meet locatlon- Will meet location-
ARARs specific ARARs. specific ARARs. specific ARARs. location-specific specific ARARs. specific ARARs.
ARARs.
Action-specific ARARs No action-specific lIould not meet any lIould meet air lIould meet air Would meet Would meet
ARARs. ARARs since there release standards release standards injection injection
will be no action. from air strippers and Injection requirements. Air requirements. Air
and injection requl rements. release not release not
requirements. Would meet RCRA applicable. Would applicable.
Would meet RCRA requl rements meet RCRA
reaulrements requirements
LONG-TERM EFFECTIVENESS AND PERMANENCE
Magnitude of residual
" risk
. Ground water" likely Increase In Possible Increase In Treatment will Treatment will Treatment will Treatment wi II
exposure for risk due to plume risk due to plume reduce contaminant reduce contaminant reduce" contaminant reduce contaminant
existing users movement. movement. levels to below I eve I I; to below levels to below levels to below
drinking water drinking water drinking water drinking water
standards. standards. standards. etandards.
. Ground water Likely Increase in Possible Increase In Aquifer ~Ing Aquifer p~ing Aquifer ~ing Aquifer ~Ing
exposure for risk due to plume risk due to plume will reduce will reduce will reduce will reduce
future users movement. movement. contaminant levels contaminant levels contaminant levels contaminant levels
and contain Dlume. and contain Dlune. and contain plume. and contain Dlume.
Adequacy and No controls over No controls over Aquifer ~Ing and Aquifer ~Ing and Aquifer ~Ing and Aquifer ~Ing and
re Ii ablll ty of remaining remaining air stripping offer steam stripping carbon adsorption chemical oxidation
controls contamination. No contamination. No high reliability of offer high offer high offer high
reliabil ity. reliability. controlling reli abil i ty of rellabi llty of reliabil ity of
contaml nati on. controll Ino controlling controlling
contamination. contamination. contamination.
51
"..
~"
-------
Table 4. SUMMARY OF COMPARATIVE ANALYSIS
Al ternative III Alternative IV Alternative V
AI ternatfve I - Alternative II ~team stripping carbon Adsorption Catalyzed Chemical
No-action Institutional Air Stripping Oxidation
Criteria Alternative controls
Need for 5-year Review lIould be Reviell lIould be Reviell lIould be Reviell would be Reviell lIould be Review lIould be
reviell requi red to required to ensure required to required to requi red to requi red to
determine migration adequate exposure determine degree of determine degree of determine degree of- determine degree of
of the plume. prevention measures mitigation and mitigation and mitigation and mitigation and
are being amount of amount of amount of amount of
maintained. contamination contamination contamination contamination
remaining in remaining in remaining In remaining In
aquifer. aquifer. aquifer. aquifer.
REDUCTION OF TOXICITY. MOBILITY. OR VOLUME THROUGH TREATMENT
Treatment process None. None. Aquifer pumping, Aquifer pumping, Aquifer pumping and Aquifer punping and
used air stripping in steam stripping, adsorption in 2 UV/hydrogen
packed tOiler. and and carbon air carbon adsorption peroxide chemical
carbon air emission emission control. vessels in series. oxidation.
control.
Amount destroyed or None. None. 99X of the VOCs are 99X of the VOCs are Nearly 100% of the 99% of the VOCs are
treated removed. removed. VOCs are removed removed.
from ground lIater.
Reduction of None. None. Reduction of Reduction of Reductlon.of Reduction of
toxicity, mobility, toxicity of toxicity of toxicity of toxicity of
or volume through contaminant in contaminant In contaminant in contaminant in
treatment ground water ground water ground water ground water
through treatment. through treatment. through treatment. through treatment.
Reduction of Reduction of Reduction of Reduction of
mobility and volume mobil Ity and volune mobil Ity and volume mobility and volume
through aquifer through aquifer through aqui fer through aquifer
PlJI1)ing. puyping. PlJI1)ing. PlJI11Jing.
Irreversible None. None. Irreversible. Irreversible. Reversible. Reversible.
treatment
52
...
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Table 4. SUMMARY OF COMPARATIVE ANALYSIS
Al ternative III Al ternaUve IV Alternative V
, Alternative I Al ternat Ive II S~eam Stripping Carbon Adsorption Catalyzed Chemical
No-action Institutional Air Stripping Oxidation
Criteria Alternative Controls
Type and quantity of Not applicable. Not applicable. Saturated carbon Saturated carbon Saturated carbon None.
residual remaining adsorption adsorption adsorption
after treatment cartridges will cartridgas wi II cartridges wi II
require roqulre require
regeneration or regeneration or regeneration or
disposal as disposal as disposal as
hazardous waste. hAzardous waste. hazardous waste.
Concentrated
VaC/wator mixture
will requi re
disposal as
hazardous waste or
recvcl ing.
Statutory preference Does not satisfy. Does not satisfy. Satisfies. Satisfies. Satisfies. Satisfies.
for treatment
SHORT-TERM EFFECTIVENESS
Community protection Plume likely to Plume likely to No additional risk No additional risk No additional risk No additional risk
spread and more spread and more to community in to comnunity in to conmunlty in to conmunity in
wells would be wells would be short term. short term. short term. short term.
illl!acted. illl!acted.
Worker protecti on Not applicable. Risk to workers Protection required Protaction required Protection required Protection required
during sampling against exposure to against exposure to against axposure to against exposure to
only. contaminated ground contaminated ground contaminated ground contaminated ground
water. water and Iteam. water. water and oxidizing
agents.
Environmental impacts Continued Impact Continued impact Areal extent and Areal extent and Areal extent and Areal extent and
from existing from existing contaminant levels contaminant levels contaminant levels contaminant levels
conditions. Plume conditions. Plume in plume expected In plume expected in pl~ expected In plume expected
likely to spread. likely to spread. to decrease. to decrease. to decreasi. No to decrease. No
Atmospheric Atmospheric atmospheric Impact. atmospheric Impact.
emission levels at emission levels at
allowable levels. allowable levels.
53
-------
Table 4. SUMMARY OF COMPARATIVE ANALYSIS
Al ternative III Alternative IV Alternative V
Alternative I Al ternatlve II .Steam Stripping Carbon Adsorption Catalyzed Chemical
No.action I nsti tuti ona l Air Stripping Oxidation
Criteria Alternative Controls
Time until action Is Not applicable. 50 years. 16 years. 16 years. 16 years. 16 years.
cl'IImlete
IMPLEMENTABILITY
Ability to construct Not applicable. Not applicable. Construction is Construction is Construction is Construction is
and operate very feasible. very feasible. very feasible. very feasible.
Operation is OPeration is Operat I on will Operation is
expected to require expected to require require continuing expected to require
continuing continuing monitoring and continuing
mani tori ng and ~j,itoring and carbon monitoring and
adjustment. ad ustment. regeneration. adjustment.
Ease of doing more On-going monitoring On-going monitoring Treatment plant Treatment plant Treatment plant Treatment plant
action if needed may require action may require action capacity limits capacity limits capacity limits capacity limits
and/or another and/or another additional action. additional action. additional action. additional action.
RI/FS. RI/FS.
Ability to monitor Not applicable. On-going monitoring Effluent monitoring Effluent monitoring Effluent monitoring Effluent monitoring
effectiveness program on quarterly is very feasible. is very feasible. is very feasible. is very feasible.
basis is expected to
detect plume
movement.
Ability to obtain Not applicable. No approval Need to coordinate Need to coordinate Need to coordinate Need to coordinate
approvals and necessary. with air board for with air board for with RIIOCB to with RWQCB to
coordinate with other air emissions and air emissions and inject effluent. inject effluent.
agencies RIIOCB to Inject RWQCB to inject
effluent. effluent.
Availability of Not applicable. Sal11>l i ng and Carbon from air Carbon from air Carbon from air Continuous supply
services and analytical services emission control emission control emission control 01 chemicals and UV
capacities available. No other replacement/ replacement/ replacement/ bulbs are required.
services required. regeneration regeneration regeneration
service is service is. service is
required. required; requi red.
recycling service
is required.
54
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Table 4. SUMMARY OF COMPARATIVE ANALYSIS
Alternative III Alternative IV Alternative V
Alternative I Al ternative II Steam Stripping Carbon Adsorption Catalyzed Chemical
No-action Institutional Air Stripping Oxidation
Criteria Al ternatlve, Controls
Availabil ity of Not applicable. None required. Requires readily Requires non- Requires readily Requires readily
equipment, 'available equipment routine and some available equipment available equipment
specialists, and and materials. specialized and materials. and materials.
materials Specialists are equipment and Spec! all sts are Non-routine and
readily available materials. Non- readily available spec! a I i zed
and trained. routine and and trained. training may be
specialized required.
operator training
is required.
Availabill ty of None required. None required. Air stripping Steam stripping Carbon adsorption Chemical oxidation
technologies technology readily technology readily technology readily technology readily
available. available. available. available.
COST
Capital cost Not applicable. $0 $ 340.000 $ 1.400.000 $ 500 000 $ 500 000
Annual o&M cost Not applicable. $'30000 $ 290.000 $ 780,000 $ 700.000 $ 340 000
Life Cvcle cost' Not applicable. $500 000 $3,200,000 $9,300 0006 $7.900 000 $4.000 000
a. Assumes 6 flushlngs of the aquifer over 16 years and a discount rate of 6%.
b. No capital costs for steam generation are assumed' however, there are O&M costs.
55
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Table 5-A
APPLICABLE OR RELEVANT ANO APPROPRIATE FEDERAl REOOlREHENTS HR 00-2 .
Source Standard. Requirement. Description of Standard APPlicable or Relevant Application to Selected Alternative
Criterion or and Appropriate
limitation
~ 40 C.f.R. SS 141.11 - Establishes health based Relevant and The federal f'Q. for aquifer clean-up is 5 ppb
e rln l' ter Act. .12 standards (maximum contaminant Appropriate for TCE and. 5 't for PCE. The State of
42 U.S.C. S 00 et seq.; levels (HCLs» for public California f'Q. as been selected as the
National Primary Drinking water systems; relevant and ~uifer clean-up level for benzene: the State
Water Regulations. 40 C.F.R. a~ropriate for groundwater L is 1 ppb. See Table 5-8.
Part 141 t at may become a drinking The.numerical limits set for reinjection of
water source.
treated grouna.ater into the contaminated
plume are also based on the more stringent of
federa I or state It:l.s. and are set forth on
Table SoC.
~~tion ~1f~ EPA. Secti on 7: 50 R~uires action to conserve Applicable. CArD is in the historical range of several
nger pec es Act. 16 C.F.R. Part. 402. e angered species and enda,ered species (San Joaquin Valley Kit
U.S.C. S 1531 et s~.. critlea) habitats upon whieh Fox. lderberry LO~horn Beetle and Fresno
50 C.F.R. Parts 200. 402 they depend. I nc 1 udes Kangaroo Rat). (re er to table 3-A) CArR will
consultation requirement with comply with 001 consultation requirl!lllents.
the Deoartment of Interior.
~. CCR. Title 22. Div. Applies to owners and Relevant and The spent granular act1vated carbon ooits are
1 ornla zardous Waste 4.5. th. 14. Art. 9. operators WlO store hazardous Appropriate. considered to be containers. The container
Control Act (-tK.A-). H&S Code SS 66264.170-.178 waste for more than 90 days 1n requi renents IIlIst be IIItt if the spent GfI£
containers. Covers use and units are stored on-site for more than 90
S 25100 et s:?; II)TE: The federal RCRA management of containers. days.
Hea lth and Sa ety Standards ~ograll .es delegated containment. inspections and
for Hanagenent of Hazardous the State of closure.
Waste. cm Title 22 California on August
1. 1992. ~l1ance
with the delegated
~rogrCIII under State
aw 15 a federal AJW{
and i 5 deemed to be
compliance with RCRA.
57
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Table 5-A
APPliCABLE OR RELEVANT AND APPROPRIATE FEDERAL REWIREMENTS FOR 00-2
Source Standard.. Requirement. Description of Standard ~plicable or Relevant Application to Selected Alternative
Criterion or and Appropriate
Limitation
Action S~ifiC CCR. Title 22. Div. Applies to owners ~nd Relevant and The selected remedy will utilize air stripper
ran fom a Hazardous Waste 4.5. Ch. 14. Art. 9. operators Who treat. store or Appropriate. units. which are considered to be
Control Act ("fttICA"). H&S Code SS 66264.600-.603 dispose of RCRA hazardous miscellaneous units.
waste in miscellaneous units.
S 25100 et s~.: NOTE: The federal RCRA Miscellaneous units nust be
Health and Sa ety Standards program was delegated located. designed.
for Manage«1ent of Hazardous to the State of constructed. operated
Waste. CCR Title 22 California. on August maintained and closed 1n
1. 1992. COO1)liance accordance with these
with the delegated requirements.
vrogram under State
aw is a federal ARM
and is deemed to be
compliance with RCRA.
~ U.S. EPA Guidance on Policy sets target levels for To be considered Will apply to emissions limits from air.
. . Ul nee on the the Control of Air air emissions fran Superfund adopted as a stripper 1f more stringent than substantive -".
Control of Air Enissions fl'01l missions from Air remedia 1 act i OrIS lottIere ARMs perfomance standard r~Uirements of San Joaquin Valley Unified Air
Air Strippers at Su~und Strippers at Superfund do not exist. Total VOCs are if more stringent than Po 1ution Control District.
Groundwater Sites. R Groundwater Sites. established at 15 lbs. per San Joaquin Valley
Directive 9355.0-28 OSWER Directive day. Unified Air Pollution
9355.0-28 Control District's
emissions limits.
- 40 C.F .R. Parts 144 The ule regulations prohibit Applicable. Applicability of ule r~ulations w111 be .
e r1 1ng a er. and 146. RCRA S 3020 activities that allow movement dependent on the selectlon and design of the
U.S.C. S 300h et seq.; of contaminants into retnjection wells. .
Underground 1~ect1on Contro\ underground sources of
R~\ations. 4 C.F.R. Parts drinking water lottIich mak
1 and 146: Resource result in violation of Ls or
Conservation and Recovery Act. adversely affect health.
Class IV wells are banned
S 3020 except for injection of
treated groundwater into the
same formation from lotIich it
was withdrawn as rcrt of a
CERCLA clean-un ( CRA S 3020).
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Table 5-8
APPLICABLE OR RELEVANT AND APPROPRIATE CALIFORNIA REQUIREMENTS FOR OU-2
Source Standard. Requirement. Description of Standard Applicable or Relevant Application to Selected Alternative
Criterion or aoo Appropriate
Urni tat ion
~ San Joaquin Valley The Act authori zes the APCO to Applicable The carbon treatment units to be used in the
o . rre Air Resources Unified Air Pollution set allowable emissions selected remedial action are considered BACT
Act. H&S Code !i 39000 et Control District limits. This rule. entitled by the APeD. Specific emissions limits to
seq.: cOR Title 17. Part III. ("APCO") Rule 2201 "New and Modified Stationary comply ~th this rule will be established.
Chapter 1. S60000 S 4.1 Source Review Rule" requires
NOTE: To the extent that best available control NOn:: The APeD !)erforms a screening health
technol~Y ("BACT") be used to risk assessment for groundwater clean-up
that this rule was treat of -gasses. 8rojects based on the CAPeOA Risk Assessment
adopted under the SIP. uideline.
it would be a federal
ARAR pursuant to the
federal Clean Air Act.
42 U.S.C. S 7401 et
sea.
Porter~Cologne Water Quality Table 11-2 of the This table. entitled "Ground Appl1cable The ground water body named "San Joaquin
Control Act. California Water Water ()Jalfty Control Water Bodies and their Basin" is identified as having the following
Code Section 13164. 13170. Plan ("Basin Plan.) Beneficial Uses" lists 40 beneficial uses: muncipal. and domestic.
13240. 13241 for the Central Val1ey ~round water bodies and the irrigation and stock watering.
Water ()Jal1ty Control neficial uses assigned to
Board them.
Porter-Col~ Water ()Jality Page V-I of the Water Describes the Regional Board's Applicable Provides the basis for development of the
Control Act. California Water ()Ja li ty Control Plan surveillance and monitoring ground water monitoring ~rogram that wi 11 take
Code Section 13164. 13170. ("Basin Plan") for the program for water qua l1ty place during the RD/RA ase. .
13240. 13241 Central Valley Water data.
Quality Control Board
MUlford-Carrell Air Resources San Joaquin VaHey The Act authorizes the NlCD to Applicable Emissions offsets for VOCs w1l1 be required
Act. H&S Code S 39000 et Unified Air Pollution set allowable emissions only if annual emissions from the air stripper
seq.: CCR Title 17. Part 111. Control District 11lllits. This rule. entitled exceed 10 tons/year.
Chapter 1. S 60000 ("APCO") Rule 2201 "New and Modified Stationary
S 4.2.1.4 Source Review Rule" provides
that emissions offsets are not
required for increases in
rermitted emissions of YOCs of
ess than ten tons/year.
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Table 5-C
GROOND WATER DISCHARGE TREATMENT STANDARDS
Constituent Standards for Injection into Non-Contaminated Standards for Injection in the Contaminated
Portions of the Aquifer Portions of the Aquifer Based on the more
Based on State Board Resolution 68-16 stringent of (a) MCLs (State or Federal
(Concentrations in ~/1) Whichever is more stringent) as a Daily
HaxillUll (see bel~) or (b) In Situ Grouoo.eter
Concentrations at the Point of Injection as
30-Day Hediam
(Concentrations in UQI1)
30-DaY Median Daily HaxillJJm (a) State or Federal MCLs Dally I1axillUll
Chlorobenzene, 0.5 . --
Ch loroate~ne 0.5 - --
Chlorofo . 0.5 . --
1.2-Dlchloroet~lene (Cis} 0.5 - --
Tetrachloroethy ene (PCP 0.5 . 5
Trichloroethylene (TCE> 0.5 - 5
Total Volatile Organic Constituents (VOCs)J 1.0 5~0 --
Benzene' 0.5 1.0 1
Ethyl benzene 0.5 - --
Toluene 0.5 - --
Xyl ene 0.5 - --
oH 6.5 < oH > 8.5
Nitrates 10DrB as N1trooen. or backQround of the receivinq water. whichever is Qreater.
I EPA Method 601 and 602 with a detection 1111it of 0.5 ~11 or less. If the Daily Haxirun is exceeded. an additional sill\1lle(s) ItIJst be collected and analyzed
, within the sallie IIIOnth to deInonstrate that the roonthly median has not been exceeded.
carci nogens.
a Total VOCs ",111 be the Sllll of all EPA Method 601 and 602 analysis constituents. including TCE.
:>
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61
.,
-------
Table 6.
RESULTS OF QUARTERLY GROUND WATER SAMPLING PROGRAM SUMMARY OF TCE COAICENTRATIOIo/S AT 00-2
/Lg/l
5th round
1st round 2nd round 3rd round 4 tII round <12/90-1191) 6th rcnnl
Sampl ing (7/89) (10/89) (3/90) (6190) (4-5/91)
point
440 1.3 3 JO.4 JO.4 NO --
455 .. 1.2 1.1 0.8 1.6 0.8 --
501 570 20 3900 5 600 Orv --
502 370 780 716 850 770 --
503 NO JO.3 lID ND NO --
504 NO NO ND ND NO --
505 0.8 NO JO.4 NO 1ft) --
506 3.6 3.6 6 4.4 2 --
507 2.4 3.8 4.4 3.8 JO.5 ..
.
508 33 88 100 58 76 120
509 0.9 0.8 2.2 2.2 2.5 ..
510 25 39 40 61 91 92
511 2.6 ND 3 5.9 3.7 --
512 16 25 32 35 32.6 45
513 NO 0.8 0.8 JO.3 NO ..
514 3. I 3 3.5 3.5 2 --
515 2.3 4.8 0.7 NO NO --
516 49 76 71 59 76 --
576A . - -- -- -- 9.1 17
601 NO 0.7 NO NO NO ..
602 NO 1.2 NO NO NO --
604 NO NO NO NO NO ..
701 NO NO NO NO NO -.
702 NO NO NO NO NO ..
70ZA .. -- -- 0.6 NO 6.5
703 NO NO 0.5 ND NO --
704 19 22 100 77 92 120
MIO 70 NO ND - - .. -- --
05144 270 h -- -- -- --
05161 P~ removed PIm) removed - - .- -- --
05266 220 240 - - -- .. --
..
61
-------
Table 6.
RESULTS OF QUARTERLY GROUND WATER SAMPLING PROGRAM SUMMARY OF TCE CONCENTRATIONS AT OU-2
/L9/l
5th round
1st round 2nd round 3rd round 4th round (12/90-1/91) 6th round
S~lin9 (7/89) , (10/89) (3/90) (6/90) (4-5/91)
DOint
15266 4.7 6.5 -- -- -- . -
D5482 . ND ND -- eo -- --
D5486 1.4 5 -- -- -- --
D5502" ND ND -- -- -- --
D5682 Dry ND -- -- -- . -
I ND: Not detected. I
J: Estimated value.
. Not sampled.
62
-------
Table 7.
TCE RESULTS OF PRIVATE WELLS IN WALLACE ROAD AREA
Date of
Samollna ooint collection laboratorY TCE. un/1
5144 Wa 11 ace Road. old well (domestic) 1984
:Januarv:>O UW ND
1985
:January 24 USAF 1\0
Apri 1 24 USAF ND
.. . June 19 USAF 1.7
July 8 USAF 2.7
August 6 USAF :>.8
September 10 USAF 2.8
October :> USAF 11
Decanber 9 USAF 0.9
1986
:January 10 USAF 2.1
February 4 USAF 1.4
ApriJ 2 NA ND
llay 2IJ NA 2.6
June 2!D NA :>.4
(connected to base water 1989
5144 Wal\ace Road. new we I , CdOO\es1:k) 1986
i'ij)'i'il 2 NA 20
Hay 20 NA 18.1
June 20 NA :>0
July 15 NA 56.5
August 12 NA 43.6
September 2 OIL 94.6
October 7 OIL 61.8
NovE!llber 17 NA' 61.4
December 2 NA 59.1
1987
:January 12 NA 41.1
Ju 1y 14 OIL 87.:>
september 18 APPl 96
(connected to base water) 1989
5161 Wallace Road 1985
I!eCember 9 USAF ND
1986
:Janua ry 10 USAF 5.:>
February 4 USAF 4.3
April 2 NA 9.4
Hay 20 OIL 7.8
June 20 NA 6.3
July 15 NA 11.6
August 12 OIL 15.3
September 2 OIL 41.1
October 7 OIL 28.1
November 17 NA 28.5
December 2 NA 44.2
1987
JanUary 2 NA 33.4
July 14 OIL 57.2
(connected to base water) 1989
5266 Wal\ace Road (domestic) 1985
l1eCanber 9 USAF NO
"
63
-------
Table 7.
TCE RESULTS OF PRIVATE WELLS IN WALLACE ROAD AREA
Date of
$amp] ino point collection Laboratorv TCE. uol1
1986 .
:JanUary 10 USAF NO
February 4 USAF NO
April 2 NA NO
May 20 NA 0.27
June 20 NA 0.5
Ju ly 15 NA 0.9
August 12 OIL 1.3
September 2 OIL 3.5
October 7 OIL 1.8
.. . November 17 NA 7.7
December 9 NA 6.5
1987
:JanUary 12 NA 6.5
February 10 NA 8.5
March 10 NA 12.9
Apri 1 13 NA 11.2
July 14 OIL 20.3
September 18 APPL 20
(connected to base water) 1989
5486 Wa11ace Road (dOOIestic) 1985
IJeCember 9 USAF NO
5486 Wa11ace Road (cont.) 1986
:JanUary 10 USAF NO
February 4 USAF NO
April 2 NA NO
May 20 NA <0.12
June 20 NA 0.15
July 15 NO NO
August 12 OIL NO
September 2 OIL NO
October 7 OIL NO
November 17 NA NO
December 2 NA
1987
:JanUary 12 NA NO
February 10 NA NO
:;Ch 10 NA NO
ri' 13 NA NO
(GAC filter installed. sample taken before filter) 1990
JanUary BSK NO
February 'BSK NO
March BSK 3.9
April BSK NO
May BSK 2.5
June BSK 3/9
July BSK 9.9
August BSK 35
September BSK NO
October BSK NO
November BSK 55
December BSK 41
1991
JanUary BSK 56
February B5K 53
March B5K 36
April BSK 38
May BSK 46
June BSK 43
July BSK 65
August BSK 69
September BSK 27
October BSK 70
November BSK 87
December BSK 120
64
-------
T~ble 7.
TCE RESULTS OF PRIVATE WELLS IN WALLACE ROAD AREA
Date of Laboratorv TCE. Ilnll
SamolinQ coint collection
5486 Wallace Road (cont.) 1992
:JanUary BSI: 70
Febru~ry BSK 87
March BSK 120
.AjJril BSK 210
May BSK 87
June BSK 66.5
July BSK 77
August BSK 67
September BSK 88
October BSK 64
November BSK 65
December BSK 66
1993
J;;;u.,ry BSK 60
February BSK 71
March BSK 29
.AjJril BSK 25
Hay BSK 20
June BSK 12
July BSK 12
August BSK - 19
September BSK 20
October BSK 23
November BS1( 15
December BSK 13
5489 W~llace Road (No., 2) 1987
~Ser 18 APPL NO
5502 Wall~ce Road (domestic) 1985
'DeCember 9 USAF NO
1986
:JanU~ ry 10 USAF NO
Febru~ry 4 USAF 0.5
.AjJril 2 NA NO
May 20 NA 0.34
June 20 NA <0.12
Ju ly 15 NO NO
August 12 ~L NO
September 2 ~L NO
October 7 ~L NO
November 17 NA NO
December 2 NA NO
1987
JMiij~1Y 12 NA NO
February 10 NA NO
M~rch 10 NA NO
.AjJril 13 NA NO
May NA NO
June NA NO
Julv 14 ~L NO
5502 Wa 11 ace Road (cont.) 1990
:JanU~ ry BSK 6.2
Febru~ry BSK 5.3
Harch BSK NO
.AjJril BSK 3.6
M~y BSK NO
June BSK NO
July BSK NO
August BSK NO
September BSK NO
October BSK NO
November BSK NO
December BSK NO
1991
JaiiUa ry BSK NO
February BSK NO
Harch BSK NO
April BSK NO
Hay BSK NO
June BSK NO
July BSK NO
August BSK NO
September BSK NO
October BSK NO
November BSK NO
December BSK NO
65
~
-------
Table 7.
TCE RESULTS OF PRIVATE WELLS IN WALLACE ROAD AREA
Date of
Samclino coint collection Laboratory TCE. jlgll
1992
JanUary BSK NO
February BSK NO
Harch BSK NO
April BSK NO
Hay BSK NO
June BSK NO
July BSK NO
August BSK NO
Septenber BSK NO
October BSK NO
November BSK NO
December BSK NO
5502 Wallace Road (cont.) 1993
JanUary BSK NO
February BSK NO
March BSK NO
April BSK NO
Hay BSK NO
June BSK NO.
July BSK NO
August BSK
September BSK
October BSK NO
November BSK
December BSK
NA - not avai lable.
NO - not detected.
APPL - Agriculture & Priority Pollutants Laboratories
CAL - California Ana1ytica1 Laboratory.
CWL - Ca 11 fornia Water Laboratory.
SHL - State Health Laboratory.
USAF - Brooks Ai r Force Base Laboratory.
66
-------
APPENDIX A
ADMINIS1RATIVE RECORD FllE INDEX
-------
. ..----..--.' .--... - - ... ._---._--~---
06/19/92
Administrative Record Index
Castle Air Force Base, California.
=================================================================
Document Number:
CAS-011-001
Title:
Installation Restoration Program (IRP) Phase I Review
Our Conversation, 1 Sep 92
. Author:
Stephan P. Hedrick, Capt, USAF
SGPB, Bioenvirorunental Engr.
Recipent:
HQ SAC/SGPB (Col Burnett)
Date:
09/02/83
location of Document:
Castle Air Force Base
----------------------------------------------------------------
Document Number:
CAS-011-002
Title: Phase I Installation Restoration Program (IRP) Report;
Subject Facility . .
Author:
James B. Wolfson, Snr. Engr.
CRWQCB Fre~
Recipient: Donald W. Kaiser, Lt Col, USAF
HQ 93 Combat Support Group
Date: 01/04/84
location of Document:
Castle Air Force Base
--------------------------------------------------~--------------
Document Number:
CAS-Oll-003
Title:
Author:
Minutes of Phase II IRPPre-survey Meeting
Stephen P. Hedrick, Capt, USAF
Bioenvironmental Engineer
Recipient:
93 HOSP STRAT/SG
Date:
03/05/84
-------
06/19/92
Administrative Record Index
Castle Air Force Base, California
=================================================================
Location of Document:
Castle Air Force Base
-----------------------------------------------------;-----------
Document Number:
CAS": 011-004
Title:
Environmental Health Review of the Installation Restora-
tion Program Phase II (Stag-+1) for Castle Air Force Base
Author:
Jeff Palsgaard, R.S.
Recipient: Major Pontier
HQ SAC, Offutt AFB
Date:, 07/23/84
Location of Document:
Castle Air Force Base
-----------------------------------------------------------------
Document Number:
CAS-Oll-OOS
Title:
IRP Phase II, Stage 1 Draft RepOrt Review Castle AFB, CA
(Your Ltr, 3 Jul 8S)
Author:
Donald Kaiser, Lt CoI, USAF
Base Civil Engineer-DEE\!
Recipient:
USAF HOSP/SGPB
Date:
08/13/85
Location of Document:
Castle Air. Force Base.
-----------------------------------------------------------------
Document Number:
CAS-011-006
. Title:
Author:
Castle Air Force Base Installation Restoration Program
Phase II Stage I
Jeff Palsgaard, Envr. Hlth Spc
Dept. of Hlth,. Merced .
-------
6/19/92
Administrative Record Index
Castle Air Force Base, California
==========~======================================================
Recipient:
HQ SAC/SGPB, Bioenvr. Engr.
Offutt AFB, NE
12/17/85
Date:
Location of Document:
Castle Air Force Base
-----------------------------------------------------------------
Document Number:
CAS-01l-007
Title:
IRP Phase II Stage I Draft Report Review Comments,
Castle AFB
Author:
John H. Pontier, Maj, USAF
Bioenvr. Engr. - SGPB
Recipient:
USAF OEHL/TS
Date: 08/21/85
Location of Document:
Castle Air Force Base
-----------------------------------------------------------------
Document Number:
CAS-Oll-008
Title:
EPA's final conments on both Castle Air Force Base
Phase II Stage I Confirmation/Quantification Technical
Report and Castle AFB Phase IV-A Remedial Action. Plan
- Scope of Work (SOW)
Keith Takata, SUperfund Prgm.
U.S. Envr. Prete. Agency, S.F.
Author:
Recipient:
Col David E. Volz, USAF
93 CSG - Castle AFB
01/01/86
Date:
Location of Document:
Castle AFB
-----------------------------------------------------------------
-------
06/19/92
Adrninistrati ve Record Index
Castle Air Force Base, Califonrla
=================================================================
Document Number:
Cas-011-009
Title:
Phase II Installation Restoration Program (IRP) ,
Castle AFB, CA
Ronald D. Burnett, Col, USAF
Bioenvr. Engr. - SGPB
Recipient: USAF OEHL/CV
Date: 01/04/84
Author:
Location of Document:
Castle AFB
-----------------------------------------------------------------
Document Number:
CAS-011-010
Title:
EPA 's corrments on the draft Installation Restoration
Program Phase II Confi:r:mation/Quantification Stage 2
Report for Castle AFB
Amy K. Zinpfer, Fed. Resp Sect
U. S. Envr. Prtc Agency, S . F. .
Author:
Recipient: Arthur Chan, Envr. Task Force
93 BMW/CVE; Castle AFB
Date:
11/02/87
Location of Document:
Castle AFB
-----------------------------------------------------------------
Document Number:
CAS-011-011
Castle AFB Phase II, Stage 2 Report, Response to Comnents
Submitted by U.S. EPA, Region IX
Author: U. S. EPA, Region IX
Title:
Recipient:
93 CSG/EM
Castle Air Force Base
Date 07/01/88
-------
06/19/92
Administrative Record Index
Castle Air Force Base, California
=================================================================
Location of Document:
Castle Air Force Base
----------------------------------------------------------------
. Document Number:
CAS-011-012
Title:
Roy F. Weston, Inc. follow-up on Phase II, Stage 2,
Installation Restoration Program Studies at Castle AFB
Author:
Lisa A. Hamilton, Task Mngr.
Roy F. Weston, Inc.
Recipient:
Al Petersen, Envr. Task Force
Castle Air Force Base
Date:
08/21/87
Location of Document:
Castle AFB
-----------------------------------------------------------------
Document Number: CAS-Ol1-013
Title: CA Dept. of Health Services Toxic Substances Control
Division, Northern CA Section Response Cotm1ents of
Castle AFB Phase II, Stage 2 Report .
Author:
Roy F. Weston, Inc .
".
Recipient:
93 CSG/EM
Castle Air Force Base
Date:
01/07/88
Location of Document:
Castle. Air Force Base
-----------------------------------------------------------------
Document Number: CAS-012-001
Title:
JP-4 Fuel Line Assessment for Castle Air Force Base
Author:
IT Corporation
-------
06/19/92
Administrative Record Index
Castle Air Force Base, . California
=================================================================
Recipient:
Strategic Air Conmand HQ .
Date:
05/01/88
IDeation of Document:
Castle Air Force Base
-----------------------------------------------------------------
Document Number:
CAS-012-002
Title:
Contract N62472-85-C-5239, FY-87 MCAF Project-1st Fuel
Storage Study, Castle Air Force Base, Merced, CA with
35% Subnittal Report for FY87 MCAF Project Jet Fuel
Storage at Castle AFB, Merced, CA .
R.J. Roberts, Inc.
Author:
Recipient:
93 CSG/DEE
Bldg 545, Castle AFB, CA
12/04/85
Date:
I:aocation of Document: . Castle Air Force Base
-----------------------------------------------------------------
Document Number:
CAS-012-003
Title:
Prelim:inarY Soil Investigation Report, Tank Groups 1, 2,
and 3, Castle AFB
Author:
Roy F. Weston, me.
Stockton,. CA
Recipient:
93 CSG/EM
Castle Air Force Base
Date:
11/27/85
IDeation of Document:
Castle Air Force Base
---------------------------~-------------------------------------
-------
. ._....__....._-.-..._. ..-..
06/19/92
Administrative Record Index
Castle Air Force Base, California
==========~======================================================
Document Number:
CAS~012-004
Title:
ADL Jet Fuel Storage and Dispensing Facility Vall 35%
Subnittal
Author:
Boyle Engineering Group
Fresno, CA
Recipient:
Castle Air Force Base,
Merced, CA
. Date:
10/01/87
Location of Document:
Castle Air Force Base
-----------------------------------------------------------------
Document Number:
CAS-013-001
Title:
Completion of Merced County SUrvey for Abandoned
Hazardous Waste Disposal Sites Conducted by Toxic
SUbstances Control Division of the Department of
Health Services
Thomas E. Bailey, Toxic Subst.
C1trl Di vs. Dept Hlth Serv
Author:
Recipient:
Charles Mosher, MD & Riley
Peters Acting Hlth Ofcr, Merced, CA
10/19/83
Date:
. Location of Document:
Castle Air Force Base
------------------------------------------------------~----------
Document Number:
CAS-014-001
Title: Installation Restoration Program, Phase I; Records Search
Author:
ES - Engineering Science
Recipient:
USAF - Tyndall Am, FL
Date:
10/01/83
-------
.06/19/92'
Administrative Record Index
Castle Air Force Base, California
=================================================================
. .
location of Document:
Castle Air Force Base
-----------------------------------------------------------------
Document Number:
CAS-014-002
Title:
FY-1987 MCAF Project Jet Fuel Storage
Castle AFB Contract No. N62474-85-G-5239
Author:
R. J. Roberts, Inc.
Recip~ent:
Castle Air Force Base
Merced, CA
Date:
02/11/86 .
IDeation of Document: Castle Air Force Base
-----------------------------------------------------------------
Document Number: CAS-015-001
Title: Installation Restqration Program Phase II - Confirmation/
Quantification.Stage 1. (Volume I and II)
Author:
Roy F. Weston, Inc.
West Chester , Pennsylvania.
Recipient:
castle Air Force Base, CA
Date:
11/01/85
IDeation of Document:
Castle Air Force' Base
------------------------------"-----------------------------------
Document Number:
CAS-015-002
Title:
Installation Restoration ~ogram Phase II - COnfirmation/
Quantification Stage 2. (Volume I, II, and III) .
Roy F. Weston, . Inc. .
West Chester , Pennsylvania
Author:
-------
06/19/92
Administrative Record Index
Castle Air Force Base, California
=================================================================
Recipient:
Castle Air Force Base, CA
Date:
07/01/88
Location of Docmnent:
Castle Air Force Base
-----------------------------------------------------------------
Document Number:
CAS-01S-003
Title:
Health and Safety Plan
Author: Roy F. Weston, Inc.
West Chester, Pennsylvania
Recipient:
Castle AFB, CA
Date: 10/01/86
Document Number:
CAS-01S-004
,
-----------------------------------------------------------------
Title: Draft: Installation Restoration Prog1.am Phase 2 -
Confirmation/Quantification, Stage 2 (Vols. 1, 2, 3, and 4)
Author:
Roy F. Weston, Inc.
West Chester, Pennsylvania
Recipient:
Castle Air Force Base
Merced, CA
Date:
06/01/87
Location of Document: . Castle Air Force Base
-----------------------------------------------------------------
, .
-------
06/19/92
Administrative Record Index
Castle Air Force Base, California
=================~===============================================
Title:
Document NLm1ber:
Author:
Recipient:
Date:
CAS-01S-00S
Contamination Investigating and S~ling of Transformers.
and Tanks Corrosion Control Facility, Castle AFB
Hardin Lawson Associates
Novato, CA
URS/John A. Blume & Associates
San Francisco, CA
09/06/85
. wcation of Document:
Castle Air Force Base, CA
-----------------------------------------------------------------
Title:
Document NLm1ber:
CAS-015-006
Author:
TPCA Investigation Workplan - Fire Training Area
Castle Air Force Base, CA
Kleinfelder, Inc.
Fresno, CA
93 CSG/WC
Castle Ai;r- Force Base, CA
Date: . 03/08/89
Recipient:
wcation of Document:
Castle Air Force Base
-----------------------------------------------------------------
Title:
Document NLm1ber:
CAS-015-007
Author:
Recipient:
Date:
Solid Waste Assessment (~T) Proposals,
Castle Air Force Base, CA
Kleinfelder, Inc.
Fresno, CA .
93 CSG/LGCC
Castle Air Force Base
03/08/89
-------
06/19/92
Administrative Record Index
Castle Air Force Base, California
=================================================================
Location of Document:
Castle Air Force Base, CA
---~~------------------------------------------------------------
Document Number:
CAS-OlS-008
Title:
Solid Waste Assessment Test Report - CAFB West Landfill
Zone
Author:
Kleinfelder, Inc.,
Fresno, CA
Recipient:
Castle AFB, CA
Date:
03/18/91
Location of Document: Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number:
CAS-Ol5-009
Title:
Solid Waste Assessment Test Report Castle AFB South
landfill Zone,
AUthor:
Kleinfelder, Ine.,
Fresno, CA
Recipient:
93 CSG/DEV
Castle AFB, CA
,05/14/91
Date:
Location of Document:
Castle AFB, 'CA
-------------------------------------------------------.---------
, Document Number:
CAS-OlS-OlO
Title:
Solid Waste Assessment Test Report Castle AFB Landfill 3
Author:
Kleinfelder, me .
Fresno, CA
-------
06/19/92
Administrative Record Index
Castle Air Force Base, Califo:rnia
=================================================================
Recipient:
93 CSG/DEV
Castle AFB, CA
04/19/91
. Date:
Location of Document:
Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number:
CAS-021-001
Title:
Need for TCE Removal Action at Castle AFB
Author:
Michael Work
EPA, San Francisco
Recipient:
Iayi Oyelowo
93 CSG/EM, Castle AFB
08/08/90
Date:
Location of Document:
Castle AFB
---------------------------------------------------------------"--
Document Number:
CAS-024-001
Title:
Groundwater Investigating Northeast Quadrant (Vols. 1 and
. 2)
Author:
Boyle Engineering Corp.
Fresno, CA
Recipient:
City of Atwater
Date:
05/01/88
. Location of Document:
Castle Air Force Base
----------------------------------------------------------~------
-------
06/19/92
Administrative Record Index
Castle Air Force Base, Califonria
================================================================
Document Number:
CAS-024-002
Title:
Preliminary Design Report for Production Well and Water
Main
Author:
Boyle Engineering COJ:P.
Fresno, CA
Recipient:
City of Atwater
Date:
06/01/88
Locat'ion 'of Document:
Castle Air Force Base
-----------------------------------------------------------------
Document Number:
CAS-024-003
Title:
Contract Documents for Construction of Northeast Atwater
Well and Water Main
Author:
Boyle Engineering CoJ:P.
Fresno, CA -
Recipient:
Castle Air Force Base
Merced, CA
Date:
08/08/88
Location of Document:
. ,
Castle Air Force Base
, , .
-----------------------------------------------------------------
Document Number:
CAS-024-004 -
Title:
Chemical Groundwater Quality Evaluation
Author:
Boyle Engineering COJ:P.
Fresno, CA
Recipient:
City of Atwater
Date:
01/01/87
-------
06/19/92
Administrative Record Index
castle Air Force Base, california
-----------------------------------------------------------------
-----------------------------------------------------------------
Location of Document:
Castle Air Force Base
-----------------------------------------------------------------
Document Number:
CAS-024-005
Title:
Contract Documents. for Const:ruction of Monitoring and
Test Wells
Author: Boyle Engineering Corp.
Fresno, CA
Recipient:
City of Atwater
Date:
11/01/87
Location of Document:
Castle Air Force Base
-----------------------------------------------------------------
Document Number:
CAS-024-006
Title:
Groundwater Treatment Feasibility Report for Organics
Removal from Main Base Well 1, 2, and 3
Author: Boyle Engineering Corp.
Fresno, CA
Recipient:
Castle Air Force Base, CA
Merced, CA.
Date:. 03/01/89
LocatiOn of Document:
castle Air Force Base
---------------------~-------------------------------------------
Document Number:
CAS-031-001
Title:
Progress Report - Hydrologic Evaluation (CAFE Wells 1, 2,
3, and 4)
-------
06/19/92
Adrn:ini.strati ve Record Index
Castle Air Force Base, Califo:mia
=================================================================
Author:
Gunter A. Redlin, P.E.,
Boyle Engineering Co!:p, . Fresno
Recipient:
Linda TeKrony
93 CSG/EM, Castle AFB
04/07/89
Date:
Location of Docmnent:
Castle Air Force Base
-----------------------------------------------------------------
Document Number:
CAS-033-001
Title: . Results of Laboratory Analysis of Water Sample Collected
in July 1987.
Author:
Mark V. Johnson, Hydr. Tech.
Water Resources Division
Recipient:
Maj. Burrel, Bio-Env. Engr..
Castle Air Force Base
Date:
07/19/88
Location of Document:
castle Air Force Base
-----------------------------------------------------------------
Document Number:
CAS-033-003
Title:
SOO Testing for JP-4 Pipeline
Author:
A. W. Petersen, Env. Engineer
Recipient:
Memo for Record
Date:
11/05/87
Location of Docmnent: ~ castle Air Force Base
-----------------------------------------------------------------
-------
~-_._-~- -----_.~-_.- -- - ---..---- -
06/19/92
Administrative Record Index
Castle Air Force Base, California
=================================================================
Document Number:
CAS-033-004
Title:
La1:x:>rato:ry Analysis Report and Record-Test for Volatile
Halocarbons
Author:
George Lee, USAFOEHL/SA
Brooks AFB, TX .
Recipient:
93 STRAT HOSP/SGPB
Castle AFB, CA
Date:
03/28/89
location of Document:
Castle AFB, CA
-----------------------------------------------------------~-----
DocUment Number:
CAS-033-005
Title:
PW-1, 2, 3, and 4 Volatile Organic Compound Sample
Analysis
Author:
California Water Labs
Recipient:
93 CSG/EM
Castle AFB, GA
03/15/89
Date:
location of Document:
Castle AFB 1 CA
-----------------------------------------------------------------
Document Number:
CAS-033-006
Title:
Grain Size Analysis from IT
Author:
IT Co:rporation
Martinez Office
Recipient:
Linda TeKrony
Environmental Engineer
Date:
12/21/88
-------
06/19/92
Administrative Record Index
Castle Air Force Base, California
=================================================================
I.Dcation of Document:
Castle AFB, CA
----------------------------------------------------------------~
. Document Number:
CAS-033-007
Title:
Sample Results PW-1, 2, 3, and 4-ICP Priority
Pollutant Metal and Scan and Nitrates
Author:
OEHL
Recipient:
93 CSG/EM
Castle Air Force Base
Date:
04/05/89
lDeation of Document:
Castle Air Force Base
-----------------------------------------------------------------
Document Number:
CAS-033-008
Title:
Soil Augering at the Oil/Water Separator (DA-5)
Author: John Loyd, Project Manager
Oak Ridge National LaboratoJ:Y
Recipient:
Maj Doug Brown, HQ SAC/DEPV
Offutt AFB, NE
10/14/86
Date:
I.ocation of Document:
Castle Air Force Base
. .
-----------------------------------------------------------------
Document Number:
CAS-033-009
Title:
Monitoring Well Boring logs (Deleted - Page of Site
Project Report, Doc .No. CAS-035-001)
Author:
Recipient:
-------
06/19/92
Administrative Record Index
Castle Air Force Base I Califm:nia
=============================================================
Date:
/ /
Location of Document:
-----------------------------------------------------------------
Document Number:
CAS-033-010
Title:
Results of Laboratory Analysis of Water Sample Collected
in Dec 89
Author:
California Water Labs
Modesto I CA .
Recipient:
93 STRAT HOSP/SGPB
Castl~ Air Force Base
01/03/90
Date:
Location of Document:
Castle Air Force Base
-----------------------------------------------------------------
Document Number:
CAS-034-001
Title:
Addendum Remedial Investigation/Feasibility Study Work
Plans Castle Air Force Base
Author:
IT Corporation
Martinez, CA
Recipient: Strategic Air Conrnand HQ
Offutt AFB, NE
Date:
12/01/88
Location of Document:
Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number:
CAS-034-002
Title:
Remedial Investigation/Feasibility Study for Castle Air
Force Base Volume IV: Health and Safety.Plan
-------
06/19/92
Administrative Record Index
Castle Air Force Base, California
==========7======================================================
Author: IT Corporation
Martinez, CA
Recipient:
Strategic Air Cotm1and HQ
Offutt AFB, NE
04/01/88
Date:
Location of Document:
Castle Air Force Base
-----------------------------------------------------------------
Document Number:
CAS-034-003
Title:' Remedial Investigation/Feasibility Study for Ca$tle AFB
Volume III: Quality Assuranc;:e Project Plan. .
Author:
IT Corporation
Martinez, CA
Strategic Air Connand HQ
Offutt AFB, NE
Date 10/01/88
Recipient:
Location of Document: - Castle Air Force Base
-----------------------------------------------------------------
(
Document Number:
CAS-034-004
Title:
Remedial Investigation/Feasibility Study for Castle Air
Force Base Volume II: Sampling and Analysis Plan
Author:
IT Corporation
Martinez, CA
Recipient:
Strategic Air Cotrmand HQ
Offutt AFB,. NE .
04/01/88
Date:
Location of Document:
Castle Air Force Base
-----------------------------------------------------------------
-------
06/19/92
Adrninistrati ve Index
Castle Air Force Base, Califonrl.a
-.==========~======================================================
Document Number:
CAS-034-00S
Title:
Remedial Investigation/Feasibility Study for Castle AFB .
Vol I: Work Plan
Author:
Martin Marietta Energy Systems
Oak Ridge, TN
Recipi~t:
Castle Air Force Base
Merced, CA
Date:
04/01/88
IDeation of Document:
Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number:
CAS-034-006
Title:
Quality Control Requirements for Field Methods
Author: Martin Marietta - HAZWRAP
Oak Ridge, TN
Recipierit:. 93. CSG/EM
Castle Air Force Base, CA
Date:
02/28/89
IDeation of Document:
Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number:
CAS-034-007
Title: Requirements for Quality Control of' AnalYtical Data
Author: Martin Marietta - HAZWRAP
. Oak Ridge, TN
Recipient: 93 CSG/EM
Castle AFB, CA
Date:
07/31/88
-------
06/19/92
Administrative Record Index
Castle Air Force Base, Califo:rnia
-----------------------------------------------------------------
-----------------------------------------------------------------
location of Document:
Castle AFB, CA
-----------------------------------------------------------------
DocUinent Number:
CAS-034-008
Title:
Installation Restoration Program Work Plan for CAFB
Author:
Martin Marietta Energy Systems
Oak Ridge, 'IN
Recipient: CSG/DEV
Castle AFB, CA
Date:
11/01/90
Location of Document: Castle AFB, CA
-----------------------------------------------------------------
Document Number:
CAS-034-009
Title: Long-Term GrO\JIldwater SaI1I)ling Plan for Castle AFB,
Atwater, CA
Author: Martin Marietta Energy Systems
Oak Ridge, 'IN
Recipient: 93 CSG/DEV
Castle AFB, CA
Date:
03/01/91
location of Document:
Castle AFB, CA
-----------------------------------------------------------------
Document Number:
CAS-034-010
. Title:
Remedial Investigation/Fea,sibility Study for Operable
Unit 2, Castle Air Force Base, CA
Author:
Metcalf & Eddy.
Santa Clara, CA
-------
06/19/92
Administrative Record Index
Castle Air Force Base, Califo:rni.a
=================================================================
Recipient:
93 SP'IG/DEV
Castle AFB, CA
Date:
09/06/91
. -
IDeation of Document:
Castle AFB, CA
-----------------------------------------------------------------
Document Number:
CAS-034-011
Title:
Draft Final Remedial Investigation/Feasibility Study
Baseline Risk Assessment for Operable Unit No.2
Castle AFB, CA Vol 1 of 2
Metcalf & Eddy
Santa Clara, CA 95054
Author:
Recipient:
93 SPI'G/DEV
Castle AFB, CA
Date:
12/02/91
IDeation of Document:
Castle AFB, CA 95342-5000
----------------------------------------------------------------- I
Document Number:
CAS-034-012
Draft Final Remedial Investigation/Feasibility Study
Baseline Risk Assessment for Operable Unit No.2
Castle AFB, CA
Author: Metcalf & Eddy
. Santa Clara, CA 95054
Title:
Recipient:
93 SP'IG/DEV
. Castle AFB,. CA
Date:
12/02/91
IDeation of Document : . Castle AFB, CA
-----------------------------------------------------------------
Document Number:
CAS-034-013
-------
06/19/92
Administrative Record Index
Castle Air Force Base, California
.=================================================================
Title: . Draft Final Remedial Investigation/Feasibility Study
Baseline Risk Assessment for Operable Unit 2, Vall of 2
Castle Air Force Base, Merced County CA
Author:
Metcalf & Eddy
Santa Clara, CA
Recipient: 93 SPIG/DEV
Castle AFB, CA
Date:
01/30/92
IDcation of Document: Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number:
CAS-034-014
I.
Title:
Draft Final Remedial Investigation/Feasibility Study
Baseline Risk Assessment for Operable Unit 1, Vol.
2 of 2, Castle Air Force Base, Merced County, CA
Metcalf & Eddy
Santa Clara, CA
Author:
Recipient:
93 SPIG/DEV
Castle Air Force Base, CA
Date:
01/30/92
IDcation of Document:
Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number:
CAS-034-015
Title:. Groundwater Remediation SYstem 9(erable Unit No.1
Draft 100% Design, Design SpecifJ.cations, Vol I
Castle AFB, CA Contract #N62474-88-D-5086
Author:
Co~rehensive IDng-Terrn
EnVJ.ronmental Action Navy
Recipient: Lt Col Thomas R.
93 CES/CFN
Date: OS/27/92
Baker
-------
06/19/92
Administrative Record Index
Castle Air Force Base California
=================================================================
IDeation of Document:
Castle AFB, CA
-----------------------------------------------------------------
Title:
Document Number:
CAS-034-016
Author:
Groundwater Remediation System Operable Unit No.1
Draft 100% Design, Design Specifications, Vol. II
Castle AFB, CA Contract #N62474-88-D-5086
Corrprehensi ve IDng-Term
Environmental Action Navy
Recipient: Lt Col Thomas R.
93 CES/DEV
Date: OS/27/92
Baker
IDeation of Document:
Castle AFB, CA
-----------------------------------------------------------------
Title:
Document Number:
CAS-034-017
.fwthor:
Castle AFB Operable Unit No.1 Groundwater
Remediation System Draft 100% Design Cost Estimating
Contract #N62474-88-D-5086
Corq,:>rehensi ve Long-Term
EnVl.ronmental Action-Navy
Recipient: Lt Col Thomas R.
93 CES/DEV
Date: OS/29/92
Baker
Location of DoCLm1eIlt:
Castle AFB, CA
-----------------------------------------------------------------
Title:
Document Number:
CAS-034-018
Author:
Castle AFB Operable Unit No.1, Groundwater Remediation
System, Draft 100% Design-Vicinity Map, Site IDeation
Map and Sheet Index
Corrprehensi ve IDng-Term
-------
06/19/92
. Administrative Record Index
Castle Air Force Base, Califonlia
=================================================================
Recipient: Lt Col Thomas R. Baker
93 CES/CEV
Date: OS/29/92
Location of Document:
CastleAFB, CA
-----------------------------------------------------------------
Document Number:
CAS-034-019
Title:
Draft Remedial Action Work Plan, Operable Unit No.1
Contract No. N62474~88-D-5086, Castle AFB
Comprehensive Long-Term
Environmental Action-Navy
Author:
Lt Col Thomas R. Baker
93 CES/DEV
Date: OS/29/92
Recipient:
wcation of Document:
Castle AFB, CA:
. .
-----------------------------------------------------------------
Document Number:
CAS~034-020
Title:
Draft Basis of Design Report, Operable unit No.1
Contract No. N62474-88-D~5086, Castle AFB, CA
C~rehensive Io~-Term
EnVl.romnental Act:lon Navy
Author:
Recipient: . Lt Col Thomas R. Baker
93 CES/DEV
Date: OS/29/92
. Location of Document: Castle AFB, CA
-------~---------------------------------------------------------
Document Number: CAS-035-001
Title: Prelim:inaJ::y Site Characterization Report for CAFB - Vols.
1, 2, and 3
-------
06/19/92
Adrninistrati ve Record Index
Castle Air Force Base, Califonrla
==========~======================================================
. Author: HAZWRAP - Martin Marietta
Energy Systems, oak Ridge, TN
Re~ipient:
HQ SAC
Offutt AFB, NE
01/09/90
Date:
IDeation of Document: Castle AFB, CA
-----------------------------------------------------------------
Document Number:
CAS-035-002
Titl~:
Author:
EPA Comments on OUFS-1 Proposed Plan
Michael Work, EPA Region IX
Remedial Project Manager
Recipient: Layi Oyelowo
93 CSG1DFN, CAFB
Date: 11/27/90
Locaton of Document:
Castle AFB, CA
---------------------~-------------------------------------------
Document Number:
CAS-035-003
Title:
Interim Operable Unit No.1 Feasibility Study of C'.AFB
Author: Martin Marietta En~rgy System
Oak Ridge, 'IN
. Recipient:
Castle AF'B, CA
Date:
01/12/90
. Location of Document: . CastleAFB, CA
-----------------------------------------------------------------
Document Number:
CAS-035-004
Title: . Proposed Plan for Castle Air Force Base
-------
06/19/92
Adm:ini.strati ve Record Index
Castle Air Force Base I California
=================================================================
Author:
Martin Marietta Energy System
Oak Ridgel TN .
Recipient:
Castle Air Force Base I CA
Date:
01/12/90
Location of Document:
Castle Air Force Basel CA
-----------------------------------------------------------------
Document Number:
CAS-03S-00S
Ti tIe: Dept. of Toxic Substances Control's Comments. on Draft
. Final Proposed Plan (PP) Operable Unit No.2 (00-2)
Castle Air Force Base I Califonu.a .
Author: Mr. John 0' Kane
Dept I Toxic Substances Control
Recipient: 93 SPI'G/DEV
Date: 03/23/92
Location of Document:
Castle AFB, CA
-----------------------------------------------------------------
Document Number:
CAS-03S-006
Fact Sheet on Proposed Plan for Operable Unit NO.2
Announcing Public Con1nent Period and Corrmunity
Meeting on 18 May 1992
Author: - Public Affairs Office
Castle AFB I CA
Title:
Recipient:
General Public
Date: 04/30/92
Location of Document: Castle AFB & Merced Librazy
-----------------------------------------------------------------
Document Number:
CAS-042-001
-------
06/19/92.
Administrative Record Index
Castle Air Force Base, California
=================================================================
Title: Health and Safety Code, Article 9.5
Author:
State of California
Recipient:
Date:
01/01/84
Location of Document:
Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number:
CAS-042-002
Press Release, New Standards for 11 Chemical Contaminants
of Drinking Water to Become Effective 25 Feb 89,
Author: Department of Health Services
Sacramento, CA
Title:
Recipient:
93 CSG/EM
Castle AFB, CA
02/25/89
Date:
Location of Document:
Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number: CAS-051-001
Title:
M' Response to Specific Corrments Interim Operable unit 1
Record. of Decision, Castle AFB, CA
IT CorPOration
Martinez,. CA
Author:
Recipient: Castle AFB, CA
Date: . 06/01/91
Location of Document:
Castle Air Force Base, CA
------------------------------------------------------------~----
-------
06/19/92
Administrative Record Index
Castle Air Force Base, California
.==========~======================================================
Title:
Document Number:
Author:
Recipient:
Date:
CAS-051-002
Appendix H, Environmental Inforrcation Form Record of
Decision Interim Operable Unit No.1, for Castle Air
Force Base
Thorcas R. Baker, Lt Col, USAF
93 CSG/DEV, Castle AFB, CA
08/07/91
IDeation of Document:
Castle AFB, CA
-----------------------------------------------------------------
Title:
Document Number: CAS-051-003
Author:
Recipient:
Date:
Appendix I, Environmental Checklist Fonn, Record of
Decision Interim Operable Unit No.1 for Castle Air Force
Base, CA
Anthony J. Landis, Chief, Site Mit. Brch,
Toxic SUbstance Ctrl P.
08/07/91
IDeation of Document:
Castle AFB, CA
-----------------------------------------------------------------
Title:
Document Number:
CAS-051-004
Author:
Final Technical Document To SUpport No Further Action
Site Nos. 22, 23, 24, 25, 26, and 27
Martin Marietta Energy System me.
Oak Ridge, TN .
Recipient: 'Ihomas R. Baker, Lt CoI, USAF
93 CSG/DEV, Castle AFB, CA
Date: 09/16/91
-------
06/19/92
Administrative Record Index
Castle Air Force Base, 9alifonria
~=========================================~=======================
IDcation of Document:
Castle Air Force Base, CalifonU,a
-----------------------------------------------------------------
DocUment Number:
,
CAS-052-001
Title: Record of Decision Interim Operable Unit No.1 for CAFB
Author:
Martin Marietta Energy System
Oak Ridge, 'IN , .
Recipient:
93 CSG/DEV
Castle AFB, CA
08/07/91
. Date:
IDcation.of Document:
Castle AFB, CA
. . .
-----------------------------------------------------------------
Document Number:
CAS-061-002
Title:
Status Report-Cleanup and Abatement Order No. 84-027
(Reference CRWQCB ltr dtd 21 April 1987)
Ronald' L. Hawkins, Lt Col, USAF
Environmental Task Force
Author:
Recipient:
James B. Wolfson (Fresno)
CA Regional Water Quality Control Board
OS/22/87
Date:
Location of Document:
Castle Air Force Base, CA
-----------------------------------------------------------------
Document. Number:
CAS-073-001
Title: Castle AFB Recommendations for Historic Preservation.
Author:
K Landreth & J Isaacson
US Army Const Eng Res Lab
Recipient:
93 CSG/DEV .
Castle AFB, CA
-------
06/19/92
Adrninistrati ve Record Index
Castle Air Force Base, Califonria
=================================================================
Date:
11/01/90
Location of Document:
Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number:
CAS-078-00l
Title:
Notification of Addition of Castle Air Force Base to the
NFL .
Jeff Zelikson
EPA, San Francisco, CA
Author:
Recipient: Dennis McGuirk, Col, USAF
93 PJ:IIW/C:V, Castle AFB, CA
Date:
07/22/87
Location of Document: Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number: CAS-08l-001
Title:
Author:
Health Assessments of USAF National Priority List.Sites
Author Chan J
Environmental Task Force
Recipient:
Doug Hawkins
Office of Health & Emergency Planning
04/26/89
Date:
Location of Document:
Castle Air. Force Base,. CA
-----------------------------------------------------------------
Document Number:
CAS-082-001
Title:
Preliminary Health Assessment for Castle AFB
Author: ATSDR-US Public Health Se:rv.
Recipient:
Castle Air Force Base, CA
-------
Date: 10/27/88
06/19/92
Administrative Record Index
Castle Air Force Base, Califonria
=================================================================
wcation of Document:
Castle Air Force Base
----------------------------------------~------------------------
Document Number:
CAS-112-001
Title: Ccmnunity Relations Plan for the Remedial Investigation
Feasibility Study at Castle Air Force Base'
Author:
IT Corporation
Martinez, CA
Recip~ent:
Strategic Air Command HQ
Offutt AFB, NE
Date:
10/01/88
wcation of Document:
Castle Air Force Base
-----------------------------------------------------------------
Document Number:
CAS-112-002
Title:
Author:
Base ~s Possible Past Refuse Sites
Valley Bomber
Recipient:
93 CSG/EM
Castle AFB, CA
Date:
08/10/90
iocation of.Document:
Castle AFB, CA
----~-~----------------------------------------------------------
Document Nuniber:
CAS-113-001
Author:
Castle AFB Announces Extension of Public Conment Period
on Proposed Cleanup .
93 BMW/PA
Castle AFB, CA
. Title:
Recipient:
Merced Sun Star/Atwater Signal, Merced, CA .
-------
Date: 01/23/91
06/19/92
Administrative Record' Index
Castle Air Force Base, Califo:rnia
-----------------------------------------------------------------
-----------------------------------------------------------------
IDeation of Document:
Castle AFB, CA
-----------------------------------------------------------------
Document Number:
CAS-114-001
Title:
Minutes of the Technical Review Committee (Quarterly)
Author: Linda L. Leong, Major, USAF
93 BMW/PA
Recipient:
. '
93 CSG/EM
Castle Air Force Base, CA
Date:
/ /
IDeation of Document:
Castle AFB, CA
-----------------------------------------------------------------
Document Number:
CAS-114-003
Title:
Solid Waste Assesment Test Work Plan for Castle Vista
Landfill
Martin Marietta Energy System
Oak Ridge, TN
Author:
Recipient: Castle AFB, CA
Date:
05/01/90
IDeation of Document :
Castle Air Force Base, CA
--------------------------------------------------------~--------
Document Number:
CAS-114-004
Title:
Author:
Proposed Agenda for Public Meeting
93 BMW/PA
Castle AFB, CA
Recipient:
93 CSG/DEV
Castle AFB, CA
-------
Date:
/
/
06/1.9/92
Administrative Record Index
Castle Air Force Base, Califo:rnia
.=================================================================
location of Document: . Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number:
CAS-114-00S
Title:
Public Presentation on Operable Unit 1. Ground Cleanup
93 BMW/PA
Castle AFB, CA
Author:
Recipient:
93 CSG/DEV
Castle AFB, CA
01./08/91.
Date:
location of Document:
Castle AFB, CA
-----------------------------------------------------------------
Document Number:
CAS-117-001
Title:
Author:
Quarterly TCE SUrrmary Report (Letters to Residents)
Brian L. Sassaman, 2Lt, USAF
93 STRAT HOSP/SGPB
Recipient:
Various
Date:
07/31/90
location of Document: Castle AFB, CA
-----------------------------------------------------~-----------
Document Number:
CAS-119-001
Title:
Castle AFB' s Environmental Update
Author: Public Affairs Office
93 BMW/PA, CAFE
Recipient: 93 CSG/DEV
Castle AFB, CA
-------
Date: 10/01/90
06/19/92
Administrative Record Index
Castle Air Force Base, California
=================================================================
iDeation of Document:
Castle Air Force Base, CA
-----------------------------------------------------------------
. .
Document Number:
CAS-119-002
Title:
Castle AFB' sEnvironmental Update
Public Affairs Office
93 BW/PA, CAFB
Author:
Recipient: 93 SPI'G/DEV
. .
Date: 03/15/92
IDeation of Document:
Castle AFB, CA
-----------------------------------------------------------------
Document Number: CAS-121-001
Title:
Interim Guidelines and Specifications for Preparing
Quality Assurance Project Plans (QAPJP)
EPA
Author:
Recipient:
Date:
12/29/80
iDeation of Document:
Castle AFB, CA
-------------------------------------------------'----------------
Document Number:
CAS-121-002
Title: Policy for Superfund Coni>liance with the RCRA and Disposal
. Restrictions
Author:
united States Environmental
Protection Agency, Washington, D. C.
Recipient: / Regional-Administrators,
Regions I-X
-------
Date: 04/17/89
06/19/92
Administrative Record Index
Castle Air Force Base, California
=================================================================
Location of Document:
Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number: CAS-121-003
Title:
Author:
A Guide On Remedial Actions for Contaminated Ground Water
united States Environmental
Protection Agency (EPA)
Recipient:
93 CSG/EM
Castle AFB, CA
Date:
04/01/89
Location of Document:
Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number:
CAS-121-004
Title:
Interim Final Guidance on Preparing Superfund Decision
Documents: Proposed Plan; Record of Decision, .
Explanation of Significant Differences; Record of
Decision Amendment
Author:
Office of Emergency & Remedial
ReSPOnSe (EPA) , Washington, DC
Recipient:
93 CSG/EM
Castle AFB, CA
06/01/89
Date:
Location of Document:
Castle AFB, CA
-----------------------------------------------------------------
Document Number:
CAS-121-00S
Title:
Author:
RCRA Facility Assessment Guidance
united States Environmental
Protection Agency
-------
Recipient:
06/19/92
93 CSG/EM
Administrative Record Index
Castle Air Force Base, California
=====================================--===========================
Date:
10/01/86
lDcq,t;ion:
Castle Air Force Base, CA
..
----------------------------------------------------~------------
Document Number:
CAS-1.21-006
Title:
Author:
Superfund Exposure Assessment Manual
United States Environmental
Protection Agency
Recipient:
93 CSG/EM
Castle Air Force Base, CA
Date: 04/01/88
lDcation of Document:
Castle Air Force Base CA
-----------------------------------------------------------------
Document Number:
CAS-121-007
Title:
Risk Assessment Guidance for SUperfund-Environmental
Evaluation Manual Interim Final
United States Environmental
Protection Agency
Author:
Recipient:
93 CSG/EM
Castle AFB, CA
Date:
03/01/89
lDcati6n of Document:
Castle Air Force .Base, CA
-----------------------------------------------------------------
Document Number:
CAS-1.21-008
Title:
Administrative Records for Installation Restoration
Program
HQ SAC/DFNC
Offutt AFa, NE
Author:
-------
06/19/92
Administrative Record Index
Castle Air Force Ba,se, California
-----------------------------------------------------------------
-----------------------------------------------------------------
Recipient:
93 CSG/EM .
Castle AFB, CA
06/08/89
. Dat~:.
lDcation of Document:
Castle Air Force Base, ~
-----------------------------------------------------------------
Document Number:
CAS-121-009
Title:
Comprehensive Environmental, Response, Caq;>ensation,
and Liability Act of 1980 (CE:RCIA)
Published by The Bureau of National Affairs
Washington, DC .
Autho+ :
Recipient:
Castle Air Force Base
Date:
02/24/89
Location of Document':
Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number:
CAS-121-009
Title:
Author:
National Contingency Plan
Environmental Protection Agency
Recipient: 93 CSG/EM
Castle AFB, CA
, .
Date:
03/08/90
Location of Document:
Castle AFB ,CA
--------,------'----------------,-------------------------~---------
Document Number:
CAS-122-001
Title: What to Include in a 'U. S. EPA Region 9 Sample Plan if you
are not. going to use the Cont:r:act Lab Program
Author:
EPA Region 9
-------
06/19/92.
Administrative Record Index
Castle Air Force Base, California
------~---~------------------------------------------------------
Recipient :'
Date:
01/01/86
Location of Document:
Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number:
CAS-123-001
Title: . Landfills at Castle Air Force Base, Merced CO\IDty
Author:
Michael H. Mosbacher, P. E .
CA Regional Water Control Board, Sacramento
Recipient:
Arthur Chan, Envr. Task Force
HQ 93rd BMW-Castle AFB
10/05/88
Date:
Location of Document:
Castle Air Force Base, CA
-----------------------------------------------------------------
Docmnent Number: CAS-123-002
Title: Solid Waste Assessment Test Guidance
Author:
State Water Resources Control Board
Recipient:
Date:
.03/01/86
Location of Document: Castle Air Force Base, CA
---------------------------~-------------------------------------
Document Number:
CAS-123-003
Author:
Staff Report on Testing Guidelines for Active Solid Waste
Disposal Sites
Toxic Pollutants Branch
Stationary Source Division
Title:
Recipient:
-------
06/19/92
Administrative Record Index
Castle Air Force Base, California
.==========~======================================================
Date:
12/01/86
Location of Document:
Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number:
CAS-124-001
Title: Human EJ(posures to Volatile Halogenated Organic Chemicals
in Indoor and OUtdoor Air .
Author:
Julian B. Andelman
Recipient:
Date:
01/01/85
Location of Document:
Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number:
CAS-124-002
Title:
Human Exposure to Volatile Organic ~ in Household
Tap Water: The Indoor Inhalation Pathway
Thotras E. McKone
Author:
Recipient:
Date:
01/01/87
Location of Document:
Castle Air Force Base, CA
-----------~-----------------------------------------------------
DocUment Number:
CAS-124-003
Title:
The Role of Skin Absorption as a Route of Exposure for
Volatile Organic Cotrpounds (VOCs) in Drinking Water
Brown, Bishop and Rowan
Author:
Recipient:
Date:
05/01/84
-------
06/19/82
Administrative Record Index
Castle Air Force Base, California
=================================================================
iDeation of Document:
Castle Air Force Base, CA
-------------------------------~---------------------------------
.' Document Number:
CAS-124-004
Title:
Alternatives for Reuoval of TeE from Groundwater at
Castle Air Force Base, Merced, California
Author: Oak Ridge National Iaborato~
Jom I.oyd
Recipient: Ahmet Turkoglu
Castle AFB, CA
. .
Date:
01/28/87
iDeation of Document: Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number:
CAS-124-005
Title:
A Contaminant TransPort Model of Trichloroethylene
Movement in Groundwater at Castle Air Force Base, CA
Lizanne Avon-
Author:
Recipient:
93 CSG/EM
Castle Air Force Base, CA
Date:
05/01/88
IDeation of Document:
Castle Air Force Base, CA
-----------------------------------------------------------------
. .
06/18/93
AMENDED JU')M]]aSTRATIVE RECORD INDEX
CASTLE AIR FORCE BASE, CALIFORNiA
=================================================================
. .
Document Number:
CAS-125-001
Title:
Final Basis of Design Report Operable Unit No.1
Vol. I
-------
06/18/93
AMENDED ADmNISTRATJ:VE RECORD INDEX
CASTLE AIR FORCE BASE, CALIFORNIA
.==========~======================================================
Author:
PRC .Environmental Management Inc.. for Navy CLEAN
Recipient:
Date:
12/10/92
wcation of Document:
Castle Air Force Base, CA
. .
-----------------------------------------------------------------
Document Number:
CAS-125-002
Title:
Final Basis of Design Report Operable Unit No.1
Vol. II
Author:
PRC Environmental Management Inc. for Navy CLEAN
Recipient:
Date:
09/29/92
wcation of Document:
Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number:
CAS-125-003
Title:
Operable Unit No. 1~ Groundwater Remediation System
Final 100% Design Cost Estimate (and map)
PRC Environmental Management Inc. for Navy CLEAN
Author:
Recipient:
Date: 09/29/92
wcation of Document: Castle Air Force Base, CA
. . .
-----------------------------------------.------------------------
. Document Number:
CAS-1.25-004
Title:
Groundwater Remediation System Operable Unit No.1
Design Specifications Vols. I and II
. .
Author:
PRC Environmental Management Inc. for Navy CLEAN
-------
06/18/93
AMENDED ADMINISTRATIVE RECORD INDEX
CASTLE AIR FORCE BASE, CALIFORNIA
==========~======================================================
Recipient:
Date:
09/29/92
IDeation of Document: Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number:
CAS-125-005
Title:
Final Remedial Action Work Plan Operable Unit No.1
06/18/93
. .
. .
-------------------------------------------------------~---------
Author:
PRC .Enviromnental Management. Inc. for Navy CLEAN
Recipient:
Date:
12/10/92
IDeation of Document:
Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number:
CAS~126-001
Title:
Author:
Draft Final Record of Decision for Operable Unit No.2
U.S. EPA Region 9
Recipient:
Date:
10/92
IDeation of Document:
Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number: CAS-127-001
Title:
Author:
Castle AFB I S Environmental Update
Scarlette Parker, TSgt, USAF
93 BW/PA
Castle AFB, CA
-------
06/18/93
AMENDED ADMINISTRATIVE RECDRD INDEX
CASTLE AIR FORCE BASE, CALIFORNXA .
-----------------------------------------------------------------
-----------------------------------------------------------------
Recipient:
Date:
03/19/93
,.
Location of Document:
Castle Air Force Base, CA
-----------------------------------------------------------------
Document Number: CAS-128-00r
Title:
Technical Memorandum Air Stripper Pilot Study Operable
Unit No.1.
PRC Environmental Management Inc. for Navy CLEAN
Author:
Recipient:
Date:
05/18/93
Location of DoCument:
Castle Air Force Base, CA
-----------------------------------------------------------------
Document ~r:
CAS-128-002
Title:
Technical Memorandum Aquifer Plmping Test, Operable Unit
No.1.
PRC Environmental Management Inc. for Navy CLEAN
Author:
Recipient:
Date: 05/18/93
Location of Document:
Castle Air Force Bas.e, CA
-----------------------------------------------------------------
DoetmleIlt Number:
CAS-129-001
Title:
OU-2 ROD Responsiveness SurmaJ:y (public comnents and
responses)
Environmental Flight and Public Affairs Castle .AFB
Author:
-------
AMENDED ADMINISTRATIVE RECORD INDEX
CASTLE AIR FORCE BASE, CALIFORNIA
==========~======================================================
Date:
Oct 92
wcation of Document:
Castle AFB I CA
-----------------------------------------------------------------
Document Number:
CAS-129-002
Title:
Remedial Investigation/Feasibility Study Baseline Risk
Assessment for OU-2 Volumes 1 & 2
Author:
Metcalf & Eddy
Recipient:
Castle AFB I CA
Date:
Dec 91
wcation of Document:
Castle AFB I CA
-----------------------------------------------------------------
Document Number:
CAS-129-003
Title:
Author:
Proposed Plan for OU-2
Environmenta~ Flight Castle AFB
Recipient:
Date:
Apr 92
wcation of Document:
Castle AFB I CA
-------
APPENDIX B
RESPONSIVENESS SUMMARY
. ~
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OPERABLE UNIT 2 ROD
RFSPONSIVENFSS SUMMARY
OVERVIEW
At the time of the public ~mment period, Castle AFB bad DaITOWed the selection to a
prefeITed alternative:
Castle AFB, U.S. EPA and Cal-EPJ\, DfSC, agree that the preferred alternative consists of
grmmdwater removal by pumping and surface tremment of the groundwater using air
stripping. The emissions from the air stripper will be controlled using activated carbon
adsorption. The treated groundwater will be reinjected into the same aquifer from which it is
removed.
.~
Judging ftom the comments received dming the public comment period, local residents are
most concerned about the extent aiId location of: the p11.IlDe, depletion of the groundwater
supply caused by the remediation, amomrt of time required to complete cleanup actions and
possible production of additional hazardous waste while cleaning up the current contmnimmts.
However, no commentor expressed disagreement with the selected alternative.
BACKGROUND ON COMMUNITY INVOLVEMENT
In October 1983, Castle AFB completed Phase I of the Installation Restoration Program
which identified sites of potential environmental concern. In February 1984, base officials
notified workers and residents at Castle that TCE levels in some groundwater were above the
1
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5 parts per billion maximum COJ:Jtmnin::mt level. Off-base, comrrnmity concern has generally
been limited to those residents directly affected by the TCE contamination including residents
of Castle Mobile Home Park, Santa Fe Drive and Wa1lace Road. However, with the
announcement of Castle's closure, these concerns are now shifting. Off-base CJVT1I11Imity
residents-seem. to be more concerned with the length of time required to clean up the base's
contamination, adequate funeting to completely clean up the base and how this will affect their
reuse of the land after the Air Force leaves in September 1995.
. Sixteen cnmrmmity concerns and COIDI]]CIlts were raised about the cleanup actions during the
public meeting held May 18, 1992, in the Atwater Oty Hall. Castle also received Written
CQT11TTIP.I1ts ftom an attOrney, the Regional Water Quality Control Board and Califomia
. .
Department of Toxic Substances Controi: These concerns and COIIJ[]]e[lts, and Castle's
responses are shown below.
Comrmmity Co~t No.1
. "Is the time line for the schedule of future activities in the. OU-2 PrOposed Plan a realistic
~ ~
time ftame?,.
~
The dates given in the schedule of:future activities are estimates. Our consulting engineers
. .
based the time line on several factors: (1) the volume of water to be treated, (2) th~ rate at
which it will be treated, (3) levels of CQIWm1ination, and (4) types of chemicals.
2
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- ,
Community Conment No.2
"If you're drawing water out of the plume for irrigation purposes, are there any ill effects on
the ftuit that's grown in that area?"
~
There have been no ill effects on the ftuit so far. In response to a question about the safety
of almond orchards on Wallace Road last year, air samples were taken to measure the TCE
concentrations in the air dming irrigation. Sampling results revealed no detectable traces of
TCE in these air samples. We then had some almonds from these orchards ~yzed for TCE
absorption into the fiuit, and these results were also negative.
Comrrnmity Cooment No.3
'.
\
''Is this the only TCE plume we're ~HT\g with?"
Resjxmse
:$
...
No, Operable Unit No. I deals with the main base TCE plume. This strictly deals with a
different area of the base. OU-2 involves the TCE plume in the Wallace Road and Discharge
Area 4 areas of the base.
3
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Community Comment No.4
"What's the by-product off the stripping tower?"
Response
There are two by-products ftam the stripping tower: (1) treated grOmldwater and (2) air
conrnmin~ted with volatile organic compotmds (TeE). The conrnminm-ed air stream passes
through a granular activated carbon (GAC) filter, and will be monitored to ensure applicable
air qualitY standards are met. Treated grotmd water is reinjected into the aquifer.
. . .
. .
Periodically, carbon is steam regenerated. This process produces a mixture of water and TCE
which flaM into a decanter. TCE is removed from the bottom to a holding tank fei recycling
or disposal. After passing through the decanter, the water is returned to the air stripper to be
retreated
Community Comment No.5
. ~ .
"Is the data you've gathered so far-'Sufficient to effectively design and remediate the
grotmdwater contaminmion?"
Response
No, the base began sampling and analyzing a network of both private and monitoring wells
when TCE was first discovered. As the conrnmination spread, we increased the scope and
complexity of our sampling program. Although the extent of conrnmination is generally
mown, we believe the data necessmy to clearly establish the TCE plmne boundaries is
4
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lacking. However, Castle has committed to install monitoring wells both on- and off..site
during the remedial design phase of OU-2. A scope of WOIk for the installation of these
wells has been developed and approved by EP A and Cal-EP A Additional monitoring wells
have enabled us to more clearly establish the plume bcnmdaries. In addition, the existing
. extraction system. has been ~ for effectiveness. It appears that the removal action has
been successful at removing the most highly cmtmninM-Pil portion of the OU-2 plume.
Comrmmity Comment No.6
"The identification of the plume you show on the slide is two dimem:ional. How deep is it
and is TCE heavier than water?"
~
'.
In this area, we have identified three levels of groundwater that are cnntmninMP(J with TeE.
They are the upper and lower shallow aquifer which extends between 50 and 100 feet below
the surface and the subsba1low aqtlfer which begins about 130 feet and extends to
approximately 250 feet below surface. Yes, pure TCE is heavier than water.
Connmmity Comment No.7
''Will your preferred alternative be completed in a timely manner and will it return the
grotmdwater to California safe drinking water standards? You've said very little 3bout soil
contmnin:mOD. How do you propose to cleanup the contmnin~ed soil above this aquifer?"
5
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Response
Qeaning up contaminMed groundwater may take many years. We believe it will probably
take until the year 2017 to complete the CERCLA process. . However, Castle is committed to
cleaning up COJ]1m'ninm;on created by our flying mission over the last 50 plus years. We are
looking at.severa1 different methods and/or technologies to clean up contmnin$lted soils. Soil
cleanup will be investigated pursuant to the Source Control Operable Unit (SooU) which is
currently tmderway.
Commmity Comment No.8
"I do not believe that your plan for cleanup is accurate as it is my understanding that three
test wells have been placed on my clients' property. From your records these wells are 701,
. ,
. '.
702 and 702A Well, 702A contains TCE and benzene as both have been identified in the
grOtmdwater supply with TCE at a level in excess of the safe drinking water standard
Because of the test wells identifying TCE located in the groundwater beneath my clients'
"<:
property, I am of the opinion that -the 'plume identified on your map is inaccurate and should
be amended to reflect its actual extenSion beyond the base as identified in your Interim
Design Report aU-! for Castle AFB, dated Feb. 7, 1992, as well as earlier envirnnrnen~]
surveys. We would appreciate a response to the following questions: (1) response regarding
modifying the plans; (2) proposed scope of cleanup and extension of the existing plmne; (3)
estimated time of completion of the remedial action and work plan; and (4) the compensation
to be provided to my clients for damages. now identified from these test wells, to their real
estate. n
6
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~
The Interim Design .Report for OU-I covers the main base sector (MBS) COJ'Itmninant plmne,
and as such it is not intended to address gt'01mdwater m the vicinity of your client's property.
0U-2.covers the area you are concerned with. In response to your questions: (I) Castle does
not plan to modifY its plans for OU-I (the MBS plmne). (2) The proposed scope bas not
changed and Castle continues to be committed to clean up cnn1mninMM gr01Dld water it bas
caused to drinking water standards. (3) Castle's consultants believe it will take approximately
20 years to complete the cleanup at 0U-2, the WOIk plan for the design of 00-2 shoUld be
complete sometime m 1993. (4) Castle is not aware of any real property damages to and/or
on your clients real property.
.,
Comrmmity Comment No.9
Cal-EP A, DTSC, concurs with the use of the air stripping technology for tr~ of gr01D1d
water cnnrniniT\g volatile organic COmpounds. However, in order to effectively design and
~iate ground water CQDtmnination, all necessary data must be collected DfSC bas .
expressed existing deficiencies of data for 6U-2 in previous correspondences to Castle. It
remams DTSCs position that this data nmst be obtained before finali7.ing the OU-2 design.
Response
Castle agrees with this position. Reference Response No, S.
7
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Comnnmity Comnent No. 10
It is ursCs understanding that Castle will implement as part of the design, activities to
define both the vertical and lateral extent of ground water contmninMion within the
bo1IDdaries of OU-2 and detennine aquifer characteristics, including gradients, transmissivity,
water quality parameters and background water quality conditions.
Resjxmse
Castle recognized the need to do further characterization studies of the gro1md water. .
. conrnmination to better define the plmne. Subsequently, a workplan was developed, reviewed
and approved by the parties to the Castle AFB Federal Facility Agreement Reference
Response No.5.
Connmmity Connnent No. 11
From a meeting between the EPA, Region IX, and DTS4 it was agreed that revisions to the
~
text of0U-2 Proposed Plan Fact~heet would be made pursuant to 40 CFR300.515(e) to
address the State of Californiis concerns. . However, the OU-2 Proposed Plan Fact Sheet was
released prior to the incorporation of the negotiated revisions. DTSC is therefore submitting
the items for inclusion into the Administrative Record and for incorporation into the OU-2 . .
Record of Decision. The State of California specifically requested that the ROD shall address
and include the following: (1) A statement that the onsite and offsite plumes are not
- completely defined and that monitoring wells will be drilled both onsite and offsite ~ the
. .
design phase to clearly establish the plmne boundaries. Additionally, offsite extraction wells
8
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and related piping may be needed within the plume. A general schematic of the extraction
well, tr~ and injection well system will either be added to the proposed plan or used as
a graphic at the public U1eef1nf: (2) A detailed technical scope of work will be developed
for the additional plmne c.baJ:acterimion for the OU-2 plmne in all aquifers. The scope of
work will be the basis for the time schedule. Pha5ed impJementMion of the design will be
considered (3) An overall project schedule will be developed to balance investigation and
remediation priorities between reuse and 'Worst first" work. StremnHninf the technical and
administrative processes will be a JDYor goal of this effort. (4) 'Where sufficient technical
information is available, specific State ARARs will be included in the OU-2 ROD. If specific
design phase investigation infcnmation is identified as aitical for ARARs development, then
those ARARs will be provided after that information becomes available. This infon:nation
and subsequent ARARs should be prOvided prior to 10 percent. design completion.
~
Because of the lack of fimding at-Castle, EP A produced and mailed the final proposed plan
fact sheet for Castle. The:fact sheet was released to the. public on April 27, 1992. The
specific language requested by DTSC and California Regional Water Quality Control Board,
Central Valley Region (RWQCB) is addressed in this ROD. ARARs are also established in
the ROD.
9
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Conmmni~ Comment No, 12
The RWQCB believes the,preferred remedy has been select~ with data that is insufficient
, and -which lacks water quality information needed for the ROD to set numerical ARARs for
many constituents. Without adequate pbnne definition, water quality characterization of the
plmne and'the potential renyection areas, and aquifer charact:cristics it is technically
inappropriate to select a gro1Dld water~t scheme that is very dependent on these
parameters. Also, withqut the necessary water quality data it is impossible to protect the
gro\Dld water resource in the reinjection areas. We are not opposed to the use of air stripping'
technology for trPJUmP.nt of gro1Dld water. However, all necessmy data needs to be collected
. .
before the design of the remedy.
Res,ponse
InfOIIDation on plmne definition, potential reinjection areas and aquifer characteristics will be
collected during the 'design phase in order to avoid delays in implementation of the remedial
,~
actions. Castle agrees with this Cl'1mment Reference Responses No.5, 10 and 11.
Conmmni~ Comment No, 13
The TCE pl~ has not been completely defined. Many questions have been,raised by EP A,
DTSC and RWQCB on the vertical and horizontal extent of this plmne. This work should be
done prior to any design on the tr~tmP.nt system. This will allow the initial system'design to
incorporate the whole plume. This work needs to be accomplished prior to 10 percent design
completion. '
10
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~
Castle has comnitted to further characterization in order to finali7,e the design of the remedy
for OU-2. In order to implement the remedial actions as soon as is technically possible, data
will continue to be collected during the design phase. Reference Response No. S.
Comrrnmity CoJ1Ju1eIlt No. 14
Insufficient water quality data bas been done to set chemical specific ARARs for reinjection.
In order to determine how Castle AFB will meet the State Board Resolution 68-16 (the Anti-
degradation Policy) ARAR when it reinjects effluent, additional water quality cb.aracterization
is necessary. This information will be used to prevent other potential conrnminants (metals,
DBCP, nitrates, etc.) ftom being reinjected into other areas with higher quality water,
reducing or eliminating its benefiCial tJse. This data needs to be collected prior to the 10
percent design completion thereby enabling the system. to be designed effectively to clean up
the solvent plume as well as Protect the water quality at the reinjection areas.
....
Respmse
Compliance with ARARs is documented in this ROD. Castle agrees that additional remedial
investigative activities need to occur prior to fin~li7Mion of the design. ,The State of
California will have the opportuni1y to review ~ OU-2 design and remedial action workplan
to ensure that their concerns are addressed.' Referen~ Responses No.5, 10, and 11.
11
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Commmrity Comment No. 15
AqUifer characteristics (gradient, conductivity, etc.) have not been determined for nmch of the
00-2 area, especially in the off base sector of the plume~ This needs to be completed before
any 1remment design is done, so that dre system. can be designed effectively. This should be
cqmpleted "prior to 10 percent design completion. This will allow the trPJrtrnP.nt system to be
designed effectively to clean up the solvent plume as well as protect the water quality at the
reinjection areas.
Re$ponse
. .
Reference Re$ponse No.5, 10, 11, 13 and 14.
Conmnmity Cormnent No. 16
RWQCB request the follOVYing language be included in the ROD to clarify how Castle AFB
will proceed in collecting the data and developing the design for the OU-2 remedial action:
"<:"
(1) A detailed technical scope of WOrk for the OU-2 area will be developed to include
complete plmne definition, characterize water quality of the plmne and of the receiving
aquifer, and determine aquifer characteristics. The scope of work will be the basis for the
time schedule. Phased implementation of the design ~ be considered (2) An overall
project schedule will be developed to balance investigation and remediation priorities between
reuse and "worst first" work. S1remnlining the process will be explored by technical" staff.
and (3) Specific ARARs will be included in the OU-2 ROD. In order todetennine how
Castle will meet the State Board Resolution 68-16 (the Anti-degradation Policy) ARAR When
12
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it reinjects eftluent, additional water quality characterization is necessary. This information
will be provided prior to 10 percent design completion.
~
Section :vm, Subsection H, and Section 9 address RWQCB's points 1 and 2 above. ~e
has committed to undertake the work necessary to complete the design of the remedial
system. Reference Responses No.5 and 14.
.~
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