RODR069409
                                 PB94-964213
                                 EPA/ROD/R06-94/090
                                 February 1995
EPA  Superfund
       Record of Decision:
       D.L. Mud, Inc. (O.U.I),
       Abbeville, LA
       9/22/1994

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      RECORD OF DECISION
D.L. MUD, INC. SUPERFUND SITE
 VERMILION PARISH, LOUISIANA
        SEPTEMBER 1994

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                  D.L. MUD, INC. SUPERFUND SITE
                        RECORD OF DECISION

  STATUTORY PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT HAS
            BEEN MET AND FIVE-YEAR REVIEW IS REQUIRED

SITE NAME AND LOCATION

D.L. Mud, Inc. Superfund Site
Vermilion Parish, Louisiana

STATEMENT OF BASIS AND PURPOSE

     This decision document presents the selected remedial action
for the D.L. Mud, Inc. Superfund Site  (hereinafter D.L. Mud Site
or the site), in Vermilion Parish, Louisiana, which was chosen in
accordance with the Comprehensive Environmental Response, Compen-
sation, and Liability Act of 1980 (CERCLA), as amended by the
Superfund Amendments and Reauthorization Act of 1986 (SARA), 42
U.S.C. §9601 et seer. , and to the extent practicable, the National
Contingency Plan (NCP).  This decision is based on the Adminis-
trative Record for this site.

     The State of Louisiana concurs on the selected remedy.

ASSESSMENT OF THE SITE

     Actual or threatened releases of hazardous substances from
this site, if not addressed by implementing the response action
selected in this Record of Decision (ROD), may present an
imminent and substantial endangerment to public health, welfare,
or the environment.

DESCRIPTION OF THE REMEDY

     The site is being addressed as one operable unit.   The
principal concerns to be addressed at the site are from surface
soils contaminated with residual barium and contaminated
subsurface sludges associated with former impoundments.  The
major components of the selected remedy include:

     - Imposition of institutional controls to address the low
     level threats posed by the residual barium contamination in
     the surface soils.  Controls to be implemented include
     fencing and. deed notices/restrictions to ensure that future
     residential use of the property does not occur.

     - Excavation and offsite disposal of contaminated sludges
     and subsurface soils.

     - Limited ground water monitoring to ensure that residual
     barium contaminants left onsite do not migrate into usable
     drinking water sources.

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STATUTORY DETERMINATIONS

     The-selected remedy is protective of human health and the
environment, complies with Federal and State requirements that
are lega.lly applicable or relevant and appropriate to the
remedial action, and is cost effective.  This remedy utilizes
permanent solutions to the maximum extent practicable for this
site.

     To address the principal threats to human health and the
environment that were present at this site, a State-lead cleanup
action was conducted at this site in 1987.  This cleanup action
included the removal and offsite incineration of wastes from
onsite storage tanks and surface soils.  Although treatment of
the surface soils contaminated with residual barium is not being
conducted as part of this ROD due to the limited threats posed by
these residual materials, the overall remedial action (including
the 1987 State-lead cleanup) for this site does meet the
statutory preference for treatment as a principal element of the
remedy.

     Because the remedy will result in hazardous substances
remaining onsite above health-based concentration levels, a
review will be conducted within five years of commencement of the
remedial action to enfure that the remedy continues to provide
ad«
     late projection of human health and the environment.
        Saginaw                         Date
Regional Administrator
U.S. Environmental Protection Agency
Region 6

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                    D.L.  MUD,  INC.  SUPERFUKD SITE

                       9/94  RECORD  OF DECISION

                          CONCURRENCE PAGE-.
 Jamie VanBusTcirk, RPM
 D.L. Mud Superfund  Site
 Bill Ldthans, Chief
 AR/LA Superfund Enforcement
 George Malone, ORC
 Assistant Regional Counsel
          i, Chairman
ROD Peer Review Committee
Sam Becker, Chief
Superfund Enforcement Branch
Mark Peycke, Acting Chief
Superfund Branch, ORC
^.Walter Sutton
 Regional Counsel
Xllyn Davis, Director
Haz. Waste Management Division

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                        TABLE OF CONTENTS
                        RECORD OF DECISION
                  D.L. MUD, INC. SUPERFOND SITE
                   VERMILION PARISH, LOUISIANA


LIST OF ACRONYMS	   i

LIST OF FIGURES	ii

LIST OF APPENDICES	iii

I.   SITE NAME, LOCATION AND DESCRIPTION	   1

II.  SITE HISTORY AND ENFORCEMENT ACTIVITIES  	   4

III. HIGHLIGHTS OF COMMUNITY PARTICIPATION  	   7

IV.  SCOPE AND ROLE OF RESPONSE ACTION	   8

V.   SUMMARY OF SITE CHARACTERISTICS	   9

VI.  SUMMARY OF SITE RISKS	40

VII. DESCRIPTION OF ALTERNATIVES  	  56

VIII. SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES .  .  66

IX.  THE SELECTED REMEDY	72

X. STATUTORY DETERMINATIONS 	  76

XI.  DOCUMENTATION OF SIGNIFICANT CHANGES 	  81

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                         LIST OF ACRONYMS

 ACLs      - ALTERNATE CONCENTRATION LIMITS
 AOC '      - ADMINISTRATIVE ORDER ON CONSENT
 ARARS      - APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
 AWR       - ACRE WEIGHTED RISK
 BRA       - BASELINE RISK ASSESSME T
 CERCLA    - COMPREHENSIVE ENVIRONMENTAL RESPONSE,  COMPENSATION
             AND LIABILITY ACT
 COCS      - CHEMICALS OF CONCERN
 CTE       - CENTRAL TENDENCY EXPOSURE
 DOW       - DOW CHEMICAL COMPANY
 DSI       - DOWELL SCHLUMBERGER,  INC.
 EPA       - THE ENVIRONMENTAL  PROTECTION AGENCY
 ESI       - EXPANDED SITE ASSESSMENT
 FIT       - FIELD INVESTIGATION  TEAM
 FS         - FEASIBILITY STUDY
 GCVS      - GULF COAST VACUUM  SERVICES
 HI         - HAZARD INDEX
 HO.         - HAZARD QUOTIENT
 HRS       - HAZARDOUS RANKING  SCORE
 IOCS      - INORGANIC AND  ORGANIC  CHEMICAL CONSTITUENTS
 LDEQ      - THE LOUISIANA  DEPARTMENT OF ENVIRONMENTAL QUALITY
 LDNR      - THE LOUISIANA  DEPARTMENT OF NATURAL RESOURCES
 MCLS      - MAXIMUM CONTAMINANT  LEVELS
 MCLGs      - MAXIMUM CONTAMINANT  LEVEL GOALS
 MSL       - MEAN SEA LEVEL
 NCP       - NATION CONTINGENCY PIAN
 NOW       - NON-HAZARDOUS  OILFxZLD WASTE
 NPL       - NATIONAL PRIORITIES LIST
 O&M       - OPERATION AND  MAINTENANCE
 OVA       - ORGANIC VAPOR  ANALYZER
 OVM       - ORGANIC VAPOR  MONITOR
 PRPs       -  POTENTIALLY RESPONSIBLE PARTIES
 RAOS       -  REMEDIAL ACTION OBJECTIVES
 RCRA       -  RESOURCE CONSERVATION  AND  RECOVERY  ACT
 RfD        -  REFERENCE DOSE
 RI         -  REMEDIAL INVESTIGATION
 RME        -  REASONABLE MAXIMUM EXPC3URE
 ROD        - RECORD  OF DECISION
 SARA       -  SUPERFUND  AMENDMENTS AND REAUTHORIZATION  ACT
 SFS        -  SLOPE FACTORS
 S/S        -  SOLIDIFICATION/STABILIZATION
 TCLP       - TOXICITY  CHARACTERISTIC  LEACHATE PROCEDURE
 TICS       - TENTATIVELY IDENTIFIED COMPOUNDS
 UBK        - UPTAKE/BIOKINETIC
UCL95     - UPPER 95th  CONFIDENCE LIMIT
DSGS      - UNITED  STATES GEOLOGIC* ~j SURVEY
VAPE      - VERMILION ASSOCIATION TO PROTECT THE ENVIRONMENT

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                         LIST OF FIGURES
                                                            Page
FIGURE #1

FIGURE #2

FIGURE #3

FIGURE #4

FIGURE #5


FIGURE #6


FIGURE #7

FIGURE #8


FIGURE #9


FIGURE #10


FIGURE #11


FIGURE #12


FIGURE #13


FIGURE #14


FIGURE #15

FIGURE #16


FIGURE #17

FIGURL #18
- SITE LOCATION MAP  	

- SITE DESCRIPTION MAP 	

- SITE DRAINAGE PATTERNS 	

- SURFACE SOIL SAMPLE LOCATIONS	

- BACKGROUND SAMPLE LOCATIONS (SURFACE
SOILS, SEDIMENTS, AND SURFACE WATER) ....

- CONTOUR INTERVALS OF BARIUM IN SURFACE
SOIL	

- SUBSURFACE SOIL SAMPLING LOCATIONS ....

- SUBSURFACE SOIL BORING LOCATIONS NEAR
WELL D-7 	

- SUBSURFACE SOIL BORING LOCATIONS NEAR
WELL G-22	

- SUBSURFACE SOIL BORING LOCATIONS NEAR
WELL G-23	

- SUBSURFACE SOIL BORING LOCATIONS NEAR
WELL SB-30 	

- AREA OF VISUAL CONTAMINATION IN THE
FORMER IMPOUNDMENT AREA	

- AERIAL PHOTOGRAPH SHOWING FORMER
IMPOUNDMENTS 	

- AREA OF ELEVATED VOLATILE ORGANIC
READINGS NEAR WELL G-22  	

- AREA OF DISCOLORED SOIL NEAR G-23	

- AREA OF DISCOLORED SOIL NEAR
BORING SB-30 	

- GROUND WATER MONITORING WELL LOCATIONS .  .

- ONSITE SURFACE WATER/SEDIMENT SAMPLE
LOCATIONS	
                                11

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                        LIST OF APPENDICES
APPENDIX #1

APPENDIX #2

APPENDIX #3


APPENDIX #4

APPENDIX #5


APPENDIX #6

APPENDIX #7
- RESPONSIVENESS SUMMARY

- ADMINISTRATIVE RECORD INDEX

- STATE OF LOUISIANA LETTER OF CONCURRENCE ON THE
  SELECTED REMEDY

- SELECTED ALTERNATIVE COST ESTIMATE

- JUNE 27, 1994 MEMO FROM ECAO REGARDING
  SUBCHRONIC AND CHRONIC RfD FOR BARIUM

- INFORMATION ON BARIUM BIOAVAILABILITY

- TABLES
                               111

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                       THE DECISION SUMMARY

X.   SITE NAME, LOCATION AND DESCRIPTION

The D.L. Mud site is located in a rural area of  southern Louisiana,
approximately  20   miles   north  of  the   Gulf   of  Mexico  and
approximately 3 miles southwest of Abbeville, Louisiana.  The site
comprises approximately  12.8  acres in Range 3 East,  Township 12
South, Sections 60, 58, 38, and 32 in Vermilion  Parish  (Figure #1).
The  property  is  located  in  a  generally rural  area  with  the
surrounding  property being chiefly agricultural  with  livestock
grazing, crawfish  farming,  and crop production.   Residences are
located near the site on Parish Road P-7-31 and Louisiana Highway
335 with a population of approximately 116 people within a one-mile
radius of the site.

The site was originally part of  a  general acquisition comprised of
several parcels  of land  in which this parcel  was included.   The
portion of land that later became the site was originally part of
a  25.56-acre parcel  of  land  that was  used  as  a drilling  mud
facility until  1980.  In  1981,  the  Dowell Division  of The  Dow
Chemical Company (Dow)  purchased a 12.8-acre portion of the larger
tract that contained the barium sulfate based drilling mud blending
operation.    The  remaining portion  of the  tract,  which included
impoundments  used  for  disposal  of  oilfield  exploration  and
production wastes,  was purchased by Gulf  Coast  Vacuum  Services,
Inc. (GCVS),  to support a commercial waste  vacuum truck operation.
This property is also a Superfund Site (GCVS site) and is located
adjacent to the north and west sides of the D.L. Mud site (Figure
#2).

The site is  presently unused, with the exception of  one small shed
in which a local farmer stores equipment.  The site is typical of
ungrazed pastureland,  with sporadic tree  rows along  fences  and
former  irrigation  channels.   The site  is graded  to  drain  and,
except for the former irrigation channels, does  not  contain  any
standing water.  Other than periodic mowing, there are no ongoing
maintenance activities at the site.

The site is  situated on  the  Gulf of Mexico coastal plain and is
generally flat.  Topographic  relief  is  less than  5 feet, at  an
approximate elevation of  10 feet above mean sea level (MSL).   The
site  is divided   into  northern  and  southern portions by  the
abandoned,  leveed irrigation canal that transects the D.L. Mud site
south of the GCVS site.  The northern portion of the D.L. Mud site
is the former drilling mud blending area.   This area is bounded on
its eastern and southern sides  by the  levees associated with  the
former irrigation canal network and the GCVS site on its northern
and western sides.

The area surface soils (0-1 feet) consist of silt loam underlain by
layers of clay, silty clay and sand.   A clay layer approximately 10

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Figure #1

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                                 Figure # 2
                                                                  MONITORING WELL LOCATION
                                                   0     100    200

                                                APPROX SCALE IN FEET
sobRCE MODi?iLi FROM CH3M HILL  1990
 D.L MUD. INC , SITE
ABBEVILLE, LOUISIANA
                                                                                          SITE LAYOUT MAP
                                                                                          Environmental Management. Inc

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to  15  feet thick is located directly  beneath  the surface soils.
Soils under this  clay  layer  consist of silty clay materials to a
depth  of  30 feet.   Below 30 feet  are beds of  fine  quartz sand
interbedded with silt and clay.   Ground water beneath the site was
encountered at approximately 20  feet below the ground surface in
the upper Chicot Aquifer system.

II.  SITE HISTORY AND ENFORCEMENT ACTIVITIES

Relevant site history dates back to 1969 when the site was a part
of a 25.56-acre parcel of land that was sold to Lafayette Highway
Equipment  Sales  and Services,  Inc.   On  May  1,  1975,  Lafayette
Highway Equipment Sales  and  Services,  Inc.,  sold the property to
Gulf  Coast Pre-Mix  Trucking,  Inc.   On  January 11,  1979,  G.H.
Drilling Fluid Services,  Inc.  (later  G.H.  Fluid Services,  Inc.)
became  the owner of the property when  Gulf  Coast  Pre-Mix  Mud
Service, Inc., merged with Gulf Coast Pre-Mix Trucking, Inc.

The site took its present form on October  1,  1980, when G.H.  Fluid
Services, Inc., sold 12.78 acres of the 25.56-acre parcel to Gulf
Coast Vacuum Services,  Inc.  (this later became  the GCVS site).  On
February 11, 1981, G.H.  Fluid Services,  Inc.,  sold the remaining
12.78  acres  to Dowell, a division of The  Dow Chemical  Company.
Ownership of the  site was transferred to Dowell Schlumberger, Inc.
(DSI) in April 1984.  The site was sold to D.L.  Mud, Inc., in March
1985 by DSI.

The 25.56-acre parcel was used for agricultural purposes prior to
1969.  From 1969 to 1980  (prior to the division of the property),
the portion of the property that later became the D.L. Mud site was
used as a barium sulfate based drilling mud storage and formulating
facility.

During  operations  of  the  facility  prior  to  division  of  the
property,  the overall  25.56 acre facility  consisted of  three
impoundments located on the northwest portion of the property now
referred to as the GCVS site and 16 vertical drilling mud storage
tanks located on  the  portion of the property now referred to as the
D.L. Mud site.  The tanks mostly contained drilling mud solids that
had settled from  oil-based and water-based drilling  mud.   Solids
were primarily montmorillonite, barite, hematite, and rust from the
tank walls.  In addition, there were several buildings, including
storage buildings, a  residence, and a vehicle maintenance building,
as well as three underground fuel storage tanks on the portion of
the property that is now referred to as the GCVS site.

Following  the  division and  sale of the  property in  1980,  GCVS
operated its  portion until 1984,  mainly  as a  vacuum  tank  truck
facility servicing the  local oil and gas exploration and production
industry.   The D.L.  Mud site remained relatively inactive  after
1980.  A citizen's complaint through the Vermilion Association to
Protect the Environment  (VAPE) led to  site identification by the

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U.S. Environmental Protection Agency (EPA)  on June 27,  1980.   As  a-      '
result, an EPA Field Investigation Team  (FIT) conducted a prelim-
inary  assessment  and  preliminary sampling  inspection in July  and       j
September  of 1980.    This  inspection  concentrated on  areas of       {
concern that are now most associated with the GCVS  site, however,
at this time, the property was still operated as one facility.          j

On August  18, 1980,  G.H.  Fluid  Services,  inc.,  then  owner  and
operator of  the 25.56 acre  parcel which contained the  D.L.  Mud
site,  sent its first  Notification of Hazardous Waste Activity to       I
EPA.    It  reported  the  generation,  transportation,  treatment,       '
storage  and  disposal  of nonlisted  hazardous wastes  which were
ignitable, corrosive and toxic.  On February 21,  1983, Dow filed  a       I
Hazardous Waste Notification  Form for the  site property with  the       I
Louisiana Department of Natural Resources (LDNR)  indicating  it  was
a generator with  no onsite  disposal.  Hazardous wastes generated       /
were listed as diesel  contaminated dirt and rubble, contaminated       I
diesel  liquid,   contaminated diesel   sludge  and  empty  drums       '
containing wallcote,  fatty acids  and tars.   No permit was required
to operate the facility, however, manifests were required for  any       J
offsite transportation or disposal of wastes.

On April 29,  1983, the site  was inspected by the  LDNR and a letter
of warning  was issued  to Dow informing it that  it was  out of
compliance with  Louisiana  Waste  Management  Program Rules   and
Regulations.   Dow took steps to rectify the  problems and on May  18,
1983, LDNR observed that all  drums  of waste had been removed  and
manifested,  spills had been picked up and drummed for disposal,  and
the site had been regraded with a  levee system installed around  the
tank area.

In October  1983,  Dow  submitted  to the  LDNR a  certification of
inactivity for the site.  On May 23,  1984, the Louisiana Department
of Environmental  Quality  (LDEQ)  notified Dow that,  based  on  its
certification of inactivity,  the  facility would be classified as a
non-handler of hazardous waste.   On  June 6, 1985,  in response to
citizen complaints, an EPA Potential Hazardous Waste Site Form was
prepared for the  site  which was  now under  the  ownership  of D.L.
Mud,  Inc.   It was  noted on this form that there may have been some
activities going on after the  site had been  declared inactive.  On
July 9 and  10,  1985, EPA conducted an inspection with sampling and
on August 16, 1985, a EPA Identification and Preliminary Assessment
Report was  prepared.   The Report  indicates that D.L. Mud,  Inc. was
using the site to salvage equipment  and  tanks  for its operations
elsewhere in Louisiana.   Midnight dumping  was also indicated to
have occurred on the  site.

Based  on  the results  from  the  July 9  and  10,  1985,  sampling
inspection and on  a non-sampling  inspection conducted on September
27,  1985,  it was decided that  final disposition of the site should
be evaluated through the Hazardous Ranking Score (HRS) process.  An
Expanded Site Inspection  (ESI) was performed during several site

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inspections  in 1987.   The  site  information  and sampling  data
collected during the ESI was used to determine that the site posed
a significant  environmental  and  human  health risk.   The site was
proposed for  inclusion on the National Priorities List (NPL)  in
June 1988 and was finalized on October 4, 1989, pursuant to Section
105 of CERCLA, as  amended,  qualifying  the site for investigation
and remediation under CERCLA.

At some point  in 1985  or  1986,  Dow/DSI, by way of agreement with
D.L. Mud, Inc., agreed  to take  responsibility  for the cleanup of
the site in  cooperation with LDEQ.  Between April 18,  1986, and
August 18,  1986, under the supervision of LDEQ, Dow/DSI constructed
a security fence  around the majority  of  the  site.   At the same
time,  Dow/DSI began development of a tank sampling, analysis, and
disposal plan for the 16 onsite tanks.

From April 14,  1987,  through July  11, 1987, Dow/DSI  performed a
remediation  of the  drilling mud  storage  tank  farm under  the
supervision of LDEQ by completing the following tasks:

     •    Removal  of  the tank  contents   and  associated  soils,
          destruction by  incineration, and disposal  of  ash  in a
          hazardous waste landfill.

     •    Decontamination and demolition  of the tanks,  supports,
          and piping.

     •    Removal and disposal of approximately 800 cubic yards of
          contaminated soil  from eight onsite areas, including tank
          pads, one "bare" area, and two areas identified by EPA in
          the southern portion of the site.

     •    Placement of  clean offsite fill material onsite in the
          excavated areas.

The limits of excavation for the  removal action were determined by
an  LDEQ  representative  using  an  HNu   photoionization  meter.
Verification soil samples were collected  from the eight excavated
areas.   On  December  17,  1987,  Dow/DSI  submitted  a Report  of
Decommissioning and  Restoration of the D.L.  Mud site  which was
approved by LDEQ on February 29, 1988.  It  should be noted that the
information used by EPA to  list  the site  on the NPL  was gathered
before the 1987 cleanup activities were completed.

In 1988, EPA  identified over 200 potentially  responsible parties
(PRPs) for the site.    In August  of 1989, EPA Region 6 issued a
General  Notice Letter  to these  PRPs  regarding  their  potential
liability and  a request for information.   Special Notice letters
were then issued to the PRPs in December 1989.  The Special Notice
Letter requested that  the PRPs voluntarily perform or  finance a
Remedial Investigation/Feasibility  Study  (RI/FS).   In  response,
Dow/DSI conducted the RI/FS  pursuant to an Administrative Order on

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Consent  (AOC) signed on June 20, 1990.  The objectives of the RI,
completed  in  December  1992,  were to:   1)  confirm the efficacy of
prior remedial  actions performed at the  site  by Dow/DSl;  and 2)
determine  the nature  of  residual site contamination (if any) and
associated human health and environmental risks.  The objectives of
the FS,  completed in November 1993,  were to determine and evaluate
alternatives  for remedial  action (if any) to prevent, mitigate or
otherwise respond to or remedy any release or threatened release of
hazardous  substances, pollutants, or contaminants from the site.

III. HIGHLIGHTS OF COMMUNITY PARTICIPATION

The requirements of CERCLA Sections 113(k)(2)(B)(i-v) and 177, 42
U.S.C. §§9613(k)(2)(B)(i-v)  and  9617,  were  met during the remedy
selection  process, as illustrated in the following discussion.

A series of community  interviews near the site were conducted in
May 1990.   The interviews included a cross-section of  the area
residents  and  landowners, as  well  as  the  Abbeville-Vermilion
Chamber  of Commerce,  Mayor Broussard of Abbeville,  Louisiana,
members of VAPE, and other civic groups.  A site mailing list was
developed  through the community interview process and is continu-
ally updated as the site activities progress.

In October 1993, an informal Open House was held at the Abbeville
General Hospital to discuss the findings of the  RI/FS.  Fact sheets
summarizing the RI were mailed out to all individuals on the site
mailing list in December 1993.

The RI/FS  Reports  and Proposed  Plan  for  the D.L.  Mud  site were
released to the Public on April 26,  1994.  The documents were made
available  to  the public  in the Administrative  Record File  in the
noted information repositories:   Vermilion Parish Public Library,
Abbeville,   Louisiana;   Louisiana   Department   of  Environmental
Quality,  Baton  Rouge,   Louisiana;  and  the  U.S.  Environmental
Protection Agency Region  6 Library, Dallas, Texas.   A summary of
the Proposed Plan and the notice of availability of these documents
and Administrative  Record  File  was  published in  the  Abbeville
Meridional  and  the Kaplan Herald.    In  addition,  a. fact  sheet
summarizing the Proposed Plan of Action for the D.L. Mud site was
mailed to the site mailing list on April 26,  1994.

The EPA  held a public comment period regarding the RI/FS, Proposed
Plan and Administrative Record from April 29, 1994, through May 28,
1994.   During this initial public comment period, a formal  public
meeting  was  held  on  May  10,  1994,  at the   Abbeville  General
Hospital.   Representatives from the  EPA presented  the  remedial
alternatives,   the   EPA   preferred  alternative,   and   answered
questions.   All questions and comments were recorded  to be included
in the Responsiveness Summary.

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A  response  to all  comments  received during  this 30 day public
comment period, either written or verbally expressed at the public
meeting,  is   included   in  the  Responsiveness   Summary.    The
Responsiveness Summary  is  included as part of the  ROD  (Appendix
#1).

This decision  document  presents  the  selected  remedial action for
the  D.L.  Mud  site,  in Vermilion  Parish,  Louisiana,  chosen  in
accordance with  CERCLA, as amended  by SARA  and, to the extent
practicable, the NCP.  The decision for this site is based on the
Administrative Record.  An index for the Administrative  Record is
included as Appendix #2 to the ROD.

IV.  SCOPE AND ROLE OF RESPONSE ACTION

The remedy to address the identified threats at the D.L.  Mud site
under this ROD is addressed as one operable unit.   This is the only
and  final  operable  unit planned  for  this site.   As  mentioned
earlier, a State-lead removal  action was  completed  in 1987 which
addressed  the majority of problems identified  during   the  NPL
listing process.

The studies undertaken  at  the D.L. Mud site  have identified low
level risks which require remedial actions to address.   Low level
risk materials are sources of contamination that could be kept in
place by capping and pose  a  low risk.  For example, the surface
soils identified onsite with  residual elevated  levels of barium
contamination are considered a low level risk because the associ-
ated risk is  relatively low  (less than an order of magnitude in
comparison to  accepted  action  levels) and because these  residual
contaminants could be  kept  in place with a capping remedy,  thus
eliminating the potential for migration or ingestion.

In addition, EPA has determined that  there is an unknown  potential
risk related to the source materials identified in the subsurface
soils in  the  former impoundment areas.   This potential  risk is
related to the unknown capacity for these contaminants to migrate
into the ground  water and the unknown  impact these contaminants
would have on the quality of the ground water.

The remedial objective determined to be necessary at  the Site is to
preserve  human  health   and  the  environment   by eliminating  or
reducing  identified  and/or  potential  risks   by preventing  the
ingestion  of  barium  contaminated  soils  and  by  reducing  the
potential  for migration of  contaminants from both surface  and
subsurface soils to the ground water.  Additional specific remedial
objectives determined to be necessary at the D.L. Mud Site are:

*    Primary:       Preserving the Site for non~residential  uses
                    and  reducing the potential  for  migration to
                    ground water of site-specific contaminants.

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*    Secondary:     Restoring the Site for unrestricted uses.

Future  land use  assumptions used  to  formulate the  primary and
secondary remedial objectives were  based in part on two important
factors.  First, because the Site is presently an abandoned,  light
industrial use facility, with no human inhabitants and located next
to the GCVS Superfund Site,  it seems reasonable that this type of
land use will  continue.  Second, because  there currently are no
land use restrictions affecting this property and residential  areas
are located nearby, it is possible that the property could be used
as a residential location in the future.
V.   SUMMARY OF SITE CHARACTERISTICS

The D.L. Mud site is situated on the Gulf of Mexico coastal plain
and is generally flat. Topographic relief is less than 5 feet, at
an approximate elevation of 10 feet above MSL.  The site is divided
into  northern and  southern portions  by  the  abandoned,  leveed
irrigation canal that transects the D.L. Mud site south of the GCVS
site.   The  northern portion of  the  D.L. Mud  site  is the former
drilling mud blending  area.  This  area is bounded on its eastern
and  southern  sides  by  the levees  associated  with the  former
irrigation canal network.

The southern portion of the site  is poorly drained, with slopes of
one-half percent  or  less toward the  south,  and  is  bounded  by a
perimeter levee system.  Grading  in this  portion of the site still
reflects its former use as a rice field.  The northern portion of
the site contains three structures:  one shed with a concrete slab,
one concrete  slab associated with a  former shed,  and  one small
concrete slab that was formerly a pump  pad within the drilling mud
blending tank building.

Features that have been added in  the vicinity of the D.L. Mud site
include two berms across the drainage ditch located on the western
edge of the GCVS site.   These berms were  constructed during a 1990
EPA Interim Remedial Measure to provide a secondary impoundment to
collect overflows from GCVS site impoundments.   A  six  foot tall
chain link fence was  also added around  the southwestern portion of
the GCVS site  during the 1991  EPA RI  that was conducted  at that
site.

Vermilion Parish has  a humid, subtropical climate. The mean annual
precipitation  is  approximately  60  inches.   Pan evaporation  is
approximately 60 inches per year.  Potential evapotranspiration is
reported to  be  between 45  and  48  inches  per year and  actual
evapotranspiration is reported to be between 40 and 43 inches.  The
annual  mean  relative  humidity  is  75  percent.    Although  no
temperature data were found for Abbeville, the mean temperature in
nearby New Iberia was 69.4°F in  1990.   Wind data collected at the
Lafayette,   Louisiana  airport  show  winds   to  be  predominantly

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northerly or  southerly.   The  highest wind speeds  are typically
reported-from the south.

In 1990,. Abbeville  received  approximately  47  inches of rainfall,
which is about 14 inches below  normal.  Much of this variation can
be attributed to below average rainfalls from late spring to late
fall for the area.   Although  the area experiences extreme rainfall
events, the entire  D.L.  Mud  site  has  been  determined to be above
the 100-year floodplain.

SURFACE WATER

Regionally,  surface drainage is from  north to  south.   Because of
low relief,  this area  is poorly drained, and ditches are used to
promote drainage from agricultural land.  These ditches eventually
interconnect with major  tidally influenced waterways such as the
Vermilion River.  Canals were also built in the Abbeville area and
operated commercially  for irrigation  water transmission from the
Vermilion River, which is a little over one mile east of the site.
The canal located along  the  eastern site boundary was fed by the
Vermilion River and used for commercial irrigation until the late
1970s.   The canals have been  replaced by wells  as a  source of
irrigation water.   In  some areas,  especially south  of Abbeville,
the Chicot Aquifer, which is the principal  source of drinking and
irrigation water in the area, is recharged by the Vermilion River.
This recharge occurs during the summer and fall, with discharge of
ground water  to the river  occurring during the spring.   Aquifer
recharge typically  exceeds discharge  to the river.   Seepage from
the Vermilion River along a ten mile section south of Abbeville is
reported to be about 25 cubic feet per second.

There are no surface water monitoring stations between the D.L. Mud
site and the Vermilion River.   The  United States Geological Survey
(USGS) operates a gaging  station on the Vermilion River at the town
of Perry, approximately two miles east of the site.   USGS records
show  that this gaging station is tidally  influenced.   Recorded
discharges have ranged from a maximum positive flow of 15,800 cubic
feet per second to a maximum  negative  flow of 2,800 cubic feet per
second.  Periods of little or no flow are also recorded.

The LDEQ lists  the  Vermilion River as not  meeting  its designated
water quality  uses  for primary (swimming,  skiing,  and prolonged
body  contact)  and  secondary  (fishing,   wading,   boating,  and
incidental/accidental  body  contact)  recreation  or  for  fish and
wildlife support from its headwaters to the Intracoastal Waterway.
From  the Intracoastal  Waterway   to  Vermilion  Bay,  the  river
partially supports fish and wildlife use.   According to LDEQ, the
Vermilion River suffers from dissolved oxygen depletion, elevated
fecal coliform levels, and high turbidity.

Surface  runoff from the northern portion  of  the  D.L.  Mud site
collects in  the unnamed drainage ditch that transects the GCVS site

                               10

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and proceeds  to  the northeast where the ditch merges with Coulee
Galleque.   The Coulee  Galleque  continues east until  it forms a
confluence  with  Coulee  Kenny, which flows  southeasterly  to the
Vermilion River above the town of Perry.  The southern portion of
the site drains southward, eventually joining a highway ditch south
of the  site and  ultimately  flowing through the Noel Canal to the
Vermilion River below the town of Perry.  Figure #3 shows general
drainage patterns from the D.L. Mud site.

REGIONAL GEOLOGY

The  D.L. Mud site is  located  within  the  Gulf  Coastal  Plain
physiographic  province. The  area  is  west  of the axis of  the
Mississippi structural  trough and  north of the Miocene Axis Gulf
Coastal Geosyncline. Underlying the site are overlapping, coastal-
thickening wedges of fluvial,  deltaic, and marine sediments.  These
sediments are of the Pleistocene  age  and were deposited  by the
ancestral Mississippi River that derived sediment and flow from the
central  part  of  the North American  Continent.    These deposits
consist  of  extensive  beds of clay,  sand,  or  sand and  gravel
extending to depths of greater than 2,000 feet offshore in the Gulf
of Mexico.  In the Abbeville area,  these deposits extend  to depths
of about 1,000 feet.

Generally, the Pleistocene deposits have massive lenticular sands
separated by laminated clays.  These deposits have been intersected
and reworked  by the meander-belt  streams  which have formed relic
channels, and point-bar deposits, which are overlain by back swamp
clays.  The back swamp clay (hardpan) typical of the near surface
deposits of the  rice field areas of southwest  Louisiana forms a
laterally extensive blanket  from  Lake Charles to  Lafayette  and
southward.   These  low-permeability  clays are generally 50  feet
thick or less and may be overlain by topsoils.

The area  topsoils  (0-1  feet)  are  largely Patoutville  silt  loam
formed from deposits of the Pleistocene Prairie Formation and are
underlain by  layers of clay,   silty  clay  and sand.   This nearly
level to very gently sloping loamy  soil (0 to 3 percent slope)  has
a medium acid, dark, grayish  brown silt loam surface of five to
eight inches.  The subsurface layer is a  strongly acid, grayish
brown silt loam.   The subsoil is a medium,  acid dark grayish brown,
silty clay loam.   This soil  is somewhat poorly drained, and runoff
is medium.  Because of  poor drainage and engineering properties,
use of the Patoutville soils is generally limited to agriculture.
The United States  Soil Conservation Service lists the potential for
pasture, crop, and pine forest lands as high.

Geotechnical testing indicate  that soils underlying the site are of
low permeability.  Of the six samples tested for permeability,  five
have values  less  than lxlO"7cm/sec,  which is the  maximum perme-
ability  acceptable  for  Resource  Conservation  and Recovery  Act
(RCRA) cap and cover systems.   Soils examined during the drilling

                               11

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   Figure //
APPROXIMATE SCALE: 1'= 1425'         PHOTO DATE 2/24/90

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of  subsurface borings and wells  indicate  that alluvial deposits"
consisting  of clay,  silt, and  sand exist to depths of at least  50
feet -across the site.   The shallow soils (to a depth of approxi-
mately  30  feet)  were primarily  clay  and silty  clay classified
visually as CH under the Unified Soil Classification System.  Below
30  feet are  beds  of fine quartz sand  interbedded  with silt and
clay.  The subsurface is generally saturated below approximately  20
feet.
REGIONAL HYDROGEOLOGY

The major  hydrogeologic unit in the site  vicinity is the Chicot
Aquifer System.  This aquifer has an areal  extent of approximately
2000  square miles  and is the  principal source of  ground water
supply within the Abbeville area.  The shallow sands of the upper
Chicot Aquifer are generally considered unconfined, with a perched
water table near land  surface.   The  base of fresh  water  in the
Chicot aquifer varies from 400 to 600 feet  beneath ground level in
the Abbeville area.

Ground water beneath the site was encountered at approximately 20
feet below the ground surface (-10.0 feet MSL) which is typical of
conditions  in  the upper sand  unit  of  the Chicot  Aquifer  in the
Abbeville  area.   The direction of flow  in the  Abbeville  area is
toward the  northwest at a  gradient  of  approximately 0.0002 ft/ft
resulting  from  the large  cone of depression created  by  aquifer
withdrawals  from large pumping centers  such as  the cities of
Lafayette and Lake Charles.  Regional annual fluctuations in water
levels for the upper sand of the Chicot aquifer range from one to
two feet in the Abbeville area.  In some areas, especially south of
Abbeville,  aquifer  recharge  by the  Vermilion  River occurs during
the summer and fall, with discharge to the river during the spring.
Assuming  a hydraulic  conductivity of 112  ft/day,  a  hydraulic
gradient of 0.0002  ft/ft,  and  an intergranular  porosity  of 0.30,
the estimated regional  flow velocity in the vicinity of Abbeville
would be 0.07 ft/day.

Water level measurements  taken at D.L. Mud and GCVS  site  ground
water monitoring wells  show that ground water flow in the shallow
sand  is  toward  the north  at a gradient of approximately  0.0002
ft/ft, which is  typical for the Chicot  aquifer in the Abbeville
area.   Small variations in  water levels indicate that there may be
some localized flow of ground water between the GCVS and D.L. Mud
sites.   This  mounding/depression  may  be associated  with  the
variability of permeabilities and recharge rates for the alluvial
deposits  and could potentially  be influenced  by  the  surface
impoundments located on the GCVS site.

In accordance with EPA's Guidelines for  Ground Water Classification
under the EPA Ground Water Protection  Strategy,  (December  1986) .
the ground  water beneath the  site  is  classified  as a Class IIB

                                13

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ground water  because the  ground water is  currently used  or is
potentially available for drinking water or other beneficial uses.
Ground water in the area is used for  drinking water purposes  (there
are at least 25 residential wells within one mile of the site) as
well as for agricultural  purposes (irrigation and crawfish ponds).

The ground water found at shallow depths (i.e., RI monitoring wells
screened at 20 feet) is turbid  from  the  clays and  silts  in the
formation  and  would  be inappropriate  for drinking  or irrigation
because of the potential for plugging of pipes and fittings.  While
there is no impermeable barrier between the upper and lower reaches
of  the  aquifer, ground  water supply  wells  completed  to  deeper
depths in this aquifer (i.e., 80 feet to 120 feet)  are capable of
producing water virtually free of visible solids.


KNOWN OR SUSPECTED SOURCES OF CONTAMINATION

The sources for the contamination that  has been identified at this
site are mostly related to the nature of the business that operated
on the site.   As mentioned earlier, this  location was used as an
oil  field  drilling  mud  formulation  and  restoration  facility
servicing  the  local  oil and   gas  exploration  and  production
industry,  including  operations conducted  offshore in the Gulf of
Mexico.  Operations  involved the use  of numerous  large tanks and
pits used for mixing and storage of  raw materials and wastes.  In
addition, the neighboring GCVS facility was a service facility for
the  oil  and  gas   industry,  concentrating on  vacuum tank  truck
transportation operations.  It is also known that illegal dumping
at both Superfund sites occurred during the active life of the D.L.
Mud and GCVS facilities.

The type of materials  and wastes that were generated,  stored or
disposed of at  this  site  are  generally defined as  "non-hazardous
oilfield wastes"  (NOW wastes) which  are  exempt from regulation
under  RCRA,  the  current  federal law  that  regulates  hazardous
wastes.  These wastes  are generally regulated by the individual
States in which they  are  generated.  However, because these wastes
contain  hazardous  substances,   they  can also be  evaluated  as
potential problems and addressed under the Superfund program.

All known contaminant sources were removed from  the site during the
1987 site remediation under the direction of the LDEQ.  This action
included:

     *    The  removal and offsite incineration of  any  remaining
     drilling  muds being stored in any of  the 16  then existing
     product storage tanks and associated soils.

     *    The removal and offsite disposal of the 16 storage tanks,
     their bases and any associated  roof,  piping,  etc.
                                14

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     *    The removal and off site disposal of areas of contaminated
     soils,  located on  the  site,  but  associated with suspected
     fugitive dumping by undisclosed parties.

     *    The backfilling and grading of all excavations to conform
     to the natural lie  of the land.

At  the  initiation of the RI  in 1990,  it was  assumed that only
residual contamination would remain at  the site.   During the RI,
several  subsurface areas  were identified as  potential  "source
areas"  based on either  visual  and/or  vapor  identification  of
obviously contaminated materials not indicative of native soils.

CONTAMINATION CHARACTERIZATION

This  section   describes  the  nature   and  extent  of  residual
contamination at the D.L. Mud site for the following media: surface
soil  and  subsurface  soil,  ground  water,  surface  water,  and
sediment.  Subsurface soils have been  subgrouped to include five
distinct categories:  four "source  area"  sample  groups and a fifth
"non-source area" sample  group.  Three source areas were identified
during subsurface boring activities near monitor wells G-22 and G-
23 and soil boring SB-30.  The fourth source area was identified as
a  former  impoundment  area  in April  1992  from  a 1974  aerial
photograph.

The nature of site residual related contamination was evaluated by
a statistical comparison  of onsite media analytical data to of f site
(background)  analytical data.   A summary of the evaluation of the
various media is presented in more detail in following subsections.

In  general,  inorganic parameters  were  detected  in much  greater
frequency than  organic parameters  for  both onsite and background
samples.  Typically, organic compounds were detected in one or two
samples per media grouping for both onsite  and background samples.
The  exceptions  of this generality are  for   common  laboratory
(acetone,   methylene   chloride)    and   sampling   (phthalates)
contaminants.   These  data indicate that the nature  of  residual
contamination is generally limited  to inorganics, although organic
residual  contamination  may  exist  at  localized  areas.     The
determination  of  the  presence  of  chemical  specific  residual
contamination was made by statistically comparing background sample
sets to  the  onsite sample sets for  each media evaluated  at the
site.  If that chemical was found to be significantly higher onsite
than in background, it was considered to be indicative of  onsite
residual contamination of that media.    Not all  contaminants  of
concern are contaminants  that drive the  risk or the need to conduct
remedial actions  at the  site.  The contaminants most  critical  to
risk are discussed in detail  in Section VI of this ROD.
                                15

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 Surface -Soils


 A  total  of  30  composite  surface soil  samples  (0-1  feet) were
 collected to evaluate potential residual contamination during the
 RI   (Figure  #4).    Sample  locations  were  determined  based  on
 historical uses  of the site and on c  random,  grid basis.   Eight of
 these  samples were  background samples  collected from  soils  of
 similar nature at privately owned farms north and northwest of the
 site (Figure #5).

 The  onsite surface soil evaluation concentrated  on two areas: the
 southern  portion, which is the area below the bisecting canal that
 was  generally not used during the operations  at the site  but which
 might  have been the location of  indiscriminate  dumping; and the
 northern  portion, which  is  above the bisecting canal and was the
 location  of  the operations area, storage tanks  and  focus of the
 1987,  State-lead cleanup.

 Table  #1  summarizes surface  soil  residual  contaminant  sample
 results above background values by sample location.  Surface soil
 samples  G-23  and HA-1  through  HA-7 were used  to  evaluate  the
 southern  portion of  the property.   Ten  inorganic compounds were
 reported  above maximum background in this area.  The results show
 that the number and concentration of inorganics generally decreased
 with distance  from  the canal  that transects  the property.  The
 highest concentrations of inorganics are located near HA-4, HA-5
 and  HA-6  and decrease  to background  levels further south.   In
 general,  -chese data  indicate that residual inorganics are located
 in the portion of the property closest to previous site activities.

 Surface soil samples HA-8 through HA-14 and G-20  through G-22 were
used to evaluate the  impacts of D.L. Mud and GCVS  operations  on the
northern  portion of the property.  Table #1 shows that a total of
 10 inorgp.nic compounds were detected in this area. Samples located
within the former process area  that  was  not  excavated during the
 1987 remedial activities at the site  (HA-8, HA-10, HA-ll, G-20,  G-
21,  and  G-22)   show highest   residual  concentrations.    Lower
concentrations  of  inorganics  were   reported in  the  remaining
samples.

The  analytical  data for surface soils  indicate that  residual
inorganic  contamination  appears to  be  centered near  the  former
storage tank area and also  downstream of surface runoff from the
GCVS site, with lesser concentrations occurring at a distance.  In
keeping with the former  use  of  this area as a barium sulfate based
drilling  mud  blending  facility,  barium is  the  most  widespread
residual  contaminant.    Figure  #6  graphically   illustrate!  the
 lessening  of barium  concentration at greater  distances  from the
 former storage tank area and the reported rodeo area located  in the
northeast portion of the GCVS  site.   In addition, testing was done
to speciate the form of barium present in the surface soils.

                                16

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                               Figure # 4
        PARiSr ROAD &-7-31
                             HA-6    HA-7
                                                       NORTHERN SITE FENCE
                             D.L MUD,
                            INC..  SITE
SiTE BOUNDARY
                                                     LEGEND


                                                   MONITORING WELL LOCATIONS


                                                   SAMPLE LOCATIONS
                                             NOTES: LOCA J10NS ARE APPROXIMA IE.
                                    SURF1C1AL SOIL SAMPLING LOCATIONS
                                  3.L. MUD, INC., SITE, Abbeville, Louisiana

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    Figure # 5
APPROXIMATE SCALE: 1'= 1425'
PHOTO DATE 2/24/90

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                                    Figure // 6
                                     W.OOOppm
 0           300 FEET


APPRO*. SCALE
    502
    SOS
    506
    ST6A
    507
    5C£
    SOS
    HA;
    HA 2
    HA 3
    *->A4
    HAS
    HAS
    HA 7
    HAS
    HA 9
    HA1C
    HAn
    HA',2
    HA13
    HA14
    G-20
    C-21
    C-22
    C-23
  :ssoo
    zee
!    J70
!    272
,    270
!   6900
i   8300
   6930
   7150
  72200
   9120
   7S90
  HJOO
   7630
  Hi JO
  10100
  1.3500
                          l.OOOppm
                                  \
HA-1
                                                                    /
                                                                       i.OOCpprn
                                                                          /
                                                                          I
                                                                          I
                                                                         J
                                                                        / SD2
                                                                      /   °
                                                                   /
           -  MONITORING WELL LOCATIONS

           -  HAND AUGER SAMPLE LOCA TiONS

       o   -  SEDIMEN T SAMPLE LOCA TIONS


NOTES:  1.  LOCATIONS ARE APPROXIMATE.
       2  CONTOUR INTERVALS ARE BASED ON ANALYTIC*L
         DATA GENERATED FROM S'JRFICAL AND SEDIMENT
         SAMPLES.
                                      }UR INTERVALS OF BARIUM IN SURFIC1AL SOIL rJ
                                           D.L MUD. INC., SITE, Abbeville, Louisiana

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Samples  ..collected  from  the  site  showed  that  barium  sulfate
accounted for approximately 92 percent of the total barium present.

No  organic  contaminants  were detected  at concentrations  above
background in any of the surface soil samples.

Subsurface Soils

Numerous subsurface soil samples and soil borings were taken during
the RI.   The locations of these samples and  borings  were chosen
based on  several factors  as  discussed  below.   No  subsurface soil
background samples  were collected.   Comparisons  with background
were made using surface soil background results.

Five soil boring locations (SB-1, 2, 3,4 and  5) and six trenching
locations  (TR-1,  2,  3,  4,  5, and  6) were  established at  the
approximate points shown on Figures #7 and #12  to evaluate the risk
associated with  potential subsurface  soil  contamination in  the
former site  process areas.   Four of these  locations (SB-1,  SB-3,
SB-4 and SB-5) were established to confirm soil excavation limits
for the 1987  site remediation effort. The fifth soil boring (SB-2)
was located to coincide with  the approximate center of a potential
surface  impoundment tentatively  identified by  a  1975  EPA aerial
photograph.   The  six  locations  for   trenching were   located  to
coincide with the approximate centers of six impoundments identi-
fied in an aerial photograph dated 1974 (Figure #13).

Eleven additional hand  auger soil borings  (D-7A through D-7G and
SB-6 through SB-9)  were completed to  depths  of approximately 10
feet  at  the  approximate  locations shown  on  Figure  #8.    These
borings were completed to visually evaluate the extent of subsur-
face contamination under the adjacent GCVS site near the D.L.  Mud
site property line.  No visual  contamination was noted beneath the
D.L.  Mud  property.    No  samples were collected  for  chemical
analysis.

In addition, seventy three subsurface soil borings were completed
to depths ranging from 3 to 15 feet deep.  The borings were cored
using the vibracore technique near wells G-22  (Figure #9) and G-23
(Figure #10)  to evaluate the extent of two potentially contaminated
areas identified by an EPA contractor and to address concern over
the  potential existence  of  other non-identified  source  areas
onsite.  The subsurface soils near well G-22 were  investigated by
the completion of fifteen  borings.    Eight borings were  placed
equidistantly around the  well  pad.  Seven  other boring locations
were  located based on field  readings of  organic  vapors.    The
subsurface near well G-23  was  investigated  by a total of fifteen
borings.   Eight of the borings were  located equidistantly around
the well pad, and the  remaining seven were located based on visual
observations of darkened soil since no organic vapors were noted.
Soil borings SB-10 through SB-37 were completed on  a grid system at
approximate  100 foot centers to supplement previous site soil

                               20

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                               Figure # 7
     SCALE

--- 5- ?3AD P-7-31
    SEE FIGURE
SE&flGURE * 12
       E FIGURED 8
 SEE FIGURED 10
                                                           SEE FIGURED 9
                                                       NORTHERN  SITE FENCE
                       SB15  S816 SB%
                       D.L  ML/D.
                         .,  S/7F
                                           APPROXIMATE
                                           SITE BOUNDARY
                                                      LEflENP

                                                  -  SAMPLE LOCATION


                                               NOTE: LOCATIONS ARE APPROXIMATE
                                        SUBSURFACE SOIL BORING LOCATIONS
                                      D.L. MUD, INC., SITE, Abbeville, Louisiana

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                          Figure g 8
                            GULF  COAST
                        VACUUM  SERVICES  SITE
       25 FEET
SCALE
                       D-7C
                                                  SB-9
              D-73
D.L. MUD.
INC., SITE
          D-7D
                                                    SB-B
                                                     D-7E
                                     S3-6
                      F.D. 1/2" IRON ROD
                      N 9,592.17
                      E 9817.06
            LEGEND
 ©   -   SUBSURFACE SOIL BORING LOCATION
     -   MONITORING WELL LOCATION
 NOTE: LOCATIONS ARE APPROXIMATE
                    SUBSURFACE SOIL BORING LOCATIONS NEAR WELL D-7
                                 D.L. MUD, INC., SITE, Abbeville, Louisiana

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       Figure // 9
   S-5
                                    LEGEND
                             -  AUGER/V1BRACORE LOCATION


                                SOIL BORING w/LABORATORY
                                SAMPLE


                             -  MONITORING WELL LOCATION
                      NOTE:  LOCATIONS ARE APPROXIMATE.
SUBSURFACE SOIL BORING LOCATIONS NEAR WELL G-22 ryr^i
              D.L. MUD. INC., SITE,  Abbeville,  Louisiana

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                         Figure t 10
        W FEET
SCALE
    CONCRETE
    WELL PAD
                                                             x  E5
                                                 E4
                                                 x
            LEGEND
E3
 x
-   BORING (POSTHOLE) LOCATIONS
     -   VIBRACORE LOCATION
        SOIL BORING w/LABORATORY
        SAMPLE
     -   MONITORING WELL LOCATION
 NOTE: LOCATIONS ARE APPROXIMATE
                   SUBSURFACE SOIL BORING LOCATIONS NEAR WELL  G-23
                                 D.L MUD, INC., SITE, Abbeville, Louisiana

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                            Figure # 11
0    15    JO FEET
   SCALE
                SS-JJ •
                            H'
                           G*    F
                                      SS-J2-
                                           ©C
SB-30
K
                                           •J
                                                                      •S8-31
                                                    VISIBLE DISCOLORATION
                                                    AT LAND SURFACE
               LEGEND
        -  AUGER/V18RACORE LOCATION


        _  SO/L BORING w/LABORATORY
           SAMPLE
  /VOTES:  1. VD=V!sto/e Disco/oration
          2. LOCATIONS ARE APPROXIMATE
                  SUBSURFACE SOIL BORING LOCATIONS NEAR BORING SB-30 f-'.'f',/.'/III
                                   D.L MUD, INC., SITE, Abbeville, Louisiana ^———

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Figure // 12

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Figure  ill3

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borings.   An  additional fifteen  borings were  placed near  the
location" of  SB-30  (Figure #11)  in response to  low  level  organic
vapor readings and visual observations of darkened soil.

The following sections summarize subsurface soil results reported
above background values for each sample location.  Determination of
the potential presence and extent of subsurface soil contamination
is presented  in  six groupings according to the  purposes  of each
investigation.

1) Confirmatory Samples Collected Beneath Areas of Historical Use.
Subsurface soil samples SB-1, SB-3, SB-4, and SB-5 were analyzed to
evaluate residual subsurface  contamination beneath areas excavated
during  the  1987  site remediation.    A  comparison between  the
shallower and deeper samples from borings SB-1,  SB-2, SB-3, SB-4,
and SB-5  shows little difference between the analytical  results
with depth (see Table #2) .  This finding tends to  indicate that the
soils sampled are indicative of native materials.

Sample SB-2  was  collected to determine the presence of residual
subsurface contamination  from a surface  impoundment tentatively
identified from an EPA  aerial photograph.  No visible indication of
waste material was noted during placement of this  boring.  However,
the trenching activities discussed later did locate discolored soil
near this boring.

Samples HA-3, HD-1 and  HD-3 were collected from beneath the surface
of an area in the southern portion of the site.   It was felt that
this area could  have  been used for  waste disposal  in  the past.
Table #2  shows that residual contaminants in deeper samples  are
approximately  the  same or  decrease  with depth.   Therefore,  it
appears that there has  been little impact on the subsurface of this
portion of the site from historical operations.

2}  Samples collected  From  Monitor Well  Installation.    Results
presented  in Table  #3  for subsurface  soil samples  collected from
wells  D-6,  D-7, G-20  and  G-21  while  constructing  new  site
monitoring wells show the presence of  six residual inorganics above
background concentrations.   The wells  with  multiple samples with
depth show a general trend of decreasing inorganics with depth.

3) Area Near Well G-22.  Fifteen soil borings  were completed near
well G-22 (see  Figure #9  and  #14)   to evaluate  the  extent  of
apparent subsurface  contamination noted while installing the well.
Field results  show  that  the highest organic vapor  monitor (OVM)
reading was detected at boring G-22B.  A concentration of 268 ppm
was detected by OVM  at a  depth interval of 11.5 to 12.0 feet.  The
potentially  contaminated  soil did not display   visible signs  of
contamination, but did have  an odor similar to that of a petroleum
product.  A second round  of borings extending to  depths of 15 feet
were augered/vibracored centered around boring G-22B to determine
the lateral extent of contamination.  The potentially contaminated

                               28

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                             //  14
                                     n.o
                                    8-8.5'
-   AUGER/V! BRA CORE LOCATION

    HIGHEST  OVM READING (ppm)
    and DEPTH INTERVAL (FEET)
    SOIL BORING w/LABORATORY
    SAMPLE
    AREA OF ELEVATED VOLATILE
    ORGANICS READINGS
                                   NOTE: ALL LOCATIONS ARE APPROXIMATE.
AREA OF ELEVATED VOLATILE ORGANICS READINGS NEAR WELL G-22
                          D.L  MUD, INC., SITE,  Abbeville, Louisiana    -

-------
area  was  found  to  be  bounded   laterally  within  an  area  of
approximately 3200 square feet.  The potential contamination within
this area was found between the depth  interval of 3.0 to 14.0 feet
with the highest organic vapor readings occurring between the depth
interval of 6.5 to 12.5 feet.

Table  #4  shows  that  "source" samples,  collected  from  depth
intervals  of  highest organic  vapor readings,  tend  to  show the
presence of  inorganics  and organics  above  background  concentra-
tions.  Five organics (2-methylnaphthalene, dibenzofuran, fluorene,
naphthalene, and total xylenes) and two inorganics (beryllium and
zinc)  are  reported  above  background  for  all source  samples.
Samples collected to  bound  the vertical  and horizontal extent of
contamination were generally found to have concentrations less than
source area sample values for residual inorganics and without the
presence of organic residual contaminants.

4) Area Near Well G-23.  Field results  indicate that of the fifteen
borings  completed near  well  G-23, the  highest OVM reading was
detected at boring G-23E  (see Figures #10 and #15).   A concentra-
tion of 0.4 ppm was detected by OVM at a depth interval of 2.0 to
2.5  feet.   The  potentially contaminated soil  has  a  dark  brown
appearance.   The potentially  contaminated  area was  found  to be
bounded laterally within an area of approximately 1000 square feet
and had a peaty nature.   Due to the peaty nature of this material,
organic vapor analyzer (OVA) readings could not be used to evaluate
the  extent  of  residual  contamination  since  this  instrument
registered  the  presence  of naturally  occurring methane.    The
vertical extent  of the  potentially contaminated area was  found
between the depth interval of 2.0 to 3.0 feet.

Table #5 shows "source" samples collected  from discolored  soils
near well  G-23 to  contain  only inorganic  residual  contaminants
above background values.  Of the inorganics, only lead and mercury
were reported above background for all source samples.   Antimony,
arsenic, and  selenium were reported above background  for one or
more samples.  Those  samples collected to bound the  vertical and
horizontal extent of contamination  show concentrations of residual
contaminants below source sample values.

5) Area Near SB-30.  Fifteen borings were augered/vibracored near
SB-30 to determine the lateral and  vertical  extent  of  visible
contamination  (see Figures  #11 and  #16).   OVA  readings  were
detected in all  borings near SB-30, with the exception of SB-30.
There were no  organic  vapors detected by the  OVM with the exception
of SB-30.

SB-30 was  found  to  have visible contamination as well  as OVA and
OVM  readings  as  high  as  660   and  0.9 ppm,  respectively.    The
potentially contaminated  area  was  found to be  bounded laterally
within an  area  of approximately 7000  square feet.   The  vertical
extent of the  potential  contamination was found to range to a depth

                                30

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        10 FEET
SCALE
    CONCRETE
    WELL  PAD
                             Figure ff 15
                                                   E4
                                                   x
                                                              x  E5
              LEGEND
         AREA OF DISCOLORED SOIL
£3
 x
-   BORING  (POSTHOLE) LOCATIONS
 E1   _
         VI3RACORE LOCATION
 ©   -
    SOIL BORING w /LAB ORATORY
    SAMPLE
         MONITORING WELL LOCATION
 NOTE:  LOCATIONS ARE APPROXIMATE
                             AREA OF DISCOLORED SOIL NEAR WELL C-23
                                  D.L. MUD, INC.,  SITE,  Abbeville, Louisiana

-------
                                      Ib
  15    30  FEET
SCALE
       S8-30
         0.9
        1-1.5'
       VC at 20'
              SS-JJ  •
                 o
                0-10'
/
0
VC at 10',
P
0
0-3' •
NVC
Ys>
v\
Xj




 H
             LEGEND
     -   AUGER/VIBRACORE LOCATION
                                                                        • SB-31
                                                    VISIBLE  DISCOLORATION
                                                    AT LAND SURFACE
 0.4
0-6'
SOIL  BORING  ^/LABORATORY
SAMPLE

HIGHEST OVM READING (ppm)
and DEPTH INTERVAL (FEET).
NOTES:  1. VD=Visible Discoloration.
        2. NVC=No Visible Contamination.
        3. LOCATIONS ARE APPROXIMATE.
                          AREA OF DISCOLORED SOIL  NEAR  BORING SB-30
                                  D.L. MUD, INC., SITE,  Abbeville, Louisiana

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of  3.5  feet, with  an outcrop of  the substance  located  at land
surface approximately 70 feet southeast of SB-30.

Table #6  shows that  selenium and  zinc  are the  only inorganics
reported above background  values  for all  "source" samples.  Lead
and mercury are also reported above background values but at lesser       r
frequencies.  Of the  samples  collected to bound the vertical and       1
horizontal  extent  of  contamination, reported  concentrations  of
residual  contaminants  generally  are  below those  for  "source"
samples.                                                                [

6) Former  Impoundment Area.   Six trenches were completed in the
area where six former impoundments were identified by EPA in April       j
1992 on an aerial photograph dated 1974  (Figure  #13).  The approx-       |
imate centers  of  the  former  impoundments were field  located  to
coincide with the approximate centers of the impoundments identi-       ,
fied on the 1974 photograph.  Discolored soil, OVA  and OVM readings       I
were detected in Trenches 1, 2, and 3.  OVA readings  ranged to 160       '
ppm in Trench 1, 320 ppra in Trench 2, and  greater  than 1000 ppm in
Trench 3.   OVM readings ranged to 16 ppm in Trench  1,  44 ppm in       :
Trench 2 and 43 ppm in Trench 3.   Trenches 3,  4  and 5 showed no       '
signs of discolored soil.

Based on the 1974 aerial photograph and the  results of trenching
and boring activities  in  and around  the impoundment area,  the
potentially contaminated area  is estimated to be bounded laterally
within an area  of approximately 9600  square feet (see Figure #12).
The vertical extent of the potential contamination  was  found to
range from 3 to 8  feet.

Table #7 shows that the three trench "source" samples  have residual
contaminants that  include  three   organics  (2-methylnaphthalene,
phenanthrene and total xylenes) and four inorganics (lead, mercury,
sodium and zinc)  reported  above background values for all source
samples.   Lead, mercury and zinc were reported above background
values  for  all  source  samples.    The  vertical  extent  of
contamination in these  three  former  impoundments  was  bounded  by
deeper  soil  samples  that  generally  have reported  values below
background and source sample concentrations.

The above  sampling  results for this area were based  on  samples
collected  by  Dow/DSI.   During this sampling  effort,  EPA  also
collected samples  from the trenched  former impoundments.   Almost
exclusively, all  results  from  EPA's  sampling contained  higher
results than those  reported above.    In addition,  EPA identified
numerous   Tentatively    Identified   Compounds    (TICs)    with
concentrations as  high as  762,300  ppb.   Due  to the  disparate
sampling results,  it has been  determined that a full and accurate
characterization  of the  contamination in  this area  has not been
completed.
                               33

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Composite samples  collected  from Trenches 4,  5, and  6  show that
subsurface  samples from  these  areas  do  not exceed  background
concentrations for any residual contaminant.


Ground Water

A total of twelve onsite ground water monitoring wells were sampled
as part of the RI (Figure #17).  There were five existing wells (D-
1,2,3,4,5),  three new wells installed by Dow/DSI in 1990 (D-6,7,8),
and four  new wells installed  by EPA  in  1991 as  part of  the RI
activities for the  GCVS site (G-20,21,22, 23).  Monitoring well D-8
was placed  in the  lower  portion of the site and was  used  as the
background well.

The statistical  analysis of onsite and background ground water data
did not identify  any  residual  contaminants.   However,  certain
samples were found  to contain parameters above maximum contaminant
levels for drinking water  (MCLs).  Table #8 shows that 3 inorganics
(chromium,    lead,   selenium)    and    two   organics    (bis(2-
ethylhexyl)phthalate, methylene chloride) were reported above MCLs.

The presence of  the organic compound bis(2-ethylhexyl)phthalate is
attributed  to field  contamination.   This compound is  typically
introduced from protective gloves used by sampling personnel.  This
determination is consistent with the analytical data that show that
this  compound was  not detected above  background  concentrations
consistently over multiple sampling episodes.

The presence of  total chromium above background concentrations and
MCLs  was  shown  to be  the result  of  collection and  analysis of
turbid ground water samples.  This was  shown  by the use of a low
disturbance  sampling   methodology employed  to  collect  samples
considered representative of the aquifer.  The  low chromium concen-
trations obtained  using this more representative  sampling  method
are directly  related to  low  total suspended solids  and turbidity
measurements  that  result when  using  a low disturbance  sampling
procedure.

In addition  to total chromium and bis(2-ethylhexyl)phthalate, lead,
selenium, and methylene chloride  were reported to be  above MCLs.
As discussed previously,  the presence of total chromium and bis(2-
ethylhexyl)  phthalate are attributable to  turbid samples and field
contamination, respectively.  All detections of methylene chloride
have associated  contamination of the laboratory sample blanks.  All
lead and selenium  data (with the exception of lead  in background
well  D-8)  were generated  from only one  sampling episode  (four
samples out of a total  of sixteen)  conducted by EPA as part of the
GCVS   investigation.      These   data   were   estimated  at   low
concentrations and  also had laboratory quality assurance qualifiers
attached  to  the  data  due  to  control  limit problems  with  the
analysis of associated matrix spike samples.  Therefore,  the

                                34

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3-6-92
               MGM28796.DO
Figure #17
  0         300'

 APPROX. SCALE
      APPROXIMATE
      SITE BOUNDARY
                                                           NORTHERN SITE FENCE
              PARISH ROAD P-7-31
                                               NOTE: LOCA TIONS ARE APPROX1MA 7E
                                                             LEGEND
                                                       •  - WELL LOCATION
                                              MONITORING WELL LOCATIONS
                                   D.L.1 MUD, INC.. SITE, Abbeville,  Louisiana
                                             £»••;?,', KIHt

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presenceof lead,  selenium and methylene chloride above MCLs is not
considered to be indicative of ground water contamination.


Surface Water and Sediment

Surface water and sediment  sampling  activities  were conducted to
evaluate potential impacts of the site on surface water quality and
sediment characteristics. Both onsite and background samples were
collected to assess  these impacts.   Onsite  surface water samples
were collected during or soon after rainfalls in December 1990 and
January 1991. During the RI, onsite surface water was present only
after heavy rains.

Nine surface  water and  nine  sediment  samples were  collected in
December, 1990  at  the general locations shown on  Figures #5 and
#18.   Four of  these sample pairs  (SW/SD-1,  2,  3,  and  4}  were
initially  considered background  samples.   However,  the use  of
sample location SW/SD-2 was later changed from background to onsite
due to the proximity of the GCVS site to this  location.

Five onsite  surface water  samples  (SW-5,  6,  7,  8, and  9)  were
resampled in January 1991.  An additional  onsite  sediment sample
(SD-6A) was  collected during this period.   In April 1991,  four
additional background sediment samples were collected (SD-10, 11,
12 and 13).

The background locations were coordinated with the local Agricul-
tural Stabilization and Conservation Service (ASCS) representative
to locate areas with similar  soil types and land  uses.   Samples
SW/SD-l  and  SW/SD-2 were  collected from  abandoned  irrigation
canals.   Background  sample  pairs (SW/SD-3 and  4)  and  background
sediment  samples  (SD-10, 11,  12  and 13) were  collected from  a
nearby drainage ditch located upstream of surface  runoff from the
site.

Sample  pairs SW/SD-5  and  7  were collected  from  the  abandoned
irrigation canal that crosses the D.L.  Mud site.  Sediment sample
SD-6A was also collected from this abandoned canal.  The impact of
the GCVS  discharge  on existing site drainage was  evaluated with
sample pairs  SW/SD-6 and SW/SD-8 which are located upstream and
downstream,  respectively,  of  the GCVS discharge.   Sample  pair
SW/SD-9 was collected from the abandoned  irrigation canal southeast
of the former facility process area.

During  the  ninth  sampling event,  EPA's  oversight  contractor
identified  a  drum in  the  onsite  canal.   Figure  #18  shows the
location  of  the drum.   In  March,  1992, one sediment sample was
collected  from  the  drum.    This  sample  was  collected  only  to
characterize  a  potential  waste  for  disposal.   Therefore,  EPA
Contract Lab Program protocol was not utilized and no duplicates,
spikes or equipment rinsate  samples were collected.  The contents

                                36

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                                 Figure #18
PARISH ROAD P-7-31
                                                       GULF COAST
                                                     VACUUM SERVICE
      SW/SD1
      =^l


20' CANAL
                                                        NORTHERN SITE FENCE.

                                               DRUM LOCA TION
                       D.L  MUD,
                       INC.,  SITE
                                            APPROXIMA TE
                                            SITE BOUNDARY
                                     /S77E SURFACE WA TER/ SEDIMENT SAMPLES
                                        D.L. MUD, INC., SITE. Abbeville, Louisiana

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of the  drum  were found to be non-hazardous.   The drum was later
disposed-of as a non-hazardous solid waste.

Surface  water  sampling results  indicate that calcium  in onsite
surface water was  determined  to  be the lone residual contaminant
(significantly above background  values),  while barium,  lead,  and
bis(2-ethylhexyl)phthalate  were  reported  above  MCLs.    Seven
inorganics  (arsenic,  chromium,  copper, lead,  nickel,  silver  and
zinc) were reported at concentrations above federal ambient water
quality  criteria (AWQC).   Table  #9 presents a  summary of these
onsite surface water results.  The organic compound bis(2-ethylh-
exyl)phthalate is a common sampling and laboratory contaminant and
was not used at the site during its operational history.  The three
samples noted to contain  this compound were also noted as having
data  qualifiers  since  this  compound  was  also  detected  in  the
laboratory blank and the laboratory had  instrument calibration
problems during  analysis of these samples.

Both barium and  lead were detected above MCLs on one occasion at
each of two locations (SW-6 and SW-8).   Concentrations reported at
SW-8 are greater than those reported at SW-6.  Resampling showed
both compounds at both locations  to be  below MCLs.  Both locations
that were affected are  located in a drainage swale downstream of
the former facility process area, with SW-8 located downstream of
SW-6.   The presence of calcium  above background values  is more
widespread and  tends to  repeat  for sequential  sampling events.
Acute freshwater AWQC for copper  and  zinc were  exceeded  at  all
onsite  sample locations except  SW-2 and by the  maximum measured
background concentration.   Acute AWQC for lead was exceeded only at
SW-8; while the AWQC for silver was exceeded at SW-5, SW-8 and SW-
9.  Chronic freshwater AWQC for copper and zinc were exceeded for
all onsite locations except SW-2  and by background.  All locations
and background exceeded the chronic AWQC standards for lead.

Comparison of onsite data to  background and MCL values indicates
that there may be some residual inorganic impact on surface waters
originating in the  former  process area and that the GCVS discharge,
located upstream of the SW-8 location, may also have contributed to
this contamination.  Exceedances of AWQC standards are more wide-
spread,  but in general, similar impacts are shown by the acute AWQC
standards.  Chronic AWQC  exceedances are typical for all (onsite
and background)  values.

Table #10  shows that  analytical  results  for sediment residual
contaminants are similar  to those presented  earlier for surface
water.  Residual contamination appears limited to inorganics; no
organics were  noted above  background.   No  concentrations above
background were noted for sample SD-7 for any analyte.

The extent of residual contamination at SD-5 and SD-6A is limited
because of their  location  within diked areas.  Results for SD-6 and
SD-8 may reflect the  impacts  of  previous facility operations, or

                               38

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the  impact  of the GCVS site discharge,  since  these samples were
collected from a drainage pathway downstream of  the former location"
of storage  and blending tanks and the  GCVS discharge is located       I
upstream of location SD-8.  Concentrations of residual contaminants       I
are higher at  SD-8 than at the upstream location SD-6.  The value
reported  at  SD-9  for  copper  is  marginally  above  the  maximum       i
background value of  22.6 mg/kg.                                         j

EXPOSURE ROUTES

The potential migration routes of residual contamination are ground       '
water,  surface water, and  air.   Airborne contaminants  are not
expected to be of concern for  this site because of  the nature of
residual contaminants  and the  relatively low concentrations.  In
addition, the site cover,  lack  of disturbance, and relatively high
moisture of  the area help  to  minimize soil disturbance  and the
creation of aerosols.

The  potential  for  migration of  contaminants   from  the  site  is
affected by two important hydrogeologic factors:

     •    The  site soils are generally  very low in  permeability,
          and  have medium values of  organic content and cationic
          exchange capacity.

     •    The general ground water  flow  direction is to the north,
          with a low  gradient and localized mounding resulting from
          large impoundments on the GCVS site.

Although the ground water pathway is considered to be a potential
route of contaminant  migration (such a situation already apparently
exists at the adjacent GCVS Superfund Site), the low permeability
of the soils tends to minimize vertical migration of contaminants
from surface soil, subsurface  soils,  sediment,  and  surface water
into the underlying ground water.  These soils typically extend to
depths of 30  feet,  although a lens of  silty sand was identified
along  the  D.L.  Mud  and  GCVS  site  property line  at depths  of
approximately  20 feet  below ground surface.   Since  the greatest
soil depth noted to contain residual contaminants is  approximately
ten  feet,  a minimum of  ten feet  of native soil  is  present  to
mitigate contaminant transport  to  ground water.  The relatively
insoluble nature of the main residual contaminant in  surface soils
(barium sulfate) minimizes its potential  for transport while the
soil characteristics (medium cation exchange capacity and organic
contents) tend to induce adsorption of other residual  contaminants,
thereby  further  retarding  migration   potential.    It  is  more
difficult to predict the potential for  migration  of contaminants
identified in the former impoundment areas because  the types and
concentrations  of   these  contaminants   has   not    been   fully
characterized.
                               39

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Since the ground water flow is northerly, contaminants, if intro-
duced into  the aquifer,  could be transported  in  that direction.
With a relatively low potentiometric gradient and flow rate of only
22 feet  per year,  site contaminants would take over one hundred
years to reach  the  closest receptor,  since the  nearest  active
ground water well north of the  D.L. Mud site is approximately one-
half mile  away.   In that period of time, contaminants  could be
expected to be diluted by ground water dispersion, adsorbed to soil
structure, or degraded by physicochemical or biological activity to
a large extent.  Both the D.L. Mud RI report and the GCVS RI report
(EPA, 1992) show ground water mounding beneath the GCVS site that
results in ground water flow from the GCVS impoundments toward the
D.L. Mud site.   This  mounding  further  retards the  movement of
ground water from the D.L. Mud property to potential receptors.

The  surface water pathway is  also  considered to  be  a potential
route of contaminant migration.  Site surface water runoff is to
localized ditches,  which is indicated  by the presence  of site-
related contaminants in sediments in these ditches.  However, the
ditches  are contained  by levees that limit  lateral migration of
water and sediment borne  contaminants.   In addition,  the evapot-
ranspiration rate approximates  rainfall,  which prevents buildup of
surface water, as evidenced  by intermittent  water  in the ditches
during  the  RI.    Further,  the residual contaminant  and  soil
characteristics described above  (insoluble nature,  low permeabil-
ity, medium cation  exchange capacity  and  total   organic  carbon
values and soil depth) assist in impeding the vertical migration of
potential contaminants  from the sediments  and surface  water to
ground water.

Under current site conditions,  there are no people who  live or work
onsite.  Therefore,  a trespasser is the most representative of the
population  most  likely  to  be  exposed  onsite   under  current
conditions.   Potential  exposure would  be  from direct  contact,
ingestion,  and inhalation of site contaminants.

Future land use  assumptions are based on two important factors.
First,  because the site is presently an abandoned light-industrial
use  facility,  with  no  human inhabitants and  located  next  to the
GCVS Superfund Site,  it seems reasonable that this type of land use
will continue.   Second,  because there are currently  no  land use
restrictions  affecting  this property  and residential areas are
located nearby, it is possible that the property could be used as
a residential location in the future.
VI.  SUMMARY OF SITE RISKS

A  baseline risk assessment  (BRA)  was  conducted to  analyze  the
potential  adverse  health  effects  (both  current  and  future)
resulting  from human exposure  to hazardous  substances in surface
soil, subsurface soils, sediment, ground water and surface water at

                                40

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the D.L. Mud  site.   The BRA provides the basis for taking action
and indicates  the exposure pathways that need to be addressed by
the remedial  action.   It  serves  as the baseline indicating what       J
risks  could exist  if no  action  were taken  at  the site.   This       '
section  of  the ROD reports the results  of  the BRA conducted for
this site.                                                              (

By definition, a BRA evaluates risk under the no-action alternative
(that  is,  in the absence  of  any remedial  actions  to  control or       ,
mitigate  releases  or exposures).   The  BRA  for  this  site was       J
prepared utilizing data from  the RI.   The methods used  in the       '
development  of  the  risk  assessment  are  based  on general EPA
guidance  (Office  of  Emergency  and  Remedial Response.    Risk       J
Assessment Guidance for Superfund.  Vol.  I.  Human Health Evalua-       J
tion Manual (Part A).  1989. also known as "RAGS"), the NCP, and in
accordance with site-specific guidance developed  by  Region VI.  In       i
addition,  an  environmental  risk  assessment was  conducted  to       j
evaluate risks to environmental  species.  These reports  can be
found  in the Administrative Record.

CHEMICALS OF POTENTIAL CONCERN

The nature and extent of inorganic and organic chemical constitu-
ents (lOCs) identified in the site media  are discussed in Section
V. of  this ROD.   Chemicals detected  in low  frequency  were not
considered  to be representative  of  the nature  and  extent  of
residual contamination at the site.  However, all lOCs identified
in the site media were used to assess total  site  risk.   Factors
such as frequency of  detection as well as nutritional benefit and
comparisons  with background  concentrations  were   not  initially
considered when developing the list of chemicals of concern (COCs)
for use  in  the  BRA.   The influence  of  these  factors on the
assessment  of  total  site  risk is  discussed in the  uncertainty
section.  Since risks  associated with identified TICs are difficult
to evaluate, they are not included in the quantitative assessment
of total site risk.   However,  a qualitative  discussion  of  TICs
identified  at  the D.L.  Mud  site  is  presented   below  in  the
uncertainty subsection.

Table  #11 presents  the  descriptive statistics (e.g., minimum and
maximum detected value, mean estimation, upper confidence limit) of
the lOCs detected  on the  site  and  in  the  background for the
following media:

          Onsite ground water
          Onsite surface water
          Onsite surface soil
          Onsite sediment
          Onsite subsurface soil  (non-"source" areas)
          Onsite source area near Well G-22 (subsurface soil)
          Onsite source area near Well G-23 (subsurface soil)
          Onsite source area near boring SB-30 (subsurface soil)

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        .. Onsite impoundment area (subsurface soil)
          Background ground water
          Background surface water
          Background surface soil
          Background sediment

An exposure point concentration (used for risk calculations) is the
arithmetic mean concentration of a chemical in a medium, averaged
over the area in which exposure is expected to occur.  Because of
the uncertainty associated with the exposure point concentrations,
the upper 95th confidence limit of the arithmetic mean (UCL95) is
generally  used to  provide a  degree  of conservatism.   If  the
calculated value of the UCL95 exceeded the  maximum value used to
calculate the UCL95 at an  exposure point, then the maximum value
(rather than the UCL95) was used.   Chemicals which were analyzed
for but not detected in a  sample at a level higher than the normal
detection  limit  were labeled as  "undetected".   For  purposes of
calculating  exposure point  concentrations,  if a chemical  was
detected at least once in  a medium, the chemical was assumed to be
present  in all  samples  of  that  medium,   and non-detects  were
evaluated using one-half the "undetected" value.

EXPOSURE SCENARIOS EVALUATED

The D.L. Mud site exposure assessment (and subsequent baseline risk
assessment) is based  on  the assumption  that  no further response
actions  are  performed at the  site   and  on  the  conservative
assumption that unrestricted use of the site and its resources by
adults and children is permitted.  A potential current use exposure
involving  a  trespasser   is  evaluated.    Future  use  scenarios
involving residential (includes agricultural use) and occupational
use of the site are evaluated.

The D.L. Mud site is located in a rural area.   Surrounding land use
is generally agricultural, although residences are located within
one mile of the site.  It is estimated that up to 116 people live
within the one mile study area surrounding the site.  No threatened
or endangered species have been reported in the study area.

Exposure  pathway evaluations  were made on  the  basis of  site
history,  analytical results of the onsite and background samples,
and exposure  setting.   These evaluations are presented in  Table
#12.   Ground water, surface water,  surface  soil,  sediment,  and
subsurface soil are considered the five potential secondary sources
of exposure to residual contaminants.  Subsurface soil is evaluated
based  on  division  into   five  areas   of  assessment:   (a)   four
subsurface  soil  "source  areas"  which  are  areas  of  visible
contamination and/or positive organic  vapor readings (1. located
near Well G-22; 2.  located near Well G-23;  3. located near boring
SB-30; 4.  located  in the  former impoundment  area)  and (b)  other
subsurface  soil  samples without source  area  characteristics.   A
tertiary source of  exposure to residual contaminants considered is

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agricultural products  (root  and  leafy vegetables,  beef, and milk       '
potentially contaminated by ground water and soil).

The routes of exposure considered are ingestion, dermal absorption,       I
and  inhalation.   Under  the  current  use scenario,  incidental
ingestion  of  surface  soil  and  sediment by  a  trespasser  is       r
evaluated.  Dermal absorption of contaminants from surface water,       j
surface  soil,  and sediment  by  the  trespasser receptor  is also
quantitatively assessed.

Ingestion of ground water, surface soil, sediment,  and subsurface       '
soil  is  quantitatively  assessed  for  the  residential  adult,
residential child, and occupational adult receptors.  Ingestion of       I
agricultural  food products  is  quantitatively  assessed  for  the       j
residential receptor.  Incidental ingestion of surface water  is not
considered because it  was assumed that surface  water conditions       ,
(mainly lack of water depth)  preclude  swimming.  Dermal absorption       j
of contaminants  from ground water, surface water,  surface  soil,       '
sediment, and subsurface soil by the residential and occupational
receptors is also quantitatively assessed.                               {

The magnitude of  human  exposures to  the contaminants at the D.L.
Mud site  is  described as the  potential dose or intakes  by each
receptor.  In general, standard exposure factors,  as defined  in the
Human Health  Evaluation Manual.  Supplemental  Guidance;  Standard
Default Exposure Factors fOSWER Directive 9285.6-03).  were used for
this determination.   In addition, variability  among individuals
usually leads to  a wide distribution of intake values.   In most
cases,  input variables  in the risk equation  were chosen so that the
resulting intake is about  equal to  the 95th percentile of the dose
distribution curve.   This  is  referred  to as the Reasonable Maximum
Exposure (RME).   For  future residential populations, the variables
were also chosen  to  estimate the average  (AVG)  intake  (about the
50th percentile of the  distribution).  This approach, commonly re-
ferred to  as  the  "central  tendency", provides  a  range  of risk
estimates, AVG to RME,  for future residential exposures.

A central tendency exposure  (CTE) is required for risk assessments
and was to be included in the assessment  of the hypothetical future
residential child. However, using Region 6 exposure variables, the
CTE and RME would  be  identical for soil ingestion  by a child.  Both
the RME  and CTE are  the  same  for  a child because  both exposure
assessments utilize a soil ingestion  rate  of  200 mg/day due to a
lack of information indicating more appropriate values.

TOXICITY ASSESSMENT

The purpose  of the  toxicity assessment was  to weigh  available
evidence regarding the  potential  for contaminants to cause adverse
effects in exposed individuals.  The toxicity assessment involved
two steps: hazard identification and dose-response assessment.  The
hazard  identification  determined whether  exposure  to a  chemical

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could cause an  increase  in the incidence of a particular adverse
health effect  (carcinogenic or noncarcinogenic)   and whether an
adverse health  effect would likely occur in  humans.   The second
step,  dose-response  assessment,  quantitatively  evaluated  the
toxicity information and  characterized the relationship between the
dose of the chemical received and the incidence of adverse health
effects in the exposed population.

Toxicity  values (i.e..  reference  doses for  non-carcinogens and
slope factors for carcinogens) are used in the risk characteriza-
tion to estimate the likelihood of adverse  effects  occurring in
humans at different  exposure  levels  and are specific to exposure
routes.  The EPA has established a weight-of-evidence classifica-
tion system for carcinogens as follows:

*    Group A - Human carcinogen
*    Group Bl or B2 - Probable human carcinogen; Bl indicates that
     limited  data  are  available and B2  indicates  sufficient
     evidence in animals and inadequate or no evidence in humans
*    Group C - Possible human carcinogen
*    Group D - Not classifiable as to human carcinogenicity
*    Group E - Evidence of noncarcinogenicity for humans

Slope factors  ("SFs")  have been developed  by EPA's  Carcinogenic
Assessment  Group  for estimating  excess  lifetime cancer  risks
associated with exposure to potentially carcinogenic contaminant (s)
of concern.  SFs, which are expressed in units  of (mg/kg-day)"', are
multiplied by the  estimated intake of a potential carcinogen,  in
mg/kg-day,  to  provide  an upper-bound  estimate  of  the  excess
lifetime cancer risk associated with exposure at that intake level.
The term "upper bound", reflects the conservative estimate of the
risks  calculated  from  the SF.    Use  of  this  approach  makes
underestimation of the actual cancer risk highly unlikely.  SFs are
derived  from  the  results  of human  epidemiological studies  or
chronic animal bioassays  to which animal-to-human extrapolation and
uncertainty factors have  been applied  (e.g. . to account for the use
of animal data to predict effects on humans).

Reference doses ("RfDs")  have  been developed by  EPA for indicating
the  potential  for  adverse  health  effects  from  exposure  to
contaminant(s)  of  concern exhibiting noncarcinogenic  effects.
RfDs, which are expressed in units of mg/kg-day, are estimates of
lifetime  daily  exposure  levels  for  humans,  including  sensitive
individuals.  Estimated  intakes of contaminant(s) of concern from
environmental  media  (e.g..  the  amount of  a  contaminant(s)  of
concern ingested from contaminated drinking water) can be compared
to the RfD.  RfDs are derived from human epidemiological studies or
animal  studies to  which uncertainty  factors have  been  applied
(e.g. . to account for the use  of  animal data to predict effects on
humans).
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Of  the-residual  contaminants  identified in one  or more samples        '
collected from the D.L. Mud site, eleven are considered carcinogens
when  exposed orally  and twelve are  considered carcinogens when        j
exposed  through   inhalation.    Table   #13  lists  the  chemical        |
carcinogens  for  the  oral and  inhalation  exposure routes and
provides their weight-of-evidence classification.                        i

Noncarcinogenic health effects include a variety of toxic effects
on  body systems  ranging  from  renal  toxicity (toxicity  to the
kidney)  to  central nervous  system disorders.   Noncarcinogenic        I
health effects fall into two basic categories:   acute  toxicity and        '
subchronic and  chronic toxicity.   Acute toxicity  occurs after a
single exposure  (usually at high doses) ,  and  the  effect is seen        I
immediately.   Chronic toxicity occurs  after  repeated exposure        ]
(usually at  low doses), and  the effect is seen weeks, months, or
years after  the initial exposure.

Chemicals causing  noncarcinogenic effects  (e.g., systemic toxins)
also exhibit levels of exposure that can  be tolerated  by organisms
without causing an observed health effect.   It is believed that
organisms have adaptive mechanisms  that  must be overcome before a
toxic effect is manifested.   Table #14 provides a summary of the
characteristic  noncarcinogenic effects  and lists  available RfD
values and confidence  categories for all verified RfDs for all of
the chemicals of concern at the D.L. Mud site.

RISK CHARACTERIZATION

Human Health Risk

The risk  of  cancer from exposure  to a  chemical is described in
terms of the probability that an individual exposed  for his or her
lifetime will develop cancer.   Typically,  cancer risks  of IxlO"6
(one in a million)  or  lower are considered to be so small that they
are of  no  practical concern.   Higher cancer risk  levels  may be
cause for concern, and EPA typically requires site remediation if
risks exceed IxlO"4.

Evaluation of noncarcinogenic risk  is accomplished by comparing a
calculated intake with an acceptable intake for each chemical and
for each pathway that contributes to a population's exposure.  The
ratio of  the calculated  intake  versus the acceptable  intake is
termed the Hazard Index (HI).   The HI  is calculated  by  adding
chemical-specific  Hazard Quotients  (HQs).   An HI of  1.0  or more
shows an intake greater than the acceptable level and indicates the
need for remedial action.

The likely effect  of exposures to lead contamination was estimated
using EPA's Uptake/Biokinetic model (UBK).   The UBK model predicts
mean blood levels associated with multimedia exposure levels that
are defined as site-specifically as possible. A significant amount
of  information  is present  in  the scientific  literature  that

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provides  evidence  of exposure-effect relationships  extending to
blood  levels  of 10  to  15 Mg/dL  in infants and  young children.
Using  10  M9/dL  as  a cutoff value, EPA has  determined  that it is
desirable  to have no  more than five  percent  of  the  exposed
population exceeding this level of concern.  The UBK model used to
assess risk from lead is restricted to the evaluation  of a child in
a  residential  setting,   since a child  is  significantly  more
sensitive to the toxic effects of lead than an adult.

The following discussions summarize potential site  risks by medium.
Table #15 presents the carcinogenic risks and lists the chemicals
primarily  responsible  for  the risks for onsite  and  background
exposures.  Tables  #16 presents potential noncarcinogenic health
hazards  and  lists  the  chemicals  (and  their  HQs)   primarily
responsible for the His.

Risks from Surface  Soil -  Health  risks related  to direct contact
(or dermal absorption)  of contaminants from surface soil adhering
to exposed body  surfaces were assessed. The  excess lifetime cancer
risks for onsite and background dermal exposures  are similar for
all receptors evaluated.   The His  for onsite and background dermal
exposures are less than 1.0 for all receptors.

Incidental ingestion of surface soil was assessed for residential
adults and children based  on soil ingestion rates of 0.1 and 0.2
grams per day, respectively, and for a trespasser and occupational
adults based  on a  rate  of 0.05 grams per day.   The  conservative
assumption is made in assessing total site risk that soil residual
contaminants ingested by the human  receptors are  absorbed by the
body with  the same efficiency as chemicals dissolved  in aqueous
solution.  The excess lifetime cancer risks related to incidental
ingestion of  surface soil are similar for  onsite and  background
exposures  for all  receptors  evaluated.   The  HI estimated  for
incidental  ingestion  of   surface  soil  exceeds 1.0  for  the
residential child  (3.8) and adult (4.2)  onsite  exposures.   These
His are dominated by the barium HQ calculated for the residential
child  exposure.   The HI  for  incidental  ingestion of  soil by  a
trespasser and an occupational laborer is less than 1.0.

Risks from Subsurface Soils -  Subsurface soil was evaluated based
on division  of  the  site  into five areas for assessment:   four
subsurface soil  contaminant "source areas" ("source area 1" or G-22
samples, "source area 2"  or G-23 samples,  "source  area  3" or SB-30
samples, and "source area 4" or former impoundment area samples),
which are areas  of  visible contamination  and/or positive organic
vapor readings  (Figure #7)  and all other subsurface soil (those
samples without source  area characteristics).   Risks from sub-
surface source areas were based on the ratio of the source area to
a typical rural residential lot size in  the general area of  the
Site, such as the small subdivision located southeast of the D.L.
Mud Site.  Lots in this subdivision are approximately one acre in
size.  Therefore, an acre weighted risk (AWR) method is employed to

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characterize risk  associated  with exposures to the source areas.
Risk is weighted according to  square footage of the source area and
its area percentage to a typical one acre residential plot in the
area of the Site.

The AWR cancer  risks for incidental ingestion and dermal absorption
of contaminants ranged from 3xlO"5 to 3xlO"6 for all the source areas
for all three receptors evaluated.  Cancer risks in subsurface soil
source areas 1 through 4 exist primarily because of low levels of
arsenic and beryllium. Cancer risks  for incidental ingestion and
dermal  absorption  of  contaminants  in nonsource  area  subsurface
soils range from 3xlO"5 to 3xlO"6 for all three receptors evaluated.

Non-cancer His for incidental ingestion and dermal absorption of
contaminants from nonsource area subsurface  soil are less than 1.0
for  all three  receptors  evaluated.    The  non-cancer AWRs  for
incidental ingestion and dermal absorption of contaminants by the
residential child and the occupational adult are less than 1.0 for
all source areas.  For the residential adult, the non-cancer AWRs
for incidental ingestion and dermal absorption of contaminants are
less than  1.0  for  source areas 1, 2, and 3;  however,  for source
area  4  the  non-cancer  AWR  is  equal to  1.0  for an  ingestion
exposure. In this instance, the residential  adult's non-cancer AWR
is primarily due to 6-year ingestion exposure to barium during the
adult's childhood,  which results in an HQ of 0.9.

It  should  be  noted   that  the  risk  calculation  for  the  former
impoundment  area  (source  area  4)  was  calculated  using  data
collected by Dow/DSI  during  the  RI.   As mentioned earlier,  EPA
split data  from this area differed significantly and it is expected
that the use of this data would result in higher overall potential
risk than calculated.   In addition, the fact  that no specific risks
were quantified  in any of the  obviously  contaminated  subsurface
areas related  to the  former  impoundment  areas or near  SB-30  is
further questioned due mainly to the lack of specific  information
regarding the nature and concentration of individual contaminants
that are present.  For example, the TICs identified in these areas
are reportedly high molecular weight  aliphatic hydrocarbons that
may be associated  with crude  oil,  but individual  compounds could
not be identified with the routine chemical  analysis methods that
were used during the  remedial investigation.   The TIC  concentra-
tions of most concern are located in the area associated with the
former impoundments.  The number, concentration,  and depth of these
hydrocarbons pose a greater potential risk to the ground water than
those found near SB-30.

Risks from  Ground Water - Excess lifetime cancer risks  from ground
water ingestion and dermal  absorption were the same for onsite and
background  exposures  for the  adult  residential receptors.   The
cancer risks for ground water ingestion and dermal absorption  by
the residential  child onsite  are  equal  to  the background  risk.
Excess lifetime cancer  risks from ground water ingestion and dermal

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absorption were the  same  for  onsite  and background exposures for
the adult occupational receptors.  In all  ground water ingestion
scenarios,  both  onsite and  background, the  cancer  risk exists
because of low levels of arsenic.

The HI exceed 1.0  for onsite and background ground water ingestion
exposures for  all receptors evaluated  (residential  adult,  resi-
dential  child, occupational  laborer).    The HQs  of  antimony,
arsenic, and thallium are the major contributors to the HI  for both
onsite and background ground water ingestion by a residential adult
and to the HI for both onsite and background ground water ingestion
by an occupational adult.   The HQ of antimony, arsenic, manganese,
thallium, and barium are the major  contributors to the HI  for both
onsite  and  background ground water  ingestion by a  residential
child.  The noncarcinogenic HI is significantly less than 1.0 for
onsite and background exposures related to dermal absorption from
ground water for all receptors evaluated.

Risks from Sediments - Health risks related to  dermal absorption of
contaminants from sediment adhering to exposed body surfaces were
assessed.   Excess lifetime cancer risks are  less  than  10"6 for
onsite and background exposures for all receptors evaluated.  The
noncarcinogenic hazard index is significantly less than 1.0 for all
dermal absorption of contaminants in sediment scenarios.

Incidental  ingestion  of   sediment  is  assessed   for  adults  and
children based on soil ingestion rates of 0.1 and 0.2  grams per
day, and for a trespasser and occupational adults based on a rate
of 0.05 grams/day.  Excess lifetime cancer risks are less than 10"6
for onsite and background exposures for all receptors evaluated.
The noncarcinogenic hazard index is significantly  less  than 1.0 for
all  incidental ingestion  of  residual  contaminants   in  sediment
scenarios.

Cumulative  Carcinogenic  And Noncarcinoqenic  Risks  - The excess
lifetime cancer risks and hazard indices are summed across pathways
to provide  an  estimate of  total  carcinogenic and noncarcinogenic
risks  at  the site based  on  current  trespasser  exposures (Table
#17) ,  future  residential  exposures  (Table #18)   and  future
occupational exposures (Table #19). When totaling the residential
and  occupational  scenarios,  the greatest  subsurface soil  risk
values were  chosen from among the  source and  nonsource areas for
the summation.

The cumulative cancer risk for trespasser exposures onsite  is equal
to  the cumulative cancer  risk  from  background  exposures.   The
cumulative HI for  occupational laborer exposures onsite is  equal to
the cumulative HI  for background  exposures.  The cumulative cancer
risk  for residential  adult  exposures  onsite  is equal  to  the
cumulative cancer risk from background exposures.
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The cumulative HI for residential adult exposures onsite is greater-
than the cumulative  HI for background exposures.  Both onsite and
offsite cumulative His are dominated by potential risks associated
with the ingestion of  ground water and  surface soil.   The onsite
ground  water  risk   was  associated  with  a  single detection  of
antimony and the surface soil risk is associated with the presence
of residual barium.

Cumulative cancer risk for the child receptor is the same onsite as
for  background  exposures,  at an estimate  of 10'4.    The  child
receptor's cumulative HI exceeds the background cumulative HI.  The
cumulative  HI  estimated for the  onsite exposures  potentially
incurred by a  child receptor is  dominated  by the ground  water
ingestion exposure route (due to the single antimony detection) and
is influenced  to a lesser extent  by the  incidental  ingestion of
surface  soil  exposure  route  (due  to  elevated residual  barium
concentrations).

The cumulative cancer  risk for occupational  exposures onsite is
equal to the cumulative cancer risk from background  exposures.  The
cumulative HI for occupational laborer exposures onsite is greater
than the cumulative HI for background exposures.  Both cumulative
His are dominated by ingestion of ground water (due to the single
antimony detection).

Uncertainties Associated With The Human Health Risk Calculation

There are a number of stages  in the risk assessment process where
precise evaluations are not possible. These include uncertainties
regarding the  true  concentrations of chemicals  in environmental
media, the amount of  contaminants taken in by  humans and the likely
health consequences of the resulting exposure.  Risk assessment as
a  scientific activity  is subject  to  general  and site-specific
uncertainty.  General uncertainty is related to the discipline of
risk assessment.  Site-specific uncertainty is  related to the area
being  assessed.    Table  #20 lists general  and  site-specific
uncertainties, respectively,  for D.L. Mud site risk assessment.

This assessment  was  also subject  to uncertainties  related  to the
following items:

          TICs
          Identification of substances used to assess risk.
          Toxicological assessment
          Bioavailability
          Exposure estimation
          Risk characterization

Split sampling results from the former impoundment  area indicated
the presence of a large concentration of TICs.   The majority of the
TICs are substituted benzenes and  naphthalenes which are generally
eye and skin irritants.   Because the  identities and concentrations

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of  the TICs  are  uncertain and  the  fact that  they do  not have
associated  toxicity factors  (such  as  slope  factors  and RfDs),
inclusion of these compounds in the quantitative  risk assessment is
not possible.

Other specific uncertainties that have significantly impacted the
D.L. Mud risk assessment  center  on the  use  of the subchronic RfD
for barium.  Scientific debate continues regarding the merit of the
existing subchronic RfD.   For the purposes of this risk assessment,
it has been decided to use the existing value in HEAST until such
time  that  a  final determination is rendered  on the  use  of  a
different value if appropriate.

As noted in  Table #20, some of these limitations may  lead to an
underestimate of  risk, some are  more likely to  overestimate than
underestimate risk and some introduce uncertainty that may either
overestimate or underestimate risk. Consequently, the quantitative
risk  estimates  derived  for  this   site  should  be  considered
approximate, with a significant range of uncertainty and should be
considered in risk management decisions.


Environmental Assessment

The ecological assessment was  limited because of existing land use
patterns   and because  the  Environmental  Assessment   at  the
neighboring GCVS  site estimated a minimal impact  on the environment
while possessing significantly worse contamination problems.

The site  is  coastal prairie with some  mixed hardwoods  near the
canals.  It is considered "prior converted cropland" and is not a
jurisdictional wetland.  The site is  industrial, and the surround-
ing area is a mixture of residential, agricultural, and industrial
development.  Aquatic  and terrestrial organisms would  experience
minimal exposure,  because they avoid highly developed  areas and
because more suitable habitat is abundant nearby.

No listed  or  proposed  threatened or  endangered  species have been
found within one  mile of  the site.  Aquatic and terrestrial organ-
isms could be affected  by direct  contact with or ingestion of soil
and sediment  in isolated  areas.  There  could  be impacts to biota
exposed to site surface water.  However,  the  impacts would probably
be minimal because site surface waters are intermittent and would
produce limited exposures.

Risk Assessment Summary

The  results  of   the  Risk  Assessment  indicate that  actual  or
threatened releases of  hazardous substances from  the D.L. Mud Site,
if not addressed by the preferred alternative or one of the other
active measures  considered,  may present  a  current or  potential
threat  to  public  health, welfare,   or  the  environment.   These

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threats  are  identified as the calculated noncarcinogenic risk to
future residents from total barium in surface soils and to unknown
risks  potentially  associated  with  the  visually  contaminated
subsurface soils.

REMEDIAL ACTION OBJECTIVES AND GOALS

CERCLA and the NCP  define remedial action objectives (RAOs) that
are  applicable  to  all  Superfund  sites.    They  relate to the
statutory  requirements  for  development  of  the  remedy.    Site-
specific remediation goals relate to specific contaminated  media
and potential exposure routes and are used to  identify target  areas
of  remediation  and contaminant  concentrations.    Site-specific
remediation goals require an understanding of the contaminants in
their respective media and are based upon the  evaluation of risk to
the public health and  the environment and applicable or relevant
and appropriate requirements  (ARARs).  These  remediation goals are
as  specific  as  possible without  unduly  limiting  the  range  of
alternatives  that  can  be  developed for   detailed  feasibility
evaluation.

The  statutory  scope of  CERCLA was  amended  by  SARA in  1986  to
include:

     •    Refinement of  goals  for the degree  of  remedial action
          cleanup in that remedial actions "shall obtain a degree
          of  cleanup  of hazardous  substances,  pollutants,  and
          contaminants released into the environment and of control
          of further releases at a minimum which assures protection
          of human health and the environment" (Section 121  (d)).

     •    Preference for remedial actions "in which treatment that
          permanently  and   significantly  reduces   the   volume,
          toxicity,   or  mobility  of  the  hazardous  substances,
          pollutants,  and contaminants  is  a  principal  element"
          (Section 121(b)).   The  lead  agency must publish  an
          explanation  if a permanent  solution using  treatment or
          recovery technologies to the maximum extent practicable
          is not selected.

     •    Requirements that  the selected  remedy  comply with  or
          attain the level of any "standard, requirement, criteria,
          or limitation under any Federal environmental law or any
          promulgated   standard,   requirement,    criteria,   or
          limitation under a State environmental or facility citing
          law that  is  more stringent than any Federal  Standard,
          requirement,     criteria,    or    limitation"      (Sec-
          tion 121(d)(2)  (A)) .

In the NCP, 40 C.F.R.  §300.430(a)(1)i, EPA  explicitly defines the
national objective,  management principles, and expectations of the
CERCLA program.   The  national  objective  of  the CERCLA  remedy

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selection process  is  to "select remedies that  are  protective of
human health  and the environment, that maintain  protection over
time, and that minimize untreated waste."

EPA  identified  six general  expectations  to  be considered  in
developing appropriate remedial alternatives in the CERCLA program:

     •    The  use  of treatment  wherever  practicable  to  address
          principal threats.

     •    The use of engineering controls (e.g., containment) for
          waste  that poses  a relatively low  long-term threat or
          where treatment is impracticable.

     •    The use of the appropriate combination of treatment with
          engineering  and   institutional   controls   to  achieve
          protection of human health and the environment.

     •    The  appropriate use  of institutional controls  to sup-
          plement engineering  controls for short-  and long-term
          management to prevent or limit exposures.

     •    The use of innovative  treatment technologies when such
          technologies offer potential for comparable or superior
          performance, lesser adverse effects, or lower cost.

     •    The  return  of ground  water  to usable, beneficial use
          wherever practicable within a reasonable period.  Where
          restoration of ground water is impracticable, prevention
          of further plume migration,  prevention of exposure, and
          further evaluation of risk reduction will be expected.

The studies undertaken  at  the  D.L.  Mud Site  have identified low
level  risks which  require  remedial   actions.    Low  level  risk
materials are sources of contamination  that  could be kept in place
by capping  and pose a low risk.  For  example,  the  surface soils
identified  onsite  with  residual  elevated   levels  of   barium
contamination are considered a low level risk because the associ-
ated risk is  relatively low (less than an  order  of  magnitude in
comparison to  accepted  action  levels)  and because these residual
contaminants could  be kept  in  place with a capping  remedy,  thus
eliminating the potential for migration or ingestion.

In addition, EPA has determined that there is an unknown potential
risk -related to the source materials identified in the subsurface
soils in  the  former impoundment  areas.   This potential  risk is
related to the unknown capacity for these contaminants to migrate
into the  ground  water and the unknown impact these contaminants
would have on the quality of the ground water.

The remedial objective determined to be necessary at the Site is to
preserve  human  health  and  the  environment  by  eliminating  or

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reducing, identified  and/or potential  risks  by  preventing the
ingestion  of  barium-contaminated  soils  and  by  reducing the
potential  for migration  of contaminants  from both  surface and
subsurface soils to the ground water.  Additional specific remedial
objectives determined  to be necessary at the D.L. Mud Site are:

*    Primary:       Preserving the  Site for non-residential uses
                    and reducing  the potential for migration to
                    ground water of site-specific contaminants.

*    Secondary:     Restoring the Site for unrestricted uses.

The risk assessment conducted as part of the RI  showed that future
occupational and trespasser land use scenarios result in acceptable
risk for surface and subsurface soils.  Only a  residential land use
scenario  results  in  future risks  exceeding  EPA's  acceptance
criteria.  The potential residential pathway of  concern is limited
to surface soil ingestion.

The remediation goals, according  to 40 C.F.R. §300.430 (e)(2)(i)
"shall establish acceptable exposure levels that are protective of
human health and the environment".   The following requirements must
be considered during the development of the remediation goals:

•    Applicable or  relevant  and appropriate requirements (ARARs)
     related to:
     -    acceptable exposure levels for systemic toxicants,
          acceptable exposure levels for carcinogens,
          technical limitations and
          uncertainty  factors.
•    Maximum Contaminant Level Goals (MCLGs) established under the
     Safe Drinking Water Act that  are set at levels above zero.
•    MCLs when the  MCLGs are  set  at zero  or  are not relevant and
     appropriate.
•    When the attainment of chemical-specific  ARARs will result in
     a cumulative risk in excess of IxlO'4.
•    Water quality criteria established under  the Clean Water Act.
•    Alternate concentration limits  (ACLs) may  be  established in
     accordance with CERCLA Section 121(d)(2)(B)(ii).
•    Sensitive habitats of species protected under the Endangered
     Species Act.

As required by Section 121  of CERCLA, as amended, remedial actions
must  attain  the  levels  or  standards of  control   for  hazardous
substances, pollutants, or contaminants specified by the ARARs of
federal  environmental  laws and  state environmental  and facility
citing  laws,  unless  waivers are  obtained.    According  to EPA

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guidance,  remedial  actions must  also  take  into  account  non-
promulgated- "to be considered"  criteria or guidelines if the ARARs
do not address a particular situation.

ARARs are distinguished by the  EPA  as  being either applicable to a
situation  or  relevant   and   appropriate  to  it.     Applicable
requirements  are  standards,   standards  of   control,  and  other
substantive environmental protection  requirements, criteria,  or
limitations promulgated under  federal or state law that specifi-
cally  address  a  hazardous substance,  pollutant,  contaminant,
remedial action, or other circumstance as defined in the NCP.

For a  requirement to be  applicable,  the remedial action  or the
circumstances  at the  site must satisfy all  the  jurisdictional
prerequisites  of  that  requirement.   For  example,  the  minimum
technology requirements for hazardous waste  landfills  under RCRA
would be applicable  if a  new hazardous waste landfill  were to be
built.

Relevant and appropriate requirements are standards,  standards of
control, and other substantive environmental protection require-
ments, criteria, or limitations promulgated under federal or state
law that, while not applicable to a  hazardous  substance, pollutant,
contaminant, remedial action,  or other circumstances  at a CERCLA
site,  address problems or  situations sufficiently similar to those
encountered at the CERCLA  site  so that their  use is well suited to
that particular  site.  Relevant and appropriate requirements are
defined  in  the NCP, 40 C.F.R.  §300.5.  For  example,  while RCRA
regulations are not applicable  to closing in-place hazardous waste
that was disposed of before 1980,   RCRA  regulations  for landfill
closure with hazardous substances in-place may be deemed relevant
and appropriate.

The NCP, 40  C.F.R.  §300.400(g)(2), specifies factors to consider in
determining what  requirements  of   other environmental laws  are
relevant and appropriate:

     •    The purpose of the requirement relative to the purpose of
          CERCLA

     •    The media regulated by the requirement

     •    The substance regulated by the requirement

     •    The actions or activities regulated by the requirement

     •    Variations, waivers,  or exemptions of the requirement
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     •    The  type  of  place  regulated  and  the  type of  place
          affected by the release or CERCLA action

     •    The type and size of facility or structure regulated by
          the requirement  or  affected by the release  or  contem-
          plated by the CERCLA action

     •    Consideration  of use  or potential  use  of  affected
          resources in the requirement

In  some circumstances,  a  requirement nay  be  relevant  to  the
particular site-specific situation but not be appropriate because
of differences in the purpose of the requirement, the duration of
the regulated activity, or the physical size or characteristic of
the situation it is intended to address.  There is more discretion
in the  judgment of  relevant and appropriate  requirements  than in
the determination of applicable requirements.

As mentioned earlier in this section, the only identified concern
at the  D.L.  Mud  site is  from ingestion of barium  contaminated
surface  soil under the  future  residential  exposure  scenario.
Barium  has been identified as  the  only chemical of concern  for
surface soils as summarized in Table #21. The remediation goal for
total barium in surface soils is 5,400 ppm.   This is a risk based
value  which  equates  to  an  HI  -  1  for potential  residential
receptors  exposed  to surface  soils.     At  this  concentration,
approximately 19,350 cubic yards of surface soils  (which have total
barium concentrations above 5,400 ppm)  need to be addressed.

A comparable media-specific remediation goal for  the  subsurface
soil  that  has  not  been fully  characterized but  is  obviously
contaminated with the high molecular weight hydrocarbon TICs cannot
be  calculated  using  established  risk  assessment  procedures.
Through the use of modified risk assessment procedures, including
additional sampling and analysis, it would be possible to better
define the  potential risks posed by the  TICs and other contaminants
contained in this area.  The  costs  of  conducting this  additional
evaluation is not deemed appropriate in comparison to the  assumed
volumes  present at  the site and  estimated remediation  costs.
Therefore,  remediation goals for the subsurface media will be based
on visual observation and  confirmatory sampling  comparisons with
pit closure requirements contained in Louisiana Statewide Order 29-
B, Section  129.B.7. as  specified below.   It  is estimated that
approximately 1,100 cubic yards of subsurface soils may need to be
addressed.
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             Louisiana 29-B Pit Closure Requirements

                         pH             6-9
                         Arsenic        10 ppm
                         Barium         40,000 ppm
                         Cadmium        10 ppm
                         Chromium       500 ppm
                         Lead           500 ppm
                         Mercury        10 ppm
                         Selenium       10 ppm
                         Silver         200 ppm
                         Zinc           500 ppm
                         Oil & Grease   < 1% dry weight
Although adverse  impacts on  the  Site's  ground water due to site-
related  contamination  have  not  been  identified,  the  remedial
objective requires  that the  potential for migration of hazardous
substances into the ground water  should  be eliminated.  Therefore,
no  remedial  goals  are  necessary for  ground  water,  however,
comparisons with  applicable  MCLs will be made as part of ground
water monitoring activities conducted for purposes of ensuring that
contaminants are not migrating into the ground water.

It is important to note that because the wastes found at the Site
after the 1987 cleanup are not, by  definition or characterization,
"hazardous wastes"  as defined by  the RCRA,  then RCRA  is not an
"applicable" ARAR.  Therefore,  there are no RCRA chemical-specific
requirements and none of the alternatives evaluated during the FS
will have to meet the RCRA Land  Disposal Restrictions which only
apply to "hazardous wastes"  (this  would change if  RCRA hazardous
wastes  are  identified  or  produced at  the  Site in  the future) .
Several "action-specific" requirements of RCRA would be considered
"relevant and  appropriate" ARARs  and are discussed individually
with each affected alternative or  in the comparative analysis and
selected remedy sections of this ROD.

According to  historical records  regarding past operations,  the
wastes  found at the Site consist  mostly  of  NOW  wastes presently
regulated by the State of Louisiana under Louisiana Statewide Order
No.  29-B.   All of  the  following alternatives will have  to meet
appropriate provisions of this Statewide Order.

VII. DESCRIPTION OF ALTERNATIVES

A FS was conducted to develop and evaluate alternatives to meet the
RAOs for the D.L. Mud site.  Remedial alternatives were assembled
from  applicable  remedial  technology  process options  and  were
initially evaluated for effectiveness, implementability, and cost

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based  on engineering  judgement.   The  alternatives  selected for
detailed analysis were evaluated and compared to the nine criteria
required by the NCP (see Section VIII.  of this ROD).  As a part of
the remedial alternative evaluation process,  the NCP requires that
a no-action alternative be considered at every site.  The no-action
alternative  serves  as  a  point  of   comparison  for  the  other
alternatives.

The  following alternatives  to  address site  contamination were
evaluated in detail in the FS.  The descriptions and evaluations of
remedial  alternatives included  in  this ROD  address  the  surface
soils contaminated with total barium and subsurface soils contain-
ing  visual  contamination.    As  described  below,  the  remedial
alternatives  for  each of  these  effected  media are  presented
separately with the exception of the  No Action and Institutional
Controls Alternatives  (Alts. #1 and #2).  Alts. #3 and #4 address
the surface  soil  barium problem and Alts. #5  and #6  address the
subsurface visual contamination.
   List of Evaluated Remedial Alternatives and Media Addressed

     Alternative Evaluated              Area of Concern Addressed

     Alt. #1 - No Action                Surface   and  Subsurface
                                        Soil Contamination

     Alt. #2 - Institutional Controls   Surface   and  Subsurface
                                        Soil Contamination

     Alt. #3 - Soil Capping             Surface Soil Contamination

     Alt. #4 - Barium Treatment         Surface Soil Contamination

     Alt. #5 - Biological Landfarming   Subsurface Soil
                                        Contamination

     Alt. #6 - Excavation and           Subsurface Soil
               Offsite Disposal         Contamination

For the reasons discussed  in previous  sections,  the  treatment of
ground water is not being considered as an implementable response
action and was not carried forward through the detailed development
of alternatives.  However, because some  inorganic contaminants were
detected  in  the  ground water and several  potential  alternatives
will result  in wastes being  left onsite  in  a disposal unit,  a
ground water monitoring program will be implemented in all  of the
evaluated aIternat ives.

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As part of the ground water monitoring program that is included in
each of the_. following alternatives (with the exception of the "No
Action" alternative) , use of existing ground water monitoring wells
is planned.   The possibility exists that the final  design of an
alternative's  remedy will adversely  impact the existing ground
water monitoring system and will thus require a reevaluation of the
need for  additional  wells.   If future monitoring  indicates the
selected remedy  does not prevent the  potential  for  ingestion of
contaminated ground water,  EPA will investigate the need for active
remediation of the ground water and would address resulting actions
in another Operable Unit and ROD.

Finally, all alternatives that result in waste remaining onsite at
levels that prohibit the future, unrestricted use of the property
will trigger the statutory requirement for a 5-Year Review.  This
review is conducted every five years  as a check to ensure that the
implemented remedy is still protective and performing as designed.

A brief description  of  the six alternatives evaluated to address
the contamination at the site follows.

Alternative #1      No Action

     Capital Cost:  $0
     Operation and Maintenance:    $0
     Total Cost  (1993 dollars):    $0
     Time of Implementation:
          Design/Remedial Action:  0 months
          Operation & Maintenance: 0 months
DESCRIPTION

Consideration of the No Action alternative  is a requirement of the
NCP.  Under this alternative, no remedial measures would be taken
to address the risks associated with the elevated barium concentra-
tions in the surface soils or the unknown potential risks associat-
ed with  the waste materials  found in the subsurface soils.   No
provisions would be made to restrict Site access or restrict future
use of the land or ground water.  Because there would be no active
remediation under  this  alternative,  no action-specific  ARARs are
relevant and  appropriate.   Because hazardous  substances would be
left  on site at  levels potentially harmful to  human  health,
statutory 5-Year Reviews [as required by the NCP §300.430(f) (5) (ii-
i)(C)] will be  conducted.   This  alternative will  not meet either
the primary or secondary remedial objective.
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Alternative #2      Institutional Controls

     Capital Cost:  $17,000
     Operation and Maintenance:    $170,000
     Total Cost  (1993 dollars):    $190,000
     Time of Implementation:
          Design/Remedial Action:  6 months
          Operation & Maintenance: 30 years
DESCRIPTION

Institutional controls are a frequently considered alternative to
"no-action"  because  the  implementation  of  relatively  simple
restrictions may adequately reduce the threat of low-risk sites to
an acceptable level.  This alternative consists of access and use
restrictions which  will  eliminate the possibility  that the only
exposure that has been identified as a potential risk at this Site,
future residential, can occur.  Alternative #2 would also provide
ground water use restrictions and long-term ground water monitoring
using existing wells to provide an early warning of any migration
of substances from the soils to the ground water.

Assumptions  for  this  alternative  that were used to formulate the
cost estimate are:

     •    Access restriction fence exists  and only minor upgrading
          and future maintenance is needed.
     •    Ground water monitoring will be required.
     •    Notice in deed would be  required to restrict future uses

The access  and  use restrictions described above would  apply for
both the  barium contaminated  surface soil and the contaminated
subsurface  soils presently found  at  the  Site.  The  alternative
could be implemented almost immediately, including fence upgrading
and sign posting.   Ongoing ground water  monitoring and a 5-year
review and reassessment of the adequacy of institutional controls
would be elements of this alternative.  Because there would be no
active remediation under this alternative,  no action-specific ARARs
are relevant and appropriate.  This  alternative  would meet the
primary remediation  objective but not the secondary  remediation
objective.
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Alternative #3           Soil Capping

     Capital Cost:  $380,000
     Operations and Maintenance:   $157,000
     Total Cost (1993 dollars):    $540,000
     Time of Implementation:
          Design/Remedial Action:  24 months
          Operation & Maintenance: 30 years
DESCRIPTION

The potential for contact  with  barium contaminated soil would be
reduced below that for preceding alternatives by isolation with a
protective soil cover.  A 12-inch soil cap over the areas contami-
nated with total barium concentrations above 5,400 ppm (approxi-
mately 8 acres)  is a cover system that would allow oxygen migration
to the underlying barium contamination while reducing the potential
for inadvertent contact with barium contaminated soil.  The 12-inch
thick soil cover would be revegetated with plants that are native
to the area or suited to local growing conditions to control soil
erosion and dust formation.  Along with continued access to oxygen,
gypsum (calcium sulfate) would be added to the soil to effect the
gradual conversion of more soluble  forms of  barium into the less
soluble form,  barium sulfate, to lessen the potential for migration
into the ground water.

This alternative would  have a relatively  low implementation cost
and require a  recurring cost for ground water monitoring to ensure
that no migration of barium occurs.  Monitoring would continue for
a  duration  sufficient  to  confirm that barium  remained immobile
and/or that the soluble forms of barium were undergoing conversion
to less soluble forms, a period  at least 5 years beyond the 1-year
implementation period.  At the 5-year  milestone, the effectiveness
of  the  alternative would be reevaluated,  and monitoring  would
continue for a suitable period.  Additional institutional controls
such as property deed notices/restrictions would  be  necessary to
ensure that residential development at the Site  does  not occur.
Action-specific  ARARs  such  as  RCRA capping  requirements  and
Louisiana Statewide Order 29-B would be evaluated during the design
process.    This objective would  meet the  primary  remediation
objective but not the secondary remediation objective.
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Alternative #4           surface Soil Barium Treatment

     Capital Cost: $430,000 - $11,220,000
     Operation and Maintenance:    $60,000 - $400,000
     Total Cost  (1993 dollars):    $830,000 - $11,300,000
     Time of Implementation:
          Design/Remedial Action:  2-5 Years
          Operation & Maintenance: 5-30 years
DESCRIPTION

Under this alternative, several treatment options were evaluated to
eliminate the potential for exposure to barium contaminated surface
soils and lesson the potential for barium migration into the ground
water.  The various treatment options evaluated included: Ex-situ
Froth Flotation, In-situ Chemical Fixation, and Solidification/Sta-
bilization.

Option A.   The Ex-situ Froth Flotation process  would be used to
remove barium from the soil  by adding various chemical reagents to
finely screened, barium contaminated soils and passing it through
a stream of fine bubbles to separate barium from more common soil
constituents.  The alternative involves the following steps:
     •    Construction of  soil stockpile areas,  treatment plant
          installation, with process monitoring facilities, and a
          personnel shelter

     •    Excavation  of  18 inches  of  barium  contaminated soils
          (approx. 39,000 cubic yards),  screening to discard the
          oversize fraction, slurring and conditioning the remain-
          ing  fines  with  flotation chemicals,  soil  flotation
          separation and cleaning, soil and barite dewatering and
          drying, oversize material disposal, cleaned soil place-
          ment, and recovered barium disposal

     •    Testing, .monitoring, and cleanup verification

     •    Plant dismantling

The froth produced during this treatment  process could possibly be
a characteristic RCRA hazardous waste due to the high concentration
of barium  and other metals that  would  be  collected.   As such,
several  RCRA  ARARs  would  be  applicable  including  those  that
regulate storage, transportation, and disposal of characteristic

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hazardous wastes.  This option would meet the primary remediation
objective  and  possibly  the  secondary  remediation  objective,
depending on the final disposition of the recovered barium.

Option B.  In-situ Chemical Fixation would be used to transform the
more soluble forms of barium (e.g. barium carbonate) present in the
surface  soils into barium  sulfate which is relatively insoluble.
The potentially bioavailable barium carbonate may be converted into
the inert barium sulfate using the innovative approach of irrigat-
ing the  affected surface soils with a  buffered sulfate solution
that has a pH adjusted with  dilute  sulfuric acid in the  4.0 to
5.0 range.   Only the  top 18 inches  would  need  to be  treated.
Application of  the  solution  would convert  barium  carbonate into
barium sulfate.   The pH range of 4.0  to 5.0 is well within the
tolerance range  of  most acid-tolerant crops, and these  would be
planted to control runoff, provide soil stability, and prevent dust
generation between periodic applications of buffered sulfate.

The  equipment  that  would  be used  includes   readily  available
construction and agricultural machinery.   Equipment requirements
would include:

     •     Excavation equipment
     •     Rotary tiller or disc plow
     •     Crawler-type tractor
     •     Tractor-mounted spray equipment
     •     Buffering chemical(s)

In  order to  achieve barium  carbonate/buffer  solution  contact,
tractor and soil tilling equipment would be required because of the
low permeability of the contaminated soil.  Bench-scale treatabili-
ty  tests  would be  conducted  to select  the  proper  buffering
solutions and to determine the reaction time required to set the
waste.    Leaching tests  may be needed to  verify the  reduction in
mobility of total barium.

This innovative technology involves  sowing acid-tolerant crops
(e.g.,  grasses), preparing and spray-irrigating buffered sulfate
solution at a rate consistent  with requirements  of the crop, soil,
and  locale.    The  buffered   sulfate  solution  may  also  contain
supplemental trace nutrients.  Leachable barium would be monitored
in treated soil until the barium became biologically and environ-
mentally  unavailable  to such a  degree  that the application of
buffered sulfate solution could be discontinued.  It is  estimated
the implementation time may be anywhere from three to five years,
depending on local growing conditions.  The Site  could be converted
to suitable uses consistent with  protection of  public health and
the environment  because  the  barium originally  present  as  barium

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carbonate would have  been converted to insoluble barium sulfate.
An extended ground water monitoring program would be implemented,
and  the  effectiveness  of  the  remedy would  be assessed  after
5 years.   Chemical fixation would  continue to  meet  the primary
remediation  goal  of  preserving the  Site  for industrial  use.
However, although the bioavailable barium carbonate will have been
changed to  nonbioavailable barium  sulfate,  the total  amount of
barium on site would remain the same; so this alternative would not
meet the  more conservative  secondary remediation goal  of  unre-
stricted residential use.

Option  C.    The  Solidification/Stabilization  (S/S)  treatment
alternatives would reduce the potential for barium leaching because
the barium contaminated  soil would be bound in an aggregated matrix
that reduces permeability to rain and applied water.  The concen-
tration of leachable barium would be reduced only slightly from the
original soil concentration by virtue of the dilution effect of the
binder (a pozzolanic portland cement).

Ex-situ stabilization is similar to  the in-situ alternative except
that the mixing of soil and binder is carried out in a mechanical
device such as a  pug  mill or cement mixer  as  opposed to the in-
place spreading of  bulk cement  and  cement-soil tillage with disc
harrows.  The  in-situ alternative would involve deep discing to mix
the cement with the top  18 inches of soil where most of the barium
is located.  Mobile  construction  equipment would be used to deliver
and spread the pozzolanic binder  and moisten it after it is blended
with the soil.     Unlike in-situ stabilization, however,  the ex-
situ option requires preparation  of a foundation; a stockpiling pad
for the collected soil; mobile  equipment to  excavate the barium
contaminated  soil;  stationary  equipment  to   screen,  mix,  and
transfer the  soil and cement;  and  irrigation  equipment  to  apply
water for curing.  The treated matrix would be placed back on the
ground and moistened to initiate curing.

Bench-scale treatability  tests  would be conducted to  select the
proper additives  and their ratios and to determine the curing time
required to set the waste adequately.   Leaching tests and compres-
sive strength tests would be conducted to determine the integrity
of the solid end  product  and verify the reduction  in mobility of
total barium.    Critical parameters  in  stabilization  treatment
include the selection of  stabilizing agents and other additives,
the waste-to-additive ratio, mixing  time,  and curing conditions.
All of these parameters  are dependent on the chemical and physical
characteristics of the hazardous substance.

Post-remedial ground water monitoring would be implemented, with an
effectiveness review at  five years after completion of the remedy.

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Solidification/stabilization of the  soils  would continue to meet
the primary remediation goal of preserving  the Site for industrial
use.   Although the barite  will  have been  stabilized,  the total
amount  of barium  onsite would remain  the same,  therefore this
alternative  would  not  meet  the  more  conservative  secondary
remediation  goal  of  unrestricted  residential use.   Appropriate
action-specific ARARs contained in RCRA  and/or Louisiana Statewide
Order 29-B would be evaluated during the design process.

Note:  as  stated earlier, the  next two Alternatives  address the
visually contaminated subsurface soils.

Alternative #5      Biological Landfarming

     Capital Cost:  $340,000
     Operation and Maintenance:    $69,700
     Total Cost (1993 dollars):    $410,000
     Time of Implementation:
          Design/Remedial Action:        2-5 years
          Operation and Maintenance:    5 Years
DESCRIPTION

Although  the   subsurface  soils  associated  with   the  former
impoundments were not fully characterized, it is known that these
materials contain a large  amount of organic TICs.  This alternative
was evaluated  to address the potential threats  these TICs could
pose on human health and the environment.

Nearly all  organic compounds  will undergo  biologically induced
decomposition under favorable conditions.   An economical method of
promoting biodegradation is through landfarming,  in which hydrocar-
bon-containing  soil is  spread in  a thin layer,  nutrients  are
applied,  and a vegetative cover is grown both to control wind and
water  erosion  and  to  enhance  the  microhabitat  to  encourage
microorganism growth and biodegradation  of organic contaminants.

In this alternative,  1,100 cubic yards  of hydrocarbon-containing
subsoil would be  excavated from its  current location, mixed with
gypsum to improve porosity and workability,  spread onto a suitable
surface,  supplemented with essential nutrients, seeded with a crop,
and irrigated.   Periodically  (at about four to six week intervals),
the crop would be tilled with conventional farming equipment,  and
the soil would be replanted.   The process would be repeated until
hydrocarbon  compound concentrations  fell  below yet-unspecified
levels, at which time the treated soil would be replaced with a new
charge of untreated soil,  and the process  would be repeated.  (The

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 soil would be biotreated until it is proven that residual  contami-
 nants  do  not  pose  an actual  and/or  potential risk  to  future
 residents.)  Excavation would be required  for the construction  of
 a  lined  storm  water collection pond to store surface runoff  from
 the land farm area.  Water stored in the pond would be reapplied  as
 irrigation water.  It is anticipated that two soil turnovers would
 be required for adequate  aeration and nutrient  contact.

 Land farming would be carried out in an  area of  at least 1/2 acre,
 and the time to treat 1,100 cubic yards probably would not  exceed
 about  four growing seasons,  provided Site  soil  (silts and  clays)
 proves workable.  The use of larger plots would  reduce the cleanup
 time,  but  the  effort probably would  require at least two  years,
 irrespective of the area used.  Ground water beneath  the Site would
 be monitored,  and the  effectiveness would be  evaluated  after
 five years.

 Equipment requirements would include:

     •    Excavation equipment
     •    Rotary tiller or disc plow
     •    Crawler-type tractor
     •    Irrigation pump, piping, and spray heads
     •    Nutrient injection pump, storage tank, and mixer

 As with other biological processes,  land farming would destroy the
 organic  compounds,  eliminating  the  perceived  risk  of  these
 substances at the Site.  Land farming requires a moderate capital
 and operating cost expenditure but carries no significant mainte-
 nance costs.  No 5-year review would be required.  Action-specific
 ARARs contained in Louisiana Statewide  Order 29-B would apply to
 this alternative.   This alternative would meet both the primary and
 secondary remediation objective.

 Alternative #6           Excavation and Offsite Disposal

     Capital Cost:  $220,000
     Operation & Maintenance: $0
     Total Cost: $220,000
     Time of Implementation:
          Design/Remedial Action:        12  months
          Operation and maintenance:    0 months
DESCRIPTION

Constituents that are consolidated in small areas lend themselves
to excavation and placement in a suitable landfill if the volumes


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and   site   conditions   are  favorable.     Visually  contaminated
subsurface soils at the D.L.  Mud Site appear to be consolidated in
a  relatively  small area,  making  this alternative  technically
feasible.  The total volume is estimated to be 1,100 cubic yards.

Assumptions used to develop the cost estimate are:

      •    A suitable landfill complying with EPA's CERCLA Offsite
          Policy is within 125 miles of the Site.
      •    Sampling  is  required  to  verify  all  contamination  is
          removed.
      •    No operation or maintenance (O&M)  costs are involved.

This  alternative  consists of providing access roads,  locating a
suitable  landfill,  obtaining  the  necessary  mobile  equipment,
removing the soil  from the Site, and placing  it  in the impoundment.
Cleanup of the visually contaminated areas could be accomplished in
less  than  one year at  moderate capital and operating  cost.   The
remedy would  be permanent  at  the Site,  but  it  would relocate the
contaminated soils to another repository rather than eliminate the
objectionable constituent(s)  from the soil.   No  5-year review would
be required.  This  alternative meets both the primary and secondary
remediation objectives.

Based on present information, the waste under this alternative to
be excavated and disposed off site is "non-hazardous", therefore, it
is assumed that this material is suitable for, and will be disposed
at, a RCRA,  Subtitle D disposal facility. Such disposal facilities
are not permitted to receive RCRA "hazardous  wastes."  In the event
that a suitable RCRA, Subtitle D facility is not located within a
125 mile radius,  then disposal at a RCRA, Subtitle C facility will
be evaluated.  If pre-disposal testing on this waste indicates that
all  or  potions of  the  waste  are RCRA "hazardous wastes,"  then
disposal at a suitable  Subtitle C facility, permitted  to receive
such wastes, will be required.

VIII. SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES

The EPA uses nine  criteria to evaluate alternatives for addressing
a Superfund site.   These nine criteria are categorized into three
groups: threshold,  primary balancing, and modifying.  The threshold
criteria must be met in order for an alternative to be eligible for
selection.  The primary balancing criteria are used to weigh major
tradeoffs among alternatives.   The modifying  criteria  are taken
into  account  after state and  public comment  is received  on the
Proposed Plan of Action.
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NINE CRITERIA

The nine criteria used in evaluating all of the alternatives are as
follows:

                        Threshold Criteria

Overall Protection  of Human Health and the Environment addresses
the way in which an  alternative would reduce, eliminate,  or control
the risks  posed by  the site to human health and the environment.
The methods used to achieve an adequate level of protection vary
but  may  include  treatment  and  engineering controls.    Total
elimination of  risk is often impossible  to achieve.   However, a
remedy must  minimize risks  to  assure that human  health  and the
environment are  protected.

Compliance with  ARARs. or "applicable or relevant and appropriate
requirements,"  assures that an  alternative will  meet all related
federal, state,  and local requirements.

                    Primary  Balancing  Criteria

Long-term Effectiveness and Permanence addresses  the ability of an
alternative to  reliably  provide long-term protection  for human
health and the  environment  after the  remediation goals have been
accomplished.

Reduction of Toxicitv. Mobility,  or Volume of Contaminants through
Treatment assesses how effectively an  alternative will address the
contamination on a site.   Factors considered include the nature of
the treatment process; the amount of hazardous materials that will
be destroyed by the  treatment process; how effectively the process
reduces the toxicity, mobility,  or volume of  waste;  and the type
and quantity of contamination that will remain after treatment.

Short-term Effectiveness  addresses the time it  takes  for remedy
implementation.   Remedies  often require several years for implemen-
tation.  A potential  remedy is evaluated  for the  length  of time
required for  implementation  and the potential  impact on human
health and the environment during implementation.

Implementability addresses the ease with which an alternative can
be accomplished.  Factors such as availability  of materials and
services are considered.

Cost (including  capital costs and projected long-term O&M costs) is
considered and  compared  to the  benefit  that will  result  from
implementing the alternative.


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                        Modifying  Criteria

State Acceptance allows the State to review the proposed plan and
offer comments to the EPA.   A State may agree with, oppose or have
no comment on the proposed remedy.

Community  Acceptance  allows  for  a  public comment  period  for
interested persons  or organizations  to  comment on the  proposed
remedy.  EPA considers  these comments in making its final remedy
selection.   The  comments  are  addressed  in  the  responsiveness
summary which is part of this ROD.

SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES

The comparative  analysis  was  conducted to  evaluate the  relative
performance of each alternative,  compared to the  other  alterna-
tives, in relation to each specific evaluation criterion.

     4    Based on the RAOs, the no action (Alternative #1) alter-
          native does not meet the protectiveness of human health
          and the environment criterion  for risks  to  residential
          children, however, existing land use  is  protective of
          children's  health.    Institutional  controls  (Alterna-
          tive #2) would control exposure through fencing and deed
          notices/restrictions to ensure that  future  residential
          use of the property does not occur.  The froth flotation
          alternative (#4A) is somewhat  more protective  than the
          other alternatives because the barite is actually removed
          from the soil and taken off of the site. Soil capping is
          slightly less protective than  froth  flotation  because,
          although  the  exposure  pathway is blocked,  the  small
          amount  of   bioavailable   barium  is  still   in   the
          bioavailable form at the end of the remedial action.  The
          other  three alternatives would  treat  the  barium  and
          reduce the mobility and potential for exposure;  however,
          the total barium on the site would remain constant and so
          would not meet the RAO.

          For  subsurface  soils,  the  no   action   (#1)   and
          institutional controls (#2) alternatives do not meet this
          criterion because the unknown risks will still be present
          and  uncontrolled.    The institutional controls  could
          provide a limited level of  protectiveness, however, the
          unknown nature of the contaminates make it difficult to
          ensure that appropriate controls are imposed to monitor
          this protectiveness.  Both  alternative #5 and  #6  will
          provide a high level of protectiveness to human health
          and the environment.

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 Based  on the  RAOs,  all  of the  alternatives meet  the
 compliance  with ARARs criterion.   The froth  flotation
 alternative (#4A) has more restrictions and ARARs to meet
 than the other treatment  alternatives  because the froth
 created  will  probably classify  as a RCRA  "hazardous
 waste" and  will  need to be managed  as  such.

 Existing data  (and perhaps new data)  would need to  be
 compared to the standards to see that the  no action (#1)
 and  institutional controls  (#2)  alternatives meet  the
 criterion for  subsurface  soils.   At present there is a
 State ARAR  that  lists limitations for pit closure that
 may not be met for the subsurface  material in the former
 impoundment area.

 The no action  alternative (#1)  does not meet the  long-
 term effectiveness and permanence criterion. Alternative
 #2, institutional controls, will meet  this criterion by
 ensuring that future residential use of the property does
 not  occur  through the  imposition of  deed notices and
 restrictions.  Soil capping (#3) is not as effective in
 the long-term  as chemical fixation (#4B), or S/S  (#4C)
 because soil capping  leaves the bioavailable barium in
 the  bioavailable state until the  gypsum added as  an
 amendment to the contaminated site soils converts barium
 carbonate into acid-insoluble barium sulfate.  Chemical
 fixation (#4B)  would  chemically convert the bioavailable
 barium  carbonate  to  a  nonbioavailable  state  (barium
 sulfate); this conversion is essentially permanent.  The
 S/S alternatives would immobilize the barium in the soil,
 but  the  long-term  effectiveness  is  unknown  due  to
 potentially adverse  effects from  future  environmental
 changes on the  remaining solidified mass.   The total mass
 of  barium  onsite remains constant  for these three
 alternatives.   Froth flotation  (#4A)  also  treats the
 barium carbonate and removes it from the site so  that no
 long-term maintenance or monitoring would be needed.

 For  the  subsurface  soils  the  no  action   (#1)  and
 institutional controls (#2) alternatives do not meet this
 criterion.   Institutional controls will not necessarily
meet this criterion because long-term  effectiveness is
 difficult to evaluate given the unknown  nature  of the
 contaminants and associated risks  that this subsurface
 soil possesses.    Both  landfarming  (#5)  and offsite
 disposal (#6) alternatives will meet this criterion.
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The previous remedial actions conducted by the State in
1987 removed and treated contaminated soils, reducing the
toxicity and volume of the majority of contamination that
was present at  this  site.   For  this ROD,  the no action
(#1) and institutional controls  (#2)  alternatives do not
meet  the reduction  of toxicity.  mobility,   or  volume
criterion through  additional treatment.   Soil capping
(#3) may reduce the mobility because the barite would not
be on  the  surface  of the soils,  however,  it would not
affect toxicity or volume.   The  S/S alternative (#4C)
would decrease the mobility and the toxicity, but would
increase the volume  by an estimated 25 percent.   Froth
flotation (#4A) would decrease  the mobility, toxicity,
and volume of the soils at the site over the long term;
in the short term, this alternative will  create a much
more highly  concentrated  but low  volume  waste (froth)
during soil  treatment.   Chemical  fixation  (#4B)  would
decrease the toxicity  and   mobility of  the  soils  by
converting  the  barium carbonate  to  barium  sulfate;
although the total  mass of barium would remain the same,
the mass of the toxic barium carbonate would be reduced.

For   subsurface  soils,   the   no  action   (#1)   and
institutional controls (#2) alternatives do not meet this
criterion.   The offsite disposal  alternative (#6)  does
not address toxicity, mobility, or volume of contaminants
but rather moves the contaminants  to  another location
without  modification.    Landfarming   (#5)   addresses
toxicity,  mobility,  and   volume  by   destroying  the
contaminants through biodegradation.

Through proper controls processes during implementation,
all of the alternatives meet  the  short-term effectiveness
criterion through  the use  of  fencing  and  other  site
access controls.   The no  action (#1) and institutional
controls (#2) alternatives do not pose potential short-
term risk to the community  or workers  during implemen-
tation.   Of  the  active  remedial  alternatives,  froth
flotation (#4A)  and ex situ S/S (#4C) would have the most
risk to workers since the barium-containing soils would
be excavated, treated ex situ,  and then replaced in the
excavation.   A smaller risk  to workers would be posed by
the in situ  treatment  alternatives  (#4B and #4C)  since
the soils  would not be  excavated.  Soil capping (#3)
would  pose  the least  risk to  workers  and  offsite
residents since the soils would not be disturbed except
by the placement of the clean soil on top.
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All   alternatives  meet   the  this  criterion  for  the
subsurface  source  areas, although the  landfarming (#5)
and offsite disposal (#6) alternatives would pose a more
potential risk since contaminated soils would be handled.
The offsite disposal alternative would  also pose a more
potential  risk  to  the  community  because  contaminated
soils would  be moved  through  the  community  to  the
disposal facility.

The  no action  (#1)/  institutional controls  (#2),  and
capping (#3) alternatives are the most implementable and
have  the most proven technologies of the  alternatives.
Chemical fixation  (#4B)  is the next most  implementable
alternative;  the equipment used for  this, treatment  is
that which is used for general agricultural farming.  The
S/S  alternative (#4C)   is  slightly  more  difficult  to
implement;   compared   to   chemical    fixation,    this
alternative will require a fairly extensive treatability
study to demonstrate stabilization effectiveness.   The
least implementable is froth flotation  (#4A)  which is a
novel application of this technology.

For   subsurface  soils,  all  of  the  alternatives  are
implementable.    For  landfarming  (#5),   treatability
studies  would  need  to  be  performed  to  ensure  that
effective   and  timely   biodegradation   of  organic
contaminants is possible.  For offsite  disposal  (#6), a
suitable disposal  facility will need to be located  to
accept the contaminated  soils.

The  no  action (#1)   and  institutional controls  (#2)
alternatives are the least expensive alternatives.   The
next  alternative in  cost is soil  capping (#3) .    After
soil   capping,   the   costs  increase   from  chemical
fixation (#4C) to in situ solidification  (#4C)  to ex situ
solidification  (#4C).  Froth  flotation  (#4A)  is by  far
the most expensive.

For subsurface soils, the cost comparison  from least  to
most   expensive  is   as  follows:   no   action   (#1),
institutional  controls  (#2),  offsite   disposal   (#6),
landfarming (#5).

The Louisiana Department of Environmental  Quality  is  in
agreement with  the  selection  of Alternative  #2  and
Alternative #6 as the preferred remedy for the D.L. Mud
site  (see Appendix #3).
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          EPA solicited input from the community on the remediation
          alternatives proposed to address the contamination at the
          site.  Input  was  received  from both the  local citizens
          and from Dow/DSI.   Although not opposed to the preferred
          alternative,  the  local citizens  expressed a preference
          for a more conservative alternative (Alternative #3) to
          address the residual  barium in surface soils.   Dow/DSI
          commented that the preferred alternatives  (Alternative #2
          &  #6)  were too conservative.   A  full  listing  of the
          comments received  from the public  on the Proposed Plan
          and EPA's responses  is contained in the  Responsiveness
          Summary section of this ROD  (See Appendix #1).
IX.  TEE SELECTED REMEDY

Based on consideration of the requirements of CERCLA, the compara-
tive analysis  of  alternatives,  and public comments,  the EPA has
determined that  a combination  of Alternative  #2  (Institutional
Controls, Ground Water Monitoring) and Alternative #6 (Excavation
and Offsite  Disposal of Visually  Contaminated  Subsurface Soils)
will best provide  a  cost effective remedy that  is  protective of
human health and the environment.

As discussed in Section  IV of this ROD,  the  specific RAOs deter-
mined to be  necessary at the D.L.  Mud site are to  eliminate or
reduce  identified  and/or  potential  risks  by  preventing  the
ingestion  of  barium-contaminated  soils  and  by  reducing  the
potential for  migration  of  contaminants from  both  surface and
subsurface soils to  the  ground  water.  The  selected remedy will
meet these objectives by:

     establishing    and    enforcing    land    use    and    deed
     notices/restrictions  on  the  property  to  eliminate  the
     potential for ingestion of  barium contaminated surface soils
     by hypothetical future residents.

     excavating and  disposing  visually contaminated  subsurface
     soils  at an  offsite  disposal  facility to  eliminate  the
     potential for migration of  the contaminants into the ground
     water.

     monitoring ground  water  to  ensure that  waste  excavation
     actions are successful and potential ground water degradation
     from residual surface soil  contaminants does not occur.

Based  on information  currently  available  with  respect to  the
evaluation criteria and  the other alternatives,  EPA believes the

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preferred  alternative provides the best approach to achieve  the
remedial objectives.   This alternative will significantly  reduce
the risks from direct contact with site contaminants and eliminate
the potential for future ground water  contamination from existing
subsurface  contaminants  by removing and disposing  these contami-
nants offsite.   The preferred alternative will provide long-term
effectiveness as long as the land use and deed  restrictions  are in
place  to  ensure that residential  exposure  scenarios are  not
realized.   Although no risks were identified to trespassers,  the
existing   fence  that  encloses   the  highest   areas   of  site
contamination will  be mended and repaired, as needed, during  O&M
activities.  This will ensure site security and discourage illegal
disposal  of wastes onsite  such  as  has  happened  in  the  past.
Fencing needs may change  in the future depending upon activities at
the adjacent GCVS site and on future non-residential uses at  the
D.L. Mud site.

Long-term ground  water monitoring will  be conducted to evaluate
contaminant  existence  and  movement   and,  if determined   to   be
necessary, implement appropriate remedial  response.  There are no
expected  unmanageable  short-term risks  associated  with  this
alternative.  This alternative will also comply with all ARARs  for
excavation and offsite disposal of CERCLA  hazardous substances.

The  institutional  controls  alternative is considered  more cost
effective because the same  degree of protectiveness to human health
and the environment is realized at a much  lower cost.  Potential,
low level risks from site  contaminants were only identified under
the hypothetical future onsite residential  scenario.   No risks were
identified to existing offsite residents or hypothetical workers
and trespassers.  The active treatment alternatives are much less
cost effective than the preferred  alternative because, even after
conducting the treatment processes, each would  still require post-
treatment remedial  actions,  monitoring and/or land use restric-
tions.   EPA has concluded that  these alternatives  do  not  offer
additional protection in line with the additional costs necessary
to implement them.

In addition, some question remains as to the actual level of risk
posed by the residual barium in the surface soils'^ to hypothetical
future residents.  EPA is presently reviewing risk issues related
to barium that could have a direct bearing on the volume of surface
soils that  need  to be  addressed and/or  even on  the need   for
remedial action.  Imposing an Institutional Control/Ground Water
Monitoring remedy provides flexibility in  the  event that changes
are made in barium  toxicity factors that  would support a  lower,
acceptable risk from the residual barium in the surface soils.
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The active measures  (excavation and offsite disposal) proposed to
address  the  unknown  risks  associated  with  the  contaminated
subsurface soils  were deemed more appropriate  than delaying the
remedial 'decision  so that  additional,  costly risk  assessment
efforts could be  conducted in an effort  to  quantify the unknown
risk.  This course of action also meets the goal  of the 1987 State-
lead cleanup which called for the removal  of visually contaminated
soils.

As mentioned  earlier, the majority of potential concerns identified
by EPA during the NPL ranking of  this site were addressed during
the State-lead cleanup in 1987,  employing treatment technologies
that permanently and significantly reduced the volume, toxicity and
mobility of site contaminants.  This 1987 cleanup action included
the offsite incineration of over 685 tons  of contaminated liquids,
wastes and contaminated soils at the Dow Chemical U.S.A. permitted
hazardous waste facility in Plaquimine, Louisiana.

Although the selected alternative in  this ROD does  not in itself
satisfy CERCLA's preference for remedies that employ  treatment that
permanently  and  significantly  reduces the  volume, toxicity  or
mobility of the hazardous substances,  the overall remedial action
for this site (including the actions conducted in 1987)  does meet
this preference.   It  is  not appropriate nor practicable  to use
treatment  technologies that  will  permanently  and  significantly
reduce the volume,  toxicity  or mobility of the relatively low
levels of  residual hazardous substances  that remain at the site
because they will not provide a greater  overall,  cost effective
benefit to human  health  and  the  environment.    CERCLA's program
goals and expectations, as stated in §300.430 of  the  NCP, recogniz-
es that institutional controls should be used for relatively low,
long-term threats  when more  active  treatment remedies  are deter-
mined not  to be practicable.   The residual,  low-level  risks that
will remain  upon  completion  of this  ROD'S preferred  remedy are
minimal in comparison to  the risks that  existed at the site before
the 1987 State-lead cleanup.

A more detailed description of the selected remedy follows with
major cost assumptions provided in Appendix #4.   It should be noted
that certain engineering  considerations of the  remedy  may change
during the remedial  design.   Areas  that are  subject  to  change
involve  ground   water monitoring  locations   and  frequencies,
subsurface soil  excavation volumes and  disposal locations,  and
fencing activities.
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Engineering Remedial  Design

4 The  engineering remedial action plans will include: Work Plan,
Health  and  Safety  Plan,  Sampling  and  Analysis  Plan,  Quality
Assurance Project Plan, and Operation and Maintenance Plan.

4 The  engineering remedial design will not include intermediate
plans due to the  simplistic nature of the remedial  actions.

Site Preparation

• Limited site preparation  activities will be necessary to complete
the remedial  action.   Steps  to be taken include minor vegetation
clearing  to  assist  in excavation and  waste hauling activities,
construction  of  decontamination  facilities  adequate to  handle
excavation and sampling equipment,  and existing fence  and gate
repairs.

Subsurface Soil Excavation and Disposal

• The estimated volume of  contaminated subsurface soils that will
require excavation is 1,000  cubic yards.   This volume may change
during the remedial action  based on confirmation sampling results.
All visual contamination will be removed and confirmatory samples
will be evaluated based on the State Pit  Closure limitations as
established  in Table #22.   The volumes  required  for  backfill
include the volumes  of material necessary  to  fill  the excavated
areas up to existing  ground levels.

Operation and Maintenance

4 O&M costs assume an annual engineer's inspection  and report of
the condition of  the  site.   Issues to be investigated concern the
integrity  of  land-use restrictions,  fencing,  and  ground  water
monitoring wells  for  a period of at least 30 years.

* The annual  inspection will  include  ground water monitoring for
TCL volatile organics, TCL  base neutral/extractables and total and
dissolved TAL metals.  The  monitoring will utilize existing wells.
Results from the  ground water  monitoring will  be  included  in the
annual report  with an additional ground water  statistics  report
every five years.   This report will analyze ground water monitoring
results during  the preceding five years,  evaluating statistical
trends and relationships with background data.
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TREATMENT GOALS

Since active, onsite treatment of site contaminants is not a part
of  the  selected remedy, media-specific  treatment goals  are not
warranted.   Excavation goals, as  expressed  in Table #22,  for the
visually contaminated subsurface soils will be monitored during and
after excavation as part of  confirmation sampling.   In addition,
the excavated material will be characterized to ensure disposal at
an  appropriate  offsite  facility.    At present,  the  toxicity
characteristic leachate procedure  (TCLP)  waste characterization is
the most  important parameter.   RI  sampling indicated that the
contaminated  subsurface soils were not  RCRA  hazardous wastes as
defined by TCLP criteria which would allow the excavated material
to  be  disposed at  Subtitle  D landfill.   The  selected disposal
facility  may impose  additional  waste characterization sampling
before accepting the waste.

As mentioned earlier, ground water will be monitored annually for
at least 30 years after completion of the remedial action as part
of the OfitM and  5-Year Review activities  at  this site.   If at any
time during  this monitoring  EPA determines  that source treatment
actions  were  ineffective  in preventing  ground  water  quality
degradation which poses a  risk to  existing  or future users, then
additional investigative and  treatment alternative actions will be
implemented.  These additional actions would be implemented under
a separate Operable Unit and ROD.

Criteria to be evaluated will include statistical changes in ground
water contaminant concentrations, the identification and character-
ization  (including  risk   assessments)   of  contaminant  plume(s)
attributed to the site, and comparisons with appropriate drinking
water standards.   The  ground water monitoring program  will  be
developed during the Remedial Design and contained in the Operation
and Maintenance Plan.
X. STATUTORY DETERMINATIONS

EPA's  primary responsibility  at  Superfund  sites  is to  select
remedial  actions  that  are protective  of human  health and  the
environment.  Section 121 of CERCLA also requires that the selected
remedial action for the site comply with applicable or relevant and
appropriate environmental standards established under Federal and
State environmental laws, unless a waiver is granted.  The selected
remedy  must  also  be  cost effective  and utilize  treatment  or
resource recovery technologies to the maximum extent practicable.
The statute also contains  a preference for remedies that include
treatment as a principal element.  The following sections discuss


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how the  selected remedy  for the D.L. Mud  site meets the  statutory
requirements.

Protection of Human Health and the Environment

In  order to protect  human health  and the  environment  from the
actual  and/or  potential threats identified  at  the site,  the
potential for harmful exposures that create  those threats will be
eliminated.  The land use and deed restrictions will eliminate the
potential for residential exposure to the low level risks  associat-
ed with  the  residual barium in the surface  soils.   The visually
contaminated subsurface soils will be removed and disposed of at an
offsite  facility eliminating the  potential for these contaminants
to migrate into the ground water or surrounding environment.  Along
with ground water monitoring and  continuous  5-Year Reviews, these
actions  will provide  long-term,  permanent  protection  of  human
health and the environment.

Compliance With ARARs

Each component of the selected remedy will meet all applicable or
relevant and appropriate requirements.   The ARARs evaluated during
the RI/FS as potentially  applicable or relevant and appropriate are
presented below.   It is  important to  note that  several  of these
ARARs are included  in this discussion only because waste character-
ization  activities may  reveal  that wastes  to  be  excavated  and
disposed offsite are indeed RCRA  characteristic hazardous wastes.
At present,  none of the wastes identified at  the site are either a
listed or characteristic  RCRA hazardous waste.

Chemical-Specific ARARs

Chemical-specific ARARs regulate the release  to the environment of
hazardous substances having certain chemical or physical character-
istics or materials containing specified chemical compounds.  They
are important  in determining the extent of soil,  sediment,  and
ground water  requiring  remediation  as  well as  determining  the
residual levels of  hazardous substances allowable after treatment.

Chemical-specific ARARs do not exist for soil for the contaminants
at  the   site.   The  risk assessment   evaluated  to-be-considered
criteria  for  soil  and  sediment  including  reference doses  and
potency factors;  Noncarcinogenic residential risk  due to ingestion
of soil  by a  child was  found to  be 3.8.  Because this  value  is
above the 1.0 point of departure,  target concentrations for soil,
using risk-based criteria, are included as site-specific  remedial
goals.
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Location-Specific ARARs
Location-specific  ARARs  are  requirements   that relate  to  the
geographical position of the site.  The primary  location-specific
ARARs  relative  to remedial  action  pertain  to floodplain  and
wetlands.  The entire site is outside  the boundary of the 100-year
floodplain and does not contain wetlands.  Therefore, the require-
ments  of RCRA  40  C.F.R.  §264.18(b)  and Executive Order 11988,
Protection  of  Flood Plains, are  not  applicable or relevant and
appropriate  to  actions  on the  site.   These  regulations,  if
applicable,  would,  for  example,  affect the citing  of remedial
facilities.

Action-Specific ARARs
Action-specific  ARARs are  requirements  that define  acceptable
treatment  and  disposal  procedures  for  hazardous  substances.
Important action-specific ARARs that may affect the development and
conceptual  arrangement  of  remedial  alternatives are  discussed
below.

The definition of hazardous waste  is  critical in determining the
status of RCRA requirements that apply to the residually contami-
nated  soils  at  the  D.  L.  Mud  site.    Since  portions  of  the
residually contaminated soils were generated and managed before the
effective date  of RCRA  (November  1980),  RCRA is not  applicable
unless waste  material is  excavated.    RCRA requirements may  be
relevant and appropriate  if wastes disposed of before November 1980
are defined as RCRA hazardous waste or are sufficiently similar to
RCRA hazardous waste.

Based on review  of  the site history, EPA has not identified any
RCRA listed hazardous wastes at the site.  Since contaminated soils
did not result from disposal of a listed hazardous waste, the RCRA
mixture rule  [40 C.F.R.  §261.3(c)(2)(i)]  does not apply.   Soil
samples from locations with the highest total barium concentrations
detected were collected and analyzed during the RI; these samples
did not exceed TCLP  limits.  Therefore,  this regulation  is not
considered applicable.

RCRA land disposal restrictions (LDRs), 40 C.F.R. §268.41, prohibit
land disposal of characteristic wastes unless constituents in the
TCLP extract  are below  the concentration  limits.   Soil  samples
collected and analyzed during the  RI  did not exceed  TCLP limits.
Therefore,  this regulation is  not considered applicable.
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 Relevant and Appropriate  State  Standards

 The  following ARARs  from the State of  Louisiana are  considered
 relevant and appropriate  to  the  D. L.  Mud  site  because  of
 consideration    of     the    specific    factors    listed     in
 40 C.F.R. §300.400(g)(a).

 Louisiana Hazardous  Waste Management Regulations.  These regula-
 tions  state  standards for management of hazardous wastes.   Since
 TCLP testing shows that residually contaminated soils do not exceed
 TCLP  limits, these  regulations  are  not  considered  relevant  or
 appropriate.

 Louisiana Statewide Order No. 29-B (LAC Title 43:Part XIX).   These
 regulations   govern   the  storage,  treatment,  and   disposal   of
 nonhazardous  oil field wastes (NOW) generated from the drilling and
 production of oil and gas wells.  The residually contaminated  soils
 associated with former surface  impoundments at the D. L. Mud site
 were  generated  as NOW,  and  the  facility  was  not  a disposal
 facility.  Therefore,  this regulation is not considered applicable.
 The closure requirements and of f site treatment and use  requirements
 of  these  regulations are  relevant  and appropriate  for the
 subsurface soils  associated with  the former surface impoundments.

 Louisiana  Discharge  Air  Pollution  Control  Standards.     These
 regulations establish air quality standards and emissions limita-
 tions  for any source of air emissions  within the  state.    These
 regulations  are  relevant  and appropriate  for those  alternatives
 where  excavation  could result  in dust or other discharges to the
 air.

 As discussed in EPA's  August 1988 CERCLA Compliance with Other Laws
 Manual fEPA/540/G-89/006). action-specific ARARs should be refined
 as appropriate during  remedial design.

 Cost Effectiveness

 EPA  believes  that the selected remedy  is  cost  effective  in
 mitigating the threat of direct  contact and reducing the potential
 for  ground  water  contamination  from  site  wastes.    Section
 300.430(f)(ii)(D)  of  the NCP  requires  EPA  to  determine  cost
 effectiveness  by  evaluating the following  three   of  the  five
 balancing criteria to determine overall effectiveness:  long-term
 effectiveness and permanence, reduction of toxicity,  mobility or
 volume through treatment, and  short-term  effectiveness.   Overall
 effectiveness is  then compared to  cost to ensure that the remedy is
 cost effective.

With the exception of the No Action Alternative (Alternative #1),
 all of the alternatives that  address  barium contaminated surface
 soils provide long-term effectiveness and permanence, if properly
 implemented and maintained.  The selected alternative can be easily


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implemented and effective  in  the shortest time period.  Although
the  selected  remedy  does  not provide  a reduction  of toxicity,
mobility  or volume through treatment, all of  the other alterna-
tives, with the exception of Alternative  #4A  (Ex-Situ Froth Flota-
tion) , will still  require  some  form of  post-RA land use restric-
tions and long-term monitoring because wastes will be left onsite.
Alternative  #4A is estimated  to  cost  almost  sixty  times  the
selected  remedy ($11,280,000  as  compared  to  $190,000  for  the
selected remedy).   This  major increase  in cost is not considered
appropriate given the low level  risks associated with the residual
barium in the surface soils.

For  the  contaminated subsurface soils,   only the  selected remedy
(Alternative #6, Excavation and Offsite Disposal)  and Alternative
#5  (Landfarming) provide long-term effectiveness  and permanence.
Alternatives #1 and #2  (No Action and Institutional Controls) do
not  provide  long-term  effectiveness  because  risks  from  the
subsurface   soil   contamination   has   not   been   adequately
characterized. Comparing the  selected remedy with Alternative #5
shows that  the selected remedy is  much more  implementable  and
effective in  the  short  term  and at  a  lower cost  ($410,000  vs.
$220,000).

Utilization  of Permanent  Solutions  and Treatment or  Resource
Recovery Technologies to the Maximum Extent Practicable

EPA believes the selected remedy represents the maximum extent to
which permanent solutions and treatment/resource recovery technolo-
gies can be utilized  in  a  cost  effective manner for the D.L.  Mud
site.

Of those alternatives that are protective of human health and the
environment,  and comply  with  ARARs, EPA has determined that  the
selected remedy provides the  best balance in  terms of long-term
effectiveness and permanence,  reduction in toxicity, mobility, or
volume  achieved  through  treatment,  short-term  effectiveness,
implementability,  costs,  the statutory preference for treatment as
a  principal  element,  and  taking  into  consideration  State  and
community acceptance.

Preference for Treatment as a Principal Element

Treatment of the contaminated  surface and subsurface soils was not
found to be required or  warranted at this time based  on the  low
level risks associated with the residual barium contamination and
on the unknown risks associated with the relatively small volume of
localized contaminated subsurface soils.  Although  treatment is not
warranted at this time,  the overall remedial action for this site
does meet the  statutory  preference for  treatment as  a principal
element of the remedy.  To  address the source of contamination and
remove the principal threat to human health and the environment, a
State-lead cleanup was conducted at the site in 1987 as discussed
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in Section V.   This cleanup action included the removal and offsite
incineration of wastes from several areas of the site.

Because the selected remedy will result  in hazardous substances
remaining  onsite above  health based  levels, a  review will  be
conducted  within five years  after  commencement of  the remedial
action to  ensure that the  remedy continues  to  provide adequate
protection of human health and the environment.

XI.  DOCUMENTATION OF SIGNIFICANT CHANGES

The Proposed Plan was released  for  public comment in April 1994.
The Proposed Plan identified Alternative #2  and #6 , Institutional
Controls,   Subsurface Soil  Excavation and  Offsite  Disposal  and
Ground Water Monitoring as the preferred alternative for the D.L.
Mud site.   EPA reviewed all written and verbal comments submitted
during the public comment period.   Upon review of these comments,
no significant changes to the remedy,  as originally identified in
the Proposed Plan, were necessary.
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     Appendix #1



RESPONSIVENESS SUMMARY

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f   •  t  -'  •
                    >        f          •  •

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THE RESPONSIVENESS SUMMARY

The  Responsiveness Summary has been prepared  to provide written
responses  to comments submitted  regarding  the  Proposed  Plan of
Action  for the D.L.  Mud Superfund Site.  The  Summary is divided
into two sections:

Section I; Background of Community Involvement  and Concerns.  This
section provides a brief history of community interest and concerns
raised  during the remedial planning  activities at the  O.L.  Mud
site.
Section II. smrnngrv of Manor Comments Received.  The comments (both
oral and written) are summarized and EPA's responses provided.


I.   BACKGROUND OF COMMUNITY INVOLVEMENT AND CONCERNS

Overall interest  in the D.L. Mud  site  on the part  of  the local
residents,  local   government   officials,   and  the  potentially
responsible parties (PRPs) has been moderate.

Local citizen interest has been limited.   The  citizens  are quite
aware that the majority of concerns  in  the area  can be  traced to
the neighboring Gulf Coast Vacuum  Superfund Site.   They also are
aware that the 1987 State-lead cleanup of the site addressed most
of the contamination problems at the  site.  The concerns about the
D.L. Mud  site appear to center on the desire to see that a full
investigation of the site's condition is made before decisions are
made to walk away from  it.  This concern is based on the fact that
if EPA would rank  the  site  on the NPL, then there  must be grave
environmental threats  associated with it.   Great care  has been
taken throughout  the  investigative  process to  ensure   that  all
potential environmental threats are investigated.

Local government  official  interest  has  been  limited   as  well.
Although the site is not  in  the city of Abbeville,  the  Mayor has
been kept abreast of ongoing activities.  Several representatives
of the Parish Police Jury  have been both interested and helpful in
planning  activities and  have  attended  several  of the  various
community relations functions held  in the area.  The major concern
that these local government officials have expressed through this
process have concerned consistency with the other Superfund sites
in the area and with the desire to see that  EPA and its contractors
use local services whenever possible.

A technical assistance  grant (TAG) was awarded  to  the  citizen's
group called the Vermilion Association to Protect the Environment
(VAPE) in  1990.   Both VAPE  and TAG technical advisor  have been
involved  and  helpful  during the  remedial planning activities.
Recent concerns have been expressed  regarding the  opening of a

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children's camp in the area and any impacts site activities might
have on the camp and/or wandering campers might have on the site.
Written  comments  received  from VAPE  during  the  public comment
period are addressed in the next section.

PRP interest and involvement in the site has been much greater than
the local citizens.  Although there were over 100 PRPs identified
at this site,  only  two  former owner/operators have been directly
involved with remedial planning activities, Dow Chemical and Dowell
Schlumberger, Inc.  (Dow/DSI).  These two PRPs voluntarily conducted
the Remedial Investigation and Feasibility Study (RI/FS) activities
under the terms of  a June  1990 Administrative  Order  on Consent.
Correspondence  between and meetings  with Dow/DSI during  this
process generated several concerns to which EPA has appropriately
responded.  Official written comments received from Dow/DSI during
the public comment period are addressed in the next section.

II.  SUMMARY OF MAJOR COMMENTS RECEIVED

Public notice announcing the public  comment period  and opportunity
for a public meeting was  printed  in the Abbeville Meridional and
Kaplan Herald.  The public comment period began on  April 29, 1994,
and ended on May 28, 1994.  The formal public meeting was held on
May 10,  1994, during which EPA answered questions about development
of the RI/FS and remedial alternatives under consideration.  A full
account of the public meeting can be  found in the public meeting
transcript  which  is documented in the D.L.  Mud  Administrative
Record.

The public comments received during the public comment period and
EPA responses are summarized below.

ORAL COMMENTS RECEIVED DURING MAY 10. 1994 PUBLIC MEETING


1.   COMMENT; What cleanup activities occurred in 1987 and how much
did it cost?

     RESPONSE; As summarized  in Section II of the ROD,  the 1987
cleanup activities conducted under  the oversight  of the State of
Louisiana consisted of the following:

     •    Removal of the  tank  contents, destruction by incinera-
          tion, and disposal of ash  in  a hazardous  waste landfill.

     •    Decontamination and demolition of the tanks,  supports,
          and piping.

     •    Removal and disposal of  approximately 800 cubic yards of
          contaminated soil from eight onsite areas, including tank
          pads, one "bare" area, and two areas  identified by EPA in
          the southern portion of the site.

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          Placement  of  clean offsite fill material onsite in the
          excavated  areas.
On December 17, 1987,  Dow/DSI submitted a Report of Decommissioning
and Restoration of the D.L. Mud site which was  approved by LDEQ on
February 29, 1988.  A copy of this report can be found in the D.L.
Mud Administrative Record.  Information regarding the actual cost
of these activities is not presently available to EPA.


2.   COMMENT;  It was  mentioned during  the public  Meeting that
offsite  contaminants  were identified  but  this  was not  EPA's
responsibility to address.

     RESPONSE: Although EPA conducts a "baseline" risk assessment,
remedial action decisions must also include an evaluation of onsite
and offsite  contaminant concentrations to help the risk manager
determine  the  additional impact  that  onsite  contamination  is
presently or potentially having on human health and the environ-
ment.  As  part of this  evaluation,  background samples  are taken
from locations that best describe the natural surrounding area.  At
times, common, naturally occurring contaminants  are identified at
these  locations.   It  is beyond the scope of  CERCLA to  address
contamination that is not a result of site activities or releases.

No significant offsite contamination was  observed during the D.L.
Mud  investigation.    If  there  were, this  information would  be
transmitted to the local and State health officials.
3.   COMMENT; what is the visually contaminated material that was
found in the former impoundment area and what is the volume of this
material?

     RESPONSE; As mentioned in the ROD,  this material has not been
fully  characterized  although  it  is  estimated   that  there  is
approximately 1,100 cubic yards of visually contaminated material
and  associated  soils.   No  indications from  historical  records
indicate  what these  pits were  actually used for.   Analytical
results  using standard  methods  have been  inconsistent in  its
attempt to characterize the material,  although  it is apparent that
the material is similar to other oilfield exploration and produc-
tion wastes and products that have been identified at the neighbor-
ing Gulf Coast Vacuum and PAB Oil Superfund sites.


4.   COMMENT: It is mentioned that the  high ground water results
for several inorganics is due to high turbidity and that when the
sediments are removed, the high concentrations are eliminated.  How
does that  effect drinking water  for  people that  can  not filter
their ground water?

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     RESPONSE; After EPA conducted standard ground water sampling
that  indicated  elevated  levels  of  total  chromium,  additional
sampling  was conducted to  try and  identify  the nature  of this
contamination.   This  additional sampling  utilized  a  dedicated
sampling  procedure that would  more  replicate  actual ground water
conditions and pumping activities.   Unfiltered results  from this
sampling  method indicated  that  the chromium was  part of  the
sediments that were analyzed with the ground water using the cruder
sampling  method  and  not  an accurate description of ground water
quality.  It is believed that the dedicated sampling procedure is
more representative of local drinking water scenarios.

No drinking water wells would be placed in the  upper  reaches of the
Chicot Aquifer where the ground  water samples were  taken for the
D.L. Hud  site characterization.  Samples taken from the deeper
depths where surrounding citizens get there drinking water do not
have the high turbidity that is associated with the D.L. Mud wells.


5.   COMMENT: Could  the  chromium in  th« ground water  come from
material  that was  removed  from the site  during  the 1987 cleanup
activities?

     RESPONSE: It is possible that the materials removed during the
1987 cleanup contained chromium because chromium is a constituent
of  common materials  associated  with  the  oilfield  exploration
industry.  However, no relationship has been  identified between any
of the  former  source  areas and the chromium  in  the ground water
sediments.


6.   COMMENT: After  implementation  of  th«  remedy,  what  can the
property be used for?

     RESPONSE; The  land use  restrictions will prohibit residential
and agricultural use of the  property.  The only potential risk that
was identified during the risk assessment was to future residential
children.  Potential  risks  associated with agricultural use of the
property was not quantified, therefore,  the property will not be
used for farming or grazing purposes either.  This means that the
property could only be used for industrial uses.


7.   COMMENT: What type of offait*  disposal facility  will the
excavated subsurface soils go to?

     RESPONSE;  Because  the waste  is  not  classified as  a RCRA
"hazardous waste",  this material is  subjected  to  the RCRA Subtitle
D requirements  as  well as  EPA's CERCLA  Offsite Policy.   If an
appropriate Subtitle D landfill  facility  can  not be found with a
125 mile  radius of the site, then consideration will be given to
use  of  a  Subtitle C landfill.   The use  of any  other off site

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treatment  or disposal options could also  be  considered (such as
offsite-incineration  at an approved facility)  during the Remedial-
Design but the final decision would have to comply with the Offsite
Policy.

The State of Louisiana will have an important role in determining
the appropriate landfill to accept this waste.  During the Remedial
Design,  the State  will have  to approve  the  proposed disposal
facility before any material will be disposed offsite.


8.   COMMENT! Will  the  site be de-listed  from  the  HPL  after the
monitoring of the ground water  and will the PRP« still  be liable
after it is?

     RESPONSE; To de-list a site from the NPL,  all remedial actions
must be  completed to ensure protection of human health  and the
environment.   This  site will  be eligible  for de-listing  upon
successful completion of the excavation and of fsite disposal of the
contaminated subsurface soils and institution of the land use and
deed restrictions.

Ground water monitoring activities are to be conducted as part of
Operation and Maintenance activities for at  least  30 years.   In
addition,  5-Year  Reviews will be  conducted every  five years to
ensure that  the  remedial actions and  institutional controls are
still protective of human health and the environment.   If at any
time it  is determined  that  the remedial  actions  implemented to
protect human health  and the environment are  not successful, EPA
has the discretion to  place the site back on the  NPL without having
to re-rank it.

The NPL  status  of a  site  does not  have any  bearing on  a PRP's
liability.  Therefore, if the site is de-listed  and problems arise
at a later time,  EPA can pursue the PRPs  to address these problems
if appropriate.


9.   COMMENT; Who will  be  conducting  the Remedial Design  and
Remedial Action?

     RESPONSE; EPA is going to make every effort to have the PRPs
conduct the remedial  activities at this  site.   In  the event that
voluntary conductance of the remedial activities is not obtained,
several alternate enforcement options are available for consider-
ation.   EPA also  has the authority to conduct the remedial actions
using fund monies in  the event  PRPs  fail to commit to conducting
the remedial activities in a timely manner.


10.   COMMENT i Will local services be used to conduct the remedial
activities?

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     RESPONSE; Any and all inquiries for work at the site will be
forwarded- to  the  PRPs under the assumption that  any future work
will be let out under their  direction if an agreement is reached
whereby the they conduct the Remedial Design and Remedial Action.
If EPA conducts the work using fund monies, then official Federal
Acquisition regulations will be followed including formal bidding
procedures .

The following comments were received in written form during the 30-
day public comment period.
11.  gnMUBMT* what happens after 30 years vhen the ground water is
no longer monitored?

     RESPONSE ; The need for ground water monitoring is based on the
concern that the potential exists for contaminants remaining onsite
after the remedial action to migrate into the ground water.   This
monitoring will also be used  to  reassert that the initial determi-
nation that no ground water concerns exist that require remediation
was correct.  As stated in the ROD, the monitoring of ground water
will be conducted at least for  30 years.   The  results of initial
ground water monitoring will establish  the need  for  additional
ground water monitoring after 30 years.  If it is determined that
additional ground water monitoring is  needed after 30 years then
the O&M Plan will be amended to reflect this need.  The time period
for this  monitoring of 30  years  is  established  more  for  cost
estimation purposes than on a scientific basis.


12.  COMMEHT; The Proposed Plan contains plans for long tent ground
water monitoring that would detect any changes in the current level
of constituents in the ground  water.   The Plan  should include
provisions that would provide a  mechanism for initiation of ground
water remediation if the  groundwater  is  impacted  by the contami-
nants remaining onsite. In addition, sediment in the ground water
was determined  to  cause   the  ground  water  to exceed  MCL.   If
additional  problems  result  from the  sediment containing  heavy
metals, a mechanism should be included to address these problems.

     RESPONSE: The ROD contains statements that will require the
investigation and remediation,  if appropriate,  of any identified
problems with  ground  water  that arises as  part  of  the post-RA
ground  water monitoring  program.   The  need  to conduct  these
additional activities will be based on the review of ground water
data as it is developed.  The review process will be developed as
part of the  O&M Plan and  will  look at contaminant concentrations
and statistical changes  over  time  as  well  as  drinking  water
criteria.    It is not  necessary at this  time  to state  what the
remedial mechanism would  be.   This will be decided  based on the
particular  circumstances  that  surround  the decision  to address
newly identified ground water concerns.

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 13.   COMMENT;  According  to  the  Proposed  Plan,   the preferred
 alternative will leave final barium levels on the D.L.  Mud site at
 a  much higher level than the final levels after treatment at  the
 Gulf  coast Vacuum and PAB oil sites.  TAPE would like to encourage
 EPA  to  require  Alternative  #3,  soil  capping as  the preferred
 alternative to address the barium contaminated  surface soil.

      RESPONSE;  Although it  is true  that residual  surface soil
 barium concentrations will be higher  in certain locations than at
 the Gulf Coast Vacuum and PAB Oil  Super fund Sites after treatment,
 the need to implement the soil capping remedy in lieu  of institu-
 tional controls is  not warranted.

 First,  the levels  that will be  left at D.L. Mud  are  not  at
 concentrations that pose a high significant or principal threat to
 human health  or  the environment.    The  decision to implement  S/S
 treatment at Gulf Coast  Vacuum and PAB Oil on  contaminated soils
 was not just  based  on the need to  address barium  but to address
 other contaminants as well,  which  taken together, pose  a much more
 significant risk that the residual  barium does at  D.L. Mud.   The
 implementation of institutional controls  provides  just as good a
 level of protectiveness to human health and the environment as does
 the soil capping alternative.

 Second, even after treatment, the treated waste will be  left onsite
 and institutional controls will be established  at both Gulf Coast
 Vacuum and PAB  Oil.  These controls  will prohibit every kind of
 future use in the areas of the site that contain the treated waste,
 including industrial uses, which will be possible at D.L. Mud under
 the land use restrictions presently considered.  In addition, even
 after implementing the soil  capping  remedy, institutional controls
would have to be established prohibiting future disturbances of  the
 cap.   Thus we would  be conducting treatment for treatment sake,  and
 not generating any additional protectiveness.

 Finally, there remains some  debate regarding  the actual risk posed
 by the residual barium.   This issue  is presently being  reviewed by
 EPA.   If in the future, it is decided that  existing  risk assessment
 factors  need  to  be adjusted which  result  in the lowering  of
potential risk  calculations  to  below  EPA action  levels (i.e.,
Hazard  Quotient <1.0), then  the selected  remedy will provide  the
most  flexibility to react to this change,  if appropriate.


 14.  COMMENT; The fencing at the D.L.  Mud site does not currently
extend  to the northern property boundary.   The area on the site
north of the existing fence contains surface soil contaminated with
barium  above the action level of  5,400  ppm.   This  area should be
surrounded by a  fence  and an  alternative  access road  (vhioh
currently transverses this area unimpeded) should be provided.

     RESPONSE; The fencing component of  the remedy  is included  for

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site security  reasons  and not risk abatement reasons.   The site
fence presently discourages site access to the former process area
for  trespassers and  potential  illegal  dumping.    As has  been
mentioned  earlier,  no  potential risks have been  identified  to
hypothetical trespassers or users of the property under any other
scenario other than the future residential scenario.  The decision
to fence the northern  area of the site is  one  which the current
owners of  the  property must decide.   If the decision is made to
fence this area,  then  provisions  for access to  the neighboring
property which presently transverses this  area will be provided
for.

15.  COMMENT; The Proposed Plan calls for site access restrictions.
When developing the appropriate restrictions, please remember to
take into consideration tne Woodmen of the World camp located vest
of the site.   The  restrictions must be adequate  to prevent site
access by the campers.

     RESPONSE;  The proposed plan and selected remedy call for land
use restrictions which will be memorialized in deed restrictions.
Although  access restrictions are  desirable for site  security
reasons,  nothing on the site poses a potential risk to humans under
any exposure scenario other than for hypothetical residents.

During the excavation activities,  all  care  will  be taken  to
eliminate  potential  risks to  trespassers  which might  come into
contact with temporarily exposed contaminants or physical hazards
(i.e.,  open excavations).   The  existing  fence  is  adequate  to
discourage  trespassing  in  the  excavation  area.    The cost  of
installing site access  controls that will ensure the prevention of
trespassers is not warranted given  the  lack of  potential risks
posed by site contaminants on these potential receptors.


16.  COMMENT;  A procedure should  be  established to  monitor an;
onsite impacts to  the  D.L.  Mud  site  caused by   the  remedial
activities  at  the  Gulf Coast  Vacuum  site.  If  contamination is
detected, a process should be in place to provide site remediation.

     RESPONSE;   It  is  beyond the  scope  of  this  ROD  to address
contamination or releases that emanate from the Gulf Coast Vacuum
site.  The  Gulf Coast  Vacuum RODs  adequately address the need to
monitor their  remedial activities to  identify  potential offsite
migration of contaminants.  If during ground water monitoring, 5-
Year Reviews,  or  other  O&M activities,  it  becomes  obvious that
additional  contamination  concerns  exist at D.L.  Hud, then source
investigations  of   this  contamination will  be  a   part  of  the
evaluation  into the need for additional site remediation.


17.  COMMENTt  EPA  should:  implement  a  program  to  monitor  the
surrounding agricultural fields, grasing lands and aqua culture for

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potential contamination from air emissions and surface water runoff
from the site, establish continuous offsite monitoring stations to
monitor the quality of the air during organic contaminant removal,
and  establish an ongoing  program  to monitor the  quality of the
vater  in  individual  water veils surrounding the sit* and provide
the analytical results to  the  citizens on a timely basis.

     RESPONSE;  Nothing in  the past  investigations  at this site
indicate the need to conduct these suggested monitoring activities.
Based  on this collected data,  the potential for offsite migration
of  site  contaminants  in  levels that could  be harmful  to human
health or the environment is limited at best.  Onsite air monitor-
ing  will  be conducted during the excavation of  the organically
contaminated subsurface soils.

18.  COMMENT; The citizens should be provided with opportunities to
participate in the decision making process during the design and
implementation phases of the remedial process.

     RESPONSE; The  public  will be kept  abreast of  all remedial
design and  remedial  action activities through the use of public
open houses and  periodic updates.    Input  on  remedial design and
action specifics will be gathered on  an as-needed-basis.

The following comments were received  from Dow/DSI.

19.  COMMENT; The uncertainties associated with the barium hazard
quotients calculated for the site make them overly conservative to
be the sole basis for a risk management decision.  These uncertain-
ties include:  l)  the use of a chronic RfD for short-term exposures/
2) use of an RfD derived  from a NOAEL where no higher concentra-
tions were tested, 3)  use of the lifetime RfD for child exposures,
when "the population most at risk is the adult male",  4) the use of
an exposure approach  that is not  universally accepted within EPA
Regions,  and 5) the assumption that all barium in soil is equally
as bioavailable as barium chloride in water.

     RESPONSE; In choosing  the remedy for  the D.L. Mud site, EPA
considered all pertinent information that relates to  the actual or'
potential risks  associated with the  site  contaminants.   The ROD
acknowledges that uncertainties exist with the risk assessment
(most  notably  the fact that  the  chronic and subchornic  RfD for
barium are the same)  and  the choice of institutional controls as
the selected remedy is based  partially on  an evaluation of these
uncertainties.

In response to the five general comments:

1) Risk Assessment Guidance for Superfund  (RAGS),  Part A, states
that toxicological  data from  IRIS and HEAST  should be  used in
conducting a risk assessment.   HEAST contains a subchronic RfD for
barium which was used for the  short-term exposure assessment.

-------
2)  This comment  relates to  the specific  approach EPA  used in
establishing  the  RfD values  contained in  IRIS  and HEAST.   EPA
Region  6 does not establish the RfD values contained in IRIS and
HEAST.  The Region requested assistance from EPA's Environmental
Criteria and  Assessment  Office  (ECAO)  to provide guidance on the
use of the existing values in HEAST and the possibility of using an
alternative value as proposed by the commentor.  This request has
been forwarded to  the RfD Work Group whose function is to official-
ly establish the values to be contained in these references.  Until
such time that an official response is acted upon by the RfD Work
Group, ECAO recommended that the existing subchronic RfD for barium
be used in the risk calculations at D.L.  Mud (see Appendix #5 of
the ROD).

3) As stated earlier,  EPA used the existing subchronic RfD for the
child, or short-term, risk  exposure.   This is in compliance with
RAGS, Part A.  It is not true that EPA used the chronic RfD value
because "no subchronic RfD  exists"  as was  stated in the comment
letter.  A subchronic RfD does exists and was used in the assess-
ment.  The merits of the subchronic RfD will be determined by the
RfD Work Group.

4) The exposure approach employed by the Region in conducting the
D.L. Mud risk assessment is in  compliance with national guidance
and with the spirit and intent of the June  1990, RI/FS Administra-
tive Order on Consent (AOC).  The agreed upon purpose of the AOC
was  to  determine  the threat to  the  public health, welfare,  or
environment  caused  by   the  release   or   threatened  release  of
hazardous substances from the site.  To do this, a baseline risk
assessment was conducted which calculated  a potential  risk to
hypothetical  children residents due   mainly to the  potential
ingestion of  surface soils contaminated with residual barium.  In
calculating  the  baseline   risk,  RAGs,  Part  A,   Section  8.2.2,
discusses the importance  of calculating the hazard index separately
for  chronic   and  subchronic exposure  periods.    The use  of the
integrated formula to determine "lifetime risks" for the purposes
of  establishing remediation  goals  is  a separate  function from
conducting the baseline risk.  As stated in the comment letter, the
use of the integrated formula is not  directly intended to calculate
baseline risk.

Once it is established that a unacceptable potential risk exists to
a hypothetical receptor (the future residential child), the process
of developing the remediation goal is undertaken.  The establish-
ment of the 5,400  ppm remediation goal  for  barium in surface soils
is based on a  conservative approach using existing RfD values.  The
acceptable  barium  concentration  under  the  lifetime  exposure
scenario (for oral ingestion only) is 19,000 ppm.   Because there is
an unknown additional risk due to the intake of barium through the
agricultural   uptake  scenario,   the   actual  acceptable  barium
concentration would be lower than 19,000 ppm. This lower value is
unknown, therefore, the use  of the more conservative value of 5,400

                                10

-------
 (which is the acceptable concentration for future residential child
 scenario) ppm is used.  This will ensure protection of the lifetime
 residential adult under the  agricultural scenario as well  as the
 future residential  child.

 5)  EPA  has evaluated  the concerns  expressed by  the  commentor
 regarding bioavaliability of barium in its different forms.  It has
 been  determined that  the  bioavariability of  barium from  barium
 sulfate  contaminated  soil  is likely to be substantially  less than
 100%, but the site specific study (ChemRisk, 1992) does not provide
 data adequate to define an absorption value for adjusting the RfD
 value  (see  Appendix /6  of the ROD).   In  addition,  the RfD Work
 Group will  evaluate the recent decision to exempt barium sulfate
 from  the reporting requirements of  the Emergency  Planning and
 Community Right-to-Know Act of 1986, and any impact this decision
 has regarding the issue of barium bioavailability.


 20.  COMMENT;   in a  recent  OBITER Directive (9284.7-16, December
 21, 1993),  EPA states that  ..."toxicological information other than
 that in IRIS may be brought to  the Agency by outside parties. Such
 information  should b«  considered  along with data  in  IRIS  in
 selecting  toxieological values;  ultimately,  the Agency  should
 evaluate risk based upon the best scientific judgement and consider
 all credible and  relevant information available  to  it".   During
 formulation  of the proposed plan of action for toe D.L.  Mud site,
 new toxieological information regarding the subchronic toxicity of
 barium was  made available to  EPA.   This new  information is not
 reflected in the Proposed  Plan of Action.

     RESPONSE; All information that  was submitted to EPA during the
 course of the RI/FS has been  considered  in selecting the  remedy at
 the D.L.  Mud site.  All information  submitted by Dow/DSI  regarding
 the subchronic  toxicity of barium  was evaluated  by  not only the
Region but also  -by ECAO.  This review determined that although some
uncertainty  exists as to the  merits  of the existing subchronic RfD
 for barium,  the continued use  of this RfD is appropriate.   Issues
regarding the merits  of the subchronic RfD are  continuing to be
 evaluated by EPA.  The selection of institutional controls has been
partly influenced by  the  existence of  this uncertainty  and  is
direct evidence  that  the additional  information submitted  by
Dow/DSI has  been considered.


21.  COMMENT; The cost  of the  selected remedy  (excavation and
offsite disposal to address  the visually contaminated subsurface
soils) is not adequately justified  as far as the derived benefits
to human  health  and  the  environment. The subsurface nature of this
material and its nonmobil nature exclude pathways of exposure and
potential resulting risks.   The  us* of  institutional controls is
more appropriate  for  the perceived risks assumed  to  be posed by
these subsurface materials.

                                11

-------
EPA's  proposed  remedy for  subsurface soils  was  based on  the
findings of  the  RI/F8  process  summarized  in the Proposed Plan of
Action.    EPA's  proposed  remedy includes  the  incorporation  of
Alternative #« which is the excavation and offsite disposal of the
subsurface soils in question.  This choice is based on the proposed
plan which states the "No specific risks vere quantified in any of
the obviously contaminated subsurface areas...".  In addition, the
Proposed states that "A comparison of shallow and deep samples from
the borings  indicates that the  residual  impacts of  former site
operations on  subsurface  soils are  limited  to shallow depths..."
and that Discrete EPA samples collected from  beneath the former
impoundment  area generally  indicate  similar  results...".    The
Proposed Plan also  shows  that  the D.L. Mud  site has not impacted
ground water quality.

     RESPONSE; The comment suggests that there is no  risk from this
material and thus no benefit in  cleaning  it up.   As discussed in
the ROD,  the visually contaminated  materials identified in the
subsurface soils in the  former   impoundment  area  have  not been
adequately characterized  so it  is  difficult  to determine "the
derived benefits to human health and the  environment" resulting
from the selected remedy.   Although the sampling  conducted on this
material and on the site as a whole support the general statements
regarding  quantified risks and  limited  existing impacts on the
surrounding  soils  and ground  water,  the   lack of  information
regarding the nature of this material prohibits a determination on
the future impacts these contaminants would have. In addition, the
lack of quantified risks is due to the fact  that  this material
contains a large amount of tentatively identified compounds that
prohibit the  quantification of their potential risk.  EPA therefore
strongly disagrees with this comment.

It vas determined that the effort of investigating this material
further to better ascertain the potential risks associated with it
were not cost effective when considering the  limited and localized
volumes of visually contaminated materials  that would need to be
addressed  by the selected remedy.    This determination  is also
consistent with one of the goals of the 1987 cleanup action which
was to  remove all  areas  of  visual  contamination.   The use of
institutional  controls  to address   the  obviously  contaminated
subsurface soils was not chosen based on the evaluation of the nine
criteria.   Program  goals  as stated in the NCP  expect EPA to use
treatment to address principal threat or  source areas in lieu of
engineering or institutional control measures wherever practicable.
Based on the unknown potential that this source  material has, the
high expected costs of further  investigation and on the relatively
low expected costs to implement the selected remedy, the selected
remedy provides  the most  appropriate and  practicable approach to
address these materials.
                                12

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                           FOR YOUR INFORMATION

The following is a list of maps not included in the administrative record due to the size of the
documents (larger than 11"X 17").  The maps may  be reviewed at U.S. EPA Region 6 upon
request.  Contact Mr. Jamie VanBuskirk (Enforcement Officer) at (214) 655-6767 for additional
information.

      "Survey Showing Monitoring Well Locations, Surface Soil Sampling Locations, Surface
      Water/Sediment Sample Locations and Subsurface Soil Sample Locations at the D.L. Mud
      and Gulf Coast Vacuum Sites",  March 25,  1991 - Preliminary Site Characterization
      Summary

      The following maps are located in LAD 981058019 Superfund Site File - SFSA Volume
      2;

             "Abbeville, LA 1978 Water Record Map - Section 36"
             "Abbeville, LA Water Record Map - Section 20"
             "Abbeville. LA 1978 Water Record Map - Section 19"
             "City of Abbeville, LA - Corporate Limit Boundaries
              as of August 25, 1982"
             "Abbeville, LA 1958 Water Record Map - Section 21"
             "Abbeville, LA 1958 Water Record Map - Section 34"
             "Abbeville, LA 1958 Water Record Map - Section 35"
             "Abbeville. LA 1958 Water Record Map - Section 38"
             "Abbeville, LA 1970 Water Record Map - Section 16"
             "Abbeville, LA 1973 Water Record Map - Section 17"
             "Abbeville. LA 1973 Water Record Map - Section 53"
             "Abbeville. LA 1973 Water Record Map - Section 56"

-------
I.  CHRONOLOGICAL LISTING

-------
        Appendix #2




ADMINISTRATIVE RECORD INDEX

-------
ADMINISTRATIVE RECORD INDEX
           DRAFT
SITE NAME:    D.L. MOD SUPERFUND SITE
SITE NUMBER:  LAD 981058019
INDEX DATE:   02/08/94

-------
                          SPECIAL NOTE TO THE READER
The potentially responsible parties' (PRPs) responses to the July 20, 1989 General Notice Letter
and October 20, 1989 Special Notice Letter are located at the U.S. EPA Region 6 office, Dallas,
TX due to the voluminous number of responses received from the PRPs. The notice letters may
be found in the  February 25, 1991 D.L. Mud Administrative Record (Document Nos. 000561-
00634). Included as attachments to the letters are the names of PRPs receiving the notice letters.

Due to the circumstances related to the site, most of the response letters do not necessarily affect
the selection of remedy. The PRPs' responses are in correlation to specific questions presented
by EPA in the general and special notice letters.

Please contact Mr. Jamie VanBuskirk, Enforcement Officer, at (214) 655-6767, if you wish to
view the response documents.  If the reader wishes to learn more about the D.L. Mud Superfund
Site, they may refer to the Gulf Coast Vacuum Administrative Record, the Gulf Coast Vacuum
Remedial Investigation/Feasibility Study, and the Record of Decision for the Gulf Coast Vacuum
Site.  These documents are provided in microfiche form and paper copy and are  located at the
Vermilion Parish Library - Abbeville, LA and Louisiana  Department of Environmental Quality -
 Baton Rouge, LA.

-------
                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MOD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
000907 - 000937
09/16/80
031
Hillol Ray, Environmental Engineer
Ecology & Environment,. Inc.
U.S. EPA Region 6 Superfund Site File
Site Inspection Report
"Potential Hazardous Waste Site Site Inspection Report"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
000938 - 000938
10/04/85
001
Martha McKee, Chief, Superfund Site Assessment Section
U.S. EPA Region 6
William DeVille, Louisiana Department of Environmental Quality
(LDEQ)
Cover Letter w/o Enclosures
Interim site inspection report from 07/09-10/85 site visit and
sample analyses for Gulf Coast Vacuum and D.L. Mud
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:

RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
000939 - 000953
11/12/85
025
Andy Goldberg and Bill Corbin
Louisiana State University  - Institute  for Environmental
Studies
U.S. EPA Region 6 Superfund Site Files
Site Inspection Report
"Potential Hazardous Waste Site Site  Inspection  Report"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:

COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
000964 - 000995
12/11/85
032
Jairo Guevara, Field Investigation Team  (FIT)  Chemical
Engineer
Ecology & Environment, Inc.
Keith Bradley, Region 6 Regional  Project  Officer  (RPO),  U.S.
EPA Region 6
Memorandum
Sampling inspection at Gulf Coast Vacuum  and  D.L. Mud during
07/09-10/85

-------
                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MOD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
000996 - 000997
12/16/85
002
G.W. Guerra
U.S. EPA Region 6
U.S. EPA Region 6 Superfund Site File
Tentative Disposition
"Potential Hazardous Waste Site Tentative Disposition"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
000998 - 000998
12/31/85
001
Martha McKee, Chief, Superfund Site Assessment Section
U.S. EPA Region 6
T.B. McDonald, Dowell Schlumberger, Inc.
Corre spondence
Request that  split sample results from lab analyses be
forwarded to  EPA Region  6 offices
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:

COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
000999  - 001002
01/07/86
004
G.F. Sievert, Manager of Safety and Loss  Prevention  and
Materials Control
Dowell  Schlumberger, Inc.
Martha  McKee, Chief, Superfund Site Assessment  Section, U.S.
EPA Region  6
Cover Letter  w/Enclosures
Re: 11/12/85  letter sent to LDEQ and  results  of analytical
work on samples  taken during  07/09/85 site visit
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001003  -  001004
01/30/86
002
Karen Young
U.S. EPA  Region  6
Myron Knudson, U.S.  EPA Region 6
Record  of Communication (ROC)/Attachment
Information on oilfield waste site near Abbeville,
LA

-------
                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
D.L. MUD SUPERFUND SITE
LAD 981058019

001005 - 001005
07/08/86
001
EPA Staff
U.S. EPA Region 6
U.S. EPA Region 6 Superfund Site File
Site Log
"Potential Hazardous Waste Site Log"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001006 - 001006
07/08/86
001
Martha McKee, Chief, Superfund Site Assessment Section
U.S. EPA Region 6
U.S. EPA Region 6 Superfund Site File
Tentative Disposition
"Potential Hazardous Waste Site Tentative Disposition"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001007 - 001007
07/18/86
001
Martha McKee, Chief, Superfund .Site Assessment Section
U.S. EPA Region 6
D.L. Mud, Inc., Houston, TX
Cover Letter w/o Enclosure
Re: 09/27/85 site inspection report and sample analysis
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001008 - 001027
09/30/86
020
Jairo Guevara, FIT Chemical Engineer
Ecology and Environment, Inc.
Keith Bradley, Region 6 RPO, U.S. EPA Region 6
Memorandum w/Attachments
Re: 06/16/86 sampling inspection

-------
                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MOD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001028 - 001054
09/30/86
027
Jairo Guevara, FIT Chemical' Engineer
Ecology and Environment, Inc.
Keith Bradley, Region 6 RPO, U.S. EPA Region 6
Memorandum
Sampling inspection at D.L. Mud on 06/15/86
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001055 - 001200
10/03/86
146
Jairo Guevara, FIT Chemical Engineer
Ecology and Environment, Inc.
Keith Bradley, RPO, U.S. EPA-Region 6
Memorandum w/Attachments
Analytical data from 07/09/85-07/10/85  FIT  sampling  inspection
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:

COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001201 - 001202
02/09/87
002
Presley Hatcher, Acting Chief,  Superfund Site  Assessment
Section
U.S. EPA Region 6
Robert Lawrence, Inactive  and Abandoned Sites  Division,  LDEQ
ROC
Re: Expanded Site Investigation
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
001203  - 001208
02/10/87
006
C.M. Maddin, Materials  Control
Dowell  Schlumberger,  Inc.
William DeVille, Administrator,  Inactive and Abandoned Sites
Division,  LDEQ
Cover Letter w/Attachment
Changed versions of  02/02/87 and 02/09/87 letters

-------
                  ADMINISTRATIVE RECORD INDEX

                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MUD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001209  - 001277
04/20/87
069
FIT - Region 6
Ecology and Environment, Inc.
U.S. EPA Region 6 Superfund Site File
Final Work Plan
"Expanded Site Inspection - Final Work Plan"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:

COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001278 - 001305
07/01/87
028
Environmental Monitoring Systems Laboratory, Office of
Research and Development
U.S. EPA - Las Vegas, NV
U.S. EPA Region 6 Superfund Site File
Aerial Photographic Analysis
"Aerial Photographic Analysis of Gulf Coast Vacuum and D.L.
Mud" (See "For Your Information")
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:

COM?ANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
001306 - 001307
10/12/87
002
William DeVille, Administrator, Inactive and Abandoned Sites
Division
LDEQ
Presley Hatcher, Acting Chief, Superfund Site Assessment
Section,  U.S. EPA Region 6
Correspondence
Site work completed to date
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001308 - 001346
12/17/87
039
C.M. Maddin, Materials Control
Dowell Schlumberger
William DeVille, Inactive and Abandoned Sites Division,  LDEQ
Report - Volume 2
"Report of Decommissioning and Restoration of D.L. Mud Site"

-------
                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MUD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001347 - 001347
01/20/88
001
Barry Nash, NPL Coordinator, Superfund Site Assessment Section
O.S. EPA Region 6
Bob Myers, NPL Operations Section, U.S. EPA - Washington, D.C.
Memorandum w/o Attachment
Re: Special Study Waste Review
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001348 - 001348
06/22/88
001
Allyn M. Davis, Director, Hazardous Waste Management Division
U.S. EPA Region 6
Honorable Brady Broussard, Mayor of Abbeville, LA
Cover Letter w/o Enclosures
Notification that D.L. Mud, Gulf Coast Vacuum, and Pab Oil
Sites are on the National Priority List of Superfund sites
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
001349 - 001349
09/29/88
001
Paul Conzelmann
Subra Company
Robert Layton Jr., P.E., Regional Administrator, U.S.  EPA
Region 6
Corre spondence
Requests EPA notify him when they visit Gulf  Coast Vacuum,  Pab
Oil, or D.L. Mud
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:

COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
001350  - 001350
10/17/88
001
Presley Hatcher, Acting  Chief,  Superfund Site Assessment
Section
U.S. EPA Region  6
William DeVille, Administrator,  Inactive and Abandoned Sites
Division, LDEQ
Cover Letter w/o Enclosures
Final Expanded Site  Inspection  Reports for Pab Oil,  Gulf  Coast
Vacuum, and D.L. Mud

-------
                  ADMINISTRATIVE RECORD  INDEX

                             DRAFT
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
D.L. MUD SUPERFUND SITE
LAD 981058019

001351 - 001355
06/26/89
005
Jairo Guevara, FIT Chemical Engineer
Ecology and Environment, Inc.
Ed Sierra, RPO, U.S. EPA Region  6
Memorandum w/Attachments
Water level measurements in monitor wells taken on  06/21/89
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:

COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001356 - 001356
10/05/89
001
Deborah Vaughn-Wright, Region 6 NPL Coordinator,  Superfund
Site Assessment Section
U.S. EPA Region 6
Unspecified
Correspondence
Re: Final Rule #6 and  Final Resource Conservation and  Recovery
Act of 1976 Rule
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001357 - 001357
10/13/89
001
Cathy Gilmore
U.S. EPA Region 6
U.S. EPA Region 6 Superfund Site File
Memorandum
Summary of 09/21/89 meeting between EPA Region  6  and Vermilion
Parish Police Jury on D.L. Mud, Gulf Coast Vacuum,  and Pab Oil
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001358 - 001358
03/07/90
001
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region  6
U.S. EPA Region  6 Superfund Site File
Sign-In Sheet
Sign-In Sheet for Remedial Investigation/Feasibility Study
(RI/FS) negotiations meeting

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                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
D.L. MUD SUPERFUND SITE
LAD 981058019

001359 - 001361
03/09/90
003
Sydney Rooks, Attorney, Legal Department
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Correspondence
Dow Chemical Company requests 30-day extension of time to
complete negotiation of Administrative Order on Consent for
RI/FS
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001362 - 001362
03/15/90
001
Sydney Rooks, Attorney, Legal Department
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Correspondence
Re: Negotiation of Administrative Order on Consent for RI/FS
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001363 - 001363
03/22/90
001
Robert Layton Jr., P.E., Regional Administrator
U.S. EPA Region 6
Sydney Rooks, Attorney, Legal Department, Dow Chemical  Company
Corre spondence
EPA extends RI/FS negotiation period and moratorium  for an
additional 30 days until 04/13/90
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001364  - 001365
05/18/90
002
Jamie VanBuskirk, Project  Coordinator
U.S. EPA Region  6
U.S. EPA Region  6 Superfund Site  File
Memorandum
Summary of  05/11/90 meeting for Gulf Coast  Vacuum,  D.L.  Mud,
and Pab Oil Sites

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                  ADMINISTRATIVE RECORD INDEX

                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MUD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
001366 - 001379
05/25/90
014
Mark Ezell, Technical Assistance Team  (TAT), Region  6
Ecology & Environment, Inc.
Michael Ryan, On-Scene Coordinator, Emergency  Response  Branch,
U.S. EPA Region 6
Site Assessment Report
"Site Assessment Report on D.L. Mud, Inc."
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001380 - 001381
07/03/90
002
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
W.J. Witt, Manager, CERCLA Operations,  Dow Chemical  Company
Cprre spondence
Notification of EPA Project Coordinator who is responsible  for
overseeing the RI/FS
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
001382 - 001390
08/02/90
009
Anthony Gardner, Regional TES 9 Manager
PRC Environmental Management, Inc.  (PRO
Karen Hartis, Regional Project Officer,  Superfund Managment
Branch, U.S. EPA Region 6
Cover Letter w/Attachment
Revised Work Plan for RI/FS Technical  Oversight
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001391 - 001419
08/15/90
029
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
W.J. Witt, Manager, CERCLA Operations,  Dow Chemical Company
Correspondence w/Attachments
EPA comments on RI Work Plan

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                  ADMINISTRATIVE RECORD INDEX
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
          DRAFT

D.L. MUD SUPERFUND SITE
LAD 981058019

001420 - 001462
09/01/90
043
Staff Consultants
CH2M Hill
Dow Chemical Cotnpany/Dowell Schlumberger, Inc.
Response to Review Comments - Volume 4
"Response to EPA Review Comments Dated August 15,
                                                                     1990"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001463 - 001530
10/01/90
068
Staff Consultants
CH2M Hill
Dow Chemical Cotnpany/Dowell Schlumberger, Inc.
Final Work Plan  - Volume 1
"Remedial Investigation Work Plan"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001531 - 001619
10/01/90
089
Staff Consultants
CH2M Hill
Dow Chemical Company/Dowe11 Schlumberger, Inc.
Final Sampling/Analysis Plan  - Volume 2
"Sampling and Analysis Plan Including Field Sampling Plan and
Quality Assurance Project Plan"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001620  - 001700
10/01/90
081
Staff Consultants
CH2M Hill
Dow Chemical  Company/Dowell  Schlumberger,  Inc.
Final Health  and Safety Plan - Volume  3
"Final  Health and  Safety Plan"
                               10

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                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MUD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001701 - 001702
10/10/90
002
W.J. Witt,  Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator,
Correspondence w/Attachment
Progress Report for September 1990
U.S. EPA Region 6
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001703 - 001705
10/19/90
003
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
W.J. Witt, Manager, CERCLA Operations, Dow Chemical Company
Correspondence
Formal approval of RI Work Plan on condition that minor
changes made and incorporated into final Work Plan
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001705 - 001707
10/31/90
002
Greg Goodman, P.E., Project Manager
CH2M Hill
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Correspondence
Preliminary field sampling schedule - RI
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF  PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001708 - 001709
11/09/90
002
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator,
Correspondence w/Attachment
Progress Report for October  1990
U.S.  EPA Region 6
                               11

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                  ADMINISTRATIVE RECORD INDEX
SITE NAME:
SITE NUMBER:
          DRAFT

D.L. MUD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001710 - 001710
11/29/90
001
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
U.S. EPA Region 6 Superfund Site File
ROC
Phone conversation with Gay Hanks (President - VAPEdisplay
memoryfield activities
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001711 - 001724
11/29/90
014
Greg Goodman,  P.E., Project Manager
CH2M Hill
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Correspondence w/Attachments
Sample locations
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001725 - 001751
11/30/90
027
Brett Padgett, Contractor Project Manager
PRC
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Report
"Quality Assurance Project Plan"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001752 - 001754
12/10/90
003
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project  Coordinator, U.S. EPA Region 6
Correspondence w/Attachment
Progress Report for November 1990
                              12

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                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MOD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001755 - 001763
01/03/91
009
Greg Goodman, P.E., Project Manager
CH2M Hill
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Correspondence w/Attachment
Identification of potential source area  - Gulf Coast Vacuum
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE :
DOCUMENT TITLE:
0017S4 - 001774
01/04/91
Oil
Greg Goodman, P.E., Project Manager
CH2M Hill
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Correspondence w/Enclosures
Outline of Risk Assessment
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COM?ANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001775 - 001775
01/15/91
002
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region  6
W.J. Witt, Manager, CERCLA Operations,  Dow Chemical  Company
Corre spondence
Comments on recent activities that have occurred regarding
ongoing RI/FS
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001777  -  001801
01/16/91
025
Brett Padgett, Contractor Project Manager
PRC
Jamie VanBuskirk, Project Coordinator,  U.S.  EPA Region 6
Report
"Follow-Up  Sampling  - Quality Assurance Project Plan"
                               13

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                  ADMINISTRATIVE RECORD INDEX
                             DRAFT:
SITE NAME:
SITE NUMBER:
D.L. MOD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001802 - 001807
01/22/91
006
Brett Padgett,  Contractor Project Manager
PRC
Jamie VanBuskirk,  Project Coordinator,  U.S. EPA Region 6
Cover Letter w/Enclosure
Technical review on Potentially Responsible Parties  (PRPs) RI
Risk Assessment outline
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
001808 - 002010
01/28/91
203
Brett Padgett, Contractor Project Manager
PRC
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Report
"Field Oversight Report - Phase 1 Activities"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002011 - 002014
01/29/91
004
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
W.J. Witt, Manager, CERCLA Operations, Dow Chemical  Company
Corre spondence
Outline of Risk Assessment
DOCUMENT  NUMBER:
DOCUMENT  DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT  TYPE:
DOCUMENT  TITLE:
002015  - 002017
01/30/91
003
Greg Goodman, P.E., Project Manager
CH2M Hill
Jamie VanBuskirk, Project Coordinator, U.S.  EPA Region 6
Corre spondence
Memorandum on completion of field support activities - RI
                               14

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                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MOD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002018 - 002020
02/08/91
003
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator,
Correspondence w/Attachment
Progress Report for January 1991
U.S. EPA Region 6
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002021 - 002109
02/13/91
089
Brett Padgett, Contractor Project Manager
PRC
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Report
"Field Oversight Report - Followup Sampling Activities"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002110 - 002125
02/22/91
016
Jacobs Engineering Staff
Jacobs Engineering Group, Inc.
U.S. EPA Region 6 Superfund Site File
Revised Work Plan
"Community Relations"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002126 - 002126
03/07/91
001
Greg Goodman, P.E., Project Manager
CH2M Hill
Jamie VanBuskirk, Project Coordinator, U.S.  EPA Region 6
Corre spondence
Notice of additional sample collection
                              15

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                  ADMINISTRATIVE RECORD INDEX
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
          DRAFT

D.L. MUD SUPERFUND SITE
LAD 981058019

002127 - 002129
03/11/91
003
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator,
Correspondence w/Attachment
Progress Report for February 1991
U.S. EPA Region 6
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002130 - 002246
03/25/91
117
Greg Goodman, P.E., Project Manager
CH2M Hill
Jamie VanBuskirk, Project Coordinator, U.S
Cover Letter w/Attachment
Preliminary Site Characterization Summary
     EPA Region 6
   - RI
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002247  - 002265
03/27/91
019
Greg Goodman, P.E., Project Manager
CH2M Hill
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Cover Letter w/Attachment
Summary Identification Contaminants  and List of Proposed
Indicator Chemicals - RI
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002266  -  002271
04/01/91
006
EPA  Staff
U.S.  EPA  Region  6
Public
Superfund Site Update Fact  Sheet
"Remedial Investigations Underway"
                               16

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                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME-:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
D.L. MUD SUPERFUND SITE
LAD 981058019

002272 - 002273
04/02/91
002
Greg Goodman, P.E., Project Manager
CH2M Hill
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Cover Letter w/Attachment
Additional background sample locations
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMP ANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002274 - 002274
04/04/91
001
Brett Padgett, Contractor Project Manager
PRC
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Correspondence
Review of "Preliminary Site Characterization Summary and
Summary Identification Contaminants and List of Proposed
Indicator Chemicals"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002275 - 002276
04/04/91
002
Brett Padgett, Contractor Project Manager
PRC
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Correspondence w/Attachment
Split sample data request
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002277 - 002279
04/09/91
003
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region  6
Correspondence w/Attachment
Progress Report for March 1991
                              17

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                  ADMINISTRATIVE RECORD INDEX
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
          DRAFT

D.L. MUD SUPERFUND SITE
LAD 981058019

002280 - 002280
04/15/91
001
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
Tim Knight, Inactive and Abandoned Sites Division, LDEQ
Correspondence w/o Enclosure
Request for review and comment on draft copy of PRP
deliverable "Summary Identification Contaminants and List of
Proposed Indicator Chemicals"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002281 - 002284
04/16/91
004
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
W.J. Witt, Manager, CERCLA Operations, Dow Chemical Company
Corre spondence
Re: Issues pertaining to D.L. Mud Site
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002285  - 002296
04/19/91
012
Greg Goodman, P.E., Project Manager
CH2M Hill
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Cover Letter w/Attachment
Exposure Scenarios Technical Memorandum and Notification of
Fate and Transport Models - RI
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:

COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002297  -  002298
05/07/91
002
Ronald  Ventola, Regulatory Functions Branch, Operations  &
Readiness Division
U.S. Army Corps, of Engineers
Dr. John  Beaver, Life Systems, Inc.
Correspondence w/Enclosure
D.L. Mud  is not in a wetland subject to  Corps,  of  Engineers'
jurisdiction
                               18

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SITE NAME:'
SITE NUMBER:
ADMINISTRATIVE RECORD INDEX

           DRAFT

 D.L. MOD SUPERFUND SITE
 LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
 002299 - 002307
 05/07/91
 009
 Anthony Gardner, Regional TES 9 Manager
 PRC
 Karen Hartis, Regional Project Officer, Superfund Management
 Branch, U.S. EPA Region 6
 Cover Letter w/Attachment
 Revised Work Plan for RI/FS Technical Oversight  (Cost
 documentation contained in the work plan is "Business
 Confidential" and is not included.  See "Special Note to the
 Reader")
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 002308 - 002310
 05/10/91
 003
 W.J. Witt, Manager, CERCLA Operations
 Dow Chemical Company
 Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
 Correspondence w/Attachment
 Progress Report for April 1991
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 002311 - 002312
 05/13/91
 002
 Jamie VanBuskirk, Project Coordinator
 U.S. EPA Region 6
 W.J. Witt, Manager, CERCLA Operations, Dow Chemical Company
 Correspondence
 Comments on "Exposure Scenarios Technical Memorandum and
 Notification of Fate and Transport Models"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 002313 - 002315
 05/31/91
 003
 Greg Goodman. P.E., Project Manager
 CH2M Hill
 Jamie VanBuskirk, Project Coordinator, U.S.  EPA Region  6
 Cover Letter w/Attachment
 Submittal of "Toxicological and Epidemiological Memorandum'
                              19

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                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MUD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002316 - 002318
06/10/91
003
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator,
Correspondence w/Attachment
Progress Report for May 1991
U.S. EPA Region 6
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002319 - 002320
06/12/91
002
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
W.J. Witt, Manager, CERCLA Operations, Dow Chemical Company
Correspondence
Approval of "Toxicological and Epidemiology Studies
Memorandum"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002321  - 002321
06/21/91
001
Wilma Subra, President
Subra Company
Jamie VanBuskirk, Project  Coordinator, U.S. EPA Region  6
Corre spondence
Request for copies of all  information  on  Pab Oil  and D.L.  Mud
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF  PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 002322  -  002352
 06/25/91
 031
 Greg Goodman,  P.E.,  Project  Manager
 CH2M Hill
 Jamie VanBuskirk,  Project Coordinator,  U.S.  EPA Region 6
 Correspondence w/Enclosure
 Background sampling  results
                               20

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                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME-
SITE NUMBER:
D.L. MUD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002353 - 002355
07/10/91
003
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator,
Correspondence w/Attachment
Progress Report for June 1991
U.S. EPA Region 6
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002356  - 002356
07/11/91
001
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
Wilma Subra, President, Subra Company
Correspondence w/o Enclosure
Data results collected from the  site
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002357  -  002358
08/09/91
002
Jamie VanBuskirk,  Project  Coordinator
U.S. EPA  Region  6
W.J. Witt, Manager,  CERCLA Operations,  Dow Chemical Company
Correspondence
Re: RI
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 002359  -  002361
 08/12/91
 003
 W.J.  Witt,  Manager,  CERCLA Operations
 Dow  Chemical  Company
 Jamie VanBuskirk,  Project Coordinator,  U.S.  EPA Region 6
 Correspondence w/Attachment
 Progress  Report  for July 1991
                               21

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                  ADMINISTRATIVE RECORD INDEX
SITE NAME:
SITE NUMBER:
          DRAFT

D.L. MOD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002362 - 002367
08/26/91
006
Greg Goodman, P.E., Project Manager
CH2M Hill
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region  6
Facsimile Transmittal and Attachment
Corrected caution exchange capacity  (CEC)  data for  soil
samples
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002368 - 002384
09/09/91
017
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
W.J. Witt, Manager, CERCLA Operations,  Dow Chemical  Company
Correspondence w/Attachments
Draft RI and Risk Assessment comments
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002385  -  002408
09/09/91
024
Brett Padgett, Contractor  Project Manager
PRC
Jamie VanBuskirk, Project  Coordinator,  U.S.  EPA Region 6
Cover Letter w/Enclosure
Submittal of "Quality Assurance  Project Plan"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002409  -  002411
09/10/91
003
W.J. Witt, Manager,  CERCLA Operations
Dow Chemical  Company
Jamie VanBuskirk,  Project Coordinator,  U.S. EPA Region 6
Correspondence w/Attachment
Progress  Report  for August 1991
                               22

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                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MUD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002412 - 002420
10/08/91
009
Greg Goodman, P.E., Project Manager
CH2M Hill
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Correspondence w/Attachments
Summary of results from 09/09-10/91 sampling - RI
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COM?ANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002421 - 002421
10/09/91
001
EPA Staff
U.S. EPA Region 6
U.S. EPA Region 6 Superfund Site File
Sign-in Sheet
Sign-in sheet for 10/09/91 meeting regarding Draft RI Report
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER Or PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002422 - 002422
10/10/91
001
Greg Goodman, P.E., Project Manager
CH2M Hill
Jamie VanBuskirk, Project Coordinator,
Correspondence
Notice of additional sampling  - RI
U.S. EPA Region 6
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002423 - 002426
10/10/91
004
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region  6
Correspondence w/Attachment
Progress Report for September  1991
                               23

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                  ADMINISTRATIVE RECORD INDEX
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
          DRAFT

D.L. MUD SUPERFUND SITE
LAD 981058019

002427 - 002431
10/28/91
005
Jamie VanBuskirk,  Project Coordinator
U.S. EPA Region 6
W.J. Witt, Manager,  CERCLA Operations,
Correspondence w/Attachment
Followup of 10/09/91 meeting about RI
                     Dow Chemical Company
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002432 - 002432
10/28/91
001
Greg Goodman, P.E.
CH2M Hill
Jamie VanBuskirk,
Correspondence
Notification to EPA that revised RI Report cannot be submitted
in accordance with Administrative Order on Consent, Section
VIII. 23. E
  Project Manager

Project Coordinator,
U.S. EPA Region 6
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002433 - 002439
11/11/91
007
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region  6
Correspondence w/Attachments
Progress Report for October 1991
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002440 - 002465
11/12/91
026
Nancy Fagan, Geologist
PRC
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region  6
Correspondence w/Attachments
Oversight activities from 10/24-29/91
                              24

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                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MUD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002466 - 002466
11/13/91
001
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
W.J. Witt, Manager, CERCLA Operations, Dow Chemical Company
Corre spondence
Followup on recent phone conversations between EPA and CH2M
Hill about additional work at the site
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002467  - 002168
11/20/91
002
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region  6
W.J. Witt, Manager, CERCLA Operations, Dow Chemical Company
Correspondence
EPA disapproves  of proposed work plan  for additional field
work submitted to EPA on 11/11/91
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002469  - 002471
11/21/91
003
Ann Schober
U.S. EPA Region  6
Jamie VanBuskirk,  Project Coordinator,  U.S.  EPA Region  6
ROC
Re: Gulf Coast Vacuum/D.L. Mud Sites  -  Adjacent canal sampling
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002472  -  002484
11/22/91
013
Greg Goodman,  P.E.,  Project  Manager
CH2M Hill
Jamie VanBuskirk,  Project  Coordinator,  U.S.  EPA Region 6
Correspondence w/Enclosure
Revised Work  Plan  for project  completion -  RI
                               25

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                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
D.L. MUD SUPERFUND SITE
LAD 981058019

002485 - 002497
11/29/91
013
Greg Goodman, P.E., Project Manager
CH2M Hill
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Correspondence w/Enclosure
Work Plan for completion of RI
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002498 - 002498
12/02/91
001
Brett Padgett, Contractor Project Manager
PRC
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Correspondence
PRC will conduct split-sampling activities from 12/03-08/91
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002499 - 002500
12/05/91
002
Joe Tieger
U.S. EPA
Regional Coordinators, U.S. EPA Regions 1-10
Memorandum w/Attachment
Re: Ecological Risk Assessments: Their Place  in  Records  of
Decision  (RODs) and Cost Documentation
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002501  - 002502
12/10/91
002
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Corporation
Jamie VanBuskirk,  Project Coordinator, U.S.  EPA Region 6
Correspondence w/Attachment
Progress report for November  1991
                               26

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                  ADMINISTRATIVE RECORD  INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MUD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002503 - 002505
12/16/91
003
Brett Padgett, Contractor Project Manager
PRC
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Corre spondence
Minutes to 10/09/91 Risk Assessment meeting
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER Or PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002506 - 002507
12/20/91
002
Greg Goodman, P.E., Project Manager
CH2M Hill
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region  6
Corre spondence
Request for data generated from EPA activities and  submission
of split sample data
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER CF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002508 - 002509
12/26/91
002
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
W.J. Witt, Manager, CERCLA Operations, Dow Chemical  Company
Correspondence
Confirmation of 01/15/92 meeting
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002510 - 002516
12/30/91
007
Nancy Pagan, PRC Geologist
PRC
Jamie VanBuskirk, Project Coordinator, U.S.  EPA Region 6
Correspondence w/Attachments
Re: 12/13/91 visual  inspection  of  canal
                              27

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                  ADMINISTRATIVE RECORD INDEX
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
          DRAFT

D.L. MUD SUPERFUND SITE
LAD 981058019

002517 - 002584
12/31/91
068
Unspecified
Unspecified
U.S. EPA Region 6 Superfund Site File
Guidance Documents
Miscellaneous guidance documents used in the selection of
remedy for D.L. Mud
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002585 - 002585
01/10/92
001
EPA Staff
U.S. EPA Region 6
Public
Superfund Site Update Fact Sheet
"Remedial Investigations Continue1
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002586 - 002587
01/15/92
002
EPA Staff
U.S. EPA Region 6
U.S. EPA Region 6 Superfund Site File
Meeting Agenda and Attachment
Agenda and sign-in list  for RI meeting
 DOCUMENT  NUMBER:
 DOCUMENT  DATE:
 NUMBER  OF PAGES:
 AUTHOR:
 COMPANY/AGENCY:
 RECIPIENT:
 DOCUMENT  TYPE:
 DOCUMENT  TITLE:
 002588  - 002592
 01/15/92
 005
 EPA  Staff
 U.S.  EPA Region  6
 U.S.  EPA Region  6 Superfund Site  File
 Meeting Minutes
 Minutes to PRP meeting
                               28

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                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 D.L.  MUD SUPERFUND  SITE
 LAD  981058019

 002593  - 002595
 02/10/92
 003
 W.J.  Witt,  Manager,  CERCLA Operations
 Dow  Chemical Company
 Jamie VanBuskirk, Project  Coordinator,
 Correspondence w/Attachment
 Progress Report  for January 1992
U.S. EPA Region 6
DOCUMENT NUMBER:
DOCUMENT DATE :
NUMBER OF PAGES:
AUTHOR:
COM?ANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 002596  -  002599
 02/21/92
 004
 Greg  Goodman.  P.E.,  Project Manager
 CH2M  Hill
 Jamie VanBuskirk,  Project Coordinator,
 Fax Transmittal  w/Attachment
 Re: Sampling data
U.S. EPA Region 6
DOCUMENT NUMBER:
DOCUMENT DATE:
NTOBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 002SOO  -  002607
'02/21/92
 008
 Tom  Nelson
 Sverdrup  Corporation
 Jamie VanBuskirk,  Project Coordinator, U.S. EPA Region 6
 Facsimilie Transmittal w/Attachment
 Re:  Sampling data from Gulf Coast Vacuum
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
 002608 -  002608
 02/25/92
 001
 Garret Bondy,  Chief,  AR/LA Superfund Enforcement Section
 U.S.  EPA Region 6
 Don  Draper,  Director,  Technical Support Center, Robert S. Kerr
 Research Laboratory,  U.S. EPA
 Memorandum
 Request for technical support
                               29

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SITE NAME:
SITE NUMBER:
ADMINISTRATIVE RECORD INDEX

           DRAFT

 D.L. MUD SUPERFUND SITE
 LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY /AGENCY :
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 002609 - 002615
 02/25/92
 007
 Jamie VanBuskirk, Project Coordinator
 U.S. EPA Region 6
 W.J. Witt, Manager, CERCLA Operations, Dow Chemical Company
 Correspondence
 Summary of discussions held between Dow Chemical Company and
 EPA during 01/15/92 meeting
DOCUMENT ^NUMBER:
DOCUMENT ~DATE:
NUMBER OF PAGES::
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 002616 - 002620
 02/25/92
 005
 "Jamie VanBuskirJfrr^roject Coordinator
 U.s7^EEAR»glon 6
 W.J.  Witft>vNManager, CERCLA Operations, Dow Chemical Company
 C     .        ^
                   ^ions held between Dow Chemical Company and
            01/15/92'Xeeting
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER 0? PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 002621 - 002758
 02/28/92
 138
 Brett Padgett, Contractor Project Manager
 PRC
 Jamie VanBuskirk, Project Coordinator,  U.S.  EPA Region 6
 Cover Letter w/Enclosure
 Submittal of "Field Oversight  Report"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 002759  -  002761
 02/29/92
 003
 W.J. Witt, Manager,  CERCLA Operations
 Dow Chemical Company
 Jamie VanBuskirk,  Project  Coordinator,  U.S.  EPA Region 6
 Correspondence
 Summary of 01/15/92  meeting -  RI issues
                               30

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                  ADMINISTRATIVE  RECORD  INDEX
                              DRAFT
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
D.L. MUD SUPERFUND SITE
LAD 981058019

002762 - 002780
03/02/92
019
Carl Hicham, R.S., Senior Regional Representative
Agency for Toxic Substances and Disease Registry - Region 6
Allyn M. Davis, Director, Hazardous Waste Management Division,
U.S. EPA Region 6
Correspondence w/Attachment
"Interim Preliminary Health Assessment"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002781 - 002781
03/05/92
001
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
W.J. Witt, Manager, CERCLA Operations, Dow Chemical Company
Correspondence w/o Attachment
Procedure for calculating agricultural portion of residential
exposure scenario as discussed in 01/15/92 meeting and EPA's
02/25/92 letter
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002782 - 002884
03/06/92
103
Greg Goodman, P.E., Project Manager
CH2M Hill
Jamie VanBuskirk,  Project Coordinator, U.S. EPA Region  6
Correspondence w/Enclosure
Data submittal and request for verification of inclusion of
EPA samples
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002885 - 002887
03/10/92
003
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk,  Project Coordinator, U.S.  EPA Region 6
Correspondence w/Attachment
Progress Report for February  1992
                               31

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                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MOD SUPERFDND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002888 - 002888
03/17/92
001
Jamie VanBuskirk,  Project Coordinator
U.S. EPA Region 6
U.S. EPA Region 6  Superfund Site File
ROC
Re: Phone conversation with David Price (CH2M Hill) about
collection of additional samples at empty drum area and for
barium specification
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002889 - 002892
03/19/92
004
Harold Underwood
CH2M Hill
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Fax Transmittal w/Attachment
Notice that Dow Chemical Company plans to collect additional
samples to investigate barium sulfate in soils and drum found
in onsite canal
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002893 - 002893
03/24/92
001
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
W.J. Witt, Manager, CERCLA Operations, Dow  Chemical  Company
Corre spondence
Acknowledgment of written notice  from CH2M  Hill  about proposal
to collect additional samples on  03/20/92
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF  PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002894  - 002894
03/30/92
001
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator,  U.S.  EPA Region 6
Corre spondence
Request for copy of Gulf Coast  Vacuum  RI  Report
                               32

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                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
D.L. MUD SUPERFUND SITE
LAD 981058019

002895 - 002897
04/10/92
003
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator,
Correspondence w/Attachment
Progress Raport for March 1992
U.S. EPA Region 6
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002898 - 002908
04/15/92
Oil
Nancy Pagan, Geologist
PRC
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Correspondence and Attachment
Split-sampling and oversight visit
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002909 - 002909
04/16/92
001
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region  6
Corre spondence
Oral notice given by CH2M Hill on  03/10/92  to EPA Region  6  and
on 03/11/92 to EPA's contractor  (as directed by EPA)  about
planned collection of additional samples
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002910  - 002910
04/23/92
001
Brett Padgett, Contractor  Project Manager
PRC
Jamie VanBuskirk, Project  Coordinator,  U.S.  EPA Region 6
Correspondence
Split sample data review
                               33

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                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
D.L. MUD SUPERFUND SITE
LAD 981058019

002911 - 002914
05/11/92
004
Nancy Fagan, Geologist
PRC
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Correspondence
Minutes to 05/07/92 Risk Assessment meeting
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002915  - 002917
05/11/92
003
W.j. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator,
Correspondence w/Attachment
Progress Report for April 1992
U.S. EPA Region 6
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002918  -  002924
05/12/92
007
Wanda Hall, Data Package Supervisor
CH2M Hill
Greg Goodman,  P.E., Project Manager,  CH2M Hill
Correspondence w/Enclosures
Re: Analytical data - LMG  Laboratory No.  21501
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002925  -  002932
05/14/92
008
Ghassan Khoury,  Regional Toxicologist
U.S.  EPA Region  6
Jamie VanBuskirk, Project  Coordinator,  U.S.  EPA Region 6
Memorandum
Re: Values of variables in intake equation for different
exposure routes  to  be  used in Risk Assessment
                               34

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                  ADMINISTRATIVE RECORD INDEX

                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MUD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002933 - 002937
05/15/92
005
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator,
Correspondence
Summary of 05/07/92 meeting  - RI
U.S. EPA Region 6
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002938 - 002942
05/15/92
005
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator, U.S.  EPA Region 6
Correspondence
Summary of 05/07/92 meeting  - RI
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002943 - 002944
06/01/92
002
Greg Goodman, P.E.,  Project Manager
CH2M Hill
Jamie VanBuskirk,  Project  Coordinator,  U.S.  EPA Region 6
Correspondence
Schedule for completion  of RI
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002945 - 002946
06/03/92
002
W.J. Witt, Manager,  CERCLA Operations
Dow Chemical  Company
Jamie VanBuskirk,  Project  Coordinator,  U.S.  EPA Region 6
Correspondence w/Attachment
Information request  from Gulf  Coast Vacuum Site -  D.L. Mud
Site RI
                               35

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                  ADMINISTRATIVE RECORD INDEX
SITE NAME:
SITE NUMBER:
          DRAFT

D.L. MOD SDPERFOND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:

COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002947 - 002953
06/03/92
007
Terry O'Bryan, Chemical Assessment Desk,  Office of Pollution
Prevention and Toxics
U.S. EPA - Washington, D.C.
Ghassan Khoury, Regional Toxicologist,  U.S.  EPA Region 6
Memorandum w/Attachment
Re: Bioavailability of barium sulfate
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002954 - 002954
06/03/92
001
Ghassan Khoury, Regional Toxicologist
U.S. EPA Region 6
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Memorandum
Re: Surface soil and sediment data
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
002955 - 002963
06/08/92
009
Anthony Gardner, Regional TES 9 Manager
PRC
Karen Hartis, CERCLA Regional Project Officer, Superfund
Management Branch, U.S. EPA Region 6
Cover Letter w/Attachment
Revised Work Plan for RI/FS Technical Oversight  (Cost
documentation contained in the work plan is "Business
Confidential and is not included.  See "Special Note to the
Reader")
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
002964  - 002967
06/08/92
004
Anthony Gardner, Regional TES 9 Manager
PRC
Karen Hartis, CERCLA Regional Project Officer, Superfund
Management Branch, U.S. EPA Region 6
Cover Letter w/Attachment
Revised Work Plan for RI/FS Technical Oversight  (Cost
documentation contained in the work plan is  "Business
Confidential" and is not included.  See "Special Note  to  the
Reader")
                               36

-------
                  ADMINISTRATIVE RECORD INDEX
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
          DRAFT

D.L. MUD SUPERFUND SITE
LAD 981058019

002958 - 002970
06/10/92
003
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator,
Correspondence w/Attachment
Progress Report for May 1992
         U.S. EPA Region  6
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002971 - 002976
06/24/92
006
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
W.J. Witt, Manager, CERCLA Operations, Dow Chemical Company
Correspondence w/Attachments
Re: 1) Further investigative activities regarding former
impoundments needed and 2) future schedule of RI/FS
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002977 - 002977
06/29/92
001
Tom Nelson
Sverdrup Corporation
Ann Schober, U.S. EPA Region
Technical Memorandum
Historical aerial photograph
and D.L. Mud Superfund Sites
(02/17/74)  of  Gulf Coast Vacuum
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002978 - 002980
07/01/92
003
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator, U.S.  EPA Region 6
Corre spondence
Response to 06/25/92 EPA letter
                              37

-------
                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MUD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002981 - 002983
07/10/92
003
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator,
Cover Letter w/Attachment
Progress report for June 1992
U.S. EPA Region 6
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002984 - 002985
07/10/92
002
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Corre spondence
Response to EPA's 07/01/92 letter
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002986  - 002993
07/17/92
008
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator,  U.S.  EPA Region  6
Correspondence w/Attachment
Work Plan for additional EPA requested investigation  and
response to EPA's 06/25/92 letter
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002994  -  002995
07/28/92
002
Jamie VanBuskirk,  Project  Coordinator
U.S. EPA  Region  6
W.J. Witt,  Manager, CERCLA Operations,  Dow Chemical Company
Correspondence
Comments  on proposed  Work  Plan revision
                               38

-------
                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MOD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
00299S - 002996
07/29/92
001
David Price
CH2M Hill.
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Cover Letter w/o Enclosure
Former impoundment structure area map
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002997 - 002997
08/10/92
001
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
U.S. EPA Region 6 Superfund Site File
ROC
Phone conversation with CH2M Hill and Dow Chemical regarding
health effects assessment summary tables
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMP ANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
002998 - 003000
08/10/92
003
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region  6
Cover Letter w/Attachment
Progress report for July 1992
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
003001  - 003002
08/12/92
002
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region  6
W.J. Witt, Manager, CERCLA Operations, Dow Chemical  Company
Correspondence w/o Attachment
Risk assessment  issues
                               39

-------
                  ADMINISTRATIVE RECORD INDEX
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
          DRAFT

D.L. MUD SUPERFUND SITE
LAD 981058019

003003 - 003006
08/17/92
004
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Correspondence w/Attachment
Revised Work Plan for additional EPA requested investigation
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
003007 - 003007
08/27/92
001
Jamie VanBuskirk,
U.S. EPA Region 6
W.J. Witt, Manager,
Correspondence
Formal approval of revised Work Plan for additional trenching
investigation
Project Coordinator

  CERCLA Operations, Dow Chemical Company
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
003008 - 003010
09/10/92
003
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region  6
Cover Letter w/Attachment
Progress report for August 1992
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
003011  - 003014
09/11/92
004
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk,  Project  Coordinator,  U.S.  EPA Region 6
Correspondence w/o Attachments
Response to 08/12/92  and 08/27/92  EPA  letters
                               40

-------
                   ADMINISTRATIVE  RECORD  INDEX
                              DRAFT
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
D.L. MUD SUPERFUND SITE
LAD 931058019

003015  - 003015
09/22/92
001
Ghassan Khoury, Regional Toxicclogist
U.S. EPA Region 6
Jamie VanBuskirk, Project Coordinator,
Memorandum
Re.: Bioavailability of barium sulfate
U.S. EPA Region 6
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
003016  - 003017
10/15/92
002
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Corre spondence
Resolution of outstanding risk assessment issues
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
003018  - 003048
10/20/92
031
Ghassan Khoury, Regional Toxicologist
U.S. EPA Region 6
Joan Dollarhide, Office of Research and Development, U.S.
- Cincinnati, OH
Memorandum w/Attachment
Bioavailability of barium sulfate
                   EPA
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
003049 - 003061
10/20/92
013
Ghassan Khoury, Regional Toxicologist
U.S. EPA Region 6
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Memorandum w/Attachments
Re: Response to D.L. Mud letter "Resolution of Outstanding
Risk Assessment Issues"
                              41

-------
                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
D.L. MUD SUPERFUND SITE
LAD 981058019

003052 - 003085
10/23/92
024
Mark Ezell, Environmental Scientist
PRC Environmental Management, Inc. (PRO
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Correspondence w/Attachments
Re: 08/31/92 - 09/01/92 site visit to perform split sampling
and oversight of sampling activities
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
003086 - 003087
10/23/92
002
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
W.J. Witt, Manager, CERCLA Operations, Dow  Chemical  Company
Correspondence
Re: Risk Assessment
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
003088  - 003093
11/10/92
006
Nancy Fagan, Contractor Project Manager
PRC
Jamie VanBuskirk, Project Coordinator, U.S.  EPA Region 6
Correspondence w/Enclosure
"D.L. Mud Former Pit Area Sample Data  Differences"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
003094  -  003152
11/10/92
059
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk,  Project  Coordinator,
Cover Letter w/Attachment
Progress  report  for October 1992
U.S. EPA Region 6

-------
                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
D.L. MUD  SUPERFUND  SITE
LAD 981058019

003153  -  003153
11/23/92
001
Greg Goodman,  P.E.,  Project  Manager
CH2M Hill
Jamie VanBuskirk, Project Coordinator,  U.S.  EPA Region 6
Corre sp ondence
Submission  of  RI  Report
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
003154  -  003160
11/29/92
007
Joan Dollarhide,  Office  of  Research  and Development
U.S. EPA  -  Cincinnati, OH
Ghasson Khoury,  Regional Toxicologist,  U.S.  EPA Region 6
Memorandum  w/Attachment
Evaluation  of  barium desorption pilot  study  and the relevance
of desorption  study to barium risk assessment
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
'003161  -  003354
 12/07/92
 204
 Greg Goodman,  P.E.,  Project Manager
 CH2M Hill
 U.S. EPA  Region  6  Superfund Site  File
 Cover Letter w/Report
 RI Report
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER 0? PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 003365  -  003650
 12/07/92
 286
 Greg Goodman,  P.E.,  Project Manager
 CH2M Hill
 U.S. EPA  Region  6  Superfund Site  File
 Appendixes
 RI Report -  Appendixes A-G
                              43

-------
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
ADMINISTRATIVE RECORD INDEX

           DRAFT

 D.L. MUD SUPERFUND SITE
 LAD 981058019

 003651 - 004104
 12/07/92
 454
 Greg Goodman, P.E., Project Manager
 CH2M Hill
 U.S. EPA Region 6 Superfund Site File
 Appendix
 RI Report - Appendix H
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 004105 - 004594
 12/07/92
 490
 Greg Goodman, P.E., Project Manager
 CH2M Hill
 U.S. EPA Region 6 Superfund Site File
 Appendixes
 RI Report - Appendixes I-K
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 004595 - 004597
 12/10/92
 003
 W.J. Witt, Manager, CERCLA Operations
 Dow Chemical Company
 Jamie VanBuskirk, Project Coordinator, U.S. EPA Region  6
 Cover Letter w/Attachment
 Progress report for November 1992
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 004598 - 004601
 01/05/93
 004
 Greg Goodman, P.E., Project Manager
 CH2M Hill
 Jamie VanBuskirk, Project Coordinator, U.S. EPA  Region 6
 Facsimile Transmittal w/Attachments
 Re: Subchronic toxicity of barium  chloride
                               44

-------
                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MUD SUPERFDND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
004602  - 004602
01/11/93
001
Ghassan Khoury, Regional Toxicologist
U.S. EPA Region 6
Joan Dollarhide, Office of Research and Development, U.S. EPA
- Cincinnati, OH
Memorandum
Impact of the new study on the chronic and subchronic toxicity
values of barium
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004603 - 004604
01/11/93
002
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Cover Letter w/Attachment
Progress report for December 1992
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004605  - 004609
01/22/93
005
Dennis  W. Shelton, Toxicologist
CH2M Hill
W.J. Witt, Manager, CERCIA Operations,  Dow  Chemical  Company
Corre spondence
Development of a  subchronic oral  reference  dose value  (RfD)
for barium
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004610  - 004615
01/26/93
006
W.J. Witt, Manager, CERCLA  Operations
Dow  Chemical Company
Jamie VanBuskirk,  Project Coordinator,  U.S.  EPA Region 6
Cover Letter w/Attachment
Development of a  subchronic oral  RfD value  for barium
                               45

-------
SITE NAME:
SITE NUMBER:
ADMINISTRATIVE RECORD INDEX

           DRAFT

 D.L. MUD SUPERFUND SITE
 LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
 004616 - 004616
 01/26/93
 001
 Jamie VanBuskirk, Project Coordinator
 U.S. EPA Region 6
 Harold Ethridge, Louisiana Department of Environmental Quality
 (LDEQ)
 Cover Letter w/o Enclosures
 Draft F$ Report - Pab Oil and RI Report - D.L. Mud
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 004617 - 004625
 02/03/93
 009
 Joan Dollarhide, Office of Research and Development
 U.S. EPA - Cincinnati, OH
 Ghassan Khoury, Regional Toxicologist, U.S. EPA Region 6
 Memorandum w/Attachment
 Review of the Dietz et al.  (1992) Study for RfD for Barium
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 004626 - 004627
 02/10/93
 002
 W.J. Witt, Manager, CERCLA Operations
 Dow Chemical Company
 Jamie VanBuskirk, Project Coordinator, U.S.  EPA Region  6
 Cover Letter w/Attachment
 Progress report for January  1993
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 004628  - 004628
 02/16/93
 001
 Ghassan Khoury, Regional Toxicologist
 U.S. EPA Region 6
 U.S. EPA Region 6 Superfund  Site  File
 ROC
 Phone conference with Lynn Papa  (U.S. EPA -  Cincinnati,  OH)
 about subchronic RfD toxicity value for barium
                              46

-------
                  ADMINISTRATIVE RECORD INDEX

                             DRAFT
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
D.L. MUD SUPER'FUND SITE
LAD 931058019

004629  - 004629
02/16/93
001
Ghassan Khoury, Regional Toxicologist
U.S. EPA Region 6
U.S. EPA Region 6 Superfund Site File
ROC
Subchronic RfD toxicity value for Barium
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004630  - 004630
03/01/93
001
Debra McKean
PRC
Nancy Fagan, Contractor Project Manager,
Facsimilie Transmittal
Requested barium numbers
PRC
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004631  - 004632
03/05/93
002
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
W.J. Witt, Manager, CERCLA Operations, Dow Chemical Company
Corre spondence
Formal  approval of RI Report subject to comments  contained in
letter
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004633  - 004633
03/08/93
001
Brent Schindler, Attorney
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region  6
Corre spondence
Freedom of Information Act request for EPA Region  6 and EPA
Cincinnati, OH documents dated post-12/08/92 about toxicity
evaluation for barium
                              47

-------
                  ADMINISTRATIVE RECORD INDEX

                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MUD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004634 - 004635
03/10/93
002
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Cover Letter w/Attachment
Progress report for February 1993
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004636 - 004636
03/19/93
001
W.J. Witt,  Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Correspondence
Response to EPA's comments outlined in 03/09/93 letter
regarding RI Report
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
004637 - 004638
03/26/93
002
Don Williams, Chief, Texas Superfund Remediation Section
U.S. EPA Region 6
Joan Dollarhide, Office of Research and Development,  U.S.
- Cincinnati, OH
Memorandum
Evaluation of Subchronic RfD  for Barium
EPA
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004639  - 004644
04/01/93
006
CH2M Hill Staff
CH2M Hill
Jamie VanBuskirk, Project  Coordinator,  U.S.  EPA Region 6
Meeting Agenda and Attachments
"FS Options Meeting"
                              48

-------
                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MUD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004645 - 004646
04/05/93
002
Nancy Pagan, Contractor Project Manager
PRC
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Memorandum
Minutes to 04/01/93 meeting with Dow Chemical and CH2M Hill
about proposed FS
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:  '
DOCUMENT TYPE:
DOCUMENT TITLE:
004647 - 004647
04/07/93
001
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
U.S. EPA Region 6 Superfund Site File
ROC
Phone conference between EPA Region 6,
Dow Chemical Company,
                   and CH2M Hill as followup to  04/01/93 meeting
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004648  - 004649
04/07/93
002
Joe Winkle, Regional Administrator
U.S. EPA Region 6
Bill Luthans, Superfund Enforcement  Section, U.S. EPA Region  6
Memorandum
Re: Lifting Recusal from Involvement in Pab Oil  and D.L. Mud
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004650  - 004652
04/12/93
003
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator,  U.S.  EPA Region  6
Cover Letter w/Attachment
Progress report for March 1993
                               49

-------
                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MUD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004653 - 004654
04/12/93
002
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
W.J. Witt, Manager, CERCLA Operations, Dow Chemical Company
Corre epondence
Re: 1) Followup on 04/01/93 meeting and 04/07/93 phone
conversation about conductance of FS and 2) extension of due
date for submittal of FS Work Plan until 04/23/93
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004655 - 004668
04/23/93
014
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator,
Cover Letter w/Attachment
Draft FS Work Plan
U.S. EPA Region 6
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004669  - 004671
04/28/93
003
Greg Goodman, P.E. Project Manager
CH2M Hill
Jamie VanBuskirk, Project Coordinator,  U.S.  EPA Region 6
Facsimile Cover Sheet and Attachments
Re: Barium  toxicological profiles
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
004672  -  004673
04/29/93
002
Brent Schindler, Attorney
Dow Chemical  Company
Nellie  Shirer, Office  of  Regional  Counsel (ORC),  U.S. EPA
Region  6
Correspondence
Comments  regarding draft  Administrative Order on Consent
                               50

-------
                  ADMINISTRATIVE RECORD INDEX

                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MUD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004674 - 004691
04/30/93
018
William Ripley, Certified Petroleum Geologist
Consultant
U.S. EPA Region 6 Superfund Site Files
Report
Investigation of barium as a trace element
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004692 - 004695
05/06/93
004
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
W.J. Witt, Manager, CERCLA Operations, Dow  Chemical Company
Correspondence
Formal disapproval of the draft FS Work Plan
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004696 - 004698
05/10/93
003
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator, U.S.  EPA Region 6
Cover Letter w/Attachment
Progress report for April 1993
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
004699 - 004699
05/14/93
001
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region  6
Harold Ethridge, Administrator,  Inactive  and Abandoned Sites
Division, LDEQ
Cover Letter w/o Enclosures
Additional  information  relating  to  investigation of former
impoundment area found  at the  site
                               51

-------
                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MOD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004700 - 004700
05/14/93
001
Ghassan Khoury, Regional Toxicologist
U.S. EPA Region 6
Jamie VanBuskirk, Project Coordinator,
Memorandum
Risk Assessment TICs Evaluation
U.S. EPA Region 6
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
004701 - 004716
05/19/93
016
Gary Diamond and Elena Mantis-Mercader
Syracuse Research Corporation
Joan Dollarhide, Office of Research and Development, U.S. EPA
- Cincinnati, OH
Memorandum w/Attachment
Review of Subchronic and Chronic RfDs for Barium
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004717 - 004733
05/28/93
017
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Correspondence w/Attachment
Revised FS Work Plan
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF  PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 004734  - 004734
 06/09/93
 001
 Jamie VanBuskirk, Project  Coordinator
 U.S. EPA Region  6
 U.S. EPA Region  6 Superfund Site File
 ROC
 Phone conversation with W.J.  Witt (Dow Chemical
 regarding  FS Work Plan
          Company)
                               52

-------
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
ADMINISTRATIVE RECORD INDEX

           DRAFT

 D.L. MUD SUPERFUND SITE
 LAD 981058019

 004735 - 004736
 06/10/93
 002
 W.J. Witt, Manager, CERCLA Operations
 Dow Chemical Company
 James VanBuskirk, Project Coordinator,
 Cover Letter w/Attachment
 Progress report for May 1993
U.S. EPA Region 6
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 004737 - 004738
 06/18/93
 002
 John Rauscher, Regional Toxicologist
 U.S. EPA Region 6
 Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
 Memorandum
 Central tendency exposure and reasonable maxium exposure soil
 ingestion rate for residential child  scenario used in RI
 Report
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 004739 - 004742
 06/18/93
 004
 Jamie VanBuskirk, Project Coordinator
 U.S. EPA Region 6
 W.J. Witt, Manager, CERCLA Operations, Dow Chemical Company
 Correspondence
 EPA disapproves the revised FS Work Plan dated 05/28/93
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 004743 - 004758
 06/25/93
 016
 Greg Goodman, P.E., Project Manager
 CH2M Hill
 Jamie VanBuskirk, Project Coordinator, U.S.  EPA  Region  6
 Fascimile Cover Sheet and Attachment
 Proposed rule exempting barium sulfate from  toxic  chemical
 reporting requirements
                              53

-------
                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MUD SDPERFUND SITE
LAD 991058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004759 - 004759
05/28/93
001
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
U.S. EPA Region 6 Superfund Site File
Meeting Agenda
"D.L. Mud FS Work Plan Meeting"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004760 - 004773
06/30/93
014
Greg Goodman, P.E., Project Manager
CH2M Hill
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Cover Letter w/Enclosure
Revised FS Work Plan
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004774  - 004774
07/09/93
001
Jamie VanBuskirk, Project Manager
U.S. EPA Region 6
W.J. Witt, Manager, CERCLA Operations,  Dow Chemical Company
Correspondence
EPA formally approves FS Work  Plan
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
004775  -  004794
07/23/93
020
Don Williams
U.S. EPA  Region  6
Joan Dollarhide, Office  of  Research and Development,  U.S.  EPA
- Cincinnati,  OH
Memorandum w/Attachments
Review  of Subchronic  and Chronic RfDs for Barium
                               54

-------
                  ADMINISTRATIVE  RECORD  INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MOD  SUPERFUND SITE
LAD  981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
 004795  -  004796
 08/10/93
 002
 W.J. Witt,  Manager,  CERCLA Operations
 Dow Chemical  Company
 Jamie VanBuskirk,  Project  Coordinator,  U.S.  EPA Region 6
 Cover Letter  w/Attachment
 Progress  report  for  July 1993
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004797  -  004834
08/11/93
038
Greg Goodman,'P.E.,  Project Manager
CH2M Hill
Jamie VanBuskirk,  Project  Coordinator,  U.S.  EPA Region 6
Cover Letter  and Enclosure
"Final  Screening Results Memorandum  - D.L. Mud Site FS"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004835  -  004836
•08/24/93
002
Jamie VanBuskirk,  Project  Coordinator
U.S. EPA  Region  6
W.J. Witt, Manager,  CERCLA Operations,  Dow Chemical Company
Corre spondence
Submittal of  EPA comments  on  "Final  Screening Results
Memorandum -  FS"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:

COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004837  -  004840
08/27/93
004
Joan Dollarhide, Associate  Director,  Office of Research and
Development
U.S. EPA  - Cincinnati,  OH
Jamie VanBuskirk,  Project Coordinator,  U.S. EPA Region 6
Memorandum and Attachment
Review  of Subchronic  and Chronic  RfDs for Barium
                              55

-------
                  ADMINISTRATIVE RECORD INDEX
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
          DRAFT

D.L. MUD SUPERFUND SITE
LAD 981058019

004841 - 004842
09/10/93
002
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
James VanBuskirk, Project Coordinator,
Cover Letter w/Attachment
Progress report for August 1993
U.S. EPA Region 6
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
004843 - 004844
09/13/93
002
Linda Papa, Office of Research and Development
U.S. EPA - Cincinnati, OH
Joan Dollarhide, Office of Research and Development, U.S. EPA
- Cincinnati,  OH
Memorandum
Review of Subchronic/Chronic RfD for Barium
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004845 - 004848
09/14/93
004
Joan Dollarhide, Office of Research and Development
U.S. EPA - Cincinnati, OH
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region  6
Memorandum w/Attachment
Review of Subchronic and Chronic RfDs  for Barium
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004849  - 004849
09/29/93
001
Greg Goodman, P.E., Project Manager
CH2M Hill
Jamie VanBuskirk,  Project  Coordinator,  U.S.  EPA Region 6
Cover Letter w/o Attachment
Re: Draft FS Report
                              56

-------
                  ADMINISTRATIVE  RECORD INDEX

                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MOD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004850 - 004850
10/20/93
001
Kaplan Herald Staff Writer
The Kaplan Herald
Public
Notice
Re: 1) Record of Decision for Pab Oil and 2)' Pab Oil and D.L.
Mud Superfund Sites Open House - 10/26/93
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
004851 - 004851
10/21/93
001
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
Tim Knight, Administrator, Inactive and Abandoned Sites
Division, LDEQ
Corre spondence
EPA requests LDEQ's assistance and participation in preparing
the ROD
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF FACES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004852 - 004852
10/24/93
001
Abbeville Meridional Staff Writer
Abbeville Meridional
Public
Notice
Open House for Pab Oil and D.L. Mud  - 10/26/93
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004853 - 004853
10/26/93
001
EPA Staff
U.S. EPA Region 6
Public
Sign-In List
Sign-In List for 10/26/93 Open House for Pab Oil  and D.L.  Mud
                              57

-------
                  ADMINISTRATIVE RECORD INDEX
SITE NAME:
SITE NUMBER:

DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
          DRAFT

D.L. MUD SUPERFUND SITE
LAD 981058019

004854 - 004855
10/27/93
002
Felicia Dugas, Staff Writer
Abbeville Meridional
Public
Newspaper Article
"Pab Oil site remedy, D.L. Mud discussed"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004856 - 004856
10/27/93
001
Janice Macomber, Acadiana Correspondent
Advertiser
Public
Newspaper Article
"Superfund cleanup plan presented for  Pab site"
RAX a el)
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004857  -  004857
10/27/93
001
Acadiana  Bureau Staff Writer
The Adocate
Public
Newspaper Article
"Superfund site cleanup may take  4  years"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:

COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004858  -  004858
10/27/93
001
Tim Knight, Administrator,  Inactive  and Abandoned Sites
Division
LDEQ
Jamie VanBuskirk,  Project  Coordinator,  U.S. EPA Region 6
Corre spondence
LDEQ comments on  FS Report
                               58

-------
                  ADMINISTRATIVE RECORD INDEX

                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MUD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMP ANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004859 - 004865
11/04/93
007
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
W.J. Witt, Manager, CERCLA Operations, Dow Chemical Company
Correspondence
EPA comments on the Draft FS Report
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004866 - 004874
11/10/93
009
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator,
Cover Letter w/Attachment
Progress report for October 1993
U.S. EPA Region 6
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004875 - 004877
11/10/93
003
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk,  Project Coordinator,
Cover Letter w/Attachment
Progress report for October 1993
U.S. EPA Region 6
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMP ANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004878  - 004901
11/10/93
024
Terry 0'Bryan, Chemical  Screening and Risk Assessment  Division
U.S. EPA - Washington, D.C.
Ghassan Khoury,  Regional Toxicologist, U.S. EPA Region 6
Memorandum and Attachments
Re: 1) Request for  structure-activity estimates and 2)  1989
"Structural Activity  Relationships  of Alkanes  and Alkenes
Report"
                              59

-------
                  ADMINISTRATIVE RECORD INDEX
                             DRAFT
SITE NAME:
SITE NUMBER:
D.L. MUD SUPERFUND SITE
LAD 981058019
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:

DOCUMENT TYPE:
DOCUMENT TITLE:
004902 - 004909
11/15/93
008
Jamie VanBuskirk, Project Coordinator
U.S. EPA Region 6
Joan Dollarhide, Office of Research and Development,  U.S.  EPA
- Cincinnati, OH
Fascimile Cover Sheet and Attachments
Re: 1} 10/93 October progress report and 2)  Memorandum "Review
of the Subchronic RfD for Barium"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004910 - 004911
12/10/93
002
EPA Staff
U.S. EPA Region 6
Public
Site Update Fact Sheet
"Site Investigation Completed"
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004912 - 004914
12/10/93
003
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator, U.S. EPA Region 6
Cover Letter w/Attachment
Progress report for November 1993
DOCUMENT NUMBER:
DOCUMENT DATE:
NUMBER OF PAGES:
AUTHOR:
COMPANY/AGENCY:
RECIPIENT:
DOCUMENT TYPE:
DOCUMENT TITLE:
004915 - 004917
01/10/94
003
W.J. Witt, Manager, CERCLA Operations
Dow Chemical Company
Jamie VanBuskirk, Project Coordinator,
Cover Letter w/Attachment
Progress report for December 1993
U.S. EPA Region 6
                               60

-------
                  Appendix #3

STATE OF LOUISIANA LETTER DF CONCURRENCE  ON THE
SELECTED REMEDY

-------

-------
                          State of Louisiana
                    Department of Environmental Quality
 Edwin W. Edwards
     Governor
                              September  1,  1994
                                                           William A. Kucharski
                                                               Secretary
                                                                   o
Jamie VanBuskirk
Remedial Project Manager  (6H-EA)
Region VI
U.S. Environmental Protection Agency
Dallas, TX  75202-2733

RE:  Draft  Record of Decision D.L.  Mud Superfund Site

Dear Mr. VanBuskirk:

Personnel  of the Louisiana  Department of  Environmental  Quality
Inactive and Abandoned  Sites Division  (LDEQ/IASD)  have  completed
their review of the Draft  Record of  Decision dated August 12, 1994.

We are in agreement with the selected remedial actions for the D.L.
Mud, Inc. Superfund Site and have no further comments on the Draft
Record of Decision.

If you have  any  further  questions, please contact Mr. Rich Johnson
of this office  at (504)  765-0487.

                               Sincerely.
                                    Tim B.  Knight
                                    Administrator
     TBK:RJ:j1
OFFICE OF LEGAL AFFAIRS AND ENFORCEMENT
INACTIVE AND ABANDONED SITES DIVISION  P.O. BOX 82282

 TELEPHONE (504) 765-0487  FAX (504) 765-0484

    AN EQUAL OPPORTUNITY EMPLOYER
                                                      BATON ROUGE, LOUISIANA 70884-2282

-------
                          State of Louisiana
                    Department of Environmental Quality
                                                                 'f/, i «•« h I. I.'' ''
 Edwin W. Edwards
     Governor
       May 6, 1994
William A. Kucharski
     Secretary
    Jamie  VanBuskirk
    Remedial  Project Manager (6H-EA)
    U.S. Environmental Protection Agency
    1445 Ross Ave.  Suite 1200
    Dallas, TX 7502-2733

    RE:  Proposed Plan of Action for D.L. Mud
         Superfund Site, Vermilion Parish Louisiana

    Dear Mr.  VanBuskirk:

    Personnel of the Louisiana Department of Environmental Quality
     (LDEQ)  have completed their review  of the Proposed Plan of Action
    for the D.L. Mud Superfund Site in Abbeville Louisiana, received on
    April  29, 1994.

    We  support  the preferred  alternatives  for  addressing  the site
    contaminants which  will meet the  primary remedial  objectives by
    combining Alternative  #2 and Alternative #6.  These alternatives
    will  provide  for institutional  controls  and the  excavation and
    offsite disposal of contaminated subsurface soils.

    If you have any questions,  please contact Mr. Rich Johnson of this
    office at (504) 765-0487.

                                   Sincerely,
                                    Tim B.  Knight
                                    Administrator
                                    Inactive and Abandoned Sites Division
     TBK:RJ:
OFFICE OF LEGAL AFFAIRS AND ENFORCEMENT
INACTIVE AND ABANDONED SITES DIVISION  P.O BOX 82282  BATON ROUGE. LOUISIANA 70884-2282

 TELEPHONE (504) 765-0487  FAX (504) 765-0484

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            Appendix  #4




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              Appendix #5

JUNE  27,  1994 MEMO FROM  ECAO REGARDING
SUBCHRONIC AND CHRONIC RfD FOR BARIUM

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         UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

                 OFFICE OF RESEARCH AND DEVELOPMENT    .. '. •'•_

              ENVIRONMENTAL CRITERIA AND ASSESSMENT OFFICE '
                          CINCINNATI. OHIO 45268
MEMORANDUM

DATES

SUBJECT:


FROM:




TO:
                                                  ""--  -'I'L -5  pi!  2- I;
                                                  £-vi:.~L::.j ERA?:CH
June 27, 1994

Review of Subchronic and  Chronic  RfDs for Barium
(D.L. Mud Inc., LA)
Joan S. Dollarhide
Director
Superfund Health Risk Technical  Support Center

Jamie VanBuskirk
U.S. EPA
Region VI
     This memorandum responds  to your  request for a review of
issues raised in Comments on the Proposed  Plan for D.L.  Mud Site.
Thank you for your patience while  we attempted to resolve the
questions surrounding the appropriate  choice of critical study
for the subchronic and  chronic RfDs for barium.   Although they
have misinterpreted some of our earlier communications with you,
the comments do raise some pertinent questions regarding barium.
We have concluded that  because of  widely differing scientific
judgement, we cannot resolve these issues  in the forum of ECAO
alone.  Therefore, we plan to  present  these issues to the
Agency's RfD/RfC Work Group for resolution.   I will let you know
when a date for the presentation has been  scheduled.

     Until the Work Group has  evaluated the new data, I recommend
that you continue using the value  that has already been reviewed
and verified by the Work Group: the RfD of 7E-2 mg/kg/day that is
currently on IRIS.  This value has also been adopted as the
subchronic value on HEAST.  Please let me  know if you need
additional information.
cc:  L. Papa
     J. Konz  (5204G)
                                                         Printed on Recycled Paper

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             Appendix #6




INFORMATION ON BARIUM BIOAVAILABILITY

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    \
    ,?   UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
L Paefi
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Attachment

                             Barium


Evaluation of Barium Desorption Pilot Study

     This study was performed and reported by ChemRisk (1992) at
the request of Dow Chemical.  The study quantifies desorption of
total barium from soil samples containing low and high
concentrations (510 and 16,000 mg/kg, respectively) of barium
under conditions intended to simulate the human gastric
environment.  It is stated that soil material was "...taken from
an area impacted by barium sulfate." Based on this statement it
is possible that the test samples were from the Superfund site,
but this needs to be clarified.

     An aqueous HC1 solution of pH ^1.4 (0.04M) was used as the
extraction medium.  As indicated in the ChemRisk (1992) report,
this pH is representative of gastric fluid pH (normal = <2.0) as
reported in Appendix 3 of Clinical Diagnosis by Laboratory
Methods (Davidsohn and Henry, 1974).  An extraction ratio of 200
mg soil to 50 ml acid solution was chosen to reflect conditions
in children.  Although 200 mg/day is the default value for
incidental soil ingestion by children 1-6 years old (U.S. EPA,
1989), it is uncertain whether 50 ml is an appropriate
corresponding fluid volume.  ChemRisk (1992) states that "...50
ml is a volume within the range of normal gastric fluid volumes
(under basal conditions) for children (20-100 ml; Clinical
Diagnosis by Laboratory Methods, 1974)." The basis for this
statement appears to be an entry in Appendix 3 reporting that the
normal value for fasting residual gastric fluid volume is 20-100
ml, but no age group is specified.  Chapter 16 in the same book
(Davidsohn and Henry, 1974) indicates that the fasting volume of
gastric contents ranges from approximately 50-100 ml, and James
(1957) assumes that the volume of fasting stomach contents is 50
ml.  Neither Davidsohn and Henry (1974) or James  (1957)
specifically provide age data.  Based on discussions related to
these and other gastric data in the aforementioned books,
however, it is more reasonable to assume that the reported
gastric fluid volumes are for adults; 50 ml may or may not be a
reasonable maximum volume in children.  Other available reference
sources provided no information on gastric fluid volumes in
children (Oberhelman, 1968; Davenport, 1971; Guyton, 1981; ICRP,
1981; Johnson et al., 1987; Rotterdam and Enterline, 1989).
Ideally, soil ingestion and gastric fluid volumes for  children
and for adults should be tested.  An extraction ratio  of 100 mg
soil  (default daily ingestion value for. adults) to 100 ml acid
solution (reasonable maximum adult fasting gastric fluid volume)
may give a higher percentage extraction of barium, and hence
could yield a higher soil ingestion exposure estimate  and
therefore a higher hazard quotient.
     The soils were extracted with the acid solution for 1 hour
at 37%C with gentle agitation.  The extraction time apparently  is
intended to represent gastric residence.  The basis for the

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selection of the 1 hour time is unclear as the only statement in
the ChemRisk (1992) report  ["A large meal (comprising a majority
of gastric capacity) is retained in the stomach for up to 4
hours...] cannot be verified using the cited reference (Davidsohn
and Henry, 1974).  Studies  conducted by Oberhelman (1968) using
food to which barium was added showed emptying times of 4-5 hours
in normal subjects (apparently adult), but no additional
information on these studies was reported.  Oberhelman (1968)
also indicates that other studies (no additional information
reported) have showed emptying times ranging from 3-6 hours in
normal adult subjects (i.e., without gastrointestinal disease).
Data discussed by Davenport (1971) indicate that most of a meal
was cleared from the stomach within  1-2 hours.  These variations
in emptying time are not surprising because rate of emptying is
influenced by various factors, particularly the volume, osmotic
pressure and chemical composition of the meal (Davenport, 1971).
Fat content, for example, has a pronounced effect on emptying
time and meals composed largely of fat can remain in the stomach
for up to 20 hours (Davenport 1971).  Based on the available
information, the 1 hour extraction time appears to be a low
estimate of emptying time.  It would have been informative if a
longer extraction time (or  times) was tested because it is likely
this would give a more conservative soil ingestion exposure
estimate and hazard quotient for the same reasons as a decrease
in soil/acid extraction ratio as discussed above.

     The extraction conditions are obviously a simplistic
simulation of actual gastric conditions.  Gastric fluid, for
example, is a complex solution containing digestive and
nondigestive enzymes, mucus, electrolytes, serum proteins and
miscellaneous substances in addition to hydrochloric acid
(Davidsohn and Henry, 1974).  Large meals can increase stomach
content volume (e.g., to 1000 ml) and, by a dilution effect, pH
of the gastric content to as high as 5 (James, 1957; Brunton,
1990).  In general, however, the approach seems reasonable for a
pilot study, although the specific conditions that were used do
not appear to be conservative as discussed above.

     Other aspects of the study are adequate for a pilot study.
The quality control report  indicates that the study was carefully
performed and recoveries and precision were good.  This was even
true for the high concentration samples where the amounts
desorbed were 2.4 and 2.5%.  The reason for 2.4/2.6% desorption
from the high concentration samples compared with 19% from the
low concentration samples is not explained.  Little information
is available in the literature on the adsorption and desorption
of barium.  However, barium may form specific bonds with soil
components as well as interact through nonspecific columbic or
electrostatic interactions  (Rai and Zachara, 1984).  Interactions
are particularly strong with iron and manganese oxides.  The two
soil samples used in the pilot study may have had very different
properties which could explain why barium was more tightly bound
(lower desorption) in the high concentration sample.  Considering
the large difference in desorption from the two soils, it would
have been useful if the study included characterized soils and

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more soil samples.  However, the results of the study as
performed appear to be valid.

Relevance of the Desorption Study to Barium Risk Assessment

     According to the introduction section of the ChemRisk (1992)
report, the intent of the desorption study is to develop the data
necessary to enable adjustment of the soil ingestion exposure
estimate to match the RfD which is based on data from drinking
water ingestion.  However, understanding the ChemRisk (1992)
approach in using these data is complicated somewhat by
imprecise, misleading and sometimes synonymous use of the terms
absorption, bioavailability and uptake, as well as some
incomplete reporting of information.  For example, ChemRisk
(1992) states that the RfD "...was based on the study conducted
by Wones et al.  (1990) that administered barium chloride in
drinking water to 11 male volunteers."  In fact, the RfD is based
on both this study and an epidemiology study by Brenniman and
Levy (1984).  As discussed in U.S. EPA (1992), Brenniman and Levy
(1984) compared human mortality and morbidity rates in
populations ingesting elevated barium levels in their drinking
water to populations ingesting very little or no barium.
Although the NOAEL on which the RfD is based (10 mg Ba/L or 0.21
mg Ba/kg/day) is the same in both studies, the form of barium in
the drinking water in the Brenniman and Levy (1984) study is not
defined.

     ChemRisk (1992) cites only part of the guidelines that
specifically address adjustment for medium of exposure [Appendix
A (Section A.3, pages A-3 and A-4) of RAGS HHEM Part A (U.S. EPA,
1989)].  This part of the guidelines indicates that estimates of
the relative absorption efficiencies of a substance in the
different media are needed for the adjustment.  ChemRisk (1992)
fails to acknowledge, however, the rest of these guidelines which
state "In the absence of a strong argument for making this
adjustment or reliable information on relative absorption
efficiencies, assume that the relative absorption efficiency
between food or soil and water is 1.0."  ChemRisk  (1992) also
does not acknowledge that Chapter 8 (Section 8.1, page 8-5) of
RAGS more strongly states that although adjustment for medium of
exposure is occasionally appropriate, it is "...not generally
recommended unless there is a strong argument for doing so."  As
discussed below, the desorption study provides informative
preliminary data but an insufficient basis for deriving actual
adjustment values.                                            '

     Adjusting for differences between the RfD based on barium
chloride and other soluble forms of barium in water to water-
insoluble barium sulfate in soil involves considering both
bioavailability and absorption.  Bioavailability  is an important
concern in this assessment because only the barium sulfate that
desorbs from soil in the gastrointestinal tract will be available
for absorption  (i.e., bioavailable).  The hazard  quotient  (ratio
of soil ingestion exposure dose to RfD) therefore has to reflect
relative bioavailabilities as well as relative absorption

-------
efficiencies of the different forms of barium between the media.
The soil desorption values are essentially bioavailability
adjustment factors and are potentially useful for adjusting the
numerator (exposure dose) of the Hazard Quotient.  The
denominator (RfD) of the Hazard Quotient needs no adjustment for
bioavailability because bioavailability (particularly of barium
chloride) from drinking water can be assumed to be 100%.  This
essentially is the approach taken by  ChemRisk (1992) except that
the adjustment is erroneously referred to as an absorption
adjustment.   The desorption study provides no data on oral
absorption of barium sulfate from soil, and does not consider
existing data on absorption of barium compounds by oral and other
routes.  As mentioned above, the OPPT Bioavailability/Absorption
Review of Barium Sulfate (6/3/92 memo) concluded that there is
little, if any, difference in the gastrointestinal absorption of
barium by rats from oral administration of a solution of barium
chloride or suspension of barium sulfate in water.  Based on this
in vivo evidence of similar oral absorption of barium chloride
and sulfate (McCauley and Washington, 1983), no adjustment is
needed for relative absorption of the different forms of barium
in the Hazard Quotient (i.e., the relative absorption is 1J~.

     We have taken the position in previous assessments that the
Agency's RfDs and other toxicity values are medium-specific for
water, diet or gavage vehicle only when specified and that
adjustment for ingestion of chemicals in soil is necessary only
when data clearly show a difference between absorption from soil
versus water,  diet or gavage scenarios.  As for many other
chemicals, the Agency has not explicitly discussed medium
specificity in deriving the RfD for barium.  The RfD applies to
total barium,,  but its derivation does not consider toxicity from
media other than water or from barium sulfate (or other poorly
water soluble barium compounds) because relevant data were not
available.  As discussed above, there is no evidence indicating
that oral absorption of barium from barium chloride or sulfate
substantially differs at the low doses anticipated in
environmental exposure situations.  The desorption study provides
information suggesting that bioavailability of barium sulfate
from soil is much less than that from water.  However, as
previously discussed, EPA guidelines clearly indicate that
adjustment for medium of exposure is not generally recommended
unless there is a strong argument for doing so.  In general,
study limitations as discussed above indicate that, at this time,
although data from the pilot study suggest that adjustment for
medium of exposure may be appropriate, the data are not
conclusive and are not adequate for quantifying an actual
bioavailability factor for barium sulfate in soil.

     One of the main problems with the pilot study is the
nonconservative approach taken by ChemRisk (1992) in designing
the experiment, particularly in the selection of extraction ratio
and time, and the lack of information regarding the soil samples
tested.  If only one combination of extraction ratio and time
could be tested, it would have been far more appropriate to
select conservative conditions as the basis for possible

-------
adjustment of the exposure dose.  The wide range of extraction
efficiencies, 2.4/2.6% and 19%, is problematic because soils with
only two concentrations of barium were tested, only two soil
samples per concentration were tested, and soil types were not
characterized.  ChemRisk (1992) concluded that there appears to
be a concentration and/or extractant volume dependence to the
extraction efficiencies, but soil properties could explain the
variation as discussed above.  Additionally, it is unclear if the
soil samples were from the actual site.

     Additional uncertainties and limitations of the pilot study
include the following:  1) Speciation of the desorbed barium was
not determined.  Speciation may be different for barium desorbed
from barium sulfate-contaminated soil than for barium from the
chloride or sulfate in water and bioavailabilities of all species
may not be the same.  2) Desorption was quantified in simulated
gastric fluid, whereas absorption will occur in the small
intestine, which has a very different chemical environment.  This
limitation could be addressed by adding a neutralization step to
the extraction procedure to simulate the intestinal environment.

     Consideration might be given to using EPA's Metal Speciation
Equilibrium Model (MINTEQ) to explore both of the above
limitations along with the problem of soil type.  This model has
been applied to predicting speciation of metals (e.g. lead) in
the gastrointestinal tract.  Given certain assumptions about
which barium species would be substrates for transport in the
gastrointestinal epithelium, MINTEQ could be used to estimate
relative bioavailabilities of barium compounds in chemically
characterized soil types.

References

Brenniman, G.R. and P.S. Levy.  1984.  Epidemiological study of
barium in Illinois drinking water supplies.  In: Advances in
Modern Environmental Toxicology IX, E. J. Calabrese, R.W. Tuthill
and L. Condie, Ed.  Princeton Scientific Publications, Princeton,
NJ.  pp. 231-240.

Brunton, L.L.  1990.  Agents for gastric acidity and peptic
ulcers:  Antacids.  In;  The Pharmacological Basis of
Therapeutics, 8th ed, A. Goodman Gilman, T.W. Rail, A.S. Nies and
P. Taylor, Eds.  Pergamon Press, New york. p. 905.


ChemRisk.  1992.  Barium desorption study summary.  Prepared by
ChemRisk, A division of McLaren/Hart, Cleveland, OH.  September
9, 1992.

Davenport, H.W.  1977.  Gastric digestion and emptying;
absorption.  In:  Physiology of the Digestive Tract, 3rd ed.,
Year Book Medial Publishers Inc, Chicago,  pp.  165-168.

Davidsohn, I. and J.B. Henry.  1974.  Clinical  Diagnosis by
Laboratory Methods, 15th ed.  W.B. Saunder Co,  Philadelphia,  pp.

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887-904, 1387.

Guyton, A.C.   1981.  Textbook of Medical Physiology, 6th ed.
W.B. Saunders  Co, Philadelphia.

ICRP.  1981.   Report of the Task Group on Reference Man.
International  Commission on Radiological Protection Publication
No. 23.  Pergamon Press, Oxford.

James, A.H.  1957.  The effects of eating on gastric acidity.
In;  The Physiology of Gastric Digestion.  Edward Arnold
Publishers Ltd., London,  pp. 44-46.

Johnson, L.R., J.C. Christensen, M.J. Jackson, E.D. Jacobson and
J.H. Walsh, Eds.  1987.  Physiology of the Gastrointestinal
Tract, Second  Edition.  Volumes 1 and 2.  Raven Press, NY.

McCauley, P.T. and I.S. Washington.  1983.  Barium
bioavailability as the chloride, sulfate, or carbonate salt in
the rat.  Drug Chem. Toxicol.  6(2): 209-217.

Oberhelman, H.A., Jr.  1968.  Gastric secretion and motility,
In;  Physiological Principles of Gastric Surgery.  Charles C
Thomas Publisher, Springfield, IL. pp. 17-20, 40.

Rai, D. and J. M. Zachara.  1984.  Chemical Attenuation Rates,
Coefficients,  and Constants in Leachate Migration. Volume 1:  A
Critical Review.  Prepared by Battelle Pacific Northwest
Laboratories,  Richland, WA for the Electric Power Research
Institute, Palo Alto, CA.  EPRI EA-3356.  DE84-009432.  pp. 6-1 -
6-6.

Rotterdam, H.  and H.T. Enterline.  1989.  Physiology.  In:
Pathology of the Stomach and Duodenum.  Springer-Verlag, London.

U.S. EPA.  1989.  Risk Assessment Guidance for Superfund.  Volume
I.  Human Health Evaluation Manual (Part A).  Office of Emergency
and Remedial Response, Washington, DC.  EPA/540/1-89/001.

U.S. EPA.  1992.  Integrated Risk Information System  (IRIS).
Online.  Office of Health and Environmental Assessment,
Environmental  Criteria and Assessment Office, Cincinnati, OH.

Wones, R.G., B.L. Stadler and L.A. Frohman.  1990.  Lack of
effect of drinking water barium on cardiovascular risk factor.
Environ. Health Perspect.  85: 1-13.

-------
       •5 -
       I      UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
 *
                         WASHINGTON, D.C. 20460


            3 ,'992
MEMORANDUM                                              OFFICE of
                                                     PESTCIDES AND TOXC
                                                       SUBSTANCES

SUBJECT:  Bioavailability of Barium Sulfate
                                                          cP.
FROM:     Terry O« Bryan   (TS-7T8)   /_^
          Chemical Assessment Desk  '   ~y
          Office of Pollution Prevention and Toxics            \

TO:       Ghassan Khoury  (6H-SR)                               -?.
          Hazardous Waste Management  Division                   ~^_
          EPA Region 6                                       .-• ^
                                                                 7*O
                                                              r"r  CJ

     This is in response to your 5/28/92  inquiry on barium sulfate.
I understand that barium is driving  the risk assessment at a Region
6 Superfund site (barium accounts for 92% of the soil contaminants
at the  site) .   There is an  IRIS  reference dose  (RfD)  for barium
chloride, but the PRP questions its applicability to the much less
soluble barium sulfate.

     In  1989,  Dr.  Leonard  Keifer  of the then  Office of  Toxic
Substances  evaluated the bioavailability of barium sulfate  in
response  to a petition to  delist  this  chemical from  the Toxics
Release Inventory..  The evaluation indicates that there is little^
jLf  any,  dif ferencej^in absorption at  low doses following" oral
administratijQiu^"  Barium  sulfate  is "belieVecl  to be~ converted to
barium" chloride  in  the  stomach.   Differences  would be  likely
following massive doses because of the much lower water solubility
of barium sulfate.  However,  for  the  doses for which we have data
barium  sulfate  is absorbed from the GI tract to approximately the
same extent as barium chloride.   In the  McCauley  and Washington
(1983)  study which  reported similar  absorption  rates for the two
salts, the administered oral dose was  0.5 mL/lOOg b.w of 10 mg/L of
Ba solution OR  5 M/kg.  No comparative oral absorption data exist
for  higher  doses, but  clinical  data  indicate  significant uptake
within  four hours.   Consequently,  the  slower absorption rate of
barium  sulfate relative to barium chloride would seem to have more
relevance  to   acute  exposure  situations  rather  than  chronic
exposures,  the  basis for  the RfD.

     Absorption  rates  differ between  the two salts  following
inhalation  exposure,  but measured  differences are  less  than one
order  of magnitude.    Attached  is  a  copy  of  Leonard  Keifer's
evaluation.  He has not done  any additional work on this topic, but
you can reach him at  (202) 260-1548 if you have questions.

-------
             UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

                        WASHINGTON, D.C. 20460
       8 1989
                                                  OFFICE OF
                                               PESTICIDES AND TOXC
                                                 SUBSTANCES
MEMORANDUM

SUBJECT:  Bioavailability/Absorption  Review of Barium Sulfate  in
          Response to  a Petition to Delist the Material  from the
          Toxic Emissions Inventory

FROM:     Leonard C. Keifer, Ph.D.
          Chemist
          Metabolism/Structure Activity  Section
          Toxic Effects Branch
          Health and Environmental
            Review Division  (TS-796)

TO:       Flora Chow
          Technical Integrator
          Chemical Review and Evaluation Branch
          Health and Environmental
            Review Division  (TS-796)

THRU:     Pauline Wagner
          Section Chief
          Metabolism/Structure Activity  Section
          Toxic Effects Branch
          Health and Environmental
            Review Division  (TS-796)
I.
INTRODUCTION
     Barium sulfate  (BaSO<, CAS No. 7727-43-7) is a solid with low
water solubility  (2.46 mg/L i 25°C).   The molecular weight is 233.

     A water-soluble barium  (Ba)  compound used in several studies
to compare the bioavailability of  Ba from  its salts  is barium
chloride  (BaCl2)  with water solubility of 375,000 mg/L (375 g/L) €
26°C  and molecular weight of 208.

II. CONCLUSIONS

     The barium ion  from BaS04  is  absorbed slowly into the animal
system as  the  compound dissolves.  This  bioavailability has been
observed  following  intramuscular injection,   oral  dosing,  and
inhalation or intratracheal instillation.  Following intratracheal

-------
instillation in rats, approximately 1.3% of the Ba from a dose of
2.8 fig of BaS04 was absorbed via solubilization.  From in vivo and
in vitro studies with freshly precipitated and heat treated BaSO4
the physical fora of  the BaS04 appears to have a profound influence
on the amount of Ba available from the compound.  For small doses
of BaSO^jtdministered orally there is little, if any, difference in
the "alnount. of Ba_._ab.s orbed—when.. cpmpjired__to___the much  more ~wate~r_
soluble BaCl2.  When massive doses of BaS04 (60 to~400~g) were given"
orally to human subjects as a contrast medium for x-ray diagnoses
approximately 10 to 100 ng of Ba above background was excreted in
the urine in 24 hours.

III. BASES FOR.CONCLUSIONS

     Thomas et al. (1973) studied the solubility (or more approp-
riately the bioavailability)  of  Ba from several of  its  salts in
vivo in the rat using the  radioisotope   Ba.   The  compounds of
interest were the chloride, sulfate,  and an aluminosilicate clay
containing Ba fused at 1,100°C.  The compounds, with the exception
of the chloride,  were aerosolized,  collected on a membrane filter,
resuspended in distilled water, and  0.5 mL of the suspension was
injected into the right hind leg  of rats.  The clay was used as an
example of  a  Ba compound  from which Ba was not expected to be
available.  The authors measured  the rate at which   Ba left the
injection site.    Ba from BaCl2  was gone from the injection site
within  3  days  whereas    Ba  from the  clay migrated  from  the
injection site with  a halflife of approximately  1,390 days  (3.8
years) or nearly  twice the average lifespan of the  rat.  Inter-
mediate between these two extremes was BaSO4 with a halflife of 26
days.  The  authors  also  calculated the  dissolution  rate for the
clay and BaSO4 in terms of grams dissolved per cm of surface of the
particles injected per day:  BaSO4,  6.9  x 10" g/cm/day,  and clay,
2.3 x 10"8 g/cm/day.

     Cuddihy et al.  (1974)  exposed groups of three beagle dogs via
inhalation to aerosols of  BaCl2,  freshly precipitated  BaS04, heat
treated BaSO4, or Ba fused in  clay;  exposure conditions were not
reported.   In addition they  collected samples of the aerosols on
membrane filters  for use in an in vitro dissolution study.  The
collected  aerosol particles  were  placed  between  two  membrane
filters and placed into simulated blood plasma.  The samples were
placed into fresh solvent after 4  hours  and thereafter  at frequent
intervals for 20 days.  The clay samples were subsequently placed
into fresh solvent every 10 days from day 20 to  day 50 and  then
every 50 days to a total of 125 days.

     The BaCl2 in the in vitro study dissolved with a  halflife of
approximately 1 hour while the clay dissolved with a  halflife of
430 days.  The BaS04 samples had half lives intermediate between the
BaCl2 and the clay,  values were  not reported.   After 20  days
approximately  40% of  the heat  treated and 7%  of  the  freshly
precipitated Baso4 remained on the  filter.   By comparison essen-
                              U

-------
tially none of the  "3Ba from BaCl2 remained of the filter after -1
day and 80% of the   Ba from the  clay remained on the filter after
125 days  (Cuddihy et al., 1974).

     In the  in vivo portion of  the study Cuddihy  et  al.  (1974)
sho^|d that for BaCl2 approximately 50% of the initial body burden
of   Ba (amount not reported) was translocated to the skeleton by
day  16.   For  BaSO4/ approximately 35%  of the   Ba  from freshly
precipitated and 20% from heat treated compound was translocated to
the  skeleton  by  day 16; at  the  same  time  approximately 5%  of
freshly precipitated and approximately 30% of heat treated compound
remained  in the lung.  By comparison only approximately 2% of the
  Ba from the clay was  translocated to the skeleton in 16 days and
approximately 50% remained in the lung.  Even at 500 days less than
5% of the  Ba from the clay had translocated  to the skeleton while
nearly 10%  remained in  the lung.   It should  be kept  in  mind,
especially for the two  forms  of  BaS04, that  there is  the  pos-
sibility  that at  least  some of the  Ba in  the skeleton may have
been absorbed  from the GI  tract since  we do not know  the  exact
method of exposure and  at  least  a portion  of the  initial  body
burden could have  been  swallowed during  or  immediately  after
exposure.

     Takahashi and Patrick  (1987)  administered a  suspension  of
  BaSO4 in mannitol to  26 male Fischer 344 rats via intratracheal
intubation; the average  dose was 2.8 fig of  BaSOA per  rat.   Rats
were killed at intervals up to 24 weeks post-administration.   The
trachea,   in two pieces divided  5 mm below the  tracheostomy; the
bronchi including the  tracheal  bifurcation;  the larynx including
the pharynx;  the lung lobes; the thoracic and  cervical lymph nodes;
and the remaining carcass were  collected when each rat was killed.
The halflife  for  clearance from the  lower half  (caudal) of the
trachea  was  88  days  and  that  from  the upper  half  (cranial,
including the  site of the  trachec-stomy)  was 66 days.   The per-
centage of the initial dose of    Ba  present in the  trachea was
highest at week one:  caudal, 0.41 ± 0.13%,  and cranial, 4.0 + 1.2%.
The percent of the dose present  in the larynx, bronchi, and lymph
nodes were  also  highest  (but   lower than  that  present in the
trachea)   at week  one.   In contrast the  percent of dose reached a
maximum (1,%^%) in the  lung at 4 weeks  post-administration.   The
amount of  Ba  in  all of these tissues decreased steadily over the
remainder of the study.  The percentage of the dose present in the
remaining carcass reached a maximum  of approximately  1.3%  at 4
weeks post-administration and  remained  constant throughout the
remainder of the  study; the .ffudy authors attributed this to the
translocation of some of the  Ba to the  skeleton although they did
not specifically analyze bone for the presence of   Ba.  According
to the authors,  clearance from  the trachea  does  not necessarily
indicate solubilization of the BaSO4 since only  0.001 to 0.003% of
the dose was  present in the  blood of rats at  24 hours and 30 days,
respectively, while greater than 90% of the dose was cleared from
the trachea over the same period.  It was, however, pointed out by

-------
the authors  that  the percentage of the dose  translocated  to the
bones was via the solubilized Ba ion.

     McCauley and Washington (1983) dosed fed ,5>ale Sprague-Dawley
rats with either  BaCl2 or BaS04 labeled with   Ba and fasted rats
with^ labeled BaCl2;  doses were 0.5 mL/lOOg body weight of 10 mg/L
of   Ba solution.   Within 15 minutes of dosing the blood Ba level
in the  fasted rats dosed with BaCl2  was  at a maximum  (0.35 ex-
pressed as counts per minute(CPM)/mL blood divided by administered
CPM/g body weight;  by 4 hours postdosing the Ba level had fallen
to approximately 50% of the maximum level.  The blood Ba level in
fed rats dosed with BaCl2 reached  a maximum (0.28)  at 60 minutes
postdosing.   In  fed rats  dosed with  BaS04  the blood  Ba level
reached a  maximum  (0.19) at 60 minutes  postdosing and was ap-
proximately 80 - 90% of the  levels reached in the  BaCl2-dosed rats.
Ba levels in the eye,  an  organ  known to accumulate Ba, were nearly
the same  for BaCl2- and  BaSO4-dosed rats after  60  minutes  (0.48
CPM/g eye/admin. CPM/g body weight);  at  120  min the Ba level in
the eye for the BaCl2-dosed  rats had increased to a level of 0.68
and that for the BaSO4-dosed rates to 0.52.   Although data in terms
of percent of  administered  dose were not  presented,  the authors
concluded that BaCl2 and BaS04  at the  doses used  in  this study are
absorbed to approximately the  same extent  from the rat GI tract,
presumably by conversion of BaS04 to BaCl2  in the stomach.

     In the  course  of conducting GI tract  X-ray diagnoses on 10
patients, Mauras  et al.  (1983)  studied the absorption  of Ba as
indicated by both  increased  Ba levels in the blood and increased Ba
levels in 24-hour urine samples.  Each patient was given 350 g of
BaSO4  in 220  mL of water  (210 g of  Ba ion).  Blood was drawn prior
to administration of the  BaSO4 and at 0.5,  1, 2, 4, 8, and 24 hours
post-administration.   In  addition a 24-hour  urine  sample was
collected  before and one  after  administration  of  the  BaSO4.
Statistical  significance was  determined  using the  method  of
Wilcoxon.  The  average blood Ba  level  before administration was
0.76 Mg/L; levels were not  significantly increased until 4  (2.53
Mg/L,  significance  at 1%)  and 8  (1.31  M9/L,  significance at 5%)
hours after administration.  Average  pre-administration urine Ba
levels were  4.2  ng/24h;  average  post-administration levels were
13.4 /*g/24h  (significant at 1%).

     In a  separate  study using radio-opaque contrast materials,
Claval et al. (1987) administered six different  contrast formula-
tions orally and four  were administered  rectally to patients.
BaSOA  content of the contrast materials ranged from 57.5 g to 400
g per dose.   Urine was collected for 24 hours post-administration.
For all  of the formulations  administered orally the Ba excretion in
the urine, expressed  on  a per  gram of administered Ba basis, was
fairly constant;  the range was 0.16 ng/q of Ba administered to 0.26
Mg/g of  Ba.   For the formulations administered rectally the Ba
excretion in the urine was approximately an order of magnitude less
than for the orally-administered formulations; the range was 0.023

                                4

-------
/ig/g of Ba to 0.096 /^g/g of Ba.  These results suggest that passage
through the stomach increases the bioavailability of Ba, presumably
by conversion of a  small amount of  BaSO4 to BaCl2.

-------
                            REFERENCES

Cuddihy RG, Hall RP, Griffith WC.  1974.  Inhalation exposures to
barium aerosols:   Physical, chemical  and mathematical analysis.
Health Phys. 26:405-416.

Claval JP,  Lorillot ML, Buthiau  D,  Gerbet D, Heitz  F,  Galli A.
1987.    Absorption  intestinale  du   baryum   lors  d1explorations
radiologiques.  Therapie 42:239-243.

Mauras Y, Allain P, Rogues MA,  Caron  C.   1983.  Etude de 1'absorp-
tion digestive du baryum apres 1' administration orale du sulfate de
baryum pour exploration radiologique.  Therapie 38:107-118.

McCauley PT, Washington IS.  1983.  Barium bioavailability as the
chloride,  sulfate,  or  carbonate salt  in the  rat.    Drug Chem.
Toxicol.  6(2):209-217.

Takahashi S, Patrick G.  1987.   Long-term retention of 133Ba in the
rat  trachea  following local  administration  as  barium sulfate
particles.  Rad. Res. 110:321-328.

Thomas RG,  Ewing WC,  Catron  DL, McClellan  RO.    1973.   In vivo
solubility of four forms of barium determined by scanning techni-
ques.  Amer. Ind. Hyg. Assoc. J.  34(8):350-359.

-------
Appendix #7




   TABLES

-------
                          LIST OP TABLES


TABLE #1  - SURFACE  SOIL SAMPLING RESULTS SUMMARY

TABLE #2  - SUBSURFACE  SOIL  SAMPLING RESULTS FROM AREAS  OF
            HISTORICAL  USE

TABLE #3  - SUBSURFACE  SOIL  SAMPLING RESULTS FROM MONITORING WELL
            INSTALLATION

TABLE #4  - SUBSURFACE  SOIL  SAMPLING RESULTS NEAR WELL G-22

TABLE #5  - SUBSURFACE  SOIL  SAMPLING RESULTS NEAR WELL G-23

TABLE #6  - SUBSURFACE  SOIL  SAMPLING RESULTS NEAR BORING SB-30

TABLE #7  -  SUBSURFACE  SOIL  SAMPLING  RESULTS  FROM THE  FORMER
            IMPOUNDMENT AREA

TABLE #8  - GROUND WATER SAMPLING RESULTS SUMMARY

TABLE #9  - SURFACE WATER SAMPLING RESULTS SUMMARY

TABLE #10 - ONSITE SEDIMENT  SAMPLING RESULTS SUMMARY

TABLE #11 - CHEMICALS DETECTED ONSITE USED IN THE RISK ASSESSMENT

TABLE #12 - POTENTIAL EXPOSURE PATHWAYS

TABLE #13 - CARCINOGENIC POTENCIES (ORAL SLOPE FACTORS)

TABLE #14 - NONCARCINOGENIC REFERENCE DOSES

TABLE #15 - SUMMARY OF  POTENTIAL CARCINOGENIC RISKS

TABLE #16 - SUMMARY OF  POTENTIAL NONCARCINOGENIC RISKS

TABLE #17 - CUMULATIVE  POTENTIAL RISKS - TRESPASSER

TABLE #18 - CUMULATIVE  POTENTIAL RISKS - FUTURE RESIDENTIAL

TABLE #19 - CUMULATIVE  POTENTIAL RISKS - OCCUPATIONAL

TABLE #20 - D.L. MUD RISK ASSESSMENT UNCERTAINTIES

TABLE #21 - CHEMICALS OF CONCERN FOR SURFACE SOILS

-------
              Table #1



SURFACE SOIL SAMPLING RESULTS SUMMARY

-------
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-------
                    Table  #2

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HISTORICAL USE

-------



























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-------
                       Table #3

SUBSURFACE SOIL SAMPLING RESULTS FROM MONITORING WELL
INSTALLATION

-------
                                                      Table  #  3
" bsurface Soil Concentrations Above Background Surficial Soil Values
for Monitoring Well Samples
Parameters
Inorganics (mg/kg)
ALUMINUM
BERYLLIUM
CHROMIUM (TOTAL)
IRON
MAGNESIUM
NICKEL
Maximum
Background

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26400
1440

Results prewnted on dr> -weight basis
Blank space indicates parameter was below rr.aximum background value.
J - Estimated value
S - Matrix spike recoveries - outside control limits
D - Inorganics - Duplicate control limits exceeded
F - I.iorgvjc data  below contract  required quantitation limit
B - Blink contamination

-------
                    Table  #4



SUBSURFACE SOIL SAMPLING RESULTS NEAR WELL G-22

-------
                                                               Table
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-------
                    Table  #5



SUBSURFACE SOIL SAMPLING RESULTS NEAR WELL G-23

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-------
                     Table #6



SUBSURFACE SOIL SAMPLING RESULTS NEAR BORING SB-30

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Table f 6






















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-------
                    Table #7

SUBSURFACE SOIL SAMPLING RESULTS FROM THE FORMER
IMPOUNDMENT AREA

-------
                    Table t 7


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-------
               Table  #8



GROUND WATER SAMPLING RESULTS SUMMARY

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-------
               Table #9



SURFACE WATER SAMPLING RESULTS SUMMARY

-------
                                                     Table  #  9
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-------
                Table  #10




ONSITE SEDIMENT SAMPLING RESULTS SUMMARY

-------
                                                         Table  # 10
•
Onsite Sediment Samples Above Maximum Background Sediment Concentrations
Parameters
Inorganics (mg/kg)
ARSENIC
CADMIUM
COPPER
Maximum
Background
5.6
22.6
Station ID
SD-2 . SD-5
1.7F
22.7JBDE
6.7
1.5FJB
24.5JB
SD-6
9.4
2.1
25.3JB
SD-6A
7.2JS
23.4
SD-8
10.5
13.5
56.8
SD-9
23.9JB
Blank space indicates parameter was either below the method detection
limit or the parameter uas belo* the maximum background concentration detected.
B - B!ar.y. contamination
D - Inorgir.ics—duplicate control ami's exceeded
E - Interference problem
F - Inorganic data below  contract required quantitation limit
J - Est- mated value
S - Matr.* spike reco^eries-outside control limits

-------
                      Table #11




CHEMICALS DETECTED ONSITE USED IN THE RISK ASSESSMENT

-------
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                                                Table #  11

                                  Chemical Constituents Identified in Onsite Groundweter
Inorpanic Parameters
ALUMINUM
ANTIMONY
ARSENIC
BARIUM
BERYLLIUM
CADMIUM
CALCIUM
CHROMIUM
COBALT
COPPER
IRON
LEAD
MAGNESIUM
MANGANESE
NICKEL
POTASSIUM
SELENIUM
SILVER
SODIUM
THALLIUM
VANADIUM
ZINC
Total Positive Detection
Analyses Detections Freguency
19
19
19
19
19
19
19
52
19
19
19
19
19
19
19
19
19
14
19
19
19
19
18
1
18
19
2
1
19
21
8
18
19
11
19
19
14
19
4
5
19
8
13
14
95%
5%
95%
100%
11%
5%
100%
40%
42%
95%
100%
58%
100%
100%
74%
100%
21%
36%
100%
42%
68%
74%
Minimun
Detected
Value (a)
33
65
1.1
212
1.2
3.6
40800
11
9.0
8.3
98
1.7
9660
170
12
1390
8.2
4.9
74400
1.0
5.4
14
Maximum
Detected
Value
52500
65
43
1430
3.1
3.6
349001
852
43
68
80500
59
145000
4900
412
13200
13
6.6
229999
51
129
81
Mean
Estimation
(b)
10401
20
18
490
^ ., -•- 0-6
1.7
82672
71
8.4
21
9698
14
28967
1303
82
4769
2.7
3.3
114711
13
16
39
UCL 95%
181495
23
59
661
0.8
1.9
109643
275
14
32
32818
69
41610
2140
214
6758
4.8
4.4
134868
89
38
65
Unite
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
Melal parameters art reported as total metals.
(a! Minimum detected velue:Positive detections only.
(b) Estimation of the mean of the log normal distribution.
Total Positive Detection
Organic Parameters Analyses Detections Frequency
ACETONE (2-PROPANONE!
BENZOIC ACID
BIS(2-ETHYLHEXYL)PHTHALATE
BROMOD1CHLOROM5THANE
BROMOFORM
CARBON TETRACHLORIDE
DI-N-BUTYL PHTHALATE
Di-N-OCTYL PHTHALATE
DIBROMOCHLOROMETHANE
DIETHYL PHTHALATE
METHYLENE CHLORIDE
19
19
19
19
19
19
19
19
19
19
19
2
1
6
1
1
1
2
1
2
2
12
11%
5%
32%
5%
5%
5%
11%
5%
11%
11%
63%
Minimun Maximum Mean
Detected Detected Estimation
Value (a) Value (b) UCL 95%
11
2.0
1.0
1.0
5.0
1.0
1.0
0.2
3.0
S.O
1.0
18
2.0
17
1.0
5.0
1.0
1.0
0.2
4.0
11
11
6.8
27
5.8
2.4
2.6
2.4
5.0
5.9
2.6
5.5
2.1
9.1
36
7.8
2.7
2.8
2.7
6.5
8.9
2.7
6.0
3.6
Units
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L

-------
                                          Table  f 11  (cont'd)

                               Chemical Counstituents Identified in Onsite Surface Water
Inorganic Parameter!
ALUMINUM
ARSENIC
BARIUM
BERYLLIUM
CADMIUM
CALCIUM
CHROMIUM
COBALT
COPPER
IRON
LEAD
MAGNESIUM
MANGANESE
NICKEL
POTASSIUM
SILVER
SODIUM
VANADIUM
ZINC
Total Positive Detection
Analyses Detections Frequency
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
9
11
1
1
11
5
3
11
11
11
11
11
6
11
3
11
7
11
100%
82%
100%
9%
9%
100%
45%
27%
100%
100%
100%
100%
100%
55%
100%
27%
100%
64%
100%
Minimun
Detected
Value (a)
1010
1.9
89
1.7
3.6
7440
8.8
6.2
6.2
810
1.5
2470
40
15
3100
5.3
3760
5.4
19
Maximum
Detected
Value
15100
6.5
6090
1.7
3.6
33900
64
12
31
9230
66
10500
3850
49
23600
6.1
9930
18
705
Mean
Estimation
(b)
4059
2.9
889
0.6
1.7
22073
11
4.6
17
3351
13
4311
881
16
9699
3.0
6298
7.3
241
UC'. 95%
8747
5.7
3963
0.8
2.0
31823
31
6.7
23
5845
47
5641
5563
28
15205
4.2
7518
13
678
Unitt
ug/L
ug/L
ug/L
ue/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ugA.
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
L
U
li
LJ
                                                                                                                  U
                                                                                                                  U
                                                                                                                  hi
Minimun Maximum Mean
Total Positive Detection Detected Detected Estimation
Organic Parameters Analyses Detections Frequency Value (a) Value (b) UCL 95%
BIS (2-ETH YLHiXYUP-'THALATE
OIETHYL PHTHALATE
6
6
4
1
67%
17%
3.0
2.0
7.0
2.0
5.5
5.4
7.4
8.8
Units
ug/L
ug/L
Metal parameters are reported as total metals.
(a) Minimum detected value:Positive detections only.
(b) Estimation of the mean of the log normal distribution.
u
[Jl
d
                                                                                                                  III
                                                                                                                  II
                                                                                                                   I
                                                                                                                  1
                                                                                                                  '1

-------
 J
 J
 j
 J
 J
 J
J
           Table  // 11  (cont'd)

Chemical Constituents Identified in Onsite Surficial Soil
Inorganic Parameters
ALUMINUM
ANTIMONY
ARSENIC
BARIUM
BERYLLIUM
CADMIUM
CALCIUM
CHROMIUM
COBALT
COPPER
IRON
LEAD
MAGNESIUM
MANGANESE
MERCURY
NICKEL
POTASSIUM
SELENIUM
SILVER
SODIUM
THALLIUM
VANADIUM
ZINC
Total Positive Detection
Analyses Detections Frequency
21
20
18
19
21
21
21
21
21
21
21
18
21
21
18
20
21
18
20
21
18
20
21
21
2
18
19
21
11
21
21
21
21
21
18
21
21
9
20
21
1
14
8
4
20
21
100%
10%
100%
100%
100%
52%
100%
100%
100%
100%
100%
100%
100%
100%
50%
100%
100%
6%
70%
38%
22%
100%
100%
Minimun
Detacted
Value (a)
3360
6.6
4.3
210
0.3
0.8
808
15
6.1
12
10800
14
717
293
0.1
6.3
203
0.6
0.8
181
0.2
14
24
Maximum
Detected
Value
17000
13
19
13500
1.2
6.9
110000
188
26
71
29400
643
1790
1420
1.2
21
1330
0.6
2.8
1010
20
47
1380
Mean
Estimation
(b)
9371
4.4
10
12870
0.6
2.3
43240
53
12
26
17749
265
1296
686
0.3
11
952
0.3
1.5
1268
0.4
26
706
UCL 95%
11073
5.3
12
39626
0.7
4.3
141566
76
14
32
19990
615
1447
805
0.5
13
1175
0.3
2.4
7209
1.0
30
1582
Units
mg/kg
nrtg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/Vg
Oroanic Parameters '
2-METHYLNAPHTHALENE
4-METHYLPHENOL
BENZOIA1PYRENE
BENZOIC ACID
BISI2-ETHYLHEXYUPHTHALATE
DI-N-BUTYL PHTHALATE
DIETHYL PHTHALATE
DIMETHYL PHTHALATE
INDENOI1.2.3-C.DIPYRENE
METHYLENE CHLORIDE
NAPHTHALENE
PHENANTHRENE
PHENOL
PYRENE
Total Positive Detection
Analyses Detections Frequency
18
18
18
14
18
18
18
18
18
4
18
18
18
18
1
1
1
2
15
9
1
1
1
1
3
1
2
1
6%
6%
6%
14%
83%
50%
6%
6%
6%
25%
17%
6%
11%
6%
Minimun Maximum Mean
Detected Detected Estimation
v.i, i« (•) Value 
-------
                                            Table  # 11  (cont'd)

                                    Chemical Constituents Identified in Onsite Sediment
Inorganic Parameters
ALUMINUM
ARSENIC
BARIUM
BERYLLIUM
CADMIUM
CALCIUM
CHROMIUM
COBALT
COPPER
IRON
LEAD
MAGNESIUM
MANGANESE
MERCURY
NICKEL
POTASSIUM
SILVER
SODIUM
VANADIUM
ZINC
Total Positive Detection
Analyses Detections Frequency
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
4
7
7
7
7
• 7
7
7
7
1
7
7
4
4
7
7
100%
100%
100%
100%
57%
100%
100%
100%
100%
100%
100%
100%
100%
14%
100%
100%
57%
57%
100%
100%
Minimun
Detected
Value (a)
9360
1.8
355
0.5
1.5
1320
13
6.9
11
10300
15
1090
267
0.7
5.1
948
1.7
1290
19
48
Maximum
Detected
Value
18100
11
18400
0.9
14
12800
97
20
57
22800
390
2150
631
0.7
20
2100
2.7
2210
39
2420
Mean
Estimation
(b)
14118
6.5
21269
0.7
2.8
4165
45
15
27
14953
97
1609
420
0.2
14
1724
1.5
1312
28
521
UCL 95%
17593
13
4.0E + 06
0.8
25
12398
126
21
44
18700
899
2022
584
0.4
21
2180
3.0
3619
36
10354
Units
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kj
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
Tig/kg
I
I
•
i
,
                                                                                                                         ,
Organic Parameters
BENZOIC ACID
BIS12-ETHYLHEXYUPHTHALATE
DI-N-BUTYL PHTHALATE
Total
Analyses
7
7
7
Positiva
Detections
1
6
4
Detection
Frequency
14%
86%
57%
Minimun
Detected
Value (a)
510
240
75
Maximum
Detected
Value
510
790
120
Mean
Estimation
(b)
3103
864
489
UCL 95%
15290
2842
5096
Units
ug/kg
ug/kg
ug/kg
Non-aqueous sample concentrations are based on dry weight.

Metal parameters are reported as total metals.
(a) Minimum detected value:Positive detections only.

(b) Estimation of the mean of the log normal distribution.
 i
 I
 t
 t

-------
 J
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 J
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11
if
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  1
              Table #  11 (cont'd)


Chemical Constituents Identified in Onsite Subsurface Soil Without " Source" Areas
Inorjanic Parameters
ALUM.NUM
ANTIMONY
ARSENIC
BARIUM
BERYLLIUM
CADMIUM
CALCIUM
CHROMIUM (TOTAL)
COBALT
COPPER
IRON
LEAD
MAGNESIUM
MANGANESE
MERCURY
NICKEL
POTASSIUM
SELENIUM
SILVER
SODIUM
SULFUR
THALLIUM
VANADIUM
ZINC
Total
Analyses
41
36
35
41
41
41
41
41
41
41
41
35
41
41
35
41
41
35
41
41
1
35
41
41
Positive Detection
Detects Frequency
41
5
35
41
, 41
2
41
41
40
40
41
35
41
41
10
41
41
5
13
36
1
4
41
41
100%
14%
100%
100%
100%
5%
100%
100%
98%
98%
100%
100%
100%
100%
29%
100%
100%
14%
32%
88%
100%
11%
100%
100%
Arithmetic
Mean
16272.44
3.81
5.24
484.31
0.86
0.36
3115.12
19.64
7.46
13.27
20515.37
12.94
2263.90
394.62
0.07
16.37
1098.80
0.33
0.60
667.18
17000.00
0.18
30.87
61.82
Minimum
5880.00
5.90
0.39
67.40
0.23
0.41
1070.00
8.50
0.28
4.60
7470.00
4.60
1140.00
19.20
0.02
5.80
295.00
0.37
0.81
304.00
17000.00
0.22
10.80
17.00
Maximum
25700.00
10.90
11.60
5940.00
2.20
3.10
45700.00
45.90
22.20
22.40
40800.00
4O.70
5610.00
1720.00
0.15
35.00
2550.00
1.40
1.70
1420.00
17000.00
0.29
52.90
788.00
Arithmetic
95th UCL
17796.09
4.53
6.07
738.93
0.96
0.48
4918.97
21.43
8.74
14.64
22380.37
15.01
2532.77
486.26
0.08
18.20
1246.52
0.39
0.74
749.12

0.20
33.42
92.73
Uniti
mgfcg
mg/kg
mg/kg
nrtg/kg
mg/kg
nrtg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
ug/kg
mg/kg
mg/kg
ma/kg
Organic Parameters
1.2-DICHLOROETHENE (TOTAL)
2-BUTANONE (MEK)
2-METHYL-,1-(1,1-DIMETHYLETHYL)-2-M
4.8.12-TR1METHYL-3.7.8-TRIDECATRIEN
ACENAPHTHENE
ACETONE (2-PROPANONE)
ANTrRACENE
BENZOIAIANTHRACENE
BENZOIKIFLUORANTHENE
BENZO-IBIFLUORANTHENE
B1SU-ETHYLHEXYL1PHTHALATE
CARSON DISULFIDE
CHRYSENE
CYCLOHEXANE. 1 ,1,2-TRIMETHYL
DI-N-BUTYL PHTHALATE
DI-N-OCTYL PHTHALATE
DIFTALONE
FLUORANTHENE
FLUORENE
INDENO(1,2.3-C.D)PYRENE
METHYLENE CHLORIDE
PHENANTHRENE
PYRENE
TOLUENE
TOTAL XYLENES
Total
Analyses
23
23
1
1
33
30
33
33
33
33
33
22
33
1
37
33
1
33
33
33
31
33
33
23
23
Positive
Detects
2
6
1
1
1
2
1
1
1
1
14
1
1
1
3
2
1
1
1
1
3
2
1
4
3
Detection
Frequency
9%
26%
100%
100%
3%
7%
3%
3%
3%
3%.
42%
5%
3%
100%
8%
6%
100%
3%
3%
3%
10%
6%
3%
17%
13%
Arithmetic
Mean
4.09
25.43
340.00
650.00
196.94
9.27
196.70
197.85
198.58
197.97
303.18
4.23
198.09
7.00
166.72
191.82
3000.00
201.21
196.64
197.39
8.27
194.85
201.52
29.67
4.15
Minimum
1.00
7.00
340.00
650.00
39.00
7.00
31.00
69.00
93.00
73.00
210.00
1.00
77.00
7.00
44.00
27.00
3000.00
180.00
29.00
54.00
5.00
30.00
190.00
110.00
2.00
Maximum
2.00
160.00
340.00
650.00
39.00
9.00
31.00
69.00
93.00
73.00
1200.00
1.00
77.00
7.00
51.00
43.00
3000.00
180.00
29.00
5< DO
48.00
140.00
190.00
200.00
3.00
Arithmetic
95th UCL
4.69
42.38


205.51
11.11
205.67
204.92
204.47
204.84
377.50
4.83
204.77

185.94
203.91

203.39
205.71
205.21
10.79
204.32
203.48
50.54
4.73
Units
ug/kg
ug/kg
ug/kg
ug/kg
ug/kg
ug/kg
ug/kg
ug/kg
ug/kg
ug/kg
ug/kg
ugAg
ug/kg
ug/kg
ug/kg
ug/kg
ug/kg
ug/kg
ug/kg
ug/kg
ug/kg
ug/kg
ug/kg
ug£g
up/kg

-------
                                              Table  f  11  (cont'd)

                              Chemical Constituents Identified in "Source" Samples near Well G-22
Inorganic Parameters
ALUMINUM
ANTIMONY
ARSENIC
BARIUM
BERYLLIUM
CADMIUM
CALCIUM
CHROMIUM
COBALT
COPPER
IRON
LEAD
MAGNESIUM
MANGANESE
NICKEL
POTASSIUM
SELENIUM
SODIUM
THALLIUM
VANADIUM
ZINC
Total Positive Detection
Analyses Detections Frequency
4
3
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
3
4
4
4
1
4
4
4
4
4
4
4
4
4
4
1
4
1
4
4
100%
100%
100%
100%
100%
25%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
25%
100%
25%
100%
100%
Minimun
Detected
Value (a)
16100
10
1.7
127
1.0
2.5
2520
17
7.3
12
17900
8.7
3190
208
17
1280
0.4
412
0.2
20
45
Maximum Mean
Detected Estimation
"elue (b) UCL95%
17200
10
4.2
153
1.1
2.5
3170
20
12
14
19800
21
3470
397
22
1450
0.4
586
0.2
24
72
16579
10
3.5
139
1.1
0.8
2716
18
10
13
18829
14
3329
282
19
1353
0.2
531
0.2
23
58
17183
10
7.4
153
1.1
359
3116
20
14
14
19891
28
3479
440
22
1456
0.6
673
0.2
25
77
Uniti
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
                                                                                                                         I
                                                                                                                         I
I
I

I
j]
Jj
I
J
I
I
j
Total Positive Detection
Organic Parameters Analyses Detections Frequency
1,1,1-TRICHLOROETHANE
1.1.2.2-TETRACHLOROETHANE
2-METHYLNAPHTHALENE
4-CHLORO-3-METHYLPHENOL(PCMC)
ACENAPHTHENE
BENZENE
CARBON DISULFIDE
DIBENZOFURAN
ETHYLBENZENE
FLUORENE
NAPHTHALENE
PHENANTHRENE
PYRENE
TOTAL XYLENES
4
4
4
4
4
4
4
4
4
4
4
4
3
4
1
1
4
1
1
1
1
4
3
4
4
4
2
4
25%
25%
100%
25%
25%
25%
25%
100%
75%
100%
100%
100%
67%
100%
Minimun Maximum Mean
Detected Detected Estimation
Value (a) Value (b)
3.0
16
1300
110
160
4.0
4.0
220
8.0
340
170
590
53
6.0
3.0
16
5200
110
160
4.0
4.0
1000
260
1400
1700
2100
73
180
7.1
11
2906
181
192
7.3
7.3
534
104
753
1132
1138
117
109
UCL95%
77
136
11584
295
222
51
51
2499
2.4E + 08
3220
56637
4390
1227
668
Units
ufl/Vg
ug/kg
ug/kg
ug/kg
ug/kg
ug/kg
uj/kg
ug/kg
ug/kg
ug/kg
ug/kg
ug/kg
ug/kg
ug/kg
Non-aqueous sample concentrations are based on dry weight.
Metal parameters are reported as total metals.
(a) Minimum detected value:Positive detections only.
(b) Estimation of the mean of the log normal distribution.

-------
  li
 i
 ?
 ii
 tl
 ii
 i
 4
 i
 4
 4
 4
 4
 4
 4
 4
                                         Table  # 11 (cont'd)

                           Chemical Constituents Identified in "Source" Samples near Well G-23
Inorjanic Parameters
ALUMINUM
ANTIMONY
ARSENIC
BARIUM
BERYLLIUM
CADMIUM
CALCIUM
CHROMIUM
COBALT
COPPER
IRON
LEAD
MAGNESIUM
MANGANESE
MERCURY
NICKEL
POTASSIUM
SELENIUM
SILVER
SODIUM
THALLIUM
VANADIUM
ZINC
Total Positive Detection
Analyses Detections Frequency
3
1
3
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
3
1
3
4
2
2
4
3
3
3
4
4
4
4
4
3
3
3
2
1
3
3
4
100%
100%
100%
100%
50%
50%
100%
75%
75%
75%
100%
100%
100%
100%
100%
75%
75%
75%
50%
25%
75%
75%
100%
Minimun
Detected
Value (a)
231
10
12
96
0.2
4.1
76
15
4.2
11
236
35
39
4.4
0.1
13
415
0.5
1.0
927
0.4
15
5.1
Maximum
Detected
Value
15000
10
IB
8920
0.3
8.3
10400
157
7.0
64
22400
608
1790
597
1.6
18
932
1.0
1.8
927
0.8
30
1510
Mean
Estimation
(b)
27305
10
16
13767
0.2
6.4
188 68
364
5.5
90
67308
639
3303
1880
1.0
21
1332
0.6
0.9
550
0.6
74
4235
UCt 95%
6.8E + 21
(0
27
1.1E + 11
161
1.0E + 06
3.7E + 11
2.7E + 12
223
3.4E+08
1.SE+06
393860
6.6E + 08
4.8E + 12
398
97549
2.3E + 08
7.8
13
4.0E + 06
3.7
5.9E + 08
3.2E-M2
Units
mg/kg
ing/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mgfcg
mg/kg
trig/kg


Organic Parameters
1.2-DICHLOROETHENE (TOTAL)
2-BUTANONE (MEK)
ACETONE (2-PROPANONE)
TRlCHLOROETHYLENE '

Total
Analyses
4
4
4
4

Positive
Detections
1
1
1
1

Detection
Frequency
25%
25%
25%
25%
Minimun
Detected
Value
4.0
13
7.0
3.0
Maximum
Mean


Detected Estimation
Value
4.0
13
7.0
3.0
(a)
4.2
8.1
6.3
3.9
UCL 95%
6.7
16
140
6.6
Unitt
ug/kg
ug/kg
ug/Vg
ug/kg
Non-aqueous sample concentrations are based on dry weight.
Metal parameters are reported as total metals.
(a) Minimum detected value:Positive detections only.
(b) Estimation o! the mean of the log normal distribution.
(c) UCL 95% not applicable to a population of 1.
ii
Jl

-------
                                           Table f  11  (cont'd)

                          Chemical Constituents Identified in "Source" Samples Near Boring SB-30
Inorganic Parameters
ALUMINUM
ANTIMONY
ARSENIC
BARIUM
BERYLLIUM
CADMIUM
CALCIUM
CHROMIUM
COBALT
COPPER
IRON
LEAD
MAGNESIUM
MANGANESE
MERCURY
NICKEL
POTASSIUM
SELENIUM
SODIUM
VANADIUM
ZINC
Total Positive Detection
Analyses Detections Frequency
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
1
3
3
3
2
3
3
3
• 3
3
3
3
3
2
3
3
3
2
3
3
100%
33%
100%
100%
100%
67%
100%
100%
100%
100%
100%
100%
100%
100%
67%
100%
100%
100%
67%
100%
100%
Minimun
Detected
Value (a)
10900
10
5.4
522
0.5
0.5
1880
21
1.7
12
10800
25
859
468
0.2
4.6
864
0.6
482
20
77
Maximum
Detected
Value
16400
10
7.3
4910
0.6
1.4
3310
22
5.6
15
18300
98
1250
1020
0.2
11
1130
1.0
582
34
125
Mean
Estimation
(b)
13836
6.5
6.1
2860
0.6
0.8
2567
21
3.9
14
14956
71
1052
709
0.2
8.9
1015
0.9
462
28
95
UCL 95%
22320
33
9.0
9.1E + 07
0.7
10806
5854
23
108
17
32565
7091
1629
3118
55
80
1325
1.9
1784
60
209
Units
mg/Vg
mg/kg
my/kg
mg/Vg
mg/kg
mg/Vg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg;Vg
mg/kg
mg/kg
mg/kg
mg/kg
nSVg
Total Positive
Organic Parameters
2-BUTANONE (MEK)
CARBON DISUIRDE
PHENANTHRENE
TOLUENE
TOTAL XYLENES
Detection
Analyses Detections Frequency
3
3
1
3
3
1
1
1
1
3
33%
33%
100%
33%
100%
Minimun Maximum Mean
Detected Detected Estimation
Velue (a)
27
6.0
340
4.0
2.0
Value
27
6.0
340
4.0
7.0
(b) UCL 9SS
14
4.1
340
3.3
4.3
205: i
18
(c)
4.9
145
Units
ug/kg
ug/kg
ug/kg
ug/kg
us/kg
                                                                                                                         i
Non-aqueous sample concentrations are based on dry weight.
Metal parameters are reported as total metals.
(a) Minimum detected value:Positive detections only.
(b) Estimation of the mean of the log normal distribution.
(c) UCL 95% not applicable to a population of 1.
                                                                                                                         .1
                                                                                                                         i
                                                                                                                         i
                                                                                                                         i

-------
y
M
u
u
u
ilr
4
J
J
                                                 Table  f 11  (cont'd)

                                  Chemical Constituents Identified in 'Source* Samples from Impoundment Area
Inorganic Parameters
ALUMINUM
ARSENIC
BARIUM
BERYLLIUM
CALCIUM
CHROMIUM (TOTAL)
COBALT
COPPER
IRON
LEAD
MAGNESIUM
MANGANESE
MERCURY
NICKEL
POTASSIUM
SODIUM
VANADIUM
ZINC
Total Positive Detection
Analyses Detects Frequency
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
Arithmetic
Mean
14216.67
9.17
3540.00
0.60
1790.00
29.73
9.97
14.53
16900.00
44.57
1323.33
622.00
0.14
13.33
847.33
1204.00
26.07
60.07
Minimum
6C50
4.40
2440.00
0.42
1610.00
16.50
6.80
11.50
10500.00
34.70
600.00
583.00
0.07
5.10
404.00
892.00
20.20
52.60
Maximum
20300.00
12.00
5140.00
0.74
1910.00
41.00
11.90
16.50
20100.00
58.10
1830.00
679.00
0.19
18.90
1140.00
1460.00
31.30
66.90
Arithmetic
95th UCL
26607.51
16.17
5930.11
0.88
2057.62
50.58
14.63
19.03
26243.95
65.00
2407.32
707.08
0.25
25.60
1505.S7
1689.71
35.47
72.16
Uniti
mg/kg
mrj/kg
Rig/kg
ing/kg
ing/kg
ing/kg
ing/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mo /kg
Organic Parameters
2-BUTANONE (MEK)
2-METHYLNAPHTHALENE
DIBENZOFURAN
ETHYLEENZENE
FLUORENE
NAPHTHALENE
PHENANTHRENE
TOTAL XYLENES
Total Positive Detection Arithmetic
Ana'vses Detects Frequency Mean
1
3
1
1
1
1
3
2
1
3
1
1
1
1
3
2
100%
100%
100%
100%
100%
100%
100%
100%
16.00
476.67
100.00
13.00
100.00
50.00
293.33
6.00
Minimum
16.00
180.00
100.00
13.00
100.00
50.00
180.00
3.00
Arithmetic
Maximum 95th UCL Units
16.00
660.00
100.00
13.00
100.00
50.00
480.00
9.00
ug/kg
913.80 ug/kg
ug/kg
ug/kg
ug/kg
ug/kg
567.94 ug/kg
24.94 ug/kg
4
4
4

-------
                                          Table # 11  (cont'd)

                              Chemical Constituents Identified in Background Groundwater
Inorganic Pa'.meterg
A-JMINUM
ARSENIC
BARIUM
BERYLLIUM
CALCIUM
CHROMIUM
COBALT
COPPER
IRON
LEAD
MAGNESIUM
MANGANESE
NICKEL
POTASSIUM
SELENIUM
SILVER
SODIUM
THALLIUM
VANADIUM
ZINC
Total Positive Detection
Analyses Detection* Frequency
4
4
4
4
4
5
4
4
4
4
4
4
4
4
4
3
4
4
4
4
4
4
4
1
4
4
1
3
. 4
2
4
4
2
4
1
1
4
2
1
3
100%
100%
100%
25%
100%
80%
25%
75%
100%
50%
100%
100%
50%
100%
25%
33%
100%
50%
25%
75%
Minimun
Detected
Value (a)
221
4.6
303
1.8
79900
6.2
13
7.5
4540
17
28900
678
16
2350
13
5.1
83400
1.4
47
'5
Maximum
Detected
Value
16700
41
508
1.8
87300
78
13
44
35600
18
34500
1500
35
8550
13
5.1
93800
50
47
109
Mean
Estimation
(b)
6882
16
380
0.8
82603
36
5.4
21
13156
24
30702
937
17
4215
4.3
3.2
90492
23
15
62
UCL 95%
3.1E+10
821
522
4.0
86946
5341
68
S2892
609219
1.3E+08
34091
1818
376
18196
1915
38
97117
3.5E + 08
81086
3.4E + 06
Units
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
h
ll
.V
                                                                                                                   I
                                                                                                                   If
                                                                                                                   If
Minimun Maximum Mean
Total Positive Detection Detected Detected Estimation
Organic Parameters Analyses Detections Frequency Value (a)
ACETONE (2-PROPANONE)
BIS(2-ETHYLHEXYL)PHTHALATE
CARBON DISULFIDE
DIETHYL PHTHALATE
METHYLENE CHLORIDE
4
4
4
4
4
2
3
2
1
2
50%
75%
50%
25%
50%
2.0
1.0
2.0
3.0
2.0
Value
43.0
3.0
2.0
3.0
27.0
(b)
17
3.3
2.3
5.0
11
UCL 95%
893065
21
2.7
8.3
666929
Units
ug/L
ug/L
ug/L
ug/L
ug/L
Metal parameters are reported as total metals.
(a) Minimum detected valueiPositive, detections only.
(b) Estimation of the mean of the log normal distribution.
                                                                                                                   If


                                                                                                                   If


                                                                                                                   If
                                                                                                                    I

-------
 I
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                                         Table  #  11  (cont'd)

                             Chemical Constituents Identified in Background Surface Water
Inorganic Parameters
ALUMINUM
ARSENIC
BARIUM
CADMIUM
CALCIUM
CHROMIUM
COBALT
COPPER
IRON
LEAD
MAGNESIUM
MANGANESE
NICKEL
POTASSIUM
SODIUM
VANADIUM
ZINC
Total Positive Detection
Analyses Detections Frequency
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
1
3
3
2
3
3
3
3
3
1
3
3
3
3
100%
100%
100%
33%
100%
100%
67%
100%
100%
100%
100%
100%
33%
100%
100%
100%
100%
Minimun
Detected
Value (a)
3630
2.3
99
3.7
10500
6.9
8.3
12
3050
1.8
3630
125
13
7820
4610
7.7
15
Maximum
Detected
Value
6670
3.0
150
3.7
13400
8.0
10
15
4790
4.6
4200
2170
13
9470
22600
13
76
Mean
Estimation
(bl
4921
2.6
134
2.3
11829
7.6
7.8
13
3979
3.8
3970
1233
8.5
8491
18578
10
42
UCL 95%
12323
3.4
235
25
15034
8.8
278
16
6751
43
4609
5.4E+12
44
10336
2.7E + 07
22
21939
Unite
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
Metal parameters are reported as total metals.
(a) Minimum detected velue:Positive detections only.
(b) Estimation of the mean of the log normal distribution.
No organic parameters were detected.

-------
                                            Table  # 11  (cont'd)
                                Chemical Constituents Identified in Background Surficial Soil
Inorganic Parameters
ALUMINUM
ARSENIC
BARIUM
BERYLLIUM
CALCIUM
CHROMIUM
COBALT
COPPER
IRON
LEAD
MAGNESIUM
MANGANESE
NICKEL
POTASSIUM
SILVER
SODIUM
VANADIUM
ZINC
Total Positive Detection
Analyses Dete-'iont Frequency
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
. 8
8
8
8
8
8
3
7
8
8
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
38%
88%
100%
100%
Minimun
Detected
Value (a)
8460
2.6
138
0.4
721
10
4.8
10
12500
12
739
287
4.5
724
1.2
691
24
21
Maximum
Detected
Value
14200
6.6
662
0.6
3540
17
11
14
22100
27
1260
863
10
1170
1.6
1150
41
37
Mean
Estimation
(b)
12131
4.4
290
0.5
1750
14
6.5
12
14907
18
1017
485
6.8
912
0.8
963
31
28
UCL 95%
13835
5.5
446
0.6
2978
16
7.9
13
16999
22
1149
630
8.4
1040
1.4
1467
35
31
Unit*
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
                                                                                                                        I
                                                                                                                        U
                                                                                                                        II
                                                                                                                         U
Total Positive Detection
Organic Parameters Analyses Detections Frequency
BENZCMB1FLUORANTHENE
BENZOIC ACID
3!S(2-ETHYLHEXYL)PHTHALATE
CHRYSENE
DI-N-BUTYL PHTHALATE
FLUORANTHENE
8
8
8
8
8
8
1
4
8
1
1
1
13%
50%
100%
13%
13%
13%
Minimun Maximum Mean
Detected Detected Estimation
Value !a) Value (b) UCL 95%
59
190
57
51
47
100
59
540
460
51
47
100
187
763
269
188
184
188
269
1538
804
290
289
229
Units
ug/kg
ug/kg
ug/kg
ug/kg
ug/kg
ug/kg
                                                                                                                         u
                                                                                                                         y
Non-aqueous sample concentrations are based on dry weight.
Metal parameters ere reported as total metals.
(a) Minimum detected valuf.Positive detections only.
tb). Estimation of the mean of the log normal distribution.
y
                                                                                                                         i1

-------
   J
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                                                         Table # 11 (cont'd)
                                               Chemical Constituents  Identified in Background Sediments
 J
 J
 u
 u
 LJ
Inorganic Parameters
ALUMINUM
ARSENIC
BARIUM
BERYLLIUM
CALCIUM
CHROMIUM
COBALT
COPPER
IRON
LEAD
MAGNESIUM
MANGANESE
NICKEL
POTASSIUM
SILVER
SODIUM
VANADIUM
ZINC
Total Positive Detection
Analyses Detections Frequency
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
2
4
6
6
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
33%
67%
100%
100%
Minimun
Detected
Value (e)
12700
1.4
185
0.7
2270
14
6.7
20
11200
11
1620
303
8.3
1160
1.9
1150
24
34
Maximum
Detected
Value
26000
5.6
851
1.0
3100
32
11
23
25200
33
2420
840
17
2300
2.1
2120
45
86
Mean
Estimation
(b)
17404
3.2
554
0.8
2714
20
8.7
21
15364
20
1878
499
11
1732
1.2
1340
30
62
UCL 95%
22179
5.2
1164
0.9
3016
27
10
22
20359
29
2137
692
14
2251
2.2
3027
37
85
Unite
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kr
mg/kj
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
Total Positive
Detection
Organic Parameters Analyses Detections Frequency
BEMZO(A)PYR£NE
BENZOIC ACID
BIS12-ETHYLHEXYLIPHTHALATE
DI-N-BUTYL PHTHALATE
PYRENE
6
6
6
6
3
2
3
6
3
1
33%
50%
100%
50%
33%
Minimun
Detected
Value (a)
170
230
380
81
71
vlaximum Mean
Detected Estimation
Value
210
1400
830
93
71
(b)
284
1569
628
202
339
UCL 95%
393
5512
813
533
2.3E + 06
Units
ug/kg
ug/kg
ug/kg
ug/kg
ug/kg
Non-aqueous sample concentrations are based on dry weight.
Metal parameters are reported as total metals.
(a) Minimum detected value:Positive detections only.
(b! Estimation o( the mean of the log normal distribution.
 U
 LJ
U
U
LJ
U

-------
         Table #12




POTENTIAL EXPOSURE PATHWAYS

-------
                                                       Table  //  12
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-------
                 Table #13



CARCINOGENIC POTENCIES (ORAL SLOPE FACTORS)

-------
                                      Table f 13
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-------
           Table #14



NONCARCINOGENIC REFERENCE DOSES

-------
                                               Table f 14
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               Table #15




SUMMARY OF POTENTIAL CARCINOGENIC RISKS

-------
Table # 15

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-------
               Table #17




CUMULATIVE POTENTIAL RISKS - TRESPASSER

-------
                                               Table  # 17
                    Tr««p»c«*r Cumulative Carcinogenic and Noncarcmogenic Rick Aero** Pathway*"

                                      Onaita                         Ba ck ground

Surfaca Wacar
Dermal Absorotion
Surfieial Soil
Dermal Absorotion
Surficial Soil
Ingestion
Sediment
Ingestion
Sadim«nc
Dermal Abaorotion
Cancer
Risk
5E-08
7E-07
1E-06
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0.06
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Risk
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ACSOSS PATHWAYS
                                 2E-OG
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Notes:
* Risks based on all chemicals with at least one positive detection and a verified toxiciry value.
HI =  Hazard Index (Noncarcmogenic Risk)

-------
                   Table #18



CUMULATIVE POTENTIAL RISKS - FUTURE RESIDENTIAL

-------
                                               Table  ff  18
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-------
                Table #19



CUMULATIVE POTENTIAL RISKS - OCCUPATIONAL

-------
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-------
               Table  #20




D.L. MUD RISK ASSESSMENT UNCERTAINTIES

-------
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-------
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-------
               Table #21




CHEMICALS OF CONCERN rOR SURFACE SOILS

-------
Table # 21




















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