United States .
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R09-89/039
September 1989
4>EPA Superfund
Record of Decision:
Firestone Tire (Salinas Plant), GA
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50272-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO. .
. EPA/ROD/R09-89/039
3. Recipient's AcceMlon No.
4. Title and Subtitle
SUPERFUND RECORD OF DECISION
Firestone Tire (Salinas Plant), CA
First Remedial Action - Final
5. Report Date
9/13/89
Authors)
8. Performing Organization RepL No.
9. Performing Organization Name and Address
10. Project/Task/Work Unit No.
11. Contract(C) or Grant(G) No.
(C)
(G)
12. Sponsoring Organization Name and Address
U.S. Environmental Protection Agency
401 M Street, S.W. ,
Washington, D.C. 20460
13. Type of Report & Period Covered
800/000
14.
15. Supplementary Note*
16. Abstract (Limit: 200 words)
The 256-acre Firestone Tire (Salinas Plant) site is in an agricultural area in Salinas,
California. The facility was operated as a tire manufacturing plant from 1963 to 1980,
in which a variety of chemicals and chemical formulations were used including solvents
and surfactants. In 1983, as part of the requirements for the closure of a
RCRA-regulated storage area at the facility, Firestone conducted an environmental
Investigation and determined that some chemicals had been released to the soil and
round water. Sampling indicated that a plume of VOC-contamination extends about 2 1/2
ailes northwest of the former facility. Consequently, onsite and offsite ground water
pumping and treatment was initiated to further reduce chemical migration. Furthermore,
evaluation of potential sources of contamination resulted in cleaning and removing
storage tanks and above-ground facilities, as well as excavating 5,300 cubic yards of
inorganic-'and organic-contaminated soil for final disposition offsite. This final
remedy provides for additional cleanup of ground water under the site and as much as 2
1/2 miles from the site. Soil analytical data indicated that the residual risk from
soil contamination after remedial measures had been implemented warranted no further
soil remediation. The primary contaminants of concern affecting the ground water are
VOCs including 1,1-DCA, 1,1-DCE, 1,1,1-TCA, TCE, PCE, benzene, toluene, and xylenes.
(Continued on next page)
17. Document Analysis a. Descriptors
Record of Decision - Firestone Tire (Salinas Plant), CA
First Remedial Action - Final '
Contaminated Media: gw
Key Contaminants: VOCs (1,1-DCA, 1,1-DCE, :i,l,l-TCA, TCE, PCE, benzene, toluene,
xylenes)
b. fdentifiers/Open-Ended Terms .-.'•'•
c. COSATI Field/Group
4. Availability Statement
19. Security Class (This Report) '
None
20. Security Class (This Page)
None
21. No. of Pages
327
22. Price
(See ANSI-Z39.18)
See Instructions on Revone
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-35)
Department of Commerce
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DO NOT PRINT THESE INSTRUCTIONS AS A PAGE IN A REPORT
INSTRUCTIONS
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ANSI Z39.18-1974 available from American National Standards Institute, 1430 Broadway, New York, New York 10018. Each separately
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an organizational hlerachy. Display the name of the organization exactly as it should appear in Government indexes such as
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11. Contract/Grant Number. Insert contract or grant number under which report was prepared.
12. Sponsoring Agency Name and Mailing Address. Include ZIP code. Cite main sponsors.
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14. Performing Organization Code. Leave blank.
15. Supplementary Notes. Enter Information not Included elsewhere but useful, such as: Prepared In cooperation with... Translation
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V
16. Abstract Include a brief (200 words or less) factual summary of the most significant Information contained In the report If the
report contains a significant bibliography or literature survey, mention It here.
17. Document Analysis, (a). Descriptors. Select from the Thesaurus of Engineering and Scientific Terms the proper authorized terms
that identify the major concept of the research and are sufficiently specific and precise to be used as Index entries for cataloging.
(b). Identifiers and Open-Ended Terms. Use Identifiers for protect names, code names, equipment designators, etc. Use open-
ended terms written In descriptor form for those subjects for which no descriptor exists.
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majority of documents aro rnumdiscipllnary in nature, the primary Field/Group assignments) will be the specific discipline.
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18. Distribution Statement Denote public reteasabiDty, for example "Release unlimited", or limitation for reasons other than
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22. Price. Enter price in paper copy (PC) and/or microfiche (MF) H known.
GPO: 19830-381-526(8393) OPTIONAL FORM 272 BACK
(4-77)
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EPA/ROD/R09-89/039
Firestone Tire (Salinas Plant), CA
16. Abstract (Continued)
le selected remedial action for the site includes pumping and treatment of ground water
at the existing treatment facility using carbon adsorption and air stripping, with
offsite discharging of treated ground water to surface water; ground water monitoring to
ensure that the ground water plume is declining; crop testing to ensure that there is no
plant uptake of the contaminants; and developing a contingency plan for water in the deep
aquifer in case of contamination. The estimated present worth cost for this remedial
action is $1,742,000, which includes an estimated O&M cost of $1,517,000 for 3 1/2 years.
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RECORD OF DECISION
DECLARATION »
Firestone Tire and Rubber Company, Inc. Site
Salinas, California
Statement of Basis and Purpose
The Firestone Tire and Rubber Company Site ("Firestone Site"), located in Salinas,
California, was added to the National Priorities List in 1987, and is subject to the require-
ments put forth in the Comprehensive Environmental Response, Compensation and
Liability Act. The California Department of Health Services ("DHS") approved the
remedial action for the Firestone Site in accordance with California Health and Safety
Code at 25300 et. sea.. CERCLA, the National Contingency Plan, and applicable or relevant
and appropriate requirements for the site. This document serves as EPA's selection of
remedy which fully supports the decision made by DHS. The DHS is serving as the lead
agency for Superfund activities at the Firestone Salinas Site.
EPA's selection of the remedy chosen by DHS is based upon the Remedial Action
Order, Remedial Investigation, Risk Assessment, Feasibility Study, the Remedial Action
Plan ("RAP"), the Response Summary, and the Administrative Record for this site. The
administrative record index is attached to this document, and the administrative record
file is closed with the signing of this document.
Description of Remedial Action
Firestone Tire and Rubber Company has been performing an RI/FS at the site since
1986. A RCRA closure was completed in 1984 which addressed soil contamination at the
site before the facility closed down. Firestone has been pumping and treating groundwater
at the facility since 1984 at an on-site groundwater treatment plant. Since that time,
groundwater contaminant concentrations have significantly declined.
The final remedy provides for cleanup and cleanup requirements for groundwater
under the site and extending to a distance of over 2 miles from the site. The major com-
ponents of the final selected remedy include:
0 Pumping of groundwater from the shallow 60-80 foot hydrogeological zone for
treatment;
0 Pumping of groundwater from the intermediate 120-180 foot hydrogeological zone
for treatment;
0 Treatment of extracted water by carbon adsorption and air stripping under a permit
by the Monterey Air District;
0 Discharge of treated water to the Salinas River under an NPDES permit issued by
the Regional Water Quality Control Board, San Louis Obispo Region;
0 Regular monitoring to ensure that the size of the groundwater plume is declining
and to allow for adjustments to the system;
° Crop testing to ensure there is no uptake of contaminants by plants;
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t"J. J INTERNATIONAL
I M m TECHNOLOGY Prniort Mn 1Qr,Ofi7
CJLJ CORPORATION Project NO. 13 00 6 7
- . August 1989
TT: FfRai
Feasibility Study/
Remedial Action Plan
Former Firestone Facility
Salinas, California
The Firestone Tire & Rubber Company
Akron. Ohio
Volume I - Text
RESPONSIVE TO THE NEEDS OF ENVIRONMENTAL MANAGEMENT
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- 2 -
A contingency plan for currently uncontaminated water in the deep aquifer which
becomes contaminated and is found not to be effectively remedied.
Declaration
EPA, under CERCLA, has selected this remedy for the Firestone Site. The remedy
is protective-of human health and the environment, attains Federal and State requirements
that are applicable or relevant and appropriate to the remedial action, and is cost- and
time-effective. This remedy satisfies Federal statutory preferences for remedies that
reduce toxicity* mobility, or volume of contaminants as a principal element It also utilizes
permanent solutions to the maximum extent practicable. The remedy also addresses and
provides for the 5-year review provision at CERCLA Section 121(c). If this selected
remedial action does not meet the goals and cleanup objectives identified in the remedy, or
is not sufficiently protective of human health and the environment, then EPA may, under
the authorities of CERCLA, require additional response action from Firestone.
Date John Wise
Deputy Regional Administrator
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Concurrences for Firestone Salinas Superfund Site ROD
I concur with the remedy selected by the State of California and recommend that the Deputy Regional
Administrator sign the Concurrence Record of Decision.
Hazardous Waste Management Division
j yi
Jeffrey A. Dhont
Remedial Project Manager
Enforcement Programs Section
/ V
Alexis Strauss. Chief
Superfund Enforcement Branch
Jeff Ze|jkson, Director
Jeff Iftosenbloom, Chief
Enforcement Programs Section Assistant Director for Superfund
Office of Regional Counsel
Steven Moores
Assistant Regional Counsel
Cooper
Acting Regional Counsel
David Howekamp, Director .
Water Management Division
Harry Seraydarian, Director
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FEASIBILITY STUDY/REMEDIAL ACTION PLAN
FORMER FIRESTONE FACILITY
SALINAS, CALIFORNIA
Project No. 190067
PREPARED FOR
The Firestone Tire & Rubber Company
1200 Firestone Parkway
Akron, Ohio 44301
PREPARED BY
IT Corporation
August 1989
Final Revision
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Date: 8/22/89
Final Revision^
TABLE OF CONTENTS
PAGE
LIST OF TABLES vi
LIST OF FIGURES. v11
EXECUTIVE SUMMARY ES-1
1.0 INTRODUCTION 1-1
1.1 PURPOSE OF REPORT 1-1
1.2 REGULATORY BASIS 1-1
1.3 ORGANIZATION OF REPORT 1-3
1.4 BACKGROUND INFORMATION ... . 1-4
1.4.1 SUe Description 1-4
1.4.2 Site History : 1-5
1.4.3 Environmental Fate of Chemicals at the Site 1-6
1.4.4 Residual Risk from Soil Contaminants 1-8
1.4.4.1 Introduction 1-8
1.4.4.2 Description of Soil Removal Activities
and Analytical Data 1-9
1.4.4.3 Residual Soil Levels and Their Hazards 1-14
1.5 NONBINOING PRELIMINARY ALLOCATION OF RESPONSIBILITY 1-19
2.0 IDENTIFYING AND SCREENING OF TECHNOLOGIES... 2-1
2.1 INTRODUCTION 2-1
2.2 REMEDIAL ACTION OBJECTIVES 2-1
2.2.1 Contaminants of Interest 2-1
2.2.2 Allowable Concentrations Based on Risk Assessment ... 2-2
2.2.3 Review of Applicable or Relevant and Appropriate
Requirements (ARARs) and To-Be-Considered Materials
(TBCs) 2-3
2.2.4 Summary of Allowable Concentrations 2-6
2.2.5 Development of Remedial Action Objectives 2-6
2.3 GENERAL RESPONSE ACTIONS 2-7
2.4 TECHNOLOGY TYPES AND PROCESS OPTIONS 2-9
2.4.1 Physical Treatment Methods 2-9
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Date: 8/22/89
Final Revision
TABLE OF CONTENTS
(Continued)
PAGE
2.4.1.1 Coagulation/Flocculation .................... 2-9
2.4.1.2 Oil-Water Separation ....................... 2-10
2.4.1.3 Flotation .................. ................ 2-10
2.4.1.4 Media Filtration ........................... 2-11
2.4.1.5 Absorption/Adsorption ...................... 2-12
2.4.1.6 Gas-Phase Stripping ........................ 2-16
2.4.1.7 Reverse Osmosis ............................ 2-18
2.4.1.8 Dialysis ............. . .................... . 2-19
2.4.1.9 Electrodialysis ................ ... .......... 2-20
2.4.1.10 Ultrafiltration ............................ 2-20
2.4.1.11 Freeze Processing .......................... 2-21
2.4.1.12 Distillation.. ............................. 2-24
2.4.1.13 Extraction ................................. 2-24
2.4.1.14 Mechanical Separation/Treatment ............ 2-28
2.4.1.15 Magnetic Separation ........................ 2-33
2.4.1.16 Evaporation/Crystal! ization/Drying ......... 2-35
2.4.2 Chemical Treatment Methods ........................... 2-37
2.4.2.1 Neutralization ............................. 2-37
2.4.2.2 Precipitation. ...... ....................... 2-38
2.4.2.3 Ion Exchange ............................... 2-39
2.4.2.4 Oxidation .................................. 2-40
2.4.2.5 Reduction ..... . ............................ 2-45
2.4.2.6 Photolysis ................................. 2-48
2.4.2.7 Irradiation ................................ 2-49
2.4.2.8 Stabilization .............................. 2-50
2.4.3 Biological Treatment.. ..... . ---- ........ . ............ 2-52
2.4.3.1 Aerobic Degradation ........................ 2-52
2.4.3.2 Anaerobic Digestion ........................ 2-56
2.4.3.3 Enzymatic Conversion ................ ....... 2-57
2.4.3.4 In Situ Biological Remediation ............. 2-53
FIR:0067-R3toc
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Date: 8/22/89
Final Revision
TABLE OF COKTEMTS
(Continued)
PAGE
2.4.3.5 Controlled Bacterial Applications 2-59
2.4.3,6. Composting 2-62
2.4.3.7 Aquaculture 2-63
2.4.4 Thermal Treatment..... ... 2-64
2.4.4.1 Thermal Oxidation (Incineration) 2-64
2.4.4.2 Thermal Degradation (Calcination) 2-65
2.4.4.3 Vitrification 2-65
2.4.4.4 Plasma Pyrblysis 2-66
2.4.4.5 Nuclear Destruction... 2-66
2.4.5 Dispersed Treatment 2-67
2.4.6 Centralized Treatment 2-68
3.0 DEVELOPING REMEDIATION ALTERNATIVES 3-1
3.1 RELEVANT SITE CHARACTERISTICS 3-1
3.2 EXTRACTION ALTERNATIVES 3-4
3.3 TREATMENT ALTERNATIVES 3-5
3.3.1 Activated Carbon Treatment 3-6
3.3.2 Air Stripping 3-6
3.3.3 Natural Degradation/Dilution. 3-7
3.3.4 Combined/Additional Strategies 3-3
3.3.5 Agricultural Spraying 3-8
3.4 DETAILED ANALYSIS OF DISPOSAL ALTERNATIVES 3-9
3.4.1 Alternative S - Stream Disposal 3-9
3.4.2 Alternative T - Injection 3-10
3.4.3 Alternative U - Holding Ponds, Lagoons, or Basins.... 3-11
3.4.4 Summary of Discharge Alternatives 3-12
3.5 SITE-SPECIFIC REMEDIAL ACTION ALTERNATIVES 3-14
3.5.1 Approach 3-14
3.5.2 Developed Alternatives 3-17
FIR:0067-R8toc 11J
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Date: 8/22/89
Final Revision
TABLE OF CONTENTS
(Continued)
PAGE
4.0 DETAILED ANALYSIS OF REMEDIATION ALTERNATIVES 4-1
4.1 DETAILED ALTERNATIVE ANALYSES CRITERIA 4-1
4.2 ALTERNATIVE DESCRIPTION , 4-8
4.2.1 Alternative A , 4-8
4.2.2 Alternative 8 4-10
4.2.3 Alternative C 4-11
4.2.4 Alternative D 4-13
4.2.4.1 Zone of Capture, Shallow Aquifer 4-14
4.2.4.2 Zone of Capture, Intermediate Aquifer ... 4-15
4.2.4.3 Computer Simulations. 4-17
4.2.4.4 Summary of Costs 4-19
4.2.5 Alternative E 4-19
4.3 DETAILED ANALYSIS 4-21
4.3.1 Short-Term Effectiveness 4-22
4.3.2 Long-Term Effectiveness and Permanence 4-24
4.3.3 Reduction of Toxicity, Mobility, and-Volume 4-25
4.3.4 Implementibility 4-26
4.3.4.1 Technical Feasibility 4-26
4.3.4.2 Administrative Feasibility 4-23
4.3.4.3 Availability of Services and Materials 4-29
4.3.5 Cost 4-30
4.3.6 Compliance with ARARs 4-32"
4.3.7 Overall Protection of Human Health and
the Environment 4-33
4.3.8 State Acceptance 4-34
4.3.9 Community Acceptance 4-34
4.4 SUMMARY OF DETAILED ANALYSES 4-34
5.0 RECOMMENDED REMEDIAL ACTION 5-1
6.0 RESPONSIVENESS SUMMARY 6-1
FIR:0067-R8toc iv
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Date: 8/22/89
Flna.l Revision
TABLE OF CONTENTS
(Continued)
REFERENCES
TABLES
FIGURES
APPENDIX A - REMEDIAL ACTION ORDER AND OPERATING PERMITS
APPENDIX B - PROJECT CHRONOLOGY
APPENDIX C - DATA BASE FOR CHEMICAL CONCENTRATIONS IN GROUND WATER
APPENDIX D - BASIC CONCEPTS OF ADSORPTION ON ACTIVATED CARBON
APPENDIX E - SUMMARY OF CARBON ADSORPTION CAPACITIES
APPENDIX F - AQUIFER CHARACTERISTICS
APPENDIX G - PHYSICAL AND CHEMICAL CHARACTERISTICS OF CHEMICALS
APPENDIX H - LIST OF ABBREVIATIONS AND ACRONYMS
APPENDIX I - GEOMETRIC MEAN CONCENTRATION CALCULATION METHODOLOGY
APPENDIX J - CONTAMINANT TRANSPORT SIMULATION
FIR:0067-R8toc
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Date: 8/22/89
Final Revision
LIST OF TABLES
TABLE NO. TITLE
2-1 Potential Federal Applicable or Relevant and Appropriate
Requirements (ARARs)
2-2 Potential State and Local Applicable or Relevant and
Appropriate Requirements (ARARs)
2-3 Potential Other Federal Criteria, Advisories, and Guidance
to be Considered (TBC)
2-4 Potential Other State and Local Criteria, Advisories, and
Guidance to be Considered (TBC)
2-5 Organic Constituents - Water Quality Goals-Human Health and
Welfare
3-1 Flowrates for Extraction Alternatives, Intermediate
Aquifer, Former Firestone Facility
4-1 Examination of Alternatives Versus Potentially Applicable
or Relevant and Appropriate Requirements (ARARs)
4-2 Summary of Detailed Analysis of Remediation Alternatives
*
4-3 Cost Comparison of Assembled Alternatives
4-4 Cost Summary - Alternative A
4-5 Cost Summary - Alternative B
4-6 Cost Summary - Alternative C
4-7 Cost Summary - Alternative 0
4-8 Cost Summary - Alternative E
FIR:0067-R8toc vi
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Date: 8/22/89
Final Revision
LIST OF FIGURES
FIGURE NO. TITLE
1-1 Vicinity Map
1-2 Site Plan
1^3 Well Location Map~1n Shallow Aquifer
1-4 Well Location Map in Intermediate Zone
1-5 Well Location Map for Monitoring Wells 1n Deep Aquifer
1-6 Well Location Map for Agricultural, Domestic, Industrial
and Municipal Wells in Deep Aquifer
1-7 Area 1 - Fuel Oil Storage Area, Soil Sample Locations and
Chemical Concentrations
1-8 Area 2 - Hazardous Waste Storage Area, Soil Sample
Locations and Chemical Concentrations
1-9 Area 3 - Raw Materials Storage Area, Soil Sample Locations
and Chemical Concentrations
1-10 Area 4 - Three Sludge Drying Beds, Soil Sample Locations
and Chemical Concentrations
1-11 Area 5 - Holding Ponds, Soil Sample Locations and Chemical
Concentrations
1-12 Area 6 - Seepage Ponds, Soil Sample Locations and Chemical
Concentrations
1-13 Area 7 - Transformer Yard and Waste Oil Tanks, Soil Sample
Locations and Chemical Concentrations
1-14 Area 8 - Evaporation Beds, Soil Sample Locations and
Chemical Concentrations
2-1 Technology Screening Summary - Physical Treatment Methods
2-2 Technology Screening Summary - Chemical, Biological, and
Thermal Treatment Methods
2-3 Technology Screening Summary - Technology Process Options
FIR:0067-R8toc vii
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Date: 8/22/89
Final Revision
LIST OF FIGURES
(Continued)
FIGURE NO. TITLE
3-1 Potentiometric Surface, Shallow Aquifer, March 1989
3-2 Generalized Geologic Cross Section Along Contaminant
Migration Pathways
3-3 Approximate Plume Area, Shallow Aquifer, 1,1-OCE Maximum
Concentrations, 4-88 to 3-89
3-4 Approximate Plume Area, Shallow Aquifer, 1,1,1-TCA Maximum
Concentrations, 4-88 to 3-89
3-5 Approximate Plume Area, Intermediate Aquifer, 1,1-OCE
Maximum Concentrations, 4-88 to 3-89
3-6 Approximate Plume Area, Intermediate Aquifer, 1,1-TCA
Maximum Concentrations, 4-88 to 3-89
3-7 Approximate Plume Area, Deep Aquifer, 1,1-OCE Maximum
Concentrations, 4-89 to 3-89
3-8 . Approximate Plume Area, Deep Aquifer, 1,1-TCA Maximum
Concentrations, 4-88 to 3-89
3-9 Extraction Well Locations for Pumping Alternatives
3-9a Extraction Well Locations, Pumping Alternative 1
3-9b Extraction Well Locations, Pumping Alternative 2
3-9c Extraction Well Locations, Pumping Alternative 3
3-9d Extraction Well Locations, Pumping Alternative 4
3-9e Extraction Well Locations, Pumping Alternative 5
3-9f Extraction Well Locations, Pumping Alternative 6
3-10 Extraction Well Locations, Alternative B
3-11 Extraction Well Locations, Alternative C
3-12 Extraction Well Locations, Alternative 0
3-13 Extraction Well Locations, Alternative E
FIR:0067-R8toc viii
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Date: 8/22/89
Final Revision
LIST OF FIGURES
(Continued)
3-14 Schematic Flow Diagram, Ground-Water Treatment
4-1 Model Areas
4-1A Alternative A, Plume Migration, Shallow Aquifer
4-IB- Alternative A, Plume Migration, Intermediate Aquifer
4-2A Alternative B, Plume Migration, Shallow Aquifer
4-28 Alternative B, Plume Migration, Intermediate Aquifer
4-3A Alternative C, Plume Migration, Shallow Aquifer
4-3B Alternative C, Plume Migration, Intermediate Aquifer
4-4 Capture Zone, Shallow Aquifer
4-5A Equipotential Lines, 650-GPM Capture Zone, Intermediate
Aquifer
4-5B Flowlines, 650-GPM Capture Zone, Intermediate Aquifer
4-5C Flowlines, 400-GPM Capture Zone, Intermediate Aquifer
4-6A Alternative 0, Plume Migration, Shallow Aquifer
4-6B Alternative D, Plume Migration, Intermediate Aquifer
4-6C Alternative D', Plume Migration, Intermediate Aquifer
4-6D Alternative D, Plume Migration, 400 gpm, Intermediate
Aquifer
4-7A Alternative E, Plume Migration, Shallow Aquifer
4-7B Alternative E, Plume Migration, Intermediate Aquifer
4-8 Harden 12 Ag Well 1,1-DCE Concentrations
FIR:Q067-R8toc ix
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Data: 8/22/89
Final Revision
EXECUTIVE SUKWARY
Firestone Tire & Rubber Company operated a tire-manufacturing plant from 1963
to 1980 at 340 El Camino Real South, about 6 miles southeast of downtown
Salinas, California. During operation, the plant used a variety of chemicals
and chemical formulations to make tires. Firestone began environmental
Investigations in March 1983 as part of the requirements for closing the
Resource Conservation and Recovery Act (RCRA) storage area at the facility.
Firestone subsequently determined that some chemicals had been released to the
soil and ground water. The nature and extent of these chemicals in the ground
water were thoroughly assessed and were documented in 'the Remedial
Investigation report issued to the Department of Health Services in December
1988.
As reported in the Remedial Investigation, two groups of chemicals were found
in the ground water both on and off site: chlorinated aliphatic hydrocarbons
and volatile aromatic hydrocarbons. The chlorinated compounds included the
following:
1,1-Dichloroethane (1,1-OCA)
1,2-Dichloroethane (1,2-OCA)
1,1-Oichloroethene (1,1-OCE)
1,1,1-Trichloroethane (1,1,1-TCA)
Trichloroethene (TCE)
Tetrachloroethene (PCE).
The aromatics included the following compounds:
• Benzene
• Toluene
• Ethyl benzene
• Xylene (3 isomers).
In general, the chemicals'most commonly found in the ground water in the
vicinity of the facility are 1,1-DCA; 1,1-OCE; and 1,1,1-TCA. Concentrations
are found in the micrograms per liter (parts per billion) range in on- and
off-site ground water. The seven other chemicals are found either in lower
concentrations or not at all in most wells.
t
FIR:0067-R8ES ES-1
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Date: 8/22/89
Final Revision
The ground-water aquifer system at the facility is comprised of three
interconnected zones that are designated shallow, intermediate, and deep. The
shallow aquifer extends from about 30 feet below the surface to a depth of
about 90 feet. The intermediate zone is generally between depths of about 100
and 140 feet below the surface. The deep aquifer system locally has up to
four zones at approximately 200-,,300-, 400-, and 500-foot depths.
Analyses of samples from monitoring, agricultural, domestic, industrial, and
municipal water wells indicate that the chemical plume extends about 2-1/2
miles northwest of the former Firestone facility. The plume of chemicals in
the ground water can be described as follows, starting at the facility:
• A narrow ellipse 3,000 feet long and 1,000 feet wide, in the shallow
aquifer, flowing almost due west
• A second, narrow ellipse 4,000 feet long and 1,000 feet wide, in the
intermediate zone, flowing northwest
• A third ellipse 7,000 feet long and 1,500 feet wide, in the deep
aquifer flowing northwest.
The concentrations of chemicals in the ground water have been decreasing since
monitoring began in 1983. The range of concentrations in micrograms per
liter, ug/i, from April 1988 to March 1989 was as follows:
Zone
first ellipse
second ellipse
third ellipse
Interim remedial action to clean the ground water began as soon as Firestone
was aware of the problem. Initially, extraction wells were drilled into the
shallow aquifer on site, in a line just northwest of the plant buildings. A
ground-water treatment system was installed after Firestone received approval
from State and county regulatory agencies. Subsequently, extraction wells
have been drilled off-site to the northwest, again penetrating into the
shallow aquifer.
FIR:0067-R8ES ES-2
Depth (feet)
<90
100 to 140
>200
1,1-OCE
2 to 90
NO to 52
NO to 23
1,1-DCA
2 to 36
NO to 8
NO to 11
1,1,1-TCA
1 to 38
NO to 27
NO to 16
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Final Revision
IT prepared a preliminary risk assessment relative to ground-water use for
this project in October 1988. The risk values presented in that report were
updated in the Remedial Investigation (RI) report issued in December 1988.
The risks have continued to decrease as the concentrations of chemicals 1n the
ground water are reduced by the treatment system.
Four ground-water ingestion scenarios were analyzed in the December 1988 RI
report to evaluate potential risk to humans:
° Current use of affected ground water (an existing well)
• Hypothetical well in shallow aquifer (90 feet)
• Hypothetical well in intermediate zone (120 feet)
• Hypothetical well in deep aquifer (220 feet).
In each scenario, risks from carcinogens and noncarcinogens were calculated
separately. For carcinogens, the nonsignificant risk level was set at 1 xlO~°
(one in one million) additional risk due to lifetime consumption of contamin-
ated ground water from the well. For noncarcinogens, a health index was
calculated, comparing the allowable drinking water standard with the actual
concentration in the affected ground water. The comparison is the ratio of-
actual concentration to the allowable concentration. An index value of less
than one means that the exposure level is less than the allowable human intake
level. The following table summarizes the health risk assessment results
presented in the December 1988 RI report:
HELL SCENARIO CARCINOGEN RISK HEALTH INDEX
Existing Shallow Aquifer less than 1 x 10'6 0.02
Hypothetical Shallow Aquifer 1.6 x 10"b 1.4
Hypothetical Intermediate Zone less than 1 x 10~£ 0.87
Hypothetical Deep Aquifer less than 1 x 10~° 0.2.
Based on this risk assessment, the only scenario that shows risks above the
acceptable levels is use of a hypothetical domestic well placed in the maximum
contamination point of the shallow aquifer. This is the portion of the plume
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with ground water currently being extracted and treated to reduce the
contaminant levels. The effect of continuing treatment in reducing the
concentrations was not included in the risk assessment results given above.
In addition to presenting carcinogenic risks and health indices, the risk
assessment also establishes concentrations that will protect" public health.
Preliminary health-protective tap-water concentrations were calculated for
both carcinogens and noncarcinogens. The results are as follows:
• Carcinogens
- 1,2-OCA 0.5 wgA
- TCE 3.2 ugA
- PCE 0.7 ugA
- Benzene 0.8 ugA
« Noncarcinogens • Unfactored • Factored
- 1,1-OCE 290 ugA 5.8 ugA
- 1,1-OCA 230 ugA 46 ugA
- 1,1,1-TCA 340 ugA 68 ug/i
- Toluene 120 ugA 24 ugA
- Ethylbenzene 58 ugA 11.6 ugA
- Xylene 340 ugA 68 ugA
Based on the results of this site-specific risk assessment, these concentra-
tions would be acceptable for a lifetime of daily use of the ground water.
The unfactored values for noncarcinogens are total exposure values. The
factored values incorporate a standard 20 percent factor for the contribution
from drinking water plus, in the case of 1,1-OCE, an additional uncertainty
factor of 10. These values were rounded off for presentation in the Risk
Assessment report. These health-protective values are based on the cumulative
health effects of noncarcinogens with common target organs. The numerical
values are based on the respective contributions of each compound to the
health index at the time the risk assessment was prepared. However, the
contribution to the health index for the chlorinated compounds is dominated by
1,1-OCE (93 percent) and for the aromatics by xylene (97 percent), so the
relative contributions are not expected to change significantly.
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This FS/RAP establishes cleanup criteria as follows:
,• Cleanup levels must result in a cumulative health index of less than
1 considering the noncarcinogens with common target organs.
• Cleanup levels must result in a carcinogenic risk of less than 1 x
10"° for each carcinogen.
• Cleanup levels must comply with each compound-specific applicable or
relevant and appropriate requirement.
s
For purposes of this FS/RAP and the trade-off comparisons between alterna-
tives, the health-protective levels given above were used with the compound-
specific applicable or relevant and appropriate requirements to estimate the
cleanup levels. However, the actual concentrations of each compound will be
used with\the above criteria to assess when remediation is complete.
The residual risks associated with the chemicals in the soil above the ground
water near the plant have also been assessed.
Eleven areas were identified in 1983 as potential sources of contamination.
Three of these were inside the plant, and eight were outdoors. The indoor
areas were judged not to be potential sources of contamination following
cleaning and inspection for areas of leakage. In the eight outdoor areas, the
storage tanks and above-ground facilities were cleaned and removed. The
exposed soils were tested for inorganic and organic chemicals. As a result of
this testing and visual inspections, contaminated soils were excavated and
disposed of at an off-site, hazardous-waste landfill. These removals ranged
from removal of visibly stained soil to an excavation of 5,300 cubic yards of
soil. The soil cleanup levels established in 1983 and 1984 for this work were
based on STLC and TTLC values. This FS/RAP assesses the residual risk of the
chemicals remaining in the soil after cleanup.
The chemicals remaining in the soil after the 1983-34 cleanup were
predominantly oil and grease, phthalates, and metals (predominantly zinc, as
zinc oxide, lead, and nickel). Testing showed that the oil and grease were
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not water extractable. A risk assessment considering 1ngest1on and dermal
contact with the oil and grease shows an acceptable risk. The metals are
typically at below background levels. The phthalates are at very low
levels. Considering these factors with the low potential for migration and
the fact that the areas are covered with heavy-duty truck pavement in the
middle of an Industrial park, the residual risk from soil contamination is
judged acceptable.
A variety of physical, chemical, biological, and thermal treatments were
considered to remediate the low concentrations of chlorinated hydrocarbons in
the ground water at the site. The technology screening step in the FS process
resulted in identifying carbon adsorption and air stripping as viable remedia-
tion technologies. These technologies were evaluated for both centralized
and dispersed treatment. The screening indicated that continuation of the
centralized combination of the carbon adsorption and air stripping is the
preferable technology for remediation. These are the two technologies that
have been used for the interim remedial measures at the site to date.
The remediation alternatives developed for consideration were based on the
relevant site characteristics. These included the presence of the chemicals
in both the shallow and intermediate aquifers at concentrations above health-
protective cleanup levels. In addition there is a small area in the deep
aquifer where this occurs. Computer simulation indicated that the shallow
aquifer remediation should continue. In addition, remediation should be
initiated in the intermediate aquifer.
Six alternative pumping scenarios were considered for remediating the
intermediate aquifer. These consisted of various numbers and locations of
extraction wells and pumping rates. The optimum alterative was a series of
five extraction wells aligned along the axis of the intermediate aquifer plume
pumping from 100 to 150 gpm. In addition to these pumping scenarios, three
disposal alternatives were considered. These included river discharge,
surface discharge, and injection into the shallow aquifer. Continuation of
the current river discharge was indicated as the preferable alternative.
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Five alternatives to remediate both the shallow and intermediate aquifers were
analyzed in detail. These consisted of a no-action alternative, and four
combinations of pumping from different sets of wells in the shallow and the
intermediate aquifers. Computer simulations were made of each of the five
final remedial alternatives to assess the relative effectiveness and time
required to achieve cleanup for each alternative.
The no-action alternative consists of stopping the current pumping and
treating. This alternative is presented as a baseline alternative for
comparison with the other alternatives. For this alternative the shallow
aquifer plume migrates toward the northwest, following the regional ground-
water gradient. Eventually this plume merges with the intermediate aquifer
and continues flowing with the regional gradient. Some dilution .and
dispersion occurs naturally with this alternative. The computer simulation
indicates that, for this no-action alternative, both the shallow and inter-
mediate aquifers will reach the cleanup concentrations in about 5 to 10 years.
This was used as a relative cleanup period of 1.0 for comparison with the
other alternatives.
The second remedial alternative consists of continuing to pump and treat the
ground water from the shallow aquifer. No pumping and treating is done in the
intermediate aquifer. Compared with the no-action alternative, the shallow
aquifer reaches cleanup levels in half the time; however, the intermediate
aquifer takes the same time since no remediation is done directly in the
intermediate aquifer. The reduction in mass loading from the shallow aquifer
to the intermediate aquifer has little effect on the time to reach the cleanup
levels in the intermediate aquifer.
The third remedial alternative consists of continuing to pump and treat the
ground water from the shallow aquifer. In addition, five new extraction wells
are installed in the intermediate aquifer. These new wells are pumped at
rates from 100 to 150 gpm concurrently with the ongoing pumping from the wells
in the shallow aquifer. Thus, the combined pumping rate exceeds the current
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treatment plant capacity and the current NPOES permitted flow rate.
Therefore, a new 500 gpm air stripper is added to the treatment plant for this
alternative. This also requires a new air discharge permit. This alternative
involves potential delays in obtaining the new permits as well as delays in
obtaining access to the new well locations and for a new segment of pipeline.
However, assuming these new wells can be Installed and operating by the fall
of 1989, the shallow aquifer will reach the cleanup levels In half the time of
the no-action alternative. The intermediate aquifer is projected to reach the
cleanup levels in 30% of the time required for the no-action alternative.
The fourth remedial alternative consists of continuing to pump and treat the
ground water from the shallow aquifer. In addition, five new extraction wells
are installed in the intermediate aquifer, as for the third alternative.
However, for this alternative the combined flow rates for both the shallow and
intermediate aquifer wells will be maintained below 650 gpm, the current
treatment plant capacity. Thus, no new permits, with the associated potential
delays, would be required. There are still the delays required to obtain the
access agreements for the new well locations and the new pipeline segment.
However, assuming these new wells are installed and operating by the fall of
1989, a computer simulation indicates the pumping rates can be adjusted such
that both the shallow and intermediate aquifers can reach the cleanup levels
in 60% of the time required for the no-action alternative.
The fifth remedial alternative consists of continuing to pump and treat the
ground water from the shallow aquifer. In addition, two new extraction wells
are installed in the intermediate aquifer. These new wells will be pumped at
150 gpm, and the combined flow rate from both the shallow and intermediate
aquifers will be less than 650 gpm. Thus, the treatment plant does not need
to be expanded, and no new permits are needed. Access agreements for the new
well locations and the new pipeline segment are required. Assuming the new
wells and pipeline are installed and operating by the fall of 1989, computer
simulation indicates that pumping rates can be adjusted such that both the
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Final Revision
shallow and intermediate aquifers can reach the cleanup levels in 95% of the
time required for the no-action alternative.
The recommended remedial alternative is the fourth alternative described
above. This alternative achieves the cleanup levels in only 60% of the time
required for either of the first two alternatives and 63* of the time for the
fifth alternative. The fourth alternative Is projected to take slightly
longer than the third alternative (60% compared to 50% of the no-action alter-
native time), assuming there are no delays in permitting. However, the fourth
alternative avoids the potential delays in permitting at a small Incremental
increase 1n time to achieve the cleanup levels. Thus, the fourth alternative
was selected for implementation. Each of the alternatives is comparable to
the others in terms of short-term effectiveness; long-term effectiveness and
permanence; reduction of toxicity, mobility, and volume; implementibility;
administrative feasibility; and availability of services and materials. Thus,
the relative time to achieve the clean up levels is the primary discriminator
used to distinguish among the alternatives.
FIR:0067-R8ES ES-9
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1.0
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Final Revision
1.0 INTRODUCTION
1.1 PURPOSE OF REPORT
The overall purpose of this Feasibility Study/Remedial Action Plan is to
provide the Information necessary to develop a feasible and practical con-
ceptual plan for completing the remediation of ground water at the former
Firestone facility. Interim ground-water remediation had been ongoing since
February 1986, as required by the California Department of Health Services'
(DHS) Remedial Action Order HSA 85/86-002 (Appendix A). This Feasibility
Study/Remedial Action Plan 1s to ensure that environmental, technical, and
cost-effective objectives are met.
The environmental objective 1s to perform the remediation in a manner that
will preserve and maintain the beneficial uses of regional ground water (i.e.,
domestic and agricultural uses). This objective will be met by addressing
both the quality and availability of ground water. Appropriate quality
standards are applied to protect ground water. Remediation strategies are
considered with respect to minimizing the net use of ground water.
The technical objective is to develop a remediation plan that (1) meets the
environmental, performance, and safety requirements throughout the projected
remediation; (2) includes technologies with demonstrated reliability; and (3)
is practical for the site-specific conditions as documented in the Remedial
Investigation (RI) report prepared in December 1988 (IT, 1988a).
The cost-effective objective is to optimize the cost associated with
completion of the remediation, considering both initial capital costs and
operating costs for the duration of remediation.
1.2 REGULATORY BASIS
The Remedial Investigation and Feasibility Study/Remedial Action Plan have
been submitted in two reports. The initial report was the Remedial
Investigation (RI) submitted in December 1988. The RI defined the lateral and
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vertical extent of chemicals in the subsurface, both on site and off site, and
characterized the health and environmental risks associated with them. The RI
provided the basis for the subsequent Feasibility Study/Remedial Action Plan
(FS/RAP) presented by this report. The FS/RAP evaluates various remediation
technologies and screens a variety of alternatives. It also presents a
preliminary conceptual design of the-selected remedial action together with a
schedule for implementation.
The FS/RAP was prepared to meet the specific requirements of the California
Department of Health Services' Remedial Action Order, as well as the applica-
ble requirements, orders, and guidance of the U.S. Environmental Protection
Agency (EPA), Department of Health Services (DHS), Regional Water Quality
Control Board (RWQC8), Monterey Say Unified Air Pollution Control District
(MBUAPCD), and Monterey County Health Department. Specific references include
the following:
• DHS Remedial Action Order HSA 85/86-002
• California Health and Safety Code Sections 25356.1 and 25358.7
• The Comprehensive Environmental Response, Compensation and Liability
Act of 1980, (CERCLA) 42 USC Section 9601 et seq as amended by the
Superfund Amendments and Reauthorization Act of 1986
• The National Oil and Hazardous Substances Pollution Contingency Plan,
40 CFR 300, November 20, 1985
• RWQCB Monitoring and Reporting Program No. 85-24
• RWQCB National Pollutant Discharge Elimination System Permit No. CA
0048950
• EPA Guidance Document for Conducting Remedial Investigations ind
Feasibility Studies (EPA 1988)
• DHS Site Mitigation Decision Tree
• Monterey County Health Department, Division of Environmental Health,
Permit for Construction, Repair, or Destruction of Water Wells
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Final Revision
• Monterey Bay Unified Air Pollution Control District Permit to Operate
No. 3168A and other permits to operate associated with well
development.
1.3 ORGANIZATION OF REPORT
It is not possible to conform exactly to the report format and guidance speci-
fied by each of the multiple agencies involved with this project. This report
1s Intended to satisfy the policies and guidance with respect to feasibility
studies and ground-water remediation of the involved agencies, primarily the
DHS, EPA, and RWQCB.
This FS/RAP is organized as follows:
• Executive Summary
- Summarizes the key elements of this Feasibility Study/Remedial
Action Plan
• Section 1 - Introduction (this section)
- Summarizes the background for this study and the purpose of the
FS/RAP report
• Section 2 - Identifying and Screening of Technologies
- Identifies the types of technologies and process options that were
screened for this study in terms of satisfying the remedial action
objectives and general response actions
• Section 3 - Developing Remediation Alternatives
- Describes the rationale for selecting the alternatives that were
chosen for detailed analyses with respect to evaluation for
effectiveness, implementibility, and cost
• Section 4 - Detailed Analysis of Remediation Alternatives
- Assesses the selected alternatives in terms of short- and long-
term effectiveness; permanence; reduction of mobility, toxicity,
and volume; implementibility; cost; compliance with applicable or
relevant and appropriate requirements (ARARs); overall protection;
state acceptance; and community acceptance
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• Section 5 - Recommended Remedial Action
- Summarizes the key findings 'and conclusions from the FS/RAP and
presents a conceptual plan of the recommended remedial action
• Section 6 - Responsiveness Summary
- Summarizes the comments received following the public review
period after the draft of this report 1s Issued. This section Is
not Included 1n the draft FS/RAP; 1t will be*Incorporated Into the
final FS/RAP.
1.4 BACKGROUND INFORMATION
•
1.4.1. Site Description
The former Firestone facility Is located at 340 El Camino Real South In
Salinas, California, and covers 256 acres 1n the Salinas Valley, the largest
intermountain valley in the Central Range. The valley trends northwest for
about 90 miles from Bradley to Monterey Bay and is from 5 to 10 miles wide.
The Gabllan and Diablo Mountains border the valley to the east, and the Santa
Lucia Mountains border the valley to the west. Alluvial fans and terraces
extend from the bordering mountains to the valley floor, where they are
dissected by the Salinas River, which meanders in a relatively narrow flood-
plain through the valley. Elevations of the valley floor are generally less
than 400 feet above mean sea level (msl). The area near the former Firestone
facility ranges from about 60 to 70 feet in elevation.
The agricultural lands adjacent to the former Firestone facility are plowed
and leveled on a regular basis. This flat plain is generally broken into two
areas. The area to the south-southwest of the facility is a floodplain at an
elevation of 45 feet, about 25 feet lower than the former plant. This area is
bounded on the north by an erosional bank. At the top of this bank is a dirt
farm road, locally referred to as "Scarp Road." The second area where the
higher plain is broken is along Alisal Slough. The slough is a narrow channel
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that runs northwesterly from about 3/4 mile west of the plant to Harris Road,
where it has been filled.
1.4.2. Site History
Between 1963 and 1980, Firestone Tire & Rubber Company operated a tire-
manufacturing facility located at 340 El Camino Real South, approximately 6
miles southeast of downtown Salinas, California (Figures 1-1 and 1-2).
Firestone's tire-manufacturing operation used a variety of chemicals and
chemical formulations. The following major categories of chemicals were used:
Carbon black
Styrene-butadiene rubber
Processing oils
Zinc oxide
Clay
Surfactants
Solvents
Antioxidants
Steel wire
Natural rubber
Petroleum distillate fuels.
In March 1983, Firestone began investigations at its Salinas facility to
comply with closure requirements of the facility'-s Interim Status Document,
under the Resource Conservation and Recovery Act, and of the California
Department of Health Services and the Central Coast Regional Water Quality
Control Board. Based on findings from the closure investigations, Firestone
began on-site investigations in July 1983 to characterize the nature and
extent of chemicals in both soil and ground water (Appendix B).
The findings of the early remedial investigations prompted the undertaking of
interim remedial measures for both soil and ground-water cleanuo. These
interim remedial measures have included source control and migration control.
Source control measures consisted of removing underground and aboveground
tanks and excavating and disposing of contaminated soil in an off-site Class I
landfill. At present, both on-site and off-site ground water is being
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extracted and treated to control further chemical migration and to reduce
concentrations. The remedial activities performed up to December 1988 were
described in detail in the Remedial Investigation Report submitted in December
1988 (IT, 1988a). The operating permits for these remedial activities are
included in Appendix A.
The locations of wells in the shallow aquifer and 1n the Intermediate zone are
shown on Figures 1-3 and 1-4, respectively. Figure 1-5 shows the location of
monitoring wells in the deep aquifer. The locations of agricultural,
domestic. Industrial, and municipal wells in the deep aquifer are shown on
Figure 1-6. Soil sample locations and chemical concentrations are shown in
Figures 1-7 through 1-14.
1.4.3. Environmental Fate of Chemicals at the Site
The Risk Assessment (IT, 19885) and the Remedial Investigation (IT, 1988a)
reports have both discussed the environmental fate of the chemicals at the
site. The key question addressed in those reports 1s "why has vinyl chloride
not been detected in the soils or ground water at the Firestone site in
Salinas?" This section summarizes and expands on the explanations given in
the earlier reports.
There are two classes of chlorinated solvents that were commonly used in
industry during the period the plant operated (1960s to 1980s). These are the
chlorinated ethenes, particularly perchlorethylene (tetrachloroethene, or PCE)
and trichloroethylene (trichloroethene, or TCE); and the chlorinated ethanes,
of which 1,1,1 trichloroethane (methyl chloroform, or TCA) is the only sig-
nificant representative. The former Firestone tire facility at Salinas used
TCA as the chlorinated solvent of choice.
As described in the earlier reports, sanitary landfills that apparently
received no vinyl chloride (chloroethene, or VC) have shown significant VC
concentrations in landfill gas and in liquid leachate. In some cases, VC is
not detected until several years after the landfill had been closed. Much
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research has demonstrated that these landfills indeed did not receive waste
VC, as such. Instead, the VC is produced by bacterial degradation of
chlorinated ethenes, by a step-wise process. The earlier reports provide
details, but the major features are as follows:
• Stepwlse degradation of PCE to TCE, TCE to 1,2-DCE (dlchloroethene),
and 1,2-DCE to VC
• The process requires a mildly acidic environment, such as is found in
the leachate of sanitary landfills.
• No production of 1,1-OCE (The compound found in highest concentration
at the Firestone site) occurs under such conditions.
Thus, vinyl chloride can result from biodegradation of PCE or TCE in the
environment. However, 1,1-OCE does not result from such a process.
The reports also discuss the degradation of 1,1,1-TCA, a chlorinated ethane,
in the environment. The major features are as follows:
• TCA degrades by chemical action to acetic acid and hydrochloric acid,
and also produces some 1,1-DCE in the process. The 1,1-DCE yield is
about 20 percent of the total TCA degraded.
• Biodegradation processes producing 1,1-OCE from 1,1,1-TCA have also
been reported. The by-product of these is hydrochloric acid. In
addition, 1,2-OCA (dichloroethane) is reportedly produced in TCA
biodegradation. It is also known to be a contaminant of commercial
grade TCA. Some 1,2-OCA is found in ground water at the site.
• These processes operate in an alkaline environment. Hence, the vinyl
chloride degradation process described for chloroethenes will not
operate (since it requires an acidic environment).
i
• Any acetic acid and hydrochloric acid produced will be neutralized by
the generally alkaline medium of the site ground water. The quanti-
ties of these acids produced are exceptionally small (in the tens to
hundreds of ppb range), and so the residual anions would not be
detectable against background. Further, other bacteria probably will
decompose acetate to C02 and H20.
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In summary, compounds such as PCE and TCE can be degraded 1n the environment
to vinyl chloride. The process requires an acidic environment and operates
via anaerobic bacteria. These conditions, while found In municipal solid
waste and sanitary waste landfills, do not exist at the former Firestone site
In Salinas. Further, the solvent that was used, lsl»l=trichloroethane,
degrades to I,l-d1chloroethene by processes that operate 1n an aerobic,
alkaline environment. These are the environmental conditions In the soil and
ground water at the site. Therefore, vinyl chloride 1s not expected to be
found In ground water at the former Firestone facility 1n Salinas.
1.4.4. Residual Risk from Soil Contaminants
1.4.4.1. Introduction
In 1983-84, Woodward-Clyde Consultants (WCC) carried out an intensive soil
Investigation and removal action in 9 areas of the Firestone-Salinas
facility. Interim cleanup criteria were developed by OHS and/or by WCC. The
soil cleanup levels were based on the soluble threshold limit concentrations
(STLC) and total threshold limit concentrations (TTLC), which are values
proposed by the State to determine 1f wastes containing bioaccumulative or
persistent (B/P) toxic substances are hazardous.
The parameters used to establish the 1983 cleanup levels at the Firestone
facility were determined after considering that over 50 individual elements
and compounds were found in the soil, but only 11 were found in measurable
concentrations in near-surface ground water. The concentrations in ground
water were at levels 100 times less than the concentrations in the soil. This
indicates that the rate and extent of leaching into the ground water has been
very low for most of the soil contaminants.
WCC proposed at that time to establish the following soil cleanup levels:
• Organics: Soil concentration twice STLC
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• Metals: Soil concentration equal to 50 percent of the TTLC.
The proposed soil cleanup level for metals was based on a DHS request that
lead (Pb) in soil at another site being investigated by WCC be reduced through
soil removal to 500 mg/Kg (50 percent of TTLC).
Initial soil and ground-water analyses were conducted for priority pollutants,
metals, oil and grease, total organic carbons, total organic halogens,
phthalates, and polynuclear aromatic hydrocarbons. The primary chemicals
identified in the soils were (Woodward-Clyde Consultants, 1984a):
1,1-dichloroethene (1,1-OCE) • benzene
1,1-dichloroethane (1,1-OCA) • ethylbenzene
1,2-dichloroethane (1,2-DCA) • toluene
1,1,1-trichloroethane (1,1,1-TCA) • xylene
trichloroethene (TCE) • oil and grease
tetrachloroethene (PCE).
Table 3-1 of the Remedial Investigation report (IT, 1988a) lists STLCs and
TTLCs for all the additional chemicals found in the soil.
Based on. the analytical results from the Initial studies, the following
chemicals were identified for future testing and have been the basis for risk
assessment and the ongoing ground-water monitoring program (IT, 1988a):
1,1-OCE , 1,1,1-TCA
1,1-OCA v benzene
1,2-OCA toluene
TCE xylene
PCE ethylbenzene
1.4.4.2. Description of Soil Removal Activities and Analytical Data
The following 11 areas at the Firestone site were investigated in 1983 and
1984, during the initial phase of the project:
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OUTDOOR AREAS INDOOR AREAS
Fuel Storage Area, Area 1 Banbury Pits
Courtyard, Area 2 Curing Room
Raw Materials Storage and Utility Trenches and
Rallcar Unloading, Area 3 Outdoor Corridor
Sludge-Drying Beds, Area 4
Holding Ponds, Area 5
Seepage Beds, Area 6
Waste Oil Storage and
Transfer Yard, Area 7
Evaporation Ponds, Area 8
-- . •
Each area was evaluated against the interim cleanup levels for each chemical
and/or material. Where necessary, mitigation activities were undertaken to
meet the interim soil clean-up levels.
Chemicals detected in the indoor areas were found in sludges and residues
remaining after the plant shutdown. After the residuals were removed, these
indoor areas were cleaned. The floors were inspected for signs of possible
leakage, such as cracked, broken, or deteriorated concrete. No cracks or
other signs of leakage were found and, thus, the areas were judged not to be
potential sources of ground-water contamination.
The following is a summary, by area, of the type of contamination found at
each of the outdoor areas, and of the type of remedial activities undertaken.
Details of the analytical results before and after mitigation activities are
presented in Woodward-Clyde's 1984 report. Also, for areas 3, 4 and 7, native
soil excavation work was required. Analytical results are given for soil
samples taken after completion of this remedial work.
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Fuel Oil Storage - Area 1
This area contained eight underground fuel oil storage tanks. No detectable
levels of fuel components or PCB contaminants were found. Oil samples from
the tanks were found to contain 3 to 4 ppm of Aroclor 1260, a polychlorinated
biphenyl (PCB) compound. After removal of the tanks, no PCB soil or ground-
water contamination above the detection limits of 0.5 ug/z for soil, and
0.1 ug/i for water, was found. No remediation was done in this area, and
after tank removal", this area was considered to be properly closed.
Courtyard - Area 2
During the plant operation the courtyard was a multipurpose area used for
maintenance and storage with a cooling pond and a hazardous waste storage
area.
The surface soils in the hazardous waste storage part of the courtyard
contained low levels of several organic compounds (phthalate esters and
polynuclear aromatics). Metals in the 100 to 200 ppm range were found in the
east-west ditch and the cooling tower ditch. Soil from the ditches and an area
outside of the door to the main building was removed to a depth of 6 to 18
inches and disposed of at a Class I hazardous waste disposal facility. After
removal of this soil, remaining levels of organics and inorganics were found
to be at background levels and below the cleanup levels prescribed in the OHS
Remedial Action Order, and in the February 29, 1984 letter from DHS to
Firestone.
The area does not constitute a threat to public health or ground water and no
further remedial action was required. This area was accepted as properly
closed.
Raw Materials Storage - Area 3
Raw materials used at the plant were transported to Area 3 by train and truck
and stored in 11 underground steel storage tanks, with capacities ranging from
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5,000 to 14,000 gallons. Materials that were stored 1n the tanks Included
gasoline, kerosene, acetone, hexane, wax, pine tar, naphtha, aromatic oil, and
various antioxidants. The area formerly contained a silo for storing carbon
black. Numerous soil and ground-water samples were collected in this area and
analyzed for priority pollutants, metals, oil and grease (O&G), total organic
carbon (TOC), and total organic halogens (TOX). Various chemical substances
were found In greater numbers and at higher concentrations 1n the soil and
ground water in this area than in any other area sampled during the Initial
investigation (Woodward-Clyde Consultants, 1984a).
An extensive cleanup of this area was carried out, including removal of all
underground storage tanks, removal of soil in two phases (Phases A and 8), and
treatment of ground water. Phase A involved removal of all plant equipment,
piping and tanks, and removal of the contaminated soil to a depth of 3 to 6
feet. Samples taken from the upper 18 inches of soil at the bottom of the
excavation showed no VOCs, with the exception of 3.4 ppm of ethyl benzene in
one sample. Oil and grease was still present (2,800 ppm) and chromium and
zinc were detected at levels of 53 and 73 ppm.
In phase B, the area of highest contamination was excavated to a depth of 40
feet, and 5,300 cubic yards of soil were removed. After backfilling with
clean soil an 8-inch asphalt cap was put in place. Subsequently, concrete has
been placed over some of this area as well. During the Phase B excavation
work, a soil sampling and testing program was carried out on the excavated
soils. Inorganics were below background levels. Individual organic species
were detected only in parts-per-billion concentrations. Oil and grease, found
at levels of about 5,000 ppm, did not contain water extractable organic
constituents.
Sludge-Drying Beds - Area 4
This area contained three ponds that served as drying beds for sludge from the
industrial wastewater treatment plant. No volatile organic compounds were
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detected in the six soil samples taken in these beds, one each at the surface
and at a depth of 4.5 feet in each pond. Phthalates were found at concen-
trations up to 4.6 ppm. Metal concentrations were generally at background
levels.
Oil and grease concentrations as high as 63,000 ppm were detected in all the
deeper (to 36 feet) soil samples, teachability tests with water showed no
detectable oil and grease 1n the water. The only remedial work performed in
this area was removing 12-18 inches of contaminated top soil and replacing it
with clean backfill.
Holding Ponds - Area 5
The two ponds in Area 5 were used to hold storm-water runoff that exceeded the
capacity of the industrial wastewater treatment plant. No volatile compounds
were found in the six soil samples taken at depths up to 14 feet, or the two
ground-water samples, taken at depths of 25 feet to 35 feet. No orgam'cs or
metals were found in the ground water; no soil remediation was required,
based on observed soil concentrations. This area was considered properly
closed.
Seepage Beds - Area 6
Area 6 contained two seepage ponds that received treated water from two
sources - the sewage treatment plant and the industrial wastewater treatment
plant. The results of the analyses showed the presence of phthalates and
hexane in soil at the 1 ppm level and xylene at 0.1 ppm. The values of the
metals, with the exception of zinc, lead, and nickel were below STLC and TTLC
values. The observed values for lead, zinc, and nickel were well below the
recommended interim cleanup levels developed by Woodward-Clyde. No remedial
action for these areas was recommended based on the lack of potential impacts
on public health or the environment.
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Waste-011 Storage and Transformer Yard - Area 7
Area 7 contained three tanks used for the storage of various processing
materials. An above ground tank in the southern part of the yard was used to
store caustic soda/rubber latex. A burled tank and the above ground tank in
the northern part of the yard were used for the storage of waste oils.
An approximately I0-foot-d1ameter discolored area 1n the southeastern portion
of the yard was also Investigated. Two soil samples were collected from the
excavated area after the tanks were removed. No volatiles were detected, but
low levels of phthalates were found. Metal concentrations were below back-
ground, and no further remedial work was performed 1n this area.
Since no contaminants were detected at the site, after removing the tanks and
any visually stained surflclal soils, no remedial program was necessary for
the transformer yard. This area was considered to be clean.
Evaporation Ponds - Area 8
Area 8 contained three ponds that were used for storing excess storm water
runoff before the Industrial wastewater treatment plant was built. No
detectable volatile compounds were found in the three surface soil samples
analyzed; low phthalate concentrations were detected. Metal concentrations
were below background levels and lead and nickel were far below the interim
cleanup levels.
This area did not appear to represent a threat to public health or the
environment. As a result, it was recommended that this area not receive
further investigation and be considered as properly closed.
1.4.4.3. Residual Soil Levels and Their Hazards
The investigations of the various source areas, Areas 1 through 8, conducted
in 1983 and 1984 showed that inorganic chemical concentrations in soils in
Areas 1, 2, 5, 6, 8 were at or below background levels; thus, these areas did
not require remedial measures. "Background" means the average range of
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inorganics found in the earth's crust (EPA-OSWERSW-874, April 1983). Remedial
measures were required and subsequently implemented at Areas 3, 4 and 7,
where the soils left in place contained low levels of some volatile or semi-
volatile organic compounds. In many cases, significant levels of "oil and
grease" were detected (concentrations in the 1,000 to 50,000 ppm range). In
each case, the oil and grease was extracted with deionized water, and the
extracts tested for oil and grease. In all such extracts, no organics were
detected. The soil analytical data from the initial investigations indicated
that no further soil remediation was required. Therefore, all subsequent
interim remediation activities were directed solely toward ground water.
The soil cap and asphalt or concrete covers also prevent downward infiltration
of rainwater. Human access to, and direct exposure to the remaining soil is
not probable. The shallow aquifer has dropped several feet below the level in
the original areas (1 through 8) of chemical contamination. Migration to
ground water is thus unlikely. Regional flow in the shallow aquifer moves
from south of the site to the northwest. An extensive array of ground-water
monitoring and extraction wells covers possible flow paths away from the plant
area. Ground-water monitoring results since 1985 demonstrate that no organic
compounds are entering on-site ground water from these yard areas. The
existing on-site monitoring and extraction wells have not detected any
remaining source of soil contaminants, entering the ground water from the
zones that have been remediated (Zones 3, 4 and 7) and from all the other
zones (Zones 1, 2, 5, 6, and 8).
Specifically, for the soils remaining in the eight areas investigated, the
potential residual risks to human health and the environment are described
below:
Area 3 - Raw Material Storage
After the excavation in Phase A and Phase B and the removal of the
contaminated soil, the residual soil left at the bottom of the excavated areas
had the following highest observed concentrations: (in mg/kg).
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Oil and Grease
Ethylbenzene
Chromium
Zinc
Benzene
Xylenes
Methyl Cyclohexane
Phase A
2800
3.4
53
73
NO
NO
NO
Phase B
4100
0.026
NO
NO
0.033
0.11
0.22
Drainage Ditch
470
NO
38
53
NO
NO
NO
The BTX plume (Benzene, Toluene, Xylene) appeared to be confined to the
section of Area 3 adjacent to the cement house. This plume appeared to be
somewhat limited due to the retardation properties of the thick clay layer
underlying this section. The mobility of the volatile organic compounds
(benzene, toluene, xylene and ethylbenzene) in soil is controlled by several
geochemical factors, such as the following:
• Sorption; by natural soil organic matter and by oil and grease
• Biodegradation; in near surface aerobic zones and also underground
under anaerobic conditions
• Two-phase Flow; because of variations in density in the different
media.
To conclude, the potential existence of some VOC's under the building near
area 3 appears to have been limited by the low migrating capabilities of the
organic components in question. If a significant amount of VOC had been left
under the building it should have been detected by the active ground-water
monitoring wells. But none has been observed in over five years.
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The oil and grease observed in the residual soil left at the bottom of the
excavation has a very low potential impact on health and environment. The
same factors affecting the mobility of VOC's affect in a larger manner the
mobility or migratory tendencies of the larger molecules of oil and grease.
The only possible exposure to these contaminants is by dermal contact and/or
by soil ingestion. The toxicity of oil and grease 1s very low, with a TDLo
(Tumor Dose-Low) 1n the gm/kg range (grams of substance per kg of body
weight).
According to the California Site Mitigation Decision Tree Manual (1985) the
Department of Health Services (DHS) developed Applied Action Levels (AALs)
criteria to evaluate and, if necessary, to mitigate the impact of uncontrolled
hazardous waste sites on the public health and the environment. When soil is
the medium of exposure, two routes, ingestion and dermal contact, are
addressed in developing AALs. A reasonable and conservative estimate of the
average daily soil ingestion is 0.15 g/day, and an estimate of the average
daily soil exposure by dermal contact is 0.45g/day (Sedman, 1989).
The TDLo values for heavy oils (RTECS 1983) range from 1 to 10 g/Kg, or 70 to
700 grams per day for an adult. At an average daily exposure (ingestion plus
contact) to 0.6 grams of soil, and a maximum of 6500 ppm oil and grease, the
daily dose would be:
Dose = 65000 ug/g x 0.6 g/day = 39 mg/day.
This dose is l/2000th to 1/20,000th of the reported TDLo.
Another insight into the relatively low hazard of oil and grease comes from
the measured soil concentrations of polynuclear aromatics (PNA) at the
facility. Generally, each sample showed two or three PNAs, at most, in
concentrations of 10 to 20 ppb. Ratioing these with the maximum 65000 ppm oil
and grease level found, this is about equal to 1 ppm total PNA in the oil and
grease. This corresponds to 1 ug per gram of oil and grease. With the 39 mg
daily dose calculated above, the average daily exposure to PNAs would be:
PNA dose = 1 ug/g x .039 g/day = 0.04 ug
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A daily dose of 0.04 wg benzo(a) pyrene equivalent represents an insignificant
risk to human health. This is particularly true because there is no credible
scenario whereby an individual could receive a 70 year exposure to material
burled under clean soil in the middle of an industrial park.
The inorganic level in the residual soil 1s at nominal soil background levels
with the exception of zinc (Zn). This metal 1s present only as zinc oxide
(ZhO) which is harmless. It is 1n fact used in medicinal preparations (zinc
oxide ointment) and is classified by the Food and Drug Administration as GRAS
(Generally Regarded as Safe).
Area 4 - Sludge Drying Beds
The residual soil left 1n the top layer removal of Area 4 show the following
level of contamination (in mg/kg):
Oil and Grease 63,000
Cr 42
Pb 6
N1 55
Zn 110
Phthalates (3) 0.112
Phenanthrene & Naphthalene 0.011
BEHP (a phthalate ester) 4.6
The same considerations given to the impact of oil and grease for Area 3 are
applicable to this area.
The metals, except zinc, are at background level. Again, zinc is found in the
harmless zinc oxide form.
The phthalates measured in the samples do not appear to result from
Firestone's activities. The manufacture of tires did not include the use of
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these compounds. Phthalates are used mostly as plastidzers In the production
of polyvlnyl chloride (PVC) film. Soil samples were collected and placed 1n
plastic baggies (made of PVC) and most probably were contaminated by the
phthalates 1n the bags.
The oil and grease at Area 4, burled under one to two feet of fill, does not
pose a significant threat to human health or the environment, as discussed for
Area 3.
Area 7 - Waste 011 Storage/Transformer Yard
After removal of the two storage tanks and of the soil that showed
discoloration, no further action was required. The residual soil left in the
area has only low concentration of metals and phthalates. Again, there 1s no
apparent risk to health.
1.5 NONBINDING PRELIMINARY ALLOCATION OF RESPONSIBILITY
Upon consideration of all the evidence, the Department of Health Services
concludes that the preliminary non-binding allocation of financial
responsibility 1n this RAP 1s as follows:
Firestone Tire & Rubber Company 100%
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2.0
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2.0 IDENTIFYING AND SCREENING OF TECHNOLOGIES
2.1 INTRODUCTION
The California Site Mitigation Decision Tree Manual (DHS, 1986) and the
National Oil and Hazardous Substances Pollution Contingency Plan (EPA, 1985a)
each require a stepped approach to identifying and screening technologies to
be used for remedial action at contaminated sites. Following characterization
of specific site problems and contaminant pathways, the procedures in these
documents require identification of general response actions that can meet the
remedial response objectives. In general, these objectives can be met by
implementing any of a variety of actions. This section presents a discussion
of the remedial response objectives, general response actions to satisfy these
objectives, and potential technologies that can be used in implementing these
actions.
2.2 REMEDIAL ACTION OBJECTIVES
2.2.1 Contaminants of Interest
As discussed in Section 3 of the RI report, six chlorinated hydrocarbons and
four aromatics have been Identified in the monitoring program for this site.
These chemicals are as follows:
CHLORINATED HYDROCARBONS AROMATICS
1,1-Dichchloroethane (1,1-DCA) Benzene
1,2-Oichchloroethane (1,2-QCA) Toluene
1,1-Dichloroethene (1,1-DCE) Ethylbenzene
1,1,1-Trichloroethane (1,1,1-TCA) Xylene (3 isomers)
Trichloroethene (TCE)
Tetrachlorothene (PCE)
However, an examination of the geochemical monitoring database for the five
affected • agricultural wells, the one affected domestic well, and the one
affected inactive well shows that the actual chemicals of interest are fewer
than this. (Affected well is used here to indicate a well where chemicals
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have been detected on a repeatable basis since the monitoring began.)
1,2-OCA; PCE; and the aromatics have not been repeatedly detected in any of
these wells. Further TCE has not been detected in these wells, except for
Harris B, since September 1986. Thus, the primary chemicals of Interest are
1,1-DCA; 1,1-DCE; and 1,1,1-TCA.
2.2.2 Allowable Concentrations Based on Risk Assessment
A key finding of the risk assessment prepared for this project (IT, 1988b) is
establishing ground-water concentrations that protect public health and the
environment. These health-protective levels were established by back-
calculating from a carcinogenic risk criterion of a one in one million
(1 x 10" ) hazard, or a noncarcinogenic index criterion of one, to a chemical
concentration at a domestic-use tap. These health-protective levels and the
maximum contaminant levels (MCL) respective values in ug/i are as follows:
Health-Protective
• Carcinogens Levels MCLs
- 1,2-OCA 0.5 0.5
- TCE 3.2 5
- PCE 0.7 5
- Benzene 0.8 1
Health-Protective Levels
• Noncarcinogens Unfactored Factored MCLs
- 1,1-DCE 290 6 6
- 1,1-DCA 230 50 5
- 1,1,1-TCA 340 70 200
- Toluene 120 20
- Ethyl benzene 58 10 680
- Xylenes (3 isomers) 340 70 1,750
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Based on the results of this site-specific risk assessment, these concentra-
tions would be acceptable for a lifetime of daily use of the ground water.
The unfactored values for noncarcinogens are total exposure values. The
factored values incorporate a standard 20 percent factor for the contribution
from drinking water plus, in the case of 1,1-OCE, an additional uncertainty
factor of 10. These values have been rounded off.
2.2.3 Review of Applicable or Relevant and Appropriate Requirements (ARARs)
and To-Be-Considered Materials (TBCs)
CERCLA Section 121 requires selection of a remedial action that is protective
of human health and the environment. EPA's approach to determining protec-
tiveness involves a risk assessment, considering both applicable or relevant
and appropriate requirements (ARAR) and To-Be-Considered (TBC) materials.
CERCLA remedial actions that leave any hazardous substance, pollutant, or
contaminant on site must meet, upon completion of the remedial action, a level
or standard of control that at least attains standards, requirements, limita-
tions, or criteria that are applicable or relevant and appropriate under any
Federal environmental law and State environmental or siting law that is more
stringent than Federal requirements. Furthermore, many State laws give
enforcement authority to agencies. These local agencies develop regulations
that codify State requirements. As a result, some local regulations can also
be ARARs.
The EPA Office of Solid Waste and Emergency Response (OSWER) issued Directive
9234.0-05 on July 9, 1987 and published an essentially identical document
entitled "Interim Guidance on Compliance with Applicable or Relevant and
Appropriate Requirements (ARARs)" (EPA, 1987). These guidance documents
address Comprehensive Environmental Response, Compensation, Liability Act
(CERCLA) requirements that remedial actions comply with ARARs of Federal and
more stringent promulgated State laws. OSWER Directive 9234.1-01 "CERCLA
Compliance with Other Laws, Manual, Draft Guidance" (EPA, 19886) issued
August 8, 1988, and 40 CFR Part 300, "The National Oil and Hazardous
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Substances Pollution Contingency Plan, Proposed Rule" (EPA, 1988c) provided
additional information on ARAR Identification and compliance as well as
defining to-be-considered (TBC) material.
ARARs are defined in the interim guidance document (EPA, 1987) as follows:
Applicable requirements means those cleanup standards, standards of
control, and other substantive environmental protection requirements,
criteria, or limitations promulgated under federal or state law that
specifically address a hazardous substance, pollutant, contaminant,
remedial action, location, or other circumstance at a CERCLA site.
Relevant and appropriate requirements means those cleanup standards,
standards of control, and other substantive environmental protection
requirements, criteria, or limitations promulgated under federal or
state law that, while not "applicable" to a hazardous substance,
pollutant, contaminant, remedial action, location, or other circumstance
at a CERCLA site, address problems or situations sufficiently similar to
those encountered at the CERCLA site that their use is well suited to
the particular site.
A requirement may be either one of these categories but not both. There is
more discretion in the determination of relevant and appropriate requirements;
it is. possible for only part of a requirement to be considered relevant and
appropriate in a given case. When the analysis results in a determination
that a requirement is both relevant and appropriate, such a requirement must
be complied with to the same degree as if it were applicable.
In addition, the draft guidance manual (EPA, 1988b) and the proposed NCR rule
revisions (EPA, 1988c) define To-Be-Considered materials as follows:
To-Be-Considered Materials (TBCs) are nonpromulgated advisories or
guidance issued by federal or state government that are not legally
binding and do not have the status of potential ARARs. However, in many
circumstances TBCs will be considered along with ARARs as part of the
site risk assessment and may be used in determining the necessary level
of cleanup for protection of health or the environment.
ARARs will define the cleanup goals when they set an acceptable level
with respect to site-specific factors. Cleanup goals for some
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substances may have to be based on nonpromulgated criteria and
advisories [for example, health advisories such as reference doses
(RFD)j rather than on ARARs because ARARs do not exist for those
substances or because an ARAR alone would not be sufficiently protective
in the given circumstance, e.g., where additive effects from several
chemicals are involved. In these situations, the cleanup requirements,
in order to meet the cleanup goals, will not be based on ARARs alone but
also on TBCs.
ARARs (and TBCs to some extent) may be classified into categories as follows,
although not all ARARs will fall neatly into this classification system:
Ambient or chemical-specific requirements are usually health- or risk-
based numerical values or methodologies which, when applied to site-
specific conditions, result in the establishment of numerical values.
These values establish the acceptable amount or concentration of a
chemical that may be found in, or discharged to, the ambient
environment.
Performance, design, or other action-specific requirements are usually
technology- or activity-based requirements or limitations on actions
taken with respect to hazardous wastes.
Location-specific requirements are restrictions placed on the concentra-
tions of hazardous substances or the conductance of activities solely
because they occur in special locations.
The initial step for identifying ARARs and TBCs involved reviewing appropriate
lists of potential ARARs and TBCs and comparing them to the site condition
and/or potential remedial activities. The NCP proposed rule (EPA, 1988c)
lists examples of potential Federal and State ARARs and TBCs in 53 FR 51447 to
53 FR 51450 in the preamble section to the proposed rule. Potential ARARs and
TBCs are presented and discussed in "CERCLA Compliance with Other Laws,
Manual, Draft Guidance" (EPA, 1988b). Additionally, a copy of all Federal and
State ARARs currently identified by the DHS was provided (DHS, 1989). These
sources of information were reviewed and compiled with site-specific informa-
tion to generate Tables 2-1 to 2-4. . Table 2-1 presents Federal ARARs;
Table 2-2 presents State and local ARARs; Table 2-3 presents Federal TBCs; and
Table 2-4 presents State and local TBCs.
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Contaminant-specific ARARs and TBCs were developed for the ground-water
contaminants of interest observed at or near the facility as part of the Risk
Assessment (IT, 1988b). Possible requirements, standards and criteria related
to water quality goals for organic constituents to provide protection for
human health and welfare were summarized in Table 4-2 of the Risk Assessment.
However, since that report was issued DHS revised the drinking-water action
levels and the maximum contaminant levels. The revised values (as of April
1989) are shown in Table 2-5.
Examples of location-specific ARARs Include floodplain and wetland regulations
for modification or installation of discharge lines. National Pollutant
Discharge Elimination System (NPOES) permits and the Monterey Say Unified Air
Pollution Control District (MBUAPCD) permit to operate are somewhat location
oriented in that use-attainability studies for surface waters and attainment
status of regional air quality have an impact on permit limitations.
Action-specific ARARs are discussed in detail in relation to alternative
screening and detailed analyses in Sections 3.0 and 4.0.
2.2.4 Summary of Allowable Concentrations
The ground-water cleanup levels used in this FS/RAP are the lower of the
concentrations based on the health-risk assessment, considering the cumulative
health risks, and the concentrations based on the ARARs discussed in the
previous two sections. In general, the concentrations based on the health-
risk assessment are the lower concentrations; however, for benzene and 1,1-DCA
the State drinking water action level ARARs are lower. Thus, the cleanup
levels in ug/z, are as follows:
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Final Revision
• Carcinogens Clean-up Levels
- 1,2-DCA 0.5
- TCE 3.2 . ,
- PCE 0.7
- Benzene 0.7
• Noncarcinogens
.. - *
- 1,1-DCE 6
- 1,1-OCA 5
-1,1,1-TCA 70
- Toluene 20
- Ethyl benzene 10
- Xylene 70
2.2.5 Development of Remedial Action Objectives
The remedial action objectives for the former Firestone facility operable unit
are based on the current knowledge of the site and on the results of the
preliminary risk assessment. The current knowledge of the site is summarized
in the Remedial Investigation (IT, 1988a) as updated in the latest geochemical
database, Appendix C. The Preliminary Risk Assessment (IT, 1988b) was updated
in the RI. Key response objectives are as follows:
• To control migration of chemicals from the shallow aquifer into the
intermediate and deep aquifers where the water is being used for
agricultural and some domestic purposes
• To maintain the quality of ground water downgradient of the former
Firestone facility suitable for agricultural and domestic use.
Related objectives include the following:
• To restore the quality of the shallow aquifer 'to meet State drinking
water action levels
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Final Revision
• To provide actions that will minimize" adverse impact on the current
use of the ground water in the area
• To provide actions that are consistent with the intent of current
operating permits for the existing treatment plant
• To provide actions that protect the health of the workers and
residents in the vicinity of the site.
2.3 GENERAL RESPONSE ACTIONS
The feasibility study procedures followed by both California and EPA specify
identifying general response actions (DHS, 1986; EPA, 1988a; EPA, 1985b).
From the inception of the studies at the Firestone site, the following general
response action categories have been identified:
Air pollution controls
Surface-water controls
Ground-water controls
Gas migration control
Waste removal
Contaminated soil excavation
Land disposal
Temporary storage
Control of Abeloe well contamination.
The air pollution controls apply to the airstripper at the treatment plant.
These will continue throughout the use of the airstripper. The surface-water
controls currently apply to the discharge from the treatment plant into the
Salinas River. . These controls will continue throughout the use of the
treatment plan. Ground-water controls are a significant part of the ongoing
interim remediation. Currently, these controls include source control by
limiting the ground-water flow containing chemicals from the shallow aquifer
into the intermediate zone. In addition, these controls include hydrogeologic
containment of flow in the shallow aquifer.
Gas migration control was exercised when the soil-gas extraction system was
operating. Currently, this is not an operable general response action.
Likewise, waste removal was performed when the plant was closed but is not
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operable currently. Therefore, waste removal is not an operable general
response action.
Contaminated soil was excavated during the early remediation efforts at the
site, as discussed in the remedial Investigation report. This contaminated
soil was disposed of at a licensed Class I hazardous waste landfill.
Currently, there is no soil excavation or land disposal from the Firestone
site so these are not operable general response actions. Temporary storage of
chemicals occurred when the facility was being closed. Currently, there is no
temporary storage at the site associated with the Firestone operations.
The water quality in the Abeloe well initially exceeded the State drinking
water action level for 1,1-OCE. However, the State and EPA subsequently
reevaluated the toxicity of 1,1-OCE and raised their allowable limits. Thus,
control of this water is not currently a general response action.
The current general response actions and those foreseeable in the future are
used in conjunction with site-specific problems and viable pathways to focus
subsequent remedial alternative evaluation. They also must be used in con-
junction with the remedial action objectives and the allowable exposures based
on the risk assessment and the ARARs discussed above to develop a range of
treatment and containment alternatives that satisfy these criteria.
General response actions applicable to the Firestone site are as follows:
No action
Pumping on site
Pumping off site
Partial removal
On-site (centralized) treatment
Off-site (dispersed) treatment
Off-site disposal.
/
In accordance with the September 24, 1987, letter from Firestone to DHS
(Firestone Tire & Rubber Company, 1987), this feasibility study is to be
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focused on the chemicals in the ground water. Also, the no action alternative
becomes a shutdown of the existing system rather than a "do nothing" scenario
because there has already been substantial remediation.
2.4 TECHNOLOGY TYPES AND PROCESS OPTIONS
This section briefly describes technology types and process options.
Physical, chemical, biological, and thermal treatment methods are summarized.
Figure 2-1 presents the physical treatment methods, and Figure 2-2 presents
the chemical, biological, and thermal treatment methods discussed in this
section. An overview of technology process options is presented in Figure
2-3.
2.4.1 Physical Treatment Methods
2.4.1.1 Coaqulation/Flocculation
The application of coagulatlon/flocculation involves the controlled addition
of chemical agents such as alum or polymers. The action of these agents
serves to create a second phase by transforming a suspension of ultrafine
particles into coagulated material or floes of larger particles (Berkowitz et
al, 1978, page 503). The floes may then be easily separated by gravity,
thickening, skimming, filtration, or centrifugation. This technology is
suitable for treatment of waste streams containing suspended solids.
Coagulation/flocculation would not be an effective treatment method for the
low concentrations of organic constituents found in the Firestone Salinas
ground water. Thus, no further consideration will be given to this treatment
method for implementation at the Firestone Salinas site.
2.4.1.2 Oil-Water Separation
Oil-water separation technology combines chemical addition, temperature con-
trol, and a variety of engineered vessel designs to enhance oil-water sepa-
ration. Separator vessel designs may be a series of baffled chambers
i
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(American Petroleum Institute-type), or a single vessel that is heated and
mildly agitated. Coalescers are vessels with plates or packing to enhance the
collection and recovery of ultrafine oil particles. Chemical addition and pH
adjustment are frequently used in addition to aid in separation, to speed
coalescing action, or to aid in breaking down of emulsions that may form.
Heating may be performed to reduce viscosity and enhance the separation of
emulsions.
Free oil product may be removed from the separator by manual skimming with a
pump or vacuum truck. Wicking ropes or belts are often used for continuous
skimming of surface oil from separator tanks or basins. Simply allowing
gravity overflow of accumulated oil may be the most convenient way to remove
the free product from a separator. Oil-water separation technology is only
effective for separation and removal of free organic product, emulsified
product, or dissolved product when concentrations are at or near saturation.
Oil-water separation would not be effective for treating the low concentra-
tions of synthetic organics found in the Firestone Salinas ground water.
Thus, no further consideration will' be given to this treatment method for
implementation at the Firestone Salinas site.
2.4.1.3 Flotation
Flotation is a technology that has been developed primarily for the separation
and concentration of mineral ores (Berkowitz et al., 1978, pp. 535-536). This
technology involves the controlled dispersion of a fine air stream through a
slurry. The air bubbles attach themselves to suspended solid particles (in
the case of mining, preferentially to ore particles). The bubbles rise to the
surface where a floe forms. A raking device skims the surface of the
flotation tank, removing the accumulated floe. The floe is then collected for
further processing or disposal. The aqueous phase is decanted, disposed, or
recycled. The process usually operates in a continuous mode. Waste treatment
applications have included cardboard fiber reclaiming, municipal sludge
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thickening, and water clarification. This technology is only applicable to
the separation of slurries (two phases).
Flotation would not be effective in treating the low concentrations of dis-
solved synthetic organics in the Firestone Salinas ground water. Thus, no
further consideration will be given to this treatment method for implementa-
tion at the Firestone Salinas site.
2.4.'l.4 Media Filtration
This technology involves passing a contaminated waste stream through a fixed
(stationary) matrix (such as sand, dolomite, or fabric), which provides rela-
tively uniform pores for physical trapping or retention of a portion (particu-
late phase) of the waste stream. Media filtration, as referenced in this
section, applies to matrices providing pore diameters greater than one micron.
Media filtration does not include media that have adsorpti've capability such
as activated carbon, zeolites, ion exchange resins, or oil-adsorbing media.
Chemically active or reactive media, such as stationary catalyst beds or fixed
stationary enzymes, are also excluded since their primary function is not to
provide a barrier but to perform a chemical transformation. Membrane-type
treatment technologies, such as reverse osmosis, are also not included under
Media Filtration. These methods are referenced in other sections (refer to
Section 2.4.1.7, Reverse Osmosis; Section 2.4.1.8, Dialysis; Section 2.4.1.9,
Electrodialysis; Section 2.4.1.10, Ultrafiltration). Media filtration is
only capable of removing contaminants greater than one micron in size. This
technology is not effective in removing Tiolecular contaminants such as synthe-
tic organics.
Media filtration would be ineffective for treatment or removal of the chemi-
cals found in the Firestone Salinas ground water. However, the technology
could be appropriate for pretreatment to remove suspended solids, silts, and
clays that may be in the ground water pumped to the surface. No further
consideration will be given to this method for implementation as a primary
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treatment method at the Firestone Salinas site. Pretreatment of Firestone
Salinas ground water has not been required to date. All extraction wells have
been thoroughly developed to minimize intrusion from suspended solids.
2.4.1.5 Absorption/Adsorption
The two categories of absorption/adsorption (Northwestern Carbon, 1988) are
physical adsorption and chemlsorption. These two processes will be discussed
separately.
*
These two processes will be discussed separately.
Physical Adsorption
Physical adsorption is a surface phenomenon involving weak van der Waals
forces, differing from absorption, which by definition is penetration of one
substance into the bulk of another (Weist, 1975). The forces involved in
physical adsorption are similar to. those responsible for surface tension in
liquids. Physical adsorption as referenced in this section takes place
between a solid adsorbent and a liquid or gas containing, adsorbable species.
(Liquid-liquid absorption is discussed in Section 2.4.1.13.) Adsorbents
possess a very high internal surface area which prov'des the sites for
adsorption to take place (at the molecular level). Adsorption is a reversible
process because of the weak van der Waals forces involved. Adsorbents can be
regenerated using solvents, steam, heat, or other methods depending on the
species that is adsorbed. There are many different useful adsorbents used in
chemical processing and waste treatment; these include acid-treated clay,
activated alumina, alumino silicates, bone char, Fullers earth, iron oxide,
magnesia, -silica gel, and carbon (Mark et al., 1985). Clays are most commonly
used as oil adsorbents. They are particularly effective against free oil or
micro emulsions, for which activated carbon would be. ineffective, rapidly
depleted, or uneconomical. Often clays are used as a pretreatment of the feed
to a carbon system. The other adsorbents listed have limited use in waste
treatment applications, except for iron oxide. The application of iron oxide
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in waste treatment is discussed in more detail in- Section* 2.4.2^5 under
Electrolytic Oxidation/Reduction.
Activated carbon adsorption is the primary adsorbent used in waste treatment
today. The following technologies use activated carbon:
• Granular Activated Carbon Treatment (GAC)
• Powdered Activated Carbon Treatment PACT" (PACT" 1s a registered
trademark of Zimpro Corporation).
These methods will be discussed individually.
Granular Activated Carbon Treatment
Carbonaceous, material such as coal, wood, coconut shells, or petroleum pitch,
when subjected to controlled oxidation (in a kiln) under a reducing atmo-
sphere, can be "activated," producing a high quality, effective adsorbent.
The activation process serves to burn out some of the carbon, creating an
intricate internal structure within the carbon matrix. The internal structure
is characterized by a very high internal surface area. High grade activated
carbons have over 1,000 square meters of Internal surface area per gram. An
in-depth discussion of the concepts of activated carbon adsorption may be
found in Appendix D.
Granular activated carbon treatment is one of the preferred methods for
economical removal of low concentrations of a wide variety of small to medium
size organic molecules. Larger molecules (such as oil) are not as readily
adsorbed because these molecules do not fit well into the internal pores of
the activated carbon (the pore sites being where adsorption occurs). Small
molecules, however, diffuse readily into the pores and are held by the weak,
attractive van der Waals forces. Different compounds are adsorbed more
readily than others. This scale depends on a variety of factors including
molecular size, structure, the carbon type and pore size, and the heat (or
energy) of adsorption. The heat of adsorption is generally equivalent to.the
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heat of condensation (gas to liquid phase change) of the adsorbed species.
Experimentally measured adsorption capacities have been determined for various
compounds. A summary of the test procedures to determine carbon adsorption
capacities and a summary of carbon adsorption capacities for a variety of
chemicals are provided 1n Appendix E.
Granular activated carbon treatment 1s most economical for removing low
concentrations of organics. The higher the Influent waste concentration, the
more quickly the carbon is exhausted. Waste streams containing organic
concentrations up to 100 ppm can be economically treated using activated
carbon. Streams up to 10,000 ppm can be economically treated, provided regen-
eration of the carbon in place is possible. Vapor-phase solvent recovery
using activated carbon is one application where activated carbon is used for
treatment of high concentrations of organics. The activated carbon is usually
steam regenerated and the solvent recovered by decanting or distillation.
Vapor-phase organic adsorption on activated carbon has to be carefully moni-
tored to prevent bed fires resulting from the heat evolved by adsorption.
Activated carbon treatment is technically appropriate for treating the ground
water at the Firestone Salinas site. Carbon is especially well suited for
removing the very low concentrations of chlorinated organics and producing a
very high purity effluent stream. Further evaluation will be performed on
this method in combination with other options in Section 3.0.
PACT*
Powdered activated carbon treatment is a process that uses pulverized acti-
vated carbon in conjunction with biological treatment to produce very high
reductions of biological oxygen demand (BOO) (99*) and chemical oxygen demand
(COD) (9056). PACT" reduces odor and toxicity and improves effluent color over
/
conventional waste-treatment processes (Zlmpro, 1984). PACT™ is a process
licensed to Zimpro Inc.
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PACT™ treatment involves addition of powdered carbon to the effluent of a
primary clarifier in a waste treatment plant. The mix is sent to an aerated
basin where further biological action takes place and toxics are adsorbed onto
the carbon. The effluent from the basin flows to a secondary clarifier where
the carbon and sludge are settled out and removed from the bottom of the
clarifier. The carbon is recovered, regenerated, and sent back to the
clarifier. Sludges are separated and further treated or disposed. The over-
flow from the secondary clarifier 1s ready for discharge or may be filtered to
remove any trace carryover solids. Carbon recovery is in the 80 to 90 percent
range. The process is effective in removing low levels of industrial organic
wastes and solvents that find their way into municipal waste streams (Zimpro,
1984).
The process is somewhat capital intensive and is generally intended for large-
scale waste-treatment operations treating greater than 1 million gallons of
wastewater per day.
PACT" technology would not be appropriate for treatment of the Firestone
Salinas ground water. Since granular activated carbon treatment alone has
proved to be adequate, the capital cost for the additional combined biological
treatment capability provided by PACT" would not be justified (since biologi-
cal treatment is only marginally effective against chlorinated organic hydro-
carbons). Thus, no further consideration will be given to this treatment
method for implementation at the Firestone Salinas site.
Chemisorption
———— . 5
Chemisorption is primarily an absorption process using chemicals, solvents, or
chemically treated media to absorb materials from a waste stream. The process
relies on solvation or chemical reaction and the formation of strong chemical
bonds as compared to the weak forces driving physical adsorption processes.
Chemisorption processes may proceed by adsorption at the surface interface
then absorbed as reactions and diffusion into the bulk mass takes place.
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Chemisorption processes are not as easily reversed as physical adsorption
processes, especially if the bonds formed are extremely strong. Examples of
Chemisorption in waste treatment are the use of limestone or sodium carbonate
to remove sulfur dioxide from stack gases. Anhydrous materials such as copper
sulfate or concentrated sulfuric acid are used as chemical agents to remove
water from gas streams. In refinery processing, alkanolamines are used in
sour gas scrubbing towers to remove carbon dioxide, hydrogen sulfide, and
carbon disulfide from sour refinery gas (Dow Chemical Company, 1980).
Chemisorption would be ineffective in treatment or removal of the chlorinated
organics in the Firestone ground water. Chlorinated organics are relatively
inert and nonreactive. Thus, no further consideration will be given to this
treatment method for implementation at the Firestone Salinas site.
2.4.1.6 Gas-Phase Stripping
The three gas-phase stripping processes that have application to waste
treatment are as follows:
• Air stripping
• Steam stripping
• Alternate gas stripping.
These three processes are discussed in the following subsections.
Air Stripping
Air stripping is a commonly used method for removal of volatile organics from
water. Air stripping, similar to distillation, is a mass transfer process
that depends on the favorable equilibrium for the transfer of dissolved
volatile components from the liquid into the gas phase. A variety of differ-
ent methods can be used to enhance the mass transfer rate such as spraying
(spray ponds), aeration towers (with plates), or packed stripper columns. The
purpose of spraying, plates, or packing is to enhance mass transfer by
providing intimate contact between the air and liquid (the same function
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plates perform in a distillation tower). The volatile components in the
liquid will transfer to the gas phase, providing a continuous supply of fresh,
uncontaminated air is kept in contact with the liquid (Kavanaughy, 1980).
Packed stripper columns have advantages over other enhanced air stripping
methods. Packed columns provide multiple equilibrium stages giving the high-
est mass transfer efficiency. Forced air draft 1n a stripper column can be
adjusted to provide the optimum a1r-liqu1d ratios for removal of particular
volatile chemical species. Packed columns can also be used to perform pre-
treatment before another operation such as activated carbon adsorption.
The advantages of air stripping in waste treatment are the low treatment cost,
high efficiency for volatile organic removal, simple operation, and compact-
ness for treatment of large volumes. Air strippers for ground-water treatment
•
are most economical in locations where direct discharge to' the atmosphere is
allowable.
Air stripping is a treatment method that has been proven efficient and cost
effective in removing volatile organic contamination in ground water (Shukla
and Hicks, 1984). The removal of the chlorinated organic hydrocarbons in the
Firestone Salinas ground water by air stripping has been demonstrated as a
very effective treatment method. Air stripping will be evaluated further in
Section 3.0 as a suitable treatment method for implementation of the Firestone
Salinas site.
Steam Stripping
Steam stripping is a waste treatment method using saturated steam injected in
a liquid stream to remove volatile components. The same general mass transfer
principles apply to steam stripping as for air stripping.
Steam stripping is confined within closed tanks or columns to control heat
transfer losses. A closed tank with a steam sparger will serve as a sincle-
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staged steam stripper. Columns with plates or packing provide multiple equi-
librium stages greatly increasing efficiency. The primary advantage of steam
stripping is the operation at higher temperature (of the saturated steam)
increases the vapor pressure of volatile organic contaminants and decreases
the solubility of dissolved gases in the liquid phase. In addition, pH
adjustment may be used to further decrease the solubility of certain acid or
basic gases such as ammonia or hydrogen sulfide. This method provides
extremely high removal efficiencies for many organlcs, Including many which
are not easily removed by simple air stripping.
The major disadvantage of steam stripping 1s energy consumption. The feed
must be preheated to near the temperature of the saturated steam. The high
heat capacity of aqueous solutions becomes a major economic concern when
comparing energy and capital costs of competitive treatment processes.
Steam stripping would be effective in removing the organic contamination in
the Firestone Salinas ground water. However, 1t has been demonstrated that
air stripping is an effective treatment method. The added cost of using steam
would provide no additional benefit. Thus, no further consideration will be
given to this treatment method for implementation at the Firestone Salinas
site.
Alternate Gas Stripping
Alternate gas stripping is gas phase stripping of waste-containing liquids
using a supplied gas other than air or steam. Gases used may include carbon
dioxide or nitrogen. This method of stripping might be used when air would
form flammable or explosive mixtures with the waste material (thus requiring
an inert atmosphere for safety). Use of an alternate gas for stripping might
also be appropriate when the energy economics of using steam stripping prevent
its use as an inerting agent (steam is an effective oxygen stripper). An
inert gas may also be required when the materials involved require inerting
but are heat or water sensitive (eliminating the option of using steam).
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Alternate gas stripping might be used economically when a chemical reaction
with the gas aids stripping efficiency, such as using carbon dioxide to strip
and acidify a waste stream.
Alternate gas stripping would be effective in removal of the organic contami-
nants in the Firestone Salinas ground water. However, there is no additional
benefit to offset the added cost of supplying an inert alternate gas. Simple
air stripping has proven safe and effective for removing the chlorinated
organic hydrocarbon contamination. Thus, no further consideration will be
given to this treatment method for implementation at the Firestone Salinas
site.
2.4.1.7 Reverse Osmosis
Reverse osmosis technology employs a semipermeable membrane to achieve ionic
size separations. The membrane is maintained under a sizable pressure gradi-
ent to achieve concentration of dissolved organic and inorganic species.
Influent is pumped to the reverse osmosis unit at a pressure of between 300
and 600 psi. Flow is maintained tangential to the membrane surface by using a
tubular configuration to support the membrane. As a result of continuous
flushing (due to tangential flow), the membrane does not become plugged as
does a media filter (which has flow normal to the media).
Reverse osmosis treatment generates two streams, a clean permeant and a
concentrated reject stream. Reverse osmosis treatment does not destroy or
eliminate contaminants but concentrates them in the reject stream. The reject
stream must then be further treated or disposed. The generation of the reject
stream may be a drawback of implementing this treatment method. Concentration
of the waste stream up to 75 percent is possible in one pass. Multiple units
in series are able to further concentrate the waste stream; however, there are
limits that affect the performance and integrity of the reverse osmosis
membrane. Reverse osmosis can be used for producing very concentrated streams
when combined with other technologies such as distillation. The reverse
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osmosis process cannot tolerate suspended solids, requiring pretreatment to
prevent membrane fouling or damage. Membranes are also susceptible to
chemical attack, fouling, and damage from other species including oil, grease,
iron and manganese salts, particulates, and bioorganics (such as algae)
(Berkowitz et al., 1978, page 834). Volatile organics may cause membrane
swelling and permanent damage to the reverse osmosis membranes.
Capital costs are high for large capacity systems, the major cost item being
the membranes themselves. Energy consumption is low to moderate. The major
energy requirement is to drive the high pressure feed pump. Reverse osmosis
is more economical for concentrating dilute streams than evaporation or
distillation.
Reverse osmosis is an unsuitable treatment method for the Firestone Salinas
ground water due to the potential membrane damage that may occur from treating
chlorinated synthetic organics. Thus, no further consideration will be given
to this treatment method for implementation at the Firestone Salinas site.
2.4.1.8 Dialysis
Dialysis is another membrane separation technology. The membranes used are
semipermeable, which allow salts and small organic molecules to pass freely
through while higher molecular weight species are retained (concentrated).
The process relies on simple diffusion with the concentration gradient across
the membrane as the driving force.
Dialysis is best suited for use in treatment of concentrated solutions (5 to
20 percent). Also, the membranes can be sensitive to solvents, which may
cause them to swell or degrade. The best applications of this method are for
purification of caustic or nonoxidizing acid solutions containing low mole-
i
cular weight organics. The production rate of dialysis is relatively low
compared to other methods (Berkowitz et al., 1978, pp. 347 and 349). Dialysis
generates a concentrated reject stream that may require further handling or
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Dialysis would be ineffective for treatment or removing the low concentrations
of organics in the Firestone Salinas ground water. Thus, no further consid-
eration will be given to this treatment method for implementation at the
Firestone Salinas site.
2.4.1.9 Electrodialysis
Electrodialysis uses ion-exchange-type membranes to separate Ion-containing
solutions into dilute and concentrated streams by application of a dc electric
current across a selectively permeable membrane. The membranes are permeable
to only one type of ion charge (anions or cations). Application of a current
causes Ions to migrate toward the respective anode or cathode. Blocked by the
selectively permeable membrane, ionic species concentrate on one side of the
membrane or the other. The method is totally ineffective for nonionized or
noncharged species. Also the most effective and productive operating range is
for solutions whose ionic concentration is between 200 and 5,000 ppm
(Berkowitz et al., 1978, pp. 406-407).
Electrodialysis would be ineffective for treating the low concentrations of
organics in the Firestone Salinas ground water. Thus, no further considera-
tion will be given to this treatment method for Implementation at the Fire-
stone Salinas site.
2.4.1.10 Ultrafiltration
This technology employs a porous membrane that behaves similar to a fixed- or
stationary-media filter. A pressure gradient of 10 to 100 psi is maintained
across the membrane, producing a concentrated reject and dilute permeate
stream. The pore sizes of Ultrafiltration membranes are much smaller than
typical media-type filters. Ultrafiltration membranes will retain large
molecules (greater than 1,000 molecular weight), colloids, and suspended
solids while allowing water molecules, ions, and small organic molecules to
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pass through. Membranes can be tailored to specific applications (pore sizes)
such as removal of viruses or higher molecular weight organics in the 10 to
1,000 Angstrom range (Berkowitz et al., 1978, page 899). This method
generates a concentrated waste stream that may require additional handling or
treatment (typical of all membrane separation technologies). The membranes
are generally not restrictive to low molecular weight organics, and the
membranes may be sensitive to chlorinated synthetic organic solvents (which
may cause swelling or degradation).
Ultrafiltration would be ineffective for treatment or removal of the low
levels of chlorinated organics in the Firestone Salinas ground water. Thus,
no further consideration will be^given to this treatment method for implemen-
tation at the Firestone Salinas site.
2.4.1.11 Freeze Processing
The following methods of freeze processing may have application to waste
treatment:
• Freeze crystallization
• Freeze crying
• Suspension freezing
• Zone refining.
Each of these is discussed in the following subsections.
Freeze Crystallization
This treatment method relies on the phase change that occurs when mixtures
containing dissolved solids are frozen. The crystals that first form as a
solution is cooled are pure relative to the remaining liquid. These pure
crystals may then be removed mechanically, washed, and recovered. The
remaining solution is now concentrated with the undesired impurities. The
method is most effective for treating solutions containing a 1 to 10 percent
concentration of dissolved species. The only commercial application of this
technology is for producing fresh water from salt water.
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The disadvantages of this method are high energy consumption (as a result of
requiring refrigeration), removing, washing, and handling the frozen product,
and the high concentration range required to be effective (Berkowitz et al.,
1978, pp. 552-553).
Freeze crystallization would be Ineffective for treating the low^level organic
contamination in the Firestone Salinas ground water. Thus, no further
consideration will be given to this treatment method for implementation at the
Firestone Salinas site*
Freeze Drying
Freeze drying is a process for removing water and volatiles from aqueous
mixtures containing solids or dissolved solids. The process involves freezing
the mixture, then pulling a high vacuum to sublime the water and remove any
volatiles. The remaining solid material is essentially dry without having to
be subjected to any heat. This method may have value in dewatering chemically
sensitive materials. This process is used commercially to produce freeze
dried coffee and other dried foodstuffs. Avoiding the use of heat to recover
food products prevents thermal degradation and preserves flavor. The freeze
drying process might be applied to the dewatering sludges; however, the added
cost of providing the necessary refrigeration usually prevents its use in
favor of other more economical methods.
Freeze drying would not be a cost-effective treatment method for the Firestone
Salinas ground water. Thus, no further consideration will be given to this
treatment method for the implementation at the Firestone Salinas site.
Suspension Freezing
It has been observed that the freezing and thawing of some sludges and gela-
tinous materials aid in the agglomeration and separation of solids. The
freezing causes suspended solids to floe, and when thawing occurs, the floe
separates from the solution. The effect is believed to be as a result of
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pressure exerted on sludge particles by the formation of ice crystals. This
treatment has been found to be effective on all types of municipal treatment
plant sludges. However, this process has only been demonstrated in the
laboratory. The requirement for refrigeration would probably make it
competitive only in climates where winter temperatures provide natural
refrigeration.
Suspension freezing would not..be an effective method for treatment or removal
of dissolved organlcs 1n the Firestone Salinas ground water. The process has
only been demonstrated effective for the separation of sludges. Thus, no
further consideration will be given to this treatment method for implementa-
tion at the Firestone Salinas site.
Zone Refining
Zone refining is a melt/refreeze method used to produce ultrapure metals,
inorganics, and organic materials. It is costly and only suitable for
treatment of small batches of material. The principal of zone refining .is
phase equilibrium, similar to freeze crystallization or distillation. When a
melted mixture cools, the crystals that form have a composition different from
the original mixture. The solid phase is enriched with the less volatile
components, opposite of distillation where the vapor phase is enriched with
the more volatile components. The process is usually applied to already pure
materials. A rod of material is passed through a heater (usually inductive
heating for metals). The heater melts a small portion or zone in the rod. As
the rod is moved forward through the heater, the molten zone moves down the
length of the rod. The impurities tend to stay in and be carried by the
molten zone. Repeating the process a number of times results in the produc-
tion of an ultrapure rod. This technique has use in the high technology and
semiconductor industries where ultrapure materials are required and the cost
is justified. There are no viable applications for waste or hazardous waste
treatment due to the economics (Berkowitz et al., 1978, pp. 910-916).
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Zone refining is not applicable to waste treatment or ground-water treat-
ment. Thus, no further consideration will be given to this method for
implementation at the Firestone Salinas site.
2.4.1.12 Distillation
Distillation is a well known technology for separating mixtures of pure liqu.id
components. The method relies on the difference 1n volatilities of the
components of a mixture and the equilibrium those components reach in the
vapor phase at varying temperatures. Heating a mixture enriches the vapor
phase with the more volatile component. Condensing this vapor phase produces
a volatile-rich liquid. Repeating this process 1n a multlstaged distillation
column allows for separation of components that may have only slight
differences in boiling point (although this may require a large number of
equilibrium stages). Distillation is best suited when concentration of the
feed to a nominal purity is acceptable. Production of ultrapure distillate or
highly concentrated bottom material may require several hundred equilibrium
stages, high reflux rates and large columns. This results in high capital
cost and high energy consumption when large feed volumes must be handled.
Also, distillation of aqueous solutions 1s especially energy intensive due to
the high heat capacity of water.
Distillation would be effective but uneconomical for treatment of the low
concentrations of organics in the Firestone Salinas ground water. Thus, no
further consideration will be given to this treatment method for implementa-
tion at the Firestone Salinas Site.
2.4.1.13 Extraction
The following five types of extraction methods have application to waste
treatment:
• Liquid-liquid extraction (referred to as solvent extraction)
• Liquid-solid extraction (referred to as leaching)
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• Liquified gas extraction
• Supercritical fluid extraction (referred to as supercritical fluid
oxidation)
• Gas-11quid extraction (referred to as stripping).
The first three of these methods are discussed 1n more detail below. The
latter two of these methods are discussed In Sections 2.4.1.6, Gas-Phase
Stripping, and,2.4.2.4, Oxidation.
Liquid-L1qu1d/Solvent Extraction
Solvent extraction technology uses an immiscible solvent in contact with a
second .olvent containing a dissolved species (solute) that is to be recov-
ered. An immiscible solvent is selected that has a great affinity for the
solute. Intimate contact induced by vigorous agitation or in a designed,
staged contactor allows for the transfer of the solute from one solvent to the
other based on favorable equilibrium. After contact, the two immiscible
solvent phases separate, allowing for recovery of the solute and either reuse
or disposal of both solvents. The major advantage of this method is that,
with the proper choice of an extraction solvent, only a relatively small
volume of extraction solvent is required to recover the solute from a very
large volume of influent. This process can be significantly more energy
efficient than direct recovery by methods such as distillation. Proper
application of solvent extraction technology concentrates the solute, often by
orders of magnitude, with very low energy expenditure.
The major inherent problem with this technology for environmental applications
is finding an extraction solvent that is not in itself environmentally sensi-
tive. Organic solvents that are immiscible with water are all slightly water
soluble to some degree. TJus contamination may make return of treated ground
water or wastewater to the environment impossible without additional
treatment.
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The potential* environmental concerns associated with liquid-liquid extraction
and the availability of much more acceptable and effective technologies make
this method unsuitable to treat the low levels of organic contamination in the
Firestone Salinas ground water. Thus, no further consideration will be given
to this treatment method for Implementation at the Firestone Salinas site.
Liquid-Solid Extraction/Leaching .
The two types of leaching mechanisms are so1vat1on and chemical reaction.
Since these two methods are applied identically, they will be discussed
together.
The following are the four types of leaching processes:
• Batch
• Continuous
• Heap or pile
• In situ (solution mining).
All these processes involve contacting a liquid with a solid, resulting in the
selective removal of a portion of the solid material, either by solvation or
chemical reaction.
To differentiate between solvation leaching and chemical leaching, an example
of each is given. The leaching of coffee with water is an example of solvent
leaching. Certain coffee solids and oils are solvated (dissolved) by the
water, producing the extracted cup of coffee. Alternatively, the leaching of
gold from ore using mercury metal is an example of chemical leaching. The
mercury chemically reacts with the pure gold particles in the ore to form an
amalgam.
There are many different arrangements of batch and continuous leaching equip-
ment, processes, and vessels. Leaching may be'performed in a single tank or
vessel with an agitator to mix the solids and leaching liquids. A continuous
multi-staged extraction system may be used to increase efficiency and yield by
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providing multiple recovery stages, reflex of leachate liquid, filters,
settlers, etc. Extraction, being an equilibrium process, is governed by
fundamental mass-transfer principles, the same as distillation and air
stripping.
Heap leaching is a common method used in mining. Large mounds of ore are
placed on an impervious surface such as clay, a concrete slab, or plastic
lining. Leaching liquid sprayed on the mound percolates through the solid
mass. The enriched leachate is recovered at the bottom of the mound and
processed to recover the desirable material. This method 1s sometimes used in
waste treatment to treat contaminated soils. An example of heap leaching is
the treatment of cyanide-leached ore piles (formerly leached for gold and
silver) which have been left with residual cyanide. Solutions of oxidizing
agents are sprayed on the contaminated mound, chemically leaching out the
cyanide as cyanate or allowing the reaction to go to completion, producing
carbon dioxide.
In situ leaching is generally referred to as solution mining. Leaching
liquids are pumped underground into an ore body. The desirable material
dissolves or reacts with the liquid. A second recovery well allows the leach-
ing liquid to return to the surface where it can be processed to recover the
leached material.
The advantage of solution mining is avoiding the cost and hazards involved
with underground mining. The disadvantages are environmental concerns over
injecting liquids into the ground water and insoluble contaminants in the ore
body, which may decrease the yield of the leaching process. These insoluble
contaminants can become a significant barrier to mass transfer when they
accumulate. Potential waste treatment applications might involve the removal
of ,metals or organics from sludges or soil using an appropriate liquid
extractant.
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Liquid-solid extraction would not be effective for treating or removing the
dissolved organic contamination in the Firestone Salinas ground water. Thus,
no future consideration will be given to this treatment technology for
implementation at the Firestone Salinas site.
Liquified Gas Extraction
Liquified gas extraction (LGE) is a process that can be effective 1n removing
organics from liquid waste streams. The principles are similar to liquid-
liquid extraction except the solvent is a gas liquified under pressure.
Liquified gases such as carbon dioxide and propane have the ability to extract
many organics. Liquified gas extraction 1s usually carried out in multi-
staged columns providing high extraction efficiencies. The process operates
based on the equilibrium between the solute and liquified gas solvent. It is
controlled by mass-transfer principles similar to distillation, air stripping,
and liquid-liquid extraction. Extraction using a liquified gas generates two
waste streams, an organic fraction (dissolved in the liquified gas) and an
inorganic fraction usually consisting of solids, salts, and water. These two
streams are immiscible. The organic dissolved by the liquified gas can be
recovered by separating the phases, then relieving the pressure on the gas.'
The liquified gas, usually having a substantial vapor pressure difference
compared to the dissolved organics, flashes off, leaving the extracted organic
contaminants behind. The gas can be collected, recompressed, and reused
(Hazardous Material Control, 1988).
This process may have energy advantages over nonpressurized solvent extraction
processes. The energy required to recompress the gas may be less than the
energy necessary to distill off solvent, as might be required by conventional
liquid-liquid extraction processes to recover the extracted organic. However,
this economic advantage may be offset due to the added capital cost of pres-
surized vessels and a compressor.
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Liquified gas extraction could probably be effective in treating the Firestone
Salinas ground water. However, this method would be capital intensive to
implement as a treatment method for removing the organic contamination.
Development and testing would be required to verify the suitability of a
liquified gas extraction solvent and determine proper operating conditions.
Also, gas, liquid extraction (air stripping) has been demonstrated as an
effective and economical treatment method. The developmental expense and
greater capital costs in Liquified Gas Extraction are not justified. Thus, no
further consideration will be given to this treatment method for
implementation at the Firestone Salinas site.
2.4.1.14 Mechanical Separation/Treatment
Mechanical separation is the separation of materials using mechanical-type
equipment. The following are the most common mechanical units used in waste
treatment:
• Centrifuges
• Belt filter presses
• Air classifiers
• Vibrating screens
• Shredders/grinders
• HydrocTones.
Each of these is discussed in the following subsections.
Centrifuges
•The settling out of solids in a tank.or basin due to gravity .is a well knc^n
occurrence. Often settling occurs in chemical processing, and agitation is
required to keep solids in suspension or a mixture homogeneous. The opposite
situation can also be a problem when suspended solids are so fine or. emulsi-
fied that normal gravitational force has no effect on settling them out.
Mechanical centrifuges can increase the apparent force on solids in suspension
up to 300,000 times normal gravitational force (g) depending on the type of
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centrifuge. Centrifuges may operate in batch or continuous mode depending on
the design. The centrifuges that produce the highest g forces (greater than
about 15,000g) are generally batch type and only suited for pilot or labora-
tory operations.
The most widely used centrifuge in waste treatment is. the continuous decanter
centrifuge operating in the range of 2,000 to 5,000g (Moir, 1988). The unit
has a rotating outer bowl with an inner backdrive scroll (similar to a screw
feeder). The slurry is fed up the hollow shaft of the scroll, which rotates
at a faster speed than the bowl. The feed moves through the ports on the
shaft into .the bowl, where the solids form a layer. The liquid depth in the
bowl is controlled by adjustment of ports at the liquid discharge (centrate)
end of the unit. Solids are conveyed away from the liquid end of the cen-
trifuge by the scroll (hence the name backdrive). They are drawn into the
conical end of the bowl and discharged at the opposite end from the liquid.
Polymers are frequently added to enhance separation and produce a drier caKe
(Moir, 1988). Continuous centrifuges are only suitable for treating wastes
containing contaminants greater than one micron in size.
A centrifuge would not be effective for the treatment or removal of the low-
level organic contamination in the Firestone Salinas ground water. Thus, no
future consideration will be given to this treatment method for imp lamentation
at the Firestone Salinas site.
Belt Filter Press
The belt filter press is a mechanical unit which.uses two continuous porous
belts to dewater fibrous organic solids in the 1- to 2-percent solids ringe.
The two belts run. in a continuous loop over a series of rollers. The waste
liquid is introduced onto one belt, which allows free water to drain by
gravity. The waste then travels on the top belt to a point where the'top belt
meets the bottom belt at a point called the wedge zone. The two belts move
together in a wedge-shape configuration, applying greater and greater presses
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to the waste solid (removing more and more water) trapped between the belts.
The two belts then move to the pressure zone over and around a series of
hydraulic rollers where the pressure on the waste between the two belts is
highest (up to 100 psi). After the pressure zone, the two belts separate and
the dry solids drop by gravity into a bin or onto a conveyor belt for loading
or disposal.
Applications of a belt filter press to waste treatment include dewatering of
municipal waste sludge and reclaiming of waste cardboard fiber. Polymers are
often added to coagulate the waste, improve removal efficiency, and produce a
drier cake. This treatment method is effective for removing solids greater
than 500 microns (Deutsch, 1987).
A belt filter press would be ineffective in treatment or removal of the low-
level synthetic organics in the Firestone Salinas ground water. Thus, nc
further consideration will be given to this treatment method for
implementation at the Firestone Salinas site.
Air Classifiers
Air classifiers are devices that separate solid materials based on size. -A.
number of forces act on particles carried by an air stream, such as gravity,
drag, and centrifugal force (if the air stream and particles are rotating).
The simplest form of an air classifier is a cyclone separator that simply
removes particulates from gas streams. The particulate-laden gas stream
enters the cyclone chamber. The chamber is a cylindrical vessel with a cone
bottom. The gas stream is directed tangentally along the cylindrical surface
causing the gas to spin around the cylinder. The particles are moved outward
as a result of centrifugal force. Particulates begin to fall as gravity acts
upon them. When they fall near the bottom, they enter the cone portion of the
i
chamber. The decreasing diameter of the cone accelerates the air stream,
increasing the centrifugal force on particulates and increasing the air pres-
sure in the bottom of the cone. The particulates fall out the bottom of the
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cyclone (carried by a small amount of gas). The cleaned gas exits the top of
the cyclone through a large center exhaust nozzle (due to lower air pressure
at the top of the cyclone). This process is limited to removal of medium to
large particulates. Small particulates are entrained in the gas phase and are
carried out the top of the cyclone.
Air-classifiers make use of drag on a particle in a gas stream as a function
of surface area, volume, density, and gravity to separate (classify) particu-
lates and solids by size. There are numerous commercial air classifying units
available varying in design and configuration (Klumpar et al., 1986). Air
classifiers are useful for grading solid feeds or products by size, which may
be critical to the efficiency of a chemical process or the sale of manufac-
tured materials. The details of the many available commercial air classifica-
tion units will not be discussed further for the purpose of brevity. The
primary application- of this technology to waste treatment is dust or
particulate removal from process gas streams or stack emissions.
Air classification would not be effective for the treatment or removal of the
dissolved organic contamination in the Firestone Salinas ground water. Thus,
no further consideration will be given to this method for treatment of ground
water at Firestone Salinas.
Vibrating Screens'
This method is used to classify dry solids by size or separate water frcm wet
solids using gravity. A descending order series of large surface area screen
trays, each with a different size opening, are fed a dry solid stream or a wei
slurry. The stream cascades down through the series of screens, being
rejected off a side opening in the screen tray if the particle size is tec
large to pass further. Sorted reject particles are collected by screen
size. Each size collected actually is representative of a range of sizes
based on the individual screen characteristics, ranges, and openings. The
screens are energetically vibrated to keep the particles in motion and prevent
plugging.
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Vibrating screens are only effective for participate removal, classification,
or recovery. A vibrating screen would not be effective for treatment or
removal of dissolved organic contaminants as found in the Firestone Salinas
ground water. Thus, no further consideration will be given to this treatment
method for implementation at the Firestone Salinas site.
Shredders/Gri nders
Shredders, grinders, mazorators, choppers, and a host of other units are used
to precondition waste streams to enhance treatment or simplify disposal.
Large solids are a problem for many processes. Plugging of pipelines, agglom-
eration, and overloading or jamming equipment are all problems associated by
oversized or poorly conditioned feed. Sanitary treatment plants frequently
grind all influent feed to prevent line plugging and enhance biological degra-
dation of solids by maximizing surface area. Wood, brush, leaves, and trash
are often chipped or shredded at sanitary landfills to enhance compaction and
biological degradation of waste- materials. Trash or tires are often shredded
prior to burning in incinerators so a uniform feed is provided and process
control problems are minimized. Coal is pulverized to a uniform fine powder
for feed to power plant boilers. Automobiles, appliances, and other objects
are often shredded at reclaim sites to aid the magnetic separation of iron
from other materials.
Shredders or grinders would not provide any benefit toward the conditioning cf
contaminated ground water at Firestone Salinas for treatment or removal cf
dissolved organic contamination. Thus, no further consideration will be a-1 ve-
to this pretreatment method for implementation at the Firestone Salinas site.
Hydroclones •
Hydroclones are liquid-phase versions of cyclone separators. The vessel
design and configuration is very similar and the 'functional mechanics and
process are the same. A liquid feed containing suspended solids enters the
hydroclone. As in a cyclone, the feed is directed tangentially to the outsice
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of the hydroclone cylinder wall. The spinning of the liquid around the hydro-
clone causes solids to move outward as a result of centrifugal force. The
solids drop downward as a result of gravity. Solids concentrate in the cone
bottom, and are discharged out the bottom as a slurry. Clear liquid exits
overhead. The disadvantage of hydroclone treatment is due to entrainment.
Only medium to large particles are rerroved. Also, the collected solids are
still very wet and require further drying before disposal. The primary advan-
tage is cost. It is a.very cheap separation method, requiring only energy
from pumping the fluid through the unit. Variations on hydroclones allow for
size classification of the solids, similar to gas-phase air classifiers.
Hydroclones are suitable for particulate phase removal only. The technology
would not be effective in treatment or removal of the dissolved organic
contamination found in the Firestone Salinas ground water. Thus, no further
consideration will be given to this treatment method for implementation at the
Firestone Salinas site.
2.4.1.15 Magnetic Separation
This treatment method is suitable for separation of paramagnetic materials.
The two magnetic processes having potential applications in waste treatment
are magnetic conditioning and high gradient magnetic separation. Each of
these is discussed in the following subsections.
Magnetic Conditioning . :
This method is primarily used for gross removal of tramp iron from a wice
variety of processes. It has application to mining, metal reclaiming,
chemical processing, and other process where free iron needs to be removed.
Magnetic conditioning is used to protect conveyor belts or sorting areas where
materials pass by. Powerful magnets are suspended to attract any free iron
contaminants or objects such as tools, nails, steel objects, etc. This is
usually done to reclaim the objects or prevent damage further down the
processing line to other units (such as rock crushers).
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Large electromagnetic cranes are used in salvage yards to scavage free iron
from other shredded materials such as plastic or rubber.
Magnetic conditioning would be totally ineffective in removing or treating the
dissolved organic contaminants in the Firestone Salinas ground water. Thus,
no further consideration will be given to this treatment method for implemen-
tation at the Firestone Salinas site.
High-Gradient Magnetic Separation
This treatment method uses very high intensity magnetic fields to affect
separations based on ferromagnetic, paramagnetic, or diamagnetic properties of
the component elements. All but 16 elements exhibit one of these three prop-
erties. The high-grade magnetic separation process (HGMS) requires a high
energy electromagnetic source and a ferromagnetic filament, which may be
felted or woven steel-wool expanded metal, or some similar type of iron
material providing a high void space. Magnetic fields up to 20,000 Gauss are
necessary for treatment to be effective. The waste stream is passed through
the ferromagnetic filament filter. Under applied magnetic fields, impurities
are collected in the filter due to magnetic attraction. When the filter
becomes loaded, the magnetic field is turned off and the filter fabric
decontaminated. HGMS is effective in removing particles as small as one
micron.
Various configurations are possible to allow for cyclic or continuous
operation. Superconductivity magnets show promise by providing even higre-
magnetic fields. There are many potential applications for this technology,
but most are in the developmental stage. Iron ore concentration using HGMS
technology has been commercially demonstrated. Other possible applications
include water treatment and other types of pollution control. The method can
be effective in removing nonmagnetic species, providing they can be trasoec in
an iron matrix such as iron oxide (Klumpar et al., 1986).
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High-gradient magnetic separation, being relatively undemonstrated for waste
treatment, may not be appropriate for removal or treatment of the contamina-
tion in the ground water at Firestone Salinas. Thus, no further consideration
will be given to this treatment method for implementation at the Firestone
Salinas site.
2.4.1.16 Evaporation/Crystal!ization/Drying
Evaporation, crystallization, and drying operations will each be considered in
this section. These operations involve the controlled application of heat to
drive off volatile materials. For the purposes of this discussion,
evaporation, crystallization, and drying do not involve chemical reaction
(other than phase changes) or thermal degradation of the materials involved.
Thermal degradation processes for waste materials are discussed in Section
2.4.4 under "Thermal Treatment." Evaporation, crystallization, and drying are
similar operations except for the extent to which the heating is carried out.
Evaporation, crystallization, and drying are equilibrium processes operating
based on mass-transfer principles and the different volatilities of chemical
species.
Evaporation is applying heat for the purpose of concentrating liquids that may
be pure, solutions, suspensions, or emulsions. Evaporation may also be used
to remove a particular volatile component in a liquid (Wiegard, 1973). The
applications and variations of evaporator design are quite numerous, and will
net be discussed in detail. Evaporation is used in many chemical processing
operations, for solvent recovery, food processing, and water purification
(from brine). Evaporation may be induced by direct or indirect heating or by
the sun (solar evaporation which is usually carried out in outdoor shallow
ponds with large surface areas).
Crystallization is an evaporation-type process; however, the goal is to
recover dissolved solids instead of a concentrated liquid. By continuing tc
apply heat, evaporating the solvent until the saturation point of the solvent
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is reached, precipitation of dissolved solids will occur. Careful control of
this process yields crystals of the dissolved product, which can be recovered.
These crystals may be dry or slightly wet, or even slurried, depending on the
design of the crystallization process.
Drying is a process which produces solvent-free crystals from either a satu-
rated solution or a feed stream of moist or slurried crystals. Dryers apply
sufficient heat to drive off all free solvent.
For brevity, the discussion of the many designs for evaporators, crystal -
lizers, and driers will be omitted. Further information is given in the 6th
edition of Chemical Engineers Handbook.
Evaporation, crystallization, and drying are suitable processes for treating,
concentrating, or removing a wide variety of contaminants in waste streams.
These include heavy metals, radioactive materials, inorganic salts, and many
types of organics (including halogenated organics). The wastes may be aque-
ous, nonaqueous, liquid, slurries, sludges, tars, or solids (Berkowitz et al.,
1978, pp. 466-467). The economics are usually limited by energy consumption.
Evaporation, crystallization, and drying would not be cost-effective methods
for removal of the low levels of organic contamination in the Firestone
Salinas ground water due to high energy consumption. Thus, no further
consideration will be given to this treatment method for implementation at the
Firestone Salinas site.
2.4.2 Chemical Treatment Methods
2.4.2.1 Neutralization
This treatment method is generally applied to the treatment of acidic or basic
solutions of gases, salts, buffers, or organics. The method uses controlled
addition of an acid or base to a solution to either raise or lower pH to meet
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a particular requirement (e.g., permit limit), or to achieve the formation of
a precipitate such as an oxide or hydroxide (see precipitation). Gases such
as sulfur dioxide, carbon dioxide, or ammonia can be used as sources of acids
or bases (once in solution). Also solids such as lime, sodium hydroxide, or
sodium bisulfite are a convenient form of neutralizing agent. Organic acids
or bases may be used but are not usually economical on an industrial scale.
This treatment method is most appropriate for acid waste or basic waste in the
pH range of 0 to 14 and for removal of certain metal ions (see precipitation).
Treatment of highly concentrated acids or bases (outside the 0 to 14 pH range)
can be acccomplished by neutralization, but requires large amounts of chemical
agents and a means to remove the excess heat generated. Neutralization (pH
adjustment) will also aid in the separation of some concentrated oil-water
mixtures (at or near saturation) and breaking of emulsions (see oil-water
separation). Control of chemical addition is essential to prevent the genera-
tion of undesirable species (such as nitrogen trichloride) and overshooting a
neutralization point. Possible chemical side reactions have to be reviewed
before implementing a neutralization process to avoid producing undesirable
side products. -Approximately 15 to 20 minutes residence time is necessary for
neutralization reactions to reach complete equilibrium. This often makes
precise control of addition rates difficult, especially when adjusting near
neutral pH.
Neutralization- would not be effective in the treatment or removal of low
concentrations of dissolved synthetic chlorinated organics as found in the
Firestone Salinas ground water. However, neutralization is used at the
Firestone Salinas site to adjust the pH of the treatment plant effluent to
comply with the NPDES discharge requirements.
2.4.2.2 Precipitation
The two types of precipitation discussed in this section are liquid-solid
precipitation, and electrostatic precipitation. Each of these is discussed in
the following subsections. .
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Liquid-Solid Precipitation
This technology removes a contaminant by creating a second phase that can then
be removed or recovered. Several methods can be used to induce precipitation
in a solution. Addition of a chemical that will react with a species in solu-
tion to form an insoluble product is an effective way to force precipitation
to occur. Materials such as hydrogen sulfide or sodium sulfide, when added to
solutions containing heavy metals, will cause precipitates in the form of
insoluble metal sulfides to drop out of the solution. The solubility of most
metal sulfides (in water) is extremely low. Precipitating heavy metals and
removing the precipitate by media filtration methods reduce the environmental
toxicity of the remaining solution. Chemical addition may also be used to
cause a shift in the equilibrium, resulting in precipitation or coalescence.
This often occurs as a result of simple pH adjustment.
Temperature change is also used to achieve precipitation. Cooling a solution
lowers the solubility of a dissolved species, ultimately to the point of
saturation and precipitation. Heating a solvent containing dissolved compo-
nents will result in evaporation of the solvent. (Refer to Section 2.4.1.16
Evaporation/Crystal!ization/Drying.) Once the saturation point is reached in
the remaining solvent, precipitation of the solute will occur. This tech-
nology is best suited for high concentrations in solution and more particu-
larly for inorganic species and metal ions.
Precipitation would not be effective for treatment or removal of dissolved
organics found in the Firestone Salinas ground water. Thus, no further
consideration will be given to this treatment method for implementation at the
Firestone Salinas site.
Electrostatic Precipitation
This treatment method is an electrolytic treatment method for removal of
particulates from gas streams. Gas from a combustion or chemical process is
passed between two plates energized with ac electric current. Particulates
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through the field become charged and migrate to one plate or the other
depending on the charge of the particle (electrical attraction). The plates
eventually become loaded; and periodically the current is shut off, and the
plates are cleaned by mechanical means, such as compressed air blasting. This
treatment method is used commercially for cleanup of stack gases from power
plants.
This method would be ineffective for treatment of the Firestone Salinas ground
water. Thus, no further consideration will be given to this method for
implementation at the Firestone Salinas site.
.*
2.4.2.3 Ion Exchange
Ion exchange treatment technology uses natural or synthetic inorganic crystals
(zeolites), stationary-phase synthetic ion exchange resins, or dispersed
chelating agents to remove or bind ions contained in a solution. Ion exchange
is generally limited to removal of metal ions or charged organic species such
as cyanide. Stationary-phase synthetic ion exchange resins consist of a
polymeric backbone with various active salt-forming organic groups attached to
the end of the polymer chains. Potential active groups may be sulfonic,
carboxylic, phenolic, and various amine groups. The ion exchange process Is a
reversible exchange between the insoluble solid salt (the ion exchanger) and
an ion-containing solution. The driving force for the exchange of ions
between the exchange agent and solution is a function of the equilibrium
determined by the relative insolubilities of the salts that can form 5y iors
present and the exchange agent. Adjusting concentrations or shifting the pH
changes the relative solubilities, thus making the process reversible.
Reversibility allows for recovering the species removed from the solution and
essentially endless regeneration/reuse of the resin (Berkowitz et a!., 1973,
pp. 633-636).
Chelating agerts are structurally similar to synthetic ion exchange resins
except that the polymer backbone, which makes resins fixed phase, is nc*
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present. The active agent is free to move throughout a solution. Chelants
are used most frequently to bind metal ions in solution, usually to prevent
them from interfering with polymerization or other. chemical reactions.
Stationary-phase resins are usually best suited for waste treatment applica-
tions because the contaminants are actually removed, not just bound in an
unavailable form.
In actual operation, the ion exchange resin in the form of polymeric beads is
loaded into a column. The solution to be treated is usually passed downward
(concurrent) through the resin column. Ions from the resin are exchanged for
ions in solution. Either cations and anions can be exchanged, depending on
the resin type. Various resin forms are available such as sodium-ion exchange
resins or hydrogen-ion exchange resins. These resins (sodium and hydrogen)
cm be regenerated with strong salt solutions or acid solutions respectively,
when exhausted (a reversal of the equilibrium). There are also various column
configurations that allow for cocurrent, countercurrent, or continuous
operation.
Ion exchange technology is best suited for removal of ionic species. Ion
exchange would be ineffective for removal or treatment of the dissolved
organics found in the Firestone Salinas ground water. Thus, no further
consideration will be given to this treatment method for implementation at the
Firestone Salinas site.
2.4.2.4 Oxidation
The six oxidation technologies that have potential in waste treatment
applications are as follows:
• Chemical oxidation
• Wet air oxidation
• Supercritical fluid oxidation
• Electrolytic oxidation
• Thermal oxidation
• Bioloaical oxidation.
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The first three of these technologies are each discussed in the following
subsections. The, last three technologies, electrolytic oxidation, thermal
oxidation, and biological oxidation, are discussed in Section 2.4.2.5 -
Reduction, Section 2.4.4 - Thermal Treatment, and Section 2.4.3 - Biological
Treatment.
Chemical Oxidation
Chemical oxidation treatment is the controlled addition of chemical oxidizing
agents to a waste stream to cause chemical transformation (via oxidation) of
the waste to simpler or less toxic components. Sources of oxidants include
air, oxygen, ozone, hydrogen peroxide, chlorine, chlorates, chlorites, hypo-
chlorites, perchlorates, permanganates, or strong oxidizing acids (such as
nitric acid). The ideal products of chemical oxidation reactions are simple
nonhazardous components such as carbon dioxide or water. Often species such
as HC1, N02» or $03 are generated that may require additional treatment before
ultimate disposal. These reactions are termed "redox reactions" since
oxidation (of the water) and reduction (of the oxidizing agent) occur at the
same time.
Oxidation of some species may also produce insoluble precipitates. This
occurs when solutions of metal ions are oxidized to produce metallic oxides cr
hydroxides. Precipitates may then be removed by media filtration or centri-
fugation, leaving a less environmentally toxic solution. The effectiveness of
the oxidation process depends on the chemistry and reactions involved. The
usual limitations are removal of evolved heat (oxidations are generally exo-
thermic), control of side reactions that may generate unwanted intermediates
(and consume the active oxidant), reactivity of the waste species, and toxi-
city of the oxidation products. Chemical oxidation is a method primarily for
treatment of organic-containing wastes of moderate to high reactivity.
Moderate to high reactivity organics include alcohols,,ketones, organic acids,
alkyl and nitro-substituted aromatics, unsaturated alky! grouos, carbohy-
drates, phenols, aldehydes, amines, and various sulfur compounds. The
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selection of an oxidant is made based on a number of factors including cost,
availability, side reactions, oxidant strength, and toxicity.
Low reactivity compounds include halogenated hydrocarbons, saturated alpha-
tics, and benzene. These types of compounds are particularly resistant to
chemical oxidation. Chemical oxidation of these low reactivity organics may
be difficult, expensive, slow, or impossible to accomplish only by chemical
means. Chemical oxidation in conjunction with UV light (photolysis) is effec-
tive for some of these species (see photolysis - Section 2.4.2.6). Further,
some organics such as polyethylene or polypropylene have very low reactivity
toward chemical oxidants and are classified as refractory organics. These
materials can be oxidized only by using other methods such as thermal
oxidation.
Chemical oxidation would be effective in treating the dissolved chlorinated
organics in the Firestone Salinas ground water. However, the probable slow
reactivity of these organics with chemical oxidants would require longer
retention times and large holding volumes to achieve complete destruction.
Ultraviolet (UV) radiation treatment with chemical oxidants has been
demonstrated as effective; however, the capital cost, potential adverse side
reactions (which may produce HC1 or short-chain chlorinated organics), and
byproducts of this type of treatment make it potentially unsuitable. Thus, no
further consideration will be given to this treatment technology for implemen-
tation at the Firestone Salinas site.
Wet-Air Oxidation
Wet-air oxidation is a process technology that uses oxygen (usually using air
as the source) and water under h-igh temperature and pressure (but under the
critical point of water) to oxidize organics and certain metal ions. The
technology is 'primarily applicable for treatment and detoxification of
municipal sludges and moderate concentrations of most organics.
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The process begins by preheating the feed and pumping it into the wet-air
oxidation tower (reactor). The pressure and temperature required for destruc-
tion is specific for each waste type depending on how resistant the waste is
to oxidation and the BOD/COO requirement. Essentially a wet-air oxidation
reactor, is a BOD/COD reducer. The primary limitations on capacity are the
residence time, blower capacity (oxygen source), heat transfer, and organic
concentration in the waste stream.
The organic concentration and composition of feed wastes is the primary
economic factor influencing the applicability of this method. Although wet-
air oxidation can be used to treat most organic waste streams, dilute or
highly concentrated wastes are more costly to treat. The process requires
heat, usually derived from the reacting feed, to maintain temperature and
pressure. Low concentrations of organics in the feed do not provide enougn
heat value to self sustain the process. Dilute waste streams require
additional fuel, usually added to the feed in the form of diesel fuel or
kerosene. High concentrations of organics in the feed produce excess heat,
requiring high water consumption to remove the excess heat from the reactor
(in the form of steam) and making control more difficult. Economic operation
and control depend on a consistent feed concentration.
In actual operation of a wet-air oxidation reactor, water and waste (and fuel
if necessary) are premixed and balanced, then fed to the reactor to maintain
near-constant temperature and pressure. Water must be present to provide
steam for pressure and a media for the (wet phase) oxidation reaction to take
place. A consistent feed is essential to prevent drastic pressure and
temperature shifts and possible incomplete treatment. Catalysts such as
nitric acid are sometimes used to speed up the reaction or allow operation at
lower temperatures. Wet-air oxidation is particularly effective to treat
refractory organics such as polyethylene, chlorinated organics, pesticides,
and other otherwise untreatable wastes. Treatment of halogenated soecies and
other types of organics may produce aggressive by-products that require exotic
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metallurgy. Reactors are usually constructed of high-grade stainless, nickel
alloys, or titanium.
Wet-air oxidation has only been pilot demonstrated (10 gpm) for hazardous
waste treatment (Zimpro, Series 300). This technology requires sophisticated
process control and peripheral equipment such as high-pressure pumps and
compressors, and exotic alloy heat exchangers. Some of the other problems
associated with operation of a wet-air oxidation reactor include disposal of
salts in the treated effluent and control of fugitive emissions. The
technology is very well suited for the treatment of municipal sludge.
Numerous full-scale wet-air oxidation installations are in operation at POTWs
throughout the country.
Wet-air, oxidation technology is not considered economical for dilute wastes
due to potential high energy cost and consumption. Wet-air oxidation would
not be economical for treating the low concentrations of chlorinated organics
in the Firestone Salinas ground water. Also, the capital cost to meet the
capacity (ground water volume) requirement would make this technology prohibi-
tively expensive to implement. Thus, no further consideration will be given
to this treatment method for implementation at the Firestone Salinas site.
Supercritical Fluid Oxidation
This technology is similar to wet-air oxidation except that the operating
conditions are above the critical temperature of water. Under these
conditions of high temperature and pressure, salts precipitate and can be
recovered. Organics are completely oxidized or can be extracted and recovered
depending on the supercritical fluid medium (i.e. water, carbon dioxide,"
etc.). This process is being discussed as an oxidation technology sines
recovery of toxic organics in waste treatment is usually less important than
destruction, especially for dilute solutions. In waste treatment, the primary
application of the technology is to oxidize organics to the simplest
constituents and recover metal salts (usually in the form of oxides). Often
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this technology is referenced in the literature as supercritical fluid
extraction. The technology may fit in either category depending on the
operating conditions. In this section, the technology is considered as a
high-pressure supercritical variation on wet-air oxidation treatment.
Control and metallurgy problems are magnified in supercritical fluid oxidation
processing because of higher operating temperatures and pressures and the more
aggressive operating environment. Pumps, heat exchangers, and other peri-
pheral equipment must be constructed of exotic materials. Equipment becomes
expensive to meet the demand of rigorous operating conditions. However, one
advantage of supercritical operation is that the reactor volume and required
residence time in the reactor to achieve complete oxidation are much-smaller
(than for wet-air oxidation). This results in downsizing of much of the
equipment. Despite this advantage, however, the technology does not have any
commercial demonstrations reported to date for waste or hazardous waste treat-
ment. Extensive laboratory work and testing have been performed, resulting in
the issue of several patents for the use of supercritical fluid oxidation in
hazardous waste treatment. Other applications of supercritical fluid tech-
nology have been commercialized, including a supercritical fluid extraction
process to remove caffeine from coffee.
Supercritical fluid oxidation technology has not been commercially demon-
strated or piloted. Supercritical fluid oxidation has not been proven as a
suitable method for the treatment of ground water. Thus, no further
consideration will be given to this treatment method for implementation at the
Firestone Salinas site.
2.4.2.5 Reduction
Reduction technology for chemical separation or t/ansformation is. well known
in the production of pure reactive metals, in refinery processes, and waste
treatment. The following three types of reduction processes are discussed in
this section:
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• Electrolytic oxidation/reduction
• Chemical reduction
• Direct hydrogenation.
Each of these methods is discussed individually in the following subsections.
Electrolytic Oxidation/Reduction
Electrolytic reduction involves application of dc electric current across an
electrolytic cell. Control of voltage and amperage can affect many separa-
tions that are impossible using other methods. Electrolysis of molten salts
is a technique used to produce materials, such as sodium metal, aluminum,
magnesium, fluorine, and other very reactive materials. Electrolysis of salt
solutions is the major process for producing chemicals sucn as sodium hydrox-
ide and chlorine. In an electrolytic cell, oxidation and reduction take place
simultaneously at the anode and cathode respectively. Reduction reactions
often produce pure metals or hydrogen (from reduction of hydrogen ions present
in solution or reduction of water). Reactive metals when electrolyzed from
solutions further react with the solution to form other species. This occurs
when sodium chloride solutions are electrolyzed. The final.' products are
chlorine, hydrogen, and sodium hydroxide. The intermediate product of sodium
metal is electrolyzed from the solution but immediately reacts with the water
present to form sodium hydroxide and hydrogen. Electrolytic cells have been
developed and improved for various waste treatment applications. The primary
use of this technology is for treatment of waste streams containing dissolved
metals or ionized organics.
Over 200 commercial electrolytic treatment systems are in use for heavy metal
treatment. This technology has been extended to treatment of ground water
containing heavy metal contamination. Variations on the electrochemical cell
have proven effective for the treatment of fluorides and non-ionized organics.
The electrolytic process is effective for treatment of such a wide variety of
waste because it provides four treatment operations in one unit. Oxidation
and reduction occur at the anode and cathode. Electrolysis of water produces
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hydroxide, which helps adjust the pH and precipitate metals. A sacrificial
iron anode is oxidized to. produce iron hydroxide in solution. This form of
iron (as reported in Section 2.4.1.5, under Physical Adsorption), acts as an
adsorbent. In solution both ionized and non-ionized species (organics) may be
trapped in the iron hydroxide matrix and coprecipitated. Further evaluation
of this treatment method is ongoing for treatment of organics. Ground-water
treatment where both inorganic and organic contamination are involved might be
easily and more economically treated with a single^electrochemical unit as
compared to other multiple treatment operations addressing each waste type
(Berkowitz et a!., 1978).
Electrochemical treatment is an emerging and relatively untested technology
for removal of chlorinated organic hydrocarbons. The technology may not be
totally effective for treatment of the Firestone Salinas ground water. Thus,
no further consideration will be given to this treatment method for
implementation at the Firestone Salinas site.
Chemical Reduction
Chemical reduction uses chemically induced reduction reactions to cause a net
reduction in the oxidation state of a chemical species. Waste treatment is
performed by selecting reducing agents that are powerful enough to convert
(reduce) a hazardous species to less hazardous or nontoxic species of a lowe"
oxidation state. A good example of this technology applied to waste treatment
is the reduction of Chrome VI to Chrome III using sodium sulfite, bisulfite,
metabisulfite, or sulfur dioxide as the source of the reducing agent. The
reaction proceeds under acidic conditions by converting the sulfite source to
free sulfurous acid. The sulfurous acid is oxidized by the Chrome VI to
sulfate. Chrome VI is alternatively reduced to Chrome III. The chemistry is
fairly complex, as is the case for most chemical reduction reactions. These
reactions are termed Redox reactions since oxidation and reduction occur at
the same time.
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Chemical reduction of metals dissolved in solution is a common waste treatment
operation. Reduction technology also extends to the treatment of organics but
is limited. Reagents such as borohydride, lithium aluminum hydride, aluminum
hydride, reactive metals such as sodium, potassium, or lithium, hydrazine,
diborane, and a host of other agents can be used to reduce organics. The
reactivity of these reagents limits their usefulness in waste treatment since
many are also very water reactive. Reducing agents are often added to
chemical manufacturing processes to scavenge for impurities.
Chemical reduction technology is primarily effective for treating wastes
containing metals. The limited applications of this treatment technology for
organics makes this method impractical to treat the low-level concentrations
of synthetic organics in the Firestone Salinas ground water. Thus, no further
consideration will be given to this treatment method for implementation at the
Firestone Salinas site.
Direct Hydrogenation
Under pressure and usually with the aid of a catalyst, many organic species
can be directly hydrogenated and subsequently reduced. The technology
involves direct addition of hydrogen to a wide variety of organic functional
groups. The conditions required may be mild, as is the case with aromatic
amines and aromatic nitro compounds (that can be hydrogenated at 3 to 4
atmospheres using a nickel catalyst). Benzene can be hydrogenated to cyclo-
hexane but requires hydrogen at several hundred atmospheres and high temoera-
ture (House, 1972). Direct hydrogenation requires careful process control and
safety measures for handling the hydrogen gas. The technology has wide
application in synthetic organic and petrochemical manufacture but limited
application to waste treatment due to the safety concerns, capital costs, and
rigorous operating conditions.
Direct hydrogenation would be unsuitable as a treatment technology for the low
levels of synthetic organics In the Firestone Salinas ground water. T.nus, no
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further consideration will be given to this treatment method for implementa-
tion at the Firestone Salinas site.
2.4.2.6 Photolysis
Photolysis, as applied to waste treatment, is the inducement of chemical
transformations using light. Light, for the purposes of this section, refers
to radiation within the ultraviolet (UV), visible, or infrared (IR) radiation
spectrum. Other frequency ranges are discussed in Section 2.4.2.7 under
Irradiation. Breaking of bonds using light is well known in organic chem-
istry. Light of the appropriate frequency and intensity cleaves many types of
chemical bonds, according to the principles of quantum mechanics. The mechan-
isms are complex and the applications specific, but the technology has useful-
ness, especially in the treatment of difficult-to-handle compounds such as
pesticides and dioxin. Light sources may be the sun; low, medium, or high
pressure mercury-arc lamps; fluorescent lamps; or lasers. The selection of
the light source depends on the required intensity and frequency of the
radiation necessary to accomplish the desired chemical transformation. Photo-
lysis is often applied in conjunction with other technologies such as UV and
ozone treatment, UV and chlorine treatment, or UV and peroxide treatment. The
major advantage of this technology is that specific bonds can be targeted by
selection of the appropriate frequency and intensity of the light source.
UV light is frequently used as a sterilizing agent. A number of comrne-cial
applications have been developed as well as demonstrated in pilot plants for
treatment of dioxins and PGBs. Rearrangement, side reactions, and the by-
products produced may limit the application of this technology. The treatment
may produce species which are as hazardous or difficult to remove as the
original contaminants. The residence time required to achieve complete
destruction may limit processing capacity or require a prohibitive increase in
the size of the photolysis reactor. Also, depending on the light intensity
required, energy consumption could be extremely high.
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Technical limitations would make photolysis impractical for treatment of the
dissolved organics in the Firestone Salinas ground water. Thus, no further
consideration will be given to this treatment method for implementation at the
Firestone Salinas site.
2.4.2.7 Irradiation
Irradiation using high-energy gamma rays, x-rays, or microwaves is currently
an experimental method for hazardous waste treatment. Microwave irradiation
of metal-containing organics with oxygen in the plasma phase is an experi-
mental method to remove metals by depositing the metals in the form of metal
oxide films. This technique would have limited commercial value in waste
treatment due to cost; however, it might be developed for production of high
technology ultrapure materials.
Gamma irradiation treatment' is an experimental method that has been applied to
the treatment of pesticides. Gamma irradiation of labile food stuffs is a
highly controversial method for sterilizing, preserving, or prolonging shelf
life.
Irradiation treatment using sources such as radio waves would not be effective
in waste treatment applications. Radio-wave frequencies and bandwidths have
the wrong magnitude or are the wrong frequency to break chemical bonds cr
cause chemical transformations.
The drawbacks of irradiation use in waste treatment are limited applicability,
safety, and energy consumption. High-energy gamma ray sources, x-ray sources,
and high-energy microwave generators require extensive shielding and isolation
to protect operating personnel. Gamma ray sources are often expensive and
require careful handling and licensing as a nuclear material. X-ray and
microwave generators become expensive as they become larger for commercial
applications. Also, energy (electrical) consumption becomes a cost factor
with larger commercial x-ray and microwave units.
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Irradiation is currently an experimental method for treatment of very
difficult-to-treat or extremely hazardous wastes. Sterilization by irradia-
tion is a potential commercial application but has drawbacks.
The limited demonstrated waste treatment applications and safety concerns make
this method inappropriate for removal or treatment of the dissolved organics
in the Firestone Salinas ground water. Thus, no further consideration will be
given to this treatment method for implementation at the Firestone Salinas
site.
2.4.2.8 Stabilization
.Stabilization is a treatment process for immobilizing waste materials to
prevent them from entering the environment or food chain. Stabilization does
not destroy the waste but alters it chemically or physically to prevent mobi-
lization (leaching). Other terms that describe this process are fixation,
encapsulation, or cementation (Parmele et al., 1986)
The four stabilization processes are as follows:
• Inorganic microencapsulation/fixation (incorporate the waste into a
silicate-based mix such as cement or kiln dust).
Inorganic vitrification (melt or fuse the waste, discussed in
Section 2.4.4 under thermal treatment).
• Organic microencapsulation (incorporate the waste into a polymer or
asphalt matrix).
• Organic encapsulation (surround a waste volume in a polymer shell).
These will be discussed separately as inorganic and organic stabilization
methods.
Inorganic Stabilization
Inorganic stabilization may involve the following chemical reactions:
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• Neutralization (acid/base)
• Precipitation (insolubilization)
• Hydration
• Addition
• Substitution
• Complexation
• Ion Exchange
• Adsorption.
The process involves the interaction between the waste (soluble) and sili-
cates, alkali, water, salts, and the ions 'present. The result is the micro-
encapsulation of insoluble waste particles and solidification of the liquid
waste fraction. The reactions are termed cementation reactions or pozzolanic
reactions. The difference between cement and pozzolanic materials is that
pozzolanic compounds require lime to form a cement (materials such as fly ash
or volcanic ash), whereas materials like calcium silicate do not. Waste
materials, cement material, water, and stabilizers are balanced and mixed in a
pug mill or other solids blending unit. Once the cementation reaction takes
place, the waste material is encapsulated and should not be leachable.
Stabilization is a useful method for treatment of metal-containing wastes.
Metal-containing waste must be either recycled or stabilized since they are
not destroyed by conventional treatment methods. The cementation reaction
does take some time to go to completion. The reaction also requires water.
Totally "dry solids must be wetted in order to stabilize them. Likewise,
extremely wet or diluted materials become extremely expensive to treat due to
the large amount of cement material required to form the mix. Some materials
such as acids may require neutralization or pretreatment to prevent inter-
ference with the cementation reaction.
Inorganic stabilization would be uneconomical for treatment of the low-level
organic contamination in the Firestone Salinas ground water. Thus, no further
consideration will be given to this treatment method for implementation at the
Firestone Salinas site.
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Organic Stabilization
Organic stabilization uses polymers, asphalt, polyolefins, or plastics to
encapsulate or isolate (microencapsulate) waste materials. Encapsulation is
the sealing of a large waste mass with the stabilization agent (i.e. a vault
around the waste mass). Microencapsulation involves the blending of the
stabilizing agent through the waste, forming an aggregate that hardens, isola-
ting individual waste particles from each other and from the environment.
This process usually requires heating or in situ catalysis of a monomer
(resulting in formation of the polymer). When the encapsulating material
cools, 1t hardens into a stable refractory organic, inert to all but the most
aggressive attack. This method is more expensive than_inorganic treatment and
would not be appropriate for dilute aqueous wastes.
Organic stabilization would not be an appropriate or cost-effective treatment
method for the dissolved.organic contamination in the Firestone Salinas ground
water. Thus, no further consideration will.be given to this treatment method
for implementation at the Firestone Salinas site.
2.4.3 Biological Treatment
The following seven biological waste treatment methods will be discussed:
• Aerobic degradation
• Anaerobic digestion
• Enzymatic conversion
• In situ biological remediation
• Controlled bacterial applications
• Composting
• Aquaculture.
Variations on each technology will be discussed where appropriate within tne
individual sections.
2.4.3.1 Aerobic Degradation
Aerobic degradation is a biological treatment process that user. nat'j-z"
bacteria to convert (oxidize or hydrolyze) waste organics by enzymatic
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action. Aerobic degradation requires oxygen by definition and function. The
following aerobic processes are the most commonly used in waste treatment
today (Other less common methods function by similar biological mechanisms and
will not be discussed individually for the purpose of brevity):
• Activated sludge treatment
• Aerated ponds or lagoons
• Trickling filters
• PACT™ (powdered activated carbon treatment).
These are discussed individually. PACT™ (a registered trademark of Zimpro
Inc.) is discussed separately in Section 2.4.1.5.
Activated Sludge Treatment
Activated sludge treatment is a biological process that relies on the genera-
tion, maintenance, and continuous recycling of biomass (living bacteria"!
culture) to decompose organic matter. The biological decomposition of the
waste is the result of enzymatic conversion of organic matter as part of the
life functions of the bacteria.
Activated sludge treatment is applicable to waste streams containing less than
1 percent solids and moderate concentrations of organics. Very low organic
concentrations do not provide enough "food" to sustain the activated sludge
biomass. Very high concentrations may require additional dissolved oxygen
added as air or pure oxygen under pressure. Activated sludge processes are
sensitive to heavy metal contaminants. Although the biomass can be acclimated
to tolerate metals, it is best to pretreat the. influent with lime to remove
them. The biomass acts as a BOD/COD reducer, able to digest a wide variety of
organic contaminants. However, not all species are degraded, such as certain
refractory organics and species including polychlorinated biphenyls. Some
halogenated organics can' be degraded but at slower rates compared to other
organics. Activated sludge processes are very sensitive to drastic changes in
feed concentration. The biomass must be acclimated slowly; otherwise, the
bacterial culture may die.
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The activated sludge process requires two steps. In the first step, the
incoming waste feed is mixed with recycled biomass (from the clarifier),
aerated, and allowed to react in the aeration basin. In the second step, the
mix flows to a clarifier, where the activated sludge is allowed to settle. A
portion of the sludge is recycled to the aeration tank and a portion is sent
for disposal. The;effluent (overflow) from the clarifier decants and is sent
for further treatment or disposal. Pretreatment of., the feed may be necessary
to remove metals or adjust the pH. Often a large equalization tank is used to
stabilize possible shifts in waste feed composition. Nutrients may also be
added to enhance and optimize bacterial growth and function.
Activated sludge.treatment would not be cost effective to treat the low levels
of contamination in the Firestone Salinas ground water. There are not enough
organics in the ground water to sustain an activated sludge biomass. Also,
the retention times required would make implementation of this technology
prohibitively expensive due to massive holding basins and clarifiers. Thus,
no further consideration will be given to this technology for implementation
at the Firestone Salinas site.
Aeration Ponds or Lagoons
A common and effective aerobic treatment method is an aeration pond cr
lagoon. Aerobic bacterial action is most effectively used for treatment cf
dissolved organic species. A relatively shallow pond when mechanically
aerated becomes an efficient aerobic waste treatment reactor. Although ar
aerated pond is not as efficient as an activated sludge process, net treatment
cost is cheaper due to lower initial materials and construction cost (assuming
land is relatively inexpensive and available.) Aeration ponds are best suited
for treating waste streams with loadings, of less than 1 percent solids.
Higher solids loading may fill up the. pond quickly, requiring expensive
dredging to restore operation. Aeration ponds require longer retention times
than activated sludge treatment. Depending on the pond depth, both aerobic
and anaerobic activity may take place. Aeration ponds are sensitive to
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changes in ambient temperature. Biological activity drops off below 30°C and
may cease near freezing.
Aeration ponds may not be totally effective for treatment of the dissolved
chlorinated organics in the Firestone Salinas ground water. Also, the slow
rate at which aerobic bacteria breakdown chlorinated organic hydrocarbons
would require a very large pond to provide adequate residence time. The cost
of construction and procurement of land make this method unsuitable. Thus, no
further consideration, will be given to this treatment method for
implementation at the Firestone Salinas site.
Trickling Filters
A trickling filter is a simple application of aerobic biological treatment. A
packed bed of stones or synthetic media provides a surface for a bacterial
slime to grow and develop. As the waste flows through the filter bed, contam-
inants are removed and digested by the bacterial cell mass (slime). The
advantage of a trickling filter is that it provides a large surface area for
the bacterial slime to grow, a large area for intimate contact of the waste
stream with the bacterial mass, and a means to aerate the waste stream,
providing good conditions for biological activity. Anaerobic bacteria may
also grow underneath the aerobic bacterial slime, if the slime layer grows
thick enough. Thus, both anaerobic and aerobic reactions may occur within the
same unit. Trickling filters decompose a wide range of organics similar to an
activated sludge process. However, since the residence time within the trick-
ling filter is less than for an activated sludge treatment unit, the effici-
ency is not as high. Reflux of a portion of the filter effluent is one
technique that helps improve efficiency. Trickling filters have the advantage
over activated sludge treatment of being more tolerant of shock loading.
Also, trickling filters tend to produce a more uniform effluent quality when
influent quality varies. Shock loading should be avoided as much as possible
as it may cause overgrowth of the bacterial and sloughing of the bacterial
slime mass from the filter packing. Shock loading as a rule should be avoideo
with all biological treatment processes (Berkowitz et al., 1973, pp. 253-259).
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A trickling biological filter would be inefficient for treatment of the low
concentration of organics in the Firestone Salinas ground water. There would
not be an adequate amount of organics present to sustain sufficient bacterial
mass. Thus, no further consideration will be given to this treatment method
for implementation at.the Firestone Salinas site.
2.4.3.2 Anaerobic Digestion
Anaerobic digestion is a bacterial treatment process that takes place in the
absence of air (oxygen). Two types of bacteria work in conjunction (symbi-
osis) with each other. Acid-forming bacteria hydrolyze complex organics to
organic acids, alcohols, carbon dioxide, and hydrogen. Methane-producing
bacteria utilize the end products of the acid-forming bacteria to produce
methane and cell mass. The process produces a low amount of waste sludge
because a high portion of the organics are converted to methane and CC^
instead of cell mass. The process can tolerate a higher percentage of solids,
up to 15 percent. Conventional digesters are closed tanks with no agitation
and provide a retention time of 30 to 60 days. High rate digesters have
provisions for mixing, reducing the retention time to an average of 14 to
16 days. Sludge volume can be reduced 40 to 60 percent by anaerobic digestion
compared to aerobic digestion (Berkowitz et a!., 1978, p. 218).
Control of an anaerobic treatment process is essential. Anaerobic bacteria
reproduce slowly, thus controlling upsets is critical to performance. Upsets
occur when acid-forming bacteria increase in number relative to their methane-
forming counterparts. This produces an excess of acid, reducing the number of
methane-forming bacteria. Methane-forming bacteria are sensitive to acid
build up. Should an acid imbalance occur, pH adjustment or shut down of the
feed may be necessary to prevent totally killing all the methane-producing
bacteria. This would result in digester failure that is very odorous and
messy to clean out.. Anaerobic bacteria are also sensitive to certain metaU
and various organics depending on the concentration. The technology is most
appropriate for waste streams containing volatile solids and a good supply of
digestible organics (Berkowitz et al., 1978).
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Anaerobic digestion would not be suitable for treating the low levels of
synthetic organics in the Firestone Salinas ground water. Inadequate organic
feed to sustain bacterial and long residence time requirements would eliminate
this method on the basis of operating and capital cost. Thus, no further
consideration will be given to this treatment method for implementation at the
Firestone Salinas site.
2.4.3.3 Enzymatic Conversion
Enzymes are natural biochemical catalysts manufactured by living cells that
allow specific life function chemical reactions to occur under mild temperate
conditions (around 30°C). Enzymes typically are polypeptide chains (amino
acids) of molecular weights in the range of 1 x 10 mass units (Mark, 1985).
There are four categories of enzyme activity. Absolute enzymes catalyze only
one specific reaction. Stereospecific enzymes catalyze reactions of one type
of optical isomer but not the other, but may also cause reactions in a similar
class of the same optical configuration. Hydrolyzing enzymes react with a
specific organic group, such as alcohols, esters, or organic acids. Point-
specific enzymes react at specific sites on a particular molecule, such as
cleaving of a specific bond (Mark, 1985).
The structure and order of amino acids making up the enzyme determine its
reactivity and function. The primary enzyme structure is determined by the
linear configuration or order of the amino acid units. Further structure
results as the chain twists and folds on itself, giving it a highly intricate,
three-dimensional structure and spacial arrangement. The intricate enzyme
structure results in the creation of very specific sites on the enzyme mole-
cule. These catalytic sites allow very specific reactions to occur (Morrison
et al., 1973). Enzymes are temperature sensitive, being deactivated at 50= to
70°C. This is a result of higher temperatures distorting the enzyme struc-
ture. Weak hydrogen bonds may be stretched or broken at higher temperatures,
disorienting or destroying the specific catalytic site on the enzyme me-'ecu"e.
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Enzymes are produced as part of the continuing life function of cells,
governed by instructions in the cell's DMA. Specific enzymes may be recovered
from various sources including plants, animal organs, and cell cultures (Mark,
1985).
*
Enzymes simply added to solution may lose their catalytic activity rapidly due
to agitation, pH, metals in the solution, temperature, and other organics
present. Various methods have been developed to immobilize enzymes on fixed
substrates. Immobilization allows use of the enzyme similar to catalysts
packed in a fixed bed reactor. Fixed or soluble enzymes may be introduced
into a stirred tank reactor, accelerating a desired conversion. Enzymes might
then be recovered for reuse or removed if catalytic activity is lost. Commer-
cial applications of enzyme conversion include the production of high fructose
corn syrup, production of antibiotics, and fermentation.
Waste treatment is generally performed using the bacteria, which produces the
enzyme rather than recovering a specific enzyme and using that to break down a
particular toxic component. There are enzymes that perform conversions, such
as converting urea to carbon dioxide. The literature surveyed did not report
specific enzymes for treatment of chlorinated organic hydrocarbons. However,
various types of aerobic bacteria are known to break down chlorinated organics
slowly. Few examples of the isolation and commercial availability of specific
enzymes that might be used in ground water treatment are reported in the
literature.
Enzymatic conversion is inappropriate for treatment of the Firestone Salinas
ground water due to the unavailability of suitable enzymes. Thus, no further
consideration will be given to this treatment method for implementation at the
Firestone Salinas site.
2.4.3.4 In Situ Biological Remediation
This technology is a method used to enhance the natural breakdown of contami-
nants that have been released into ground water or soil. The technology
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involves injecting nutrients and available oxygen-enhancing chemicals (such as
hydrogen peroxide) into an underground contaminated aquifer. Nutrients and
increased oxygen levels stimulate natural bacterial growth. The increased
numbers of bacteria break down the contaminants present at an accelerated rate
as a result of the artificially enhanced optimized growth conditions. In
addition, the bacterial action accelerates the release of contaminants
adsorbed on soil particles. When the remediation is completed, bacterial
levels return to normal, leaving no hazardous residuals. In situ biological
remediation, when technically appropriate to implement, may cut the
remediation time for a site by 90 percent over pump-and-treat methods alone.
In situ biological remediation works best when dissolved organic concentra-
tions are high. Usually pump-and-treat methods are combined with in situ
biological remediation to control the flow of nutrients. Nutrient solutions
can be directed within a contamination plume by injecting upgradient of a
pump-and-treat extraction well. In situ biological treatment can be effective
for vadose zone contamination, provided a suitable delivery method (such as
percolation) can be devised to deliver nutrient solutions.
Cultured natural bacteria (selected to consume specific contaminants) may also
be injected in addition to the nutrient solutions. Release of certain geneti-
cally engineered bacteria into the environment is still controversial but may
have some application in the future. Genetic engineering may allow the devel-
opment of bacteria that will treat difficult or slow degrading contaminants
such as DDT or PCBs. Chlorinated hydrocarbons pose a particular problem as
they are slow to degrade biologically.
In situ biological remediation would be difficult to implement at the
Firestone Salinas site due to the size and depth of the plume, high recharge
rate of the aquifer, and low concentrations of organic compoundss in the
ground water. The benefits are limited due to slow biological breakdown of
chlorinated organics. The additional cost is not considered to be justified.
Thus, no further consideration will be given to this treatment rneinod for
implementation at the Firestone Salinas site.
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2.4.3.5 Controlled Bacterial Applications
Engineered bacterial applications fall into the following two categories:
• Naturally selected
• Genetically engineered.
Each of these .applications is discussed in the following subsections.
Naturally Selected Bacteria
Since early civilization, bacteria and yeast have been used to produce w.ine
and cheese through fermentation. As more was learned about these processes,
the specific natural bacteria that cause these transformations were isolated.
Recent progress has allowed culturing, drying, and preserving a wide variety
of natural bacterial strains to perform many chemical synthesis and waste
treatment operations.
Dried bacterial cultures are available to decompose oil, gasoline, grease, and
various organics. Normal mutation that occurs in the bacterial population has
led to isolating and culturing tolerant mutant strains of bacteria that will
break down normally difficult to treat or slow degrading wastes such as pesti-
cides, chlorinated organics, phenols, and dioxins.
Addition of selected bacteria to treatment units (such as activated sludge
systems or anaerobic digesters) in sanitary plants greatly improves the
efficiency and ability of these plants to handle industrial-type wastes ard
remain within permit limits.
Selected bacteria have potential applicability for in situ treatment of mate-
rials released to the environment. The cleanup of oil spills on coastal areas
is dramatically enhanced by application of oil-digesting bacteria. In situ
biological remediation combined with pump-and-treat methods can also be
enhanced by the addition of selected bacterial strains specific to the
selected waste type (PolyBac Corporation, 1989). The limitations -en using
naturally selected bacteria are those imposed by the methods of application
(i.e., trickling filter, in situ treatment, activated sludge, etc.).
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Naturally selected bacteria would have limited effectiveness in treatment of
the low concentrations of chlorinated organics in the Firestone Salinas ground
water. As stated in other sections, bacteria are slow in degrading chlorin-
ated organics. Furthermore, the aquifers at the Firestone Salinas site are
not idaally suited for in situ biological treatment due to high recharge
rates. It would not be economical to consider surface biotreatment of pumped
ground water due to residence time and large holding volume. Thus, no further
consideration will be given to this treatment method for implementation at the
Firestone Salinas site.
Genetically Engineered Bacteria
A new frontier has developed as a result of advances in molecular biology.
Recombinant DMA techniques have allowed the joining of DNA fragments from
different organisms. Inserting these new ONA fragments into a bacteria give
the cells new genetic information. The new instructions can cause the cell to
produce chemical materials or perform conversions that were not normally part
of its former life function. Although this technology is in its infancy,
great benefits have already been derived from its application. The synthesis
of human insulin and other hormones, and the production of vaccines and vita-
mins are' just a few of the commercial applications.
The major drawback with this technology is the potential danger and contro-
versy associated with the creation of these new life 'forms. Synthesis
reactions involving genetically engineered bacteria are carried out in closed
vessels. The bacteria are "sterilized" or removed before the products are
recovered to prevent environmental release. The application of genetically
manipulated bacteria to waste or in situ treatment is currently restricted
until the controversy and safety issues are resolved. Only one commercial
application of environmentally released, genetically engineered bacteria has
been allowed to date. This was a test involving a bacteria engineerec to
prevent frost damage to strawberries. Until the controversy and safety issues
are resolved, further development for waste treatment applications are at a
standstill.
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Genetically engineered bacteria are unavailable for the treatment of the types
of dissolved chlorinated organics in the Firestone Salinas ground water.
Thus, no further consideration will be given to this treatment method for
implementation at the Firestone Salinas site.
2.4.3.6 Composting
Composting is an aerobic treatment method used to treat primarily high solids
sludges or solid waste. The method involves simply piling organic-containing
waste and allowing natural aerobic bacteria to grow and decompose the solid
waste material. Refinery sludges and municipal sludges may be effectively
treated this way. Often this method is referred to as landfarming. Turning
over piles (tilling) enhances bacterial action and growth and serves to aerate
the soil. Adding lime helps condition the soil and balance the pH. Nutrients
may be added to encourage optimum bacterial growth and waste breakdown. The
products are gases, usually carbon dioxide and steam, and a liquid leachate
which may contain partially oxidized organics or heavy metals (Berkowitz et
al., 1978). If the waste contains primarily organic constituents, sludge
disposal from the compost bed will not be necessary. The organics will be
either completely oxidized and be removed as gases or left in the leachate.
Compost piles must be slightly wet for the bacteria to begin functioning.
Usually enough water is produced by the decomposition to sustain the bacteria
until the composting is completed. Composting will also proceed
anaerobically, as demonstrated in municipal landfills. The products from
anaerobic composting are methane, some carbon dioxide, traces of volatile
organics, and water. On a large scale, methane is usually extracted by
installing wells in the landfill. The gas is then recovered, purified, and
sold as a medium to high BTU gas product. The primary costs involved in
composting are transportation to the composting site, labor and equipment
costs to move and till waste material, collection and disposal (or treatment)
of leachate, and the cost of a land parcel and any necessary improvements.
Improvements may include a concrete slab or liner to assist leachate
collection and prevent ground-water contamination.
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Composting would not be applicable to treatment of the Firestone Salinas
ground water since it is only a treatment method suitable for solid waste
material. Thus, no further consideration will.be given to this treatment
method for implementation at the Firestone Salinas site.
2.4.3.7 Aquaculture
A novel treatment method for treating relatively dilute aqueous wastes is
aquaculture treatment. Several species of aquatic plants are well adapted for
absorbing waste materials from waste streams; in particular, those wastes
containing nutrients such as available nitrogen and phosphorous. Water
hyacinths are a menace when they clog navigation channels. However, the
characteristics that make them a menace in open waters make them ideal for
waste treatment. These plants are rapid growing. They have long, fine fila.-
mented roots that hang down as deep as 4 feet from the floating plant on the
surface. Allowing these plants to grow over a large treatment lagoon provides
an efficient way to detoxify large volumes of waste water. The root filaments
trap or consolidate fine particulates which settle to the bottom of the
basin. The plants absorb soluble pollutants and incorporate them into plant
mass. BOD, suspended solids, and metals can be reduced by hyacinth treat-
ment. Not all pollutants are destroyed, some being concentrated in the plant
tissues. Also, periodic harvesting of the plants is necessary. The plants
are much easier to handle and dewater than conventional sewage sludges. The
plants are non-odorous and can be transported in dump trucks. . They are self-
dewatered when placed in a landfarm and biodegrade aerobically. The applica-
tion of aquaculture is competitive with other processes. The technology is
not as suitable for cold climates. Lower temperatures slow down the growth
rate of the plants. Also, prolonged freezing temperatures will kill off
unprotected plants. The simplicity and added.benefits of this technology make
it attractive. However, aquaculture is still an emerging treatment method
(Hesby, 1983). There is limited data available on the ability of the plants
to remove synthetic organic hydrocarbons.
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Aquaculture treatment would not be appropriate for treatment of the Firestone
Salinas ground water. The large land area required for treatment ponds, the
low concentrations of nutrients in the ground water, and unconfirmed ability
of the cultivated plants to treat or remove chlorinated organics make the
method unsuitable and uneconomical. Thus, no further consideration will be
given to this treatment method for implementation at the Firestone Salinas
site.
*
2.4.4 Thermal Treatment
Thermal treatment is destruction of hazardous waste materials (solid, liquids,
gases, sludges, tars, etc.) by high-temperature heating. There are a number
of different thermal treatment technologies. These can be grouped into the
following five categories:
• Thermal oxidation (incineration)
• Thermal degradation (calcination)
• Vitrification (glass encapsulation)
• Plasma pyrolysis (complete atomic disassociation)
• Nuclear destruction (fission, fusion, or high energy bombardment
reactions causing sub-atomic disassociation).
Thermal treatment would not be economical for treatment of the dilute concen-
trations of chlorinated organic hydrocarbons in the Firestone Salinas ground
water. However, for information purposes, brief discussions .of each of the
methods are presented.
2.4.4.1 Thermal Oxidation (Incineration)
Thermal oxidation is the reaction of waste material with oxygen in the gas
phase. This is a common treatment method for.liquids such as solvents, fuels,
oils, etc. It is also appropriate for combustible gases and solids (such as
municipal trash or rubber scrap). Treatment is performed in units designed
with good air flow and adequate residence time to allow for complete destruc-
tion. Units may have additional fuel sources to maintain temperature when
treating low BTU waste material. Thermal oxidation units include liquid
injection incinerators, industrial boilers, and kilns (for some wastes),
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rotary kiln incinerators, fluidized bed incinerators (relatively new tech-
nology), fixed or multiple hearth incinerators (used for incineration of
municipal waste) and flare stacks. Operating temperatures are usually in the
range of 1,600 to 2,400°F.
2.4.4.2 Thermal Degradation (Calcination)
Thermal degradation or calcination is a process that degrades waste materials
by thermally induced chemical transformations other than oxidation. The
process is best suited for solid waste treatment. During calcination, water
and organics are driven off, and the organics are thermally destroyed. Reac-
tion gases may also be driven off, such as hydrogen sulfide or carbon dioxide.
The inorganic waste material remaining after treatment is in a more suitable
form for disposal. The process is suitable for treating contaminated soils,
certain concentrated liquids, sludges, and tars. The process has also proven
effective for the concentration and solidification of radioactive waste
liquids and solids. The process is used commercially in smelting of some ores
and manufacture of cement products. Unit configurations include rotary kiln
furnaces, fluidized beds units, open and multiple hearth furnaces, and
refinery coker units. Operating temperatures are in the range of 1,200 to
2,500'F (Berkowitz et al., 1978).
2.4.4.3 Vitrification
Vitrification is a combination thermal treatment process and encapsulation
process. Waste materials are mixed with appropriate inorganic refractories
(silica, alumina, etc.) or simply heated (depending on the waste material).
The material is heated hot enough to melt or fuse the inorganic components
into a glass. The waste material is either micro encapsulated by the glass or
reacts to help form the glass. Organic components in the waste are driven off
and thermally destroyed. < The waste after treatment is stable and suitable ^or
land burial. -Units for vitrification treatment include rotary kilns, molten
salt units, and molten glass furnaces. Operating temperatures depend on the
materials to be treated but are usually high.
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An alternate version of This process is in situ vitrification. In this
process electrodes are inserted into the ground with a graphite linkage
between the electrodes. A current is applied that heats the graphite.
Eventually the graphite is hot enough to melt and fuse the inorganics to form
a molten*vitrified glass. Once molten, the glass acts as the conductor and
the graphite burns off. .Organics may be destroyed or driven off. teachable
inorganics are either fused or encapsulated. Melts as large as 800 tons have
been performed. Treatment of soil to depths of 50 feet is being considered.
The economics are competitive with alternative treatments.
The glass may take as long as a year to cool and there are some other tech-
nical considerations. The process is a promising method for treatment of
radioactive wastes and waste sites where digging .up of soils would be haz-
ardous or impractical. The process can generate in soil temperatures, in
excess of 3,600°F (Buelt et al, 1982).
2.4.4.4 Plasma Pyrolysis
Plasma pyrolysis is an emerging treatment method that destroys a waste by
passing it through a plasma gas stream. An electrode assembly is used to
energize a gas stream. The gas reaches temperatures between 5,000° and
15,000°C. Liquid waste heated by the plasma is completely disassociated. It
then reforms, into gases, such as carbon monoxide, nitrogen, carbon dioxide,
hydrogen, etc. The gases are scrubbed, then flared to the atmosphere.
Destruction efficiency is extremely high. Currently the technology is limited
to pumpable liquids at treatment rates of about 3 gpm. Energy consumption is
high (Cheremisinoff, 1988).
2.4.4.5 Nuclear Destruction
Uncontrolled thermonuclear reactions produce temperatures exceeding 20 million
degrees centigrade. There is no doubt that complete destruction of waste
materials would occur at these temperatures. Although an uncontrolled nuclear
reaction is absurd for use as a waste treatment method, development of
controlled fusion technology may provide an answer to conventional and radio-
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active waste problems in the future. Nuclear reactors and high energy physics
units may be used to convert some dangerous, long lived isotopes into shorter
lived, less hazardous species. Currently this is not economical for large-
scale treatment.
This method is also presented to show the progression of thermal treatment
destruction mechanisms depending on the temperature and energy level.
Destruction reactions at lower (energy) temperatures proceed by molecular
rearrangement and breaking molecular bonds. Higher temperatures (increasing
energy level) break materials down into atomic components (as is found in
plasma processing). At still higher energy (nuclear) and temperatures,
reactions occur at the subatomic level.
No further consideration will be given to any of the thermal treatment methods
for implementation at the Firestone Salinas site.
2.4.5 Dispersed Treatment
The dispersed treatment option would locate treatment systems at remote loca-
tions near extraction wells. Each system would operate independently,
although transmission of operations performance parameters may be sent to a
central location or recorded remotely. Each treatment system would process
ground water independently. It may be cost effective to combine some of the
discharges from remote units into pipeline headers and send to single or
multiple remote locations for discharge (i.e., the Salinas River). The number
of treatment units would be determined by optimum, pumping requirements and
well locations.
There are several disadvantages to dispersed treatment. Multiple treatment
units would require added sampling to verify performance of each system.
Maintenance and labor costs would be increased in order to attend to multiple
pieces of equipment (performing the same function). Security at nultiole
remote locations would be more difficult to maintain. The large lane
requirements may make it difficult to obtain permission from property owners
to utilize larger areas of their property.
»
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Although additional costs may be incurred to install piping to a central loca-
tion, these costs would be somewhat offset by the economics and greater effi-
ciency with a single, larger treatment system. Installation of utilities at
multiple locations to support operations would be more expensive than if
utility services are provided to a single location.
Dispersed treatment would not be efficient or economical for treatment of
Firestone Salinas ground water. Thus, no further consideration will be given
to the dispersed treatment option for implementation at the Firestone Salinas
site.
2.4.6 Centralized Treatment
The existing centralized treatment system has demonstrated that a central
treatment system is secure and efficient.' The existing centralized treatment
system located within the Firestone Business Park has a proven performance and
safety record. The location provides a high degree of security due to the
presence of security at the Business Park entrance and operating personnel on
a 7-days-per-week basis. The existing treatment system is attended during off
hours by a telephone paging system tied into operations' monitors. Personnel
are available at all times during off hours to respond. The operations record
of this installation demonstrates performance that would likely be unmatched
by multiple remote units.
A centralized treatment system is the only type of installed remediation
equipment considered further for treatment of ground water at the Firestone
Salinas site. Further evaluation is included in Sections 3.0 and 4.0.
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3.0 DEVELOPING REMEDIATION ALTERNATIVES
3.1 RELEVANT SITE CHARACTERISTICS
The site characteristics relevant to the remediation of the affected ground
water at the Salinas site include the aquifer system, the site hydrogeology,
and the geochemical nature of the ground water. These characteristics are
discussed in the following paragraphs. Appendix F provides additional data on
aquifer characteristics.
The ground-water aquifer system in the immediate vicinity of the facility is
within three interconnected zones that are designated shallow, intermediate,
and deep. The shallow aquifer extends from the surface to a depth.of about
90 feet. The intermediate zone is about 40 feet thick and is generally
located from 100 to 140 feet below the surface. The deep aquifer system
locally has four distinct zones at 200-, 300-, 400-, and 500-foot depths. The
various water-bearing zones are separated from one another by clay or silt
layers (aquitards) that have varying thicknesses and are locally discontin-
uous. Where the aquitards are thin or discontinuous, flow can occur between
the aquifers above and below the aquitard. The shallow aquifer has limited
use because of its limited capacity during drought years. The intermediate
zone has limited use because it is not thick and, therefore, does not yield a
large quantity of water. The deep zone is extensively developed for agri-
cultural and some domestic use.
Ground water in the aquifer system around the Firestone site flows generally
northwesterly. In the shallow aquifer (Figure 3-1), the local flow direction
from the former Firestone facility is westerly. At a distance of about 3,000
feet to the west, the flow direction resumes the regional northwesterly trend.
On the basis of the hydrogeologic work done for the remedial investigation,
the pathways of chemical movement (Figure 3-2) appear to be limited laterally
to local ground-water channels. The edges of these channels are of much lower
permeability and act as an impediment to the lateral spread of chemicals in
the ground water near the site. Within the layered vertical structure of the
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aquifers there are vertical components to the flowpaths as well. When the
agricultural wells are pumping, they create a downward flow component between
aquifers.
At the site itself and for a distance of about 3,000 feet to the west, the
aquHard under the shallow aquifer prevents downward flow. However, the aqui-
tard is discontinuous to the west, where there is a downward diffusion from
the surface aquifer into the underlying intermediate zone. The result is that
dissolved chemicals in the surface aquifer are mixed and diluted as they dif-
fuse downward to and through the intermediate zone.
Still farther to the northwest, about 6,000 to 7,000 feet from the former
Firestone facility, the aquitard under the intermediate zone thins and allows
further diffusion downward into the uppermost, or 200-foot, unit of the deep
aquifer. The subsequent zone of dilution in the deep aquifer extends about
1,500 to 2,000 feet to the northwest. Again, regional ground-water flow
further dilutes the dissolved chemicals migrating downward from the shallow
and intermediate units.
Finally, there is a vertical flow component between the 200-foot unit to the
deeper units when the agricultural wells are pumping. Clay aquitard layers
between the 200-, 300-, 400-foot, and deeper water-bearing units are locally
discontinuous, allowing additional downward diffusion and subsequent dilution.
This zone of diffusion begins about 2 miles northwest of the former Firestone
facility.
Ground water has been sampled extensively throughout the area surrounding the
site. Each of the agricultural and domestic wells within 4 miles downgradient
(northwest) of the site was located, verified, and sampled where access was
obtained. On-site and off-site monitoring wells were also installed to assess
the horizontal and vertical extent of chemicals in the ground water and the
horizontal and vertical flowpaths. As a result of these samples, combined
with each of the other investigations done, the nature and extent of chemicals
in the ground water have been defined.
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Chemical analyses of the wells in the vicinity have provided a good under-
standing of the concentrations of each specific chemical in the list of
chlorinated aliphatic hydrocarbons and volatile aromatic hydrocarbons given
previously. Since the analyses have been repeated over time, a good history
of the concentration changes in any given well exists. This history can be
related, in some cases, to the performance of the shallow aquifer ground-water
extraction wells and treatment plant. Finally, the concentration data,
combined with the hydrogeologic investigations, have determined the vertical
and horizontal extent of chemicals associated with the former Firestone
facility in the ground water.
Of the ten indicator chemicals (Appendix G) defined by the California
Department of Health Services (DHS) for study at the beginning of Firestone's
cleanup activities, three have been detected most frequently in limited areas
of the ground water: 1,1-DCA, 1,1-OCE, and 1,1,1-TCA (Appendix H). The
latter two are the most reliable indicators of the presence of chemicals
because they are found in more wells than is the 1,1-DCA. Samples taken
during the beginning of the extraction well field and water treatment plant
operations show, at worst, no increase in concentrations and, at best, a
decrease in concentrations for each of these chemicals (Appendix I). This
suggests that the extraction wells have stabilized the plume of contamination
and are reducing the concentration levels in some areas. The largest reduc-
tions have been made in the on-site locations with the highest original
concentrations.
Samples from monitoring wells and from agricultural, domestic, industrial, and
municipal wells show that the chemical plume ends about 2% miles from the
former Firestone facility. The plume of chemicals in the ground water
(chemicals detected above the method detection limits) can be described as
follows, starting at the former Firestone facility:
• A narrow ellipse 3,000 feet long and 1,000 feet wide, in the shallow
aquifer, flowing almost due west
• A second narrow ellipse 4,000-feet-long and 1,000-feet-wide, in the
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intermediate zone, flowing northwest
• 'A third ellipse 7,000 feet long and 1,500 feet wide, in the deep
aquifer, flowing northwest.
Plumes of 1,1-OCE and 1,1,1-TCA in the various aquifers are shown in Figures
3-3 through 3-8. The data upon which these plumes are based were collected in
the:first quarter of 1989. As shown in these figures, the plume is laterally
confined to alluvial channels. This is discussed in detail in the Remedial
Investigation report (IT, 1988a). These plumes and the extensive hydro-
geological studies reported earlier are the basis for 'location of the
extraction wells as discussed in Section 3.2.
Concentrations of 1,1-OCE and 1,1,1-TCA are used throughout this report as
indicators of remedial trends for all the chemicals found at the site. The
reasoning behind this is:
• Continual observations in the we-lls monitored suggest that concen-
trations of all chemicals will drop below their action levels, and
often the detection limits as well, before 1,1-OCE levels reach the
6 ppb California DHS Action Level, the cleanup level chosen for this
compound.
• Monitoring and reporting of 1,1,1-TCA levels is done because that
compound is the precursor to 1,1-OCE actually found. The degradation
of 1,1,1-TCA to 1,1,-OCE is discussed in Section 1.4.3 of this FS/RAP
report.
3.2 EXTRACTION ALTERNATIVES
Review of the plume maps (Figures 3-3 and 3-4) shows that the currently
operating, shallow aquifer extraction wells, S-7, S-8, S-10, S-ll, M-l,
IT-SE2, IT SE3, IT-SE4, and IT-SE5 are located in the areas of the shallow
aquifer plume with the highest concentrations. (Extraction well S-9 is very
shallow and is not currently operating.) Thus, no modifications of locations
were needed for the shallow aquifer remediation.
The plume maps for the 120-foot aquifer (Figures 3-5 and 3-6) show some wells
above the cleanup levels presented on page 2-6. Thus, a series of potential
locations for extraction wells was considered to be installed into the
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intermediate (120-foot) aquifer. The potential well locations considered are
shown as wells IT-IE-1 through IT-IE-10 in Figure 3-9. These wells were
located on the basis of the following criteria:
• Relatively high concentrations of chemicals in the ground water
• Anticipated high-permeability geological flow channels (this will be
confirmed during installation of the wells)
• Relative ease of access, where possible, for complete coverage of the
plume.
From these potential locations, six combinations of well locations were
analyzed. These combinations are listed in Table 3-1, and the well locations
and flowrates are shown in Figures 3-9a through 3-9f. These combinations
include configurations aligned along the axis of the chemical plume, perpen-
dicular to the axis, a diamond pattern over the plume, and a cross with the
long leg along the axis of the plume and the short leg across the axis.
Computer simulations were made for each of these combinations. The most
efficient remedial alternative was Alternative 6, listed in Table 3-1. This
alternative consists of five extraction wells aligned along the axis of the
plume in the 120-foot aquifer.
This extraction alternative was used to develop the site-specific remedial
action alternatives discussed in Section 3-5. Figures 3-10 through 3-13 show
the extraction well locations for each remedial action alternative. The other
extraction alternatives in Table 3-1 were screened from additional
consideration.
3.3 TREATMENT ALTERNATIVES
The five treatment alternatives that have been identified as. possible
strategies to be evaluated for implementation at the Firestone Salinas site
are as follows:
• Activated carbon treatment
. • Air stripping
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« Natural or enhanced dilution/degradation
• Combined strategies
• Agricultural spraying.
These will be discussed individually in this section and evaluated in detail
as these alternatives are part of the site-specific remedial action alterna-
tives." in Section 4.0.
3..3.1 Activated Carbon Treatment
As part of interim remediation measures, Firestone installed two 20,000-pound
capacity activated carbon adsorbers. These two units are piped to operate in
series and have a continuous treatment capacity of 500 gpm. The units are
charged with virgin activated carbon. Currently, a majority of the ground
water pumped from the extraction wells, is routed through the carbon units,
and returned to the Salinas River through a 14-inch diameter outfall.
Monitoring of the concentrations of organic contaminants in the influent,
between the beds, and effluent is used to determine the frequency of carbon
replacement. Carbon replacement is a simple operation requiring minimal
downtime. Spent carbon is sent for regeneration back to the supplier. The
existing carbon unit has demonstrated high efficiency and reliability for the
Firestone Salinas ground water. Thus, activated carbon treatment is
appropriate, should continued treatment be required.
3.3.2 Air Stripping
An air stripper column was installed at the Firestone Salinas site as part of
the interim remediation measures that were implemented. The intent of the air
stripper originally was for pretreatment of ground water before processing
through the carbon unit. The existing air stripper has performed exception-
ally well and has demonstrated that air stripping treatment -alone is capable
of removing the volatile organic contamination in the Firestone Salinas ground
water below the NPOES permit levels for discharge of water into the Salinas
River. The Firestone Salinas air stripper has features that optimize
performance and economy. These include a redistributor within the column,
high efficiency tower parking, and a variable speed blower. Air stripping has
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demonstrated greater economy over carbon treatment. The local air district
allows direct discharge of the stripper exhaust to the atmosphere within
permitted limits.-
The permitted limit and hydraulic capacity are the current limitations on the
existing air stripper. The treatment capacity of the air stripper is cur-
rently limited to 180 gpm. The performance of the existing air stripper has
demonstrated that air stripping is appropriate, should continued treatment be
requ i red.
3.3.3 Natural Biological Degradation/Dilution
Natural biological degradation of most chlorinated synthetic organics occurs
very slowly in the environment. The problem is two-fold. First there are
limited bacterial species that can perform this type of conversion.. Some
chlorinated organic compounds are not degraded to any significant degree in.
the environment because they are not usable by the available natural bacteria.
Enhancing bacterial action by supplying a specific strain is limited to
finding suitable strains of bacteria that will perform the conversion.
The second problem is the deficiency of nutrients to stimulate bacterial
growth. Chlorinated organics are usually found in very dilute concentrations
when released into the environment. Without additional nutrients, natural
bacteria grow and reproduce very slowly. The limited numbers of cells would
degrade chlorinated organic materials at a very slow rate. Aromatic hydro-
carbons also occur in very dilute concentrations in a limited area of the
site. They can be degraded, but they are not widespread throughout the plume.
They occur primarily near the southwest corner of the building.
Due to these two limiting factors, relying only on natural degradation of the
chlorinated organics in the Firestone Salinas ground water would require many
years for concentrations in the ground water to return to acceptable levels.
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The aquifers beneath the Firestone site are high quality and possess reason-
able permeability. Natural dilution, removal, and recharge will be the
primary means for lowering organic concentrations in the various aquifers.
Even without operation of extraction wells, tremendous quantities of water are
removed from beneath the site by agricultural water wells. Some of these
wells draw from both shallow and deep aquifers. Additionally, natural
recharge of the aquifer from the Salinas River and from the surrounding
mountains dilutes ground water significantly. Although the process may
require several years, natural and induced dilution and flushing of the
aquifer would eventually bring organic contamination levels down to acceptable
levels.
3.3.4 Combined/Additional Strategies
Under the interim remediation strategy, an air stripper and an activated
carbon unit were installed to be operated in series (Figure 3-14). Two
processing units were proposed for economy and environmental protection. Air
stripper treatment before carbon treatment of a process stream would extend
the life of the carbon significantly. Since operation began, it was demon-
strated that air stripping or carbon treatment alone are both effective in
removing the volatile contamination in extracted ground-water streams.
Balancing of flows by directing streams with high concentrations preferen-
tially to the air stripper has maximized plant treatment capacity and mini-
mized carbon changeout cost. The current plant capacity is 650 gpm and
requires carbon changeouts only twice per year, with the current
concentrations.
Air stripping is more economical and equally effective as carbon treatment.
In hindsight, the carbon unit would not be necessary providing an air permit
were obtainable to discharge all pollutant exhaust from a larger air stripper
to the atmosphere. However, to meet treatment capacity requirements, the
economics does not justify replacement of the existing carbon unit with a new
air stripper this late in the project (based on projected cleanup scenarios).
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Other possible combined treatment alternatives, although effective, would not
be economical when compared against the inherent value and operating cost of
the existing treatment system.
3.3.5 Agricultural Spraying or Flooding
Aeration by agricultural spraying or flooding is a "simple means to remediate
the ground water. This is currently being done defacto from the deep aquifers
on an intermittent basis. There are, however, several restrictions that limit
the usefulness of this alternative as a continuous process.
Agricultural consumption of water will not coincide with the water supply,
thus requiring storage of water or shutdown of wells. Agricultural spraying
is only performed on young crops. Furrow irrigation is the preferred method
of irrigation for. most of the growing season. Agricultural spraying or
flooding is a good way to utilize extracted ground water, but again the demand
is not always constant.
The hydrogeology of the area shows that the Salinas River as well as the
surrounding mountains recharge the underground aquifers. Pumping treated
water to the river simply returns the ground water to be used as required by
agricultural consumers upon demand. Simply pumping to the river is more cost
effective and minimizes any adverse public reaction to other water uses.
Agricultural spraying is considered further in Section 4.0, with respect to
the deep aquifer.
3.4 DETAILED ANALYSIS OF DISPOSAL ALTERNATIVES
This section briefly describes and analyzes disposal alternatives for the
treated ground water at the former Firestone facility. These disposal alter-
natives are as follows:
• Alternative S: Stream disposal - Section 3.4.1
• Alternative T: Injection - Section 3.4.2
• Alternative U: Holding ponds., lagoons, or basins - Section 3.4.3
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The discussion for each disposal alternative includes identification and
summary of the alternative, advantages and disadvantages of the alternative,
and the procedure for monitoring treatment plant affluent concentrations.
3.4.1 Alternative S - Stream Disposal
Alternative S is the discharge of treated ground water to the Salinas River
channel. This is the alternative implemented during the interim remedial
measures started in February 1986 and continuing to the present (1989).
This alternative consists of pumping the treatment plant effluent into a
pipeline, approximately 1 mile long, which runs from the treatment facility at
the former Firestone facility to a discharge point at the Salinas River. An
NPDES permit was obtained for a maximum discharge of 1000 gpm and startup
flows not to exceed 250 gpm. The Salinas River generally has limited flow.
During the high water seasons, the river flows directly into the Monterey Bay;
however, the majority of the time the river is intermittent and water infil-
trates into the ground before it reaches the bay.
Discharging into stream channels has been used for many years for the disposal
of various treated waste water. There are several advantages of this disposal
alternative. The treated wastewater at the former Firestone facility consists
of clean water and is returned for future use. That is, there is no consump-
tive use of the water, except for a very small loss in the air stripper and in
the effluent tank (14 gallons out of 775,000 gallons treated daily). Clean
water returned to the aquifer does not place limitations on the water use,
which is an important advantage of this alternative. Another advantage of
this disposal alternative is that the NPDES permit required for disposal has
already been issued. It will only require renewal.
A disadvantage of this alternative is that there is a small loss of water
through evaporation and evapotranspiration after the water is discharged into
the Salinas River and before it infiltrates into the river bed.
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For this alternative, the discharge water is monitored at the treatment
facility and at the river outfall, and discharge into the river would be
discontinued immediately, if effluent concentrations were found to exceed
limits listed in the NPDES permit.
3.4.2 Alternative T - Injection
Alternative T consists of injection of the treatment plant effluent into the
aquifer from which it was withdrawn. The injection of liquid wastes, in this
case treated ground water, has been widely adopted as a common waste disposal
practice in the United States. The most common type of injection well is that
used to return brine extracted during oil and gas field pumping. The purpose
of the procedure is to iso.late the substance from the biosphere. In the case
of injection wells at the former Firestone facility, the purpose would be to
return clean usable water to the aquifer for downgradient uses.
The advantages of injection are that there is no evaporation of the water,
clean water returned to the aquifer does not place limitations on water use,
and discharge pipelines can be avoided.
However, there are several drawbacks in the use of injection wells for dis-
posal. Well plugging is very common and requires that the well be taken out
of service and treated before it can be returned to use. An example of this
type of problem occurred at the Ashworth Brothers Metal Plating Co. located
approximately 3 miles upgradient of the former Firestone facility. Addition-
ally, if water with different chemical characteristics is returned to an
aquifer, the result can be the dissolution of unwanted minerals that can
degrade the quality of the ground water, possibly affecting its use. This
alternative would require a new NPDES permit and, consequently, preparation of
the associated application documents, public hearings, meetings, and the
required time for regulatory review.
For this alternative, the water being discharged into the injection well would
be monitored at the treatment facility, and discharge would be discontinued
»
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immediately, if effluent concentrations were found to exceed limits listed in
the NPDES permit.
3.4.3 Alternative U - Holding Ponds, Lagoons, or Basins
Alternative U consists of discharging the treatment plant effluent into hold-
ing ponds, lagoons, or basins, which allow the water to infiltrate into the
ground and to evaporate. This type of operation has been a common waste dis-
posal practice for many years. The liquid waste, in this case treated ground
water, is placed in unlined ponds, lagoons, or basins and allowed to infil-
trate into the ground or to evaporate, either directly or by evapotranspira-
tion. The reason for using this method at the former Firestone facility would
be to return clean, usable water to the aquifer for downgradient uses.
Ponds, lagoons, and basins have been used for many years for the disposal of
various treated waste water. The following are some of the advantages. The
treated waste water, which consists of clean water at the former Firestone
facility, is returned for future use. Clean water returned to the aquifer
does not place limitations on water use, and extensive discharge.pipelines can
be avoided.
The major drawback in the use of this alternative for waste water disposal at
the former Firestone facility is the potential flooding of some of the nearby
farmland, which is at a lower elevation than the holding pond.s, lagoons, or
basins. Crops with critical water needs are grown near the facility/ and could
be harmed by excessive water. Additionally, during harvest times, saturated
ground would make the use of farm equipment difficult. A further concern
would be the plugging of the bottom of the ponds, lagoons, or basins. This
would require that the operation be stopped until the problem was corrected.
Also,-, the chemical characteristics of the water can change as it percolates
downward. The result can be the dissolution of unwanted natural minerals that
can degrade the quality of the ground water, thereby making it unusable.
Also, water can be lost for reuse by evaporation or evapotranspiration. This
alternative would require a new NPDES permit, with the concomitant public
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hearings, meetings, and time required for regulatory review, (minimum of 180
days).
For this alternative, the water being discharged into the ponds, lagoons, or
basins would be monitored at the treatment facility and at the outfall with
discharge being discontinued immediately if effluent concentrations are found
to exceed limits listed in the NPDES permit.
3.4.4 Summary of Discharge Alternatives
Alternative S, discharge of treated ground water to the Salinas River, is
considered the most appropriate and the most time and cost-effective disposal
alternative for the Firestone site, based on IT's analysis of the three alter-
natives. Alternative S is protective of the environment, returns a natural
resource for future use, and does not have the potential environmental proo-
lems associated with Alternatives T and U. Alternative S returns clean water
to the aquifer, and the NPDES permit required for this disposal alternative
has already been issued. The discharge water is monitored at the treatment
facility and at the river outfall, and discharge into the river is discon-
tinued immediately if effluent concentrations are found to exceed limits
established in the NPDES permit.
Alternative T consists of injection of the treatment plant effluent into the
aquifer from which it was withdrawn. Although Alternative T returns water to
the aquifer, there are a number of potential problems associated with this
alternative, including the following:
- Well plugging is very common.
Injection of water with different chemical characteristics into the
aquifer can result in dissolution of unwanted minerals and degrada-
tion of ground-water quality.
Alternative T would require a new NPDES permit (minimum of 180 day
processing). Potential well plugging would increase down time for the
treatment plant.
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Alternative V consists of discharging the treatment plant effluent into hold-
ing ponds, lagoons, or basins, which allow the water to infiltrate into the
ground or to evaporate. This alternative would also return water to the
aquifer, but potential environmental drawbacks include the following:
° Potential flooding"of nearby farmland
° Potential adverse effects of excessive water, including effects on
crops;wi'th specific water requirements"and difficulties in the use of
farm equipment on saturated ground
• Potential for plugging of the bottom of the ponds, lagoons, or basins
• Potential for dissolution of unwanted minerals and degradation of
ground-water quality.
This alternative would also require a new NPDES permit, with the concomitant
public hearings, meetings, and time required for regulatory review (minimum of
180 days).
3.5 SITE-SPECIFIC REMEDIAL ACTION ALTERNATIVES
As discussed in the previous sections, the treatment alternatives have been
screened to carbon adsorption, air stripping, or a combination of these. The
disposal options were screened to discharge into the Salinas River. The
extraction alternatives consist of combinations of pumping from the shallow
and intermediate aquifers, and different .schedules to initiate pumping from
each aquifer.
The experience gained from operating the interim remedial measures since early
1986 demonstrates that the recovery can be optimized by allowing the site
manager a large degree of flexibility in adjusting the flowrates in the
individual wells on the basis of the monitoring data. The general criteria
used by the site manager are as follows:
• Maximize the flowrate from affected wells up to a comoined flowrate
equal tc the treatment plant capacity
• Cycle the pumping rate, if this proves to be efficient in remediation
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• Pump the highest flow from the wells with the highest concentrations
of chemicals
• Discontinue pumping as the concentrations in a well decrease to the
cleanup levels, and possibly sooner if there is an adjacent or
downgradient well that will capture the chemicals faster
• Direct the flowstream with the highest concentrations to the
airstripper and the lowest flowstream to the carbon adsorption unit.
These procedures allow maximizing the recovery from the aquifer.
3.5.1 Approach
The primary objective of the feasibility study remedial action plan is to
ensure that appropriate remedial alternatives are developed and evaluated that
protect human health and the environment and are appropriate to the site's
problem. The EPA Draft Guidance for Conducting Remedial Investigations and
Feasibility Studies Under CERCLA (March 1988, hereinafter referred to as EPA
RI/FS guidance document) provides guidance for development of alternatives.
Although the risk assessment (IT, 1988b) has shown there is no unacceptable
health or environmental risk, this guidance document was followed.
Alternatives for remediation are developed by assembling combinations of
technologies into alternatives. This process of six general steps is briefly
discussed below:
STEP 1 - Develop remedial action objectives specifying the contaminants
and media of interest, exposure pathways, and remediation goals that
permit a range of treatment and containment alternatives to be
developed. The objectives developed are based on contaminant-specific
ARARs, when available, and risk-related factors.
STEP 2 - Develop general response actions for each medium of interest
defining containment, treatment, excavation, pumping, or other actions,
singly or in combination, that may be taken to satisfy the remedial
action objectives for the site.
STEP 3 - Identify volumes or areas of media to which general response
actions might be applied, taking into account the requirements for
protectiveness as identified in the remedial action objectives and the
chemical and physical characterization of the site.
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STEP 4 - Identify and screen the technologies applicable to each general
response action to eliminate those that cannot be implemented
technically at the site. The general response actions ' are further
defined to specify remedial technology types (e.g., the general response
action of treatment can be further defined to include chemical or
biological technology types).
STEP 5 - Identify and evaluate technology process options to select a
representative process for each technology type retained for
consideration. Although specific processes are selected for alternative
development and evaluation, these processes are intended to represent
the broader range of process options within a general technology type.
STEP 6 - Assemble the selected representative technologies into
alternatives representing a range of treatment and containment
combinations, as appropriate.
Step 1 has been performed in the RI. The other steps are discussed in
Section 2.0 of this FS/RAP. The remaining activity required in developing
alternatives is combining and assembling representative technology process
options to specific alternatives. At a minimum, EPA guidance states that at
least one representative process option from each technology identified as
potentially applicable should be developed.
The "Site Mitigation Decision: Tree" and the current NCP rule state that
developed alternatives should include the following:
• .A no-action alternative
• Alternatives involving off-site treatment or disposal
• Alternatives that attain applicable or relevant public health or
environmental standards
• Alternatives that exceed applicable or relevant public health or
environmental standards
• Alternatives that do not attain applicable or relevant public health
or environmental standards but which meet CERCLA's objective of
adequately protecting public health, welfare, and the environment.
The proposed rule and draft guidance do not specify that alternatives identify
different levels of ARAR attainment, but rather concern themselves with the
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time required to reach remediation goals. The proposed rule was considered in
this FS/RAP because it indicates current regulatory direction.
This FS/RAP study is limited to the remediation of contaminated ground
water. As such, the remediation effort can be considered to be a ground water
response action. The draft EPA RI/FS guidance document states that:
For ground water response actions, alternatives should address not only
cleanup levels but also the time frame within which the alternatives
might be achieved. Depending .on specific site conditions and the
aquifer characteristics, alternatives should be developed that achieve
ARARs or other risk-based levels determined to be protective within
varying time frames using different methodologies. For aquifers
currently being used as a drinking water source, alternatives should be
configured that would achieve ARARs or risk-based levels as rapidly as
possible.
The NCP proposed rule states that a limited number of remedial alternatives
utilizing one or more technologies that attain site-specific remediation
levels within different time frames should be developed. Also, the no-action
alternative should.be developed. If there is reason to believe that innova-
tive technologies may provide superior performance compared to demonstrated
technologies, these should also be developed. No innovative technologies are
known to exist for which an alternative should be developed for the Salinas
site.
3.5.2 Developed Alternatives
For the site-specific remedial action alternatives developed in this FS/RAP,
we propose that the site manager continue to apply the criteria listed in
Section 3.5 to optimize the aquifer restoration. The screened alternatives
from this FS/RAP are discussed in detail in Section 4.0. The following
paragraphs outline the alternatives.
Alternative A is the no action alternative. This alternative is required by
regulatory guidelines and is considered as a baseline alternative. This
alternative consists of discontinuing the current extraction and treatment.
The monitoring wells would continue to be monitored until 2 years after the
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ground-water cleanup levels are achieved by natural dilution, degradation, and
diffusion.
Alternative B consists of continuing to extract and treat ground water from
the shallow aquifer. No extraction will be done in the intermediate aquifer.
The pumping will stop when the shallow aquifer extraction wells show concen-
trations have remained below the ground-water cleanup levels. Treatment will
consist of combined air stripping and carbon adsorption when the flowrate is
over 180 gpm and air stripping only when the flowrate is less than 180 gpm.
In each of these cases, the effluent is discharged into the Salinas River.
Monitoring will continue in the shallow and intermediate aquifers until the
concentrations have remained below the ground-water cleanup levels for two
uninterrupted years.
Alternative C consists of continuing to extract and treat ground water from
the shallow aquifer and simultaneously pumping and treating ground water from
the intermediate aquifer. Each well in this alternative.will be pumped at its
maximum capacity. This will result in a combined flowrate that exceeds the
current treatment plant capacity of 650 gpm. Thus, a new 500 gpm air stripper
will be installed. Extraction will continue in each well at the maximum
flowrate until the ground-water cleanup levels are achieved in both the
shallow and intermediate aquifers. Treatment will consist of combined carbon
adsorption and air stripping with the existing air stripper as well as with a
new air stripper. The effluent will be discharged into the Salinas River.
Monitoring will continue in the shallow and intermediate aquifers until the
concentrations have remained below the ground-water cleanup levels for two
uninterrupted years.
.Alternative D consists of continuing to extract and treat ground water from
the shallow aquifer and simultaneously pumping and treating ground water from
the intermediate aquifer, as in Alternative C. However, for Alternative D,
all the wells will not be pumped at their maximum flowrate. Rather, the
combined flowrate will be maintained at or below the capacity of the existing
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treatment plant of 650 gpm. Thus, no modification of the treatment plant will
be needed.
Extraction will continue until the ground-water cleanup levels are achieved in
both the shallow and intermediate aquifers. Treatment will consist of com-
bined carbon adsorption and air stripping with the existing treatment plant.
The effluent will be discharged into the Salinas River. Monitoring _wi 11
continue in the shallow and intermediate aquifers until the concentrations
have remained below the ground-water cleanup level for two uninterrupted
years.
Alternative E consists of continuing to extract and treat ground water from
the shallow aquifer and simultaneously pumping and treating ground water from
the intermediate aquifer, like Alternatives C and D. However, only two new
extraction wells will be installed in the intermediate aquifer. This will
result in a combined flowrate of less than the current treatment plant
capacity of 650 gpm. Extraction will continue in each well at the maximum
flowrate until the ground water cleanup levels are achieved. Treatment will
consist of combined carbon adsorption and air stripping with the existing air
stripper as long as the flowrate exceeds 180 gpm. At flowrates below 180 gpm,
only the airstripper will be used. The effluent will be discharged into the
Salinas River. Monitoring will continue in the shallow and intermediate
aquifers until the concentrations have remained below the ground-water cleanup
levels for two uninterrupted years.
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4.0 DETAILED ANALYSIS OF REMEDIATION ALTERNATIVES
This section presents a detailed analysis of the alternatives assembled and
described in Section 3.0, Developing Remediation Alternatives. These alterna-
tives are analyzed for their effect on the mitigation of chemicals in the
ground water. The scope of treatment alternatives for this FS is limited to
the use of air stripping and carbon filters based on the treatment screening
presented in Section 2.0. The various pumping alternatives developed in
Section 2.0 have been combined with treatment alternatives to develop a
limited number of remediation alternatives for aquifer restoration in
Section 3.0. As a result, the alternatives developed in Section 3.0 are
limited to five based on the initial screening.
The purpose of the detailed analyses of alternatives is to analyze and present
relevant information to allow comparison of alternatives, selection of an
appropriate remedy, and demonstration of satisfaction of the statutory
requirements in the ARARs.
The criteria utilized to evaluate alternatives are presented in Section 4.1.
The current NCR rule states that refinement and specification in detail of
alternatives which remain after the alternative screening steps have been
performed are required as part of the detailed analysis of alternatives. Each
alternative is further developed in Section 4.2. An evaluation and comparison
of alternatives for each criteria are presented in Section 4.3. A summary of
the detailed analyses is presented in Section 4.4.
4.1 DETAILED ALTERNATIVE ANALYSES CRITERIA
The following current and proposed regulations and guidance documents have
been reviewed to determine appropriate criteria to be utilized in performing
the detailed analysis of -alternatives:
• California Department of Health Services, 1986, the California Sits
Mitigation Decision Tree Manual, Toxic Substances Control Division,
Alternative Technology and Policy Development Section, May.
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• EPA, 1982, The National Oil and Hazardous Substances Pollution
Contingency Plan under CERCLA, as amended, 47 FR 31203, July 16.
• EPA, 1985b, "Guidance on Feasibility Studies Under CERCLA,"
EPA/540/G-85/003, June.
• EPA, 1988a, "Draft Guidance for Conducting Remedial Investigations
and Feasibility Studies under CERCLA," OSWER Directive 9335.3-01,
March.
• EPA, 1988c, The National Oil and Hazardous Substances Pollution
Contingency Plan, proposed,.rule, 53 FR 51394, December 21.
The current NCP rule states that the detailed analysis of alternatives shall
include the following components:
• Detailed cost estimation, including operation and maintenance costs,
and distribution of.costs over time
• Evaluation in terms of engineering implementation, reliability, and
constructibility
• An assessment of the extent to which the alternative is expected to
effectively prevent, mitigate, or minimize threats to, and provide
adequate protection of public health and welfare and the environ-
ment. This shall include an evaluation of the extent to which the
alternative attains or exceeds applicable or relevant and appropriate
federal public health and environmental requirements. Where the
analysis determines that federal public health and environmental
requirements are not applicable or relevant and appropriate, the
analysis shall, as appropriate, evaluate the risks of the various
exposure levels projected or remaining after implementation of the
alternative under consideration.
• An analysis of whether recycle/reuse, waste minimization, waste
biodegradation, or destruction or other advanced, innovative, or
alternative technologies is appropriate to reliably minimize present
or future threats to public health or welfare or the environment
• An analysis of any adverse environmental impacts, methods for miti-
gating these impacts, and costs of mitigation.
The DHS Decision Tree states that five criteria are utilized in the detailed
analysis of alternatives. The criteria are technical, institutional, cost,
public health, and environmental impact analysis. The criteria presented in
the Decision Tree were based primarily on two EPA publications available at
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the time. These two documents are "Draft Methodology for Screening and
Evaluation of Remedial Responses" (prepared by JRB Associates, McLean, VA for
EPA Municipal Environmental Research Laboratory, Cincinnati, Ohio; and EPA
Office of Emergency and Remedial Response, Washington, D.C., March 16, 1984)
and "Guidance on Feasibility Studies under CERCLA" (EPA, 19855).
Although the proposed NCP rule revision at 53 FR 51394 has not been promul-
gated and the March 1988 RI/FS guidance document has only been issued as a
draft document, these documents provide information on the current direction
of EPA regulations and guidance. DHS recommended that these recent EPA
guidance and rules be followed preferentially over the California Site
Mitigation Decision Tree Manual when the two documents conflicted (William
Owen DHS, personal communication, March 15, 1989).
The preamble to the proposed NCP rule revision states "the RI/FS process
proposed today incorporates statutory requirements, reflects the program
management principles of the bias for action, streamlining, and site manage-
ment planning, and builds on the engineering and analytical steps established
in the current NCP." The proposed rule includes criteria presented in the DHS
Decision Tree and the current NCP rule in a. revised format based on previous
experience. The proposed rule criteria are utilized for the detailed
evaluation of alternatives for this FS/RAP.
The NCP proposed rule defines nine criteria for alternative evaluation as
follows:
(A) Overall protection of human health and the environment. Alter-
natives shall be assessed as to whether they can adequately protect
human health and the environment from unacceptable risks posed by
hazardous substances, pollutants, or contaminants present at the site by
eliminating, reducing, or controlling exposures to levels established
during development of remediation goals. This is a threshold require-
ment and the primary objective of the remedial program.
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(B) Compliance with ARARs. The alternatives shall be assessed as to
whether they attain applicable or relevant and appropriate requirements
(ARARs) of other Federal and State environmental and public health Taws
or provide grounds for invoking one of the waivers included in the
proposed rule. Compliance with ARARs is a threshold requirement. All
alternatives remaining in the final analysis shall meet ARARs or obtain
ARAR waivers.
(C) Long-term effectiveness and permanence. Alternatives shall be
assessed for the long-term effectiveness and permanence they afford,
along with the degree of certainty that the alternative will prove
successful. Factors that shall be considered, as appropriate, include
the following:
(1) Nature and magnitude of total residual risks in terms of
amounts; potential for exposure of human and environmental
receptors; concentrations of hazardous substances, pollutants,
or contaminants remaining following implementation of a remedial
alternative, considering the persistence, toxicity, mobility,
and propensity to bioaccumulate such hazardous substances and
their constituents
(2) The type, degree, and adequacy of long-term management required
for untreated substances and treatment residuals, including
engineering controls (such as containment technologies),
institutional controls, monitoring and operating, and
maintenance
(3) Long-term reliability of the engineering and institutional
controls, including uncertainties associated with land disposal
of untreated hazardous substances, pollutants, and contaminants,
and treatment residuals
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(4) Potential need for replacement of the remedy, as well as the
continuing need for repairs to maintain the performance of the
remedy.
(D) Reduction of toxicity, mobility, or volume. The degree to which
alternatives employ treatment that reduces toxicity, mobility, or volume
shall be assessed. Alternatives which, at a minimum, address the prin-
cipal threats posed by the site through treatment shall also be identi-
fied. Factors that shall be considered, as appropriate, include the
following:
(1) The treatment processes the alternatives employ and materials
they will treat
(2) The amount of hazardous substances, pollutants, or contaminants
that will be destroyed or treated
(3) The degree of expected reduction in toxicity, mobility, or
volume, including how the principal threat is addressed through
treatment
(4) The degree to which the treatment is irreversible
(5) The residuals that will remain following treatment, considering
the persistence, toxicity, mobility, and propensity to
bioaccumulate such hazardous substances and their constituents.
(E) Short-term effectiveness. The short-term impacts of 'alternatives
shall be assessed considering the following:
(1) Short-term risks, that might be posed to the community during
implementation of an alternative
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(2) Potential impacts on workers during remedial action and the
effectiveness and reliability of protective measures
(3) Potential environmental impacts of the remedial action and the
effectiveness and reliability of mitigative measures during
implementation
(4) Time until protection is achieved.
(F) Implementability. The ease or difficulty of implementing the
alternatives shall be assessed by considering the following types of
factors, as appropriate:
(1) Degree of difficulty or uncertainty associated with construction
and operation of the technology
(2) Expected operational reliability of the technologies the alter-
natives utilize and the ability to undertake additional action,
if required
(3) Ability and time required to obtain any necessary approvals and
permits from other agencies
(4) Availability of necessary equipment and specialists
(5) Available capacity and location of needed treatment, storage,
and disposal services
(6) Timing of the availability of prospective technologies that may
be under consideration.
(G) Cost. The types of costs that shall be assessed include 'the
following:
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(1) Capital costs, including contingency and engineering fees
(2) -Operation and maintenance costs
(3) Net present value of capital and O&M costs.
(H) State and/or support agency acceptance. Assessment of State con-
cerns may not be completed until comments on the RI/FS are received and
may be discussed, to the extent possible, in the proposed plan issued
for public comment. The State concerns that shall be assessed include
the following:
(1) The State's and/or support agency position and key concerns
related to the preferred alternative and other alternatives
(2) State and/or support agency comments on ARARs or the proposed
use of waivers.
(I) Community acceptance. This assessment includes determining which
components of the alternatives interested persons in the community
support, have reservations about, or oppose. This assessment may not be
completed until comments on the proposed plan are received.
The EPA RI/FS guidance document presents these nine criteria and expands on
them. The first two criteria, overall protection of human health and the
environment, and compliance with ARARs, are termed threshold criteria in that
these items are evaluated as to whether, and how, the criteria are met as
opposed to the next five criteria for which they are evaluated on a con-
tinuum. In particular, alternatives that do not protect human health and the
environment, or do not comply with ARARs (or justify a waiver), will not meet
statutory requirements for selection of remedy in the Record of Decision
(ROD). The final two criteria for State (and/or support agency) acceptance
and community acceptance are only preliminarily analyzed in the RI/FS. These
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criteria are formally addressed after the completion of the FS and the formal
public hearing/comment period.
4.2 ALTERNATIVE DESCRIPTION
The five alternatives presented in Section 3.0 are developed and described in
further detail in this section. Table 4-1 presents the alternatives versus
potentially applicable or relevant'and appropriate requirements, and Table 4-2
summarizes the detailed analysis of remediation alternatives. A cost compari-
son of the assembled remediation alternatives is presented in Figure 4-3.
4.2.1 Alternative A
Alternative A is the "No-Action" alternative. This is required by regulation
and is considered as a baseline alternative. The "no-action" alternative is
•
defined as being the current site conditions, absent the ongoing remedial
measures. The ongoing remedial measures that started in February 1986 consist
of pumping and treating the ground water with carbon adsorption and air
stripping, and discharging the treated water to the Salinas River under an
NPDES permit.
This alternative consists of stopping the pumping and treating that Is taking
place now. Monitoring will continue under this alternative until the chemical
concentrations in each of the wells decrease to below the ground-water cleanup
levels. Then, monitoring will continue for an additional two years to assure
that no concentrations above the cleanup levels occur (see Section 5-2).
However, this alternative does include maintaining the treatment plant in a
standby mode for two years, ready to be placed back in service if necessary.
After two uninterrupted years with no concentrations above the cleanup levels,
all or portions of the treatment plant may be dismantled and s.alvaged. At
this point, some of the monitoring and extraction wells may be abandoned
according to state and local requirements. Sufficient wells will be retained
to provide data for the 5-year review required by CERCLA Section 121(c).
For this alternative, the treatment plant will not be operated.
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This discussion of Alternative A is not meant to imply that no-action will
clean up the aquifer, rather that after some time, the observed concentrations
of chemicals in the aquifer will decrease to below the ground-water cleanup
levels due to natural attenuation, degradation, and diffusion.
Computer simulations have been made for Alternative A. The program used for
these simulations and the input parameters are discussed in Appendix J. The
model areas are shown in Figure 4-1. The migration of the chemical plume for
Alternative A, as depicted by the cleanup concentration line is shown in
Figure 4-1A for the shallow aquifer and in Figure 4-18 for the intermediate
aquifer. Under this alternative, with no additional pumping, the plume
migrates toward the west-in the shallow aquifer and toward tne west-northwest
in the intermediate aquifer. Figures 4-1A and 4-1B were prepared assuming a
hydraulic conductivity of 200 feet/day. The rate of plume migration is
directly proportional to the hydraulic conductivity. Thus, if the hydraulic
conductivity were 100 ft/day instead of the 200 ft/day used, the plume would
migrate half as fast. For a conservative cost estimate, the time required to
reach the cleanup level was taken consistent with a hydraulic conductivity of
100 ft/day rather than 200 ft/day.
As the plume reaches the left side of the model in Figure 4-1A, the snallpw
aquifer merges with the intermediate aquifer as discussed in the RI. Thus,
when the plume reaches the left side of the model, the shallow aquifer has
reached .the cleanup level. This takes . 5 years as shown in Figure 4-1.-.
However, for a conservative cost estimate, we assumed a 10-year monitoring
period for this alternative because the hydraulic conductivity could easily
vary by a factor of 2.
i
The net present worth of the-cost for implementing Alternative A is $1,525,0.00
at a discount rate of 3 percent, $1,387,000 at 5 percent, and SI,116,000 at
10 percent, as summarized in Table 4-3. The cost summary for Alternative A is
presented in Table 4-4. There are no capital costs for this alternative
because no additional pumping or treating is involved. Monitoring and
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reporting costs have been included at $14,QOO/month for 120 months. A period
of 120 months was used for comparison purposes. As discussed earlier the com-
puter simulations indicate the cleanup period is directly proportional to the
hydraulic conductivity. The cleanup period is projected at 60 to 120
months. This analysis includes a cost of $4,000/month for 24 months for main-
taining the existing treatment plant in an operational mode in the event that
the concentrations of chemicals in the ground water increase and it is decided
to restart the plant. No salvage value for the treatment plant is included in
the analysis.
4.2.2 . Alternative B
Alternative B consists of a continuation of the existing pumping and treating
of ground water from the shallow aquifer only, on- and off-site. Currently,
there are 15 on-site extraction wells and 5 off-site extraction wells in the
shallow aquifer. The site manager adjusts the flowrate from each of these
extraction wells to accommodate changes in the concentrations indicated.by the
monitoring data. This pumping and treating will continue until the monitoring
data indicate that the chemical concentrations in the ground water in the
shallow aquifer are less than the ground-water cleanup levels.
This alternative includes maintaining the treatment plant in a standby mode
for two years, ready to be placed back in service ,if necessary. After two
uninterrupted years with no concentrations above the cleanup levels (see
Section 5-2), all or portions of the treatment plant may be dismantled ana
salvaged. At this point, some of the monitoring and extraction wells may be
abandoned according to state and local requirements. Monitoring will continue
in the 120-foot aquifer until two years after the chemical concentrations
reach the ground-water cleanup levels. Then, the 120-foot aquifer, monitoring
wells may be abandoned. At this point, the remedial action will be com-
plete. Sufficient wells will be retained to provide data for the 5-year
review required by CERCLA Section 121(c).
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For this alternative, the treatment plant will continue to operate with both
the air stripper and the carbon beds as it is presently operating.
Computer simulations have been made for Alternative B, similar to Alternative
A. The areas of the shallow and intermediate aquifers with concentrations
above the cleanup levels in this alternative are depicted in Figure 4-2A and
B. In contrast to Alternative A, Figure 4-2A shows that the extraction wells
arrest the westward flow of the plume in the shallow aquifer. In fact, this
figure shows the cleanup level contour closing around both the on-site and the
offsite extraction well fields. Figure 4-2A shows that Alternative B cleans
up the shallow aquifer in 2 years as opposed to 5 years for Alternative A (for
a hydraulic conductivity of 200 ft/yr) as shown in Figure 4-1A. -Thus, Alter-
native B is expected to achieve the cleanup levels in the shallow aquifer in
about 40% of the time required by Alternative A.
The cleanup in the intermediate aquifer proceeds at the same rate for both
Alternative A and Alternative B because there is no pumping from this aquifer
in either alternatives. The effect of reducing the mass loading into the
intermediate aquifer compared to Alternative A is small.
The net present worth of the cost for implementing Alternative B is $3,186,000
at a discount rate of 3 percent, $2,990,000 at 5 percent, and $2,588,000 at
10 percent, as summarized in Table 4-3. The cost summary for Alternative 3 is
presented in Table 4-5. There are no additional capital costs for this alter-
native because no additional pumping or treating capacity is involved. For
purposes of this cost comparison, monitoring and reporting costs have been
included at $18,000/month for 33 months (while the treatment plant was assumed
to be operating) and $14,000/month for 120 months. A period of 120 months was
used for comparison purposes. As discussed earlier the computer simulations
indicate the cleanup period is directly proportional to the hydraulic
conductivity. The cleanup period is projected at 60 to 120 .months. This
analysis includes a cost of $35,200/month for 33 months for operating the
existing treatment plant. No salvage value for the treatment plant is
included in the analysis.
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It is recognized that the results of computer models have limitations, and
therefore, the best available predictions of ability and time to meet ARARs
may not be accurate. Therefore, this remedial alternative would include
evaluation, of system operations and effectiveness on a semi-annual basis,
based on monitoring data. In the event remedial goals cannot be achieved, the
RAP/ROD may be amended accordingly by invoking.the appropriate ARAR waiver.
Any such RAP/ROD amendment would include appropriate public participation.
4.2.3 Alternative C
Alternative C was defined to pump and treat the affected ground water in the
120-foot aquifer as well as the ground water in the shallow aquifer. This
alternative.consists of installing and developing five new extraction-wells in
the .120-foot aquifer and starting to pump and treat ground water from this
aquifer concurrently with the pumping from the shallow aquifer.
For Alternative C, the pumping and treating of ground water from the 20 exist-
ing extraction wells in the shallow aquifer wilj continue. The site manager
will adjust the flow from each well based on the monitoring data. After the
concentrations in the shallow aquifer decline to the ground-water cleanup
levels, pumping from the shallow aquifer will be stopped, but monitoring in
the shallow aquifer will continue for an additional two years.
In addition to this shallow aquifer remediation, Alternative C includes pump-
ing and treating ground water from the 120-foot aquifer. The five new extrac-
tion wells in the 120-foot aquifer will be located in a line along the axis of
the chemical plume. The actual locations will vary somewhat depending on the
time that the wells are installed because the plume is continuing to migrate
toward the northwest. Thus, the longer it takes to obtain the access permits
and agency approvals and the longer the installation may be delayed due to
planting cycles or weather, the farther to the northwest is the optimum loca-
tion of the new extraction wells.
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Final Revision
The pumping and treating of ground water from the 120-foot aquifer will be
started as soon as the new wells can be installed and developed. The flow-
rates from both the 120-foot and the shallow aquifer will be adjusted by the
site manager based on the monitoring data. For Alternative C, the combined
flowrate will exceed 650 gpm, and the minimum flowrate from the new wells in
the intermediate wells will be 400 gpm. Thus, the treatment plant will
require modification and, because the flowrate exceeds 1,000 gpm, the NPDES
permit will have to be modified. (For the purposes of this report, it has
been assumed that a new air stripper with a capacity of 500 gpm will be
installed, based on a comparison of costs with a new carbon adsorption
system). This pumping and treating of ground water from the 120-foot aquifer
will continue until the concentrations are below the ground-water cleanua
levels.
Monitoring in all aquifers will continue for two years after this to assure
that no concentrations above the cleanup levels occur. This alternative
includes maintaining the treatment plant in a standby mode for two years,
ready to be placed back in service if necessary. After two uninterrupted
years with no concentrations above the cleanup levels (see Section 5-2), all
or portions of the treatment plant may be dismantled and salvaged. At this
point, some of the monitoring and extraction wells may be abandoned according
to state and local requirements. Sufficient wells will be.retained to provide
data for the 5-year review required by CERCLA Section 121(c).
Results of the computer simulations for Alternative C are presented in Figures
4-3A and B for the shallow and intermediate aquifers, respectively. The
cleanup in the shallow aquifer for Alternative C proceeds as it did for
Alternative B, (Figure 4-2A) because the pumping is the same. However, as can
be seen in Figure 4-3A, continuing pumping from both the onsite and offsite
shallow aquifer wells results in developing a null point between the two
extraction well fields where the gradient is relatively small. As shown in
Figure 4-3A, the shallow aquifer is cleaned up in 2 years.
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The cleanup of the intermediate aquifer is depicted in Figure 4-3B. This
shows that cleanup is achieved in 1 1/2 years.
The net present worth of the cost for implementing Alternative C is $5,905,000
at a discount rate of 3 percent, $5,722,000 at 5 percent,., and $5,308,000 at
10 percent, as summarized in Table 4-3. The cost summary for Alternative C is
presented in Table 4-6. The capital costs for this alternative include the
cost for a new air stripper and the cost for installing five new extraction
wells and a new segment of pipeline. Monitoring and reporting costs have been
included at $18,000/month for 33 months. This analysis includes a cost of
$4,000/month for 24 months for maintaining the existing treatment plant in an
operational mode in the event that the concentrations of chemicals in the
ground water increase and it is decided to restart the plant beyond the
planned operational period. No salvage value for the treatment plant is
included in the analysis.
A primary objective of this remedial effort will be to establish a zone of
capture for chemicals above the cleanup levels in the intermediate aquifer.
Accordingly, once the new extraction wells are installed, they will be sampled
for contaminants to determine the concentrations at the wells. If necessary,
one or more additional wells will be installed farther downgradient and/or
pumping rates adjusted to ensure that the capture zone intercepts any portion
of the plume with contaminant concentrations above the cleanup level for any
contaminant.
Once pumping has commenced, aquifer tests will be performed to verify the zone
of capture for the wells. If necessary, another well may be installed furrhe-
downgradient.and pumping rates adjusted accordingly so that any portion of the
plume containing concentrations above the cleanup Iev2ls for any contamination
is intercepted.
It is recognized that the results of computer models have limitations, and
therefore, the best available predictions of ability and time to meet ARARs
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Final Revision
may not be accurate. Therefore, this remedial alternative would include
evaluation of system operations and effectiveness on a semi-annual basis,
based on monitoring data. In the event remedial goals cannot be achieved, the
RAP/ROD may be amended accordingly by invoking the appropriate ARAR waiver.
Any such RAP/ROD amendment would include appropriate public participation.
4.2.4 Alternative D
Alternative D, like Alternative C, was defined to pump and treat the affected
ground water in the 120-foot aquifer as well as the ground water in the shal-
low aquifer. This alternative consists of installing and developing five new
extraction wells in the 120-foot aquifer and pumping and treating ground water
from this aquifer concurrently with the pumping from the shallow aquifer. The
minimum flowrate from the new wells installed in the intermediate aquifer is
400 gpm. Capture zone analyses were done for Alternative D for both the
shallow and intermediate aquifers because this is the recommended alternative.
4.2.4.1 Zone of Capture, Shallow Aquifer
For Alternative D, the pumping and treating of ground water from some of the
20 existing extraction wells in the shallow aquifer will continue. The
purpose of determining the zone of capture is to provide information support-
ing the development of a feasible and practical plan for remediation of the
ground water in the shallow aquifer. Additionally, the analysis must show
that the scenario is feasible, timely, cost effective, and technically
acceptable. One of the standard methods for determining the zone of capture
is to use the Theis non-equilibrium, equation developed in 1935 and determine
the drawdown or that portion of the aquifer dewatered resulting from the
pumping of wells. There are many methods for determining the drawdown In
wells, and they range from mathematical calculations plotted on graph paper to
plots on graphs developed for this purpose.
Since pumping has been going on for several years in the shallow aquifer and a
shrinking of the plume has been shown in the field-collected data, no calcula-
tions are performed for the shallow aquifer. A comparison of the plume s-izs
to the measured potentiometric levels will be used for this analysis.
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Final Revision
The following pumping rates apply to the wells pumping from the shallow
aquifer for this analysis:
On-site Wells
well IT-S7 - 70 gpm
Well IT-S8 - 10 gpm
Well IT-SI1 - 25 gpm
Well IT-MI - 155 gpm
Total - 260 gpm
Off-site Wells
Well IT-SE2 - 70 gpm
Well IT-SE3 - 35 gpm
Well IT-SE4 - 70 gpm
Well IT-SE5 - 60 gpm
Total - 235 gpm
These pumping rates will be reduced when the five new intermediate aquifer
extraction wells are installed and become operational. The combined flowrate
will not exceed 650 gpm.
The 4 wells located on site are located more or less in a northeast-southwest
line along the property line of the facility. The off-site wells are located
in an "L" shape in an area approximately 800 feet west of the facility (Figure
3-12). The configuration of wells on-site appears to be the optimum arrange-
ment for the interception of any contaminant migrating from the facility. The
configuration of the off-site wells is an attempt to intercept and also
compress the plume as it moved from the facility.
Figure 4-4 shows the capture zone for the shallow aquifer. A comparison cf
the January 1988 and 1989 contours indicates that the drawdown from the
shallow wells is adequate to intercept the plume. The plume has decreased the
size and concentration levels 'in a reasonable time frame and it appears that
the wells will continue to intercept the plume for the duration of their
pumping.
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Final Revision
The site manager will adjust the flow from each well based on the monitoring
data. After the concentrations in the shallow aquifer decline to the ground-
water cleanup levels, monitoring in the shallow aquifer will continue for an
additional two years. Monitoring will continue under this alternative until
the chemical concentrations in each of the wells decrease to below the ground-
water cleanup levels. Then, monitoring will continue for an additional two
years to assure that no unusual increases in the concentrations above the
cleanup levels occur (see Section 5.2).
4.2.4.2 Zone of Capture, Intermediate Aquifer
In addition to this shallow aquifer remediation, Alternative D includes pump-
ing and treating ground water from the 120-foot (intermediate) aquifer. The
purpose of determining the zone of capture is to provide information support-
ing the development of a feasible and practical plan for remediation of the
ground water in the 120-foot aquifer. Additionally, the calculations must
show that the scenario is feasible, timely, cost effective, and technically
acceptable. One of the standard methods for determining the zone of capture
is to use the Theis non-equilibrium equation developed in 1935 and determine
the drawdown or that portion of the aquifer dewatered resulting from the
pumping of wells. There are many methods for determining the drawdown in
wells and they range from mathematical calculations plotted on graph paper to
plots on graphs developed for this purpose. The method to be used in this
section will be a computer generated result and is described as follows.
The zone of capture is defined using the Prickett solution of the Theis non-
equilibrium equation (Figure 4-5A). The program RESSQ was used to calculate
flow patterns (Figures 4-5B and C). Appendix J of this report explains these
models, the effectiveness, the limitations, and the assumptions required for
their operation.
The following constants were used to determine drawdown.
Transmissivity - 74,800 gpd/ft or 10,000 ft2/d
Storage Coefficient - 0.001
Pumping Rate - 650 gpm for Figures 4-5A and B
- 400 gpm for Figure 4-5C
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Final Revision
The 5 wells are located in a line as shown in Figure 3-12, with wells IT-IE2
through 5 separated by about 300 feet and wells IT-IE1 and 2 separated by
about 880 feet. This configuration of wells is the optimum arrangement as
demonstrated in this document.
Figure 4-5A shows the capture-zone for the 120-foot aquifer. Note that after
30 days of pumping the cone of depression (zone of capture) reaches beyond the
January 1989 target cleanup area. This indicates that the drawdown is ade-
quate to intercept the plume within a reasonable time frame and will continue
to intercept the plume for the duration of the pumping.
The five new extraction wells in the 120-foot aquifer will have a- minimum
pumping rate of 400 gpm and will be located in a line along the axis of the
chemical plume. The actual locations will vary somewhat depending on the time
that the wells are installed because the plume is continuing to migrate toward
the northwest. Thus., as in Alternative C, the longer it takes to obtain
access permits and agency approvals and the longer the installation may be
delayed due to planting cycles or weather, the farther to the northwest is the
optimum location of the new extraction wells.
The pumping and treating of ground water from the the 120-foot aquifer will be
started as soon as the new wells can be installed, and developed. The flow-
rates from both the shallow aquifer and the 120-foot aquifer extraction wells
will be adjusted by the site manager based on the monitoring data. However,
the combined flowrate will be less than 650 gpm so the treatment plant will
not require modification and new operating permits are not required. This
pumping and treating of ground water from the 120-foot aquifer will continue
until the chemical concentrations are below the ground-water cleanup levels.
Then, pumping will be stopped, but monitoring in the 120-foot aquifer will
continue for an additional two years. At this point, some of the monitoring
and extraction wells may be abandoned according to state and local require-
.ments. Sufficient wells will be retained to provide data for the 5-year
review required by CERCLA section 121(c).
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4.2.4.3 Computer Simulations
Results of the computer simulations for Alternative D are presented in Figures
4-6A and B for the shallow and intermediate aquifers, respectively. The
pumping scenario described below is for modeling purposes only. For actual
conditions, pumping rates will be based on the monitoring well design, and the
results of aquifer testing and monitoring. Both shallow and intermediate
aquifer wells can be pumped at the same time. However, the pumping rates for
all intermediate aquifer wells combined will be a minimum of 400 gpm. The
cleanup in the.shallow aquifer proceeds as shown in Figure 4-6A. This figure
shows that the plume migration in the shallow aquifer is initially arrested by
.the current pumping. To break the null point discussed in Alternative C, the
on-site, shallow aquifer pumping has been simulated as being terminated in
August 1989. Off-site, shallow aquifer pumping is continued at 200 gpm until
October 1989 for this simulation. This allows the remaining shallow aquifer
plume to migrate under the regional gradient toward the merging of the shallow
and intermediate aquifers. Figure 4-6A shows that by February 1991 only an
area about 800 feet long is covered with the target cleanup plume, and by
February 1992 the shallow aquifer is practically all below the cleanup levels.
The cleanup of the intermediate aquifer is depicted in Figure 4-6B. This
shows that cleanup is achieved under this simulation in 1 1/2 years. This
alternative.also avoids developing a null point between the shallow and inter-
mediate aquifers by terminating the shallow aquifer pumping earlier than the
intermediate aquifer pumping.
Two additional variations of Alternative D have been simulated. These are
labeled as Alternative D' (650 gpm) and Alternative 0' (400 gpm). The pur-
poses of these additional simulations were to assess the effect of a delay in
beginning pumping from the intermediate aquifer and the effect of pumping at a
flowrate of only 400 gpm.
As discussed in Section 3, if there are delays in obtaining access agreements
or agency approvals, it may not be possible to install the new extraction
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Final Revision
wells and new pipeline segment by the fall of 1989. . If this occurs, the
installation will have to be delayed until the spring of 1989 because the
drill rigs and construction equipment may not be allowed to damage the fields
and roads during the winter rainy season. Thus, a simulation was made with
the-intermediate aquifer pumping starting in April 1990. The results of this
simulation (Figure 4-6C) show that the proposed well locations are not as
effective as they are if the pumping is started in the fall of 1989. The
we,lIs should be relocated farther to the west, as discussed in Section 3.
The fourth simulation used the fall of 1989 as the start date of pumping from
the intermediate aquifer. However, in contrast to the simulation depicted in
Figure 4-6B where the pumping rate was 650 gpm, the pumping rate used for the
simulation was only 400 gpm. The results of this simulation are summarized in
Figure 4-6D. This* figure shows that a pumping rate of 400 gpm is only
minimally effective in containing the intermediate aquifer plume. Thus, for
the recommended alternative a minimum pumping rate of 400 gpm is specified.
4.2.4.4 Summary of Costs
The net present worth of the cost for implementing Alternative D is $1,829,000
at a discount rate of 3 percent, $1,792,000 at 5 percent, and $1,708,000 at
10 percent, as summarized in Table 4-3. The cost summary for Alternative 0 is
presented in Table 4-7. Capital costs for this alternative include the costs
for installing the five new wells and a new segment of pipeline; there are no
new capital costs for the treatment plant. Monitoring and reporting costs
have been included at $18,000/month for 12 months and at $14,000/month for 24
months. This analysis includes a cost of $4,000/month for 24 months for main-
taining the existing treatment plant in an operational mode in the event that
the concentrations of chemicals in the ground water increase and it is decided
to restart the plant. No salvage value for the treatment plant is included in
the analysis.
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Final Revision
4.2.4.5 Remedial Action Goals
A primary objective of this remedial effort will 'be to establish a zone of
capture for chemicals above the cleanup levels in the intermediate aquifer.
Accordingly, once the new extraction wells are installed, they will be sampled
for contaminants to determine the concentrations at the wells. If necessary,
one or more additional wells will be installed further downgradient and/or
pumping rates adjusted to ensure that the capture zone intercepts any portion
of the plume with contaminant concentrations above the cleanup level for any
contaminant.
Once pumping has commenced, aquifer tests will be performed to verify the true
zone of capture for the wells. If necessary, another well may be installed
further downgradient and pumping rates adjusted accordingly so that any
portion of the plume containing concentrations above the cleanup levels for
any contamination is intercepted.
It is recognized that the results of computer models have limitations, and
therefore, the best available predictions of ability and time to meet ARARs
may not be accurate. Therefore, this remedial alternative would include
evaluation of system operations and effectiveness on a semi-annual basis,
based on monitoring data. In the event remedial goals cannot be achieved, the
RAP/ROD may be amended accordingly by invoking .the appropriate ARAR waiver.
Any such RAP/ROD amendment would include appropriate public participation.
4.2.5 Alternative E
Alternative E, like Alternatives C and D, was defined to pump and treat the
affected ground water in the 120-foot aquifer as well as the ground water in
the shallow aquifer. This alternative consists of installing and developing
two new extraction wells in the 120-foot aquifer and pumping and treating
ground water from this aquifer concurrently with pumping from the shallow
aquifer.
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Final Revision
For Alternative E, the pumping and treating of ground water from some of the
20 existing extraction wells in the shallow aquifer will continue. The site
manager will adjust the flow from each well based on the monitoring data.
After the chemical concentrations in the shallow aquifer decline to the
ground-water cleanup levels, monitoring in the shallow aquifer will continue
for an additional two years.
In addition to this shallow remediation, Alternative E includes pumping and
treating ground water from the 120-foot aquifer. The two new extraction wells
in the 120-foot aquifer will be located in a line along the axis of the chemi-
cal plume. The actual locations will vary somewhat depending on the time that
the wells are installed because the plume is continuing to migrate toward the
northwest. Thus, the longer it takes to obtain access permits and agency
approvals, and the longer the installation may be delayed due to planting
cycles or weather, the farther to the northwest is the optimum location of the
new extraction wells.
The pumping and treating of ground water from the 120-foot aquifer will be
started as soon as the new wells can be installed and developed. The flow-
rates from both the shallow aquifer and the 120-foot aquifer extraction wells
will be adjusted by the site manager based on the monitoring data. However,
the combined flowrate will be less than 650 gpm, and the treatment plant will
not require modification. This pumping and treating of ground water from the
120-foot aquifer will continue until the chemical concentrations are below the
ground-water cleanup levels. Then pumping will be stopped and monitoring in
the 120-foot aquifer will continue for an additional two years. If no
concentrations above the cleanup levels occur (see Section 5-2), some of the
monitoring and extraction wells in the 120-foot aquifer may be abandoned, and
the treatment plant may be disassembled and salvaged. Sufficient wells will
be retained to provide data for the 5-year review required by CERCLA Section
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Results of the computer .simulations for Alternative E are presented in Figures
4-7A and B for the shallow and intermediate aquifers, respectively. The
cleanup in the shallow aquifer proceeds as shown in Figure 4-7A. This figure
shows that the plume migration is initially arrested by the current pumping.
To break the null point discussed in Alternative C, the onsite pumping is
terminated in 6 months. Off-site, shallow aquifer pumping is continued at 200
gpm for 9 months. This --allows the remaining plume to migrate under the
regional gradient toward the merging of the shallow and intermediate aquifers.
Figure 4-7A shows that only an area about 1,000 feet long is covered with the
target cleanup plume at that time, and by the Spring of 1992 the shallow
aquifer is practically all below the cleanup level.
The cleanup of the intermediate aquifer is depicted in Figure 4-7B. This
shows that cleanup is achieved in 5 years. This alternative also avoids
developing a null point between the shallow and intermediate aquifers by
terminating the shallow aquifer pumping earlier than the intermediate aquifer
pumping.
The net present worth of the cost for implementing Alternative E is $3,444,000
at a discount rate of 3 percent, $3,311,000 at 5 percent, and $3,017,000 at
10 percent, as summarized in Table 4-3. . The cost summary for Alternative E is
presented in Table 4-8. Capital costs for this alternative include the costs
for installing two new extraction wells and a new segment of pipeline; there
are no capital costs for the treatment plant. Monitoring and reporting costs
have been included at $18,000/month for 36 months and at $14,000/month for
12 months. A period of 120 months was used for comparison purposes. As dis-
cussed earlier the computer simulations indicate the cleanup period is
directly proportional to the hydraulic conductivity. The cleanup period is
projected at 60 to 120 months. This analysis includes a cost of $4,000/month
for 24 months for maintaining the existing treatment plant in an operational
mode in the event that the concentrations of chemicals in the ground water
increase and it is decided to restart the plant. No salvage value for the
treatment plant is included in the analysis.
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Final Revision
A primary objective of this remedial effort will be to establish a zone of
capture for chemicals above the cleanup levels in the intermediate aquifer.
Accordingly, once the new extraction wells are installed, they will be sampled
for contaminants to determine the concentrations at the wells. If necessary,
one or more additional wells will be installed further downgradient and/or
pumping rates adjusted to ensure that the capture zone intercepts any portion
of the plume with contaminant concentrations above the cleanup level for any
contaminant.
Once pumping has commenced, aquifer tests will be performed to verify the zone
of capture for the wells. If necessary, another well may be installed further
downgradient and pumping rates adjusted accordingly so that any portion of the
plume containing concentrations above the cleanup levels for any contamination
is intercepted.
It is recognized that the results of computer models have limitations, and
therefore, the best available predictions of ability and time to meet ARARs
may not be accurate. Therefore, this remedial alternative would include
evaluation of system operations and effectiveness on a semi-annual basis,
based on monitoring data. In the event remedial goals cannot be achieved, the
RAP/ROD may be amended accordingly by invoking the appropriate ARAR waiver.
Any such RAP/ROD amendment would include appropriate public participation.
4.3 DETAILED ANALYSIS
A detailed analysis has been performed on each alternative using the
previously presented evaluation criteria. The primary remediation goal is the
control of the migration and removal of contaminants in the ground water
resulting from the operation of the Firestone facility in .the Salinas Valley,
California. This wiTi be accomplished by determining the best pumping alter-
native that will provide the highest level of contaminants for treatment at
the most cost-effective level.
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Final Revision
This analysis includes an evaluation of each alternative by criteria and a
comparison of the relative performance among alternatives. The effectiveness
of the alternatives in meeting contaminant-specific, location-specific, and
action-specific ARARs are discussed separately. The detailed analysis
presented in this section is not intended to be cqmplete and final, but is
intended to present sufficient information about each alternative to allow a
comparative evaluation.
«
4.3.1 Short-Term Effectiveness
The primary remedial response objective to be achieved by the remedial action
is attainment of ground water quality at the cleanup levels for chemicals in
the site ground water. Alternatives C and D would most likely achieve these
objectives the earliest. There is only a marginal difference in time between
the two alternatives. Alternative C and .Alternate D well field layout in the
intermediate aquifer appears to be well suited to the site geology. The
limited number of wells installed under Alternative E may not provide an
efficient field for capture of chemicals. Additionally, full utilization of
the existing treatment plant after the shallow zone is fully remediated may
not be achievable, pumping from only two wells in the intermediate zone,
during the later stages of Alternative E. In any event, the time required to
remediate under Alternative E would exceed that required for Alternatives C
and D.
Alternative B does not provide active remediation of the intermediate zone.
Alternative A provides no further active remediation. Implementation of
either of these alternatives could contaminate downgradient aquifers.
Remediation of the intermediate zone (Alternatives C, 0, and E) is expected to
remove contaminated ground water significantly and reduce the potential of
significant contamination of the deeper aquifers.
The risk to the community is highest under the No-Action Alternative A. The
potential for contaminant exposure is highest, if. contaminants are allowed to
migrate to the deeper aquifers. Passive remediation utilizing natural
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Final Revision
attenuation mechanisms and agricultural well use allows a greater potential
for further contamination of wells. Alternative C may result in atmospheric
discharges of contaminants from the new air stripper at levels approaching the
current discharge criteria (potentially limiting operation or requiring
further monitoring). Alternatives 8, D, and E present the lowest risk to the
•
community during remediation. Incremental differences between these alterna-
tives may not be significant.
The risk to workers, although still small, will be greatest under
Alternative C. Construction-related risk varies with level of improvements.
Alternative C includes constructing a new air stripper and five new wells,
Alternative 0 includes five new wells, Alternative E includes two new wells
only. The increase in emissions under Alternative C would lead to an
increased hypothetical risk to the worst-case worker exposure scenario.
Alternatives A, B, and E have the lowest potential for worker risk.
Short-term environmental impacts are greatest under Alternative A followed by
Alternative B due to the potential for further migration of the contaminant
plume. The high flowrate of ground water withdrawal under Alternative C may
have a minor impact on ground water recharge and lead to entrainment of rela-
tively noncontaminated ground water. Alternatives D and E will have the least
impacts on the environment during construction and implementation 'of the
remedial alternative. Environmental disturbances due to construction activi-
ties under Alternatives C, D, and E correspond with their respective levels of
construction.
Summary of Short-Term Effectiveness
Based on the above discussions, the alternatives with intermediate aquifer
extraction are rated approximately equal. Alternative B is less short-term
effective due primarily to lack of intermediate zone treatment, and Alterna-
tive A is least short-term effective due to total reliance on passive remedia-
tion techniques.
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Final Revision
4.3.2 Long-Term Effectiveness and Permanence
The magnitude of residual risk is highest for Alternative A due to the higher
potential for contamination of domestic and agricultural wells from reliance
on natural mechanisms for remediation of the shallow and intermediate zones.
Shallow aquifer active remediation under Alternative B produces long-term
residual risk less than Alternative A, but greater than Alternatives C, D, and
E. Alternatives C, D, and E all remediate the intermediate zone, although
Alternatives C and D are most likely to remove more contaminants than
Alternative E due to capture efficiency of the larger well field.
Monitoring and relying on natural mechanisms for remediation of shallow and
intermediate zone aquifers in Alternative A and the intermediate zone aquifers
in Alternative B are deemed marginal to control further spread of contamina-
tion. Long-term monitoring and maintenance of plant for restart would be
required. Contamination could spread to a point where remediation was no
longer feasible. Installing a new air stripper as presented in Alternative C
could require significant downtime to allow for construction and debugging.
The existing system has been proven and is currently operating smoothly and
reliably. Alternatives D and E are the most reliable alternatives.
The plume maps for the deep aquifer (Figures 3.7 and 3.8) show that the plume
is lenticular in shape and, although 26 deep aquifer monitoring wells were
installed, only a limited number .of these wells detected any chemicals. A
model simulation of the deep aquifer was studied to assess the effectiveness
of pumping from the agricultural wells in remediating the deep aquifer. The
results indicate that the agricultural wells strongly influence the direction
of ground-water flow and additional extraction wells would have difficulty
matching the withdrawal rate and influence. Therefore, data from the Harden
12 AG well was used to determine the trends of concentrations of chemicals in
the deep aquifer. Figure 4.8 shows the downward trend of 1,1-DCE in the
Harden 12 AG well over the past 3 years. Although two deep aquifer monitoring
wells, ITM17A and ITM13A, have 1,1-OCE levels above drinking water standards,
a downward trend is expected, similar to the Harden 12 AG well. Because
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Final Revision
agricultural use of the water has generally decreased the concentrations to a
relatively low level of chemicals in the aquifer or has prevented large
increases of concentrations of chemicals, and, this can be expected to
continue in the future, no alternatives requiring additional extraction wells
are planned for the deep zone.
Summary of Lonq-Term Effectiveness and Permanence
Based on the potential inadequacy of natural mechanisms .to fully or partially
remediate shallow or intermediate aquifers as required for implementation of
Alternatives A and B, capture efficiencies of various intermediate zone reme-
.diation alternatives, and proven efficiency of the existing plant, the alter-
natives are ranked from the most to least long-term effective and permanent as
follows: D, C, E, B, A.
4.3.3 Reduction of Toxicity, Mobility, and Volume
Under the No-Action alternative, no active treatment process .is employed.
Treatment processes for all the other alternatives utilize air stripping and
carbon adsorption technology as appropriate treatment processes, as discussed
in Section 2.0. Alternative C would necessitate increased treatment plant
capacity most likely in the form of an additional air stripper. The current
air stripper and carbon adsorption system are flow limited at 130 gpm and
500 gpm, respectively.
The existing combined treatment system meets NPDES and MBUAPCD air pe-mit
requirements. Permit modifications would be required for Alternative C.
Alternative C has the highest potential to treat the greatest amount of ground
water, although the removal efficiencies may suffer due to dilution of contam-
inants by entrainment of noncontaminated ground water. Alternative 0 is
expected to remove only slightly less contaminants than Alternative C, but in
doing so, will extract a much lesser volume of water. Of the intermediate
zone extraction methods, Alternative E will potentially extract the least
amount of contaminants due to the reduction in contaminant capture efficiency
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Final Revision
caused by using only two wells in the intermediate aquifer. Alternative 8
will not address active remediation of contaminants in the intermediate
aquifer. Alternative A will not address active remediation of the shallow or
the intermediate aquifers.
The treatment processes involved are primarily irreversible removal processes
where little destruction takes place directly. Contaminants adsorbed by the
carbon unit are later removed from the carbon by a recycling firm. The spent
carbon may be considered a treatment residual. Volatiles removed from the air
stripper are emitted to the air and may undergo photochemical reactions in the
atmosphere. Alternatives 0 and E would generate more carbon than Alterna-
tive C due to the reliance on the carbon units for a greater percentage of
waste stream treatment and longer treatment period. Similarly, greater local
air emissions would be encountered under Alternative C.
Summary of Reduction of Toxicity. Mobility, and Volume
Alternative C may provide slightly greater removal of contaminants from the
ground water, although local discharges to surface water and air may be
higher. Alternative 0 appears to provide the best match of removal, due to
the fact' that highly contaminated areas will be preferentially treated first.
Capture efficiency may suffer for Alternative I due to too few wells, whereas
Alternatives A and B do not thoroughly address each of the chemical plumes.
4.3.4 Implementabi1ity
4.3.4.1 Technical Feasibility
Alternatives A and B require no new construction, and can be implemented
immediately. Alternatives C, 0, and E require installation of new off-site
extraction wells. In addition, Alternative C would require expansion of the
existing treatment plant. Construction of new off-site wells would require
permits and easements from property owners.
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Final Revision
Installation of new wells would have to be done during the dry season.
Previous experience has shown damage to fields may be caused if drilling is
attempted during wet weather. This restriction may cause some unscheduled
delays.
The least reliable alternative is A. Natural degradation or dilution of the
plume is dependent on many changing factors. Contaminant concentrations
within the,plume may decrease slower than predicted extending the remediation
time even further. The plume during that time may migrate farther into the
aquifers. However, should this trend be observed, counteractive measures such
as resuming ground water extraction could be implemented.
The water-treatment technologies of carbon treatment and air stripping used in
Alternatives B, C, 0, and E are well demonstrated and very efficient. Ground-
water extraction has been demonstrated as an effective way to control the
movement of the contamination plume.
The technologies recommended by the proposed alternatives would be expected to
develop schedule delay as a result of technical failure. However, Alternative
A is the most likely alternative to be slower than expected. Alternatives C
and D would take longer to implement due to new well construction but this
delay is accounted for in the schedule.
None of the alternatives would hinder or prevent the taking of additional
remedial action. The only delays that may be incurred are obtaining any
required permits and the time to implement additional strategies.
Under interim remediation status, numerous monitoring wells.were installed at
the site and existing water wells identified near the vicinity. The site
geology is complex. However, it is not anticipated that any of the alterna-
tives, if implemented, would require additional monitoring wells to be
installed. There are monitoring wells between the contamination plume and
existing downgradient drinking water wells.
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Final Revision
Summary of Implementability
Alternatives C and D are most likely to be technically successful and meet
predicted schedule dates. Alternative A is least likely to decrease contami-
nation levels to desired levels by the scheduled dates.
4.3.4.2 Administrative Feasibility
Currently, the air permit for the air stripper limits flow to 180 gpm and
various contaminant-specific emissions. It is anticipated that flowrates may
be modified, if a new air stripper were installed, but total facility emission
increases would not be allowed to increase. Increases in emission upon
installation of an air stripper per Alternative C may approach or exceed
emission standards or the 75 percent threshold requiring additional moni-
toring.
The NPOES permit currently limits discharges to the Salinas River to
1,000 gpm. High flowrate limits may be exceeded under Alternative C. Addi-
tionally, some debugging may be needed upon installation of the new air
stripper, with potential upset conditions which may cause additional moni-
toring. Copies of the air permit and NPDES permit are found in Appendix A.
Alternatives C, 0, and E all require obtaining leases, easements, or pur-
chasing property to allow for installation of additional extraction wells in
the intermediate aquifer. Obtaining access and necessary permits would be
easier under Alternative E due to the fact that only two wells (compared tc
five wells for Alternatives D and E) would be required.
Summary of Administrative Feasibility
Alternative C would be the most administratively difficult to achieve due to
potential needs for air permit and/or NPDES modifications. Alternatives C and
D wou.ld require more intermediate zone well field development than Alternative
E and much less than Alternatives A and B, which require no new well fields or
treatment systems.
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Final Revisoon
4.3.4.3 Availability of Services and Materials
All the technologies required by Alternatives A through E are available,
demonstrated, and do not require licensing. The treatment methods of carbon
adsorption and air stripping have been well demonstrated by the operation of
the existing treatment plant.
Ground-water extraction is a widely used method for aquifer cleanup. Alter-
native A (No-Action Alternative) is the option with the highest degree of
technical risk. Although natural degradation and dilution will occur, the
specific rate at which this occurs is dependent on each site's character-
istics. The effectiveness of a controlled ground-water extraction plan can be
predicted with greater certainty over simple, natural degradation and dilution
processes.
None of the technologies used by Alternatives A to E would require further
development. Predictive modeling will continue throughout the progress of the
cleanup to verify previous assumptions and assist in making any adjustments to
improve performance. There is no limit to the scale which the technologies in
Alternatives B through E could be implemented. The existing treatment plant
is limited to a treatment capacity of 650 gpm. Alternative C would require
installation of additional treatment capacity. This would delay implementa-
tion due to the time required for design, procurement, delivery, and installa-
tion of the equipment.
Alternatives C, 0, and E require installation of new wells. This will result
in a certain delay time while permits and releases from landowners could be
obtained. Wells must be- installed during the dry season. Damage to fields
may occur if installation is performed during wet weather. There is no reason
to expect qualified drilling contractors would be unavailable. Implementation
of Alternatives C, D, and E would also be delayed while design, services, well
casing, .pumps, utilities, and pipe are procured and installed.
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Alternatives B, C, 0, and E would require operation of the carbon treatment
unit. It is estimated that single-bed carbon change outs will be required
about every three months for the existing unit. This change out period will
lengthen as remediation continues. There is no reason to expect a shortage of
carbon availability, or contractor services to remove and dispose of spent
carbon.
Summary of Availability of Services and Materials
Alternative A would be the simplest alternative to implement, requiring no
services or materials other than monitoring. The monitoring period is longer
than for the other alternatives; however, the operating cost is lowest.
Alternative C has the highest risk of disruption due to lack of services.
However, based on historical operating data, this risk is very low.
4.3.5 Cost
This section summarizes short- and long-term costs associated with the
implementation of Alternatives A through E.
The estimates were prepared based on current operational cost data for the
existing treatment plant, quotes obtained from vendors, and historical cost
data extrapolated to current day value. The accuracy of the estimate is
+35 percent to -20 percent. No inflationary rate factors are assumed in the
cost analysis. No contingencies are included because the costs are well
established from current operations. There should be no significant scope
changes once an alternative is selected for implementation.
Any costs associated with the remediation after the end dates stated in the
cost summary tables are not included in the analysis. These costs may include
legal fees, mandatory site improvements, demolition of the treatment plant,
removing or closure of wells, and any long-term site monitoring (SARA Section
121 (c)). No salvage value was awarded for the existing interim remediation
equipment and no capital cost is incurred by alternatives that make use of
existing equipment.
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Table 4-3 summarizes the detailed cost analysis of Alternatives A through E.
As expected, Alternative A (no action) is the least expensive to implement.
However, it does have the highest risk for not achieving the desired cleanup
levels within the scheduled time period. Alternative A has the highest
potential for^ an overrun of budget due to an extended schedule but is least
likely to overrun due to unforeseen inflation or economic changes.
Alternative B does not require any additional construction. However, Alter-
native B ends up being more expensive to implement due to the long duration,
monitoring, and operating costs.
Alternative C has the highest cost of all the alternatives due to installation
of new wells, and the requirements to expand the treatment plant. Economic-
ally, Alternative C has no advantage over Alternative D which is a similar
'remedial action plan but does not require expansion of the treatment plant.
Alternative C is also predicted to require longer to implement than Alterna-
tive 0 due to modification of permits.
Alternative E is higher in cost than Alternative D due to the predicted longer
duration required for completion and associated monitoring expense.
Potential Future Cost
SARA requires an evaluation of the potential for future remediation. Alterna-
tive A has the highest potential for requiring additional remedial measures.
Alternatives C and D have the least potential for requiring additional
remediation.
The greatest probable additional measures for Alternatives C and 0 which may
be required is a longer pumping duration than estimated. Alternatives A, B,
and E are slow and have a higher potential to be less effective. The most
probable additional measures necessary would be to implement the remedial
strategy of Alternative D. However, the greatest potential future cost
associated with options A, B, and E would be caused by the extended time for
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Final Revision
cleanup. This delay may allow contamination to spread to deeper aquifers and
expand the required cleanup efforts.
Summary of Cost
Alternative A (the no action alternative) would be the most economical option
to implement but carries the highest degree of technical risk. Alternative D
is the most economical of the action alternatives. Alternative D costs only
slightly more than Alternative A and achieves the desired objectives in about
one-third the time of Alternative A with lower technical risk.
4.3.6 Compliance with ARARs
A summary of examination of alternatives versus potentially applicable or
relevant and appropriate requirements is presented in Table 4-1. Alternative
A may not meet ARARs for either the shallow or intermediate aquifers, and
alternative B may not meet ARARs for the intermediate aquifer. In both cases,
the alternatives do not involve remedial action, and an indeterminate time
period would be required for reaching cleanup levels. Reliance on passive,
natural attenuation mechanisms for attainment of cleanup levels for these
aquifers is required. Alternative C will need to obtain modifications of both
the NPOES' and MBUAPCD permits to meet ARARs.
Most of the ARARs and other guidance criteria to be considered are so specific
for this site and actually define numerical remediation goals for chemicals cf
concern. Agency experience has shown that remediation goals may not be tech-
nically feasible to achieve in the modeled timeframes. The remedial alterna-
tive^) include evaluation of system operations and effectiveness at periodic
intervals. In the event remedial goals cannot be achieved, the RAP/ROD may be
amended by invoking the appropriate ARAR waiver. Any such RAP/ROD amendment
would include appropriate public participation.
4.3.7 Overall Protection of Human Health and the Environment
The potential risk to human health and the environment is highest under the
No-Action Alternative A, followed by Alternative B, the remediate shallow
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aquifer only alternative. Both these alternatives present risk of
contaminating the deep aquifers utilized for irrigation and drinking water
purposes by relying on only natural mechanisms and irrigation practices for
dispersion of contaminants.
Under Alternative C, the amount of contaminant capture is expected to be high,
but mass balance releases to the environment may be increased in terms of
quantity and rate. The entrainment of lesser contaminated waters into the
treatment system may result in lower percent contaminant removal.
Alternative D appears to present the best match of protection in all media.
Ground water will be selectively withdrawn to remove the most contaminated
water sources first and affect maximum percent removal. Alternative E appears
to be limited by the number of wells installed into the intermediate zone and
may not adequately capture contaminants migrating to the deeper aquifers, and
hence, be less protective than Alternatives C and D.
Summary of Overall Protection
Alternative D provides the best compromise between allowable air emissions,
contaminant capture, treatment efficiency, and respondent protection of health
andt the environment. Alternative C may extract the greatest amounts cf
contaminants, but removal from the treatment stream and high air emission
levels in reference to the air permits may occur.. Alternative E may net
adequately capture contaminants migrating to the deeper aquifers, Alternatives
A and B most likely will not protect the deeper aquifers from contamination
and potential human health and environmental risk.
4.3.8 State Acceptance
The state concurs with the remedy proposed.
4.3.9 Community Acceptance
There is no community opposition to the proposed rerr.eay. All comments
received have been addressed in the "Response Summary" prepared by the
California Department of Health Services (Section 6 of this report).
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4.4 SUMMARY OF DETAILED ANALYSIS
Table 4-2 provides a comparative summary of detailed analysis of the developed
remediation alternatives. Synoptic summary for each criteria is provided in
Section 4.3. Alternatives A and B do not adequately respond to the ground-
water contamination problem and rely on passive mechanisms to assure ground-
water remediation. Both Alternatives A and B have a high probability of
introducing additional contaminants to the deep aquifer. Alternatives A and B
are potentially low cost and easily implementable. The uncertainties in the
effectiveness of these alternatives, ability to reduce risks due to further
ground-water migration/degradation, and compliance with ARAR's render these
alternatives unattractive.
Alternatives C, D, and E include installation of ground-water extraction wells
into the intermediate aquifer for remediation of contaminated ground water.
Alternatives C and D include installation of five wells into the intermediate
zone; Alternative E includes installation of two wells only. As such,
Alternatives C and 0 are expected to allow greater contaminant capture than
Alternative E.
Although the treatment plant is upgraded under Alternative C, modeling has
shown that high flowrates envisioned under this alternative may entrain large
quantities of uncontaminated ground water. Alternative C may also require
modification of NPDES and MBUAPCD air permits. Significant de.lays in
.installing the new air stripper under Alternative C may occur. Alternative 0
appears to be the alternative best matched to the site conditions, as
supported by this detailed analysis.
FIR:0067-R8S4 4-37
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5.©
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Final Revision
5.0 RECOMMENDED REMEDIAL ACTION
5.1 SUMMARY OF REMEDIAL ACTION
Alternative D is the recommended remedial action alternative, based on the
detailed analysis presented in this FS/RAP (Section 4.0). This alternative is
summarized as follows:
° Installation and development of five (5) new extraction wells in the
120-foot aquifer.
e Disposal Alternative S, which is discharge of treated ground-water to
the Salinas River.
• A new, approximately 1-mile-long pipeline segment is needed to con-
nect the new extraction wells to the treatment plant.
• Treatment consisting of combined carbon adsorption and air stripping
with the existing treatment plant.
• Pumping and treating ground-water from the 120-foot aquifer concur-
rently with the pumping from the shallow aquifer.
• Combined flowrate maintained at or below the capacity of the existing
treatment plant of 650 gpm; the wells will not be pumped at their
maximum flowrates.
• 'Minimum flowrate of 400 gpm from the intermediate aquifer.
• Pump testing of each new extraction well.
• Well field configuration in the intermediate aquifer appears to be
well suited to the site geology.
• Effective short-term, with low impact on the environment during
construction and implementation.
• Monitoring to continue in the shallow and intermediate aquifers until
the concentrations have remained below the ground-water . cleanup
levels for two uninterrupted years..
5.2 ANALYSIS OF GROUND WATER SAMPLES ,
Ground water samples from monitoring, extraction, and agricultural wells are
to be compared with established cleanup levels for each of the ten chenrica:
compounds found at the site. Once the remedial pumping process has reduced
FIR:0067-R8S5 5-1
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Final Revision
all concentrations below cleanup levels, it is planned that the treatment
system will be shut down and placed on standby. Monitoring will continue for
two years, at a frequency to be determined in consultation with the regulatory
agencies.
If a sample from a well that had previously been below the cleanup levels for
any compound shows an increase to a value that exceeds that cleanup level,
immediate well resampling will take place. A group of four replicate samples
(not a four-way split) will be taken. Statistical analysis of the results
will then be used to decide if the initial exceedance was statistically sig-
nificant. The statistical confidence level to be used is 99 percent, with a
1 percent chance of a false negative, that the mean of the four replicates
exceeds the cleanup level. A positive result is a finding from the statis-
tical analysis that the observed exceedance of a cleanup level is statistic-
ally significant. Subject to revision and final determinations during the
detailed design of the selected remedial action system, Student's "t" test
will be used in the statistical analysis. Other approaches to be considered
during final design include control chart methods, tolerance intervals, and
prediction intervals. These are all accepted EPA methods for analysis of
ground water data at RCRA sites.
Under this procedure,'a positive result (i.e., a conclusion that the ground
water concentration has risen above the cleanup level) would mean that the
treatment plant would be reactivated, and wells would be sampled more fre-
quently. The increased sampling frequency would continue until three consecu-
tive period samples show concentrations below cleanup levels for all
contaminants.
5.3 DEEP AQUIFER CONTINGENCY PLAN
It is expected that pumping in the intermediate aquifer will intercept the
plume of contaminants from the site and that pumping in the deep aquifer will
not be necessary. Levels cf contaminants in the deep aquifer, which are (with
few excursions) below the cleanup levels, are expected to decrease. However,
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Final Revision
there is the possibility that the cleanup system will not be as effective as
expected, and that more contamination will reach the deep aquifer. The fol-
lowing is a contingency for this situation.
• The deep aquifer will be monitored on a quarterly basis, or as deter-
mined by the regulatory agencies. This will include analyses for all
of the ten standard contaminants which have been found at the site.
Cleanup levels have been established for these chemicals in this
FS/RAP. Deep monitoring wells and agricultural wells will be
monitored.
• Monitoring Information will be used to evaluate the effectiveness of
the pumping from the intermediate aquifer. If deep aquifer wells
show a rise in concentrations, adjustments will be made, if possible,
to the intermediate pumping system to halt the spread of contaminants
._ to the deep zone.
• If the concentration of any contaminant in any deep well is found and
confirmed to be above the cleanup levels established by this FS/RAP,
the frequency of sampling for that well and the immediately surround-
ing wells will be increased to monthly. This frequency may be
adjusted by the regulatory agencies. Sampling will continue on a
monthly (or as-specified) basis for any such well until three con-
secutive periodic samples show concentrations below cleanup levels
for all contaminants. Sampling frequency will then revert to a
quarterly basis. As remediation nears completion, Firestone may
petition DHS to further reduce the sampling frequency of such wells.
8 If the concentration for any contaminant in a deep well remains above
the cleanup level for more than one year, starting from the time the
intermediate aquifer pumping begins, or if any concentration is found
at any time which exceeds ten times the cleanup level, then:
1) Firestone will provide, for any domestic or drinking water we"!
with concentrations above cleanup levels, a wellhead treatment
system, bottled water, or other interim means of effectively
protecting public health which is approved by the regulatory
agencies.
2) For agricultural wells with concentrations above cleanup levels,
Firestone will implement crop uptake testing and report the
results to the regulatory agencies, who will then determine if
further action is necessary.
3) Firestone will submit to DHS, within . ninety days and in
accordance with the requirements of the involved agencies, a plan
for remediating the deep aquifer.
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Final Revision
Firestone will provide the wellhead treatment, bottled water, or
other approved protection on a shorter time frame than that outlined
above if the regulatory agencies determine, due to changing or
unforeseen conditions, that there is an imminent threat to public
health or the environment from deep aquifer contamination.
If the concentration for any contaminant in a deep well remains above
the cleanup level for more than eighteen months, or above ten times
the cleanup level for more than three months, starting from the time
that the Intermediate zone pumping begins, then Firestone will imple-
ment the modified remedy according to the plan mentioned in item 3
above, as approved by the regulatory agencies. The public will be
fully informed of any changes to the treatment system at the time of
implementation. If any changes require a full RAP/ROD amendment,
then the public will be fully involved as required by law before any
such plan is implemented.
If data from deep aquifer monitoring wells indicate that the down-
gradient extent of contamination in the deep aquifer is no longer
known, then Firestone will monitor wells located further downgradient
until the extent of- the plume is again known. It is possible that
there are other local sources, of chemicals in the deep aquifer,
particularly at the northwesterly end of the plume.
FIR:0067-R8S5 5-4
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A
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STATE Of CAllfOBNIA— HEAITH AND WELFARE AGENCY GEORGE DEUKME1IAM, Coemor
DEPARTMENT OF HEALTH SERVICES
TOXIC SUBSTANCES CONTROL DIVISION
•M51 BERKELEY WAY. ANNEX 7
RKELEY, CA 94704
6.0 RESPONSIVENESS SUMMARY
FORMER FIRESTONE TIRE AND RUBBER SITE
Analysis of Public Comments
Received on Draft RAP
August 14, 1989
I. Introduction
On July 13, 1989, the California Department of Health
Services held a public meeting on the proposed remedial
action plan for the former Firestone Tire and Rubber site,
located in Salinas, Monterey County, California. The
purpose of the meeting was to provide the public with
information regarding the remedial action plan and to
solicit public comments on the adequacy of the plan. In
addition, comments on the remedial action plan were
submitted to the Department during the public comment period
which extended from June 27, 1989 to July 26, 1989.
The verbal and written comments which were received during
the public meeting and comment period have been compiled
according to the agency, individual or meeting. The purpose
.of this document is to present a written response by the
Department to these comments.
A copy of the transcript of the public meeting and all the
written comments received are available for review at:
Toxic Substances Control John Steinbeck Library
Division 110 West San Luis Street
Region 2 Salinas, Ca 93901
5850 Shellmound, Suite 100
Emeryville, CA 94608
By Appointment Only
(415) 540-3401
II. Comments and Responses
The verbal and written comments which were received have
been compiled and categorized by the following agencies,
individuals or meetings:
A. Environmental Protection Agency
B. Public Water Supply Branch
C. Office of Planning and Research
D. Roy W. Fowler, Jr.
E. July 13, 1989 Public Meeting
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RESPONSE SUMMARY
A. DBS RESPONSE TO EPA ADDENDUM ON FEASIBILITY STUDY/REMEDIAL
ACTION PLAN FOR FIRESTONE, SALINAS
Note: Underlined text indicates language proposed by EPA.
la. EPA Comment:
Page 3-4, Section 3-2, Paragraph 2: "above the drinking
water action level." What action level? For which
compound? This should be revised to reference the cleanup
levels. If DCE is referred to, a rationale as to why it is
a valid indicator parameter should be provided in the FS.
DHS Response;
DHS is in agreement with EPA that this statement needs to be
clarified. The phrase "drinking water action level" will be
changed to state that the plume maps show areas above the
cleanup levels shown on page 2-6.
1,1-DCE is referred to in section 2.2 and on page 3-4.
Rational for using 1,1,1-TCA and 1,1-DCE concentrations as
indicator chemicals has been expanded. This includes
referencing earlier observations that showed a decrease in
other chemical concentrations as the concentration of DCE
declined.
Ib. EPA Comment;
Page 3-17 implies that No-action cleans up the aquifer.
This implication should be removed. No-action would imply
an escaping groundwate,r plume at concentrations above the
action levels. While it is possible that after a long
period of time concentrations would reach action levels by-
dispersion, it is not within common parlants to refer tc
dispersion and dilution as "cleanup".
DHS Response;
In order to clarify any misunderstanding caused by this
paragraph, the following statement (which is also found in
section 4.2.1) is included:
Alternative A, the No-action alternative, is required by
regulatory guidelines and is considered as a baseline
alternative.
2. EPA Comment;
Page 4-9, 4-10. for Alternative A state or imply that the
alternative "cleans up" the aquifer. This language should
be removed or qualified clearly (see comment [Ib]).
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Final
3.
4.
DHS Response:
DHS does not believe that any implication is made that would
suggest that Alternative A is a feasible alternative;
however, the following language is added to clarify the
definition of "cleanup" :
This discussion under Alternative A is not meant to imply
that No-action will cleanup the aquifer, rather that after
some time, the observed concentrations of chemicals in the
aquifer will decrease to below the groundwater clean up
levels due to natural attenuation, degradation and
diffusion.
EPA Comment:
Paragraph 2: "Although the proposed NCP rule
51394 has not been promulgated and the
has only been issued as a draft
provide ?&X&ywit/$i#$//?L$$i!0$?Z&-t2
." The stricken language is
ARARs
Page 4-3,
revisions at 53 FR
March 1988 RI/FS guidance
document, these documents
information on
inappropriate given the parallel it invokes.
DHS Response:
DHS feels that the language may be mistaken to mean
and therefore concurs with EPA's change.
EPA Comment:
Page 4-4, Paragraph (b). Add as last sentence: Compliance
with ARARs is a threshold requirement. All alternatives
remaining in the final analysis shall meet ARARs or have an
approved ARAR waiver. It was not clear from the report that
Firestone understands that meeting ARARs is not an optional
exercise (although it is stated fairly clearly in Paragraph
1, page 4-8). By statute, ARARs must be met and
alternatives which do not meet ARARs cannot be retained for
analysis.
DHS Response;
While the last paragraph on page 4.7 states that
alternatives that do not comply with ARARs will not meet
statutory requirements for selection of remedy in the ROD,
EPA's suggested language is added to page 4-4, paragraph
(B). With the following change: "...have approved ARAR
waivers" to "...obtain ARAR waivers".
5. EPA Comment:
Page 4-8, Section 4.2.1,
Sentence 3.
The "no-action" alternative is defined as
being the current site conditions, absent the ongoing
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Final
remedial measures. The ongoing remedial measures consist of
pumping and treating the qroundwater with carbon adsorption
and air stripping, and discharging the treated water to the
Salinas River. Continued groundwater monitoring is not
considered a remedial measure.
DHS Response;
The text has been changed to reflect EPA's concerns with the
exception of the last sentence. DHS feels that this
statement would be redundant given the fact that it has
already been stated that Alternative A is not considered a
remedial measure and a definition of cleanup has been
provided.
6. EPA Comment;
Page 4-10, Section 4.2.2, paragraph 2: "...That no yftfyfs'^a'J
{{see below}} increases occur in the concentrations of
chemicals in the ground water. After two years of
monitoring with no ytyyi&YlftX {{see below}} increase in
concentrations, all or portions..." The word "unusual is
undefined and unclear. What is an "unusual" increase? Is
"unusual" based on statistical significance? What numerical
criteria shall be used to define significance? These should
be added. Also, it is not clear from this discussion
whether the two years will start over if there is a
significant increase.
This same comment applies to the word "unusual" on Paaes
4-12, 4-13, 4-18 and 4-20.
Connected to this issue is the fact that CERCLA Section
121(c), 42 U.S.C. 9621(c), requires that there be a reviev
of hazardous waste cleanups, where hazardous substances
remain on-site, at least every five years to ensure that the
remedy remains protective of human health and the
environment. The five years are counted from initiation of
the remedy. If the remedy does not remain protective, EPA
is instructed to use its cleanup authorities once again to
address the problem.
Thus, Firestone could technically dismantle its treatment
plant after two years with concentrations below cleanup
levels. It would merely be necessary to maintain enough
monitoring wells to review the cleanup effectiveness after
five years. However, if levels increased for any reason,
Firestone would be taking a great risk that an EFA CERCLA
Section 106 Order would be issued requiring them to
reassemble the treatment plant. As is clear to Agencies
now, there are many instances where pump-and-treat systems
are shut down and the resulting change in equilibrium causes
a desorption of contaminants and an attendant rise in
contaminant concentrations.
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Final
In order to minimize Firestone's risk as well as protect
public health, EPA therefore recommends that two conditions
be met before the plant is dismantled: two years of
monitoring, with treatment operating, in which no well show
levels above the cleanup criteria; and two years of
monitoring with the pumps shut off entirely, in which
contaminant levels do not rise above cleanup levels for any
contaminant. A review of the effectiveness can then be made
at the five-year point, and also at the end of the process,
if the end comes at a time later than five years from
initiation of the remedial action.
In order to address the vagueness of "unusual", and the
five-year review issue, the referred wording to be added
under each remedial alternative (except A) is as follows:
The shallow and intermediate aquifer extraction system
(including extraction wells) shall not be abandoned until
there has been;
1) with treatment operating, an uninterrupted two year
period with no statistically-significant increase in
concentrations for any chemical, nor any concentration above
the cleanup levels established by this RAP;
2) with treatment shut down completely, an uninterrupted two
year period with no concentration for any chemical above the
cleanup levels established by this RAP.
The above two conditions shall apply over the entire aquifer
system as a whole; not for one aquifer or the other
separately.
Effectiveness reviews shall be performed by DHS and/or EPA
after five full years from the initiation of the cleanup
action, and again before the dismantling of the extraction
system, if dismantling occurs after five years of initiation
of the cleanup action.
As cleanup progresses, certain monitoring wells may be
properly abandoned by Firestone. such abandonments shall
require the prior approval of DHS and/or EPA in writing.
After the extraction system is dismantled, certain
monitoring wells shall remain available for sampling;
Firestone shall apply to DHS and/or EPA at the tine of
dismantling to identify the wells which are to rer.air.
available.
A numerical criterion for "statistical significance" should
be included.
DHS Response:
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F.inal
The term "unusual" has been deleted from the text. In its
place, the text under each alternative states that Firestone
is currently required to monitor the intermediate and
shallow aquifers and will continue to do so in order to
verify that no concentrations of chemicals exceed their
cleanup levels as established by this RAP. If any chemical
in any monitoring well sample is detected above its cleanup
level, and the analysis is confirmed, the treatment plant
will be started up again.
The monitoring period for groundwater will continue for 5
years from the start of the initiation of the final remedy
or for a two year period after reaching cleanup levels,
whichever occurs later. Chemical concentrations must remain
below cleanup levels for an uninterrupted two year period or
the two year monitoring period will begin again.
7 . EPA Comment;
It is indicated on Page 4-18 that the shallow aquifer
extraction wells will be shut down as early as August 1989.
The wording of this alternative should be expanded to make
it clear that remedial design will determine the pumping
rates used from all the wells. While it should still be
noted that the wells may be shut down, it is still possible
that the wells will be pumped for some time. for example:
Shallow wells = 100 gpra, Intermediate wells = 550 gpm, is
possible.
DHS Response:
The following wording will be added after the first sentence
of section 4.2.4.3:
The pumping scenario described below is for modeling
purposes only. For actual conditions, pumping rates will be
based on the monitoring well design and the results of
aquifer testing and monitoring. Both shallow and
intermediate aquifer wells can be pumped at the same time.
However, the pumping rates for all intermediate aquifer
wells combined will have a minimum of 400 gpm.
8. EPA Comment;
The "Compliance With ARARs" section has several problems.
The greatest of these is that it is not clear from the
report that the list of ARARs in the Tables will actually be
complied with under the RAP. Also of concern is that ARARs
are referenced summarily as "ARARs" rather than
specifically. Rather that (sic) explain each problem in
detail, we have provided our recommended text changes to
solve these problems in as expeditious a manner as possible.
The text here is from Section 4.3.6. Stricken text is shown
Additions are shown in italics (for purposes of
6-6
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Final
this summary, they are shown underlined) . Comments in
are in double brackets { { } } . This issue is critical.
text
"A summary of alternatives versus potentially applicable or
relevant and appropriate requirements is presented in Table
4-1. 'Alternative A may not meet #&#&& {{give specific ARARs
it may not meet and why)} for either the shallow or
intermediate aquifers. Alternative B may not {{why not?})
meet #£#££ ({give specific ARARs}} for' the intermediate
aquifer. Reliance on passive, natural attenuation
mechanisms for attainment of cleanup levels for these
aquifers will occur. W{J«Y Alternative C will meet ARARs if
permit modifications of both NPDES and MBUAPCD permits %$
are obtained.
Most of the ARARs and other guidance
criteria to be considered are z"0 specific for this site and
actually define numerical remediation goals for chemicals of
concern. Agency experience has shown that remediation goals
may not be technically feasible to achieve in the modeled
timeframes. The remedial alternative(s) include evaluation
of system operations and effectiveness at periodic
intervals. Should the ability to obtain remediation coals
become doubtful, the RAP will be amended accordingly and/or
the appropriate ARAR waiver invoked. Any such RAP and ROD
amendment would include public participation in amending the
decision.
£. . . { {strike to end of paragraph. Compliance with ARARs is
a threshold criterion. If any of the alternatives A-E does
not meet ARARs (i.e. those without available waivers), it
should not be in the running for the final detailed
analysis. } }
"4.3.7 Overall Protectiveness of
Environment
Human Health and the
"The potential risk to human health and the environment,
#}WWti$/ttm//?#ty/Wy), is highest under the No-Action'
Alternative A, followed by Alternative B, the remediate
shallow aquifer only alternative. Both these alternatives
present risk of contaminating the deep aquifers utilized for
irrigation and drinking water purposes by relying on only
natural attenuation mechanisms and irrigation practices for
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Final
dispersion of contaminants.
( {The proper
place for such statements is in the summary of site risks or
in the RI ,. not here . } >
"under Alternative C, the amount of contaminant capture is
expected to be high, but mass balance releases to the
environment may be increased in terms of quantity and rate.
{{This should be
discussed under Implementability. } } The entrainment of
lesser contaminated waters into the treatment system may
result in lower percent contaminant removal .
"Alternative D appears to present the best match of
protection in all media.
{{This is an artificial
constraint as far as the Agency is concerned; therefore it
is not a consideration. It may be included in the
Implementability Section, however. }}..."
"Summary of Overall Protection
"Alternative D provides the best compromise between
jLJLJLW&M//fjL]t//£jlijLM]Lfi1lt contaminant capture, treatment
efficiency, and respondent protection of health and the
environment. Alternative C may extract the greatest amounts
of contaminants ,
but result in lower removal efficiency. ..."
...Skip to page 4-35, Paragraph 2, last sentence:
"As such, Alternatives C and D are expected to allow greater
contaminant capture than Alternative E,
{(This is not a
consideration here.)} ..."
DHS Response; .
Section 4.3.6: The text has been revised to state that
Alternatives A and B do not include remedial action and that
an indeterminate time period would be involved for reaching
clean up levels in the aquifers. All other suggested
changes have been incorporated into the text.
Summary of ARAR Compliance: This is an editorial comment
that would not change the conclusion of the FS/RAP. The
"Summary of ARAR Compliance" section does not specifically
6-8
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Final
state which ARARs will be violated nor which waivers would
need to be invoked; however, with the additional language
requested for Section 4.3.6., this summary is no longer
necessary and has been deleted.
Section 4.3.7.: All recommended deletions have been made,
"Summary of Overall Protection"; DHS feels that the
statement "... allowable air emissions..." should remain in
the text. Air emissions from the treatment plant could
present a health risk if allowable concentrations are
exceeded, and therefore should be considered under overall
protection.
The remaining deletions and additions indicated have been
incorporated into the text.
9. EPA Comment:
The wording which was added in the ARARs section, regarding
the contingency if ARARs are not met, should be added to
each (accept for Alternative A) of the final alternatives
discussed:
It is recognized that the results of computer models have
limitations, and therefore the best available predictions of
ability and time to meet ARARs may not be accurate. This is
not expected; however, this remedial alternative would
include evaluation of system operations and effectiveness at
periodic intervals. {{specify as closely as possible}}
Should the ability to obtain remediation goals become
doubtful, the RAP will be amended accordingly and/or the
appropriate ARAR waiver invoked. Any such RAP and ROD
amendment would include public participation in amending the
decision.
DHS Response;
This statement with some minor modifications will be added
at the end of each alternative discussion (except for A):
It is recognized that the results of computer models have
limitations, and therefore, the best available predictions
of ability and time to meet ARARs may not be accurate.
Therefore, this remedial alternative would . include
evaluation of system operations and effectiveness on a
semi-annual basis based on monitoring data. In the event
remedial goals cannot be achieved, the RAP/ROD nay te
amended accordingly by invoking the appropriate ARAR waiver.
Any such RAP/ROD amendment would include appropriate public
participation.
10. EPA Comment:
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Final
Page 4-29 does not mention the permit limits on the air
stripper, nor for the NPDES permit. This is critical
information to the FS as it is a primary ARAR for the
preferred alternative. The discharge limits, for mass rate
and contaminant loading, where applicable, should be
provided in full and be easily accessible.
DHS Response;
The maximum flow rates for the air stripper and NPDES
permits are given on page 4-28. In addition, copies of
these permits are included in Appendix A for reference. For
clarity, the text was revised to refer the reader to
Appendix A.
11. EPA Comment;
The plume diagrams shown in the simulations show a piece of
the intermediate zone plume moving off downgradient. While
the capture zone figures seem to show that the plume is
captured, there is uncertainty. This is an extremely
critical issue. The RAP should be explicit as to the
testing to be performed and as to how extraction wells shall
be sited in order to ensure that the plume is captured. The
following suggested language is provided to be added to all
alternatives at the point that well siting is discussed.
This pertains .to Alternatives C, 0, and E:
A primary objective of the remedial effort shall be to
ensure that the plume of contaminants in the intermediate
aquifer is completely contained. Accordingly, once the nev
extraction wells are installed, they shall be immediately
sampled for contaminants to determine the real
concentrations at the well points. If necessary, one or
more additional wells will be installed further downgradient.
and/or pumping rates adjusted to ensure that the capture
zone is completely containing any portion of the plume with
contaminant concentrations above the cleanup level for anv
contaminant.
Once pumping has commenced, aquifer tests shall be performed
to verify the true zone of capture for the wells. If
necessary, another well will be installed further
downqradient and pumping rates adjusted accordingly so that
any portion of the plume containing concentrations above the
cleanup levels for any contaminant is contained. The
results of this assessment shall be reported to DKS and
copied to EPA.
DHS Response:
The concerns raised in this comment are mainly the result of
the limitations of the computer models used. However, these
limitations are not spelled out, and therefore the diagrams
could easily be misinterpreted by the uninitiated reader.
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Final
In order to mitigate this potential problem, the text has
been revised to state that a primary objective of this
remedial effort shall be to establish a zone of capture for
the chemicals above cleanup levels in the intermediate
aquifer. New extraction wells will be sampled for
contaminants. If necessary, additional wells will be
installed further downgradient and/or pumping rates adjusted
to ensure that the capture zone intercepts any portion of
the plume with contaminant concentrations above the cleanup
level. . .
The inclusion of the following statement, "The results of
this assessment shall be reported to DHS and copied to EPA"
is not necessary in this report as it will be included in
the Remedial Design.
12. EPA Comment:
Given that there is contamination in the deep aquifer (below
the 120-foot zone) there should be a contingency in the RAP
for the possibility that the deep zone comes to have
contaminants above the cleanup levels. Such a contingency
could likely be carried out by adding more wells in the deep
zone and modifying the treatment plan (including the NPDES
and air permit) to increase plant capacity. This would
probably require a public notice but would not represent a
fundamental change to the remedy and thus would not require
a RAP or ROD amendment nor a second public comment period.
The probable schedule for implementing such a contingency
system, along with the general design parameter, should be
included.
In order to plan for this contingency, Firestone should
submit requests for "contingent" NPDES and air permit
modifications to the appropriate agencies immediately.
These would request approval for flow rate increases in the
event, and only in the event, that deep aquifer levels go
above the cleanup levels. This approach has been used
effectively on other sites. This would allow action to be
taken quickly if pumping in the deep aquifer becomes
necessary.
It is recommended that a contingency plan, including such
permit requests, be spelled out in the RAP to address this
possibility. This should indicate that public notice, via
local newspapers, would be given if such changes are carried
out.
DHS Response;
Modifications to the existing NPDES permit is not an option
available to Firestone at this time. DHS discussed this
contingency with the Regional Water Quality Control Board
and was told that the the Board will not issue contingent
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Final
NPDES permits. In addition, it is DHS' opinion that cleanup
of the deep aquifer by EPA's proposed method would require
• major modifications to the existing treatment plant and
significant increases in groundwater extraction rates. Such
changes would require amendments to the State's RAP, and
also an additional public comment period.
As a contingency in the event that the intermediate aquifer
extraction system is not found to be effective in
maintaining chemical concentrations in the deep aquifer
below the established cleanup levels, the regulatory
agencies will re-evaluate the extraction system and deep
aquifer, and take the appropriate actions.
A contingency for the deep aquifer has been added to section
5 which will include monitoring of the deep aquifer and an
evaluation of the intermediate zone extraction well system«
If any chemical concentration is found above its cleanup
level, monitoring of that well will be increased. If the
concentration of any chemical in a domestic or drinking
water well in the deep aquifer•remains above its cleanup
level within one year of the initiation of pumping in the
intermediate aquifer or if any concentration is found at any
time to exceed ten times its cleanup level, then a well head
treatment system shall be established for that well or an
alternate drinking water source shall be provided. If the
same conditions are found for the deep aquifer agriculture
wells, the crop testing program specified in the Remedial
Action Order will be instituted.
If after eighteen months of the initiation of pumping in the
intermediate aquifer the concentration of contaminants in
the deep aquifer remains above cleanup levels or above ten
times the cleanup levels for more than three months, then
Firestone will submit to DHS within 90 days, and ir.
accordance with the requirements of the involved agencies, a
proposal for modifying the remedial system to include the
deep aquifer.
In addition, if data from the deep.aquifer monitoring wells
indicate that the downgradient extent of contamination of
the deep aquifer is. no longer known, then Firestone will
install additional monitoring well(s) until the extent of
the plume is known again.
13. EFA Comment:
Figures 3-2 through 3-8, 4-1, 4-2, 4-3, etc. show contours
without labels. These should be labeled with the
appropriate level and units. If these are 6 ppb contours
for DCE, it should be shown or discussed in the text as to
why DCE is a valid indicator for plume extent. Are there'
instances where DCE is below 6 but other parameters are
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above their cleanup level? Where might this be true?
Indicate in the text.
DHS Response:
Contours in figures 3-2 through 3-8, 4-1, 4-2, etc. have all
been appropriately labeled. Monitoring well data shows that
DCE or TCA is the dominant chemical found in the wells. In
addition, the rational for using DCE is included in Sections
2 and 3 as stated earlier.
DHS Responses to Public Water Supply Branch (PWSB)
PWSB Comment:
Section 2.2.2 Allowable Concentrations Based on Risk
Assessment
The maximum contaminant levels (MCL) for several organic
chemicals listed on page 2-2 need to be revised and
incorporated into the list. The chemicals, MCLs, and
effective dates are as follows:
Chemical
MCL (uq/1)
Effective Date
Carcinogens:
1,2-DCA 0 . 5
PCE 5
Benzene 1
Noncarcinogens:
1,1-DCE 6
Ethylbenzene 680
Xylenes (*) 1750
April 5, 1989
May 5, 1989
February 25,1989
February 25, 1989
February 25, 19.29
February 25, 1939
(*) For a single isomer or sum of isomers
2-2 have been revised to incorporate
DHS Response;
The MCLs on page
list provided.
PWSB Comment:
Section 4.0 Detailed Analysis of Remediation Alternatives
The Public Water Supply Branch concurs that Alternative D is
the most feasible, timely, cost effective, and technically
acceptable alternative available to decrease contaminant
levels in the intermediate aquifer. However, the PWSB has
concerns with respect to remediation of the deep aquifer.
In reviewing the various alternatives, there is no provision
to continue to monitor the deep aquifer wells, for an
assessment of the data, and for a determination to be made
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Final
if remediation of the deep aquifer is needed. It appears
that final remediation will only be limited to ' the
intermediate aquifer. In Fact Sheet #9, June 28, 1989,
there is no indication that contamination of the deep
aquifer has occurred.
Data from the Harden 12 AG well has been used to determine
the trend of concentrations of chemicals in the deep
aquifer. This source shows a decreasing trend of 1,1-DCE
over a three year period. Based on this trend, the report
has indicated that a downward trend is also expected of
Wells ITM17A and ITM18A, which have 1,1-DCE levels above
drinking water standards.
In addition, the report indicates that "Because agricultural
use of the. water has generally decreased the concentrations
to a relatively low level of chemicals in the aquifer or has
prevented large increases of concentrations of chemical,
and, this can be expected to continue in the future, no
alternative requiring additional extraction wells are
planned for the deep aquifer."
A review of data from other deep aquifer wells,
specifically, California Water Service company Station 21,
Well ITM117A, and Well ITM18A, shows an increasing trend of
1,1-DCE over a one to three year period. Based on the trend
of these wells, the proposal of no need for remediation of
the deep aquifer seems premature.
The PWSB recommends that: (1) the deep aquifer wells
continue to be monitored during remediation of the
intermediate aquifer, (2) water quality data from the deep
aquifer wells be reviewed to determine if contaminants
present are at an acceptable level for public health
protection, and (3) the need for further remediation of the
deep aquifer be based on water quality data from the deep
aquifer wells, not the intermediate aquifer wells.
DHS Response:
DHS is in agreement with the PWSB. Firestone is currently
required to monitor the deep aquifer and will continue to be
required to monitor the shallow, intermediate and deep
aquifers in order to verify that no chemical . concentrations
occur above the cleanup levels established by this RAP. If
any chemical in any monitoring well sample is found to be
above its cleanup level, and the analysis is confirmed, the
treatment plant will be started up again.
The monitoring period for groundwater will continue for 5
years from the start of the initiation of the final remedy
or for a two year period after reaching cleanup levels,
whichever occurs later. Chemical concentrations must remain
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Final
below cleanup levels for an uninterrupted two year period or
the two year monitoring period will begin again.
As a contingency in the event that the intermediate aquifer
extraction system is not found to be effective in
maintaining chemical concentrations in the deep aquifer
below the established cleanup levels, the regulatory
agencies will re-evaluate the extraction system and deep
aquifer, and take the appropriate actions.
Please refer to EPA comment number 12 for a description of
the contingency.
3. PWSB Comment:
Table 2-5, Organic Constituents, Water Quality Goals - Human
Health and Welfare
The State adopted MCLs for tetrachloroethylene (PCE),
1,1,1-Trichloroethane (TCA) and Trichoroethylene (TCE) need
to be added under the heading of "State and EPA Drinking
Water Standards, MCLs, State". The MCL and effective date
of the chemicals are as follows:
Chemical MCL (uq/1) Effective Date
PCE 5 May 5, 1989
TCA 200 February 25, 1989
TCE . 5 February 25, 1989
DHS Response:
The MCLs for PCE, TCA and TCE have been added to Table 2-5.
C. Comment from Office of Planning and Research:
The State Clearinghouse submitted the above named environmental
document [Firestone Tire and Rubber Co., Remedial Action Plan
SCH# 89062710] to selected state agencies for review. The state
agency review period is now closed and none of the state agencies
have comments.
DHS Response:
None required.
D. Comment by Roy W. Fowler, Jr.:
At our meeting on April 19, 1989 at Spreckles, representatives of
Firestone Tire and Rubber Company reviewed salient aspects of the
Remedial Action Program and the proposed Negative Declaration for
the above captioned project.
Since I have not heard anything further as to the schedules for
public comments, I am forwarding a letter to you that I sent to
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Final
Firestone which, in part, describes the general area of my
concern, i.e., well abandonment and recharge.
Please place this letter into the file as my interim comments and
please send me your most recent schedule for public comment time.
DHS Response;
OHS acknowledges that there is a proposal to reuse the treated
water from Firestone's treatment plant and to install more
production wells. Any new proposals of this nature would have to
consider the impact on the migration of the groundwater plume as
well as its impact on the recharge of local groundwater flow by
addressing the issue in an Environmental Impact Report.
E. July 13, 1989 Public Meeting:
Comments and responses may be found in the copy of the meeting
transcript which is included in this summary as appendix A.
6-16
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APPENDIX A
2
3 PUBLIC MEETING
FORMER FIRESTONE FACILITY
4 SALINAS, CALIFORNIA
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7 SALINAS HIGH SCHOOL AUDITORIUM
JULY 13, 1989
8 7:00 P.M.
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16 DEPARTMENT OF HEALTH SERVICES
Ms. Shirley Buford
17 Mr. Ric Notini
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FIRESTONE:
19 Dr. Alan Altenau
20
IT _C_0 RPORATION:
2.1 Mr. Chan Weisel
Dr. P.. Nichols Hazel wood
22 Mr. R. Leonard Allen
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SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 HEARING COMMENCED AT 7:20 P.M.
2 SHIRLEY BUFORD.:., Good evening, ladles and
3 gentlemen. I'd like to welcome you tonight to the
4 Remedial Action Plan and the negative dec and the
5 " proposed alternatives meeting for the Firestone site
6 facility here in Salinas.
7 My name is Shirley Buford. I am with the
8 Department of Health Services, community relations
9 coordinator, and I will be your moderator tonight and
10 also will present to you the speakers from the
11 Department of Health, Firestone, the IT Corporation,
12 and also there are members here from the Environmental
13 Protection Agency and the Water Control Board -
14 Central Coast of San Luis Obispo.
15 I would like to talk with you just a little bit
16 about the purpose of this meeting tonight. It is to
17 involve you, the public, in the decision that will te
18 . ir.ade on the final cleanup plan for the Firestone
19 facility.
20 Community relations is mandated by both federal
21 and state laws and it usually involves us getting
22 involved and getting into the community at the very
23 beginning of discovering a site with hazardous
24 wastes. During the process of the cleanup we held
25 public meetings, provide fact sheets and other
26 information for the public, including making a place
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for documents to be placed for the public to corr.e arc?
look at; that's called an information repository. In
this case the information repository is locatec at the
John Steinbeck Library. And in that library you will
find the nine fact sheets distributed by Firestone,
information on the meetings that were held during the
process of the cleanup, and various documents related
to the cleanup at the site.
We also mandate that Firestone develop a mailing
list and inform the community around the facility of
the investigation and the cleanup work taking place
there.
Tonight you all have picked up an agenda, I hope,
from the front. We'd like to go through, for your
information, the people who will be speaking to you
tonight will be Mr. Ric Notini from the Department of
Health Services. Ric Notini is the chief of the site
mitigation unit.
We have Doctor Alan Altenau. Doctor Alter.au is
the director of technology for Firestone. He is
responsible for all environmental work and research
and de-velopment, including quality assurance ar.c
industrial hygiene.
Next on our agenda is Mr. Chan Weisel who is the
general manager for IT Corporation for Northern
California. He is the project director for the
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 Firestone Salinas works.
2 Doctor Nick Hazelwood is the senior, technical
3 specialist and route manager for the IT Corporation,
4 and he is in charge of preparing Firestone risk
5 assessment.
6 And finally on our agenda we have Mr. Leonard
7 Alien who is the senior project manager and
8 geotechnical engineer in charge of the Remedial
9 Investigation and Feasibility Study for the Firestone
10 facility.
11 After the.presentations, we will put together a
12 question and answer panel. And there is some other
13 agency people I will introduce to you later who will
14 be available to answer questions on the site, on the
15 Remedial Action Plan draft, and the proposed plan for
16 cleanup.
17 . At this time I'd like to introduce Mr. Ric Notini
18 from the Department of Health Services.
19 RIC NOTINI: Thank you, Shirley.
20 What I would like to do over the next few minutes
21 is briefly describe the process of cleaning up a
22 hazardous waste site in California.
23 The State Department of Health Services is
24 responsible for investigating and remediating
25 hazardous waste sites in California. We are presently
26 involved in the investigation and cleanup of over 300
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sites across the state, and Firestone is one of those
sites.
The topic that I am supposed to talk about is the
state process. What that really refers to is a
process that we have established to help insure that
these sites are cleaned up to a satisfactory degree.
Every site that we're actively working on is describee!
in a report called Expenditure Plan for the Hazardous
Substance Cleanup Bond Act of 1984. It was a law that
was passed in 1984 that provided us funding to oversee
the investigation and cleanup of the sites. So
Firestone is one of the 300 sites that's discussed in
this report. And this report also describes in a let
more detail the process that I am going to briefly go
over.
I want to first mention that the process of
investigating and cleaning up a hazardous waste site
involves a lot of different agencies and requires a
lot of coordination. And I just want to acknowledge
the assistance and help that we have gotten from a
number of other agencies including the Monterey County-
Health Department, the Regional Water Quality Control
Board, and the Federal Environmental Protection
Agency. We do have representatives from those
agencies here, so if you come up with a question
specific to that agency, we'll ask them to help us
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 out.
2 I have.a co.uple of: overheads;. I want to show and I
3 am going to have to step away from the mike, so I will
4 try to speak up a little louder.
5 This overhead shows the two laws that we use to
6 investigate cleanup sites. There is the Federal
7 Superfund Law, which is also — the long name is
8 actually called the Comprehensive Environmental
9 Response Compensation and Liability Act, commonly
10 referred to as Federal Superfund. And the State
11 Superfund Law has the Hazardous Substance Cleanup Bond
12 Act. These are the two laws that provide us the
13 authority to investigate and cleanup these sites.
14 Now this Firestone site is actually considered
15 both a State Superfund site and a Federal Superfund
16 site. Back in 1987 the Firestone site was proposed cr
17 actually added on to the Federal Superfund list, which
IB is known as the National Priorities List. So the
19 cleanup is going to have to satisfy not only State
20 requirements, but Federal requirements as well.
21 If I could show the next overhead. This gets
22 into the cleanup process, and I will move through this
23 rather quickly. The first step involves discovering
24 the site. And the first thing we do when we receive
25 either a complaint from a citizen or a report from a t
26 company or perhaps another agency refers some
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information to us indicating that there has been a
leak or spill of a hazardous substance, we conduct a
preliminary site assessment. We try and determine if
there has, in fact, been a spill or leak, whether or
not that spill or leak presents an actual or potential
threat to public health or the environment.
•
Based on that, if we decide it it looks like a
significant enough of a problem, we move to the next
step, which is the Remedial Investigation. What that
really means is defining the problem, finding out what
is the nature and extent of the contamination, and
what kind of a threat does it pose to public health or
the environment. That study involves going out and
collecting samples of soil, air and groundwater, very
often, and typically takes several years to complete.
Now during that time if there are some things
that we can do right away to begin to address the
problem, we call those interremedial measures. Anc,
in fact, at the Firestone site back in '84 and '85,
.they actually excavated contaminated soil and
installed some wells and began extracting some of the
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contaminated groundwater.
Once the Remedial Investigation is completed the
next study we perform is a Feasibility Study, which
really means trying to determine what's the best way
to complete the cleanup, looking at various
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alternatives. And that is what v/as recently completed
by Firestone.
In addition to that, the next step involves
preparing a Remedial Action Plan. And the Remedial
Action Flan summarizes the results of the Remedial
Investigation and Feasibility Study and discusses the
cleanup alternative that is being proposed.
In addition to that we are required to hold a
public meeting and provide for a 30-day public comment
period. And we review and solicit comments from you
and review those comments, prepare a written response
to those comments before approving of a final Remedial
Action Plan.
So Shirley mentioned that we have a public
comment period now which ends, I believe, the 27th of
July. You have until then to provide us with your
comments. We will review those and then try and
approve of a Remedial Action Plan based on the
comments we have received.
Following the Remedial Action Plan, Firestone
will be required to prepare a remedial design, which
involves all the engineering design necessary to
install the systems that they propose. Then they are
required to implement it and operate and maintain it
for as long as necessary. I might mention that all of
this work up to now has been done by Firestone and
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 . paid by Firestone under oversight of the Department of
.2 Health Services.
3 The last thing I wanted to discuss is the
4 California Environmental Quality Act. As part of the
5 process of investigating cleaning up the site, we must
6 also make sure that we are complying with other state
7 laws. The California Environmental Quality Act is one
8 of those laws that, is applicable.
9 We have prepared a document known as an Initial
10 Study. And based on that study we-have determined
11 that the proposed cleanup will not have any
12 significant environmental impacts; therefore, we have
13 filed a proposed negative declaration and do not plan
14 on performing an environmental impact report. That is
15 also an item we are interested in receiving your
16 comments on. So we have proposed a negative
17 declaration for this site.
18 That is all I have to say. The speakers
19 following me will specifically discuss the Firestone
20 site and I will be available for additional questions
21 you might have. Thank you.
22 . SHIRLEY BUFORD: Thank you, Ric.
23 The next speaker is Doctor Alan Altenau from
24 Firestone, and he is the director of technology for
25 Firestone.
26 Doctor Altenau?
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 ALAN ALTENAU: Thank you very much and good
2 evening.
3 I would like to briefly discuss some of the
4 background of the site and a brief overview of the
5 work and progress that has gone on since environmental
6 investigations have begun back in 1983.
7 Firestone manufactured tires at the Salinas plant
8 from 1963 to 1980. The plant was closed in 1980, and
9 during the closure of the plant, equipment removal and
10 . so forth, environmental investigations were begun.
11 These investigations were begun in cooperation with
12 the Department of Health Services of California.
13 During these investigations we noted there was some
14 soil contamination and some contamination of the
15 groundwater.
16 In 1984, proceeding along with our
17 investigations, we moved to the off-site area as. we
18 were beginning to learn more about the on-site
19 contamination that existed. Also in 1984, as a result
20 of the 1983 investigations which indicated some soil
21 contamination, we removed over 5,000 cubic yards of
22 contaminated soil and disposed of that soil properly.
23 That really begun an approach that we followed
24 throughout this investigation and study as where we
25 . found contamination, we immediately took remedial
26 action to correct that problem rather than waiting for
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 all the investigations to be finished. So this was
2 the first piece of remedial action that we have
3 carried out by removing all the soil. We also removed
4 underground storage tanks and any contaminated soil
5 that might be associated with the removal of these
6 tanks.
7 In 1985, again as a result of some of the initial
8 investigation showing contaminated groundwater
9 on-site, we began construction of an on-site
10 groundwater extraction system and treatment plant. So.
11 as the water would start moving from on- tc off-site,
12 we could capture that contamination before it would
13 leave the site. So that construction was begun in
14 1985.
15 Now the chemicals that we showed as contaminants
16 in the soil and groundwater were several chlorinated
17 type of chemicals. These chemicals typically were
18 used — some of these chemicals were used in the
19 cleaning of equipment. So during that, small amounts
20 of spillage in the cleaning of equipment, some of
21 these chemicals got in the soil, went through the
22 soil, finally into some of the groundwater. Arc scir.e
23 of the chemicals really resulted from degradation,
24 - natural degradation of these chemicals in the soil to
25 other chemicals. So it wasn't chemicals used in the
26 manufacturing process, but small amounts of chemicals
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used to clean equipment, things like that.
In November of 1985 an extensive amount of crop
testing began. Various crops were tested to determine
whether there was any takeup of any of this
contamination during the irrigation process. The
results showed there was no chemical contamination in
any of these crops. The same kind of investigation
continued off and on over a period of time and further
verified there was no contamination present in these
crops.
In 1986, start of the treatment plant began,
again capturing contamination in the groundwater
before it would go off-site. This contamination that
we're extracting is what we call in the shallow
aquifer down to about 90 feet. When we use the term
"aquifer," that means different bodies of water in the
groundwater, and sometimes they are separated by clay
layers. And in the site here we have different
aquifer levels, maybe 100, 200, 300, 400 and so
forth. So we have investigated over time these
different aquifer levels, which are bodies of water
separated by impermeable clay layers. So this
extraction plan was extracting and cleaning water up
from the shallow aquifer, roughly 90 foot aquifer,
before it leaves the site.
In August of 1986 the Department of Health
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 Services approved an off-site deep g.roundwater
2 investigation plan. This was a plan designed to very
3 thoroughly investigate the off-site area — very far
4 off-site actually — to determine the extent of
5 contamination and to better define where the
6 contamination is. The results of this investigation
7 indicated that the contamination off-site is a rather
8 narrow band of contamination which we would call a
9 plume, but it's just an area where the contamination
10 exists. But it was not wide-spread, it was somewhat
11 . narrow. And the plan also indicated why it stayed
12 narrow due to the geological formations around the
13 area.
14 In 1987 we continued routine well sampling and
15 that showed no additional agricultural or municipal
16 wells with contamination. We continually monitor
17 various.wells. And this is just a note that 1987, at
18 that point since the investigations began in 1983, we
19 found no additional well contamination in the
20 agricultural or municipal wells. And I think part of
21 • that is the quick remedial action we have taken at the
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22 beginning in removing quite a bit of all the
23 contaminated soil as well as putting an on-site
24 extraction treatment plant functioning to reduce the
25 possibility of further contamination of going
26 off-site.
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 In April of 1987 DHS approved well locations for
2' the
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contamination at this site.
In December of 1988 we issued a very extensive
Remedial Investigation report, which is really a
compilation of all the analysis, results and
conclusions that took place over these years during
our investigations.
In June of this year the Department of Health
Services approved this Remedial Investigation report.
During the time they were reviewing this report we
were preparing a document called a draft feasibility
study. And this was a document really which follows
from the Remedial Investigation report, which by
looking at the results of this Remedial Investigation,
what would be appropriate alternatives for further
additional remedial action. And a number of
alternatives were listed and considered. And from
these potential alternatives for future remedial
action, a document, the Remedial Action Plan, would
follow which would be the selection of the most
appropriate alternative listed in the draft
feasibility report. .And tonight later on we will be
discussing the proposed Remedial Action Plan for
further action at this site.
In June of 1989 DHS announces a proposed final
cleanup plan which followed from the Feasibility Study
and is now part of the Remedial Action Plan, and that
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 was discussed in fact sheet number nine.
2 As mentioned previously, DBS proposed a negative
3 declaration for the Remedial Action Plan which says
4 that DBS does not see any environmental problems from
5 carrying out this Remedial Action Plan that is
6 proposed.
7 _June 27th, published notices for public meeting
8 and a comment period, which is one month. We're
9 having a public meeting today and the comment period
10 ends July 27th.
11 So that's a very brief overview of the work and
12 progress that has gone on over these last number of
13 years.
14 WALTER WONGs Doctor Altenau, I know this is the
15 wrong time, but I think it's important while you're
.16 there and before people leave to watch the Bill Cosby
17 Show at 8:00 o'clock, there is a question you need to
18 answer at this time because I have received quite a
19 few calls about it. Because apparently in the medias
20 it was reported that you found new contamination at a
21 deeper aquifer, and I wasn't aware of this because I
22 am of the understanding that levels have always been
23 below action levels. Can you clarify that now while
24 everybody is here?
25 ALAN ALTENAU: Would you put a couple of slides
26 back up, please?
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 We put an off-site extraction system in in
2 September of 1987 — this is again about a third of a
3 mile off-site in the 90-foot aquifer, shallow
4 aquifer. We put this extraction system in to stop
5 further contamination from going from that level to a
6 lower aquifer, namely the 120-foot aquifer. We knew
7 some had taken place. But we wanted to first put this
8 extraction system in to remove most of the
9 contamination in this level before putting extraction
10 wells in the 120-foot aquifer so we wouldn't draw down
11 the contamination in the 90-foot aquifer. We wanted
12 to do a substantial amount of cleanup and then install
13 extraction wells in the 120-foot aquifer, which is the
14 proposed plan. The amount of contamination in the
15 deep aquifers — 200, 300, 400, and 500 — have never
16 exceeded the state action level during all these
17 investigations. So due to the Remedial Action Plan
18 that we have had early on as well as continuing
19 throughout, the deep aquifers always had action levels
20 below the state action limit.
21 WALTER WONG: So it is not a problem?
22 ALAN ALTENAU: It is not a problem in the deep
23 aquifers and we continually monitor the deep aquifer.
24 If anything, we continually see it decline in values
25 in the deep aquifer, which one would expect because
26 the remedial action has taken place.
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 WALTER WONG: Okay. Fine.
2 SHIRLEY BUFORD:; Thank you. Doc-tor Altenau.
3 And with that I would like to introduce the
4 person, the gentleman who asked the question, Doctor
5 Walter Wong, who is representing you from the Monterey
6 County Health Department, and obviously he is very
7 concerned about this site. And.I would just like to
8 let you know who that was asking the question. Thank
9 you.
10 Next on our agenda is Chan Weisel, general
11 manager for the IT Corporation. And he will talk
12 . about the progress that's been made in the cleanup so
13 far.
14 CHAN WEISEL: Thank you, Shirley. And also,
15 welcome to our meeting this evening.
16 What I would like to do is simply give a little
17 more information on the progress that has been made/
18 the actual cleanup or remediation progress over the
19 last several years.
20 As Ric mentioned, we have been involved in what
21 is called interremedial measures, IRM's, which is
22 actual cleanup work done before all the investigation
23 is complete and before the final cleanup plans are
24 set.
25 Literally most of the cleanup has been
26 completed. As mentioned earlier, soil -- contaminated
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 soils and underground tanks have been removed, all
2 disposed at licensed hazardous waste facilities.
3 Doctor Altenau mentioned the various activities
4 giving the dates and all. What this figure will show
5 you is — well, it will simply put it in perspective
6 as to where things are.
7 This is the large building, the former Firestone
8 facility. And you see at the south end the treatment
9 plant which was installed in 1985 and operational in
10 early 1986. In that same time frame was the
11 installation of 15 water extraction wells, groundwater
12 extraction wells on-site. And they are along this
13 line.- They are piped all to the treatment plant, the
14 water is treated and then discharged to the Salinas
15 River.
16 The off-site extraction wells referred to earlier
17 are about a third of a mile away from the plant or the
18 property line. And there are five of them and these
19' were installed in 1987 and operational just about two
20 years ago. The water from these wells is pumped
21 through a pipeline along the farm roads to the
22 treatment plant.
23 The groundwater plume referred to is a narrow
24 band of contamination starting essentially in the
25 middle of these on-site of this on-site well area or
26 at least that's where the highest concentrations exist
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 and moving in this direction, and this is in the
2 shallow aquifer, the uppermost aquife-r about 90 feet.
3 down. So it's this narrow band of contamination
4 moving in the shallow aquifer that all of our work,
5 all of our groundwater work has been intended to
6 remove — remove the contaminants from.
7 Later you will see slides which will show the
8 next and we believe final phase of work which will be
9 extraction in the 120-foot layer. And again as Doctor
10 Altenau mentioned, there is no significant
11 contamination in the deeper aquifers and therefore no
12 remediation plan.
13 What I would like to show you now are three
14 contamination concentration curves which I think
15 dramatically shows the progress and the
16 accomplishments of the cleanup to date. I showed you
17 the line of 15 on-site extraction wells. This first
18 curve is an average of the extremes of that line, the
19 uppermost wells and the lowermost wells. And as you
20 can see, three years ago concentration average was
21 about three parts per billion. Most recently we're
22 down to .under one part per billion. The action level
23 — drinking water action level is six parts per
24 billion so we're well below that. So that is, we
25 , feel, a real accomplishment. These concentrations by
26 the way are for DCE, one of the chemical contaminants
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and the main one that we have tracked.
Same kind of curve here, but for the center of
the plume or where the center of the on-site
extraction wells are. And here, instead of starting
at 30 parts per billion, we were over 400 parts per
billion and have brought that down to five. So that's
essentially a hundred fold decrease. You can see why
I am saying that the bulk of the cleanup has been
completed. Again the action level is six, so we're
below the action level in the on-site area.
Last concentration curve for the off-site
extraction wells which were started up in 1987, the
average concentration at that time was about 65 parts
per billion, currently running about 16. So we're
still slightly above the action level, but coming down
nicely.
I think this final slide on the accomplishments
summarizes well. It shows the actual area of the
contaminant plume in the groundwater at different
periods of time.
Again here is the former Firestone facility, the
line of on-site extraction wells along here and the
off-site extraction wells shown here. This is the
plume area at six parts per billion or the action
level for each of the years 1986, '87, '88, and '89.
And as you can see in 1986 the area was quite
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large covering all of the area- of the on-sl-te
extraction' wells* One-year, later after- the treatment*
plan had operated for a year, major reduction in plume
area. The next year 1988, even a greater reduction.
In 1989 so far, this is the area. That's about an 85
percent reduction in plume area during that three-year
period.- So we feel that a lot of the remediation
again has been completed and we're well on the way.
You can see here I talked about the narrow plume. You
can see how narrow that is at this time.
Thank you, Shirley.
SHIRLEY BUFORD: Thank you.
Next on our agenda, we'll present Doctor Nick
Hazelwood, senior technical specialist and group
manager for IT Corporation and he will talk to you
about risk assessment at the Firestone facility.
NICK HAZELWOOD: Thank you very much, Shirley.
I hope you can all hear me. If you can't put your
hands up.
When we talk about risk assessment there are two
things you have to keep in mind. First of all, the
only tim-? you have a risk is when there is both a
hazard, the presence of a hazardous material or a
hazardous situation and someone is exposed to it. If
you have a hazardous material and no one is exposed to
it, there is no risk until that exposure happens. So
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 when we analyze risk assessment, we both analyze for
2 hazards and for possible exposures.
3 In identifying the hazards at this facility we
4 looked for the types of chemicals that are present in
5 the soil and the groundwater and looked at the effects
6 or potential effects on human health and/or the
7 environment.
8 These are the chemicals that are the indicator
9 chemicals that were found at the site, and we talked
10 about chlorinated solvents and aromatic solvents that
11 were used. 1,1 DCE, which is this one here, 1,1
12 dichloroethene, also known as vanilladene chloride as
13 a compound, is actually a degradation product of 1,1,1
14 trichloroethane, which is the principal solvent that
15 was used. When this material gets in the soil and
16 water it is broken down frorc natural processes to this
17 compound. This is the compound that is present in the
18 highest concentration and is what we use as our
19 indicator. That's why all of our graphs are shewing
20 1,1 DCE. The other compounds are there, they are
21 there in lower concentrations. So this is the easiest
22 one to track and this is the one we're working on to
23 reduce to accepted levels. Next slide, please.
24 When we look at exposures, we look both at the
25 media that could be delivering the substance -- air,
26 drinking water, irrigation water and soil on the one
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 hand — and the routes of exposure — inhalation,
2r ingestion or skin contact.
j
3 Out of all those possible combinations of 12 or i
4 so, these were the three that we isolated as being the j
• i
5 possible routes or pathways that could lead to risk. j
6 Obviously drinking the drinking water contaminated j
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7 with the substances that were found. j
8 Second, air emissions from the treatment plant, i
9 because there is an air stripper in there, or from j
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10 water used for irrigation and evaporation of these |
11 chemicals from the irrigation water. Analysis cf this
12 showed that the concentrations in air were well below ;
13 the accepted levels as set by regulatory agencies for
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14 air emissions from both DHS and the Monterey Unified :
15 Air Pollution Control District requirements. ;
16 Crop uptake, as Doctor Altenau told you, has beer.
17 studied extensively. There is no data to show that
18 there is any uptake by these chemicals by the crops
19 grown in the crops in the field using the irrigation
20 water. So we can basically "X" out these two. They
21 are potential, but not actual pathways. So our
22 analysis and risk assessment has focused on the
23 dr.inking water issue. Next slide, please.
24 The risk criteria that are laid down for our
25 cleanup is that substances that are carcinogens that
26 could cause cancer, that the amount in the drinking :
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 water must be small enough so that the lifetime
2 additional risk from drinking that water for 70 years
3 would be less than one in a million additional
4 possibility of getting cancer.
5 Similarly for non-carcinogens, we calculate
6 something called a health index. Now the health index
7 takes the state action level, which as several people
8 have mentioned for DCE is six parts per billion and
9 says you divide the actual concentration by the number
10 that is the action level and that number must be less
11 than one. The action level, in other words, tells you
12 what is the permissible concentration in drinking
13 water that you could ingest without harm for
14 non-carcinogens. And the sum of all of those things
15 must be less than one. In other words, the
16 concentration of all the non-carcinogens must be small
17 enough so that there is no long-term adverse health
18 effect from this water. Next slide, please.
19 We looked at different possibilities for drinking
20 water. There is only one well in this area that is
21 used for domestic purposes. So we said •— let us take
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22 some worse case situations. We will take a
23 hypothetical well in the shallow aquifer, similarly
24 one in the intermediate zone and one in the deep zone,
25 and take the average concentration in each one of
26 those and is there a potential health risk.
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 And this next slide summarizes the findings of
2 the risk assessment. There is.no potential health:
3 risk in the existing well if someone were to put a
4 well in the shallow aquifer. And as Walter Wong will
5 tell you, the County does not allow that kind of thing
6 for a lot of reasons. But if it were done there would
7 be a slight risk, which is of course one of the
8 reasons*why we're going and cleaning it up. Similarly
9 the hypothetical intermediate and deep zone wells,
10 again with the average concentrations, there is no
11 potential health risk. Go ahead.
12 So the risk assessment conclusions, and this is
13 quoted from the risk assessment, there is no present
14 or future threat to public health. There is no
15 present threat because our analysis shows no one is
16 exposed. There is no future threat because there is a
17 cleanup plan which is going to be discussed by
18 subsequent speakers that will remove the last residue
19 of the hazardous material so that there will be no
20 future threat to public health.
21 . SHIRLEY BUFORD: Thank you. Doctor Hazel wood.
22 Our last speaker on the agenda is Le.onard Allen
23 and he will speak to you about the proposed Remedial
24 Action Plan.
25 Mr. Allen?
26 LEONARD ALLEN: Good evening, ladies and
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 gentlemen.
2 My purpose this evening is to present the
3 Department of Health Services proposed plan for you so
4 you can see what the next stage will be so that you
5 will have your opportunity to comment on that, get
6 your input into the State.
7 The first speaker this evening, Ric Notini,
8 covered the State procedures for evaluating a site
9 such as the Firestone site and getting to the stage of
10 having the proposed plan and actually implementing
11 that through cleanup.
12 We can have the first view graph there, George.
13 The proposed plan that I will be covering tonight
14 comes out of that portion of the process that Ric
15 covered called the Feasibility Study. The Feasibility
16 Study is really a very detailed engineering study that
17 considers a wide variety of alternatives aimed toward
18 cleaning up the contamination that has been found.
19 And out of that Feasibility Study we select the best
20 remediation alternative.
21 The proposed plan is based, to a large degree, on
22 the Remedial Investigation report that was prepared in
23 • December of '88. That report has, as Doctor Altenau
24 has mentioned, combined all the previous studies of
25 the site, defined this plume or where the chemicals
26 occurred in the groundwater. We have got this narrow
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 region that looks like a cigar on one of the earlier
2 slides. It's not spread out laterally quite a bit;
3 it's fairly confined in there. Once we've got that
4 area defined, then we can look at the remediation plan
5 to cleanup that zone of chemicals in the groundwater.
6 Earlier also we have discussed that the soils on the
7 site that were contaminated were removed. So the
8 proposed plan that we're discussing this evening is
9 . focused just on the cleanup of the grcundwater which
10 is left.
11 The Feasibility Study that was done for this site
« •
12 followed the very formalized, detailed Department of
13 Health Services guidelines as well as the
14 Environmental Protection Agency guidelines. The large
15 variety of remediation schemes that were considered
16 for the treatment, included a number of chemical,
•
17 physical and biological processes.
18 We have also looked at other types of treatments
19 such as a containment, if there is some way to contain
20 the contamination where it was, concluded that pumping
21 the groundwater out and treating it was the best
22 alternative.
23 We can see the next view graph then. Once we
24 have gotten to the point where we have selected 3 PLLT.O
25 and treat alternative, then we have to look at the
26 locations of the extraction wells. What wells are we
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going to pump from? Both horizontally, where are we
going to locate the wells .and what depths are we going
to be pumping from?
It has been mentioned that there are 15 existing
extraction wells on-site and there are five existing
extraction wells off-site, all of those located in a
zone shallower than 90 feet.
In addition, during the Feasibility Study we
considered ten new well locations that would install
wells down to the zone 120 feet deep. With those
wells, all the existing and the proposed — or the ten
new wells that w.ere evaluated, then we have the
alternatives of adjusting the pumping rates to come up
with the combined flow rate from the groundwater
that's being extracted.
If that goes back to our treatment plant, then we
have a variety of treatment alternatives. As we
mentioned, we considered a large number of physical,
chemical and biological treatment options for the lew
concentrations; that is concentrations in the parts
per billion range that we're dealing with here at
Firestone and the chlorinated hydrocarbons and
aromatic hydrocarbons that are present at these low
concentrations.
The Feasibility Study and the cleaning process
leads us to the viable treatment options of being
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carbon absorption*, the air stripping, and the other
one being a combination of those two. Tfiat is what's
been going on at the treatment plant for the last
several years.
The other options that were considered were the
options for how we discharged the treated water; that
is, once the groundwater has been extracted and has
gone through the treatment plant, what do we do with
the water after it has been cleaned? We did consider
three alternatives here. One was continuing the
discharge into the Salinas River about a mile south of
the treatment plant. This has gone on for the last
three years. We considered injection of the treated
water through wells located on-site. And we also
considered disposal of the treated water into surface
ponds just south of the plant area. The screening
process that we went through led us to stay with the
discharge to the Salinas River.
Looking at the combinations of the well locations
and the pumping rates with these treatment options and
the discharge options led us to define five
alternatives that were studied then in greater
detail.
The first alternative is called a "no action
alternative." And for the Firestone site that would
involve stopping what is going on right now, taking no
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 further -treatment action. That is — that's required
2 by regulations and is more to establish a baseline
3 case for comparison with the other alternatives.
4 For alternative B, we looked at continuing the
5 existing pumping and treating system; that is, pumping
6 from the existing wells at a combined flow rate up to
7 650 gallons a minute. That's only pumping from the
8 shallow aquifer.
9 In fact, we have two limitations on the flow rate
10 that we can treat under the current conditions. The
11 650-gallon-a-minute treatment of the water is limited
12 by the current capacity of the treatment plant.
13 Actually with the pumping from the contaminated wells
14 that we're doing right now and the declining
15 groundwater table in this area, we can only pump about
16 450 gallons a minute from the existing wells.
17 The third alternative that we looked at showed
18 that we would — if we put in five new wells in the
19 intermediate aquifer a little farther northwest of the
20 plant from the five off-site wells that exist now and
21 we pump those in combination with the current pujrpir.c
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22 from the shallower wells, we could pump at a combined
23 rate of about 1150 gallons a minute. This does
24 involve the five new wells to be constructed in the
25 intermediate aquifer, it would also include an
4
26 expansion of the existing treatment plant.
•8
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 ' However, recognizing that is using almost double
2 the pumping rate that we have been using in the past;
3 when you use that much additional water we looked at
4 the fourth alternative, which is similar to the third
5 except that we adjust the flow rate so that the
6 combined flow rate from all the wells, including the
7 five new wells, does hot exceed the 650 gallons per
8 minute. That, in fact, is the alternative that has
9 been selected by DHS for the proposed plan.
10 The fifth alternative, similar to the fourth,
11 only that two additional wells would be installed in
12 the intermediate aquifer, was that we would have fewer
13 wells. We have recognized that by looking at a lower
14 combined treatment flow of 600 gallons per minute for
15 that.
16 Okay. These five alternatives were analyzed in
17 detail and discussed in the feasibility study. There
18 are nine evaluation criteria that are included in the
19 EPA guidelines and used by Department of Health
20 Services also.
21 We have broken up the evaluation criteria into
22 four that we call the key criteria and five other
23 criteria. Now these are not listed in terms of
24 priority. Certainly if we were including priority,
25 the overall protection of the human health and the
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26 environment would be high on the list rather than down
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 under the other criteria.
2 The differentiation'between the key criteria and
3 the other are that the key criteria are the ones that
4 help us differentiate more among the five alternatives
5 that were studied in detail.
6 The first criteria, short-term effectiveness,
7 lets us evaluate how effective the proposed
8 alternative would be in a relatively short period of
9 time.
10 Long-term effectiveness, on the other hand, is
11 other than given enough time, how effective would the
12 remediation be for each of the five alternatives?
13 The third key criteria was the one that US EPA
14 calls a reduction of toxicity, mobility and volume.
15 That's getting into the question of the permanence,
16 how permanent is the proposed remediation?
17 The fourth key criteria is whether the proposed
18 alternative complies with all the regulatory
19 guidelines involved.
20 The other items, just to run through them briefly
21 here since they don't help us differentiate greatly
22 between the alternatives, are the impiementability;
23 that is, is there sufficient technology? Is there
24 equipment? Is there manpower to actually implement
25 the proposed remediation?
26 The sixth criteria would be the cost
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 effectiveness of the remediation.
2 The seventh, the overall protection of human
3 health and the environment, would be either State
4 acceptance and/or EPA concurrence with the plan.
5 And finally, the community acceptance, that's one
6 of the purposes of the meeting this evening is to
7 present the plan to the community and get the feedback
8 from the community on how acceptable that plan is.
9 When we apply these nine evaluation criteria to the
10 five alternatives, we came up with the matrix that
11 shows how these work.
12 If we look in terms of the first criteria, the
13 short-term benefits, the first two — no action and
14 continuing the current operations — do not do
15 anything to remediate the chemicals in the groundwater
16 in the 120-foot level. So they really don't achieve
17 the short-term effectiveness. So we put "no".on
18 there.
19 If we put in the five new wells, in the case of
20 alternative C and D, pumping either 1150 gallons a
21 minute or 650 gallons a minute, we have put "yes" in
22 here. We do achieve the short-term effectiveness.
23 If we cut back to only two new wells, as in
24 alternative E, we again have "no" for the short-terrr,
25 benefit. It takes us longer to achieve the cleanup
26 levels with those.
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS •
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1 So looking just in terms of the short-term
2 benefit criteria, there are only alternative C and D
3 that satisfy that criteria. The shaded zone D there,
4 of course, is the proposed plan that is being
5 presented to you this evening.
•
6 In terms of long-term benefits, the no action
7 alternative would take a long time because there is no
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8 active remediation undertaken for that alternative.
9 Given enough time — that is, the long-term benefits
10 — all the other options do eventually achieve a
11 long-term benefit.
12 Looking in terms of the reduction of toxicity,
13 mobility and volume, we achieve it with the last three
14 on the list here. We achieve it only in the shallow
15 aquifer for alternative G and we do not achieve it in
16 the terms of the no action alternative or alternative
17 A.
18 Under the regulatory compliance evaluation
19 criteria we did not comply with the regulations in
20 case of the no action alternative, we do in the case
21 of the other four; although in the case of C there
22 . would be some permit chang.es required to implement
23 that.
24 So looking at the comparison of these
25 alternatives we see that alternative D, the proposed
26 plan, is the only one that satisfies each of these
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 four key criteria as we go along here. Again, only
2 alternative C and D on here achieve the short-term^
3 benefits.
4 So if we look at the differences now between C
5 and D on here, we see that actually — even though we
6 pump almost twice as much, in the case of C we're
7 pumping 1150 gallons a minute compared to 650 gallons
«
8 a minute.
9 The time for the cleanup is really not that much
10 different. We're controlled more by the cleanup in
11 the 120-foot level than we are by the cleanup in the
12 90-foot level. And the time,for the cleanup in the
13 120-foot level is essentially the same for alternative
14 C and D. So we have the same time, the cost obviously
15 is higher with the alternative C because it would
16 involve expansion of the treatment plants, some
17 additional capital costs, also time involved to
18 achieve the new permits that would be required.
19 One of the other major differences between
20 alternative C and D is that alternative C, which was
21 not selected, would take twice the amount of pumping.
22 So if there is an impact on the agricultural use of
23 the water, it would be greater with C, which again
24 leads us to alternative D as the selection.
25 D was selected as the final proposed cleanup plan
26 because it achieves the rapid cost-effective cleanup
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 and requires less groundwater to be pumped than
2 alternative C, which is the only other alternative
3 that achieves the short-term benefits criteria. We
4 have a map here that shows the proposed five new
5 wells.
6 As I mentioned earlier, we actually considered a
7 total of ten different locations in the off-site area
8 for wells in the intermediate aquifer. These are the
9 five that we have selected and are included in the
10 proposed plan — three of them are located along
11 Alisal Slough and two of them are located on existing
12 farm roads. We have done this to minimize any impact
13 on the agricultural activities out in that area.
14 Those five pipelines — the five new proposed
15 wells would be connected by a pipeline that would run
16 along Alisal Slough and along Scarp Road and tie into
17 the existing pipeline back about a third of a mile
18 away from the existing treatment plant;
19 To summarize the proposed plan, we would plan to
20 continue pumping from the existing shallow aquifer
21 wells, although the pumping rates from the various
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22 wells would be adjusted depending on how the
23 monitoring data came in. In addition, the five new
24 wells would be Installed in the intermediate aquifer.
25 The plan right now would be to have those wells
26 installed this fall. We would pump at a combined flow
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
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1 r'ate up to 650 gallons a minute: from all the wells,
2 both the shallow and-the intermediate aquifer wells.
3 What we're accomplishing by this is that we will
4 — we lose the contamination in the intermediate
5 aquifer and continue to reduce the contamination in
6 the shallow aquifer as we have been for the last three
7 years-or so. We are also cutting off any migration of
8 the chemicals from the 120-foot aquifer into the
9 deeper aquifers. The treatment plant would continue
10 operating as it has been for the last several years;
11 that is, we would still be using the carbon absorption
12 and air stripping units on the site. The discharge
13 would continue to go into the Salinas River as it has
14 been going.
15 By putting in the five new wells in the
16 intermediate aquifer, our computer simulations project
17 that we will significantly reduce the remaining
18 cleanup time. We're projecting that the cleanup time
19 .will be about a year to a year and a half from the
20 time that the wells and the 120-foot aquifer are
21 installed. We have run over a hundred computer
22 simulations in various combinations of well locations,
23 pumping rates, projected the cleanup times.
24 Some of the alternatives, basically the five that
25 we have discussed in detail here, are shown on the
26 plots across the wall, if you would care to take a
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look at those during the break here prior to the
question and answer period.
In addition, we do have several other maps, if
you would like to take a look at those, those will be
spread out on the table up in the front during the
break period here.
Shirley?
SHIRLEY BUFORD: Thank you, Mr. Allen.
Okay. I think that's a lot of information to
digest. We would like to take a few minutes to break
so you can look at the other information .and be ready
for the question and answer period. So we'll take ten
minutes and get into the question and answers.
(Break taken from 8:22 to 8:33 p.m.)
SHIRLEY BUFORD: Thank you very much. We'd like
to get started on the second part of the program,- the
question and answer session.
We have got a number of agency representatives
here, other than those who were making presentations
tonight. And I have already introduced Walter Wong.
Doctor Wong is sitting in the front. He represents
the County Health Department — Monterey County Health
Department. Also we have got Bob Baldridge who
represents the Water Quality Control Board - Central
Coast. That is Mr. Baldridge. And Jeff Dhont from
the Environmental Protection Agency. Jeff is up at
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
-------
1 the table. And you have met the other presenters, so
2 we'd like to get started.
3 I would like to ask you to stand if you have a
4 question and give your name, identify yourself. And
5 if you want to ask a question of a specific person,
6. please indicate that, otherwise we will get the answer
7 for you.
8 So I would like to open the process now. Are
9 there any questions?
10 ED FISHKIN: I have a question. There seems to
11 be a very well thought out —
12 SHIRLEY BUFORD: Okay. Give us your name, sir.
13 Please state your name.
14 ED FISHKIN: Ed Fishkin.
15 It seems to be a very well thought out mediation
16 plan. Assuming that the computer projections are
17 correct, in a year and a half from now all of the
18 contamination levels are below the action level. How
19 much longer would you continue to pump and how much
20 longer would you continue to sample to make sure that
21 the water is indeed clean?
22 SHIRLEY BUFORD: Thank you.
23 Mr. Allen, would you like to answer that?
24 LEONARD ALLEN: At the point where the
25 concentrations in the groundwater have reached the
26 cleanup levels, we would stop the pumping at that
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
-------
1 stage. The monitoring beyond that to see that there
2 is no unusual buildup in the concentrations past that,
3 we're anticipating now would take place for at least
4 an additional two years.
5 ED FISHKIN: Thank you.
6 SHIRLEY BUFORD: Thank you.
7 Okay. The gentleman in the red. Would you like
8 to stand and tell us who you are?
9 JIM LAND: My name is Jim Land from Carmel
10 Valley. I was wondering, it seems to be apparent that
11 the flow rate is something of a concern because of
12 somewhat of a depletion of the aquifers. I was
13 wondering why the water isn't injected back into the
14 aquifer rather than dumped into the Salinas River.
15 And I have a second question too.
16- SHIRLEY BUFORD: Okay. Mr. Allen, will answer
17 your first question.
18 LEONARD ALLEN: That's a very good question. In
19 effect, we are recharging the water with the discharge
20 to the Salinas River. The river bed is porous enough
21 that the water that we're discharging does permeate
22 back into the shallow aquifer system. In fact, the
23 flow monitoring system that the Federal Government
24 monitors downstream from us shows a lower flow rate
25 than we're actually pumping into the river at the
26 discharge.
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
-------
1 So we are doing it,, we 're/ achiev ing; the injection
2 into the shallow aquifer system without the problems
3 that inherent in injecting it through wells on-site.
4 With wells on-site you have problems with siltation,
5 you are not able to maintain the pumping into those
i
i
6 injection wells. I
i
7 SHIRLEY BUFORD: And you had a second part to j
8 your question, sir?
9 JIM LAND: Yeah. With all the available
10 technologies of water cleanup possible, why was carbon
11 absorption the chosen method here?
12 LEONARD ALLEN: The carbon absorption and the
13 air stripping do turn out to be the most effective.
14 You are limited with a lot of the other technologies
15 because of the very low concentrations that we have in
16 the waters to start with.
17 We're down in the parts per billion range. A lot
18 of the technologies would not be effective in there.
19 I'm not sure what other alternatives you are
20 considering here, but there are other limitations with
21 the other ones if you are looking at soire biological
22 •'• treatments you have problems treating the chlorinateds
23 at this low level. In fact with the biological
24 treatments you have to have enough of the nutrients to
25, keep the bugs alive, and we just don't have those high
26 concentrations here.
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
-------
1 We did look at probably 30 or 40 different
2 alternatives. But for the chlorinated hydrocarbons
3 and the aromatic carbons and activated carbon and the
4 air stripping are the most efficient way to go.
5 JIM LAND: Thank you.
6 JOHN GOODRICH: Back to the original question.
7 Any idea of what the re-absorption is of the water you
8 pump out? You're saying it gets re-absorbed back into
9 the aquifer; any idea what percentage?
10 LEONARD ALLEN: Well, it depends on how far
11 downstream it goes. Eventually all of it is. The
12 Salinas River is recharging the shallow aquifer in
13 this area, so it's getting back in there. Quite a
14 high percentage of it is getting back in.
15 SHIRLEY BUFORD: Can I get your name, sir?
16 JOHN GOODRICH: John Goodrich.
17 SHIRLEY BUFORD: Pardon me?
18 JOHN GOODRICH: John Goodrich.
19 SHIRLEY BUFORD: Goodrich. Thank you.
20 Anymore questions?
21 JIM ABELOE: Yes. My name is Jim Abeloe. I am
22 interested in the 120-foot aquifer and the extent of
23 contamination in the aquifer and the amount of the
24 degree of contamination. The upper aquifer plume has
25 been well-identified both in concentration and extent,
26 and I would like to have that same information for the
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
-------
1 120-foot aquifer.
2 SHIRLEY BUFORD: For the 120-foot aquifer you
3 would like to know the contamination plan?
4 JIM ABELOE: Yeah. Whether you contemplate
5 putting the plan in or something like that.
6 SHIRLEY BUFORD: Okay. Mr. Allen?
7 LEONARD ALLEN: Yes. There is a map in the"
8 feasibility study, which we-have a copy of here if you
9 would like to take a look at it. It shows the plume
10 in the intermediate aquifer. That is similar to the
11 shallow aquifer in that it's confined laterally.
12 These are old alluvial sand and., gravel channels that
13 are filled in that the chemicals are going down
14 basically. It's approximately the sarce width as the
15 plume that we have in the shallow aquifer. The
16 concentrations of DCE, as I recall, are about 15 tc 20
17 on an average in that area —
18 NICK HAZELWOOD: Maximum.
19 LEONARD ALLEN: — maximum values for those. The
20 plume starts out just west of where the off-site
21 extraction wells are now and extends out to where the
22 120-foot aquifer emerges with the 200-foot aquifer.
23 It was about 250 feet, as I recall, something like
24 that out.
25 SHIRLEY BUFORD: Thank you. Does that answer
26 your question, sir?
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
-------
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
IS
19
20
21
22
23
24
25
•26
JIM ABELOE: Yes, sir.
SHIRLEY BUFORD: Thank you.
Are there any any additional questions?
As Mr. Allen just stated, he's got a copy of the
Feasibility Study and other reports here tonight, but
they are also located at the information repository at
the John Steinbeck Library, including the other
community relations materials that have been
generated, nine fact sheets and other information that
was generated on the Firestone facility. You are
welcome to review that material there.
And again, please call us. Any of the presenters
that you heard tonight from the Department of Health
Services, Firestone, IT, Doctor Wong, the Water
Quality Control Board/ we're all here to help you and
to give information to you about the site.
I would like to thank you for coning out tonight
and sitting through the presentations. And please
feel free to come and talk to any of the people here.
If you have no more questions, we will adjourn the
meeting. Thank you.
(Hearing concluded at 8:42 p.m.)
SUSAN D. KUCHER, CERTIFIED SHORTHAND REPORTERS
-------
TABLES
-------
TABLES
-------
TABLE 2-1
POTENTIAL FUJERAI APPLICABLE OR RELEVANT AN) APPROPRIATE NEqUIREKXTS (ARMS)
RtgUIHLKNTS
TYPt1
SWWRV
ADMINISTERING
AGEfO
Resource Conservation and Recovery Act
(RCRA) as aieuled by Ibiardous and Solid
Uaste AimJitnls (I6W/U
(42 USCA 7401-7642)
(40 CfK 260-2UI)
Ground Water Protect ion
(40 CM 264.90) and monitoring
(40 CFR 264.97)
Safe Drinking Hater Act (STNA)
[42 USC 300(f)]
Haxinun Contaminant Levels (HCLs)
400* 141.11-141.16
underground Injection Control Relations
(40 CFR Parts 144, 145. 146. aivl 147)
ROM-related regulations are generally action specific. EPA office of
However, RCRA provides Haxiiiun Concentration Limits (RCRA M3Ls) solid waste.
as part of ground-water protection standards (40 CFR 264.94).
ROM His are given for fewer chemicals than the SDUA. although
the SIM* Mils are the basis for RCRA HCLs when regulated.
Hazardous constituents entering ground water oust not exceed EPA office of
concentration limits in the aquifer underlying the waste management solid waste.
area. The ground-water nun it or ing program mist provide a reliable
indication of ground-water quality be lew the waste management area.
Establishes drinking water standards for all sources OHS
of public drinking water. California Department of Health Services
(W6) is the primary agency for airiinistration of the STJWA in the state.
See state section. Table 2.
Applicable HCLs are based on Haxinun Contaminant Level Goals (Mate). DHS in California
best available technology, best treatment techniques, and cost.
Potentially applicable for alternatives utilizing a ground- 016 in California.
water injection option.
FIR:0067-Rr
DATE: 8/22/89
PIMM
-------
TABLE 2-1
POTENTIAL FEDERAL APPLICAOI OR RELEVANT AM) APPROPRIATE REqUlRDCNTS (ARABS)
(Contirued)
HtqUIRMNTS
TYPE
SUHWY
AEN1N1STERING
AfiENCY
Occupational Sdfety and Health Act
(19 OK 1910)
Executive Order 11988 related to
floodplain management 40 CFR 264 an*
Executive Order 11990 related to
Protection of wetlands. 40 CfR Part 6.
A
Establishes general safety procedures in the work place. Installed CAL-OSIIA
c^iipntKTt (lakes it necessary for workers to be engaged in routine
activities at the site. Markers may be exposed to dilute organic
coritdninants fran air stripper off gas. OS!(A Markers exposure
levels and general construction safety standards should be considered.
OSm Pennissable Exposure Level (PEL) requiranents under 19 CFR 1910.120
are applicable to worker exposures during response actions at CERCLA sites,
except in states that enforce equivalent or more stringent requirements.
California has reinstated a program for nongovemient employee work place
exposures with equivalent or more stringent requirements. See discussion
in state section.
The current WOES permitted discharge structure is located in the flood-
plain and wetlands of the Salinas River. This discharge structure and
potential future new structures should avoid adverse effects, minimize
potential harm, and preserve resource values in floodplain and wetlands.
RUTXB in California
Type of ARAK: C-contamtnanl specific. I-location specific, A-action specific.
GOV.006/-HT
DATE: 8/22/t
FINAI REVISION
-------
TABLE 2-1
POTENTIAL FEDERAL APPLICABLE OR RELEVANT wo APPHCPRIATE REquuocHrs (ARMS)
(Continued)
REOUIkEKNTS
TYPE
ADMINISTERING
ACENCV
Clean Water Act (CWA) 33 USCA lftl-1376
40 CFR 1GO-H9
National Pollutant Discharge Elimination
Systan (HUES) (40 CFR 122-125)
Water Quality Standards fCWA US (a)(l)]
Clean Air Act (CAA) (42 USCA 7401-7642) A
(40 OH 50-49)
National Emission Standard for A
lla/aruous Air Pollutants (40 CfR 50-69)
Ihe Clean Water Act retires permitting of effluent discharges RlflCB in California
under the WOES permit program and seeks to protect the existing and
attainable uses of waters of the U.S.
Ml)fS permits contain applicable standards, monitoring requirenents, RUEjCB in California
and standard and special conditions for water discharges. Both co-site
and off-site discharges from CERCLA sites to surface waters are required
to meet the substantive CUA requirements, including discharge limitations,
monitoring requirements, and best managanent practices. Oily off-site
CEKCLA discharge oust be permitted. The facility possesses an NPDES
pennit for discharge to the Salinas River.
Effluent limitations are required to achieve all appropriate State water Administered by EPA
quality standards. EPA "Policy for the Development of Mater Quality- Office of Water.
Based Pennit Limitations for Toxic Pollutants" (49 FR 9016, March 9g 1984)
states that toxic pollutants contained in direct discharges may be con-
trolled beyond Best Control Technology/Best Available Technology (BCT/BAT)
equivalents to meet applicable State water quality standards.
The Clean Air Act (CAA) is implemented through State programs CARS and M3UAPCD
of the California Air Resources Board (CARB). CARB gives enforxanent See state section.
authority to local air quality managanent districts. The Monterey Bay
Unified Air Pollution Control District (MBUAPCO) enforces air quality for
facilities in this area. Activities resulting in emission require a'
pennit to operate with corresponding effluent requiranents as for the
existing air stripper.
national Emission Standards for Hazardous Air Pollutants (NESJWP) CARB and rCUAPCD
are process and industry specific and were praajlgated to protect
people and the enviroment. NESIIAP standards are currently limited
to very few chemicals (40 CFR 61). Benzene is discussed under NESlMPs;
luwver. no anission standards are described (40 CFR 61.110-112).
-fin*. ;_p i
DATE: 8/22/89
FINAL, REVISION
-------
lAfflf 2-2
POTENTIAL STATE APPLICABLE 0) RELEVANT AH) APPROPRIATE REqUIREMXIS (ARARS)
(Continual)
KKjUIRLRNTS
TYPl
SWWfl
ABMNISTERING
AGEtCY
California Environnental Quality Act
Public Resources Code. Division 13
Occupational li'dllh and Safety Act,
Labor Code, Sectim 6JUO el seq.~
Chapter 6.6 Safe Drinking U.
-------
TABLE 2-*
POTENTIAL STATE APPLICABLE OR RELEVANT AM) APPROPRIATE Snj/IROtKTS (/WARS)
(Contirued)
REgUIRQCNTS
TYll
SIMWY
ADMINISTERING
AGENCY
Regulation XII - New Source Review
Ptup Test Permit
State Drifting Wrter Act (SDWA).
Health and Safety Code. Division 7.
Part 1, Chapter 7, Section 4010 et seq.
California Code of Reflations,
Title 22, Division 4, Chapter 15,
Dunestic Udter Quality aid Hmitoriny
Porter-Coloyne teter Quality Act
Water CuJe, Division 7, Section 1XII)
et seq., CCH litle 23, Chapter 3,
SutKhdpter 9 ani Subchapter 15. K60-2836
This reflation sets forth preconstruction review requirements for new M3UAPCD
or modified stationary sources, to ensure that the operation of such
stationary sources does not interfere with progress in attafrment of the
national ambient air quality standards, without unnecessarily restricting
the future economic growth .within the district. NAAQS guidelines and total
anissions limits are on a case-by-case basis.
Required for withdrawal and discharge of volatile contaminated ground water M3UAPCD
atmospheric release of contaminants is possible.
SDWA establishes drinking water standards for sources of public
drinking water. Federal MCLs are incorporated intd State regula-
tions regulations, and in sane cases the State may proiulgate more
stringent State MCLs. The DIB has promulgated His for 12 organics
and 2 inorganics in drinking water. Several of the proposed KLs
are the sane as or more stringent than the current nonprcnulgatad
DtIS ALs. Under SUM, as amended by "AB 1803," sanpling and analysis
of drinking water sources are required. upon review of the results
of initial sampling, a monitoring program is established by OHS.
In the event of violation of DIG action levels for drinking water,
public notification may be required.
Similar to the Federal CUA, the Act and its associated regulations
apply to protection of waters of the State. An MTJES permit is
required for off-site discharges, whereas, only substantive
requirements are required for on-site discharges. Porter-Cologne
delegates standard setting authority to the RUQCBs. RUQCB will not
dictate specific treatment alternatives but will require that the
alternative meet mininun action levels and perform at a level near
the Rest Available Technology (BAT) for the chosen alternative.
The WJXb is responsible for establishing WOtS substantive and
administrative requirsnents for permitting at levels sufficiently
protective of the waters of the State. RtJJCB emission standards
are set on a case-by-case basis and apply to treated wastewater.
storm water runoff, etc. Waste dischShje reports and requirements
are also specified.
DHS is responsi-
ble for adninistering
the State SUM, which
includes the "Afl 1803"
monitoring program.
RWQCB
OOV:006/-RF
DATE: 8/22/89
RFVISION
-------
f/ttLE 2-2
POTENTIAL STATE APPLICABLE OR RELEVANT MO APPROPRIATE RETJJ1RLHENTS (MURS)
(Continued)
KEqulKERHTS
TYPE
SuWWY
ADMINISTERING
AGENCY
Rule 40? - tiiisance (including odors)
Rule 410 - Fugitive Dust
Regulation IX - Standards of Performance A
for ffcw Stationary Sources
Regulation X - National Emission Standards A. C
for Hazardous Air Pollutants
Rule 1167 - Air Stripping Operations A
(Reyulalion XI - Source-Specific Standards)
Prohibits the discharge of any material (including odorous conpcunds) M3UAPCD
that may cause injury, detriment, nuisance, or annoyance to the
public, businesses, or property, or endanger human health, canfort,
repose, or safety. This rule would be used for enforcement in odor
prublsn situations.
i
Limits cm-site activities so that the concentrations of fugitive tOlAPCD
dust at the property line shall not be visible and the downwind
particular concentration shall not be more than 100 micrograns per
cubic meter, averaged over 5 hours, above the upwind particulate
concentration. The rule also requires taking every reasonable
precaution to minimize fugitive dust. Hay be applicable for
construction activities.
Implements the provisions of Part 60, Chapter I; Title 40 of the . tOMPCD
Code of Federal Regulations (CFR) under the supervision of fCUAPCD
Executive Officer.
Implements the provisions of Part 61, Chapter I, Title 40, of the WtWCD
Cale of Federal Regulations (CFR) under the supervision of WUAPCO
Executive Officer, if contaminants identified at site are listed.
The rule is designed to reduce volatile organic compound (VOC) MBUAPCD
emissions from new and existing air stripping equipment used
for the treatment of contaminated water. The rule requires that al I
exhaust gases from air stripping equipment shall be vented through a
control device or process that will reduce the total VOC emissions to a
level that is at least 90 percent of the previous emissions on a mass
basis. Ibwever, the rule exaipts fran this specific requirement air
stripping equipment that have total VOC emissions of 1 pound per day.
or less. Recordkeeping of water and air stream analysis of VOC
concentration is required for all facilities. These requirements are
reflectal in the conditions of the existing air pennit.
GOV:006/-KT
DATE: 8/22/89
PIMAI RFVIRION
-------
TASf 2-2
POTENTIAL STATE APRICABLE OR RELEVANT AM) APPROPRIATE RflJUIROOfTS (ARABS)
(Continued)
KtgUIHOtNTS
TYPl
SLWWY
ADMINISTERING
AGENCY
Closure an] Postclosure of Interim
Status and Permitted Facilities
(Title 22; 67210-67220)
Closure and Postclosure of Interim
Status and Permitted Facilities (continued)
(Title 22, 67210-6/220)
Hazardous Uaste Mauler Registration
(Title 22. 66420-66465) and Reijiire-
ments for Transporters of lla/ardous
Uaste (Title 22. 66530-66664)
Hulford-Carre)I Air Resources Act.
Health and Safety Code. Division 26,
Section 30000 et seq. 17 CAT. Part III.
Chapter I. Section 60000 et seq.
A. C
Monterey Bay unified Air Pollution
Control District (HJttlAPCI)) Rules
arid Reflations
Rtijuldtion IV - Prutiiditioriary R
The facility shall be closed in a manner that minimizes the need OB
for further maintenance (6721 l[a]) and controls, minimizes, or
eliminates postclosure escape of hazardous waste, leachate.
contdiiinatod rainfall, or waste decomposition products to the
gru«) or surface waters or the aunosphere (6721 l[b]).
Contanination at the Firestone Site was identified during closure HIS
activities of a permitted facility. Thus. CMS is the lead agency
for this FS/RAP, although the site and adjacent contaminated ground
water are currently being raradiated and the facility has been for-
DBlly closed and the contamination source removal. Postclosure monitor-
ing requirements nust still be int.
Ih/dntous waste must be transported by a hauler registered 06
by the state.
The State counterpart to the Federal CAA. Mulford-Carrel I
establishes the California Air Resources Board (CARB) and
local Air Quality Management Districts (A^ds). The CARB and
AfJOs are given responsibility for protection of air quality
in the state. They oust also develop control measures for
reducing missions of the CARB-identified toxic air contaminants.
Permitting authority Is delegated in this act. The Firestone
facility and associated ranediation activities are subject to
permit, ru|uirenents issued under this authority. Al location of
allowable emissions are on an air basin specific basis.
The following sections and regulations fran KIUAPCOmay apply HDUAPCD
to a water-treaunent system, should air stripping be usod as a
techno) njv.-
CARB and (MBUAPCO)
COV:006/-RI
DATE: 8/22/89
FINAL REVISION
-------
TAfa. _-2
POTENTIAL STATE ATTI ICAW1 OR ROfWWT MO AffWFHIATE RHJUIKOfNTS (ARAftS)
REQUIRfKNTS
rm:'
SIWWY
ADMINISTERING
AGENCY
Hazardous Waste Control Act (Health and
Safety Code. Section 25100-25396) as
administered by the Department of Health
Services (DIIS) under tie California Code of
Relations. Title 22, Chapter 30; Hininun
Standards for Huui/nent. of Hazardous and
Extrunely Hd^dnius wastes.
IUCA has may elenents that are intenled to control hazardous
wastes firm their point of generation through accuiulatfon,
transportation, treatment, storage, and ultimate disposal.
It is inplanented largely through regulations under CCR.
Title 22. Division 4. Chapter 30. Section 66300 of Chapter 30
provides no ROW-type exsiption for CERCLA sites.
Criteria for Identifying Hazardous Uastes
(Title 22. 66693-66/46)
Reqjirunents for Generators of Hazardous
Uaste
(Title 22. 66470-66515)
Tests for identifying hazardous characteristics are described In OHS
Title 22, Article 11. Sections 66693-66746. If a waste is
either listed or tested and found hazardous, then mnaganent nust
caiply with the hazardous waste neqjiranents under Title 22. tttile
these standards are not treatment or disposal limits, the resulting
classification as hazardous waste results in efforts to meet the
standard, thereby nuking hazardous designation methods a form of
treatment standard.
An oner or operator who initiates a shipment of hazardous waste D6
fran a Transport, Storage, or Disposal (TSD) facility shall coiply
with the generator standards established under Article 6 (66470-66515).
Title 22 of CAT (66470[d]). These standards include keeping of
manifests (66481). submission of manifest to DIE within 30 days of
shipirot (66484[fj). preparation of a biennial report (66493[a]).
and a nvwiuun 90-day accuiulation tine (66508[a]).
GOV:0067-RT
DATE: B/22/8&
FINAL RFVISION
-------
WBlf ?-3
POTENTIAL ana nasw. CRITERIA. ADVISORIES. MO GUIDANCE ro HF OMSIDEVD (TBC)
REQUIRE* KTS
TYPE1
SIMWY
AB«INISTERING
AGEICY
Federal Criteria. Advisories, and Procedures
Health Effects Assessments (IIEAs) and C
Proposed l£As ("Health Effects Assessnent
for [Specific Chanical]"). ECAO. USEPA. 1985
Reference Duse (RflJs). ("Verified Reference C
Uuses of USEPA." ECAO^IN-475, January 1986)
Carcinogen Potency Factors (CPFs). (Table 11. C
"Ibalth Assessnent Uacuitnt for letrachloro-
ethylene (Perchloroethylene)." USff'A. QEA/
, July 198b)
Pesticide and food additive tolerances and C
action levels. Nute: Germane portions of
tolerances art! action levels nay be pertinent
anJ therefore are to be considered in certain
situations
Federal sole source aquifer requiranents A
(52 FR 6873. Mirch 5. 1987)
EPA's GrourJ Uiter Protection Strate
-------
KtqUIRtKKTS
TABLE 2-3
POTENTIAL ana HUM OUTEKIA. ADVISORIES AND OJIMNCE ID BE OMSUOED (ib
(Continued)
lYPt1
ADMINISTERING
AGENCY
Guidance on Rtiiulial Actions for Contamin- A
died GruinJ Wdter at Suierfund sites (Draft.
Octcter 191)6) establishes criteria for the
use of background concent rat ions did ACLs
Superfund Pub)ic Health Evaluation fenual C
EPA Health Advisories for Drinking Uater C
Sift* Maxiiiim Ctfitaninant Level Coals (MCLG) C
USEPA ROW Guidance Ducuients
Interim Final Alternate Concentration
Limits. Guidance Part I: ACL Policy and
Information Ra^iraitnts (vluly 1967)
Technical Resujrce OocirMits (TRDs).
RCRA Grounl-Uater Hnitorimj Technical
Enforcaient Guidance
USEPA Office of Witer (kiiddnce uocifiuits
Water -Relatal f/iviruniuital Fate of 129
Priority Pollutants (19/9)
Provides guidance on key decisions in the development, evaluation.
diil selection of ground-Mater ranedial actions.
Outlines health-based risk assessment.
These advisories are nonpronul gated concentrations of drinking
water contaninanls for organic and inorganic chsnicals. The
advisories are levels at tiiich adverse health effects would not
be anticipated to occur over specific exposure durations. For non-
carcino
-------
POTENTIAL Onifl FEUJML CRITERIA. AJV1SOUES AN) GUUWCE TO BE OMSIOERFD (IK)
(Continued)
RLguiROCNTS
TYPE
5LMWW
ADMINISTERING
AGENCY
Quality Criteria for Uiter 1986
Clean Uater Act Udter Quality Criteria for
Protection of llnian Health and Fresh Uiter
Aguatic Life bl FR 43666
Support Daamant for Uater Quality
Based Toxics Control
Uater quality Criteria (UQC) established under Section 304 of RUQGB
CWA (51 FR 43665). are based on effects of human health aid aquatic
life that do not reflect technological or economic considerations.
QA UQCs are applicable to water discharges to surface or ground water.
These substantive criteria would apply to uastewater discharges to .
the Salinas River.
Elaborates on water-quality-based toxics control. RUQCB
Developing Requirements for Direct and A
Indirect Discharges of C£RCIA Uastewater
(1987)
WOES Guidance Docunants - A
IfUES Best Kmaijonent Practices Guidance A
Kanual (Jurt 1'JHI)
Ground WiterAJIC Guidance Oocunuits - A
Corrective Action Keqjirenunts
Ground Uiter Protection Strategy (August 19U4)
Clean Uater Act Guidance Ibcunents A
£PA IRIS Cancer KisJt InfuniHtion C
Guidance for Corxlu.ting Won-didl Investigations A
aid feasibility Stulies lt«Vf CIWIA (Draft)
Explains development of vestewater discharges.
Presents guidance relative to ffUCS procedures.
Presents guidance on WOES GM>.
Presents yiidance relative to ground-water protection.
Presents guidance relative to CWA.
EPA IKIS cancer risk infomul ion represents the most current.
peer-reviewed ctanicdl concentrations in water producing risk
levels. The 10 risk level was used for the risk assessment
in this FS. The IRIS values are more current than the Clean
Water (Uiun Health Criteria for Drinking Uater.
Presents CfKCIA procedures.
RWQC8
RUQCB
RU)CB
EPA
EPA
DATE: 8/22/89
FINAI RFVIBION
-------
TABli 2-3
POTENTIAL ODIH FEDERAL CRI TIN I A. ADVISORIES MO OJ1DANCE ID BE OMSIOEDED (TBC)
(Continued)
RtQUIRtMN'5
FYPl
SLHWV
ADMINISTERING
AGENCY
Guidance on Preparing Siperfurri Decision
OocuiHit: Ihe Prxoosed I'I an and Recorx) of
Decision (Draft)
StaniJard C|>erating Safrty Unities
Presents ifiidance on preparing ROD.
Presents safety procedures for operations.
EPA
Cal-OSIM
Type of IBC: C-conlaciinant snecific, l.-lix.aliun specific, A-action specific.
DATE: 8/22
FINAL REVISION
-------
onnt STATE AM) LOCAL CRITERIA, AOVISCRIES. AW GUIDANCE ID BE CONSIDERED (TBC)
REQUlklKMTS
Department of Health Services Decision
Tree. Revised Oecaibcr 1906
Water Quality Control Plans at the State
Water Resources Control Board and the
Regional UaU-r Quality Control Board
WE1
SIMWRY
ADMINISTERING
AGEfCY
A. C Provides guidance on development of site-specific cleanup levels and DJIS
evaluation of ranodial action alternatives.
L Water Quality and Basin Plans. Use attainability studies and the State Water
current water quality of surface waters are used in determining Resources Control
allowable discharges to surface water bodies under WOES penults. Board; RvflCB
RtfJCfl Water Quality Control Plan
Effluent Limitations
016 Drinking Udter Action Levels (ALs)
L, A. C The Clean Water Act and Porter-Cologne Water Quality Act require
regional water quality control boards to develop water quality
control plans. Effluent limitations are specified in River
Basin Water Quality Control Plan. These limitations are not
praiulgated. but are considered when peniritting wastewater
discharges to surface water bodies.
C 046 action levels are specified for some of the organic contaminants
that have been identified in ground water. These levels in sane
cases are available for contaminants that do not have HCLs. 046
action levels are reconnended drinking water levels and are not
praiulgated, but could be used as policy or guidance. Water purveyors
in California will generally take action if the 016 notifies than of
contaminants exceeding ALs. ALs are not proiulgated, but are used as
016 policy. These are drinking water standards developed by the
UK and in practice nust be met to comply with 016 requirements.
RHP
OHS. ALs are also
used by other
agencies as the
basis for effluent
and disposal
limitations.
GOV:006/-RI
DATE: 8/22/89
FINAL REVISION
-------
HEQUIRLKNTS
T/ttf 2-4
onin STATC /N> IITAI CHITDUA. ADVISORIES. MO GUHWCE ID BE OKIKHD (TBC)
(Continued)
iri'E1
DI6 Applial Auiun Levels (AALs)
Central Valley tU£B Designated Level
Methudoloijy for Waste Classification
and Cleans Level Detenni nation
(October 1*6)
ABMNISIIRING
• Af£NCV
action levels are exposure limits that are pollutant-
n-ceptor-specific and used as a starting point for establish-
ing cleantf) levels. If the AALs are exceeded, then actions should
be takun to clean tf> contaminants dowi to these levels. In sore
cast-,, cleanup may be allowed by the 016 to be greater than the
Mis. However, justification oust be given for doing so, and the
0(6 oust approve the modified cleanup levels. Mater treatment values
should neet AAL standards for water discharges an! human receptors
(i.e., drinking water). Also, AALs are available for the air to human
pathway. Applied action levels are not proiulgated, but could be used
as policy or guidance.
This guidance docunent is in the tentative stage of development for use
in the classification and subsequent disposal method of both hazardous
and non-hazardous wastes. The method is still site specific but
generic; conservative classification levels can be approximated. The
Designated Levels are to be considered criteria.
Applied by 06
on a site-specific
basis.
RUQCB
'lype of IliU: C-cuntaminant specific, L-location specific, A-action specific.
1,0V: 0067-Kl
DATE: 8/22/8'
FINAL REVISION
-------
Date: 8/22/89
Final Revision
I ABIE 2-4
ORGANIC CONSTITUENTS
UAIEI QUALII1 GOALS - HUNAN HEALTH AND UEUARE
(1)
UKuAKIl
1.1-Ulcnloroethylene
I,)-Otchloroethane
|,2rDUhlorpethane
~ (tn/ene
(thylbeniene
tetracnloroetiiylene
Toluene
1,1,1-lrlcnloroeihaiM)
IrUhloroethylene
lylene(t)
NONCANCER
HEALTH
ADVISORIES OR
SIAIL ANU LPA UHUMW. VATLN SIANlUKlft
MAllMUN CONTAMINANT LEVELS (MClS)
PRIORI »CL~~MCL r,fiAir?p» 'syATt
o^TT ua/i jggilT
? ; 6
4 Zero O.b
S Zero 1
' / 1 \ i -i\
JUO1 J )OUl ' BHO
S13' Zero'1' S
/ 1 1 Ml
2.0UQ1 ' 2,cno' '
2»0 200 2UO
S Zero S
lo.noo'3' • lo.opo'3' i./so
UHS
UMIW1NG BAHH
ACTION LEVELS
TOIiqU TASTE 4 ODOR
iig/T uj/T
S
• ?9
6
• 100
IMS
APPLIED ...
ACTION LJVELS'"
HAW
Mj/T
O.I
680
100
200
620
SUGGESTED
NO-ADVtRS{.R(SPDNSE
LEVELS
CPU
JJJJZI
JO(4>
MO'4'
'0
680* 4)
19.400*4'
12,000'4I
200<4>
n
440<4>
(SNARLt)
•fcAS
100
340
1,800
ONE IN ONE MILLION INCREMENTAL
CANCER RISK LEVEL
EPA •- NATIONAL
AMBIENT HATER
quALITV CRITERIA
tali
0.94
0.66
0.8
?.»
f P» HIALTH OR
HATER OUALITV
ADVISORIES^
HJ/t ,
0.9S
0.68
0.6?
4.S
' NATIONAL
ACAOEN* OF
SCIENCES (HAS)
UgH
O.M '
1.6
,,(S)
l.S«S>
EPA -- NATIONAL AMBIENT
HATER QUALITY CRITERIA
BASED ON NONCANCER
PUBLIC HEALTH
al£T
1,41)0
14.300
18.400
Iro.n CalltornU Heyfondl Water guallty Conlrol Uujrd. Ctnlral Valley Region, !•)«/. Append 11 III, *lhe Designated Levtl Methodology (or Wattt CUtf Ulcitlon ind Cleanup Level Oeternlnat Ion.'
prepared by Jon. B. Marshack. revised September 14, I9U/. eicept for AAL'l (see Note 6).
'?IUHS, TSCD. Uecemlier 2. I9B7. human receptors; AAl »iter Is SIB Ac (Ion Level. •
'''proposed, updated as of Kd> ?2. 1989 Federal Register, pi). 22064. '
(4)Drjft/lentatlve. . '....'
on llolted evidence.
F|«:OU6;-I4-2re>
-------
Date: 8/22/89
Final Revision
TABLE 3-1 >
FLOHRATES FOR EXTRAaiON ALTERNATIVES
INTERMEDIATE AQUIFER
FORMER FIRESTONE FACILITY
EXTRACTION ALTERNATIVE
WELL
si
OLL
IT-IE1
IT-IE2
IT-IE3
IT-IE4
IT-IE5
IT-IE6
IT-IE?
IT-IE8
I.T-IE9
IT-IE10
150
150
150
100
_
_
150
_..
_
_
_
150
_
_
_
150
150
150
150
-
150
_
_
_
=
150
150
—
.
100
-
150
150
-
150
150
150
150
.
150
_
_
_
150
_
_
150
150
150
150
100
_
_
-
_
_
NOTE: Flowrates given in gpm.
Flowrates shown were used in the tradeoff studies
between various extraction alternatives. Actual
flowrates to be used in remediation will be
established by the Site Manager based on the
monitoring data for the recommended remedial
alternative, Alternative D, the combined flowrates
will not exceed 650 gpm, the current treatment
plant capacity.
FIR:0067-R8T31
-------
nis
IWIf <-i
IIAMINMION If AI IIUMIIVU WOOUS HHlMUAliir AiHICAUU Ot NUJUM AM) AflUHUAIl IO}J!I««MTS (AKMts)
AI IIHNAIIVf C - KIHIIIAR Al ItKtMlltf 0 - HfMUIAd
SIM I (W AMI INII m III AH SIMIUU AMI
Atjmrxs. iiioi HIM RAif. iHniMoiArr Aguiruts.
tt AW IXTAKSIIIN. fin Mtt UlSllfT. nJM, FlVt KU
IN UILS INIUMDIAIl tCH. tfUS
AUIKNAIIVC A - H> tiltCH
HIM 1)1 All
JJ WJJW
(M »
AIIIIINAIIU I - KIMIIIAIl
SIIAIIOUAM)
INIUMIHAII AIJUIUHS.
LIISIIMi HJH\. Ml ffW
ifo uus
-siieuf i£
Driniing I
-U3TH Safe Urinting Utter A}
.Huiuun Canldflidiiit Ltvels
-C06 Stdte Driitiny kfeter Ait
Drintiny Udtir Vlicn levels
-IWPA Artjitrt Ujti.f Quality
-U-iCA IL>dlUi IT killer
Hesiduil risk of Uunicdls in sail dfter soil raiuvdl is duaued
for dll dltenutives.
Allowing only iu(ur<)l
Ui uL«t varioiA clMniLjl-s)iinest in the shallow art!
01 interest in tit snalliM 120-fuut intenmlidte tune ai^jifers. lui-ther ccntdninatiu> <4 the deqi ttftifen is nut cx|iei:t»l
aifiiftr will te net. Die An to the clean^i of Uie gruund water in Die cuntributiny inlmnertiate anil shallow /ones.
puteiitial dr contdfliiidtiun
o( I)ULI> difjlfiTS due to lai:k
of nnnJul itn in the inter-
inuliale /ine is high.
-IHFM
AU, fbtiaul H)l 4>plicdt)le
Discharge (luniiutiui System
tnt Udter (Judlity Stdnlanis
-OWjCB. fOrter-ColLyi- Uiler
Quality Act. MltS *d Uiter
Qiallty Stvirknls
A. Cle<« Air Ait
-OWJ. HjllooKirn-ll Air
Rt-uuraes Ait
). Kules «
Nut
Uili/atitn of the oisling
tredUiut plant will not
result in any violations of
the existing permit rajuire-
auits with regard to dis-
ihjn>- i|ud(itity or
lit existini uenoit to ojier-
ate oruvides limitation on
the ra(e of treatment tw tie
air itriuper. total hydiu-
carUn umssiuns and anis-
siai I imitating for spe-
cific tmtjnindnls. (iiera-
t ion of the systai will be
ptrfoniul in cuipl iano? with
the existing (Mniit limita-
tiue> din)
hiyh flax rates
over 1,1100 yun envisionol
unler this alternative uvy
reiuine inalif icatiui of the
I, (ID gin flow limitations
conlainuJ in the exist inu
M11ES uEfwit. Mater Quality
an? not expect ««
to be enceakd, althouji
stdrt-ii> anl (Jctuyyiny of a
new air stripper nay
SUM id) water handling
tu assui«
treaUient.
Installation of a nan air
stripper wuild mfjire nulli-
fication at the existing flow
rate I imitations, the
NIMfCDny limit overall
onissions Iran both strippers
to the existing spurific con-
tdiiinant lyiantlties. Koni-
toriny both units separately
may be reiplru), as well as
detailud start 71(1 monitoring
for the new units, lotal
auissions iny exceed 7b per-
ctnt of Uie permitted aicunt,
utili/alion of the existing
treatment plant will nut
result in any violations of
the existing penait rei^iire-
umts with reganl to discharge
tfjantity or
The existing |«raiit hi oiierate
provides Imitation on the rate
of treaUiut by the air strip-
per, total hyaWarUn unis-
sions, an! uniss-ioji limitations
for specilic omtaniinants.
(Deration of the systoii will be
pertained in uii|iliance with
Uc existini pemiit liinit-
atiais and ai|iiruiuits.
Uili/ation of the existing
t realms* plant will not result
in any violations of the
existing penult reifjinnunts
with reuard to discharge
qjantity or quality.
Ihe existing penmt to out-rate
provides limitation ui tli- rate
of tredbient by the air strip-
per, total hydrocarUjn aiiis-
sions anJ emission limitations
for specific contaminants.
Operation of the systoii will lie
perloniul in onpliance with
the existiiij permit limit-
ations ami
HA:f IK 10/9-14
DATE: 8/22/89
FINAL REVISION
-------
IJttli 48
IXAXIHAIUM U * HMftllVtS 1/IJWfi POnNIMlV AMICM1 (It HUUAMI HO MWHUAIl ffqjINDflflS (AKAHs)
*' ,;
AMI IflIS fAt.ll«S
AllIKftAIIVJ A - N) ALllUN
Al IIKUAIM H
HI Mill All
INY
-IIS1PA. Clean Air Avt
-OKB. Act Hjlluru-Ortll Air
ttesuurtes
-HllAKi). Hula dnd H»*>ildUin
(cuilirual)
AinW4AI|W t - MHDIAIL
siMitu ANI INIIIMIIIAII
Al Jill I US. IIIUI IIIURAIF.
HANI IXPANSIin. 11VI MU
IHI1 Will All KH t4IIS
(••tent idlly nifjiriinj mm?
nuuluriuj. |uh-
^hiiviny
ttv ai^jiiiiiuits (uild uccir
if dir district tas in(le«-
ible r
/HIMNAIIM: »- MMIHAII
SllAlllU ANI
INIItMUIAR AlJIIIIHS,
UISIIM. PI ANI. iltf NfW
INIIKMDIAII AM 14US
Al IIW4AIIH I - WK1IIAII
SIMIIU AM)
INIIKHIHAII AIIUMHS.
UISIIM; I'lANI. IUIMU
INIIKHIHAII /Ot tlllS
). Sldftlanfc of IVrfunu-
£ (Of few jtdtlLIl.1l>
SuuA.es. Itw Suurui
Nut
Ml d(»)li(d(ilc
-HlWU/. Knp l»l
-U-JIA «d Cdl-OSlA Uaief dl
re«>ild-
fur
imldlldtlun
(U dpplic<4>li.'
Ht
-OSIIA an) UI-09IA
levels
Salisfact ion uf
tuns wuuld U>
dL'velupiut a
of d new dir
Incluks pntuislrticl ion rv-
view nxfjiruiHils prior lo
issiune of d permit lo coii-
Slrutl. fotenlidlly hl«Ji
expwsv dnl l*j tine ivfdlivo
lo the prujcil scojie tor cuo-
plldllU!.
HJ( d(4>li(.dl>le Ml d|tilitdl>le A puip lest permit Muld be rtifiiruj for lesluy of DM wells wttie disclunj.* of vuldtlle <
irktltxl uruj«I wdler with putentidl for dUusuheric rtleuse would u'cur. suth ds. in ML'11 (kw.-lop-
uut. tonih.mfe prU)luu> dn? nut dnlicipdted. ds tie levels of (onlduiiruliun div IOM dilvrut U> for all conslruclion did duiolilion drlivilies u»k.itdkui ftr lit site IkMllli do) Safety Plan.
lull ciiifillance with these stalues will be pni< i il per the existiny site health and safety plan. Uurter safety is assesswl
in lit risk dSSeisoMl by lew levels of worku 11 Ji.
HMWthelical wurker risk will
fae saivwhat hnjnr in this
scenario Ate lo iiKrivisixl
auissiuns, bit shuilil lie
wilhin Die 111 levels.
HA.f
DATE. 8/2^ i9
FINAL RE VISION
-------
MU 4-2
SUMRT OF (TTAIUD ANiniS OF OKDIAIUM A.IOMUUCS
AUVrSIS fAdORS
Short-let* effectiveness
pnutectiun is achieved
JM nHHAtm A - M) /trim
All! WWII VI n -
HINDI AH
VKU ajMIHH ffll»
AlirRMAIIVl C - RnCIIIAH
SIM 1 (If AM) INIDMDIAIE
A(|llf[RS. IIIGHFIMAII.
HAM liPAKSKM. FIVE MM
IHTIRHDIAIL «H KUS
AinRNftllVT D • KHDIAK
9W.Uk AM)
IMIDHUIArt AQJIfFJIS.
[IISIIIC FLAM. (IV MU
IMITHKDIArt flH tfUS
AHOVMIIVC E - RINVIAIE
SIMKM AM)
IMIDMUIAIE AtKUFIfiS.
CXISIIIC Fl/NI. IU) NTU
IfflllHOIAR KH UJUS
dnJ inlcnrMlule /une
*»jiler% ojiettaJ to rudi clean-
ill levels by Uinter
ProlecticTi conslsU of 1*1 of
sensitive rwn>lori and checking by
nnitoring to detemiw plwe oove-
niU anJ dispersion. Hininptline
(T'-jjiral for nnitorinq is b years.
iilif is expected to be
hy Uinter 1991/9?.
frotection for intenrediate lone
consists of lack of sensitive
reiffitors and assurance by •cnitor-
inj to detemine pluv mfMOfit and
dispersion. Hininm tin1 for roni-
torinj Is S >rMrs.
Ranaliation of the shallow and
intenodiale /one au^iifers is
expo, led to he con|)leted by Uinter
1991/9?.
RamJiatlon of the shallow and
inteimediate /one au>iifers is
expected to protect the deep
fro* future dnjratlat Ion.
Ranfiatlon of the shallow and
intemediate /one aquifers is
expected to be onpleted by fall
1990.
Same as Alternative C.
Damnation of the shallow and
intenadiate /one aquifers is
expected to be cmiileted by Uinter
1993/94.
Sane as Alternative C.
(VoUction of cumuiity
ranwlial acduis.
Neliance on natural mechanlsvB and
aeration throu/i spray irrigation
will retain? a lurej ti«e lo rair-
diate the shallow and intemixlUte
tin- Haulers aid «qy result in
of the ifeep ai|iifer.
Hpliance on natural nechanisms and
aeratiin thru«|i spray Irri9atian
will reifiire a Ion) ttaie lo me-
diate thi- intemediate /one apjjifer
anl nuy result in dujradat ion of the
Ramlial actions infer Ihrse alter-
ndtives iwy nut If lonsiikTed
cuiplete until nnilorinu, assum
prutrclion. II urutettian (km not
utuf. tlic (rtmlMl for antdniiiid-
tiin uf the <»M> »>ii(rr. usa) f
-------
SHORT or OCTAILED AM.KIS IF KMDIATMN * monies
(Continued)
AlltRNAIItt B -
HtHUIAE
AfttVSIS (AdORS AlllHNAIIW A - M) KHUN SIWHU AQJIHR (MY
Protection of xrters difing M>t «n>li«*le to site worters - Site wrier exposures are considered
ruirdul actions direct rundiation Mill Le negligible considering the arission
teminaleit. rates, ccnfainatlon of factors
rujjirul for exposure, and duration
oi expected mediation activities.
Caplidnce with standard operating
prut«kire and tfJIA regulations will
prolnt'Mixrliers during reiedial
attivities.
AinUNAUVl C - SSMDIArt
SIN (WAN) INHIHOIAn
AfjuiRRs. mniiirwwn,
HAM IKPAHSIfM. DM NW
IMnNHUIAII AM UlLS
Same as Alternative B.
AlITfiNMNE D-RMDIAIt
SHN.LQI AN)
INHIMUIAn AQJirOtS.
(iisiiic rum. ritf m
INHRKDIAIE AM tf US
Sane as Alternative B.
ALITIMMIVl C - RMUIAR
SIMtlOJ AM)
(xisiiic njwi. rut mi
INIDMVIAH AM If US
Sane as Alternative
B.
Ayricullural wxter exposiinp will
potntully he hufvr lr<*ise ol the
lrhn«/i (he RiU
untlutnl this rib' MBS
mininul.
Duration of enposure is less Uun
A.
Duration of etposure is only
sli
-------
SMfWT OF DETAILED AMUTSIS ff NDfDlATKM AITEHMTIMS
(Continued)
ANAUSIS FACIGRS
ALtTRNMIVE 6 -
W Mill All
AlRRNAH* A - H) ACIIOH SIWKW MfllfCR (HV
ftTERNMIVE C - REMHIATE
SIWUW AN) INIUMDIAIE
AOJIfWS. HIGHRnWHl.
PLANT EXPANSION. FIVE MM
imrmDiArt KH. OILS
ALTERNATIVE 0 - 1OWIAIE
9N.UU AN)
IHTEHWTOATE AOWERS.
EUSTIIG PLANT. Fltf NEW
INTERMUIATE WC tfLLS
AHEDNMIVE E - (CWJ)IArt
9W.UUMO
iNTtncDiATE AOIIFERS.
EXISIIIC PLANT. IW) WW
INTETMDIATE SH. ICLLS
t-lenn Effectiveness anil
relative n-sidwl risk, Hilerale residual risk, lack of Low residudl risk - ranedlation of
«/i risk dsses9 aifiifers.
Same as Alternative C.
Srtnc as Alternative C.
anl reliability of Icnj-lenmnjnilorini) will be long-tern mm i lor ing will be Honttorlng of ground-water wells Sane as Alternative C.
nti|ii(nl U> monitor natural attenua- reifiired to man it or that nigratlon will contlne throughout remediation
lion of tunt animation and nuinte- ol water (run the intermediate /one and for two years following achieve-
uf ground wattr i|iialily. will nt affect deeper ground water, ncnt of the cleanup levels. Treat-
ment plant monitoring will continue
during operation.
Same as Alternative C.
Hi treaUmt pi art m'raticns for
Altrmal ive A.
I he existing treatment system has Installation of a new air stripper Hie existing treatment system has Same as Alternative 0.
bun operate) reliably since Spring will retire a period of startup and beat operated reliably since Spring
lift ami is experiert to operate additional controls. 1986 and is expected to operate
reliably during the ronedial action. reliably during the remedial action.
No pndilons are expected in meeting No problems are expected in neeting
s. permit
F IR.006/M9I4
DATE: 8/22/89
-------
Table 4-2
SMMY OF DETAILED AM.VSIS IF (BOUTHM JDONOIKS
(Continued)
ANALYSIS (ACTORS
Al TERNATIVT. B -
WMDIAIt
MflflNAIIVE A - MD ACTION SIWIOU AOIIFEU OLV
ALTERNATIVE c - RTHDIATE
SIM LOf AN) INTTRrtUIATE
AQUIFERS. MIGHflonATE.
PLANT EXPANSION. FIVE NTH
INTEKrCDIAIE «K ItLLS
ALTERNATIVE 0 - REKDIATE
SWLWAIO
INTERKDIATE XQJIFERS.
tUSTItC PLANT. FIVE NtW
IWERrClHATE 20C UtLLS
ALTERNATIVE E - HEHPIATt
SHAIKH AM)
INTBKDJATE AQUIFERS.
ExisTiic PLANT, no tcu
INTDHDIATE W WHS
Reduction of To«icity. KJbility. or loxicity is reduced by
VOllTE
Treatnirt process and raicdy
-Annum of hazardous material
destroyed
-Reduction in toxicily, mtiility,
and volune
-Irreversibility of treatment
-type and Quantity of treabnent
residual
attenualion. (Ability is not
affected, volune of affected area
is increased allhaK/) at a reduced
concentration.
Air stripping and/or carbon adsorp- Air stripping and carbon adsorption Same as Alternative C.
Sane as Alternative C.
lion raluoe Uuicity. nobility, and
volune of chanicals in affected
uruul water.
reduce Uwicity, (utility, and
volun? of chanicals in affected
gronJ water.
Source, vadose zone, and grxuid-
water ai|iifers will not be actively
treated. Aeration and natural
mechanisms will be relied on to
reduce toxicity. The contaminants
will bo dispersed irreversibly
thn««/«)Ul the grant-water plure.
Contaminants In the shallow tone
ground water are actively reme-
diated. Source, vadose tone, and
intermediate and deep aquifer con-
tamination will not be actively
treated. Tor raicdlatlon of the
deep ami intenrodiate aquifers.
aeration thnugti irrigation and
natural ncchdnisms will be relied on
In reduce tcu icily. The contami-
nants will be disiwrsed irreversibly
thra«>uit the yrunil water pluie.
Contaninants In the shallow and
Intermediate zone ground water
agplfers are addressed. Atjiifer
remediation of the shallow and
Intermediate zone ninimi/e the
potential for further contamination
of the deep aojjlfers. Source.
vadose zone, and deep atjiifer
contdmlnatlon will not be treated
other than by the agricultural well
pipping.
Contaminants removed by the air
stripper will be emitted to the
atmosphere. Contaminants removed by
the cartxn unit will be sent to a
recycler for regeneration. Small
amounts of chanicals may he dis-
lo the Salinas Rivi-r.
Sane as Alternative C.
Same as Alternative C.
Sane as Mltematlvs C.
Sane as Alternative C.
f ID 006/K'H4
DATE: 8/22/1
FINAL REVISIOM
-------
TABU 4-?
SfHW OF OFTMUD /NtfSIS JX obtain easanents on private property
and connect than to the existing
systan.
ALTERNATIVE 0 - REKDIATE
SHALLOW AN)
INTETKDIATE AfJJIFERS.
EXISTirC PLANT. FIVE NBI
INTENrCDIATE 70C ICLLS
Sane as Alternative C.
ALTEHMTIVE E - RDCDIATE
SHULOI AND
INTEFHOIATE /QJIFERS.
EXISTING PLANT. TV) WU
INTERHDIATE XH UUS
Same as Alternative C.
-Reliability of lechnolmy
Del iance on natural mechanisms and
irrigation far ranErjiaticn is slow.
The existing treatment systan has Sane as Alternative B.
h«n derated since Spring 1986 with
a hl^h degree of reliability.
Technical problem with the existing
systan are not expected.
Sane e Alternative B.
Same as Alternative B.
-Fase of undertaking additional
raieclial ajrtion, if necessary.
Prior to dismantling the treatjnent
syslejn, maintaining the treabmit
plant in standby node for 2 years
will allnj
-------
SMWIV OF P£TAJL£D MN.YS1S OF KKDIATUM JUBBWIWES
(Continual)
WWYSIS FACTORS
AUKNAIIVI A- tOACMCN
WKDIATE
StIAtJ OW AqJIFEH OtY
M.HMMIIVE C - REMEDIATE
SIW.UW MO INTrRHHIATE
AQJIFERS. mai ficvRAii.
PLANT EXPANSION. FIVE MM
IKIENKUIATE MC tCLLS
ALTERNATIVE 0 - REKDIATE
9W.UM AW
IKIWCDIATl AQUIFOS.
EXISIIIC PIANT. FIVE NEU
IHTDHDIArE ffl»€ tfIIS
ALIERNMI* E - IDCDIAIE
IKIWCDIAIE JKJJIFFJG.
Eiisritc PUWI. no m
IHIWCDIArt «M If US
-Honitwing considerations
tustinq monitoring network of
grunt-water wplls will be usorl.
Existing rmnitoring network of
grand-water wells and treatment
plant vnpling points will be used.
In addition to existing systan,
monitoring will be <*Hnl at new
wells and at new air stripper.
.In addition to existing system,
nnitoring will be added at new
wells.
Sane as Alternative 0.
Aitninistrdtine feasibility
-Coordination with other agencies Ho pe> .rits rei|iired,
tto no* permits rwjjired.
ffttS anl miWCO permit mortlftc*- rto new permits retired.
tiorB would be retired for instal-
lation of a new air stripper.
(to new permits required.
Availability of Services and It) ntv services, materials or per- S*n- as Alternative A.
Materials smiel are nxuirul.
The availability of resources to
develop nat wells into the inter-
mediate rare is only expected to be
limited by the availability of land.
easanonls, ami right of ways, etc..
not by services or materials.
Same as Alternative C.
Sane as Alternative C.
Cost, rtet ('resent Uprth. $1 ,«B
-1 percent discount rale
-S percent discount rate
-10 percent discount rate
3.1*
I,M/
I, I Id
5.905
5.??2
5,«fl
1.829
1.7V
1,7(8
3.444
3,111
3.0U
10:006/1(914
DATE: 8/22/89-
FINAL REVISION
-------
UBU4-2
SLHNK OF CHARD) MUSIS v xmiuauN
(Cant liued)
AW.rSIS 'ACTORS
AimtNAIIVE B -
WMWAIT.
Ai UHNATIVl A - ND AUIGN SlWIfU AQIIFER plidnce with action-specific
tfct
Conplies with action-specific ARM.
Ihrun/i existing WJtS permit md
Hi WO) permit.
Overall Protecticn of tUivan
and
-Rpun hedlth and emirorrrtntal
protectitn throu/i risk elimina-
tion ratictim or toilful
Risk assessment shows current ri-i
is at acceptable level, this
alternative has UIKJ ikjralion ot
Sane as Alternative A, except that
duration of ejqwsure in shallow
is less.
Treatment plant «x)i float Ions to
acconmiate hio]i flow rate will
retire NKS permit rodif (catlore
of allowable flew rates and
permit to operate.
Conplles with action-specific ARARs
through existing NVES pemrit and
i permit.
Sane as Alternative 0.
Risk assess/rait shows current rlst Provides the best nix of protection SoneWut lower potential for risk
is at acceptable level. This alter- of all envlronnjital madia and runan reduction than Alternatives C and
health by concentrating on areas of due to lower contaminant capture ,
hig)i contamination first. capabilities of a be well Inter-
nal late tone extraction system
(conjured to five well systems).
native has short duration of
exposure.
Honed i at I on of contaminated grand
water In the shallow ard Interme-
diate zone aifjlfers will protect the
deq> aojjlfers fron further contami-
nation and reduce luiun health and
envirunmmtar risk.
Sane as Alternative C.
as Alternative C.
I IH
DATE: 8/22/89
FINAL REVISION
-------
May 25, 1989
Alternative
Table 4-3
COST COMPARISON OF ASSEMBLED ALTERNATIVES
FIRESTONE
(11,000's)
Increiental Net Present Worth
Short-ten Long-ten* at Discount Rate
Capital Cost DIN Cost 3 Percent S Percent 10 Percent
z
o
A:
8:
C:
D:
E:
Pulping rate : 0 gpi
No Action. 10 years
Puip Increientally 500 gpi to 0
12.83 years
Puip Incrementally 1150 gpa to 0
Expand plant * five nells. 4.67
Puip Incrementally 650 gpi to 0
Add five wells, 3.42 years
Puip Increnentally 500 gpi to 0
Add two Nells. 6.67 years
Varies
Varies
510 Varies
275 . Varies
200 Varies
1,525
3,186
5,905
1,829
3,444
1,387
2,990
5,722
1,792
3,311
1,116
2,588
5,308
1,708
3,017
-------
25-Hay-89 Table 4-4
COST SUMMARY OF ALTERNATIVE A
NO ACTION - PUMPING RATE : 0 - tr
10 Years (April '89 to April '00)
FIRESTONE
Annual
Estmted
Cost Iteis Costs
Construction Costs
All capital costs are 'sunk* and not a part of this evaluation.
Monitoring (0 I M)
10 Years Monitoring 314,000 /MO. : $168,000
Total Plant Operation (0 4 fl)
2 Years Standby Only $4,000 /MO. : $43,000
ANNUALIZEO COST 0 4 M
NET PRESENT WORTH OF ANNUALIZED 0 4 H COST
(Unifori Series Present north for 10 Yrs.)
3\ 8.530 factor . $1,433,074
5\ 7.722 factor $1,297,251
10* 6.145 factor $1,032,287
(Unifori Series Present north for 2 Yrs.)
•n 1.913 factor 191,847
5\ 1.859 factor $89,252
10* 1.736 factor $83,306
TOTAL PRESENT HORTH Of ANNUALIIED 0 I M COST ALTERNATIVE A
At 3 percent $1,524,921
At 5 percent $1,386,503
.At 10 percent $1,115,593
-------
25-Hay-89 Table 4-5 ^O
COST SUMMARY OF ALTERNATIVE 8 ® 55
' PUMP INCREMENTALLY - PUMPING RATE : SOOgpl to 0 £J>
12.83 Years (April '89 to Jan. '02) . •- £
FIRESTONE *•_,
Annual £i<
Estimated <-
Cost Iteis Costs
April '89 to Jan '92" Puiping rate 9 SOOgpi
2.75 Years Duration End puip 4 treatient Jan '92
Construction Costs
All capital costs are 'sunk* and not a part of this evaluation.
Monitoring (0 4 M) 118,000 /MO.
Total Plant Operation (0 4 N) . $35,200 /HO.
Includes air stripper 4 carbon treatient
$53,200 /MO. : $638,400
NET PRESENT WORTH OF ANNUALIZED 0 4 M COST
(Unifori Series Present Worth for 2.75 Yrs.)
3* 2.602 factor $1,661,344
5* 2.511 factor SI,603,165
10* 2.306 factor. 11,471,948
January '92 to January '02 Puiping rate 0 0 gpi
10 Years Duration
Monitoring (0 4 H) $14,000 /HO. = 1168,000
Total Plant Operation (0 4 H) On standby $4,000 /HO. = $48,000
For txo years
NET PRESENT WORTH OF ANNUALIZED 0 4 H COS! '
(Unifori Series Present Worth for 2 Yrs.)
3* 1.913 factor $91,847
5* 1.859 factor $89,252
10* 1.736 factor $83,306
NET PRESENT WORTH OF ANNUALI2ED 0 4 H COST
(Unifori Series Present Worth for 10 Yrs.)
31 8.530 factor $1,433,074
5* ' 7.722 factor . $1,297,251
10* 6.145 factor $1.032,237
TOTAL PRESENT WORTH OF ANNUALIZED 0 4 H COST ALTERNATIVE B
At 3 percent $3.!S6,:s4
At 5 percent . $2.989.6s3
At 10 percent $2,587,541
-------
25-Hay-89
Cost Iteis
Table 4-6
COST SUMMARY OF ALTERNATIVE C
PUMP INCREMENTALLY, EXPAND PLAHT; AOO FIVE HELLS - PUMPING RATE : 1150 gpi to 0
4.67 Years (April '89 to January '94)
FIRESTONE
Annual
Estiiated
Costs
April '89 to January '92 Pimping rate « 500 gpt
2.75 years Duration End puap S treat 01/92
Construction Costs
All capital costs are 'sunk* and not a part of this evaluation.
Monitoring (0 & M)
Total Plant Operation (0 4 n)
NET PRESENT WORTH OF ANNUALIZEO 0 4 M COST
(Unifon Series Present north for 2.75 Yrs.j
J* 2.602 factor
5* 2.511 factor
10\ 2.306 factor
$18,000 /HO.
$35,200'/MO.
$53,200 /HO.
$1,755,600
$4,568,696
$4,408,704
$4,047,856
0)0
• V)
™>
N UJ
Ou.
Noveiber '89 to October '90 Putping rate * 650 gpi
1 year Duration Puip and treat 120' Mils
Monitoring (0 & M)
Total Plant Operation (0 4 n)
(included above)
(induces above)
NET PRESENT HORTH OF ANNUALIZED 0 4 H COST
(Unifori Series Present Morth for 1 Yrs.i
l\ 0.971 factor
5* . 0.952 factor
10* 0.909 factor
JO /MO.
JO /C.O.
JO /KO.
JO
JO
JO-
JO
-------
,r
25-May-89 Table 4-6 (cont.) 2
COST SUMMARY (CONTINUED) OF ALTERNATIVE C - S2
PUMP INCREMENTALLY, EXPAND PLANT; ADO FIVE NELLS - PUHPING RATE : 1150 gp« to 0 SJ 2
4.67 Years (April '89 to January '94) ^cc
FIRESTONE . QJ J
Annual K-Z
Estiiated oil
Cost Iteis Costs
January '92 to January '94 Pulping rate 0 gpi
2 years Duration Treatient plant on standby
Monitoring (0 t N) $14,000 /HO.
Total Plant Operation (0 I II) (on standby) $4,000 /HO.
$18,000 /HO. : $432,000
NET PRESENT NORTH OF ANHUALIZEO 0 i H COST
(Unifori Series Present North for 2 Yrs.)
3t 1.913 factor $826,619
5* 1.859 factor • $803,265
101 1.736 factor $749,752
June '89 to October '89 Expand plant, add five nex wells and pipline
Construction Cost Nells and pipeline $275,000
Plant expansion $235,000
Total Construction Cost $510,000
TOTAL PRESENT NORTH OF ANNUALIZED 0 i N AND CAPITAL COSTS ALTERNATIVE C
At 3 percent 15,905,314
At 5 percent . $5,721,970
At 10 percent $5,307,603
-------
25-May-89
Cost I teas
Table 4-7
COST SUMMARY OF ALTERNATIVE 0
PUMP INCREMENTALLY, ADD FIVE WELLS - PUMPINS RATE : 650 gpi to 0
3.42 Years (April '89 to Septeiber '92)
FIRESTONE
Annual
Estiaated
Costs
April '89 to July '89
0.2S years Duration
Puaping rate 500 gpj
Puip and treat Onsite nells
Monitoring (0 4 M)
Total Plant Operation (0 t H)
NET PRESENT NORTH OF ANNUAL1ZEO 0 i M COST
(Unifon Series Present Worth for 0.25 Irs.)
3* 0.245 factor
5* 0.242 factor
10* 0.235 factor
$18,000 /MO.
$35,200 /HO.
$53,200 /MO.
$159,600
839,163
$38,698
$37,579
2
C
si
July '89 to Noveaber '89 Puaping rate 500 gpi
0.33 years Duration Puap and treat Qffsite Nells
Monitoring (0 I M)
Total Plant Operation (0 4 Mj
NET PRESENT WORTH OF ANNUALIZED 0 i H COST
(Unifon Series Present worth for 0.33 Yrs.)
3* 0.324 factor
5* 0.319 factor
M 0.310 factor
$18,000 /MO.
$35,200 /MO.
$53,200 /MO. :
$210,67:
$68,166
$67.296
$65,230
-------
25-May-89 • Table 4-7 (cont.)
COST SUMMARY (CONTINUED) OF ALTERNATIVE 0
PUMP INCREMENTALLY, AOO FIVE HELLS - PUMPING RATE : 650 gpl to 0
3.42 Years (April '89 to September '92)
FIRESTONE
Annual
Estimated
Cost Iteis Costs
Noveiber '89 to October '90 Pushing rate 650 gpt
1 /ear Duration Puip and treat 120' wells
End puip & treat October '90
Monitoring (0 4 M) $18,000 /MO.
Total Plant Operation (0 I M) $35,200 /MO.
$53,200 /MO. : $638,400
NET PRESENT WORTH OF ANNUALUED 0 i H COST
(Unifori Series Present Worth for 1 Yrs.) -
3\ 0.971 factor $619,806
51 0.952 factor . . $608,000
10* 0.909 factor $580,364.
October '90 to October '92 Pulping rate 0 gpi
2 years Duration Treatment plant on standby
Monitoring (0 4 H) $14,000 /MO.
Total Plant Operation (0 4 fl) (on standby) $4,000 /HO.
$18,000 /NO. : ' $432,000
NET PRESENT NORTH OF ANNUALIZED 0 4 M COST
(Unifori Series Present North for 2 Yrs.)
3* 1.913 factor $826,619
5\ 1.859 factor $803,265
10* 1.736 factor $749,752
June '89 to October '89 Install f^ive ne» nells and pipline
Construction Cost $275,000
TOTAL PRESENT NORTH OF ANNUALHEO 0 4 H AND CAPIIAL COSTS ALTERNATIVE 0
At 3 percent $1,828,759
At 5 percent $1,792,260
At 10 percent . • $1,707,925
-------
r'
25-May-89 Table 4-8 «2
COST SUMMARY OF ALTERNATIVE E ^j-
PUMP INCREMENTALLY, AOO TWO NELLS - PUMPING RATE : SQOgpt to 0 c>4 J2
6.67 Years (April '89 to Jan. '96) w^
FIRESTONE £•£
Annual JjZ
Estiiated oil
Cost Iteis Costs
April '89 to July '89 Putping rate 8 SOOgpi Onsite Nells
0.2S Years Duration Puip 4 treat on and offsite Nells
Construction Costs
All capital costs are 'sunk* and not a part of this evaluation.
Monitoring (0 4 H) $18,000 /MO.
Total Plant Operation (0 4 M) . • US,200 /MO.
$53,200 /HO. : $638,400
NET PRESENT' NORTH OF ANNUAUZED 0 4 M COST
(Unifori Series Present North for 0.25 Yrs.)
3* 0.245 factor $156,673
51 0.242 factor $154,792
10* 0.23S factor 1150,317
July '89 to Noveiber '89 Puiping rate 8 500 gpi Offsite Hells
0.33 Years Duration
Monitoring-(0 4 M) J18.000 /HO.
Total Plant Operation (0 4 ,1) $35,200 /MO.
$53,200 /MO. : $638,400
NET PRESENT NORTH OF ANNUftLHEO 0 4 H COS1
(Unifori Series Present Worth for 0.33 Yrs.)
l\ 0.324 factor $206,565
51 0.319 factor . $203,928
10* 0.310 factor $197,667
Noveiber '89 to January '94 Puiping rale « 500 gpi 120' depth
4.17 Years Duration Puip and treat
Monitoring (0 4 N) $18,000 /MO.
Total Plant Operation (0 4 M) $35,200 /MO.
$53,200. /MQ. : $638,400
NET PRESENT WORTH OF ANHUALIZEO 0 4 N COST
(Unifori Series Present Worth for 4.17 Yrs.)
. 3\ . 3.866 factor $2,467,765
5\ 3.682 factor $2,350,500
10* . 3.280 factor $2,093,';3
-------
25-Hiy-89 Table 4-8 (cant.) ^
COST SUMMARY (CONTINUED) OF ALTERNATIVE E ^£
PUMP INCREMENTALLY, AOO TWO HELLS - PUMPING RATE : 500gp« to 0 eg uj
6.67 Years (April '89 to Jan. '96) «°"
FIRESTONE uJ<
Annual < 5
Estiiated ou>
Cost Iteis Costs
January '94 thru January '96 Puiping rate 8-0 gpi^ Monitor only, plant on standby.
2 Tears Duration Puip S treat ends 01/94
Construction Costs
All capital costs are "sunk* and not a part of this evaluation.
Monitoring (0 t n) 114,000 /no.
Total Plant Operation (0 4 .1) (on'standby) $4,000 /NO.
$18,000 /HO. : $216,000
NET PRESENT NORTH OF ANNUALHED 0 t 1 COST
(Unifon Series Present north for 2 rrs.)
l\ 1.913 factor $413,309
51 1.859 factor $401,633
101 1.736 factor $374,876
Construction Costs
TNO new (120') veils and pioeline ' $200,000
TOTAL PRESENT WORTH Of ALTERNATIVE E
At 3 percent 13,444,312
At 5 cercent $3,310,854
At 10 percent $3,016,583
-------
FIGURES
-------
(O
o
o
li
(ED
QZ
iCO
C
•f?»«*?s:;
liillll
:.*«<
FORMER
FIRESTONE
FACILITY
ASHWORTH
BROTHERS
SITE
LEGEND =
{ | SALINAS URBAN AREA
SITE
SCALE
2 MILES
FIGURE I-!
VICINITY MAP
FORMER FIRESTONE FACILITY
SALINAS, CALIFC"';: A
PREPARED
REFERENCED
7.5MIN. U.S.G.S. TOPOGRAPHIC MAP OF CHULAR,
NATIVIDAD, SALINAS 8 SPRECKEL5 .CALIFORNIA
QUADRANGLES, DATED 1947, PHOTOREVISED 1968,
1984,1973,1984 RESPECTIVELY. SCALE' I-24,COO
' 1984 IT CORPORATION
ALL COPYRIGHTS RESERVED
FIRESTONE TIRE 8 RUBBER CO.
AKRON, OHIO
.. Creating a Saier Tomorrow
Do Not Scale Thu Drawing
-------
SAWN i TRS I CHECKED 9* \tt*/ \'t-'t-te [DRAWING
8" I9-I9-9B I APPROVES 9Y I Jt* l^//f/»» |NUMB£»
190067-89
AREA I
AREA 2
AREA 3
AREA 4
AREA 5
AREA 6
AREA 7
AREA 8
PROPERTY
BOUNDARY
IOOOFEET
FUEL STORAGE
COURT YARD
RAILCAR UNLOADING
SLUDGE BEDS
HOLDING PONDS
SEEPAGE PONDS
WASTE OIL TANKS
EVAPORATION PONDS
REFERENCE -
EXHIBIT B OF RAO HSA 85/86-002
ALL CQPraiGMTS RESERVED
F.IGURE 1-2
SITE PLAN
FORMER FIHESTOIVE fiCILI'T
SALINAS, CALIFORNIA
FIRESTONE TIRE a RUBBER CO.
AKRON, OHIO
... Ci»r?tlBfT a Sel«r Tomorrow
-------
WELL LOCATION MAP
IN SHALLOW AQUIFER
FORMER FIRESTONE FACILITY
SALINAS. CALIFORNIA
PREPARED FOB
FIRESTONE TIRE 8 RUBBER CO
AKRON. OHIO
Cr*atln0 a Safer Tomotrow
-------
-------
WELL LOCATION MAP FOR
MONITORING WELLS IN DEEP AOUIfEH
FONUCK pifttSToMC rjtcnrTr
-------
*tLL LOCATION MAP FOR AGRICULTURAL
DOMESTIC. INDUSTRIAL 8 MUNICIPAL WELLS
IN DEEP AQUIFER
-------
*
m
evj
N
40 FEET
FUEL, N.D.
PC8, N.D.
tu
-------
3
cvj
<
X
to
o
o
C5
RAWINI
UMBER
Q
*m
4)
ALL COPYRIGHTS RESERVED KJLJ . - • Ci9oung a saioi Tomorrow
Do Not Scale Tnu Drawing
-------
cvj
(0
o
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11
c 3
02
Is
PHASE B AREAS
•EDGE OF LOADING DOCK
470ppm,0a<*
15 APPROXIMATE
-------
to
CVJ
CM
< 2
(E3
02
515
a «
DRYING BED
SURFACE TO 36 FEET
GROUND WATER«47 FEET
DRYING BED
63,400ppm 08G
5.2ppm Nl
2.9ppm Pb
SURFACE TO 36 FEET
GROUND WATER ® 45 FEET
43,400 ppraOSG
17ppm Ni
2.8ppm Pb
DRYING BED
SURFACE TO 36 FEET
GROUND WATER648 FEET
44,900ppm OSG
55ppm Ni
6ppm Pb
NOTES
I. FOR PLAN LOCATION OF
AREA 4, SEE FIGURE l~2
LEGEND
® SOIL SAMPLE LOCATION
086 OIL AND GREASE
REFERENCE*
WOODWARD-CLYDE
CONSULTANTS, I984o
1984 IT CORPORATION
ALL COPYRIGHTS RESERVED
100 FEET
FIGURE 1-10
AREA 4-THREE SLUDGE DRYING BEDS
SOIL SAMPLE LOCATIONS
AND CHEMICAL CONCENTRATIONS
FORMER FIRESTONE FACILITY
SALINAS, CALIFORNIA
PREPARED FOR
FIRESTONE TIRE 6 RUBBER CO.
AKRON, OHIO
. Creating a Safer Tomorrow
Do Not Seal* Thu O'awmg-
-------
r-
0~Z
sS
li
OC 3
QZ
^Tt
Mi
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to
-------
i=
_ UJ
II
CC 3
QZ
rani
CD
O
00
Z
3>
Q.
o
o:
Q.
SEEPAGE POND
GROUND WATER^ 24 FEET
4.2ppb Pb
21 ppm Ni
53ppm Zn
SEEPAGE POND
ui
z
tr
ui
Q.
o
NOTES
FOR PLAN LOCATION OF
AREA 6, SEE FIGURE I-2
LEGEND
®SOIL SAMPLE LOCATION
REFERENCE'-
WOODWARD-CLYDE
CONSULTANTS, 1984 Q
1984 IT CORPORATION
ALL COPYRIGHTS RESERVED
50
100 FEET
FIGURE 1-12
AREA 6 - SEEPAGE PONDS
SOIL SAMPLE LOCATIONS
AND CHEMICAL CONCENTRATIONS
FORMER FIRESTONE FACILITY
SALINAS, CALIFORNIA
PREPARED FOR
FIRESTONE T»RE & RUBBER CO.
AKRON, OHIO
Creating a saxer Tomorrow
Do Not Scale This Drawing
-------
<
CC3
O Z
CD
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-------
CD
CNJ
OJ
!'.
II
tr 3
QZ
g^M
d
s D'awmq
-------
CENTRALIZED OR
DISPERSED TREATMENT
FIGURE 2-1
TECHNOI OGY SCREENING SUMMARY
PHYSICAL TREATMENT METHODS
FIRESTONE TIRf ft RUSHER COMPANY
INTKKNATIONAI.
TECHNOLOGY
CORPORATION
PHYSICAL
TREATMENT
COAGULATION/aOCCULATION
-H:
OIL-WATER SEPARATION
FLOTATION
MEDIA FILTRATION
ABSORPTION/ADSORPTION
-»- PHYSICAL ADSORPTION
-•- CHEMISORPTION
CAS-PHASE STRIPPING
AIR STRIPPING
STEAM STRIPPING
ALTERNATE GAS STRIPPING
REVERSE OSMOSIS
DIALYSIS
ELECTRODIALYSIS
ULTRAFILTRATION
FREEZE PROCESSING
~- FREEZE CRYSTALLIZATION
•- FREEZE DRYING
—»- SUSPENSION FREEZING
»- ZONE REFINING
DISTILLATION
EXTRACTION
»- SOLVENT EXTRACTION
—•- LEACHING
—*- LIQUIFIED GAS EXTRACTION
—•- SUPERCRITICAL FLUID OXIDATION
»- STRIPPING
MECHANICAL SEPARATION/TREATMENT!
--*- CENTRIFUGES
--*- BELT FILTER PRESSES
-•- AIR CLASSIFIERS
-•- VIBRATING SCREENS
—•- SHREDDLRS/GRINDERS
1—^- HYDROCYCLONES
MAGNETIC SEPARATION
-»— MAGNETIC CONDITIONING
-^- HIGH GRADIENT MAGNETIC SEPARATION
EVAPOSA IION/CKYSIAl' IZAilO.M/DRYING
HII (Hlli/A4
-------
CENTRALIZED OR
DISPERSED TREATMENT
FIGURE 2-2
TECHNOLOGY SCREENING SUMMARY
CHEMICAL. BIOLOGICAL. AND
THERMAL IREATMENT METHODS
I'REPARID FOM
FIRESTONE
IIRE & RUBBER COMPANY
INTKRNATIONAI,
TKCHNOI,O(;Y
CORPORATION
JICAL
TREATMENT
-H:
BIOLOGICAL
TREATMENT
NEUTRALIZATION
PRECIPITATION
LIQUID/SOLID PRECIPITATION
ELECTROSTATIC PRECIPITATION
ION EXCHANGE
OXIDATION
CHEMICAL
WET AIR
SUPERCRITICAL FLUID
ELECTROLYTIC
THERMAL
BIOLOGICAL
REDUCTION
ELECTROLYTIC OXIDATION/REDUCTION
CHEMICAL REDUCTION
DIRECT HYDROGENATION
PHOTOLYSIS
IRRADIATION
STABILIZATION
INORGANIC MICROENCAPSULATION/FIXATION
INORGANIC VITRIFICATION
ORGANIC MICROENCAPSULATION
ORGANIC ENCAPSULATION
AEROBIC DEGRADATION
ACTIVATED SLUDGE TREATMENT
AERATED PONDS OR LAGOONS
TRICKLING FILTERS
POWDERED ACTIVATED CARBON TREATMENT
ANAEROBIC DIGESTION
ENZYMATIC CONVERSION
IN SITU BIOLOGICAL. REMEDIATION
CON TROLLED BACTERIAL APPLICATIONS
NATURALLY SELECTED
GENETICALLY ENGINEERED
COMPOSTING
AQUACULTURE
THERMAL
TREATMENT
I'l P (i<)6 /A5 OJH9
INCINERATION
CALCINATION
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PLASMA P1ROLVSIS
NUCLEAR DESTRUCTION
-------
GE.NI.R. LSI'ONSE AC 11011
urniAi ii.cumu COY
IECHNOIOGY PROCESS OPTION
SHUT DOWN
EXISTING SVSTF'M
PUMP
ON SITE
WELLS
PUMP
OFFSITE
WELLS
PARTIAL
REMOVAL
OFFSITE
DISPOSAL
NONE
GROUND-WATER
ex FRACTION
GROUND-WATFR
EXTRACTION
• GROUND-WATER
EXTRACTION
NONE
GROUND -WATER
EXTRACTION
WELLS
GROUND-WATER
EXTRACTION
WELLS
GROUND- WATER
EXTRACTION
WELLS
SURFACE DISCHARGE
FOR AQUIFER RECHARGE
WELL INJECTED
FOR AQUIFER RECHARGE
WATER
USE
NONE
GROUND-WATER INJECTION WELLS
PRETREATMENT
POST-TREATMENT
NONE
FIGURE 2-3
INTERNATIONAL
TKCHNOI-OCY
COHI'ORATIDN
KM (Wlli/AI ll.^H'J
TECHNOLOGY SCREENING SUMMARY
TECHNOLOGY PROCESS OPTIONS
PREPARED FOR
FIRESTONE
TIRE & RUBBER
COMPANY
-------
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FACILITY
POTENTIOMETRIC SURFACE
SHALIOW AQUIFER
MARCH 1969
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SALINAS. CALIFORNIA
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-------
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-------
NDII/III LIMIT OF
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-------
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FIGURE * 6
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-------
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-------
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DEEP AOUIFER
1,1,1-TCA MAXIMUM CONCENTRATIONS
4/88 TO 3/89
'OffMf* ' "ft
SALINAS
-------
FORMER
FIRESTONE
FACILITY
FIGURE 3-9
EXTRACTION WELL LOCATIONS
FOR 1'iif.lPiNG ALTERNATIVES
IRESTONE TIME 8 RUBBER CO
AKRON, OHIO
CnottDO a Sate TOOWROW
-------
FORMER
FIRESTONE
FACILITY
ISOgpm IT-IE3 \ HT-UZ
FIGURE
EXTRACTION WELL LOCATIONS
PUMPING ALTERNATIVE i
FIRESTONE TIRE 8 RUBBER CO
AKRON, OHIO
Craatlno a Safm Tomanow
-------
FORMER
FIRESTONE
FACILITY
FIGUHE n Jb
tXTPACTION AELL _'.)C6TIONS
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Ci*ating a SotOT Tomonow
-------
FORMER
FIRESTONE
FACILITY
FIGURE ' 9c
EXTRACTION WELL LOCATIONS
PUMI IN'i .'.LrERN/UIVE 3
FIRESTONE HRE 8 RUBBER CO
AKRON. OHIO
Creating a Saisr Tomorrow
-------
FORMER
FIRESTONE
FACILITY
FIGURE 3-9(1
EXTRACTION WELL LOCATIONS
PUMPING ALTERNATIVE
FIRESTONE TIRE 8 RUBBER CO
AKRON, OHIO
Qtullofl a ScilAi Tomonow
-------
FORMER
FIRESTONE
FACILITY
IT-IE2 IT-IEI
ISOgpm
FIGURE 3-9e
EXTRACTION WELL LOCATIONS
PUMPING ALTERNATIVE 5
FIRESTONE TIRE 8 RUBBER CO
AKRON, OHIO
-------
FORMER
FIRESTONE
FACILITY
FIGURE 3 91
EXTRACTION WELL LOCATIONS
PUMPING ALTERNAIIVE 6
FIRESTONE TIRE B RUBBER CO
AKRON, OHIO
Cnotlng a Sai«t Tomorrow
-------
FORMER
FIRESTONE
FACILITY
EXTRACTION WELL LOCATIONS
ALTERNATIVE B
FIRESTONE TIRE 6 RUBBER CO
AKRON, OHIO
emoting a Sal«i Tomorrow
-------
0S-IO
FORMER
FIRESTONE
FACILITY
FIGURE 3 II
EXTRACTION WELL LOCATIONS
ALTERNATIVE C
FIRESTONE TIRE 8 RUBBER CO
AKRON, OHIO
Creating a Sal*r Tomottow
-------
FORMER
FIRESTONE
FACILITY
FIGURE 3-12
EXTRACTION WELL LOCATIONS
IRESTONE TIRE 8 RUBBER CQ
AKRON, OHIO
-------
FORMER
FIRE.STONE
FACILITY
FIGURE ? l3
EXTRACTION WELL LOCATIONS
ALTERNATIVE E
FIRESTONE TIRE 8 RUBBER CO.
AKRON, OHIO
Creating a Salci Tomanow
-------
SHALLOW
MODEL AREA
AQUIFER
DIATE A
EL ARE
FIRESTONE TIRE B RUBBER CO
AKRON, OHIO
-------
01
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ALTERNATIVE A
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NOTE:
FOR PLAN LOCATION OF MODEL
AHEA SHE FIGURE 4 1
OUTLINED AREA ENCOMPASSES
CLEANUP LEVELS FOR EACH
CONSTITUENT
FIGURE 4-1A
ALTERNATIVE A
PLUME MIGRATION
SHALLOW AQUIFER
PREPARED FOR
FIRESTONE TIRE & RUBBER CO
AKRON, OHIO
INTERNATIONAL
TECHNOLOGY
CORPORATION
-------
P)
ffl
1/89
ALTERNATIVE A
1/90
0?
1/91
1/92
1/93
1/94
-I '
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PLUME MIGRATION
INTERMEDIATE AQUIFER
NOTE
FOR PI AN LOCATION OF MODEL
AREA SEE FIGURE 4 -1
OUTLINED AREA ENCOMPASSES
CLEANUP LEVELS FOR EACH
CONSTITUENT
FIGURE 4-18
ALTERNATIVE A
PLUME MIGRATION
INTERMEDIATE AQUIFER
PREPARED FOR
FIRESTONE TIRE & RUBBER CO.
AKRON. OHIO
INTERNATIONAL
TECHNOLOGY
CORPORATION
-------
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o
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2
ALTERNATIVE B
2/89
6/09
Cl
10/89
Id
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FACILI)
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9CAIE
0 SOO 1000 FT
NOTE:
FOR PLAN LOCATION OF MODEL
AREA StE FIGURE « '
OUTLINED AREA ENCOMPASSES
CLEANUP LEVELS FOR EACH
CONSTITUENT
FIGURE 4-2A
ALTERNATIVE B
PLUME MIGRATION
SHALLOW AQUIFER
PREPARED FOR
FIRESTONE TIRE & RUBBER CO.
AKRON, OHIO
INTERNATIONAL
TECHNOLOGY
CORPORATION
-------
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1/89
1/90
1/91
1/92
L'
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1/93
1/94
\
PLUME MIGRATION
INTERMiOlATE AQUIFER
FOR PLM4 LOCATION OF MODEL
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OUTLINED AREA ENCOMPASSES
CLEANUP LEVELS FOR EACH
CONSTITUENT
FIGURE 4-2B
ALTERNATIVE B
PLUME MIGRATION
INTERMEDIATE AQUIFER
PREPARED FOR
FIRESTONE TIRE & RUBBER CO.
AKRON. OHIO
INTERNATIONAL
I TECHNOLOGY
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-------
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-------
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ALTERNATIVE C
1/89
10/89
1/90
4/90
7/90
0
PLUME MIGRATION
INTERMEDIATE AQUIFER
10/90
PLAN LOCATION OF MODEL
AREA SEE FIGURE 4-1
OUTLINED AREA ENCOMPASSES
CLEANUP LEVELS FOR EACH
CONSTITUENT
FIGURE 4-3B
ALTERNATIVE C
PLUME MIGRATION
INTERMEDIATE AQUIFER
PREPARED FOR
FIRESTONE TIRE & RUBBER CO.
AKRON. OHIO
, INTERNATIONAL
TECHNOLOGY
I CORPORATION
-------
0= '
0S"
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FORMER
FIRESTONE
FACILITY
n
FIGURE
EQUIPOTENTIAL LINES
850-GPM CAPTURE ZONE
INTERMEDIATE AQUIFER
*'ID»f »•*•»
FIRESTONE TIRE 8 RUBBER CO
AKRON, OHIO
Civatlng a Sa)«t Tomorrow
-------
FLOWUNES
850-CPM CAPTURE ZONE
INTERMEDIATE AQUIFER
ronnfR FIHE3TONE FACILITY
SALINAS. CALIFORNIA
TARGET CLEANUP AHCA
JANUAMT III!
FIRESTONE TIRE 8 RUBBER CO
4KRON. OHIO
FLOW DIRECTION
-------
FLOWLINES
400-GPM CAPTURE ZONE
INTERMEDIATE AQUIFER
FORMER FIRESTONE FACILITY
SALINAS. CALIFORNIA
TARGET CLEANUP AREA
JANUARY 1>lt
FIRESTONE TIRE 8 RUBBER CO
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FLOW 01 DECT I ON
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ALTERNATIVE D
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NOTE:
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OUTLINED AREA ENCOMPASSES
CLEANUP LEVELS FOR EACH
CONSTITUENT
FIGURE -I 6A
ALTERNATIVE D
PLUME MIGRATION
SHALLOW AQUIFER
PREPARED FOR
FIRESTONE TIRE & RUBBER CO.
AKRON. OHIO
I INTERNATIONAL
TECHNOLOGY
CORPORATION
-------
ALTERNATIVE D
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1/90
4/90
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NOTES:
OUTLINED AREA ENCOMPASSES
CLEANUP LEVELS FOR EACH
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FOH PLAN LOCATION OF MODEL
AREA SEE FIGUF1E 4 1
PUMPING RATE 650 qprn
STAHT OF PUMPING
OCTOBER t989
ALTERNATIVE D
PLUME MIGRATION
INTERMEDIATE AQUIFER
PREFAHED FOH
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-------
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INTERMEDIATE AQUIFER
NQLES:
500 1000 FT
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CLEANUP LEVELS FOR EACH
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FOR PLAN LOCATION OF MODEL
AREA SEE FIGUHE -1-1
PUMPING RATE t.50 ypm •
STA'tT OF PUMPING
APHIL 1990
FIGURE 4 -6C
ALTERNATIVE D'
PLUME MIGRATION
INTERMEDIATE AQUIFER
PREPARES COR
FIRESTONE TIRE 8, RUBBER CO.
AKRON, OHIO
INTERNATIONAL
TECHNOLOGY
CORPORATION
-------
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10
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1/89
ALTERNAHVE D (400 gpm)
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1/90
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\
PLUME MIGRATION
INTERMEDIATE AQUIFER
NOTES
OUTLINED AREA ENCOMPASSES
CLEANUP LEVELS FOR EACH
CONSTITUENT
FOH PLAN LOCATION OF MODEL
AREA SEE FIGURE -4 1
START OF PUMPING
OCTOBER 1989
FIGURE 4 6D
ALTERNATIVE D 1400 gpml
PLUME MIGRATION
INTERMEDIATE AQUIFER
PBEPAHED FOR
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AKRON. OHIO
INTERNATIONAL
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OUTLINED AHEA ENCOMPASSES
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CONSTITUENT
FIGUME J -7A
ALTERNATIVE E
PLUME MIGRATION
SHALLOW AQUIFER
PREPARED FOB
FIRESTONE TIRE S RUBBER CO.
AKRON. OHIO
INTERNATIONAL
TECHNOLOGY
CORPORATION
-------
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-1
OUTLINED AREA ENCOMPASSES
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FIGURE -I 7B
ALTERNATIVE E
PLUME MIGRATION
INTERMEDIATE AQUIFER
PREPARED FOR
FIRCSTQNE TIRE 3. RUBBER CO.
AKRON, OHIO
INTERNATIONAL
TECHNOLOGY
CORPORATION
-------
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IX
215 Fremont Street
San Francisco. Ca. 94105
MEMORANDUM
SUBJECT:
TO:
THRUT
FROM:
DATE:
Adjustment of Risk Values and
Recommendation for
Groundwater Cleanup Levels
at Firestone Salinas
Alexis Strauss, Chief
Superfund Enforcement Branch
Betsy Qjfnow, Chief
Enforcement Programs Section
Jeff Dhont . ^
Remedial Proje€t'Manager
Firestone Salinas Site
June 20, 1989
Purpose
The purpose of this memorandum is. to
explain certain adjustments which were
made in risk calculations for the Firestone
Salinas Site, and to provide a rationale for
selection of groundwater cleanup levels at
the Site.
Recommendation
This memorandum will recommend
that the cleanup levels established in the
draft RAP be accepted as protective and in
accordance with ARARs, provided that the
cleanup level for 1,1-DCA is lowered from
20 ppb to 5 ppb.
Introduction to Background and Issues
Firestone submitted a final draft FS/RAP
to DHS on June 5, 1989. The RAP sets
cleanup levels for the groundwater
remediation effort at the Site, based on
both risk and ARARs. To be able to ad-
dress these proposed cleanup levels, EPA
has had to perform three tasks:
1) Make adjustments and correct certain
errors in the manner in which risk cal-
culations were made for the Site;
2) Address the issue of whether 1,1-DCE
is to be treated as a carcinogen in the
quantitative risk assessment;
3) Firestone used a rather unusual
method for arriving at the cleanup levels.
EPA must compare the results of
Firestone's method with the results that
would be obtained by EPA's method and
-------
- 2 •-
decide whether the proposed cleanup
levels are acceptable from the EPA
standpoint.
Note that the computation of cleanup
levels is a related yet somewhat separate
issue from the calculation of risk actually
posed by the site. A quantitative risk as-
sessment was performed to determine, un-
der a probable worst-case, scenario, what
the risk would be from the site. This as-
sumed that the concentration that people
would be drinking for a seventy-year
lifetime is a geometric mean of the con-
centrations found in affected wells.
With regard to cleanup levels, however,
we are calculating the risks which would
exist if concentrations were brought to the
cleanup levels themselves. Rather than as-
sessing exposure based on a geometric mean
over affected wells, it is assumed that
people are exposed to water at the cleanup
levels themselves. In other words, it is as-
sumed that each well constitutes a point of
compliance and must meet the cleanup
level requirement.
Each of the above three issues will now
be discussed in turn.
Adjustments in Calculations
The following adjustments and recal-
culations were required in order to assess
the appropriateness of the proposed
cleanup levels:
1. Certain values for cancer potency
factors had been updated without
Firestone's knowledge. Recalcula-
tion was required using the new
CPF values.
2. Noncarcinogenic effects of car-
cinogens had not been included in
the calculation of the original site
risk. When these were included and
a new hazard index computed for
the site, the HI was still insig-
nificant (< 0.01), and so it became ap-
parent that the cancer risk would drive
the cleanup level selection.
3. 1,1-DCA had not been treated by Fires-
tone as a carcinogen. Recalculations
were required which incorporated 1,1-
DCA in the cancer assessment.
4. Firestone had not considered inhala-
tion exposure in its risk calculations.
Primarily at issue here was the inhala-
tion of volatile organics by persons
while in the shower. A standard es-
timation was used, which has been
used by EPA while awaiting the results
of indoor shower inhalation studies.
This is that the exposure to chemicals
by inhalation, i.e. the dose, is equal to
the exposure from ingestion of drink-
ing water. Making this assumption
does not merely double the risk be-
cause cancer potency factors for in-
halation may vary from those for in-
gestion. Thus, a separate inhalation
risk calculation must be made and
added to the ingestion risk to obtain
the total risk.
1,1-Dichloroethylene as a Carcinogen
1,1-Dichloroethylene (1,1-DCE) is cur-
rently the primary contaminant at Fires-
tone. In all likelihood, if its concentration
were reduced by remediation to the Action
Level of 6 ppb, all other contaminants
would be non-detectable. At issue is
whether it is appropriate to treat 1,1-DCE
in a quantitative risk assessment, or to base
its cleanup on ARARs. Upon review with
Regional Toxicologist Gerald Hiatt and
discussion with DHS toxicologists, the fol-
lowing points and recommendation have
emerged with regard to this issue.
1,1-DCE is a Class C Agent, "Possible Car-
cinogen" (as distinguished from chemicals
classified as Class A, "Known Human
Carcinogens", or Class B, "Probable Human
Carcinogens"). EPA's practice with respect
to risk assessment and setting cleanup
-------
- 3 -
levels is to treat Class C Agents on a case-
by-case basis, using either a modified-RfD
approach or a quantitative risk assessment.
The modified-RfD approach is similar to
the RfD calculation normally used for
non-carcinogens; additional safety factors
are introduced to take into account the car-
cinogenic potential of Class C agents and
the possibility of multiple routes of ex-
posure to the chemical. This approach is
often used by EPA's Office of Drinking
Water (ODW) in setting MCLGs; accord-
ingly, when used it generally results in
cleanup numbers based on ARARs. The
use of the approach is particularly ap-
propriate for those Class C agents where
the evidence for carcinogenicity is espe-
cially weak. In such cases, the use of quan-
titative cancer risk assessment can produce
less useful or even misleading results.
For 1,1-DCE in groundwater, the avail-
able data support the use of the modified-
RfD approach to setting cleanup levels.
The number of negative cancer studies on
1,1-DCE is notable. Five oral car-
cinogenicity studies have been conducted
on 1,1-DCE, including a lifetime joint
study by the National Cancer Institute and
the National Toxicology Program. All of
these oral cancer studies were negative.
Eleven studies on 1,1-DCE evaluated car-
cinogenic potential via inhalation; ten were
negative. One study, by Maltoni, did
produce evidence of carcinogenic potential
in mice, although this interpretation is
blurred somewhat by lack of a clear dose-
response relationship. A similar study by
the same group of investigators did not
produce cancer in rats, even though doses
of up to six-fold higher were administered.
Thus, the evidence supporting classifica-
tion of 1,1-DCE as a "carcinogen" are espe-
cially weak.
At Firestone, if 1,1-DCE is treated as a
carcinogen in a quantitative risk assess-
ment, rather than using the modified-RfD
approach, then at the DHS Action Level of
6 ppb it will single-handedly put the risk
for the site at greater than 3.5E-4. In order
to bring the risk below l.OE-4, the cleanup
level for 1,1-DCE would have to be set at 1
ppb or less.
After reviewing this issue and consulting
with Gerald Hiatt, I recommend that 1,1-
DCE be removed from the quantitative
cancer risk calculation, and that its DHS
Action Level of 6 ppb (the EPA MCL is
7 ppb) be considered protective. This is in
accordance with ODWs decision to use
qualitative rather than quantitative risk as-
sessment in setting the MCLG (MCL and
MCLG are equal for 1,1-DCE) for this
chemical.
In the risk calculations which follow, it is
assumed that all wells at Firestone will
meet the DHS Action Level of 6 ppb for
1,1-DCE, and that this will be considered
protective. Accordingly, 1,1-DCE is not in-
cluded in the risk calculations.
Firestone's Method of Cleanup Level
Derivation
Protectiveness of Proposed Cleanup Levels
In determining the proposed cleanup
levels, Firestone determined the l.OE-6 can-
cer risk level or each carcinogen as if it
were alone. In other words, sum risk was
not calculated. Then, where the lowest
ARAR for any chemical was lower than
the l.OE-6 risk for that compound, the
ARAR replaced the l.OE-6 level as the
proposed cleanup level. Of course, in
doing this, Firestone had not made any of
the necessary adjustments discussed above,
such as incorporation of inhalation ex-
posure.
Firestone's method bears several dis-
crepancies with standard EPA risk assess-
ment guidelines. However, EPA will accept
risk in the 10 to 10 range when compar-
ing risks against ARARs. Even though
Firestone did not calculate a cumulative
risk in its cleanup level calculation, it did
use a 10 point of departure on each com-
pound. It was therefore possible, regardless
-------
- 4 -
of the nature of Firestone's method, that
the resulting cleanup levels were acceptable
anyway. This potential was assessed and
the results can be seen in the accompanying
Tables.
The Tables show cumulative risks, in-
cluding inhalation exposure and treating
1,1-DCA as a carcinogen. The first Table
computes the excess cancer risk assuming
that all chemicals are present at Firestone's
proposed cleanup levels. The second Table
computes the excess cancer risk assuming
that all the chemicals are present at the
lowest ARAR for each chemical.
PLEASE NOTE that in the first Table,
the proposed cleanup level (PCL) for 1,1-
DCA has been entered as 5 ppb, instead of
Firestone's actual proposed level of 20 ppb.
This is because: 1) DHS has an Action
Level of 5 ppb, and may propose an MCL
of the same in the near future, and 2) if
the level of 1,1-DCA is left at 20 ppb, the
total risk will exceed l.OE-4. It is therefore
assumed that the level for this compound
will be lowered to 5 ppb. From an en-
gineering standpoint, this will make little
difference in remediation, because when
1,1-DCE is reduced to its action level of
6 ppb, 1,1-DCA will remain at levels far
below 5 ppb, barring very unusual cir-
cumstances.
It can be seen from the first Table that
the proposed cleanup levels provide for a
total risk not exceeding 3.3E-S (assuming,
of course, that 5 ppb is used for 1,1-DCA
instead of 20ppb).
In the second Table, it can be seen that
the cleanup levels (except for 20 ppb for
1,1-DCA) are all equal to or lower than the
lowest ARAR for the compound. It caj
also be seen that, even if all the cleanup
levels were raised to the ARARs, the risk
would still be acceptable at 4.1E-4. Thus,
with the exception of 20 ppb for 1,1-DCA,
Firestone's proposed cleanup levels (PCLs)
are protective from a risk standpoint and
meet applicable ARARs. This is true even
though the method, of deriving the cleanup
levels may not have completely conformed
to EPA's method for such computations.
Conclusion
The following is recommended:
1. 1,1-DCE be removed from the quan-
titative (cleanup level) risk assessment
and a level of 6 ppb be considered protec-
tive;
2. the cleanup level for 1,1-DCA be
lowered from 20 ppb to 5 ppb;
3. the cleanup levels proposed by Fires-
tone (except for 1,1-DCA) be considered
protective and in accordance with ARARs
and therefore that EPA concur with their
adoption;
4. the RAP declare that these levels shall
be met in each and every monitoring well
before cleanup can be considered at-
tained.
If the above is adopted, the risks at the
site from groundwater will be acceptable
even though the method Firestone used to
calculate the cleanup levels did not exactly
conform to our method.
-------
FIRESTONE SALINAS SUPERFUND PROJECT
Assessment of Excess Cancer Risk at Prooosed Groundwater Cleanup Levels
CHEMICAL ORAL CPF IHHAL CPF
[CAS NO.]
1 , 2-0 I CHLOROETHANE 9.1E-2 9.1E-2
(1,2-DCA)
(107-06-2J
TRICHLOROETHYLENE 1.1E-2 1.3E-2
(TCE) [79-01-6]
TETRA-
CHLOROETHYLENE 5.1E-2 3.3E-3
(PCE) 1127-18-4]
BENZENE 2.9E-2 2.9E-2
[71-43-2]
1,1-D1CHLOROETHANE 9.1E-2 9.1E-2
(1,1-DCA) [75-34-3]
PROP. DOSE AT D.U. RISK INHAL RISK TOTAL RISK
CLEANUP PCL AT PCL AT PCL AT PCL
LEVEL (mg/kg/day)
(ug/O t*1)
0.5 1.4E-5 1.3E-6 1.3E-6 2.6E-6
3.2 9.1E-5 1.0E-6 1.2E-6 2.2E-6
0.7 2.0E-5 1.0E-6 6.6E-8 1.1E-6
0.7 2.0E-5 5.8E-7 5.8E-7 1.2E-6
5 <*2> 1.4E-* 1.3E-5 1.3E-5 2.6E-5
1 1
TOTAL RISKS AT PROPOSED CLEANUP LEVELS ore====> 1 . 7E - 5 1.6E-5 | 3.3E-S |
I I
CPF = Cancer Potency Factor PCL = Proposed Cleanup Level D.U. = Drinkfng Water INHAL » Inhalation
NOTE; Calculation assumes 70-kg body weight, and ingestion of 2 liters of water per day. over • 70-year lifetime.
<*1>: The dose acquired through ingestion is assumed, for estimation, to be equal to the dose acquired by
inhalation. This has been a standard EPA assumption while indoor inhalation studies are being
performed and confirmed.
I
C*2>: VERY IMPORTANT -- Firestone did not propose 5 ug/l in their FS RAP. The proposed value was 20 ug/l.
This Table assumes that the PCL Will be dropped to 5 ug/l. DHS has an action level of 5, and may
issue an MCL at this level. Also. If the level for 1.1-DCA is left at 20 ug/l. the total risk will
exceed 1 .0E - 4 .
-------
FIRESTONE SALINAS SUPERFUMO PROJECT
Assessment of Excess Cancer Risk at Lowest Groundwater Standards (ARARs)
CHEMICAL ORAL CPF INHAL CPF
[CAS MO.)
»
1 ,2-DICHLOROETHANE 9.1E-2 9.1E-2
(1 ,2 -OCA)
[107-06-21
TRICHLOROETKTLENE 1.1E-2 1.3E-2
(TCE) [79-01-61
TETRA-
CHLOROETHYLENE 5.1E-2 3.3E-3
(PCE) [127-18-41
BENZENE 2.9E-2 2.9E-2
[71-43-21
1 ,1-DICMLOROETHANE 9.1E-2 9.1E-2
| LOU LOU CLASS
IARAR ARAR OF
|ug/l NANE CARC.
I
0.5 CANCL 82
5 NCL B2
5 NCL B2
1 CANCL A
5C*2> A.L. C
DOSE AT D.U. RISK INHAL RISK TOTAL RISI
LOU ARAR AT ARAR AT ARAR AT ARAR
(ug/kg/day)
C*2>
1.4E-5 1.3E-6 1.3E-6 2.6E-6
1.4E-4 1.5E-6 1.8E-6 3.3E-6
1.4E-4 7o1E-6 4.6E-7 7.6E-6
<
2.9E-5 8.4E-7 8.4E-7 L7E-6
'
1.4E-4 1.3E-5 1.3E-5 2.6E-5 '
(1,1-OCA) [75-34-31 j
1
TnYAI'BICVCAYinLfC6TADADC«««a«H9* 9 £ C • C 1TB.C I A { C • C
TU^IALKISKSnlLUWcSIAKAKS •**"***> . . c • * C 9 1 • r t > | H • 1 t 3
I
CPF " Cancer Potency Factor PCL * Proposed Cleanup Level D.U. • Drinking Uater INHAL » Inhalation
NOTE; Calculation assumes 70-kg body weight, and Ingestion of 2 liters of Mater per day, over a 70-y.ear lifetime.
""^^"^ - ^ . ..r"'*' '
{*1>: The dose acquired through Ingestion is assumed, for estimation, to be equal to the dose acquired by
inhalation. This has been a standard EPA assumption while indoor inhalation studies are being
performed nnd confirmed.
{•2>: DHS action level of S ug/l. Expected NCL of 5 ug/l. •
------- |