EPA/ROD/R10-94/078
July 1994
EPA Superfund
Record of Decision:
Teledyne Wah Chang Albany
Site, Millersburg, OR,
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION 10
1200 Sixth Avenue
Seattle. Washington 98101
RECORD OF DECISION
DECLARATION, DECISION SUMMARY,
AND
RESPONSIVENESS SUMMARY
FOR
FINAL REMEDIAL ACTION OF GROUNDWATER
AND SEDIMENTS OPERABLE UNIT
TELEDYNE WAH CHANG ALBANY SUPERFUND SITE
MILLERS BURG, ALBANY
JUNE 10, 1994
-------
-------
SITE NAME AND LOCATION
Teledyne Wah Chang Albany
Millersburg, Linn County, Oregon
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial actions for the Teledyne Wah
Chang Albany Site (Site or TWCA Site), in Millersburg, Linn County, Oregon, which
were chosen in accordance with the requirements of the Comprehensive
Environmental Response, Compensation, and Liability Act of 1986, 42 U.S.C. 999601
et. sea., Pub. L. 99-499 (CERCLA), .and, to the extent practicable, the National Oil and
Hazardous Substances Pollution Contingency Plan, 40 C.F.R. Part 300, Published in
55 Fed. Reg. 8666, et.~, on March 8,1990 (NCP). This decision is based on the
administrative record for the Site.
The State of Oregon concurs with the selected remedy.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from this Site, if not addressed
by implementing the response actions selected in this Record of Decision (ROD), may
present an imminent and substantial endangerment to public health, welfare, or the
environment.
DESCRIPTION OF THE SELECTED REMEDY
The remedial actions described below are the final response actions planned for the
groundwater and sediments operable unit at the Site. Teledyne Wah Chang Albany is
an active operating facility which primarily manufactures zirconium metal from zircon
sands. The processing of the zircon sands generates sludge, waste water, residues
and gases as by-products. The cleanup actions described in this ROD address the
threats to groundwater and sediment posed by radionuclides, metals, polychlorinated
biphenyls (PCBs), methyl isobutyl ketone (MIBK), trichloroethylene,
tetrachloroethylene, 1,1,1-trichloroethane, and other contaminants at the Site.
The selected remedy combines containment, source remediation, and treatment
measures to reduce risks to human health and the environment posed by
contaminated groundwater and sediment at the TWCA Site. The selected remedy
consists of the following:
For Contaminated Groundwater:
.
Remediation of groundwater via groundwater extraction in the Feed
Makeup area and at areas on Site where contaminant concentrations
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noncancer HI of 1 for worker exposure. Extraction shall continue until
contaminant concentrations in groundwater throughout the Site are
reduced to below SDWA MCLs, non-zero MCLGs, or cancer risk levels of
10~ and noncancer risk HI < 1 for worker exposure, or until EPA in
consultation with DEQ determines that continued groundwater extraction
would not be expected to result in additional cost effective reduction in
contaminant concentrations at the Site. Contaminated groundwater in
exceedance of SDWA MCLs, non-zero MCLs, or cancer risk levels of 10~
and noncancer risk HI > 1 for residential use shall be prevented from
migrating off the plant site, or beyond the current boundary of the
groundwater contaminant plume at the Farm Ponds Area.
.
Discharge of extracted groundwater to Teledyne Wah Chang Albany's
wastewater treatment plant. Pretreatment of groundwater to comply with
CWA requirements prior to discharge to the wastewater treatment plant.
.
Treatment or removal of subsurface source material near the Feed
Makeup Building on the main plant.
.
For Contaminated Sediments:
.
Slope erosion protection consisting of a geotextile covered by riprap
placed along the banks of Truax Creek to prevent contaminated fill
material from entering the creek.
.
Removal of approximately 3,600 cubic yards of contaminated sediments
from the surface water bodies adjacent to, or flowing through the Site.
Additional ecological characterization prior to removal to determine
potential impacts of sediment removal to the local ecosystem and to
provide mechanisms to mitigate those impacts.
Site-Wide Actions:
.
Deed restrictions and institutional controls on land and groundwater use
for both the main plant and Farm Ponds area. The objective of this
component of the remedy is to ensure that the property and groundwater
are used only for purposes appropriate to the cleanup levels achieved
.
.
Environmental evaluations of currently uncharacterized potential
contaminant source areas, as needed to ensure achievement of
groundwater RAOs. The objective of this component of the remedy is to
ensure that contaminant source areas do not adversely impact the
remedy.
.
Long-term on-Site and off-Site groundwater, surface water, and sediment
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wells which are in exceedance of MCLs and non-zero MCLGs, cancer
risk levels of 10-6, and noncancer risk HI > 1 for residential exposure.
.
Review of selected remedy at least once every five years to ensure
protection of human health and the environment.
STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the environment, complies with
Federal and State requirements that are legally applicable or relevant and appropriate
to the remedial action, and is cost-effective. This remedy utilizes permanent solutions
and alternative treatment or resource recovery technologies to the maximum extent
practicable, and satisfies the statutory preference for remedies that employ treatment
that reduces, toxicity, mobility, or volume as a princiP?1 element.
Because this remedy will result in hazardous substances remaining on site above
health-based levels, a review will be conducted within five years after commencement
of the remedial action to ensure that the remedy continues to provide adequate
protection of human health and the environment. ,.
JUN J. 0 J99q
Date
~~
Regional A mlmstrator
Environmental Protection Agency
Region 10
. .
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Gregor]
May 24, 1994
Ms. Carol Rushin
Chief, Superfund Remedial Branch
U.S. Environmental Protection Agency
Mail Stop HW-l13
1200 Sixth Avenue
Seattle, Washington 98101
J ~; ~'J -
1 1994
DEPAIUMENT OF
ENVIRONMENTAL
.... . .0: .. 't. ,- ~:.... '.";
. .
QUA LlTY
. ,,,,.:;j :--'L;';::.,:;,~ ~;~i;:.~~:
Re:
Teledyne Wah Chang Albany
Groundwater and Sediments Operable Unit
Record of Decision .
(avO\
Dea~
The Oregon Department of Environmental Quality (DEQ) has reviewed the Record of
Decision, dated May 1994, for the Groundwater and Sediments Operable Unit at the
Teledyne Wah Chang Albany (TWCA) Superfund site. I am pleased to advise you that DEQ
concurs with the remedy selected by EPA (extraction and treatment of groundwater,
treatment or removal of subsurface source material, slope erosion protection and removal of
contaminated sediments, and environ menial evaluations of potential contamination source
areas etc.). I find that this alternati ve is protective, and to the max i mum extent practicable is
cost effective, uses permanent solutions and alternative technologies, is effective and
implementable. Accordingly, it satisfies the requirements of ORS 465.315, and OAR 340-
122-040 and 090.
It is understood that remediation of contaminated soils al the TWCA sile will be addressed in
a subsequent soils operable unit Record of Decision.
If you have any questions concerning this matter, please contact Max Rosenberg of DEQ's
Wc:;:cm Region Cleanup Group at 503-636-7838 ext. 228.
Sincerely,
~
Fred Hansen
Director
PSR:
twcarod. fh
cc:
Howard Orlean, USEPA
Thomas Miller, SRS/DEQ
Kerri Nelson, SRS/DEQ
HII SW Sixth Avcnue
('{Hiland. OR 9720~.1 ~4()
(501) 229.56%
TDD (Sm) 229-699:1
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1.0
TABLE OF CONTENTS
SITE NAME AND LOCATION. . .
. . . . . .
. . . . .
2.0 SITE
2.1
2.2
2.3
3.0 SITE
3.1
3.2
3.3
3.4
3.5
DESCRIPTION. . . . . . . . . . . . . .
Setting. . . . . . . . . . . . . . . . . . . . . .
Topography. . . . . . . . . . . . . . . . .
Land Use. . . . . . . . . . . . . . . . . .
BACKGROUND AND ENFORCEMENT ACTIVITIES. . . .
Site History. . . . . . . . . . . . . . . . . . .
3.1.1 Summary of State and Public Involvement
Regarding the LRSP and Schmidt Lake. . .
Plant Processes. . . . . . . . . . . . . . .
Waste Management Programs. . . . . . . . . . . . .
3.3.1 Process Wastewater Treatment. . . . . .
3.3.2 Lime Solids Storage ("Farm Ponds") ...
3.3.3 Solid Waste Management . . .
3.3.4 Radioactive Waste. . . . . . . . . . . .
Past Remedial and Removal Activities. . . . . . .
3.4.1 Sludge Ponds Operable Unit. . . . . . .
3.4.2 Supplementary Removal Action at Schmidt
Lake. . . . . . . . . . . . . . . . . . .
Soil Removal in Fabrication Area. . . .
Groundwater Extraction in Extraction Area
(Well PW-28A) . . . . . . . . . . . . . .
Enforcement Activities. . . . . . . . . . . . . .
3.5.1 RIfFS Reports Produced by Potentially
Responsible Party Under Consent Order
with EP A . . . . . . . . . . . . . . . .
Major Reports Produced by Teledyne Wah
Chang Albany Under Unilateral Order of
EP A . . . . . . . . . . . . . . . . . . .
Major Reports Prepared and Issued QY
EPA . . . . . . . . . . . . . . . . . . .
3.4.3
3.4.4
3.5.2
3.5.3
5.0
COMMUNITY RELATIONS
.......
4.0
. . .
. . . . .
. . .
SCOPE AND ROLE OF RESPONSE ACTION WITHIN SITE STRATEGY.
6.0 SITE
6.1
6.2
6.3
CHARACTERISTICS. . . . . . . . . . . .
Geology and Soils. . . . . . . . . . . . . .
Hydrogeology. . . . . . . . . . . . . . . . . . .
6.2.1 Main Plant. . . . . . . . . . . . . . .
6. 2 .2 . Farm Ponds. . . . . . . . . . . . . . .
Extent of contamination. . . . . . . . . . .
6.3.1 Farm Ponds Area. . . . . . . . . . . . .
6.3.1.1 Groundwater Contamination at the
Farm Ponds Remedial Sector. . . . .
6.3.2 Extraction Area. . . . . . . . . . . . .
6.3.2.1 Groundwater Contamination at the
Extraction Area. . . . . . . . . .
Fabrication Area. . . . . . . . . . . .
6.3.3
1
1
1
1
1
4
4
6
7
9
9
9
10
10
10
10
14
14
14
19
20
21
21
22
25
26
26
26
26
28
28
28
33
33
33
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7.0
8.0
6.3.3.1
6.4
Groundwater contamination
Fabrication Area . . . .
6.3.3.2 contamination in Truax Fill. . . .
6.3.4 Solids Area. . . . . . . . . . . . . . .
6.3.4.1 Groundwater contamination at the
Solids Area. . . . . . . . .
Addi tional Contaminant Sources in
the Solids Area. . . . . . .
6.3.5 Surface Water Remedial Sector. . .
6.3.5.1 Surface Water Contamination. . . .
6.3.5.3 Sediment Contamination at the
Surface Water Remedial Sector
Transport and Fate of Contaminants . . . . .
6.4.1 Organic Compounds. . . . . . . . . . . .
6.4.1.1 Volatile Organic Compounds (VOCs)
6.4.1.2 Semivolatile Organic Compounds
( SVOCs ) ..............
6.4.1.3 Polychlorinated Biphenyls (PCBs) . .
6. 4 . 2 Metals.................
6.4.3 Radionuclides . . . . . . . . . . . . . .
Potential Health Impacts of Major Contaminants
Found at the TWCA Site. . . . . . . . . . . . . .
at
6.3.4.2
6.5
SUMMARY OF
7.1 Human
7.1.1
7.2
SITE RISKS . . . . . . . . . . .
Health Risks . . . . . . . . . . . . .
Approach to Human Health Risk
Assessment. . . . . . . . . . . .
7.1.2 Contaminants of Concern. . . . . .
7.1.3 Toxicity Assessment. . . . .
7.1.4 Exposure Assessment. . . . . . . .
7.1.5 Risk Characterization. . . . . . .
Environmental Risk Characterization. . . . .
7.2.1 Potential for Exposure and Toxicity to
Ecological Receptors. . . . . . . . . .
Ecological Response Assessment. . . ~ .
Evaluation of Causal Evidence Between
Measured Exposures and Ecological
Responses. . . . . . . . . . . . . . . .
Uncertainty in the Risk Assessment. . . . . . . .
Conclusions. . . . . . . . . . . . . . . . . . . .
7.2.2
.7.2.3
7.3
7.4
DESCRIPTION OF ALTERNATIVES. . . . . . . .
8.1 Alternative 1 - No Further Action. . . . . .
8.2 Alternative 2 Monitoring and Institutional
Controls. . . . . . . . . . . . . . . . . .
8.2.1 . Institutional Controls. . . . . . . . .
8.2.2 Monitoring.........
8.2.3 Estimated Cost. . . . . . . . . . . . .
8.3 Alternative 3 Groundwater Extraction, Slope
Erosion Protection, Institutional Controls and
Moni tor inq . . . . . . . . . . . . . . . . . . . . .
8.3.1 Extraction of Feed Makeup Groundwater. .
8.3.2 Groundwater Extraction at the Farm
Ponds. . . . . . . . . .
........
the
37
42
42
45
45
45
48
48
48
56
56
56
56
56
57
57
59
59
59
60
60
63
67
71
72
72
72
75
76
79
79
91
91
91
92
92
92
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9.0
8.4
8.5
8.6
8.7
Slope Erosion Protection Along the North
Bank of Truax Creek. . . . . . . . . . . 94
8.3.4 Estimated Cost . . . . . . . . . . 97
Alternative 4 Groundwater Extraction, Slope
Erosion Protection, Removal of Hot spot Sediments
in Truax Creek, Insti tutional Controls and
Monitoring. . . . . . . . . . . . . . . . . . . . . 97
8.4 . 1 Groundwater Extraction From Areas
Exceeding 10-4 Health-Based Risk Goals
Sediment Removal from Truax Creek Hot
Spot. . . . . . . . . . . . . . . . . . 99
8.4.3 Estimated Cost. . . . . . . . . . . . . 99
Alternative 5 Groundwater Extraction, Slope
Erosion Protection, Removal of Hot spot Sediments
in Truax Creek, Institutional Controls and
Moni tor ing . . . . . . . . . . . . . . . . . . . . . 99
8.5.1 Groundwater Extraction from Wells
Exceeding 10-05 Health-Based Risk Goal. . 101
8.5.2 Estimated Cost . . . . . . . . . . 101
Alternative 6 Groundwater Extraction, Slope
Erosion Protection, Removal of Hot spot Sediments
in Truax Creek, Removal of Sediments in Surface
Water Remedial Sector, Soil Washing in Feed Makeup
Area, Institutional Controls and Monitoring. ... 103
8.6.1 Groundwater Extraction From Areas
Exceeding Risk Goals or ARARs . . . . . . 103
Removal and Disposal of PCB-Contaminated
Sediments. . . . . . . . . . . . . . . . 106
In Situ Flushing of Source Material at
Feed Makeup (PW-28A) . . . . . . . 106
8.6.4 Estimated Cost. . . . . . . . . . . . . 109
Alternative 7 Source Reduction, Groundwater
Extraction, Slope Erosion Protection, Removal of
Sediments in Portions of Surface Water Remedial
Sector, Flushing of Source Material in the Feed
Makeup Area, stringent Institutional Controls and
Monitoring. . . . . . . . . . . . . . . . . . . . . 109
8.7.1 Source Reduction. . . . . . . . . . . . 109
8.7.2 Pretreatment of Groundwater. . . . . . . 110
8.7.3 Supplemental Source Evaluation at Feed
Makeup Area. . . . . . . . . . . . . . . 110
Environmental Evaluation of
Un investigated Areas. . . . . . . . . . 111
Off-Site Groundwater Monitoring. . . . . 111
Estimated Cost . . . . . . . 112
8.3.3
8.4.2
8.6.2
8.6.3
8.7.4
8.7.5
8.7.6
97
COMPARATIVE ANALYSIS OF ALTERNATIVES. . . . . . . . . . 113
9.1 Threshold Criteria. . . . . . . . . . . . . . . . 113
9.1.1 Overall Protection of Human Health and
the Environment. . . . . . . . . . . . . 113
Compliance with ARARs . . . . . . . 115
Balancing criteria . . . . . . 116
Long-Term Effectiveness and Permanence. 116
9.2
9.1.2
Primary
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10.0
11. 0
12.0
9.2.2 Reduction of Toxicity, MObility, or
Volume Through Treatment . . . . . 117
9.2.3 Short-Term Effectiveness . . . . . . . . 118
9.2.4 Implementability . . . . . . . . . 119
9.2.5 Projected Costs . . . . 119
9.3 Modifying Criteria . . . . . . . . . . . . . 120
9.3.1 State Acceptance . . . . . . . . . 120
9.3.2 Community Acceptance . . . . . . . 121
SELECTED REMEDY. . . . . . . . . . . . . . . . .
10.1 Contaminated Groundwater. . . . . . . .
10.1.1 Groundwater Extraction and Containment
10.1.1.1 Point of Compliance for Groundwater
Remediation. . . . . . . . . . . . 128
10.1.1.2 Attainment of Groundwater Cleanup
Levels. . . . . . . . . . . . . . . 130
10.1.1.3 Groundwater Extraction System
Monitoring. . . . . . . . . . . . . 132
10.1.1.4 Decision to Modify Groundwater
Remedial Actions. . . . . . . . . . 133
Pretreatment and Discharge of Extracted
Groundwater. . . . . . . . . . . . . . . 133
Removal/Treatment of Subsurface Source
Material Near the Feed Makeup Building. 135
10.2 Contaminated Sediment. . . . . . . . . . . . . . . 136
10.2.1 Slope Erosion Protection Along the Banks
of Truax Creek. . . . . . . . . . . . . 136
Sediment Removal. . . . . . . . . . . . 137
Actions. . . . . . . . . . . . . . 139
Deed Restrictions and Institutional
Controls. . . . . . . . . . . . . 139
Environmental Evaluations of
Uninvestigated Areas. . . . . . . . . . 139
Long Term On-Site and Off-Site
Groundwater, Surface Water and Sediment
Monitoring. . . . . . . . . . . . 140
10.3.4 CERCLA Five-Year Review. . . . . . . . . 140
10.4 Costs. . . . . . . . . . . . . . 141
. . . 122
. . 124
. 124
10.1.2
10.1.3
10.2.2
10.3 Site-Wide
10.3.1
10.3.2
10.3.3
STATUTORY DETERMINATIONS. . . . . . . . . 143
11.1 Protection of Human Health and the Environment. . 143
11. 2 Compliance with Applicable or Relevant and
Appropriate Requirements (ARARs) ......... 144
11.3 Cost Effectiveness. . . . . . . . . . . . . . . . 149
11.4 Utilization of Permanent Solutions and Resource
Recovery Technologies to the Maximum Extent
Practicable. . . . . . . . . . . . . . . . . . . . 149
Preference for Treatment as a Principal Element. . 150
Community Acceptance- . . . . . . . . . . . . 150
Conclusions. . . . . . . . . . . . . . . . . . . . 151
11.5
11. 6
11.7
DOCUMENTATION OF SIGNIFICANT DIFFERENCES
12.1 Groundwater Extraction. . . . . . . . . . . . .
12.1.1 Determination of Achievability of Cleanup
. 153
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12.2
12.3
12.4
.12.5
Levels. . . . . . . . . . . . . . . . . 154
Pretreatment of Groundwater. . . . . . . . . . . . 155
Deferral of Surface and Subsurface Soil Remediation
to a Subsequent Operable Unit ROD. . . . . . . . . 156
Environmental Evaluations of Previously
Uninvestigated Areas. . . . . . . . . . . . 156
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Fiqure
2-1
3-1
3-2
3-3
3-4
6-1
6-2
6-3
6-4
6-5
6-6
6-7
6-8
8-1
8-2
8-3
8-4
8-5
8-6
8-7
8-8
LZS'1' OF FZGURES
Location Map
.......
Areas Used for Past Waste Disposal
. . . . .
Zirconium Manufacturing Process.
Location of Boring B91-S
. . . .
. . . . . .
Location of Monitoring Well PW-28A
........
Conceptual Hydrogeologic Model
. . . . .
. . . . .
Main Plant Area - Conceptual Hydrogeologic Cross
Section. . . . . . . . . . . . . . . . . . . . . .
Farm Ponds Area - Conceptual Hydrogeologic Cross
Section. . . . . . . . . . . . .
Remedial Sectors
. . . . .
Farm Ponds and Soil Amendment Area
. . . .
. . . .
Main Plant Area Contaminant Source Areas -
Excluding the Solids Area. . . . . . . . . .
Solids Area Source Locations
. . . .
. . . .
Total PCBs in Sediment
. . . . . .
. . . .
. . . .
Extent of Groundwater Contamination at the Feed
Makeup Area. . . . . . . . . . . . . . . . . . . .
Extent of Groundwater Contamination at the Farm
Ponds Area . . . . . . . . . . .
Slope Erosion Protection of Truax Fill
. . . . . .
Groundwater Extraction from Wells Exceeding 10-4
Risk Levels. . . . . . . . . . . . . . . . .
TC-5 Sediment Removal Location
. . . . . .
Groundwater Extraction from Wells Exceeding 10-5
.Risk Levels. . . . . . . . . . . . . . . .
Schematic Flow Diagram of V2 Treatment System. . . 107
Affected Areas and Estimated Volume of Sediment. . 108
~
2
5
8
15
16
27
29
30
31
32
36
44
51
93
95
96
98
. 100
-------
Fiqure
10-1
10-2
10-3
Paqe
Identified Hot Spots or Source Areas of
Groundwater Contamination Which Exceeds Lifetime
Cancer Risk Levels of 10-4 and/or Substantially
Exceeds Lifetime Noncancer Hazard Index of 1 " " " 125
Point of Compliance for Main Plant Groundwater
Remediation" " ". " " " . . . " . . " .
" " " 129
Areas of Sediment Removal.
. . . . .
" . 138
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6-5
6-6
6-7
7-1
7-2
7-3
7-4
7-5
8-1
8-2A
8-2B
8-3
9-1
10-1
Table
3-1
3-2
6-1
6-2
6-3
6-4
LIST OF TABLES
Process Wastes Generated at TWCA
. . . . .
. . . .
Well PW-28A Groundwater Analytical Results
Summary. . . . . . . . . . . . . . . . . .
. . . .
Farm Ponds Area Groundwater Analytical Results
Summary. . . . . . . . . . . . . . . . . . . . . .
Extraction Area Groundwater Analytical Results
Summary. . . . . . . . . . . . . . . . . . . . . .
Fabrication Area Groundwater Analytical Results
Summary. . . . . . . . . . . . . . . . . . . . . .
Detected Contaminants in Truax Creek Fill.
. . . .
Solids Area Grou~dwater Analytical Results
Summary . . . . . . . . . . . . . . . .
Surface Water Analytical Results Summary
. . . . .
Identification of Potential Source Areas
. . . . .
Chemicals of Potential Concern in Groundwater and
Selection Criteria. . . . . . . . . . . . . . . .
Toxicity Factors
. . . . .
. . . . .
. . . .
Exposure Assumptions for Groundwater Pathways. . .
Summary of Sample-Specific Risks for Groundwater
Comparison of Field or Lab-Derived Ecological
Measurements with Exposure Estimates for
Polychlorinated Biphenyls and Hexachlorobenzene . .
Elements of TWCA Site Cleanup Alternatives
. . . .
Federal Chemical~, Location-, and Action-Specific
ARA.Rs . . . . . . . . . . . . . . . . . . . . . . .
State of Oregon Chemical-, Location-, and Action-
Specif ic ARA.Rs . . . . . . . . . . . . . . .
Monitoring Wells Exceeding Risk Values or ARA.Rs . . 104
Glossary of Evaluation criteria
. . . . .
. . 114
Cleanup Levels for Ground Water at the TWCA Site
Paqe
11
17
34
38
40
43
46
49
52
61
64
68
70
73
80
81
88
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Table
10-2
10-3
Paqe
Oregon Water Quality criteria for Selected Contaminants
a t the TWCA Site. . . . . . . . . . . . . . . . . 134
.
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1.0 SITE NAME AND LOCATION
Teledyne Wah Chang Albany
Millersburg, Oregon
2.0 SITE DESCRIPTION
2.1
Setting
The Teledyne Wah Chang Albany Site (Site or TWCA Site) is located in Millersburg,
Oregon, an industrial-based community two miles north of downtown Albany (Figure
2-1). The Site is approximately 20 miles south of Salem, 65 miles south of Portland,
60 miles east of the Pacific Ocean, and adjacent to the Willamette River. Portions of
the TWCA Site are within the river's 100-year and SOD-year flood plains.
The TWCA plant is bounded on the east by Old Salem Road and Interstate 5 (1-5).
The land east of the plant is used mainly for residential and commercial purposes.
The land west of the Willamette River, which forms the western boundary of the plant,
is used for agriculture. The land surrounding the Farm Ponds Area to the north of the
main plant is also used for agricultural purposes.
The city of Albany had a population of approximately 29,000 in 1990; Millersburg had a
population of about 700 people.
The TWCA Site is located within an area that is zoned for heavy industry. Industrial
facilities closest to the TWCA Site include; a particle board plant, a resin plant, a wood
flour processing plant, and a closed plywood mill.
2.2
Topography
TWCA is located within the broad and relatively flat Willamette Valley which was
formed by the Willamette River as it meandered back and forth between the Coast
Range mountains to the west and the Cascade Mountains to the east. The ground
surface in the vicinity of TWCA slopes westward towards the river with a gradient of
approximately 11 feet per mile.
2.3
Land Use
The TWCA Superfund site includes the 110 acre main plant and the 115 acre area
known as the farm s~e (Farm Ponds area). The main plant is organized into the
following areas; the Extraction Area (south of Truax Creek), the Fabrication Area
(north of Truax Creek), and a Solids Storage Area west of the Burlington Northern
Railroad. The farm site contains the plant's wastewater treatment ponds (Farm
Ponds) and is located approximately 3/4 mile north of the main plant (Figure 2-1).
-------
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-------
The Farm Ponds area includes four 2-1/2 acre solids storage ponds in addition to the
Soil Amendment Area. The Soil Amendment Area has been primarily used in the past
for agriculture.
-------
3.0 SITE BACKGROUND AND ENFORCEMENT ACTIVITIES
3.1
Site History
Operations at the TWCA Site began in 1956 when, under contract with the U.S. Atomic
Energy Commission, Wah Chang Corporation reopened the U.S. Bureau of Mines
Zirconium Metal Sponge Pilot Plant. Construction of new facilities, at the location of
the existing plant, began in 1957. These facilities were established primarily for the
production of zjrconium and hafnium sponge; however, tantalum and niobium pilot
facilities were also included. Melting and fabrication operations were added in 1959.
TWCA was established in 1967 after Teledyne Industries, Inc., purchased the Wah
Chang Corporation of New York. In 1971, the plant became a separate corporation,
Teledyne Wah Chang Albany.
Beginning in 1957, waste materials from TWCA's processes were placed in unlined
ponds on the facility. Examples of unlined ponds used for disposal of waste sludges
and other materials in the past include Arrowhead Lake, V-2 Pond, Chlorinator
Residue Pile, Magnesium Resource Recovery Pile, Schmidt Lake, and the Lower River
Solids Pond (LRSP) (Figure 3-1).
From 1972 until 1978 chlorinator residues from TWCA's sand chlorinator process were
placed in a separate pile north of Schmidt Lake. This practice was discontinued in
1978, when the contents of the pile were removed and transported off Site to a
permitted low level radioactive waste disposal facility.
Solid residues generated during the development and operation of nonferrous metals
manufacturing processes at the plant site were placed in a resource and recovery pile.
The major material placed in the pile was magnesium chloride. From 1983 through
1988 TWCA recovered material from this pile to produce magnesium oxide for use in
its ongoing processes.
The V-2 Pond was used for temporary storage and pretreatment of primarily hydrous
metal precipitate and un reacted lime solids. The use of this pond was discontinued in
1979. The V-2 Pond was emptied in 1989 and the solids were removed to the Farm
Ponds Area where they are currently stored under cover on a concrete pad awaiting
approval for processing or disposal. Confirmatory soil sampling of the pond was
conducted in late 1991 and early 1992. The V-2 Pond is currently being filled with
gravel and soil. Purchased gravel was placed and compacted into the V-2 Pond and
the remaining fill is IT!ade up of excavated materials from around the plant.
The unlined sludge ponds have attracted the attention of regulatory agencies (U.S.
Environmental Protection Agency (EPA) and Oregon Department of Environmental
Quality (DEQ» and the public for many years, particularly because of the presence of
-------
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AREAS USED FOR PAST I
-------
radioactive materials, which was first confirmed by the Oregon State Health Division in
1977. Waste sludges (lime solids) generated prior to 1979 were contained in the
LRSP, Schmidt Lake, Arrowhead Lake, and the V2 Pond. Much of the public concern
has focused on the LRSP and Schmidt Lake because of their proximity to the
Willai'nette River. A summary of the history of state and public involvement regarding
the LRSP and Schmidt Lake is given below in Section 3.1.1.
Some of the solids generated prior to 1976 were used as a beneficial soil amendment
on the TWCA farm site. In 1978 TWCA changed it's production process which
reduced the amount of radioactive materials in the lime solids. Ume solids generated
after 1979 are now contained in 4 unlined ponds located in the Farm Ponds Area.
Concerns that the unlined sludge ponds were located in the Willamette River
floodplain, and that hazardous materials from the sludge ponds would migrate to soil,
surface water, and groundwater, led to the TWCA facility being proposed for inclusion
on the National Priorities Ust (NPL) in December of 1982. The TWCA Site was placed
on the NPL in October 1983.
3.1.1 Summary of State and Public Involvement Regarding the LRSP and
Schmidt Lake
.
Prior to the TWCA Site being proposed for inclusion on the NPL, in June 1982,
TWCA submitted an application to the Energy Facility Siting Council of the State
of Oregon (EFSC) for a site certificate to remove approximately 120,000 cubic
yards of sludge from the LRSP and Schmidt Lake to an area outside of the 100-
year floodplain.
.
After a series of public hearings, the EFSC denied TWCA's site certificate
application in December 1982. This denial was in part due to public concerns
regarding geologic standards for the proposed new sludge ponds loca~on.
.
TWCA appealed the decision of EFSC to the Oregon Supreme Court in
February 1983.
.
During the 1983 Oregon State Legislative Session, a bill was introduced which
woul9 impose new stringent geological standards on site certificates. The bill
died in committee but it became a ballot measure which would be voted on by
the Oregon voters.
.
In November 1984. the ballot measure was passed by the Oregon voters.
.
In December 1984, the Oregon Supreme Court remanded the site certificate
matter back to the EFSC.
-------
.
During the 1985 Oregon State Legislative Session, a bill was introduced to lower
the threshold levels of radioactivity for site certificates. This bill failed on the
Oregon State Senate floor, but was introduced as a public initiative petition
(ballot measure). This ballot measure was defeated by the voters in the
November 1986 election.
.
In March 1987, EFSC concluded that the sludges in the LRSP and Schmidt
Lake were not subject to their jurisdiction.
.
In May 1987, TWCA proposed a LRSP and Schmidt Lake closure plan to the
Oregon State Health Division.
.
In June 1987, EPA and DEQ recommended that no closure of the LRSP and
Schmidt Lake be performed until after conclusion of the Superfund remedial
investigation.
3.2
Plant Processes
TWCA is an active, operating, producer of zirconium metal. Zircon sand, the principal
ore, is generally imported from Australia. A schematic diagram showing TWCA's
process for producing zirconium and hafnium is shown in Figure 3-2.
Zircon sand (zirconium orthosilicate) is concentrated by gravity, electrostatic, and
magnetic methods to remove all but a small amount of impurities before being shipped
to the TWCA facility. Zircon sands typically contain small amounts of radioactive
elements such as uranium and thorium which are concentrated during the TWCA
production process. In addition,. the zircon sands will contain 1 to 5 percent hafnium
which becomes a co-product with zirconium.
The zircon concentrate is combined with petroleum coke, and mixed in a ball mill
before feeding to a chlorination reactor where at high temperatures the zirconium
orthosilicate is converted to zirconium-hafnium tetrachloride and silicon tetrachloride.
The hafnium and zirconium are separated by mixing the zirconium-hafnium
tetrachloride with methyl isobutyl ketone (MIBK), containing ammonium thiocyanate.
This portion of the process separates the hafnium into an organic phase and the
zirconium into an aqueous phase. Hafnium is removed from the organic phase by
stripping with sulfuric acid, and then it is formed into a solid by precipitation with
ammonium hydroxide. The precipitate is filtered and heated to form hafnium oxide.
Zirconium is remove~ from the aqueous phase by precipitation with sulfuric acid. The
zirconium precipitate is also filtered and heated to form zirconium oxide. MIBK and
ammonium thiocyanate are purified and recycled.
The zirconium and hafnium oxides follow similar paths to metal production. Zirconium
oxide is mixed with petroleum coke and fed to a chlorination reactor to form zirconium.
-------
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-------
tetrachloride. Elemental magnesium is then reacted with the zirconium tetrachloride to
form a sponge-like material consisting of magnesium chloride and zirconium. The
magnesium chloride is physically removed from the zirconium sponge and sold as a
byproduct. The zirconium sponge is consolidated into ingots by first crushing,
blending and pressing the sponge into briquettes. The briquettes are then welded
together with an electron beam to form an electrode which is melted and cast into
homogenized ingots in a vacuum arc furnace. The cast zirconium ingots are then
fabricated into numerous shapes and forms such as forgings, plate, sheet, foil, tubing,
rod, and wire. The fabrication process can involve caustic cleaning, degreasing,
and/or pickling.
3.3
Waste Management Programs
Waste management programs at the TWCA facility include a wide range of activities
because of the many processes involved in the production of zirconium, hafnium, and
other metals. These activities include process wastewater treatment, lime solids
storage, solid waste management, and radioactive waste management.
3.3.1 Process Wastewater Treatment
The TWCA facility's central wastewater treatment system consists of a continuous
chemical precipitation and sedimentation system. Metals removal is accomplished by
neutralization with lime, magnesium hydroxide, or sulfuric acid and carbon dioxide to
pH 6 to 9 to form metal hydroxides and sulfates. Fluorides are removed prior to
neutralization in a fluoride treatment facility which began operating in March 1989.
After neutralization, the precipitated metals and lime solids are removed in a clarifier by
settling. These solids, referred to as .sludge., are then piped as a slurry of two to five
percent solids to the lime solids storage ponds for additional settling and dewatering.
Return flow from the lime solids storage ponds is sent to the wastewater treatment
system. Effluent from the wastewater treatment plant is regulated by DEQ and is
currently discharged to Truax Creek under a National Pollutant Discharge Elimination
System (NPDES) wastewater discharge permit.
3.3.2 Ume Solids Storage (-Farm Ponds.)
Ume solids (sludge) generated from the wastewater treatment facility are presently
stored in four surface impoundments located in the farm site area approximately 3/4
mile north of the maifl plant. These ponds were placed in operation in 1979 and are
presently regulated under TWCA's existing NPDES permit.
The ponds are filled with approximately 5 to 7 feet of solids and are constructed with a
soil-bentonite liner. The ponds receive a slurry of 2 to 5 percent solids from the
wastewater treatment plant via a pipeline. The slurry enters the ponds on the south
-------
end. As the water velocity slows in the ponds the solids settle to the bottom where
they remain. Any removal and disposal of the solids is regulated under the NPDES
permit. Solids-free liquid is decanted from the north end of the ponds and then piped
back to the main plant's wastewater treatment system.
3.3.3 Solid Waste Management
Solid waste management programs at TWCA have been designed to comply with the
requirements of the Resource Conservation and Recovery Act (RCRA) and the Toxic
Substances Control Act (TSCA). lhese programs include procedures for; (1)
management and disposal of brand-name products and items used on the plant site,
(2) management and disposal of solid wastes generated by various process
operations, and, (3) management of transformers and capacitors containing
polychlorinated biphenyls (PCBs).
Materials are initially delivered to a centralized area on the main plant known as the
-dumpmaster" area if they are intended for transportation to and disposal at a public
landfill or at a hazardous waste, treatment, storage or disposal facility. Nonhazardous
material is inspected by the operator of this area to make sure it does not contain any
items prohibited from disposal in a public landfill by federal and state law. Table 3-1
lists process wastes presently generated on a routine basis at TWCA.
3.3.4 Radioactive Waste
In March 1978, a Naturally Occurring Radioactive Materials (NORM) license was
granted to TWCA to transfer, receive, possess and use zircon ~ands and industrial
byproducts containing licensable concentrations of radioactive material. TWCA
currently disposes of its radioactive waste material at the U.S. Ecology low Level
Radioactive Waste Site located on the Hanford Reservation in Washington and
operates under the provisions set forth in the 1978 NORM license.
3.4
Past Remedial and Removal Activities
3.4.1 Sludge Ponds Operable Unit
The LRSP and Schmidt Lake lie adjacent to each other in the western portion of the
TWCA Site, next to the east bank of the Willamette River, between Murder Creek to
the north and Truax 9reek to the south (Figure 3-1).
-------
Generating Process Waste Characteristic Management
Option
1. Zirconium and Hafnium
Manufacturing
a. Sand Chlorination Sand Chlorinator Residues Radioactive Radioactive
Waste Disposal
Facility
Sand Chlorinator Residues Nonhazardous Onaite Corrosive
Neutralization
Tank
b. Saparations MIBK Still Bottoms Uranium Ignitable Hazardous
Waste
Incinerator
Removal Treatment System Radioactive Radioactive
Solids Waste Disposal
Site
c. Pure Chlorination Pure Chlorinator Residues Nonhazardous Onaite Corrosive
Neutralization
Tank
Pure Chlorination Residues Radioactive Radioactive
Waste Disposal
Facility
Recycled Oxide Chlorinator EP Toxic (0008) Hazardous
Residue Waste Disposal
Facility
d. Reduction MgCI2 Wastes Fire Hazard Beneficial Use
of Mg as
Magnesium
Hydroxide
Slurry Oxidation
of Metal Fines in
Smokehouse
Smokehouse Material Nonhazardous Public Waste
(Nonhazardous) Disposal Facility
Smokehouse Material EP Toxic (0008) Hazardous
(Hazardous) Waste Disposal
Facility
Stainless Steel Uners Nonhazardous Metaf Recycle
Facility
2. Niobium Manufacturing Nb Thermite Slag EP Toxic (0005) Hazardous
Waste Disposal
Facility
FeNb Thermite Slag Nonhazardous Public Waste
Disposal Facility
-------
Generating Process Waste Characteristic Management
Option
3. Vanadium Manufacturing Thermite Slag Nonhazardous Public Waste
Disposal Facility
4. Round Products Forming Salt Bath Material EP Toxic (COOS) Hazardous
Waste Disposal
Facility
5. Extrusion Products Rocker woe Nonhazardous (animal fat) Biological
Forming Treatment
lJigoon
Honing Solids Fire Hazard Hazardous
Waste Disposal
Facility
Al20J Blasting Grit Nonhazardous Recycle or
Public Disposal
Facility
Scrubber Solids Nonhazardous Public Disposal
(Nonhazardous) Facility
Scrubber Solids (Hazardous) EP Toxic (0008) Hazardous
Waste Disposal
Facility
6. Powder Metallurgy Isopropyl Alcohol Ignitable ignitable Waste
Incinerator
1,1,1- Trichloroethane Toxic (Foo1) Reclaimed
7. Metal Forming Metal Grinding Solids Fire Hazard Hazardous
Waste Disposal
Facility
Abrasive Saw Fines Nonhazardous Public Disposal
Facility
Metal Fines Fire Hazard Onsite
Oxidation in
Burnback
System
Burnback Material Nonhazardous Public Disposal
Facility
8. Paint Shop and . Waste Thinners Ignitable Incineration
Maintenance Shop
9. Analytical lJiboratory Methyl Isobutyl Ketone Ignitable Recycle Onsite
1,1,1- T richlaroethane Toxic (FOO1) Reclaimed
-------
In the summer of 1988, in order to expedite cleanup, EPA and TWCA identified the
sludges in the LRSP and Schmidt Lake as a separate operable unit from the rest of
the Site for the following reasons:
a)
the sludges in the unlined ponds were a likely source of groundwater
contamination;
the LRSP and Schmidt Lake are located in the Willamette River flood
plain;
the sludges in the ponds contained low levels of radioactive materials,
and had been the focus of community concerns about the Site; and
TWCA, in response to the community concerns wished to clean up the
ponds without waiting for the full Site RI/FS to be completed.
b)
c)
d)
A Record of Decision (ROD) for an Interim Response Action at the Sludge Ponds Unit
was signed by EPA on December 28, 1989. The Operable Unit ROD presented the
selected remedial action for the sludge ponds unit.
The major components of the selected remedy consisted of:
- Excavation and removal of the sludges from the ponds.
- Partial solidification of the sludge with a
solidification agent such as Portland cement.
- Construction of a monocell at an off-site permitted solid
waste facility.
- Transportation of the solidified sludge to the off-site
facility and disposal in the monocell.
- Long-term operation and maintenance (O&M) of the off-
site monocell.
On February 14, 1991, EPA issued a Unilateral Order (Order) to TWCA for design and
implementation of the selected remedy for the operable unit. In June of 1991,
construction of the off-site monocell at the Finley Buttes Landfill in Boardman, Oregon
was completed. Excavation and removal of the sludges began in July of 1991 and
was completed in November 1991. Approximately 100,000 cubic yards of solids
(including cement) were transported to the monocell at Finley Buttes. Cover
construction and gr~s seeding of the monocell was completed in April 1992. On
June 30, 1993, EPA issued a Certification of Completion for the Sludge Ponds
Operable Unit Remedial Action to TWCA.
-------
3.4.2 Supplementary Removal Action at Schmidt Lake
After removal of the lime solid wastes from Schmidt Lake in 1991 as part of the
operable unit remedial action, additional follow up work included the removal of
materials containing metal crucibles and zircon sand with low levels of thorium and
uranium from beneath the earthen bench in the northwest comer of the sludge pond.
In December 1992. 2,016 cubic yards of material were excavated and transported to
the U.S. Ecology 10w~level radioactive waste site in Washington for disposal.
3.4.3 Soli Removal In Fabrication Area
In December 1991, during the installation of a soil boring adjacent to the Emergency
Services Building in the Fabrication Area of the main plant (Boring B91-5) (Figure 3-
3) I a floating nonaqueous oil layer containing 8 percent PCBs was detected.
Groundwater in the vicinity of this boring contains up to 22,500 parts per billion (ppb)
PCBs. Additional sampling identified an area of soil, approximately 30 feet by 30 feet,
as a probable source/receptor for the PCB-contaminated oil.
In order to prevent further degradation of water quality resulting from the oil layer, in
November 1992 TWCA initiated a removal action in the area. After approval by EPA,
TWCA excavated approximately 230 cubic yards of PCB-contaminated soil and
disposed the soil at an off-Site permitted landfill. However, the oil layer itself was not
addressed and the source of the oil layer was not identified.
3..4.4 Groundwater extraction In extraction Area (Well PW-28A)
Well PW-28A is located in the northerly portion of the Extraction Area of the main plant
(Figure 3-4). Important features in the vicinity of this well include the zirconium-
hafnium separations process building, located to the southwest of PW-28A, and feed
makeup (zirconium chloride dissolving process), located to the southeast. -
Groundwater at this well is characterized by a very low pH (approximately 1) and
elevated concentrations of inorganic and organic compounds (Table 3-2). The total
dissolved solids (TOS) concentration is approximately 41 to 42 grams per liter (g/I)
and includes elevated concentrations of radium, uranium, and thorium. The maximum
total radium activity was approximately 650 picocuries per liter (pCi/I). The chemistry
of the groundwater suggests that the source of the contamination is the residues of
feed makeup solution that was released as a result of tank failures prior to 1979.
In 1991, a pilot test apd treatability study was implemented by TWCA to determine the
feasibility of extracting and treating the contaminated groundwater from Well PW-28A.
Groundwater from the well was pumped to a 5,500 gallon storage tank located near
the well. The water was then transported to TWCA's existing barium coprecipitation
treatment facility near the Lower River Solids Pond. The metals in the water were
removed (precipitated) and the pH was adjusted by treating the water with barium
-------
I ~ PW'~ I
D~ ~gc( ~D PW_"A:/-~.
-+~~2A ~ /
PW~IA [}-I ~ nN /: ./
I ~. .
. -----.,/
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c
D
1
0 200
SCALf IN FEET
(Approximale)
LEGEND
. Boring
+ Monil~ring Well
~igurc 3-3
LOCATION OF BORING B91-5
TELEDYNE W AH CHANG
-------
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\ \, \ \ ~.,' \. ," .~.. "'''''''' , L - -
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-------
----w.._"i4D;i4~~n"'~:f~:~:
Treatability Study
Analyte Round 1 Round 2 Round 3 Background
(9/89) (4/90) (4-91) 10/14/91 10/21/91 12/03/92 1/14/92
VOlATILE ORGANIC COMPOUNDS (ppb)
2.Butanone '
. 17 36 18 42 11 9J 8J ND
Chloroform 8 7 9 8 7 7 4J 4.81
Chloromethane 36 21 45 20 14 15 5J ND
1,1-Dichloroethytene 7 4J 2J ND ND ND ND 4.09
Methytlsobutylketone (MiSt<) 120 200D 220 200 160 180 150 ND
1 1,1- Trlchloroelhane 60 46 29 17 9 11 2J ND
TOTAL METALS~)
Aluminum 1,720,000 1,930.000 1,430,000 1,358,000 772,000 721,OOOL 884,000J 44,299
-
-..J
Arsenic 586K 537 399 515 130J 53.4 131L 15.8
Barium 8.160 6,570 5,740 4,840 2,740 3,660L 3,170 243
Cadmium 12J 8.4 13.8L 12.3K 7.0K 8.4 8.1 0.44
Calcium 920,000 1,030,000 899,300 809,1ooL 454,OOOL 538,000 492,000 43,960
Chromium 10.800 10,500 7,900 6,240L 4,870L 6,390 7,000 48
Copper 3,880 4,610 3,700 3,000 1,640 2.520 2,340 60
Iron 2,450,000 2,170,oooK 1,226,000 1,OO8,oooL 73O,oooL 946,oooL 853,000 48,800
Lead 3,06OK 1,920 1,500 846L 449 504L 557 41.9
Magnesium 597,000 713,oooL 560,800 455,600 257,oooL 321,oooL 283,000 25,300
Manganese 25,700 23,400 21,100 30,600 18,400 14,400 18,500 4,450
thorium 1,930 1,490 1,110L 623L 472 632L 8,990 50.6
-------
."tt~;;
Treatability Study
Malyte Round 1 Round 2 Round 3 Background
(9/89) (4/90) (4-91) 10/14/91 10/21/91 12/03/92 1/14/92
Zinc 2.590 2,760 2,720 2.450 1,660L 2.570L 2.800L 193
Zirconium . NA NA NA 3,000.OOOL 2.24O,OOOL 2.275,6S1L 2.270.000L NA
GENEJW. CHEMISTRY (ppm)
Ammonia 1,200 1,100 930 920 540 610 480 2.358
Chloride 21.000 20,000 17.000 13.000 .,400 10,000 10,000 59.3
Sulfate 1,100 730 440 280 150 240 210 17.12
Total Dissolved Solids .1,000 42,000 29,500 15,400 1.,400 16,500 11,700 392
RADIONUCUDES. (pOll)
Radium.2.26 .20 220 82 170 78 80 80 1.47
....
co 130
Radlum-228 230 200 140 23 130 56 2.54
Notes:
a Value was reported a ammonium (NH4)
NA .. Not analyzed
ND .. Not detected
D Sample required dilution
J Estimated value below method detection limits (organic compounds)
K Biased high
-------
chloride and barium sulfate. The solids generated by the barium coprecipitation
process were sent to the Low Level Radioactive Disposal Area at Hanford in
Washington State.
Approximately 28,400 gallons of groundwater were removed and treated. The
extraction and treatment system was in operation for approximately 4 months, from
October 14, 1991 to February 12, 1992. Pumping rates from the well varied from 0.1
to 1.0 gallons per minute (gpm). During the pumping period the pH averaged
between 0.8 and 1.2. Groundwater samples were taken during the pumping period.
Sampling results were inconclusive. Concentrations of organic compounds generally
decreased during the pilot test. However, concentrations of some inorganic heavy
metals such as chromium, nickel, zinc, and thorium actually increased during the test.
3.5
Enforcement Activities
Since 1956 when Wah Chang took over the facility, TWCA has had a history of
variance with state and federal environmental agencies. Some of the major
enforcement actions pertaining to past actions undertaken pursuant .to CERCLA are
summarized below:
.
In March of 1975, the process wastewater treatment facility was issued a
NPDES permit by DEO.
.
The presence of low-grade radioactive materials in the sludge ponds at the
TWCA facility was first confirmed by the Oregon State Health Department in
1977.
.
In March 1978, a Naturally Occurring Radioactive Materials (NORM) license was
granted to TWCA to transfer, receive, possess and use zircon sands and
industrial byproducts containing licensable concentrations of radioactive
material. -
.
In 1981, TWCA applied to the state of Oregon's Energy Facility Siting Council
(EFSC) for a site certificate to close the LRSP and to store approximately
120,000 cubic yards of lime solids on Site.
.
The TWCA Site was proposed for inclusion on the National Priorities Ust (NPL)
in December 1982. In October 1983, The TWCA Site was placed on the NPL.
TWCA was found in violation of wastewater discharge permits in 1975, 197.7,
and 1978; subsequent process changes reduced the toxicity of the facility's
wastewater discharges. TWCA was assessed fines for other water quality
permit violations in 1979, 1980, and 1989. The facility was fined for illegal open
burning in 1983. In 1986, TWCA was cited for several violations of the state's
.
-------
hazardous management rules.
.
After several years of hearings, court actions, and sampling investigations, the
EFSC ruled in 1987 that the sludge ponds were not subject to their jurisdiction,
because the levels of radioactivity were too low. TWCA then submitted a
closure plan for the LRSP to the Oregon State Health Division, however EPA
and other agencies recommended that closure be delayed until after conclusion
of a remedial investigation.
.
On May 4, 1987, TWCA signed a Consent Order with EPA to conduct the
Remedial Investigation/Feasibility Study (RI/FS) pursuant to Section 106 of
CERCLA 42 U.S.C fi9606.
.
EPA Region 10 issued a Record of Decision (ROD) for an Interim Response
Action for the Sludge Ponds Operable Unit on December 26, 1989.
.
On February 14, 1991, EPA issued a Unilateral Order (Order) to TWCA pursuant
to Section 106 of CERCLA, 42 U.S.C. fi9606. This Order called for TWCA to
conduct the remedial design and remedial action as set forth In the operable
unit ROD.
.
Based on additional information received by EPA regarding the burial of
hazardous materials in or around Schmidt Lake, on February 13, 1992, EPA
sent to TWCA a Request for Information pursuant to Section 104 of CERCLA
42 U.S.C. fi9604 and Section 3007 of RCRA 42 U.S.C. fi6Q27.
.
In March and April of 1992, EPA's National Enforcement Investigation Center
(NEIC) conducted a multi-media compliance Investigation of the TWCA facility.
TWCA currently holds permits for water and air emissions. Discharge of process
wastewater is regulated by DEO through a NPDES permit. An Air Contaminant
Discharge Permit regulates air emissions at the TWCA Facility. The TWCA facility is
currently classified as a hazardous waste generator under the Resource ,Conservation
and Recovery Act (RCRA) program.
3.5.1 RI/FS Reports Produced by Potentially Responsible Party Under Consent
Order with EPA
.
June 1991, Ct:t2M Hill on Behalf of Teledyne Wah Chang Albany, .Remedial
Investigation/Feasibility Study for Sludge Ponds Operable Unit, Teledyne Wah
Chang Albany", Volumes I through III.
March 1993, CH2M Hill on Behalf of Teledyne Wah Chang Albany, .Remedial
Investigation/Feasibility Study. Teledyne Wah Chang Albany, Albany, Oregon",
.
-------
including Executive Summary (Volume I), RI Report (Volume II), Baseline Risk
Assessment for Human Health and Environment (Volume III), FS Report
(Volume IV), A Summary of the Analytical Data for Phase 1 and Phase 2 of the
RI (Volume V), and Appendices for the first four volumes (Volume VI).
.
December 1993, CH2M Hill on Behalf of Teledyne Wah Chang Albany,
8Addendum 1 - Radiological Survey, Remedial Investigation/Feasibility Study,
Teledyne Wah Chang Albany Facility, Millersburg, Oregon8, Addendum to the RI
Report, Risk Assessment, and FS Report Incorporating External Gamma and
Ambient Outdoor Radon Measurements.
3.5.2 Major Reports Produced by Teledyne Wah Chang Albany Under Unilateral
Order of EPA
.
August 1991, 8Remedial Action Disposal Plan for Operable Unit No.1, Teledyne
Wah Chang Albany, Volumes I and W.
May 1993, 8Remedial Action Report, Teledyne Wah Chang Albany, Ume Solids
Operable Unit No. 18.
.
3.5.3 Major Reports Prepared and Issued by EPA
.
December 1989, 8Record of Decision, Decision Summary and Responsiveness
Summary for Interim Response Action, Teledyne Wah Chang Albany Superfund
Site, Operable Unit #1 (Sludge Ponds Unit), Albany, Oregon8.
.
August 1992, National Enforcement Investigations Center, 8Multi-Media
Compliance Investigation, Teledyne Wah Chang - Albany, Millersburg, Oregon..
August 1993, 8Superfund Proposed Plan, Teledyne Wah Chang Albany,
MiUersburg, Oregon8. -
.
-------
4.0 COMMUNITY RELATIONS
The Revised Draft RI/FS and the Proposed Plan for the Site were released to the
public for comment on August 25, 1993. The Proposed Plan addressed remediation
for contamination in groundwater and sediments, and in surface and subsurface soils.
Based in part on supplemental RI/FS data received from Teledyne Wah Chang Albany
on December 21, 1993, EPA determined that it would be most realistic to address
remediation of the contamination in two parts. This ROD addresses contamination in
groundwater and sediments as Operable Unit Two. Remediation of contamination in
surface and subsurface soils will be addressed in a subesequent ROD for Operable
Unit Three. The public comment period initially lasted from August 27 to September
27, 1993. Because of the large number of public comments received, and at the
request of Teledyne Wah Chang Albany, the public comment period was extended
until October 27. 1993. The RI/FS and supporting documentation were made'
available to the public in both the administrative record and information repositories
maintained at the Superfund Records Center in Region 10's offices in Seattle, the
Oregon Department of Environmental auality in Portland, and the Albany Public
Ubrary. The notice of availability of the RI/FS documents was published in the
"Albany Herald- in August 1993.
A public meeting was held at Unn-Benton Community Col/ege in Albany, Oregon on
September 14, 1993. The meeting was attended by approximately 160 people
including representatives of TWCA. At this meeting, representatives from EPA
presented the results of the RI/FS and EPA's preferred remedial alternative. In
addition, EPA answered questions about the preferred alternative and about
contamination at the Site. Twenty-two commenters presented oral comments at the
meeting. Most of the commenters expressed recognition for the value that Teledyne
brought to the community as a local employer. However, rather than addressing the
cleanup activities in the Proposed Plan, the majority of the comments focused on the
potential economic effects that the preferred remedial alternative would have on
~~~ -
Commenters were concerned that the Proposed Plan would hinder TWCA's ability to
adapt competitively in the market place, and that regulatory efforts of the
environmental agencies. would impose an ever increasing financial burden on TWCA
with ever decreasing environmental benefits. Commenters also questioned whether
the health risks associated with human exposure to contaminated groundwater at the
Site were realistic as portrayed in the Proposed Plan because of the unlikely scenario
of the groundwater Qaing used for human consumption.
A transcript of the public meeting is available at the information repositories listed
above. A meeting on the record was hetd between representatives of EPA, DEa, and
TWCA on October 15,1993 at which time TWCA reiterated its comments on the
Proposed Plan. EPA's responses to comments received at the public meeting and
-------
during the public comment period are included in the Responsiveness Summary,
which is Appendix A to this ROD.
Past EPA Region 10 community relations activities at the Site have included the
following:
.
December 1982 - TWCA Site proposed for inclusion on NPL: 6o-day public
comment period initiated.
.
October 1983 - TWCA Site listed on NPL
.
February-May 1987 - Local citizens and officials interviewed in order to prepare
a Community Relations Plan.
.
November 1987 - Final Community Relations Plan issued.
.
November 1987 - Information Repositories established at Albany Public Ubrary,
DEO (Portland), and EPA Region 10 (Seattle).
.
November 1988 - RI/FS work plan for entire facility sent out for 3O-day public
comment period. Work plan was placed in Information Repositories and a Fact
Sheet was published.
.
February 1989 - Fact Sheet published announcing EPA's approval of the final
work plan.
.
June 1989 - Fact Sheet published announcing that TWCA had submitted a draft
RI/FS report to EPA for the Sludge Ponds Operable Unit.
.
August 16, 1989 - Interim Action (Operable Unit #1) Proposed Plan pul?lished.
August 18 - October 16, 1989 - Public comment period for the Operable Unit
#1 Proposed Plan.
.
.
September 6, 1989 - Public meeting for the Operable Unit #1 Proposed Plan
was held in Albany, Oregon. '
.
October 11, 1990 - Fact Sheet published announcing expansion of scope of RI
to include ider)tification of potential sources of contamination. Fact Sheet also
announces beginning of negotiations with TWCA for Sludge Ponds Operable
Unit remedial action.
.
March 5, 1991 - Fact Sheet published announcing issuance of Unilateral Order
by EPA to TWCA for dean up of Sludge Ponds Operable Unit.
-------
.
July 1991 - Local citizens and officials updated and interviewed in order to
prepare a Revised Community Relations Plan.
.
October 1991 - Revised Community Relations Plan issued.
.
February 19, 1992 - Fact Sheet published announcing issuance of Request for
Information letter by EPA to TWCA regarding the threat of a release of
hazardous substances in or around Schmidt Lake. Fact Sheet also updated
continuing RI investigations.
.
October 29, 1992 - Fact Sheet published announcing that TWCA had submitted
a draft RI/FS report to EPA for the entire Site. Fact Sheet also updates public
on discovery of decayed metal drums containing zircon sand within Schmidt
Lake.
.
April 1, 1993 - Fact Sheet published announcing removal of decayed metal
drums and approximately 2,100 cubic. yards of contaminated sands from
Schmidt Lake.
.
August 25, 1993 - Proposed Plan for entire Site Superfund cleanup published.
August 27-Qctober 27, 1993 - Public comment period for Proposed Plan.
.
.
September 14, 1993 - Public meeting to take comments and answer questions
regarding the Proposed Plan held in Albany, Oregon.
.
October 15, 1993 - EPA meets with TWCA to discuss TWCA's objections to
Proposed Plan. .
.
October 22, 1993 - Fact Sheet published updating public on public comment
period and Proposed Plan. -
-------
5.0 SCOPE AND ROLE OF RESPONSE ACTION WITHIN SITE STRATEGY
As with many Superfund sites, the problems at the TWCA Site are complex. TWCA is
an active facility with ongoing operations. As a result, EPA organized the Superfund
work into three operable units (OUs). These are:
.
OU One: The sludges in the LRSP and Schmidt Lake.
.
OU Two: Contamination in the groundwater and sediments.
.
OU Three: Contamination in surface and subsurface soils.
EPA has already selected a remedy for OU One in a ROD signed on December 28,
1989. The selected remedy for OU One has resulted in removal and off-Site disposal
of contaminated sludges from the LRSP and Schmidt Lake. This remedial action was
completed in June 1993.
Remediation of contaminated soil at the TWCA Site will be addressed in the
subsequent third operable unit ROD.
The second OU, the subject of this ROD, addresses the contamination in groundwater
and sediment at the Site. The remedial actions described in this ROD are designed to
deal with sources of groundwater and sediment contamination, as well as identified
contamination in groundwater and sediment at the facility which has been caused by
past practices.
Groundwater beneath the TWCA Site is contaminated with metals, volatile organic
compounds (VOCs) , PCBs, and radionuclides. Groundwater beneath some areas of
the Site is very acidic. Groundwater monitoring wells near the boundary of the Site are
contaminated with VOCs. Modifications of the general groundwater flow direction due
to interference from man-made structures on the facility may cause localized 6ff-Site
migration of contaminated groundwater.
Sediments in surface water bodies within and adjacent to the TWCA Site are
contaminated with PCBs and HCB.
The remedial actions presented in this ROD will address the presently known threats
to human health and the environment posed by contaminated groundwater, and
sediment at the TWGA Site.
-------
6.0 SITE CHARACTERISTICS
The TWCA RI was conducted in two phases. Phase I was designed to determine
whether contamination existed in groundwater along the perimeter of the facility.
Phase II was designed to locate and investigate potential sources of contamination at
the facility. In recognition of TWCA's concerns, EPA agreed that the scope of the
RI/FS could be designed so as not to interfere with ongoing operations at the facility.
Concerns regarding the potential adverse impact of the RI/FS on TWCA's ability to
remain in operation, were also a factor in EPA's agreement at the time of scoping of
the RI/FS that TWCA could forego sampling of areas beneath certain active ponds,
and existing buildings and structures at the facility, at that time. It was recognized
that, should there be contaminated areas beneath those unsampled areas, those
areas could potentially serve as additional contaminant sources that could continue to
undermine the effectiveness of the remedial action. Because of the potential for those
contaminant sources to adversely impact the effectiveness of the remedy,
determination of the nature and extent of possible contamination in these unsampled
areas must necessarily take place at some point in the Mure. EPA has determined
that this can best be done through integration of such sampling into the normal
ongoing operational activities at the TWCA facility as described in the section entitled
.Deed Restrictions and Institutional Controls. which is Section 10.3.1 of this ROD.
6.1
Geology and Soils
The geology beneath the TWCA Site is typified by a stratigraphic column common to
much of Oregon's central Willamette Valley. The column consists of five stratigraphic
units which in order of youngest to oldest are; recent alluvium, Willamette Silt, Unn
Gravel, Blue Clay (present in stratigraphic lows of the Spencer Formation), and
Spencer Formation. A geologic cross section showing these units beneath the Solids
Area is shown in Figure 6-1. Engineered fill is also present in many locations within
the main plant area. The stratigraphic column at the Farm Ponds Area consists of
Willamette Silt (brown silt and basal gray clay), Unn Gravel, and Blue Clay. -
6.2
Hydrogeology
6.2.1 Main Plant
Under the main plant, the Unn Gravel is the major water-bearing unit. The Unn Gravel
is laterally continuous beneath TWCA and is recognized as the aquifer for groundwater
supply in the Albany area. Groundwater beneath the main plant generally flows
westerly towards the 'Willamette River, but it is also greatly influenced by Truax and
Murder Creeks, and possibly by the man-made structures at the main plant.
-------
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Man-made features which can influence groundwater movement include Ponds 1 Band
2, and the Cooling Water Pond in the vicinity of well PW-28A (Figure 3-4). Off Site,
the primary settling ponds used by Willamette Industries can locally influence
groundwater flow.
The Spencer Formation, which underlies the Unn Gravel, has little water-bearing
capacity and is considered an aquitard beneath the Site. The Blue Clay is also
considered an aquitard where it is present. A schematic cross section of the area
across the main plant (Extraction Area) is shown in Figure 6-2.
6.2.2 Farm Ponds
The Unn Gravel constitutes the deep aquifer beneath the Farm Ponds Area. The
Willamette Silt overlying the Unn Gravel comprises the shallow saturated unit. Beneath
the ponds, groundwater flows in a westerly direction. Groundwater is mounded in the
Willamette Silt beneath and adjacent to the ponds due to the higher hydraulic head
caused by the liquid within the ponds. The Blue Clay underlying the Unn Gravel is
considered to be an aquitard. The Willamette Silt (gray clay), which overlies the Unn
Gravel and is beneath the water-bearing Willamette Silt, is also considered an aquitard.
A hydrogeologic cross section of the Farm Ponds Area is shown in Figure 6-3.
6.3
Extent of Contamination
For purposes of the RI, the lWCA Site was divided into five areas, termed .remedial
sectors". The remedial sectors, which are shown in Rgure 6-4, include; (1) the Farm
Ponds Area, (2) the Extraction Area, (3) the Fabrication Area, (4) the Solids Area, and
(5) the Surface Water Remedial Sector. Groundwater and sediment contamination, as
applicable, will be discussed below for each of these remedial sectors. In addition,
sources of groundwater or sediment contamination are identified, where applicable.
6.3.1 Farm Ponds Area
The Farm Ponds Area is located approximately 3/4 mile north of the main plant, and
contains four 2-1/2-acre solids storage ponds (Rgure 6-5). These ponds receive lime
solids waste generated in lWCA's industrial wastewater treatment plant. The ponds
are constructed with a soil-bentonite liner. The ponds have been operational since
1979, and are regulated under the National Pollutant Discharge Elimination System
(NPDES) program.
The lime solids are similar in composition to the sludges that were placed in the LRSP
and Schmidt Lake prior to 1979. However, the Farm Ponds solids have a lower
concentration of radionuclides.
-------
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-------
The soil amendment area is a 47.8-acre tract located directly north of the Farm Ponds
(Figure 6-5). In 1975 and 1976, TWCA obtained solid waste permits from DEO to use
solids from the primary wastewater treatment plant experimentally as a soil
amendment. These solids were applied once in 1976. The solids were similar in
composition to that of the LRSP and Schmidt Lake and probably contained low-level
metals, radionuclides, and organic compounds.
6.3.1.1
Groundwater Contamination at the Farm Ponds Remedial Sector
Shallow groundwater in the Willamette Silt and deeper groundwater in the Unn Gravel
downgradient of the Farm Ponds (southwest) contains VOCs including
tetrachloroethene (PCE), and vinyl chloride (Table 6-1). These contaminants may be
coming from pond water which contains less than 1 mg/I of total VOCs and is thought
to be leaking through the Farm Ponds clay liner.
Groundwater in the shallow saturated unit to the south, southwest, and west of the
Farm Ponds contains elevated concentrations of 1, 1-dichloroethylene,
tetrachloroethylene, vinyl chloride, radium, thorium, magnesium, and thallium (Table 6-
1). .
6.3.2 extraction Area
The Extraction Area comprises the southern portion of the main plant. Its location is
shown in Figure 6-4. The RI identified five potential contaminant source areas within
the Extraction Area: the Feed Makeup area, the chemical unloading area, the V2
Pond, the Spill Treatment Plant, and the southern Extraction Area. Potential sources
of contamination in the Extraction and Fabrication Areas of the main plant are shown
in Figure 6~6.
6.3.2.1
Groundwater Contamination at the Extraction Area
Groundwater around the Feed Makeup Building (Well PW-28A) is heavily acidic (pH =
1) and is heavily contaminated with metals, uranium, thorium, radionuclides, ammonia,
chloride, and sulfates (Table 3-2). TWCA process operations at the Feed Makeup
Building includes the dissolving of zirconium tetrachloride containing approximately 2
percent hafnium tetrachloride in water. The resulting feed solution is transferred to the
separations systems via underground pipes. The RI/FS has identified the probable
source of groundwater contamination in this area as being past tank failures and leaks
or spills from the fee(,1 solution tanks and underground transfer pipes.
As previously mentioned in Section 3.4.4, for a four month period in 1991-1992,
approximately 28,400 gallons of groundwater from well PW-28A were extracted and
treated. During this period there was very little change in the pH value of in-situ water.
-------
.Table6-1 ... '" .
FARM PONDS AREA GROUNOWATERANALYTICALRESULTSSUMMARY
# Detects/ # Maximum Round
Analytes Samples Conc. Bckgrd Maximum
Detected Detected
VOLATILE ORGANIC COMPOUNDS (ppb)
l,l-Dichloroethane 16/54 120 ND 3
1,1-DichloroethYlene 5/54 4J ND 2,3,4
1,2-Dichloroethane 7/54 6 ND 1,2
1,2-Dichloroethylene 11/54 52 ND 3
1,1,2,2-Tetrachlorethane 5/54 5 ND 2
Tetrachloroethylene 16/54 130 ND 1
1, 1, l-Trichloroethane 9/54 13 ND 1
1,1,2-Trichloroethane 11/54 41 ND 1
Trichloroethylene 13/54 66 ND 3
Vinyl Chloride 5/54 11 ND 2
METALS (ppb)
Aluminum 52/54 154,000 44,750 1
Barium 51/54 958 267 1
Cadmium 24/54 25.8 0.54 1
Calcium 54/54 1,020,000 43,512 4
Chromium (total) 27/54 240 77 3
Copper 45/54 110 97 -3
Iron 54/54 139,000L 41,800 3
Lead 24/54 41 15.64 3
Magnesium 54/54 479,000 20,298 4
Manganese 54/54 3,460 8,868 4
Nickel 32/54 152 22.45 3
Sodium 54/54 368,000 37,876 1
.
Thallium 3/54 5.5 ND 1
Thorium 'J2/54 30.4L 8 3
-
Zinc 15/54 6,270 332 2
-------
Table 6~1.
FARM PONDS AREA GROUNDWATER ANALVTICAL RESUL TSSUMMARY
# Detects/ # Maximum Round
Analytes Samples Cone. Bckgrd Maximum
Detected Detected
GENERAL CHEMISTRY (ppm)
Ammonia 3/54 2 0.87 1,2
Chloride 34/54 18,000 12.12 1
Fluoride 6/54 3 ND 4
Nitrate 13/54 160 13.7 1
Sulfate 25/54 1,200 40 1
TDS 54/54 35,000 362 3
TSS 22/54 1,400 549 4
RADIONUCLIDES (pCi/l)
Radium-226 25/54 2.2 1.96 1
Radium-228 33/54 3.4 NA 1
NA = Not Analyzed
ND = Not Detected
J c Estimated value below method detection limits
L = Biased Low
Round 1 was sampled during 9/89
Round 2 was sampled during 4/9C
Round 3 was sampled during 4/91
Round 4 was sampled during 9/91
-
-------
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-------
It is possible that little change was seen because the 28,400 gallons represents a
small amount of the estimated total volume of water in the perched groundwater zone
screened by well PW-28A. However, it is also possible that there may still be a
continuous source of contamination to this perched zone as a result of continuous
leaks from the underground pipes in this area of the facility.
Groundwater contaminants found in monitoring wells located in the Extraction Area,
exclusive of well PW-28A are shown in Table 6-2. Groundwater in the vicinity of the
Spill Treatment Plant is contaminated with elevated levels of methyl isobutylketone
(MIBK), and ammonium. The Spill Treatment Plant receives liquids and liquid
byproducts containing MIBK and ammonium generated in the separations process.
Groundwater in facility perimeter wells located in the southern portion of the Extraction
Area contains elevated concentrations of trichloroethene (TCE) , 1,1-dichloroethene
(1,1-DCE), vinyl chloride, and manganese. The RI/FS identified the probable source
of groundwater contamination in this area as being solvents which are used in a
maintenance support function for process operations that are located in this area such
as the Coke Ball Mill.
6.3.3 Fabrication Area
The Fabrication Area occupies approximately 50 acres on the northern portion of the
main plant (Figure 6-4). The area is bounded by Truax Creek to the south, Murder
Creek to the north, Burlington Railroad tracks to the west, and Willamette Industries
and Southern Pacific railroad tracks to the east.
Potential source areas within the Fabrication Area that were identified in the RI are
shown in Figure 6-6. These areas include; the acid sump area, the Arc Melting
Building, the ammonium sulfate storage area, Truax Fill, the area near the Emergency
Services Building (Boring 891-5), and the area near the Powder Metallurgy Building.
6.3.3.1
Groundwater Contamination at the Fabrication Area
Groundwater contaminants found in monitoring wells located in the Fabrication Area
are shown in Table 6-3. Groundwater in the vicinity of the acid sump area contains
elevated levels of TCE, 1,1-DCE, 1,1,1-trichloroethane (1,1,1-TCA), fluoride, and
"ammonium. The acid sump area contains manufacturing process facilities where
caustics, acids, and solvents are used for cleaning metals. Acid spills have occurred
in this area in the p~t. In July of 1990, 3,000 gallons of nitric acid and 100 pounds of
hydrofluoric acid leaked from underground pipes near the acid transfer tanks. Two
-------
. . .
. .Tabl~q6;;2 '.....'. .. . . .
EXTRACTION AREA GROUNDWATERANALYTICALRESUL TSSUMMARY .
# Detects/ # Maximum Round
Analytes Samples Conc. Bckgrd Maximum
Detected Detected
VOLATILE ORGANIC COMPOUNDS (ppb)
Acetone 6/37 230 ND 2
Benzene 7/37 62 ND 1
Carbon Disulfide 3/37 92J ND 1
Chloroform 12/37 52 4.81 2
l,l-Dichloroethane 19/37 140 4.92 4
l,l-Dichloroethvlene 10/37 110 4.09 4
1,2-Dichloroethvlene 12/37 36 2.48. 1
Methvlisobutvlketone 9/37 7,500 ND 1
Tetrachloroethvlene 10/37 19J ND 4
l,l,l-Trichloroethane 14/37 600 ND 4
Trichloroethylene 18/37 330 ND 2
METALS (ppb)
Aluminum 32/37 378,000 44,300 1
Arsenic 26/37 234 15.8 3
Barium 32/37 1,080 243 1
Cadmium 20/37 9.2 0.44 3
Calcium 34/37 420,100 43,960 -3
Chromium 26/37 373 48 1
Copper 29/37 289 60 1
Iron 34/37 472,000 48,700 1
Lead 22/37 62.8L 41.9 1
Maqnesium 34/37 280,000 25,300 2
Manqanese 34/37 20,900 4,450 1
Nickel 24/37 171 29.4 . 1
Potassium 5/9 20,220 NA 1
-
Sodium 33/37 500,000 32,100 3
Thorium 23/37 30 7.75 1
-------
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,EXTRACTIONAREAq GROUNI)W~TERAN4LYTICALJRESULTSSUMMARY
# Detects/ # Maximum Round
Analytes Samples Cone. Bekgrd Maximum
Detected Detected
Uranium 32/37 53.8 3.47 2
Zinc 12/37 638 193 1
GENERAL CHEMISTRY (ppa)
Ammonia 14/37 1,400 2.35 4
Chloride 29/37 650 59.3 1
Fluoride 20/37 12 2.2 3
Nitrate 25/37 420 31.2 1
Sulfate 28/37 2,300 17.12 1
TDS 33/37 3,400 392 1
TSS 16/18 2,900 406 3
RADIONUCLIDES (pCi/1)
Radium-226 22/37 4.5 1.47 1
Radium-228 22/37 6.0 2.54 1
NA = Not Analyzed
ND c Not Detected
J = Estimated value below method detection limits
L = Biased Low
Round 1 was sampled during 9/89
Round 2 was sampled during 4/90 -
Round 3 was sampled during 4/91
Round 4 was sampled during 9/91
-------
-
# Detects/ # Maximum Round
Analytes Samples Conc. Bckgrd Maximum
Detected Detected
VOLATILE ORGAHIC COMPOUBDS t I)Db\
Acetone 6/72 3 , 400 ND 2
Ben zene 5 I 7 2 60 ND 1
Chloroethane 19/72 4 2 OD ND 1
Chloro form 1 3/72 2 7J 4 . 8 1 4
1 , 1 -D ich loroethane 54/72 4 , 200 4 . 9 2 4
1 , 1 -D ichloroethylene 42 I 72 2 4 , 000 4 . 09 3
1 , 2 -D ich1oroethane 4 I 7 2 22 OJ ND 2
1 , 2 -D ichloroethYlene 19/72 83 2 . 48 2
Methyl isobutylketone (HI BK) 7/72 8 5 , OOOD ND 1
Tet rachloroethylene 2 2/72 1 50 ND 1
1 , 1 , I-Trich loroethane 5 5/72 4 5 , 000 ND 2
1 , 1 , 2 -Trich loroethane 4/72 5 ND 1
Trichloroethylene 3 7/72 9 10J 3 . 4 7 4
Vinyl Chlor ide 1 5 I 72 50 ND 4
Xylenes ( mixed ) 3 I 7 2 4 6 ND 2
METALS (ppb)
Al uminum 7 1/72 990 000 44 3 00 - 1
, '
Arsenic 5 3/72 107 . OL 1 5 . 8 1
Bar ium 7 1/72 3 , 3 10 24 3 1
Cadmium 2 3/72 3 1 . 6 O . 44 2
Ca 1 c iurn 7 2/72 42 6 , 000 4 3 , 9 60 2
Chromium ( total ) 4 3 I 72 6 14 48 1
Copper 70 I 72 3 , 920 60 2
. 2/7
I ron 7 2 630 , 000 4 8 , 800 1
Lead 5 1/72 180 4 1 . 9 3
-
Hagnes ium 7 2 I 72 2 3 5 , 500 2 5 , 300 3
ManQanese 7 2/72 34 , 000 4 , 4 5 0 1
N icke 1 5 2 I 72 2 , 62 0 2 9 . 4 2
Se len ium 1 1 I 7 2 5 3 2 . 9 2 1
-------
'11_-
Maximum Round
Analytes # Detects! Cone. Bckgrd Maximum
# Samples Detected Detected
Silver 20/72 40K 2.51 3
Sodium 72/72 140,000 32,100 1
Thallium 4/72 5.1 3.57 1
Thorium 66/72 183L 7.75 4
Tin 8/72 168B 50.6 4
Uranium 32/72 250 3.47 1
Zinc 61/72 1,230 193 1
GEHERAL CHEMISTRY (ppa) .
Ammonia 28/72 6,100 2.35 1
Chloride 56/72 14,000 59.3 1
Fluoride 34/72 110 2.2 2
Nitrate 46/72 1,600 31.2 2
Sulfate 48/72 1,300 17.12 1
TDS 72/72 19,000 392 1
TOC 13/72 24 3.6 3
TSS 31/72 3,500 406 3
RADIONUCLIDES (pCi/l)
48/72 -
Radium-226 8.4 1.47 1
Radium-228 45/72 31.0 2.54 1
NA ~ Not Analyzed
ND . Not Detected
J ~ Estimated value below method detection limits
L ~ Biased Low
Round 1 was sampled during 9/89
Round 2 was sampled during 4/90
Round 3 was sampled during 4/91
Round 4 was sampled during 9/91
-------
solvent drum storage areas were also previously located near the acid sump area.
Groundwater near the Arc Melting Building in the eastern portion of the Fabrication
Area contains elevated levels of 1,1-DCE. TCE was used as a solvent in this area until
1982 when it was replaced with 1,1,1- TCA. In 1989, TWCA replaced 1,1,1- TCA with a
solvent known as Citra-Safe.
Groundwater near the ammonium sulfate storage area contains high concentrations of
MIBK, radium, thorium, ammonium, chloride, and sulfate. In June 1978 a 400,000-
gallon tank which was located in this area and contained an unknown quantity of
ammonium sulfate solution failed and its contents were spilled.
Groundwater in the vicinity of the Powder Metallurgy Building area in the northeastern
corner of the Fabrication Area contains elevated concentrations of PCE, 1,1-DCE,
fluoride, manganese, and PCBs. As explained above in Section 3.4.3, a floating oil
layer containing up to 8 percent PCBs was identified in Borehole e91-5 located outside
the Emergency Services Building. The removal action conducted in 1992 was not able
to identify the source of the floating oil layer.
A monitoring well completed in the Truax Fill {see Section 6.3.3.2 below} contains
elevated concentrations of 1,1-dichloroethene, and ammonium.
6.3.3.2
Contamination In Truax Fill
The earthen fill material along Truax Creek's northern bank, known as Truax Fill
contains undocumented quantities of construction debris and other solid wastes that
were placed in the fill from 1958 until 1978. The fill area is approximately 1,000 feet
long by 50 feet wide. Elevated concentrations of radionuclides, metals, PAHs, and
PCBs have been detected in the fill (Table 6-4).
6.3.4 Solids Area
The Solids Area covers approximately 20 acres and is located west of the main plant
between the Burlington Northern Railroad and the Willamette River (Figure 6-4). The
area contains four separate potential source areas which are shown in Figure 6-7.
These potential source areas include the LRSP, Schmidt Lake, the Magnesium
Resource Recovery Pile, and the Chlorinator Residue Pile. The lRSP and Schmidt
Lake received solids from TWCA's existing wastewater treatment plant from 1967 to
1979. These solids were the subject of a previous operable unit remedial action which
is described further in Section 3.4.1 of this ROD.
-------
Table 6-4
DETECTED CONTAMINANTS IN TRUAX CREEK FILL
Minimum Maximum
Analytes Concentration Concentration
Detected Detected
PCBs ppb ppb
Aroclor -1248 6,800 6,800
Aroclor -1254 340 1,700
Aroclor -1260 250 250
Semi-volatile ppb ppb
organics
Bis(2- 1,100 8,300
ethylhexyl)
phthalate
Metals ppm ppm
Chromium 40 626
Copper 46 3,270
Zirconium 4,050 39,200
Radionuclides pCi/ g pCi/g
Radium 226 .54 5.00
Radium 228 .20 1.50 -
m= arts er million
pp p P
ppb = parts per billion
pCi/ g = picocuries per gram
-------
.'
\\'."-.:.
c-
c-
'\
I. '. ~ .
'.::; \~~.
':. \ '. \ .
i \' :
. ; \~ ......\.onOE" ~nii';::-:':.:'
'.."""" ~. .'. '''''' ..~. ~
, .
'f-:.'.
'. ". \
I ,,' :;: . :..<~~-- ~''(/I?O
. . '., /-.-::." ',~ .ell c"
,. /./. . ..~, . . "'-::'- ee"
; 'I.~;./ . ,. . " - -.~ :.-'~
,':"
" \c.
. .
. <\\'"
. .. ";"
"",. ",
'. .
.'
. ..
, . ':.
\
,
\.
\
,
".
SOLIDS AREA SOURCE LOCATIO~S
FIGURE 6-7
~.((;{)NI)
11\1(1"
'--'--'" .-..
- -.--.---.------.-
- ---- --- ---
~
II
~
SCALE IN rcc I
;--,-====1
o lOa 200
U:CE"'::>
S TRC A.. O::UNOAn'
.._tj;""
toPOCr:UPMICAL llN(
OIR I ROAO
'''..... ,.
+
["SIINC f[NC[
UONI rORINC Yo'£ll
@
rCR..CR SOuRCC ARCA
I
-------
6.3.4.1
Groundwater Contamination at the Solids Area
Groundwater beneath the Solids Area is contaminated with elevated concentrations of
TCE, 1, 1-DCE, MIBK, magnesium, manganese, and ammonium (Table 6-5). Leakage
through the four unlined ponds is the identified source of all the contaminants in the
groundwater except manganese. Most of this source material has been the subject of
prior remedial activities as described in Section 3 of this ROD. Manganese is not used
in lWCA's processes and therefore the source of this chemical is uncertain.
6.3.4.2
Additional Contaminant Sources In the Solids Area
In 1991, EPA received information provided by a former lWCA employee that
radioactive materials had been buried in Schmidt Lake in the 1970's. These
radioactive materials were buried in drums which were allegedly located below the
sludges that had been the subject of the operable unit remedial action. Based on this
information, EPA requested lWCA to conduct additional geophysical investigations in
this area. In 1992, pursuant to the additional work provision of the RifFS Consent
Order with EPA, lWCA conducted an electromagnetic survey in this area. The
electromagnetic survey identified potential additional source materials in and around
Schmidt Lake. These source materials included several corroded metal drums
containing sands with elevated amounts of thorium and uranium, and an underground
storage tank containing approximately 1,000 gallons 01 liquid petroleum product.
In December 1992, 2,016 cubic yards of materials containing zjrcon sands with
elevated levels 01 thorium and uranium were removed from Schmidt Lake and
transported by lWCA to an off-Site low-level radioactive disposal facility. Surface and
subsurface soil sampling to confirm that all source material was removed from the
LRSP and Schmidt Lake has yet to be conducted~
Soil sampling performed in the vicinity of the former Chlorinator Residue Pile, !ocated
north of Schmidt Lake, revealed the presence of barium sulfate and chloride salts.
Source materials from the Chlorinator Residue Pile were removed in 1978 and barium
sulfate was applied over the area to bind remaining radium that had been found in the
residual chlorinator solids. .
In 1988, approximately 44,000 cubic yards of magnesium chloride solids were
removed by lWCA from the Magnesium Resource Recovery Pile, located at the
northeast comer of the LRSP. lWCA then capped this area with asphalt and now
uses it for materials t;\andling.
6.3.5 Surface Water Remedial Sector
The Surface Water Remedial Sector includes the surface water and sediment in the
-------
.'_4
Analytes
# Detects/ II
Samples
VOLATILE ORGANIC COMPOUNDS (ppb)
Acetone
3/56
2/56
2-Butanone (MEK)
Chloroform
4/56
23/56
4/56
4/56
3/56
l,l-Dichloroethane
l,l-Dichloroethylene
1,2-Dichloroethylene
Methvlene Chloride
Methylisobutylketone (MIBK)
Tetrachloroethylene
3/56
5/56
7/56
2/56
6/56
1/56
1, 1, I-Trichloroethane
1,1,2-Trichloroethane
Trichloroethylene
Vinyl Chloride
SEMIVOLATILE ORGANIC COMPOUNDS
(ppb)
5/56
1/56
1/56
53/56
3/56
31/56
56/56
26/56
56/56
41/56
35/56
-
56/56
35/56
56/56
56/56
46
Bis(2-ethYlhexyl)phthalate
Di-n-butvlphthalate
Di-n-octyl-phthalate
TOTAL METALS (ppb)
Aluminum
Antimony
Arsenic
Barium
Cadmium
Calcium
Chromium (Total)
Copper
Iron
Lead
Maqnesium
Manganese
Maximum
Cone.
Detected
Bckgrd.
21
12
ND
ND
5
23
4.81
4.92
8
43
4.09
2.48
4J
7J
ND
ND
2J
22
ND
ND
ND
IJ
29
11
3.47
ND
130
2J
8.02
ND
10
ND
282,000 44,300
18.1B ND
21.8L 15.8
2,800 243 .
40.7 0.44
1,990,000 43,960
405 48
269 60
504,000 48,800
61. 6J 41.9
11,400,000 25,300
72,500 4,450
Round
Maximum
Detected
2
2
2
2
2
2
1
1
2
2
2
2
2
1
1
1
-
1
2
1
2
1
1
1
1
2
1
1
-------
11_-
# Detects / Max imum Round
Ana lytes # samples Conc . Bckgrd Max imum
Detected Detected
Nickel 4 7/5 6 6 60 2 9 . 4 1
Se lenium 7/5 6 9 . 5K 2 . 9 2 2
Sod ium 5 6/5 6 l , 1 60 , 000 3 2 , 100 1
Tha 1 1 ium 6 / 5 6 5 . 5L 3 . 5 7 2
Thorium 3 7 / 5 6 4 5 . 7 7 . 7 5 1
Tin 10/5 6 2 , 980 50 . 6 3
Uranium 4 1/56 1 6 . 2 3 . 47 1
Z inc 2 4/56 670L 193 3
GENERAL CHEN I STRY (ppa)
Ammonia 47/56 580 2 . 3 5 2
Chloride 5 3 / 56 2 1 , 000 5 9 . 3 1
Fluoride 2 4 / 56 10 2 . 2 1
Nitrate 2 2 / 5 6 480 3 1 . 2 1
Sul fate 4 5/5 6 7 30 17 . 12 1
TDS 5 6/56 45 , 900 39 . 2 1
TOC 1 8 / 5 6 57 3 . 6 3
TSS 1 8 / 5 6 9 , 600 406 3
RADIONUCLIDES ( pCi/ 1 )
Radium-2 2 6 40 / 5 6 8 . 5 1 . 47 1
-
Radium-2 2 8 4 1 / 5 6 4 . 2 2 . 54 1
NA ... Not Analyzed
ND ... Not Detected
J ... Est imated value below method detect ion 1 imits
L = B iased Low -
Round 1 was sampled dur ing 9 / 89
Round 2 was sampled during 4 / 90
Round 3 was sampled dur ing 4 / 9 1
Round 4 was s ampled during 9 / 9 1
.
-,.
-------
Maximum Round
Analytes # Detects/ Cone. Bckgrd. Maximum
# Samples Detected Detected
VOLATILE ORGANIC COMPOUNDS (ppb)
Acetone 11/45 190 5 2
l,l-Dichloroethane 14/45 6J ND 1
l,l-Dichloroethylene 7/45 3J 1. 52 3
3J ND 3
990 3.04 1
1,1,2,2-Tetrachloroethane 2/45 lJ ND 2,3
Toluene 7/45 29 ND 2
l,l,l-Trichloroethane 17/45 6 1.82 1
Trichloroethene 14/45 5J 2.49 1
SEMIVOLATILE ORGANIC COMPOUNDS (ppb)
Bis(2-ethylhexyl)phthalate 2/45 6J ND 2
Dieth 1 hthalate 3 45 6J ND 2
TOTAL METALS ( b)
Aluminum 43/45 35,200 5,285 1
Arsenic 8/45 15.3 4.23 1
Barium 45 45 479 102 2
Cadmium 2/45 0.60L ND 3
Calcium 49/45 1,320,000 45,877 - 1
Chromium (Total) 17/45 84 59 2
Co er 34 3.93 1
Lead 45 3.38 1
Ma nesium 84,800 18,566 1
Nickel 32/45 55.2 17.4 2
Potassium 49/45 14,800 2,450 1
Selenium 9/45 8.60 7.46 1
Silver 2/45 1.40L ND 1
-
Sodium 49/45 301,000K 33,795 1
Thorium 11 45 3.40 0.1 1
Uranium 28 45 19.4 0.22 1
Zinc 20/45 22 153 2
-------
farm drainages, Truax Creek, Murder Creek, Second Lake, Third Lake, Fourth Lake,
and Conser Slough (Figure 6-4). The Willamette River borders the TWCA facility to
the west and is a receptor for both surface water and groundwater discharging from
the facility. However, the TWCA RifFS did not attempt to determine impacts of
contamination related to the TWCA facility on the Willamette River.
6.3.5.1
Surface Water Contamination
Elevated concentrations of total recoverable metals was found in the surface water of
the farm drainages (Table 6-6). These metals include aluminum, chromium, copper,
lead, selenium, silver, and zinc.
Truax Creek flows through the center of the main plant and separates the Fabrication
and Extraction Areas while receMng groundwater discharge and surface runoff from
both areas. A major inflow of fluids in Truax Creek is the NPDES-permitted discharge
from Pond 2. During the RI, elevated concentrations of ammonia and chloride were
found downstream of the TWCA NPDES outfall. These elevated concentrations are
. .
from samples which were taken within TWCA's currently defined mixing zone. One
sample from Second Lake had an elevated concentration of ammonia.
6.3.5.3
Sediment Contamination at the Surface Water Remedial Sector
PCBs were detected in sediments throughout the Surface Water Remedial Sector
(Figure 6-8). Sediments downstream of the NPDES outfall in Truax Creek had the
highest concentrations of PCBs found in sediments on the TWCA facility.
6.4
Transport and Fate 01 Contaminants
As a result of TWCA's ongoing and complex chemical processes there are many
identified potential sources of contamination at the facility (Table 6-7). In addition, the
facility has been operating for over 35 years and during that period numerous -
documented spills, and leaks of chemicals into the environment have occurred. The
environmental fate and transport of these chemicals depends on the physical and
chemical properties of the chemicals, along with the natural characteristics of the soils
and groundwater beneath the facility.
Groundwater generally flows in the direction of the Willamette River. No attempt was
made to determine impacts of groundwater contaminant transport from the TWCA Site
to the river, because. quantification of off-Site groundwater contamination was not
within the scope of the RifFS.
The RifFS determined that contaminated-groundwater flows into adjacent surface
-------
I.__~
Maximum Round
Analytes # Detects/ Cone. Bckgrd. Maximum
# Samples Detected Detected
GENERAL CHEMISTRY (ppaa)
Ammonia 18/45 11 ND 1
Chloride 35/45 2,700 69.6 1
Conductivity (umhos/cm) 44/45 8,200 502 1
Fluoride 7/45 2 NO 2
Nitrate 23/45 310 10.2 1
Sulfate 32/45 270 26.3 1
TDS 44/45 4,900 39.0 1
TSS 10/45 140 19.9 1
RADIONUCLIDES (pCi/l)
Radium-226 31/45 1.50 0.29 1
Radium-228 38/45 2.70 1.84 1,2
NA = Not Analyzed
NO - Not Detected
J - Estimated value below method detection limits
L - Biased Low
Round 1 was
Round 2 was
Round 3 was
Round 4 was
sampled
sampled
sampled
sampled
during
during
during
during
9/89
4/90
4/91
9/91
-
-------
".,
.-..~....
'-.
"'C.2 '00
....,"'t'.. 8o'
ooc-, . .,..,
...., ""C.h.»o 0.-
WC-1.2
,.,.fIIt8..., 0.-
"C..... .~ .,.. ./''' ~
'''.'''C8.1180 0- 0'
f ~.. .,.. .,.., .,.., l-
,.... ~.. ...0 ,.t.
.
\
,\...,
'. .
,
I
, .
" '.'
.\., \ .,t.
: :...~.. .,
OOl\
'/1'
.,
f 1\., '/11
'.~. "(.3. -0
-<.') . 00 .,.. .....
I.,.. "C". ., 0 ~13
ooc.. .,.. .
I.,. II>Q. 0 'I' .., ..,
1<., . .,.. .
....~. ".000 ...- 11.»0
tC-.I . .. . .
'-"Ca..~ ..'0 .,
't.. 'I" .,.. . .
..:. '"C.,. 0110 ...... .,
rc.1.' . .. .,..
I.,. .C~. ., .-
.,..
0..::.
,
'r><
.,.~ .~. :
~ 0'"
" '
LEGENO
.,..
0''''
. .
0'
....- STII{..... BOUNOARY
.,,\ TOPOCR_CAl lINC
OIRT ROAD ,
I
.
..
.,..
..
+
£XlsnN(; f[Na:
SAUPuNC lOCATION
!
"
~
Ca.... .,.,. ..,.. ::" I
~"PCa. 110 .,-0 ,
SAMPl[ LOCATION. SAMPL£
0411:5. -AI. 'TT[ AH()
CONCENTRATIONS IN..-
NOTES.
"0 - "OT O[TCC'[O AT "Cn.oo
O[JCCllo.. lI""S
SCAlC ... r[( J
L I
o 5CIo 1000
NS - Nor S"wp\'CO
TOTAL
Figure 6-8
PCBs IN SEDIMENT
-------
Remedial Sector
Farm POnds Area
V1
N
Extraction Area
..
;:.: .;..
Potential Source
Area
Farm Ponds'
So i I Amenanen t
Area
Southern
Extract ion Area
Feed Makeup Area
6--.
..
. "'... '. " .
. "'... '.
... .. "'
..... ...I:!;nfif fe~~toy~~,~h!t~W~~'~ViriJi11i' ....
..
: .....;:;..:...
..;.;::..:.;.
IJastes Received
or Rtleased
lime solids from
the central
wastewater
treatment system
are stored in
four ponds.
Area where lime
sol ids were
appl ied in a
single event
Solids contained
low levels of
radionuclides and
organic
chemicals; high
levels of some
metals.
Chlorinated
organic solvents
used in
maintenance
functions.
Pre.1078 feed
makeup.
Date of Use
and/or Release
1979 Present
1976
1956 to I ate
1970s or early
1980s
Original release
occurred before
1978; rei ease to
groundwater is
continuing.
Previous Remedial
Actions
A characterization
of the chemical
and physical
nature of the
solids was
conducted In 1988
(OU RIIFS Report,
CH2M HILL 1989)
None
None
pIJ'28A
treatabi Ii ty
study.
Volume or Area 0'
Concern;
Monitoring IJells
of Concern
Four 2'1/2 acre
POnds: IJel!s PII'
'OS, PIJ"OA, liS,
SS, and NS.
application rate
0' 108 tons (dry
weight) per acre
on H.8 acres
\Jells PIJ'25A, PIJ.
26A, PIJ"7A, and
PIJ"9A
IJell PIJ'28A
~
..
. :::.~:::
""'n.
n.. "..
.....
.....
.....
....,
..
"""
-..,
Notes
Solids pass TClP
and are not a
listed or
character! st i c
hazardous waste.
Solids passed
TClP and were
not a I fsted or
characteristic
hazardous waste.
..
. .:);
...;.;.:'.:.::
"n,
...
...
...
-....
.....-
..
--'n.. ..
...
.....,
Chemicals 0'
Concern
Vinyl chloride,
TCE, PCE,
magnesium.
PCBs, thor i um,
and radium
DeE TeE, and
vinyl chloride
Metals,
-------
. '.. .
.. . . . ...
n ... ..
..... Table 6~7 (Cbhfit1ued). ....
ification of P6tentLil Source
.TeledYne..W~hqhan9A1bany
Volume or Area of
Concern;
Potential Source lIastes Received Date of Use Previous Remedial Monitoring lIells
Remedial Sector Area or Released and/or Release Act ions of Concern
Extraction Area V2 Solids Pond Storage pond for 1960-1979 Solids removed to Residual chemicals
(Continued) sol ids from V2 Farm Ponds Area in subsurface
process. for drying in soi I.
1989. The pond
was then
dewatered, the
walls and bottom
of the pond were
hydraul ical I y
scoured, and the
pond is currently
being backfilled
with clean
material.
Spi II Treatment Receives liquids 1978-1980 Pi lot None PII-2ZA
Plant and liquid Plant
byproducts 19BO'Present;
generated in the full operation
\J1 separations
\.oJ
process. MIBK
detected in soil
and groundwater
near the plant.
Fabrication Area Acid SUI1p Area Process area 1959-Present Soil was excavated lIells PW-10, PII-
where caus tics in the vicinity of 11, PW-12, and PW-
and acids are a 1990 acid spill, 13.
used for cleaning the underground
metals. Two drun piping was
storage areas repl aced with
were near the open, epoxy-coated
acid slnlp. concrete trenches,
location of past and the area
documented paved.
releases.
Arc-Melting Area TCE was used in 1959-1989 None lie I I 0IJ-"2A
the area unt i I
1982, when it was
replaced with
1. 1.I-TCA. In
1989, 1,I,I-TCA
was replaced wIth
Citra-Safe, a
nonhazardous
sol vent.
Notes
Residual
chemicals in
soi Is were
investigated
through TClP and
01 leach tests
on 0- to 5-foot
depth soi Is.
Resul ts showed
that residual
chemicals in
soils were not
classified as
RCRA waste.
Chemicals of
Concern
Thorill11, radill11
MIBK, anrnonium
TCE, TCA, DCE,
DCA, vinyl
chloride,
nitrate.
DCE, vinyl
-------
Volume or Area of
Concern;
Potential Source \Jas tes Rece I ved Date of Use Previous Remedial Monitoring \Jells Chemi ca l s of
Remedial Sector Area or Released and/or Release Actions of Concern Notes Concern
Fabrication Area Ammonium Su1fate 1,00,000- ga II on June 1978 Residual ammonia \Jell P\J-OIA HI81(, ammonium
(Continued) Storage Area' plasteel tank levels in Truax
containing Creek are
ammonium sulfate monitored monthly.
and HI81( failed
southeast of \Jell
PIJ'DIA'.
Truax Fill Area Primari Iy earthen IJastes were None 1,000 linea I feet TCE, DCE, vinyl
fill, placed 1958.1976; a(ong north bank ch lor ide, PCBs
undocumented releases may be of Truax Creek; ammonium
quantities of continuing at \Jell PIJ.03A.
construction present.
debris and other
V1 solid wastes were
~
placed along the
northern bank of
Truax Creek. low
levels of PCBs
detected in
several f ill bank
sampl~s.
Powder Metallurgy Solvents used in 1959 to Present None \Jells pIJ." , pIJ'5, OCE, vinyl
Building Area II maintenance P\J.30A, P\J.I,5A, chloride IInd
funct Ion. and PIJ.I,6A. PCBs
Emergency Float ing mineral Detected in 1991; Removal action Soi I Boring B91-5. PCBs
Services Building oi I wi th PCBs date of release initiated in 1992
Area found on water unknown. to excavate
table. affected soil and
-------
Remedial Sector
Sol ids Area
V1
V1
Potential Source
Area
lower River'
Solids Pond
(lRSP)
Schmidt lake
Magnesiun
Resource Recovery
Pile
Chlorinator
Residue Pile
'" . .. .n.
. ... . . '":",' . .':-'",..;:: ::::.<::...~:. '::<.:::::::;:;.::<.;;":.::;:
Iq.el\~';f~{{~~eo6f~:i~~W:1if~\\4;~!:;8f.~~~)
lIastes Received
or Released
lime solids from
wastewater
treatment plant.
lime solids from
wastewater
treatment plant.
Magnesium
chloride solids
were formerly
stored in this
area.
Residue from sand
chlorinat i on
process.
Date of Use
and/or Release
Previous Remedial
Actions
1967-1979
Solids removed in
November 1991
(OURA)
1971,-1979
Solids removed In
November 1991
(OURA). Area Is
currently being
excavated to
Investigate burled
wastes.
May 1983
Pile removed in
1988. Area is
capped with
asphalt and Is
used for materials
handling.
Conf i rmat ion
samples were taken
from soils under
pi Ie after the
sol ids were
removed.
1972-1977
Removed and
disposed of at
Hanford in 1978.
Barium sulfate was
applied over the
area to bind any
remaining radium.
I = Ammonium sulfate is no longer stored at this location.
. = Ammonium sulfate tank has been removed; quantity In tank at time of failure Is unknown.
Volume or Area of
Concern;
Monitoring lIells
of Concern
85,000 cubic yards
of lime solids.
15,000 cubic yards
of lime solids.
1,1,,000 cubic yards
of solids.
5.000 cubic yards
of sol ids.
. ...
. .
Notes
Solids Area Is
to be further
addressed during
remedial design
stage of overall
roject.
Solids Area Is
to be further
addressed during
remedial design
stage of overall
project.
Solids Area to
be further
addressed during
remedial design
stage of overall
project.
Solids Area Is
to be further
addressed during
remedial design
stage of overall
project.
Chemicals of
Concern
Magnesiun,
manganese.
ammonia.
Magnesium,
manganese.
ammonia.
Magnesium
-------
water bodies, including the Willamette River. The RifFS did not quantify those
contaminants, because no direct impacts on the surface water bodies was observed.
During the RI, conductivity measurements were taken in surface water adjacent to the
TWCA facility. Conductivity measurements were generally high which indicates that
metal contaminants which leave the TWCA facility are potentially settling to the bottom
of these surface water bodies.
The following discussion highlights the typical environmental behavior of the chemicals
that were detected in groundwater, surface water, sediment, and soils at TWCA during
the RI. The chemicals are grouped according to the similarities of their physical and
chemical properties.
6.4.1 Organic Compounds
6.4.1.1
YOlatlle Organic Compounds (VOCs)
VOCs (e.g. TCA, TCE, DCE, vinyl chloride, MIBt<) were detected in groundwater
throughout the TWCA facility. VOCs are generally very soluble and mobile in
groundwater. Under certain anaerobic conditions. trichlorinated ethanes and ethenes
such as TCA and TCE may break down to dichlorinated and monochlorinated
compounds such as DCE and vinyl chloride. Anaerobic degradation processes are
generally very slow.
6.4.1.2
Semlvolatile Organic Compounds (SYOCs)
SVOCs detected at TWCA include HCB. HCB was detected in sediment in the
Surface Water Remedial Sector. Once HCB is released into the sediment it tends to
remain for extended periods of time due to its strong adsorption characteristics.
6.4.1.3
Polychlorinated Biphenyls (PCBs)
PCBs were detected in sediment throughout the TWCA facility. PCBs were also
detected in groundwater at one location in the Fabrication Area. PCBs are persistent
compounds in the environment, exhibiting a high affinity for particulate adsorption and
a resistance to biodegradation. Sorption to organic matter and bioaccumulation in
living tissues are expected to be the dominant environmental fate processes. PCBs in
groundwater are primarily sorbed to colloidal soil particles. Migration rates of PCBs in
sediment will depend. on sediment transport conditions.
6.4.2 Metals
Metals have been found in groundwater in some areas of the TWCA Site (e.g. Feed
Makeup Area/Well PW-28A) where the pH of the groundwater is so acidic (low) that
-------
the chelation ability of the metal is inhibited and the metal then leaches from the
subsurface soil into the low pH water.
6.4.3 Radlonuclides
Radium-226 and radium-228 are the primary radionuclides found in groundwater I and
sediment throughout the TWCA Site. These radionuclides are generally persistent in
the environment and have limited mobility in the soil/water system. They will decay
over time to the stable element lead, however, the half-life of radium-226 is 1,600
years, and the half-life of radium-228 is 5.7 years.
6.5
Potential Health Impacts 01 Major Contaminants Found at
the TWCA Site
Following is a description of the potential health effects of major contaminants which
have been detected in environmental media at the TWCA Site:
PCE was detected in groundwater at the TWCA Site. PCE has been classified as a
probable human carcinogen. PCE can cause liver toxicity. Inhalation of high
concentrations of PCE can depress the central nervous system (CNS) of humans and
may cause dizziness, headache, sleepiness, and incoordination.
1,1,1- TCA has been found in groundwater at the TWCA Site. High concentrations of
1,1,1- TCA are a CNS depressant and may impair psycho-physiological functions.
1,1,1- TCA can cause liver damage. Acute high-level exposures can adversely affect
the cardiovascular system. It is irritating to the skin and liquid can be absorbed
through the skin. In the past 1,1,1- TCA has been used as a solvent for various
processes at the TWCA facility.
TCE has been found in groundwater at the Site. When inhaled, high concentrations of
TCE may cause headache, vertigo, and visual distortion. Studies have shown TCE to
be carcinogenic in animals. EPA has previously classified TCE as a possible human
carcinogen. EPA is in the process of reevaluating whether TCE should be considered
a possible or a probable human carcinogen. TCE has been used in the past as a
solvent at the TWCA facility.
1,1-DCE was detect~d in groundwater at the Site. Inhalation by humans of large
concentrations of 1, 1-DCE can cause drowsiness, fatigue, and vertigo. Uver damage
may occur at relatively low doses. 1, 1-DCE is considered a probable human
carcinogen.
Vinyl chloride was detected in groundwater at the Site. Vinyl chloride is a known
-------
cancer causing agent in humans. Chronic inhalation of vinyl chloride can result in
Renauds syndrome, dermatitis, hepatitis-like changes, thyroid insufficiency, and acro-
asteolyisis as well as cancer. EPA currently has no evidence of vinyl chloride being
used at the TWCA facility. A possible reason for the presence of vinyl chloride in
groundwater at the Site is that anaerobic biodegradation of TCE to DCE and then to
vinyl chloride may be occurring beneath the Site.
MIBK has been detected in groundwater at the Site. High concentrations of MIBK are
a CNS depressant and can produce weakness, headache, nausea, light-headedness,
vomiting, dizziness, incoordination, and narcosis. MIBK may cause kidney and liver
damage.
HCB has been detected in sediments at the Site. HCB is classified as a possible
human carcinogen. Exposure to HCB may also cause liver damage.
PCBs have been detected in elevated concentrations in sediment and groundwater at
the TWCA Site. PCBs are dassified as probable human carcinogens. Non-
carcinogenic adverse health effects are dose-related and high concentrations may
include chloracne, skin rashes, burning of the eyes and skin, and liver damage. Low
concentrations may cause adverse reproductive and fetal effects, and nervous system
toxicity .
Magnesium has been detected in elevated concentrations in sediments, surface
water, and groundwater throughout the Site. Exposure to elevated concentrations of
magnesium can cause nausea, vomiting, and neuromuscular impairment.
Uranium has been found in elevated concentrations in groundwater at the TWCA Site.
Radioriuclides of uranium that emit alpha particles can cause bone cancers in humans.
Exposure of the skin to, and ingestion of, uranium compounds can cause kidney
damage. Radium has been found in groundwater at the Site. Ionizing .radiation (alpha
particles) from radium can cause bone cancer in humans. -
Nitrate has been found in groundwater at the TWCA Site. In the body, nitrate is
converted to nitrite. Methemoglobinemia is caused by high levels of nitrite, or
indirectly from nitrate. This results in a deficiency of oxygen transport in the blood.
Fluoride has been found in groundwater at the TWCA Site. Intake of excessive
fluoride over a long period of time causes damage to bones and teeth (fluorosis). The
most sensitive effect .0' fluorosis, tooth mottling, may occur at low concentrations.
Ammonia has been found in high concentrations in groundwater at the TWCA Site.
Ammonia is a strong alkaline and can cause damage to skin and mucous membranes.
An unpleasant taste is a sensitive indicator of ammonia concentrations.
-------
7.0 SUMMARY OF SITE RISKS
CERCLA response actions at the TWCA Site as described in this ROD are intended to
protect human health and the environment from risks related to current and potential
exposure to hazardous substances at the Site.
To assess the risk posed by Site contamination, a Baseline Risk Assessment was
completed by CH2M Hill on behalf of Teledyne Wah Chang Albany, as part of the
TWCA RI/FS. The Baseline Risk Assessment evaluated human health risks from
exposure to chemically contaminated groundwater. In addition, the RI/FS included a
Baseline Environmental Evaluation which evaluated potential effects of sediment and
surface water contamination on plants or animals on the Site.
EPA will document all risks due to exposure to contaminated soil at the TWCA Site in
a separate operable unit ROD.
7.1
Human Health Risks
7.1.1 Approach to Human Health Risk Assessment
TWCA is an active operating facility and is expected to remain so in the foreseeable
future. The percent of time that workers at an operating facility would spend in a
potentially contaminated area is generally less than if the Site were used for residential
purposes. Therefore, for purposes of characterizing human health risks on the plant
site, the RI/FS used an approach that is less conservative than if the TWCA property
were used for residential purposes. This less conservative approach assumed that
only workers would be exposed to risks from contaminants at the plant site.
Residential exposure may be higher than worker exposure because such exposure is
likely to be for 8 hours per work day rather than as much as much as 24 hours per
day. -
EPA also agreed with TWCA that, for purposes of the RIIFS, it would not be
necessary to interfere with TWCA's ongoing operations to the extent of digging
beneath areas underneath existing buildings and structures at the facility in order to
characterize the contamination in those areas at that time. Instead, contamination
beneath those areas is projected to be characterized on an ongoing basis during the
RD IRA stage each time TWCA discontinues use of, paves, or otherwise disturbs any
previously uncharact~rized pond, area, or building on the Site. .
In an attempt to realistically estimate potential human health risks at the TWCA Site
based on information presented in the RI, risks were calculated on a sample-specific
basis. Mere summation of risks at this Site would not have presented a meaningful
approach because of the varied contaminant source areas caused by the large and
-------
complex chemical and manufacturing processes at the TWCA facility. In these
circumstances, the sample-specific approach allows more accurate delineation of risks
from specific contaminant source areas. This approach also enables retention of
information on the geographic distribution of risk throughout the study area. The
sample-specific approach to calculating risk has also provided information on the
spatial discreteness and concentration of risk which was readily visualized by mapping
risks. The sample-specific risks were used to distinguish at the TWCA facility areas
that potentially exceed target risk levels from areas where exposure to contaminants
results in calculated risk levels below EPA's acceptable risk range.
For contaminants at the TWCA Site, the calculation of risk involved a 4-step process
which included the identification of contaminants of concern, an assessment of
contaminant toxicity, an exposure assessment of the population at risk, and a
characterization of the magnitude of risk.
7.1.2 Contaminants of Concern
A total of 93 chemicals were detected in environmental media at the TWCA Site. Of
these, 47 chemicals were identified as chemicals of potential concem in groundwater
at the Site. The chemicals of potential concern were selected based on; (1) the
chemical exceeded naturally occurring levels, (2) the EPA-derived toxicity value
available for the chemical, and (3) the maximum detected concentration exceeded a
conservative health-based screening concentration. Chemicals in groundwater were
eliminated from consideration if the maximum detected concentration was less than or
equal to 10-6 excess lifetime cancer risk value, or less than or equal to 0.1 hazard
quotient for noncancer effects.
A list of chemicals of potential concern, excluding those detected only in monitoring
well PW-28A, is shown in Table 7-1. (Refer to Table 3-2 for a list of chemicals
detected in monitoring well PW-28A.)
7.1.3 Toxicity Assessment
The Baseline Human Health Evaluation provides toxicity information for the chemicals
of concern. Generally, cancer risks are calculated using toxicity factors known as
slope factors (SFs), while noncancer risks rely on reference doses (RfDs).
EPA has developed SFs for estimating excess lifetime cancer risks associated with
exposure to potential, carcinogens. SFs are expressed in units of (mg/kg-dayr1 and
are multiplied by the estimated intake of a potential carcinogen, in mg/kg-day, to
-------
1-
Chemical
Farm Ponds
Plant SiteCa)
VOLATILE ORGANIC COMPOUNDS
Acetone
b
Benzene
c
c
Chloroform
c
c
l,l-Dichloroethane
b
b
1,2-D ichloroethane
l,l-Dichloroethene
c
c
c
c
1,2-D ichloroethene
b
Methylisobutylketone
1,I,2,2-Tetrachloroethane
ND
b
c
ND
Tetrachloroethylene
l,l,l-Tr ichloroethane
c
c
b
J ,J ,2~Tr ichloroethane
..
c
c c
c c
Trichloroethylene
Vinyl Chloride
SBMIVOLATILB ORGANIC COMPOUNDS
B is(2-ethy lhexy l)phtha 1 ate
c
-
NA c
PCBs
Total Aroc lors
-------
-
Chemica 1 Farm Ponds P 1 ant S ite( a)
METALS
Ant imony b b
Ar s e n ic c
Sa r ium b b
Cadm ium b b
Copper b
Magnes ium b b
Manganese b
Mercury ND b
N i c ke 1 b b
Tha 1 1 ium b b
Thor ium c
Uran ium b b
Z inc b
Z ircon ium ND
CONVENTIONAL PARAMETERS
Anvnon i a b b
F 1 uor ide . b b -
N it rate b b
RADIOBUCLmBS
Rad ium-226 d d
Rad ium-228 d d
a Does not includc pw.2M.
b Selected bucd on baYing a refcrence do5c value.
c Selected bucd on having a cancer slope factor.
d Selected bucd on having a pwdmum concentration abcM: 0.2 pCi/l for fann ponds and 0.68
pall for the plant baled on a personal communication from Region X EPA, May S, 1992.
ND .. Not detected
-------
provide an upper-bound estimate of the excess lifetime cancer risk associated with
exposure at that intake level. The term .upper bound. reflects the conservative
estimate of the risks calculated from the SF. Use of this approach makes it highly
unlikely that the actual cancer risk would be underestimated. SFs are derived from the
results of human epidemiological studies, or chronic animal bioassay data, to which
mathematical extrapolation from high to low dose, and from animal to human dose,
have been applied.
RfDs have been developed by EPA to indicate the potential for adverse health effects
from exposure to chemicals exhibiting noncarcinogenic effects. RfDs which are
expressed in units of mg/kg-day, are estimates of lifetime daily exposure for humans,
including sensitive subpopulations likely to be without risk of adverse effect. Estimated
intakes of contaminants of concern from environmental media (e.g. the amount of a
contaminant of concern ingested from contaminated drinking water) can be compared
to the RfD. RfDs are derived from human epidemiological studies or animal studies to
which uncertainty factors have been applied.
The Baseline Human Health Evaluation did not analyze risks from dermal exposure to
contaminants of concern because toxicity values for the dermal route of exposure do
not currently exist. The Baseline Human Health Evaluation relied instead on oral and
inhalation SFs and RfDs. The noncancer toxic endpoints (e.g. the affected organs) are
similar for dermal and oral exposure. The toxicity factors shown in Table 7-2 were
drawn from the Integrated Risk Information System (IRIS) or, if no IRIS values were
available, from the Health EffeCts Assessment Summary Tables (HEAST). For
chemicals which do not have toxicity values available at this time, other criteria, such
as the Maximum Contaminant Level Goal (MCLG) promulgated under the Safe
Drinking Water Act (SDWA) were used to assess toxicity.
7.1.4 Exposure Assessment
The exposure assessment identified potential pathways for contaminants of concern to
reach the exposed population. Exposure assumptions were based primarily on EPA
regional and national guidance, including EPA Superfund Standard Default Exposure
Factors, except where tailored to meet specific Site conditions. Current Site use is
industrial, except for the Soil Amendment Area (located within the Farm Ponds
Remedial Sector) which is currently being used for agricultural purposes. For this
reason, the Baseline Human Health Evaluation evaluates exposure to current and
future workers on the plant site, and to potential future residents in the Farm Ponds
Area. The Soil Amer"!dment Area and adjoining land to the northeast and northwest of
the Farm Ponds is currently being used for agricultural purposes. EPA further
supplemented the evaluation in the Farm Ponds Area by evaluating an agricultural
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CARCINOGENS Slo Factor Unit Risk Wei ht of Evidence
COMPOUND Oral Source Inhalation Source Oral Inhalation
Arsenic 2.00£+00 IRIS 4.30£-01 IRIS A A
Benzene 2.90E-02 IRIS 8.30£-06 IRIS A A
Chloroform 6.10E-03 IRIS 2.30E-05 IRIS B2 B2
Chromium VI 1.20£-02 IRIS A
1,2-Dichlorethane 9.10£-02 IRIS 2.60E-05 IRIS B2 82
1,1-Dichloroethene 6.00E-01 IRIS 5.00E-05 IRIS C C
Hexachlorobenzene 1.60£+00 IRIS 4.60E-04 IRIS B2 B2
1, 1, 2, 2-Tetrachloroethane 2.00E-01 IRIS 5.80E-05 IRIS C 82
Tetrachloroethene 5.10£-02 HEAST 5.20E-07 H£AST 82 82
Trichloroeth lene 1.10£-02 H£AST 1. 70E-06 HEAST B2 B2
a>
.to Vin 1 Chloride 1.90E+00 H£AST 8.40E-05 HEAST A A
Benzo(a)pyrene 7.30£+00 IRIS 1.70E-03 HEAST B2 B2
Benzo(a) anthracene * * * * * *
fluoranthene * * * * * *
fluoranthene * * * * . *
Chr sene . * . * * .
Dibenz(a,h)anthracene . * * . . *
Indeno(1,2,3-cd rene . . . . * *
Pol chlorinated bi hen Is 7.70£+00 IRIS B2
Slope factor, units - risk per milligram per kilogram of body weight per day {(mg/kg-daY)-l}
Unit Risk, units - risk per microgram Per cubic meter, {(ug/m3)-1}
* Indicates that risks were considered equivalent to Benzo(a)pyrene
IRIS - Integrated Risk Information System, USEPA, 1992
-------
CONFIDENCE
NON-CARCINOGENS REFERENCE DOSE LEVEL SYSTEM EFFECTED
COMPOUND Oral Source UF/MF Inhalation UF/MF Oral/
Source Inhalation
Acetone 1.00E-01 IRIS 1,000 NA Low Liver & Kidney
Chloroform 1.00E-02 IRIS 1 000 NA Med Liver
1,1-Dichloroethane . 1. OOE-Ol HEAST 1.000 5.00E-Ol HEAST 1.000 Kidney
1 I-Dichloroethene 9.00E-03 IRIS 1.000 NA Med Liver
cis1 2-Dichloroethene 1.00E-02 HEAST 3,000 NA Blood
MethylisobutYlketone 2.00E-02 IRIS 1.000 NA Liver Enz-Yme
1 1 I-Trichloroethane 9.00E-02 HEAST 1,000 1.00E+00 HEAST 1.000 Liver
1 1 2-Trichloroethane 4.00E-03 IRIS 1,000 Med Clinical Chemistry
Bis(2- 2.00E-02 IRIS 1,000 Liver
ethylhexyl I Phthalate
Hexachlorobenzene 8.00E-04 IRIS 100 Med Liver
Antimony 4.00E-04 IRIS 1,000 Low Clinical Chemistry
Arsenic 3.00E-04 IRIS 3 Med Skin
Barium 7.00E-02 IRIS 3 5.00E-04 HEAST 1. 000 Blood. Fetus
Cadmium 5.00E-04 IRIS 10 Kidney
Chromium 'total) 1.00E+00 IRIS 500 Low Not Reported
Coccer 3.70E-02 HEAST NR GI Tract
MaQnesium 9.70E+00 ECAO 1,000 GI Tract
Ma~anese 1.00E-01 IRIS 1 4.00E-04 IRIS 300 Med/Med CNS, ResDirator,y
Mercury 3.00E-04 HEAST 1.000 .3.00E-04 HEAST 30 Kidney. Nervous
Nickel 2.00E-02 IRIS 100 Med Body Weight
Thallium 7.00E-05 HEAST 3,000 Clinical Chemistry
Uranium 3.00E-03 IRIS 1.000 Kidney
-------
"
,..
CONFIDENCE
NON-CARCINOGENS REFERENCE DOSE LEVEL SYSTEM EFFECTED
UF/MF UF/MF Oral I
COMPOUND Oral Source I nha !at ion Source I nha lat ion
Z ircon ium 3 . OOE+OO ECAO 1.000 No E f fect Level
Ammon i a 6 . 00E-02 HEAST 1 Taste
Fluor ide . 6 00E-02 IRI S 1 Hiah Teeth
.
Nitrate 1 . 60E+00 I RI S 1 Hiah Blood
Re ference Dose , units - mi 1 1 igrams per ki logram 0 f body weight per day ( mg/kg/day )
UF - Uncerta inty Factor
MF - Mod ifyiny Factor
NA - Not avai able
NR - Not Reported
IRIS - Integrated Risk I n format ion System, USEPA , 1 992
HEAST - Health Effects Asses sment Summary Tab les , Annual Summary, USEPA , 1992
ECAO - Environmental' Cr iter ia and As sessment Of f ice , USEPA, Cincinnat i , 1992
RADIOHUCLIDES SLOPE FACTOR SOURCE WEIGHT OF EVIDENCE
COMPOUND I naest ion Inhalat ion
Rad ium-2 2 6D 1 . 20E- 10 3 . 00E-09 HEAST A
Rad ium- 2 2 8D 1 . OOE- 10 6 . 90E- 10 HBAST A
Thor ium-2 2 8 5 . 50E-1 1 7 . 80E-08 HEAST A
Thor ium-2 30 1 . 30E-1 1 2 . 90E-08 HEAST A
Thor ium-2 3 2 1 . 2 OE- 1 1 2 . 80E-08 HEAST A
D - Risks from decay products a 1 so inc luded
S 1 ope Factor , units - risk per unit picocurie intake or exposure ( risk/pCi~
-------
worker scenario in the, Soil Amendment Area.
Human exposure to chemicals in groundwater can occur through ingestion of drinking
water, by dermal contact during bathing, handwashing etc., or by inhaling chemicals
volatilized from water during showering, cooking, or other household activities. The
RI/FS determined that groundwater generally flows in a westerly direction below the
TWCA Site to the Willamette River. TWCA currently uses water supplied by the local
municipal system for drinking water purposes. Water used in TWCA's ongoing
manufacturing processes is taken from the Willamette River. In addition, a beneficial
use survey conducted during the RI/FS indicated current residences and industries in
the vicinity of the TWCA facility do not use groundwater for drinking water purposes.
For these reasons, the Baseline Human Health Evaluation concluded that there are no
current receptors for groundwater exposures. Therefore, only exposure of
contaminated groundwater to future workers on the main plant and potential future
residents in the Farm Ponds Area were evaluated.
Exposure point concentrations for the 1WCA Site Baseline Human Health Evaluation
were derived in a manner consistent with the EPA guidance to evaluate Reasonable
Maximum Exposures (RMEs). The RME is defined as the highest exposure that is
reasonably expected to occur at a site. In addition the Baseline Human Health
Evaluation includes information that incorporates both the average and the high-end
RME portions of the risk distribution. Presentation of the plausible range of risk allow
risk management decisions to incorporate the relative uncertainty in the risk estimates.
The average case exposure assumptions largely represent the 50th percentile values
within the population.
The exposure assumptions used to estimate potential RME and average case
exposures to chemicals of concern at the 1WCA Site are summarized in Table 7-3 for
groundwater. .
7.1.5 Risk Characterization
For carcinogens, risks are estimated as the incremental probability of an individual
developing cancer over a lifetime as a result of exposure to the carcinogen. Excess
lifetime cancer risk is calculated by multiplying the SF (see "Toxicity Assessment"
above) by the .chronic daily intake. developed using the exposure assumptions.
These risks are probabilities generally expressed in scientific notation (e.g. 1 x 10~).
An excess lifetime cancer of 1 x 10""' means that an individual has a 1 in 10,000
chance of developing cancer as a result of site-related exposure to a carcinogen
under the specific exposure conditions assumed.
The potential for non-carcinogenic effects is evaluated by comparing an exposure level
over a specified time period (e.g. lifetime) with a reference dose (see "Toxicity
-------
......-
Plant Area Farm Ponds
Area
Exposure Parameters Averaoe RME Averaoe RME
Exposed Individual Worker Worker Resident Resident
Body Weight (Kg) 70 70 70 70
Ingestion Rate(L/day) lL/day lL/day 1.4L/day 2L/day
Inhalation NA NA 10.3 15
Rate (m3/day)
Days/Year Exposed 250 250 275 350
Years Exposed 9 25 9 30
Not Applicable .-
NA =
-------
Assessment" above) derived for a similar exposure period. Hazard quotients are
calculated by dividing the chronic daily intake by the specific RfD. By adding the
hazard quotients for all contaminants of concern that affect the same target organ
(e.g. liver), the hazard index (HI) can be generated.
The RME provides a conservative but realistic exposure in considering remedial action
at a Superfund site. Based on the RME, when the excess lifetime cancer risk
estimates are below 1 x 10~ (1 in 1,000,000), or when the noncancer HI is less than 1,
EP A generally considers the potential human health risks to be below levels of
concern. Remedial action is generally warranted when excess cancer risks exceed 1 x
10-4. Between 1 x 10~ and 1 x 10-4, cleanup mayor may not be selected, depending
on individual site conditions including human health and ecological concerns.
The potential human health risks at the TWCA Site were characterized by estimating
risks on a sample-specific basis. This approach retains information on the geographic
distribution of risk throughout the study area. The sample specific risks were used to
distinguish specific areas of the TWCA Site that exceed risk-based levels.
A summary of non-cancer and cancer risks from worker exposure to groundwater
from the Farm Ponds, Extraction, Fabrication, and Solids Area Remedial Sectors at the
TWCA Site is presented in Table 7-4. This table summarizes the sample-specific non-
cancer His exceeding 1 or cancer risk estimates exceeding or equal to 1 x 10-4,
1 X 10-5, and 1 x 10~ based on RME scenarios developed for the Site. Cancer risk
estimates are independently summarized for chemicals and radionuclides.
As can be seen from Table 7-4, groundwater contains chemical concentrations that
exceed both the non-cancer HI of 1 and the cancer risk level of 1 x 10-4. The potential
exposure pathway evaluated was ingestion of groundwater.
For the main plant, EPA assumed a less conservative approach in that worke~s would
be potentially exposed to contaminated groundwater. Ingestion of groundwater from
the Extraction Area can subject workers to excess lifetime cancer risks of up to
4 x 10-3. Non-cancer risk estimates for workers ingesting groundwater from the
Extraction Area are as high as HI = 82.03. Excess lifetime cancer risk estimates for
workers ingesting groundwater from the Fabrication Area are as high as 6 x 10-3.
Non-cancer risk estimates for workers ingesting groundwater from the Fabrication
Area are as high as HI = 84.75. Ingestion of groundwater from the Solids Area can
subject workers to excess lifetime cancer risks of 1 x 10"". Non-cancer risk estimates
for workers ingesting, groundwater from the Solids Area are as high as HI = 15.98.
For the Farm Ponds Area, EPA utilized a more conservative approach. Since the
potential Mure use of the Farm Ponds Area is uncertain, EPA assumed that potential
future residents could be exposed to contaminated groundwater from this area.
-------
Hazard Index > 1. 0 Cancer Risk ~ 10.4 Cancer Risk ~ 10-5 Cancer Risk ~ 10~
Remedial Sector
Avera e RME Average RME Average RME Avera e RME
Farm Ponds Area
Chemical Risk - (Ing) 3/19 9/19 0/19 2/19 2/19 3/19 4/19 5/19
- (Inh) 0/19 0/19 0/19 2/19 2/19 4/19 4/19 5/19
Radiation Risk. NA NA 0/19 0/19 0/19 3/19 3/19 13/19
Extraction Area
Chemical Risk 7/10 7/10 1/10 6/10 4/10 7/10 7/10 7/10
Radiation Risk. NA NA 0/9 1/9 1/9 1/9 3/9 7/9
Fabrication Area
Chemical Risk 12/1S 14/1S S/lS 13/1S 11/1S 16/1S 16/1S IS/IS
Radiation Risk. NA NA O/lS O/lS O/lS 3/1S 3/1S 14 / IS
-..J
0
Solids Area
Chemical Risk 17/19 lS/19 0/19 2/19 1/19 6/19 4/19 8/19
Radiation Risk. NA NA 0/19 0/19 0/19 1/19 7/19 14/19
Background
Chemical Risk - Res. 2/5 5/5 0/5 5/5 5/5 5/5 5/5 5/5
- Occ. 1/6 3/6 0/6 3/6 3/6 4/6 6/6 6/6
Radiation Risk.- Res. NA NA 0/5 0/5 0/5 0/5 0/5 4/5
- Occ. NA NA 0/6 0/6 0/6 0/6 0/6 5/6
a :: Values listed are the number of groundwater wells in the remedial sector that had sample-specific
noncancer hazard index estimates exceeding 1.0 or excess lifetime cancer risk estimates of greater than or
equal to 1 x 10-4, 1 X 10-5, or 1 x 10-6 under assumed reasonable maximum or average case exposure
conditions.
NA = Not applicable.
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Ingestion of groundwater in the Farm Ponds Area can subject potential future
residents to excess lifetime cancer risks as high as 4 x 10"'. Non-cancer risk
estimates for potential future residents ingesting water from the Farm Ponds Area are
as high as HI = 5.50.
Non-cancer risk estimates for groundwater at the TWCA Site indicate that the primary
risk contributing chemicals are VOCs such as 1, 1-DCE, 1,1,1- TCA, and MIBK; metals
such as magnesium and manganese; and inorganic constituents such as ammonia,
fluoride, and nitrate. Well PW-28A in the Extraction Area had numerous chemicals with
hazard quotients above 1.
Cancer risk estimates for groundwater indicate that VOCs and arsenic are the primary
contributors to risks. Arsenic was present in groundwater, however, arsenic
concentrations are below the Maximum Contaminant Level (MCl) of 50 parts per
billion (ppb) established pursuant to the Safe Drinking Water Act, 42 U.S.C. 300f
(SDWA). The VOCs which contribute to cancer risk are 1,1-DCE, 1,2-dichloroethane,
TCE, PCE, and vinyl chloride.
7.2
Environmental Risk Characterization
To assess the environmental effects of the contaminants present at the TWCA Site,
TWCA conducted an evaluation of potentially affected terrestrial and aquatic species.
The environmental evaluation was conducted in three phases which are described
below:
In the first phase, chemical concentrations in sediment, surface water, and biota were
compared with concentrations demonstrated to be potentially toxic to terrestrial or
aquatic wildlife. Potentially toxic concentrations were identified from literature sources
or protective federal criteria such as the ambient water quality criteria (AWQC)
established pursuant to the Clean Water Act, 42 U.S.C. 1251 et seq. (CWA).
Chemicals occurring on Site at potentially toxic concentrations were identified as the
most important chemicals of potential concern, and were carried on to subsequent
phases.
During the second phase, the possibility of ecological impact at the TWCA Site was
measured directly using field studies to evaluate the ecological status of terrestrial and
aquatic communities, and by conducting laboratory toxicity tests.
In the third phase, the'results from each of the previous two phases were integrated
using a weight-of-evidence scheme. Any geographical correlations among media
concentrations of chemicals of potential concern, ecological status as determined by
-------
field surveys, toxicity testing results, and measures of exposure (e.g. tissue residues)
were examined to identify the likelihood of environmental impact.
7.2.1 Potential for Exposure and Toxicity to Ecological Receptors
Potential exposures to ecological receptors at the Site were estimated using
concentrations of contaminants which were detected during the AI. Contaminants
detected in surface waters at the TWCA Site include VOCs, metals, and other
inorganics such as ammonia and nitrate. Chemicals detected in sediments include
VOCs, HCB, PCBs, metals, and other inorganics such as ammonia and fluoride.
Exposure pathways with the highest likelihood of being complete include exposure to
aquatic organisms through direct contact with chemicals in surface water and
sediments, and secondary exposures to predators consuming fish containing body
burdens of chemicals. Analyses of tissues of aquatic organisms indicated the
presence of HCB and PCBs.
Some chemicals in surface water, sediment, and/or biota collected at the Site are
present at levels that may be toxic to aquatic organisms or predators. However, the
likelihood of sustained exposure to predators at maximum detected concentrations is
low, because the locations with maximum concentrations are the most centrally
located within TWCA's manufacturing facility, where the occurrence of predators is
least likely.
7.2.2 Ecological Response Assessment
Quantitative biological endpoints were measured during the AI which included benthic
organism diversity and abundance, terrestrial vegetative mass, and aquatic toxicity of
surface water and sediment. Qualitative biosurveys were conducted to evaluate
terrestrial habitat types and vegetation, wetlands, terrestrial wildlife occurrence, and
surface water aquatic organism occurrence. .
7.2.3 Evaluation of Causal Evidence Between Measured Exposures and
Ecological Responses
HCB and PCBs in creek sediments and fish tissues were above levels of concern and
were also the only chemicals that showed consistent geographical concentration
gradients. Therefore, results of biological effects studies were evaluated to see if
responses align with in-field exposure estimates for HCB and PCBs. Table 7-5
summarizes the results of this comparison. This table shows that there may be a
correlation between eontaminated sediment from Truax Creek (sample location TC-S)
and the acute toxicity seen in aquatic species tested with this contaminated sediment.
However, other areas having the greatest potential for exposure in Truax Creek (TCB-
2, TCB-3), Third Lake (TLB-1 and TL-1), and Conser Slough (CSB-1) did not show
proportionate measures of effect for any response category.
-------
Aquatic Toxicity Testing Bioaccumulation
Study
Surface Water Sediment Concentrations
. in Fish Tissue
Biosurvey Acute Chronic Acute Total
Location PCBs. HCBI
FHM DM MT FHM FHH DM MT AMPH
Truax Creek 100 100 >45 0.470 100 95 >100 86.7 510 ND
Bank
Truax Creek NT NT NT NT 80 95 >45 91.1 2800 12000
Bank
,
-...I
I".J
Truax Creek 100 100 >100 0.445 95 20 >100 75.6 3800 28000
Bank " (75)c
Third Lake
Bank
NT
NT
NT
NT
100
90
>100
91.1
800
2400
Conser
Slough Bank
100
100
>100
0.520
100
80
>100
88.9
2000
1100
Murder
Creek Bank
NT
NT
NT
NT
NT
NT
NT
NT
ND
ND
Murder
Creek Bank
100
100
>100
0.473
100
100
>100
95.6
310
ND
Sediment
Concentration
Total
PCBsb HCBb
88 ND
7800 ND
935 ND
4000 ND
1110 94J
410 ND
16700 1193
1146 340J
380 ND
75 ND
NS ND
232 ND
39 ND
NS NS
NS ND
-------
...,
~
Aquat i c Tox i c i ty Te 8t 1ng B ioaccumu 1 at ion Sed imen t
Study Concent rat i on
S u r f ace Water Sed iment Conc ent r at ion 8
. i F i h T i
- n 8 8 8ue
B io 8 u rvey
Loc at ion Acu t e Chron ic Acute Tot a 1 Tot a 1
PCB 88 HCB8 PC B a b HCBb
FHM DM MT FHM FHM DM MT AMPH
Mu rde r NT NT NT NT 1 00 1 00 > 1 00 7 3 3 d 3 2 0 ND 2 1 9 ND
.
Creek B a nk
"; i
7 9 0 ND
Murde r 100 1 00 >4 5 O . 5 8 0 9 5 1 00 8 4 5 88 . 9 5 6 0 ND NS ND
Creek Bank
3 7 5 ND
Bu r khart NT NT NT NT 1 00 1 00 > 1 0 0 9 3 . 3 4 7 0 ND ND ND
Creek
Cont ro 1 100 1 00 - - O . 5 0 3 1 00 1 00 - - 9 6 . 7
A 1 1 c hemic a 1 con cent rat ion 8 i n ppb .
ND " Not detected at met hod detect 10n 1 im it 8
NT = Not te 8ted
PCB .. Po 1 yc h 1 or i nated b ipheny 1 8 ( reported a 8 t ota 1 0 f dete cted aroc 1 or concent rat ion 8 .
HCa = Hexach loroben ze ne
FHM .. Fat head mi nnow
DM " D aphn i a magna
MT = M i crotox
AMPH = Amph ipod (
8 Max imum detected t i 8 8U e concent rat io n 0 f t ot a 1 PCB 8 and HCB s are 1 i 8 ted .
b Ave detected concent rat ion i 1 i 8ted ' and wa s c a 1 cu 1 at ed f rom d at a co 1 lect ed du r i t hree sed ime nt ampl i
ra ge s n9 s n9
rou nd s .
c Second te at re au 1 t ed i n 7 5 percent au rv i va 1 .
d A s ign i f icant ( P
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7.3
Uncertainty in the Risk Assessment
The accuracy of the risk characterization depends in large part on the accuracy and
representativeness of the sampling, exposure, and toxicological data. Many
assumptions are intentionally conservative so the risk assessment will be more likely to
over-estimate risk than to under-estimate it.
The sample-specific approach used for the assessment of risks at the TWCA Site
could potentially over- or under-estimate risk. Much of the sampling was directed
rather than random. This could lead to higher calculated risks for suspected source
areas where concentrations of chemicals exceed average on-Site levels. Since the
sampling at the Site however was not exhaustive, under-estimation of risk may occur
as areas of higher concentration (Le. -hot spots-) may have been missed.
Another source of uncertainty is that the risk assessment assumed that there could be
exposure of workers to groundwater in the future. The groundwater beneath the Site
is not currently used as a drinking water source. Since the Site is zoned for industrial
use it is highly unlikely that groundwater beneath the Site would be used as a source
of drinking water in the foreseeable future.
Uncertainty in the toxicity evaluation may over-estimate risks by relying on slope
factors that describe the upper confidence limit on cancer risk for carcinogens. Some
under-estimation of risk may occur due to lack of quantitative toxicity information for
some contaminants detected at the TWCA Site. Qualitative uncertainty (over- or
under-estimation) exists when assuming chemicals that cause cancer in animals may
also cause cancer in humans.
Groundwater samples were not filtered because filtered samples may underestimate
chemical concentrations in water from an unfiltered tap. However, the fact that such
samples were not filtered may lead to an over-estimation of the risk at the TWCA Site
due to the presence of inorganic contaminants which are not dissolved in the -
groundwater.
Background concentrations could not be fully characterized, because background
locations were chosen, during the RifFS scoping and prior to characterization of the
Site, from areas which are potentially impacted by the Site. Adequate characterization
of background would allow risks attributed to the TWCA Site to be distinguished from
risks resulting from naturally-occurring chemicals.
A source of uncertainty which could lead to underestimation of risk is that chemical
concentrations in environmental media will remain constant over the assumed
exposure period. Because TWCA is an active operating facility, leaks or spills of
hazardous materials from pipes and structures could pose additional risks at the Site.
Analyses of the potential for future leaks and spills at the TWCA facility is beyond the
-------
scope of the Superfund cleanup. In addition, as the RI was only designed to
characterize contamination in areas which were not under existing buildings and
structures on the TWCA Site, it is uncertain whether contamination which may pose
further risks exists in the uncharacterized areas. Such risks could include potential
exposure to soil contaminants during remodeling or excavation of these structures. In
addition, long-term groundwater risks could be underestimated due to the potential
presence of contaminated groundwater beneath these structures. EPA has
determined that the uncertainties associated with this possible underestimation of risk
may best be dealt with as set forth in Section 10 of this ROD entitled .Selected
Remedy."
The assumption that concentrations will remain constant over the assumed exposure
period may also lead to over-estimation because some compounds may degrade or
disseminate over time.
Method detection limits for some chemicals detected in the RI (e.g. 1, 1-DCE, vinyl
chloride) were above concentrations that were of potential concem. For these
chemicals in this sample-specific risk assessment risks may be underestimated.
7.4
Conclusions
Worker exposure to groundwater at the Site could result in unacceptable lifetime
cancer and non-cancer risks. Worker exposure by ingestion of groundwater at the
Site could result in as great as 5 in 100 excess lifetime cancer risk.
Based on the results of the RI/FS, concentrations of contaminants of concern in
groundwater at the TWCA Site exceed chemical-specific health-based standards such
as the Maximum Contaminant levels (MCls) set under the Safe Drinking Water Act
(SDWA), 40 C.F.R. Part 141. EPA determined that risks from Site-related
contaminated groundwater to potential off-Site receptors need not be evaluated in the
RI, because a Groundwater Beneficial Use Survey conducted by TWCA as part of the
RI/FS concluded that groundwater wells in the immediate vicinity of the Site were not
attractive as drinking water supplies due to the groundwater aquifer's current inability
to produce enough water for potable use. The survey showed that off-Site
groundwater wells were used solely for industrial purposes. Since the off-Site
groundwater wells are not used to provide drinking water, no human exposure from
ingestion would occur. However, the RI/FS concluded that on-Site groundwater is
contaminated near the property boundary. This contaminated groundwater could
potentially migrate to, adjacent off-Site areas. In addition, the Groundwater Beneficial
Use Survey was limited in scope because it only evaluated adjacent areas to the east
of the TWOA facility, because the Willamette River is to the west of the facility and
groundwater generally flows towards the-river. Groundwater beneath and adjacent to
the Site could potentially be used as a drinking water source despite the fact that such
is not the cu"ent or projected use. Contaminated groundwater beneath the Site also
-------
e)
f)
discharges to adjacent surface water bodies including the Willamette River.
Sediments contaminated with PCBs and HCB were detected in many areas of the Site.
Detected concentrations of PCBs in sediments ranged from 88 ppb to 16,700 ppb.
Detected concentrations of HCB in sediments ranged from 94 ppb to 1,193 ppb.
Truax Fill material contains elevated concentrations of PCBs. Detected concentrations
of PCBs in Truax Fill ranged from 250 ppb. to 6,800 ppb. The RifFS indicated that the
highest concentration of HCB and PCB in sediments were found in portions of Truax
Creek. Therefore, the sediments of Truax Creek pose the greatest risk to fish and
mammals who may inhabit the area.
Actual or threatened releases of hazardous substances from this Site, if not addressed
by implementing the response actions selected in this ROD, may present an imminent
and substantial endangerment to public health, welfare, or the environment.
Based on the results of the risk assessment, and on the findings of the RifFS the
following remedial action objectives (RAOs) have been established for groundwater,
surface water and sediment at the TWCA Site. These remedial action objectives take
into account that TWCA is an active facility with ongoing manufacturing operations and
seeks to achieve remedial goals while minimizing adverse impacts on TWCA's ongoing
operations. .
For groundwater:
a)
Prevent people from drinking groundwater containing contaminant levels above
federal or state drinking water standards.
b)
Prevent contaminated groundwater above federal or state drinking water
standards from leaving the TWCA property boundary.
c)
Reduce the concentrations of TWCA-related organic, inorganic, or radionuclide
compounds in groundwater to concentrations below federal or state drinking
water standards or other risk-based levels.
d)
Prevent groundwater containing TWCA-related organic, inorganic, or
radionuclide compounds above federal or state standards from discharging into
nearby surface waters.
For sediments:
.
Prevent TWCA-related contaminants from moving into sediments, and from
sediments into surface water.
Prevent sediments containing TWCA-related contaminants from leaving the site.
-------
g)
Prevent aquatic organisms from coming in contact with contaminated
sediments.
h)
Reduce concentrations of "YWCA-related compounds in sediments where'
necessary, to protect aquatic organisms.
For surface water:
i)
Ensure that non-permitted discharges to surface water from the "YWCA facility
do not exceed federal or state water quality standards.
-------
8.0 DESCRIPTION OF ALTERNATIVES
The TWCA Site was divided into two areas in order to facilitate evaluation of remedial
alternatives. These areas are the Main Plant Area and the Farm Ponds Area. The
Main Plant Area was further subdivided into the Extraction, Fabrication, and the Solids
Area. Various remedial alternatives were analyzed in detail for each area of the Site,
except for the Solids Area. Sludges from two ponds located within the Solids Area
(Schmidt Lake and the LASP) were removed as part of an operable unit remedial
action. Post-removal confirmatory sampling of the former sludge ponds has not yet
been completed. Confirmatory sampling of the Solids Area will be conducted and
evaluated as part of the soils operable unit to determine if additional cleanup action is
required.
Estimated costs for each of the alternatives are accurate within the range of + 50
percent to -30 percent. Estimated present worth costs are based on a 3D-year life of
the remedial alternative using a discount rate of 5 percent.
All of the evaluated alternatives would result in contaminants remaining on-site above
health-based levels. Therefore, CERCLA requires that Site conditions be reviewed at
intervals of at least every five years. If warranted by the review, additional remedial
actions would be initiated at that time.
A total of seven remedial alternatives, including aNo Further Action a , were considered
for cleanup of contaminated ground water, and sediment at the TWCA Site. As part of
each alternative, the RI/FS also included an evaluation of options for cleaning up
chemically contaminated soil at the Site. These soil cleanup options are not
documented or evaluated in this ROD. Soil cleanup options will be evaluated as part
of the subsequent soil operable unit ROD.
Elements of the evaluated alternatives, excluding the aNo Further Action- Alternative,
are summarized in Table 8-1. Major federal and state applicable or relevant and
appropriate requirements (ARARs) for the Site are listed in Tables 8-2A and 8-28. A
description as to how the major ARARs would be met by each alternative is also
) provided in this Section.
8.1 Alternative 1 - No Further Action
The NCP requires that a ano actionu alternative be evaluated as a potential remedial
alternative for each Superfund site. For this alternative no further action would be
taken at the TWCA Site beyond those remedial measures which have already been
implemented (see Section 3.4 of this ROD). TWCA is an operating facility, and deed
restrictions are already in place which prohibit the use of groundwater below the
-------
..
Ca
in
of Surface Soils
ALTERNATIVE
2 3 4 5 6
X X X X X
X X X X X
X X X X
X X X X
X X X
X X
X
7
CLEANUP ELEMENT
Monitorin
Institutional Controls
x
x
Ground Water Extraction'
x
Slope Erosion Protection Truax Creek
Sediment Removal
X
X
X
Dilution of Soil Contamination in Feed
Makeu Area
X
co
C>
Source Reduction
x
Present Worth Cost-30 Years ($ Millions)
Time to 1m lement (Years)
1.29
0.25
2.03
1
3.80
1
5.31
1
6.93
1
7.50
1
, = The number of wells in which ground water would
3 through Alternative 6. (Alternative 3 . 3 wells;
Alternative 6 = 36 wells.)
be extracted progressivety increases from Alternative
-------
00
page 1 of 7
'" . .
FEDERAL CHEM:tCAL~j.. .. .Ti))~e a-:ZA . ... ......... .. .
. LOCATION-iAND ACTION;;iSl'iECIFIC. . AltARs
..
. '.. . .. . .
Chemicai~sP8bific~ Citation... Prert!Quielte ...ReaUlrement. Location Alternative
. Applicable RequiremeD~
1. National Primary ' Safe Drinking Off-property drinking
Maximum permissible Sitewide 2, 3, 4, 5,
Drinking Water Water Act (SDWA) water supplies, if level of contaminant 6, and 7
Regulations 40 CFR 141 these wells are which may be
community wells that delivered to user of
serve more than two public water system.
residences. MCLs and
MCLGs for arsenic,
. copper, lead, mercury,
PCBs, selenium, silver,
zinc, nitrate,
chlorinated
hydrocarbons, and total
trihalomethanes.
. RelevaD~ aDd Appropriate Reauire.eD~
1. Standards for 40 crR 192 Applies to the Standards for Sitewide 7
Management of Subpart D management of Uranium application during
Uranium Byproduct byproduct materials processing operations
Materials under Section 84 of the and prior to the end
Pursuant to Atomic Energy Act of of the closure
Section 84 of The 1954, as amended, period.
Atomic Energy Act during and following
of 1954, as processing of uranium
amended ores, and to
restoration of disposal
sites following any use
of such site.
2. National Primary Safe Drinking RAOs for onsite and Maximum permissible Sitewide 2, 3, 4, 5,
Drinking Water Water Act (SDWA) offsite groundwater. level of contaminant 6, and 7
Regulations 40 CFR 141 ' MCLs and MCLGs for which may be
arsenic, copper, lead, delivered to user of
mercury, PCBs, public water system.
selenium, silver, zinc,
nitrate, chlorinated
hydrocarbons, and total
-------
00
N
.. ...'
c., ":'"",,, ..,,:.
.' "" :-"--",.::',',',,',"'.
L
...,.", '.
. . . '. '.'.'.:.".'.'..'.". '..". ".:' '...,'. ,',
tod&Hon~spec if 16 .
. Applicable Require.eat
1. Waters in and
around the site.
2. Site Located in
areas of critical
habitat upon
which endangered
or threatened
spec ies depend
'.' . ".' '., . . ".' i'~le 8..2A. ..... "".'.""" ""
. ~~DE~ ReCiUirement
The four conditions
that must be
satisfied before
dredge and fill is an
allowable alternative
are:
. There must be no
practical
alternative.
. Discharge of
dredged or fill
material must not
cause a violation of
water quality
standards, or pose a
threat to aquatic
life.
. No discharge shall
be permitted that
will cause or
contribute to
significant
degradation of the
water.
. Appropriate steps
to minimize adverse
effects must be
taken.
The remedial action
will be designed to
conserve endangered
or threatened species
and their habitat.
LOcation
Surface
Water
Remedial
Sector.
Sitewide
page 2 of 7
Alternative
4, 5, 6,
and 7
2, 3, 4, 5,
-------
00
w
-'-c . .
page 3 of 7
". . r.
. .. . . Table 8~2A "'"
. .... ..... ... . .
.. . ... ..
FEDERALCHEM!~AL~, . . .......... ..
.: .. LOCATI()!I';;; i 'AIfI) AC::Tt()1f...~~ECIPic ARARs
., ,... ..,. .. ... ' ..,... .... . .. , .c. ........ ,......::... ,. .
. .. . . . . . I>
Location-st)ec:ifld ..c,.. c Citation ... PrerftouUite . '... :,.. ..:. R~ao.irftment : Location Alternative
3. Area containing Fish and Wildlife Activity affecting Remedial action will Surface 2, 3, 4, 5,
fish and wildlife Conservation Act wildlife and non-game conserve and promote Water 6, and 7
habitat. . of 1980; 16 fish. conservation of non- Remedial
U.S.C. 2901; 50 game fish and Sector.
CFR Part 83. wildlife and their
Fish and Wildlife habitats.
Conservation Act,
16 U.S.C. S661 et
sea.
. Releyant and Appropriate Requireaent .
1. Site located Protection of Remedial action will The remedial action Main 3, 4, 5, 6,
within a I Floodplains - take place within a will be designed to Plant and 7
floodplain Executive Order 100-year floodplain avoid adversely
11988; 40 CFR 6, impacting the
Appendix A floodplain wherever
possible to ensure
that the action's
planning and budget
reflects
consideration of the
flood hazards and
floodplain
manaaement.
2. Closure RCM 40 CFR Part Closure of hazardous Regulations to Former 3, 4, 5, 6,
Requirements 264, Subpart G waste repositories must minimize contaminant sludge and 7
meet protective migration, provide ponds in
standards. leachate collection, the
and prevent Solids
contaminant exposure Area; V2
will be met. Pond
3. Post-Closure RCM 40 CFR Part ' Closure of hazardous Protectiveness will Former 3, 4, 5, 6,
Requirements 264, Subpart G waste repositories must be achieved through sludge and 7
meet protective capping and ponds in
standards. institutional the
controls. Solids
Area; V2
-------
. . ..
. """"
Acticlhi.;sbeHr!.c ...
. Applicable Reauirement
1. CWA-NPDES
Industrial and/or
Stormwater
Discharge Permits
Regulations
2. PCB Storage and
Disposal
00
l:-
3. RCRA Land
Di8posal
Treatment
Standards
4. RCRA
Transportation
Regulations
..
..
.. .. ...... . ...
.. ... . . .... "TaSie"8~2A ..
riIDBRiL... ciil!ilicMa;~!~g~:{...~ ..A",;It~~gt~~PIC.ARAR.
. Citation ...pr~ti&Gi~f~i .....~.{ ir~n;~rit
.
NPDES 40 CFR S122
40 CFR S761.;60
40 CFR Part 268,
Subpart D
40 CFR Part 263
Discharges to waters of
U.S. must meet
standards established
under NPDES program
When PCBs and PCB items
are removed from
service and disposed
of, dispo8al must be
undertaken in
accordance with
reoulations
Determine whether
excavated 80ils and
debris exhibit RCRA
hazardous waste
characteristics
Determine whether
excavated soils and
debris exhibit RCRA
hazardous waste
characteristics
Treatment of water to
meet new permit
requirements
PCBs at
concentrations of 50
ppm or greater must
be disposed.of in an
incinerator which
comply with 40 CFR
761. 70.
A restricted waste
may be land disposed
only if an extract of
the waste or of the
treatment residue of
the waste developed
using the test method
in Appendix II of
Part 261 does not
exceed the value
shown in Table CCWE.
Establishes standards
which apply to
persons transporting
hazardous waste
within the United
States if the
transportation
requires a manifest
and 40 CFR Part 262.
Location
Onsite
surface
water
services
and
ponds
Sitewide
Sitewide
Sitewide
page 4 of 7
Alternative
3, 4, 5, 6,
and 7.
4, 5, 6,
and 7
3, 4, 5, 6,
and 7
4, 5, 6,
-------
.. .
... . .
. "... ... ..
. ...... ....." ....
.' FEDERAL CH:EiiICAL~'
'. :.. . ..,'., .;:"'.,..'" ... .' '..' :,'.,.,.::,.: ...,.' ",,:-.::::.'.
.' .. ..,.. ." '.:.'".'.".' .,',.
Action~SDeCiific ,.
. .
... '. "". ..
~~~i~~~":~f1o .~M~~iM~~C;~~f:~,AiliS ...
'" :...""""""pret~cNJ.site.i:~eqUfrement.. " '.
5. Occupational
Safety and Health
Act (OSHA)
00
V1
6. The implementing
regulations under
OSHA
7. Ambient Water
Quality Criteria
. Cltation..
29 U.S.C. S6S1
.
29 CFR Parts 1910
and 1926
40 CFR Part 131
Congress finds that
personal injuries and
illness arising out of
work situations impose
a substantial burden
upon, and hindrance to,
interstate commerce in
terms of lost
production, wage loss,
medical expenses, and
disability compensaticn
payments.
For on-site workers
implementing
remedial/cleanup
actions.
A water quality
standard defines the
water quality goals of
a water body, or
portion thereof by
designating the use or
uses to be made of the
water and by setting
criteria necessary to
protect the users.
Congress' purpose and
policy, through the
exercise of its
powers to regulate
commerce among the
several States with
foreign nations and
to provide for the
general welfare and
healthy working
conditions and to
preserve our human
resources.
No contractor or
subcontractor for any
part of the contract
work shall require
and laborer or
mechanic employed in
the performance of
other contract in
surroundings or under
working conditions
which are unsanitary,
hazardous, or
dangerous to his/her
health or safety.
Describes the
requirements and
procedures for
developing,
reviewing,
revisiting, and
approving water
quality standards by
the States as
authorized by Section
303(c) of the Clean
Water Act.
Location
Sitewide
Sitewide
Surface
Water
Remedial
Sector.
page 5 of 7
Alternative
2, 3, 4, 5,
6, and 7
2, 3, 4, 5,
6, and 7
2, '3, 4, 5,
-------
.. .
. .
... . ...
.. AcH~ioh';;Sped.fi6
8. Clean Air Act
(CM)
New Source
Performance
Standards
9. RCRA Air Emission
Standards for
Process Vents
co
0-
. . .
. FEDeRAL CiiEMtCAL~ i
. .Tllble a-2A .. .""...".......... ..
LOCATIO~~~."ANi> ACT:to8~8PECiFtC ARMs
..,.: '.':..'" .0
Citatiort .
40 CFR Part 61
.
40 CFR Part 264
Subpart AA
. To Be CoD.idere4 Material.
1. EPA Guidance on
Selecting
Remedies at
Superfund Sites
with PCB
Contamination
OSWER Directive
No. 935~.4-01
40 CFR 5264.552
40 CFR 5264.521
prerecruisite
For control of dust
particles emitted into
the air during
remediation activities.
For onsite air
emissions from
groundwater treatment
systems "
A Corrective Action
Management Unit (CAMU)
may be considered at
, the TWCA Site for the
purpose of temporarily
managing hazardous
wastes that are
associated with soil
removal at the Site.
ReCiulremE!nt
Emissions to the
atmosphere from
stationary sources
subject to the
provisions of this
Part.
Owner or operator of
the facility with
process vents
associated with
distillation,
fractionation, thin
film evaporation,
solvent extraction,
or air or steam
stripping operations
managing hazardous
waste with organic
concentrations of at
least 10 ppmw shall
either reduce total
organic emissions
from all affected
process vents at the
facility below 1.4
kg/h or 2.8 Mg/yr or
by 9S weight percent.
The'RCRA CAMUs
Provisions may be
used to manage wastes
that are generated at
a RCRA facility for
the purpose of
implementing remedial
actions required at
that facility.
Location
Main
Plant
Main
Plant
Sitewide
page 6 of 7
Alternative
2, 3, 4, 5,
6, and 7
2, 3, 4, 5,
6, and 7
4, 5, 6,
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Actio;i;';si)eClfic.
2. TSCA Spill
Cleanup Polley
CXI
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FEDERAL CItEMICAL~ ....
... .. ,
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J:bCA!~t>,N';';iANb.AC'l'to~~~Pj(:f.ric
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ARAIts
. . .
.. Citat.ion,'
40 CFR S761.120
.
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i'tE!li~qijiiHtEi
TSCA PCB Spill Cleanup
Policy provides
guidance on recommended
cleanup levels under
certain access
scenarios.
, ,
,'.' i\filWH:ement
The Superfund PCB
Guidance recommends
cleanup criteria for
remediation for PCB-
contaminated soil and
sediment. The
guidance also
recommends cap
designs which are
consistent with RCRA
guidance, and
specifies long-term
management controls
for PCB-contaminated
media.
,Location
Sitewide
page 7 of 7
Alternative
4, 5, 6,
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(XI
(XI
; 1 of 3
page
Table 8~2B . ".". .. ",. "."." "',,' . .
STATE OF OREGON CHEKICAL-, LOCATI~N~~' .ANriiCTtdj~SPECIFIC ARARs
'..
Chemical-specif1~I. . .. .
Citation Prerequisite Requ iiemerit Location Alternative
. Applicable Requirement
1. Oregon OR,S 465.315 Any removal or Remed ia I action that attains Sitewide 2, 3, 4, 5,
Environmental remedial action a degree of cleanup 6, and 7
Cleanup.Law performed. protective of human health
and the environment, is
cost-effective and uses
permanent solutions and
alternative treatment
technologies or resource
recovery; technologies.
Oregon's Environmental
Cleanup rules require the
environmental shall be
2. Oregon OAR 340-122- Determination of restored to background Sitewide 2, 3, 4, 5,
Environmental 040 removal, remed ia 1 level, unless the Director 6, and 7
Cleanup Rules action and degree of determines that remedial
and Standards cleanup necessary to actions designed to attain
assure protection of background level do not meet
the present and future the "feasibility"
public health and requirement of OAR 340-122-
safety. 090(1)(b), in which event
the environment shall be
restored to the lowest
concentration level in
accordance with OAR 340-122-
090.
3. Oregon Water OAR 340-41- Extracted groundwater Discharges to surface water Sitewide 2, 3, 4, 5,
Quality 445 which is discharge to shall be protec1;ive of human 6, and 7
Criteria for surface water. health and aquatic life.
the
Willamette 0
Basin
4. Oregon Health OAR 333-104 Establ ishes cleanup Sitewide 2, 3, 4, 5,
Division's standards for radionuclides 6, and 7
Radiation in environmental media
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eX)
\C
page 2 of 3
. . ..
. . ... ... ... T&b.ie..s:'2IL ... . ..
... .... "'d.,........ .
STATE OF o1teG6RCREJi:i:cAt,;;;;,LocATI6N;;;'~. AND ACTION-SPeCIFIC ARARs
. . .". .... >..:...... ... . .,:....'.. .. ....... ,:'..,.: .. .'."..
. ,.. .;.; , . .. " ..
Chemical-Specific> . Citation ... Prerequi81te ::..Ii /..;....'. ..ReqUirement, ,.,. ,. Location Alternative
1. Oregon's Air ODEQ Air ODEQ's Air Quality Air emissions resulting from Sitewide 2, 3, 4, S,
Program Quality Program are used as a Superfund remediation 6, and 7
DLvision' s screening tool to activities at the TWCA Site
Toxic Air determine if air will be monitored to ensure
Pollutant emissions from a that levels of air emissions
Program facUity are Toxic Air are not of concern.
Significant POllutants, and if the
Emission quantity is
Rates. significant to cause a
potential harmful
.; heal th effect. ;
.", . prereqUisite".. ' . ... .
LocAtion~speciflc Citation ' .....;...;.. ,'Req\airement Location Alternative
.'.:' :,':;." ,.;;.
I
. Applicable Require.eat.
1. Oregon's Goal S, Goal Those portions of the Remedial actions planned for Sitewide 2, 3, 4, S,
Statewide 6, Goal 7, TWCA Site that lie these areas will need to be 6, and 7
Planning and Goal 15 within the Willamette cleared through the City of
Goals River Floodplain Millersburg under its
Floodplain Ordinance
. Relevaat. aad Appropriate Require.eat.
1. The Oregon ORS 196.800- Removal and remedial Requires a permit from Sitewide 4, 5, 6,
Removal-Fill 196.990 actions at the site Oregon Division of State and 7
Law associated with soil Lands if 50 or more cubic
and sediment yards of material are
remediation removed or filled in
wetlands, streams, ponds or
other waters. Although
Section 121(e)(1) of CERCLA
specifies that permits are
. not required for remedial
, actions conducted onsite,
the substantive requirements
of the Oregon Removal-Fill
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o
page 3 of 3
. .
.... .... H"... ..... .....,. Table. 8~~B .. . .
.. STATEO:r OREGONCBEMICAL- r LdcATtOH~ i. utf ACTIOt:t"-SPECI1IC DARs
:T '.citation H H . .'..1:\
Action-speCific. pre%-tlitN ieite . Requirement Location Alternative
. Applicable Reauire.eDt
1. Oregon OM 340-110 To establish Persons must consult 40 CFR Sitewide 2, 3, 4, 5,
Hazardous requirements for 5761 in addition to this 6, and 7
Waste storage, treatment, Division and Division 120 of
Management and disposal and this chapter to determine
Rules for marking prior to all applicable PCB
PCBs disposal. manaaement reQUirements.
2. Oregon OAR 340-100 Control hazardous Persons must also consult 40 Sitewide 2, 3, 4, 5,
Hazardous waste from time of CFR Parts 124 Subpart A, 6, and 7
Waste generation through 260-266, 268, and 270, which
Management transportation, are incorporated by
Rules for storage, disposal, reference in OAR 340-100-
PCBs and treatment 002, to determine all
applicable hazardous waste
manaqement reQUirements.
3. Oregon OAR 340-101 To identify those Persons must also consult 40 Main 2, 3, 4, 5,
Standard residues which are CFR Parts 124, 261-266, and Plant 6, and 7
Applicable to subject to regulations 270 which are incorporated
Generator of of hazardous waste. by reference in OAR 340-100-
Hazardous 002, to determine all
Wastes applicable hazardous waste
manaqement reQUirements.
4. IdentiUcatio OAR 340-102 Establish standards Persons must also consult 40 Main 2, 3, 4, 5,
n and Listing for generators of CFR Parts 124, 260-266, 268, Plant 6, and 7
of Hazardous hazardous waste. and 270, which are
Wastes incorporated by reference in
OAR 340-100-002, to
determine all applicable
hazardous waste management
reQUirements.
. Relevant aDd Aoorooriate Reauir...nt
1. Oregon Standards for Owner Capping and excavation Sitewide 2, 3, 4, 5,
and Operators of Hazardous of soils, groundwater 6, and 7
Waste Treatment, Storage, pretreatment, and
and Disposal FacUities decontamination of
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operable unit sludge ponds for drinking water purposes. In addition, the TWCA
property is zoned for industrial use, and no zoning changes are planned for the
foreseeable future. The no further action alternative would not comply with the
remedial action objectives for the Site, as concentrations of contaminants which are
above acceptable risk levels would remain on Site.
8.2 Alternative 2 - Monitoring and Institutional Controls
Alternative 2 focuses on reducing or controlling risk exposure pathways. Identified
risks to human health would be addressed through institutional controls and
monitoring. Assuming no further releases, it is anticipated that reduction of chemical
concentrations in Site groundwater and sediments would occur over time through
natural attenuation. Monitoring would be used to determine when institutional controls
on groundwater use could be modified.
8.2.1 Institutional Controls
Both the main plant and Farm Ponds Area are currently zoned by the City of
Millersburg for heavy industrial use. TWCA's main plant has limited access. Access
to the main plant is controlled 24 hours per day by security guards.
Additional institutional controls in the form of deed restrictions on the construction and
use of groundwater wells for drinking water supply would be implemented on TWCA's
main plant. This type of control would eliminate the potential for ingestion exposure
while contaminants in groundwater are above risk-based levels.
Access controls at the Farm Ponds Area currently prevent contact with and exposure
to contaminants in the area. Access controls will continue to be used at the Farm
Ponds Area for as long as the area is used to manage TWCA's wastewater treatment
plant sludge. Restrictions on the use of groundwater at the Farm Ponds could also be
implemented by TWCA.
8.2.2 Monitoring
A ground water monitoring program would be implemented as part of this Alternative
to track the rate of chemical attenuation over time and follow changes in plume
characteristics. The monitoring program would include semi-annual monitoring of 16
perimeter and 17 source area wells located at TWCA. All of the samples except
samples from well PW-28A would be analyzed for volatile organics. Inorganic and
radionuclides would be monitored in all wells on a semi-annual basis.
The monitoring program for surface water and sediment would include collecting
samples at predesignated sampling stations on the plant site. The data would be
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used to evaluate the impact that natural attenuation of the chemicals in the sediment
may be having on surface water and sediment quality.
The surface water/sediment monitoring program identified for this alternative would
consist of annual monitoring of four surface water locations and three sediment
sampling locations at TWCA. The annual samples would be analyzed for HCB and
PCBs.
8.2.3 Estimated Cost
The present worth cost of the alternative for a 3D-year period is estimated to be
$1,289,000. The estimated time to implement this alternative is 3 months.
8.3
Alternative 3 - Groundwater extraction, Slope Erosion Protection,
Institutional Controls and Monitoring.
Alternative 3 includes the previously described components of Alternative 2 and adds
source control at the Feed Makeup Area (PW-28A) along with groundwater extraction
from specific wells in the Farm Ponds Area. Well PW-28A is believed to be in an area
where releases from the feed makeup process occurred prior to 1978. Groundwater
extraction from Wells PW-405 and 55 located at the Farm Ponds Area would also be
included to address potential risks in that area. The components of Alternative 3 not
included in Alternative 2 are described below.
8.3.1 extraction 01 Feed Makeup Groundwater
The currently approximated extent of groundwater contamination in the Feed Makeup
area is shown in Figure 8-1. The source of the chemicals detected in Monitoring Well
PW-28A is thought to be old process feed material (pre-1978) from spills and leaks in
the Feed Makeup area. With this alternative, the high levels of zirconium in -
groundwater from well PW-28A will be recovered for resource utilization. Under
current plant operating conditions, river water is added to zirconium tetrachloride in the
feed makeup process to attain the desired solution strength prior to separating out the
zirconium. Using extracted groundwater from well PW-28A in place of some of the
river water will enable the zirconium in the groundwater to be recovered as part of
TWCA's normal plant operations.
The groundwater may not have to be treated prior to use in TWCA's feed makeup
process because other hazardous substances contained in the groundwater should be
removed during the feed makeup process and eventually discharged and treated with
one of the wastewater streams in the existing wastewater treatment plant.
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The existing wastewater treatment would include adjustment of the low pH of the
extracted water from well PW-28A. The only potential limiting factor would be the
levels of radium and thorium in the groundwater. An assessment of the levels of
radionuclides which would enter the wastewater treatment system would be made
during remedial design.
Two extraction wells, PW-28A and a new extraction well installed adjacent to the Feed
Makeup Building, would be used to extract the groundwater. The two extraction wells
would pump the groundwater to a holding tank located near the Feed Makeup area.
The extracted groundwater would be fed into the feed makeup process as needed
and available. Extraction rates are expected to be approximately 1 gallon per minute
(gpm). An evaluation of the effectiveness of the extraction of groundwater in the Feed
Makeup area would be made within two years of implementation.
8.3.2 Groundwater Extraction at the Farm Ponds
The approximate extent of groundwater contamination in the Farm Ponds area is
shown in Figure 8-2. The proposed groundwater extraction system for removing the
organic compounds from the groundwater at the Farm Ponds would utilize existing
monitoring well PW-40S located near the southwest corner of the Farm Ponds, and a
new extraction well installed to the east of well PW-40S near well SS. Submersible
pumps would be installed in the two wells and the extraction lines would be piped to
the existing Farm Ponds system return flow sump. The extracted groundwater would
then flow with the Farm Ponds return flow to TWCA's wastewater treatment plant for
treatment and eventual discharge to surface water.
8.3.3 Slope Erosion Protection Along the North Bank of Truax Creek
This component of Alternative 3 seeks to prevent contaminated fill material on the
bank along the north side of Truax Creek from being eroded and carried into ::rruax
Creek. Geotextile covered by riprap would be used to provide slope erosion
protection. The slope erosion protection has been assumed to extend approximately
980 lineal feet along the north bank of Truax Creek, from where the creek enters the
TWCA plant to the road crossing just west of Pond 2 (Figure 8-3).
Vegetative cover would be removed from the slope with an articulated mower. After
the vegetation was removed, loose soil and soil high in organic matter would be
stripped from the slope with a track-mounted backhoe to provide a good base for the
geotextile. Any soil r~moved may contain PCBs and may, therefore, require special
handling and disposal. All removed PCB-contaminated material would be disposed of
in accordance with all applicable requirements.
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EXISTING F'ENCE
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8.3.4 Estimated Cost
The present worth cost of the alternative for a 3D-year period is estimated to be
$2,030,000. The estimated time to implement this alternative is 1 year.
8.4
Alternative 4 - Groundwater Extraction, Slope Erosion Protection, Removal
of Hot Spot Sediments in Truax Creek, Institutional Controls and
Monitoring.
Alternative 4 contains the same elements as Alternative 3 and adds groundwater
extraction from all areas or hotspots where groundwater concentrations exceed a 10-4
increased cancer risk, and sediment removal from a Truax Creek hot spot. The
extraction of groundwater from all wells where concentrations exceed a 10-4 risk
addresses the primary source areas or hotspots at TWCA, including the Acid Sump,
the Arc Melting Area, the area south of the Powder Metallurgy Building, Truax Fill, and
the southern Extraction Area. Feed Makeup and the Farm Ponds Area are addressed
as previously described under Alternative 3. Removing sediments from Truax Creek
addresses the primary location of contaminated sediments at TWCA, reducing or
eliminating the threat of off-Site migration or further environmental exposure. .
The components not described in Alternatives 2 or 3 are described below.
8.4.1 Groundwater extraction From Areas exceeding 10-4 Health-Based Risk
. Goals
The Risk Assessment identified seven distinct areas with chemical concentrations in at
least one groundwater monitoring well exceeding a 10-4 health-based risk goal. These
areas are the areas southwest of the Farm Ponds, Feed Makeup area, acid sump
area, Truax Fill, Arc Melting area, the area south of the Powder Metallurgy Building,
and the southern Extraction Area (Figure 8-4). -
Groundwater extraction at the Feed Makeup area and the southwestern portion of the
Farm Ponds (PW-40S and SS) has been described previously; the planned approach
for groundwater extraction under this alternative at each of the remaining areas is
presented below by area. In most cases, groundwater would be extracted from
existing monitoring wells and, except where noted, the groundwater would be
discharged directly through TWCA's existing wastewater treatment plant. The addition
of groundwater from all of these areas (approximately 20 gpm) would not affect the
existing operation of the wastewater treatment facility.
Groundwater from wells near the Acid Sump area would be pretreated via air stripping
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Figure 8-4
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to remove VOCs prior to being discharged to the wastewater treatment 1acility.
Groundwater from the Powder Metallurgy Building area would be pretreated to remove
PCBs via filtration and liquid-phase carbon adsorption prior to discharge to the
wastewater treatment plant. Contaminated groundwater from wells in the southern
Extraction Area, Arc Melting area, and in Truax Fill would not be pretreated, but
instead the water would be discharged directly to the nearest wastewater drain. An
evaluation 01 the effectiveness 01 extraction would be conducted two years after
implementation. 11 extraction is not effective, the extraction system may be adjusted,
and/or additional remedial actions may be required.
8.4.2 Sediment Removal from Truax Creek Hot Spot
This element 01 Alternative 4 includes provisions 10r removing sediment from a hot
spot in Truax Creek (fC-5, Figure 8-5). This area has the highest PCB
concentrations in the sediment at the Site. This element consists 01 removal 01
approximately 500 cubic yards 01 sediment from TC-5, dewatering it (If necessary),
and disposing of it in accordance with all applicable requirements. During the removal
action, the water in Truax Creek would have to be diverted and the groundwater in the
vicinity 01 the removal would have to be contained or controlled. Minimizing the
amount of water in the work area would reduce the possibility 01 spreading chemical
constituents through flowing water during sediment removal.
The ultimate disposition of the removed sediment will depend on its PCB
concentration. Removed sediment will be sampled and analyzed to determine the
PCB concentration level and then disposed of in accordance with all ARARs.
Following the removal of the contaminated sediments, the waterway would be
reconstructed or reclaimed to the extent necessary and practical. The disturbed area
around the creek and access road would be regraded and revegetated to reduce the
impact of the remediation.
8.4.3 Estimated Cost
The present worth cost 01 the alternative 10r a 3O-year period is estimated to be
$3,641,000. The estimated time to implement this alternative is 1 year.
8.5
Alternative 5 - Groundwater Extraction, Slope Erosion Protection, Removal
of Hot Spot Sediments In Truax Creek, Institutional Controls and
Monitoring. .
Alternative 5 addresses contaminated groundwater and sediment at the TWCA facility
with estimated risk levels exceeding 10-5. The primary element of this alternative is
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groundwater extraction at wells within potential source areas or hot spots on the Site
found to be exceeding the 10.5 health-based risk levels. Alternative 5 would include
the following actions:
.
.
Ground water and sediment monitoring
Institutional controls to prevent contact with chemicals in ground water
Slope erosion protection along the northern bank of Truax Creek
Removal and disposal of sediments from TC-5, an identified Truax Creek
hot spot
Ground water extraction from all wells with chemical concentrations at
~ levels exceeding a 10.5 increased cancer risk level
.
.
.
The first three components of this alternative have been described under Alternatives
2,3, and 4; the one new component of this alternative is discussed below.
8.5.1 Groundwater extraction from Wells exceeding 10-6 Health-Based Risk Goal
Under this alternative, all of the wells identified in the risk assessment as having an
estimated cancer risk level exceeding 10-5 would be addressed using groundwater
extraction and treatment. Areas of the Site with groundwater concentrations that
exceed 10.5 are shown on Figure 8-6.
As was the case in Alternative 4, groundwater would be extracted mostly from existing
monitoring wells and discharged to TWCA's existing wastewater treatment facility.
Pretreatment of extracted groundwater from specific areas as described in Alternative
4 would also occur under this alternative. However, additional groundwater which
would be extracted under Alternative 5 may meet existing surface water criteria
established pursuant to the CWA, and would not be pretreated prior to being
discharged. The additional groundwater which would be discharged under this
altern'ative would not affect current treatment plant operations. An evaluation of the
effectiveness of extraction would be conducted two years after implementation. If
extraction is not effective, the extraction system may be adjusted, and/or additional
remedial actions may be required.
8.5.2 Estimated Cost
The present worth cost of the alternative for a 3D-year period is estimated to be
$4,825,000. The estimated time to implement this alternative is 1 year.
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8.6
Alternative 6 - Groundwater Extraction, Slope Erosion Protection, Removal
01 Hot Spot Sediments In Truax Creek, Removal 01 Sediments In Surface
Water Remedial Sector, Soli Washing In Feed Makeup Area, Institutional
Controls and Monitoring.
Alternative 6 addresses all chemically impacted groundwater at the TWCA facility with
estimated risk levels exceeding 10-6. It also addresses groundwater, and sediment
contamination at the Site that exceed risk-based ARARs or have hazard quotients
exceeding one. Alternative 6 would include all of the components described under
Alternative 5, plus:
.
Ground water extraction and treatment from all of the wells exceeding a
10-6 risk level, a hazard index of 1, or risk-based ARARs.
Removal of all sediments found to exceed sediment remedial goals.
In situ flushing of source material at the Feed Makeup area (PW-28A) to
enhance and quicken groundwater remediation of that area.
.
.
8.6.1 Groundwater Extraction From Areas exceeding Risk Goals or ARARs
Based on sampling results from the RI field work, 36 groundwater monitoring wells
were determined to have calculated RME risk values equal to or exceeding 10-6,
hazard index (HI) values exceeding 1, and/or at least one average chemical
concentration exceeding MCLs or nonzero MCLGs.
All 36 of the wells would be addressed under this alternative. Of the 36 wells, 22 have
been previously described under either Alternatives 3, 4, or 5. All 36 wells are listed
on Table B-3 with an indication of their RME risk level, radioactive RME risk value, HI
value, any ARAR exceedance, and the remedial alternatives within which extraction
from the well is included. Only the wells not previously addressed are described
further as part of this alternative.
Groundwater from the additional wells would be extracted from existing monitoring
wells. With the exception of groundwater beneath the Ammonium Sulfate Storage
Area, as described below, the extracted groundwater would be sent to TWCA's
industrial wastewater treatment plant for treatment and discharge.
Groundwater located beneath the Ammonium Sulfate Storage Area in the Fabrication
Area contains significant amounts of ammonium and MIBK, which can be recovered
for reuse. Under this. alternative, the current monitoring well in the area would be used
as an extraction well to recover the chemicals in the groundwater. The extracted
groundwater would then be discharged directly into one of two TWCA existing process
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Location (Well).
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Ammonium
Truax Fill
Powder
Powder
Acid Sum
Acid Sum
Acid Sump
Acid Sum
Fabrication
Fabrication
Fabrication
V2 Pond
Spill Treatment (PW-22A)
Chemical Unload in
Chemical Unloadln
Southern Extraction Area (PW-25A)
RME Risk Value8
Radionuclides
RME
Risk Valueb
Alternatives
Addressed
Under
HI~1
ARAR
Exceedance(s)c
>10""
10.4-10.5
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>10""
3
x
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x
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X
X
X
x
X
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x X X
X X
X X X
X X X
X X
X X X
X X
X X
X
X X
X X
X
X X
X
x X
X X
X X
X
X X
X X
X
X X
X X
X X
X X
X
X
X
5
6
7
X
X X
X X
X X
X X
X X
X X
X X
X X
X X
X X
X X
X X
X X
X X
X X
X X
X X
-------
-
;:)
"
RME R i s k Va lue8 Rad ionu c 1 ides A 1 te rnat ive s
RME MAR Addres sed
Risk Va lueb H I~ 1 Exceedance ( s ) c Under
Locat ion > 10-4 1 0-4- 1 0.5 1 0.5- 1 O~ > 1 0-4 1 0-4- 1 0.5 3 4 5 6 7
.
50ut hern Extract ion Area (PW- 2 6A\ X X X X X X
Extract ion Area IPW- 2 7A) X X X X X X
Feed MakeuD IPW-2 SA) X X X X X X X X X
Powder Met a 1 lurav IPW-3 OA) X X X X X X
Farm Ponds IPW-40A) X X X X X
Farm Ponds IPW-4 05\ I X X X X X X X
Arc Me 1t inq ( PW- 4 2A ) X X X X X X
Farm Pond s ( PW-4 3 5 ) X X X X
Farm Ponds IPW-4 45) X X X X
Powder Met a 1 lu rQY (PW-4 SA) X X X X X X
Powder Met a 1 lurav IPW-4 6A) X X X X X
50ut hern Extract ion Area ( PW- 4 7A ) X X X X X X
5 ou t hern Ext ract ion Area (PW- 4 9A) X X X X
Ac id Sump IP Z - 1\ X X X X X
Farm Ponds ( N5 ) X X X X X
Farm Ponds (SD ) X X X
(55) I
Farm Ponds X X X X X X X
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treatment systems. A schematic flowdiagram 01 the V2 treatment system is shown in
Figure 8-7.
Effluent from the V2 treatment system and the overhead stream from the treatment
systems discharge to TWCA's ammonium stripping towers for ammonium recovery.
The bottoms from the stripping towers are discharged to the wastewater treatment
plant for additional treatment and surface water discharge.
8.6.2 Removal and Disposal of PCS-Contamlnated Sediments
This element would consist 01 removing approximately 5100 cubic yards of PCB
contaminated sediment from several areas throughout the Site (Figure 8-8).
. Approximately 3,600 cubic yards 01 sediment would be removed from the shallow
water bodies as described in Alternative 4.
The sediment in Conser Slough would require a deep water sediment remediation
approach. Dredging the sediment would produce some turbidity. The movement 01
silt outside of the work area could be minimized by the installation of a silt curtain. A
silt curtain consists of a vertical permeable fabric erected in a vertical orientation
around the work area. The sediment would be removed using a floating hydraulic
dredge. The sediment would be piped to a series of portable sedimentation tanks
where the liquid and solid materials would separate to the maximum extent practicable.
The liquid would be pumped to TWCA's wastewater treatment plant and the solids in
the tanks would be handled and disposed in accordance with all ARARs.
8.6.3 In Situ Flushing of Source Material at Feed Makeup (PW-28A)
Flushing of low-pH source material would be implemented in the area 01 the Feed
Makeup Building near well PW-28A to enhance the removal of a major source of
groundwater contamination at the Site. Water would be introduced into the ar~a using
shallow infiltration trenches. The water would then flow through the impacted soil to
be recovered and treated as described previously in Section 8.3.1 01 this ROD.
Additional subsurface source sampling would be conducted first in order to further
define the ~xtent of subsurface contamination in the area. Pilot testing would
simultaneously be conducted to evaluate the effectiveness of flushing of source
material. Effectiveness will be determined by the systems ability to increase pH levels
in contaminated sourCe material, and subsequently in groundwater. The increase in
pH levels should res41t in accelerated and efficient removal or recovery of metal
contaminants. Assuming that this technology proves effective, infiltration trenches
would be excavated along the northwest and southeast boundaries of the affected
zone. Clean water would be introduced through the infiltration trenches and allowed
to migrate into the affected subsurface source material. An extraction well would be
drilled through the middle of the affected area which would be used to extract the
-------
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Diagram of V2 Treatment
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AFFECTED 8-1:.'
ESTIMATED v AREAS AND
OLUME OF
SEDIMENT
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added water and any contaminants which may be dissolved. Clean water for the
system would be obtained from existing piping in the Feed Makeup Building.
8.6.4 estimated Cost
The present worth cost of the alternative for a 3D-year period is estimated to be
$6,779,000. The estimated time to implement this alternative is 1 year.
8.7
Alternative 7 - Source Reduction, Groundwater extraction, Slope Erosion
Protection, Removal 01 Sediments In Portions 01 Surface Water Remedial
Sector, Flushing 01 Source Material In the Feed Makeup Area, Stringent
Institutional Controls and Monitoring.
In consideration of lWCA's request, and so as to minimize adverse impact on TWCA's
ongoing manufacturing processes, EPA agreed to allow the RI/FS to be scoped and
conducted so as to exclude those areas of the lWCA facility where there were
ongoing operations. It was projected that investigation of those areas could be
conducted later in the process either at the RD fRA stage or as a continuing process
integrated into lWCA's ongoing operations each time a building or structure would be
razed or remodeled. Due to this approach, designed to allow lWCA to continue its
business activities relatively uninterrupted during the RifFS stage, several limitations on
the scope of the RifFS necessarily resulted. lhose limitations included data gaps for
areas underneath existing buildings and structures on the facility which could not be
investigated for potential environmental damage without seriously disrupting the
facility's operations. Because of those data gaps, Alternatives 1 through 6 do not take
into account potential negative environmental impacts of spills and leaks from ongoing
operations and from existing structures on the Site. In addition, EPA is concerned that
the discharge of extracted groundwater to lWCA's existing wastewater treatment
facility (as proposed by Alternatives 3 through 6) could potentially violate CWA ARARs.
Because of these concerns, EPA recognized that implementation of Alternatives 1
through 6 might not prove to be effective as a comprehensive long-term remedy for
groundwater at the lWCA Site. Therefore, EPA evaluated a seventh alternative.
Alternative 7 would incorporate all the elements of Alternative 6 with the following
additions and modifications:
8.7.1 Source Reduction
.
In order to ensure that negative impacts on the remedial action from potential Mure
leaks and spills from existing structures are minimized, an evaluation of source
reduction techniques to reduce or eliminate current and potential Mure releases of
contamination would be conducted. Potential sources of contamination from ongoing
-------
operations would be identified and process changes implemented to reduce or
eliminate the sources. These process changes would include, but may not be limited
to, identification and repair of spills and leaks in pipes, and improving maintenance
scheduling, and improved record keeping.
8.7.2 Pretreatment of Groundwater
Additional pretreatment of groundwater other than that already described for
Alternatives 4 and 5 may be necessary to meet ARARs prior to being sent to TWCA's
wastewater treatment facility. Section 402 of the CWA requires that effluent limitations
in NPDES permits be based in part upon treatment using the best practicable control
technology (BPT) currently available. TWCA's existing NPDES permit does not require
effluent limitations for VOCs. The RI/FS evaluated alternatives which include discharge
of some VOC-contaminated groundwater to TWCA's wastewater treatment facility
without pretreatment prior to discharge. This element of Alternative 7 would require an
analysis of BPT prior to discharge of contaminated water. BPT would then be
implemented to pretreat VOC-contaminated groundwater prior to discharge to TWCA's
wastewater treatment facility. It is anticipated that BPT currently available for treatment
of VaC-contaminated water would consist of air stripping and/or carbon adsorption.
8.7.3 Supplemental Source Evaluation at Feed Makeup Area
Additional source characterization and remediation in the Feed Makeup Area would be
conducted under this element of Alternative 7. In 1991, a pilot test and treatability
study was implemented by TWCA to determine the feasibility of extracting and treating
the contaminated groundwater from Well PW-28A. Approximately 28,400 gallons of
groundwater were extracted with no increase in pH O.e. no decrease in the acidity of
the groundwater). Based on the chemical composition in the contaminated
groundwater, the RI/FS concluded that the source of the contamination in well PW-
28A was pre-1978 feed material. The pilot test however has raised questions as to
whether there is a continual source of groundwater contamination. In addition, the
groundwater contaminant plume associated with well PW-28A extends beneath various
buildings, and ponds which are associated with TWCA's wastewater treatment facility.
The RI/FS concluded that soil flushing may not be effective in achieving cleanup
goals. However, because the RI/FS did not present adequate technical data to
support this' Conclusion, this element of Alternative 7 would require that additional
source remediation techniques be evaluated for the Feed Makeup Area which would
ensure that the entire contaminant plume and source is cleaned up to the cleanup
goals. Pilot and/or treatability tests would be conducted if necessary, to demonstrate
which technique would be most effective in remediating the source of contaminated
groundwater in this area. Upon conclusion of the pilot or treatability test, EPA in
consultation with DEC, and after receiving public comment, would select the
technology that would be implemented to remediate the source.
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8.7.4 ,Environmental Evaluation of Unlnvestlgated Areas
In order to ensure that cleanup goals for groundwater at the Site are achieved, an
environmental evaluation of previously uninvestigated areas beneath buildings and
structures would need to be conducted whenever TWCA discontinues use of any
pond, area, building, or structure on the TWCA site. Potential contamination from
these uninvestigated areas could possibly serve as a source to groundwater
contamination. The scope of the environmental evaluation would be designed to
determine whether there have been releases of contamination into the groundwater
beneath these structures. Potential releases of contamination from previously
uninvestigated areas could impede the ability of selected groundwater remedial actions
to achieve the established cleanup goals. Examples of ponds and areas that would
require an environmental evaluation include the unlined ponds at the facility, including
the Farm Ponds, ponds within the wastewater treatment plant, and areas under
buildings or pavement. The timing of these environmental evaluations would
accommodate TWCA's need to continue its ongoing manufacturing operations with
minimal interruption while also ensuring that continuing sources of contamination to
groundwater do not remain undetected.
EPA and DEO would review and approve any sampling and analyses plan submitted
prior to conduct of the environmental evaluation. EPA and DEO would also review the
results and conclusions of the reports submitted as a result of environmental
evaluations which are conducted at the Site. EPA and DEO review would occur at
least every two years until cleanup goals are achieved. The RI/FS estimated that it
would be take approximately 50 years to achieve the cleanup goals for groundwater at
the Site, regardless of which alternative was implemented. EPA has determined that
characterization and remediation of currently uncharacterized areas could potentially
expedite the achievement of groundwater cleanup goals. The environmental
evaluation reports would need to outline any sampling analyses, conclusions, and
cleanup actions that were conducted as a result of the environmental evaluations of
the previously uninvestigated areas. . -
8.7.5 Off-Site Groundwater Monitoring
Installation and sampling of off-Site monitoring wells would be conducted to ensure
that site-related contaminants which are above health-based levels and/or ARARs
have not migrated beyond the facility boundary. Should Site-related contamination
above health-based levels and/or ARARs be found in off-Site wells, groundwater
containment and/or cdntaminant reduction measures may be implemented. In
addition, should Site-related contamination be found in either an off-Site potable or
industrial well, an alternate source of water supply may need to be provided for those
affected community members.
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8.7.6 Estimated Cost
The present worth cost of the alternative for a 3D-year period is estimated to be
$7,500,000. These costs do not include costs for additional pretreatment of
groundwater, should additional pretreatment be required. Pretreatment is expected to
be via BPT. Additional pretreatment costs, if any, will be determined during remedial.
design. The estimated time to implement this alternative is 1 year.
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9.0 COMPARATIVE ANALYSIS OF ALTERNATIVES
The NCP requires that each remedial alternative analyzed in detail in the Feasibility
Study be evaluated according to specific criteria. The purpose of this evaluation is to
promote consistent identification of the relative advantages and disadvantages of each
alternative, thereby guiding selection of remedies offering the most effective and
efficient means of achieving Site cleanup goals. There are nine criteria by which
feasible remedial alternatives are evaluated. While all nine criteria are important, they
are weighed differently in the decision-making process depending on whether they
describe a required level of performance (threshold criteria), provide for consideration
of technical or socioeconomic merits (primary balancing criteria), or involve the
evaluation of non-EPA reviewers that may influence an EPA decision (modifying
criteria). The nine criteria are summarized in Table 9-1.
9.1
Threshold Criteria
The remedial alternatives were first evaluated by comparison with the threshold criteria:
overall protection of human health and the environment and compliance with ARARs.
The threshold criteria must be fully satisfied by candidate alternatives before the
alternatives can be given further consideration in remedy selection.
9.1.1 Overall Protection of Human Health and the Environment
This criterion addresses whether the remedial actions provide adequate protection,
and describes the mechanism for controlling risks for the different exposure pathways.
Alternatives 3 through 6 are all protective of human health and the environment to
varying degrees but are not as protective as Alternative 7. Alternative 7 is the most
protective because it employs groundwater extraction and treatment to reduce the
risks associated with VOCs, metals, and radionuclide contamination in groundwater;
removes PCB contamination in sediments; decreases the potential for Mure
contamination of sediments in Truax Creek due to slope erosion protection;
decreases the potential for further contamination of groundwater through
environmental evaluations of previously uninvestigated areas and source reduction
measures; and reduces the likelihood of groundwater or surface water contamination
migrating off Site. Alternative 7 is the only alternative that includes provisions for
identifying and minimizing the potential impacts of TWCA's ongoing operations on the
protectiveness of a s~lected remedial action.
Alternatives 3 through 6 would protect human health and the environment to varying
degrees. Alternative 6 would remove or destroy the currently known principal
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7)
.~
EPA ranks the alternatives considered against the following
nine evaluation criteria:
THRESHOLD CRITERIA:
1)
Overall protection of human health and the environment -
How well does the alternative protect human health and
the environment, both during and after construction?
Compliance with applicable or relevant and appropriate
standards (ARARs) - Does the alternative meet all
applicable or relevant and appropriate state and federal
laws?
2)
BALANCING CRITBRIA:
3)
Long-term effectiveness and permanence - How well does
the alternative protect human health and the environment
after completion of cleanup? What, if any, risks will
remain at the Site?
Reduction of toxicity, mobility, and volume through
treatment - Does the alternative effectively treat the
contamination to significantly reduce the toxicity,
mobility, and volume of the hazardous substance?
4)
5)
Short-term effectiveness - Are there potential adverse
effects to either human health or the environment during
construction or implementation of the alternative? How
fast does the alternative reach the cleanup goals?
Implementability - Is the alternative both technically
and administratively feasible? Has the technology been
used successfully on other similar sites?
6)
Cost - What are the estimated costs of the alternative?
How do costs of the alternative being evaluated compare
with costs of the other alternatives?
8)
MODIFYING CRITERIA:
9)
State acceptance - What are the state's comments or
concerns about the alternatives considered and about
EPA's preferred alternative? Does the state support or
oppose the preferred alternative?
Community acceptance - What are the community's comments
or concerns about the preferred alternative? Does the
community generally support or oppose the preferred
alternative?
-------
contaminants found in groundwater, and sediments at the Site. Alternative 6 includes
. removal of contaminated sediments which would mitigate threats to aquatic life.
Alternative 6 may mitigate a principal threat to groundwater contamination in the Feed
Makeup Area via flushing of source material. Alternatives 3 through 6 do not provide
for source reduction and for environmental evaluations of previously uninvestigated
areas. Source reductions and environmental evaluations are measures that would
ensure that protection of public health and the environment remains in effect in the
Mure because the effects of potential additional or uninvestigated sources of
contamination to groundwater would be minimized.
Alternatives 4, and 5 may be only partially protective because contaminants in
groundwater would still remain above health-based risk levels. Alternative 4 would
remediate groundwater above the 10"" risk level. Alternative 5 would remediate
groundwater above the 10.5 risk level. Under Alternative 3, groundwater contaminants
would remain in place which are above the threshold risk level of 10"".
The -no further action- (Alternative 1) and the alternative requiring only monitoring and
institutional controls (Alternative 2) are not protective because the principal threats to
groundwater, surface water, and sediment would still remain uncontrolled.
9.1.2 Compliance with ARARs
The purpose of this analysis is to evaluate the alternatives for compliance with the
major ARARs.
CERCLA requires that remedial actions satisfy all identified ARARs. These laws may
include among others, the Safe Drinking Water Act, the Resource Conservation and
Recovery Act, the Toxic Substances Control Act, the Clean Water Act, and state laws
with promulgated standards more stringent than the corresponding federal law.
An "applicable- requirement directly and fully addresses the situation at the site. It
would legally apply to the response action if that action were undertaken
independently from any CERCLA authority. A -relevant and appropriate- requirement
is one that is designed to apply to problems which are sufficiently similar to the
problem being addressed at the site, that it's use is well suited to the particular site.
The TWCA Site presently exceeds chemical specific ARARs in groundwater (Table 8-
.3). The Maximum Contaminant Levels (MCLs) and non-zero Maximum Contaminant
Level Goals (MCLGs) established under the federal Safe Drinking Water Act (40 C.F.R.
141) are the primary ARARs for groundwater cleanup at the TWCA Site.
Alternative 7 can meet all identified ARARs. The inclusion of a provision for
pretreatment in Alternative 7 ensures that this alternative would meet all identified
ARARs. Alternatives 3 through 6, proposed by TWCA, do not adequately provide for
-------
meeting treatment and performance standards established in 40 C.F.R. ~122 pursuant
to the CWA. Under Alternatives 3 through 6, groundwater extracted and discharged to
TWCA's existing wastewater treatment facility would be untreated. Discharge of
untreated groundwater with elevated concentrations of vacs could exceed AWaC for
protection of human health and aquatic life (40 C.F.R. ~131).
Alternatives 2 through 5 do not adequately provide for meeting chemical-specific
ARARs for groundwater because those alternatives allow groundwater contamination
to remain above federal MCLs at some locations. Those altematives rely on the
assumption that natural dilution of groundwater would reduce contaminants to cleanup
levels. However, the RifFS does not lay an adequate foundation to demonstrate
whether natural dilution would indeed be effective or to demonstrate how long natural
dilution would take, if ever, to reduce contaminants to MCLs. The mere assumption
that groundwater contamination above MCLs could be addressed by natural dilution,
without aggressive groundwater remediation, is an insufficient basis on which to build
the remedy.
The "no further action" (Alternative 1) would not be in compliance with chemical-
specific ARARs because groundwater contamination would remain above SDWA
MCLs.
The "no further action" alternative (Alternative 1) will not be considered further as it
does not meet the threshold criteria.
9.2
Primary Balancing Criteria
For those alternatives satisfying the threshold criteria (Alternatives 2 through 7), five
primary balancing criteria are used to evaluate other aspects of the potential remedies.
No single alternative will necessarily receive the highest evaluation for every balancing
criterion. This phase of the comparative analysis is useful in refining the relatiVe merits
of candidate alternatives for cleanup. The five primary balancing criteria are: Long-
term effectiveness and permanence; reduction of toxicity, mobility, or volume through
treatment; short-term effectiveness; implementability; and cost.
9.2.1 Long-Term Effectiveness and Permanence
This criterion evaluates the ability of a remedial alternative to maintain reliable
protection of human pealth and the environment over time, once cleanup goals have
been achieved.
Alternative 7 would be the most effective-alternative over the long-term because it
considers the impacts of potential contamination from uninvestigated areas, and from
ongoing operations at the TWCA facility. Under Alternative 7, uninvestigated areas
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would be remediated, if necessary. Releases of hazardous substances from ongoing
operations would also be mitigated under Alternative 7. Potential additional sources of
contamination would not be released into the environment thus ensuring that cleanup
goals are maintained.
Alternatives 4 through 7 would permanently remove chemical contaminants from
currently identified groundwater sources. In addition, Alternatives 6 and 7 would
eliminate a contaminant source in the Feed Makeup Area via flushing. Alternative 3
only addresses two identified sources of groundwater contamination. Identified
sources of groundwater not addressed by Alternative 3 include; the Ammonium Sulfate
Storage Area, the Powder Metallurgy, Building Area, the Emergency Services Building
Area, the Acid Sump area, the Arc-Melting Area, and the Soil Amendment Area.
Alternative 2 would not address any of the identified source areas.
The RIfFS did not lay an adequate foundation on which to make a determination
regarding whether natural attenuation, alone, would be an effective or timely means of
reducing groundwater contaminant concentrations to cleanup levels at the Site.
Alternatives 3 through 5 to some extent rely on natural attenuation to reduce
groundwater contaminant concentrations to cleanup levels. Alternatives 2 through ~
also rely on natural attenuation to maintain groundwater contaminant levels below
cleanup levels, once the cleanup levels are achieved. However, the mere assumption
that natural attenuation would, without aggressive groundwater remediation, be an
effective means of reducing groundwater contaminant concentrations is an insufficient
basis for the remedy.
Alternatives 4 through 7 would permanently mitigate ecological risks by removal of
contaminated sediments.
Institutional controls and monitoring (Alternative 2), without more, would not assure
permanence. Those actions alone (while useful in timely detection and prevention of
further contamination that might impact on the remedy) would not serve to reduce the
levels of contaminants at the Site. Effectiveness of institutional controls and monitoring
would require coupling those actions with other actions designed to reduce the
contaminant levels. The RifFS does not provide adequate foundation to demonstrate
whether natural dilution would be effective nor how long it would take, if ever, for
natural dilution to reduce groundwater contamination to MCLs. Institutional controls
and monitoring coupled with reliance on natural dilution (without additional
contaminant reduction measures) would be insufficient to assure a permanently
effective remedy.
9.2.2 Reduction of Toxicity, MObility, or Volume Through Treatment
This criterion evaluates the anticipated performance of the various treatment
technologies and addresses the statutory preference for selecting remedial actions
-------
that employ treatment technologies which permanently and significantly reduce toxicity,
mobility, or volume of the hazardous substances. This preference is satisfied when
treatment is used to reduce the principal threats at a site through destruction of toxic
contaminants, irreversible reductions in contaminant mobility, or reductions in the total
volume of contaminated media.
Alternatives 3 through 7 utilize groundwater extraction and treatment for resource
recovery to reduce contaminant volume. Alternatives 4 through 7 would employ some
pretreatment of groundwater contaminants via air stripping or filtration and liquid-phase
carbon adsorption prior to surface water discharge. Altematives 6 and 7 utilize
flushing techniques to reduce the toxicity of contaminants in the Feed Makeup area.
Alternative 2 does not employ treatment as a component of the remedy. With
Alternative 2 toxicity, mobility, and volume of the contaminants would remain
unchanged.
9.2.3 Short-Term Effectiveness
The short-term effectiveness criterion focuses on the period of time needed to achieve
protection of human health and the environment, and adverse impacts which may
occur during remedial construction and remedial action, until cleanup goals are
achieved.
All the alternatives would require a number of years to achieve groundwater cleanup
goals. However, Altematives 6 and 7 would utilize the most aggressive extraction and
treatment methods for groundwater remediation and the length of time needed to
achieve groundwater cleanup goals would be the shortest.
Cleanup goals for sediment would be achieved in the shortest period of time via the
sediment removal elements which would be conducted under Alternatives 6 and 7.
Slope erosion protection of Truax Creek via placement of riprap along the creek bank
(Altematives 3 through 7) would achieve the goal of prevention of further
contamination of sediment in Truax Creek within one construction season.
All the alternatives, with the exception of Alternative 2 (monitoring and institutional
controls) would create some level of short-term risk to workers during the period in
which construction occurs. Groundwater in the Feed Makeup Area is extremely acidic
and it would be necessary for workers to wear protective clothing while construction
activities are being cqnducted in this area. Since TWCA is a restricted access
industrial plant, the nearby community should not be impacted by construction
activities.
The short term risks to human health are primarily those associated with dust and air
emissions resulting from sediment excavation, debris handling, and off-Site disposal.
-------
These risks could be minimized by control of air emissions during construction
activities.
Removal of sediments (Alternatives 4 through 7) may pose a short term risk to
sediment and surface water ecosystems in the immediate vicinity of the disturbed
sediments. Reconstruction may be necessary and recovery of the ecosystem could
take several years. These potential effects can be minimized by using careful
excavation techniques.
9.2.4 Implementability
This evaluation addresses the technical and administrative feasibility of implementing
the alternatives, including the availability of materials and services required to construct
the remedy.
All of the alternatives can be implemented with varying degrees of difficulty. Alternative
2 (monitoring and institutional controls) would be the fastest and easiest to implement.
Alternatives 3 through 5 would be the next easiest to implement because all three
alternatives would require minimal materials handling from sediment removal.
Alternatives 6 and 7 would be the most difficult to implement due to the following: (1)
sediment excavation and removal would require extensive materials handling; (2)
flushing in the Feed Makeup area would require pilot testing prior to full scale
implementation; (3) sediment removal would require additional ecological
characterization prior to implementation to determine potential impacts to the local
ecosystem. Implementation of source reduction methods under Alternative 7 would
require a detailed assessment of TWCA's ongoing processes. The scope and
frequency of environmental evaluations would need to be determined under Alternative
7.
Groundwater extraction, treatment, and monitoring systems are readily implelT!entable.
Groundwater extraction is a proven technology and process services and equipment
are readily available. Discharge of pretreated and untreated groundwater to TWCA's
existing wastewater treatment system (Alternatives 3 through 7) would be readily
implementable and would not have an impact on the ability or capacity of the
wastewater treatment system to accept and treat the additional water.
9.2.5 Projected Costs
Present worth costs ~e used to evaluate and compare the estimated monetary value
of each remedial alternative. Present worth costs are determined by summing the
estimated capital costs and estimates of the discounted operation and maintenance
(O&M) costs over the projected lifetime of the remedial alternative. Estimated present
worth costs are based on a 3D-year life of the remedial alternative using a discount
rate of 5 percent. The costs for each alternative are summarized below:
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Capital cost $101;100
Alternative 2 Annual O&M $77,250
Present worth $1,289,000
Capital cost $500,000
Alternative 3 Annual O&M $99,250
Present worth $2,030,000
Capital cost $851,000
Alternative 4 Annual O&M $181,620
Present worth $3,641,000
Capital cost $975,000
Alternative 5 Annual O&M I $250,650
Pre~nnt worth $4,825,000
Capital cost $2,229,008
Alternative 6 Annual O&M $295,950
Present worth $6,779,800
Capital cost $2,417,800
Alternative 7 Annual O&M $300,000
Present worth $7,500,000
Alternatives that include comprehensive remediation of contaminated on-Site
groundwater, and sediment (Alternatives 6 and 7) have the most associated capital
and present worth costs. Alternatives that have the minimal amount of remedial work
associated with them (Alternatives. 2 and 3) have the lowest capital and present worth
costs. .
9.3
Modifying Criteria
The modifying aiteria are used in the final analysis of remedial alternatives and are
generally considered in altering an otherwise viable oItfsrnative rather than deciding
between very different alternatives. The two modifying aiteria are state and
community acceptance.
9.3.1 State Acceptance
.
The Oregon Department of Environmental Ouality (DEO) has been involved with the
development and review of the Remedial-lnvestigation, FeasibUity Study and protJOsed
Plan for the Site. DEO's comments have resulted in substantivg changes to these
documents. DEO has also been integrally involved in determining the cleanup goals
-------
for the TWCA Site. DEQ has indicated that the selected remedy as modified from the
Proposed Plan is acceptable.
9.3.2 Community Acceptance
EPA has carefully considered all comments submitted during the public comment
period. and has taken them into account during the selection of the remedy for the
TWCA Site.
Members of the community are most concerned about the economic impacts that
selected remedial actions would have on TWCA and on the community. TWCA and
community members are concerned that the selected remedy be cost effective relative
to the actual health benefit. Most members of the community have expressed concern
that a costly selected remedy would have a detrimentaJ effect on TWCA's ability to
compete and maintain its status as a viable local employer.
EPA responses to comments received during the public comment period are included
in the attact\ed Responsiveness Summary.
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10.0 SELECTED REMEDY
Based on CERCLA, the NCP, the administrative record, the comparative analysis of
alternatives, and public comments, EPA has decided to select a Superfund remedy for
groundwater and sediment at the TWCA Site which is EPA's Proposed Plan
(Alternative 7) as modified in response to public comment. Because TWCA is an
active facility with ongoing operations, the RifFS, prepared by TWCA, did not address
several major areas potentially affected by releases from the Site. Therefore, those
areas are not addressed by the selected remedy. Examples of unaddressed areas
include process areas currently within or beneath buildings and structures in which
hazardous substances may have entered the environment via past leaks or spillages.
The ensuing list of modifications to the Proposed Plan is further detailed in Section 12
of this ROD entitled -Documentation of Significant Differences. - The selected remedy
is modified from the Proposed Plan as follows:
.
Active groundwater extraction shall only be required for identified hot
spots and source areas at the Site, unless it is determined, via
groundwater monitoring and extraction system performance data that
groundwater RAOs and cleanup levels cannot be achieved within the
projected timeframe.
.
Pretreatment of groundwater prior to discharge to TWCA's existing
wastewater treatment plant shall be required if such pretreatment is
necessary to meet CWA requirements.
.
Remediation of surface and subsurface soil contamination at the Site will
be addressed in a subsequent Operable Unit ROD, Operable Unit Three.
.
Environmental evaluations of previously uninvestigated areas shall be
designed so as to minimize intei1erence with TWCA's ongoing operations
while achieving the stated RAOs for the Site.
.
Evaluation and implementation of source reduction techniques has been
eliminated. EPA and DEQ expect that TWCA will voluntarily and
responsibly work to reduce or eliminate all potential sources of
contamination in order to prevent further contamination and to help
ensure the effectiveness of the selected remedy.
.
Because of Site-specific conditions, as elaborated in Sections 3, 6 and 7 of this ROD,
and presented by the fact that TWCA is an active, operating facility, EPA has
determined that the selected remedy is the most appropriate means of achieving the
groundwater, surface water, and sediment RAOs described in Section 7.4. The
selected remedy combines containment, source remediation, and treatment measures
-------
to reduce risks to human health and the environment posed by contaminated
groundwater and sediments at the TWCA Site. The selected remedy consists of the
following:
For Contaminated Groundwater:
.
Remediation of groundwater via groundwater extraction in the Feed
Makeup area and at areas on Site where contaminant concentrations
exceed lifetime cancer risk levels of 10'" and/or substantially exceed
noncancer HI of 1 for worker exposure. Extraction shall continue until
contaminant concentrations in groundwater throughout the Site are
reduced to below SDWA MCLs, non-zero MCLGs, or cancer risk levels of
10-6 and noncancer risk HI < 1 for worker exposure, or until EPA in
consultation with DEQ determines that continued groundwater extraction
would not be expected to result in additional cost effective reduction in
contaminant concentrations at the Site. Contaminated groundwater in
exceedance of SDWA MCLs, non-zero MCLs, or cancer risk levels of 10-6
and noncancer risk HI > 1 for residential use shall be prevented from
migrating off the plant site, or beyond the current boundary of the
groundwater contaminant plume at the Farm Ponds Area.
.
Discharge of extracted groundwater to Teledyne Wah Chang Albany's
wastewater treatment plant. Pretreatment of groundwater to comply with
CWA requirements prior to discharge to the wastewater treatment plant.
.
Treatment or removal of subsurface source material near the Feed
Makeup Building on the main plant.
For Contaminated Sediments:
.
Slope erosion protection consisting of a geotextile covered by riprap
placed along the banks of Truax Creek to prevent contaminated fill
material from entering the creek.
.
Removal of approximately 3,600 cubic yards of contaminated sediments
from the surface water bodies adjacent to, or flowing through the Site.
Additional ecological characterization prior to removal to determine
potential impacts of sediment removal to the local ecosystem and to
provide,mechanisms to mitigate those impacts.
Site-Wide Actions:
.
Deed restrictions and institutional controls on land and groundwater use
for both the main plant and Farm Ponds area. The objective of this
-------
component of the remedy is to ensure that the property and groundwater
are used only for purposes appropriate to the cleanup levels achieved.
.
Environmental evaluations of currently uncharacterized potential
contaminant source areas, as needed to ensure achievement of
groundwater RAOs. The objective of this component of the remedy is to
ensure that contaminant source areas do not adversely impact the
remedy.
.
Long-term on-Site and off-Site groundwater, surface water, and sediment
monitoring which shall include at a minimum the monitoring of on-Site
wells which are in exceedance of MCLs and non-zero MCLGs, cancer
risk levels of 10~, and noncancer risk HI > 1 for residential exposure.
.
Review of selected remedy at least once every five years to ensure
protection of human health and the environment.
10.1
Contaminated Groundwater
10.1.1 Groundwater extraction and Containment
This element of the selected remedy utilizes a combination of volume reduction and
containment measures to manage and mitigate risks posed by groundwater
contamination at the TWCA Site. RAOs for groundwater at the TWCA Site have been
established in the RifFS and Proposed Plan which include the reduction of
concentrations of TWCA-related contaminants in groundwater to concentrations below
ARARs or other risk-based levels. Additional RAOs for groundwater at the TWCA Site
include: preventing contaminated groundwater above ARARs and risk-based levels
from migrating off Site, preventing human and environmental exposure to
contaminated groundwater, and preventing contaminated groundwater from
discharging into nearby surface waters. Cleanup levels which shall be obtained for
groundwater at the TWCA Site are shown in Table 10-1.
Eight hot spots at the TWCA Site have been identified with groundwater contamination
above the lifetime cancer risk level of 10" and/or a noncancer HI which is substantially
greater than 1. These areas are shown in Figure 10-1. The eight areas may also
serve as potential source areas to Site-wide groundwater contamination. These
potential source areas if not actively remediated will continue to contaminate
surrounding groundwater. Therefore, in order to achieve the RAOs for groundwater,
and reduce risk of exposure to contaminated groundwater, extraction shall be
implemented in the eight potential source areas. If additional areas are subsequently
found to exhibit groundwater contamination at or above the lifetime cancer risk level of
1 x 10'" and noncancer hazard index of 1, groundwater extraction shall be
implemented at those additional areas.
-------
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IDENTIFIED HOT SPOTS OR S2URCE AREAS OF~GROUNDWATER CONTAMINATION WHICH EXCEEDS LIFETIME
CANCER RISK LEVELS OF 10; AN~/OR SUBSTANTIALLY EXCEEDS LIFETIME NONCANCER HAZARD INDEX OF 1
-------
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HAZARDOUS SUBSTANCE
CONCENTRATION
119/1
BASIS
Benzene
5
5
MCl
MCl
MCl
HI= 1
1 O~ Risk
1,2-Dichloroethane (1,2-DCA)
1,1-Dichloroethene (t,1-DCE)
Methylisobutylketone (MiSt<)
1,1,2,2-Tetrachloroethane
Tetrachloroethene (PCE)
1 ,1,1- Trichloroethane (1,1,1- TCA)
1,1,2-Trichloroethane (1,1,2-TCA)
Trichloroethene (TCE)
Vinyl Chloride
7
5000
0.175-
5
200
3
MCl
MCl
Non-zero MClG
Hexachlorobenzene
5
2
1
MCl
MCl
MCl
Radium-228
Ammoniumb
5
5
MCl
MCl
SMCl
- SMCl
MCl
MCl
MCl
MCl
cOAR
cOAR
PAHs
Beryllium
Copper
0.2
1
1000
Manganese
Uranium
50
20
0.5
TOTAL PCBs
Radium-226
Fluoride
250,000
2,000
-------
H..H . ......>< . ..HH:H .....
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CLEANUPLEVELSHF=QRc;ROUNDYiATERAT THETWCASITE. .
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HAZARDOUS SUBSTANCE
CONCENTRATION
pg/I
. BASIS
Nitrate
10,000
MCL
Note: The following long-term cleanup levels have been established for groundwater
throughout the TWCA Site. These cleanup levels have been established In order to
achieve groundwater RAOs and ARARs. They are either the SDWA MCLs, non-zero
MClGs, or Oregon Drinking Water Standards. Hazardous substances detected on the
main plant which are shown on this list and for which no MCl, MClG, or state standard
exists shall be remedlated to the concentration which Is equivalent to the lifetime cancer
risk level of 1 O~ or noncancer hazard Index (HI) of 1 for Industrial exposure. Hazardous
substances detected at the Farm Ponds Area or. off Site which are shown on this Ust and
for which no MCl, MCLG, or state standard exists shall be remediated to the
concentration which Is equivalent to the lifetime cancer risk level of 1 O~ or non cancer
hazard Index (HI) of 1 for residential exposure.
Hazardous substances which are not on this list, but which have been previously detected
at the TWCA main plant, or which may be detected at the TWCA main plant In the future,
must be remedlated to the concentration which is equivalent to the lifetime cancer risk
level of 1 O~, or non-cancer HI = 1 for Industrial exposure. -
Cancer risk shall not exceed 10~for Industrial exposure at the main plant, and for
residential exposure at the Farm Ponds and off-Site areas.
The MCL for combined Radium-226 and Radium-228 is 5 picocuries per liter (pCi/I).
SMCL = Secondary Maximum Contaminant level (40 C.F.R. ~143.3)
In addition, the pH of ground water at the TWCA Site shall be between 6.5 and 8.5 in
accordance with the SMCL.
a - This level may be below the Practical Ouantitation Umit. Concentrations of this hazardous
substance must not be detected in ground water monitoring wells.
b = This contaminant is regulated as ammonium sulfate.
C = OAR 333-61-030 = State Drinking Water Standards.
-------
This element of the remedial action would be designed to achieve groundwater RAOs.
Based on information obtained during the RI and on the analysis of all seven remedial
alternatives, EPA and DEQ have determined that the selected remedy would be most
likely to meet RAOs throughout the Site.
Groundwater contamination may be especially persistent in the immediate vicinity of
contaminant sources, such as the Feed Makeup area where concentrations are
relatively high. The ability to achieve RAOs and cleanup levels at all points throughout
the affected areas cannot be determined until the extraction system has been
implemented and modified as necessary, and the plume response monitored over
time. If this element of the selected remedy is unable to fully achieve all the specified
RAOs and cleanup levels, at any or all of the monitoring points during implementation,
the contingency measures and standards described in Section 10.1.1.2 r Attainment of
Groundwater Cleanup Levels.) may be used to replace this element of the selected
remedy for those portions of the affected areas. Such contingency measures will
assure protectiveness by, at a minimum, preventing further migration of groundwater
contaminants. These contingency measures may include a combination of
containment technologies such as groundwater extraction and treatment and
institutional controls as needed to protect human health and the environment.
EPA considers these measures to be protective of human health and the environment.
10.1.1.1 Point of Compliance for Groundwater Remediation
In order to achieve the RAOs and cleanup levels established for groundwater at the
TWCA Site, groundwater extraction will be implemented at the Site using the following
conditions:
The preamble to the NCP (55 FR 8752), specifies that cleanup levels should be
attained throughout the contaminated plume, or at and beyond the edge of the
area where waste is left in place. As applied to the TWCA Site, cleanup levels
shall be attained throughout the contaminated plume. However, as TWCA is a
complex site with complex groundwater contamination due to the fact that it is
an operating facility, the approach to groundwater cleanup will differ within the
main plant property boundary as opposed to at or outside the property
boundary. A point of compliance shall be established at the main plant
property boundary (Figure 10-2). The point of compliance for the Farm Ponds
Area shall be the edge of the Farm Ponds themselves.
.
EPA has determined that the risks associated with areas of groundwater that fall
within the risk range of 10" to 10-6 can be effectively managed by groundwater
containment via gradient control, along with active remediation of identified
source areas, without such massive disruption of operations at the TWCA site.
-------
\j,Q
Point of
Compliance'
. EXTRACTION
:;:: AREA
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O.R; ROAO
Figure 10-2
POINT OF COMPLIANCE FOR
MAIN PLANT GROUNDWATER REMEDIATION
-------
In balancing TWCA's need to continue uninterrupted operations against the
need for a groundwater remedy that is effective and protective, EPA has
determined that the most feasible groundwater cleanup strategy is to initially
require that active groundwater remediation on the Site be applied only to
certain areas that have been identified as sources or hot spots. Therefore, the
potentially responsible party (PRP) shall actively remediate source areas and
hot spots within the point of compliance to the cleanup levels listed in Table 10-
1. The PRP shall address the primary source areas or hotspots identified in the
RI/FS by extraction of groundwater from all wells where concentrations exceed
a lifetime cancer risk level of 10-4 and/or non cancer HI substantially greater than
1, including but not limited to the Feed Makeup area, the Farm Ponds Area, the
acid sump area, the Arc Melting Area, the area south of the Powder Metallurgy
Building, Truax Fill, and the southern Extraction Area. If additional groundwater
source areas or hot spots are identified during remedial design or remedial
action, then the PRP shall also actively remediate those areas to the cleanup
levels listed in Table 10-1. At and outside the compliance points, the PRP shall
initiate groundwater extraction anywhere the cleanup levels are exceeded, or as
needed to meet RAOs. The ability of this initial approach of extraction of
groundwater only at primary source areas and hot spots to meet cleanup levels
and RAOs shall be evaluated periodically as described in Sections 10.1.1.2 and
10.1.1.3 of this ROD.
Results of the RI/FS have shown that groundwater in the Site perimeter
monitoring wells, outside of identified source areas, is above the cleanup levels
listed in Table 10-1. Therefore, the PRP shall implement containment actions to
ensure that the contaminated groundwater does not migrate off-Site or into
adjoining surface water bodies. Containment of contamination shall be
achieved via hydrodynamic .controls such as long-term groundwater gradient
control provided by low level pumping.
For the purposes of the Superfund remedial action the groundwater cleanup le\lels
shall be those levels as stated in Table 10-1. However, under certain circumstances,
other regulatory authorities may require that more stringent groundwater standards be
achieved within the TWCA property boundary. Such regulatory authorities would
include, but not necessarily be limited to, RCRA, which might require groundwater
corrective action as a result of any releases from RCRA regulated units at the TWCA
facility. Should releases from a RCRA regulated unit, or any other unit, impact the
Superfund remedial action, Superfund groundwater cleanup standards shall be
consistent with the m9re stringent requirement.
10.1.1.2 Attainment of Groundwater Cleanup Levels
The purpose of the groundwater extraction is to expedite the eventual attainment of
Site-wide groundwater cleanup levels. The PRP shall continue groundwater extraction
-------
until cleanup levels are achieved. The projected timeframe for such groundwater
extraction is an estimated period of 15 years. This timeframe may be modified as
additional data is collected and the contaminant plume response is evaluated during
groundwater remediation. Determination to improve, modify. or augment the
groundwater remedy, or as to whether groundwater cleanup levels are achievable,
shall be made by EPA. in consultation with DEC, as described below.
Three years after commencing operation of the extraction system an EPA-approved
historical and statistical analysis of groundwater contaminant concentrations shall be
conducted by the PRP. If this or any later analysis indicates that contaminant
concentrations in groundwater at any location on the Site are not likely to decline to
cleanup levels within 15 years after commencement of operation of the extraction
system, the existing extraction system may be modified, at EPA's discretion after
consultation with DEO. as described below:
a) At individual wells where cleanup levels have been attained. pumping may
be discontinued;
b) Alternating pumping may be conducted at wells to eliminate stagnation
points;
c) Pulse pumping may be conducted at wells to allow aquifer equilibration and
to allow adsorbed contaminants to partition into groundwater;
d) Additional extraction wells may be installed at EPA-approved locations to
facilitate or accelerate cleanup of the contaminant plume and help ensure
achievement of groundwater RAOs within the projected 15-year remediation
timeframe;
e) Additional extraction measures may be conducted in source areas or hot
spots which are delineated as a result of environmental evaluations or as a
result of any other additional sampling which is required by the selected
remedy.
If EPA in consultation with DEO determines on the basis of the system performance
data that certain portions of the affected groundwater areas cannot be fully restored to
cleanup levels. some or all of the following measures involving long-term management
may be required to be implemented by the PRP for an indefinite period of time as a
modification of the exi~ting system:
a) If groundwater contaminant concentrations increase, and/or the
contaminant plume expands, and/er contaminant concentrations are not being
reduced by remedial actions already in place. the PRP shall institute engineering
controls. including measures such as physical barriers, or long-term gradient
-------
control provided by low level pumping, as containment measures;
b) If contaminant concentrations are not reduced to cleanup levels, the PRP
shall maintain institutional controls to restrict access to portions of the affected
groundwater which remain above cleanup levels;
c) If, based upon the sample monitoring data EPA in consultation with DEO
determines that it is necessary in order to ensure attainment of cleanup levels,
the PRP shall continue monitoring of specified wells; and
d) If groundwater cleanup levels cannot be achieved by remedial actions
already in place, the PRP shall conduct periodic reevaluation of remedial
technologies for groundwater restoration.
For those on-Site areas in which groundwater contamination is above cleanup levels
but EPA in consultation with DEQ has determined that active groundwater remediation
(Le. extraction) is not required, the PRP may then rely on natural attenuation to aid
reduction of the chemical concentrations in these areas to cleanup levels. During
periodic review of the groundwater extraction system, the PRP shall conduct
evaluations to determine the rate of natural attenuation and to determine whether the
RAOs and cleanup levels are likely to be reached through natural attenuation within
the projected 15 year groundwater remediation timeframe. If those evaluations
indicate by historical sampling and analysis of extraction and monitoring wells that
natural attenuation is unlikely to achieve the desired objectives, the PRP shall then
implement increased extraction.
Groundwater contamination above cleanup levels must be contained on Site. Natural
attenuation can only be relied upon to reduce those non-source areas of on-Site
groundwater contamination with lifetime cancer risk levels less than 10-4 and
noncancer HI = 1.
10.1.1.3 Groundwater Extraction System Monitoring
The PRP shall monitor the groundwater extraction system's performance initially on at
least a quarterly basis. On approval by EPA after consultation with DEO, the PRP may
be permitted to reduce the frequency of monitoring. The PRP shall conduct
monitoring of the groundwater extraction system until cleanup levels are achieved.
The PRP shall design the monitoring system to evaluate the effectiveness of the
groundwater extraction system with respect to the following:
a) horizontal and vertical extent of the plume(s) and contaminant
concentration gradients;
-------
b} rate and direction of contaminant migration;
c} changes in contaminant concentrations or distribution over time; and,
d} effects of any modifications on the ability of the extraction system to
achieve cleanup levels.
To ensure maintenance of cleanup levels, the PRP shall continue to monitor
groundwater at least yearly for a minimum period of 5 years after cleanup levels are
achieved at those wells where pumping has ceased. '
-10.1.1.4 Decision to Modify Groundwater Remedial Actions
The decision to pursue any or all of the modifications to the remedial actions
described in Section 10.1.1 of this ROD shall be made at the discretion of EPA in
consultation with DEQ.
,
10.1.2 Pretreatment and Discharge of Extracted Groundwater
Under this element of the selected remedy, extracted groundwater may be discharged
to TWCA's wastewater treatment plant. This treatment plant currently treats and
discharges wastewater from TWCA's ongoing processes to Truax Creek under an
NPDES permit. Truax Creek discharges into the Willamette River. .
Section 301 (b}(1) of the CWA requires the establishment of limitations in permits
necessary to meet water quality standarQs. Discharges to Oregon state waters must
also comply with limitations imposed by the state as part of its certification of NPDES
permits under section 401 of the CWA.
The NPDES regulations at 40 C.F.R. 122.44(d}(1} require that permits include limits on
all pollutants or parameters which "are or may be discharged at a level which will
cause, have the reasonable potential to cause, or contribute to an excursion above
any State water quality standard, including State narrative criteria for water quality" (54
Fed. Reg. 23868-23899; June 2, 1089). Oregon Water Quality Criteria (promulgated in
Table 20 of OAR 340-41-445) for certain contaminants found in groundwater at the
TWCA Site are shown in Table 10-2.
Section 402 of the CWA requires that effluent limitations in NPDES permits be based in
part upon treatment using the best practicable control technology (BPT) currently
available. Because discharge of VOCs was not envisioned at the time the existing
TWCA NPDES permit was issued, the permit does not require effluent limitations for
VOCs. However, the RifFS evaluated alternatives which include discharge of some
VOC-contaminated groundwater to TWCA's wastewater treatment facility without
pretreatment prior to discharge. Therefore, in order to comply with Section 402 of the
-------
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HAZARDOUS SUBSTANCE
1 ,1-Dichloroethene (1,1-DCE)
1,1,2-Trichloroethane (1,1,2-TCA)
CONCENTRATION
0.033 /Jg/lb
0.6 /Jg/I
2 /Jg/I
0.079 ng/lc
4,000 /Jg/I
10,000 /Jg/I
Vinyl chloride
Total PCBs
Fluoride
Nitrate
a = Water Quality Criteria are for protection of human health (OAR 340-41-445,
Table 10 and Table 20)
b /Jg/I = micrograms per liter
C ng/I = nanograms per liter
Discharge of radionuclides (radium-226, radium-228, isotopes of uranium) shall be
no greater than concentrations allowed for unrestricted area limits in accordance
with Appendix A, OAR 333-104-015
-------
CWA, this element of the selected remedy requires that the PRP conduct an analysis
of BPT during remedial design. The PRP shall recommend the BPT to be used for
pretreatment, which EPA in consultation with DEO shall approve. Upon EPA approval,
the PRP shall then implement BPT to pretreat VaC-contaminated groundwater prior to
discharge to TWCA's wastewater treatment facility. Examples of areas of the Site
where pretreatment of extracted groundwater using BPT may be necessary include the
Feed Makeup area located in the Extraction Area of the main plant, and the Acid
Sump area and area near the Powder Metallurgy Building located in the Fabrication
Area of the main plant. At this time, based on the information currently available, it is
projected that BPT for treatment of VaC-contaminated water would likely consist of air
stripping and/or liquid-phase carbon adsorption.
Based on the information currently available, another example of BPT that is projected
to be utilized at the Site as part of the selected remedy is resource recovery.
Resource recovery would involve using extracted groundwater from the Feed Makeup
area in place of surface water that is currently being used by TWCA in its ongoing
processes. Placing the extracted groundwater from the Feed Makeup area into
TWCA's process stream would enable recovery of zirconium that is currently in
solution in the groundwater. Additional contaminants such as vacs which could not
be treated or recovered by this process would be pretreated prior to discharge to
surface water.
10.1.3
Removal/Treatment of Subsurface Source Material Near the Feed
Makeup Building
This element of the selected remedy seeks to reduce the levels of contaminants in the
Feed Makeup source area in order to protect groundwater. Based on the results of
the RI, the source of the extremely low pH in the groundwater at well PW-28A has
been postulated to be buried pre-1978 feed solution which was previously used in
TWCA's ongoing processes.
The PRP shall first conduct additional sampling in order to further define the extent of
subsurface contamination in the area. The PRP shall simultaneously conduct pilot
testing to evaluate the effectiveness of removal of contaminants in the subsurface
source material via flushing of the source material with water. The criteria for
determining effectiveness shall be the ability of the flushing technology to increase pH
levels in contaminated source material in the short term, and subsequently decrease
contaminant concentrations in groundwater over the long term. In addition, there
would be a short term increase in the solubility and mobility of metal contaminants in
source material which 'would then result in flushing of those contaminants from the
source material to the extraction well. Once the contaminants are flushed from the
source material a decrease in contaminant concentrations in the groundwater would
then result. If the pilot test proves effective, the PRP shall excavate infiltration trenches
along the boundaries of, or within the affected zone. The PRP shall introduce clean
-------
water through the infiltration trenches and allow the clean water to migrate into the
affected area. The PAP shall drill an extraction well through the middle of the affected
area and shall use the extraction well to extract the added water and any contaminants
which may be dissolved in the water. The PAP may pretreat this extracted water
and/or utilize the water for recovery of zirconium, prior to discharge to TWCA's
wastewater treatment plant.
The PAP may obtain clean water for the system from existing piping in the Feed
Makeup Building. The PAP shall monitor the system to ensure that the additional
water does not spread contamination outside of the capture zone. Should
contamination spread, containment via gradient control and/or source removal actions
shall be implemented by the PAP.
The PAP shall conduct an evaluation of the effectiveness of the flushing technology
three years after implementation of this element of the selected remedy. EPA and
DEO, in consultation with TWCA, will determine the feasibility and/or effectiveness of
flushing which shall be determined based upon the results of sampling and monitoring
data and the ability of the flushing technology to achieve AAOs.
Should pilot testing show that flushing of the source material is not feasible, or should
the three-year evaluation show that implementation of source flushing is not effective in
achieving AAOs, EPA may determine that additional remedial actions must be
implemented. These additional remedial actions could include, but would not
necessarily be limited to, source treatment or removal.
10.2 Contaminated Sediment
10.2.1 Slope Erosion Protection Along the Banks of Truax Creek
An AAO for sediment at the TWCA Site includes the prevention of further release of
additional TWCA-related contaminated sediment. This element of the selected remedy
seeks to contain and prevent contaminated material in Truax Fill on the north side of
Truax Creek from being eroded and carried into Truax Creek. Geotextile covered by
riprap could be used to provide slope erosion protection. The slope erosion
protection shall extend approximately 980 lineal feet along the north bank of Truax
Creek, from where the creek enters the TWCA plant to the road crossing just west of
Pond 2 (Figure 8-3).
The PAP shall remove' vegetative cover from the slope. After removing the vegetation,
the PAP shall strip loose debris and material high in organic matter from the slope to
provide a good base for the geotextile. The PAP shall ensure that any debris or
material removed that may contain PCBs shall be handled and disposed of
appropriately. The PAP shall take preventative measures such as completion of work
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during low flow periods to ensure that PCB-contaminated material does not enter
Truax Creek during construction activities. As per EPA's Guidance on Remedial
Actions for Superfund Sites with PCB Contamination (Office of Solid Waste and
Emergency Response (OSWER) Directive No. 9355.4.01), the PRP shall ensure that all
material containing greater than 10 ppm PCBs is disposed of in accordance with all
ARARs.
After stripping any soft or loose material from the slope, the PRP shall place a
medium-to heavy-weight geotextile on the slope. The PRP shall provide that the
geotextile meets the engineering specifications required by the state of Oregon as
protected riprap.
10.2.2 Sediment Removal
This element of the selected remedy seeks to prevent migration of contamination from
sediments to surface water, reduce the levels of contaminants in sediments at the
TWCA Site and protect aquatic organisms from exposure to contaminated sediments.
The PRP shall remove approximately 3,600 cubic yards of PCB-contaminated sediment
from Murder and Truax Creeks. Areas of sediment removal .are shown in Figure 10-3.
Prior to removal, the PRP shall characterize the creeks in order to determine how to
minimize short-term and long-term impacts to the local ecosystem. The PRP shall also
characterize Conser Slough in order to determine potential effects of removal of
contaminated sediments from this deeper water body. If the Conser Slough
characterization determines that sediment removal will cause no long-term or
significant detrimental effects on the Conser Slough ecosystem, then the PRP shall
remove approximately 1,500 cubic yards of contaminated sediment from the slough.
If necessary to minimize the spreading of contaminants by flowing water during
removal, the creeks shall be diverted, and groundwater within the vicinity of th~
removal shall be contained or controlled. In order to be protective of aquatic
organisms, the cleanup level for pcas in sediments at the TWCA Site shall be 1 ppm.
This cleanup level is based upon an equilibrium partitioning approach as per EPA's
Guidance on Remedial Actions for Superfund Sites with PCB Contamination (OSWER
Directive No. 9355.4.01) using an average Site-specific total organic carbon content of
5% for the freshwater sediments found at the Site. Removed sediment shall be
sampled and analyzed to determine PCB concentrations and sediments with PCB
concentrations of 1 ppm or greater shall be disposed of off Site in accordance with all
applicable requirements.
.
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10.3 Site-Wide Actions
10.3.1 Deed Restrictions and Institutional Controls
This element of the selected remedy is designed to prevent workers on the main plant,
and potential workers in the Farm Ponds area from being exposed to contaminated
groundwater at the Site. The PRP shall implement institutional controls in the form of
deed restrictions on the construction and use of groundwater wells for drinking water
supply on the entire Site. The PRP shall implement access controls on the portions of
the Farm Ponds area that are owned by TWCA. The PRP shall implement deed
restrictions and institutional controls on the main plant and in the Farm Ponds area as
long as TWCA remains an active facility, and/or until cleanup levels are achieved.
10.3.2 Environmental Evaluation!: 01 Unlnvestigated Areas
In order to ensure that RAOs for groundwater at the Site are being achieved, the PRP
shall conduct an environmental evaluation of previously uninvestigated areas beneath
buildings and structures whenever TWCA discontinues use of, paves, or otherwise
disturbs any pond, area, or building on the TWCA Site. The PRP shall design the
scope of the environmental evaluation to determine whether there have been releases
of contamination into the groundwater beneath these structures. Potential releases of
contamination from previously un investigated areas could impede the ability of
selected remedial actions to achieve the established cleanup levels.
Examples of ponds and areas that would require an environmental evaluation include
the unlined ponds at the facility, including the Farm Ponds, ponds within the
wastewater treatment plant, and areas under buildings or pavement. excluding fences.
The PRP may design the scope of environmental evaluations so as to minimize
interference with TWCA's ongoing operations while achieving the stated purpose. EPA
in consultation with DEQ shall work with the PRP to establish sampling and analysis
protocols which do not adversely impact TWCA's ongoing operations. However. at a
minimum, the environmental evaluations shall consist of analyses of surficial soil
samples for chemical and radiologic.al contaminants. If the results of the surficial soil
sampling or other factors indicate elevated levels of chemical or radiological
contamination. the PRP would be required to conduct subsurface soil and
groundwater sampling for that currently uncharacterized portion of the Site.
Environmental evaluations of currently uncharacterized source areas shall be
scheduled for those times when TWCA makes changes in those existing buildings and
structures in order to' ensure that remediation of such sources will be integrated into
the schedule of TWCA's ongoing operations and will interfere only minimally with
TWCA's ongoing processes.
The PRP shall submit environmental evaluation reports to EPA and DEQ once every
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two years until cleanup levels are achieved. The PRP's submission of environmental
evaluation reports shall begin by September 30th of the second year after EPA
approval of the remedial design work plan and shall be due by September 30th every
other year thereafter. The PRP shall summarize in the environmental evaluation
reports any sampling analyses, conclusions, and cleanup actions of previously
uninvestigated areas throughout the Site that are conducted during each reporting
period.
EP A and DEQ will consider the information presented in the environmental evaluation
reports when evaluating remediation progress and the need for additional action.
Impacts on the selected remedy of contamination from previously un characterized
sources may be utilized by EPA and DEO in review of the effectiveness of the selected
remedy.
10.3.3
Long Term On-Site and Off-Site Groundwater, Surface Water and
Sediment Monitoring
The PRP shall implement long-term on-Site surface water, and on-Site and off-Site
groundwater monitoring, to provide an ongoing assessment of water quality and
determine the effectiveness of remedial actions. The PRP shall submit a surface water
and groundwater monitoring plan for EPA and DEO approval during remedial design.
The monitoring program described under this Section shall be distinct from the
extraction system monitoring program described in Section 10.1.1.3 of this ROD. At a
minimum, the monitoring program shall initially include monitoring of all on-Site wells
which are above cancer risk levels of 1 O~ and non cancer HI of 1. For the first year,
the monitoring program shall include quarterly sampling of groundwater monitoring
wells beneath and adjacent to the Site, plus semi-annual monitoring of on-Site and
adjacent surface water bodies. Sediments in Murder Creek, Truax Creek, and Conser
Slough shall be monitored on an annual basis for a minimum period of five years after
which time the frequency 01 sediment monitoring shall be reviewed by EP A in
consultation with DEO. Wrth respect to long-term groundwater and surface water
monitoring, after the first full year of monitoring, or anytime thereafter, EPA in
cpnsultation with DEO may determine that the frequency of monitoring may be
reduced.
The PRP shall begin the monitoring program upon implementation of the selected
remedy and shall continue the monitoring program for a minimum of 5 years after
cleanup levels are achieved.
10.3.4
CERCLA Five-Year Review
Section 121(c) of CERCLA and Section 3oo.430(f)(4)(ii) of the NCP require a review of
the remedial action no less often than once every five years if the selected remedy
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"results in hazardous substances, pollutants, or contaminants remaining on the site
above levels that allow for unlimited use and unrestricted exposure-. Statutory reviews
must continue at least every five years until contaminant levels allow for unlimited use
and unrestricted exposure.
As contaminants will remain on Site that are above risk-based levels, the selected
remedy requires that statutory reviews be conducted at least every five years. This
element of the selected remedy also recognizes that TWCA is an active facility with
ongoing operations which have impacted and limited the scope of the RifFS, and
which may continue to influence the effectiveness of remedial actions.
10.4 Costs
Estimated costs associated with the selected remedy are summarized in Table 10-3.
The extent of pretreatment of extracted groundwater will be refined during the remedial
design phase, and costs may change accordingly. The scope of environmental
evaluations may also be refined during remedial design and estimated costs may be
further adjusted.
The present worth cost estimates provided are intended to be within + 50% and -30%
of the actual costs of remediation, and are based on volume estimates established
during the FS along with the following key assumptions.
.
Groundwater extraction would be implemented at approximately 35 on-
Site wells.
.
Approximately 15 environmental evaluations beneath buildings and
structures would be conducted. Each evaluation would consist of
sampling and analyses of approximately two groundwater monitoring
wells to be drilled to a total depth of 40 feet, three subsurface sOil
borings to be drilled to a depth of 10 feet each, and five surficial soil
samples.
.
Approximately 3,600 cubic yards of sediment would be removed from the
Site.
Based on these assumptions, total capital costs for the selected remedy are estimated
to be $2.4 million. P~esent worth costs for a 30-year remedy at a 5% discount rate are
estimated to be $7.5 million.
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CAPITAL COSTS
Ground Water Extraction
(Includes extraction at Feed Makeup area)
Pretreatment of Extracted Ground Watef
$ 292,000
$
7,200
Slope Erosion Protection
Soil Flushing at Feed Makeup Area
$ 125,300
$ 3,000
$ 396,000
$ 121,000
$ 318,800
$ 16,000
$ 13,000
Sediment Removal
Institutional Controls
Environmental Evaluations
Long-TeRTt Monitoring
Offsite Monitoring
CAPITAL COSTS SUBTOTAL
$1,291,500
Contingencies @ 30%
SUBTOTAL
$ 387,500
$1,679,000
Other Costs @ 20%
(Includes Administrative, Service, Legal Costs)
SUBTOTAL
$ 335,800
$2,014,800
Design Costs @ 20%
TOTAL CAPITAL COSTS
$ 403,000
Operation and Maintenance Costs
Present Worth Costs
(Calculated for 30 years at 5% discount)
$2,417,800
$ 308,000
$7,500,000
. = Additional pretreatment costs may be Incurred" levels of groundwater which Is discharged to
TWCA's wastewater treatment plant causes an exceedance of surface water ARARs.
Estimated costs, exclusive of environmental evaluation costs, are based upon tallying costs of
individual line Items which were provided in the RifFS.
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11.0 STATUTORY DETERMINATIONS
Under CERCLA, EPA's primary responsibility is to ensure remedial actions are
undertaken which protect human health, welfare, and the environment. In addition,
Section 121 of CERCLA, 42 U.S.C. ~9621, establishes cleanup standards which
require that the selected remedial action complies with all ARARs established under
federal and state environmental law, unless such requirements are waived by EPA in
accordance with established criteria. The selected remedy must also be cost-effective
and must utilize permanent solutions, alternative treatment technologies, or resource
recovery technologies to the maximum extent practicable. Finally, CERCLA
regulations include a preference for remedies that employ treatment that permanently
and significantly reduces the volume, toxicity, or mobility of hazardous waste. The
following sections discuss how the selected remedy for the TWCA Site meets these
CERCLA requirements.
11.1
Protection 01 Human Health and the Environment
The selected remedy combines a number of containment, treatment and monitoring
measures which are designed to be protective of human health and the environment.
The selected remedy takes into account the fact that TWCA is an active facility and
that it may not be possible to completely eliminate or reduce all potential sources of
contamination without substantially interfering with TWCA's ongoing processes. The
goal of the selected remedy is to achieve protection of human health and the
environment while giving reasonable consideration to those factors.
Groundwater contamination above ARARs or risk-based levels will be contained on
Site. This measure will minimize or eliminate migration of contaminants to surface
water, and to off-Site groundwater. Some past sources of groundwater contamination
in the Solids Area have been removed during previous remedial actions.
Some remaining currently identified sources of groundwater contamination such as
subsurface feed solution in the Feed Makeup Area, will be reduced or eliminated
through a number of remedial actions. Extraction 01 groundwater above risk-based
levels will reduce the level of contaminants in groundwater. Resource recovery of
zirconium may be utilized to help reduce groundwater and subsurface soil contaminant
concentrations in the Feed Makeup area. Pretreatment of extracted groundwater prior
to surface water discharge will reduce the level of contaminants entering surface
water. Removal of contaminated sediments from the Site will be protective of aquatic
organisms by eliminC!ting potential exposure.
Prevention 01 migration of contaminants, and restoration of groundwater will be
accomplished via the source containment, treatment, removal and resource recovery
measures described above. Slope erosion protection will prevent further
contamination of Truax Creek sediments.
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Due to the ongoing operation of the TWCA facility, there may be potential
uncharacterized sources of groundwater contamination beneath existing buildings and
structures. Schedl,Jling environmental evaluations of these potential uncharacterized
source areas for those times when TWCA makes changes in those existing buildings
and structures will ensure that remediation of such sources can be integrated into the
schedule of TWCA's ongoing operations and will interfere only minimally with TWCA's
ongoing processes. This approach also takes into account the community's concerns
about the potentially disruptive effect of the selected remedy on TWCA's ability to
conduct its business.
Institutional controls and deed restrictions will further the measures described above
by controlling groundwater uses.
Additional protection will be provided by the on-Site and off-Site long-term surface
water and groundwater monitoring programs.
Implementation of the selected remedy will involve excavation of sediment, and may
result in some potential for air emissions and additional short-term risks. Short-term
risks will be minimized to the maximum extent practicable. It is expected that dust
emissions from excavation activities can be controlled to acceptable levels through the
use of dust suppressants. Potential migration of contaminants in sediments to surface
water during the excavation of contaminated sediments will be controlled and
contained via groundwater containment and surface water diversion. No adverse
cross-media impacts are anticipated.
11.2 Compliance with Applicable or Relevant and Appropriate Requirements
(ARARs)
The selected remedy will comply with all ARARs that have been identified. No waiver
of any ARAR is being sought or invoked for any component of the selected remedy.
The ARARs identified for the TWCA Site include the following: -
Chemical-Specific ARARs
Chemical-specific requirements are usually health- or risk-based numerical values or
methodologies that establish the acceptable amount or concentration of a chemical in
the ambient environment. Following are the chemical-specific requirements for the
TWCA Site:
1.
SDWA MCLs and non-zero MCLGs, 40 C.F.R. Part 141.
Applicable for off-property-drinking water supplies, if these wells are
community wells that serve more than two residences. Relevant and
appropriate for on-Site and off-Site groundwater.
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2.
Oregon Environmental Cleanup Law, ORS 465.315; Oregon
Environmental Cleanup Rules, Standards, OAR 340-122-Q40.
These regulations are applicable for on-Site groundwater and sediments. .
3.
Oregon Water Quality Criteria for the Willamette Basin, OAR 340-41-445.
These regulations are applicable to extracted groundwater which is
discharged to surface water. Relevant and appropriate for
groundwater which discharges directly to surface water as a non-point
source.
4.
Oregon Ground Water Quality Statute, ORS 468B.150 to 185.
This statute is relevant and appropriate for remediation of groundwater
at the Site.
Location-Specific ARARs
Location-specific requirements are restrictions based on the concentration of
hazardous substances or the conduct of activities in specific locations. These may
restrict or preclude certain remedial actions or may apply only to certain portions of
the Site.
1.
Executive Order 11988, Statement of Procedures on Floodplain
Management and Wetlands Protection, Appendix A to 40 C.F.R. Part 6.
The selected remedy is not expected to have an impact on wetlands at
the Site. However, this requirement is relevant and appropriate to
remedial actions which may affect on-Site surface water such as Truax
and Murder Creeks. r . -
2.
Oregon's statewide planning goals, Goal 5 (Open Spaces, Scenic and
Historic Areas, and Natural Resources), Goal 6 (Air, Water and Land
Resources Quality), Goal 7 (Areas Subject to Natural Disaster and
Hazards) and Goal 15 (Willamette River Greenway).
These regulations are applicable for those portions of the TWCA Site
that lie within the Willamette River floodplain. The City of Millersburg is
the local jurisdiction responsible for ensuring the objectives of these
goals are satisfied. Remedial actions planned for these areas will need
to be cleared through the City of Millersburg under its floodplain
ordinance.
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3.
The Oregon Removal-Fill Law, ORS 196.800-196.990.
This regulation is relevant and appropriate for those removal and
remedial actions at the TWCA Site associated with removal of Truax Fill
material and sediment remediation. The Oregon Removal-Fill Law
requires a permit from the Oregon Division of State Lands if 50 or more
cubic yards of material is removed or filled in wetlands, streams, ponds
and other areas. Although Section 121 (e)(1) of CERCLA specifies that
permits are not required for remedial actions conducted on site, the
substantive requirements of the Oregon Removal-Fill law will be
complied with.
4.
CWA, Section 404(b)(1) Guidelines for Specification of Disposal Sites for
Dredged or Fill Material, 40 C.F.R. Part 230; and Section 404(C)
Procedures, 40 C.F.R. Part 231.
These regulations are applicable as wetlands and other water bodies
located on, or in the vicinity of the TWCA Site could be affected by
sediment remediation activities.
5.
Fish and Wildlife Coordination Act (16 U.S.C. Part 661 et sea.) 40 C.F.R.
Part 6.302 and 50 C.F:R. Part 83.
This regulation is applicable because surface water bodies on and
adjacent to the TWCA Site could be affected by remediation activities.
Action-Specific ARARs
Action-specific ARARs are technology- or activity based controls or restrictions on
activities related to management of hazardous wastes. These requirements are
triggered by the particular remedial activities selected to cleanup the Site. -
1.
TSCA PCB Disposal regulations, 40 C.F.R. ~ 761.60; Oregon Hazardous
Waste Management Rules for PCBs, OAR 340-110.
These regulations may be applicable for PCB-contaminated materials
that are disposed off-Site.
2.
RCRA l,and Disposal Treatment Standards, 40 C.F.R. Part 268, Subpart
D; RCRA Transportation regulations, 40 C.F.R. Part 263.
Excavated sediment and debris will be analyzed to determine whether or
not they exhibit RCRA hazardous waste characteristics. If the sediment
or debris are RCRA hazardous waste then the above ARARs may be
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applicable.
3.
Oregon Hazardous Waste Management Rules, OAR 340-100; Oregon
Standards Applicable t~ Generators of Hazardous Waste, OAR 340-102;
Identification and Usting of Hazardous Wastes, OAR 340-101.
These regulations may be applicable for the off-Site disposal and on-Site
management of hazardous wastes.
4.
Oregon Standards for Owners and Operators of Hazardous Waste
Treatment Storage and Disposal Facilities.
This regulation is relevant and appropriate for groundwater
pretreatment, and decontamination of waste residuals.
5.
CWA NPDES Industrial and/or Stormwater Discharge Permits
regulations, 40 C.F.R. 122; Ambient Water Quality Criteria, 40 C.F.R. Part
131; Oregon Regulations Pertaining to NPDES Permits, OAR 340-45
These regulations are applicable for groundwater pretreatment systems
which will be designed to meet these requirements. Treated
groundwater will be discharged in a manner which complies with the
substantive requirements of the above-mentioned ARARs, or in
compliance with TWCA's NPDES permit, whichever is more stringent.
6.
CM National Primary and Secondary Ambient Air Quality Standards, 40
C.F.R. Part 50; CM National Emissions Standards for Hazardous Air
Pollutants, 40 C.F.R. Part 60; CM New Source Performance Standards,
40 C.F.R. Part 61. RCRA Air Emission Standards for Process Vents, 40
C.F.R. Part 264, Subpart M.
The CM regulations are applicable for on-Site air emissions from
groundwater treatment systems and for control of dust particles emitted
into the air during remediation construction activities. The RCRA
regulations are relevant and appropriate for on-Site air emissions from
groundwater treatment systems.
7.
Occupational Safety and Health Act (OSHA), 29 U.S.C. 651; the
implementing regulations under OSHA, 20 C.F.R. Parts 1910 and 1926.
Oregon Occupational Safety and Health Code (OROSHA), OAR Chapter
860.
These regulations are applicable for all construction activities related to
the selected remedy.
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8.
Amendment to NCP, Procedures for Planning and Implementing Off-Site
Response Actions, 40 C.F.R. ~300.440.
These rules and requirements are applicable to off-Site management of
CERCLA hazardous substances, pollutants or contaminants resulting
from this ROD.
9.
RCRA, Closure and Post-Closure regulations, 40 C.F.R. Part 264,
SubpartG.
These regulations are applicable for those on-Site areas which may be
identified under RCRA authority as Regulated Units. The regulations are
relevant and appropriate for the former on-Site sludge ponds, such as
the LRSP and Schmidt Lake.
Polley, Guidance and Regulations To-Be-Consldered
.
Additional policies, guidance and other laws and regulations to be
considered for source control and remedial actions include, but are not
necessarily limited to the SDWA Secondary MCLs, 40 C.F.R. 143; the
TSCA PCB Spill Cleanup Policy, 40 C.F.R. 761.120; the EPA Guidance
on Selecting Remedies at Superfund sites with PCB Contamination
(OSWER Directive No. 9355.4-01); RCRA Corrective Action Management
Units and Temporary Units; Corrective Action Provisions, 40 C.F.R.
~264.552;DEQ's Draft Examples of Concentrations Meeting Criteria for
Action Levels, (Section 264.521 (a)(2W-iv)); DEQ's Air Quality Division's
Toxic Air Pollutant Program Significant Emission Rates.
The SDWA Secondary MCLs regulate the maximum permissible level of a
contaminant in water which is delivered to the free flowing outlet of the
ultimate user of a public water system. The Secondary MCLs may be
considered for on-Site groundwater which may migrate off Site, or which
may be discharged off Site via pretreatment and/or TWCA's existing
treatment system.
The TSCA PCB Spill Cleanup Policy provides guidance on recommended
cleanup levels under certain access scenarios. The Superfund PCB
Guidance recommends cleanup criteria for remediation of PCB-
contam,inated media. The guidance also recommends cap designs
which are consistent with RCRA guidance, and specifies long-term
management controls for PCB-contaminated media.
DEQ's Air Quality Division's Toxic Air Pollutant Program Significant
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Emission Rates are used as a rough screening tool to determine if air
emissions from a facility are Toxic Air Pollutants, and if the quantity is
significant to cause a potential. harmful health effect. Air emissions
resulting from Superfund remediation activities at the TWCA Site will be
monitored to ensure that levels of air emissions are not of concern.
11.3 Cost Effectiveness
EP A has determined that the combination of remedial actions identified as the selected
remedy will reduce or eliminate the risks to human health and the environment in a
cost -effective manner. Groundwater extraction and treatment costs at the Site will be
minimized. Groundwater extraction will be mostly from existing monitoring wells.
Treatment and surface water discharge of extracted groundwater will be via TWCA's
existing wastewater treatment plant. Equipment and technologies to be used for
source remediation activities are readily available and proven to be effective.
Costs of additional pretreatment prior to discharge to TWCA's wastewater treatment
plant cannot be accurately calculated at this time, because it is unknown what volume
of groundwater will need to be pretreated. Pretreatment of extracted groundwater may
be required in order to meet the requirements of the CWA. Additional costs may be
incurred through the implementation of cleanup actions which would be a result of the
environmental evaluations of previously uninvestigated areas. Environmental
evaluations, however add a vital level of protectiveness to the selected remedy.
The selected remedy recognizes that TWCA is an active facility with ongoing
operations and seeks to achieve protectiveness with minimal impact on those
operations. By tailoring the remedy so that removal and any necessary treatment and
resource recovery are applied to some of the major source areas, and containment is
used for contaminated groundwater, the selected remedy provides an appropriate
level of protection for the Site and for potential off-site receptors.
11.4 Utilization of Permanent Solutions and Resource Recovery Technologies
to the Maximum Extent Practicable
EPA and DEO have determined that the selected remedy represents the maximum
extent to which permanent solutions and treatment technologies can be utilized in a
cost-effective manner for the groundwater and sediment operable unit at the TWCA
Site. Of those alternatives that are protective of human health and the environment
and comply with A~Rs, EPA and DEO have determined that this selected remedy
provides the best balance of trade-offs in terms of long-term effectiveness,
implementability, and cost, while also considering the statutory preference for
treatment as a principal element and considering state and community acceptance.
The selected remedy recognizes that TWCA is an active facility with ongoing
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operations that may impact the effectiveness and permanence of remedial actions.
Scheduling environmental evaluations of previously uninvestigated areas at times when
TWCA is making changes in those buildings and structures during the normal course
01 business will serve two purposes (1) it will increase the degree 01 permanence of
remedial actions called for in this ROO, by ensuring that releases from these
uninvestigated areas do not impede achievement of cleanup goals: and (2) it will do so
with minimal impact on TWCA's ongoing operations. That approach will also help to
address community concerns about TWCA's ability to continue its business
operations.
Resource recovery of contaminants in groundwater and subsurface feed solution in
the Feed Makeup area of the main plant would allow reuse of zirconium. Removal of
contaminated sediments will permanently reduce and potentially eliminate aquatic
organism exposure to contaminants.
The selected remedy employs a combination of treatment and containment of
groundwater in a cost-effective manner to reduce contaminant volume, mobility, and
toxicity .
11.5 Preference for Treatment as a Principal Element
Pretreatment if necessary, and treatment of groundwater via TWCA's existing
wastewater treatment plant will satisfy the CERCLA preference for treatment of
principal threats. The selected remedy incorporates a number of resource recovery
and treatment elements which are designed to reduce or eliminate major currently
identified sources of groundwater contamination at the TWCA Site.
11.6 Community Acceptance
Verbal comments received at the Proposed Plan public meeting held on September
14, 1993, in Albany, Oregon, and written comments submitted to EPA during the
public comment period on the Proposed Plan, indicate that the community is
concerned about the potential for the preferred alternative to interfere with TWCA's
ability to maintain a viable ongoing operation. In addition, the community was
concerned that TWCA not be required to actively clean up the groundwater to what
many people considered to be an unrealistically stringent drinking water standard.
The community's comments and suggestions, as well as EPA responses, can be
found in the Responsiveness Summary section of this ROO.
EP A has determined that the selected remedy takes into consideration the concerns of
the community in that remedial actions will be designed so as to have minimal impact
on TWCA's ongoing operations. Environmental evaluations of previously
uninvestigated areas are designed to be conducted whenever TWCA itself determines
that these areas are accessible to be investigated. For example, such environmental
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evaluations would occur when TWCA itself decides to raze a building or to make
substantial structural changes that would in themselves be disrupting TWCA's
operations in that area.
Remediation of surface and subsurface soil contamination has been deferred to a
subsequent operable unit so that additional information regarding radiological
contamination can be obtained and community concerns can be further addressed.
Requirements for source reduction measures have been eliminated from the selected
remedy as EPA anticipates that TWCA will implement these measures voluntarily.
Contaminated groundwater beneath the Site will be managed so that contaminants
above drinking-water standards do not migrate off-Site. However, all on-Site
groundwater wells which are above drinking water standards will not require extraction
and treatment to below drinking water standards because EPA expects that reduction
and/or elimination of groundwater contaminant source areas, combined with natural
attenuation, will enable groundwater beneath the entire Site to achieve the required
cleanup levels.
11.7 Conclusions
The selected remedy achieves the best balance among the nine evaluation criteria.
The selected remedy utilizes permanent solutions and treatment technologies to the
maximum extent practicable while providing the best balance among the other
evaluation criteria. It achieves the best balance of tradeoffs with respect to the primary
balancing criteria of long-term effectiveness and permanence; reduction in toxicity,
mobility, and volume through treatment; short term effectiveness; implementability; and
cost. Additional considerations included the statutory preference for treatment as a
principal element, and acceptability to the State and the potentially affected
community.
TWCA has communicated to EPA both verbally and in written comments that TWCA
believes EPA should select Alternative 3, proposed by TWCA, as the remediar
alternative. However, EPA has determined that Alternative 3 would not effectively
address the majority of the identified contaminant sources on Site. These identified
sources include, but may not be limited to; the Ammonium Sulfate Storage Area, the
Powder Metallurgy Building Area, the Emergency Services Building Area, the Acid
Sump area, the Arc-Melting Area, and the Soil Amendment Area. In addition,
groundwater contaminants would not be contained on Site, and would continue to
migrate to surface water and under adjacent property. Contaminated sediments would
remain on Site and would continue to pose a threat to aquatic life.
The selected remedy, Alternative 7, provides a high degree of long-term effectiveness
and permanence through the requirement for extraction and pretreatment of
contaminated groundwater, resource recovery of contaminated feed makeup solution,
and removal of contaminated sediments. In addition, the selected remedy is the only
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remedial alternative which will ensure the long-term effectiveness of remedial actions
through the requirement for environmental evaluations of previously uninvestigated
areas. Uninvestigated areas could potentially interfere with the ability of the remedial
action to attain cleanup levels.
Alternative 7, the selected remedy, is the only remedial alternative which will address
all ARARs through the requirement for pretreatment of contaminated groundwater prior
to discharge to surface water. The selected remedy provides significant reduction in
toxicity, mobility I and volume by reduction of volume through pretreatment of on-Site
contaminants in groundwater, and through resource recovery of zirconium in the Feed
Makeup area.
The selected remedy is a logical outgrowth of community concerns and is designed so
as not to adversely impact TWCA's ongoing operations.
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12.0 DOCUMENTATION OF SIGNIFICANT DIFFERENCES
In response to public comment on the Proposed Plan, EPA re-evaluated the
groundwater extraction remedial element, clarified the need for pretreatment of
groundwater, provided more detail for the environmental evaluations which may be
conducted at previously uninvestigated areas of the Site, and deferred remediation of
surface and subsurface soil to a subsequent operable unit. In addition, in response to
concerns raised by TWCA during the public comment period, EP A re-evaluated and
eliminated the source reduction element of the Proposed Plan.
Some of the changes are significant changes. However, all these changes are logical
outgrowths of the information available to the public in the Proposed Plan and the
RI/FS reports. Additional public notice or public comment period was determined not
to be necessary because, based on the information available during the public
comment period and based on the comments submitted, the public could have
reasonably anticipated the changes described.
The following sections discuss in more detail the changes that have been incorporated
in the selected remedy.
12.1
Groundwater Extraction
The Proposed Plan included extraction at 36 groundwater monitoring wells that were
determined by the RI/FS to have calculated RME lifetime cancer risk values equal to
or exceeding 10.0, and non-cancer hazard index (HI) values exceeding 1, and/or at
least one average chemical concentration exceeding MCLs or non-zero MCLGs. In
response to TWCA and community concerns that TWCA not be required to actively
clean up the groundwater to what many people considered to be an unrealistic
drinking water standard for an active operating facility, the selected remedy requires
groundwater extraction only at identified hot spots and source areas of the Site that
exceed the lifetime cancer risk level of 10-4 and/or substantially exceed the noncancer
H I of 1. Extraction shall occur until those hot spots and source areas achieve cleanup
levels.
In order to ensure that this element of the selected remedy is protective of human
health and the environment, and in order to achieve the established RAOs and
cleanup levels established for groundwater at the TWCA Site, the following remedial
measures have been added:
1) Active groundwater remediation (extraction) on the Site shall be applied to
areas that have been identified as sources or hot spots. Groundwater
extraction will occur until cleanup tevels are achieved. Groundwater extraction
is expected to occur for an estimated period of 15 years. For those on-Site
areas in which groundwater contamination is above cleanup levels but active
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groundwater remediation (Le. extraction) is not required, natural attenuation
may be relied upon to aid reduction of the chemical concentrations in these
areas to cleanup levels.
2) If any groundwater above cleanup levels is detected in Site perimeter
monitoring wells at any time, actions shall be taken to ensure that the
contaminated groundwater does not migrate off-Site or into adjoining surface
water bodies.
It is expected that groundwater extraction of the areas of higher risk levels will reduce
sources of contamination to other areas and will expedite the timeframe required for
the attainment of cleanup levels by natural attenuation. In addition, groundwater
extraction will ensure that groundwater contamination which is above drinking water
standards will be contained on-Site until cleanup levels are achieved.
In order to ensure that groundwater extraction is effective in removing and containing
on-Site contaminants, the groundwater extraction system shall be carefully monitored
until cleanup levels are achieved.
12.1.1 Determination of Achievablllty of Cleanup Levels
The Proposed Plan did not explain the possible contingency measures which may be
implemented in order to assure achievement of groundwater cleanup goals. The
determination as to whether Site-wide groundwater cleanup levels are achievable
within the projected 15-year timeframe will be made by EPA, in consultation with DEC.
The following contingency measures may be implemented in order to ensure
achievement of groundwater cleanup goals:
Three years after commencing operation of the extraction system an historical and
statistical analysis of Site-wide groundwater contaminant concentrations will be
conducted to determine if cleanup levels are likely to decline within 15 years after start
up of the extraction system. If this analysis indicates that contaminant concentrations
in groundwater beneath the Site are not likely to decline to cleanup levels within 15
years after commencement of operation of the extraction system, the existing
extraction system may be modified in any or all of the following ways:
a) at individual wells where cleanup levels have been attained, pumping may
be discontinu~d;
b) alternating pumping may be instituted at wells to eliminate stagnation points,
c) pulse pumping may be instituted to allow aquifer equilibration and to allow
adsorbed contaminants to partition into groundwater;
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d) installation of additional extraction wells may be instituted to facilitate or
accelerate cleanup of the contaminant plume. The installation of additional
extraction wells shall not necessarily be limited to areas with cancer risk levels
exceeding 10"', if performance reviews indicate pumping in lower-risk areas
would assist groundwater cleanup and help achieve groundwater RAOs.
e) Additional extraction measures may be conducted in source areas or "hot
spots" which are delineated as a result of environmental evaluations or as a
result of any other additional sampling which is required by the selected
remedy.
In addition, if it is determined on the basis of the system performance data that certain
portions of the affected groundwater areas cannot be restored to cleanup levels, some
or all of the following measures involving long-term management may be implemented,
for an indefinite period of time, as a modification of the existing system:
a) engineering controls such as physical barriers, or long-term gradient control
provided by low level pumping, as containment measures;
b) institutional controls will be maintained so as to restrict access to portions of
the affected groundwater which remain above cleanup levels.
c) continued monitoring of specified wells;
d) periodic reevaluation of remedial technologies for groundwater restoration.
12.2 Pretreatment of Groundwater
The Proposed Plan did not clarify the conditions under which TWCA would be required
to pretreat extracted groundwater. As TWCA's existing NPDES permit was designed
to address certain contaminants it is possible that implementation of this selected
remedy will result in discharge of contamination which was not addressed by the
NPDES permit. The selected remedy does not incorporate a mandatory requirement
for pretreatment of extracted groundwater. However, in order to ensure that the
discharge of extracted groundwater to TWCA's existing wastewater treatment plant will
meet ARARs prior to discharge, an evaluation of the BPT which can be used to
pretreat the extracted groundwater will be conducted during remedial design. Upon
completion of this evaluation, EPA, in consultation with DEO, will select the BPT which
will then be implemented to pretreat contaminated groundwater prior to discharge to
TWCA's wastewater treatment facility.
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12.3 Deferral of Surface and Subsurface Soli Remediation to a Subsequent
Operable Unit ROD
The TWCA RI/FS contained several data gaps with respect to delineation of the nature
and extent of soil contamination and evaluation of soil remediation options at the Site.
These data gaps include:
.
The RI/FS did not include a detailed evaluation of soil remediation
options in the main plant portion of the Site, with the exception of the
Feed Makeup Area.
.
Confirmatory sampling of surface and subsurface soils in the Solids Area
was not conducted as part of the RI/FS.
.
Remedial options for the Soil Amendment area were not fully identified in
the RI/FS.
.
While a Radiological Survey was submitted as an addendum to the
RI/FS, the Radiological Survey did not adequately characterize risks due
to exposure to radiation in soils at the Site.
Because of the necessity to address these data gaps in the RI/FS, along with the
need to evaluate Site-wide soil remediation options in accordance with the
requirements of the Oregon Environmental Cleanup Rules (OAR 340-122-090) the
RI/FS will be amended subsequent to this ROD. The amended RI/FS will include an
evaluation of soil cleanup options.
"
Contingent removal and/or treatment of surface soil is an element of the remedial
action alternative which was identified in the Proposed Plan. This cleanup option is
not included in this ROD as part of the detailed analysis of alternatives, but will be
reevaluated as part of the subsequent soils operable unit. -
Upon completion of the evaluation and reevaluation of all soil cleanup options, and
after a public comment period, EPA in consultation with DEa, will document the
selected soil cleanup remedy in a subsequent ROD.
12.4 Environmental Evaluations of Previously Uninvestigated Areas
The Proposed Plan did not clarify the scope or purpose of the environmental
evaluations which are to be conducted at previously uninvestigated areas. This
element of the selected remedy recognizes that TWCA is an active operating facility.
As the scope of the RI/FS was designed-so as not to interfere with ongoing
operations at the TWCA facility, areas beneath active ponds, buildings and structures
at the facility were not sampled. Sampling such areas as part of the RI/FS would have
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up paved areas, install groundwater monitoring wells in the buildings, and sample
beneath active waste ponds. Because the RifFS was designed so as not require
TWCA to engage in such disruption of its business operations, it is possible that some
areas of potential contamination beneath existing buildings and structures may not
have been fully addressed by the sampling efforts.
Ongoing releases of contamination, if any, from portions of the Site that are currently
uncharacterized could negatively impact the effectiveness of remedial actions for
groundwater at the Site. In addition, those potential contaminant source areas could
pose an added threat to human health and the environment. The purpose of
environmental evaluations of those previously uninvestigated areas during the remedial
design/remedial action stage is to ensure that any data gaps can be addressed at a
later date so that the Superfund remedial actions called for by this ROD will be
effective.
12.5 Elimination of Source Reduction
Evaluation and implementation of source reduction techniques to minimize current and
potential Mure releases from ongoing plant operations was an element of the
Proposed Plan. This element has been eliminated from the selected remedy in .
response to concerns raised by TWCA during the public comment period that a
requirement to impose source reduction measures could directly interfere with its
ongoing processes. In determining that this element can be eliminated at this time,
EPA recognizes that, because TWCA is an operating facility and hazardous waste
generator, source reduction is addressed at the TWCA facility in part through other
statutes such as RCRA, TSCA, and the CWA. In addition, Section 103(a) and (b) of
CERCLA and Section 304 of the Emergency Planning and Community Right-To-Know
Act of 1986 (EPCRA) also impose requirements for reporting releases of hazardous
substances to appropriate regulatory agencies.
EPA and DEO also expect that TWCA will voluntarily and responsibly work to reduce
or eliminate all potential sources of contamination in order to prevent further
contamination and to help ensure the effectiveness of remedial actions at the Site.
However, should the effectiveness of the selected remedy be adversely affected
because of continuing spills and leaks of hazardous substances from the TWCA facility
to the environment, EPA may require that TWCA implement source reduction
measures in the future.
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ApPENDIX A
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Section 1
Introduction
A.
Overview:
The purpose of this responsiveness summary is to summarize and respond to
public comments submitted regarding the Proposed Plan for the cleanup of the
Teledyne Wah Chang Albany (TWCA) Superfund Site. The public comment period for
the Proposed Plan was initially held from August 27 to September 27, 1993. At the
request of TWCA, the public comment period was extended to October 27, 1993. This
responsiveness summary meets the requirements of Section 117 of the
Comprehensive Environmental Response, Compensation, and Uability Act of 1980
(CERCLA) as amended by the Superfund Amendments and Reauthorization Act of
1986 (SARA).
In the Proposed Plan, issued August 25, 1993, the U.S. Environmental
Protection Agency (EPA) described alternatives considered for the cleanup of soils,
sediment, and groundwater at the TWCA Site. These cleanup alternatives were based
on information collected during a Remedial Investigation and Feasibility Study (RifFS)
conducted on the Site. The purpose of an RifFS is to conduct a thorough study of
the Site and to assess possible plans to clean up the Site. The RifFS and Proposed
Plan were available at the Albany Public Ubrary, and copies of the Proposed Plan were
mailed to a list of local citizens developed as part of the Community Relations Plan.
EPA held a public meeting on September 14, 1993 at the Unn-Benton
Community College in Albany to present the results of the RifFS and to outline EPA's
proposed cleanup plan. The meeting was attended by over one hundred fifty people
which included representatives of TWCA. A number of questions were asked by
attendees at the public meeting who expressed some opposition to the proposed
cleanup plan. Questions that were asked and answered at the pUblic meeting are
recorded in the meeting transcript which is available in the Administrative Record for
the Site at the Albany Public Ubrary. Those questions are not included in this
document. The majority of the commenters at the public meeting expressed concern
that the Proposed Plan would present a financial hardship to TWCA which could then
have a detrimental impact on the economic welfare of the community.
Eighty three comment letters were received from citizens during the public
comment period. Twenty two commenters presented oral comments at the
September 14, 1993 pUblic meeting. Ten percent of the comment letters supported
the Proposed Plan. The Oregon Department of Environmental Quality (ODEQ)
supported the Proposed Plan. Ninety percent of the comment letters expressed some
opposition to, or concern about the Proposed Plan. Many of these concerns appear
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to be in response to a "white paper" opposing the cleanup plan distributed by TWCA
to the Oregon business community during the public comment period.
TWCA submitted written comments opposing the Proposed Plan on October 5,
1993, and again on October 27, 1993. In addition, EPA met in person with
representatives of TWCA on October 15, 1993. The minutes and comments from the
October 15, 1993 meeting were transcribed and are available in the Administrative
Record.
Generally, TWCA and those citizens who opposed the Proposed Plan had the
following concerns which were initially defined in the TWCA "white paper":
6.)
1.)
The Proposed Plan hinder's TWCA's ability to adapt competitively, and
contains too many "blank checks. which could present a financial
hardship to TWCA and the community.
2.)
The Proposed Plan duplicates regulatory systems which are already in
place at TWCA.
3.)
The Proposed Plan appears to abandon a good faith agreement which
TWCA had with EPA regarding the RifFS. EPA and TWCA together
signed an Administrative Order on Consent in 1987 which required
TWCA to conduct the RifFS. EPA appears to want to ignore the
company's past track record of years of cooperation.
4.)
The Proposed Plan creates too negative a picture of the impact of the
groundwater and soil contamination problems at the Site because
components of the Proposed Plan are based on the assumption that
people will be drinking contaminated groundwater, and that workers
would be ingesting contaminated soil at the Site.
5.)
The Proposed Plan does not consider all of EPA's nine evaluation criteria
for choosing a cleanup alternative because it does not appear to fully
evaluate cost effectiveness.
EPA did not provide TWCA due process in presenting EPA's cleanup
plan for the Site because TWCA was not given the opportunity during the
RifFS to analyze the Proposed Plan as such.
Subsequent to' issuance of the Proposed Plan and conclusion of the public
comment period, TWCA submitted an addendum to the RI/FS which included an
evaluation of radiological risk in soil at the Site. EPA has determined that this
addendum to the RifFS does not adequately characterize risks due to exposure to
radiation in soils at the Site. In addition, the TWCA RI/FS contained several data gaps
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with respect to the evaluation of soil cleanup options. Therefore, the selection of
cleanup options for contaminated soil at the TWCA Site has been deferred to a
subsequent operable unit ROD.
B.
Scope 01 Response to Comments:
The primary aim of this Responsiveness Summary is to address specific
comments on the Proposed Plan.
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Section 2
Community Involvement
A.
Background
The TWCA Site is located in Millersburg, Oregon, approximately one mile north
of the city of Albany. The facility covers approximately 225 acres adjacent to the
Willamette River.
TWCA is an active operating facility which primarily manufactures zirconium
metal. The manufacturing operation consists of numerous production facilities used
for the extraction and refining of zirconium and hafnium metals from zircon sands, with
a small amount of tantalum, columbium, titanium and vanadium metals also being
produced. The plant also has a number of waste treatment and storage facilities and
several on-site ponds that were, or presently are, being used for the storage of liquid
and solid wastes.
The processing of the zircon sands generates various waste materials such as
sludge, waste water, residues and gases. Past practices at the TWCA facility have led
to improper disposal and management of some of these waste materials. Some
examples of improper disposal and management include the storage of sludges in
unlined ponds, and leaks and spills of hazardous substances which are 'used in
TWCA's manufacturing processes. Contaminants of concern at the Site include
radionuclides, metals, polychlorinated biphenyls (PCBs), methyl isobutyl ketone
(MIBK), and chlorinated organic solvents such as 1,1, 1-trichloroethane, carbon
tetrachloride, and tetrachloroethylene.
The area surrounding the Site is primarily zoned for industrial purposes. The
facility is bounded on the east by Old Salem Road and Interstate 5. The land east and
south of the facility is used mainly for residential and commercial purposes. The
Willamette River borders the facility to the west. Portions of the TWCA facility are
within the Willamette River's 100-year and 5OD-year flood plains. The land west of the
Willamette River is used for farming. Willamette Industries' particle board plant borders
the TWCA main plant to the northeast Land to the north of the TWCA facility is used
for a combination of agricultural and industrial purposes.
Albany, the urban area south of the TWCA facility, had a population of
approximately 29,000 people in 1990. Millersburg had a population of about 700
people. TWCA employs approximately 1,150 people from the area.
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B.
Community Concerns
In preparation for development of a community relations plan, EPA met with
community leaders, private citizens, elected officials, local media, and TWCA
representatives to hear their concerns about the Site. The Community Relations Plan
was published in November 1987 and revised in October 1991. As a result of the
meetings with community representatives a list of community concerns was developed
prior to, and during implementation of the RifFS. Following is a list of these concerns
and a brief description of EPA responses to them:
1)
What is the purpose and scope of the Superfund process at the TWCA
facility?
The Superfund process at TWCA is divided into three phases. The first
phase is the study phase to determine the nature and extent of
contamination in groundwater, surface water, soil, sediment, and air from
releases of hazardous substances, pollutants and contaminants into the
environment due to operations and waste disposal practices at the
TWCA facility. TWCA has completed this first study phase. Once the
nature and extent of contamination are known, cleanup actions are
proposed and decided upon. This decision phase is the phase which is
being documented by the Record of Decision and this Responsiveness
Summary. Once the cleanup actions are decided upon they are
designed and implemented during the final cleanup phase. Cleanup
actions will be implemented for contamination in groundwater, surface
water, soil, or air at the TWCA Site which may pose an imminent and
substantial danger to pubic health or welfare.
2)
. Are the Superfund actions being proposed and taken at the TWCA Site
really necessary?
The TWCA facility has been in operation for over thirty five years. Past
operation and waste disposal practices have resulted in leaks, spills, and
improper disposal of solvents, metals and other hazardous materials
throughout the facility. Soil, sediment, and groundwater at the facility are
contaminated with volatile organic compounds, metals, and
radionuclides. The Superfund actions are designed to clean up
contamination that has resulted from past practices. The Superfund
actions also recognize that TWCA is an active operating facility and
elements of the selected cleanup remedy are designed to provide a
measure of insurance that the cleanup actions will be effective in the long
term.
3)
What will be the impact of the cost of a Superfund cleanup on TWCA?
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The estimated capital costs of implementing the Superfund cleanup
remedy for groundwater and sediment at the Site ($2.4 million) are
significantly less than the costs which have been estimated for the RljFS
($5 million) which has already been completed. One reason for this is
that existing equipment will be utilized for the cleanup. For instance;
existing monitoring wells will be converted to groundwater extraction
wells. Utilization of existing equipment will defray capital costs.
Utilization of TWCA's existing wastewater treatment facility for treatment
of extracted groundwater will also minimize both capital cost and long-
term operation and maintenance costs.
4)
Is there a potential for negative impact on the Willamette River from
contamination associated with the TWCA facility?
The TWCA RifFS concluded that contaminated groundwater from the
TWCA Site either discharges to on-Site surface water bodies which flow
to the Willamette River, or directly to the river. The impact on the river
due to migration of contamination from the TWCA Site was not evaluated
in the TWCA RljFS. However, EPA's preferred alternative and the
selected remedy include measures that are designed to ensure that
contamination does not migrate off of the TWCA Site.
5)
Are there possible health threats to workers at the TWCA plant?
The TWCA RljFS concluded that workers on the TWCA facility may be
exposed to chemicals in surface and subsurface soil through incidental
ingestion or external exposure. The primary chemicals in soil that
contribute to health risk are PCBs and radionuclides. The RljFS also
concluded that should workers ingest contaminated groundwater, they
would be exposed to health risks from metals, chlorinated organic
compounds, and other organic compounds such as methyl-isobutyl-
ketone (MIBK).
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Section 3
Response to Comments Received From the Public at Large
During the Public Comment Period
This section summarizes and responds to comments received from the general
public during the public comment period on EPA's Proposed Plan. Comments and
responses in this section are arranged by topic. Those which applied to more than
one topic were responded to under the heading considered the most appropriate.
Paraphrasing was used to incorporate related concerns expressed in more than one
comment. Every attempt has been made to respond to concerns raised during the
comment period.
Many of the comments "received were what EPA interpreted as public reaction
to a .White Paper" issued by TWCA. The .White Paper- (so designated by TWCA)
was prepared and distributed by TWCA to the community but not to EPA. TWCA's
White Paper took issue with the Proposed Plan and expressed TWCA's concerns that
the Proposed Plan: (1) could present a financial hardship to TWCA and the
community; (2) might duplicate regulatory systems which are already in place at
TWCA; (3) appears to vary from the terms of a 1987 Administrative Order on Consent
(AOC, termed .good faith agreement. by TWCA) between EPA and TWCA, providing
for TWCA to conduct the RifFS under EPA oversight; (4) creates too negative a
picture of the groundwater and soil contamination problems at the Site; (5) does not
appear to adequately consider cost effectiveness; and (6) denies TWCA due process
in the selection of a cleanup remedy for the Site because TWCA could not analyze the
Proposed Plan in the RifFS. Because many of the public comments were directed to
issues as they were expressed by TWCA in the White Paper rather than directed to
issues as expressed in EPA's Proposed Plan, in this response to comments, EPA has
included a category to incorporate issues expressed by the .White Paper."
Comments below are grouped in the following categories:
1 to 7
8
9 to 12
13 to 16
17 to 26
.White Paper"
Due Process
Risk Assessment and Risk Related Issues
RifFS Issues
Miscellaneous
'White Paper"
1)
COMMENT: Several commenters suggested that EPA's proposals are
unreasonable and unjustified under the circumstances posed by the fact that
TWCA is an operating facility. The commenters stated that based on the public
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meeting at Unn-Benton Community College (LBCC), EPA had proposed a
specific set of criteria that is beyond the legal requirements necessary for this
site. These criteria included the proposals for source reduction measures and
environmental evaluations of previously uninvestigated areas. It was also
suggested that EPA did not fully evaluate the nine evaluation criteria for
selecting a remedial alternative. Cost effectiveness was mentioned as an
example of one of the evaluation criteria which some commenters believed were
not fully analyzed by EPA.
RESPONSE: All the cleanup alternatives analyzed by EPA in the Proposed
Plan were evaluated according to nine criteria which are required by the
Superfund regulations. The evaluation according to the nine criteria is set out in
the Proposed Plan and in the ROD. Among those nine criteria are three that
include; (1) protectiveness of human health and the environment, (2) long-term
effectiveness, and, (3) cost-effectiveness. One of the factors influencing EPA's
cost-effectiveness considerations was the fact that TWCA is an active facility
with several complex ongoing manufacturing processes. In consideration of
TWCA's request, EPA agreed during the planning and scoping phase not to
require that the Superfund RI/FS be conducted in such a way as to interfere
with TWCA's ongoing operations. Potential areas of contamination under
existing buildings and structures on the facility were not investigated for
potential environmental damage during the RifFS. Instead, EPA agreed to
defer such investigations to a later stage in the process during the remedial
design/remedial action (RD/RA) stage and agreed that such investigations
could be scheduled to be integrated into the normal course of TWCA's
operations such as when TWCA might schedule a building or structure to be
razed.
However,. cost-effectiveness must also strike an appropriate balance with long
term effectiveness and protection of human health and the environment. In the
RI/FS, TWCA analyzed several options for cleanup of contaminated soU and
groundwater at the TWCA Site in accordance with the prior agreement (the
Administrative Consent Order or 8AOCN) with EPA. However, TWCA's analysis
did not take into account the possibility that contamination may exist in those
currently uninvestigated portions of the Site beneath existing buildings and
structures. The analysis did not propose a mechanism for dealing with the
adverse impact on the cleanup from such potential sources of continued
contamination. Thus TWCA's analysis in the RI/FS did not provide supporting
data to demonstrate that the cleanup options it analyzed would be effective in
the long term.' Should contamination from uninvestigated sources interfere with
cleanup actions, those cleanup actions may not prove to be effective. For
example, contaminated soil. beneath existing structures could leach
contaminants into remediated areas rendering cleanup ineffectual and posing
additional changes in cleanup actions and costs.
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EPA's Selected Remedy is designed to allow TWCA flexibility in order to resolve
questions regarding the uninvestigated areas and to minimize interference with
TWCA's ongoing operations while still taking steps to contain the sources of
contamination. That flexibility would allow TWCA to schedule investigations of
those areas underneath buildings and structures for times when such
investigations would not interfere with TWCA's ongoing operations. One
example of this might be when in the course of its business operations TWCA
determines for its own business purposes that a building is to be razed or that
a paved surface needs to be dug up. At such time, TWCA would be' able to
schedule investigations of contamination beneath those buildings or paved
areas with minimal interference with its business operations.
EPA's Proposed Plan and selected remedy consider the cost effectiveness by
evaluating the additional protectiveness afforded by groundwater extraction and
pretreatment, and environmental evaluations of previously uninvestigated areas
versus the additional costs associated with these measures. Among other
things, provision is made for TWCA to conserve resources and utilize existing
equipment in order to minimize cleanup expenditures. Those cost-effective
provisions include; (1) allowing TWCA to convert existing groundwater wells to
extraction wells, (2) allowing TWc;:,A to utilize its existing wastewater treatment
facility for treatment of extracted contaminated groundwater, and (3) allowing
TWCA the flexibility to schedule investigation of potentially contaminated areas
beneath existing buildings and structures in such a way as to minimize impact
on TWCA's ongoing business operations.
2)
COMMENT: Several commenters, including the District 36 Representative to
the Oregon State legislature, suggested that the Proposed Plan for cleanup
might be unrealistic and ineffective. The commenters based this interpretation
on the belief that the proposed remedy reflected an assumption by EP A that
people would be drinking water from an on-site well which extracted its water
from the contaminated groundwater rather than drinking water from the-
municipal water system that provides potable water to TWCA and its neighbors.
One commenter also stated that it would not be possible for residences to be
constructed on Site because residential construction would not be in
accordance with local zoning regulations.
RESPONSE: The RifFS conducted by TWCA concluded that groundwater
beneath the TWCA Site is contaminated with volatile organic chemicals, PCBs,
and metals which are above state standards and standards established under
the federal Sate Drinking Water Act. In selecting a cleanup remedy, EPA is
obligated to consider and meet federal and state standards for protection of
groundwater quality. Oregon reg~lations require that contaminated
groundwater be restored to its highest use. The groundwater in the area of the
TWCA Site has been designated by the State of Oregon to be a potential
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drinking water source. even if currently that water is not used for drinking. In
the RI/FS, alternatives were analyzed for cleaning up the groundwater.
Included was an analysis of an alternative for restoring on-Site groundwater to
drinking water standards. The FS evaluation, which was conducted by TWCA.
showed that cleaning up the groundwater to drinking water standards was
feasible and cost-effective. Therefore, as a logical outgrowth of this analysis,
the EPA Proposed Plan included a provision for restoring groundwater beneath
the TWCA Site to drinking water levels.
In response to the concerns of TWCA and the community that cleanup of on-
Site groundwater to drinking water standards is unrealistic and that zoning
regulations preclude the installation of drinking water wells, this portion of the
selected remedy differs from the Proposed Plan. Although clean up to drinking
water standards still remains the goal of the groundwater clean up, the selected
remedy requires that TWCA actively clean up on-Site groundwater to levels
which are the minimum risk levels allowable under the Superfund regulations.
Instead of actively restoring groundwater, TWCA will be required to implement
measures to contain on-Site groundwater which is above the drinking water
standards. Natural dilution may then be relied upon to eventually clean up the
remaining contaminated on-Site groundwater to drinking water standards.
3)
COMMENT: Several concerned citizens, including representatives of local
businesses and a representative from the Area Chamber of Commerce,
suggested that EPA changed the rules in mid-stream and abandoned its good-
faith agreement with TWCA under the AOC by choosing a new, seventh
cleanup alternative and instead of selecting from the range of alternatives that
EPA and TWCA have formulated together for the past six years. The Chamber
of Commerce representative urged EPA to take steps to restore the cooperative
working arrangement with Teledyne and suggested, as the first step in -
accomplishing that goal, that a cleanup alternative evaluated in the TWCA RI/FS
be considered. One commenter stated that EPA was ignoring the earlier $5.4
million Superfund study conducted by CH2M Hill for TWCA, which measured
contamination in soils, groundwater, and stream sediment and presented a
range of cleanup alternatives that would protect human health and the
environment.
RESPONSE: EPA and Teledyne have worked cooperatively on the RI/FS and
EPA anticipates that the cooperative working relationship will continue. EPA's
Proposed Plan was designed to address several issues and fill certain data
gaps posed by the TWCA studies because of the site-specific circumstances of
the Teledyne Wah Chang facility. -TWCA evaluated cleanup alternatives which
do not address the data gaps.
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,<
In negotiating the technical requirements for the RifFS with Teledyne in 1987,
EPA agreed at that time to be sensitive to minimizing the impact of the
Superfund studies on Teledyne's ongoing operations. Because of those efforts
to enable Teledyne to continue its business operations relatively uninterrupted,
some delay has necessarily ensued in the search for some contaminant
sources. That agreement was made by EPA for the purpose of making
reasonable accommodation for TWCA's specific concerns regarding operation
of its business. However, that agreement to attempt to minimize impact on
Teledyne's ongoing operations was not a determination by EPA that potential
contaminant sources would not require investigation and identification at a later
date. As a result of that agreement, during the RIjFS stage, studies for
contaminant sources were conducted only in areas of the TWCA facility where
there were no ongoing operations. Investigation for potential contamination
from areas under existing buildings and structures on the facility was deferred
to a later stage when such investigations could be scheduled so as to minimize
interruption to Teledyne's ongoing business operations.
TWCA analyzed several options for cleanup of contaminated soil and
groundwater at the TWCA Site in accordance with the agreement EPA has
questioned the effectiveness of the cleanup options analyzed by TWCA
because those options do not take into account the possibility that
contamination in those currently uninvestigated portions of the Site beneath
existing buildings and structures could impede the effectiveness of the remedy.
These questions or data gaps have been documented by EPA several times in
letters sent to TWCA prior to issuance of the Proposed Plan. In addition, the
TWCA RifFS did not fully evaluate soil cleanup options. In order to resolve
questions regarding the effectiveness of the cleanup alternatives analyzed by
TWCA, and in order to ensure that soil cleanup options were fully evaluated,
EPA built upon TWCA's six evaluated alternatives and analyzed a seventh
alternative in the, Proposed Plan. That seventh alternative included co"'!ponents
from Alternative 6 and also incorporated a provision for analyzing the currently
uninvestigated areas. That seventh alternative, modified in accordance with
public comment, is the selected remedy for the site. EPA has the authority to
amend the evaluation of alternatives if EPA deems it necessary. TWCA is
cognizant of EPA's authority in this matter. Paragraph 31.B of the AOC (the
-good faith agreement"), EPA Docket No. 1086-02-19-106, to which TWCA and
EPA are co-signatories, provides that EPA will make amendments to the RI/FS
if EP A deems it necessary.
As stated above, EPA anticipates that a cooperative relationship will continue
with TWCA. In response to comments raised by concerned citizens and by
TWCA, EPA has incorporated certain provisions of the selected remedy that
differ from the Proposed Plan. The groundwater extraction element of the
selected remedy incorporates a number of contingencies so that groundwater
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extraction may be implemented using a phased approach if warranted. The
selected remedy requires TWCA to conduct an analysis of the best practicable
technology (BPT) to be used to pretreat extracted contaminated groundwater in
accordance with the Clean Water Act (CWA). The source reduction element of
the Proposed Plan has been deferred in response to concerns raised by TWCA
that a requirement to impose source reduction measures would directly interfere
with its ongoing processes. EPA expects that TWCA will voluntarily implement
source reduction measures. However, should the effectiveness of the selected
remedy be adversely affected because of continuing spills and leaks of
hazardous substances from the TWCA facility to the environment, EPA may
require that TWCA implement source reduction measures in the future. In
addition, source reduction measures may be required of TWCA by other federal
and/or state environmental statutes, such as the Resource Conservation and
Recovery Act (RCRA).
4)
COMMENT: One commenter wondered whether EPA's Proposed Plan is based
on proven cleanup technology that may have changed since the RI/FS and
whether there might be some more recent technology that might be more cost
effective in mitigating health risks and environmental damage. The commenter
also wondered whether EPA has abandoned earlier agreements with TWCA (the
AOC) based on the RI/FS in response to a changing political agenda.
RESPONSE: The Proposed Plan considered, and the ROD has selected,
cleanup technologies that were evaluated in the RI/FS. EPA's Proposed Plan
and EPA's Selected Remedy in the ROD are a modificaton, not an
abandonment, of the altematives evaluated in the TWCA RifFS. As
documented in the comments in the Administrative Record, EPA has relied on
the RI/FS for the information used in its decision-making process for the
Superfund cleanup of the TWCA Site.
Proven cleanup technology has not changed since TWCA submitted the RI/FS
to EPA. Most cleanup technologies that were evaluated in detail in the TWCA
RI/FS have been utilized in the past at many Superfund sites. These cleanup
technologies include pump and treat for groundwater, excavation and removal
of sediment, and flushing of subsurface contaminants. The TWCA RI/FS did
conclude that flushing of subsurface contaminants in the vicinity of the Feed
Makeup Area is not a proven technology. However, this technology is very
uncomplicated and easily implementable. Water will be injected into the ground
to leach the contaminants from the subsurface source into the groundwater.
The contaminated groundwater will then be extracted and used in TWCA's
existing processes for resource recovery of zirconium. However, in order to
ensure that flushing of subsurface contamination will indeed be effective at
TWCA, the RI/FS recommended, and the selected remedy requires, that pilot
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tests be conducted prior to fully implementing this technology at TWCA. The
Proposed Plan did not fully explain the simplicity of the flushing technology nor
the requirement for pilot testing. The ROD clearly sets out the simplicity of this
technology and the requirement for pilot testing.
5)
COMMENT: Several commenters, including a representative from the City of
Albany, expressed concems regarding the impact implementation of Alternative
7 might have on TWCA's ability in business to adapt competitively. For
example, commenters were concerned that TWCA's business would be
hindered if EPA required TWCA to apply for permission every time the facility
sought to make a change in process or equipment The City of Albany
representative further stated that EPA approvals are always cumbersome and
time-consuming. The commenters believed that such a prolonged process
would make it virtually impossible for TWCA to remain flexible and competitive
to its foreign competitors at a time when responsiveness to marketplace
changes are critical for continued success in business.
RESPONSE: As set forth in the Proposed Plan, throughout the ROD, and in
Comment 1 of this Responsiveness Summary, EPA has always given special
recognition to the particular concerns presented by the fact that TWCA is an
active 1acility with ongoing operations. Certain data gaps in the RifFS are a
result of EPA's agreeing to an approach to investigation of contamination that
permits TWCA to defer some of those investigations until it can reasonably do
so with minimal interference with its ongoing operations. Because 01 concerns
regarding the effectiveness of the cleanup remedy at an active facility, the
Proposed Plan and the selected remedy in the ROD include a provision for
environmental investigations of previously uninvestigated areas currently
underneath existing buildings and structures at the TWCA facility. This
investigation is not designed to be cumbersome, nor is it designed to i~terfere
with TWCA's ongoing operations. Sampling and analyses of these currently
uninvestigated areas will be conducted on a timeframe which is compatible with
TWCA's ongoing operations. Sampling and analyses will be limited to potential
contamination in the uninvestigated areas and to the effect of that contamination
on the overall Superfund deanup, so that costs 01 the evaluation should be
minimized. Extensive EPA oversight of environmental evaluations should not be
required. The Proposed Plan and selected remedy allow TWCA the flexibility to
determine when it would be most practicable to investigate those previously
uninvestigated areas. Environmental evaluation reports will be submitted by
TWCA to EPA and DEO once every two years.
In response to concerns raised by TWCA and the community that the Proposed
Plan would interfere with ongoing operations, the source reduction element
described in the Proposed Plan has been deferred pending the future evaluation
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of the effectiveness of the Superfund cleanup. This element would have
required TWCA to implement and evaluate source reduction techniques to
minimize current and future releases of hazardous substances at the facility.
Since TWCA is currently regulated under additional federal and state
environmental regulations, EPA expects that TWCA will implement source
reduction measures voluntarily in order to be in compliance with those
regulations. However, EPA retains authority to impose source reduction
requirements on TWCA in the future if it is determined that ongoing operations
are adversely affecting the Superfund cleanup.
6)
COMMENT: Several concerned citizens, including members of the business
community in Oregon City, Halsey, Corvallis, and Albany, Oregon, expressed
concerns that the Proposed Plan duplicates existing regulatory programs
enforced by state and other federal agencies. Some of these commenters felt
that state and federal agencies are currently monitoring every component of
TWCA operations, adding another layer of unnecessary regulations that would
be redundant, excessive, and irrelevant in protecting human health and the
environment.
RESPONSE: EPA's Superfund program works closely with other federal
environmental programs such as the federal Clean Water Act (CWA) and the
Resource Conservation and Recovery Act (RCRA), and with the State agencies
. to coordinate environmental requirements and to avoid redundancy. CERCLA
requires that Superfund cleanup actions comply with all existing applicable or
relevant and appropriate federal and state environmental regulations (commonly
referred to as ARARs). In ensuring that a Superfund cleanup action is
appropriately implemented, EPA's Superfund program needs to ensure that the
remedy itself does not adversely impact the environment. One method of
ensuring this is to make sure that the cleanup action complies with A~Rs.
For example, in the case of the TWCA site, EPA has concerns about whether
groundwater treatment and discharge alternatives that were evaluated by TWCA
in the RljFS would fully comply with certain requirements of the CWA in regard
to TWCA's water discharge from its facility under its CWA NPDES permit. For
the Superfund action, TWCA evaluated groundwater cleanup options which
would require extraction of contaminated groundwater and discharge of this
contaminated groundwater to its existing wastewater treatment facility without
pretreatment prior to discharge. EPA's Superfund program, in consultation with
the CWA program and with the state agencies, has determined that
pretreatment prior to discharge is necessary because the addition of untreated
water from the Superfund cleanup to TWCA's existing wastewater treatment
system could increase contaminant levels in the discharged water and cause a -
potential violation of the CWA. TWCA's existing NPDES permit did not envision
-------
discharge of organic and radio nuclide contaminants to surface water as a result
of a Superfund cleanup action. The CWA requires that this contaminated
groundwater be treated using best practicable technology (BPT) prior to
discharge to surface water, rather than allowing mere dilution to be the
. treatment. Under TWCA's existing NPOES permit, wastewater is currently
discharged first to Truax Creek where it moves into the Willamette River. In
order to prevent further contamination of Truax Creek and/or the Willamette
River, additional pretreatment of contaminated extracted groundwater using BPT
may be required. This additional pretreatment requirement under CERCLA is
not redundant. Rather, the pretreatment requirement seeks to ensure that the
CWA requirements for protection of human health and the environment at the
TWCA site are not undermined by discharge of contaminated water from the
Superfund remedial action.
EPA and OOEa are coordinating Superfund and RCRA activities at the TWCA
facility. These activities are designed to complement each other rather than to
be redundant. Superfund cleanup actions are not intended to be duplicative of
RCRA actions, or any other environmental regulation.
7)
COMMENT: Several commenters expressed disappointment that EPA would
require TWCA to implement Alternative 7. The commenters believed that the
cleanup plan described in Alternative 7 had not been considered for feasibility
and consisted of too many .blank checks. O.e. ways in which EPA could later
impose additional requirements and costs on TWCA). One commenter stated
that EPA's alternative may require the construction of a groundwater
pretreatment facility yet EP A had not addressed the cost of building such a
facility. Similarly, commenters thought that costs and feasibility had not been
fully evaluated for additional sampling and analysis that might be required and
that .source reduction techniques. might be required but that the Proposed Plan
did not specify what those source reduction techniques would be. Conimenters
gave these as examples of vagueness and open-endedness in EPA's proposed
Alternative 7.
RESPONSE: EPA's proposed Alternative 7 was based on evaluation and data
provided in the RI/FS which was conducted by Teledyne under EPA oversight.
EPA's proposed Alternative 7 incorporated components of the Alternative 6 in
the RI/FS with additional components based on other factors such as the ability
of cleanup actions to be effective at a facility with complex ongoing operations.
EPA's Alternative 7 as outlined in the Proposed Plan was designed to be a
comprehensive cleanup remedy for contaminated groundwater, soil, and
sediment at the TWCA Site. -
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As part of its evaluation of cleanup alternatives in the RifFS, TWCA itself
evaluated the feasibility of discharging extracted groundwater to TWCA's
existing wastewater treatment plant. However, the existing wastewater
treatment plant is not designed to treat many of the contaminants which would
be found in the extracted groundwater such as volatile organic compounds.
Discharging contaminated groundwater directly to surface water without treating
the contaminants would be in violation of the CWA. Therefore, the proposed
Alternative 7 and the selected remedy in the ROD incorporates a provision
which requires TWCA to analyze the BPT which can be used to pretreat the
extracted groundwater prior to discharge to its wastewater treatment system. In
its evaluation in the RifFS, TWCA did not analyze the cost of such additional
pretreatment. The analysis of BPT, to be conducted during the remedial
design, will incorporate an evaluation of cost-effectiveness. However, EPA
expects that the amount of groundwater to be pretreated will not be substantial,
and the technology which will be utilized to treat the contaminants found in
groundwater at the site will be readily available at reasonable cost.
In deference to concerns of the community and TWCA, EPA has deferred the
requirement for implementation of source reduction as part of the selected
remedy at this time. EPA expects that TWCA would voluntarily implement some
source reduction techniques as part of its operating procedures.
Implementation of source reduction would prevent TWCA from expending funds
for potential future environmental cleanup as a result of potential future spills or
leaks of hazardous substances from TWCA's ongoing manufacturing processes
into the environment. EPA retains authority to impose source reduction
requirements on TWCA in the future if it is determined that TWCA's ongoing
operations are adversely affecting the Superfund cleanup.
Due Process
8.
COMMENT: Several commenters, including the District 37 Representative to
the Oregon State Legislature, expressed disappointment that EPA had not
allowed TWCA adequate time to state its case at the public meeting for
comments on the Proposed Plan. Commenters thought EPA should have
allowed TWCA more than five minutes to defend its own alternatives as well as
to respond in detail to EPA's Proposed ~Ian.
RESPONSE: .EPA policy at a public meeting to take comments on a Proposed
Plan is to allow each commenter equal time to comment. The PRP (in this
case, Teledyne) is allowed no more or less time than any other commenter
unless excess time is left after all Who wish to do so have had an opportunity to
comment. The rationale for allowing a limited amount of time for each party to
present oral comments at a public meeting is to give everyone an opportunity to
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comment. At the beginning of the public meeting on the Proposed Plan all
commenters were asked to sign up prior to beginning the portion of the
meeting designated to take oral comments. Everyone, including TWCA
representatives, was free to sign-up. A count was then taken of the total
number of commenters, equal time was allocated accordingly, and commenters
were invited to comment in order of sign-up. At the public meeting, TWCA's
legal counsel signed up to comment and used more than twenty minutes
. (almost four times as long as any other commenter) to present oral comments
at the meeting. EPA accommodated this excess use of the comment time
allotted by expanding the timeframe of the public meeting by about one hour in
order that no commenter who wished to make oral comment would lose the
opportunity to do so.
In addition, TWCA has been given several other opportunities to state its case
to EPA and for the public record. On June 30, 1993, prior to issuance of the
Proposed Plan. EPA officials met with TWCA representatives, at TWCA's
request, to explain EPA's rationale for the proposed Superfund cleanup. At this
meeting EPA offered to allow TWCA to participate with EPA in explaining the
results of its RI/FS at the public meeting on the Proposed Plan. EPA issued the
Proposed Plan on August 27, 1993. One week prior to the public meeting,
TWCA tumed down EPA's offer giving as the reason that it disagreed with
EPA's proposed Alternative 7. TWCA requested that particular time be allotted
to it at the public meeting to comment on EPA's Proposed Plan. EPA explained
that no particular block of time would be allocated especially for TWCA
comments but that TWCA would have the same opportunity as all other
commenters to make comments on the record at the public meeting. At the
public meeting, as described, TWCA legal counsel used twenty minutes (more
than any other commenter). .
On September 24, 1993 Teledyne requested, and EPA granted. an exte_nsion of
the public comment period until October 27, 1993. This extension of the public
comment period was given by EPA in order to allow TWCA to submit its written
comments on the Proposed Plan to EPA in a timely fashion. TWCA submitted
its written comments on October 5, 1993. At TWCA's request, EPA once again
met with TWCA legal and technical representatives on October 15, 1993 so that
TWCA could once again present its position for the record. TWCA presented
its position in great detail and this meeting was recorded for the public record.
A transcript of this meeting is available in the Administrative Record. On
October 27, 1993 TWCA submitted supplemental written comments on the
Proposed Plan.
TWCA has been given every opportunity to comment orally and in writing on
the Proposed Plan. EPA has al50 accommodated every request by TWCA to
meet with EP A representatives to present its comments.
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Risk Assessment and Risk Related Issues
9.
COMMENT: One commenter suggested that the Proposed Plan did not clarify
the distinction between risk management and risk assessment. This
commenter expressed the belief that uncertainties in the risk assessment had
not been adequately addressed in the Proposed Plan and that EPA had failed
to clearly communicate the degree of risk to the public. .
RESPONSE: The Superfund regulations utilize a two step approach in
determining the risks to the public from a Superfund site. Risk assessment, the
first step, involves quantifying risks by conducting a baseline risk assessment.
This risk assessment is based upon the nature and extent of contamination at
the site and assesses risks to the public if no cleanup actions were conducted
at the site. Risk management, the second step, involves consideration of a
variety of site-specific or remedy-specific factors, such as the current and
projected future usage of the site. Such factors enter into the determination as
to how risks will be managed and what cleanup levels will be established for the
particular site.
The Superfund regulations require that actions selected to clean up hazardous
waste sites be protective of human health and the environment. To help meet
this Superfund mandate, EPA has developed a standardized risk assessment
process as part of its cleanup response program. The objectives of this
process are to: (1) provide an analysis of baseline human health and ecological
risks and help determine the need for action at sites; (2) provide a basis for
. determining levels of chemicals that can remain on site and still be adequately
protective of public health and the environment; (3) provide a basis for
comparing potential health and ecological impacts of various cleanup
alternatives; and (4) provide a consistent process for evaluating and
documenting public health threats at sites.
The TWCA Risk Assessment was performed following standard EPA
procedures. Certain aspects of these procedures are applied uniformly to all
Superfund sites in order to be able to evaluate risks consistently. The
methodology used to assess risks inherently involves some uncertainty.
Uncertainty can occur as a result of the initial selection of contaminants of
concern used to characterize exposures and risk on the basis of the sampling
data and available toxicity information. For example, if a spill or leak into the
environment of a chemical that wasn't previously identified in the TWCA RI/FS
would occur then risks due to this chemical would not have been evaluated.
Other uncertainties are inherent When assuming that chemicals that cause
cancer in animals also cause cancer in humans. Additional uncertainties, such
as attempting to predict future land use, are also inherent in assessing
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10. .
exposure for individual substances and for individuals. Such uncertainties are
generally inherent in assessing risks at all hazardous waste sites. These
uncertainties are taken into account when making determinations based on the
risk assessment. The TWCA risk assessment included an assessment and
presentation of uncertainties which EPA evaluated during the remedy selection
process. Information and explanations on risks from the TWCA Site have been
communicated many times to the public in the past via fact sheets, open
houses, and public meetings.
Risk management under the Superfund regulations, requires that on-site
contaminants which exceed certain risk levels be cleaned up. The regulations
also describe a range of risk levels which can be managed on site. One
example of how risk management is applied at the TWCA site may be seen in
the remedial actions required for groundwater which are presented in the ROD.
For groundwater at the TWCA Site, some areas exceed the risk levels allowable
under the Superfund regulations. These areas must be cleaned up as part of
the selected remedy. However, there are some areas of groundwater at the
TWCA facility in which the contaminant levels exceed drinking water standards,
but do not exceed the maximum allowable risk level under the Superfund
regulations. These areas of contaminated groundwater will be managed or
contained on site, and active cleanup of those areas should not be required.
COMMENT: Several commenters requested the specific formulas and factors
that went into. calculating risks. These commenters wanted to know how these
factors were derived.
RESPONSE: This response is necessarily presented in summary form. More
detailed information on the bases for risk assessment is included in the TWCA
Risk Assessment Report which is Volume III of the RifFS. The comple~e RifFS
including the Risk Assessment was made available for review during the public
comment period. The RifFS also forms part of the Administrative Record for
the TWCA site. The Administrative Record is available for review at the Albany
Public Ubrary in Albany, Oregon, and at EPA's Region 10 Superfund Records
Center in Seattle, Washington.
For contaminants at the TWCA site, the calculation of risk involved a 4-step
process which included the identification of contaminants of concern, an
assessment of contaminant toxicity, an exposure assessment of the population
at risk, and a characterization of the magnitude of risk.
During the first step, fifty four chemicals were identified as chemicals of potential
concern in soils and groundwater at the site. The chemicals of potential
concern were selected based on whether; (1) .the concentration of the chemical
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on site exceeded naturally occurring levels, (2) whether EPA had previously
studied the chemical and established a level of human toxicity, and (3) the
maximum detected concentration exceeded levels known to have health effects
on laboratory animals in controlled experiments.
The second step includes gathering known toxicity information for the chemicals
of concern at the site. Toxicity information was provided in the RifFS for the
chemicals of concern. Cancer risks for each chemical are then calculated using
toxicity factors known as slope factors (SFs), while noncancer risks rely on
reference doses (RfDs).
SFs have been developed by EPA for estimating excess lifetime cancer risks
associated with exposure to potential carcinogens. SFs are then multiplied by
the estimated intake of a potential carcinogen to provide an upper-bound
estimate of the excess lifetime cancer risk associated with exposure at that
intake level. The term .upper bound" reflects the conservative estimate of the
risks calculated from the SF. Use of this approach makes underestimates of
the actual cancer risk highly unlikely. SFs are derived from the results of
human epidemiological studies, or chronic animal bioassay data, to which
mathematical extrapolation from high to low dose, and from animal to human
dose, have been applied.
RfDs have been developed by EPA to indicate the potential for adverse health
effects from exposure to chemicals exhibiting noncarcinogenic effects. RfDs are
estimates of lifetime daily exposure for humans, including sensitive
subpopulations likely to be without risk of adverse effect. Estimated intakes of
contaminants of concern from environmental media (e.g. the amount of a
contaminant of concern ingested from contaminated drinking water) can be
compared to the RfD. RfDs are derived from human epidemiological studies or
animal studies to which uncertainty factors have been applied.
The third step, or exposure assessment, identified potential pathways for
contaminants of concern to reach the exposed population. Exposure
assumptions were based primarily on EPA regional and national guidance. The
RI/FS evaluated exposure to current and future workers on the plant site, and
to potential future residents in the Farm Ponds Area. The Soil Amendment Area
and adjoining land to the northeast and northwest of the Farm Ponds is
currently being used for agricultural purposes, therefore EPA further
supplemented the evaluation in the Farm Ponds Area by evaluating an
agricultural worker scenario in the Soil Amendment Area.
Human exposure to chemicals in -groundwater can occur through ingestion of
drinking water, by dermal contact during bathing, handwashing etc. or by
inhaling chemicals volatilized from water during showering, cooking, or other
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household activities. The RifFS determined that groundwater generally flows in
a westerly direction below the TWCA Site to the Willamette River. TWCA
currently uses water supplied by the local municipal system. In addition, a
beneficial use survey conducted during the RifFS indicated that there are no
current off-Site users of groundwater for drinking water purposes. For these
reasons, the Baseline Human Health Evaluation concluded that there are no
current receptors for groundwater exposures. Therefore, only exposure of
contaminated groundwater to future workers on the main plant and potential
future residents in the Farm Ponds Area were evaluated.
Exposure point concentrations for the TWCA site were derived in a manner
consistent with the EPA guidance to evaluate Reasonable Maximum Exposures
(RMEs). The RME is defined as the highest exposure that is reasonably
expected to occur at a site.
In the fourth and final step, risks are calculated for carcinogen and
noncarcinogen chemicals. For carcinogens, risks are estimated as the
incremental probability of an individual developing cancer over a lifetime as a
result of exposure to the carcinogen. Excess lifetime cancer risk is calculated
by multiplying the SF by the .chronic daily intake. developed using the exposure
assumptions. These risks are probabilities generally expressed in scientific
notation (e.g. 1 x 10""). An excess lifetime cancer of 1 x 10'" means that an
individual has a 1 in 10,000 chance of developing cancer as a result of site-
related exposure to a carcinogen under the specific exposure conditions
assumed.
The potential for non-carcinogenic effects is evaluated by comparing an
exposure level over a specified time period (e.g. lifetime) with a reference dose
derived for a similar exposure period. Hazard quotients are calculated by
dividing the chronic daily intake by the specific RfD. By adding the hazard
quotients for all contaminants of concern that affect the same target organ (e.g.
liver), the hazard index (HI) can be generated.
The RME"provides a conservative but realistic exposure in considering remedial
action at a Superfund site. Based on the RME, when the excess lifetime cancer
risk estimates are below 1 x 10-6 (1 in 1,000,000), or when the noncancer HI is
less than 1, EP A generally considers the potential human health risks to be
below levels of concern. Remedial action is generally warranted when excess
cancer risks exceed 1 x 10-4. Between 1 x 10-6 and 1 x 10"', cleanup mayor
may not be selected, depending on individual site conditions including human
health and ecological concerns.
The potential human health risks at the TWCA Site were characterized by
estimating risks on a sample-specific basis. This approach retains information
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on the geographic distribution of risk throughout the study area. The sample
specific risks were used to distinguish specific areas of the TWCA site that
exceed risk-based levels.
More detailed information regarding specific numbers and factors which were
used in calculating risks at the TWCA site can be found in the TWCA Risk
Assessment Report which is Volume III of the RifFS Report. This report is part
of the Administrative Record, and is available at the locations mentioned in the
first paragraph of this comment.
11.
COMMENT: One commenter pointed out that only rye grass is being grown in
the agricultural area north of the TWCA facility (the Soil Amendment Area).
Thus, there is no direct impact of contamination in this area to human health.
RESPONSE: While the Soil Amendment Area is currently being used to grow
rye grass, future use of this area is uncertain at this time. EPA is aware that the
area is currently zoned for industrial purposes. EPA has evaluated an
agricultural use scenario for this area which is less-stringent than the future
residential use scenario which was evaluated in the RifFS. Subsequent to the
public meeting on the Proposed Plan, EPA determined that contamination in
this area would be best addressed as part of a separate operable unit. .
Therefore, the selected remedy cleanup actions for the Soil Amendment Area
are being deferred until EPA obtains more information regarding the nature and
extent of contamination in this area. Cleanup in the Soil Amendment Area will
then be addressed as part of Operable Unit Three at the TWCA Superfund Site.
12.
COMMENT: One commenter stated that it was illogical to list fluoride and
nitrate as contaminants of concern with potential adverse risk effects because
fluoride is commonly added to drinking water as a beneficial substance-to
provide protection from tooth decay and nitrate is commonly used in fertilizer.
RESPONSE: Common substances, beneficial in small amounts or when used
appropriately may nevertheless be harmful in larger doses or when used
inappropriately. Ruoride is added to drinking water in small concentrations and
is absorbed into bone to help prevent bone and teeth deterioration. However,
when humans are exposed to excessive fluoride concentrations over long
periods of time the excessive exposure can actually cause damage to bones
and teeth. This condition is called fluorosis.
Similarly excess nitrate can be harmful. Nitrate is converted to nitrite when it
enters the body. Nitrite reacts with hemoglobin in the blood to form
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methemoglobin. Methemoglobin reduces the ability of the blood to transport
oxygen to tissues.
RI/FS Issues
13.
COMMENT: Several commenters, including a representative from the City of
Millersburg, suggested that EPA should consider the economic health of the
local community when exploring alternatives to clean up the site.
RESPONSE: EPA has been sensitive to the concerns expressed by TWCA
and by the community. The RI/FS was designed to minimize impact on
TWCA's active operating facility. The FS evaluation of cleanup alternatives for
the TWCA site included an evaluation of the cost and implementability of the
various alternatives. EPA has modified the Proposed Plan and has selected a
cleanup remedy which is largely based upon the evaluation conducted in the
FS, is designed to be cost-effective, and which addresses the concerns of the
community. Superfund cleanup actions at TWCA should have minimal effect on
TWCA's ongoing operations. EPA understands the concerns of the community
and expects to work closely with TWCA to minimize impacts of the cleanup on
TWCA's ongoing operations. .
14.
COMMENT: One commenter stated that the groundwater at TWCA was
extensively sampled. He also questioned why EPA should care whether or not
leaks come from underneath buildings at the TWCA site since no evidence was
presented that contaminated groundwater leaves the site.
RESPONSE: EPA is concerned about the risks to human health and the
environment from exposure to contaminated groundwater that leaves t~e TWCA
site and that flows to surtace water bodies such as the Willamette River. Some
of the contaminants of concern in the groundwater include volatile organic
chemicals and radionuclides which can cause cancer in humans and animals.
Groundwater at the TWCA site was sampled and groundwater levels were
measured at over 60 wells during the RifFS. From these samples and
measurements, the RifFS concluded that contaminated groundwater was
rnigrating to and entering surtace water on and adjacent to the site. Adjacent
off-site surtace water bodies include the Willamette River. In addition, the RifFS
concluded that in some areas of the site, contaminated groundwater could be
exiting the site prior to moving toward surtace water. Any potential Mure leaks
or spills of hazardous substances from structures on the TWCA facility could
create additional hot spots and source areas on the site which could expand
the groundwater contamination and thus negatively impact both groundwater
and surtace water adjacent to the site.
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15.
COMMENT: Several commenters questioned why EPA is continuing to use
cleanup technologies that have repeatedly proven ineffective.
RESPONSE: None of the technologies which were evaluated in the RIjFS and
by EPA have proven to be ineffective. Commenters who believe that some of
the technologies are ineffective may be basing that belief on recent data which
indicates that groundwater extraction may not be effective in achieving drinking
water standards. However, groundwater extraction has proven to be effective in
containing contaminant plumes and in achieving significant mass removal of
contaminants. The selected remedy for groundwater cleanup at the TWCA site
calls for containing groundwater contamination on site, and for extraction of
groundwater at those wells which have very high levels of contaminants. Once
contaminants are contained on the Site, and the high levels of contamination
are cleaned up, natural dilution can be relied upon to further reduce
contaminants to cleanup goals such as drinking water standards.
16.
COMMENT: One commenter questioned why there was an Alternative 7 and
why was it not developed during the comprehensive study process of all viable
alternatives.
RESPONSE: At TWCA's request so as not to interfere with TWCA's ongoing
manufacturing processes, the RifFS was designed to be conducted in areas of
the facility where there were no ongoing operations. Therefore several
limitations were placed on the design of the RifFS and on the work plans
submitted by TWCA to EPA prior to implementation of the RifFS, necessarily
resulting in certain data gaps. These limitations on the RIjFS allowed TWCA to
exclude from investigation at that time areas underneath existing buildings and
structures on the facility which were not investigated for potential enviroJ1mental
damage. However. TWCA did not provide in its six alternatives for the Mure
investigation of those potential contaminant source areas. Potential negative
environmental impacts of spills and leaks from ongoing operations and existing
structures on the Site were not considered in the TWCA RifFS. In addition,
EPA is concerned that the discharge of extracted groundwater to TWCA's
existing wastewater treatment facility as described in the RifFS could potentially
violate CWA regulations. Because of these concerns, EPA recognized that
implementation of any of the six alternatives evaluated by TWCA may not prove
to be effective-as a comprehensive long-term remedy for the TWCA Site.
EPA evaluated a seventh alternative that would address these concerns.
Alternative 7 includes componentS of the alternatives evaluated in the TWCA
RifFS with additional components to address the additional concerns. EPA has
the authority to amend the evaluation of alternatives if EP A deems it necessary.
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Based upon the limitations of the RifFS as described above, EPA therefore
found it necessary to evaluate a seventh alternative.
Miscellaneous
17.
COMMENT: One commenter requested that EPA and TWCA continue the
process together and build on a positive history for the health of the
community .
RESPONSE: EPA expects to work closely and cooperatively with TWCA to
implement the selected remedy in the ROD. EPA has given TWCA ample
opportunity to work together and will continue to do so in the future. As part 01
the Superfund process, TWCA will be given a period of time to negotiate the
implementation of the selected remedy. EPA hopes that TWCA will step
forward and voluntarily agree to conduct the necessary cleanup work. Such an
agreement would be formalized in a legal document called a consent decree.
18.
COMMENT: One commenter and the District 37 Representative to the Oregon
State Legislature suggested that risks should be solved by Alternative 3 outlined
in the RifFS. Alternative 3 was the cleanup alternative recommended by TWCA.
These commenters further stated that there should be no prolonged human
exposure and no risk, and .the problem would be resolved in the same
timeframe if Alternative 3 were implemented.
RESPONSE: Alternative 3, which includes slope erosion protection along Truax
Creek, and groundwater extraction at only the Feed Makeup and Farm Ponds
areas of the site, would not meet the cleanup goals established in the RifFS for
the TWCA site. If Alternative 3 were implemented, contaminated groundwater
would not be contained on site. Numerous identified contaminant sources on
the site would not be addressed or cleaned up. Contaminated sediments
would not be cleaned up. No measures would be taken which would prevent
the release of additional contamination from soil to groundwater, surface water,
air, and sediments therefore resulting in potential additional risks to human
health and the environment.
19.
COMMENT: Several commenters, including the Albany Chamber of Commerce
and local businesses, stated that TWCA has always been responsible and has
repeatedly demonstrated concerns for its employees, the community, and state
and federal environmental laws. -
RESPONSE: Comment noted.
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20.
22.
COMMENT: One commenter stated that EPA is incorrect by implying that the
facility is over 50 years old; TWCA celebrated its 35th anniversary in 1991.
RESPONSE: This commenter is correct. The facility has been at its' present
location since 1956. .
21.
COMMENT: A representative of the City of Albany stated that to set a
standard requiring TWCA to meet the federal safe drinking water requirements
is beyond all reasonable expectations.
RESPONSE: Under CERCLA, EPA is obligated to comply with the state of
Oregon regulations which require that groundwater be restored to its most
beneficial use. Groundwater beneath the TWCA site has been determined by
the state of Oregon to be a potential drinking water source. In order to comply
with the Oregon requirements, one of the cleanup goals for the TWCA site is to
reduce contaminants in groundwater to below drinking water standards.
However, in response to the concerns of TWCA and the community that
cleanup of on-Site groundwater to drinking water standards is unrealistic and
that current deed restrictions preclude the installation of drinking water wells,
the groundwater cleanup portion of the selected remedy in the ROD differs from
the Proposed Plan. Although clean up to drinking water standards still remains
the goal, the selected remedy requires that TWCA actively clean up on-Site
groundwater to levels which are the minimum risk levels allowable under the
Superfund regulations. Instead of actively restoring groundwater, TWCA will be
required to implement measures to contain on-Site groundwater which is above
the drinking water standards. After attaining clean up to minimum risk levels,
natural dilution may then be relied upon to eventually clean up on-Site
groundwater to drinking water standards.
COMMENT: One commenter expressed concern about the impact the
Superfund cleanup might have on the retention, expansion, and recruitment of
businesses into the area. This commenter thought that EPA's Proposed Plan
sends a message that is unclear and misleading to prospective businesses that
are looking to the Albany-Millersburg area and to other businesses looking
possibly to locate there because of the presence of TWCA.
RESPONSE: EPA's Proposed Plan and Selected Remedy are specific to the
TWCA facility and are not intended to adversely impact other businesses in the
area. EPA believes that cleaning up the TWCA facility will improve
environmental conditions in the Albany-Millersburg area and should enhance the
attraction of the area to other businesses.
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23.
COMMENT: Several commenters suggested that EPA should follow the TWCA
cleanup plan and start with Alternative 2 and progress to the point where TWCA
. comes into compliance. One commenter also stated that there is no
justification for choosing Alternatives 6 and 7 until lesser alternatives have failed.
RESPONSE: Alternative 2, which only specifies monitoring and institutional
controls, is not protective of human health and the environment. Furthermore,
Alternative 2 would not meet the cleanup goals established for the TWCA site,
and would not comply with existing environmental regulations. Because of site-
specific conditions presented by the fact that TWCA is an active, operating
facility, EPA has determined that the selected remedy is the most appropriate
means of achieving the cleanup goals. The selected remedy, which is a
modification of Alternative 7 based on public comment, utilizes a phased
approach for groundwater clean up at the TWCA Site.
24.
COMMENT: One commenter stated that the TWCA site should never have
been considered for inclusion on the National Priorities Ust (NPL).
RESPONSE: Inclusion of a site on the NPL is an objective nationwide process.
The TWCA site is on the NPL because it meets all the criteria for inclusion on
the list. Based upon information collected during site inspections, EPA uses its
Hazard Ranking System (HRS) to establish a score for the site. The HRS score
indicates whether hazardous substances have migrated, or may migrate,
through groundwater, surface water and air. Sites with high enough scores are
considered for inclusion on the NPL TWCA is one such site.
25.
COMMENT: One commenter was concerned about potential health risks to
children who play around the TWCA sludge ponds.
RESPONSE: Access control around the sludge ponds is an issue that_is of
concern to EPA. EPA's Proposed Plan included measures which will ensure
that access is limited in the Farm Ponds area. While any additional remediation
of the sludge ponds has been deferred until EP A obtains additional information
regarding the nature and extent of existing contamination in those areas, and
additional cleanup activities for the sludge ponds are not called for in this ROD,
EPA will ensure that access controls, such as fencing and posting of signs, are
implemented to minimize any health threat which the sludges may pose.
26.
COMMENT: Several commenters supported EPA's Proposed Plan. One
commenter was concerned that if Teledyne manages to avoid cleanup
responsibilities, it would be an open invitation for other large companies to
come and use Oregon as their dump site.
RESPONSE: Comments noted.
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Section 4
Response to Comments Received from the Potentially
Responsible Party
EP A also received comments from TWCA during the comment period (August
27, 1993 through October 27, 1993). TWCA submitted to EPA comments opposing
EPA's August 25, 1993 Proposed Plan. EPA, the Oregon Department of
Environmental Quality (DEQ), and TWCA met on October 15, 1993 to address any
outstanding issues which resulted from TWCA's comments submitted on October 5,
1993.
TWCA submitted supplemental comments on October 27, 1993, addressing
issues which arose from the meeting. Most of the supplemental comments were
issues that have already been addressed in prior submitted comments to, and
meetings with, EPA.
TWCA's comments are grouped in the following categories:
27-31
TWCA Believes EPA's Proposed Plan Violates The National
Contingency Plan, 40 C.F.R. Part 300 (NCP)
32-36
TWCA Believes EPA Has Applied Its Risk Assessment Guidance
Incorrectly
37
TWCA Believes The Community Strongly Opposes EPA's
Proposed Plan
38-39
Because TWCA Is An Active Operating Facility Subject to RCRA,
TWCA Believes The Plant Should No Longer Be Regulated Under
CERCLA
40-41
TWCA Believes EPA Has Failed to Articulate a Rationale for its
Proposed Plan
42
TWCA Believes The Proposed Plan Is Based on A Misapplication
of Oregon's Remedial Action Regulations
TWCA contended that EPA must withdraw its proposal and adopt TWCA's remedial
plan (Alternative 3) based on the following comments:
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TWCA Believes EPA's Proposed Plan Violates The National Contingency Plan,
40 C.F.R. Part 300 (NCP)
27.
COMMENT: TWCA stated that EPA has ignored the analytical framework in the
NCP by selecting a proposed plan (Alternative 7) that was not considered
during the RifFS process. Specifically, TWCA believed that the components of
Alternative 7 that were not evaluated in the RifFS include: the possibility of
additional pretreatment for groundwater; potential, but undefined, requirements
for soil remedial actions in the Feed Makeup Area; an evaluation of the
feasibility of soil removal instead of capping selected areas around the plant
site; an evaluation of source reduction techniques; and an environmental
evaluation whenever TWCA changes or discontinues use of any structure at the
plant.
TWCA felt that therefore, EPA's Proposed Plan (Alternative 7) was not subject to
the rigorous scrutiny and evaluation required by the NCP. TWCA thought that
EPA had failed to conduct the necessary evaluation of costs and effectiveness;
cost information for critical components of the Proposed Plan, such as
pretreatment, were unknown; and costs of construction, and long-term
operation and maintenance must also be considered. TWCA objected to the
fact that EPA had proposed a remedy that could be at least three and a half
times more costly than TWCA's recommended Alternative 3 and that, TWCA
felt, would be no more protective of human health and the environment than
TWCA's proposed remedy. TWCA thought that EPA had selected an infeasible
and ineffective plan that would cause TWCA and the community substantial
economic harm.
RESPONSE: In accordance with the NCP, the Proposed Plan is designed to
identify a remedial action alternative which best fits the requirements in S
3oo.430(f)(1) of the NCP. According to these requirements, before a r~medy
can be selected it must be protective of human health and the environment, and
comply with all federal and state applicable or relevant and appropriate
requirements (ARARs). In reviewing the TWCARI/FS, EPA had several
concerns with respect to the remedial alternatives evaluated by TWCA and their
ability to comply with ARARs. Specifically, all of the groundwater extraction
alternatives evaluated in the RI/FS would have discharged contaminated
extracted groundwater to TWCA's existing wastewater treatment system.
TWCA's existing wastewater treatment system is not designed to treat, nor is it
permitted to tFeat, most of the contaminants which are found in the
groundwater. These contaminants include volatile organic compounds (VOCs),
semi-volatile organic compounds (SVOCs), polychlorinated biphenyls (PCBs),
and radionuclides. For some of these contaminants (PCBs, and very high
levels of VOCs) the TWCA RI/FS evaluated some form of pretreatment prior to
discharge. However, the TWCA RI/FS failed to evaluate pretreatment options
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for the remaining VOCs in groundwater, SVOCs, and radionuclides.
Discharging contaminated groundwater to surface water without pretreatment
would not be in compliance with ARARs such as Section 402 of the Clean
Water Act, 33 U.S.C. 1342 which requires that effluent limitations in permitted
discharges be based in part upon treatment using the best practicable control
technology available (BPl). This means that TWCA is required to treat
contaminated groundwater prior to discharge to surface water. Since the
TWCA wastewater treatment facility does not have effluent limitations for the
above-listed contaminants, and since TWCA did not propose to use BPT as
pretreatment for those contaminants, the TWCA evaluated groundwater
alternatives would not meet the ARARs. Therefore the pretreatment
requirement was necessary for any of the groundwater proposals to meet
ARARs.
The proposal for potential, but undefined, requirements for remedial actions in
the Feed Makeup Area are based on the TWCA RifFS evaluation of in-situ
flushing of subsurface contamination in the Feed Makeup Area. Although
flushing of subsurface contaminants is an uncomplicated technology, the TWCA
RifFS stated that pilot tests would be conducted prior to initiating the flushing
technology. However, the RifFS did not evaluate additional cleanup options in
the Feed Makeup Area should the pilot test prove to be ineffective. The
Proposed Plan recognizes this deficiency in the RifFS, and proposes that
additional remedial actions such as source treatment or removal be
implemented in this area if the pilot tests prove to be ineffective.
Additional requirements in ~ 3oo.430(f)(1) of the NCP call for an evaluation of
the long term effectiveness and permanence of the remedial alternative. The
Proposed Plan recognizes that TWCA is an active facility with ongoing
operations. The Proposed Plan also acknowledges that the scope of the RifFS
was designed such that sampling activities would not interfere with TWQA's
ongoing operations. The Proposed Plan recognizes that in order for any
remedial actions to be effective in the long term at the TWCA facility, spills or
leaks of additional contamination into the environment"from ongoing operations
at the facility must be minimized. In addition, since some areas of the facility
were not investigated during the RifFS in order to minimize impact on ongoing
operations, contamination from those uninvestigated areas could potentially
have a long term impact on the selected remedy for the TWCA Site.
EPA has determined that the combination of remedial actions identified in the
Proposed Plan, and as identified in the Selected Remedy in the ROD, will
reduce or eliminate the risks to human health and the environment in a cost-
effective manner. Costs of the Proposed Plan and the Selected Remedy will be
minimized because groundwater extraction will be mostly from existing
monitoring wells, treatment of groundwater contaminants will be mostly via
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TWCA's existing wastewater treatment system, and pretreatment if required will
be via BPT such as air stripping or carbon adsorption. Air stripping and carbon
adsorption are inexpensive effective technologies.
The TWCA-preferred Alternative 3 does not meet the selection criteria for
remedial alternatives as outlined in the NCP for the following reasons:
1)
Groundwater extraction from only the Feed Makeup and Farm Ponds
areas of the Site will not restore the groundwater aquifer, contain on-Site
contamination, or prevent off-Site migration of contaminants. The TWCA
RifFS offers no explanation as to why only those wells in the Feed
Makeup and Farm Ponds areas were selected, when a number of on-Site
wells exhibit similar characteristics.
2)
Surface water discharge of extracted groundwater without pretreatment
would be in violation of ARARs for the Site.
3)
Contaminated sediments would remain on Site, and continue to pose a
threat to the environment.
For the reasons stated, EPA has determined that TWCA's preferred alternative
would not be tully protective of human health and the environment and would
not be able to comply with federal and state ARARs for the TWCA Site.
28.
COMMENT: TWCA believes that because EPA evaluated a seventh atternative,
not evaluated by TWCA, that EPA has dismissed, without explanation, the
findings in the EPA-approved RifFS. TWCA questions any representation by
EPA that actions contained in Alternative 7 have been analyzed through
consideration of various alternatives in the RifFS.
-
RESPONSE: In reviewing the RifFS, EPA has consistently pointed out data
gaps in the RifFS in letters and meetings with TWCA. EPA communications to
TWCA pointing out these data gaps may be found in the Administrative Record
as part of EPA's comments on the RifFS. Paragraph 31.B. of the
Administrative Order on Consent, EPA Docket No. 1086-02-19-106 (AOC) , in
which TWCA and EPA are co-signatories provides that EPA will make
amendments to the RifFS if EPA deems it necessary. EPA has in essence
amended the RifFS, by including an additional remedial action atternative
(Alternative 7).. The evaluation of an additional alternative (Altemative 7) is not a
dismissal of the findings of the RifFS. Alternative 7 draws on the findings of the
RifFS, incorporates components of Alternative 6 (evaluated in the RifFS), and
includes additional components to correct the data gaps.
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29.
30.
COMMENT: TWCA stated that because the Proposed Plan was not subject to
the rigorous scrutiny as required by the RifFS process, EPA has by-passed the
procedures set forth in the NCP for evaluating remedial alternatives. TWCA
characterized the Proposed Plan as only performing a cursory comparative
analysis of the alternatives using the nine evaluation criteria set forth in the
NCP.
RESPONSE: As stated in Comment 27 above, EPA evaluated Alternative 7
because of concerns that the alternatives evaluated in the TWCA RifFS would
not meet the two threshold criteria of protectiveness and compliance with
ARARs as is required by the NCP. Alternative 7 draws upon Alternatives 4,5
and 6 which were evaluated in the RIjFS. Additional elements such as the
requirement for environmental evaluations were added because of the concern
about the effectiveness of the TWCA-evaluated alternatives. The Proposed Plan
allows implementation of the TWCA-evaluated alternatives in a manner which
would best meet the nine evaluation criteria, including the threshold criteria.
COMMENT: TWCA objected to EPA's refusal to allow additional time for TWCA
to present its views on the Proposed Plan during the September 14, 1993 public
meeting. TWCA stated that EPA did the public a disservice by not allowing
TWCA and its experts to present their findings. As a result, TWCA thinks, the
public was provided with incomplete explanations of the RIjFS process. In
addition, TWCA contended that EPA violated due process and the NCP by not
allowing TWCA and its experts an adequate opportunity to present its findings
and comments concerning the Proposed Plan.
RESPONSE: The NCP at Section 300.430(f)(3) requires EPA to provide a
reasonable opportunity for submission of oral and written comments on the
Proposed Plan. On June 30, 1993, prior to issuance of the Proposed Plan, EPA
officials met with TWCA representatives to explain EPA's rationale for the
proposed Superfund cleanup. At this meeting EPA offered to allow TWCA the
opportunity to present the results of the RIjFS at the public meeting on the
Proposed Plan. EPA issued the Proposed Plan on August 27, 1993. One week
prior to the public meeting, TWCA turned down EPA's offer stating that it did so
because it disagreed with EPA's proposed Alternative 7. TWCA then requested
one hour to oppose the Proposed Plan at the public meeting. EPA turned
down this request because allowing TWCA one-hour time at the public meeting
would potentially deprive other members of the public from having adequate
time to comment on the Proposed Plan. EPA informed TWCA that generally
because of time constraints, and depending on the number of commenters,
each commenter would be limited to five minutes. TWCA would be free to use
any excess time remaining after everyone had equal opportunity to provide
comments. Twenty two commenters presented oral comments at the public
meeting on September 14,1993. Each commenter generally took five minutes
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or less to present his/her comments. However TWCA's legal counsel used
more than twenty minutes to present comments (about four times longer than
any other commenter). EPA expanded the timeframe of the public meeting to
accommodate TWCA's expanded comments. EPA's Response to Comment 8
of this Responsiveness Summary provides more detail on the manner in which
TWCA has been given ample opportunity for comment throughout this process.
31.
COMMENT: TWCA stated that EPA's Proposed Plan conflicts with EPA's
directives and guidance documents, and with the feasibility study findings on
technical practicability of remediating aquifers through groundwater extraction.
TWCA also implied that EPA's assessment is simply unrealistic and contrary to
most other experiences throughout the country.
RESPONSE: TWCA has misinterpreted the EPA guidance on technical
impracticability of remediating groundwater aquifers. This guidance, which is
entitled .Guidance for Evaluating the Technical Impracticability of Ground-Water
Restoration. (Office of Solid Waste and Emergency Response (OSWER)
Directive 9234.2-25), discourages the use of technical impracticability waivers
prior to implementation of full-scale aquifer remediation systems because it is
often difficult to predict the effectiveness of remedies based on limited site
characterization data. Decisions regarding the technical practicability of
groundwater restoration must be based on thorough characterization of the
physical and chemical aspects of the site. Because of data gaps in the TWCA
RI/FS due to the fact that the RI/FS does not characterize areas beneath
buildings and structures, EPA cannot, at this stage, make an accurate
determination on groundwater technical impracticability. Analyses of previously
uninvestigated areas as called for in the Proposed Plan and the Selected
Remedy must be accomplished before the TWCA Site can be considered as
being thoroughly characterized. In addition, as called for in the guidance, the
selected remedy in the ROD utilizes a phased approach for determining whether
groundwater cleanup levels are achievable. The groundwater extraction
element of the Proposed Plan and the selected remedy also conforms to state
of Oregon requirements that groundwater be cleaned up to its most beneficial
use.
TWCA's belief that the groundwater extraction element of the Proposed Plan is
unrealistic and contrary to experience throughout the country is unfounded.
Studies of groundwater extraction systems throughout the country have shown
that groundwater pump and treat systems are effective for containing the
contaminant plume and for reducing the mass of contamination in the aquifer.
The Selected Remedy as outlined in the ROD clarifies the containment
requirement of the groundwater eXtraction element by requiring groundwater
which is above lifetime cancer risk levels of 10"', and/or is significantly above
the noncancer hazard index of 1, to be contained on the TWCA site. The
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Selected Remedy also requires that contaminant masses at groundwater hot
spots or source areas be reduced. EPA has determined that the containment
and mass reduction approach to groundwater remediation at the TWCA site,
which is clarified in the Selected Remedy, is realistic and is consistent with EP A
policy, guidance, and with available experience.
32.
COMMENT: TWCA commented that EPA's Proposed Plan ignores the findings
in the RifFS concerning sediment removal. TWCA also stated that despite the
findings in the RifFS, EPA has considered sediment removal technology without
providing rationale for its decision.
RESPONSE: The TWCA RI/FS states that sediment removal could impact the
existing sediment ecosystem. However, the RifFS does not present data which
confirms or supports this finding. EPA has sound basis for considering
sediment removal. Sediment removal has been selected and conducted at
many Superfund sites around the country, including the Commencement Bay
site in Washington State, with minimal long term impact on ecosystems.
Information on sediment removal drawn from experiences at this site, and other
sites in the United States, is included as part of several technical sources and
guidance documents found in the Administrative Record. Sediment remedial
actions called for in the ROD are designed to minimize impact on the sediment
ecosystem at the TWCA Site.
TWCA Believes EPA Has Applied Its Risk Assessment Guidance Incorrectly
33.
COMMENT: TWCA commented that EPA's application of its risk evaluation
guidance is erroneous and misdirected and has resulted in improper risk
management decisions by EPA. TWCA implied that EPA has ignored the
findings in the risk assessment. For example, the TWCA risk assessment
emphasized that exposure to impacted soil and groundwater at the TWCA
facility is highly unlikely. TWCA also commented that EPA has relied on
unrealistic risk exposure. assumptions to set harsh and unnecessary acceptable
exposure levels given that the facility will continue to be used for industrial
purposes. .
RESPONSE: As stated in the Proposed Plan, throughout the ROD, and in
EPA's Responses to Comments 1 and 5 of of this Responsiveness Summary,
EP A recognizes that TWCA is an active facility with ongoing operations and has
consistently taken those circumstances into account in making determinations.
EPA has relied, for its risk management decisions, upon exposure assumptions
that were developed in the TWCA-RI/FS. These exposure assumptions were
developed by TWCA in accordance with EPA guidelines. For example; the
percent of time that workers would spend in a potentially contaminated area is
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generally less than if the TWCA facility were used for residential purposes, so
that for purposes of characterizing human health risks on the plant site, the
TWCA RIjFS used an approach that is less conservative than if the TWCA
property were used for residential purposes. This less conservative approach
has been incorporated by EP A in its' decision making process for the selected
remedy at the TWCA site, and is further documented in the ROD.
34.
COMMENT: TWCA commented that it believes that EPA risk assessment
guidance does not require remediation when the hypothetical human health risk
is below 10"".
RESPONSE: EPA's risk assessment guidance was developed to ensure that
risk assessments conducted at Superfund sites are in compliance with
requirements of the NCP. Section 300.430(e)(2)(~ of the NCP states that risks
are generally considered acceptable within the 10 and 10-6 range for known or
suspected carcinogens. Although these levels are within the NCP range, these
levels may exceed both federal and Oregon state drinking water standards.
The groundwater extraction element of the Selected Remedy in the ROD has
. been modified from the Proposed Plan to allow for extraction of groundwater at
areas of greater risk and on-Site containment of groundwater with contaminant
risks between 10'" and 1 0-6. This modification of the Proposed Plan is
reasonable because EPA expects that groundwater extraction of areas of higher
risk levels will reduce sources of contamination to other groundwater areas
beneath the TWCA site. Once this is accomplished, natural attenuation of
contamination at the areas of lower risk may be relied upon to achieve the
required cleanup levels. EPA's Responses to Comments 9 through 12 also
addresses this issue in greater detail.
35.
COMMENT: TWCA commented that it believed that institutional control~ were
appropriate for reducing exposure at the plant. TWCA thought that EPA had
ignored the role of institutional controls in eliminating potential exposures to
impacted soils and groundwater in making risk management decisions for the
site.
RESPONSE: EPA agrees with TWCA that in some cases institutional controls
are appropriate for reducing exposures. However, EPA has determined that
institutional controls alone are not adequate for preventing further releases of
contaminants,' for preventing contaminants from migrating to groundwater, or
for preventing contaminants from migrating off Site. Therefore, for institutional
controls to be effective, institutional controls need to be coupled with active
groundwater remediation. -
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36.
COMMENT: TWCA stated that EPA's Proposed Plan would require installation
of an extensive groundwater extraction system, sediment removal, and soil
removal throughout the plant site. TWCA believed that the basis for those
requirements are not supported by the Administrative Record. .
RESPONSE: TWCA's RifFS and the Administrative Record support the
requirement for installation of a groundwater extraction system, and for
sediment removal. The Proposed Plan recommended implementation of a
modification of the TWCA evaluated groundwater extraction alternative
(Alternative 6). This modification did not require installation of additional
monitoring wells beyond those 36 wells already evaluated in the RifFS. In
addition, the Proposed Plan recommended removal of only 3,600 cubic yards of
sediment, which is 1,500 cubic yards less than evaluated under Alternative 6 in
the TWCA RifFS.
The TWCA RifFS contained several data gaps with respect to delineation of the
nature and extent of contamination in soil and evaluation of soil remediation
options at the Site. Because of the necessity to address these data gaps in the
RifFS, the RifFS will be amended subsequent to this ROD and Responsiveness
Summary. The amended RifFS will include an evaluation of soil cleanup
options, including soil removal. Upon completion of the amended RifFS, and
after a public comment period, EPA will document the selected soil cteanup
remedy in a subsequent ROD for Operable Unit Three.
TWCA Believes The Community Strongly Opposes EPA's Proposed Plan
37.
COMMENT: TWCA stated that based on the public hearing and written
submissions presented to EPA, the communities of Albany and Millersburg are
strongly opposed to the perceived overreaching of EPA's proposal. TWCA
stated that members of these communities believed that EPA's Proposed Plan
was overreaching because it was excessive in the stringency of its cleanup
standards and environmentally unnecessary. TWCA also summarized other
concerns of members of the community, including community leaders, elected.
officials, business leaders, local media experts, TWCA employees, and
interested residents. These concerns as expressed by Teledyne, included the
potential negative impact of the Superfund cleanup on TWCA and, in time, on
the area's economy. Similarly, TWCA stated that local doctors questioned the
appropriateness of the risk assumptions relied upon by EPA and stressed the
relationship between employment and good health.
RESPONSE: EPA shares the concerns of the community in striking an
appropriate balance between protectiveness of public health and the
environment and cleanup standards that may be unnecessarily burdensome.
EPA believes the appropriate balance has been reached in the Selected
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Remedy which takes into account community concerns. The Proposed Plan is
based upon site-specific conditions as described in TWCA's RI/FS. However,
the selected remedy as described in the ROD, has been modified in response
to public comment. The selected remedy differs from the Proposed Plan as a
logical outgrowth of comments received from the community.
EPA's response to comments from the community, reflecting how community
concerns were addressed, are summarized in Section 3 of this Responsiveness
. Summary.
Because TWCA Is An Active Operating Facility Subject to RCRA, TWCA Believes
The Plant Should No Longer Be Regulated Under CERCLA
38.
COMMENT: TWCA commented that it is inappropriate for EPA to use its
CERCLA authority to regulate ongoing operations; rather, TWCA believed its
facility would be more appropriately handled under the RCRA regulatory
programs of EPA and DEO. TWCA further expressed that, based on EPA's
Proposed Plan, TWCA is potentially subject to unnecessary, duplicative, and
inconsistent oversight by both the RCRA and CERCLA programs of EPA and
DEO. TWCA also contended that EPA's Proposed Plan is a method for closing
the TWCA facility now. For example, EPA's proposal calls for source reduction
techniques and an environmental evaluation of soils and groundwater beneath
those areas when TWCA changes or discontinues use of any pond, area,
building, or structure. TWCA believed that those requirements as part of the
CERCLA action could impact adversely on its ongoing operations.
RESPONSE: The regulations under the Resource Recovery and Conservation
Act, 42 U.S.C. 6901 (RCRA) authorities have historically not been extensively
applied by federal or state agencies to regulate the TWCA facility. TWCA has
been regulated under the CERCLA authorities because the facility has been
placed on the NPL due to past releases of hazardous substances into the
environment. EPA has been coordinating with DEO RCRA and CERCLA
programs to ensure that duplication of effort is minimized. EPA's Response to
Comment 6 in this Responsiveness Summary also addresses this issue in
greater detail.
EPA's Proposed Plan and Selected Remedy are designed so as to have
minimal impact on TWCA's ongoing operations. EPA's Proposed Plan and
Selected Remedy allow TWCA the flexibility for determining when environmental
evaluations could be integrated into its conduct of its business operations.
Source reduction techniques would not be required unless releases of
contaminants into the environment from TWCA's ongoing operations impact the
effectiveness of the Superfund clean up. EPA's Response to Comment 1 in this
Responsiveness Summary also addresses this issue in greater detail.
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39.
COMMENT: TWCA commented that the TWCA Site should no longer be listed
on the NPL, based on the EPA's deferral policy, since TWCA's actions to date
have resulted in removal of environmental media of greatest concern. TWCA
further stated that it does not fall within any categories justifying its listing on the
NPL. First, there is no evidence of TWCA's inability or willingness to finance or
perform the work. Secondly, TWCA has cooperated fully with the agencies in
working through any RCRA issues, despite what TWCA considered conflicting
directions from EPA and DEO concerning the RCRA permitting requirements.
RESPONSE: Although EPA acknowledges that TWCA has already undertaken
significant cleanup action at the Site, EPA has determined, based on the results
of the TWCA RifFS, that groundwater is contaminated beneath the Site which
poses a potential threat to human health and the environment. In addition,
sediment contamination on and in the vicinity of the Site may pose a threat to
aquatic life. Based on these findings, EPA must require that cleanup actions be
taken at the Site under CERCLA authorities. As stated in Comment 38, the
requirements under RCRA have historically not been extensively applied by
federal or state agencies to regulate the TWCA facility. EPA will ensure that
there will be coordination between the CERCLA and RCRA programs with
respect to environmental cleanup actions at the TWCA facility.
TWCA Believes That EPA Has Failed to Articulate a Rationale for Its Proposed
Plan.
40.
COMMENT: TWCA commented that it believed that the Proposed Plan is
devoid of any rationale for EPA's selection of an entirely new alternative not
considered during the preparation of the RifFS. Furthermore, TWCA felt that
many components of EPA's proposal are too vague to be understood. TWCA
felt that the September 14th public meeting and the October 22nd Fact_Sheet
did not adequately explain why EPA felt it was necessary to consider a new
alternative. TWCA believed that the distinctions and reasons for those
distinctions between EPA's alternative and the alternatives considered in the
RifFS were not clearly established.
It was TWCA's perception that the Fact Sheet only set forth rationale for the
requirement that TWCA perform sampling when use of any buildings and
structures is discontinued. TWCA believed that the Fact Sheet did not address
other aspects.of EPA's Proposed Plan, such as source reduction or potential
conflicts between EPA's CERCLA and RCRA authorities under the proposal.
RESPONSE: Rationale for devefoping an additional alternative is clearly
presented in the Administrative Record and was presented to TWCA via
numerous comment letters and conference calls regarding the RifFS prior to
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issuance of the Proposed Plan. EPA has specifically outlined data gaps and
deficiencies in the TWCA RI/FS in letters from EPA to TWCA dated
December 18, 1992, May 21, 1993, and July 16, 1993. Those EPAjTWCA
communications are part of the Administrative Record. As specified in those
previous communications, the TWCA RI/FS did not address several major areas
potentially effected by releases of hazardous substances from the Site. These
unaddressed areas include; (1) current potential off-Site groundwater and
surface water (Le. Willamette River) contamination as a result of releases from
the Site, and, (2) on-Site operating process/waste management areas which
may have previously contaminated or may be continuing to contribute to
contamination of groundwater and surface water at the Site. Alternative 7
utilizes elements of alternatives evaluated by TWCA in the RI/FS while
addressing concerns regarding implementation and effectiveness of the TWCA-
evaluated alternatives. These concerns were presented to the public in the
Proposed Plan and at the public meeting held in Albany on September 14,
1993.
As discussed further in EPA's Response to Comment 38 in this Responsiveness
Summary, EPA has been coordinating with RCRA and CERCLA authorities to
ensure that conflicts between the two regulatory programs do not occur with
respect to the cleanup of the TWCA facility.
41.
COMMENT: TWCA commented that it did not believe that EPA, in proposing
.,.Iternative 7, fully evaluated the remedies based on available data and the
findings of the RI/FS. TWCA thought that by developing and proposing
Alternative 7, EPA was acting arbitrarily and capriciously. TWCA thought that
EPA gave post-hoc rationalizations and explanations and that these could not
supplant the RifFS process.
RESPONSE: EPA has conformed with the RI/FS process in accordan~ with
CERCLA, the NCP, and with the AOC. EPA amended the RI/FS and developed
Alternative 7 to fill the data gaps apparent regarding implementation of the
alternatives evaluated in the TWCA RifFS. In its comments to TWCA on the
RI/FS, EPA has, in letters to TWCA and conference calls with TWCA
representatives, consistently identified the data gaps in the RI/FS prior to
issuance of the Proposed Plan. EPA's communications with TWCA on this
issue may be found in EPA's comments on the RI/FS in the Administrative
Record. TWCA has failed to correct those data gaps. As stated in EPA's July
16, 1993 letter. to TWCA regarding the RI/FS, "to th.e extent that those data
gaps impact the design effectiveness of proposed Superfund remedial actions
for the Site, EPA believes that it is important, at this stage in the process
towards Superfund remedial action, to emphasize that the data gaps must be
bddressed during the proposed Superfund remedial action. To adequately
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protect human health and tho environment. F:PA ~\Jrnmonly requires PRPs to
address some data gaps during the RD IRA process. N
TWCA Believes The Proposed Plan is Based on a Misapplication of Oregon.s
Remedial Action Regulations.
42.
COMMENT: TWCA commented that Oregon law on background
concentrations is not an applicable and relevant or appropriate requirement
(ARAR) for the plant. TWCA contended that the Oregon State Background
Standard does not satisfy the requirements for an ARAR and; therefore. should
not be applied to TWCA.
RESPONSE: Section 300.5 of the NCP defines apDlicable requirements as
"those cleanup standards, standards of control, and other substantive
requirements, criteria, or limitations promulgated under federal environmental or
state environmental or facility siting laws that specifically address a hazardous
substance, pollutant, contaminant, remedial action, location, or other
circumstance found at a CERCLA site. Only those standards that are identified
by the state in a timely manner and that are more stringent than federal
requirements may be applicable. N The Oregon Environmental Cleanup Rules
(OAR 340-122-010 through 340-122-360) are substantive requirements that are
applied to all CERCLA hazardous waste sites in the State of Oregon. For each
site the technical and economic feasibility of cleanup of environmental media to
background is evaluated. If it is determined that cleanup to background is not
feasible, then an evaluation is performed to determine the lowest feasible
cleanup concentrations. In all cases the level of cleanup must be protective of
human health and the environment. The result of this process is a cleanup level
or action(s) that is applied to the site. EPA will make the determination as to
whether the Oregon State Background Standard is applicable to soil cleanup
actions at the TWCA Site in a subsequent soils operable unit ROD.
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