SIXTH FIVE-YEAR REVIEW REPORT FOR
WESTERN PROCESSING CO., INC. SUPFRFUND SITE
KING COUNTY, W ASHINGTON
" 'Vy
pROtt
Prepared by
U.S. Environmental Protection Agency
Region 10
Seattle, Washington
Mion I Uilhri \. Dii ci-iiH' Datr
Office of Environmental Cleanup
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Table of Contents
LIST 01 ABBREVIATIONS & ACRONYMS 3
I. INTRODUCTION 4
Site Background 4
FIVE-YEAR REVIEW SUMMARY FORM 5
II. RESPONSE ACTION SUMMARY 7
Basis for Taking Action 7
Response Actions 7
Status of Implementation 11
Institutional Control Summary 13
Systems Operations/Operation and Maintenance (O&M) 16
III. PROGRESS SINCE THE PREVIOUS REVIEW 16
IV. FIVE-YEAR REVIEW PROCESS 18
Community Notification, Community Involvement and Site Interviews 18
Data Review 19
Site Inspection 26
V. TECHNICAL ASSESSMENT 26
QUESTION A: Is the remedy functioning as intended by the decision documents? 26
QUESTION B: Are the exposure assumptions, toxicity data, cleanup levels and RAOs used at the time of the
remedy selection still valid? 27
QUESTION C: Has any other information come to light that could call into question the protectiveness of the
remedy? 28
VI. ISSUES/RECOMMENDATIONS 28
VII. PROTECTIVENESS STATEMENT 29
VIII. NEXT REVIEW 30
APPENDIX A - REFERENCE LIST A-l
APPENDIX B - SITE CHRONOLOGY B-l
APPENDIX C - SITE MAPS C-l
APPENDIX D - PRESS NOTICE D-l
APPENDIX E - INTERVIEW FORMS E-l
APPENDIX F - SITE INSPECTION CHECKLIST F-l
APPENDIX G - SITE INSPECTION PHOTOS G-l
APPENDIX H - DETAILED REMEDIAL BACKGROUND 11-1
APPENDIX I - DETAILED DATA ANALYSIS 1-1
APPENDIX J - DETAILED ARARs REVIEW TABLES J-l
APPENDIX K - SCREENING-LEVEL RISK REVIEW K-l
APPENDIX L - ANNUAL PROPERTY NOTICE EXAMPLES l.-l
Tables
Table 1: Indicator Chemicals for Water 10
Table 2: Summary of Planned Institutional Controls (ICs) 13
Table 3: Protectiveness Determinations/Statements from the 2013 FYR and 2015 FYR Addendum 17
Table 4: Status of Recommendations from the 2013 FYR and 2015 FYR Addendum 18
Table 5: Monitoring Wells with CAC Exceedances, 2013 to March 2018 22
Table 6: Estimated Contaminant Mass Removed by Groundwater Extraction, 2013 to 2017* 24
Table B-l: Site Chronology B-l
Table 1-1: Groundwater Elevations (ft., MSL) 1-8
Table 1-2: Annual Vinyl Chloride Emissions, 2013 to 2017 1-10
Table J-l: Groundwater ARARs J-l
Table J-2: Surface Water ARAR J-2
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Table K-l: Review of Soil Excavation Levels - Human Health Direct Contact K-l
Table K-2: Risk Evaluation of Human Health-based Groundwater CACs K-2
Table K-3: Screening-level Risk Evaluation of Soil Cleanup Goals - Industrial Scenario K-3
Figures
Figure 1: Site Vicinity Map 6
Figure 2: Institutional Control Map 15
Figure 3: Detailed Site Map 25
Figure C-l: Well and Piezometer Locations (Landau Associates, 2016 Annual Report) C-l
Figure C-2: Groundwater Extraction System (Landau Associates, 2016 Annual Report) C-2
Figure 1-1: Average Groundwater Elevation in Sector 1 1-1
Figure 1-2: Annual Gallons of Groundwater Extracted 1-2
Figure 1-3: Well 5M4A Historical Levels of HPMO, OPMO 1-3
Figure 1-4: Well 5M4A Historical Levels of cis-l,2-DCE and Vinyl Chloride from 2017 Annual Report 1-4
Figure 1-5: Well 9M44A Historical Levels of Vinyl Chloride and Zinc SAR Qad 1 Chloride and Zinc 1-5
Figure 1-6: Well 9M9B Historical Levels of cis-l,2-DCE and Vinyl Chloride 1-6
Figure 1-7: Well N3B Historical Levels of Total Zinc 1-7
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LIST OF ABBREVIATIONS & ACRONYMS
1,1,1 -T CA 1,1,1 -T richloroethane
ADI Acceptable Daily Intakes
ARAR Applicable or Relevant and Appropriate Requirement
AWQC Federal Ambient Water Quality Criteria
bgs Below Ground Surface
CAC Contingent Action Criteria
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act
cis-1,2-DCE Cis-1,2-dichloroethylene
CFR Code of Federal Regulations
COC Contaminant of Concern
1,2-DCE 1,2-Dichloroethylene
Ecology Washington Department of Ecology
EPA United States Environmental Protection Agency
ESD Explanation of Significant Differences
FFS Focused Feasibility Study
FS Feasibility Study
FYR Five-Year Review
HPMO 3-(2-hydroxypropyl)-5-methyl-2-oxazolidinone
HQ Hazard Quotient
IC Institutional Control
KCIWD King County Industrial Waste Division
KPEG Potassium hydroxide, polyethylene glycol
(ig/L Microgram per Liter
mg/kg Milligram per kilogram
MCL Maximum Contaminant Level
MNA Monitored Natural Attenuation
MSL Mean Sea Level
NCP National Contingency Plan
NPL National Priorities List
O&M Operation and Maintenance
OU Operable Unit
OPMO 3-(2-oxypropyl)-5-methyl-2-oxazolidinone
PAH Polycyclic Aromatic Hydrocarbon
PCB Polychlorinated Biphenyl
PCE Tetrachloroethylene
PLC Programmable logic control
POTW Publicly-Owned Treatment Works
PPA Prospective Purchaser Agreement
PRP Potentially Responsible Party
RAO Remedial Action Objective
RCRA Resource Conservation and Recovery Act
RI Remedial Investigation
ROD Record of Decision
RODA Record of Decision Amendment
RPM Remedial Project Manager
RSL Regional Screening Level
SVOC Semi-Volatile Organic Compound
TCE Trichloroethylene
TPH Total petroleum hydrocarbons
trans-1,2-DCE Trans-1,2-dichloroethylene
UU/UE Unlimited Use/Unrestricted Exposure
VOC Volatile Organic Compound
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I. INTRODUCTION
The purpose of a five-year review (FYR) is to evaluate the implementation and performance of a remedy to
determine if the remedy is and will continue to be protective of human health and the environment. The methods,
findings and conclusions of reviews are documented in FYR reports such as this one. In addition, FYR reports
identify issues found during the review, if any, and document recommendations to address them.
The U.S. Environmental Protection Agency (EPA) is preparing this FYR pursuant to the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA) Section 121, consistent with the National
Contingency Plan (NCP) (40 Code of Federal Regulations (CFR) Section 300.430(f)(4)(ii)), and considering EPA
policy.
This is the sixth FYR for the Western Processing Co., Inc. Superfund site (the Site). The triggering action for this
policy review is the completion date of the previous FYR. The FYR has been prepared because hazardous
substances, pollutants or contaminants remain at the Site above levels that allow for unlimited use and
unrestricted exposure (UU/UE).
The Site consists of three operable units (OUs). This FYR addresses all three OUs. OU1 addresses surface
cleanup. OU2 addresses the containment portion of the remedy. OU3 addresses the East Drain and Mill Creek
portions of the cleanup. OU1 is considered Phase 1 of the cleanup. OU2 and OU3 are considered Phase 2 of the
cleanup1.
EPA remedial project manager (RPM) Piper Peterson led the FYR. Participants included EPA Region 10
hydrologist Bernie Zavala, Ching-Pi Wang from the Washington Department of Ecology (Ecology), and Treat
Suomi and Sarah Alfano from Skeo (EPA FYR support contractor). The Boeing Company (Boeing), one of the
Site's potentially responsible parties (PRPs) and Corporate Trustee for the Western Processing Trust Fund (Trust),
was notified of the initiation of the FYR. The review began on 10/5/2017.
Site Background
The 14-acre Site is in an industrial and commercial area about 2 miles north of the city center of Kent,
Washington, in the Kent Green River Valley (See Figure 1). The Western Processing Company operated on site
from 1961 to 1983. The company originally reprocessed animal byproducts and brewer's yeast. The facility
expanded in the 1960s to include recycling, reclaiming, treatment and disposal of industrial wastes. Site
operations contaminated soil, groundwater and sediment with hazardous chemicals. In 1983, a federal court order
permanently shut down the company's operations.
The area just north of the Site is undeveloped. East of the Site lies the Interurban Trail. This recreational trail runs
parallel to a rail line and a railroad drainage ditch (the East Drain). The area south of the Site has been developed
for light industrial uses. Land uses west of the Site are mostly commercial. The Site is zoned for industrial uses
and is not currently in use beyond a new public roadway that crosses over part of the Site, remediation and an
office/storage building. The Site's remedial components are considered in four sectors. Sector 1 includes the cap
and extraction system within the southern slurry wall. Sector 2 includes the extraction system immediately
southwest of Sector 1. Sector 3 includes the Trans Plume Area2 and its accompanying extraction system of three
wells. Sector 4 includes the final extraction system, located within the northern slurry wall (Figure 2).
1 Site records differ regarding the number of OUs. This report considers that there are three OUs to maintain consistency with
tracking in the EPA system.
2 Early investigations indicated that there was 1,2-dichloroethylene present in an off-site plume west of the Site and that the
trans isomer was present. However, more precise analytical techniques subsequently identified the 1,2-dichloroethylene
present as primarily the cis isomer. Although low concentrations of the trans isomer were present in some areas of the Site,
none is detectable west of the Site. Nevertheless, common usage throughout the Site's history has continued to reference the
"trans plume" relative to the former dissolved volatile organic compound (VOC) plume west of the Site.
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Mill Creek lies just outside of the western boundary of the Site ond flows in a northerly direction into the Black
River, a tributary of the Green River. The Green River flows into the Duwaniish River before ultimately emptying
into the Puget Sound. The Site is underlain by an alluvial shallow aquifer comprised of zones A. B and the
deepest zone. C. Site operations contaminated Zone A and B groundwater, which flow to the northwest. Zone A
groundwater generally discharges into Mill Creek and Zone B groundwater flows midci the creek. Zone A and B
flow are currently affected by groundwater extraction at the site.
Public drinking water is provided by the city of Kent from a deep, hydraulic ally isolated artesian aquifer more
than a mile southeast (hydraulically upgradient) from the Site. There are no wells currently used for drinking
water in rhe shallow aquifer within a mile radius of rhe Site. Appendix A lists additional resources used in
preparation of this FYR Report. Appendix B provides the Site's chronology of events.
FIVE-YEAR REVIEW SUMMARY FORM
SITE IDENTIFIC ATION
Site Name; Western Processing Co., Inc.
EPA ID: WAD009487513
Citv Couutv: Kent King
Multiple OUs?
Yes
Has the Site achieved construction completion?
Yes
Lead agency: EPA
Author name: Piper Peterson, with additional support provided by Skeo
Author affiliation: EPA Region 10
Review period: 10 5 201" -9 2" 2018
Date of site inspection: 1 9 20 i 8
Type of review: Policy
Review number: 6
Triggering action date: 9 2". 201?
Due date (fiveyears after triggering action date): 9 2" 20IS
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Figure 1: Site Vicinity Map
0 500 1,000 2,000
Feet
Sources: 2016 Annual Report Figure 1-2, 2000 Site Cap
Operation and Maintenance Plan, Figure 3, Esri, DeLorme,
AND, Tele Atlas, First American, UNEP-WCMC,
DigitalGlobe, GeoEye, Earthstar Geographies, CNES/Airbus
DS, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP,
swisstopo and the GIS User Community.
Legend
Superfund Site Sector Boundaries
7ZA RCRA Cap
-¦¦¦• East Drain
...J
^Skeo O
V ~ NORTH
Western Processing Co., Inc. Superfund Site
City of Kent, King County, Washington
Disclaimer This map and any boundary lines within the map are approximate and subject to change. The map is not a survey. The map is for informational
purposes only regarding EPA"s response actions at the Sitfc
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II. RESPONSE ACTION SUMMARY
Basis for Taking Action
EPA inspected the facility in March 1981. By August 1982, EPA had ordered the site owners/operators to
investigate contamination in soil, surface water and groundwater. When the owners/operators did not comply,
EPA undertook the investigation in September 1982.
EPA's phased remedial investigation/feasibility study (RI/FS) work, which began during summer 1983 and
proceeded at the same time as the surface cleanup (Phase 1, discussed in the next section), found over 90 of
EPA's 126 priority pollutants in soil, groundwater, and surface water; heavy metals, polychlorinated biphenyls
(PCBs), phenols and volatile organic compounds (VOCs) were the predominant contaminants. Most of the
contamination was determined to be contained within the uppermost 15 feet of soil. Groundwater contamination
was mostly concentrated from the water table to about 30 feet below ground surface (bgs), within Zone A.
The RI/FS identified high concentrations of metals in on-site soils and off-site soil. Site investigations found
contaminants in the Zone A aquifer had migrated into Mill Creek prior to the installation of a slurry wall, and the
contaminants in Zone B had been transported beneath Mill Creek and downgradient of the Site into an area
known as the Trans Plume Area. Zone C was not impacted by site contamination. The 1985 FS identified
unacceptable risk to future on-site workers and unacceptable risk from future use of on-site groundwater as a
potable source (see Appendix H for additional background).
The Site's 1985 Record of Decision (ROD) noted that organic pollutant contamination in Mill Creek did not
appear to pose a threat to human health based on recreational use. The water in Mill Creek near and downstream
of the Site was evaluated for aquatic organisms, which were found in limited supply. Concentrations of dissolved
metals, including zinc, cadmium, copper, and chromium, were found to exceed ambient water quality criteria for
the protection of freshwater aquatic organisms. Sediments in Mill Creek were also contaminated with metals.
Concentrations of organic contaminants in Mill Creek did not exceed ambient water quality criteria for the
protection of freshwater aquatic organisms.
Response Actions
EPA conducted a removal action to stabilize the Site; it began in late April 1983 and finished in July 1983.
Cleanup included the removal and off-site disposal of solidified paint sludges/flammables, flammable liquids in
bulk and drums, combustible liquids in bulk, recycled solvents, corrosive liquids in bulk and drums, non-corrosive
oxidizers in drums, PCB liquids and PCB-contaminated materials, and pond wastewater. EPA listed the Site on
the Superfund program's National Priorities List (NPL) in September 1983. Using state funds, Ecology
implemented stormwater control measures at the Site in the fall of 1983. PRP and EPA investigations,
summarized in focused feasibility studies (FFSs) in 1984, suggested site remedial techniques focus on source
control and containment measures.
OU1 - Surface Cleanup
EPA issued the Site's first ROD for OU1, or Phase 1 of cleanup, in August 1984 for surface cleanup and
stormwater control. The remedial action objectives (RAOs) for the surface cleanup project include:
• Eliminate or reduce the threat of release of additional hazardous substances into the surface water,
groundwater, soils and the air.
• Prevent or eliminate direct contact hazards for the people who must go on the Site for remedial
investigation and site surveillance activities, and for potential fire or emergency response actions.
• Allow the design and implementation of additional and more wide-ranging and effective stormwater
control to reduce the release of hazardous substances into the ground and surface water.
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• Prepare the surface of the Site during this construction season so that the subsequent remedial actions on
the Site can begin earlier and possibly be completed during the next construction season.
The 1984 ROD selected the following remedy for OU1:
• On-site and perimeter monitoring of air quality during remedial activities.
• Removal and proper disposal of liquids, waste piles, transformers and substation equipment, buildings,
bulk storage tanks and surface debris.
• Stormwater control and treatment prior to discharge before, during and after the surface cleanup.
• Setup and operation of an on-site treatment plant after initial pond removal.
• Removal of each solid waste pile down to the existing grade level except for the gypsum sludge pond,
which the State had excavated during stormwater management efforts. Removal of up to 750 cubic yards
of soil below existing grade level in addition to the pile itself, with the depression forming a stormwater
accumulation area for use after the surface cleanup. Grading of adjacent areas to the south to provide
drainage to this area.
OU2 - Containment Components (slurry wall, groundwater treatment, cap and VOC plume) and OU3 -
Remedial Components Related to Mill Creek and the East Drain
Following Phase 1 of cleanup, EPA issued the Site's second ROD for Phase 2 (OU2 and OU3) in September 1985
to address contaminated soil, buried waste, groundwater, Mill Creek and East Drain contamination, surface water
and sediments. RAOs for the Phase 2 cleanup project, as stated in the Site's 1986 Consent Decree, include:
• Prevent direct human contact with or ingestion of contaminated soils either on or off site.
• Prevent the further spread of and, if possible, removal of the contamination from the shallow aquifer.
• Prevent further contaminant discharges (via groundwater) to Mill Creek at levels that are harmful to
aquatic organisms.
• Control contaminated stormwater runoff from the Site.
EPA updated the 1985 ROD with a ROD Amendment (RODA) in September 1986. The final remedy for OU2
included these components related to soil and groundwater as designated by the 1985 ROD and revised by the
1986 RODA:
• On- and off-site soil sampling and analysis to determine extent of contamination, followed by excavation
and off-site disposal of highly contaminated subsurface wastes.
• Excavation or covering and capping of all remaining contaminated soils outside the Western Processing
Company property that are above background (i.e., the 1 x 10"5 excess cancer risk level) with bench-scale
tests of soil solidification techniques.
• Excavation or cleaning and plugging of all impacted utility and process lines.
• Construction, operation and maintenance of a stormwater control system, maintenance of cover/caps, and
excavation of utility manholes/vaults near the Site.
• Removal or decontamination of a lead-contaminated house.
• Performance of supplemental remedial planning studies if shallow groundwater contamination beyond the
currently contaminated zones or significant regional contamination is detected.
• Construction and operation of a groundwater extraction system and treatment for Zone A (shallow)
groundwater.
• Construction and operation of a groundwater extraction and treatment system for the trans plume in Zone
B (deep) groundwater. Containment pumping and treatment of extracted groundwater from the Trans
Plume Area.
These elements were implemented, with other elements either altered or included as part of the updated remedy
required by the Site's 1995 Explanation of Significant Differences (ESD). The ESD addressed the need for hot
spot remediation, a slurry wall, and the change from mass removal pumping to containment pumping. The rest of
the final remedy included:
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• Construction of a Resource Conservation and Recovery Act (RCRA)-consistent cap over Area 1 (the area
southwest of Mill Creek in Parcel A) (see Figure 2) after removal of the original remedy's extraction and
treatment system.
• Installation of a 40-foot-deep, 4,400-foot-long slurry wall and construction of an isolation wall parallel to
South 196th Street.3
• Operation of a new containment pumping and treatment system for extracted groundwater inside the
slurry wall.
• Implementation of institutional controls to protect the cap and slurry wall and limit groundwater usage on
site and in the immediate area.
• Hot-spot remediation of targeted areas using bioremediation, thermal desorption and stabilization
techniques.
• Site maintenance and groundwater monitoring for 30 years after cap installation unless the timeframe is
modified.
• Development of a contingency plan for mitigating potential releases from the Site if containment pumping
is not effective.
The final remedy for OU3 included these components related to Mill Creek and the East Drain:
• Monitoring of Mill Creek and the East Drain.
• Excavation of contaminated Mill Creek and East Drain sediments, along with additional actions for
remediation as needed.
• Attainment of the Mill Creek performance standard, identified as the ambient water quality criteria for
aquatic organisms or the upstream background, and excavation of contaminated Mill Creek sediments.
• Extensive monitoring of Mill Creek and the East Drain.
• Long-term surface water monitoring for 30 years after cap construction unless the timeframe is modified.
The 1986 Consent Decree specified performance standards for Mill Creek surface water be evaluated against the
freshwater Federal Ambient Water Quality Criterion (AWQC) for Aquatic Organisms. Freshwater chronic
AWQC are available only for site-related metals. No relevant AWQC for site VOCs were available at the time of
the adoption of the Consent Decree and there are still no freshwater chronic AWQC for VOCs. For Mill Creek,
current monitoring includes the following contaminants: cadmium, zinc, chromium, lead, copper and nickel (the
metals of primary interest are zinc and cadmium but surface water monitoring stations are sampled for all metals).
For the East Drain, the list of contaminants has been reduced to zinc and cadmium.
The 1986 Consent Decree required that groundwater be remediated for several metals and base neutral/acid
extractables, and all volatile organic priority pollutants according to 40 C.F.R. § 264.122.4 After years of
monitoring, EPA approved the reduction of the targeted list of contaminants to the indicator chemicals listed in
Table 1.
3 According to the 2013 FYR Report, the slurry wall is a field modification that supplemented the remedial action described
in the 1985 ROD and the AROD.
4 https://www.epa.gov/sites/production/files/2015-09/documents/prioritv-pollutant-list-epa.pdf
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Table 1: Indicator Chemicals for Water
i til' 11 ! Eitl; 1! % !liU']'i."-i
VOt
< fI iumdv. l i-i"
NK'diii Miiititoivt
!.:isi IM'.-iin
^ ;IH'I
Mill i i i't'L
MllT.M'r
\\ iitci-
Benzene
X
-
~
ChloioheiLzene
X
--
...
Chloroform
X
-
...
1.2-Didilorobenzene
X
~
-
1.1 -Dicliloroethylene (1,2-DCE)
X
-
-
1. 1-Dichloioetliane
X
-
--
Cis-1.2-dichloroethylene b (cis-1,2-DCE)
X
—
—
Trans-1.2 -dicliloroethylene * (trans-1,2-
DCE)
X
—
—
Ethylbenzene
X
-
--
Methylene chloride
X
--
—
Styreue
X
--
--
T etrncliloroethylene (PCE)
X
-
--
Toluene
X
-
..
1.1.1 -Trichloroethane (1.1,1-TCA)
X
--
-
Tricliloroethylene (TCE)
X
--
-
Vinyl chloride b
X
-
-
O-xylene
X
--
~
M. p-xylene
X
—
—
Ml 1 \l s
Cadmium
X
X
X
Zinc
X
X
X
Copper
X
X
Chromium
X
X
Nickel
X
X
Lead
X
X
<>\ \/(M IHINOM'.s
5-(2-hydroxypropyb-5-methyl-2-
ox a z o hd iuoue (HPM O)
X
—
—
5-i 2 -oxypropyDo -methyl-2 -
oxazolidisione (OPMO t
X
—
—
Notes:
a. The RODA. winch documents the Consent Decree referencing the OU2 and OU5 remedies, refers to
an off-site plume of trans-1.2-WE located west of the Site (see remedy requirements in the Response
Actions section of this FYR). The results of investigations prior to the Consent Decree indicated that
the 1.2-DCE present was the trans isomer. However, more precise analytical techniques later
identified the 1,2-DCE present as primarily the cis isomer. Although low concentrations of the trans
isomer were present in some areas of the Site, none is detectable west of the Site.
b. The 1995 ESD noted that eis-l,2-DCE concentrations were decreasing in die Trans Plume Area while
vinyl chloride concentrations were generally increasing or staying the same, 1,2-DCE will faiodearade
to vinyl chloride. The ESD stated that it would not designate vinyl chloride standards at that time but
indicated they could be implemented in the future. Monitoring for vinyl chloride is ongoing,
— There are 110 federal AWQC for these constituents, so tliey are not sampled in the East Drain or Mill
Creek,
Mill Creek performance standards were set in the 1985 Consent Decree, which documents the OU2 and OU3
remedies. Surface water quality goals, for Mill Creek are the federal AWQC or background-derived concentrations
where upstream concentrations approach or exceed tlie AWQC.
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There are no site-wide cleanup standards for groundwater contaminants. The only contaminant cleanup standard
established in the RODA required a cleanup level of 70 micrograms per liter ((.ig/L) for the cis-l,2-DCE off-site
plume. Current groundwater monitoring is conducted according to contingent action criteria (CACs), which are
based on the historical concentrations at individual wells or sampling locations per contaminant. CACs are listed
in Table 5 in the Data Review section. The site decision documents did not select chemical-specific Applicable or
Relevant and Appropriate Requirements (ARARs) as performance objectives for the remedy to achieve. Instead,
they developed site-, well- and contaminant-specific CACs, which are based on the historical concentrations at
individual wells or sampling locations per contaminant and not based on maximum contaminant levels (MCLs).
Status of Implementation
OU1 - Surface Cleanup
Under an August 1984 Consent Decree, a group of over 190 PRPs referred to as the Western Processing Trust
Fund (Trust) undertook the surface cleanup designated as Phase I (the OU1 cleanup). Over 2,400 truckloads of
chemical waste and contaminated soil and debris were removed from the Site, primarily in Sector 1. Once all
surface structures (buildings, tanks, impoundments and waste piles) were cleared from the Site, the Site was
graded to prevent stormwater runoff, a temporary lined pond was constructed to contain collected stormwater, and
a portable treatment plant was brought on site to treat the collected water.
The Phase 1 surface cleanup finished in November 1984, except for a storage tank containing oily liquid
contaminated with dioxins. In 1986, the Trust successfully treated about 6,000 gallons of the liquid on site with
the KPEG (potassium hydroxide, polyethylene glycol) mobile chemical dechlorination process. Residual material
from the treatment process was shipped off site. No other materials contaminated with dioxins were found on site.
OU2 - Containment Components (slurry wall, groundwater treatment, cap and VOC plume) and OU3 -
Remedial Components Related to Mill Creek and the East Drain5
Subsurface
Phase 2 construction activities began in 1987. They included extensive testing to determine the limits of
excavation of on-site subsurface wastes and off-site contaminated soils, excavation and Class 1 RCRA landfill
disposal of over 25,000 cubic yards of highly contaminated soil and sludge as well as installation of the original
groundwater extraction and treatment systems. The Trust completed work on the placement of a RCRA cap over
Sector 1 (Figure 2) in 1999.
Groundwater
Groundwater extraction and treatment began in October 1988. As remediation progressed, and in compliance with
the ESD, many old wells, piezometers, vacuum extraction wells and infiltration lines were decommissioned. The
initial groundwater extraction and treatment system was decommissioned in 1996 and a new main extraction and
treatment system was completed to provide automated operation of hydraulic containment in 1997. The treatment
system provided air stripping for VOCs, and adsorption of the VOCs from the air stripper off-gas with activated
carbon. It added new extraction wells in Sector 1 (wells S-l through S-15). Two extraction wells (U1 and U2)
were installed in Sector 2 (directly west of Sector 1 and outside the slurry wall). The new system also added two
extraction wells in Sector 4 (wells S-16 and S-17) in 1997. The Sector 4 wells were discontinued in September
1998 (Figure C-2). Sector 3 extraction wells were discontinued in 1999.
Groundwater extraction continues for hydraulic containment in the portion of the Site enclosed by the Sector 1
slurry wall and for isolated areas directly west of the slurry wall bordering Sector 2. Treated water is discharged
under permit number 4111-03 to the King County publicly-owned treatment works (POTW). Off gas from the air
5 Additional remedial background information can be found in Appendix H.
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stripper was carbon-treated prior to atmospheric release under a Puget Sound Air Pollution Control Agency
permit (Notice of Construction 6840; Registration 12738). On June 26, 2018 the Puget Sound Clean Air Agency
concluded that this project no longer requires a Notice of Construction permit because it has a de minimis impact
on air quality and does not pose a threat to human health or the environment.
Slurry Wall
Remedial workers installed a 40-foot-deep, 4,400-foot-long slurry wall (Figure 2) in October 1988 around Sectors
1 and 4. It was a field modification that supplemented the remedial action described in the 1985 ROD and the
1986 RODA before issuance of the 1995 ESD. The slurry wall was included in the remedy to provide horizontal
flow control in the upper aquifer to improve the pumping and cleanup efficiency and to provide extra protection
for Mill Creek and the East Drain. According to the 2000 Cap operation and maintenance (O&M) plan, a shallow
breach in the slurry wall (250-foot section) west of Sector 4 was replaced with sand backfill to an elevation of
more than 7 feet. This segment is monitored for groundwater quality discharge to Mill Creek (see Figure 2).
The ESD maintained the slurry wall containment remedy and added the construction of a supplemental isolation
wall immediately south of the South 196th Street right-of-way that would separate Sector 1 and Sector 4 (Figure
3). The isolation wall was constructed using a soil-cement-bentonite backfill material, which varied from the
original slurry wall mix to ensure additional structural stability required to facilitate plans by the city of Kent to
construct an embankment across the Site at the South 196th Street corridor for a major east-west arterial. With the
isolation wall, the area north of South 196th Street, Sector 4, was segregated from the Sector 1 source area.
Surface Water
Implementation of the surface water monitoring program, including Mill Creek and the East Drain, began in
January 1988. In April 1990, the cleanup achieved interim goals for Mill Creek. EPA issued a Preliminary Close-
Out Report for the Site in December 1991.
Remediation of East Drain sediments took place in 1993; over 1,140 tons of sediment were disposed of off-site
and gravel borrow was used as backfill. An interceptor system between the Interurban Trail and the East Drain
was constructed; it included a well point extraction system installed in late 1993. The East Drain interceptor
system operated for two years and use was discontinued in December of 1996 as part of the containment
remediation strategy.
Trans Plume Area
In 1999, EPA approved the transition of the Trans Plume Area (Sector 3) to monitored natural attenuation
(MNA), see Former VOC Area, MNA Area in Figure 3. In April 2000, extraction wells (T2, T3 and T4) within
the Trans Plume Area were shut off because geochemical conditions in the soils support biological reductive
dechlorination of target VOCs. Monitoring of VOCs (TCE, cis-l,2-DCE and vinyl chloride) in the Trans Plume
Area continues.
Additional Soil Removal
The 1995 ESD required treatment of another 5,000 cubic yards of contaminated soil. After the boundaries of a
suspected hot spot were determined to include over 5,000 cubic yards of highly contaminated soil, the areas were
excavated and disposed of off-site.6 The excavation was backfilled with lifts of clean gravel and crushed rock.
Hot spot cleanup activities began in March 1997 and finished in October 1997.
The 2000 Long-Term Contingency Plan (updated in 2009) identifies procedures for evaluating containment and
actions to be taken if those procedures indicate a loss of containment (i.e., if CACs are exceeded). The Trust
currently maintains the Site.
6 Containing chlorinated VOCs higher than 10 milligrams per kilogram (mg/kg), aromatic VOCs higher than 20 mg/kg, total
petroleum hydrocarbons (TPHs) higher than 10,000 mg/kg, and/or metals higher than 25,000 mg/kg.
12
-------
Institutional Control. Summary
Institutional controls are included as part of the remedy for OU2 and required by (lie 1995 ESD (Table 2). The
I9S6 ROD A noted that institutional controls are required in the form of restrictive covenants or deed notices so
prohibit use or extraction of groundwater and to prohibit any land use thai would disturb the integrity of the final
cover or any other component of the containment or monitoring system.' They have been drafted i.n the form of a
1999 Institutional Control Work Plan, which has been implemented for groundwater {informational institutional
controls) but not for The capped area.
Surrounding property owners receive annual notifications listing restrictions to groundwater use and noting that
remedy components may be located on their property, such as monitoring wells, clean cover soil, or other
remediation measures. The letters state (hat any excavation, earthwork, or other property improvement work that
has she potential to disturb these features -.honkl be carefully planned and coordinated with the Trust and that
disturbance to these features mils! be promptly repaired f Appendix L). Additionally, existing local regulations
prohibit groundwater extraction or use of the water for potable purposes in the affected area if water is publicly
available. Existing regulations take the form of King County' Health Department regulations.5 Ecology water right
permits, zoning, and additional local environmental permitting, see Appendix M for additional details. The
existing and probable future zoning and land use near Western Processing consists of commercial and light
industrial operations. The site property is fenced and the Trust maintains an office at the Site for added security
and remedy maintenance purposes (Figure 1). Ownership issues liave been a barrier to implementing institutional
controls at the Site. See Table 2 for a summary of the institutional controls required and in place.
Tulilc 2: Mimnuin ni lM.iniud < uiurols {F( Vt
< iUHloh :iml Ati-:!*.
[ Inn Hit V'l
Ml 11!
Blivi.'ll (HI ( '!!!Tfill
( CMfHli'lMS
If*
Nudtd
ICs Called
I'll!' in (he
IH-iiiion
i ><¦«'!!]til-III*-
it't!
I'um-U
E(
i »¦
liili':!Sc ill!' Iil:lildifii>
Final capped area
(soil) and
momtonug system
Yes
Yes
0122049022b
Restrict any use that
would disturb the
integrity of the final
cover, or any other
component of any
containment system, or
the function of the
monitoring system
Not Implemented (1999
Institutional Control
'¦A orx. Flcin)
7 According to the 1986 RODA. the 1985 ROD foresaw the need for such restrictions and the Consent Decree required them.
8 Km 2 County legularions prohibit the installation of wells for the extraction and use of groundwater if there is a suitable
public warer supply within 1 mile of the property. Because the city of Kent operates a public water supply system within the
area, all nearby owners should use the Kent water system, per King Comity regulations..
13
-------
E .nuiiu-i'i'i'd
< tilfil 'ik :i!sn Siit
i I II'
linked ell < illTOili
( !iiisii(;n[ls
Ni'Ciicif
ICs Called
for in the
Di-eitin]]
ll¦
K
< >Si | i'f (SI 1 ¦
liili-dif iiiidtmiou:
hiipltnii^iiU".! inlet
jo) phmilt'J 1
Groundwater
Yes
Yes
3 829000015cg
3S29000010cf
3829000007"*
3829000030^
3829000025"
3829000040cf
3829000055cf
3829000065rf
3829000008cf
3829000009cf
3829000005c
3310600375°
3310600385C
0122049022c
01220490SSCS
0122049018cf
0122049089"
0122049053"
0122049010"
0122049107^
0122049034"
3310600425ef
331060032 5
3310600260"
3310600365"
3310600285"
3310600305"
3310600261"
6314400240'*
6315000124'f
6315000120'f
6315000102ef
6315000125ef
6315000140**
6315000020"
6315000040"
Prohibit extraction and
use of groundw ater
King Comity
regulations and annua!
property notifications as
stated in the 1999
Institutional Control
Work Pian:t
Notes:
a, httpr/Zaismaps kiiiscomitv-sov/parceiviewerZ.
b. Based on The maps of Area 1 as portrayed in the 1999 Institutional Control Work Plan.
e. Based on the Consent Decree references to "Area 1. Area V and Other Areas East ofMill Creek."
d. See Appendix M for additional details on existing regulations.
e. Based on property letter distribution list provided by Boeing on 5/30/2018.
£ Parcel receives Property Notification A. see Appendix L.
g. Parcel receives Properrv Notification B. see Appendix L.
14
-------
Figure 2: Institutional Control Map
250 500
1,000
I Feet
Sources: Rails-to-Trails
Conservancy, King County, 2016
Annual Report Figure 1-2, Esri,
DigitalGlobe, GeoEye, Earthstar
Geographies, CNES/Airbus DS,
USDA, USGS, AEX, Getmapping,
Aerogrid, IGN, IGP, swisstopo and
the GIS User Community.
Legend
Superfund Site Sector Boundaries r/yn Land Use and Groundwater
Hi Property Parcel Boundaries ^ Restrictions Required
— Slurry wall
— ¦¦¦ East Drain
ik | Impacted by Cleanup, Groundwater
I ' ' Restrictions Required
(Parcels Impacted by Former VOC
Area, MNA Trans Plume Area
- - Interurban Trail
Parcel Receives Annual Property Notification, see Table 2 and Appendix L.
^Skeo O
v ~ NORTH
Western Processing Co., Inc. Superfund Site
City of Kent, King County, Washington
Disclaimer This map and any boundary lines within the map are approximate and subject to change. The map is not a survey. The map is for informational
purposes only regarding EPA?s response actions at the Site.
15
-------
Systems Operations/Operation and Maintenance (O&M)
O&M activities required by the OU1 remedy were only necessary for the stormwater control portion of the
project. OU2 and OU3 O&M activities required to ensure effectiveness of the remedy generally include:
Operation of the groundwater extraction and treatment systems as long as necessary.
Maintenance of the RCRA cap, soil covers, slurry wall and the stormwater control system.
• Long-term monitoring of the groundwater and Mill Creek.
All O&M activities are the responsibility of the Trust. Boeing, as Corporate Trustee for the Trust, is currently
managing, operating, and maintaining site remedial components (including the Sector 1 cap, other soil covers,
slurry walls and stormwater management facilities) in accordance with the 2000 Site Cap Operation &
Maintenance Plan.
The treatment system has a programmable logic control (PLC) control which will either shut down the system or
send out alarms and continue with operation if operating parameters are outside the design limits. Landau
Associates has a Site O&M technician who is remotely connected to the system and able to respond (24 hours per
day, 7 days a week). In addition, the Site O&M technician conducts daily system checks, conducts equipment
inspections/troubleshooting/replacement/or repairs. System and monitoring program optimization are reviewed
annually and presented in the annual report.
The Trust meets with EPA and the state biannually to discuss remedy performance and opportunities for O&M
optimization such as discontinuing contaminant monitoring, decreasing or increasing monitoring frequency, and
evaluating contingency plans. Technical evaluations of new monitoring data are also conducted during the
biannual Governments' meeting to address any issues or adjust monitoring requirements as necessary, per the
Long-Term Contingency Plan.
III. PROGRESS SINCE THE PREVIOUS REVIEW
This section includes the protectiveness determination and statement from the 2015 FYR Addendum as well as
the recommendations from the 2013 FYR Report and 2015 FYR Addendum and the status of those
recommendations. The 2013 FYR Report deferred sitewide protectiveness until further information could be
obtained. A FYR Addendum was issued in 2015 to follow up on the relevant issues. Neither the 2013 FYR nor
2015 addendum made OU specific protectiveness determinations.
16
-------
Table 3: Protectiveness DetermiHattons/Statemeuts from the 2013 FYR and 2015 FYR Adrii-iuimn
'Mill] IV
Ol
1*1 »li-(-|i\ i'lll-s->
I'l uM'l fh i'lli'i\ M:t(eSItf')IS.
2013 FYR
Sitewide
Deferred
Based oil this Technical Assessment. a protectiveness
determination, related to the remedy for the Western Processing
Site caimot be made at this time. Additional data needs to be
collected for the sediment portions of the remedy i East Dram and
Mill Creek) to ensure they remain protectn e With the exception
of these sediment areas, the remedy cimentiy protects human
health and the environment in the short term because the
contaminated groundwater and soil 111 the source area are
contained within the slimy wall, the RCRA cap and the
containment pumping and treatment system. The groundwater
concentrations off the W estem Processing property have decreased
to below detection levels There are no current exposures to site
contaminants related to these portions of the remedy. However, for
the remedy to be protective m the long term, institutional controls
that will run with the land need to be placed on the properties
located within the area bounded bv the shurv wall
2015 Addendum
Sitewide
Protective in the Short
Term
The remedy at the Western Processing Site currently protects
human health and the environment because the contaminated
groundwater and soil in the source area are contained within the
slimy wall, the RCRA cap and the containment pumping and
treatment system. The groundwater concentrations off the Western
Processing property have decreased to below detection levels
There are no current exposures to site contaminants related to
these portions of the remedy. How evei. for the remedy to be
protective in ihe long term, institutional controls that will run with
the land need to be placed on the properties located within the area
bounded bv the slurrv wall.
17
-------
Table 4; Status of Recommendations from the 2IU3 I \ R and 2015 FIT?. Vdihudum
oi
!•« liir
Issue
Villi IT-
< HfTflll
si;ii lis
t UlTi'HI *s S ji i 1] s
IWripiio.-i
< ulllltlrlimi
¦ j 1'
2
Concentrations of
PAHs ill the East Drain
are elevated
considerably above the
State of Washington's
Freshwater Sediment
Standards, calling into
question the
protectiveness of the
sediment portion of the
remedy.
2013 FYR
Evaluate PAH
concentrations in
Mill Creek and
East Drain and
determine whether
contamination
found is related to
the site. Determine
whether the
sediment remedy is
protective.
Eva In a ted
and found to
be protective
As part of the FYR Addendum.
EFA determined that the East Drain
is not capable of supporting a viable
bentluc community due to its
ephemeral nature. Therefore, the
application of standards to protect
that community is not appropriate.
Additionally. EPA dismissed
concerns for bentliic communities in
Mill Creek sediment because
concentrations were not found to
exceed 1993 cleanup goals or the
2013 state Freshwater Sediment
Standards.
9/28/2015
2
Permanent institutional
controls that ran with
the land for those
parcels which
constitute Sector 1
Vwithin the boundaries
of the slurry wail 5 need
to be developed and
implemented.
2013 FYR
and
2015 FYR
Addendum
Develop and
implement
institutional
controls.
Ongoing
Institutional controls have not been
implemented, (1999 Institutional
Control Work Plan)
Ongoing
IV, FIVE-YEAR REVIEW PROCESS
Community Notification. Community Involvement and Site Interviews
A public notice was made available by newspaper posting in The Sarnie Times and the Kent Reporter ou 1 5<'2018
(Appendix D), The notices stated that the FYR was underway and invited the public to submit any comments to
the EPA. The results of the review and the report will be made available at the Site's information repository. Kent
Regional Library, located at 212 2nd Avenue North in Kent. Washington.
During the FYR process, interviews were conducted to document any perceived problems or successes with the
remedy that has been implemented to date. The interviews are summarized below, and the interview forms are
included in Appendix E
Ching-Pi Wang with Ecology, Lindsey Mahrt with Boeing, and Christine Kimmel with Landau Associates were
interviewed by email as part of the FYR process.
Clung-Pi Wang, with Ecology, stated that he thought the Site was mature and well managed, and that site
procedures are well-known and effective. Mr. Wang noted that cleanup levels might have changed since the
effective date of the Consent Decree and that lie was comfortable with the status of the institutional controls at the
Site.
Lindsey Malm with Boeing, representing the Trust, believes anient remedial activities are effective and
achieving goals of containment through the slurry wall, site cap and groundwater extraction treatment system. She
does no! think that the Site currently effects surroundins communitv. Additionally. Ms. Mahrt states that the Trust
j C> J J
lias been working with the city of Kent public works department to extend a public roadway over a portion of the
Site. She believes the anient remedy is effective ill maintaining containment.
18
-------
Christine Kimmel with Landau Associates, contractor for the Trust, stated that groundwater performance data
supported the cessation of pumping from Sectors 3 and 4 and that the treatment system operates 24 hours a day, 7
days a week to maintain hydraulic containment goals in Sector 1. She notes that the extraction system achieves
hydraulic containment goals, no evidence of cap erosion or damage has been observed, samples indicate
compounds of interest are below the reporting limit in the downgradient MNA area, and no recent adverse
impacts related to the Western Processing site have been observed in Mill Creek or East Drain. Elevated zinc
concentrations were determined to be a local and limited source, as elevated zinc concentrations in Mill Creek
(directly downgradient of Sector 4) were not reported. Zinc concentrations in Sector 4 continue to decrease.
Data Review
Data have been collected to assess the effectiveness of the containment remedy since the previous FYR, as
reported in the Site's annual monitoring reports, prepared by Landau Associates for the Trust. The sections below
describe the groundwater monitoring activities and analytical results for each containment area. Maps are
provided in Appendix C to show the locations of monitoring wells and the extraction well system.
The 1999 Long-Term Contingency Plan establishes that containment occurs when the further spread of remaining
site-related contamination is prevented. This occurs quantitatively in terms of three monitoring parameters:
• The difference in hydraulic heads measured at designated adjacent well or piezometer pairs.
• Groundwater quality measured at designated monitoring wells.
• Surface water quality measured at surface water monitoring stations.
For each of these parameters, contingent action criteria have been developed. These criteria represent the
benchmarks against which site data are compared to demonstrate containment.
Monitoring Hydraulic Gradient for Containment
The containment remedy requires that shallow groundwater (Zone A) maintain an inward gradient within the
slurry wall. PRPs collect groundwater elevation data from Zone A and Zone B monitoring well/piezometer pairs
within the slurry wall on a quarterly basis and use these data to determine groundwater flow gradients.
From 2012 through 2017, all piezometer (P) and well pairs except for two pairs indicated a continuous
inward/upward gradient. P26 (Zone B) had a slightly lower piezometric head (less than 1 foot) than RP28 (Zone
A) in September 2016, October 2017 and November 2017, which indicates a downward gradient at this location.
The nearest well pair in Sector 2, beyond the slurry wall, only showed contamination above CACs in Zone A
(5M4A) over the last five years, not in Zone B (5M4B), which has not shown elevated cis-l,2-DCE, TCE or vinyl
chloride concentrations since 2001. This suggests that despite an observed downgradient gradient in this area,
contamination has not breached the slurry wall in the deeper Zone B. 1M33B (Zone B) had a slightly lower
piezometric head (less than 1 foot) than P50 (Zone A) in March 2017 and in November 2017. There are no
monitoring wells downgradient of that pair before Mill Creek. Both pairs showed positive piezometric head in
readings in December 2017 and did not indicate a significant trend reversal in hydraulic gradient. The five-year
averages per well/piezometer pair (Zone A and B) indicate that Zone B is maintained with a higher piezometric
head than its Zone A counterpart, indicating an inward gradient is being maintained. Table 1-1 in Appendix I
provides the Sector 1 elevations. Additionally, during each sampling period, the average of the Zone B elevations
within Sector 1 were higher than the Zone A elevations (Figure 1-1, Appendix I).
Groundwater Quality
Groundwater monitoring takes place across the Site, in all four sectors. Figure C-l shows monitoring locations.
Sector 1 Wells (inside slurry wall and capped area)
Monitoring wells within the Sector 1 slurry wall and screened within Zone A (shallow) continue to be
contaminated due to the residual contamination on site. This groundwater is captured by the containment
extraction system.
19
-------
Four Zone B (deeper) wells (NIB, N3B, N4B, and N7B) are monitored on an annual basis. Two of those wells
(N3B and N4B), had contaminant concentrations above the CACs during this. N4B had an isolated set of detected
cis-l,2-DCE (8.3 (ig/L, CAC 5 (ig/L) and toluene (6.6 (ig/L, CAC 5 j^ig/L) in 2017 (Table 5). Cis-1,2-DCE has not
been detected in this well since 1988 and this was the first detection of toluene. N4B detections appear to be
isolated events and monitoring will continue.
N3B had consistently high levels of zinc over the last five years, see Figure 1-7 and Table 5, and had consistently
lower levels prior to 2010. Zinc levels ranged from below the CAC of 45 (ig/L to 2,680 (ig/L. In addition, HPMO
and OPMO (both oxazolidinones) were detected above CACs in 2016 and 2017 in N3B. The remaining two Zone
B wells (NIB and N7B), have no detections above the respective CACs. Based on discussions during semiannual
meetings, evaluation of the data indicates that monitoring at the Zone B wells in Sector 1 will continue.
Groundwater MNA Trans Plume2
Compliance with the 1,2-DCE performance standard is the CAC, which is when the total 1,2-DCE (cis- plus
trans-) concentrations are at or below 70 (ig/L. The historic plume area is monitored for TCE, cis-l,2-DCE and
vinyl chloride to approximately 50 feet bgs.
Wells immediately downgradient of Sector 1, M4B, 7M26B, 15M38B, 15M40B and T2 (Figure C-l) are sampled
annually. Wells further downgradient of Sector 1, 15M15B, 15M16B, 15M17B, 15M32B, 15M39B, 15M45B, T3
and T4, are sampled every five years. All MNA wells were sampled in 2017 to support the current FYR. The
next sampling event for the further downgradient wells will be in 2022
Well 6M6B was decommissioned in October 2012 to facilitate the planned 72nd Avenue South roadway
expansion. Well 15M42B is located between two traffic lanes of South 196th Street. For safety reasons, it is only
sampled if VOCs are reported at the nearest upgradient well (15M45B). No VOCs were reported in well
15M45B; therefore, no sample was collected from 15M42B.
VOCs were not detected above CACs, nor above laboratory reporting limits, in any of these wells in the last five
years. Cis-1,2-DCE was last detected above a CAC in December 2002 in 6M6B. The last time TCE was detected
above a CAC was in November 1992 in 15M15B. The last time vinyl chloride was detected above a CAC was in
December 2002 in 6M6B. These data continue to support the conclusion that breakdown of contaminants is
occurring, and attenuation is happening, as expected.
Sector 2 Wells
5M4A monitors Zone A and 5M4B monitors Zone B and are downgradient from the Sector 1 slurry wall. 5M4A
had levels of chlorobenzene that consistently exceeded the well's CAC of 5 (ig/L in each of the last five years
(ranging from 8.6 (ig/L in 2013 to a high of 15 (ig/L in 2015; see Table 5). In 2013, 2014 and 2017, the well
exceeded the CAC for HPMO (2,010 (ig/L, 1,060 (ig/L and 1,360 j^ig/L: CAC 870 (ig/L). It exceeded the CAC for
OPMO (2,180 (ig/L; CAC 1,600 (ig/L) in 2013 only (see Figure 1-3 and Table 5). Historically, shallow
groundwater at well 5M4A was contaminated with chlorinated VOCs and zinc but generally, levels had decreased
over time. Figure 1-4 shows that vinyl chloride may have fluctuated and not noticeably decreased in the last
decade. Vinyl chloride was not detected in 5M4A in 2017, 2016 or 2015.
5M4B has not shown elevated concentrations of cis-l,2-DCE, TCE or vinyl chloride since 2001. 5M4C was
decommissioned in 2012. The nearest wells beyond the slurry wall, extraction wells U1 and U2, were not sampled
for chlorobenzene but according to the annual reports, U1 has not shown elevated levels of vinyl chloride since
2008.
Sector 4 Wells
Over the last five years, only a few monitoring wells had groundwater exceedences of CACs (Table 5).
9 The Consent Decree refers to an off-site plume of trans-l,2-DCE located west of the Site. Investigations since then have
identified the 1,2-DCE present as primarily the cis isomer.
20
-------
9M9B is the only Sector 4 monitoring well within the slurry wall that has contaminants above CACs. See Table 5.
Cis-1,2-DCE was above the CAC in 2014 and 2017 (7.3 (ig/L, 6.5 j^ig/L: CAC 5 j^ig/L): vinyl chloride has been
above the CAC of 2 (ig/L, fluctuating from under the reporting limit to a high of 6.8 (ig/L in 2015 and most
recently 4.1 (ig/L in March 2018. Historical concentrations are charted in Figure 1-6.
9M44A is located next to and downgradient of the Sector 4 slurry wall, between the slurry wall and Mill Creek.
The well is positioned to monitor shallow groundwater exiting Sector 4 by the repaired slurry wall breach. This
well has reported levels of vinyl chloride above the CAC annually since 2014, but previously had not exceeded
these concentrations since 1999. There are no downgradient Zone A wells beyond 9M44A (see Figure C-l). It
should be noted that groundwater is no longer extracted from the Sector 4 extraction wells. Extraction wells S16
and S17 were last operated in 1988. Increases in vinyl chloride concentrations are likely due to breakdown of cis-
1,2-DCE in the area. These wells will continue to be monitored.
21
-------
Table 5: Monitoring Wells with CAC Exceedances, 2013 to March 2018
«-K
I ¦*-rtssniii.iii?
i
t ug, L/
3rd
Quarter
2013
(ugL)
J.i ."is!
V--I ;i-:
:i'l4 : U4
¦ ii-jli
i .i
'Jll.tl ll'I
2>'\*
• wj 1 :
.vi!
(,!¦¦ >; ii'i
In | f=
¦ ii «_¦ i !
i ¦.<
1,111.11 U-1
2''[i!
lll-J 1 i
3rd
1111 s
2016
«irj t i
^ 11 iriiMii-in
2016
(ug/I..)
1st
Quarter
2017
MIL' I 1
3rd
ill.:
2017
(Mg'U
1st
Quarter
2018
(iig/I.)
\,iii ¦¦¦
\ • .
HPMO
2 010 J
n r
\-T
1.360 J
llcXt (O aiullj1
wall,
downgixidient.
Zone A
OPMO
1,600
2,180 J
NT
1,3601
NT
162 J
NT
25 01
NT
NT
808 J
NT
Chlorobenzene
5
8.6
NT
11
NT
15
NT
15
NT
NT
12
NT
9M9B
cts-l,2~DCE
5
5 U
73
5U
5 U
5 U
5 U
5UJ
NT
6 5
5 U
5 U
Sector 4, within
slurry wall.
Zone B
Vinyl chloride
2
2U
5.5
3.1
6.8
2 U
4.7
211
NT
5.7
2 U
4.1
9M44A
Vinyl chloride
2
2tl
2 U
3.9
51'
4.4
2 U
23
NT
2 U
2.4
2 U
Right outside
Sector 4 sluny
wall,
downgradient.
Zone A
N3B
HPMO
25
25 U
NT
25 U
NT
25 U
NT
352 J
43 J
NT
377
NT
Sector 1, within
slurry wall.
Zone B
OPMO
25
25 U
\
25 U
NT
25 U
NT
24- J
25 U
NT
293
NT
Zinc (total)
45
85.2
53.6
714 J
309
287
294
2,3M
283
34.7
2.680
155
N3A1*
Zinc (total)
No CAC
84.100
NT
30,6001
NT
13.800
NT
14.000
NT
NT
9.950
NT
N4B**
cis-l,2-DCE
5
50
5 U
5 U
NT
5 U
NT
5 U
NT
NT
8.3
NT
Sector 1, within
slurry wail.
ZoneB
Toluene
.5
5 U
5 U
5 U
NT
5 U
NT
511
NT
NT
6.6
NT
Notes
J = Data validation flag indicating the analyte was positively identified; the associated numerical value is the approximate concentration of the analyte in the sample.
U = Indicates compound was analyzed for but was not detected at the reported sample detection limit.
UJ= The compound was analyzed for but was not detected. The reported quantitation limit is approximate and may be inaccurate.
NT = Well was not sampled for this analyte.
* = Included for comparison with N3B because of proximity.
** = Specific data was not included in the 2016 annual report but report text stated that the 2016 analytical results were all below the respective laboratory reporting limits.
Bold indicates the value exceeds the CAC
22
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Mill Creek and East Drain (Surface Water Quality)
Performance standards for Mill Creek surface water require that the concentrations of indicator chemicals
(identified in the 1986 Consent Decree) and other priority pollutants at a designated downstream compliance point
in Mill Creek meet federal AWQC for aquatic organisms. When the concentrations at the "background" upstream
monitoring station approach or exceed an AWQC, the compliance level for site concentrations is adjusted based
on a formula in the Consent Decree. Contaminants of interest in Mill Creek and the East Drain are zinc,
chromium (total), cadmium, copper, nickel and lead.
EPA did not specify performance standards for water quality in the East Drain because the area is not capable of
supporting a viable benthic community due to its ephemeral nature; application of standards to protect that
community is not appropriate. However, as available, the area is sampled for cadmium and zinc.
Surface water monitoring takes place at three stations in Mill Creek (Stations upstream CI, downstream C3 and
downstream C4) and at two stations in the East Drain (Stations D1 and D2), as shown on Figure 3. The Mill
Creek stations are sampled semi-annually. The East Drain stations are sampled annually.
Concentrations of all metals analyzed at Stations CI, C3, and C4 in 2013, 2014, 2015, 2016 and 2017 were below
their respective AWQC or performance standards, except for lead in 2014. Lead concentrations above the
previously designated performance standard of 0.66 j^ig/L were reported during March 2014 at CI (1.28 (ig/L). C3
(1.27 (ig/L) and C4 (1.32 j^ig/L). Since elevated lead concentrations were detected at upstream/background
location CI, the performance standard was adjusted at C3 from 0.66 (ig/L to 1.86 (ig/L. The reported
concentration at C3 is below the adjusted performance standard. Lead concentrations during September 2014
were all below the initial or adjusted performance standards.
Groundwater Extraction, Treatment and Discharge
Discharge Permit Compliance
As part of the Site's remedy, all air emissions were to comply with a discharge permit issued from the Puget
Sound Air Pollution Control Agency. Additionally, the collected treated wastewater effluent from the treatment
systems must meet discharge criteria specified in the POTW discharge permit.
Over the last five years, the treatment plant has operated continuously in compliance with the King County
Industrial Waste Division (KCIWD) water discharge permit and a Puget Sound Air Pollution Control Agency
permit, with brief shutdowns for routine maintenance. Under the Puget Sound Air Pollution Control Agency
permit, the contractors must limit air emissions of vinyl chloride to less than 140 pounds during any 12-month
period. Over the last five years, annual emissions have been well below the 140-pound limit, between 4 pounds
and 6 pounds total (Table 1-2). On June 26, 2018 the Puget Sound Clean Air Agency concluded that this project
no longer requires a Notice of Construction permit because it has a de minimis impact on air quality and does not
pose a threat to human health or the environment.
Groundwater Extraction System Performance
The groundwater extraction system at the Site operates to provide hydraulic containment of contaminated
groundwater. Extracted groundwater is treated before discharge and meets KCIWD discharge permit standards.
Between 2013 and 2017 the volume of groundwater extracted and then treated for Sector 1 and Sector 2 wells
increased from 2,069,212 gallons annually to 3,728,813 gallons annually in 2017. This was mostly due to an
increase in gallons extracted in Sector 1 (Figure 1-2, Appendix I). In 2014, Sector 1 extraction wells were
refurbished using acid cleaning methods to improve the performance of the extraction system; the average
monthly extraction rates doubled (from 2.9 to 5.8 gallons per minute).
The mass removals for selected inorganic and organic contaminants in extracted groundwater were calculated for
the entire system using contaminant concentrations in the treatment facility influent and the influent flow volumes
from site annual reports. Table 6 provides additional information.
23
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Table 6; Estimated Contaminant Mass Remm id by Groundwater I.\( rai-iion. 2013 to 2017*
Yi-;tr
/iim
< K IK T
(piHnuM
TC'E
Vin> 1
< iiluiiilt-
11 > i > u 11 ¦ K ¦
Ml'MO
i fMSUIllKl
OI'MO
1 i
2013
3.2
17.3
3.9
4.4
12.8
45.7
2014
5.3
18.9
4.7
5.0
17.5
67,2
2015
3.S
22.0
4.5
5.3
20,8
76,2
2016
3.6
20.0
4.2
4.8
23.7
90.6
2017
4.5
27.3
4.7
6.4
27.5
118.0
Notes:
* Table includes contaminant extractions of significant mass for contaminants of interest.
Extraction mass for contaminants of interest were similar across the last few years: masses generally increases
with higher groundwater extraction rates. There are no targets for mass removal and gallons treated: this is a
continuous containment effort.
24
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Figure 3: Detailed Site Map
| Slurry
< BJvaiir
~o in
c Breach
^ 1
/ Sector 4 i
South 196th Street
Isolation
Wall
-Treatment Plant
r (J Pi | BU ¦
-Western Processing Office
3
Sector 2
RCRA
250
500
1,000
Feet
Legend
Sources: Rails-to-Trails Conservancy, 2016
Annual Report Figure 1-2, Esri, DigitalGlobe,
GeoEye, Earthstar Geographies,
CNES/Airbus DS, USDA, USGS, AEX,
Getmapping, Aerogrid, IGN, IGP, swisstopo
and the GIS User Community.
Superfund Site
Sector Boundaries
Slurry Wall
Surface Water
Sampling Point
East Drain
i - -
Former VOC Area,
MNATrans Plume
Area
--- Interurban Trail
^ Skeo
Western Processing Co., Inc. Superfund Site
City of Kent, King County, Washington
Disclaimer This map and any boundary lines within the map are approximate and subject to change. The map is not a survey. The map is for informational
purposes only regarding EPA's response actions atthe Site.
25
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Site Inspection
The site inspection took place on 1/9/2018. Participants included EPA RPM Piper Peterson and EPA hydrologist
Bernie Zavala, Ching-Pi Wang with Ecology, Lindsey Mahrt with Boeing, Christine Kimmel with Landau
Associates (PRP contractor support), and Treat Suomi and Sarah Alfano with Skeo (EPA FYR support
contractor). The purpose of the inspection was to assess the protectiveness of the remedy. The site inspection
checklist is provided in Appendix F. Site inspection photos are provided in Appendix G.
Site participants met in the Western Processing Trust building on site and discussed site conditions, recent
sampling and procedures before beginning the outdoor site tour, which included components of all four sectors.
Participants toured the treatment building, identifying the monitoring system and power failure backup system as
well as file storage. Treatment components for the air stripping system appeared to be in good condition.
Participants also walked around the Site's capped area, noting that the area was secured and well-vegetated. Wells
were easily identifiable. The tour continued outside the capped area where the East Drain was viewed. Remedial
components in the area were secure, though one piezometer along the East Drain appeared to have exterior
damage from lawncare services that were not part of site O&M activities. O&M contractor support made a note to
contact the lawncare personnel and repair the cover. Participants walked through and around Sector 4, noting the
location of the isolation wall. Participants also viewed wells in the commercial area where MNA took place and
walked along the new on-site road before viewing the corresponding feeder vault for the in-road well. Participants
noted various locations along Mill Creek, including surface sampling locations.
Afterwards, Skeo visited the Site's information repository, Kent Regional Library, located at 212 2nd Avenue
North in Kent, Washington. Site records available included the 1994 Administrative Record and the 2013 FYR
Report. Contact information was obtained for the government documents librarian. EPA will follow up to include
the FYR.
V. TECHNICAL ASSESSMENT
QUESTION A: Is the remedy functioning as intended by the decision documents?
Question A Summary:
Yes, the remedies for OU1, OU2 and OU3 are functioning as intended by the decision documents.
The PRPs removed surficial hazardous waste and cleared surface structures before grading and other stormwater
control measures were implemented. The remedies are currently maintained through a cap and a system of
hydraulic containment of groundwater that includes a slurry wall, extraction and treatment of groundwater, and
the assessment of groundwater quality within the MNA Trans Plume Area, the slurry wall and surface water.
O&M activities are ongoing, in keeping with the Site Cap O&M Plan.
Monitoring wells within the Sector 1 slurry wall and screened within Zone A continue to indicate contamination
above the reporting limits. These locations are representative of residual contamination on site and are in the area
contained by the slurry wall and captured by the containment extraction system. N3B located in Sector 1, inside
the slurry wall and within the capped area, continued to report concentrations of contaminants above the CACs
during this FYR period. N3B had consistently high levels of zinc over the last five years and had consistently
lower levels prior to 2010. Zinc levels ranged from below the CAC of 45 (ig/L to 2,680 (ig/L. In addition, N3B
began to show levels of HPMO and OPMO above CACs in 2016. Elevated contaminants at N3B appear to be
isolated as downgradient Zone B wells continue to report concentrations below the reporting limits.
5M4A, which monitors Zone A and is in Sector 2, has repeated exceedances for several contaminants.
26
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Evaluation of wells occurs during biannual Governments' meetings with concurrence on any additional
evaluations needed under the 1999 Long-Term Contingency Plan to determine any potential loss in containment.10
Based on discussions during semiannual meetings, evaluation of the data indicates that monitoring of the wells
with exceedances will continue.
Within the MNA Trans Plume Area wells, VOCs were not detected above laboratory reporting limits or CACs in
the last five years. Results indicate that complete reductive dechlorination of TCE and breakdown products
through to non-toxic products continues to occur.
Though the OU2 remedy requires institutional controls to protect the cap and slurry wall, and to limit
groundwater usage on site and in the immediate area, institutional controls have only been implemented for
groundwater and not for the capped area. There is no immediate risk of exposure due to the lack of on-site land
use institutional controls. Groundwater and the capped area are managed appropriately on site and access is
limited by a fence and a gate. Surrounding property owners receive annual notifications for relevant remedy
component locations and groundwater areas (Appendix L) and existing local regulations restrict groundwater
extraction and use. To ensure that there are no exposures in the future, institutional controls should be
implemented for the capped area.
QUESTION B: Are the exposure assumptions, toxicity data, cleanup levels and RAOs used at the time of the
remedy selection still valid?
Question B Summary:
Yes, the exposure assumptions, toxicity data, cleanup levels and RAOs used at the time of the remedy selection
are still valid.
A review of ARARs (Appendix J) and screening level risk review (Appendix K) indicates the remedy remains
protective. There were no site-wide cleanup standards established for groundwater contaminants. The CACs are
not based on MCLs or health-based concentrations, A screening-level health evaluation of the CACs (Appendix
K) shows that most of the CACs fall within or are below EPA's risk management range of 1 x 10"6 to 1 x 10"4
except for vinyl chloride and chromium. The CAC for vinyl chloride is a statistically-based value which exceeds
the upperbound of EPA's cancer risk range and the federal MCL. The CAC for lead exceeds the noncancer hazard
quotient (HQ) of 1 however the concentration is equivalent to the background concentration and Superfund
remediations cannot remediate to concentrations below background. Based on the screening-level risk evaluation,
only the CAC for vinyl chloride exceeds the MCL and EPA risk range. The CAC remains valid because there are
no current completed exposure pathways.
The only contaminant cleanup standard established at the time of remedy selection was for the cis-l,2-DCE off-
site plume. A review of current federal groundwater MCLs indicates this remedial goal remains protective.
Concentrations of chlorobenzene outside the slurry wall are below the current MCL but above the MCL for vinyl
chloride.
The soil remedy included the excavation or covering and capping of all remaining contaminated soils outside the
Western Processing Company property that are above background (i.e., the 1 x 10"5 excess cancer risk level), with
bench-scale tests of soil solidification techniques. Off-site soils that exceeded the acceptable daily intake or cancer
risk level of 1 x 10-5 were excavated. To determine if soil excavation levels remain protective, this FYR compared
the excavation levels to EPA's current composite worker regional screening levels (RSLs) (Appendix K, Table K-
1). Composite worker RSLs are used because the anticipated future use of the Site is industrial/commercial. The
evaluation shows that the excavation levels for off-site and on-site PCBs remains protective because it falls within
10 According to the 1999 Long-Term Contingency Plan, an indication of an exceedance will trigger a technical evaluation of
the probable causes followed by notification and, if necessary, a remedial response recommendation to the governments for
approval. The recommendation may consist of implementing predetermined contingent actions.
27
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EPA's acceptable risk management range of 1 x 10 6 to 1 x 10 4 and is below the target risk level selected in the
ROD of 1 x J 0" '. The lead cleanup goal of 1.000 mg. kg is based on outdated guidance. EPA OLEM Directive
9285.6-56 (May 17. 201") recommends using the Adult Lead Methodology to assess lead risks from soil for the
non-residential Superfund site scenarios. The recommended soil Preliminary Remediation Goal is 1.050 mg kg
which corresponds fo a target blood lead concentration of 5 tig/deciliter. This updated goal is less stringent than
the original cleanup goal, therefore the soil cleanup goal is still protective (Appendix K. Table K-2),
The 1985 FS identified l.i.l-TCA as a frequently detected contaminant for both soil and groundwater inside
Sector 1. Since the 1985 FS. a slurry wall and RCRA cap have been installed for Sector I. Current groundwater
results indicate l.i.l-TCA is not present at concentration above the reporting limit in Zone A wells located
outside Sector 1 and all Zone B wells (all Sectors). Ll.l-TCA has been detected in limited groundwater samples
outside of Sector 1 at wells 5M4A and 13M30A. Well 13M30A had nvo detections in 1994 and 2000 at
concentrations slightly exceeding the reporting limit and at concentrations within the margin of error. Weil 5M1A
had six detections ranging from 6 to 156 ug/L with the last detection in 1991. Historically. 1.4-dioxane was used
as a stabilizer foi Ll.l-TCA. Because early site investigations did not sample for 1.4-dioxane. PRPs should
evaluate an appropriate plan to sample for 1.4-dioxane and take additional action if necessary.
QUESTION' C: Has any other information come to light that could call into question the protectiveness of the
remedy1
Question € Summary:
No other information has come to light that could call into question the protectiveness of the remedy.
VI. IS SUE S/RE C L\ IEND AT IONS
(M iVnviliKiiti Isiiu'v Recommendations IiU-ntiTird in the I YR:
OU1
hstft's ami lvi'< !>ir!mi'!s
-------
OU(s): 2 and 3
Issue Category: Remedy Performance
Issue: l.l.l-TCA was identified as a frequently detected contaminant for soil and
groundwater. Historically. 1.4-dioxane was used as a stabilizer for l.l.l-TCA. however
sampling for 1.4-dioxane has not occuned.
Recommendation: Ei aluate an appropilate plan to sample for 1,4-dioxane and take
additional action if necessary.
Affect Current
Proiectiveness
Affect Future
Protectiveness
Party Responsible
Oversight
Party. Support
Agency
Milestone Date
No
Yes
PRP
EPA
9/1/2019
VII. PROTECTTVENESS STATEMENT
Operable Unit: Protectiveness Determination:
OU1 Protective
Protectiveness Statement:
The remedy at OU1 is protective of human health and the environment. Surficial hazardous wastes were removed
and surface structures were cleared so that no completed exposure pathways exist.
Operable Unit:
OU2
Protectiveness Determination:
Short-temi Protective
Protectiveness Statement:
The remedy at OU2 currently protects human health and the environment because there are no current completed
exposure pathways. The containment area is surrounded with a slurry wall to prevent migration of groundwater
contamination. Groundwater and surface water monitoring do not indicate that contaminant concentrations have
increased. However, for the remedy to be protective in the long-term, the following actions need to be taken to
ensure protectiveness: implement appropriate institutional controls at the Site and evaluate appropriate sampling
for 1.4-dioxane to determine if it is present in site media and take additional action if necessary.
Operable Unit: Protectiveness Detennmation:
OU3 Short-term Protective
Pj otecriveness Statement:
The remedy at OU3 currently protects human health and the environment because there are no current completed
exposure pathways. Contaminated sediment from the East Drain and Mill Creek lias been removed and surface
wafer monitoring continues. However, for the remedy to be protective in the long-term, the following action needs
to be taken to ensure protectiveness; evaluate appropriate sampling for 1,4-dioxane to determine if it is present in
site media and take additional action if necessary.
29
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Protectiveness Defemnnation;
Short-term Protective
Protectiveness Statement:
The remedy currently protects human health and the environment because the remedy at OU1 is protective, and
there are no current completed exposure pathways at OU2 and OU3. However, for the remedy to remain protective
in the long-term, the following actions need to be taken to ensure protectiveness: implement appropriate
institutional controls at the Site and evaluate appropriate sampling for 1.4-dioxaiie to determine if it is present in
site media and take additional action if necessary.
VIII. NEXT REVIEW
The next FYR Report for the Western Processing Co., Inc. Superfimd site is required five years from the
completion date of this review.
30
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APPENDIX A - REFERENCE LIST
Record of Decision, Western Processing Superfund Site, U.S. EPA, August 1984.
Record of Decision, Western Processing Superfund Site, U.S. EPA, September 1985.
Amended Record of Decision, Western Processing Superfund Site, U.S. EPA, September 1986.
Copy of Western Processing Consent Decree, filed October 16, 1986.
Explanation of Significant Differences, Western Processing Superfund Site, U.S. EPA, December 11, 1995.
2013 Annual Evaluation Western Processing, Landau Associates, June 16, 2014.
2014 Annual Evaluation Western Processing, Landau Associates, June 3, 2015.
2015 Annual Evaluation Western Processing, Landau Associates, June 13, 2016.
2016 Annual Evaluation Western Processing, Landau Associates, June 12, 2017.
Second Five-Year Review, Western Processing Superfund Site, U.S. EPA, September 1998.
Third Five-Year Review Report, Western Processing Superfund Site, U.S. EPA, September 2003.
Fourth Five-Year Review Report, Western Processing Superfund Site, U.S. EPA, July 2008.
Fifth Five-Year Review Report, Western Processing Superfund Site, U.S. EPA, September 2013.
Addendum to Fifth Five-Year Review Report, Western Processing Superfund Site, U.S. EPA, September 2015.
Site Cap Operation & Maintenance Plan Western Processing, Western Processing Trust Fund, May 30, 2000.
Institutional Controls Work Plan, Western Processing, Western Processing Trust Fund, November 16, 1999.
Long-Term Contingency Plan Addendum, Western Processing, Landau Associates, January 7, 2009
A-l
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APPENDIX B - SITE CHRONOLOGY
Table B-l: Site Chronology
i.M'Stl {>;!!(¦
V. -stern Processing began operation* on site
1961
EPA completed preliminary assessmentsite investigation
December 1. 1982
EPA proposed the Site for listing on the NPL
December 30. 1982
Court order closed site operations
July 1983
EPA performed emergency removal of site wastes.
July 1983
EPA placed the Site on the NPL
September S. 1 983
EPA beaan combined RTFS for OU2
September 23. 1983
EPA be aan OIJI FS
June 13.1984
Site stakeholders began OU1 cleanup
July 21. 1984
Court and site stakeholders entered into Site's first Consent Decree
Aueust 19S4
EPA completed OU.1 FS
EPA issued OUi ROD
August 5, 1984
Site stakeholders completed OUI cleanup
September 30. 1984
EPA issued ROD for OUI
EPA completed combined RI/'FS for OU2
September 25, 1985
EPA issued RODA
September 4. 1986
Court and site stakeholders entered into Site's second Consent Decree
October 16. 1986
Site stakeholders began OU2 remediation efforts
July?. 1987
Remedial contractors began operations at groundwater treatment system
October 1.988
Remedial contactors constructed the sluny wall
October 1988
EPA issued Sue's Preliminary Close-Out Report
December 1991
EPA completed Site's first FYR Report
January 4. i S'93
Remedial contractors began Mill Creek restoration (OU3)
Julv 1. I°f93
Site remedial efforts achieved three-year performance standards for Mil Creek
August 1093
Site stakeholders began OU2 remediation
December 22. 1993
Remedial contractors installed East Drain extraction system
November 1994
Remedial contractors completed Mill Creek restoration (OU3)
March?, 1995
EPA issued ESD for OU2
December 1995
Remedial contractors installed containment wells
June 1996
Remedial contractors started operating the new groundwater treatment system
July 1997
EPA completed Site's second FYR Report
September 1998
Remedial contractors completed construction of RCRA cap
October 1999
Remedial contractors started MNA for Trans Plume Area
April 2000
EPA issued Site's third FYR Report
September 30. 2003
EPA issued Site's fourth FYR Report
July 24. 2008
The City built the 72nd Avenue Extension
December 2012
EPA issued Site's tilth FYR Report
September 27, 2013
EPA issued Addendum to Site's fifth FYR Report
September 28, 2015
B-l
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RP18I
9M43A
8M8B
BB68
9M9B
.RP44.
Lidco Site
^15M16B
7M26B
r1 M33B N7B
Treatment Plant-
15M38B
¦I5M15B
'N5A2
ij\ I RP28
liter 2®™
^-5M4A
i I5V4CB
n-ia-k Sector
H1A2#
N1B'
11NH
APPENDIX C - SITE MAPS
Figure C-l: Well and Piezometer Locations (Landau Associates, 2016 Annual Report)
&BMt£E3£L_ s i36th st
^15Md2B 15M32ET#- -
• !SMi5B
Trans Plume Area
0J15W39B
'3M30A
15M17C a'i 5M17B
Legend
0 Monirtonng Well [ J ^afcefe
C) Piezometer Slurry Wall
O Surface Water Sample Mill Creek
Natural Attenuation Area East Drain
~1 Sector
Note
1. Black and white reproduction of ttiis color
original may reduce its effectiveness and
ead to incorrect interpretation.
bca e in eet
Data Source: Esri World tmagery.
Figure
Site Features and
Monitoring Locations
western Processing
Kent, Washington
LANDAU
ASSOCIATES
C-l
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Figure C-2: Groundwater Extraction System (Landau Associates, 2016 Annual Report)
Legend
@ Extradion Well
© Non-Qperational Extraction Wet!
Natural Attenuation Area
~ Sector
Parcels
Data Source: Esri World Imagery.
Treatment Facility
Discharge Pipe t
Conveyance Lines
Slurry Wall
East Dram
1 Mill Creek
Note
1. Black and wtiite reproduction of this color
original may reduce Its effectiveness ancf
lead to incorrect interpretation.
250
Scale in Feet
500
IA
Landau
Associates
Western Processing
Kent, Washington
Containment Extraction System
Figure
1-3
C-2
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APPENDIX D - PRESS NOTICE
svEPA Cleanup Measures Reviewed for
Western Processing Co., Inc. Superfund Site
We Want to Hear from You
We would tike to make sure we keep
you informed abaut site uctivities. We
would also like to hear from you if you
have information or observations that
can help uui leview If urn. If you have
questions about the site or would like
to participate in an interview, the
review team tmil be on-site in Kent on
January 9, 2018,
Contact Information: Piper Peterson,
EPA Project Manager (206} 553-4951
pgtgrson-pSper(53 epa.gov
To Submit Written Comments:
Email to: peterson.piperfttfepa.gov
Mall to:
Piper Peterson, ECL-122
U.S. EPA Region 10
1200 Sixth Avenue, Suite 900
Seattle, WA 98101
Prior Five-Year Reviews, information
and other documents are available.
Online:
And at these locations:
Kent Regional Library
212 Second Avenue North
Kent, WA 98032 (253-859-3330)
EPA Superfund Record Center
1200 Sixth Ave, Suite 900 - ECL-161
Spattlp, WA 98101 (206-553-4494)
The Sixth Five-Year Review Report
will be ready after September Z018.
What and Why
The U.S. Environmental Protection Agency has started the
Sixth Five-Year Review of the environmental cleanup at the
Western Processing Co., inc. Superfund Site, South lS6,h
Street and Highway 167 (Valley Freeway), Kent, Washington.
EPA reviews sites regularly when contaminants remain above
levels that don't allow for unlimited use and unrestricted
exposure. The five-year reviews ensure that cleanup actions
continue to protect human health arid the environment.
Site Background
I he Western Processing Company operated from 1361 to
1983, when EPA ordered its closure. The company was
originally an animal byproduct and brewer's yeast processor
before transitioning to recycling, reclaiming, treating and
disposing of Industrial waste. Some of the Pacific Northwest's
largest industries hod contracts with .Western Processing to
handle a wide variety of chemicals and waste materials. Soil,
sediments, and groundwater contamination was the result of
operating practices and noncompliance to regulations. -
Western Processing Co., Inc. Cleanup
EPA's long-term cleanup started In 1984, which included;
• Excavation and disposal, by 1991, of 9.5 million pounds of
highly contaminated soils and non-soil material.
• Containment of source contaminants on site with barrier
walls, and a muitilayerecf cap over the southern 13-acres.
• Groundwater treatment to remove contaminants. By
2000 groundwater pollutant levels had been reduced by
9S%, when monitored natural recovery was put In place.
Additional measures completed since 2013:
• Additional sampling and evaluation of sediments In the
East Drain and Milt Creek to ensure protection of bottom
dwelling plant and animal life.
• Adding use restrictions {Institutional controls) to the
property deeds prohibiting wells for drinking water.
TD0 / TTY users may call the f ederal Relay Service at G00-
thfr* npprritnr mimhpr .
D-l
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4>EPA Western Processing Company, Inc.
ft", nit"i! •>. i r? . ! n Kent Site Visit January 8, 2018
Agency
! Cleanup to be Reviewed: The Sixth Five-Year Review of the ervirowiertal
: clear Lp at the Westerr Processing Com par y, Ire. Sipeffu-a Site if Kant is
' ureerway. A former chemical waste processirs arc recyciir\} facility, Westerr
! Processirc harclec some of the Pacific Northwest's largest iraustries. uHii EPA
ioroered its closure
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APPENDIX E - INTERVIEW FORMS
Western Processing Co., Inc. Five-Year Review Interview Form
Superfund Site
Site Name: Western Processing Co., Inc. EPA ID No.: WAD009487513
Interviewer Name: Sarah Alfano Affiliation: Skeo
Subject Name: Christine Kimmel Affiliation: Landau Associates
Subject Contact Information:
Time: 09:10 a.m. Date: 02/07/2018
Interview Location: Landau Associates Edmonds, Washington office
Interview Format (circle one): In Person Phone Mail Other: Email
Interview Category: O&M Contractor
1. What is your overall impression of the project, including cleanup, maintenance and reuse activities (as
appropriate)? Western Processing is an older project with investigation and cleanup activities starting in the
1990s. The cleanup generally included installation of a slurry wall and CAP in the Sector 1 area, installation
of groundwater extraction wells in Sectors 1 through 4, and dredging of sections of Mill Creek and the East
Drain. Groundwater performance data has supported the cessation of pumping from Sectors 3 and 4. The
treatment system operates 24/7 to maintain hydraulic containment goals in Sector 1. Treatment system
consists of an air stripper with a granular-activated carbon polisher. The treatment system is controlled by an
automated programmable logic control (PLC) center that can send out alarms or shut down the system if
conditions are outside of the design settings. Landau Associates has remote access and manual access to the
treatment plant to address alarms. Site reuse activities include the extension of two public roadways crossing
sections of the Site.
2. What is your assessment of the current performance of the remedy in place at the Site? The treatment system
is able to achieve hydraulic containment goals. No evidence of CAP erosion or damage have been observed.
Analytical results indicate compounds of interest have been reported below the reporting limit in the
downgradient monitoring for the MNA area. Additionally, no adverse impacts related to the Site have been
observed in Mill Creek or the East Drain since the dredging activities of these two surface water bodies in the
1990s. This data suggests the current performance of the remedy is sufficient to meet established goals.
3. What are the findings from the monitoring data? What are the key trends in contaminant levels that are being
documented overtime at the Site? Groundwater analytical results from the MNA area indicate the last
compound of interest with concentrations above the laboratory report limit was vinyl chloride in March 2011.
Analytical results from the downgradient MNA area indicate natural attenuation is effective in this area.
Historical concentrations in the background well (13M30A) have decreased to below the laboratory reporting
limit and agencies decided to reduce the sampling frequency from semiannual to annual. Historical elevated
concentrations of zinc in Sector 4 wells resulted in an increase in the sampling frequency from annual to
semiannual at the associated monitoring wells. The elevated zinc concentrations were evaluated as a local and
limited source as elevated zinc concentrations in Mill Creek (directly downgradient of Sector 4) were not
reported. Zinc concentrations in Sector 4 continue to decrease in concentration. Groundwater quality within
Sector 1 (area of site within the slurry wall and under the engineer CAP) continue to have elevated
concentrations of VOCs, SVOCs and metals.
4. Is there a continuous on-site O&M presence? If so, please describe staff responsibilities and activities.
Alternatively, please describe staff responsibilities and the frequency of site inspections and activities if there
is not a continuous on-site O&M presence. The treatment system has a PLC control which will either shut
down the system or send our alarms and continue with operation if operating parameters are outside the
design limits. Landau Associates has a site O&M technician who is remotely connected to the system
continuously (24 hours per day, 7 days a week). The technician will respond to system alarms either remotely
E-l
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or manually. In addition, technician is physically on site approximately 32 hours per week. The technician
conducts daily system checks and conducts equipment inspections/troubleshooting/replacements/repairs. The
technician also conduct site inspections per the plan on a weekly, monthly and quarterly basis.
5. Have there been any significant changes in site O&M requirements, maintenance schedules or sampling
routines since start-up or in the last five years? If so, do they affect the protectiveness or effectiveness of the
remedy? Please describe changes and impacts. Upgrades to a new computer and communications software for
the PLC took place in 2016. The surfactant donor material automatic pump and feeder system were upgraded
in 2017.
6. Have there been unexpected O&M difficulties or costs at the Site since start-up or in the last five years? If so,
please provide details. No.
7. Have there been opportunities to optimize O&M activities or sampling efforts? Please describe changes and
any resulting or desired cost savings or improved efficiencies. System and monitoring program optimization
are reviewed annually and presented in the annual reports. Changes to the monitoring program are based on
analytical results (increase frequency if concentrations increase, decrease if concentrations are stable to
decreasing). Optimization of the treatment system is based on upgrading software or equipment as they age.
1. Do you have any comments, suggestions or recommendations regarding O&M activities and schedules at the
Site? No.
2. Do you consent to have your name included along with your responses to this questionnaire in the FYR
Report? Yes.
E-2
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Western Processing Co., Inc. Five-Year Review Interview Form
Superfund Site
Site Name: Western Processing Co., Inc.
EPA ID No.
: WAD009487513
Interviewer Name: Sarah Alfano
Affiliation:
Skeo
Subject Name: Lindsey Mahrt
Affiliation:
Western Processing Trust
Subject Contact Information:
Time: 12:30 p.m.
Date: 02/13/2018
Interview Location: Western Processing Site
Interview Format (circle one): In Person
Phone
Mail Other: Email
Interview Category: Potentially Responsible Parties (PRPs)
1. What is your overall impression of the remedial activities at the Site? Current remedial activities are
effective and achieving goals of containment by the slurry wall, site cap and groundwater extraction
treatment system.
2. What have been the effects of the Site on the surrounding community, if any? Previous effects were
associated with the Trans Plume Area (downgradient from the Site), but concentrations in groundwater
have decreased to below the reporting limit in this off-site area with the remedial activities and currently
MNA is conducted. Current conditions indicate no effects on the surrounding community from the Site.
The Trust regularly communicates with surrounding property owners via an annual notification letter. The
Trust has been working with the City of Kent's Public Works department to extend a public roadway over
a portion of the Site. As a result of the roadway expansion, site modifications were conducted to some
subsurface utilities and monitoring wells.
3. What is your assessment of the current performance of the remedy in place at the Site? The current
performance of the remedy in place at the Site is effective in maintaining containment. The slurry wall
and treatment system maintain an inward and upward hydraulic gradient at the Site.
4. Are you aware of any complaints or inquiries regarding environmental issues or the remedial action from
residents since implementation of the cleanup? I am not aware of any recent complaints or inquiries from
residents.
5. Do you feel well-informed regarding the Site's activities and remedial progress? If not, how might EPA
convey site-related information in the future? I feel well-informed regarding the Site's activities and
remedial progress.
6. Do you have any comments, suggestions or recommendations regarding the management or operation of
the Site's remedy? I do not have any comments, suggestions or recommendations regarding management
or operation at this time.
7. Do you consent to have your name included along with your responses to this questionnaire in the FYR
Report? Yes.
E-3
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Western Processing Co., Inc.
Superfund Site
Five-Year Review Interview Form
Site Name: Western Processing Co.. Inc.
EPA ID No.: WAD009487513
Interviewer Name: Sarah Alfano
Subject Name: Ching-Pi Wang
Subject Contact Information:
Time: 6:36 p.m.
Interview Location: Bellevue, WA
Affiliation: Skeo
Affiliation: Ecology
Date: February 27, 2018
Interview Format (circle one): In Person
Phone Mail
Other: Email
Interview Category: State Agency
1. What is your overall impression of the project, including cleanup, maintenance and reuse activities (as
appropriate)? A mature site; very well managed. Procedures well known and effective.
2. What is your assessment of the current performance of the remedy in place at the Site? Excellent.
3. Are you aware of any complaints or inquiries regarding site-related environmental issues or remedial
activities from residents in the past five years? None.
4. Has your office conducted any site-related activities or communications in the past five years? If so, please
describe the purpose and results of these activities. None.
5. Are you aware of any changes to state laws that might affect the protectiveness of the Site's remedy? Cleanup
levels may have changed since the effective date of the Consent Decree.
6. Are you comfortable with the status of the institutional controls at the Site? If not, what are the associated
outstanding issues? Yes.
7. Are you aware of any changes in projected land use(s) at the Site? A elevated roadway was built over the Site.
8. Do you have any comments, suggestions or recommendations regarding the management or operation of the
Site's remedy? No.
9. Do you consent to have your name included along with your responses to this questionnaire in the FYR
Report? Yes.
E-4
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APPENDIX F - SITE INSPECTION CHECKLIST
FIVE-YEAR REVIEW SITE INSPECTION CHECKLIST
L SITE INFORMATION
Site Name: Western Processing Co., Inc.
Date of Inspection: 1/9/18
Location and Region: Kent, Washington 10
EPA ID: WAD009487513
Agency, Office or Company Leading the Five-Year
Review: EPA Region 10
Weather/TemDerature: chillv and overcast
Remedy Includes: (Check all that apply)
EH Landfill cover/containment
E3 Monitored natural attenuation
^ Access controls
E3 Groundwater containment
E3 Institutional controls
E3 Vertical barrier walls
EH Groundwater pump and treatment
E3 Surface water collection and treatment
M Other: Surface water monitoring for Mill Creek
Attachments: EH Inspection team roster attached
EH Site map attached
II. INTERVIEWS (check all that apply)
1. O&M Site Manager LindsevMahrt
Name
Proiect Manager
Title
2/19/18
Date
Interviewed EH al site EH al office EH by phone ^
] by email
Problems, suggestions [X] Report attached: See Appendix E
2. O&M Staff Christine Kimmel
2/19/18
Name
Title
Date
Interviewed EH al site EH al office EH by phone ^
] by email
Problems, suggestions [X] Report attached: See Appendix E
3. Local Regulatory Authorities and Response Agencies (i.e., state and tribal offices, emergency
response office, police department, office of public health or environmental health, zoning office,
recorder of deeds, or other city and county offices). Fill in all that apply.
Agency Washington Dept. of Ecology
Contact Ching-Pi Wang Uplands Unit 02/27/2018
Name Supervisor Date Phone No.
Title
Problems/suggestions ^ Report attached: See Appendix E
HI. ON-SITE DOCUMENTS AND RECORDS VERIFIED (check all that apply)
1. O&M Documents
M O&M manual ^ Readily available EH Up to date EH N/A
M As-built drawings ^ Readily available EH Up to date ~ n/a
1)^1 Maintenance logs ^ Readily available EH Up to date EH N/A
Remarks: The site team visited the records/documents area during the inspection.
2. Site-Specific Health and Safety Plan ^ Readily available Up to date EH N/A
1)^1 Contingency plan/emergency response plan ^ Readily available Up to date ED N/A
Remarks: The site team visited the records/documents area during the inspection.
F-l
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3.
O&M and OSHA Training Records
^ Readily available Up to date EH N/A
Remarks: The site team visited the records/documents area durine the inspection.
4.
Permits and Service Agreements
1)^1 Air discharge permit
EH Readily available EH Up to date |_| N/A
~ Effluent discharge
EH Readily available EH Up to date [XI N/A
M Waste disposal, POTW
M Readily available EH Up to date LJ N/A
I-! Other Dcrmits:
EH Readily available EH Up to date [XI N/A
Remarks: On June 26. 2018 the Puset Sound Clean Air Aeencv concluded that this oroicct no lonser
reauires a Notice of Construction Dcrmit because it has a de minimis impact on air aualitv and does
not dosc a threat to human health or the environment.
5.
Gas Generation Records
Remarks:
EH Readily available EH Up to date EH N/A
6.
Settlement Monument Records
Remarks:
EH Readily available EH Up to date E3 N/A
7.
Groundwater Monitoring Records
Remarks:
E3 Readily available E3 Up to date EH N/A
8.
Leachate Extraction Records
EH Readily available EH Up to date E3 N/A
Remarks:
9.
Discharge Compliance Records
M Air ^ Readily available ^ Up to date EH N/A
M Water (effluent) ^ Readily available ^ Up to date EH N/A
Remarks:
10.
Daily Access/Security Logs
EH Readily available EH Up to date EH N/A
Remarks: Boeins Security is doins security checks at the Site for unusual activities.
IV. O&M COSTS
1.
O&M Organization
1 1 State in-house
EH Contractor for state
1 1 PRP in-house
1X1 Contractor for PRP
1 1 Federal facility in-house
EH Contractor for Federal facility
n
2.
O&M Cost Records
1 1 Readily available
EH Up to date
1 1 Funding mechanism/agreement in place
1^1 Unavailable
Orieinal O&M cost estimate: PI Breakdown attached
3.
Unanticipated or Unusually High O&M Costs during Review Period
Describe costs and reasons:
F-2
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V. ACCESS AND INSTITUTIONAL CONTROLS ^Applicable ~ N/A
A. Fencing
1. Fencing Damaged ~ Location shown on site map ^ Gates secured ~ N/A
Remarks:
B. Other Access Restrictions
1. Signs and Other Security Measures ~ Location shown on site map ^ N/A
Remarks:
C. Institutional Controls (ICs)
1. Implementation and Enforcement
Site conditions imply ICs not properly implemented ~ Yes |EI No ~ N/A
Site conditions imply ICs not being fully enforced ~ Yes M No |~1 N/A
Type of monitoring (e.g., self-reporting, drive by):
Self-reporting: office on site
Frequency: Security does checks at the Site for unusual activities and there is a full-time technician on call
and at the Site 3-4 times a week.
Responsible party/agency: PRP
Contact Lindsev Mahrt Boeing
Name Title
Date
Phone no.
Reporting is up to date
IEI Yes
~ No
~n/a
Reports are verified by the lead agency
IEI Yes
~ No
~ n/a
Specific requirements in deed or decision documents have been met
I~1 Yes
|K|No
~ n/a
Violations have been reported
I~1 Yes
~ No
[XI n/a
Other problems or suggestions: ~ Report attached
2. Adequacy ~ ICs are adequate ^ ICs are inadequate ~ N/A
Remarks: Institutional controls still need to be implemented.
D. General
1. Vandalism/Trespassing ~ Location shown on site map ^ No vandalism evident
Remarks:
2. Land Use Changes On Site ~ N/A
Remarks: A new roadway was completed in 2017. construction started in 2016.
3. Land Use Changes Off Site ~ N/A
Remarks:
VI. GENERAL SITE CONDITIONS
A. Roads ^ Applicable ~ N/A
1. Roads Damaged ~ Location shown on site map ^ Roads adequate ~ N/A
Remarks:
B. Other Site Conditions
F-3
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Remarks:
VII. LANDFILL COVERS ^Applicable
~ n/a
A.
Landfill Surface
1.
Settlement (low spots)
~ Location shown on site map
^ Settlement not evident
Area extent:
Depth:
Remarks:
2.
Cracks
1 1 Location shown on site map
Cracking not evident
Leneths:
Widths:
Deoths:
Remarks:
3.
Erosion
1 1 Location shown on site map
Erosion not evident
Area extent:
Depth:
Remarks:
4.
Holes
~ Location shown on site map
^ Holes not evident
Area extent:
Depth:
Remarks:
5.
Vegetative Cover
1X1 Grass
Cover properly established
1^1 No signs of stress
1 1 Trees/shrubs (indicate size and locations on a diagram)
Remarks:
6.
Alternative Cover (e g
armored rock, concrete)
[21 N/A
Remarks:
7.
Bulges
~ Location shown on site map
Bulges not evident
Area extent:
Heisht:
Remarks:
8.
Wet Areas/Water Damage ^ Wet areas/water damage not evident
I~1 Wet areas
1 1 Location shown on site map
Area extent:
1 1 Ponding
1 1 Location shown on site map
Area extent:
I~1 Seeps
1 1 Location shown on site map
Area extent:
1 1 Soft subgrade
1 1 Location shown on site map
Area extent:
Remarks:
9.
Slope Instability
1 1 Slides
~ Location shown on site map
1)^1 No evidence of slope instability
Area extent:
Remarks:
B.
Benches ~ Applicable ^ N/A
(Horizontally constructed mounds of earth placed across a steep landfill side slope to interrupt the slope in
order to slow down the velocity of surface runoff and intercept and convey the runoff to a lined channel.)
F-4
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c.
Letdown Channels ~ Applicable ^
N/A
(Channel lined with erosion control mats, riprap, grout bags or gabions that descend down the steep side
slope of the cover and will allow the runoff water collected by the benches to move off of the landfill
cover without creating erosion gullies.)
D.
Cover Penetrations ^ Applicable ~ N/A
1.
Gas Vents Q Active
1 1 Passive
1 1 Properly secured/locked Q Functioning
1 1 Routinely sampled Q Good condition
1 1 Evidence of leakage at penetration
1 1 Needs maintenance ^ N/A
Remarks:
2.
Gas Monitoring Probes
1 1 Properly secured/locked ~ Functioning
1 1 Routinely sampled ~ Good condition
1 1 Evidence of leakage at penetration
1 1 Needs maintenance ^ N/A
Remarks:
3.
Monitoring Wells (within surface area of landfill)
1^1 Properly secured/locked Functioning
Routinely sampled ^ Good condition
1 1 Evidence of leakage at penetration
1 1 Needs maintenance Q N/A
Remarks:
E.
Gas Collection and Treatment ~ Applicable ^ N/A
F.
Cover Drainage Layer ^ Applicable ~ N/A
1.
Outlet Pipes Inspected Functioning
~ n/a
Remarks:
2.
Outlet Rock Inspected ~ Functioning
[XI n/a
Remarks:
G.
Detention/Sedimentation Ponds ^ Applicable ~ N/A
1.
Siltation Area extent:
Depth: |^| N/A
1 1 Siltation not evident
Remarks:
2.
Erosion Area extent:
Depth:
Erosion not evident
Remarks:
3.
Outlet Works ^ Functioning
~ n/a
Remarks:
4.
Dam ~ Functioning
[XI n/a
Remarks:
H. Retaining Walls ~ Applicable ^
N/A
I. Perimeter Ditches/Off-Site Discharge ^
Applicable ~ N/A
1.
Siltation Q Location shown on site map ^ Siltation not evident
F-5
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Area extent: Depth:
Remarks:
2.
Vegetative Growth Q Location shown on site map Q N/A
Vegetation does not impede flow
Area extent: Tvpe:
Remarks:
3.
Erosion Q Location shown on site map Erosion not evident
Area extent: Depth:
Remarks:
4.
Discharge Structure ^ Functioning Q N/A
Remarks:
VIII. VERTICAL BARRIER WALLS ^Applicable ~ N/A
1.
Settlement O Location shown on site map Settlement not evident
Area extent: Depth:
Remarks:
2.
Performance Monitoring Tydc of monitorine: See FYR bodv text.
1 1 Performance not monitored
Freauencv: 1"! Evidence of breachine
Head differential:
Remarks:
IX.
GROUNDWATER/SURF ACE WATER REMEDIES ^Applicable ~ N/A
A.
Groundwater Extraction Wells, Pumps and Pipelines ^ Applicable ~ N/A
1.
Pumps, Wellhead Plumbing and Electrical
^ Good condition All required wells properly operating Q Needs maintenance Q N/A
Remarks: A colidIc of oiczomctcr casinss had been run over bv a mower. The O&M contractor indicated
that he would replace them as Dart of normal O&M. The damaee did not impact the one ration or
inteeritv of the equipment.
2.
Extraction System Pipelines, Valves, Valve Boxes and Other Appurtenances
Good condition Q Needs maintenance
Remarks:
3.
Spare Parts and Equipment
1 1 Readily available ~ Good condition Q Requires upgrade ~ Needs to be provided
Remarks: Snare Darts were not confirmed but svstem was workins well noon inspection and remedy
failure alarms are in olacc if anvthine fails.
B. Surface Water Collection Structures, Pumps and Pipelines ^ Applicable Q N/A
1.
Collection Structures, Pumps and Electrical
Good condition Q Needs maintenance
F-6
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Remarks:
2.
Surface Water Collection System Pipelines, Valves, Valve Boxes and Other Appurtenances
Good condition Q Needs maintenance
Remarks:
3.
Spare Parts and Equipment
Readily available Q Good condition Q Requires upgrade Q Needs to be provided
Remarks: Snare Darts were not confirmed but svstem was workine well noon insDcction and remedv
failure alarms are in olacc if anvthine fails.
C.
Treatment System ^ Applicable ~ N/A
1.
Treatment Train (check components that apply)
1 1 Metals removal ~ Oil/water separation Q Bioremediation
^ Air stripping Carbon adsorbers
I-! Filters:
Additive (e.e.. chelation asent. riocculcnt):
n Others:
Good condition Q Needs maintenance
Sampling ports properly marked and functional
Sampling/maintenance log displayed and up to date
1 1 Equipment properly identified
153 Ouantitv of groundwater treated annually: Annual averase of almost 3 million eallons
I-! Ouantitv of surface water treated annually:
Remarks:
2.
Electrical Enclosures and Panels (properly rated and functional)
1 1 N/A Good condition Q Needs maintenance
Remarks:
3.
Tanks, Vaults, Storage Vessels
1 1 N/A Good condition Q Proper secondary containment ~ Needs maintenance
Remarks:
4.
Discharge Structure and Appurtenances
1 1 N/A Good condition Q Needs maintenance
Remarks:
5.
Treatment Building(s)
1 1 N/A Good condition (esp. roof and doorways) ~ Needs repair
Chemicals and equipment properly stored
Remarks:
6.
Monitoring Wells (pump and treatment remedy)
Properly secured/locked K! Functioning ^ Routinely sampled ^ Good condition
F-7
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All required wells located ~ Needs maintenance ~ N/A
Remarks:
D. Monitoring Data
1. Monitoring Data
Is routinely submitted on time ^ Is of acceptable quality
2. Monitoring Data Suggests:
Groundwater plume is effectively contained ~ Contaminant concentrations are declining
E. Monitored Natural Attenuation
1. Monitoring Wells (natural attenuation remedy)
Properly secured/locked ^ Functioning ^ Routinely sampled
All required wells located ~ Needs maintenance
Remarks:
X. OTHER REMEDIES
If there are remedies applied at the site and not covered above, attach an inspection sheet describing the physical
nature and condition of any facility associated with the remedy. An example would be soil vapor extraction.
XL OVERALL OBSERVATIONS
A. Implementation of the Remedy
Describe issues and observations relating to whether the remedy is effective and functioning as designed.
Begin with a brief statement of what the remedy is designed to accomplish (e.g., to contain contaminant
plume, minimize infiltration and gas emissions).
The remedy selected for the Western Processing site involves containment of the source contaminants on
site through the use of barrier walls, a RCRA cap, institutional controls and sufficient extraction of
groundwater lo prevent outward migration.
B. Adequacy of O&M
Describe issues and observations related to the implementation and scope of O&M procedures. In
particular, discuss their relationship to the current and long-term protectiveness of the remedy.
O&M procedures are discussed and verified with EPA. Current monitoring appears to be on track for
monitoring the progression oF the remedy and maintaining protectiveness.
C. Early Indicators of Potential Remedy Problems
Describe issues and observations such as unexpected changes in the cost or scope of O&M or a high
frequency of unscheduled repairs that suggest that the protectiveness of the remedy may be compromised
in the future.
Site conditions did not indicate am issues w ith remedy protectiveness.
D. Opportunities for Optimization
Describe possible opportunities for optimization in monitoring tasks or the operation of the remedy.
None noted during this FYR. EPA, the PRPs and O&M contractors regularly communicate and implement
optimization methods over time as needed.
Good condition
~ n/a
F-8
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APPENDIX G - SITE INSPECTION PHOTOS
Treatment plant
Site entrance gate
G-l
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Capped area in Sector 1
Sector 1 Extraction Well, S-6
G-2
-------
Paved trail looking north, along boundary of Sector 1 and the East Drain
East Drain area
G-3
-------
Sector 4, facing south
C3 surface water sampling location in Mill Creek
G-4
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APPENDIX H - DETAILED REMEDIAL BACKGROUND
EPA determined risk to public health with an endangerment assessment, as documented in the 1985 FS Report.
EPA investigated the risks associated with contaminants known or suspected to be carcinogens as well as non-
carcinogens. Assuming that a person worked on site for 40 years, ingestion of on-site soils up to 12 feet deep
would lead to a maximum excess lifetime cancer risk of 2 x 10~4, principally from PCB contamination. There is a
potential excess lifetime cancer risk of 5 x 10~7 associated with the ingestion of on-site surface soils with site
mean concentrations in a future worker scenario. An estimated potential cancer risk of 5 x 10"6 is associated with
the ingestion of soils if the maximum surface concentrations are used. The potential excess lifetime cancer risks
associated with ingestion of off-site surface soils contaminated with PCBs ranged from 9 x 10~6 to 3 x 10"5.
No known domestic or industrial water supplies were affected by the Site. Use of on-site groundwater as a potable
water source for a work place, however, would present an estimated excess lifetime cancer risk of 2 x 101 using
maximum on-site concentrations and 8 x 10"3 using mean on-site concentrations. Cancer risk would increase to an
estimated 5 x 10"1 under a residential scenario with maximum concentrations and 2 x 10"2 with the use of mean on-
site concentrations. Organic compounds contribute most of this excess lifetime cancer risk. A number of average
daily intakes were also exceeded, with an assumed consumption of 0.1 gram of soil per day or 2 liters of
groundwater per day. These contaminant exceedances included lead, chromium, cadmium, toluene, 1,1,1-TCA,
phenol, mercury, and bis(2-ethylhexyl) phthalate.
OU2 - Containment Components (slurry wall, groundwater treatment, cap and VOC plume)
OU3 - Remedial Components Related to Mill Creek and the East Drain
In the fall of 1986, the Trust conducted the soil and soil/waste sampling program and geophysical investigation.
These data were used to determine the limits of excavation of on-site subsurface wastes and off-property
contaminated soils. In January 1987, the Trust conducted the Phase 2 subsurface cleanup. Subsurface remedial
design and construction proceeded at the same time.
Construction activities began in summer 1987. They included excavation and Class 1 RCRA landfill disposal of
over 25,000 cubic yards of highly contaminated soil and sludge as well as installation of the original groundwater
extraction and treatment systems.
Groundwater extraction and treatment in the original system began in October 1988 and ended in 1996. The
system had two major components - air stripping for VOCs, followed by thermally regenerated carbon adsorption
units to capture vapor-phase contaminants. After processing, extracted groundwater was discharged to the local
POTW or reinjected into the ground through the infiltration system. The extraction system had four shallow
groundwater extraction and infiltration areas; these systems were spread across areas of the Site in Sectors 1
through 4 as defined in the FYR Site Background section. Seven barrier monitoring wells were installed west of
Mill Creek.
As remediation progressed, and in compliance with the ESD, many old wells, piezometers, vacuum extraction
wells and infiltration lines were decommissioned. A new main extraction and treatment system was installed in
1996 to provide automated operation of hydraulic containment. The treatment system added 15 new extraction
wells in Sector 1 (wells S-l through S-15). Two extraction wells (U1 and U2) were installed directly west of
Sector 1, outside the slurry wall, in 1993. The new system also added two extraction wells in Sector 4, which was
known to have lower levels of contamination (wells S-l 6 and S-l 7), in 1997 though the ultimate goal of the
remedial system in Sector 4 was to establish passive treatment. The Sector 4 wells stopped operation in
September 1998 (Figure C2). Sector 3 extraction wells (T2, T3 and T4) were discontinued in 1999. Construction
of the new (current) groundwater treatment facility plant finished in 1997. Groundwater extraction continues for
hydraulic containment in the part of the site enclosed by the Sector 1 slurry wall and for isolated area remedy
directly west of the Sector 2 slurry wall. Treated water is discharged under permit to the King County POTW. Off
gas from the air stripper was carbon-treated prior to atmospheric release under a Puget Sound Air Pollution
Control Agency permit. On June 26, 2018 the Puget Sound Clean Air Agency concluded that this project no
H-l
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longer requires a Notice of Construction permit because it has a de minimis impact on air quality and does not
pose a threat to human health or the environment.
Remedial workers installed a 40-foot-deep, 4,400-foot-long slurry wall (Figure 2) in October 1988. It was a field
modification that supplemented the remedial action described in the 1985 ROD and the RODA before issuance of
the 1995 ESD. According to the 2000 Cap O&M Plan, a shallow breach in the slurry wall (250 foot section) was
replaced with sand backfill to an elevation of more than 7 feet. This segment is monitored for groundwater quality
discharge to Mill Creek, (see Figure 2).
The ESD maintained the slurry wall containment remedy and added the construction of a supplemental isolation
wall immediately south of the South 196th Street right-of-way. The isolation wall was constructed using a soil-
cement-bentonite backfill material, which varied from the original slurry wall mix to ensure additional structural
stability required to facilitate plans by the city of Kent to construct an embankment across the Site at the South
196th Street corridor for a major east-west arterial. The isolation wall was designed to continue to protect Mill
Creek and the East Drain from remaining site contamination in Area I and to further reduce the groundwater
pumping necessary to maintain containment. With the isolation wall, the area north of South 196th Street, Sector
4, was segregated from the Sector 1 source area.
Implementation of the monitoring program, including Mill Creek and East Drain surface water monitoring, began
in January 1988. In April 1990, the cleanup achieved interim goals for Mill Creek. EPA issued an Interim Close-
Out Report for the Site in December 1991.
Remediation of East Drain sediments took place in 1993; over 1,140 tons of sediment were disposed of off-site
and gravel borrow was used as backfill. An interceptor system between the Interurban Trail and the East Drain
was constructed; it included a well point extraction system installed in late 1993. The East Drain interceptor
system operated for two years, beginning in November 1994. Use was discontinued in December 1996 as part of
implementation of the containment remediation strategy and the elimination of the groundwater recharge system.
The Trust completed work on the placement of a RCRA cap over Sector 1 (Figure 2) in 1999.
In 1999, EPA approved the transition of the Trans Plume Area (Sector 3) to MNA. In April 2000, extraction wells
within the trans plume were shut off because geochemical conditions in the soils support biological reductive
dechlorination of target VOCs. Monitoring of VOCs (TCE, cis-l,2-DCE and vinyl chloride) in the trans plume
continues. Because Sector 1 field tests indicated that ongoing natural processes (intrinsic bioremediation) would
not be significantly improved in this area by enhanced bioremediation, the technique was used only in Sector 3,
the Trans Plume Area.
The 1995 ESD required treatment of another 5,000 cubic yards of contaminated soil. After the boundaries of the
hot spot were determined to include over 5,000 cubic yards of the most contaminated soil, the areas were
excavated and disposed of off-site.11 The excavation was backfilled with lifts of clean gravel and crushed rock.
Hot spot cleanup activities began in March 1997 and finished in October 1997.
The site decision documents did not select chemical-specific ARARs as performance objectives for the remedy to
achieve. Instead, they developed site-, well- and contaminant-specific CACs, which are based on the historical
concentrations at individual wells or sampling locations per contaminant and not based on MCLs. The Long-Term
Contingency Plan identifies procedures for evaluating containment and actions to be taken if those procedures
indicate a loss of containment (i.e., if CACs are exceeded) and was approved in March 2000, then updated in
2009. The Trust currently maintains the Site.
11 Containing chlorinated VOCs higher than 10 mg/kg, aromatic VOCs higher than 20 mg/kg, TPHs higher than 10,000
mg/kg, and/or metals higher than 25,000 mg/kg.
H-2
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APPENDIX I - DETAILED DATA ANALYSIS
Figure II: Average Groundwater Elevation in Sector 1
19
13
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1-1
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Figure 1-2: Annual Gallons of Groundwater Extracted
4,000,000
3,500,000
3,000,000
2,500,000
fO
0)
>-
a 2,000,000
c
o
ro
ID
1,500,000
1,000,000
500,000
2013 2014 2015 2016 2017
"^"Sector 1 Wells Sector 2 Wells ««™»Total Extraction
1-2
-------
Figure 13: Well 5M4A Historical Levels of HPMO, OPMO
/A rtSb rtSb nSi qJV aV f\V aV q?? (A qJ^ ob nfo nfo n\ nfb nfb rP) nRl fvV fA {A (^1 ^ /V rSo
*yr *&r Sr *sy *5? *fy Sr *5r *5r J? sy sy *sy *Sy Jy jy Jy jy Jy Jy jy Jy ^y jy jct ~cr
jy > nf o>\N ^ o,\^ ^\S /oT <& ^ >
> HPMO » OPMO HPMO CAC OPMO CAC
1-3
-------
>>
£z
°3
n> n>
§ =
CU -n
-t
=T O
5" n
'
N>
2<
Q. <
3" fD
n o
-t -i
=- o
in
~, 2-
s 2" >
n> ^
fD
01
3
Q.
[]
o
w'
D
O
m
<
3
-<_
O
2
o
=.
CL
CD
Jan-87
Jan-88
Jan-89
Jan-90
Jan-91
Jan-92
Jan-93
Jan-94
Jan-95
Jan-96
Jan-97
Jan-98
Jan-99
Jari-00
Jan-01
Jan-02
Jan-03
Jan-04
Jan-05
Jan-06
Jan-07
Jan-08
Jan-09
Jan-10
Jan-11
Jan-12
Jan-13
Jan-14
Jan-15
Jan-16
Jan-17
Jan-18
-------
Figure 1-5: Well 9M44A Historical Levels of Zinc
1000
100
I
c
0
1
4-»
c
d>
u
c
5
10
8 S 8 8
•w
8
8 8 8
T—I
O
Zinc (Total)
-Zinc (Total) Performance Std.
A
Landau
Associates
Western Processing
Kent, Washington
Zinc Concentrations
9M44A
Figure
1-5
-------
Figure 1-6: Well 9M9B Historical Levels of cis-l,2-DCE and Vinyl Chloride
100
c 10
o
o
u
00 00 00
-------
Figure 1-7: Well N3B Historical Levels of Total Zinc
10000
1000
c
.2 ioo
10
m
8! 8 81
Ln«lDf*wOOCTiO«H > >
> > >
> > >
• Zinc
r in id f-. co ci
5 8 8 8 8 8
i p4 fM i *5"
S -N X X 'S. V.
i tH rH i—I rH
-Zinc (Total) Performance Std
o
1
rsj
lCi
00
m
©
©
©
©
©
©
©
©
©
©
rsi
>
>
>
>
>
>
>
rH
1
14
Landau
Associates
Western Processing
Kent, Washington
Zinc Concentrations
N3B
Figure
1
1-7
-------
Table 1-1: Groundwater Elevations (ft., MSL)
Date
SECTOR 1
P10
P12
P20
RP22
P26
RP28
P32
P34
P41
RP42
P48
P49
1M33B
P50
P53
P52
B
A
B
A
B
A
B
A
B
A
B
A
B
A
B
A
3/1/2012
17.13
16.66
17.18
16.66
17.18
15.95
17.55
15.94
17.80
16.96
16.96
16.60
17.04
16.98
17.18
16.37
6/1/2012
16.71
16.47
16.83
16.32
16.76
15,96
17.09
15.97
16.98
16.56
16.54
16.37
16.65
16.55
16.78
16.20
9/7/2012
14.63
14.48
14.62
13.38
14.58
14.31
15.04
14.38
15.31
14.39
14.40
14.30
14.53
14.42
14.64
14.31
12/4/2012
16.79
15.41
16.79
16.61
16.87
15.69
17.28
15.65
16.69
16.59
16.64
16.31
16.73
16.59
16.80
16.05
3/1/2013
16.15
15.30
16.16
15.52
16.29
15,47
16.66
15.51
16.23
15.93
15.99
15.76
16.12
15.97
16.21
15.65
6/4/2013
16.12
15.76
16.21
15.58
16.15
15.54
16.56
15.54
16.78
15.90
15.95
15.79
16.11
15.94
16.17
15.66
9/3/2013
14.29
14.14
14.28
14.11
14.50
14.23
15.16
14.27
14.37
14.16
14.26
14.13
14.33
14.20
14.41
14.05
12/3/2013
15.32
14.34
15.51
14.59
15.52
14.91
16.07
15.13
15.34
15.26
15.43
15.15
15.51
15.31
15.53
15.01
3/4/2014
17.13
16.58
17.17
16.60
17.26
16.35
17.35
16.24
16.93
16.86
16.99
16.68
17.10
16.88
17.13
16.41
6/24/2014
16.12
15.84
16.18
15.30
16.06
15.02
16.24
15.53
15.88
15.58
15.70
15.51
15.80
15.61
15.83
15.40
9/9/2014
14.29
14.28
14.37
13.11
14.41
13.46
14.91
13.61
14.45
14.29
14.31
13.88
14.27
14.20
14.38
13.40
12/3/2014
16.36
15.69
16.42
15.11
16.47
14.87
17.01
14.93
16.59
16.34
16.44
15.71
16.34
16.21
16.37
15.13
3/4/2015
16.66
16.47
16.39
15.66
15.98
15.27
17.13
15.34
16.80
16.53
16.68
15.96
16.56
16.39
16.59
15.52
6/3/2015
15.17
15.08
15.11
14.31
15.53
14.71
15.62
14.50
15.15
15.08
14.88
14.65
15.03
14.91
15.12
14.41
9/1/2015
13.75
13.45
13.85
12.95
13.87
13.25
14.42
13.55
14.38
13.88
13.90
13.78
13.81
13.72
13.93
13.34
12/2/2015
15.99
15.80
16.13
15.00
16.27
14.83
15.47
14.87
16.39
15.91
15.88
15.52
15.99
15.90
16.05
15.18
3/1/2016
18.03
16.60
17.74
17.17
17.37
16.71
17.21
16.67
18.86
17.92
17.32
16.99
18.02
17.97
18.08
17.06
6/1/2016
15.53
15.32
15.58
14.04
14.87
14.80
16.11
15.22
16.84
15.43
15.30
15.18
15.49
15.41
15.63
15.06
9/1/2016
14.24
14.19
14.22
12.75
13.44
14.25
15.94
14.20
15.53
14.05
13.90
13.65
14.17
14.02
14.18
13.77
12/1/2016
16.11
16.02
15.74
15.48
16.17
16.00
16.74
15.11
16.05
15.92
15.97
15.45
16.18
1608
16.22
15.41
3/6/2017
17.27
17.10
17.15
16.99
16.86
16.14
17.78
16.25
17.39
17.12
17.16
16.60
16.04
16.74
17.38
16.64
6/1/2017
16.91
16.76
16.66
15.89
16.43
14.94
17.10
15.91
17.21
16.66
16.66
16.10
15.48
15.41
16.99
16.35
9/1/2017
14.27
14.25
14.27
13.83
13.73
13.57
14.87
14.63
14.46
14.18
13.97
13.68
14.13
14.03
14.30
14.01
10/4/2017
13.97
13.88
13.82
13.51
13.53
14.09
14.44
13.77
14.28
13.96
13.74
13.45
13.89
13.85
14.08
13.72
11/1/2017
15.11
14.42
15.22
14.49
14.75
14.93
15.64
14.32
15.24
15.19
14.97
14.42
15.12
15.67
15.28
14.72
12/1/2017
16.49
14.60
16.63
16.08
16.21
16.17
17.41
15.35
16.72
16.60
16.41
15.76
16.36
16.28
16.70
15.77
Average
Elevation
15.79
15.34
15.78
15.04
15.66
15.05
16.26
15.09
16.10
15.66
15.63
15.28
15.65
15.59
15.84
15.18
Notes
$ = Groundwater elevation in Zone B is lower than Zone A in piezometer pair.
Source: Data compiled from Table B-l in 2017 annual report and Table B-l in 2013 annual report.
1-8
-------
Table 1-1. Hydraulic Gradients (coiit.)
Date SECTOR 1
P54
RPS
P55
P56
N-l
N-l
N-3
N-3
N-5
N-5
N-6
N-6
N-7
N-7
5M4B
5M4A
B
A
B
A
B
A-2
B
A-2
B
A-2
B
A-2
B
A-2
B
A
3/1/2012
17.42
16.04
17.25
16.86
17.32
15.74
17.31
16.33
17.33
16.34
17.28
16.43
17.07
16.82
17.23
14.72
6/1/2012
17.07
16.02
16.81
16.65
16.84
15.75
16.94
16.24
16.88
16.26
16.89
16.28
16.71
16.54
16.78
14.36
9/7/2012
14.92
14.34
14.62
14.57
14.65
14.20
14.80
14.51
14.72
14.37
14.75
14.37
14.50
14.49
14.63
13.13
12/4/2012
17.12
15.80
16.92
16.46
17.14
15.42
17.02
16.09
16.98
16.04
16.74
15.97
17.01
16.71
16.82
15.80
3/1/2013
16.52
15.56
16.34
15.97
16.20
15.17
16.39
15.74
16.31
15.66
16.33
15.71
16.42
16.22
16.22
14.85
6/4/2013
16.49
15.66
16.33
16.02
16.41
15.80
16.37
15.80
16.24
15.70
16.28
15.74
16.41
16.24
16.19
14.11
9/3/2013
14.75
14.25
14.47
14.36
14.55
14.40
14.63
14.37
14.48
14.20
14.56
14.17
14.62
14.49
14.46
13.36
12/3/2013
15.86
15.10
15.62
15.23
15.56
15.11
15.76
15.25
15.57
15.10
15.66
15.11
15.72
15.48
15.51
14.07
3/4/2014
17.50
16.47
17.20
16.66
17.38
16.15
17.28
16.56
17.17
16.37
17.19
16.51
17.00
16.76
17.21
16.02
6/24/2014
16.10
15.52
15.94
15.69
16.05
15.53
16.08
15.70
15.83
15.50
15.97
15.57
15.83
15.66
15.86
14.62
9/9/2014
14.74
13.62
14.47
13.64
14.73
13.54
14.57
13.80
14.45
13.68
14.47
13.56
14.25
13.70
14.46
13.36
12/3/2014
16.70
15.05
16 52
15.54
16 74
14.75
16.59
15.29
16.48
15.24
16.52
15.22
16.26
15.70
16.55
14.85
3/4/2015
16.98
15.42
16.82
15.90
16.83
15.25
16.84
15.66
16.67
15.56
16.75
15.60
16.53
16.02
16.68
14.82
6/3/2015
15.48
14.49
15.26
14.59
15.44
14.23
15.41
15.30
15.16
14.48
15.31
14.51
15.03
14.68
15.22
13.80
9/1/2015
14.18
13.34
13.92
13.49
14.04
13.35
14.23
14.02
13.97
13.52
14.10
13.43
13.81
13.52
13.98
13.54
12/2/2015
16.40
14.95
16.25
14.81
16.40
14.72
16.22
15.30
16.17
15.19
16.26
15.23
15.99
15.54
16.18
14.99
3/1/2016
18.35
16.80
18.38
17.49
18.39
16.71
18.18
17.14
18.22
17.08
18.29
17.15
18.03
17.57
18.06
16.38
6/1/2016
15.94
15.19
15.79
15.30
15.90
15.21
15.75
15.32
15.63
15.14
15.77
15.12
15.47
15.19
under
construction
under
construction
9/1/2016
14.49
13.88
14.33
14.03
14.48
13.96
14.36
13.97
14.22
13.86
14.33
13.83
14.05
13.83
14.21
13.57
12/1/2016
16.62
15.32
16.42
15.75
16.50
14.94
16.39
15.44
16.36
15.39
16.27
15.49
16.13
15.76
16.32
15.05
3/6/2017
17.68
16.38
17.66
16.95
16.53
14.97
17.55
16.61
17.49
16.57
17.41
16.69
17.15
16.73
16.34
15.01
6/1/2017
17.24
16.22
17.24
16.63
16.48
14.93
17.12
16.40
17.03
16.34
17.01
16.47
16.91
16.61
16.29
14.98
9/1/2017
14.58
14.08
14.42
14.20
14 48
14.02
14.43
14.16
14.31
13.98
14.29
14.02
14.17
13.99
14.22
13.35
10/4/2017
14.30
13.81
14.17
13.97
14.28
13.78
14.17
13.90
14.09
13.79
14.10
13.74
13.89
13.75
14.20
13.30
11/1/2017
15.49
14.77
15.44
15.04
15.59
14.66
15.43
14.92
15.37
14.77
15.34
14.76
15.03
14.80
15.46
14.35
12/1/2017
16.93
15.56
16.86
16.20
16.95
15.25
16.78
15.80
16.77
15.75
16.63
15.80
16.45
16.10
15.50
15.24
Average
Elevation
16.15
15.14
15.98
15.46
15.99
14.91
16.02
15.37
15.92
15.23
15.94
15.25
15.79
15.50
15.78
14.47
Notes
$ = Groundwater elevation in Zone B is lower than Zone A in piezometer pair.
Source: Data compiled from Table B-l in 2017 annual report and Table B-l in 2013 annual report.
1-9
-------
Table 1-2: Annual Vinyl Chloride Emissions, 2013 to 2017
Yt'iir
1
-------
APPENDIX J - DETAILED ARARs REVIEW TABLES
There were no site-wide cleanup standards established for groundwater contaminants. The only contaminant
cleanup standard established in the RODA required a cleanup level of 70 ng/L for the cis-1.2-DCE oil-site plume.
The site decision documents did not select chemical-specific ARARs as performance objectives for the remedy to
achieve. Instead., they developed site-, well- and contaminant-specific C'AC'S, which are based 011 the historical
concentrations at individual wells or sampling locations per contaminant and not based on MCLs.
The 1986 Consent Decree states that the remedial goal for trans-1.2-DCE should be at or below 70 pg/L, Since
the cis isomer of the 1.2-DCE was determined to be the relevant isomer since that time, compliance with the i .2-
DCE performance standard is currently interpreted to occur when the total 1.2-DCE {cis- plus trans-)
concentrations remain at or below 70 tig/L. A review of current federal groundwater MCLs indicate this lemedial
goal remains valid.
Table J-l presents groundwater contaminants at the Site and their respective federal MCLs.
I aide.! 1: ARAKs
2(ir Mel.
(ug/L)b
VOCs
Clorobenzene
100
eis-l,2~DCE
70
trans-l,2-DCEc
100
Vinyl chloride
2
Notes:
a. Groundwater coniamiiiante listed 111 Table 2-2 of the 2016 Annual
Samp]ilia Report.
b. National Priniaiy Dunking Water Regulations available ai.
httns: \\-w\v.et)a ao\. eroiuid-water-and-dnnking-water luitional-
orimaiT-di'inkmE-water-resiilations (accessed 3/8/201S),
c. The 19So Consent Decree stares that the remedial goal for rrans-L2
DOE should be at ot below "0 u a L. Because The cis isomer of the
1,2-DCE was determined to be the relevant isomer since that time,
compliance wiih the 1,2-DCE performance standard is cnnently
interpreted 10 occur when the total 1,2-DCE icis>- phis trans-)
concentrations remain at or below 70 (.ig/L.
Hg/L = micrograms per liter
The 1986 Consent Decree designated AWQC for freshwater as the basis for surface water monitoring. The data
review section of this FYR discusses current surface water quality in relation to these AWQC. Table 1-2 presents
surface water contaminants monitored at the Site and their respective AWQC.
J-l
-------
Table J-2: Surface \\ ;i(er ARAR
:nr lc(U-!;il
ma f .i"
Cadiiiiuin
0.72
Lead
2.5
Nickel
52
Zinc
120
Cliromnun (Total)
74c, lld
Copper
NA
Notes:
a. Surface water contaminants listed in Table 2-5 of the 2016 Annual
Sampling Report.
b. Federal Ambient Water Quality Criteria available at:
httos: Vwww.eoa.cov \voc national-reconimended-water-aualitv-
c ri t eria -a cma tic - li f'e-cri teri a-ta b 1 e (accessed 3/8/2018),
c. There is no AWQC for total chromium, but there is an AWQC for
chromium III. which is included in the table.
d. There is no AWQC for total chromium, but there is an AWQC for
chromium IV. which is included in the table.
pg/L = micrograms per liter
NA = Nor Applicable sno AWQC designated)
J-2
-------
APPENDIX K - SCREENING-LEVEL RISK REVIEW
The 19S5 ROD selected off-site soil excavation levels based on exceedances of Acceptable Daily Intakes (ADKs
for noiicaiciiiogens or the 1 x J 0excess cancer level for carcinogenic contaminants of concern (COCs). The only
COC where the ADI was exceeded was lead, and PCBs exceeded the 1 x 10° excess cancer level. For PCBs. the
ROD selected a site-specific excavation level of 2 mg kg. For on-site soils, the ROD selected a site-specific
excavation level of 50 mg/kg. Table K-l evaluates the anient validity of these cleanup levels using 2017 FPA
composite worker RSLs: the RSLs incorporate anient toxicity values and standard default exposure factors.
Composite worker RSLs are used because the anticipated future use of the Site is industrial coinmereial.
Based on the evaluation, the excavation level for off-site PCBs remains valid because it is equivalent to a cancer
risk, that falls within EPA's acceptable risk management range of 1 x 10 6 to 1 x lu4 and is below the target risk
level for off-site soils of 1 x 10"-. The excavation level for on-site PCBs remains valid because it is equivalent to a
cancer risk that falls within EPA's acceptable risk management range of 1 x 106 to 1 x 104
Table K-l: Review of Sol Excavation Levels - Human Health Direct Contact
<¦()<¦
Noil
I.VM-I
ui m Lui
* r>mpt>'.i!ts Wi.rUf K>.l.'una Ksi)
KMi'"
iiy
ifla/aiil
iii-m)
< ;iHcet ISascil
Ksi.
tin' Risk)'1
Nr>I! ( :i!tO l KSl.
111^ l.Dl*"
' •¦:..! PCBs
*7®
0.94
-
2.1 x 10-®
NA
Total PCBs
50f
0.94
5.3 x 1Q5
Notes:
a. EPA's composite worker RSLs. dated November 2017. available at
http s'.ii semspub. epa. gov/work/HQ/19703 3.pdf (accessed 4/19/18).
b. Cancel risk calculated using the following equation, based on the fact that RSLs are derived based oil 1 x 10'
# risk: cancer risk = i remedial goal + cancer-based RSL'i • 10 ".
c. Noncancer I-IQ calculated using the following equation: HQ = (remedial goal +¦ noncancer RSL).
J. Soil excavation levels derived from ADI values ni the 19S5 FS.
Noncancer-based level:
Excavation level = ADI (.ma day) + i ingestion rate x conversion factor for kg/gm)
= ADI + (0.1 gaidav x 0.001 kg 'gnu
e, EPA selected the excavation level as 2 mg-kg for off-site soils rather than the 1 x 10~3 risk-based level of 7
mg. kg calculated as follows:
Excavation level = Target risk + Cancer potency factor s s lifetime daily intake x exposure fraction x
conversion factor kg am)
= Target risk - Cancer potency factor x ("0.00082 gm-day/kg x 0.41 x 0.001 kg/gm)
1. EPA selected rise on-site exca\ atiou level for PCBs to be 50 uig kg.
NA = nol applicable
- = EPA has not finalized a carcinogenic or nonearcinogenic toxicity value for this compound.
For groundwater, the site decision documents did not select risk-ba^ed cleanup levels as performance objectives
for the remedy to achieve. Instead, they developed site-, well- and contaminant-specific C'ACs. winch are based
oil one of the following: background concentrations, statistically based values (nonparametric prediction interval
or a control chart limit) or the analytical reporting limit. None of the C'ACs were based on health-based criteria.
To determine if the CACs are protective of human health, the CACs were compared to EPA's Regional Screening
Levels
-------
the noncaucer hazard quotient (HQ) of I, The CAC for lead is the background concentration thus. Superfimd
remediation cannot remediate to concentrations below background. The (VAC for ICE is equivalent to the
enforceable drinking water standard, the MCL. EPA is currently reviewing the MCL fpr TCE and in the interim
the current MCL remains valid. Except for EIPMQ and OPMO. all indicators had an established toxicity value for
carcinogenic effects or ncncancer effects, EPA has not yet established health-based toxicity values for IIPMO and
OPMO. since these compounds are a relatively new class of antibiotics use to treat human health infections. Thus,
these two compounds are not considered hazardous substances at this time. Based on this screening-level risk
evaluation, even though four indicator chemicals exceed the RSLs (TCE. vinyl chloride, cliromium and lead) the
CACs remain valid because there are no current completed exposure pathways.
Tabic K 2: Risk Evaluation of Human Health based Groundwater CACs
Indicator Chemical
2009
Maximum
CAC
MCL
(Mfa)
EPA Tap Wafer RSL* fpg/L)
Future Groundwater I'se
1 x 10* Risk
HQ=1.0
Risk*
Noncancer HQd
Benzene
5 rl
5
0.46
33
1.1 x I©-3
0.2
Chlorobenzene
5 rl
100
-
78
-
0.06
Chloroform
5 rl
80
0.22
97
2,2 x irs
0.05
1,2-DieHorobenzeiie
10
600
-
300
-
0.03
1,1 -DicJhloroetliane
5 rl
-
2.8
3800
1.8 x 10*
0.001
1,1 -Dicliloroetliyleiie
5 rl
7
-
280
-
0.02
cis-U-DCE1'
23 cc
70
-
36
-
0.64
Trails-1.2-
dichloroethylenc1 (trans-1,2-
IX'F)
5 rl
100
-
360
0.01
Ethylbenzcne
5 rl
700
1.5
810
3.3 x lO"4
0.01
Methylene chloride
5 rl
5
11
110
4.5 x ir7
0.05
Styrene
5 rl
100
-
1200
-
0.004
Tetrachloroethylenc (PCE)
5 rl
5
11
41
4.5 s 1G"7
0.12
Toluene
5 rl
1000
-
1100
-
0.004
IsLi-TricHoroetlxane (1.1,1-
TCA)
5 rl
200
-
8000
-
0.001
Trichlorocthyleiie (TCE)
5 rl
5
0.49
2.8
1.0 xlO"3
1.8
Vinyl chloride b
1« c
2
0.019
44
1.0 110 J
0.43
O-xykne
i 1
10000
-
190
-
0.03
M. p-xylcne
Sri
10000
-
190
-
0.03
Mriitl-
Cachmurn
6.8 bg
5
-
9.2
-
0.74
Chromium
44 np
100
0.035
44
l.Oxlfr3
1.0
Copper
129 bg
1300
-
800
-
0.16
Lead
90 be
15
-
15
-
6.6
Nickel (as soluble salts)
40 bg
-
-
390
-
0.10
Zinc
227 bg
0
-
6000
-
0.74
Ox a z<» )i di n d
HPMO
370 cc
-
-
-
-
-
OPMO
1600 cc
-
-
-
-
-
K-2
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Indicator Chemical
2009
Maximum
CAC
(Mg L)
MCL
0»fTL)
EPA Tap Water RSLb {«•>. !_)
I 5 10 6 Risk
HQ=1.0
Future Groundwater Use
Risk'
Noncancer HQa
a. The current EPA RSLs. dated May 2018, are available https://mw.em eovtektegional-screeMng-levels-rsk-gemeric-
tables (accessed 8 23 2018).
b. Hie cancel risks were calculated using the following equation, based oil the fact that RSLs are derived based oalx 10"6
risk:
Cancer risk = (2009 Maximum CAC Tap water Cancer RSL) 10 s
c. Tlie noncancer hazard index was calculated using the following equation:
Hazard Index = (2009 Maximum CAC - Tap water Non-cancer RSL)
d. Class of antimicrobial agents or antibiotics used to treat infections however, screening criteria have not been established
for these compound*.
HQ = noncancer hazard quotient
Bold = cancer risk exceeds 1 x 10"4 or the noncancer HQ of 1,0'
be - site background concentration
cc — based on a statistical control chart
np — based on a statistical nonparametiic prediction interval
EL - laboratory reporting limit.
- = EPA has not finalized ;i carcinogenic or noncarcinogenic toxicity value for this compound
The Lead cleanup goal of 1.000 mg kg is based oil outdated guidance. EPA OLEM Directive 92S5.6-56 {May 17,
2017) recommends using the Adult Lead Methodology' to assess lead risks from soil for the non-residential
Superfimd sire scenarios. The recommended soil Preliminary Remediation Goal is 1.050 mgkg which
correspond* to a target blood lead concentration of 5 iig.decilitei. Tliis updated goal is less stringent than the
original cleanup goal, therefore the soil cleanup goal is still protective (Table K-3).
Table K-3: Screening-level Risk Evaluation of Soil Cleanup Goals - Industrial Scenario
coc
If 88 ROD
Cleanup
Goal
(mg/kg)
EPA Industrial Soil PRGa
(mg/kg)
Lead
1,000
1,050
.Votes:
* PR.G is based on guidance from the 2017 Update to the Adult Lead
Methodology's Default Baseline Blood Lead Concentration and
Geometric Standard Deviation Parameters
PRG = Preliminary Remediation Goal
K-3
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APPENDIX L - ANNUAL PROPERTY NOTICE EXAMPLES
Example of Letter Type A
Jinuary 10, 2017
QI243-MCM705
'..j,,!.-™,) Pi>uri- C
(b)(6)
Shoreline, WA 98177
RE: Ymt proper : o > . "3; ¦ ¦, Kent, WA 9M32
Dear Property Owner;
As vou mav be aware a cfeanuo 0f laroundwaier and soil contamination has been ongoing since 1983 at the Western
Processing Supeffoni site near your propetty In Kent* Washington Atlhotigh the majority of contnninatioft has been
removed from the siier low concentrations of heavy metals and volas ile organic compounds remain in the pwadwafcr
in the vlctnity of the Western Processing property, This groundwater does not pose & threat to human health because if
Is not a source of linking water and other exposure routes do not normally exist Cleanly efforts continue to reduce the
extent and level of residua! conisiisin#®ri through groundwater extraction and treatment, source control, and natural
bio*kgradation processes.
White it is highly untiketv thai a property owner such m you would pump groundwater from ifcis area for *ny purpose
or use due to the presence or a public who supply system to the area, socli pumping could yield contaminated
groundwater, cause spreading of the residual contamination, art interfere with the continuing cleanup effects at
Western Processing. Accordingly! we provide this notification annually to property owners « fte vicinity of Western
Prpcessioj * a roninder that King County regulation prohibit you front installing, well for the extraction and use of
groundwater if there is ¦ suitable public water supply within I mile of your property. Because the City of lew
operates a public water supply system within the area, you should use the Kent water system for your water needs.
You bum contact King County, the Wash ingjon Sate Department of ecology, ami the U,8, Environmental Protection
Agency if you wish to install a well on your property.
These measures and this reminder are for your continued safety during cleanup efforts at the Western fnoctssifig. site and
to orevent interference with cleanup o Derations We lareatlv aDoreciate vour cooperation in suonort of our cleanup efforts
Yow property address and mailing address have been otafwesi from public records available through King County*
Washht&ton If vou do not own the referenced orooerrv: if we do not have voiirconrect name fjm«effv address, or rnailinc
" * • 14 J ® " " ¦* Blfc" ¦# I'te I * »*¦ ^ J1* * ****%* * > J | * * * * *• HW4 ¦ **¦ * %" J vW wb S *hi B< m I "Wfiialp* %j WimSfcX# " ¦ Pw 8 "* * ¦ Jy
aiittis; or if you ottorwte Whm ttat th» lelter w« sent I® yon in error, pleue notify Michael Cteasos of Ae Wetwtn
Processing Trust In addition, if vou have tenants or other entities utilizing or managine the referenced Drooettv nlease
5 B « 9 %#><#*.• 6 » J S5 Jf ^ I T %r IV 1 =v= i ^ E ^ & ***** 4#*** * j |' ^
ftrW'iKl a copy of this letttr to Ae« or, if you prefer, oemm MM 6k«son m fen-iwd this tafcmiitioB,
Thank you for your aneia ion 10 Ms maner. If you have any questions or comraenu, phase contact Michad GknKon.oryou
may contact Cling-M Wiagofthe Wtshington Stair Department of Ewiss® at (415) 649-7134.
Michael Gkeasot
Western l>roc«ing Trwst Fund II
2A¥«ii«SoBili
Kent, WA M032
(206)290-6571
L-l
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January I®, 211?
GI243-MG-I70I
Example of Letter T vpe B
City of Kent
400 W Gowe St.
Ken I, WA 91032
RE: Ya«r property at (b) (6)
Street, Knit, WA »8»32
Dear Property Owner
As you may be aware, i cleanup of groundwater ami soil contamination has been ongoing since 1913 at the Western
Processing Supertax! site near ywr property in Kent, Washington. Although the majority of contamination has been
removed from Ac site, low concentrations of Navy metals and volatile organic compounds remain »the groundwater
in the vicinity of the Western Proceuing property. This groundwater does not pose a threat to human health, because
it Is mi a source of linking water and other exposure routes do not nomwlty exist Cleanup efforts continue to reduce
the extent and level of tcsidual contamination through groundwater extraction and treatment, source control, and
natural btodegredation processes.
While H is highly unlikely that a property owner such u you would pump groundwater from this area for any purpese
or use due to the presence of a public water supply system in the area, $uch pumping could yield contaminated
groundwater, cause spreading of the residual eontainmation, and Interfere with the continuing cleanup efforts at
Western Processing. Accordingly, we provide this notification annually to property owma in the vicinity ®f Western
Processing as t reminder that King County vegutatioiH prohibit you from tosiallinf wells for the extraction and use of
groundwater if there is a suitable public water supply within I mile of your property Became the City of Kent
operate* i public mm supply system wihto tie «», pm should use the Keel water system for your water needs..
Yon man contact King County, the Washington Stale Department of Ecology, and the US, Environmental protection
Agency if you wish to install a well on your property.
In addition, monitoring wells, dean cover soil, or other remediation matures art located on your property is pan of
the (mediation hwplemcnted at Ike Western Processing site. Any excavation, earthwork. or ether property
improvement wotk that has the pottrtiat to disturb these features should be carefWly planned and coordinated with
the Western Processing Trust. Disturbance to these features, must be promptly repaired
These measures and (his reminder are for your continued safety during cleanup efforts at the Western Processing site
and » prevent interference with cleanup operations. We greatly appreciate your cooperation in support of ow cleanup
efforts. Your property address and mailing address have been obtained from public records available through King
County, Washington. If you do not own tie referenced property; if we do not have your correct name, property
address, or milling address; or If yoti otherwise believe that this letter was seat to yon in error, please notify Michael
Glcasoct of the Western Processing Trust. In addition, if you live tenants or other entities utilizing or managing the
referenced properly, please forward ¦ copy of this later to them or, if you prefer, contact Michael Cietson to forward
ills information.
Thank you for your attention to this maner. If you have any questions or comments, please contact Michael
Gleasoo, or you may contact Ching-Pi Wang of (.he Washington State Department of Ecology at (423) 649-7134.
Western Processing Trust Fund II
20015 72** Avenue South
Kent, WA 91032
(206)290-6576
Sincerely,
L-2
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APPENDIX M - EXISTING REGULATIONS RESTRICTING LOCAL
GROUNDWATER USE
As stated in the 1999 Institutional Controls Work Plan, the following existing regulations restrict groundwater use
at the Site and the surrounding areas:
King County Health Department regulations
These regulations provide that sites greater than 5 acres in size can install a well for the extraction and use of
groundwater only if there is no suitable public water supply within 1 mile of that property. The City of Kent
currently operates a public water supply network with water lines available to the area from both 72nd Avenue S.,
immediately south of the site, and S. 196th Street, which intersects the northern part of the site.
Washington State Department of Ecology
Ecology requires a water right permit for groundwater withdrawals of 5,000 gallons per day or more (RCW
90.40.050). Ecology also requires permits to drill any type of well. This permit is enforceable by fines against
drillers, who would generally not assume the risk of drilling a well without a properly obtained permit. Ecology
would not issue such permits based on the King County Health Department regulations discussed above.
Zoning and land use
The existing and probable future zoning and land use in the vicinity of Western Processing consists of commercial
and light industrial operations that are likely to have little or no need for the withdrawal of groundwater for their
operations. This, together with the enforceable King County Health Department regulations, suggests that the
chance of groundwater development by business operations consistent with zoning and land use patterns around
Western Processing is negligible.
Environmental permitting
Any type of land development, including most modifications to existing facilities in the vicinity of Western
Processing, would be subject to building permits, grading permits, Shorelines Management Act, State
Environmental Policy Act, and potentially other permitting processes. These provide yet another checkpoint
against the use of groundwater within the vicinity of Western Processing.
M-l
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