United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R10-89/019
September 1989
&EPA
Superfund
Record of
Northside Landfill, WA
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•50272-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/ROD/R10-89/019
3. Recipient'* AcceMlon No.
4. Title and Subtitle
SUPERFUND RECORD OF DECISION
Northside Landfill, WA
First Remedial Action - Final
5. Report Date
09/30/89
7. Author)*)
8. Performing Organlz>tlon Rept No.
9. Performing Organization Name and Addrew
10. ProJecVTuk/WorfcUnHNo.
11. Contnct(C) or Gr«nt(C) No.
(C)
(G)
12. Sponsoring Organization Name and Addrew
U.S. Environmental Protection Agency
401 M Street,.S.W.
Washington, D.C. 20460
13. Type of Report & Period Covered
800/000
14.
15. Supplementary Note*
16. Abstract (Limit: 200 word*)
The 345-acre Northside Landfill is in a mixed residential and agricultural area, in the
northwest corner of the city of Spokane, Spokane County, Washington. The landfill has
been used since the 1930s by the city of Spokane and a variety of private and public
haulers for disposal of residential and light commercial refuse. The landfill is
into four disposal units; a refuse unit, a grease skimmings unit, an old open
unit and a sewage sludge unit. Only the refuse unit is active. However, this unit
scheduled to close by 1992. The western one-third of the landfill lies over the
large Spokane Valley-Rathdrum Prairie Aquifer (SVRPA). The SVRPA was designated as a
sole source of water supply for the Spokane-Coeur d'Alene area by EPA in 1978.
Investigations conducted in 1981 and 1983 indicated the presence of volatile organic
compounds (VOCs) beneath the site and in offsite residential wells located northwest of
the landfill. The city immediately supplied the 19 affected residences with bottled
water and has since extended municipal water lines to the area. The primary contaminants
of concern affecting the ground water are VOCs including PCE, TCA, and TCE. In
addition, iron and lead exceed the secondary drinking water standards offsite.
(Continued on next page).
17. Document An*ly*l* a. Descriptor*
Record of Decision - Northside Landfill, WA
First Remedial Action - Final
Contaminated Media: gw
Key Contaminants: VOCs (PCE, TCA, TCE), metals (lead)
b. Mentifien/Open-Ended Term*
c. COSATI Reid/Group
18. Availability Sutement
10. Security CU*» (Thl* Report)
None
20. Security Clu* (Thi* Pige)
None
21. No. of Page*
96
22. Price
(See ANSI-Z38.18)
SM Instruction* en /town*
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-35)
Department of Commerce
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9. Performing Organization Name and Mailing Address. Give name, street, city, state, and ZIP code. List no more than two levels of
an organizational hlerachy. Display the name of the organization exactly as It should appear In Government Indexes such as
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10. Project/Task/Work Unit Number. Use the project, task and work unit numbers under which the report was prepared.
11. Contract/Grant Number. Insert contract or grant number under which report was prepared.
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15. Supplementary Notes. Enter information not included elsewhere but useful, such as: Prepared in cooperation with ... Translation
of... Presented at conference of... To be published In... When a report Is revised, Include a statement whether the new
report supersedes or supplements the older report
16. Abstract Include a brief (200 words or less) factual summary of the most significant Information contained In the report If the
report contains a significant bibliography or literature survey, mention It here.
17. Document Analysis, (a). Descriptors. Select from the Thesaurus of Engineering and Scientific Terms the proper authorized terms
that Identify the major concept of the research and are sufficiently specific and precise to be used as Index entries for cataloging.
(b). Identifiers and Open-Ended Terms. Use Identifiers for project names, code names, equipment designators, etc. Use open-
ended terms written In descriptor form for those subjects for which no descriptor exists.
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18. Distribution Statement. Denote public releasability, for example "Release unlimited'', or limitation for reasons other than
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16. Abstract (Continued)
EPA/ROD/R10-89/019
Northside Landfill, WA
The selected remedial action for this site includes immediate closing of the inactive
units of the landfill with final closing of the active portion by 1992; capping all
disposal units; constructing an interim pumping and treatment facility for ground water
remediation until landfill closure effectively reduces contaminants to below the MCLs,
followed by offsite discharge of treated water into the Spokane River; ground water
monitoring; providing an alternate supply of drinking water to residences affected by the
contaminated ground water; implementing institutional controls to restrict site access,
protect the landfill cap, and prevent construction of domestic wells in the contaminated
plume; and controlling landfill gas emissions. The estimated present worth cost of this
remedy is $41,500,000 to $51,500,000, which includes an annual O&M cost of $489,000 for
10 to 30 years!
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RECORD OF DECISION,
DECISION SUMMARY, AND
RESPONSIVENESS SUMMARY
FOR
FINAL REMEDIAL ACTION
NORTHSIOE LANDFILL SUPERFUNO SITE
IE,
SEPTEMBER 1989
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION 10
1200 SIXTH AVENUE
SEATTLE, WASHINGTON
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RECORD OF DECISION
REMEDIAL ALTERNATIVE SELECTION
FINAL REHEDIAL ACTION
NORTHSIDE LANDFILL SOPERFUND SITE
SPOKANE, WASHINGTON
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RECORD OF DECISION
REMEDIAL ALTERNATIVE SELECTION
SITE NAME AND LOCATION
Northside Landfill
Spokane, Washington
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action for the
Northside (North) Landfill site In Spokane, Washington, developed in
accordance with CERCLA, as amended by SARA, and to the extent practicable, the
National Contingency Plan. This decision is based on the administrative
record for the site, which is attached as Appendix B.
The state of Washington "has been involved closely with this decision.
Although the state's comments on the Proposed Plan are incorporated into this
Record of Decision (ROD), EPA has not yet received the state's concurrence
letter.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from this site, if
not addressed by implementing the response action selected in this ROD, may
present an Imminent and substantial endangerment to public health, welfare, or
the environment.
DESCRIPTION OF THE SELECTED REMEDY
The remedy documented by this ROD Is designed to protect public health
and the environment by preventing the consumption of groundwater which has
been contaminated by solvents from the landfill, and by reducing the migration
of those contaminants. Major elements of the selected remedy include:
0 requiring closure of the landfill as soon as possible;
0 capping the landfill after closure to minimize entry of
precipitation into the wastes;
0 pumping and treating the contaminated groundwater to reduce the
amount of contaminants entering the aquifer (this is a protective
measure which will operate until the closure and capping actions
prove effective in reducing aquifer contamination);
0 monitoring groundwater around the landfill and downgradient from it
to track changes in the extent and nature of the contamination plume;
0 providing an alternate supply of drinking water to those residents
whose well supply has become contaminated by the landfill;
0 enacting administrative restrictions to protect the landfill cap,
closed units, and monitoring wells from unauthorized access, and
address construction of domestic wells in the contaminant plume; and
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controlling landfill gas emissions (the city of Spokane is. '
developing a separate Landfill Gas Management Report to address this
issue).
For the purposes of selecting a remedy, the North Landfill site was
divided into five units. Four of these units are areas of the landfill. They
are the refuse, skimmings, old burn, and sewage sludge units; only the refuse
unit is currently In use. The fifth unit is the aquifer beneath the site.
The selected remedy is the same (capping) for each portion of the landfill.
The cap will be designed to reduce landfill leachate generation and thus
control future contamination of the groundwater beneath the site. Part of the
site is still actively receiving refuse and will continue to do so until
December 31, 1991. Beginning In 1992, all refuse will be diverted either to
a planned waste-to-energy facility, new units to be constructed at Northside,
or an alternate landfill site. Closure of the non-active units may begin
after approval of the closure plan, with final closure beginning in 1992 after
the existing refuse unit is no longer receiving wastes.
The pump and .treatment remedial action will actively control the source
of groundwater contamination leaving the landfill. This will allow the
contamination to naturally attenuate and restore its usefulness.
DECLARATION
The selected remedy is protective of human health and the environment,
attains federal and state requirements that are applicable or relevant and
appropriate for this remedial action, and Is cost-effective. This remedy
utilizes permanent solutions and alternative treatment (or resource recovery)
technologies to the maximum extent practicable for this site. However,
because treatment of the wastes at the site was not found to be practicable,
this remedy does not satisfy the- statutory preference for treatment as a
principal element of the remedy. The size of the landfill and the existing
state of technology rendered treatment and/or excavation not feasible for this
site.
The selected remedy does not require placement of RCRA hazardous wastes
either on or offsite. Therefore, the Land Disposal Restrictions do not apply.
Because this remedy will result in hazardous substances remaining on-site
above health-based levels, a review will be conducted within five years after
commencement of remedial action to ensure that the remedy continues., to provide
adequate protection of human health and the environment.
/Date Reg 1ona1 Admi n1s trator
Environmental Protection Agency
Region 10
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DECISION SUHMARY
FINAL REHEDIAL ACTION
NORTHSIDE LANDFILL
IE,
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TABLE OF CONTENTS
Page
Decision Summary
Site Location and Description 1
History of Site Operations 6
Site Investigations and Remedial Activities .7
Enforcement Activities 8
Community Relations 9
Site Characteristics 11
Summary of Site Risks 16
Description of Alternatives 27
Comparative Analysis of Alternatives 35
The Selected Remedy 52
Statutory Determinations 56
Conclusion 60
Appendices
A. Responsiveness Summary A-l
•
B. Administrative Record Index B-1
ii
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LIST Of FIGURES
LIST OF TABLES
1. Vicinity Map: Northside Landfill 2
2. Landfill Units 3
3. Distribution of PERC: June 1986 5
4. Distribution of PERC: June 1988 13
1. Range of Contaminant Levels On and Offsite 12
2. Estimated Doses and Incremental Cancer Risks from 17
Average Exposure Due to Use of an Offsite Well
3. Estimated Doses and Incremental Cancer Risks from 18
Exposure Due to Use of the Most Contaminated Offsite
Wells
4. Estimated Doses and Incremental Cancer Risks from 19
Exposure Due to Use of the Most Contaminated Onsite
Well
5. Chemical-Specific ARARs and TBCs for Organic 32
Contaminants Found at the North Landfill
6. Summary of Alternative Evaluation Criteria 36
7. Cost Summary 48
iii
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DECISION SUMMARY
SITE LOCATION AND DESCRIPTION
The Norths ide Landfill, also known as the North Landfill, is located In
the northwest corner of the city of Spokane, In Spokane County, Washington.
The landfill covers 345 acres and 1s bounded by Nine Mile Road and the bluff
of Five Mile Prairie (Figure 1). It is surrounded by a chain link fence, with
one main gate; structures near the gate include a gatehouse, truck weighing
station, two equipment storage areas, and a caretaker's trailer.
The landfill is located in a mixed residential and undeveloped
agricultural area. The Agency for Toxic Substances Disease Registry review
found there are 20 homes with approximately 65 residents in the area of the
contaminated groundwater plume from the landfill.
The Spokane Val ley-Rathdrum Prairie Aquifer (SVRPA) lies beneath
approximately the western one-third of the landfill. This aquifer was
designated as a sole source of water supply for the Spokane-Coeur d'Alene area
by the U.S. Environmental Protection Agency (EPA) in 1978, under the 1974
Federal Safe Drinking Water Act (Public Law 93-523). Highly permeable sands
and gravels deposited by glacial meltwater streams (gladofluvial deposits)
make up the majority of the aquifer, with subordinate lenses of clay and zones
of cobbles. The remainder of the landfill is directly underlain by
unsaturated glaciofluvial sands and gravels with less permeable glacial lake
deposits and basalt occurring at depth.
The climate In the area Is semlarid, with 17.2 Inches average
precipitation at the Spokane Airport and about 15 inches at the landfill.
Most of the precipitation falls during winter as snow. Average annual
snowfall at the airport Is 58 Inches. Frost typically penetrates from 12 to
18 Inches Into the ground; however, during unusually cold winters it may
penetrate 36 inches or more.
Identification of Landfill Units
The Northslde Landfill site was divided into sections for evaluation in
the feasibility study. The Identification of these different areas was based
on past disposal practices and the nature and extent of contamination. These
areas are referred to as* "Units" and were evaluated on the basis of the
different technologies that were applicable to each unit. The units are
(Figure 2):
Refuse Unit
Skimmings Unit
Old Burn Unit
Sewage Sludge Unit
Aquifer Unit
Refuse Unit — The portion of the landfill still receiving solid waste (since
1962). It measures 115 acres and had received approximately 4,400,000 cubic
yards of waste as of December 1987. Small quantities of cleaning solvent
sludges are assumed to be interspersed throughout this waste. Refuse enters
this unit at the current rate of 500-600 tons/day.
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NORTHWEST SPOKANE AREA
WASHINGTON
Contaminant Plume
Figure 1
Vicinity Map
Northside Landfil
7.
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a i
luis'n
pilal
*-*\
4-
U-
1 1,
(. L,
=.
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— I—
1,
1
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,
^
3000 «MO 'JOOO
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• EXISTING GAS MONTOWNQ PROBE
A EXIsflNQGROUNDWATERMOMTOfllNQWEU.
(WELL ELEVATION)
SURVEY MONUMENT
NOTES. SM Figuf • I -9 toe tot M «nd toil boring
locMont witiin tkmmjng mill
11000.J
Aquttof um not trunm.
MW BandMW-R«Mf*convdMd togupcobM
SLUDGE UNIT'"
(«ACRES)
OLD BURN UNIT
(38 ACRES)
REFUSE
(115 ACRES)
• I
-!
UW-O (167571)
• '* V & ' . -; \' •", V VA\NiL>^^
^"^ww^^^^^+f^
VM ' ' \ ' • v—orsSf'V'
Flj-urc 2
LANUI ILL UNITS
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Skimmings Uni t—The portion of the landfill that received grease skimmings
from the city's wastewater treatment plant from about 1972 until 1987. The
disposal pit. area is approximately 3 acres in size; if the landfill area
between the pits is included in calculating the area, it increases to
9 acres. For the purposes of cost calculations, the smaller area was used.
Using an average depth of 5 feet for skimming deposits, this area contains
about 24,000 cubic yards of skimmings. The skimmings contain low
concentrations of tetrachloroethylene (PERC), trichloroethylene (TCE), and
1,1,1-trichloroethane (TCA), which are volatile organic compounds (VOCs).
Old Burn Unit—The landfill section in which refuse was subject to open
burning between 1930 and 1962. It Is 38 acres In size, contains approximately
3 million cubic yards of ash, noncombustible material, and burned refuse and
is covered with several feet of soil (some small areas of ash are exposed at
the road cuts). The area has naturally revegetated with grasses and weeds.
Data presented in the Feasibility Study (FS) do not indicate the presence of
VOCs.
Sewage Sludge Unit—The section of the landfill which received digested sludge
from the city's wastewater treatment plant from about 1972 until 1983. It is
approximately 8 acres In size and 25 feet deep. It Is covered with soil and
natural vegetation. Data in the FS indicate that volatile organics probably
would not leach from this area because a high percentage of the VOCs are
destroyed or volatilized In the wastewater treatment and sludge digestion
process.
Aquifer Unit - That portion of the Spokane-Valley Rathdrum Prairie Aquifer
(SVRPA) that contains concentrations above detection limits of PERC that has
leached from the landfill into the groundwater. Currently that limit is
defined by the 1 ug/1 concentration curve. PERC has been detected further
away from the landfill than any other contaminant (see Figure 3).
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LEGEND
5 —— PERC ISOCONCENTRATION
CONTOUR (pg'O
t—t— INFERRED ISOCONCENTRATION CONTOUR
• MONITORING WEU SAMPLED FOR PERC
H JUNE 1986
( ) JUNE 1966 PERC CONCENTRATION Ipg/l)
• NOT DETECTED
J
IMSirilliUllUN OK PCHC
JUNC K»«l
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HISTORY OF SITE OPERATIONS
The Northside Landfill site has been used since the 1930s by the City of
Spokane and a variety of private and public haulers for disposal of
residential and light commercial refuse. The City of Spokane has a total
population of about 180,000, and the landfill serves some suburban customers
as well. It is one of two publicly owned landfills still In operation in
Spokane County. Several other landfills have been closed In recent years;
three of these—Colbert, Greenacres, and M1ca—are also Superfund sites. Due
to closures, Northside is currently receiving almost 70 percent of the
county's nonrecycled waste (about 600 tons per day). The city and county
together are planning to construct a waste-to-energy facility, to be
operational by late 1991, to alleviate the waste disposal capacity problem.
After review of city records and an assessment of the solid waste stream, it
has been determined by EPA and the City of Spokane that industrial wastes have
not been sent to the Northside Landfill and are, for the most part, handled by
other facilities located in the County. There are very few historical records
of waste quantities or type received at the landfill. A waste stream analysis
was done by reviewing previous studies of waste type and disposal practices of
all businesses in the city.
The site became the city's primary refuse dump about 1931. During the
1930s and Into the 1940s, the northeast portion of the site was an open dump
where the refuse was burned. A refuse incinerator was constructed in the
1940s, but open burning continued at the site until at least the late 1950s.
For a number of years, the ash from this municipal incinerator as well as
bottles, cans, and other noncombustlbles were the major components of the
waste deposited at the site. Any refuse that did not burn was left uncovered.
Between 1962 and 1973, landfill ing practices began in the central area of
the site. This Involved placing the wastes on the existing grade and covering
them with earth scraped or dug from nearby areas. This refuse was not burned
and received periodic cover.
The trench method of landfilllng began in 1973, adjacent to Nine Mile
Road. The trench method of landfilling Involves digging deep trenches (as
much as 20 feet below existing grade), filling them with waste, and then
covering this with dirt excavated from the trenches.
Currently, cover material Is excavated from ridges located along the
north side of the site.- This material is being used to cover new refuse and
to add lifts (step-like plateau areas) on top of the older, lower, western
portion of the landfill. These lifts (about 20 feet thick) have contained the
refuse to a total depth of about 125 feet.
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SITE INVESTIGATIONS AND REMEDIAL ACTIVITIES
In 1981, the City of Spokane hired C^M Hill, an engineering firm, to
investigate the hydrogeology and water quality in the area of the site.
CH2M Hill installed four onsite groundwater monitoring wells in the fall of
1982; samples taken from these wells indicated the presence of low
concentrations of volatile organic compounds (VOCs). One year later, in
October 1983, Investigations revealed the presence of VOCs in off site
groundwater from samples taken from residential wells located northwest of the
landfill. The dty Immediately supplied the 19 affected residences with
bottled water and approved the extension of municipal water lines to the
area. All of the affected residences were located in the Pine Meadows housing
development just northwest of the city limits; all were connected to the city
water supply by November 1983. Spokane representatives completed water line
connections to 16 additional residences in the Pine Meadows area in spring
1984. The municipal system is now serving additional residential areas
northwest of the landfill that are not being impacted by the contamination
plume.
In the spring of 1985, the City of Spokane Installed nine additional
wells to monitor water quality at the site. There are currently 10 offsite
and 11 onsite groundwater monitoring wells. The remedial activities conducted
after this effort are described under enforcement activities In the next
section.
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ENFORCEMENT ACTIVITIES
Contamination of the SVRPA was noted by the late 1970s and was traced to
Northside Landfill, but no enforcement actions were taken at that' time. The
city applied for a solid waste disposal permit in 1979 and the Spokane County
Health Department granted it, though they recommended stepped-up groundwater
monitoring and measures to keep hazardous waste out of the landfill. The only
recorded permit violation was in July 1988, when the health district notified
the city that gas levels at the landfill were too high.
On October 15, 1984, EPA proposed the Northside Landfill for inclusion on
the National Priorities List (NPL). In March 1985, EPA and the Washington
State Department of Ecology (Ecology) signed an agreement whereby Ecology
assumed the lead responsibility for remedial actions at Northside. The site
was formally listed on the NPL on June 10, 1986 (51 Federal Register 21054).
The City of Spokane is the sole identified Potentially Responsible Party
(PRP) for Northside Landfill. The city was notified of its potential
liability by EPA in September 1985 and by the state of Washington in January
1986.
In February 1986, Ecology and the City of Spokane signed an agreement .
authorizing the city to conduct the remedial investigation for the Northside
Landfi.ll site. The agreement included conditions that would bring the city
into compliance with federal regulations regarding investigations of hazardous
waste sites. .The City of Spokane submitted a draft Remedial Investigation
(RI) report in October 1986 to EPA, Ecology, the Washington Department of
Social and Health Services, and the Spokane County Public Health District.
Based on that report, dry cleaning sludges and wastewater treatment plant
grease skimmings were identified as possible sources of chemical contamination
in the landfill waste. City representatives presented Information concerning
the investigation and related Issues at a public meeting on December 11, 1986.
The city submitted a draft Feasibility Study (FS) report in early 1987.
In this report, the city evaluated various alternatives for addressing
contamination problems in three areas: contaminated refuse, treatment plant
skimmings, and groundwater.
After reviewing the draft FS, EPA and Ecology asked the city to install
additional monitoring wells. These wells were required to help characterize
the extent of the contamination plume in the aquifer. The city and Ecology
were unable to come to an agreement on the proposed wells and Ecology
requested that EPA take the lead. Subsequently EPA signed a consent order
with the city on March 16, 1988, to complete the wells and undertake future
remedial actions. With the signing of this order, EPA became directly
responsible for overseeing activities at the site.
Under the terms of the EPA-Spokane Consent Order, the city revised and
resubmitted the draft RI and FS documents in August 1988. A public meeting on
the results of the draft RI was held in September 1988; the public meeting on
the draft FS and proposed EPA recommended action (proposed plan) was held
March 15, 1989. A public comment period was held on the RI/FS from March 1 to
March 31, 1989.
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COMMUNITY RELATIONS
The specific requirements for public participation at Northside Landfill
under CERCLA, as amended by SARA, include releasing the RI/FS and proposed
plan to .the public. This was done in February 1989. Both documents were
placed in the administrative record and information repositories. Notice of
the availability of these documents, plus notice of a public meeting on the
proposed plan and public comment period was published in the Spokesman-Review
on February 28, 1989. A public comment period was held from March 1 to
March 31, 1989. A public meeting was held on March 15, 1989, with
presentations given by EPA, Ecology and the City of Spokane. Comments from
the public were taken and are summarized in the Responsiveness Summary portion
of this .document.
Community relations activities have maintained effective communication
between the citizens living near the landfill, the city and EPA. Discussion
between the different groups for Information purposes and suggestions on the
project has been open. The actions taken to satisfy the requirements of the
federal law have also provided a forum for citizen involvement in reaching the
remedial action decision.
EPA's community relations activities at the site Include the following:
9 August 1987: EPA and Its contractor, EBASCO, conducted community
interviews to develop a community relations plan.
0 November 1987: EBASCO submitted to EPA the Community Relations Plan
for the site. The plan was distributed to the Information
repositories at the main Spokane Library and the Spokane Engineering
Services Library. The administrative record was placed in the
Spokane Library.
May 12, 1988: EPA distributed a fact sheet to persons on the
mailing list. It explained the Consent Order between the City of
Spokane and EPA for completing the Remedial Investigation.
July 1988: EPA distributed a Revised Community Relations Plan which
provided up-to-date information on the site and future opportunities
for public Involvement.
0 September 1, 1968: EPA distributed a fact sheet announcing a public
meeting on the Remedial Investigation.
0 September 15, 1988: EPA hosted an Informational meeting for the
public to explain results from the Remedial Investigation. Three
members of the public attended.
0 February 28, 1989: EPA distributed the proposed plan fact sheet to
the persons on the mailing list. This fact sheet outlined the RI/FS
results; it also explained EPA's preferred plan and how It differed
from that recommended in the FS. The fact sheet also announced a
public meeting on March 15, 1989, and the dates of the public
comment period. A public notice describing the proposed plan and-
the public meeting was placed in the Spokesman-Review.
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March 1. to March 31: . Public comment period on Proposed Plan.
March 12, 1989: A second notice for the public meeting held on
March 15 appeared in the Spokesman-Review.
March 15, 1989: EPA held a public meeting to explain the RI/FS
results and the proposed plan. About 30 people attended the
meeting; 10 citizens gave verbal comments. A record of the meeting
Is part of the Responsiveness Summary, Appendix A.
May 2, 1989: A fact sheet summarizing the public comments and EPA's
response was distributed to the persons on the mailing list. Those
who commented during the comment period also received a copy of the
complete Responsiveness Summary. Copies of the Responsiveness
Summary were placed In the Spokane Public Library and Spokane's
Engineering Services Library.
10
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. SITE CHARACTERISTICS
Hydroqeology
The Northside Landfill, situated about one-half mi.le east of the Spokane
River, overlies a portion of the Spokane Valley-Rathdrum Prairie Aquifer
(SVRPA). This aquifer was designated as a sole-source water supply for the
Spokane-Coeur d'Alene area by the EPA in 1978, under the 1974 Federal Safe
Drinking Water Act (Public Law 93-523). Highly permeable sands and gravels
make up the majority of the aquifer, along with lenses of clay and zones of
cobbles and boulders.
The installation of monitoring wells has confirmed that the refuse area
is primarily over the SVRPA although the aquifer boundary has not been
precisely defined. The aquifer surface is about 80 feet below the level of
Nine Mile Road and is over 200 feet thick at the deep monitoring well at the
northwest corner of the landfill. Hydraulic measurements help to define the
aquifer as a large and very productive aquifer which has average linear flow
velocities from 25 to 30 feet per day under parts of the landfill.
Groundwater Contamination
Volatile organic compounds and metals have been detected in the
groundwater beneath and northwest (downgradient) of the landfill.
Tetrachloroethylene (PERC) and trlchloroethylene (TCE) are present in the
aquifer both onsite and dffsite at levels that exceed the EPA's existing or
proposed Maximum Contaminant Levels (MCLs) for drinking water. Iron,
manganese, and lead also exceed drinking water criteria in several wells.
Table 1 gives a range of groundwater contaminants found in and around the
landfill since monitoring began In 1983. The locations of the wells is shown
on Figure 4.
PERC and Iron are the only two contaminants consistently present in
offsite wells at concentrations In excess of any existing or proposed
standard. PERC is listed as a Group 82 carcinogen (i.e., probable human
carcinogen based on evidence from experiments with animals). In addition, its
offsite concentrations were also higher than concentrations of other compounds
and it has been recorded In the greatest number of wells. Thus, PERC was
selected as the primary compound of concern for this site.
Iron was found in concentrations above the Secondary Drinking Water
Criteria for taste and odor. Because this does not present a health or
environmental risk, Iron was not considered a contaminant of concern.
Six other compounds In addition to PERC that have known health effects
have been detected in offsite wells: chloroform, TCE, 1,1,1-trichloroethane
(TCA), 1,2-(trans)dichloroethylene, 1,1-dlchloroethane, and vinyl chloride.
Of these six compounds, only TCE and TCA were detected frequently enough and
at concentrations sufficient to make predictions of concentrations at points
of exposure. Therefore, TCE and TCA were also selected as compounds of
concern for the purpose of evaluating public health risks associated with this
site. Vinyl chloride was detected once in one offsite well and two onsite
wells at detection limits. Although vinyl chloride is an end product for
chlorinated solvents, its detection only once at the Northside site is not
sufficient to select it as a contaminant of concern.
11
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TABLE 1
RANGE OF CONTAMINANT LEVELS
ON AND OFF-SITE
Groundwater
N)
Organlcs (ug/1)
Chloroform
TCA
TCE
PERC
1,2-Transdichloroethylene
• ,1-Dkhloroethane
Vinyl Chloride
Methylene chloride
Acetone
Toluene
Benzene
Ethylbenzene
Xylenes (o & m)
On-slte wells
ND -
NO -
ND -
ND -
ND -
ND -
ND -
<5
15
22
33
2
22
1
ND
ND
ND
ND
ND
ND
ND
not tested
not tested
not tested
not tested
not tested
not tested
Off-site wells
6
15
9*
28
6
6
1
<.01 -
ND -
.001 -
16.8 -
15.8 -
4.7 -
<.001 -
<.001 -
.8 -
6.5 -
<.002 -
<.002 -
18.02
.055
.399
160
109
17.8
<.010
<.005
66.5
48.4
1.97
.005
ND -
ND -
.001 -
41.6+
44.6+
7.0+
ND -
<.01 +
2.1 -
18 -
(.01 -
<.002 -
.37
.016
1.165
.043
64.8
44
.162
.004
Soil
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Air
ND
ND
ND
not tested
ND
ND
ND
1.7 -
3 -
ND -
ND
ND
ND
5.7
6
.6J
Gas
ND
ND - .30
not tested
not tested
not tested
ND
ND - 1.1
ND .3J
ND - .8J
ND - 1
ND - .6
ND - 1.3
ND - .8
Inorganics (tested for In groundwater only)(mg/l)
Iron
Lead
Zinc
Calcium
Magnesium
Sodium
Copper
Cyanide
Chloride
Sulfate
Manganese
Cadmium
ND = none detected
J = estimated trace value
* one Inconsistent result of 22 (Masgal well); suspected sample bottle contamination
+ only sampled for once, from a single well
-------
LEGEND
5——PERCISOCONCEN1RMION
CONTOUR l^g/l)
T—T—INFERRED ISOCONCENTHATIONCONTOU
• MONITORING WELL SAMPLED FOR PERC
IN JUNE 1988
( ) JUNE 1988 PERC CONCENTRATION Otg/l)
* NOT DETECTED
Figure A
OISIIUIIIIIION OF PERC
JUNt I9H8
-------
PERC, ICE, and TCA are degreasers or solvents that have been used for
many years In a number of household products, dry cleaning agents, and
industrial metal cleaners. The feasibility study states that cleaning solvent
sludges from dry cleaners and other small businesses are probably the major
source of these compounds in the landfill wastes. Analyses of dry cleaning
sludges from establishments which used the landfill have shown as much as 2
percent PERC by weight, as well as lower concentrations of other VOCs. It has
been calculated that about 300 tons of dry cleaning sludges were taken to the
site.
The city stopped accepting dry cleaning wastes at the landfill in 1983.
This was after EPA began regulating dry cleaning sludges as a hazardous waste
In 1980. Prior to 1983 the dry cleaning wastes were a part of the normal
waste stream and were distributed throughout the refuse disposal areas.
Available Information Indicates that all of the dry cleaners in Spokane
generate less than 1000 kg/mo of RCRA hazardous wastes and are therefore
classified as Smajl Quantity Generators, who are allowed to dispose small
amounts of hazardous wastes in landfills. Any dry cleaning wastes that
arrived prior to 1962 would have been subjected to open burning which would
have reduced the concentration of VOCs. Those arriving between 1962 and 1983
are in the 115 acre main landfill area currently in use.
Another source of VOCs is the liquid waste pits located In the upper,
eastern portion of the landfill. These pits received grease skimmings from
the wastewater treatment plant. Skimmings have not been dumped In these pits
since 1987. Analyses of the skimmings and the contaminated soils in the pits
have shown up to 3,400 ug/kg PERC, 1,200 ug/kg TCA, and 6,800 ug/kg TCE.
Another type of solid waste that was disposed of at the site was digested
sewage sludge from the City of Spokane wastewater treatment plant. Sewage
sludge disposal began In 1977 when the wastewater treatment plant converted to
secondary treatment. Until mid-1979, several disposal techniques were used,
Including mixing the sewage sludge with the Incoming solid waste, lagoon1ng,
and land spreading. In 1979, a trench disposal operation was devised in the
northeast portion of the landfill. It consisted of a series of 6-foot deep
trenches in alternating directions on successive lifts. Between 1978 and
1980, an average of 305 cubic yards per day of digested sewage sludge,
containing at least 16 percent solids, was deposited in the landfill. The
sludge was stabilized with ferric chloride and lime at 13 and 46 percent,
respectively, on a dry weight basis. In 1978 the pH of the sludge ranged from
10 to 11. In late 1983.the sewage sludge disposal operation at the landfill
was discontinued. The sewage sludge appears to contain small amounts of
contaminants. Analyses of sewage sludge conducted in 1987 and 1988 did not
detect any PERC or TCE, although TCA and several other VOCs were detected in
some samples.
Contami nant M1qratlon—Groundwater
Since November 1982, the City of Spokane has conducted a major
groundwater sampling program in and around the Northside Landfill. Currently,
the program consists of quarterly monitoring of 11 onsite and 11 offsite
monitoring wells and 13 domestic wells. Figure 4 shows wells that are sampled
on a regular basis. The groundwater quality data collected by the City are
presented in the Supplemental Remedial Investigation Addendum dated November
1988.
14
-------
More than 500 groundwater samples from more than 75 wells have been
tested for organic and Inorganic contamination by the City of Spokane since
contamination of the SVRPA by VOCs was discovered in November 1982. In
addition, nearly 300 groundwater samples from about 35 wells have been tested
for inorganic contamination. Throughout this period, the concentrations of
contaminants, particularly for organic contaminants, in individual wells have
remained relatively constant.
The RI/FS states that the area of the PERC contaminant plume has remained
relatively constant between 1983 and the present, indicating that the
concentration In the aquifer has reached a dynamic equilibrium or "steady
state" condition. Figures 3 and 4 give PERC concentration contours for June
1986 and June 1988, respectively. The FS report Indicates that, although PERC
is moving downgradient within the aquifer, the concentration reduction
mechanisms of adsorption, dispersion, degradation, and dilution balance the
landfill releases, which results in the observed stable contaminant
distribution.
15
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SUMMARY OF SITE RISKS
Persons who may use contaminated groundwater from the area of the
Northside Landfill as their only source of water were identified as the
population at risk of adverse health effects. The primary routes of exposure
to contaminants in groundwater are ingestion, inhalation of volatile
constituents, and dermal absorption. Tetrachloroethylene, (PERC),
trlchloroethylene
-------
TABLE 2
ESTIMATED DOSES AND INCREMENTAL CANCER RISKS FROM
AVERAGE EXPOSURE DUE TO USE OF AN OFFSITE WELL
TCE
Concentration (ug/1)
Risk
PERC
Concentration (ug/1)
Risk
Total Excess Risk
Oral
1
3 x 10-7
3
4 x 10-6
1 x 10-5
Inhalation
1
3 x 10-7
4 x 10-6
Dermal
1
1 x 10-9
2 x 10-8
(Sum of risks due to three
exposure routes and both
chemicals)
17
-------
TABLE 3
ESTIMATED DOSES AND INCREMENTAL CANCER RISKS FROM
EXPOSURE DUE TO USE OF THE MOST CONTAMINATED OFFSITE HELLS
oo
Pel low Well
TCE
Concentration (ug/1)
Risk
PERC
Concentration (ug/1)
Risk
Total Excess Risk
oral
5
2 x 10~6
2*8
4 x I0~5
8 x I(T5
Average Casq
inhalation
5
2 x NT6
28
4 x ID'5
(Sum of risks
dermal
5
1 X 10'5
28
2 x 1
-------
TABLE 4
ESTIMATED DOSES AND INCREMENTAL CANCER RISKS FROM
EXPOSURE DUE TO USE OF THE MOST CONTAMINATED ONSITE WELLS
VD
Well MH-M
TCE
Concentration (ug/1)
Risk
PERC
Concentration (ug/1)
Risk
Total Excess Risk
oral
13
4 x 1(T6
14'
2 x HT5
5 x IO'5
Average Case
inhalation
13
4 x l
-------
contaminated onsite wells were identified as monitoring wells MW-M and MW-T.
At the MW-M Well, the average concentrations of PERC, TC£, and TCA are 14, 13,
and 6 ug/1, respectively. The highest concentrations of PERC, TCE, and TCA
observed at this well are 26. 22, and 15 ug/1, respectively. MW-T Well was
sampled only once in June 1988. The concentrations of PERC, TCE, and TCA
detected in this well are 33, 4, and 18 ug/1, respectively.
Four other organic compounds—chloroform, 1,2-transdichloroethylene,
1,1-dichloroethane, and vinyl chloride—were detected on a few occasions in
less than 30% of the offsite wells. Vinyl chloride, for example, was analyzed
on only one occasion and was detected only in the Pel low, MW-M, and MW-T Wells
at 1 ug/1. Chloroform was sampled for regularly in each well, but was
detected in only 3 wells, on one occasion in each well (maximum concentration
= 6 ug/.l detected in the Costello Well. October 1987). These chemicals were
therefore not evaluated in the risk assessment, because they were detected so
infrequently and at very low concentrations relative to their toxicity (often
near the detection limit of 1 ug/1). However, because of the weight of
evidence and cancer potency of vinyl chloride and chloroform, the maximum
likely additional cancer risks due to exposure to these chemicals are
discussed in the uncertainty section.
Iron was the only inorganic compound detected in offsite wells that
exceeded drinking water standards. The ambient water quality criterion for
iron (0.3 mg/1) Is based on taste, odor, and staining properties. This
compound was not considered a contaminant of concern because there are no
known health effects from ingestion of iron at the concentrations measured.
Exposure Assessment
The population at greatest risk of adverse health effects are those
people who potentially use the groundwater In the area of the Northside
Landfill as their only source of drinking water. The primary routes of
exposure to contaminants in groundwater are ingestion, Inhalation of volatile
constituents, and dermal.absorption.
A. Exposure Point Concentrations
As mentioned above, groundwater monitoring data from Appendix D of the
Supplemental RI Addendum were used to derive exposure point concentrations.
Appendix D contains organic chemical concentration data for samples taken
during the period of September 1983 through June 1988 for onsite and offsite
wells. Most wells were .sampled periodically during this period and so a time
series of data is available for these wells. Some wells were sampled only
once or very Infrequently during this period.
A great number of analytical results are reported as below a detection
limit of 1 mlcrogram per liter or as below an unspecified detection limit.
When calculating exposure point concentrations for PERC, TCE and TCA, these
"non-detectable" results were treated in the following manner. If a result
was reported as less than 1 microgram per liter, then it was assumed that the
concentration equals one-half of the detection limit, i.e., 0.5 ug/1. If a
result was reported as less than an unspecified detection limit, it was
assumed that the detection limit is 1 microgram per liter, and that the
concentration equals 0.5 ug/1.
20
-------
1) Average Exposure Due to Use of Offsite Wells
In this scenario, It was assumed that persons would be exposed to
groundwater contaminants at a level equal to the arithmetic mean of all the
observations (N = 523) averaged over time for all of the offsite.wells
(total = 61). For PERC, TCE, and TCA, these concentrations are 3, 1, and
1 ug/1, respectively.
2) Exposure Due to Use of the Most Contaminated Offsite Well(s)
For this scenario, for each of the three chemicals of concern, the
offslte well which showed the highest average concentration was identified.
The average concentration at a well is defined as the arithmetic mean of the
time series of concentration data.
For PERC, the Pel low Well showed the highest average concentration (28
ug/1 based on 24 observations). The average concentration of PERC at all
other offslte wells is less than 9 ug/1.
For TCE as well, the Pel low Well showed the highest average concentration
(5 ug/1 based on 24 observations). The average concentration of TCE at all
other offsite wells is less than 2 ug/1.
For TCA, the Volkman Well showed the highest average concentration (7
ug/1 based on 31 observations). The average concentration of TCA at the
Pel low and Shaw Wells was 4 ug/1. At all other offsite wells, the average
concentration of TCA Is less than 2 ug/1.
The Pel low and Volkman Wells were therefore identified as the most
contaminated wells. Risks associated with the exposure to groundwater
contaminants from the both these wells are evaluated assuming two levels of
exposure. The first level is the average concentration at the wells. These
concentrations are given In the paragraphs above.
The second level considered is the highest concentration observed at the
wells. At the Pellow Well, the highest observed concentrations of PERC, TCE,
and TCA are 38, 8, and 10 ug/1, respectively. At the Volkman Well, the
highest observed concentrations of TCE and TCA are 7 and 15 ug/1,
respectively. PERC was assumed to be at a concentration of 0.5 ug/1, as it
was not detected in this well.
3) Exposure Due to Use Of the Most Contaminated Onsite Wells
For this scenario, for each of the three chemicals of concern, the onsite
well which showed the highest average concentration was identified. The
average concentration at a well is defined as the arithmetic mean of the time
series of concentration data.
For PERC, the MW-T Well showed the highest average concentration (33 ug/1
based on 1 observation in June 1988).
For TCE, the MW-M Well showed the highest average concentration (13 ug/1
based on 16 observations).
For TCA, the MW-T Well showed the highest average concentration (18 ug/1
based on one observation in June 1988).
21
-------
The MW-M and MW-T Wells were therefore identified as the most
contaminated wells. Risks associated with the exposure to groundwater
contaminants from both these wells are evaluated assuming two levels of
exposure. The first level is the average concentration at the wells. These
concentrations are given in the paragraphs above.
The second level considered Is the highest concentration observed at the
wells. At the MW-M Well, the highest observed concentrations of PERC, TCE,
and TCA are 26, 22, and 15 ug/1, respectively. At the MW-T Well, the only
observed concentrations of PERC, TCE, and TCA are 33, 4, and 18 ug/1,
respectively.
B. Calculation of Dose
For each chemical of concern, an average daily dose was calculated for
two routes of exposure, Ingestion and dermal contact. A dose from inhalation
of volatile organic compounds, such as the chemicals of concern, was not
calculated directly, as the various models for estimating risks from
inhalation exposure have not been critically reviewed by the EPA, Region 10.
Therefore, in this risk assessment it was assumed that the inhalation risks
are equal to (average case) or two times (upper-bound case) the risks from
ingestion of 2 liters of water per day, according to current EPA, Region 10
guidelines (USEPA, 1989a).
The average daily dose (mg/kg/day) via ingestion was calculated as
follows:
dose - concentration of contaminant (mg/1) x intake rate (I/day) / 70 kg
body weight
For all exposure scenarios, a person was assumed to ingest 2 liters of
contaminated water every day for a lifetime. Absorption was assumed to be
100* for all chemicals.
The average daily dose from dermal absorption of contaminants while
bathing was calculated as follows:
dose = C x CF x Kp x SA x EF / 70 kg body weight
where,
C = concentration of contaminant (mg/1)
CF « conversion factor (10~3 l/cm^)
Kp - dermal permeability constant (cm/hr)
SA « body surface area contacted (cm2)
EF - frequency (hr/day)
For all the volatile contaminants, a dermal permeability constant of 8.4
x 10~4 cm/hr was used In the above equation (USEPA, 1989c). The body
surface area exposed to water while bathing was assumed to be 18,000 cm2 for
the average adult (USEPA, 1989b). For each exposure scenario, a person was
assumed to bathe for a duration and frequency equivalent to one-half hour
every day for a lifetime.
22
-------
Toxlci ty Assessment
Under current EPA guidelines, the likelihood of carcinogenic and
non-carcinogenic effects due to exposure to site chemicals are considered
separately. Criteria for evaluating the potential of site chemicals to cause
these two types of adverse effects are described below.
A. Criteria for Non-Carcinogenic Effects
The acceptable dally Intake for chronic exposure (ADI) Is an estimate of
the highest human Intake of a chemical, expressed as mg/kg/day, that does not
cause adverse effects when exposure is long-term (lifetime). ADI values are
based on animal or human toxlcity studies from which a no-observed-adverse-
effect level (NOAEL) is experimentally determined. The NOAEL is the highest
dose at which there was no statistically or biologically significant adverse
effect observed. The ADI Is derived by dividing the NOAEL from the selected
study by an uncertainty factor. The uncertainty factor consists of multiples
of 10 to account for specific areas of uncertainty in the available data. For
example a total uncertainty factor of 1,000 may be used to account for; use of
a subchronic (short-term) study (10), for extrapolation from animals to humans
(10), and for protection of sensitive human populations (10).
When the EPA completes verification of the chronic toxlcity of a specific
chemical, it establishes a "reference dose" or RfD. If the RfD for a chemical
has been established, then the RfD is used as the ADI for evaluating long-term
non-carcinogenic risks at the site.
The dose calculated from the exposure assessment 1s compared to the RfD
to determine whether adverse effects might occur. If predicted exposure
concentrations are below the level of the RfD, no adverse health effects are
expected according to current EPA guidelines.
The oral RfDs for PERC and TCA are 0.01 and 0.09 mg/kg/day, respectively,
each calculated with an-uncertainty factor of 1,000 (USEPA, 1988). The RfD
for PERC 1s based on observations of liver toxicity In mice. Including
increased liver weight/body weight ratios, changes in liver enzyme levels, and
necrosis (death of liver tissue). Increases in liver and kidney weight/body
weight ratios have been observed in rats, also. The RfD for TCA is based on
fatty changes in the liver and Increased liver weights in guinea pigs exposed
via inhalation. Non-carcinogenic health effects of TCE are similar to those
of PERC and TCA; however, an oral RfD for TCE is not currently available and
therefore not evaluated .here.
RfDs for dermal absorption have not yet been determined by the EPA.
However, for volatile organic compounds, such as the chemicals of concern at
the Northslde Landfill, current EPA policy is to use the oral RfD In
calculating the hazard index for dermal exposure. The hazard index is the
ratio between route-specific calculated dose and the RfD. Ratios exceeding
unity (one) indicate doses that exceed the acceptable levels; ratios less than
one are not expected to cause adverse health effects. One of the assumptions
in using an oral RfD is that 100% of the chemical was absorbed via the route
investigated In the study that was used to derive the oral RfD. This is a
reasonable assumption for a dermal RfD for the chemicals of concern at this
site.
23
-------
As noted previously, risks from inhalation exposure were not calculated
directly, but assumed to be equal to (average case) or two times (upper-bound
case) the risks from ingestion of 2 liters of water per day, according to EPA
guidelines (USEPA, 1989a).
B. Criteria for Carcinogenic Effects
The EPA uses a welght-of-evidence system to convey how likely a chemical
is to be a human carcinogen, based on epldemiological studies, animal studies,
and other supportive data. The classification system of the EPA for
characterization of the overall weight of evidence for carclnogenlcity
includes: Group A- Human Carcinogen; Group B- Probable Human Carcinogen;
Group C- Possible Human Carcinogen; Group D- Not Classifiable as to Human
Careino'genicity; and Group E- Evidence of Non-Cardnogenicity for Humans.
Group B Is subdivided into two groups: Group Bl- limited human evidence for
carcinogenicity; and Group 82- sufficient data in animals, but inadequate or
no evidence in humans.
TCA Is currently in Group D, not classifiable as to human
carcinogenidty, and therefore was not evaluated for carcinogenic risks. PERC
and TCE are currently classified as probable human carcinogens by the EPA,
.Group 82. However, the status of these compounds and their respective cancer
potency factors Is now under review.
For PERC, the review concerns whether this chemical Is most appropriately
classified 1n Group 82 or C. Evidence of liver tumors (in both sexes of mice
by two routes of administration), leukemia in rats, and renal carcinomas in
male rats, along with supportive metabolic considerations, provide a basis for
classifying PERC In Group 82. However, mutagenicity data have In general been
negative or Inconclusive. Furthermore, the relevance of mouse liver tumors to
human cancer risk 1s still in question. PERC would therefore be classified as
Group C, possible human carcinogen, if one accepts the weighting of the animal
evidence to be limited.
For chemicals with carcinogenic effects, EPA calculates the cancer risk
associated with a given dose by multiplying the dose from a given route of
exposure by a cancer potency factor or potency slope. The EPA derives potency
factors from the upper 95^ confidence limit of the slope of the extrapolated
dose-response curve, which shows the relationship between a given dose and the
associated tumor incidence. As a result, the predicted cancer risk is an
upper-bound estimate of the potential risk associated with exposure.
•
The present oral cancer potency factors for PERC and TCE are 5.1 x 10~2
and 1.1 x 10-2, respectively (USEPA, 1988). There are no cancer potency
factors for dermal absorption. However, for volatile organic compounds, such
as the chemicals of concern, current EPA policy Is to use the oral potency
slope in calculating cancer risk from dermal exposure.
Risk Characterization
A. Carcinogenic Risks
Estimates of carcinogenic risks for the three exposure scenarios
considered are presented in Tables 2, 3, and 4. These risks are the estimated
lifetime incremental upper-bound risks of developing cancer as a result of
24
-------
being exposed to PERC and TCE under the assumed conditions. The risks
associated with exposure to each chemical via oral, inhalation, and dermal
exposures routes are given. Also, total excess risk values are shown for
each scenario. Total excess risk values are calculated by adding the risks
due to exposure to both chemicals by all three exposure routes.
Table 2 shows the estimated cancer risks based on an average exposure
to PERC and TCE due to use of an offsite well. The total excess risk is 9
x 10~6 for this scenario. This number represents an increased risk of
contracting cancer of nine chances In one million for a person exposed for
70 years.
Estimated cancer risks based on exposure to PERC and TCE due to use of
the most contaminated offsite wells (the Pel low and Volkman Wells) Is shown
in Table 3. For each of these wells, exposure to the average and maximum
concentrations of each chemical observed at the well was considered
(average and upper-bound cases, respectively). For the Pel low Well, total
excess risks are estimated to be 8 x 10~5 and 2 x 10~4 assuming
exposure to average and maximum concentrations, respectively. For the
Volkman Well, total excess risks are estimated to be 2 x 10~6 and 9 x
10~6 assuming exposure to average and maximum concentrations,
respectively.
Table 4 shows the estimated cancer risks based on exposure to PERC and.
TCE due to use of the most contaminated onsite wells (the MW-M and MW-T
Wells). For Well MW-M, the same two levels of exposure were considered as
for the offslte wells. Total excess risks are estimated to be 5 x 10~5
and 1 x 10~* assuming exposure to average and maximum concentrations,
respectively. For the MW-T Well, the total excess risk is 1 x 10~4 for
both the average and upper-bound exposure calculations, based on the single
available observation.
B. Non-Carcinogenic Risks
Non-carcinogenic risks are presented as a hazard index which is the
ratio between the route-specific calculated dose and the RfO. Ratios
exceeding unity (one) indicate doses that exceed the acceptable level;
ratios less than one are not expected to cause adverse health effects.
Based on the highest observed concentrations of PERC and TCA, the
Pellow and MW-T Wells were the offsite and onsite wells, respectively,
found to pose the greatest risk of non-carcinogenic effects. The estimated
doses of each chemical, based on the maximum observed concentration, and
the corresponding hazard index are presented below for the Pellow and MW-T
Wells.
Pellow Well PERC TCA
(mg/kg/day) (mg/kg/day)
Oral Dose 1.1 x 10~3 2.9 x 10~4
Inhalation Dose 2.2 x 10~3 5.7 x 10~4
Dermal Dose 4.1 x 10'6 1.1 x ICr6
Total Dose (A) 3.3 x 10~3 8.6 x ICr4
RfD (B) 1.0 x ID'2 9.0 x 10~2
Hazard Index (A/B) 0.30 0.01
25
-------
MW-T Wei1 . PERC TCA
(mg/kg/day) (mg/kg/day)
Oral Dose 9.4 x 10~4 5.1 x I0~4
Inhalation Dose 1.9 x 10~3 1.0 x 10~3
Dermal Dose 3.6 x 10~6 1.9 x 10-6
Total Dose (A) 2.8 x 10~3 1.5 x 10-3
RfD , based on the highest observed
concentration (6 ug/1) and an oral cancer potency slope of 0.0061
(USEPA, 1988). Because these chemicals are degradation products of the
other chlorinated organrcs, vinyl chloride and chloroform levels could rise
and pose risks greater than the above estimates.
D. Conclusions
In conclusion, the total incremental increase in cancer risk for the
average exposure scenario is 9 x 10~6. For exposure to one of the
offslte wells with the highest average concentration of carcinogens, cancer
risks range from 2 x 10~6 to 1 x 10~4. Estimated cancer risks from
exposure to groundwater from the most contaminated onsite wells range from
5 x 10~5 to 1 x 10~4. These scenarios are based on the assumption that
the population at risk is using groundwater near the Northside Landfill as
the only source of drinking water over an entire lifetime (70 years).
Non-carcinogenic health effects are not expected from exposure to PERC and
TCA at the present level of contamination in onsite and offsite wells.
26
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DESCRIPTION OF ALTERNATIVES
The goal of the remedial actions is to prevent, reduce, or control the
contaminants leaving the landfill and entering the groundwater. •
Technically applicable technologies were identified in the FS for each of
the units. Most of the remedial actions that passed the screening process
for one of the landfill solid waste units (refuse, skimmings, old burn, or
sewage sludge) passed for all of the other three. The aquifer unit
includes different technologies that deal with the migration of the
contaminants In groundwater and not the material In the refuse. The
description of the treatment alternatives is divided Into those for the
landfill units and those for the aquifer unit.
Landfil'l Units
Remediation of the landfill units must control, as far as possible,
the leaching of contaminants into the groundwater. This may be done by
either:
a) capping the landfill to eliminate leaching;
b) diverting stormwater so that it does not generate leachate; or
c) excavating the landfill and removing the contaminated waste.
If it proves impracticable to control leachate, administrative restrictions
may be enacted to reduce exposure to contaminants. Another alternative
considered Is to take no action.
a) Capping. The cap system would consist of multiple layers, including
topsoil, soil cover, drainage layers, and bedding/protection layers,
in conjunction with a low permeability, barrier layer to control
infiltration. Around the perimeter of the cap, collection ditches
would be Installed to intercept stormwater runoff and convey it to
appropriate points of discharge. Three different types of cap systems
were considered: synthetic membrane, synthetic membrane and clay, and
sol1/bentonite.
The cap would utilize proven technologies. Its main advantage is that
it restricts the amount of leachate that can enter the aquifer unit by
reducing the infiltration of precipitation into the landfill.
Precipitation is the principal source of leachate generation for the
landfill because It. is located above the Identified groundwater
tables. Therefore, if precipitation, run-on, and any lateral flows
from the hillside can be kept from entering the waste, the health and
environmental hazards associated with leachate generation and
contamination of the aquifer unit would be significantly reduced.
Disadvantages of capping include the waste of concern remaining
onsite, the potential for the cap to leak and generate additional
leachate, and the magnitude of grading and covering 345 acres of
land. Leakage of the cap is a concern because of the potential for
future leachate generation. The design and Installation of the cap
would need to be carefully done, and a maintenance program would be
necessary to reduce the risk of leaks developing in the system over
27
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time. Environmental impacts of the cap installation are considered
temporary because the existing surface topography would not change
significantly and vegetation would be reestablished.
Capping, of course, presupposes the closure of the landfill. Three of
the units—old burn, sewage sludge, and skimmings—are no longer in use
and could be capped at any time, but the refuse unit currently is
scheduled to remain In use until December 31, 1991, when the
waste-to-energy treatment system becomes operational. Any refuse taken
to the Northside site after December 31, 1991, will be required to be
placed into a new disposal unit which meets the state's Minimum
Functional Standards (MFS) requirements.
ARARs
The closure and capping alternative include action-specific applicable or
relevant and appropriate requirements (ARARs). The primary ARAR is the
Washington State Minimum Functional Standards for Performance (MFS) (WAC
173-304-460). The MFS are applicable to landfills that Institute closure
after November 27, 1989. The Northside Landfill will be operating beyond
1989.
The MFS Include requirements for the final cover, groundwater monitoring,
landfill gas monitoring and control, runoff and leachate control, a
closure plan, and a closure cost estimate.
The wastes in the landfill are not currently classified as hazardous
wastes under RCRA because the only sources identified are small quantity
generators. Since closure and capping do not include the placement of
RCRA hazardous wastes, those RCRA regulations would not apply.
There are no chemical-specific or location-specific ARARs identified for
this alternative.
b) Surface Hater Diversion and Collection Systems. These systems are
designed to divert and collect stormwater runoff and keep it from
infiltrating the landfilled wastes, thereby reducing the potential for
leachate generation. The diversion and collection systems would consist
of ditches, culverts, and pipelines that collect runoff from flow
concentration areas and convey it to an appropriate point of discharge.
The ditches would be lined to ensure that infiltration would be minimized.
»
This alternative's chief advantages are that it would consistently help
reduce leachate-generating precipitation from entering the landfill, and
it is low in cost. The disadvantage is that it does not address
infiltration by precipitation that falls within the landfill boundaries.
In the final analysis of alternatives, surface water diversion is not
considered a separate alternative, but rather a component of capping, and
is included as part of that alternative.
c) Excavation and Offsite Disposal. One additional remedy passed screening
for the Skimmings Unit only. It was rejected for the refuse unit because
of high cost and EPA preference for onsite. remedies (the old burn and -
sewage sludge units have low contaminant levels and disproportionately
28
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higher costs).. .This alternative entails total removal of grease
skimmings (though, not any contaminated soil) which would then be disposed
of offsite at a permitted hazardous waste landfill. As this is an
offsite activity, such disposal must comply with all applicable hazardous
and solid waste disposal requirements. These include RCRA and the state
Dangerous Waste and solid waste regulations.
d) Excavation and Onstte Treatment. Treatment onsite is either through land
treatment or incineration. Land treatment is described as biological
treatment of the waste done onsite but not in-situ. This meets EPA's
preference for onsite treatment.
The chief advantages of this alternative are its permanent elimination of
one potential contaminant source, its elimination of the health hazard
for this area of the site, and the fact that it restores the area for
possible future use. No administrative restrictions would be necessary
after excavation and treatment were completed.
Disadvantages of this alternative include health and safety impacts
associated with excavation, environmental concerns (e.g., worker exposure
to contaminants during excavation and treatment), demonstrated
effectiveness, and cost.
ARARs
Several action-specific ARARs are identified for excavation and treatment
alternatives evaluated for the Skimmings Unit area within the landfill.
The skimmings originated from the city's wastewater treatment plant and
are not RCRA hazardous wastes or state dangerous wastes either by
definition or by characteristic.
Any contaminated soils not excavated can be treated as a non-disturbed
solid waste unit (not hazardous) and capped according to applicable
regulations.
Excavation of the skimmings could also be expected to result in the
release of some quantity of volatile organics. There are currently no
standards for PERC emissions, so any requirements would be determined by
risk assessments which are not ARARs, but are "to be considered" in
design of the remedial action.
9
Excavation and onsite treatment of the skimmings includes two treatment
options. Both options Include the excavation of the grease skimmings
followed by treatment and placement back onsite. Land treatment of the
skimmings has no applicable regulations. However, the disposal of any
hazardous wastes generated as a result of the treatment process would be
required to meet the RCRA disposal requirements, which would be
applicable to this new waste's disposal.
The Incineration of the skimmings has relevant and appropriate RCRA
requirements for the operation and disposal of the waste streams.
Although the incoming waste is not RCRA regulated, the RCRA ash and air
emissions requirements for Incineration would be relevant and appropriate
because of the PERC concentrations in the waste.
29
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There were no chemical-specific or location-specific ARARs identified for
the excavation alternatives.
For the excavation with off site disposal alternative., the RCRA hazardous
waste regulations are not applicable because the skimmings are not a RCRA
waste. However, offsite activities, such as disposal, will be regulated
by applicable laws and regulations, and are not subject to ARAR
analysis. For example, the transportation and packaging of the skimmings
as a hazardous solid waste because of the PERC content Is regulated by
the U.S. Department of Transportation.
d) Administrative Restrictions. This would involve restricting land use
with respect to future onslte excavation and construction.
The chief advantages of this alternative are its low cost and ease of
implementation. Public health would be protected by reducing exposure to
the contaminants at the site.
The primary disadvantage is that administrative restrictions would not be
effective in eliminating or reducing public health concerns offsite.
Infiltration would not be reduced nor surface water or groundwater flow
controlled; thus the leachate would continue to be produced. The MFS,
which 1s an ARAR and requires landfill capping, would not be met.
e) No Action. The landfill would be left in its current condition without
any remedial action being taken. There would be no cost, but public
health would not be protected. ARARs would not be met.
Aquifer Unit
For this unit, the remedial objective 1s to reduce health risks from the
contaminants In the groundwater. Alternatives include:
a) extracting and treating the contaminated water;
b) monitoring;
c) administrative restrictions;
d) providing an alternate water supply; and
e) no action.
a) Collection Hells. Treatment, and Discharge. The purpose of the
extraction and treatment system is to reduce and control the release of
contaminants into tfie aquifer downgradient from the landfill. The
aquifer unit alternative includes six variations using two extraction
options for the contaminated groundwater and three treatment levels for
each extraction design.
The two extraction (pump) options are extracting the entire contaminated
plume (total plume capture) and extracting only a portion of the
contaminated plume (partial plume capture). The total plume capture.
system uses extraction wells across the entire width of the contaminated
plume and would be designed to extract groundwater with any amount of
contamination for treatment. This would include pumping large volumes of
groundwater that is currently contaminated at levels below the protective
requirements. The partial capture system would extract only that
groundwater that is contaminated at concentrations greater than existing
30
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standards. This would reduce the amount of water that would need to be •
pumped and subsequently the volume that would be treated.
The difference between the two capture options, besides the amount of
water pumped, is the amount of control over the release of contaminants
downgradient from the system. This would have an impact on the time
needed for recovery of the contaminated plume downgradient. Both options
would control releases downgradient of the extraction system so that they
would meet drinking water ARARs and protectiveness requirements in the
aquifer. The design of the extraction system will determine where the
actual extraction wells will be located.
The. extracted contaminated groundwater would then be treated or
discharged into the city's wastewater treatment plant for treatment and
then discharged into the Spokane River. Three levels of treatment have
been Identified in the FS, which are: no treatment, treatment to
drinking water levels and Ambient Water Quality Criteria (AWQC) levels,
or treatment to background levels.
All of the pump and treat alternatives would also require groundwater
monitoring, administrative restrictions, and an alternative drinking
water supply. There would be minimal environmental Impact during well
construction and few anticipated health or safety concerns for the
surrounding community.
ARARs.
The ARARS are essentially the same for the two extraction alternatives.
The major regulations that contribute to the list of potential
chemical-specific ARARs are the Clean Water Act (CWA), the Safe Drinking
Water Act (SDWA), and the Water Quality Standards for the State of
Washington (WAC-173-201) (90.48 RCW). The acts are under the
jurisdiction of and are enforced by the Washington State Department of
Health Services, the Washington State Department of Ecology (Ecology),
and EPA.
The SDWA Maximum Contaminant Level (MCL) standards are enforceable
standards that are applicable to surface water or groundwater that can be
classified as a source or potential source of drinking water. The MCLs
are applicable to any action that affects the concentration of
contaminants in groundwater which is a source of drinking water, such as
the SVRPA.
The discharge of extracted water to the Spokane River is considered to be
offsite and is therefore not subject to ARARS analysis. Compliance with
the applicable laws, regulations, and permit requirements is necessary.
Some discussion of the discharge requirements is Included since treatment
may be done onsite.
The CWA Ambient Water Quality Criteria (AWQC) are designed to protect
aquatic life and human health. The state of Washington adopts the AWQC
by reference Into their water quality standards, so the AWQC are
requirements for surface water discharges. Table 5 presents
chemical-specific potential ARARs for water. The table is arranged by
chemical compound.
31
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TABLE 5
CHEMICAL-SPECIFIC ARARS AND TBCS FOR ORGANIC CONTAMINANTS
FOUND AT THE NORTH LANDFILL
Clean Water Act
N>
Safe Drinking
Water Act
Compound
Chloroform
1 , 1-Dichloroe thane
1 , 2- (Trans) Dich loroethy lene
Tetrach loroethy lene
1,1, 1-Trichloroe thane
Tr ich loroethy lene
Vinyl Chloride
MCL
iooa
-
-
-
200
5
2
MCLG
-
-
-
oe
-
-
0
Consumption of
Acute Chronic
Toxicity Toxicity
28,900b l,240b
- '
ll,600b
5,280b 450b
-
45,000b
-
Pish and
Water
0.19
0.94°
0.33d
0.8
18,400
2.7
2.0
Fish
Only
15.7
243C
1.85d
8.85
1,030,000
80.7
525
Reference-
Dose Da.scd
Criteria
350
4,500
350
10
1,000
260
46f (J3f)
All units in pg/1.
Criterion for total trihalomethanes (sum of chloroform, bromodichloromethane, dibromochloromethane,
and bromoform).
Lowest observed effect level.
CCriterion for chlorinated ethanes based on toxicity of 1,2-dichloroethane.
Criterion for dichloroethylenes based on carcinogenicity of 1,1-dichloroethylene.
GProposed October 1986.
Longer term Health Advisory for adult and 10 kg child is the 46 and 13 pg/1, respectively. Lifetime
Health Advisory not calculated.
-------
Minimum treatment of the' extracted groundwater with ultimate discharge to
the Spokane River must comply with Ambient Water Quality Criteria
(AWQCXsee Table 5). The quality of the untreated groundwater would not
be expected to satisfy the AWQC for fresh water due to VOC
concentrations. An NPDES permit would have to be obtained from Ecology
prior to initiating the discharge. Discharges to the river will be
required to comply with the phosphorus discharge limits established for
the Spokane River. The alternative would also have to be analyzed for
its effect on fish, wildlife, and habitat in and around the Spokane River
as required by the Fish and Wildlife Coordination Act. No other
location-specific natural resource ARARs were identified.
The extracted groundwater wi11 be treated to meet drinking water
standards for metals and volatile organic compounds or meet NPOES and
AWQC requirements, whichever is more stringent, prior to discharge to the
Spokane River. There would be some level of contamination remaining in
the treated water discharged to the Spokane River.
The cost for the extraction and treatment alternatives would be moderate
to high, depending on the number of wells and the specific treatment
process selected.
b> Monitoring. The existing groundwater monitoring system would continue to
be used until the long-term monitoring plan is developed and approved by
EPA. This existing system consists of wells both on- and offsite which
were Installed at various depths to indicate the level of contamination.
Monitoring would be low In cost and easily implemented, since it could '
largely utilize an existing system which could be supplemented if the
existing wells are determined to be inadequate. It would provide a means
for measuring the effectiveness of other response actions. However, it
would not In Itself protect public health.
Groundwater monitoring for the purpose of early detection of contaminants
beyond the existing plume area does not satisfy ARARs because the
existing groundwater contaminant levels would continue to exceed drinking
water MCLs within the plume.
c) Administrative Restrictions. Under this alternative, the city would
prevent the installation of well: in the contaminated portion of the
aquifer. Though all affected residences are now connected to the city
water system, there" are currently no regulations to make future
residences connect with this system or prevent existing contaminated
wells from being used.
This alternative would protect public health by limiting exposure to
contaminated groundwater; it would be low in cost to Implement. It would
not reduce contamination, and ensuring compliance could be difficult.
Administrative restrictions to prevent use of the contaminated
groundwater in the area of the plume do not satisfy ARARs because
groundwater contaminant levels would continue to exceed drinking water
MCLs for decades.
33
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d) Alternative Hater Supply. All new residences in the area of
contamination would be connected with the municipal water system, as
existing residences .already are. It would be technically feasible since
there are nearby water lines, though some new service laterals might have
to be constructed. Public health would be protected and cost would be
low, but the groundwater would remain contaminated. There were no
environmental receptors of the contaminated groundwater identified in the
FS.
An alternate source of drinking water for residents located In the local
area of the contaminated plume does not satisfy ARARs. Groundwater
contaminant levels would continue to exceed drinking water MCLs until
natural recovery reduces the contaminants below the MCLs. This
alternative would help in the Interim to protect public health, but
contamination would not be reduced to MCLs; therefore, It would not
satisfy ARARs.
e) No Action. No remedial measures would be implemented, beyond those
already in place (I.e., providing alternative water to existing
residences). There would be no cost, no change in the level of
protection of public health, and no reduction of contamination in the
aquifer. Water quality and Safe Drinking Water Act ARARs would not be
met.
34
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COMPARATIVE ANALYSIS OF ALTERNATIVES
CERCLA guidance (U.S. EPA 1988) requires that each remedial alternative
be evaluated according to specific criteria. The purpose of the evaluation is
to identify the advantages and disadvantages of each alternative, and thereby
guide selection of the remedy offering the most effective and feasible means
of achieving the stated cleanup objective. Hhlle the nine CERCLA evaluation
criteria are all Important, they are weighted differently In the
decisionmaklng process depending on whether they describe a required level of
performance (threshold criteria), technical advantages and disadvantages
(primary balancing criteria), or overall evaluation by non-EPA reviewers that
may affect an EPA decision (modifying criteria).
EPA evaluated the four landfill units together because, they all had
similar technologies that passed the screening step. The evaluation of the
aquifer unit follows because it has different possible technologies than the
landfill units. The nine evaluation criteria are:
Threshold criteria
1. Overall protection of human health and the environment
2. Compliance with ARARs
Primary balancing criteria
3. Long-term effectiveness and permanence
4. Reduction of toxicity, mobility, or volume
5. Short-term effectiveness
6. Implementabi1ity
7. Cost
Modifying criteria
8. State acceptance
9. Community acceptance
Table 6 provides a summary of the alternative evaluation criteria.
Threshold Criteria
The remedial alternatives were first evaluated in relation to the
threshold criteria: overall protection of human health and the environment
and compliance with ARARs. The threshold criteria must be met by the
candidate alternatives for "further consideration as remedies for the ROD.
1. Overall Protection of Human Health and the Environment
This criteria addresses whether or not remedial action provides adequate
protection or describes the mechanisms for controlling risk for the different
exposure pathways.
35
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TABLE 6
SUMMARY OF ALTERNATIVE EVALUATION CRITERIA
Remedial
Alternative
Protection
of Health
and Environment
Compliance
with ARARs
Long Term
Effectiveness
and Permanence
Short Term
Effectiveness
Imolementabili tv
LANDFILL UNITS
Capping
0 Moderate to
highly effective
reduction of long-
term health risks.
0 Not effective
for short term
reduction of
contamination
entering the aquifer.
Applicable
state and federal
ARARs; can be
designed to meet
Requirements.
30+ yrs. useful life;
Reduces effect of
source on aquifer;
Requires O&M
Contains the
source & reduces
some exposure
routes.
Proven technology;
1 yr. to construct;
substantial grading
of steep slopes.
Excavation
Off Site
Disposal
Highly effective,
removes a source
of contamination;
possible short term
risks to workers.
ARARs apply to
all 3 options.
ARARs can be mat
by proper design.
Effective source
removal; residual in
soils will leach
Effective source
removal; residuals
remain in soil.
Proven technology;
takes 4-6 mos. to
excavate and
transport.
On-site
Treatment
Highly effective,
long term &
permanent but slow
to implement;
possible short term
risk to workers.
Effectiveness
unknown; residuals
may exist which
can leach.
Effectiveness
unknown; requires
treatability
studies.
Innovative
technology;
requires
treatability
studies & may
take 10 yrs.
to implement.
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TABLE 6 (cont'd)
SUMMARY OF ALTERNATIVE EVALUATION CRITERIA
Page 2
Remedial
Alternative
Protection
of Health
and Environment
Compliance
with ARARs
Long Term
Effectiveness
and Permanence
Short Term
Effectiveness
Imolementabilitv
On-Site
Incineration
Administrative
Restrictions
No Action
Highly effective
& permanent treat-
ment; Possible short
term risk from air
emissions.
Low protection for
exposure; no
protection to
groundwater.
No reduction in
risk.
Any new requirements
must be constant
with other laws
and regulations.
Currently does
not meet ARARs.
Effective removal;
residuals will
remain to leach.
Permanent remedy.
None
Effective removal;
residuals in soil
remain.
Effective
reduction to human
risk.
None
Innovative
technology;
nay require
demonstration;
1 yr. to
implement.
No 1 imitations.
None
AQUIFER UNIT
Pumping &
Treatment
Highly effective
in permanently
reducing health &
environmental risks.
Applicable state
& federal ARARs.
Treatment can be
designed to meet
discharge ARAK
criteria.
Highly effective in
controlling off-site
migration. Useful life
20+ yrs. Requires
O&M.
Highly effective
in controlling
downgradient migration
Proven technology;
2 yrs. to design
and construct.'
-------
TABLE 6 (cont'd)
SUMMARY OF ALTERNATIVE EVALUATION CRITERIA
Page 3
Remedial
Alternative
Protection
of Health
and Environment
Compliance
with ARARs
Long Term
Effectiveness
and Permanence
Short Term
Effectiveness
Imolementabil itv
Administrative
• Restrictions
Groundwater
Monitoring
Alternative
Water Supply
No Action
Moderately effective
preventing future
from construction
of new wells. •
No protection.
Highly effective
for short term
and possible long
term; Reduces use
of contaminated
aquifer.
No protection.
Any new
requirements must
be consistent with
existing ones.
Meets ARARs.
Permanent remedy.
Municipal water
system currently
meets ARARs.
Currently does
not meet ARARs.
Can be maintained
for long term;
Requires sampling
and analysis.
Useful life is 50*
yrs. Highly
effective system.
Not effective;
no reduction
in risk.
Reduces exposure
to contaminated
aquifer.
Only measures
contamination;
no protection.
Highly effective
at reducing
health risks.
No limitations.
No additional
protection to use
of groundwater.
Proven technology;
system in place.
Proven technology;
system in place.
None
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Landfill Units
The most effective alternative for the landfill would be capping
(incorporating a surface water collection system, as discussed
previously). All of the landfill units include a capping alternative.
These alternatives would take take about a year to implement and the
effectiveness would show decreases in concentrations of compounds in the
aquifer 5 to 10 years after completion. Capping Is a containment
technology because It controls the mobility of the contaminants through
the waste material.
Under this remedy the wastes would remain onslte, but the potential for
future leaching of contaminants Into the groundwater would be reduced.
Since leachate is considered the main source of groundwater contaminants,
the prevention or reduction of leachate should result in gradual recovery
of the groundwater. Since groundwater is the main exposure pathway for
the site's contaminants, any alternative reducing groundwater
contamination would substantially reduce the risk to public health.
Although effects on non-human biota have not been studied at this site,
presumably they too would be less at risk. The actual construction of
the cap would have some environmental impact, but it would be minimized
and temporary.
The most protective alternative evaluated for the Skimmings Unit, a small
section of the landfill, would be excavation and treatment.
Implementation would result in all contaminated wastes being either
removed or rendered substantially less hazardous, thus reducing the
threat to public health. However, this alternative would have more
adverse effects on the environment during construction (e.g., noise,
possible air exposure to contaminants) than any of the other alternatives.
Excavation and onslte land treatment or onsite Incineration both are very
protective since there is a reduction In the amount of contaminants after
the cleanup goals are met. During the treatment processes and during
excavation there would be slight, unquantlfiable increases in short-term
risk because of discharges of VOCs to the air during excavation,
incineration and land treatment.
Administrative restrictions such as not allowing drinking water wells in
the contaminated plume would limit exposure to contaminants, but would
not reduce actual contamination, and so this alternative receives a low
rating In terms of public health and environmental protection.
The no action alternative reduces neither the level of contamination nor
public exposure to contaminants, and thus does not protect public
health. The current environmental impact would continue.
Aquifer Unit
The total plume capture alternative described In the FS would pump and
treat the entire contaminated plume at the boundary of the landfill, thus
reducing the risk from any groundwater use downgradient. The partial
plume capture alternative as described in the FS would pump and treat the
contamination that is above MCLs at the landfill boundary and reduce the
-------
concentration of contaminants of concern to below drinking water
standards. Under, both capture options the groundwater leaving the
landfill would meet the MCLs for the aquifer. This would reduce the
risks downgradient from the landfill and eventually allow full use of the
aquifer again. The treatment facilities described in the FS.for both of
these alternatives would produce air emissions from the volatile organic
compounds removed from the groundwater. The exposure to these air
emissions would be below health based criteria because concentrations are
expected to be below detection limits at exposure points. Discharge of
treated groundwater to the Spokane River would increase the amount of
measurable compounds reaching the river. Treatment will reduce the
discharge concentrations to meet health based and receiving water quality
standards.
Administrative restrictions would restrict future well drilling and
existing well usage In the area of the contamination plume and thus
reduce the potential for consumption of contaminated water. This would
provide limited human health protection, and no protection to the
environment.
An alternative water supply would also limit (but not eliminate) human
exposure to contaminated groundwater, and would not protect the
environment.
Groundwater monitoring would not in itself protect public health or the
environment, though It would provide evidence of future.changes in health
risk from the groundwater.
• *
The no action alternative would involve no technical or administrative
remedial action. There would be no protection of human health or the
environment.
2. Compliance with ARARs
The purpose of this analysis Is to identify applicable or relevant and
appropriate requirements (ARARs) that may be major components of the remedial
actions and to evaluate the alternatives for compliance with the ARARs and
those criteria to be considered (TBCs) in the evaluation, such as certain
health based risk assessments to help determine what is protective.
Landfill Units
9
Excavation of the skimmings from the Skimmings Unit could be expected to
result In the release of some quantity of volatile organics. Although
the concentration would be expected to be low, risk assessments for VOCs
should be consulted. The offsite disposal portion of this alternative is
not subject to ARARs evaluation.
The excavation and onsite land treatment alternative shares the above
requirements relating to the excavation of the wastes. However, no -ARARs
have been identified for this alternative because the skimmings are not
considered a hazardous or dangerous waste and no hazardous waste
by-products are expected. Land treatment has some "to be considered"
state guidance for the skimmings wastes which will require that
monitoring be incorporated to ensure the protection of underlying
40
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groundwater. .State laws require control or collection of surface .water .
runoff will be needed to prevent offsite migration of contaminants. The
release of volatile organic compounds will be enhanced by land
treatment. This emission source will need to be evaluated as "to be
considered" with respect to air pollution source criteria or risk
analyses.
Incineration of the skimmings includes some special ARARs for the
Skimmings Unit. The RCRA requirements would be relevant and appropriate
for incineration, due to the concentration of PERC in the waste. The
requirements relating to the excavation of the wastes and the containment
of site run-off are similar to offsite disposal and onsite treatment.
The onsite incinerator would be required to comply with RCRA hazardous
waste incineration requirements for hazardous or dangerous waste. These
include emissions monitoring and control, wastewater treatment, and
disposal of ash and solids from the emission control and wastewater
treatment processes.
Capping the landfill has the same ARAR analysis for all landfill units.
The wastes in the landfill have not been classified as hazardous or
dangerous wastes; therefore, the primary ARAR will be the Washington
State Minimum Functional Standards for Performance (MFSMWAC
173-304-460). The MFS will be applicable to existing facilities that
institute closure after November 27, 1989. The projected operating life
of the Northside Landfill is beyond 1989. The MFS Include requirements
for the final cover, groundwater monitoring, landfill gas monitoring and
control, surface water, runoff and leachate control, a closure plan, and
closure cost estimate. RCRA is a relevant and appropriate requirement
for post-closure monitoring.
The requirement for a cap with 2 feet of 1 x 10~6 cm/sec or lower
hydraulic conductivity material or equivalent will be met by all three
types of cap. The requirements also include control of upgradlent
surface water runoff entering the site, diversion of offsite surface
water, collection of surface water onsite, and minimum slope criteria.
These alternatives, in conjunction with a gas collection and control
program (being prepared by the City of Spokane), and a closure plan and
cost estimate, satisfy the MFS requirements.
Administrative restrictions placed on the site would not satisfy the MFS
requirements for landfill closure which requires other specific actions.
The No Action alternative does not satisfy the MFS requirements for
landfills.
The offsite disposal of any wastes will have to meet all substantive and
procedural requirements of federal, state, and local regulations. In
addition to disposal requirements, this alternative would also have to
satisfy transportation and handling requirements.
Aquifer Unit
Solvents collected from the treatment of the extracted groundwater in any
tanks, surface impoundments, or treatment residue would have to meet
applicable hazardous or dangerous waste requirements (WAC 173-303) for
disposal based on the VOC content.
41
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The groundwater monitoring alternative for the purpose of early detection
of contaminant migration in the groundwater does not satisfy ARARs
because groundwater contaminant levels would continue to exceed drinking
water MCLs for an extended period of time. The same is true for the
administrative restrictions, alternate water supply, and no action
alternatives.
The groundwater extraction and treatment system for both total plume
capture and partial plume capture have to meet similar laws and
regulations. The discharge of the treated groundwater has to meet the
requirements of the AWQC or MCLs. As the discharge 1s offsite, NPOES
permit requirements for the point source discharge would have to be met
before discharging to the Spokane River. The discharge would also have
to be analyzed for its effects on fish, wildlife, and habitat in and
around the river as required by the Fish and Wildlife Coordination Act.
Primary Balancing Criteria
Once an alternative satisfies the threshold criteria, five primary
balancing criteria are used to evaluate other aspects of the potential
remedies. Each alternative is evaluated by each of the balancing criteria.
One alternative will not necessarily receive the highest evaluation for every
balancing criterion. The balancing criteria evaluation will be used in
refining the selection of candidate alternatives for the site. The five
primary balancing criteria are: long-term effectiveness and permanence;
reduction of toxicity, mobility, or volume through treatment; short-term
effectiveness; implementabi1ity; and cost.
3. Long-Term Effectiveness and Permanence
This Is the ability of a remedial alternative to provide protection and
reduce risks to health or the environment long after the cleanup goals have
been met.
Landfill Units
The excavation and disposal alternative is only feasible for the
Skimmings Unit, a small area within the landfill. Removal to an offsite
treatment and disposal facility is the most effective long-term remedy
because It removes all of the contamination from the unit, although it
does transfer the risks from this material to the disposal facility.
Excavation and onsVte treatment is nearly as permanent because it can
reduce toxicity of the waste. Both of these alternatives remove the
contamination from the site or treat it to reduce the toxicity. Once the
soils are treated to'the cleanup goals there would be no need for
long-term maintenance.
Capping the landfill units Is the next most effective and permanent
remedial alternative. Three variations of cap design were evaluated and
all three designs meet the minimum requirements for a landfill cap.
Stormwater collection and diversion systems and runoff controls are
included in the cap design; all providing a physical barrier that will
reduce Infiltration to the refuse.
42
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The projected life span of.the cap is 30 years or more. Maintenance is
required to maintain the integrity of the cap and srormwater diversion
systems.
Although capping is containment and not treatment, it reduces
infiltration through the refuse thereby reducing the amount of leachate
produced. This reduces the amount of contaminants entering the
groundwater aquifer.
Implementation of administrative restrictions could not be considered
permanent because It can only restrict human access to contaminated
groundwater and cannot prohibit it entirely. Their long-term
effectiveness depends on successful enforcement.
The no action alternative does not provide any long-term protection of
public health or the environment. Contaminants would continue to leach
into the aquifer; if the source strength does not remain constant, the
contamination plume could expand.
Aquifer Unit
The total plume capture option is a pump and treat system designed to
capture the entire contaminated plume as It leaves the landfill area by
use of extraction wells. The system would be designed to significantly
reduce the. contaminants in the aquifer at the landfill boundary. By
reducing the source of the contaminants to the offsite. plume the
contaminated groundwater would naturally attenuate to drinking water
levels. The treatment of the contaminated water can be handled by
different technologies. The treatment system can be very, effective in
reducing the contaminant levels in the discharge to background levels,
drinking water levels or ambient water quality levels. Each treatment
alternative provides a degree of treatment but only with proper operation
and maintenance of the system. Pump and treat systems described in the
FS have a design Itfe of 20 years.
The partial plume capture pump and treat alternative provides a system
similar to the full system but is designed to extract only the most
heavily contaminated portion of the plume. This system would allow
contamination less than the drinking water standard to continue to pass
offsite. The aquifer would take longer to attenuate and the cleanup
level would be the drinking water criteria. Discharges to the river from
the treatment unit.would be designed to meet the discharge ARARs for the
Spokane River, similar to the total capture system. This system would
also have a 20 years design life.
The alternative water supply system provides immediate protection for
human health. However, alternate water does not permantly reduce the
contamination in or entering the aquifer. The water system would require
normal maintenance.
Administrative restriction can be put in place to prevent the drilling of
new drinking water wells In or near the contaminated plume. This would
reduce the potential for consumption of contaminated water but would not
permantly reduce the contaminant .levels or migration of the pollutants.
43
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4. Reduction of Toxiclty. Mobil rty. or- Volume
This criteria is an evaluation of the effectiveness of the treatment
technologies that passed the screening -step. Several technologies are
applicable to the skimmings area part of the landfill and others are evaluated
for the aquifer unit.
Landfill Units
The excavation and offsite disposal of the skimmings would eliminate
approximately 23,500 cubic yards of source material. This reduction is
calculated to represent about 10 percent of the PERC loading to the
aquifer. Excavation and onsite land treatment or onsite incineration are
both technologies that can also be applied to the skimmings. Both would
reduce the PERC to near detection limits in the excavated waste. But
like the offsite disposal option, any contaminants in the soil beneath
the area would continue to migrate.
Capping the landfill units Is source control because it significantly
reduces the amount of water that passes through the waste units. Water
passing through refuse generates the leachate that moves the contaminants
into the underlying aquifer. However, capping is not considered a
treatment technology.
Neither administrative restrictions nor the no action alternative would
treat the contamination; toxicity, mobility, and volume of the
contamination would be unaffected.
Aquifer Unit
Extraction of contaminated groundwater (pumping) and subsequent treatment
options would reduce the concentration of contaminants migrating
downgradlent of the extraction wells. The reduction of the concentration
of contaminants effectively reduces the toxidty and volume of
contaminants in the groundwater. The mobility of the contaminants is
controlled upgradient of the well by the zone of influence created by the
pumping drawdown action.
The effect on the plume by the total plume capture or the partial plume
capture alternative would be similar. It would take longer under the
partial plume alternative to achieve the same results.
•
None of the remaining alternatives—monitoring, administrative
restrictions, alternative water supply, or no action—would reduce
toxidty, mobility or volume of the contaminants in the aquifer.
5. Short-Term Effectiveness
The short-term effectiveness of each alternative addressed impacts during
the time of Implementation. This period normally lasts from one to five years
and includes construction, start up and operation until the cleanup goals are
reached.
44
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Landfill Units
4
The short term effects from capping the landfill would immediately reduce
the risk of contact with contaminated soils or wastes and would reduce
the escape of VOCs. There could be some risk to workers' health during
construction of the cap.
Excavation of the skimmings with onsite land treatment or incineration
would not be effective in the short term, as there would be risks to
workers from construction and from the operation of the treatment systems
themselves.
Institutional controls would not protect human health, as people may
continue to use existing wells in the area of contamination. The no
action alternative would have the same result.
Aquifer Unit
Under the treatment alternative, groundwater would be pumped and treated
and discharged to the Spokane River. This alternative would in effect
control the offsite migration of contaminants past the landfill
boundary. It would not, however, pull existing downgradlent
contamination back to the landfill.
The water discharged to the Spokane River can be treated to meet
applicable offslte requirements. The short-term impacts of this
alternative is construction. Workers need adequate protection from the
volatile organlcs during well construction and operation of any treatment
process that will release VOCs. There should not be any short-term
Impacts to the community other than construction.
The alternative water supply limits consumption of contaminated
groundwater but does not reduce contamination. Since the municipal
alternative water supply system is already in place, no new construction
should be required, therefore, no short-term effects to health or the
environment.
Institutional controls would restrict the use of groundwater but would
not improve the groundwater quality. No construction would be required.
No action provides no short-term protection to health or the environment.
6. Implementabi1ity
The implementabillty of a remedial alternative considers the technical
and administrative feasibility of actually constructing the alternative to
make It work.
Landfill Units
No action has, as expected, the highest level of implementabillty. There
Is no construction required and no time consideration, but this
alternative does not meet ARARs.
Institutional controls or administrative restrictions would be nearly as
easy to Implement since they do not involve construction. Some of the
45
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restrictions need not be put into effect until the landfill is.closed;
others can be done earlier: The time required to implement the
restrictions depends on the length of time required to prepare and pass
local ordinances, file deed notations, or take other administrative
actions. However, administrative restrictions by themselves do not meet
ARARs.
All the landfill cap options use proven technology and would therefore be
the most implementable; construction time is estimated at 8 months to 1
year. Certain site conditions—steep grades in some areas, variable
weather—might have an impact on construction (some areas would probably
require regrading). To cap the refuse unit, the landfill can no longer
be receiving wastes. Capping the other units may occur sooner because
they are no longer receiving refuse. Capping would use conventional
construction equipment.
Of the skimmings excavation alternatives, offsite disposal would be the
simplest to implement. Conventional excavation equipment could be used
for the skimmings area, though special containers or transportation
methods might be necessary for the actual removal. Onsite Incineration
would be the next easiest to implement, though material handling and
mobilizing and Incinerator might present problems. Onsite land treatment
would require finding a suitable site (possibly the skimmings unit area),
and tests to determine the volatilization/treatment rate. The tests
usually require about 3 years of treatability studies. Full-scale
implementation might take 5-10 years, in addition to the 3-year land
treatment demonstration which also reduces its implementabi11ty.
Aquifer Unit
There are no implementation requirements for the no action alternative.
Institutional controls and restrictions, and alternative water could take
a year to coordinate among the different agencies. There are no known
limitations and no construction requirements identified for these
actions. A permanent alternative water supply is already in place, and
only limited construction to new homes and normal maintenance will be
required in the future.
The groundwater monitoring alternative could utilize the existing
monitoring well system supplemented with new wells as needed. There are
no known construction or permit limitations for this alternative. A
monitoring program is ongoing so there would be no time lag in
implementing it.
Aquifer conditions at the site are technically feasible for a pump and
treat system. Construction of extraction wells is possible with
treatment and finally discharge to the Spokane River. All pump and treat
options must meet groundwater withdrawal, treatment plant emission, and
point source discharge requirements. There are no major problems
anticipated which would affect implementation of any treatment
alternatives. Construction of the pump and treatment system will take
about two years.
46
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7. Project Costs
Present worth costs are used to evaluate and compare the cost of each
alternative. Present worth consists of the sum of the initial capital
costs and the discounted annual operation and maintenance (O&M) costs.
Table 7 gives a summary of costs for each of the units as detailed in the
Feasibility Study.
Landfill Units
The no action alternative would cost nothing and therefore be the least
expensive. Administrative restrictions have no present worth costs since
the costs are administrative such as passing ordinances.
Costs for capping depend on the type of cap chosen. The costs for the
landfill units are estimated in Table 7. For the refuse unit (the
largest and most costly one) a membrane and clay cap would cost an,
estimated $29 million, while a membrane or sol1/bentonite cap would cost
$22 million. - -
The costs for excavation alternatives for the skimmings unit are about $2
million for onslte land treatment, $12 million for offsite disposal, and
$22 million for onslte Incineration. In comparison, the cost of capping
the skimmings unit would be $530,000-$720,000.
Aquifer Unit
The no action alternative for this unit would have no construction
costs. Institutional controls similar to those for the landfill units
would have only administrative costs.
An alternative water supply, which already exists, has an estimated cost
of $200,000. The estimated costs for the aquifer alternatives are
presented in Table 7.
Groundwater monitoring costs are estimated as $320,000 for a 30 year
period.
Collection and treatment costs range from $3.6 million to $87 million,
depending on the level of treatment and whether plume capture is partial
or total. Partial .plume capture is as protective to human health and the
environment and Is cheaper to implement than the total capture system.
Modifying Criteria
The modifying criteria are used in the final evaluation of remedial
alternatives. The two modifying criteria are state and community acceptance.
For both of these elements, the factors considered in the evaluation are the
elements of the alternative which are supported, the elements of the
alternative which are not supported, and the elements of the alternative that
have strong opposition.
8. State Acceptance
Washington State Department of Ecology (Ecology) has been closely
involved with the development and review of the Remedial Investigation and
47
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TABLE 7
OLD BURN AND SEWAGE SLUDGE UNITS COST SUMMARY
Engineering and
Drslgn
Construct Ion
feral Ulna. «* Uo«l
S«rvlc*i During
Construction
Initial Cost
Subtotal
Annual OM
n of out
Projact m
•U
Haitorana
and
Clai Cap
720,000
7.200.000
3(0,000
MO, 000
• ,900.000
19,000
140,000
»,000,000
BIB
Soil and
Btntonlta
1)0.000
S.200.000
260.000
410.000
6. 400,000
IS, 000
140.000
6.SOO.OOO
Old Bum Unit
BIC
Hcafcran*
510,000
5, 100,000
260,000
410,000
6,100.000
15,000
140,000
6.400.000
. Senao* Sludo* Onlt
B] Bl UU
Hcabrana
Und 0«« Ha and
BestftcUon* >ctloo Clay Cap
140.000
1,400,000
70,000
110,000
1,700,000
J.OOO
2B.OOO*
1,600,000
U1B
Soil and
Bcnlonll*
110,000
1,100,000
&6.000
90,000
1.400,000
3.000
18,000*
1,400,000
01C
Ha*>rana
110.000
1.100,000
S7.000
91,000
1,400,000
3,000
21,000*
1,400.000
Ul Ul
Und Ufa No
Restrictions Action
..
-.
-.
—
..
, —
—
—
Praacnt worth baaad on M r«ara at 10 parccnt net discount.
-------
TABLE 7 (cont'd)
REFUSE AND SKIMMINGS UNITS COST SUMMARY
Engineering and
Design
Construct Ion
Permitting and
Legal
Service* During
Construction
*J Initial Cost
Subtotal
Annual MM
IV of OUt
Project m
RIA
Neebrane
and
Clar Cap
1,100,000
11,000,000
1.200,000
1.1100,000
18,000,009
110,000
1. 000.000
19,000.000
•IB
Soil and
Bentooll*
C*£
1,100,000
17,000,000
•50.000
1,400.000
n.ooo.ono
110,000
1,000.000
11.000,000
Refuse On It
RIC
Neafcrane
Cap
1,700,000
*
16,700,000
•40,000
1,100,000
11,000,000
110.000
1.000.000
. 11,000,000
SklMlngs Onlt
111 M SI*
Of 1 site
Land Use No RCRA
Restrictions Action Landfill
980.000
9,BOo,nnn
490,000
780,000
12,000.000
..
o*
11,000,000
SIB
Ons Ite
Tre«t»rnt.
ioo.ooo
1,500,000
74.OOO
120,000
1,900.000
16,000
I60.000b
1,000.000
SIC
Onslle
Inclneial Inn
970,000
I9.oon.ooo
1,400,000
970,000
jj.nm.ono
0
0*
22,000.000
S2A
Heetirane
•nd
Clar Cap
58,000
580,000
29.000
46,000
710,000
1.000
9,000*
720,000
S2B
Soil and
Bent on Ite
_C«E_
42,000
420,000
21,000
14,000
570,000
1.000
9,000*
5)0,000
S2C
Hnriian*
__£•£_
42,000
420,000-
21,000
11,000
5 10,000
1,000
9,000*
5)0.000
SI 54
Un.l llsr Ho
Rf.tr |< I Inns Action
••
."
--
.-
--
--
-.
'present eorth based on M rears at 10 percent net discount.
bPresent worth based on 10 fears at 10 percent net discount.
Note: Refuse unit cap costs are based on 115 acres and do not Include allowances for Methane gas control.
-------
TABLE 7 (cont'd)
AQUIFER UNIT COST SUMMARY
AIA
Discharge
to Spokana
P01M
Engineering and
Design NF
Construction
Permitting and
U,al
Services During
Construction
Initial Cost
Subtotal
in
O
Annual GUI
PW of 01 h
Project PM
Mr Imllcviles alternative not
a
A1BI
HlnUw
Treat »ent
500.000
4,700,000
*
110,000
170.000
5.100.000
700. 000
l.win.ooo*
6.BOO.OOO
feasible.
AIB1
Treatment
to Drinking
Hater Stds.
570,000
4.800.000
140.000
190,000
5,800,000
110,000
l.OOO.OOO*
7,600,000
A1B1
Treatment
to Hon-
deqradatlon
1,100,000
46.000.000
920,000
1 , 700,000
51,000,000
4,OOO,OOO
14,000.000*
B7.OUO.OOO
A2A
Discharge
to Spokane
POTH
49,000
150,000
11,000
10,000
iio.oon
420,000
1,600,000*
1.900,000
A2BI
HlnlHim
Treatment
210.000
2,000,000
98,000
78,000
2,400,000
140,000
1.200.0(10*
l.AOO.OOO
A7B7
Treatment
to Drinking
Hater Stds.
170,000
1.100,000
110.000
91,000
l.HOO.OOO
160,000
1,. 100 ,000*
4,100,0(0
A7B1
Treatment
to Non-
deqradat Ion
740.000
15,000.000
100,000
1,200.000
17,OOO,OOO
1,100,000
ll.OOO.OOO*
28,000,000
Al
Groundvater
Honltorlng
--
--
--
--
14,000
120,000
120,000
Tiesriit wn|t.h ba^ed on 10 years at 10 percent net discount.
Not*: Tim *'l lna(*J protect m tolnl for altrmate A4 our. |>io»l) l>r the client.
A4 A5
Alternative
W^ler Mo
i^I'l'Jl Action
2(1(1,ono
-------
Feasibility Study processes. Ecology commented on the RI/FS and worked with
EPA on the proposed plan. The comments from the state were an important
factor in EPA's decision to recommend an alternative that differed from the
recommendation in the Feasibility Study. The state strongly favors pump and
treatment of the contaminated groundwater plume as an interim measure until
contamination coming from the landfill is reduced to acceptable levels.
Although EPA has been working closely with Ecology to ensure that this ROD
Includes the state's comments, EPA, has not yet received the state's
concurrence letter.
9. Community Acceptance
The results of the public comment period and the discussion during the
RI/FS public meeting indicate that the residents who live near or have been
affected by contamination from the Norths1de Landfill support the proposed
plan with Its interim pump and treatment system. The community desires a
remedy which would begin treating the contamination as soon as possible. The
City of Spokane (the PRP) recommended that pump and treat only be Implemented
if contaminant levels In the plume were not lowered by the other closure
actions, specifically the cap. The community recognizes that none of the
alternatives, except for the pump and treatment system, will be Implementable
until the landfill closes. The pump and treatment system provides a
protection mechanism which Is not contingent on landfill closure.
The differences between the city's and EPA's recommended remedial actions
were highlighted in the proposed plan fact sheet and at the public meeting.
The resident community supported the EPA interim pump and treatment system
because It actually reduces the contamination In the aquifer, rather than
relying solely on natural attenuation. It was estimated that it would take
between five to ten years after the cap was in place before the natural
attenuation process would be noticed In the aquifer. The pump and treat
system can be Implemented in about 2 years.
Closure of the landfill with a cap, periodic monitoring, and other state
landfill closure actions were considered by all parties to be necessary parts
of the remedial action. Individual concerns about cost and institutional
controls (administrative requirements) were responded to in the attached
Responsiveness Summary.
-------
THE SELECTED REMEDY
. Description
The selected remedy for the Northside Landfill Superfund site consists of
the following elements:
Closing the landfill
0 Capping the landfill waste units
0 Pumping and treatment of groundwater
* Monitoring the groundwater
0 Providing alternative water
."• Enacting administrative restrictions
0 Controlling landfill gas emissions
Closing the Landfill
As soon as possible, the landfill shall be closed to stop the flow of
incoming refuse. The only disposal area currently in use has been designated
as the Refuse Unit.
An alternative disposal facility has been planned by the city as part of
a regional waste-to-energy project. The schedule for the new incinerator
facility is for operation to begin In late 1991. The start up of the new
waste-to-energy facility will allow Northside Landfill to be closed.
In the event that the new disposal facility is not available by
January 1, 1992, all Incoming refuse to Northside after that date will be
required to be disposed in new landfill units that meet the State Minimum
Functional Standards (MFS) for operating landfills. The MFS requirements
Include lined units with leachate controls. The new units would allow closure
of all the old units.
Capping the Landfill
The landfill must be capped as soon as practicable. A draft closure
plan, .evaluating the phased closure of all landfill units and including a
conceptual design for the cap, will be developed consistent with ARARs. If
phased capping is feasible, the closure plan will include a schedule for the
phased implementation. Construction of the cap must start consistent with
state MFS deadlines.
All of the cap designs in the feasibility study meet the MFS
requirements. The cap functions to contain the refuse units and to provide a
barrier to reduce infiltration into the wastes, thereby reducing groundwater
contaminant loadings. The feasibility study suggests this is the most
important remedial action for the long-term control of groundwater
contaminants from the landfill.
Although capping is a general requirement for the landfill, certain waste
units may not be contributing to the contamination problems. If adequate data
can be obtained to demonstrate that an area is not contributing to any of the
existing problem conditions, a variance (waiver) for the capping requirement
may be obtained for that particular unit. At the Northside Landfill, the
capping variance may apply to an area designated as the Old Burn Unit.
52
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The Old Burn Unit was the original area of the landfill which allowed
open burning. This area was closed in about 1960 and contains refuse that has
been partially burned. .Therefore, the waste in this unit may be
characteristically different from any-of the other waste units. Additional
study will have to demonstrate that contaminants of concern are not migrating
from this waste unit before the city applies for a capping variance for this
area.
Pumping and Treatment of Groundwater
The construction of an Interim extraction well system (pumping) and a
subsequent treatment facility for the extracted groundwater 1s necessary to
begin controls on the release of contaminants beyond the landfill boundary.
Contaminated groundwater Is the major route of exposure for human health and
the environment. The installation of a pumping and treatment system is
designed to serve these functions:
1. Establish a system which will control the migration of contaminants
downgradient from the landfill. The system must effectively control
the concentration for the contaminants of concern so that the
groundwater downgradient from the point of compliance meets ARARs;
e.g., the Maximum Contaminant Levels (MCLs) of the Safe Drinking
Water Act. The point of compliance Is the landfill property
boundary with performance monitoring to be located downgradient but
beyond the zone of influence of the extraction wells.
2. Treatment of the extracted groundwater. The treatment facility for
the extracted contaminated groundwater will have to reduce the
levels of all contaminants to required levels prior to discharge to
the Spokane River. If the discharge from this facility 1s through
the sewage treatment plant, the pretreatment requirements will also
have to be met. The river discharge Is considered offsite and,
therefore, must meet all federal, state, and local requirements such
as obtaining an NPDES permit.
Any air emissions from the treatment facility will have to meet
emission requirements. Design of the treatment facility will also
need to consider published risk assessments for VOC releases.
The pumping and treatment system Is considered an interim measure to
control contamination migrating from the landfill until such time as other
remedial actions, principally the cap, have demonstrated their effectiveness
at reducing the groundwater contamination. The pumping and treatment can be
discontinued when one year of groundwater monitoring indicates that
groundwater does not exceed the MCLs at the point of compliance for the
contaminants of concern, without running the pump and treat system. The
pumping and treatment system cannot be dismantled for an additional five years
after monitoring indicates it can be discontinued.
The contaminated groundwater plume that is downgradient from the landfill
boundary will not be extracted and treated and will be mitigated through
natural attenuation (flushing action).
The EPA review of the FS report recommended that an interim pumping and
treatment system be designed and constructed so that the groundwater meets
53
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standards at the point of compliance. The decision to include pump and treat
as a remedial action is an addition to the recommendation in the city prepared
Feasibi11ty Study. The rationale used to arrive at this recommendation is
summarized below:
1. The landfill cap cannot be completed until 1992 after the existing
refuse units are closed.
2. The effectiveness of the cap in reducing the contaminant loadings to
the aquifer has a lag time from 5 to 10 years (FS estimate) before
the aquifer will show lower levels of contaminants.
3. Once the cap is effective in reducing the contaminant loadings (5-10
years), it will take additional time for the contaminant levels to
fall below the drinking water MCL levels.
4. The citizens supported the EPA recommended pumping and treatment
system because it will get the cleanup started and not further delay
aquifer protection.
5. The Installation of the pumping and treatment system will start
groundwater remediation which could otherwise be delayed If closure
and capping schedules slip due to delays in the startup of the
waste-to-energy disposal facility.
6. The active system will also allow time for further, definitive
studies on the Old Burn Unit, which may not be contributing to to
the groundwater contamination problems and could therefore receive
an MFS variance. A change In the closure requirements for this area
could result In a cost savings for capping.
The pumping and treatment system described above Is similar to the
feasibility study alternative Identified as partial plume capture. The
partial plume capture pump and treat system was not recommended by the city.
EPA's conclusion is that the interim pumping and treatment system could
provide positive remedial action on a faster schedule, with more control, meet
the needs for treatment where practical, and be more protective of human
health and the environment without disproportionately higher costs. As soon
as other remedial measures, specifically the cap, become effective in
consistently lowering the contaminant levels to below MCLs at the point of
compliance, then the pumping system can be evaluated for shutdown.
Monitoring the Groundwater
A groundwater monitoring plan for long-term monitoring of the aquifer,
domestic water supply wells, contaminant plume, and performance of the
extraction well system must be submitted for approval as a part of the
remedial design. Until the long-term monitoring plan is approved by EPA, the
City of Spokane is currently conducting quarterly monitoring of the existing
monitoring wells and the 11 established domestic residential wells. The
long-term monitoring program may require construction of new monitoring wells.
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Providing Alternative Water •
The City of Spokane has continued to provide a source of potable water to
those residences whose domestic wells have been contaminated or become
contaminated above drinking water standards by the Northside Landfill. The
alternative water source must continue until the aquifer contamination is
reduced to the cleanup levels.
Any private wells currently in use that are adversely impacted by any of
the remedial actions may be eligible for supplemental alternative water. The
pump and treat system may alter the usefulness of several wells, requiring
their replacement or alternative supplies. The city Is currently providing
alternative water by extending the municipal water supply system. This system
Is currently meeting the requirements for potable, domestic use water.
Enacting Administrative Restrictions
Administrative restrictions or institutional controls need to be enacted
which will protect the landfill cap, monitoring wells, and the pumping and
treatment system. Restrictions should be placed on the construction of new
wells and the use of existing wells In the contaminated plume. These actions
must be part of the planning for Implementation of the remedial action.
Controlling Landfill Gas Emissions
The gas emissions from the landfill have to be actively controlled to
prevent offslte migration according to MFS requirements. This action must be
integrated into the closure plan and capping actions.
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STATUTORY DETERiMINATIONS
The selected remedy meets statutory requirements of Section 121 of
CERCLA, as amended by SARA, and to the extent practicable, the National
Contingency 'Plan. The evaluation criteria are discussed below:
Protection of Human Health and the Environment
The selected remedy will protect human health and the environment by
reducing the amount of contamination 1n the groundwater, reducing the exposure
routes by capping the landfill, and providing alternative water. The major
exposure route Is ingestion of contaminated groundwater, with several minor
secondary routes through air and direct contact.
The remedy reduces the exposure to contaminated groundwater during both
the short term and the long term. Short-term controls include:
1. Alternative water supplies to those with contaminated wells;
2. Construction of a pumping and treatment system to reduce
contamination levels to drinking water standards and control offsUe
migration; and
3. Placing a cap over the refuse units.
Short-term exposure will be reduced by preventing direct contact and
uncontrolled air emissions. Long-term control is provided by the cap, which
reduces the leachate loading Into the aquifer by controlling the source.
Administrative restrictions will be effective in keeping the long-term
exposure low by protecting the cap and monitoring wells system and controlling
use of .wells 1n the contaminated portions of the aquifer, until the aquifer
remediation Is complete.
The pumping and treatment system will be designed to reduce the toxicity,
and volume of the contaminants in the groundwater. Nearby residents affected
by contaminated groundwater, or by the action of the pumping and treatment
system, will receive alternative water supplies. The City of Spokane has
extended its municipal water system into the area and is supplying potable
water to those residences which have contamination in excess of MCLs in their
wells.
m
No exposure problems are expected during construction of any of the
remedial actions. Workers and residences can be protected by compliance with
adequate health and safety- plans and health and safety monitoring. None of
the activities proposed involves direct contact with acute hazards.
Attainment of ARARs
The selected remedial action also meets all applicable or relevant and
appropriate requirements (ARARs) that have been identified. No waiver of any
ARAR is being invoked for the selected remedy. The major ARARs are briefly
described below.
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The laws and regulations'of concern Include but are not limited to the
following:
1. Resource Conservation and Recovery Act (RCRA; 42 U.S.C. §6901), RCRA
regulations (40 CFR 261-280), Washington State Dangerous Waste
Regulations (WAC 173-303 and 70.105 RCW), and Washington State
Minimal Functional Standards for Solid Waste Handling (WAC 173-304
and 70.95 RCW).
Landfill closure requirements of RCRA and Washington State Dangerous
Waste Regulations will be attained by Installation of the landfill
cap to minimize leachate production, and operation of the
groundwater extraction wells to remove contaminated groundwater.
The selected remedy prevents further spread of groundwater
contamination. Closure of the Northside Landfill to State Minimum
Functional Standards will be evaluated to ensure consistency with
RCRA landfill closure standards.
The technology applicable for the landfill must meet the Washington
state standards for ongoing landfill operations, closure, capping,
leachate containment, and methane control. A variance for disposal
in a lined unit with leachate treatment is scheduled to be issued,
allowing disposal in the existing refuse unit until December 31,
1991. Other substantive MFS requirements must still be met.
2. Rules and Regulations of the State Board of Health Regarding Public
Water Systems (WAC 248-54).
The alternative drinking water supply currently in use is a
municipal system which is in conformance with these regulations.
3. Model Toxics Control Act (Initiative 97).
This is the state's operative hazardous waste cleanup law.
Regulations under this law are pending promulgation.
4. Safe Drinking Water Act (42 USC 300), and Primary Drinking Water
Standards (40 CFR 141).
Groundwater will meet MCLs, the appropriate health-based standards,
as the contaminated plume is extracted and leachate generation is
minimized. The selected remedy will prevent exposing the public to
contaminated drinking water by monitoring residential wells and
connecting an alternative supply when conditions require it.
Therefore, by monitoring, providing an alternate drinking water
supply, and restricting groundwater use, until the aquifer no longer
exceeds drinking water levels in the area, the selected remedy will
meet the requirements of these regulations.
5. Clean Air Act (72 USC 7401).
If an airstripping system is used, concentrations of contaminants in
the airstripper emissions will be required to meet the requirements
of the Clean Air Act. Flares for the methane gas extraction system
must also meet the requirements of the Clean Air Act.
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6. Clean Water Act (33-USC 1251). .
The selected remedy treats the extracted water to meet MCLs,
health-based standards, or Water Quality Criteria prior to
discharge, whichever is lower. Therefore, there will be no adverse
impact .on surface waters resulting from discharge of treated
groundwater, and requirements of these regulations will be attained.
Offsite Regulations
There are actions which will occur offsite which require compliance
with all laws and regulations. Such actions include storm drainage
and discharge of treated water to the Spokane River. These
discharges will be subject to the National Pollution Discharge
Elimination System (NPDES) effluent limits, pursuant to NPDES (40
CFR 122), NPDES Permit Program (WAC 173-220), and Water Pollution
Control Act (RCW 90-48), as a minimum.
Cost Effectiveness
The cost effectiveness of each remedial alternative was evaluated.
Closing and capping the landfill according to the State ARAR (Minimum
Functional Standards) represents the most expensive part of the selected
remedial action, approximately $30 million. However, this remedy also
represents the least expensive way to provide long-term source control. The
excavation and disposal and/or treatment of certain landfill waste units did
not represent a significant cost benefit over capping.
The construction of a partial plume extraction and treatment system for
mitigation of groundwater contamination 1s the best technical solution for
treating contaminants in the groundwater for these specific site conditions.
The partial plume system is as equally protective as the total plume capture
systems at substantially lower cost.
The specific cap material and the groundwater treatment system are not
specified to allow for analysis during the design phase. The costs of the
pumping and treatment system may vary greatly depending on how the system is
designed to meet the performance criteria.
Utilization of Permanent Solutions and Alternative Treatment Technologies
Alternative treatment technologies were generally considered unfeasible
for the refuse area of the landfill, because of the size of the source (345
acres containing over 5 million cubic yards of waste materials). Many of the
other alternative technologies are not yet proven for municipal landfill
leachate and were estimated to be more expensive for the same level of
treatment achieved by less costly alternatives.
Permanent treatment, along with alternative or resource recovery
technologies, was Included in the initial screening of remedial action
technologies. Several treatment technologies passed the initial screening for
the Skimmings Unit (a small part of the landfill). Based on the cost
effectiveness analysis, these treatment technologies were not selected. The
costs for alternative treatment technologies for the skimmings area were
considered disproportionately high compared to the cap, which was determined
to be protective of human health and the environment.
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Treatment was selected to mitigate the groundwater contamination
problems. Treatment of the extracted water will be designed to reduce the
contaminant loading and prevent their re-entry Into either the groundwater or
Into the surface water discharge. The final treatment technology has not been
specified but will be selected from those conceptually identified in the FS
during the design phase based on performance criteria.
Land Disposal Restrictions
The selected remedy does not require placement of RCRA hazardous wastes
either on or offslte. Therefore, the Land Disposal Restrictions do not apply.
Preference for Treatment as a Principal Element
Treatment is the selected remedy to mitigate the aquifer contamination.
Ingestion of the contaminated water is considered the primary route of human
exposure.
Treatment technologies were evaluated for the landfill source but were
not selected. Several factors make treatment unfeasible or too expensive for
the landfill units:
1. The size and volume of the landfill wastes would make excavation and
treatment difficult, expensive, and possibly hazardous to workers
onsite.
2. Alternative treatment technologies for effective onsite treatment of
landfill wastes are still experimental for the contaminants of
concern. The costs were significantly and disproportionately higher
for the reduction in risk.
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CONCLUSION
An extensive evaluation of the Northside Landfill site has resulted in
the identification of the problem (chlorinated organic, industrial solvents)
and proposed solutions. The exposure to the community has been controlled in
the interim with the installation of the municipal water supply. The costs of
the remedial actions are mostly for the closure and capping of the landfill
which are required under state law.
The selected remedy 1s expected to control the migration of contaminants
offsite, to reduce the contaminant loading rate to the environment, and to
protect public health and the environment. The result of the remedial actions
will be to return the contaminated part of the aquifer back to its
availability as a drinking water supply, to safely contain the material
disposed of at the Northside Landfill, and fully comply with ARARs.
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APPENDICES
RECORD OF DECISION
NXTHSIDE LANDFILL
IE,
Appendix A: Responsiveness Summary
Appendix B: Administrative Record Index
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Appendix A
NORTHSIDE LANDFILL RESPONSIVENESS SUMMARY
Overview
Northslde (North) Landfill is an operating municipal solid waste facility
in Spokane, Washington. The site is located on a 345 acre parcel between Nine
Mile Road and the bluff of Five Mile Prairie.
In 1981, the City of Spokane began an Investigation which identified
contaminated groundwater migrating off site and contaminated drinking water
wells In the area. In 1983, Spokane extended city water to those homes with
contaminated wells and later to the entire area northwest of the landfill.
In October 1984, the Northside Landfill was added to the National
Priorities List (NPL) because of contamination of groundwater. The NPL is a
list of hazardous waste sites across the nation designated for study, and if
necessary, cleanup under the Federal Superfund Program.
As owner and operator of the landfill, the City of Spokane was identified
as a potentially responsible party (PRP) and considered liable for
Investigation and cleanup costs. In 1986 Spokane began work on the Remedial
Investigation/Feasibility Study (RI/FS) which 1s a comprehensive study of site
conditions, hazards, possible exposure pathways, and cleanup alternatives.
Initially, the Washington Department of Ecology (Ecology) was responsible for
overseeing the work at this site.
In order to identify community concerns about the site, community
interviews were conducted in August 1987. Based on those Interviews, a
Community Relations Plan was developed which was published in November 1987.
On March 16, 1988, the U.S. Environmental Protection Agency (EPA) and
Spokane signed an agreement called a Consent Order to complete the RI/FS and
oversight of the work returned to EPA. Shortly after that the Community
Relations Plan was was revised by EPA to reflect new information. The final
RI/FS report was made available for public review in March 1989.
EPA's preferred alternative,which was presented in the proposed plan fact
sheet, dated February 28, 1989, is different from the recommended plan in the
Feasibility Study prepared by Spokane. The difference is that EPA's preferred
alternative calls for Installation of a treatment system which pumps and
treats contaminated groundwater as part of the initial remedy, whereas Spokane
preferred additional monitoring prior to installing a pump and treat system.
This document Includes a summary of comments and concerns raised during
the comment period held from March 1 to March 31, 1989, and a brief
description of community background and Involvement.
The comments received from citizens generally support EPA's preferred
alternative. Some concerns were expressed about how the construction of the
pump and treat system will affect the community, the cost of the system, and
the health risks. Spokane and other local officials expressed their belief
that immediate pump and treat will not be a cost-effective use of public funds.
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Background on Community Involvement and Concerns
The community living next to the landfill has been active sines 1976 and
in 1981 formed the Pinemeadows Homeowners Association to work on closing the
Northside Landfill.
The community interviews conducted by EPA in 1987, revealed the following
community concerns about the Northside Landfill:
Citizens are concerned that the aquifer will never be cleaned up.
Citizens were also concerned about the operation of the landfill;
problems Included Illegal dumping, odors, failure of the buffer
zone, and landfill height.
Homeowners who received alternative water supplies from the city
expressed concern that the costs will Increase making it
unaffordable to irrigate their property.
Citizens were also concerned that the landfill cleanup may have
adverse economic impacts on their property values. They were also
concerned that garbage rates will Increase.
Summary of Comments Received
Comments and questions raised during the Northside Landfill public
comment period on the proposed plan are summarized below and are grouped by
category. EPA received 23 letters from the public during the comment period.
As part of comment period, a public meeting was held on March 15, 1989,
at the Spokane City Council Chambers. About SO people attended this meeting
and 10 people gave public comment. The meeting consisted of a presentation by
EPA, and D^M Hill (Spokane's contractors), followed by a question and
answer period.
Questions Included the timing for installing the pump and treatment
system, the cost, the cap, and health concerns. Copies of the transcript are
available at the Spokane Public Library, Downtown Branch, and the City of
Spokane Engineering Services Library in the Municipal Building.
RESPONSIVENESS SUMMARY
Preferred Alternative
The following reflects the citizens' or agencies' comments which support
EPA's preferred alternative for cleanup of Northside Landfill. In addition,
eight citizens wrote letters of support with no comments or concerns expressed.
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1. The Washington Department of Ecology favors immediate pump and treat as one of
the first measures at the site as it provides an interim solution to controlling
contamination until the cap becomes effective and the landfill is closed.
Response: Support for the proposed pump and treat option is noted.
2. One citizen spoke in favor of the preferred plan and urged more stringent
administrative restrictions.
-<
Response: Administrative restrictions or institutional controls are designed
to protect public health and the environment and must also protect any
remedial action. Restrictions to protect the pump and treat systems will be
required. A typical administrative restriction would be to prohibit the use
of any private well which would reduce the effectiveness of the barrier wells
placed as part of the pump and treat system. Other possible administrative
restrictions that will be evaluated are whether the construction of new wells
in the contaminated plume, or reuse of wells already in the plume, can be
allowed. After the cap is in place, use of the landfill property will need to
be restricted to protect the integrity of the cap.
3. Several citizens wrote to support the proposed alternative but did not want any
more disruption to their lives with more pollution, noise or undue construction. The
concern was that the pump and treat system be designed and installed where it will have
the least impact on the neighboring community.
Response: The construction plan will not be ready for some time; however,
impacts on the community are a part of the plan review. Some noise and
disruption during a construction activity is expected, but efforts will be
made to reduce its impact on the neighborhood. Long term impacts, such as
noise or building location, can be controlled during design and is an element
considered in the review and approval process.
4. A local attorney wrote to express support for pump and treat because of Spokane's
repeated failures to comply with environmental regulations.
Response: The suggested failures of the City of Spokane to comply with
environmental regulations Is beyond the scope of evaluation for this study.
We were not aware of any environmental regulations that Spokane was violating
by conducting the study phase of this project.
5. Another citizen wrote to support the preferred alternative because cost of pump
and treat in the future will be even more and would come on the heels of costs associated
with the incinerator.
m
Response: Costs for construction have typically Increased with time. It
would be expected that the pump and treat system would cost more if
construction 1s delayed. The money for the closure and remedial actions at
Northslde will probably come from several sources. Cities generally issue
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revenue bonds for major construction projects. Because the Incinerator Is to
replace some landfill operations In the city and county, some of the revenue
obtained by selling the incinerator bonds is projected for use on Northside's
closure. It is expected that the city will also obtain money from other
sources. EPA does not direct responsible parties in their choice of funding
mechanisms for Superfund work.
The following comments were written to express disagreement with EPA's
preferred alternative for cleanup at Northside Landfill.
1. City of Spokane doesn't agree with that part of the preferred alternative involving
the pump and treat system. They advocate that a five year monitoring period before
installing the pump and treat system would be more cost effective. The City of Spokane
believes undue secondary impacts will occur if pump and treat system goes into effect.
The construction of the towers and pump and treat system will be noisy, and unsightly.
Spokane is also concerned that air contamination and surface water contamination will
occur because of releases from the stripping towers and discharge from the treatment
Response: The five year wait before Installing any pump and treatment system
is based on the assumption that the cap will have an Immediate and measurable
effect on reducing the amount of contamination reaching the aquifer. If a
reduction In the concentration of contamination in the aquifer would not occur
within five years (3 years after capping), the pump and treat system under the
City's proposal would still need to be installed. By beginning the design and
implementation of the pump and treat system now, the system would be
operational earlier and may cost less depending on Inflation and plume
migration.
After the pump and treatment system is In operation, reduction of the
contamination 1n the aquifer leaving the landfill can begin. The pump and
treat system can reduce the contaminant loading thereby reducing the size and
concentration of the plume off-site.
One of EPA's objectives is to permanently reduce the toxlcity, volume,
and mobility of the contamination. Groundwater Is currently being
contaminated by the landfill to levels above the drinking water standards.
This is considered an adverse effect on the groundwater and other potential
receptors of the groundwater, and is prohibited under state and federal
regulations. Capping can reduce mobility, but only treatment will permanently
extract the contaminants of concern from this site. A second objective is to
restore drinking water aquifers that are affected. The Spokane Valley
Rathdrum Prairie Aquifer Is a sole source drinking water aquifer. Our
evaluation Indicates that there is a high probability that the contaminated
portion of the aquifer can be restored to meet drinking water standards.
Construction will create some temporary conditions such as: noise and
traffic, but proper planning can reduce any long term conditions to acceptable
levels. Locations of above ground structures and the treatment plant can be
placed In areas that reduce undesirable impacts.
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Air contamination will.occur if.some type of air stripping is used to
treat the groundwater without any secondary adsorption system. Other types of
treatment are possible. With any treatment system, any releases to the air
would have to be below any health based standard set for the contaminants of
concern. .
Discharges of surface water from a treatment system will have to meet
water quality standards for its release. Treatment systems are available to
clean up the water to meet health and environmental criteria.
The purpose of pumping and treating the groundwater is to reduce the
contamination leaving the landfill area, restoring the usefulness of the
aquifer, and permanently reducing the contaminants of concern. The treatment
system and its dlscharge(s) are a part of the overall permanent treatment
remedy for the site. All parts of the treatment system will have to meet
health based standards.
2. Another citizen questioned the validity of the cap because natural geologic
structures in the area will allow lateral movement of any water, still allowing water into
the site. This same citizen suggested we allow the natural forces to flush the
contaminants out of the site instead of capping and that the environmental impacts of
remedy could be worse than doing nothing. This citizen did suggest however that, if the
plume does not respond as he predicted, to begin implementing the pump and treat.
Response: An evaluation of the lateral migration of water from the Five Mile
Prairie entering the landfill was done as part of the agency review of the
Feasibility Study. The well logs for the locations on the bluff show quite
uniform material down to the first aquitard layer. The clay aqultards were
found to be located at a lower elevation than the bottom of the refuse fill.
Therefore, any horizontal movement of infiltration would be below the level of
the refuse. If the groundwater does not move through the refuse, 1t will only
contribute to the aquifer as flow and would not contribute to additional
contaminant loadings to the groundwater.
Natural flushing action would allow contaminants to enter the environment
at an unacceptable rate. This action could take decades because of the size
of this landfill and the small amount of rainfall which generates the
leachate. Leachates would be generated for decades rendering the aquifer in
this area unusable. Leachate leaving the landfill totally uncontrolled is
contrary to current laws and regulations.
Capping the landfill is considered to be a requirement of the State under
the State Minimum Functional Standards for closure of a landfill. The
evaluation in the Feasibfl ity Study suggests that capping is the long term
solution to control the rate of contaminant release into the aquifer.
Currently that rate of contaminant release Is above health based
concentrations.
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Waiting before installing a pump and treat system would only delay the
corrective action needed to provide direct controls to restore the aquifer.
The Feasibility Study recommended installing the pump and treat system if
aquifer conditions didn't improve within five years. .If, the effects of the
cap did not demonstrate effectiveness during the five year period, a pump and
treat system would be required, only adding to the delay in cleaning up the
aquifer.
3. The Spokane County Health District recommends waiting until the cap has been in
place five years to determine if contamination was still stable or not growing.
Response: See previous answer.
4. Two state representatives wrote to express their concern for spending an additional
$4.1 million when health and environmental benefits were negligible.
Response: The $4.1 .million cost estimate for the pump and treat system
includes operation and maintenance costs for 20 years. With a pump and treat
system in place, the containment of the contamination may actually present a
cost savings in the overall cleanup activities. Also, If the cap is as
effective as the City represents, the pump and treat system will not need to
be operated for as long a period of time.
Health Risks
1. The City of Spokane states health risks at the site are minimal and the preferred
plan cannot be supported on the basis of protection of human health.
Response: The risk analysis indicates that the health risks are low if
organisms are not exposed to the contaminated aquifer. EPA prefers making
contaminated water safe to use again, which 1s protective of human health and
the environment. The alternative water supplied by the City protects human
receptors but alternative water 1s considered a temporary measure to protect
public health, and does not correct the problem.
2. The Director of Spokane's Water and Hydroelectric Services wrote to say that "no
citizens living within the plume are using that water for household use." therefore, health
risks are low and the pump and treat system is unnecessary.
Response: See previous answer.
3. A citizen requested more information on long term health effects.
Response: EPA's risk analysis determined that both long and short term health
risks were very low. The Federal Department of Health and Human Services -
Agency for Toxic Substances and Disease Registry (ATSDR) also did not
recommend any long term health studies based on their Health Assessment of the
site. Local, state and federal health agencies can Initiate health studies at
any time together or independently, but based upon the very low exposure
potential for area residents at or near the site, they are not now
recommending such a follow up.
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4. A representative of Citizens for a Clean Environment wondered if bonds were
being posted to protect the public health and welfare (uncertain if she meant at Northside
or in relation to incinerator).
Response: EPA's Superfund Program is.required to work with the PRP to protect
the public health and the environment. This normally does not require that
special bonds be posted to protect public health. EPA will provide oversight
on the remedial action work to ensure that it complies with the laws and
approved plans. If conditions change that require a change in the remedial
action, this will be Immediately evaluated. Both EPA and the City have
mechanisms In place to deal with emergencies and/or unanticipated changes in a
project.
5. A citizen supports delaying installation of pump/treat because risk is to low.
Response: The alternate water system that is in place is for the protection
of human health. However, alternate water is not considered a permanent
solution to the cause of the problem and it Is not the only factor
considered. Currently there are no administrative restrictions to prevent a
new well from being installed in the contaminated plume or protecting a well
already in use from an unexpected plume shift. Using a new well in the plume
area would add a level of risk to those using the contaminated water. Also
see answers to Question 1 of this section.
Cost
1. The City of Spokane states that the cost of pump and treat adds undue burden on
taxpayers and is an unnecessary cost in conjunction with capping.
Response: The pump and treat system Is a cost for mitigating groundwater
pollution problems originating from the Northside Landfill. The costs in the
Feasibility Study are estimated costs based on projected remedial actions.
The cost of the pump and treat system is a part of the total cost. If the
capping actions turn out to be adequately protective of the environment, then
the interim pump and treat system can be shut down. If the pump and treat
system contains the plume, It may save citizens money 1n that they could use
their wells again instead of purchasing water from the city.
2. A citizen asked how much of taxpayers money has been spent on the site to date.
Response: EPA has spent an estimated $120,000 and the City of Spokane's costs
are estimated at $1 million. Ecology has also expended costs at this site in
excess of $13,000. The .city of Spokane has been doing the actual field work.,
such as installing the monitoring wells. EPA's and Ecology's costs are for
oversight of Spokane's work. Money spent by EPA is from the federal
Superfund. "The money In the Fund comes from taxes on chemical manufacturing
industries and federal tax sources.
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3. Another citizen questioned how the closure will affect garbage rates in the city.
Response: EPA has ho way of knowing whether garbage rates will be affected by
the landfill closure. Any such decision will have to be made by the city of
Spokane.
4. What will be the actual costs — are all costs discounted to present costs?
Response: Final costs cannot be calculated until final design plans are
approved. The Feasibility Study includes cost estimates for the various
alternatives. These cost estimates are further refined by projecting
operation and maintenance costs over the next 20 to 30 years. The projections
are estimates for what It will cost as money Is required In the future. These
projected future costs include Interest, Inflation, and other economic
factors. Rather than use future dollar costs for these estimates, all future
costs use today's dollars or present worth. The cost estimate for the
preferred plan is approximately $35 million.
5. The City of Spokane Water and Hydroelectric Services Director wrote to say EPA
is requiring City to do- expensive cleanup on a "relatively minor" problem.
Response: Sites which are placed on the National Priorities List (NPL), are
known to present some type of threat to public health or the environment and
are not considered minor problems by EPA. The state requirement to properly
close a landfill, thereby controlling environmental releases applies to
Northslde and other landfills In the state. The actions necessary to
undertake these tasks are required of Spokane whether or not the landfill Is a
Superfund site. The cost of just the required cap for this closure is
estimated to be $25 million and represents about 80% of the cost of the
proposed remedial action. The decision to implement a pump and treat system
to mitigate a pollution problem and begin to restore a valuable drinking water
aquifer Is an Important aspect of'the final site closure and remediation.
Environmental Risks
1. The City of Spokane does not believe other environmental receptors are exposed or
will be exposed in the future, therefore, pump and treat is not necessary because risks
don't exist.
Response: Since the Installation of the municipal water supply, no specific
environmental receptors have been Identified. However, the environmental
risks are not the only factors In evaluating a remedial action. (See answer
on Page 6, Health Risks, Question 1).
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Public Participation
1 . A citizen expressed.concern that being expected to respond to the Feasibility Study
was unreasonable because it was too technical. The commentor requested assistance on
this and future projects.
Response: EPA has attempted to keep the community actively involved in the
evaluation process through fact sheets and informational meetings because of
our concern over the complexity of this study and the Superfund process. In
addition, under the Superfund Program, Technical Assistance Grants (TAG)
recently became available to groups effected by Superfund sites. For each
site on the NPL a TAG of up to $50,000 1s available for use by community
groups to hire a technical advisor to help them understand the Superfund
process and to aid them in commenting on technical documents relating to the
site. •
An information package on applying for a Technical Assistance Grant is
available at the Spokane Public Library, Downtown Branch, as well as the City
of Spokane Engineering Services Library in the Municipal Building. You can
also contact EPA's Technical Assistance Grants Coordinator, Dwlght Davis, in
Seattle at (206) 442-0603.
EPA and Ecology have conducted many activities throughout the project in
order to keep the community Informed. A 11st of these activities can be found
on page 12 of this document.
Landfill Gas
1. A citizen suggested pumping the gas out of the landfill which should take care of
the volatile organics that are contaminating the groundwater.
Response: The landfill will generate methane gas for a long time as the
biological degradation continues. Controls for the collection and treatment
of the methane will provide conduits for the other volatile gasses to escape
the landfill. Vapor extraction was considered In the Feasibility Study
evaluation and reviews, and it was determined that very little reduction in
the pollutant loadings could be accomplished in this manner. Vapor extraction
will occur as a passive part of the gas control system and is expected to help
control off-site migration. The landfill cap will also be designed to reduce
the movement of volatiles into the soils.
Other
m
1. Will the pump/treat system reduce well yields in areas outside the plume?
Response: The Spokane Valley Rathdrum Prairie Aquifer is a very productive
aquifer, therefore, reduction In well yields Is not expected. The conceptual
design in the Feasibility Study uses pumping rates that probably would not
A-9
-------
have any reduced yield effect on any private wells. A few private wells may
have pumping restrictions placed on them to prevent their reducing the
efficiency of the operation of the pump and treat system, but these wells
would have, to be located close to the extraction system and currently are no
used.
2. Several citizens have concerns over the water rates and volume of water received
since they haven't been able to use their wells, have had to purchase city water, and the
volume of provided water has been less than they want. They are concerned that after
their contract expires they will have to pay more for city water then it would cost them
to use their own wells. They believe the water problem isn't theirs so they shouldn't be
penalized. What can be done to help them continue to receive water at a reasonable rate
until they can use their wells again.
Response: A purpose of the remediation effort is to restore the usefulness of
the aquifer that has been Impacted. If this takes longer than the remaining
five years of contracted water. It Is up to the city to negotiate another
agreement. Alternative water is Included In the remedy because some private
supplies have been adversely Impacted by the groundwater contamination.
Pumping Is designed to restore the aquifer for all uses. Once restored then
homeowners can evaluate the best system for their water supply.
3. A citizen from Citizens for Clean Air asked; Will the same problems occur at the
ash landfill for the incinerator? Also, what is being done to recycle or reprocess items in
the waste stream to prevent further pollution? She also asked: How is this affecting
property values; Are bonds being posted to cover periodic testing of incinerator for 50 -
75 pollutants? Would a plastic cap really work when gophers abound in the area?
Response: The design of a new ash landfill will be required to follow state
solid waste regulations which have been established to control all
environmental Impacts. Recycling 1s an Issue beyond the design of corrective
actions at the Northside Landfill.
The Feasibility Study did not address the Impact on property .values since
this Is not part of the Superfund remedial action. After the remedial actions
have been taken, then the county may evaluate property values if there are
long term Impacts on them.
The Northside Landfill 1s not a part of the incinerator project. This
effort Is to close this landfill and use other alternatives for solid waste
management. If any ash from the Incinerator does get disposed of at Northside
Landfill, it will have to be in an area that meets all the new requirements
for disposing that kind of waste.
The use of a plastic membrane as part of the landfill cap will have to be
designed to withstand the effects of the local environment. Membrane caps
have been used effectively In many different situations Including areas where
burrowing animals live.
A-10
-------
4. Another citizen wrote that the proposed Incinerator should be moved downwind of
Spokane, not upwind as scheduled.
Response: The location of the incinerator is beyond the scope of this
project. This comment has been directed to the city/county waste energy
office.
5. How long will the cap last?
Response: The cap will be designed as a permanent closure action. For cost
projections a 30 year period Is utilized. The integrity of the cap will
require periodic evaluation and will require annual maintenance. Most
projections for remedies do not extend beyond 30 years, but if the design is
proper, the cap will remain effective beyond the 30 year design period.
6. A citizen asked, what government body is responsible for making Northside Landfill
a Superfund site, and how do the problems at the site compare to a privately owned
landfill. She also asked if the problems at Northside were increased by government
negligence or inaction.
Response: The U.S. Environmental Protection Agency is the agency responsible
for designating Superfund sites and placed the Northside Landfill on the
National Priorities List. This designation 1s applicable to sites whether
they are publicly or privately owned.
There are certain kinds of environmental problems associated with
landfills regardless of ownership. The impact of a particular problem such as
leachate may be a greater problem at one site when compared to another because
of specific site conditions.
EPA does not believe that government actions have contributed to the
problems at the landfill. Activities to date have been focused on identifying
the problems. Actions will now begin to focus on remedies to those problems.
7. How much garbage is being dumped at the site?
Response: The dty has estimated the average amount of refuse dumped per day
is 500-600 tons.
8. Homes between the plume boundaries and the Spokane River are still on private
wells. These homes should receive public water to reduce any risks of exposure that could
occur.
»
Response: All of the homes that are near the plume or that may be impacted by
the plume have access to alternate water. If the plume should shift
additional areas may need to be supplied; however, pumping should reduce this
risk. There 1s no reason to supply municipal water to residences that are not
impacted by the site. Well monitoring will determine if any changes occur in
the size or location of the plume.
A-ll
-------
COMMUNITY RELATIONS ACTIVITIES AT
NORTHSIDE LANDFILL
Community relations activities conducted at the Northside Landfill to
date have included: ' . .
March 1985 — Ecology took lead responsibility for site including
community relations.
August 1987 — Community interviews were done by EPA and the
contractor for Draft Revised Community Relations Plan.
November 1987 — Draft Revised Community Relations plan submitted to
. EPA by the contractor.
May 12, 1988 — Fact Sheet was distributed announcing a consent
order between EPA and Spokane to complete the Remedial Investigation.
September 1, 1988 — An EPA Fact Sheet was distributed announcing a
public meeting on RI results and to provide a written overview of
results.
September 15, 1988 — EPA held Public Information Meeting on RI
results. Three people attended.
February 28, 1989 — EPA distributed a Fact Sheet on proposed plan
and announced public meeting on March 15, 1989.
February 28, 2989 — EPA put a paid advertisement In Spokesman
Review on public meeting.
March 15, 1989 — EPA held a public meeting on the proposed plan.
Approximately 45 people attended and 10 people gave oral comments.
A transcript of this meeting Is available at the Spokane Public
Library and the Engineering Services Library In City Hall.
March 1-31, 1989 — Public comment period held on proposed plan.
EPA received 23 letters during the public comment period.
A-12
-------
Appendix B
U.S. ENVIRONMENTAL PROTECTION AGENCY
REGION 10
1200 Sixth Avenue
Seattle, Washington 98101
ADMINISTRATIVE RECORD INDEX
for
NORTHSIDE LANDFILL
Spokane, Washington
July 6, 1989
B-l
-------
INDEX TO MINIM SI RAT IVE RECORD FOR NORTHSIOE LANDFILL
..LJLUJ^^hU
Jj Preliminary Assessment Report
00000001. Preliminary
assessment report
00000002. Preliminary
assessment report
00000003. Preliminary
assessment report
00000001.
Preliminary
assessment report
UOUOUOOb. Preliminary
assessment report
Preliminary assessment form
Tentative disposition form
Preliminary assessment summary
Preliminary site inspection report
Disposition lorm
5/80 2 Neil Thompson, EPA
7/80 I Neil Thompson. EPA
8/22/84 5 EPA
1/18/85 37 Thomas A. Tobin, Ecology ft John Osborn.EPA
Environment
4/2/85 2 Robert Kiev, EPA
^. Site Investigation Reports
0000000(<.
Site investigation
rpports
00000007. Site investigation
reports
00000008. Site investigation
reports
0000000'). Site investigation
reports
Site inspection report
Hazardous waste sites evaluation of
t)3)l-cleanup repuirements
Potential hazardous waste site
inspection, memo
Sample analysis review
5/6/80 8 Jim Hileman. EPA
8/1/80 2 J. C. Willman, EPA
8/1/80 4 James Hileman, EPA
8/8/80
C. Wilson
CM
PO
John Barich
3. NPL Listing and Comments
00000010. National Priorities The Site Itself, physical data and
listing and comments maps
Q0c.# f i 1 e Type/Description
4/3/84 6 James Maurn, Jim Oberland,
both authors
Date tf Pages Author/Organization Addressee/Organ! zat i on
-------
00000011. National Priorities
listing and comments
00000070. NPl Iisi ing and
Comments
00000080. NI'L Listing and
comments
OOUOU082. NI'L listing and
comments
00000083. HPL listing and
r comments
Letter re proposed action on Northside 8/16/84 2
Landfill
Summary of comments and response No date 4
Letter re request for removal of the 11/20/84 3
Northside Landfill from the proposed
national priorities list
Federal Register, Vol. 49, No. 200. 10/15/84 :n
pp. 40320-40352. Proposed Rule,
NPL listing
Federal Register, Vo. 51, No. Ill, 6/10/86 45
pp. 21054-21098. NPl Listing.
final rule and proposed rule
Kathy H. Davidson, EPA
Ken Bock, WA Planning &
Community At fairs Agency
Terry L. Novak, City of
Spokane, C. Scott Parrish. EPA
lerry L. Novak, City of
Spokane
EPA
EPA
Russ Wyer, EPA
4,. Slale/PRP Cooperative Agreements
0000001.?. State/PRP Cooperative Agreement between WA Dept. of
Agreements ' Ecology and City of Spokane,
nnOOOO(!X.' State/PRP Cooperative Agreement hetween City of Spokane
Agreements and WOOE related to CH2H Hill
Landfill Monitoring Study
2/11/86
3/14/86
lOp.
Terry L. Novak, City of
Spokane
Marilyn 3. Montgomery
City of Spokane
John D. Littler, WA St.
Dept. of Ecology
Frank Gardner
WDOE
5. Mult-Site Cooperative Agreements
00000013. Hulli-site coopera-
tive agreements
00000014. Multi-site coopera-
t ive agreements
;..[ iie
00000015. Multi-site coopera-
tive agreements
Letter re proposed action on Northside
landfill
8/16/84
10/22/84 11
Kathy M. Davidson, EPA
WDOE
Ken Bock, WA Planning &
Community Affairs Agency
EPA
Federal Assistance Application Form
with "project narrative statements, budget
breakdown, forward planning activities, letter from Attorney General Office regarding Cooperative Agreement between US
EPA and Stale
!YDe/Desctiotion
Letter regarding cooperative agreement
between US EPA and Stale
Date tt Pages
2/27/85 4
Author/Organization Addressee/Organization
Charles B. Roe and Charles Andrea Beatty Riniker,
K. Oowtliwrtile. Office oF DOE
the Attorne-y General
-------
OOOOOOUi. Multi-site coopera- Letter will* attached amendment; Federal 3/11/85 15 Lynda Brothers. WOOE
live agreements
Assistance Application; project
narrative statement
00000017. Multi-site coopera- Letter regarding finalization of
00000016.
00000010.
t ive agreements
Multi-site coopera-
tive agreements
Multi-site coopera-
tive agreements
statements of work for the Northside
and Greenacres 1-andfills
Memo re Superfund cooperative agreement
No. V-000283-01
Letter with attached amendments;
Federal assistance application form;
statement of work; agreement between
WDOE and City of Spokane
'00000020.
OOUOUOiM.
Multi-site coopera- Amendment to cooperative agreement
live agreements No. V-000283-01
Multi-site coopera-
tive agreements
Statement of work, cost detail
0. Work Plans/Assionments/Amendments
00000022.
000000^.
00000025.
OOOOOOB9.
00000000
uoomui'i i,
Work plans and
assignments
Work plans and
assignments
Work plans and
assignments
Work Plans and
assignments
Work Plans and
assignments
Work Plans and
assignments
Groundwater quality studies—
background and study approach
Forward planning report
Feasibility study work plans, drafts
feasibility study work plan
comments on feasibility
study work plan
Type/Description
Draft CH2M Hill
Site Safety Plan
4/16/85 2 Dan Sw'enson. WDOE
No date 3
8/2/88
Ernesla Barnes, EPA
Neil Thompson, EPA
12/31/85 2 Kathryn M. Davidson, EPA Oddvar K. Aurdal, EPA
1/16/86 16 John D. Littler. WDOE
WDOE
2/11/83 3 City of Spokane
3/85 38 Colder Associates
No date 13 City of Spokane
6/30/88 12 CH2H Hill
Dave Kargho
WDOE
Ernest Barnes. EPA
2/21/86 2 Kathryn M. Davidson, EPA Arv Aurdal. EPA
WDOE
EPA
City of Spokane
Neil Thompson
EPA
Date ti Pages Author/Organization Addressee/Organization
3/88 17 p CH2MHill City of Spokane
-------
Remedial invesliu.ation
00000021).
00000027.
0000002R.
00000029.
00000088.
[00000089.
00000090.
00000091.
00000092 ,
00000093.
8. Feasibi
00000030.
0000094.
Uoi*
Remedial
investigation report
Remedial
investigation report
Rpmpdial
investigation report
Remedial
investigation report
Remedial
Investigation report
Work Plans and
assignments
work Plans and
assignments
Work Plans and
assignments
State/PRP Coopera-
tive Agreements
Remedial Investi-
gation Report
lily Study
Feasibility study
Feasibility study
File
Water well reports, with attached maps
and graphs
Suggested test wells and map
Suggested test wells
Remedial investigation with appendices
Supplemental RI Addendum
feasibility study work plan
comments on feasibility
study work plan
draft CH2M Hill
Agreement between City of Spokane
and WDOE related to CH2M Hill Landfill
Monitoring Study
RI Final Report
Public comment on feasibility study
Uraf.t Feasibility Study
Type/Description
5/18/77 15 Dept. of Conservation &
Development
10/83 2 Unknown
11/83 1 Unknown
10/86 119 CH2M Hill
7/88 95p CII2M Mill
6/30/88 12 CH2MHill
8/2/88 2 Dave Kargbo
HUOE
3/88 17p CH2MH111
3/14/86 (Op Marilyn J. Montgomery
City of Spokane
11/88 34bp CH2H Hill
6/87 241 CH2M Hill
8/15/88 294p CH2M Hill
Patp "j^es A"thpr/0rgani*ation
WDOE
City of Spokane
City of Spokane
City of Spokane
Neil Thompson
EPA
City of Spokane
Frank Gardner
WDOE
City of Spokane
City of Spokane
City of Spokane
Addressee/Organisation
000009'.. Feasibility study
00000128. Feasibility Study
Feasibility Study North Landfill
Feasibility study public hearing
11/88 330p CH2M Hill
03/15/89 3p UDOE
City of Spokane
-------
'I-. .t
; ._R_i/JL5.
00000031. (orrespondence Letter re remedial investigation report
rp remedial investi-
gation feasibility study
00000032. Correspondence re Letter re applicable or relevant and
remedial investiga- appropriate requirements
lion feas'ibility study
00000090. Rl/fS correspondence North Landfill Supplemental RI/FS
Monitoring Well MW-W Relocation
10. Comments - Rl/FJ
00000097. Comments - RI/FS Review of Northside Landfill Rl/FS -
r Risk Assessment
6/28/85
00000098. Cnmmpiits -RI/FS
Comments on Draft FS
1/26/88 7p
7/10/87 2
Terry Novak, City of
Spokane
5/22/87 1 Neil Thompson, EPA
James S. Correll
Ch2M Hill
Dana Davoli/EHA
00000099. Comments - RI/FS Response to 8/11/87 letter
8/11/87 6p Peter Kmet
WOOF.
9/25/87 35p Phil Williams
Russ Wyer. EPA
Fred Gardner, WDOE
Neil Thompson
EPA
Neil Thompson
EPA
Phil Williams
City ol Spokane
Peter Kent
00000100. (nmmpnts - RI/FS
00000101. Comments - RI/FS
Preliminary comments on CH2M Hill's
RI/FS proposal
List of Technical items to consider
before completing RI/FS
11/23/87 6p
OOOUOI03. Comments - RI/FS DOE comments on Northside FS
IJO£" MJfi Type/Description
00(100)0-1. Comments -RI/FS Letter containing comments on RI
11/30/87 2p
00000102. Comments - RI/FS Letter containing Northside RI comments 8/7/88 5
9/8/88 8p
Date if Pages
10/17/88 19
Marsha Beery
EPA
Marsha Beery
WOOE
Neil Thompson
City of Spokane
Dave Kargbo
WDOE
Author/Organization
Neil Thompson
EPA
Jerry Neal
Lukins and Annis
Washington Trust
Financial Center
Phil Williams,
City of Spokane
Phil Williams
City of Spokane
Neil Thompson
EPA
Addressee/Organization
Phil H. Williams
City of Spokane
(0
00000105. Comments - Rl/FS DOE comments on Northside RI
10/17/88 3p Have Kargi>o
Neil Thompson
-------
File
Type/Description
/mthor/Orqaniiatlon Addressee/Organ! latIon
~ - - , ,
00000106.
00000129
00000130
00000131
00000132
' 00000133
00000134
00000135
00000136
00000137
00000138
00000139
OOOOOHO
00000 HI
00000142
Comnents
Comnents
Comments
Comnents
Comments
Comments
Comnents
Comments
Comnents
Comments
Comnents
Comments
•Comments
Comments
Comnents
- RI/FS
- RI/FS
- RI/FS
- RI/FS
- RI/FS
- RI/FS
- RI/FS
- RI/FS
- RI/FS
- RI/FS
- RI/FS
- RI/FS
- RI/FS
- RI/FS
- RI/FS
Northside Landfill RI/FS - Response
to Agency Comnents on FS
Comments on results of RI/FS
Comments on results of RI/FS
Comnents on results of RI/FS
Comments on results of RI/FS
Comnents on results of RI/FS
Comments on results of RI/FS
Comments on results of RI/FS
Comments on results of RI/FS
Comments on results of RI/FS
Comments on results of RI/FS
Comments on results of RI/FS
Comments on results of RI/FS
Comnents on results of RI/FS
Comments on results of RI/FS
| yci^v ^_
12/16/88
03/08/89
03/13/89
03/H/89
03/15/89
03/17/89
03/20/89
03/21/89
03/27/89
03/27/89
03/28/89
03/28/89
03/29/89
03/29/89
03/29/89
?r r o*jc j
54p
1P
IP
1p
1p
1p
1p
1p
2p
1p
1P
3P
2p
2p
1p
Phil Wit I alms
City of Spokane
Dennis K. Kroll
Spokane County
Health District
Nancy Bowen
Jean Silver
UA State Representative
John G. Bjork
City of Spokane
Shirley Rector
UA State Representative
Eric Cut birth
Allan A. Bonney
Attorney at Law
Mr. and Mrs. James Kirk
John G. Bjork
City of Spokane
Mary F. and John T.
Uhalen
Anita S. Messex
Janel and T.W. Dudley
City of Spokane
Phil H. Williams
Environmental Programs
Jerry Rounsvllle
Nell Thompson
EPA
Nell Thompson
EPA
Neil Thompson
EPA
Nell Thompson
EPA
Nell Thompson
EPA
Nell Thompson
EPA
Nell Thompson
EPA
Nell Thompson
EPA
Nell Thompson
EPA
Nell Thompson
EPA
Neil Thompson
EPA
Nell Thompson
EPA
Nell Thompson
EPA
Nell Thompson
EPA
Neil Thompson
EPA
-------
Doc*
Hte
Type/Description
00000 U 3
OOOOOK4
OOOOOU5
OOOOOU6
OOOOOU7
e OOOOOU8
00000 U9
00000150
00000151
00000152
00000153
Comments
Comments
Comments
Comments
Comments
Comments
Comments
Comments
Comments
Comments
Comments
- RI/FS
- RI/FS
- RI/FS
- RI/FS
- RI/FS
- RI/FS
- RI/FS
- RI/FS
• RI/FS
- RI/FS
• RI/FS
Comments
Comments
Comments
Comments
Comments
Comments
Consents
Comments
Comments
Comments
Comments
on results
on results
on results
on results
on results
on results
on results
on results
on results
on results
on results
of
of
of
of
of
of
of
of
of
of
of
RI/FS
RI/FS
RI/FS
RI/FS
RI/FS
RI/FS
RI/FS
RI/FS
RI/FS
RI/FS
RI/FS
*"*»»
03/30/89
03/39/89
03/30/89
03/30/89
03/30/89
03/30/89
03/30/89
03/30/89
03/30/89
03/31/89
M/04/89
IP
IP
1p
1p
1P
1p
1P
IP
IP
*P
2p
Date » Pages Author/Organ! lat \ on Addressee/Organ! nt I on
Margaret Minor
Richard 0. Harris
Mr. and Mrs. Paul Olson
Marilyn Rider
Bradford H. Baugh
Thomas and Nettlt PelIon
Veila N. Kenny
Patrick S. Lanegan
Ray E. Casselman
Otto L. Shumscher
k
Glenn and Marilee Neher
Nell Thompson
EPA
Neil Thompaon
EPA
Neil Thompaon
EPA
Nell Thompaon
EPA
Neil Thompaon
EPA
Nell Thompaon
EPA
Neil Thompaon
EPA
Nell Thompson
EPA
Neil Thompaon
EPA
Nell Thompaon
EPA
Nell Thompaon
EPA
CO
to
-------
11. Sdnipl inu. Plans
U0000033. Samp) ing plan
00000107. Samp)ing plan
00000108. Sampling plan
Groundwater sampling and analysis plan,
draft
Field Sampling Plan
North Landfill. City of Spokane. WA.
Draft Quality Assurance
Project Plan - Supplemental
RI North tandfill
11/86 45 City of Spokane
3/88 62p CH2H Hill
3/88 I5p OtfMHill
•UOOOOIOS). Sampling Plan letter commenting on sampling plan 4/13/88 3p
Dave Kargbo
WUOE
Nell Thompson
EPA
\'£, Permi 1 and Permit Application
00000015.
Permit and permit
Application
tetter regarding Norths ide landl ill
Permit Application; copy of sanitary
landfill permit application; addendum
00000110. Permit and permit Amendment of Solid Waste
Application Disposal Site Permit
3/29/79 15
7/8/88 15p
James t. Haurn, WUOE
Mary Q. Luther
Spokane County
Health District
John Anisetti,
County Health District
Phil Williams.
City of Spokane
HA
13. Reference Materials/Listing of Guidances
00000030. Reference materials; Guidances Inr administrative record;
listing of guidance actual guidance can be found at EPA
File
Type/Description
00000 111
Reference materials Guidance Memorandum
listing of guidance on Use and Issuance of
Administrative Orders under Section
I06(al of CERCIA
No date 2 Neil Thompson, EPA
Date It Pages Author/Organization Addressee/Organ! tat ion
9/15/87 37p. Lee M. Thomas
EPA
Regional Administrators
Regions I-X
000001 li* Heftrc'iice materials delegation of Remedy
listing of guidance Selection to Regions
3/21/86 4p J. Winston Porter
Regional Administrators
-------
DOUOOin KHvrence materials
H, Commun ity pcljitions
000000:<7, Community relations
UOOOUOW. Community relations
OOOOOOiW. Community relations
00000040. Community relations
ROD:Des Moines TCE, U 7/86 48p
(used as Directive)
News release regarding Northside Landfill 10/7/85
Superfund designation
Letter with attached community 10/11/86
relations plan—first draft
News release re December 11 meeting 12/4/86
Public meeting notice 12/11/86
EPA
Dennis Mine, City of
Spokane, Refuse Division
George Cole, Media West Phil Williams, City
of Spokane
City of Spokane
Phil Williams, Spokane Office
of Environmental Programs
000000-11.
00000008.
OOOOUIH.
000001 IS.
00000 IK,.
0000012r..
Community relations
Community relations
Community relations
(laid
File
Community relations
Community relations
Community relations
Community relations
Statement ol work re community relations
plan and implementation for the
Northside Superfund site
Procurement request order form re
community relations plan and implemen-
tation support for Northside Landfill;
work assignment form; statement of work
Memo re representative Stratton request
for information on the Spokane aquifer/
letter re test results from Community
against pollution (2/6/84)/attached
general information
Type/Description
Fact sheet - Environmental investigations
at the Northside Landfill
Revised Community Relations
Plan, Northside Landfill
Northside landfill Fact Sheet
Fact Sheet - Northside landfill
Proposed Plan
4/10/87 2
6/19/87 6
2/6/84 4
Date # Pages
5/12/88 2p
9/88 19p
9/1/88 2p
02/28/89 6p
J. Schwarz
Francis Chapman, EPA
c
7
Glenn Grace, WDOE
Don Dubois, Joan Thomas
Author/Organization Addressee/Organization
EPA
EPA
EPA
EPA
-------
OOOOOI2h. Community relations Fact Sheet - Synopsis of Northside 05/02/89 3p EPA
Land)ill Responsiveness Summary
00000127. Community relations Northside Landfill Responsiveness Summary 05/89 I2p EPA
. Newspaper Clippings
OUOOOOI'l. Newspaper clippings
00000015. Newspaper clippings
Landfill lawsuit initiated
Toxic waste cleanup moving ahead;
But county, city balking on two sites
000000%. Newspaper clippings Garbage a nationwide problem
T)0000017. Npwspaper clippings Finding a home for garbage
OOOOOO'IO. Newspaper clippings County, city officials lean toward
'mass burn' system
00000050. Newspaper clippings Where will your garbage go?
00000051. Newspaper clippings City says plant won't burn dollars
OOOOOOW. Newspaper clippings Cities, linns plant's partners
0000005:!. Newspaper cl ippings
00000051. Newspaper clippings
Din." __..fi!e_
00000055. Newspaper clippings
State gets cash to probe 3 landfills
Northside pollution felt stabilized
Type/Descript ion
Underground pollution Irom fill not
spreading
8/18/78 1
11/18/81 I
3/17/85 I
3/17/85 2
V18/85 I
000000-1'). Newspaper clippings Plant expensive, but so is alternative 3/18/85 2
3/19/85 I
4/17/85 1
12/11/85 1
Date tt Pages
12/12/86 I
Unknown
Jeff Sher, Spokesman-
Review
Ken Sands, Spokesman-
Review
Ken Sands, Spokesman-
Review
Ken Sands, Spokesman-
Review
Ken Sands, Spokesman-
Review
3/18/85 1 The Spokesman-Review
3/19/85 • 2 Rick Bonino,, Spokesman-
Review
Ken Sands, Spokesman-
Review
The Post-Intelligencer
Jeff Sher, The Spokesman-
Review
Author/Organization
Rick Bonino, Spokesman-
UOOOOOSd. Newspaper clippings Municipalities sing requiem lor
12/15/85 I The Spokesman-Review
-------
landfills
OOOOUOb/. 1.al) reports and
data
HSU tests
5/25/77-
6/12/78
Unknown
00000058. l.ab reports and
data
0000005').
Lab reports and
dd I a
208 lab tests; Spokane Aquifer
Water Quality Study Chronological
Display
Extended monitoring data
8/21/78
2/4/79
Idaho Health and Welfare
Lab
EPA Lab
OOOOOObO.
Lab reports and
data
Water sample reports
11/16/83 1
W. E. Burkhardt. ABC
Laboratories, Inc.
Dept. of Public
Utilities. Refuse Uiv.
UOIIflOOu I.
00000062.
I cib reports and
data
Iah reports and
data
Water sample reports
Water sample reports, Lab No.
1615-8.1
11/16/8:1 I
11/17/83 2
W. E. Burkhardt, ABC
Laboratories, Inc.
W. E. Burkhardt. ABC
Laboratories, Inc.
Oept. of Public
Utilities, Refuse Div.
Dept. of Public
Utilities, Refuse Div.
00000063.
Inb reports and
data
Water sample report. Lab No.
1655-83.
11/21/83 1
W. E. Burkhardt, ABC
Laboratories. Inc.
Dept. of Public
Utilities, Refuse Div.
00000064.
I ab. reports and
. flat a
00(100016. I ab reports and
data
Water sample reports, chain of custody 12/16/83 15
records, field reports. Lab No.
1704-83
Water sample reports. Lab No. !704-8<. 12/16/83 3
W. E. Burkhardt. ABC
Laboratories, Inc.,
George Maddox & Assocs.
W. E. Burkhardt, ABC
Laboratories, Inc.
Dept. of Public
Utilities, Refuse Div.
Dennis Mine
Dept. of Public
Utilities, Refuse Div.
0000001.0.
Lab reports and
data
0000001.7. I ab reports and
(1.11.1
Water sample reports. Lab No. 1744-84,
1748-84
Iyfie/J)escriptiojL
Water sample reports. Lab No. 1781-84
1/9/84 3
1/16/84
_Dai£_ H Pages
1/20/84 2
W. E. Burkhardt, ABC
Laboratories, Inc.
Author/Organization
W. E. Burkhardt, ABC
Laboratories, Inc.
Dept. of Public
Utilities, Refuse Div.
Addressee/Organization
Dept. of Public
Utilities, Relus Div.
OOOIIOO(><). I ah reports and
rtnta
Memorandum regarding North and South
Landfill water samples; attachments of
3/8/84 20
Hale Arnold. Lab
Supervisor
John Swanson, Director
of Public Utilities
-------
water samples analysis and results
00000070.
00000071.
(10000072.
ouoooo/:<.
00000074.
(ah reports and
delta
lab reports and
data
I ah reports and
data
Lab reports and
data
tali reports and
data
Results of laboratory analyses of
South Landfill water samples
Northside Landfill residential well
samp!ing
6/20/84
8/84
Field report on residential well sampling. 8/15/84
chain of custody record, conductivity graphs
Hater sample report. Lab No. 2376-84.
8/20/84
Results of gas well monitoring Southside 6/21/84
Landfill, Nor tits ide Landfill chain ol records,
residential well sampling, water testing
Unknown
Unknown
38 Joanne Ellison
1 W. E. Burkhardt, ABC
Laboratories
20 Joanne Ellison, Richard
Schram, City ol Spokane,
Refuse Div.
City of Spokane,
Refuse Division
Oept. of Public
Utilities
00000075. Ldh reports and
data
00000117. lab Reports & Data
Memorandum re QA of organic samples Case
3184 lor Spokane Steel, Northside Landfill,
Southside Land!ill and Mica Landfill.
Attached organics analysis data sheets.
Northside Landfill Methane Gas Data
12/18/84 10
U.- HiscelIaneous Correspondence
00000076. Correspondence -Misc. LeLter regarding hazardous waste waiver
request, Northside Land! ill
00000118. Correspondence -Misc. Notilication to prioritize Northside site
OQC.W File Type/Description
OOUOOII') Correspondence -Misc. Request lor information on lOb order
5/17/88 3p
6/8/79 2
12/7/87 Ip
Date ft Pages
12/30/87 Ip
Andrew Hafferty, Jim Farr. John Osborn, EPA
Ecology & Environment
Rhys. A1 Sterling
Spokane County Health
District
Phil Williams
City of Spokane
Edward M. Pickett, Spokane Roger James, City
County Health District Utilities Director
Carol Rushin
EPA
Author/Organization
Marsha A. Beery .
WDOE
Peter Kmet
WDOE
Addressee/Organ i zat ion
Neil Thompson
EPA
CQ
-------
IB. MisieIIdneous Memoranda
000000/7. Memoranda
Memoranda regarding phone conversation
with tynn Guy about groundwater contami-
nation from Northside.
H/15/83
Rene Fuentes
00000078.
Memoranda
Memorandum regarding status report - Pine
Meadows/Lowell Avenue water service
2/16/84
C. D. Robinson, Jr., City
of Spokane
19. Lnluicement - Administrative Orders
00000120. Enforcement - Admin letter regarding calculation
Ortlprs of costs in Order on Consent
.1/11/88 Ip Neil E. Thompson
EPA
Phil Williams
City of Spokane
00000121. fiiilurcenient - Admin
* Orders
Order on Consent
:»/!5/88
EPA
City of Spokane
Doc*
00000122.
OOOUOI21.
,.£Ue
Enforcement - Admin
Orders
Enforcement - Admin
Type/Description
Change of information on
Consent Order
Comments on EPA's
Consent Order
Date tt Pages
3/16/88 1
4/12/88 2p
Author/Organization
Irving B. Reed
City of Spokane
Dave Kargbo
WDOE
Addressee/Organization
Neil Thompson
EPA
Neil Thompson
EPA
20. Notice Letters and Responses
00000081.
0000008!).
Notice tetters &
Responses
Nut ice tellers &
Responses
Notice letter to state re proposed 8/16/84
Superfund projects
teller of notification re potential liab- 9/30/85
ility for federal actions at North;ide
tandfill
Kathryn M. Davidson, EPA
Charles E. Findley, EPA
Ken Bock, WA
Planning &
Community Affairs Agency
Terry Novak,
City of Spokane
00000086.
000(1008?.
Notice tetters R
Responses
Notice tetters 6
Responses
teller of noli f i.cation re potential liab-- 1/10/86
ility on behalf of the State of WA
teller of notification re potential liab- 1/10/86
ility on behalf of the State of WA
Fred Gardner, WDOE
Fred Gardner, WDOE
Terry Novak,
City of Spokane
Dennis Hein,
Cily ol Spokane
tl. lied I MI
-------
00000124. Health Assessment Health Assessment for North Landfill 5/25/88 I5p ATSOR
sampling
LW:ct: 55081'
m
------- |