United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R05-91/180
September 1991
Superfund
Record of Decision:
National Presto Industries, Wl
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50272.101
REPORT DOCUMENTATION 11. REPORT NO. I ~ 3. Rec:lpient'8 Acceselon No.
PAGE EPA/ROD/R05-91/180
.. 1118 8l1li ~ 5. Report Date
SUPERFUND RECORD OF DECISION 09/30/91
National Presto Industries, WI 6.
Second Remedial Action
7. AuIhor(81 8. Perfonnlng Org8nIza1Ion Rept. No.
8. P8rt0rmlng OrgalnlDlon Name and Add-. 10. ProjecllTuklWark Unit No.
11. ConIr8d(CI or Gnnt(G) No.
(C)
(GI
1~ ~ OrllanlZ8llon Name and Addr888 13. Type of Report & PerIod Co--..d
U.S. Environmental Protection Agency 800/000
401 M Street, S.W.
washington, D.C. 20460 14.
15. Supplementary No...
18. Ab8Ir8ct (Umlt: 200 -rdal
The 325-acre National. Presto Industries site is a former munitions and metal-working
facility in Eau Claire, Chippewa County, wisconsin, adjacent to the town of Hallie.
Surrounding land use is light residential and commercial, and the Chippewa River is
located approximately 2 miles north and west of the site. Lake Hallie is located
approximately 1 mile north of the site. The site overlies a buried pre-glacial valley
that serves as a primary source of drinking water. From 1942 until 1945, the site was
a government-owned, contractor-operated producer of gunpowder, small arms, and radar
tubes. The site was owned by National Presto Industries (NPI) since 1948. Initially
NPI manufactured cookware and consumer products, and generated waste streams
consisting of metals, oils, grease, and spent solvents during operations. Also,
beginning in 1951, artillery shell fuses and aircraft parts were produced by NPI under
military contracts. Metal projectiles production began in 1954 under separate
contracts Early waste-handling practices included the use of dry wells and seepage
pits with overflow from the pits discharged to a former sand and gravel pit via
gravity flow. Wastes also were discharged directly to the sand and gravel pit.
During the 1960's, 3 additional lagoons were constructed as percolation ponds with the
(See Attached Page)
17. Doc:unent An8Iyaia .. De8cripto..
Record of Decision - National Presto Industries, WI
Second Remedial Action
Contaminated Medium: gw
Key Contaminants: VOCs (PCE, TCA, TCE)
b. IcI8n1Ifter8IQpEnded T-
Co COSATI fieIdIGr~
18. AYlillabIIty SI8tement 19. SecI8'Ity a... (ThI8 Report) 21. No. of Pages
None 54
20. Seamy a... (Thia Pagel n Price
Nnn'"
272 (4-77)
(See AN&-Z3I.181
See IMlrUClioM on Re"",..
(Formetty NT1S-351
Deparlment of Conwnerce
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EPA/ROD/ROS-9l/l80
National Presto Industries, WI
Second Remedial Action
Abstract (Continued)
former sand and gravel pit serving as a settling pond. A major waste stream generated
from the defense-related activities was a spent forge compound, composed of mineral
oil, graphite, VOCs, and asphalt, which accounts for much of the sludge in the bottom
of one of the settling ponds. From 1966 to 1969, the spent forge compound also was
landfilled onsite. Subsequently, the spent forge compound was recycled as part of the
manufacturing process. Based on their investigations, EPA required NPI to provide
bottled water to an area in Hallie where private wells were contaminated or threatened
by contamination from confirmed onsite sources. A 1990 Record of Decision (ROD)
provided a permanent alternate water supply in the form of hookups of affected
residents and businesses to municipal distribution systems. Further investigations by
EPA helped determine the presence of four major contaminants migrating from the NPI
site. This ROD addresses management of migration as an interim remedy. A subsequent
ROD will address final remedies for both onsite source control and ground water. The
primary contaminants of concern affecting the ground water are VOCs including PCE, TCA,
and TCE.
The selected remedial action for this interim remedy includes onsite pumping and
treatment of ground water using two cascade aeration units; discharging the treated
water to onsite storm s~wers for transport to surface water; conducting further studies
to determine the need for pretreatment of ground water; installing a dedicated pipe
system for surface water discharge if the storm sewer system cannot be utilized; and
conducting long-term ground water monitoring. The estimated present worth cost for
this remedial action is $1,290,000, which includes an annual O&M cost of $163,000 for
years 0-1 and $104,000 for years 2-30.
PERFORMANCE STANDARDS OR GOALS: Treated water must meet the requirements of CWA
Ambient Water Quality Criteria and State standards for discharge to surface water.
Chemical-specific goals are not provided, but will be developed as part of subsequent
investigations.
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RECORD OF DECISION
SELECTED INTERIM ACTION ALTERNATIVE
Site Name and Location
National Presto Industries, Inc.
Eau Claire, Wisconsin
statement o~ Basis and purpose
This decision document presents the selected interim action for on-
site contaminated groundwater at the National Presto Industries,
Inc. (NPI) site in Eau Claire, wisconsin. The selected interim
action was chosen in accordance wi th the Comprehensi ve
Environmental Response, compensation, and Liability Act of 1980, as
amended by the superfund Amendments and Reauthorization Act of 1986
(CERCLA), and to the extent practicable, the National Contingency
Plan (NCP). This decision is based on the administrative record
for this site. The attached index identifies the items that
comprise the administrative record upon which the selection of the
interim action is based.
The State of Wisconsin concurs with the select~d interim action.
The letter of concurrence is attached to this Record of Decision
(ROD).
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 a current or potential threat to human
health, welfare, or the environment~ .
~:
Description of the selected Remedy
This interim action is limited to an operable unit that addresses
contaminated groundwater through plume containment by means of
groundwater extraction and treatment. Under this interim action,
contaminated groundwater will be removed at on~site source areas,
treated and discharged to the Chippewa River.
The specific components of the remedial action include:
*
Installation and operation of groundwater extraction
wells at the Melby Road Disposal Area and the
southwestern portion of the site downgradient of Lagoon
No.1 and Ditch ~o. 3;
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*
Treatment of extracted groundwater by cascade aeration
comprising two 9-foot concrete step structures
constructed on site. One unit will treat groundwater
extracted at the Melby Road Disposal Area and the second
unit will treat groundwater extracted at the southwestern
portion of the Site;
Discharge of treated groundwater to the City of Eau
. Claire storm sewer system for transport to the Chippewa
River;
*
*
Long-term monitoring to measure progress and performance
of the groundwater extraction system, verify completeness
of contaminant plume capture, determine the need for
addi tional treatment of extracted groundwater and monitor
compliance with WPDES permit requirements; and
*
provision for installation of dedicated pipe from the NPI
Site to Lake Hallie or the Chippewa River should future
use of the Eau Claire storm sewer system be precluded or
sufficiently restrictive thus jeopardizing the ability of
this interim action to prevent off-site movement of
contaminated groundwater~
statutory Determinations
This interim action is protective of human health and the
environment, complies with Federal and State applicable or relevant
and appropriate requirements for this limited-scope action, and is
cost-effective. This action is interim and is not intended to
utilize permanent solutions and alternative treatment technologies
to the maximum extent practicable for this operable unit. Because
this action does not constitute the final remedy for the facility,
the statutory preference for remedies that employ treatment that
reduces toxicity, mobility, or volume as a principal element will
be addressed by the final response action. Subsequent actions are
planned to address fully the threats posed by the conditions at the
facility. Because this remedy wil~result in hazardous substances
remaining on site above health-based levels, a review will be
conducted to ensure that the remedy continues to provide adequate
protection of human health and the environment within five years
after commencement of the remedial action. Because this is an
interim action ROD, review of this facility and of this remedy will
be continuing as u.S. EPA continues to develop final remedial
alternatives for the facility.
~~/
Da ~e I
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RECORD OF DECXSXON
INTERIM ACTION ALTERNATIVE SELECTION
NATIONAL PRESTO INDUSTRIES, INC
EAU CLAIRE, WISCONSIN
Prepare
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I.
II.
III.
IV.
V.
VI.
VII.
VIII.
IX.
X.
XI.
Table of Contents
Site Name and
Loca tion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Site History and Enforcement Activities...............2
Community Relations Activities........................5
Role and Scope of This Interim Action.................7
Summary of Site
Characteristics.......................S
Summary of Site
Risks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Description of Alternatives..........................13
Summary of comparative Analysis of Alternatives......20
A. Threshold criteria............................... .21
1. Overall Protection of Human Health and
the Environment................................ 22
2. . Compliance with ARARs.......................... 22
B. Primary Balancing Criteria........................24
1. Long-Term Effectiveness and Permanence... '. . . . . .24
2. Reduction in Toxicity, Mobility and Volume.....24
3. Short-Term Effectiveness.......................24
4. Implementability............................... 25
5. Cost........................................... 26
C. Modifying Criteria................. ~. . . . . . . . . . . . . .27
1 . sta te Acceptance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2'"
2. Community Acceptance.... . . . . . . . . . . . . . . . . . . . . . . . 27
The Selected RemedY..................................27
Statutory Determinations
A. Protection of Human Health and the Environment....30
B. compliance with' ARARs............................ .30
1. Chemical Specific ARARs....................~...30
2. Location Specific ARARs........................3l
3. Action Specific ARARs..........................31
c. Cost Effectiveness................................33
D. Utilization of Permanent Solutions and Alternate
Treatment Technologies to the Maximum Extent
Practicable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
E. Preference for Treatment as a Principal Element...33
Responsiveness SummarY...............................33
A. Introduction...................................... 33
B. Background on Community Involvement...............35
C. Summary of Comments Received During th~ Public
Comment Period.................................... 35
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SUMMARY OF INTERIH ACTION ALTERNATIVE SELECTION
NATIONAL PRESTO INDUSTRIES, INC.
EAU CLAIRE, WISCONSIN
I.
SITE NAME. LOCATION AND DESCRIPTION
The National Presto Industries, Inc. Superfund Site (NPI site or
site) is located at 3925 North Hastings Way in Eau Claire,
Wisconsin (Figure 1). The Site occupies approximately 325 acres in
the southern one-half of sections 34 and 35, Township 28 North,
Range 9 West, Chippewa County, Wisconsin and the northwestern
quarter of section 2, Township 27 North, Range 9 West, Eau Claire
County and comprises the property owned by NPI.
The immediate vicinity of the site is characterized by light
residential and commercial development. The unincorporated Town of
Hallie is located north and east of the site; however, annexations
of individual parcels of land north of the site into the City of
Eau Claire have created an irregular Town-City boundary north of
the site.
The Site is relatively flat and abuts a sandstone ridge to the
south that is approximately 200 feet higher than the Site. The
areas north and west of the Site are also. relatively level
generally sloping gradually toward the Chippewa River which is
located approximately two miles north and west of the Site. Lake
Hallie lies about one mile north of the site and is an impounded
remnant of a former channel of the Chippewa River.
Extending southward from Lake Hallie through the northwestern
portion of the site and westerly to the Chippewa River is a buried
pre-glacial valley that serves as a primary drinking water aquifer
in the Eau Claire area. Many private drinking water wells
immediately north of the Site ari: finished in sand and gravel
deposits within the buried valley. The Eau Claire municipal well
field draws from the same buried valley deposits approximately 2
. miles west of the Site and serves approximately 60,000 people.
Notable surface features at the site include the main building, a
number of smaller buildings, and Lagoons 1, 2,- 3 and 4. Lagoon 1
is a former sand and gravel pit with an irregular shape and is
approximately 1.5 acres in size. Lagoons 2, 3 and 4 are
approximately 14, 3.1 and 3.4 acres in size, respectively.
A six-foot chain link fence surrounds the western one-third of the
Site, including the main building and Lagoon 1. Access to this
area is restricted and entry is monitored by security guards.
Access to the remainder ot the Site is not restricted, although
much of the Site is surrounded by a four-foot wire fence.
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i
~
National Presto Site
Eau Claire, .Wisconsin
Figure 1
o
Hagen Road
-0-
I
Chippewa ~
Early Dr.
~O
EAU CLAIRE
COUNTY AIRPORT
Sundet
Road
~
/--,
I ,
/ I
I I .
I I
I I
1 I
\ EAU CLAIRE
\ MUNICIPAL
\ WELL FIELD
\. ,
\ \
\ \
\ \
\ \
\ \
\ \
Melby
..,.
.
-
Hallie lane
cD
~
"-
"-
to
.....
en
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2
II.
SITE HISTORY AND ENFORCEMENT ACTIVITIES
The site was originally owned by the United states Government (War
Assets Administration) and operated by government contractors
between 1942 and 1945. Two contractors known to have operated at
the site were u.s. Rubber Company (now Uniroyal, Inc.) and Western
Electric (now a part of AT&T Technologies, Inc.). U.S. Rubber
operated a gunpowder and small arms loading plant at the Site
during the period 1942-1943 under contract with the Army Corps of
Engineers. The operation consisted of facilities for powder and
chemical storage and mixing, primer manufacturing and storage, and
firing test ranges. Materials used in the production processes
included lacquers and solvents. During this period there were
several sewer and drainage systems for waste disposal consisting of
storm water drainage ditches, a sanitary sewer and a dry well or
seepage pit system. The seepage pits were generally 18 to 20 feet
in diameter and 8 to 10 feet deep. They were reinforced with wood
or dry-laid concrete block walls. The pits were designed to accept
wastewater which then "seeped" into the surrounding soils. The
volume and content of wastewater discharges by U.s. RUbber is not
known.
In 1944, the site was leased to Western Electric for the production
of radar tubes for navy night fighters which continued until 1945.
Production processes reportedly included cutting, washing, plating
and painting, some of which utilized solvents. There are no
records available on waste handling and disposal during Western
Electric's tenure at the site.
NPI purchased the Site from the federal government in September
1948, and between 1948 and 1954 manufactured household appliances
(pressure cookers and canners, coffee makers, steam irons and deep
fryers) and outboard motors. Beginning in 1951, the Site was also
used for defense-related activities such as the manufacture of
fuses for the Department of the Army (DOA) and production of
military aircraft parts. Producti~ processes during this period
included metal fabrication, casting, washing, plating, stamping,
painting, grinding and other machining operations. Although
specific information on waste types and volumes is lacking, waste
streams would typically include metals, oil and grease, spent
solvents and degreasing agents, plating wastes and other
miscellaneous industrial wastes.
In 1954, NPI dedicated the Site entirely to defense-related
manufacturing, primarily the production of metal parts for 105MM
projectiles and 8-inch shells, under contracts with the Department
of the Army. Between 1959 and 1965, there was little or no active
production at the Site. In 1966, the site was actiVated and multi-
shift production continued until the mid-1970s. Except for a six-
month research and development contract in late-1983 and early-
1984, production of the 8-inch shells ceased in 1971. Production
of the 105MM projectiles ceased in 1980.
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3
Since October 1, 1981, National Defense Corporation (NDC),a wholly
owned subsidiary of NPI, has entered into annual standby contracts
with the DOA to maintain the site in a high state of readiness.
These contracts provide for the storage and maintenance of the
government-owned machinery and equipment which is in place and
fully operational. The Site is the DOA' s mobilization base
producer for the 105MM and eight-inch projectiles.
During government ownership of the Site and the early years of
NPI's operation, seven seepage pits, or dry wells were used for
disposal of waste liquids and storm water runoff. These dry wells
were pits 18 to 20 feet in diameter with a depth of 8 to 10 feet.
Tops of the dry wells were located three to four feet below the
ground surface. Four dry wells- were in existence when NPI
purchased the Site. After the Site was purchased, NPI constructed
three additional dry wells.
The dry wells were equipped with overflow pipes to the Eau Claire
sanitary sewer system. Overflow from several of the dry wells was
also discharged to on-site drainage ditches (Ditch No.2 and 3).
Some wastes were discharged to the sanitary sewer directly or
through the overflow pipes. In 1952, following serious overflow
problems in the Eau Claire sewer system, NPI began pumping wastes
from the dry wells to a former sand an~ gravel pit located south of
the main plant. This is the present location of Lagoon 1-
Historical information suggests that the former sand and gravel pit
was used as a disposal area prior to 1948, i~e. prior to NPI's
ownership of the site. Drainage from Ditch No.2 was also directed
into the sand and gravel pit.
By 1966, when manufacturing operations were reactivated in response
to the Vietnam War, the efficiency~f Lagoon 1 was greatly reduced
by the accumulation of sludges in the lagoon bottom. As a result,
Lagoons 2, 3 and 4 were constructed during 1966-1967 for use as
percolation ponds. Under this waste disposal system, plant
wastewater and manufacturing cooling water were discharged into
Lagoon 1 which served as a settlin; pond. As solids settled and
oils floated to the top, the effluent was pumped to Lagoon 2.
Depending on capacity requirements, water from Lagoon 2 was
discharged to Lagoons 3 and 4 via gravity flow. There were periods
during the 1970s when wastewater from Lagoons 2 and 3 was
discharged directly to the Eau Claire Sanitary sewer system.
During peak productionin the late 1960s, 2.5 to"3.0 million gallons
per day of groundwater was withdrawn from on-site production wells
and a similar volume of wastewater was generated and discharged to
the lagoon system.
A major waste stream generated from defense-related activities was
a spent forge compound. In its pure form, forge compound
comprised approximately equal parts of graphite, asphalt and
mineral oil. It was used as a lubricant in the production of 105MM
projectiles. Spent forge compound contains metals and VOCs,
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4
primarily 1,1, I-trichloroethane, . which was a solvent used for
cleaning the forge compound from the manufacturing equipment.
Spent forge compound was in the cooling water discharged to Lagoon
1 and accounts for the large volume of sludge present in the lagoon
bottom. Additionally, between 1966 or 1967 and 1969, spent forge
compound was landfilled on the Site in an area northeast of the
main plant that has been identified as the Melby Road Disposal
Area. Beginning in 1969, NPI developed a reclamation process
whereby spent forge compound could be reclaimed and recycled in the
manufacturing process.
In April 1986, following a complaint to the WDNR, an additional
disposal area was discovered near the east property line of the
site. This has been identified as the East Disposal Area. An
investigation by WDNR and NPI revealed a number of exposed drums
containing varying amounts of unknown wastes. NPI removed the
drums from the area, transported them to a secure unused loading
dock at the main plant and sampled them to characterize drum
contents. These wastes will be remediated in a manner consistent
with waste materials in on-site source areas as part of the final
cleanup plan for the Facility. The Facility comprises the full
extent of contamination attributable to past waste disposal
practices at the NPI site and includes, but is not limited to, the
NPI site and Plumes 2 and 3, as shown on Figure 5.
Figure 2 is a site map and illustrates the waste management and
disposal areas used during the course of site operations between
the early 1940s and 1980.
On December 2, 1985, U.S. EPA issued a general notice letter to NPI
informing the company of its potential liability with respect to
response actions, past or plannecr, taken at the Facility, and
asking them to undertake a Remedial Investig~tion and Feasibility
study (RIfFS). Negotiations concluded in May 1986, when NPI
entered into an agreement with u.s. EPA and the WDNR to conduct the
RIfFS at the Facility. An Administrative Order by Consent became
effective on July 8, 1986. ~
Based on analytical data generated from monitoring well and private
well sampling during the RI and recommendations from the Wisconsin
Division of Health and the Agency for Toxic Substances and Disease
Registry (ATSDR), u.S. EPA issued NPI a Unilateral Order on April
25, 1989 pursuant to the March 31, 1988 Record of Decision for the
Eau Claire Municipal Well Field Superfund Site. The order became
effective on May 5, 1989. The order required NPI to provide
bottled water to a portion of the Town of Hallie and City of Eau
Claire defined as the affected area (Fiqure 3). The affected area
is an area in which private wells are contaminated~r threatened by
contamination from confirmed on-site sources at NPI, The affected
area comprises approximately 350 acres (excluding the property
owned by NPI) and has approximately 174 residences with a total
estimated population of 425. There are also about 40 commercial
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Melby Road Disposal Area
East Disposal Area
~
\ \ Melby Roa~ //
National Presto
Main Plant.
JL
.Lagoon #2
Lagoon #1
LEGEND
~+"}::':1 Waste Disposal Areas
ED Dry Well (Approximate Locations)
~:
Figure 2
Site Map
National Presto Industries
Eau Claire, Wisconsin.
1
I
Not to Scale
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Figure 3
Final Affected Area
National Presto Site
Hagen ~
Melby Road
~ I~
b::tt:::1 Affected Area
. Eau Claire Annexations
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5
businesses located in the affected area. The order also required
NPI to: (1) undertake a Phased Feasibility study (PFS) to identify
and evaluate remedial alternatives for a permanent alternate and
safe drinking water supply for the affected areai and (2) conduct
additional sampling to fully define the extent of private well
contamination.
Four additional potentially responsible parties (PRPs) have been
identified for the Facility. They are NDCi AT&T Technologies,
Inc.; Uniroyal, Inc.; and the United states Department of the Army.
General notice letters relative to the permanent alternate drinking
water supply for the affected area were issued to each of the PRPs
on July 24, 1990.
On August 1, 1990, a Record of Decision (ROD) was issued by U.s.
EPA presenting the selected remedial action for a permanent
replacement drinking water supply for the affected area. Under the
terms of the ROD, the City of Eau Claire is to extend its municipal
drinking water to residences and businesses in the affected area
that have annexed to the Ci ty . The remaining portions of the
affected area will be serviced by the Hallie Sanitary District
No.1 (Sanitary District).
Remedial design was initiated in September 1990 and formally
approved by U.S. EPA on February 27, 1991. On March 8, 1991, U.S.
EPA issued an Administrative Unilateral Order to NPI and NDC
directing the companies to provide alternate drinking water supply
systems for the affected area in the City of Eau Claire and Town of
Hallie in accordance with the approved remedial design. NPI and
NDC are currently providing funds to the sanitary District and the
City of Eau Claire for construction of the drinking water systems.
The sanitary District began construction in April 1991, and the
City of Eau Claire initiated construction in July 1991 for their
respective components of the selected remedy. Construction is
ongoing and the drinking water systems are expected to be completed
and operational by the end of 1991.
~
General notice letters relative to this interim action for on-site
contaminated groundwater were issued to each of the PRPs on
September 19, 1991.
III.
COMMUNITY RELATIONS ACTIVITIES
During the RI/FS process, many community relations activities have
been performed by U.S. EPA with considerable support provided by
WDNR. In October 1987, U.S. EPA established information
repositories at the Hallie Town Hall and the Chippewa Falls Public
Library. In June 1986, U.S. EPA issued a press release announcing
the finalization of the RI/FS Consent Order signed by U.S. EPA,
WDNR and NPIi and held a 30-day public comment period on the
Consent Order.
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6
Q
In October 1987, u.s. EPA conducted community interviews with local
officials and interested residents to learn of local concerns and
issues for inclusion in the Agency's Community Relations Plan. An
RI "kickoff" meeting was held (approximately 75 people attended)
with .press releases and advertisements issued to announce the
event. A fact sheet was also prepared and distributed in
conjunction with the meeting.
The Community Relations Plan was
advertisement ran in the Chippewa
Claire Leader-Telegram announcing
Assistance Grants.
finalized in June 1988. An
Falls Herald-Telegram and Eau
the availability of Technical
A public meeting (approximately 90 people attended) was held in
April 1989 to provide an update of the RI, and include a discussion
by the wisconsin Division of Health on private well sampling
results and potential health issues. A fact sheet summarized
private well sampling results, the proposed distribution of bottled
water to affected residents and a proposed study to evaluate
alternatives for a permanent and safe drinking water supply for the
affected area.' The meeting was advertised in the two local
newspapers and press releases were sent to all local. media.
u.s. EPA prepared and distributed letters in June 1989 to
businesses and residences whose wells were sampled in April 1989.
Those who lived in the affected area were encouraged to participate
in the bottled water program which was outlined.in the unilateral
order issued to NPI in April 1989.
U.S. EPA and WDNR held an informal availability session
(approximately 20 people attended) in August 1989 to update
residents on the RIfFS and the PFS.- The meeting was advertised in
both local newspapers and press releases were sent to all local
media.
In December 1989, a press release wa~ issued announcing the release
of the PFS report and the p~posed Plan which evaluated
alternatives for the replacement of contaminated drinking water
supplies in the affected area. Advertisements were placed in both
newspapers announcing the beginning of the public comment period
and the availability of the PFS and Proposed Plan, summarizing
remedial alternatives discussed in detail in the PFS, and
announcing a public meeting to answer questions and accept public
comments on the Proposed Plan. A fact sheet summarizing the PFS
report, remedial alternatives and u.s. EPA's preferred alternative
was also distr ibuted in December. An administrati ve record,
containing site-related documents relevant to the Proposed Plan,
the RIfFS and this ROD, was established at the" Chippewa Falls
Public Library in conjunction with the information repository. At
the request of Hallie Town Board members and Hallie residents, an
administrative record was also established at the Hallie Town Hall.
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7
The public meeting was held on January 18, 1990 and attended by
approximately 130 people. u.s. EPA and WDNR explained the PFS and
Proposed Plan, answered questions, and accepted public comments on
the remedial alternatives discussed in the PFS and Proposed Plan.
The public comment period originally was scheduled to run for 45
days, January 4 through February 19, 1990; however, at the request
of many residents, the City of Eau Claire and NPI, it was extended..
until March 5, 1990. This 15-day extension was advertised in both
local newspapers. The community relations coordinator telephoned
NPI, local officials and reporters from all local media to inform
them of the extension. A transcript of the public meeting was
placed in the information repositories.
In August 1991, a press release was issued announcing the
availability of the PFS and Proposed Plan addressing an interim
remedial action for on-site contaminated groundwater. The public
comment period began on August 23, 1991. Advertisements were
placed in both local newspapers announcing the availability of the
PFS and Proposed Plan, summarizing the remedial alternatives
considered for this interim action, and announcing a public
meeting. A fact sheet summarizing the PFS report, Proposed Plan
and U.S. EPA's and WDNR's recommended alternative was distributed
in August 1991 to interested parties on u.s. EPA's mailing list.
An administrative record update, containing Facility-related
documents relevant to the Proposed Plan, the RIfFS and this ROD was
forwarded to the information repositories.
(>
The public meeting was held on September 12, 1991 at the Hallie
Town Hall and attended by approximately 40 people and members of
the local media. u.S. EPA and WDNR explained the PFS and Proposed
Plan, updated the progress of the RIfFS, answered questions, and
accepted public comments on the remedial alternatives discussed in
the PFS and Proposed Plan. The public comment period ended on
September 23,1991. A transcript of the public meeting is included
in the administrative record.
Interest in the Facility has been~igh since 1985 on the part of
Hallie residents, the media, City of Eau Claire and Town of Hallie
officials and other elected officials. u.s. EPA, WDNR and
Wisconsin Division of Health representatives have had numerous
personal visits and telephone conversations with members of the
media, residents, local officials and NPI since the beginning of
the RIfFS. The mai.ling list and information h'ave been updated to
ensure that the community receives accurate information in a timely
fashion.
IV.
ROLE AND SCOPE OF THIS INTERIM ACTION
This interim action is limited to plume containment at the Melby
Road Disposal Area and the southwestern portion of the Site
downgradient of Lagoon No.. 1 and Ditch No.3. Under this interim
. I
-------
8
action, groundwater will be removed at these source areas, treated
to remove VOCs and discharged to the Chippewa River.
This interim action will prevent the off-site movement of
contaminant plumes from these on-site source areas and prevent
further environmental degradation. The final cleanup plan will
address off-site groundwater and on-site source areas in a manner
that protects the environment and reduces health risks associated
with contamination at the Facility. Cleanup alternatives are
currently being developed and analyzed for on-site sources of
contamination that include Lagoon 1, Ditch No.3, Melby Road
Disposal Area, East Disposal Area and several of the dry wells.
Data from the recent and extensiv~ groundwater sampling also is
being evaluated to determine the appropriate remedial action(s) for
off-site groundwater.
- .
u.s. EPA anticipates that this interim action will be consistent
with planned future actions, i.e. the final phase of cleanup at the
Facili ty . Preventing groundwater -degradation by means of plume
containment results in significant risk reduction in the aquifer
downgradient of on-site source areas. Because of the complexity of
the Facility (multiple source areas and groundwater contamination
plumes), u.s. EPA believes this interim action will expedite the
completion of total cleanup at the Facility. Data gathered during
implementation of this interim action will be useful in the
selection of any final action at the Facility.
v.
SUMMARY OF SITE CHARACTERISTICS
The RI at the Facility has involved numerous sampling and
investigative activities since late-1986. Work conducted during
the RI has included sampling and analysis of groundwater, soils,
soil vapor and waste materials, and geologic and hydrogeologic
studies.
Approximately 100 groundwater monitoring wells have been installed
on and off site between 1986 and 1991 as part of the RI to
determine the nature and extent of contamination at the Facility.
Moni toring wells have been installed at the water table, at
intermediate depths and at the bottom of the sand and gravel
aquifer, and in the underlying bedrock aquifer. Water table well
screens also extend into the capillary fringe. NPI has sampled
monitoring wells installed by u.s. EPA from 19~5-87 for the RIfFS
at the Eau Claire Municipal Well Field (ECMWF) Superfund site and
wells 1nstalled by WDNR in 1985. The most recent sampling event
concluded in April 1991 and encompassed more than 50 monitoring
wells, including 19 wells which were installed west of the NPI site
in December 1990 and January 1991 to further define Plume 2, as
described in "3)" below and illustrated on Figure 5. Analysis of
groundwater samples has shown the presence of at least three
contaminant plumes extending significant distances from the NPI
Site. The primary contaminants in the plumes are the VOCs 1,1,1-
-------
9
trichloroethane (TCA) , trichloroethene (TCE) , 1,1-dichloroethane
(l,l-DCA), 1,1-dicloroethene (l,l-DCE), tetrachloroethene(PCE) and
1,2-dichloroethene (1,2-DCE). The data has not shown the presence
of concentrated low density contaminants or dense non-aqueous phase
liquids (DNAPLs).
Data generated during the RI establish the following findings
which provide the rationale and documentation for proceeding with
this interim action:
4)
1)
On site, groundwater generally flows from the southeast
to the northwest; however, once groundwater moves off
site, it is influenced by_the location and orientation of
a preglacial buried valley containing sand and gravel
deposits to depths of 150 feet. The buried valley system
extends from Lake Hallie, which is located approximately
one mile north of the Site, to the southwest through the
northwest portion of the Site where it turns west and
ext~nds to the Eau Claire municipal well field and the
Chippewa River, approximately 2.5 miles west of the Site.
Groundwater flow is complicated by a groundwater divide
that extends southeast to northwest across the NPI Site
and the buried valley. Groundwater north and east of the
divide enters the buried valley and flows north to Lake
Hallie. Groundwater south and west of the divide enters
the buried valley and flows westward to the Eau Claire
municipal well field and the Chippewa River. Figure 4
illustrates the approximate locations of the buried
valley and groundwater divide.
2)
3)
Plume 2 is located south and west of the groundwater
divide. It originates at the NPI Site in the vicinity of
Lagoon 1 and Ditch NO.3, and extends westerly through an
industrial park (located approximately 1 mile west of the
Site) and toward the EC~. Plume 2 is characterized by
the occurrence of TCE and TCA. Concentrations for each
of these contaminants are highest in monitoring wells
located on site or immediately downgradient of the Site.
Figure 5 shows the approximate boundaries of Plume 2.
(Fieldwork is continuing west of the NPI Site to fully
define the extent of contamination attributable to
releases at the NPI Site).
TCE is present in Plume 2 at levels above the federal
Maximum contaminant Level (MCL) of 5 parts per billion
(ppb) and the Wisconsin Enforcement Standard (ES), also
5 ppb. TCE ranges in concentration from 'non detect to 49
ppb, with the maximum concentration observed in
monitoring well MW-34A which is located on site and
immediately downgradient of Lagoon 1. Levels of TCA in
Plume 2 range from non detect to 180 ppb, which was
-------
"
\"",
, ~,
~
CAVa....-
aurrr MlPatr
"......._~-- _.n....
-.. ..-
111
!iK497-4l . ,-
- - --- .- -- -. .. - .- -- --
- --
etJer O:i5ociult:s (;onsulting englneer:l. I' c.
1-
.------ "--.....--
I
-0-
I
FIGURE 4
~ [- r L~_L.__u u
>- /L~~_u u- ---_.~-
u '.
J_--
L...cJ~
-,-,
-,
'\.
\
\"
'''''''500'
LEGEND
LU...1 Approx. £dg" 01
8urit1d VoIlt1Y
-- Approx, Groundwottlr
Basin Boundary
BURIEI.LYALL~LMAe
NA TIONAL PRESTO INDUSTRIES, INC,
£ AU ClAIR£. WISCONSIN
-------
10
observed in monitoring well RW-15 that was sampled
during the ECMWF RI. The MCL and Wisconsin ES for TCA is
200 ppb.
5)
Plume 3 originates at the Melby Road Disposal Area and
extends generally west-northwest where, under the
influence of the groundwater divide and buried valley, it
turns north-northeast toward Lake Hallie. Plume 3 is
characterized by PCE, TCA, 1,1-DCA and 1,1-DCE near the
source and TCA and 1,1-DCA at monitoring points further
downgradient. Figure 5 shows the approximate boundaries
of Plume 3.
6)
TCA is present in Plume ~above the MCL and Wisconsin ES
with a maximum observed concentration of 510 ppb. The
maximum observed concentration for PCE is 12 ppb. The
MCL for PCE is 5 ppb and the Wisconsin ES is 1 ppb. The
maximum observed concentration for 1,1-DCA and 1,1-DCE
are 210 ppb and 5.6 ppb, respectively. There is
currently no MCL for 1,1-DCA; however, the Wisconsin ES
is 850 ppb. The MCL and Wisconsin ES for 1,1-DCE is 7
ppb. Concentrations of each of the above contaminants
are highest in on-site monitoring wells at the source
area and generally decline in value with increasing
distance from the source.
Figure 6 shows the locations of U.s. EPA, WDNR 'and NPI monitoring
wells sampled at and near the NPI Site. Data from these wells was
used in evaluating alternatives for this interim action.
Groundwater samples collected during the early phases of the RI in
1987-88 were analyzed for the entire list of priority pollutant
contaminants, including metals, VOCs and semi-volatile organic
compounds (SVOCs). The data did not indicate the presence of
identifiable SVOCs nor widespread elevated metals in groundwater,
so the analytical parameter list for future samples was reduced to
VOCs. For purposes of evaluatinq~lternatives for this interim
action, the recent groundwater sampling included metals analysis
for monitoring wells at the source areas and substantiates the
findings of the earlier data. Both sets of data indicate~levated
concentrations for cadmium, lead and nickel in isolated on-site
monitoring wells. .
Tables 1 and 2 present VOC data for on-site and off-site monitoring
wells, respectively, for groundwater samples collected by NPI
during the period 1987-91. Metals data for the same series of
moni tor ing wells is presented in Tables 3 and 4. U. S. EPA
collected split samples for selected monitoring wells during the
sampling conducted by NPI in April 1991, and those results are
presented in Table 5.
-'
-------
"AU CIMIF ,
CDUlrY -
~.tt'O
FIGURE 5
UME MAP
PL a INDUSTRIES, INC
NA nONALE~R;~~E, IMSCONSIN
-0-
I
,
,
Scale: 1 ",...1500'
FINGERPRINT VOCs
~
pLUME No. TCA, TCE, 1,1 DCE
2 TCA. DCE
J TCE
4 TCE
5
-------
o
ItW- 14 1(11)
UW-J6A.8
S
MW-/JA.8
S
UW-/2A.8
S
Lagoon No.2
----I
MS49704C
UW-9A.8
S
s
MW-7
MELBY ROAD SITE S
MW-I6A.8
S
S
MW-I9
ads, anoclalss consulting 8"II'n88's. p.c.
ttW- fl. liP
o
I
EAST DISPOSAL AREA
UW-18
S
LJ
~
S
/JW-24A.8
MW-/
S
1-
MW-25
S
UW-17A(Ory).B.C S
--~
LEGEND:
FIGURE 6
r!r
~
o
DNR Monitoring Well
(WW Prefix)
NPI Monitoring Well
(MW Prefix)
S
ED
Produclion Well
(W Prefix)
USEPA Monitoring Well
(RW Prefix)
.
o
I
-.-
700'
I
. ,
NA TIONAL PRESTO INDUSTf~IES. INC.
[AU CLAIRE. WISCONSIN
_._----~----._-
-------
TABLE 1
SUMMARY OF VOCS IN GROUNDWATER
ON SITE MONITORING WELLS
ALL CONCENTRATIONS REPORTED IN UG/L (parts per
billion)
WELL
NUM8ER
DATE
SAMPLED
TCE
PCE
TCA
. 1, 1-DCA
1,1-DCE
1,2-DCE
MW-4A 1/88 - - - - - -
10/88 - - - - - -
5/90 - - 0.2.1 - - -
4/91 - - - - - -
MW-48 6/90 0.7 0.2.1 24.0 7.0 0.2.1 -
4/91 2.08.1 0.5 34.0 9.0 - -
MW-5A 1/88 0.8 6.2 300D 120D 3.1 4.0
10/88 - 9.6 4008 2198 5.6 8.3
5/90 1.0 10.0 510D 180D 5.0 6.0
4/91 1.08.1 9.0 460D 220D 3.0 3.0
MW-58 1/88 - - 16.0 0.6 - -
10/88 - 0.4 19.0 1.7 - -
5/90 - 12.0 410 150 10.0 -
4/91 0.68.1 0.7 34.0 8.0 0.3 -
MW-10A 10/87 - - 3.9.1 3.7.1 - -
1/88 - - 3.0 3.0 - -
10/88 - - 4.78 5.28 - -
4/91 0.78.1 0.1 5.0 6.0 - -
MW-108 10/87 - - - - - -
1/88 - - - - - -
10/88 - - - - - -
4/91 - - - - - -
MW-llA 1/88 - - 29.0D 1.8 - -
10/88 0.87 0.43 91.0D 9.4 0.5 -
4/91 1.08.1 0.5 130D 7.0 0.4 -
MW-1l8 1/88 - - - - - -
10/88 - - 0.27.1 - - -
4/91 - - 0.48.1 - - -
MW-14 10/88 - 1.9 83.0 81.0 - -
MW-15 10/88 - 4.0 130 75.0 - 3.7
MW-20A 10/88 1.1 1.5 83.0.1 32.0 3.6.1 1.5
5/90 - 0.5 3"3.0 5.0 2.0 0.2
4/91 0.78.1 0.7 42.08.1 10.0 2.0 0.2.1
MW-208 10/88 1.1 3.0 130.1 63.0 4.6.1 2.6
5/90 - 1.0 96.0 16.0 4.0 0.5
4/91 2.08.1 1.08.1 63.08.1 20.0 2.0 0.5
MW-25 10/88 - - - - - - -
1!r
MW-34A 6/90 49.0 0.6 0.0 2.0 - -
4/91 30.0 1.0 8.0 5.0 - -
MW-34C 6/90 9.0 0.1.1 1.0 0.5 - -
4/91 1.0 0.3 1.0 1.0 - -
MCL 5.0 5.0 200.0 NONE 7.0 NONE
ES 5.0 1.0 200.0 850.0 7.0 100.0
MW - NPI Mon1.tor1.n Well
g
(-) - Compound Was Analyzed But Not Detected
.1 - Estimated Value
D - Initial Analysis Exceeded Calibration Range,
and Reanalyzed
8 - Compound Was Also Detected In The Laboratory
MCL - Federal Maximum Contaminant Level
ES - Wisconsin Enforcement Standard
Sample Was Diluted
8lank
-------
TABLE 2
SUMMARY OF VOCS IN GROUNDWATER
OFF SITE MONITORING WELLS
ALL CONCENTRATIONS REPORTED IN UG/L (parts per
billion)
WELL
NUMBER
DATE
SAMPLED
TCE
PCE
TCA
1,1-DCA
l,l-DCE
1,2-DCE
RW-2A 7/89 3.0 0.08J 1.0 - - -
5/90 2.0 - 0.8 - - -
4/91 3.0BJ - 0.9 - - -
RW-2B 7/89 5.0 0.2J 1.0 0.3 - -
5/90 4.0 - 1.0 0.2 - -
4/91 4.0 0.2J 1.0 - - -
RW-2C 7/89 6.0 0.2J 2.0 0.5J 0.06J -
5/90 6.0 0.2J 2.0 0.5 O.lJ -
4/91 6.0 0.3 - 2. 0 0.5 - -
MW-9A 10/88 - - 55.0 - 2.0 -
5/90 - - 56.0 - 1.0 -
MW-9B 10/88 0.2J 0.14J 7.5B 0.26B - -
5/90 - - 4.0 - 0.2J -
RW-15 9/89 9.0 0.8 100D 4.0J 4.0 O.lJ
5/90 10.0 0.8 60.0D 3.0 3.0 0.3
4/91 8.0BJ 0.6 12.0 0.8 0.6 -
WW-15 8/89" 3.0 - 0.4 - - -
5/90 3.0 - 0.6 - - -
4/91 3.0BJ - 0.9 0.3 - -
WW-15B 4/91 2.0BJ - - - - -
WW-15C 4/91 1. OBJ - - - - -
MW-23A 10/88 0.97 - 2.3 1.5 - -
5/90 2.0 0.3 49.0D 5.0 1.0 -
4/91 3.0BJ 0.4 43.0 5.0 0.9 -
MW-238 10/88 1.5 0.29 9.5 6.4 - -
5/90 3.0 0.6 57.0D 8.0 2.0 -
4/91 3.0BJ 0.4 40.0 5.0 0.8 -
MW-32A 7/89 0.5 0.4 22.0 3.0J 1.0 O.lJ
5/90 0.4 0.4 41.0 6.0 2.0 0.3
4/91 0.8BJ 0.5 36.08J 13.0 2.0 0.4
MW-32B 7/89 0.7 1.0 -55.0 16.0 3.0 0.7
5/90 0.6 1.0 57.0 18.0 2.0 0.8
4/91 1.OBJ 0.9 42.0BJ 13.0 2.0 0.4
MW-33A 7/89 - - 0.7 - - -
5/90 - - 7.0 0.6 0.7 -
MW-338 7/89 1.0 0.2J _9.0 4.0J 0.6 0.09J
5/90 1.0 0.3 '12.0 5.0 0.9 -
MW-36A 6/90 - - - - - -
MW-36B 6/90 - - 0.4 - - -
MW-37A 4/91. 1.OBJ - 0.7BJ O.lBJ - -
MW-37B 4/91 2.0BJ 0.3 4.0BJ 2.0 0.3 -
MW-38A 4/91 7.0BJ 0.5 52.0 4.0 2.0 -
MW-38B 4/91 11. OBJ 1.0 70.0 5.Q 3.0 -
MW-38C 4/91 3.0BJ O.lBJ 6.0 0.6 - -
MCL 5.0 5.0 200.0 NONE 7.0 NONE
ES 5.0 1.0 200.0 850.0 7.0 100.0
MW - NPI Mon~tor~ng Well, RW - u.S. EPA Mon~tor~ng Well,
WW - WDNR Monitoring Well
(-) - Compound Was Analyzed But Not Detected J - Estimatep Value
D - Initial Analysis Exceeded Calibration Range, Sample Was Diluted
and Reanalyzed
8 - Compound Was Also Detected In The Laboratory Blank
MCL - Federal Maximum Contaminant Level
ES - Wisconsin Enforcement Standard
-------
TABLE 3
SUMMARY OF METALS IN GROUNDWATER
ON SITE MONITORING WELLS
ALL CONCENTRATIONS REPORTED IN UG/L (parts per
billion)
IlELl DAlE AlUUIIUII AIIII_Y ARSEIIIC IARlUII IERYLlIUII CADIIIUII CHROIIUII C08Al I COPPER I ROIl lEAD MERCURY IIICKEl SElEIi lUll SILVER IHAlllUII VAIIAD lUll liliC
IIUMBER SAMPLED
Mil-I 1188 IIA IIA IIA IIA IIA IIA IIA IIA IIA IIA IIA IIA IIA 120.0
10/88 IIA IIA . n.11 IIA IIA 11.68 IIA 2.'BJ IIA NA IIA IIA 210.0
MII'U 1188 IIA IIA IIA IIA IIA IIA IIA IIA 6.0 IIA IIA IIA IIA IIA 36'.0
10/88 IIA IIA 62.68 IIA IIA IIA 1.98 IIA IIA IIA IIA
1,191 1,1.3BJ 5.18 1.2BJ 'O.1BJ 2.2BJ . 250.01lJ
MII'U 1,191 'B.68J - 13.118 12.9 6.5BJ 22.5BJ 2010.0 65.111J
........- .--..... ......... ...-....... ..-.... ......... .......-.... ........- _.-..... .--_... .....---- _._-..-- ...-..-- .---... ...........- .-_........- .-----. ..........- ....-..- .........
MII.5A 1/88 IIA IIA IIA IIA IIA IIA IIA IIA IIA IIA IIA IIA IIA 14.5B
10/88 IIA IIA ' IIA 15.9J IIA 15.0B IIA IIA IIA IIA IIA 50.11
1,J91 13.58 - 1. 3BJ 6O.IIJ
Mil' 58 1188 IIA IIA IIA IIA IIA IIA IIA IIA IIA IIA IIA IIA IIA 80.'
10/88 IIA IIA 610.98 IIA 20.'J IIA \1.88B IIA IIA IIA IIA IIA 38.2
1,191 - 12.1B 2'0.OJ J.I,BJ 10.9BIIJ
---..... .....-..... .-___.0- -.--..... .....-_... -_.......- ..--....... .-_...... .....---- _.......-- -..-...... ......-- .......-. __0"--- .------ ....---- .......--- -.---..- .....-..--
M11-6 10/88 IIA IIA 70.IB IIA IIA IIA IIA IIA 3.1JB IIA IIA IIA IIA 15.7B
10/91 36.2BJ 1.18 2.5BJ 11 .OBIIJ
MIl' lOA 10/87 IIA IIA IIA 8.0 IIA 10'.0 IIA IIA IIA IIA IIA 61.0
1188 IIA IIA IIA IIA IIA IIA IIA IIA IIA 175.0 IIA IIA IIA IIA 165.0
10/88 NA IIA 5'.'B IIA 23.3 IIA 16.78 IIA IIA 135.0 IIA IIA IIA 127.0
1,191 55. 6BJ 9.98 29.1, 9.3BJ '2. 2BJ 3.6J 90.0 206.0IlJ
Mil-lOB 10/87 IIA IIA IIA '.OB IIA 115.0 IIA 6.2 IIA IIA IIA IIA 51.0
1188 IIA IIA NA IIA IIA IIA IIA IIA IIA IIA IIA IIA IIA 1,6.2
10/88 IIA IIA - 61.68 IIA ~ " "A IIA IIA NA IIR IIA 18.3B
10/91 1,9.68J . . 4.3B I. S9.4BJ 1. 5BJ 9.I,B 36.01lJ
...... -.---.- -.......... .......... ............ ......... ............ ....-.- ..........- .......... .....0"" ......... ...-... .....-. ....... ...--_.. .......-- .-----.- --..---. _......--
MII-IIA 10/88 NA IIA - IIA NA - IIA NA NA IIA IIR
4191 I,B.68J . . 6.08 - 21.68J I. 2BJ . ' 59.01lJ
111-118 11M IIA IIR ' IIA ' NA IIA IIA IIA 8.0 IIA IIA IIA IIA IIA
10/M IIA IIA . 65.1,8 IIA IIA - IIA 3.118 IIA NA IIA IIA 11.38
4191 32.I,BJ . . 1.11 . . - 1.48J - 19.3BIIJ
..-... ......... .............. ........... ....... ........ ......-....... ........- ......... ......... ........... ...-....... ........ .......- ..-_.... ......... ......... ......-... -............ ............
MIl' 178 . 10/88 IIA IIA 99.3B IIA IIA - IIA IIA IIA IIA IIA 66.2
4191 . 111.68 - 6.5BJ ' I. 7BJ . 10.1BIIJ
MII-\1c 101M IIA IIA . 11.3B IIA IIA . IIA 20.2S IIR IIA IIA IIA 22.6
10/91 52.IBJ . Il.11 . '9.68J 2.3BJ '5.8I1J
111.19 10/88 IIA IIA . 11l.08 IIA IIA 15.78 IIA IIA IIA IIA IIA 1,6.3
4191 32.I,BJ . 11.68 . - . 27. 3BJ 1. 2BJ . 30.711J
....... ................ ._.-...... -........._- .......-.. ........... ............-.. ..........- --........ .......-. -_.......- ........-- -.....-. ......... ........... ............ ............ ........... -............ ..........
11/' 20A 10/88 IIA . IIA - 81. 18 IIA . 16.0 IIA . IIA IIA IIA IIA IIA 23.6
4191 31.8BJ . '.68 . '8.8BJ 2.2BJ 58.8NJ
1II.2OB 101M IIA IIA 311.68 IIA 15.0 IIA IIA IIA IIA IIA IIA
4191 . '.68 . I. 1BJ 12.I,BIIJ
MII.3U 4/91 5'.68 - 21. 18 - 26.0B 1.2B 18.3B 50.3J
MIl- 3108 4/91 6.3B 16.I,B 3.8BJ 55.2J
MIl . IIPI MoOl tOrlng Well J hUllated vir ue
c -) . Metll III' AnalYled Bul 1101 Detected
IIA - 1I0t AnllYled
8 - Oelected At less Ihln Ihe Contrlcl Required Delecllon limit
But Crelter Ihen Ihe Instr.-nt Oetection Ii.lt
II . Spiked S...,le Recovery lIot lIithln Control Ii..ils
S - Vllue Oeter.ined By Method 01 Sllrdard Addition
-------
TABLE 4
SUMMARY OF METALS IN GROUNDWATER
OFF SITE MONITORING WELLS
ALL CONCENTRATIONS REPORTED IN UG/L (parts per
billion)
WELL DATE ALIIII... ANTlIIDIIT AIISENIC WIlli IElnllUlt CADIIIIII CNIOIIIIII CDIAL T COPPEI II'" LEAD MElCURT NICKEl SELEHIIII SILVE. THALlIlII VANAD 1111 ZINC
Hlll8ER SAMPLED
1"-2A 3/86 97'S NA NA 351 NA 138 1480 . . NA . 148
4191 79.48 . . 13.81 6.58J 62.28 . . . 25.2J
.",21 3/86 NA NA 12 0.5 HA 158 34 HA . 108
4/91 . 6.31 . 29.4J
."'2c 3/86 270 NA HA 13 HA 178 17 HA 7.58 108
4191 6.118 20.28 40.7J
.-..--- -.......... ........... ............ ........... .......... ...-......--- ....... ---_.--- ....... .-..-.... ............. .....-.- ........ ......... ............ ........... .......... ........ .".......
1II/'9A 10/88 HA 43.98 HA HA HA NA NA HA NA
111/-98 10/88 NA NA . 48.88 NA HA NA ' NA NA NA NA .
1"'15 4/91 . . . 25.81 6.58J 20.18 9.28 ' " 68.7J
"."""" ............ .....-..-.- -............ .........-- ............. .............- ............. .......... ........- --......-. ---........ ............. .-........ .............. .............. ""-.."" ........-- --.-.-... ......_--.
1II/.23A 10/88 HA NA 17.18 HA NA NA NA NA NA NA
4191 70.88J 10.18 6.5BJ 74.08J 1.3BJ 20.5J
MII- 238 10/88 NA NA 61.58 HA NA HA HA NA NA NA
4/91 36.88 6.38 ' 14.0J 6.5BJ ' - - . . 7J.6J
............ .-.......... ..-.......... ............... ....o..... ............ "-"..".." ------- ............. .......... ............ -.......... .-........ ......... .......-..- ........... ........... ............. -."""""" ........-..
MIl' 32A 4/91 - . 34.38 :~I '. - . 10.2BJ
,
111/.328 4191 - . 28.08 . - . - . -
111/- 3aA 4191 . 19.68 - . . - . 44.6J
111/- 388 4/91 19.18 7.2BJ 71.38 2.48J 7.18 - 41.1J
111/. 38C 4191 94.38 . 7.58 8.91 - 4.48 12.2BJ 97.68 7.0J 7.38 138.0J
........ .......... .............. ........... .............. ..... ..... "."..".". -......... ---.......... ............. ............ -............ --........ .......-. ........... .."..""" ............ .............. .............. ...........
MIl' 39A 4/91 - 12.11 . - - . . 32.4J
111/' 398 4/91 31.18 . . 7.11 - 66.98 . 62.1J
'8'01 4/91 . . . 4.18 - 51.0 26.08 3.1J - 302.0J
'8'02 4/91 - - 4.31 - - 42.4 1.7BJ 50.6J
f8-03 4/91 . 7.58 46.7 2.28J - 361.0J
111/ . NPI Monitor I, \1811 - ." U.S. EPA Monltorl. llell
118
118
C.) - lot Detected
f8 - Field 81enk
NA . Hot Anal Yled .
8 . Oetected At Less Ihln The Contract .equlred Detection LI.Jt
But Greater Ih8rl The Inst..-nt Detect Ion LI.I t
J- htl..ted V.I..
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11
NPI is presently conducting additional field work near the Eau
Claire County Airport that includes the installation and sampling
of monitoring wells. This additional work is being conducted in
accordance with the approved RIfFS Work Plan for the Facility which
requires NPI to track groundwater contamination originating at the
NPI Site. New data will be included in the information
repositories as it becomes available.
TABLE 5
SUMMARY OF VOCS IN GROUNDWATER
SPLIT SAMPLES COLLECTED BY U.S. EPA - APRIL 1991
ALL CONCENTRATIONS REPORTED IN UGfL (parts per billion)
WELL
NUMBER
DATE
SAMPLED
TCE
PCE
TCA
l,l-DCA
l,l-DCE
1,2-DCE
RW-15 4/91 9.8 0.6.1 18.7 - 1.3 -
MW-34A 4/91 30.7D 1.6 10.2 7.4 - -
MW-34B 4/91 0.8.1 0.2.1 2.6 1.9 - -
MW-37A 4/91 0.5.1 - 1.0.1 0.2.1 0.1.1 -
MW-37B 4/91 1.3 - 6.3 2.3 0.4.1 -
MW-38B 4/91 14.9 - 93.5D 8.0 6.8 0.3
FB-01 4/91 - - 0.2.1 - - -
FB-02 4/91 - - - - - -
TS-01 4/91 - - 0.3.1 - - -
TS-02 4/91 - - 0.2.1 - - -
TB-03 4/91 0.1.1 - 0.3.1 - - -
TB-04 4/91 - - - - - -
TS-05 4/91 0.2.1 - - - - -
MCL 5.0 5.0 200.0 NONE 7.0 NONE
ES 5.0 1.0 200.0 850.0 7.0 100.0
MW - NPI Mon~tor~ng well, RW - U.S. EPA Mon~tor~ng Well
FB - Field Slank
TB - Trip Blank
(-) - Compound Was Not Detected
.1 - Estimated Value Below Laboratory Detection Limit
D - Initial Analysis Exceeded Calibration Range, Sample Was
and Reanalyzed
MCL - Federal Maximum Contaminant Level
ES - Wisconsin Enforcement Standard
Diluted
:"I"-=:'
Confirmatory sampling of all newly installed and selected on- and
off-site monitoring wells will be conducted in early Fall 1991.
Analytical parameters will include the full Target compound List
(TCL) and Target Analyte List (TAL) for organic compounds and
inorganics, respectively. Data will serve to confirm the findings
of the sampling conducted in early 1991, determine the need for
additional pretreatment of extracted groundwater beyond that
provided in the selected remedy, satisfy Wisconsin Pollutant
Discharge Elimination System (WPDES) permitting requirements, and
support the evaluation and selection of remedial alternatives for
off-site groundwater and on-site source areas.
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12
VI.
SUMMARY OF SITE RISKS
CERCLA requires that u.s. EPA protect human health and the
environment from current and potential exposure to hazardous
substances found at a facility. As part of the ongoing RIfFS at
the NPI Facility, u.s. EPA will prepare a baseline risk assessment.
The baseline risk assessment determines whether contamination at
the Facility could pose. an unacceptable health risk or
environmental risk in the absence of any remedial action.
Potential threats to public health are estimated by making
assumptions about the manner, frequency and length of time a person
could be exposed to site-related contaminants.
As part of the 1990 ROD for the permanent replacement of
contaminated drinking water supplies in the affected area, U.S. EPA
evaluated potential health risks for the groundwater ingestion
pathway at the Facility. These risks were estimated for each
individual private well and monitoring well in the affected area
exhibiting contamination and within the groundwater flow path from
the on-site source through the affected area. Assuming continued
consumption of contaminated groundwater within the affected area,
U.S. EPA calculated a potential carcinogenic risk range of 9 x 10-7
(9 in 10 million) to 2 X 10-4 (2 in 10,000) for the groundwater
ingestion pathway for the combined effects of the contaminants of
concern detected in private wells and monitoring wells. The
greatest potential risk is posed by contaminants detected in
monitoring wells at the Melby Road Disposal Area.
A draft baseline risk assessment report for the Facility was
prepared by U.S. EPA in November 1990. The draft risk assessment
was based primarily on RI data collected prior to June 1990. The
draft risk assessment will be updated as part of the final RIfFS
for the Facility to reflect the additional data collected since its
initial preparation. The final risk assessment will quantify
potential risks to human health and the environment from
contamination at the Facility, ~ncluding the consumption of
contaminated groundwater within eaCh of the identified contaminant
plumes.
The 1990 ROD addressed the principal threat to human health posed
by contaminated groundwater at the Facility--contaminated drinking
water supplies in the affected area. However,. degradation of the
environment is continuing through the release of contaminants to
soils and groundwater from on-site source areas.. Groundwater
contaminated with VOCs at levels above MCLs and Wisconsin
groundwater quality standards continues to move north from the Site
through the affected area to Lake Hallie and west from the Site
toward the Eau Claire municipal well field and 'Chippewa River.
Consistent with U.S. EPA pOlicy, "Role of Baseline Risk Assessment
in Superfund Remedy Selection Decisions" dated April 22, 1991,
exceedences of MCLs and Wisconsin ESs alone justify this interim
action. Additionally, actual or threatened releases of hazardous.
,.....
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13
substances from the Facility, if not addressed by the preferred
alternative or one of the other active measures considered, may
present a current or potential threat to public health, welfare or
the environment.
VII.
DESCRIPTION OF ALTERNATIVES
NPI and its consultant conducted a PFS that identified and
evaluated in detail seven alternatives to address on-site
contaminated groundwater. These alternatives are summarized below
and are discussed in greater detail in the PFS.
Alternative 1 - No Action
The Superfund program requires that. a "no-action" alternative be
evaluated at every facility to establish a basis for comparison
with the other alternatives considered. Under this alternative, no
corrective action regarding groundwater would take place at the
Facili ty. Further groundwater degradation and migration would
occur since contaminant plumes containing VOCs at levels above MCLs
and Wisconsin groundwater quality standards would continue to move
off site in both northerly and westerly directions. Plume 3 would
continue to originate at the Melby Road Disposal Area and flow to
the northwest into the buried valley and then northesterly to Lake
Hallie where it discharges. Plume 2 would continue to originate in
the Lagoon I-Ditch No.3 vicinity and flow westward into the buried
valley and toward the Eau Claire municipal well field and the
Chippewa River. The No Action Alternative does not comply with the
action-specific requirements of Chapter NR 140, Wisconsin
Administrative Code (WAC) regarding implementation of appropriate
response action(s) for exceedances of ESs. There are no costs
associated with implementation of Alternative 1.
Alternative 2 - Groundwater Collection and Discharqe to Sanitary
Sewer
Under this alternative, a series Of groundwater extraction wells
would be installed along the northern property line of the NPI site
at the Melby Road Disposal Area and in the southwestern portion of
the site downgradient of Lagoon No.1 and Drainage Ditch No.2.
Groundwater would be pumped from these wells to capture and remove
contaminated groundwater, thus preventing further off-site movement
of VOCs in groundwater from these source. areas. Extracted
groundwater would then be discharged into the sewer system for the
city of Eau Claire where the water would be treated at the City's
wastewater treatment plant (Publicly-Owned Treatment Works or
POTW). Implementation of this alternative would require
construction of a pipeline from the extraction wells to existing
on-site sanitary sewers.
A pump test was recently completed at the Melby Road Disposal Area
to define aquifer characteristics. (There are presently two 5-inch
-- .
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14
diameter wells with 40 feet of screen installed from the water
table to the top of the bedrock formation at the Melby Road
Disposal Area). Based on interpretation of the data, it is
estimated that these two extraction wells pumping at a total
combined rate of 200 gallons per minute (gpm) will sUfficiently
capture the contaminant plume at the Melby Road Disposal Area.
Assuming the same aquifer characteristics at the southwestern
portion of the Site, it is estimated that an additional two to
three 5- to a-inch diameter extraction wells pumping at a combined
rate of 200 to 300 gpm would be required to capture contaminated
groundwater from the southwestern portion of the Site. For
.purposes of developing cost estimates, it is assumed that three
extraction wells will be required in the southwestern portion of
the Site. However, final parameters of the groundwater extraction
system would be determined and refined during remedial design and
implementation of the selected remedy. A description of the
aquifer pumping test and a discussion of the results are presented
in a summary report that is included in the administrative record
for the Facility.
Groundwater recovered by capture wells at the Melby Road Disposal
Area would be pumped approximately 1,000 feet to a manhole on site
where the discharge pipe can be connected to an a-inch sanitary
sewer line. Groundwater collected at the southwestern portion of
the site would be pumped approximately 600 feet where the discharge
would be connected to a 15~inch sanitary sewer line located on
site.
Long-tert:1 groundwater monitoring would be required to measure
progress and performance of the groundwater extraction and
treatment system, verify completeness of contaminant plume capture
and ensure that the groundwater discharged to the sanitary sewer
complies with POTW limits established pursuant to the City of Eau
Claire's approved pretreatment program. The pretreatment program
requires a municipality to establish local limits for influent into
a POTW from a POTW user. Existing groundwater data indicates that
POTW limits would not be exceeded; however, should future
monitoring show concentrations above POTW limits, an appropriate
form of pretreatment would be required prior to discharge to the
POTW.
All ARARs relating to the removal and disc};large of untreated
groundwater to the Eau Claire POTW would be met, including influent
limits established under Eau Claire's pretreatment program and in
accordance with the Clean Water Act (CWA). Extraction wells and
groundwater monitoring wells would comply with Chapters NR 112 and
141, WAC, respectively, which establish design, installation and
construction requirements. Treated effluent from the POTW would
comply with WPDES permit requirements for discharge to surface
water. The action-specific requirements of Chapter NR 140, WAC are
satisfied by the extraction of contaminated groundwater at the on-
site source areas.
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15
Estimated capital costs for implementation of Alternative 2 would
total $194,000; estimated yearly operation and maintenance costs
would total $156,000 for the first year and $105,000 for each year
thereafter. The 30-year present worth of Al ternati ve 2 would equal
approximately $1.23 million. These estimated costs do not include
user fees for NPI's use of Eau Claire's POTW or pretreatment costs,
if necessary.
Alternative 3A - Groundwater Collection, on-site Treatment bv
Cascade Aeration and Discharae to the Chi1)1)ewa River via storm
Sewer
Under this alternative contaminated groundwater would be captured
and removed by the same series of extraction wells discussed for
Al ternati ve 2 and treated by two cascade aeration structures
located on site. Treated groundwater would then be discharged via
storm sewers to the Chippewa River.
The two extraction wells located at the Melby Road Disposal Area
would pump at a combined flow rate of 200 gpm. The recovered
groundwater woUld be pumped approximately 1,500 feet to a cascade
aeration unit. FOllowing cascade aeration, the treated groundwater
would be discharged to an existing 12-inch City of Eau Claire
concrete storm sewer located on the NPI site and near the cascade
aeration unit. Implementation of this alternative would require
permission from the city of Eau Claire. In addition, some sewer
retrofitting will be necessary to clear the s.torm sewer lines,
which have been blocked off and/or redirected in several locations.
Two to three wells located in the southwestern portion of the site
would pump at a combined flow rate of 200-300 gpm. The extracted
groundwater would be pumped approximately 600 feet to a second
cascade aeration unit and discharged to an existing 24-inch storm
sewer, also located on the NPI site and near the second aeration
unit. It is not expected that cold weather will significantly
reduce the efficiency of the cascade aeration system. However, if
necessary, the system will be modified to maintain maximum VOC
removal during the winter months. This may include enclosing the
cascade aeration structure or installing heating coils to reduce
icing.
For cost estimates and comparative analysis of alternatives, it is
assumed that three a-inch extraction wells will be required in the
southwestern portion of the site and that a cascade aeration system
comprising a concrete step structure nine feet in height would be
sufficient to meet BAT treatment requirements. It is also assumed
that the on-site storm sewers will adequately transport groundwater
to the Chippewa River. .. .
Long-term monitoring would be necessary to measure progress and
performance of the groundwater extraction and treatment system,
verify completeness of contaminant plume capture, determine the
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16
need for additional treatment of extracted groundwater and monitor
compliance with Wisconsin Pollutant Discharge Elimination System
(WPDES) discharge limits for effluent discharge to the Chippewa
Ri ver. Water samples would be analyzed for u. S. EPA' s Target
Compound List (TCL) and Target Analyte List (TAL) parameters for
organic compounds and inorganics, respectively, for purposes of
determining the need for addi tional treatment of contaminated
groundwater prior to cascade aeration and to monitor compliance
with the requirements of a WPDES permit for discharge of treated
groundwater to the Chippewa River. Based on existing groundwater
data, no additional treatment of extracted groundwater beyond
cascade aeration will be required to comply with WPDES permit
requirements.
Alternative 3A would comply with all ARARs relating to the removal
and treatment of contaminated groundwater, including the action-
specific requirements of Chapter NR 140, WAC. Section 301{b) (2) of
the CWA requires the application of economically and
technologically achievable Best Available Technology (BAT) to treat
pollutants prior to discharge. BAT requirements of the CWA are
determined on a case-by-case basis by WDNR pursuant to Chapter NR
220, WAC. WDNR has determined that cascade aeration satisfies the
BAT requirements of the CWA and Chapter NR 220, WAC. Groundwater
extraction wells and monitoring wells would comply with Chapters NR
112 and 141 which establish minimum criteria for their design,
construction and installation. Discharge of treated groundwater to
the Chippewa River would comply with water quality standards and
WPDES permit requirements pursuant to Chapters NR 102, 104, 105 and
106, WAC. Emissions of VOCs to the atmosphere by cascade aeration
would comply with Wisconsin's air quality standards pursuant to
Chapter NR 445, WAC.
Estimated capital costs for implementation of Alternative 3A would
total $255,000; estimated yearly operation and maintenance costs
would total $163,000 for the first year and $104,000 for each year
thereafter. The 30-year present worth for Alternative 3A would
equal approximately $1. 29 milliotff If additional treatment of
contaminated groundwater is required, both capital costs and yearly
operation and maintenance costs will increase.
Alternative 38 - Groundwater Collection, On-site Treatment bv Air
Strig~ina Tower and Discharae to the Chig~ewa River via storm Sewer
This alternative is identical to Alternative 3A with the exception
that, in lieu of an on-site cascade aeration treatment system, an
air stripping tower would treat contaminated groundwater prior to
discharge, and the discharge would be to the Chippewa River.
.
Collected groundwater from the Melby Road Disposal Area would be
pumped approximately 5,000 feet to the southwest portion of the
Site where one air stripper would treat the combined flow from both
extraction systems. The air stripping tower would be designed to
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17
maximize VOC removal. Treated groundwater would then be discharged
to the Chippewa River by way of a City of Eau Claire storm sewer
located on the NPI site. As with Alternative 3A, use of the storm
sewers would require permission from the city of Eau Claire.
operation and maintenance of the treatment system would include
routine maintenance of the pumps, fans and electrical systems, and
replacement of the air stripper packing which would be
appropriately disposed in a properly designed and approved
landfill.
As with Alternatives 2 and 3A, long-term monitoring would be
necessary to measure progress and performance of the groundwater
extraction and treatment system, verify completeness of contaminant
plume capture, determine the need for any additional treatment of
extracted groundwater and monitor compliance with WPDES permit
requirements for discharge of treated groundwater to the Chippewa
River.
The ARARs identified for Alternative 3B are the same as those for
Al ternati ve 3A, and would be met wi th the implementation of
Alternative 3B.
For purposes of estimating costs, it is assumed that the on-site
storm sewer will be of sufficient capacity to receive and transport
treated groundwater to the Chippewa River. Estimated capital costs
for implementation of Alternative 3 would total $336,000; estimated
yearly operation and maintenance costs would total $182,000 for the
first year and $124,000 for each year thereafter. The 30-year
present worth of Alternative 3B would equal approximately $1.56
million. As with Alternative 3~, if further metals testing
indicates a need for additional treatment prior to discharge to the
storm sewer , capital costs and operation and maintenance costs
would increase accordingly.
Alternative 4A - Groundwater Coll-ection. on-site Treatment bv
Cascade Aeration and Discharae to Lake Hallie via Installed pi~e
Under this alternative, groundwater would be collected from the
extraction well system described in Alternative 2. Groundwater
recovered from the southwestern portion of the Site would be pumped
approximately 5,000 feet to the Melby Road Disposal Area. A single
cascade aeration unit would be constructed. at the Melby Road
Disposal Area to treat all extracted groundwater.
Following treatment, the water would be pumped approximately 5,500
feet through a dedicated 6-inch pressure line to Lake. Hallie. A
pump station would be installed to pump the water'to Lake Hallie.
There is approximately a 100-foot elevation drop to the lake at the
proposed outfall location. Thus, it is likely that the discharge
pipe would extend down the steep slope and into the water to avoid
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18
erosion that would occur if the outfall was 100 feet above the
shoreline.
Easements would likely be necessary and/or land purchased to
install the pipeline. In addition, the Lake Hallie shoreline is
privately owned at the proposed outfall location, therefore it
would also be necessary to obtain rights to the shoreline.
Long-term moni toring would be required to measure progress and
performance of the groundwater extraction and treatment system,
verify completeness of contaminant plume capture, determine the
need for any additional treatment of extracted groundwater, and
monitor compliance with WPDES permit requirements for discharge of
treated groundwater to Lake Hallie.-
For cost estimates and comparative analysis of alternatives, it is
assumed that a cascade aeration system comprising a concrete step
structure nine feet in height would be sufficient to meet BAT
treatment requirements.
ARARs identified for Alternatives 3A and 3B also apply to
Alternative 4A. In addition, Alternative 4A would comply with
Chapter 30, Wisconsin statutes, which specifies permit requirements
for new construction that may impact navigable waters in the state
of Wisconsin.
Estimated capital costs for implementation of Alternative 4A would
total $510,000; estimated yearly operation and maintenance costs
would total $200,000 for the first year and $142,000 for each year
thereafter. The 30-year present worth of Al ternati ve 4A would
equal approximately $1. 9 million. These cost estimates do not
include the purchase or lease of any land required to access Lake
Hallie. As with Alternatives 3A and 3B, additional treatment of
contaminated groundwater would increase capital costs and operation
and maintenance costs.
Alternative 4B - Groundwater Co11eation. On-site Treatment bv Air
striDDina Tower and Discharae to Lake Hallie via Xnsta1led Pige
Under this alternative, groundwater would be collected by the
previously described extraction system, treated in an on-site air
stripping tower, and discharged to Lake Hallie through the
dedicated pipe described under Alternative 4A. The groundwater
recovered at the southwest portion of the Site would be pumped
approximately 5,000 feet to the Melby Road Disposal Area. The
combined flow from all extraction wells would be treated in an on-
site air stripping tower prior to discharge to Lake Hallie through
the dedicated pipe. Locating the air stripper on'site would
require installation of a pump station to convey the treated
groundwater to the lake. .
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19
operation and maintenance of the treatment system would include
routine maintenance of the pumps, fans and electrical systems, and
replacement of the air stripper packing, which would be
appropriately disposed in a properly designed and approved
landfill.
As with Alternative 4B, easements would likely be necessary and/or
land purchased to install the pipeline to Lake Hallie. In
addition, the Lake Hallie shoreline is privately owned at the
proposed outfall location, therefore it would also be necessary to
obtain rights to the shoreline.
Long-term monitoring would be required to measure progress and
performance of the groundwater extraction and treatment system,.
verify completeness of contaminant plume capture, determine the
need for any additional treatment of extracted groundwater, and
monitor compliance with WPDES permit requirements for discharge of
treated groundwater to the Chippewa River.
Alternative 4B would comply with all identified ARARs, which are
identical to those stated for Alternative 4A.
Estimated capital costs for implementation of Alternative 4Bwould
total $572,000; estimated yearly operation and maintenance costs
would total $216,000 for the first year and $144,000 for each year
thereafter. The 30-year present worth of Al ternati ve 4A would
equal approximately $2 million. These costs .estimates do not
include the purchase or lease of any land required to access Lake
Hallie. As. with other alternatives involving remedial action,
additional treatment of contaminated groundwater would increase
capital costs and operation and maintenance costs.
Alternative 5 - Groundwater Collection. On site Treatment bv Air
striooina Tower and On-Site Recharae
Under this alternative, the same se~ies of groundwater extraction
wells previously described would cdilect contaminated groundwater
from the Melby Road Disposal Area and the southwestern portion of
the site. An air stripping tower would be constructed in the
vicini ty of' Lagoons 3 and 4. Groundwater collected from the
southwestern portion of the Site and the Melby Road Disposal Area
would be pumped approximately 4,000 feet and 1,500 feet,
respectively, to the air stripper for treatment.. The treated water
would then be pumped to Lagoons 3 and/or 4 which would serve as
groundwater recharge basins.
operation and maintenance of the treatment system would include
routine maintenance of the pumps, fans and electri~al systems, and
replacement of the air stripper packing, which will be
appropriately disposed in a properly designed and approved
landfill.
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20
Long-term monitoring would be required to measure progress and
performance of the groundwater extraction and treatment system,
verify completeness of contaminant plume capture, determine the
need for any additional treatment of extracted groundwater, and
monitor compliance with WPDES permit requirements for discharge of
treated groundwater to the recharge lagoons.
Alternative 5 would comply with all identified ARARs which are the
same as those identified for Alternatives 3A and 3B, except for
those applicable to the point of discharge. Since extracted and
treated groundwater will be returned to the soil surface for
infiltration and percolation to the water table, the cleanup levels
for contaminants of concern in the treated groundwater are the
Wisconsin Preventive Action Limits, (PALs), as defined in Chapter
NR 140, WAC, which are more stringent than surface water quality-
based criteria.
Estimated capital costs for implementation of Alternative 5 would
total $373,000; estimated yearly operation and maintenance costs
would total $186,000 for the first year and $125,000 for each year
thereafter. The 30-year present worth of Alternative 5 would equal
approximately $1.61 million. As with other alternatives involving
remedial action, pretreatment of contaminated groundwater would
increase capital costs and operation and maintenance costs.
VIII.
SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
In order to determine the most appropriate alternative for this
interim remedial action that, to the maximum extent practicable, is
protective of human health and the environment, attains ARARs, is
cost-effective, and utilizes perrganent solutions and treatment
technologies, the remedial alternatives developed in the PFS have
been evaluated and compared using the nine criteria, as determined
to be applicable to this interim action, set forth in Section
300.430(e) (9) (iii) of the National contingency Plan (NCP) and
Section 121 of CERCLA (Cleanup Sta~ards). The nine criteria and
a brief description of each is listed below.
*
Overall Protection of Human Health and the Environment
addresses whether or not a remedy provides adequate
protection and describes how risks posed through each
exposure pathway are eliminated, reduced or controlled by
means of treatment, engineering controls, or
institutional controls.
*
ComDliance With ARARs addresses whether or not a remedy
will meet all of the applicable or relevant and
appropriate requirements of other federal and state
environmental statutes and/or provide grounds for
invoking a waiver.
- .
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21
*
Lona-term Effectiveness and Permanence refers to the
ability of a remedy to maintain reliable protection of .
human health and the environment over time once cleanup
goals are achieved. .
*
Reduction of Toxicitv. Mobilitv. or Volume refers to the
preference for a remedy that uses treatment to reduce
health hazards, contaminant movement or the quantity of
contaminants at the site.
*
Short-Term Effectiveness addresses the ability of a
remedy to provide reliable protection of human health and
the environment during the period of time needed to
achieve protection, and - any adverse impact on human
health and the environment that may be posed during the
construction and implementation period until cleanup
goals are achieved.
*
Implementabilitv is the- technical and administrative
feasibility of a remedy, including the availability of
materials .and services needed to implement a particular
option.
*
Cost includes estimated capital and operation and
maintenance costs, also expressed as net present worth
costs.
*
State Acceptance indicates whether, based on its review
. of the FS and proposed plan, the state concurs, opposes
or has no comment on the preferred alternative.
*
communi tv Acceptance summarizes the pUblic's general
response to the alternatives described in the proposed
plan and in the RIfFS, based on public comments received.
Public comments, and the Agency's response to these
comments, are presented _in the Responsiveness Summary
attached to the ROD. ~
A summary of the evaluation for each alternative is presented in
Table 6. Following the individual evaluations, alternatives were
compared in order to identify the alternative providing the best
balance among those criteria that are applicable to the interim
remedial action. The results of the compar-ison are discussed
below.
A.
Threshold criteria
The first two criteria of the NCP--overall protection and ARARs
compliance--are the two most important criteria. . They are
statutory requirements that must be satisfied by any alternative in
order for it to be eligible for selection. These two criteria are
discussed below.
-------
Evat uat Ion Cr Iter i.
Overall Protection of Hu.an
Heatth & the Environment
Conptlance with State and
Federet Reguletions (ARARs)
long-Term Effectiveness and
Pennanence
.
Reduction of Toxicity.
Mobility and Volume
. TABLE 6
DETAILED EVALUATION OF REMEDIAL ALTERNATIVES
(Excluding State and community Acceptance)
Atterllltive ,
No Action
Doel not offer any
protection. Groundwater
cont..illlted wi th VOCs above MCI.
and ESI continues to move off-
site fr~ Melby Road Disposal
Aree end soulhwestern port Ions of
the Site. Potential risks frDIII
Ingestion of groundwater In ptu.
] range fr~9J1'0" t02xI0".
Does not comply with action-
specific requirements of Chapter
NR ''"0, IIAC.
I~{
Provides no long term
,ef fect I veness or perlnanence.
Groundwater contaminated wi th
YOCI above MCls, wisconsin
groundwater standards and health-
based levets cont inues to move
off site.
This interim remedial action does
not addresa reduction in TMY
AI ternat ive 2
Groundwater Collection &
Dlscherge to Eau Claire POTII
Recb:es potential risks frDIII
groundwater ingestion at source
areas. Mitigates degradation of
groundwater downgradient of
source areas and prevents off.
site migration of contaminant
plumes thrOugh collect ion of
contaminated groundwater at
source areas followed by
discharge to POTII. Does not
address off-site contaminated
groundwater or on-site source
areas.
Influent to POIII will comply with
local Ilmi ts. report ing
requirements and any pre-
treatment standards. Effluent
standards will be met for
discharge from POTII to surface
water. Extract ion well s must
compl y with appl icable state
codes regarding well construct Ion
and ...... Install at ion. long- term
cteanup goal s for groundwater sre
IIlsconsin PAls. New monitoring
wells would compl Y wi th state
design and installation
requirements.
Alone, does not provide adequate
long term control of
contaninants. Source areas
continue to release cont..lnants
to sol I and groundwater. Through
continued operation, inter I.
remedial action prevents off site
movement of contaminated
groundwater frOft on-site source
ereas. and may achieve
groundwater cleanup goals over an
extended time frame with adequate
source control. long-term
management Includes; monitoring
quat Ity of water" extracted,
in-ground and prior to discharge
to Chippewa River, and rout loe
Nlntenanee.
Same as Alternat Ive 1
AUernat I ve 3A
Groundwater 'Collectlon. On-Site
Treatment by Cascade Aeration &
Discharge to Chippewa River vie
Storln Sewer
Recb:es potential risks front
, groundwater ingest ion et source
ereas. Mitigates degradation of
groundwater downgradlent of
SOUrce areas and prevents off.
site migration of contBIIlnent
pi umes through coli ec t I on of
contaminated groundwater et
Source areas, on-site treatment
and dlscherge to the Chippewe
River. Does not address off-site
contaminated groundweter or on-
site source areas.
Eff luent standards wi II be lllet
for treated groundweter
discharged to the Chippewe River.
Transfer of VOCs frDIII groundweter
to air will conply with 8It>lent
air quality standards.
Extract ion wells IlUSt comply with
applicable state 40cfes regarding
well construction and ~
installation. long' term cleanup
levets for groundwater are
lIisconsln Pals. New monitoring
wel ts would conply with state
design and installation
requi rement s.
Same as Alternative 2
Same as Alternat ive 1
AHernet lve 39
Groundwater Collection, On-Site
'reatment by Air Stripper &
Dlscherge to Chippewa River vie
Storm Sewer
Same 8S Alternative 3A
SIMe as Alternative 3A
Same as AI ternat ive 2
SUllIe 8S Alternative 1
-------
Evaluation Criteria
Short-lerm Effectiveness
Protection of community
during remedial action
Protect ion of workers during
remedial action
lime until remedial
object ives are achieved
.
Alternat ive ,
No Action
Provides no short-term
effectiveness. Potential risks
from groundwater ingestion would
cont lnue; however, not under
current groundwater use scenario
and with futl i~tenentatlon of
reptac:e8ent drinking water
s"Wtles In the affected area.
Not Applicable
:~I
In the absence of source control,
remedial object Ives wit I probably
never be met. On-site reteases
to soils and groundwater would
cont inue and contaminated
groundwater woutd continue to
move off-site 'rom the Melby Road
Disposal Area and southwestern
portions 0' the Site.
AI ternat ive 2
GroundWater Collection and
Discharge to fau Claire POTY
No risks to community as all
groundwater extraction welts
would be instalted on site and
contaminated groundwater would be
discharged directly to the (au
Claire POT". If additionat off-
site sanitary sewer capacity is
required, some disruption to the
community will likely occur
during instaltation of pipe from
extraction wells to sanitary
sewer(s). .
During instaltat ion of ext ract iOn
wells, drillers would be required
to coqlly with the protection
levels and safety measures
specified in the approved Health
and Safety Plan for the Site.
for other components of the
remedial act ion, workers would be
subject to normal and customary
construction risks. Maintenance
0' extraction system poses
potential exposure risks to
workers.
Objectives of this interim action
would be Met quickly as of' site
IIIOvement 0' contaminated
groundwater would be prevented
through collection at on-site
source areas. 1 illlll until long'
term cleanup goals are achieved
In groundwater would be
cont ingent on remedlat ion and/or
containment of waste ~terlals
and contaminated soils at the
.source areas and appropr I ate
remedial noeasure(s) for off.site
groundwater.
Alternative 3A
Groundwater Collection, On-Site
Treatment by Cascade Aeration &
Discharge to Chippewa River via
Storm Seller
No risks to community as all
extract ion well s would be
Installed on site and
contaminated groundwater would be
discharged, following on-site
treatment, to the Chippewa River
through a storM sewer(s). VOC
emissions 'rom cascade serat ion
would comply with ~Ient air
quail ty standards. If add It I one I
off-site storll sewer capacity Is
required, some disruption In
trait ic will likely occur during
Instaltat ion of pipe from the
Site to the star. sewer(s).
Our ing installat ion of extract Ion
wells, drillers would be required
to coqll y with the protect Ion
levels and safety measures
specified In the approved Health
and Safety Plan for the site.
for other coq>onents 0' the
renedial action, workers would be
subject to norml and customary
construction risks. Maintenance
of extract Ion and (reatment
system poses potential exposure
risks to workers.
Same as Alternative 2
Alternat ive 38
Groundwater Coltect ion, On-Site
Treatment by Air Stripper &
Discharge to Chippewa River via
Star.. Seller
NO risks to community as alt
extract ion wells would be
instalted on site. VOC
emissions from air stripper
would coqlly with ambient air
quality standards. Air stripper
would be constructed on site
away from residential areas and
active areas 0' NPI Site. tf
add It lonel off. s Ite storm sewer
capacl ty Is requl red, some
disrupt ion In traff ic will
likely occur during installation
of pipe from the Site to the
stor.. sewer(s).
Same as AI ternat Ive 3A
Same as Alternative 2
-------
Evaluation Criteria
Alternative 1
Mo Action
Alternative 2
Groundwater Collection and
Discharge to Eau Claire POTU.
Alternative 3A
CroundMater Collection, On-Site
Treatment by Cascade Aeration 1
Discharge to Chippeua River via
Storm Sewer
Alternative 3B
Groundwater Collection, On-Site
Treatment by Air Stripper 1
Discharge to Chippeua River via
Storm Sewer
Implementabilfty
Technical Feasibility
Easily taplementftble. both
technically and administratively.
Availability of services and
materials
Administrative Feasibility
Installation of extraction wells,
groundwater capture, and
discharge to POIU present no
difficult technical problems.
Equipment, construction materials
and qualified personnel are
readily available.
Easements may be required for
pipe installation to off-site
sanitary seuer(s) if on-slte
severs don't provide sufficient
capacity. Extracted groundwater
must meet POTU acceptance limits
for contaminants of concern. Eau
Claire's unwillingness to accept
extracted groundwater renders
this alternative
unimplementable.
Installation of extraction wells,
groundwater capture, cascade
aeration system and pipe
installation from site to City of
Eau Claire storm sewer present no
difficult technical problems.
as Alternative 2
Easements may be required for
pipe Installation to off-site
storm sewer(s) if on-site sewers
don't provide sufficient
capacity. At a minimum,
substantive requirements of WPOES
permit for discharge to Chippewa
River must be met. Coordination
with and approval from the City
of Eau Claire are necessary.
Air stripping Is demonstrated
and proven technology.
Installation of extraction
wells, groundwater capture, and
pipe installation from site to
City of Eau Claire storm
sewer(s) present no difficult
technical problems.
Same as Alternative 2
Same as Alternative 3A
Cost
Capital cost
Annual OSM
rear t
Tears 2-30
30 year present worth
(10X discount rate)
There are no costs associated
with the No Action Alternative
1194,000
S1S6.000
$105,000
$1.23 HiIIion
$255,000
$163,000
$104,000
$1.29 Hi 11 ion
$336,000
$162,000
$124,000
$1.56 Hi I lion
-------
TABLE 6 CONTINUED
DETAILED EVALUATION OF REMEDIAL ALTERNATIVES
(Excluding State and Community Acceptance)
Evaluation Criteria
Alternative *A
Groundwater Collection, On-Sit«
Treatment by Cascade Aeration and
Discharge to Lake ttallie via
Installed Pipe
Alternative AB
Groundwater Collection, On-Site
Treatment by Air Stripper and
Discharge to Lake Hal lie via
installed Pipe.
Alternative 5
Grounduater Collection, On-Site
Treatment by Air Stripper and
Discharge to On-Site Groundwater
Recharge lagoons
Overall Protection of Hunan
Health and the Environment
Reduces potential risks fron
groundwater ingettion at source
areas. Mitigates degradation of
groundMater doMngradient of
source areas and prevents off-
site movement of contaminant
plume* through collection at the
source areas, on-site treatment
and discharge to Lake Hal lie.
Does not address off-site
contaminated groundwater or on-
site sources of contamination.
Sane a» Alternative 4A
Reduce* potential risks from
groundwater incestton at source
areas. Mitigates degradation of
grounduater downgradient of
source areas and prevents off-
site movement of contaminant
plumes through collection at
source areas, on-site treatment
and discharge to on-site
grounduater recharge lagoons.
Does not address off-site
groundwater contamination or on-
site source areas.
Compliance with State and
Federal Regulations (ARARs)
Same as Alternative 3A
In addition, potential impact of
constructing dedicated pipe to
the Chippewa River must be
evaluated and an permit may be
required.
Same as Alternative &A
Effluent standards Mill be net
for treated grounduater
discharged to the recharge
lagoons, although store stringent
Wisconsin PALs apply. Transfer
of VOCs from grounduater to air
will comply with ambient air
quality standards. Extraction
wells must comply with applicable/
state.codes regarding wall
construction and pump
installation. Long-tern cleanup
goals for groundwater are
Wisconsin PALS. New monitoring
veils would comply with Wisconsin
design, installation and
construction requirements.
Long-Term Effectiveness and
Permanence
Alone, does not provide adequate
long-term control of
contaminants. Source areas
continue to release contaminants
to soil and groundwater. Through
continued operation, interim
remedial action prevents off-site
movement of contaminated
groundwater from on-site source
areas, and may achieve
groundwater cleanup goals over
an extended time frame with
adequate source control. Long-
term management includes;
monitoring quality of water ••
extracted, in-ground and prior to
discharge to Chippewa River, and
routine maintenance.
Same as Alternative 4A
as Alternative 4A
-------
Reductlon.of TO.iClty,
Mobil I ty Ind \/olua
EVlluation Criteril
Short-T- Effecti-s
Protection of COllllUlity ci.lring
r-aial action
Protection of MOrters ci.lring
r8ll8Cliai ection
Time until r-Cial objectives
are achieved
I~l_tlbi I ity
Technical F...ibi Ii ty
AVlillbii Ity of services Ind
material.
Aaninistrative Fusibi I ity
Cost
Cepltal cost
Annua I 0&11
Yelr 1
Yelrs 2.10
10 year present worth
(10% discount rite)
Same as Alternative 1
Al ternative 4A
Groundwater Collection, On'Site
Treatment by Cascade Aerltion and
Discharge to Lake Hillie via
Installed Ph..
No risk to cClllllUlity as all
e.trlction wlls lIQUid be
installed on-site end
cont8lllinated groundwater -..Id be
discharged, following on-site
treatment, to lake Hall ie. \IOC
emissions from cascade aerltion
would comply with lIIiIient lir
qual ity standards. Some
di sruption to cOftllUli ty and
normal traffic patterns will
likely occur during installation
of main from the site to Lake
Hillie, a distlnce of
appro.ilNltely 1 mile.
Same IS Alternative 3A
Same as Alternative 2
Installition of euraction wlls,
groundwater clpture, construction
of CISCade urltion system Ind
pipe installation from Site to
Like Hall ie present no dlfficul t
technical problems. Boring and
jlck ing wi II be requi red to cross
I railroad and several roads and
highways.
Same IS Alternative 2
Easements or access agr.-u
wi II Ii kel y be requi red to
instill pipe from the Site to
lake Hall i e. At a mini_,
substlntive requirements of WPDES
permit for discharge to like
Hill ie IlUSt be met.
5510,000
5200,000
5142,000
51.9 Million
S- IS Alternative 1
Alternative 4B
Groundwater Collect ion, On-si te
Treatment by Air Stripper Ind
Discharge to Lake Hillie vii
Insulled Pipe
No ri sts to cClllllUli ty as all
extrlction wlls -..ld be
installed on site Ind
cont8lllinated groundwater -..Id be
dischlrged, following on-site
treatment to Lite Hall ie. \IOC
emissions frOll lir stripping
NOUld comply with ambient air
quality standards. S-
disruption to cClllllUlity and
nonaal trlffic patterns wi II
likely occur during instillation
of lNIi" from the site to Lake
Hillie, a distance of
aPProxi..tely 1 IIi Ie.
Same IS Alternative 3A
Same IS Alternative 2
Air stripping is demonstrated and
proven technology. Instillation
of e.traction wlls, groundwater
capture, construct i on of ai r
stripper Ind pipe installation
from to lake Hallie present no
difficult technical problems.
Boring and jacking will be
requi red to cross a railroad Ind
several roads and highways.
Same as Alternative Z
Same as Alternative ""
-
-
.~'":
5572,000
5216,000
51"",000
52 Mill ion
S- as Alternative 1
Al ternative 5
Groundwater Collection, On'Site
Trutment by Air Stripper &
Discharge to On-site Groundwater
Recharoe lagoons
No risks to c-..aity as all
extraction wells -..Id be
instilled on site. Any YOC
emissions fr08 air stripper -..Id
comply with _ient air qual ity
standards. Air stripper -..ld be
constructed on si te ...ay from
residential areas 8nd Ictive
areas of NPI Site. Groundwlter
rechlrge lagoons Ire Ilso loclted
on site and IWlY from surrounding
cCllllUli ty. Ind active ereas of the
Site.
Same a. Alternative 3A
Same IS Alternative 2
Air stripping Is demonstrated end
proven technology. Installation
of extrlction wlls, groundwlter
capture, construction of air
stripper, and pipe instlllition
to on-site rechlrge llgoons
present no difficul t technical
probl ecns.
S- as At ternative 2
Aani"istratively, easy to
i~lement as III c_ts of
remedial action Ire conducted on
site. At a minimun, substlntive
requi rementS of WPDES permi t for
discharge of treated groundwater
to on-site recharge lagoons Nst
be met.
5373,000
5186,000
5125,000
51.61 Million
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22
1.
Overall Protection of Human Health and the Environment
Alternative 1 does not address current and future potential health
risks or environmental degradation attributable to contamination of
groundwater from on-site source areas. In the absence of any
controls, groundwater containing VOCs above health-based levels,
and MCLs and wisconsin ESs would continue to migrate unimpeded off
site. Because the No Action Alternative does not satisfy this
threshold criterion of protection of human health and the
environment, it is eliminated from further consideration.
Under the remaining alternatives, off-site movement of contaminated
groundwater would be prevented through the placement of extraction
wells at and immediately downgradient of the Melby Road Disposal
Area and Lagoon No.1 and Ditch No.3 in the southwestern portion
of the site. Alternatives 2, 3A, 3B, 4A, 4B and 5 employ the same
series of groundwater extraction wells; however, treatment options
between the alternatives vary. con~aminated groundwater would be
captured at the source areas and degradation would be reduced
downgradient 0"£ the source areas. until implementation of the
alternate drinking water supplies for the affected area is
completed, contaminated groundwater continues to pose potential
risks to human health under existing area drinking water supply
conditions. Frequent monitoring will be conducted to ensure
contaminant plume capture and continued protection of human health
and the environment at and beyond source areaso. It is emphasized
that this interim remedial action does not address off-site
groundwater contamination or on-site waste areas and contaminated
soils.
2.
comDliance with ARABs
As an interim action, pursuant to the NCP, a limited number of
ARARs apply. The objective of this interim action is plume
containment by means of groundwater extraction and treatment at the
Melby Road Disposal Area and the so8thwestern portion of the site.
Long-term cleanup goals for groundwater are the wisconsin PALs,
which will be addressed in the final response action for the
Facility.
Chapter NR 140, WAC, establishes the range of response actions the
State may require if a groundwater enforcement &tandard is attained
or exceeded, and is applicable to this interim action. TCE, TCA
and PCE are present above Wisconsin ESs in on-site monitoring wells
at the Melby Road Disposal Area and the southwestern portion of the
site. .
Technology-based or water quality-based effluent limitations can be
met by all the alternatives, with the exception of the No Action
Alternative. Requirements for discharge of treated contaminated
groundwater to the Chippewa River (Alternatives 3A and 3B) or Lake
Hallie (Alternatives 4A and 4B) include water quality-based limits
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23
and recommendations specified by WDNR in accordance with Chapters
NR 102, 104, 105, 106 and 207, WAC. Any BAT achievable limits and
requirements as determined by WDNR in accordance with Chapter
NR 220, WAC must also be satisfied. The more stringent of either
the water-quality based limits or the BAT requirements are
applicable. Bioassays may be required.
Chapter NR 112, WAC, establishes uniform and minimum standards for
the construction and maintenance of high capacity water systems
which will apply to the groundwater extraction system under each of
the alternatives.
Chapter NR 141, WAC, establishes minimum design, installation and
construction standards for groundwater monitoring wells and would
apply to the long-term monitoring program associated with each of
the alternatives.
As an off-site action, a WPDES permit would be required for
discharge of treated groundwater to the Chippewa River
(Alternatives.3A and 3B) or Lake Hallie (Alternatives 4A and 4B).
WPDES general permits specify a limit of 0.1 ug/l (ppb) for
polynuclear aromatic hydrocarbons. If that number is exceeded in
the effluent, a specific permit would be required which generally
takes more time to issue than a general permit. For discharges to
groundwater (Alternative 5), treated effluent should be either at
or below NR 140 PALs or meet BAT, whichever is the more
restrictive. .
Under Alternatives 4A and 4B, installation of dedicated piping from
the Site to Lake Hallie or the Chippewa River would comply with
Chapter 30, Wisconsin Statutes; which specifies permit requirements
for new construction which may impact navigable waters in the State
of Wisconsin.
Based on observed concentrations of contaminants in groundwater and
expected removal efficiencies thro~h treatment by either cascade
aeration or air stripping, air enfissions would comply with the
Wisconsin I S air quality standards for hazardous pollutants pursuant
to Chapter NR 445, WAC.
Under Alternative 2, extracted groundwater discharged to the Eau
Claire POTW would comply with local influent. limits established
under Eau Claire I s pretreatment program. The City of Eau Claire is
responsible for implementing a pretreatment program in accordance
with 40 CFR Part 403 of the Clean Water Act. The pretreatment
program requires a municipality to establish numerical limits for
discharges into the POTW from users of the system. These limits
would apply to contaminated groundwater discharged directly to a
sanitary sewer and determine the need for any pretreatment.
(Any future off-site remedy(ies)
policy regarding remedies.)
would comply with U. s.
EPA's
-------
24
B.
PrimarY Balancina criteria
Five primary balancing criteria are use~ to identify major trade-
offs between the remedial alternatives which satisfy the two
threshold criteria. These trade-offs are ultimately balanced to
identify the preferred alternative and to select the final remedy.
L
Lona-Term Effectiveness and Permanence
Within the limited scope of this interim remedial action, a
properly designed and operated extraction system, as provided by
the remaining alternatives, would prevent off-site movement of
contaminated groundwater indefinitely from the Melby Road Disposal
Area and the southwestern portion of the Site. Groundwater cleanup
goals may be achieved at and beyond source areas over an extended
period of time; however source areas remain on Site and
contaminated groundwater off site would not be captured by the
extraction system. This interim action, in conjunction with a
final cleanup plan for the site that addresses source areas and
off-site groundwater, would offer long-term effectiveness and
permanence. .
2.
Reduction in Toxicitv. Mobilitv or Volume
Because this action does not constitute the final remedy for the
Facility, the statutory preference for remedies that employ
treatment that reduces toxicity, mobility, or volume as a principle
element will be addressed by the final response action. This
interim action does not significantly reduce the toxicity, mobility
or volume of hazardous substances at the Facility.
3.
Short-Term Effectiveness -
Each of the alternatives is expected to be protective of the
community and site workers during construction, implementation and
operation of the remedial action. '"'=-
During the installation of the groundwater extraction wells,
workers must comply with the approved health and safety plan for
the Site to minimize potential exposure to site contaminants. All
extraction wells will be located on site and pose no risk to the
community during installation. For the remaining components of
Alternatives 2, 3A, 3B 4A, 4B and 5, workers will be subject to the
normal and customary risks associated with construction, but to
varying degrees for each of the alternatives. Alternatives 4A and
4B require the greatest amount of construction and potential
disruption to the communi ty due to the installation of
-approximately one mile of underground pipe from the site to Lake
Hallie.
ImplementCition of Alternative 2 would require the installation of
approximately 1,600 feet of pipe. from the source areas to the
-------
25
nearest sanitary sewer lines, which are located on site. storm
sewers required for the implementation of Alternatives 3A and 3B
are also located on site and would require installing approximately
2,100 feet of pipe between the respecti ve extraction systems,
treatment systems and storm sewers. It is assumed that these
sanitary sewers and storm sewers will be of sufficient size to
adequately receive and transport the collected groundwater from the
extraction system. If additional off-site sanitary and/or storm
sewer capacity is needed, some disruption to the community may
occur during the process of obtaining access to the sewers.
Through treatment of groundwater under Alternatives 3A, 3B and 4A,
4B and 5, VOCs will be released to the air. Based on VOC
concentrations in groundwater and estimated removal efficiencies of
either cascade aeration or air stripping, VOC emissions to the
atmosphere would comply with ambient air quality standards.
Furthermore, on-site treatment systems would be located away from
the surrounding community and active areas of the NPI Site.
The remedial. objective for this interim--action is to prevent the
off-site movement of contaminated groundwater from the Melby Road
Disposal Area and southwestern portions of the Si te.
Implementation of any of the alternatives will accomplish this
objective once a sufficient capture zone has been established and
maintained by pumping the extraction wells.
None of the alternatives is expected to have adverse environmental
impacts. There is a potential impact associated with discharging
water to the Chippewa River or Lake Hallie. This potential is
mitigated with treatment of the extracted groundwater prior to
discharge, provided the treatment system is maintained in proper
working condition and is in compliance with discharge limits.
Effluent limits required by WDNR are designed to protect aquatic
life in the river and monitoring will verify compliance with
discharge limits. Discharge of untreated groundwater to the Eau
Claire POTW would require compliance with influent limits
established by Eau Claire's pretreatment program.
4.
ImDlementability
Technically, all of the al ternati ves are easi ly implementable.
Materials and services required to install groundwater extraction
systems, construct. an air stripping tower or cascade aeration
system and install the necessary piping to the point of discharge
are widely and readily available. Implementation of Alternatives
4A and 4B would require boring and jacking to install piping from
the site to Lake Hallie as the pipe would cross a railroad, highway
and several local roads.
The length of operation of any of the alternatives is difficult to
predict until performance. is measured and evaluated. Therefore,
routine maintenance by qualified personnel will be necessary.
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26
Alternatives 2, 3A and 3B present potentially significant
administrative obstacles to implementation. The city of Eau Claire
imposed several conditions for POTW acceptance of groundwater
extracted during the aquifer pumping test conducted by NPI in mid-
July 1991. The City has also determined that it is unable to
accept extracted groundwater for treatment at its POTW on a long-
term basis. For this reason Alternative 2 is eliminated from
, further consideration.
The use of Eau Claire storm sewers to transport treated groundwater.
to the Chippewa River will require coordination with and approval
from the City. Before the City can make a final decision, it
requested that NPI provide information on flow rates, the point of
discharge to the storm sewer(s),.- and how the system will be
designed to shut down during periods of heavy flow in the storm
sewers. Any restrictions or conditions imposed by Eau Claire must
not impact implementation in a manner that jeopardizes achievement
of remedial action objectives. correspondence between NPI and the
City indicates the likelihood of a favorable resolution to the
City's concerns. The City has requested that the extraction system
be designed to. shut down during heavy precipitation when the storm
sewers reach capacity from storm runoff. Such safeguards can
easily be incorporated into the design of the extraction system.
Administrative issues must also be resolved before Alternatives 4A
and 4B would be implemented. The installation of pipe fr9m the
site to Lake Hallie would require access agreements with property
owners, public and private, and/or purchase of land. This may take
some effort to arrange or. may render this al ternati ve
unimplementable.
5.
Cost
Each of the alternatives have the ability to achieve the objectives
of this interim action with proper construction, implementation,
and operation and maintenance. Th~re are common elements to all
the alternatives which include extraction wells and pumps, piping
to point(s) of treatment and discharge, and long-term monitoring.
variations in treatment methodologies and operation and maintenance
requirements account for the cost ranges between the alternatives.
Alternatives 4A and 4B have the highest estimated construction
costs ($510,000 and $572,000, respectively) which is attributable
to the costs associated with laying pipe from the NPI Site to the
Lake Hallie discharge point. The cost of the air stripping tower
is reflected in the slightly higher construction costs for
Alternative 4B. operation and maintenance costs are also slightly
higher than the other alternatives and is due to the added
requirements for maintaining the system between the site and Lake
Hallie. As a general note of comparison, all alternatives
involving air stripping require more operation and maintenance than
the less complicated cascade aeration treatment system.
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27
Alternative 5 is the next costly alternative to implement with
construction costs of $373,000. This is primarily due to the extra
piping required to transport extracted groundwater from the Melby
Road Disposal Area and southwestern portion of the Site to the air
stripper which would be located in the central portion of the Site.
Again, slighter higher operation and maintenance costs reflect the
use of an air stripper as opposed to cascade aeration.
With the exception of the transport mechanism following treatment
of extracted groundwater and the receiving water body, Alternatives
3A and 3B are identical to Alternatives 4A and 4B. Alternative 3A
and 3B will utilize the existing City of Eau Claire storm sewer
network to transport treated groundwater to the Chippewa River.
This accounts for the lower construction costs, $255,000 and
$336,000 for Alternatives 3A and 3B, respectively, when compared to
Alternatives 4A and 4B. Similarly, operation and maintenance costs
are somewhat less.
With the exception of the No Action Alternative, Alternative 2 is
the least costly to implement ($194,000) and operate and maintain
because it uses Eau Claire's POTW for treatment of extracted
groundwater. However, this al ternati ve is not implementable
because of Eau Claire's unwillingness to accept extracted
groundwater for treatment in its POTW.
c.
Ko4ifvina criteria
1.
State Acceptance
The State of Wisconsin has been an active and supporting
participant in the remedial process for this Facility. The State
is a signatory to the RIfFS Consent Order with NPI and has
supported past remedial and enforcement decisions concern~H,7 the
Facili ty. As the support agency, the WDNR concurs wi th the
selected remedy for this interim action.
2.
Community AcceDtance
"''::'
Section XI of this ROD is the Responsiveness Summary which presents
background information on community involvement and categorizes the
public comments received during the public comment period and U.S.
EPA's responses to the comments. .
IX.
THE SELECTED REMEDY
Section 121 of CERCLA requires that all remedies for Superfund
sites be protective of human health and the environment, comply
with ARARs, be cost-effective, and utilize permanent solutions and
al ternate treatment technologies to the maximum extent practicable.
U.S. EPA and the State, of Wisconsin believe Alternative' 3A
represents the best balance of tradeoffs among the alternatives
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28
evaluated for this interim action pursuant to applicable NCP
criteria. This interim action is protective of human health and
the environment, complies with Federal and state ARARs for this
limi ted-scope action, and is cost effective. This action is
interim and is not intended to utilize permanent solutions and
alternative treatment technologies to the maximum extent
practicable. Because this action does not constitute the final
remedy for the Facility, the statutory preference for treatment
that reduces toxicity, mobility or volume as a principal element
will be addressed by the final response action.
The selected remedy for this interim action entails:
* Installation and operation 6f groundwater extraction wells
at the Melby Road Disposal Area and the southwestern portion
of the site downgradient of Lagoon No. and Ditch No.3;
* Treatment of extracted groundwater by two independent
cascade aeration units comprising a 9-foot concrete step
structure constructed on site;
* Discharge of treated groundwater to the City of Eau Claire
storm sewer system for transport to the Chippewa River;
* Long-term monitoring; and
* provision for installation of dedicated.pipe between the
site and Lake Hallie or the Chippewa River should continued
use of the City of Eau Claire storm sewer system be
precluded.
Aquifer pumping tests were conducted at the Melby Road Disposal
Area during the period of July 16 through July 19, 1991 for
purposes of evaluating aquifer conditions and to demonstrate
groundwater capture parameters during short-term pumping
conditions. The two existing s-incl1 wells were used as the pumping
wells and nearby monitoring well~ served as observation wells
during and following the pumping tests. All extracted groundwater
was discharged to a City of Eau Claire sanitary sewer located on-
site.
The Melby Road Disposal Area is underlain by approximately 100 feet
of glacial outwash consisting of sand with .varying amounts of
gravel. The lower 30 percent of the sand and gravel is
characterized by unconfined water table conditions.
Three separate tests were conducted over the four days and the data
and summary report are included in the administrative record. The
most critical test involved the pumping of both 5-inch wells at 90
gpm each for six hours. ~he results indicated that the two wells
produced a combined capture zone at least 400 feet wide. The
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continued drawdown in an observation well located equidistant
between the pumping wells ipdicated that the ca~ture zone was
continuing to increase.
The placement and proposed pumping rates of the extraction wells at
the Melby Road Disposal Area are expected to provide a sufficient
capture zone to prevent off-site movement of contaminated
groundwater from this source area. An additional two or three 5-
to a-inch extraction wells would be installed at the southwestern
portion of the Site to ensure contaminant plume capture in this
portion of the Site. Total groundwater pumping rates between the
two independent extraction systems are expected to be 400-500 gpm.
Once remedial action is implemented, an aquifer pumping test will
be conducted at each extraction system to verify assumptions made
during remedial design regarding extraction well placement and
proposed pumping rates. The test will also determine if system
performance is consistent with the remedial action objective of
preventing the off-site movement of contaminated groundwater. If
necessary, modifications to the extraction system will be made at
this time. .
RecoveLed groundwater from the Melby Road Disposal Area would be
pumped approximately 1500 feet to a cascade aeration unit. The
treated groundwater would then be discharged to an existing 12-inch
City of Eau Claire storm sewer located on site. Recovered
groundwater from the southwestern portion of. the Site would be
pumped approximately 600 feet to a second cascade aeration
structure and discharged to an existing 24-inch City storm sewer,
also located on site. Both storm sewers would then transport
treated groundwater to the Chippewa River. Discharge to the
Chippewa Ri ver would comply wi th- the condi tions and reporting
requirements of a WPDES permit.
Long-term monitoring would be required to measure progress and
performance of the groundwater extraction and treatment system,
verify completeness of contaminan~ plume capture, determine the
need for additional treatment of extracted groundwater and monitor
compliance with WPDES permit requirements for discharge of treated
groundwater to the Chippewa River.
Additional monitoring wells would be installed at the Melby Road
Disposal Area and the southwestern portion of-the Site to satisfy
long-term monitoring requirements. During remedial design and upon
implemp.ntation of remedial action, groundwater would be analyzed
for U.S. EPA's TCL and TAL parameters for purposes of determining
the need for additional treatment of contaminated groundwater.
Selected groundwater monitoring wells will also be analyzed for
VOCs to evaluate the impact of plume containment-on downgradient
groundwater quality and collect data in support of the final
response action for contaminated groundwater for the Facility. The
final monitoring program, including number of samples, frequency of
sampling, and analytical parameters will be approved by U.S. EPA as
-
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30
part of the remedial design for this interim action, and may be
modified, as appropriate, during remedial action.
It is recognized that the city of Eau Claire may withdraw
permission to use its storm sewer or , i~ response to heavy
precipitation, require frequent and/or extended shutdown of the
groundwater extraction system. Either of the above situations
would jeopardize the ability of this interim action to prevent the
off-site movement of contaminated groundwater. To ensure
continuation of the remedial action consistent with the role and
scope of this interim action, u.s. EPA would require the
installation of a dedicated pipeline to either Lake Hallie or the
Chippewa River.
x.
STATUTORY DETERMINATIONS
The selected remedy for this interim action meets the statutory
requirements, as determined to be applicable to this interim
action, set forth in section 121 of CERCLA. Pursuant to section
121(a-e) ofCERCLA, the selected remedy must protect human health
and the environment, comply with ARARs, be cost effective, utilize
permanent solutions and alternate treatment technologies to the
maximum extent. practicable and satisfy a preference for treatment
as a principal element of the remedy.
The implementation of Alternative 3A satisfies those statutory
requirements that are applicable to this interim action for the
Facility.
A.
Protection of Human Health and the Environment
The selected remedy reduces potential risks from groundwater
ingestion at on-site sources; however, contaminated groundwater
does not pose potential health risks under existing area drinking
water supply conditions. This interim action mitigates degradation
of groundwater at and immediately downgradient of source areas and
prevents off-site movement by mearm of plume containment. 'This
interim' action does not address off-site contaminated groundwater
or on-site source areas. .
B.
ComDlianc8 with ARARs
The selected remedy for this interim action. will comply with
Federal, or more stringent State, applicable or relevant and
appropriate requirements (ARARs) listed below.
1.
Chemical-SDecific ARARs
Chemical-specific ARARs include those laws and requirements that
regulate the release of contaminants to the environment. These
includp.:
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31
a. Federal ARARs
Section 304 of the Clean Water Act (CWA) establishes Ambient Water
Quality Criteria (AWQC) for protection of human health and aquatic
life. The AWQC are considered relevant and appropriate at
Superfund sites where a release or the threat of a release is
present or when remedial actions require point source discharges to
surface water bodies. Since treated groundwater will be discharged
to the Chippewa River, AWQC are relevant and appropriate for the
discharge.
b.
State ARARs
Chapter NR 105 WAC, Surface Water Quality Criteria for Toxic
Substances, establishes water quality criteria and methods for
developing criteria for toxic substances to protect surface waters
in the State of Wisconsin. Wisconsin water quality criteria are a
component of surface water quality standards and are applicable to
the discharge of treated groundwater to the Chippewa River and its
potential impact on surface water quality.
Chapter NR 106 WAC, Procedures for Calculating Water Quality Based
Effluent Limitations for Toxic and organoleptic Substances
Discharged to Surface Water, specifies methods for calculating
water quality based effluent limitations and how these limitations
will be included in WPDES permits. -
Chapter NR 102, WAC, Water Quality Standards for Wisconsin Surface
Waters and Chapter NR 104, WAC, Intrastate Waters-Uses and
Designated Standards, designate the uses for which the various
waters of Wisconsin shall be maintained and protected. These
chapters prescribe the water quality required to sustain the
designated uses and indicate methods to implement, achieve, and
maintain water quality. Chapters NR 102, 104 and 105, WAC
constitute quality standards for the surface waters of Wisconsin.
2.
Location-SDecific ARARS
~
Location-specific ARARs are those requirements that relate to the
geographical location of a site. No location-specific ARARs have
been identified for this interim action.-
3.
Action-Specific ARARs
Action-specific ARARs are requirements that define acceptable
treatment and disposal procedures for hazardous substances. These
include:
a. Federal ARARs
Treatment of extracted groundwater prior to discharge to surface
water is an ARAR. Section 301(b) (2) of the CWA requires
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32
.,
"application of the best available technology (BAT) economically
and technologically achievable for purpose of achieving the
"national goal of eliminating the discharge of all pollutants...."
section 402 (a) (1) of the cWA provides for the issuance of a
National Pollutant Discharge Elimination System (NPDES) Permit for
the discharge of any pollutant to surface water bodies.
(Any future off-site remedy (ies) would comply with u.S.
policy concerning off-site remedies.)
EPA's
b.
State ARARs
In addition to establishing groundwater quality standards for
substances in groundwater, Chapter NR 140, WAC, Groundwater
Quality, establishes ranges of responses the state may require if
a groundwater ES is attained or exceeded. The exceedence of ESs
for TCE, TCA and PCE in on-site monitoring wells trigger the
action-specific requirements of Chapter NR 140, WAC.
The State of. Wisconsin is authorized to implement the NPDES
program. For discharge of treated groundwater, the ARARs are
dependent on the point of discharge. Since the point of discharge
is the Chippewa River, which is off-site, a WPDES permit would be
required pursuant to Chapter 147, Wisconsin statutes.
The BAT requirements of the CWA are determined by the State on a
case-by-case basis pursuant to Chapter NR 220, -WAC. The need for
specific BAT requirements is determined based on an evaluation of
water quality based limits and on an evaluation of projections of
effluent quality and pollutant removal efficiencies for a proposed
groundwater treatment system. WDNR has determined that cascade
aeration, as specified by the selected remedy, satisfies the BAT
requirements of the CWA and Chapter NR 220, WAC.
Chapter NR 445, WAC, Control of Hazardous Pollutants, regulates air
emissions from treatment technologies and establishes emission rate
limits for specific substances. Sii1l::e VOCs will be emitted through
treatment of extracted groundwater by cascade aeration, Chapter NR
445, WAC is an. ARAR. If cascade aeration emissions exceed
standards, then emission control will be included in the treatment
system to bring air emissions into compliance. However,
conservative estimated emission rates from cascade aeration, based
on maximum observed VOC concentrations in groundwater and the
projected VOC removal efficiency of cascade aeration, are well
within identified limits.
v
Chapter NR 112 ,WAC, Well Construction and Pump Installation,
establishes uniform and minimum standards for the construction and
maintenance of high capacity water systems and are applicable to
the groundwater extraction system.
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33
Chapter NR 141, WAC, Groundwater Monitoring Well Requirements,
establishes minimum acceptable standards for the design,
installation, construction, abandonment and documentation of
groundwater monitoring wells, and are applicable to the monitoring
wells installed as part of the long-term monitoring program.
Cost Effectiveness
C.
Cost-effectiveness compares the effectiveness'of an alternative in
relation to its cost of protecting human health and the
environment. With the exception of Alternative 2, which is not
implementable, the selected remedy is the least costly alternative
that satisfies the objectives of this interim action. It provides
for an appropriate level of treatment of extracted groundwater that
satisfies the BAT requirements of Wisconsin regulations and
utilizes the existing city of Eau Claire storm sewer network to
transport treated groundwater to the Chippewa River.
D.
utilization of Permanent Solutions and Alternate Treatment
Technoloqies to the Maximum Extent Practicable
This action is interim and is not intended to utilize permanent
solutions and alternative treatment technologies to the maximum
extent practicable for this operable unit. The selected remedy
represents the best balance of tradeoffs among alternatives with
respect to pertinent criteria, given the limited scope of the
action.
E.
Preference for Treatment as a PrinciDal Element
Because this action does not constitute the final remedy for the
Facility, the statutory preference for remedies that employ
treatment that reduces toxicity, mobility or volume as a principal
element will be addressed by the final response action.
XI.
RESPONSIVENESS SUMMARY
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~..:
A.
Introduction
This Responsiveness Summary .has been prepared to meet the
requirements of Sections 113(k) (2) (B) (iv) and 117(b) of the
Comprehensive Environmental Response, Compensation and Liability
Act of 1980, as amended by the Superfund Amendments and
Reauthorization Act of 1986 (CERCLA), which requires the U.S. EPA
to respond ".. .to each of the significant comments, criticisms, and
new data submitted in written or oral presentations" on a Proposed
Plan for remedial action. This Responsiveness Summary summarizes
comments and concerns expressed by the public and other interested
parties in the written and oral comments received by U.S. EPA on
the preferred remedy for this interim action Facility.
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State of Wisconsin \ DEPARTMENT OF NATURAL RESOURCES
<.
Carroll D. Besadny, Sec:retary
BoJC 7921
Madi/Son, Wi/Sc:on/Sin 53707
DNR TELEFAX NO. 608-267-3579
TOO NO. 608-267-6897
SOUD WASTE TELEFAX NO. 608-267-2768
September 26, 1991
FILE REF:
National Presto Inc.
Mr. Valdas Adamkus, Regional Administrator
U. S. Environmental Protection Agency
230 South Dearborn Street
Chicago, IL 60604
SUBJECT:
Selected Superfund Remedy
National Presto Industries
Eau Claire, WI
Dear Mr. Adamkus:
The Department is providing you with this letter to document the State or
Wisconsin's concurrence on the proposed interim remedy (ground water pump and
treat) for the 'National Presto Industries (NPI) Site. The proposal as
identified in the draft Record of Decision includes the'following:
Alternative 3A -
Ground water collection, On-Site Treatment by Cascade
Aeration and Discharge to the Chippewa River via Storm
Sewer.
Contaminated ground water will be captured by a series of ground water
extraction wells located at the northern property boundary of the NPI
Site at the Melby Road Disposal Site and in the southwestern portion of
the Site downgradient of Lagoon 1 ~d Drainage Ditch No.2. Extracted
water would be treated in a cascade aeration system and discharged to
the Chippewa River via City of Eau Claire storm sewer.
Due to the City of Eau Claire's condition that they have the ability to
.. . shut d~wn- the pump..and trealsystem .durjng periods of high flow in the
storm sewer system, the Department requires that a contingency for NPI
to construct a dedicated storm sewer to Lake Hallie or the Chippewa
River be added to the selected remedy to ensure the effectiveness of the
remedy should interruptions in Eau Claire storm sewer usage prove too
lengthy' for effective operation of the system.
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Mr. Valdas Adamkus
September 26, 1991
2
'"
Estimated Costs:
Capital costs S255,000. Operation and maintenance
costs $163,000 for the first year and S104,000 for
each year thereafter. . The thirty year present worth
for alternative 3A would equal approximately Sl.29
million. If additional treatment of contaminated
groundwater is required and lor there is a need to
construct a dedicated sewer line to Lake Hallie or the
Chippewa River, both capital costs and yearly
operation and maintenance costs will increase.
c;
The State of Wisconsjn will contribute 10 percent of the remedial action costs
associated with the National Presto Inc. interim remedy if the potentially
responsible parties (PRPs) do not agree to fund the selected remedy. This
assurance is provided on the condition that the U.S". EPA will pursue legal
actions against the PRPs, to the extent feasible. The State's preferred
enforcement approach is for U.S. EPA to negotiate a consent decree, or if
necessary, issue a unilateral order to the PRPs requiring them to undertake
the remedial design and remedial action of the selected interim remedy.
We also understand" that our staff will continue to work in close consultation
with your staff during the remaining Remedial Investigation/Feasibility Study
work associated with the NPI Site as well as during the design and
~onstruction of the interim remedy.
Thank you for your support and cooperation in addressing this contamination
problem at the NPI Site in Eau Claire and the Town of Hallie. If you have any
questions regarding this matter, please contact Mr. Paul Didier. Directcr cf
the Bureau of Solid and Hazardous Waste Management.
Sincerely,
c~
Secretary" -". 1- .
~
c:
Lyman Wible - AD/5
..Linda Meyer - LC/S
Paul Didier - SW/3
Dave Lundberg - WD
John Paddock - WD
Jim Boettcher - WD
Mike Gifford - EPA Reg. V (5HS11)
Mark Giesfeldt/Sue Bangert..- SW/3
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