PB94-964141
EPA/ROD/R05-94/268
April 1995
EPA Superfund
Record of Decision:
Ritari Post & Pole
(O.U. 1), Sebeka, MN
6/30/1994
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DECLARA nON FOR THE
RECORD OF DECISION
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SITE NAME A~1) LOCATION
RlT ARI POST A. 'ill POLE SITE.
MEADOW TO\VNSHIP. WADENA COUNTY. MINNESOTA
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action for the RIT ARI POST AND POLE SITE IN
MEADOW TOWNSHIP. WADENA COUNTY. MINNESOTA. chosen in accordance with the
~ Comprehensive Environmental Response. Compensation. and Liability Act of 1980 (CERCLA). as
amended by the Superfund Amendments and Reauthorization Act of 1986 (SARA), and. to the e:-.:tent
pracucable. the National Contmgency Plan (NCP). The decision is based on the Administrative Record
for the RIT ARI POST AND POLE SITE (Site). The attached index identifies the items which comprise
the admirusuauve record upon which the selection of the remedial action is based.
The state of Minnesota is the lead agency for this Site and has selected the remedy. The United States
Environmental Protection Agency (EPA) concurs with the selected remedy:
ASSESSMENT OF THE SITE
Actual or threatened .releases of hazardous substances from this Site. if not addressed by implementing the
response action selected in the Record of Decision (ROD). may present an imminent and substantial
endangerment to public health. welfare. or the enVIronment.
DESCRIPTION OF SELECTED REMEDY
The selected remedial action for the RIT ARI POST AND POLE Site addresses the source of the
contamination by remediation of soil. The major components of the selected remedial action include:
REMEDIAL ACTION COrvtPONENTS
*
Building and wood treating equipment decomanunation. dismantling or demolition and disposal.
*
Soil washing will be further investigated to detennine the overall cost and volume reduction of
TCDD-equivalent contaminated soils prior to off-site incineration.
*
Excavation and off-site treatment. via incineration. of approximately 1800 cubic yards of dioxin
contaminated soil.
*
Excavation. segregation and on-site treatment of approximately 5000 cubic yards of
pentachlorophenol contaminated soil.
*
Soil treatment cell monitoring program to confinn the adequacy of ex-situ bioremediation of
contaminated soils.
*
Once soil clean-up standards have been met. the soil treatment cells will be decommissioned.
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Topsoil cover and revegetation of remediated area.
Site deed restnctions that prevent mstallation of drinking water wells within the Site boundaries.
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Install deep aquifer well for Mrs. Ritan and completely fence working area of the Site to restrict
public access.
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Ground water monitoring program to ensure no migration of contaminants occurs at or beyond the
Site boundary. Additional monitoring wells will be added to the monitoring network to provide this
information. .
CONTINGENCIES
*
If after three years ofbiotreatment. the soil does not meet cleanup standards of 40 pans per million
(ppm) pentachlorophenol (PCP). then a contingent remedy of an approved cap will be installed over
the biotreatment area.
If additional ground water remedial measures are necessary. the contingency of installing two ground
water extraction wells will be implemented. The discharge water will be treated in a bioreactor.
carbon filtered. and then remfiltrated to the Site ground water sYStem upgradient of the eXtraction
wells.
*
The contingency ground water treatment remedy will be monitored and finally decommissioned once
the ground water clean-up goals have been achieved in the extraction wells.
The state of Minnesota and EP A have detennined the enhanced biological treatment of residually
contaminated soil is a viable innovative treatment technology for the PCP contaminated soils such as these
found at the Site. The enhanced biological treatment will be completely evaluated during remedial design
and shall provide for protection of public health and the environment within EPA's acceptable risk range
of 10E-4 to 10E-6. with a preferred point of departure of IOE-6 for potential carcinogens, and provide for
a cumulative health index less than one for noncarcinogens. If. based upon remedial design pilot studies.
EPA detennines that these health based goals are not achievable \'ia enhanced biological treatment, then
consolidation and capping the contaminated soils will be completed.
Excavation of the contaminated soils will reduce the potential for contaminants to move into the
underlying ground water. The contaminant concentrations should be greatly reduced after the source (the
contaminated soil) is removed. Long-term ground water monitoring will provide information about the
natural reduction of the ground water contaminants. The expanded monitoring well network will be used
to monitor and confirm this. This approach will be utilized in lieu of active ground water treatment
options.
ST A nrrORY DETERMINATIONS
Consistent with CERCLA as amended by SARA. 42 D.S.C. Section 9621. and to the extent practicable.
the NCP. 40 CFR Part 300. the selected remedy is protective of human health and the environment.
complies with federal and state requirements that are legally applicable or relevant and appropriate to the
remedial action. and is cost-effective. The remedy utilizes permanent solutions and alternative treatment
technologies to the maximum extent practicable at the Site. The remedy relies. in part. on institutional
controls to protect human health.
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The remedy will result in hazardous substances remaining on site in the ground water above health based
levels. A review of all Site conditions will be conducted within fi\'e years after commencement of
remedial action to ensure the remedy conunues to provide adequate protection of human health and the
environment. / /'/'
//~ /
./ ( :% / /'
// ~. ///l/J/Jt:~-
I ~/' t/" (/~~
''-erwles W Williams
Commissioner
Minnesota Pollution Control Agency
Il~/d Itt&?/
/ Valdas V. Adarnkus
t,- Regional Admimstrator .
L' U.S. Em1ronmental Protecuon Agency
~,//t'lqf
Date! (
-I/-
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SUMMARY OF REMEDIAL ALTERNATIVE SELECTION
RIT ART POST AND POLE SITE
MEADOW TOWNSHIP. W ADENA COUNTY. MINNESOTA
TABLE OF CONTENTS
1. SITE NAME. LOCATION AND DESCRIPTION
n.. SITE lllSTORY AND ENFORCEMENT ACTIVITIES
III. HIGHLIGHTS OF COMMUNITY PARTICIPATION
. a'.' ~.
IV. SCOPE AND ROLE OF REMEDIAL ACTIVITIES
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v.
SUMMARY OF SITE CHARACTERISTICS
. .
VI. SUMMARY OF SITE RISKS
VII. DESCRIPTIONS OF ALTERNATIVES
VIII. SUMMARY OF THE COMPARATIVE ANALYSIS OF AI.. TERNATIVES
IX. THE SELECTED REMEDY
X. STATIJTORY DETERMINATIONS SUMMARY
XI. RESPONSIVENESS SUMMARY
LIST OF EXHIBITS
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5
6
7
8
10
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19
24
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EXHIBIT 1 COST SUMMARY FOR SELECTED REMEDY AND CONTINGENCY: SOILS
EXHIBIT 2 COST SUMMARY FOR SELECTED REMEDY AND CONTINGENCY:
GROUND WATER
EXHIBIT 3 ADMINISTRATIVE RECORD INDEX
LIST OF FIGURES
FIGURE I-I SITE LOCATION MAP
FIGURE 1-2 AREA TOPOGRAPlllC MAP
FIGURE 1-3 OPERATIONS AREA MAP
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DECISION SUMMARY OF AI. TERNA TIVE SELECTION
RITARI POST .~'l) POLE SITE
MEADOW TOWNSHIP. W ADE~A COlJNTY. MINNESOTA
I. SITE NAME. LOCATION AND DESCRIPTION
The Ritari Post and Pole site (Site) is located in nonhwestem tl.1innesota. It lies within west central
Wadena County (population 13.130) and is approximately 3.5 miles northeast of the town of Sebeka
(Figure I-I). Sebeka is a community of about 775 residents. The Site is situated in a predominantly
wooded area. WIth limited agricultural operations. The affected area is located near the southwest comer
of a 212 acre tract of land owned by Mrs. Hazel Ritari. The wood treating and storage facility occupies
only about 10.25 acres of the Ritari property. The Site is bounded by County Road 143 on the south..
pasture on the west. and woods and pasture to the nonh and east (Figure 1-2).
Wood treating operations have occurred on the property from the mid-1950s to 1991. Original wood
treatment included the use of creosote. Later. operations were changed to pentachlorophenol (PCP)
treatment. Currently. no wood treating is occurring. although the retail sale of treated wood
continues.
The Site consists of several small sheds. above ground storage and treatment tanks. drip tracks. an office.
and two small depressions (Figure 1-3). The Site operauonal area can be subdivided into three areas:
treatment and sludge-drying. wood-stacking. and roadways (Figure 1- 3). Vegetated areas exist within
and surrounding the Site operation area and are areas of low/infrequent or no operational use.
II. SITE mSTORY AND ENFORCEMENT ACTIVITY
Mr. Melvin Ritari began wood treatment operations sometime between 1955 and 1957. Several
operational changes took place throughout the following years. The initial operation consisted of dipping
wood into holding tanks cont.3ining creosote and stacking the treated wood on the ground to dry. In 1959,
the treatment process changed to using a heavy oil-based PCP mixture. The heavy oil was mixed with
PCP in the PCP measuring tank and heated prior to being pumped into pressure tanks. Prior to 1973,
treated wood was allowed to drip onto the ground prior to being stacked to permit drying.
Beginning in 1973. treated wood was allowed to dry o\"emight in the pressure tank prior to being stacked
on the ground. In 1979. the treatment process was agam modified to use a water-based PCP miXture. The
water-based PCP treatment process included the bulk receipt of the product. which was transferred into
55-gallon drums prior to use. A vegetable oil was substituted for the heavy oil carrier in the water-based
PCP solution. Mixing and treatment operations were similar for both oil and water-based mixtures.
The Site owner and operator. Mr. Melvin Ritari died in May 1983. Following Mr. Melvin Ritari's death..
his son. Glenn. assumed operation of the Site. Wood treatment operation ceased in 1991, although the
sale of treated wood continues to date.
PCP sludge was generated as a result of the mixing and treatment operations. Approximately 150 gallons
of oil-based PCP sludge were estimated to have been generated each year. Water-based PCP sludge has
been generated at an estimated rate of 30 gallons or less per year. Sludge was removed from the tank once
or twice per year and spread on the ground to dry (see Figure 1-3 for location). According to Mr. Glenn
Ritari. some of the sludge was also sold or given to neighboring farmers as a wood treating solution.
In 1976. the Site was inspected by the Minnesota Pollution Control Agency (MPCA) and cited for
improper storage and disposal of sludge. In 1979. a complaint was filed with the MPCA by
Mr. Thurman Ratcliff regarding the potential PCP contamination of his well. In 1980. the MPCA
determined that the source of PCP in the Ratcliff well was probably due to the Ritari operation. This
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conclusion was based on the following factors: ground water flows from the Ritari propeny east toward
the Ratcliff property. Ritan was the only known regular user of PCP in the area. and the Ritan operation
had prevIously been cited for Improper storage and disposal of PCP sludge.
Because of the concern that soil contaminanon resulting from the treaunent operations could impact area
ground water. the Site was mspected. evaluated and scored by the U.S. Environmental Protection Agency
(EPA) in May 1985. The Site scored a 30 on the EPA's Hazard Ranking System and was formally placed
0!1 the federal National Priorities List (NFL) in 1985.
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On January 21. 1986. Glenn Ritari indicated that no cleanup progress had been made at the Site. A
Request for Response Action (RFRA) was issued by the MPCA on February 25. 1986. Due to lack of
financial resources. the MPCA issued a Determination of Inadequate Response (DIR). on April 22. 1986,
to allow the use of federal Superfund momes for a Site investigation and remediation. Glenn Ritari was
informed by the EP A on March 24, 1987. of his responsibility for soil and ground water contamination
present at the Site. EP A funded MPCA to conduct a remedial investigation and feasibility study (RIIFS)
at the Site via a Cooperative Assistance Grant (CAG). Delta Environmental Consultants. Inc. (Delta)
conducted an RI. for MPCA. at the Site from May 1990 to December 1992.
III. HIGHLIGHTS OF COMMUNITY PARTICIPATION
A fact sheet descnbing the ongoing RI was mailed to interested parties in November 1990. The MPCA
and the Minnesota Depanment of Health (MDH) then held a joint public meeting in the Sebeka City Hall
on November 19. 1990. to mform the citizens of the dioxin contamination found in four of the initial soil
samples collected as pan of sample collection tasks undertaken during the RI. Staff responded to
questions from those in anendance. No other questions from the public were received regarding the
dioxin issue. .
Following completion of the RI/FS, the MPCA published a Proposed Plan (PP) in the local newspaper on
January 19. 1994. describing the cleanup alternatives considered and proposing a cleanup plan for the soil
and ground water. A fact sheet containing the PP and notice of a public meeting to discuss the PP was
mailed to all interested parties. The MPCA held a public meeting in the Sebeka City Hall on February 1,
1994. At the public meeting, the MPCA staff presented the alternatives discussed in the PP and the
selected options. Following the presentation. staff responded to questions from the citizens in attendance.
The public cotnment period ended February 18. 1994.
A response to the cotnments received during this period is included in the Responsiveness Summary.
which is part of this. Record of Decision (ROD). This decision document presents the selected remedial
action for the Ritari Post and Pole Site. Meadow Township, Wadena County, Minnesota. chosen in
accordance with Comprehensive Environmental Response. Compensation. and Liability Act of 1980
(CERCLA), as amended by Superfund Amendments and Reauthorization Act of 1986 (SARA) and, to the
extent practicable. the National Contingency Plan (NCP). The decision for this Site is based on the
administrative record.
On December 21. 1993. Delta and the MPCA completed a Focused Feasibility Study (FFS) Report. which
detailed potential remedies for soil and ground water clean-up of the Site. The FFS Report analyzed the
feasibility and practicality of the potential options. From this analysis two remedies were identified as
potential clean-up options for the Site.
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IV. SCOPE AND ROLE OF REMEDIAL ACTIVITIES
Remedial Action Objectives
The Rl activities have characterized Site soils as a source of the contaminants of concern and identified
these contaminants. which exceed health critena. 111 shallow ground water at the Site. The contaminants
of concern for soil and ground water are PCP and polychlorinated dibenzo-p-dioxin-equivalent (TCDD-
cq).
The s01l source areas continue to have the potential to impact sediments. ground water. surface water and
alr. The situation mdicates a need to establish Remedial Action Objectives (RAOs) that are protective of
human health and the environment for the contaminated soil and ground water at this Site.
RAGs were not proposed for surface water. off-site sediments. or air. Surface water and off-site sediments
were not found to be impacted by the contaminants of concern at this Site at levels above human health
criteria. Air impacts were not directly characterized: however. potential impacts may occur due to wind-
blown dust. It is anticipated that remedial measures for soil and ground water (whIch are the sources for
impacts to surface water. off-site sediments. and air'! will alleviate continuing or potentiaI impacts to these
environmental media.
The RAOs are media-specific goals aimed at protecting human health and the enVIronment. They are
developed for site-specific conditions and take into account the exposure routes. receptors. the findings of
the chemical-specific human health assessments. and state and federal regulato!!' requirements. RAOs
developed for on-site soil and ground water are presented below.
Soil RAGs
The Rl concluded that exposure to contaminated soil on site could result in adverse. noncarcinogenic
health effects to humans (Le.. the PCP levels in Ritari soils are greater than the level at which daily
exposure is not likely to have a deleterious effect during a lifetime) and that exposure to TCDD-eq in Site
soils could result in carcinogenic risks of greater than 11.0E-3 (i.e., one person out of every 1,000 that are
exposed over a lifetime to the levels ofTCDD-eq found in Site soils is likely to develop cancer from this
exposure). The route of exposure resulting in the greatest risk is skin absorption. followed closely by
ingestion and lastly by inhalation of dust.
The soil RAOs specific to human e:-.:posure routes are:
*
MinimIze or prevent ingestion or direct contact with PCP-contaminated soil in excess of 0.03
milligrams PCPlkilogram body weight/day (mg/kg/day) (Ref Dose).
*
Minimize or prevent ingestion or direct contact with soil posing 1.0E-4 to 1.0E-6 excess cancer risk
from TCDD-eq and PCP.
*
Minimize or prevent inhalation of dust posing excess cancer risk levels of 1.0E-4 to 1.0E-6 from
TCDD-eq and PCP.
Using EPA's Risk Assessment Guidance for Superfund (RAGS), a soil clean-up criterion of 40 parts per
million (ppm) or milligrams/kilogram (mg/kg) was calculated for PCP. This clean-up number is based on
a risk level of 1.0E-5 for a residential scenario. The details of the assumptions and parameters used in the
RAGS equations is contained in the FFS Report. -
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A clean-up cntenon of I pan per billion (ppbl or mlcrogramlkilogram (ug/kg) for TCDD-eq 10 soil is
appropriate for a residential area. This is a health-based clean-up level based on calculations by the
Agency for Toxic Substance and Disease Registry (A TSDR) and the Centers for Disease Control (CDC).
Ground Water RAOs
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The RJ concluded that exposure to TCDD-eq 10 ground water does not pose elevated risks to current
ground water users. However. it was concluded that TCDD-eq levels of 0.009 to 0.018 part per trillion
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subsurface soils. as well as in the ground water. The contaminants of concern in the soils are: PCP.
polychlorinated dibenzodioxin and polychlorinated dibenzofurans. Concentrations of the vanous dioxins
and furans In soil and ground water have been convened into TCDD-eq. This conversion ranks all
dioxins and furans relative to the toxiciry of 2.3.7.8-tetrachIorodibenzodioxin. The contaminants of
concern in the ground water are also PCP and TCDD-eq.
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Polynuclear aromatic hydrocarbons (PAHs) were also found in samples collected at the Site. PAH
contamination appears widespread across the Site. however. the greatest carcinogenic risk to human
health at the Site appears to be due to the presence of PCP and TCDD-eq contaminants. It is anucipated
that remediation of PCP and TCDD-eq contamination will also mitigate P AHs. Therefore. no specific
clean-up criteria for P AHs have been calculated for the Site.
The nature and eXtent of the contamination at the Site. as identified in the RI. is described below.
I.
Soil
Soil samples collected during the RI indicate the highest level of contamination is present in surface
and subsurface soils in the viciniry of the treatment tanks. drip tracks. and the sludge drying area.
Soil discoloration and staining was also observed 10 these areas. ContaIIl1nant concentrations
. decrease in the wood-stacking areas and roadways. Vegetated areas have the lowest levels of
contamination.
The highest PCP concentrations were observed in the surface soils in the treatment area defined by
the above ground storage and treatment tanks. drip tracks. and sheds. The PCP concentrations in the
surface soils ranged from 25 to 12.000 mg/kg or ppm. Surface soils in the sludge drying area were
contaminated to the same degree as the surface soils in the treatment area (3100 to 5700 ppm).
Horizontally. the wood-stacking area and roadways were less contaminated than the treatment and
sludge drying areas (3.1 to 2600 ppm). The vegetated areas sampled had the greatest number of non-
detectable results and the lowest range of reported concentrations. up to 39 ppm. PCP concentrations
in the subsurface soils beneath the treatment and sludge drying area range from 12 to 970 ppm. Less
PCP contamination is present below five feet deep in the subsurface soils beneath the wood-stacking
and roadway areas. Generally the PCP soil concentrations were observed to decrease with depth at all
of these areas.
TCDD-eq contamination is associated with the PCP contamination in the soil. The TCDD-eq
contaminant panerns. horizontally and vertically. correlate with the PCP panerns: however. the
TCDD-eq concentrations are lower. reported in micrograms per kilogram or part per billion (ppb).
The follo\\ing TCDD-eq contaminant ranges were reported:
Treatment and sludge drying areas: surface soils (0-6 inches) 6.2 to 36 ppb and subsurface (0-8
feet) 0.03 to 25 ppb.
Wood-stacking areas: surface soils 0.11 to 13 ppb and subsurface 0.000029 to 0.049 ppb.
Roadways: surface soils 0.018 to 0.74 ppb and 0.000017 to 0.22 ppb subsurface.
Vegetated areas: surface soils 0.0023 to 0.58 ppb and subsurface 0.049 to 1.3 ppb.
Off-site wetland sediments were sampled from the top six inches and the concentration range was
0.029 to 0.13 ppb.
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2.
Ground Water
Ground water hydrology and quality were mvesugated in the upper sand outwash aquifer. Twenty-sIx
mOnItoring wells and piezometers were installed as pan of the RJ. Ground water flow was
detennmed to be to the east with a slight southern component of ground water movement in the
treatment area and a slight nonhern component of flow for ground water north of the treatment area.
Site contaminants were detected in the upper sand aquifer.
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The contaminants in the shallow ground water that present a risk to the environment or public health
are PCP and TCDD-eq. In generaL the highest contaminant concentrations are found in the shallow
monitoring wells surrounding the wood treatment areas. The range of PCP concentrations in this
area are 88 to 1800 micrograms per liter or ppb. TCDD-eq concentrations range from 56 to 1640
nanograms per liter or ppt. The PCP and TCDD-eq concentrations decrease with distance
horizontally from the wood treatment area and with depth in the upper sand aquifer. The wells
located at the base of the upper sand aquifer were contaminated with TCDD-eq (0.77 to 25 ppt). The
PCP ranged from 3 to 370 ppb in these wells. The extent of the two contaminants appear to be
contained to the Ritari propeny: in general. the contaminants were not detected beyond the
piezometer and wells to the east of the operations area.
The lower sand and gravel aquifer was mvesngated with one deep soil boring which was completed as
deep monitoring well MW -11 D. The Ratcliff supply well is also completed in the lower sand and
gravel unit. No significant contaminant parameters of concern were indicated at MW-IID or the
Ratcliff private supply well. Deep sand and gravel aquifer ground water flow is inferred to be
directed eastward toward the Cat River. The confining clay till unit was found to be 26 feet thick and
is continuous beneath the Site area and the Ratcliff residence.
3.
Pond Water and Sediments
Other media assessed during the RI include the on-site pond water and bottom sediments and off-site
wetland sediments. The ponds are two manmade small borrow pits. The water in the ponds is an
expression of the ground water table. The ponds were evaluated to assess if surface runoff could be
caIr)ing contaminants to the ponds by sediment transpon or leaching from soils. The pond sediment
had PCP concentrations similar to the surrounding soil, therefore. the pond sediment was included
with the surrounding areas when characterizing PCP in soil. The pond water was not considered
representative of the surface water in the area and was not evaluated as an exposure pathway.
Wetland sediments located nonheast of the Site were analyzed for TCDD-eq. The concentrations
measured in the off-site sediments were very low. The highest concentration was only 0.14 mg/kg or
ppb. The most likely transport mechanism is "ind blown dust from the Site to the wetlands. Since
the TCDD-eq concentrations were low. the wetlands were dropped from further investigation. at this
Ume.
VI. SUMMARY OF SITE RISKS
The MDH performed a health assessment on the Site in December 1992. for the A TSDR The evaluation
was performed using the monitoring data collected during the RI.
The MDH concluded contamination at the Site poses a public health hazard to any people who have
access to contaminated soils and dusts. The potential hazard due to low level contamination of shallow
ground water under the Site and near a neighboring farm were considered an unlikely public health
hazard to well users. Contaminated media at the Site also pose a potential health risk to workers involved
in Site clean up and appropriate protection was recommended.
The exposure pathways are contact with. or mhalation of. soil. The potential human population exposed
to the greatest risk are people living at the Site. people who may visit the Ritari family or people who are
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on the Site to purchase treated wood products. The potential terrestrial population are domestic animals.
other mammals and birds which use the Site during grooming and cleaning activities. They may also
absorb contaminants from the soil through their skin or inhale them with dust. Other organisms. such as
insects and eanhworms. also may directly or mdirectly ingest contaminated soil and these organisms may
then be ingested as a food source as well.
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The major assumptions used to estimate e:\.-posure to children and workers to soil and dust at the Site were
as follows:
a. Exposure frequency (days/year) for children - 224
workers - 160
b. Exposure duration (years) for children - 6
workers - 30
c. Body weight (kilograms) for children - 15
workers -70
d. Ingestion rate (mg/soillday) for children - 200
workers - 100
e. Inhalation rate (m3/day) for children -10
workers - 20
During the RI study, a toxicity assessment and risk characterization of the contaminants of concern were
completed. The RI report, Chapters 6 and 7. describes these data in detail for both human and
environmental receptors.
For purposes of this ROD. two imponant factors will be discussed as they relate to the toxicity assessment,
cancer potency factor (CPF) and reference dose (RID).
Toxicity Assessment Summary:
CPFs have been developed by EP As Carcinogenic Assessment Group for estimating excess lifetime cancer
risks associated with exposure to potentially carcinogenic chemicals. CPFs. which are expressed in units
of (mg/kg-day)- L are multiplied by the estimated intake of a potential carcinogen. 10 mgikg-day. to
provide an upper-bound estimate of the excess lifetime cancer risk associated with exposure at that intake
level. The term "upper bound" reflects the conservative estimate of the risks calculated from the CPF.
Use of this approach makes underestimation of the actual cancer risk highly unlikely. Cancer potency
factors are derived from the results of human epidemiological studies or chronic animal bioassays to
which animal-to-human extrapolation and uncenainty factors have been applied.
RIDs have been developed by EP A for indicating the potential for adverse health effects from exposure to
chemicals exhibiting noncarcinogenic effects. RIDs. which are expressed in units of mgikg-day, are
estimates of lifetime daily exposure levels for humans. including sensitive individuals. Estimated intakes
of chemicals from environmental media (e.g., the amount of a chemical ingested from contaminated
drinking water) can be compared to the RID. RIDs are derived from human epidemiological studies or
animal stUdies to which uncertainty factors have been applied (e.g.. to account for the use of animal data
to predict effects on humans.) These uncertainty factors help ensure that the RIDs "ill not underestimate
the potential for adverse noncarcinogenic effects to occur.
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The two contaminants of concern for both soil and ground water are PCP and dioxinJfuran. PCP is a
senu-volatile. It IS currently rated as a B2 carcmogen. PCP has caused multiple tumor types in mice. and
11as an upper 95 percent confidence-limit estimate of its CPF of 0.12 per mg/kg/day. PCP also causes
noncarcinogenic effects such as liver and kidney damage m rats. PCP's RID is 0.03 mg/kglday.
DioXIns and furans are relatively nonvolatile organic compounds that are inadvenently produced during
productIon of other chemicals such as pesticIdes. and during mcmeration of chlorine-containing
-:ompounds. As a result of exposure from a vanety of sources. most Americans have "about 30 ppt of
dIOXInS in their blood. including about 7 ppt of TCDD" (Schmidt 1992).
The most toxic of all dioxins and furans is thought to be 2.3.7.8-TCDD. By convention. the toxicities of
the other dioxins and furans are related to the toxicity of 2.3.7.8-TCDD by a range off actors less than
one. The 2.3.7.8-TCDD congener is rated as a B2 carcinogen with an upper 95 percent confidence-limit
estimate of its CPF of 150.000 per mg/kg/day. No information was available in IRIS or HEAST regarding
the noncarcinogenic effects of exposure to this compound. However. exposure to dioxins is known to
produce a noncarcinogenic skin disorder called chloracne. The lack of an RID for TCDD is therefore a
source of uncenainty for the risk characterization. .
~oncancer hazard quotients (HQ) and excess lifetime cancer nsks are the two indices used to quantify the
nsk of human ex-posure to the identified contarnmants of concern in the various media at the Site. HQ
and excess lifetime cancer risks appear to be the same types of numbers but actually describe risk quite
differently.
Risk Characterization Summary:
Excess lifetime cancer risks are determined by multiplying the intake level with the cancer potency factor.
These risks are probabilities that are generally expressed in scientific notation (e.g., lxlO-6 or lE-6). An
excess lifetime cancer risk of IxIO-6 indicates that as a plausible upper bound. an individual has a one in
one million chance of developing cancer as a result of site-related exposure to a carcinogen over a 70-year
lifetime under the specific exposure conditions at a site.
Potential concern for noncarcinogenic effects of a single contaminant in a single medium is expressed as
the HQ (or the ratio of the estimated intake derived from the contaminant concentration in a give medium
to the contaminant's reference dose). By adding the HQs for all contaminants within a medium or across
all media to which a given population may reasonably be exposed. the Hazard Index (HI) can be
generated. The HI provides a useful reference point for gauging the potential significance of multiple
contaminant exposures within a single medium or across media.
Risk to current residents near the Site are likely to be low since they rarely visit the Site. The only
contaminant detected in the ground water from residential wells was dioxin. The carcinogenic risks
associated with the levels detected were 6.69E-7 and 9.33E-7 for samples from two monitoring wells on
the Ritari propeny. Dioxin was also detected in the Ratcliff supply well at a level associated with a risk of
1. 94E-6.
Current or future workers at the Site may experience elevated risks from daily exposure to the Site. Skin
absorption poses the greatest noncarcinogenic hazard and carcinogenic risk. followed by ingestion and
inhalation. Combined noncarcinogenic hazard quotients for these pathways range between 3.39 and 5.8,
and carcinogenic risks range between 6.68E-3 and 1.29E-l.
If no action is taken at this Site. future residents have the potential to experience elevated health risks.
TCDD-eq concentrations in ground water in a site boundary well are associated with risk ranging between
U5E-5 and 3.17E-5. TCDD-eq on site are higher. In the future. migration ofTCDD-eq and PCP. which
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13
is also present. WIth the ground water may pose elevated risk to residents using the ground water. At the
conclusion of all actions to be taken at this Site. future residents should experience no elevated. health
risks posed by this Site.
The results of baseline risk assessments indicate these threshold risks are exceeded for PCP and TCDD-eq
and exposure routes under the assumptions employed. Therefore. action is warranted to prevent future
exposure of residents and workers to both TCDD-eq and PCP at the Site. TCDD-eq is particularly
dangerous to future residents and workers via the followmg pathways: through ingestion of ground water
or through ingestion. skin absorption. or inhalation of conrarrunants from soil or dust.
Both PCP and dioxin are rated B2. meaning they have less certainty in judgment of human carcinogenesis
and in the CPF than contaminants rated A. CPF's and ratings for B carcinogens are more likely to change
than those for A carcinogens. as additional expenmental data become available. New data may cause
changes in either direction. toward greater or lesser CPFs or carcinogenic ratings. Confidence in the
RID's for PCP is rated as medium. but for 2.3,7,8-TCDDthere is no information provided for the
confidence.
In summary. greater confidence in a CPF or RID produces greater confidence that toxicity values will not
over- or underesumate the actual toxicity of anv given compound. Less confidence indicates. as additional
expenmental data becomes available. researchers may discover previous estimates either over- or
underestimated actual toxicity to humans.
A. Environmental Risk Assessment
The scope of this evaluation of environmental risk included qualitative discussions of uptake of
contaminants from soil, surface water, and air at the Site by aquatic and terrestrial organisms. Due to the
general lack of toxicological infonnation and exposure data for potential environmental receptors.
environmental risks were evaluated qualitatively, rather than quantitatively, and only for those
contaminants also found to be of human health concern. Also. since on-site contamination did not appear
to be moving off site in concentrations approaching risk levels. the need to complete a full environmental
risk assessment did not seem warranted.
Contact with. or inhalation of, soil appeared to pose the greatest risk to domestic or wild animals in the
area of the Site. On-site concentrations exceed literature reponed values which have been observed to
affect development and increased monaJity in animals.
The possibility exists for extremely low concentrations of PCP and TCDD-eq in off-site wetland surface
water based upon very low levels of TCDD-eq contained in the wetland sediment samples. However.
uptake from water was not deemed to be a significant e:\:posure route in wetland floral and faunal
communities. Contaminant movement with airborne dust is another pathway for exposure to animals
(inhalation) and plants (deposition and subsequent uptake). Finally, food sources from the Site that are
utilized by the local domestic and wild animal populations present a pathway for bioaccumulation.
B. Human Health Risk Assessment
The human health risk assessment included quantification of risks for the potential routes of exposure of
ingestion of ground water. ingestion of soil. skin absorption of contaminants from soil. and inhalation of
contaminants on dust More qualitative risk characterization was completed for the potential routes of
exposure of inhalation of vapors and exposure to surface water. Both the noncarcinogenic and
carcinogenic effects of contaminants were evaluated. .
The highest PCP concentrations measured in ground water were in well MW-3U ranging from 1,800 to
6.400 microgram/liter (ug/L). The federal MCL forPCP is I ug/L. Based on these numbers. PCP poses a
risk of adverse. carcinogenic health effects. However. the contaminant considered to pose the greatest risk
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of adverse. carclnogeruc health effects is TCDD-eq which has an MCL of 0.03 nanogram/Liter.
Carcinogemc nsks associated with the upper 95 percem confidence-limit estimate of the average TCDD-
-:q ground water concentration range between 2.15 E-3 and 2.87 E-3. This range IS higher than EPA's
acceptable risk of range 1.0 E-4 to 1.0 E-6. or 1 In 10.000 to I in 1.000.000.
Milk was collected from the Ratclifi's dairy cows. The milk contained detectable levels of TCDD-eq.
However. based on the samples analyzed and the level of TCDD-eq measured in the blank sample. the
levels do not appear to be significantly higher than TCDD-eq In milk from other local and international
sources.
Vapor sampling was nO[ Included in the Rl: however. a screening level evaluauon Indicated vapors could
potentially pose elevated carcinogenic risks to workers at the Site. Hazards from vapors of
noncarclnogeruc compounds at the Site are unlikely to result in adverse. noncarcinogemc health effects.
Exposure. of workers or children to contaminants in soil (excluding TCDD-eq) may result in adverse,
noncarcinogenic health effects. The lack of quantifiable data regarding the noncarcinogenic effects of
exposure to TCDD-eq was a source of uncenainty in the risk characterization. However. under the given
exposure scenarios. combined carcinogenic risks from exposure to site soils under all scenarios are
significantly elevated (greater than approximately I.OE-3). The contarmnants posing the majority of the
risk are TCDD-eq and PCP. The route of exposure resulting in the greatest risk is skin absorpuon.
followed closely by Ingestion. and lastly by inhalation of dust.
The results of the baseline risk assessment indicated the threshold risks were exceeded for cenain
parameters and exposure routes under the assumpuons empioyed. Therefore. action is warranted to
prevent exposure to site contaminants. particularly TCDD-eq, through ingestion of ground water (life time
risk of 2.15E-3 - 2.87E-3), or through ingestion. skin absorption. or inhalation of contaminants from soil
or dust. Actual or threatened releases of hazardous substances from this Site. if not addressed by
implementing the response action selected in this ROD. may present an imminent and substantial
endangerment to public health. welfare. or the environment.
VII.
DESCRIPTION OF AL 1ERNATIVES
In this section different technology types and process options for the remediation of soil and ground water
are assembled into alternatives. The alternatives represent a range of remedy options that vary in degree
of removal and treatment of contaminated media. The alternatives are focused on presumptive remedies.
which have been developed on the basis of the regulatory history of remediation of wood treatment sites.
A list of the alternatives for remediating contaminated soil and ground water are presented below. A
more thorough description of each alternative follows.
List of Soil Alternatives
1.
Institutional controls. on-site incineration of TCDD-eq and PCP contaminated soils.
2. Institutional controls. off-site incineration of TCDD-eq contaminated soils. on-site solid phase
bioremediation (land treatment) of PCP contaminated soils.
3.
Institutional controls. construction of a Resource. Conservation and Recovery Act (RCRA) compliant
containment building for TCDD-eq contaminated soils. land treatment of PCP contaminated soils.
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~.
Institutional controls. consolidation and construction of a RCRA compliant cap for TCDD-eq
contaminated soils and land treatment of PCP contaminated soils.
5.
No action.
List of Ground Water Alternatives
I.
Institutional controls. abandonmem of the existing Ritari water supply weil. installation of a new on-
site water supply well in the deeper aquifer. installation of additional downgradient monitonng wells.
and monitoring.
2.
InstitUtional controls. abandonment of the existing Ritari water supply well. installation of a new on-
site water supply well in the deeper aquifer. vertical well extraction. bioreactor treatment, granular
activated carbon (GAC) treatment. on-site reinjection of treated water with ox'ygen and nutrient
amendments. and monitoring.
3.
Institutional controls. abandonment of the existing Ritari water supply well. installation of a new on-
site water supply well in the deeper aquifer. vertical well extraction. ultravioiet (UV)/oxidation
treatment. GAC treatment. on-site reinjection of treated water with oxygen and nutnent amendments.
and monitoring.
~.
No action.
Description of Soil Alternatives
The following paragraphs provide more detailed descriptions of soil and ground water alternatives. All
alternatives which require the excavation of soils will also require regrading and revegetation of the
affected area.
Prior to the implementation of any of the soil alternatives except the alternative where no action is taken.
wood treatment process equipment and appunenances require dismantling, decontamination and disposal.
Debris which remains contaminated with PCP andlor TCDD-eq above clean up standards will be
disposed at a pennined hazardous waste facility. Detailed information on these activities will be
addressed during remedial design.
Alternative 1. Institutional controls. on-site incineration of TCDD-eq and PCP contaminated soils.
InstitUtional controls include restricting access to the contaminated soils and the Site by fencing. A well
advisory. established by the Minnesota Department of Health in conjunction with the MPCA, will prevent
the installation of water supply wells in the contaminated upper aquifer iil the area of the Site. Deed
restrictions pW'SUant to Minn. Stat. ~ IISB.16 will be filed and recorded with the register of deeds in
Wadena County to prevent future use of the property which may result in a release of. exposure to.
existing contamination (i.e., excavation. farming, residential use. etc.).
A mobile incinerator will be brought to the Site for incineration of both TCDD-eq and PCP contaminated
soils. The incinerator will be assembled nithin the fenced area. Approximately 1800 cubic yards of
TCDD-eq contaminated soils and 5000 cubic yards of PCP contaminated soils \\ill be excavated and
treated within the unit. The area of excavation will be based on data obtained during the remedial
investigation. supplemented by additional verification sampling to be conducted during excavation.
A trial bum will be conducted to .verify the adequacy of the incinerator for site-specific and surrogate
wastes pnor to treatment of contaminated soils. Depending on the design of the incinerator. soils may be
excavated. packaged. and stored prior to treatment. or immediately placed into the unit. The
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contaminated soils will be managed in a manner. during excavation and handling. to reduce and prevent
additional contaminant migration. Based on sampling analysis. the residuals of incineration may be
placed back into the excavated area (if the residuals meet health based levels of contamination). regraded.
covered With top soil and seeded. or transponed off site for disposal.
The components of this alternative. if properly implemented. will comply with all applicable or relevant
and appropnate requirements (ARARs). pursuant to Section 12 1 (d)(2)(A) of the Comprehensive
Environmental Response. Compensation and Liability Act (CERCLA). as amended. 42 U.S.c. ~
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Alternative 3. Institutional controls. construction of a Resource. Conservation and Recovery Act (RCRA)
compliant contamment building for TCDD-eq contammated soils. land treatment of PCP contaminated
soils.
The institutional controls and land treatment of PCP comarrunated soils. as previously described. remain
unchanged in tlus alternauve. The TCDD-eq contaminated soils "ill be excavated and placed within a
RCRA-compliam storage building. The storage building will be designed and constructed to be
completely enclosed. with self supporting walls. a primary barrier and liquid collection system and
controls to prevent fugitive dust and tracking of materials outside of the unit. Soils will be stored in this
manner until a cost-effective treatment and/or disposal option is available.
ARARs identified for the components of this alternative are the following: (1) 40 CFR ~~ 264.1100-
264.1102 (RCRA requirements applicable to container buildings) and (2) 40 CFR ~~ 264.270-282 (RCRA
regulations applicable to land treatment of hazardous waste - see discussion on bioremediation in Soil
Alternative 2). These RCRA regulations are triggered by the storage and land treatment of F032 waste.
The waste may be Slored beyond one year if the Regional Administrator makes a determination pursuant
1040 CFR ~ 268.50.
The present net wonh of this alternauve IS $795.000.
Alternative 4. Institutional controls. consolidation and construction of a RCRA compliant cap for TCDD-
eq contaminated soils and land treatment of PCP contaminated soils.
The institutional controls and land treatment components of this alternative remain unchanged from the
previous description. TCDD-eq contaminated soils will be consolidated prior to placement of a RCRA-
compliant cap over the area. The cap will be multi-layered in construction. Typical cap designs include a
low permeability layer, drainage layer. geotextile. soil layer. and vegetated topsoil.
The components of this alternative complies with all ARARs. ARARs identified for the components of
this alternative are the following: (I) 40 CFR ~ 264.310 (RCRA regulation applicable to capping); (2) 40
CFR 264.270-282 (RCRA regulations applicable to land treatment of hazardous waste - see discussion on
bioremediation in Soils Alternative 2), and (3) 40 CFR ~~ 264.117-120 (other RCRA closure
requirements). Consolidation and capping of waste on site triggers certain closure requirements under
RCRA.
The present net wonh of this alternative is $771.000.
Alternative 5. No action
The no action alternative serves as a baseline for comparison of all remedial alternatives. Site conditions
remain unchanged. Cleanup goals for soil contaminants will not be met under this alternative.
The present net worth of this alternative is SO.
Description of Ground Water Alternatives
Alternative 1. Institutional controls. abandonment of the Ritari well. installation of a new water supply
well upgradient in the deeper aquifer, installation of additional downgradient monitoring wells, and
monitoring. .
The institutional controls described in Alternauve I for the contaminated soils portion of the remedial
action remaIns unchanged. The Site will be fenced. deed restrictions imposed and a well advisory put in
place.
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Ground water within the upper aquifer. beneath the contaminated soils. is contaminated. Currently. only
one residential well within the upper aquifer (the Ritan well) is bemg used to supply drinking water at the
Site. Two additional supply wells are located In the process area on the Site. These wells will need to be
abandoned. A replacement well for the Ritari household will be installed in the deep aquifer at a location
west of the Site. This will provide the Ritaris \\lth a clean. long-term supply of drinking water.
The contaminated ground water in the upper aquifer below the comanunated soils will no longer be a
::urrent or potential source of drinkmg water once the new well and msututional controls are m place.
Remediation of contanunated soils will reduce the potenual for contaminants to move into the underlying
ground water. The contaminant levels should be greatly reduced after the source (the soil) is removed.
Long-term ground water monitoring will proVIde information about natural reduction of the ground water
contaminants.
The Maximum Contaminant Levels (MCLs) established pursuant to the Safe Drinking Water Act
(SDW A). ~2 U.S.c. ~ 300f. et seq.. as amended. are not applicable. but are relevant and appropriate
requirements because this is an aquifer which may be used as a drinking water source near the Site. The
MCL for PCP is I ppb. The MCL for TCDD-eq IS .03 ppt. Additional monitoring wells will be added to
monitor downgradient conditions in the ground water. Continued monitoring of the upper and lower
aquifers for TCDD-eq. PCP and appropriate Indicator parameters "lil be done quarterly. with annual
reponmg of results. MCLs will be met at the Ritari property boundary. If ground water monitoring
demonstrates that contaminated ground water \\ill move beyond the Ritari property line at levels of
contamination above the MCLs. the affected ground water will reqwre treatment.
Additional monitoring wells will be added to momtor downgradient conditions in the ground water.
Continued monitoring of the upper and lower aquifers for TCDD-eq. PCP. and appropriate indicator
parameters will be done quarterly. with annual reporting of results. The frequency of and parameters for
Site ground water monitoring will be reviewed and possibly modified after four quarters of monitoring
data have been collected. Monitoring plan modifications may be made based on historical patterns and
trends in the data results. Indicator parameters may be used as deemed appropriate from the base line
data information. MCLs will be met at the Ritari property boundary. If ground water monitoring
demonstrates that contaminated ground water will move beyond the Ritari property line at levels of
contaminauon above the MCLs. the affected ground water will reqwre treatment.
The present net wonh of this alternative is $332.000.
Alternative 2. Institutional controls, abandonment of the Ritari well. installation of a new water supply
well upgradient in the deeper aquifer. vertical well extraction. bioreactor treatment. GAC treatment. on-
site reinjection of treated water with oxygen and nutrient amendments. and monitoring.
The institutional controls. well abandonment. installation of a new water supply welL and monitoring
remain unchanged from Alternative I for ground water. In this alternative. contaminated ground water is
extracted via wells from the contaminated upper aquifer. The PCP in the water is treated using biological
degradation in an above-ground treatment tank. RCRA regulations at 40 CFR Pan 264 Subpan J
regarding tanks are applicable. Following biological treatment. the water will be passed through granular
activated carbon (GAC) to remove both PCP and TCDD-eq. Contanunated GAC will be disposed of off-
site in the appropriate fashion. Oxygen and nutrients will be added to the treated water. prior to
reinjection on site in the upper aquifer. to enhance in-situ biodegradation of PCP. Additional wells will be
installed during the implementation of this alternative. Well placement. extraction rates. treatment
system design and reinjection rates will be determined during the remedial design.
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The Maximum Contaminant Le\'els (MCLs) established pursuant to the Safe Drinking Water Act
(SDW A). ~2 U.S.c. * 300r. et seq.. as amended. are not applicable. but are relevant and appropnate
requirements because this is an aquifer which may be used as a drinking water source near the Site. The
MCL for PCP is I ppb. The MCL for TCDD-eq is .03 ppt.
The present net worth of this alternative is $1.180.000
Alternative 3. Institutional controls. abandonment of the Ritan well. installation of a new water supply
well upgradient in the deeper aquIfer. vertical well extraction. UV/oxidation treatment. granular activated
carbon (GAC) treatment. on-site reinjection of treated water with oxygen and .
nutrient amendments. and monitonng.
The institutional controls. well abandonment. installation of a new water supply well. and monitoring
remain unchanged from Alternative I for ground water. In this alternative. contaminated ground water is
extracted via wells from the contaminated upper aquifer. The PCP in the water is treated using ultra
violet (UV)/oxidation. in the above-ground treatment tank. RCRA regulations at 40 CPR Part 264
Subpart J regarding tanks are applicable. Following UVioxidation treatment the' water will be passed
through GAC to remove any remaming PCP and TCDD-eq. Contaminated GAC \\ill be disposed of off-
site in the appropnate fashion. O;,..ygen and nutrients will be added to the treated water prior to reinjection
to enhance in-situ biodegradation of PCP. Additional wells will be installed dunng the implementation of
this alternative. Well placement. extraction rates. treatment system design and reinjection rates will be
determined during remedial design.
The Maximwn Contaminant Levels (MCLs) established pursuant to the Safe Drinking Water Act
(SDW A). 42 D.S.C. ~ 300f. et seq.. as amended. are not applicable. but are relevant and appropriate
requirements because this is an aquifer which may be used as a drinking water source near the Site. The
MCL for PCP is I ppb. The MCL for TCDD-eq is 0.03 ppt.
The present net worth ofthis alternative is $1,300.000.
Alternative 4. No Action
As described in the proposed soil alternatives. the no action alternative serves as a baseline for comparison
of all remedial alternatives. Site conditions remain unchanged. The Maximum Contaminant Levels
(MCLs) established pursuant to the Safe Drinking Water Act (SDW A). 42 U.S.c. ~ 300f. et seq.. as
amended. are not applicable. but are relevant and appropnate requirements because this is an aquifer
which may be used as a drinking water source near the Site. The MCL for PCP is I ppb. The MCL for
TCDD-eq is .03 ppt. MCLs would not be met by this alternative.
The present net worth of this alternative is SO.
VIII. SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES
A. The Nine Evaluation Criteria
In accordance with the National Oil and Hazardous Substances Pollution Contingency Plan (NCP).
the relative performance of each alternative is evaluated using the nine criteria. Title 40 of the 40
CFR Section 300.430(e)(9)(iii). as basis for comparison. An alternative providing the "best balance"
of tradeoffs. with respect to the nine criteria. is determined from this evaluation.
Overall protection of human health and the environment. and compliance with ARARs are threshold
criteria that must be met in order for an alternative to be selected.
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The alternatives were evaluated according to the following nine criteria which are used by the EP A to
provide the rationale for the selection of a remedy for the Site:
I. Overall Protection of Human Health and the Environment addresses whether or not a remedy
provides adequate protection and describes how nsks posed through each pathway are eliminated.
reduced or controlled through treaunent. engmeering controls. or institutional controls.
2.
Compliance with State and Federal Regulauons (ARARs) addresses whether or not a remedy will
meet all the applicable or relevant and appropnate requirements of federal and state
enVIronmental statues and/or provides grounds for invoking a waiver.
3.
Reduction of Toxicity. Mobility. or Volume is the anticipated performance of the treaunent
technologies a remedy may employ.
4.
Short -Term Effectiveness addresses the period of time needed to achieve protection. and any
adverse impacts on human health and the environment that may be posed during the construction
and implementation period until cleanup goals are achieved.
5.
Long-Term Effectiveness and Permanence refers to the ability of a remedy to mamtain reliable
. protection of human health and the enVIronment over time once cleanup goals have been met.
6.
Implementability is the technical and adminisuative feasibility of a remedy. including the
availability of materials and services needed to implement a particular option.
7.
Cost includes estimated capital and operation and maintenance costs. and total present worth
costs.
8. State Acceptance indicates whether. based on its review of the RIlFS and the Proposed Plan. the
state recommends the alternative.
. 9. Community Acceptance is assessed in the Responsiveness Summary, attached to this ROD based
on a review of the public comments received on the RIlFS report and the PP.
SOIL
l.
Overall Protection of Human Health and the Environment
The no-action alternative does not provide for protection of human health and the environment.
Unacceptable risks are left on site unmitigated and unmanaged. The other four alternatives provide
for a high level of long-term protection. Alternative 1, where TCDD-eq and PCP soils are
incinerated. provides the most protection compared to the other soil alternatives as PCP and TCDD-
eq are destroyed. Alternative 2 (incinerate TCDD-eq soils. bioremediate PCP soils) provides a
slightly lesser degree of protection as PCP is biodegraded on site and TCDD-eq are burned off site.
Alternatives 3 (RCRA-compliant containment for TCDD-eq soils. bioremediation of PCP soils) and 4
(RCRA cap over TCDD-eq soils. bioremediation of PCP soils) provide lesser degrees of protection
because TCDD-eq contaminated soils are contained and not destroyed. Under alternatives 3 and 4.
these contaminants may remain at the Site forever.
2.
Compliance with Applicable or Relevant and Appropriate Requirements (ARARs)
All the alternatives can be designed and implemented in such a way as to comply ",ith all ARARs.
with the exception of the no action alternative. The no action alternative leaves wunanaged
hazardous wastes on site. Soils Alternative 3 (storage ofTCDD-eq in a container building) is limited
in its usefulness. Applicable RCRA requirements on storage of restricted wastes prohibit such storage
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for more than one year unless it can be proven that such storage is solely for the purpose of
accumulation of such quantities of hazardous waste as are necessary to facilitate proper recovery.
treatment. or disposal.
1,
Reduction in Toxicity. Mobility or Volume
Alternative I provides the greatest degree of reduction by destroying all PCP and TCDD-eq in
contaminated soils via incineration. Alternative 2 proVIdes for the destruction of TCDD-eq
contaminated soils. Successful land treaunent of the PCP contaminated soils will provide for a
reduction of toxicity. mobility and volume of these soils. Alternatives 3 and 4 fail to reduce the
toxicity or volume of TCDD-eq soils. but both will reduce contaminant mobility into the underlying
ground water.
~.
Shon-Term Effectiveness
Alternative I provides the greatest protection of community and the environment as TCDD-eq and
PCP soils are incinerated on site in a relatively shon time period. Protection of workers is similar to
other a!ternauves requiring construction and treatment activities. Alternative 2 provides the neXt
highest level of shon-term effectiveness. In this alternauve TCDD-eq soils are rransponed off site
and incinerated. so shon-term impactS are mmimai. PCP soils. however. are treated on SIte. This
treatment acti\ity is designed to be protective of community. workers and the environment. but will
last for tWo years or more. Alternatives 3 and 4 are equally protective. PCP soils are handled just as
in Alternative 2. TCDD-eq soils are either contained in a building (Alternative 3) or capped
(Alternative 4). Soil excavation and construction of a building or cap will be of short duration
(several weeks) and will be designed to be protective of community, workers and the environment.
Containment and maintenance activities are long term. but are minimal. non-disruptive activities that
will have little impact. The no-action alternative does not have short-term effectiveness concerns as
no actions are taken.
5.
Long-Term Effectiveness and Permanence
Alternative I is the most effective and permanent because all contaminants are destroyed. Alternative
2 may provide equivalent protectiveness and permanence. provided that land treatment of PCP
contaminated soils is successful in reducing the concentration of PCP to the clean-up level.
Alternative 3 is an above-ground storage unit which provides no long-term effectiveness or
destruction (permanence) ofTCDD-eq soils. Alternative 4 provides limited effectiveness by
eliminating potential direct contact with contaminated soils and reducing the future migration of
contaminants into the ground water. The cap will require maintenance and controls to prevent
damage to its integrity. thereby lessening the degree of permanence.
6.
Implementability
Alternatives I through 4 are equally implementable with respect to the ability to construct and
operate. and the ability to monitor the effectiveness. Alternative 2 is the most easijy implementable,
provided an off-site incineration facility is available. In this case the permits for handling and
incinerating TCDD-eq soils should already be in place. Alternative I is the neXt most easily
implemented. In this case soils would be excavated.. burned on site and returned to the Site. This
alternative may be somewhat more difficult to implement because of the effort to set up the mobile
incinerator and reach acceptable operating conditions by conducting trial bums. Time would be
required for approvals and agency coordination. ..<\ltematives 3 and 4 are equally implementable as
soil handling and construction issues are similar for both. Alternatives 3 and 4 are judged less easily
implementable than the other two because space that could otherwise be used for land treatment
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,..,
would be occupied bv the containment facilities and would make the logistics related to soil
~:xcavation and stagmg more difficult. The no action alternative IS implementable: however. it leaves
Ilnmanaged. hazardous wastes on site.
7
Cost
Costs for Alternauve 1 are highest at an estimated value of $10.3 million. These costs may be
reduced If soil waslung proves to be a viable volume reduction technology during remedial design.
Alternative 2 IS the next most costly at an estimated COSt of $3.37 million dollars. As with
Alternative I. soH washmg may help to reduce the cost ofthis alternative. Alternative 3 is estimated
10 have capital costs of $641.000 with an additional $10.000 Operation & Maintenance for each year
the wastes are stored in the containment building: assuming a hypothetical 30 year project life this
gives a total present wonh cost of $795.000. Capital costs for Alternative 4 are estimated at $618,000
with a total present wonh cost 01'$771.000. There are no costs associated with the no-action
alternauve.
The present wonh cost range of the alternatives are as follows:
Alternauve 1
AlternatIve 2
Alternative 3
Alternauve 4
Alternative 5
$10.300.000
$ 3.370.000
$ 795.000
$ 771.000
$ 0
8.
State Acceptance
MPCA stafIprepared this ROD. The MPCA is the lead agency for this Site. and therefore accepts the
selected remedy. The EP A concurs with the selected remedy.
9.
Community Acceptance
The community accepted the PP.
GROUND WATER
1.
(A'erall Protection of Human Health and the Environment
In Alternative 1. on-site protection is achieved through access restriction. Off-site protection IS
achieved through monitoring and the trigger for additional remedial action if RAOs are exceeded at
the compliance boundary. Alternatives 2 and 3 provide about the same level of protection of human
health and the emironment and slightly more than Alternative 1 since some treatment is involved.
With both Alternatives 2 and 3 the PCP and TCDD-eq in the extracted ground water are treated. but
residual PCP and TCDD-eq remain adsorbed onto the aquifer solids. The reinfiltration with
amendments should stimulate biodegradation and accelerate cleanup. but the time required to reach
RAOs in the ground water is difficult to predict. The no-action alternative is not protective of human
health or the em ironment as contaminants are left untreated and unmonitored.
2.
Compliance \\ith Applicable or Relevant and Appropriate Requirements (ARARs)
All the alternatives can be designed and implemented 'in such a way as to comply with all ARARs.
with the exception of the no action alternative.
,
J.
Reduction in TOXJclt)'. Mobility or Volume
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-J
.<\Iternative I does not reduce tOXICltV. mobilitv or volume of contaminantS In ground water unless
Curther action is triggered. Alternauves 2 and 3 reduce the toxicity and voiume of PCP and TCDD-eq
111 on-site ground water. Alternatives 2 and 3 reduce the mobility of dissolved contaminants through
on-site gradiem comrol. The no-action alternative does not reduce toxicity. mobility or volume of
PCP or TCDD-eq.
4.
Short-term Effectiveness
Alternauves i. 2 and 3 are all protective of the community. workers and the em lronrnent during
remedial action Implementation. Fencing and well installations are short durauon activities (several
weeks) that are non-disruptive and are carned out on site. Monitonng is a rouune activity which is
also carned out on site and will not Impact local residentS or workers. With Alternatives 2 and 3. on-
site workers will be protected dunng construction and operauonal activities through health and safety
measures and engineering controls. Construction and stanup activities will last up to several months.
The no-action alternauve entails no actions of any kind. so there are no mcreases in short-term risks.
5.
Long-Term Effectiveness and Pennanence
None of the alternatives are long term and permanent m the sense that wastes are treated and the
ground water IS cleaned up m a finite. predictable penod of time. All alternatives leave some residual
contanunation in the on-SIte ground water that must be managed. In the case of .AJternative I no
ground water pumping occurs. Any remediation resulting in a decrease in the mass of PCP and
TCDD-eq in the aquifer is a result of natural attenuation. Management occurs through periodic
ground water momtoring and the tngger for further action if RAOs are exceeded at the compliance
boundary. Alternatives 2 and 3 actively attempt to clean up the PCP and TCDD-eq in on-site ground
water. The ultimate effectiveness of this cannot be predicted and it is likely there will be some
residual PCP and TCDD-eq left in on-site ground water. Controls in place "ith Alternatives 2 and 3
are ground water monitoring and gradient control through pumping and treating of extracted ground
water. For all alternatives. it is likely the controls will remain in place for a long time. For
Alternative I. long-term monitoring is estimated to last 30 years. For Alternatives 2 and 3, ground
water removal and treaUDent. along with monitoring is estimated to last ten years. The no-action
alternative is not effective or permanent as contaminants are left untreated and unmanaged.
6.
Implementability
Alternatives I. 2 and 3 are all technically feasible. Alternative I is easier ro construct and operate as
it only requires the installation and maintenance of a fence and the potential inStallation of additional
monitoring wells. Alternatives 2 and 3 are more difficult to construct and operate as they both
require the construction. monitoring and maintenance of pumping and treatment systems. All three
alternatives are reliable technologies and materials and services are readily obtained. All are
administratively feasible as permits can be obtained through agencies of the state of Minnesota.
Finally. additional remedial actions are easily implemented with any of the alternatives. The no-
action alternative is implementable: however. ground water standards are exceeded and no actions are
taken to treat or manage the comanunams.
7.
Cost
Alternative I is by far the least expensive. with an estimated total present worth cost of $322.000 for
30 years of monitoring. Alternative 3 is the most expensive alternative. estimated at $1.30 million
total present worth costs for a ten year project duration. Total present worth costs for Alternative 2-
are estimated at $1. 18 million for a ten year project duration. The time periods for system operation
and momtOnng are presented for the purpose of companng long-tenn costs. The actual durations of
these alternatives are not known for certain: thus. neither are the ultimate costs of implementation.
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2~
The present worth cost range of the alternatives are as follows:
Alternative I
Alternative 2
Alternative 3
Alternative 4
S 332.000
S 1.180.000
S 1.300.000
S 0
:).
State Acceptance
tv1PCA staff prepared this ROD. The MPCA is the lead agency for this Site. and therefore accepts the
selected remedy. The EPA concurs with the selected remedy.
9.
Community Acceptance
The community accepted the PP.
IX. THE SELECTED REMEDY
Based on considerations of the requIrements of CERCLA and the NCP. the MPCA selects Soils
Alternative 2. with a contingency of consolidation of both PCP and TCDD-eq contaminated soils and a
cap (with a design described in Soils Alternauve 4). and Ground Water Alternative 1 for ground water
cleanup. with Ground Water AlternatIve 2 as a contingency, as the most appropriate combination of
response actions for the Site. U.S. EPA concurs with the selected remedy.
Soils Alternative 2 includes the following components: institutional controls. off-site incineration of
TCDD-eq contaminated soils. and on-site solid phase bioremediation (land treatment) of PCP
contaminated soils. This alternative involves the excavation and treatment of contaminated soils. The
buildings, wood-treating equipment. and supplies found in the excavation and land treatment areas would
be dismantled and removed. Then the soils would be excavated. stockpiled. and segregated into PCP and
TCDD-eq piles. according to the results of field scree rung and confirmation by laboratory analysis. The
TCDD-eq contaminated soils would be shipped off-site to a permitted hazardous waste incinerator. Soil
washing will be further investigated to determine the overall cost and volume reduction of TCDD-eq
contaminated soils prior to off-site incineration. The PCP contaminated soils would be biologically
treated in a land treatment unit constructed on site. in accordance with requirements. The cost of
Alternative 2 is summarized in Exhibit 1.
The ARARs identified for the components of this alternative are the following: (I) 40 CFR 99 264.340-
343 and 40 CFR ~~ 264.345-351 (RCRA regulations applicable to the incineration of hazardous waste -
see discussion in Soil Alternative 1); (2) 40 CFR. ~~ 264.270-282 (RCRA regulations applicable to land
treatment of hazardous waste). The soil clean up standard for PCP is 40 ppm. The soil clean up standard
for TCDD-eq is I ppb.
During remedial design. studies will be conducted to determine if clean up standards will be achieved and
if the bioremediation remedy can be implemented. If the studies prove favorable for solid phase
bioremediation. a land treatment unit will be constructed in accordance with 40 CFR ~~ 264.270-264.282
to manage the PCP contaminated soils. If studies indicate that clean up levels will not be achieved. the
contaminated soils will be consolidated and the contingent cap remedy (with the design described in Soils
Alternative ~) will be triggered. Such studies are needed to assure compliance with 40 CFR. ~ 264.272
which requues a demonstration that Waste constituents can be completely degraded. transformed. or
immobilized in the treatment zone. prior to the application of the waste.
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.,.:;
I f after three years of land treatment the PCP contammared soil does not meet the cleanup standard (.W
parts PCP per mtllioni. the contingent response action of consolidation and cappmg tWlth the destgn
descnbed m Soils Alternative ~) will be triggered. ARARs identified for the capping conungency are the
following: 1) ~o CFR ~ 264.310 (RCRA regulation applicable to capping) and (2) ~() CFR ~~ 264.117-120
I other RCRA closure reqwrements).
[r the capping contingency is implemented. the additional present worth costs would be $ ~06. 725 as
detaIled In Exhibit I.
Ground water contamination will be remedied according to Ground Water Alternative I with Ground
Water Alternative 2 as a contingency remedy. Ground Water Alternative I includes the following
components: instirutional controls. abandonment of the eXIsting Ritari water supply well. installation of a
new on-sile water supply well in the deeper aquifer. installation of additional down gradient monitoring'
wells. and monitoring. The contaminated ground water in the upper aquifer below the contaminated soils
will no longer be a current or potential source of drinking water once the new well and institutional
controls are in place. The Maximum Contaminant Levels (MCLs) established pursuant to the Safe
Drinking Water Act (SDW At 42 U.S.c. ~ 300f. et seq.. as amended. are not applicable but are relevant
and appropriate because this is an aquifer whIch is or may be used as a drinking water source near the
Site. The MCL for PCP is I ppb. The MCL for TCDD-eq is .03 ppt.
Excavation and treatment of contaminated soils will reduce the potential for contaminants to move into
the underlying ground water. The contaminant levels should be greatly reduced after the source
(contaminated soils) is removed. Long-tenn ground water monitoring will provide information about the
natural reduction of the ground water contaminants. If ground water monitoring demonstrates that
contaminated ground water will move beyond the Ritari property line at levels of contamination above the
MCLs. the affected ground water will require treatment.
In the event that additional measures to contain and treat impacted ground water become necessary at the
Site. the contingency Ground Water Alternative 2 would be designed and implemented. Ground Water
Alternative 2 consists of the following additional components: vertical well extraction. bioreactor
treatment. granular activated carbon (GAC) treatment. on-site reinjection of treated water with oxygen
and nutrient amendments. and monitoring. The present worth cost estimate for Ground Water Alternative
2 is $1.177.000. The summary of costs for this contingency is presented in Exhibit 2.
X. STATIJTORY DETERMINATIONS SUMMARY
A. Protection of Human Health and the Environment
The selected remedy provides an overall protection of human health and the environment. by
removing and treating the contaminated soils and monitoring the water quality around the area of
detected ground water contamination. Institutional controls will be implemented during remediation
to assure additional protection to the public against exposure to contaminated soils and ground water.
These controls will also protect the public during soil excavation and until treatment is completed.
When confinnation sampling and analyses indicate a health based cleanup has been achieved. these
institutional controls will be removed.
Chapter 4725 of Minnesota State Law. concerning placement of drinking water wells. will be
implemented and nonessential wells will be abandoned. This chapter governs where drinking \',;ater
wells can be placed. The five year review required by CERCLAISARA will provide additional
assurance and potential controls for the protection of human health and the environment.
Monitoring of ground water quality will demonstrate the effectiveness of natura! attenuation over
time. As the ground water quality improves. the risks to both human health and the environment are
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26
reduced concomitantly within approximately 20-30 years. The combination of low levels of PCP in
the ground water. institutional control to prevent the use of ground water that tS and potentially may
be contammated with PCP. and naturai attenuation of those low ievels of PCP. provide a necessary
reduction of risk to human health and the environment.
B
Attamment of ARARs
The selected remed\" will comply with all Identified applicable or relevant and appropriate federal
reqUIrements. and with those state reqUIrements whIch are more stnngent. unless a waiver is invoked
pursuant to Section 121(d)(4)(B) of CERCLA.
Below is a discussion of the key ARARs for the selected remedy.
Resource. Conservation. and Recovery Act
RCRA reqUIrements are applicable at this Site because pentachlorophenol (F032) and TCDD-eq
(dioxin) wastes were disposed of after November 19. 1980.
.'
RCRA' Action-specIfic applicable reqUIrements
lncmeratlon
~o CFR Subpan 0 regulates the incineration of hazardous wastes. The incineration component
of the selected remedy will comply with these requirements off-site.
2.
Land Treatment
~o CFR Subpan M regulates the land treatment of hazardous waste. In meeting these land
treatment requirements. the selected remedy will ensure that hazardous constituents placed in or
on the treatment zone are degraded. transformed or immobilized within the treatment zone.
Land treatment will be within the area of soil contamination on site. Therefore. land disposal
restrictions are not applicable.
3,
Containment
RCRA Subtitle C regulates the closure of hazardous wastes for landfills (40 CFR ~ 264.310).
Additionally. post-closure requirements are provided in 40 CFR ~~ 264.117-120. The selected
remedy \,ill meet these requirements.
-J.
Clean closure
The selected remedy calls for the excavation and consolidation of contaminated soils from the
area of soil contamination in order to meet health-based clean up standards. In doing so, the
remedy will comply with the requirements for clean closure set forth in 40 CFR ~ 264.111.
5.
Tanks
40 CFR 264 Subpan J regulates the treatment of hazardous wastes in above ground tank units.
The selected remedy calls for a contingent ground water response action that involves the
biological treatment of extracted ground water in an above ground tank. The selected remedy
will comply with these requirements.
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7~
_I
Safe Dnnkmg Water Act
Federal Drinking Water Standards promulgated under the Safe Drinking Water Act (SOW A) mclude
both Maximum Contaminant Leyeis (MCLs) and non-zero Maximum Contarrunant Level Goals
(MCLGs). The NCP at .W CFR ~ 300.430(e)(2)(i)(B) provides that MCLGs established under the
Safe Drinking Water Act that are set at levels above zero and MCLs shall be attained by remedial
actions for ground waters that are current or potential sources of drinking water. The MCLGs for
pentachlorophenol and TCDD-eq. the contaminants at the Site are zero and therefore are not relevant
and appropriate.
At the Site. MCLs are not applicable. but are relevant and appropriate requirements. because the
unconfined aquifer could potenually be used in the future as a drinking water source. The MCL for
PCP is I ppb. The MCL for TCDD-eq IS .03 ppi.
The Preamble to NCP. 55 Federal Register 8753. provides that ground water clean up standards
should generally be attained throughout the contanunant plume or at and beyond the edge of the
waste management area when waste is left in place. MCLs will be met at the Ritari property
boundary.
C. Cost-Effectiveness
The selected remedy provides oyerall cost-effectiveness because the incineration of dioxin
contaminated soils off site is almost one-third the cost of on-site incineration. Soil washing Will be
evaluated during Remedial Design and could substantially reduce the total cost of remediating dioxin
contaminated soils. No other option exists to permanently treat dioxin. therefore. shon of containing
the dioxin contamination on-site for some future date. the selected remedy is costly but less costly
than the only other alternative.
With the installation of the additional monitoring wells and periodic ground water sampling, a high
degree of certainty will be achieved knowing where the ground water contamination is being naturally
attenuated. Replacement of the Ritari supply well further protects human health and removes the
need for active shallow aquifer pump out and treatment. The selected remedy can be implemented at
a cost far less than the cost of installing an active pump out system. which could not assure complete
removal in spite of significant financial outlay. at least double the cost of the remedies selected.
D. Utilization of Permanent Solutions and Alternative Treatment Technologies or Resource Recovery
Technologies to the Ma:ximum E:\."tent Practicable
The RALs. the combination of off-site incineration and on-site bioremediation. the installation of a
new residential drinking water well and additional monitoring wells. the periodic sampling, the
institutional controls and natural attenuation to reduce ground water contamination. will assure
permanency will be achieved through alternative treatment technology.
E. Preference for Treatment as a Principal Element
The selected remedy does eliminate the principal threats at the Site. through permanent removal and
incineration of dioxin contaminated soils. biodegradation of PCP contaminated soils to a level below
cleanup goals and restrictions of ground water usage. These remedies utilize permanent solutions for
the soils and alternative treatment technologies for the ground water.
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28
Treatment of the principal remaining threat to the ground water at the Site was not found to be
practicable or necessary. since PCP contamination does not appear to be leaving the. Site. If PCP
contamination does begin to show signs of movement off site in the future. the need for a treaunent
element to control or eliminate the PCP ground water contamination will be evaluated at that time.
XI. RESPONSIVENESS SUMMARY
This Responsiveness Summary documents the MPCA effons to ensure public panIClpaUOn during the
selection of a cleanup plan for the Site. The Summary includes an overview. a chronology of community
relations acuvities. the public's questions and comments on the FFS and PP. and the responses of the
MPCA and MDH to those questions and comments.
Overview
The cleanup alternative recommended by the MPCA and concurred with by the EP A for the Site includes:
fencing: deed restrictions: removal and disposal of structures 10 the area of contamination: excavation.
transponation. and off-site mcineration of diox1O-comaminated soils: biodegraw.tion of PCP S01l5 in on-
site land-treatment units: installation of a ne'w drinking-water well for the Ritari residence: Installation of
several downgradient ground water monitoring wells: and long-term ground water monnonng.
Tlus proposed cleanup plan was announced to the community through a news release to local papers: a
legal notice in the Sebeka Review Messenger: a fact sheet mailed to a list of interested parties. including
government officials: and phone call~ to selected individuals. .
The public comment period ran from January 19 through February 18, 1994. A public meeting was held
at the Sebeka City Hall on the evening of February 1, 1994.
Community Relations Chronology
Activities
Dates
o Community interviews
o Community relations plan
o Administrative Record at Wadena Public Library
o News release: Investigation begins
o Remedial Investigation fact sheet
o News release: Dioxin in soil
o Availability session in Sebeka
o News release: No dioxin found in residential wells
o Administrative Record reviewed
o Proposed PlanlPublic Meeting/Comment Period
- news release
- legal notice of comment period and meeting
- comment period
- fact. sheet to mailing list
- public meeting in Sebeka. MN
- transcript of public meeting to
Administrative Record
November 1987
December 1987
1990
May 2. 1990
November 1990
November 5. 1990
November 19. 1990
February 11. 1991
Summer 1993
January 18. 1994
January 19. 1994
Jan. 19-Feb. 18. 1994
January 19.1994
February 1. 1994
March 24. 1994
The Public's Questions and Comments on the Feasibility Study and Proposed Plan
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29
The following is a summary of the questions and comments received from the public and the responses of
the MPCA and the MDH to those comments. as transcnbed during the public meeting on February I.
['.194:
1.
Question: How will this affect the Ritaris? Are they going to have to pay for the cleanup?
I..
MPCA: We have determined that the Ritans do not have the resources. Federal Superfund will pay
for 90 percent. state Superfund will pay for ten percent of cleanup costs.
2.
Question: Have concentrations of contaminants gone down over the years?
MPCA: No. there are no clear trends in the data to suggest the levels of PCP or dioxins are declining
at the Site.
3.
Question: Was it originally a neighbor's complaint that brought action on this?
MPCA: Yes. However. the PCP found in the neighbor's well did not come from the Ritari site. None
of the contaminants were found in monitoring wells between the site and the neighbors'. No recent
detects of PCP or dioxin m the neighbors' well. \\' e do not know where the contammation in the
neighbors' well came from.
~.
Question: Why are you worried about the Ritari residential well? It is in the opposite direction from
the ground water flow?
MPCA and MDH: The ground water in the area is very near the surface. We are concerned that if
someone puts in another well it could cause a reverse draw on the ground water. Want to avoid any
possibility of the contamination getting into the Ritari residential well. The other wells on the site
will be closed as soon as the work is done. To add a degree of permanence to the remedy, we want to
put the residential well in a deeper aquifer. It is cheap protection. It would cost $2,000 a time to test
the well: in three years we would save money by putIing a new well.
5.
Question: How much dioxin is safe?
MPCA: Practically none. The water quality criteria for dioxin is 50 ppt.
6.
Question: Have there been any other situations like the Ritari's with similar levels of contamination
where it has been a proven hwnan health problem?
MPCA: Yes. there was the Love Canal site in New York and the Times Beach site in Missouri.
There are also other wood treating sites in the state of Minnesota.
7. Question: How high was the concentration in the neighbors' well?
MPCA: They peaked out at either 22 or 29 ppb. The concentrations kept going down. but not in
significant amounts. (Correction: The highest concentration of PCP in the Ratcliffwell was 55
ug/liter. The concentration had dropped to 39 uglliter when the well was retested).
8. Question: Why does Ritari get blamed for the contamination?
MPCA: Remember. we talked about Responsible Parties...(response interrupted by next comment.)
9.
Comment: Ritari will get run out of business. He \\1.11 have to tear down his buildings. He will lose
access to some of his property and equipment.
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MPCA: The Hazardous Substance Compensation Board is available to help people who feel they
have incurred losses because of contamination on their property. Regarding the buildings, we need
unobstructed access to the site. The office. tank and pad. drying shed. and tracks need to either be
moved' or demolished so we can treat the soil. The power line and access to the property could be
moved.
10. Question: How ''''Ill Ritan pay for movmg the buildings?
MPCA: Superfund cannot reimburse Mr. Ritari for movmg or demolishing his buildings. (Addition:
However. the Superfund will pay to have the buildings removed. Mr. Ritan does not have to pay for
the removal.)
11. Question: Ritari has to prove to you that it is less expensive to move the buildings than it is to
demolish them? '
:v1PCA: Just supply us with an estimate. We figured the cost of demolition would be about $400,000.
12. Question: Are the buildings contaminated?
MPCA: There is probably some contamination associated with them. There are things that can be
done to decontaminate them. though. Like washing down the walls. Cannot move the concrete slabs
or they would fall apart. But the buildings, the office and sheds. could be moved.
13. Question: What is the timetable you are looking at? Does he have time to go to the Hazardous
Substance Review Board?
MPCA: Not sure how long that process takes. Board meets once or twice a month. We will send you
a fact sheet that describes the process. Cleanup would probably begin next year. Glen would have all
of this year to look into moving the buildings. We do not need access until the next construction
season (1995). '
l~, Question: Will you use local contractors to do the work?
MPCA: We use local contractors whenever they are available. have the appropriate qualified
employees and are cost competitive.
15. Question: How long will Mrs. Ritari be without water when the new well is installed?
MPCA: We ,,,ill install the new well and then abandon the old one. Maybe an hour or so. Whatever
time it takes the plumber to transfer the piping from one well to the other.
One written comment was received that recommended that the "no action" alternative be selected.
MPCA: The "no action" alternative does not meet the nine cleanup criteria set by EPA.
The PP for the Site was released on January 19, 1994. The PP identified Alternative 2 for soils and
Alternative 1 for groood water as the preferred alternatives. MPCA reviewed all written and verbal
comments submitted during the public comment period. Upon review of these comments. it was
determined that no significant changes to the remedies. as they were originally identified in the PP. were
necessary.
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EXHIBIT 1
Ritari Post and Pole Superfund Site
Meadow Township, Wadena County, Minnesota
Record of Decision
COST SUMMARY FOR SELECTED REMEDY Al'iD CONTIl'lGENCY:
sons
SOIL ALTERNATIVE 2 (Off-Site Incineration and Land Treatment)
Item Ouantitv Unit Cost Cost
DemolitionlDisposal . I l.s. $48,000 $48,000
Excavation/Stockpiling 6800 cu yd $7.50 $51,000
Debris Screening 6800 cu yd $5.00 $34,000
Transportation 1800 cu yd $50 $90,000
IncinerationlDisposal 1800 cu yd $1,560 $2,808,000
Land Treatment Unit:
Liner 3 acres $37,300 $111,900
Construction/Soil Handling I l.s. $138,600 $138,600
Vendor Project Management I I.s. $35,600 $35,600
Additives, Labor and Equipment I I.s. $28,200 $28,200
Post-Treatment Conf=tion 24 samples $500 $12,000
RegradefI' opsoilN egetate 3 acres $5,500 $16,500
Total Capital Costs: $3,373,800
PW Long-Term O&M (30 yr, 5%) lyr $0 $0
Total Present Worth Costs: $3,373,800
CONTINGENCY. SOn. CAP COSTS:
SOIL ALTERNATIVE 4 (RCRA Cap and Land Treatment)
Item
Multilayer Soil Cap
RegradeffopsoilN egetate
Ouantitv
1 acres
3 acres
Total Capital Costs:
PW Long-Term O&M (30 yr, 5%) I yr
Contingency Total Present Worth Costs:
Unit Cost
$110,000
$5,500
SIO,OOO
Cost
$110,000
$16,500
$126,500
$153,725
$406,725
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EXHIBIT 2
Ritari Post and Pole Superfund Site
Meadow Township,Wadena County, Minnesota'
Record of Decision
COST SUMMARY FOR SELECTED REMEDY AND CONTINGENCY:
GROUND WATER
GROUND WATER ALTERNATIVE I (New Ritari Well and Monitoring)
Item
Drilling MobilizatiorvDemob
New Water Supply Well, 6"
Additional Monitoring Wells, 2"
Quantitv
I 1.s.
1 each
2. each
Total Capital Costs:
lyr
Total Present Worth Costs:
PW GW Monitoring (30yr, 5%)
CONTINGENCY- GROUND WATER PUMP AND TREAT COSTS:
GROUND WATER ALTERNATIVE 2 (Alt. 1+ Bioreactor/CarbonlReinjection)
Item
Drilling MobilizatiorvDemob
New Water Supply Well, 6"
Additional Monitoring Wells, 2"
Extraction Wells, 6"
Pump Test
Bioreactor, 60 gpm
Carbon Treatment Unit, 60 gpm
Nutrient Amendment Skid
Building, 500 sq tl
Reinfiltration Gallery
Quantitv
I 1.s.
I each
2 each
2 each
1 1.s.
I I.s.
I I.s.
1.1.s.
I 1.s.
I 1.5.
Total Capital Costs:
Iyr
lyr
Iyr
Iyr
Iyr
Total Present Worth O&M Costs:
Total Present Worth Costs:
PW Bioreactor O&M (10 yr, 5%)
PW Carbon O&M (10 yr, 5%)
PW Nutrient O&M (IOyr,5%)
PW Sys Inf/EffMon. (10 yr, 5%)
PW GW Monitoring (IOyr, 5%)
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Unit Cost
$1,500
$7,500
$3,000
$20,000
Unit Cost
$1,500
$7,500
$3,000
$5,000
$5,000
$105,000
$30,000
$10,000
$22,000
$15,000
$20,000
$30,000
$25,000
$30,000
$20,000
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Cost
$1.500
$7,500
$6,000
$15,000
$307,449
$322,449
Cost
$1,500
$7,500
$6,000
$10,000
$5,000
$105,000
$30,000
$10,000
$22,000
$15,000
$212,000
$154,435
$231,652
$193,043
$231,652
$154,435
$965,217
$1,177,217
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EXHIBIT 3
Ritari Post and Pole superfund site
Meadow Township, Wadena county, Minnesota
Record of Decision
ADMINISTRATIVE RECORD INDEX
Location: Wadena Public Librarv. 304-1st street S.W.
Wadena. MN 56482
preliminary Data/Investigations
HRS Scoring Package, January 31, 1986
FIT Team Investigation, May 1985
stipulation Agreement, May 13, 1976
MPCA Citizens' Board Item, February 25, 1986
MDH Health Assessment, December 1992
.
RI/FS process
Request for Determination of Inadequate Response, April 22,
1986
RI/FS Work Plan, December 22, 1989
Final RI/FS Support Document, February, 1990
Quality Assurance Program Plan, June 7, 1990
RI Report, December 22, 1992
Focused Feasibility Study, December 21, 1993
Proposed Plan, January 1994
.
.
Guidance Documents .
Risk Assessment Guidance for Superfund (December 1989)
Guidance for Conducting Remedial Investigations and
Feasibility studies Under CERCLA, OSWER Dir. No 9355.3-01
(October 1988)
Interim Final Guidance on Preparing Superfund Decision
Documents, OSWER Dir. No. 9355.3-02 (July 1989)
Minnesota superfund Fact Sheets
Permanent List of Priorities (MN Superfund List), June, 1993
community Relations
community Relations Plan, December 1987
News release: investigation begins, May 2, 1990
Remedial Investigation Fact Sheet, November 1990
News release: dioxin in soil, November 5, 1990
News release: no dioxin found in residential wells,
February 11, 1991
News release: proposed plan, January 18, 1994
Notice of comment period for proposed plan, January
Proposed Plan fact sheet, January 19, 1994
Transcript for Public Meeting on Proposed Plan,
February 1, 1994
.
.
19, 1994
.
.
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SITE LOCATION MAP
RITARI POST & POLE
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION 5
-:--:- WEST JACKSON BOULEVARD
CHICAGO. :L 60604-3590
D. 3 0 1994
:;EPL v -: THE ATTENTION OF
Mr. Charles W. Williams, Commissioner
Minnesota Pollution Control Agency
520 Lafayette Road, sixth Floor
st. .Paul, Minnesota 55155-4194
Re:
Concurrence on the Selected Remedy for the Ritari Post and
Pole Site, Meadow Township, Wadena County, ~innesota
" "
Dear Mr. Williams:
As you know, I am concurring in the selected remedy as embodied in
the Record of Decision ("ROD") for the Ritari Post and Pole Site
("Sitell) in Meadow Township, Wadena County, Minnesota. However, I
wish to clarify the United States Environmental Protection Agency's
position on a matter raised in the Responsiveness Summary section
of the ROD.
The Responsiveness Summary provides a summary of the questions and
comments received from the public and the responses of the
Minnesota Poll ution Control Agency ( "MPCA" ) and Minnesota
Department of Health. The first item states the following:
"1.
Question: How will this affect the Ri taris?
Are they going to have to pay for the cleanup?
MPCA: We have determined that the Ritaris do
not have the resources. Federal Superfund
will pay for 90 percent, state Superfund will
pay for ten percent of cleanup costs. II
Ritari Post and Pole site Record of Decision, at 29. While MPCA
may have made a determination that the Site owner does not have the
resources to pay for the cleanup, U.S. EPA has not reached that
conclusion. U.s. EPA's investigation of potentially responsible
parties at the Ritari Post and Pole Site is currently pending.
U.s. EPA does not consider potentially responsible parties for this
site to be relieved of their liability under the Comprehensive
Environmental Response, compensation and Liability Act on the basis
of MPCA's representation.
<.)
In addition, this concurrence is conditioned on a complete
administrative record being available to support this ROD.
"~
~~ Printed on Recycled Paper
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page 2
Concurrence Letter
Ritari Post and Pole Site
If you have any questions concerning ~his matter, please feel free
to contact me.
Sincerely yours,
// "
{t!ilr/!r~ !tItit
," Valdas V. Adamkas
~ Regional Administrator
"
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