PB96-963129
EPA/AMD/R05-96/314
May 1997
EPA Superfund
Record of Decision Amendment:
Kummer Sanitary Landfill,
Operable Unit 3, Beltrami County, MN
11/21/1995
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Minnesota Pollution Control Agency
0:
August 17, 1995 ; CO: , M/RF
LTR.
Mr. Valdus Adamkus
Regional Administrator
U.S. Environmental Protection Agency
Region V
77 West Jackson Boulevard
Chicago, Illinois 60604-3590
RE: Record of Decision Amendment
Kummer Sanitary F .andfiH
Dear Valdus:
The Minnesota Pollution Control Agency (MPCA) is submitting the enclosed Record of Decision
(ROD) Amendment for your review and signature. The ROD Amendment concerns the ground
water operable unit (OU3) for the Kummer Sanitary Landfill (Landfill) in Bemidji, Minnesota.
MPCA staff formally raised the issue of amending the ROD for OU3 in a letter to EPA dated
September 21, 1993. The original OU3 ROD called for an Advanced Oxidation Process (AOP) to
be installed as the ground water remedy. The ROD Amendment proposes a bioremediation remedy
as an alternative to the AOP.
A public meeting was held on June 5, 1995, in Bemidji and comments received at that meeting and
during the public comment period are included in the Responsiveness Summary. MPCA staff is
confident that the proposed bioremediation option will accomplish agreed upon cleanup goals and
meet the expectations of the public. EPA staff has reviewed the ROD Amendment and suggested
language changes have been incorporated into the text of the ROD Amendment.
MPCA staff appreciates your consideration and approval of this ROD Amendment and requests
your signature. If you have any questions regarding the ROD Amendment or any of the attached
documents, please feel free to contact Doug Wetzstein, Project Manager at 612/296-7277.
Sincerely
James L. Warner, P.E.
Division Manager
Ground Water and Solid Waste Division
JLW:dmh
Enclosure
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DECLARATION FOR THE RECORD OF DECISION AMENDMENT
SITE NAME AND LOCATION
Kummer Sanitary r.anrifiii
Northern Township
Beltrami County, Minnesota
STATEMENT OF BASIS AND PURPOSE
This decision document together with the Record of Decision (ROD) dated September 29. 1990. for
Operable Unit 3 (OU3) presents the final remedial action for the Kummer Sanitary f-andfin (Site)
developed 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 extent practicable, the National Oil and Hazardous Substances Pollution Contingency
Plan. The selection of the remedial action is consistent with the Minnesota Environmental Response and
Liability Act of 1983. The purpose of the final remedial action at the Site is to implement a remedy that
will protect human health and the environment.
The decision to amend the OU3 ROD is based upon the contents of the ROD Amendment summary. The
appendices also comprise information upon which the decision to amend the 1990 OU3 ROD and the
selection of the alternative remedial action are based
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from this site, which may present current or
potential risks to public health an^ welfare, or the environment, will be addressed by implementing the
response action selected in this ROD Amendment
DESCRIPTION OF THE REMEDY
Operable Unit 1 (OU1) addressed an alternate water supply for the affected residents in Northern
Township, Minnesota consisting of constructing two wells in a deep uncontaminated aquifer and a water
distribution system. Operable Unit 2 (OU2) is a source control in the form of a low permeability cap that
covers the Site. OU3 addresses the remaining threat of ground water contamination and is the final
remedial action for the Site. OU3 initially called for a Advanced Oxidation Process (AOP) system to
address contaminated ground water leaving the Site. The amffmlfd OU3 ROD calls for the use of other
measures to assume no exposure of contaminated ground water to potential receptors.
The major components of the amended remedy for OU3 include:
installation of a pilot scale field demonstration to determine feasibility of insitu biodegradation of the
chemicals of concern;
installation of a full scale insitu bioremediation system after one year of operation if it is necessary to
meet the Maximum Contaminant Level (MCL) for chemicals of concern. This is dependent on the
field scale demonstration proving effective at lowering contaminate levels that have not yet reached
the appropriate cleanup goal. If the pilot scale field demonstration is determined to be infeasible, an
active gas extraction system will be designed and installed;
long term monitoring of ground water to verify that chemicals of concern are continuing to decline
. and to measure performance of the pilot scale field demonstration and or full scale insitu
bioremediation system;
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continued observance of the Minnesota Health Department Well Advisory which regulates the
location of future potable wells near the Site:
institutional controls in the form of Site access restrictions that protect the remedy; and
operation and maintenance of the remedy, including periodic inspection of the Site to ensure
protectiveness.
STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the environment complies with Federal and State
requirements that are legally applicable or relevant and appropriate to the scope of this remedial action,
and is cost-effective and utilizes permanent solutions and alternative treatment or resource recovery
technologies to the mavimnm extent practicabk and satisfies the statutory preference for remedies that
employ treatment that reduces toxicity, mobility, or volume as a principal element
Because this remedy will result in hazardous substances remaining on-Site above health-based levels, a
review will be conducted within five years after commencement of remedial action and every five years
thereafter to ensure that the remedy continues to provide adequate protection of human health and the
environment
FEDERAL AND STATE CON
ValdUS V. Adamlnig
. Regional Administrati
Region V
Date
Williams
fT/MItiyit ^SjQUgf
Minnesota Pollution Control Agency
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RECORD OF DECISION AMENDMENT SUMMARY
KUMMER SANITARY LANDFILL
BELTRAMI COUNTY, MINNESOTA
L Introduction
The Kummer Sanitary Landfill (Site) is located in Northern Township, Beltrami County. Minnesota.
approximately one mile west of Lake Bemidji. The Site is located along the north side of Anne Street
NW, and midway between US 71 and State Highway 15 (Figure 1).
Northern Township has a population of about 4.000. Most of the township residents live east of the Site
near the City of Bemidji and along the western shore of Lake Bemidji. The land north and west of the
Site is sparsely settled but residential and commercial development is beginning to occur immediately
west of the Site. The closest occupied building is the Kummer residence located in the extreme southeast
corner of the property.
On September 29, 1984, the U.S. Environmental Protection Agency (USEPA) executed a Cooperative
Agreement for implementation of a Federal/State funded Remedial Investigation/Feasibility Study
(RI/FS). The Site was placed on the National Priorities List (NPL) in June of 1986, due to contamination
by volatile organic compounds (VOCs) in the surficial aquifer used for drinking water by Northern
Township residents. The USEPA initiated the Potentially Responsible Parry (PRP) search or enforcement
lead and the Minnesota Pollution Control Agency (MPCA) took the lead for remedial activities.
The purpose of this Record of Decision Amendment is to present a change for the Final Site Remedy
(FSR) or third operable unit (OU3) for the Site. The original FSR for OU3 was described in a Record of
Decision (ROD) issued on September 29,1990. Previously, a ROD was issued on June 12, 1985, for a
municipal water system (OU1) in Northern Township and a source control ROD was issued on September
29,1988, for a low permeability cap over the Site (OU2). OU1 and OU2 have been constructed and are
operational and functional at this time.
The circumstances leading to a need for a OU3 ROD Amendment are jumm^rired as follows:
all affected receptors have been connected to the water distribution system constructed as part of GUI;
institutional controls are in place to prevent potential receptors from exposure to contaminated
ground water,
ground water monitoring data trends indicate a continued decrease in concentration of chemicals of
concern, especially since the low permeability cap was installed-
bioremediation study indicates natural anaerobic bacteria are degrading VOCs;
FSR selected has feasibility and technological complications; and
cost (capital i«*4 operation & maintenance).
The OU3 ROD Amendment was public noticed (CERCLA 117) and subject to the public participation and
documentation procedures specified in. NCP 300.435(c)(2)(ii). The OU3 ROD Amendment will become
pan of the Administrative Record File [NCP Section 300.825(aX2)].
A complete and through history of the Site can be obtained by consulting the Kummer Sanitary landfill
Administrative Record File, which is available for public viewing at the Bemidji City Library, 6th and
Beltrami. Bemidji, Minnesota.
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EL Reasons for Issuing the OU3 ROD Amendment
The proposed Site remedy, described in the 1990 OU3 ROD. was an active downgradient hydrauiic
control and infiltration pond discharge and was to include:
five ground water extraction wells near uie eastern penmeter of the landfill:
pretreatment of extracted ground water with lime-soda to remove alkalinity and other inorganic
compounds (both leached from the landfill and naturally occurring);
handling and disposal of sludge caused by the precipitation of divalent ions of carbonate and/or
hydroxides and metals:
chemical treatment of the extracted ground water through an Advanced Oxidation Process (AOP).
which involves the addition of ozone, hydrogen peroxide and ultraviolet light:
discharge of the ground water effluent to an infiltration pond:
installation of two additional monitoring Wells near Lake Bemidji: and
long-term ground water monitoring.
In the 1990 OU3 ROD. the estimated present net worth for the AOP was given as $6.200.000. This
included S 1.370.000 for capital costs and $512.000 for annual operation and maintenance (O&M) costs.
The rationale for changing the remedy selected in the 1990 OU3 ROD is summarized as follows:
1. All affected receptors have been placed on the municipal water system installed in Northern
Township for OLJ1. Domestic wells in the area down gradient of the Site have been sealed and
abandoned according to code. The Minnesota Department of Health (MDH) has established a well
advisory or institutional control for the affected area to prevent potential new receptors. The MPCA,
through the State Attorney General's staff, has actively supported this effort
2. Quarterly ground water monitoring has shown a steady decrease in the contaminants of concern since
the low permeability cap was installed in 1991. The AOP was selected as the FSR in 1990, when
contaminant levels were significantly higher (Table 1). When the 1990 ROD was first developed,
there were 5 (five) compounds of concern: 1,1,2,2-tetrachloroethene, trichloroethene. trans-1.2-
dichloroethene. vinyl chloride, and benzene. Presently, only one of the five compounds, vinyl
chloride, is still detected in ground water downgradient of the landfill. Since the installation of the
low permeability cover and passive venting system, the level of vinyl chloride has been approaching
the cleanup goal or Maximum Contaminate Level (MCL) of 2 ug/1. This has been accomplished
without remediating ground water through the AOP. For example, in two wells at the bean of the
plume and immediately adjacent to the fill area (MW-3A and MW-12B), the concentrations now
detected are 7 and 3 ug/1 respectively. In comparison, the historic maximum concentration of vinyl
chloride detected in these wells were 20 and 94 ug/1 respectively (Figure 2). The only inorganic
compound found in elevated concentrations is barium. Figures 3 A and 3B graph the trend of barium
in the A and B horizon respectively. The Health Risk Limit (URL) for barium is only exceeded in
one monitoring well, MW-2A. The trend is fairly consistent in this well, however, it is directly
downgradient (approximately 100 feet east) of the area of the landfill that received the waste (boiler
ash) containing the barium. Since other downgradient monitoring wells are in compliance, the issue
of barium appears to be insignificant
3. There are technical and feasibility complications with the installation and operation of an AOP that
make it less desirable. First, the sludge generated by the system is likely to be hazardous and its
proper disposal would greatly increase the cost of O &M. Second, the hydrogeologic information on
the area immediately east of the Site does not support the ground water pumping rates necessary to
efficiently operate the AOP. Third, the treated ground water would have to be discharged to an
infiltration basin located near a protected seasonal wooded wetland. Changes in the local ground
water table due to infiltration may cause damage to this sensitive ecosystem. The only other
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alternative is a surface discharge to a pond on adjacent property which will increase costs due to
easement leases and National Pollutant Discharge Elimination System (NPDES) requirements
4. A two (2) year Bioremediauon Study conducted by the University of Minnesota for the MPCA has
determined bioremediation is a viable remedy for this Site to decrease the amount of vinyl chloride
below the MCL. There are naturally occurring methanotrophic bacteria in the soil and ground water
beneath and immediately east of the Site, which are degrading chemicals of concern under anaerobic
conditions. The Bioremediauon Study has concluded that injecting oxygen into the ground water
immediately east of the Site will allow naturally occurring aerobic bacteria to degrade the vinyl
chloride in the ground water to a level below the MCL.
5. The cost of installing and operating the AOP is very high in comparison to the remedy being
proposed as an amendment to the ROD. The estimated present worth of the AOP in 1990. was
$6.200.000 versus an estimated present worth of $575.000 for the remedy proposed in this
amendment.
nL Description of New Alternatives
Remedy proposed in 1990 OU3 ROD
The remedy selected in the 1990 OU3 ROD is described as an Active Downgradient Hydraulic Controls
and On-Site Infiltration Pond Discharge. Ground water would be collected in a series of pumping wells
located within the plume of VOC contamination. An on-site treatment facility would be constructed for
removal of organic compounds by AOP. Inorganic treatment (lime-soda softening) was to be provided if
banum concentrations exceed drinking water quality standards. Ground water with high concentrations
of inorganic contaminants may also involve managing a hazardous waste sludge. Treated ground water
would then be placed in an on-Site pond for recharge to the upper aquifer.
The area of clean up considered under this remedy includes the plume defined in Figure 4. Ground water
modeling (at the time of the 1990 OU3 ROD) indicated that sixty percent of the plume would be recovered
in 3.5 years but it would take 10 years before the plume would comply with MCLs. Since the treated
ground water would then be discharged into an on-Site infiltration pond, no NPDES permit is required.
Surface Water Quality Criteria (SWQC) are applicable to that portion of the plume which escapes the
pumping wells and is discharged as a nonpoint source into Lake Bemidji. The portion of the plume
which escapes the pumping wells would reach Lake Bemidji after approximately 36 years at
concentrations below SWQC. The pumped ground water would be treated to comply with MCLs prior to
discharge to the infiltration pond.
Treatment could continue from 4 to 30 years, depending on long-term effectiveness of the low
permeability cover system (OU2) in blocking future contaminant migration into ground water beneath the
landfill.
The applicable, relevant and appropriate requirements (ARARs). relevant for this remedy in 1990. include
MCLs and SWQC (Table 4). The concentration of treated ground water will comply with the MCLs.
Based upon ground water modeling at that time, the concentration of the portion of the plume, which will
escape the extraction system, would comply with SWQC when it discharges into Lake Bemidji. The
sludge produced from treatment of the inorganics may require management as a hazardous waste.
Total Cost of this Alternative: S6.200.000 (1990 present net worth dollars)
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Remedy proposed in OU3 ROD Amendment
The remedy being proposed as an amendment to the 1990 OU3 ROD is described as an Active
Downgradient Hydraulic Control with Insitu Leachate Containment by Subsurface Oxygen Addition
(ILC).
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The MPCA is proposing to install a pilot scale field demonstration of this remedy to fully evaluate insiru
biodegradauon of VOCs by oxygen addition to the plume area immediately east of the Site. The pilot
scale field demonstration is necessary to ensure that sufficient oxygen is made available and that the
oxygenated ground water is capable of achieving the complete breakdown of the contaminants of concern.
A full scale system will be installed after one year of operation if the field scale demonstration proves
effective at lowering concentrations of the chemicals of concern and the MCLs are not attained. Ground
water will be collected in a series of extraction wells located along the east side of the Site within the
plume of VOC contamination. A membrane oxygenator located in the extraction well will add oxygen to
the ground water. The oxygenated ground water will flow through buried lateral pipes to two (2) injection
wells located on each side of the extraction well (Figure 5) for injection back into the upper aquifer. The
pilot study will involve 11 wells (5 extraction wells and 6 injection wells). An oxygenator will only be
installed in one extraction well for the pilot project: a full scale system would involve placing an
oxygenator in all 5 extraction wells. The pilot study will have all 11 wells installed as a cost-savings
measure since there will be one mobilization/demobilization. Pilot study feasibility of the diffusive
capability of the oxygenated water can be assessed with the entire well system in place. Aerobic
biodegradation of the VOCs by naturally occurring bacteria in the ground water will effectively treat the
contamination (see Appendix B " Bioremediation Study of Leachate Contaminated Soil and Aquifer
Materials from Kummer Sanitary Landfill").
Based on historical ground water monitoring data, the area of cleanup as defined in Figure 4 has
diminished significantly in area! extent The only compound of concern detected, vinyl chloride, is no
longer present in monitoring wells MW-7A and MW-7B, MW-1 IB. MW-1A, MW-2A and MW-2B, and
MW-3C. This reveals that the plume has retracted from its original position and that it is breaking up
because of the absence of vinyl chloride in a few wells at the former bean of the plume. This has all been
accomplished in the past four years and suggests that the low permeability cover and the passive venting
system along with naturally occurring aerobic and anaerobic biodegration have all contributed to partial
remediation of the ground water.
Bioremediation may continue from 1 to 5 years, depending upon the long-term effectiveness of the low
permeability cover system (OU2) to reduce contamination from leaching into the ground water beneath
the Site. The bioremediation that is currently ongoing (that will be >»phan<^H with the ELC) has been
remediating ground water (aided by the low permeability cover and passive venting system) at a rate that
is accelerated from what modeling in 1990 suggested as stated previously. Evidence to show that
remediation is still necessary is provided by examining the graph of the behavior of ethyl ether (Figure 6).
Ethyl Ether has been detected in ground water beneath the site since 1986. It is a compound that behaves
like a conservative tracer in that it does not become adsorbed by the porous media but travels at the same
rate as the ground water. Figure 6 shows that a new plume containing ethyl ether at its leading edge was
detected at the Site in the Fall of 1994. The concentration gradient of ethyl ether during the Fall 1994
sampling round decreases as you move west toward the center of the landfill. The previous plume had
equilibrated during the past two years as can be seen by the consistent behavior of ethyl ether in all wells
prior to Fall 1994. The VOCs in the new plume do not represent an additional health threat but indicate
that leachate continues to be generated by the Site. For example, the HRL for ethyl ether is 1000
micrograms per liter and the levels detected are below the HRL (20-120 micrograms per liter).
The ARARs include the MCLs and SWQC (Table 4). The ground water subject to ELC will comply with
the MCLs. It appears that the leading edge of the plume is in equilibrium and has not moved farther than
monitoring well nest 18. This may be because ground water in this locality and downgradient of
monitoring well nest 18 is enriched in dissolved oxygen that is greater in concentration than that found
upgradient of the facility (Figure 7). These oxygenated wafers provide a natural aerobic environment to
continue bioremediating the ground water that was not remediated adjacent to the landfill. However, if a
portion of ground water escapes bioremediation it will comply with SWQC when it discharges to Lake
Bemidji. There will be no sludge or hazardous waste generated by this system.
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Lf the pilot scale remediates the ground water so that levels of vinyl chloride fall below the MCL for three
consecutive sampling events (samples collected quarterly) then the p
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J. Reduction of Toxkiry. Mobility, or Volume through Treatment
The remedies use different technologies for organic contaminant destruction and both reduce the toxicity
of the contaminants. However. ILC reduces both the mobility and the volume of the plume because
treatment occurs within the porous media. The oxygen is diffused into the porous media with link loss.
so more oxygen is available for the indigenous aerobic bacteria to consume and likewise break down the
contaminants in the leachate. In addition, since this remediation is taking place in the aquifer, the ground
water flow will transport some of the oxygen to a larger area and ensure a more thorough remediation of
VOCs. Since the AOP process occurs at the surface, the treatment of the contaminants takes place outside
of the porous media and is limited to the capture zones of the pumpout wells. In addition, AOP wastes
water (by treating contaminated water with natural background concentrations of many inorganics at the
surface), energy and chemicals used to remediate the extracted water.
5. Short Term Effectiveness
ILC could be installed and fully operational in one season (target date is Spring 1996). ELC would require
one year of pilot scale field demonstration to fully evaluate the system to measure performance, establish
operating parameters and evaluate its effectiveness. For this reason, only a portion of the plume will be
subject to treatment. It is expected that insitu aerobic biodegradation would begin very soon after oxygen
is added to the ground water with efficiency improving as aerobic bacteria populations increase. AOP
would take one construction season to install and require a longer startup/shakedown period because of
more complex equipment. The effectiveness of the AOP may not be known until after 1.5 years of
operation.
6. Implementability
While both remedies are considered implementable. ILC is technically and administratively easier to
implement than AOP. This is based upon design, construction and operational complexity; land
purchasing/leasing and permitting requirements.
ILC discharges right back into the ground water and as such would not be subject to NPDES permitting
requirements. However, a variance to Minn. Rules Chapter 4725 would be needed to install the 6
injection wells. The AOP design requires discharge into an infiltration pond. The infiltration pond would
have to be constructed on adjacent property and may have hydrogeologic ramifications on a nearby
seasonal wooded wetland. Because there would be a possible impact to an adjacent wetland, other
government agencies both on the state and federal level would have to review the design and a permit may
be necessary, which could delay the implementation process. The only other choice is to discharge to
surface water which would subject this remedy to the NPDES permitting requirement
7. Cost
The estimated capital, annual maintenance and monitoring and present worth value costs are evaluated by
this criterion. Present net worth costs are calculated using a 10 percent discount rate over the expected
penod of operation.
ELC AOP
199S Calculation 1990 Calculation
Construction Cost $50,000 $1.0 $1,400,000
Present Worth Cost $575.000 $1.8-$6.200,000
Annual O&M Cost $5.200 $240,000 - $510.000
The estimated costs for the AOP are in 1990 dollars, so the same remedy in 1995 dollars would cost even
more. A 20% percent contingency has been added to all the ILC costs since the technology is innovative.
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3 State Acceptance
The MFC A played a major role in the RI/FS process, construction of both OU1 and OU2. and supports
ELC. The MPCA will fund 100% of the remedy including O&M. The MPCA indicated in the original
1990 OU3 ROD that if in the future, bioremediation proved to be a reasonable alternative, the MPCA
would seek to amend the OU3 ROD.
MPCA believes that ELC - ground water extraction and treatment via insitu aerobic biodegradauon
presents the best balance among the nine criteria.
9 Community Acceptance
The public generally accepted AOP in the 1990 OU3 ROD. A public information meeting was held by the
MPCA on June 5. 1995. in Northern Township to inform interested parties on ELC and MPCA's desire to
amend the 1990 ROD. See Appendix A " Responsiveness Summary" for a detailed discussion of
questions and comments.
IV. The Significant Change With the Selected Remedy
ELC has been selected because it provides the optimum balance among the nine evaluation criteria in
1995. It is the most cost-effective, is quick to install and maintain is acceptable to the community,
provides overall protection of human health and the environment and complies with the ARARs. This
proposed new remedy is significantly different from the AOP chosen in the 1990 OU3 ROD. The primary
changes are as follows:
Insitu biodegnuiation of ground water contamination versus expensive, complex
exsitu chemical degradation.
Treated ground water is injected (below the ground surface) back into the
ground on-site versus reinfiltration through a basin or surface water discharge.
The remaining changes that will result from ELC are minor in nature.
V. Statutory Determinations
USEPA and MPCA believe that ELC satisfies the statutory requirements of Section 121 of the
Comprehensive Environmental Response. Compensation, and Liability Act of 1980 as amended by the
Superfund Amendments and Reauthorization Act of 1986 (CERCLA) to protect human health and the
environment, to attain ARARs, to be cost-effective, and to utilize permanent solutions and alternative
treatment technologies to the maximum extent practicable.
Protection of Human Health and the Environment ELC will reduce and control potential risks to human
health and the environment posed by exposure to contaminated ground water. This same remedy also
protects the environment by reducing or eliminating the potential risks posed by the Site chemicals
discharging to Lake Bemidji. In-situ biodegradauon will prevent trespassers and wildlife from coming
into contact with the contamination being treated at the Site. The access restrictions and required
maintenance will ensure the continued effectiveness of the treatment system. Even after the aerobic in-
situ biodegradauon of ground water by oxygenation is concluded, there will be continuing reduction in the
amount of contamination at the Site through naturally occurring aerobic and anaerobic degradation
because the reaction vessel is the aquifer. This would also be the case if the AOP system had been
installed and shut off.
Short-term impacts to nearby residents and workers at the Site during construction are expected to be
insignificant Air monitoring will be used during construction activities when emissions may occur.
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CLC will eliminate the amount of ground water that would have to be removed from the Site and
discharged. This will help prevent disruption of the existing nearby seasonal wooded wetlands and other
surface waters, which provide habitat for a variety of wildlife.
Attainment of Applicable or Relevant and Appropriate Requirements. ILC meets Federal and state
ARARs that have been identified. The ARARs and other criteria to be considered (TBCs) were indicated
in the 1990 OU3 ROD in Table 4 (Kummer Sanitary Landfill. Minnesota Comparison of ARARs and
other Criteria to be Considered for Organic Contaminants). However, since the 1990 OU3 ROD was
issued, some of the criteria cited have been updated. Those changes are:
The HRLs have been added as an ARAR (under the Ground Water pathway) because they are
promulgated drinking water standards set by the Minnesota Department of Health. The HRLs for the
chemicals of concern are: 1,1,2,2-tetrachioroethytene 7 micrograms per liter. 1.1.2-tnchloroethylene 30
micrograms per liter, trans- 1.2-dichloroethylene 100 micrograms per liter vinyl chloride 0.2
micrograms per liter, and benzene 10.0 micrograms per liter. Under the TBC Column the RALs have
been discontinued. This means that the only remaining chemical of concern which is vinyl chloride, will
have to meet a HRL of
0.2 micrograms per liter versus an MCL of 2.0 micrograms per liter.
ILC will satisfy all ARARs and will be protective of human health and the environment.
Cost Effectiveness. ILC has a distinct advantage in being much more cost effective than AOP treatment
system. The AOP would meet all of the threshold and balancing criteria but ILC will permanently and
reduce the contamination which is present at the site, and do so for a relatively small cost
Utilization of Permanent Solutions and Alternative Treatment Technologies to tne Ma*imu.ni Extent
Practicable. ILC provides the best balance of protectiveness. permanence, and cost ILC utilizes
permanent solutions and alternative treatment technologies to the maximum extent practicable. There are
no benefits that can be gained by installing the AOP sufficient enough to justify the extreme costs. Both
the AOP and ILC result in hazardous substances, pollutants, or contaminants remaining at the site, so a
review of the remedial action will be conducted no less than every five years. However, ILC has another
distinct advantage in that no potentially hazardous waste sludge will be generated.
Preference for Treatment as a Principal Element ILC will result in significant reduction in the remaining
amount of contamination at the Site. The naturally occurring anaerobic biodegradation in combination
with the low permeability cover and an improved passive landfill gas venting system, has already
significantly reduced levels of the chemicals of concern at the Site. Given the change in Site conditions
since the 1990 OU3 ROD was issued, ILC provides adequate treatment at a much lower cost.
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Kummer Sanitary Landfill
OU3 Record of Decision Amendment
List of Appendices
A. Responsiveness Summary
B. Executive Summary "Bioremediation Study of Leachate Contaminated
Soil and Aquifer Materials from Kummer Sanitary Landfill Site"
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Appendix \
Kummer Sanitary Landfill
Responsiveness Summary
A Proposed Plan in the form of a draft Record of Decision (ROD) Amendment Document was issued on
June 5. 1995. A public meeting was held on June 5. 1995. at the Northern Township Hall for the purpose
of presenting information on the proposed changes for the final site remedy and to answer questions and
receive public comment. Copies of the draft ROD Amendment were distributed to interested parties at the
public meeting and placed in the Administrative Record at the Benudji Public Library. A public comment
period was held from June 5. 1995. through July 6. 1995. The public meeting and comment period were
advertised in the Bemidji Pioneer and on the following radio stations: KBSB. KCRB and KKBJ
(Bemidji).
Several oral comments were received during the public meeting from members of the audience, a written
record of the proceedings and a sign-up sheet was kept, and this record has been made part of the
Administrative Record.
During the public comment period, no phone calls or letters were received concerning the Kummer
Sanitary Landfill..
In this responsiveness summary, the comments that were received during the public meeting on June 5.
1995. are being addressed. All comments being responded to here were considered by the Minnesota
Pollution Control Agency (MPCA) while making its final decision. The oral comments received are
paraphrased and then the response is presented.
I. Oral Comments
1. Comment (Audience). The Commenter asked how were we going to be sampling or monitoring the
bioremediation treatment system.
Response. The pilot scale field demonstration to determine feasibility of insitu bioremediation will be
monitored in several ways. First, the MPCA contractor will be regulating the oxygen level in the ground
water being reinjected to around 7-8 ug/1 or saturation. Oxygen and volatile organic compounds (VOCs)
will be monitored in existing wells along the east side of the site and immediately down gradient of the
treatment system in piezometers P-l and P-2.
2. Comment (Audience). The Commenter asked what purpose the "lagoon" served on George Hoffman's
property adjacent to the site.
Response. The "lagoon" is a sand borrow pit from when the landfill was covered in 1991 that has
since filled with water. The landfill cover required a large volume of intermediate fill material and it was
most cost effective to negotiate the sale of sand with the adjacent landowner than to truck material from a
distant source. The borrow pit is located west and up-gradient of the site and is not contaminated with
leachate from the landfill. A ground water monitoring well nest is located in between the "lagoon" and
the landfill and is free of contaminants.
3. Comment (Audience). The Commenter asked what came of the "plastic" barrier MPCA was going to
put around the landfill a few years ago.
-------
Response. The "plastic" bamer was a methane bamer trench which used a geomembrane on the far
wall of the trench to.prevem off-site underground migration of landfill decomposition gases (methane).
The bamer trench was not installed due to its high cost and tne fact that it could not be guaranteed to
work 100%. MPCA conducted extensive subsurface monitoring and decided to install a temporary
landfill gas extraction and flare system on the west side of the landfill in 1994. The landfill gas extraction
system removed all of the gas found off-site and continued monitoring has indicated little or no return to
previous levels in perimeter gas sampling wells. The MPCA has a long term landfill gas and ground
water monitoring plan for the Site. If landfill gas problems redevelop, the MPCA has a contingency plan
with a predesign ready to implement. As an additional precaution, methane alarms have been placed in
the Kununer residence and the nearby Alanon building.
4. Comment (Audience). The Commemer asked about landfill gas on the east side of the site.
Response. Perimeter gas sampling wells and additional monitoring have indicated that underground
migration of landfill gas is not a problem on the east side of the site. This may be due to the fact that
more demolition material was placed in this area of the landfill. If a problem develops over time. MPCA
will either add more passive vents on the east side or install a temporary gas extraction and flare system
similar to that used on the west side of the landfill.
5. Comment (Audience). The Commenter asked what hazard does vinyl chloride pose to people.
Response. Vinyl chloride is a known carcinogen. Therefore, drinking 2 liters a day for 70 years
would increase your risk of contracting cancer to 1 in 100.000. This is at the Health Risk Limit (URL) of
0.2 ug/1. The HRL is the drinking water standard promulgated by the Minnesota Department of Health
that applies to the groundwater supplies. The Maximum Contaminant Level (MCL) of 2ug/l has been
set by the U.S. Environmental Protection Agency and is the standard for cleanup at the site. Any level
above that standard is deemed unsafe in public drinking water supplies.
6. Comment (Audience). The Commenter stated that the Northern Township Planning Commission was
considering a request to rezone some of George Hoffman's property to the west of the site from
commercial to residential. It was not clear if this was property immediately adjacent to the Site.
Response. The MPCA has discussed the possibility of purchasing the lots which border the site as a
buffer area and holding them until such time as the landfill no longer poses a threat
7. Comment (Audience). The Commenter asked how long would it take before landfill gas is no longer a
problem.
Response. Studies indicate that the decomposition of organic matter which causes landfill gas
continues after "capping" with a gradual drop in methane generation over time. Estimates are in the
range of 15-20 years depending upon factors such as volume of waste, amount of organic material, etc.
However, landfill gas generation is very site specific as evidenced by sites closed in the 1970's still
emitting large volumes of landfill gas.
8. Comment (Audience). The Commenter asked what is the ground water quality at this time.
Response. Of the original chemicals of concern, only vinyl chloride remains at levels above the MCL
in monitoring wells down gradient of the site. There are inorganic contaminants from natural
biodegradation such as chloride and sulfate. While these inorganic contaminants are not found in
concentrations high enough to be of concern, they do alter ground water from its natural or background
quality. The HRL for inorganics is only exceeded in one monitoring well. MW-2A due to the presence of
barium. The trend is fairly consistent in this well, however, it is directly downgradient (approximately
100 feet east) of the area of the landfill that received the waste (boiler ash) containing the barium. Since
-------
other downgradient monitoring wells are in compliance and do not pose a health nsk. the banum problem
appears to be highly localized and of little significance. There are also low levels of metals present in the
ground water below the drinking water standard that are attributable to the landfill. The quality of the
ground water has obviously been changed by the landfill and even after reducing all the chemicals of
concern to levels below the MCLs. the quality of the ground water will not be the same for a very long
time.
9 Comment (Audience). The Commenter asked that the bioremediation oxygenation process be
described.
Response. The oxygenation process is the heart of the ground water treatment system being proposed
in the ROD Amendment. It involves extracting ground water immediately down gradient of the site
through a recovery well, diffusing pure oxygen into the ground water up to a level of 7-8 ug/1 or saturation
and then re-injecting the ground water back info the contaminated aquifer. The ground water that is
being extracted comes from an area of naturally occurring anaerobic or oxygen starved biodegradation.
That is to say, that all the available oxygen has been consumed by chemical reactions and bacteria. Only
those bacteria species that can tolerate an oxygen free environment are thriving. These anaerobic bacteria
are efficient at breaking down or mineralizing most contaminants but vinyl chloride is not degraded and
may well be a degradation by-product of other chemicals. By oxygenation of the ground water the level
of oxygen is increased and aerobic bacteria capable of degrading vinyl chloride are able to proliferate or
thrive. The goal is to stimulate enough aerobic bacteria to degrade the remaining vinyl chloride to levels
below the MCL.
10. Comment (Audience). The Commenter asked when people would be able to utilize their domestic
wells.
Response. The drinking water advisory/domestic well restriction is regulated by the Minnesota
Department of Health under advisement by the Minnesota Pollution Control Agency. If the water quality
in the aquifer improves in the future, a joint decision will be reached about domestic well utilization.
Currently, the level of contamination in the aquifer does not meet drinking water standards and leachate
continues to be generated from the fill area. In addition, not every portion of the aquifer is monitored so a
guarantee of a safe drinking water supply can only be assured through utilization of the municipal
system.
-------
fl^-:,,.-^-^--:,
I usi -. /. ~ ^rrr^~
;.m-jv,^M^'.;
£%f^!l
;:-.i ^pr^^^a
i: :)..-
:'l
SANITAIIYli:.'.-
HUM UUMIDJI WEST (1968} AND PEIEMSOM
i -r i (1912) I I/] MltlUIE IISGS
Mll-.H.IIAI'lllC UUAUIIAIICLES
\i\iroiM
I'IMMII
KUMMER LANDFILL
-------
TABLE 1
KUHMER SANITAfir LANDFILL, HINNESOTA
VOLATILE* FOUND IN GROUND WATER PRIOR TO 1986
Lowes;
Methylene Chloride
IJ-Dichloroethane
l-2-Dich1oroethy1ene (total)
], 1,2-Trichloroethane
Trichlorofluoromethane
1, 1-Oichloroethylene
l-2,Dichloropropane
Vinyl Chloride
Chloromethane
Dichlorofluoromethane
Bromomethane
1,2-Dichloroethane
1,1, 1 -Trichloroethylene
Dichlorodifluoromethane
Acetone
Ethyl Ether
Benzene
Toluene
Total Xylenes
Tetrahydrofuran
Ethyl Benzene
1 , 1 ,2,2-Tetrachloroethylene
Chloroform
Chloroethane
1. 1,2,2, -Tetrachlorethane
1,2-Dibromomethane
Bromodichloromethane
1,2-Dibromoethane
Trichloroethylene
Methyl Isobutyl Ketone
1,1-Oichloro-l- Propane
1.0
0.3
0.2
0.2
0.2
0.2
0.2
*
*
*
*
0.1
0.2
*
16.0
0.1
0.3
0.5
0.6
0.5
0.5
2.0
0.2
*
2.0
0.4
0.2
0.4
0.2
5.0
0.2
46.0
5.4
27.0
2.7
5.6
1.7
1.7
*
*
*
*
4.2
3.8
*
100.0
60.0
3.1
6.8
8.2
130.0
8.0
16.0
2.4
*
4.6
0.7
0.7
0.7
2.8
6.0
1.8
All values in micrograms/1iter.
* If no Lowest-Highest value is given, the volatile organic compound was
detected as a peak below the detection level.
-------
Figure 2: Concentration versus time tor vinyl chloride in wells at Kummer Landfill
1
0>
Q.
1A
£
e
1"
u
i
c
c
o
3
I
u
§
u
100
90
80
70
60
50
40
30
20
10
0
\
\
X
\
X
X
\
X
X
X
X
X
X
X
x A
X /"
*'
A . _ ^ *
~"^"~"----AD--.0 ' *" " ^ -^ ---6~ ' ^s, ^A
O * m-^--^^^-^ ^^.ff" -ft '-f: ' *
1 - 1 - -...(-. i -;- o i
12/23/88 5/7/90 9/19/91 1/31/93 6/15/94 10/28/95
- - MW-3A
- A- MW 12D
- - o - MW-18B
- A- -MW-1B
Date
Prepared by GWSW Staff 7/26/95
-------
Figure 3A: Barium trends in groundwater around Kummer SLF, SW 31, at the walur tablu
ff
t»
8
u
E
3000
2500
2000
1500
o
1
g ' 1000
u
O
U
500
HRL
MW IA
MW 2A
--MW 3A
--MW 5A
-*- MW 7A
--MW 8A
--MW 1 1A
MW 12B
MW I9A
- MW 20A
12/23/88
5/7/90
9/19/91
1/31/93
6/15/94
1O/28/96
Date
Prepared by GWSW Slalt 7/26/95
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Figure 3B: Barium trends in the B horizon around the Kummer SLF, SW-31
6000
5000
8. 4000
M
c
3000
8
o
U
2000
1000
HRL
6/11/91 12/28/91 7/15/92 1/31/93 8/19/93 3/7/94 9/23/94
Date
* MW 10
--MW 2B
MW 38
H MW i>B
-»-MW VB
--MW I IB
« MW I!3B
4/11/95 10/28/95
Prepaied by GWSW Slad 7/26/95
-------
ArrMOHIMAT f.
LU«
IION
^^kwtrf iiU / Q
O ^ I3y
v^_ s
^«-
I- MONTH COUNTRY »OS<
NOSri T At il N 1
TCR
a
/i
|-
VI
u
<
O
**i
so
9 ~~
\
o
15
0
O
«O3£
1
I IB
* o
a
«
O
T
i
i
r
_/
>
a
4
~t
5
i
LILAC 01.
O
O * ONLY
A A ONI. Y
CXTtNT OF VINYL CNLOMIOE PLUME
A ZONE
B ZONE
TMt C ZONE ! ALSO INCLUDtD AT VffLL LOCATION I
VINYL CHLORIDE. DCE. AND I'C E WEHE ALSO UtltCltO IN :, /
ROUND 8 AT WELL LOCATION 10 U
KUUMCM LANOfILL OAOONO WATER FEASIBILITY STUDY
-------
TABLE 4
KUMER S A N I I A R r I A NO F I I I . MINNESOTA
COMPARISON OF ARARs AND OtHER CRITERIA
10 BE CONSIDERED FOR ORGANIC CONIANINANIS
Palhuay
Contaminant
AHAKs
IBC
Ciuund Water
Rang* Detected Cleanup level
MCI PMC I. MCLC
Ug/l
DAI s
10
* D I i.l
Surface Uater
Air
Notes:
NA
SUQC
iec
MCLi
RAls
I0'5,10"6
CA Risk
NPDES
AUQC
uv
MAAQS
<,OCFR-268
UUi
11 I C
HIA
.ul'A
1. 1.2,2 tetrechloroethylene (PCE) 1.0-12
1,1,2-trtchloroethylene (ICE) 1.0-6.8
trans-1.2-dicMoroethylene (tOCE) (.1-15
vinyl chloride 5.9-94
benienc 1. 0-6.0
1, 1,2.2-tetrachloroethylene (PCE) NA
1,1.2-trlchloroethylene (ICE) NA
trans- 1 ,2-dichloroethylene (tDCE) NA
vinyl chlorine MA
benttne MA
NAAQS
1.1.2,2-tetrchloroethylene (PCE) MA
1,1,2- trlchloroethylene (ICE) NA
Irani- 1,2-dicMoroethylene (tDCE) NA
vinyl chloride NA
beniene NA
= Not Available
5 5-0
5 i 0
100 100* 100
2 20
5 5 0
" MPDES-Chronic SMOC
9 9
123 121
449 449
1.1 J.I
58 18
> MPCA Surface Uater Quality standards for Lake Bemidji and the Mississippi River (Minnesota Rule
Other criteria to bt considered
Safe Drinking Uater Act Maximum Contaminant Level*.
Hlnneaota Department of Mealth Recommended Allowable L lulls
(1988).
6.6 1 .7 6
Jl 7.8 11
ro \r M>
0.15 0.057 20
r i 6. .
ug/L AUQC fuas
0.8 6.9
2.7 120
NA 51)
2.0 J.e.
0.66 JO
> CuiiLCt K .b
Uy/roJ IX II v 10'' d '''
1550 i..i (.1
2^00 1.5 . . 15
NA NA M
100 0.28 I . il?8
100 0.27 i .u^^
7050).
Minnesota Rules iiUed Municipal solid waste landfill ground water performance intervention limits (7015.2815 Subpsrt <. > .
Concentration correspondence to lifeline incremental cancer risk of 10~5 or to'6 (ground water number Iron EPA 440/V8A 001 uSti'A
quality criteria for water 1986).
National Pollutant Discharge Elimination System (also Minnesota Rules Chapter 7001 and Minnesota
USEPA Amblant Uater Quality Criteria-drinking water and fish consumption (10 6 increment cancer
threshold limit Value uork-shift time-weighted average.
National Ambient Air Quality Standard
Land ban on dlapoaal of untreated and certain liquid wastes
discussion of ARARt In Section KB).
in land-based woite management units
Statutes Chapter 115 and 116).
risk).
may be applicable fo< inurg&iuc nltt. ..jt- v .
« Proposed Uater Quality Standards for Lake Bemidji and the Mississippi River.
> Maximum Contaminant limit Coalt
t Proposed Minimum Contaminant levels
« NPOES Permit required only for A'-irnate II. NPDES requirr
Minnesota Crounrt Wat^r Drn»--«;
ts un
-------
return lines to injection wells
1
3 ft deep
water table
Figure 5 A side elevation showing the way in which water is drawn from the.
center suction well (2) and returned to the injection wells (1). The suction well is
equipped with a well pump and oxygenator.
-------
Figure 6: Behavior of Ethyl Ether downgradient of Kummer SLF
140
120
£ 100
t.
0
a
m
01
o
80
6O
a>
c 40
o
u
20
O
-»- MW 1U
--MW 2A
MW 3A
-M-MW-7A
-H»-MW 8A
--MW 128
« MW 1 XA
MW 1 7B
12/28/91 7/15/92 1/31/93 8/19/93 3/7/94
Date
9/23/94
4/11/95
10/28/95
Prepared by GWSW Slaft 7/26/95
-------
Figure 7: Dissolved Oxygen on October 18, 1994
Dissolved Oxyiju-n;
MW 19A
18A
MW-
5A
MW-
5C
MW-
1B
MW-
3A
MW-
12B
MW-
7B
MW
13A
MW
14A
MW-
15B
MW-
17A
MW-
19A
Well
------- |