United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
PB93-964110
EPA/ROD/R05-92/211
September 1992
&EPA
Superfund
Record of Decision:
La Grande Sanitary Landfill,
MN
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EPA Report Collection
Information Resource Center
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Philadelphia, PA 19107
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NOTICE
The appendices listed in the index that are not found in this document have been removed at the request of
the issuing agency. They contain material which supplement. but adds no further applicable information to
the content of the document. All supplemental material is, however. contained in the administrative record
for this site.
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50272-1 01
REPORT DOCUMENTATION 11. REPORT NO. . I ~ 3. Recipient. Acces810n No.
PAGE EPA/ROD/R05-92/211
4. ThIe and Subdlle 5. Report 0818
SUPERFUND RECORD OF DECISION 09/30/92
La Grande Sanitary Landfill, MN
6.
First Remedial Action - Final
7. AuIhor(8) 8. Performing Organization RepL No.
9. Performing Orgalnlz8tlon Name 8Id Addrea 10. ProjectITaakIWork Unit No.
11. Contrac1(C) 0. G'8It(G) No.
(C)
(G)
1~ Sponaoring O.ganlzadon Name end Add... 13. Typo 01 Report & PerIod Covered
U.S. Environmental Protection Agency 800/000
401 M Street, S.W.
Washington, D.C. 20460 14.
15. Supplementary NoI88
PB93-964110
16. Ab8tr8cI: (Umlt: 200 worda)
The 80-acre La Grande Sanitary Landfill site is located in west-central Douglas
County, Minnesota, 5 miles west of the town of Alexandria and 3 miles south of the
town of Garfield. The main fill area occupies 6 acres of a small, north-trending
gully, which is surrounded by forest, steep uncultivated hills, and low lying
wetlands. A sand and gravel water table exists under a portion of the site, and
residents downgradient are using the aquifer for drinking water. From 1974.to 1984,
the landfill was in operation and accepted mixed municipal solid waste and
nonhazardous industrial wastes. In 1982, a state ground water investigation revealed
the presence of low level organic compounds. The landfill was closed in 1984, and a
final cover was installed in accordance with state regulations. Sampling during the
RI revealed that only one contaminant, manganese, was found in high levels in the Old
Shop Well onsite, which required action to reduce the potential risk of exposure.
This ROD addresses a final remedy for the site and addresses the onsite landfill and
ground water. These primary contaminants affecting the soil, debris, and ground water
are organics, including bis (2-ethylhexyl) phthalate; and metals, including manganese.
.
(See Attached Page)
17. DocumentAnalysl8 L DeacrlptDn
Record of Decision - La Grande Sanitary Landfill, MN
First Remedial Action - Final
Contaminated Medium: soil, debris, gw
Key Contaminants: organics (bis(2-ethylhexy1)phthalate), metals (manganese)
b. Idontlflor8lOpen-Endod T eml8
c. COSATI FleWGroup
18. Avall8blHty Sl8t8ment 19. Security CI8a (TII18 Report) 21. No. 01 Pogea
None 34
20. SecurIty CI8a (ThI8 Page) ~ PrIce
None
272 (4.77)
(See ANSI-Z39.18)
See ln817uct1o". OIl R-
(Formerty Nf1S.35)
Department 01 Commerco
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EPA/ROD/R05-92/211
La Grande Sanitary Landfill, MN
First Remedial Action - Final
Abstract (Continued)
The selected remedial action for this site includes long-term monitoring of ground water
and combustible gas; converting a gas monitoring well to a gas vent to control the
accumulation of explosive gases; sealing off and abandoning the onsite Shop Well to
ensure that it will not be used as a potable water source, stabilizing the west slope of
the landfill, and covering the exposed landfill waste on the northwest corner with a soil
cover; sloping and reconstructing the borrow pit area adjacent to the west slope to
ensure long-term integrity of the existing cover system; restricting site access and
implementing institutional controls, including deed and ground water use restrictions.
The estimated present worth cost for this remedial action is $501,000, which includes an
annual O&M cost of $22,000 for 30 years.
PERFORMANCE STANDARDS OR GOALS: Chemical-specific ground water clean-up goals were not
specified. Because of the low level risks posed by the site, treatment of onsite media
is not considered necessary.
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DECLARATION OF THE RECORD OF DECISION
LA GRANDE SANITARY LANDFILL
DOUGLAS COUNTY, MINNESOTA
site Name and Location:
La Grande sanitary Landfill Superfund site, La Grande Township,
Douglas County, Minnesota
statement of Basis and Purpose:
This decision document presents the final remedial action for the
La Grande Sanitary Landfill Superfund Site (the Site) which was
chosen in accordance with the comprehensive Environmental
Response, compensation, and Liability Act of 1980 (CERCLA), as
dmended by the Superfund Amendment and Reauthorization Act of
1986 (SARA), and to the extent practicable, the National
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.
This decision is based upon the reports, information and public
comments which constitute the Administrative Record for the site.
Assessments of the site:
Actual or threatened releases of hazardous substances from the
Site, if not addressed by implementing the response action in
this Record of Decision, may present imminent and substantial
endangerment to public health and welfare, or the environment.
Description of the Selected Remedy:
1.
long-term monitoring of groundwater and combustible gas
to verify that the low level of threat posed by the
contaminants of concern remains low and that the
landfill does not generate potentially explosive levels
of combustible gas;
2.
the conversion of a combustible gas monitoring well to
a gas vent to assure that combustible gas does not
accumulate at the single point where the soil gas level
was measured at greater than 100% of the lower
explosive limit (LEL);
the permanent sealing and abandonment of the on-site
Shop Well in conformance with the Minnesota Water Well
Code, Minn. Rules, Chapter 4725.2700, to assure that
. this well will not be used as a potable water source;
3.
4.
the stabilization of the west slope of the Landfill and
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the covering of exposed waste on the northwes~ corner
to assure that the existing landfill cover, Nhich is
providing an effective barrier to infiltration, remains
effective;
5 .
the sloping and reconstruction of the borrow pit area
adjacent to the west slope of the Landfill to assure
the long-~erm integrity of the cover system;
6.
institutional controls in the form of site access
restrictions, and the possible use of deed
restrictions;
7.
maintenance of the existing final cover system so as to
reduce the future potential for infiltration into the
waste mass and the subsequent leaching of contaminants;
8.
observance of Minnesota Environmental Response and
Liability Act prohibitions against the disturbance of
the Landfill final cover and monitoring sys~ems; and
9.
observance of the Minnesota Water well Construction
Code, Minn. Rules Chapter 4725.2000, which regulates
the location of future potable wells near the Landfill.
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 final remedial action, and is cost-effective and utilizes
permanent solutions and alternative treatment or resource
recovery technologies to the maximum extent practicable. The
preferred alternative will not satisfy the statutory preference
for treatment as a principal element since treatment is not
considered necessary due to the low level of risk posed by site
contaminants.
Because this remedy includes monitoring components which would
verify that the low level threats posed by the site do not
increase above health-based levels, a review of monitoring data
will be conducted within five years after the commencement of
remedial action to ensure continued protection of human health
and the environment.
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Federal and state Concurrence:
The united states Environmental Protection
Minnesota Pollution Control Agency believe
remedy is the best choice balancing all of
criteria required by CERCLA.
Charles Williams
Commissioner
Minne~ota Pollution control Agency
. /ai:Z;/ /r 11114/
Valdas V. Adamkus
L Regional Administrator
{I,'~u.s. Environmental Protection Agency
Region V
~d2--
Agency and the
that the selected
the nine evaluation
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Federal and state Concurrence:
The United states Environmental Protection
Minnesota Pollution Control Agency believe
remedy is t~est choice balancing all of
. cr/t;;;£;2"
cb~iams
Commissioner
Minnesota Pollution Control Agency
Agency and the
that the selected
the nine evaluation
Valdas V. Adamkus
Regional Administrator
U.s. Environmental Protection
Region V
Agency
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I.
II.
DECISION SUMMARY
LA GRANDE SANITARY LANDFILL
DOUGLAS COUNTY, MINNESOTA
SITE NAME, LOCATION AND DESCRIPTION
The La Grande sanitary Landfill (the Site or the Landfill)
is located in a rural setting in west-central Douglas
County, Minnesota (Attachment 1), approximately 5 miles west
of the town of Alexandria and approximately 3 miles south of
the town of Garfield (Attachment 2). The Site consists of
80 acres of forest, steep uncultivated hills and low lying
wetlands. The main fill area occupies six acres of a small
north-trending gully formed during earlier gravel mining
operations (Attachment 3). It is marked to the north, west
and east by groups of large trees.
The Site is located within an area of glacial deposits known
as the Alexandria Moraine Complex. This moraine complex is
10 to 20 miles wide and extends northward in an area through
west-central Minnesota. The upper 100 feet of sediments
beneath the Site consist of glacial drift deposits of the
moraine complex. A sand and gravel water table aquifer
exists under a portion of the Site, and is overlain by a
silty to sandy clay till layer which was found to range in
thickness from approximately 15 to 40 feet. The sand and
gravel aquifer extends beneath the Landfill waste mass. At
other portions of the Site, the till layer extends to a
depth of at least 100 feet. The water table was found at
depths ranging from approximately 20 to 70 feet below the
surface of the hilly terrain at the Site.
SITE HISTORY AND ENFORCEMENT ACTIVITIES
The site operated from March 1974, when it received a solid
waste permit from the MPCA (SW-141), until April 1984, as a
sanitary landfill accepting mixed municipal solid waste and
nonhazardous industrial waste. In late 1982, and early
1983, groundwater sampling at the site confirmed the
presence of organic compounds. Subsequent investigations at
the site led the Minnesota Pollution Control Agency (MPCA)
to evaluate whether the site should be included on the
National Priorities List (NPL) and Minnesota's Permanent
List of Priorities (PLP) for superfund sites potentially
requiring clean up. The Site was added to the NPL and PLP
in June 1987, with a Hazard Ranking System score of 34.
In July, 1987, the MPCA issued a Request for Response Action
to Francis C. Cosgrove, Marlin F. Torguson and Valley
Disposal Corp. as owners and operators to perform a Remedial
Investigation/Feasibility Study (RI/FS) at the Site. In
August, 1987, the MPCA issued a Determination That Actions
Would Not Be Taken In The Time And Manner Requested to the
same three parties. The issuance of a Determination That
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2
Actions will Not Be Taken In The Manner And Time Requested
allows the MPCA to perform necessary investigatory and
response action activities at the Site using either the
State or Federal Superfund.
III. HIGHLIGHTS OF COMMUNITY PARTICIPATION
The Superfund activities at the site have been followed
closely by the local community and press. To date, public
meetings have been held and the MPCA has published fact
sheets, update letters, and issued press releases regarding
response activities associated with the site. Local
citizens interested in the activities occurring at the Site
are informed of major events by the MPCA, in consultation
with the u.S. EPA. A chronology of past community relations
activities at the site is listed in the Responsiveness
summary (Attachment 10).
A public information repository has been established in the
Alexandria Public Library, 117 Seventh Avenue West,
Alexandria, Minnesota. The public information repository
contains the Administrative Record for the site. The
Administrative Record consists of all documents, including
public comments, which u.S. EPA and MPCA reviewed in
selecting the remedy for the site (Attachment 11). The
Administrative Record is also located at the MPCA's main
office in st. Paul, Minnesota and at the U.S. EPA offices in
chicago, Illinois. . .
Notice of availability of the Proposed Plan for the site for
review by the public was published in the Lake Region Echo
Newspaper in the form of a display ad on August 14 and
August 16, 1992. This ad initiated a thirty (30) day public
comment period beginning on August 17, 1992. The public
comment period is consistent with the requirements of the
comprehensive Environmental Response, compensation, and
Liability Act (CERCLA), Section 117 (a). Notice of a public
meeting was included. Additionally, a Fact Sheet providing
notification of the proposed remedy and public meeting was
sent to interested parties and the press.
A public meeting was held on September 2, 1992, where the
MPCA and u.S. EPA presented the alternatives to a group of
interested citizens. The Responsiveness summary (Attachment
10) addresses specific comments raised at the September 2nd
public meeting and during the public comment period. The
public comment period officially ended on september 15,
1992. No formal request for an extension of the comment
period was received by the MPCA or the u.S. EPA.
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IV.
3
SITE CHARACTERIZATION
The work a~ the site involved determining ~he nature and
extent of contamination during the RI and developing and
evalua~ing remedial (cleanup) alternatives during the FS.
The RI Repor~ concluded that:
:.J
Groundwater moves beneath the site in a south-
southeasterly direction.
.:)
Although a number of organic contaminants were measured
in. soil and groundwater at the Site, no organic
contaminant plume was identified and none of the
measured compounds exceeded current health-based
standards or u.s. EPA's acceptable risk range.
o
Arsenic and manganese were found in the groundwater at
concen~rations exceeding Minnesota Recommended
Allowable Limits (RALs) for private drinking wa~er
supplies, but not Maximum contaminant Levels (MCLs)
under ~he Federal Safe Drinking Water Act (SDWA).
These naturally-occurring heavy metals were widespread
throughout the site and had the appearance of random
background concentrations. The on-site Shop Well
showed manganese levels elevated above background
levels. However, these levels were not considered to
be rel~ted to landfill waste disposal activities.
. ..w..;..~
o
Manganese was found in surface water at concentrations
that exceeded RALS in nearly all water bodies, both
upgrad1ent and downgradient of the Landfill and
regardless of whether surface water drains away
toward the water bodies. The manganese appears
derived from natural sources in the soils, with
evidence of a source from the Landfill.
from or
to be
no
~
o
A chlorjde plume appears to be emanating from. the
southern end of the Landfill and migrating south-
southeastward. Chloride is one of the most mobile
contaminants associated with landfills. It is not a
hazardous substance and occurred in concentrations well
below the SDWA secondary MCL. This standard is not
health-based, but determined on. the basis of taste,
odor, and aesthetic considerations. .
o
There does not appear to be any combustible gas
migration from the Landfill, except for a single
monitoring point at the southwest corner, where the
combustible gas reading was greater than 100% of the
Lower Explosive Limit (LEL).
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v.
4
o
Portions of the western slope of the Landfill appear
unstable and the northwest corner of the waste mass has
been exposed by hillside erosion.
o
Access to the site by motorized vehicles via the main
access road was not controlled.
o
A pile of several hundred tires is located to the south
of the Landfill, off the .fill area. These tires will
be addressed by the MPCA's tire control program.
The FS Report utilized the results of the RI to develop
potential cleanup alternatives designed to address the low
level threats posed by the site.
SUMMARY OF SITE RISKS
Part of the RI for the site involved conducting a baseline
risk assessment, which is intended to measure the potential
current and future risks posed by chemicals of concern at
the Site. The risk assessment evaluates both human health
and environmental risks.
Human Health Risks
The human health risk assessment evaluates potential
carcinogenic, or cancer-causing risks, and noncarcinogenic
risks to human health. Noncarcinogenic risks include such
risks as .the potential to cause liver damage and
reproductive abnormalities. Furthermore, the risk
assessment requires that all complete contaminant exposure
pathways be evaluated. Such pathways include, but are not
limited to: Direct skin contact with or ingestion of
contaminated soil, surface water, and groundwater;
inhalation or absorption of contaminants during washing,
showering, or bathing; and inhalation of airborne
contaminants from the site.
Air sampling performed during the RI indicated that exposure
to soil or air emanating from the site does not pose any
major health risks. The only pathways of concern identified
in the human health risk assessment, which all relate to the
use of groundwater downgradient from the site, are:
o
ingestion of contaminated groundwater by drinking or
cooking;
o
inhalation of chemicals that can volatilize into the
air during showering; and
o
dermal (skin) contact with water during showering,
bathing and other related activities.
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5
Finally, the human health risk assessment assumes a
reasonable maximum exposure (RME) scenario. This means that
it takes into account the highest concentration of each
chemical to which adults and children are reasonably
expected to be exposed during an average lifetime at the
Site. At present, there is no one living on or using the
groundwater at the Site nor do residential wells
downgradient of the Site show any contamination from organic
compounds. Thus, this scenario represents a conservative
approach in calculating potential future risks.
The chemicals of concern evaluated in the human health risk
assessment were chosen based upon how often they were
detected and at what levels, upon their inherent toxicity,
and upon how likely it is that adults or children would come
into contact with them. Using these criteria, the chemicals
that were chosen for the human health risk assessment were
the metals arsenic and manganese and the semi-volatile
compounds bis (2-ethylhexyl) phthalate, butyl benzyl
phthalate and di-N-octyl phthalate.
The determination of carcinogenic risk is based upon
calculating how much of an increased risk a chemical poses
over the average or "background" level. For the general
population, the background risk is about one in three, or 33
percent, of developing some form of cancer in one's
lifetime. The range of increased cancer risk that U.-S. EPA
considers acceptable is a range of one in ten thousand to
one in one million. within this range U.S. EPA may consider
taking action to reduce carcinogenic risk on a site-specific
basis.
The results of the human health risk assessment indicate
that the total potential increased cancer risk from the
possible exposure of residents to groundwater at the Site is
about nine in one hundred thousand for adults and four in
orie hundred thousand for children (Attachment 4). These
risks are within U.S. EPA's acceptable risk range and are
largely attributable to arsenic in the groundwater.
Arsenic is naturally occurring throughout the area and- the
RI indicated that the Landfill did not appear to be a source
of arsenic. For this reason, and because the increased
carcinogenic risk falls within U.S. EPA's acceptable range,
groundwater remediation for arsenic at the Site is not
warranted.
The determination of noncarcinogenic risk is based upon the
calculation of a term called the Hazard Index. If the
Hazard Index for a risk pathway is less than 1,
noncarcinogenic risk is not expected at the Site. A Hazard
Index greater than 1 represents a potential for the
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6
occurrence of noncarcinogenic health risks.
Total pathway Hazard Indices for the possible exposure of
residents to groundwater are 1.8 for adults and 4.2 for
children, indicating that ingestion of groundwater on-site
presents a potential concern for noncarcinogenic health
effects (Attachment 5). This concern is largely due to the
presence of manganese in the groundwater and is based
largely on manganese levels measured in the old Shop Well.
Thus, manganese is the only groundwater contaminant which
warrants taking action to reduce potential health risks from
exposure to groundwater.
The cause of the high manganese levels in the Shop Well is
not known. Manganese, like arsenic, occurs naturally
throughout the area and, based upon the results of the RI,
the Landfill does not appear to be the source of elevated
manganese levels. However, because the Shop Well is the
primary location where manganese levels were measured
significantly above background, and represents the bulk of
the noncarcinogenic risk at the site, it will be permanently
sealed and abandoned in accordance with the requirements of
the Minnesota Water Well Construction Code, Minn. Rules, Ch.
4725.
As previously indicated, air sampling performed during the
RI indicated that exposure to air emanating from the site
does not pose any major health risks. In addition to' the
air sampling, the Landfill was also monitored for the
generation of combustible gas (largely methane), which is a
common occurrence at landfills over time.
The human health risk assessment was not intended to address
the potential for the buildup of combustible gas at the
Landfill. However, because combustible gas (largely
methane) is expected to be generated at the Landfill over
time, it will be monitored as part of the selected remedy.
In addition, because a single combustible gas monitoring,
point indicated a combustible gas reading greater than 100%
of the Lower Explosive Limit (LEL), it will be converted to
a gas vent so as to eliminate the potential for the buildup
of combustible gas at that point. This is in accordance
with requirements at Minn. Rules Chapter 7035 for Mixed
Municipal Solid Wastes.
Environmental Risks
The.environmental assessment is based upon surface water and
sediment samples collected at the site and an ecological
survey of the area. Because of the complexity involved in
ecological analyses and the lack of species-specific
toxicity data, it is not possible to perform a quantitative
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VI.
7
risk assessment for the environmental effects of most
chemicals. Therefore, this assessment is more qualitative
in nature, and based upon general observations of the
surface waters, sediments, plant, and animal life at the
site. As a guide, measured concentrations of chemicals in
surface waters and sediments at the site are compared to
available standards, such as surface water criteria, when
performing the evaluation.
The chemicals of concern evaluated for their environmental
risk potential were the metals copper, lead, and zinc and
the plasticizer bis (2-ethylhexyl) phthalate. Based upon
exceedances of surface water'quality criteria, copper and
lead pose a moderate risk to wildlife and zinc poses a
moderate to high risk.
Like arsenic and manganese, these metals are common
throughout the area. Background samples for these metals
taken upgradient of the site exhibited concentrations in the
same range, and sometimes higher than, on-site downgradient
samples. Furthermore, there appears to be no direct
interconnection between the groundwater at the Site and the
sediments and surface waters. Therefore, no further
consideration of surface water and sediment remediation is
warranted.
The risk posed by bis (2-ethylhexyl) phthalate is considered
negligible since it was detected at a very low level in one
upgradient surface water sample. The risk assessment
concluded that, overall, the quality of the environment
around the Landfill appears to be good and the remediation
of surface water and sediment is not warranted.
DESCRIPTION OF ALTERNATIVES
The Feasibility Study for the Site was written in accordance
with EPA's Interim Final Guidance for Conductina Remedial
Investiaations and Feasibilitv Studies Under CERCLA (OSWER
Directive 9355.3-01). EPA guidance requires that different
cleanup technologies be evaluated and combined into various
remedial alternatives. The resulting alternatives must then
be developed and screened, with the most promising
alternatives retained for detailed analysis. Based upon
this review process, the following three alternatives were
retained:
Alternative 1:
No Action
The. No Actiqn alternative consists of leaving the site
conditions as they currently exist. No long-term actions
are included in this alternative and it provides no
additional protection of human health or the environment.
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8
Evaluation of the No Action alternative is required by the
National oil and Hazardous Substances contingency Plan (NCP)
as a "baseline" alternative for all Superfund sites.
cost of Alternative 1:
$0
Alternative 2: Lona-Term Monitorina of Groundwater and
Combustible Gas. A Gas Vent Well. and the Permanent Sealina
of the On-site Shop Well
The intent of Alternative 2 is to monitor future potential
public health and environmental risks at the Site.
continued monitoring will be necessary to verify that
current low level risks do not increase in the future. Its
purpose will be to detect changes in groundwater contaminant
concentrations and combustible gas concentrations which may
indicate increased health risks related to the Landfill, and
may indicate that additional remedial activities are
necessary. In addition, an existing combustible gas well
will be modified to a gas vent in order to mitigate
combustible gas that may accumulate. This will be
accomplished by venting the gas well to the atmosphere.
Finally, the on-site Shop Well will be permanently sealed in
accordance with the Minnesota Water Well Construction Code,
Minn. Rules Chapter 4725.2700.
Annual ins~tion and maintenance to assure the integrity of
the existing cover vegetation, removing woody vegetation,
such as tree5!., and repairing eroded and/or subsided areas
will be conducted in conjunction with the monitoring
program. site access will be controlled by means of a
locking gate at the only road entering the facility, as well
as the posting of "No Trespassing" signs. Institutional
controls, such as deed restrictions to notify potential
. buyers of the property of the situation at the Site, may be
obtained. TRe Minnesota Water Well Construction Code, Minn.
Rules Ch. 4i~5.2000, Subp. 2. regulations regarding the
installation of potable wells near landfills will apply.
. Cost of Alternative 2:
capital Cost $ 73,000
Annual O&M Cost $ 22,000
30 Year Present Worth at a 10% Discount Rate $279,000
Alternative 3: Lana-Term Monitorina of Groundwater and
Combustible Gas. A Gas Vent Well. the Permanent Sealina of
the On-site Shop Well and Slope Stabilization
Alternative'3 includes all of the elements of Alternative 2.
continued monitoring will be necessary to verify that.
current low level risks do not increase in the future. Its
purpose will be to detect changes in groundwater contaminant
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9
concentrations and combustible gas concentrations which may
indicate increased health risks related to the Landfill, and
may indicate'that additional remedial activities are
necessary. In addition, an existing combustible gas well
will be modified to a gas vent in order to mitigate
combustible gas that may accumulate. This will be
accomplished by venting the gas well to the atmosphere.
Finally, the on-site Shop Well will be permanently sealed in
accordance with the Minnesota Water Well Code, Minn. Rules
Chapter 4725.2700.
Annual inspection and maintenance to assure the integrity of
the existing landfill final cover system will be conducted
in conjunction with the monitoring program. This inspection
and maintenance will consist of, but not be limited to,
mowing the cover vegetation, removing woody vegetation, such
as trees, and repairing eroded and/or subsided areas. site
access will be controlled by means of a locking gate at the
only road entering the facility, as well as the posting of
"No Trespassing" signs. Institutional controls, such as
deed restrictions to notify potential buyers of the property
of the conditions at the site might be obtained.
The Minnesota Water Well Construction Code, Minn. Rules Ch.
4725.2000, Subp. 2, regulations regarding the installation
of potable wells near landfills will apply.
In addition to all of the elements of Alternative 2,
.Alternative 3 incorporates the stabilization of the west and
northwest slopes of the Landfill. Two versions of the slope
stabilization activity are considered. Version 1 involves
reshaping and recompacting the exposed northwest corner of
the Landfill, covering exposed waste and backfilling the
access ramps on the west side of the Landfill (Attachment
6). Version 2 involves a comprehensive restoration of the
Landfill's western slope and the borrow pit area where fill
material was removed and used to cover waste during landfill
operation (Attachment 7).
Also, this Alternative will observe the requirements of the
Minnesota Environmental Response and Liability Act (MERLA),
which prohibits the disturbance of the Landfill final cover
and monitoring systems.
Cost of Alternative 3:
Capital Cost:
$155,000 (Version 1)
$295,000 (version 2)
Annual O&M Cost:
$ 22,000
30 Year Present Worth at a 10% Discount:
$361,000 (version 1)
$501,000 (version 2)
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10
VII. SUMMARY OF COMPARATIVE ANALYSIS
The NCP requires that the cleanup alternatives retained for
detailed analysis be evaluated on the basis of nine specific
evaluation criteria. This section discusses how the
alternatives compare to one another against the nine
criteria.
u.s. EPA's Nine Evaluation criteria for addressing hazardous
waste sites are:
1)
Overall Protection of Human Health and the Environment
This criterion describes how the alternative, as a whole,
achieves and maintains protection of human health and the
environment.
2) Compliance with Applicable or Relevant and Appropriate
Reauirements(ARARs)
This criterion describes how the alternative complies with
existing federal, state, and municipal laws, regulations and
other established standards.
3)
Lona-term Effectiveness and Permanence
This criterion evaluates the long-term effectiveness ~f an
alternative in maintaining protection of human health and
the environment and the reliability of controls over time.
4) Reduction of Toxicitv. Mobilitv. and Volume Throuqh
Treatment
This criterion evaluates the anticipated performance of the
specific treatment technologies employed by an alternative
in terms of their ability to reduce the toxicity, mobility
anu volume of contaminated materials.
5)
Short-term Effectiveness
This criterion examines the effectiveness of the alternative
in protecting the community and on-site workers during the
construction and implementation of a cleanup alternative.
6)
Implementabilitv
This criterion evaluates the technical and administrative
feasibility of alternatives and the availability of required
goods and services.
-------
11
7) Cost
This criterion evaluates capital and operation and
maintenance (O&M) costs. It also evaluates the present
worth cost of each alternative using standard assumptions
for the life of a project (usually 30 years) and the
discount rate (usually 5% or 10%).
8)
state Acceptance
This criterion reflects the state's apparent preferences
among or concerns about alternatives.
9)
Communitv Acceptance
This criterion reflects the community's apparent preferences
among or concerns about alternatives.
VIII. COMPARATIVE ANALYSIS OF ALTERNATIVES
A comparative analysis of the three alternatives against
each of the nine criteria is presented below and summarized
in Attachment 8.
1)
Overall Protection of Human Health and the Environment
Alternative 1, No Action, is currently protective of human
health since no VOC concentrations currently exceed health-
based standards, nearby residential wells did not show
detectable levels of VOCs, and the two metals of concern to
human health, arsenic and manganese, appear to be present as
naturally occurring background elements. Similarly,
Alternative 1 is currently protective of the environment
because the metals of concern for surface water and
sediments, copper, lead and zinc, when compared to the
s~rrounding area, also appear to be present as naturally
occurring background elements, with no current negative
impacts on the plants and animals at the Site. with
Alternative 1, potential combustible gas migration and
contaminant concentrations in groundwater would not be
measured and future overall protection of human health and
the environment would not be assured.
Long-term monitoring, which is part of Alternatives 2 and 3,
provides a direct indication that contaminant levels remain
within health-based groundwater quality standards. .
Alternatives 2 and 3 will provide combustible gas data in
order to monitor combustible gas migration. Such migration
may indicate changes in health risks related to the
Landfill. Alternatives 2 and 3 provide a greater degree of
overall protection than Alternative 1 as a result of the
groundwater and combustible gas monitoring, the permanent
-------
12
sealing of the old Shop Well and the access controls that
these alternatives include.
Finally, Alternative 3 is more protective than Alternatives
1 and 2 because it offers protection from the potential
exposure to uncovered fill material and protects against the
future release of contaminants from the Landfill by
minimizing infiltration. Both Version 1 and version 2 of
Alternative 3 are protective.
2)
Compliance with ARARs
CERCLA requires that remedial actions must at least attain
applicable or relevant and appropriate requirements (ARARs)
of Federal, and more stringent state, environmental laws.
The major ARARsat the LaGrande Site are discussed below.
a.
Groundwater contaminant Concentrations
The Federal Safe Drinking Water Act establishes Maximum
contaminant Levels (MCLs) for contaminants in drinking
water. The MCLs are applicable to public water systems
having at least 15 service connections or serving at least
25 residents. These standards would not be applicable to
the groundwater under and downgradient of the site since it
is not used as a public water supply. However, U.S. EPA has
determined that primary MCLs (set for contaminants.
determined to have an adverse effect on human health above
certain levels) are relevant and appropriate as cleanup
levels for ground or surface waters that are current or '
potential sources of drinking water. At present, no one is
living on or using groundwater at the Site. However, there
are residential wells downgradient from the Site using the
aquifer for drinking water. The Safe Drinking Water Act
also establishes Secondary MCLs for specific contaminants or
water characteristics that may affect the aesthetic
qualities of drinking water (i.e., color, odor and taste).
Secondary MCLs are non-enforceable guides for public water
systems and, as such, are not applicable or relevant and
appropriate requirements. Secondary MCLs may, however, be
considered in determining appropriate cleanup levels for
groundwater if groundwater remediation were required at the
site.
Minnesota Department of Health Recommended Allowable Limits
(RALs) are non-enforceable standards established for private
water supplies. Although these recommended contaminant
levels are not promulgated state standards, and therefore,
are not ARARs, these advisory levels may be considered in
determining the appropriate cleanup levels for groundwater
contaminants if groundwater remediation were required at the
Site.
-------
13
Minnesota Intervention Limits (MILs) are pollutant
concentrations (one quarter the concentration of the RAL for.
a particular contaminant) which must not be exceeded at the
Compliance Boundary of a mixed municipal solid waste
landfill. Minnesota Solid Waste Rules, Chapter 7035,
require that MILs and RALs cannot be exceeded at this
boundary. The Compliance Boundary is required to be
established at a maximum distance of 200 feet from the
permitted waste boundary. These rules are not applicable to
the LaGrande landfill because the landfill was closed prior
to their effective date; however, they are relevant and
appropriate because the rules are intended to ensure that
solid waste landfills, like LaGrande, do not become a source
of groundwater contamination.
Currently, the groundwater under and downgradient of the
site attains the primary MCLs for all organic and non-
organic compounds tested. Manganese and arsenic exceed
RALs. Three semi-volatile compounds, phthalate esters,
exceed proposed primary MCLs for phthalates. Since they are
not final, promulgated standards, these proposed MCLs are
not ARARs, but are to be considered; they would be
applicable to groundwater upon final promulgation. The
presence of these compounds at the current levels does not,
however, present an unacceptable carcinogenic risk to adults
and children who could be exposed to the groundwater through
its use for drinking or showering. Manganese is present in
amounts sufficient to present a potential risk of non-
carcinogenic health effects (Attachment 5). This concern is
derived primarily from elevated manganese levels (over
background levels) measured in the old Shop Well. Based on
RI sampling, the landfill itself does not add to the
naturally-occurring elevated manganese levels.
Alternative 1 would not comply with the requirements of
Minn. Rules, Chapter 7035, that MILs and RALs must not be
exceeded at the Compliance Boundary, since it does not
incorporate long-term monitoring, necessary to verify these
requirements. Alternatives 2 and 3, which include long-term
groundwater monitoring, would comply with these
requirements.
Manganese is the only contaminant currently present at
levels that may warrant taking response action to protect
public health. Because the Shop Well is the major source of
the high manganese levels and represents the bulk of the
non~carcinogenic risk at the site, it will be permanently
sealed and abandoned in accordance with the requirements of
the Minnesota Water Well Construction Code, Minn. Rules,
Chapter 4725.2700, to assure that it will not be used as a
potable water source.
-------
14
b.
Soils/Landfill Cover
The landfill was closed in 1984. The existing final cover
system exceeds the State of Minnesota cover standards that
were required at the time the landfill stopped accepting
waste in April, 1984, except for the exposed area of waste
at the northwest corner of the Landfill. Alternatives 2 and
3 include maintenance of this existing cover system.
Alternative 3 also includes the stabilization and repair of
the existing cover on the northwest corner of the Landfill.
The existing cover does not meet the state's present
standards for a four foot final cover system under Minn.
Rules Ch. 7035 for solid waste landfills. These cover
standards are not applicable to the LaGrande Landfill,
because they were promulgated after the Landfill terminated
operations and received its final cover. The Chapter 7035
cover requirements would be relevant to closure of the
LaGrande Landfill, however, because they are intended to
regulate closure of solid waste landfills similar in nature
to the Site.
It is the opinion of the MPCA and the u.S. EPA that, with
the exception of the area of exposed waste at the northwest
corner of the Landfill, the existing final cover system is
performing adequately in minimizing the infiltration of
water through the landfilled waste and in protecting against
direct physical contact with the landfilled waste. This
conclusion is based upon the findings of the RI and the
public health and environmental risk assessments. Altering
the existing cover system to comply with the new standards,
or meeting the new standards for the small area to be
stabilized and recovered, would not significantly add to the
overall effectiveness of the existing cover system.
Furthermore, it would not enhance protection of surface
water and sediments since there is no hydraulic connection
between them and the groundwater. Finally, the short-term
risks and the additional costs associated with the major
construction activity that would be required to upgrade the
existing cover system are not justified, based on the low
level threat posed by the site. Therefore, the Agencies
have determined that those sections of the current Chapter
7035 cover standards, requiring placement of additional
earthen or synthetic materials on the entire existing cover
system, are not appropriate for the LaGrande Landfill site.
All three alternatives would adhere to the requirements of
MERLA, which prohibits the disturbance of the landfill final
cover system.
-------
15
c.
Landfill Gas Monitorinq and ventinq
Minn. Rules Chapter 7035 requires that decomposition gases
from solid waste landfills must be vented into the
atmosphere in order to prevent explosive concentrations from
accumulating. It also requires landfill gas control
monitoring. These requirements are both relevant and
appropriate to the LaGrande Landfill, because the production
of landfill gas within the waste mass was confirmed during
the RI. .
Alternative 1 does not comply with these requirements.
Alternatives 2 and 3 incorporate landfill gas monitoring,
and would, therefore, cQmply with the Minn. Rules Chapter
7035 requirements.
J)
Lonq-Term Effectiveness
The No Action alternative is not effective over the long
term. It does not include provisions for monitoring data to
identify changes in groundwater contaminant concentration or
potential combustible gas migration over a long period of
time.
Alternatives 2 and 3 allow for additional future
warranted by the additional monitoring data that
collected. Furthermore, both Alternatives 2 and
the permanent sealing of the on-site Shop Well.
Alternatives 2 and 3 are, therefore, more effective over the
long-term than Alternative 1. Alternative J, Version 2
provides the maximum long-term effectiveness because it
includes stabilization of the western slope of the Landfill,
the covering of exposed waste, and the comprehensive
reconstruction of the borrow pit area. This is likely to
reduce the amount of precipitation entering the Landfill
waste and reduce the potential for failure of the existing
final cover system and erosion of the borrow pit area.
actions if
will be
3 include
4)
Reduction of Toxicity. Mobility. and Volume (TMV)
Because Alternatives 1, 2 and 3 involve no groundwater or
combustible gas treatment, the toxicity, mobility and volume
of the low levels of contaminants measured at the Landfill
will not be reduced. However, toxicity, mobility and volume
of landfill contaminants in the future will be minimized by
the slope stabilization and the covering of exposed waste
proposed in Alternative 3. These actions will help to
prevent the leaching of contaminants from the Landfill into
the environment.
-------
16
5)
Short-Term Effectiveness
The monitoring elements of Alternatives 2 and 3 pose minimal
risk to the local community and site workers. The slope
stabilization activities of Alternative 3 are not expected
to release hazardous compounds because no in-place waste
will be excavated. The minimal impacts of fugitive dust
emissions and drainage during construction will require some
mitigation measures.
6)
Implementabilitv
Alternative 1, requiring no construction, is the easiest to
implement. Alternative 2 requires minimal construction and
is easily implemented using common construction methods.
The slope stabilization component of Alternative 3 can be
easily implemented in a short time. Services are readily
available in the area and on-site materials would likely be
used for slope stabilization and covering the exposed
northwest corner of the Landfill and reconstruction of the
borrow pit area. The other required elements of
Alternatives 2 and 3, including the permanent sealing of the
on-site Shop Well, site access controls, monitoring and
analytical services, are also immediately implementable.
The technologies for these actions are proven and readily
available.
7)
Cost
Alternative 1, No Action, is the least costly alternative,
followed by Alternative 2, Long-Term Monitoring with a Gas
Vent Well. Alternative 3, Version 2, Long-Term Monitoring
with a Gas Vent Well and Slope Stabilization is the most
costly alternative (Attachment 9). The specific 30 year,
present worth costs of the various alternatives are as
follows:
Alternative 1:
Alternative 2:
Alternative 3:
Alternative 3:
(Version 1)
(Version 2)
$0
$279,000
$361,000
$501,000
8)
State Acceptance
The selected remedy, Alternative 3, Version 2, is acceptable
to the State. Alternative 1, No Action, is not acceptable
while Alternative 2, Long-Term Monitoring, is considered the
minimally acceptable alternative.
9)
Communitv Acceptance
The selected remedy is acceptable to the public.
A public
-------
IX.
"
17
meeting was held on september 2, 1992, where the MPCA and
the U.s. EPA presen~ed the alternatives to a group of
interested citizens. The Responsiveness Summary (Attachment
10) addresses specific comments raised at the September 2nd
public meeting and during the public comment period. The
public comment period officially ended September 15, 1992.
No formal request for an extension of the comment period was
received by the MPCA or the U.S. EPA.
THE SELECTED REMEDY
U.S. EPA and MPCA's selected remedy for remedial response at
the LaGrande Sanitary Landfill is Alternative 3, Version 2. .
This alternative includes:
1.
long-term monitoring of groundwater and combustible gas
to verify that the low level of threat posed by the
con~aminants of concern remains low and that the
landfill does not generate potentially explosive levels
of combustible gas;
2.
the conversion of a combustible gas monitoring well to
a gas vent to assure that combustible gas does not
accumulate at the single point where the soil gas level
was measured at greater than 100% of the lower
explosive limit (LEL);
3.
the permanent sealing and abandonment of the on-site
Shop Well in conformance with the Minnesota Water Well
Code, Minn. Rules, Chapter 4725.2700, to assure that
this well will not be used as a potable water source;
4.
the stabilization of the west slope of the Landfill and
the covering of exposed waste on the northwest corner
to assure that the existing landfill cover, which is
providing an effective barrier to infiltration, remains
effective;
5.
the sloping and reconstruction of the borrow pit area
adjacent to the west slope of the Landfill to assure
the long-term integrity of the cover system;
6.
institutional controls in the form of site access
restrictions, and the possible use of deed
restrictions;
7.
maintenance of the existing final cover system so as to
reduce the future potential for infiltration into the
waste mass and the subsequent leaching of landfill
contaminants; .
-------
18
8.
observance of Minnesota Environmental Response and
Liability Act prohibitions against the disturbance of
the Landfill final cover and monitoring systems; and
9.
observance of the Minnesota Water Well Construction
Code, Minn. Rules Chapter 4725.2000, which regulates
the location of future potable wells near the Landfill.
x.
STATUTORY DETERMINATIONS
The implementation of the selected remedy, Alternative 3,
Version 2, at the Site satisfies the following requirements
of CERCLA Section 121:
Overall Protection of Human Health and the Environment:
The long-term monitoring of groundwater at the Site will
provide confirmation that the present low level (less than
104) risks posed by the contaminants of concern remain low,
and will provide a basis for action should these risks
exceed U.S. EPA acceptable risk levels. The sealing of the
old Shop Well will eliminate the potential noncarcinogenic
risk posed by that well by eliminating it as a source of
potable water.
The conversion of a combustible gas monitoring well to a gas
vent will reduce the potential for combustible gas buildup
since any combustible gas that accumulates will be .
dissipated through the vent.
The stabilization of the west slope of the landfill,
covering of exposed waste at the northwest corner of the
landfill, and the sloping and reconstruction of the borrow
pit area will reduce the potential for infiltration into the
landfill and future leaching of contaminants from the
landfill.
Finally, institutional controls in. the form of site access
restrictions, the possible use of deed restrictions, the
observance of the Minnesota Environmental Response and
Liability Act (MERLA) prohibitions against the disturbance
of the Landfill final cover and monitoring systems, and the
observance of the Minnesota Water Well Construction code
regulating the location of future potable wells near the
Landfill, will further ensure that the active controls
described will remain effective.
Compliance with ARARs:
The selected remedy will comply with the relevant provisions
-------
19
of the following Federal and state ARARs, which have been
identified for the site:
Federal ARARs
Safe Drinking Water Act, 40 CFR Parts 141-149 - Establishes
final and proposed Maximum contaminant Levels (MCLs) for
contaminants in drinking water.
Final MCLs- Relevant and Appropriate.
Proposed MCLs- To be considered.
State ARARs
Minnesota Department of Health R~commended Allowable Limits
(RALs) - Non-promulgated, non-enforceable, advisory
standards established for private water supplies. To be
considered.
Minnesota Rules Chapter 7035- Regulate mixed municipal solid
waste landfills and establishes the following requirements:
Minnesota Intervention Limits (MILs). MILs are
pollutant concentrations ( one quarter the
concentration of the RAL for a particular contaminant)
which must not be exceeded at the Compliance Boundary
ofa~xed municipal solid waste landfill. Relevant
and Appropriate.
,.;
. ':
,\1,
Decomposition gases from solid waste landfills must be
\.. .
vented:1nto the atmosphere 1n order to prevent
explosive concentrations from accumulating. Relevant
and Appropriate. .
Minnesota Statutes, Chapter 115B (Minnesota Environmental
Response an"'Cr'~'Liability Act), Minnesota State Superfund-
Provision prehibiting the disturbance of the final cover
system on a landfill. Applicable.
Minnesota Rules, Chapter 4725.2700, Minnesota Water Well
Construction Code- Regulates well construction, sealing and
abandonment. Relevant and Appropriate.
Cost-Effectiveness
The selected remedy provides an. effective remedy
proportionate to its cost. The degree of long-term
effectiveness and permanence, reduction of toxicity,
mobility arid volume of contaminants, and ease of
implementability afforded by this remedy for the cost
it a reasonable value.
make
-------
20
utilization of Permanent Solutions and Alternative Treatment
Technoloaies or Resource Recoverv Technoloaies to the
Maximum Extent Practicable
Because of the low level risks posed by the site, treatment
of on-site media is not considered necessary. The long-term
monitoring of groundwater and combustible gas requirements
of Alternative 3, Version 2, will provide continued
verification that the low level risks remain low. In
addition, the sealing of the old Shop Well will permanently
eliminate it as a source of noncarcinogenic risk from
excessively high manganese levels. Finally, the slope
stabilization, covering of exposed waste, and reconstruction
of the borrow pit area, will ensure the maintenance of
Landfill cap integrity.
The criteria most critical in the selection of the remedy
were long-term effectiveness, implementability and cost.
Alternative 3, Version 2, ensures that the low level risks
at the Site will continue to be monitored to verify the
effectiveness of the minimal construction components of the
remedy over the long-term. Because it requires minimal
construction and restoration activities, it is easily
implementable. Finally, the cost of the remedy, when
compared against the other primary balancing criteria, makes
it a reasonable value. The State of Minnesota and the
community support Alternative 3, Version 2.
The selected remedy meets the statutory requirement to
utilize permanent solutions and treatment technologies to
the maximum extent practicable.
Preference for Treatment as a Principal Element
The preferred alternative will not satisfy the statutory
preference for treatment as a principal element since
treatment is not considered necessary due to the low level
of risk posed by the Site.
-------
. At'tacnmen1: 1
"
I -'2DANDE
SAMl'AAY
LANDFILL -
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.
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NOT. TO SCALE
~
GENERAL SITE LOCATION MAP -
laGRANDE SANITARY ~DF1LL AI
FIGURE 1-1
-------
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Ref: Alexandria West and BrandOn. Mime.. USGS
7.5 Minute (Topographic) QuadrBnOtes.1988
,
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SCALE IN FEET
c:aaaM--- ...
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~
SITE LOCATION MAP
LaGRANDE SANITARY lANDFIlL RI
FIGURE 1-2
POOR QUAl\\'!
OR\G\NA\.
-------
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SKETCH OF laGRANDE SANITARY LANDFILL SITE
LaGRAND TOWNSHIP. DOUGLAS COUNTY
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POOR QUALITY
ORIGINAL
-------
£..,- -'W"""64.....uc;n 1:. ~
TABLE 6-14
SUMMARY OF CANCER.1US1C. ESTIMATES
LAaRANDE SANrrAJlY LANDFILL
CDI I
Adjulrat . Chcllllic:ai- Total
CDI for SF spa:IIM: pam-, I
Chcaucat (ID~Y' Ab--- (lDgtq-GaY; Risk Ria I
i
I
I
; EXPOSURE PA11IWAYS FOR RESIDENT ADULTS
I IN.GESTION
I bil(2~""".I.'A 7.21E~ ~o 1.42E~ 1. 03E-06
I b~pDd1a1818 B.32E~S
!
ar-.: .USE~S ~o 1.75£-+00 3 .49E~S 3.S9E-05 I
DERMAL CONTACT :: :.s(2-cda~,*W"'''_I_- 6.69E-06 Yea 1.42E~ ~SOE~ I
'1J~~1p' r..'''. :' . 66E-06
U'IaIC 7 .06E~ Yes I.&4E-+OO :.30E~ ::.:SE~I
!
iTOTAL EXPOSURE RISK FOR RESIDENT ADULTS 8.61E-05 I
EXPOSURE PATHWAYS FOR RESIDENT CHlLDaEH
INGESTION b~~"'I.t- 3.4OE~ ~o 1.42E~ ~ 83E~7
b~"-I- 3.l1E~
"-':.'; 2.26E~S ~o 1. 75£-+00 3.9SE~S
"
DERMAL CONTACT \ 1.42E~ 3.20E~8
:'i.82~1V""'-1- 2.2SE-06 Ya
b~tr"'.I- 2.s7E-06
a~ 2.37E~ Yes 1.&4E-+OO ~ 36E~
~ .oas-os
; TOTAL EXPOSURE IUS FOR RESJDENT CHlLDaEH
I
~;'
:'. S6E-OI I
i
I
4.01E-GS I
I
SJGp8 -- ior -- ~ IIijIIIIII& for ""f1118 u ioUowI:
SF/ABS = Adj SF
w.... ASS. I .00 for orpaiC .... I. (dcf8III&)
0.95 lor anaIII: (ATSDR. 19m
SUMCAHRIC.wld
0871~M16
-------
Attachmen~ 5
"
TABLE 6-13
SUMMARY OF CHRONIC NONCARCINOGENIC HAZARD INDEX ESTIMATES
I
i
!
i
LACiRANDE SANrr ArtY LANDFILL
i
I
I
I
!
i
I
I EXPOSURE PATHWAYS FOR 8ESIDENT ADUL'IO
i INGESTION bi8(I~)Phdlala&o
b~ip".".I.tA
di-e-oayt"""...ItA
ChcmiI:U
U88iI:
"'..8'~
DERMAL CONTACT
bi.li:l~i)phtlWa&o
butyibeaz.vip..th.a.t.
di~"i1d1aW8
snaac:
~...~.
CDI
(mBlkl-day)
CDI
Ad"'"
for RID
~ (~y)
H-u
Quatialt
~ .70E~ So 2.00E-02 g.SOE~3
1.94&-04 So 2.ooE~1 9.7OE~
1.49&-04 So 2.ooE-02 "7 .4SE~3
1.13E~ So 3.ooE-04 3.77E~1
1.36E~1 So 1.00E~1 i .36E+OO
1.56£-05 Yea 2.00E-02 "7.80E-04
1.79E~S Yea 2.00E-01 3.95E-05
1.37E~ Yea 2.00E-02 6.&SE~3
1.6SE-G7 Yea 2.&SE-04 5. 79E~
1.99E~ Yea 5.00E-03 3.98E-02
iTOT AL EXPOSURE HAZARD INDEX FOR RESIDENT ADULTS
I
EXPOSURE PATHWAYS FOR RESIDENT CHILDREN
INGESTION
bi8(:l~)pI'"Io.I-
bu&)ibcGzyll'".".I-
di .&. .41;ph,lo8l-
U88II:
....1..&8
3.96£-04
4.S3E~
3.41&-04
2.66E~
3.11E~1
bisa-cdayibczyl)pl'"lo.I- :.62E~
b~lp"'''.I... 3.00E~5
di A ~*pDd18i8&8 2.31E~
4~ 2.76£-07
......... 3.33E~
I TOTAL EXPOSUm: HAZARD INDEX FOR RESIDENT CllU)JtEH
DERMAL CONTACT
So 2.00E-02 l. 91E-01
No 2.00E~1 :!.m~3
No 2.00E-02 1.74E-02
No 3.00E-04 8.1OE~1
No I.OOE~I 3.11£+00
Yes 2.00E-02 1.31E~3
Yes 2.00E-01 I.SOE-04
Yea 2.00E-02 I . 15E-02
Yes 2.&SE~ 9 .6IE~
Yes 5.ooE~3 5.66E~2
RID . ASS . Adj am
R1Da for denali ~. _.ajaad for ...~.. ioIknn:
..,.. ASS ... 1.00 for orpaic .."---I. (deCal&)
= 0.9S for 8rICIIiI: (ATSDR. 1989)
= 0.05 for "'-8"- (ATSDR. 1991)
0811-()9-9M16
p~
H-u
lAd8a
1.75£+00 I
~.IIE-02 1
I
1.8OEtOO I
4.10£+00
3.06£-02 I
'.-1
sUMllE$T2.wld
-------
n."''''Q~nmen1:
6
WOODS
---
BORROW
-N-
WOODS
~
SLOPE STABILIZATION
VERSION 11
LaGRANDE SANITARY LANDFILL FS
MA
FIGURE 3-4-
-------
Attachment:
7
WOODS
M
-..-
COVER EXPOSED
WASTE
WOODS
BORROW
AREA
BACKFILL
RAMPS
WOODS
BUILDING
Q', \.
" \
-
....... ----.1
-----.....
. ACCESS ROAD
-N-
WOODS
~.
MARSH .
~
SLOPE STABILIZA110N
VERSION 12
LaGRANDE SANITARY LANDfill FS
FIGURE 3-5
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TABLE 4-J
IAGRANDE SANITARY IANIWILI,S FS
COI\WAI(ATIVE ANALYSIS AMONG AI.TEItNATIVES
EYilultlon CrIteria I-No Adlon 2-1.ong Tenn Monllorlng(LTM) 3-LTM Ind Slope Stabilization
. - ....:..
Overall Protection of Human Lowest Protection Intermediate Protection Maximum Protection
Health'" Environment
Compliance with ARARs Does not comply with Complies with MN Rules for soil Complies with MN Rules for
MN HultS-Mixed Munici. gas and ground water monitoring soil gas and ground water mOI\-
pal Solid Waste fur soU horing
gas and ground watt:r
monitol ing
Long-Term Bffectiveness May be effective. No Bffective for soil gas and ground. Effective for soil gas and
tons term soil gas/ground water monitoring. No reJuction ground water monitoring "nil
water mOllitOling dala. in pmential for landfill cap fail- reducljun in th~ potenlial for
No reduction in I)ot~nlial me. landfill cal) bUul"e.
for landfill cal) failure.
Reduction of Toxicity, Mo- Not applicable, no treat- Not applicable, no treatment Not applicab,le, no treatment
bility, Volume ment proposed. proposed. propOsed.
Short-Term Effectiveness Not applicable. Minimal risk to public and sam- Minimal risk to public and
piing workers. ~ite access con;. sampling workers. Site aoccss
trois implemented. controls implemented. Slope
stabilization may rt:~nrnent 8
Page I or 2
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,0
"
TARtE 4-]
LAG RAN DE SANITARY IANIWII.I.S ..-S
COl\lltAItATIVE ANALYSIS AMONG AI.TEItNATIVES
IntuItion Criteria I-No Adlon 2-Lonl Term Monllorlnl (LTM) ]-I.TM and Slope Stabilization
_.1..' .. ,--- ~. "..., -------8R",",*"-- "11&1.'-""'. .-------".. - ..-.~ aaaa...a:a.a::.a:a.. -.-.. ......-- a..&:;:.&I.
Implementability Nol Administratively Technically and administratively Technically and Administra-
feasible. feasible. lively feasihlc.
. .
Cost-First Year No Costs $13,000 $ 15S,OOO-$295,OOO
Cost-Second Year No Costs S22,OOO $22,1100
30. Year PrC5ent Worth Cost
S% Discount Rate No Cusls $406,OUO $4HH,mIO-$62H,()()O
10% Discount Rate No Costs S279.000 $161,000-$501,000
. . w . .. .w..
State Acceptance Not Acceptable Not Acceptable Jtcceptable
Community Acceptance Not Acceptable Not Acceptable Accept'able
- - - - -
0871.()9-9MI2
Page 2 (If 2
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Co.~ '- ............ ..u.-.. , .... ;;
TABLE 4-1
LAGRANDE SANITARY L\NDFILL FS
Q
Ec:Tf'I'AA TED COST FOR ALTERNA 11YE 3.
COST
IMK
INS1TI'UI'IONAL CONTROLS;
S 13.000
(IndudC$ site development. deed
resaicUDDS and well abandonment) .
GROUND WATER AND SOn. GAS MONITORING:
(Inciucies eight on-site weils ami
four resicic:ntiai weiis)
FUst Year:
ADDuai!y. thereafter:
S60.000
S22.000
SLOPE STAJ:tTT T7 J\TION:
Version #1:
Version #2:
$80.000
$220.000
TOTAL COST RANGE FOR FIRST YEAR:
TOTAL COST ANNUALLY. 'l'HEREAFfE1C
S1SS.000-S29S.000
S22.000
3Q.Year Present Wonh Cost Range:
S9& Discount Rate:
109& Discount Rate:
S4l8.000.S628.0oo
n6t.oOo.SS01.000
NO'IE:
Addmnaai ~ppl castS may result from future repja.-meDt
or refurbjsbmeDt of mcmi10riDg weils.
O871~MU
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