United states
Environmental Protection
Agency
OffIce 01
Emeroency and
Remedial Response
EPAIROO/R05-881063
December 1987
"EPA
Superfund
Record of Decision:
\/Vasta Disposal, MN
. U S Environmental Protection AgencJ
R~gion III Information Resourc~ .
Center (3PM52) /
M\ Cnes\~ut Street .-:.::;"~~
~hUndelpt\la, ~A 19101 - ~.::~
Hazardous Waste Collection
Information Resource Center
US EPA Region 3
Philadelphia, PA 19107
IEPA Re~ort Collection
Information Resource Center
US EPA Rt5gion 3 .
Philadelphia. PA 19107
, .
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50272 . 101
REPORT DOCUMENTATION 11. REPORT NO.
PAGE EPA/ROD/R05-88/063
12.
I
3. Recipient's Acceulon No.
~. Title and Subtitle
SUPERFUND RECORD OF DECISION
Wa~te Disposal, MN
'irst Remedial Action - Final
5. Report Oa"e
12/ Jl/88
6.
. Author(s)
8. Perlormin8 Ol'8anizatlon Rept. No.
9. Perlormln. O..anlntlon Name and Addre..
10. Project/Task/Work Unit No.
- _. --..--
"-
11. Contract(C) or Grant(G) No.
(C)
(G)
.-- -
"
12. Sponsorin8 Or.anlzatton Name and Addr..s
U.S. Environmental Protection
401 M street, s.w.
Washington, D.C. 20460
--
13. Type of Report & Period Covered
.Agency
800/000
1~.
15. Supplementary Notes
16. Abstract (Limit: 200 words)
The Waste Disposal Engineering (WDE) site, consisting of 73 acres of a 114-acre du~p,
is located in the City of Andover (formerly Grown Township), Anoka County, Minnesota.
The site area is characterized by low relief with shallow water tables and numerous
wetlands. During the past year, most extensive residential develoPl!1ent has been or will
be constructed and planned for around the site. The original dump was established in
1963 and operated until 1908. Disposal of wastes was by burial or burning in pits or
~renches. In 1968, WDE purchased the dump and was licensed by Grow Township to operate
3 a sanitary landfill. In 1970, WDE submitted a solid waste permit application which
included a proposal to build a specially constructed pit for hazardous waste disposal.
A permit was issued in March 1971, to operate the site as a sanitary landfill. The pit
received approximately 6,600 containers (ranging from one gallon pail to fifty-five
gallon drums) from 1972 to 1974, in the form of acids, caustics, waste paints, spent
solvents, plating sludges, and cyanides. An undetermined quantity of hazardous waste,
much of it as bulk loads, was disposed throughout the landfill. Of the 3,200,000
gallons of hazardous waste thought to be disposed at the site, only ten percent is
thought to have been disposed of in the pit. The area of refuse/non-hazardous waste
disposal covers an area of 73 acres and contains approximately 2,500,000 yd3 of
(See Attached Sheet)
17. Document Analysis a. Descriptors
Record of Decision
Waste Disposal, MN
First Remedial Action - Final
Contaminated Media: gw
KeVdCtantaminantsf. organics, VOCs
-1)."'1 en Iffl6rslOilen.Eridecf erms
c. COSATI Field/Group
11. Availability Statement
119. Security CI~SS (This Report)
None'
t20:s~~-urity Clas~ (This Page)
I None
21. No. of Pa8es
81
- - --- ----
22. Price
(See ANSI-Z39.1B)
See Instructions on Reverse
OPTIONAL FORM 272 (4-77)
(Formerly NTlS-35)
Department 0' Commerce.
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EPA!ROD/R05-88/063
iste Disposal, MN
_lrst Remedial Action - Final
16.
ABSTRACT (continued)
waste. Much of the landfill is covered by lime sludge. The landfill and pit have
remained abandoned and inactive since February 1984. The site property has gone through
tax forfeiture so that it is currently property of the State of Minnesota with
administration by the county. Currently, the pit area shows the most serious ground
. water degradation and is the dominant source of contaminants entering Coon Creek. The'
primary contaminants of concern include VOCs and organics.
The selected remedial action for this site includes: ground water pump and treatment
using carbon adsorption with off site discharge to Coon Creek: installation of a RCRA cap
to completely cover the 73-acre landfill: installation of a clay slurry wall:
implementation of institutional controls including well use restrictions: filling in of
a wetland, construction of an alternate wetland area, and extensive monitoring: the
estimated capital cost for this remedial action is $9,504,796 with present worth O&M of
~862,9l5.
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RECORD OF DECISION
REMEDIAL ALTERNATIVE SELECTION
Site:
Waste Disposal Engineering. Andover. Minnesota
Documents Reviewed
The following documents. which describe the physical characteristics of the
Waste Disposal Engineering Site and which analyze the cost-effectiveness of
various remedial altematives. have been reviewed by the United States En-
vi romental Protection Agency (U.S. EPA) and form the basis for this Record
of Decision (ROD):
Modified Appendix 6. Remedial Investigation. Conestoga - Rovers &
Associates Limited (CRA), January 30, 198~.
QA/QC Data Asses'sment, CRA, February 1, 1986.
QA/QC Data Assessment, Volume 11 Appendices, CRA, February 1. 1986.
Addendum to Modified Appendix 8. CRA. February 28, 1986.
Renedial Investigation, CRA,March 31, 1986.
Supplementary Monitoring Report. CRA. July 25, 1986.
Pit Investigation, Summary Report. CRA. August 7, 1986.
Supplemental Remedial Investigation Report. CRA, September 22. 1986.
Altematives Report. CRA, April 18, 1986.
Deta 11 ed An.l,5is Repo rt. CRA, Octobe r 9, 1986.
Detailed Analysis Report Appendices. CRA, October 9, 1986.
Response of SW28 Group to U.S. EPA Letter Dated May 28. 1987, CRA,
July 9. 1987.
Public comments received during the 21-day comment p'eriod, and the
Responsiveness Summary.
Summary of Remedial Altematives Selection.
I have al so considered other docll11ents which are incl uded in the attached
index to the administrative record.
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Description of Remedy
The selected remedial alternative for the Waste Disposal Engineering Site is
to cover the landfill with a vented cap, to contain contaminated ground water
discharges from the landfill through downgradient ground water extraction
wells, to contain an area within the landfill which received hazardous waste
(hereinafter referred to as the 'IPit") with a slurry wall and extraction
well system, to avoid usage of contaminated groundwater and reversal of the
. upward gradient between the lower and uppers sand aquifers through institutional
controls to limit wells on and near the site, to fill-in and replace a wetland
area affected by the site, to treat and dispose of extracted ground water, '
which is expected to be accomplished by carbon adsorption and discharge to
Coon Creek, and to monitor the site. The selected alternative includes the
following major ccmponents.
Lime sludge cap meeting Resource Conservation and Recovery Act (RCRA)
technical perfonnance standards.
"Ground water extraction wells in the upper sand aquifer between
Coon C reek and the 1 and fi 11 .
Clay slurry wall around the Pit with pumping inside the wall.
Institutional cOntrol.s to prohibit uppers sand aquifer wells at the
site and just north of Coon Creek and .to prohibit lower sand aquifer
wells near the landfill.
Carbon adsorption treatment of extracted ground water (air stripping
or a combination is possible based on design.
Di scha rge of treated ext racted ground wate r to Coon Creek.
Monitoring, including geophysical work around the site to locate
heavier-than-water non-aqueous phase liquid monitoring, to assure
the effectiveness of the remedy.
Consistent 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 National Oil and Hazardous Substances
Pollution Contingency Plan (NCP), 40 C.F.R Part 300, I have detennined that,
at the Waste Disposal Engineering Site, the selected remedial alternative
is cost-effective, provides adequate protection of publ ic health, wel fare,
and the environment, and utilizes treatment to the maximum extent practicable.
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I have determined that the action being taken is consistent with Section
121 of SARA. The State of Minnesota has been consulted and is expected to
conc u r wi th the se.l ected remedy.
In acconjance with Section 121 (c) of SARA, the remedial action at the
Waste Disposal Engineering Site shall be reviewed no less often than every five
years after initiation of such remedial action to assure that human health
and the environment are being protected by the remedial action being
impl emented.
~IU.. Cbn.~
1.~ Valdas V. Adamkus
~v ~ Regional Administrator
I~- 3/- 87-
Date
Attachments:
(1) Surrmary of Remedial Altemative Selection
(2) . Responsiveness Sunmary
(3) WOE Administrative Reconj Index
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Site Surrmary of Remedial Alternative Selection
Waste Disposal Engineering Site
Andover. Minnesota
I.
Site Location and Description:
The WOE Site is located within the City of Andover (formerly Grow
Township), Anoka County, Minnesota (see Attachments 1, 2), approx-
imately 15 miles north of the City of Minneapolis. It is situated on
the south side of Coon Creek, which discharges into the Mississippi
River 11 river miles downstream from the Site. The discharge into the
Mississippi River is approximately 3 miles upstream of the intake for
the St. Paul water supply and 7 miles upstream of the intake for the
Minneapolis water supply.
The WOE Site is situated within the Anoka Sand Plain. The topography
is gently rolling to flat, with shallow water tables (less than 20
feet) and numerous wetlands. The area surrounding the WOE Landfill
historically was comprised of small fanns and smal~ residential de-
velopments. Immediately south of the Site are a series of scrapyards.
During the past year. more extensive residential development has been
or will be constructed and planned for around the Site. The Site is
bounded on the north by Coon Creek, with flows in a west-northwesterly
direction at this location. To the west, the Site is bounded by Anoka
County Road 18 (Crosstown Boulevard). farm land, and a residential
development (Red Oaks Manor). The southern boundary of the Site
consists of woodlands and cOl1J11ercial developments (mostly scrapyards)
along Anoka County Road 16 (Bunker Lake Boulevard). Hanson Boulevard
borders the eastern edge ,of the WOE Site. Along the eastem edge of
the Site are two overlapping easements, United Power Association (45
feet wide) and Northem States Power Coopany (150 feet wide).
The original dump was established in 1963 by a Mr. Leonard Johnson.
Disposal of wastes was by burial or buming in pits or trenches. WOE
purchased the facil ity in 1968 and was 1 icensed by Grow Township to
operate as a sanitary landfill. In 1970, WDE submitted a solid waste
pennit application to the MPCA, including a proposal to build a
specially constructed pit for disposal of hazardous waste. The permit
(SW-28) was issued on March 30, 1971 to operate the WOE Site as a
sanitary landfill. The Site operating permit was revoked by the
MPCA in February. 1984.
The hazardous waste pit received hazardous wastes from November, 1972
to January, 1974. The base of the pit was specified to be an 18-inch
layer of clay overlain by a six-inch bituminous layer and six inches
of crushed 1 imestone. Approximately 6,600 containers (ranging from 1
gallon pails to 55 gallon drums) holding a wide variety of wastes
(acids, caustics, waste paints, spent solvents, plating sludges.
cyanides) are thought to have been disposed in the pit. An unde-
te~ined quantity of hazardous waste, much of it as bul k loads, was
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2
disposed throughout the landfill. Based on interviews and govemment
files, apPrQximately 3.2 million gallons of hazardous wa"ste are thought
to have been disposed at the WOE Site. Using these estimates, only 10
percent of the waste expected to be at the Site would have been
disposed in the pit.
The area of attual refuse disposal in the landfill covers an area of 73
acres (see Attachment 3). The maximum thickness of waste is 40 feet.
The landfill contains nearly 2.5 million cubic yards of waste. Much of
' the landfill is covered by lime sludge obtained from the Minneapolis
Drinking Water Treatment Plant. ,The lime sludge consists of very fine
particles of lime that yields a clay-like substance. The sludge
thickness ranges from three to six feet (average of four feet).
Additional lime sludge is stockpiled on ten acres immediately southeast
of the area of refuse disposal.
The WOE facility ceased operations in February, 1984 and has remained
abandoned and inactive. The property of the Site has gone through tax
forfeiture so that it is currently property of the State of Minnesota
with administration by Anoka County.
II.
Sit e His tory:
Prior to development of the WOE Site in the early 1960's, land use con-
sisted of cropland and pastureland, and open deciduous woodland with
scattered wetland pockets. The area consisted of a glacial outwash
plain characterized by low relief, poor extemal drainage, and fine,
sandy soil. Also located at the Site were two related drainage
channels. One of these channels was eventually buried 'by the landfill
while the other was abandoned when Coon Creek was straightened. In
addition, by 1964, three field ditches had been constructed on the
northeast portion of the present landfill. These ditches, which are
partially buried, drain to the north and enpty into Coon Creek.
As indicated earlier, the landfill (dlJT1p) was established in the early
1960's by Leonard E. Johnson. By 1964, the dump covered only three
acres. In 1970, the landfill had expanded. to cover 41 acres, and by
1982 to its present-day size of 114 acres. The dlJT1p was purchased by
WOE in 1968. In 1971, construction of the WOE Pit began. The Pit was
completed in 1972 and was operated until January, 1974. The landfill
ope rated unt il 1984. .
4
III. Results of the Remedial Investigation:
A.
Invest i9 at ions
Investigations at the Waste Disposal Engineering (WOE) Site
included the following:
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3
1.
Review and evaluation of historical disposal practices and
other records rel ating to the Site..
Extensive aquifer sampling and water level measurements to
detennine g round water qual ity, flow di rections, etc.
2.
3.
Soil sampling in the northeast portion of the Site to define
soil contClTlination in the area of historic drainage ditches.
Coon Creek sampl i ng to defi ne the Site I s impacts on the creek.
4.
5.
6.
Soil borings to define the geology at the Site.
Lime sludge testing to define whether or not it could be
considered as a component of the landfill cap.
7.
Landfill gas measurements to define gas levels within the
landfill.
B.
Geology
The WOE Site is situated within the Anoka Sand Plain. The surficial
deposits were glacial meltwater deposits (forming outwash plains
associated with Grantsburg Sublobe later reworked by the Mississippi
River). These deposits are fine to medium sand, have relatively high
penneabilities, and are 40 to 73 feet thick at the landfill. The
outwash plain is. relatively flat, and lacks good drainage.. Numerous
small lakes and wetlands reflect high water table conditions. Many
streams in the area, including Coo." Creek, have been channelized to
lower inverts and improve drainage. Several drainage ditches were
present in the Northeast quarter of the Site prior to the landfilling.
There is a thin, gray silt till unit (0 to 15 feet thick) within the
Upper Sand Unit. This silt till is present in most deeper borings at
the Site at depths around 30 to 40 feet. However, its continuity is
uncertain, because its presence is not indicated in some drilling logs,
and it is not relied upon as an effective confining unit.
Below the Upper Sand is a red-brown clay-silt till It is a
relatively dense till, has low penneabilities [10-5 to 10-6 centimeters
per second (cm/sec)], and serves as an aquitard for the underlying
lower sand. The till thickness ranges from 10 to 40 feet thick and
becaning prog ressivel y thi nner from north to south ac ross the Site.
The surface of the till unit is highest immediately below the Pit area
of the landfill, and slopes downward concentrically from the peak (see
Attachment 4). The steepest slope is to the northwest and west.
Underlying the red-brown till is the Lower Sand. This outwash was
deposited by the Superior advance and retreat and consists of rela-
tively coarse sand and gravel. It becomes finer and more silty with
depth. The thickness of this unit is on the order o~ 80 feet thick.
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C.
Ground Water
. "
The Upper Sand aquifer is under water table conditions (unconfined).
Ground water flow in the Upper Sand at the Site is pronounced to the
north discharging into Coon Creek (see Attachment 5). Coon Creek
serves as the regional discharge for the Upper" Sand aquifer. At the
Site, the water table contours parallel Coon Creek. Ground water
elevations are generally in the range of 867 feet near the Creek to 880
feet south of the landfill. Ground water flow rates in the Upper Sand
are on the order of 25 to 30 feet ,per year.
The Lower Sand aquifer is under confined conditions and is artesian
under the WOE Site. In fact, in the vicinity of Coon Creek, flowing
artesian conditions exist (i.e., monitoring well 260). Ground water
flow in the Lower Sand aquifer in the region is to the southwest,
ultimately discharging into the Mississippi River, approximately 4
miles downgradient of the WOE Site. At the WOE Site, ground water flow
appears to be more towards the west-northwest because of the readings
from one particular monitoring well. Without this one well, ground
water flow patterns would be enti rely consistent with the regional
pattern. Piezometric levels in the Lower Sand aquifer are generally in
the range of 876 to 878 feet at the Site.
.
The Lower Sand aquifer is used extensively for domestic water supply,
particularly southwest (and downgradient) of the Site. The Upper Sand
aquifer is used by some residents having sand points, particularly
north .of Coon Creek. One issue of primary concern has been the
relative vertical piezometric gradients within the Upper Sand aquifer
and between the Upper Sand aquifer and Lower Sand aquifer ac ross the
red-brown till confining unit. This is particularly critical since the
gradients and flow directions are roughly opposite between the Upper
Sand aquifer and Lower Sand aquifer.
In general, there is a downward component of flow within the Upper
Sand at the WOE Site, except as one approaches Coon Creek where the
gradient switches to produce an upward flow. .
The vertical gradient across the red-brown till unit between the Lower
Sand and Upper Sand aquifers is upward under the limits of refuse dis-
posal and the area between the refuse and Coon Creek. The vertical
gradient across the red-brown till unit between the Lower Sand and
Upper Sand aquifers is downward ilTlnediately south of the 1 imits of
refuse. disposal. The gradient is consistently downward at monitoring
well nest 1 and is variable (downwards and upwards) at monitoring well
nest 23 (see Attachment 6).
The lateral ground water gradient in the Upper Sand aquifer is approx-
imately 0.005. With a hydraulic conductivity of 1.6 x 10-3 em/sec and
an asslJT1ed porosity of 0.3, the average 1 ateral ground water movenent
in the Upper Sand is approximately 27 feet.per year. The vertical
ground water gradient across the red-brown, till at well nest 1 is 0.038
using a hydraulic conductivity range of 2x 10-6 em/sec to 1 x 10-3 .
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cm/sec and an assumed porosity of 0.3, the average vertical groufld
water velocity downward across the red-brown till is approximately 0.4
to 2.0 feet/year. This is 1.5 to 7.4 percent of the lateral flowrates.
Therefore, ground water flow in the Upper Sand aquifer is primarily
lateral towards Coon Creek, but there is a downward component across
the red-brown till south of the limits of refuse disposal (see
Attachment 7).
O.
Extent and Magnitude of Contamination
Ground water contamination exists within the Upper Sand aquifer
beneath and downgradient of the landfill and ultimately enters Coon
Creek. The degradation is most severe in the upper portion of the
Upper Sand aquifer. Contaminants include typical landfill type con-
taminants (reduced pH, chlorides, and COO) and a wide variety of
organic constituents, including aromatic and halogenated volatiles,
and low levels of metals (see Attachments 8 to 12). Some of the
volatile organics found in highest concentrations include methylene
chl 0 ri de, d ichl 0 roethyl ene, t ri chl oroethane, tet rahyd rofuran, methyl
ethyl ketone, benzene, and xylenes.
The areal distribution of contaminants show the most severe contamina-
tion at and downgradient of the pit (wells W6, W8, W11, and W22A).
High concentrations or "hot spots" were detected at other scattered
locations (i .e.., W28A, and W31A) within the landfill, reflecting the.
scattered pattern of disposal practices throughout the history.of the
landfill operations. At this point in time, the Pit area shows the
most serious ground water degradation and is the dominant source of
contaminants, notably volatile organics, entering Coon Creek. Conta-
mination in the Upper Sand is most severe near the water table and
decreases with depth, producing a stratified plume (see Attachment 13).
Coon Creek is the primary receptor of contaminated ground water in
the Upper Sand aquifer leaving the WOE Site. No contaminants, .
particularly volatile organics, are detectable upstream of the WOE
Site. Very low levels of some volatile organics are detectable along
most of Coon Creek along the north side of the WOE Site until the
contaminant plume from the Pit enters the Creek. At that point, the
levels of a variety of volatile organics, particularly chlorinated -
volatiles, are present, and persist .several miles down stream of the
Site. Non-halogenated volatiles are obs.erved in high concentrations in
ground water near the Creek and are thought to volatilize quickly upon
entering the Creek. However, the non-halogenated volatiles do persist
when ice cover conditions exist. The levels of volatiles in Coon Creek
where the Pit plllTle enters the Creek are in the range of 1 to 30 ug/1
for several different halogenated volatiles. There is some
contamination present in one monitoring well nest immediately north of
Coon Creek, but th is appea rs to be due to some 1 oca 1 ized unde rfl ow and
reversal back to Coon Creek because of some fine-grained lenses under
Coon Creek. None of the private wells further north of the creek show
any contamination.. ,
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The Lower Sand aquifer has not shown any indications of contamination
to date. A number of factors are responsible for the lack of impact,
including the presence of 10 to 40 feet of a dense till confining the
aquifer, an upward gradient across the till unit, and a pronounced flow
in the Upper Sand aquifer northwards towards Coon Creek. However, the
long-term integrity of the Lower Sand aquifer cannot be completely
guaranteed. The gradient across the till is downward irnnediate1y south
of the landfill and, if ground water conditions were to shift in the
future, the downward gradient may expand. northward under the landfill.
Also, heavier-than-water, non-aqueous phase liquids (NAPL) may migrate
along the surface of the till southward (down the slope of the till
surface) to the zone of downward gradients and, in the long-term,
potentially impact ground water qual ity. . Thi rd1y, most of the
residential wells southwest (and downgradient, in terms of the regional
flow, in the Lower Sand) of the WOE Site are completed in the Lower
Sand and may be impacted if serious contamination were to reach the
Lower Sand aqui fer. The presence of such a 1 arge number of well s
southwest of the Site does have the potential to aggravate the downward
gradient condition southwest of the Site.
E.
Land fi 11 Gas
The WOE Site has 11 gas probes, located primarily along the western
and southern sides of the landfill (see Attachment 5). Probes were
installed at these locations because Coon Creek (along the north and
northeast sides of the Landfill) provides ahydrau1ic barrier to gas
migration and because the closest residential developments are in these
directions. Also, some evergreen trees irnnediate1y along the west side
of the landfill are showing signs of stress. Combustible gas
measurements show the highest levels (15 to 30 percent) in gas probe
nest 6, with a few percent levels in probes 1 and 4. Volatile organics
analyses also indicate the presence of a variety of organics,
principally halogenated organics, in the gas probes. As with
combustible gas, probes GP-1, GP-~, and GP-6 show the highest
concentrations and the largest variety of volatile organics (see
Attachment 16).. These g~s probes are irnnediate1y adjacent to the
landfill and represent the worst case (Attachment 16). Probes further
from the landfill (GP-2" GP-9, GP-10 show much lower vapor gas
concentrations and fewer compounds) and those along the south are
completely clean. The fact that gas migration seems to be very limited
beyond the landfill is due to the relatively high water table
conditions and the high porosity and permeabil ity of the su rfici al
deposits in the area. Some of the levels of individual contaminants
0,1,2, 2-tet rach1 0 roethane, 1,3-di chl 0 ropropene) do exceed Thresho1 d
Limit Values in GP-4 and GP-6 irnnediate1y adjacent to the landfill. In
addition, the levels of some contaminants (methylene chloride, benzene,
trich1oroethene) exceed the potency factors for carcinogens identified
in the Pub1 ic Health Risk Eva1 uation Data ,Base. With the fact that
methane and specific volatile gases are being generated and that the
landfill is a relatively young facility (most ,waste disposed in the
last 10 years), co~cerns do remain regarding long-term migration of
gases. .
-------
7
F.- Wetlands
The wetlands north of the site are listed in the National Wetland
Inventory as a Type 2 wetland (Class Palustrine, emergent,
subject to intermittent flooding, drained). The U.S. Fish and
Wildlife Service has identified the presence of sedges, reed
canary grass, cattails, and willows.
IV.
Potential Receptors and Pathways:
A.
Potential Receptors
Land resources in the area are used for agriculture, residential,
and light industrial purposes. Some land is undeveloped. No
unique agricultural land or wildlife habitat exist around the Site.
(See Attachment 14).
Potentially impacted water resources consist of the groundwater in
the Upper and Lower Sand aquifers and surface waters in Coon Creek
and the Mississippi River. Although used as a source of potable
water in the area, including just north of the Site, the Upper Sand
aquifer is less significant as a potable.water source than the
Lower Sand aquifer. Mississippi River irrigation and livestock
watering are other possible uses of the ground and surface waters.
Coon Creek and the Mississippi River are important to wildlife in
the area and contain fish and other aquatic organisms.
Wetlands between the limit of refuse disposal and Coon Creek,
particularly in the area of monitoring well nests 2 and 13, have
been impacted by seeps and shallow leachate of the Site. Migrating
waterfowl may utilize these wetlands.
B.
Releases
The WOE Site has a variety of exposure pathways, existing or
potential, for the release of hazardous substances. The
existing pathways include ingestion/dermal exposure from con-
tanination of Coon Creek by Upper Sand ground water, and di rect
contact for people on site with exposed wastes and leachate.
There is also the risk of physical injury due to the existing
hazards at the Site (i .e., exposed cables, rusty drums, etc.).
Potential pathways include contaminated drinking water from
contaninated ground water from leakage into the Lower Sand
(i .e., NAPL) or migration beneath Coon Creek within the Upper
Sand. Controls are necessary to protect public health,
wel fare, or the envi ronment from the continuing releases of
hazardous substances. The. releases are described as follows:
.' "'. '.'...
, . ',. " .' .."
:' . ~ .:...~.:"\ ." : ~~". '? :"":r .:~:~ :-~:. \";' .:; ;':',' {:~;.-' :~ - '\,',';"".:' .;: t~" .~.:(~ : ~ ..-:. ~ I/.~ '." -: -~ ~
""',- ',-; '."'"
; ,'-",-"."
........ ".
. - ... '. .
- ." . '.. : ,"":\.'"..'
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C.
B
1.
. Heavily-contaminated ground water within the Upper Sand aquifer,
particularly from the Pit, is currently discharging into Coon
Creek resulting in low but persistent levels of various
chlorinated volatile organics.
2.
leachate seeps are sporadically active near the base of the north
face of the landfill near Coon Creek. When the leachate seeps are
active, they do pose a direct contact risk to people and wildlife
on WOE Site. The leachate seeps ultimately drain into Coon Creek
via interf10w or overland flow.
3.
Landfill wastes, and potentially hazardous wastes, are gradually
being exposed as the existing, unprotected lime sludge cap erodes.
The lime sludge alone does not support any vegetative cover and,
because of the very fine-grain size, is subject to wind erosion
under dry conditions and runoff erosion during periods of even
moderate rainfall. Extensive and deep (up to 10 feet deep)
gullies have developed particulately in the northwest quarter of
the landfill. As the lime sludge cap erodes, the potential for
direct contact exposure to wastes increases over time. Although
the potential for di rect contact is low, there is some undefined
chance for acute exposures.
4.
Ground water contamination in the Upper Sand aquifer greatly ex-
ceeds U.S. EPA Maximum Contamina~t Levels established under the
Safe Drinking Water Act and Water Quality Criteria established
under the Clean Water Act and Minnesota Recommended Allowable
Limits (RALls). The highest levels of contamination are at and
downgradient of the Pit and in isolated/random locations in the
1a'ndfill (so called "hot spots"). Although the ground water
contcrnination is largely limited to the site, being discharged to
Coon Creek, there is one small pocket of contamination exceeding
RALls and nearing Water Quality Criteria, but exceeding only
methyline chloride, in the vicinity of well nest 21, raising
concems regarding the adequacy of Coon Creek as a complete
hydraulic barrier. There are also 10ng-tenn concems regarding
NAPL migration in the Upper Sand, and contamination entering the
Lower Sand aquifer due to NAPL migration or dissolved contaminants
migrating downward south of the Site. To date, no contamination
has been detected in private wells.
5.
Gas, both methane gas from the landfill and individual volatile
organics from wastes, is being released from the Site and
to the west. Gas migration does appear to be limited due to
these high porosity and penneability of the surficial soils.
Exposu re Pathways
The WOE FS defined thi rteen exposure routes from which response
objectives were derived (See Attachment 15). The routes are as
fo 110 ws :
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.: .. .'.:.~. . ';'." :;'. . ;"',:'~"t '
,~.. ',: ," ':~::~:-~: '.."::2:..;'\:~~'~!.'.,,~:,,"."
,: . ':..:. ~:.~' ::: ~~.~.'/ :":':r.:~:'! ~. .:. s' ;~ ;.' i :, ,'{;.:'/ :~ ','1'...',','.:,,: '!' /. .' :;. ,- ' "'\" ~ ',.,.>~ ): -- .
- ',.'.
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-,
. , ;'..:"; ~ :' ','1',"':',. ", / ';'.;-"
: "";'''- .~ .' ~
9
1.
Inhalation of Dust and/or Volatilized Chemicals (dust includes
contam1nants absorbed to dust particles). Three groups of
peo~le are expected to be affected by such a release: on-site
investigators/workers. trespassers. and nearby downwind
residents. The response objective is to control the potential
dust and/or volatilized chemical emissions.
2.
Inhalation of Chemicals as a Result of Incompatible Waste
Reactions. Potential incompatible waste reactions range from
minor reactions that may increase or decrease the rate of
chemical releases from the site to major reactions that release
large volumes of volatilized chemicals. The large volume
release from an undisturbed landfill has. a low probability due
to the slow rate of release of individual containers. the
sorbent properties of the solid waste, the buffering affect of
surrounding soils. and the cool temperatures and anaerobic
conditions in the landfill. No major release has been
recorded. The response objective is to reduce the probability
of incompatible waste reactions and to control the effects of
reactions that may occur.
Inha1 ation of Lime Sl udge Tracked Off-"S.ite by Local Residents
As local residents use the site for recreational activites and
as most of the site is covered by lime sludge. lime sludge is
expected to be tracked off-site and inhaled as dust. The
response objective is to remove the opportunity for contact
with the lime sludge.
3.
4.
Inhalation of Soil Gas Contaminated b the Pit and Landfill.
Lan 1 gas 1S generated at every sanltary andf1 y t e
anaerobic decomposition of solid waste. This gas can be
pushed out into surrounding soils. The gas can also carry
volatilized organic compounds from industrial wastes. Gas
was present in the soil, although no volatile organic
compounds were above detection limits in the ambient air. The
response objective is to control soil gas migration.
5.
Ingestion of Lime Sludge Tracked Off-Site by Local Residents.
As local residents use the site for recreational activities and
as the site is covered with lime sludge. lime sludge is
expected to be ingested. The response objective is to remove
the opportunity for contact with the lime sludge.
Ingestion of Lime Sludge On-Site. On-site investigators/
workers and trespassers are expected to be exposed. The
response objective is to prevent the opportunity for contact
with the lime sludge.
6.
7.
In estion of U er Sand A uifer Water Contaminated b the Pit.
The groun ' water contan1nat10n from the p1t area appears to e
confined to the Upper Sand aquifer and to discharge into Coon
Creek. As the till layer mounds under the Pit. NAPL could
-: ':- " ': . ....' :.~,'. .:. ::.
.' -.':" ".',,':'
':::.~...' ~.. '. .. . .'~~:~' ,.."'.:1., .\...;.!.:-...::.:.~:.:..._~.-:- :-~":-":' \~.t..~-. ";'.'>.. J' ".: -'.~'
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12.
13.
7: '..-:-> .~. .;-.; ':' ':~. "':';J" """:'~...,:: .:.:
10
migrate. off-site in virtually any direction because it will
tend:to follow the slope of the till layer rather than the
g round water flow. The response obj ect ives are to cont ro1
future exposure to Upper Sand aquifer ground water both
from areas that may become contaminated and from areas where
pumping may affect contaminant distributions, and to eliminate,
or minimize, future contaminant releases to Coon Creek and
subsequently the Mississippi River.
8.
Ingestion of Upper Sand Aquifer Water Contaminated by the
Landfill. The ground water contamination from the landfill
also appears to be confined to the Upper Sand aquifer and to
discharge into Coon Creek. As the till layer mounds. under the
1 andfi 11, NAPL cou1 d mig rate off-site in vi rtuall y any
direction. Although specific contaT1ination sources may be less
significant than the Pit, the area impacted, and therefore the
total release, may ultimately be substantial. No receptors
exist between the landfill and creek at this time. The
response objectives are to control future exposure and minimize
future releases to the Upper Sand aquifer, and to e1 iminate or
minimize future contaminant releases to Coon Creek and
subsequently the Mississippi.River.
9.
10.
In estion of Water and Fish from Coon Creek. Low level
contamination from t e site has been found in the creek. The
response objective is to eliminate or minimize contaminant
loadings to Coon Creek.
c.
11.
In stion of Ex osed Waste/Leachate. Trespassers and on-site
invest1gators/workers cou d be a fected by such an exposure.
The response objectives is to prevent exposure to waste/leachates.
Dennal Contact with Coon Creek. Although the creek is not an
attractive water sport stream, children may play in the creek.
The response objective is to el iminate or minimize contaminant
loadings to Coon Creek.
Dennal contact with Exposed Waste and/or Leachate. Trespassers
and on-site investigators/workers could be affected by such an
- ' . . ~'.
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.. :'~f'." <.~ :',; :>.~'~'.:-,::
. "'::-,
. "'-.,'>:":
.';".';,', '.
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. : ..f. .
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V.
11
exposure. The response objective is to prevent direct contact
to exposed waste/leachate.
Alternatives Evaluation:
A.
Response Objectives
The response objectives are listed from the IIExposure Pathwaysll
discussion. above (see IV.C.). as' follows:
1.
Control potential dust and/or volatilized chemical emis-
sions.
2.
3.
Cont rol contact wi th 1 ime sl udge.
Control contact with exposed waste/leachate.
4.
5.
Minimize contaminant releases to the Upper Sand aquifer.
Eliminate or minimize contaninant releases to Coon Creek.
6.
Reduce the probability of incompatible waste reactions.
7.
Contro~ the effects of possible reactions that may occur.
8.
Control future exposure to the contaminated Upper Sand
aquifer.
9.
Protect the Lower Sand aquifer by controlling the vertical
gradient and the impact of heavier-than-water non-aqueous
phase liquid (NAPL) accumulation.
Control soil gas migration.
10.
B.
Alternatives Screened
The Feasibility Study analyzed a wide variety and large number of
alternatives to deal with the various releases identified
previously. The alternatives are: .
1.
2.
No. Action
Capping
a. Nonnal Portland Concrete Pavement
b. Asphaltic Concrete Pavement
c. In-situ Soil Admixtures
d. Sprayed-on Covers
e. Low Penneability Soil Cover Meeting MPCA Solid Waste
Rules.
f. Low Penneability Soil Cover ~xceeding MPCA Solid Waste
Rules -
. . ~ .' , '. ;
. 'J -, ~. '; ',- -'. !.',' ~..' . :...
, ." ," ,"' ~'. "', ~..', ~
- , . ' . . r , . ~ .
..; ,. ~... . ..' ",'. -'
" -: ,"J.,-,,: "'0 ~~.~'.' ::.". ':.,~"-
.~. .:. :.~<-:;',~~.'.~ :.~~::{. t:.:~::.~ :~. ;-::::" -:. ...~:.
. '....., "
. 't ," , .
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9.
10.
12
3.
. .
g. Low Penneability Soil Cover to RCRA Perfonnance Standards
h.Synthetic Menbranes to RCRA Perfonnance Standards
i. Composite Construction to RCRA Perfonnance Standards
Ground Water Cut-Off Wall
a. Slurry Wall
b. Sheet Piles
c. Injected Screens
d. Grout Curtain
4. Ground Water Pumping
a. Treatment Opt ion s
b. Disposal Options
5.
6.
Leachate Collection Drain
Site Grading
Waste Removal (Excavation)
7.
8.
Deep Well Injection
Inciner.ation
Landsp read i ng/ B iot reatment
11. Temporary Warehousing
12. Off-Site Hazardous Waste Landfill
13. On-Site Hazardous Waste Landfjll
14.
Landfill Closure
a. Rodent Cont rol
b. Maintenance
c. Final Cover/Vegetat ion
d. Gas
e. Drainage
All of the altematives were screened in the Alternatives Report (dated
April 18,1986), with some alternatives being eliminated from further
consideration. The remaining alternatives, which are discussed below
under "Alternatives Considered" (see VII.,B., below), were more fully
evaluated in a Detailed Analysis Report (dated October 9, 1986).
C. Alternatives Considered
1.
No Action - This alternative discusses actual and potential
impacts caused by contamination from the Waste Disposal
-------
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"", ", ,".,
13
Engineering (WOE) Site if no cleanup actions are taken.
used as a baseline against which other alternatives are
and includes site monitoring. The alternative includes
tenn monitoring and covers the following:
It is
com pa red
10ng-
Contaminant monitoring in the Upper Sand aquifer
through wells along the landfill perimeter, primarily
downgradient of the wastes, and within the landfill to
act as an earl ier warning Qf releases of contaminants
(includes residential wells). '
b. Contaminant monitoring in Coon 'Creek.
a.
c.
Monitoring through wells of the Lower Sand aquifer to
assure contamination is not occurring and to monitor
gradient between the Upper and Lower Sand aquifer.
d.
NAPL monitoring wells with sumps to collect NAPL.
Wells are proposed for known areas of higher level
contamination. In addition, a geophysical
investigation is proposed to locate low areas around
the landfill where additional monitoring can be placed.
e.
Monitoring of gas migrating beyond the landfill.
2.
f. Background wells in the Upper and Lower Sand aquifers,
and in Coon Creek to define ambient conditions in areas
not contaminated by the landfill.
Capping - This alternative involves placing a low penneabi1ity
cover over the area of concern. The cover would be vented to avoid
gas build-up. The cap would eliminate the opportunity for direct
contact with the waste, stabilize the waste pile, discourage
rodents and other vennin, ,control odors and vapors, control surface
run-off, control dust, promote vapors, transpiration, and control
the percolation of water into and through the waste (infiltration).
The more water going through the waste, the more leachate
(contc:rninated liquid) produced. There were five capping
alternatives considered:
a. Low Penneability Cover Exceeding Minnesota Pollution Control
Agency (MPCA) Standards. This cap consists of grass
vegetated cover, over 6 inches (") of topsoil, over 6" of
sand lateral drainage [hydraulic conductivity (K) around 1 X
10-3 centimeters per second (cm/s)], over 24" of compacted
clay (K less than or equal to 2 X 10-6 cm/s).
b.
Low Penneability Cover Meeting Resource Conservation and
Recovery Act (RCRA) Perfonnance Standards. This cap consists
of grass vegetated cover, over 6" of topsoil t over 30" of clean
fill, over geotextile filter fabric, over 12" of sand lateral
. " -' ~ '- , , ","""'",':,:',:,', ','. :,'~~,',. ,J-,', ,',-', ':,";..,' :,~':~,;>" -: I ',:"' .': '". :";"'.,::~ ::.,:,: .,:<: ':.:~ ~..~, ::....::,~~.: ):f ~. - ".~.~. . : '.>:' ~~, :~. j~., ,:-:"':; ~.~~??<:'."':.. .."':, :.~ ."
.'.i."" <,- '.. ~":.r. -:-:,'~'::.;.."": ;,... ',",
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14
c.
drainage (K greater than or equal to 1 X 10-3 an/s) , over 24"
of compacted clay (K less than or equal to 1 X 10-7 an/s).
Synthetic liner Meeting RCRA Perfonnance Standards. Cap
consists of grass vegetated cover, over 6" of topsoil, over
12" of clean fill, over geotexti1e filter fabric, over 6" of
sand lateral drainage (K greater than or equal to 1 X 10-3
cm/s), over high density polyethylene synthetic liner, on 6"
of sand cushion..
d.
Composite System Meeting RCRA Perfonnance Standards. This cap
consists of grass vegetated cover, over 6" of topsoil, over 24"
of c1e-an fill, over geotextile fabric, over 12" of sand lateral
drainage (K greater than or equal to 1 X 10-3 cm/s) , over high
density polyethylene synthetic liner, over 6" of sand cushion,
over 24" of compacted clay (K less than or equal to 1 X 10-7
cm/s).
e. lime Sl udge Meet i ng RCRA Technical Perfonnance Standa rds. Thi s
cap consists of grass vegetated cover, over 6" of topsoil, over
30" of clean fill, over geotexti1e filter fabric, over 12" sand
lateral dra-inage (K greater than 0-" equal to 1 X 10-3 an/s)
over 36" of 1 ime sl udge (K 1e~s than 2 X 10-6 an/s).
3.
. ?roundwater Cut-off Wall with Cap. This alternative involves a cap
(see item 2., above) and a low penneability perimeter barrier which
would be keyed into the red/bro~ silt till (the till layer between
the Upper and Lower Sand aquifers). The perimeter barrier wall
would consist of a soil-bentonite slurry wall which will contain
contaminants within the wall. To insure an inward gradient across
the wall the groundwater level within the wall would be kept lower
than outside the wall. If a leak occurs the inward-gradient will
cause water to flow into the walled area thereby avoiding
discharges outside the wall. Two methods of maintaining the
inward gradient are:
a. Groundwater Extraction Wells. The water level within
the wall is- lowered by a pump-out well.
b. Groundwater Collection Drain. The water level within
the wall is lowered using perforated pipe connected to
. a sump. The water in the sump would then be pumped-
out.
4.
a. Groundwater Pumping With Cap. This involves wells to
intercept and extract contcrninated groundwater from the
Upper Sand aquifer downgradient of the waste site.
-------
, : :'" ....', ~ , " .~' ::, ~/ , ,:.
15
5.
b. Groundwater Collection Drain. This involves perforated
pipe to intercept the flow of groundwater downgradient
of the waste site. The pipe leads to a sump. The
sump is pumped-out to extract the water.
Excavation of the Pit. This alternative involves removal of about
5500 cubic yards of material, inc1 uding drurrmed wastes and
contaminated soil. Removal is,expected to occur at least to the
asphalt lining of the Pit. Oi$posa1 is expected via one or a
combination of the. following: .
a. On-site RCRA facility. This would involve redisposa1 of
wastes consistent with RCRA at the site.
b.
Off-site RCRA facility. This would involve trans-
portation and disposal of wastes at an existing
compliant facility away from the site.
c.
Incineration of wastes in a rotary kiln incinerator opera-
ted at the site. liquid wastes from quenching and scrubbing
would be collected and disposed at a RCRA facility or .
treated and discharged. Residu~l materials remaining after
incineration would be disposed. at a RCRA compliant facility
or del isted 'and buried on-site.
,
6.
Excavation and Disposal and Groundwater Pumping 0' the Pit Area.
This alternative is a combination of items 4.a. and 5, above.
7.
Treatment of Ext racted Groundwate r.
Ai r Stripping. By exposing contaminated water to the ai r
volatile compounds are removed from the water. This
alternative is often used for low level volatile compound
contamination or to reduce or el iminate some contaminants
prior to treatment with other processes such as activated
carbon. As contaninants are discharged into the atmo-
sphere, activated carbon treatment is often requi red of
the contaminated air before it is discharged into the
atmosphe re. .
b.. Carbon Adsorption. Contaminated water is exposed to the
activated carbon. The carbon removes contaminants and must
be repl aced periodically.
a.
c.
A combination of a) and b), above. These technologies can
be used together to reduce ai r poll ution caused by ai r
stripping via activated carbon, to increase the life of the
activated carbon by air stripping, or to increase contami-
nant removal efficiencies.
8.
Di sposal of Ext racted Groundwater.
. '. -.: :, ~".' :;,~.~..<;.~) '.~. .;' : Y;;'.. :~ :'::"-' : .';" , ,
'. ,. .."';,"',~ :~,:.: ,.,; .: '.: -,:~":<~f~;: '~','!.. ,f.., .::;. .
: .:.-: .~~J' ~;. './:': "~:'.'!""". .' ~" ',: :..... ~ <~; ':.. . ''': .:'." '.~':' :. "." ,'::-:/: ~:'...\.-:,,::~ :::;":,';'
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16
a.
Coon Creek.
Creek.
This involves direct discharge to Coon
b.
Publicly Owned Sewage Treatment Works. This involves
discharge to a nearny sanitary sewer. which would
discharge to the sewage treatment plant.
c.
Infiltration. This involves discharge into an in
filtration pond. which allows treated water to reenter
the Upper Sand aquifer.
d.
I rrig at i on/Evapot ranspi rat i on.
appl ication of the discharge.
This involves land
or Relevant and A
ro ri ate
Altematives 2. 3 and 4 involve capping the Site. Resource Conser-
vation and Recovery Act (RCRA) requi rements for closure of a RCRA
landfill is an ARAR for capping the Site.
Altematives 3 and 4 in.volve groundwater extraction and discharge.
If discharge is to Coon Creek (altemative 8.a.) or land application
(altemative B.d.). National Pollutant Discharge Elimination System
(NPDES) pennit requi rements are an ARAR. If discharge is to the.
sanitary sewer (altemative B.b.) an agreement with the Metropolitan
Waste Control COlT1T1ission (MWCC) in accordance with its pretreatment
program under the Clean Water Act is an ARAR.
Altematives 2. 3 and 4 must attain Anny Corps of Engineer 404 pennit
requirements for construction of the cap in the floodplain. Filling of
wetlands in the floodplain must also meet these requirements.
Altematives 1. 2. 5 and 6 would allow continued discharge of
contaminated water to Coon Creek where Water Quality Criteria and
drinking water standards (for the Mississippi River) would apply.
Altematives 2 through 8. would involve ai r emissions either through
excavation or through ground water extraction and treatment which must
be considered under the Clean Air Act and State requirements.
E.
Reduction of Toxicity. MObility. or Volume
Altemative 1 does not reduce toxicity. mObility. or volume.
Altemative 2 will reduce the mobility of contaminants in the waste and
the volll11e of contaninants entering the groundwater by restricting
infiltration through the waste. Because the volume and mobility of
contaninants is reduced. the toxic ity of the .contani nated g roundwate r
is reduced.
, '.:;} -' :;.:"~'." '<', ,{ .", :':~".'~::; '>
~ "-,.., .
':', "''-~'''', ~~,:,: .,;.( '.,: ~,'.(:, ;:~f:~' ~~'.; .( f' .', '.=~:
. _.~. ,- '. 'I' .. ';"':,'. ,'.'.... ";.' '.,:: ,'~" "..~.:",...~,~":,, ~:,'::":"'~: -':t'~';~)\'?:':::"':::2?:,:,;;~.({.t,;,.;,~'~~!"
'.: ~-:.- -...-. ';',:",/:': ~'_":>~';'-'''',.
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17
A1temative 3 has the advantages of altemative 2 plus it further
reduces the,mobi1ity, toxicity and volume of contCl11inated groundwater
and NAPl discharges off-site by containing them within the barrier. A
concem is that if not extensively monitored, NAPL discharges may pool
along the barrier wall and that the weight of the NAPL will cause it to
penetrate and contCl11inate the Lower Sand aquifer. Consequently, the
barrier is considered more desi rab1e for a smaller area which can be
more easily monitored (i.e., the Pit).
A1temative 4 has the advantages o'f a1temative 2, plus it further
reduces the mobility, toxicity, and volume of contCl11inated groundwater
by creating a hydraulic barrier to contain such contamination on-site,
as well as reduce it through groundwater extraction. This alternative
does not contain NAPL discharges.
Altemative 5, by exposing deteriorating drums of incompatible wastes,
has a potential for causing a significant increase in the toxicity,
mobil ity, and volume of contaminant discharges to the ai rand
groundwater during the excavation and handling of wastes. The 10ng-
tenn reduction of toxicity, mobility and volume of contaminants from
the material excavated would be significant, after the risks of
excavation are experienced. This would not affect contamination of the
groundwater from the rest of the landfill. '
Altemative.6 has the benefits of altematives 4 and 5 for the
contCl11inated groundwater around the Pit area.
F.
Sho rt-te nn Effect iveness
Altemative 1 would not be effective in addressing contamination
from the site. It would monitor conditions at the site.
Altemative 2 would cause short-tenn impacts due to construction of the
cap. These would include noise from heavy equipment, dust, and
increased chances for di rect contact with wastes by construction
personnel. If the lime sludge is not used, exposure of wastes, and
removal and disposal of the lime sludge would cause additional risks.
The chances for contact with wastes, contCl11inated gas releases, and
infiltration through the wastes would be reduced by the cap.
Altemative 3 would pose risks associated with a1temative 2 pl us risks
to workers placing the barrier wall. Groundwater contamination and
NAPL discharges within the barrier would be contained. NAPL levels for
the Pit barrier altemative would be reduced, as needed, within the
barrier by extraction wells.
Altemative 4 would pose risks associated with alternative 2 plus some
minimal short-tenn risk during construction to workers. Groundwater
contamination would be contained and reduced through groundwater
extraction. NAPL would not be contained. :
...~',~'~"~~'.<"~','.:.,::':,,:..:. .:. :':",
.':,P"',/':"~:,~'.'- ,:~,:...'~:-;,.:.~:':""''''/.' '..,,:....' ',,-.r .,:."r"::.
'./"; ::';,!'":."~.. .
p.. ',: .' ,: ~ , .:-~: ::.., '. .-,.~' ':. . '7'~'. ..'" ;.
,.--:. ~'. "}:..,:~; - ..'~'..t:.~~,: ;:;;..1 :{l :;,~:"2;:~l:~;'.;;',; .~{:~.::
-------
18
Alternative 5 would pose significant short-tenn risk due to the
excavation and handling of incompatible wastes. Work" rs , local
populations, the ai r, groundwater and surface water could be impacted
by short-tenn discharges.
Alternative 6 has short-tenn impacts of alternatives 4 and 5 except
that to the extent the sources of NAPL are removed without incident,
there would no longer be sources o~ NAPL from the Pit.
G.
Long-tenn Effectiveness and Permanence
Alternative 1 would not be effective in addressing contamination from
the site. Continuous professional management would be requi red to
assure that responses could be initiated based on the monitoring. The
detennination and timeliness of required actions would also be of
concern. The reliability of this alternative alone is suspect due to
the complexity of the management requi red.
Alternative 2 would require 10ng-tenn care of the cap. The
chances for contact with the wastes, contaminated gas releases,
and infiltration through the wastes would be reduced. The lime
sludge cap has greater 10ng-tenn risks due to uncertainties in
the use of 1 ime sl udge. Its advantages are it is a1 ready
on-site, and if not used, would be a significant disposal
problem as -it would need to be removed. .
Alternative 3 would requi re care and monitoring of the barrier
wall. Groundwater contamination and NAPL within the barrier wall
would be contained. For the landfill, where NAPL could accumulate
undetected against the barrier wall due to the lenth of such a wall,
there would be additional concern due to the potential that such an
event could cause contamination in the Lower Sand aquifer over the
long term. NAPL accumulation is expected to be detected by moni-
toring wells and controlled by pumping out those wells within
the smaller Pit barrier, if necessary. Any breach in the wall
could be discovered by the increased pumping rates necessary to
maintain an inward gradient across the wall. Replacement would be
expensive.
Alternative 4 would require minimal additional construction.
Groundwater interception and extraction is commonly used,
re11abT-e, and rep1 acing well s is rel ative1y inexpensive.
Long-tenn operation and maintenance is required. Groundwater
contamination is contained and reduced. NAPL is not contained.
Alternative 5 would requi re 10ng-tenn care of any excavated
contaminated materi al s remai ni ng on- site. If di sposed off-site, ri sks
due to transportation, accidents, and redisposa1 would occur. If
contained on-site, some leakage of the containment facility and
spreading of contamination is possible, although less than from the
existing Pit. Long-tenn care would be required of an on--site facility.
.~,. '..~.. ... '4" , . ','. .7'~ ...~:,.J,:::.;''':'~....:.....);.~.::~;'''''~''~;t:.'...~i'.'~~._-;f.~~".'.i;";:::'::..'t':'.~~>";i:;.,t{:::'::-:"".":::'~""~;:.\~?~r~~~.>:';\'::-::"';',:'.'.!.~~-.>:
'~;.'.;.\~:'~..:.:.,~~-:...'":":.'~ ":~\~":<'~'::::'.::' :J.:~'~,»...,:,,:'''.:.'\~.:,:~~'>,: ~~:~ ':;:~' ~ ':,':': ~','~'.~~' ..' :.,,-.: .'.::. ',.~ ':':;""-:\.<:~~; ~., ..: " ,
-------
",," '-;':: . " ',. ~"'" : .":... \f -' . ~
19
Long-term NAPL discharge from excavated materials would not be
expected.
Alternative 6 is a combination of alternatives 4 and 5 for the Pit and
would have the same impacts.
H.
Imp1ementabi1ity
Alternative 1 is easily implemented, but less reliable than
other alternatives.
Alternative 2 is cOl11T1on and easily constructed. Caps utili-
zing 1 iners would be more difficult due to the need to reduce
slopes such that the liner would not tear.
Alternatives 3 and 4 would be requi red to meet National Poll utant
Oi scharge E1 imination System (NPOES) pennit requi rernents for discharges
to Coon Creek, or an agreement with the publicly owned sewage treatment
works for discharge to the sanitary sewer. Alternative 3 could be more
difficult to construct such that adequate containment is achieved.
Alternative 4 is common and easily constructed. Capture zones can be
measured to assure agequate coverage. NAPl would not be addressed.
Alternative 5 would be difficult due to the need to excavate the
wastes, and, in the case of incineration, site an incinerator.
Also, some wastes may be prohibited from being landfilled.
Alternative 6 would be the same as 4a and 5 except NAPL would
be addressed if not caused during excavation.
Alternative 8a would be rel iable and would requi re the equivalent of an
NPOES pennit. Implementability is expected to be easy, however this
cannot be assured until the permit conditions are known during design.
Alternative 8b would be reliable and would require compliance with the
pretreatment requi renents of the POTW. Implementabil ity is technically
easy, however problems with acceptance by the POTW due to the dilute
nature of the waste stream and depletion of the area's growth capacity
allocation at the POTW are concerns. -
Alternative 8c would be easily implemented, outside problems with land
aquisit1on, but causes concern due to the addition of water to an area
of the Upper Sand aquifer, just south of the Site, where a downgradient
exists between the Upper and Lower Sand aquifers. This would also
increase concerns about creation of a downgradient under the landfill
itsel f.
Alternative 8d would require the equivalent of an NPOES pennit, but is
not considered reliable for the cold climate at the Site.
1.
Cost
.,~..r ":".; ".--.:,.~.~..:-..-
~.' '.: ..". '.- "";; _:.,
, :'~":' ~ ,.>:' .":. '''f. . :~:,~,,--,.... -,~ ~~"~., ~;:-'''~ : ,:,i',... .':.:'-;;/:'Y :'.' }';: '; }~:,..' ~"~'" .' :""~'.~~: ~ ~,.~'~:_o:;:;~'./ ~\ ~ "';t_.:: 9l':,'r'r.~~.,;~'.~""~j'-~~:":,~:~'r_r;::-,, ~:, ~ :-
-------
20
1. Altemative 1 has a capital cost .for monitoring of $70,000 pl us a present
worth (PW) of operations and maintenance (0 & M) of $647,529 for a total PW of
$717,529.
2. Altemative 2 costs are as follows:
Type of Cap
Capital Cost
of Cap
a. Cap meet i ng $ 4,697,280
MPCA Stand a rds
b. Cap Exceeding 9,101,736
MPCA Standa rds
c. Soil RCRA Cap 12,709,760
d. Synthetic Line~ 12,652,220
RCRA Cap
e. Compos ite RCRA 19 , 119 , 365
Cap
f. Lime - sl udge 8,196,500
RCRA Cap
PW of 0 & M
of Cap
Total PW
of cap
Total PW
including
man i to ri n1
(altemative 1
235,673
4,932,953
5,650,482
235,673
9,337,409
10,054,938
235,673 12,945,433 13,662,962
820,107 13,472,327 14,189,856
235,673 19,355,038 20,072,567
235,673 8,432,173. 9,149,702
(The Pit was also considered alone. However, since the
Pit was found to have several feet of clay capping
al ready, no additional cap was needed. Had the clay not
been there, a less penneable cap might have been needed for
"the asphalt-lined Pit to keep water from accumulating in the
Pit.)
3. Estimated costs for altemative 3 are as follows:
a. For the Landfill (must also add alternative cap cost):
Type o~ System
Capital Cost
of System
Total PW
of System
i) Groundwater Cut-
off Wall with
collection drain
PW of 0 & M
of System
$ 5,238,996
5,362,749
i i) . G roundwate r Cut-
off Wall with
123,753
4,770,976
4,894,729
123,753
. '-" "."~.:' { I . , .-.;. '.
".' .~ ~'.~.~, . .", - ... . '.'
...,-... ~-:. . ,_,'-.:,:'n"" '",".' ..,'.. '~': .~. "J':-"'.. ,,'c.-'.,,""''''.
h'~'",'" ...",....~- ..~. ~"':'~'I..r'-'. -~~" ",,~,.,,'~-'....,' ''''. :"'. '.""','.
-------
, :'" "-::r.l.""~. ~. < . 4'
extraction well
b. For the Pit:
i) Wall with drain
i i) Wall with well
4.
21
389,536
302,723
Estimate costs for altemative 4 are-as follows:
.~s ':'
a.
For the Landfill (must al so add cap cost):
i) Groundwater Pumping
with Extraction well
ii) Leachate collection
b.
For the Pit:
i) Well.
1 i) Drain
5.
812,000
1,452,500
127,120
Estimated costs for altemative 5 are as follows:
201,495
a.
Exc av at i on and Off-
site Landfill
i) Emelle, Alabama
ii) Chicago, Illinois
b.
Exc av at i on and On-
site Landfill
c. Excavation and On-
site Incineration
6.
2,810,851
1,963,851
645,051
6,275.,851
Estimated costs for altemative 6 are as follows:
a. Excavation and Off-site
Di sposal with Groundwater
Pumping
i) Erne 11 e, A 1 ab am a 2,935 , 171
i1) Chicago, Illinois 2,088,171
b. Excavation and On-
site Disposal ~ith
Ground wate r Pum pi ng
744,171
86 ,308
475,844
86,308
389,031
41,478
853,478
41,478
1,493,978
90,498
217,618
51,376
252,871
37 ,708
37,708
37,708
2,848,559
2,001,559
682,759
37,708
6,313,559
41,478
41,478
41,478
2,976,649
2,129,649
785,649
':::.~ -:"::"". ~{:~"::'. ...>-:..-,;'::0. .r."
. ,:'; ~:.. . t'" :':';: - ~ .f'/:",".- ;::,:" .' ,",~':~'i","'::'..,:".,:_:\_..,~~ r "," ...: :':" r;Y;~ :~:::fo:~-.~ . ...;,'..~r:~" '-,~"':'~~.', ;,~ ;".;:0" ;'~"', :..;,....:: -, "\~~;:'.~:-" ,.,:. '';.'1'' <..~.. ~.';: ," "'\.
-------
a.
22
7.
,Estimate costs for alternative 7 (ground water treatment) are as follows:
For the Landfi 11
i)
Carbon Adsorpt ion
*) Ground water pumping
**) Ground water plJ'Tlping
within cut-off wall
91,000
91,000
470,138
355,295
561,138
446,295
ii)
Ai r Stripping
84,000
347,953
263,953
b. For the Pit
i)
Carbon Adsorption
*) Ground water pumping
**) Ground water pumping
within cut-off wall
8.
a.
i i i )
iv)
b.
i )
i i)
i i i)
iv)
~ . . '. 'j :..
91,000
162,319
253,319
135,670
91 ,000
44,670
ii)
Ai r Stripping
84,000
128,306
44,306
Alternative 8 (ground water disposal) estimated costs are as follows:
For the Landfil'l
i)
i i )
Coon Creek
Sewage Treatment
Plant
Infiltration
Pond
Irrigation
28 , 700 381,789 410,489
413.,280 488,125 901,405
256,500 245,099 501,599
322,000 324,285 646,285
For the Pit
Coon Creek
Sewage Treatment
Plant
Infiltration
Pond
I rrigat10n
28,000 362,936 390,936
371.,280 265,160 636,440
97,500 245,099 342,599
189,000 324,285 513,712
J. Community Acceptance
The community has been involved in the planning process as
described later in Section XI. Infonnation in the RI assisted in
the lifting of a well advisory by the Minnesota Department of
Health. Initially removal of the Pit was considered desirable.
However, as discovered during the RIfFS investigation of the site,
there are hazards involved in excavation and the benefits are not ,as'
great as Qriginally thought, considering industrial wastes have
(.;. :~;:::; -:::~.~.~<..~'~;~~ ,~'''l',: ;:: ~i'r~.
~~..~. :.'~;
" .....'
I
....., "
"
.. . '\"':. ;:.~.:r'''''\:~':':~~:A'''' :.;,:;-:':;~:i"':'::~;~~,)..~..").'
..:~~ . :. . \~:
-------
23
been disposed throughout the landfill t not just in the Pit.
PresentlYt there is concern that sewer capacitYt and therefore
growtht ;s adversely affected if extracted ground water is
discharged to the sanitary sewer. The timeliness of the process
has also been questioned.
K.
State Acceptance
The MPCA has approved the Detailed'Analysis Reportt as modified: under
the Consent Order. That reportt as modifiedt includes the selected
altemativ~s described herein as its recommended altemative.
L. Overall Protection of Human Health and the Environment
1.
','
'.', ~ ,'..'" . "'- ." '':'., .';. ',' .;. " . .: ~ .~.' '" to .; i.. ~ .~!:., ' ".:'-
Ability to Meet the Response Ob~ectives Listed in V.A.t
Above:
a.
No Action (altemative 1). This altemative providest through
monitoringt infonnation on which the need for response could
be madet although the long-term management requi red to
dete nn i ne when and what response is call ed fo r t and the
time1 iness of such response are concems. It does not provide
protection of any receptor or potential receptor of contami-
nated releases.
b.
Thfs altemative does not meet any of the 1 isted response
obj ect i ves.
Capping only (altemative 2). A cap would meet objectives It
2t and 3 by covering the landfill. Objective 10 would be
achieved by vents in the cap. Objective 7 would be met
somewhat by the bulk and weight of the cap. Over the long-term
a cap would reduce contaninant releases to the Upper Sand
aquifer (partially addressing objective 4) by reducing
infiltration through the landfill. Reduced contaninant
releases to the Upper Sand aquifer would reduce Coon Creek
releases (partially meeting objective 5). Objectives 6t 8 and
9 are not met by this a1temative.
Capping altematives vary mainly in the amount of infiltration
they allow into the landfill.
c. Groundwater Cut-Off Wall with Ca and Groundwater Extraction
e a temat1ve a. 1S a temat1ve wou conS1st 0 a capt
a-cray cut-off wall around the entire waste area which would be
keyed into the till layer, and a ground water extraction well
to maintain an inward gradient within the cut-off wall such
that in the event of 1 eakage th rough the wall water wou1 d flow
intot not out oft the walled area. This altemative would meet
all of the objectives of capping (see item b., above). In
additiont objective 4 would be met to a greater degree. A
major known source area which contributes to the primary
..":" :i..:-,,-;;..--...>-~., ...;: 'r;.).,,;:~.f.':~':" ;"",:,:::."~"~<;"'.:
.: .:'-~..,~~".~;.,~-,;, "';:~:":: .
'. .":' ,,,,," :.:"
. :. ~".: ..; .', . ','. 7.. :":.~' '''; '. :' .:.\... "".(.,
... .. ".
", ". ~, . ':.,~.. ".' .
-------
.7::-::'1' "\' :':'
. ..\...'
':~'..:..' :':~.~':,
24
contaminant plume in the Upper Sand aquifer would be contained.
Objective S would be met as the Soun:e of contarnanents to Coon
Creek through the groundwater would be eliminated through
containment. For the Pit, a small area," the NAPL would not be
allowed to accumulate significantly due to the monitoringjpump-
out wells (objective 9 is met for the Pit area only). For the
landfill, due to the larger area enci n:1ed by the wall, it is
possible that NAPL could accumulate along the wall without
detection, increasing the probability of contamination of the
Lower Sand aquifer (objective 9 is not met). : NAPL would not be
allowed to migrate along the till away from the walled area
which reduces the chances of exposure to the NAPL (objective
8). Objective 6 is not met by this altemative, nor is the
maintenance of an upward vertical gradient.
d.
Groundwater Cut-off Wall, with Ca and Groundwater Collection Dra;n
a tematlVe 3 T 1S 1S Slm1 ar to 1tem c., a ove.
e. Groundwater Pumping with Cap (a1temative 4a). This is sim"i1ar to
item c., above, except that object ives 8 and 9 are not met because
NAPL would not be contained.
f.
g.
Leachate Collection Drain with Cap (a1temative 4b).
similar to item e., above.
Excavat'ion and Off-site Disposal of the Pit (alternative Sb).
Excavation of the Pit poses the greater risk of significant short-
term releases associated with objectives 1, 2, 3, 6, and 7 due to
excavation activities and handling of wastes while exposing them to
the air. This a1temative meets objectives 4, S and the NAPL
portion of objective 9. Objective 8 is met to the extent that NAPL
discharges are eliminated. Objectives 1,2,3,6 and 7 would be
met in the long-term after th~ short-term risks are endured.
This is
h.
Excavation and On-site Disposal of the Pit (a1temative Sa). This
is s im il a r to item g Of above, except ove r the 1 ong-te rm the re is a
continuing potential for remaining wastes to leak, which would mean
objectives 4 and S would be met to a lesser degree. "
i .
Excavation and On-site Incineration (alternative 5c). This is
similar to item g., above.
VI.
Selecting the Recommended Altemative
The Detailed Analysis Report, prepared by potentially responsible
parties in accordance with a Consent Order issued by U.S. EPA and
MPCA, recommended implementation of the following altemative response
action which, in concert, are expected to re1 iab1y and cost-effectively
protect pub1 ic health, we1 fare and the envi ronment by physically
iso1 ating the buried waste to e1 iminate di rect cohtact exposures and
minimize liquid migration; to capture, remove, and treat all
".~ ~,~ ~.:. .~ ". ,'. ;~,_: ~:, -f ~..:! f.:~;~~:'
" . :~"::,' v':~... :.-; .!~":,
", r".."" .'
"'.
:; .;,~;~ :'. ',::':'" ,:~~:.': '.~
, ;. '.:. " .: /. .',",. ~';J,oJ
.' ,. .' ,. '
",' .<,:~~':',i:~":'>;/'::,"",:'"
'J ",.~.
-------
25
contaminated ground water currently leaving the WOE Site and eliminate
releases of hazardous substances to receptors; to prevent the migration
of NAPL. from the Pit area; and to monitor and control gas migration
from the Site. The selected remedy consists of:
A. Extensive monitoring program to monitor for gas, dissolved
contClTlinants, and NAPL at the perimeter of the WOE facil ity.
B. Installation of a soil cap, incorporating the existing lime
sludge at the WOE Site as the low permeability layer, which will
meet RCRA Performance Standards.
C. Installation of a ground water extraction system along the northem
boundary of the facility to intercept contClTlinated ground water leaving
the WOE Site and currently entering Coon Creek.
O. Treatment of contaminated ground water using air stripping
and/or activated carton (possibly with pretreatment for other
. contaminants). Treated water will be discharged to Coon Creek.
E. Institutional controls to: 1) avoid wells near and under the Site
in the Upper Sand aquifer, and; 2) as a precautionary measure to be
considered to limit additional wells in the Lower Sand aquifer near the
Site to help assure continued maintenance of the upward vertical
grad i ent b~tween the Uppe r and Lowe r Sand aqu i fe rs.
The Detailed Analysis Report was approved with modifications by the
MPCA and U.S. EPA. The most significant modification was to add
another component to the set of response action altematives
recontTlended in the DAR. The additional response action involves the
installation of a slurry wall around the Pit (keyed into the red-brown
silt till) and a sepa rate ground wate r pump-out and NAPL cont ro 1 system
exclusively for the Pit. In addition, the cap is upgraded to be more
in conformance with RCRA technical guidance standards. Thi rdly, a
geophysical survey will be conducted to better design the NAPL
monitoring network. Fourthly, the overall gas and ground water
monitoring network is upgraded to cover the perimeter of the WOE Site.
Finally, a wetland between the WOE facility and Coon Creek will be
filled because it does receive periodic leachate discharges and will be
replaced with a newly constructed wetland.
The recontnended altematives, in concert, deal with the
WOE Site as a whole because of the size of the former facility
(up to 40 feet of wastes over 73 acres), the disperse nature of
concent rated sou rces of haza rdous waste (known and unknown II hot
spot s II), and the dete ri a rat i ng cond i t i on of the present site
cover. Much attention was focused upon excavating the Pit
because its location is well defined and it is clearly having
a significant current impact on ground water and Coon Creek.
However, the Pit represents 10% of the hazardous wastes
disposed at the Landfill so excavation of the remaining wastes
from' the Pit would not make a significant difference in' the
':~ . 0.." '-;..: .'r:'.,~.~:.~ '/':~. ',"~~":.
;: ~. ~'\".',,'~". '- ,~:.:.:.,~. "':.'';.~', <..' .' ...~
. :'. . . .." ,;:..,
" -': '.: .~ ..
.~:::. :;.:; :", :.':' < . :'. "',,;': >
:.:, ',', -.:'j.;"<..:' .'-.:::..' .;;''''..,:',:'I''':'''~'~:'~:.;~;:~~~'.~'',~:~.~:f>:';~'~;:;~{;~~:'{:"::'~~~? :'!J
-------
26
long-term when looking at the site as a whole. The
concentration of wastes in the Pit, including acids, caustics,
cyanides, flammables, and solvents, does pose a seve~ safety
risk to workers and the surrounding ~sidential areas due to
reactions of incompatibles. A test excavation of the Pit
conducted in June, 1986, indicated that many of the wastes are
in deteriorated containers or have al ~ady been ~leased from
ruptu~d containers. Many of the ~actives are in plastic
containers and a~ extremely diffitult to locate by detecting
equipment or excavation equipment. Even if wastes were
excavated successfully from the Oit, some wastes will be
extremely difficult, if not impc~sible, to dispose in the near
futu~ and this situation is aggravated even mo~ by the
implementation of RCRA amendments, including the "land ban,"
which prohibits land-filling certain types of wastes. The
costs for excavation of the Pit and disposal are estimated to
range from $ 0.7 to 6.3 million dollars, depending upon the
di sposal method (on-site 1 and di sposal, off-site 1 and di sposal ,
incinerators). Since landfilling the excavated wastes (on-site
or off-site) may not be implementable due to land ban
considerations, the $6.3 million for on-site incineration is
probably the mo~ ~alistic cost estimate for disposing the
excavated wastes. Also, off-site land disposal is the least
prefer~d option for deal ing with these wastes per Section 121
of CERCLA. , Even with the excavation of the Pit, ~sponse
actions for the enti~ WOE Site (adequate cap, ground water.
ext ract i on and t ~atment system, gas mon i to ri ng, ground wate r
monitoring, NAPL monitoring) a~ necessary, in large part due
to the d i spe rse and unknown patte m of past waste disposal.
Containment of Pit wastes, in combination with the other
~sponse actions, will accomplish the same overall objectives
as excavation of the Pit. Excavation of the pit would only
eliminate the need for a slurry wall about the Pit. Because of
the obvious safety concems, disposal difficulties with
excavated wastes, high cost ($6.3 million), and remaining need
for other ~sponse actions, the effectiveness of excavation is
minimal. However, some control of the ~lease from the Pit
would be effective in ~ducing the existing impact on Coon
Creek and mitigat.e any NAPL releases that may occur. A slurry
wall around the Pit, with its own ground water extraction
system and NAPL monitoring/extraction system, win minimize the
continued release beyond the Pit and win "avoid the severe
safety risks and disposal problems faced with excavation.
A wide variety of capping altematives we~ evaluated. The
fact that the site is a fonner, but ~cently active landfill,
necessitates the use of flexible, self-healing caps to cope
with diffe~ntial settlement. This condition rules out the use
of non-flexible covers (cement, asphaltic - concrete, soil
admixtu~s). The fact that hazardous wastes we~ disposed at-
the Site throughout the landfill justified the need for a cap
meeting RCRA ~quirements, thus ruling out conventional
~
-------
27
landfill caps. However, the p~sence of up to 8 feet of lime
sludge over the Site poses difficulties in placing a new RCRA
cap. ReBIOva1 of the lime sludge would ~sult in a disposal
problem of the lime sludge and potentially expose waste. On
the other hand, the 1 ime sl udge has very low hydraul ic conduc-
tivity (10-5 to 10-6 em/see) and excellent self-healing
p rope rt i es. The ~ is a t rernendous adv ant age to i nc 0 rpo rat i ng
the lime sludge into a RCRA design cap. The cap will consist
of a minimum of 36 inches of stabi}ized lime sludge, overlain
by a 12-inch sand lateral drainage layer, overlain by a 30-inch
layer of general fill, and completed with a 6-inch layer of
topsoil that would be vegetated (see Attachment 17). The
Remedial Design will incorporate some adjustments in surface
slope, slope of drainage layer, grain size of fill, and
thickness of lime sludge in order to meet RCRA perfonnance
standards.
The cap will completely cover the presently defined limits of
waste disposal (73 ac~s) and will incorporate the existing
1 ime sl udge that wou1 d othe rwi se have to be di sposed. It wi 11
minimize the migration of liquids, provide excellent
rodent/vector control, e1 iminate exposed wastes and leachate
seeps. The fact that the~ a~ wastes below the water table
and liquid wastes (bulk and containerized) we~ disposed
throughout the landfill necessitate the need for extensive
ground water extraction and t~atment which, in tum. may
provide some flexibility in cap design and performance.
As noted earl ier, ground water in the Upper Sand aquifer
is seriously contaninated and is entering Coon Creek, adversely
affecting the quality of Coon Creek. Wastes are disposed below
the water table and liquid wastes (bulk and containerized) and
sludges we~ dumped throughout the landfill. Although the most
serious contanination detected to date is associated with the
Pit, monitoring wells located within the landfill have
identified other, scatte~d "hot spots". 1:here a~ certainly
expected to be many more, unidentified and unlocated hot spots
buried in up to 40 feet of wastes. Because it is impractical
to locate and control all potential hot spots, an overall site,
9 round water remedy i s ~qui red.
The ground water extraction system is the only effective means
of preventing contaninated ground water from entering Coon
C~ek. The use of a drain system is not as effective as
extraction wells (particularly for potential NAPL) , more
difficult and costly to install, and more prone to
deterioration and failure than extraction wells. Wells can be
installed quickly and easily, have a proven ~liabi1ity, are
easily repai red or replaced if they do fail, can be ~asily
adj usted in te nn s of pe rfo nnance, and do not pose the ri sk of
encountering 'wastes that exists with trenching a drain system.
-------
VI I.
28
Not only will the ground water extraction system prevent
conta11inated ground water from entering Coon Creek, it will
also increase the difference of hydraulic potential between the
Lower Sand aquifer and Upper Sand aquifer and enhance the
upward gradient, further minimizing the potential for
contami nants to mig rate downwa rd.
Excavation of the Pit has already been discussed. Excavation
of the entire landfill (over 2.5 m,illion cubic yards of wastes)
was viewed as impracticable for lack of disposal options,
extremely costly ($48 million for excavation alone), and
extremely hazardous due to scattered presence of the
equivalence of 60,000 to 100,000 barrels of hazardous wastes
plus unknown quantities of other special wastes or infectious
wastes.
Recommended Alternative
A.
Desc ri pt i on
In order to control and prevent all existing releases from the
Site (Coon Creek discharge, leachate seeps, exposed wastes) and
potential future releases (ground water contaminant migration,
NAPL generation/migration, gas migration), a number of
different remedial alternatives are necessary. The
alternatives include ground water extraction from the Upper
Sand for the enti re Site, ai r stripping/carbon treatment of- the
contaninated ground water and likely discharge under an NPDES
permit, slurry wall around the Pit with its own g'round water
extraction system and NAPL monitoring system, and a cap over
the entire Site incorporating the existing lime sludge covering
the Site and meeting RCRA requirements, and long-term
monitoring of the Upper Sand and Lower Sand aquifers.
The ground water extraction system will consist of six
eight-inch wells, screened throughout the entire saturated
thickness of the Upper Sand, pumping approximate1y 10 gallons
per minute continuously, and located between the landfill and
Coon Creek (see Attachment 18). The ext ract i on system wi 11
effectively intercept all contaninated ground water migrating
from the Site in the Upper Sand aquifer and currently entering
Coon Creek. The ground water removed by the system would be
treated, using air stripping or activated carbon or both
depending upon the actual hydraulic and chemical loadings and
NPDES 1 imitations (other pret reatment may be necessary). The
preferred discharge would be to Coon Creek meeting NPDES'
permit requirements. Final decisions on the treatment and
disposal options must await detailed design, pilot testing,
and permit requirements. The extraction system will be a~ti've
indefinitely, and will g~at1y reduce, if not eliminate, any
loadings to Coon Creek and prevent contamination of those
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29
private wells north of Coon Creek. Nonnal1y. ground water
remedial systems are active until all ground water that is
moving beyond a Site boundary. at the very least. meets
drinking water standards. The ground water in the Upper Sand
is so severely contaminated and the releases will be ongoing
from scattered sources in the Site for an indefinite period.
precluding any chance of shutting down the system within a
projected time frame.
The Pit is the current major source of contaminant loading to
the Upper Sand aquifer and to Coon Creek. "The Pit a1 so has the
highest potential for NAPL generation. although no NAPL has
been clearly detected to date. In order to provide confinE!TIent
of any potential NAPL that might be released and maximize
removal of heavily-contaminated ground water. a slurry wall
will be installed completely around the Pit (Attachment 19) and
keyed into the existing red-brown till. The slurry wall will
be a soi1-bentenite mixture. at least 2 feet thick. having a
conductivity less tha~ 1x10-7 em/sec. The slurry wall is
designed to trap releases from the Pit for recovery via the
extraction well. manhole pumpout. and NAPL recovery wells. An
a-inch extraction well will be installed on the upgradient end
of the area enclosed by the slurry wall. will pump an estimated
90 gallons/day to maintain a lower piezometric level within the
slurry wall and an inward gradient across the slurry wall. .
Maintaining" the inward gradient will minimize the migration of
dissolved contaminants across the sl urry wall. Extracted
groundwater will be treated with the rest of the boundary
groundwater ext ract fon system.
The extraction well will be screened about 10-15 feet below the
water table. The existing manhole is completed to the bottom
of the Pit. Any liquids detected in the manhole will be pumped
out to minimize liquid releases from the Pit. NAPL monitoring
wells (4 well nests of paired wells) will be located outside
the Pit but within the slurry wall. The wells will be equiped
with sumps for NAPL detection and recovery. One well of each
pair will be completed at the top of the gray till and the
other well at the top of the red till. Any NAPL will be
recovered using these wells (see Attachment 20).
The cap over the entire site will consist of lime sludge that
largely covers the 73-acre site already. The lime sludge has a
hydraulic conductivity on the order of 10-5 to 10-6 on/sec.
The intent is to meet RCRA perfonnance standards. The 1 ime
sludge will be graded. stabilized. and compacted to achieve a
thickness of at least 3 feet. overlain by a 12 inch sand
drainage layer (hydraulic conductivity of greater than 10-3
cm/sec.). a geotextile filter fabric. 30 inches of fill. and 6
inches of topsoil with a grass vegetation cover. The su rface
slope"will be at least 3.5 percent. Altogether. 48.i.nches of
fill will cover the lime sludge zone. The lime sludge is
. .'" ......' '-r-''''',''' - .' ','" ~.~ - ~..'.
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-------
30
self-healing when it does not become dessicated; which is the
condition currently existing f.n -portions of the Site. The 48
inches of cover over the lime sludge will maintain adequate
moisture to maintain the lime sludge (just like a clay layer),
will prevent erosion of the fine grain lime sludge, and will
provide protection from frost heaving. The Remedial Design
will require further permeability testing, and adjustments to
surface slope, slope of drainage layer, grain size of fill, and
thickness of 1 ime sl udge in order to meet the RCRA performance
standards. Institutional control s' (deed re~trictions) will be
required to prevent installation of drinking water wells or
other action which could jeopardize the integrity of the cap.
Gas generation and migration (both for methane and for specific
volatile organics) has been docllT1ented, particularly west of
the landfill. Gas vents will be installed below the lime
sludge layer through to the surface. The gas vents will be
fitted with granular activated carbon filters to remove organic
contaminants (see Attachment 21).
In order to monitor the effectiveness of the response actions
and to ensure contaminants do not migrate into Coon Creek,
beyond Coon Creek in the Upper Sand aquifer, into the Lower
Sand and gas does not migrate in the unsaturated zone, an
extensive array of gas probes, ground water monitoring wells in
the Lower Sand aquifer and Upper Sand aquifer, NAPL monitoring
wells in the Upper Sand aquifer, the manhole in the Pit, and
sampling points in Coon Creek will be monitored. Any Coon
Creek discharges would be monitored as part of NPDES permit
requirements. Monitoring stations will be located on all sides
of and within the landfill and will include approximately 28
ground water monitoring wells, 10 NAPL monitoring wells, 3
surface water statiollS, 10 gas probes, the manhole in the Pit,
and selected, but as yet, undetennined number of private wells
(see Attachment 21). The monitoring system will assess the
effectiveness of the response actions al ready discussed and
will monitor all routes of current releases (Pit release
towards Coon Creek and potential releases of NAPL).
In order to enhance the monitoring network for NAPL migration
beyond the Site) to deal with the concern of multiple,
unlocated sources - "hot spots"), geophysical surveys will be
conducted along the perimeter of the landfill (SOO-foot radius
about the landfill) in order to identify low areas in the till
for placement of NAPL monitoring wells.
A related response action involves filling wetland areas
between the landfill and Coon Creek because they do receive
seepage intermittently from the Site. In order to discourage
migrating water fowl and other wildlife from inhabiting this
area, the wetlands will be filled i~ accordance with applkable
U.S. Army Corps of Engineering (COE) and U.S. Fish and Wi}dl ife
. , ,...- " ." ~
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.."~ . -." ~ . - :. ..t '.1. .
-------
31
Service (FWL) requirements, including mitigation. The actual
location(s) of any new wetlands must be negotiated between the
City of , ,Andover, Anoka County, the Minnesota Department of
Natural Resources, MPCA, FWL, COE and U.S. EPA.
B.
Costs
The costs of the recommended alternatives for response actions
are broken d.own into capital costs (generally construction or
requisition costs), operation and maintenance costs, and a
total present worth cost (10 percent discount rate 'and 30 year
1 He) .
The costs are delineated for each component of the response action
as follows:
P resent Worth
Capital Costs 0 & M Total Present Worth
Capping of Site $8,196,500 $235,673 $8,432,173
Ground Water
Extraction
Construction 812,000 41,478 853,478
Treatment
Ca rbon Treatment 91,000 470,138 561,138
Ai r Stripping 84,000 44, 306 128,306
D i s po s a 1
Coon Creek NPDES 28,700 381,789 410,489
Sl urry Wall With
Extraction Well 302,723 86,308 389,031
Site Monitoring 70,000 647,529 717 ,529
F i 11 i ng of Wetland 3,837 -0- 3,837
Total 9,504,796 1,862,915 11 ,367 ,675
(for carbon treatment
~nd Coon Creek disposal),
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32
VIr.
Applicable or Relevant and Appropriate Requirements
A.
General Discussion
Section 121(d) of SARA requires that remedial actions cOO1ply
with legally applicable or relevant and appropriate
requirements (ARARs) of Federal environmental laws and more
stringent, promulaged State laws.
. .
"Applicable" requirements are cleanup standards, standards
of control and other substantive environmental protection
requi renents, criteria or 1 imitations promulgated under 'Federal
or State 1 aw that spec ificall y add ress a haza rdous substance,
pollutant con tan in ant, remedial action, location or other
ci rcumstance at a site. A requi rement is "appl icable" if the
remedial action or circllT1stances at the site satisfy all the
juriSdictional prerequisites of the requiremen~. "Revelant and
appropriate" requirements are cleanup standards, standards of
control and other envi ronmental protection requi rements,
criteria or limitations promulgated under Federal or State law
that, while not "applicable" to the remedial action or
circumstances at the site, address problems or situations
sufficiently similar to those encountered at the site that
their use is well suited to the renedial action at the site.
Non-promulg'ated advisories or guidance documents issued by
Federal or State governments do not have the status of
potential ARARs; however, where ARARs do not exist, or .for some
reason may not be sufficiently protective', non-promulgated
advisories or guidance documents may be considered in
detennining the necessary level of cleanup for protection of
human health and the environment. See Interim Guidance on
Compliance with Applicable or Relevant and Appropriate
Requirements dated July 9, 1987. State of Minnesota
Recommended Allowable Limits (RALs) fall into this category.
This section identifies the requirements ~f environmental laws,
regulations and polices that are applicable or relevant and
appropriate standards for the recommended altemative for
remediating the site.
Ground- water protection standards have been establ ished under
RCRA, at 40 CFR Section 264.94. RCRA regulations apply to
facilities treating, storing and disposing of hazardous waste
as of November 19, 1980. Such facil ities were requi red to
apply for an operating permit by that date. Such facilities
are further required under Section 3004(u) of RCRA and 40 CFR
264.101 to institute "corrective action" as set forth in the
pe nnit, to renedy rel eases of haza rdous waste and const ituents
- from any "solid waste management unit" at the facility. The
ground water protection standards at 40 CFR 264.94 are to be
established in permits and apply to any solid waste management
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33
u'nits which received waste after July 26,1982. The ground
water standards serve both as a trigger for requi ring
corrective action to remedy a re1 ease from such a sol id waste
management unit, and as clean-up standards for the corrective
action. However, because no hazardous waste was placed in this
area after July 26, 1982, the ground water protection standards
of 40 CFR 264.94 are not "applicable" under RCRA to this solid
waste management unit. They may, nevertheless, be "relevant
and appropriate" as clean-up standards for this ground water
remed i a 1 act i on .
There are three types of" standards established under 40 CFR
264.94: Background levels, Listed Maximum Concentration Limits
and Altemate Concentration limits (ACLs). The regulations
specify that the standard for concentrations of hazardous
constituents in ground water in a facility pe nn it" must not
exceed the background level or a listed maximum concentration
limit or an ACL established by the Regional Administrator.
1.
Listed Maximum Contaminant Levels. To date, Maximum Concentration
Limits under RCRA have been established for fourteen chemicals.
These limits are based on and are identical to the Safe Drinking
Water Act MCLs for these chemicals. None of these listed chemicals
are contaminants in the ground water at the WDE site.
2.
" "
~ro'und Levels. The background level is that level of a
chemical in the ground water in an area not impacted by
contaninants in the ground water at the WDE site.
3.
ACLs. u.S. EPA may establish ACLs in lieu of background levels or
listed maximum concentration limits of the ACL "will not pose a
substantial present or potential hazard to hlJ11an health or the
environment as long as the [ACL] is not exceeded.1I 40 CFR
264.94(b).
Standards for specific contaminants have been promulgated under
the Safe Drinking Water Act (SDWA) to protect publ ic drinking
water systems. Standards set under the SDWA are usually
relevant and appropriate when groundwater is being cleaned up
at Superfund sites. Since this remedy creates an hydraulic
barrier to prevent movement of contaninated groundwater to off-
site areas, the remedy would comply with the SDWA and RCRA
correct fve act 10n requi renents. Under RCRA, the poi nt of
compliance would be set at the landfill boundary (at
groundwater extraction system). The SDWA standards are not
ARARs for on-site areas in this case, since institutional
controls will prevent any potential use of the contaninated
groundwater.
" "The Federal Clean Water Act (CWA), 33 U.S.C. "1251, et. ~,
as amended., requi res U.S.EPA to establ ish water qualTty
criteria for bodies of water, based on effects of pollutants on
." . ~ '. ,: .:
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-------
34
human health and aquatic life. 33 U.S.C. 1314. Section 121
of CERCLA states that ~media1 actions shall attain these water
quality crite-ria where they are ~levant and appropriate under
the circumstances of the release, based on the usage or
potential usage of the water ~ceiving the release. By
e1 iminating contaminated groundwater discharges the selected
remedy will assure continued maintenance of these criteria in
Coon Creek and should ~su1t in attainment of these criteria in
the groundwater north of Coon C~ek (methylene chloride
presently exceeds criteria. The existing concentration of
c'Ontaninants in Coon Creek should be brought well below the
10-6 risk levels and other freshwater criteria established
under the CWA.
The Federal Clean Water Act limits construction activities in
floodplains and wetland through Section 404. The Army Corps of
of Engineers administers these ~quirements through permits.
Since the proposed response action will involve construction of
a cap in the floodplain and the filling of wetlands, compliance
with applicable permit ~quirements established by the CaE, FWL
and U.S. EPA, including mitigation, is appropriate.
The Federal Clean Water Act limits discharges to waterways.
Individual discharges are ~gulated through National Pollutant
Discharge El imination System (NPDES) permits. (40 CFR Part
122) the State administered water quality program is
substan,ti ally equivalent to the Federal NPDES requi rements.
The discharge limits established in the NPDES permit process
a~ designed to p~serve the present use designation of the
~ceiving waters and potential downstream uses. Coon Creek is
cur~ntly designated as a partial body contact, warm water
fi she ry. The NPDES ~g ul at ions a re an ARAR fo r effl uent from
Superfund site treatment plants which discharge offsite. Water
quality-based NPDES permit limits will be based in part on
stream criteria and may include more stringent limits or whole
effluent toxicity limits to protect against interactive effect
of toxicants. NPDES permit limitations will be required for
di scharges of treated groundwater to Coon Creek.
During the design phase of the pruject the potential for
discharge to the POTW will be examined further. In order to
discharge from a Superfund site to a POTW, certain factors must
be cons~dered which are identified in a policy memorandum dated
April 15, 1986, "Di scharge of Wastewater from CERCLA Sites into
POTWs" frum Henry L. Longest, Director, Office of Emergency and
Remedial Response, Rebecca Hanner, Director, Office of Water
Enforcement and Permits, and Gene Lucero, Director, Office of
Waste Prograns Enforcement, to Waste Management Division
Directors, Regions I-X. These factors are listed below.
- (1) Potential of, pollutants to cause pass through or interference,
including a health hazard to employees 'at the POTW.
..
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-------
35
(2) The ability of the POTW to ensu~ compliance with
applicabl e t ~atment standa rds and ~qui ~ents.
(3) The POTW' s ~cord of compl iance with the NPOES pennit and
pretreatment program requirements.
(4) The potential for volatilization of the wastewater and its
impact upon ai r qual ity. .
(5) The potential for ground water contamination from
transport of CERCLA wastewater to the POTW, and the need" for
ground water monitoring.
(6) The potential effect of the CERCLA wastewaters upon the
POTW's discharge "into ~ceiving waters.
B.
Site Oi scussion
The overall objective of any response actions a~ to
pennanently or significantly ~duce the vol ume, toxicity, or
mObility of the hazardous substances, pollutants, or
contaminants. However, dealing with sites on the scale of the
WOE Site (equivalent of 60,000 - 100,000 bar~ls of hazardous
wastes wit~in 2.5 million cubic yanjs of solid waste) is "
ext~mely difficult. particularly in ~gard to ~ducing the
volume and toxicity. Although excavation of the Pit may
potentially ~duce the volume and toxicity of hazanjous
substances, the Pit does ~present only an estimated 10 percent
of the hazardous substances disposed at the Site. The
renaining wastes a~ scatte~d throughout the landfill. The
natu~ of the Site is such that ~sponse actions must deal with
the Site in its entirety and. therefore, focus on controlling
the mobility of the hazardous substances. The lime sludge cap
is designed to isolate the wastes from di~ct contact, to limit
the mobilization of liquids and generation of leachates. and
control gas migration. It should meet RCRA perfonnance
~quirements and will incorporate the existing lime sludge
cover at the Site. The cap does sat i sfy MPCA ~qui rernents fo r
general landfill caps and Anoka County ~qui rements for cap
closures. This cap will also need to satisfy the State closu~
~qui rements for the SW-28 pennit issued in 1971.
If the lime sludge cap we~ not utlized as a cap. the
excavation and disposal of the lime sludge will be a
significant problem in and of itself, in addition to concerns
about exposed wastes and physical hazards. "
The ground water extraction system will requi ~ carbon t~at-
ment and/or air stripping, with a diScharge of the t~ated
effl uent to Coon C ~ek. The ground wate r - ext ract i on com p6nent
is the primary mechanism for eliminating the mObility of
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-------
36
hazanjous substances f"nJm the Site. These hazanjous substances
are currently impacting Coon Creek and some gnJund water beyond
the creek. The ground water extraction system will prevent
contaminants from migrating beyond the northern fringe of the
Site, eliminated the contamination in the Creek and beyond the
Site. The existing concentrations of contaminants should be
brought well below the 10-6 risk Water Quality Criteria for
contaminants in Coon Creek and below the Maximum Contaminant
Levels, Water Quality Criteria, and Minnesota Recommended
Allowable Limits for gnJund water 'north of the creek.
The air stripper will have to have carbon treatment for the
exhaust because some of the volatile organics are considered
! carcinogenic. Additional treatment trains may need to be
evaluated and implemented to meet the objectives of the NPOES
pennit requi rements.
'-"
Spent carbon fnJm the air stripper as well as from the carbon treatment
of g round water wi 11 be handl ed as a hazanjous waste under RCRA
reg u 1 at ion s .
The discharge from the gnJund water extraction system will likely go to
Coon Creek under an NPDES pennit requirements established by the MPCA
and with the approval of the Coon Creek Watershed District.
Appropriations approval from the Minnesota Department of Natural
Resources f1)r the extraction of contaminants will be required. The
wells must comply with the Minnesota Water Well Construction Code.
. In the event that an NPDES pennit requi rements cannot be achieved, the
option of disposal to the sanitary sewer must be seriously considered.
However, the City of Andover has strongly objected to this option and
the MWCC has expressed reservations about allowing long-tenn discharges
to the sanitary sewer system because of the relatively dilute
wastewater (relatively low solids~ and the presence of a wide variety
of organics. This Record of Decision will be modified in the event
that discharge to the sanitary sewer is reconmended as a result of
future remedial design activities.
The slurry wall with ground water extraction and NAPL monitoring
and extraction for the Pit do not necessarily have any particular rules
or regulations that directly apply to the alternative other than those
already applicable to the overall ground water extraction system.
The filling of the wetlands (about 2 acres in total) south of
i Coon Creek will be conducted considering applicable U.S. Anny Corps of
Engineers requi rements and input from the Department of Natural
Resources. Mitigation, such as replacement, can. be required by FWS,
according to CWA, section 404, pnJvisions.
. The construction of the new monitoring well s and extraction well s
must be in accordance to the Minnesota Water Well Construction
Code.
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~7
IX.
Enforcement Status
The WOE Site is located within the city limits of Andover (formerly
Grow Township), Anoka County. Prior to 1971, the WOE Site was operated
as a solid waste dump for at least nine years. The dump was
established by Leonard E. Johnson and was licensed by Grow Township.
The dump was purchased by WOE, Inc. in 1968. A permit to operate
as a sanitary landfill was granted by the Grow Township Board .
effective mid-year, 1968. In 1970, WOE, Inc. submitted a permit
application for the MPCA to operate a solid waste disposal system.
Included in this application was a proposal to dispose of
hazardous substances in a specially constructed trench in the landfill
(generally referred to as the "WOE Pit"). On March 30,1971, the MPCA
issued a permit (SW-28) to WOE, Inc. to operate the WOE Site as a solid
waste disposal system including construction and operation of the WOE
Pit. Approval was al so given by Anoka County and the Metropol itan
Counc i 1 .
Construction of the WOE Pit was completed in 1972. The MPCA ordered
the WOE Pit closed effective February 1, 1974 due to changes in
regulations and because the MPCA determined that a high potential for
ground water pollution existed at the WOE Site. That detennination was
based on the fact that: WOE Inc. submitted inadequate hazardous waste
disposal reports, WOE, Inc. did not submit required monitoring results,
and investigation indicated that WOE, Inc~ did not follow the plans
approved by the MPCA for the WOE ~it disposal operations.
WOE, Inc. sent a notification of a Hazardous Waste Site regarding the
WOE Site to U.S. EPA in June, 1981 in fulfillment of CERCLA 103(c).
Pursuant to section 105(b) of CERCLA, the WOE Site was listed on the
National Priorities List by publication in the Federal Register on
September 8, 1983, 48 Fed. Reg. 40658-40682 (1983).
The Minnesota Department of Health in January, 1983 issued a drinking
water well advisory in portions of the city of Andover due, in part, to
hazardous substances disposal at the WOE Site. The well advisory was
dropped following the completion of the Remedial Investigation for the
Site in- October, 1985.
In Man:h, 1984 the MPCA and U.S. EPA entered into a.Consent Order with
9 companies. Three more companies jOined the group and executed the
Consent Order in April, 1984. The twelve companies (known as the.
IIRespondents" in the Consent Order) are Economics Laboratory, Inc.,
Ford Motor Company, Honeywell, Midland Cooperatives, Inc., Minco
products, Onan Corporation, Sperry Corporation (Unisys), Thermo King
Corporation, Warden Oil, Control Data Corporation, Com~lius Company,
and FMC CO rpo rat ion. .
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38
The Respondents agreed in the Consent Order to accompl ish the following
tasks:
1. Design, initiate and complete the landfill and pit Remedial
Investigation/Feasibility Study (RI/FS);
2. Establ ish a trust fund to pay for the RI/FS work;
3. Establish a $1 million trust fund in the event the Respondents
do not implement the remedial actions as selected by the MPCA and
U.S. EPA;
4. Design the selected response action for the WOE site designated in
the U.S. EPA Reconj of Decision; and
5. Enter into good faith negotiations leading to an agreement to
address remedial and removal actions at the WOE Site.
Under the Consent Onjer the MPCA and U.S.EPA agreed to:
1. Identify additional potential responsible persons who are not
currently parties to the Consent Onjer;
2. Issue Requests for Response Actions (RFRA's) to additional
responsible persons; and
3. Issue Determinations of Inadequate Response (OIR's) to each of
the responsible persons who have failed to respond or who respond
inadequately.
In partial fulfillment of obligations under the Consent Onjer, the MPCA
issued a RFRA to seven responsible Persons in July, 1984.. These seven
included Melron, Inc. (property owner), Ronald Roth (part owner of
Melron, Inc. and operator of the WOE Site), Waste Control, Inc.
(WCI-transporter), Art Willman & Sons, Inc. (transporter), Industrial
Steel Container (owned or possessed hazanjous substances and arranged
for thei r disposal), and Whittaker Corporation (owned or possessed
hazanjous substances and arranged for thei r disposal). Each of the
parties named as responsible persons in the July, 1984 RFRA failed to
take the requested actions and were subsequently issued a DIR in
October, 1984.
In April, 1987, the MPCA again issued a RFRA to seven additional
responsible persons. These seven included American Can COO1pany, G & K
Services, Inc., Gillette Company, H.B. Fuller Company, Minneapolis
Electric Steel Castings Division-Evans .Product Company, Soo Line
Rail road Comp~ny and Union Brass and Metal Manufacturing Company.
These parties ~ere issued a RFRA because ~hey owned or possessed
hazanjous substances and arranged for the disposal or transport for
disposal of those substances at the WOE Site. Each of these companie~
have agreed, in writing, to take the requested actions by notifying the
MPCA that they intend to negotiate in good faith reganjing
participation in implementation of remedial action at the WOE Site.
In September, 1987 the MPCA issued a RFRA to twelve additional
responsible persons. These twelve included American Hoist and Derric.k,
Brandtjen and Kluge, Dworsky Barrel, Federal Cartridge Corporation
(Federal-Hoffman, Inc.), Foley Manufacturing Company (Foley-Bel saw
-------
- ". . ,. '."
39
Company). Frost Paint and Oil Corporation, Glidden Paint, Mogul
Corporation. Northwest Airlines, Pako Corporation, Saxon Industries,
Inc. (Paper Corporation of America) and Whirlpool Corporation.
The MPCA and U.S. EPA shall intend to begin negotiations to enter into
a Consent Decree with the responsible parties. The major task to be
accomplished in the Consent Decree is the implementation of the
r~edial actions.
x.
Operation and Maintenance:
There are many operations in the proposed remedy which must be
maintained. These include the following:
A. Operation, maintenance, and monitoring of ground pump-out
we 11 s :
1.
in a line along the northern perimeter of the site
to contai n and remove contan i nated groundwater, and which
will also be beneficial in maintaining the upward gradient
between the Upper and Lower Sand aquifers at the Site, and
2.
within the slurry wall around the Pit to maintain an
inward ,gradient and to remove contanination if necessary.
B. Operation, maintenance, and monitoring of the extracted
ground water treatment systen, which is expected to be carbon
ab so rpt i on . .
C. Monitoring of the discharge of the collected groundwater,
expected to be to Coon Creek in accordance with an NPDES permit.
D. Operation, maintenance, and monitoring of the landfill
gas vents to avoid gas accumulation under the landfill cap.
E. Maintenance of the landfill cap to maintain a cover over
waste materials, to eliminate seeps, to reduce infiltration through
waste material s and to prevent use of the underlying groundwater.
F. Monitoring of ground water. surface water, potential"
NAPL ~tes. and gas within the landfill to assure the
effectiveness of the response actions.
G. Maintaining institutional controls prohibiting wells in the
Upper and Lower Sand aquifers near the Site to avoid use of
contaninated water and to maintain a vetical gradient across
,the red/brown till is being recofTlnended as a precautionary
measure. These actions can be implenented by the State through
the Minnesota Department of Health. through thei I' approval.
-r"ights over installation of new drinking-water wells.
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-------
40
XI. Community Relations History:
Since 1983, the MPCA and U.S. EPA have been involved in numerous
community relations activities associated with the WDE, Inc. Site.
The major community relation relations activities include the
following:
April 1983
May 1983
Oct. 27,1983
November 1983
Nov. 10, 1983
Mar. 23, 1984
June 18, 1984
June 1984
June 25, 1984
Sept. 27, 1985
Oct. 9, 1985
Oct. 25, 1985
F eb. 7, 1986
March 10, 1986 .
The MPCA conducted community interviews with local officials
and interested residents.
The MPCA prepared a Community Relations Plan for the
anticipated fund-financed Remedial Investigation/Feasibil ity
Study.
The MPCA issued a news release announcing a public meeting
and the beginning of a Superfund project.
The MPCA prepared a fact sheet providing background on the
Site.
The U.S. EPA and MPCA participated in a public meeting at the
Andover City Hall and discussed the Superfund proJect.
The U.S. EPA issued a news release announcing that agreement
had been reached on the tenns of a Consent Order.
The MPCA issued a news release announcing a public meeting
and the beginning of a responsible party investigation.
The MPCA prepared a revised fact sheet providing background
and history of the Site.
The MPCA sponsored a public meeting at the Andover City Hall
to discuss the Consent Order and investigation plans.
The MPCA issued a news release announcing a public meeting
and completion of a draft Renedial Investigation report.
The MPCA sponsored a public meeting on the Remedial
Investigation report.
The MPCA issued a news release regarding the revised Remedial
Investigation report.
The MPCA issued a news release regarding the completion of a
draft Alternative Reports.
Meeting on Alternatives Report held with Anoka County
Commissioners and Andover City Council.
-------
May 1, 1986
May 1986
May 14, 1986
June 16, 1986
October 15, 1986
Sept. 3, 1987
. Sept. 8, 1987
Sept. 14,1987
41
The MPCA issued. a news release announcing a publ ic meeting to
provide a project update.
The MPCA prepared an updated fact sheet which included
investigation results and a list of alternatives being
considered. The fact sheet (and a public meeting
announcenent) was del ivered door-to-door by members of the
community.
The MPCA sponsored a public meeting at the Andover City Hall.
as a project update.
The MPCA provided an update to the staff and menbers of the
Coon Creek Wate rshed Di st ri ct.
Meeting held with officials of the City of Andover, Anoka
County, MPCA, and representatives of the. SW-28 Group to
discuss the Detailed Analysis Report.
The MPCA issued a news release announcing the recommended
alternatives and a public meeting.
The U.S. EPA sponsored an ad in the Minneapolis daily paper
which included the meeting date and the recommended
alternatives.
The U.S. EPA and MPCA sponsored a public meeting at the
Andover City Ha1l to discuss the recommended alternatives.
Throughout the project, reports and fact sheets were made available at
the Andover City Hall. During the latter half of 1985, when
investigation results were coming in, a number of meetings were held
with city and county officials to respond to their questions on the
fi nd i ng s.
Throughout the course of the RI/FS, the MPCA, Anoka County, and City of
Andover officials have discussed on an individual basis with many
private citizens. Approximately 75 private citizens were on a regular
mail ing 1 i st to receive all fact sheets and news rel eases and all
aspects of the RI/FS and related activities.
In addition, a number of news publ ications have reported major
findings, deYelo~ents, or decisions throughout the RIfFS process.
City of Andover and Anoka County officials have been invited to and
actively participate in djscussions and meetings with the SW-28 Group
throughout the RI/FS process. They have also commented extensively ~n
the submittals related to the RIfFS process.
These actions will be implemented in accordance with applicable laws
and regulations.
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PROPERTY 3OUNOAR"I'
OBSERVATION WEL,1. OR
BOREHOLE:
GAS PROBE wELL.
CHLORIDE CONCENTRATIONS
(PPM) MAY /98S ...
L/WIT OF R(F'US£ OISPOSAL
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CHLORIDE CONCENTRATIONS
UPPER SAND AQUIFER
WOE, Andover I Minnesota
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I ATTACHMENT 9
I WASTE DISPOSAL ENGINEERING
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ATTAChMENT 10
WASTE DISPOSAL ENGINEERING
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COO CONCENTRATIONS
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WASTE DISPOSAL ENGINEERiNG
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1.IWIT OF ReFUSE DISPOSAL
OBSt~VATIOH W(LI./BC~E~OLE
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SOuRCE: AHOKA COUNTY
I
WDE
RI/FS
EVAlUATION
E.A. HCKOK & ASSOOATES
HYDAOlOGSTs-~
MNEAPOlIS -MHESOTA
APRIL,. 1984
PROPERTY O'NNERSHIP MAP
5
-------
"J
Rele..e/Source
Meehani.
OU.t/.olatll-
hatton
Sol1 ,a.
Reaction between
inCOllpattble
waste.
Pit leua,e
~
Landfill leata,e
'o..ible future
leaka,e frOG upper
.and aquifer
D18chUge frc.
upper .and aquifer
~
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ATTACIIMENT 15~~~:
WASTE .DISPOSAL ENGINE:>'
DI'nLOPMIN'I' or POrIMl'IAL DPOSURB .ATllWAT8 - WOK 8MITAJrI LAI8DPILL
(See Work8heet 4.2 of the Superfund Public Health Evaluation Manual)
Relea.e/
Tran.port MeeUa
Air
Air
Air
Upper Sand Aquifer
Upper Sand Aquifer
Lover Sand Aqoifer .
Surface Water
11__11
'otenttal
Expo.ure Route
- inh81a'tton
- demal
- inhalatton
dennal
- inhalation
- inge.tton of
drinking water
ingesUon of
drinking vater
- ingestion of
drinking vater
- inge8tion of
vater and fhh
- dermal contact
indirect exposure
through ingestion
or exposed crops or
a!,imal s
.\~
-
Potential
Expo.ure .oint
- on-dte
- within 500 feet
of l1.it of'refu.e
- residential within
1 mile of the .Ite
- on-.lte
- on-aite
- reddenthl
within 0.5 .Ilea
vest and south-
vest of 81te
- Coon Creek
Mississippi River
-
-
..
..
NUlllber of
People
Potent1~llr
Affected'
<50
<50
1,000
0'
o
1,800
<100
<10,000
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Mechanism
Tracking of lime
8ludge
NAPL
Exposed waite/
leachate and
IlJlle sludge
TABLE).4
DEVELOPMENT OF POTENTIAL EXPOSURE PATH~YS - WOE SANITARY LANDFILL
(See Worksheet 4.2 of the Superfund Public Health Evaluation Manual)
Release/
Transport Hedium
Sol1
Upper Sand Aquifer
a) on top of water
surface (floaters)
b) on top of till
, surface (sinkers)
none
Potential
Exposure Route
- inhalation and/or
ingestion of
lime sludCje
- miCjration on top
of vater surface
gravity flow on
top of till surface
direct dermal
contact
- inhalation
- inCjestion
Potential
Exposure Point
- local residents
who participate
in recreational
activities on-site
- Coon Creek
Coon Creek
'Lower Sand Aquifer
- individuals on site
for recreation
Nunlber of
People
Potentially
Atrected
<50
o
.
<50
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ATTACi-iHE::T 17
DISPOShi.. ENGH,EERING
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Responsiveness Summary for the Waste Disposal
Engineering Site in Andover. Minnesota.
1. Introduction
The United States Environmental Protection Agency (U.S. EPA) obtained
information on the types and extent of contamination. evaluated remedial
measures. and recommended remedial actions for ground and surface water
contamination. gas emissions, and direct contact concerns resulting from the
Waste Disposal Engineering Site in Andover, Minnesota. As part of this
process. U.S. EPA submitted its recommended'alternative for public comment for
a twenty-one day period. Public participation in Superfund projects is
required under the Comprehensive Environmental Response, Compensation and
liability Act of 1980 (CERClA), as amended by the Superfund Amendments and
Reauthorization Act of 1986 (SARA), and the National Oil and Hazardous
. Substances Contingency Plan (NCP). A public meeting to discuss alternatives,
explain the proposed remedy and solicit public comment was held at the Andover
City Hall on September 14, 1987. Comments received by the public are
considered in the selection of the remedial action for the Site. This
document summarizes the comments received and states U.S. EPA's responses to
those comments.
The responsiveness summary has four section:
a.
Introduction.
This section briefly explains this documen~.
b.
Overview. This document briefly presents a history of community
relations at the Site.
c.
Background on Community Involvement. This section briefly
presents a history of community relations.
Summary of Public Comments Received During the Public Comment
Period and U.S. EPA's Responses.
d.
2.
Overview
During the public comment period, the U.S. EPA and the Minnesota Pollution
Control Agency (MPCA) held a public meeting to discuss the Site. The U.S. EPA
and MPCA recommended a solution, similar to the potentially responsible
parties recommendation, through some additions to the feasibility study
document entitled the IIDetailed Analysis Report". The recorrmended solution
includes long-term (indefinite) ground water extraction through pump-out wells
in the Upper Sand aquifer between the landfill and Coon Creek to keep
contaminants from migrating off-site; a Resource Conservation and Recovery Act
(RCRA)-compliant lime sludge cap to cover the landfill, safely vent and treat
landfill gases, and reduce infiltration through the waste; a slurry wall
around the Pit to contain the concentration of wastes within the Pit; a ground
water extraction well within the slurry wall to maintain an inward hydraulic
gradient such that if the wall leaxs the water will flow into the walled area
and be extracted'by the pump-out well ,thereby containing contaminants; filling
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" in a wetland Jrea i~ the ~ortheast corner of the Site and replacing it nearby;
"treatment of extracted ground water by carbon adsorption; discharge of
extracted ground water to Coon Creek; and long-term monitoring of the remedial
activities (the cap, the extraction system, etc.), the contamination (ground
water, gas, etc.), and the- receptors (Coon Creek, residents' wells, the Lower
Sand aquifer, etc.). In addition, the recommendation included consideration
of institutional controls to keep people from placing new wells in the Upper
Sand aquifer just north of Coon Creek where contamination has been found and
in the Lower Sand aquifer around the Site in order to maintain the existing
upward water pressure between the Upper and Lower Sand aquifers. The addition
of municipal water to the area by the City of Andover is expected to reduce
the likelihood of new wells. The Upper Sand aquifer just north of the creek
is near a sanitary sewer line, is in the floodplain, will be isolated from the
contamination by the extraction well system, and will, in the long-term,
cleanse itself. These conditions act to reduce the probablity of new wells
being placed in the area. The Lower Sand aquifer around the Site is expected
to continue to be stressed by the construction of new private drinking water
wells which would increase the likelihood of a downward water pressure between
the Upper and Lower Sand aquifers. However, the municipal water will reduce
the stress on the aquifers that would have been expected due to the
construction of new wells and the monitoring will give warning if action is
needed to maintain an upward gradient. Consequently, although they are
considered prudent, the need for institutional controls beyond the Site area
(includes all land just south of Coon Creek) is not critic~l at this time.
Comments were received at the public meeting on the Waste Disposal
Engineering Site held in the Andover City Hall in September of 1987, and
by the potentially responsible parties (PRPs) during the publi~ comment
peri od.
3.
Background on Community Involvement
Since 1983 the MPCA and the U.S. EPA have been involved in numerous
community relations activities associated with the Waste Disposal Engineering
Site. Numerous fact sheets and news releases were issued throughout the
remedial investigation/feasibility study (RI/FS) to, among others, approxi-
mately 75 private citizens on the regular mailing list. Public meetings were
held at the beginning of the project, on the remedial investigation report,
after the alternatives report, and on the proposed remedy, and City of Andover
and Anoka County officials were invited to and participated in discussions
with, and commented extensively on submittals of the SW-28 Group (PRPs who
came forward to conduct the RIfFS) throughout the RIfFS process.
On September 3, 1987, the MPCA issued a news release on the proposed
remedy and the public meeting. On September 8, 1987, U.S. EPA sponsored
an ad in the MinneapoliS daily paper announcing the beginning of the public
comment period, the availability of the RI/FS, as modified, for public
inspection, the meeting date, and the proposed remedy. On September 14, 1987,
a public meeting was held in the Andover City Hall and public comments were
rece"ived. On September 29, 1987, the public comment period was closed. .
'.---
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3
During the conment period, conment was rec~iv.ed from the.SW-28 Group.
other public comments were received.
No
4.
Summary of Public Comments Received During the Public Comment ~eriod
The following are comments from the September 14, 1987 public meeting in the
Andover City Hall.
!. Comment: Why does it take so long for, anything to happen? The Site has
been known since 1968 and twenty years later we are still talking about it.
'I
Response: Although the Site was purchased by Waste Disposal Engineering,
Inc., in 1968, it was a permitted and operating landfill in the 1970's and
early 1980's. The framework for the U.S. EPA to address this Site began with
the passage of the Comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA) on December 11, 1980. Once the authority was
established by CERCLA, a process had to be established to find potential sites
and decide which ones should be addressed first with limited Federal
resources. Using this process the Waste Disposal Engineering Site was
announc~d as a potential Superfund site on July 23, 1982. Initially,
background information on the Site and potentially responsible parties (PRPs),
those persons that may be liable for problens at the Site, was canpiled.
Using the background information, statements of work that generally describe
the kind of studies that are necessary to characterize the Site were prepared,
and the PRPs were not ifi ed that they were PRPs, that the U.S. EPA intended to
do work at the Site', and that they might be liable for the U.S. EPA costs of
that work. In March of 1984, a written agreement, called a Consent Order, was
signed in which the PRPs conmitted to conduct a remedial investigation/,
feasibility study (RIfFS) based on statements of work contained in the Consent
Order. The RIfFS is to characterize the Site and analyze various solutions
such that the cost-effective solution that protects the public health, welfare
and the environment can be chosen. The information obtained during and
presented in the RIfFS must be obtained in a manner that will stand up in a
court of law. Once the U.S. EPA, in consultation with the MPCA, designates
its chosen solution in a Record of Decision (ROD), the PRPs will design the
solution as part of the Consent Order. Negotiations will then occur to
.determine if the PRPs will conduct the construction. If not, the U.S. EPA can
either conduct the action itself and sue for its costs later, or it can seek
to have the court require that the PRPs do the cleanup. If so, the MPCA,
U.S.EPA, and PRPs can sign a Consent Decree, an agreement lodged with a court,
to have the PRPs do the cleanup. In summary, much of the time the Site was in
operation it was not known as a problem to be.addressed by Superfund (i.e.,
1960's and 1970's). When the Site was recognized, it was put into the
Superfund remedial action process. The process is deliberate, but it does
move forward along established lines toward Site cleanup. Two problems which
have taken more time than originally expected were establishing analytical
procedures and finding a laboratory capable of conducting the work as
specified, and determining and incorporating the additional requirements of
the Superfund Amendments and Reauthorization Act uf 1986 (SARA). :
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b. COrTl11ent :
speclfied.
The levels of toxicity in the discharge water have not been
Response: The National Pollutant Discharge Elimination System (NPDES) permit
requlrements under the Federal Clean Water Act are an applicable or relevant
and appropriate requirement (ARAR) which will be addressed at this Site. The
permit requirements define the actual levels of contaminants that can be
discharged to the Creek, as well as the conditions under which discharges can
occur. Factors considered in making these requirements include the flow in
the creek, the dilution given to the dischaTge by the creek, and Water Quality
Criteria. In other words, the creek conditions at the Site are considered in
conjunction with the concentrations of the contaminants to determine the
appropriate discharge levels that will not adversely impact the creek and its
uses. Specific effluent limitations will be defined for the discharge
during the remedial design and as part of the NPDES process.
It should also be understood that the ground water
ultimately discharges to the creek. Therefore, by
ground water before it enters the creek, the total
enters the creek is reduced.
in the Upper Sand aquifer
removing and treating the
contaminant mass that
c. Comment: The standards change as more information becomes available and
there is no real assurance from the scientific community that the levels are
safe.
Res~onse: It is a fact that standards can change as new information becomes
aval1able. However, the standards are generally conservatively applied such
that factors of safety are built in to the process. Further, under the
Superfund Amendments and Reauthorization Act of 1986 (SARA), Section 121(c).
the U.S. EPA is required to reevalute a Site where contaminants are left on-
site no less often than every five years after initiation of the remedial
action to assure that human health and the environment are being protected by
the remedial action being implemented. The reevaluation will consider any new
potential health impacts which may have been identified due to scientific
advances.
d. Comment: Looking at a thirty-year plan for monjtoring wells, there are
concerns about well breakdowns, improper reading of the wells, contamination
of samples, and poor laboratory results.
Response: The monitoring wells are expected to be in operation indefinitely.
The thirty-year period is used for cost comparisons because after that period
of time the preSent worth value of the costs tend to be negligible. As part
of the operations and maintenance of the proposed remedial action, provisions
are made to assure that proper care is taken in the implementation of the
monitioring program. If the wells break down, they will be repaired or
replaced. There will be a specific plan for the methods to be used in
sampling and analysis of samples. There will also be checks built into the
procedures to assure adequate sampling and analysis is performed (blanks,
split samples, calibration checks, etc;). The Site will also undergo periodic
review by the U.S. EPA under SARA. '. . .
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5
e. Comment: A special assessment on a house was to support a holding pond to
keep water out of Coon Creek. Putttng more water into Coon Creek should be
avoided. . .
Response: Since the Upper Sand aquifer discharges into Coon Creek anyway, the
discharge of extracted ground water is not the same as discharging an
independent source of water into the creek. Furthermore, the analysis of
alternatives indicated that the creek discharge would be favorable compared to
the discharge which would involve .removing the water from the creek area,
discharge to the sanitary sewer and ultimately to the sewage treatment plant.
As discussed in the public meeting, discharge to the sanitary sewer would
reduce available sewer capacity, which would limit growth, which would reduce
the available tax base for the community. The proposed discharge is expected
to be limited such that adverse impacts to the creek resulting from such
discharges will be mitigated (It is one of the considerations of the NPOES
process) ..
f. Comment: The local community is paying for municipal water to protect
them and that investment is not being addressed by the people who created the
problem.
Response: The private drinking water wells in the area are not now being
adversely affected by the Site. With the implementation of the proposed
remedy, those wells are not expected to be impacted by the Site.
g. Comment: The.economic losses to the community are staggering already and
not a drop of wate~ has been purified.
Response: The. proposed remedy is designed to contain contamination from the
Slte an& to treat contaminant discharges before they are discharged into the
environment. Upon implementation of the proposed remedy, water is expected to
be treated.
h. Comment:
ha nued?
Can kids go in Coon Creek wading and swimming, and not be
Response: The Minnesota Department of Health and the public health evaluation
of current conditions in the Detailed Analysis Report indicate that the
existing health risks in Coon Creek are not such that those activities need to
be prohibited. The proposed remedy is primarily to assure that the potential
for a significant problem resulting from the volumes of wastes that went into
the landfill i5 never realized in the creek.
i .
Comment:
How far down from the Site was Coon Creek sampled?
Response: As part of the remedial investigation, Coon Creek sediments were
sampled up to three and a half miles downstream of the Site.
j. Comment: When discharging to Coon Creek will the quality of Coon Creek
water be better than with leachate discharging into it?
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6
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Response: Overall. since it is expected that the Upper Sand aquifer
discharges entirely into Coon Creek from the Site. the tontamjnant loadings to
Coon Creek will be reduced. the water quality improved. and the potential for
significant contaminant discharges into the creek from the Site through the
ground water eliminated by the proposed remedy.
k. ,Comment: Is C90n Creek going to be dealt with in terms of the volume of
the discharge into it?
Response: Yes. Based on discussions with the MPCA. it is not expected that
the'proposed discharge of around 60 gallons per minute will adversely impact
the creek. This will be considered furthe~ in terms of NPDES requirements.
The following are comments from the SW-28 Group (the PRPs who volunteered to
come forward and conduct the RIfFS and remedial design under a Consent Order
with the U.S. EPA and MPCA) as expressed in their September 10. 1987 letter.
1. Comment: For U.S. EPA to issue its Record of Decision (ROD) before the
end of 1tS fiscal year. September 30. 1987. would be inappropriate.
~~~~~n~~~. ~~~c:g;~:dP~~i~Ct~~~~~~e~~r~~~ ~~~ ~~~ ~~~1~~~iih;e~6~m~:~0;;'the
end of the fiscal year.
m. Comment: The SW-28 Group reserves the right to supplement the record
beyond the 21-day public comment period.
Response: Under 40 CFR Part 300.67(d) of the NCP. the feasibility study must
be prov1ded to the public for review and comment for a period of not less than
21 calendar days. This was done for the Waste Disposal Engineering Site in
that the public comment period was 21 days. Further. since the SW-28 Group
prepared the feasibility study and has discussed issues at the Site with the
U.S. EPA and the MPCA extensively throughout the previous months. it was not
considered appropriate to extend the public comment period for undefined
reasons for an indefinite length of time. . The public comment period closed on
September 29. 1987.
The following is a comment from the SW-28 Group as expressed in their
September 24. 1987 comment letter.
n. Comment: The additional six inches of drainage layer and six inches of
.fi11 requ1red by U.S. EPA and MPCA modifications to the Detailed Analysis
Report are not required to meet the technical performance standards of a
Resource Conservation and Recovery Act (RCRA) landfill closure cap.
Response: RCRA landfill closure (see 40 CFR Part 264). which is an ARAR.
requires five elements be addressed. They are: 1) provide long-term
minimization of migration of liquids through the closed landfill; 2) function
with minimum maintenance; 3) promote drainage and minimize erosion or
abrasion of the cover; 4) accommodate settling and subsidence so that the
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7
cover's integrity is maintained; and 5) have a permeability less than or
equal to the permeability of any bottom liner system or natural subsoils
present. Items 1),2), and 3) were of concern due to the original design of
the lime sludge cap. By allowing the open field frost penetration in the area
of four feet to penetrate a foot into the lime sludge, the impermeable layer,
the ability of the. cap structurally to continue to support the rest of the cap
(function with a minimum of maintenance) and to maintain long-term
minimization of liquids through the landfill is put in doubt because heaving
could both weaken and allow more infiltration through the lime sludge. This
is especially significant because the lime sludge is not being placed in six-
inch lifts as is normally expected to assure the integrity of the impermeable
layer and because the history of lime sludge as an adequate impermeable layer
is lacking. The surface layers of the lime sludge are structurally
significant and must be protected from frost penetration. The need to promote
adequate drainage requires that a one foot drainage layer be constructed. The
proposed six-inch layer is not considered adequate, considering construction
techniques, to drain and not be clogged. With these modifications and the
testing to be required during design of the cap, it is expected that the lime
sludge cap will be constructed to be generally consistent with RCRA
performance standards.
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1'ITLE/SUBJ ECT
I.
PASI
1.
P~elimina:y Assessme~t
and Site I~vestigation
(The:e a:e two site inspec-
tio~ repo~ts)
National P:io~ities
Checklist (NPL)
Quality Cor.t:ol Notes
E~fo~cernent Summary
and Status Report
Conditior.s a~d
Status Repo:t
Wo~ksheets
to g~ade the site
2.
3.
4.
5 .
6 .
II. PASI APPENDIX
1.
Bibliography for
Docume~t which ra~ks
the site.
(I~cludes refe:e~ce~)-
III.
WORKPLAN
1-
2.
Lar.df ill RI/FS
Lar.dfill ar.d Pit
Safety Pla~
Evaluatio~ Re~ort
Lar.dfill and Pit
RI/ F S
S~c:J:ity Pla~
Lar.df ill RI/FS
S~curity Pla~
Pit R!/FS
RI: Pit RI/FS
3.
4 .
5.
6 .
IV.
WORKPLAN CORRESPONDENCE
1.
Lette: to E.A. Hickok
from Mi~nesoat Pollution
Control Age~cy (MPCA)
requestir.g modific3tions
to the Evaluation Repo~t,
Landfill and Pit RI/FS.
AUTHOR
USEPA
USEPA
Michael G.ifford
USEPA
Ke~rySt:eet
Doug Day
John E. Aho
-
US EP A
USEPA
USE?A
US EP A
USEPA
USE?A
USEPA
MPCA
Lette: to E.A. Hickok f:om MPCA
MPC~ requesti~g modificatior.s
to the QA/QC Pla~ ar.d Safety
Plan.
2.
DATE:
7/1981
none
8/10/82
none
1983
9/10/81
6/28/82
4/19a4
4/198-i
4/1984
4/1984
4/1984
4/1984
6/13/84
6/19/84
,. .' "
NO. OF PAGE:.
28
1
25
5-
1
5
16
32
70
80
6
6
35
3
13
. . ~. '.
, ',' . ',: :." ,.
J .~. '" ",..~" ~'.:.' ~"'. ',:. .;:.~ ;. ""~' .~: '~:",1': ::." .:> ',:~,,~"; '::~:>.):' '.".' 'I....,:.~'~\!~:~~{:.~: ~~!.??~:~:~;~/~; ~~;>f:;~~' ~;;~; :.~:: .?~~t:;.:::}: :.~:~:.:~-:~: "\~:~~ :,.<~- >' .': ;<~. ~'. :~~ ~~.-.:.(~:~ '.'~'~:'
-------
4.
S.
6.
7.
8.
1'ITLE/SUBJ EC1'
IV.
WORKPLAN CORRESPONDENCE
3.
Lette~ to Ke~ry Street
from Onan stating that
the new consultant is
Conestoga-Rove~s & Ass.
Letter toWDE from MPCA
Letter to Patricia
Lindquist, City Admin.
of Andove~, Minn. from
MPCA rega~ding the
testing of residential
water wells.
Letter from MPCA to
Elldfard Briesemeister
Mngr of Manuf., Foley
Belsaw
Letter from CRA to MPCA
regarding sa~pling
changes.
Letter from CRA to MPCA
regarding changes in
sampl ing .
V. OAPP (3)
1. Letter which approves
the three OAP~ plans.
2 . OA/OC.
Landfill a~d Pit RI/FS
3. Letter from MPCA to USEPA
regarding report modifi-
catio~s.
4. OAPP
5. OAPP
VI.
VII.
VIII.
IX.
1.
2.
OA/OC DATA
AV AILABLE AT
536 S. Clark
Ch i c ag 0 , I 11 .
RI/FS: RE~EDIAL
IN\! ESTIGATION
AND BIBLIOGRAPHY
SUP~LE:-tE~TAL
REMEDIAL INVESTIGATION
DETAILED ANALYSIS
REPORT
This is a final
d~aft of the
feasibility study.
(also pps. 104-166
have. bee:': pulled
out and placed in
the Public E:':da~ger-
ment file.)
Appendices
AUTHOR
Bruce Borgerding
ONAN Corp.
DATE
NO. OE' PAG2:
7/27/84
"\
Thomas Ka1itowski 8/1/84
MPCA
Clifford A~derson
MPCA
Alan W. VanNorman
CRA
3
7/30/84
1
8/30/84
3
Richard G. Shepherd 9/17/84
CRA at tor:'l&y
6
USEPA 2/22/87
Norman R. Niedergang
Hickok' Ass. 4/1984
MPCA
CRA
CRA
CRA
CRA
CRA
CRA
3
9='
6/1/84
10U
2/22/85
8/7/86
455
80
3/1986
142
257
9/1986
10/1986
37
275
10/1986
275
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TITI..E/SUBJ ECT AUTHOR DATE PAGES
X. PUBLIC HEALTH CRA 10/1986 103
F:V ALU A 1'1 ON
XI. DECISION DOCUMENTS
1. Alternative Selection CRA 10/1986 13
(pulled from FS)
XII. ROD NOT AVAILABLE YET.
XIII. COMMUNITY RELA~IONS
WE ARE WAITING FOR ADDITIONAL
DOCUMENTS FROM THE STATE OF
MINNESOTA.
1. Community Relations Pla~ MPCA 7/18/83 5
2. Press Release. ? 3/23/84 2
3. Letter from Bowman and David Graves 3/29/85 5
Bowman to MPCA
4. C~ty of ~~oka to USEPA Albert Kordiak 1/22/85 2
S. Letter from MPCA to T. Kalitowski 2/26/85 3
Ho~orable Albert A.
Kordiak, ~~oka C~ty.
Brd. of Commisso
6. Canonie E~grs to USEPA Ca~onie Engrs.' 5/24/84 1
7. MPCA to Mayor of Andover Douglas N. Day 5/22/8.4 2
8. News Release EPA 3/23/84 2
9. MPCA Letter to USEPA Susa~ M. 12/2/83 2
Brustma:'1
10. Valdas V. Adamkus to Valdas Adamkus 11/28/83 3
S~nator Rudy Boschwitz
11. Request for Information teerry Street 11/29/83 4
from Minneapolis Star
Tribune
12. Valdas V. Adamkus to Valdas Ad amI<. us 11/15/83 6
Senator Rudy Boschwitz
,~ 13. Valdas V. Adaml<.us to Valdas Adamkus 5/17/83 11
S~nator Rudy Boschwitz
14. Valdas V. Adamkus to . . . 5/12/83 3
Senator Rudy Boschwitz
15. Copy of NFL sent to Ke::-ry Street 5/17/83 2
Irene Lund.
XIV. ENFORCE:-tENT
1. Conse:'1t Orde:- USEPA ? 50
(signatures a::-e
miss ing) .
." .'. '.. ",' . , -." - . .. . ~. " . , ." .". -. ,',.,' ~ .. '. . ., ". -'. . ,"
-. . ," .. ", " - .
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,,' ",
TI TlE/ SUB JECT AUTHOR DATE PAGES
XV. Additional Items
1. Comment Letter on OAR Kerry Street 8/29/87 7
from Kerry Street (U.S. EPA)
to Al an Van Norman
2. Response Letter on OAR SW...28 Group 9/14/87 . 32
from SW-28 Group to
U.S. EPA and MPCA
3. Transcript of Proceedings Mary Ann Hintz 9/14/87 68
for Public Meeting on FS (Court Reporter)
4. FS Comment Letter from SW-28 Group 9/10/87 3
SW-28 Group to U.S. EPA
and MPCA
5. FS Comment Letter on OAR CRA 9/24/87 4
from CRA to U.S. EPA
and MPCA
6. MPCA Memo on 1/28/87 Sam p 1 i n g Michael Convery 2/23/87 15
of Coon Creek
7. Agenda, Fac t Sheet and Press MPCA and U.S. EPA 9/3/87 5
Release for Public Meeting on FS
8. Letter to SW-28 Group from MPCA Thomas Kal itowski 10/12/87 3
on Pub 1 i c Commen ts
9. MPCA and U.S. EPA Response to Thomas Ka 1 i tows k i 11/4/87 10
SW-28 Group 9/14/87
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