United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R05-91/166
August 1991
Superfund
Record of Decision:
South Macomb Disposal #9,
9A, Ml
-------
60272-101
REPORT DOCUMENTATION i. REPORT Ma 2.
PAGE EPA/ROD/R05-91/166
4. TMeendSuMMe
SUPERFUND RECORD OF DECISION
South Macomb Disposal #9, 9A, MI
First Remedial Action
7. Au«K>r(s)
». Performing Orgslnlzrton Nun* snd Address
12. Sponsoring OrgsrtuUon Nune tnd Address
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
3. Recipient's Accession No.
5. Report Dste
08/13/91
6.
8. Performing Organization Rept No.
10. Pro(ecVTask/Wort( Unit No.
11. Contrad(C) or Grant(G) No.
(C)
(G)
13. Type of Raport & Period Covered
800/000
14.
IS. Supplementary Noln
18. Abstract (Unit: 200 words)
The 159-acre South Macomb Disposal #9, 9A site contains two inactive municipal
landfills in Macomb Township, Macomb County, Michigan. Land use in the area is
predominantly agricultural and rural, with several adjacent residences. A small
stream, the McBride Drain, runs along the western and southern boundaries of the site,
and there is a possible wetlands area located at the site. Until 1989, the estimated
34 residents in the immediate vicinity of the site used shallow and intermediate
aquifers associated with contamination from landfills as their drinking water supply.
From 1968 to 1975, South Macomb Disposal Authority (SMDA), a municipal corporation,
used the site to facilitate the management and disposal of municipal refuse for five
towns in Macomb County. SMDA acquired the 75-acre area #9 in 1968, accepted 680,000
cubic yards of municipal waste, and capped the area with soil in 1971. Subsequently,
SMDA acquired the adjacent 84-acre area 9A in 1970, filled it with 1,200,000 cubic
yards of municipal waste, and capped the area with a mixture of sand, clay and silt in
1975. As a result of reported fish kills and continued reports of leachate seepage
into McBride Drain, a number of State investigations between 1976 and 1982 verified
that the site was the source of the leachate problem and prompted SMDA to upgrade and
(See Attached Page)
17. Document Analysis a. Descriptors
Record of Decision - South Macomb Disposal #9, 9A, MI
First Remedial Action
Contaminated Medium: gw
Key Contaminants: VOCs (benzene, toluene), other organics (phenols), and metals
(arsenic and chromium)
c. COSATI Held/Group
18. AvailsbUty SUtermnt
IS. Security Class (This Report)
None
20. Security Clsss (This Page)
None
21. No. of Pages
75
22. Price
(See ANSt-ZM.18)
SM Inttructiont on Revertt
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-35)
Deportment of Commerce
-------
EPA/ROD/R05-91/166
South Macomb Disposal #9, 9A, MI
First Remedial Action
Abstract (Continued)
expand leachate collection systems along various portions of area 9A. From 1983 to 1984,
the State investigations detected VOC-contaminated ground water in several residential
wells near the site. Consequently, from 1985 to 1988, SMDA constructed an additional
leachate collection system on area #9, and a slurry wall across the northern portion of
area #9. In 1989, Macomb Township connected residences near the site to the municipal
water supply. This Record of Decision (ROD) addresses onsite contaminated ground water
as Operable Unit 1 (OU1). A future ROD will address the landfill contents as OU2. The
primary contaminants of concern affecting the ground water are VOCs including benzene and
toluene; other organics including phenols; and metals including arsenic and chromium.
The selected remedial action for this site includes installing extraction wells in the
intermediate aquifer, both within and outside the site boundary and subsurface drains in
the shallow aquifer along the periphery of the waste deposits in both sites #9 and 9A;
collecting ground water and leachate in a series of collection sumps, followed by pumping
to the onsite ground water treatment system; treating the contaminated ground water
onsite using air stripping, followed by granular activated carbon,
oxidation/precipitation, and granular media filtration, with onsite discharge of the
treated water to McBride Drain; disposing of any treatment residuals offsite; extending
the existing slurry wall along the east side of area #9; providing a municipal water
supply to any residences within a one-half mile radius of the site that are not currently
attached; conducting long-term monitoring of ground water, surface water, sediment of
McBride Drain, leachate, air, and residential wells; and implementing institutional
controls including deed and ground water restrictions, and site access restrictions
including fencing. The estimated present worth cost for this remedial action is
$9,264,000, which includes an annual O&M cost of $224,000.
PERFORMANCE STANDARDS OR GOALS: Chemical-specific ground water clean-up goals are based
on the more stringent of State standards or SDWA MCLs, and include benzene 2 ug/1
(State), toluene 100 ug/1 (State), phenols 1,100 ug/1 (State), arsenic 1 ug/1 (State),
and chromium 100 ug/1 (MCL).
-------
DECLARATION
for the
RECORD OF DECISION
South Macomb Disposal Authority/ Landfills 9 and 9a
Macomb County, Michigan
Statement of Basis and Purpose ^
This decision document presents the selected remedial action for
the South Macomb Disposal Authority, Landfills 9 and 9a, .(SMDA)
Site, in Macomb County, Michigan, which was chosen in accordance
with the requirements of the Comprehensive Environmental Response,
Compensation, and Liability Act of 1980 (CERCLA), as amended by the
Superfund Amendments and Reauthorization Act of 1986 (SARA) and, to
the extent practicable, the National Oil and Hazardous Substances
Pollution Contingency Plan (NCP). This decision is based on the
administrative record for this Site.
The State of Michigan concurs with the selected remedy. The letter
of concurrence is attached.
Assessment of the Site
Actual or threatened releases of hazardous substances from this
Site, if not addressed by implementing the response action selected
in this Record of Decision (ROD), may present an imminent and
substantial endangerment to public health, welfare, or the
environment.
Description of the Selected Remedy
The selected remedy is the first operable unit at the Site.
Operable units are discrete actions that comprise incremental steps
toward the final remedy. The nature of the second operable unit to
address the landfill contents will be assessed during the
performance of the first operable unit. The selected remedy treats
the greatest risk posed by conditions at the Site, exposure by
ingestion or direct contact with contaminants in the ground water.
The treatment will achieve substantial risk reduction through
extraction of the contaminated ground water at the Site, and
treatment to health-based levels.
-------
The major components of the selected remedy include the following:
• Installation of ground-water extraction wells and a
slurry wall to control the plume of contamination;
• Construction of a collection and on-site treatment system
for contaminated ground water;
• Long-term environmental monitoring;
• Connection of all residents in the immediate vicinity bf
the SMDA Site to a municipal water supply.
Declaration of Statutory Determinations
The selected remedy is protective of human health and the
environment, complies with Federal and State requirements that are
legally applicable or relevant and appropriate to the remedial
action and is cost-effective. This remedy utilizes permanent
solutions and alternative treatment technologies or resource
recovery technologies to the maximum extent practicable, and
satisfies the statutory preference for remedies that employ
treatment that reduces toxicity, mobility, or volume as a principal
element.
Because this remedy will result in hazardous substances remaining
on-site above health-based levels, a review will be conducted
within five years after commencement of remedial action to ensure
that the remedy continues to provide adequate protection of human
health and the environment.
$'. Adamkus
Regional Administrator
/Date/
-------
TABLE OF CONTENTS
A. Site Location and Description 1
B. Site History and Enforcement Activities 1
C. Highlights of Community Participation 4
D. Scope and Role of Response Action 4
E. Summary of Site Characteristics 5
F. Summary of Site Risks 9
G. Environmental Standards not met at the Site 14
H. Rationale for Further Action 16
I. Description of Alternatives 17
J. Summary of Comparative Analysis of Alternatives ... 22
K. The Selected Remedy 26
L. Statutory Determinations 28
Responsiveness Summary 35
-------
FIGURES and TABLES
Figures
1. Location Map 1
2. Site Map 1
3. Hydrogeology 5
4. Extent of Ground Water Contamination 8
5. Alternative 2, Environmental Monitoring 17
6. Alternative 2, Aquifer Monitoring Locations .... 17
7. Alternative 3, Components 18
8. Alternative 3, Ground-Water Treatment Schematic ... 20
9. Alternative 3, Municipal Water Supply Map 21
Tables
1. Contaminant Concentrations in Leachate 8
2. Contaminant Concentrations, Shallow Aquifer 8
3. Contaminant Concentrations, Intermediate Aquifer ... 8
4. Distribution of Contaminants 9
5. Risk Assessment Summary Table 12
6. Chemicals of Concern in Ground Water, Concentrations and
Cleanup Standards 14
7. Cost Comparison 26
-------
DECISION SUMMARY
A. Site Location and Description
The South Macomb Disposal Authority (SMDA) Landfill site is located
at Foss Road and 24 Mile Road, in Macomb Township, Macomb County,
Michigan (see Figure 1) , about 25 miles north of Detroit, Michigan.
The 159-acre site consists of two adjacent, rectangular-shaped
municipal landfills, sites 9 and 9a, as shown in Figure 2. The
landfills received municipal waste from 1968 until closure in 1975.
i'
The surrounding area is generally rural/agricultural; residences
and farm fields are located to the north, east, and west within
several, hundred feet of the landfill; a golf course and McBride
Drain, a small stream, border the south. Macomb Township has a
population of approximately 20,000 people. About 2,200 people live
within a three-mile radius of the site, many of whom have private
water wells as their drinking source. Thirty-four residences are
located in the immediate vicinity of the site, along 24 Mile Road,
Foss^Road, and Card Road. Most of these residents, particularly
those whose wells were historically affected by the off-site plume
of contamination, are now attached to a municipal water supply.
The drainage system for the site and immediate vicinity is McBride
Drain, a small stream heavily used for recreational and
agricultural purposes. McBride Drain flows along the western and
southern borders of the site, then south to the north branch of the
Clinton River, a distance of approximately 1.5 miles. The Clinton
River discharges directly into Lake Saint Clair, located northeast
of Detroit. The average flow for McBride Drain is 1.81 cubic feet
per second (cfs). The average flow for the Clinton River is 127
cfs.
No wetlands were identified by the State of Michigan or the
Department of Interior upon initial review of the workplan for the
Remedial Investigation (RI) or consequent reviews of the RI and the
Feasibility Study (FS). A preliminary environmental assessment has
been performed by the U.S. Environmental Protection Agency (EPA)
that indicated wetlands may be present; a more in-depth assessment
will be performed during the design phase of the remedial action.
B. Site History and Enforcement Activities
The site was operated as municipal landfills by the SMDA from 1968
to 1975. SMDA is a municipal corporation formed in the late 1960s
by five towns in southern Macomb County, Roseville, East Detroit,
Center Line, Warren, and St. Clair Shores, to facilitate the
management and disposal of municipal refuse for its members.
SMDA's board of directors consists of mayors from each of the
member towns. The landfills consist entirely of municipal waste.
While hazardous substances are present in the leachate produced in
-------
SOUTH \
MACOMB
FIGURE 1
South Macomb Disposal Authority
Site Location Map
-------
' '..21
SOURCE: U.S.G.S. 7.51 topographic map.
Waldenburg Quadrangle Michigan.
Dated 1968 Photorevised 1973 and 1980
Scale: K-2000'.
QUADRANGLE LOCATION
2000
LEGEND
DESIGNATES DISPOSAL
SITES 9 AND 9A
ORIGINAL
FIGURE 2
-------
the landfill, there is no documentation indicating that non-
household waste as defined by the Resource Conservation and
Recovery Act (RCRA) and/or industrial waste was disposed of at the
site.
SMDA acquired site 9, 75 acres, in 1968 and operated it until 1971.
During this time, the site accepted about 680,000 cubic yards of
municipal waste, some of which was placed directly into former
mining pits containing water. In 1971, the site was closed and
capped with soil. Subsequent reviews of site conditions by the
Michigan Department of Natural Resources (MDNR) indicated that the
soil cover thickness was less than the two feet required by
Michigan law. Title to site 9 was transferred to Macomb Township
in 1975.
As site 9 approached its operating capacity in 1970, SMDA purchased
84 acres of adjacent farm land to the west. This site, called 9a,
began operations in 1971, accepting about 1,200,000 cubic yards of
municipal waste. In 1975, at the completion of filling operations,
site 9a was closed and covered with two feet of a mixture of sand,
clay and silt.
During and after the operation of sites 9 and 9a, leachate from the
landfills seeped into McBride Drain and flowed onto adjacent
property, causing a ground-water contamination problem. Leachate
discharges from the site were observed by the MDNR in 1971, 1975,
1976, and 1983. Complaints of fish kills and continued leachate
seepage into McBride Drain prompted an MDNR investigation in 1976.
The investigation verified the complaints and resulted in improved
leachate management practices by SMDA. SMDA also improved erosion
and sedimentation controls, tilling and regrading the landfill
surface. However, leachate outbreaks occurred again north and
south of the site in 1980 and 1982. In response to the 1980
leachate outbreak, SMDA installed a leachate collection system
along the south-central and northern portions of site 9a.
In 1982, residents north of the site complained about a red slime
that seeped into their basements. The substance was tested by the
State and found not to be toxic. Residential wells were also
tested. No contamination was found in the samples. In 1983,
residents near the landfill filed suit against SMDA, Macomb County
Health Department, Macomb Township, Michigan Department of Public
Health, and the MDNR, for damages resulting from the site.
Subsequently, the State of Michigan joined the residents as
plaintiffs against SMDA and Macomb Township. The same year, the
Michigan Department of Public Health detected volatile organic
compounds (VOCs) in two residential wells near the site. These
residents were advised not to drink their water and the State
supplied bottled water. In 1984, two more residential wells were
determined to be contaminated. In 1985, the State Attorney General
obtained a circuit court order requiring SMDA to construct a
leachate collection system on site 9 similar to the one on site 9a.
-------
MDNR proposed to EPA that SMDA sites 9 and 9a be considered for
cleanup under the Superfund program. On June 10, 1986, the site
was placed on the National Priorities List (NPL) pursuant to
Section 105 of the Comprehensive Environmental Response,
Compensation and Liability Act (CERCLA), 42 U.S.C. Section 9605,
with a Hazard Ranking System Score (HRS score) of 35.5, because of
proximity to domestic water supplies and historic information on
domestic well water quality. In May of 1987, notice letters were
mailed to potentially responsible parties (PRPs) at the site, the
South Macomb Disposal Authority (owner/operator) and Macomb
Township (owner), inviting them to negotiate for the conduct of the
Remedial Investigation/Feasibility Study (RI/FS). The PRPs
declined the opportunity to perform the RI/FS.
Under an existing remedial contract, EPA assigned the consulting
firm Of CH2M Hill the RI/FS project. Field work began in October
of 1988, about the time that SMDA, under a court order obtained by
the State, began construction of a slurry wall across the northern
edge of site 9. In 1989, Macomb Township, under a Consent Decree
with the State, began the process of connecting residences around
the site to municipal water. This process was completed by fall of
1990. This Consent Decree provides for residences to be hooked up
to the municipal water supply if contamination originating from
SMDA sites 9 and 9a is detected in their water supply in the
future.
EPA completed the RI Report in August of 1990. The draft FS was
released in September of 1990. In the intervening years since the
May 1987 negotiations for performance of the RI/FS, EPA has
determined that the five member townships of SMDA are PRPs
individually liable for CERCLA cleanup costs at the site, as are
the Macomb County Road Commission, and Van Dyke Disposal and
Wiegand Disposal, both transporters. EPA issued notice letters to
SMDA, its five member towns, Macomb Township, the Road Commission,
and Van Dyke Disposal in March 1991, and Wiegand Disposal in July
1991. EPA continues to review the evidence concerning PRPs and may
notify additional parties when it issues notice letters inviting
PRPs to negotiate to perform the Remedial Design/Remedial Action
(RD/RA) at the site.
In April 1991, a State of Michigan trial court judge ruled in the
lawsuit instituted in 1983 that SMDA must undertake for both sites
9 and 9a, remedial measures to inhibit "leachate formation,
breakouts and off-site migration" of contaminants. The court
required grading and an impermeable cap consisting of at least "an
increased slope and synthetic liner to ensure against percolation."
Also the court ordered installation of slurry walls and a leachate
collection system in addition to those already in place. Finally,
the court ordered SMDA to perform "ground-water pumping of the
contaminating plume by the purge well method."
-------
C. Highlights of Community Participation
On October 6, 1988, EPA hosted a "kickoff" meeting at the Macomb
Activities Hall in Mt. Clemens, Michigan. A community relations
plan was finalized in May 1988. An RI update letter was
distributed to the community in July of 1989. A public meeting was
held on January 20, 1990 to provide the community with test results
from residential well sampling and answer questions.
The RI/FS Report for the SMDA site was released to the public for
review on October 1, 1990. The Proposed Plan was released to the
public for comment on May 1, 1991. These two documents were made
available to the public in both the administrative record and an
information repository maintained at the EPA Docket Room in Region
V and at the Macomb County Public Library located at 16480 Hall
Road,. Mt. Clemens, Michigan. The notice of availability for these
two documents was published in the Macomb County Daily on May 1,
1991. A public comment period on the documents was held from May
1, 1991 to June 6, 1991. In addition, a public meeting was held on
May 6, 1991 at the Senior Activities Center in Mt. Clemens,
Michigan. At this meeting, representatives from EPA and MDNR
answered questions about problems at the site and the remedial
alternatives under consideration. A response to the comments
received during this period is included in the Responsiveness
Summary, which is part of this ROD.
The public participation requirements of CERCLA sections 113 (k)
(2) (B) (i-v) and 117 have been met in the remedy selection
process. This decision document presents the selected remedial
action for the SMDA site, in Michigan, chosen in accordance with
CERCLA, as amended by SARA and, to the extent practicable, the
National Contingency Plan (NCP) . The decision for this site is
based on the administrative record.
D. Scope and Role of Operable Unit Within Site Strategy
The cleanup goals for this operable unit are to:
• Prevent direct contact with leachate and contaminated
ground-water;
• Prevent off-site migration of the contaminants in the
ground-water; and
• Remove and treat contaminants in ground-water.
These goals will be met through the proposed cleanup action, which
includes an extension of the existing slurry wall on site 9;
installation of ground-water extraction wells to control the plume
of contamination; a collection/treatment system for contaminated
ground-water; long-term environmental monitoring of ground-water;
-------
and connection of all residents in the vicinity of the SMDA site to
the municipal water supply. The proposed cleanup action is the
first operable unit at the site. Operable units are discrete
actions that comprise incremental steps toward the final remedy.
The nature of a second operable unit to address the landfill
contents will be assessed during performance of the first operable
unit.
E. Summary of Site Characteristics
The remedial investigation involved extensive sampling and analysis
of ground-water, air, surface water, sediment, leachate, subsurface
soil, and surface soil. Water samples were collected from some
residential wells around the site. Site geology, landfill
characteristics, and ground-water flow patterns were also examined.
Based on the results of the RI, EPA determined that the greatest
threat to human health and the environment by this site is through
exposure, by direct contact or ingestion, to the VOCs, semi-
volatile organic compounds (SVOCs), and inorganic compounds, such
as m'etals, present in the leachate and ground-water. The following
conditions were observed at the site:
1. Topography
The area surrounding the site is basically flat. The landfill
operation has not resulted in any significant increase in
topographic relief. The elevation of the ground surface
surrounding the landfill ranges from approximately 605 feet
(ft.) to 615 ft. above mean sea level (MSL) . The site surface
rises approximately 6 to 8 feet above the original land
surface.
2. Hydrogeology
Three aquifers are located beneath the SMDA site: a shallow,
an intermediate, and a deep aquifer. A ground-water divide
defines an approximate ground-water basin containing about 95%
of the SMDA site as shown in Figure 3. Ground water on either
side of the divide may flow parallel to or away from the
divide but never across the divide into another basin. The
three aquifers are considered Class II aquifers by EPA because
they are currently used or are potentially available for
drinking water or other beneficial uses.
a. Shallow Aquifer. The shallow aquifer is
discontinuous in nature. This unit generally includes
saturated surficial sands, fill, and/or refuse where
these materials reside above the shallow clay lacustrine
unit. Where the lacustrine clay is absent, the shallow
aquifer material is contiguous with the intermediate
-------
0 «00
FIGURE 3
MYOnOCtOlOCIC CONOI10N5-
SMALIOW AND INTtRUCDIAIC
AOUirtBS
-------
aquifer and an unobstructed flow path exists between
aquifers. This condition is most evident at site 9. The
shallow aquifer extends down from approximately 615 ft.
MSL to 600 ft. MSL.
Ground-water velocity in the shallow aquifer is
approximately 0.61 feet per day. Most of this flow
appears to be captured by the existing leachate
collection system. In the absence of the system, the
shallow aquifer would tend to discharge directly to
McBride Drain through seepage, leachate seeps or springs.
Ground-water flow tends to be radial on the north side of
the hydraulic divide and south/west on the south side as
shown in Figure 3.
b. Intermediate Aquifer. The intermediate aquifer.
consists of a lacustrine sand layer residing atop the
fine grained glacial till and below the discontinuous
lacustrine clay. The intermediate aquifer is generally
confined where the overlying silty clay is present, and
under water table conditions (unconfined) where it is
absent. Where the clay unit is absent, the intermediate
aquifer receives discharge from the shallow aquifer. The
intermediate aquifer extends down from approximately 605
ft. MSL to 570 ft. MSL. Ground-water velocity in the
intermediate aquifer is approximately 0.051 feet per day.
Ground-water flow is generally southward toward McBride
Drain.
c. Deep Aquifer. The deep aquifer includes a sandy
glacial till layer sandwiched between upper and lower
fine-grained till units. It is confined over the entire
study area and buffered from the potential effects of the
SMDA site by the intermediate aquifer and two aquitards.
The deep aquifer extends from approximately 565 ft. MSL
to 555 ft. MSL. Ground-water velocity in the deep
aquifer is approximately 0.0041 feet per day. Ground-
water flow is generally to the southeast at a uniform low
gradient.
3. Landfills 9 and 9a
The partially fenced flat landfills are covered by trees and
grasses. Surface water drains collect runoff, discharging it
into a marshy area in the southwest corner of site 9, and
directly into McBride Drain. Erosion is occurring along the
perimeter of the landfill where steep, sandy slopes support
sparse vegetation.
The site 9 landfill cover, thin and permeable, is considered
a primary facilitator of leachate production and consequent
contamination of the ground water. Refuse in site 9, up to 25
-------
feet thick, is in direct contact with the shallow aquifer and
intermediate aquifer.
The site 9a landfill cover is 2 to 3 feet thick and consists
of a mixture of sand, clay and silt. Refuse in site 9a is up
to 20 feet thick. As in site 9, most refuse is in direct
contact with the shallow aquifer. Only a small portion,
however, is in direct contact with the intermediate aquifer.
4. Leachate Collection Systems and Slurry Wall
Three leachate collection systems have been installed at the
site. The most recent system was constructed in late 1988
along the northern edge of site 9, roughly in a line
paralleling 24 Mile Road, 250 feet south of the property line.
This system includes a slurry wall which extends about 40 feet
through the shallow and intermediate aquifers and was keyed
into the till in what appears to be a successful attempt to
prevent the off-site migration of the plume of contamination
to the north. A subsurface drain is located on the landfill
side of the slurry wall at an elevation near the bottom of the
shallow aquifer.
A second system was constructed along the south-central
portion of site 9a following a leachate outbreak in 1980.
This system, consisting of a six-inch underdrain which flows
to a holding tank, was installed at an elevation above McBride
Drain, entirely within the waste at site 9a, and extends for
approximately 2,000 feet along the southern edge of the site.
A small north-south lateral about 100 feet long exists in the
southeastern part of site 9a. A third system was installed
along the north side of site 9a.
Approximately 200,000 gallons of leachate per month are
removed by tankers from the collection basins and treated at
an off-site licensed wastewater treatment facility, City
Environmental Inc. in Detroit, Michigan.
5. Contamination
a. Source
The source of contamination from this site is the
landfilled waste. Much of the landfilled waste, up to 25
feet deep, is in direct contact with the shallow and
intermediate aquifer ground water which means that the
waste is in direct contact with laterally moving ground
water. Leachate is produced in two ways: 1) by the
horizontal movement of ground water through the waste
and, 2) by the vertical movement of precipitation down
through the cap and into the waste mass. Both means of
leachate production are present at the site.
-------
The presence of hazardous constituents in the waste mass
is indicated by the chemical composition of the leachate.
Volatile and semi-volatile organic compounds, inorganic
compounds and metals were detected in the leachate
including arsenic, methylene chloride, vinyl chloride,
and cadmium. Table 1 lists the concentrations of
contaminants of concern in the leachate.
The leachate produced and released by the site has
contaminated ground water, and has historically impacted
surface water, and has the potential to impact sediments
at and near the site. ;.
b. Ground Water
Three aquifers exist beneath the site: a shallow
aquifer, an intermediate aquifer, and a deep aquifer.
i. Shallow Aquifer. Leachate from the landfill
containing VOCs, SVOCs, and metals has seeped
into and contaminated the shallow aquifer as
shown in Figure 4. The contaminants include
those found in the leachate samples taken from
the leachate collection system. Table 2
summarizes the concentrations of contaminants
found in the shallow aquifer.
ii. Intermediate Aquifer. Leachate from the
landfills has contaminated the intermediate
aquifer to a lesser extent. However, in most
of site 9 and in portions of site 9a, the
shallow aquifer connects with the intermediate
aquifer, allowing a free flow of contaminants
between the two aquifers. Figure 4
illustrates the plume of contamination. Table
3 summarizes the concentrations of
contaminants found in the intermediate
aquifer.
iii. Deep Aquifer. No evidence of contamination
was found in the deep, confined aquifer.
Although contaminants were detected in the ground-water
beyond the landfill boundaries as indicated by the
results of the residential well and off-site monitoring
well sampling, no organic compounds were detected at
levels exceeding Federal drinking-water quality
standards. Some wells contained levels of inorganic
compounds such as iron or barium that exceeded MCLs.
These compounds occur naturally in local ground-water and
may be related to natural conditions. However, since the
landfill will continue to produce leachate, there is a
8
-------
TA«E,, ju.t IN; NT. .1969
lortiTO' in(
Wvl
«W1CJ
•U106
•WI07
MlQfie
HW1 lOd
•will
•U112
•W1I5 ' *
Ml 16
•W117
•W1 IB
"U20I
•U203
•W207
HW209
•U21 1
•J213
•W217
Hull?
'01. om.
Scl'OS
Cwv.
<«6/l)
U60
JilC
JWO
1010
1560
noo
301
426
715
1150
1060 \.
712 '
35S
£23
935
1510
5«w
1500
kfitt: «t( nond«t«ct ions cssipned
vtluc • 1/2 delect, linit.
MONITORING WELL LOCATION
CONTOUR LINE OF COUAL TOTAL
-1000 DISSOLVED SOLIDS CONCENTRATION
CONTOUR.INTERVAL = 1000
^
FIGURE 4 •
TOTAL DISSOLVED SOLIDS.
ISOCONCENTRATION CONTOUR MAP
-------
TABLE »
MAXIMUM CONCENTRATIONS DETECTED
IN LEACHATE
SOUTH HACOMB DISPOSAL AUTHORITY SITE
Parameter •
Acetone
2-Butanone ' •
1,2-Dichloroethene
Methylene Chloride
Toluene
Benzyl Alcohol
Diethylphthalate
4-Methylphenol
Phenol
Aluminum
Antimony
;, Arsenic
Barium
Cadmium
Calcium
Cobalt
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Potassium
Silver
Sodium
Zinc
*Total Suspended Sol Ids
*Total Dissolved Solids
*Total Alkalinity
*011 and Grease
*Chlor1de
*Sulfate
*Biolog1cal Oxygen Demand
*Chem1cal Oxygen Demand
Value
2400
11000
470
3100
530
1600
1100
17000
4600
233
528
20
542
365
3110000
258
2510000
68
500000
33300
70001
238
1450000
6
1210000
56500
13.C
1130
7900
1070
1470
860
2200
44400
All values except (*) are presented 1n mlcrograms per Ijter (ug/1)
* - mg/1
-------
Parameter
CO..TKMNANT CONCENTRATIONS DETECTED
SOUTH ™THE SHALLOW AQUIFER ™
SOUTH MACOMB DISPOSAL AUTHORITY SITE
Maximum DetectedValue
Acetone
Benzene
2-Butanone
Chlorobenzene
1,2-Dichloroethene (total)
Ethylbenzene
Methylene Chloride
4-Methy1-2-Pentanone
Toluene
Total Xylenes
Bis(2-ethylhexyl)phthalate
4-Chloro-3-Methylphenol
1,4-Dichlorobenzene
4-Hethylphenol
Phenol
Aluminum
Antimony
Arsenic
Barium
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Potassium
Silver
Sodium
Vanadium
Zinc
*Total Suspended Sblids
*Total Dissolved Solids
*Total Alkalinity
*0il and Grease
*Chloride
*Sulfate
*BiologiCefl Oxygen Demand
*Chemical Oxygen Demand fcuuuu
All values except (*) are presented in micrograms per liter
* - mg/1
B = Concentrations are below background in this area.
NA = Not available
9300
8
11000
25
560
40
1700
680
1400
260
32
14
8
15000
2100
4150
837
79
886
491 •
629000
136
187
86
459000
1260
139000
13000
1.4
443
277000
43
510000
273
6030
760
14200
2780
732
710
60
19000
28000
An'thmetir
4135.8
4.3
4577.5
10.0
211.3.
15.0
767.9
173.8
601.3
112.4
NA
8.0
6.0
3753.8
528.8
1750
219
20
B
125
B
B
52
30
124130
362
B
3540
B
121
79807
12
144400
71
3140
NA
NA
NA
NA
NA
NA
NA
NA
(ug/i).
-------
TABLE 3
CONTAMINANT CONCENTRATIONS DETECTED
IN THE INTERMEDIATE AQUIFER
SOUTH MACOMB DISPOSAL AUTHORITY SITE
Parameter
Acetone
Benzene
2-Butanone
Chloroethane
1,1-Dichloroethane
1,2-Dichloroethene (total)
1,2-Dichloropropane
Ethyl benzene
Methylene Chloride
4-Methyl-2-Pentanone
Toluene
Total Xylenes
Vinyl Chloride
Benzoic Acid
Bis(2- ethylhexyl)phthalate
Diethylphthalate
Isophorone
2-Methylphenol
4-Methylphenol
Pentachlorophenol
Phenol
1,2,4-Trichlorobenzene
Beta-BHC
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Potassium
Selenium
Silver
Sodium
. .Thallium
** Vanadium
Zinc
Maximum Detected Value Arithmetic Mean
1000
22
3200
8
8
4
23
3
19
96
3700
11
8
53
210
60
8
20
370
50
19
12
0.069
956000
256
219
3660
17.6
31
4020000
692
367
950
717000
481
909000
14300
13
927
659000
28.5
54
. 526000
3.2
871
308000
95.6
4.1
537.5
5.2
3.0
2.7
3.7
2.5
3.5
10.4
338.8
3.0
5.2
26.8
NA
8.4
8.0
5.9
27.8
27.8
5.9
5.4
0.03
75440
B
35
1720
4.5
B
794690
162
91
263
135760
74
139690
4620
2
274
97850
4.6
B
157340
B
173
7746
-------
f.
TABLE 3 (Continued)
CONTAMINANT CONCENTRATIONS DETECTED
IN THE INTERMEDIATE AQUIFER
SOUTH MACOMB DISPOSAL AUTHORITY SITE
Parameter Value
*Total Suspended Solids 116000
*Total Dissolved Solids 4010
*Total Alkalinity 2870
*Chloride 1070
*Sulfate 112
*Biological Oxygen Demand 1460
*Chemical Oxygen Demand 1520
ji All values except (*) are presented in micrograms per liter (ug/1).
* - mg/1
li
0
D
L
I.
-------
potential for the contaminant plume to move off-site in
the future as it has in the past.
c. Soils
Surface soil samples were taken at background locations, as
well as on and off-site. While no contaminants were detected
above background in the on- and off-site surface soil, the
subsurface soil samples on-site were contaminated with a wide
variety of site-related organic and inorganic substances as
shown in Table 4.
d. Surface Water and Sediments.
While leachate outbreaks have impacted McBride Drain in the
past resulting in fish kills, leachate and contaminated ground
water appeared to be having little measured effect on the
surface water and sediment of McBride Drain, since the
construction of the leachate collection systems and the slurry
wall, as indicated by surface water and sediment samples taken
during the investigation. The landfill will, however,
continue to produce and potentially discharge hazardous
leachate into the marshy areas and surface waters, if no
action is taken. In this case, measurable adverse effects on
McBride Drain, and consequently the Clinton River, may occur
in the future.
F. Summary of Site Risks
The analytical data collected during the RI and the public
health/environmental assessment indicated the presence of
contaminants in various media at levels that may present a risk to
human health. Pursuant to the NCP, a baseline risk assessment was
performed based on present conditions at the site. The baseline
risk assessment assumes no corrective action will take place and
that no site-use restrictions or institutional controls such as
fencing, ground-water use restrictions or construction restrictions
will be imposed. The risk assessment then determines actual or
potential risks or toxic effects the chemical contaminants at the
site pose under current and future land use assumptions. The
baseline risk assessment included the following assumptions:
The aquifers contaminated by the site may be used as a
drinking water source;
Parts of the site may be used for residential development;
Access restrictions such as fencing of the site will not be
implemented; and
No ground-water use restrictions will be enforced.
-------
TABLED
Groundwater Residential
Wells
Acetone
Benzene
2-Butanone
Carbon dijulflde
Carbon tetrachlorlde
Chloroethane (c)
Chloroform
1.1-Olchloroethant
1.2-Oichloroethylene
Ethylbenzene
2-Hexanone (c)
Methylen* chloride
4-Methyl-2-pentanont
Styrene
1.1.2.2-Tetrachloroetnane
Tetrachloroethylene
Toluene
I,l.l-Tr1ch1oroethan«
Tr1chloroethylen«
Vinyl chlorld*
Xy'»nes
Seral-volitiles
Benzole tcld
Bls(2-ethylhexyl)phth*laU
Butyl benzyl pnthalate
Chloro benzene
4-Chloro-3-fflethylpbenol (c)
1.4-Oichlorobenzene
01»:hylphthalate
Oi-n-butyl pnthalatt
Fluorantnene
Isophoront
2-Methylphanol
4-M«thylphefiol
4-Nltrophenol (c)
Pentachlorophenol
Phenanthrtn*
Phenol
Pyrene
J.2,4-TpIchlorobenzen*
2.4.5-Trlchloroph«flol
PesiddM/PCfls
Bata-BHC
Heptachlor
PCB-1232
X
X (b)
X (b)
X (a)
X (b)
X (b)
X
J X (b)
x x
X (b)
X X (b)
X (b)
X (b)
. 51.']
Ul]
A
x (b;
x
X
x (b)
x (b)
X
X
X (b)
X
X (b)
X
X
X
X (b)
X
X fM
X (a)
X (b)
5!:)
X
X
X
X (b)
x (b)
X
X
X
X
X
X
X
x (b)
X (b)
X
X
X (b)
X (b)
X
X (b)
X
X (b)
X(b)
X r
X
X
POOR QUALITY
ORIGINAL
-------
G
0
r
CHEMICALS o^ PUIINMAI co-*C£s«
SOUTH KACOMB SITE LO""K"
ym,
MEDIUM
Surface Sediment, Surface Subsurface
Water
X
X
Soil
Chemical
Aluminum (c)
Antimony
. Arsenic
Barium
Beryllium
Cadmium
Calcium (c)
Chromium
Cobalt (c)
Copper
Iron (c)
Lead (c)
Magnesium (c)
Manganese
Mercury
Nickel
Potass tun (c)
Selenium
Silver
Sodium (c)
Thallium
Vanadium
Zinc
Cyanide^"
a) Detected In upcradlent or background staples it Jiatlar levels.
b Detected In only one suple.
c No human health toxtclty criteria available for this chealejl.
d] Detected on-ilte only
X
X
X
X
Soil
X
X
X
X
X
X
X
X
X
X
X
X
Alr 6round*ater
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
x •
X
X
X
X
X
"esidential
Veils
X
X
X
X
POOR QUALITY
ORIGINAL
-------
1. Contaminant Identification
The medium of concern for human exposures was identified
primarily as ground water which has been contaminated by
leachate from the landfills. The contaminants of concern
selected for non-carcinogenic risk characterization in ground
water were:
Acetone 2-Butanone Methylene chloride
1,2-Dichloroethlene 4-Methyl-2-pentanone
4-Methylphenol Phenol Toluene
Antimony Arsenic Barium
Cadmium Chromium Copper >*•
Manganese Mercury Nickel
Selenium Silver Thallium
Vanadium Zinc
The contaminants of concern selected for carcinogenic risk
characterization in ground water were:
Vinyl Chloride Arsenic Benzene
1,1-Dichloroethane 1,4-Dichlorobenzene Methylene chloride
1,2-Dichloroethene
Analytical data gathered from surface water and sediment
samples from McBride Drain indicated no exceedances of
constituents compared to background levels in the creek. The
risk assessment concluded that the surface water and sediments
in McBride Drain do not pose a current risk to human health
and the environment.
Analytical data gathered from the residential wells sampled
and monitoring wells located outside the site boundaries
indicated no exceedances of Federal maximum contaminant levels
(MCLs) for organic constituents. Metals that exceeded MCLs
did not exceed background levels.
2. Exposure Assessment
Potential exposure to contaminants from this site can come
about through the following potential pathways or routes of
exposure:
- Incidental ingestion of ground water by trespassers, site
workers and residents;
- Dermal contact with ground water by site workers and
residents;
Inhalation of volatile organic compounds by site workers
and residents;
10
-------
- Incidental ingestion of surface and subsurface soils by
trespassers, site workers and residents; and
Dermal contact with surface and subsurface soil by
trespassers, site workers and residents.
3. Risk Characterization
The non-carcinogenic and carcinogenic health risks associated
with each of the pathways and potential receptors listed above
have been evaluated. Basic toxicity information used to
calculate risk was derived from the Integrated Risk
Information System (IRIS) and the Health Effects Assessment
Summary Tables (HEAST).
a. Non-carcinogenic Health Risks
Reference doses (RfDs) have been developed by EPA for
indicating the potential for adverse health effects from
exposure to chemicals exhibiting non-carcinogenic effects.
RfDs, which are expressed in units of mg/kg-day, are estimates
of lifetime daily exposure levels for humans, including
sensitive individuals. Estimated intakes of chemicals from
environmental media (e.g., the amount of a chemical ingested
from contaminated drinking water) can be compared to the RfD.
Rfds are derived from human epidemiological studies or animal
studies to which uncertainty factors have been applied (e.g.,
to account for the use of animal data to predict effects on
humans). These uncertainty factors help ensure that the RfDs
will not underestimate the potential for adverse non-
carcinogenic effects to occur.
Potential concern for non-carcinogenic effects of a single
contaminant in a single medium is expressed as the hazard
quotient (HQ) (or the ratio of the estimated intake derived
from the contaminant concentration in a given medium to the
contaminant's reference dose). By adding the HQs for all
contaminants within a medium or across all media to which a
given population may reasonably be exposed, the Hazard Index
(HI) can be generated. The HI provides a useful reference
point for gauging the potential significance of multiple
contaminant exposures within a single medium or across media.
Any Hazard Index value greater than 1.0 suggests that a non-
carcinogen potentially presents an unacceptable health risk.
The following table > indicates the total Hazard Index for
different scenarios involving ingestion or inhalation of, or
direct contact with, site contaminants.
11
-------
Receptor HI
Worker/Resident <1.0
On-site - surface soils,
sub-surface soils,
dust, and VOCs
Worker/Resident <1.0
Off-site - surface soils,
sub-surface soils,
dust, and VOCs
Worker/Resident •*•
On-site Ground Water
Shallow Aquifer 142.0
Intermediate Aquifer 15.7
Deep Aquifer 1.7
Resident
Off-site Ground Water 1.5
The Hazard Index for ground water exceeds the value of 1.0 for all
ground-water use. Table 5 provides an additional breakdown of
Hazard Indices relating to exposure routes.
b. Carcinogenic Health Risks
Cancer potency factors (CPFs) have been developed by EPA's
Carcinogenic Assessment Group for estimating excess lifetime
cancer risk associated with exposure to potentially
carcinogenic chemicals. CPFs, which are expressed in units of
(mg/kg-day) "1, are multiplied by the estimated intake of a
potential carcinogen, in mg/kg-day, to provide an upper-bound
estimate of the excess lifetime cancer risk associated with
exposure at that intake level. The term "upper bound"
reflects the conservative estimate of the risks calculated
from the CPF. Use of this approach makes underestimation of
the actual cancer risk highly unlikely. Cancer potency
factors are derived from the results of human epidemiological
studies or chronic animal bioassays to which animal-to-human
extrapolation and uncertainty factors have been applied (e.g. ,
to account for the use of animal data to predict effects on
humans).
Excess Lifetime Cancer Risks are determined by multiplying the
intake level with the cancer potency factor for each
contaminant of concern. These risks are probabilities that
are generally expressed in scientific notation (e.g. 1 X 10"6
or 1E-6) . An excess lifetime cancer risk of 1 X 10"6
indicates that, as a plausible upper bound, an individual has
a one in one million chance of developing cancer as a result
of site-related exposure to a carcinogen over a 70-year
12
-------
TABLE 5
QUANTITATIVE RISK ASSESSMENT SUMMARY
FUTURE LAND-USE EXPOSURE PATHWAYS
SOUTH MACOMB SITE
Exposure Upper-bound Hazard
Pathway Excess lifetime Index
Cancer risk
r
Direct contact with surface soils
by construction workers
On-site saturated soils 4E-08 7E-03
On-site unsaturated soils 1E-07 7E-03
Off-site saturated soils 3E-08 7E-03
Inhalation of volatiles by construction workers
On-site saturated soils 5E-09 6E-01
On-site unsaturated soils 2E-07 9E-02
Off-site saturated soils (a) 2E-03
Inhalation of dust by construction workers
On-site saturated soils 3E-07 5E-02
On-site unsaturated soils 1E-07 1E-02
Off-site saturated soils 1E-07 1E-02
Direct contact with surface soils by future residents 4E-08 6E-05
Use of groundwater by future residents
Shallow aquifer
Ingestion (unfiltered inorganics) 2E-03 142
Ingestion (filtered inorganics) 3E-03 29.8
Inhalation while showering 6E-07 8E-03
Intermediate aquifer south
Ingestion (unfiltered inorganics) 2E-03 15.7
Ingestion (filtered inorganics) 3E-03 7,7
Inhalation while showering 3E-09 1E-03
Intermediate aquifer north
Ingestion (unfiltered inorganics) 2E-03 7.7
Ingestion (filtered inorganics) 2E-03 5.5
Inhalation while showering 6E-08 1E-04
Deep aquifer
Ingestion (unfiltered inorganics) 9E-07 11.9
Ingestion (filtered inorganics) 9E-07 1.7
Inhalation while showering 3E-09 5E-07
-------
TABLE 5 (Con't)
QUANTITATIVE RISK ASSESSMENT SUMMARY
FUTURE LAND-USE EXPOSURE PATHWAYS
SOUTH MACOMB SITE
Exposure Upper-bound Hazard
Pathway Excess lifetime Index
Cancer risk
f
Summation across exposure pathways
Construction workers
On-site saturated soils 3E-07 6E-01
On-site unsaturated soils 4E-07 1E-02
Off-site saturated soils 1E-07 2E-02
Future residents
Shallow aquifer (unfiltered inorganics) 2E-03 142
Shallow aquifer (filtered inorganics) 3E-03 29.8
Intermediate aquifer south (unfiltered inorganics) 2E-03 15.7
Intermediate aquifer south (filtered inorganics) 2E-03 7.7
Intermediate aquifer north (unfiltered inorganics) 2E-03 7.7
Intermediate aquifer north (filtered inorganics) 2E-03 5.5
Deep aquifer (unfiltered inorganics) 9E-07 11.9
Deep aquifer (filtered inorganics) 9E-07 1.7
• •^•^•••••••^^^^^••••^••••••••••••(••••^•^^•••••••••^••••^•••••••••••^•^^^^••B ^^M» • • •» ^ mm <•• ^^^BviB^a
(a)No carcinogens detected.
-------
TABLE 5 (Con't)
QUANTITATIVE RISK ASSESSMENT SUMMARY
CURRENT LAND-USE EXPOSURE PATHWAYS
SOUTH MACOMB SITE
Exposure
Pathway
Direct contact with surface soil by trespassers
Consumption of deer meat
Consumption of fish from McBride Drain
Dermal contact while wading in McBride Drain
Inhalation by trespassers
Inhalation by nearby residents
Upper-bound Hazard
Excess lifetime Index
Cancer risk
i.
2E-08
3E-09
IE-OS
9E-13
1E-06
6E-06
4E-05
3E-10
5E-02
4E-03
1E-03
7E-03
Summation across exposure pathways:
Trespassers
Residents
IE-OS
2E-05 - 3E-05
5E-02
6E-02 - 1.5
(a) No inhalation criteria available.
(b) No carcinogens detected.
(c) No volatile detected: therefore, no inhalation risk.
-------
lifetime under the specific exposure conditions at a site.
EPA generally attempts to reduce the excess lifetime cancer
risk posed by a Superfund site to a range of 1E-04 to 1E-06 (1
in 10,000 to 1 in 1 million), with an emphasis on the most
protective end (1E-06) of the scale.
The following table indicates the Excess Lifetime Cancer Risks for
different scenarios involving irigestion or inhalation of, or direct
contact with, site contaminants.
Receptor Total Incremental Cancer Risk
'r
Worker/Resident 3E-07
On-site - surface soils,
sub-surface soils,
dust, and VOCs
Worker/Resident 1E-06
Off-site - surface soils,
sub-surface soils,
* dust, and VOCs
Worker/Resident
On-site Ground Water
Shallow Aquifer 2E-03
Intermediate Aquifer 2E-03
Deep Aquifer 9E-07
Resident
Off-site Ground Water 2E-06
The excess lifetime cancer risk for all reasonable maximum
exposure routes under the residential scenarios exceeds the
acceptable risk range of 1E-04 to 1E-06. Table 5 provides an
additional breakdown of excess lifetime cancer risk relating
to exposure routes.
4. Environmental Risks
Environmental threats posed by the site appear to be minimal
at the present time given the currently operated ground-water
controls and the resulting low concentrations of chemicals
detected during the investigation in surface soils and surface
water. A preliminary ecological assessment has been performed
at the site that indicates no critical habitats, endangered
species or habitats of endangered species at or near the site
are currently affected by site contamination. Contamination
of the wetland area and McBride Drain has, however, occurred
in the past resulting in fish kills, and could occur in the
future if current response actions should be discontinued and
further response actions not taken.
13
-------
5. Risk Summary
The principal risks at the site are derived from the potential
ingestion of contaminated ground-water from either the shallow
or intermediate aquifers. Ingestion of contaminated water
from either of these sources results in potential upperbound
excess lifetime cancer risks of 2 X 10"* and hazard indices
ranging from 5.5 to 142. Exposure to contamination in surface
and subsurface soils, either through direct contact or
inhalation of volatile vapors or contaminated dust, results in
health risks ranging from 1 X 10'6 to 2 X 10'8.
The potential excess lifetime cancer risk posed by the site
exceeds the acceptable risk range of 1 X 10"4 to 1 X 10r6
principally from the use of contaminated ground water in the
shallow and intermediate aquifers. This represents
unacceptable potential risks to human health.
The hazard indices for humans interacting with the site exceed
the acceptable hazard index of 1.0, principally from the use
of contaminated ground water in the shallow and intermediate
aquifers. This represents unacceptable potential risks to
human health.
Actual or threatened releases of hazardous substances from
this site, if not addressed by implementation of the response
action selected by this Record of Decision, may present an
imminent and substantial endangerment to public health,
welfare, or the environment. With the site in its present
condition, the off-site release of contaminants from the
landfills to ground-water, surface water (McBride Drain), and
surrounding properties (through leachate breakouts) remains a
distinct possibility.
G. Environmental Standards not met at the Site
In addition to posing unacceptable risks to receptors, SMDA sites
9 and 9a do not meet applicable or relevant and appropriate Federal
or State environmental requirements (ARARs) at this time.
1. Ground Water
Table 6 lists the representative chemicals found in the
contaminated ground water plume and the corresponding Federal
and State preliminary ground-water clean-up criteria which EPA
believes to be adequately protective. The ground water
contaminant plume contains concentrations of hazardous
substances which exceed most of these ground-water standards
and clean-up criteria. '
14
-------
TABLE 6
Chemicals of Concern in Ground Water
Concentrations & Cleanup Standards
Ground Water
Contaminant
** CATAGORY CARCINOGENS
Arsenic
1 , 1 -D i ch I broethane
1,2-Dichloropropane
1 , 4 • D i eh I orobenzene
Benzene
Methylene Chloride
Vinyl Chloride
Highest
Observed
Cone, (ppb)
64.7
3.6
5.8
8.0
22.0
1460
5.5
Excess Upper
Lifetime
Cancer Risk
2.0E-03
5.8E-06
7.0E-06
3.4E-06
4.1E-06
2.0E-04
2.3E-04
Hazard
Index
NA
NA
NA
NA
NA
NA
NA
Cancer
Risk
Target
1E-4
3.2
62
83
235
195
2.4
2.4
Cancer
Risk
Target
1E-6
0.032
0.62
0.83
2.35
1.95
0.024
0.024
SOWA
HCL
(Ppb)
50.0
5.0
75.0
5.0
2.0
2.0
Mi Act 307
Type B (ppb)
1.0 (a)*
700
1.0 (a)
5.0 (a),.
1.0 *
5.0
1.0
** CATAGORY NON CARCINOGENS
Antimony
Arsenic
Barium
Cadmium
Chromium, Total
Chromium I II
Chromium VI
Copper
Manganese
Mercury
Nickel
Selenium
Si Iver
Thallium
Vanadium
Zinc
1 , 2 -D i ch I oroethene
2-Butanone
4-Methyl -2-pentanone
4-Methylphenol
Acetone
Methylene Chloride
Phenol
Toluene
704
64.7
2410
412
282
442
11000
1.3
454
7.7
36.4
3.2
230
11000
412
10800
571
12600
7890
1460
1760
1150
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
7.3
2.7
2.0
34
2.4
0.5
2.3
0.18
0.95
0.11
0.51
1.9
1.9
2.3
0.86
9.0
0.48
1.0
3.3
1.0
.12 .
.16
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
10/5
50.0
1000
5.0
100
1300
2.0
100
50.0
50.0
2/1
70.0
5
1000
3.0*
1.0 (a)*
2000*
4.0*
7000*
2.0 *
1000*
700*
2.0*
100*
20.0 (b)*
0.1 (b)*
0.5*
4.0*
1000*
70.0
400
400
400
500 (b)
5.0
1100 (b)
100 (b)
KEY: * If local background is greater, then use the average local background.
(a) Acceptable method detection limit.
(b) Act 307 - Type B criteria for surface water (R299.5713).
-------
2. Ground Water Protection Goals and the National Contingen-
cy Plan
EPA's ground-water protection goal has been set forth in the
NCP as follows:
The national goal of the remedy selection process is to select
remedies that are protective of human health and the
environment, that maintain protection over time, and that
minimize untreated waste. Title 40 of the Code of Federal
Regulations (40 CFR) Section 300.430(a)(1)(i)).
The NCP states that EPA expects to return usable ground waters
to their beneficial uses, wherever practicable, within a time
frame that is reasonable given the particular circumstances of
the site. Whenever restoration of ground waters is not
practicable, EPA expects to prevent further migration of the
plume, prevent exposure to the contaminated ground water, and
evaluate further risk reduction. (40 CFR Section
300.430(a)(1)(iii)(F)).
Also, the NCP considers the use of institutional controls to
limit exposures to hazardous substances in the ground water:
EPA expects to use institutional controls such as water use
and deed restrictions to supplement engineering controls as
appropriate for short-and long-term management to prevent or
limit exposure to hazardous substances, pollutants, or
contaminants.... The use of institutional controls shall not
substitute for active response measures as the sole remedy
unless such response measures are determined not to be
practicable (40 CFR Section 300.430(a)(1)(iii)(D)).
3. State of Michigan Ground Water Protection Goals
Michigan Act 307 provides for remedial action, at contaminated
sites within the State, which "shall be protective of the
public health, safety, and welfare and the environment and
natural resources." Additionally, all "...remedial actions
which address the remediation of an aquifer shall provide for
removal of the hazardous substance or substances from the
aquifer...." Michigan Act 307 also provides for the
determination of acceptable criteria for ground-water
remediation at the site.
4. Clean-up Standards
EPA's ground-water clean-up policy is to attain MCLs under the
Federal Safe Drinking Water Act (SDWA); however, if clean-up
to MCLs causes the residual risk levels to exceed the 1 x 10
to 1 x 10"6 risk range, then the Agency must apply risk-based
clean-up levels to reach the goal of protectiveness (1 x 10"6
excess lifetime cancer risk).
15
-------
Michigan Act 307 Rules contain clean-up criteria which include
three different methods by which clean-up levels can be
determined. The levels are Type A, Type B, and Type C. The
methodology for Type A clean-up is based on background levels
or method detection limits for chemicals of concern. The
methodology for Type B clean-up uses standardized risk
assumptions and exposure assumptions to determine clean-up
levels which will be protective of human health, the
environment, and the use of the involved resource.
R. 299.5709, R. 299.5711, and R..299.5713 provide a thorough
explanation on how to apply the Type B clean-up to the
chemicals of concern and calculate the figures to the site.
The methodology for Type C clean-up reviews the actual
conditions of the site; the uses, present and future, of the
site; a site specific risk assessment; and cost effectiveness
analysis. R. 299.5717 provides a thorough explanation of how
to apply the Type C clean-up to the chemicals of concern.
Michigan Act 307, Type B clean-up criteria provide for the
calculation of risk-based clean-up standards at the 1 x 10'6
excess lifetime cancer risk level for each carcinogenic
compound. These standards are usually more stringent than the
corresponding MCLs or non-zero Maximum Concentration Limit
Goals (MCLGs) . EPA has determined that Michigan Act 307, Type
A and B criteria are protective and are applicable or relevant
and appropriate to the site.
Table 6 lists the Ground-water Cleanup Standards for SMDA
sites 9 and 9a.
H. Rationale for Further Action
Actual or threatened releases of hazardous substances from this
site, if not addressed by implementation of the response action
selected by this Record of Decision, may present an imminent and
substantial endangerment to public health, welfare, or the
environment. Therefore, based on the findings in the RI report and
the discussion above, a Feasibility Study (FS) was performed to
develop alternatives to address the threats at the site. The FS
report documents the risks at the site, site-specific applicable or
relevant and appropriate requirements, and the requirements of
CERCLA and the NCP, especially the ground-water protection policy,
in the derivation of remedial alternatives for the SMDA sites 9 and
9a.
I. Description of Alternatives
The alternatives analyzed for the first operable unit at SMDA sites
9 and 9a are presented below:
16
-------
Alternative l: No Action
A No Action alternative was evaluated to serve as a baseline for
comparison against the other cleanup alternatives. It assumes that
no corrective action will be taken at the site and that no
restrictions will be placed on access or future use of the site.
There are no costs associated with this alternative.
Alternative 2: Limited Action
Capital Cost: $ 427,000
Annual O&M Costs: 109,000
Present Worth: 2,192,000 '*
Years to Implement: 1 to 2
Alternative 2, illustrated in Figures 5 and 6, includes long-term
monitoring of the ground water, residential wells, surface water,
sediment, leachate, and air at the site and surrounding area;
construction of a chain link fence around the site; land use and
deed restrictions; and, attachment of selected residences to the
municipal water supply.
Long-term Monitoring; Long-term monitoring of ground water,
residential wells, surface water and sediment of McBride Drain,
leachate, and air will be performed twice a year for a minimum of
30 years at the approximate locations shown in Figures 5 and 6.
All samples with the exception of air samples will be analyzed for
the full Contract Laboratory Program (CLP) Target Compound List
(TCL) and Target Analyte List (TAL) for both organic and inorganic
contaminants with the exception of pesticides/PCBs. At the end of
30 years EPA will determine the need for additional monitoring.
Long-term monitoring locations will be determined during remedial
design and will include at a minimum:
Upper Aquifer: 6 points (4 existing locations, 2 new)
Intermediate Aquifer: 16 points (10 existing locations, 6 new)
Deep Aquifer: 5 points (2 existing locations, 3 new)
Additional sampling will include any residential wells still in use
around the site; surface water and sediment from 4 locations in
McBride Drain; and leachate samples obtained from all holding
tanks. Ambient air monitoring samples will be obtained from the
vicinity of the site (1 upwind and 3 downwind from each site).
Fence; A chainlink fence will be constructed around the entire
site, including the southern border, to prevent access to the site.
The fencing will consist of a minimum six 'foot high chain link
perimeter fence topped with three strand barbed wire. The length
of the fence will be approximately 13,400 feet, and include at a
minimum one double, 12 foot wide, swing gate for controlled access.
Warning signs advising that the area is hazardous will be posted
17
-------
TJ
08
330
oo
/I
•1."
•I
"Jl (n)n'"p •'. T
•vl " • i «
^
ICGOO
FIGURE 5
AIR ANQ
T1*L wfll SAUPIING LOC*:-.'
-------
08
OO
BCn«CC» SiftS » *MO 9*
®
o
HHC PAIBCO UOMtOPiNC
. (SM*UOW/h*ltOMCOI*Tt)
FIGURE 6
SHALLOW. iNICRMCDlATt
»NO DCCP AOUirtB
uoNiioniNG WELL LOCATIONS
ALTOMATIVE 2
SOUIM UACOW0 OlSPOSAl AUTHORITY ytt
rs *lfc*l
-------
at 100 foot intervals along the fence and at the gate.
Land Use and Deed Restrictions: Institutional controls, including
deed restrictions, will be implemented to prohibit future
development of the landfill (including but not limited to, on-site
excavations, construction and drilling) and to prohibit the
installation of drinking water supplies at the facility. The deed
restrictions regarding future development of the landfill and
installation of drinking water supplies will be considered
permanent.
Municipal Water Supply; Individual residences where consumption of
ground water from private wells exceeds a risk level of 1 x 10r6
due to contamination derived from the site, will be attached to the
municipal water supply.
Review of Site Conditions; Site conditions will be re-evaluated
every five years. The reviews will include a detailed analysis of
the long-term monitoring data, a temporal and spatial evaluation of
contaminant migration in various media, the progress of any natural
attenuation, an assessment of current residual health risks, an
evaluation of the effectiveness of the institutional controls, a
discussion that addresses any public comments or complaints
received during the five-year period, and an evaluation relative to
what additional remedial measures, if any, should be implemented
based on the reviewed site conditions.
Current Remedial Actions; Remedial actions currently in effect at
the Site (leachate collection systems, leachate removal, and slurry
wall) will be maintained and operated.
Alternative 3: Ground-water Collection and Treatment
Capital Cost: $ 5,745,000
Annual O&M Costs: 224,000
Present Worth: 9,264,000
Years to Construct: 2 to 3
Alternative 3 includes a modified long-term monitoring program,
ground-water collection and on-site treatment; an extension of the
existing slurry wall, and residential attachment to municipal water
supply. It also includes the land use/deed restrictions and
construction of the chainlink fence described under Alternative 2.
Figure 7 illustrates the components of Alternative 3.
Long-term Monitoring Program; Long-term monitoring of ground
water, residential wells, surface water and sediment of McBride
Drain, leachate, and air will be performed twice a year for a
minimum of 30 years. All samples with the exception of air samples
will be analyzed for organic and inorganic contaminants on the TCL
and TAL, with the exception of pesticides/PCBs. At the end of 30
years EPA will determine the need for additional monitoring.
18
-------
mHo not JUBHIAM
SUUP PUUPS AND txniACTiON «cu.
PUUPS ««ii IK KIO «•
HCAOCR nPC AT CLOSCST
UONC ronutnii or OTHU
sit
it UMTS or
uuuxvu. lANonu
KBRIS
SUUP AND
(TJUP LOCATXW
«•
MAOCII m ro
TDtATUtNl rAOUTY
McBMDC DRAIN
«• nAucm oncHAHct UNC ran
tmucMt rnou mtAntMT rAcuiv
TO 'OHO* PATH or 4* DIAWTD)
HCAOCn «Pt THOI CONIWUl TO
MceoiDC DRAM
ALTERNATIVE NO. 3 PLAM
CBOONOWATER PUMP AND TREAT
SOUTH lucoui DrsrosAi AUTHOMITT art
rs KPOTII
-------
1. Ground water
The ground-water monitoring program for Alternative 3 is a
modified version of the program discussed under Alternative 2.
The ground-water monitoring program will be designed to detect
increases or decreases in the chemical concentrations of the
ground water at and adjacent to the site. Ground-water
monitoring will include laboratory analysis of samples from
existing monitoring wells, residential wells available for
sampling or still in use, and new monitoring wells. The
number and placement of additional monitoring wells will be
determined during the pre-design phase and will include at;^,a
minimum: 3 monitoring wells to be installed off-site on the
east side of the site, 2 north of MW 118 and one south of MW
118; 4 south of the site, adjacent to McBride Drain; and 4
background monitoring wells. The monitoring wells will be
screened in the intermediate aquifer. An adequate number of
monitoring wells will be placed to the north of the site to
further delineate the extent of the contaminant plume.
2. Surface Water/Sediment Monitoring of McBride Drain
Samples will be collected upstream, adjacent to, and
downstream of the site, and analyzed for the same parameters
as ground-water samples.
3. Air Monitoring
Air samples will be obtained from the vicinity of the site, a
minimum of 1 upwind and 3 downwind from each site, and
analyzed for volatilized contaminants. The monitoring is
intended to detect increases in the level of VOCs at the site.
A gas collection system may be installed if air monitoring
indicates air quality standards are being exceeded due to site
related contamination.
Ground-water Extraction/Collection System
The ground-water extraction system will consist of, at a minimum 1)
8 extraction wells in the intermediate aquifer along the southern
boundary of the site; and 2) shallow aquifer subsurface drains
along the periphery of the waste deposits in both sites 9 and 9a.
Additional extraction wells will be located as necessary to extract
ground-water contaminants outside the site boundaries. The
extraction wells and drains will collect leachate that will then
drain by gravity to a series of strategically placed collection
sumps from which it can be pumped to the treatment plant. The
extraction wells will be designed to pump sufficient quantities of
ground water to capture and extract the entire contaminant plume.
The number of extraction wells required and the estimated total
gallons per minute (gpm) necessary to capture the contamination
plume(s) will be determined during the design phase and will
19
-------
require a pilot test of the proposed system. Extracted ground
water will be piped to the ground-water treatment system for
removal of chemicals to their discharge clean up standards prior to
the discharge to the McBride Drain. The extraction/collection
system will operate until the ground-water cleanup standards are
met. The system described in this paragraph may be modified in
design and will reflect the results of a predesign investigation
that will further delineate the extent of the contaminated plume.
Ground-water Treatment System
The on-site ground-water treatment system, shown in Figure 8, will
consist of multiple process options capable of treating an aqueous
waste stream containing VOCs, SVOCs, and inorganic compounds. Tlie
components of the system and target contaminants are as follows:
TREATMENT SYSTEMS TARGET COMPOUNDS .
Air stripping - most VOCs and some SVOCs
Granular Activated Carbon - remaining VOCs and SVOCs
Oxidation/Precipitation - inorganic compounds
Granular Media Filtration - remaining suspended solids.
The treatment system described above will be pilot tested during
remedial design, at which point it may be modified; its subsequent
performance will be monitored on a regular basis. The system will
be adjusted, i.e. installation of additional ground-water
extraction wells and/or increased pumping rates as warranted by the
performance data collected during operation.
Cleanup Standards
Ground water will be treated until Federal Maximum Contaminant
Levels (MCLs) or non-zero Maximum Contaminant Level Goals (MCLGs),
promulgated under the Safe Drinking Water Act, and the ground-water
cleanup standards derived under Michigan Act 307, Type A and B
criteria are achieved at the point of compliance: the edge of the
landfilled waste. While the cleanup standards can be met at that
point soon after construction of the action is complete, the
cleanup standards will not be met under the site, and it is
anticipated that the system will operate perpetually. (See Table
6 for Ground-water Cleanup Standards.)
Effluent from the treatment plant will be discharged to McBride
Drain, in compliance with the substantive requirements of a NPDES
discharge permit under Part 21 of Michigan Act 245.
20
-------
•.••OUNDWATER
'..• IRACTION
•;V.TEM-
MULTI-MEDIA
FILTER
VAPOR TO ATMOSPHERE
OR FURTHER TREATMENT
AIR STRIPPER
r
ACTIVATED
CARBON
AIR
SLUDGE TO DISPOSAL
TREATED
WATER
DISCHARGE
FILTRATE
LEGEND:
UOUIDS
SOUDS
FIGURE 8
GROUNDWATER TREATMENT SCHEMATIC
SOUTH MACOM8 DISPOSAL AUTHORfTY SITE
FS REPORT
-------
Reactivation of the Ground-water Extraction/Treatment System
If ground-water monitoring indicates that the concentration of one
or more of the contaminants has increased above the cleanup
standards after the ground-water extraction system has been
completed or shut down, the ground-water extraction/treatment
system will be reactivated.
Point of Compliance
The point of compliance for the site will be the waste management
boundaries.
i,
Management of Treatment Residuals
Treatment of the contaminated ground-water will result in the
generation of residual sludge containing heavy metals and other
contaminants, as well as spent carbon containing organic
contaminants. The treatment residuals, which will be tested to
determine if they are RCRA hazardous waste, will be disposed of at
an off-site RCRA compliant facility. RCRA hazardous waste
generated will comply with Land Disposal Restrictions.
Slurry Wall Extension
The purpose of the slurry wall extension is to intercept off-site
migration of the contaminant flow and redirect the ground-water
flow toward the collection system. The existing slurry wall along
the north side of site 9 will be extended to include the east side
of site 9 to its juncture with the south boundary, as shown in
Figure 7. The slurry wall, extending from the ground surface
through both the shallow and intermediate aquifers, will be
anchored into the underlying low permeability glacial till; it will
be compatible with the existing structure.
Municipal Water Supply Attachment
Including, but not limited to; all residences currently on 24 Mile
Road adjacent to the site and within one half mile to the east and
west, all residences on the first half mile of Foss Road, and all
residences on Card Road between 23 Mile Road and 24 Mile Road, not
currently attached to the municipal water supply, will be attached.
All residences constructed in the future in the described area will
also be attached. The area of attachment, as shown in Figure 9,
includes the extent of historical and potential ground-water
contamination.
21
-------
,M ,A .;o ~ OUM
21
SOURCE: U.S.G.S. 7.5' topographic wp.
l^ldenburg Quafirenglt Michigan.
Dated 1968 Photorevised 1973 *nd 1980
Scale: 1*-2000-.
LEGEND
MICHIGAN
- ' 'I?
:•< '—'
QUADRANGLE LOCATION
POOR QUALITY
ORIGINAL
2000
SCAUE IN FEET
FIGURE 9
SMDA SITE MAP
«ooo
X X X X X
DESIGNATES BOUNDARIES OF MUNICIPAL WATER ATTACHMENT AREA
-------
Current Remedial Actions
Remedial actions currently in effect at the site (leachate
collection systems, leachate removal, and slurry wall) will
continue to be maintained and operated, and will be incorporated
into the remedial action as much as is practical from an
engineering standpoint.
J. Summary of Comparative Analysis of Alternatives
In accordance with the NCP, the relative performance of eadh
alternative is evaluated using the nine criteria (40 CFR 300.430)
(e) (9) (iii)), as a basis of comparison. This evaluation
determines the most protective and cost-effective alternative that
will meet the cleanup objectives for the site. The nine criteria
are as follows:
Threshold Criteria
1. Overall Protection of Human Health and the Environment
Overall protection of human health and the environment addresses
whether or not a remedy provides adequate protection and describes
how risks posed by each exposure pathway are eliminated, reduced,
or controlled through treatment, engineering controls/ or
institutional controls.
The primary risks at the site are due to contaminated ground water.
Potential routes of exposure are ingestion, inhalation, and dermal
absorption. Alternative 3 provides overall protection of human
health and the environment by taking active measures to prevent
exposure to the contaminants at the site. These active measures
include collection and on-site treatment of leachate and
contaminated ground water. The ground water collection/extraction
system and slurry wall will prevent off-site migration of the
contaminant plume and direct contaminated ground water to the
treatment system. Cleanup standards for ground water, see Table 6,
will be met at the waste boundary.
Alternative 1 (No Action) and Alternative 2 (fencing, institutional
controls, and environmental monitoring) do not provide adequate
protection to human health and the environment from exposure to the
contaminants present in the ground water. Institutional controls
are often difficult to enforce and do not reduce the risks to the
environment. Monitoring would provide notice but not prevent the
contaminant plume from migrating off-site, at which time additional
measures would be taken.
22
-------
2. Compliance with ARARs
This criterion evaluates whether an alternative meets applicable or
relevant and appropriate requirements (ARARs) of other State and
Federal environmental statutes and/or provide grounds for invoking
a waiver.
The major ground water ARARs include the requirements of the
Federal Safe Drinking Water Act, the State Safe Drinking Water Act
(Act 399), Act 245 of 1929 (as amended), and the State
Environmental Response Act (Act 307).
'*
Alternative 3 will be designed and implemented to comply with
ground-water cleanup standards at the point of compliance, the
waste boundaries. The cleanup standards for contaminated ground
water at the site are Michigan Act 307 Type A and B standards,
which treat each contaminant to the 1 x 10-6 level (or background
or limits of detection), and Federal standards, as shown in Table
6. All effluent discharges from the treatment system will comply
with the substantive requirements of a National Pollution Discharge
Elimination System (NPDES) permit under the Clean Water Act (CWA).
RCRA waste generation and temporary storage regulations under 40
CFR Part 262 and Land Disposal Restrictions (LDR or Land Ban) under
40 CFR Part 268, are applicable to residuals from the ground-water
treatment system if they contain RCRA hazardous waste. Residuals
will be tested for the presence of RCRA hazardous waste. If
present, waste will be treated to meet LDRs before being disposed
of at an off-site RCRA compliant treatment facility.
Wetland and flood plain requirements: construction activities at
the site will be designed to limit impact on adjacent wetlands and
the McBride Drain floodplain. Impacts include wetland hydrology
changes due to excavation, drain fields and filling activities. A
preliminary ecological assessment has been performed. Additional
studies would be performed during preliminary design.
Alternatives 1 and 2 will not meet requirements for the remediation
of contaminated ground water of Michigan Act 307 since no active
measures for ground-water remediation would be initiated.
ARARs are discussed in greater detail in Section L.2. Statutory
Determinations.
Primary Balancing Criteria
3. Lona-Term Effectiveness and Permanence
This criterion refers to the ability of a remedy to maintain
reliable protection of human health and the environment over time,
once cleanup goals have been met.
23
-------
Alternative 3 would construct a ground-water collection and
treatment system that would operative perpetually, or until ground-
water cleanup standards are met. The ground-water collection
system and slurry wall extension will prevent off-site migration of
the contaminant plume.
Alternative 2 provides little long-term effectiveness and
permanence as it relies on institutional controls and monitoring to
reduce risks at the site. Alternatives 1 and 2 provide no response
action and thus no long-term effectiveness.
4. Reduction of Toxicity. Mobility, or Volume through
Treatment ..
This criterion evaluates treatment technology performance in the
reduction of chemical toxicity, mobility, or volume.
Alternative 3 treats the contaminants in the leachate and ground
water in an on-site water treatment plant. Treatment of the
contaminants would result in a significant reduction of contaminant
toxicity through the treatment process and satisfy the statutory
preference for treatment as the principal element of the remedy.
The on-site ground-water treatment system consists of multiple
process options, including air stripping, granular activated
carbon, oxidation/precipitation, and granular media filtration,
capable of treating an aqueous waste stream containing VOCs, SVOCs,
and inorganic compounds. The treatment process will result in the
generation of residual sludge containing heavy metals and other
contaminants, as well as spent carbon containing organic
contaminants. The treatment residuals will be tested to determine
if they are RCRA characteristic and, if so, will be treated to
comply with LDRs before being disposed of at an off-site RCRA
compliant facility.
Alternatives 1 and 2 do not use treatment.
5. Short-Term Effectiveness
Short-term effectiveness considers the time to reach cleanup
objectives and the risks an alternative may pose to site workers,
the community, and the environment during remedy implementation.
This criterion also considers the reliability and effectiveness of
any mitigative measures taken during remedy implementation to
control those short-term risks.
All of the alternatives, except Alternative 1, are considered
effective in the short term, as certain aspects of the
alternatives, such as institutional controls and monitoring would
be implemented within a year. The construction components of
Alternative 3 Would require 2 to 3 years to complete. The ground-
water collection and treatment system, however, may operate
24
-------
perpetually.
The potential for worker exposure to contaminated materials, dust,
and vapors exists for all alternatives except Alternative 1. The
potential for exposure increases as the amount of activity at the
waste disposal area increases. Health risks to workers would be
minimized with routine use of protective equipment.
Construction of the slurry wall in Alternative 3 involves
excavation of waste and transportation of construction materials.
These activities could pose a temporary health risk to the
community because of the potential for inhaling wind-blown dust and
increased truck traffic in the area of the site. This potential
would be minimized as much as possible through good construction
practices and engineering controls.
6. Implementability
This criterion considers the technical and administrative
feasibility of a remedy, including the availability of materials
and services needed to implement and/or construct the remedy.
No major implementability problems are anticipated for any of the
alternatives. The technologies included in each alternative are
readily available and easily implemented. Alternative 2 would
appear to be the easiest to implement, since it would require only
an environmental monitoring system and institutional controls.
Institutional controls, which may include deed restrictions and
access agreements are, however, often difficult to obtain and
implement. Alternative 3 treats ground water and would require
pilot studies to ensure the proper performance of the collection
and treatment system.
7. Cost
Estimated cost includes estimated capital, operation and
maintenance, and present net worth costs.
The estimated costs for remedial action alternatives, listed in the
following table, are order-of-magnitude estimates with an intended
accuracy range of +50 percent and -30 percent for the identified
alternative. The estimated cost of the selected alternative will
be further refined in the final design. Capital costs are the
direct and indirect costs required to initiate and install a
remedial action. Annual operation and maintenance cost (O&M)
includes the annual operating cost for a remedial action incurred
and paid on a yearly basis following implementation of the remedial
action. Present worth analysis provides a method for evaluating
and comparing costs that occur over different tijne periods by
discounting future expenditures to the present year.
25
-------
Alternative
1
2
3
Table 7
Capital Cost
$ -0-
427,000
5,745,000
O&M Cost
$ -0-
109,000
224,000
Present Worth
$ -0-
2,192,000
9,264,000
Modifying Criteria
8. State Acceptance
'*
Cf
The State of Michigan concurs with the ROD.
9. Community Acceptance
Community acceptance of the preferred alternative is described in
the Responsiveness Summary attached to this ROD.
K. Selected Remedy
As provided in CERCLA -and the NCP, and based upon the evaluation of
the RI/FS and the nine criteria, EPA has selected Alternative 3 as
the method providing overall effectiveness proportional to its
costs to adequately protect human health and the environment
against exposures to hazardous substances at SMDA sites 9 and 9a.
The selected remedy, Alternative 3, includes long-term monitoring,
ground-water collection and on-site treatment; an extension of the
existing slurry wall; residential attachment to municipal water
supply, and access restrictions. It requires 2 to 3 years to
construct. Alternative 3 is discussed in more detail in Section I.
The components of the selected remedy are as follows:
1. Long-term Monitoring
Long-term monitoring of ground water, residential wells,
surface water and sediment of McBride Drain, leachate, and air
will be performed twice a year for a minimum of 30 years.
With the exception of air samples, samples will be analyzed
for all compounds on the TCL and TAL as described in Section
I. Air samples will be analyzed for VOCs only. At the end of
30 years EPA will determine the need for additional
monitoring.
2. Ground-water Extraction/Collection System
Ground-water extraction wells will be installed in
the intermediate aquifer as necessary to extract ground-water
contaminants associated with the site. Shallow aquifer
subsurface drains will be constructed along the periphery of
26
-------
the waste deposits in both sites 9 and 9a. The purpose of the
extraction wells is to capture and extract the entire
contaminant plume. The extraction wells and drains will
collect leachate in a series of collection sumps from which it
will be transported to the on-site ground-water treatment
system.
The extraction/collection system will operate until the
aquifer ground-water cleanup standards are achieved at the
point of compliance: the edge of the landfilled waste. While
the cleanup standards can be met at that point soon after
construction of the action is complete, the cleanup standards
will not be met under the site and it is anticipated that the
system will operate perpetually.
3. On-site Ground-water Treatment System
The on-site ground-water treatment system will consist of
multiple process options capable of treating an aqueous waste
stream containing VOCs, SVOCs, and inorganic compounds to
their discharge cleanup standards prior to discharge to the
McBride Drain. The treatment residuals, which will be tested
to determine if they are Resource Conservation and Recovery
Act (RCRA) hazardous waste, will be disposed of at an off-site
RCRA compliant facility. Any RCRA hazardous waste generated
will be treated to comply with Land Disposal Restrictions.
4. Slurry Wall Extension
The purpose of the slurry wall extension which will be
constructed along the east side of site 9, is to intercept
off-site migration of the contaminant flow and redirect the
flow toward the collection system. The slurry wall extension
will be attached to, and compatible with, the existing slurry
wall along the north side of site 9.
5. Municipal Water Supply Attachment
All residences within a one half mile radius of the site that
are not currently attached to the municipal water supply will
be attached.
6. Access Restrictions
a. Institutional controls that will be instituted may
include deed restrictions to limit access and
prevent future development of the landfill, and
ground-water use restrictions.
b. Permanent fences will be constructed and maintained
around the entire site and treatment systems to
prevent exposure to site contaminants and provide
27
-------
security for the remedial action equipment.
7. Cost Summary
Capital Cost: $ 5,745,000
Annual O&M Costs: 224,000
Present Worth: 9,264,000
8. Other Provisions
Mitigative measures will be taken during remedy construction
activities to minimize the impacts of noise, dust, smell, and
erosion run-off to the surrounding community and environs.
Fugitive dust emissions will not violate the National Ambient
Air Quality Standard for particulate matter smaller that 10
microns (PM-10). Potential runoff, silting and sedimentation
problems from construction will be mitigated to comply with MI
Acts including Acts 203 (1979), 346 (1972) and 347 (1972) for
wetland protection, inland lakes and streams, and soil erosion
and sedimentation control, respectively.
The selected remedy will achieve substantial risk reduction through
extraction of the leachate and contaminated ground water and
treatment to health-based levels. The ground-water treatment
operable unit meets the remediation goals for cleanup of the ground
water outlined in the FS.
L. Statutory Determinations
The selected remedy must satisfy the requirements of section 121(a-
e) of CERCLA to:
1. Protect human health and the environment;
2. Comply with ARARs or justify a waiver;
3. Be cost effective;
4. Utilize permanent solutions and alternative treatment
technologies or resource recovery technologies to the
maximum extent practicable; and
5. Satisfy a preference for treatment as a principal element
of the remedy.
The implementation of Alternative 3 at the SMDA sites 9 and 9a
satisfies the requirements of CERCLA as detailed below:
1. Protection of Human Health and the Environment
Implementation of the selected alternative will reduce and
control potential risks to.human health posed by exposure to
contaminated ground water. Extraction and treatment of
contaminated ground water to meet ground-water cleanup
standards will reduce the potential excess lifetime cancer
28
-------
risk due to ingestion of contaminated ground water from the
unacceptable risks currently posed (e.g., 2.0 x 10'3 ) by
ground water contaminants to a maximum risk for individual
carcinogenic chemicals of approximately 1 x 10~*. As above,
assuming that all carcinogens were only treated to the 1 x 10"6
level, the maximum cumulative risk would be approximately 1 x
10"5, which is an acceptable level. The Hazard Index would be
reduced to 1.0, which is also an acceptable level. Extracting
ground water in the vicinity of the landfills will lower the
water table of the shallow and intermediate aquifers to below
the level of the landfilled waste to the maximum extent
practicable, thus minimizing the production of leachate by
ground water flowing laterally through the waste. \
Access restrictions will prevent direct contact with
contaminated ground water until the ground-water cleanup
standards are met. The selected remedy also protects the
environment by reducing the potential risks posed by site
chemicals discharging to the surface water (McBride Drain).
No unacceptable short-term risks will be caused by
implementation of the remedy. The community and site workers
may be exposed to noise and dust nuisances during installation
of extraction/monitoring wells and construction of the slurry
wall. Mitigative measures will be taken during remedy
construction activities to minimize impacts of construction
upon the surrounding community. The chances of vehicular
accidents may rise due to the projected increase in the volume
of truck traffic in hauling construction materials to the
landfill. Standard safety programs should manage any short-
term risk of accidents. The air stripping treatment component
will be designed and monitored so as to not result in short-
term risks due to VOC air emissions. Treatment residuals will
be managed in accordance with LDRs.
2. Compliance with ARARs
The selected remedy will comply with the Federal and/or State,
where more stringent, applicable or relevant and appropriate
requirements (ARARs) listed below:
a. Chemical-specific ARARs
Chemical-specific ARARs regulate the release to the
environment of specific substances having certain
chemical characteristics. Chemical-specific ARARs
typically determine the extent of clean-up at a site.
i. Ground Water
Federal ARARs
29
-------
Maximum contaminant levels (MCLs) and, to a certain
extent, non-zero maximum contaminant level goals
(MCLGs), the Federal drinking-water standards
promulgated under the Safe Drinking Water Act
(SDWA), are applicable to municipal water supplies
servicing 25 or more people. At SMDA sites 9 and
9a, MCLs and MCLGs are not applicable but are
relevant and appropriate since the upper and
intermediate aquifers are Class II sources which
could potentially be used as a source of drinking
water in the area of concern, and contaminants from
the two aquifers could potentially contaminate the
deep aquifer that is being used as a source of
drinking water. MCLGs are relevant and appropriate
when the standard is set at a level greater than
zero (for non-carcinogens), otherwise, MCLs are-
relevant and appropriate. The point of compliance
for Federal drinking-water standards is at the
boundary of the landfilled wastes.
State ARARs
The substantive provisions of Parts 6 and 7 of
Michigan Act 307 and Rule 57 of Act 245 are
applicable or relevant and appropriate to the SMDA
sites 9 and 9a. EPA has determined that acceptable
standards for ground water clean-up, that have been
derived under Type A and B criteria, would be
protective in all the areas of the plume outside of
the landfilled waste. Clean-up levels derived
under Type A and B criteria would allow the aquifer
to be restored to its beneficial uses by achieving
the risk-based clean-up standards. EPA has
determined that these clean-up standards are
protective of human health and the environment.
The point of compliance for these standards is at
the boundary of the landfilled waste.
EPA has determined that Type A and B criteria would
yield ground-water clean-up standards which would
also provide for the protection of surface water
quality, in turn protecting human health and the
environment.
ii. Surface Water
Federal ARARs
Surface water quality standards for the protection
of human health and aquatic life were developed
under Section 304 of the Clean Water Act (CWA) .
The Federal Ambient Water Quality Criteria (AWQC)
30
-------
are nonenforceable guidelines that set pollutant
concentration limits to, protect surface waters that
are applicable to point source discharges, such as
from industrial or municipal wastewater streams.
At a Superfund site, the Federal AWQC would not be
applicable except for pretreatment requirements for
discharge of treated water to a Publicly Owned
Treatment Works (POTW). CERCLA (section 121(d)(l))
requires EPA to consider whether AWQC would be
relevant and appropriate under the circumstances of
a release or threatened release, depending on the
designated or potential use of ground water or
surface water, the environmental media affected by
the releases or potential releases, and the latest
information available. Since the contaminated
aquifer is a potential source of drinking water and
since treated water may be discharged to McBride
Drain, AWQC adopted for drinking water and AWQC for
protection of freshwater aquatic organisms are
relevant and appropriate to the point source
discharge of the treated water into McBride Drain.
State ARARs
Portions of the Water Resources Commission Act 245
(Michigan Act 245) of 1929, as amended, establish
surface water-quality standards to protect human
health and the environment. The State administers
the NPDES program under Part 21 of Michigan Act
245; therefore, Part 21 of Act 245 would be
applicable to the direct discharge of treated water
to McBride Drain, to the indirect discharge through
ground water movement to a surface water body, or
to a discharge to a POTW.
b. Location-specific ARARs
Location-specific ARARs are those requirements that relate to
the geographical position of a site. These include:
Federal ARARs
Executive Order 11988 - Protection of Flood Plains - are
relevant and appropriate for this site. This order
would require that the leachate and ground-water
treatment system be located above 100-year flood plain
elevation and be protected from erosional damage. The
landfills are not currently in a 100-year floodplain.
However, any portion of the remedy that is constructed
within the 100-year flood plain must be adequately
protected against a 100-year flood event.
31
-------
Section 404 of the CWA regulates the discharge of dredged
or fill material to waters of the United States.
Activities during the remedy may be regulated under
section 404 of the CWA; therefore, the substantive
requirements of section 404 would be relevant and
appropriate to the remedial action at the site.
Executive Order 11990 - Protection of Wetlands - is an
applicable requirement to protect against the loss or
degradation of wetlands. Remedial activities may pose a
threat to wetland areas on the south side of site 9.
These threats include drawdown from the ground-water
extraction system as well as siltation and sedimentation
from construction. While a preliminary ecological
assessment has been performed, the scope of the impact
will be determined during design. Mitigative efforts
will be applied to the clean-up if an impact is seen on
wetlands.
State ARARs
The Goemaere-Anderson Wetland Protection Act 203 of 1979
(Act 203) regulates any activity which may take place
within wetlands in the State of Michigan. Act 203 is
relevant and appropriate to the remedial action at SMDA
sites 9 and 9a; it may also require the replacement of
adversely impacted wetlands with comparable resources.
The Inland Lakes and Streams Act 346 of 1972, as amended,
regulates inland lakes and streams in the State. Act 346
would be applicable to any dredging or filling activity
on McBride Drain bottomlands.
The Soil Erosion and Sedimentation Control Act 347 of
1972 regulates earth changes, including cut and fill
activities, which may contribute to soil erosion and
sedimentation of surface waters of the State. Act 347
would apply to any such activity where more than 1 acre
of land is affected or the regulated action occurs within
500 feet of a lake or stream. Act 347 would be
applicable to the ground-water extraction system and
slurry wall construction activities since these actions
could impact McBride Drain, which is less than 500 feet
from the landfill area.
c. Action-specific ARARs
Action-specific ARARs are requirements that define acceptable
treatment and disposal procedures for hazardous substances.
Federal ARARs
32
-------
Since the SMDA landfills closed prior to November 1980,
RCRA Subtitle C requirements are not applicable unless
RCRA-listed or characteristic hazardous wastes are
excavated and managed (treated, disposed, or stored), as
defined by RCRA, during cleanup. RCRA Land Disposal
Restrictions (LDR or Land Ban) would not be applicable
since no "placement" of RCRA hazardous waste would be
occurring at this site.
The selected remedy will store and dispose of hazardous
waste when the ground-water treatment system is in
operation. The contaminated ground water collected wi^Ll
be stored at the treatment facility while awaiting
treatment. The treatment processes will result in the
generation of residual sludge containing heavy metals and
other contaminants, as well as spent carbon containing
organic contaminants. The RCRA waste generation and
temporary storage regulations under 40 CFR Part 262 would
then be applicable to that action. Treatment residuals
will be disposed of at an off-site RCRA compliant
facility.
State ARARs
The State of Michigan administers RCRA within the State.
Under Hazardous Waste Management Act 64 of 1979, as
amended, the State regulates the generation, transport,
treatment, storage, and disposal of hazardous waste. Act
64 would be applicable to the storage/treatment/transport
of hazardous residuals from the on-site treatment
facility.
Parts 4, 9, and 21 of the Water Resources Commission Act
245 of 1929, as amended, establish rules for water
quality by prohibiting injurious discharges to surface
water. These rules would be applicable to the discharge
of treated ground water to McBride Drain.
As described earlier in this document, the Michigan
Environmental Response Act 307 of 1982, as amended (Act
307), provides for the identification, risk assessment,
and evaluation of contaminated sites within the State.
EPA has determined that the substantive provisions of
Parts 6 and 7 of Act 307 are applicable or relevant and
appropriate to SMDA sites 9 and 9a. The Act 307 rules
require that remedial actions shall be protective of
human health, safety, the environment, and the natural
resources of the State. To achieve this standard of
protectiveness, the Act 307 rules require that a remedial
action achieves a degree of clean-up under either Type A
(clean-up to background levels), Type E (clean-up to
risk-based levels), or Type C (clean-up to risk-based
33
-------
levels under site-specific considerations) criteria. EPA
has determined that the Type A and B criteria are
appropriate for the ground-water operable unit. The
point of compliance for clean-up standards is at the
boundary of the landfilled waste.
3. Cost-effectiveness
Cost-effectiveness compares the effectiveness of an
alternative in proportion to its cost of providing its
environmental benefits. Table 7 under Section J. 7. lists the
costs associated with the implementation of the remedies.
I,
• if
Alternative 1 (No Action) has no cost and no benefit.
Alternative 2, (environmental monitoring), is the least
expensive of the two alternatives that involve action.
However, it does not provide adequate protection of human
health and the environment, meet ARARs, or provide
effectiveness over the long term.
The selected alternative (Alternative 3) is considered the
most cost-effective way to achieve remediation standards
quickly, thereby protecting human health and the environment,
provide long-term effectiveness, and meet ARARs.
4. Utilization of Permanent Solutions and Alternative
Treatment Technologies or Resource Recovery Technologies to
the Maximum Extent Practicable
The selected remedy represents the maximum extent to which
permanent solutions and treatment technologies can be utilized
in a cost-effective manner for this site. Of those
alternatives that are protective of human health and the
environment and comply with ARARs, EPA has determined that the
selected remedy provides the best balance of tradeoffs in
terms of long-term effectiveness and permanence, reduction in
toxicity , mobility, or volume achieved through treatment,
short-term effectiveness, implementability, cost, and
considering State and community acceptance.
The NCP gives priority to long-term effectiveness and
reduction of toxicity, mobility or volume at a site, stating
that these two criteria are generally the key decisional
factors to be considered at Superfund sites once the threshold
criteria of protectiveness and compliance with ARARs is
satisfied. The key criterion used in remedy selection for
SMDA sites 9 and 9a was immediate reduction of toxicity
through treatment. Short-term and long-term effectiveness
were also emphasized in that the selected remedy will prevent
off-site migration of the contaminant plume.
34
-------
The selected remedy will significantly reduce the inherent
hazards posed by the contaminated ground water and leachate by
collecting and treating these contaminants. The slurry wall
extension and extraction wells will prevent of f-site migration
of the plume of contamination. These benefits are achieved
quickly and at a reasonable cost. Contaminants from the
ground water are extracted and permanently addressed through
treatment.
The State of Michigan has (concurred) with the remedy.
Community acceptance is addressed in the responsiveness
summary attached to the ROD.
>*
5. Preference for Treatment as a Principal Element ""
The selected remedy for the first operable unit satisfies the
statutory preference for treatment as a principal element
through treatment of the contaminants in the leachate and
ground water in an on-site ground-water treatment plant.
Treatment of the contaminants would result in a significant
reduction of contaminant toxicity through the treatment
process. Residuals generated by the multiple process
treatment system, which could include residual sludge
containing heavy metals and spent carbon containing organic
contaminants, will be treated if necessary to comply with
LDRs, before being disposed of at an off-site RCRA compliant
facility.
35
-------
RESPONSIVENESS SUMMARY
This Responsiveness Summary has been prepared to meet the
requirements of Sections 113(k)(2)(B)(iv) and 117(b) of the
Comprehensive Environmental Response, Compensation, and Liability
Act of 1980, as amended by the Superfund Amendments and
Reauthorization Act of 1986 (CERCLA), which requires the United
States Environmental Protection Agency (EPA) to respond "...to each
of the significant comments, criticisms, and new data submitted in
written or oral presentations" on a proposed plan for remedial
action. This Responsiveness Summary addresses concerns expressed.
by the public and the potentially responsible parties (PRPs) in the
written and oral comments received by EPA regarding the proposed
remedy for the South Macomb Disposal Authority (SMDA) Landfill
site.
A. OVERVIEW
I. BACKGROUND/PROPOSED PLAN
The 159-acre SMDA site, located 30 miles northeast of
Detroit in Macomb County, Michigan, consists of two
adjacent former municipal landfills, sites 9 and 9a. The
159-acre landfill is located in a generally
rural/agricultural area. The Remedial Investigation
identified two areas of concern at the site: the
contaminated ground water under the site, and the source
of the contamination, the landfill contents.
The remedial alternative selected for the SMDA site,
Alternative 3, is an operable unit that addresses the
contaminated ground water. An operable unit is a
discrete action that comprises an incremental step toward
the final remedy; it is an integral part of a more
comprehensive action that will be taken at the site.
This operable unit addresses the contaminated ground
water at the site. The nature of a second operable unit
to address the landfill contents will be assessed during
the performance of the first operable unit. The Proposed
Plan for remedial action included the following:
• Extraction and treatment of the groundwater
contaminant plume, with discharge of the treated
water to adjacent McBride Drain;
• Construction of a slurry wall;
• Environmental monitoring; and
• Connection of nearby residents to the local
municipal water supply.
-------
II. PUBLIC COMMENT PERIOD
A public comment period was held from May 1, 1991 to June
6, 1991, to allow interested parties to comment on the
proposed plan, in accordance with Section 117 of CERCLA.
On May 6, 1991, a public meeting was held at the Senior
Activities Center in Mt. Clemens, Michigan at which EPA
presented the proposed plan, answered questions, and
accepted comments from the public. During the comment
period, EPA received approximately 3 written comments and
1 verbal comment concerning the Proposed Plan.
B. COMMUNITY INVOLVEMENT k
The level of public interest regarding the site has been
high since the controversial siting of site 9 in 1968.
Community concern heightened when leachate outbreaks were
observed in 1971 and continued on into the 1980s. The
leachate outbreaks resulted in contamination of McBride
Drain and a number of residential drinking water wells,
whereupon local residents brought suit against SMDA and
* the State of Michigan in 1983. The State of Michigan
joined the residents in their suit in 1984. This case
was decided in favor of the plaintiffs in April 1991.
The judge's decision requires SMDA to undertake a
comprehensive remedial action plan at the site that
includes a cap, slurry wall, and ground-water treatment.
Several key areas of community concern in regard to the
preferred remedy in the Proposed Plan are as follows:
• The remedy proposed is not as comprehensive as it
should be; i.e., it should include the slurry wall
and cap required in the judge's decision;
• The remedy should be implemented as soon as
possible, as the community has already waited so
long for something to be done; and
• The proposed construction activity may have an
adverse impact on the community due to increased
traffic, noise, and dust levels in the residential
areas in the vicinity of the site. In addition,
excavation of the waste, and operation of the
ground-water treatment plant may produce unpleasant
odors.
The above concerns have been addressed in the following
section.
-------
C. SUMMARY OF SIGNIFICANT COMMENTS
The public comments regarding the SMDA site are organized into the
following categories:
• Summary of comments from the local community
regarding the proposed plan;
• Summary of comments from PRPs concerning the
Remedial Investigation (RI), Feasibility Study (FS)
and the proposed plan.
I.
Many of the comments below have been paraphrased in order to
effectively summarize them in this document. The reader is
referred to the public meeting transcript and the written comments
submitted during the public comment, which are available in the
Information Repository located at the Macomb County Public Library.
I. SUMMARY OF SIGNIFICANT COMMUNITY COMMENTS
Most comments received from the community were taken at the
public meeting. These ranged from support for the preferred
alternative (Alternative 3) , as long as it is not the final
remedy and requests that the EPA stay involved, to outrage
that EPA is not proposing a more comprehensive remedy or
subordinating its process to the judge's ruling in State
court. Several commenters reiterated concerns expressed at
previous meetings rather than supporting or opposing any
particular remedy. Comments received from the community are
listed below:
Comment 1
Several commenters requested that cleanup begin as soon as
possible, asserting that negotiations would delay the start of the
project.
Response 1
EPA is working to ensure that the project proceeds as quickly as
possible. However, whenever practicable and in the public
interest, the EPA is required under Section 122 of CERCLA to
negotiate with the PRPs to have them conduct and fund the cleanup
before expending public funds from the Superfund. At this time, no
condition at the site has been identified which would demonstrate
that the additional time required for negotiations would be
detrimental to the public interest, and thus warrant use of the
Superfund. PRPs have indicated interest in conducting the remedial
design/remedial action (RD/RA) and should then be afforded the
opportunity to negotiate. However, should negotiations fail to
achieve an agreement, the PRPs could be ordered to conduct the
RD/RA under Section 106 of CERCLA or the EPA could conduct the
-------
action using the Superfund trust fund.
Comment 2
Residents in the immediate vicinity of the site expressed concerns
about noise, dust, traffic and odors emanating from the excavated
waste during the construction phase of the remedial action. One
resident was also concerned about smells from the treatment plant.
Response 2
EPA agrees that noise, dust, traffic, and odor contrpl
considerations are a high priority during construction of the
remedy and afterwards during operation. During the design phase of
the project, EPA will determine the most effective ways to control
traffic, dust, and construction noise around the site to ensure the
health and safety of area residents. This determination will
include discussions and meetings with the community prior to any
actions occurring at the site as well as during the activities. It
will require on-going communication and cooperation between the
community and EPA.
Possible solutions may include scheduling truck traffic for
specific hours and limiting the number of trucks; spraying work
areas and roads with water to keep down dust; use of barriers and
suppressants to limit dust and odors; as well as scheduling certain
types of work such as excavation of waste for the colder months of
the year. The treatment plant itself would not emit odors as it
will be enclosed.
Comment 3
While some commenters said EPA was "our only hope," others wanted
to know why they couldn't say "thanks for coming but we don't need
you anymore" (since the judge's decision was so comprehensive).
Several commenters wanted to know why "EPA doesn't just subordinate
to the judge" or write a proposed plan that "incorporates the
judge's remedy." Two commenters expressed concerns that the
cleanup plan selected by EPA and the action ordered by Judge
.Balkwill will interfere with each other.
Response 3
Once a site is placed on the National Priorities List (NPL) and
becomes a Superfund site, the legal processes required by CERCLA
must be completed. This includes a determination of the nature and
extent of contamination, evaluation and selection of cleanup
alternatives according to the evaluation criteria discussed in the
National Contingency Plan (NCP), followed by cleanup of the site
and eventual delisting (removal of the site from the NPL) . Any
cleanup alternative proposed or endorsed by EPA must be selected
after being subjected to specific evaluation criteria. These
-------
criteria are discussed in Section J of the ROD.
While the remedy ordered by Judge Balkwill does not appear to
conflict with the ground-water operable unit selected by EPA, EPA
recognizes the potential problem and will strive to coordinate with
the appropriate parties to preclude this conflict from occurring.
Comment 4
One commenter suggested that EPA was "going for the cheapest
remedy" and that EPA was being politically pressured and basing its
decision solely on cost.
f
Response 4
Cost is only one of nine criteria used during the FS to evaluate
remedies to clean up an NPL site. EPA selects the least costly
remedy only when all other evaluation criteria are met. In this
case, EPA's proposed alternative for cleaning up the site is the
most expensive evaluated for this operable unit. EPA has not been
"politically pressured" into proposing its cleanup plan. The
proposed plan is the result of the evaluation criteria discussed in
the FS.
Comment 5
The same commenter wanted to know how EPA "ever got past step 1"
(protection of human health and the environment) with a remedy that
does not "get the garbage out of the ground water."
Response 5
EPA's proposed plan for cleaning up the SMDA site addresses the
greatest threat associated with the site - the contaminants in the
ground water. Section F. of the ROD discusses the results of the
risk assessment. The ground-water operable unit will reduce site-
related risks to health-based levels quickly, and is therefore
protective of human health and the environment. A second operable
unit will address the landfilled waste.
Comment 6
The same commenter stated that "midnight dumping" had taken place
in 1968 and 1969. She wanted to know what method had been used to
look for "barrels" at the site and had a scan been done for nuclear
waste.
Response 6
EPA currently has no information concerning illegal dumping at the
site, but encourages individuals who have such information to
contact Dan O'Riordan, EPA's Community Relations Coordinator, at 1-
-------
800-621-8431. EPA has no evidence indicating that drums or nuclear
waste were disposed of at the site.
Comment 7
The same commenter expressed the opinion that, since the RI
contained the phrases "lack sufficient data, poorly defined,
uncertain, assumed, may and difficult," EPA did not have enough
information to "come up with any kind of conclusion or any kind of
a remedy."
Response 7
it
EPA disagrees with the comment. The purpose of the RI as stated in
the National Contingency Plan (NCP) is to assess site conditions to
the extent necessary to select and implement a remedy in as timely
a mariner as possible in order to protect human health and the
environment. The NCP reflects a bias for action. EPA believes
that, while the remedial investigation does not provide answers to
all questions regarding the nature and extent of contamination, it
was performed to a sufficient level of detail and was sufficiently
comprehensive to determine the need for remedial action and to
evaluate remedial action alternatives. It is part of the
scientific method to both identify that which is not known and to
make assumptions based upon what is known.
Comment 8
One commenter stated that $9.3 million is not acceptable as "a fine
of judgment."
Response 8
A Superfund cleanup is not a punitive action. The cost of the
remedial action is not a fine or penalty. It is the cost to
construct and maintain the cleanup at the SMDA site. The cost is
the same whether the PRPs or Superfund pays for the cleanup.
Comment 10
Several residents present at the public meeting asked how they
could get their wells tested.
Response 10
Residents can call John Hesse, Chief of the Environmental Health
Assessment Division, Michigan Department of Public Health at
517/335-8353.
Comment 11
Residents wanted to know who, under the proposed plan, would be
6
-------
connected to municipal water.
Response 11 ,
Figure 9 in the ROD shows a map of the area that will be included
in the remedial action.
Comment 12
Two commenters wanted to know "how large the aquifers are under the
landfill ... and who is at risk," how far the aquifers extend
beyond the landfill, and which way the ground water flows in the
aquifers.
Response 12
The physical characteristics of the aquifers are discussed in
Sections E.2. and E.5. of the ROD. The risks associated with the
ground water are discussed in Section F.5. of the ROD. The purpose
of the Remedial Investigation was to determine the nature and
extent of contamination at the site. The horizontal extent of the
three aquifers was delineated only as far as was necessary to
ascertain the extent of contamination. However, boring and
monitoring well information indicate that the three aquifers extend
to the north of the site at least 2,000 feet and that the
intermediate and deep aquifers appear to merge just to the south of
McBride drain.
In addition, the preferred plan in the Proposed Plan requires
continual monitoring of the ground water in all three aquifers.
Since ground-water flow is very slow, if any site contaminants
should migrate off-site in the future, they can be detected early
and action taken to prevent risks to residents in the area still
using wells for drinking water.
Comment 13
Several residents expressed appreciation and support for the
remedial action.
Response 13
Acknowledged.
II. SUMMARY OF SIGNIFICANT PRP COMMENTS
The South Macbmb Disposal Authority (SMDA) submitted written
comments on the Proposed Plan through the Detroit law firm of
Dykema Gossett. SMDA determined that the proposed plan is
"unwarranted given the insufficient data upon which this remedy is
-------
based and the minimal risk associated with the groundwater." The
commenter also determined that EPA has "improperly de-emphasized
cost as a factor to be considered in its selection of a remedy,"
and that Alternative 2 would be a more appropriate choice. The
comments are addressed below:
Comment 1
SMDA states that the data upon which the remedy selection is based
is not only inadequate, but is "seriously flawed," particularly the
residential well sampling.
'•
Response 1 ""
EPA disagrees. EPA does not believe more data is required at this
time or that the data is "seriously flawed." The subject of
additional data needs was addressed under Comment/Response 7,
above, which defined the purpose of the RI.
As to the subject of "flawed data," data gathered and analyzed
during a remedial investigation under the Superfund program must
compiy with a Quality Assurance Project Plan (QAPP) which
establishes a high standard of data quality. The data used to
evaluate alternatives at the SMDA site was subjected to QAPP
requirements which also demand that data be validated by EPA's
Central Regional Laboratory. Data that did not meet established
standards were not used in the evaluation.
As discussed under response 7 above, the purpose of the
investigation was to acquire sufficient information of high quality
to make an expeditious decision concerning the most appropriate way
to clean up the site. Data necessary for design purposes of the
remedy, as opposed to remedy selection, can be obtained during the
pre-design or remedial design (RD) phases. This enables EPA to
clean up sites as quickly as possible and avoid the delays
associated with lengthy and costly investigations that are not
specifically necessary for remedy selection.
Comment 2
SMDA states that there is no evidence that ground water from sites
9 and 9a poses a risk to human health or to the environment, and
further, that there is no significant risk to human health because
one of the exposure pathways - residential use of ground water as
a drinking water source - has been or will be eliminated at the
appropriate time as additional residences are or will be connected
to the municipal water supply in the event of future well
contamination.
Response 2
EPA disagrees with the commenters' determination and believes there
8
-------
is significant risk from contaminated ground water at the site.
The commenter is referred to the risk assessment section of the ROD
(Section F).
The SMDA risk assessment seems to be based on the fact that a
municipal water supply has been or will be made available to local
residents. However, the fact that residents are being or will be
connected to a municipal water supply does not thereby eliminate
the human exposure pathway from consideration and permit
contamination of the ground water to continue unchecked. If no
action is taken at the site and, in the future, contamination is
detected in residential wells, it can be assumed that the residents
will have consumed water from the wells before the contamination
was detected. This has occurred in the past and it is unacceptable
that it should happen in the future.
In addition, the NCP states that EPA expects to return usable
ground waters to their beneficial uses, wherever practicable,
within a time frame that is reasonable given the particular
circumstances of the site. Whenever restoration of ground water is
not practicable, EPA expects to prevent further migration of the
plume, prevent exposure to the contaminated ground water, and
evaluate further risk reduction. The goals of this remedial action
are to prevent direct contact with the ground-water contaminants
and off-site migration of the contaminant plume. (40 CFR Section
300.430(a)(1)(iii)(F)).
The NCP also states that the use of institutional controls shall
not substitute for active response measures as the sole remedy
unless such response measures are determined not to be practicable.
(40 CFR Section 300.430(a)(1)(iii)(D)). Active response measures
are practicable in this case.
SMDA also states that its preferred alternative, Alternative 2
(monitoring only), would comply with ARARs. EPA has determined
that Alternative 2 would not meet comply with ARARs and refers the
commenter to the discussion of ARARs in Section J. of the ROD.
Contaminants in the ground water at the site exceed the acceptable
risk range for human health established by EPA, maximum contaminant
levels (MCLs) and Michigan Act 307 standards.
Comment 3
SMDA states that "EPA has improperly de-emphasized cost as a factor
to be considered" in selection of a remedy and questions the cost
effectiveness of the preferred cleanup alternative in that it "may
be only an interim component of a more comprehensive remedy."
Response 3
EPA disagrees. The remedial alternative selected for the SMDA
site, Alternative 3, is an operable unit. The NCP defines operable
-------
units as "discrete actions that comprise incremental steps toward
the final remedy." It is an integral part of a more comprehensive
action that will be taken at the site at a later date and, as such,
will not become obsolete or unnecessary until total site cleanup is
achieved and the ground water beneath the site returned to
beneficial use. Most landfill cleanups include some type of
ground-water remediation and a cap. EPA considers the ground-water
operable unit to be a complete and final remedy for this phase of
the cleanup. A second phase will address the landfill contents.
EPA has determined that the greatest risk to human health and the
environment at the site is ingestion of or contact with the
contaminated ground water. The cleanup goals for this operable
unit are to prevent direct contact with the contaminated ground
water, prevent off-site migration of the contaminants in the ground
water, and remove and treat the .contaminants to health-based
levels. EPA considers the selected alternative (Alternative 3} to
be the most cost-effective way to achieve the cleanup goals
quickly, thereby protecting human health and the environment.
10
-------
Page No. 1
07/25/91
ADMINISTRATIVE RECORD INDEX
REMEDIAL ACTION - UPDATE NO. 1
SOUTH MACOMB DISPOSAL SUPERFUND SITE
MACOHB COUNTY, MICHIGAN
FICHE/FRAME PACES DATE
TITLE
AUTHOR
RECIPIENT
DOCUMENT TYPE
DOCNUMBER
1 00/00/00
Comments regarding
residents near the
South Macomb
Disposal Authority
Landfill
Glen Osanock - Citizen
of Macomb Township, MI
Dan O'RJordan, USEPA Correspondence
2 90/04/21
Summary of Existing
Technical Information
Brenda Tollett,
Dykema Gossett •
(Attorneys for SMDA)
Betty Lavis - USEPA Correspondence
2 91/06/03
Letter re:
The degree of Liability
on South Macomb
Disposal Authority
(SMOA)
Gary Robertson -
Citizen of Warren,
MI
Dan O'Riordan, USEPA Correspondence
25 91/06/05
Letter re:
Enclosure of three
copies of comments
to the EPA's
Proposal Plan for
Remedial Action for
the SMDA Landfill
Superfund Site
Marguerite Gritenas,
Dykema Gossett -
(Attorneys for SMDA)
Dan O'Riordan, USEPA Correspondence
21 90/04/19
Appendix D, Volume II,
Summary of Existing
Technical Information
Available for South
Macomb Disposal
Authority Site 9 I 9A
Contractors for
SMDA
USEPA
Maps
30 91/05/24
Meeting Note re:
Original transcript
of the EPA Public
Hearing in regards
to the South Macomb
Disposal Authority
Landfill Superfund
Site on 5/6/91 with
cover letter
Candace Noblett,
Professional Court
Reporting
Dan O'Riordan, USEPA Meeting Notes
352 87/07/17
Report on Preliminary
Hydrogeotogic
Investigation
Landfills 9 and 9A
Neyer, Tiseo &
Hindo, Ltd.
(Prepared for
SMDA}
USEPA
Report/Studies
-------
Page No. 2
07/25/91
ADMINISTRATIVE RECORD INDEX
REMEDIAL ACTION - UPDATE NO. 1
SOUTH MACOMB DISPOSAL SUPERFUND SITE
MACOMB COUNTY, MICHIGAN
FICHE/FRAME PAGES DATE
HW.E
AUTHOR
RECIPIENT
DOCUMENT TYPE DOCNUM8ER
107 90/04/19
Appendix D, volume 1
to Summary of Existing
Technical Information
Available for South
Macomb Disposal
Authority Sites 9 and
9A
Contractors for
SHDA
USEPA
Report/Studies
286 90/04/19
Appendices A,B,4C
to Sunroary of
Existing Technical
Information Available
for South Macomb
Disposal Authority
Sites 9 and 9A
Contractors for
SHDA
USEPA
Report/Studies
57 90/04/19
Summary of Existing
Technical Information
Available for South
Macomb Disposal
Authority Sites 9 and 9A
Contractors for
SMDA
USEPA
Report/Studies
372 90/08/23
Remedial Investigation
Report • South Macomb
Disposal Authority
Volume I of II
CH2MHILL
USEPA
Report/Studies
878 90/08/23
Remedial Investigation
Report • South Macomb
Disposal Authority
Volume II of II
CH2MHILL
USEPA
Report/Studies
687 90/09/28
Public Comment
Feasibility Study
Report - South Macomb
Disposal Authority
CH2MHILL
USEPA
Report/Studies
9 91/05/00
Proposed Plan for
Remedial Action
USEPA
Reports/Studies
24 91/05/06
South Macomb Disposal
Authority comments to
EPA's proposed plan
for Remedial Action
Ted B. Uahby - SMDA
USEPA
Reports/Studies
-------
, Page No.
07/25/91
ADMINISTRATIVE RECORD INDEX
REMEDIAL ACTION - UPDATE NO. 1
SOUTH MACOMB DISPOSAL SUPERFUND SITE
MACOMB COUNTY, MICHIGAN
F1CHE/FRAME PAGES DATE
TITLE
for the South Macomb
Authority Superfund
Site
AUTHOR
RECIPIENT
DOCUMENT TYPE
DOCNUMBER
-------
Pilt Xo. ' 1
a'(/2l/90
neat/runt fusts cm
rmx
mots urn
soars most msfosm unmi somrm sin
most mm, nuitu
rm
mmm
22 Si/tJ/lt
Docttititttiot
ttcorii
Hr
Btztrt Ittkitg
Sjitn
Settb *Jcoii
Ltodfill It
asm
Othtt
111 8J/fl)/08
leporc on
Sabstrttet
tor tbt Stttb
Ktcoib liiftii
Jotioritf
llDttt tbii
report HI
produced bj
taqinttn tor
tbt ntt]
Itjtt, tiito
t Bitte, Ltd.
5.(ficoi6 Dijpojjl Jeports/Studies 2
iatb.
ISS S2/M/U
22 Hf83/07
leporc on
frtliiittrj
Sfdro/jtologlc
laiestigttitt
(lottt tbii
report vai
produced bj
for
tie Wi]
foteatiil
Vnu Sin
freJliiurr
Jiieiiieac
lerer, fiieo
f ftodo, LID.
S.Stcttb tisftstl ttforts/Sttttiti
Jteport5/5tudie5 4
US
tiatl fort /J«
leiediiJ
Tntibilitj Stodf
m N 10. DJ-5151
cm fill
(TSUI
feportJ/Studiej 5
90/01/12 llteraitirt
Itnj Snort it vi
Soutft Xicnb Ditfilil
lutbotltj
CE2S till
vsm
leportj/Stidiei I
-------
M/ll/SO
mntnm w«s cm
rmt
Stcotb Couotf,
mwsmmi IICOID
sours m0M cufoin uwfiu sotutm sin
mcosi couirr,
MCltlM
-------
lo. 1
01/26/90
UMWt SSIM for tbt Itiitittntin ttctri
som DISPOSE instill svtwm sin
mom comi, maim
mom
ltu:b. Aathoritf
Ltd. Liiittd
USSPk Hailed Stitts
fanrofiKitaJ
Protection
-------
NATURAL RESOURCES COMMISSION
MARLENE J. FLUHARTY
GORDON E GUYER
O. STEWART MYERS
RAYMOND POUPORE JOHN ENGLER. Governor
DEPARTMENT OF NATURAL RESOURCES
STEVENS T MASON BUILDING
P O BOX 300P8
LANSING. Ml 48909
DELBERT RECTOR. O.reclor
September 5, 1991
Mr. Valdas Adamkus, Regional Administrator
U.S. Environmental Protection Agency
Region 5, 5RA-14
230 South Dearborn Street
Chicago, Illinois 60604
Dear Mr. Adamkus:
The Michigan Department of Natural Resources (MDNR), on behalf of the State of
Michigan, has reviewed the Record of Decision (ROD) signed by you on
August 13, 1991, for the groundwater operable unit at the South Macomb
Disposal Authority (SMDA) Sites 9 and 9A, in Macomb County, Michigan.
Although the declaration in the ROD states the contrary, there was no
concurrence letter attached to the signed ROD because we were awaiting
confirmation that our~~comments on the last draft of the ROD had been
addressed. The State of Michigan does, however, concur with the remedy
proposed in the ROD for the first operable unit for this site since the
remedial action will halt further off-site migration of contaminated
groundwater.
The remedy selected in that ROD consists of:
leachate collection,
groundwater extraction on-site and off-site as necessary,
on-site treatment of groundwater and leachate with discharge to.
McBride Drain,
extension of the existing slurry wall,
replacement of water supply wells in the surrounding area with
municipal water supply,
deed restrictions and fencing to provide for the integrity of the
remedy,
and long term monitoring of groundwater, including selected
residential wells in the area.
It is the MDNR's judgement that although the selected remedial action for this
site will meet all legally Applicable or Relevant and Appropriate Requirements
(ARARs) pertinent to the action to be taken; it will not satisfy ARARs for the
site as a whole. This remedy will meet the Type A or B groundwater cleanup
criteria in Michigan's Act 307 rules at and beyond the landfill boundaries;
-------
Mr. Valdas Adamkus -2- September 3, 1991
however, the remaining contamination inside the landfill boundaries will
require a Type C final remedy for the site. The State of Michigan reiterates
the need for further action to address the landfill contents which EPA has
chosen to defer to a second operable unit. The landfill is, and will continue
to be, a source of contamination to the groundwater beneath the site. Until a
remedy is implemented which controls this ongoing source of groundwater
contamination, ARARs cannot be met.
Please be aware that there are two very significant court orders currently in
place regarding this site which may impact aspects of implementation. The'r
first is a 1989 Consent Decree between Macomb Township and the State of
Michigan which provides for residences in the vicinity of SMOA Sites 9 and 9A
to be attached to municipal water supply in the event that they become
contaminated. The second is the April 4, 1991 Circuit Court Order requiring
SMOA to remedy the sites. In addition to groundwater control actions outlined
in this ROD, the court order requires SMDA to construct a multi -media cap on
the site and a slurry wall and leachate collection system entirely around both
of the sites. We believe that implementation of the court ordered remedy will
meet federal and state ARARs. Although there is no direct conflict between
these orders and this ROD, it will be imperative for our agencies to work
closely on these actions to avoid duplication of effort and conflict.
It is my hope that in the near future our agencies can successfully select and
implement a final remedy for this site which meets federal and state
requirements and considers the existing judicial decisions achieved through
state enforcement actions.
Sincerely,
Frnk
Acting Deputy Director
517-373-7917
cc: Mr. Jon Dikinis, US EPA
Mr. Thomas Jacobs, US EPA, ORC
Mr. Douglas Ballotti, US ERA
Ms. Betty Lav is, US EPA •/'
Mr. Thomas Emery, Dept. of Attorney General
Mr. William Bradford, MDNR
Ms. Claudia Kerbawy, MDNR
Ms. Kate Par!ing, MDNR
------- |