United States
Environmental Protection
Agency
EPA/RODIR05-91/155
March 1991
Cry /
f8 ., 1--1 ~'11 IfO
Office 01
Emergency and
Remedial Response
oEPA
Superfund
Record of Decision:
Kentwood Landfill, MI
u . S. Environmental Protection Agency
Region 111 Hazardous Waste
Tachnicallnformation Center
841 Chestnut Street. 9th Floor
Philadelphia, PA 19107
._,
Hazardous Wast. COllectiOn ..
information Resource Center ~.
US EPA RegIon 3. ..
Philadelphia, PA 19107
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50272101
.
REPORT DOCUMENTATION 1" REPORT NO. I ~ 2.. A8cIpI8nI"o ~ No.
PAGE EPA/ROD/R05-91/155
.. TIIIa Ind IIubIIII!a L~D-
SUPERFUND RECORD OF DECISION 03/29/91
Kentwood Landfill, MI ..
First REmedial Action - Final
7. AufaCo) .. P8rf""'*'ll OrganlDtlon Aopt. No.
.. ~ OrganlDtlon -Ind - 10. ProjactITMkIW- UnIt No.
1 I. ConIr8c1{C) or GnnI(G) No.
(C)
(0)
1~ 1Ipao-r..'II OrgaNullan - Ind ....... 12.. Tn- 01 ~ . P8rtocI CoWNd
U.S. Environmental Protection Agency
401 M Street, S.W. 800/000
Washington, D.C. 20460 '"
15. "'n' ,""'-r-
n, AbahCI (UmIt: 2IID --)
The 72-acre Kentwood Landfill site is an inactive municipal landfill in Kentwood, Kent
County, Michigan. Land use in the area is primarily residential and recreational.
Twenty-two residences to the south and east of the site use ground water as their
drinkinq water supply. Landfilling operations at the site began in the 1950s, and
continul~d intermittently until the county capped and closed the landfill in 1976. The
site consists of two municipally-owned landfill areas: a larger original landfiil: and
a 20-acre southern extension located south-southeast of the original landfill. Both
landfills are constructed into the uppermost aquifer beneath the site, and as a result,
the landfilled wastes including garbage, rubbish, construction, and demolitions wastes
are in direct contact with the upper aquifer ground water. Site disposal records show
no indication that RCM hazardous wastes were placed into the landfills. In 1983,
construction of a leachate collection system to pump leachate to a publicly owned
treatment works (POTW) was completed on the eastern side of the original landfill,
however. contamination from leachate is still of concern. The primary contaminants of
concern affecting the debris, ground water, and leachate are VOCs including benzene,
PCE, and TCE: other organics; and metals including arsenic, chromium, and lead.
(See Att:ached Page)
17, DocunwnI Anaoy'Iia L D8ecr1pccn
Record of Decision - Kentwood Landfill, MI
First Remedial Action - Final
Contaminated Media: debris, gw, leachate
"Key Contaminants: VOCs (benzene, PCE, TCE), other organics, metals (arsenic,
b. ~pan.Endad T- chromium, lead)
c. COSATI ~
11. AwallabllIIy 518_1 ". s.curtty au. (Thia Aapoft) 21. No. 01 Pao-
None 72
2D. 8acurIty a- (Thie "-) 22. PItc8
None
".
(Sea ANSI-Z:88.II)
"N~_OII -
(~ 1f1'IS.35)
0...111._.01 c:-
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EPA/ROD/R05-91/155
Kentwood Landfill, MI
First RE!medial Action - Final
Abstract. (Continued)
The SelE!cted remedial action for this site includes improving the landfill cap
include gas controls and a leachate collection system; pumping and pretreating
water onsite along with collected leachate, as needed, before discharging to a
monitoring sediment, ground water, su:o:face water, and air; and implementing
institut~ional controls including deed and ground water use restrictions, and site access
restrict.ions such as fencing. If for any reason the leachate or contaminated ground
water cclnnot be treated by the POTW, these liquids will be treated onsite, with
subsequE!nt onsite discharge to surface water.- The estimated present worth cost for this
remedial action is $5,700,000, which includes an annual O&M cost of $210,000 for years
0-9, and $200,000 for years 10-30.
to
ground
POTW;
PERFO~~CE STANDARDS OR GOALS: Chemical-specific cleanup goals for
aquifer are based on SDWA MCLs and State standards including benzene
PCE 0.7 ug/l (State), TCE 3 ug/l (State), arsenic 0.02 ug/l (State),
(State), and lead 5 ug/l (State).
ground water in the
1 ug/l (State),
chromium 30 ug/1
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Declaration ~or the Record o~ Decision
Site Name and Location
~entwood Landfill
~entwood, Michigan
l.1~atement of Basis and PuJ::Pose
~li. decision document presents the selected remedial action for
the ~entwood landfill site, in ~entwooc!, Michigan, which was
chosen in accordance with the requirements of the Comprehensive
Environmental Response, Compensation, and.Liability Act of 1980
(<"'"ERCLA), as amended by the Superfund Amendments and
Roauthorization Act of 1986 (SARA) and, to the extent
practicable, the National oil and Hazardous Substances Pollution
Cc)ntingency Plan (NCP). This decision document explains the
factual and legal basis for selecting the remedy for this site.
~1e State of Michigan has assisted in the development and review
of the Administrative Record. However, V.S EPA has not received
a written confirmation of State acceptance of the selected
remedy.
~;sessment 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.
~scription of the Selected Remedv
The selected reme~y is the final remedy for the Site. The
remedy addresses the threats posed by the low level threat wastes
and contaminated ground water of the Site.
The remedy employ. engineering controls to contain the
landfilled waste (low level threat waste.) on-site. The remedy
also employs treatment of contaminated ground water. The
landfill. do not have a threat that can be classified as a
principal threat.
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.2be ..jor components of the selected remedy include th~
rolloving:
Groundwater:
.
Groundwater use restrictions;
.
Groundwater extraction followed ~y treatment of the
extracted contaminated water at a POTW. Extracted
vater viII be treated on site to .eet POTW pretreatment
standards if nece.sary, before being sent to the POTW.
Leachate:
.
A leachate extraction system will ~e installed to
reduce the amount of leachate in the landfill.
Leachate extracted would be treated at a POTW.
Extracted leachate will be treated on site to meet POTW
pretreatment standards if necessary, before being sent
to the PO'l'W.
Landfill Contents:
*
Landfill contents will be contained by utilizing
Subtitle D type consisting of (from bottom Up) a
clay layer, topped by a 6-inch layer of topsoil.
venting and leachate breakout Collection will be
incorporated into the cap design.
a RCRA
2-foot
Gas
Declaration of StatutorY ~termination,
Tbe selected remed~ is protective of human health and the
environment, compIles with Federal and State requirements that
are legally .applicable or relevant and appropriate to the
remedial action, and is cost-effective. This remedy utilizes
per.anent solutions and alternative treatment (or resource
recovery) technologies to the maximum extent practicable. The
remedy doe. not satisfy the statutory preference for remedies
that employ treatment a. a principal element.
Due to the large volume of landfilled waste that would need to be
~.ated, treatment of this low level threat waste is considered
!apracticable. Although the remedy selected employs treatment of
contaminated ground water, overall, treatment is not employed by
the remedy to an extent where it can be considered a principal
eleaent of the remedy. Instead, the remedy employs engineering
controls which will be protective of human health and the
environment to address the low level threat posed by the
landfilled waste and employs treatment to return contaminated
ground water to beneficial uses.
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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
hlsalth and the environment.
c1fLL~ Iffl
Da e
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DBCISION StDIKARY
A.
.Site Location and Description
~e Kentvood Lan~fill aite ia locate~ at .900 Walma Avenue in the
City of Kentvood, Kent County,-Michigan. The lan~fill is located
iame~iately east of the City of Kentwood Municipal Buildings.
Tbe 8ite occupie8 72 acres of lan~ that is bordered by the City
of Kentwood City Center and apartment buildings to the west, a
church an~ residential araas to the south, Plaster Creek and
ravine areas to the aast, an~ vacant resi~ential zone~ land, a
resi~antial araa an~ golf course to tha no~.
The site is actually comprise~ of two landfilled areas: the
original lan~fill which is the larger of the two and the southern
extension located just south-southeast of the original landfill.
Figure 1 is a drawing of the Kentwood Landfill Property. Figure
]A indicates the general location of the site.
The property is located near residential areas, schools and the
City of Kentwood City Center and is easily accessible to the
public. A land developer currently owns and plans to build
additional homes on the vacant land immediately to the north of
the site.
The City of Xentwood has a municipal water-supply system which
supplies the majority of households in the area of the landfill.
The source of water for this water-supply is Lake Michigan.
However, the Remedial Investigation (RI) identified 22 residences
in the area s~~rounding the site that use ground water as water
supplies. Eight residential wells were selected for sampling and
an,lysis. The basis for well selection was the proximity of the
wells to the Site.
The land to the west of the site, and the majority of the land to
the north and 80uth of the landfill is described as a till plain
(flat land). The land to the east and aome of the land to the
north and 80Uth of the landfill has ravines that drain into
Plaster Creek. The natural topography of the landfill site has
been changed ~ue to landfill activities. Ravines with
intermittent streams which drained into Plaster Creek have been
filled with waste.
1
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Homes
CJ
Kentwood
C"ty
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Figure 1
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o ~Ig 818
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~roximate
RaW\e Boundary
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WDflLL
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Site Location
Homes
DC
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County of Kent
City of Kentwood
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Kentwood Landfill
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F IGURE 1-~
SITE lOCATION MAP
KENTWOOO LANDFILL
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B.
.Site Historv and Enforcement Activities
~e ~entvood Landfill site originated as the Paris Township Dump
in the early 1950's. Refuse vas dumped into ravines and burned.
In 1966, the site was licensed as a solid waste disposal facility
by the Michigan Department of Public Health (MDPH) with the
81:ipulation that refuse vould be covered daily and burning vould
cease. In November 1966, the MDPH and the ~ent County Health
Departaent (~CHD) inspected the site and noted 8urface seeps of
leachate and open burning. Burning continued until at least
1969. In January 1968, the MDPH transferred the license to the
City of ~entvood.
"le City of ~entvood operated the site as-an open dump.ite from
Jnnuary 1968 to June 1970. In June 1970, the City of JCentwood
s.!nt a letter to the J(CHD, stating that the dump would be closed
to all haulers beginning June 27, 1970.
In 1971, the Kent County Department of Public Works (KCDPW) took
over operation of the landfill and obtained a license from the
MDPH. J(ent County designed an engineered landfill and the
flscility vas licensed in accordance vith Michigan Act 87 (P.A. of
1!~65). The operation plan for this engineered landfill called
for the excavation of 11 landfill cells around the ravine and
filling of the ravine. A clay berm was to be constructed at the
down-vater-gradient end of the cells supposedly to contain
leachate.
In June 1975, the J(CDPW was issued a license to operate an
additional landfill on a 20-acre site just south-southeast of the
original landfill. This landfill is called the southern
extension. The plans for this landfill called for the
excavation of 5 cells, each cell having a leachate collection
sump. The leachate sumps were not interconnected. Leachate was
to be removed by pumping the liquid into a truck and hauling it .
to a sanitary sewer connected to the City of wyoming wastewater
treatment facility for treatment.
Both the original and southern extension landfill cells were
constructed into the clay rich till that forms the base for the
uppermost aquifer beneath the site area (upper aquifer). As a
result the landfilled vaste is in direct hydraulic connection
with the upper aquifer ground water.
The original site and the southern extension landfills were
capped in late 1975 and early 1976. The J(entwood Landfill was
closed in May 1976. The site was operated prior to the enactment
of the Resource Conservation and Recovery Act of 1976, as
amended (RCRA).
2
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A leachate co1lection system at the eastern side of the original
landfill in order to intercept leachate breakouts (su~~ace seeps)
vas installed with construction beginning in the fall ~f 1981 and
campleted in the spring of 1983. This collection syste~
consisted of 6 inter:onnected aanholes connected to a ~':al
lift station pwapinc; into a forced main to a sanitarj' s~'.:,.r
leading to the City of Wyoming wastewater treatment facility.
Available records indicate that the ~entwood Landfill site
accepted veneral garbage, rubbish, construction and demolition
waste. No recorda indicating placement of RCRA hazardous waste,
at the site have been found.
~e U.S. EPA identified two Potentially Responsible Parties
(PRPS). These two parties were .the owners and operators of the
.ite, the City of Rentwood and the County of Rent. Both pp.Ps
entered into an Administrative Order by Consent with the U.S. EPA
in December of 1985 for the conduct of a Remedial Investigation
and Feasibility Study (RI/FS).
C.
Community ParticiDation
The RI Report, FS Report and the Proposed Plan for the Kentwood
Landfill site were released to the public for comment on February
14, 1991. These documents were made available to the public in
both the administrative record and an information repository
maintained at the U.S. EPA offices in Region 5, Xentwood City
Center and the Rent County Library. The notice of availability
for these documents was published in The Xentwood Advance and
Grand RaDid's Press New.papers~~n February 13, 1991. A public
comment period on the documents was held from February 20, 1991,
to March 21, 1991. In addition, a public meeting was held on
March 6, 1991. At this meeting, representatives from U.S. EPA
.~ Michigan Dep..tment of Natural Resources (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
requir...nt. of CERCLA Sections 117 and 113 (k) (2) (B) (i-v) have
been .atisfied.
3
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D.
SCODe and Role of Re$nonse Action Within Site strateav
~is ROD addresses the final remedy for the site. The
posed by this site to human health and the environment
landfilled waste, which is the source .aterial for the
~~e leachate, and leachate contaminated ground water.
~~e landfilled vaste is the source .aterial for contamination
from the site. This waste is classified as a low level threat
vaste. Leachate contained vi thin the landfilled waste is also
considered a low level threat vaste. Leachate in ground water is
classified as contaminated ground vater.
threats
are:
leachate,
Leachate and contaminated ground water vill be treated. The
landfilled waste will be contained .on-siteR. Treatment of the
landfill. contents was determined inappropriate. The size of the
landfill and the absence of known Ron-site" hot spots (areas of
concentrated hazardous substances within the landfill) that
represent major .ources of contamination preclude a remedy in
which landfilled yaste could be excavated and treated
effectively.
E.
Summary of site Characteristics
Pursuant to its authority under the Comprehensive Environmental
Response, Compensation and Liability Act of 1980, as amended
(CERCLA) and the National Oil and Hazardous Substances Pollution
Contingency Plan (NCP), a Remedial Investigation (RI) and
Feasibility Study (FS) were conducted at the site.
The followin9 ~onditions were observed at the Kentwood Landfill
site:
1.
-
Topoqraphy
The most prominent topographic features at the site are the
ravines and Plaster Creek to the east of the landfill. The
landfill began as placement of waste into existing ravines
at the site. Existing ravines and ravines that were filled
in exhibit(ed) intermittent streams and/or seeps which
flow(ed) into Plaster creek. As the landfilling operations
grew, additional cells were excavated into the till plain
west of the ravines and between ravines.
4
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2.
Bydrogeolof':!Y
'!'here are four aquifers beneath the landfill that were
- ~.ddre.sed during the re.edial inve.tigation. The.e aquifers
are tarmed upper, aiddle, lower and bedrock.
a. Upper Aquifer. '!'he upper aquifer i. unconfined
and underlie. aost of the area investigated. It ranges
in thickne.. frOJl 0 to 30 feet. '!'be ba.e of the upper
aquifer con.ists of a clay-rich-glacial till which i.
at an elevation above Plas"ar creek and its floodplain.
Where topography .teepens~ard Plaster Creek, the
upper aquifer has been er~ed and is not pre.ent. The
upper aquifer al.o terminate. al~ng ravines 8urrounding
the northern, 80uthern, and eastern perimeters of the
80uthern extension.
The top of the upper aquifer i. approximately at 750
ft. Mean Sea Level (MSL). The base of the upper
aquifer is approximately at 728 ft. MSL. These
elevations are generalized, .ince the thickness and
position of the aquifer varies within the investigated
area.
Ground water flow direction in the upper aquifer is
generally from west to east. North of the original
landfill the direction of ground water flow is
generally to the east-northeast. Ground water flows
toward ravines and Plaster Creek'. floodplain. In these
areas, upper aquifer ground water discharges into
Plaster Creek. The approximate ground water velocity
in the area of the original landfill i. 0.80 ft/day.
Thi. translates into an estimated 19,000 gallons of
ground water per day that flows horizontally into the
original landfill within the upper aquifer. No
calculation. were made for the southern extension.
The cells of the original an~ 80uthern extension
lan~f111s were excavate~ through the upper aquifer and
into the aqui tard forming the ba.e of the upper
aquifer. This me.n~ t~at waste placed into the
landfills is in dlrect contact with upper aquifer
ground vater and ground water actually moves laterally
through the waste. See Figure. 2 and 3.
b. Middle Aquifer. The middle aquifer underlies, and
is separated from, the upper aquifer by a clay-rich-
till aquitard. The aquifer appears to be made up of
discontinuous sand lenses which are confined or
unconfined over different portions of the area of
investigation. The thickness of the middle aquifer is
approximately 50 feet. The average thickness of the
5
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Fir,\1r£' 2
,.
750
2»
, SAND
N
740
SOOTH
110
760
730
/ APPROXIMATE GROUNDWATER
J--- ELEVATION
SOUTHERN EXTENSION'
720
SCALE: HORIlONTAL~ l"aIOO'
VERTICAL: l"aIO'
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overlying aquitard separating the upper aquifer (and
landfill cells) and the middle aquifer is approximately
40 feet. The ~op surface of the middle aquifer is
approximately 10 f.et below the floodplain of Plaster
creek; therefore, the aquifer is separated from the
surface water by an ..timated 10 feet of clay-rich
till and does not discharge significantly to Plaster
cr.ek.
The top of the .iddle aquifer is approximately at 710
ft. MSL. The ba.e of the middle aquifer is .
approximately at 670 ft. MSL. These elevations are
generalized, since the thickness and position of the
aquifer varies within the investigated area.
The vertical hydraulic head (static water pressure)
between the upper aquifer and middle aquifer is
approximately 40 feet. This vertical head indicates
that there is potential for ground water movement
downward from the upper to middle aquifer. The
vertical head also indicates that the intervening
aquitard offers some resistance to downward movement of
upper aquifer ground water. The remedial investigation
estimate~ that approximately 2,100 gallons of water per
day can move through the overlying aquitard into the
middle aquifer beneath the original landfill. An
estimated 350 gallons of water per day can move down
into the middle aquifer beneath the southern extension.
Ground water flow direction in the middle aquifer is
uncertain due to the low hydraulic gradient measured
within the aquifer and periodic fluctuations in ground
water levels at different rates causing apparent
reversals of flow. The approximate ground water
velocity for this aquifer in the area of the site is
0.12 ft/day.
The cells of the original and southern extension
landfills were excavated .0 that they penetrate the
aquitard overlying the middle aquifer but do not extend
through the aquitard.
c. Lower Aquifer. This aquifer consists of
predominantly sand and gravel. The lower aquifer is
separated from the middle aquifer by clay-rich till.
The top of the lower aquifer is approximately at 650
ft. MSL. The bas. of the lower aquifer is
approximately at 645 ft. MSL. These elevations are
generalized, since the thickness and position of the
aquifer varies within the investigated area.
,
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- --'!'he qround water flow direction was not esteclished
during the investigation since only two JIIon:.'. :Iring
vells were placed in the stratum. Seasonal
fluctuations in ground water levels of the middle and
lover aquifers generally coincide. The ground ~ater
level of the lover aquifer is below the base of the
- aiddle aquifer.
'!'he aquifer is underlain by . stratum consisting of
clay and ailt with minor amounts of aand and gravel.
~is atratum is approxiJllately 7 ft. thick. Beneath
this atratum is the Michigan Formation comprised of
ahales and gypsum. In the vicinity of the Site this
formation is not considered an aquifer. ~e Michigan
Formation is approximately 150 f.et thick.
d. Bedrock Aquifer. The principal bedrock aquifer in
the investigated area is the Marshall Sandstone. The
top of this formation lies approximately at 480 ft.
MSL. There are seven identified residential vells in
the investigation area that draw water from this
aquifer.
Because each of the four aquifers are either currently used
or are potentially available for drinking vater or other
beneficial uses the V.S. EPA has classified these ground-
waters as Class II Ground Waters. This classification is
aite specific and limited in scope to the remedial action
for this Site. The State of Michigan has not classified
this ground vater.
3.
Landfills
Waste vas placed at the original landfill site in existing
ravines during the early operating life. Later, waste was
placed in east and west trending excavated trenches. Waste
was placed in the southern extension landfill in east and
weat trending excavated trenches.
~e types of waste placed in the landfills included
garbage, rubbish, construction and demolition wastes.
Waste was placed into the landfills before the enactment of
RCRA. Inform@tion on the va.te placed into the landfills
was not sufficient for o.s. EPA to confirm that the waste
placed into the landfills were -RCRA hazardous waste" like
or not.
7
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Table A
contaminants of Concern in Leachate
summary of Detected Chemical Concentrations
Concentration Units in ug/l (ppb)
contaminant
CAS t
Frequency
of Detection
Range of Detected
Concentration
Acetone
6"7-64-1
Benzene
71-43-1
Chloroethane
75-00-3
1,1-Dichloroethane
75-34-3
1,2-Dich1oroethane
107-06-2
1,2-Dichloroethene
cis 156-59-2
trans 156-60-5
1,2-Dichloropropane
78-87-5
2-Hexanone (MBK)
591-78-6
2-Butanone (MEK)
78-93-3
4-Methyl-2-Pentanone
108-10-1 (MIBC)
Methylene Chloride
75-09-2
Trichloroethene
79-01-6
Vinyl Chloride
75-01-4
Benzo(a) anthracene
56.55-3
Benzo(k)fluoranthene
207-08-9
4 -Chloro..3-methylphenol
!>9-50-7
Diethylphthalate
84-66-2
2,4-Dimethylphenol
105-67-9
Fluoranthene
206-44-0
2 -MethylJphenol
a-cresol 95-48-7
4-Methylphenol
p-cresol 106-44-5
Phenanthrene
85-01-8
Aluminum
7429-90-5
Antimony
7440-36-8
7/9
7/9
11 - 8700
9 -
5/9
5/9
29 -
5 -
1/9
4/9
11 -
1/9
2/9
14 -
34 - 6500
630
6/9
2/9
107 -
50
130
890
14
290
24
170
7/9
2/9
1 -
3 - 2300
9
3/9
1/9
6 -
1/9
3/9
10 -
5/9
4/9
2 -
2 -
1/9
4/9
63 -
8/9
2/9
140
9
18
27
53
10
23
950
5 -13000
4 -
21
392 - 3940
5/9
5/9
114
2 -
Mean
3638
45
100
344
14
216
24
503
3059
170*
883
9*
140*
9*
18*
27*
30
10*
23*
493
5100
21*
3405
72
-------
Both the original and southern extension landfills have
leachate collection systems. Leachate removed from the
systems is treated at the City of Wyoming wastewater
treatment plant. Both landfills' leachate collection
.systems are inadequate in preventing releases of leachate
onto the surface, surface water and ground water.
Both landfills are covered with clay caps. The caps have
fissures, thin areas, areas with excessive slope and areas
of inadequate slope. The caps do not comply with the State
standards for solid waste landfill caps found in rules
promulgated under HI Act 641.
Waste decomposition gases were detected in the leachate
collection system for both landfills.
4.
contamination
a.
Source.
The source of contamination from this site is the
landfilled waste. Some of the landfilled waste lies
below the natural ground water table of the upper
aquifer. This waste is in direct contact with
laterally moving ground water. Leachate is produced
by the movement of ground water through the waste and
also by movement of precipitation down through the cap
and into the waste mass. This lateral movement of
ground water through the waste is believed to be the
major producer of leachate in the landfills.
Hazardous constituents in the waste mass are present as
indicated by the chemical composition of the leachate.
Volatile and semi-volatile organic compounds,
inorganic compounds and metals were detected in the
leachate including benzene, vinyl chloride, arsenic and
lead. Table A lists the concentrations of
contaminants of concern in the leachate.
The leachate produced and released by the
contaminated ground water, soils, and has
impact surface water and sediments at and
site.
site has
potential to
near the
8
-------
.- --....
.--- - --. .
-. .- - ..-
- -.. - -
-.------
-. - - ..-
- -- - ---
n
-- -- -.- -
- - .....
Table A Continued
contaminarlt Frequency Range of Detect.~ Mean
CAS . of Detection Concentration
Araanic 6/9 4 - 19 12
7~\40-38-2
Barium 9/9 255 - 1300 768
7440-39-3
CacSmium 5/9 9 - 92 74
7440-43-9
Chromium 6/9 11 - 105 75
7440-47-3
Iron 9/9 90,800 -981,000 461,210
7439-89-6
Lea~ 5/9 9 - 171 150
7439-92-1
Nickel 9/9 48 - 472 249
7440-02-0
Vana~ium 5/9 13 - 138 109
7440-62-2
Frequecy of Detection means how many times the constituent was detected in
a given number of aamples. As an example 7/9 means seven out of nine
samples were found to have the constituent.
* . Maximum Detected Concentration
-------
- . - -- . -
~--:= ~ -- .:--- --
.- -- -
- --'- --_.-.
- .- -- . - . -- - -
-- -- - --
-
..- _.. -
----.-- . -.
-- ---.- -- --
--- -- .
_. --. - -_.
.- -~......-
--
.--~ -
. - ---
b.
Ground Water.
Aquifers beneath the aite are termed upper,
.iddle,lower and bedrock.
i. Upper Aquifer. !'be landfill. have
contaminated the upper aquifer. Figure 4
indicate. the approximate boundaries of the
contamination in the upper aquifer. Contaminated
9roundwater has aigrated to areas outside of the
~entwood Landfill property. The ground vater
contaminant. include those found in the leachate.
Table B .ummarizes the concentrations of
contaminants found in the contaminated upper
aquifer qround water.
ii. Middle Aquifer. The landfills have
contaminated the middle aquifer to a much lesser
extent. Only one volatile organic was detected
above the sample quantification limit: 1,2-
Dichloroethane at 8 uq/l. Only one semi-volatile
organic, bis (2-ethylhexyl) phthalate, was
detected and its concentration was below the
sample quantification limit.
iii. Lower Aquifer. No evidence of contamination
was found with the two wells screened in the lower
aquifer.
iv. Bedrock A~~ifer. Because of the depth to the
bedrock aquifer and intervening aquitards the
likelihood of bedrock aquifer contamination was
considered very low. The RI did sample and
an.lyze private wells in the area for possible
contaminants from the site. No evidence of
contamination from the site was found in these
vells.
c.
Soils
Surface .oil samples were taken at background
locations, original .ite, .outhern extension, and
riparian areas (ravines).
Leachate from the landf!!!. has contaminated the
8urface soil to a varying degree around the landfill
.ite mostly in localized areas where leachate breakouts
and seeps were observed. The contamination is mainly
indicated by hiqher concentrations inorganic parameters
than those found in background. Some higher
concentrations of organic parameters were also
9
-------
-=--
- -.--. -- -- - -
-- .--..- --....--
--~- -
.. ---_.._--- ------
- --
-- -
't"~ ""..- "" "
. - 0 -.. - .,
~
B D
r:=J
Homes
o
:.--.-f
' '
, "
......1 -.
"
..- "', Plaster
........: .: Creek
.- ........-
.
: ......
..- -.
. . ..
8..8 .
.
.
..
.
.
.
-.....
-..,
: .....
, .'
Ap-proximate---. ...
Ravine Bounda
Location of Upper Aquifer
Ground-Water Contamination
Homes 0 c
-------
_.- -- --
....... ..
- _._- - .....
--- -- - .- -- -.....- - - ..
- -:~ ...:-. ~
.., '-
--
Table B
eontamir.ant. of Concern in Upper
Summary of Detected Chemical
Concentration Units in
Aquifer Ground Water
Concentrations
ug/l (ppb)
contaminant Frequency Range of Detected Mean
CAS t of Detection Concentration
Acetone 6/21 1 - 620 109
67-64-1
Benzene 12/21 2 - 101 24
71-43-1
Chloroethane 8/21 3 - 66 23
75-00-3 .~.
1,1-Dichloroethane 15/21 1 - 160 62
75-34-3
1,2-Dichloroethane 6/21 1 - 26 6
107-06-2
1,1-Dichloroethene 4/21 1 - 15 5
75-35-4
1,2-Dichloroethene 10/21 2 - 1200 216
cis 156-59-2
trans 156-60-5
1,2-Dichloropropane 6/21 2 - 160 29
78-87-5
Tetrachloroethene 6/21 15 - 710 128
127-18-4
Trichloroethene 8/21 2 - 450 113
79-01-6 --.
Vinyl Chloride 6/21 .3-3 - 130 39
75-01-4
Aluminum 11/11 18 - 1530 502
7429-90-5
Antimony 1/15 28 28*
7440-36-8
Arsenic . 9/15- 3 - 78 31
7440-38-2
Barium 13/15 22 - 560 342
7440-39-3
Chromium 1/15 7 7*
7440-47-3
Iron 15/15 17 -130,000 43153
7439-89-6
Lead 2/1 2 - 24 15
7439-92-1
Nickel 7/15 30 - 90 53
7440-02-0
Zinc 15/15 33 -26000 7241
* - Maximum Detected Concentration
-------
. -
.- .--- .-- .=-=~--
~. -.;;.:.:: -.-~':'--:'..-' .' . -
-- - -- ---
-.' .
._---- '- -
----
-- --- -- -
-- .
-:
------
..
detected.
d.
Surface Water and Sediments.
Surface water samples were taken from Plaster Creek,
intermittent streams in ravines northeast of the
original landfill and from water ponding on the site.
The waters of Plaster Creek and intermittent streams
.bow negligible impact by the aite. The water sampled
from an impoundment at the northeast corner of the
original landfill contained elevated concentrations of
chloride, iron, ammonia, 8ulfate and bis(2-
ethylhexyl)phthalate and di-n-o~tyl phthalate.
Analyses of sediments of Plaster Creek downstream from
the Site indicate minor elevations in concentrations of
metals, ammonia, grease and oil at the sampling point
compared to upstream sample analyses.
F..
SummarY of Site Risks
~Jrsuant to the NCP, a baseline risk assessment was performed
bclsed on the present condition of the site. The baseline risk
a!;sessment 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:
No "off~site" ground-water use restrictions will be
enforced;
The upper aquifer ground water contaminated by the site
may be used as a drinking water source;
Adjacent "ott-site" residential development will
continue to occur;
Parts of the site might be used for residential
development; and
Access restrictions such as fencing of the site will
not be implemented.
10
-------
. -- ---
-- - -- - + - .
..
-
- ~ _.
-
.-- -- ---
-
1.
~ontaminant Identification
- -- -.-
-..---- .--
- ----.
Tbe media of concern for human exposures were identified
- primarily as ground water, and soils. Leachate from the
--landfills is the major source of contamination of these
.environmental .edia. Surface water media was not considered
for human exposure due to the negligible impact on this
medium by the 8ite. Surface water was however, evaluated
for environmental impact.
The contaminants of concern selected for non-carcinogenic
risk characterization in ground water were:
Acetone
1,2-Dichloroethane
Tetrachloroethene
Arsenic
Lead
Benzene
1,2-Dichloroethene
Vinyl Chloride
Barium
Zinc
Chloroethane
1,2-Dichloropropane
Antimony
Iron
Aluminum
The contaminants of concern selected for carcinogenic risk
characterization in ground water were:
Chlorethane
1,2-Dichloroethene
Trichloroehene
Arsenic
Nickel
l,l-Dichloroethane
1,2-Dichloropropane
Vinyl Chloride
Chromium
Aluminum
1,1-Dichloroethene
Tetrachloroethene
Antimony
Lead
The contaminants of concern selected for non-carcinogenic
risk characterization in leachate and leachate breakouts
were:
Acetone Benzene
1,2-Dichloroethane 1,2-Dichloroethene
2-Hexanone 2-Butanone
Trichloroethene Vinyl Chloride
Benzo (a) anthracene Benzo (k)
1,2-Dimethylphenol Fluoranthene
4-Methylphenol Antimony
Barium Cadmium
Lead Nickel
Aluminum Phenanthrene
11
Chloroethane
1,2-Dichloropropane
Methylene Chloride
Diethylphtalate
fluoranthene
2-Methylphenol
Arsenic
Iron
Vanadium
-------
-- ~ ... _..
-0. --. .--. -.
-. ------ -
----..---- -----
_.-~--
-- _.- ~~_.--::- -.--.
-. - ---
-- - .-----
---.-- ---
.. .
--- --
. - - ---
-
--
-.
----
The contaminants of concern selected for carcinogenic risk
characterization in leachate and leachate breakouts were:
Chloroethane 1,1-Dichloroethane 1,2-Dichloroethene
2-Hexanone 4-Methyl-2-Pentanone
~ethylene Chloride Vinyl Chloride' Benzo (a) anthracene
Benzo (k) fluoranthene 4-Chloro-3-Methylphenol
Fluoranthene 2-Methylphenol 4-Methylphenol
Antimony Arsenic Cadmium
Chromium Lead Mickel
Aluminum Phenanthrene
The contaminants of concern selected for risk
characterization from surface soils were:
Acetone 2-Butanone
Toluene Xylene
4-Methylphenol Fluoranthene
Bis (2-ethylhexyl) phthalate Butyl
Di-n-butyl phthalate
Barium Chromium
Nickel Zinc
Ethyl Benzene
Diethylphtalate
Phenanthrene
benzyl phthalate
Arsenic
Iron
Analytical data gathered on surface water samples from
Plaster Creek and Plaster Creek sediments indicate minor
exceedances of constituents compared to background levels
in the creek. The risk assessment concluded that the water
and sediments in the Creek do not pose a risk to humans.
2.
Exposure Assessment
Potential exposure to contaminants from this site are as
follows:
Incide~al ingestion of surface soils by trespassers,
site workers and residents:
Dermal contact with surface 80il by trespassers, site
workers and residents:
Dermal contact with leachate breakout water by
trespassers and residents.
Dermal contact with leachate and leachate breakout
water by site workers:
Accidental ingestion of leachate breakout water
by trespassers and residents:
Accidental ingestion of leachate and leachate breakout
water by site workers:
12
-------
-- .-.--. --
.- ----
-._. ---. ---
-- -.- - .
. - - .. - - . .
.- ---.---. ._--- -
.. -- -_.
':e1r~..-::::I.......:
--- -":,..
..- - -..--
._-=a~
.....,;-~_.-
...--=.~. -.--
'---
- ----
-----
.--- -.- --
-..
-..-.. -
,.....-. -
...- - -
. .
'''4040 _..
:.
..-.- -
----.--
-.. .
_.
Inhalation of volatiles emitted from leachate in
confined spaces by site workers; and
Possible future use of upper and middle aquifer ground
vater for drinking and bathing, exposures would be to
.off-site" residents and .on-site" residents through
ingestion, inhalationvhile showering and dermal
contact while bathing and showering.
~-
-. .
3.
Risk Characterization
For each of the potential receptors, "the risks associated
with ingestion, inhalation and dermal absorption to the
site-specific contaminants from different routes of exposure
have been evaluated. Both non-carcinogenic and carcinogenic
health effects have been estimated.
Reference doses (RfDs) have been developed by U.S. 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 deri~ed 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 ef£ects 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'. 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 potentia1~ significance of multiple
contaminant exposures within a Ringle medium or across
media. Any Hazard Index value greater than 1.0 suggests
that a non-carcinogen potentially presents an unacceptable
health risk.
13
-------
The followinq table indicates the total Hazard Index for
., different scenarios.
Total Hazard
Recet>tor Indices ITHI*1
1. Adult Worker/
Non-Resident 1.3E-03
2. Adult Off-Site
Resident 4.4E+OO
3. Adult Worker/
Off-Site Resident 4.4E+OO
4. Adult Off-Site
Resident/Trespasser 4.4E+OO
5. Adolescent Off-Site
Resident/Trespasser 6.6E+OO
6. Child Off-Site
Resident 1.SE+Ol
7. Adult On-Site
Resident 4.4E+00
B. Adolescent
On-Site Resident 6.6E+00
9. Child On-Site
Resident 1.SE+Ol
*
THI value includes inhalation of volatiles from
leachate in confined spaces.
The Hazard Index exceeds the value of 1.0 for all "on-site"
and "off-site" residential scenarios.
Table C provides an additional breakdown of Hazard Indices
relatinq to exposure routes.
Cancer potency factors (CPFs) have been developed by u.S.
EPA's Carcinogenic Assessment Group for estimatinq excess
lifetime cancer risks associated with exposure to
potentially carcinoqenic chemicals. CPFs, which are
expressed in units of (mq/kq-day)-l, are multiplied by the
e.timated 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" .etlect5 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 epidemioloqical 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).
14
-------
,..... C
r'''.'ed '1'''''' ""'e.
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.- -
-
.Excess Lifetime Cancer Risks are determined by mUltiplying
the intake level with the cancer potency factor for each
contaminant of concern. ~ese risks are probabilities that
are generally expressed in scientific notation (e'i' 1X10-6
or 1E-6). An excess lifetime cancer risk of 1X10-
indicates that, as a plausible upper bound, an individual
has a one in one .illion chance of developing cancer as a
result of site-related exposure to a carcinogen over a 70-
year lifetime under the specific exposure conditions at a
.ite. The 0.5. EPA generally attempts to reduce the excess
lifetime cancer risk posed by a Superfund sites to a range
of 1E-04 to 1E-06 (1 in 10,000 to 1 in 1 .illion), with an
emphasis on the lower end 1E-06 of th. scale.
The following table indicates the Excess Lifetime Cancer
Risks for different scenarios.
.
..
Rece'Ctor
Total Incremental Cancer Risk.
Adult Worker../
Non-Resident
Adult Off-Site
Resident
Adult Worker../
Off-Site Resident
Adult Off-Site
Resident/Trespasser
Adult On-Site
Resident
2.4E-06
1.7E-02
1.7E-02
1.7E-02
1.7E-02
Except for Adult Worker, all risk values include an
incremental cancer risk of 1.7£-02 from future
contaminated ground water use.
For adult worker, an incremental cancer risk of 1.2£-06
is included from inhalation of volatiles from leachate
in confined spaces.
The excess lifetime cancer risk for all "on-site" and "off-
site" based reasonable maximum exposure in the residential
scenarios exceed the acceptable risk range of 1£-04 to 1E-
06. This risk range is a1so exceeded by the "on-site"
resident who does not use contaminated ground water. Table
D provides an additional breakdown of excess lifetime cancer
risk relating to exposure routes.
15
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-------
-
4.
Environmental Risks
In addition to human health risks, the risks to the
-environment were a180 considered during the remedial
investigation. It is estimated that the greatest risks
posed by the site are to aquatic life in surface water in
the vicinity of the site. Leachate breakouts and
contaminated ground water flows into Plaster Creek. As long
as these liquids continue to be produced by the site they
vill be a source of contamination of the Creek.
Terrestrial organisms may also be affected by the leachate
and contaminated ground vater seeps through ingestion and
dermal contact.
5.
Risk Summary
The potential excess lifetime cancer risk iosed by the site
exceeds the acceptable risk range of lXlO- to lX10-6
principally from the use of contaminated ground water.
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 qround water. 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. The site poses risks
to r.on-h~~an receptors from contaminants released from the
site into surface waters.
c; .
Environmental Standards not met at the Site.
In addition to posing unacceptable risks to receptors, the
JCentwood landfill site does not meet certain applicable or
J~elevant and appropriate Federal or State environmental
]~equirements (ARARs) at this time.
1. kG
The existing landfill cap does not meet the requirements of
Michigan State Solid Waste Rules promulgated under Michigan
Act 641, the current State landfill closure regulations
vhich have been determined to be relevant and appropriate
for this site.
16
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......---.
- - .--
-- - --.--
~. -
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--
2. Ground Water
~able E lists the representative chemicals found in the
--contaminated ground water plume and the corresponding
Federal and State preliminary ground-water clean-up criteria
which the u.S. EPA believes to be adequately protective.
The ground water contaminant plume contains concentrations
of hazardous substances which exceed .ost of these ground-
water standards and clean-up criteria.
3.
Ground Water Protection Goals and the National
Continqencv Plan
~e
The u.s. 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
.inimize untreated waste. Title 40 of the Code of Federal
Regulations (40CFR) Section 300.430(a) (1) (i».
The NCP states that the U.S. 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. .-30(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 res~rictions 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 8ubstitute for active response aeasures as the 801e
remedy unless such response measures are determined not to
be practicable.... (40 CFR Section 300.430(a)(1)(i11) (D».
4. State of Michiaan G~oun~ Water Protection Goals
Michigan Act 307 provides fo~e"medial action, at
contaminated sites within the-S~ate, which "shall.be
protective of the public heal t)1", safety, and wel fare 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
17
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-- - ~. -~ - -
----~ .
. --.
-
. - - -
..
Table E
Comparison of Federal and state Ground Water Remediation Standards
Concentration Units in ug/1 (ppb)
contaminant
CAS .
Benzene
71-43-1
Ch1oroethane
75-00-3
1,1-Dichloroethane
75-34-3
1,2-Dich1oroethane
107-06-2
1,1-Dichloroethene
75-35-4
1,2-Dichloroethene
cis 156-59-2
trans 156-60-5
1,2-Dichloropropane
78-87-5
Tetrachleroethene
127-18-4
Trichleroethene
79-01-6
Vinyl Chloride
75-01-4
Arsenic
7440-38-2
Chromium
7440-47-3
Lead
.
7439-92-1
Nickel
7440-02-0
Nt . Net Established
T - Tc Be Considered
P - Proposed
SDWA HI Act 307
MCL TypeB
5 1
NE 7
Nt 700
5 0.4
7 0.06
70 (T) 70
100 (T) 140
5 (T) 0.5
S (T) 0.7
5 3
2 0.02
50 0.02
100 (T) 30
lS (P) 5
100 (T) 100
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.'- ..-
-'.--- -
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--- --
-
-...--
or .ubstances from the aquifer...." Michigan Act 307 also
provides for the determination of acceptable criteria for
- ground-water remediation at the .i te.
5. Clean-~D Standards
V.S. EPA's ground-water clean-up policy is to attain Maximum
contaminant Levels (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 10-4 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).
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 and the
environment and the use of the involved resource. R.
299.5709 and R. 299.5711 provide 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). The u.S. EPA has determined that
Michigan Act 307, Type B criteria are protective and are
applicable or relevant and appropriate to the Kentwood
Landfill .ite.
Table F lists the Ground Water Remediation Standards for the
Kentwood Landfill site.
~S4!!
'95;
18
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. -.- -_.
Table F
Ground Water Remediation Standards
Kentwood Landfill
C'ontaminant Standard
CAS . ug/l
Benzene 1
71-43-1
Olloroethane 7
75-00-3
1,1-Dichloroethane 700
75-34-3
1,2-Dichloroethane 0.4
107-06-2
1,1-Dichloroethene 0.06
75-35-4
1,2-Dichloroethene
cis 156-59-2 70
trans 156-60-5 100
1,2-Dichloropropane 0.5
78-87-5
Tetrachloroethene 0.7
127-18-4
'l"r i chl oroethene 3
79-01-6
Vinyl Chloride 0.02
75-01-4
Aluminun 50
7429-90-5
JU1timony 3
7440-36-0
Ju-5enic 0.02
7440-38-2
Chromium 30
7440-47-3
]~ad 5
7439-92-1
Jlfickel 100
7440-02-0
Wher~ the Federal or State remediation standard established for a
contaminant is lower than the method detection limit for that
contaminant, the method detection limit will be used a5 the
Remediation Standard for the Site.
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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 focus the development of alternatives to address the threats
at the site. The PS report documents the evaluation of the
magnitude of site risks, 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 Kentwood Landfill
site.
1.
Description of Alternatives
The alternatives passing through the screening process and
considered for the detailed analysis in the Feasibility Study
were:
Alternative 1: No Action
Alternative 2: Access Restrictions, and Site Monitoring
Alternative 3:
Access Restrictions, Site Monitoring, Cap
Improvements, Landfill Gas Control, Leachate
Collection, "On-sit€' Ground-water Extraction
Wells, and Discharge of Leachate and
Contaminated Ground Water to a Publicly
Owned Treatment Works (POTW).
Alternative 4:
Access Restrictions, Site Monitoring, Cap
Improvements, Landfill Gas Control, Leachate
Collection, "On-site" and "Off-site" Ground-
water Extraction Wells, and Discharge of
Leachate and contaminated Ground Water to a
POTW .
Alternative 5:
On-site Incineration of the landfilled waste
with Off-site Ash Disposal, "On-site" and
"Off-site" Ground-water Extraction Wells, and
Discharge of Contaminated Ground Water to a
POTW .
19
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-- --
-...-
(Note: The term "on-site" when used to describe
the location of ground-water extraction wells (or
residences) means the placement of these wells (or
residences) within the property boundary of the
land currently owned by the PRPs for the Kentwood
Landfill. The term "off-site" when used to
describe the location of ground-water extraction
wells (or residences) means the placement of these
wells outside of this property boundary. This use
of the terms .on-site" and "off-site", when
describing the wells (or residences), is not
consistent with the definition of on-site in the
NCP. Under the NCP'. definition of this term all
wells (or residences) placed into (or on top of)
the plume of contaminated ground water at this
site would be considered on-site.
Alternative 1:
No Action
The NCP requires that the u.s. EPA evaluate the No-Action
Alternative to provide a baseline for comparison of the
effectiveness of the remedial alternatives. .
Under the No-Action Alternative, no active response measures
would occur. No institutional controls would be implemented
to prevent human contact with contaminants, no reduction of .
the toxicity, mobility or volume of contaminants, or of the
rate of leaching of contaminants to the ground water, would
be provided by this alternative. No risk reduction would
result from this action. The No-Action Alternative does
not meet applicable or relevant and appropriate requirements
(ARARs) for ground water and landfill closure at the site
and is not protective of human health and the environment.
Alternative 1 has no cost.
~
Alternative 2:
Access Restrictions and Site Monitorina
Under Alternative 2, limited action would be taken to
prevent direct human contact with the contaminants at the
site. A fence and signs would be installed and maintained
to prevent persons from.t~esrassing the site. Deed and
ground-water use restrictions would be placed on the site
property to prevent the development of the landfilled areas,
to prevent access to contaminated portions of the site and
to prevent consumption of contaminated ground water.
Restrictions would be placed on the use of land and/or
ground water outside of the Kentwood Landfill property
boundary that has been contaminated, to prevent access to
contaminants.
20
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--
..__. --- ...--
.. ---- - _.-
-.r_- -~--~
...
- -
-- ------..
. . .
---- . -
-.- "-- .-- -
Monitoring of the site including, but not limited to,
-.onitoring of ground water aquifers, would continue to track
contamination from the landfills and other conditions.
While Alternative 2 would control access to the site and
contaminants, it would not prevent production of leachate
and movement of contaminants from the landfills. This
alternative does not reduce the toxicity, .obility or volume
of contamination. This alternative relies an institutional
controls to prevent buman exposure to site contaminants
which can not be considered effective or permanent in the
long term. These institutional controls do not provide any
protection to the environment. Thus, Alternative 2 provides
no risk reduction. Alternative 2 would not meet ground
water or landfill closure ARARs (Safe Drinking Water Act
(SDWA) and RCRA).
Alternative 2 has an estimated
estimated annual operation and
The present worth, based on 30
$1,000,000.
capital cost of $280,000 and
maintenance cost of 50,000.
years at 5%, is estimated at
Access Restrictions. Site Monitorina. Cap
ImDrovements. Landfill Gas Control. Leachate
Collection. "On-site" Ground-water Extraction
Wells. and Discharoe of Leachate and
Contaminated Ground Water to a Publiclv
Owned Treatment Works (POTW).
Alternative 3 includes the all components of Alternative 2.
In addition this alternative includes:
Alternative 3:
Improvements of the existing landfill caps to bring the
caps i~o compliance with the current promulgated State
of Michigan Act 641 landfill cap (cover) standards.
Improvements would include, but not be limited to,
compaction, correct cap composition and thickness,
slope, vegetative cover and maintenance.
Installation of a
landfill gases as
promulgated State
standards.
system to control the release of
required to comply with the current
of Michigan Act 641 landfill
Collection of J~achate from the landfills for
treatment. -.'
..12
Collection of contaminated ground water for treatment
using "on-site" ground-water extraction wells.
21
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- ----
- ~.- ~.. - - - . .
---.--..----------...--- .-
... . - -
- - -. ._--
.--. .--.- --
.----------
.- --
- ---:. .~ .
-.-
Discharge of the leachate and contaminated ground water
to a POTW for treatment.
~e access restrictions and site monitoring would be
established as in Alternative 2. The landfill caps would be
improved to the MI Act 641 standards in order to prevent
direct.contact with landfill wastes and to reduce the amount
of precipitation infiltration through the landfilled wastes.
Landfill gas control systems would be installed to prevent
build-up of gases within the landfill and uncontrolle~
8igration of gases away from the landfill. Leachate and
contaminated ground water would be extracted from the site
for treatment. Treatment of these liquids would take place
at a POTW. POTW pretreatment standards would be met by
pretreatment of these liquids on-site prior to discharge
into storm sewers for the POTW.
If for any reason, the leachate and/or contaminated ground
water can not be treated by a POTW, these liquids will be
treated on-site and discharged to surface waters in
compliance with the substantive requirements of an NPDES
permit, as administered by the State under Part 21 of
Michigan Act 245.
Collection of contaminated ground water and leachate would
be conducted to meet the ground-water remediation standards
as listed in Table F. Based on computer modelling the
Feasibility Study estimated that the ground-water
remediation standards would be met within all areas of the
contaminated plume in 19 years. To prevent leachate
production by lateral movement of upper aquifer ground water
through the landfilled waste, the extract of ground water
would continue to maintain the upper aquifer ground water
table below the landfilled waste to the maximum extent
practicable. production by lateral movent
Under this alternative, the placement of ground-water
extraction wells is limited to fton-siteft (within the
boundary of the Rentwood Landfill property). This
limitation could prevent the installation of ground-water
extraction wells into areas, outside of the property
boundary, which could collect contaminated ground water more
efficiently.
Alternative 3 has an estimated capital cost of $2,300,000
and estimated annual operation and maintenance cost of
$190,000. The costs assume some pretreatment will be
necessary prior to discharge of leachate and contaminated
ground water to a POTW. The present worth, based on 30
years at 5t, is estimated at $5,200,000.
22
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- _._._~
... . --
- - -_.
-
- - . --
.~. .~-
"-'-'- ---.
.0_-
----- ..
- --
- _.
- -.-..
- .-- 0- -
-
---.
Alternative 4:
Access Restrictions. Site Monitorina. Cap
ImDrovements. Landfill Gas Control. Leachate
Collection. "On-site" and "Off-site" Ground-
water Extraction Wells. and Discharae of
Leachate and Contaminated Ground Water to a
POTW .
Alternative 4 includes all components of Alternative 3 with
the addition of "off-site" ground-water extraction wells.
~is alternative would allow the installation of ground-
water extraction wells in areas outstde of the boundary of
the Xentwood Landfill property. The.~cSdition of "off-site"
ground-water extraction wells is a majer benefit to the
remedy.
Alternative 3 includes a limitation on the installation of
extraction wells to within the Kentwood Landfill property.
This limitation is based on property boundaries, lines drawn
on land deeds, as opposed to the actual extent of
contaminated ground water and the need to extract that
ground water for treatment as quickly as possible.
Alternative 4 does not restrict the placement of extraction
wells. Thus, this alternative will allow design of an
extraction system that is the most efficient in extracting
contaminated ground water. The FS estimated that this
alternative will meet the remediation standards for ground
water listed in T~~le F in 9 years. -:~~
. --
Alternative 4 has an estimated capit.lm~ost of $2,600,000.
The estimated annual operation and mai~tenance cost of for
years 1-9 is $210,000 and for years 10-30 is 200,000. The
costs assume some pretreatment will be necessary prior to
discharge of_leachate and contaminated ground water to a
POTW. The present worth, based on 30 years at 5', is
estimated at $5,700,000.
Alternative 5:
On-site Incineration with Off-site Ash
Disposal. "On-site" and "Off-site" Ground-
water Extraction Wells. and Discharae of
Contaminated Ground Water to a POTW.
The principal difference between this alternative and all
the others is that this alternative addresses the source of
the contamination at the site through thermal destruction of
the landtilled waste while the other alternatives contain
the landfilled waste within the present landfills. The
landfilled waste would be excavated and incinerated on-
site. Ash from the incineration would be managed in a
23
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----..--
-~--- -
----
- ..... -- - -
---
--. -"
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-.-- - ...--- - ---..
--..--
---
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landfill off-site.
'l'he thermal destruction of the waste would be requiree! to
..et the .ubstantive State and Federal requirements for the
incineration of 801id waste. '!'he off-.ite ash aonofill
would require all necessary permits required for .olie! waste
ash landfills.
Alternative 5 includes the same active ground water
remediation component of Alternative 4.
Tbe estimated time needed to locate the incinerator, locate
and permit an off-site ash aonofill and incinerate the waste
is 10 years. '!'he ground water remed~ation would aeet the
remediation standards in approximately 9 years.
Alternative 5 has an estimated capital cost of $10,000,000
and estimated annual operation and maintenance cost of
$10,000,000. The costs assume some pretreatment will be
necessary prior to discharge of leachate and contaminated
ground water to a POTW. '!'he present worth, basee! on 30
years at 5', is estimated at $160,000,000.
I.
Comparative Analysis of Alternatives:
The Nine Criteria
I]n accordance with the NCP, the relative performance of each
alternative is evaluated using the nine criteria, 40 CFR Section
300.430 (e) (9) (iii), as a basis for comparison. An alternative
providing the "best balance" of trade-offs with respect to the
nine criteria is determined from this evaluation.
The following two threshold criteria: overall protection of human
health and the environment, and compliance with applicable or
relevant and appropriate requirement., are criteria that must be
met in order for an alternative to be selected.
1.
OVerall Protection of Human Health and the Environment
OVerall protection of human health and the environment
addre.se. whether a remedy eliminate., reduces, or controls
threats to human health and to the environment.
The aajor exposure pathways of concern at the Xentwood
Landfill site are the potential ingestion of and contact
with contaminated ground water and leachate produced by the
landfills. Ba.ed upon these pathways of concern, the
alternatives were evaluated on their ability to reduce the
amount of leachate produced by the landfill to prevent
exposure to leachate and contaminated ground water and to
. achieve the ground-water remediation standards.
24
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- --- - -_. - -
- -- ~.
-.- ---.
_.- - -.- -.- - -
--_. --. - ---
- ----- -_.-
'-.
.':.-=- --
-
... --
. - .-. . -..
- - - -
---_.. --
Alternatives 3, 4 and 5 are protective of human health and
the environment.
Alternatives 3 and 4 bave active ground-water remediation
..aaures that would reduce ground-water contaminants to the
re88diation .tandards, and leachate collection and other
.easures to reduce the amount of leachate produced by the
landfills. Alternative 4 vill achieve ground-water
remediation .tandards in half the tiae of Alternative 3.
Alternative 5 includes the ground-water remediation measure
of Alternative 3 and 4 and involves destroying the source of
the le.chate by thermal destruction of the landfilled
vaste.
OVer the long term, Alternatives 1 (No Action) and 2 (Access
Restrictions and Site Monitoring) do not provide adequate
protection of human health and the environment .ince no
protection of ground water is provided either through
extraction and treatment of ground-water contaminants or
through cap improvements or leachate collection.
Alternative. 1 and 2 do not prevent ~~rect exposure to
contaminants by hu~ans and environmental receptors.
Contaminants in the leachate produced by the landfills would
continue to contaminate ground water and the 8urrounding
environment.
- --
...
;
2.
~rac :~-
Compliance wi*h Applicable or Relevant and Appropriate
Requirements
This criterion evaluates whether an alternl~ive meets
applicable or relevant and appropriate req rements set
forth in Federal, or more stringent State, ~nvironmental -
standards pertaining to the site or proposed actions (Note:
Section K discusses ARARs in more detail for the site.)
The aajor ground water ARARs include the requirenlents of the
Federal Safe Drinking Water and State Safe Drinking Water
Act (Act 3") and the State Environmental Response Act (Act
307). Landfill closure ARARs Jnclude Michigan Act 641 which
include the landfill CAp .peci~ication8.
- ~
.c.
Alternatives 1 and 2 do not m, ~the requirements for the
remediation of contaminated 9r~und water of MI Act 307
.ince no active measures for g=ound-water remediation would
be initiated. These alternatives do not meet the landfill
elosure of MI Act 641 .ince no work would be done to improve
the ~p to HI Act 641 standards.
25
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.-- -
Alternatives 3 and 4 include improvements to the existing
. cap and installation of gas controls to comply with MI Act
641.
Alternatives 3, 4 and 5 include active ground-water
remediation which would aeet the ground-water remediation
.tandards of the Safe Drinking Water act and MI Act 307 Type
e criteria. Pretreatment-and treatment of leachate and
contaminated ground water would be carried out to aeet the
requirement. of the Clean Water Act and Clean Air Act.
Discharge of treated leachate and ground water would comply
with the Clean Water Act.
Alternative 5 includes thermal destruction of the landfilled
waste and would comply with Federal and state requirements
for 801id waste incineration.
3.
Long-Term Effectiveness and Permanence
This criteria refers to the ability of an alternative to
maintain reliable protection of human health and the
environment over time (lower residual risk) once the clean-
up goals have been met.
Alternative 5 provides the most reliable protection since
the landfilled waste is destroyed and ground water
remediated.
Alternatives 3 and 4 provide long-term effectiveness by
containing the landfilled waste on-site through engineering
controls, collecting leachate and preventing the production
of leachate. These ,lternatives involve continual
extraction of leachate and ground water to prohibit the
production of leachate .eaning that they are not as
permanent as Alternative 5. I
Alternative. 1 and 2 do not provide long-term effectiveness
or permanence since they provide no response measure to
address the wastes or contamination. These alternatives
rely exclu.ively on institutional controls to protect human
health. Institutional controls do not protect the
environment and can not be considered permanent.
26
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--_.
-. --.... --.-
--_.-
--. -..
-7" :"'"'7='-~~-_::-= .. ~-=..:. .-""'T---'" ---~ -=-~-.;---~~ ."'::'- - --:-'.
-.
-
- --
. . .._- .- - - - -
4. Reduction of Toxicity, MObility, or Volume Through
Treatment.
~i. criterion evaluates treatment technology performance in
'the reduction of chemical toxicity, .obility, or volume.
This criteria addres.es the statutory preference for
.electing remedial actions which include, as . principal
8lement, treatment that permanently and significantly reduce
the volume, toxicity, or .ability of the bazardous
.ubstances, pollutants, and contaminants.
. !
. .
Alternative 5 includes the qreatest level of ~ieatment of
contaminants at the site. This alternative e~'loys
treatment to an extent to which it can be d.emed as a
principal element of the remedy. The landfilled waste would
undergo thermal destruction. The leachate and contaminants
in ground water would undergo treatment through on-site
pretreatment and off-site through treatment at a POTW.
Alternatives 3 and 4 include treatment of leachate and
contaminated ground water. The leachate and contaminants in
ground water would undergo treatment on-site through
pretreatment and off-si~. ~nrough treatment at a POTW to
reduce the mobility and ~ icity of contaminants and reduce
the amount of cor.~amina~ ;round water.
Al ternatives 1 and 2 do ,.:- -: provide any treatment of the
hazardous substances, po:~~~ants and contaminants.
5.
Short-Term Effectiveness
Short-term effectiveness considers the time to reach clean-
up objectives and the risks an alternative may pose to site
workers, the community, and the environment during remedy
implementation until clean-up goals are achieved.
Alternative 4 reaches the ground-water clean-up goals
(remediation standards) and protects human health and the
environment fastest. This alternative allows placement of
qround-water extraction wells within and outside of the
~entwood Landfill property. This flexibility of placement
would allow installation of th~~~ extraction wells in the
.os~ efficient area to collect .e contaminated ground water
plume. The estimated time nece.sary to achieve the ground-
water remediation standards i. ~ years. This alternative
also involves containment of the landfilled waste on-site
within a relatively ahort period of time. Community and
worker health can be protected during the construction of
the remedy through safety control measures.
27
-------
- - .- - - -- ~.-.o:-=-'==-=' - -
--" -
-- -.- .
. --.
-
.. .
Alternative 3 reaches ground water remediation .tandards in
an e.ttaated 19 years. The longer time necessary for the
. ground vater clean-up i. due to the limitations on the
in. tal 1 at ion of ground-vater extraction well. to within the
--Itentwooc! Landfill property boundary. Community and worker
..alth can be protected during the con.truction of the
remedy through safety control aeasures.
Alternative 5 reache. the remediation .tandards in an
..tiaated 9 years. community and worker health would be
acre difficult to protect due to the activity of excavating
the landfilled vaste, and incineration on-site. Uncovering
vaste vould increase the potential for exposure to hazardous
constituents by direct contact and i~alation.
Alternatives 1 and 2 may never achieve ground-water
remediation standards since no active ground-water
remediation would take place and the landfills would
continue to produce leachate.
6.
Implementability
This criterion considers the technical and administrative
feasibility of implementing an alternative.
Ho significant implementation problems are projected for
Alternatives 1 through 4. Cap materials are expected to be
obtainable from nearby .ources including a stockpile
currently on-site. The engineering expertise and
construction practices and equipment for installation,
operation and maintenance of these alternatives' components
are available and proven. Access to areas outside of the
Kentwood Landfill property is necessary for Alternative 4,
e.g., for installation of the ground-extraction system and
piping to the pretreatment system. Although, statutory
authority ~rantees access to these areas, access to these
araas aight be a delay.
Alternative. 3, 4 and 5 include treatment of the leachate
and contaminated ground water at a POTW. Early discussions
with the City of wyoming waste water treatment plant
indicate that this waste can be accepted and treated by the
plant. If for any reason, POTW treatment is prohibited the
treatment of these liquids would be completed on-site prior
to discharge to .urface water.. The on-site treatment would
..et the substantive requirements of ARAR permits including,
but not limited to, requirements of Clean Air Act, RCRA,
Clean Water Act (NPDES).
28
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---..-.- --.- ---------
"'. ... -...-
---. -.
---.';".. ~ =.:- "":'". .":":":-.:::.-. 'n
'-" -
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-...... ~-..-.7
~~--
-- -
-.- . .
.. .
. -
... .
- .
. -'..-'
--
--
.. .
-
Alternative 5 poses substantial i.plementation problems.
. Siting and per.itting of an off-site facility for the ash
disposal would be necessary. Siting of an incinerator in
:::residential communities can be very tiae consuming and
-difficult. The actual excavation of landfilled waste can be
very complex and 8Ust be done very carefully to assure
protection of workers and the community.
7. Cost
~is criterion compares the capital, operation and
.aintenance, and present worth costs of implementing the
alternatives at the .ite.
The costs for each alternative are as follows:
Alternative
Capital Cost
Annual O'M Cost
Present Worth
1
2
3
..
5
$0
$280,000
$2,300,000
$2,600,000
$10,000,000
$0
$70,000
$190,000
$210,000
$10,000,000
$0
$1,000,000
$5,200,000
$5,700,000
$160,000,000
Present Worth- Present Net Worth calculated for 30 years at
5t. Calculation of Present Net Worth i. an estimate of the
value of money used to pay future costs in "today's" .
dollars. The calculation i. based on the assumption that an
existing dollar will earn interest and therefore has a
greater value that a future dollar.
8.
State A~ceptance
The State of Michigan has assisted in the development and
review of the Administrative Record. However, U.S EPA has
not received a written confirmation of State acceptance of
the selected remedy.
t.
Community Acceptance
Ba.ed on the comments received by the U.S. EPA, the selected
alternative appears to be acceptable to the community.
Community concerns are addressed in the attached
Responsiveness Summary.
29
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---.- .
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;s..
- Selected Remedy
~ssed upon consideration. of the requirements of CERCLA and the
NCP, balancing of the nine criteria, and public comment, the u.s.
EJPA has determineeS that Alternative 4 ia the most appropriate
remeeSy for the ~entwood Landfill aite.
~be component. of the selecteeS r..eeSy are as follows:
1. Acce.. Restrictions
a. Temporary aneS/or permanent fences aneS signs shall
be erected aneS maintained arouneS the landfill. and
pretreatment/treatment systems a. .pecifieeS by u.s.
EPA. The u.S. EPA specification. will include, but
not be limited to, the location, de~ign specifications,
warning language, and timing of installation of the
fences and signs.
b. Institutional controls including, but not limited
to, deed restrictions to regulate the development of
the ~entwood Landfill property, and ground water use
restrictions in the areas that have contaminated ground
water ahall be instituted and enforced. Ground-water
use restrictions may be rescinded after remediation
standards are met and proven to be maintained.
The purpose of these restrictions is to prevent exposure to
site contaminants, prevent erosion of the cap and provide
aecurity for the remedial action equipment.
2.
Site Monitoring
a. GrobneS water aneS Surface water monitoring. Ground
water aquifers and .urface waters and sediments in the
aite vicinity .hall be .ampleeS aneS analyzeeS
periodically to monitor chemical contaminant levels
during .ite remeeSiation.
GrouneS-water monitoring .hall inclueSe, but not be
limiteeS to, monitorin~ of the upper, mideSle and lower
aquifers. Sampling ar,eS a7'&alysis .hall include, but not
b, limiteeS to, existing ground water monitoring wells
and additional groundwater monitoring wells installed
a. specifieeS by O.S. EPA, and residential wells.
The start and frequency of sampling and analysis, and
chemical analyzed for (analytes) of ground-water
monitoring wells, residential wells, and surface water
and sediments shall be specified by the U.S. EPA.
30
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--. ~ - -..
-_. -- - - -- -
---~
_.~--~ .- . - - - .- ..._---- --..
-----------. .
---- ~_._. --~
-- ~ -- -_.
-- .
--- --.. ---.
-- ..--.-
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--.- - --~.- . ... - ---- ...---- - ----. .
.- ---
_.- - ----
------
...-- . - --.
Ground water and surface water .onitoring shall be
implemented for up to 30 years following the
achievement of the vround wate~ remediation standaras.
b. Volumes and contaminant concentrations of
extracted leachate and contaminated ground water shall
be .easured periodically.
Cap I.provements including Landfill Gas Controls and
Leachate Collection.
~e existing cap on the landfill shall be improved and/or
replaced so that it complies with MI Act 641, including the
final cover specifications found under R 299.4305 Rule 305.
This State regulation includes, but is not limited to: cap
thickness and composition (2 feet of clay), compaction,
vegetative cover, maximum and minimum slope, and gas venting
performance.
3.
A Michigan Act 641 cap is considered protective for this
site since it would provide protection against direct
contact with waste at the site and act as a significant
barrier to infiltration of precipitation. The waste in the
landfills is in direct hydraulic connection with upper
aquifer ground water and produce significant amounts of
leachate. For this Site, a l.ss permeable cap such as a
hazardous wast. cap under Michigan Act 64 would not provide
a significant relative reduction of leachate. A leachate
collection and ground-water extraction system would still be
required.
The leachate-collection system shall be installed to prevent
leachate brea~outs at the cap. The gas venting system shall
be .onitored periodically to determine if the levels of
..iaaiona .ay cause potential health hazards, If potential
b.alth bazards are indicated, an emission treatment system
ahall be placed in the venting system to reduce emissions to
acceptable levels.
4.
Ground-Water Extraction Wells
Ground water extrac~ion wells shall be installed to extract
contaminated vround .ater for treatment. Ground water shall
be extracted until the remediation standard. of Table Fare
achieved in all parts of the ground water contaminant plume
including, but not limited to, contaminant plumes documented
during the remedial investigation and/or discovered during
site .onitoring above. Therefore, the point of compliance
for the ground-water remediation standards is the edge of
31
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---- -..
.--.......
- --- -. - -
- . .- ~-
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----"
- -
_.
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. .-. .---.
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. .
-
-
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_.
landfilled waste. The placement of ground-water extraction
. vells may be within and/or outside the Kentwood Landfill
property boundary. The qround-water extraction wells will
-- 81so serve to lower the vater table height in the upper
aquifer below the level of the landfilled waste, thus
minimizing the production of leachate reducing the amount of
ground water that moves laterally through the waste.
The 90al of this remedial action is to restore the ground
vater to its beneficial use and to protect against current
and future exposures. Ground vater is a valuable resource
and should be protected and re.tored. Ground water not
currently used may be a drinking water supply in the
future. Ground water plays an impo~ant role as a water
8upply for environmental uses other than human consumption.
88sed on information obtained during the RI and FS, the u.s.
EPA believes that the selected remedy will meet these g081s.
It may become apparent during implementation or operation of
the qround-water extraction system, that contaminant levels
cease to decline and are remaining constant at levels
higher than the ground water remediation standards over
some portion of the contaminant plume. In such a case, the
system performance standards, the system design, and/or the
remedy may be reevaluated. And if such a reevaluation
results in a determination that the remediation standards
should be changed, a new proposed plan will be released for
public comment and an amended Record of Decision will be
issued.
It is projected that the ground-water extraction system may
attain the remediation standards within 9 years. System
performance monitoring will be performed on a regular basis.
If warranted, the system may be modified without amendment
to this ROD,-in order to achieve the goal as follows:
(a) Pumping may be discontinued at individual wells
where remediation standards have been attained:
(b) Wells may be pumped on an alternate basis to
eliminate stagnation points:
(c) Additional extraction wells may be installed into
any aquifer in the vicinity of the site to facilitate
or accelerate clean-up: and
(d) .Pulse pumping" may be performed to allow the
aquiferes) to equilibrate and allow adsorbed
contaminants to partition into ground water for
extraction.
32
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.-
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.... .. -. - .. - ~ - : -. -.- "=".
- ------ - -
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-
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Ground water will be 8onitored periodically at any well
where pumping has ceased to ensure the remediation standards
continue to be .et.
5. Discharge of Leachate and Contaminated Ground vater to a
POTW for ~reat8ent.
~e selected alternative contemplates that the extracted
leachate and contaminated ground vater ahall be treated by a
POTW. Pretreatment standards ahall be .et by an on-site
treat8ent ayst.. prior to diacharge o~ the leachate and
contaJIinated qround vater to a PO'1'W. The apecifics of the
design and operation of the treatment systems will be
determined during the Remedial Design phase of the project.
Should the treatment of the.e liquids at a POTW be
restricted for any reason, the complete treatment of these
liquids to the standards of a NPDES permit shall occur on-
aite. Such a treatment system will be required to meet the
substantive permit requirements under, but not limited to,
the Clean Air Act, Clean Water Act, RCRA and any more
atringent State standards. ~e treated liquids would then
be discharged to surface waters in accordance with the
substantive requirements of a NPDES permit.
6.
Other provisions.
Mitigative measures will be taken dur ,g remedy construction
activities to minimize the impacts o!oise, dust and
erosion run-off to the surrouncUng cc. .uni ty and environs.
Fugitive dust emissions shall not violate the National
Ambient Air Quality Standard for particulate matter smaller
that 10 microns (PM-10). Potential runoff, silting and
sedimentatioR problems from construction shall be mitigated
to comply with MI Acts including, but not limited to, Public
Acts 203 (1979), 346 (1972) and 347 (1972) for wetland
protection, inland lakes and streams, and soil erosion and
aedi.entation control, respectively.
The landfilled waste will continue to be contained on-site.
Since this landfilled waste is the source of the
c~ntaminants, hazardous constituents will therefore remain
.~ the site. A review of aite conditions, the remedy's
progress toward achievement of remediation standards and the
availability of new emerging technologies which could
further reduce the toxicity, 80bility or volume of hazardous
constituents remaining at the landfill shall be reviewed
every 5 years after the initiation of the remedial action.
33
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1:.
Statutory Determinations
~~e .elected remedy 8uat ..ti.fy the requirementa of Section 121
II through f of CERCIA t.o:
Protect human bealth and the environment;
Comply vith ~ or Juatify a Waiver;
Be cost effective;
Utilize permanent .olutions and alternative treatment
t.echnologies or reaource recovery technologies to the
.aximum extent practicable; and
Satiafy a preference for t.reatm~nt that reduces
toxicity, 80bility, or volume aa a principal element
of the remedy.
T.he implementation of the selected alternative at the Kentwood
]Andfill site satisfies these requirements of CERCLA section 121
ItS follows:
1.
2.
3.
4.
5.
1.
Protection of Human Health and the Environment.
Implementation of the .elected alternative will reduce and
control potential risks to buman bealth posed by exposure to
contaminated ground water. Extraction and treatment of
contaminated ground water to meet Ground-Water Remediation
Standards will reduce the potential exceS8 lifetime cancer
risk due to ingestion of contaminated ground water from the
unacceptable risks currently posed (e.g., 1.7 x 10-2 ) by
ground water contaminant. to a maximum ri.k for individual
carcinogenic chemicals of approximately 1 x 10-6. As
above, ~ssuming that all carcinogens were only treated to
the 1 x 10-6 level, the maximum cumulative risk would be
approximately 1 x 10-5, vhich is an acceptable level. The
Hazard Inde~would be reduced to below 1.0, which is also an
acceptable level.
Extracting ground water in the vicinity of the landfills
vill lower the water table of the upper aquifer to below the
~evel of the landfilled waste to the maximum extent
practicable, thus minimizing the production of leachate by
ground vater flowing laterally through the waste.
Institutional controla vill provide ahort-term effectiveness
for the prevention of drinking contaminated ground water
until the Ground Water Remediation Standards are met. The
.elected remedy al.o protects the environment by reducing
the potential ri.ks posed by .ite chemical. discharging to
'.urface water (Plaster Creek).
34
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-.:..:.:.~ ':'-."-.:-. ~_._- - --. .---- - ------- -.- - -..---......
_H " -. =-=-- -.....r-:-.::';~'...-.-._."=:--=:'-.... - - .... u ~--- ... ~ ...~--'::- -..-;';'7--: - .-":':-::""-" -.
._- --
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.-- -.- --.-
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. -
- - -- ...- -
-...--
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-
---
Capping the landfill, in addition to reducing any potential
further risk posed by exposure to landfill contaminants,
- will reduce precipitation infiltration through the cap and
--aaintain that reduction over time. Iaprovement of the cap
will reduce qround-water contaminant loading to the
aquifer, allowing the restoration of the aquifer within a
reasonable tiae fr..e.
50 unacceptable short-tera risks vill be caused by
iapl8JDentation of the remedy. The community and .ite
workers 8ay be exposed to noise and du.t nuisances during
construction of the cap. Ala above, 8itigative aeasures will
be taken during remedy construction activities to ainimize
impacts of construction upon the 8urrounding community and
environs.
2. Comcliance 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-sDecific ARARs
Chemical-specific ARARs regulate the release to the
environment ~~ specific substances having certain
chemical ChE :teristics. Chemical-specific ARARs
typically d~ rmine the extent of clean-up at a site.
i. Landfills
No Federal chemical-specific standards exist for
the landfills.
Within the landfilled waste, the 0.5. EPA has
determined that Act 307, Type C criteria would be
appropriate. The foreseeable uae of the site is a
landfill, and Type A or Type B criteria would not
provide for the derivation of clean-up standards
which could ~ met u~less the source materials
were removed. ~hereror., Type C criteria would
provide for a cost-effective and appropriate
remedial action for t."e landfill areas.
-
...
~::~e
"':':'-a~-
- -
35
-------
-- -.--
- ~ ="T.-
- . .
--- -.
-
- ----
.-----
--
.--------
--..----
. -----
. -
ii. Ground Water
Federal ARARs
Maximum contaminant Levels (MCLa) and, to a
certain extent, 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 the Kentwood
landfill site, MCLs and MCLGa are not applicable
but are relevant and appropriate, since the upper
aquifer is a Class II aource which could
potentially be used for drinking in the areas of
concern, and haa the potential to contaminant the
aquifers beneath it that are being used for
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 is applicable or relevant and
appropriate to the Kentwood Landfill site. The
U.S. EPA has determined that acceptable standards
for ground water clean-up, that have been derived
under Type B criteria, would be protective in all
th~ areas of the plume outside of the landfilled
waste. Clean-up levels derived under Type B
criteria would allow the aquifer to be restored to
its beneficial uses by achieving the risk-based
clean-up standards. The 0.5. 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.
The U.S. EPA has determined that Type 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.
36
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----
o iii. 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)
are nonenforceable quidelines 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 ~ederal AWQC
would not be applicable except for °retreatment
requirements for discharge of treat~d water to a
Publicly OWned Treatment Works (POTW). CERCLA
(section 121(d)(1» requires the U.S. 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 the City of
Wyoming waste water treatment plant (if
pretreatment criteria are met) or to Plaster
Creek, 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 jnto Plaster Creek.
State ARARs
Po~ions 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 Plaster Creek, to the indirect
discharge through ground water movement to a
surface water body, or to a discharge to a POTW.
37
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- --
--
.
i :.
b. Location-sDecific 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 10o-year flood plain must be adequately
protected against a lOO-year flood event (e.g.,
geotextiles should be used to secure topsoil, etc.)
Section 404 of the CWA requlates 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. The site is not in a wetland.
However, remedy activities may pose a threat to
wetlands including siltation and sedimentation from
construction. The scope of the impact has not yet been
determined. 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) requlates any activity which may take
place within wetlands in the State of Michigan. Act
203 i5 relevant and appropriate to the remedial action
at the Rentwood Landfill site: it may also require the
replacement of adversely impacted wetlands with
comparable resources.
The Inland Lakes and Streams Act 346 of 1972, as
amended, requlates inland lakes and streams in the
State. Act 346 would be applicable to any dredging or
filling activity on Plaster Creek bottomlands.
38
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.
The Soil Erosion and Sedimentation Control Act 347 of
1972 regulates earth changes, including cut and fill
activities, which .ay contribute to 80il 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 cap and ground-water extraction
system construction activities since these actions
could impact the Plaster Creek, which is less than 500
feet from the landfill area.
c. Action-SDecific ARARs
Action-specific ARARs are requirements that define
acceptable treatment and disposal procedures for
hazardous substances.
Federal ARARs
For landfill closure, RCRA Subtitle C requirements are
not applicable since the hazardous substances of
concern were disposed of prior to November 1980. RCRA
Subtitle C requirements are not relevant and
appropriate because the landfilled waste is not
considered sufficiently similar to listed and/or
characteristic RCRA Subtitle C waste.
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.
RCRA Subtitle C requirements, including LDR, would be
relevant and appropriate if wastes were to be excavated
and managed and these wastes were determined to be
characteristic RCRA Subtitle C hazardous wastes.
The only foreseeable manner in which the selected
remedy may store or dispose of hazardous waste is when
or if the ground-water treatment system re~ires
emission control units to capture or contain volatile
organics derived from, aeration of the leachate and
contaminated ground water. The RCRA waste generation
and temporary storage regulations under 40 CFR Part 262
would then be appllc~blp. ~o that action. For example,
activated carbon canisters utilized as emission
controls would be managed, when spent, as a
characteristic waste if the waste canisters were to
fail the Toxicity Characteristic Leaching Procedure
(TCLP) test.
39
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-.- - .- - . .-
--.----.---
--- -.. -- -- .----
. --
. -- - - ---
-- ----
-- -- -----.-- --- - .---
-- _. - - --
- .- .-
_.. - -- .-
-... - - - -.- -
-- - - -. -
. -
--- -
. -. .---
.- .
-"--'
- -
---
---- --
--. --
.~
-.----
--
-.-.-
--
The treatment contemplated for the extracted leachate
and contaminated ground water includes treatment of
these liquids by a PO'1'W. The POTW is regulated by
regulations under the National Pollution Discharge
Elimination System (NPDES). The actions of this remedy
ahall aeet the substantive requirements of NPDES.
State ARARs
The State of Michigan administers RCRA within the
State. Under Hazardous Waste Management Act 64 of
1979, as amended,:~e State regulates the generation,
transport, treatm.~~, storage, and disposal of
hazardous waste. ~t 64 also regulates the closure,
and the postclosure care, of hazardous waste disposal
facilities in the state. As with RCRA Subtitle C,
above, Act 64 i8 not applicable or relevant and
appropriate to closure of the landfill. Act 64 would
be applicable to the treatment or storage of hazardous
landfill contents and/or hazardous residuals from on-
site treatment units.
The Michigan Solid Waste Management Act (Act 641) is
applicable or relevant and appropriate for closure of
the landfill. The landfill cover design required by
regulation promulgated under this State statute
provides adequate protection from direct contact with
the landfilled waste and minimizes leachate produced by
the site. Because wastes landfilled at the site are in
direct contact with the upper aquifer ground water, the
leachate and ground-water extraction system will
provide a major role in reducing leachate produced.
This leachate ground-water extraction system would be
required regardless of the permeability of the cap.
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
vater. These rules would be applicable to the
discharge of treated ground water to Plaster Creek or
to a POTW treatment system.
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.
The U.S. EPA has determined that the substantive
provisions of Parts 6 and 7 of Act 307 are applicable
or relevant and appropriate to the Kentwood Landfill
site. The Act 307 rules require that remedial actions
shall be protective of human health, safety, the
40
-------
-
"-. -----=-"Ir"; ":-
~ ~ - ~-:--~..::
- .
.- -- - -------
-. , --
-. ..
-
.
"..
.
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
levela), Type B (clean-up to risk-based levels), or
~e C (clean-up to risk-based levels under site-
specific considerations) criteria. u.s. EPA has
determined that the Type C criteria are appropriate for
the containment portion of this remedy. Type B
criteria are appropriate for the ground-water
remediation portion of this remedy. The point of
compliance for the Type B 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. The table under Section I. 7.
the costs associated with the implementation of the
remedies.
lists
Alternative 1
alternatives.
protection of
ARARs, and do
and Alternative 2 are the least expensive
However, they do not provide adequate
human health and the environment, do not meet
not provide effectiveness over the long term.
Alternatives 3 and 4 have similar costs. The lower costs of
Alternative 3 compared to 4 reflect the limitation of
placing ground water extraction wells to within the Kentwood
Landfill site property boundary. Alternative 3 might have
fewer wells installed and less contaminated ground water to
treat. Alternative 3 would be less effective in remediating
ground wa~er. These placement limitations mean that
Alternative 3 would take over twice as long to achieve
remediation standards when compared to Alternative 4: 19
years vs. 9 years.
The .elected alternative (Alternative 4) is considered cost-
effective. This alternative achieves remediation standards
.ore quickly and is protective of human health and the
environment. The shortening of time needed to achieve
remediation standards easily out-weighs the additional costs
associated with installation of extraction wells outside of
the property boundary.
Alternative 5, the most expensive alternative evaluated in
detail in the feasibility study, would permanently destroy
source waste at the site, whereas Alternative 3 and
Alternative 4 only contain the wastes. However, due to
potential short-term risks associated with on-site
incineration at this site, extreme cost, plus the fact that
41
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--- ------...
--- _.
..
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.
Alternative 4 would remediate the ground water with a
identical ground water extraction and treatment system, the
U.S. EPA has determined that Alternative 4 is a cost-
effective remedy.
Utilization of Permanent Solutions and Alternative
Treatment Technologies or Resource Recoverv
Technoloaies to the Maximum Extent Practicable
~e 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 ARARa, the u.S. 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.
4.
While the selected remedy does not offer as high a degree of
long-term effectiveness and permanence as the incineration
alternative, it will significantly reduce the inherent
hazards posed by the contaminated ground water and leachate
by treating these substances while containing the waste at
the site and prohibiting further generation of leachate.
These benefits are achieved at a reasonable cost.
Contaminants from the ground water are extracted and
permanently addressed through treatment.
The selected remedy can be implemented quickly and achieves
ground water remediation goals the quickest.
5. Preferenc~ for Treatment as a Principal Element
The statutory preference for treatment as a principal
element of a remedy is not satisfied by the selected
alternative.
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.
.
Due to the large volume of landfilled waste that would need
to be treated, treatment of this low level threat waste is
- considered impracticable. Although the remedy selected
:_employs treatment of contaminated ground water, overall,
treatment is not employed by the remedy to an extent where
it can be considered a principal element of the remedy.
Instead, the remedy employs engineering controls which will
be protective of human health and the environment to address
the low level threat posed" by the landfilled waste and
employs treatment to return contaminated ground water to
beneficial us.s.
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RESPOMSrvEMESS SUMMARY
~is Responsiveness Summary has been prepared to meet the
requirements of Sections 113(k) (2)(B) (iv) and 117(b) of the
eoaprehensiv8 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 (U.S. EPA) to respond
w...to each of the significant comments, criticisms, and new data
submitted in written or oral presentations" on a proposed plan
for remedial action. The Responsiveness Summary addresses
concerns expressed by the public, potentially responsible parties
(PRPs), and governmental bodies in the written and oral comments
received by the U.S. EPA and the State regarding the proposed-
remedy for the Kentwood Landfill site.
A. OVerview
~e selected alternative for the Kentwood Landfill includes:
Access Restrictions, Site Monitoring, Cap Improvements,
Landfill Gas Control, Leachate Collection, "On-site" and
.Off-site" Ground-water Extraction Wells, and Discharge of
Leachate and Contaminated Ground Water to a POTW.
The selected alternative was identified as Alternative .4 in the
Feasibility Study Report dated November 1990, and as the
preferred alternative in the Proposed Plan dated February 1991.
More detailed information on the selected alternative, as well as
other alternatives considered to remediate this site, is
available in these documents. The documents are available in the
information repository and administrative record for the Site.
No changes have been made to the selected alternative
(Alternative t4) compared to preferred alternative (Alternative
.4) as proposed to the public in the Proposed Plan.
The majority of public comment on the proposed plan appears to
support the selection of this alternative as the final remedy for
the Site.
B.
Backaround on Community Involv~ment
The RI ~ort, FS Report and the Proposed Plan for the Kentwoo
Landfi1~~ite were released to the public for comment on Febru
14, 1991. These documents were made avail~ ~ to the public i
both the administrative record and an infor ~ion repository
maintained at the u.S. EPA offices in Region 5, Kentwood City
Center and the Kent County Library. The notice of availability
for these documents was published in The Kentwood Advance and
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Gt.and Rapids Press Newspapers on February 13, 1991. A public
comment period on the documents was held from February 20, 1991,
tCI March 21, 1991. In addition, a public meeting was held on
March 6, 1991. At this _eeting, representatives from u.s. EPA
and MDNR answered questions about problems at the site and the
remedial alternatives under consideration. Comments received
during this period are included in this Responsiveness Summary.
C..
SummarY of Comments Received and Aaencv ReSDonses
Ttle public comments regarding the ~entwood Landfill site are
o]~ganized into two categories:
- Summary of comments from the community:
- Summary of comments from the city of ~entwood and ~ent County;
Heiny of the comments below have been paraphrased in order to
effectively summarize them in this document. The Administrative
Rt!cord contains copies of written comments submitted during the
p\wlic comment period and a written transcript of the public
mt!eting held on March 6, 1991, which includes the oral comments
rt!ceived during the formal comment session of that meeting.
No comments were received from the State of Michigan on the
Proposed Plan during the public comment period.
~ommunitv Comments
Several commenters expressed support for the preferred
alternative (Alternative 4) at the public meeting. The majority
of comments received from the community appeared to support
Alternative 4 and no objections were raised in opposition to
Alternative 4. Several other commenters only iterated their
concerns, rather than supporting any particular remedy.
Comments received from the community and responses are listed
below:
1.
Comment One commenter would like more information on the
negotiation process and was concerned that the negotiations
between the Potentially Responsible Parties (PRPs) and the
U.S. EPA will slow down the implementation of, or alter the
selected remedy for the Site.
ReSDonse The law (CERCLA) provides a period of negotiation
between the PRPs for a site and the U.S. EPA for the
implementation of a remedy after the Record of Decision is
signed by the u.S. EPA. This period of negotiation begins
with a 60-day period for the PRPs to present a good faith
offer for the conduct of the remedy, to the u.S. EPA. The
2
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---.--.-.- --
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-
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---
u.s. EPA reviews the offer, against established criteria,
- to judge if the offer is made in good faith. If an offer is
judged to be a good faith offer the negotiation period is
-extended another 60 days. If the negotiations result in
agreement, a legally enforceable written agreement called a
Consent Decree is .iqned by the PRPs and the o. S. EPA. The
Consent Decree require. the PRP. to conduct the remedy Aa
selected and memorialized in the Record of Decision,
according to a schedule, and under the quidance and
oversight of the U.S. EPA.
~e opportunity for a PRP to negotiate an agreement for the
conduct of the design (Remedial Design (RD» and
implementation (Remedial Action (RA» of a remedy is written
into law. This provision in the law allows PRPs to take
financial responsibility for a site and allows the U.S. EPA
to conserve the "Superfund" monies.
The negotiation period lasts a total of 120 days. The U.S.
EPA considers this time period as time well spent
considering the limits of resources in the "Superfund" and
that PRPs are given an opportunity to take responsibility
for a site.
If no good faith offer is received or Consent Decree is
signed for the remedy at a site, the U.S. EPA has a number
of powerful legal options which it can use to compel PRPs to
take responsibility for a site, or U.S. EPA can use the
.Superfund".
2.
Comment One commenter expressed concerns over the quality
of the ground water that her family uses for drinking. The
commenter's home is close to the Site. The commenter
requests that her drinking water well be sampled and
analyzed periodically.
Response The remedy selected for the Site includes periodic
monitoring of residential wells as specified by the U.S.
EPA. The number, location, frequency of sampling and
analyses will be determined by the U.S. EPA to assure
protection of human health.
The sampling and analysis of ground water near the Site
indicates that the Site has not contaminated existing
residential wells. Should contamination that endangers
human health be discovered in residential wells, the U.S.
EPA will use its authority to provide alternate sources of
drinking water to affected residences.
3
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3.
Comment Several comments concerned the commenters'
perceptions of "finger pointing" between different local,
State and Federal agencies and citizens on responsibility
.for the Site.
ReSDonse It should be clear to persons that have followed
the recent events and decisions on this Site that u.s. EPA
has taken its responsibilities concerning this Site very
aeriously. The u.S. Congress delegated very powerful and
broad authority to the u.S. EPA, through CERCLA, to clean-up
aites auch as the Kentwood Landfill aite. This statutory
authority includes holding Potentially Responsible Parties
(PRPs) financially responsible for clean-ups at .ites.
It is important to note that regardless of outcomes
negotiations with PRPs, settlements, etc., the u.S.
initiate and complete a remedy at this site, using
.Superfund" money if necessary.
of
EPA will
4.
Comment One commenter expressed concerns that a more
detailed environmental assessment of the vicinity of the
Site is necessary.
Response An environmental assessment of the Site vicinity
was conducted. At this time, U.S EPA considers the quality
and amount of data 9athered sufficient to select a final
remedy for the Site. The selected remedy includes
monitoring of surface water and other conditions at the
Site. The remedy selected employs active measures that not
only protect human health but also the environment. If
additional information concerning endangerment of the
environment that is not addressed by the selected remedy is
found, the u.S. EPA will examine the information and decide
on a course of action. .
s.
kPmment Several comments were received concerning
installation, as soon as possible, of a fence around the
Kentwood Landfill property to warn and protect persons of
Site threat..
Response The selected remedy includes restricting access to
the Site by various means including fencing and signs.
- II.stallation of fencing will be a priority at the site.
One possibility may be the installation of temporary
fencing and/or signs warning trespassers of dangers on the
Site, until specifications for permanent fencing are
determined.
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L
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6.
.Comment Several comments were received concerning the
preservation of naturally occurring vegetation on the Site,
the planting of indigenous plants other than grasses on the
landfill caps, and volunteer work to save plants at the
Site.
ResDonse Improvements to the caps on top to the landfills
will result in some destruction of the vegetation in place.
Thi. is unavoidable during the activity to ensure that the
cap complies with regulations for the protection of human
health. Grasses are planted on landfill covers to prevent
erosion of the cover The types of grasses used for
vegetative cover are~imilar to those used in highway
construction. The grasses in these seed mixes are selected
for drought resistance, root depth, and minimal maintenance.
Shallow rooting vegetation is planted because vegetation
that roots deep into the cover creates pathways for waste or
wastes generated gases to migrate uncontrolled out of the
landfill.
7.
Comment One comment was received proposing the plantation
of evergreens or hedges to screen noise and view of the
Site.
ResDonse The proposal to use vegetative barriers to noise
and views will be evaluated during the Remedial Design phase
of the project.
8.
Comment One commenter had concerns that the proposed
locati~n of ground-water extraction well was within a
habitat for an indigenous amphibian known as "the spring
peeper", and that this location might disturb the
creatures' habitat.
ResDonse The locations of ground-water extractions wells
will be decided upon during the Remedial Design phase of
this project. Adverse impacts of any remedy components to
biota will be minimized to the extent possible.
9.
Comment A comment was received that concerned the future
uses of land along the northern boundary of the ~entwood
Landfill ~-~perty. This property is currently owned by a
land deve~ ~.r and the developer has plans to use the land
for reside~~ial development.
5
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Response The selected remedy includes use of institutional
-controls such as deed restrictions to protect human health
and the environment. Institutional Controls are necessary
to .aintain integrity of the caps and prevent future use of
contaminated ground water.
10.
Comment One commenter suggested that ground-water
extraction wells be located as close to the site as possible
to obtain maximum results and asked whether the extraction
well. make noise.
Response The location of ground-water extraction wells will
be determined during the Remedial Design phase of the
project. The wells will be placed where they are most
efficient in collecting contaminated ground-water for
treatment. Ground-water extraction wells of the type used
for these purposes generally do not make intrusive noise.
11.
Comment A comment was received requesting that future
investors/buyers of contaminated property be warned of the
presence of contamination through deed restrictions and
development alerts.
Response The selected remedy includes the employment of
deed restrictions.
12.
Comment A commenter noted that a ditch along the north
boundary contains leachate and leaks at the northwest corner
of the property. The commenter suggested that this
situation needs to be addressed soon.
Response The remedial investigation conducted to determine
conditions a£ the site found that some leachate is escaping
the landfill to the north. The remedy selected will collect
and treat leachate and will prevent further releases. The
remedy al.o includes continued monitoring of site
condition.. The U.5. EPA considers monitoring of the site
conditions as a priority and intends to employ the
monitoring as soon as possible. If conditions on the
release of leachate chanqe and warrant early action to
protect human health and the environment
u.s. EPA will use its authority to conduct necessary action.
6
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~..~
13.
Comment A comment was received asking how we will know that
.the job is ~inished.
ReSDonse The selected remedy is estimated to clean-up
contaminated ground water to protective levels in 9 years.
~e progress of the ground-water remediation will be
.onitored closely during the years required to reach
protective levels. Other conditions at the site will also
be 80nitored. The ground-water clean-up program will
continue until the remediation standards have been met,
longer than the estimated 9 years 1~ necessary. Because
hazardous substances will be left on-site, within the
improved landfills, 0.5. EPA is required by law to review
conditions at the landf.ll at least every ~ive years after
remediation goals are met. The ground water will be
.onitored for at least 30 years after the remediation goals
~or the ground-water clean-up are met. U.S. EPA will
continue to monitor the effectiveness of the remedy for a
long time.
14. Comment A comment was received requesting that one person
be identified who is responsible for the addressing public
concerns for the site.
ResDonse
The u.S. EPA contact for this site is:
Mr. Phillip Schutte
Community Relations Coordinator
Office of Public Affairs
(SPA-14)
u.S. EPA, Region 5
230 S. Dearborn St.
Chicago, Illinois 60604
(800) 621-8431
(312) 353-866-8515.
15.
Comment One comment received requested the locations of
.ethane releases that are outside of the boundary of the
~.ntwood Landfill property.
ResDonse During the remedial investigation no releases of
methane gas have been found in areas outside of the
Kentwood Landfill property.
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16.
17.
--.-- --
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Comment One commenter had a number of suggestions
concerning community involvement on issues concerning
.~entwood Landfill site including volunteer activities
aite, fund-raising, education of the community, etc.
ReSDonse The u.s. EPA encourages community involvement
concerning the Kentwood Landfill site. Representatives of
the U.S. EPA are available to participate in community
meetings should significant interest in such participation
be expressed by the community. The u.s. EPA has a number of
resources that can be accessed by the community for
community education.
the
on the
Comment Several comments concerning the effects of the
.elected remedy on the environment were received. These
concerns included the amount of noise created by equipment
including ground-water extraction wells, disruption of
wildlife, disruption of vegetation at the Site, and effects
on wetlands in the vicinity of the Site.
ReSDonse The purpose of conducting a remedy for the site is
to protect human health and the environment. During the
conduct of the remedy, laws protecting human health and the
environment must be adhered to by parties doing the work.
This includes state and Federal regulations concerning noise
pollution, siltation of surface water, protection of
wetlands and others.
tomments from Kent County and the City of Kentwood
Kent County and the City of Kentwood provided comments on the
Proposed Plan through oral and written comments written by
elected officials, appointed officials, and consultants.
Significant comm~ts from this group generally concerned the
appropriateness of the preferred alternative compared to the
risks posed by the site.
18.
Comment A commenter stated that in his opinion (a)
conditions present on and around the site are in no way as
hazardous to persons in the vicinity of the landfill as the
u.s. EPA maintains, (b) circumstances by which significant
human exposures to site contaminants are very improbable,
and (c) the u.s. EPA'. representation that "actual or
threatened releases of hazardous substances from this site,
if not addressed by the preferred alternative or one of the
other active measures considered, may present an imminent
and substantial endangerment to public health, welfare, or
the environment" was greatly over-stating the risks posed by
the site.
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---
Another commenter raised similar comments on the
-ju.tification of conducting a remedial action at this .ite.
Response The 0.5. EPA disagrees with the commenter's
opinion. The U.5. EPA has characterized risks posed by the
aite accurately in public documents, including the Proposea
Plan.
The 0.5. EPA assesses the risks posed by a .ite by
conducting a baseline risk assessment. The baseline risk
assessment assumes no corrective action will take place and
that no site-use restrictions or institutional controls such
a. fencing, qround-water use restriction. 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 includes an evaluation of
lifetime excess cancer risks posea by a site. Lifetime
excess cancer risks are cancer risks posea by the site which
are in addition to those normally posed to a population.
Where the baseline risk assessment indicates that a
cumulative site risk to an inaividual using reasonable
.aximum exposure assumptions for either current or future
land use exceeas the 1 X 10-4 (1 in 10000) lifetime excess
cancer risk ena of the risk range, a site is determinea to
pose an unacceptable risk to human health and action unaer
CERCLA is warrantea.
The U.S. EPA's determination that a CERCLA clean-up at this
site is warranted is basea in part, but not limitea to, the
following. The landfills at the site have contaminated
qround water_within and outside of the boundary of the
lanafill property. The 0.5. EPA determined that since the
Site is in a residential area and since a land developer
owns land that contains contaminated qround water
immediately to the north, it is reasonable to assume that
the land that exists over the contaminated ground water at
this .ite could be developed for residential use. This
residential land use scenario includes the conservative, yet
r.asonable assumption that ground water would be used for
drinking and bathing. The baseline risk assessment
estimated that the excess lifetime cancer risk posed by
residential consumption of the contaminated ground water
alone va. 1.7 X 10-2 (17 in 1000). 1.7 X 10-2 is a greater
risk than 1 X 10-4, that means that the site poses an
~nacceptable risk and warrants remediation under CERCLA.
9
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19.
. .
-- -- --
Ba.ed on the Baseline Risk Assessment, the U.S. EPA has
determined that the Site may pose imminent and substantial
-endangerment of human health of the environment if the Site
_is not addressed by the selected remedy.
Comment A commenter noted that leachate releases to the
land surface and ground water as well aa the concentration
of hazardous aubstances had been reduced in the past years,
endangerment of the public had therefore already peaked and
the 8aqnitude of a response should therefore be less than
that proposed in the preferred alternative.
ReSDonse U. S. EPA disagrees, as discussed in the comment
above, a baseline risk assessment of current and future
risks posed by the Site indicates that endangerment of human
health or the environment will continue if action at the
Site is not taken. Based on data collected concerning the
Site and evaluation of that data against U.S. EPA's
criteria, u.S. EPA has identified the preferred alternative
as an appropriate remedy for the Site.
20.
Comment A commenter stated that construction of fencing
around the Site itself is probably the most appropriate
action proposed for the site. The commenter further stated
that regulations which prevent installation of drinking
water wells into areas of known ground water contamination
would prevent human exposure.
ReSDonse Restricting access to Site contaminants by
erecting fences, posting signs and promulgating regulations
preventing drinking water well installation as well as deed
restrictions are all components of the selected remedy for
the Site. These components are classified as institutional
controls. The National oil and Hazardous Substances
Pollution Contingency Plan (NCP) is the body of regulations
that govern responses under CERCLA. The NCP states that
U.S. EPA expects to use institutional controls to supplement
engineering controls as appropriate for ahort- and long-term
management to prevent or limit exposure to hazardous
aubatances at sites. The NCP clearly states that the use of
institutional controls ahall not substitute for active
response measure as the sole remedy unless such active
measures are determined not to be practicable (Title 40 of
the Code of Federal Regulation (40 CFR) Section 300.430
(a)(l)(iii)(D».
Based on data and studies of the Site, U.S. EPA has
determined that active measures are practicable for
Site. These active measures include extracting and
contaminated ground water.
the
treating
10
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- - - -
The U.S. EPA does not normally substitute institutional
controls for active measures, when active measures are
practicable, because institutional controls can not be
considered permanent and do nothing to prevent non-human
.pecies exposure to contaminants.
COmment One commenter atated that Alternative 3 vas
identical to preferred alternative (Alternative '4) with the
exception that Alternative '3 limited the installation of
ground-water extraction wells to vithin the boundary of the
Xentwood Landfill Property. The co~enter a180 stated that
the feasibility study indicated that Alternative '3 would
8180 clean-up the contaminated ground water in the vicinity
of the site.
ResDonse The u.s. EPA believes that this comment relates to
how a selection was made between Alternative '3 and
Alternative '4.
As described in more detail in the Record of Decision, u.s.
EPA found the selected alternative, Alternative '4, provided
the best balance of trade-offs as evaluated against the nine
criteria u.s. EPA uses to make remedy selections. The basis
for V.S. EPA's selection of Alternative '4 includes, but is
not limited to, information presented in the feasibility
study report. As written in the Feasibility study Report,
Alternative '4 is estimated to reach remediation standards
for ground water in 9 years: Alternative '3 is estimated to
reach the standards in 19 years. Clearly, Alternative 4 is
estimated to achieve the protective ground-water remediation
standards in less than half the time estimated for
Alternative t.3.
Remedy alternatives which provide more rapid attainment of
protective remediation goals are preferred.
Tbe .elected remedy, Alternative '4, provides u.s. EPA the
flexibility of installation of ground-water extraction wells
in areas where the wells will be most effective.
22.
~~~ One commenter had concerns that the Alternative f4
wo- ~d not remediate ground water faster than Alternative '3.
Response The feasibility study report estimated that
Alternative '4 would attain remediation standards for ground
-water in 9 years: and that Alternative '3 would attain the
standards in 19 years. Clearly, Alternative 4 is estimated
to achieve the protective ground-water remediation
standards in less than half the time estimated for
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Alternative .3.
_In order to protect human health and the environment, the
--V.S. EPA has selected a remedy, Alternative .4, that allows
-for installation of ground-water extraction wells in
locations that will attain ground-water remediation
standards as quickly as possible.
23.
Comment One commenter pointed out that the feasibility
study report recommended that ground-water extraction wells
installed outside of the Kentwood Landfill property would be
installed after wells installed within the property boundary
were evaluated. Further, that the feasibility study report
recommended proper evaluation of the effectiveness of the
wells on the property prior to installation of wells off of
the property.
ReSDonse The exact location, depth, design, pumping rate,
timing of installation, etc. of the ground-water extraction
wells and all other. value engineering decisions will be made
during the Remedial Design stage of this project.
Recommendations, estimates, etc. made during the feasibility
study phase of a project are to provide sufficient
preliminary information for the u.s. EPA to select a type of
remedy for a site. The selection of a remedy is
memorialized in the Record of Decision. The Remedial Design
is used to plan in detail how the selected remedy will be
implemented in accordance with the Record of Decision.
24.
Comment One commenter indicated that installation of wells
outside of the Kentwood Landfill property without evaluation
of wells installed within the property boundary may draw
higher levels of ground-water contaminants into less
contaminated-areas thus requiring longer to meet the
remediation standards.
Response During the Remedial Design phase of the project
the placement of wells will be designed to minimize this
possibility. During the Remedial Action phase the actual
performance of the extraction of ground water will be
8onitored and adjustments will be made should undesirable
effects be discovered.
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25.
~omment One comment received indicated that both
-Alternative '3 and '4 attain the protective ground water
remediation standards for ground water.
Re$oonse The feasibility 8tudy report indicates that both
Alternatives '3 and '4 attain remediation standards. The
Record of Decision a180 indicates that the threshold
criteria of Overall Protection of Human Health and the
Environment is satisfied by both Alternative '3 and '4.
Overall Protection of Suman Health and the Environment is
only one of nine criteria that the 0.5. EPA uses to make a
.election of a remedy. As detailed in the Record of
Deci8ion, 0.5. EPA selected a remedy .that provides the best
balance of "trade-offs- between all nine criteria.
26.
Comment One commenter requested clarification on whether
the proposed caps over the landfills are to comply with
proposed or existing Michigan Act 641 requirements.
Resoonse The caps on the landfills shall comply with MI.
Act 641 as promulgated (signed into law) by the signature
date of the Declaration for the Record of Decision.
27.
Comment One commenter requested clarification on whether
pretreatment of extracted leachate and contaminated ground
water to be accepted by the POTW is necessary.
ResDonse The remedy selected requires compliance with all
applicable or relevant and appropriate requirements. This
includes any pretreatment requirements of an accepting POTW.
The Record of Decision also indicates that if, for any
reason, trea~ment of these liquids can not be technically or
lega1ly done by a POTW, including but not limited to, non-
attainment. of POTW pretreatment requirements, these liquids
shall be completely treated on-site.
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