United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R05-87/057
September 1987
&EPA
Superfund
Record of Decision:
Northern Engraving, Wl
-------
'"
. .
TECHNICAL REPORT DATA
fPltat' 'tad 'ffrtffJCIIOffS Off Ihl ""'"' tH{fN' 'O,.,,,I'lIfffl
,. "I'O"T NO. 12. 3. "'ICIII"I"'1"5 ACCISS,OI\o "'"0
~PA/ROD/R05-87/057
.. TITLI ANO S"'ITITLI . 5.1111'01111' CATI
SUPERFUND RECORD OF DECISION SeDtember 28. 1987
~orthern Engraving, WI 8. II'IIIIIIO"'MING O"'CiANllA1'ION COOl
Pirst Remedial Action - Final
7. A",THO"'SI e. PllillIOIIIMING OlllCiANllATIO'" "'lpOI'IT ."0
I. """O"""INQ OlllGANIZATION NAM. ANO AOOI'I'SS '.0. II'I'IOGI'IAM II.IMINT 1\00.
" I;QNT"A~T/c;;"ANT NO.
12. S'ONSOlilING AGeNCV NAM. ANO AOOI'IISS 13. TV". 011 ""'OlilT ANO "'111'00 COl/I"'IO
J.S. Environmental Protection Agency Final ROD Report
401 M Street, S.W. 1.. S"ONSOIIIING AGINCV COOl
rlashington, D.C. 20460 800/00
15. SU"!.I"".NTA"" NOTIS
1e. AAT..ACT
The Northern Engraving Corporation (NEC), located in Sparta, Wisconsin, presently
owns and operates a manufacturing facility at the site, which produces metal name
plates, dials and decorative trim for the automotive industry. The majority of the.
land .within the Sparta area is zoned for general agriculture which includes livestock
'aising, .nursery, greenhouse and poultry farming. Four separate areas of
~ontamination at the NEC facility have been identified as potential sources of soil,
ground water and surface water contamination. They include the sludge lagoon, seepage
pit, sludge dump site and lagoon drainage ditch. The chemical constituents found in
these areas are from past wastewater treatment and disposal practices employed at the
site. Since the 1960s waste rinse waters and by-products of the metal finishing
process have been treated onsite. An onsite wastewater treatment lagoon was installed
in 1967. Rinse water from the plant was collected and treated with sodium hydroxide
for precipitation to metal hydroxide solids. The treated rinse water was discharged
to the sludge lagoon to allow solids to settle. The treated lagoon effluent was
discharged to the LaCrosse River by way of a storm drainage ditch. Between 1968 and
1976 the sludge lagoon accumulated solids from the treated wastewater. On two
occassions, sludge was removed from the lagoon and landfilled in an onsite dump area.
The sludge lagoon was eventually removed from service in 1980, by which time two to
(~~~ ".... ..:I C:,.., "''''.. \
n. Itl" WCIIIC8 AND DOC"'''''I...T ANAL"'SI'
~. DIIC'U"D'" ".'OIN1',II'I"I/O'IN INOIO TUt""S C. COSA TI F telc1JGroup
Record of Decision
Northern Engraving, WI
First Remedial Action - Final
Contaminated Media: gw, soil, sw
Key contaminants: inorganics, metals,
TCE
..... O'STIII'IUTION STATIMINT II. SICUI'IITY c:~ss I nil' Rtpo,,/ 21. NO, 0' "AGIS
None 60
1 20. S.CUIIIITV CLASS I nil' POI" 22 ""'I C!
None
I'. ,- 2220-1 (R.... .-77)
"..""0"" co' "'0" ,.0..0.......
-------
EPA/ROD/R05-87/057
Northern Engraving, WI
First Remedial Action - Final
16.
ABSTRACT (continued)
sludge had accumulated on the bottom of the lagoon .and presently remains. An onsite
seepage pit was employed to neutralize spent acid waste. It was removed from service,
filled with approximately five feet of clean fill and graded in 1981. A new above
onsite ground wastewater treatment system was installed in 1976 and modified in 1984 to
meet more stringent State effluent standards. Approximately 900 yd3 of sludge is
contaminated with phosphorous, aluminum, cadmium, copper, nickel, iron and fluoride.
The drainage ditch is contaminated with fluoride, aluminum, chromium and copper; the
seepage pit is contaminated with trichloroethylene (TCE); and ground water is
contaminated with copper, nickel and zinc.
The selected remedial action for this site includes: excavation and onsite
solidification of approximately 4,400 yd3 of sludge and soil; installation of a RCRA
cover atop the lagoon; application of access and deed restriction to the seepage pit
property; and ground water monitoring. The estimated total capital cost for this
remedial action is $295,000 with annual O&M of $16,000. .
~
J
-------
;;
I
\
,
RECORD OF DECISION
REMEDIAL ALTERNATIVE SELECTION
i.
Site Name and Location
Northern Engraving Corporation (NEC)
803 South Black River Street
Sparta. Wisconsin 54656
I I .
Statement of Purpose
This decision document represents the selected remedial action
for the NEC site developed in accordance with the Comprehensive
Environmental Response. Compensation. and Liability Act of 1980.
as amended by the Superfund Amendments and Rpauthorization Act
of 1986; and the National Contingency Plan, 40 CFR Part 300.
November 20. 1985.
The State of Wisconsin has concurred on the selected remedy.
I II.
Statement of Basis
This decision is based upon the Administrative Record which
includes the remedial' investigation report and feasibility study,
and other related documents. The attached index to the adminis-
trative record identifies the complete list of items upon which
the selection of rem~dy is based.
JV.
,
Description of Che Selected. Remedies
A. Source Control
1 .
Excavate and place contaminated materials from the
drainage ditch and sludge dump site in the sludge
lagoon for solidification.
All contaminated materials in the sludge lagoon
will be solidified, and the lagoon will be provided
a RCRA cover and monitored for proper closure.
2.
B.
Restrict access and apply deed restrictions to the
seepage pit property.
Management of Migration
3.
Ground water contamination will be regulated.and
monitored through the use of alternate concentration
limits (ACLs) to be applied downgrad1ent of the sludge
lagoon and the seepage pit.
.
,.
-------
. .
\
. ,
c.
Operation and Maintenance
The cover over the sludge lagoon and the seepa~e pit
will be routinely inspected and monitored. Semi-annual
ground water sampling and analyses at compliance monitor-
ing wells will be conducted. .
i
v.
Declaration
The selected remedy is protective of human health and the
environment, attains Federal and State requirements that are
applicable or relevant and appr~priate, and is cost-effective.
This remedy satisfies the preference. for treatment that reduces
toxicity, mobility, or volume as a pri~cipal element. Finally,
it is determined that this remedy utilizes permanent solutions
and alternative treatment technologies to the maximum extent
practicable.
~~""t1
OAT
/in
. Adamkus
Administrator
,
.
\J
\J
.
.-
-------
..
.
,
(
SUl11mary of Remedial Alternative Selectioni
Northern Engraving Corporation'
Sparta, Wisconsin
I .
Site Location and Description
The Northern Engraving Corporation (NEC) site is located in
Sparta, Wisconsin at 803 South Black River Street (Figure 1).
NEC presently owns and operates a manufacturing facility at the
site, which produces l11etalname plates and dials for the automotive
industry. Sparta is a moderately sized rural community (population
6,800) in western Wisconsin that lies approximately 25 miles due
east of LaCrosse and 150 miles northwest of Madison.
The NEC facility is located on the south edge periphery of the
residential and business areas of Sparta. The LaCrosse River
constitutes the southern boundry of the site and portions of the
site lie within the river's flood plain (Figure 2). The closest
city residence is approximately one-quarter mile away from the
site. Within the confines of the city limits, potable water is..
obt~1nert primarily through a municipal distribution system that
draws water from three production well fields. The city well to
the site is located at the "west well field" which lies approxil11ately
4,000 feet from the NEC facility. The Sparta area is primarily
served by a sandstone aquifer in the Trempealeau-B1ack River.
Basin. The municipal wells range in depth from 105 to 260 feet.
The sandstone aquifer yields between 400 to 700 gallons per
minute at these wells.
o'
Most residences in the city obtain water from the city distribution
system. Seven residences have private wells, the closest of which
is located approximately 2,500 feet from t~e NEC facility. All
private wells within a three mile radius of the NEC facility are
completed in the sandstone aquifer. Figure 3 identifies the
location of the city's municipal well fields and private water
supplies.
The predominant land use patterns in the Sparta area are agricul-
tura1, residential, COl11mercial an'd industrial. The majority of
the land county-wide is zoned for general agriculture, which
includes livestock raising, nursery, greenhouse and poultry
farl11ing. .
/
Four separate areas of contal11ination on the NEC facility have been
identified as potential sources of soil, ground water, and surface
water conta~ination. These areas are identified in Figure 4 and
include the sludge lagoon, seepage pit, sludge dump site, and
lagoon drainage ditch. The chemical constituents found in these
contamination areas were the result of past wastewater treatment
and disposal practices emp10y~d at the site.. In September, 198~,
NEC was placed on the Superfund National Priorities List based on
its score calculated by the Hazardous Ranking System~ .
-------
'!'
NORTHERN ENGRAVING CORP.
Sparta,
Wisconsin
FI r;IjRF. 1
-.-
'.;
. f
--I
. j
. .! .. .
- -- . - 0
'11',
''';'''';
. .\
,". . - 'r7I'
. ..'."-.;
- - ~_._.
.. .
r-- -..
.,-
.6-:
. -,
.
. .
, 0 .
. . f 7'1;
: : , .:.. 2
. ."" ~ .. .- =.-.:. J-~:". .~..~-=-
2 - . . .. . ~,. .
.
,
..- ..~.~ :--.......-.. .- - --- ----... -..
J J
. oj c,
'. _,..0 ,-' .'~~' l.
. --'~'-"
. I
~,__-1'
.:25 \~ o~'
...~~ ~. - l ~
... .~.- .
: . .. .. I
-~ .:-:.":' .:.- ..-.c - ..
\J
\!
--
SCALE 1: 31250
LOCATION MAP
-------
,
-~-
I
I
r
,
I
~
:
."
~I
~I
.0
rrJ
N
WA'ttWAna
fltUfMt:Nf ..k.DING
. .
(.-.... -
" -'..
. "..
. . ..
:0
STEL TING .
ST.
..:
.
, I
L.LJ' M.,
I ,.
U
BELMONT '.. . AVE.
~ n (....-. I
1 ~ L~:.::d
I L L_-
BLACK RIVER sr.
.
I
~
~
,
:..
"...
.......,
.
i
NORTHERN
ENGRAVING
. CORP.
nJ
. ROOD PLAIN
NORTHERN ENGRAVING CORP.
SPARTA, WISCONSIN
I
~
,
.
-------
PRIV ATE
WATER SUPPLY
WEST
WELL FIELD
---.-.---.-.-.-- ,
I .
I
I
I
,
~
.."
0-4
:..,
c:
:-0
!TI
w
I .
~0-
I
NOTES:
-
1. CLOSEST RESIDENCE ON CITY WATER-: .
~OO'
AOo'
SCALI:
PRIVATE i
WATER SUPPLvi
I .-' ~
! r----'------ \
L._-----_J
MUNICIPAL WELL FIELDS &
PRIV ATE WATER SUPPLIES
NORTHERN . J;,NGRAVING , CORP.
SPARTA,- WISCONSIN
.
-------
o
r---
I
L,
.
.
. ..",", ..---. ,--... ., ~:--;::a ,
' - " ... , \
"".. c...----- 'I ',:, " ~ \ \, ,.
'\, "', ~, ~ \ .: :J ,-,--..., "
.) I I ) i \ " : J \ (",,:
:,' l " , ,', '. ,.o-~"- . ,"
-. " ., '. ..... ....... t
~~ \ " , , ....." ,
{" i: ",.. \ \ :' I
'.. I I It- -. l " " I ,
\ ... ,'\: '-.. ::~ " \ " \. - "'- ",
.-._--..-'70_____.~ '-, \'~' II:. , \. ""',. .,..,.1 ,
I , ~ ,'" .~ ---- ,
.. ., '. ----, " \ .. ')' ,"'1fI' "
/~-', . - " ,'- \... iJ \ \ (.-': "
" : '......... r.s..../ '-: "'''''..., " \ , : \
(I'" : '. \. . \.. '-I \: '.
"--..::::.'_'10..._- ----,-,'"---- --':' '.IIUNICNL UNITAIIY " ", ' , ',: '\
------- :to..- - . .r'''£ATN[NT , . .
. -'-- 0'-- \ .. PLANT --._u..--...--', I. ~-- - ,IJ \ 775
~ ' . ,,' J ," ,'. /',''.'"",_", ...... I
. r:'!~:m ,: CD /A:::;:m:.::~:~/, 7 L ~/ ~\~~',1 ,-\ ",; \'-) /
' l' ' 'JO-.' I -, , ';)'')' , " '"
1\--"0" ~ 0 0 ..._------.._.~{,' . "~I' ~..... '..-..' ,~ /"/' :'
-.-..." ~ ---e."" . "0 '. -, ",'" 'i
,\~~~= --V ,: ~~~~/ ( '----,! (=::"..-,,-....,1 \
" fi~ I - - - --- -. - ----.::.. -~ '- :/ " '''-''''''
" ..,. " ~ . "",
. WtSfrwAT£1t lfOItM IIINOF' I ' ,.,
'. TU.ATM[NJ LD - -- P'_T~" 'I :-'. I '....' ,
'. -~--.:... - - '. SB----- . UGOON DllAlN. I! : ,..... '711 \.
\. '7;0 . \ '...., :,.;,';......:, DITCH '",. ,. ,/ ,-,--"," ., '
-,~--- ,~~~-.- --'~;'i;~ /i _.j/ ..:. A\~~ "
. ," ,.:' '=,' "'.. - - C::\"""',- --..-' ,- -- \, .
','. '.....'. - - --;,-.If ,.., I. "oJ ~,
. ;',t.;';~,;i '. U U!I ~.\ :' .J)./ .. '\
L¥{~~~~T~{i~' ~;j(),t~bii'-V . (, \'\"'\I? \"!
. "i""1.' f.NGRAVING .11;, ..:,'.' , .,./> ..;,.~., " ~A'" jjjj1. '!!!:!NOIIY 1,"0 1'\ \,' "
.' r'~\~~i~~~~~;;,i:~ (~~~-.-,~~--~,~i,:.~.\,",:':~~~'~,'\\,,- _./,':~, 'ri'\~,~\\(:"\
r':f; \...' ":"'" -'<1 t~ \
,
'.;T' :... .
SrCtTIN6 .
r -.'-
. ,
\ '-",.....
sr.
,
. ,
. I
Lool n~..
---1' .
.1 I:
LuJ :
Il£tAOn
roo -, ...
_.~
I ( d
L- "'''..:-'
Iu
~
,
,
r
L..
BLACK RIVER
I
'....,
.
"'."'.
,
I
':,',""
.; : ~'.
$T.
.. ....
o
I
SITE PLAN
NORTHERN ENOA VINO CORP.
SPART A. WISCONSIN
200
t ~
SCALE
400
,
."
......
..,
C
:"d
:TI
~
.
-------
. t
..
-2-
II.
Site Background
.
f
.
1 .
History of Site
The NEC Sparta facility has been in operation since the 1.960's
and serve as the corporate headquarters for the company. As
stated ahove, NEC primarily serves the automotive industry through
production of name plates, dials and decorative trim. The
manufacturing process involves metal finishing operations that
includes anodizing, chemical etching and chromate conversion coating.
Waste rinse waters that resulted from the metal finishing process
were and are presently treated on-site at the facility. A wastewater
treatment lagoon was installed at the facility in 1967. Rinse
water from the plant was collected and treated with sodium hydroxide
for precipitation of metal hydroxide solids. The treated rinse
water was discharged to what is referred to as the sludge lagoon
to allow solids to settle. The treated effluent from the lagoon
was conveyed by way of a storm runoff ditch to the LaCrosse River.
Between the period from 1968 to 1976. the sludge lagoon accumula~d
solids from the treated wastewater. On two occassions. sludge'
was removed from the lagoon and landfilled in an on-site dump
area. The sludge lagoon was ~ventually removed from se'rvic~ in
1980. by which time, two to four feet of metal hydroxide sludge
had accumulated on the bottom of the lagoon, and presently remains.'
A seepage pit on-site was employed to neutralize spent acid waste;
the pit was lined wft-h limestone for neutralization. The seepage
pit was removed from service and filled and graded in 1981.
Approximately fifteen feet of clean fill lies atop the bottom of
the pit.
A ~ew ahove ground wastewater treatment system was installed
on-site by NEC in 1976. The system was modified in 1984 to meet
more stringent state effluent standards.
It
2.
Current Site Status
The sit e ex h i bit s f 0 u r d i s c r e t e a,1." e a s 0 f con tam i n a t ion 0 n - sit e t hat
are believed to be impacting or threatening to impact ground water
and surface water. These areas have been identified as the
sludge lagoon. seepage pit. sludge dump area. and the drainage
ditch. .
v
.
The sludge lagoon contains approximately 900 cubic yards of
sludge. The sludge is contaminated primarily with metal hydroxides
consisting of phosphorous. aluminum. cadmium, copper, nickel.
iron and fluoride. The drainage ditch, which was used to convey
effluent from the sludge lagoon to a storm runoff ditch, shows
elevated levels of fluoride, aluminum. chromium and copper.
-------
-.
-3-
The sludge dump was utilized on two occasions to dispose of
approximately 930 cubic yards of sludge from the sludge lagoon.
The sludge dump was removed from service in 1980 and was .eventually
backfil led with native soil and vegetated. Down gradient monitor-
ing wells have not detected contaminants attributable to the sludge
dump. The same metal hydroxides that are found in the sludge
lagoon are also evident in the sludges of the sludge dump.
The seepage pit was used to dispose of rinses and dye solutions
containing concentrated aluminum and fluoride. Paint residues
fro~ ink well operations. were also discharged to the seepage pit.
Ground water monitoring within the seepate. pit and downgradient
from the seepage pit and sludge lagoon have detected trace amounts
of volatile organics, such as 1, 1, I-trichloroethane; 1, 1-
dich10roethane; 1, 2-dich10roethylene; vinyl chloride; and
trichloroethylene. Typically, the majority of the organics were
below 100 parts per billion (ppb), except for trichloroethylene
where concpntrations were as high as 670 ppb. Elevated levels of
heavy metals such as copper, nickel and .zinc were also detected
in downgradient monitoring wells.
..
3.
Site Hydrology
The NEC facility is situated atop approximately 75 feet of alluvial
deposits consisting of fine to medium grain sand. The alluvial
sediments resulted from depositional events of earlier stages of
the LaCrosse River. Underlyin~ the alluvial deposits is the St.
Lawrence Formation,~a Cambrian age sandstone.
,;
Ground water at the facility occurs at depths from between 2.5
to 11 feet below grade. Ground water direction trends towards
the LaCrosse River, where it eventually discharges (Figure 5).
A vertical grad'ie.nt exists between the bedrock water elevation
and the water table elevation. The vertical conponent of ground
water flow results from the head differential between the surround-
ing higher elevations where the sandstone is recharged and the low
lying valley at the facility where ground water discharges (Figure
6). Consequently, contamination of the alluvial deposits should
theoretically not move downward into the sandstone. formation.
Rising head tests undertaken at the site have determined permeabil-
ity in the alluvial deposits to range between 4.17 x 10-3 to 1.56 x
10-2 cm/sec. Velocity of ground water was calculated to move
between .43 and 1.6 feet per day.
4.
Public Health Impact
In its current state, the NEC site presents little threat to the
environment or to public health. The endangerment assessment (EA).
-------
FIr,"D~ c;
j.
.
..'1'
"
-,
I
..----
i F~", ,
~ It! ,-,
:: p.:;! !
.. ,--",,"'. ....-", ,
2j/~
-~".__..,..,.
.-........
i ..
....__0. a r.
i ,'I
..-' i
,
,
,."
I ..
..
..
/---'"
"I J
\ -.f'
"
//
.-/
.-'-
.-'
,.-
,
.-
,
,
.-'
.-
.-'
.-'-
.-'-
.;
i,
. -j
L..
!
o
It
J '
.
I, "ll. ~tl.:;.I;t n. it
:. ' ~, U~lj~: "~:: ~ '," ~ I
;.' ~~:;~ "+~'Y"f+ F'
~:.~ ~:I' t';:, :,~~I~~ ',if
.. ,.,,' .. I !.
-------
,..
.....
~
.;u -
ITI
.:n
.. NORTH
BEAVER CREEK
...,
.
..
HYDROGEOLOGIC CONDITiONS IN THE SPARTA AREA
-------
-4-
analyzed a variety of exposure scenarios through variqus media to
quantify the risks to publc health and welfare. Exposures were
based on potential contact with contaminated sludge, soil, or
ground water. The exposure routes examined were ingestion of
ground water, dermal absorbtion and ingestion of soil and sludge,
and dermal adsorbtion of surface water and river sedime~ts resulting.
from recreational activities. The EA concluded that the total
incremental cancer risks related to ground water ingestion would
exceed the 1 x 10-6 value for chemical carcinogens. However,
the worst case exposure scenario used to establish the cancer
risk value called for the consumption of two liters/day of ground
water from the most highly contaminated monitoring well. Due to
the unlikely event of this exposure and the absence of private,
industrial or municipal water wells threatened by the contaminationp
ground water contamination is considered to present virtually
no exposure risk.
nirect human exposure to contaminated soil in the "seepage pit"
is considered remote due to the existence of 15 feet of soil fill
over the pit. The contaminated soils at the bottom of the pit
contain elevated levels of fluoride and copper, and may a,lso be .
source of volatile organic compounds (VOCs). The only realistic
threat from the seepage pit is the potential of ground water
contamination.
~ontaminated soil and sludge in the "sludge dump area" is buried
beneath two feet of clean soil. Currently, no ground water
contamination has be~n attributed to the dump. Elevated levels
of fluoride have be~ndetected in soils at the dump, however~ due
~o the two foot cover of clean fill, the possibility of human
exposure is remote.
Potential hu~an health risks do exist from direct contact to
contaminated soils in the "drainage ditch". Elevated levels of
fluoride, copper, zinc, and nickel have been detected in the
surface soils of the ditch.
~
Contaminated sludge (exposed) in the "sludge lagoon" also presents
a potential human health risk through direct contact. Elevated
levels of fluoride, copper, and njckel exist in surface sludges.
The LaCrosse River water exhibited no contaminants in excess of
any surface water quality criteria, with the exception of zinc
which meets the chronic toxicity criteria. However, the background
levels of zinc in the river also appear to exist at the chronic
toxicity criteria level. Trace amounts of trichloroethylene,
fluoride, and zinc were detected in river water samples taken
upstream and downstream from the facility. The EA states that
inconclusive differences exist between the upstream and the
downstream concentrations. River sediments revealed elevated
levels of metals in downstream sanples. The EA states ihat the
lev~ls of contamination in the. sediments present no potential.
risks to aquatic species. .
v
-------
-5-
II 1.
Enforcement
. .
;
.
Qn September 10. 1985. the U.S. EPA Re~ional Administrat~r for
Region V signed an administrative Consent Order (Order) with NEC
that stipulates the undertaking of a remedial investigation (RI)
and feasibility study (FS). and subsequent rem~dial action by
NEC. As part of the RI. the Order required that an endangerment
assessment be completed by NEC to determine the actual or potential
harm presented by the site to public health. welfare or the
environment.
The Order. requires that NEC shall control conditions at the site
which could potentially endanger health. welfare. or the environ-
ment and undertake the specific activities set forth in the
Order. These activities include performance of a RI and FS and
implementation of the recommende~ remedy for the site. The Order
provides that all work plans. reports. an~ schedules necessary
for the implementation of the selected remedy shall be made an
integral and enforceable part of the Order. The agreement to
conduct the remedial design and. remectial action at the site is .
embodied in a CERCLA 106 Order. which does not require entering
into a consent decree or the issuance of special notice l~tters.
I V .
Community Relations
The signed Consent Order (Order) for undertaking the RIfFS and
selected remedial measures went out for public comment in September,
198!). No comments we"re received on the Order at the end of the
thirty date day period. the Order became effective thereafter.
The NEC site has generated little public interest or media
attention since being identified as a potential Superfund site.
TJ
The FS went for. a 21 day public comment period on August 27.
1987. An opportunity for a public meeting was provided for
interested parties. Following the completion of the comment
period on September 16, 1987. no comments were received on the
FS. In addition, no interest in a public meeting was conveyed by
any party.. .
v.
Alternatives Evaluation
The feasibility study (FS) for the NEC site developed and evaluated
an array of remedial alternatives for each discrete waste wnit
on-site. A series of screening criteria were employed to narrow
the field of possible alternatives. The resulting final array of
alternatives was analyzed in detail to select remedies that
attain an acceptable level of effectiveness and implementability,
and were the least costly.
-------
-6-
. - ..
. .
Throughout the remedial alternatives screening procest special.
consideration was provided to those alternatives that employed
the use of treatment technologies which permanently and 5ign-
1ficant1y reduce the toxicity, mobility, and volume of the waste.
A set of remedial action objectives was established in the FS
that would have to be met in the implementation of site remedies.
The objectives were based on the results of the EA and information
provided in the remedial investigation (RI). The EA concluded,
as stated previously, that the site currently under ~resent usage
presents little or no environmental and public health threats.
Consequently, the remedial action objectives emphasized the
minimization of long-term contact with contaminated soil and
sludge, and the prevention of ingestion of conta~inated ground
water. The following objectives were identified in the FS for
site re~edial actions:
o
minimize possible contact with exposed contaminated
sludge;
o
minimize the possible contact with contaminated soil in
the drainage dftch;
.
o
minimize the possible contact with buried soils contaminated
from past disposal. practices; and,
minimize the possible exposure to contaminated ground
water, and adequately prevent ~igration.
o
. .
Based on site information provided in the RI report and the above
stated remedial action objectives, an array of potential general
response actions and corresponding technologies were developed
(Table 1) to address the specific conditions at the NEC site.
Table 1
GENERAL RESPONSE ACTIONS AND
APPLICABLE REMEDIAL TECHNOLOGIES
v
Response Action
Technologies
No action.
Site Monitoring and land
development restrictions
Con t a i n me n t
Capping, revegetation,
ground water containment,
barrier walls
-------
-7-
Extraction
.
i
Ground water pumping
Excavation of sludge and:
soil ..
Solids Removal
On-site treatment
Solidification/chemical,
physical fixation
In-situ treatment
Biorec1a~ation, soi 1
flushing
Landfill
On-site disposal.
Off-site disposal
Permitted facility
Preliminary technology screening criteria were e~ployed in the FS
to e1i~inate those technologies not applicable to the NEC site.
The criteria were as follows:
'J
1 .
There must be a demonst~ated history of successful use.
of the technology in environments similar to the NEC.
site. All technologies of a research and development
nature, and which cannot be reasonably said to be in
common use, are rejected.
2.
Technologies that are not relevant to site specific
problems or cannot be applied because of physical
constrai nts or that wi 11 tend to have uncertai n .
outcomes because of physical constraints are rejected.
Technologies that, when applied, may cause other environ-
mental or health related impacts are rejected..
3.
4.
Technologies which have or imply an overly long period
between implementation and remedial effect or whic~ have
long permitting delays before implementation are rejected
unless there is no other alternative that can achieve
the remedial objective in a more time effective ~anner.
Technologies which are or must be imp1e~ented in concert
with (or are linked to) another technology which is
rejected are also rejected.
5.
General response actions that were screened based on the
criteria were no longer considered for implementation at
site. Table 2 presents those technologies excluded from
consideration.
ab.ove
the NEC
further
-------
-8-
Table 2
.
f
.
Eliminated Technologies
1.
2.
Vertical barriers for leachate and groundwater control.
Horizontal barriers for leachate and ground water control.
3.
Rioreclamation for treatment of waste in place.
Cemeot-hased solidification of sludges and soils.
4.
Table 3 identifies the remaining technologies that were evaluated
in application for remeoial responses at the four discrete waste
units. For a summary description of the general technologies
considered applicable at the NEC site, refer to the FS.
TABLE 3
APPLICABLE TECHNOLOGIES
.
1.
Leachate and Ground Water Controls
a.
b.
c.
Capping.
Revegetation
Ground water pumping
2.
3.
Excavation and Removal of Sludge and Soi1
Ground Water Treatment
a.
b.
c.
Chemical precipitation
Carbon adsorbtion
Air stripping
4.
Sl uc1ge and Soi 1 Treatment
a.
b.
c.
Solids dewatering.
Silicate~based solidification
Thermoplastic solidification
\J
5.
Landfi1ling
a.
b.
On-site disposal
Off-site disposal
The FS singularly addressed each area of contamination on-site and
developed a final array of remedial alternatives. The alternatives
were developed and evaluated based on guidance and requirements
-------
-9-
in the National Contingency Plan (NCP) 40CFR ~ 300.68 ~November 20.
1985) and the "Guidance on Feasibility Studies Under CE~CLA" (June
1985). ,Table 4 presents the list of categories (as stated. in the
NCP) that to the extent that was both possible and appropriate. at
liast one remedial alternative was developed per category in the
FS.
/
TABLE 4
REMEDIAL ALTERNATIVES CATEGORIES
1.
Alternatives for treatment or disposal at an off-site
facility. as appropriate.
2.
Alternatives that attain applicable or relevant and
appropriate federal public health and environmental
requirements.
3.,
As appropriate. alternatives that exceed applicable and
or relevant and appropriate federal pUblic health and
environmental requirements.
.
4.
As appropriate. alternatives that do not attain' applicable
'or relevant and appropriate federal public health and
environme~tal re4uirements. but ~ill reduce the likelihood
of present of future threat from hazardous substances
and provide siynificant protection. to pUblic health and
welfare and the environment.
!).
No action alternative.
In the initial screeniny of alternatives. the list of possible
remedies was further reduced based on a prelimi'nary comparison of
the alternatives. In this phase of the FS. alternatives were
identified based on c~iteria established in the remedial action
categories (Table 4). A cursory analysis of eflvironmental and
public health impacts was undertaken to discern adverse or ben-
ificial effect of the alternative relative to identified environ-
mental and public health concerns. Preliminary cost estimates
were prepared for each remedial alt~rnative. All costs were
developed in present dollar worth amortized at 10 percent over
a 30 year period at +50% -30% range of confidence.
Alternatives were eliminated in this phase of the FS process by
comparing cost of those alternatives that achieve similar environ-
mental and pUblic health results. Within each of the remedial
. action categories (Table 4). those remedial alternatives that
achieve similar outcomes at a higher cost were eliminated from
further consideration.
"
/
-------
.;.10-.
VI.
Detailed Evaluation of Alt~rn~tives
o.
;
.
The technologies that remained following the initial screenin~
were analyzed in greater detail under a set of criteria that
allowed for an across the board comparison of all the alternatives.
A detailed evaluation was performed on each alternative which'
was based on non-cost and cost criteria. The non-cost criteria
developed under the FS included technical feasibility, environmental
and public health impact, and institutional requirem~nts. The
cost criteria analyzed the present worth of capital and operating
expenses and a cost sensitivity analysis for a 10 to 30 year
implementation period at various interest rates.
The technical feasibility criteria spe~ifically addresses 1)
reliability, 2) implementability, 3) safety, and 4) long-term
performance of each alternative. The environmental and public
.health criteria analyzed the extent to which each alternative
met those criteria, in addition to discussing other specific
beneficial and adverse effects of the alternative. The evaluation
of institutional requirements involved addressing applicable o~.
relevant and appropriate federal and state requirements.
In the alternatives cost comparison, capital costs included all
direct costs f~r remedy installation, in addition to indirect
costs, such as fees for engineering, supervision of implementation,
and general overhead expenditures. Yearly operating and maintenance
costs were those defined necessary to ensure proper performance
of the remedy over a"specified period of time, such as costs for
lahar, materials, sampling analyses and admihistrative requirements.
Based on the above stated criteria a "detailed evaluation" of each
alternative was conducted in the FS. Alternati~es were developed
and eva~uated for each of the four areas of contamination on-site,
those identified as:
o
o
o
o
Sludge Lagoon
Drainage Ditch
Seepage Pit
Sludge Dump Area
(]
The remedial action objectives identified in the "development of
alternatives" section above were based on the stated conclusi~ns
in the EA. The "detailed analysis of alternatives" uses the
remedial objp.ctives as goals to be achieved through implementation
of remedial actions.
1 .
Sludge Lagoon Alternative Array
A total of nine alternatives were initially developed in the FS
for the sludge lagoon. Following the "initial screening" process
six alternatives were preserved for the detailed evaluation.
-------
-11-
.
The sludge lagoon operated from 1968 to 1976 as a settling lagoon
for the facility wastewater treatment system. At the time the
Jagoon was removed from service, as much as four feet of'meta1
hydroxide sludges lined the bottom of the lagoon. Analyses of
the sludge indicate that it mainly consists of phosphorus,
a 1 u m i n u m, c h rom i u m, c op per, n i c k e 1, i r 0 n and flu 0 rid e. G r 0 un d
water monitoring data have determined that the metals have leached
into ground water. Direct contact exposure to sludges and soils
in the lagoon presents a potential hu~an health risk as does
ingestion of contaminated ground water resulting from leachate
generation.
The objective as stated in the fS is to minimize contact with
the contaminated sludges and soil and minimize contact with and
prevent use of ground water. Table 5 presents the array of
remedial alternatives evaluated.
TABLE 5
SLUDGE LAGOON REMEOIAL ALTERNATIVES
.
Alternative 1: No action.
Alternative 2:
Cap the 1~90~n and monitor ground water.
Alternative 3:
Solidify sludge. cap .the lagoon and
monitor ground water.
Alternative 4:
Excavate and dispose of sludge off-site;
pump ana treat ground water.
Excav~te sludge and soil. beneath
s 1 u d g e., 'a n d d i s po s e 0 f 0 f f - sit e;
pump and treat ground water.
Alternative 5:
~
Excavate and dispose of sludge.
off-site and monitor ground water.
A detailed analysis of each a1te~rative was conducted to evaluate
1) technical feasibility, 2) environmental and public health impact,
3) institutional issues, and 4) c~st.
Alternative 6:
a.
Alternative 1:
No action.
.
Under the "no action" alternative, only land development restrictions
would be implemented, and no other remedial work would be conducted.
The existing site conditions would continue, such that the potential
for exposure to contaminated sludge would remain, and contaminated
-------
-12-
ground water would continue to be discharged, uncontrDlled, into
the laCrosse River. This alternative would not be co~sistent
with the requirements of the Resource Conservation and R~covery
Act (RCRA) which necessitates that hazardous waste be removed at
closure (clean closure) for a surface impoundment or properly'
capped and monitored for "in place" closure. Specifically, RCRA
closure and post-closure requirements 40 CFR Part 264 Subpart G
or the Wisconsin Department of Natural Resources (WDNR) (NR
181.42(8)) would not be satisfied by this alternative.
In addition, the RCRA 40 CFR Part 264 Subpart F (9264.92) ground
water protection standard is no~ satisfied in that established
cleanup levels (i.e. background, MCls, or ACls) are not met.
Consequently, this alternative is not considered appropriate for
the sludge lagoon.
Cost estimates are not applicable to the "no action" alternative.
b.
Alternative 2:
Cap the lagoon and monitor ground water.
.
This alternative pr6poses the capping of the sludge lagoon to
prevent contact with exposed contaminated sludge, and a ground
water monitoring program to track ground water quality. The
existing monitoring we11s'on~site would be utilized to monitor
pluMe movement. ~round water samples would be taken and ~nalyzed
ona semi-annual basis.
Cap rlesign and implementation are well established technologies
that can be implemented with relative ease. In effort to prevent
degrading of the cap, a long term maintenance program would be
required to inspect for damage from erosion, invasive vegetation
ponding, and settlement., The design and construction of the cap
would meet the criteria of a cover system as described in and
required by 40 CFR ~264.310. .
In consideration of environmental and public health impacts, this
alternative would eliminate the possibility of human exposure to
contaminated sludges and soils in the sludge lagoon. . However,
due to the sludge being located beneath the water table, capping
may reduce leachate gener~tion, but not eliminate it.
a
In this alternative, ground water contamination would continue t~
exceed ground water quality standards. Consequently, the use of
alternate concentration limits (ACls) is proposed as an a~propriate
and relevant requirement (ARAR). The criteria established in the
Superfund Amendments and Reauthorization Act of 1986 (SARA) for
the use of ACls at Superfund sites (Section 121 (d)(2)(B)(ii))
are met at the NEC site, such that 1) there are known points of
-------
-13-
. . ~
entry of ground water into t~e LaCrosse River, 2) th~ EA demon-
strates that there is no statistical increase of indicatQr
.compounds downstream from the discharge points in the river, and
3) institutional controls (ie. deed restrictions) will prevent
human exposure to contaminated ground water between the sludge
lagoon and the points of ground water discharge to the LaCrosse
River (NEC owns the property up to the river).
The ACLs established for site contaminants will essentially be
ground performance standards that will regulate ground water dis-
charge and surface water quality. A discussion on how ACLs will
be applied to the NEC site is found in Section VII(2). of this
document. .
This alternative satisfies RCRA closure and post-closure require-
ments (40 CFR Part 264 Subpart G) and state closure standards
(NR 181.42(8)). The use of ACLs satisfies the RCRA ground water
protection regulations in 40 CFR Part 264 Subpart F, specifically
~264.94.
.
Cost estimates were based on initial capital costs, and annual
operation and maintenance cost amoritized at 10 percent over a 30
year period.
Cost Estimate for Alternative 2
L
Capital
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
$127,000
10,200
96,000
2.
Annual Operating ..................
-Present Worth ..................
(30 yrs., 10% interest)
3.
Total Project Cost
. . . . . . . . . . . . . . . .
$223,000
c.
Alternative 3:
Solidify sludge, cap the lagoon;
monitor ground water.
T his a 1 t ern a t i y e proposes to so 11-d i f y the s 1 u d g e i n the s 1 u d g e
lagoon in an effort to reduce contaminant mObility, in conjunction
with providing a RCRA approved cap over the lagoon to further
impede leachate generation. In addition, a ground water monitoring
program would be implemented to track the plume and ensure perfor-
mance of the remedy.
Sludge solidification is an established technology that has been
implemented successfully on various types of waste composition.
It has shown to be quite effective with metal hydroxide sludges,
as those in the sludge lagoon. The solidification process would
be accomplished in-situ employing the lagoon itself as a mixing
pit. . An appropriate solidifying agent would .be injected into the
sludge layer, then the sludge would be physically mixed through
the use of a backhoe.
-------
-14-
. .
. .
Once the sludges have set, a cap would be emplaced oWer the entire
lagoon. A firm bas~.for cap emplacement would be prdvided by the
solidified sludges, enhancing the long-term integrity of. the cap.
"A multilayered cap system would" be designed for the lagoon. The
cap would consist of an upper vegetative layer, underlain by a
drainage layer that lies atop a. synthetic liner. Beneath the
synthetic liner, a layer of low-permeability material such a
clay, would b~ emplaced. The cap would meet the criteria in
40 CFR ~264.310 for cap design and construction. .
A ground water monitoring program would be initiated to track
the existing plume and to ensure that the remedy is performing
adequately. Present ground water contaminati~n at the site
exceeds background levels and MCLs. Consequently, given the
conditions at the site, "ACLs would be applied to protect the
river water quality, and used a~ ground water performance standards.
Contaminants found in ground water are at trace levels in the
LaCrosse River, in inconclusive differences exist between upstream
and downstrea~ concentrations. As stated in Alternative 2,' the
criteria established in SARA for the usde of ACLs is met at the
NEC site. Refer to Section VII(2) of this document for the.
discussion of ACL application to the NEC site.
This alternative would provide more than adequate public health
- and environmental protection through elimination of dir~ct human.
contact of sludges, reduction of leachate generation, semi~annual
ground water monitoring, and the application of ACLs for plume
management. Conseq~ently, this alternative satisfies RCRA closure
and' p 0 s t - c 1 0 sur e r eq u ire me n t sin 4 0 C F R Par t . 2 6 4 Sub par t G and s tat e
"closure standards (NR 181.42(8)). The use of ACLs satisfies the
RCRA ground water protection regulations in 40 CFR Part 264
Subpart F, specifically ~264.94. .
Cost estimations for this alternative were based on initial capital
expenses and annual operation and maintenance costs amortized at
10 percent over a 30 year period.
Cost Estimate for Alternative 3
o '.
1.
Capital
. . . . . . . . . . . . . . . . . . .
$169,UOO
2.
Annual Operating ..........
-Present Worth ..........
(30 yrs., 10% interest)
Total Project Cost
10,200
96,000
3.
. . . . . . . .
$265,000
Excavate and dispose of sludge off-site;
pump and treat ground water.
This alternative entails the complete excavation of sl~dge from
the lagoon, and suhsequent transport and disposal at a RCRA
d.
Alternative 4:
-------
-15-
per m i t t e d la n d fill. I n ad d i t i on, a ground wa t e r p u mp!i n g an d
treatment system would be iMplemented. An estimated 150q cubic
.yards of sludge would be removed from the lagoon and disposed.
Contaminated ground water at the site would be extracted and
treated in a precipitation/flocculation unit for the removal
of metals, and then discharged into the LaCrosse River.
Sludge excavation is proven technology that could be undertaken
with relative ease at the sludge lagoon. A three-quarter cubic
yard drag line would be used to undertake the excavation due to
the excessive moisture of the sludge. Approximately two weeks
would be necessary to complete the sludge removal.
On-site ground water extraction and treatment systems have shown
repeated success in application at contamination sites. However,
the FS has identified a ~otential problem in implementation of
the ground water extraction system near the sludge lagoon.
Capture wells would be located hydraulically downgradient from
the lagoon"which would place the wells within 150 f~et of the
LaCrosse River. The stated concern is that a'pumping scheme
could possib1ly draw a significant amount of river.water into
the system, which would significantly lengthen the period of
performante of the extraction and treatment system. An estimated
15 to 30 years would be required to reduce the metals concentration
to background. As a result, the total project cost would be quite
onerous in comparison to other alternatives that achieve similar
environmental and pUQlic health benefits.
In analyzing the degree of environmental and public health pro-
tection of this alternative, consideration must be given to the
conclusions of the EA. In regard to ground water contamination,
,although the cumulative cancer risk through ingestion of ~round
wate~ exceeds the 1 x 10-6 value, the possibility of this actually
occurring appears quite remote. No industrial, private, or public
water supply's are located downgradient from the lagoon to the,
LaCrosse River. Land development restrictions would preclude the
future use of the property for water well construction. Presently,
the only scenario that would result in exceeding the 1 x 1U-6 '
cancer risk would be through the',unlikely possibility of 'an
individual ingesting two liters of water per day from the
most contaminated monitoring well for a lifetime.
.
The EA states that inconclusive differences exists between up-
stream and downstream concentrations of contaminants, indicating
little or no apparent present impact to surface water quality
from the NEC site. Consequently, little environmental or public
health benefit would be derived from a ground water pumping and
treatment system. The cost of such a system would be onerous in
comparison to alternatives that achieve similar benefits.
-------
. .
-16-
Regarding the excavation of sludge from the sludge la~oon, the EA
concludes that di rect contact to the contaminated sludge and soil
~oes indeed present a public health threat, and should be prevented
through implementation of a remedial action. Direct contact with
the sludge and soil, however, can be precluded through other
effective means (i.e. capping/ solidification) without the
burdensome costs of off-site transportation and disposal of the
sludge material. In addition, the off-site transport and disposal
of waste is the least preferred of possible remedies, as stated
by SARA, where practicable treatment technologies exist. As
. indicated, Alternative 3 of this alternatives array provides
on-site treatmen.t (sludge solidification) which achieves similar
environmental and public health benefits without the use of
off-site disposal. .
Consequently, although this alternative satisfies RCRA closure
and post-closure requirements in 40 CFR' Part 264 Subpart G and
state closure standards (NR 181.42(8)), it is not considered
cost effective for the sludge lagoon when compared to other alterna-
tives that achieve the same objective~. .
'Cost estimates are based on initial capital expenses and annual
operation and maintenance cost amortized at 10 percent over a 30
year period.
Cost Estimate of Alternative 4
1.
Capital.'
. . . . . . . . . . . . . . . . . . . . . .
$
779,000
2.
Annual Operating ............~
-Present Worth .............
(30 yrs., 10% interest)
Total Project Cost ...........
66,OOU
622,000
$1,401,000
'3.
e.
Alternative 5:
Excavate sludge and soil beneath sludge
and dispose of off~site; pump and treat
ground water.
. '
This alternative is different from Alternative 4 only in respect
to the removal of contaminated soil beneath the sludge in addition
to the sludge. All excavated material would be sent off-site to
a RCRA permitted landfill, and a ground water pumping and treatment
system would be implemented. .
The discussion of this alternative basically mirrors that of
Alternative 4. The same advantages and disadvantages exist for
both alternatives. The only added benefit of this alternative
would be the additional removal of cont~minated soil beneath the
sludge, which would provide a greater degree of confidence in
source control. .
-------
-17-
This alternative. as in Alternative 4. satisfies RCRA closure
and post-closure requirements 40 CFR Part 264 Subpar~ G and ~tate
closure standards (NR 181.42(8)). however. as a resul~ of the
same issues and concerns stated in Alternative 4. this alter-
'native is not considered applicable for the sludge lagoon.
Cost estimations are based on initial capital expenses and ann~al
operation and maintenance cost amortized at 10 percent over a 30
year period.
Cost Estimate of Alternative 5
1.
Capital
. . . . . . . . . . . . . . . . . . . . . . . .
$
984.000
66.000
622.000
2.
. "
Annual Operating ...............
-Present Worth ...............
(30 yrs.. 10% interest)
Total Project Cost
. . . . . . . . . . . . .
$1.606.00U
3.
Excavate and dispose of sludge off-sit~
monitor ground water. .
f.
.Alternative 6:
This .1ternative proposes the removal of all sludges from the
lagoon. and to transport and dispose of .at a RCRA permitted'
landfill. In addition. a ground water monitoring"program would
be instituted using the existing site monitoring wells.
S 1 u d 9 e e x c a vat ion w:o ul d be u f1 d e r t a ken t h r 0 u 9 h use 0 f d rag - 1 i n e
type equipment. Conventional earth-moving equipment would not be
employed due to the difficulties in handling very moist sludge.
The use of drag-line equipment is a well established technology
with a proven history in conditions slJch as those that exist
in the sludge lagoon. .
The excavation of sludge through this remedy would effectively
eliminate the source of contamination; however. the present
ground water contamination would continue. to exceed ground water
quality standards. As a result. ACls are proposed to be applied
as site specific ground performance water ~tandards. Refer to
Section VII(2) of this document for the discussion of ACl applica-
tion to the NEC site. .
A ground water monitoring program to be developed in the remedial
design phase would be implemented to track and monitor th~
existing plume and ensure performance of the remedy.
/
This alternative. would satisfy
requirements in 40 CFR ~264.92.
requi rements in 40 CF R Part 264
standards (NR 181.42(8)).
RCRA ground water protection"
RCRA closure and post-closure
Subpart G and state closure
-------
-18-
Although this alternative would satisfy federal and siate closure
standards, it has heen rejected as a possible remedi~l alternative.
As indicated in other alternatives that propose off-site disposal,
,SARA mandates that "off-site transport and disposal with6ut
treatment is the least preferred option where practicable treatment
technologies are available." And furthermore, SARA establishes a
pre fer e n c e for rem e d i a 1 act ion s t hat uti 1 i z e t rea t me nt' top e r -
manently and significantly reduce the volume, toxicity, or mObility
of hazardous substances. In light of these stated preferences,
this alternative does not satisfy either of the two. By comparison,
Alternative 3 of this array does meet the preference for treatment
through use of sludge solidification, which will significantly
reduce the mobility of the metal hydroxide sludges.
Alternative 6 provides no greater environmental or public health
benefit than does Alternative 3. Both alternatives meet the
stated remedial action objectives. This alternative meets the
objectives through elimination of the leachate source and the
potential of direct human contact. Alternative 3 achieves the
objectives through plume management and the capping and solid-
ification of the lagoon. Aternative 3 does, however, provide a"
considerable cost savings over Alternative 6.
Cost estimates for this alternative are based on initial capital
expenses and annual operation and maintenance costs amortized. at
10 percent over a 30 ye~r period.
Cost Estimate of Alternative 6
1.
Capital.
. . . . . . . . . . . . . . . . . . . . . . . .
$377,000
2.
Annual Operating ...............
-Present Worth ................
(30 yrs., 10% interest)
Total Project Cost
8,000
76,000
3.
. . . . . . . . . . . . .
$453,.00U
2.
Drainage Ditch Alternatives Array
A total of five remedial alternat'ives were developed in the FS
for the drainage ditch. Following the "initial screening of
alternatives", four alternatives remained for the detailed
analysis.
. .
The drainage ditch was employed to convey treated effluent from
the sludge lagoon, during the operating years, to a storm runoff
ditch where it combined with the City of Sparta's wastewater
effluent prior to discharge into the LaCrosse River. 'Fie1d
investigations have revealed elevated levels of fluoride, copper,
zinc and nickel in the surface soil of the ditch.
-------
/
-19-
The objective of the remedial action, as stated in t~e FS, is to
minimize the potential for contact with contaminated soil in the
.drainage ditch. Table 6 presents a summary of remedial alternatives
for the drainage ditch.
TABLE 6
Drainage Ditch Remedial Alternatives
Alternative 1:
No action
Alternative 2:
Access restriction through
installations of a fence.
Alternative 3:
Excavate contaminated drainage
ditch soil and place in sludge
lagoon.
Alternative 4:
Excavate contaminated drainage
ditch soil and dispose off-site~
The FS conducted a detailed analysis and evaluation of each
alternative based on the following parameters: 1) technical
feasibility, 2) environmental and pUblic health impact~ .
3) institutional issues, and 4) cost. .
a .
Alternativ~.1:
No action.
The "no action" alternative would be liMited to only land developMent
'restrictions, no remedial work would be conducted at the drainage
ditch.
The EA states that exposure to contaminated soil in the drainage
ditch poses a human health risk. This alternative does nothing to
provide source control to alleviate public health risks. RCRA
requirements necessitate that hazardous waste and residuals be
r~moved at closure or capped and monitored "in place". Consequently,
this alternative does not satisfy RCRA closure and post-closure
requirements in 40 CFR Part 264 ~ubpart G or state closure standards
(NR 181.42(8))..
Cost analyses are not applicable for the "no action" alternative.
b.
Alternative 2:
Access restriction.
This alternative entails the construction of an eight foot high
barbed wire chain-link fence around the drainage ditch area. A
locked entrance.gate would restrict access to the site to only
authorized. pers6nnel. The FS indicates that approximately 150
f~et of fencing around the area would be required.
-------
. .
-20-
The fence would remain as a permanent feature a~ound the drainage
ditch and would require periodic maintenance. . . i .
.
The contaminated soil would remain in the ditch, however'~
'fence would reduce the likelihood of casual human contact
the soil. The threat of contact would still persist with
alternative due to the continued presence of contaminated
soil. .
the
with
this
surface
Consequent to the continued threats to ground water and the
potential direct human contact risk, this alternative would not
meet the RCRA closure and post-closure requirements 40 Part CFR 264
Suhpart G or state closure standards (NR 181.42(B)).
The cost estimate for Alternative 2 is based solely on. initial
capital costs for implementation. No substantial maintenance or
10ng-t~rm costs are associated with this alternative.
'Cost Estimate for Alternative 2
Total Project Cost
(fence construction)
. . . . . . . . .
$3,000
.
A1t~rnative 3: Excavate contaminated drainage ditch
soil and place in sludge lagoon.
This alternative proposes to remove all contaminated soil in the
drainage ditch area. and placement in the "sludge lagoon" for
c10su~e. This alternative assumes that the "sludge 1agoo~"will
be capped as described in Alternative 2 or Alternative 3 of the
"sludge lagoon alternatives array".
c.
Soil excavation is a well established technology with a proven
history of success. A backhoe would be employed to conduct the
s 0 11 excavation a n dc 1 e a n s 0 11 material will be use d for backfill
to restore the excavation area t~ its previous contour.
Removal 01 the contaminated soil would eliminate any possibility
of human contact and decrease the areal extent of surface contami-
nation thus achieving the desired affect of the remedial action
objective. This alternative. would only be implemented if capping
. of the sludge lagoon were approved (i.e. sludge lagoon Alternative
2 or 3). The addition of this material to the lagoon would not
exacerbate the conditions in the sludge lagoon.
Contaminated soil removal from the drainage ditch would satisfy RCRA
closure and post-closure requirements 40 CFR Part 264 Subpart G
and state closure standards (NR 181.42 (8)).
-------
-21-
.
The c 0 s t est i mat ion for t his a 1 t ern a t i ve i s bas e d sol' e 1 yon i nit i a 1
capital costs for implementation, no maintenance or long~term
'costs are associated with this alternative.
Cost Estimate for Alternative 3
Total Project Cost
. . . . . . . . . .
$2,50U
d.
Alternative 4:
Excavate contaminated drainage ditch
soil and dispose of off-site.
This alternative entails the excavation oi c~ntaminated soil, and
subsequent disposal at an off-site RCRA permitted landfill. This
remedy is identical to Alternative 3 with the exception that
soils are disposed of off-site ~s opposed to in the sludge lagoon.
As with Alternative 3, this alternative would eliminate the threat
of any exposures with contaminated soil in the drainage ditch.
As a result, this alternative satisfies the requirements of RCRI
closure and post-closure requirements in 40 CFR Part 264 Subpart G
and state closure standards (NR 181.42 (8)).
,In consideration ,to the preference o~ SA~A,' which states'that
off-site disposal of waste is the least' preferred alternative
where practicable treatment technologies exist, this alternative
is rejected in favo~ of Alternative 3 which, employs the use of
slunge solidification to significantly reduce the mobility of the
waste in the lagoon aiding in the long~term performance of the
remedy.
Cost estimates for this alternative are based solely on initial
capital costs, no long-term maintenance or operation costs are
applicable.
Cost Estimate of Alternative 4
Total Project Cost
. . . . . . . . . . .
$11,OOU
3.
Sludge Dump Site Alternatives Array
i
A total of seven remedial alternatives were developed in t.he FS
for the sludge dump site. Following the "initial screening of
alternatives" four remained for the detailed analysis.
The sludge dump contains material that was excavated from the
sludge lagoon during its period of operation~ Currently, no
-------
-22-
ground water contamination has been attributed to the sludge
dump site. Approximately 930 cubic yards of combined s]udge and
soil were buried in the dump, and, presently, two feet pf soil
covers the sludge dump site.
T~e remedial action objective is to reduce or minimize the threat
of contact exposure with the sludge. Table 7 presents the list
of alternatives for remedial action.
TABLE 7
SLUDGE DUMP SITE REMEDIAL ALTERNATIVES
Alternative 1:
No.action
Alternative 2:
Cap dump site
Alternative 3:
Excavate sludye for off-site
disposal
Excavate sludge and soil for
off-site disposal
.
Alternative 4:
The FS conducted a detailed analysis and evaluation of each
alternative based on the following perameters: 1) technical
feasibility, 2) environmental and public health impacts,
3) institut.iona1 issues, and 4) co~t.
a.
Alternative 1:
No action.
The "no action" alternative involves only the implementation of
land development restrictions, no remedial work would be conducted.
Due to the existence of two feet of soil cover over the sludge
dump, the 'chance of casual human cont'ct exposure is remote.
Construction, as the result of property development, would be the
most likely scenario in. which an exposure event could occur.
Development restrictions attached to the property deed would
preclude this from occuring. '
The potential for ground water con~amination remains a threat
with this alternative due to the c~ntinued existence of the
wast~. although presently, no ground water contamination has yet
been attributed to the sludge dump.
RCRA closure requirements would not be met with this alternative.
.
Specifically, 40 CFR Part 264 Subpart G which requires that
post-closure yround water monitoring be undertaken at the site
-------
-23-
following closure of the unit. Similarly. Wisconsin iDepartment
of Natural Resources requirements for long term care; including
monitoring. of landfills and surface impoun~ments (NR 181.42(9))
.wou1d not be satisfied. Consequently. this a1ternative"-is not
considered applicable for the sludge dump.
Cost estimations are not applicable to this a1ternati~e.
h.
Alternative 2:
Capping of the sludge dump.
This alternative proposes the capping of the sludge dump site. "
which would further reduce the likelihood of casual human contact
with contaminated soil and sludge (in comparison to the "no
action" alternative). and would also minimize future leachate
generation into ground water."
r.apping is well proven technology and could be easily implemented
at the site. A cap could be designed and implemented with relative
case at the sludge dump site. Design details of the cap would
provide for proper lining material. erosion control. drainage.
ann long-term maintenance. land development restrictions would.
preclude activities that could potentially damage the cap.
As in Alternative 1. this alternative does not provide for post-
clos~re ground water-moni~oring as required by 40 CFR Part 264
Subpart h. Post-closure monitoring is a relevant and appropriate
require~ent as a result of "in place" closure of the sludge dump.
Similarly. state pO$t-~losure monitoring requirements (NR 181.42(Y))
woul d :
not be sati~fied. Consequently. this alternative is not considered
applicable for the sludge dump.
Cost estimates include ini:tial capital costs. and annual operation
and maintenance cost amortized at 10 percent over a 3U year
operating period.
Cost Estimate of Alternative 2
- 1. Capital . . . . . . . . . . . . . . . . . . . . . . .. $23.UUO
2. Annual Operating . . . . . . . . . . . . . . 5UO
-Present Worth . . . . . . . . . . . . .. 5.UUU
(30 yrs.. 10% interest)
". $28.000
3. Tot a 1 Project Cost . . . . . . . . . . . . .
c.
Alternative 3:
Excavation of sludge and dispose off-site.
This alternative proposes co~plete removal of sludge from the
dump site. An estimated 90U cubic yards of sludge would be
-------
-24-
.. . . . : .
excavated from the dump and transported and disposed ~of at a
RCRA permitted landfill. The duf'1p 'site would be backfilled
,with native soil following excavation to its former grad~.
The excavation and backfilling would be undertaken with con-
ventional earth moving equipment (i.e. front-end loader and.
backhoe). It would take approximately one month to complete the
project.
The removal of the sludge (not including residual contaminated
soil) from the sludge dump area would all but eliminate the
probability of human contact with contaminated material, and
significantly reduce the likelihood of leachate generation fnto '
ground water. .
This alternative would satisfy RCRA closure and post-closure
requireMents in 40 CFR Part 264 Subpart G and state closure
standard (NR 181.42(8)) through minimizatio~ of human health
risks.
.
As indicated in Alternative 4 of the '"drainage ditch alternatives
array", off-site disposal of waste is the least preferred alternative
where practicable treatment technologies exist. In this case,
o the r a 1 t ern a- t i ve sex i s t t hat pro v ide e sse n t i ally the sam e e n vir 0 n'
mental and public health benefits, such as Alternatives 1 and 2,
at a significantly lower cost without employing off-site disposal.
Consequently, this alternative is not considered applicable to
the sludge d IJ m psi te-.
'Cost estimates are based solely on capital cost (i.e. excavation,
transportation and disposa1),annua1 operation and maintenance
cost are not applicable.
Cost Estimate of Alternative 3
Total Project Cost
. . . . . . . . . . . . . . . .
$179,000
d.
Alternative 4:
Excavation of sludge and soil
and disposal off-site.
This alternative is the same as Alternative 3 except for the
addition of removal of contaminated soil beneath the sludge. An
estimated 1,400 cuhic yards of combined sludge and soil wQu1d be
excavated and removed off-site.
As in Alternative
with conventional
anrt soil would be
landfill.
3, excavation and backfilling would be undertaken
earth moving equipment. The excavated sludge
transported and disposed of in a RCRA permitted
-------
-25-
This alternative provides a greater degree of assurance in
complete contaminant removal from the sludge dump si~e than
does Alternative 3. It reduces or eliminates altogether the
threat of ground water contamination from leachate generation.
, '.
This alternative would satisfy RCRA closure and post-closure
requirements 40 CFR Part 2b4 Subpart G and state closure standards
(NR 181.42 (8)) through complete removal of contaminated material
from the sludge dump.
As stated in previous alternatives tha't propose off-site disposal.
off-site disposal is considered the least preferred alternative
where other. alternatives exists that employ treatment technologies
that pe~manently and significantly reduce volume toxicity or
mohility of hazardous substances. In this situation there are
other alternatives (Alternatives 1 and 2) that achieve the same
level of protectivenss without the use of ,off-site disposal' and.
in addition. at a significantly lower cost. Consequently. this
alternative is not considered applicable at the sludge dump site.
Cost estimations are based solely on capital costs (i.e. excava,ion.
transportation. and disposal). Annual operation and maintenance
costs are not applicable. . .
Cost Estimate.of Alternative 4
Total Project Cost
. . . . . . . . . . . . . . . . . . . . .
$274.00U
.4.
Seepage Pit Alternatives Array
A total of five remedial alternatives were deve10ped.for the seepage
pit. Following the "initial screening of alternatives". four
remained to be evaluated in the detailed analysis.
The seepage pit was removed from operation in 1976. and eventually
backfilled with 15 feet of clean fill in 1981. A number of
chlorinated volatile organics and heavy metals have been detected
in monitoring wells downgradien~ from the the seepage pit. The
seepage pit continues as a suspetted source of ground water
contamination. Soil samples have revealed elevated levels of.
fluoride. aluminum. chronium and copper. No sludge was encountered
during the field investigations of the seepage pit. The primary
route of exposure would be through ground water ingestion. Contact
with contaminated soil is considered an unlikely exposure"scenario.
The remedial action objective is to minimize human contact with
contaminated soil. and to eliminate or reduce the threat of
-------
-26-
.
t
exposure to contaminated ground water. Table 8 presents a
summary of preliminary alternatives for remedial action. 'c
TABLE 8
Seepage Pit Remedial Alternatives
Alternative 1:
No action.
Alternative 2:
Excavation of soil for
off-site disposal.
Alternative 3:
Access restrictions and
ground water monitor.
Alternative 4:
Excavation of soil for off-site
disposal; pump and treat ground
water.
. .
The FS evaluated each alternative based on the follow1ng preameters:
1) technical feasibility, 2) environmental and public health impacts,
3) institutional issues, and 4) cost.
A 1 ternat"i ve 1:
No action.
a.
In the "no action" alternative, only land development restrictions
would be ohtained, no"rememdial works would be conducted. This
alternative would do nothing to cease, reduce, or monitor the
,continued release of contaminants into ground water by the seepage
pit.
RCRA"ground water protection requirements 40 CFR ~264.92, necessi-
tating ground water cleanup to background, MCLs, or ACLs, would
not be satisfied.
RCRA closure and post-closure requirements 4U CFR Part 264 Subpart
G and state closure standards (NR 181.42 (B)) would not be sat'isfied
with this alternative. Consequently, the "no action" alternative
is not considered applicable for the seepage pit. .
Cost estimates are not applicable in this alternative.
Alternative 2:
Excavation of soil for off-site disposal.
b.
This alternative proposes the complete removal of contaminated
soil in the seepage pit (no sludge exists). This would effectively
remove the source of ground water contamination and allow for
future land development at the site.
-------
-27-
Con tam i Ii ate d s 0 i 1 w 0 u 1 d bet ran s po r t e d to and d i s P 0 sed; 0 fat a
RCRA permitted landfill. Clean fill material would be" used for
backfilling following the excavation. The total project .would
take approximately one month to complete.
The technology of soil. excavation is well established and could
be undertaken with relative case at the seepage pit. Conventional
earth moving equipment (i.e. front-end loader and backhoe) would
be ~nployed to undertake and complete the project..
Excavation of contaMinated soil would effectively eliMinate or
significantly reduce the source of ground water contamination.
However, .groundwater at the facility is presently contaminated
with vac's at levels above either background or MCLs. This
alternative does little to return ground water quality to
acc~ptahle levels. As a result the RCRA ground protection
requirements in 40 CFR ~264.92 would not be met by this alternative.
Consequently, this alternative is not considered applicable for
the "seepage ~it".
.
The cost estimate was based solely on capital costs (i.e.
excavation, transportation .and disposal). Annual operation
and maintenance costs are not applicable. .
Cost Estimate for Alternative 2
Total Project Cost
. . . . . . . . . . . . . . . . . . . . .
$77,OUU
c.
Alternative 3:
Site access restriction; monitor ground
water.
This alternative would employ the use of land development
restrictions in the property deed to minimize the potential of
human contact with contaminated soil and ground water. In addition,
a ground water monitoring program would be developed and implemented
to identify any changes in ground water quality. Monitoring would
be conducted on a semiannual basts for an initial 5 year p~riod,
at which time, an assessment would be conducted to determine.
future sampling requirements.
This alternat1ve proposes the development of alternate concentration
limits (ACL) as site specific ground water quality standaras for
vacs. Ground water contamination would continue to exist with
this alternative. However, because no adverse environmental or
public health impact exists, the use of ACLs is appropriate for
plume management. The ACLs would be used as action levels, to
-------
-28-
;
pro~ect the surface water quality adjacent to the sit~ from
degradation. If exceded a corrective action response would
tnitiated. .
further
be
The groundwater situation meets the established criteria for
applicability of,ACLs in both SARA (Se~tion 121(d)(2)(B)(ii) and
RCRA (40 CFR 9264.92). Refer to Section VII(2) of this document
for the discussion of ACL application to the NEC site.
Contamination that emanat~s from the seepage pit travels through
two routes of exposure; ground water and, subsequently, surface
water. This alternative precludes direct ingestion of ground
water through the use of land development restrictions, which
would disallow the construction of water wells at or downgradient
of the seepage pit. Surface water would be protected through the
application of ACLs at the site. LaCrosse River water has revealed
trace amounts of trichloroethylene upstreaM and downstream of the
NEC facility. Trichloroethylene is the only VOC detected in the
in the river at concentrations well below the maxium acceptable
level set for aquatic life. As a result, the quality of surface.
water 'is not presently adversely impacted by the seepage pit. .
Consequent to the employment of land development restrictions,
ground water monitoring, an~ the use of ACLs; RCRA ground water
requirements (40 CFR 9264.92), RCRA closure and post-c10s~re
requirements 40 CFR Part 264 Subpart G and state closure standards
(NR 181.42(~)) would, be satisfied with this alternative.
, ,
Cost estimates are based solely on an amortized 10 percent 30
year operating and maintenance expenditure.
Cost Estimate for
Alternative 3
Total Project Cost
. . . . . . . . . . . . . . . . . . . . .
$!:I5,OOO
d.
Alternative 4:
Excavation of soil for off-site disposal;
pump and treat ground water for volatile
or g ani c s ~, . ..
This alternative proposes the excavation of contamina~ed soil
from the seepage pit and the transport to and disposal of at a
RCRA ~ermitted facility. In addition, a pUMping and treatment of
ground water program would be initiated for the removal of ~olatile
organic comp~unds (Vat's). .
Soil excavation would he undertaken with conventional earth moving
equipment (i.e. backhoe and front-end loader). . The excavated area
-------
(
-29-
would be hackfilled and graded to its previous contou~. Approxi-
mately one month would be necessary to complete the excavation
and backfilling. The excavated soil would be tested for .IP
toxicity, and if necessary, "the soil would be disposed of in a
RCRA permitted landfill.
The ground water pumping and treatment system would involve the
installation of extraction wells installed south of the sludge
lagoon and north of the LaCrosse River. The treatment system
would consist of an air stripping unit to remove VOCs, effluent
would be discharg~d into the LaCrosse River.
As stated in previous alternatives that propose ground water
pumping, the proximity of extraction wells to the LaCrosse River
would induce a significant volume of river water into the pumping
and treatment system. This would reduce the effectiveness of
plume cont"rol, and significantly lengthen the period of performance
of th~ system, which would appreciably inflate the cost of the
remedy.
Although this alternative satisfies RCRA closure and post-closur~
requirement in 40 CFR Part 264 Subpart G. and state closure standards
(NR 181.42 (B)), it is not consid~red suitable for the seepage
pit. The conditions at the site, such as they are, allow for the
~xistence of elevated levels of VOCls without adve~sely impacting
public health or the environment," as stated in the EA. The use
of ACLls at the site has been deemed appropriate for plume
management. In lig~t of this, a ground water treatment .program
would do little to improve an already acceptable condition at the
. sit e . Fur the r mo r e, the con c ern 0 f w he the rat e c h n i c all y e f f e c t i ve
and efficient ground water extraction system can be implemented
has been acknowledged to potentially lengthen the period of
performance of the remedy and inflate the overall cost.
Cost estimates for this alternative are based on initial capital
expenses and annual operation and maintenance costs amortized at
10 percent over a 30 year period. Disposal costs were based on
quoted estimations from Chemical Waste Management, Inc. (Fort
Wayne, Indiana facility - Adam C~nter). .
Cost Estimates for Alternative 4
1.
Cap ita 1 C os t s
. . . . . . . . . . . . . . . . . . . . . . .
$149,20U
2.
Annual Operating .....................
-Present Worth .....................
(30 yrs., 10% interest)
Total Project Cost
54,5UO
514,000
3.
. . . . . . . . . . . . . . . . . .
$646,000
-------
-3U-
V I I. S e I e c t e d Rem e die s
.
;
.
T~e "alternatives arr~y evaluation" analyzed, separately, tbe four
discrete areas of contamination on the NEC sHe, those beiny the
sludye layoon, the drainaye ditCh, the sludge dump site, and the
seepa~e pit. As a result of the previously described "alternatives
evaluation", a remedy was Choosen for each discrete waste unit
on-site. All the sludyes on-site wnl be solidified in the sludye
la~oon for "in place" closure. Both the sludge dump site and the
drainaye ditch wnl be "clean closed" resultiny from total removal
of hazardous waste materials and residuals. A description of eaCh
selected remedy and rationale for selection wnl be discussed in
the ensuiny section.
I.) Source Control
-a.) Sludye Layoon
The contaminated sludye and soil in the sludge layoon will be
solidified, and a RCRA cover installed atop the lagoon to minimize.
leachiny of contaminants into yround water and health riskS.
related to direct contact with the. slud~e and soil.
Approximately, 3UUU cubic yards of contaminated sludye an
-------
. .
-31-
soil. The cover will be designed and constructed to flJeet RCRA
requirements in 40 CFR ~264.310 that specifies that a "final cover
must:
1 .
Provide long ter~ minimization of migration of liquids
through the closed impoundment.
2.
3.
Function with minimum maintenance.
Promote drainage and minimize erosion or abrasion of the
cover.
. 4.. A c com mo d ate set t 1 i n g and sub sid e n c e sot hat the c' 0 v e r I s
integrity is maintained.
5.
Have a permeability less than or equal to the permeability
of any bottom liner system or natural subsoils present.
Post-closure activities will be necessary to ensure the long-term
performance of the remedy. Gro~nd water monitoring, site inspections,
and site maintenance will be performed as relevant post-closure.
requirements. Table 9 presents the cost estimations for the
slurlge lagoon remerly.
b.) Drainage Ditch.
The contaminated soil in the drainage ditch will be excavated and
solidified in the sl~dge lagoon to minimize health risks associated
with direct .contact with the soi1s~
The total amount of affected soil to be excavated will- be deter-
mined through field sampling during the remedial design phase.
The excavated soils will be solidified in conjunction with the
sludge~ and soils presently in the sludge lagoon. The contaminants
identified in the soils of the drainage ditch are essentially
identical to those found in the sludge 1agoo~. The solidification
process and subsequent capping and post-closure of the sludge lagoon
are described in the sludge lagoon selected remedy.
The EA determined that th. surface soils in the drainage ditch
present a potential health risk to both adult and child populations
coming into direct contact. Exposure to contaminated soil can
occur through dermal absorption and ingestion. The selected
remedy eliminates any potential contact with the contaminated
soil in the drainage ditch. .
Post-excavation sampling of the drainage ditch will ensure that
contamination no longer exists. Soils analysis must show con-
taminants to be below compound detection limits for the drainage
ditch to he considered clean. Once this criteria for clean~p
-------
-32-
has been met, RCRA post-closure monitoring and care wil~ not be
considered an applicable or relevant and appropriate re~uirement.
Table 10 presents the cost estimates for the drainage ditch
remedy.
c.) Seepage Pit
Land development restrictions
pit to minimize the potential
soils. Long term ground water
track changes in ground water
protection standards.
Contaminated soils in the seepage pit exist approximately fifteen
feet below yrade. Exposures are considered possible throuyh
inyestion of contaminated yround water and soil, and dermal
absorbtion of contaminated soil.
will be implemented at the seepage
of direct contact with contaminated
monitoring will be conducted to
quality relative to RCRA ground water
Future land- development at the seepage pit will explicitly be
restricted and reflected in the property deed. The deed will
indicate the presence of hazardous materials on the property and.
disallow construction of water wells or buildiny construction
atop the seepage pit.
A newlyc~nstructed cover o~er the seepage pit may ~e necessary
if the present cover does not meet the requirements of landfill
covers found in 40 CFR 9264.310. The present cover must demonstrate
that its permeability js less than or equal to the permeability
of any bottom liner sjstem or natural sub-soils present, and that
the cover promotes drainage with a minimization of erosion or
abrasion. Should the present cover not meet these objectives or
any other criteria set forth in 40 CFR 9264.310, modifications
will be made to the cover as necessary. Analysis of ~he cover's
character will be conducted during the remedial design phase.
Long-term maintenance and periodic inspections of the cover will
be performed as relevant post-closure requirements for the seepage
pit. Quarterly ground water monitoring will be undertaken as a
post-closure activtty.
Table 11 presents the cost estimates for the seepage pit remedy.
d.)
Sludge Dump Site
Contaminated sludge and soil in the sludye dump will be excavated
and solidified in the sludye lagoon. This will effectively minimize
the migration of contaminants into the ground water and any risks
associated with direct contact of the sludges and soils.
-------
-33-
T-he selected remedy for source control involves the ekcavation
of approximately 1400 cuhic yards of combined soil and sludge.
The material will be placed in the sludge lagoon and solidified
as described in the sludge lagoon selected remedy. The ~ite will
be backfilled and graded with native soils to its previous contour.
Post-excavation sampling will be conducted to ensure that con-
taminants no longer exist in the sludge dump. For the sludge
dump to be considered clean, soils analysis must demonstrate that
contaminants are below compound detection limits. Once this
determination has been made, RCRA post-closure monitoring and
care will not be considered an applicable or relevant and
appropriate requirement. .
Table 12 presents the cost estimates for the sludge dump remedy.
.
-------
-34-
TARLE 9
.
;
.
SLUDGE LAGOON SELECTED REMEDY COST SUMMARY
SLUDGE SOLIDIFICATION, COVER LAGOON, AND MONITOR GROUND WATER
I.)
Initial Capital Cost
-Rernove & Replace Fence
. . . . . . . . . . . . . . .
Stabilize Sludge
R 0 r row F ill
. . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . .
lagoon Cap
Topsoil & Seed
. . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . .
Construction Subtotal
. . . . . . . . . . . . . . .
Contingencies @ 25%
. . . . . . . . . . . . e. . . . . .
Con s t r u ct ion Tot a 1
. . . . . . . . . . . . . . . . . .
Engineering & legal
- .
. . . . . . . . . . . . . . . . . .
Tot alE s t i ma t e d Cap ita 1 C 0 s t
. . . . . . . .
I I . )
Operation and Maintenance (0 & M) Cost
Cap Maintenance
Inspect & Maintain Cap
...............
~roundwater Monitoring
l a bo r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analyses, 6 wells, 4 times!yr
@ S300/analysis - .....................
Total Annual 0& M Cost
. . . . . . . . . . . . .
Present Worth of 0 & M Cost
(30 years, 10% interest)
. . . . . . . . . .
III.)
Total Project Cost
. . . . . . . . . . . . . . . . . . . .
$ 2,000
35,000
49,000
26,000
11,500
$123,500 .
30,bOO
. $154,000
15,UOO
$169,000
$
2,000
1 ,000
7.200
$10,200
196,OOU'
$265,000
-------
/
i
1.)
I I. )
III..)
-35-
TABLE 10
;
.
DRAINAGE DITCH SELECTED REMEDY COST SUMMARY
REMOVE SOIL AND SOLIDIFY .IN SLUDGE LAGOON
I nit; a 1 C ~.e..1.~ ~ 1 C 0 s t s
E x c a vat; 0 nand R a c k f ill
. . . . . . . . . . . . . . . . .
Topsoil .\ Seed
. . . . . . . . . . . . . . . . . . . . . . . . . .
Engineering
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Subtotal
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contingencies @ 25%
. . . . . . . . . . . . . . . . . . . . . .
Tot a 1
. . . . . . . . . . . . . . . . . . . . . . . . . .'. . . .
Operation and Mainteriance (0 & M) tost
Not Applicable
Total Project Cost
. . . . . . . . . . . . . . . . . . . . . .
$1,400
20U
40U
$2,000
500
.
$2,500
$2,500
-------
1.)
11.)
Note:
-36-
TABLE 11
;
.
SEEPAGE PIT SELECTED REMEDY COST SUMMARY
ACCESS RESTRICTIONS AND GROUND WATER MONITORING
Operation and Maintenance (O&~) Cost
Groundwater Monitoring
4 wells, Quarterly SaMpling
@ $300/samp1e .........................
Labor
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Total Annual Operating
. . . . . . . . . . . . . . . . . . . ...
Present Worth of Operating Cost
(30 years, 10% interest)
. . . . . . . . . . . .
Total Project Cost
$55,UOO
. . . . . . . . . . . . . . . . .
$4,~00
1,00U
5,~OU
55,00U
.
No intial capital costs associated with this alternative.
-------
I . )
II.)
Note:
-37-
TABLE 12
SLUDGE DUMP SITE SELECTED REMEDY
EXCAVATE AND SOLIDIFY IN SLUDGE LAGOON
COST SUMMARY
Initial Capital Cost
Excavation and Hauling ........................
Site Restoratil)r'I ..............................
Engineering
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Subtotal
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contingencies@ 251
Tot a 1
. . . . ~ . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . '.'~' . . . . . . . . . . . . . . . . . . . . ~ . . . . .
Total
Pro j e ct. to 0 s t
. . . . . . . . . . . . . . . . . .'. . . . . . . . .
No O&M cost associated with this alternative.
.
f
.
$9,000
5,000
5,000
$19,000 ..
5,000
$24 ,OOU
$24,00U
-------
-38-
2.) Management of Migration
f
.
. The source control remedies'at the site call for the majority
of on-site contaminated soils and sludges to be placed and
solidified in the sludge lagoon, and the lagoon to be properly
closed. The only remaining contaminated material outside the
sludge lagoon will be the residual contaminated soil buried
beneath the seepage pit. Ground water contamination is presently
confined to a small area of land downgradient from the seepage
pit and sludge lagoon. The seepage pit is located approximated
75 feet upgradient from the ~ludge lagoon. Ground water monitoring
will be conducted downgradient of the sludge lagoon, and will
intercept ground water from both the sludge lagoon and the seepage
pit.
Contaminated ground water at the site currently presents little
threat to pubic health or the environment. The long-term threat
associated with the ground water is the potential- impact to the.
LaCrosse River, where site ground water discharges. Site
ground water monitoring and surface water protection will be .
managed through use of alternate concentration limits (ACLs) as.
ground water performance standards. Simply stated, the use of
ACLs will prevent the further degradation of site ground water
and protect LaCrosse River quality.
. -
The use of ACLs at th NEC site will meet the RCRA ground water
requirements in 40 CFR Part 2~4 Subpart F, and the criteria
established in SARA 'Section 121(d)(2)(B)(ii) for application of
ACLs. SARA. stipulates that for ACLs to be employed at Superfund
sites the following conditions must be met:
1.) There are known and projected points of entry of
contaminated groundwater into surface water.
2.) There is no statistically significant increase of
hazardous constituents from ground water into surface
water at the point of entry or where there ;s reason
to believe downgradient accumulation may occur.
3.) The remedial action in~ludes enforceable measures to
preclude human exposure between the facility boundry
and points of entry into the surface water.
"
All three of these conditions are met at the NEC site'. Direct
exposure to contaminated ground water on-site will be precluded
through the use of deed restrictions preventing water well
construction over the contaminated area. NEC owns all the 'property
over the contaminated groundwater up to the discharge point at
the LaCrosse River.
-------
(
4
-i
(
-39-
Conceptually, plume management necessary to protect the LaCrosse
River is based on the following two criteria: .
1.) No statistically significant increase of contamination
to the surface water will occur due to discharges from
ground water at the site; and,
2.) No statistically significant exceedence of an Ambient
Water Quality Criterion in the surface water will be
allowed as a result of the ground water discharge.
The first criteria, which is the more stringent of the two, will be
applied at the NEC site. As the site presently exists, satisfying
the first criteria will more than satisfy the second requirement.
This approach is considered highly protective of the LaCrosse
River, in particularly in light of a 1500 to 1 dilution factor
provided by the river. .
Table 13 lists the indicator compounds used in the RI to characterize
the nature and extent of site contamination, and, where they exist,
their corresponding MCLs and/or chronic toxicity water quality.
criteria (WQC). The ACLs to be developed for the site will satisfy
the appropriate WQC.
Table 13
Proposed ARAR Requi~ements t*
Target List of Compounds
MCLO
WQC~ .
21,900
N/V
N/V
N/V
N/V
N/V
12+
160+
11 0+
1 .
2.
3.
4.
5.
6.
7.
8.
9.
Trichloroetheylene
Vinyl Chloride
1,1 Dichloroethylene
1,1,1 Trichloroethane
Trans 1, 2-Trichlorethane
Fluoride.
Copper
Nickel
Zinc
5
1
7
200
N/V
4000
12
N/V
N/V
t Compounds appear in micrograms per liter
* As. of August, 1987; tar~et list of compounds and values subject
to change
o Maximum Contaminant level from Safe Drinking Water Act.
. Ambient Water Quality Criteria For Long Term Protection Of
Aquatic Life
+
Function of Water Hardness; Value Given for Hardness Measured
at 100 mgl1
N/V = No Value
-------
-40~
.
F
The mechanics of a ground water monitoring program will be
specifically addressed in the remedial design (RD) phase of the
. project. However, the basic ground work for establishing an
effective monitoring program will be described in the following
discussion. .
Initially, baseline groundwater quality levels will be developed
to quantify present site contamination. These levels will be
determined through sampling of compliance monitor wel Is for four
consecutive quarters over a year's time. The monitoring wells
used to determine and subsequently verify ground water quality
will be located downgradient from the sludge lagoon and in
direction of the river to which the plume discharges. The
frequency, timing, and protocol will be developed in a Quality
Assurance Project Plan (QAPP) with the objective of gatheriny
representative data of ground water quality and its variation over a
year's period. A statistical test which accounts for the variation
of the data will be employed to measure compliance, and will be
equivalent to or the same as the "Cochran's Ap~roximation to the
Behrens-Fisher Student's t-test provided in 40 CFR Part 264 ..
Subpart F, Appendix IV. This test will be wor.kable only if the
approved sampling protocol and analysis are strictly adhered to.
After baseline water quality and its statistic is derived,
suhsequent compliance monitoring can be. compressed to the baseline
statistic. For subsequent monitoring events a new statistic can
be developed and compared to the baseline statistic. If the new
statistic exceeds the baseline statistic at the 95% confidence
limit there is high probability that a statistically significant
increase of a parameter(s) has ocurred. The statistics may apply
to each compound on Table 13 or to the sum of the compounds or
to hoth as described in the RD stage.
If any exceedance occurs which is statisfically significant at
the 95% confidence limit, confirmation sampling and analysis will
occur. If subsequent sampling confirms a statistically significant
increase in the concentrations of the compounds of interest, .
a Remedial Action Plan (RAP) will be developed over a limited
period of time as determined in'~he RD stage. While the RAP is
being developed, monitoring at an increase frequency will occur.
Based on the frequency of statistically significant increase of
the concentrations of the parameters monitored in the ground
water, EPA will make a decision regarding the need to implement a
remedial action. This decision process will be delineate~ in the
RD stage. At no time will discharges to the LaCrosse River exceed
acute water quality criteria for the protection of aquatic life.
q
-------
-41-
VIII.
Statutory Determinations
.
;
.
1.) Protectiveness
The selected remedies at the NEC site satisfy the remedial
objectives identified in the FS to minimize risks to public
health and the environment. Currently. potential risks on-site
result from direct contact exposure to contaminated sludge and
soil and ingestion of contaminated ground water.
Contaminated soil occuring in the drainage ditch and contaminated
s011 and sludge in the sludge dump area will be excavated and
solidified in the sludge lagoon. The sludge lagoon will be
provided with a RCRA specified cover. and inspected and maintained
for a 30 year period. The present cover over the seepage pit
will be evaluated to determine whether it meets the RCRA criteria
for cover design. and any modifications necessary to bring it
within the specifications will be conducted. .
These remedial measures will effectively minimize the
direct human cont~ct with the contaminated sludge and
addition to these measures. deed restrictions will be
. t~e property to prevent construction atop or into the
risks of
soil. In
imposed on
impoundments.
.
"
Ground water contamination at the site will be minaged through"
the use of alternate concentration limits (ACLs) as site specific
ground water. performan~e standards that are protective of the
river. The current state of ground water contamination at the
site presents little or no threat to public health or the environ-
ment. As demonstrateg in the EA. the only possible scenario for
at t a i n i n g the 1 x 1 0 - can c err i s k val u eon - s i t,e w 0 u 1 d bet h r 0 ugh
ingestion of two liters per day of ground water for a lifetime from
the most highly contaminated monitoring well. which is considered
hypothetically by presenting an unlikely exposure event. The
property on which ground water contamination exists is not used
for private. municipal. or industrial water supplies.
Ground water at the site discharges into the LaCrosse River. The
EA has shown that inconclusive dif.ferences exist between upstream
and downstream concentration of contaminants. This will be further
tested in the RD on the'site. In addition. the EA also concludes
that the current level of contaminants in both sediments and surface
water of the LaCrosse River does not present an adverse exposure
risk to either humans or aquatic species.
Consequently. present site conditions allow for the application
of ACLs as described in SARA Section 121(d)(2)(B)(ii). Should
an ACL be met or exceeded at anyone of the compliance points
within a prescribed statistical ranye. a more frequent monitoring
-------
-42-
program will commence to confirm or reject the initial results.
A response action will then be undertaken to return ground water
quality to the accepted level (i.e. less than the ACLs)~ The use
of ACLs will effectively manage site ground water contamination
an~ minimize risks to public health and the environment., "
2.)
Consistency With Other Laws
Table 14 lists the applicable or relevant and appropriate federal
and state requirements (ARARs) that are considered for the NEC
site and satisfied throuyh the selected remedies.
The sludge lagoon will be employed as final placement of con-
taminated materials from the drainage ditch and the sludge dump
site. Several federal RCRA requirements are relevant and appro-
priate to the implementation of this remedy. The sludye lagoon
cover must meet the criteria for landfill covers as described in
40 CFR ~264.310. This reyulation re4uires that covers minimize
the migration of liquids through the cover, function with minimum
maintenance, promote drainage and minimize erosion to the cover,
accommodate settling and subsidence, and have a permeability less
than or equal to the permeability of natural subsoils or bottom
liner.
.
Post-closure monitorin~ and care of the sludge lagoon will be
required as described 1n 40 CFR ~264.117. This will require
periodi~ -inspections and maintenance of the cover, as w~ll as
implementation of a ground water monitoring program.
As required by 40 CFR ~~art 264 Subpart F, a ground water protection
standard mu1t be established when hazardous constituents enter,
the ground water. The constituents may not exceed the background
concentrations, MCLs, or the established ACL at the point
of compliance. At the NEC site, ground'water compliance monitoring
will be undertaken with the use of ACLs as ground water performance
standards. Application of ACLs on-site will be conducted within
the meaning and substance established in 40 CFR ~264.94(b) and SARA
Section 121(d)(2)(B)(ii).
b
The present ground water monitoring wells downgradient of the sludge
lagoon and seepage pit will be emp~oyed as the compliance monitoring
points for the ACLs.
,-
The seepage pit must satisfy closure and post-closure requirements
of 40 CFR Part 264 Subpart G.. Specifically, the cover over the
seepage pit must meet the criteria established in 40 CFR 926A.310.
-------
I . )
A. )
B. )
I I . )
A. )
B. )
o
-43-
TABLE 14
NEC Selected Remedies' ARARs
Federal Requirements
Closure and Post-Closure Requirements
40 CFR Part 264 Subpart G
1.) Closure performance
2.) Post-closure care
3.) Capping
4.) Clean closure
5.) In-place closure
standard
Ground Water Protection
40 CFR Part 264 Subpart F
1.) Groundwater,protection standard
2.) Alternate concentration limit
State of Wisconsin ,Requirements
Closure and Post-Closure Requirement
1.) Clos'ure
2~) Post-closure
Ground.Water Protection
f
.
~264.111
~264.117
~264.228(a)
~264.228(a)(1 )
~264.228(a) (2)
~264.92
g264.94
.
N'R 1 81 . 4 2 ( 8 )
NR 181.42(9)
NR 140
-------
-44-
.
;
This requirement may necessitate modifications to the"existing
cover. Investigation of the present cover will be undertaken
during the remedial design phase. Post-closure monitoring and
care of the seepage pit will be undertaken as described in 40 CFR
g264.117. This will require periodic inspections and maintenance
of the seepage pit cover, as well as implementation of a ground
water monitoring program. Ground water monitoring will be con-
ducted as described above in the application of ACLs.
The drainage ditch and sludge dump site will be "clean closed" as
provided in 40 CFR ~264.228(a)(1). At which time, post-closure
requirements will no longer be relevant and appropriate. Extensive
post-excavation sampling will be undertaken at both the drainage
ditch and sludge dump site. The analytical results must indicate
non-detectable levels of indicator contaminants for the units to
be ~onsidered "clean closed".
Two Wisconsin DNR requirements are considered applicable or relevant
and appropriate to the NEC site. Ground water contamination at
the site will be governed by Chapter NR 140 - Ground Water Standa~ds,
and closure and post-closure requirements will be applied as
descrihed in Chapter NR 181 Hazardous Waste Management (Surface
Impoundment Closure Requirements).
Wisconsi~ DNR closure requirements are found in NR 181.42(8),
which essentially mirrors the federal RCRA closure requirements in
40 CFR &264.111. The.state closure requirements will be met for the
sludge lagoon,seepage pit, drainage ditch, and sludge dump site
as described above for RCRA closure requirement (40 CFR Part 264
Subpart G). Post-closure Wisconsin DNR requirements are described
in NR 181.42(9), which necessitates the long-term care and moni-
toring of surface impoundments and landfills where hazardous
materials are closed in-place. This requirement. essentially
mirrors the federal RCRA post-closure requirement in 4u CFR ~264.117.
The state post-closure requirements will be met for ~he sludge lagoon
and seepage pit as described above for RCRA post-closure requirement
(40 CFR Part 264 Subpart G). The drainage ditch and sludge dump site
will be "cleaned closed", and not required to undertake post-closure
monitoring activities.
a
NEC ground water contamination will conform and be regulated by
Wisconsin DNR Chapter NR 140 (Ground Water Quality Standards).
This requirement is similar to the federal RCRA requirements in
40 CFR ~264.92. such that it specifically allows for the'
estahlishment of alternate concentration limits (ACLs). Consequent-
ly, with the application of ACLs at theNEC site, state ground
water quality requirements (NR 140) will be satisfied.
-------
.'
.
-4S-
3.)
Rationale For Remedies Selection
F
.
The remedies selected for the NEC site represent the best .balance
of the criteria established f~r alternatives comparison. In
addition, the selected remedies achieve the statutory preference
for remedial actions to utilize treatment to permanently and
significantly reduce the volume, toxicity, or mObility of the
hazardous substances.
The four waste units on-site were analyzed separately in the
"detailed evaluation" section of the FS. A remedy was selected
for each unit based on the evaluation. Although the remedies per
waste unit were selected individually, they are interdependent
upon each other for implementation, and in achieving the desired
remedial objective.
The following section describes, individually, the rationale for
the selection of each of the four remedies in terms of the best
combination of ~ffectiveness, implementability, and co~t. and, in
addition describiny how the remedy satisfies the statutory
perference for treatment.
.
a.) Sludye Lagoon
o
A total of .six alternatives were evalu~ted in the final "alterna-
tives array" for the sludge lagoon. All but the "no action"
alternative met the remedial objective of minimization of cont~ct
with the sludge and pr.evention of contact with and use of contami-
nated ground water.. 'The "no action" alternative was rejected
because it would be totally ineffective in' protecting human
health and the environment. The present site condition would
continue, suc~ that the threat of direct human contact with
contaminated sludge and soil would remain, and ground water
contamination would continue unmonitored. In addition, neither
state and federal closure requirements, nor ground water quality
standards would be met.
~
The remaining five alternatives meet the remedial objective.
Alternative 2 proposes to cap the sludge lagoon and monitor
ground water, this alternative wa9. rejected because it failed to
effectively control the source of ground water contamination,
casting doubts on the lony-term reliability of the remedy.
Furthermore, this remedy would not satisfy federal and state
closure requirements that necessitate the need to control or
minimize the post-closure escape of hazardous materials to ~he
extent necessary to protect human health and the environment.
The remaining four alternatives essentially satisfy the comparison
criteria of implementability and effectiveness to various degrees.
The alternatives are as follows: Alternative 3 - solidify
sludye, cap the lagoon, and monitor ground 'water (apply ACL
-------
.
.
.
-46-
;
performance standards); Alternative 4 - excavate sludge ann
dispose off-site, and pump and treat ground water; Alter~ative 5
- excavate sludge and soil for off-site disposal, and pump and
treat ground water; and, Alternative 6 - excavate sludge and
dispose off-site, and monitor ground water.
Under Section 121 of SARA, it states that the off-site transport
and disposal of hazardoUS Materials without treatment is the
least preferred option where practicable treatment technologies
are available. In analyzing the remaining four alternatives, the
statutory preference for utilizing treatment technologies was a
priMary decision making factor in additon to the cost of remedy
implementation.
Of the remaining four alternatives, Alternative 3 is considered
the Most appropriate remedy, such that it satisfies the statutory
preference for treatment through the use of sludge solidification
that will permanently and significantly reduce the present
leachability of .the waste. Additionally, it is the least costly
of the remaining alternatives..
Alternatives 4, 5 and 6 propose for source control, the off-site
transport and disposal of sludge from th.e sludge lagoon without
utilizi.ng treatment.. As stat~d above, SARA considerS this th~
least preferred option where treatment technologies are available.
The metal hydroxide sludges in the lagoon are innately immobile in
a soils environment~ the solidification of those materials will
ensure thelong-ter~ effectiveness of source control. Alternative
3 provides for th~ utilizat.ion of. treatment on-site that is a
permanent solution, and is protective of human health and the
environment.
Ground water contamination on-site exists only downgradient of
the sludge lagoon over a relatively small area of land. The
contamination as it exists presently is not threatening any
public, private or industrial water supplies. The EA demonstrates
that site ground water contamination is not presently adversely
impacting the quality of the laCrosse River. Consequently, the
use of ACLs' on-site as ground wat~r performance standards, as
Alternatives 3 and 6 propose, is considered an appropriate and
effective measure to manage ground water in the lony-term.
In short, based upon 1) the utilization of treatment technologies
for leachibility reduction, 2) the long-term effectiveness"in
providing protection to human health and the environment, and 3)
the cost savings relative to the remaining alternatives, Alternative
3 is considered the appropriate remedy for the sludge lagoon and
management of site ground water contamination.
o
v
-------
.
.
.
-47-
b.) Drainage Ditch
f
.
D
Contaminated soil in the drainage ditch presents a health threat
t~ humans coming into direct contact. The remedi~l objective is
to prevent human contact with the affected soil. Essentially
four alternatives exists for possible remedy. The "no action"
alternative does nothing to reduce or minimize the potential
health risks. The drainage ditch would remain in it present
condition with no controls over contaminant migration or direct
human contact. In addition, this alternative does not comply
with the relevant and appropriate federal and state closure
requirements.
Consequently, the "no action" alternative was rejected as a
possible site remedy for the drainage ditch.
u
The remaining three alternative satisfy the stated remedial
objective. Alternative 2 proposes to restrict access to the area
through construction of a fence around the drainaye ditch. This
alternative would reduce the likelihood of casual human contract,
however, the degree of effectiveness over the long-term is .
questionable. The contaminated soils would still remain "in.
place" exposed to the surface, and over the lqng-term there would
be no quarant~e that such access restriction would be effective.
T~is alternative doei nots~tisfy the statutory perference for -
treatment of haza.rdous constituents to permanently and signific~ntly
reduce toxicity, mobility, or volume. In addition, Alternative 2
does not satisfy feder~l and state closure requirements to minimize
or eliminate post-closure escape of hazardous constituents to the -
extent to protect human health and the environment. Consequently,
this alternative was rejected as. a possible remedy.
The two remaining alternatives essentially attain the same degree
of~ffectiveness and implementibi1ity for remedy at the drainage
ditch. Alternative 3 proposes the excavation of contaminated
soil and subsequent solidification in the sludge lagoon, and
Alternative 4 calls for the off-site transport and disposal of
contaminated soil. Alternative 3 is considered the most appropri-
ate remedy for drainage ditch based on the following rationale.
First, the remedy incorporates the. use of treatment as a principle
element. . As described in the selected sludge lagoon remedy,
solidification of the sludge lagoon will permanently and signifi-
,cantly reduce the leachibility of the hazardous constituents.
Second, Alternative 3 does not employ the use of off-site disposal
without treatment as.does Alternative 4, which is considere~ the
least preferred option as stated in SARA. And, third, both
Alternative 3 and 4 are protective of human health and the environ-
ment, and satisfy applicable or relevant and appropriate federal
and state requirement, however, Alternative 3 is an order of
magnitude less in cost than Alternative 4.
~
v
-------
.
.
.
-48-
In short, Alternative 3 provides the most cost effective means of
remerliating the drainage ditch contaminatio~ for the protection of
human health and the environment in addition to satisfyin9 the
stated preferences of SARA.
,
~
c.) Seepage Pit
Contamination at the seepage pit is confined to residual soil
contamination beneath the bottom of the pit and subsequent ground
water contamination. The remedial objective is "to minimize
contact with buried contaminated soils and prevent use of ground
water." A total of four alternatives were analyzed in the final
array to address the risk to human health and the environment.
The "no action" alternative allows the seepage pit to remain in
its present condition. No controls over future usage of the pit
would be implemented, in addition, future monitorin~, maintenance,
and inspection of the seepage pit would not be undertaken. The
"no action" alternative is rejected because of the followiny
factors: 1) uncertainties of the long-term impact and consequenc~s
of the waste on public health and the environment; 2) it does not
satisfy federal and state relevant and appropriate requi~ements;
3) it does not achieve the remedial objective; and 4) it does not
comp}y with .the statutory preference for "remedies that utilize
permanant solutions. .."
The remaining three alternatives meet the remedial objective for
the seepage pit, and Satisfy the relevant and appropriate state
anrl federal requirements. Alternatives 2 and 4 entail the excavation
of contaminated soil and transport and disposal off-site, Alternative
4 also includes implementation of a ground water pumping and treat-
ment system. Alternative 3 involves the inspection of the present
cover over the seepage pit to determine if modifications are
necessary, obtaining deed restrictions on the property to preclude
future land development, and implementing a groundwater monitoring
program. Groundwater monitoring for this remedy would actually
b~ undertaken downgradient to the sludge lagoon were ACLs would
be applied.
The seepage pit poses two potential threats to human health and
the environment. First, the direct human contact with contaminated
soil, and second, the continuation as a source of ground water
contamination. The contaminated soil in the seepage pit is
buried beneath fifteen feet of soil, which realistically pr.ec1udes
casual human contact. Alternative 3 provides an effective means
of further ensuring and minimizing the potential of direct contact
without employing off-site disposal.
o
~
~
In summary, Alternatives 2 and 4 were rejected in favor of Alter-
native 3 for the following two reasons. Alternative 3 meets .the
-------
/ - ,--,'
'. "
.
1)
S'
(]
()
9
,
(
.
.
, .
-49-
remedial objective and satisfies the federal and state relevant
and appropria~e requireMents at a cost less than eith,r Alternative
2 or 4; and Alternative 3 provides effective means of. more than
adequately protecting human health and the environment without
utilizing off-site transport and disposal. as do. Alternatives l
and 4. '
Treatment technologies were screened out in the FS prior to the
Udetai1ed evaluation of alternativesu for the seepage pit. due
to conditions surrounding the pit. Treatment technologies are
considered impracticable. and a costly and inefficient means of
remediating the site for the following reasons. First. the
contaminated soils beneath the seepage pit are fifteen feet below
grade and realistically presents no threat of human contact.
Second. the contaminated soils are within the water table and are
not a source of further degradation of water quality. Finally. the
management of ground water through the application of ACLs has
been dee~ed appropriate given the conditions at the site and the
negligible effect on surface water. The seepage pit is approximately
seventy-five feet hydraulically upgradient from the sludge lagoon.
ground water co~p1iance monitoring points for the seepage pit
will be conducted downgradient from the sludge lagoon.
.
Consequently. the seepage pit presents little endangerment as .it
presently exists. warranting minimal remedial' action to appropriately
address the pit.
d. )
Sludge Dump Site
The remedial object1ve at the sludge dump is to minimize contact
wi.t~ the' buried sludge. No ground water contamination presently
'has been attributed to the sludge dump. A total of five alter-
natives were evaluated as potential remedies.
The uno action" alternative would allow the site to e~ist as it
does presently with the exception of deed restrictions preventing
future land development. The "no actionu alternative was rejected
as a remedy because the alternative would be unreliable and
ineffective in protecting human health and the environment. and
because the alternative does not comply with federal and state
closure and post-closure requirements (ground water monitoring
would be "ecessary). Additionall~. the alternative does nothing to
ensure a permanent solution. .
Alternative 2 entails the installation of a RCRA cover over the
sludge dump. Alternative 2 is rejected as a possible remedy due
to the following concerns. First. this alternative propos&s that
no ground water monitoring be conducted at the site. This would
not satisfy 40 CFR Part 264 Subpart F. which requi ries the implement-
atiQn of a ground water monitoring program when hazardous materials
are left "in place". Second. as stated in Section 121(b) of SARA.
those reMedial actions that utilize treatment to permanently and'
-------
"
.
, .
-50-
.
s i g n if;" c ant 1 y red u c e the vol u m e- . to x i c i t Y 0 r the mobil :i t y 0 f
hazardous substances are given preference over those remedial
actions that do not. Alternative 5 in the "sludge dump sfte
array" better satisfies this statutory' pr'eference. Finally. this
alternative would be unrealiable and questionably effective on
the long-term in light of the fact that it proposes no ground
water management program.
c.
~
Alternative 3 and 4 propose essentially identical remedies. which
involves excavation of the contaminated material (i.e sludge
and / 0 r so i 1) and t ran s po r t and d i s po sa 1 0 f f - sit e . A 1 t ern at i ve 5
involves the excavation of all contaminated material from the
sludge dump and solidification of the material in the sludge
lagoon. Alternative 5 is selected over Alternative 3 and 4 for
the following reasons. First. Alternative 5 explicitly satisfies
the statutory preferences for treatment as a principal element
(through sludge solidification). which alternative 3 and 4 do
not. Second. Alternative 5 achieves a permanent solution that is
protective of human health and the environment without utilizing
off-site transport and disposal (that does not i nvol ve treatment)..
such as Alternatives 3 and 4. Finally. Alternative 5 meets the
remedial objpctive and satisfies all relevant and appropriate
federal and state. requirements at a cost an order of magni~ude
less than either Alternative _3 or 4.
[}
.)
\"
-------
~
. .
.
. .
-
D
~
[1
D
q
I
.
~. .
.
-51-
IX.
Projected Schedule For NEC Cleanup
Sign Record of Decision
Project Remedial Design Complete
Initiate' Ground Water Monitoring
Program
Initiate Remedial Action
Construction
Construction Complete
EPA.Evaluates Ground Water
Monitoring Program
.
f
.
September 30, 1987
February 1, 1988
February 15, 1988
March 1, 1988
June 1,1988
February 15, 1993
.
------- |