United States         Office of
Environmental Protection    Emergency and
Agency            Remedial Response
         03&>
EPA/ROD/R07-90/«4+
September 1990
Superfund
Record of Decision:
Lindsay Manufacturing, NE

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 REPORT DOCUMENTATION
        PAGE
1. IWOHTMQ.
     EPA/ROD/R07-90/041
                                         1 Rod«tenr« AccMttan No.
                                                                  t. fbportOMi
   SUPERFUND RECORD  OF DECISION
   Lindsay Manufacturing,  NE
   First Remedial Action - Final
                                                                         9/28/90
                                                                 *. fertomting OrginiBtfon Rtpl. No.
 I. riitnnnlno ~rj»inlii
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EPA/ROD/R07-90/041
Lindsay Manufacturing, NE
First Remedial Action - Final

Abstract  (Continued)

already underway as a result of the interim action.  The primary contaminants of concern
affecting the soil and ground water are VOCs, including PCE; and metals including
chromium and lead.

The selected remedial action'for the site includes vacuum extraction of volatile organic
compounds from soil, followed by a carbon adsorption filter system before vapor
emission, with full-scale implementation based on the results of a pilot study; onsite
pumping and treatment of ground water using precipitation and flocculation, followed by
sedimentation of the flocculant, with onsite discharge to surface water, and disposing
of dewatered solid residuals offsite at a local landfill.  The estimated present worth
cost for this remedial action is $3,006,600, which includes an annual O&M cost of
$636,000 for 5 years.

PERFORMANCE STANDARDS OR GOALS';  cleanup levels are based on the more stringent of
either SOWA MCLs or State regulations.  These levels will reduce lifetime cancer risks
to between 10 4 and 10 6 for carcinogenic compounds, and the hazard index  (HI) to less
.than 1 for non-carcinogens.  Chemical-specific ground water cleanup goals include PCE 5
ug/1 (proposed MCL), chromium 0.05 mg/1 (MCL), and lead 0.05 mg/1 (MCL).  Specific
cleanup levels for soil were not provided.

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           RECORD OF DECISION



      LINDSAY MANUFACTURING COMPANY



            LINDSAY,  NEBRASKA
             SEPTEMBER 1990
               Prepared by



THE U.S. ENVIRONMENTAL PROTECTION AGENCY



               REGION VII



           KANSAS  CITY,  KANSAS

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           LINDSAY MANUFACTURING  COMPANY SUPERFUND SITE
                  RECORD OF DECISION  DECLARATION


SITE NAME AND LOCATION

     Lindsay Manufacturing Company Site
     Lindsay, Nebraska  (Platte County)

STATEMENT OF BASIS AND PURPOSE

     This decision document presents the selected remedial action
for the Lindsay Manufacturing Company site, in Lindsay,  Nebraska,
chosen in accordance with the Comprehensive Environmental
Response, Compensation and Liability Act of 1980 (CERCLA), as
amended by the Superfund Amendments and Reauthorization Act of
1986 (SARA), 42 U.S.C. § 9601 e£ sea.. and, to the extent
practicable, the National Oil and Hazardous Substances Pollution
Contingency Plan  (NCP), 40 CFR Part 300.

     This decision is based on the administrative record for the
Lindsay Manufacturing Company site.

     The United States Environmental Protection Agency (EPA) and
the State of Nebraska (Department of Environmental Control -
NDEC)  agree on the selected remedy.

ASSESSMENT OF THE SITE

     The actual or threatened release of hazardous substances at
or from this site, if not addressed through the implementation of
the response action selected in this Record of Decision  (ROD),
present an imminent and substantial endangerment to public
health, welfare, or the environment.

DESCRIPTION OF THE SELECTED REMEDY

     The .Remedial Investigation/Feasibility study (RI/FS),
conducted by the Lindsay Manufacturing Company from January 1989
to August 1990 at the Lindsay Manufacturing Company site,
identified ingestion of contaminated ground water and/or
inhalation of contaminants released during use as a principal
threat to residents living near the site.

     In addition, available data shows elevated concentrations
("hot spots") of volatile organic compounds in soils as  a
principal threat to the ongoing contamination of ground  water.

     Detectable levels of zinc, cadmium, lead, iron and  sulfate
have been identified in the ground water.  Organic contaminants,
including dichloroethylene, tetrachloroethylene and
trichloroethane have bean detected in the ground watar.  These
organics have been detected on-site in the soils in the  central

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drainage ditch, near the northeast corner of the main plant
building, and  in the central northern portion of the site.

     This remedy will address the principal threat posed by the
contaminants in the ground water by restoring the ground water to
acceptable quality (Safe Drinking Water Act Maximum Contaminant
Levels-MCLs and State of Nebraska cleanup levels established
under Title 118, Ground Water Quality Standards and Use
Classification) by the extraction and enhanced treatment of
contaminated ground water.  In addition, the remedy may reduce
the threat of  continued contamination of the ground water from
the soil source areas if vapor extraction of volatile organic
compounds from the soils proves practicable.

     The major components of the selected remedy for the affected
ground water and soil include the following:

     o    A pilot study to evaluate the practicability of vacuum
          extraction of organic compounds from contaminated soil.

     o    If determined to be practicable by EPA and/or NDEC,
          design and implementation of full scale soil vapor
          extraction system based on pilot study data.

     o    Enhancement of the existing ground water extraction and
          treatment system by either increasing the volume of on-
          site pumping from the existing extraction wells or by the
          installation of an additional interceptor (extraction) well.

     o  •  Utilization of the existing ground water treatment
          facility to remove contaminants from the collected
          ground water.

     o    Installation of additional ground water monitoring
          wells near irrigation well #54278 to further delineate
          the ground water contaminant plume.

     o    The monitoring of the ground water collection/treatment
          system and the ground water contaminant plume during
        ,  ground water remediation activities.

     o    If appropriate to protect human health, EPA and NDEC
          will evaluate options, as part of implementation of the
          ROD, to ensure that drinking water wells are not
          installed in areas of the contaminant plume on and off
          site.
STATUTORY DETERMINATIONS

     The selected remedy is protective of human health and the
environment, complies with Federal and State requirements that
are legally applicable or relevant and appropriate to the
remedial action, and is cost-effective.  This remedy utilizes
permanent solutions and alternative treatment (or resource

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recovery) technologies to the maximum extent practicable, and
satisfies the statutory preference for remedies that employ
treatment that permanently and significantly reduces toxicity,
mobility, or volume as a principal element.  Because this remedy
nay result in hazardous substances remaining on-site above levels
that allow for unlimited use and unrestricted exposure, a review
will be conducted no less often than every five years after
commencement of remedial action to ensure that the remedy
continues to provide adequate protection of human health and the
environment.

     Subject to the outcome of the pilot study, the agency will
consider reopening the ROD or amending the ROD if warranted,
otherwise the agency will proceed with the selected remedy.   If
soil vapor extraction is determined not to be practicable, the
Agency will consider an additional study to evaluate other
treatment or source control technologies to reduce or eliminate
the source(s) of contaaination to ground water.
        Mortis Kay                                 Date
        Regional Administrator
        U.S. EPA - Region VII

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                                                                           -  •  -'

                       ATE     OF      NEBRASKA
                               DEPARTMENT OF ENVIRONMENTAL CONTROL
                  KAY A. ORR
                   GOVERNOR
                                        September 21. 1990
       DENNIS CRAMS
           DIRECTOR
                                                                          •>
                                                                           r
                                     SE° ,? '  1990
                                         ADMINISTRATOR
CC -
Mr. Morris Kay
Regional Administrator
EPA Region VII
726 Minnesota Avenue
Kansas City. Kansas 66101

Dear Mr. Kay:

     Upon consideration of the Administrative Record and the draft Record of
Decision (ROD), the Nebraska Department of Environmental Control (NOEC) concurs
with the Environmental Protection Agency's remedy selection for the Lindsay
Manufacturing Company Superfund site.

     NOEC understands that the selected remedy will provide enhancement of the
current pump and treat system to remove organic and inorganic contamination in
the groundwater which poses a threat to human health and the environment.  In
addition, the selected remedy will include a pilot study to determine the
practicability of soil vapor extraction to treat soils contaminated with
volatile organic compounds.  The selected remedy will meet all state
requirements.

     NOEC appreciates the opportunity for oversight of the RI/FS and input
during the remedy selection process.   NOEC also appreciates the support of EPA
during the oversight activities.
                                        Dennis Grams. P-E.
DG/RJ/ls
                                                                       RECEIVED

                                                                      SEP 1 ? 1990
                                                                           SECTION
             P.O. BOX 99922, LINCOLN, NEBRASKA 69509-8922. PHONE (402)471.2186
                     AN EQL'AL OPPORTUNITY'AFFIRMVTIVF ACTION FMPIOVFR

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                        TABLE OF CONTENTS



SECTION    TITLE                                              PAGE

DECLARATION                                                   i

  I.      SITE NAME,  LOCATION, AND DESCRIPTION                 1

         A.  Location and Address 	   1
         B.  Area and Topography of Site 	   1
         C.  Adjacient Land Uses 	   1
         D.  Surface and Subsurface Water Resources 	   2
         E.  Surface and Subsurface Features 	   3

  II.     SITE HISTORY AND ENFORCEMENT ACTIVITIES              3

         A.  Site History 	   3
         B.  Interim Remedial Acitons 	   4
         C.  NPL Listing 	   5
         D.  Remedial Investigations 	   5

  III.    HIGHLIGHTS  OF COMMUNITY PARTICIPATION                6

  IV.     SCOPE AND ROLE OF RESPONSE ACTION                    7

         A.  Role of Remedial Acton in Site Clean Up Strategy 7
         B.  Scope of Problem Addressed 	   8

  V.      SUMMARY OF  SITE CHARACTERISTICS                      9

         A.  Soil* 	   9
         B.  Ground  Water	  11
         C.  Contaminant Fate and Transport 	  13

  VI.     SUMMARY OF  SITE RISKS                               13

         A.  Human Health Risks 	  13
         B.  Environmental Risks	  18

  VII.    DESCRIPTION OF ALTERNATIVES                         19

  VIII.   SUMMARY OF  COMPARATIVE ANALYSIS OF ALTERNATIVES     26

  IX.     SELECTED REMEDY                                     30

  X.      STATUTORY DETERMINATIONS                            33

  XI.     RESPONSIVENESS SUMMARY                              36

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 I.  SITE NAME, LOCATION AND DESCRIPTION

 A. Location and Address

     The Lindsay Manufacturing Company facility (the "site")  is
 located in the village of Lindsay, Nebraska, in Platte County.
 The site is located in the southeast quarter of the southwest
 quarter of Section 17, Township 20 North, Range 3 West, Platte
 County, Nebraska (Figure l-l).  The Village of Lindsay lies on
 the east boundary of the Nebraska sandhills and the local region
 is characterized by rolling and dissected loess plains.  The site
 is surrounded on the north and east by farmland and on the south
 and west by the village of Lindsay.

 B.   Area and Topography of Site

     The site occupies approximately 42 acres and has been
 selectively leveled and stabilized.  Drainage swales have been
 filled and some surfaces paved for transportation and equipment
 storage.  A loessal slope on the east half of the site has been
 locally incised for construction of the maintenance and final
production buildings (Figure 1-2).

     The site is approximately 1,300 feet long (north to south)
 and the width ranges from approximately 1,570 feet at the north
end of the property to 1,100 feet at the south end.  The surface
gradient across the property drains to the vest and ranges
 from .023 ft/ft in the central drainage channel to .053 ft/ft
across the south property boundary.  The site is situated in a
 relative topographic low created by Shell Creek and its tributary
drainages.  The average elevation of the site is approximately
 1,670 feet above mean sea level, and local relief ranges from
 1,650 to 1,800 feet above mean sea level.

C.   Adjacent Land Uses

     The site is bounded on the north by farmland, on the east by
Lindsay town limits and farmland, on the south by State Highway
 91 and a residential area of Lindsay, and on the west by a
tributary to Shell Creek, its greenbelt and a residential area of
Lindsay.  The drainage channel is dry, except during storm runoff
and when receiving plant vastevater discharge.

     Total population of Lindsay, Nebraska in 1980 was 383
people.  Results from the Natural Resources Commission in
conjunction with the Census board state an average population of
 392 for the years 1908 through 1986.  The population center is
 located within 0.3 miles vest and south of the Lindsay
Manufacturing western property boundary.  Three schools serve the
 Lindsay area.  One public elementary school has an average
enrollment of 35 students.  A second public elementary school has
 an average enrollment of 151 students.  The high school is
private and has an average enrollment of 109 students. The high
school and elementary schools are located approximately 0.25

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miles west of the site boundary.  No hospitals, clinics or
retirement centers are known to exist within a two mile radius of
the  site.

     Land use within the city limits is primarily residential
with the exception of the Lindsay Manufacturing site and a
community business and general commerce area located southwest of
the  site.  A public recreational and utilities area is located
approximately 0.2 miles southwest of the site.  The utilities
area consists of the town public sewage treatment plant and
ponds.  Use of the area located within a two mile radius of the
Lindsay town limits is primarily agricultural with an average of
three farmsteads per square mile.

     The following federally listed threatened and endangered
species may occur within 3 miles of the site:

     Listed Species                         Expected Occurrence

Bald Eagle (Haliaeetus leucocephalus)       Migration
Peregrine Falcon (Falco peregrinus)         Migration
Western Prairie Fringed Orchid              Tall-grass prairie or
(Platanthera praeclara)                     meadow with high water
                                            table

     There is no critical habitat within 3 miles of the site.
Both Shell Creek and Dry Creek are considered to be wetlands by
the USDA Soil Conservation Service.

D.   Surface and Subsurface water Resources

     The site is in the upland drainage area of Shell Creek.  The
western boundary of the site is a tributary drainage to Shell
Creek (Dry Creek) which historically has had intermittent flow
only during precipitation runoff events and permitted plant
discharges.  Since June 1987 this tributary has received nearly
continuous discharge from the interim ground water remediation
operation.  The treated waters are monitored by the facility's
NPDES permit.
          X
     Groundwater at the site can be generally characterized as
occurring in a sand and gravel aquifer bounded on the top and
bottom by lower permeability units, which include the upper
loessal soils and the lover Niobrara Formation.  SOB* ground
water also occurs in these upper and lower units, but water
movement in than is retarded by the fine-grained nature of these
units.

     Groundwater flow in the vicinity of Lindsay, Nebraska is
generally to the south.  Localized influences of Shall Creek and
high capacity irrigation vails affect ground water flov in this
area.  The aquifer thickness ranges from 35 to 50 fast.  The
average ground water flov velocity is about 3 feat par day.  In
addition, the shape of the vater table indicates that the ground
water contributes to flov in Shell Creek in th* vicinity of

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I
I
                                                  Lindsay
                                                  Manufacturing Sitt j
                                                              *
                                                                           N
                                                           0           5000
                                                                       i
                                                             teal* In F««t
T 5
      USGS
       2/n/«o
  FIGURE  I - •
    Vicinity Map
Dames & Mocx?

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!
•»
                          too
Seata in F««t
                                                              FIGURE  1-2
                                                                Sit» Layout
                                                 Lindsay Manufacturing Site
                                                 	Dames & Moore

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   I«»»«
                                                Dark graynn orown B tgn frown. Mabto B Srm. «•« dramad. trcraaimg day
                                                    I w* dap*, minor cataaroui araat. SeaoarM mnor ffwi An* tand ianaa«
e
e
s
                                                Predominantly Silt Loam
                                                       nd Pint)
                                                   MOiyi: IQM ID dM BTOM. gray. o»«. tow B
                                                toftiA« Mttnd MQ ind rv ArinlnQ,
                                                tand grakv. quire and Md*ar. rounded:
                                                                pnr)fiH«Bly quartt. mnor t»ttpar and mate
Undtffamntlartad Flna Sanda . St»l CnMk Vtltoy
               Undiffartrtiatad
               Fine Sands
                                                               Sand* and Qravrta
                      a rawdad. peorty B Ml tomd. danM
                                             5-15%,
    MK.granaeang|n. UrttgnMnittaaierniii upwaroiand
      tan Hay caw
                          Undifleffniiatfd
                          Sand and
                                                Chalk and Umaaton*
OM* to rnadlum gray B wMft
orangt, or
                                                                          dark yctaMh orangt. v«y pal*
                                                                                 many toaaU da/m. srtBn
                                                and •oramMfcra. and aM HgtM
                                                and yvlOMMi gray
                                • lorn gray B medium gray
                                                                        and thai kigma
                                                                                   FIGURE   I- 3
                                                          Lindsay Site Stratigraphic Column
                                                                   Lindsay Manufacturing Site
                                                         	Dames  & Mocre

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Lindsay, Nebraska.  Ground water flow direction at the site is
complex because of the influence of several high capacity wells.

E.   Surface and Subsurface Features

     Currently, the facility contains five buildings including
the main manufacturing plant and offices, the maintenance
building, the galvanizing building, the final production building
and sludge presses.  Two settling ponds located on the north end
of the property are part of a wastewater treatment system.  The
treatment system also includes a neutralization tank, piping and
appurtenances.  This system serves as a wastewater treatment
facility to assist in interim remedial action.

     Interim remediation is provided by a ground water control
and recovery operation which includes two high capacity
interceptor wells, the Original Interceptor Well and the Add-on
Interceptor Well (OIW and AOIW), and above-ground pipelines
connecting the interceptor wells to the on-site wastewater
treatment facility.  The plant is supplied by the Lindsay public
water supply system and is serviced by the Lindsay public
sanitary sewer.  Storm drains at the plant discharge to the
intermittent drainage (Dry Creek) along the west property
boundary pursuant to NPDES permit No. NE0113905.


II. SITE HISTORY AND ENFORCEMENT ACTIVITIES

A.   site History

     The Lindsay Manufacturing Company site was originally
operated as a gasoline service station until the late 1950's.  In
1958,  Paul Zimmerer began a sprinkler manufacturing line.  In
1961,  a manufacturing plant was constructed on the site, and in
1965 a partnership was formed under the name of Lindsay
Manufacturing Co.  The "Zimmatic" center pivot system was
marketed in 1969 and the plant was expanded.  In 1970 the
operation was incorporated, followed by additional expansions in
plant and office space in 1971 and 1972.  The present galvanizing
building was constructed in 1972 and in 1973 a warehouse and gear
box manufacturing facility were  added to the sit*.  DeKalb
Agrasearch Inc. acquired Lindsay Manufacturing Co. in January
1974,  a business relationship that lasted until September 1988,
at which time Lindsay became a publicly-owned corporation.

     Disposal of materials from plant operations historically
included discharge of spent acid from the galvanizing building.
From the early 1970's to 1982, a spent acid stream was piped to
an earthen disposal pit ("pit") located north of the company's
galvanizing building.  In 1982 Lindsay Manufacturing company
replaced the pit with a new wastewater treatment facility
designed to neutralize the spent acid.  The pit was 50 feet in
width,  100 feet in length and approximately 8 to 10 feet deep.
The bottom and steep side slopes (1:1 or less) were apparently
unlined.  It had a capacity of 270,000 gallons, and typically

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 received  "slugs" of io,000 to 15,000 gallons approximately
 monthly.  The last slug of spent acid was received in December
 1982.  Since that time, only two discharges to the pit have
 occurred.  A one-time discharge of neutralized spent acid
 occurred  on January 28 to 31, 1983.  As Lindsay informed NDEC at
 the time, the discharge was necessary due to a leak detected in
 the acid  storage tanks.  The liquid was later pumped from the
 facility  and shipped to an off-site disposal facility.  On March
 29, 1983, approximately 107,000 gallons of ground water were
 pumped to the pit during a well test conducted for remedial
 action data collection. This liquid was also reclaimed by pumping
 from the  pit and shipped to an off-site disposal facility.

     Adjacent to the pit was a burn area used to dispose of
 cardboard boxes, pallets and paper.  This burn area replaced a
 previously used burn area which was located north of the plant in
 the area  of the drainage ditch.  Use of the older burn pit ended
when that area was paved in 1971.  Discussions with company
personnel have indicated the possibility that small quantities of
 solvents, degreasers and aerosol cans of degreasing compounds may
have been disposed of at the back door of the main plant.  Small
quantities of solvents and degreasers also may have been burned
 in both of the burn areas and disposed of in the pit along with
the spent acid.

     Lindsay Manufacturing Company had four wells and a deep test
hole drilled for a proposed wastewater treatment facility.  The
wells were installed in December 1982 and sampled in January
 1983.  The samples revealed that the ground water had abnormal
 acidity and temperatures.  At this time, Lindsay found that
disposal of spent acid from the galvanizing process was
contributing to ground water contamination.

     Three of the wells were found to contain water with low pH
and two of the wells had elevated water temperatures.  Lindsay
 reported  those findings to NDEC. As a result of this discovery,
 Lindsay Manufacturing Company began investigations of the soils
and ground water.

 B.   Interim Remedial Actions

     Lindsay Manufacturing Company and NDEC agreed that an
 interceptor well would be installed to intercept and remove
ground water for treatment.  An on-site interceptor  (original
 interceptor well - OIW) veil was installed by Lindsay in March
 1983 to intercept and recover acidic ground water from the
aquifer b«neath the site.  The OIW was located east of cells II
and 12 (see Figure 1-2).  The extracted ground water is
neutralized and treated in the wastewater treatment  facility,
which was constructed over the area of the former disposal pit.
The neutralization facility and cell fl were completed in May
 1983.  Cell 12 was completed in January 1984.  The filter presses
were installed in May 1984.  The interim pumping system began
operating in the spring of 1984.  Treated wastewater from the
treatment facility is handled according to NPDES Permit No.

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NE0113905.  A Stipulation  (Case No. 692) by NDEC and Lindsay
dated April 19, 1933 and amended August 10, 1983 and March 7,
1984 directed the subsequent site investigation and remediation.
Annual status reports were submitted to NDEC.

     By the end of 1988, the pump and treat interim action
resulted in the production of 550 million gallons (1680 acre ft)
of treated water, and approximately 7,500 tons of dewatered
sludge.  In early 1989, as a result of the recommendation in the
1988 Extended Subsurface Remedial Investigation, the Add-On
Interceptor Well (AOIW). was installed and connected by above-
ground pipeline to the vastevater treatment facility.  This AOIW
was designed to intercept and recover inorganic and organic
contaminants at the bottom of the aquifer which had been
identified in the 1988 study.  The AOIW is located at southeast
corner of the Lindsay Manufacturing Company property.

C.   NPL Site Listing

     On August 22,  1988 NDEC notified Lindsay Manufacturing
Company that it was the potentially responsible party (PRP)  for
the site as proposed (October 1984) and reproposed (June 1988)
for the Superfund National Priorities List (NPL).  Lindsay
Manufacturing Company was invited to participate in formal
negotiations to conduct a Remedial Investigation/Feasibility
Study (RI/FS)  for the site.

     The State of Nebraska, through a cooperative agreement with
the United states Environmental Protection Agency (EPA), was
authorized to enter into a Stipulation and Agreement with Lindsay
Manufacturing Company whereby Lindsay Manufacturing Company
agreed to conduct a Remedial Investigation/Feasibility Study
(RI/FS)  for the site.  The Stipulation and Agreement became
effective on January 5, 1989.  The site was subsequently added to
the NPL on October 4, 1989.

     A proposed RI Work Plan was prepared in accordance with the
agreement and submitted to NDEC in February 1989.  NDEC granted
partial approvals for the work plan on April 13, 1989, July  19,
1989, and August 7, 1989.  Final approval for the work plan was
granted on November 17, 1989.  Field work was initiated on or
about May of 1989 pursuant to approved portions of the work plan.

D.   Remedial Investigations

     In 1M3,  Lindsay Manufacturing initiated a hydrogeologic
investigation and remedial action which involved installation of
an interceptor veil to recover ground water.. During the
hydrogeologic investigation, 21 soil borings were completed and
sampled.   In 1987,  a shallow boring program consisting of fifteen
soil borings was conducted to reassess the quantity of acid
leachate contamination in site soils.

     In 1988,  an extended remedial subsurface investigation
initiated installation of 38 borings and five test holes to

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 characterize  the  nature  and extent of contamination in both
 ground water  and  soils.   In 1989, a Remedial Investigation was
 initiated which involved field sampling and testing of surface
 soils and sediments.  Ground water monitoring wells were
 installed to  collect ground water samples on-site and off-site.
 This new data was collected to supplement the data that had been
 collected in  the  previous investigations.


 III. HIGHLIGHTS OF COMMUNITY PARTICIPATION

     Community participation was provided in accordance with
 CERCLA, as amended by SARA and, to the extent practical, the
 National Contingency Plan.  Community participation highlights
 include the availability of several key documents in the
 administrative record, a public comment period and a public hearing.

     A community  relations plan for the site was completed by
NDEC and approved by EPA in June 1989.  This document lists
contacts and  interested  parties throughout government and the
local community.   It also establishes communication pathways to
ensure timely dissemination of pertinent information.

     The administrative  record for Lindsay Manufacturing Company
was released  in the draft form on November 7, 1989.  The record was
made available to the public at the following addresses:

     U.S. EPA, Region VII
     726 Minnesota Avenue
     Kansas City,  KS 913/551-7000

     Columbus Public Library
     2504 14th Street
     Columbus, NE 68601
     402/564-7116

     NDEC
     301 Centennial Mall  South
     Lincoln, NE   68509
     402/471-3388
       \
     A press  release was  issued on November 11, 1989 announcing
the availability  of the  record.  Key documents were added to the
record on February 20, March 28, June 25, July 6, July 9, July
16, and August 28, 1990.  Note that for the August 28, 1990
update, documents were added only to the EPA and NDEC
administrative records.

     The; Draft Remedial  Investigation (RI) Report was included in
the administrative record on March 28, 1990.  The Final RI and
draft Feasibility Study  (FS) Report were added to the record on
June 25,  1990.  The final FS was added to the NDEC and EPA record
on August 28, 1990.

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      The Proposed Plan for Lindsay Manufacturing  was  released  to
 the public on July ie, 1990 by placement  in  each  of the
 administrative records.   The notice of  availability for the
 Proposed Plan was published in the Columbus  Telegram  and the
 Omaha World Herald on July 10,  1990.  A public comment period  on
 the Proposed Plan was held from July 16 to August 15, 1990. At
 the request of Lindsay Manufacturing, the public  comment period
 was extended to August 31,  1990.

      A public notice appeared in the Columbus Telegram and the
 Omaha World Herald on July 10,  1990 announcing the Public
 Hearing.  In addition, a press release  was issued on  July  13,
 1990.  The Public Hearing was held August 9, 1990 at  the Town
 Hall in Lindsay, Nebraska to present the  Proposed Plan.  At this
 meeting, representatives from EPA and NDEC answered questions
 about problems at the site and the remedial  alternatives under
 consideration.

      All significant comments received  by NDEC prior  to the end
 of the comment period, including those  expressed  orally at the
 public meeting,  are addressed in the Responsiveness Summary,  in
 Section XI of this Record of Decision.

      This decision document presents the  selected remedy for
 Lindsay Manufacturing Company in Lindsay, Nebraska.   The decision
 for this site is based on the administrative record.
 IV.   SCOPE AND ROLE OF RESPONSE  ACTION  WITHIN  SITE  STRATEGY

 A.    Role  of Remedial  Action in  Site Clean Up  Strategy

      The remediation goal  for the  site  is to restore  the  aquifer
 to  acceptable water quality levels that are protective of human
 health and the environment.   The acceptable water quality levels
 that  have  been established under the Safe Drinking  Water  Act  are
 Maximum Contaminant Levels (MCLs)  or State of  Nebraska final
 ground water cleanup levels under  Title 118, Ground Water Quality
 Standards  and Use Classification.

      The enhanced existing ground  water extraction  and treatment
.system will restore ground water to acceptable water  quality
 levels as  shown in Table IV-1.

      The two existing  extraction and treatment walls  currently
 being optrattd to extract  ground water  are the Original
 Interceptor Wall "OIW" and the Add-on Interceptor Wall "AOIW".
 The AOIW is presently  designed to  pump  1,000 gpm.   The current
 pumping system would b« enhanced either by increasing the rate of
 the AOIW to 1,400 gpm  or by installing  a third extraction vail,
 identified as TIW,  to  supplement the present AOIW.

      The current treatment method  employs alkaline  precipitation
 of  zinc salts with the addition  of flocculating polymers  in a mix
 tank  followed by sedimentation of  the flocculent.   The dewatered

-------
 solid  residuals are disposed at a local landfill. Supernatant is
 recycled to the treataent system.

     Current data  indicates that the system removes approximately
 700 pounds/day of  zinc metal from the influent.  Because
 treatment takes place in open tanks, and because organic
 compounds in the ground water are readily stripped during
 agitation, the concentration of the organics are reduced during
 the treatment process.  The treated water is discharged to Dry
 Creek  under an NPDES permit issued by the State of Nebraska.

     If the pilot  study demonstrates that soil vapor extraction
 is practicable, the design of the system using actual data
 derived during the study will determine the actual number of
 extraction wells that would be required to effectively remove the
 organic compounds  from the soil.  Removing the contaminants from
 the soil would remove a source of organics that would have
 eventually entered the aquifer.  Using both treatment
 technologies, the  estimated time for ground water remediation is
 five years.

     If appropriate to protect human health, as part of the
 implementation of  this ROD, EPA and NDEC will evaluate options to
 ensure that drinking water wells are not installed in areas of
the contaminant plume on and off site.

B.   Scope of Problem Addressed

     The ground water was determined to be a principal threat in
the surrounding community for three reasons:

     1.   Ingestion of chlorinated organic compounds in drinking water;

     2.   Inhalation of volatilized chlorinated organic compounds
          during showering or bathing; and

     3.   Exposure by several pathways to inorganic contaminants
          (metals) , placing the potential chronic non-carcinogenic
          risk at  the present and future higher then the acceptable
          level (HI » 1.0).
         s
     Available data shows elevated concentrations ("hot spots")
of volatile organic compounds in on-site soils as being a
principal threat to ground water.
     In If §3, the Lindsay Manufacturing Company identified the
Old LindMy Public Supply Well to be a risk for ground water
contamination.  At that tine a new public water supply well was
installed upgradient of the site and is currently the sole source
of drinking water.

     The purpose of the selected remedy in this ROD is to prevent
current or future exposure to the contaminated ground water, to
determine the practicability of reducing contaminant migration
from the soil into the ground water, to implement soil vapor

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                            TABLE  17-1
               MAXIMUM GROUNDWATER CONTAMINATION AND
                 ESTABLISHED CLEANUP LEVELS (MCLS)

                         ORGANIC COMPOUNDS
COMPOUND
1 , 1-Dichloroethane
1,2-Dichloroethane
1 , l-Dichloroethene
1 , 2-Dichloroethene
(total)
Tetrachloroethene
1,1,1-
Trichloroethane
MAXIMUM
CONCENTRATION
SINCE 1987
(ug/1)
230
15
1600
29
1200
6500
MCLS
(ug/1)
NE
5
7
***
5*
200
                    INORGANIC COMPOUNDS  (»g/l)
COMPOUND
PH
Zinc
Sulfate
Cadmium
Chromium
L«ad
MAXIMUM
CONCENTRATION
SINCE 1986
(ng/D
2.8
1530
10,000
0.6
0.79
0.68
MCLS .
(mg/1)
6.5-8.5**
5**
250**
0.005*
0.05
0.05
MCL  -
NE
*    -
**   -
***
Maximum Contaminant Level  (Established cl«an-up level]
Not established
Proposed MCL
Secondary MCL
Proposed MCL for cis -  1,2-dichloroethene is 70 ug/1
Proposed MCL for trans  - l.2-dichloroethane is 100 ug.
*rc«\lindi*y.906

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extraction  if practicable, and to restore the ground water
aquifer to  MCL quality.


V.   SUMMARY OF SITE CHARACTERISTICS

     The spent acid disposal pit has been identified as a source
of both inorganic and organic contamination of the aquifer at the
site.  Spent acid was piped into the earthen pit from the early
1970s to 1982.  Grease, oil, and 1,1,1-trichloroethane (TCA)  were
also disposed of and burned in the burn pit located adjacent to
the spent acid disposal pit as well as in the disposal pit
itself.

     In addition to disposal of solvents and degreasers in the
spent acid disposal pit and burn pit, solvents and degreasers are
also reported to have been disposed of at the rear of the site
and at the main plant prior to paving.  Lindsay investigated
areas of potential soil contamination in 1988, prior to the
Remedial Investigation (RI).

A.   Soils

     A more detailed summary of the affected soil and ground
water at the site is presented below in sections A and B.

     The nature and extent of the presence of contaminants in
soil at the site is based on analytical results of subsurface
soil samples collected between June and August 1988.  The soils
with elevated volatile organic contaminants (VOC) that may be
contributing to the ground water contamination are located in the
central drainage ditch, near the northeast corner of the main
plant building, and in the central northern portion of the site.
Laboratory results show that the highest concentrations of VOCs
are at depths of approximately 22 to 40 feet.  During the 1988
investigation, Lindsay identified a buried sand channel which
trends N-NW to S-SE through the site and was mapped for over 1100
feet.  The sand channel was found to extend at least 300 feet
laterally north of the northern Lindsay property line.  The sand
channel was determined to reach a maximum thickness of 25 to 30
feet near the south east corner of cell 12 of the wastewater
treatment facility.  The maximum width is 150 feet near the
center part of cell 12.  The depth of the sand channel ranges
from approximately 15 to 45 feet.

Inorganic Soil Contaminants

     Sixteen subsurface soil samples from the area in the sand
channel were analyzed by EPA methods for total arsenic, cadmium,
barium, chromium, lead, mercury, selenium, silver, iron, and
zinc.  Metal concentrations reported above the detection limit
are summarized in Table V-l.  A concentration range for elemental
naturally occurring concentrations in soils, i.e. background, is
also provided in Table V-l for comparative purposes.  Metal
results from the soil samples listed in Table V-l are all within

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their respective naturally occurring concentration ranges.

     Five subsurface soil samples were analyzed for EP toxicity
metal analysis.  Table V-l lists EP toxicity results and EP
toxicity limits.  All results from the soil samples were below EP
toxicity limits.

     Upon discontinuance of the use of the acid disposal pit,  the
source of metal contamination to site soils ended.

Organic Soil Contaminants

     Subsurface soil samples collected in 1988 were analyzed for
volatile organic compounds using a combination of soil gas field
screening and laboratory analysis of soils.  The results have
been used to determine the occurrence and trends of organic
compounds.

     The purpose of field screening was to provide immediate
results to qualitatively determine if select organic chemicals
were present and to evaluate data trends.  The purpose of the
laboratory analysis was to confirm field screening results and
provide additional data.  The laboratory sample detection limit
for all compounds in soil was 0.3 mg/kg as specified in the EPA
method.  The field screening detection limit was about 5 ug/1
(air).   Soil sample laboratory results are listed in Table V-2.

     Tetrachloroethylene (PCE) was the most frequent of the
organic compound* found in subsurface soils (Figure V-l).  PCE
was detected in silty clay material in the area of the central
drainage ditch throughout the soil column (from approximately 3
feet to 48 feet below surface grade), and generally was found at
higher levels between 33 feet and 48 feet.  PCE levels were
higher at the center of the site,  with the highest PCE
concentration at 6.8 ng/kg.

     PCE was also detected by field screening throughout the soil
column near the northeast corner of the main plant building, from
approximately 3 feet to 43 feet below surface grade.
        \
     PCE was found above, within, below, and in the vicinity of
the sand channel.  PCE levels decreased in concentration to the
north.

     Th» approximate horizontal extent of 1,1,1-trichloroethane
(TCA) was not found in as vide an area as PCE  (Figure V-2).  TCA
was found at levels higher than other organic compounds found on
site.  TCA was found in the following areas on site: near the
central drainage ditch; the northeast corner of the Bain plant
building; and north of Call 12 of the wastewater treatment
facility.  The highest TCA concentration was 14.1 ag/kg naar the
northeast corner of the vain building.

     TCA occurrence and trends in subsurface soils are similar to
the PCE trends.  TCA was found in silty clays  in the central
                                 10

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 drainage  area  primarily between 18 feet and 43 feet below surface
 grade.  The  TCA field  screening maxima was found near the
 northeast corner of  the main plant building,  it was detected
 from approximately 8 feet to 42 feet below surface grade.  TCA
 also was  detected in the area north of Cell 12 of the wastewater
 treatment facility.

      The  extent of 1,1-dichloroethene (DCE) (Figure V-3) was
 found over a broad area and, like PCE and TCA, was centered
 around the central drainage ditch and the northeast corner of the
 main plant building.   DCE was also found north of the central
 drainage  area  near Cell 12 of the wastewater treatment facility
 where PCE and  TCA were found.  The highest DCE concentration on-
 site was  1.9 mg/kg near the northeast corner of the main plant
 building.

     PCE and  DCE occur  most widely at the site.  TCA is more
 limited in extent but  appears at the highest individual
 concentration  of the organic compounds.  PCE, DCE and TCA areas
 of contamination are shown in Figure V-4.

 B.    Ground  Water

      The discussion  of the nature and extent of inorganic and
 organic ground  water contamination is based on ground water
monitoring data collected from 1983 through January 1990.  Ground
water quality has improved in some areas during this tine due to
the  interim  remedial measures discussed in Section II B.  The
 remaining  organic and  inorganic contamination has been defined by
the  1989/1990 RI.  Inorganic and organic contaminants in the
aquifer occur  from near Monitoring Well 87-6 southeast to
 irrigation well  154278 as shown in Figure V-5.  The occurrence is
along the  bottom of  the aquifer except for the area beneath the
old  spent  acid  pit and the northeast corner of the main plant
building.

Sand  Channel

      A buried sand channel was identified by Lindsay in the RI.
Two monitoring  veils, MW89-13 and MW89-14, are screened in the
sand  channel only.   Samples from these wells were analyzed for a
range of inorganic and organic constituents.  Detectable levels
of zinc,  iron,  sulfates and organics were found in the ground
water.

      Zinc, iron,  and sulfate levels were above the secondary
drinking water  regulations for these elements in all samples.
These secondary standards were developed to protect the public
welfare by preserving the quality of the ground water as e
drinking water  source based on odor, aesthetics and appearance.
Nebraska and EPA secondary standards for zinc, iron end sulfate
are 5, 0.3, and  250 ag/1, respectively.

      Levels of  DCE and TCA in some ground water samples froa the
sand channel were found to exceed Nebraska or EPA Maximum
                                 11

-------
 Contaminant Levels  (MCLs)•  MCLs have been developed as public
 health standards for drinking water.  The Nebraska and EPA MCLs
 for  DCE and TCA are 0.007 and 0.20 mg/1 respectively.  The DCE
 MCL  was exceeded in MW89-13 and MW89-14.  The TCA MCL was
 exceeded  in MW89-14.

     There is currently no Nebraska or EPA MCL established for
 PCE.  EPA has proposed an MCL for PCE of 0.005 mg/1 but has not
 promulgated MCL regulations.  PCE concentrations in MW89-13 and
 MW89-14 were 0.19 and 0.015 mg/1 respectively.

 Aquifer

     As discussed above, some aquifer monitoring wells were
 completed in the upper portion only, some in the lower portion
 only, and some were screened throughout the aquifer.  Samples
 collected from these wells were analyzed for a variety of
 inorganic and organic constituents.  Detectable levels of zinc,
 iron, sulfates and some organics were observed in both the upper
 and  lower sections of the aquifer.  The generalized area of
 ground water contamination is presented in Figure V-5.

     Zinc has occurred above the secondary drinking water
 regulation of 5 mg/1 in the upper and lower portions of the
 aquifer.  Only a small area of occurrence is indicated in the
 upper aquifer compared to that found in the lower aquifer. As a
 result of the density of zinc, concentrations in the lower
 aquifer are generally higher than in the upper and entire aquifer
 samples.

     Sulfate has occurred above the secondary drinking water
 regulation of 250 ppm in aquifer.  Only a small area of
 occurrence is indicated in the upper aquifer compared to that
 found in the lower aquifer.  As a result of the density of
 sulfates, concentrations in the lower aquifer are generally
 higher than in the upper aquifer samples.

     Iron concentrations have occurred above the secondary
 drinking water regulation of 0.3 ppm in both the upper aquifer
 and the .lover aquifer. As with the zinc and sulfate, the extent
 of iron occurrence in the lower portion of the aquifer is greater
 than in the upper portion.

     Cadmium and lead occur sporadically and only in some wells.
 Cadmium was found above the MCL of 0.01 mg/1 only in TMW 88-5,
 TMW 88-6, and TMW 88-9 more than once.  These three veils are at
 the bottom of the aquifer near the AOIW where their transport is
 controlled by interim remediation.  All other occurrences are
 either a single detection or short term followed by non-
detection.  Lead was found above the MCL of 0.05 mg/1 once in
well P-6 and repeatedly at diminishing concentrations to below
the MCL in P-9.  Both wells are at the bottom of the aquifer and
close to interceptor wells which control the lead transport and
 recovery by remedial pumping.
                                 12

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 TABLE  V-1
 Summary of Laboratory Soil Sample Results
 Total Metal and EPToxIcity Metal

 Total Metal (mg/kg)
§1 M •!•• *•
uonnQ

SB-3

SB-5


SB-6

SB-13

SB-14
SB-32

SB-35
SB-36
SB-37

Depth
(to*))
37
41
27
32
43
37
44
33
38
38
33
43
43
33
33
38
• M aalajl 'Vial
Concentration Ranoa (1)
fatal
AiMafe
1J3
0.96
NO
0.44
029
6.09
0.69
0.79
0.31
11.10
12.30
9.92
2.70
0.90
030
0.19
Wl ^
97
Total
BartuM
216
159
131
116
173
220
745
233
218
294
258
236
220
259
193
see
W.
50.000
Total
Chromium
926
14.6
9.54
11.9
20.4
15.3
9.19
203
15.9
16.6
17.9
18.0
149
20.1
18.1
4.19

1.
•
2.000
Total
toon
10.146
13.073
10.047
10.766
15.005
16.394
10^38
21.534
19.779
19.995
21.215
19.148
16.450
21.591
15.709
4.118
inn.
•w
>100.000
Total
Zinc
596
832
168
274
1.633
51.5
190
1.071
1.059
68.1
63.6
48.7
453
523
26.7
2.79
g-
29.000
EP Toxlclty Metal (mg/l)
                                                                     (1) USQS. Elemental Concentrations in
                                                                        Sob and Other Surfical Materials Of
                                                                        me Conterminous United Slates 1984.
                                                                    NO- Not Defected
§1 a,-aW •
Donng
SB-2
SB-*
S85
SB-6
EPToKicily
Limits
(feel)
38.5
40
43
44.5

A-**
0.002
NO
NO
NO
50
**"
0.1
NO
NO
NO
100
Ghroariua.
NO
NO
NO
NO
5.0
Uad
NO
NO
NO
NO
5.0
Mercury
0.2
NO
NO
NO
0.2
SOMffMffli
NO
NO
NO
NO
1.0
SMwer
NO
0.14
NO
021
5.0
Cadmium

NO
NO
NO
NO
1.0
Job number 16657-002-005
Dames & Moore

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   TABLE V-2
   Summary of Laboratory Soil Sample Results
   Organic* Compounds (mg/kg)
ATM el
SHt
Central
Drainage
Otteft
Northaaat
Corner of
Main Plant
Coll«2
Boring
SB-23
SB-22
SB-24
SB-27
SB-2S
SB-32
SB-11
SB-33
SB- 12
SB-16
SB-3
SB-4
S8-14
Depth
Jleet)
I^HMMIM^^M^M^^MMi
18
38
28
43
33
38
38
38
48
38
48
8
22
32
40
44
23
33
20
3
43
45
42
43
46
PCS
••••••MMpiB^BB^BBMPHHM
1.2
NO
2.7
2.4
3.1
6.8
0.3
0.4
0.4
NO
NO-
NO
NO
1.7
0.4
NO
NO
1.6
NO
NO
0.6
NO
1.2
0.4
NO
TCA
1.0
0.3
2.1
1.2
U
1.1
NO
0.7
0.6
1.1
0.7
0.5
6.4
14.1
2.7
0.4
0.5
7.4
3.4
0.73
1.2
0.7
NO
1.5
1.0
OCE
^^^^^•^^•••^•^••••MBI
0.3
NO
NO
NO
NO
NO
NO
NO
NO
0.4
NO
NO
0.7
1.9
0.6
NO
NO
1.5
0.8
NO
0.5
NO
NO
0.3
NO
         NOU»:

          NO- NMDftMStd
Job numb«r 16657-002-005
Dames & Moore

-------
             ClisIM* PloduclkM We«i

             t il<1U( Pi€


             f acMty MoAirwIog MMIf !»•/


             Slu*N> Augei Bofingi !»••
                Occwmc*
                                     ol
                                       FIGURE V- 1
 Approximate Horizontal Boundary of PCEOccurrence
                                  June-August 1988
                          Lindsay Manufacturing Site
	Dames & Moore

-------
ea^
— "3CL
%'V
t-M*J IC**V
;
-*-l4»-
~^l|
1 '
I !
fT
                IV\fl—I—I

                V *c M If *t
             I «i»lmg Pf

             f -
                             IM7
            I»»l Hot** t *M


            ApfxoilriuM HwllOfllcl Bound*! , I
            f C A Occvranc*
                                      FIGURE V  .
Approximate Horizontal Boundary ol TCAOccurrence
                                •Mine-August 1988
                        Lindsay Manufacturing Site
           	. Dames A Moore

-------
             Eiltling PioducIlM WHIt
                 r MoflllMhig We*» IM7

            SlMlov Augw Bwingt I9M

            hit Mo*.. >•>«•

            Appio.lm.l. Hoclionl*! Bou»<«»y ,
            DCC OCCOICHC*
                                     FIGURE  V -
Approximate Horizontal Boundary of DCEOccurrenc.
                                  June-August I98b
                         Lindsay Manufacturing Site
                           	Dames A Moor*

-------
AppfoihMI* BoundMy el
OCC Occuf
Appioilmat* Boundwy ol
TCA OccutfMtc*
                         FIGURE  V-4
       Approximate Horizontal Boundary,
       ol PCE, TCA and OCEOccurrence
                     June-August 198
             Lindsay Manufacturing Sn
                      Dames A Moor.

-------
•  Fitting r..






   I .C*.!, Mo^KMMg *.I. IMI






O  1«mpe
-------
     Available data shows elevated concentrations ("hot spot") of
volatile organic compounds  (VOCs) in on-site soils as being a
principal threat to ground water.  Ground water data from MW89-
12,  located near a VOC hot spot area northeast of the main plant
building, from November 1989 to May 1990 has shown increasing
concentrations of l,i-DCA from 49 ug/1 to 520 ug/1.   TCA and PCE
have also shown high concentrations.  The data shows that this
hot  spot area is a principal threat contributing to the ground
water VOC contamination.

     NDEC has assigned the aquifer at the site to Remedial Action
Class One (RAC-1) pursuant to Title 118 - Ground Water Quality
and Use Classification.  RAC-1 aquifers receive the most
extensive remedial action measures.  This relates to the SOWA
Class I and Class II aquifers which are characterized as
irreplaceable, current or potential drinking water sources.

C.   Contaminant Fate and Transport

     According to the RI, the fate of the acidic metal-laden
water (with its dissolved organic components) has been subject to
several dynamic conditions. These conditions include density
differences between the acidic metal laden waters and aquifer
waters, chemical gradients, variable hydraulic gradients
resulting from high capacity well operations and the influences
of dilution and neutralization.  Forces that are of little or no
influence in the aquifer are solute chemical reaction and
adsorption-desorption.  These forces are generally weak because
of the relatively inert nature of the aquifer matrix.  Because of
the relatively low reactive potential of the chemical compounds
within the aquifer, the compounds are transported by and can be
intercepted or recovered in the ground water.  This fluid
transport, the gradual dispersion and the recovery of the
chemical compounds have been traced through time in the
monitoring well water samples results.


VI.SUMMARY OF SITE RISKS

A.   Human Health Risks
      X
     The baseline risk assessment addresses potential human
health and ecological risk associated with currently existing
(i.e. baseline)  as veil as potential future conditions at the
site. The) baseline risk assessment consists of the following
steps: hazard identification, exposure assessment, toxicity
assessment and risk characterization.

     Hazard identification involves gathering and analyzing the
site data relevant to the human health evaluation and identifying
the substances present at the site that are the focus of the risk
assessment process.

     Exposure assessment is conducted to estimate the magnitude
of actual and/or potential human exposures, the frequency  and


                                 13

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 duration of these exposures, and the pathways by which humans are
 potentially exposed.
     The toxicity assessment component of the risk assessment is
 accomplished  in two steps.  Hazard identification is the first
 step in the process; it will determine whether exposure to an
 agent can cause an increase in the incidence of an adverse health
 effect  (e.g.  cancer, birth defects....) and also involves
 characterizing the nature and strength of the evidence of
 causation.  In the second step, dose-response evaluation,
 toxicity information is quantitatively evaluated and the
 relationship  between the dose of the contaminant received and the
 incidence of  adverse health effects in the exposed population is
 characterized.  From this quantitative dose-response
 relationship, toxicity values are derived that can be used to
 estimate the  incidence of adverse effects occurring in humans at
 different exposure levels.

     The final step of the baseline risk assessment process is
 risk characterization.  Risk characterization summarizes and
 combines outputs of the exposure and toxicity assessments to
 characterize  baseline risk, both in quantitative expressions and
 qualitative statements.

 Hazard Identification

     Groundwater data used for evaluation of potential exposure
 pathways to off-site human receptors is based on the 1989
 sampling results froa both on-site and off-site monitoring and
 drinking water wells and soil concentrations obtained in 1989.

     The contaminants used in the risk assessment are listed in
 Table VI-l for ground water and Table VI-2 for soils and grass.

 Exposure Assessment

     The baseline risk assessment of the Lindsay NPL site is
 based on 1989 data from on-site and off-site ground water, on-
 site and off-site soils and sediment for drainage pathways, and
 modeled,airborne particulate concentrations.

     A fundamental component of the baseline risk assessment is
 the exposure  assessment, which estimates the potential human
 exposure to chemical compounds that are present at or have
migrated ftom the site.  Exposure assessment consists of
 characterisation of the local setting, identification of
 potential exposure pathways, and quantification of potential
 exposure expressed in toxicological terms as dose per unit time.

     The characterization of the local potential exposure setting
 is based on site information used in part to identify the
 potentially exposed population.  The subsequent identification of
 potential exposure pathways describes in qualitative terms the
 course a target chemical could, under the Reasonable Maximum
 Exposure (RME) scenario, take from the site to potential receptcr


                                 14

-------
 populations.  The  intent of the RME scenario is to estimate a
 conservative exposure case that is within the range of possible
 exposure under current and future land use conditions.

     The closest residential community to the Lindsay site is the
 village of Lindsay, located immediately to the west.  To the east
 and south of the facility are a number of large farms.  Both
 existing and projected land use within the immediate area is
 rural and agricultural, with predominantly single-family
 residences.

     Based on the  fact that the current water supply for both the
 site and village of Lindsay is located hydraulically upgradient
 of the facility, the village of Lindsay was not included in the
 exposure assessment.  The prevailing ground water flow is toward
 the area southeast of the site.  The rural population on the land
 southeast of the site thus constitutes the primary potential
 receptor population.  Because no hospitals, day-care centers, or
 other potentially sensitive land use activities are located in
 the path of ground water flow from the site, it was not necessary
 to assume that any unusually sensitive receptor populations
 occupied this off-site area.

     Since contaminants have been detected above MCLs in
 irrigation well 154278 located southeast of the site, EPA and
NDEC will evaluate options to ensure that drinking water wells
 are not installed in areas of the contaminant plume on and off
 site as part of the implementation of the ROD if necessary to
protect public health.

     The land us* surrounding the site consists largely of
 farming operations, although there is limited habitat for a
variety of wildlife.  The potential for effects on wildlife is
 further discussed in Section VI-B.  In the future scenario,
potential receptor populations include: the present population at
 risk,  the population of Lindsay, and on-site workers.  For the
 off-site rural population adjacent to the site, all age groups
may potentially be exposed to compounds released from the site,
 and their exposure represents a composite release from the site.

     Six exposure pathways were evaluated in the risk assessment.
These pathways arc potential exposure via soil ingestion, dermal
contact with soil, drinking water ingestion, inhalation of vapors
 from water*, ingestion of homegrown fruits and vegetable*, and
 inhalation of wind-driven particulate dust from off-sit*.

Calculation of Dose:

     The general considerations used in conducting the exposure
assessment involve the chemical dose (concentration per unit
time),  the exposure duration and frequency, the rat* of contact,
and other specific parameters.

     For each contaminant of concern a chemical intake or dose
was calculated for each route of exposure.


                                 15

-------
     For the ingestion of chemicals in drinking water the
 following equation was used:

        Intake  (mg/kg/day) = CW x IR x EF x ED
                                   BW x AT
        where,

        CW: chemical concentration in water (mg/liter)
        IR: ingestion rate (liters/day)
        EF: exposure frequency (days/year)
        ED: exposure duration (years)
        BW: body weight (kg)
        AT: averaging time; period over which exposure is averaged
            (days)

     For an adult a body weight of 70 kg was used to represent an
average adult. An ingestion rate of 2 liters of water per day was
assumed. The exposure frequency of 365 days per year was used to
represent lifetime exposure.  For concentrations in drinking
water the upper 95th percentile of the averaged concentrations
was used to represent a Reasonable Maximum Exposure (RME).

     Other intake equations are outlined in the Remedial
Investigation in Section 6.0.  See Table VI-3 for a summary of
potential dose or intake to off-site receptors.

Toxicity Assessment

     Under current EPA guidelines the likelihood of carcinogenic
and non-carcinogenic effects due to exposure to site chemicals
are considered separately.  Criteria for evaluating the potential
of site chemicals to cause these two types of adverse effects are
described below.

     Carcinogenic and non-carcinogenic risks posed by
contaminants were evaluated for the potentially exposed
population with regard to each exposure pathway for current and
projected uses of the site and its surroundings.

Criteria .for Non-carcinogenic Effects
      \
     A reference dose (RfD) is the toxicity value used most often
in evaluating non-carcinogenic effects resulting from exposures
from the sit*.  Additionally, one-day or ten-day Health
Advisories (HAs) nay be used to evaluate short-term oral
exposures.

     Various types of RfDs are available depending on the
exposure rout* (oral, inhalation, dermal), the critical effect
(developmental or other) and the length of exposure being
evaluated (chronic, subchronic or single event).  A chronic RfD
is an estimate of a daily exposure level for the human
population, including sensitive populations, that is likely to be-
without an appreciable risk of deleterious effects during a
lifetime.  Chronic RfDs are developed to be protective for long-


                                 16

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term exposure to a compound.  Chronic RfDs are generally used to
evaluate the potential non-carcinogenic effects associated with
exposure periods between 7 years and lifetime.  Subchronic RfDs
are generally used for exposure periods between 2 weeks and 7
years.  Developmental RfDs are used to evaluate the potential
effects on a developing organism following a single exposure
event. A summary of the Chronic RfDs used in the risk assessment
are presented in Table Vl-4.

     For non-carcinogens, the projected dose or intake developed
in the exposure assessment is divided by the RfD value to compute
the Hazard Index (HI).  This approach reflects the assumption
that a toxicity threshold generally exists for non-carcinogens,
and that the risk can be represented by the quotient of the dose
and the allowable RfD.  The HI was developed by EPA to assess the
overall potential for non-carcinogenic effects posed by multiple
chemical exposures although each individual toxicant is evaluated
individually.   The HI is not designed as a mathematical
prediction of the severity of the non-carcinogenic effects,
rather it is an indication of potential adverse effects in view
of established RfD criteria for specific chemical compounds.
The potential chronic non-carcinogenic risk at the present and in
the future is higher than the acceptable level (HI - 1.0) for
several exposure pathways.

     The values ranged from less than 1 to 95.  The inorganic
contaminants of concern are cadmium, lead and zinc.  See Table
Vl-5 for the hazard index calculation results.

Criteria for Carcinogenic Effects

     The EPA uses a weight-of-evidence system to convey how
likely a chemical is to be a human carcinogen, based on
epidemiological studies, animal studies, and other supportive
data.  The classification system for characterization of the
overall weight of evidence for carcinogenicity includes:  Group
A: Human Carcinogen; Group B: Probable Human Carcinogen; Group C:
Possible Human Carcinogen; Group D: Not Classifiable as to Human
Carcinogenicity; and Group E: Evidence of Non-Carcinogenicity for
Humans. . Group B is subdivided into two groups:  Group Bl:
limited human evidence for carcinogenicity and Group B2:
sufficient data in animals but inadequate or no evidence in.
humans.  See Table VT-6 for the classifications of the chemicals
of concern.

     For chemicals with carcinogenic effects, EPA calculates the
cancer riek associated with a given doee by multiplying the dose
from a given route of exposure by a cancer slope factor.  Slope
factors are derived from the upper 95% confidence limit of the
slope of the extrapolated dose-response curve, which shows the
relationship between a given dose and the associated tumor
incidence.  This conservative model assumes no toxicity threshold
and unlike the non-carcinogens evaluated using the Hazard Index
(HI), these risks are assumed to be additive  in nature  (i.e.,
cancer is assumed to be systemic rather than  target organ-


                                 17

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 specific).  Slope factors used in the risk assessment are listed
 in Table VI-6.

     A cancer risk is expressed as the likelihood for an
 individual to contract cancer over a lifetime as a result of
 exposure to a specific chemical compound.  The cancer risk for
 each compound is added together to produce the total risk from
 exposure to multiple compounds.

 Risk Characterization.

     The general target for lifetime cancer risk under the
 Reasonable Maximum Exposure (RME) scenario is between 1 x 10*4
 and 1 xlO-6, or l.in 10,000 to 1,000,000  This was determined to
 be the most appropriate target for the purposes of the Lindsay RI
 and the FS.

     Under current and future conditions nearly all the potential
 cumulative excess cancer (1.6 x 10-2) is due to the exposure to
 chlorinated organic compounds based on ingestion of drinking
 water and inhalation of volatilized chlorinated organic*
 compounds during showering or bathing.  The organic contaminants
 of concern are 1,1-dichloroethane, 1,2-dichloroethane, 1,1-
 dichloroethylene, tetrachloroethylene, and trichloroethylene that
 are possible human carcinogens.  Cadmium was the only metal
 characterized as a possible human carcinogen. None of the other
 metals are deemed to be possible carcinogens and therefore they
 were not included. See Table VI-7 for a summary of potential
 cancer risks to off-site receptors.

     The National Oil and Hazardous Substances Pollution
 Contingency Plan (NCP) advises an acceptable excess cancer risk
 is in the range of 1 x 10-4 to 1 x 10-6, depending upon
 individual site conditions.  This means the excess risk for a
 person to contract cancer is between 1 in 10,000 and 1 in
 1,000,000.  Remediation attempts to reach a 1 in 1,000,000 risk
 level where possible. The remedial goal for ground water will be
 the Maximum Contaminant Level (MCL) or established clean up level
 for each contaminant.
          •s

     Actual or threatened releases of hazardous substances at or
 from this site, if not addressed by implementing the response
 action selected in this Record of Decision, may present an
 imminent and substantial endangerment to the public health,
welfare, or the environment.

 B.   Environmental Risks

     The potential that on-site soils would pose a threat to
wildlife coming on to the site was evaluated.  The compound most
 likely to impact wildlife is believed to be zinc.  It is assumed
that the primary means by which the compounds are brought to the
 surface off-site is through pumping of irrigation wells.  Organic
 solvents present in the ground water are generally volatile and
 are expected to dissipate quickly into the atmosphere when


                                 18

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Table  vi-i
Summary of 1989 Groundwater Data Used for Baseline Assessment
Lindsay Mfg. Co.
I 1
n Compound

Cadmfcjm
Ctvomhjm
Lead
r«
Traoe Organic*
.1«*cNofoe*ane
.2-dkttONMtftana
.1-dMauiuamylant
,2-o%t»oroethylene
. 1.1 -tricMoroetfian*
TeliatMmuNhylano
Tlt*too-*l~

Fraojueiicyof
Oatadloji
32f160
13/159
77/160
150/161

35^73
9/173
69/173
11/173
82/173
71/173
9/173

Average

844
8.88
20.23
44.734.47

5.31
3.46
28.65
4.04
107.94
3209
280
Ground
Standard
Deviation
25.15
29.97
127.99
115.920.36

9.08
2.81
67.84
3.48
395.50
68.44
1.57
Water Concentratl
Upper 95lh
percent He
4982
56.18
230.78
235.423.49

20.24
809
140.28
9.77
758.54
144.67
5.39
on ftifll)
Maximum

180
277
1.600
532.000

72
25
510
25
2.900
430
5

Sample
Size
160
159
160
161

173
173
173
173
173
173
173
         oo?oos
                                                                            Dames & Moore

-------
Table  vi-2
Summary of Off-Site Soil and Grass Metals Concentrations
Lindsay Mfg. Co.


Compound
SOUS
Cednfcm
jiefeiMice MM)
lead
[reference MM)
Zinc
[reference eraa)
GRASS
Cadmium
(reference MM)
lead
(roterenoe MM)
Zinc
[reference MM)
^QQIIOlHLiBBBpHi

AMMi

NO
NO
NO
NO
57.2S
49

NO
NO
NO
NO
IS
53
»,



a)
(b)
•)
(b)



(b)
(b)
(b)
(b)


moftQdrywt
'
MnkMMi

NO
NO
11
NO
61
~

NO
NO
NO
NO
65
53




(•)
(b)

(b)



(b)
(b)
(b)
(b)



Sample sin
(n)

4
1
4
1
4
1








Detection
Urn*

10
1.0
10.0
10.0
1.0
1.0

1.0
1.0
10.0
10.0
1.0
1.0
NOTES:
<•» Not drtwfed. but tfc •» Mmpto quanttaion ftrt was Inowporaled into the quanllalivaanaVsb.
(b) Not detertirt «l tie InJceled toxul.
NO --- fat Detected
   to 16657^02^05
Dames A MOOTQ

-------
 Table  vi-3
 Summary of Potential Total Exposure (I.e., dose) to Off-Site Receptors By Age Class
 Lindsay Mfg. Co.
                                                                    AGE 8 lo It
                                                        ORAL (rrayfcg day)
                                                        Average |  RME
                                                     INHAL (moAg<
-------
Table   VI-A
Summary of Non-cardnogtnlc Chronic RID Values (a)
Lindsay Mfg. Site
mACt METALS
                          •.MM
                            •.a
                                      ft
                                      ft
                                      ft
                               dMTral
                                                UF.IOtor
                                                 MF-I
                                               UF.IOOto
                                                 MF-H)
                                               UF. 900 tar
                                                 MF-I
           H

           H.A

           H.AS
1MACC
17

I.I


1.2


I.I.I


f*
                            •.I
•M
M

ft

A

ft

ft
 UF.IOOO

 UF.IOOO

UF.IOOO tar
  MF-I

UF.IOOO tar
  MF-I

UF-1000 tar
  MF-I

UF.IOOO tar
  MF.t
                                                                    HAS


                                                                    HAS


                                                                    HAL
    to \btAlOOJOM

-------
Table-vi-4  (continued)
Summary of Non-cardnogtnlc Chronic RID Values (a)
Lindsay Mfg. Silo
pkoJrilbilVM.UBfc
                                                  ConM*nc*
                                                                             CiMcri
                                                                             Eltert
                                                                                        (UF/MFltel
IVIACCMCfAIA

                             ••Ml

                             eoaoa
                              ••t
                                            w
                                            M

                              01
                              ••*
                              0.11
                                                                                         UF.IOOO
                                                                                         UF-IOOO
                                                                                        UF.IOOOto
                                                                                          fcF-l
H.A.S
                              *• BMIW WMk OMH>|ErA.ltMk); MpvM M
                                                                                               IMM not tmn
                                  *OM IOAEL to NOAEL S - •ikapotafcM kom tubchtonlc to dwonfc NOAEL;
                                                            IMflb).
 lab Nil I66S20O20M

-------
Table  "i-s
Summary of Potential Hazard Characterization for Non-Carcinogenic Compounds
RME Scenario. Off-Site ITMiptnri
Lindsay Mfg. Co.
„„,,.„.,«,
TRACE METALS
Cadmium
ClwonNuni
L«ad
Zinc
TRACE OROAMCS
ft « »^« 	 ^** — — —
, i "UitniuiO6>ian>
1.24tal*>roettiafw
«« ^AlMA^^^fk^dAM^^a^A
, l -OlCraONManpanB
1,2
-------
Table  vi-6
Summary of Carcinogenic Slope Factors
Lindsay Mfg. Site


COMPOUND
TRACE METALS
Cumum (and Compound*)
Cftromun HI (and Cempeundi)
Ovomfn VI (and Compouna)
Laari (inorganic and Compouid*)
23ne (and CameonOB)
THACt OMOAMICS
1.1.0*MOnM«MM
U.0kmt«n.
> 1 1 *OI^N0^0fl^^n0O9
l,i,i-ticr)toroiWiin«
T M ^ia ^^i^k*^
Twaoniofoaciytana

ORAL SLOPE
'ACTON (•)
(maliQ-terVi

NO (0
NO (C)
NO (C)
NO (C)
NO (0

OM\
0.001
O.I
/. A
I*. I)
(C)

0.011
W*ioni
-------
 Table  vi-6    (continued)
 Summary of Carcinogenic Slop* Factors
 Lindsay Mfg. Site
MMALATON Wrtgnt-
•LC*I PACTON (a) CtoM*
COMPOUND (moAoHtovVi On»i
THaCE U£T*i_S
CMrrvum (and fnwuuuna) ^ ,
CtvemUn III (and CampujHE) NO
Chjomfam VI (and Compound*) 41
Laad (taoroanc and Compound*) NO
Zne (and Compound*) NO
onailai»ia» tar ajianrmiNt m» i
                                                                          luamga
     I No 16ft57-00240S

-------
brought to the surface in irrigation water,  it is expected that
dilution and dispersion of this organic compound will reduce
their concentration below potential significant exposure levels.
There is a wide variety of animals that could live in and around
the fields impacted by irrigation well 154278 located southeast
of the Lindsay facility.  Few species would find all of their
habitat requirements met entirely within the fields, because
crops and field borders would probably only be used for a portion
of their lifetime and of their home range.

     The amount of exposure will vary depending on the habits of
an individual species.  Species that live primarily within the
field are most susceptible to exposure, while those that live on
the field borders or only occasionally use the areas would be
less susceptible.  The ecological assessment, based on on-site
surface soil and irrigation ground water indicated no significant
potential exposure of wildlife inhabiting the vicinity of Lindsay
to site-related chemical compounds.
VII. DESCRIPTION OF ALTERNATIVES

     The alternatives analyzed for the Lindsay Manufacturing
Company site are presented below.  These are numbered to
correspond with the numbers in the FS report.
          Alternative 1:

          Alternative 2:
          Alternative 3:
          Alternative 4:
     *    Alternative 4A:
          Alternative 5:
          Alternative 5A:
No action

Cessation of ground water extraction
and treatment with installation of
a new irrigation well.

Cessation of ground water extraction and
treatment with vacuum extraction of soils
containing organic compounds.

Continuation of existing ground water
extraction and treatment.

Enhancement of ground water extraction
and treatment by either increasing
on-site pumping or by the installation
of additional interceptor veil.

Continuation of existing ground water
extraction and treatment with additional
control of ground water containing
organic compounds.

Enhancement of ground water extract :=r.
and treatment by either increasing
on-site pumping or by the installat::-
of additional interceptor well, and
additional control of ground water
containing organic compounds.
                                 19

-------
     Alternative 6:
*    Alternative 6A:
*    Alternative 7:
*    Alternative 7A:
    Alternative 7B:
                              Continuation of existing ground wate~
                              extraction and treatment with in sit
                              flushing of the sand channel.

                              Enhancement of ground water extraction
                              and treatment by increasing on-site
                              pumping or by the installation of
                              additional interceptor well, with
                              in-situ flushing of the sand channel.

                              Continuation of existing ground water
                              extraction and treatment with vacuum
                              extraction of soil containing organic
                              compounds.

                              Enhancement of ground water
                              extraction and treatment by either
                              increasing on-site pumping or by the
                              installation of additional interceptor
                              well with vacuum extraction of soil
                              containing organic compounds.

                             Enhancement of ground water extraction
                             and treatment by either increasing
                             on-site pumping or by the installation
                             of additional interceptor well. Conduct
                             a pilot study to determine the
                             practicability of full scale vacuum
                             extraction of soil containing organic
                             compounds.

     Alternative 3 was not retained after the screening process
 (which is detailed in the FS report) since it did not reduce the
quantity of toxicity of contaminants in the aquifer. Alternatives
6 and 6A were not retained for further analysis due to technical
problems. These problems included the potential for mobilization
of metals and organic compounds which may subsequently prove
difficult to control.  The potential existed that these
constituents could migrate to the aquifer.

COMMON ELEMENTS

     Except for the "No Action1* alternative, all of the
alternatives b«ing considered for the site would include a number
of common domponents.  Alternatives 4, 4A, 5, 5A 7, 7A and 7B
include either the operation of the existing pump and treat
system that is currently being operated at the site or the
enhancement of this system.  All of the above stated alternatives
also include ground water monitoring to gauge the effectiveness
of the selected remedy.  In addition, the installation of
additional ground water monitoring wells will be necessary
downgradient of irrigation veil 154278 to determine if the
contaminated ground water plume extends past this veil.  This is
due to contamination detected in this well during the 1989
                           20

-------
irrigation season,  it is not known if these contaminants are
moving further downgradient.

     Listed below is a brief description of each alternative.   A
10 percent interest rate value was used to calculate present
worth.  Alternatives 5, 5A, 6, 6A, 7,  7A,  and 7B are all
modifications of Alternative 4 or 4A.

*    Alternative 2:

     Estimated Capital Cost:  $195,200
     Estimated Annual Operation and Maintenance (04M)
     Costs:  $89,600
     Estimated Implementation Time Frame:  10 years*
     Estimated Present Worth of Capital and Operating
     Costs:  $746,000

     Under this alternative, the existing ground water pump and
     treat system would no longer be operated.   However, a
     new irrigation well would be installed to replace
     irrigation well number 54278 (this well shows
     contamination during operation in the irrigation season).
     This new well would be designed to draw from ground
     water which is not hydraulically downgradient of the
     site.  A 16-inch diameter well would be constructed at
     an approximate depth between 120 and 170 feet.  In addition,
     deed restrictions affecting future ground water use
     would be established for portions of both the Lindsay
     and neighboring property southeast of the site until
     natural dispersion and advection reduces metal and organic
     contaminants in the ground water at the relevant areas of
     the site. Ground water monitoring would continue for
     ten years in order to gauge the potential impact of the
     cessation of the existing extraction and treatment
     operation.  This alternative is considered a limited action.

*    Alternative 4:

     Estimated Capital Cost:  $0.00
     Estimated Annual Operation and Maintenance (O&M)
     Costs:  $431,300
     Estimated Implementation Time Frame: 10 years*
     Estimated Present Worth of Capital and Operating
     Costa: $2,650,000

     UndMr this alternative the two existing extraction and
     treatment veils (Original Interceptor Well "OIW" and Add-on
     Interceptor Well "AOIW) currently being operated would
     continue to be used to extract ground water. The AOIW would
     continue to pump at its current design rats of 1000 gpm and
     the OIW would continue to pump periodically at approximately
     500 gpm.  The current treatment method employs alkaline
     precipitation of zinc salts with the addition of
     flocculating polymers in a mix tank, followed by
     sedimentation of the flocculant.  The existing system  is
                                 21

-------
described by the flow diagram in Figure vii-i.  It is
currently designed to handle up to 1,000 gallons per minute
 (gpm).  The devatered solid residuals are disposed of at a
local landfill,  supernatant is recycled to the treatment
system,  current data indicates that the system removes
approximately 700 pounds/day of zinc metal from the
influent.  Because treatment takes place in open tanks and
because organic compounds in the ground water are readily
stripped during agitation, the concentration of the organics
are reduced during the treatment process.  The treated water
is discharged to Dry Creek under an NPDES permit issued by
the State of Nebraska.

Alternative 4A:

Estimated Capital Cost:  $173,400
Estimated Annual Operation and Maintenance (OtM)
Costs:  $521,000
Estimated Implementation Time Frame: 5 years*
Estimated Present Worth of Capital and Operating
Costs: $2,148,000

Alternative 4A is a modified version of Alternative 4.  In
Alternative 4A, either the AOIW would be modified to
increase its pumping rate or an additional interceptor well
identified as TIW (for third interceptor well) would be
installed.  Either of two pumping methods arc applicable:
(1) modification of the AOIW to increase its pumping rate or
(2) the addition of a supplemental interceptor well between
the AOIW and the irrigation well southeast of the site.

Under method 1, the replacement wells would be designed to
produce approximately 1,400 gpm, which is the maximum yield
of the aquifer at this location.  Under method 2, the TIW
would be sited near the location shown on Figure 6 and would
be designed to produce 600 gpm.  This new well would
supplement the existing AOIW.  Under either method the Oiw
would continue to be pumped at an average rate of 600 gpm.

Treatment of ground water and discharge of treated water
would be conducted as described.  The current treatment
method employs alkaline precipitation of zinc salts with the
addition of flocculating polymers in a mix tank, followed by
sedimentation of the flocculant.  The existing system
is described by the flow diagram in Figure VII-1.  It is
currently designed to handle up to 1,000 gallons per minute
(gp»), but will increase as stated for this alternative.
The devatered solid residuals are disposed of by a
local landfill.  Supernatant is recycled to the treatment
system,   current data indicates that the system removes
approximately 700 pounds/day of zinc metal from the
influent.  Because treatment takes place in open tanks, and
because organic compounds in the ground water are readily
stripped during agitation, the concentration of the organics
is reduced during the treatment process.  The treated water
                            22

-------
 is discharged to Dry Creek under an NPDES permit issued by
 the State of Nebraska.

 Alternative 5:

 Estimated Capital Cost:  $59,600
 Estimated Annual Operation and Maintenance (O&M)
 Costs:  $431,300 (years 1-5)
 $436,300 (years 6-10)
 Estimated Implementation Time Frame: (10 years with future action)
 Estimated Present Worth of Capital and Operating
 Costs: $2,709,000

 This alternative im the same as Alternative 4 vith the
 addition of future controls to that system.  The additional
 system would include ground water extraction and treatment
 equipment designed specifically for the removal of organic
 compounds.  Under this alternative, an evaluation of the
 effectiveness of Alternative 4 extraction and treatment
 system would be performed at the end of five years of
 operation to determine if remedial action objectives have
 been met at that time.  The evaluation would be specific to
 organic compounds and would estimate the rate of removal of
 these compounds from the affected areas, the mass remaining
 in the soils and ground water, and the time until remedial
 action objectives would be achieved.  If future action were
determined to be necessary, ground water containing organic
 compounds would be extracted from the area near the north
 side of the main production building (current data shows
 this to be the area with the highest concentrations of
 organics in the soil).  The extracted water would be routed
 to a treatment system specifically designed to remove
 organic compounds.   Either activated carbon or aeration
 treatment would be used.  The organic compounds detected in
ground water are readily absorbed onto activated carbon or
 removed from water through aeration.  The type of extraction
 system, treatment,  system size, and flow rates would be
designed to provide sufficient contact time between the
water containing organic compounds and the treatment medium
 (air or carbon).

Alternative 5A:

Estimated capital Cost:  $173,400
Estimated Annual Operation and Maintenance (OtM)
Co«t«s  $521,000
Estiaated Implementation Time Frame: 5 years
Estimated Present Worth of Capital and Operating
Costs: $2,367,000

This alternative is the same as Alternative 4A vith the
addition of future controls to that system.  The additional
system would include ground water extraction and treatment
equipment designed specifically for the removal or organic
compounds.  Under this alternative, an evaluation of


                            23

-------
the effectiveness of Alternative 4A enhanced extraction and
treatment system would be performed at the end of five years
of operation if remedial objectives have not been met at
that time.  The evaluation would be specific to organic
compounds and would estimate the rate of removal of these
compounds from the affected areas, the mass remaining in the
soils and ground water, and the time until remedial
objectives would be achieved. If future action were
determined to be necessary, ground water containing organic
compounds would be extracted from the area near the north
side of the main product building (current data shows this
to be the area with the highest concentrations of organics
in the soil).  The extracted water would be routed to a
treatment system specifically designed to remove organic
compounds.  Either activated carbon or aeration treatment
would be used. The organic compounds detected in ground
water are readily absorbed onto activated carbon or removed
from water through aeration.  The type of extraction system,
treatment, system size, and flow rates would be designed
to provide sufficient contact time between the water
containing organic compounds and the treatment medium (air
or carbon).

Alternative 7:

Estimated Capital Cost:  $1,366,400
Estimated Annual Operation and Maintenance (O&M)
Costs:  $546,900 (years 1-5)
        $431,300 (years 6-10)
Estimated Implementation Time Frame: 10 years
Estimated Present Worth of Capital and Operating
Costs:  $4,346,000

This alternative would add vacuum extraction of organic
compounds in the soil to the existing ground water
extraction and treatment system described in Alternative 4.
Soil vapor extraction in areas of the Lindsay site where
organic compound* have been detected would be designed to
remove organic compounds at a higher rate than is offered by
well-induced gravity drainage and ground water extraction
alone. Each soil vapor extraction well would have a 2 inch
diameter casing in a 4 inch boring extending down to
near the water table.  It is anticipated that the easing
would be screened at least 10 feet below ground surface to
minimise short circuiting (extraction of surface air rather
than organic vapors in the soil).  The PVC casing end screen
would be suitably sand-packed and sealed.  It would
terminate in e vacuum header.  The network of header
attachments would be grouped into the north and south
systems with the plant ditch being the dividing line.  The
vacuum sources would include four positive displacement
blowers, each rated et 250 cfm and equipped with 25 HP
motor.  Extracted vapors would flow through a carbon
adsorption filter prior to release to the environment.  Air
emissions will meet all applicable ambient air quality
                            24

-------
standards established for the state of Nebraska. It is
estimated that approximately 250 extraction wells would be
needed to fully cover all soil areas contaminated with
organics.  This estimation is based on the radius of
influence of each extraction well being 25 feet.

Alternative 7A:

Estimated Capital Cost:  $1,539,800
Estimated Annual Operation and Maintenance (O&M)
Costs:  $636,600
Estimated Implementation Time Frame: 5 years
Estimated Present Worth of Capital and Operating
Costs: $3,800,000

Alternative 7A would add vacuum extraction of organic
compounds to the enhanced aquifer ground water extraction
and treatment described for Alternative 4A.  Soil vapor
extraction in areas of the Lindsay site where organic
compounds have been detected would be designed to remove
organic compounds at a higher rate than is offered by well-
induced gravity drainage and ground water extraction alone.
Each soil vapor extraction well would have a 2 inch diameter
casing in a 4 inch boring extending down to near the
water table.  It is anticipated that the casing would be
screened at least 10 feet below ground surface to minimize
short circuiting (extraction of surface air rather than
organic vapors in the soil).  The PVC casing and screen
would be suitably sand-packed and sealed.  It would
terminate in a vacuum header.  The network of header
attachments would be grouped into the north and south
systems with the plant ditch being the dividing line.  The
vacuum sources would include four positive displacement
blowers, each rated at 250 cfm and equipped with 25 HP
motor.  Extracted vapors would flow through a carbon
adsorption filter prior to release to the environment.
Air emissions will meet all applicable ambient air quality
standards established for the state of Nebraska.  It is
estimated that approximately 250 extraction veils would be
needed to fully cover all soil areas contaminated with
organics.  This estimation is based on the radius of
influence of each extraction well being 25 feet.

Alternative 7B:

Estimated capital Cost:
          $544,857 + $48,630 (Pilot Study) - $593,500
Estimated Annual Operation and Maintenance (O&M)
Costs:  $636,600
Estimated Implementation Time Flame: 5 years
Estimated Present Worth of Capital and Operating
Costs: $3,006,600

Alternative 7B would add vacuum extraction of organic
compounds from soils (if determined to be practicable as a
                            25

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              FIGURE   VII- 1

         ALTERNATIVE  4
                 Process Flow Diagram
 Existing Groundwaler Treatment System
             Lindsay Manufacturing Co.
                   Lindsay . Nebraska
	 Dames * Moore.

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                FIGURE  VII-2
Pro;jor*d Location ol New Interceptor Wei
              Lindsay Manufacturing Slta
	Oames & Moore.

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     result of the pilot study) to the enhanced aquifer ground
     water extraction and treatment described for Alternative 4A.
     Alternative 78 would employ a soil vapor extraction pilot
     study to determine the practicability of vacuum extraction
     technology on removing volatile organic compounds from the
     soils at the Lindsay site.  Soil vapor extraction in areas
     of the Lindsay site where organic compounds have been
     detected would be designed to remove organic compounds at a
     higher rate than is offered by well-induced gravity drainage
     and ground water extraction alone.  Each soil vapor
     extraction well would have a 2 inch diameter casing in a 4
     inch boring extending down to near the water table.  It is
     anticipated that the casing would be screened at least 10
     feet below ground surface to minimize short circuiting
     (extraction of surface air rather than organic vapors in the
     soil).  The PVC casing and screen would be suitably sand-
     packed and sealed.  It would terminate in a vacuum header.
     The network of header attachments would be grouped into the
     north and south systems with the plant ditch being the
     dividing line.  The vacuum sources would include four
     positive displacement blowers, each rated at 250 cfm and
     equipped with 25 HP motor.  Extracted vapors would flow
     through a carbon adsorption filter prior to release to the
     environment.  Air emissions will meet all applicable ambient
     air quality standards established for the state of Nebraska.
     A re-estimation of the number of extraction wells outlined
     in Alternative 7A was completed.  It was estimated that a
     total of 100 soil vapor extraction wells would be sufficient
     to cover the area of organic contamination in the soil.  The
     same assumptions utilized in Alternative 7A were utilized.
     In summary, an estimate of 20 extraction wells would be
     installed in the sand channel and 80 extraction veils would
     be installed in the clay/silt soils underlying the main
     plant building. Note that if the outcome of the pilot study
     proves that soil vapor extraction is practicable, the design
     of the system using actual data derived during the study
     will determine the actual number of extraction wells that
     would be required to effectively remove the organic
     compounds from the soil.


VIII.  SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES

     EPA uses nine criteria to evaluate the identified remedial
alternatives in order to selective a preferred
alternative/alternatives.  The nine evaluation criteria are
summarised.

Threshold Criteria

1.   OVERALL PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
addresses whether or not a remedy provides adequate protection
and describes how risks posed through each pathway are
eliminated, reduced or controlled through treatment, engineering
controls,  or institutional controls.


                                 26

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2.   COMPLIANCE WITH ARARs addresses whether or not a remedy will
meet all of the applicable or relevant and appropriate
requirements of other Federal and State environmental statutes
and/or provides grounds for invoking a waiver.

Primary Balancing Criteria

3.   LONG-TERM EFFECTIVENESS AND PERMANENCE refers to the ability
of a remedy to maintain reliable protection of human health and
environment over time once cleanup goals have been met.

4.   REDUCTION OF TOXICITY, MOBILITY, OR VOLUME is the
anticipated performance of the treatment technologies a remedy
may employ.

5.   SHORT-TERM EFFECTIVENESS addresses the period of time needed
to achieve protection, and any adverse impacts on human health
and the environment that may be posed during the construction and
implementation period until cleanup goals are achieved.

6.   IMPLEMENTABILITY is the technical and administrative
feasibility of a remedy, including the availability of materials
and services needed to implement a particular option.

7.   COST includes estimated capital and operation and
maintenance costs, and net present worth costs.

Modifying Criteria

8.   STATE ACCEPTANCE indicates whether, based on its review of
the RI/FS and Proposed Plan, the State concurs in, opposes, or
has no comment on the preferred alternative at the present time.

9.   COMMUNITY ACCEPTANCE is assessed in the Record of Decision
following a review of the public comments received on the RI and
FS reports, the administrative record, and the Proposed Plan.

     This section profiles the performance of the. alternatives
against the nine criteria.

OVERALL PROTECTION.  All of the alternatives, with the exception
of the "no action" alternative, would provide adequate protection
of human health and the environment by eliminating, reducing, or
controlling risk through treatment, engineering controls, or
institutional controls.  Alternatives 4/4A, 5/5A, and 7/7A/7B
provide extraction and treatment of ground water, and ara
therefore equivalent in overall protection of human health and
the environment.  The soil vacuum extraction technique of
Alternativas 7/7A/7B offers additional protection because the
volatile organics may ba removed from the soils, if this
technology proves to be practicable during the pilot study to be
conducted as part of Alternative 7B.  Application of Alternative
2 provides protection of human health, but would result in


                                 27

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restrictions of future development of the ground water resource.
Because the "no action" alternative is not protective of human
health and the environment, it is not considered further in this
analysis as an option for this site.

COMPLIANCE WITH ARARS.  All alternatives would meet their
respective applicable or relevant and appropriate requirements of
Federal and State Regulations. Application of Alternative 2
(natural attenuation of ground water)  would require the longest
time frame to reach compliance.

LONG TERM EFFECTIVENESS AND PERMANENCE.  Alternatives 7/7A/7B
would reduce the inherent hazards posed by the volatile organic
compounds in the soils.  By removing the volatiles from the soils
through soil vapor extraction this would prevent the further
migration of contaminants to ground water and other soils.  The
enhanced extraction and treatment system would contain the
contaminant plume and also remove the contaminants.  Under
Alternatives 4, 4A, 5, 5A, and 7/7A/7B the remedial action
objectives for ground water would be met.  The remedial action
objectives for the Lindsay site are the state and EPA primary and
secondary Maximum Contaminant Levels (MCLs) for drinking water
for potential future use of the ground water as a public health
and aesthetically protected drinking water source.

     Alternative 2 would eliminate potential pathways of exposure
associated with potential future use of ground water, but does
not offer long-term controls comparable of those of other
alternatives.

REDUCTION OF TOXICITY, MOBILITY, OR VOLUME.  The only alternative
which does not immediately treat the contaminants to reduce the
toxicity, mobility, or volume of the organics and metals is
Alternative 2.  For this alternative it is assumed that
contaminants would eventually be removed through natural
attenuation, but the tin* required for natural processes to
reduce the toxicity, nobility, or volume of contaminants is
likely to be much longer than the time required using engineered
extraction techniques employed by the other alternatives.
Alternatives 4/4A and 5/5A offer extraction and treatment of
ground water and are equivalent in reduction of contaminant
mobility, toxicity, and volume in the ground water but not in
site soils.  Alternatives 7/7A/7B would permanently remove
contaminants from the soil (if this technology proves to be
practicable) in Alternative 7B) and ground water thereby raducing
the voluM of contaminants, raducing the toxicity and raducing
the mobility.

SHORT TERN EFFECTIVENESS.  Alternatives 4A, 5A, 7A, 7B, offer the
greatest potential for rapid achievement of remedial objectives.
Installing and operating a naw extraction wall in an appropriate
location would dacraaaa the time required to raduca
concentrations in ground water of metals and organic compounds.
Alternatives 4, 5, and 7, ara likely to be longer than
Alternatives 4A/5A/7A/7B in achieving remedial objectives because


                                 28

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they do not include enhanced extraction of ground water.
Alternatives 7A and 7B may offer advantages of time over
Alternatives 5A and 4A because of the proposed vacuum extraction
techniques.  Alternative 2 relies on natural processes rather
than engineered systems and therefore is the longest-term alternative

IMPLEMZNTABILITY.  Few associated administrative difficulties
that could delay implementation are associated with any
alternative. Since Alternatives 4, 4A, 5, 5A, 7, and 7A require
the use of the currently operating extraction and treatment
system, no problems are anticipated with the continued operation
of this system.  Note that Alternatives 4A, 5A, and 7A call for
the enhancement of the current system but no problems with
implementation are anticipated since this technology has been
used extensively.  Skilled workers needed to construct the
enhanced ground water treatment system are available in the area.
Lindsay personnel are familiar with this system since it has been
in operation for six years.  The activated carbon canisters that
are part of the soil vapor extraction system in alternatives 7A
and 7B should be available in the area.  Since soil vapor
extraction for the treatment of soils has not been done in the
area a pilot study should be completed to determine the
effectiveness of this process on site soils.  The practicability of
this method for soil treatment would be assessed during the pilot
study.  The technology has been used to address similar
contaminants at other Superfund sites.

COST.  Because Lindsay would cease operation of the extraction
system under Alternative 2, and because the alternative involves
the smallest capital equipment expenditure, it is the lowest cost
alternative.  Continued operation and maintenance costs of the
treatment system incurred under Alternatives 4 and 5 make these
systems moderately costly.  For Alternatives 4A and 5A,
additional treatment capacity and additional piping systems would
be required to enhance the effectiveness of remediation.
However, because these additional measures may reduce the time
required to meet remedial objectives, cost savings nay result.
Alternatives 7/7A/7B would involve installation of vapor
extraction wells and are estimated to cost nearly twice as much
as Alternative 4A, however they may provide enhanced protection
of human health and the environment. Costs are shown in Table
Viil-i.  Alternative 7A is determined infeasible for tvo reasons:
(1) 250 extraction wells are excessive for an active site; and
(2) no pilot study has been recommended.

     Alternative 7B is the preferred alternative for the Lindsay
site basad en how it compares to all the other options under
consideration.  The strongest elements of Alternative 7B are the
following:

(1)  the alternative provides long-term effectiveness and
permanence; and

(2)  the alternative reduces toxicity, mobility, and volume. The
alternatives are evaluated based on the nine EPA criteria.


                                 29

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STATE AND SUPPORT AGENCY ACCEPTANCE.  Both the State of Nebraska
and U.S. EPA support the preferred alternative.

COMMUNITY ACCEPTANCE.  Comments received during the public
comment period shows that the community supports remediation at
the site.  There were no comments from community members against
the preferred alternative except for Linday's comments on the
pilot study.


IX.  SELECTED REMEDY

*    Alternative 7B:
     Estimated Capital Cost:
       $544,857 * $48,630 (Pilot Study) - $539,500
     Estimated Annual Operation and Maintenance (O&M)
     Costs:  $636,600
     Estimated Implementation Time Frame: 5 years*
     Estimated Present Worth of Capital and Operating
     Costs: $3,006,600

     The preferred alternative for cleanup of the Lindsay site is
Alternative 7B.  For the treatment of ground water, the preferred
alternative would utilize an enhanced version of the ground water
extraction and treatment system currently being operated.
Simultaneously a soil vapor extraction pilot study would be run
to determine the practicability of this technology on removing
volatile organic compounds (VOC) from the soils at the Lindsay
site.   If determined to be practicable, this remedy will include
the extraction of VOCs from the soils that are a source of
contamination to the aquifer.

     Alternative 7B is considered to be preferable to all other
alternatives including 7A because it should reduce contaminant
volume,  toxicity, and mobility to the greatest extent, and the
soil vapor extraction pilot study will determine the
practicability of soil treatment.  Alternative 7B addresses two
contaminated media, ground water and soils.

1)   Contaminated Ground Water

     The existing ground water extraction and treatment system
     would b« enhanced either by increasing on-site pumping or by
     the installation of an additional interceptor wall aa
     described below. Either the AOIW would be modified to
     increase ita pumping rate or an additional intarcaptor wall
     identified aa TIW (for third interceptor wall) would ba
     installed.  Either of two pumping methods are applicable:

     a)  modification of the AOIW to increase ita pumping rate or
     b)  the addition of a supplemental interceptor well between
        the AOIW and the irrigation well 154278 southeast of the
        site.
                                 30

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     The current pumping system would be enhanced either by
     increasing the rate of the AOIW *o 1,400 gpm or by
     installing a third extraction well, identified as TIW, to
     supplement the present AOIW.  The AOIW is presently designed
     to pump 1,000 gpm.  To enhance ground water extraction this
     well must be either replaced by a larger well at the same
     location or adjacent to the existing location.  Under method
     a., the replacement wells would be designed to produce
     approximately 1,400 gpm, which is the maximum yield of the
     aquifer at this location.  Under method b., the TIW would be
     sited near the location shown on Figure VII-2 and would be
     designed to produce 600 gpm.  This new well would supplement
     the existing AOIW.  Under either method the OIW would
     continue to be pumped at an average rate of 600 gpm.
     Treatment of ground water and discharge of treated water
     would be conducted as described.  The currently treatment
     method employs alkaline precipitation of zinc salts with the
     addition of flocculating polymers in a mix tanX, followed by
     sedimentation of the flocculant.  The existing system is
     described by the flow diagram in Figure VIl-l.  It is
     currently designed to handle up to 1,000 gallons per minute
     (gpm),  but will increase as stated for this alternative.
     The dewatered solid residuals are disposed of at a local
     landfill.  Supernatant is recycled to the treatment system.
     Current data indicates that the system removes approximately
     700 pounds/day of zinc metal from the influent.  Because
     treatment takes place in open tanks, and because organic
     compounds in the ground water are readily stripped during
     agitation, the concentration of the organics are reduced
     during the treatment process.  The treated water is
     discharged to Dry Creek under an NPDES permit issued by the
     State of Nebraska.

2)    Contaminated Soil

     This portion of the remedy includes a pilot study to
     determine the practicability of removing volatile organic
     compounds from the soils using soil vapor extraction, and if
     practicable, the extraction of VOCs from soils.  Outlined
     below are the assumptions that will be used during the pilot
     study:

          Duration of pilot study - four (4) weeks

          Two 2 inch Schedule 80 PVC extraction veils to be
          Installed at a depth of at least 35 feet  (in the areas
          of highest contamination)

          Extraction veils screens will be 15 feet long with
          Schedule 80 PVC 50 slot screen

          Use 1/4 inch pea gravel for the veil screen pack

          One blower per veil venting to the atmosphere
          (two blowers total)


                                 31

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          Soil vacuum will *>e measured to assess radius of influence

          A total of 22 soil vapor samples will b« collected and
          analyzed for tetrachloroethene, 1,1,1,-trichloroethane,
          dichloroethane, and dichloroethene using U.S. EPA
          Method 8010.

     A re-estimation of the number of the 250 extraction
     wells outlined in Alternative 7A was completed.  Alternative
     7A is considered to not be feasible because 250 soil vapor
     extraction wells would be excessive for an operating
     facility. It was estimated that a total of 100 soil vapor
     extraction wells would be sufficient to cover the area of
     organic contamination in the soil, for the selected
     Alternative 7B.  The same assumptions utilized in
     Alternative 7A were utilized.  In summary, an estimate of 20
     extraction wells would be installed in the sand channel and
     80 extraction wells would be installed in the clay/silt
     soils underlying the main plant building.  Note that if the
     outcome of the pilot study proves that soil vapor extraction
     is feasible, the design of the system using actual data
     derived during the study will determine the actual number of
     extraction wells that would be required to effectively
     remove the organic compounds from the soil.

     U.S. EPA and NDEC will evaluate other treatment or
     source control measures in the event that the pilot shows
     that this technology is not practicable.  Subject to the
     outcome of the pilot study, EPA will consider reopening or
     amending the ROD if warranted, otherwise the agency will
     proceed with the selected remedy.  If soil vapor extraction
     is determined not to be practicable, the Agency will
     consider an additional study to evaluate other treatment
     technologies or source control measures to reduce or
     eliminate the source(s) of contamination to ground water.
     If no technologies are shown to be practicable, the VOCs in
     the soil will be eliminated through the continued operation
     of the enhanced extraction and treatment system.  As the
     vocs are released from on-site soils to ground water the
     ground water will be extracted and treated.

     In addition, the selected remedy will require installation
of additional monitoring wells to monitor ground water quality
down gradient of irrigation well 154278.  The cost of the  .
additions*: veils is not included in the present worth of the
selected vsmedy, since additional monitoring veils would have
been needed regardless of the remedy selected.  This cost was not
included in the cost estimate of any of the Alternatives.

     If appropriate to protect human health, as part of the
implementation of this ROD, EPA and NDEC will evaluate options to
ensure that drinking water wells are not installed in areas of
the contaminant plume on and off site.
                                 32

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     Some changes may be made to the selected remedy as a result
of the remedial design and construction process.  Such changes in
general will reflect modifications resulting from the engineering
design process.


X.   STATUTORY DETERMINATIONS

     Under its legal authorities, the Environmental Protection
Agency's primary responsibility at Superfund sites is to
undertake remedial actions that achieve protection of human
health and the environment.  In addition, sections 121 of CERCLA
establishes several other statutory requirements and preferences.
These specify that when complete, the selected remedial action
for this site must comply with applicable or relevant and
appropriate environmental lavs unless a statutory waiver is
justified.  The selected remedy also must be cost effective and
utilize permanent solutions and alternative treatment
technologies or resource recovery technologies to the maximum
extent practicable.  Finally, the statute includes a preference
for remedies that employ treatment that permanently and
significantly reduce the volume, toxicity, or mobility of
hazardous wastes as their principal element.  The following
sections discuss how the selected remedy meets these statutory
requirements.

1.   Protection of Human Health and the Environment

     The selected remedy protects human health and the
environment through extraction and treatment of contaminated
ground water and soil vapor, if soil vapor extraction is
determined practicable during the pilot study.  The contaminants
will be permanently removed from the ground water and from the
soil through volatilization of active soil vapor extraction.

     Extraction of the contaminated ground water will also
eliminate the threat of exposure due to the spread of
contamination to a larger area by checking the migration of the
plume.  If soil vapor extraction is determined to be practicable
during the pilot study, volatilization of contaminants from site
soils will eliminate the source of continued contamination of the
ground water thus reducing the time needed for remediation.

2.   Compliance with Applicable or Relevant and Appropriate.Requirements

     The selected remedy, enhanced ground water extraction and
treatment end a pilot study to determine the practicability of
soil vapor extraction on removing volatile organic* from site
soils will comply with all applicable or relevant and appropriate
chemical-, action-, and location-specific requirements  (ARARs).
The ARARs are presented below.
                                 33

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Action-SDecifi,^ ARARs;

     Clean Water Act requirements under 40 CFR 122-125 for point
source direct discharge.  Under the National Pollutant Discharge
Elimination System  (NPDE5) effluent standards, monitoring
requirements, and standard conditions for discharge are set.
NPDES discharge limits for metals and pH will be met using
alkaline precipitation with the addition of flocculating polymers
in a mix tank, followed by sedimentation of the flocculant.
Discharge limits for VOCs will be met through treatment in open
tanks and agitation to promote volatilization during the above
stated process.  NPDES requirements will be met through
compliance with State regulation Title 119, Rules and Regulations
Pertaining to the Issuance of Permits Under the National
Pollutant Discharge Elimination System.

     Title 129, Nebraska Air Pollution Control Rules and
Regulations establishes a maximum limit for total volatile
organic compound emissions at 2.5 tons/year.  This emission level
applies to all processing machines, equipment or devices having
the potential to emit a regulated amount of toxics.  It is not
believed that Lindsay's manufacturing process emits VOCs.
Therefore, the limit applies to VOCs emitted during cleanup of
the site from the soil vapor extraction system and the ground
water treatment facility.  The soil vapor extraction system will
be designed so that the combination of air emissions will not
exceed regulated quantities.

     RCRA requirements, 40 C.F.R. Part 261 i£ seq. or Nebraska
Title 128, Rules and Regulations Governing Hazardous Waste
Management.  Under current RCRA requirements, the sludge produced
during the ground water treatment process is tested for EP
toxicity to determine whether waste sludge is hazardous and
therefore subject to RCRA requirements.  To date, sludge has not
been determined to be EP toxic.  Beginning September 25, 1990,
large quantity generators, and March 29, 1991 small quantity
generators (as defined in 40 C.F.R. Part 260.10), must test
wastes  produced in accordance with the Toxicity Characteristic
Leaching Procedure (TCLP) 55 £tli Eta- 11798 i£ ug. (March 29,
1990) in determining whether such waste is a hazardous waste and
therefore subject to RCRA requirements.  Beginning on the
appropriate date, the sludge will be tested under the new TCLP
requirements and handled appropriately in accordance with RCRA
and State of Nebraska Title 128 including, Land Disposal
Restrictions of 40 C.F.R. Part 268, and EPA's Off-Site Disposal
Policy.

ChenieaJ-aaaeifte ARARst

     Safe Drinking Water Act (SDWA) Maximum Contaminant Levels
(MCLs)  for aquifers with Class I and Class II characteristics
(i>*> irreplaceable, current or potential drinking water
sources).
                                 34

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SDWA MCL for:

     1,2-dichloroethane is 5 ug/1
     1,1-dichloroethene is 7 ug/1
     cis-l,2-dichloroethene is 70 ug/1 (proposed MCL)
     trans-l,2-dichloro«thene is 100 ug/1 (proposed MCL)
     1,1,1-trichloroethane is 200 us/1
     pH range 6.5-8.5  (secondary MCL)
     zinc is 5,000 ug/1 (secondary MCL)
     sulfate is 250,000 ug/1 (secondary MCL)
     cadmium is 10 ug/1
     chromium is 50 ug/1
     lead is 50 ug/1

     State of Nebraska Rules and Regulations under Title 118
Ground Hater Quality Standards and Use Classification (State of
Nebraska Ground Water Clean-up Levels).  The above stated MCLs
are standards adopted for the State of Nebraska except for the
following:

     chromium 100 ug/1
     cadmium 5 ug/1 (proposed MCL)

     The more stringent of the ground water standards will be
applied to this site in determining when aquifer restoration
has been completed.  This will be assured through ground water
monitoring of the aquifer.

Location-Specific ARARs;

     A portion of the Lindsay facility is on the 100 year flood
plain.  However, the ground water treatment facility is located
outside the 100 year flood plain.  Therefore, there are no
location-specific ARARs that apply.

Other Criteria. Advisories fir. Guidance £a fee. Considered for this
Remedial Action (TBCslt

     For compounds without an MCL, proposed MCL or state ground
water standard, a risk based cleanup level corresponding to an
excess lifetime cancer risk of 1 x 10(-6) will be calculated
using slope factors for carcinogens.  In cases where these levels
are below a laboratory quantification limit the lowest attainable
detection linit will be used as the cleanup goal.

3.   Cost-Effectiveness

     The selected reMdy is cost-effective because it provides
the best balance among the evaluation criteria.  It provides a
higher degree of overall protection then the less costly
alternative by treating source areas and remediating ground
water.
                                 35

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 4.    Utilization of  Permanent  Solutions and Alternative Treatment
 Technologies  or Resource  Recovery Technologies to the Maximum
 Extent Practicable.

      EPA has  determined that the selected remedy represents the
 maximum extent  to which permanent solutions and treatment
 technologies  can be  utilized in a cost-effective manner for the
 site.   Of those alternatives that are protective of human health
 and  the environment  and comply with applicable standards, EPA has
 determined that this selected  remedy provides the best balance of
 trade-offs in terms  of long-term effectiveness and permanence,
 reduction in  toxicity, mobility, or volume achieved through
 treatment,  short-term effectiveness, implementability, cost,
 while  also considering the statutory preference for treatment as a
 principal element and considering State and community input.

     Best available  data  informed EPA and NDEC that elevated soil
 concentrations  ("hot spots") are contributing to ground water
 contamination northeast of the main plant building and in the
 north  central portion of  the site.

 5.   Preference for  Treatment  as a Principal Element

 •    The  selected remedy  uses  technology for ground water
 treatment and active soil vapor extraction, if proven practicable
 during  the  pilot  study, for source control and thus satisfies the
 statutory preference for  remedies that employ treatment of the
 principal threat  which permanently and significantly reduces the
 toxicity, mobility,  or volume,of hazardous substances as a
 principal element.


 XI.  RESPONSIVENESS  SUMMARY

 A.  Overview

     In the proposed plan released for public comment, EPA and
 NDEC presented  a  preferred alternative which addressed the soil
 and ground water  contamination at the Lindsay Manufacturing
 Companyxsite.

     After receiving public comment or the preferred alternative,
 EPA selected  this alternative  in the Record of Decision (ROD).
The selected  remedy  includes enhancing the current ground water
pumping sjysjts* either by modifying the AOIW to increase the
pumping rate  or installing an addition interceptor veil southeast
of the site.  Also included in the selected remedy is a pilot
 study to determine the effectiveness of soil vapor extraction of
volatile organic contaminants.   If determined to be practicable,
soil vapor extraction will be performed to aid in the elimination
of the source of ground water contamination.

     During the comment period, one community member expressed
concern that the site be cleaned up and that they be protected
 "in all ways".  No other comments by community members on the


                                 36

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preferred alternatives were submitted during the public comment
period.  The State Senator representing the district in which the
town of Lindsay is located stated that the preferred alternative
"was conceived after much research and forethought".  Lindsay
Manufacturing Company, the potentially responsible party (PRP)
for the site did not support the pilot study for soil vapor
extraction.  In their comment the PRP proposed a new alternative
if a soil treatment remedy was selected.

B.  Background on Community Involvement

     A community relations plan (CRP) for the site was developed
in June 1989.  Objective* of the CRP were to identify primary
issues and provide information to news media,  on November 17,
1989, a news release was issued which announced the availability
of the administrative record at the Columbus, Nebraska Library.
A public notice was published in the Omaha World Herald and the
Columbus Telegram on July 10, 1990 announcing the Public Hearing
and availability of the Proposed Plan and the administrative
record.  Prior to the public comment period for the Proposed
Plan, no significant public issues or concerns were communicated
to EPA or NDEC.

C.  Summary of Comments Received During Public Comment Period

     Significant comments presented during the public comment
period on the administrative record and the Proposed Plan are
summarized below.  The comment period was scheduled from July  16,
1990, to August 15, 1990.  At the request of Lindsay, the comment
period was extended to August 31, 1990.  The comments arc
categorized as general comments and comments specific to the
Proposed Plan.

General Comments

1.  One community member commented that the site be cleaned up
and they be protected.

EPA Response:  EPA has selected a remedy which will cleanup the
site to levels that are protective of human health and the
environment.
       V

2.  State Senator Jennie Robak commented that the preferred
alternative was conceived after much research and forethought and
that the cleanup bagin soon with the work don* expeditious in
nature.

EPA Responaa:  In addition to the abova response, EPA will begin
remedial dasign and remedial action activities aftar the ROD is
issued.

3.  Rimkus consulting Group (RCG), a consultant for The Hartford,
commented on the Remedial Investigation that volatile organic
contaminants have migrated from a sourca area other than the
former acid disposal pit deep into the soil at the sita.


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EPA Response:  EPA's selected remedy will address the soil
contamination, if the pilot study proves that soil vapor
extraction is practicable.

4.  Lindsay commented that the selection of soil vapor extraction
as the remedy to cleanup VOC contamination in the soils at the
site is not consistent with the National Contingency Plan (NCP)
as required by the Superfund law.

EPA Response:  EPA has selected soil vapor extraction as the
remedy for the treatment of VOC contaminants at the site.  This
treatment technology will address the principal threat of VOC
contamination to the aquifer.  In order to assure this treatment
technology is practicable, EPA has selected to use a pilot study.
If soil vapor extraction is shown to be impracticable, EPA will
evaluate other treatment technologies or controls for VOC
contamination source areas.  This is consistent with 40 CFR
§ 300.430(a)(iii)(A) and.(B) of the NCP.

Specific Comments to the Proposed Plan

1.   Lindsay submitted several comments opposing soil vapor
extraction due to possible technical problems and questioned the
cost effectiveness.

EPA Response:  As stated in the response to General Comment 14,
EPA selected a pilot study to determine if this technology is
practicable and believes that soil vapor extraction, if
practicable,  is necessary to address the source(s) of volatile
organic compound contamination to the aquifer.

2.   Lindsay submitted comments opposing EPA's and NDEC's
evaluation of risk associated with the site.

EPA Response:  EPA and NDEC have determined the site poses
substantial risk to human health and the environment and that the
remedial action identified in the Proposed Plan is necessary and
appropriate.
         X
3.   Lindsay commented that dates for submittal of RI/FS reports
were not included in the proposed plan and that the Proposed Plan
did not include the volume of ground water treated to date..'

EPA Response:  This information is included in the administrative
record and does not affect the remedy identified in the Proposed
Plan.

4.   Lindsay commented that Appendix B of the proposed plan
(Maximum concentrations of Contaminants and Maximum Contaminants
Levels (MCLS)) does not reflect current concentrations of
contaminants at the site and that some of the listed contaminants
did not have analytical validation.
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EPA Response:  As explained in the Proposed Plan, Appendix B
presents maximum concentrations of contaminants detected either
on-site or off-site.  Current concentrations of contaminants are
provided in quarterly reports submitted by Lindsay.  These
reports are included in the administrative record.  EPA and NDEC
acknowledge that some of these contaminants have not been found
in recent sampling.

5.   Lindsay commented that the Proposed Plan incorrectly
indicates the need for additional ground water monitoring wells.

EPA Response:  As stated in the Proposed Plan, irrigation well
#54278 detected contamination during the 1989 irrigation season.
This has been verified with 1990 sampling results.  Sampling
conducted in August 1990 by NDEC showed VOC contamination at
levels greater than MCLs.  Additional ground water monitoring
wells will need to be installed to determine if contamination is
migrating further downgradient.

6.   Lindsay proposed a new alternative in the event a soil
treatment remedy is selected.  This alternative consisted of
additional shallow ground water interceptor wells to de-water
site soils above the aquifer.

EPA Response:  EPA has selected soil vapor extraction as the
remedy to remove VOC contamination from the site soils.  It the
pilot study shows this technology to be impracticable, EPA will
consider the above stated alternative when evaluating other
technologies or controls to address VOC source areas.
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