EPA/ROD/R07-98/026
                                    1998
EPA Superfund
     Record of Decision:
     ORONOGO-DUENWEG MINING BELT
     EPA ID:  MOD980686281
     OU04
     JASPER COUNTY, MO
     07/29/1998

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                                            RECORD OF DECISION
                                                DECLARATION

SITE NAME AND LOCATION

    Oronogo/Duenweg Mining Belt Site, Operable Unit 4
    Jasper County, Missouri

STATEMENT OF BASIS AND PURPOSE

       The U.S.  Environmental Protection Agency (EPA)  has prepared this decision document to present the
selected remedial action for ground water at the Oronogo/Duenweg Mining Belt Site located in Jasper
County, Missouri.  This decision was chosen in accordance with the Comprehensive Environmental Response,
Compensation and Liability Act  (CERCLA), as amended by the Superfund Amendments and Reauthorization Act
(SARA), and to the extent practicable, the National Contingency Plan  (NCP).   This decision is based on
the Administrative Record for this Site.  The Administrative Record file is located in the following
information repositories:

          1.     Joplin Public Library       3.     Carl Junction City Hall
                 300 Main                           105 North Main
                 Joplin, Missouri                   Carl Junction, Missouri

          2.     Webb City Public Library    4.     U. S. Environmental Protection Agency
                 101 South Liberty                  726 Minnesota Avenue
                 Webb City, Missouri                Kansas City, Kansas

       The EPA has coordinated selection of this remedial action with the Missouri Department of Natural
Resources (MDNR).  The State of Missouri concurs on the selected remedy.

ASSESSMENT OF THE SITE

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

DESCRIPTION OF THE SELECTED REMEDY

       This selected remedy deals with providing safe drinking water supplies to residents currently
consuming ground water contaminated with metals.  This cleanup action is one part of the EPA's overall
efforts under Superfund to deal with environmental contamination resulting from historic mining and
smelting operations in Jasper County.  Ground water contaminated solely from other sources will not be
addressed by this cleanup action.  Cleanup activities of metals contaminated residential yards have
already been implemented.  In the future, additional cleanup actions for the Site will deal with surface
mining and milling wastes.  This phased approach to the cleanup is being used for this Site in order to
clean up the contamination which poses the greatest health threat first.  The EPA believes that the
selected remedy will be consistent with future cleanups that will be done at the Site.

       The major components of selected remedy are:

       •      Support to Public Water Supply District #3 in the Oronogo/Duenweg Designated Area (DA)
       •      Extension of existing public water lines in the Oronogo/Duenweg DA
       •      Extension of existing public water lines in the Irons Gates Extension DA
       •      Installation of point-of-use treatment units to homes not accessible to public water
       •      A maintenance program for the point-of-use treatment units
       •      A monitoring program for threatened homes and the point-of-use treatment units
       •      Institutional controls to regulate future uses of the contaminated shallow aquifer

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STATUTORY DETERMINATIONS

       The selected remedy is protective of human health and the environment,  complies with location- and
action-specific federal and state requirements that are legally applicable or relevant and appropriate to
the remedial action and is cost-effective.  However, a waiver of certain chemical-specific applicable or
relevant and appropriate requirements is justified because of the technical impracticability of achieving
these requirements for this Site.  This remedy utilizes permanent solutions to the maximum extent
practicable.  Other than five point-of-use treatment units, treatment of ground water was not found to be
practical and this remedy does not satisfy the statutory preference for treatment as the principal
element.

       Because this remedy will result in hazardous substances remaining on the Site above health-based
levels, a review will be conducted within five years to ensure that the remedy continues to provide
adequate protection of human health and the envirorunent.

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                                       RECORD OF DECISION

                                          GROUND WATER
                                        OPERABLE UNIT 04
                                ORONOGO/DUENWEG MINING BELT SITE
                                     JASPER COUNTY,  MISSOURI
                                          Prepared by:

                              U.  S.  Environmental Protection Agency
                                           Region VII
                                      726 Minnesota Avenue
                                    Kansas City,  Kansas 66101

                                          July 1998

                                        TABIiE OF CONTENTS

SECTION                                                                       PAGE

1.0  Site Name, Location,  and Description 	1

2 . 0  Site History and Enforcement Activities 	3

3.0  Highlights of Community Participation 	3

4 . 0  Scope and Role of Operable Units 	4

5.0  Summary of Site Characteristics 	6

6. 0  Summary of Site Risks 	9

     6.1  Methodology 	10
     6.2  Results:   Shallow Aguifer Risk  	11
     6.3  Results:   Deep Aguifer Risks 	11
     6.4  Ecological Risks 	11

7.0  Remedial Action Obj ectives 	12

8 . 0  Summary of the Alternatives	12

9. 0  Evaluation of the Alternatives	16

9.1  Threshold Criteria 	16
     9.1.1  Overall Protection of Human Health and the Environment	16
     9.1.2  Compliance with ARARs 	17
9. 2  Balancing Criteria 	18
     9.2.1  Long-Term Effectiveness 	18
     9.2.2  Short-Term Effectiveness 	19
     9.2.3  Reduction in Toxicity, Mobility,  or Volume Through
            Treatment 	19
     9.2.4  Implementability 	20
     9.2.5  Cost Effectiveness 	20
9.3  Modifying Criteria 	20
     9.3.1  State Acceptance 	20
     9.3.2  Community Acceptance 	21

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                                        Table of Contents
                                           (continued)

10 . 0  The Selected Remedy 	21

      10.1  Public Water Supplies	21
      10.2  Point-of-Use Treatment Units	22
      10.3  Monitoring Program	22
      10.4  Institutional Controls	25
      10.5  Cost	25
      10.6  Operation and Maintenance	26
      10.7  Five-Year Review	26

11. 0  Statutory Determinations	28

      11.1  Protection of Human Health and the Environment	28
      11.2  Attainment of Applicable or Relevant and Appropriate Reguirements of
            Environmental Laws	28
            11.2.1  Chemical-Specific ARARs  	28
            11.2.2  Location-Specific ARARs	29
            11.2.3  Action-Specific ARARs	29
      11.3  Cost-Effectiveness	29
      11.4  Utilization of Permanent Solutions and Alternative Treatment
                    Technology to the Maximum Extent Practicable	29
      11.5  Preference for Treatment as a Principal Element	33

12 . 0  Documentation of Significant Changes	33

Figure 1    Jasper County Site Map	2
Figure 2    Oronogo/Duenweg Designated Area Expansion	7
Figure 3    Oronogo/Duenweg Designated Area Public Water
            Supply Lines and Point-of-Use Treatment Units	23
Figure 4    Iron Gates Extension Designated Area Public Water
            Supply Lines and Point-of-Use treatment Units	24

Table 1     Concentration of Selected Metals in Shallow and Deep Aguifers	8
Table 2     Alternative Descriptions	14
Table 3     Cost Estimate for Alternative 6A	27
Table 4     Chemical-Specific ARARS	30
Table 5     Location-Specific ARARS	31
Table 6     Action-Specific ARARS	32

Attachments

      1     Technical Impracticability Information
      2     Responsiveness Summary

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1.0    Site Name, Location, and Description

       This Record of Decision (ROD)  has been developed by the United States Environmental Protection
Agency  (EPA) to select a remedial alternative for the ground water at the Oronogo/Duenweg Mining Belt
Site in Jasper County, Missouri  (commonly known as the Jasper County Site, herein the "Site").  This ROD
is published in accordance with the reguirements of Section 117 of the Comprehensive Environmental
Response, Compensation and Liability Act(CERCLA, also referred to as the Superfund Law), 42 U.S.C. °9617.

       The Jasper County Site is part of the Tri-State Mining District,  which covers hundreds of sguare
miles in southwestern Missouri, southeastern Kansas, and northeastern Oklahoma.  Mining, milling, and
smelting of lead and zinc ore date back to 1850 and continued in the district until the 1970s.  The
Missouri portion of the district accounted for more than 0.2 billion short tons of ore, 80 percent of
which was produced in Jasper County.   Processing of the ore resulted in approximately 150 million short
tons of wastes.  Mining, milling, and smelting activities generated several types of waste materials
including mine wastes (waste rock, development rock, and overburden), mill wastes (chat and fine
tailings), and smelter-related materials  (slag, fugitive dust, and air emissions).   Approximately nine
million tons of mining/milling and  smelter wastes remain on the surface at the Site and contain residual
heavy metals, particularly lead, cadmium, and zinc.  These wastes currently contribute metals
contamination to surface soils, surface water, and ground water.  Additionally, most mining occurred
underground at depths up to 400 feet resulting in hundreds of mine shafts, many miles of mine adits, and
vast underground voids throughout the Site.  These mine openings create conduits for migration of metals
contamination into the ground water from the surface, as well as, highly oxygenated water which tends to
dissolve residual minerals in the rock formations.  Residual mineral deposits left in the mines also
contribute to the ground water contamination.

       Ground water addressed by this ROD is located within the Jasper County Site,  which is part of the
Tri-State Mining District and is shown on Figure 1.  The Site lies within an area bounded on the north by
the township line between Townships 29 and 30 North, on the south by the county line between Jasper and
Newton Counties, but also including portions of Section 24 Township 27 North Range 34 West and Sections
19 and 20 Township 27 North Range 33 West in Newton County, on the west by the State line between
Missouri and Kansas, and on the east by the range line between Ranges 31 and 32 West.  The Site
encompasses several small- to medium-size municipalities and the surrounding unincorporated areas.  Land
use varies from agricultural to urban.  Approximately 60,000 people live within the Site boundaries, and
the EPA has identified that at least 650 residential homes utilize shallow ground water wells for
drinking water supplies within the Site.  Most of these homes are located in the unincorporated areas of
the Site, and most are located in the Oronogo/Duenweg Designated Area east of Joplin, Missouri.



2 . 0    Site History and Enforcement Activities

       The EPA added the Site to the National Priorities List (NPL)  in 1990.  The NPL is the EPA's list
of sites which have the greatest contamination and pose the greatest threat to human health and the
environment.  The Site has been divided into 11 separate designated areas (Das) for investigation because
of its large area, about 270 sguare miles.  EPA conducted a potentially responsible party  (PRP) search to
identify mining companies that may be responsible for cleanup of the wastes and contamination at the
Site.  In 1991, the EPA signed an  Administrative Order on Consent with a group of nine PRPs to conduct a
Remedial Investigation/Feasibility Study  (RI/FS) at seven of the DAs of the Site under EPA oversight.
EPA conducted the investigations at the remaining four DAs.  Results of the investigations indicated that
some residents utilizing private shallow water wells for their drinking water supply were consuming water
exceeding health-based standards for cadmium, lead, zinc, and manganese.

       In December 1993, EPA issued a Unilateral Administrative Order (UAO)  to the  PRPs to supply bottled
water to affected homes.  In June 1994, EPA issued a second UAO to the PRPs to conduct if wells were
found to exceed heath-based standards.  These investigations identified approximately 100 affected homes.
Approximately 60 affected homes are currently being supplied bottled water by the PRPs, and EPA supplies
bottled water to approximately 40 homes.

3. 0    Highlights of Community Participation

EPA issued a Proposed Plan to address ground water contamination on March 16, 1998.  A 30-day public
review and comment period was held from March 16 to April 17, 1998.   A public meeting was held on March
24, 1998, at Missouri Southern State College in Joplin, Missouri, to present the Proposed Plan and
solicit comments from the public.  Additionally, EPA established an Administrative Record which contains
supportive documents for this decision.  The Administrative Record is available for review during normal
business hours at the following locations:

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       1.01   Joplin Public Library
              300 Main
              Joplin,  Missouri

       1.02   Webb City Public Library
              101 South Liberty
              Webb City,  Missouri
3.      Carl Junction City Hall
       105 North Main
       Carl Junction,  Missouri

4.      U.  S.  Environmental Protection
       Agency
       Region VII Docket Room
       726 Minnesota Avenue
       Kansas City,  Kansas
       The Proposed Plan presented to the public provided that EPA would support Public Water Supply
District  (PWSD) #3 and would provide point-of-use treatment units to all other affected homes outside of
PWSD #3.  The community's preferences are an extremely important factor and help determine the final
decision to address ground water contamination.  The comments received from the public during the comment
period and the public meeting indicated the community is not in favor of the point-of-use treatment
units,  and prefers public water supplies for all affected and threatened homes.  Therefore,  EPA has
modified its decision from that presented in the Proposed Plan to include extension of existing public
water supply lines, where practical and cost effective,  to eliminate the need for as many point-of-use
treatment units as possible.  Included in this ROD is a responsiveness summary that responds to
significant comments the EPA received from the public during the comment period.

4.0    Scope and Role of Operable Unit

       As discussed above,  EPA listed the site on the NPL in 1990.   The site was called the
Oronogo/Duenweg Mining Belt Site.  The Jasper County Site is one of the higher priority sites on the NPL
because of the human health risks from exposure to contaminated ground water and surface mining wastes.
Due to the large geographic area, EPA divided the Site into 11 separate DAs, which include Snap,
Neck/Alba, Thorns, Joplin, Oronogo/Duenweg, Carl Junction, Klondike, Iron Gates, Iron Gates Extension,
Belleville, and Waco.  In addition, EPA divided the Site into four separate Operable Units (OUs) for
clean up activities because contamination was present in more include OU-01, Mining and Milling Waste;
OU-02,  Smelter Waste Residential Yards; OU-03, Mine Waste Residential Yards; and OU-04, Ground Water.

       This ROD for OU-04,  Ground Water,  is consistent with EPA's decisions for this Site as well as
future actions under consideration.  One of the first actions undertaken in 1993 was to provide bottled
drinking water to residents at risk from exposure to contaminated drinking water. EPA determined that
this exposure route was a significant human health risk for this site.  One of the purposes  of this ROD
is to replace the bottled water program with a more permanent water supply.  In 1996, EPA issued a ROD
for two OUs, the Smelter Waste and Mine Waste Residential Yards  (OU-02 and OU-03).   Cleanup  of
contaminated residential soils became a priority in 1994 based on the Missouri Department of Health
(MDOH)  exposure study of the site. MDOH determined one of the most significant human health  risks was
exposure to contaminated soils.  EPA expects the residential yard soil cleanup to be complete in 2002.
The final ROD will address the mining and milling waste, OU-01, and is expected to be issued in 1999.
The OU-1 ROD will address ecological risks at the Site created by mining wastes and surface  water and may
include limited ground water remediation at discrete locations to address the ecological risks created
where ground water discharges or contributes to surface water contamination.

       The action for contaminated ground water,  as addressed by this ROD,  is necessary to mitigate the
principal threat for OU-04, which is the risk from human consumption of contaminated ground  water.  The
main component is to provide alternate drinking water supplies to residents who are not currently
supplied with a public water supply system.  Alternate water supplies include hook ups to existing public
water supply districts and installing point-of-use treatment units.  Other components of the selected
alternative include institutional controls to protect future residents from installing shallow ground
water wells for drinking water and to monitor homes that have threatened shallow ground water wells due
to seasonal variation in water guality.  This ROD will terminate the existing bottled water  program that
serves about 100 homes, who will be provided alternate water supplies.

       The bottled water program began during the remedial investigation (RI).   A group of nine PRPs
conducted the RI with EPA oversight in accordance with an Administrative Order on Consent issued in 1991
at seven of the DAs, while EPA conducted the RI at four DAs.  EPA identified residents who drank ground
water from the shallow aguifer and determined that some people were drinking contaminated water.  These
homes were found in the Oronogo/Duenweg,  Neck/Alba and Iron Gates Extension DAs.  Samples from these
residential wells showed cadmium, lead, zinc and manganese at concentrations exceeding acceptable levels
established by the Safe Drinking Water Act (SDWA) .   EPA issued two UAOs, in 1993 and 1994 that reguired
the PRPs to supply bottled water to homes with samples showing contaminated drinking water.  In addition,
the PRPs were reguired to locate other potentially affected homes in the Oronogo/Duenweg  (0/D) and

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Neck/Alba DAs.  The PRPs identified areas around the Das known to be hydraulically down gradient from
mining areas, reviewed public water supply areas, and located areas known to rely on private wells for
water supply.  The EPA also reguired that the PRP's investigate areas believed to be hydraulically up
gradient of the 0/D DA and to confirm ground water flow directions and hydrologic divides at the site.
Two additional sampling efforts followed the initial drinking water evaluation as the study area was
expanded around the 0/D DA to include potentially hydrologically connected areas.  Figure 2 depicts the
expanded boundaries of the 0/D DA covered by these investigations.  If additional contaminated wells are
found outside the DA boundaries, the boundaries will be further expanded.  The expanded boundaries are
included whenever EPA refers to the 0/D DA in this ROD.

       The ground water sampling activities at the Iron Gates Extension  (IGE)  DA were conducted in March
1995 by the EPA.  Seven households in IGE were found to be using water with metal concentrations above
cadmium action levels established under the SDWA.  These households were provided bottled water by the
EPA.

       EPA and the PRPs evaluated the use of water softeners during the extensive sampling efforts in
1993 and 1994.  Water treated with in-home water softeners was sampled before and after the softener.
EPA determined that the water softeners effectively reduce contaminant concentrations to levels below the
established acceptable levels under the SDWA.  Thus, bottled water was not provided to homes with water
softeners, and subseguent sampling rounds did not include homes with water softeners.

       In all, more than 650 households within and around the Neck/Alba DA,  0/D DA,  and IGE DA were
contacted to reguest permission for sampling between December 1993 and May 1994. Some wells within the
DAs were not sampled because the residents or owner denied permission to sample wells, water softeners
were in use, or no response was received from the residents or owners after two attempts to make contact.
Approximately 100 homes that were identified during the investigations as using shallow ground water
wells with samples that exceeded the Maximum Contaminant Levels (MCLs) or action levels under the SDWA,
have been provided bottled water.

5. 0    Summary of Site Characteristics

       Ground water within the Site occurs in two aguifers,  the shallow aguifer and the deep aguifer,
which are separated throughout the region by a confining layer of relatively impermeable rock.  The
shallow aguifer is comprised primarily of Mississippian Age limestone formations and averages
approximately 300 feet in thickness, ranging to a maximum thickness of approximately 400 feet.  The
confining layer separating the shallow and deep aguifers averages approximately 400 feet in thickness and
is composed of Mississippi and Devonian Age shales.  The deep aguifer is composed of Cambrian and
Ordovician Age sandstone and dolomite formations and ranges up to 850 feet thick and is a confined
aguifer overlain and underlain by relatively impermeable materials.

       Water yields in the shallow aguifer are highly variable and, on a site-wide basis,  are
predominantly dependent on secondary permeability features within the rock formations. Secondary
permeability results from solution enlargement along bedding planes or fractures and has also been
created in areas of extensive interconnected mine workings or mine collapse. Mining at the site generally
occurred above and within the shallow aguifer.  Most water production from the shallow aguifer, up to
several hundred gallons per minute  (gpm), occurs in areas where secondary permeability is present.
Without the secondary permeability, water yield is very low.  Recharge of the shallow aguifer occurs
through infiltration of precipitation on the surface through permeable rock layers.   Recharge is greatest
in mined areas and areas with large amounts of secondary permeability, and is fairly rapid as
precipitation infiltrates guickly and is transmitted along underground openings.

       Shallow aguifer ground water at the Site is generally neutral to alkaline with a pH ranging from
6.2 to 8.0.  Table 1 summarizes the ranges of concentrations of selected metals found in shallow aguifer
ground water during the Jasper County RI.  These metals are subject to regulation in public water
supplies.  Table 1 also shows the MCL acceptable for public drinking water supplies in accordance with
the SDWA.  Average concentrations of these contaminants in shallow aguifer wells at the Site ranged from
approximately 1.5 times to 10 times greater than corresponding concentrations in wells located outside
the mined areas.  In addition, average  concentrations exceeded the acceptable levels under the SDWA for
cadmium, lead and zinc.

       Shallow aguifer ground water is used as a source of drinking water in those areas of the Site
without access to public supplies.  Shallow aguifer ground water is also used in western Jasper County
for watering livestock and gardens, and for industrial purposes, and may, in a few instances, be used for
consumption where residents chose not to hook up to available public water supplies.

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       Sources of contamination in the shallow aquifer are the exposed ore surfaces within the inactive
mining operations.  Mining exacerbated any contamination from natural mineralization by increasing the
extent of contamination through infiltration of highly oxygenated water that mobilizes residual metal
bearing minerals.  Precipitation on huge volumes of surface mining wastes also mobilizes contaminants
which may enter the shallow aguifer.  Approximately, nine million tons of on-site surface mining wastes
contribute to the ground water pollution problem.

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its water supply from surface water sources (Shoal Creek).  Also, approximately 1,800 rural households in
the area receive water from the deep aquifer through public water supplies wells.

6.0    Summary of Site Risks

       In general,  EPA has determined that the principal threat for this OU is the human health risk from
ingestion of ground water contaminated with metals from mining and milling sources. These determinations
are based on the analysis in the risk assessment and data collected during the remedial investigation.
The contaminants of concern in the ground water include lead, cadmium, and other heavy metals.  EPA has
determined that the actual or threatened release of hazardous substances, such as lead, cadmium,
manganese, nickel,  and zinc, may present an imminent and substantial endangerment to public health,
welfare, or the environment if not addressed by implementing the Selected Remedy.

       The remedial objective of this ROD,  therefore,  is to prevent the identified, unacceptable human
health risks due to ingestion of or exposure to site-related contaminants in ground water. This ROD does
not distinguish between shallow and deep aguifer ground water as to its purpose. The objective is to
prevent or reduce potential ground water-related human health risks irrespective of which aguifer
residents may be using for water supplies.

       The risk assessment methodology and results are briefly described below.   EPA encourages the
reader to review the Risk Assessment Report and the RI Report in the Administrative Record.

6.1    Methodology

       In 1995, the MDOH conducted a baseline  risk assessment for the Site under a cooperative agreement
with the EPA.  The assessment examined risks related to human exposure to metals in various media,
including the ingestion of metals in drinking water.  Since most residents at the Site who consumed
ground water obtained their drinking water from municipal water systems drawing water from the deep
aguifer, deep aguifer ground water was evaluated in the risk assessment as a drinking water source.
Ingestion of shallow aguifer water was not addressed because residents found to be consuming water
containing metals above risk-based action levels have been supplied with bottled water.  It was assumed,
for the purposes of the risk assessment that Site residents showered or bathed in shallow aguifer ground
water, and thus, were potentially exposed to metals via dermal absorption.

       Results for 21 samples of deep aguifer  ground water were used to characterize the drinking water
source.  The drinking water samples contain very low concentrations of cadmium,  copper, lead, manganese,
nickel, and zinc; these metals were identified as contaminants of concern (COCs) in deep aguifer drinking
water.  For the shallow aguifer, the COG list also included arsenic.  As a result of the extensive RI and
two subsequent sampling efforts, 553 samples were aquifer groundwater.  Concentrations of most COCs were
higher in the shallow aquifer samples, compared to levels in the deep aquifer, as shown above in Table 1.

       The available data regarding COG concentrations in ground water were used in conjunction with the
results of a demographic study conducted as part of the RI investigation to obtain ambient temperatures,
inhalation during showering was not considered to be a complete exposure pathway.  Also, since most
metals are not readily absorbed through the skin, the evaluation of the dermal exposure pathway was
limited to two COCs, cadmium and arsenic.

       In the risk characterization,  exposure  and metals toxicity were summarized and integrated into
quantitative and qualitative expressions of risk.  Estimated metal intakes were compared to toxicity
values in order to characterize noncarcinogenic effects.  For estimating carcinogenic effects, estimated
intakes and chemical-specific dose-response data were used to calculate the probabilities of an
individual developing cancer over a lifetime.   Exposures to lead were assessed separately, through the
use of EPA's Integrated Exposure Uptake Biokinetic Model  (IEUBK). The IEUBK model was designed to model
exposure from lead in air, water, soil, dust,  diet, and other sources with pharmacokinetic modeling to
predict blood lead levels in children six months to seven years old.

       Noncancer hazard quotients were calculated for the ingestion and dermal absorption pathways.
Hazard quotients for each pathway were summed to give a pathway hazard index, and pathway hazard indices
were summed in a Total Hazard Index.   According to the "Risk Assessment Guide for Superfund," human
health risks may exist when the Total Hazard Index exceeds 1.0.

6.2 Results:  Shallow Aquifer Risks

       The noncarcinogenic hazard indices for  dermal absorption of cadmium and arsenic in shallow aquifer
water were negligible for all adult and child scenarios evaluated.  An analogous series of calculations
were made for dermal exposure to arsenic, a carcinogen, to estimate a Total Excess Lifetime Cancer Risk.
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The Total Excess Lifetime Cancer Risk estimated for the dermal absorption of arsenic was low, with a
maximum of 2.3x10 -7 (adults), which is less than the 1X10 -6 (one in a million)  point of departure
identified in the NCP for consideration of remedial action. Dermal absorption of lead is not an input in
the model because lead is not readily absorbed through the skin.  In summary, the risk assessment did not
identify significant risks associated with dermal exposure to water from the shallow aguifer.

The shallow aguifer contains average concentrations of some contaminants of concern that exceed the
acceptable drinking water levels, e.g., lead, cadmium, manganese, and nickel identified under the SDWA
(see Table 1).  These contaminants are hazardous substances.  The SDWA action levels, or MCLs, are
health-based criteria established for public water supply systems based on toxicological studies.  The
risk assessment assumed that consumption of shallow aguifer ground water that exceeds the primary MCLs or
the lead action level presents unacceptable human health risks.

6. 3    Results:   Deep Aquifer Risks

       The pathway hazard index for ingestion of five noncarcinogenic metals in deep aguifer drinking
water ranged from 0.08 to 0.2 for adults under reasonable maximum and average exposure scenarios.  For
children, the pathway hazard for all scenarios ranged from 0.13 to 0.46. These hazard indices, which are
significantly less than 1.0, indicate that noncarcinogenic risk for ingestion of drinking water from the
deep aguifer is low.  Carcinogenic risk through exposure to arsenic in drinking water was not evaluated
because arsenic was not detected in deep aguifer ground water RI sampling activities and is not
considered a contaminant of concern.

       The results of the IEUBK predictive blood lead modeling indicated that ingestion of drinking water
from the deep aguifer by children was a minor pathway of lead exposure, accounting for only about four
percent of total lead uptake.  Dermal absorption of lead is not an input in the model because lead is not
readily absorbed through the skin.

6. 4    Ecological Risk

       An ecological risk assessment is currently being conducted for the Site,  and is expected to be
finalized in the near future.  The investgations conducted to date indicate that contaminated ground
water contributes significant risk to the ecosystems at the Site through discharge to surface water.
This ROD deals specifically with the human health risk from exposure to contaminated ground water.  All
ecological risks identified at the Site will be addressed in a subseguent ROD for the mining wastes
(OU 1) .

7.0    Remedial Action Objectives

       Remedial Action Objectives (RAOs)  are specific goals for preventing excessive risks and protecting
human health.  The ground water RAOs presented in this section reflect the current understanding of site
conditions and potential exposure pathways based on site characterization data and Human Health Risk
Assessment findings.  Specifically, ground water RAOs for the Jasper County Site are developed to address
current and future potential human health risk from exceedances of risk-based action levels in public and
private domestic water wells.  A future ROD may contain limited specific ground water remedial actions to
address localized ground water contributions to the ecological risk.

       As set forth by the National Contingency Plan (NCP), the threshold determination of whether
remedial action is reguired at CERCLA sites is based on the presence of unacceptable risks.  The
risk-based action levels used to make the determination of unacceptable risk for the Ground Water OU at
the Jasper County Site consist of the federal primary MCL for cadmium and the SDWA action level for lead.
For purposes of this ROD, potential risks to human health are assumed to be unacceptable when the
following conditions exist within the DAs of the Site:

       •      Statutory,  risk-based action levels are exceeded in current or future domestic water
              supplies.

       •      Domestic  water supplies are threatened with exceeding action levels by the migration of
              contaminants in site ground water.

       Based on results of ground water surveys conducted during the RI, one RAO is deemed adeguate to
address potential, ground water related human health risks at the Jasper County Site. The sole RAO for
the Ground Water OU is as follows:

       •      Prevent unacceptable human health risks due to ingestion of or exposure to site-related
              contaminants in ground water.
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       This RAO is not intended to distinguish between shallow and deep aquifer ground water.  The intent
of the RAO is to establish an objective to prevent or reduce all potential ground water related human
health risks irrespective of which aquifer residents may be using for domestic water supplies.

8. 0    Description of Alternatives Evaluated

EPA developed and evaluated five alternatives during the feasibility study (FS).   Each alternative
addresses the provision of alternate water supplies for homes using drinking water from threatened or
contaminated private shallow water wells.  Treatment, containment, and other physical controls to
remediate the ground water were not fully developed and evaluated.  During the initial screening of
technologies, EPA determined that design of a treatment or containment system for the contaminated
aquifer would be nearly impossible because the contamination is widespread and the aquifer unit is
characterized by numerous fractures and openings.  Additional discussion on the technical
impracticability of ground water remediation is provided in Attachment 1 of this ROD.

       The No Action alternative,  also was evaluated, however,  EPA believes that the No Action
alternative is not protective of human health and does not consider it a viable option.  The No Action
alternative and the four action alternatives are described in Table 2.  Alternatives 1, 3, 4,  and 7 are
easily implementable and could be completed within one year.  Alternative 6,  as presented in the FS,
would be difficult to implement since it would require establishing new rural water districts and
annexing land into various municipalities.  It is estimated that Alternative 6 would require three to six
years to complete.

       In response to comments received from the public,  EPA developed and evaluated a modified version
of Alternative 6, called Alternative 6A, which is the Selected Remedy in this ROD.  In general,
Alternative 6A modifies Alternative 6 by including additional homes for the public supply systems and
reducing the number of homes that receive point-of-use treatment systems.  Section 10 contains a complete
description of the Selected Remedy.  Alternative 6A is included in this summary to complete the
comparative analysis.

       In general, the major applicable, relevant and appropriate requirements (ARARs)  for clean up of
contaminated ground water at this site are the federal and state drinking water standards under the SDWA.
These ARARs are associated with each of the six clean up alternatives EPA evaluated in detail.
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No.
Alternative
   Name
                 Table 2
         Alternative Descriptions
Alternative Assumptions and Descriptions
Alternative
   Cost**
        No Action
        Bottled Water
        Plus
        Institutional
        Controls and
        Monitoring
        Point-of-Use
        Treatment
        Systems Plus
        Institutional
        Controls and
        Monitoring
                   *  The current bottled water program would be discontinued.                    None
                   *  No other actions would be implemented.

                   *  The current bottled water program in the expanded 0/D,  Neck              $507,193
                   /Alba, and IGE DAs would be continued until the plans are
                   implemented and needed infrastructure is available to provide public
                   water to affected households.  It is assumed that public water
                   supplies will become available throughout the DAs within 10  years,
                   except in the newly created PWSD No. 3, where public water
                   supplies are expected to be provided within 1 year,  and the  Joplin
                   annexation area, where public water supplies are expected to be
                   provided within 5 years.
                   *  Drilling new shallow domestic water wells would be restricted in
                   affected areas of the site through a program of institutional controls.
                   *  An institutional control would be implemented to ensure the
                   continued high guality of deep aguifer ground water into the future.
                   This institutional control would consist of enforcing the aguifer
                   protection provisions of the existing Missouri Well Driller's Law
                   ensuring proper casing depth, casing integrity, and proper
                   abandonment of any existing or new water supply wells.
                   *  The shallow well monitoring program would be implemented  to
                   evaluate threatened domestic wells subject to seasonal variations in
                   water guality.  An attempt would be made to sample all households
                   with existing water softeners, which previously denied access, or did
                   not respond.  Those households with exceedances of risk-based
                   action levels would be provided bottled water until a public water
                   supply becomes readily available.

                   *  Point-of-use treatment systems such as water softeners or RO units         $533,444
                   would be installed in all affected households, except for those
                   households within the boundaries of the newly formed PWSD No. 3.
                   *  Households within the boundaries of PWSD No. 3 would be
                   provided with bottled water until the district's infrastructure is
                   constructed and water supplies become available.
                   *  This alternative assumes that public water supplies will  become
                   available throughout the DAs within 10 years, except in the  newly
                   created PWSD No. 3, where public water supplies are expected to
                   be provided within 1 year, and the Joplin annexation area, where
                   public water supplies are expected to be provided in 5 years.
                   The same institutional controls, monitoring program, and remedial
                   design phase sampling program implemented under Alternative  3
                   would also be implemented; however, the monitoring program for
                   Alternative 4 would include confirmatory sampling, of the point-of-
                   use treatment systems to verify that risk reduction goals are met.
                   Households with exceedances identified in the remedial design phase
                   sampling program would be included in the remedial action.
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No.
Alternative
  Name
Alternative Assumptions and Descriptions
Alternative
   Cost **
        Public Water
        Supplies for
        All
        Households
        with
        Exceedances
        Plus
        Institutional
        Controls and
        Monitoring
                  *  Affected households in the site would be provided with public
                  water supplies through construction of public water supply
                  distribution systems.
                  *  The current bottled water program would continue throughout the
                  areas until the plans are implemented and needed infrastructure is
                  constructed.  It is assumed public water supplies could be
                  constructed within 5 years.
                  *  The same institutional controls, monitoring program, and remedial
                  design phase sampling program implemented under Alternative 3
                  would also be implemented.  Households with exceedances
                  identified in the remedial design phase sampling program would be
                  included in the remedial action.
                                                                   $1,436,403
 6A     Public Water
        Supplies for
        Affected and
        Threatened
        Households
        and Point-of-
        Use
        Treatment
        Units for
        Remote
        Households
        Plus
        Institutional
        Controls and
        Monitoring

 7      Public Water
        Supply
        District No. 3
        Plus Point-of-
        Use
        Treatment
        Systems,
        Institutional
        Controls,
        Monitoring
                  *  Both affected and threatened households in the site would be
                  provided with public water supplies through construction of public
                  water supply distribution systems.
                  *  Affected households in the site to remote to be provided with
                  public water supplies would receive point-of-use treatment units.
                  *  The current bottled water program would continue throughout the
                  areas until the plans are implemented and needed infrastructure is
                  constructed.  It is assumed public water supplies could be
                  constructed within 1 to 2 years.
                  *  The same institutional controls, type of monitoring program, and
                  remedial design phase sampling program implemented under
                  Alternative 3 would also be implemented.  Households with
                  exceedances identified in the remedial design phase sampling
                  program would be included in the remedial action.
                  *  Public water supplies would be made available to all households in
                  the 0/D DA that are located within the expanded service area of
                  PWSD No. 3 through the remedial action.  Affected households that
                  are not located within the expanded PWSD No. 3 service area would
                  be provided with point-of-use treatment systems.
                  *  Households within PWSD No.3 service area that are currently
                  receiving bottled water would be provided with bottled water until
                  the district's infrastructure is constructed and water supplies become
                  and avai1able.
                  *  The same institutional controls, monitoring program, and remedial
                  design phase sampling program implemented under Alternative 4
                  would also be implemented under Alternative 7, although the
                  number households to be monitored would be different from the
                  other alternatives.  Households identified as affected during the
                  design phase sampling program would be included in the remedial
                  action.
                                                                   $2,711,736
                                                                   $1,236,857
    Costs include present worth of capital cost,  operation and maintenance,  monitoring,  and remedial design sampling.
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9.0    Summary of the Comparative Analysis of Alternatives and Rational for The Selected Alternative

       The NCP,  40 C.F.R. Section 300,  requires EPA to evaluate remedial alternatives against nine
criteria to determine which alternative is preferred for clean up.  EPA performs this analysis during the
FS.   The detailed analysis in the FS Report provides an in-depth analysis of the five alternatives
compared against the nine criteria.  An alternative must satisfy all nine criteria before it can be
selected.  The first step to meet is the threshold criteria, which are overall protection of public
health and the environment and compliance with ARARs.   In general, alternatives that do not satisfy these
two criteria are rejected.

       The second step is to compare the alternatives  against a set of balancing criteria.   The NCP
establishes five balancing criteria which include long-term effectiveness and permanence; reduction in
toxicity, mobility, or volume achieved through treatment; implementability; short- term effectiveness;
and cost.  The third and final step is to evaluate the alternatives on the basis of modifying criteria,
which are state and community acceptance.  EPA has received significant public comment on the plan for
remedial action we proposed in March 1998.  On the basis of the comments received.  EPA developed
Alternative 6A and it is included in this summary.

       EPA has determined that Alternative 6A is the alternative that best achieves the nine criteria.
The FS, the detailed analysis of alternatives, and the comments from the public support this decision.
The following briefly summarizes the rationale for the selected alternative by profiling the alternatives
against the nine criteria and highlighting how the selected alternative compares to the others.

9.1    Threshold Criteria

       The following presents a brief description of how the alternatives satisfy the threshold criteria
of overall protection of public health and the environment and compliance with ARARs.

9.1.1  Overall Protection of Human Health and the Environment

       This criterion provides an overall assessment of whether an alternative meets the requirement that
it is protective of human health and the environment.   The overall assessment of protection is based on a
composite of factors from other criteria, especially long-term effectiveness and permanence, short-term
effectiveness, and compliance with ARARs.

       Alternatives 3,  4, 6 and 7 in the FS Report and EPA's Alternative 6A will protect human health and
the environment to varying degrees.  However, Alternative 1, the No Action usefulness as a baseline
alternative.

       To protect human health and the environment,  Alternative 4, Treatment Units relies on long-term
monitoring of threatened private drinking water wells.  Alternatives 6, 6A, and 7, have public water
systems that do not need to monitor private drinking water wells.  Under Alternative 4, exposure to
contaminants may occur between sampling events or monitoring may fail to detect occasional exceedances
due to fluctuating metal concentrations.  Residents with threatened wells that are connected to a public
water supply system would not be subjected to this potential exposure scenario.  In addition,
Alternatives 6,  6A, and 7 include water line connection fees, not included in Alternative 4.  Connection
fees funded as part of the remedy would assure more people will be connected to a public water supply
system which will permanently reduce risk. Alternative 4 relies on affected residents to pay the
connection fee when, and if, it becomes available in the future.

       Alternative 3,  Bottled Water, is only moderately protective of human health because bottled water
use cannot be assured,  readily monitored or controlled.  Under Alternative 3, untreated shallow ground
water remains readily available for consumption in homes receiving bottled water.  There would be no
means of ensuring the bottled water is being used as intended. Alternatives 4, 6, 6A, and 7 are
protective of human health because household water would be treated with point-of-use treatment units or
supplied through a public water distribution system, thereby ensuring treated water is available.  Some
households may elect not to use public water supplies due to the monthly water bill under Alternatives 6,
6A,  and 7.  Also, some households may elect not to use the point-of-use treatment units.

       The point-of-use treatment systems prescribed under Alternatives 4 and 7 could be installed in
less than six months.  The public water supply components of Alternative 6A and 7 are expected to start
providing public water within six months to a year.   Alternative 6 would gradually decrease the number of
homes where untreated tap water is available over a three-year period.  Alternative 6A would provide
permanent protection to the most residents in the shortest amount of time.  Alternative 6A provides a
permanent public water supply that assures protection of human health because suppliers will be subject
to the requirements of the Safe Drinking Water Act,  which safeguards public water supplies in the United
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States.

       Through design-phase sampling and monitoring programs,  all the alternatives address the
possibility that there may yet be some unidentified homes using shallow ground water with unacceptable
levels of contaminants.  However, the number of unidentified affected wells will be reduced under
Alternative 6A because most households, whether affected, potentially unidentified affected, or
unaffected but threatened, within the PWSD No. 3 expanded service area and within the area of extended
water lines from the Missouri American Water Company will be supplied with public water.

       The institutional controls prescribed under all the retained alternatives would provide effective
protection for future residents and are considered readily implementable.

9.1.2 Compliance With ARARs

       This criterion is used to decide how each alternative meets federal and state ARARs,  as defined in
CERCLA Section 121.  Compliance is judged with respect to chemical-specific, action-specific, and
location-specific ARARs as well as appropriate criteria,  advisories and guidance.  A list of ARARs
identified for each alternative is in the FS Report.

       None of the alternatives under consideration provide for cleanup of the ground water aguifer to
drinking water standards because aguifer remediation is considered technically impracticable.  Thus, none
of the candidate alternatives can comply with the chemical-specific ARARs.  A technical impracticability
waiver of chemical-specific ARARs is necessary to select a remedy for active clean up of the ground water
at this Site.  Attachment 1 provides a detailed discussion of the technical impracticability of
remediating the ground water.  The justification for a waiver would be based on the technical
complications at the site that make ground water clean up impractical, such as karst topography,
heterogeneity of the shallow aguifer formation, the large areas of secondary permeability features
including the solution enlargement along bedding planes,  fractures, and collapse of rock formation.  In
addition, extensive interconnected mine workings that occur generally above and within the shallow
aguifer, the nature and extent of contamination, and other factors also contribute to the
impracticability of ground water cleanup to meet ARARs.  Although the availability of alternate water
supplies by a public system or by individual home water treatment systems, as described in Alternatives
4, 6, 6A, and 7, would provide adeguate drinking water to the affected residents at this Site, the
availability of such alternate water supplies does not obviate the need for a waiver of chemical-specific
ARARs.

       No location- or action-specific ARARs were identified for Alternative 3 and 4.  Compliance  with
location- and action-specific ARARs would have to be addressed during remedial design of Alternatives 6,
6A, and 7 which reguire construction of public water systems. However, no remedial design problems
resulting in noncompliance are anticipated.

9.2    Balancing Criteria

       The following presents a brief description of how the alternatives developed in the FS satisfy the
balancing criteria.

9.2.1 Long-Term Effectiveness

       This criterion addresses the results of a clean up action in terms of the risk remaining at the
Site after the goals of the clean up have been met.  The primary focus of this evaluation is to determine
the extent and effectiveness of the controls that may be reguired to manage the risk posed by treatment
residuals and/or untreated wastes.

       Assuming appropriate institutional controls are implemented and enforced and households with water
known to exceed action levels participate in the prescribed drinking water programs, potential human
health risks would be reduced to approximately eguivalent levels under Alternatives 4, 6, 6A, and 7.

       Under Alternatives 4,  6, 6A,  and 7 water used by a household would be treated.  Therefore,  these
alternatives would be reliable in preventing ingestion of site-related contaminants.  However, the
long-term reliability of the water treatment units reguire that they be monitored and replaced
periodically.  Under Alternatives 4 and 7, reverse osmosis  (RO) units would treat only the water at the
taps where they are installed, which allows the consumption of untreated shallow ground water from other
untreated taps in the home.  Alternative 3 reguires bottled water for drinking and cooking; however, the
water at the tap would still exceed action levels and could be consumed by residents for whom bottled
water is an inconvenience.
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       Providing treated water through public water distribution systems under Alternatives 6,  6A,  and 7
is a highly permanent remedy.  A public water system's infrastructure is expected to provide adeguate
water indefinitely.  The effectiveness and reliability of the point-of-use systems under Alternatives 4
and 7 would be monitored to ensure compliance with drinking water standards.  Also, under Alternatives 3,
4, and 7, it is assumed that all households within the affected areas of the site will have access to a
public water supply within a 10-year period.

       None of the alternatives propose ground water treatment to address water guality in the aguifer.
Therefore, none of the alternatives would reduce the volume or concentrations of site-related
contaminants in the aguifer.  Alternatives 3, 4, 6, 6A, and 7 all rely on implementing institutional
controls and monitoring to address residual risks associated with leaving contaminants in the shallow
aguifer.

9.2.2 Short-Term Effectiveness

       This criterion addresses the effects of the alternative during the construction until the clean up
is completed and the selected level of protection has been achieved.

       All households in the site known to be using shallow aguifer water exceeding risk-based action
levels are receiving bottled water.  Alternative 3 has been implemented except for the prescribed
monitoring and institutional controls programs.  Alternatives 4, 6A, and 7 can be implemented within six
months to two years.  Alternative 6 would reguire approximately three years to fully implement.  During
the implementation period for Alternatives 4, 6, 6A, and 7, the bottled water program would continue.
Alternatives 4 and 7 provide the greatest degree of protection during the implementation phase because,
for most homes, the entire water supplies of affected households can be treated within a relative short
time frame.  Alternative 6A could be implemented within one or two years.  Reliance on bottled water
during the longer implementation phase of Alternative 6 and 6A exposes those residents to potential risks
unless they continue to use bottled water exclusively.

9.2.3 Reduction of Toxicitv, Mobility, or Volume

       This criterion addresses the statutory preference for selecting remedial actions that employ
treatment technologies that permanently and significantly reduce toxicity, mobility or volume of the
contaminants.

       None of the alternatives provide for ground water treatment as a means to reduce the volume or
concentrations of site-related contaminants in the aguifer.  Treatment of the contamination in the
aguifer is considered technically impracticable.

9.2.4 Implementabilitv

       This criterion addresses the technical and administrative feasibility of implementing a cleanup
and the availability of various services and materials reguired during its implementation. All the
alternatives are readily implementable.  The technical aspects of providing alternative water supplies or
point-of-use treatment are implementable under all alternatives.  Alternative 6 will reguire planning,
remedial designs, and various civil construction projects.  In contrast, the design and planning of the
PWSD under Alternative 6A and 7 is mostly completed.  Alternative 6A will reguire design of the extended
existing public water lines, but considered readily implementable.  Alternatives 3 and 4, providing
bottled water or water softeners, reguire little in the way of design or construction.

       Providing public water supplies under Alternatives 6 is expected to be administratively
implementable but difficult.  Establishing new rural water districts represents a significant
administrative undertaking.

       The monitoring programs and institutional controls prescribed under Alternatives 3, 4,  6,  6A,  and
7 are expected to be readily implementable.

9.2.5  Cost Effectiveness

       This criterion addresses the direct and indirect capital cost of the remedy.  Operation and
maintenance costs incurred over the life of the project, as well as present worth costs, are also
evaluated.

       Of the  alternatives under consideration, Alternative 4 is a cost-effective remedy because it
addresses all current and future human health concerns while meeting ARARs at a low cost. However,
Alternative 4 is not very effective in the long term because of the need to monitor and replace the
point-of-use treatment units.  At $2.7 million, the estimated cost of Alternative 6A is the highest of
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all the alternatives evaluated.  In addition, the increase in reliability and permanence with Alternative
6A make it cost-effective.  The cost of Alternative 6, at $1.4 million and Alternative 7 at $1.2 million
would be lower.  The costs of Alternatives 3 and 4 are estimated at approximately $507,193 and $533,444,
respectively.

9.3    Modifying Criteria

       The following presents a brief description of how the alternatives developed in the FS satisfy the
modifying criteria.

9.3.1  State Acceptance

       This criteria addresses MDNR's preferences or concerns about the Site remedial action
alternatives.  The EPA is the lead Agency and has coordinated all Site activities with MDNR throughout
this project.  MDNR concurred on the Proposed Plan issued by EPA in March 1998,  which proposed
Alternative 7.  However, subseguent to receiving comments from the public on the Proposed Plan and new
information concerning existing water lines in the affected areas of the 0/D and IGE DAs, MDNR has
expressed to EPA its preference for less water softeners and more public water supply hookups.  MDNR has
indicated that Alternative 6A is their preferred selection for the ground water remedy at the Site.

9.3.2  Community Acceptance

       This criteria reflects EPA's perception of the community's preferences or concerns about the
selected alternative.  The degree of community acceptance of the Preferred Alternative was assessed by
EPA in its review of comments received on the Proposed Plan.  EPA determined that the public prefers
hookups to public water supplies for all affected and threatened homes over point-of-use treatment units.
EPA has very carefully considered the public comments in selecting the remedy for the Site.  With due
regard to community participation,  EPA has determined that Alternative 6A is highly favored among the
affected residents and the community leaders because it is the most permanent and reliable source of
alternate water supply.

10.0   The Selected Remedy

       Based on comments received from the public during the review period,  EPA has selected a modified
version of Alternative 6 as the remedy for ground water at the Site.  The Alternative 6A consists of
several components including:   (1)  implementing the PWSD #3 to provide public water supplies within a
portion of the 0/D DA;  (2) extension of existing of existing public water supplies mains to provide
public water to other affected and threatened households within the 0/D and IGE DAs;  (3) providing a
whole house treatment unit to affected homes within the 0/D, Neck/Alba, or in IGE DAs that cannot cost
effectively be served by public water supplies;  (4) a service contract to maintain the treatment units;
(5) a monitoring program to periodically sample residences in the affected are not currently exceeding
action levels and not hooked up to a public water supply; and (6) institutional controls to protect
future residents from drinking contaminated ground water.

       Alterative 6A differs from Alternative 6,  which provided for public water supply hookups only for
those homes with current exceedances of the action levels and monitoring of the threatened private water
wells.  Alternative 6A provides that the threatened residences,  where economically feasible, will also be
connected to a public water supply.  In addition, Alternative 6 provided for establishing new public
water supply districts.  Alternative 6A relies on the recently formed PWSD #3 and existing water supply
lines from Missouri American Water Company (a private water purveyor in Jasper County) thereby
eliminating the administrative burden of establishing new rural water districts.  A detailed description
of Alternative 6A is summarized below.

10.1   Public Water Supplies

       The affected and threatened homes that will be supplied with public water distribution under the
Alternative 6A are identified on Figures 3 and 4 within the 0/D and IGE DAS. Approximately 176 homes in
the 0/D DA are located within boundaries of PWSD #3 and will be hooked up to the district's water
supplies.  Another 19 homes are located very near the PWSD boundaries and will also be connected to the
district's water mains.  These households are located west and south of the PWSD along Hawthorne Road,
along the main line from Carterville to the PWSD, southwest of the PWSD near Joplin, and south of the
PWSD near Duenweg.  Eight homes are located along the western Webb City City limits and will be connected
to the Webb City public water system.  Additionally, 117 households in the southwestern portion of the
0/D DA and 28 households in the IGE DA will receive public water from expansion of Missouri American
Water Company's existing water supply distribution system.  All together, approximately 348 homes will be
connected to a public water supply.  The location of these homes are also shown on Figures 3 and 4.
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       EPA found from sampling efforts that numerous wells within affected areas had water samples within
acceptable levels for drinking water.  However,  EPA believes these wells are threatened and may exceed
standards in the future or during seasonal fluctuations.  Under Alternative 6A,  households that currently
do not exceed action levels, yet are threatened,  will be hooked up to public water along with the
affected homes.  Making public water supplies available to these households would eliminate the need to
include these households in the long-term monitoring programs prescribed under this alternative.

10.2   Point-of-use Treatment Units

       Approximately 15 homes in the 0/D DA lie  outside the expanded PWSD service area and outside areas
that could be cost effectively connected to Missouri American Water Company mains.  Three of these
households were found to exceed action levels and will be provided with whole house point-of-use water
treatment systems.  One house in Neck/Alba DA and one in the IGE DA will also receive whole house water
treatment systems since they are located at least one mile away from existing water mains.  The total
number of homes receiving point-of-use treatment systems under this alternative will be five.  The
proposed water treatment systems will consist of a sodium chloride charged residential water softener.
EPA found during the sampling events in Jasper County and the remedial actions conducted in Cherokee
County, Kansas, (immediately west of the Jasper County Site) that sodium chloride water softeners are
very effective at reducing metals concentrations in ground water in the Tri-State mining district to safe
levels.  In order to ensure that the point-of-use treatment units are maintained, functioning properly,
and effectively reducing metals concentrations to safe levels, EPA will establish a service contract with
the treatment unit supplier to maintain the units until such time that public water becomes available for
these homes.  When public water supplies are economically available to these households,  EPA will provide
hookups to the public supply.

10.3   Monitoring Program

       Alternative 6A includes a monitoring program to periodically monitor homes with shallow water
wells that are threatened with exceedances but currently have acceptable drinking water levels and will
not be connected to a public water supply system because of their distance form existing water mains.
These residences are generally located in the central and southern portion of the 0/D DA.  All homes
within the affected areas not hooked up to public water or supplied with a treatment unit will be
included in the program.  The program will include households located within existing public water supply
districts not currently hooked up to those systems. The monitoring program for Alternative 6A, as
discussed in Section 8.2, will also include the confirmatory sampling of the newly installed point-of-use
treatment systems.  Confirmatory monitoring of the in-house treatment units is prescribed to evaluate the
effectiveness of the treatment units through sampling at reducing metals concentrations to safe levels.
During the remedial design and planning phase of Alternative 6A, a sampling program will be implemented
to sample homes outside the areas that can cost effectively be connected to public water supplies. The
number of households to receive point-of-use treatment systems will be determined on the basis of these
sampling efforts.




10. 4   Institutional Controls

       The institutional control component of the Preferred Alternative is necessary to reduce the risks
from future use of the shallow aguifer ground water as domestic water supply for new construction or
newly installed wells.  Institutional controls will ensure that new or existing wells  with water samples
exceeding safe drinking water acceptable levels are not used for drinking water without prior treatment.
Institutional controls may include restrictions on the drilling of new shallow aguifer wells under
existing provisions of the Missouri Well Driller's Law, county ordinances governing residential
construction, county well permit restrictions, and public education programs.  A more detailed discussion
of potential institutional controls is presented in Appendix C of the FS.

       Additional  institutional controls under this Alternative will be to prevent future human health
risks due to possible downward migration of site-related contaminants to the deep aguifer from the
shallow aguifer.  Protecting the deep aguifer from future degradation is needed because contaminants
remain in the shallow ground water under Alternative 6A.  Contaminants may migrate to the deep aguifer
through wells that are deteriorate or are not properly plugged when abandoned.  To prevent such
contamination of the deep aguifer water, the Selected Remedy recommends strong enforcement of the aguifer
protection provisions of the existing Missouri Well Driller's Law that ensure proper casing depth, casing
integrity, and proper abandonment of any existing or new water supply wells that reach into the deep
aguifer.
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10.5   Cost

       The cost of Alternative 6A includes the capital costs of constructing part of PWSD #3 to supply to
homes within the 0/D DA served by the district, and extending existing water supply mains form Missouri
American Water Company to other homes in the 0/D and IGE DAS.  These capital costs include furnishing and
installing the water supply mains, lateral distribution lines, and lines and meters needed to connect
individual households.  The estimated capital costs for this alternative also include providing
point-of-use water treatment systems for the households outside the cost-effective reach of public water
supplies.

       The capital cost of this alternative is estimated to be approximately $2,518,988.   Annual O&M
costs for this alternative are assumed to continue for 10 years.  The net present O&M cost would be
$175,137 for ten years at a five percent discount rate.  These O&M costs include provision of bottled
water to affected homes until the selected remedy is implemented, maintenance of the point-of-use
treatment units, monitoring and institutional controls.  Design phase sampling for Alternative 6A is
estimated at $17,611.  The cost estimate for Alternative 6A are presented in Table 3.  For cost purposes,
the estimate was made for eight inch main, although six or eight inch main may be used for connection to
the Missouri American as reguired by the Public Service Commission.

       In the event of public water supply distribution systems are not available in 10 years,  year
service life for the point-of-use treatment units, the net present worth cost to replace the units and
extend the service agreements for an additional 20 years is $2,312 per household.

10.6   Operation and Maintenance

       Operation and maintenance  (O&M)  costs for this alternative include annual service contracts to
maintain the point-of-use treatment systems, administrative costs for program implementation, and any
reguired O&M materials, such as sodium chloride.  The costs of operating and maintaining the public water
supply are assumed to be borne by the customers of the PWSD through their monthly water bills are not
included in the O&M cost estimates for this Alternative 6A.

       Point-of-use treatment systems would be maintained as part of the remedial actions until public
water supplies are available in areas outside the PWSD service area.  Estimated O&M costs are based on
the assumption that the public water supplies will be available within the Joplin annexation area in five
years and the remaining affected areas within 10 years.  However, the installed point-of-use treatment
systems would effectively reduce concentrations of site-related contaminants as long as they are needed
and are properly maintained.

10.7   Five-Year Review

       A five-year review is reguired at sites where contamination remains above health-based criteria.
The review will be conducted in accordance with Section 121(c) of CERCLA, 42 U.S.C.  °9621(c),  as
amended, and applicable guidance and in a manner to assure the continued protection of the public health
and environment.

       The five-year review of the remedial action will be conducted to ensure that the remedy
implemented is effective and accomplishes the goals of the remedial action.  The review will include
monitoring of the point-of-use treatment units, and installation of new water mains to which the
households with treatment units could be hooked up.  The review will also examine the success of the
institutional controls at the Site area, i.e. the enforcement of the controls on new well construction.
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                                                               Table 3
                                                  Cost Estimate for Alternative  6A

       Item Description                                    Unit Cost         Quantity         Total Cost

Capital Costs
CERCLA Related PWSD #3 Capital Costs                                                               857,250
1 " PVC Main                                                 7 / ft.           17,400              121,800
8" Cast Iron Main                                           20 / ft.           52,300            1,046,000
House connection & tapping fee                               750 ea.              145              108,750
Water Softener/Installation                                1,325 ea.                5                6,625
Institutional controls                                        50,000                1               50,000
Subtotal Direct Capital Costs                                                                    2,190,425

Indirect Costs
Construction Management - 5% of Direct Construction Costs                                          109,521
Engineering Design - 5% of Direct Construction Costs                                               109,521
Contingency - 5% (c)                                                                               109,521
Subtotal Indirect Costs                                                                            328,564
Total Estimated Capital Costs                                                                    2,518,988

Operation & Maintenance Estimate
Bottled Water and Dispenser Rental  (years 1 and 2)        375 ea./yr.      123 x 2 yrs.              46,125
Sodium Chloride for Water Softeners  (for 10 years)        126 ea./yr.            5 yrs.               6,300
Water Softener Service Contract (for 10 years)             50 ea./yr.            5 yrs.               2,500
Biannual Monitoring (at years 1, 2, 5, and 10)            17,309 /yr.            4 yrs.              69,237
Administration of institutional controls                   6,250 /yr            10 yrs.              62,500
Subtotal O&M Costs                                                                                 186,662
Contingency - 15% (c)                                                                                27,999
Total Estimated O&M Costs                                                                          214,661
Present Worth of O&M Costs (d)                                                                     175,137

Total Present Worth for Alternative 6A (d)                                                        2,694,125

a.  The number of-households in the 0/D,  Neck/Alba,  and IGE DAS receiving Bottled water as of September 1997 is 80.
b.  When a public water supply becomes readily available, households are removed from the bottled water program and a bottle
    deposit return is  shown.
c.  Households identified as affected in the remedial design phase sampling program would be added to the remedial
    alternative.   Costs would be covered by the contingencies.
d.  All net present worth costs in 1997 dollars at 5% discount rate.
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11.0   Statutory Determinations

       Under its legal authority,  EPA's primary responsibility at Superfund sites is to undertake
remedial actions that achieve adequate protection of human health and the environment.   In addition,
Section 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 standards established under federal and state environmental laws,  unless a
statutory waiver is justified.  The selected remedy also must be cost effective and utilize permanent
solutions and alternative treatment technoloqies or resource recovery technoloqies 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.

11.1   Protection of Human Health and the Environment

       The selected remedy will protect human health and the environment by achieving the controls.
Existing human health risks due to consumption of metals contaminated shallow ground water will  be
eliminated by supplying affected household with public water or point-of-use treatment units.  Future
risks to human health will be reduced by implementation of institutional controls that will ensure proper
construction of private water wells.

       There are no short-term threats associated with implementation of the remedy that cannot  be
readily controlled.  In addition,  no adverse cross-media impacts are expected from the remedy.

11.2   Attainment ARARs

       The selected remedy will comply with all action- and location-specific ARARs, discussed below.
However, the selected remedy will not comply with the chemical-specific ARARs. Compliance with ARARs  is
required of the selected remedy unless a waiver of an ARAR is justified.  EPA has determined that meeting
the chemical-specific ARARs are technically impracticable and is issuing a waiver for this Site.  See
Attachment 1 for a detailed discussion on the technical impracticability of remediating the ground water.

       ARARs for the selected remedy are identified and categorized as either "Applicable" or "Relevant
and Appropriate" in Table 4 through 6.  These tables also describe the requirements for each ARAR.

11.2.1  Chemical-Specific ARARs

       None of the alternatives under consideration provide for cleanup of the shallow aquifer ground
water to drinking water standards because aquifer restoration is considered technically impracticable.
Thus, none of the alternatives can comply with the chemical-specific ARARs.  A technical impracticability
waiver of chemical-specific ARARs is necessary for the selected remedy for ground water at this  site.
Attachment 1 provide a detailed discussion of the technical impracticability of remediating the  shallow
ground water aquifer.  Although the availability of alternate water supplies by a public system or by
individual home water treatment systems will provide adequate drinking water to the affected residents at
this Site, the availability of such alternate water supplies does not obviate the need for a waiver of
chemical-specific ARARs.  The chemical-specific ARARs are listed in Table 4.

11.2.2  Location-Specific ARARs

       Compliance with location- and action-specific ARARs will be addressed during remedial design of
selected remedy which require construction of public water systems.  However, no remedial design problems
resulting in noncompliance are anticipated.

       The location-specific ARARs that will be attained by this remedial action are based on the
location of the Site and the effect of the hazardous substances on the environment.  The response actions
undertaken by the selected remedy will attain the location-specific ARARs for historic preservation,
archeological areas, and endangered species.  These location specific ARARs are identified in Table 5.

11.2.3  Action-Specific ARARs

       The action-specific ARARs are based on activities and technologies to be implemented at the site.
The water distribution system construction activities undertaken by the selected remedy will attain the
action-specific ARARs identified in Table 6.
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11.3   Cost-Effectiveness

       The selected remedy is cost-effective because it will provide overall effectiveness proportional
to its costs.  The selected remedy will achieve the remedial action objective,  and thus effectively
reduce unacceptable risks to human health,  at an estimated cost of $2.7 million.   The selected remedy is
the most expensive remedy that is protective of human health, and is selected because it is the most
protective, reliable,  and permanent of the alternatives considered, and is the alternative preferred by
the public.

11.4   Utilization of  Permanent Solutions and Alternative Treatment Technology to the Maximum Extent
       Practicable

         The selected remedy represents the maximum extent to which permanent solutions and treatment
technologies can be utilized in a cost-effective manner for this remedial action.  The hookup of
households with contaminated private water wells above health-based levels to public water supplies will
permanently eliminate  human health risks for these residents.  The community expressed to EPA during the
public comment period its concern that point-of-use treatment units were not as permanent and not as
reliable as public water, and that they preferred public water over the treatment units.  EPA
incorporated hookups to existing public water supplies to the greatest extent to reduce the reliance on
treatment units, resulting in a more permanent and reliable solution.  The other actions which are part
of the selected remedy, institutional controls and monitoring, are not as permanent as the engineering
actions, but will still provide a high degree of long-term effectiveness.

       The selected remedy provides the best balance among the alternatives evaluated with respect to the
evaluation criteria.  EPA relied strongly on the issue of permanence and reliability, as well as
community acceptance,  in selection of the remedy.  The selected remedy best meets the statutory
reguirement to utilize permanent solutions to the maximum extent practicable.

11.5   Preference for  Treatment as a Principal Element

       The selected remedy effectively reduces risks through a combination of engineering and
institutional controls, and includes treatment technology to the maximum extent possible.  Point-of-use
treatment units will be installed where affected households cannot be cost effectively connected to
public water supplies.

       EPA assessed treatment of the ground water aguifer to remove metals contamination from the aguifer
itself and determined that treatment is technically impracticable.  See Attachment 1 for more
information.
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Standard, Requirement, Criteria, or
Limitation

FEDERAL
National Primary Drinking
Water Regulations
National Primary Drinking
Water Regulations

National Secondary Drinking
Water Regulations
Final Guidance on Numeric
Removal Action Levels for
Contaminated Drinking Water
Sites
STATE
Missouri Safe Drinking Water Act
Missouri Safe Drinking Water
Regulation
Lead General Requirements
 Citation
40 CFR Part 141
                                                                                        Table  4
                                                                Chemical-Specific ARARs and Guidance  to Be Considered
             Description
40 CFR Part 141
40 CFR Part 143
OSWER Directive 9360.1-
02
Missouri Revised Statutes
(RSMo)640.100-140

10 Code of State
Regulation (CSR) 60
10 CSR 60-15.010
  ARAR
or TBC
 Establishes  health-based primary drinking water standards,
 MCLs  and MCL Goals,  for public drinking water systems             ARAR

Cadmium MCL - 0.005 mg/1

Lead Action Level - 0.015 mg/1                                    TBC
Secondary drinking water standards, SMCLs, to control
contaminants in drinking water that affect the aesthetic
qualities relating to the public acceptance of drinking water.    TBC

Manganese MCL - 0.05 mg/1
Zinc MCL - 5.0 mg/1

Transmits final methodology and guidance on calculating
numeric RALs at Superfund sites in deciding whether to
provide alternate sources of drinking water.                       TBC

Manganese RAL - 0.20 mg/L
Zinc RAL - 3.0 mg/L
                                                                   TBC

Contains MCLs and monitoring requirements for drinking
water supplies.

Cadmium - 0.005 mg/1                                              ARAF
Zinc -5.0 mg/1
Manganese - 0.05 mg/1

Establishes treatment requirements for corrosion control,
source water treatment, and lead service line replacement.
Defines lead action levels.                                        TBC
Lead Action Level - 0.015 mg/1
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Standard,  Requirement,  Criteria,  or
Limitation

FEDERAL
                                            Citation
                                                                                        Table  5
                                                                Location -Specific ARARs and Guidance to Be Considered
                                    Description
                                                            ARAR or
                                                                TBC
Archaeological and Historic
Preservation Act
Archaeological Resources Protection
Act
16 USC Sees.  469-469c-
1
40 CFR Sec.  6.301 (c)
16 USC Sees.  470aa-mm
Establishes procedures to provide for preservation of
historical and archaeological data which might be destroyed     ARAR
through alteration of terrain as a result of a Federally
licensed activity or a program.

Requires permit for any excavation or removal of
archaeological resources from public or Indian lands.
Provides guidance for federal land managers to protect such     ARAR
resources.
National Historic Preservation Act
Executive Order 11593
Historic Sites, Buildings, and
Antiquities Act
Fish and Wildlife Coordination Act
Fish and Wildlife Conservation Act
Endangered Species Act
16 USC Sec.  470
40 CFR Sec.  6.301 (b)
36 CFR Part  800
36 FR 8921,  5/3/71

16 USC Sees.  461-470
40 CFR Sec 6.301(a)
                                            16 USC Sees. 661-666b
                                            40 CFR Sec. 6.302(g)
                                            16 USC Sees. 2901-2912
16 USC Sees.  1531-1544
50 CFR Parts  17,  402
40 CFR Sec.  6.302(h)
Requires Federal agencies to assess the effect of any
Federally assisted undertaking or licensing on any district,
site, building, structure, or object that is included in or     ARAR
eligible for the National Register of Historic Places.

Requires Federal agencies to consider the existence and
location of landmarks on the National Registry of Natural       ARAR
Landmarks to avoid undesirable impacts on such landmarks.

Requires any Federal agency or Federally permitted entity to
consult with the U.S. Fish and Wildlife Service and
appropriate state agency prior to modification to any stream    ARAR
or body of water.  The intent is to conserve,  improve, or
prevent loss of wildlife resources.

Requires Federal agencies to utilize their statutory and
administrative authority to conserve and promote                 TBC
conservation of non-game fish and wildlife species.

Requires that Federal agencies insure that any action
authorized, funded,  or carried by the agency is not likely to
jeopardize the continued existence of any threatened or         ARAR
endangered species or destroy or adversely modify critical
habitat.
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Executive Order on Floodplain
Management
Executive Order on Protection of
Wetlands
Farmland Protection Policy Act
EPA Policy to protect environmentally
significant agricultural lands

RCRA
Executive Order No.
11988
40 CFR Sec. 6.302(b) and
Appendix A

Executive Order No.
11990
40 CFR Sec. 6.302(a) and
Appendix A

7 USC 4201 et. seg.
40 CFR Sec. 6.302(c)
                                            42 USC Sec. 6901
                                            40 CFR 264,18(b)
Reguires Federal agencies to evaluate the potential effects of
actions they may take in a floodplain to avoid, to the           TBC
maximum extent possible, the adverse impacts associated
with direct and indirect development of a floodplain.

Reguires Federal agencies to avoid, to the maximum extent
possible, the adverse impacts associated with the destruction    TBC
or loss of wetlands and to avoid new construction in
wetlands if a practicable alternative exists.

Protects significant or important agricultural lands from
irreversible conversion to uses which result in its loss as an   TBC
environmental or essential food production resource.

Reguires that any hazardous waste facility located within
the 100-year floodplain be designed, constructed, operated,     ARAR
and maintained to avoid washout.
STATE

Missouri Safe Drinking Water Act

Missouri Safe Drinking Water Act
Regulations

    *     Siting Reguirements,
          Recreational Use of
          Impoundments
RSMo 640.100-140

10 CSR 60


10 CSR 60-10
Contains MCLs and monitoring reguirements for drinking          ARAR
water supplies.

Prohibits siting new or expanded water supply systems in
areas subject to significant risk from earthguakes, flood,
fires, or pollution.  Contains provisions for the use of public  ARAR
 water supply impoundments for recreation.
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                                                                                       Table  6
                                                                 Action-Specific ARARs and Guidance to Be Considered
Standard, Requirement, Criteria,
or Limitation
    Citation
                        Description
                                                                                          ARAR or
                                                                                              TBC
FEDERAL

Safe Drinking Water Act

    *    Hazardous Waste Injection
         Restrictions

STATE

Missouri Water Resource Law
42 USC Sees.  300f-300j

40 CFR Part 148
                                          RSMo 640.400-435
Identifies hazardous wastes that are restricted from disposal
into Class 1 hazardous waste injection wells.                    ARAR
                            Establishes state surface and ground water monitoring and
                            inventory program,  which is to include determination of
                            ambient surface and ground water quality,  detection of           ARAR
                            trends in character and concentration of contaminants and
                            pollutants, and identification of areas highly vulnerable to
                            contamination.
Major Water User Registration
Missouri Water Well Driller's Law
Missouri Public Drinking Water
Program Guidelines
RSMo 256.410
10 CSR 23
                                          RSMo 256.600-640
                                          10 CSR 23
Requires major water users (>100,000 g.p.d.)  to file a
registration document with the Division of Geology and
Land Survey, Department of Natural Resources

Sets fees and standards to be followed in installing,
maintaining, and abandoning water wells and monitoring
wells.  Also covers well plugging and proper isolation of
possible sources of contamination from existing wells to
protect the quality of ground water aquifers that provide
safe drinking water.
 Missouri Dept.  of Natural  Public Drinking Water Program guidelines for public water
 Resources Design Guide     system design including recommendations for both water
 for Community Public       quality and quantity.
 Water Supplies,  January
 1988
                                                                                                                                       ARAR
                                                                                                                                       ARAR
                                                                                                                                       ARAR
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Missouri Safe Drinking Water Act
    *    Source Water Treatment
         Requirements for Lead and
         Copper

    *    Public Education and
         Supplemental Monitoring
         Requirements
RSMo 640.100-140
10 CSR 60

10 CSR 60-15.040
10 CSR 60-15.060
    *    Monitoring Requirements for       10 CSR 60-15.090
         Lead and Copper in Source Water
Contains MCLs and monitoring requirements for drinking           ARAR
water supplies.

Provides source water treatment options for systems that
exceed lead and copper action levels                              TBC
Provides format for informing the public about the health
effects of lead and copper in drinking water.                     TBC
                           Contains collection methods and sample location and size
                           requirements for systems that exceed lead or copper action        TBC
                           levels and systems where source treatment has begun.
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12.0   Documentation of Significant Changes

       EPA has modified the selected remedy from the Proposed Plan by reducing the number of point-of-use
treatment units, hooking up threatened residences to public water supply lines, and including the cost of
hook ups as part of the capital costs.  This results in a significant cost increase in the selected
remedy from the Proposed Plan.  The overall remedial approach represented by the selected remedy remains
the same as the Proposed Plan, which is to provide alternate water supplies to residents using the
contaminated shallow aguifer for drinking water supplies.  Thus, the changes do not fundamentally alter
the remedy.

       The changes are based on significant comments received from the affected community.  During the
public comment period, EPA received new information that several water mains are already in place and can
be readily used to provide public water in certain areas.  Thus, Alternative 7 is no longer a preferred
afternative as stated in the Proposed Plan because it no longer provides the most appropriate balance of
tradeoffs among the alternatives with respect to the nine evaluation criteria.  EPA has determined that
Alternative 6A  (a modification of Alternative 6 in the Feasibility Study)  is the best balance of
tradeoffs.

       Alternative 6A is the best way to provide alternative water supplies and utilize the existing
public water infrastructure.  The main difference between Alternative 6 (as described in the Proposed
Plan)  and Selected Remedy is the provision of public water supplies not only to the affected private
water well users  (wells with exceedances of SDWA standards), but also to the threatened private water
well users.  Alternative 6 provided public supplies to only 51 residences and monitored the threatened
residences.  The Selected Remedy provides public supplies to 340 residences.  However, five homes that
are too remote from water mains will be provided treatment units and monitored.  In addition, Alternative
6A includes the hook up fees for the residents and Alternative 6 did not.   The additional costs in the
Selected Remedy from the increase in the number of hook ups and the inclusion of hook up fees is
estimated to be approximately $774,448.  Another reason the cost estimate increased in the Selected
Remedy compared to Alternative 6 is because of an need for an estimated 52,300 linear feet of eight inch
cast iron main pipeline necessary for service connections to the Missouri American Water Company
supplies.  The cost for this type of water main is estimated at $1,046,000, which is an increase of
$483,274 over the estimate for the smaller PVC mains proposed in Alternative 6.  See Table D-3 in the
Feasibility Study.

       EPA estimates the cost of providing public water to each of the 340 residences in the area is
about $7,923 per residence.  Thus, Alternative 6A is a cost-effective way to provide 340 families with
safe,  permanent and reliable drinking water.  For comparison Alternative 6 proposed hookup of 61
household to public water at a cost of $1,436,403, or $23,547 per home. Alternative 7 proposed suppling
alternate water supplies through PWSD #3 and treatment units to 223 homes at a cost of $1,236,857, or
$5,546 per home.

       The majority of the cost increase between Alternative 6 (which was  subject to notice and comment)
and Alternative 6A, is the increase associated with the provision of public supplies to threatened homes.
The public had an opportunity to comment on the need for the remedy to address threatened residences as
opposed to only those residences with actual exceedances, e.g., see the comment ftom ASARCO, page 2 of
the Responsiveness Summary.  Thus, the changes in Alternative 6A, while significant in terms of cost
estimate, were reasonably anticipated based on information available to the public in the Proposed Plan
and the Feasibility Study.  The changes are more fully described in Section 10 of this ROD.  Further
public comment is not warranted given the strong public support for public water supplies during the
comment period and that the changes could have been reasonably anticipated.
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                                              Attachment # 1
                                  Technical Impracticability Information
Purpose
       This attachment to the Record of Decision (ROD)  for the Ground Water Operable Unit of the
Oronogo/Duenweg Mining Belt Superfund Site, Jasper County, Missouri, provides justification for the U.S.
Environmental Protection Agency  (EPA) determination that attainment of federal and state drinking water
standards in the shallow aguifer is technically impracticable  (TI) from an engineering perspective.  This
information compliments Sections 10 and 11 of the ROD.   The reader should refer back to these ROD
sections for additional detail, as this attachment is intended as a supplement to the existing provided
information.

       This TI information is intended to provide rational for not achieving the chemical-specific
applicable or relevant and appropriate reguirements (ARARs).   Ground water in this shallow aguifer
typically exceeds risk-based federal primary maximum contaminant level (MCL) safe drinking water
standards for cadmium, and nickel; secondary drinking water standards for manganese; and lead action
levels under the Safe Drinking Water Act  (SDWA)   (not an MCL).  In particular, the risk-based standards
under the SDWA for cadmium, lead, manganese, nickel, and zinc have been exceeded in the shallow aguifer.
This waiver is expected to cover the entire watershed within Jasper County.

       The justification for this determination of TI  is based on the fact that compliance with legally
ARARs would be inordinately costly from an engineering perspective.

Background

       The Ground Water Operable Unit of the Oronogo/Duenweg Mining Belt Site is located throughout
Jasper County.  The Site encompasses approximately 270 sguare miles or nearly 40,000 acres and contains
an estimated nine million cubic yards of mining wastes.  The Site is a component of the much larger
Tri-State Mining District which is estimated at approximately 500 sguare miles and covers portions of
southeast Kansas, southwest Missouri, and northeast Oklahoma.   The Tri-State District was mined for
approximately 100 years from the mid to late 1800s to the mid 1970s.  Figure 1 illustrates the location
of the Oronogo/Duenweg Mining Belt Site.

       Three EPA National Priority List (NPL)  Superfund sites  are contained within the Tri-State Mining
District and consist of the following:  Cherokee County, Kansas; Tar Creek, Oklahoma; and Jasper County,
Missouri.  A fourth Missouri site is currently in the early stage of an EPA removal program assessment
(Newton County, Missouri).  EPA Regions VI  (Tar Creek,  Oklahoma site) and VII  (Kansas and Missouri sites)
have coordinated on the cleanup actions completed to date.  The three NPL sites are complex large area
lead sites that have been subdivided into several subsites and/or operable units.  Figure 1 in the ROD
depicts the locations and descriptions of the Oronogo/Duenweg site and the engineering components of the
selected remedy.  Additionally, Tables 2 and 3 in the ROD include descriptions and comparisons of the
selected remedy, including costs, and other evaluated alternatives.

Conceptual Hydrogeologic Model

         The Oronogo/Duenweg site is underlain by two distinct hydrogeologic units that are generally not
in hydraulic communication.  The upper hydrogeologic unit is comprised of Mississippian age formations
which host the ore bearing mineral deposits that were actively mined.  The lower hydrogeologic unit
consists of Roubidoux, Eminence, Potosi, and Lamotte formations consisting of sandy dolomites and
lenticular sandstones which are hydraulically separated from the uppermost unit by lower Mississippian
age shales and argillaceous limestones.  The conceptual hydrogeologic model is depicted by Figure 1 of
this Attachment. The uppermost aguifer is in communication with the following features:  ore deposits;
milling and mining wastes that have been placed in abandoned mine workings; exploration shafts, tunnels,
and mine ventilation holes; and mined drift areas.  The uppermost hydrogeologic unit is unconfined and is
characterized by poor water guality due to high levels of calcium sulfate.  Well yields in the shallow
aguifer are highly variable and, on a site-wide basis,  are predominantly dependent on secondary
permeability features within the Mississippian formation.  Secondary permeability results from solution
enlargement along bedding planes, fractures, or solution channels, or dissolution and collapse of
limestone.  Limestone collapse has created brecciated areas which were later focal points of
mineralization.  Highly permeable breccia areas may yield up to several hundred gallons per minute (gpm)
of water, whereas areas of non-brecciated, unaltered limestone generally have low yields.  Secondary
permeability has also been created in areas of extensive interconnected mine workings.  Recharge of the
shallow aguifer occurs through infiltration of precipitation on the permeable Mississippian limestones
which comprise the majority of surface outcrops, particularly south and east of the Spring River.
Recharge is  Recharge is fairly rapid as precipitation infiltrates guickly and is transmitted along
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solution enlarged openings.  Topographic highs constitute recharge areas at the site; specifically the
southern end of the Oronogo/Duenweg Designated Area, and to a lesser extent in the area between Center
Creek and Spring River.  Ground water flow in the shallow aguifer generally follows surface topography.
In general, shallow aguifer ground water is not transmitted across major streams including Turkey and
Center Creeks, North Fork of the Spring River, and the Spring River.  Zones through which no ground water
flows occurs are called hydrologic boundaries.  Therefore, major streams are considered hydrologic
boundaries in the shallow aguifer.  However, upper Turkey Creek and Grove Creek do not act as hydrologic
divides.  Due to the generally large relief in the area, it should be expected that only shallow flow
systems should occur; that is, that shallow aguifer ground water will flow only to the next topographic
low and discharge there.  With few exceptions, discharge areas occur along all major streams at the site.
Additionally, discharge occurs through seeps, springs, shallow aguifer wells, flowing mine openings, and
collapsed features.

       The lower hydrogeologic unit consists primarily of the Cambrian/Ordovician Age Roubidoux,
Eminence, Potosi, and Lamotte dolomites and sandstone formations.  The lower aguifer is recharged by
precipitation to the formations where they outcrop in the Ozark region,  well to the southeast of Jasper
County.  No effects of local precipitation on ground water levels in the deep aguifer have been observed.
Abandoned or deteriorating wells, exploratory drill holes and shafts may also allow some leakage to the
deep aguifer, although such conditions have not been confirmed in Jasper County.  The U.S. Geological
Survey study of the deep aguifer in northeastern Oklahoma determined that,  in all instances,
contamination of the deep aguifer can be explained by faulty well seals or leaky well casings that allow
shallow aguifer water to enter the well bore.  Flow in the deep aguifer occurs under a generally
east-to-west trending regional gradient with the driving force coming from recharge via precipitation on
the western flank of the Ozark Mountains.  This regional flow is impacted by withdrawal of ground water
by local rural water districts (RW/Ds) or other private or commercial wells resulting in local cones of
depression.  Other than pumped wells, the deep aguifer has no apparent discharge to the surface at the
site.  Deep aguifer water is of a calcium-bicarbonate type with secondary magnesium, as is typical of a
dolomite aguifer.  Metal levels in the deep aguifer are typically low with maximum constituent
concentrations below MCLs for arsenic, cadmium, lead, manganese, nickel, and zinc. Cities or communities
that derive their water supply from deep aguifer wells are:  Alba, Neck City, Carl Junction, Carterville,
Duenweg, Oronogo, Purcell, and Webb City.  The lower aguifer also provides water for agricultural and
industrial use.

Contaminant Sources

       The major contaminant sources for the shallow ground water are the result of the previous mining
operations that have occurred over the approximately 100 years of mining operations. The rock in Jasper
County was mined from the mid to late 1800s to the mid 1970s and in the process produced mine waste
piles, pits, and lagoons.  The pits and lagoons which contained surface water became contaminated with
high levels of metals.  Further interaction of this highly oxygenated surface water with the shallow
aguifer system caused high levels of metals contamination within the shallow aguifer through dissolution
of metals from mineral surfaces left in the mine voids.  Additionally, residual mineral deposits left in
the mine openings are now in contact with oxygenated ground water which contributes to metals leaching
and further contamination of the ground water.

Ground Water Use

       Ground water in Jasper County occurs in two aguifers,  the shallow and the deep aguifer,  which are
separated throughout the region by a confining unit as shown conceptually on Figure 1.  Aguifers are
geologic formations that can transmit usable guantities of water, while confining units yield little or
no water and tend to impede transmission of water between geologic formations.  The shallow aguifer can
occur in any of the Mississippian formations although little water is provided by the Fern Glen
Formation.  The shallow aguifer averages approximately 300 feet in thickness, ranging to a maximum
thickness of approximately 400 feet.  The shallow aguifer is used as a source of drinking water in
portions of the site not served by municipal or rural water districts.  The shallow drinking water is
used as a drinking water supply in Neck/Alba, Oronogo-Duneweg, and Iron Gates Extension designated areas
of the Site.  There are approximately 600 residential homes served with ground water from the shallow
aguifer.

       The deep aguifer ranges up to 850 feet.  The majority of water is supplied by tile Roubidoux
Formation and the Eminence and Potosi Dolomites.  The deep aguifer is a confined aguifer overlain and
underlain by relatively impermeable materials.  The deep aguifer is a major source of drinking water for
Alba, Neck City, Carl Junction, Carterville, Duenweg, Oronogo, Purcell,  and Webb City.  There are
approximately 10,000 residential homes served with ground water from the deep aguifer.  The deep aguifer
is also used for agricultural and industrial use.
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Restoration Potential

       As discussed above,  the Site encompasses approximately 270 square miles.   Ground water flow in the
shallow aquifer occurs primarily in the fractured breccia zones and secondary openinqs created by both
the dissolutioninq of the bedrock formations and underqround mininq. Water well samplinq conducted durinq
Site investiqations has shown that distribution of metals contaminated in the shallow qround water is
extremely sporadic.  Action level exceedance of metals in individual wells is dependant on interception
of fracture zones connected to contaminant sources.  This condition prohibits affective cleanup by
conventional qround water pump and treat systems to restore the aquifer for safe drinkinq water use.   EPA
has determined that desiqn of a qround water recovery system and placement of pumpinq well to intercepted
all fractures and openinqs conductinq contaminated would be nearly impossible.  The TI determination is
based on the technical difficulty, as well as,  the inordinate cost to attain the ARARs for the protection
of human health.  However,  limited qround water remediation may be conducted as part of a subsequent ROD
to address ecoloqical risks created by qround water contributions to surface water.

Inordinate Cost Determination

       To meet the chemical-specific ARARs for the shallow qround water,  an extensive pump and treat
system would be needed at numerous locations within Jasper County to treat tile contaminated shallow
qround water.  The sheer size of Jasper County makes the cost prohibitively hiqh.  The cost to treat the
metals-contaminated qround water is estimated to be $2.5 per 1,000 qallons of qround water and the total
cost would ranqe from $60 - 90 million.  In addition,  it is difficult to predict if the MCLs would be met
with a pump and treat type of alternative because the mine wastes in Jasper County are expected to
continue leachinq into the shallow qround water system and deem cleanup virtually impossible.

       Treatinq the shallow qround water would include pumpinq the water into larqe above qround storaqe
tanks, chemical precipitation of the metals from the qround water, repumpinq the "cleaned water" back to
the shallow aquifer, and disposal of hazardous waste sludqe.  This cost estimate assumes that the system
would operate for 30 years and require monitorinq for an additional 10 years.  The major cost items would
be the pipinq and pumps (as well as the enerqy requirements), chemical precipitation chemicals, hazardous
waste disposal costs, and the labor associated with implementinq this process.

    Maior Cost Component         Cost Ranqe ($ million)

                                        4

    Pipinq and Pumps                   10-20
    Enerqy Requirements                5-10
    Chemical Precipitation Chemicals   5-10
    Hazardous Waste Disposal           20-30
    Labor Requirements                 10-20

       EPA considers the increased cost of enqineerinq actions at the Oronoqo/Duenweq Site to be
inordinately costly when considerinq the fact that Alternative 6A, the Selected Remedy, will protect
human health for all residents at the Site.  Any qain would be very limited since Alternative 6A would
protect the health of all residents.

       The positive environmental impacts include beinq able to use the shallow qround water system as a
drinkinq water source in the future and improvinq the water quality of receivinq stream.  The neqative
environmental impacts resultinq from this pump and treat alternative include possibly lowerinq water
levels at local streams, disruptinq the ecoloqical system, and chanqinq naturally occurrinq wetlands.  An
additional neqative impact would be the possibility of drawinq down the shallow aquifer past where it
could no lonq be used for aqricultural and industrial purposes.

       After consideration of all facts,  in combination with the size and volume (nine million cubic
yards) of mininq wastes at the site, EPA considers remediation of Oronoqo/Duenweq Superfund site to be
technically impracticable based on inordinate costs from an enqineerinq perspective.
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Selected Remedy

       The selected remedy,  Alternative 6A,  provides for a high degree of protection for residential
homes and human health; however, none of the Feasibility Study report alternatives were deemed capable of
meeting chemical-specific ARARs established by the SDWA.  Chemical-specific ARARs would not be met in the
shallow aguifer in all areas of the site because treatment of the shallow aguifer to improve water
guality is technically impracticable from an engineering perspective as discussed above.  However,
Alternative 6A will provide a public water supply that meets federal and state drinking water standards
(chemical-specific ARARs) at the point-of-use for those households that choose to use and pay for public
water.  Those households that do not choose to connect to the public water system would potentially be
using ground water that does not meet these standards.

       Alternative 6A is also expected to comply with all potential location-specific ARARs listed in the
ROD.  Construction of water distribution lines is expected to occur in existing county right-of-way or
easements where roads or the utilities are already located.  Therefore, construction activities are not
expected to impact sensitive ecological areas such as wetlands, endangered species habitat, flood plains,
or wild and scenic rivers.  Also, protection of known historical or archaeological sites will be ensured
by designing around any identified sites.

       The new water distribution systems to be installed as part of this remedy will be designed to
readily comply with the ARARs identified for this alternative.  Action-specific ARARs identified for
Alternative 6A include the Missouri Public Drinking Water Program Guidelines and the federal and Missouri
Safe Drinking Water Acts.  Other potential action-specific ARARs identified in the ROD are not expected
to apply to this remedy because developing new water resources or drilling new deep wells is not
reguired.  Only the construction and O&M of distribution systems is proposed.


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                                               Attachment #2
                                          Responsiveness Summary
                                      Ground Water, Operable Unit 04
                                     Oronogo/Duenweg Mining Belt Site
                                          Jasper County,  Missouri
Introduction
This Responsiveness summary has been prepared in accordance with the Comprehensive Environmental
Response, Compensation and Liability Act (CERCLA),  as amended by the Superfund Amendments and
Reauthorization Act (SARA), and the National Contingency Plan (NCP)  40 CFR ° 300.430 (f).   This document
provides the United States Environmental Protection Agency's (EPA)  response to all significant comments
received on the Proposed Plan from the public during the 30-day comment period.

       On March 16, 1998,  the EPA released the Proposed Plan and Administrative Record File containing
the Remedial Investigation, Human Health Risk assessment,  Feasibility Study, and other pertinent
documents for public review and comment.  The Proposed Plan discussed the EPA's proposed action to
address ground water contaminated with lead and cadmium.  The public comment period was open from March
16 to April 17, 1998.   The EPA held a public meeting on March 24 at Missouri Southern State College in
Joplin, Missouri,  to present the Proposed Plan and discuss results of investigations and the Feasibility
Study.  A copy of the transcript from the public meeting is included in the Administrative Record File.

Comments Received from the Public and Responses

       The following significant comments were received in writing during the comment  period or verbally
during the public meeting.

       Two citizens in the Iron Gates Extension Designated Area (IGE DA)commented  that several of the
households in that area proposed for point-of-use treatment units were within ^> mile of public water
supply lines and should hooked up to these main in lieu of treatment units.

       EPA considered this comment and modified the selected alternative to include hookups to public
water in the IGE DA.

The City of Joplin commented that they are pursuing annexation in a portion of the Oronogo/Duenweg
Designated Area (0/D DA)  and would be reguired to extend public water supply mains into the area, but
only to within 600 feet of residences for fire protection.  The City reguested that EPA consider bearing
the expense for hooking up the households in the area since many homeowners many not be able to afford to
extend service the extra 600 feet to their home.

       EPA considered this comment and modified the selected alternative to include hookups to public
water in the 0/D DA during the remedial action.

       The Jasper County Health Department and the  Jasper  County Superfund Site Coalition (JCSSC)
commented that several households are located within Public Water Supply Districts (PWSDs) No. 1 and No.
2 that not hooked up to those systems and are using private shallow water wells.  They stated that these
households should be sampled and monitored.

       EPA has incorporated monitoring of households in these areas  into the selected  remedy.   If
households are found with wells exceeding action levels in the existing PWSDs they will be hooked up to
the public system.

       PWSD No. 3 and the JCSSC both commented that they support EPA's decision to include their district
into the selected alternative.

       EPA's selected remedy includes PWSD #3.

       ASARCO Incorporated, one of the potentially  responsible parties for the contamination at the site,
made several comments that the EPA should select Alternative 4 from the Feasibility Study, which consists
of point-of-use treatment units only.

       ASARCO comments that private shallow aguifer water  wells not  currently exceeding the established
water guality standards under the Safe Drinking Water Act   (SDWA) are not threatened because there is no
indication that such wells are getting progressively worse. ASARCO comments that any wells not now
affected by heavy metal contamination are unlikely to become affected in the future.   ASARCO commented
that contamination from past mining disturbance would likely be diminishing through time.  EPA strongly
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disagrees.  The selected remedy provides alternative water supplies to threatened residences in the
affected areas that use the shallow aquifer because the Remedial Investigation and Feasibility Study for
this Operable Unit clearly demonstrate that the shallow aguifer is affected by inactive mining and
mineralization.  The characterization of the nature and extent of groundwater contamination at the site
clearly defines areas that are threatened with contamination are within ^> to 1/4 mile of mining and
mineralization.  In general, the residences that receive alternate water supplies under the selected
remedy are located in such areas.  In addition, even the average levels of contaminants of concern in the
shallow ground water exceed the established criteria for safe drinking water under the Safe Drinking
Water Act  (SDWA).   Moreover, Attachment #1 to this ROD, Technical Impracticability Information, strongly
supports the need to protect the threatened private water well users.  Attachment #1 summarizes evidence
in the record that (1)  the shallow ground water is contaminated with high levels of metals and (2) the
shallow aguifer contamination is extremely wide spread with ground water flowing such that the
distribution of heavy metal contaminants in the shallow aguifer is extremely sporadic.  "Action level
exceedance of metals in individual well is dependant on interception of fracture zones connected to
contaminant sources," Attachment #1, page 2.  In this ground water, the fracture zones (which can occur
at any time due to solution of the limestone)  as well as the extensive interconnected mine workings
(which are constantly subject to subsidence and solution enlargement) provide the secondary permeability
that result in highly variable well yields and thus, highly variable levels of contamination within the
aguifer.  Finally, EPA finds nothing in the records that supports any natural attenuation of the
contamination in this aguifer nor is there any evidence in the record that contamination left over from
mining activities will diminish over time.  In the administrative record, the evidence shows that under
the status guo, acid mine drainage continues and contamination spreads throughout the shallow aguifer.

       The evidence in the Administrative Record for this ROD supports the decision to provide alternate
water supplies to the threatened residences.  In addition, the statutory requirements of CERCLA authorize
EPA to provide for the remediation of the release or "substantial threat of such a release" of hazardous
substances that may present an imminent and substantial danger to public health or welfare.  Section
104(a) (1) of CERCLA,  42 U.S.C. ° 9601 (a) (1).   The evidence in the Administrative Record supports this
reasonable and rationale decision to protect the threatened residences at this site.

ASARCO also comments that long term monitoring of the residences with water softeners is unnecessary and
that long-term monitoring would be necessary for public water supplies.  EPA disagrees that monitoring is
unnecessary for the water softeners.  We agree that monitoring is required for the public supplies as
environmental laws require public suppliers to monitor source waters.  However, with the provision of
public supplies,  long-term monitoring of the effectiveness of water softeners as a method to treat the
contaminated shallow aquifer will no longer be required for those residences that hook up to the public
supplies.

       Thus,  the  selected remedy has reduced the proposed monitoring costs.   The selected remedy
continues to require monitoring of the five water softening units that will be provided because of the
uncertainties associated with the installation, operation and maintenance of these units.  Such
monitoring is not prescribed by environmental laws, but is required based on the human health risks at
this site from consuming the shallow aquifer water that is contaminated from actual or threatened
releases of hazardous substances.

       Several citizens questioned the institutional controls and the ability to install future shallow
water supply wells.

       EPA anticipates enforcement of the Missouri well drilling laws to control future well installation
at the Site.   However,  EPA is working closely with the local communities through the Environmental Task
Force of Jasper and Newton Counties to develop an environmental master plan for Jasper and Newton
Counties.  This plan will contain recommendations for institutional controls.  EPA will support the
communities in implementation of the controls.

       The JCSSC  made numerous comments concerning the effectiveness of the point-of-use treatment units
to reduce metals  concentrations in ground water supplied to households from private wells.  The JCSSC
made comments concerning the effectiveness of the monitoring and maintenance of the treatment units.

       EPA found  during the Remedial Investigation at the Site and through installation of treatment
units in homes in Galena, Kansas, as part of remedial action there, that treat units are very effective
at reducing metals concentrations below action levels without the problems mentioned by the JCSSC.
However, EPA has  selected a remedy that does not rely on treatment units except at five homes that cannot
cost effectively be connected to a public water supply.  The selected remedy eliminates the need for most
of the treatment  units and most of the monitoring of the treatment units and threatened well that JCSSC
commented on.
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       JCSSC commented that selection of Alternative 7 would create significant health and financial
inequities between those homes receiving point-of-use treatment units and those hooked up to public
water.

       EPA has addressed this issue by selecting Alternative 6A as the remedy for the Site.   Under the
selected remedy, all but five affected households will be connected to public water supplies.
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