Superfund Record of Decision Cherokee County Baxter Springs and Treece Subsites Operable Unit 3/4 Cherokee County KS


                                    EPA/ROD/R07-97/073
                                    1997
EPA Superfund
     Record of Decision:
     CHEROKEE COUNTY
     EPA ID: KSD980741862
     OU 03, 04
     CHEROKEE COUNTY, KS
     08/20/1997

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                                             RECORD OF DECISION





                                                   FOR THE





                                     BAXTER SPRINGS AND TREECE SUBSITES





                                           OPERABLE UNITS #03/#04





                                       CHEROKEE COUNTY SUPERFUND SITE





                                          CHEROKEE COUNTY, KANSAS
                                                Prepared by:





                                    U.S.  ENVIRONMENTAL PROTECTION AGENCY





                                                 REGION VII





                                            KANSAS CITY, KANSAS





                                                AUGUST  1997

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                                            RECORD OF DECISION

                                                DECLARATION

SITE NAME AND LOCATION

    Baxter Springs and Treece Subsites - Operable Units #03/#04
    Cherokee County Superfund Site
    Cherokee County, Kansas

STATEMENT OF BASIS AND PURPOSE

       This decision document presents the selected remedial action for the mining and milling wastes at
the Baxter Springs and Treece subsites, which are part of the Cherokee County Superfund site in Cherokee
County, Kansas.  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:

    Johnston Public Library      U.S. Environmental Protection Agency
    210 West 10th Street         Region VII Docket Room
    Baxter Springs, Kansas       726 Minnesota Avenue
                                 Kansas City, Kansas

       The state of Kansas concurs with the selected remedy.  The local community also concurs with this
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), present a current threat to
public health, welfare, or the environment.

DESCRIPTION OF THE SELECTED REMEDY

       The U.S. Environmental Protection Agency  (EPA)  believes the selected remedy appropriately
addresses the principal current and potential risks to human health and the environment.  The remedy
addresses human health risks at both subsites and ecological risks at the  Baxter Springs subsite.  The
selected remedy includes actions for the source materials  (mining/milling  wastes), groundwater, surface
water, and soils.  This single ROD addresses two discrete subsites of the  Cherokee County site.  The
major components of the selected remedy, which are specific to only the Baxter Springs subsite, include
the following:

             Excavation, relocation, regrading, capping, and revegetation  of mine/mill waste piles,
             tailings impoundments, and tailings outwash deposits,

             Stream re-channelization and construction of stream diversion/control structures; and

             Prevention of mine water discharges.

The major remedy components for both the Baxter Springs and Treece subsites include the following:

             Investigation and potential remediation of residential yards  impacted by mining/milling
             wastes;

             Closure/abandonment of poorly constructed existing deep water wells and borings to protect
             the deep aguifer;

             Institutional controls for future development; and

             Operation and maintenance of all remedy aspects which include, but are not limited to, the
             following:  capped areas; stream diversion/control structures; institutional controls; and
             long-term monitoring.

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STATUTORY DETERMINATIONS

       The selected remedy is protective of human health and the environment,  complies with federal and
state laws that are legally applicable or relevant and appropriate requirements (ARARs) for the remedial
action, and is cost effective.  However, chemical-specific ARARs under the Clean Water Act regulating
surface water quality and the Safe Drinking Water Act regulating groundwater drinking water will not be
met by the selected remedy.  EPA has determined that it is technically impractical to meet these
standards at both subsites.

       This remedy utilizes permanent solutions and alternative treatment technologies to the maximum
extent practicable. However, because treatment of the principal threats was not found to be practicable,
this remedy does not satisfy the statutory preference for treatment as a principal element.

       This remedy will result in hazardous substances remaining on the site above health based levels.
Therefore, a review will be conducted within five years after commencement of remedial action to ensure
that the remedy continues to provide adequate protection of human health and the environment.

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          RECORD OF DECISION





           DECISION SUMMARY





   BAXTER SPRINGS AND TREECE SUBSITES





        OPERABLE UNITS #03/#04





    CHEROKEE COUNTY SUPERFUND SITE





        CHEROKEE COUNTY, KANSAS
             Prepared by:





U.S. ENVIRONMENTAL PROTECTION AGENCY





              REGION VII





          KANSAS CITY, KANSAS





              AUGUST 1997

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                      TABIiE OF CONTENTS

SECTION                                                     PAGE

1.0  Site Description	     1

2.0  Site History   	     2

3.0  Highlights of Community Participation  	     3

4.0  Scope and Role of operable units	     4

5.0  Baxter Springs and Treece Subsite Characteristics  .  .     6

6.0  Summary of Site Risks	    10
      6.1  Human Health Risks 	    10
      6.2  Ecological Risks 	    12

7.0  Remedial Action Objectives 	    16

8.0  Summary of the Alternatives	    17

9.0  Evaluation of the Alternatives and the Selected Remedy.   18
      9.1  Overall Protection of Human Health and the
           Environment	19
      9.2  Compliance with Applicable or Relevant and
           Appropriate Reguirements (ARARs)  	   22
      9.3  Long-Term Effectiveness and Permanence  	   25
      9.4  Reduction in Toxicity,  Mobility, or Volume Through
           Treatment   	27
      9.5  Implementability   	    28
      9.6  Short-Term Effectiveness  	   28
      9.7  Cost	29
      9.8  State Acceptance	31
      9.9  Community Acceptance	31

10.0  Description of the Selected Remedy	31
      10.1  Surface Water	33
      10.2  Groundwater	35
      10.3  Source Materials 	   38

11.0  Statutory Determinations 	   42
12.0  Documentation of Significant Changes 	   54

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DECISION SUMMARY

1.0 Site Description

The Cherokee County Superfund site is located in the extreme southeast portion of the state of
Kansas and encompasses an area of approximately 115 square miles. This site is designated as a megasite
due to its large size and subdivision into several subsites and operable units. A wide variety of
response actions have been conducted to date. The Baxter Springs and Treece subsites (shown on Figure 1)
consist of two of the six subsites which make up the Cherokee County, Kansas Superfund site and are part
of the former Picher mining field which is centered near the town of Picher, Oklahoma. The Picher mining
field extended northward from Oklahoma into southeastern Kansas and was one of the most productive lead
and zinc mining areas in the United States. This area is part of the larger Tri-State Mining District
which covers approximately 500 sguare miles in southeast Kansas, southwest Missouri, and northeast
Oklahoma.

The surface area of the Baxter Springs subsite is approximately 17 sguare miles or 10,880 acres
while the surface area of the Treece subsite is approximately 11 sguare miles or about 7,040 acres. The
Baxter Springs and Treece subsites are underlain by mine workings with depths ranging from approximately
200 to 500 feet below the surface. It is estimated that 1,255 acres within these subsites are covered
with surficial mining/milling waste piles, tailings impoundments, and stream outwash tailings deposits.

These two discrete subsites are being addressed by a single Record of Decision (ROD) due to their
close proximity and similarity of wastes. However, as noted in the following paragraphs, the subsites
are contained within different watersheds or drainage basins and thus contribute contaminants to
different stream systems and receptors. This is an important point to note as the selected remedy
specifies certain differing actions for the two subsites as well as some common remedy components for
both subsites.

The Baxter Springs subsite is drained by Willow Creek, Spring Branch, and other small unnamed
drainages. These drainages flow predominantly to the east-southeast and discharge to the Spring River.
The Spring River eventually discharges into the Neosho River at the Grand Lake 0' the Cherokees in Ottawa
County, Oklahoma (see Figure 1). The state of Kansas has designated the lower portion of Spring Branch
as a critical habitat for nine threatened or endangered species. These species are listed in the
Remedial Investigation (RI) report and the Ecological Risk Assessment (ERA) report, which are available
in the Administrative Record.

The Treece subsite is drained primarily by Tar Creek, which exits the Kansas portion of the Picher
field near the town of Treece, Kansas and drains much of the Oklahoma portion of the Picher field. Tar
Creek discharges into the Neosho River near the town of Miami, Oklahoma (see Figure 1). The Treece
subsite has also been designated by the state of Kansas as a critical habitat for a threatened or
endangered species as discussed in the ERA. The Treece subsite is contiguous with the Tar Creek
Superfund site in Oklahoma.

The Baxter Springs and Treece subsites have been contaminated with hazardous substances as a
result of the mining and milling of lead and zinc ores. Hazardous substances, primarily lead, zinc, and
cadmium, are found in the surface water, sediments, soils, mine/mill wastes, and groundwater within these
subsites.

2.0 Site History

Discoveries of mineral deposits in Kansas are reported as early as 1870, when zinc deposits were
discovered near Galena. Discoveries of lead and zinc deposits from the Picher field date back to as early
as 1901 in the vicinity of Lincolnville, Oklahoma.

The first commercial production of lead and zinc ore from the Picher field was in 1904. Mining
operations continued in the Picher field through the 1950s, with the last large mining company closing
down underground mining operations in 1958. Smaller mining operations continued in the Picher field area
until 1970, when all mining essentially ceased. Since the late 1960s, the mill waste piles of the Picher
field have been actively guarried for commercial uses such as construction, concrete aggregate, railroad
ballast, highway and secondary road construction, and sandblasting.

The mining and processing activities conducted at these subsites, in addition to subseguent
weathering, use, and transport, have resulted in contamination of surface water, sediment, soil, and
groundwater with heavy metals. The U.S. Environmental Protection Agency (EPA) began environmental
investigations in the Picher field in 1984. EPA placed the Cherokee County Superfund site on the
National Priorities List (NPL) in 1983 pursuant to Section 105 of the Comprehensive Environmental

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Response, Compensation, and Liability Act  (CERCLA),  42 U.S.C. °9605.  The site encompasses the towns of
Galena, Baxter Springs, Treece, and Riverton, as well as the small rural areas of Badger, Lawton, and
Waco.

       EPA separated the Cherokee County megasite into subsites to initially focus and expedite the field
investigations and subseguent remediation of contaminant sources in the most heavily impacted areas.  The
six subsites are designated as Galena, Baxter Springs, Treece,  Badger, Lawton, and Waco  (see Figure 1).
These six subsites encompass the majority of the areas where physical disturbances are evident and thus
represent the major areas of past mining activities.  The Galena subsite was addressed initially due to
the potential for exposure of the largest population.  The Baxter Springs and Treece subsites were
subseguently addressed followed by preliminary evaluation of the Badger, Lawton, and Waco subsites.

3.0  Highlights of Conmunity Participation

       EPA Region VII encouraged public review and comment on the preferred remedial alternative by
providing the public with the proposed plan and supporting documents included in the Administrative
Record file.  In order to provide the community with an opportunity to submit written or oral comments,
EPA established a public comment period from August 18, 1994, to September 16, 1994.  This period was
extended for an additional thirty days to October 16, 1994 due to public interest.  A public meeting was
held on August 25, 1994, at 7:00 p.m. at the Community Center in Baxter Springs, Kansas, to present the
proposed plan, accept written and oral comments, and to answer guestions concerning the preferred
alternative.  At this meeting, representatives from EPA and the Kansas Department of Health and
Environment  (KDHE) answered guestions about the subsites and the remedial alternatives under
consideration.  Responses to the guestions and comments received during the public comment period are
included in the Responsiveness Summary, which is provided as Attachment #1 to this Record of Decision
(ROD) .   The decision for these two subsites is based on the information contained in the Administrative
Record file which is located at the earlier referenced repositories.

4.0  Scope and Role of Operable Units

       The six previously described subsites of the Cherokee County site are grouped into the following
operable units (OUs):  OU-1, Galena Alternate Water Supply; OU-3, Baxter Springs; OU-4, Treece; OU-5,
Galena Groundwater/Surface Water; OU-6, Badger, Lawton, and Waco; and OU-7, Galena Residential Soils.
One former OU (OU-2, Spring River)  no longer exists as the Spring River is encompassed by the other
existing OUs.  An "operable unit" is a term used by EPA to subdivide a site or subsite into parcels of
work.  It is simply a means for EPA to efficiently complete work at a large site in a step wise fashion.
Operable units are typically named and numbered.  The operable unit approach initially targeted impacted
groundwater used as a drinking water source near Galena, Kansas  (OU-1) and the subseguent remediation of
impacts to the groundwater and surface water (OU-5).  These actions were followed by addressing impacted
residential soils in the community of Galena (OU-7).  Activities at OU-1 and OU-7 also included early
removal actions which were followed by remedial actions.  Remedial actions at OU-1 and OU-5 are complete
while OU-7 cleanup work is ongoing.  The OU-6 effort will be the final action at the site due to the
rural area  (small potentially affected population) and small volume of wastes as compared to the other
areas.   This ROD addresses OU-3/OU-4, the Baxter Springs and Treece subsites.

       The Galena subsite response actions are consistent with the selected remedy for the Baxter Springs
and Treece subsites. Remedial actions at the Galena subsite were selected in two RODs issued in 1987 and
1989 and were performed by EPA.  The 1987 ROD reguired installation of a public water supply for
approximately 500 residences at the subsite while the 1989 ROD reguired remediation of impacts to
groundwater and surface water in the following manner:

       •      Selective placement of surface mine wastes to reduce human exposure and migration of
              contaminants into the groundwater and surface streams;

       •      Surface water diversions to prevent stream capture by mine shafts and subsidences;

       •      Surface recontouring to reduce surface water infiltration and ponding;  and

       •      Inspection of wells penetrating the Roubidoux aguifer,  and plugging or lining of these wells
              as  necessary to protect the deep aguifer.

       EPA implemented the remedial actions for the public water supply and the groundwater/surface water
cleanup using Superfund monies.  The public water supply installation  (OU-1) and the groundwater/surface
water cleanup (OU-5) are complete and now in the operation and maintenance phase.  EPA recovered partial
funding for these actions in subseguent bankruptcy and cost recovery cases.  These actions were completed
first due to the large amount of wastes near populated areas and the impact resulting from consumption of

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metals laden groundwater.

EPA initiated investigations at the Baxter Springs and Treece subsites in 1990 by issuing an
Administrative Order on Consent (AOC) , Docket Number VII 90-F-0010, dated May 8, 1990, to a group of
potentially responsible parties (PRPs). The PRPs include the following companies:

AMAX, Inc.;
ASARCO, Inc.;
• Eagle-Picher Industries, Inc.;
• Gold Fields American Corporation;
• NL Industries, Inc.;
• St. Joe Minerals Corporation (The Doe Run Co.); and
• Sun Company, Inc.

Under the terms of the AOC, the Respondents performed the RI, including the Human Health Risk
Assessment (HHRA), ERA, and FS for the Baxter Springs and Treece subsites. EPA subseguently developed a
technical memorandum, dated January 5, 1994, which recommended a remedial alternative and served as a
basis for a feasibility study addendum (FS Addendum) prepared by the Respondents. Respondents submitted
the FS Addendum in June 1994. The FS report, FS Addendum, and EPA's technical memorandum are included in
the Administrative Record, along with the RI, HHRA and ERA reports.

The selected remedy for the Baxter Springs and Treece subsites is consistent with the Galena OU-7
ROD in regard to the cleanup of source materials and residential areas. EPA completed a ROD for the
impacted residential areas of Galena (OU-7) in July 1996. This remedial action is currently underway
(1997) and is planned for completion in 1998. The OU-7 ROD provided for the excavation and disposal of
residential soils impacted by mining, milling, and smelting wastes.

5.0 Baxter Springs and Treece Subsite Characteristics

Past mining practices produced approximately 75 million cubic yards of mine and mill wastes within
these subsites, of which approximately 4.3 million cubic yards remain today. The surficial mine wastes
at the subsites also consist of development and waste rock that have little mineralization (non-milled
material). Mill wastes consist of the fine (tailings impoundment derived) and coarse grained (commonly
referred to as "chat") mill tailings that have elevated levels of metals. For purposes of this ROD, all
wastes, including development rock, waste rock, chat, and fine grained flotation impoundment tailings are
referred to as mine wastes. Since the surficial mine wastes were originally excavated from mineralized
strata, they contain minerals characteristic of the mining district, chiefly, galena and sphalerite. The
mine wastes contain heavy metals at concentrations above natural background soil levels. The metals
which are the contaminants of concern include cadmium, lead, and zinc; however, the mine wastes also
contain the following hazardous substances: arsenic; copper; mercury; and manganese. The predominant
focus is on lead, cadmium, and zinc because these constituents exceed acceptable risk management or
regulatory concentration levels and create unacceptable risks to human or ecological receptors.

The RI report for the Baxter Springs and Treece subsites indicates that contaminants, principally
heavy metals in the soils, surface mine wastes, shallow groundwater, sediments, and onsite surface water
bodies represent the principal threats to human health and the environment. The main routes of exposure
with respect to human health are through direct contact with and ingestion of the soil or surface mine
wastes, and potential uptake of contaminants through locally grown produce, beef, and dairy products.
Lesser potential routes of exposure include air and water media.

With respect to environmental impacts, the main concerns are direct uptake of contaminants from
water by aguatic organisms and the potential for impacting critical habitat for state listed, threatened,
or endangered species. The shallow groundwater, which is currently not being used as a source of
drinking water, is contaminated with hazardous substances, including lead, cadmium, and zinc.

The development rock is from shaft excavation and is mostly the nonmineralized overbearing
Pennsylvanian age shales and limestones. The waste rock is the oversized material from opening the
lateral drifts or tunnels. The development and waste rock cover about 18 acres within these subsites
(about 200,000 cubic yards) and are insignificant sources of the contaminants of concern compared to the
mill wastes.

The mill wastes represent the main source of hazardous substances at these subsites. The coarse
grained material known as "chat" represents the residual material from the jigging and tabling milling
processes. Chat normally ranges from about 1/64 to 3/8 inch in diameter. The metals in the chat are
primarily concentrated in the finer materials which generally make up 3 to 12 percent of the total
volume. The average concentrations of lead and zinc in the chat piles range from 360 to 1,500 parts per

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million (ppm) and 6,000 to 13,000 ppm, respectively.

The flotation tailings represent the fine residual materials which remain from the froth flotation
milling processes. These tailings are fine grained and are silt sized or smaller (finer than a 200-mesh
screen). Similar to chat, the metals are more heavily concentrated in the finer grained material. The
average lead concentration in flotation tailings is approximately five times higher than the
concentration in typical chat and ranges from 380 to 5,900 ppm. Zinc concentrations in flotation tailings
are also much higher than in chat and range from 3,800 to 64,000 ppm.

Most of the flotation tailings (90 percent) within these subsites occur within impoundments.
However, there are some tailings impoundments where the dikes have been eroded or overtopped, and the
tailings have washed into adjoining areas or streams. These outwash areas cover 27 acres in these
subsites and are a major source of contamination. At least eight areas within these subsites have
outwash tailings material in the streams which have been mixed with other stream sediments. Figure 2
depicts the various types of mine wastes at the Baxter Springs subsite that are addressed by the selected
alternative.

Soils in the immediate vicinity of the surface mine wastes have elevated levels of metals. This
is likely a result of several processes which include the following: transport of windblown dust from
all types of mining wastes; erosion from the chat and tailings areas; transport of contaminants via
surface water flows or groundwater seeps; and mechanical redistribution from chat guarrying operations.
All of the previously described types of mining wastes, bedrock, and soils may be commingled in various
combinations.

Two major aguifer systems, referred to as the shallow and deep aguifers, underlie these subsites.
The shallow aguifer is comprised of Mississippian age limestones which host the lead-zinc mineral
deposits that were mined at these subsites. Water from the shallow aguifer is not freguently used at
these subsites for domestic or livestock supplies because it is low yielding and the guality is generally
poor. Water from wells in the shallow aguifer is laden with calcium sulfate and regularly exceeds
secondary safe drinking water standards for iron, manganese, and sulfate. Water guality data from wells
located in the shallow aguifer in the non-mined area east of Baxter Springs indicate that the water is
potable; thus it is highly probable that past mining activities have degraded the water guality of the
upper most aguifer.

The deep aguifer occurs in lower Ordovician age sandy dolomite and provides the principal source
of water for public, industrial, domestic, and livestock supplies at these subsites and surrounding
areas. Water in the deep aguifer contains calcium bicarbonate or calcium magnesium bicarbonate and is
adeguate for most uses. East of the Spring River, the deep aguifer water generally has less than 500
milligrams per liter (mg/1) of dissolved solids with minor detectable concentrations of trace metals.
West of the river, the dissolved solids concentrations increase up to 1,030 mg/1 and concentrations of
trace metals are similar as to the east. While the deep aguifer is predominantly clean and not impacted
by mine wastes, the RI report concluded that it could potentially become impacted by faulty well seals or
leaky casings in wells installed within the lower aguifer. The available data indicates that mine water
has not migrated from the shallow aguifer to the deep aguifer through the intervening geologic strata.
The intervening strata was thus determined to be an adeguate confining unit or aguitard.

The RI report assesses the metals loading contributed to the Spring and Neosho Rivers by the
streams and creeks in the Baxter Springs and Treece subsites. The combined zinc loading to the Spring
River from Willow Creek and Spring Branch at the Baxter Springs subsite is approximately 24,000 pounds
per year. The zinc load contributed to the Neosho River from the Tar Creek drainage basin within the
Treece subsite is estimated at 220,000 pounds per year.

Air sampling conducted during the investigations at these subsites indicates that national
standards for air guality are not exceeded. The highest recorded concentration of lead was 0.2
micrograms per cubic meter (ug/m 3), which is well below the national standard of 1.5 ug/m 3.

6.0 Summary of Site Risks

In conjunction with the Baxter Springs and Treece RI, a HHRA and an ERA were conducted by PRPs to
evaluate the risks to human health and the environment that could result from exposure to hazardous
substances. These reports which detail the screening level type assessments are contained within the
Administrative Record file.

These screening level risk assessments were prepared using data from the subsites and from
assumptions regarding maximum exposures that could be reasonably expected to occur for an individual or
population at or near the subsites. This exposure is defined as the Reasonable Maximum Exposure (RME).

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The individual (or population in the case of the ERA) most likely to be exposed to hazardous substances
is defined as the RME individual. The RME individual is used as a reference point in the risk assessment
process to help determine what health related risks are present. The RME population is used as a
reference point in the ERA in order to help determine the risks that are present.

6.1 Human Health Risks

When evaluating the risk resulting from exposure to hazardous substances for people at or near a
Superfund site, EPA considers the exposure to be unacceptable if it results in a hazard index (HI)
greater than one. A HI is a summary for a specific chemical across all pathways or a summary of all
hazardous guotients (HQs) for a residential scenario. A HI of one or more indicates that adverse health
effects are possible. Human health effects related to lead are assessed using EPA's Integrated
Uptake/Biokinetic Model (IEUBK). The risk associated with lead is considered unacceptable if the IEUBK
model predicts that lead levels in blood exceed 10 micrograms per deciliter (ug/dl) for the hypothetical
child at a freguency greater than 5%. Children under six years of age are considered the major
population at risk.

A lead and cadmium exposure study was completed by the Agency for Toxic Substances and Disease
Registry (ATSDR) in January 1996 at the Cherokee County site. The study targeted the Galena subsite
which is adjacent to the Baxter Springs and Treece subsites. The ATSDR exposure study demonstrated a
10.5% exceedance of blood lead levels above 10 ug/dl for the hypothetical child. The ATSDR study
consisted of the actual collection of children's blood lead samples followed by analyses and
comprehensive in-home assessments of several variables.

The IEUBK model was used to simulate exposure to lead and bases its calculations on children as
they represent the most sensitive receptor group. If a given exposure does not pose a problem to
children living in these subsites, then adults are assumed not to be significantly impacted. The
complete IEUBK data output for the Baxter Springs and Treece subsites is presented in Appendix E of the
HHRA report. The results from an IEUBK model run for OU-7 of the Cherokee County site are provided in
Attachment #2 of this ROD. The attachment also contains an adult lead model run for the Baxter Springs
and Treece subsites. The information in Attachment #2 was prepared by EPA. The IEUBK data in the HHRA
(Appendix E) was prepared by the PRPs. The EPA models include institutional control assumptions and site
specific information.

The results predicted by the IEUBK model indicate that the concentrations of lead currently
present in soils at these subsites present an unacceptable risk to the children living in residences
located on or near mine wastes. The concentration of lead in residential soils is the main concern for
the uptake of lead and projected elevated blood lead levels under both current and future residential
land use scenarios.

The HHRA report discusses the His and HQs relating to human exposure to onsite soil, water, and
air, as well as human ingestion of beef, milk/dairy products, and produce. A HQ is a comparison of site
specific chemical intake versus established intake levels that do not pose a health threat. His and HQs
estimate potential health risks. Soil pathways generally dominate the risk characterization for the
Baxter Springs and Treece subsites. Except in cases where residences are located on or near mine wastes
within the Baxter Springs and Treece subsites, significant lead exposures are potentially unlikely to
occur under current site conditions. Based on the onsite data and model default values, the human uptake
of lead from air, water, and diet have a lesser impact on total lead uptake when compared to potential
soil contributions.

These results are based on the premise that impacted groundwater is not being consumed and that
recreational activities on/in impacted streams and bodies of water are not occurring. Although the
impacted uppermost aguifer is not known to be utilized as a primary drinking water source at the present
time, it may contaminate the lower aguifer, which is a primary water source, and it is also possible that
shallow aguifer domestic or agricultural wells could be drilled in the future. Additionally, there may be
rural users of the uppermost aguifer that have not been identified. Risks are also associated with the
contact of surface water through actions such as boating, swimming, or fishing as well as impacts from
the consumption of contaminated fish. In summary, non-soil pathways do not have a substantial known
impact on predicted blood lead levels, but groundwater and surface water may be a pathway of concern
under certain circumstances.

Lead is the only demonstrated human health risk at the site. However, cadmium has the potential to
create an unacceptable risk resulting from the ingestion of vegetables or groundwater. Vegetables have
been demonstrated to readily uptake cadmium and thus pose a potential health threat. Many studies at
this multiple operable unit megasite have conclusively demonstrated human health risks. Additional human
health risk studies can be found in the Administrative Records for OU-1, OU-5, and OU-7 of the Galena

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subsite.

6.2 Ecological Risks

Data collected during the investigations of both the Baxter Springs and Treece subsites indicate
the contaminants of concern for ecological risk include cadmium, lead, and zinc. While zinc is not a
contaminant of concern (COG) with respect to human health, it is a concern for ecological risk in
addition to cadmium and lead. Cadmium, lead, and zinc exceed the Ambient Water Quality Criteria (AWQC)
established by the Clean Water Act (CWA) in the streams of both subsites.

For aguatic organisms, a site specific surface water cleanup goal for each metal contaminant was
derived by calculating a toxicity reference value (TRV). TRVs were developed by using site specific
variables (e.g., hardness, pH) and are appropriate for use in calculating ecological risk because they
are based on species found or expected to be present in these subsites. The following table compares the
TRVs and AWQC:

Contaminant AWQC - Chronic TRVs
of Concern (mg/1) (mg/1)

zinc 0.10599 1.423
cadmium 0.00113 .008
lead 0.00318 .027

The TRVs were compared to concentrations of the COCs in surface water at various exposure
locations (stream or pond sampling stations). A ratio between the actual surface water concentration and
the TRV was then calculated to assess the risk to the aguatic environment. This ratio is referred to as
the toxicity guotient (TQ). For ecological risk, EPA generally considers risk to be unacceptable if the
TQ is greater than one. A TQ of one or more indicates that adverse ecological effects are possible.

The investigation of these subsites included analysis of streams and ponds, which focused on
assessing the risk to aguatic life utilizing the TRVs. The streams assessed included Tar Creek/Tar Creek
Tributary (draining the Treece Subsite), and Spring Branch/Willow Creek (draining the Baxter Springs
subsite). Refer to Figures 3 and the earlier text discussing the two separate subsites and associated
watersheds or drainage basins that are addressed by this ROD.

Fish populations in lower Tar Creek within the Treece subsite were low, likely due to high zinc
concentrations and marginal physical habitat. The TQ for zinc, based on the ratio of the TRV to average
zinc concentrations in Tar Creek, was six. Toxicity guotients for the other metals were less than one.

Metal concentrations in Spring Branch (Baxter Springs subsite) indicate the potential for adverse
effects to occur based on TQs for cadmium and zinc at values of ten and seven, respectively. Fish were
collected during field surveys which yielded different age classes of only a single species. This may
indicate that this single species is reproducing in the creek. However, this data is incapable of
evaluating chronic, sub-lethal effects which are more significant to the viability of subsite species,
including fish, than the acute effects evaluated. Additional factors such as acclimation of the aguatic
species, speciation/bioavailability of the COCs, and freguency and pattern of occurrence of toxic
conditions may be masking the toxicity of the metals of concern. Thus, while some field data may
indicate that certain limited fish populations are seemingly tolerant of adverse conditions, the TQs
indicate that non-acclimated organisms would be adversely affected. This condition limits the
introduction and establishment of organisms in the affected habitats and serves to restrict the
ecological structure and function of the system. This results in fewer and fewer types of organisms and
less resilience in their trophic relationships.

Although the aguatic habitat in Spring Branch (Baxter Springs subsite) was rated as fair, this
drainage is entirely contained within an area impacted by mining. The RI report indicates that seepage
from Ballard Pond, currently used by a chat reuse facility, is likely a major source of cadmium to Spring
Branch. Fish were not observed in Ballard Pond, which had a cadmium TQ of ten, and Pond TP-7 which had
TQs for iron and lead exceeding one. The Ballard Pond is further discussed in the RI report.

Mean TQs for cadmium, lead, and zinc in Willow Creek (Baxter Springs subsite) were less than one,
however, it should be noted that AWQC are exceeded for cadmium, lead, and zinc. Willow Creek drains the
northern portion of the Baxter Springs subsite and the upper segments of the creek are normally dry
during the summer. An additional Baxter Springs subsite factor that must be taken into consideration is
mine shaft discharge effects. The Bruger Mine shaft occasionally discharges groundwater to Willow Creek,
and when discharges occur, zinc concentrations in Willow Creek likely exceed a TQ of 1. The Bruger shaft
is further discussed in the RI report.

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The investigation conducted at both subsites also focused on identifying risk to terrestrial
organisms. Three key site-specific species were selected to represent the terrestrial receptor groups at
these subsites. The species selected were the barred owl, red tailed hawk, and mink. For terrestrial
organisms, the potential for toxic effects was evaluated by comparing the No Observed Adverse Effect
Level (NOAEL) data from the literature (for the same or similar organisms) to contaminant dose estimates
for the species at these subsites. The Lowest Observed Adverse Effect Level (LOAEL) data were used when
NOAEL data were not available. To guantitatively estimate doses, it was assumed that the terrestrial
receptors were exposed to mine related metals by inhalation of fugitive dust, ingestion of mine wastes
and soils, ingestion of surface water, and ingestion of vegetation or prey. The worst case and RME
scenarios were used. Worst case was defined as the highest exposure that is reasonably expected to occur
at a subsite and was based on using a combination of conservative (i.e., high bias) exposure assumptions
and upper bound (95th percentile) data. The RME scenario used less conservative, more site-specific
exposure assumptions and arithmetic mean concentrations of the contaminants. The exposure assumptions
and exposure point concentrations (EPCs) used to guantify intakes are presented in detail in the ERA
report.

Toxicological data measuring the chronic effect of metals in the key terrestrial species
identified for the subsites were not available, but data for other related species were available.
Therefore, toxicity data for surrogate species were used. LOAELs for surrogate species were used, along
with uncertainty factors, to approximate TRVs for cadmium, lead, and zinc for the three key receptors.
The TRVs represented the predicted no-adverse-effect dose. The dose calculations for all terrestrial
receptors are presented in Appendix A of the ERA, and the exposure/intake assumptions are presented in
Section 5 of the ERA report.

Results of the toxicity assessment for mink indicate that chronic adverse effects from exposure to
cadmium, lead, or zinc are possible, since the worst case and RME TQs were egual to or slightly higher
than one (range of one to three). These data indicate that terrestrial species which consume fish will
likely experience adverse chronic effects from exposure to cadmium, lead, or zinc. The calculated TQs
for two raptors were all less than one.

In summary, the ERA indicates that there is a significant and unacceptable risk to aguatic
organisms present at these subsites. The risk to terrestrial organisms that eat fish is also considered
to be unacceptable. Additionally, a number of assumptions in the ERA result in an underestimated level
of risk. Examples of the under estimating of risk for aguatic receptors include the following: TQs were
calculated with LOAELs instead of NOAELS which are approximately ten fold less stringent; mean chronic
LOAELs were calculated from a range of values rather than using the most conservative LOAEL; sediment was
omitted as an exposure pathway; concentrations reflecting potential for adverse effects on individuals
were disregarded; and dissolved metals concentrations were adjusted using ratios based on stream-specific
sampling data rather than assuming 100% availability of total recoverable metals. Underestimated levels
of risk for terrestrial receptors include the same factors as for aguatic receptors with the addition of
the most-likely-exposure (MLE) intake being estimated rather than using the RME intake. When considering
the non-conservative ERA characterization yielded a determination of significant and unacceptable risk,
this only serves to foster and emphasize the need for remedial action to be implemented.

7.0 Remedial Action Objectives

During the FS process, media specific Remedial Action Objectives (RAOs) were developed to address
the unacceptable risks associated with each media and exposure pathway. These RAOs are goals for
remediation that can be addressed through either reduction of exposures and/or reductions in contaminant
levels. Two RAOs were developed for surficial mine wastes, four RAOs were developed for groundwater, and
two RAOs were developed for surface water. These RAOs are presented on Table 1.

The RAOs were developed from the extensive amount of site specific information obtained during
various phases of work conducted at the site. The RI provided site characterization information
detailing the nature and extent of contamination in all media (groundwater, surface water, sediments,
soil, mine wastes, air), the transport and exposure pathways of the various contaminants through the
various media, and the detailed physical properties and nature of the media and contaminants. The
potential risks and transport pathways for the COCs were evaluated in the HHRA for human receptors and
the ERA for non-human (plants, animals, organisms) receptors or ecological assessment endpoints "biota".
The RI, HHRA, and EGA are contained within the Administrative Record for the subject site.

The RAOs for the surficial materials or mine wastes (as presented on Table 1) are designed to
prevent direct human contact with the wastes and thus eliminate the inhalation, ingestion, or dermal
absorption of the site specific COCs. The elimination of the direct contact threat will ensure that the
human health risks are reduced or eliminated. Specifically, the RAOs for source materials or mine wastes
are designed to prevent exposures that result in excess cancer risks greater than l.OOE-06, a

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non-carcinogenic HI greater than 1.0, and elevated blood lead levels greater than 10.0 ug/dl for more
than five percent of the child population. These RAOs also encompass soils that may be impacted by or
contain mining wastes and also reduce or eliminate contributions to the groundwater and surface water
systems. Additionally, the RAOs address ecological risks associated with the exposure of biota to metal
contaminants.

The groundwater RAOs (see Table 1) are designed to prevent human and ecological exposure to
contaminated groundwater as well as groundwater contributions to surface water that would result in
unacceptable human and ecological risks. The groundwater RAOs will prevent the migration of contaminants
from the upper shallow saturated zone (Boone aguifer) to the lower Roubidoux aguifer and thus prevent
human health risks and exceedances of ARARs for the lower aguifer. The groundwater RAOs prevent the
additional degradation of the Tar Creek Superfund site in Oklahoma and also are consistent with the past
actions implemented by EPA Region VI at the Oklahoma Tar Creek Superfund site.

The RAOs for surface water (see Table 1) are also designed to prevent direct human contact with
contaminants by eliminating ingestion, absorption, and inhalation pathways. The surface water RAOs will
prevent the transport of contaminants through the streams (including stream sediments) in order to reduce
or eliminate excessive ecological risks in the Neosho and Spring Rivers. The RAOs will prevent the
exposure of aguatic biota to contaminants in order to reduce or eliminate excessive ecological risks.

8.0 Summary of the Alternatives

Eight basic alternatives were developed to address the RAOs in the FS report. Several of these
alternatives included variations (sub-alternatives) for a total of 18 individual alternatives. The
variations were designated by lettering such as 4a, 4b etc. Of these 18 alternatives, eight became
candidates for additional detailed analysis. None of these original 18 FS alternatives or
sub-alternatives were ultimately selected.

The EPA and the state of Kansas reviewed the PRP generated FS and initially proposed a modified
version of Alternative 5a as a viable approach. Alternative 5a was not one of the eight alternatives
carried forward for detailed analysis in the PRP derived FS. EPA and the state provided the PRPs with a
modified version of Alternative 5a, known as "Modified 5a". In response to this input by EPA and the
state of Kansas, the PRPs prepared an FS Addendum which detailed an alternative based on the Modified 5a
Alternative and the original FS Alternative 3. This alternative is described in the FS Addendum and is
designated as Alternative 3b. EPA has selected this approach, Alternative 3b, as provided in the FS
Addendum, as the remedy for the Baxter Springs and Treece subsites.

Alternatives were analyzed based on the nine criteria for remedy selection in accordance with the
National Contingency Plan (NCP). For purposes of clarity, only the selected alternative, 3b, and
Alternatives 3, 5a, and Modified 5a will be discussed in the following evaluation and comparison
sections. Table 2 provides a comparison of these four alternatives. It should be noted that the cost
information on Table 2 is from the FS and FS Addendum documents and thus represents 1994 dollars. The FS
was actually completed in 1993 and the FS Addendum in 1994; thus, all historic costs are considered to be
in 1994 dollars for clarity. Updated costs for the selected alternative are presented later in this
document. Attachment #3 contains a description of the original 18 alternatives for informational
purposes. The FS and FS Addendum contain additional information discussing the original 18 alternatives,
the Modified 5a Alternative, and the selected 3b Alternative.

9.0 Evaluation of the Alternatives and the Selected Remedy

The NCP, 40 C.F.R. Section 300 et. seg., reguires EPA to evaluate selected remedial alternatives
against nine criteria. A selected or preferred alternative must satisfy all nine criteria before it can
be implemented. The first step is to ensure that the selected remedy satisfies the threshold criteria.
The two threshold criteria 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 and not
evaluated further. However, compliance with ARARs may be "waived" if site specific circumstances warrant
such a "waiver" as described in Section 300.430(f)(1)(ii)(C) of the NCP, 40 C.F.R. °
300.430(f)(1)(ii)(C). As described in detail in Section 9.2 herein, the selected remedy anticipates that
certain ARARs will be waived based on technical impracticability.

The second step is to compare the selected remedy 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 selected remedy on the basis of modifying criteria.
The two modifying criteria are state and community acceptance. The local community and the state of
Kansas have accepted and concurred with the selected remedy.

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9.1 Overall Protection of Human Health and Environment

This criterion addresses whether a remedy provides adequate protection and describes how risks
posed through each pathway are eliminated, reduced, or controlled through treatment, engineering
controls, or institutional controls.

The selected remedy, 3b, is summarized on Table 3 (also see Figure 2) and discussed in Section 10
of this document. It should be noted that this remedy specifies differing actions for the two separate
subsites that are addressed by this single ROD. Most of the alternatives consisted of differing
approaches for the two subsites which are located within different watersheds or drainage basins (see
Figure 3). It should be noted that this ROD is primarily an ecological remedy designed to protect
surface water, groundwater, and ecological receptors. However, there is a human health component
associated with residential soils potentially contaminated by mining wastes. For estimating purposes, 25
residential properties are assumed to represent the number of affected properties. It should be noted
that no properties have currently been determined as requiring cleanup, but the characterization is
somewhat limited. Future remedial design investigations will provide additional information for the
residential remedial action component.

The selected remedy primarily focuses on ecological protection of the environment through cleanup
actions at the Baxter Springs subsite to reduce metals loading to Spring Branch and Willow Creek and
through actions at both the Baxter Springs and Treece subsites that include the implementation of
institutional controls and plugging of abandoned deep wells. Implementation of the selected remedy will
reduce the risks identified for terrestrial organisms that consume fish within the Baxter Springs
subsite, which were the primary ecological group identified at risk. Protection of aquatic organisms in
the Baxter Springs subsite will be accomplished by reducing or eliminating metals loading to Spring
Branch and Willow Creek through removal and capping of source materials. The RAOs for surficial
materials are achieved at the Baxter Springs subsite by preventing terrestrial biota from exposure to
metals contaminants in surficial materials. The groundwater RAOs are achieved by performing engineering
actions in the Baxter Springs subsite and by implementing institutional controls and plugging abandoned
deep wells in both the Baxter Springs and Treece subsites. Additionally, the groundwater RAOs are
achieved by implementing a consistent remedial approach at the Baxter Springs and Treece subsites which
compliments, and is supplemental to, the actions taken at the Tar Creek site in Oklahoma. The surface
water RAOs are also achieved by reducing the exposure of aquatic biota to metals impacted surface waters
at the Baxter Springs subsite.

In summary, the selected remedy will protect the earlier referenced species of concern by removing
or capping the most highly impacted mine wastes and by reducing the metals loading to surface water
bodies. These species are impacted by contact or consumption of metals laden water, or by consumption of
other species which have been impacted by mine wastes. The remedy provides protectiveness by removing or
capping and revegetating the most impacted wastes, and since wastes which are in contact with surface
water bodies are prioritized for actions, protectiveness is also provided by reducing the loading of
metals to surface water. The habitat will thus ultimately be greatly improved with only a required
short-term disturbance of impacted habitat areas in order to complete the engineering actions.

This remedy will provide protection of human health by remediating current residential yards
situated on or near mine wastes if these yards exceed EPA established action levels. Future residents
will be protected through the implementation of institutional controls that will prohibit building on
soils or mine wastes which exhibit concentrations of contaminants in excess of action levels. This will
achieve the RAOs for surficial materials by preventing direct human contact by ingestion and/or
inhalation of the site specific contaminants. Also, the institutional controls will prohibit use of the
shallow groundwater for human consumption. The selected remedy will provide protection of the deep
aquifer by plugging poorly constructed or abandoned wells installed within the deep aquifer. This aspect
of the remedy achieves the groundwater RAOs by preventing risks associated with the potential domestic
use of metals impacted groundwater and also prevents the downward migration of contaminated groundwater
from the upper Boone aquifer to the lower Roubidoux aquifer. The remedy also achieves the surface water
RAOs by preventing the transport of metals impacted sediment to off-site areas by reducing or eliminating
the contributions from on-site sources.

The selected remedy does not include source containment/stabilization actions to improve surface
water quality in Tar Creek due to technical impracticability. The technical impracticability aspects are
discussed in Sections 10.0 and 11.1, herein, in addition to Attachment #4. However, considering all of
the threats posed by conditions at both subsites, the risk reduction that will occur due to actions that
will be taken to address them, and consistency with past actions at the Region VI Tar Creek site, the
selected remedy does provide optimum overall protection of human health and the environment.

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All four comparison alternatives for the Baxter Springs subsite (3, 3b, 5a, Modified 5a) provide
protection of the aquatic environment through engineering controls and provide for a reduction of aguatic
risk by removal of mine waste piles and impoundments in addition to excavation of outwash tailings in the
Baxter Springs subsite streams. Of the four Table 2 Alternatives, Alternative 5a offers the highest
degree of aguatic protection through remediation of the largest sources of mine wastes that contribute
metals loading to the subsite streams. Modified Alternative 5a is the next most protective remedy
(overall) as it includes less mine waste pile and impoundment remediation and less channel improvements
than Alternative 5a. Alternative 3b (the selected remedy) is more protective of the Baxter Springs
subsite than the other three Alternatives (3, 5a, and Modified 5a) since it includes the greatest amount
of actions (see Table 2) for the Baxter Springs subsite. The FS addendum estimates that Alternative 3b
will reduce or eliminate 85% of the metals loading to the Baxter Springs subsite. Volume reductions
of lead, cadmium, and zinc are estimated at 116, 115, and 15,200 pounds per year, respectively to the
Spring River. However, Alternative 3b does not include cleanup actions for the Treece subsite due to
technical impracticability.

All alternatives presented in the FS report and addendum, except Alternative 1 (No Action),
address the potential current human health risk by remediation. The 5a, Modified 5a, and 3b Alternatives
provide protection of human health through the implementation of institutional controls on the use of
groundwater and control future residential development on mine wastes. Alternatives 3, 3b, 5a, and
Modified 5a also provide some protection of human health by the remediation of varying amounts of mine
wastes in existing residential areas and undeveloped mine waste areas.

9.2 Compliance with Applicable or Relevant and Appropriate Requirements (ARARs)

This criterion addresses whether the selected remedy will meet ARARs of federal and state laws.
Compliance with chemical-specific, location-specific, and action-specific ARARs is required of the
selected remedy unless a waiver of an ARAR is justified. Based on conditions at both subsites, a
justification for a waiver of certain ARARs is provided in this ROD.

The selected remedy will meet all federal and state location-specific and action-specific ARARs
relating to the Baxter Springs subsite. These ARARs are listed in Section 11, herein. The
action-specific and most of the location-specific ARARs relating to the Baxter Springs subsite are not
required for the Treece subsite because the components of the selected remedy for the Treece subsite are
different, which include residential yard cleanup, if any, and institutional controls.

Action-specific ARARs for the Baxter Springs subsite include the Clean Water Act (CWA) regulations
on storm water discharge from industrial activities such as inactive mining sites. Surface mine wastes
contribute metals loading to the surface water bodies as a result of runoff generated by infiltration
events as well as from erosion of the mine waste piles by subsite streams. The 5a, Modified 5a, 3, and
3b Alternatives (in Baxter Springs only) meet the requirements of the CWA regulations by reducing water
pollution from runoff.

Chemical-specific ARARs are waived at both subsites due to technical impracticability.
Chemical-specific ARARs are technically impractical to achieve because available technologies cannot
achieve cleanup levels within a reasonable time frame due to limitations imposed by site characteristics,
such as karst-like topography, mine voids, enormous mine waste piles and other sources of contaminants
outside these subsites (adjacent mine waste areas). It is technically impracticable for cleanup actions
at both subsites to achieve Safe Drinking Water Act standards in the shallow aquifer nor can the CWA
standards be achieved in surface waters.

None of the alternatives evaluated in the Feasibility Study met chemical-specific ARARs
established by the Safe Drinking Water Act (SDWA) and the CWA. These ARARs are listed in Section 2 of
the FS Report. The NCP, 40 C.F.R. °300.430(e)(2) and Section 121 (d) of CERCLA, 42 U.S.C. °9621(d),
require that remedial actions achieve a cleanup level equivalent to the Maximum Contaminant Level Goals
(MCLGs) or action levels established under the SDWA and the AWQC established under the CWA, where such
goals or criteria are relevant and appropriate under the circumstances. The AWQC established pursuant to
the CWA are relevant and appropriate cleanup standards for protection of surface water at these subsites
but, require a waiver based on technical impracticability as discussed below.

Residents in the Baxter Springs and Treece subsites are served by public water districts and the
shallow groundwater is not typically used for drinking water due to its poor taste therefore, MCLGs are
not relevant and appropriate cleanup levels under the circumstances. The Maximum Contaminant Levels
(MCLs) promulgated under the SDWA are relevant and appropriate for remediation of the shallow groundwater
at the Baxter Springs and Treece subsites because the shallow groundwater may be used for water supply in
the future and there may potentially be a limited number of unidentified rural residents that currently
utilize the uppermost aquifer. MCLs are achieved in the current public water supply systems for the

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residents of the Baxter Springs and Treece subsites.

A waiver of the chemical-specific ARARs for the Baxter Springs subsite and the Treece subsite is
reguired based on technical impracticability. The evaluation of cleanup technologies in the FS and FS
Addendum indicate that the remedial technologies evaluated are not capable of achieving these ARARs
within a reasonable time frame due to limitations imposed by site characteristics. The karst-like
(conduit flow) geology and numerous mine voids at these subsites, in addition to the several sguare mile
areal extent (28 sguare miles for both subsites), effectively eliminate the use of typical engineering
controls for cleanup of the contaminated shallow aguifer. In addition, every mine waste pile that
contributes heavy metal contamination to the surface waters cannot be removed from the subsites.
About 4.3 million cubic yards of surface mining wastes contribute to surface water contamination at these
subsites. No place exists that could practically handle that volume of mine waste nor would it be
practical to excavate or handle that volume of wastes.

Further, chemical-specific ARARs for the Treece Subsite cannot be achieved in a way that would be
compatible with the completed actions at the contiguous EPA Region VI Tar Creek Superfund site. It would
be inordinately costly to remediate Tar Creek at the Treece subsite, and if such remediation were
performed, the creek would be re-contaminated as it flows from Kansas into Oklahoma. In 1985, the EPA
Selected Remedy for the Tar Creek Superfund site in Oklahoma determined that the Oklahoma portion of Tar
Creek is irreparably damaged due to historic mining operations (no beneficial use designation). Thus,
the Region VI remedy allows millions of tons of mining wastes to remain on the surface, which continues
to contaminate Tar Creek. The total cost for Alternative 3b, the Selected Remedy, at the Baxter Springs
and Treece subsites is approximately 7.1 million dollars (1997 estimate). The additional total costs for
remediation of Tar Creek at the Treece subsite is estimated at approximately 65.5 million dollars, which
is considered inordinately costly (1994 dollars). The total present worth value of the comprehensive
remedy for both subsites was estimated at approximately 79 million dollars in 1994 (total estimated costs
of 93.2 million dollars). The additional 65.5 million dollars for Treece subsite actions would improve
the water guality in Tar Creek. However, it is uncertain whether, even if remediated, Tar Creek would
achieve AWQC standards under the Clean Water Act.

9.3 Long-Term Effectiveness and Permanence

This criterion addresses residual risk and the ability of a remedy to maintain protection of human
health and the environment over time, after remedial action goals have been completed. Factors that are
considered include both the magnitude of residual risk remaining after implementation as well as the
adeguacy and reliability of controls used to manage treatment residuals or untreated wastes.

Long-term protection of the aguatic environment will be achieved by the selected remedy in the
Baxter Springs subsite through reduction of metals loading to subsite streams. Outwash tailings will be
excavated and placed in tailings impoundments, mine waste piles will he contoured and vegetated, caps on
source materials will be maintained to ensure permanence, and the wastes will be placed above the
saturated zone. In addition, stream diversion structures will be constructed and maintained to ensure
adeguate permanence and long-term effectiveness of the remedy. These actions will provide permanent,
long-term protection of species of concern as well as their habitat. The selected remedy does not
include engineered controls in the Treece subsite (Tar Creek), as based on a technical impracticability
determination, as well as a desire to be consistent with actions conducted by the state of Oklahoma and
EPA Region VI at the adjacent Tar Creek site.

Alternative 3 includes remedial action to reduce risk to the aguatic environment, but will not
provide adeguate effectiveness because large chat piles, excavated chat areas, and tailings impoundments
will not be remediated (see Table 2). Alternative 3 differs from the selected alternative by only
reguiring removal of outwash material. EPA believes that the subsite streams will ultimately become
recontaminated after remedial actions proposed in Alternative 3 are completed since significant sources
near the streams will not be remediated. Alternatives 5a and Modified 5a are not as comprehensive in the
Baxter Springs subsite but do include engineered actions for the Treece subsite. However, EPA has
determined that it is technically impracticable and inconsistent to perform engineered actions for Tar
Creek at the Treece subsite. The selected remedy (3b) addresses outwash material, tailings impoundments,
and selected mine waste piles.

The selected remedy, 3b, will provide long-term and effective protection of human health by
eliminating human exposure to the mine wastes and the contaminated shallow groundwater through
implementation and maintenance of engineering and institutional controls (ICs) and the remediation of
residential yards if deemed necessary. Again, 25 residential properties are currently estimated since no
properties have been identified due to limited residential characterization to date. Alternatives 3, 5a,
and Modified 5a also specified similar actions with regard to potential human health issues. If ICs are
not put in place and maintained into perpetuity, the selected alternative will not provide permanent

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protection. However, EPA anticipates that a financial fund, included as a recommended component of the
selected alternative and described in detail in the FS report, will encourage maintenance and enforcement
of the ICs. The financial fund portion of the FS is provided in Attachment #5. Additionally, EPA is
continuing health education activities throughout the county as part of several overlapping remedial
actions completed at the Cherokee County, Kansas megasite.

Alternatives 5a, Modified 5a, and 3b will provide long-term effectiveness since significant
sources that contribute metals loading to the subsite streams will be remediated. Alternative 3 does not
achieve long-term effectiveness. The additional scope of Alternatives 5a and Modified 5a do not provide
greater protectiveness than Alternative 3b. Tar Creek enters the Neosho River in Oklahoma and the Neosho
River meets TRVs. Given that the majority of Tar Creek impacts occur in Oklahoma, the Neosho River meets
TRVs, and Tar Creek in Oklahoma is designated as non-recoverable (no beneficial use designation), any Tar
Creek actions in Kansas would not be deemed to result in greater protectiveness or be technically
practicable. Even the 93.2 million dollars (1994) FS Alternative 8a would not achieve TRVs in the entire
Tar Creek drainage.

9.4 Reduction in Toxicity, Mobility, or Volume Through Treatment

This criterion addresses the degree to which a remedy employs recycling or treatment to reduce
toxicity, mobility, or volume of the contaminants present at the site. This also includes how treatment
is used to address the principle threats posed by the site.

Given the size (28 square miles) and magnitude of the volume of wastes present in these subsites,
estimated to be 4.3 million cubic yards, treatment of the wastes is impracticable. The selected remedy
does not utilize treatment technologies to reduce the toxicity, mobility, or volume of the wastes, but
will, however, reduce the toxicity and mobility of contaminants that threaten subsite streams by
excavating outwash materials and capping the mine wastes. A reduction of toxicity and mobility will also
be accomplished through construction of diversion structures and channel improvements to eliminate
erosion of the waste piles as well as draining, filling, recontouring, and revegetating selected tailings
impoundments. Additionally, remediation of the Bruger shaft discharges also will reduce the
mobility/transport of metals contamination in the groundwater to the surface water. Remediation of
residential areas, if required, will also reduce toxicity. Treatment methods and waste volume reduction
were not considered practical and were not contained within any evaluated remedy.

Alternative 3 reduces the mobility of wastes available for exposure to aquatic organisms, but does
not effectively eliminate the exposure. Alternatives 5a, Modified 5a, and 3b reduce the mobility of mine
wastes to levels that would result in protection of both people and the environment. Alternative 3b
provides the greatest mobility reduction for the Baxter Springs subsite while Alternatives 5a and
Modified 5a provide greater overall reductions since they include engineered actions for Tar Creek
(Treece subsite). However, the greater overall reductions afforded by 5a and Modified 5a (Treece
subsite) do not increase protectiveness.

9.5 Implementability

This criterion addresses the technical and administrative feasibility of the selected remedy,
including the availability of materials and services. The difficulty of undertaking additional action,
if necessary, is also assessed.

The selected remedy is anticipated to be fully implementable. The engineering controls involve
standard earth moving, capping, and construction techniques commonly employed. Institutional controls are
commonly used at Superfund mining sites due to the unusually large volume of wastes requiring cleanup and
the large areas contaminated by mine wastes. The EPA and KDHE will assist in implementation of the ICs
by providing and support to local communities on adoption and implementation of ICs. A financial fund,
proposed as part of the remedy, will provide incentive for establishment and maintenance of ICs.

All Alternatives evaluated in the FS report are considered to be fully implementable since they
are general commonly used construction techniques.

9.6 Short-Term Effectiveness

This criterion addresses the period of time needed to achieve the remedial action, and any adverse
impacts to human health and the environment that may be posed during implementation of the remedy.

It is anticipated that the proposed remedial action would be completed in approximately one year
followed by continued long-term operation and maintenance (O&M). Any potential short-term risk to
workers, the communities, or the environment would be readily preventable. Impacted habitat will be

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disturbed for a brief time period in order to perform construction activities. However, the ultimate
beneficial gain clearly outweighs any minor short-term disturbances. If during the remedial action it
becomes necessary to discharge impounded water to the on-site streams, all discharges will comply with
the substantive reguirements of the CWA.

All alternatives have short-term risk associated with the respective proposed actions, such as
increased exposure to workers performing the remedial action or increased contaminant runoff into the
subsite streams. However, it is anticipated that all short-term risks associated with the alternatives
can be reduced through construction controls in order to prevent harm.

9.7 Cost

This criterion addresses the direct and indirect capital cost of the selected remedy in addition
to annual O&M costs. It must be noted that all historic costs reflected in the proposed plan and FS
Addendum are estimates in 1994 dollars. The FS was completed in 1993 but the costs are considered 1994
dollars since the information was utilized in the 1994 FS Addendum and proposed plan. An annual
engineering cost index of 3.5% was utilized to approximate 1997 dollars for the selected alternative. It
should also be noted that the proposed plan, FS, and FS Addendum discuss costs in terms of present worth
value (1994) and total estimated costs. For purposes of clarity, this document will only discuss
historic (1994) and current (1997) costs in terms of total estimated costs.

With regard to the selected remedy (Alternative 3b), the current cost is estimated at
approximately 7.1 million dollars (see Table 4). Annual O&M is estimated to cost $140,000 per year
(original 1994 dollar estimate). O&M costs have not been converted to 1997 dollars due to past guestions
regarding the determination of these costs. Historic O&M estimates may be biased high and are thus not
increased in this document. A potential residential component of the 1997 cost is estimated at $721,744.
Maintenance of the ICs will be provided by a financial fund component of the remedy as proposed by the
PRPs in the FS. However, as with any type of ICs, the financial fund concept must be adopted and
supported by local officials and citizens. As previously referenced, the financial fund is provided as
Attachment #5.

With regard to a comparison of costs between the selected remedy and Alternatives 3, 5a, and
Modified 5a; Alternative 3 is estimated to cost $9,270,189 with an annual O&M cost of $140,000 for the
first five years. O&M costs for subseguent years are expected to be approximately $37,000 per year for
monitoring of the remedy. Alternative 5a is estimated to cost $19,559,387 while the O&M component is
estimated at approximately $140,000 annually for five years. Modified Alternative 5a is estimated to
cost $13,361,000 with annual O&M costs of approximately $100,000 for the first five years. Please note
that this paragraph presents the costs as originally stated in the FS, FS addendum, and technical
documents (1994 dollars). As previously referenced, Table 2 provides a summary of Alternatives 3, 3b,
5a, and Modified 5a which includes cost data.

For informational purposes, the high estimate was Alternative 8a which was estimated to cost
$93,156,430 with an annual O&M cost of $1,500,000 for the first eight years. O&M costs for subseguent
years are expected to be approximately $37,000 per year for monitoring of the remedy. As previously
discussed, Tar Creek remediation was estimated at $65,526,433 for Alternative 8a. The lowest estimate
was Alternative 1, estimated at $38,400 to $43,000 annually for monitoring. Again, these costs are in
1994 dollars.

The selected remedy, 3b, is less expensive than all of the 18 original alternatives except for
Alternatives 1 and 2. The principal difference between the selected remedy and Alternatives 1 and 2 is
that Alternatives 1 and 2 do not address ecological risks in any manner. The selected remedy is the
least expensive surface water source addressing remedy (see Table 2) but provides the optimum balance
between cost and protectiveness. The selected remedy provides the greatest amount of engineering actions
at the Baxter Springs subsite when compared to similar Alternatives 3, 5a, and Modified 5a (Table 2).
More expensive and comprehensive remedies are not expected to provide a significant increase in
protectiveness thus their increased cost is unwarranted. The selected remedy is also consistent with
past EPA actions in Regions VI and VII and is acceptable to the state of Kansas. In short, it provides
the best balance of cost and protectiveness. As previously mentioned, Attachment #3 contains more
information on the various alternatives.

9.8 State Acceptance

This criteria addresses the supporting Agency's (KDHE) preferences or concerns about the remedial
action alternatives. The EPA is the lead Agency and has coordinated all site activities with KDHE
throughout the project. The KDHE expressed reservations regarding alternatives that seek to remediate
Tar Creek because of the presence of major downstream sources of metal loadings, the certainty of

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recontamination of the creek as it flows through Oklahoma, the unrecoverable designation of Tar Creek by
the state of Oklahoma, consistency with past actions of EPA Region VI and the state of Oklahoma, and the
cost effectiveness of such a cleanup. The KDHE has stated that it concurs with the selected remedy for
these subsites. A copy of the KDHE concurrence letter is attached.

9. 9 Community Acceptance

This criteria reflects EPA's perception of the community's preferences or concerns about the
selected alternative. Community acceptance of the selected remedy was evaluated during the public comment
period and at a public meeting held on August 25, 1994, in Baxter Springs, Kansas. The community is
supportive of the selected remedy. The results of the community acceptance evaluation are presented in
the attached Responsiveness Summary. Additionally, the community has remained informed due to the large
amount of EPA work that has been completed, and is currently ongoing, at other subsites of the Cherokee
County site and the adjacent Tar Creek, Oklahoma site.

10.0 Description of the Selected Remedy

The EPA is selecting Alternative 3b, presented in the FS Addendum, as the selected remedy. The
selected remedy addresses the current and future human health risks at both subsites (Baxter Springs and
Treece) and ecological risks at the Baxter Springs subsite. Ecological risks at the Treece subsite are
not addressed by this remedy due to technical impracticability which is consistent with past EPA Region
VI actions at the adjacent Tar Creek Superfund Site in Oklahoma and Region VII Operable Unit #05 actions
at the Cherokee County site. Attachment #4 contains additional information regarding the TI waiver.
Section 12 of this document discusses modifications of the original 3b remedy.

The largest capital expense associated with the selected remedy consists of remediating source
areas that contribute metals loading to the Baxter Springs subsite streams which drain to the Spring
River. The selected remedy, which includes engineered actions for source materials (mine wastes),
groundwater, and surface water, is described on Table 3 and is discussed below.

EPA has determined that it is technically impracticable to achieve the AWQC promulgated for the
state of Kansas for all surface streams at these subsites. As part of the ERA and FS, TRVs were
calculated for the streams located in the subsites. TRVs, in general, are site specific water guality
values and were established as remedial goals in lieu of AWQC. The selected alternative is expected to
achieve the TRVs in the Baxter Springs subsite streams, however, TRVs are not expected to be achieved in
the Treece subsite.

The selected remedy does not include ecological remedial actions in the Tar Creek drainage basin
in the Treece subsite. Tar Creek within Kansas is an ephemeral stream and approximately 65.5 million
dollars (Alternative 8a total estimated Treece costs) would be reguired to reduce metals loading in the
Kansas portion of the creek (Treece subsite). The total cost of Alternative 8a is estimated at
approximately 93.2 million dollars. As previously discussed, the selected remedy is estimated to cost
7.1 million dollars (1997 estimate). None of the alternatives evaluated, other than complete removal of
all mine wastes impacting Tar Creek (Alternative 8a), can assure that TRVs would be met and they would
only be met in the relatively short section of Tar Creek within Kansas. Tar Creek would become
recontaminated as it enters and flows through northern Oklahoma. Metals loading sources for Tar Creek in
the Treece subsite (Kansas portion) are insignificant when compared to metals loading in the Region VI
Tar Creek site (Oklahoma portion). EPA Region VI has completed a five-year review of the remedial action
taken at the Tar Creek Superfund site in Oklahoma. That review was released in April 1994 and concluded
the water guality of Tar Creek is affected by irreversible man-made conditions and cannot be economically
remedied and that no further action should be taken to improve the surface water guality. Tar Creek is
classified as a no beneficial use water body in Oklahoma. Additionally, Tar Creek empties into the Neosho
River in Oklahoma and this stream meets water guality criteria or TRVs. Finally, the state of Kansas has
expressed reservations regarding alternatives that seek to remediate Tar Creek, for all of the reasons
listed above. Based on these facts, and in light of the nine criteria which EPA is mandated to consider
in making remedy selection decisions, EPA has determined that actions to attempt to improve surface water
guality in Tar Creek should not be taken as part of this remedial action. However, this action does not
preclude EPA from taking action in the future. The Treece subsite and adjacent Tar Creek site will
continue to be assessed over time by EPA. The three following subsections describe the components of the
selected remedy.

10.1 Surface Water

Figure 2 illustrates the surface water components of the selected remedy and Figure 3 depicts the
watersheds for both subsites. This remedy maximizes reduction of metal loadings to the Spring River from
sources within the Baxter Springs subsite. Outwash tailings deposits, and mine waste piles identified as

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potentially significant (specific deposits, tailings impoundments, or piles identified in the FS as those
that contribute guantifiable amounts of metals to streams) sources in the Baxter Springs subsite, will be
addressed under this alternative. Also, appropriate source containment and drainage/erosion control
measures will be implemented to prevent the release and deposition of additional mine wastes. These
actions will protect species of concern and restore habitat. Surface water actions will not be
implemented in the Tar Creek drainage system in the Treece subsite due to technical impracticability and
conformance with past EPA Region VI actions at the Tar Creek Superfund Site in Oklahoma and Region VII
actions at the Cherokee County Galena subsite (see Attachment #4).

In addition to controlling the discharges from the Bruger shafts, as discussed later in the
groundwater section, the following specific surface water actions will be implemented under the selected
remedy (refer to Figure 2 for the following sections):

1). Source Containment/Stabilization - Baxter Springs
Containment actions will be implemented to address surface water RAOs for Spring Branch and Willow Creek
as follows:

Tailing impoundments BT-2 (Section 2) and the Ballard ponds, BT-4, BT-6, BT-7, BT-8, and
BT-9 in the Spring Branch drainage and BT-1 (Section 3) in the Willow Creek drainage will be
drained, filled, regraded, recontoured, capped with soil/clay cover systems, and
revegetated to prevent deposition of tailings in Spring Branch and Willow Creek during storm
events. Approximately 28 acres of tailings, which are surface water loading sources, will be
remediated under this action.

Chat and excavated chat piles BC-12, BX-11, BX-29, and BX-31 in the Spring Branch drainage
will be regraded, recontoured, and revegetated to reduce surface erosion. This action will
affect approximately 83 acres of chat and excavated chat areas. Chat from BC-12 may be used
as fill and capping material as appropriate.

2). Source Containment/Stabilization - Treece.
No action.

3). Surface Source Removal - Surface Excavation with On-site Disposal - Baxter Springs

Outwash tailing deposits BOW-2 in Spring Branch and BOW-1 in Willow Creek will be excavated and
removed. Materials excavated from BOW-2 will be placed in tailings impoundments BT-6, 8, and 9 and BOW-1
materials will be placed in tailings impoundment BT-1 (Section 3); these impoundments are designated to
be filled and capped. An estimated 82,000 cubic yards (aerial extent of approximately 47 acres) of
outwash tailings will be excavated and removed from the drainages.

4). Surface Source Removal - Treece.
No Action.

5). Drainage/Erosion Controls - Baxter Springs.

Erosion controls will be implemented to reduce surface water transport of contaminants as follows:

Mill waste and tailings erosion will be reduced through channelization of the existing
streams and construction of embankments, dikes, rip-rapped channels, etc. in the reach of
Spring Branch between BT-6 and BT-2 (Section 2) with particular emphasis on the reach
through tailings pile BT-2 (Section 2); and in the reach of the south branch of Willow
Creek between BX-16 and BX-17. Channel improvements and erosion controls will be
implemented on approximately 2,500 linear feet of stream channel. Temporary sedimentation
basins will be constructed at appropriate locations to reduce metal loadings during and
immediately following site remediation. Two temporary basins will be constructed in Spring
Branch and one in the south tributary of Willow Creek.

6). Drainage/Erosion Controls - Treece
No Action.

7). Collection and Treatment - Conventional Metals Precipitation.
Impounded water displaced during remediation of tailing impoundments will be used for construction water
and dust control to the maximum extent practical. Physical/chemical treatment will be performed as
needed on any excess water prior to use or discharge. All such treatment will comply with ARARs for
waste disposal. This applies only to the Baxter Springs subsite since surface water engineering controls
are not planned at the Treece subsite.

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10.2 Groundwater

The groundwater components of the selected remedy are designed to address all the groundwater
risks and RAOs for both subsites through engineering controls supplemented by appropriate ICs. The
following actions will be implemented under the selected remedy:

1). Groundwater Collection/Controls - Hydraulic Controls.

Control Mine-Water Discharges to Surface Water - Groundwater RAO No. 1 will be addressed by
reducing or eliminating the intermittent mine water discharges into Willow Creek by controlling
recharge to the mine workings in the vicinity of the Bruger shafts. This only applies to the
Baxter Springs subsite as previously discussed. Surface water control and diversion
technologies would be utilized to limit recharge to the Bruger workings, thereby controlling the
periodic discharges. Other feasible technologies may be applicable to control the Bruger
discharges including in-mine biological treatment for metals removal, or collection and
temporary storage of mine discharges.

• If, during the remedial design phase, prevention of surface water recharge to the
Bruger complex proves infeasible, Groundwater RAO No. 1 will be addressed through
collection and storage and/or treatment of the Bruger discharges rather than through
prevention of surface water recharge. One of the following collection, storage,
and/or treatment methods will be implemented at the Bruger shafts, if prevention of
recharge is infeasible (again, this is only applicable for the Baxter Springs
subsite):

• Collection and Storage - Surface impoundments or standpipes will be constructed
around the shafts to temporarily store periodic discharges. These structures will be
designed as evaporation ponds or pipes that siphon or facilitate flow back into the
workings when the water levels decrease.

• Biological Treatment - A long-term passive in-mine water treatment system may be
engineered at the Bruger shafts to address the problem of metal laden mine water
discharging to surface water. This type of treatment would involve the placement of
an anaerobic rock filter containing an organic microbial food source in the mine
workings to create conditions favorable for the growth of sulfate reducing bacteria.
Metals would then be removed by sulfide precipitation and would be retained in an
insoluble form in the filter material.

Control of Surface Recharge to the Shallow Aguifer - Groundwater RAO No. 2, preventing further
degradation of conditions in the Tar Creek Superfund site as a result of actions implemented in
the Baxter Springs and Treece subsites, will be addressed by not diverting surface flows into
mine workings in hydraulic connection with the Tar Creek site during remediation efforts. The
selected remedy also meets the groundwater RAO of being consistent or supplemental to past
actions conducted by EPA Region VI and the state of Oklahoma at the Tar Creek site and EPA
Region VII at the Cherokee County site.

Plugging of Abandoned Deep Wells and Grout Injection - Protection of the deep Roubidoux aguifer
from possible downward transport of contaminants in shallow groundwater (Groundwater RAO No. 4)
will be addressed by searching for and plugging abandoned or poorly constructed wells and/or
boreholes connecting the deep and shallow aguifers located during the search. Plugging
activities will be conducted in both the Baxter Springs and Treece subsites.

2). Institutional Controls - Groundwater Use Restrictions - Shallow Aguifer. Groundwater RAO No. 3,
preventing human health risks due to domestic consumption of shallow groundwater, will be addressed
through implementation of institutional water management strategies at both subsites. These
restrictions can be implemented by reguiring the Division of Water Resources to form a Intensive
Groundwater Use Area (IGWUA) which will actually prohibit the future drilling of shallow water wells
for domestic use within both subsites through legal and/or administrative restrictions on the
installation of new domestic shallow wells. The local municipal and county governments will be
encouraged to use the IGWUA to place restrictions on shallow groundwater usage. These restrictions
will have the effect of reguiring future residents to connect to existing Rural Water District
supplies, thereby preventing human consumption of shallow aguifer and/or impacted mine water. The
effectiveness of ICs are dependent upon the actions of local officials and citizens as well as
support by KDHE.

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3). Institutional Controls - Groundwater Management Programs - Deep Aguifer. Groundwater RAO No. 4,
preventing ARARs exceedances in the deep aguifer as a result of downward migration of contaminants
through leaking wells, may also be addressed through the IGWUA water management strategies. This
program may be designed to monitor construction and implement strict design and construction
standards for new deep wells within the Cherokee County Superfund site aimed at ensuring casing
integrity and prevention of potential leakage between the shallow and deep aguifers. Such actions
may be instituted through KDHE under the Groundwater Exploration and Protection Act and will reguire
local support.

10.3 Source Materials

The source material components of the selected remedy were developed to prevent possible human
exposures that could result in excessive risks or elevated blood lead levels. Risks to current residents
will be addressed by source removal or containment while future exposures will be addressed by land use
restrictions to meet applicable RAOs. The following actions will be implemented under the selected
remedy:

1). Existing Development: While the selected remedy is predominantly an ecological action which
addresses surface water, mining wastes, groundwater, and ecological receptors; current human
exposure to surface mine waste will be evaluated and reduced through engineering controls if
necessary. Initially, a search will be performed to identify all residences built on or within
approximately 500 feet of mine wastes in both the Baxter Springs and Treece subsites. Additionally,
a representative sampling of homes within the Treece community will be conducted due to their close
proximity to mine waste piles and tailings impoundments (i.e. not specifically within a definite 500
foot boundary). The community of Baxter Springs will not reguire this degree of characterization
but must also be evaluated in areas of the outlying city which are adjacent to the mining waste
areas (western portion of town). This will consist of using maps and aerial photographs to identify
houses located on or near mine wastes then subseguently verifying the locations in the field. After
identification of potentially affected properties, soil samples will be collected or analyzed by
field screening methods. If soil samples exceed a residential remedial action level (risk management
derived), of 800 ppm lead or 75 ppm cadmium, the yards from which the samples were obtained will be
remediated.

Remediation of yards will consist of actions that include the following: capping the affected yard
with clean soil; excavation of contaminated soil and replacement with clean soil; or relocation.
The soil used for capping and backfilling must meet the criteria of not exceeding 240 ppm lead and
25 ppm cadmium. This criteria is the state of Missouri any-use soil levels and is acceptable to the
EPA and the state of Kansas. The type of remedial action employed will depend on the level of
contamination present in the yard soil, the physical layout of the yard and surrounding features
such as sidewalks and roads, and the design of the individual homes with respect to location and
elevation of windows and porches. Yards that are excavated or capped will be regraded and
revegetated as near as possible to the original condition. Where excavation of yard soils at
existing homes is reguired, the excavated material will be placed in tailings impoundments scheduled
for capping as part of this proposed remedy. The maximum reguired depth of excavation, or amount of
capping soil emplaced, will be one foot. Relocation may be determined as the optimum approach in
certain instances.

2). Future Development: ICs will be established to control future residential development on or within
approximately 500 feet of mine wastes, including areas containing mine waste fill materials.
Residential development may occur on mine waste areas provided the future building site is
remediated by placing one foot of clean topsoil over the area to be developed and by contouring the
property to reduce erosion. A repository may be established and maintained as part of the
Environmental Health Program, described below, for the disposal of soil from future development in
mine waste areas.

If future development occurs on a mine waste area which has been capped as part of the selected
alternative, the cap and grade must be maintained so as not to destroy the protective purposes of
the cap. The cap is intended to protect aguatic life from erosion and runoff, and to also protect
future residents from exposure to mine wastes containing hazardous substances in excess of action
levels. Sampling of building sites will be reguired prior to development to ensure that homes or
buildings are not constructed on soil exceeding action levels.

Remediation of future residential development sites shall be the responsibility of the property
owner or other responsible party. The county will be encouraged to provide oversight and
enforcement of these restrictions on future development through implementation of an Environmental
Health Program. Appendix C in the FS report and subseguent text discuss ICs.

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3). Action Levels: EPA has established action levels based on health criteria for metal contaminants in
residential yards at 800 parts per million (ppm) lead, 75 ppm cadmium, and 23,000 ppm zinc. These
action levels apply to both existing and future residences and are in conformance with a July 1996
Record of Decision for Operable Unit #07 of the Galena subsite. The use of these action levels for
this operable unit constitutes a risk management decision by EPA to utilize the same clean-up
criteria for all residential areas of the Cherokee County Superfund megasite which is divided into
several subsites and operable units. Attachment #2 contains an IEUBK model run for Operable Unit
#07 of the Galena subsite and an Adult Lead model run for the Baxter Springs/Treece subsites. The
PRP IEUBK model run for the Baxter Springs/Treece subsites is contained within the Administrative
Record.

4). Institutional Controls: The ICs will consist of an ordinance that the county will be encouraged to
enact and enforce for the entire Cherokee County Superfund site in order to oversee and control
future residential development in areas of surface mine wastes. The proposed ordinance will create
an Environmental Health Program which will include specific reguirements governing development in
mine waste areas. Development within certain designated areas will be controlled through the filing
of an application for an environmental occupancy permit. An authorized county representative will
issue the permit upon a determination that the risks associated with exposure to mine wastes or
contaminated groundwater have been reduced to acceptable levels. The goal is to enact and enforce
ICs that are applicable for the entire county and thus include all response actions performed at
various operable units or sub-areas of the county wide site. As previously stated, ICs are subject
to local approval and enforcement.

In addition, all areas subject to the Environmental Health Program will be identified on a map which
will be available, filed, and recorded at the Cherokee County Recorder of Deeds Office at the county
seat in Columbus, Kansas. This map will be recorded as soon as possible after implementation of the
program. All mine waste areas located in the Cherokee County Superfund site will be affected by
these institutional controls.

ICs will include a financial fund or similar arrangement to augment the Environmental Health
Program. The funding mechanism will provide an incentive to the county to maintain the program into
perpetuity and will fund the administration and enforcement of the program. The details of the
financial fund are provided in the FS and Attachment #5. The financial fund is subject to local
approval and enforcement as well as support by KDHE.

5). Monitoring Program: A monitoring program will be established to assess new construction of
residences in these subsites, enforcement of the ICs, and any distributions from the financial fund.

Operation and Maintenance

An operation and maintenance (O&M) program will be established to maintain the capped areas and
stream diversion structures at the Baxter Springs subsite and to monitor the streams and enforce ICs at
both the Baxter Springs and Treece subsites. Stream monitoring will include metals analysis and periodic
biological/ecological assessment. The level of reguired maintenance will likely decrease as the capped
and vegetated areas become more established. Embankments, ditches, and dikes will reguire some degree of
O&M efforts as a result of erosional processes. A monitoring program for both subsites will be
established to assess the effectiveness of the remedial action implemented to protect the streams in the
Baxter Springs subsite and to monitor Tar Creek in the Treece subsite. Reports detailing groundwater and
surface water analytical results, biological/ecological assessment, the efforts conducted for maintaining
the capped areas and stream diversion structures, and the maintenance of ICs will be submitted to EPA and
KDHE on an annual basis. The O&M monitoring may also include the collection and analysis of biological
samples. One annual report will detail all of the various O&M efforts for both subsites.

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 applicable guidance and Section 121(c) of CERCLA, 42
U.S.C. °9621(c), as amended.

The five-year review of the selected remedy will be conducted by EPA to ensure that the remedy is
effective and accomplishes the goals of the remedial action. The five-year review will include an
assessment of the groundwater and surface water monitoring information, the results of any biological or
ecological sampling, and the enforcement and maintenance of ICS. The ICS prohibiting use of shallow
groundwater for drinking water purposes and the enforcement of the controls on residential building will
be assessed in addition to ICS that are protective of the capped and graded mine waste areas. During the
five-year review, EPA Region VII will coordinate and consult with EPA Region VI and the states of
Oklahoma and Kansas on the status of the Tar Creek Superfund site and the current water guality

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classifications of the affected streams, including Tar Creek and the Neosho River. Additional EPA
actions at one or both subsites may result from the 5-year review process.

Cost

A detailed cost analysis of this remedy is provided in the FS Addendum (1994 dollars). The
selected remedy is estimated to cost approximately 7.1 million dollars (1997 cost) with an annual O&M
cost of $140,000. The cost estimate for the selected remedy is presented on Table 4.

11.0 Statutory Determinations

Under its legal authority, EPA's primary responsibility at Superfund sites is to undertake
remedial actions that achieve adeguate protection of human health and the environment. In addition,
Section 121 of CERCLA establishes several other statutory reguirements and preferences. These specify
that when complete, the selected remedial action for the 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 technologies or resource recovery technologies to the maximum extent
practicable. Finally, the statute includes a preference for remedies that employ treatment that
permanently and significantly reduces the volume, toxicity, or mobility of hazardous wastes as their
principal element. The following sections discuss how the selected remedy meets these statutory
reguirements.

Protection of Human Health and the Environment

The selected remedy will protect human health and the environment by achieving the RAOs through a
combination of engineering measures and ICs. Existing human health risks due to potential exposure from
soils and mine wastes will be reduced by remediating residential yards situated on or near mine wastes
where action levels are exceeded. Future risks to human health will be reduced by implementation of ICs
that prohibit residential construction on soils or mine wastes with contaminant levels in excess of
action levels and will additionally prohibit use of the shallow aguifer for domestic consumption. Also,
the likelihood of future contamination of the deep aguifer, which is the source of the public drinking
water supply for residents at the site, will be reduced by plugging abandoned deep wells and boreholes
which connect the deep and shallow aguifers.

The selected remedy protects the environment by implementing measures designed to reduce metal
loadings to Spring Branch and Willow Creek of the Baxter Springs subsite and by plugging abandoned deep
wells in both the Baxter Springs and Treece subsites. Mine water discharges from the Bruger shafts
(located in the Baxter Springs subsite) to surface waters will be controlled, tailings impoundments and
chat piles that contribute significant amounts of metals to the streams will be contained/stabilized,
outwash tailings that contribute significant metal guantities will be excavated and removed, and surface
water contamination due to mill waste and tailings erosion will be reduced through channelization of the
existing streams and construction of embankments, dikes, and rip-rap lined erosion controls.
Implementation of these measures is expected to reduce metal loadings to Spring Branch and Willow Creek
(Baxter Springs subsite) to levels below TRVs, which are the environmentally protective RAOs for surface
water cleanup at the site. The reduction of metals in various media will provide protection to species
of concern and restore habitat.

The selected remedy does not include actions designed to improve surface water guality in the Tar
Creek drainage basin in the Treece subsite due to technical impracticability. Downstream sources of
contamination in Tar Creek contribute significant metals loadings which are predominantly responsible for
exceedances of AWQC. None of the alternatives evaluated, other than complete removal of all mine wastes
impacting Tar Creek, can assure that the TRVs would be met, and they would only be met in Kansas. The
estimated cost of complete Tar Creek remediation is approximately 65.5 million dollars (1994).
Furthermore, Tar Creek would become recontaminated as it enters and flows through northern Oklahoma (Tar
Creek Superfund site). The EPA regional office in Dallas, Texas, (EPA Region VI) responsible for
Superfund sites in the state of Oklahoma, released an April 1994 five-year review report of the remedial
action taken at the Region VI Tar Creek Superfund site in Oklahoma, downstream from the Treece subsite.
This report supported the past actions taken at the site and concluded that the water guality of Tar
Creek is permanently impacted by irreversible man-made conditions and cannot be economically remediated
in a technically practicable manner. Tar Creek is classified as a no beneficial use water body. Region
VI determined that no further action should be taken to improve the surface water guality in the Oklahoma
portion of Tar Creek. In short, because of downstream conditions beyond the boundaries of the Cherokee
County, Kansas site, and the substantially greater metals loading in the Oklahoma portion of Tar Creek as
compared to the Kansas portion of the drainage, there is no manner that remedial action in Kansas (Treece
subsite) can cost-effectively achieve a significant reduction of environmental risks in the Tar Creek

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drainage basin, and efforts to do so are considered technically impracticable.

In addition, the state of Kansas has expressed reservations regarding alternatives that seek to
remediate the limited portion of Tar Creek that flows through the Treece subsite, for all of the reasons
listed above. EPA has determined that actions to attempt to improve surface water guality in Tar Creek
should not be taken as part of this remedial action because of the downstream sources of metals
contamination that would not be affected by any remedial action at the Treece subsite, the severely
degraded downstream condition of Tar Creek, the major impacts to the creek being from the Oklahoma
portion of the drainage, decisions by EPA Region VI and the state of Oklahoma, and the state of Kansas'
reservations about remediating this portion of Tar Creek. Additionally, the Neosho River receives Tar
Creek in Oklahoma and continues to meet TRVs or water guality criteria. However, if new information
regarding the Tar Creek site in Oklahoma is discovered or if any information indicates that the selected
remedy is not protective of human health and the environment, EPA may re-evaluate the selected remedy.
Such re-evaluation for the Treece subsite may be likely in the event that Kansas or Oklahoma upgrade the
classification of Tar Creek under the Clean Water Act. All actions under this ROD will be evaluated at a
minimum of every five years in accordance with the statutory reguirement under CERCLA for five-year
reviews.

The selected remedy will address the human health threats posed by conditions at both the Treece
and Baxter Springs subsites. The selected remedy provides the best alternative remedial action for
overall protection of human health and the environment. 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.

Attainment of Applicable or Relevant and Appropriate Requirements of Environmental Laws (ARARS)

Whether the selected remedy will comply with applicable or relevant and appropriate chemical-,
action-, and location-specific ARARs, is discussed below. Compliance with ARARs is reguired of the
selected remedy unless a waiver of an ARAR is justified. This remedy includes waivers based on technical
impracticability.

Chemical-Specific ARARs

The chemical-specific ARARs are identified and discussed in this section. Numerous heavy metals
have been detected in the groundwater and surface water at both subsites. The elements of most concern
are lead, cadmium, and zinc. Certain chemical-specific ARARs will be waived based on technical
impracticability.

1. The Safe Drinking Water Act (SDWA) , 42 U.S.C. ° 300(g) , National Primary Drinking Water Standards,
MCLs, 40 C.F.R. Part 141, and the Kansas Administrative Regulations 28-15-13 for Safe Drinking Water are
relevant and appropriate for this remedial action. MCLs are standards promulgated for the protection of
public drinking water supplies serving 25 or more people. The EPA believes these levels are relevant and
appropriate cleanup goals for contaminated groundwater where that water is currently or potentially a
drinking water source. The groundwater should be cleaned up in accordance with these reguirements
because the shallow groundwater at the subsites is a potential drinking water source and the deep
groundwater is a current drinking water source. The levels established by the Kansas regulations are
similarly relevant and appropriate. The following list identifies the MCLs established by the SDWA and
the state of Kansas drinking water standards for lead and cadmium: Pb-Action level = 15 ppb (at tap);
Cd-MCL = 5 ppb. The selected remedy will not achieve the above listed MCLs in the shallow aguifer
beneath the subsites. Thus, these ARARs are waived based on the technical impracticability of achieving
MCLs in the shallow aguifer (as discussed previously in Section 9.2, herein, and see also Attachment #4).
The technical impracticability (TI) waiver of chemical-specific ARARs criteria under the Safe Drinking
Water Act is based on numerous factors including (1) the size of the Cherokee County Superfund site (115
sguare miles), (2) the huge volume of source materials (4.3 million tons of mining wastes within the
Baxter Springs and Treece subsites), (3) the karst-like conduit flow characteristics and enormous size
and amount of underground mine voids, and (4) consistency with prior EPA decisions regarding the
Tri-State Mining District, of which Baxter Springs and Treece are only a part. For example, the Region
VII 1989 ROD for the Galena subsite groundwater/surface water remedial action (operable unit #05) also
used a technical impracticability waiver of the SDWA criteria for the same shallow aguifer as in the
Baxter Springs and Treece subsites. The TI waiver decision also is consistent with EPA Region VI actions
at the adjacent Tar Creek Superfund site in Oklahoma. None of the remedial alternatives reviewed in the
Feasibility Study and addendum could attain MCLs in the shallow aguifer at the Tri-State Mining District.
The deep aguifer, however, currently meets MCLs at both subsites and will be protected by the
institutional, hydraulic, and engineering controls that are an element of the selected remedy.

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2. EPA Superfund guidance dated January 15, 1993, entitled "Cleanup Level for Lead in Groundwater"
recommends that a final cleanup level of 15 ppb lead in groundwater used for drinking purposes is
protective. The guidance recommends the 15 ppb level as consistent with the action level for lead in
drinking water established under the SDWA. This recommended final cleanup level is to be considered at
the subsites. As with the MCLs, the selected remedy will not achieve the recommended action level for
lead in the shallow aguifer beneath the subsites. The deep aguifer, however, currently meets the
recommended cleanup level for lead and will be further protected by the institutional, hydraulic, and
engineering controls that are an element of the selected remedy.

3. Secondary MCLs and MCLGs are to be considered in implementing this remedy. Secondary MCLs and MCLGs
are standards for public drinking water supplies that only provide for the protection of taste, odor, and
aesthetic gualities. Since these are not health-based criteria, they are to be considered as necessary
to remediate the groundwater at the subsites. Secondary MCLs and MCLGs were published in 50 Federal
Register 46936.

4. The Clean Water Act, 33 U.S.C. 1251 et seg., reguires that states establish surface water guality
standards protective of human health and the environment. Tar Creek and Willow Creek are classified
streams under the Kansas standards (K.A.R. 28-16-28b et seg.). Both are designated for noncontact
recreation and expected aguatic life use, and Willow Creek is designated additionally for food
procurement use. As modified by the National Toxics Rule and subseguent federal regulations (60 FR
22228, May 4, 1995), the standards apply the following relevant criteria to Tar and Willow creeks:
dissolved cadmium, 3 ppb; dissolved lead, 11 ppb; total recoverable zinc, 412 ppb. Although the
beneficial uses of the Spring Branch are not specifically delineated in the standards, the noncontact
recreational and expected aguatic life uses (and, therefore, the criteria cited above for Tar and Willow
creeks) are deemed applicable to the Spring Branch. The Kansas standards reguire that corrective actions
be implemented to restore the designated uses of impaired surface waters and to provide for the return of
the original surface water guality conditions (K.A.R. 28-16-28f(g)). Variances may be granted by the
department based on regional socioeconomic hardship considerations, subject to the review and approval of
Region VII, EPA.

EPA has determined that it is technically impractical to meet these chemical-specific ARARs at the
Baxter Springs and Treece subsites, thus these ARARs are waived. The TI waiver of these standards is
based on the huge volume of mine wastes at the subsites and other factors described previously in Section
9.2 herein. The TI waivers for the chemical-specific ARARs for the selected remedy are fully supported
by this ROD, the associated Administrative Record including the RI and FS reports, and prior EPA/State
decisions regarding the Tri-State Mining area.

Location-Specific ARARs

The location-specific ARARs that will be attained by this remedial action are based on the
location of the subsites and the affect of hazardous substances on the environment at the subsites. The
following describes the location specific ARARs.

1. Executive Order 11988, Protection of Flood Plains (40 CFR 6, Appendix A) is a legally applicable
reguirement for this remedy. Portions of the subsites fall within the Spring River floodplain and
therefore, the area is included within the scope of this executive order, which applies to government
actions. It reguires that such actions avoid adverse effects, minimize potential harm to floodplains,
and restore and preserve the natural and beneficial values of floodplains to the extent possible. The
selected remedy is expected to attain this reguirement.

2. The Endangered Species Act, 16 U.S.C. Section 1531; 50 CFR Part 200; 30 CFR Part 402; and the Kansas
Non-game and Endangered Species Conservation Act, KSA 32-501, are legally applicable reguirements for
these subsites. Several species of endangered or threatened species are found within the subsites and
the reguirements of these acts and regulations are applicable for the protection and conservation of
these species. The U.S. Department of Interior and the Kansas Fish and Game Commission will be consulted
in implementing this remedy for the conservation of the endangered and/or threatened species and habitat
found within the subsites.

3. Executive order 11990, Protection of Wetlands, 40 CFR 6, Appendix A, is a legally applicable
reguirement for this remedy. This order reguires the avoidance to the extent possible of adverse impacts
associated with the destruction or loss of wetlands and to avoid construction in wetlands where
practicable alternatives exist. Because some wetlands may be located within the subsites, this executive
order is applicable, however, the selected remedy is not anticipated to interfere with or impact
wetlands.

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4. The Fish and Wildlife Coordination Act, 16 U.S.C. °661, 40 CFR °6.302 is a legally applicable
requirement for this remedy. This requirement protects fish and wildlife from activities that miqht
affect fish and wildlife habitat, such as diversion or rechannelinq of a stream. The remedy includes
channelization of streams in the Baxter Springs subsite and will be implemented in accordance with the
substantive requirements of the Fish and Wildlife Coordination Act.

5. The National Historic Preservation Act, 16 U.S.C. °°470, et seq. and the regulation at 33 CFR Part
800 require that actions take into account possible effects on historic properties included on or
eligible for the National Register of Historic Places. Since mining activities occurred over 100 years
ago, this requirement is to be considered in the implementation of this remedy in order to preserve
possible historic property which may be encountered at the subsites. Although unlikely, certain mining
property may remain in such condition that historic preservation may be desirable. When practicable,
consideration will be given to proper historic preservation if such mining property is found during
implementation of this remedy.

6. The National Archeological and Historic Preservation Act, 16 U.S.C. °469, and 36 CFR Part 65 require
recovery and preservation of artifacts which may be discovered during government actions. This
requirement is to be considered in the implementation of this remedy in order to preserve artifacts
which may be found at the subsites. The remedial action includes removal and placement of surface mine
wastes at the Baxter Springs subsite. This activity may reveal significant scientific, prehistorical,
historical, or archeological data (prehistorical Native American burial grounds and villages or
historical mining camps could be discovered, although not likely). Therefore when practical,
consideration will be given to preservation if such artifacts are found during implementation of this
remedy.

Action-Specific ARARs

The action-specific ARARs listed below will be achieved by the selected remedy. These ARARs are
based on activities and technologies to be implemented at the subsites.

1. The National Pollutant Discharge Elimination System, Effluent Limitations, 40 CFR Parts 122, 125, and
440 are relevant and appropriate limitations for this remedial action. The regulation at 40 CFR Part 440
sets technology based effluent limitations for mine drainage from mining related point sources. The
remedial action includes the removal and processing of mine waste rock and chat (mining/milling wastes)
at the Baxter Springs subsite. Such activities are sufficiently similar to mining and processing of lead
and zinc ore that the effluent limitations are relevant and appropriate in the event that mine drainage
is generated during the implementation of this remedy. The substantive requirements of these regulations
are expected to be met during the implementation of the selected remedy.

2. The Surface Mining Control and Reclamation Act, 30 U.S.C. °°1201, et. seq., 30 CFR Part 816, Sections
816.56, 816.97, 816.106, 816.111, 816.116, 816.133, and 816.150 are relevant and appropriate for this
remedial action. These requirements provide guidelines for the post mining rehabilitation and
reclamation of surface mines. The activities that will be performed as part of this remedial action are
similar to mining reclamation and these requirements are expected to be met by this action.

3. Kansas regulations, KAR 28-30-1, for construction, reconstruction, and plugging of water wells are
legally applicable for this remedy. The selected remedy includes an investigation and, if necessary,
reconstruction or plugging of deep water wells on the Baxter Springs and Treece subsites in order to
prevent migration of contaminated shallow groundwater to the deep aquifer. The selected remedy is
expected to meet this requirement.

4. Section 404 of the Clean Water Act, 33 U.S.C. °°1251 et seq., 40 CFR Part 230, and 231 prohibit
discharge of dredged or fill material into wetlands without a permit. The selected remedy calls for the
filling of tailings impoundments and subsidences with surface mine wastes. Some flooded subsidences
may be considered "artificial wetlands" sufficiently similar to wetlands and the substantive requirements
of Section 404 are, therefore, relevant and appropriate for this remedy.

5. Section 10 of the Rivers and Harbors Act, 33 U.S.C. °403, and related Regulations 33 CFR °°320, et
seq., and Section 404 of the Clean Water Act, Regulations 40 CFR Part 125, subpart M are relevant and
appropriate requirements for this remedy. These requirements prohibit the disposal of dredged and fill
material into streams without a permit. The selected remedy includes stream channelization at the Baxter
Springs subsite and the substantive requirements of Section 404 are expected to be met.

6. Deed restrictions are institutional controls that the state of Kansas and local governments will
enforce to protect the integrity of the completed remedial actions. Restrictions to be considered in the
implementation of this selected remedy include restrictions on future mining activities, water well

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construction, excavation of backfilled tailings impoundments and subsidences, and other construction in
the areas affected by this remedy. The state of Kansas may consider establishing a Groundwater
Management District program for the Baxter Springs and Treece subsites to limit the use of shallow
groundwater for drinking water purposes, pursuant to Kansas Administrative Regulations 28-30 and K.S.A.
82a-1036.

7. The CWA regulates storm water discharges from industrial activities such as inactive mining sites.
These regulations are applicable because surface mine wastes contribute metals loading to surface water
bodies as a result of runoff generated by infiltration events as well as from erosion of the mine waste
piles by subsite streams. The selected remedy component for the Baxter Springs subsite will meet the
reguirements of these regulations by reducing water pollution from runoff. The storm water discharge
regulations are not applicable to the selected remedy for the Treece subsite because actions taken under
this alternative have no impact on storm water discharge to Tar Creek.

Cost-Effectiveness

The selected remedy is cost-effective because it will provide overall effectiveness proportional
to its costs while also being consistent with past EPA and State actions. The selected remedy will
achieve all the remedial action objectives other than the RAO for Tar Creek surface water, and thus
effectively reduce unacceptable risks to human health and the environment, at an estimated cost of 7.1
million dollars (1997 dollars) . The selected remedy is the least expensive remedy that is protective of
human health and the environment and complies with ARARs. Although Alternatives 1 and 2 are less costly
than the selected remedy, neither of them include any actions to reduce ecological risk and they
therefore do not meet the threshold criteria that remedies must be protective of human health and the
environment. All of the remaining alternatives cost significantly more than the selected remedy, with
only marginal increases in the degree of protectiveness. The most costly remedy (8a) was estimated at
93.2 million dollars (1994 total estimated costs).

Utilization of Permanent Solutions and Alternative Treatment Technology (or Resource Recovery
Technologies) to the Maximum Extent Practicable

The selected remedy represents the maximum extent to which permanent solutions and treatment
technologies can be utilized in a cost effective manner for this remedial action. Excavation and removal
of outwash deposits will permanently eliminate those deposits as a source of metal loadings to the
streams. Draining, filling, and capping tailings impoundments is a permanent action.

Regrading, contouring, and vegetating selected mine waste piles in addition to the
rechannelization and stabilization of streams are also permanent actions. The remediation of impacted
residential yards will permanently eliminate risk to children who live in such residences. Plugging the
abandoned deep wells and boreholes will permanently reduce the likelihood of the deep aguifer becoming
contaminated.

The selected remedy does not utilize alternative treatment technologies since basic engineering
and construction technigues were deemed very effective and desirable. Resource recovery technologies
were not deemed appropriate for this site.

Preference for Treatment as a Principal Element

The selected remedy effectively reduces risks through a combination of engineering and
institutional controls, and thus does not satisfy the statutory preference for treatment as a principal
element.

The principal ecological threats are from heavy metal loadings to surface waters. The volume of
outwash tailings, mining wastes, and milling wastes which contribute metals to surface waters via erosion
is extremely large (4.3 million cubic yards over 28 sguare miles) and treatment of this tremendous volume
of wastes would be impracticable. These wastes can be reliably contained over a long period of time, and
thus engineering controls are being used instead of treatment to reduce ecological risks.

The principal current human health threat posed by the subsites is exposure to contaminated soils
in residential yards. There is no treatment technology that can reliably and cost effectively remediate
large volumes of contaminated soils in place, and thus engineering controls such as capping or
excavation/removal must be utilized to reduce these threats. Relocation may also be an effective
alternative in some instances. The principal future human health threat is from potential consumption of
contaminated groundwater from a shallow aguifer well. The entire Cherokee County site is extraordinarily
large (115 sguare miles), and implementation of an aguifer restoration remedy that treats contaminated
groundwater would be impracticable. In addition, the shallow aguifer is currently not utilized as a
source of drinking water in Baxter Springs and Treece.

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12.0 Documentation of Significant Changes

Changes in this ROD include the modification of the residential action levels for lead and
cadmium. It should be noted that the action level modifications only apply to potential residential yard
excavations. The bulk of the work proposed under this ROD entails ecological work related to surface
water, mine wastes, groundwater and ecological receptors. The specific mine waste piles, tailings
impoundments, outwash tailings areas, and stream modification areas were determined during the
characterization phase based on metals loading to surface and groundwater, thus; the FS Addendum action
levels were tailored to the ecological work rather than primarily for potential residential or human
health aspects of the remedy. The proposed plan indicated that the soil cleanup level for lead would be
500 ppm. The selected remedy specifies a residential lead action level of 800 ppm (800 ppm lead trigger
level with excavation to 500 ppm or a maximum of one foot depth), which is protective of human health and
is consistent with ongoing residential cleanup response actions at the Galena subsite of the Cherokee
County site in accordance with the ROD for operable unit # 07. The cadmium criteria are also identical
to the OU-7 ROD, 75 ppm cadmium trigger level with excavation to 25 ppm or a maximum depth of one foot.

The change in residential action levels is protective and is consistent with remedial action
decisions made by EPA for the Tri-State mining area in July and August 1996. These decisions use 800 ppm
lead as the trigger level for cleanup of residential yards, and are based on health studies conducted at
the Galena subsite by the Agency for Toxic Substances and Disease Registry (ATSDR) and by the Missouri
Department of Health (MDOH). These health studies analyzed residential children's blood lead levels. The
1995 ATSDR study conducted in Galena, Kansas (which is about 3 miles from Baxter Springs) found a
significant human health risk from lead contaminated soils in residential areas. The 1994 MDOH study
conducted in the Joplin, Missouri area (also near Baxter Springs) made similar findings. These studies,
and other analytical data on childhood blood lead levels, formed the basis for Region VII's decision that
the action level for residential yard cleanup in the Tri-State mining district should be 800 ppm lead.
Although these studies and analyses were developed and considered after release of the proposed plan for
Baxter Springs and Treece, Region VII has determined that because of the similarities between the Kansas
and Missouri sites, both contiguous sites and the various operable units within these sites will use the
same remedial approaches and cleanup action levels. EPA, Kansas, and Missouri are in agreement on the
need for consistency in the approach to residential yard cleanup and that the 800 ppm lead level is
protective. These actions thus constitute a risk management decision by EPA Region VII. The recent
ATSDR and MDOH studies, in addition to the Galena OU-7 ROD, are included within the Administrative Record
for the selected remedy.

In addition, EPA has determined that the investigation of mining wastes that may impact
residential yards should not be limited to 500 feet from mining waste areas. The proposed plan set a 500
foot limit for investigation of residential areas near mining wastes or residences built on mining
wastes. The selected remedy reguires an evaluation and investigation of the community of Treece and the
western area of Baxter Springs due to the close proximity of mining wastes to these residential areas. A
strict criteria based on 500 feet within and construction on mine wastes will not be used for the
selected remedy. This modification is necessary because residences need not be built "on" mining wastes
or "within 500 feet" of mining wastes in order to be impacted by mining wastes. Such wastes may have
been physically imported for construction, and erosion such as wind and water action may move waste
materials a much greater distance than 500 feet. Heretofore, implementation of the selected remedy for
residential yard cleanup will be based on future design characterization information obtained from these
areas. Areas will be characterized as necessary in order to determine if residential cleanups are
reguired.

The potential remedial actions for impacted residential areas have also been expanded to include
residential relocations as an option in addition to the historic capping and excavation/backfilling
approaches. EPA believes that certain areas may be impacted to a significant degree, and when
considering all site-specific circumstances, may justify residential relocation as a viable approach.

Changes in costs were also reguired since the past estimates were in 1994 dollars. Costs for the
selected alternative have been updated to 1997 dollars.

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                                KEY TO THE FOLLOWING
                          FIGURES, TABLES, AND ATTACHMENTS
    Figures
         Figure 1 - Site Location
         Figure 2 - Alternative #3b Engineering controls
         Figure 3 - Subsite Watersheds

    Tables

        Table 1 - Remedial Action Objectives
        Table 2 - Summary of Four Alternatives
        Table 3 - Alternative #3b Description
        Table 4 - Alternative #3b Cost Estimate

    Attachments

        Attachment 1 - Responsiveness Summary
        Attachment 2 - IEUBK Model Data and Information
        Attachment 3 - Descriptions of Original 18 Alternatives
        Attachment 4 - "Technical Impracticability Waiver
        Attachment 5 - Financial Fund Information

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                                                                                                    TABLE  I

                                                                      SUMMARY TABLE OF REMEDIAL ACTION OBJECTIVES BY MEDIA  TYPE
  REMEDIAL ACTION OBJECTIVES  SURFICIAL
              MATERIALS
        REMEDIAL ACTION OBJECTIVES
               GROUND WATER
Prevent direct human contact with,
ingestion, and/or inhalation of metal
contaminants of concern  from on-site
surficial materials that would potentially
result in an excess cancer risk greater  than
10 -4, a non-carcinogenic hazard  index of
greater than 1 or blood  lead levels causing
excessive health risks.
Prevent the release of surface water  of
ground water containing metal
contaminants of concern that would result
in exceedance of surface-water ARARs
and excessive ecological risks in the
Baxter Springs/Treece subsites.
Prevent the transport of metal
contaminants and sediments  containing
metal contaminants  from on-site
sources that would  result in
exceedances of surface water ARARs
and/or excessive ecological risks in the
subsite streams and the Springs  and
Neosho Rivers.
Prevent the exposure of terrestrial  biota  to
metal contamination in surficial materials
that would potentially result  in excessive
ecological risks associated with
bioconcentration of site contaminants  of
concern.
Prevent potential degradation of conditions
in the Tar Creek Superfund site in
Oklahoma resulting from implementation
of remedial actions within the Baxter
Springs or Treece subsites, and formulate
remedial alternatives for the Baxter
Springs and Treece subsites that would be
consistent with and/or supplemental to
actions taken for the Tar Creek site.
Prevent exposure of aquatic biota  to
metal contaminants in surface water
that would result in excessive
ecological risks.
                                                     Present risks associated with domestic
                                                     usage of ground-water supplies containing
                                                     concentrations of metal exceeding of
                                                     appropriate ARARS for the Boone aqui fer.
                                                     Prevent exceedance of appropriate
                                                     ARARs resulting from the downward
                                                     migration of metal contaminants of
                                                     concern in shallow (Boone)  ground water
                                                     and/or mine water from on site mining-
                                                     related sources to the deep  (Roubidoux)
                                                     aqui fer.

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                                              TABIiE 2
                        Summary of Alternatives 3, 3b, 5a, and Modified 5a
Alt.  Cost
               Action
                          Baxter Spr.   Treece
                                                       Total
#3 9.3 MY




#3b 5.9 MY




#5a 19.6 MY




#5a 13.4 MY
(mod)



Outwash
Pile/imp
Channels
Dike/emb
Eros/div
Outwash
Pile/imp
Channels
Dike/emb
Eros/div
Outwash
Pile/imp
Channels
Dike/emb
Eros/div
Outwash
Pile/imp
Channels
Dike/emb
Eros/div
47 acres
29 acres
1,000 ft.
500 ft.
500 ft.
47 acres
111 acres
2,500 ft.
500 ft.
500 ft.
47 acres
113 acres
1,000 ft.
500 ft.
500 ft.
47 acres
29 acres
1,000 ft.
500 ft.
500 ft.
15 acres
25 acres
800 ft.
3,800 ft.
500 ft.
0 acres
0 acres
0 ft.
0 ft.
0 ft.
15 acres
450 acres
2,300 ft.
3,800 ft.
500 ft.
15 acres
215 acres
800 ft.
3,800 ft.
500 ft.
62 acres
54 acres
1,800 ft.
4,300 ft.
1,000 ft.
47 acres
111 acres
2,500 ft.
500 ft.
500 ft.
62 acres
563 acres
3,300 ft.
4,300 ft.
1,000 ft.
62 acres
244 acres
1,800 ft.
4,300 ft.
1,000 ft.
                      Action Descriptions

   Outwash -  Excavation of outwash tailings followed by placement in tailings impoundments.
   Pile/imp - Redistributing,  regrading, countouring, and vegetating mine waste piles.  Draining,
          filling,  grading,  contouring,  and vegetating mine waste impoundments.
   Channels - Rechannelization of streams.
   Dike/emb - Construction of dikes and embankments.
   Eros/div - Construction of erosion control, slope stabilization, and diversion structures.
          * - Costs are in 1994 dollars

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TABIiE 3
Description of the Selected Remedy
Alternative #3b

Surface Water Actions - Baxter Springs subsite only

Source Containment/Stabilization: Drain, fill, regrade, recontour, cap, and vegetate tailings
impoundments BT-1, BT-4, BT-6, BT-7, BT-8, and BT-9 (28 acres). Redistribute, regrade, recontour, and
vegetate mine waste piles BC-12, BX-11, BX-29, and BX-31 (83 acres). These actions total 111 acres.

Surface Source Removal: Excavate outwash tailings BOW-1 and BOW-2 (47 acres). Place excavated material
in tailings impoundments discussed above.

Drainage/Erosion Control: Rechannelization of 2,500 feet of existing stream channel of Spring Branch
between mine waste piles BT-6 and BT-2. Construction of approximately 1,000 feet of dikes, embankments,
erosion control, and diversion structures.

Collection and Treatment: Collect and treat impounded water displaced during implementation of the
remedial action in the tailings impoundments. Discharge treated water to the ground surface for dust
suppression during the remedial action.

Groundwater Collection/Controls - Hydraulic Controls (Applies to one or both subsites as indicated)

Control of Mine Water Discharges to Surface Streams: Construct surface water diversion structures in the
vicinity of the Bruger shafts in the Baxter Springs subsite to control or contain mine water discharges
from entering surface streams. Actions may include biological treatment and/or temporary storage of mine
discharge water.

Control of Surface Water Recharge to the Shallow Aguifer: Construct surface water diversion structures
during remedial actions at the Baxter Springs subsite in order to prevent surface water infiltration to
mine workings which recharge the shallow aguifer.

Plugging of abandoned deep Wells: Identify and plug any abandoned or poorly constructed wells that
penetrate though the shallow aguifer into the deep aguifer. This action applies to both the Baxter
Springs and Treece subsites.

Residential Source Material Actions - Both subsites

Surface Source Removal: Characterize the residential area of the Treece subsite and the rural
residential area of the Baxter Springs subsite. Residential yards exceeding 800 ppm lead or 75 ppm
cadmium will be excavated or capped. These action levels are risk management values which are used for
all subsites and operable units of the Cherokee County site.

Institutional Controls - Both subsites

Ground Water Use Restrictions: Establish institutional controls through the Cherokee County Commission
to prohibit domestic use of shallow aguifer water and limit use to agricultural purposes.

Ground Water Management: Establish institutional controls through KDHE or the Cherokee County Commission
to regulate and monitor construction of deep aguifer wells within the Cherokee County site.

Future Residential Development: Establish institutional controls through the Cherokee County Commission
to regulate the future construction of residential homes in mine waste areas. Controls will consist of
an ordinance or permits which reguire residential yard soils to be sampled prior to construction in
potentially impacted areas. Contaminated soils would reguire capping or removal prior to development.

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                                                  TABIiE  4
                                   Cost Estimate for the Selected Remedy
                                              Alternative 3b
    Item Description          Baxter Cost
Surface Water Actions
     Outwash Deposits
     Piles/impoundments
     Stream Channelization
     Dikes/Embankments
     Erosion/Diversion
     Basins/Ponds
     Subtotal                 $3,173,039

Groundwater Actions
     Deep Well Abandonment    $  244,925
     Bruger Shaft Actions     $   97,567
    Institutional Controls    $  110,872

     Subtotal                 $  453,364

Residential Actions
     Yard excavation/capping  $  100,000
     Institutional Controls   $  110,872
               Treece Cost
                               Total
$1,020,054
$1,397,170
$ 512,782
$ 15,523
$ 12,052
$ 215,458
$ 0
$ 0
$ 0
$ 0
$ 0
$ 0
$1,020,054
$1,397,170
$ 512,782
$ 15,523
$ 12,052
$ 215,458
     Subtotal
$  210,872
Indirect Costs
     Engineering Design       $  224,236
     Construction Management  $  474,633
     Contingency              $  887,603
     Subtotal

    Total Estimate
$1,586,472

$5,423,747
               $ 0
               $  653,132
               $ 0
               $  110,872

               $  764,004
$  400,000
$  110,872

$  510,872
$   52,492
$  111,109
$  207,783

$  371,384

$1,646,260
                $3,173,039
                $  898,057
                $   97,567
                $  221,744

                $1,217,368
$  500,000
$  221,744

$  721,744
$  276,728
$  585,742
$1,095,386

$1,957,856

$7,070,007
    * The FS and FS Addendum estimates of cost are in 1994 dollars.
    This table utilizes a 3.5% annual increase multiplier to covert
    historic costs to 1997 dollars.
    * Additionally,  the residential component assumes 25 homes total
    at $20,000 per home (5 homes/Baxter and 20 homes/Treece).

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                                   ATTACHMENT I - RESPONSIVENESS SUMMARY

                             RESPONSIVENESS SUMMARY FOR THE RECORD OF DECISION
                                      Baxter Springs/Treece Subsites
                                  Cherokee County, Kansas Superfund Site

This responsiveness summary is divided into the following sections:

Overview:            This  section discusses the public  comment  period,  public  meeting,  and the  public's
                     view  of  EPA's preferred alternative.

Part I:              Part  I provides  a summary  of commentors' major issues  and concerns,  and  expressly
                     acknowledges and responds  to guestions  raised verbally by the  local  community at  the
                     public meeting.   The  "local community" may include local  homeowners,  businesses,
                     municipalities,  and potentially responsible parties (PRPs).

Part II:             Part  II  provides a comprehensive response  to all  written  comments  received and is
                     comprised primarily of the specific legal  and technical guestions  raised during the
                     public comment period.   As necessary,  this section will elaborate  with technical
                     detail on answers covered  in Part  I.

Overview

       The proposed Plan and supporting documents included in the Administrative Record file  were
initially available for public comment from August 19,  1994,  to September 16,  1994, and were  extended for
an additional thirty days of public comment to October 16, 1994.  A public meeting was held on August 25,
1994, at 7:00 p.m. at the Community Center in Baxter Springs, Kansas. Comments received from the local
community, both in writing and during the public meeting, were directed in general toward issues
involving cost of the proposed remedy, rationale for the remedy, and specific guestions regarding the
proposed actions.  The transcript from the public meeting is contained within the Administrative Record
file.  The non-PRP local community did not express any adversity to EPA's recommended approach or
indicate a preference for another approach or remedy.

       NL Industries, Inc.,  a PRP at  the Site,  sent a letter to EPA during the public comment period
stating their position that Alternative 2  in the Feasibility Study was the only remedy that would both
address the risk posed by the Site and comply with the National Contingency Plan (NCP).

       Gold Fields American Corporation, a PRP at the Site,  sent a letter to EPA during the public
comment period which stated their objections to the Proposed Plan and reguested that the Administrative
Record for the Baxter Springs and Treece subsites be changed in response to their comments.

      A letter was submitted to EPA by Environmental Management Services Company (EMS)  on behalf of the
following PRPs:  ASARCO, Inc.; Gold Fields Mining Corporation;  NL Industries,  Inc.; The Doe Run Company
(St. Joe Minerals Corporation); Cyprus Amax Minerals Company, Inc.; and Sun Company, Inc., which stated
both their general and specific comments concerning Proposed Plan  statements they felt were
guestienable.

Part I:  Summary of Commentors' Major Issues and Concerns

       This section provides  a summary of  commentors'  major issues and concerns raised during the public
meeting followed by a response.

Question:  A citizen asked for a comparison of heavy metals reduction in surface water between the 5.9
million dollar remedy and the 80.0 million dollar approach.

Response:  The reduction of heavy metals in surface water at the Baxter Springs subsite is expected to be
approximately 60 to 70 percent for the 5.9 million dollars remedy  (1994 costs) .  The difference in the
reduction of heavy metals between the 5.9 million dollar remedy and the greater reduction associated with
an 80.0 million alternative is not thought to be warranted when considering the cost differential and the
expected protectiveness of the 5.9 million dollar remedy.  It should also be noted that the 5.9 million
dollar remedy has now increased  (1997 dollars)  in cost to approximately 7.1 million dollars due to
inflation and residential assumptions.  Additionally, the 80 million dollar amount for the most
protective remedy was the 1994 present worth cost, the total estimated cost was approximately 93.2
million  dollars.  The surface mine wastes that are not proposed for  cleanup in the approximate 7.1
million dollar remedy (1997 estimate) are located in the Treece subsite and areas of the Baxter Springs
subsite that are positioned away from the streams and are therefore not predominantly contributing metal

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loads to the Baxter Springs subsite streams. The selected remedy will address only those mine wastes
directly contributing metal loads to the Baxter Springs subsite streams that are identified in the
Feasibility Study Report and Addendum as the significant waste piles or areas contributing metals
loading. The selected remedy does not address non-residential wastes in the Treece subsite due
to technical impracticability, in other words, the high cost and nature of the problem do not warrant
action at this time.

The primary difference between the approximate 7.1 and 93.2 million dollar (1994 total cost) alternative
is that, although both alternatives address significant contributions of metals to the Baxter Springs
subsite streams, the 93.2 million dollar alternative would remediate all surface mine wastes in both the
Baxter Springs and Treece subsites. However, the cost of this approach is not warranted when
consideration is given to the fact that the streams draining the Treece subsite would immediately become
re-contaminated as they cross the Kansas state line and enter Oklahoma. Past actions by EPA Region VI
and the state of Oklahoma have determined that actions to remediate Tar Creek within Oklahoma are
considered impracticable, thus it would be inconsistent to take a differing approach in the Kansas
portion of the historic mining area, especially considering that the majority of the flow and impacts
occur within Oklahoma.

Question: A citizen asked EPA to explain how it is determined that a particular mine waste area or pile
contributes metals loadings to streams.

Response: During the past investigation, mine wastes and surface water samples were collected at various
locations to determine metals loading. Streams were sampled at the head of the stream and at various
points between downstream piles and waste deposits or areas. The concentration of metals and the flow
velocity of the streams were measured along the various points and a valuation was then made of how many
pounds of metals were passing each point in that particular part of the stream. Comparison of the data
from various points along the stream indicated the locations where concentrations of metals increased,
thus it was possible to determine the mine waste source areas or piles which contribute the major metals
loadings to the streams.

Question: A citizen inguired about the Proposed Plan's intention to plug abandoned deep wells and wanted
to know if the proposed alternative included filling all holes such as test boreholes. In addition, how
will it be determined if wells or boreholes go through the shallow aguifer into the deep aguifer?

Response: The wells that will be plugged are wells that penetrate or go through the shallow aguifer
(located near the ground surface to approximately 400 feet deep) down into the deep aguifer which is
about 1,000 feet below the surface. The selected remedy does not reguire plugging all of the existing
wells; if a well terminates in the shallow aguifer, it will not be plugged. Standard test boreholes are
routinely plugged as part of standard field activities and should thus not pose a problem. The EPA and
the state of Kansas acknowledge that the shallow aguifer is contaminated and cannot be practically
remediated. However, plugging the deep wells will protect the deep groundwater by not allowing the
contaminated shallow aguifer water to migrate to the deep aguifer. Historic boring records will be used
to determine which wells penetrate the shallow
aguifer.

Question: A citizen asked why the Treece subsite is still considered a part of the overall Cherokee
County Superfund site if no clean-up will be performed at that subsite.

Response: Although engineering construction activities related to the mine waste areas are not planned
for the Treece subsite, other types of work will be performed in Treece. Institutional controls
consisting of health education, blood lead monitoring and controlling future residential development in
mine waste areas will be implemented in Treece in addition to testing and remediating residential yards
impacted by mining wastes. Additional work may be conducted at the Treece subsite in the future if new
remedial response actions are recommended by the state of Oklahoma or Kansas as well as EPA Regions VI
and VII. New or previously unknown information or changing site conditions may facilitate new future
actions. Thus, Treece remains an active part of the Cherokee County Superfund site and is included
in all remedy aspects with the exception of engineering controls for mine waste source areas.

Comment: A citizen asked why no action is proposed for the Treece subsite; is Treece not important
enough to cleanup?

Response: Action will be taken in Treece to protect human health in the form of institutional controls
implementation and residential yard testing followed by subseguent remediation if deemed necessary.
These are the same actions as for Baxter Springs. When determining the appropriate remedy to address
contamination at a Superfund site, EPA is reguired by law to evaluate potential remedies using certain
specific criteria. As a result of the evaluation of these criteria, the selected remedy includes
identical actions to protect human health in both the Baxter Springs and Treece subsites, which is the

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same decision for protection of human health in the other subsites of the larger Cherokee County site.
The difference in the selected remedy between Treece and Baxter Springs is that Tar Creek in Treece will
not be subject to surface water cleanup in order to address ecological risks. This decision does not
impact protection of human health in Treece.

EPA believes the benefit of remediating Tar Creek in the Treece subsite would be minimal because of the
downstream contamination of Tar Creek (most of the contamination enters the creek as it flows through
Oklahoma) and its classification by the state of Oklahoma as a stream that is irreparably damaged by
manmade influences. At this time, EPA Region VI and Oklahoma have not proposed any engineering actions
to remediate Tar Creek and have determined that it would be impractical to do so. The stream is
classified as a no beneficial use water body. EPA and the state of Kansas have also determined that it
would be technically impracticable at this time to conduct engineering actions for Tar Creek. However,
if EPA Region VI or the state of Oklahoma decide to modify the existing Tar Creek remedy in the future,
EPA Region VII and the state of Kansas may also reconsider the remedial action decision for the Treece
subsite and, as necessary, may propose a remedial action for the Treece subsite to address the ecological
risk posed by the surface water contamination. EPA intends to be flexible and consistent in dealing with
the entire Tar Creek watershed and feels that the current approach achieves those goals.

Question: A citizen asked if it was correct that EPA was not going to remove the tailings from the
Treece subsite and also asked if EPA was not planning on remediating the gravel roads. The citizen
expressed concern about children riding school buses on gravel roads.

Response: As discussed in the previous responses, the selected remedy does not include remediation of
mine tailings in the Treece subsite. In addition, the selected remedy does not address the gravel roads
in either subsite. Air monitoring in several locations along roadways within the subsites found no
problems with the dust from an inhalation standpoint. No lead or any other metals were detected above
national standards in the air monitoring program; thus, the gravel roads do not likely pose a significant
inhalation health risk. EPA acknowledges that there may potentially be dermal risks to children under
six years of age who come into contact with certain dusts from mining wastes used in road application.

Question: A citizen guestioned the manner in which EPA would be able to successfully plug wells where
casing was installed in the well.

Response: It is a common procedure to plug wells and EPA has successfully performed this type of work at
other subsites of the Cherokee County site. The remedial design documents will specify the actual
methods by which the deep wells will be plugged. Wells are typically grouted or over-drilled and grouted
as part of the plugging procedure.

Question: A citizen asked when tests of Willow Creek were conducted and whether they were performed
during wet weather. The citizen also asked if water flowing off the gravel roads was tested.

Response: During the remedial investigation, samples were collected from Willow Creek on a guarterly
basis for one year; taken in February, May, August, and November/December of 1993. Runoff samples from
gravel roads were not collected.

Question: A citizen asked the following guestions concerning the surface mine waste piles: 1) are some
piles in the Baxter Springs area contaminated while others are clean; 2) will each pile be dealt with
individually; 3) what is considered the definition of a pile, how high?

Response: To the extent that the surface mine waste piles will be addressed by the selected remedy, each
individual surface mine waste pile or area (tailings impoundments, outwash deposits, etc.) will be dealt
with individually because each area varies substantially. Some piles or areas have low concentrations of
metals, do not impact ecological receptors, and do not reguire cleanup. Other piles have higher levels
of contaminants, impact receptors, and thus reguire cleanup. The specific piles and other mine waste
areas (tailings impoundments and outwash deposits) reguiring cleanup are identified in the Record of
Decision (ROD) and the Feasibility Study Addendum. The term "pile" is generic. Surface mine waste
piles include piles as tall as 200 feet and range downward to relatively planar areas that are
approximately six inches high and spread over a large area.

Question: A citizen asked what amount of material will be removed and where will it be taken.

Response: The excavated mine wastes will be placed into existing tailing impoundments at the Baxter
Springs subsite for consolidation, grading, capping, and revegetation. Nothing will be hauled off the
Cherokee County site and deposited at other locations. All wastes will either be capped in place or
excavated and moved to another portion of the site followed by capping and revegetation. The intent is
to reposition the wastes to reduce or eliminate the metals loading characteristics of the current piles
or areas. The selected alternative will address 158 acres of mining wastes and 3,600 feet of channel

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improvements.

Question: A citizen asked if mine shafts will be filled in Baxter Springs and Treece as they were in
Galena, Kansas.

Response: There are no plans to fill the mine shafts as was done in Galena. The Galena area did not
contain several large scale tailings impoundments for mine waste placement so the large number of mine
shafts were thus considered appropriate repositories for the mine wastes. There are fewer shafts and
collapse features in the Baxter Springs and Treece areas and a much larger number of tailings
impoundments; thus, the selected remedy includes plans to place the wastes in tailings impoundments in
the Baxter Springs subsite and then cap the impoundments.

Comment: A citizen expressed concern about water running out of the mine shafts and into surface water
streams and creeks. This citizen felt that the shafts needed to be filled to prevent this from
happening.

Response: This is a valid concern that has been addressed by the selected alternative. The selected
remedy will control mine water discharges from certain mine shafts which were identified for cleanup
during the remedial investigation (RI) and feasibility study (FS). As part of the remedial design phase,
EPA will also evaluate possible diversions around mine shafts to prevent rain water and surface water
runoff from going into the shafts as well as containing any shaft discharges from flowing into surface
water bodies.

Question: A citizen asked what was the possibility of the estimated 5.9 million dollar remedy increasing
in cost and what was EPA's genuine guess on the cost.

Response: The selected remedy was expected to cost 5.9 million dollars in 1994 and has already increased
in cost to approximately 7.1 million dollars as previously discussed. The increase is a result of
inflation estimated at 3.5% per year in addition to the inclusion of residential cost assumptions. The
original cost estimate was in 1994 dollars and has been updated to reflect 1997 dollars. The original
estimate was calculated by Dames and Moore, the engineering firm that conducted the RI/FS. Unforseen
circumstances could potentially increase the existing cost estimate, but there is no current information
indicating that this is likely.

Part II: Response to Written Comments

This section provides responses to written comments or guestions regarding the proposed plan for the
Baxter Springs/Treece subsites of the Cherokee County site.

Comment: EPA received one comment from Gold Fields American Corporation (Gold Fields), in a letter dated
10/14/94 from Terrence Gileo Faye, Esg. , to EPA. In that letter, Gold Fields stated that it disagrees
with and reguests a modification of the statement in the proposed plan, page 4, that the responsible
parties "chose not to undertake" the response actions in the Galena subsite of the Cherokee County site.

Response: EPA believes the proposed plan language is accurate. Gold Fields refused to perform the
actions reguired by the unilateral administrative order (UAO) issued on June 10, 1990, EPA Docket No.
90-F-0017. Gold Fields did not comply with this UAO although it offered partial performance. The
partial performance activities offered by Gold Fields were inconsistent with the planned response actions
and not authorized by EPA. Gold Field's justification for failing to comply with the UAO was without
sufficient cause because Gold Fields's offer was only for partial performance. Therefore, pursuant to
Section 122(e) (6) of CERCLA, 42 U.S.C. ° 9622(e) (6), EPA reguested on August 14, 1990, that Gold Fields
cease its unauthorized activities. EPA believes that Gold Fields did have an opportunity to undertake
full performance of the response actions and, in fact, declined this opportunity.

Comment: EPA received a letter dated October 4, 1994 from Environmental Management Services Company
(EMS) on behalf of ASARCO, Inc., Gold Fields, N.L. Industries, Inc., The Doe Run Company (St. Joe
Minerals Corporation), Cyprus Amax Minerals Company, Inc., and Sun Company, Inc. The following comments
were made in the October 4, 1994 letter. EPA responses to the comments are also provided.

Comment: The commenters state that they believe Alternatives 3, 3b, and Modified 5a have similar
prescribed actions and the same planned operation and maintenance provisions, and that these alternatives
would have nearly egual long-term permanence.

Response: With regard to prescribed actions and long-term permanence, the referenced alternatives are
nearly egual only for the Baxter Springs subsite. They are not egual for the Treece subsite since
modified alternative 5a proposes engineering actions in the Tar Creek drainage while alternatives 3 and

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3b do not. Modified alternative 5a is thus considered to have greater long-term permanence than
alternatives 3 and 3b since it includes a greater amount of permanent engineering controls. With regard
to operation and maintenance (O&M) provisions, the referenced alternatives are also only approximately
egual for the Baxter Springs subsite. Since modified alternative 5a includes greater engineering
controls, a greater amount of O&M would also be reguired.

Comment: The commentors stated that the Ecological Risk Assessment (ERA) determined that there were no
exceedances of federal Ambient Water Quality Criteria (AWQC) in the Spring River attributed to the
transport of metals from the Baxter Springs subsite.

Response: Irrespective of the status of AWQC exceedances in the Spring River, the streams in the subsite
watersheds have designated uses independent of those for the Spring River. Under present site
conditions, those uses are not being achieved. In this respect, the remedial action objectives are
reasonable for the site. In addition, AWQC are designed to protect 95% of the species 95% of the time,
not all species, including protected or sensitive species. Since there are nine State protected species
known to occur or to have habitat within the site, the planned response actions are further justified.
The commentor implies no exceedances in this subsite. However, Willow Creek has contaminant loading
problems that do cause significant metal loads to enter Spring River as evidenced by documented
exceedances of AWQC in Spring River. Additionally, the RI/FS estimated that 24,000 pounds of zinc are
annually loaded to the Spring River from streams draining the Baxter Springs subsite.

Question: The commentor states that aguatic sampling of Spring Branch did not document any ecological
affects attributed to metals in the Spring Branch drainage.

Response: While the field data possibly indicate no acute effects, they are inadeguate to determine
chronic, sub-lethal effects, which are of greater significance to viability of the on-site populations
than the acute effects. In addition, as it stated in Section 8 of the ERA, there are a number of factors
that may be masking the toxicity of the metals of concern. These include, but may not be limited to,
acclimation of the aguatic species inhabiting on-site ponds and streams, speciation/bioavailability of
the metals of concern, and freguency and pattern of occurrence of toxic conditions. While field data for
a single fish species may indicate that this single species is seemingly tolerant of adverse conditions,
the calculated toxicity guotients (TQs) indicate that non-acclimatized organisms would be adversely
affected. Since this condition limits the introduction and establishment of organisms in the affected
habitats, ecological structure and function is restricted (i.e., fewer and fewer types or organisms and
less resilience in the trophic relationships). Achieving the remedial action objectives and Toxicity
Reference Values (TRVs) in the on-site streams will alleviate this situation, even though AWQC may not be
achieved in all instances.

Additionally, there were a number of assumptions incorporated into the ERA that would result in a
non-conservative (i.e., underestimated) characterization of risk. These all further justify taking
actions to reduce ecological risks at the Baxter Springs subsite. For aguatic receptors they include:

TQs were calcuated using LOAELS vs. NOAELS (typically a 10X less stringent value).

• Mean chronic LOAELS were calculated from a range of values rather than taking the most
conservative LOAEL value.

• TQs were divided into categories, with values greater than one, but less than five, assumed
to reflect individual but not population level effects. For all intents and purposes,
concentrations reflecting the potential for adverse effects on indiviauals were disregarded.
The justification for this approach is based on the factors likely influencing the toxicity
of metals at the site. These include varying bioavailability due to metal speciation,
acclimation, and the ability of aguatic receptors to tolerate infreguent pulses of elevated
metals concentrations, as evidenced by site-specific fish data.

• Exposure to sediment was omitted as an exposure pathway. It was assumed that surface water
concentrations represented eguilibrium conditions with the associated sediments. This may
have underestimated exposures to bottom-dwelling or bottom-feeding organisms.

• Dissolved metals concentrations were adjusted using ratios based on stream-specific sampling
data (dissolved concentration/total recoverable concentration) rather than assuming 100%
availability of total recoverable metals.

For terrestrial receptors they include:

• TQs were calculated using LOAELS vs. NOAELS (typically a 10X less stringent value).

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• Mean chronic LOAELs were calculated from a range of values rather than taking the most
conservative LOAEL value.

• TQs were divided into categories, with values greater than one, but less than five, assumed
to reflect individual but not population level effects.

• For vertebrates, the most likely exposure (MLE) intake estimates were used rather than the
reasonable maximum exposure (RME) intake estimates.

Question: The commentor does not believe the proposed remedial action will meet TRVs for Spring Branch
with the exception of the lower 2,400 feet, and that a waiver of TRVs will be reguired.

Response: The TRVs or Preliminary Remediation Goals (PRGs) are not legally enforceable reguirements and
thus do not reguire a waiver. The remedial action objectives (RAOs) achieve risk reduction and
protection of the environment and may not be waived. Therefore, a "waiver" of TRVs or PRGs is
inappropriate. Although EPA believes the remedy will meet TRVs, the selected remedy waives AWQC for acute
and chronic protection of aguatic life, because it is not technically practical to achieve the applicable
Kansas water guality reguirements. EPA believes the RAOs will be met, but AWQC may not be met in the
upper reaches of Spring Branch. Note that this response and associated guestion only pertain to the
Baxter Springs subsite.

Question: The commentor reguested that EPA reconsider sampling homes within 500 feet of mine waste
piles, since the RI tended to show that elevated metals were not present farther than 300 feet from the
piles. The commentor believes that the selected remedy may reguire remediation of residential yards
contaminated from lead based paint or other non-mining sources.

Response: EPA acknowledges the results of the RI, but chooses to act more conservatively because the
extent of potential residential impacts was not fully characterized during the RI. The amount of
residential sampling was somewhat limited in scope and it is therefore not prudent to indicate that there
are definitely no impacted residential areas and no need for additional sampling beyond a somewhat
arbitrary 300 or 500 feet boundary. This is the reasoning for actually expanding the characterization
effort to include the community of Treece, Kansas as well as rural areas of Baxter Springs, Kansas rather
than utilizing a strict 300 or 500 feet boundary approach. EPA believes that weathering processes (wind
action, infiltration and runoff, mechanical weathering, etc.) are capable of moving and depositing mining
wastes as much greater distance than 300 or 500 feet. EPA does agree that the expected number of
impacted residences are likely to be few, if any, but feels that additional study, performed during the
remedial design (RD) or early remedial action (RA) phases, is necessary in order to be conclusive. With
regard to non-mining impacts, while it is apparent that additional sources of lead certainly play a role,
it has been well documented that the primary lead impact in the former Tri-State Mining District is from
past mining activities.

Question: The commentor guestioned the need for a formal "engineered" repository for disposal of
residential soil from future home construction. The commentor also felt that soil from commercial
development should not be disposed in the repository.

Response: EPA agrees to reconsider the repository issue during the RD phase of the project. If it is
determined, as a component of the RD, that there are a sufficient number of existing mine shafts,
subsidence areas, or areas of surficial mine wastes located within the entire boundaries of the Cherokee
County site, EPA feels that these areas would be more desirable for placement of future excavated
residential soils as opposed to a formal engineered repository providing that some type of control would
be exercised in these areas.

EPA agrees that the repository, if deemed necessary, would be for soils resulting from future residential
development regardless of the size of the development, however, commercial development need not be
subject to such institutional controls unless the development presents a risk to human health similar to
a residential development, for example, day care centers and recreational facilities that attract young
children.

Question: The commentor guestioned what type of "monitoring" will be involved with the operation and
maintenance for the institutional controls established by the county and reguested more detail on the
monitoring program.

Response: Monitoring reguirements are dependent on the type of institutional controls actually
established by the county. Monitoring reguirements will be specified once the county has implemented the
institutional controls. These are expected to be accomplished during the design phase of the project.
EPA anticipates that operation and maintenance monitoring activities would include, at a minimum, the
following activities: blood lead sampling and analysis; community and physician health education; lead

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outreach activities; inspections of engineered structures; and surface water sampling and analysis. It
should also be understood that there is some uncertainty regarding the county's implementation and
enforcement of institutional controls.

EPA received a letter dated October 14, 1994, from Marcus A. Martin representing NL Industries, Inc. The
following summarizes the comments made in the October 14, 1994, letter and the corresponding EPA
responses.

Comment: The commentor made the statements that drainage in the Baxter Springs subsite contributes "only
a minute percentage" of metals load to the Spring River, the Spring River does not exceed Kansas Aguatic
Life Criteria (ACL or federal AWQC), and that the proposed remedy is not cost-effective given the small
percentage of metals load.

Response: EPA feels that the selected remedy is cost-effective as it constitutes a much lower cost than
several alternatives evaluated in the FS. The selected remedy is actually the least expensive remedy
other than the no action alternative and is now estimated at approximately 7.1 million dollars. As a
comparison the most costly alternative was estimated at 93.2 million dollars (1994 total costs).
Cost-effectiveness is a modifying criteria to be applied as part of a comparison of overall effectiveness
and cost, see the NCP, 40 C.F.R. °300.430(f)(l)ii(D), which states that a "remedy shall be cost-effective
if its costs are proportional to its overall effectiveness". EPA believes the proposed remedy is
cost-effective and meets the standards in CERCLA and the NCP.

Information and analytical data from the Kansas Department of Health and Environment (KDHE) indicates
that the Spring River does exceed alternate concentration limits (ACLs) for cadmium, lead, and zinc. The
selected remedy is a single component which addresses one operable unit of the overall Cherokee County
site. EPA's goal for the site as a whole includes remediation of significant sources of metals loading to
the Spring River. The approach at Baxter Springs will assist in the achievement of that goal. EPA also
believes the an annual zinc loading of 24,000 pounds, as estimated in the RI/FS, is not a minute amount
of metals loading in the Spring River.

Comment: The commentor states that metals loading from selected piles do not adversely impact biota in
Spring Branch or Willow Creek and the effects are overestimated. The commentor also states that biota in
Spring Branch are healthy and reproducing normally, and that the TRVs were not accurately calculated.

Response: The calculated TRVs, and exposure point concentrations (EPCs), for Spring Branch and Willow
Creek were based on EPA approved methods. The RI/FS and associated analytical work identified piles or
mine waste areas contributing significant metal loads to streams. EPA believes there is a large body of
evidence that indicates environmental harm is resulting from this site. The zinc loading to Spring River
from Spring Branch and Willow Creek was estimated at 24,000 pounds annually in the RI/FS reports which
were prepared by PRPs. The zinc loading to Tar Creek was estimated at 220,000 pounds per year at the
Treece subsite while the total zinc load, inclusive of the major downstream Oklahoma portion, was
estimated at 2.8 million pounds per year. Tar Creek is classified as a no beneficial use water body in
Oklahoma, technically impracticable to repair or remediate the manmade degradation. Thus, it is clearly
obvious that past mining practices have definitely impacted surface water bodies in the Kansas and
Oklahoma portions of the Tri-State Mining District. Additionally, information from nearby sites in
Missouri indicates a similar situation.

A prior response provides information on several factors that are masking the toxicity of the metals of
concern. The ERA also contained several assumptions which would significantly underestimate the degree
of risk.

Comment: The commentor disagrees with the calculation of TQs for fish and mink, and states that mink
were not collected or sampled from the site to assess the effect on them from metals contamination.

Response: EPA believes that the TQs were properly calculated. TQs are based on the TRVs in comparison to
site specific values. Tables 8-4 and 8-6 of the ERA summarize the TQs for aguatic vertebrates and aguatic
invertebrates, respectively, based on the concentration of each dissolved fraction metal occurring in
each specific drainage within each subsite. Moreover, the percent bioavailability (i.e., dissolved
concentration/total recoverable concentration) of each metal was calculated based on site-specific date.

Site-specific TQs were calculated using median chronic lowest observed adverse effects levels (LOAELs)
adjusted based on uncertainty factors associated with extrapolations between test species and species of
interest, duration of test differences, and variations in measured effects (e.g., no observed adverse
effect level vs. lowest observed adverse effect level, vs. LD 50, etc.). More recent risk assessments
have incorporated adjustments to toxicity reference values based on allometric relationships between the
mean weight of the test organism and that of the organism of interest. EPA has compared the adjusted
LOAELs used in this risk assessment with values calculated using more recent toxicity test data and the

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allometric equations and finds that, while not identical, the LOAELs used are acceptable.

Section 4.3 of the EPA states that, when identifying chemicals of concern (COCs), the risk assessors did
combine data for the upstream sampling locations of Tar Creek and Willow Creek, owing to a lack of
significant difference in the data as measured by a one-tailed t-test. Furthermore, the risk assessors
combined the downstream sampling station data within each drainage, but not between drainages, for
comparison to the upstream sampling stations. As stated above, however, TQs were calculated on a
stream-specific basis and are properly calculated.

With respect to the mink, the comment does not recognize the concept of assessment endpoints in
ecological risk assessments. The mink was chosen to represent those upper trophic level organisms at the
site that would consume both aguatic and terrestrial organisms. The mink represents a functional element
of the ecosystem, not just the mink itself. While the concentration of contaminants in prey organisms
may be influenced by the size of their home range, habitat, or even patterns of behavior, the home range
and feeding area of the predator organism determines the validity of consolidating exposures related to
food sources. In this instance, the typical home range of a mink comprises well over 50% of the area of
the larger of the two subsites, and an even larger percentage of the area of the smaller subsite. In
addition, the ingestion scenario used in the ERA assumed 50% mice and 50% fish in the diet of the mink.
Information in EPA's Wildlife Exposures Handbook indicates that during certain portions of the year
amphibians may make up a significant portion of the diet of the mink. Amphibians may have body burdens
of metals egual to or greater than those evidenced by on-site mice and fish, although these prey
organisms were omitted from the ingestion calculations. Conseguently, the consolidation of data for mice
and fish between subsites is justified and conservative.

Comment: The commentor suggests that the selected remedy would destroy critical habitat for Kansas
threatened and endangered (T&E) species.

Response: EPA has coordinated with the Kansas Department of Wildlife and Parks (KDWP) and determined
that certain species are listed as Kansas T&E species due to the range of the species. In other words,
the area of the Cherokee County site is within the current range of these species although the species
are likely more common in other parts of the state. EPA has every intent to coordinate all remedial
actions with KDWP to ensure habitat is not disturbed if, in fact, a species is present at a particular
part of the site.

Comment: The commentor suggests that EPA has not considered recent changes or reductions in metals
loading to streams at the site resulting from cessation of activities at the Bingham Sand and Gravel
operation located at the head of Willow Branch or the remediation of the Galena subsite.

Response: EPA has assessed the changes cited by the commentor. With respect to Willow Branch, even
though the chat washing operation in Bingham's pond has ceased, the outwash sediments in the branch
reguire removal in order to eliminate the source. EPA acknowledges the achievement of water guality
improvement at the Cherokee County, Galena subsite by the past remediation of wastes. However, as
mentioned above, there are other significant sources of metals loading that reguire remediation in order
to improve water guality in the Spring River Basin. These sources include the Baxter Spring subsite as
well as the Jasper County, Missouri Superfund site.

Comment: The commentor suggests that the risks posed to the Spring River by the Baxter Springs subsite
are no greater than the risks posed to the Neosho River by the Treece subsite, and since EPA is not
proposing remedial action (non-residential) for the Treece subsite, the Baxter Springs subsite should
also not be remediated with respect to non-residential actions. Additionally, the commentor states that
since EPA decided that remediation (non-residential) in Treece would not be cost-effective, and that the
cost-per-pound of zinc reduction in Baxter Springs is higher than for Treece, the Baxter Springs subsite
should likewise not be remediated.

Response: EPA disagrees with the commentor's logic of deciding or recommending not to take action at the
Baxter Springs subsite simply because actions are not recommended at the Treece subsite. Again, the
actions discussed in this comment and response are the engineering controls for mining wastes impacting
surface water bodies and ecological receptors as opposed to the potential residential components of the
remedy. There are important distinctions between Tar Creek which drains the Treece subsite and Spring
Branch/Willow Creek which drain the Baxter Springs subsite. A significant factor in the selection of
differing actions for the two streams are the substantially different downstream surface water guality
and uses of each stream in addition to consistency with past actions implemented by EPA Region VI and the
state of Oklahoma for the Tar Creek drainage basin.

Tar Creek briefly flows through Kansas prior to entering Oklahoma and subsequently travels a much greater
distance in Oklahoma prior to discharging to the Neosho River, also in Oklahoma. The major impacts to
Tar Creek are from mining wastes in Oklahoma since the majority of the stream flow is in Oklahoma and

-------
there are substantial historic mining areas in Oklahoma. The Oklahoma portion of Tar Creek is classified
as an irreparable surface water body which has been degraded by manmade actions.

The State of Oklahoma and EPA Region VI have determined that it is impracticable to attempt to remediate
Tar Creek, thus the relatively small portion of the creek which flows through Kansas would similarly be
technically impracticable to remediate since any environmental gain would be small when considering the
size of the entire drainage basin and the fact that the creek would immediately become re-contaminated as
it entered Oklahoma. Conversely, the end point for Spring Branch and Willow Creek (draining the Baxter
Springs subsite) is the Spring River which is a valuable surface water resource used for recreation and
swimming. This resource will be protected by the selected remedy which very appropriately specifies
differing actions for the different streams draining the two subsites. Moreover, Spring Branch and
Willow Creek have designated uses independent of Spring River. Under present site conditions, those uses
are not being achieved. In this respect, the selected remedy is appropriate for the Baxter Springs
subsite because it will improve water guality in these streams.

The commentor's focus on cost-effectiveness is based on a comparison of the cost-per-pound of zinc
reduction in Tar Creek and fails to fully consider the broad cost-effectiveness of a Tar Creek remedy,
which must be made in the context of the whole stream system. EPA considered the overall cost of
cleanup for all of Tar Creek in Kansas at approximately 65.5 million dollars (an approximate 93.2 million
dollar total remedy) as estimated in 1994 dollars. Comparing this cost with the amount of expected zinc
reduction in Tar Creek at the Neosho River does not appear to be cost-effective, especially considering
that no actions are being implemented in Oklahoma due to the severely degraded and irreparable nature of
the stream. In addition, the cleanup of Tar Creek is not cost-effective in Kansas when considered in
full context that after crossing the Kansas/Oklahoma state line, the stream is immediately
re-contaminated. Conversely, the remediation of the Baxter subsite streams in deemed cost effective
since valuable water resources will be improved; Spring Branch, Willow Creek, and Spring River. The zinc
loading to Spring River from Spring Branch and Willow Creek (draining the Baxter Springs subsite) was
estimated at 24,000 pounds per year in the RI/FS reports. The surface water guality remediation costs
for the selected remedy at the Baxter Springs subsite are estimated at approximately 8.2 million dollars
(1997 estimate). EPA thus considers the approximate 7.1 million dollar remedy (total costs in 1997
dollars) to be extremely cost-effective.

Additionally, EPA must again point out, as at the Proposed Plan stage, that the Agency is not proposing
any remedial action for mining wastes impacting surface water bodies in the Treece subsite at this time.
Should EPA Region VI, EPA's lead office for work in Oklahoma, take additional actions in Tar Creek to
improve water guality or if the states of Kansas or Oklahoma recommend improving the water guality in Tar
Creek, EPA Region VII will reconsider a new proposal for remedial action in the Treece subsite in
accordance with the reguirements of the NCP. This remedy will also be reassessed on a five-year basis and
may reguire modification or additional effort if deemed necessary.

Comment: The commentor speculates that the selected remedy will not achieve the remedial action
objectives for Spring Branch surface water and that EPA should waive chemical-specific ARARs for the
surface waters of the Baxter Springs subsite.

Response: EPA believes that the remedy will meet the remedial action objectives. If it is determined
during subseguent five-year reviews of the selected remedy that the objectives are not being met, EPA may
reassess the remedial action and reguire additional actions be performed to further reduce metals loading
to the streams in order to then meet the remedial action objectives.

EPA agrees that cheimical-specific ARARs for surface water of the Baxter Springs subsite should be waived
under the selected remedy. The ARARs that will not be met by the selected remedy are waived in the
Decision Summary portion of the ROD. EPA also re-emphasizes that remedial action objectives are not
identical to chemical-specific ARARs. The remedial action objectives for surface water cleanup include
the TRVs, which were approved by EPA. However, TRVs are not ARARs.

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ATTACHMENT 2 - IEUBK MODEL DATA AND INFORMATION

Attachment #2 - Baxter Springs/Treece ROD

This attachment contains additional supporting information pertaining to the integrated exposure
uptake biokinetic model (IEUBK) and the adult lead model. As referenced in the Record of Decision for
operable unit #03/04 of the Cherokee County, Kansas site, the residential action levels are risk
management values utilized for the entire Tri-State Mining District sites in EPA Region VII. The
Cherokee County, Kansas and Jasper County, Missouri sites are contiguous to one another and are
predominantly separated based on the Kansas/Missouri state line. The area is sufficiently similar and was
only divided into two separate sites predominantly based on the fact that the area encompasses portions
of two states; thus, EPA has extrapolated or utilized the modeling results for the Missouri portion to
also apply to the contiguous Kansas portion of the historic mining district. In an effort to be
consistent in the close geographic regions of two states, EPA has chosen to use the same residential
action levels for the two Superfund sites. Additionally, these two sites are divided into several
operable units. EPA feels that it would be extremely cumbersome and inconsistent to utilize differing
residential cleanup criteria for all of the operable units which encompass both contiguous sites.

The IEUBK modeling for the Jasper County, Missouri site was performed by the Missouri Department
of Health and is attached. The attachment specifies the model values that were utilized for the various
runs and the predicted blood level results for varying scenarios. This modeling formed the basis for the
selection of cleanup levels for all Tri-State Mining District sites within Region VII.

The adult lead model was run for OU-3/4 for informational purposes only. The non-residential
actions prescribed by the ROD are based on ecological risks while the residential actions are based on
IEUBK modeling and consistency approaches. The adult lead attachment is provided simply for background
or additional information.

-------
Mr. Mark Doolan
Remedial Project Manager
U.S. Environmental Protection Agency
726 Minnesota Ave.
Kansas City, KS 66101

Dear Mr. Doolan,

       Enclosed is a draft Technical Memorandum for the Jasper County Site.  The Memorandum provides a
brief risk analysis of several clean-up options which are being considered for the Jasper County site.

       If you have any comments or questions on the document or we can be of further assistance,  please
feel free to call me at  (314) 751-6111.



CBD:egd

Attachment
cc: Dave Mosby

-------
DRAFT
Technical Memorandum

Risk, Analysis of Clean-Up Options for the
Jasper County Site, Jasper County, MO

The Jasper County Site is a former lead and zinc mining, milling and smelting area in southwest
Missouri. Soils, streams and groundwater at the site are contaminated with heavy metals, primarily
cadmium, lead and zinc. Very high concentrations of lead (>5,000 mg/kg) have been found in residential
yards in some areas of the site, primarily in the vicinity of the former Eagle Picher Smelter.

A lead and cadmium exposure study was conducted by the Missouri Department of Health to determine
if there was a relationship between exposure to lead and cadmium at the site and elevated blood lead and
urine cadmium levels. A study group was randomly chosen from people living in the vicinity of the Jasper
County Site. A similar control group was randomly chosen from an area unaffected by mining, milling and
smelting of lead and zinc. Conclusions of the study indicated blood lead levels were significantly
greater in the study area than in the control area and that environmental exposure to lead in soil was
the most important factor influencing blood lead levels (MDOH 1995).

Blood lead levels are a measure of an individual's level of exposure to lead. Blood lead levels as
low as 10 ug/dL have been associated with subtle adverse health effects such as decreased intelligence,
impaired neurobehavioral development and decreased hearing acuity. The severity of effects increases as
blood lead levels increase. At extremely high blood lead levels (>80 ug/dL), coma, convulsions and death
have occurred (CDC 1991).

The Integrated Exposure Uptake Biokinetic Model (IEUBK) is a computer model created by EPA to
estimate a plausible distribution of blood lead levels resulting from environmental exposure to lead.
The model was developed using environmental and biological data from a lead mining and smelting
Superfund site. The model combines lead concentrations in air, drinking water, diet, soil and household
dust with behavior and biokinetic variables to predict blood lead levels in children aged 0-6 years.
Default values are provided for each variable used in the model. The model allows and encourages use of
site-specific values for most variables.

The IEUBK was used to evaluate several options currently under consideration for the remedial and
removal activities at the Jasper County Site. The proposed options are:

• Removal of soil from all houses with soil lead over 5,000 mg/kg
• Removal of soil from all houses with soil lead over 4,000 mg/kg
• Removal of soil from all houses with soil lead over 3,000 mg/kg
• Removal of soil from all houses with soil lead over 2,500 mg/kg
• Removal of soil from all houses where the block soil lead value averages 2,000 mg/kg
• Removal of soil from all houses with soil lead over 1,000 mg/kg
• Removal of soil from all houses with soil lead over 800 mg/kg

All options were evaluated using the specified lead concentration and site- specific values for
other variables. Each option was evaluated with and without a backyard gardening scenario.
Site-specific lead concentrations in air, drinking water and garden produce were determined during the
Jasper County Remedial Investigation (Dames and Moore 1995). A table summarizing these values is
presented in Appendix I. Paired soil lead and household dust lead samples were collected during the Lead
and Cadmium Exposure study (MDOH 1995). The paired samples were examined to determine if a relationship
existed between soil and dust lead concentrations. The following eguation describes that relationship:

In(dust Pb)=0.56[In(soil Pb)]+2.78
(n=125.r 2=0.36.p<0.01)

This regression was used to predict the lead-in-dust concentration for each soil level proposed.

For each option, the estimated mean blood lead level, the percentage of the population predicted
to exceed 15 ug/dL and the percentage of the population predicted to exceed 10 ug/dL are presented in
Table 1.

-------
                                                  Table 1
                                       Summary of Risk Analysis for
                              Proposed Soil Levels at the Jasper County Site
                   With Backyard Gardens
Without Backyard Gardens
Mean
Predicted Percent
Soil/Dust
Lead
(mg/kg)
5,000/1,900
4,000/1, 677
3,000/1,427
2,500/1,289
2,000/1,137
1,000/772
800/681
Blood
Lead
(ug/dL)
21.0
19.3
17.3
16.1
14.9
11.7
10.9
Predicted
to Exceed
15 ug/dL
72.73
66.92
58.29
52.78
47.56
28.52
23.80
Mean
Percent Predicted
Predicted
to Exceed
10 ug/dL
92.6
90.67
86.23
81.13
78.4
61.13
55.50
Blood
Lead
(ug/dL)
19.3
17.5
15.3
14.0
12.7
9.2
8.3
Percent
Predicted
to Exceed
15 ug/dL
66.92
61.13
50.13
42.68
34.02
13.64
9.36
Percent
Predicted
to Exceed
10 ug/dL
90.67
86.23
78.40
72.73
66.92
40.37
32.10
For the purpose of comparison, EPA's soil lead guidance states that an unacceptable health risk is
presented when more than 5% of a population's blood level is predicted  to exceed 10 ug/dL (EPA 1994).

       None of these options alone meet the criteria set forth in the current soil lead guidance.   There
are additional intervention measures which could be taken to further reduce exposure to lead.  Potential
measures may include providing health education and HEPA vacuum cleaners,  which may substantially reduce
the lead load in household dust. To evaluate this alternative, the IEUBK was run for each of the proposed
options with the dust concentration set at the default of 200 mg/kg.  Results of these model runs are
presented in Table 2.
                                                  Table 2
                             Summary of Risk Analysis for Proposed Soil Levels
                          with Additional Intervention at the Jasper County Site
                  With Backyard Gardens
Without Backyard Gardens


Soil/Dust
Lead
(mg/kg)
5,000/200
4,000/200
3,000/200
2,500/200
2,000/200
1,000/200
800/200
Mean
Predicted
Blood
Lead
(ug/dL)
13.3
12.1
10.8
10.2
9.5
8.0
7.7

Percent
Predicted
to Exceed
15 ug/dL
36.13
30.26
22.39
18.62
15.45
8.79
7.28

Percent
Predicted
to Exceed
10 ug/dL
69.83
64.01
52.78
47.56
42.68
30.26
26.86
Mean
Predicted
Blood
Lead
(ug/dL)
10.9
9.6
8.2
7.5
6.7
5.0
4.7

Percent
Predicted
to Exceed
15 ug/dL
23.80
16.45
9.36
6.42
3.90
0.92
0.61

Percent
Predicted
to Exceed
10 ug/dL
55.50
45.07
32.10
25.29
18.62
6.84
5.00
       In conclusion,  at the lead concentrations currently being considered,  it does not appear that soil
removal alone will be a sufficient remedy.  If one of the proposed levels is selected as the clean-up
level for Jasper County, additional measures to reduce lead exposure, such as providing clean fill for
garden plots, providing HEPA vacuum cleaners and continued blood lead monitoring and health education may
be necessary remedial activities for the Jasper County site.

-------
References
    CDC (Centers for Disease Control and Prevention), 1991.  Preventing Lead Poisoning in
         Young Children. U. S. Department of Health and Human Services. Atlanta GA. 108 pp.

    Dames and Moore. 1995. Remedial Investigation Report for Seven Designated Areas of
         the Jasper County Superfund Site, Jasper County, MO.

    EPA (Environmental Protection Agency). 1994. Revised Interim Soil Lead Guidance for
         CERCLA Sites and RCRA Corrective Action Facilities. Office of Solid Waste
         and Emergency Response. OSWER Directive 9355.4-12.

    Missouri Department of Health. 1995. Final Report. Jasper County, Missouri Superfund
         Site Lead and Cadmium Exposure Study. U.S. Department of Health and Human
         Services, Atlanta, GA.

                                      Prepared by:

         Missouri Department of Health. Bureau of Environmental Epidemiology
          210 El Mercado Plaza, P.O. Box 270, Jefferson City, MO 65102
                                    June 1, 1995

-------
                                                Appendix I
                         Summary,  of Site-specific Input Values  Used for the  IEUBK
                              Jasper County Superfund Site, Jasper County, MO

                                                 Table A-l
                               Summary of Site-specific  Inputs for the IEUBK
    Variable
    Air
     Mean concentration of Pb in air
     Vary air concentration by year
     Indoor air Pb concentration as a percent
       of outdoor air concentration
    Drinking Water
     Mean concentration of Pb in water
    Diet
     Alternate diet values
     Percent of diet which is fruit/leafy
      vegetables
     Percent of diet which is root vegetables
     Percent of diet which is local fish
     Percent of diet which is local beef
    Soil/Dust
     Mean concentration of Pb in soil
     Indoor dust Pb concentration
     Soil/dust weighting factor
     Default
      Value
   0.1
ug/m
No
30%
    4.0 ug/L

       No
       N/A

       N/A
       N/A
       N/A

   200 mg/kg
   200 mg/kg
       45%
Site-specific
    Value

 0.07 ug/m 3
     No
     30%
            3.0 ug/L

             Table 2
               2.5%

               2.5%
               0.6%
              Varies
              Varies
               17.5%
   Value
    Used

0.07 ug/m 3
    No
    30%
                 3.0 ug/L

                  Table 2
                    2.5%

                    2.5%
                    0.6%
                   Varies
                   Varies
                    17.5%
                                                 Table A-2
                             Concentrations of Lead in Various  Diet Components
           Media
             Fruits/leafy vegetables
             Root vegetables
             Fish fillets
             Beef/game meat
Lead Concentration
       0.62
       6.2
       0.08
       0.05
Values determined during the Remedial Investigation for the site (Dames and Moore.  1994)

-------
ADULT LEAD MODEL ASSUMPTIONS
BAXTER SPRINGS AND TREECE SUBSITES
CHEROKEE COUNTY, KANSAS SUPERFUND SITE

95th Percentile Blood Lead inferus (PbB adult 95): The agency guideline for protection of
children using the IEUBK is 10 Ig/dL. The point value of 10 Ig/dL was used in this
assessment.

Mean ratio of fetal to maternal Blood Lead (R.): A point value of 0.9 has been suggested
based on Goyer (1990) and Graziano et al. (1990). This point value was selected in the
California Gulch evaluation and for consistency, was used in this assessment.

Individual geometric standard deviation (GSDi): A range of values from 1.6 (IEUBK) to 2.6
(National Health and Nutrition Examination Surveys, NHANES III) have been suggested for
GSDi. The NHANES survey included exposures to a wide range of lead sources. The population
expected to be exposed to the Federal Tailings dam is relatively homogenous, thus a GSDi of
1.8 was used in this assessment.

Baseline blood lead value (PbB adult 0): The national estimates from NHANES range from 1.7
to 2.2 Ig/dL, depending on the racial and ethnic composition of the target population. A
value of 2.0 Ig/dL was used in this assessment because it represented an approximate central
point of the range of possible values.

Biokinetic slope factor (BKSF, ug/dL per ug/day): Based on the data presented in Pocock et
al. (1985) and Sherlock et al. (1984), a point value of 0.4 has been suggested. That value
was used in this assessment.

Soil ingestion (TRs, g/day): Occupational soil ingestion rates may vary from 0.05 g/day
(office worker) to 0.48 g/day (gardener/landscaper), depending upon the occupation. Persons
working around the site are expected to have more contact with soils than an office worker,
but less than gardeners/landscapers, thus a soil ingestion rate of 0.1 g/day was used in
this assessment.

Soil Exposure freguency (EFs)(days/yr): Agency guidance suggests a default value of 250
days per year. Because persons working on the site are not expected to be exposed to the
dam area on a daily basis, an exposure freguency of 100 days/year was used in this analysis.

Absolute Gastrointestinal Absorption fraction (AF. unitless): A site specific estimate of
0.15 was chosen for use in this analysis.

-------
United States Environmental
Protection Agency
Technical Review
Workgroup for Lead
December 1996

                                          Recommendations of the
                                Technical Review Workgroup for Lead for an
                         Interim Approach to Assessing Risks  Associated with Adult
                                         Exposures to Lead in Soil
                                                  Preface
This report includes a fact sheet Technical Review Workgroup for Lead (TRW) Recommendations
for an Interim Approach to Assessing Risks Associated with Adult Exposures to Lead in Soil along
with an Appendix, Eguations and Rationale for Default Values Assigned to Parameters in the Slope
Factor Approach and Exposure Model for Assessing Risk Associated with Adult Exposures to Lead
in Soil, which discusses in greater detail the eguations and parameters used in the methodology.
                                   U.S. Environmental Protection Agency

                                    Technical Review Workgroup for Lead


                                               CHAIRPERSONS
Patricia Van Leeuwen
Region 5
Chicago, IL
Paul White
Office of Research and Development
Washington, DC
                                                  MEMBERS
Harial Choudhury
Office of Research and Development
Cincinnati, OH

Barbara Davis
Office of Solid Waste and
Emergency Response
Washington, DC

Robert Elias
Office of Research and Development
Research Triangle Park, NC

Susan Griffin
Region 8
Denver, CO
Karen Hogan
Office of Prevention, Pesticides
and Toxic Substances
Washington, DC
Mark Maddaloni
Region 2
New York, NY

Allan Marcus
Office of Research and Development
Research Triangle Park, NC
Chris Weis
Region 8
Denver, CO

Larry Zaragoza
Office of Solid Waste and
Emergency Response
Washington, DC

-------
                                   Adult Lead Risk Assessment Committee
                                                  of the
                                  Technical Review Workgroup for Lead
                                                CHAIRPERSON

                                              Mark Maddaloni
                                                 Region 2
                                               New York, NY
                                                  MEMBERS
Mary Ballew
Region 1
Boston, MA

Cherri Baysinger-Daniel
Missouri Department of Health
Jefferson City, MO

Mark Johnson
Region 5
Chicago, IL

Kevin Koporec
Region 4
Atlanta, GA

Roseanne Lorenzana
Region 10
Seattle, WA
Margaret McDonough
Region 1
Boston, MA

Patricia Van Leeuwen
Region 5
Chicago, EL

Chris Weis
Region 8
Denver, CO

Paul White
Office of Research and Development
Washington, DC

Larry Zaragoza
Office of Solid Waste and
Emergency Response
Washington, DC

-------
1. INTRODUCTION

This report describes a methodology for assessing risks associated with non-residential adult
exposures to lead in soil. The methodology focuses on estimating fetal blood lead concentration in women
exposed to lead contaminated soils. This approach also provides tools that can be used for evaluating
risks of elevated blood lead concentrations among exposed adults. The methodology is the product of
extensive evaluations by the Technical Review Workgroup for Lead (TRW) which began considering
methodologies to evaluate nonresidential adult exposure in 1994 (Balbus-Kornfeld, 1994; U.S. EPA, 1994a).
In 1995, the TRW reviewed a methodology developed by EPA Region 8 for deriving risk-based remediation
goals (RBRGs) for nonresidential soil at the California Gulch NPL site (U.S. EPA, 1995). A TRW committee
on adult lead risk assessment was formed in January, 1996 to further develop the ideas and information
gathered as part of these previous efforts into a generic methodology that could be adapted for use in
site-specific assessments.

This report provides technical recommendations of the TRW for the assessment of adult lead
risks using this methodology. An overriding objective in the development of this methodology was the
immediate need for a scientifically defensible approach for assessing adult lead risks associated with
nonresidential exposure scenarios. The TRW recognized that other adult lead models may provide useful
information. In particular, models providing more detailed representations of lead kinetics may be
useful in supporting more detailed predictions about the time course of blood lead concentrations among
individuals who receive brief acute exposures to lead or whose exposures otherwise change markedly with
time. The methodology presented here uses a simplified representation of lead biokinetics to predict
guasi-steady state blood lead concentrations among adults who have relatively steady patterns of site
exposures (as described in this report). The TRW believes that this approach will prove useful for
assessing most sites where places of employment are (or will be) situated on lead contaminated soils.
This information is expected to promote consistency in assessments of adult lead risks. The methodology
described in this report is an interim approach that is recommended for use pending further development
and evaluation of integrated exposure biokinetic models for adults. The TRW is undertaking review of
other models and will provide reviews on other approaches as appropriate. The Integrated Exposure Uptake
Biokinetic (lEUBK)Model for Lead in Children (U.S. EPA, 1994b,c) is the recommended approach for
assessing residential lead risks.

The recommended approach for assessing nonresidential adult risks utilizes a methodology to relate
soil lead intake to blood lead concentrations in women of child-bearing age. It is conceptually similar
to a slope factor approach for deriving RBRGs that have been proposed by Bowers et al. (1994) and which
was adapted for used at the California Gulch NPL site in Region 8 (U.S. EPA, 1995). This report
describes the basic algorithms that are used in the methodology and provides a set of default parameter
values that can be used in cases where highly guality data are not available to support site-specific
estimates. The rationale for each parameter default value is provided in the Appendix.

2. OVERVIEW OF THE APPROACH

The methodology described in this report relates soil lead concentrations to blood lead
concentrations in the exposed population according to the algorithms described below. Note that the
algorithms may consist of variables that include superscripts and/or subscripts. The convention adopted
in this report is to use superscripts as exponents (i.e., a mathematical operation), whereas subscripts
represent key words that provide additional information to distinguish between similar variables. The
basis for the calculation of the blood lead concentration in women of child-bearing age is the algorithm
given by Eguation 1:

PbB adult, central = PbB adult, 0 + PbSDBKSFDlR SDAF SDEF S (Eguation 1)
AT

where:

PbB adult, central = Central estimate of blood lead concentrations (Ig/dL) in adults (i.e., women of
child-bearing age) that have site exposures to soil lead at concentration, PbS.

PbB adult, 0 = Typical blood lead concentration (Ig/dL) in adults (i.e., women of child-bearing age) in
the absence of exposures to the site that is being assessed.

PbS = Soil lead concentration (Ig/g) (appropriate average concentration for individual).

BKSF = Biokinetic slope factor relating (guasi-steady state) increase in typical adult blood
lead concentration to average daily lead uptake (Ig/dL blood lead increase per Ig/day lead
uptake).

-------
IR S  = Intake rate of soil, including both outdoor soil and indoor soil-derived dust  (g/day).

AF S = Absolute gastrointestinal absorption fraction for ingested lead in soil and lead in dust derived
       from soil (dimensionless).

EF S = Exposure freguency for contact with assessed soils and/or dust derived in part from these soils
       (days of exposure during the averaging period);  may be taken as days per year for continuing long
       term exposure.

AT = Averaging time; the total period during which soil contact may occur; 365 days/year for continuing
       long term exposures.

       The basis for the RBRG calculation is the relationship between the soil lead concentration and the
blood lead concentration in the developing fetus of adult women that have site exposures.  As a
health-based goal,  EPA has sought to limit the risk to young children of having elevated blood lead
concentrations.  Current Office of Solid Waste and Emergency Response (OSWER) guidance calls for the
establishment of cleanup goals to limit childhood risk of  exceeding 10 Ig/dL to 5%  (U.S. EPA,  1994a).
Eguation 2 describes the estimated relationship between the blood lead concentration in adult women and
the corresponding 95th percentile fetal blood lead concentration (PbB fetal, 0.95), assuming the PbB
adult, central reflects the geometric mean of a lognormal distribution of blood lead concentrations in
women of  child-bearing age.  If a similar 95th percentile goal is applied to the protection of fetuses
carried by women who experience nonresidential exposure, Eguation 2 can be rearranged to reflect a
risk-based goal for the central estimate of blood lead concentrations in adult women using Eguation 3.



where:

PbB adult, central, goal = Goal for central estimate of blood lead concentration (Ig/dL) in adults  (i.e.,
       women of child-bearing age)  that have site exposures.   The goal is intended to ensure that PbB
       fetal,  0.95, goal does not exceed 10 Ig/dL.

PbB fetal, 0.95, goal = Goal for the 95th percentile blood lead concentration  (Ig/dL) among fetuses born
       to women having exposures to the specified site soil concentration.  This is interpreted to mean
       that there is a 95% likelihood that a fetus,  in a woman who experiences such exposures,  would have
       a blood lead concentration no greater than PbB fetal,  0.95,  goal (i.e.,  the likelihood of a blood
       lead concentration greater than 10 Ig/dL would be less than 5%,  for the approach described in this
       report).

GSD i, adult = Estimated value of the individual geometric standard deviation  (dimensionless);
       the GSD among adults (i.e.,  women of child-bearing age)  that have exposures to similar on-site
       lead concentrations,  but that have non-uniform response (intake,  biokinetics)  to site lead and
       non-uniform off-site lead exposures.  The exponent,  1.645,  is the value of the standard normal
       deviate used to calculate the 95th percentile from a lognormal distribution of blood lead
       concentration.

R fetal/maternal  = Constant of proportionality between fetal blood lead concentration at birth and
       maternal blood lead concentration (dimensionless).


The soil lead concentration associated with a given exposure scenario and PbB adult,  central, goal can be
calculated by rearranging Eguation 1 and substituting PbB adult,  central, goal for PbB adult, central:



It is this form of the algorithm that can be used to calculate a RBRG where the RBRG represents the soil
lead concentration  (PbS) that would be expected to result in a specified adult blood lead concentration
(PbB adult, central, goal) and corresponding 95th percentile fetal blood lead concentration

       Eguations 1-4 are based on the following assumptions:

       1.      Blood lead concentrations for exposed adults  ran be estimated as  the sum of an expected
              starting blood lead concentration in the  absence of site exposure (PbB  adult,  0)  and an
              expected site-related increase.

       2.      The site-related increase in blood lead concentrations can be estimated using a linear
              biokinetic slope factor (BKSF)  which is multiplied  by the estimated lead uptake.

-------
3. Lead uptake can be related to soil lead levels using the estimated soil lead concentration
(PbS), the overall rate of daily soil ingestion (IR S), and the estimated fractional
absorption of ingested lead (AF S). The term "soil" is used throughout this document to
refer to that portion of the soil to which adults are most likely to be exposed. In most
cases, exposure is assumed to be predominantly to the top layers of the soil which gives
rise to transportable soil-derived dust. Exposure to soil-derived dust occurs both in
outdoor and indoor environments, the latter occurring where soil-derived dust has been
transported indoors. Other types of dust, in addition to soil-derived dust, can contribute
to adult lead exposure and may even predominate in the occupational setting; these include
dust generated from manufacturing processes (e.g., grinding, milling, packaging of
lead-containing material), road dust, pavement dust, and paint dust. This methodology, as
represented in Eguations 1 and 4, does not specifically account for site exposure to dusts
that are not derived from soil. However, the methodology can be modified to include
separate variables that represent exposure to lead in various types of dust. This approach
is discussed in greater detail in the Appendix.

4. As noted above, exposure to lead in soil may occur by ingesting soil-derived dust in
the outdoor and/or indoor environments. The default value recommended for IR S
(0.05 g/day) is intended for occupational exposures that occur predominantly indoors. More
intensive soil contact would be expected for predominantly outdoor activities such as
construction, excavation, yard work, and gardening.

5. A lognormal model can be used to estimate the inter-individual variability in blood lead
concentrations (i.e., the distribution of blood lead concentrations in a population of
individuals who contact similar environmental lead levels).

6. Expected fetal blood lead concentrations are proportional to maternal blood lead
concentrations.

The primary basis for using Eguation 4 to calculate a RBRG is that fetuses and neonates are a
highly sensitive population with respect to the adverse effects of lead on development and that 10 Ig/dL
is considered to be a blood lead level of concern from the standpoint of protecting the health of
sensitive populations (U.S. EPA, 1986, 1990; NRC, 1993). Therefore, risk to the fetus can be estimated
from the probability distribution of fetal blood lead concentrations (i.e., the probability of exceeding
10 Ig/dL), as has been the approach taken for estimating risks to children (U.S. EPA, 1994a,c). Eguation
4 can be used to estimate the soil lead concentration at which the probability of blood lead
concentrations exceeding a given value (e.g., 10 Ig/dL) in fetuses of women exposed to environmental lead
is no greater than a specified value (e.g., 0.05).

The methodology can be modified to accommodate different assumptions or to estimate RBRGs for
different risk categories. For example, a RBRG could be estimated for risks to adults (e.g.,
hypertension) by substituting an appropriate adult blood lead concentration benchmark. Similarly, other
exposure scenarios can be incorporated into the assessment. Alternative methods for estimating soil lead
risk by partitioning soil into outdoor soil and indoor dust components are discussed in the Appendix.

Recommended default values for each of the parameters in Eguations 1-4 are presented in Table 1.
These defaults should not be casually replaced with other values unless the alternatives are supported by
high guality site-specific data to which appropriate statistical analyses have been applied and that have
undergone thorough scientific review. Examples of the output from the methodology are presented in
Figures 1 and 2, which show plots of the calculated PbB fetal, 0.95 as a function of PbS when different
combinations of default parameter values are used. The rationale for each default value listed in Table
1 is summarized in the Appendix.

-------
         Table 1.  Summary of Default Parameter Values for the Risk Estimation Algorithm  (Equations 1-4)
   Parameter              Unit

PbB fetal, 0.95, goal    Ig/dL

GSD i, adult
R fetal/maternal

PbB adult, 0



BKSF



IR S


EF S



AF S



Ig/dL



Ig/dL
 per
Ig/day

g/day


day/yr
 Value                                            Comment

  10       For estimating RBRGs based on risk to the developing fetus.

  1.8      Value of 1.8 is recommended for a homogeneous population while 2.1 is recommended for
  2.1      a more heterogeneous population.

  0.9      Based on Goyer (1990)  and Graziano et al.  (1990).

1.7-2.2    Plausible range based on NHANES III phase 1 for Mexican American and non-Hispanic
           black, and white women of child bearing age (Brody et al.  1994).  Point estimate should be
           selected based on site-specific demographics.

  0.4      Based on analysis of Pocock et al.  (1983)  and Sherlock et al.  (1984)  data.
 0.05      Predominantly occupational exposures to indoor soil-derived dust rather than outdoor soil,
           (0.05 g/day = 50 mg/day).

  219      Based on U.S. EPA (1993)  guidance for average time spent at work by both full-time and
           part-time workers (see Appendix for recommendations on minimum exposure freguency and
           duration).

 0.12      Based on an absorption factor for soluble lead of 0.20 and a relative bioavailability of 0.6
           (soil/soluble).

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                                              3.  REFERENCES

Balbus-Kornfeld, J.  1994.  Comments and Recommendations on the Draft Interim Guidance for Screening
Levels of Lead in Soil for Non-Residential Sites.  Letter from John Balbus-Kornfeld to Bruce Means.
November 17, 1994.

Bowers, T.S., B.D. Beck and H.S. Karam.  1994.  Assessing the relationship between environmental lead
concentrations and adult blood lead levels.  Risk Analysis.  14(2): 183-189.

Brody, D.J., J.L. Pirkle, R.A. Kramer, K.M. Flegal, T.D. Matte, E.W. Gunter and B.C. Paschal. 1994.
Blood lead levels in the U.S. population.  Phase 1 of the third National Health and Nutrition Examination
Survey (NHANES III, 1988 to 1991).  JAMA.  272(4): 277-283.

Goyer, R.A.  1990.  Transplacental transport of lead.  Environ. Health Perspect.  89: 101-105.

Graziano, J.H., D. Popovac, P. Factor-Litvak, P. Shrout, J. Kline, M.J. Murphy, Y. Zhao, A. Mehmeti, X.
Ahmedi, B. Rajovic, Z. Zvicer, D. Nenezic, N. Lolacono and Z. Stein.  1990. Determinants of elevated
blood lead during pregnancy in a population surrounding a lead smelter in Kosovo, Yugoslavia.  Environ.
Health Perspect.  89: 95-100.

NRC.  1993.  Measuring Lead Exposure in Infants, Children and Other Sensitive Populations. National
Academy Press.  Washington, B.C.  ISBN 0-309-04927-X.

Pocock, S.J., A.G. Shaper, M. Walker, C.J. Wale, B. Clayton, T. Delves, R.F. Lacey, R.F. Packham
and P. Powell.  1983.  Effects of tap water lead, water hardness, alcohol, and cigarettes on blood lead
concentrations.  J. Epi. Comm. Health.  37: 1-7.

Sherlock, J.C., D. Ashby, H.T. Delves, G.I. Forbes, M.R. Moore, W.J. Patterson, S.J. Pocock, M.J. Quinn,
W.N. Richards and T.S. Wilson.  1984.  Reduction in exposure to lead from drinking water and its effect
on blood lead concentrations.  Human Toxicol.  3: 383-392.

U.S. EPA.  1986.  Air Quality Criteria for Lead Volumes I - IV.  Environmental Criteria and Assessment
Office, Office of Research and Development, RTP, NC.  EPA 600/8-83-028 a-d.

U.S. EPA.  1990.  Supplement to the 1986 EPA Air Quality Criteria Document for Lead - Volume 1 Addendum.
Office of Research and Development, Office of Health and Environmental Assessment, Washington, DC.
EPA-600/8-89/049A.

U.S. EPA.  1993.  Superfund's Standard Default Exposure Factors for the Central Tendency and RME-Draft.
Working Draft, November 1993.

U.S. EPA.  1994a.  Revised Interim Soil Lead Guidance for CERCLA Sites and RCRA Corrective Action
Facilities.  OSWER Directive No. 9355.4-12.  Office of Emergency and Remedial Response, Washington, D.C.
EPA/540/F-94/043, PB94-963282.

U.S. EPA.  1994b.  Technical Support Document:  Parameters and Eguations Used in the Integrated Exposure
Uptake Biokinetic Model for Lead in Children  (v. 0.99d).  Office of Emergency and Remedial Response,
Washington, D.C.  EPA/540/R-94/040, PB94-963505.

U.S. EPA.  1994c.  Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in
Children.  Office of Emergency and Remedial Response,  Washington, D.C.  EPA/540/R-93/081, PB93-963510.

U.S. EPA.  1995.  A TRW Report:  Review of a Methodology for Establishing Risk-Based Soil Remediation
Goals for the Commercial Areas of the California Gulch Site.  Technical Review Workgroup for Lead,
October,  1995.

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APPENDIX

Equations and Rationale for Default Values
Assigned to Parameters in the Slope Factor Approach and
Exposure Model for Assessing Risk Associated with Adult
Exposures to Lead in Soil

Eguations and Rationale for Default Values Assigned to Parameters in the
Slope Factor Approach and Exposure Model for Assessing Risk Associated
with Adult Exposures to Lead in Soil

1. Equations for the Adult Lead Model A-3

2. Individual Blood Lead Geometric Standard Deviation (GSD i) A-6

3. Fetal/Maternal Blood Lead Concentration Ratio (R fetal/maternal) A-8

4. Baseline Blood Lead Concentration (PbB adult, 0) A-8

5. Biokinetic Slope Factor (BKSF) A-10

6. Soil Lead Absorption Factor (AF S) A-15

7. Daily Soil Ingestion Rate (IR S) A-19

8. Exposure Frequency (EF S) A-22

9. Applying Monte Carlo Analysis to the Adult Lead Methodology A-23

10 . References A-25

1. Equations for the Adult Lead Model

The format of the equations used in the adult lead methodology follows the approach used in the
IEUBK Model for Lead in Children (IEUBK Model). Note that the equations may consist of variables that
include superscripts and/or subscripts. The convention adopted in this report is to use superscripts as
exponents (i.e., a mathematical operation), whereas subscripts represent key words that provide
additional information to distinguish between similar variables. The term "soil" refers to that portion
of the soil to which adults are most likely to be exposed. In most cases, exposure is assumed to be
predominantly to the top layers of the soil which gives rise to transportable soil-derived dust.
Exposure to soil-derived dust has been transported indoors. Other types of dust, in addition to
soil-derived dust, can contribute to adult lead exposure and may even predominate in some occupational
settings; these include dust generated from manufacturing processes (e.g., grinding, milling, packaging
of lead-containing material), road dust, pavement dust, and paint dust.

Exposure to lead from soil (direct and through indoor soil-derived dust) and lead intake:

PbS D IR S D EF S
INTAKE = (Equation A-l)
AT

INTAKE = Daily average intake (ingestion) of lead from soil taken over averaging time AT
(Ig/day).

PbS = Soil lead concentration (Ig/g) (appropriate average concentration for individual).

IR S = Intake rate of soil, including outdoor soil and indoor soil-derived dust (g/day).

EF S = Exposure frequency for contact with assessed soils and/or dust derived in part from
these soils (days of exposure during the averaging period); may be taken as days per
year for continuing, long term exposures.

-------
AT     =  Averaging time; the total period during which soil contact may occur; 365 days/year
          for continuing long term exposures.

    Lead uptake:


             UPTAKE = AF S D INTAKE                                           (Eguation A-2)


UPTAKE =  Daily average uptake of lead from the gastrointestinal tract into the systemic
       circulation (Ig/day)

AF S   =  Absolute gastrointestinal absorption fraction for ingested lead in soil and lead in dust
       derived from soil (dimensionless).


     Central estimate of adult blood lead concentration:


      PbB adult, central = PbB adult, 0 + BKSF D UPTAKE                       (Eguation A-3)


PbB adult, central =  Central estimate of blood lead concentrations  (Ig/dL) in adults (i.e., women of
       child-bearing age) that have site exposures to soil lead at concentration,  PbS.

PbB adult, 0 = Typical blood lead concentration (Ig/dL) in adults  (i.e., women of child-bearing
       age)  in the absence of exposures to the site that is being assessed.

BKSF = Biokinetic slope factor relating (guasi-steady state) increase in typical adult blood lead
       concentration to average lead uptake (Ig/dL blood lead increase per Ig/day lead uptake).

Distributional model for adult blood lead:

       In this methodology,  variability in blood lead concentrations among a population is
mathematically described by a lognormal distribution defined by two parameters, the geometric mean  (GM)
and the geometric standard deviation (GSD):

                       PbB,  adult ~ Lognormal(GM, GSD)


PbB adult =  Adult blood lead concentration  (which is a variable guantity having the specified
             probability distribution).

GM        =  Geometric mean blood lead concentration (Ig/dL) for adults having site exposure.
              The central estimate of adult blood lead.  PbB adult, central,  constructed in Eguation A-3
              is treated as  a plausible estimate of the geometric mean.

GSD       = Geometric standard deviation for blood lead concentrations among adults having
            exposures to similar on-site lead concentrations, but having non-uniform response
            (intake,  biokinetics) to site lead and non-uniform off-site lead exposures.   The
             individual blood lead concentration geometric standard deviation, GSD i,  is substituted for
              GSD.  As described below  (Section 2  of the Appendix), GSD i is  assumed to  address  sources of
              variability in blood lead concentrations  among the exposed population.

Parameter estimates for the geometric mean  (GM) and geometric standard deviation  (GSD)  of the
lognormal distribution are described below.  Note that blood lead concentrations for site exposures can
be guantified at any percentile of the population using these parameters.  For example,  the 95th
percentile blood lead concentration can be calculated by Eguation A-4.



PbB adult, 0.95 = 95th percentile blood lead concentration  (Ig/dL) among individuals having exposures to
       the specified site soil lead concentrations.  This is interpreted to mean that there is a 95%
       likelihood that an adult exposed to the specified soil lead concentrations would have a blood lead
       concentration less than or egual to PbB adult, 0.95.

-------
Distributional model for fetal blood lead:

PbB fetal = R fetal/maternal D PbB adult (Equation A-5)

PbB adult = 95th percentile blood lead concentration (Ig/dL) (which, like PbB adult, is a variable
quantity havinq the specified probability distribution).

R fetal/maternal = Constant of proportionality between fetal and maternal blood lead concentrations.

PbB adult = Adult blood lead concentration (Ig/dL), estimated with parameters appropriate to women of
child bearing aqe.

Note that this relationship implies a deterministic (non-random) relationship between maternal and fetal
blood lead concentrations. This assumption omits a source of variability (varyinq individual-specific
ratios of fetal to maternal blood lead) that would tend to increase the variance of fetal blood lead
concentrations. The assumption of proportionality implies that fetal blood lead concentrations also are
loqnormally distributed:

PbB fetal ~ Loqnormal (GM,GSD)

GM = Geometric mean blood lead concentration (Ig/dL) for fetuses, equal to R fetal/maternal multiplied
by PbB adult, central.

GSD = Geometric standard deviation of blood lead concentration amonq adults. GSD i (Section 2 of the
Appendix).

Similarly, percentiles of the fetal blood lead distribution can be estimated (for fetuses carried by
women exposed to the specified concentration of lead at the assessed site). For example:

Equation A-7 represents variability in blood lead concentration arisinq from two main factors: 1)
exposure variables, includinq inter-individual variability in activity-weiqhted inqestion rates, and 2)
inter-individual variability in physioloqy, includinq factors affectinq lead biokinetics.

2. Individual Blood Lead Geometric Standard Deviation (GSD i)

The GSD i is a measure of the inter-individual variability in blood lead concentrations in a
population whose members are exposed to the same nonresidential environmental lead levels. Ideally, the
value(s) for GSD i used in the methodoloqy should be estimated in the population of concern at the site.
This requires data on blood lead concentration and exposure in a representative sample of sufficient size
to yield statistically meaninqful estimates of GSD in subsamples stratified by nonresidential exposure
level. In the absence of hiqh quality data for the site, GSD i may be extrapolated from estimates for
other surroqate populations. In makinq such extrapolations, factors that miqht contribute to hiqher or
lower variability in the surroqate population than amonq similarly exposed individuals in the population
of concern, should be evaluated. These factors include variability in exposure (level and pathways), and
biokinetics (see Section 6 of Appendix), socioeconomic and ethnic characteristics, deqree of urbanization
and qeoqraphical location. Such extrapolations, therefore, are site-specific and are a potentially
important source of uncertainty in the methodoloqy.

GSD values measured in populations (GSD P) reflect the combined effect of 1) variability in
environmental concentration levels; and 2) activity-weiqhted exposures and lead biokinetics. Thus,
estimates of GSD P can be considered a surroqate for estimatinq the GSD i. Site data on blood lead
concentrations collected from populations of varyinq homoqeneity may be useful for establishinq a
plausible ranqe of values of GSD i, provided that the data are of adequate quality and can be stratified
by nonresidential exposure level. The lowest values of GSD P are expected amonq homoqeneous populations
(e.g., individuals with similar socioeconomic and ethnic characteristics living within a relatively small
qeoqraphic area) exposed to a sinqle, dominant source of lead (e.g., lead mining or smelter sites). For
example, a GSD P of 1.8 was recently calculated amonq adult women livinq in Leadville, CO (U.S. EPA,
1995). This relatively low GSD is consistent with an analysis of blood lead concentration data in mininq
communities in the United States and Canada, which suqqest that GSD P ranqes from 1.6 - 1.8 at active
mininq sites where blood lead concentrations are less than 15 Ig/dL (U.S. EPA, 1992). By contrast,
hiqher values of GSD P miqht be expected from a national survey. Althouqh lead exposures amonq the
qeneral population are likely to be more qreatly impacted by diet than soil (e.g., compared with
populations exposed at a waste site) , the national population is very heteroqeneous, in that it includes

-------
individuals with different socioeconomic and ethnic characteristics living in distinct geographic areas.

The TRW has conducted a preliminary analysis of blood lead concentration data collected in NHANES
III Phase 1 from 1988 to 1991 and found that the GSD P for women ages 17 to 45 years may range from 1.9 -
2.1 (Table A-l). Because of the complex survey design used in NHANES III (e.g., large oversampling of
young children, older persons, black persons, and Mexican-Americans), this analysis used sampling weights
included in the NHANES III Phase 1 data file to produce population estimates for blood lead
concentration. The weighting factor "WTPEXMH1" was used to reflect the non-random sampling of
individuals in both the mobile examination units (MEG) and the home examinations. The analysis did not
account for the design effects associated with the selection of strata and primary sampling units (PSU
S), which may result in an underestimation of sampling variance. Since this bias is not likely to
greatly impact the GSD P (Brody, personal communication), the amount of underestimation of the GSD P by
the values given in Table A-l is likely to be small. Geometric mean blood lead concentrations listed in
Table A-l are within 0.2 Ig/dL of these reported in Brody et al. (1994).

The TRW estimates that 1.8 - 2.1 is a plausible range for GSD i, based on an evaluation of
available blood lead concentration data for different types of populations. In cases where site-specific
data are not available, a value within this range should be selected based on an assessment as to
whether the population at the site would be expected to be more or less heterogeneous than the U.S.
population with respect to racial, ethnic, cultural and socioeconomic factors that may affect exposure.

Table A-l. NHANES III Phase 1 Summary Statistics for Blood Lead Concentration Among U.S.
Women by Age and Ethnic/Racial Characteristics a

Age Group Non-Hispanic White Non-Hispanic Black Mexican American
(years) No. GM GSD No. GM GSD No. GM GSD
20-49 728 1.9 1.90 622 2.3 2.01 729 2.1 2.10
50-69
> 69
20+
17-45
476
562
1,766
742
3.2
3.5
2.4
1.7
1.
1.
2.
1.
,88
,82
,01
,89
256
135
1,013
658
4.2
4.1
2.7
2.1
1,
1,
2,
1,
.80
.86
.07
.98
255
75
1,059
763
3.3
2.9
2.3
2.0
2.12
2.03
2.14
2.10
a Analysis of data weighted by MEG and home weighting factor (WTPEXMH1) , excluding samples
missing data on blood lead concentration or age. GM PbB (Ig/dL) = exp(I In); GSD PbB = exp(o In).

3. Fetal/Maternal Blood Lead Concentration Ratio (R fetal/maternal)

The TRW recommends a default value of 0.9 based on studies that have explored the relationship
between umbilical card and maternal blood lead concentrations (Gover, 1990; Graziano et al., 1990). The
Goyer (1990) estimate of an average fetal/maternal blood lead concentration ratio of 0.9 is supported by
a large body of data that has been summarized in Agency documents (U.S. EPA, 1986, 1990). Graziano et
al. (1990) compared maternal and umbilical cord blood lead concentrations at delivery in 888
mother-infant pairs who were between 28 and 44 weeks of gestation. The relationship was linear with a
slope of 0.93 Ig/dL cord blood per Ig/dL maternal blood; the correlation coefficient was 0.92. The slope
of 0.93 from the Graziano et al. (1990) study supports 0.9 as a point estimate for R fetal/maternal.

Although average fetal/maternal blood lead concentration ratios, as reflected in cord blood, tend
to show consistent trends (Goyer, 1990, Graziano et al., 1990), the trends may not reflect significant
inter-individual variability in maternal and possibly fetal blood lead concentrations due to
physiological changes associated with pregnancy. For example, mobilization of bone lead stores during
pregnancy may be more substantial in some women, and iron and calcium deficiency associated with poor
nutritional status, as well as pregnancy, may enhance gastrointestinal absorption of lead (U.S. EPA,
1990; Franklin et al., 1995). Conversely, maternal blood lead concentration may decrease during the
later stages of pregnancy because of the dilution effect associated with a 30% rise in plasma volume, as
well as an increased rate of transfer of lead to the placenta or to fetal tissues (Alexander and Delves,
1981). These changes may give rise to fetal/maternal blood lead concentration ratios that are different
from 0.9.

4. Baseline Blood Lead Concentration (PbB adult, 0)

The baseline blood lead concentration (PbB adult, 0) is intended to represent the best estimate of
a reasonable central value of blood lead concentration in women of child-bearing age who are not exposed
to lead-contaminated nonresidential soil or dust at the site. In this analysis, geometric mean blood

-------
lead concentrations are used for this purpose. Ideally, the value(s) for PbB adult, 0 used in the
methodology should be estimated in the population of concern at the site. This requires data on blood
lead concentrations in a representative sample of adult women who are not exposed to nonresidential soil
or soil-derived dust at the site but who may experience exposures to other environmental sources of lead
that are similar in magnitude to exposures experienced by the population of concern. This would include
exposure to lead in food and drinking water as well as residential soil and dust (dust derived from soil
and all other non-site related sources). The sample must be of sufficient size to yield statistically
meaningful estimates of PbB adult, 0.

In the absence of high quality data for the site, PbB adult, 0 may be extrapolated from estimates
for other surrogate populations that would be expected to have a similar PbB adult, 0 distribution as
that of the population of concern. In making such extrapolations, factors that might contribute to
differences between the geometric mean PbB adult, 0 in the surrogate population and population of concern
should be evaluated. These factors include differences in the residential exposure (level and pathways),
socioeconomic, ethnic and racial demographics, housing stock, degree of urbanization, and geographical
location. Such extrapolations, therefore, are site-specific.

In cases where site-specific extrapolations from surrogate populations are not feasible, the TRW
recommends 1.7 - 2.2 Ig/dL as a plausible range, based on the results of Phase 1 of the NHANES III as
reported by Brody et al. (1994). Table A-2 summarizes the analysis of blood lead
concentrations from a sample of 2,083 women ages 20 - 49, and stratified int the three ethnic and racial
categories.

Table A-2. NHANES III Phase 1 Summary Statistics for Blood Lead Concentration Among Different
Populations of U.S. Women Ages 20 - 49 (Brody et al., 1994).

Population No. GM (95% CI)
Mexican American women 732 2.0 (1.7 - 2.5)
non-Hispanic black women 623 2.2 (2.0 - 2.5)
non-Hispanic white women 728 1.7 (1.6 - 1.9)

Total 2,083

The TRW recommends that the estimates from Table A-2 be used in combination with data on the ethnic and
racial demographics of the population of concern to select the most appropriate point estimate from
within the plausible range of 1.7 - 2.2 I/dL. For example, if the population at the site was
predominantly Mexican American, 2.0 Ig/dL might be selected as the point estimate. The plausible range
is based on surveys of large samples of the national population and may not encompass central tendencies
estimated from smaller regional or site-specific surveys, either because of bias associated with the
smaller sample or because of real differences between the surveyed population and the national
population. This needs to be evaluated in deciding whether or not to use data from small surveys that
yield point estimates for PbB adult, 0 that fall outside of the plausible range.

5. Biokinetic Slope Factor (BKSF)

The BKSF parameter relates the blood lead concentration (Ig Pb/dL) to lead uptake (Ig Pb/day).
The TRW recommends a default value of 0.4 Ig Pb/dL blood per Ig Pb absorbed/day for the BKSF parameter
based on data reported by Pocock et al. (1983) on the relationship between tap water lead concentrations
and blood lead concentrations for a sample of adult males, and on estimates of the bioavailability of
lead in tap water (see Section 6 of the Appendix).

Pocock et al. (1983) analyzed data on lead concentrations in first draw tap water and blood lead
concentrations in a population of 910 adult males. A linear model imposed on the data yielded a slope of
0.06 (Ig/dL per Ig/L first draw water) for water lead concentrations equal to or less than 100 Ig/L (a
lower slope was applied to the data for higher water concentrations) . Pocock et al. (1983) also obtained
data on lead concentrations in flushed water (and "random daytime") samples, in addition to first draw
samples. Given the following assumptions, it is possible to derive a slope factor for ingested water
lead (INGSF) from the Pocock et al. (1983) data:

• The lead concentration of flushed water was 25% of the concentration of first draw water ©
alst = 0.25) (U.S. EPA, 1995) .

Daily water intake consisted of 30% first draw and 70% flushed (F 1st = 0.3, F f = 0.7)(U.S.
EPA, 1992).

-------
       •      Daily water ingestion (including tap water and beverages made with tap water)  was 1.4 L/day
              (IR W = 1.4)  (U.S.  EPA,  1989).

Based on the above assumptions, a INGSF of 0.09 Ig/dL per Ig intake/day is estimated as follows:

                               0.06                                             (Eguation A-8)
          INGSF =
                  IR W D (F 1st +  (C alst D F a))

                               0.06
          INGSF =
                  1.4 D  (0.3 + (0.25 D 0.7))

          INGSF =0.09

This suggests that the product of the BKSF, reflecting the slope for absorbed rather than ingested lead,
and the absorption factor for lead in drinking water  (AF W)  should be approximately 0.09 if it is to
match the estimate of INGSF based on the Pocock et al.  (1983) study:

               INGSF = BKSF D AF W                                               (Eguation A-9)


Values of AF W withing the range 0.20 - 0.25 would correspond to a range for BKSF of 0.36 - 0.45, or
approximately 0.4 Ig/dL per Ig/day  (rounded to one significant figure).  A range of 0.20 - 0.25 for AF W
is supported by data from numerous lead bioavailability studies  (see Section 6 of the Appendix for a more
detailed discussion of these studies).

       The above estimate of 0.4  Ig/dL per Ig/day for the BKSF can be compared with the approach
described by Bowers et al.  (1994), who used the same data set along with different assumptions and
arrived at essentially the same estimate of the BKSF, 0.375 or approximately 0.4 Ig/dL per Ig/day.
Bowers et al. (1994) assumed a daily tap water intake of 2 L/day and 8% absorption of lead ingested in
tap water; and did not make adjustments for a mixture of first draw and flushed water intake in the
Pocock et al. (1983) study.

       Several uncertainties should be considered in applying the default value of 0.4 Ig/dL per
Ig/day to any specific population.  Since it is based on the Pocock et al.  (1983) data, it represents an
extrapolation from adult men to women of child bearing age.   Physiological changes associated with
pregnancy may affect the value of the BKSF (see Section 6 of the Appendix); therefore, some uncertainty
is associated with applying the default value to populations of pregnant women.

       An additional uncertainty concerns the assumption of linearity of the relationship between lead
intake and blood lead concentration.  The Pocock et al.  (1983) study provides data on a large sample
population of adult men whose members were exposed to relatively low drinking water lead levels; 898
subjects  (97%) were exposed to first draw water lead concentrations less than 100 Ig/L and 473  (52%) to 6
Ig/L or less.  A smaller study of adult women exposed to higher concentrations was reported by Sherlock
et al.  (1982, 1984); out of 114 subjects, 32  (28%) had flush drinking water lead concentrations less than
100 Ig/L and only 13 (11%)  less than 10 Ig/L.  Sherlock et al. (1982, 1984) used a cube root regression
model, rather than a linear model, to describe the relationship between drinking water and blood lead
concentration.  Given the much larger sample size in the Pocock et al.  (1983) study, particularly towards
the low end of the distribution for water lead concentration, greater confidence can be placed in the
estimated slope of the linear regression model from the Pocock et al. (1983) study than in the cube root
regression model of Sherlock et al. (1982, 1984) .  Nevertheless, it is useful to compare the output of the
two models because they were applied to the different sexes and because they differ so fundamentally in
the treatment of the blood lead - water lead slope; the slope is constant in the linear model and
decreases in the cube root model as water lead concentration increases.  Figure A-l compares the output
of the two models and shows the output of a linear regression of the unweighted output of the Sherlock et
al. (1984) model.  Three observations can be made from this comparison that are relevant to the BKSF:

       1.      Both the  Pocock et  al.  (1983)  and Sherlock et  al.  (1984)  models predict higher blood
              suggested from NHANES III.   This is  indicative of higher lead intakes in the study
              populations which may have  contributed to  the  apparent nonlinearities observed (e.g.  above
              100 Ig/L  in Pocock  et al.(1983)  and  at lower concentrations in Sherlock et al.  (1984).

       2.      The cube  root regression model  of Sherlock et  al.  (1984)  predicts lower blood lead
              concentrations  than the  linear  model of Pocock et al.  (1983).   This may reflect greater lead
              intakes from sources other  than drinking water in the Pocock et al. (1983)  population (see
              Section 6 of  the Appendix for further discussion).

-------
       3.
      The  linear approximation of the  Sherlock et al.  (1984)  and the  linear model  from Pocock et
      al.  (1983)  have  similar slopes:   0.08  and 0.06  Ig/dL per Ig/L,  respectively.  Thus,  although
      the  Sherlock et  al.  (1984)  study casts some degree of uncertainty on the assumption of
      linearity of the blood lead -  drinking water lead relationship  both at low (<10  Ig/L)  and
      high (> 100 Ig/L)  tap water lead concentrations,  a linear model with a constant  slope  of
      0.06 Ig/dL per Ig/L  appears to approximate the  output of the nonlinear model  of  Sherlock et
      al.  (1984)  reasonably well  for water lead concentrations less than 100 Ig/L.

Figure A-l.  Comparison of linear model of Pocock et al.   (1983) with cube root model of Sherlock
et al. (1984) and a linear model imposed on the unweighted output of the Sherlock model over the
water lead range 0 - 100 Ig/L (linear Sher84).  The slope of the linear Sher84 model is 0.08 Ig/dL per
Ig/L.  The slope of the Pocock et al.  (1983)  model is 0.06 Ig/dL per Ig/L.

       Experimental data on the pharmacokinetics of lead in adult humans support the default value of 0.4
(Ig/dL per Ig/day absorbed lead) for BKSF estimated from Pocock et al.  (1983).  Several distinct kinetic
pools of lead are evident from observations of the rate of change of blood lead isotope with time after a
period of daily dosing in which lead is abruptly terminated  (Rabinowitz et al., 1976). A rapid exchange
pool, denoted pool 1, includes the blood and a portion of the extracellular fluid, and is the
physiological pool from which urinary and hepatobiliary excretion of blood lead occurs. Several estimates
of the size of pool 1 (VI) and the residence times for lead in pool 1  (T 1) have been derived from
experiment in which human subjects were administered tracer doses of stable isotopes of lead from which
pool 1 clearances  (C 1)  have been estimated;  these estimates are summarized in Table A-3.


           Table A-3.  Summary of Experimental Studies with Humans to Assess Clearance Rates of
                                 Lead from Blood and Extracellular Fluid.
                                                              Reference
                                                         Rabinowitz et al.,  1974
                                                         Rabinowitz et al.,  1976
                                                         Chamberlain et al. ,  1978
Subject


   A

   B

   A

   B

   C

   D

   E

  ACC

  DN

  PL

  ACW

  MJH

  ANB
    a The reported volume of pool 1, which refers to blood and rapidly exchangeable extracellular fluid
       compartment.
    b The reported residence time for lead in pool 1.
    c The half life of lead in pool 1; T E = (T 1) x ln(2).
    d Clearance of lead from pool 1; C 1 = V 1/T 1.
    e Estimated assuming V 1 = V blood x 1.7 (Rabinowitz et al. ,  176).
Via
(dL)
77
115
74
100
101
99
113
70 e
94 e
85 e
94 e
97 e
95 e
93 " 14
Tib
(day)
34
50
34
40
37
40
27
29
39
40
48
41
40
38 " 6
T E c
(day)
24
35
24
28
26
28
19
20
27
28
33
28
28
27 " 4
C 1 d
(dL/day)
2.3
2.3
2.2
2.5
2.7
2.5
4.2
2.4
2.4
2.1
2.0
2.4
2.4
2.5 " 0.5

-------
The above experiments support a value for C 1 of 2.5 dL/day. At steady state, the clearance is
equivalent to the rate of uptake of lead into pool 1 per unit of blood lead concentration (Ig/day per
Ig/dL). Theoretically, this should correspond to a slope factor of 0.40 Ig/dL per Ig/day absorbed lead
(i.e., the reciprocal of the clearance estimate). Thus, the default value for the BKSF parameter of 0.4
Ig/dL per Ig/day absorbed lead derived from the population survey data of Pocock et al. (1983) is
consistent with the clearance estimates from experimental studies.

6. Soil Lead Absorption Factor (AF S)

The AF S parameter is the fraction of lead in soil ingested daily that is absorbed from the
gastrointestinal tract. The TRW recommends a default value of 0.12 based on the assumption that the
absorption factor for soluble lead (AF soluble) is 0.2 and that the relative bioavailability of lead in
soil compared to soluble lead (RBF soil/soluble) is 0.6:

AF S = AF soluble D RBF soil/soluble (Equation A-10)

AF S = 0.2 D 0.6 = 0.12

The default value of 0.2 for AF soluble in adults represents a weight of evidence determination based on
experimental estimates of the bioavailability of ingested lead in adult humans with consideration of
three major sources of variability that are likely to be present in populations, but are not always
represented in experimental studies; these are variability in food intake, lead intake, and lead form and
particle size.

Effect of food on lead bioavailability. The bioavailability of ingested soluble lead in adults
has been found to vary from less than 10% when ingested with a meal to 60 - 80% when ingested after a
fast (Blake, 1976; Blake et al. , 1983; Blake and Mann, 1983; Graziano et al., 1995; Heard and
Chamberlain, 1982; James et al., 1985; Rabinowitz et al., 1976, 1980). The general consensus is that
constituents of food in the gastrointestinal tract decrease absorption of ingested lead, although the
exact mechanisms by which this occurs are not entirely understood. Lead intake within a population would
be expected to occur at various times with respect to meals. Therefore, the central tendency for lead
absorption would be expected to reflect, in part, meal patterns within the population and to have a value
between the experimentally determined estimate for fasted and fed subjects.

An estimate of a "meal-weighted" AF soluble can be obtained from the data reported by James et al.
(1985) and certain simplifying assumptions. James et al. (1985) assessed the effects of food on lead
bioavailability by measuring the fraction retained in the whole body of adults subjects 7 days after they
ingested a dose of radioactive lead either after a fast or at various times before or after a meal. The
total lead dose was approximately 50 Ig (fasted) - 100 Ig (with food). Lead retention was 61 " 8.2 (SD)%
when lead was ingested on the 12th hour of a 19-hour fast and decreased to 4% - 16% when lead was
ingested between 0 and 3 hours after a meal; retention was further reduced (3.5 " 2.9%) when lead was
ingested with a meal (breakfast) (the bioavailability may have been more than these retention estimates
since some absorbed lead would have been excreted during the 7 day interval between dosing and
measurement of whole-body lead). Since ingested material may be retained in the human stomach or at
least 1 hour (Hunt and Spurrel, 1951; Davenport, 1971) , lead bioavailability also may be reduced when
lead is ingested 1 hour before a meal. The average "meal-weighted" bioavailability can be estimated
based on the average number of waking hours during the day, the number of meals eaten, the
bioavailability of lead ingested within 1 hour before a meal, the bioavailability of lead ingested within
0 to 3 hours after a meal, and the bioavailability of lead at other times during the day. For example,
if it is assumed that people eat three meals each day and, based on the James et al. (1985) study, the
bioavailability of lead ingested within 1 hour before a meal or 0 to 3 hours after a meal is
approximately 0.1, and the bioavailability of lead ingested at all other times in a 16 hour day is 0.6,
then the average "meal-weighted" bioavailability during a 16 hour day is approximately 0.2:

(0.1 D 12 hrs) + (0.6 D 4 hrs)
= 0.23
16 hrs

This example suggests that the use of 0.2 as a default value for AF soluble is plausible for
populations in which soil lead intake occurs throughout the day, interspersed with meals. This may not
apply to all members of a population. For example, the average bioavailability would be higher if less
than three meals were consumed each day (e.g., using a similar calculation it can be shown that the
average bioavailability for one meal each day would be 0.5). Average bioavailability also may be greater
than 0.2 if lead intake was to occur predominantly in the early morning, before the first meal of the
day.

-------
Although lead bioavailability may be lower in individuals whose soil lead ingestion coincides with
meals, the TRW cautions against the use of a value less than 0.2 for several reasons. Iron and calcium
deficiency associated with poor nutritional status may enhance absorption (U.S. EPA, 1990). In addition,
numerous factors may affect the absorption, distribution, excretion, and mobilization of lead during
pregnancy: increased plasma volume (i.e., hemodilution); decreased hematocrit; previous exposure history
of the mother (i.e., bone lead seguestration); changes in nutritional status; significant loss of body
weight of depletion of fat stores; hormonal modulation; age; race; administration of drugs; and illness
(Silbergeld, 1991). There is likely to be significant inter-individual variability in these factors, and
studies of women at different stages of pregnancy have not shown clear trends in effects on blood lead
concentration (Gershanik et al., 1974; Alexander and Delves, 1981; Baghurst et al. , 1987; Silbergeld,
1991). While there is evidence to support 0.2 as a reasonable estimate of AF soluble for women of
child-bearing age, there is still some basis for concern regarding potentially elevated absorption during
pregnancy. However, a potential increase in lead absorption during pregnancy would be expected to occur
dynamically with changes in bone mobilization, blood volume and glomerular filtration rate. Thus, the
TRW cautions against adjusting the value for AF soluble (or BKSF) based on assumptions regarding the
effects of pregnancy on blood lead concentration.

Nonlinearity in blood lead concentration. Another reason for caution in adopting values for AF
soluble less than 0.2 derives from uncertainty about the relationship between blood lead concentration,
lead intake, and lead absorption. Several studies have shown that the relationship between environmental
lead levels (e.g., drinking water lead concentration) and blood lead concentration is nonlinear and
suggest the possibility that fractional absorption of ingested lead is dose-dependent and decreases as
lead intake (and blood lead concentration) increases. Pocock et.al. (1983) reported a nonlinear
relationship between blood lead concentration and water lead that could be approximated by two linear
eguations: a slope of 0.06 Ig/dL per Ig/L was estimated for water lead concentrations above 100 Ig/L and
a slope of 0.01 was estimated for lead concentrations above 100 Ig/L. Sherlock et al. (1982, 1984) used
a cube root regression model to relate blood and water lead concentrations; however, over the range of
water lead concentrations of 100 Ig/L or less, the slope of 0.06 Ig/dL per Ig/L water lead from Pocock et
al. (1983) approximates the relationship observed in the Sherlock et al. (1982, 1984) study (Figure A-l).
The linear relationship between water lead and blood lead in the Pocock et al. (1983) study extends from
a blood lead concentration range of 14 to 20 Ig/dL. Based on these data, the value of AF soluble of 0.2
may be considered a reasonable default estimate if applied to exposure scenarios in which the estimates
of blood lead concentration do not exceed 20 Ig/dL. At blood lead concentrations greater than this,
absorption of soluble lead may be less than the default value.

An appropriate value of AF soluble also can be supported by estimating the range of daily lead
intake that is likely to result in a linear relationship between intake and blood lead concentration.
Data represented in Figure A-l suggest that if water lead concentrations are less than 100 Ig/L, the
blood lead - water lead relationship is approximately linear. If assumptions regarding the magnitude of
first draw and flushed water intakes and lead concentrations are applied (see Eguations A-8 and A-9 and
discussion of BKSF), a first draw water lead concentration of 100 Ig/L in the Pocock et al. (1983) study
represents a water lead intake of approximately 70 Ig/day:

100 D 1.4 D (0.3 + (0.25 D 0.7)) = 70

We do not know with certainty the total lead intake in the Pocock et al. (1993) population,
although we can be certain that it exceeded the above estimated intake from drinking water since intake
from diet and other sources, including occupational, would have occurred; this is consistent with the
higher blood lead concentrations that were observed in the male population. Sherlock et al. (1982)
estimated that, in their study population of adult women, the dietary contribution to total lead intake
was egual to that from drinking water when the water lead concentration was 100 Ig/L, and that the
contribution of lead from sources other than diet and water was very small. If the same assumption is
applied to the Pocock et al. (1983) study, it is likely that total lead intake in the male population was
at least 140 Ig/day (70 Ig/day from drinking water and 70 Ig/day from diet; the Pocock et al., 1983 study
included 40 households from the Sherlock et al., 1982 study site), and may have been higher because of
occupational exposure in the male population. A crude estimate of the relative magnitudes of the
non-water lead intakes in the two studies can be obtained by comparing the predicted water lead
concentration reguired to achieve the same blood lead concentration in the two populations. For
example, a water lead concentration of 100 Ig/L corresponded to a predicted blood lead concentration of
approximately 18 Ig/dL in the female population (Sherlock et al., 1984); the same blood lead
concentration corresponded to a water lead concentration of 50 Ig/L in the male population (Pocock et
al. , 1983) . Therefore, the non-water lead intakes in the male population may have been twice that in the
female population. If it is assumed that drinking water and diet contributed egually to lead intake in
both studies, then a drinking water lead concentration of 100 Ig/L in the Pocock et al. (1983) study
translates to a total lead intake of approximately 300 Ig/day:

-------
I total = I water - I diet - I other (Equation A-ll)

I total = 70 + 70 - 140 = 300 Ig/day

Thus, the departure from linearity observed in the Pocock et al. (1983) study may have occurred at lead
intakes at or above 300 Ig/day. In the various experimental assessments of lead bioavailability,
subjects ingested lead in amounts that varied among the studies but were all within the range 100-300 Ig
(Blake, 1976; Blake et al. , 1983; Blake and Mann, 1983; Graziano et al., 1995; Heard and Chamberlain,
1982; James et al., 1985; Rabinowitz et al., 1976, 1980), which is within the approximate linear range,
if the extrapolation from the Pocock et al. (1983) and Sherlock et al. (1982) studies is reasonable.
Based on these considerations, the value of AF soluble of 0.2 is considered to be a reasonable default
value if applied to exposure scenarios in which lead intakes are less than 300 Ig/day. At intakes
greater than this, absorption of soluble lead may be less than the default value; however, it can be
similarly argued that, based on the Sherlock et al. (1984) regression model, the default AF soluble may
underestimate absorption by some degree at low exposures.

Effect of lead form and particle size on lead bioavailability. The default value of 0.2 for AF
soluble applies to soluble forms of lead in drinking water and food and would be expected to overestimate
absorption of less soluble forms of lead in soil. Experimental studies have shown that the
bioavailability of lead in soil tends to be less than that of soluble lead. Weis et al. (1994) assessed
the relative bioavailability of lead in soil compared to water soluble lead (acetate) in immature swine
and estimated that the relative bioavailability of lead in soil from Leadville, CO was 0.6 to 0.8. Ruby
et al. (1996) reported estimates of the relative bioavailability of lead in a variety of soils from
mining sites and smelters as assessed in the Sprague-Dawley rat; the estimates ranged from 0.09 to 0.4.
Maddaloni et al. (1996) reported preliminary data from a study in which 6 fasted human subjects were
administered a single dose of lead-contaminated soil. The dose was 250 Ig lead normalized to a 70 kg
body weight; the concentration of lead in the soil was 2850 Ig/g and the amount of soil administered to
each subject was generally a little less than 100 mg. The average estimate of lead absorption in the six
subjects was 26%. If the absorption factor for soluble lead in fasted adults is assumed to be 0.6 (James
et al., 1985), then the Maddaloni et al. (1996) estimate suggests a relative bioavailability of 0.5
(i.e., 0.3/0.6) for lead in soil.

Based on the above evidence, the TRW considers 0.6 to be a plausible default point estimate for
the relative bioavailability of lead in soil compared to soluble lead (RBF soil/soluble) when
site-specific data are not available. Such data are highly desirable as variation in relative
bioavailability is expected for different species of lead and different particle sizes (Barltrop and
Meek, 1975, 1979), both of which may vary from site to site. For example, the bioavailability of
metallic lead has been shown to decrease with increasing particle size (Barltrop and Meek, 1979),
therefore, the default value for RBF soil/soluble may overestimate absorption of lead if applied to soils
contaminated with large lead particles such as firing range debris or mine tailings. Here again, the TRW
cautions against the use of a lower value for the RBF soil/soluble, unless it can be supported by
experimental assessments of relative bioavailability.

The default value of 0.6 for RBF soil/soluble coupled with the default value of 0.2 for AF soluble
yields a default value of 0.12 for AFS (0.6 DO.2). The TRW considers 0.12 to be a plausible point
estimate for the absorbed fraction of ingested soil lead for use in assessments in which site-specific
data on lead bioavailability are not available. The default value of 0.12 takes into account
uncertainties regarding the possible nonlinearity in the relationship between lead intake and absorption
and should be adequately protective in scenarios in which predicted blood lead concentrations are less
than 20 Ig/dL. The use of the default value for populations that have substantially higher blood lead
concentrations may result in an overestimate of lead uptake, and conversely, lead uptake may be
underestimated at lower exposures.

7. Daily Soil Ingestion Rate (IR S)

The TRW recommends a default value of 0.05 g/day as a plausible point estimate of the central
tendency for daily soil intake from all occupational sources, including soil in indoor dust, resulting
from non-contact intensive activities. This would include exposures that are predominantly indoors.
More intensive soil contact would be expected for predominantly outdoor activities such as construction,
excavation, yard work, and gardening (Hawley, 1985). Site-specific data on soil contact intensity,
including potential seasonal variations, should be considered in evaluating whether or not the default
value is applicable to the population of concern and, if not, activity-weighted estimates of IR S that
more accurately reflect the site can be developed.

In adopting the single IR S parameter to describe all sources of ingested soil, the methodology
remains consistent with recommendations of the Superfund program and their implementation for risk

-------
assessment; specifically, the 0.05 g/day value used for adult soil ingestion addresses all occupational
soil intake by the individual, whether directly from soil or indirectly through contact with dust (U.S.
EPA, 1993). This value specifically applies to the assessment of soil lead risk, and not risks
associated with non-soil sources of lead in dust. In making soil ingestion exposure estimates under the
Risk Assessment Guidelines for Superfund (RAGS) framework, no specific assumptions are needed about the
fraction of soil intake that occurs through dust.

An alternative approach was needed in the IEUBK Model because childhood lead exposures are often
strongly influenced by indoor sources of lead in dust (e.g., indoor paint) (U.S. EPA, 1994b). In a
situation where indoor sources of dust contamination are important, an exposure estimate that addresses
only soil exposures (including the soil component of dust) would be incomplete. The IEUBK Model assigns
separate values to outdoor soil and total indoor dust ingestion and partitions the indoor dust into
soil-derived and non-soil-derived sources. At a minimum, paired soil and indoor dust samples should be
collected to adeguately characterize exposure to lead where indoor sources of dust lead may be
significant.

Alternate method for calculating soil and dust ingestion as separate exposure pathways. In this
alternate approach, separate estimates are made of lead intake from the direct ingestion of outdoor soil
and from the ingestion of indoor dust (which may contain lead from soil and as well as from indoor
sources such as deteriorated lead based paint). Exposure to lead from soil (outdoor contact) can be
calculated using Eguation A-12, while exposure to lead from indoor dust can be calculated using Eguation
A-13.
INTAKE S,outdoors =
PbS D IR S,outdoors D EF Site
AT
(Eguation A-12)
PbD D IR D,indoors D EF Site
INTAKE D,indoors =
AT
(Eguation A-13)
Daily average intake (ingestion) of lead from soil ingested outdoors
(Ig/day).

Daily average intake (ingestion) of lead from dust ingested indoors
(Ig/day).

Soil lead concentration (Ig/g) (average concentration in assessed
individual exposure area) .

Indoor dust lead concentration (Ig/g).

Intake rate (ingestion) of indoor dust (g/day).

Exposure freguency at site (days of exposure during the averaging
period); may be taken as days per year for continuing, long term
exposures.

Averaging time, the total period during which the assessed
exposures (from all sources) occur (days). May be taken as 365
days per year for continuing, long term exposures.

Note that, in Eguations A-12 and A-13, exposure freguency refers to the number of days that an individual
is present at the site and does not partition between periods of indoor and outdoor exposures. The
intake rate is a long term average value appropriate for that media and is influenced by both the
duration of outdoor (or indoor) exposures and the intensity of those exposures.

Calculation of IR S, outdoors and IR D, indoors from total intake of soil and dust (IR S+D).
Intermediary calculations may be needed to generate estimates of the parameters in the intake eguations.
An estimate of the total intake of soil and dust materials (IR S+D) serves as a starting point. Note that
IR S+D differs from IR S, which was discussed above, because IR S+D includes not only the mass of
non-soil derived dust components including various materials of indoor origin. Since a substantial
fraction of the mass of indoor dust comes from sources other than outdoor soils, an estimate of IR S+D
will be higher than the corresponding estimate of IR S. Secondly, an estimate of the fraction the total
soil and dust intake that is ingested directly as soil is needed (Weighting soil). This estimate needs
INTAKE S, outdoors

INTAKE D, indoors

PbS

PbD

IR S, outdoors

IR D, indoors

EF Site

-------
to take into account the intensity and duration of the outdoor soil intake and the indoor dust intake.
Equations A-14 and A-15 can be used to derive media-specific ingestion rates from IR S+D and Weighting
soil.

            IR S,outdoors = Weighting soil D IR S+D                          (Equation A-14)


            IR D,indoors =  (1 - Weighting soil) D IR S+D                     (Equation A-15)

Weighting soil  =  Fraction of total soil and dust intake that is directly ingested as soil
                   (dimensionless).

IR S+D          =  Total daily average intake of outdoor soil and indoor dust  (all dust
                   components) (g/day).

Data are needed to generate separate estimates of the concentrations of lead in outdoor soil and in
indoor dust.  A site assessment using this alternate methodology would generally be based on direct
measurement data for total soil ingestion (the primary approach presented in this paper), Equation A-16
may be utilized to estimate the ratio of dust lead concentration to soil lead concentration.

                   PbD = PbS D K SD                                          (Equation A-16)


K SD  =  Ratio of indoor dust lead concentration to soil lead concentration  (dimensionless).

Assuming that the same absorption fraction is applicable to both soil and dust, Equation A-17 may be used
to estimate the uptake of lead from these two sources.

       UPTAKE = AF S,D D (INTAKE S,outdoors + INTAKE D,indoors)              (Equation A-17)

UPTAKE   =   Daily average uptake of lead from the gastrointestinal tract into the systemic
             circulation; soil and dust sources (Ig/day).

AF S,D   =   Absolute gastrointestinal absorption fraction for ingested lead in soil and dust
              (dimensionless).

       Comparison of lead intake estimated from principal and alternate approaches.   It is
helpful to compare exposure estimates derived using our principal approach based on total soil intake or
soil and dust.  We will consider the case in which there are not important indoor sources of lead in
dust.  We can then compare the total lead intake estimates from the two approaches.

       Under the model based on total soil ingestion (which we re-label as IR S,total for clarity):

                      Pbs D IR S,total DEF Site
            INTAKE =                                                         (Equation A-18)
                                 AT

By contrast, using the disaggregated soil and dust model, Equations A-14, A-15, A-16, and A-18 may be
combined to give Equation A-19:


              PbS D IR S+D D(Weighting soil + K SD D (1 -Weighting soil))DEF Site
     INTAKE =                                                                (Equation A-19)
                                               AT

When applied to the same exposure assessment problem, the two approaches should give equivalent
estimates of lead intake.  The estimates will be equivalent when:


                  IR S+D D  (Weighting soil + K SD D  (1 -Weighting soil)) = IR S,total

8.      Exposure Frequency (EF S)

       The TRW recommends a default value of 219 days/year.   This is the same as  the central tendency
occupational exposure frequency recommended by U.S. EPA  (1993) Superfund guidance, which is based on 1991
data from the Bureau of Labor Statistics.  This estimate corresponds to the average time spent at work by

-------
both full-time and part-time workers engaged in non-contact intensive activities (U.S. EPA, 1993).
Site-specific data on exposure freguency should be considered in evaluating whether or not the default
value is applicable to the population of concern. In evaluating site-specific data, it should be kept in
mind that exposure freguency and daily soil ingestion rate (IR S) may be interdependent variables,
particularly in contact-intensive scenarios; therefore, the assignment of a site-specific value to EF S
should prompt an evaluation of the applicability of the default value for IR S to the population of
concern (see Section 7 of the Appendix for further discussion).

Nonresidential exposure scenarios in which exposure freguency would be substantially less than 219
days/year are freguently encountered. Examples include trespassing and recreational use of a site.
Important methodology constraints on exposure freguency and duration must be considered in assigning
values to EF S that would represent infreguent contact with the site; these constraints relate to the
steady state assumptions that underlie the BKSF. The BKSF derived from the Pocock et al. (1983) data
applies to exposures that result in a guasi-steady state for blood lead concentration; that is, an intake
over a sufficient duration for the blood lead concentration to become nearly constant over time. Based
on estimates of the first order elimination half-time for lead in blood of approximately 30 days for
adults (Rabinowitz, et al., 1974 1976; Chamberlain et., 1978), a constant lead intake rate over a
duration of 90 days would be expected to achieve a blood lead concentration that is sufficiently close
the guasi-steady state. This is the minimum exposure duration to which this methodology should be
applied.

Infreguent exposures (i.e., less than 1 day per week) over a minimum duration of 90 days would be
expected to produce oscillations in blood lead concentrations associated with the absorption and
subseguent clearance of lead from the blood between each exposure event. Based on the above assumptions
about the elimination half-time lead in blood, the TRW recommends that this methodology should not be
applied to scenarios in which EF S is less than 1 day/week.

9. Applying Monte Carlo Analysis to the Adult Lead Methodology

Recent EPA guidance (Browner, 1995) recommends that risk assessments include a clear and
transparent discussion of variability and uncertainty. The lead risk assessment methodology presented
here develops explicit estimates of the variability of blood lead levels among adults who are exposed of
studies (baseline blood lead levels, variability of blood lead levels, contact rates with environmental
media, lead bioavailability, and lead biokinetics) to support a predictive probabilistic (lognormal)
model for adult and fetal blood lead concentrations. Important issues regarding the uncertainty in
parameter inputs and the mathematical form of the model are discussed in the sections of this Appendix.
The TRW recognizes that there is considerable scientific interest in the different analytical approaches
that may be applied to aid in the analysis of variability and uncertainty in risk assessments. In
particular, under appropriate circumstances, Monte Carlo methods may provide a useful approach for
developing guantitative estimates of the variability, uncertainty (or both) in risk predictions.

The TRW chose not to pursue application of Monte Carlo or other stochastic simulation methods in
this effort addressing adult lead risk assessment. Several factors went into this decision. First, the
TRW understood the needs of EPA Regions for a risk model that could be developed relatively rapidly and
which Regional lead risk assessors could apply easily with limited need for additional study or training.
These considerations made it advantageous to focus on models that are conceptually similar to the IEUBK
model for children in terms of applying a parametric lognormal modeling approach to address distributions
for blood lead levels. Secondly, the TRW recognized that there would be substantial scientific issues
associated with developing widely applicable stochastic simulation models for adult lead risk assessment.
These difficulties primarily relate to the absence of reliable distributional data for a variety of
important variables in the assessment. As one example, very limited data are available on soil ingestion
rates in adults and a distributional choice for this key parameter would depend heavily on individual
judgement with little Agency precedent for support. Additionally, in a stochastic assessment, a greater
complexity would arise due to likely correlations among the variables in the adult lead risk assessment.
Stochastic analyses need to explicitly account for important correlations among variables if the
simulations are to provide realistic distributions of risk. As an example, dependence is likely to exist
between the starting (non-site related) blood lead concentrations for individuals and their site-related
increases in blood lead. This dependence may result from individual patterns of behavior and from
biological factors associated with lead pharmacokinetics. However, data on this dependence are sparse or
absent, and the necessary statistical estimates of the correlation strength would depend heavily on
personal judgement.

The TRW does encourage further efforts to better define the distributional data on which
stochastic simulations of lead risks might rest. Further attention to these data can provide useful
insights for lead risk assessment. The TRW also recognizes that Regions may be presented with lead risk
assessments based on Monte Carlo modeling. In order to facilitate review of Monte Carlo analyses, some

-------
EPA Regions have found it important to establish requirements for the orderly development and review of
these assessments.  Borrowing on this approach,  the TRW recommends that:

       •       A plan for the used of Monte Carlo analysis  in a lead risk  assessment  should be submitted to
              responsible Regional personnel  and accepted  by them before  the  Monte Carlo analysis  is
              undertaken.

       •       In general,  it is  expected that site-specific exposure related  parameters  that  are  supported
              with site-specific information  will provide  the basis for proposed Monte Carlo  simulations.

       •       Scientific review  is needed to  determine  that the risk assessment  conformed to  the  plan and
              to evaluate the reliability of  the results.

These recommendations are designed to ensure that assessments can provide meaningful results  that can be
understood and evaluated.  If analyses are submitted in a format that is  difficult to understand,  the
utility of the analysis will be  diminished.  We recommend that Regional staff seek advice from the TRW as
a resource in this process.

-------
                                              10.   References

Alexander. F.W. and H.T. Delves.  1981 Blood lead levels during pregnancy Int. Arch. Occup. Environ.
Health. 48:  35-39.

Baghurst P.A., A.J. McMichael. G.V. Vimpani. E.F. Robertson, P.D. Clark, andN.R. Wigg. 1997.
Determinants of blood lead concentrations of pregnant women living in Port Pirie and surrounding
areas.  Medical J. of Australia.  146:  69-73.

Balbus-Kornfeld, J.  1994.  Comments and Recommendations on the Draft Interim Guidance for Screening
Levels of Lead in Soil for Non-Residential  Sites.  Letters from John Balbus-Kornfeld to Bruce Means.
November 17, 1994.

Barltrop, D. and F. Meek.  1975.  Absorption of different lead compounds.  Postgrad. Med. J. 51: 805-809.

Barltrop, D. and F. Meek.  1979.  Effect of particle size on lead absorption from the gut. Arch. Environ.
Health. 34:  280-285.

Blake, K.C.H.  1976.  Absorption of 203 Pb  from gastrointestinal tract of man.  Environ. Res. 11:   1-4.

Blake, K.C.H. and M. Mann.  1983.  Effect of calcium and phosphorus on the gastrointestinal absorption of
203 Pb in man.  Environ. Res. 30:  188-194.

Blake, K.C.H., G.O. Barbezat and M. Mann.   1983.  Effect of dietary constituents on the gastrointestinal
absorption of 203 Pb in man.  Environ. Res. 30:  182-187.

Bowers, T.S., B.D. Beck and H.S. Karam.  1994.  Assessing the relationship between environmental lead
concentrations and adult blood lead levels.  Risk Analysis.  14(2):  183-189.

Brody, D.J. Personal communication on October 24, 1996 and October 29, 1996.

Brody, D.J., J.L. Pirkle, R.A. Kramer, K.M. Flegal, T.D. Matte, E.W. Gunter and D.C. Paschal. 1994.
Blood lead levels in the U.S. population.   Phase 1 of the third National Health and Nutrition Examination
Survey (NHANES III, 1988 to 1991).  JAMA. 272(4):  277-283.

Browner,  C.M.  1995.  Policy for Risk Characterization at the U.S. EPA.  Memorandum from U.S. EPA
Administrator dated March 21, 1995.

Chamberlain, A.C., M.J. Heard, P. Little, D. Newton, A.C. Wells and R.D. Wiffen.  1978. Investigations
into lead from motor vehicles.  Harwell, United Kingdom:  United Kingdom Atomic Energy Authority, Report
No. AERE-R9198.

Davenport. H.W.  1971.  Gastric digestion and emptying; absorption.  In:  Physiology of the Digestive
Tract, 3rd ed.  Year Book Medical Publishers Inc., Chicago.  pp.  165-168

Franklin, C.A. , M.J. Inskip, C.L. Baccanale, E.J. O'Flaherty, W.I. Manton, D.L. Schanzer, J. Blenkinsop
and C.M.  Edwards.  1995.  Transplacental transfer of lead in non-human primates  (Macaca fascicularis):
use of serially administered stable isotope tracers of lead to elicit contribution of maternal bone lead
to blood lead and the fetus.  Poster presented at the 1995 meeting of the Society of Toxicology,
Baltimore, MD.  The Toxicologist.  15:194.

Gershanik, J.J., G.G. Brooks, and J.A. Little.  1974.  Blood lead values in pregnant women and their
offspring.  Amer. J. Obster. Gynecol. 4:  508-511.

Goyer, R.A. 1990.  Transplacental transport of lead.  Environ. Health Perspect. 89:  101-105.

Graziano, J.H., D. Popovac, P. Factor-Litvak, P. Shrout, J. Kline, M.J. Murphy, Y. Zhao, A. Mehmeti, X.
Ahmedi, B. Rajovic, Z. Zvicer, D. Nenezic, N. Lolacono and Z. Stein.  1990. Determinants of elevated
blood lead during pregnancy in a population surrounding a lead smelter in Kosovo, Yugoslavia.  Environ,
Health Perspect.  89:  95-100.

Graziano, J.H., W.I. Manton, C.B Blum and N.J. Lolacono.  1995.  Bioavailability of lead in wine, by
stable isotope dilution.  Poster presented  at the 1995 meeting of the Society of Toxicology, Baltimore,
MD.  The Toxicologist.  15:  135  (abst).

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Hawley, J.D.  1985.  Assessment of health risk from exposure to contaminated soil. Risk Analysis.
5:289-302.

Heard, M.J. and A.C. Chamberlain.  1982.  Effect fo minerals and food on uptake of lead from the
gastrointestinal tract in humans.  Human Toxicol. 1:  411-415.

Hunt, J.N. and W.R. Spurrell.  1951.  The pattern of emptying of the human stomach.  J. Physiol.
113:  157-168.

James, H.M., M.E. Milburn and J.A. Blair.  1985.  Effects of meals and meal times on uptake of lead from
the gastrointestinal tract of humans. Human Toxicol. 4:  401-407.

Maddaloni, M., W. Manton, C. Blum, N. Lolacono and J. Graziano.  1996.  Bioavailability of soil-borne
lead in adults, by stable isotope dilution.  The Toxocologist. 30:  15  (abst.)

NRC.  1993.  Measuring Lead Exposure in Infants, Children and Other Sensitive Populations. National
Academy Press. Washington, DC.  ISBN 0-309-04927-X.

Pocock, S.J., A.G. Shaper, M. Walker, C.J. Wale, B. Clayton, T. Delves, R.F. Lacey, R.F. Packham and P.
Powell.  1983.  Effects of tap water lead, water hardness, alcohol, and cigarettes on blood lead
concentrations.  J. Epidemiol. Commun. Health.  37:  1-7.

Rabinowitz, M.B., G.W. Wetherill and J.D. Koppel.  1974 Studies of human lead metabolism by use of stable
isotope tracers.  Environ. Health Perspect. 7:  145-153.

Rabinowitz, M.B. G.W. Wetherill and J.D. Koppel.  1976.  Kinetic analysis of lead metabolism in health
humans.  J. Clin. Invest.58:  260-270.

Rabinowitz, M.B. J.D. Koppel and G.W. Wetherill.  1980.  Effect of food intake on fasting
gastrointestinal lead absorption in humans.  Am. J. Clin. Nurt. 33:  1784-1788.

Ruby, M.V., A. Davis, R. Schoof, S. Eberle and C.M. Sellstone.  1996.  Estimation of lead and arsenic
bioavailability using a physiologically based extraction test.  Environ. Sci. Technol. 30:  422-430.

Sherlock,  J., G. Smart, G.I. Forbes, M.R. Moore, W.J. Patterson, W.N. Richards and T.S. Wilson. 1982.
Assessment of lead intakes and dose-response for a population in Ayr exposed to a plumbosolvent water
supply.  Human Toxicol. 1:  115-122.

Sherlock,  J.C., D. Ashby, H.T. Delves, G.I. Forbes, M.R. Moore, W.J. Patterson, S.J. Pocock, M.J. Quinn,
W.N. Richards and T.S. Wilson.  1984.  Reduction in exposure to lead from drinking water and its effect
on blood lead concentrations.  Human Toxicol. 3:  383-392.

Silbergeld, E.K. 1991.  Lead in bone:  Implications for toxicology during pregnancy and lactation.
Environ.   Health Perspect. 91:  63-70.

U.S. EPA.  1986.  Air Quality Criteria for Lead Volumes I - IV.  Environmental Criteria and Assessment
Office, Office of Research and Development, RTP, NC.  EPA 600/8-83-028 a-d.

U.S. EPA.  1989.  Exposure Factors Handbook.  Office of Health and Environmental Assessment, Washington,
DC.  EPA/600/8-89/043.

U.S. EPA.  1990.  Supplement to the 1986 EPA Air Quality Criteria Document for Lead - Volume 1 Addendum.
Office of  Research and Development, Office of Health and Environmental Assessment, Washington, DC.
EPA-600/8-89/049A.

U.S. EPA.  1992.  A TRW Report:  Review of the EPA Uptake Biokinetic Model for Lead at the Butte NPL
Site.  Technical Review Workgroup for Lead, October, 1992.

U.S. EPA.  1993.  Superfund's Standard Default Exposure Factors for the Central Tendency and RME-Draft.
Working Draft, November 1993.

U.S. EPA.  1994a.  Revised Interim Soil Lead Guidance for CERCLA Sites and RCRA Corrective Action
Facilities.  OSWER Directive No. 9355.4-12.  Office of Emergency and Remedial Response, Washington, D.C.
EPA/540/F-94/043, PB94-963282.

-------
U.S.EPA.  1994b.  Technical Support Docuement:  Parameters and Equations Used in the Integrated Exposure
Uptake Biokinetic Model for Lead in Children  (v. 0.99d).  Office of Emergency and
Remedial Response, Washington, D.C. EPA/540/R-94/040, PB94-963505.

U.S. EPA.  1994c.  Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in
Children.  Office of Emergency and Remedial Response.  Washington. D.C.  EPA 540/R-93/081, PB93-963510.

U.S. EPA.  1995.  A TRW Report Review of a Methodology for Establishing Risk-Based Soil Remediation Goals
for the Commercial Areas of the California Gulch Site.  Technical Review Workgroup for Lead, October,
1995.

Weis, C.P., G.M. Henningsen. R.L. Poppenga, B.J. Thacker, A. Curtis, R. Jolly and T. Harpstead.
1994.  Use fo an immature swine model to sensitively differentiate lead absorption from soluble and
mineralogical matrices.  Presented at the Society for Environmental Geochemistry and Health, Salt Lake
City, UT, July 18-19, 1994.

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ATTACHMENT 3 - DESCRIPTIONS OF ORIGINAL 18 ALTERNATIVES

TABLE 5.1-3
DEFINITION OF CANDIDATE ALTERNATIVES

ALTERNATIVE DESCRIPTION

SOURCE MATERLALS -
No Action.

ALTERNATIVE 1 GROUND WATER -
No Action.

SURFACE WATER -
No Action.

SOURCE MATERIALS -
Mill wastes in yards of existing residences confirmed to be built on former mill waste piles
would be remediated by excavation and removal and/or on-site containment methods.
Institutional controls would be implemented to prevent future residential development on
mill waste areas without first remediating the homesites.
ALTERNATIVE 2
GROUND WATER -
Ground-water RAO No. 1 would be addressed by eliminating or reducing metal loadings
from the Bruger shafts by reducing surface recharge to the Bruger workings, passive in-
mine biological treatment, or collection and storage of Bruger discharges. RAO No. 2
would be met by not diverting surface-water flows or placing mill wastes into mine
workings in hydraulic connection with workings in the Tar Creek Superfund Site. Current
and future residences would be reguired to be connected to existing treated water supplies
through institutional controls prohibiting the domestic use of shallow ground water (RAO
No. 3). A search for abandoned deep bore holes and wells would be made and those
located would be plugged. Strict design standards for the construction of new wells would
be instituted for future, protection of the deep aguifer (RAO No. 4).

SURFACE WATER -
No action is reguired to address RAO No. 1 since no ARARs exceedances in the Spring and
Neosho Rivers were attributable to subsite sources. RAO No. 2 would be addressed in
Willow Creek through reduction of metal loadings from the Bruger shafts. Enforcement of
existing federal and/or state water guality regulations at currently operating facilities may
also reduce metal loadings in subsite streams.

SOURCE MATERIALS -
Mill Wastes in yards of existing residences confirmed to be built on former mill waste piles
would be remediated by excavation and removal and/or on-site containment methods.
Institutional controls would be implemented to prevent future residential development on
mill waste areas exceeding 600 mg/kg lead, 23,464 mg/kg zinc, and/or 120 mg/kg
cadmium, without first remediating the homesites.

GROUND WATER -
ALTERNATIVE 3 Same as Alternative 2.

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SURFACE WATER -
No action is required to address RAO No. 1. RAO No. 2 would be addressed in Willow
Creek through reduction of metal loadings from the Bruger shafts. Additionally, RAO No.
2 would be addressed through removal and on-site disposal of all outwash tailings in both
subsites. Appropriate source containment, drainage, and erosion control actions would be
implemented to prevent the future release of tailings to subsite streams. The excavated
outwash tailings would be placed in tailings impoundments which would then be capped in
place with soil/clay cover systems to prevent future releases.

SOURCE MATERIALS -
Same as Alternative 2.

GROUND WATER -
Same as Alternative 2.
ALTERNATIVE 4a
SURFACE WATER -
No action is required to address RAO No. 1. RAO No. 2 would be addressed in Willow
Creek by controlling metal loadings from the Bruger shafts and through containment actions
performed on the largest zinc loading sources in both the Spring Branch and Tar Creek
drainages. Outwash tailings deposits deemed to rank among the largest metal loading
sources would be excavated, removed, and disposed of in the mill waste areas to be
remediated. Drainage/erosion control actions would also be implemented to augment the
containment actions, as appropriate.

SOURCE MATERIALS -
Same as Alternative 2.

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TABIiE 5.1-3 (CONTINUED)
DEFINITION OF CANDIDATE ALTERNATIVES

ALTERNATIVE DESCRIPTION

GROUND WATER -
Same as Alternative 2.
ALTERNATIVE 4b
SURFACE WATER -
No action is required to address RAO No. 1. RAO No. 2 would be addressed by
controlling metal loadings from the Bruger shafts in Willow Creek and through source
removal and on-site disposal actions performed on the largest zinc and cadmium loading
sources in both the Spring Branch and Tar Creek drainages, including some outwash tailings
deposits. Excavated mill wastes would be disposed of in surface mine openings within the
subsites determined not to be connected to the workings in the Tar Creek Superfund Site.
Drainage/erosion control actions would also be implemented, as appropriate.

SOURCE MATERIALS -
Same as Alternative 2.

GROUND WATER -
ALTERNATIVE 5a Same as Alternative 2.

SURFACE WATER -
No action is required to address RAO No. 1. RAO No. 2 would be addressed through
containment actions performed on all significant zinc and cadmium loading sources in both
the Spring Branch and Tar Creek drainages. Some removal and drainage/erosion control
actions would also be implemented to augment the containment actions. Metal loadings to
Willow Creek from the Bruger shafts would be controlled.

SOURCE MATERIALS -
Same as Alternative 2.

GROUND WATER -
Same as Alternative 2.

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TABIiE 5.1-3 (CONTINUED)
DEFINITION OF CANDIDATE ALTERNATIVES

ALTERNATIVE DESCRIPTION
ALTERNATIVE 5b
SURFACE WATER -
No action is required to address RAO No. 1. RAO No. 2 would be addressed through
excavation and on-site disposal of significant zinc and cadmium loading sources in both the
Spring Branch and Tar Creek Drainages. Excavated materials would be placed in mine
openings and/or on-site repositories for disposal. Removal actions would be confined to the
immediate areas around streams and ponds. Source removal actions would be augmented by
drainage/erosion actions. Metal loadings to Willow Creek from the Bruger shafts would
also be controlled.

SOURCE MATERIALS -
Same as Alternative 2.

GROUND WATER -
ALTERNATIVE 5c Same as Alternative 2.

SURFACE WATER -
No action is required to address RAO No. 1. RAO No. 2 would be addressed through
surface-water treatment in the form of conventional metals precipitation in addition to the
same source containment, removal, and drainage/erosion controls prescribed under
Alternative 5a. Centralized surface-water treatment plants would be located in both the
Spring Branch and Tar Creek drainages. Other actions would include construction of
collection and detention basins for flow equalization. Water treatment sludges would be
disposed of in accordance with action-specific ARARs, depending on their chemical
characteristics. Metal loadings to Willow Creek from the Bruger shafts would also be
controlled.

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                                                     TABIiE 5.1-3 (CONTINUED)
                                              DEFINITION OF CANDIDATE ALTERNATIVES

                                        ALTERNATIVE DESCRIPTION

               SOURCE MATERIALS -
                    Same as Alternative 2.

               GROUND WATER -
ALTERNATIVE 5d      Same as Alternative 2.

               SURFACE WATER -
                    The same surface-water actions would be implemented as in Alternative 5c except that
                    passive biological treatment, instead of conventional chemical precipitation, would be
                    performed through construction of passive wetland treatment systems in both the Spring
                    Branch and Tar Creek drainages for the purpose of reducing zinc and associated cadmium
                    concentrations.  Metal loadings to Willow Creek from the Bruger shafts would be
                    controlled.

               SOURCE MATERIALS -
                    To address RAO No. 1, mill wastes in the yards of existing residences confirmed to be built
                    on former mill waste piles would be remediated by excavation and removal and/or on-site
                    containment methods.  Institutional controls would not be implemented to prevent future
ALTERNATIVE 6a      residential development on mill waste sites or raise garden produce on mill wastes.  Instead,
                    all mill waste piles exceeding 1,000 mg/kg lead, 23,464 mg/kg zinc, and/or 120 mg/kg
                    cadmium, except for large volume chat piles, would be remediated by capping in place with
                    vegetated soil and soil/clay cover systems designed to protect possible future residents from
                    direct exposures to metals in the wastes.  Large volume chat piles would be considered
                    potential future resources and would remain unremediated.

               GROUND WATER -
                    Same as Alternative 2 except that institutional controls to prevent future consumption of
                    shallow ground water would not be implemented.

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TABIiE 5.1-3 (CONTINUED)
DEFINITION OF CANDIDATE ALTERNATIVES

ALTERNATIVE DESCRIPTION

SURFACE WATER -
No action is required to address RAO No. 1. RAO No. 2 would be addressed in Willow
Creek through reduction of metal loadings from the Bruger shafts. Additionally, RAO No.
2 would be addressed through removal and on-site disposal of all outwash tailings in both
subsites. Appropriate drainage and erosion controls would be implemented to prevent the
future release of tailings to subsite streams. The excavated outwash tailings would be
placed in the tailings impoundments to be remediated under the source materials actions
prior to capping.

SOURCE MATERIALS -
Same as Alternative 6A except that mill waste piles, other than large volume chat piles,
exceeding 1,000 mg/kg lead, 23,464 mg/kg zinc, and/or 120 mg/kg cadmium would be
remediated by excavation and on-site disposal in surface mine openings determined not to be
ALTERNATIVE 6b connected to workings in the Tar Creek Superfund Site.

GROUND WATER -
Same as Alternative 6A.

SURFACE WATER -
Same as Alternative 6A except that the excavated outwash tailings and their sources would
be placed in surface mine openings determined not to be connected to workings in the Tar
Creek Superfund Site.

SOURCE MATERIALS -
Same as Alternative 6B except that mill waste piles, other than large volume chat piles,
exceeding 1,000 mg/kg lead, 23,464 mg/kg zinc, and/or 120 mg/kg cadmium would be
remediated by excavation and on-site disposal in engineered waste repositories located in
ALTERNATIVE 6c each subsite.

GROUND WATER -
Same as Alternative 6A.

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TABIiE 5.1-3 (CONTINUED)
DEFINITION OF CANDIDATE ALTERNATIVES

ALTERNATIVE DESCRIPTION

SURFACE WATER -
Same as Alternative 6B except that the excavated outwash tailings and their sources would
be excavated and placed in engineered repositories located in each subsite.

SOURCE MATERIALS -
To address RAO No. 1. mill wastes in yards of existing residences confirmed to be built on
former mill waste piles would be remediated by excavation and removal and/or on-site
containment methods. Institutional controls would not be implemented to prevent future
ALTERNATIVE 7a residential development on mill waste sites. Instead, all mill waste except for large volume
chat piles, would be remediated by capping in place with vegetated soil and soil/clay cover
systems designed to protect possible future residents from direct human exposures to metals
in the wastes. Large volume chat piles would be considered a potential future resource and
remain unremediated.

GROUND WATER -
Same as Alternative 2 except that institutional controls to prevent future consumption of
shallow ground water would not be implemented.

SURFACE WATER -
No action is reguired to address RAO No. 1. RAO No. 2 would be addressed in Willow
Creek through reduction of metal loadings from the Bruger shafts. Additionally, RAO NO.
2 would be addressed through removal and on-site disposal of all outwash tailings in both
subsites. Appropriate drainage and erosion controls would be implemented to prevent the
future release of tailings to subsite streams. The excavated outwash tailings would be
placed in the tailings impoundments to be remediated under the source materials actions
prior to capping.

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                                                     TABIiE 5.1-3 (CONTINUED)
                                              DEFINITION OF CANDIDATE ALTERNATIVES

                                        ALTERNATIVE DESCRIPTION


               SOURCE MATERIALS -
                    Same as Alternative 7A except that mill wastes, other than large volume chat piles, would
                    be remediated by excavation and on-site disposal in surface mine openings determined not to
                    be connected to workings in the Tar Creek Superfund Site and/or placed in an on-site
ALTERNATIVE 7b      repository.

               GROUND WATER -
                    Same as Alternative 7A.

               SURFACE WATER -
                    Same as Alternative 7A except that the excavated outwash tailings would be placed in
                    surface mine openings determined not to be connected to working in the Tar Creek
                    Superfund Site.

               SOURCE MATERIALS -
                    Same as Alternative 7B except that mill wastes, other than large volume chat piles, would
                    be remediated by excavation and on-site, disposal in engineered waste repositories located in
                    each subsite.
ALTERNATIVE 7c
               GROUND WATER -
                    Same as Alternative 7A.

               SURFACE WATER -
                    Same as Alternative 7A except that the excavated outwash tailings would be placed in
                    engineered waste repositories in each subsite.

-------
TABIiE 5.1-3 (CONTINUED)
DEFINITION OF CANDIDATE ALTERNATIVES

ALTERNATIVE DESCRIPTION

SOURCE MATERIALS -
The source materials RAOs would be addressed through complete removal and on-site
disposal of all source materials in both subsites. This alternative assumes wastes would be
placed in on-site engineered repositories located in both subsites. Institutional controls
ALTERNATIVE 8a would not be implemented except to prevent future disturbance of the on-site disposal areas.

GROUND WATER -
Same as Alternative 2.

SURFACE WATER -
Surface water RAOs would be addressed through the excavation, removal, and on-site
disposal of all source materials in the Spring Branch and Tar Creek drainages, as described
under source materials actions, above. Metal loadings to Willow Creek from the Bruger
shafts would be controlled.

SOURCE MATERIALS -
The source materials RAO would be addressed through the same actions prescribed in
Alternative 8a except that all usable chat would be processed for recovery and sale of
aggregate values. Chat processing is expected to reduce the volume of materials to be
disposed of by approximately 2.4 million cubic yards. The remaining mill wastes would be
placed in engineered repositories, as proposed for Alternative 8A. Other actions could
ALTERNATIVE 8b include segregation of excavated materials according to particle size and metals
concentrations, and capping of filled mine shafts and subsidence pits.

GROUND WATER -
Same as Alternative 2.

SURFACE WATER -
Same as Alternative 8a.

-------
                                                     TABIiE 5.1-3  (CONTINUED)
                                              DEFINITION OF  CANDIDATE ALTERNATIVES

                                        ALTERNATIVE DESCRIPTION
               SOURCE MATERIALS -
                    Same as Alternative 8A except that all excavated chat areas would be remediated by
                    regrading, placing 12 inches of clean soil over the surfaces of the piles, and revegetating  to
                    protect potential future residents from ingestion of metals.   Institutional  controls would not
                    be implemented except to prevent future disturbance of the on-site disposal  areas.
ALTERATIVE 8c GROUND WATER -
                    Same as Alternative 2.
               SURFACE WATER -
                    Surface water RAOs would be addressed through the excavation, removal, and on-site
                    disposal of all tailings and chat in the Spring Branch and Tar Creek drainages,  as described
                    under source materials actions, above.  Metal loadings to Willow Creek from  the  Bruger
                    shafts would be controlled.

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                             ATTACHMENT 4 - TECHNICAL IMPRACTICABILITY WAIVER

                                               Attachment #4
                             Additional Technical Impracticability Information
Purpose
       This technical impracticability TI,  attachment to the Record of Decision ROD,  for the Baxter
Springs and Treece subsites, operable units #03 and #04 (OU-3/4), of the Cherokee County, Kansas site is
provided for additional clarification of the TI aspects of the selected remedy.  This information
compliments sections and 11.0 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.

       The TI justification for this action is based on the fact that legally applicable or relevant and
appropriate reguirements (ARARs) compliance would be inordinately costly from an engineering perspective.
Chemical-specific ARARs under the Clean Water Act  (CWA) regulating surface water guality and the Safe
Drinking Water Act (SDWA) regulating groundwater drinking water will not be met by the selected remedy
due to technical impracticability based on an inordinately costly determination.

Background

       The Baxter Springs and Treece subsites collectively encompass approximately 28 sguare miles or
nearly 18,000 acres and contain an estimated 4.3 million cubic yards of mining wastes.  These subsites
are a small component of the larger Cherokee County Superfund site  (115 sguare miles).  The Cherokee
County 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.

       Three Environmental Protection Agency (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.

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           ATTACHMENT 5 - FINANCIAL FUND  INFORMATION
              Appendix C to  the Feasibility  Study

 Addendum to Evaluate the Types and  Potential Effectiveness  of

Institutional  Controls at the Baxter-Springs  and Treece Subsites

                          Prepared for

         United States Environmental  Protection Agency
                           Region VII
                      Kansas City, Kansas

                          on behalf of

                 Cherokee County Superfund Site
                Potentially  Responsible Parties
                               by
         Bayh, Connaughton,  Fensterheim  & Malone,  P.C.
            1350  Pennsylvania Avenue,  N.W.  Suite 200
                     Washington,  B.C.  20005
                          May 13,  1993

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I.      Introduction

The Feasibility Study for the Baxter Springs and Treece subsites discusses in several of the remedial
alternatives the use of "institutional controls," i.e. non-engineering access restrictions, at the
subsites to restrict the likelihood of human exposure to hazardous substances and thereby reduce
potential future risks to human health at the subsites.  Like any remedial alternative,  the evaluation
and potential selection of institutional controls, whether as the sole remedial alternative or in tandem
with engineering and treatment technologies, must be undertaken in accordance with the provisions of the
National Contingency Plan (NCP),  40 CFR Part 300, which reguire a thorough analysis of any remedial
alternative in accordance with nine decisionmaking factors.  Use of these nine criteria allow for an
objective comparison of remedial alternatives as to their overall effectiveness in meeting the statutory
reguirements of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA).

Since CERCLA was enacted in 1980, the use of institutional controls at CERCLA sites as a means of
protecting human health has undergone considerable study by EPA and interested parties,  and such controls
have been used successfully at a growing number of sites. CERCLA Section 121 indicates a preference for
remedial actions that rely upon the treatment of hazardous substances to meet applicable and relevant or
appropriate reguirements (ARARs)  on a permanent basis.  However, experience with the CERCLA program
indicates that the treatment of high volume, low toxic materials, such as many mining wastes,  may not be
cost-effective when viewed in light of the risk the materials may pose to human health and the likelihood
that persons will be exposed to the materials.  In addition,  the preparation of a risk assessment,  as
part of the remedial investigation and feasibility study  (RI/FS) process, provides site-specific
information that is very useful in tailoring institutional controls,  as part of the remedy selection
process, to achieve a meaningful reduction of the specific site risks to human health.  This can make the
entire process more efficient and less costly.

Institutional controls also offer a potential means for preventing future human exposure scenarios that
may be unlikely, but nonetheless must be considered by the Agency to meet its statutory responsibilities.
CERCLA, unlike other environmental programs, does not contain the type of time limitations, such as in
the Resource Conservation and Recovery Act's  (RCRA) hazardous waste management program,  which employs a
30 year post-closure exposure scenario.  Therefore, under CERCLA, materials that may remain at a site are
assumed to pose a risk to human health many years into the future, even if certain remedial measures,
such as containment, are chosen,  since there is a mathematical likelihood that even these precautions can
be undone by natural and human intervention.  Institutional controls offer a means of controlling such
potential exposures. I/

       This addendum discusses the legal authority available  to utilize institutional controls under the
NCP, the types of institutional controls that may be effective in addressing potential risks to human
health at the Baxter-Springs and Treece subsites using the nine selection criteria in the NCP, and the
means for using one or more institutional controls to protect human health at the subsites in a reliable
and efficient manner.  Institutional controls appear to offer EPA with constructive approaches for
reducing the risks to human health at the subsites, and should be given careful consideration in the
remedy selection process.

II.    Institutional Controls Under the National Contingency  Plan

Institutional controls are generally considered to be non-engineenng measures which restrict exposure or
access to hazardous substances or pollutants and contaminants left at a CERCLA site.  They can be as
varied as physical barriers, such as fencing, warning signs,  or surveillance systems manned by security
personnel, or enforceable legal limitations, such as deed restrictions, contracts, zoning provisions, or
ordinances that proscribe certain conduct with regard to the  use of land.
       I/  As is discussed later,  the NCP reguires a review of a remedial action every five years if
       hazardous substances remain at the site.   This offers EPA flexibility in using institutional
       controls, because the Agency will be continuing to monitor the site.

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Although the NCP clearly indicates a selection preference for remedial actions which involve treatment to
achieve a permanent cleanup of a site, the NCP also discusses instances in which institutional controls
have a key role to play at sites:

EPA agrees that institutional controls should not substitute for more
active response measures that actually reduce, minimize, or eliminate
contamination unless such measures are not practicable, as determined
by the remedy selection criteria .... EPA believes, however, that
institutional controls have a valid role under CERCLA (e.g. section
121(d)(2)(B)(ii) appears to contemplate such controls). Institutional
controls are a necessary supplement when some waste is left in place,
as it is in most response actions. Also, in some circumstances where
the balancing of trade-offs among alternatives during the selection of
remedy process indicates no practicable way to actively remediate a
site, institutional controls such as deed restrictions or well-drilling
prohibitions are the only means available to provide protection of public
health.

55 Fed. Reg. 8706, cols. 2-3 (March 8, 1990)(emphasis added).

Where institutional controls are the sole remedy at a site, special precautions must be taken to ensure
that the controls will be reliable. Id. This would include assurances from state and local governments
that the controls are legally enforceable both during and after the completion of operation and
maintenance activities. Other factual demonstrations may be reguired by the Agency to show the
permanence and reliability of specific institutional controls.

The NCP preamble indicates that the decision to use institutional controls is not based upon a single set
of factors: "EPA believes that the discussion of an expectation concerning institutional controls in the
rule is the appropriate level of detail for guidance in the NCP." Id. at 8707, col 1. Instead, the
decision is characterized by flexibility and weighing of site-specific factors.

Mining sites are one of the largest subsets of the sites on the National Priorities List at which
institutional controls have played a significant role. Congress and EPA have noted both in RCRA and
CERCLA that mining wastes, as a category, may differ from other types of industrial materials in the:
(1) hazards they pose to human health and the environment, (2) guantity and location, and (3)
availability of cost-effective treatment methods. In light of these factors, institutional controls have
been remedial candidates for use either to complement other remedial actions, such as removal and/or
containment, or to restrict access to certain areas at which mining wastes are located. The selection of
institutional controls has been demonstrated to be appropriate because risks can be shown to be reduced
and implementation of the controls is cost-effective and reliable at the sites.

In a paper prepared for the Hazardous Waste Management Division, EPA Region VIII, the use of
institutional controls at over twenty different mining sites is critically discussed as to the strengths
and weaknesses of institutional controls. 2/ Another excellent discussion of the use of institutional
controls at mining and other sites is contained in the Feasibility Study for the Whitewood Creek, South
Dakota, Superfund Site and Appendix D (and attachments) to the FS, December 8, 1989. A number of
institutional controls are discussed in this submission, including deed restrictions, both private and
public (see Tab 7, Consent Decree in U.S v Seymour Recycling), and state and local ordinances designed to
limit the drilling or use of potentially contaminated groundwater.

In summary, the NCP allows the use of institutional controls at CERCLA sites, provided the reguirements
of reliability and enforceability can be met. The types of institutional controls and the specific
manner in which any controls are screened and selected are broadly and flexibly addressed in the NCP.
Finally, institutional controls are currently being used at a number of CERCLA sites, particularly mining
sites. Accordingly, it is appropriate to consider the use of institutional controls at the
Baxter-Springs and Treece subsites.
2/ See Sikkema, E., "The Utilization of Institutional Controls at Superfund Sites in
Region VIII of the United States Environmental Protection Agency," report prepared
for Hazardous Waste Management Division, U.S. EPA Region VIII, Denver,
September 24, 1991.

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III.   Use of the Nine NCP Selection Criteria

In conducting a detailed analysis of any remedial alternative, the NCP requires that each alternative be
evaluated with respect to nine criteria:

       (1)     Overall protection of human health and the environment:
       (2)     Compliance with ARARs;
       (3)     Use of treatment to achieve a reduction in the toxicity,  mobility,  or volume of
              contaminants;
       (4)     Long-term effectiveness and permanence in protecting human health and the environment;
       (5)     Short-term effectiveness in protecting human health and the environment;
       (6)     Implementability;
       (7)     Cost;
       (8)     State  acceptance;
       (9)     Community acceptance.

The first two of these nine are unconditional requirements  (unless an ARAR is waived),  while the other
seven are balancing criteria.

In applying the selection criteria to institutional controls, though, certain considerations are evident.
First, institutional controls, by their very nature, do not usually involve treatment of wastes, although
certain institutional controls may require a landowner or land developer to take particular actions to
ensure that unacceptable exposure to hazardous substances are avoided.  This could involve treatment, but
may also allow for other alternatives, e.g., containment.  Second, by focusing on exposure, rather than
the intrinsic toxicity of contaminants, institutional controls may not always result in meeting numerical
standards that are embodied in potential human-health ARARs, such as the maximum contaminant levels
(MCLs) and MCL goals  (MCLGs) under the Safe Drinking Water Act, the Water Quality Criteria of the Clean
Water Act,  or other similar numerical standards.  However, institutional controls may act like
action-specific ARARs, whereby the controls will result in levels of protection that would achieve the
same degree  (or even greater) of risk reduction than that which would be achieved using a numerical ARAR.

It is difficult for purposes of the RI/FS process, which merely identifies potentially relevant
ARARs, to specify whether a particular institutional control would meet ARARs at a site. Accordingly,
discussion of this criteria during the evaluation of various institutional controls, will be general and
provide potential options which would be open to the agency in selecting a remedial action and preparing
a Record of Decision  (ROD).

IV.    Institutional Control Alternatives for the Baxter-Springs and Treece Subsites

As discussed above,  institutional controls can fall into a variety of categories and constitute many
types of access or use limitations.  For purposes of this addendum, two broad groupings of institutional
controls are noted:    (1) proprietary or privately enforceable controls, and (2) governmental controls,
whose adoption and enforcement principally resides in a public body.

Institutional controls at the Baxter-Springs and Treece subsites have been identified in the Feasibility
Study as useful in dealing with potential risks to human health from exposures to mine waste materials
containing heavy metals.  Although certain institutional controls may have applicability to potential
environmental risks, at these subsites there are no institutional controls that would substantially or
effectively address the potential environmental risks.  3/ Therefore, this addendum will focus on
institutional controls as they relate to human health risks.

The RI/FS for the subsites has identified two potentially significant risks to human health arising from
exposure to mine wastes and contaminated groundwater.  The first is the possibility that persons could
locate residences on mine wastes and children at these residences could come into extended contact with
heavy metals, principally lead compounds. EPA models suggest that contact with such mining wastes,
principally through ingestion, could result in predicted blood lead levels in these children exceeding
       3/ It is possible that certain types of institutional controls may address environmental risks.
       For example,  land use controls to prevent run-off into surface waters may limit harmful exposures
       to aquatic life at some sites.  Fencing or other physical barriers could limit trespass by some
       animals, but many other animals could easily overcome such barriers by air,  water, tunneling or
       sheer physical force.  Nonetheless, use of institutional controls to restrict potentially harmful
       environmental exposures should not be ignored,  but instead evaluated on a site-specific basis.

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the 10 ug/dL lead standard adopted by the Centers for Disease Control (CDC). Current indications are
that there are two residences that may be located on mine waste material, although it is not known
whether there are any children at these locations and whether the materials have been remediated such
that heavy metal exposures are controlled. For purposes of this addendum, it is assumed that these two
residences will be actively remediated to eliminate any current risks to human health. Therefore, the
only risks to human health associated with mine waste contamination are of a "potential" nature, based
upon "future use" concerns.

The second potential human health risk at the subsites is associated with the possible consumption of
groundwater from the shallow aguifer. Sampling of the shallow aguifer indicates that in certain
locations, the concentration of heavy metals exceed national drinking water standards (MCLs). Whether
this contamination is due to former mining activity or is from the natural mineralization of the resident
limestones, or both, the restoration of this aguifer is highly impractical from both a technical and a
cost perspective. Residents in the subsites have not historically relied upon the shallow aguifer as a
source of water, but instead have supported the development of local water districts which tap the deeper
aguifer to provide an ample supply of guality water. Nonetheless, there are no existing legal
limitations on the use of the shallow aguifer, and even though the water is not currently being used,
there is a chance in the future that a homeowner or resident in the subsites could use the shallow
aguifer as a source of drinking water and thereby, be exposed to a risk of health effects.

Accordingly, this addendum evaluates various types of institutional controls that could be employed to
limit or manage locating new residences on unremediated mine waste materials and the use of the shallow
aguifer as a source of drinking water by residents in the subsites and discusses the potential
effectiveness of each control in light of the nine EPA selection criteria and other site-specific
information.

A. Consideration of Local Rather State Institutional Controls

In identifying the potential candidate institutional controls, this addendum relies almost exclusively on
controls that are localized to Cherokee County and the Baxter-Springs and Treece areas. In focusing the
addendum on these types of controls, it should be noted that there was an evaluation of the utility of
using Kansas state law in controlling residential development in areas of mine waste and use of the
shallow aguifer. Unfortunately, a review of state law indicated there were no existing legal authorities
that would be applicable to prevent a landowner from locating a residence on mine waste materials or
using the contaminated shallow aguifer as a source of drinking water. Accordingly, either the Kansas
legislature or the Department of Environmental Regulation would have to take action to adopt new
provisions to control this type of land use.

For example, Kansas' Solid and Hazardous Waste Act, K.S.A. Section 65-3401 et seg. does not address
residential and commercial development on contaminated land, except to the extent that the area was an
active waste management facility. Indeed, the permits issued under this authority are generally for
permission to operate a solid or hazardous waste management or disposal area.

K.A.R. Section 28-29-20 imposes a reguirement that before a permit may be issued or renewed for a solid
waste disposal area, when wastes will remain at the disposal area after closure, the secretary may
reguire the execution and filing with the county registrar of deeds, a restrictive covenant to run with
the land that specifies acceptable land uses and reguires maintenance of any waste containment systems.
These are to be permanent restrictions unless extinguished by agreement between the secretary and the
land owner. However, these restrictions are not expected to be applicable to most of the mined materials
remaining in Cherokee County.

The State of Kansas also has the Ground Water Exploration and Protection Act, K.S.A. Section 82a-1201 et
seg. which provides for the exploration and protection of groundwater through licensing and regulation
of water well contractors and to protect groundwater resources from waste and potential pollution by
reguiring plugging and other reguirements. Although the Act has some relationship to the concerns in
Cherokee County of the use of the shallow aguifer for drinking water purposes, the Act does not
necessarily apply to a person constructing a well on his own land for domestic purposes.

Although there are other provisions of state law and regulation that potentially address the types of
future risk factors identified at the two subsites, none of these provisions appeared to provide current
legal authority. The laws and regulations could be amended or new laws and regulations adopted, but it
does not appear to be likely that the problems of one County would result in a significant change in
state law, especially when there are local approaches that may be available and could be focused on the
specific risk-related concerns. Accordingly, this addendum deals primarily with the use of institutional
control on a local level rather than a statewide basis.

B. Evaluation of Specific Institutional Control Alternatives

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Alternative 1 - Agreements Affecting Real Properly Interests

              a.    Description

Real property interests in land include deed restrictions, easements, land development rights and
ownership, and a variety of covenants or land restrictions.  All of these provisions attempt to limit
certain types of land uses in a manner that continue into the future or "run with the land."  In this
regard, the limitation continues to remain in effect even if the property is transferred to other owners.

Land use restrictions could entail agreements which would be negotiated among PRPs and current landowners
to affect the title of any parcels of land at which mine wastes are found or which are underlain by
potentially contaminated groundwater in the shallow aguifer. Restrictions could be imposed upon the land
by the purchase of certain property rights, including fee simple title to the property or development
rights, to control the right to construct dwellings or to undertake commercial development without
remediation of the mine waste or connection to a public water system.

              b.      Discussion

For years, the mineral rights associated with property in Cherokee County have been sold to private
interests.  The sale of certain property rights or the entry of restrictions on the title of real
property is, therefore, not novel.  There do not appear to be any legal impediments under Kansas law for
the sale of such rights to private parties.

However, obtaining the consent of all land owners may be difficult and expensive, unless there is some
State or local power to compel cooperation.  Cherokee County and the State of Kansas have condemnation
(eminent domain)  authority, but it is not clear whether it could or needs to be used to reguire private
acceptance of such property limitations.  Moreover, without governmental support, the existence of a
"captive marketplace" would tend to bid up prices for even less than ownership rights.  At a minimum,
each parcel would tend to value imposition of a price limitation at the same cost as costs of site
remediation and connection to a public water system.  Any economies of scale realized in a broader
remedial action would be lost.

       C.      Relationship to the Selection Criteria

              (1)     Overall  protection of  human health and the  environment;

Assuming land use limitations are met, location of new residences on unremediated mine waste and use of
shallow aguifer as a drinking water source would be precluded.  Human health would be protected.

              (2)     Compliance with ARARs;

Health risks would be brought within acceptable EPA ranges by precluding residential use of areas
contaminated by mine waste or underlain by the contaminated shallow aguifer. Alternatively, a party could
remove chat and/or cover chat to remove health risk, connect to a public water system or alternate
uncontaminated water supply,  and therefore, be able to build residence at the property.

              (3)     Use  of treatment  to achieve a  reduction in  the  toxicity,  mobility,  or volume  of
                     contaminants;

Treatment of any variety is unlikely.   Instead, removal or containment of wastes may occur at some
locations.  Shallow aguifer groundwater would also not be treated.

              (4)     Long-term effectiveness  and permanence in protecting human health and the
                     envi ronment;

Restrictions would continue to appear on the property title unless removed by court order.  A key
guestion is whether over a period of time that the restrictions would be ignored by banks, real estate
brokers, or purchasers and therefore,  would not be enforced.  This is not very likely, though,  and the
failure to heed such limitations would be enforceable in a court by private citizens, the County or the
State.

              (5)     Short-term effectiveness  in protecting human health and the environment;

Land use restrictions should be effective in the short-term, since new residences are not currently being
constructed in areas where mine waste is located.  Affected parcels of land can easily be identified and
the development of a deed restriction should not be complex.

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(6) Implementability;

If implemented by private agreements, the principal problem would be reaching an agreement with all land
owners in the affected areas. Experience with access agreements suggests there will be recalcitrant
property owners. Determining a fair market value may also be difficult.

To ensure uniform compliance. Cherokee County may have to pass some kind of legislation mandating the
inclusion of these provisions on deeds. This could raise the issue of a "takings" if no compensation is
provided to land owners. 4/ The county may also want to obtain an opinion from the Kansas Attorney
General to ensure it has the reguisite legal authority to impose such reguirements and to identify
appropriate legal procedures for enactment of the provisions. 5/

Enforcing these restrictions generally reguires resort to the judicial system, thereby raising their
costs and creating delays. The restrictions do continue apply even if land is transferred to new
parties, but any cloud on the title to land can be a practical problem for a land owner. For example,
refinancing of the property, even if it were for non-residential development, may be complicated by the
existence of a covenant, deed restriction, or land use right revision. This could work a hardship in an
area that is largely comprised of small farms, which may have to borrow against the value of the land to
finance yearly operations.

In addition, if lands are remediated and a landowner could show both that soils met acceptable metals'
standards and there was access to potable water, the landowner may still have to go to court to remove,
e.g. a deed restriction or to have a covenant deemed satisfied. This would add to the cost and the
inconvenience of the transaction and tend to less public acceptance of such a remedy.

(7) Cost;

For a majority of parcels, the cost should not be too great given the current low price of land in
Cherokee County and the lack of significant property development. Recalcitrant land owners will be a
problem and could raise costs. Costs would be much lower if County were in some fashion to intervene and
establish a fair, uniform price.

(8) State acceptance;

There seems to be no reason for state to oppose the approach, except to the degree that County could be
deemed to have exceeded its legal authority in adopting such restrictions.

(9) Community acceptance.

Given the substantial economic reliance on the land for agriculture and other purposes, land use
restrictions may meet with some opposition. Even if revisions of rights were fairly compensated for,
recalcitrant owners would be expected to refuse to cooperate; this has been the experience in trying to
obtain site access. If the opposition was sufficiently great, support from the County would be unlikely.
The wording of any restrictions to discuss mine wastes rather than "hazardous substances," may help limit
certain concerns with using the land as collateral for non-residential loans.
4/ See Lucas v. South Carolina Coastal Council, U.S. , 112 S. Ct. 2886, 120
L. Ed. 2d 798, 34 ERG 1897 (1992). In Lucas the owner of the property was called
upon to sacrifice all economically beneficial use of his property in the "name of
The common good" without compensation. In this instance, the property would be
encumbered only as to certain residential uses and even these encumbrances could be
eliminated upon undertaking certain actions.

5/ Specifically, the County may want guidance regarding whether such a deed restriction
or reguirement constituted in some manner or other a condemnation of land or more likely,
would be a legitimate exercise of the County's home rule authority to adopt reguirements
to protect the public health. See Kan. Const. Art. 12 Section 5 and K.S.A. Section
12-101a. The County may also want to determine whether such an action would be subject
to the reguirements of Kansas' comprehensive zoning program. See K.S.A. Section 12-741 et
seg.

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d. Outlook

Land use restrictions are implementable and could be effective in the short- and long-run in limiting
harmful exposures to soil and groundwater. They may even result in achieving numerical ARARs (and even
treatment) if the landowner decides to remediate the property so as to seek cancellation of the land use
restriction. However, land use limitations can have practical problems in their enforcement, present
negative effects on non-residential land uses, and be difficult to annul even if no longer applicable.

Alternative 2 - Governmental Land Use Regulations

a. Description

Land use regulations such as zoning, developmental permit systems, subdivision regulations or other broad
governmental reguirements are generally countywide or citywide restrictions that limit land use. Zoning
is the most common form of such restrictions and is commonly used throughout the United States. Such
reguirements, though, must be adopted by action of a governmental body, whether by ordinance or statute,
and therefore, can be subject to change or amendment.

b. Discussion

Zoning, although very effective and implementable, has several shortcomings when viewed in the context of
Cherokee County. First, the County has no existing program for the zoning of properties and the
determination of acceptable activities. Any program would be new. Second, although the zoning of
particular types of land can be selective, zoning programs are the most legally defensible when they are
applicable countywide. Accordingly, a program to zone merely the areas impacted by mining activities,
but not other parts of the county could raise legal concerns. Third, zoning generally entails some
countywide planning. Although, this may have some benefits in Cherokee County, development of "master"
zoning or developmental plans would take time and could prove difficult even if their objectives were
very limited. See Alternative Number 4; infra. Finally, under Kansas law, any governing body which has
enacted a zoning ordinance or resolution is reguired to create a board of zoning appeals, consisting of
not less than three and no more than seven members. K.S.A Section 12-759(a).

c. Relationship to the Selection Criteria

(1) Overall protection of human health and the environment;

Assuming zoning limitations are enforced, location of new residences on unremediated mine waste and use
of shallow aguifer as a drinking water source would be precluded. Human health would be protected.

(2) Compliance with ARARs;

Health risks would be within acceptable EPA ranges by precluding residential use of contaminated areas.
Alternatively, a party could remove chat and/or cover chat and connect to a public water system to avoid
health risks and, therefore, meet the zoning restrictions and be allowed to build and occupy a residence
at the property.

(3) Use of treatment to achieve a reduction in the toxicity, mobility, or volume of
contaminants;

Treatment is unlikely for either mine waste or groundwater. Instead, removal or containment of mine
wastes may occur at some locations. Future residents would most likely connect to a public water system.

(4) Long-term effectiveness and permanence in protecting human health and the environment;

A zoning program, like any governmental reguirement, can be changed by the enacting body. Zoning
restrictions on residential development in Cherokee County could be repealed, but, if other environmental
programs are any indication, it is more likely that the zoning reguirements would form the basis for
additional reguirements, whether or not environmentally motivated.

A concern in the long-term would be whether by a variance or an appeal to the Zoning Board, certain
landowners would be allowed to circumvent the reguirements and build residences on unremediated mine
waste. This though, does not appear likely unless the land owner has been able to bring forward
credible information that the health risks of concern do not exist at the site.

(5) Short-term effectiveness in protecting human health and the environment;

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Development of a zoning program may be slow to implement in the short-term, because the County has no
existing program. A more modest program that only addresses the mine waste concerns would be the
guickest to implement, although uniformity is a legal concern that must be addressed. Once in effect, a
zoning program should be effective and would have the benefit of governmental oversight of residential
development.

(6) Implementability;

The County would be advised to seek outside assistance, including the State and local governmental
organizations in Kansas in developing and adopting a zoning program. Effective January 1, 1992, the
Kansas legislature adopted comprehensive zoning program reguirements that apply in both counties and
cities. 6/ The scope and meaning of the provisions of this new authority is still under development by
the State. 7/ However, it is clear that Cherokee County has broad authority to adopt an array of zoning
reguirements. See K.S.A. Sections 12-753 & 12-755.

Developing the reguisite plans, surveys, ordinance language, will entail a cost and take some time. In
addition, a Board of Zoning Appeals must be constituted, although it is possible that the County
Commission could act as the Appeals Board, since it has at least three members.

Assuming that the County does not try to adopt a comprehensive zoning program, which would simply reguire
more planning and could raise more concerns among the citizens, a more focused program dealing with
mining waste areas should be able to be developed and implemented. Some care would be reguired to ensure
that the reguirements are not a "taking" reguiring the payment of funds or discriminatory because the
reguirements do not apply from a practical matter throughout the County. Working with the State,
particularly the Attorney General's office, such problems may be minimized.

(7) Cost;

Developing a zoning program and its implementation should not be overly expensive in Cherokee County.
The County would have to identify and fund some person(s) who would assist in filling out permits to
build and would be available to undertake enforcement of the program, including site inspections. This
is not seen as a full-time position. If residential development began to grow significantly, user fees
may also be a means of ensuring the program remains solvent.

(8) State acceptance;

The State does not oppose the adoption of zoning provisions by the local Counties, indeed, the "home
rule" provisions of state law specifically allow such actions. Presumably, the State would be a resource
in ensuring that zoning provisions would not conflict with state zoning reguirements.

(9) Community acceptance.

The term "zoning" has certain negative connotations to some in the County and could trigger opposition
even if it was relatively narrowly focused. In part, this is the reason why no zoning program currently
exists. However, since residential development is not active in the County, no one is being immediately
precluded from undertaking a planned action. Support for a zoning program maybe gaining if justified on
human health protective reasons and that the impact on land development is largely positive.
6/ See K.S.A. Section 12-741 et seg. Subsection (a) states:

This act is enabling legislation for the enactment of planning and zoning laws and
regulations for the protection of the public health, safety, and welfare, and is not
intended to prevent the enactment or enforcement of additional laws and regulations
on the same subject which are not in conflict with the provisions of this act.

7/ For example a recent Attorney General opinion responded to a recent reguest for
assistance: "As county counselor for Shawnee County, Kansas you advised us that
since the enactment of K.S.A. 12-741 et seg ... confusion has arise concerning the
filing of certain plats with the register of deeds." See Kan. Att. Gen. Op. No. 93-39
(Mar. 22, 1993).

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d.   Outlook

Zoning, developmental controls, and other broad governmental land use reguirements often are most
effective when a pre-existing zoning program exists that serves as a framework.  At  a minimum, an
existing zoning program has one or more persons already knowledgeable and responsible for its management;
moreover, in Kansas, this would include a functioning board for zoning appeals.  In a county, like
Cherokee, that has no existing zoning program, development of zoning program to achieve mine waste
property control faces practical implementation issues as well as uncertain community support.

Alternative 3 - Dedication of Land for Public Use

       a.   Description

Deeding over of private lands or real estate interests to public agencies or governmental bodies for the
purpose of serving a public benefit including but not limited to park land, lakes, open space, public
recreation or sporting, or other publicly determined uses.  Future use of the land is controlled by the
public entity which can limit uses of the land that could be associated with public risks.

       b.   Discussion

Since the principal risk associated with the mine waste areas involves residential exposure to mine
wastes or groundwater, the dedication of contaminated lands to a public use that would preclude
uncontrolled residential development would protect human health and the environment.  As the site risk
assessment indicates, short-term exposures to the materials, such as trespasser exposures, do not create
unreasonable risks to human health.

However, the large amount of disturbed land and the fact that contaminated areas may be miles apart may
not make this option particularly attractive for most of the two subsites in Cherokee County.  This
approach appears to be most desirable when a single, geographically contiguous site is involved.  The
option may also be advantageous in areas where public parks or recreational facilities are very limited,
e.g. in more urbanized areas.

       c.     Relationship to the Selection Criteria

              (1)  Overall protection of human health and the environment;

Dedicated land would be precluded from residential development and therefore, the types of exposures that
result in health risks would exist.  Other uses of the dedicated land should not create new risks other
than those identified in the site risk assessment.

              (2)  Compliance with ARARs;

Certain standards that were ARARs when disturbed lands were in the private sector may no longer apply to
lands that are dedicated for public uses.  It would be expected that if, for example, that dedicated
lands were used as parks that mine wastes may be removed or contained, although the intensity of such
actions may be driven by environmental rather than human health concerns.

              (3)   Use of treatment to achieve a reduction in the toxicity,  mobility,  or volume of
              contaminants;

Treatment is not expected to play a significant role in this alternative.

              (4)   Long-term effectiveness and permanence in protecting human health and the environment;

Certain covenants can be inserted in grants of land to cities and counties, which when they are not
unconstitutional  (e.g. discriminatory), have been upheld by the courts.  If the County were to sell the
land, it could at that time limit residential development of certain parcels or reguire the purchaser to
ensure that risks to human health are eliminated.  There does not appear to be any reason to believe that
the County would ignore its responsibilities, especially since this is now county land.

              (5)   Short-term effectiveness in protecting human health and the environment;

Getting title to the many parcels of affected land may be difficult and expensive.  This would take a
great deal of time and would be difficult without County intervention.

              (6)   Implementability;

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It is possible to buy all of the areas in which mine wastes or contaminated groundwater are located,  but
as discussed above, this could be very difficult.  While a person may accept a land use restriction,  he
may be unwilling to part with ownership of his land.

In certain areas of the county, it may make sense to buy tracts of land for dedication to the County,
especially if there are strong indications that there are recreational uses or aesthetic values to the
land that the public would enjoy.  However, it is not clear that the County even wants the responsibility
for the numerous acres of disturbed land in Cherokee County, even if the land is free.

              (7)   Cost;

This is likely to be an expensive alternative, unless it is used very selectively.  The costs would be
even greater if considerable land development is anticipated to create recreational or other public use
areas.

              (8)   State  acceptance;

It is possible that certain lands could be dedicated to the State rather than the County, which might
enhance State support.  There appears to be no reason why the State would oppose land dedication to the
County, unless administering the lands would create too great of a financial burden.

              (9)   Community acceptance.

Public acceptance could be a problem if large amounts of land were withdrawn from the private domain,
especially if the land is potentially useful for agricultural purposes.  Like any option involving land
purchase, costs could rise significantly if large amounts of land would have to be obtained.  Finally,
any lands dedicated to the public would have to be maintained, there would be a management cost, even if
activities were limited to ensuring that trespassers were not improperly using the land for residential
purposes, e.g. illegally parking a mobile home on the lands.

       d.  Outlook

Although dedication of land to a public body would significantly limit the use of the lands for
residential purposes, the sheer acreage involved raises practical problems.  It is not clear that any
public body is interested in undertaking stewardship of these lands and the value to the public is
limited by the current availability of private lands for recreational and sporting purposes.

Alternative 4 - Environmental Master Planning

       a.  Description

Creation of a planning commission, likely comprised of representations from Cherokee County,
Baxter-Springs, Treece, Galena, and other interested cities to develop a master plan for dealing with the
short- and long-term development of land and groundwater affected by mine wastes, including appropriate
limitations on land use.   Funding may be available pursuant to recently enacted State statutes. 8/

Any Joint Commission would have to adopt by-laws to govern its operation and conduct public hearings in
adopting any recommendations.  Recommendations could include a multi-faceted approach to dealing with
mine waste lands,  including zoning and subdivision reguirements, park and recreational development, and
other provisions to ensure future use of land protects human health.

       b.  Discussion

Use of a master planning approach to deal with environmental contamination takes a broader look at the
problem and relies, first, upon study and the development of recommendations, rather than assuming that
particular controls, such as zoning are needed.
       8/  See K.S.A.  Section 75-5657,  which provides for grants to local entities for the
      development of environmental protection plans.  These shall include but not be
      limited to a sanitary code, subdivision water plan, public water supply plan, solid
      waste management plan and nonpoint source pollution control plan.

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However, in Cherokee County where current risks to human health do not appear to be imminent (other than
potentially two residences), time may not necessarily be as critical than at other sites. Broader
planning may have certain benefits, for example in dealing with certain unigue site-specific issues. For
example, much of the chat has an economic value and can be beneficially used in asphalt and other
construction materials. Developing a countywide plan for dealing with the use of this valuable chat,
including encouraging sound management of the materials, may be very beneficial in minimizing future
risks to human health.

c. Relationship to the Selection Criteria

(1) Overall protection of human health and the environment;

Planning would result in reguirements that would preclude residential development and exposures to
materials that created unacceptable risks to human health.

(2) Compliance with ARARs;

Certain action-specific ARARs may be achieved and even numerical limitations, but meeting ARARs is not
the principal focus of master planning.

(3) Use of treatment to achieve a reduction in the toxicity, mobility, or volume of
contaminants;

Treatment is not a likely result of this alternative.

(4) Long-term effectiveness and permanence in protecting human health and the environment;

If adeguate resources are devoted to the planning effort, this option could be very effective into the
future. The principal problem in Cherokee County is that significant commercial or residential
development has not occurred; instead, the area remains heavily dependent upon agriculture. Accordingly,
a "master plan" that addresses residential development may simply be too speculative at this time and
therefore, ineffective and subject to future revision.

(5) Short-term effectiveness in protecting human health and the environment;

Since longer-range planning is involved, short-term effectiveness would be minimal, especially when
compared to the other more focused alternatives.

(6) Implementability;

Under Kansas' new zoning authorities, counties have the authority to create planning commissions,
including joint county-city groups, and to appoint members who serve without compensation. See K.S.A.
Section 12-744. The Commission is also authorized to adopt comprehensive land use plans, subject to
review and approval of the County and participating cities. K.S.A. Section 12-747. Accordingly, there
is no lack of legal authority to implement master planning.

However master planning is intended to result in comprehensive land use controls, including zoning, and
therefore raises some of the same implementation problem as zoning (Alternative No. 2), i.e., identifying
both planning board members and zoning appeals board, finding ways to finance the preparation of studies
or reports on specific problems, and potential public opposition. However, master planning greatest
impediment to implementation is likely to be costs, and therefore, outside funding whether from the state
or other source may be important in implementing this alternative.

(7) Cost;

Depending upon the level of sophistication, for master planning studies to be useful, generally they must
address a broad range of issues and therefore, can be costly. The utility of these studies in Cherokee
County, which is not currently undergoing significant land use development may be very limited at this
time. Therefore, the cost-effectiveness of this alternative may be low.

(8) State acceptance;

Generally State agencies support a methodical, longer-range approach to environmental issues based upon
sound studies. The State, though, may be concerned that such solutions are too far in the future and the
value of such studies in solving the site problems is minimal.

(9) Community acceptance.

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County residents appear to want action and not more studies of these sites. A master planning effort,
without more focused components is not likely to be supported.

d. Outlook

Master environmental planning does not appear to focus as guickly on the future risk issues related to
exposure to mine wastes and use of the shallow groundwater as would other alternatives. Although
planning is probably a sound approach in theory, in reality, this area is likely to remain primarily
agricultural for the next decade and therefore, any planning effort would have to very focused on mine
waste issues to be of much practical use. Like zoning, master planning may be premature for the county
at this point.

Alternative 5 - Environmental Construction Code

a. Description

Specific reguirements adopted by the county to govern the building of residences in areas in which mine
materials are located and there is potential access to the shallow aguifer. Residential development
within certain designated areas of prior mining activity in the County would be prohibited until the
filing of an application for an environmental occupancy permit. A permit would issue when an authorized
county representative determines that building standards based upon prevention of unsafe exposures to
mine materials or contaminated groundwater have been satisfied and risks have been reduced to acceptable
levels.

b. Discussion

Adoption of an Environmental Construction Code would be pursuant to Cherokee County's inherent police
powers to protect citizens from unreasonable risks to health and safety rather than state zoning
authorities. 9/ In this regard, the code may have more flexibility in not having to be uniformly applied
to areas of the county in which mining activities have not taken place.

Implementablilty would be through the County's adoption of an ordinance that would preclude occupying any
residence that was located within an area in which mine wastes were found without taking steps to ensure
that exposures to mine waste materials were within acceptable levels. Standards for soils and mine waste
materials could rely upon numerical standards or performance standards, such as ensuring mine waste
materials in future residential areas are removed, graded, covered by soils or other clean cover, or
similar reguirements. Standards for groundwater protection would include connection to local water
systems or the use of an acceptable water supply and a prohibition on using the shallow aguifer as a
drinking water source.

Such a program, has been raised with the Cherokee County Commissioners who have expressed interest in the
program. A model code provision has been prepared and is attached to this addendum. See Attachment 1.

9/ Adoption of an environmental construction code would appear to be authorized under
the County's "home rule" authority. See Kan. Const. Art. 12 Section 5 and K.S.A.
Section 12-101a. Home rule authority exists for a County: (1) where the legislature is
silent on a subject and the legislation is not prohibited by constitutional or statutory
home rule provisions, (2) to exercise police power to regulate the health, safety, and
welfare of the public, and (3) where state legislation is available, but is not uniformly
applicable to all cities and counties. So Blevins v. Hiebert, 247 Kan. 1, 795 P.2d
325 (Kan. Sup. Ct. 1990). In adopting such an ordinance, the County would be using
its home rule "police power" to protect human health by limiting access to mine
wastes and contaminated groundwater.

One issue, though, that may need to be investigated with the Attorney General is
whether the existence of Kansas' new zoning authorities would preclude the use of
home rule to adopt such a restriction; rather, the County would have to act in
accordance with the zoning authority. K.S.A. Section 12-741(a) of the zoning
authority indicates that it "is not intended to prevent the enactment or enforcement of
additional laws and regulations on the same subject that are not in conflict with the
provisions of this act." Such restrictions as the environmental construction code do
not appear to be in conflict with the zoning reguirements, although it may be prudent
to ensure that any public participation reguirements associated with the zoning
authority be compiled with in exercising home rule authority to adopt an
environmental construction code.

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C. Relationship to the Selection Criteria

(1) Overall protection of human health and the environment;

Residential development would be prohibited unless an environmental occupancy permit was obtained.
Permit will not issue if site risks are present, such as location of the residence on mine wastes and
lack of acceptable drinking water source.

(2) Compliance with ARARs;

Cover or removal of chat to reduce site risks and installation of acceptable drinking water system would
be reguired to obtain environmental permit. Compliance would focus on meeting action-specific ARARs.

(3) Use of treatment to achieve a reduction in the toxicity, mobility, or volume of
contaminants;

Treatment of wastes would be unlikely. Cover and containment would be used to reduce site risks.

(4) Long-term effectiveness and permanence in protecting human health and the environment;

Although the program could be abandoned or changed by the County, its relative simplicity in
administration supports its continuation. It may be likely to serve as the basis for other types of
building reguirements that improve the safety of residences and other buildings. The program does not
reguire a large commitment of sophisticated manpower and therefore, could be implemented and maintained
by existing County personnel. Program is sufficiently flexible to allow for the building of individual
residences with site-specific remediation. This would appear to enhance its likelihood to remain in
effect and to protect human health into the future.

(5) Short-term effectiveness in protecting human health and the environment;

Program would not take considerable planning to implement and would immediately preclude unpermitted
residential development. As discussed, could be implemented with existing County staff and would not
reguire significant new resources to be brought on-line.

(6) Implementability;

A model ordinance has been developed and reviewed by the County Commission and County Attorney. As
discussed above, it may be prudent to ensure hearings and other public participation reguirements be
followed to ensure that the ordinance is on sound legal grounds. Questions could also be addressed to the
Kansas Attorney General's office.

The County Health Officer would be the principal official charged with the program implementation and
oversight. Relevant duties are expected to reguire only part-time efforts. Maps of affected areas have
been developed and other permitting materials should be able to be developed guickly.

Cooperation among EPA, Kansas, and the County would be useful in determining what must be done at a site
from a remedial perspective to allow occupancy, especially with regard to mine wastes. However, assuming
that the residence is not a mobile home, excavation of a foundation and the grading of the home site may
be compatible with other approaches for reducing site risks.

(7) Cost;

Costs of the program should not be significant. Determination of the need to file an application is
based upon an inspection of a map. Applicant for permit then has responsibility to show that any risks
have been abated. Visual inspection of a site to ensure risks have been addressed would involve some
costs as would administration of the permitting program. Permit fees may off-set many of these costs.

(8) State acceptance;

No anticipated state opposition, although certain legal issues associated with the use of the County's
police powers may arise and will have to be addressed.

(9) Community acceptance.

This program is far less complex and broad than a zoning program. Preliminary indications from the
County have been favorable. Program would not interfere with non-residential development of property,
including agricultural and beneficial use of mining materials.

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d. Outlook

The program focuses specifically on the future risks identified as of concern in the RI/FS and does not
appear to require the creation of planning boards or boards of appeals. The County Commission would
serve as the arbitrator of any appeals from the denial of an occupancy permit.

In implementing the program, the county would need to define the types of building standards needed; this
would likely entail input from EPA and the state. However, site preparation for residential development
may typically involve activities which would assist in reducing potential exposure risks, e.g. removal of
chat, bringing in top soil for cover, and the planting of a lawn, etc.

Alternative 6 - Contractual Agreements

a. Description

A contract is a legally enforceable agreement between one or more parties who agree to either perform or
refrain from performing certain actions for money or other valuable consideration. Contractual agreements
normally apply only to the persons or organizations that execute the agreement, although certain
contracts have been deemed to create third party beneficiaries to the agreement. Contracts involving
site remediation could be executed with land owners to refrain from certain actions, such as residential
development or use of the shallow aguifer at a site. Contracts could also be executed with governmental
bodies to agree to keep certain programs in effect, to accept oversight responsibilities, or to undertake
other actions.

b. Discussion

Contracts are an extremely flexible means of accomplishing specific objectives. When private parties are
involved, such contracts may allow for the recovery of damages or provide the basis for injunctive relief
if provisions are breached. Contracts could address the right to perform site development, land purchase
options, notifications of intent to sell or develop or any number of duties that may be helpful in
ensuring persons are not subjected to conditions of risk.

Governmental bodies generally have the right to make contract for necessary services and for other public
purposes. In Kansas, though, the provisions of "home rule" may need to be considered with regard to a
county's authority to enter into particular contracts. Contracts that are deemed to not be in the public
interest can be rendered void.

c. Relationship to the Selection Criteria

(1) Overall protection of human health and the environment;

Depending upon the nature of the agreement, a contract could preclude locating a residence on mine waste
and using the shallow aguifer as a source of drinking water. It could also include other measures to
control site risks within acceptable levels.

(2) Compliance with ARARs;

Agreements are more likely to call for compliance with action-specific ARARs rather than numerical ARARs.

(3) Use of treatment to achieve a reduction in the toxicity, mobility, or volume of
contaminants;

Treatment is not expected in using the contractual alternative.

(4) Long-term effectiveness and permanence in protecting human health and the environment;

Contracts bind individual parties, and unlike land restrictions, may not be enforceable against new
owners. Contracts may have a longer duration when agreed to by a governmental entity that would remain
in existence. Although a contract can have predetermined remedies in the event of a breach, generally
some entity is needed to enforce the contract. Contracts can also be renegotiated among the parties and
terminated by mutual agreement.

(5) Short-term effectiveness in protecting human health and the environment;

A contract with particular individuals may be a very effective means of eliminating certain risks in an
expeditious fashion and at a reasonable cost. However, as a sole institutional control, probably too
many individual agreements would have to be negotiated to be considered effective in the short-term. An

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agreement with the County, provided adequate consideration is involved, could bind the County in the
short- and long-term to continue to provide services including program administration and enforcement.

              (6)   Implementability;

Use of contracts to control certain individuals or the County is feasible and implementable. However,
sole reliance on contracts would be difficult in light of the large number of persons that could be
involved.  Contracts also would not necessarily survive the sale of land, although, the contract could
require notice be given that land on which mined waste is located before being sold.

Enforcing, a contract requires resorting to court, unless some method of binding arbitration is included.
It is often difficult for any individual who is not a party to bring action under a contract, even if it
would derive a benefit  (third party beneficiary).   Liquidated damages or provisions controlling specific
performance may be very useful in dealing with disputes over site risks.

              (7)   Cost;

A valid contract requires valuable consideration,  although the scope of the contract duties control the
price.  Costs could be high if contracts were the only means of limiting site access and many land owners
would have to be consulted.  However, selective use of contracts, especially with the County, may not be
particularly costly and effective.

              (8)   State acceptance;

State opposition would not be expected.

              (9)   Community acceptance.

Assuming that the contracts were fair to the affected parties, no great opposition would be expected.

       d.  Outlook

Although contractual arrangements on a person-by-person basis may be very difficult in many areas of the
Cherokee site, contractual arrangements with particular individuals or the county may prove very,
effective in assuring compliance with certain requirements. Monitoring compliance with the contract can
be a problem and if the contracting party is rendering some service, then, problems with the quality and
consistence of performance can arise.

Alternative 7 - Financial Instruments or Arrangements

       a.  Description

Insurance policies or financial instruments such as bonds, trusts, escrows, or deposits that can serve a
variety of uses at a site to encourage, protect, and reward cooperation in reducing exposures to
potential risk situations.  For example,  insurance coverage might be offered to private parties that are
concerned that their remediation of certain conditions at a site could expose them to Superfund
liability.  Another example could be a trust or escrow account administered by a third party trustee
which could be tapped to assist in funding governmental programs that administer or enforce permit or
zoning programs; it could also assist private parties afford user fees.  Pools or funds could also assist
certain types of private remediation or provision of alternate water.

       b.  Discussion

implementation of such financial mechanisms would not appear to be particularly difficult, although the
particular means for providing funds to a local or state government may have to be accompanied by other
agreements to ensure that transfer of funds to the government is legally proper.  Nonetheless, financial
pools that augment or act as backups to local programs can provide substantial incentive to keep a
successful exposure control program in effect.  Often the financial pool, by virtue of its ability to
draw interest can be self-financing into the future or until the obligation is satisfied.

       c.     Relationship to the Selection Criteria

              (1)   Overall protection of  human health and the environment;

The goal would be to use financial incentives to insure overall protection of public health.

              (2)   Compliance with ARARs;

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Financial mechanisms could be used to encourage meeting action-specific ARARs and to keep in maintenance
a program that reguired ARARs to be met.

              (3)   Use of treatment to achieve a reduction in the toxicity,  mobility,  or volume of
              contaminants;

Treatment is not expected to be the major function of the financial instrument, but rather to
ensure site risks are minimized.

              (4)   Long-term effectiveness and permanence in protecting human health and the environment;

The principal concern is that there is adeguate funding to ensure that long-term effectiveness is
maintained.  The five year EPA review could include an evaluation of the adeguacy of any financial
instrument or arrangement in achieving the continuation of the program and the protection of public
health.  Interest would augment any funds invested in a pooling agreement.

              (5)   Short-term effectiveness in protecting human health and the environment;

A financial instrument or arrangement could be expeditiously put into place and could be tapped to fund
agreements with private parties or the County to address any short-term risks. Since there is great
flexibility in the types of financial arrangements available, one approach could be implemented in the
short-term while mechanisms for dealing with the longer-term needs are determined.

              (6)   Implementability;

There is a great deal of flexibility in the array of financial instruments or agreements that could be
selected to achieve objectives.  Managing the disbursement of money in a manner that avoids depletion of
the fund, yet ensures desired actions are undertaken is an important consideration.  To this end, the
selection of an independent trustee to manage the fund in a sound fiscal and impartial fashion could be
beneficial, since those who fund the account and those who may benefit have to feel fairly treated.
Determining initial payments into a trust or the amount of life insurance or bond coverage will be the
most difficult process, although this should be able to be settled with outside assistance.   This
alternative would appear to be a good solution both in the short-term and long-term, if cost projections
are reasonably accurate.

              (7)   Cost;

If used to fund County administration and enforcement of a permit program, like the environmental
occupancy permit program, costs may not be extremely large.  If wide-scale remediations are to funded,
costs could rise substantially.  Good administration of the financial program would avoid transaction
cost losses.

A trust account or financial pool, using expected annual program costs and expected rates of return for
trust funds would be a practical method of financing over the long-run. Determination of initial deposit
would be determined after program elements are determined.

              (8)   State acceptance;

Assuming that funding is adeguate, there should be no significant State opposition.

              (9)   Community acceptance.

Again, if funding is adeguate and the instrument or fund is fairly administered, there should not be
community opposition.

       d.  Outlook

Use of these mechanisms is likely to complement other institutional controls whether public programs or
private agreements.  EPA's five year review authority could be invoked if coverage or pools prove to be
inadeguate due to unusual circumstances.

Alternative 8 - Physical Barriers/Surveillance

       a.  Description

Access barriers to prevent human exposure to mine wastes and contaminated groundwater include fences,
warning signs, security systems, surveillance systems, guards, and other types of systems that would

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limit physical access.

b. Discussion

Perhaps the simplest means of restricting access, especially to areas of immediate or acute risks, these
restrictions appear to be most suited to selective, localized use. These controls may be effective on a
interim basis while longer-term approaches are being devised.

c. Relationship to Selection Criteria

(1) Overall protection of human health and the environment;

Such barriers would prevent contract with mine wastes, but would not be particularly effective in dealing
with groundwater contamination. Local water wells are often difficult to visually identify depending
upon the terrain.

(2) Compliance with ARARs;

Compliance with ARARs, other than to limit direct access, would be very limited.

(3) Use of treatment to achieve a reduction in the toxicity, mobility, or volume of
contaminants;

No treatment is expected to result from the use of access barriers.

(4) Long-term effectiveness and permanence in protecting human health and the environment;

These types of access barriers may not be particularly effective in the long-run unless they are
maintained and regularly monitored. Fencing unless repaired when broken will provide no protection,
although trespassing is not considered to be a high risk to human health.

(5) Short-term effectiveness in protecting human health and the environment;

These access barriers used selectively could be very useful at individual areas in the short-term.
Again, maintenance and oversight is needed.

(6) Implementability;

Obtaining the authority to place a fence or another structure on private land would probably reguire the
cooperation of the site owner. Wide scale reliance on such barriers is probably infeasible and would
become increasingly a problem over the long-term. However, such access barriers if regularly monitored
could provide immediate assistance in problem areas, where access by children is expected to be a
problem.

(7) Cost;

Cost could be more significant if considerable acreage is involved and personnel must be hired to
undertake long-term monitoring. Such barriers may not be considered cost-effective when compared to
other approaches which provide longer term benefits.

(8) State acceptance;

There should be no significant State opposition, so long as this is not the only institutional control.

(9) Community acceptance.

Limited access barriers may be acceptable so long as they do not overly limit private use of land that is
not likely to be developed for residential use or to be subject to substantial trespass.

Alternative 9 - Public Education Programs

a. Description

Organized efforts to prepare educational materials for private citizens and governmental officials to
explain available methods for reducing risks of exposure to hazardous substances whether located at
Superfund sites or associated with other residential and local conditions, and to apprize individuals,
especially those who could be of special risk, of health effects testing or other treatment that may be

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useful in dealing with exposures.

b. Discussion

Avoiding exposures to certain materials is a means of protecting public health, especially if the
measures are relatively non-intrusive. For example, the RI indicates that children and pregnant women
are most at risk from lead exposure, however, the risk for children may be lowered by good hygiene, such
as having children wash their hands before eating if they have been outdoors and exposed to mine waste
materials; other measures include avoiding the use of chat or mine tailing in areas where children play,
e.g. sand boxes. People also need to be apprized of other sources of exposure to lead such as lead paint
in houses, lead drinking water piping, and, to a lessening degree, lead in motor vehicle exhaust and
suggestions for lowering risks.

c. Relationship to the Selection Criteria

(1) Overall protection of human health and the environment;

The goal of the program would be to inform people how they can lower their risks to lead and other
potentially harmful materials and to assist them in reducing risks.

(2) Compliance with ARARs;

An education program would not necessarily ensure compliance with ARARs, but would explain how to
minimize risks of contact with mine wastes and contaminated groundwater.

(3) Use of treatment to achieve a reduction in the toxicity, mobility, or volume of
contaminants;

No treatment would be achieved.

(4) Long-term effectiveness and permanence in protecting human health and the environment;

If continued into the future and made part of the County's educational curriculum, health programs, and
governmental information releases, the program would continue to educate persons about the risks of
exposure to heavy metals. As more persons are aware of risk, there is a continued dissemination of
information.

(5) Short-term effectiveness in protecting human health and the environment;

This program could be very effective in the short-term, especially with regard to children being exposed
to lead. Many simple means are available to reduce lead exposures, including avoiding the use of chat or
tailings in sandboxes or in driveways; removing lead paint used at a residence; good hygiene, especially
washing children's hands before meals; and allowing tap to run for a few minutes before drawing drinking
water in homes with lead piping. Most of these precautions could be immediately undertaken and would be
effective in the short-term. Since health effects from certain lead exposure are reversible, short-term
action could be very effective from a health perspective.

(6) Implementability;

The educational program would not be complex to implement. Educational materials would have to be
produced and County personnel apprized of any special risks and control measures for reducing risks.
Outside groups, such a schools, hospitals, and the media would be expected to assist in this effort.

Discussions with the Cherokee Health Officer indicate a willingness to implement such an education
program. The basics of such program are contained in Attachment 2 to this addendum.

(7) Cost;

Short-term costs would be moderate and expected to be reasonable in light of the value of heightening
public awareness. Long-term costs would be subject to planning and evaluation of how to ensure adeguacy
of continued educational efforts.

(8) State acceptance;

State support would be expected.

(9) Community acceptance.

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Preliminary discussions with County personnel have been favorable.  Community acceptance would be
expected.

       d.  Outlook

Since there are certain measures that private citizens could take to lower potential exposures to certain
heavy metals such as lead, implementation of a public education program would appear to have significant
benefits at very low costs.  The key will be the steps that must be taken to institutionalize the program
so it can continue to prompt protective behavior into the
future.

IV.    Summary Comparison of the Institutional Control Alternatives

       A.  Primary Versus Supplementary Institutional Controls

The preceding evaluation of the various institutional control candidates for use at the Baxter-Springs
and Treece subsites indicates that there are potential benefits in the use of each of the various
options, however, several of the candidates are not "stand alone," remedial alternatives.  For example,
the expected effectiveness of alerting citizens to the potential hazards posed to children and pregnant
women of exposure to lead and other heavy metals and the steps that can be taken to lessen exposure
should not be undervalued merely because this alternative is not a legally enforceable access limitation,
like a deed restriction or local land use ordinance.

Basically the institutional control alternatives fall into two broad categories: (1) alternatives that
would be a "primary" means of controlling use of an area for residential development and (2) alternatives
that would "supplement" primary control options to enhance reliability or permanence.  The primary
control alternatives would include: Alternatives No. 1 (deed restrictions), No. 2 (governmental land
use/zoning), No. 3  (dedicated land use),  No. 4  (master planning) and No. 5 (environmental construction
code).   The "supplementary" institutional controls would be the remaining four alternatives including No.
6  (contracts), No. 7 (financial arrangements), No. 8 (access barriers) and No. 9 (public education).

Based upon the foregoing evaluation, implementation of an effective program of institutional controls
would entail the selection of at least one "primary" control alternative.  This alternative would be
expected to provide the principal means of ensuring protection of human health by controlling future
residential development in affected areas.  Since almost all of the primary control alternatives
discussed above rely either upon the action of a private individual or the government to oversee the
alternative's implementation and enforcement, some additional "supplementary" control may be warranted to
enhance reliability and permanence of the primary institutional control.  Accordingly, it is anticipated,
that the use of institutional controls would be a "package" of primary and supplementary controls.  This
approach appears to have been used at other sites which have utilized institutional controls.

In addition, if there were "special situations" caused by either unique site-specific conditions,
recalcitrant land owners, or other conditions, any one of the above institutional controls may be useful
on a "special circumstances" basis.  One of the most obvious "special circumstances" controls discussed
in the addendum is the use of the public education program, Alternative No. 9, to assist individuals from
exposing themselves and their children to avoidable risks.

Using a combination of one or more institutional controls, would strengthen compliance with the nine
selection criteria; this is wholly consistent with the goal of the NCP in the selection of a remedy.   It
also utilizes the flexibility and discretion that EPA has signaled in the NCP as appropriate in the use
of institutional controls.

       B.  Preliminary Observations on the Alternatives

The goal of this addendum was to explore the various types of institutional controls that have been
suggested as useful at CERCLA sites and determine, using EPA selection criteria and other information,
whether certain of the alternatives should presumptively be screened out as impractical or whether other
alternatives are clearly preferred for use at the Baxter-Springs and Treece subsites.  Regardless of
whether one or more of the alternatives are ultimately selected for use by EPA, many details remain to be
resolved before concluding that any of the alternatives actually fulfill the selection objectives.

However, based upon the above analysis, certain factors appear evident.  First, in light of the lack of
any pre-existing land use program in Cherokee County or private interests that would be pushing for such
programs to be developed, any "primary institutional land use control program to be expeditiously
implemented must be relatively simple and well-funded.   The County does not have the resources nor are
there other parties in the County with resources willing to bring about such land use programs.

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Second, a focused program that specifically addresses the potential future risks of residential
development of areas affected by mining wastes is likely to be easier to implement and to finance both in
the short- and long-term. As a program becomes more complex, it is difficult to predict resource needs.

Third, of the primary institutional control options, Alternative No. 5, the environmental construction
code alternative is currently the most developed in terms of its content and its scope. A model
ordinance has been prepared and reviewed by the County Commission. Although each of the other control
options are implementable and would appear to be potentially reliable each has certain limitations to
their implementability. Zoning or other land use ordinances may reguire planning and appointment of
governmental infrastructure, although this is not a substantial burden. Deed restrictions will be
difficult to obtain complete participation unless the County, State or EPA intervenes to force uniform
cooperation. Dedicated land and master planning may involve more participation than what is currently
desired or practical for the County.

Fourth, supplementary controls may be warranted to adeguately fund any of the "primary" institutional
control programs. Supplemental controls could represent an effective means for meeting the selection
criteria reguirement of permanence and reliability. Of the available alternatives, No. 7, which
specifically discusses the use of one or more of the following — insurance, trust funds, bonds or other
financial agreements -- to support and enhance the development and implementation of a primary
institutional control, appears to be the most attractive. A fund that could disburse funds to the
County, but also draw interest and be managed by an impartial trustee, appears to be an attractive
mechanism for addressing the issue.

Finally, Alternative No. 9, the public education program is a narrowly focused alternative. However, its
expected effectiveness suggests that it be carefully considered along with the primary and supplementary
control alternatives.

The level of funding for institutional controls will depend on which controls are selected, the
anticipated level of residential development in the county, and a number of other important factors. The
FS assumed institutional controls would cost around $400,000 to fully implement and maintain. Based on
the current lack of development in the County, this could be a significant overestimate.

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ATTACHMENT 1

RESOLUTION NO.

A RESOLUTION ADOPTING AN ENVIRONMENTAL HEALTH PROGRAM FOR THE
PROTECTION OF THE PUBLIC HEALTH AND SAFETY FOR THE DEVELOPMENT OF
PROPERTY LOCATED IN THE CHEROKEE COUNTY SUPERFUND SITE.

Whereas, mining in the Kansas portion of the Tri-State Mining District occurred from about 1876 to 1970,
and

Whereas, this mining activity resulted in the deposition of unprocessed and processed mine wastes on the
land surface at several locations in Cherokee County, and

Whereas, the ore deposits mined were located in geologic formations containing water and locally known as
the shallow aguifer, and

Whereas, the mineral extraction from these formations modified the hydrogeology and potentially altered
the concentration of several metals in the water of the shallow aguifer, and

Whereas, the U.S. Environmental Protection Agency (EPA) designated this area of southeastern Kansas as
the Cherokee County Superfund Site in 1983 and initiated investigations, and

Whereas, these investigations identified potential risks to human health from long-term, continued
incidental ingestion of mine waste and/or consumption of water from the shallow aguifer in the vicinity
of the ore deposits, and

Whereas, the Cherokee County Commission is authorized by the State of Kansas to exercise the use of
police powers to protect the health, safety and welfare of the citizens, and

Whereas, the expressed intent of the Cherokee County Commission to protect the health, safety and welfare
of the citizens of Cherokee County.

NOW, THEREFORE, BE IT RESOLVED BY THE COUNTY COMMISSION OF CHEROKEE COUNTY, KANSAS:

ARTICLE 1. ENVIRONMENTAL HEALTH PROGRAM FOR THE CHEROKEE COUNTY
SUPERFUND SITE

Section 1. Purpose and Intent.

The purpose and intent of the Environmental Health Program is to protect the public health in
formerly mined areas of the Cherokee County Superfund Site. The program will limit potentially
excessive exposure to metals from surface mine wastes and shallow aguifer water. Building sites for
building or structures for human occupancy, proposed to be built on surface mine wastes, will be reguired
to be remediated to prevent ingestion of the mine waste. Buildings for human occupancy will also be
reguired to provide safe and potable water.

The administration and geographic application of the Environmental Health Program is limited to that area
of the Cherokee County Superfund Site where there is a potential for excessive human health risk due to
exposure to metals. This resolution shall not affect the use of property, density of development,
building construction, or subdivision of the land within the Cherokee County Superfund Site.

Section 2. Definitions.

A. Applicant: The property owner, or duly designated agent of the property owner, of land on
which the construction activity will occur.

B. Building or structure: A structure including enclosed space surrounded by exterior walls
designed, intended or used for occupancy by persons. Included by way of definition are site built homes,
mobile homes, and manufactured homes.

C. Cherokee County Superfund Site: An area of approximately 25 sguare miles in the southeastern
corner of Cherokee County, Kansas that has been designated by the US Environmental Protection Agency

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(EPA) as a superfund site under the Comprehensive Environmental Response, Compensation and Liability Act
of 1980 (CERCLA or Superfund). The Cherokee County Superfund Site has been divided into six subsites
representing the areas of former lead and zinc mining within the Kansas portion of the Tri-State Mining
District. These are the Galena, Baxter Springs, Treece, Badger, Lawton and Waco subsites.

D. Construction Envelope: The limits of construction activity associated with the building or
structure, including the site area devoted for front, side and rear yard areas.

E. Cover Material: Uncontaminated soils or other suitable coverings to prevent the ingestion of
surface mine waste material.

F. Director of Public Health: The person designated by the County Commission as the Public
Health Officer of the County, also refers to his or her designated representative.

G. Ground Water Assessment Area: The area of the Cherokee County Superfund Site where metal
concentrations in the shallow aguifer could potentially exceed the State of Kansas' safe drinking water
standards in relation to former mining operations.

H. Surface Mine Waste Assessment Area: The area of the Cherokee County Superfund Site containing
surface mine waste material. The definition includes areas containing accumulations of surface mine
wastes, areas formerly covered with surface mine wastes and now partially reclaimed, and other areas
associated with prior mining activities and potentially containing elevated soil metals concentrations.

I. Surface Mine Waste: Processed or unprocessed earthen material deposited on the surface by
prior mining activities including development rock, mill tailings, chat and slag.

J. Shallow aguifer: Ground water in the Mississippian Formations which generally occur at depths
between the surface to between 150 feet and approximately 1000 feet below the ground surface at the
Cherokee County Superfund Site.

K. Temporary water source: The use of bottled water or other means of water imported to the site
as approved by the Director of Public Health.

Section 3. Applicability of the Environmental Health Program.

A. Environmental Health Assessment Areas. Central to the administration of the Environmental
Health Program is the creation of two environmental health assessment areas, the Surface Mine Waste and
Ground Water Assessment Areas. This resolution shall be restricted to property to be improved for human
habitation that is totally or partially within either or both of these assessment areas. The Surface
Mine Waste Assessment Area shall be established to address the potential health risks associated with the
ingestion of mine wastes. The Ground Water Assessment Area shall be established to address the potential
health risks associated with the consumption of water from the shallow aguifer. These two assessment
areas have been delineated and are shown on Exhibit One and Two.

B. Uniformity in Application. This resolution shall be uniformly applicable to all residential,
commercial, and industrial development for purposes of human occupancy or habitation. The use of land
for agricultural purposes is exempted from the resolution. This resolution shall be applied to land and
structures intended for public or guasi-public use or occupation by the general public.

C. Non-conforming Structures. This resolution shall not apply to structures built before the
adoption of this resolution. Structures built before the adoption of this resolution shall be considered
legally non-conforming. A non-conforming building or structure may be remodeled or expanded. A
non-conforming building or structure may be replaced or restored within nine months of damage or
destruction of not more than 50 percent of its appraised valuation by fire, explosion, or act of God. A
lawful non-conforming building or structure that is damaged more than 50 percent of its value may not be
rebuilt, repaired, or used unless it is made to conform to the regulations of this resolution.

Section 4. Administration and Enforcement

The County Director of Public Health shall be responsible for the administration and enforcement
of the Environmental Health Program. The Director of Public Health is authorized to inspect the
construction site or building to ensure compliance with the provisions of this Article.

Section 5. Methods of Site Remediation for Construction in the Surface Mine Waste Assessment Area.

A. Application. The construction of buildings or structures totally or partially within the
Surface Mine Waste Assessment Area shall be reguired to meet the standards and provisions of this

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Section. Site remediation is limited only to the construction envelope where the building or structure
is proposed.

B. Methods of Site Remediaton. Site remediation shall comply with one of the following accepted
methods. The intent is to have the surface mine waste material buried, covered, or removed from the
construction envelope to prevent human ingestion.

(1). Excavation and removal to on-site or off-site areas.

(2). Covering with topsoil, concrete or other uncontaminated suitable
material to prevent ingestion of surface mine waste material.

C. Alternative Site Remediation Methods. The Director of Public Health is authorized to approve
alternative methods of site remediation that comply with the intent of ensuring a safe and clean site.
The Director of Public Health may request a professional engineer to submit a certified report outlining
the alternative method of site remediation. This report shall detail the techniques of site remediation
and methods employed to ensure code compliance with this Article.

Section 6. Potable Water Supply Source.

A. Application. All structures for purposes of human occupancy in the Ground Water Assessment
Area shall be supplied water from a Rural Water District, municipality, or other reliable source of
drinking water that meets the State of Kansas' drinking water standards in order to receive an
Environmental Health Certificate. The use of water from the shallow aquifer in the Ground Water
Assessment Area shall be limited to agricultural and other non-potable purposes, unless a specific
determination is made under Section 6 B.

B. Alternative Water Sources. The Director of Public Health is authorized to approve alternative
water sources, provided they insure a safe and permanent source of water. The Director of Public Health
may request a licensed laboratory to submit a certified report outlining compliance with the State of
Kansas' requirements for safe water. The report shall outline the monitoring, maintenance or testing
methods to ensure permanent compliance if needed. The Director of Public Health is authorized to require
testing of alternative water sources when deemed necessary. All costs associated with an alternative
water source, including periodic testing, shall be the responsibility of the applicant.

Section 7. Procedural Process of the Environmental Health Program.

A. Procedural Overview. The procedural process of the Environmental Health Program involves an
initial, two-step procedure. The initial, first-step is for all landowners within the Cherokee County
Superfund Site to verify if their property is located within an Environmental Health Assessment Area.
The second-step is for the landowner to apply for and obtain an Environmental Health Certificate, if
required due to location within an Environmental Health Assessment Area.

B. Assessment Area Verification. Each landowner located within the Cherokee Superfund Site shall
be responsible for contacting the Director of Public Health prior to construction to obtain verification
as to whether their proposed building or structure is located within one or both of the Environmental
Health Assessment Areas. If the building or structure is not located within an assessment area, then the
landowner is authorized to commence construction. If the Director of Public Health determines the
proposed building or structure is located in an Environmental Health Assessment Area the Environmental
Health Certificate is required.

C. Method of Assessment Area Verification. The Director of Public Health shall use the Cherokee
County Environmental Health Assessment Map for verification, along with an on-site inspection of the
property when warranted.

Section 8: General Procedures for the Issuance of an Environmental Health Certificate

A. Approved Application Required. No person, firm, corporation or governmental agency shall
erect, construct, excavate for, or convert any building or structure designed or intended to be inhabited
or occupied by humans, or do any work regulated by any portion of this resolution, or cause the same to
be done, without first obtaining an approved application for an Environmental Health Certificate for
buildings or structures proposed to be located within one of the Environmental Health Assessment Areas.

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B. Time frame for Certificate Issuance.

(1) . It shall be the duty of any landowner for determining whether a proposed building or
structure requires an Environmental Health Certificate and to submit an application in
accordance with Section 11 for the Environmental Health Certificate to the Director of
Public Health.

(2). The Director of Public Health shall have a maximum of ten working days to review and approve
or deny an application for an Environmental Health Certificate. A denial of an application
shall be accompanied with a written explanation of the reasons for denial. If an incomplete
application is submitted, the Director of Public Health shall ask the applicant to resubmit
a complete application. The ten day review period begins with the submission of a complete
and accurate application form. The Director of Public Health shall mail the approved or
denied certificate application or the applicant can obtain the approved or denied
application from the office of the Director of Public Health.

(3) . The approval of an application for an Environmental Health Certificate shall expire by
limitation and become null and void if the building or work approved is not commenced within
180 days of the date of approval. The Director of Public Health may grant extensions upon
just cause.

(4). After inspection of the site and upon determination that applicant has met all requirements
of the Sections 8, 9, and 10, the Director of Public Health shall issue to the applicant an
Environmental Health Certificate.

(5). The County Commission may establish a fee for application for and issuance of an
Environmental Health Certificate. Such fee shall be based upon the administrative and
inspection costs associated with the issuance of the Environmental Health Certificate. Any
fee shall be established by separate resolution of the County Commission.

C. Certificate Required. No person, firm, corporation or governmental agency shall inhabit or
occupy, or allow any person to inhabit or occupy, any building or structure subject to requirements of
this resolution that has not been issued and maintains a valid Environmental Health Certificate.

Section 9. Specific Procedures for the Ground Water Assessment Area.

A. Documentation. The applicant shall be responsible for providing the Director of Public Health
with written documentation from an official agent of a reliable water source that potable water is or
will be available to the building or structure. Submission of said documentation, along with the
completed certificate application, will initiate the issuance process by the Director of Public Health.

B. Timing of Work. The connection to a reliable water source shall be completed prior to the
occupancy of the building or structure.

C. Temporary Water Source. The Director of Public Health is authorized to issue a permit for a
temporary water source not to exceed a maximum of one year from the date of occupancy. The temporary
permit is intended to be an interim measure while a reliable source of potable water is being obtained or
water lines constructed to the building site. A temporary permit shall not be issued unless the Director
of Public Health is presented sufficient evidence to indicate a reliable water source will be provided in
the extension period.

Section 10. Specific Procedures for the Surface Mine Waste Assessment Area.

A. Inspection Notification. After approval of an application for an Environmental
Health Certificate, the applicant shall notify the Director of Public Health when the site is complete
and ready for inspection. The Director of Public Health will either approve or deny the site remediation
in accordance with the requirements of Section 5.

B. Timing of Work. The inspection of the surface mine waste remediation shall be completed prior
to occupancy of the building or structure.

C. Re-inspection. The following measures shall be applied when the Director of Public Health
determines that the site remediation is not in compliance with the standards for site remediation.

(1) . The Director of Public Health shall provide written or verbal notice to the applicant that
the site remediation work failed to comply with the provisions of this resolution.

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(2). The applicant or responsible party shall be given adequate time to correct the deficiencies
and perform the work in accordance to the provisions of this resolution.

(3) . Upon completion of any additional site remediation, the applicant shall notify the Director
of Public Health, who shall conduct a re-inspection of the site-and either approve or deny
the remediation as meeting the requirements of Section 5.

(4). If the site remediation is denied, an Environmental Health Certificate shall not be issued
and the applicant shall have the right to appeal the decision of the Director of Public
Health in accordance with Section 14.

Section 11. Application Form of the Environmental Health Program

A. Application. One form shall be used to verify location within an assessment area and to issue
the Environmental Health Certificate. The form shall be furnished by the Director of Public Health.

(1) . Identify and describe the work to be covered by the Certificate.

(2) . Describe the land on which the proposed work is to be done by legal description and/or
street address, or by a similar description that will readily identify and definitely locate
the proposed building, structure or work.

(3). Verity if the proposed building or structure is located in the Surface Mine Waste Assessment
Area.

(4). Verify if the proposed building or structure is located in the Ground Water Assessment Area.

(5) . Identify the applicant/owner by name, address, and phone number.

(6). Identify the contractor by name, address, and phone number.

(7) . Indicate the use or occupancy for which the proposed work is intended.

(8) . Identify the source of authorized water supply, and verify submission of written
documentation from the authorized water supplier.

(9). Be signed by the Certificate applicant, or his or her agent.

Section 12. Stop Work Order.

Whenever any building or structure located within the Cherokee Superfund Site is under
construction without having first obtained the necessary Assessment Area Verification or an approved
application for an Environmental Health Certificate in compliance with the provisions of this resolution,
the Director of Public Health may order the persons engaged in doing or causing such construction
activity to stop until the necessary verification or application for a certificate is approved. The
Director of Public Health shall issue a written notice to the landowner or contractor and inform them of
the requirements of this Article. Only after failure to respond to the written notice, shall the
Director of Public Health post a "Stop Work Order" at the job site.

Section 13. Occupancy Violation.

Whenever any building or structure is occupied which is not in compliance with the provisions of
this resolution, the Director of Public Health may order such use discontinued and the structure vacated
until brought into compliance. The Director of Public Health shall serve written notice to the owner or
occupants. Such person shall discontinue the occupancy within the prescribed time by the Director of
Public Health after receipt of the notice to make the structure comply with the requirements of this
resolution. Failure to comply with the order to the Director of Public Health will be addressed in
accordance with the violation and enforcement provisions of Section 15.

Section 14. Appeals.

The County Commission is authorized to hear appeals regarding administration and interpretation of
this Article. Any interested party seeking an appeal shall file with the County Clerk a letter detailing
the reason for the request and subsequent evidence to warrant the justification of an appeal from the
provisions this Article. Said letter shall be submitted at least 10 days before the next regularly
scheduled meeting of the County Commission. The County Clerk shall schedule the appeal for hearing and
review by the County Commission.

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Section 15.  Violations and Enforcement.

       It shall be unlawful for any person to violate any of the provisions  of the Article.  The
provisions of K.S.A. 19-4701 through 19-4738 shall govern the practice and procedures for the enforcement
of this Article.

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ATTACHMENT 2

The Record of Decision (ROD) for Operable Units #03/#04, the Baxter Springs and Treece subsites,
of the Cherokee County, Kansas, Superfund site has been completed and is provided for your signature.
The state of Kansas and the local community concur with the selected remedy.

The Kansas Department of Health and Environment (KDHE) has actively participated in the
preparation and review of this document and has secured match funding, if ultimately necessary, for a
fund lead remedial action. Funding will initially be sought from responsible parties. Agency funds are
also available for remedy implementation if necessary.

The selected alternative is consistent with past actions conducted in the Tri-State Mining
District and compliments the actions taken by EPA Region VI at the contiguous Tar Creek Superfund Site in
Oklahoma. The remedy addresses surficial mining wastes in the Kansas portion of the Tri-State Mining
District and is estimated at approximately 7.1 million dollars. Early versions of this document were
modified pursuant to input by EPA Headguarters and EPA Region VI, in addition to the typical in-house
regional reviews.

If you have any guestions regarding this decision document, please contact me at extension 7664 or
Dave Drake, the project manager for this site, at extension 7626.

Attachment

cc: Larry Knoche, KDHE
Paul Nadeau, OSWER
Bonnie Gitlin, OSWER
Denise Jordan-Izaguirre, ATSDR
Noel Bennett, Region VI

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