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U.S. Environmental Protection Agency Region VIII November, 1998

Operable Unit 9 California Gulch Superfun d Site Leadville,

E PA Announces Its Preferred Alternative

Thi s Proposed Plan** describes the U.S. Environmental Protection Agency' s (EPA's) proposed

alternative for reducing health risks to residents

from lead in soils and other sources within Operable Unit 9 (OU9) of the California Gulch Superfund Site

in Leadville, Colorado. The Colorado Department of Public Health and Environment (CDPHE) has

participated in the decision-making process and

concurs with this alternative. This Plan is consistent

with on-going CERCLA activities at the site.

The preferred alternative consists of a multi-media

plan to reduce lead exposure to children from lead in

soil, dust, interior and exterior paint, leaded plumbing

fixtures, crafts and hobbies involving lead, and other

potential sources beyond an individual residence. T he preferred alternative will also include

community protective measures such as zoning and

deed restrictions, permitting, and other measures

developed with local community input.

The proposed alternative is a pilot by EPA. The

program will be reviewed periodically to ensure that

human health is being protected. This pilot is being

proposed in recognition of the unique climatic

conditions in Leadville, and the strong community

interest in managing exposure to lead.

MARK YOUR CALENDAR: OPPORTUNITIES FOR PUBLIC INVOLVEMENT

Public Meeting: Thursday November 19,1998

7:00pm Minin g Hall of Fame Leadville, Colorado

Public Comment Period: November 12,1998 - December 14,1998

Send Comments to: Rebecca Thomas EPA Project Manager

999 18* Street, Suite 500 Denver, Colorado 80202-2405

(303)312-6552 Toll-free (800) 227-8917 ext. 6552

Information Repositories: The Proposed Plan and other documents in the Administrative Record are available at the following locations: Lake County Public Library

1115 Harrison Avenue Leadville, CO 80461 Colorado Mountain College Library Learning Resource Center Leadville, CO 80461

E PA Superfun d Records Center

999 18* Street

5* Floor, North Terrace Denver, CO 80202

(303)312-6473

Rebecca Thomas

EPA Project Manager

999 18* Street, Suite 500 Denver, Colorado 80202-2405

(303)312-6552

K ey Contacts

Russ Alien CDPHE State Project Officer (303)692-3382

Marion Galant CDPHE Community Relations Coordinator Toll-free (888) 569-1831

** Words shown in bold italics are defined in the glossary at the end of the document.
TABLE OF CONTENTS

Preferred Alternative...........................page 1 Public Comment Period........................page 1 Public Involvement Process...................page 2 Site Background.................................page 2 Assessment of Site Risks......................page 3 Remedial Action Objectives..................page 4 Risk Management Approach..................page 4 Summary of Alternatives......................page 4 Cleanup Evaluation Criteria.....................page 7 Comparison of Alternatives...................page 7 Summary of the Preferred Alternative....... page 9 Acronyms.....................................................page9 Glossary.......................................................page9

The purpose of this Proposed Plan is to provide the*

public with information about the proposed

alternatives for OU9 and to solicit public input. This Proposed Plan was prepared to fulfill EPA's public

participation responsibilities under Sections 113(k)

and 117(a) of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) of 1980, as amended by the Superfund Amendments and Reauthorization Act (SARA) of

1986.

EPA encourages residents and other interested parties

to read and comment on this Proposed Plan and the Remedial Investigation/Feasibility Study (RI/FS) for OU9. These documents describe the OU9

contamination and the cleanup alternatives

considered. The Proposed Plan is based on the

findings of the RI/FS and other applicable documents. These reports are included in the Administrative Record for the California Gulch Superfund Site. The Administrative Record contains all of the information

upon which selection of an appropriate remedy will be

based.

The public is encouraged to comment on all identified

alternatives, as well as provide new information for

EPA to consider. Comments on the Proposed Plan can

be submitted either orally or in writing at the public

meeting on November 19,1998, or written comments

can be sent, to Rebecca Thomas at the address

provided on page I, postmarked not later than December 14, 1998. Upon timely request, the

comment period may be extended. Such requests

should be submitted in writing to Rebecca Thomas

and postmarked no later than December 14, 1998. After considering all comments, EPA will make its

final cleanup decision. EPA may modify the

preferred alternative, select another alternative

presented in this Proposed Plan, or select another

alternative based on new information or public

comments. The final cleanup decision will be

published in a Record of Decision (ROD) that

responds to all comments and documents EPA's

rationale for the selected remedy at OU9. ,

Site History. The California Gulch Site is located in

and around Leadville, Colorado, about 100 miles

southwest of Denver. Figure 1 is a general map of the California Gulch Site. As seen in Figure 2, OU9

encompasses both residential and open space areas

within the Site.

The Leadville area, including portions of OU9, was

the site of extensive mining, milling, and smelting

operations that began about 1860. Most mining

operations ceased around 1900, although some

facilitie s continued intermittent operations as late as

the 1960s. Most of the mines within the Site

boundary are presently inactive, and all of the mills

and smelters have been demolished.

Regulatory History. EPA placed the Site on the National Priorities List (NPL) in 1983 mainly due to

concern over the impact of mine drainage on surface

waters in the California Gulch and the Arkansas River. Subsequent site investigations revealed the presence

of heavy metals in soils and in waste piles in and

around the current residential area of Leadville. Based on a baseline human health risk assessment for residents at the Site (EPA 1996a, 1996b), EPA and

the State identified lead as the contaminant of

potential concern to human health (EPA 1996c). Other metals in the surface soils do not pose a significant

health risk to the residents (EPA 1996b).

Thi s response action is only one of several actions that

are planned or are currently underway to minimize

exposures and risks from lead contamination in

residential areas of Leadville. For example, certain

waste rock piles located in residential areas are being

removed to control exposures from direct contact and

to reduce ambient dust sources. In addition, a community-based program ("Kids First") was

implemented in 1995 to respond to requests from

concerned citizens to investigate and address

exposure to lead from a variety of potential sources,
including soil, dust, drinking water and paint. Other

activities include remediation of tailings and slag piles along with measures to improve surface water

quality.

During the Remedial Investigation/Feasibility Study (RI/FS), a baseline human health risk assessment was

conducted. Part A of this risk assessment (EPA

1996a) examined risks to residents from lead,

focusing specifically on risks to young children (age 0

to 6 years). Children were selected as the focus of this

risk assessment because children typically have

higher intake rates per unit body weight of

environmental media than adults, children tend to

absorb a higher fraction of ingested lead from the

gastrointestinal tract than do adults, and children tend

to be more susceptible to some of the adverse effect s

of lead than adults (especially impairment of the

nervous system).

Risk Assessment Approach for Lead. The risk

assessment for lead was supported by a large body of

site-specific data that included not only extensive

measurements of lead in soil and dust in residential

locations, but also an extensive demographics survey,

data on lead levels in water and paint (both interior

and exterior), data on the physical and chemical forms

of lead at various locations around the community,

and an informative community-wide blood lead study

involving 314 children (about 65% of the total

population of children at the site). These data were

used to support two parallel lines of investigation and

assessment The first of these employed EPA's Integrated Exposure Uptake and Biokinetic (IEUBK) model to calculate the expected impact of lead levels

in soil and dust on blood lead levels in area children. The second approach compared the measured blood

lead values in area children with relevant national

blood lead statistics in order to help evaluate the

current impacts of actual site exposures to lead.

Findings and Conclusions. The main findings of the

risk assessment for lead are summarized below:

1. In 1991, geometric mean blood lead levels in

children living within the site boundaries were

typically around 5-6 ug/dL, which was about 1-

1.5 ug/dL higher than reported geometric mean

values for children of similar age and sex living in

other areas across the nation.

2. In 1991, the site-wide frequency of children

exceeding EPA's health-based blood lead target of

10 ug/dL was about 8%, which is somewhat

higher than the target of no more than 5% above

10 ug/dL. This was indicative of a situation

which exceeded EPA's goal of no individual child

or group of similarly exposed children having a

greater than 5% chance of exceeding a blood lead

level of 10 ug/dL. In some sub-areas of the site,

the risk of exceeding 10 ug/dL appeared to be

substantially higher (10%-25%) than the sitewide average. Additional blood lead data

collected by county health agency from more than

100 children per year for each year between 1991

and the present suggests that the incidence of

children in the community with blood lead levels

above 10 ug/dL is continuing to fluctuate between

6%and9%.

3. There is a statistically significant correlation

between lead levels in soil and dust and blood lead

levels in children.

4. Both interior and exterior lead-based paint

contribute to risk of elevated blood lead levels in

some children, mainly by addin g to the

concentration of lead in soil and/or dust in those

homes where lead-based paint is a potential

source of lead exposure.

5. The results of the IEUBK model run using default

soil and dust ingestion rates predicted blood lead

levels that were higher than observed. It was

concluded that soil and dust ingestion rates in this

community were probably somewhat lower than

the national average values, possibly because the

ground is frozen or snow-covered approximately

eight months out of the year. Local effort s to

minimize lead exposure through an extensive

education and intervention program might also

explain some of the variation in predicted versus

currently observed blood lead levels.

6. Based on the analyses conducted, the risk

assessment reached the conclusion that soil lead

is a relatively minor source of exposure at

locations where lead levels were less man about

l,000ppm. Exposure via soil probably did not

become a dominant source of exposure until lead

levels were above 3,500 ppm. Other sources of

lead contributing to current exposure included

interior and exterior paint and indoor dust. Lead

levels in the water supplied by the municipal

water system are not of concern, but lead levels in
some shallow wells are high enough that it would

not be safe to use those wells as a routine source of

drinking water.

EPA guidance (EPA1994) states that EPA should:

...limit exposure to soil lead levels

such that a typica l (or

hypothetical[potentiall y exposed] )

child or group of similarly exposed

children would have an estimated risk

of no more than 5% of exceeding the

10 ng/dL blood lead level.

In accordance with this policy recommendation, the Remedial Action Objectives (RAOs) at this Site

agreed to in the 1994 Work Area Management Plan (U.S. District Court, 1994) are as follows:

• RAO-1: "No more than five percent of all children

(age 0 to 72 months) who live at this site, either now

or in the future, will have blood lead values higher

thanlOug/dL"

• RAO-2: "Health will be adequately protected if the

highest risk level at any sub-location is a probability

no higher than one percent that a population of

children (age 0 to 72 months) residing at that sublocation will exceed a blood lead value of IS

ug/dL."

Thi s second RAO is intended mainly to help guard

against potential exposures at sub-areas of the site

where lead exposures tend to be higher than average.

As noted above, the traditional approach used by EPA

to address the potential for elevated blood lead levels

in a community is to employ the IEUBK model to

predict the risk that children will have elevated blood

lead values from exposure to lead in soil, dust, food,

water and air. If the risk is above EPA's health-based

goal, soils are remediated such that remedial action

objectives are met If the default IEUBK model

inputs are used, this corresponds to a soil lead-action

level of about 400 ppm. If site-specific data and

inferences from Leadville are incorporated into the model, the soil action levels range from 1,100 -1,400.

ppm.

At this site, a non-traditional risk management ~

approach is being proposed. The objective is to

reduce childhood lead exposure by all identifiable

routes, including not only soil but also dust, water, and

paint, as well as other potential sources of exposure

both within and beyond an individual residence. Cleaning up residential locations where soil levels

exceed 3,500 ppm of lead, coupled with reductions in

exposure from other sources, will reduce the

probability of harmful exposure of children living in Leadville and surrounding residential areas and is

expected to help reduce the incidence of children with

blood lead levels higher than 10 ug/dL to a level that

meets or exceeds the RAOs. Actual or threatened releases of hazardous substances

from this site, if not addressed by the preferred

alternative or one of the other active measures

considered, may present an imminent and substantial

endangerment to public health, welfare, or the

environment

Seven differen t remedial alternatives were analyzed

for OU9 (ASARCO, 1996). A description of each of

these alternatives is provided below. In each case, 12

years of implementation was identified to simplify

cost comparison between alternatives. ALTERNATIVE 1: NOACTION.

Cost: $0 Years of Implementation: None

The Superfun d program requires that the "no action"

alternative be evaluated at every site to establish a baseline for comparison. Under this alternative, EPA would take no further action at the site to prevent

exposure to the soil contamination.

ALTERNATIVE 2: INSTITUTIONAL CONTROLS OR COMMUNIT Y PROTECTIV E MEASURES (CPMs)

Cost: $128,940 Years of Implementation: 12

Institutional Controls, or Community Protective Measures (CPMs) , may include zoning/deed

restrictions, permitting requirements, temporary

access restrictions, and community awareness

education. Deed restrictions could legally limit or

prohibit future land use in the source area. CPMs

alone may be appropriate and acceptable remedial
action alternatives for some residential area soils

source sites. This alternative may also be an element

of other alternatives; if so, temporary access

restriction such as fencing and posted warnings would

only be used to physically control access to the

residential area soils during construction activities.

combined with containment of both surface water and

source surfaces. Surface water control may be

implemented through diversion ditches and culverts

as discussed in Alternative 3. The source surface

control element of containment involves in situ

mixing, revegetation, or a soil cover as discussed in Alternative 4.

ALTERNATIVE 3: CONTAINMENT (SURFACE WATER CONTROLXCPMs Cost: $619,200 Years of Implementation: 12

Alternative 3 for the residential area soils includes the CPMs described in Alternative 2 combined with

surface water containment. The containment

component of this alternative includes surface water

control methods such as diversion ditches and

culverts. The diversion ditches would be constructed

to divert surface water flow and run-off away from

and around the source areas. Covered culverts would

be constructed to conduct surface water flow through

more populated areas. These controls would reduce

the potential for transport of metals away from the

source area and, therefore, reduce metals impacts to

surface water or other areas.

ALTERNATIVE 4: CONTAINMENT (SOURCE SURFACE CONTROL)/CPMS

Cost: $1,176,860 Years of Implementation: 12

This alternative includes the CPMs described in Alternative 2 combined with methods for source

surface containment. The containment component of

this alternative would be based on source surface

control options including soil covers, in situ mixing,

and revegetation. Soil cover involves adding

additional fill to isolate the impacted surface soil. In

situ mixing involves tillin g surface soil with deeper

soil. Revegetation involves planting appropriate

cover vegetation to lessen infiltration , leaching, and

erosion.

ALTERNATIVE 5: CONTAINMENT (SURFACE WATER CONTROL , SOURC E SURFAC E CONTROLVCPMS

Cost: $1,599,670 Years of Implementation: 12

Alternative 5 for the residential area soils sources

includes the CPMs described in Alternative 2

ALTERNATIVE 6: REMOVAL/TRANSPORTATION/

DISPOSAL/ CPMS Cost: $6,311,650 Years of Implementation: 12

This alternative includes the CPMs described in Alternative 2 combined with removal, transport, and

disposal of residential area soils where mean lead

levels are greater than 3,500 ppm. The residential

area soils would be excavated by hand with the aid of

small conventional earth-moving equipment and

replaced with clean fill. Excavated materials would

be hauled by truck to an on-site repository,

consolidated in an existing on-site tailings pile, or

removed to some other designated area.

ALTERNATIVE 7: LAKE COUNT Y COMMUNIT Y HEALTH PROGRAM (EPA' s preferred alternative')

Cost: $4,758,000 Years of Implementation: 12, or until Remedial Action Objectives (RAOs) are

achieved

Alternative 7 consists of the implementation of the Lake County Community Health Program (LCCHP). The program is a multi-media plan to reduce lead

exposure to children in Leadville and surrounding

areas. Potential sources that would be considered

include not only soil and dust, but also interior and

exterior paint, leaded plumbing fixtures, crafts and

hobbies involving lead, and other potential sources

beyond an individual residence. Alternative 7 may

also include community protective measures such as

zoning and deed restrictions, permitting, and other

measures developed with local community input. The

key components of the LCCHP are as follows:

• Residential property owners within OU9 may

request an investigation of lead levels in soil,

dust, paint and water on the property (if such an

investigation has not already been performed).

• Continued voluntary blood lead monitoring

(with financial incentives) for all children age 6-
72 months and voluntary blood lead monitoring

for pregnant and nursing women.

• If the concentration of lead in blood of an

individual or in one or more of the

environmental media at a residence exceeds a specified set of "trigger criteria", then

appropriate actions will be taken to address the

exceedance. These trigger criteria are

summarized below:

Blood Lead >10ug/dL Soil Lead concentration above 3,500 ppm Dust Indoor dust lead concentration

greater than 2,000 ppm Paint Interior or exterior paint with lead

levels above 1 mg/cm1 and in poor

condition Water Lead in drinking water above 15ug/L

• When one or more of the trigger criteria are

exceeded, a range of differen t response actions

may be considered. The most appropriate

response actions will be determined by the nature

and extent of the exceedance, the effectiveness in

risk reduction, implementability, impact on

cultural resources, property owner acceptance,

cost-effectiveness, and community impacts. Any

response action will be conducted to meet the

needs of the property owner. An extensive

education and intervention program to manage

lead exposure at the site will be an integral

component of each action considered. Soil

remediation will be offered at all residences where

soil lead levels exceed 3,500 ppm. Soil

remediation may occur if soils are between 1,100

and 3,500 ppm in response to an elevated blood

lead. Any excavated soils will be managed and

disposed of properly. The options for each

medium are listed below.

Blood Lead

- Investigation and remediation of potential

exposure sources, including those above

and others (as needed)

- Continued blood lead monitoring

- Education

- Medical follow-up, as appropriate

Soil

- Containment (sod placement, capping with

soil, clay, asphalt or cement)

- Removal to an on-site repository and

replacement with clean soil

- Institutional controls . ' ' Dust

- Physical measure (sealing off dust source

areas)

- Removal (vacuum, mopping, duct

cleaning, mats)

Paint

- Containment and covering (enclosure,

encapsulation, stabilization in place)

- Removal (scraping, stripping, disposal offsite)

- Institutional controls (disclosure, controls

during renovation activities)

Drinking Water

- Point-of-use treatment system

- Alternative water supply

- Replacement of lead containing pipes,

joints of fixtures

- Institutional controls (restrictions on

groundwater use)

Since the LCCHP is a "pilot project" that involves

a number of innovative approaches, it includes

ongoing review (rather than waiting for the

typical five-year review) to ensure that the

program is operating as intended and that human

health is being adequately protected. Any

problems with the program will be identified and

adjusted as necessary. Key components of the

review process are as follows:

- Periodic checking to ensure adequate

participation of area residents in the blood

lead monitoring and environmental media

sampling programs.

- Special effort to ensure collection of

paired blood lead and environmental lead

data whenever possible

Creation and application of a welldocumented quality assurance plan to

ensure that blood lead and environmental

lead data are collected and analyzed in the

proper manner, and that the data are

accurately entered into an ongoing

database suitable for scientific evaluation.

- Periodic evaluation of the program by a

group of outside scientists.
- Annual reporting of summary statistics and

comparison to Remedial Actio n Objectives.

As described in the next sections, these alternatives

were compared and evaluated using EPA's nine

evaluation criteria established in the National Contingency Plan (NCP).

These seven alternatives were evaluated in detail

using the criteria summarized below. The first two

evaluation cleanup criteria, overall protection of

human health and the environment, and compliance

with Applicable or Relevant and Appropriate Requirements (ARARs), are threshold criteria that

must be met by the selected remedial action. The next

five criteria are considered primary balancing criteria. The final two criteria, State and community

acceptance, are modifyin g criteria which the EPA evaluates and incorporates before making the final

clean-up decision.

Based on a careful review of each of the alternatives,

EPA and the State have identified Alternative 7, Lake County Community Health Program as the proposed

alternative for remediation of the residential soils

(OU9) at the California Gulch Site. Based on current

information, this alternative best achieves a balance

among the nine criteria that EPA uses to evaluate

alternatives with the understanding that this is a pilot

approach that will be evaluated on a continuing basis. The followin g section of the Proposed Plan compares

the proposed alternative and the other alternatives to

the nine evaluation criteria.

Overall Protection of Human Health and the

Environment Alternative 7 will provide the most comprehensive

protection of human health and the environment from

lead, since it addresses not only lead in soil but also

lead in other sources such as dust, paint and drinking

water. Alternatives 5 and 6 provide less protection

since they do not address all lead sources.

N CP Evaluation Criteria

•Overall protection of human health and the environment addresses whether or not a remedy provides adequate

protection and describes how risks posed through each pathway are elim inated, reduced, or controlled.

•Compliance with ARARs addresses whether or not a remedy will meet all Federal and State environmental laws

and/or provide grounds for a waiver.

•Long-term-effectiveness and permanence refers to the ability of a remedy to provide reliable protection of human

health and the environment overtime.

•Reduction of toxicity. mobility , or volume through treatment refers to the preference for a remedy that reduces health

hazards, the movement of contam inants, or the quantity of contaminants at the site through treatment.

•Short-term effectivenes s addresses the period of time needed to complete the remedy and any adverse effect s to

human health and the environment that may be caused during the construction and implementation of the remedy.

•Implementabilit y refers to the technical and administrative feasibilit y of the remedy, includin g the availability of materials and services needed to carry out the remedy and coordination of Federal , State, and local governments to

work together to clean up the site.

•Cost evaluates the estimated capital and operation and maintenance costs of each alternative in comparison to other

equally protective measures.

•State acceptance indicates whether the State agrees with, opposes, or has no comment on the preferred alternative.

•Community acceptance includes determining which components of the alternatives interested persons in the

community support, have reservations about, or oppose.
Alternatives 3 and 4 provide fair protection, while Alternatives 1 and 2 provide poor to no protection.

Compliance with ARARs Applicable requirements are defined by the NCP as

those cleanup standards, standards of control, and

other substantive environmental protection

requirements, criteria, or limitations promulgated

under federal or state law that specifically address a hazardous substance, pollutant , contaminant,

remedial action, location, or other circumstances at a

site. It should be noted that while a requirement may

not be applicable as a matter of law, a requirement

may still be "relevant and appropriate" if it regulates

or addresses problems or situations sufficientl y

similar to those encountered at the subject site that its

use is well-suited to the particular site. ARARs are

grouped into three categories: chemical-specific,

action-specific and location-specific. Alternatives 1

and 2 do not comply with ARARs; Alternatives 3 and

4 would only comply with some ARARs, while Alternatives 5, 6, and 7 would comply with all ARARs.

Long-Term Effectivenes s and Permanence Alternative 1 does not reduce residential risk, while Alternative 2 could be somewhat effective by

controlling/limiting future use. Alternatives 3,4, and

5 provide a moderate degree of long-term

effectiveness, but recontamination is likely and these

alternatives do riot address all lead sources. Alternative 6 would provide the highest degree of

long-term effectiveness and permanence for soils;

however, it does not address other potential lead

sources and might require long-term operation and

maintenance of an on-site repository. Alternative 7 would provide long-term effectiveness for many lead

sources, but could in some cases use remedies whose

efficacy could decrease with time (e.g., sodding,

house cleaning, painting).

Reduction of Toxicitv. Mobility, or Volume Through Treatment None of the alternatives reduce Toxicity, Mobility, or Volume through treatment.

Short Term Effectiveness Alternative 1 has no short-term effectiveness. Alternative 2 could have some short-term

effectiveness by controlling use of some source areas. Alternative 3 could have good short-term

effectiveness in reducing the potential for surface

T f water impacts. Alternatives 4,5, and 6 would not be

effective in the short-term due to the fact that

excavation would disturb soils and vegetation which

may take several years to re-establish. Alternative 7 would have the greatest short-term overall

effectiveness by prioritizing intervention and

remediation in cases of children with elevated blood

lead levels, coupled with proactive identification and

abatement of die most significant sources of lead

exposure in residential areas.

Implementabilitv Alternative 1 does not require implementation. CPMs (Alternative 2) would be easy to implement;

however, the administrative aspects such as deed

restrictions could pose difficulties in enforcement Alternative 3 would be relatively simple to implement

since most of the surface water controls could be

implemented on public land or easements. Alternatives 4 and 5 would be relatively easy to

implement except for access and space limitations. Alternative 6 would be difficul t to implement due to

space constrictions in most residential yards and due

to the need for locating a repository prior to

implementation of the alternative. Alternative 7 could be more easily implemented because the

framework for the Lake County Community Health Program (LCCHP) is currently in place and the

implementation would be an extension of the current Kids First Program.

Cost Alternative 1 has no associated cost. Alternatives 2

and 3 have a relatively low cost, but do not satisfy the

remedial objectives. Alternatives 4 and 5 are moderately priced, but do not satisfy the remedial

objectives. Alternative 6 is the highest cost

alternative, but does not address all the sources of

lead. Alternative 7 would satisfy the remedial

objectives at a moderate cost as compared to other

alternatives.

Support Agency Acceptance The Colorado Department of Public Health and the Environment (CDPHE) would be unlikely to accept Alternatives 1 through 4, since they do not provide

adequate protection of human health and the

environment. Alternatives 5 and 6 may be acceptable

because lead from residential soils would be

effectively controlled. The CDPHE has participated

in the decision-making process and concurs with the

implementation of Alternative 7 since residential
soils &nd additional sources of lead would be

controlled.

Community Acceptance Community acceptance of the preferred alternative

will be evaluated after the public comment period

ends and will be described in the Record of Decision

(ROD) for the site. However, Alternative 7 (LCCHP) has the support of Lake County public

health official s and the CDPHE, as well as elected

representatives from both the City of Leadville and Lake County. Community participation in, and

strong support for, the Kids First Program (which is

similar to the proposed alternative) also indicates

community acceptance.

rag/cm* milligrams per cubic centimeter . fig/dL micrograms per deciliter mg/cm1

 milligrams per square centimeter

In summary, Alternative 7 would achieve substantial

risk reduction from lead exposure through

remediation of residential soils and other sources of

lead. Alternative 7 can quickly achieve this risk

reduction at a relative moderate cost. The preferred

alternative would be protective of human health and

the environment and best meets the other evaluation

criteria. Because it is a pilot program, the

effectiveness of the alternative would be carefully monitored over time.

ARARs Applicable or Relevant and Appropriate Requirements CDPHE Colorado Department of Public Health

and Environment CERCLA Comprehensive, Environmental Response, Compensation, and Liabilit y Act of 1980 CPMs Community Protective Measures E PA U.S. Environmental Protection Agency FS Feasibilit y Study IEUBK Integrated Exposure Uptake and Biokinetic model LCCHP Lake County Community Health Program N CP National Contingency Plan N PL National Priorities List OU9 Operable Unit 9 R AO Remedial Action Objective RI Remedial Investigation ROD Record of Decision SARA Superfun d Amendments and Reauthorization Act of 1986

p pm parts per millio n

Administrative Record: The body of documents EPA

uses to form the basis of selection of a response.

Alternative: An option for reducing site risk by

cleaning up or otherwise limitin g exposure to

contamination.

Applicable or Relevant and Appropriate Requirements: Federal and state requirements for

cleanup, control, and environmental protection that a selected remedy for a site will meet.

Capital Costs: Expenses related to the labor, equipment

and material costs of construction.

Comprehensive Environmental Response, Compensation, and Liability Act: A federal law

passed in 1980 and modified in 1986 by the Superfun d Amendments and Reauthorization Act. It sets up a

program to identif y sites where hazardous substance

have been, or might be, released into the environment

and to ensure they are cleaned up. Most of these sites

are abandoned or are no longer active.

Feasibilit y Study: The FS identifies and evaluates

the most appropriate technical approaches to

address contamination problems at a Superfund site.

Human Health Risk Assessment: A study used by

EPA to evaluate risks posed by a Superfund site if

no actions are taken to protect human health.

National Contingency Plan: The EPA' s

regulations governing all cleanups under the Superfun d program.

National Priorities List: EPA's list of the most

serious uncontrolled or abandoned hazardous waste

sites identified for possible long-term remedial

response.

Operation and Maintenance: The cost and

timeframe of operating labor, maintenance,

materials, energy, disposal, and administrative

activities of the remedy.

Proposed Plan: A document requesting public

input on a proposed remedial alternative.
Record of Decision: A document which is a consolidated source of information about the site,

the remedy selection process, and the selected

remedy for a cleanup under CERCLA.

Remedial Action Objectives: Medium-specific

(e.g. groundwater, tailings) goals for protecting

human health and the environment

Remedial Investigation: A study conducted to

identify the types, amounts, and locations of

contamination at a facility. It also evaluates

possible risk to public health and the environment

from exposure to contamination. \

Slag: The solid non-metallic glass-like byproduct

formed in a blast furnace or smelter when melting metals or reducing ores.

Superfun d Amendments and Reauthorization Act: Modifications to CERCLA enacted on October 17,1986.

Tailings: The portion of mineral ores that is

separated out during the milling of ore and

disposed.

ASARCO, 1996. Draft Residential Soil s Feasibility Study, California Gulch Superfund Site, Leadville, Colorado. Prepared by Colder Associates.

Environmental Protection Agency (EPA). 1995. U.S. Environmental Protection Agency, National Center for Environmental Assessment. Urban Soi l Lead Abatement Demonstration Project Review Draft. EPA/600/R-95/139.

Environmental Protection Agency (EPA). 1996a. Baseline Human Health Risk Assessment California Gulch Superfund Site, Leadville, Colorado, Part A- Risks to Residents from Lead. Prepared by Roy F. Weston, Inc. January.

Environmental Protection Agency (EPA). 1996b. Baseline Human Health Risk Assessment, California Gulch Superfun d Site, Leadville, Colorado, Part B - Risks to Residents from Contaminants Other than Lead. Prepared by Roy F. Weston, Inc. January.

Environmental Protection Agency (EPA). 1996c. Draft EPA Fund-Lead Project Plan, California Gulch Superfund Site,. Prepared by U.S. Bureau of Reclamation. February.

10
California Gulch Superfnn d Site Operable Unit 9

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California Gulch Superfund Site Leadvilla, Colorado Transportation and Cultural Features Hydrography

Operable Unit Boundary RI/FS Study Area Boundary