ELIZABETH MINE SITE PUBLIC HEARING PRESENTATION … · PROPOSED PLAN FOR EARLY CLEANUP ACTION...

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ELIZABETH MINE SITE

PUBLIC HEARING

REGARDING

PROPOSED PLAN

FOR

EARLY CLEANUP ACTION (NTCRA)

APRIL 10, 2002

Site Description

Elizabeth Mine Site is located on Thetford/Strafford Town Line

Site has been determined to be eligible for the National Register of Historic Places

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o Copperas production in TP-3 area from about 1810 to 1880s

o Copper production from 1830s to 1958

Elizabeth Mine NTCRA Public Hearing April 10, 2002

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Site Description

Six distinct source areas:

o Three areas of waste rock, tailings, and heap leach piles

• TP-1 - 30 acres of tailings • TP-2 - 5 acres of tailings • TP-3 - 12 acres of waste rock and heap

leach piles

o Areas of excavated bedrock (North Open Cut and South Open Cut)

o Underground workings

o South Mine

The three tailings, waste rock, and heap leach piles (TP-1, TP-2, and TP-3) are the subject of the early cleanup action

Elizabeth Mine NTCRA Public Hearing April 10,2002

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Community Involvement

Concern with EPA's involvement lead to formation of the Elizabeth Mine Community Advisory Group (EMCAG)

EMCAG, EPA, and VT ANR have been meeting regularly since April 2000

The community involvement process included the development of five initial documents for review by the EMCAG and its consultants

o Site Summary Report (Oct. 2000) o Site Conditions Report (Feb. 2001) o Alternatives Analysis Report (April 2001) o Preliminary Human Health and Ecological Risk

Evaluation (July 2001) o Draft Engineering Evaluation and Cost

Analysis (EE/CA) (September 2001)

EMCAG comments regarding the five report and feedback during the EMCAG monthly meetings shaped the development of the final EE/CA


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Community Involvement

EPA has made every effort to adjust the cleanup alternatives based on the input from the community

EPA provided funding to the community for independent experts to review documents through the Technical Outreach Services to Communities (TOSC) and Technical Assistance Grant (TAG) programs

EPA awarded the communities of Strafford and Thetford a Redevelopment Initiative Grant to hire experts to evaluate future uses of the Site

June 2001 comment letter from EMCAG regarding draft Alternatives Analysis Report was used to develop draft Engineering Evaluation and Cost Analysis (EE/CA)

November 2001 comment letter from EMCAG regarding draft EE/CA stated that nine of the ten EMCAG groups supported the alternatives EPA considered in the EE/CA


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Impacts from Mine

EPA investigations confirmed previous studies by VT ANR, US ACE, USGS, and EMSG

The entire length of Copperas Brook and a five mile stretch of the WBOR fail VT Water Quality Standards (VT WQS) for both the numerical and biological criteria

Copperas Brook and the first mile of the WBOR have significantly reduced fish and benthic populations

Surface water in Copperas Brook and first few hundred yards of WBOR after Copperas Brook are highly toxic to fish and benthic organisms


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Impacts from Mine

Aluminum (201), cobalt (9), copper (63), iron (50), manganese (17), and zinc (1) are the contaminants detected above VT WQS and EPA criteria in the WBOR

A comparison to VT WQS for biological measures (invertebrates and fish populations) indicates that the WBOR is of good quality above Copperas Brook even though iron (5) was detected above VT WQS and aluminum (42) and manganese (6) were detected above EPA reference criteria upstream of mine in WBOR

Cobalt, copper, and zinc were not detected above VT WQS or EPA reference criteria upstream of Copperas Brook

Concentrations for aluminum, iron, and manganese were significantly higher in the WBOR downstream of the Copperas Brook-WBOR confluence

Alkalinity of WBOR neutralizes the acidity contributed by Copperas Brook, therefore toxic effects in WBOR are attributed to the metals as opposed to the acidity


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Cleanup Approach

Acid mine drainage (AMD) from tailings, waste rock, and heap leach piles within Copperas Brook drainage has been identified as the major source of the impact to the WBOR and Copperas Brook

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The significant impacts to Copperas Brook and the WBOR support the need for an early cleanup action at the Site

EPA often uses the Non-Time-Critical Removal Authority (NTCRA) to initiate an early cleanup prior to the completion of the comprehensive site investigation

EPA has initiated hundreds of NTCRA's (about 287), including over 40 at mining sites

EPA has developed an Engineering Evaluation and Cost Analysis (EE/CA) in support of the NTCRA


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Cleanup Objectives

EPA developed a set of objectives for the early cleanup:

• Achieve VT Water Quality Standards (chemical and biological) as well as other applicable standards in the WBOR by preventing or minimizing discharge of water with mine-related metals contamination to Copperas Brook and the WBOR;

• Minimize the erosion and transport of tailings or contaminated soil into the surface waters of Copperas Brook and the WBOR;

• Evaluate stability of waste piles (tailings, waste rock, and leach piles) and modify slope configurations (re-grading, covering or buttressing) as necessary to provide for an acceptable level of long-term stability;

• Consider measures to minimize and avoid an adverse effect on historic resources at the Site, as required by the National Historic Preservation Act; and

• Comply with all applicable federal and state regulations.

In addition to protection of human health, Superfund's goal is to:

• reduce ecological risks to levels that will result in the recovery and maintenance of healthy local populations and communities of biota


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Alternative Evaluation

• EPA used three criteria to evaluate the five alternatives presented in the EE/CA:

1. Effectiveness

-Overall protection of human health and the environment -Compliance with federal and state laws and regulations (ARARs) and other criteria, advisories, and guidance -Long-term effectiveness and permanence -Reduction in toxicity, mobility, or volume through treatment -Short-term effectiveness

2. Implementability

-Technical feasibility -Administrative feasibility -Availability of services and materials -State and community acceptance

3. Cost

- Both direct and indirect capital costs

The State and Community Acceptance criterion will be evaluated following the public comment period

Elizabeth Mine NTCRA Public Hearing April 10,2002 of21

EPA Proposes Alternative 2C

After evaluating the five cleanup alternatives presented in the EE/CA, EPA believes that Alternative 2C represents the best balance of cost, effectiveness, and implementability.

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Components of Alternative 2C:

1. Surface water and groundwater diversion to intercept clean water and move this water around the tailings

2. Slope stabilization, as determined necessary by geotechnical design studies

3. Infiltration barrier cover system over top (nonslope) areas of TP-1 and TP-2

• Soil layer for vegetation • Drainage layer • Barrier layer (geomembrane with possible

geosynthetic clay liner)

Elizabeth Mine NTCRA Public Hearing April 10, 2002 of 21


4. Collection and treatment of water that discharges atthetoeofTP-1

• Anoxic limestone drain • Holding pond to stabilize flow • Anaerobic bioreactor • Aerobic wetlands

5. Collection and treatment of run-off from TP-3

• Holding pond to stabilize flow • Lime application system (Semi-Active

Alkalinity Dosing System) • Anaerobic Bioreactor • Aerobic wetlands

Elizabeth Mine NTCRA Public Hearing April 10,2002 of 21


6. Preservation of TP-3

• TP-3 is the most significant source of contamination at the site

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• Three options presented for the preservation of the historic heap leach piles and waste rock

• Final decision will be made after the design studies allow for a revised cost estimate for the maintenance of TP-3 (maintenance will be performed by State of VT)

• Complete removal of TP-3 is possible if no funding is available for maintenance



7. Cost

• Capital costs are dependent upon the volume of TP-3 that is preserved o $14.2 for Option 2 (preservation of about

50% of TP-3) o $15.4 for Option 3 (preservation of about

20% of TP-3) o $12.9 for Option 1 (preservation of 100% of

TP-3) • Maintenance Costs (obligation of State of VT)

o $90,000 per year for cover system and TP-1 passive treatment system

o $153,000-$200,000 per year for TP-3 maintenance system - Option 2 or 3 (50% or 20% preservation)

o $254,000 - $400,000 per year for TP-3 maintenance - Option 1 (100% preservation)

o Note: Low end cost assumes sludge and solids generated by treatment systems will be a non-hazardous solid waste, high end assumes that the material is a hazardous waste

Elizabeth Mine NTCRA Public Hearing April 10, 2002 of 21


EPA also seeks public comment with respect to:

• Unavoidable impacts to wetlands and floodplains

• Unavoidable impacts to historic resources eligible for the National Register of Historic Places

• Findings with respect to the Vermont Solid Waste Management Rules

o These findings support the alternative measures that have been approved by EPA to allow TP-3 to remain uncovered and for greater design flexibility with respect to the cover system and slopes of TP-1 and TP-2


Public Comment Process

Public comment period opened March 15, 2002 and will close April 15, 2002

Three ways to comment:

o Submit written comment to EPA postmarked no later than April 15, 2002 to:

Edward Hathaway EPA Region 1

Suite 1100 (HBT) 1 Congress Street

Boston, MA 02114-2023 fax (617) 918-1291

o Send email comment to: [email protected]

o Read your comment into the public record tonight


mailto:[email protected]


Public Hearing: A stenographer is present to record comments spoken tonight

o EPA will limit the time for each comment to five minutes to allow all individuals an opportunity to comment

o EPA does not respond to comments during the public hearing to provide all individuals with an opportunity to speak their comments into the record

• After the comment period. EPA will prepare a response to the comments received (written, email, or spoken) as part of the Action Memorandum in a Response to Comments document

Elizabeth Mine NTCRA Public Hearing April 10, 2002 of21


The EE/CA, Proposed Plan, and other documents that comprise the Administrative Record are available for review at the EPA Record Center at 1 Congress Street, Boston, MA and the Norwich Public Library

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Many of the Site documents are also available at the epa.gov/region1 /superfund/index2 .htm website. Click on "Find New England Sites" and the type "Elizabeth Mine" in the box and then click on the "Elizabeth Mine"


Next Steps

EPA will evaluate public and state comments and develop an Action Memorandum that documents the selection of the cleanup action

EPA will seek funding for Design of NTCRA *

NTCRA design and associated investigations/pilot studies may require 1-2 years

Memorandum of Agreement for impacts to historic resources will be developed during Design

Cleanup could begin in 2004 if funding is available, phased approach is possible

EPA expects to complete the investigation of the Site during 2002 and 2003

Final cleanup proposal scheduled for 2003/2004


Summary

EPA is proposing Alternative 2C as the best balance of:

• environmental protection • cost effectiveness • minimization of long-term costs and impacts

on historic resources • reduction in truck traffic • compliance with applicable regulations

EPA is seeking public comment regarding:

o Alternative 2C o Findings with respect to the VT SWMR o Notification regarding unavoidable impacts to

wetlands, floodplains, and historic resources

EPA would like to acknowledge and express appreciation for the hard work and dedication of the members of the EMCAG (including TAG group (CHC)), and VT ANR in working with EPA for the past two years


Summary

The cleanup has been significantly influenced by the input from the EMCAG

Major objectives of the design for the cleanup will be to: o Develop the most cost-effective approach to

implement the cleanup and meet the cleanup objectives (may include phasing)

o Minimize re-grading to reduce costs and to maintain the historic profile of tailings

o Pilot testing of passive treatment systems to improve cost estimate for maintenance

o Modeling to estimate the long-term flow from the seeps of TP-1

o Sampling to estimate the contaminant loading from the portion of TP-3 to be preserved

o Minimize the truck volume on public roads (seek to develop alternate routes and sources of material adjacent to the Site)

o Determine the optimum scheduling approach/phasing


ELIZABETH MINE SITE PUBLIC HEARING PRESENTATION … · PROPOSED PLAN FOR EARLY CLEANUP ACTION...

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