PUBLIC INFORMATION MEETING PRESENTATION: … · EPA investigations confirmed previous studie bsy VT ANR, USAGE, ... active (waste water treatment plant o)r passive (biological system

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ELIZABETH MINE SITE

PUBLIC INFORMATION MEETING

PROPOSED PLAN

FOR

EARLY CLEANUP ACTION (NTCRA)

MARCH 2002

Site Description

Elizabeth Mine is located on Thetford/Strafford Town Line

Includes 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

Most of the mine waste is located in the Copperas Brook and Lord Brook watersheds

Copperas Brook and Lord Brook drain into the West Branch of the Ompompanoosuc River (WBOR)

Elizabeth Mine NTCRA Public Information Meeting March 2002 Page 2 of 37

Environmental History

Site identified by VT ANR and U.S. Army Corps of Engineers as source of pollution during 1970's and 1980's

USGS and Elizabeth Mine Study Group performed studies at Site in 1990's

VT ANR requested EPA involvement in 1999

EPA kick-off meeting in February 2000


Historical Significance

• Copperas production in TP-3 area from about 1810 to t'880's

• Copper production from 1830's to 1958

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

• Site historical significance is documented in two Reports:

O Statement of Site Limits, National Register Eligibility, and Potential Resources in Proposed APE: Elizabeth Mine (October 2000)

O Historic Context and Preliminary Resource Evaluation of the Elizabeth Mine (May 2001)


Community Involvement

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

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

Cleanup proposal was developed through an interactive dialogue with the community

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)


Community Involvement

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

EPA provided the community with technical resources 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 in evaluating future uses of the Site

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


Impacts from Mine

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

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

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


Impacts from Mine

Aluminum, cobalt, copper, iron, manganese, and zinc were identified as the most significant contaminants of concern (See Table)

These metals were detected well above VT WQS and EPA criteria:

Comparison of Concentration to Standards Contaminant of Upstream of Downstream of Copperas Concern Copperas Brook Copperas Brook in Brook

inWBOR WBOR

Aluminum 42 201* 1540 Cobalt 0.8 9 770 Copper 1 63 2210 Iron 5 50 492 Manganese Zinc

6 0.1

17 1

64 30

* Each value represents the extent to which the maximum concentration exceeded VT WQS or EPA criteria. Aluminum at 201 means that the level was 201 times the VT WQS or EPA criteria


Impacts from Mine

Aluminum, iron, and manganese were detected above VT WQS upstream of mine in WBOR but much higher concentrations were found in Copperas Brook and below 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

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 metals contamination


Cleanup Approach

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

Elizabeth Mine NTCRA Public Information Meeting March 2002

Page 10 of 37

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. "Ecological Risk Assessment and Risk Management Principles for Superfund Sites", OSWER Directive 9285.7-28P, October 1999


Page 11 of 37

Acid Mine Drainage Technologies

EPA evaluated a range of technologies for controlling and/or treating acid mine drainage in the Alternatives Analysis Report (April 2001)

Fundamental approaches to acid mine drainage cleanup are to either:

o Prevent acid generating waste from coming into contact with water and oxygen (Source Control); or

o Collect and treat the acid mine drainage using active (waste water treatment plant) or passive (biological systems with no major mechanical components) approaches (Treatment)

Source control is the preferred approach by regulatory agencies and mining experts


Page 12 of 37


Source Control

o Submergence (keep tailings/waste rock under water)

O Cover

• Soil cover may be sufficient in dry climates due to low precipitation

• Infiltration barriers or evapotranspiration covers are needed for areas like Vermont with significant precipitation

• Low permeability soils • Geosynthetic materials (clay

blankets or geomembranes) • Combination of these (composite

liner)


Page 13 of 37


Collection and treatment of AMD is typically used to address residual drainage after source control or for areas where source control is not practical

Three of the most prevalent natural system approaches for treatment are:

1. Passive pH adjustments

2. Anaerobic wetlands

3. Aerobic wetlands


Page 14 of 37

Cleanup Alternatives

A combination of source control and treatment technologies were assembled to create five cleanup alternatives for evaluation in the EE/CA

All Alternatives include these baseline items:

• Preservation of a portion of TP-3 (up to 100%, exact amount to be determined by VT ANR and SHPO)

• Diversion of surface water away from TP-1 and TP-2

• Collection of storm water runoff and drainage from TP-3 and treatment with passive systems

• Collection of drainage from toe of TP-1 and treatment with passive systems

• Stabilization of the steep slope areas of TP-1 and TP-2, as necessary, and

• Backfilling/stabilization of decant pipe


Page 15 of 37


Alternative 2B (Geomembrane Cap with TP-2 removal)

• Consolidation of TP-2 into the footprint of TP-1 • Placement of an infiltration barrier cover system over

consolidated TP-1 • Placement of soil and a drainage layer to protect the infiltration

barrier and promote vegetation (grass)

Alternative 2C (Geomembrane Cap)

• Consolidation of a small portion of TP-2 onto TP-1 • Minor re-shaping of TP-1 and TP-2 • Placement of an infiltration barrier cover system over TP-1 and

TP-2 • Placement of soil and a drainage layer to protect the infiltration

barrier and promote vegetation (grass)

Alternative 3B (Evapotranspiration Soil Cover)

• Consolidation of a small portion of TP-2 onto TP-1 • Minor re-shaping of TP- l/TP-2 • Placement of a 42 inch thick soil cover over TP-1 and TP-2 to

reduce infiltration by means of evaporation and plant use (bottom 18 inches will be infiltration barrier)


Page 16 of 37


Alternative 3C (Soil Cover)

• Consolidation of a small portion of TP-2 onto TP-1 • Minor re-shaping of TP- l/TP-2 • Placement of six inches of soil over the surface of TP-1 and TP

2 that will support long-term vegetation (not an infiltration barrier)

Alternative 3D (Hardpan Barrier Layer)

• Consolidation of a small portion of TP-2 onto TP-1 • Minor re-shaping of TP- l/TP-2 • Mixture of lime and/or crushed limestone into the tailings to

form a chemical cap to encapsulate TP-1 and TP-2 • Placement of 18 inches of soil to promote a long-term

vegetative cover • Placement of a drainage net beneath the soil to prevent ponding

of water above the hardpan layer


Page 17 of 37

Alternative Evaluation

• EPA used three criteria to evaluate the alternatives:

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


Page 18 of 37


All five alternatives would protect human health and the environment

Maintenance of the cover system and passive treatment system is critical to long-term effectiveness of the Alternatives

Alternatives 2B, 2C, and 3B are designed to minimize the long term maintenance costs associated with TP-1 and TP-3

Passive treatment system for TP-3 will require greater maintenance than the system for TP-1 due to complex chemistry and high concentrations of contaminants in TP-3


Page 19 of 37


Key regulatory requirements are:

o National Historic Preservation Act

• Alternatives 2C, 3B, 3C, and 3D all have the same level of impact to historic resources

• Alternative 2B has the greatest level of impact due to the removal of TP-2

o Clean Water Act

o Vermont Water Quality Standards

• All alternatives will comply with the Clean Water Act and VT WQS provided the discharge from the passive treatment systems meets the requirements of these regulations at the designated point of compliance


Page 20 of 37


Key regulatory requirements (continued):

o VT Solid Waste Management Rules

• Waivers have been included to allow: • No cover requirement for TP-3 • Final grades to be determined by

design • Slopes to be as steep as possible

based on stability evaluation • Elimination of infiltration barrier on

slopes if design can demonstrate that water that falls on slopes will not infiltrate the tailings

• Top of TP-1 and TP-2 (non-slope areas) must have an infiltration barrier as part of cover system to comply with VT SWMR

• Only Alternatives 2B, 2C, and 3B comply with the VT SWMR (Alternatives 3C and 3D fail this criterion)


Page 21 of 37


Long-term effectiveness of alternatives 3C and 3D is less certain given the minimal soil cover in 3C and the unproven technology for 3D

3C has the lowest cost, while 2B, 2C, 3B, and 3D all have similar costs

3C requires the least truck volume, 3B requires the most truck volume, and 2B, 2C, and 3D have similar truck volume


Page 22 of 37

EPA Proposes Alternative 2C

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)


Page 23 of 37


4. Collection and treatment of water that discharges at the toe of TP-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


Page 24 of 37


6. Preservation of TP-3

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

• VT ANR and VT State Historic Preservation Office are key decision makers in addition to EPA

• VT ANR has recommended to EPA Option 1, the complete preservation of TP-3

• Final decision will be made after the design studies allow for a revised cost estimate for the maintenance of TP-3

• VT ANR is depending upon additional revenue to support TP-3 maintenance costs

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


Page 25 of 37

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EPA 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

o The alternative measures 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


Page 27 of 36

Technical Evaluation of EE/CA

EPA regularly consulted with the EPA experts in western Regions and assembled an expert team to support the development of the EE/CA

EE/CA development team O EPA (Regional site team) O USACE (Regional site team) O USGS (National acid mine experts) O USDOE (former Bureau of Mines expert) oADL OVTANR

Technical review and comments on EE/CA were provided by the mining experts from the following:

O URS Corp O Knight Piesold, Inc. O Shepard Miller, Inc. O Hedin Environmental, Inc. O Amerikanuak, Inc.

The EE/CA was also reviewed by TAG consultants Dr. Richard Downer and Dr. Sherwood Reed


Page 28 of 36

Public Comment Process

Public comment period will be open from March 15, 2002 to April 15, 2002

Three ways to comment:

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

o Submit email to [email protected] or fax (617) 918-1291 to EPA no later than April 15, 2002

o Read your comment into the public record at the hearing at 7 p.m. on April 10, 2002 at Barrett Hall in South Strafford


Page 29 of 36

mailto:[email protected]


• Meetings on March 13th and March 14th are information meetings

• Comments will not be recorded during these meetings

• A stenographer will be present at the April 10, 2002 meeting to record comments

o EPA will limit the time for each comment 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

• EPA will prepare a response to comments as part of the Action Memorandum


Page 30 of 36


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

Many of the Site documents are also available at the epa.gov/region l/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"


Page 31 of 36


Send written comments to:

Edward Hathaway EPA Region 1 Suite 1100 (HBT) 1 Congress Street Boston, MA 02114-2023

Or

Fax: (617) 918-1291

Or

Email: [email protected]


Page 32 of 36

mailto:[email protected]

Next Steps

EPA evaluates public and state comments and develops an Action Memorandum that describes what action EPA will take at the Site

EPA seeks funding for Design of NTCRA

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


Page 33 of 36

Next Steps

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

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

EPA will complete the investigation of the Site during 2002 and 2003

Final cleanup proposal scheduled for 2003/2004


Page 34 of 36

Summary

EPA wants to acknowledge and express appreciation for the hard work and dedication of the members of the EMCAG and TAG group (CHC) in working with EPA for the past two years

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

Cleanup actions must comply with law

The Vermont Solid Waste Management Rules, Clean Water Act, and Vermont Water Quality Standards set the parameters for the cleanup alternatives


Page 35 of 36

Summary

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

o environmental protection o cost effectiveness o minimization of long-term costs o reduction in truck traffic, and historic

preservation

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


Page 36 of 36

Documents

PUBLIC INFORMATION MEETING PRESENTATION: … · EPA investigations confirmed previous studie bsy VT ANR, USAGE, ... active (waste water treatment plant o)r passive (biological system