U.S. EPA Contaminated Site Cleanup Information (CLU-IN)


U.S. Environmental Protection Agency
U.S. EPA Technology Innovation and Field Services Division
Elizabeth Mine, South Stratford, VT
Superfund Removal & NPL
 
 
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TP-4 Before Excavation
TP-4 Before
Excavation
TP-4 After Restoration
TP-4 After
Restoration
TP-1A Soil Cap
TP-1A Soil Cap
TP-1A Slope Stabilization
TP-1A Slope
Stabilization


Cleanup Objectives: Restore surface water of Copperas Brook, the West Branch of the Ompompanoosuc River, and resources further downstream that have been negatively impacted by acid rock drainage resulting from runoff passing through waste rock and tailing piles created by historic iron sulfate and copper mining activities

Green Remediation Strategy: Reduce air contaminants associated with onsite or offsite fuel consumption, use onsite rather than imported natural resources for remedy construction and site restoration, establish processes for maximum recycling or reuse of waste materials, and initiate a procurement process for environmentally preferred products, while reducing the volume of materials entering the waste stream and assuring preservation of the site's historic aspects and ecosystem services

  • Use bio-based diesel instead of conventional diesel to reduce emission of particulate matter, greenhouse gases (GHGs), and other air pollutants when excavating waste rock, segregating and transferring various soils for onsite consolidation and use, constructing surface water diversions, and installing a soil cap system
  • Identify onsite resources to generate "borrow" materials needed for constructing the cap system and manufacturing as-needed topsoil, to avoid generation and transport of comparable materials from offsite sources
  • Explore innovative methods to better prevent soil erosion and control stormwater runoff while improving ecosystem service protection during construction and long-term maintenance of the cap system
  • Restore excavated/backfilled areas to more natural conditions by seeding native plants that need little/no irrigation or other maintenance and support local and migratory wildlife
  • Adopt a project-wide consumable recycling program, including evaluation of potential construction materials that can be recycled, recovered, or re-used
  • Choose manufactured products that are verified by EPA, the U.S. Department of Agriculture, or ISO standards as environmentally friendly or preferable
  • Consult with local landowners and regional organizations such as the Vermont State Historic Preservation Office to identify project methods that would minimize disruption to this rural community and the site, which is eligible for the National Register of Historic Places
  • Conduct a value engineering study during the design phase of long-term remedial actions to identify potential improvements to the efficiency of cleanup operations

Results:

  • Used a 4.7-acre onsite area to develop the natural resource (borrow) materials needed for various cleanup activities; over one year, the area produced approximately 93,000 cubic yards of earthen fill (including over 87,000 cubic yards of till/soil and 4,300 cubic yards of boulders), which avoided nearly 6,200 trucks trips (each with a capacity of 15 cubic yards) traveling on local roads in order to import the materials and averted approximately 945,000 pounds of associated CO2 emissions
  • Reducing onsite emission of air contaminants through use of biodiesel (rated B-20); during three months of 2011 construction work, for example, use of 6,500 gallons of B-20 instead of conventional diesel was estimated to reduce particulate matter by 12%, hydrocarbons by 20%, carbon monoxide by 12%, nitrogen oxides by 2%, sulfur dioxide by 20%, and carbon dioxide by 16%
  • Reducing project-related fuel consumption through a "zero idle" policy for onsite vehicles and machinery, carpooling among site personnel, and use of hybrid/economy vehicles wherever possible
  • Restored 65% of the ground cover on the initial, 4-acre waste rock excavation area (known as "TP-4") within two years; the selected seed mixes were applied on borrow soil by way of hand-broadcast and drilling techniques and targeted plant species particularly suitable for wet meadows or forests; conservation purposes such as erosion control and creation of habitat and food sources for insects, birds, and other wildlife; and diversification of grasses and wildflowers able to thrive in dry or moist conditions
  • Reused rip-rap originally emplaced around an adjacent waste rock excavation area (known as "TP-1A") for later construction of the area's soil cap; the capping material included approximately 1,000 cubic yards of soil that had been previously used as temporary backfill in the TP-4 excavation area
  • Began recycling construction materials and incorporated a product recycling evaluation into procurement sourcing, wherever applicable; for example, approximately 30 cubic yards of recyclable HDPE geomembrane liner and 96 HDPE liner cores (each 20 feet in length by 6 inches in width) were recycled in 2011
  • Installed biodegradable, wood fiber-based material on all slopes adjacent to the completed TP-1A soil cap, to control erosion while allowing revegetation (via hydraulic seeding) to occur and minimizing potential hazards to wildlife sometimes posed by synthetic mesh blankets; the material was applied via a hand-held spray device that could be deployed with minimal foot or truck traffic
  • Emplaced tubular devices ("socks") made of organic materials such as recycled compost on ground surfaces along the TP-1A soil cap perimeter, to control sediment and to contain and filter stormwater runoff prior to its gradual subsurface infiltration; when compared to a typical silt fence needing placement within constructed trenches, performance monitoring over one year suggested that the tubular system contained 50% more surface water runoff, returned more nutrients to the subsurface, and involved less maintenance
  • Used biodegradable instead of polyethylene sandbags in approximately 1,000 applications to prevent erosion and control stormwater runoff in highly vulnerable areas adjacent to Copperas Brook
  • Contracted with local farms to obtain the hay bales used as mulch in disturbed areas and the manure used as a source of organic material for onsite manufacturing of topsoil
  • Salvaged onsite wood debris for use in stabilizing steep slopes on relatively isolated portions of the site
  • Preserved ecological habitat for the region's endangered bats by installing bat grates at the mine openings
  • Implemented a project-wide consumable waste recycling program, which resulted in recycling of approximately 40 cubic feet of cans, 44 cubic feet of paper, 1,800 cubic feet of plastics, and 28 cubic feet of glass during 2011

Property End Use: Environmental or historic education and regional greenspace

Point of Contact: Ed Hathaway, U.S. EPA Region 1

Update: March 2012

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