|
|
|
 |
 |
Lower Area One Operable Unit |
 |
|
Environmental
Location: Butte, Montana
Owner: ARCO (Atlantic Richfield Company)
Engineer: ESA Consultants/Pioneer Technical Services
Contract Value: Confidential at owner’s request
Contract Type: Fixed Unit Price (competitive bid)
 |  |  |  |  |
 |  |  | | |
| *Click on thumbnail to enlarge |
- Removed 1.04 million CY mine tailings and contaminated soil on 120-acre Superfund site
- All excavations below water table -- extensive dewatering throughout the site
- Backfilled 630,000 CY clean zone material from off-site borrow sources
- Constructed 4,500 LF stream channel diversions lined with riprap and geofabric
- Reconstructed 7,700 LF meandering Silver Bow Creek Channel with imported alluvial rock and gravel
- Constructed 5,700 LF flood dike and hydraulic control channel
- Removed 15,000 CY contaminated surficial tailing material
- Established borrow sites and sedimentation ponds, built haul roads, reclaimed borrow site once complete
- Capped 60-acre disposal site with haul and placement of 325,000 CY imported zone material
- 275,000 SY geofabric and drainage system
- Decontamination procedures for personnel and equipment
- Abandonment, demolition and preservation of wells
- Miscellaneous force main and utility work
- Constructed five-acre Geosynthetic Clay Layer (GCL)-lined sedimentation ponds
- Constructed 4,000 LF of GCL-lined drainage ditch with erosion mat
- Constructed two separate wetland demonstration projects on the 120-acre Superfund site
In the fall of 1996, Barnard was awarded a privately bid contract to reclaim a mine site where 40 years of mining had left lifeless, gray-orange murky tailings. The project involved removing and hauling the mine tailings within a 100-year floodplain from the 120-acre Superfund site to a repository two miles away. Once the tailings were removed, the site had to be backfilled with clean material. Meandering stream channels were created to encourage the presence of fish and wildlife; vegetation was planted. The 60-acre repository site was capped with a five-layer zoned, impervious membrane and will be the future home of an ARCO-funded recreation park and baseball complex.
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|