2015-03-23_REPORT - M1977424 - Laserfiche WebLink

Home Browse Search

Logan Wash Mine Annual Report Permit No. M- 1977 -424 Area 13: Miscellaneous Access Roads Documentation that defines the locations of the Miscellaneous Access Roads (Area 13) in detail in the original reclamation plan is limited (see Table 2). Based on field observations a number of older roads have been reclaimed and are no longer used. These roads are located on the slope above the Upper Bench and on the slope between the Upper Access Road and the Lower Access Road. It is uncertain what portions of these roads have been released from warranty, but it is assumed that some were released in 1986 because of their association with other areas released at that time. The remaining (existing) roads that may have been included in Area 13 are: 1) Upper Access Road, 2.9 acres; 2) Lower Access Road 1.0 acres; 3) Upper Bench Road 1.1 acres; 4) Lower Bench Road 0.9 acres; and 5) Evaporation Pond Road 1.2 acres. These acreages have been estimated using GIS and assuming an average road width of 24 feet. Of these roads, the Upper Bench Road was revegetated in 2005, and will be submitted for warranty release in the near future. All other roads shall remain open for use. Therefore, the total estimated unreleased acreage for Area 13, Miscellaneous Access Roads, is at least 7.1 acres. 2.3 Structures 2.3.1 Vaults, Pipelines, and Evaporation Pond Structures that remain at the mine site include two vault structures, one on the Lower Bench and one on the Research Mine Bench, and a capped and vented ventilation shaft. Pipelines include the retort water pipeline which conveys retort mine water from the sealed L -I portal at the mine site to the Evaporation Pond; the Logan Wash Mine mine water drainage pipeline (LW -001) which extends from the sealed L portal to the Lower Bench Vault and then to the newly constructed infiltration trench on the Lower Bench; and the Research Mine mine water drainage pipeline (LW -002) which extends from the sealed Research Mine portal through the Research Mine Vault to the Lower Bench Vault and on to Lower Bench discharge point. See Figure 2 for the locations of these structures. The two bench vaults are administered as confined space concrete structures with surface access - ways constructed just above grade. Depending on the final mine closure method, these structures may remain as permanent structures on the mine site to manage and monitor mine water drainage. The retort water pipeline was constructed with manhole clean -outs approximately every 600 feet; two manholes, the Upper Manhole and Lower Manhole, are accessed periodically to measure pipeline flows. The Upper Manhole is located in the vicinity of the former Heater Treater (Area 15), in the upper part of Logan Wash near the confluence with Dry Gulch. The Lower Manhole is located immediately north of the Evaporation Pond. Other manholes exist on the retort water pipeline that are buried by shallow road fill, colluvium, and vegetative litter, and have not been accessed in recent years. 2.3.2 Wells Wells associated with the Logan Wash Mine were constructed within and outside of the immediate mine area. Past reconnaissance has been conducted to locate and confirm the existence of these well sites. Eight wells were located and identified within the mine area and within Logan Wash. Several other wells were located at some distance from the mine (see Figure 3 and Table 3). Of the 8 identified wells in the mine area, one well, Well LWCW -IA, will remain in place as Western Water & Land, Inc. 3