OAR 632-030-0027: Minimum Standards for a Reclamation Plan

A reclamation plan submitted under 632-030-0025 must meet the following minimum standards: (1) Final slopes must be stable. Reclaimed cutbanks may not have slopes exceeding 1-1/2 horizontal to 1 vertical (1-1/2H:1V). Final slopes may be blasted or sculpted to blend into adjacent landforms or for creation of habitat. The Department may require the submission of a reclamation blast plan to assure stable slopes will be created and adjacent property will be protected. The Department may also grant exceptions for slopes steeper than 1-1/2H:1V when the applicant can document that the slopes will be stable and if the steeper slopes: (a) Blend into the adjacent terrain; (b) Existed prior to mining; or (c) Are consistent with the approved subsequent beneficial use. (2) Interim and final above-water cutslopes for sites located within the boundaries of a 100-year floodplain can be no steeper than 3H:1V. (3) Slope requirements. (a) Fill slopes must be 2 horizontal to 1 vertical (2H:1V) or flatter. (b) Fill slopes steeper than 2H:1V may be approved if technical data supporting slope stability is approved by the Department. (c) In unconsolidated material or when slope length exceeds 100 lineal feet, 3H:1V slopes or flatter may be required to assure long-term stability. (d) Complex slope formations may be necessary to enhance habitat and post-mine landscape diversity. (e) Flatter slopes (5H:1V to 10H:1V) will be needed where wetland creation is proposed. (f) For sites within the 100-year floodplain, final above-water fill slopes can only be placed over cutslopes that are 3H:1V, or flatter, unless the Department agrees in writing to a different ratio based on a determination that the flood potential is very low. (4) Generally, final revegetation with native species of all disturbed areas consistent with future use is required unless the Department finds it unreasonable. The Department will, in most instances, consider revegetation successful if it provides a similar plant density in terms of ground or canopy cover and it is comparable to undisturbed areas in similar landscape positions. In arid or semi-arid regions, the Department may allow three years of growth prior to a revegetation evaluation. Otherwise, revegetation will be evaluated after one growing season. Vegetation test plots may be required to ensure establishment feasibility and/or long-term habitat goals in the reclamation plan. Vegetation monitoring may also be required to insure success of the approved plan. (5) Establishment of 3H:1V slopes from ordinary high-water level extending to six feet below ordinary low-water level for permanent water impoundments is required. In addition to the 3H:1V slopes, the Department may approve other sloping configurations where horizontal benches are incorporated as habitat features. (a) Other above- and below-water bank sloping may be approved for constructed alcoves or other habitat features or projects. (b) Establishment of a stable slope angle or benching for below-water slopes to insure an adequate foundation for the proposed in-water and above-water slopes or fills is required. (c) A geotechnical study may be required to address slope stability. (6) All stream channels and stream banks must be rehabilitated using procedures that minimize bank erosion, channel scour, and sedimentation; and maximize habitat. (7) Reclamation must be completed in a timely manner. If there is no production at a mine site for a period of five or more consecutive years, the permittee shall submit a report to the Department on the remaining reserves. The report must include an estimate of the quantity of the remaining mineral reserves. The report must be signed by a professional geologist or include drill logs or other quantitative analysis acceptable to the Department. If the submission of such data poses a financial hardship to the permittee, the Department will attempt to work with the permittee to provide the necessary geologic expertise as Department staff resources allow or the Department may waive this requirement. Any waiver provided by the Department must be in writing and must specify the duration for which the requirement is waived. (8) If the Department determines that the reserves are insignificant or the operator is unlikely to be able to economically mine the site in the reasonably foreseeable future, the Department will order reclamation and may establish a reasonable period for its completion.