NR 182.106(2)(j)(j) An operator shall ensure that any mining waste facility designed with a liner or situated in sufficiently low permeability soils to either partially or totally contain leachate are designed with a leachate management system that can effectively remove leachate, prevent surface seeps, and promote adequate settlement to permit final reclamation.

NR 182.106(2)(k)(k) An operator may dispose or store only waste types and sources listed on the license or otherwise approved by the department in writing, in an approved mining waste facility.

NR 182.106(2)(L)(L) An operator shall maintain the final slopes of a closed mining waste site to be no less than 2 percent and no greater than 33 percent unless the site or facility is specifically designed for a final use compatible with other slopes.

NR 182.106(2)(m)(m) An operator shall ensure that all sites have a final cover designed to minimize infiltration and subsequent leachate production unless the department approves an alternate cover in the reclamation plan or unless the department determines that such cover is not necessary to comply with the environmental standards of this chapter.

NR 182.106(2)(n)(n) An operator shall make provisions for the collection and treatment of leachate for all sites designed to contain leachate.

NR 182.106(2)(o)(o) An operator shall locate, design, construct, and operate a waste site so that any liner system or naturally occurring soil barrier is compatible with all disposed or stored mining waste.

NR 182.106(2)(p)(p) An operator shall ensure that tailings impoundments and other water-holding facilities constructed as part of the mining waste site are designed to contain the 100-year, 24-hour rainfall event and to prevent overtopping by waves during this design storm, or designed to contain the 100-year, 24-hour rainfall event and maintain a minimum of 5 feet of freeboard. The size of the storm event shall be determined based on current rainfall probability data, including models or forecasts, approved by the department for this purpose.

NR 182.106(2)(q)(q) An operator shall select and design drainage or filter bed material to promote drainage, reduce the potential for piping, and be stable under leaching conditions.

NR 182.106(2)(r)(r) An operator shall ensure that material used in earth embankments or drainage or filter bed material is free, to the extent practicable, of vegetation, organic soils, frozen soils, and other extraneous matter that could affect the compactibility, density, permeability, or shear strength of the finished embankment.

NR 182.106(2)(s)(s) An operator shall compact embankment materials or drainage or filter bed materials to 95 percent of the maximum dry density as determined by the standard proctor compaction test or to a greater density as dictated by the embankment height. The material shall be compacted in lifts of 6 to 8 inches in thickness. If waste rock is approved by the department for use outside an earth core, compaction and crushing of such waste rock may not be necessary if the applicant demonstrates that stable slopes can be constructed and maintained without compaction and crushing of the waste rock.

NR 182.106(2)(t)(t) An operator shall provide emergency spill areas along the tailings pipeline corridor to allow for draining the pipeline, if necessary, in case of power interruptions or pipeline failure. Tailings pipelines should be self-draining to the tailings area or to an emergency spill area or both. In some cases, such as a long pipeline over rough country, the department may require several spill areas to be provided.

NR 182.106(3)(3) An operator shall design and operate mining waste facilities to ensure management of stormwater in a manner that minimizes uncontrolled releases and adverse environmental impacts. Provisions for stormwater management shall incorporate all of the following:

NR 182.106(3)(a)(a) An operator shall design storm water drainage ditches, structures, and sedimentation basins such that the construction of these items shall occur during the initial stage of construction to control runoff and limit entrained sediment from reaching surface water bodies.

NR 182.106(3)(b)(b) An operator shall incorporate all of the following concepts in the design of both temporary and permanent erosion and sediment control measures:

NR 182.106(3)(c)(c) An operator shall perform the design calculations required in pars. (d), (e), and (f) for the period in the mining waste facility’s development during which the combination of surface conditions and contributing acreage would result in the greatest runoff volume.

NR 182.106(3)(d)(d) An operator shall design all permanent storm water drainage ditches, sedimentation or retention ponds, swales, conveyance channels, channel linings, outlet protection, culverts, and other storm water control structures handling flow onto or off the mining waste facility to accommodate peak flow rates from a 100 year, 24-hour storm event. The size of the storm event shall be determined based on current rainfall probability data, including models or forecasts, approved by the department for this purpose.

NR 182.106(3)(e)(e) An operator shall design temporary and permanent sediment control measures to settle 0.015 mm size particles for all storms up to, and including, the 25 year, 24-hour storm. The surface area for permanent sediment basins shall be calculated using the rainfall intensity over the 25 year, 24-hour storm event for the mining waste facility. Principal spillways, and outlet protection for sediment basins shall be designed to pass a 100 year, 24-hour storm event. Emergency spillways for sedimentation basins shall be designed to pass a 100 year, 24-hour storm event. The size of the storm event shall be determined based on current rainfall probability data, including models or forecasts, approved by the department for this purpose. The design of the dewatering structures for sediment basins shall be selected such that the basin is dewatered in no less than 3 days. An analysis shall be performed to document compliance with this requirement.

NR 182.106(3)(f)(f) An operator shall design containment berms placed around active fill areas to control and collect the liquid volume resulting from the 100 year, 24-hour storm event. The design shall consider the volume of liquid generated from active fill areas, including all areas with exposed solid waste or areas with waste covered by daily cover. The size of the storm event shall be determined based on current rainfall probability data, including models or forecasts, approved by the department for this purpose. Storm water in contact with active fill areas shall be handled and treated as leachate.

NR 182.106(3)(g)(g) An operator shall divert storm water away from the active fill area of the mining waste facility and any borrow areas to a sedimentation control structure.

NR 182.106(3)(h)(h) An operator shall ensure that storm water drainage ditches, structures, and sedimentation basins discharge along existing drainage patterns capable of accepting the anticipated flow volume. An operator shall perform an analysis to determine the amount and velocity of runoff prior to mining waste facility development and to document compliance with this requirement.