To encourage advances in mining and reclamation practices and to allow postmining land use for industrial, commercial, residential, or public use, including recreational facilities, the department may, with approval by the secretary of the United States department of the interior, authorize departures in individual cases and on an experimental basis from the environmental protection performance standards of this part. These departures may be authorized if the experimental practices are potentially at least as environmentally protective, during and after mining operations, as those required by this part; if the mining operations approved for particular land use or other purposes are not larger or more numerous than necessary to determine the effectiveness and economic feasibility of the experimental practices; and if the experimental practices do not reduce the protection afforded public health and safety below that provided by this part.