NR 664.0193(7)(7) The owner or operator may obtain a variance from the requirements of this section if the department finds, as a result of a demonstration by the owner or operator that alternative design and operating practices, together with location characteristics, will prevent the migration of any hazardous waste or hazardous constituents into the groundwater or surface water at least as effectively as secondary containment during the active life of the tank system; or, that in the event of a release that does migrate to groundwater or surface water, no substantial present or potential hazard will be posed to human health or the environment. New underground tank systems may not, per a demonstration in accordance with par. (b), be exempted from the secondary containment requirements of this section. NR 664.0193(7)(a)(a) In deciding whether to grant a variance based on a demonstration of equivalent protection of groundwater and surface water, the department will consider all of the following: NR 664.0193(7)(a)3.3. The hydrogeologic setting of the facility, including the thickness of soils present between the tank system and groundwater. NR 664.0193(7)(a)4.4. All other factors that would influence the quality and mobility of the hazardous constituents and the potential for them to migrate to groundwater or surface water. NR 664.0193(7)(b)(b) In deciding whether to grant a variance based on a demonstration of no substantial present or potential hazard, the department will consider all of the following: NR 664.0193(7)(b)1.1. The potential adverse effects on groundwater, surface water and land quality taking into account all of the following: NR 664.0193(7)(b)1.a.a. The physical and chemical characteristics of the waste in the tank system, including its potential for migration. NR 664.0193(7)(b)1.d.d. The potential for damage to wildlife, crops, vegetation and physical structures caused by exposure to waste constituents. NR 664.0193(7)(b)2.2. The potential adverse effects of a release on groundwater quality, taking into account all of the following: NR 664.0193(7)(b)2.d.d. The existing quality of groundwater, including other sources of contamination and their cumulative impact on the groundwater quality. NR 664.0193(7)(b)3.3. The potential adverse effects of a release on surface water quality, taking into account all of the following: NR 664.0193(7)(b)3.d.d. The current and future uses of surface waters in the area and any water quality standards established for those surface waters. NR 664.0193(7)(b)3.e.e. The existing quality of surface water, including other sources of contamination and the cumulative impact on surface-water quality. NR 664.0193(7)(b)4.4. The potential adverse effects of a release on the land surrounding the tank system, taking into account all of the following: NR 664.0193(7)(c)(c) The owner or operator of a tank system, for which a variance from secondary containment had been granted in accordance with the requirements of par. (a), at which a release of hazardous waste has occurred from the primary tank system but has not migrated beyond the zone of engineering control (as established in the variance), shall do all of the following: