__001__ The zone of endangering influence for each injection well or each field, project or area of the State shall be determined according to either Section __001.01__ or __001.02__ of this Chapter. The zone of endangering influence shall be that area the radius of which is the lateral distance from an injection well, field or project in which the pressures in the injection zone may cause the migration of the injection and/or formation fluid into an underground source of drinking water or into an improperly constructed, plugged or abandoned well or test hole.

__001.01__ The radius of the zone should be calculated by using a mathematical model (e.g., modified Theis equation) and should be calculated for an injection time period at least equal to the expected life of the injection well or field. The owner or operator must demonstrate to the Director that the mathematical model used and the calculated zone of endangering influence are appropriate for the known hydrologic properties of the underlying formations.

__001.02__ A fixed radius around the well, or the perimeter of the field or project of not less than one-fourth mile may be used. In determining the fixed radius, the following factors shall be taken into consideration: Chemistry of injected and formation fluids; hydrogeology; population and ground water use and dependence; and historical practices in the area.

__001.03__ If the zone of endangering influence is determined by a mathematical model pursuant to Section __001.01__ of this Chapter, the permissible radius is the result of such calculation even if it is less than one-fourth mile.

__002__ The area of review for each injection well or each field, project or area of the State shall include the zone of endangering influence and that area at least two miles in radius extending beyond the zone of endangering influence.

__002.01__ For Class V wells authorized in Chapter 6 of this Title, the area of review for each injection well or each field shall be a radius of at least one half (1/2) mile from the point of injection.

Enabling Legislation: Neb. Rev. Stat. ยงยง 81-1504(2)(13);81-1505(9)

Legal Citation: Title 122, Ch.14, Nebraska Department of Environmental Quality