NAC445A.433. Minimum design criteria: Universal requirements; areas where groundwater is near surface; proximity of new process components to dwellings; liability for degradation of water.

     1. The following minimum design requirements apply to all process components:

     (a) In areas where annual evaporation exceeds annual precipitation, a process component must achieve zero discharge.

     (b) All sources must be designed to minimize releases of contaminants into groundwaters or subsurface migration pathways so that any release from the facility will not degrade waters of the State.

     (c) All process components must be designed to withstand the runoff from a 24-hour storm event with a 100-year recurrence interval.

     (d) The primary fluid management system must be designed to be able to remain fully functional and fully contain all process fluids including all accumulations resulting from a 24-hour storm event with a 25-year recurrence interval. The Department may require additional containment based on the following factors:

          (1) Proximity to surface water bodies;

          (2) Depth to groundwater; and

          (3) Proximity to population.

Ê Contingency plans for managing process contaminated flows in excess of the design quantity must be described in the appropriate operating plans.

     (e) The fluid management system must be designed to be functional for 5 years after the projected operating life of the process component and permanent closure period.

     (f) The design of the process components must take into consideration the proposed range of operating conditions for each component and the history of seismic events at the site in order to preclude any differential movement or shifting of the subbase, liner or contained material which endangers primary or secondary containment integrity.

     2. Additional containment of process fluids may be required in areas where groundwater is considered to be near the surface. Groundwater is considered to be near the surface if:

     (a) The depth from the surface to groundwater is less than 100 feet and the top 100 feet of the existing formation has a coefficient of permeability greater than that exhibited by 100 feet of 1x10-5 cm/sec material;

     (b) Open fractured or faulted geologic conditions exist in the bedrock from the surface to the groundwater; or

     (c) There is an inability to document that all exploratory and condemnation borings beneath the site have been adequately sealed.

     3. No new process component containing process fluids may be located within 1,000 feet of any dwelling which is occupied at least part of the year and which is not a part of the facility. This restriction does not apply to modifications at a facility which predate such a dwelling.

     4. The application of minimum design criteria does not release the holder of a permit from liability for degradation to waters of the State caused by the facility.

     (Added to NAC by Environmental Comm’n, eff. 9-1-89)—(Substituted in revision for NAC 445.2436)