NAC445A.6706. Pumping facilities: Hydropneumatic systems.

     1. Hydropneumatic systems:

     (a) Must not be used in a public water system with 150 or more service connections.

     (b) Shall be deemed inadequate for protection from fire and the storage of water.

     2. If a hydropneumatic system is used:

     (a) The tank and its appurtenances must be completely housed and, except as otherwise approved by the Division or the appropriate district board of health, located above the normal surface of the ground. If the Division or the appropriate district board of health authorizes the location of the tank or any appurtenances below the ground, there must be adequate drainage, heating, ventilation, lighting, maintenance and protection from flood.

     (b) The hydropneumatic system must be designed to provide a minimum pressure of at least 30 psi at all points in the distribution system during peak hour demand. A pressure gauge must be installed on the inlet line for the pressure tank.

     (c) The pressure tanks must be constructed in such a manner that:

          (1) The tanks meet anticipated requirements for pressure.

          (2) The interior coatings of the tanks are determined to be compatible with drinking water.

          (3) The tanks are equipped with a 24-inch access manhole, a drain, control equipment that consists of a pressure gauge, a glass for sighting water, an air blowoff and a means for adding air, and pressure-operated controls for starting and stopping the pumps.

          (4) Bypass piping is provided that will facilitate the repair or coating of the tanks.

          (5) The amount of the gross volume, as expressed in gallons, of the hydropneumatic tank is at least 10 times the amount of the capacity, as expressed in gallons per minute, of the largest pump in the hydropneumatic system.

     (d) At least two pumping units must be provided. The capacity of the wells and pumps in the hydropneumatic system must be at least 10 times the average day demand.

     (e) The method used to adjust the volume of air must be approved by the Division or the appropriate district board of health. The compressors must deliver an adequate volume of air, which has been filtered and is free of oil, to the pressure tank.

     (Added to NAC by Bd. of Health, eff. 2-20-97; A by Environmental Comm’n by R194-08, 10-27-2009)