R309-510-8. Storage Sizing

  (1) General.

  Each public water system, or storage facility serving connections within a specific area, shall provide:

  (a) equalization storage volume, to satisfy average day demands for water for indoor use and irrigation use,

  (b) fire flow storage volume, if the water system is equipped with fire hydrants intended to provide fire suppression water or as required by the local fire code official, and

  (c) emergency storage, if deemed appropriate by the water supplier or the Director.

  (2) Equalization Storage.

  (a) All public drinking water systems shall provide equalization storage. The amount of equalization storage varies with the nature of the water system, the extent of irrigation use, and the location and configuration of the water system.

  (b) Table 510-4 lists required equalization storage for indoor use. Storage requirements for non-community systems not listed in this table shall be determined by calculating the average day demands from the information given in Table 510-2.

TABLE 510-4

Storage Volume for Indoor Use

            Type Volume Required

                                            (gallons)

      Community Systems

Residential;

 per single resident service connection 400

Non-Residential;

 per Equivalent Residential Connection (ERC) 400

    Non-Community Systems

Modern Recreation Camp; per person 30

Semi-Developed Camp; per person

 a. with Pit Privies 2.5

 b. with Flush Toilets 10

Hotel, Motel and Resort; per unit 75

Labor Camp; per unit 25

Recreational Vehicle Park; per pad 50

Roadway Rest Stop; per vehicle 3.5

Recreational Home Development (i.e.,

developments with limited water use);

per connection (See Note 2 in Table 510-1) 400

  (c) Where a drinking water system provides water for irrigation use, Table 510-5 shall be used to determine the minimum equalization storage volumes for irrigation. The procedure for determining the map zone and irrigated acreage for using Table 510-5 is outlined in R309-510-7(3).

TABLE 510-5

Storage Volume for Irrigation Use

Map Zone Volume Required

                              (gallons/irrigated acre)

   1 1,782

   2 1,873

   3 2,528

   4 2,848

   5 4,081

   6 4,964

  (3) Fire Flow Storage.

  (a) Fire flow storage shall be provided if fire flow is required by the local fire code official or if fire hydrants intended for fire flow are installed.

  (b) Water systems shall consult with the local fire code official regarding needed fire flows in the area under consideration. The fire flow information shall be provided to the Division during the plan review process.

  (c) When direction from the local fire code official is not available, the water system shall use Appendix B of the International Fire Code, 2015 edition, for guidance. Unless otherwise approved by the local fire code official, the fire flow and fire flow duration shall not be less than 1,000 gallons per minute for 60 minutes.

  (4) Emergency Storage.

  Emergency storage shall be considered during the design process. The amount of emergency storage shall be based upon an assessment of risk and the desired degree of system dependability. The Director may require emergency storage when it is warranted to protect public health and welfare.