WAC 246-291-210   Distribution systems.  (1) All distribution reservoirs shall have suitable watertight roofs or covers preventing entry by birds, animals, insects, and dust and shall include appropriate provisions to safeguard against trespass, vandalism, and sabotage. All new distribution reservoirs shall be able to be drained by gravity to daylight.

     (2) The owner shall ensure that the distribution system is sized and evaluated using a hydraulic analysis acceptable to the department.

     (3) Systems designed to provide fire hydrants shall have a minimum distribution main size of six inches (150 mm).

     (4) New water systems or additions to existing systems shall provide a design quantity of water at a positive pressure of at least thirty psi throughout the system under peak hourly design flow conditions measured at any customer's water meter or at the property line if no meter exists.

     (5) If fire flow is to be provided, the distribution system shall be designed to provide the required fire flow at a pressure of at least twenty psi throughout the system during peak hourly design flow conditions.

     (6) Booster pumps needed for individual services shall be subject to review and approval by the department. Installation shall be made under the supervision of the owner to ensure cross-connection control requirements are met. Installation of booster pumps which are an integral part of the system design shall be inspected and certified by the engineer.



[Statutory Authority: RCW 43.20.050. 94-14-002, § 246-291-210, filed 6/22/94, effective 7/23/94.]