WAC 246-272A-0140   Proprietary distribution products -- Certification and registration.  (1) Manufacturers shall register proprietary distribution products, including gravelless distribution products and subsurface dripline products, with the department before the local health officer may permit their use.

     (2) Manufacturers desiring to sell proprietary distribution products shall certify that the product(s) meets the standards established in this chapter and register their product(s) with the department using the process described in WAC 246-272A-0145.

     (3) Proprietary gravelless distribution products shall:

     (a) Be constructed or manufactured from materials that are nondecaying and nondeteriorating and do not leach chemicals when exposed to sewage and the subsurface soil environment;

     (b) Provide liquid storage volume at least equal to the storage volume provided within the thirty percent void space in a twelve-inch layer of drainrock in a drainrock-filled distribution system. This storage volume must be established by the gravelless distribution products, system design and installation and must be maintained for the life of the system. This requirement may be met on a lineal-foot, or on an overall system design basis;

     (c) Provide suitable effluent distribution to the infiltrative surface at the soil interface; and

     (d) Maintain the integrity of the trench or bed. The material used, by its nature and its manufacturer-prescribed installation procedure, must withstand the physical forces of the soil sidewalls, soil backfill and the weight of equipment used in the backfilling.

     (4) Proprietary subsurface dripline products shall:

     (a) Be warranted by the manufacturer for use with sewage and for resistance to root intrusion.

     (b) Incorporate emitters with a maximum nominal rated discharge of 1.3 gallons per hour. Emitter discharge rate may be controlled either by use of pressure-compensating emitters or with a pressure regulator.

     (c) Be color-coded purple to identify that the pipe contains nonpotable water from a sewage source.



[Statutory Authority: RCW 43.20.050. 05-15-119, § 246-272A-0140, filed 7/18/05, effective 9/15/05.]