Minnesota Administrative Rules

7083.4070 DISTRIBUTION MEDIUM; CERTIFICATION AND REGISTRATION.

A.

Drainfield rock distribution media shall meet the requirements in item D and the requirements contained in the recommended standards and guidance for public domain distribution products before local units of government are allowed to permit its use.

B.

For nonrock distribution media, manufacturers shall register the distribution media, including gravelless distribution media and subsurface drip dispersal products, with the commissioner before the local unit of government is allowed to permit their use.

C.

Manufacturers desiring to sell distribution media shall certify that the media meet the standards established in this part and register the media with the commissioner using the process in part 7083.4080.

D.

Distribution media must:

(1)

be constructed or manufactured from materials that are nondecaying and nondeteriorating and do not leach unacceptable chemicals when exposed to sewage and the subsurface soil environment;

(2)

provide void space at least equal to the void space provided within a 12-inch layer of drainfield rock in a drainfield-rock-filled distribution system. The void space must be established by the distribution medium, system design, and installation. The density of the media must be maintained throughout the life of the system. This requirement is allowed to be met either on a lineal foot basis or on an overall system design basis;

(3)

support the distribution pipe and provide suitable effluent distribution and infiltration rate to the absorption area at the soil interface; and

(4)

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

E.

Subsurface drip dispersal products must:

(1)

be warrantied by the manufacturer for use with sewage and for resistance to root intrusion;

(2)

have a means to inhibit the accumulation of slime and bacterial growth within the drip line and plugging of the emitters. Emitter discharge rate must be controlled by the use of either pressure-compensating emitters or a pressure regulator.

Statutory Authority:

MS s 115.03; 115.55

History:

32 SR 1420

Published Electronically:

March 11, 2011