A. The system designer is to identify the use of a sand filter liner with underdrain and boot as a part of the application for on-site sewage disposal permit, and provide specifications detailing design and installation requirements.

B. The boot is to be installed by the manufacturer or the manufacturer’s representative.

C. The boot outlet is to be bedded in sand.

D. The boot is to be sized to accommodate a four-inch underdrain outlet pipe.

E. The boot is to be secured to the four-inch outlet pipe with two stainless steel bands and screws, and sealant strips as recommended by the manufacturer.

F. The underdrain is to be designed in accordance with Recommended Standards and Guidance for Performance, Application, Design, and Operation and Maintenance Intermittent Sand Filter Systems, July 1, 2007, Appendix C, Underdrains, and exit the side of the liner.

G. Sewer pipe from the sand filter to the drainfield shall be ASTM 3034 ring tight.

H. The trench from the sand filter to the drainfield shall be backfilled with a minimum five-foot clay or hardpan dam to prevent the trench from acting as a conduit for groundwater movement towards the drainfield.

I. During the initial implementation period of this procedure the Snohomish Health District may require performance testing of the sand filter/boot for leakage. The need for a performance test shall be discussed and agreed upon at the preconstruction conference. The performance test shall be conducted by: