Or. Admin. Code § 340-071-0310 - Steep Slope Systems

(1) General conditions for approval. Construction-installation permits may be issued for steep slope systems serving single-family dwellings on slopes in excess of 30 percent if all the following requirements can be met.

(a) Slope does not exceed 45 percent.

(b) The soil is well-drained with no evidence of saturation to a depth of 60 inches.

(c) The soil has a minimum effective soil depth of 60 inches.

(2) Construction requirements.

(a) Seepage trenches must be installed at a minimum depth of 30 inches and a maximum depth of 36 inches below the natural soil surface on the downhill side of the trench and must contain a minimum of 18 inches of drain media and 12 inches of native soil backfill.

(b) The system must be sized at a minimum of 75 linear feet per 150 gallons projected daily sewage flow.

Notes

Or. Admin. Code § 340-071-0310

DEQ 10-1981, f. & ef. 3-20-81; DEQ 8-1983, f. & ef. 5-25-83; DEQ 9-1984, f. & ef. 5-29-84; DEQ 11-2004, f. 12-22-04, cert. ef. 3-1-05

Stat. Auth.: ORS 454.625 & 468.020

Stats. Implemented: ORS 454.615 & 454.775