OAR 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.

Source: Rule 340-071-0310 — Steep Slope Systems, https://secure.­sos.­state.­or.­us/oard/view.­action?ruleNumber=340-071-0310.

340‑071‑0100
Definitions 340‑071‑0110
Purpose 340‑071‑0115
Technical Review Committee 340‑071‑0120
Jurisdiction and Policy 340‑071‑0130
General Standards, Prohibitions and Requirements 340‑071‑0135
Approval of New or Innovative Technologies, Materials, or Designs for Onsite Systems 340‑071‑0140
Onsite System Fees 340‑071‑0150
Site Evaluation Procedures 340‑071‑0155
Existing System Evaluation Report 340‑071‑0160
Permit Application Procedures — Construction, Installation, Alteration, and Repair Permits 340‑071‑0162
Permit Application Procedures — WPCF Permits 340‑071‑0165
Permit Denial Review — Construction-Installation, Repair, Alteration Permits 340‑071‑0170
Pre-Cover Inspections 340‑071‑0175
Certificate of Satisfactory Completion 340‑071‑0185
Decommissioning of Systems 340‑071‑0200
Prior Construction Permits or Approvals 340‑071‑0205
Authorization to Use Existing Systems 340‑071‑0210
Alteration of Existing Onsite Wastewater Treatment Systems 340‑071‑0215
Repair of Existing Systems 340‑071‑0220
Standard Subsurface Systems 340‑071‑0260
Alternative Systems, General 340‑071‑0265
Capping Fills 340‑071‑0275
Pressurized Distribution Systems 340‑071‑0280
Seepage Trench System 340‑071‑0285
Redundant Systems 340‑071‑0290
Conventional Sand Filter Systems 340‑071‑0295
Conventional Sand Filter Design and Construction 340‑071‑0302
Recirculating Gravel Filter (RGF) 340‑071‑0310
Steep Slope Systems 340‑071‑0315
Tile Dewatering System 340‑071‑0320
Split Waste Method 340‑071‑0325
Gray Water Waste Disposal Sumps 340‑071‑0330
Nonwater-Carried Systems 340‑071‑0335
Cesspools and Seepage Pits 340‑071‑0340
Holding Tanks 340‑071‑0345
Alternative Treatment Technologies (ATTs) 340‑071‑0360
Absorption Trenches in Saprolite 340‑071‑0400
Geographic Area Special Considerations. 340‑071‑0410
Rural Area Consideration 340‑071‑0415
For Cause Variances 340‑071‑0420
Hardship Variances 340‑071‑0425
Variance Officers 340‑071‑0430
Variance Hearings and Decisions 340‑071‑0435
Variance Permit Issuance, Inspections, Certificate of Satisfactory Completion 340‑071‑0440
Variance Appeals 340‑071‑0445
Variance Administrative Review 340‑071‑0460
Moratorium Areas 340‑071‑0500
Community Systems 340‑071‑0520
Large Systems 340‑071‑0600
Sewage Disposal Service Licenses 340‑071‑0650
Training and Certification Requirements for System Installers and Maintenance Providers 340‑071‑0800
Tables
Last Updated

Jun. 8, 2021

Rule 340-071-0310’s source at or​.us