Onsite Wastewater Management Program 2025

Proposed rule

Rulemaking contact: Kyle Nelson, 503-781-7376

The intent of this rulemaking is to address sewer availability and accessory dwelling unit (ADU) issues prompted by bills enacted by the 2023 Legislature, and to generally modernize, clarify and improve program rule language, including enhancing environmental protection in high-risk areas. The last substantial onsite program rule changes occurred in 2014.

Over 30% of Oregonians dispose of wastewater from their homes and businesses through the use of septic systems. The siting, design, installation, and ongoing operation and maintenance of septic systems is regulated through DEQ's Onsite Wastewater Management Program. Without this oversight, septic systems can fail or malfunction, pollute Oregon's land and waterways with raw sewage, and create public health hazards.

The need for this rulemaking has existed for several years and DEQ has had to postpone or suspend prior attempts at completing similar rulemaking efforts. In 2019, DEQ suspended the onsite program rulemaking to conduct additional outreach to key interested parties. However, an unexpected shortage in DEQ staff resources occurred, prolonging the suspension of the rulemaking process indefinitely. The COVID-19 pandemic disrupted program operations; and the Labor Day wildfires destroyed over 5,000 homes and businesses in rural Oregon, requiring additional DEQ onsite program involvement in the recovery.

Despite these events and the suspension of the rulemaking effort, the ultimate need for updates and changes to the rules did not and has not changed. In fact, outcomes of the 2023 Legislature have resulted in increased needs for DEQ to conduct onsite program rulemaking, specifically related to ADUs and sewer availability. The passage of SB 835 directs the EQC to adopt rules setting forth conditions for approving proposal to permanently connect accessory dwelling unit located on same lot or parcel as single-family dwelling to same subsurface sewage disposal system or alternative sewage disposal system. SB 931 authorizes the EQC to adopt rules for determining whether community or area-wide sewerage system is available for purposes of sewage disposal system construction permit. 

Advisory committee

DEQ is convening an advisory committee to review the technical issues and fiscal impacts related to the proposed rules. In convening this committee, DEQ has appointed members that reflect the range of entities that are both directly and indirectly affected by proposed changes to the rules.