Key Results

There are roughly 550,417 known OSS in local health jurisdictions across Puget Sound at the end of 2024. 86,425 of these systems are located in marine recovery and sensitive areas. 

• Most of these systems (85 percent in local health jurisdictions and 89 percent in marine recovery and sensitive areas) also had appropriate permits. 

The OSS Compliance indicator shows that compliance with inspection schedules is relatively low across local health jurisdictions, though percent compliance is higher in marine recovery and sensitive areas.  

• At the end of 2024, 145,695 OSS (26 percent of known systems) were compliant with state and local inspection schedules. In marine recovery and sensitive areas, 49 percent of these systems were compliant with inspection schedules. 
• The number of systems compliant with inspection schedules varied by local health jurisdictions, though most local health jurisdictions had higher percent compliance in marine recovery and sensitive areas. 

The OSS Failures indicator shows that a very small fraction of known systems have an unresolved failure. However, these failures could still pose a risk to environmental or public health. 

• At the end of 2024, 3,098 OSS had an unresolved failure. This number represents less than 1 percent of all known systems. 
• Failures were less frequent in marine recovery and sensitive areas. The percentage of systems with failures at the end of 2024 was 0.43 percent compared to 0.56 percent across all local health jurisdictions. 

These data on OSS serve as Indicators for progress toward region-wide, high-quality OSS management. They currently do not capture all the challenges faced by LHJs and homeowners to improve OSS management. They also do not capture the location of poorly managed OSS (non-compliant or OSS with failures) relative to shellfish beds. Additional studies can build upon these indicators to document and address barriers faced by LHJs and risks of impacts to shellfish beds. These indicators represent an important first step to publicize the efforts of LHJs and the status of OSS across Puget Sound.

What factors affect these Progress Indicators? 

Limited capacity to review OSS compliance and enforce regular inspections requirements

• Local health jurisdictions (LHJs) have limited capacity to identify and address non-compliant or failing systems, which can contribute to the number of unresolved failures. 
• LHJs vary in the extent of their ability to operate an operations and maintenance (O&M) program, which focus on OSS management. Frequent staff turnover can contribute to a limited ability to effectively operate these programs.
• Enforcement is often based on the willingness of local decision-makers to address the impacts of poorly managed OSS

Limited capacity to manage databases and data related to OSS management

• LHJs with limited staffing and funding capacities lack access to efficient resources and suffer from knowledge barriers to effectively track and maintain systems of data on OSS management.

Stable program financing

• Proper OSS management requires stable funding. Current funding can be highly variable between state fiscal years and biennia. Without stable funding, it is extremely difficult for LHJs to establish and implement a well-functioning OSS management program to identify and address pollution issues, educate homeowners, maintain databases, and offer incentives and rebates[1].

Homeowner education 

• Many homeowners are new to owning an OSS and may make assumptions or be ill-informed about the level of maintenance required. There is a still-prevalent belief that OSS are “free” and require little maintenance[1] over time.
  • LHJs conduct outreach by sharing brochures, hosting webinars, and mailing reminders, articles, etc.) to homeowners, but LHJs often vary in their capacity to host training events and share resources with homeowners.
• Homeowners avoid regular inspections because they worry about the cost of repairs if the inspection identifies a problem. However, most problems found during routine inspections are relatively simple and affordable fixes, but if left unchecked, these minor issues have the potential to result in a complete and costly failure of the OSS. These knowledge gaps and assumptions can pose barriers to homeowners and impact progress towards proper OSS management. 

Increasingly severe weather or climate events

• Floods, heavy rainfall, atmospheric rivers, severe king tides, and sea level rise are currently impacting the function of an OSS and the ability to repair an OSS if it has failed[2].

What other actions can we take?     

• Ensure LHJs have adequate, steady, and sustained funding and staffing each state fiscal year.
• Ensure LHJs have the capacity to train and retain staff who can implement a robust O&M program that educates homeowners on available resources, proper OSS maintenance, and state/local regulations.
  
• Expand financial incentives for homeowners to properly maintain their OSS by complying with routine maintenance requirements.  
  
• Expand access to loans and other funding sources for OSS repairs, replacements, replacements, and upgrades. 
  
• Identify priority areas to connect to sewer lines, implement a community OSS or a large OSS (between 3,500-100,000 gallons of flow per day). 
  
• Reduce costs associated with and provide funding for establishing connections to sewers where appropriate and where OSS pose an issue. 
  
• Address the needs called for by Local Integrating Organizations (LIOs) in OSS LIO Action Plans.  
  

[1] Schneider, L., Glasoe, S., Story, C., Hofstad, L., Thomas, J., Washington State Department of Health, Skagit County Health, BH Consulting, & Washington On-Site Sewage Association. (2016). Puget Sound Septic System Management Programs Best Management Practices Reference Manual. https://doh.wa.gov/sites/default/files/legacy/Documents/Pubs/332-166.pdf. 

[2] US EPA, "Septic Systems - What To Do After the Flood," https://www.epa.gov/ground-water-and-drinking-water/septic-systems-what-do-after-flood.