•   Septic system for a home (WA Department of Health).

  When septic systems malfunction, improperly treated sewage can surface or move through the soil to groundwater, streams, lakes, rivers, and Puget Sound. Malfunctioning septic systems are a potentially significant contributor of harmful bacteria in freshwater and marine waterways.
• The bacteria can accumulate in shellfish to the point that they may no longer be safe to eat and cause shellfish beds to close to commercial and recreational harvest (see the shellfish beds indicator). Harmful bacteria from septic systems also pose a health risk to swimmers (see the beaches indicator).
• All owners are responsible for taking care of their septic systems. The twelve Puget Sound local health jurisdictions oversee management plans to help owners maintain their systems, and the Department of Health provides additional technical and financial support.
• Marine Recovery Areas, defined by state statute, are designated where septic systems are associated with the degradation of shellfish growing areas (see the Shellfish Beds Vital Sign), marine waters listed as polluted for low dissolved oxygen levels or fecal coliform, or marine waters where nitrogen has been identified as a contaminant of concern (see the Marine Water Quality Vital Sign).
• In Marine Recovery Areas and other designated areas, local health jurisdictions engage more directly with owners to help ensure systems are inventoried, inspected, and maintained to reduce public health risks.
• Since 2011, local health jurisdictions have inventoried more than 79,000 septic systems, 93 percent of which are fully documented. Additionally, more than 40,000 systems (51 percent of the inventory) are up-to-date with inspections. In part due to addressing failing septic systems, 12,059 acres of shellfish beds were reopened to harvest since 2007.

• Management of septic systems is addressed in the Shellfish Implementation Strategy
• Actions proposed in the Action Agenda that advance this Vital Sign (let us know if we missed any!): 
  • Enhanced OSS in Clallam County's MRA Phase 2
  • Enhanced OSS in Clallam County's MRA Phase 3
  • Financing Options for Healthy Onsite Sewage Systems (OSS)
  • Jefferson County On-site Septic System Repair/Abatement Program
  • Penn Cove Water Quality Improvement -Coupeville Sewer Extension
  • Thurston Shellfish Growing Areas OSS Pollution Prevention

• Leadership Council Resolution 2011-16, Adopting a 2020 ecosystem recovery target for on-site sewage systems
• Wastewater and On-site Sewage Systems Targets Technical Memorandum

Articles related to sewage pollution in the Encyclopedia of Puget Sound