Wastewater Systems

Reduce and prevent pollutants from wastewater systems (for example, treatment plants and large- and small-scale onsite septic) by improving regulatory controls and incentives and investing in new technology.
Discharges of excess nutrients—particularly nitrogen and carbon—from human sources including domestic wastewater treatment plants (WWTPs) are negatively impacting water quality and contributing to the low oxygen levels in Puget Sound waterways. Low dissolved oxygen impacts the health of aquatic life. Fecal pollution from wastewater systems also impacts water quality and contact with water or consumption of shellfish polluted with bacteria and viruses from fecal pollution can cause illness. In Puget Sound, fecal pollution comes from both point-source origins such as combined sewer overflows as well as non-point source origins such as failing septic systems.

A regulatory strategy includes the recent issuance of a National Pollutant Discharge Elimination System (NPDES) general permit for municipal wastewater nutrient loads for wastewater treatment plants, which were found to contribute to existing water quality impairments in Puget Sound. Implementing advanced treatment technology to fulfill this permit will require developing a funding pathway for wastewater treatment plants to overcome financial barriers associated with major capital upgrades. Existing state and federal funding, including low-interest loans to assist and reduce costs to wastewater utility ratepayers is one element of this strategy, but new funding sources or expanded levels of funding will be needed to support local implementation efforts.

Implementing the Marine Water Quality, Shellfish, and other Implementation Strategies supports the success of this strategy.
  • Reduce nutrients to improve DO
  • Reduce bacteria to protect shellfish beds
  • Reduce inequitable health outcomes

Develop a permit framework for advanced wastewater treatment to reduce nutrient discharge and other pollutants and provide technical and financial support for implementation. (ID #37)

Key opportunities for 2022-2026 include:

  • Implement the Nutrient General Permit;
  • Plan for and implementation of treatment enhancement;
  • Understand opportunities for trading programs.

Increase compliance monitoring, technical assistance, and enforcement to improve wastewater treatment plants’ compliance with discharge limits for disease-causing bacteria and viruses. (ID #38)

Key opportunities for 2022-2026 include:

  • Ensure enough staff capacity and training, monitoring, enforcement, and resources for wastewater treatment plant operations.

Implement priority upgrades of municipal and industrial wastewater facilities in urban and urbanizing areas to reduce disease-causing bacteria and viruses and their effect on Puget Sound. (ID #39)

Key opportunities for 2022-2026 include:

  • Identify and prioritize impacts from outfalls to shellfish beds;
  • Analyze options for reducing flow, better placement, or removal of outfalls;
  • Support upgrades identified for prioritized facilities while considering potential damage to existing habitat (for example, kelp beds) and shoreline areas important to vulnerable populations and underserved communities.

Effectively manage and control fecal pollution and disease-causing bacteria and viruses from small onsite sewage systems (OSS) and larger onsite sewage systems (LOSS). (ID #40)

Key opportunities for 2022-2026 include:

  • Generate adequate funding for sustained local OSS management, program development, implementation, monitoring and enforcement, and to strengthen and standardize local OSS and LOSS management programs;
  • Ensure landowners have access to and are eligible for incentives, loans and other funding sources for OSS maintenance and upgrades.

Prevent and reduce combined sewer overflows. (ID #154)

Key opportunities for 2022-2026 include:

  • Design and upgrade systems to stop combined sewer overflow (CSO) events;
  • Prioritize vulnerable populations and underserved communities;
  • Research and support alternatives to separate combined sewer systems;
  • Reduce water use to avoid the need for upgrades;
  • Promote actions by homeowners and commercial developers that reduce runoff during rain events (for example, rain gardens, retention ponds, street trees, and other green stormwater infrastructure).

Extend centralized sewer systems in areas where conditions are not suitable for onsite sewage systems (OSS). (ID #155)

Key opportunities for 2022-2026 include:

  • Identify sustainable funding sources and prioritize areas where conditions are not suitable for OSS;
  • Support the installation or expansion of centralized sewer systems in areas where conditions are not suitable;
  • Remove barriers for property owners to connect to centralized sewer systems in areas where it is accessible;
  • Ensure alignment with the Growth Management Act.

Promote appropriate reclaimed water projects to reduce pollutant loading to Puget Sound. (ID #211)

Key opportunities for 2022-2026 include:

  • Identify, support, and incentivize efforts to recycle, reuse, or reclaim water (including tertiary treatments) that meets quality performance standards through engineered treatment or through natural infiltration that results in wetland enhancement, groundwater recharge, or increased flows in rivers and streams;
  • Increase funding and technical capacity in this subject area;
  • Promote the use of reclaimed water for irrigation, landscaping, toilet flushing, dust control, and construction-related activities.
Implementation Considerations

Key opportunities for 2022-2026 to integrate human wellbeing considerations and climate change responses into efforts include:

Human Wellbeing

  • Connect impacts from pollutants to local issues to foster community engagement, particularly with communities reliant on the natural environment or ecosystem services for recreational, subsistence, or economic purposes, including tourism, hospitality, aquaculture, or agriculture.
  • Increase educational efforts and access to information for communities and address barriers to engagement in vulnerable populations and underserved communities, particularly the region’s Indigenous and immigrant communities who participate in fishing, shellfish harvesting, and consume more seafood than the wider population.
  • Understand that MWQ issues are both partly caused by and experienced by coastal communities when engaging these communities in planning and implementation actions. For example, residents’ inadequate onsite septic system maintenance can cause nutrient pollution, which can lead to beach closures. Beach closures can limit shellfish harvesting, fishing, or other forms of coastal recreation, which can negatively impact residents’ traditional ways of life and even identity, notably among the region’s Indigenous communities.

Climate Change

  • Factor future climate conditions into incentives and regulatory frameworks for wastewater systems.
  • Incorporate climate change education into technical and financial assistance for landowners about onsite septic systems.
  • Consider climate adaptation when extending centralized sewer systems and making other wastewater infrastructure investments.
  • Acknowledge how the multi-dimensional consequences and experiences referenced in the human wellbeing considerations for this strategy are likely to be exacerbated by climate change further necessitating individual, community, and governance solutions.
Ongoing Programs

Ongoing programs provide regulatory oversight, technical support, implementation resources, funding, or guidance and serve as the critical foundation for Puget Sound recovery. The following is a list of example state and federal ongoing programs that help to implement this strategy. Many more local, tribal nations, and nongovernmental programs exist that support this strategy.

What We're Measuring

We achieve our recovery goals of healthy human populations, healthy water quality, and increasing functioning habitat, thriving species, and food webs by ensuring municipal wastewater discharges of nutrients to Puget Sound meet water quality-based effluent limits and other requirements of the nutrients general permit; ensuring municipal wastewater discharges of disease-causing (pathogenic) bacteria and viruses to Puget Sound meet water quality-based effluent limits; reducing spills of untreated sewage; ensuring onsite septic systems (OSS) are inventoried, inspected, maintained, and operational; ensuring levels and patterns of contamination in fish and shellfish harvested from Puget Sound waters and levels and patterns of pollutants and biotoxins in surface waters do not threaten the health of Puget Sound communities or vulnerable populations. Indicators of success include:

Nutrient balance in marine water
Onsite septic system compliance
Onsite septic system failures
Onsite septic system inventory: documented systems
Onsite septic system inventory: suspected systems

This indicator reports on direct, field-based measurements of the ratio of silicon to nitrogen, at representative spatial and temporal scales for the Puget Sound ecosystem. This will enable an understanding of whether Puget Sound has a nutrient balance that supports lipid-rich diatoms all year round, creating the base of the Puget Sound food web.

Nutrient balance in marine water

No reported data available

Number of onsite septic systems compliant with local inspection mandates

Number of onsite septic systems with unresolved failures

Number of onsite septic systems inventoried with their relevant local health jurisdiction

Number of suspected onsite septic systems without documentation

Onsite septic system inventory: suspected systems

No reported data available

Current Legislative Actions (3 Bills)
2024 | State Bill HB 1365
Related Activity Types
Compliance Monitoring and Enforcement
Related Strategies
11 - Wastewater Systems
Status: Did not pass
2024 | State Bill HB 2290
Related Activity Types
Policy and Regulation Development
Related Strategies
11 - Wastewater Systems
Status: Did not pass
2024 | State Bill SB 6163
Status: Did not pass