Water quality combined funding program

Our Water Quality Combined Funding Program funds projects that improve and protect water quality throughout Washington. The program combines grants and loans from state and federal funding sources (current funding cycle). We also provide technical assistance to program applicants to help them navigate this process.

We use a single, streamlined process for the Water Quality Combined Funding Program: one funding cycle, one application, one competitive review, and one list of funding offers. Applicants only need to submit one application to be considered for all available funding sources under the program.

Funding cycle

  • Amount of funding available: Varies based on the state budget — ranges from $100 million to $200 million annually
  • Grant award limit: Varies depending on funding source and project type. See the current funding year guidelines below for more information
  • Amount of matching funds required: Depends on the funding source you receive; can be up to 25% match required.

Applications are not being accepted at this time.

State fiscal year 2027 applications were accepted July 22, 2025 – September 3, 2025. The 2027 draft offer list is available. The final offer list will be available by July 2026.

State fiscal year 2028 applications will be accepted August 11, 2026 – September 30, 2026, 5 p.m. Funding guidelines and more information are coming soon.

Funding cycle timeline for state fiscal year 2028

Activity Date
Submit application Aug. 11, 2026 – Sept. 30, 2026

Evaluate, rate, and rank applications

Oct. 2026 – Dec. 2026

Publish draft offer list Jan. 2027
Publish final offer list
Begin agreement development
July 2027

Funding is available for the following entities:

  • Counties, cities, and towns
  • Tribal governments (federally recognized)
  • Special purpose districts
  • Conservation districts
  • Nonprofit organizations (only those that qualify for section 319 grants)

Find detailed eligibility information for each project category in the applicant workshop presentations (see below) and the funding guidelines, Chapter 2.

  • Wastewater facilities
    • Planning, design, and construction for sewer collection systems, treatment plants, combined sewer overflows (CSOs), and reclaimed water facilities
    • Wastewater funding requirements provide expectations and resources for funding recipients.
  • Stormwater facilities and activities
  • Nonpoint activities
    • All nonpoint projects must implement an element of a state or local water quality-focused plan, such as a watershed management plan, nonpoint source pollution control plan, Salmon Recovery Plan, Orca Recovery Plan, or Total Maximum Daily Loads (TMDL)/Straight to Implementation (STI). 
    • Nonpoint funding requirements provides expectations and resources for funding recipients.
  • Onsite sewage systems (OSS)
    • Planning, design, and construction of large onsite sewage systems
    • OSS pollution identification and survey programs
    • Local loan programs for OSS repair and replacement
    • Composting toilet systems
    • On-site sewage system projects provides more information for funding recipients.

More information about this funding program

Applicant workshop resources

Save the dates for the 2026 applicant workshop series August 4-6, 2026. These workshops will cover how to apply for state fiscal year 2028 funding. Registration information is coming soon.

  • Stormwater projects:  August 4, 2026
  • Nonpoint and onsite sewage system projects:  August 5, 2026
  • Wastewater projects:  August 6, 2026

Applicant prep tools 2025

Applicant workshop presentations 2025

Loan interest rates for state fiscal year 2027

  • 30-year loans have a 3.3% interest rate
  • 20-year loans have a 2.5% interest rate
  • 5-year loans have a 1.2% interest rate