Water quality combined funding program

The 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. Applicants will receive technical assistance for help navigating the funding process.

The Water Quality Combined Funding Program uses 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 in 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 currently being accepted.

Applications for state fiscal year 2028 must be submitted before 5 p.m. sharp on Sept. 30, 2026.

Start date: Aug 11, 2026
End date: Sep 30, 2026

Funding cycle timeline for state fiscal year 2028

Activity Date
Applicant workshops Aug. 4-6, 2026
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 prep tools

Applicant workshop presentations from August 2026

Loan interest rates for state fiscal year 2028

The following interest rates will apply to most projects:

  • 5-year loans have a 1.4% interest rate
  • 20-year loans have a 2.8% interest rate
  • 30-year loans have a 3.7% interest rate