Skip to main content
close

KingCounty.gov is an official government website. Here's how you knowexpand_moreexpand_less

account_balance

Official government websites use .gov

Website addresses ending in .gov belong to official government organizations in the United States.

lock

Secure .gov websites use HTTPS

A lock lock or https:// means you've safely connected to the .gov website. Only share sensitive information on official, secure websites.

King County Logo
Jun
03

Disposal costs

Information on the 2025 rates and fees to dispose of septage at the septage disposal facility at South Treatment Plant.

The 2025 rates and fees to dispose of septage at the septage treatment facility at South Treatment Plant are as follows:

Disposal Rate  $0.1529 per gallon*
 We weigh each load and charge $0.0183333 per pound discharged. This covers domestic septic tank waste and portable toilet waste, up to 2% solids. 

Note: the disposal rate includes 1.0 cent per gallon on-going surcharge to provide funds for Public Health-Seattle and King County to respond to failing on-site sewage systems (OSS), provide technical support to property owners wit  h OSS, identify and repair prioritized OSS failures, continue “what not to flush” education and outreach, and improve industry reporting.
 Fees Annual fee: $200/year/truck
Initial setup fee: $50/truck

expand_less