SDCI is required to collect King County Sewer Treatment Capacity forms for all new construction projects, including detached accessory dwelling units (DADUs) and attached accessory dwelling units (AADUs). The King County forms were updated. Please confirm you are using the latest version of the fillable PDF forms. 
SDCI is required to collect King County Sewer Treatment Capacity forms for all new construction projects, including detached accessory dwelling units (DADUs) and attached accessory dwelling units (AADUs). The King County forms were updated. Please confirm you are using the latest version of the following fillable PDF forms:
- Residential construction (single-family and multifamily)
- Non-residential construction (commercial/industrial)
- Alternative housing construction (micro housing, adult family home, student dormitory)
For single-family residences, DADUs, and AADUs, please use the residential construction form and check the appropriate boxes. For mixed-use buildings, please complete both a residential and commercial form.
Please complete the correct form(s) with the best-known project information. The owner needs to sign and date the form. You must submit your completed and signed form, through the Seattle Services Portal, before we can process your building permit application.
The updated King County Sewer Treatment Capacity forms can be found on SDIC’s forms webpage.