Help/Assistance

For assistance information and materials please visit http://www.doh.wa.gov/LOSS.

Other sources of help, information, and references:

Helpdesk phone:

Tumwater: 360-236-3330; or 1-800-525-0127 or TTY users dial 711

Subject matter expert contact information:

564-233-9246

wastewatermgmt@doh.wa.gov

On Site Sewage System, Large, Operating Permit

(From 3,500 to 100,000 gallons per day)
Description/Purpose

Department of Health (DOH) reviews engineering plans, design and construction documents, and installation for on-site sewage systems that treat residential-strength sewage with a peak daily flow, at any common point, from 3,500 to 100,000 gallons. DOH issues approvals and annual operating permits to ensure that sewage is properly treated and public health and the environment are protected over the long term when a large on-site sewage system (LOSS) is used.

Housing subdivisions, small communities, mobile home and recreational vehicle parks, schools, and light commercial developments that are located outside of areas served by public sewer systems often treat sewage and disperse the treated effluent on the property where it originates, or nearby. Treatment occurs in a septic tank or by another treatment system and in the subsurface drainfield. Use of a LOSS must be consistent with local land use planning.

Design and construction submittals must be prepared by a registered professional engineer licensed under Chapter 18.43 RCW.

LOSS receiving state or federal construction grants under the Clean Water Act will undergo a co-review and approval of planning, design and construction documents with Washington Department of Ecology.

Other Related Reviews and Permits

On-site sewage treatment for small systems (with a peak daily flow of less than 3,500 gallons) is reviewed and approved through the local health jurisdiction in the county where the property is located. Biosolids permits, if needed, are issued by Department of Ecology. Local health jurisdictions are responsible for reviewing and approving sludge utilization projects.

Sewage containing industrial waste must be permitted by Department of Ecology, regardless of treatment and dispersal methods and flow volume. On-site sewage systems that discharge directly to surface water, and those that discharge to ground through a drainfield, where groundwater is in hydraulic continuity with surface water, are regulated and permitted by Ecology.

Triggers and activities which would require this permit

An operating permit is needed for installation and operation of LOSS to treat residential-strength sewage through septic tanks or other treatment processes and dispersal through drainfields when there is a peak daily flow, at any common point, between 3,500 and 100,000 gallons per day.

Costs/Fees
see details
see details

There are project and permitting fees for this permit. The fee schedule can be found under WAC 246-272-3000.

Prepared from information and data submitted for calendar year 2024.

Application Information

The application is called 'Large On-site Sewage System Operating Permit Application' is online and can be accessed at https://doh.wa.gov/community-and-environment/wastewater-management/loss-program/loss-guidance.

The project review submittal form for a new LOSS must be accompanied by a check for $800, which is the initial review fee.

The owner of a proposed new LOSS submits the first operating permit fee based on the department’s design flow approval.

The annual operating permit fee and renewal fee must accompany the applications.

DOH will determine the permit fee for an existing LOSS with no prior DOH permit based on information received in the application and will invoice the system owner.

For new LOSS, the operating permit won't be issued until the design and specifications are reviewed and approved. The permit conditions will be based on the LOSS rule, Chapter 246-272B WAC, to protect public health and the environment. One component of the project submittal is proof of consistency with local government planning. The project may also have to meet the requirements of the Department of Archaeological and Historic Preservation, since excavation will occur.

The permit for an existing LOSS with no DOH permit will contain similar operating requirements as a permit for a new system, and may include submittals dates for items such as engineering inspection and evaluation documents, a record drawing, and operations and maintenance manual.

All Operating Permit Applications: wastewatermgmt@doh.wa.gov

All Payments follow online payment guide: https://doh.wa.gov/sites/default/files/legacy/Documents/Pubs/337-170.pdf

The LOSS operating permit is valid for one year after the issue date and must be renewed annually.

Approval to construct or modify a LOSS is valid for 2 years. If it expires before construction begins, all process approvals become void, as does the operating permit. The owner may submit a written request for a single extension of up to two years before the original approval expires. The pre-construction operating permit is valid for one year and must be renewed annually.

An applicant or permit holder contesting a departmental decision regarding a permit, certificate, approval, or fine may file a written request with DOH for an adjudicative proceeding. Third parties aggrieved by permit decisions for a LOSS with peak daily flow over 14,500 gallons may also file a written request for an adjudicative proceeding. Such an adjudicative proceeding will be consistent with Chapter 34.05 RCW. For details and deadlines, see WAC 246-272B-08200 and WAC 246-272B-08300.

Agency Analysis
5
n/a
n/a
3
n/a
3
n/a
0
0

No backlog.

Prepared from information and data submitted for calendar year 2024.

Permit Timeliness Results

Permit Timeliness data collection is in response to a State Auditor’s Performance Audit and RCW 43.42A. Each regulatory agency developed a plan to improve permit clarity, predictability, and timeliness. Each agency considers the customers experience to ensure permit assistance is simple to use, easy to access, and designed in a customer-friendly manner. Agencies report progress to the Governor’s Office for Regulatory Innovation and Assistance (ORIA). ORIA prepares and distributes reports, with participation from the State Auditor’s Office and Results Washington. See latest report here: https://www.oria.wa.gov/ORIA-2020-PermitTimelinessProgressReport.pdf.

Estimated Time Required By the Agency to Process a Permit Application (Definition)
Average days from Receipt to Complete: 3
Maximum days from Receipt to Complete: 21

Estimated Time Required By the Agency to Issue a Permit Decision (Definition)
Average days from Complete Application to Decision: 28
Maximum days from Complete Application to Decision: 161


(Summary results based on 562 submittals in 2024)

Published Decision Time
n/a

Within 30 days of receipt of complete operating permit application and all required fees.

Prepared from information and data submitted for calendar year 2024.

Legal authority
Schematic
View the schematic
Notes / Comments

More information is online and can be accessed at https://doh.wa.gov/community-and-environment/wastewater-management/loss-program/loss-guidance .

Application Information:

The form for project review and approval for a new LOSS, which is called "Project Submittal Form", is online at Project Submittal form for Large On-site Sewage System (LOSS) (Word) . The application for an existing LOSS with no prior DOH operating permit will be sent to the owner by DOH. Contact the LOSS program to obtain the form.

The application for a first permit for a proposed LOSS, which is called "Operating Permit Application, Large On-site Sewage Systems", is online and can be downloaded as a Word document at Operating Permit Application . The application for the first permit is not required until DOH approves all of the required project submittals. DOH sends the application and invoice for renewal of a LOSS permit to the owner 75 days prior to the permit’s expiration date.

For more information, contact DOH, Office of Environmental Health and Safety, Wastewater Management Section at (360) 236-3330 or at wastewatermgmt@doh.wa.gov.

Contacts
Department of Health, Division of Environmental Public Health
Wastewater Management Section
101 Israel Rd SE
PO Box 47824
Olympia WA 98501
Email: wastewatermgmt@doh.wa.gov
Website: https://doh.wa.gov/
Telephone: (360) 236-3330
Triggering Questions
  • Will you be installing an on-site sewage treatment (septic) system and drainfield with a peak daily flow between 3,500 and 100,000 gallons of residential-strength sewage?
* Credential details last updated 7/22/2025
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