Environmental Health

Onsite Septic

Healthy septic systems are good for your family, your wallet and the environment.

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Onsite Septic Systems (OSS)

Think of onsite septic systems like a sewage treatment plant, only much smaller. They store, treat and dispose of the things you flush or send down drains. There are many different types of systems. Some are simple, using only a tank and a drainfield. Others are more complex, requiring pumps, filters, or specially designed materials.

New Onsite Septic Systems

Building, splitting, or altering your property?

​If you are developing your land, you may need to schedule a site evaluation with Whitman County Public Health to begin the permitting process.

Details on the permitting process are included in-detail below.

Current Onsite Septic Systems

Buying or selling property with a septic system? ​

A System Assessment Form, linked below, completed by a Licensed Evaluator is required prior to property transfer.

Program Application

To submit a System Assessment, submit an online System Assessment Form.

System Assessment Form

If wishing to complete the form by hand, download, print and email the System Assessment Form to EH@whitmancounty.net.

Onsite Septic Permitting Process

Step 1: Site Evaluation

  • Submit the Site Evaluation Application, linked below. An WCPH Environmental Health Specialist will contact you to schedule a site evaluation.

Program Application

To request a Site Evaluation, complete an online Site Evaluation Application.

Site Evaluation Application

If wishing to complete the application by hand, download, print and email the Site Evaluation Application to EH@whitmancounty.net.

  • At site evaluation, soil conditions and any site restrictions will be identified. Drainfield requirements will be presented based on project.
  • Site Evaluation Reports are good for 3 years and are project specific.

Step 2 — Design & Install

Program Application

To begin the permitting process, submit an online OSS Permit Application.

OSS Permit Application

If wishing to complete the application by hand, download, print and email the OSS Permit Application to EH@whitmancounty.net.

  • Setback Requirements may be a helpful resource.
  • Once the design is approved and all fees are paid, a Construction Permit will be issued. Building permits cannot be issued until a Construction Permit is issued.
  • Schedule a final inspection before covering the system​.

Step 3 — As-Built Drawing and Final Permit

  • Submit an As-Built drawing at the time of the final inspection.
  • An Operational Permit will be issued once the system is approved. Certificate of Occupancy cannot be granted until an Operational Permit is issued.

Step 4 — Maintenance

  • Every 3 years, hire a Licensed OSS Professional to pump and evaluate your tank.
  • Return the System Assessment Form to Whitman County Public Health for record keeping.

Program Application

To submit a System Assessment Form, complete an online System Assessment Form.

System Assessment Form

If wishing to complete the form by hand, download, print and email the System Assessment Form to EH@whitmancounty.net.

Become a Licensed OSS Professional

Licensed Installer, Pumpers, and/or Evaluators

Licensed installers, pumpers, and/or evaluators are those qualified to do the following:

  • Installers: Install septic systems in Whitman County, including residential gravity, residential alternative, and commercial systems.
  • Pumpers: Pump septic systems in Whitman County
  • Evaluators: Evaluate septic systems in Whitman County, including locating septic tank and drainfield location and evaluating their condition

Installers, pumpers, and/or evaluators are required to submit an application for approval. Pumpers must disclose the number of pumping vehicles, dispatch locations, storage location and name and location of dumping facility.

Program Application

To apply for approval, submit an online Installer, Pumper & Evaluator Application.

Installer, Pumper & Evaluator Application

If wishing to complete the form by hand, download, print and email the Installer, Pumper & Evaluator Application to EH@whitmancounty.net.

Become an Out-of-County Installer & Pumper

Out of County Installers & Pumpers are those licensed to install and/or pump septic systems in another county in Washington State. By submitting the Out of County application, these professionals may receive a one-time installation and/or pumping permit for work in Whitman County.

Program Application

To apply for out-of-county approval, submit an online Out-of-County Installer & Pumper Application.

Out-of-County Installer & Pumper Application

If wishing to complete the form by hand, download, print and email the Out-of-County Installer & Pumper Application to EH@whitmancounty.net.

Qualified Design Professionals

Qualified Design Professionals are those qualified to design septic systems in Whitman County. Professional Engineers, or those with a Washington State Professional OSS Designer License.