Environmental Health

Land Development

We help ensure a safe and reliable source of drinking water and appropriate sewage disposal.

Artboard 1 copy 9

Land Development: Onsite Septic Systems

When applying for certain permits or certificates with Whitman County Building and Planning Division, Whitman County Public Health may be required to complete a Land Development Review to sign off on applications.

Whitman County Public Health looks at a variety of factors in our Land Development Review, including the following:

  • Drinking water quality: View our Drinking Water page for more information
  • Soil type
  • Waste water disposal: View our Onsite Septic page for more information.
  • Site restrictions (minimum lot size & OSS installation options)

Land Development Review Process for Onsite Septic Systems

Applications from Whitman County Building and Planning Division that may require Whitman County Public Health to sign off include building permits, Rural Housing Certificates and short plats. Depending on the presence or absence of an OSS system, the review process will look different.

Current OSS, undergoing Rural Housing Certificate or short plat process:

Whitman County Public Health requires a system assessment from a Licensed Evaluator.

View our Onsite Septic page for more information on how to begin the system assessment process.

Should the evaluation determine the OSS is failing, it will need to be repaired prior to any further development.

Current OSS, applying for a building permit to expand home's capacity:

The OSS must be able to support the increase in flow.

For any alterations or modifications to an existing OSS, contact Whitman County Public Health for more information.

No existing OSS, undergoing the Rural Housing Certificate or short plat process:

It is likely that a site evaluation will be needed to begin the permitting process.

View our Onsite Septic page for more information on site evaluations and how to begin the permitting process.

The results of the Site Evaluation determines the minimum lot size, and if an OSS can be installed at the location.

Land Development: Drinking Water

Visit the Department of Ecology below for information on well construction & licensing information, and contract with a licensed well driller.

Proof of Safety for Wells

Once a drinking water source is established, Whitman County Public Health requires the water be tested for Nitrate and Total Coliform to ensure safety.

Test results from an accredited lab must be sent to Whitman County Public Health before permits are issued. Results must indicate that the drinking water source is safe.

Information last updated on
Dec 2, 2022