Septic Systems

Types of Projects
The Yakima Health District on-site sewage program is responsible for ensuring threats to public health from sewage exposure are kept to a minimum. This program ensures that septic systems are designed, installed, and maintained properly, to protect ground and surface water.

Program functions include:
  • Site evaluation and review for suitable soil and existing lot features
  • Permit Issuance for all new, altered, and repaired systems
  • Final construction inspections
  • Short plat, special property use, and boundary line adjustment review
  • Certification of pumpers and installers
  • Enforcement of WAC 246 - 272A
  • Mortgage review for home sellers and purchasers
Download the Health District's list of Licensed Designers and Installers (PDF) in Yakima County.

Alteration
An alteration permit is issued for changes the owner wishes to make to an existing drainfield that is functioning properly and shows no signs of failure.

Existing System Evaluation
An Existing System Evaluation is used to determine the size, type, suitability, and location of an existing septic system when the Yakima Health District (YHD) has no record of the septic system (i.e. system installation predates record keeping, system installed without permit, etc.)

New Septic System
A new system permit is generally issued for vacant lots that have proposed new building projects requiring on-site sewage systems.

Repair
A septic system is considered “failing” if 1 or more of the following exists:
  • Surfacing sewage
  • Sewage backing up into a structure
  • Sewage leaking from a septic tank, pump chamber, or collection system
  • Inadequately treated sewage contaminating ground water or surface water
If 1 or more of these conditions exist the system must be replaced or repaired.

Plat Review
A Plat Review is completed when an existing lot is divided or lot lines are moved or adjusted.

Site & Soil Evaluation
The first step in determining whether a lot or parcel of land is “build-able” is to have a Site and Soil Evaluation (PDF) done (also known as soil certification, percolation test, check test holes).