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Why jetting is not recommended as a permanent repair on old gravity systems

Introducing a high pressure water stream to clear obstructions in septic pipes may appear to be an inexpensive way to repair the septic system; however it can lead to costly problems in the long run. It can decrease the wastewater treatment, damage the septic pipe and shorten the life span of the system.

Rules for jetting septic systems in King County

As of June 2016, the only circumstances where jetting will be considered for property transfer inspections are as follows:

  • For pressurized systems using small diameter PVC pipe
  • For gravity systems with rigid 4” diameter PVC pipe

In order for jetting to be considered for gravity systems, a repair proposal must be submitted by a master installer, designer, or professional engineer with a comprehensive evaluation of the conditions of the system by considering its age, life expectancy, vertical separation and the treatment level required for protection of ground and surface water quality.

Jetting will not be allowed for the following:

  • Concrete or clay tiles
  • Flexible PVC pipes
  • Septic systems without a record drawing
  • Old septic systems at the end of their expected lifespan

Jetting an older septic system will not increase the quality of sewage treatment and potentially harms the quality of ground water and surface waters. Therefore, work with a licensed professional who can repair your system to function properly.

Financial assistance

The Craft3 Clean Water Loan Program offers affordable loans to repair or replace failing on-site sewage systems. The loan program is available throughout King County. Learn more about this program as well as other funding resources.