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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 septic pipe obstructions may seem like an inexpensive way to repair a septic system, but this can lead to costly problems, decrease wastewater treatment, damage septic pipes, or shorten the system lifespan.


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

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 system that considers age, life expectancy, vertical separation, and 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 properly.