Onsite Wastewater Treatment System Program



AB 885 - Onsite Waste Water Treatment System FAQ

Water Quality Control Policy for Siting, Design, Operation Maintenance of Onsite Wastewater Treatment Systems - Fact Sheet

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Environmental Health Services

 Contact Us

Environmental Health Department
137 N. Cottonwood St. Suite 2400
Woodland, CA 95695

8am-12pm & 1pm-4pm

Phone: (530) 666-8646
Fax: (530) 669-1448

Email: Environmental Health

Sewage Disposal/Liquid Waste

Improper human sewage disposal can cause ground water contamination, pollute streams and rivers, create breeding of nuisance insects, create noxious odors, and contribute to the spread of disease.

Environmental Health specialist issues permits for the installation, repair, and abandonment of domestic sewage disposal systems in order to prevent these problems.

Environmental Health specialist also investigates improper sewage disposal practices as reported by the public. The main enforcement code used by Environmental Health is ordinance 765 the Water Quality Law of the County of Yolo.


 Permit Information

A permit to construct is required from Environmental Health whenever a septic tank is replaced or abandoned, or if leach lines are replaced or repaired.

Permits can be obtained at Yolo County Environmental Health. 

To process the permit, the Environmental Health Specialist will need to know several items regarding the project:The assessor’s parcel number, the location of the house on the parcel, and site soils information (to help determine the leach field size and suitability for septic system installation).

  • A detailed site plan including active or inactive wells, water or drainage courses, landscape contours, structures, property lines, and easements. This information is used to verify compliance with the horizontal distances as required by Yolo County ordinance 765. Approvable Site Plan for Project using Well & Spetic System

Please check the Environmental Health Fee Schedule for the current permit fees. For more information Contact Us.

For our document titled: Guidelines to the Planning, Installation, and Maintenance of Septic Systems in Yolo County.  


 Soil Types

In Yolo County septic systems are sized by determining the type of soil that is present at the location you will be installing your septic system. You can use the Yolo County GIS system to determine what type of soil you have on your property. Click here for detailed direction for using the Yolo County GIS to determine soil type.


Septic Pumper Trucks

Vehicles that pump and haul septage in Yolo County must have a valid permit from Yolo County Environmental Health to do so. Vehicles are permitted and inspected on an annual basis.

Application for Septic Cleaning/Romoval Registration


 Frequently Asked Questions

Who Can I Contact To Work On My Septic System?

Contractors with either a general engineering (A), or plumbing contractor (C-36), or sanitation system (C-42) license are qualified to repair or install septic systems under the regulations of the contractor’s licensing board. The Health Department cannot endorse contractors, however, a list of septic system installers that regularly do business in Yolo County is available by contacting our office.

What Can I Do To Properly Maintain The Septic System?

  • Use minimal amounts of water to avoid overloading the leach field.
  • Don’t dispose of pesticides, solvents, waste oil, anti-freeze or other hazardous chemical into the septic system. Improper disposal of these items can result in fines and expensive clean-up measures.
  • Limit the amounts of grease, food scraps, garbage, and non-biodegradable items going into the septic system.
  • Keep record of the location of the septic tank for future service pumping and have the septic tank pumped routinely by a licensed septage hauler.

Contact Us for a copy of our Septic System Maintenance Guidelines for more important tips.

When Is An Elevated Leach Field Used?

The elevated system is required in areas with high seasonal groundwater or shallow bedrock. It is constructed like an evap-transpiration absorption (ETA) system but placed in mound of soil above normal grade rather than below the ground surface. This is done to allow the sewage to be naturally treated before reaching ground water.

How Do I Abandon A Septic Tank?

Septic tanks are abandoned when they are no longer needed, such as a home connecting to a public sewer system, or when the tank has failed. To abandon a septic tank you must do the following: 

  • A permit from Environmental Health must be obtained prior to starting work.
  • All liquid wastes, scum and sludge shall be pumped from all septic tank compartments and properly disposed of by a permitted Yolo County Septage Hauler.
  • The top of the septic tank must be removed or sufficiently opened up to allow all of the compartments to be filled.
  • The compartments shall be completely filled with soil, sand, gravel, concrete or other approved inert material. All voids are to be filled to prevent future soil settling.
  • The environmental health specialist will inspect the filled tank prior to final backfill. A copy of the septic tank pumping receipt will be required for final sign off of the permit.