Onsite Wastewater Treatment System OM&M Program

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Operation, Monitoring, & Maintenance Requirements for OWTS


 septic.example checklist-2023731__340  occupation-2450711__340 quality-control-571149_960_720


Why is an OM&M Program important?

Wastewater is full of viruses, bacteria, pathogens, and chemicals that could be harmful to the health of the public and the environment. Wastewater treatment is a process used to remove these contaminants and convert it into an effluent that can hand on waterbe returned to the environment's water cycle with minimum impact. 

Onsite Wastewater Treatment Systems (OWTS; also known as "septic systems") treat domestic sewage/wastewater directly on the site. When septic systems do not work properly, it could create a public health hazard and/or an environmental nuisance. The Operating Monitoring & Maintenance (OM&M) Program is important to operate, monitor and maintain all types of septic systems properly to assure that they continue to operate as designed; protect the public health and the environment; and provide economical, dependable, long-term service to their owners.

The specific OM&M requirements in the Yolo County Manual apply only to septic systems installed or repaired after July 2016. Owners of existing systems, especially existing supplemental treatment systems, are encouraged to voluntarily opt into the OM&M Program. 

approved-151676__340However, please understand that all owners of an OWTS are operators of that wastewater treatment system. They have the responsibility of proper operation, monitoring, and maintenance of the OWTS to assure a long functional life of the system and the protection of people and the environment. 

Are OM&M requirements the same?

No. Each OWTS is designed based on soil type and structure, type and volume of wastewater flow, and site characteristics and/or restrictions. For the different types of systems, please visit our Types of OWTS webpage. Because there is a wide range of types of OWTS, from simple to very complex, OM&M requirements can be very different. The OM&M is based on the type of OWTS and/or any additional permit conditions from our office. However, one thing is the same: the OM&M of all types of OWTS are important to prevent premature and expensive replacement/repair, and to extend the lifespan of the OWTS. 

For general OM&M that apply to most OWTS, please see Septic Systems FAQs and Maintenance Facts handout.

The following table summarizes OM&M requirements based on type of OWTS. (For complete OM&M Requirements, please refer to the Yolo County OWTS Manual)

(septic tank to gravity dispersal system)

Owner Education. YCEH database records managements. Owner's manual and maintenance checklist.
OM&M Handout.

(septic tank to PD distribution system)

Owner Education. YCEH database records managements. Owner's manual and maintenance checklist.
Operating Permit and Notice on property deed may be required.
PD System OM&M Handout.
MOUND SYSTEM, STEEP SLOPE, RAISED SAND FILTER (not designed for supplemental treatment) Owner Education. YCEH database records managements. Owner's manual and maintenance checklist.
Operating Permit and Notice on property deed may be required.
Mound System OM&M Handout.

Owner Education. YCEH database records managements. Owner's manual.
Operating Permit, Notice on Property Deed.
Ongoing inspection and maintenance by qualified Service Provider, annual Report.
Supplemental: Proprietary Unit OM&M Handout.
Supplemental: Intermittent or Recirculating Sand Filter OM&M Handout.
Drip Dispersal OM&M Handout.

 Non-residential System, including non-residential graywater. Any combination of the above depending on the size, complexity and location of the system.


What is an Operating Permit and why do I need one?stamp-2114882__340

An operating permit is an administrative document issued annually by YCEH that authorizes the initial and/or continued use of an alternative system in conformance with the provisions of the Yolo County Ordinance and YCEH OWTS Manual. It is intended to aid in verifying the adequacy of the OWTS performance of both general and specific conditions of use, thereby protecting groundwater, the public and the environment. An operating permit may also be required for circumstance other than an alternative system as provided in the manual, where in the opinion of YCEH the type, size, location, strength or effluent or other details of a particular system and/or wastewater activity warrant the additional level of oversight provided by a permit.  

How do I get an Operating Permit? What is the procedure?

If you have an alternative OWTS that requires an operating permit, there are two (2) YCEH documents that are required to be recorded at the Yolo County Recorder’s Office prior to the final of the OWTS Installation Permit:

The following outlines the general process to complete this requirement:

  1. Obtain a copy of the Parcel Legal Description for the Notice on Property Deed form.
    • This is page 4 of the Notice on Property Deed form and it is required.
    • A copy can be obtained from the Recorder’s Office, or from your records.
  2. Submit to YCEH the following:
    • A complete Operating Permit Application and annual Fee:
    • A complete Notice on Property Deed.
  3. YCEH returns a signed copy of the approved Operating Permit Application and a signed/complete Notice on Property Deed form.
    • To accelerate this step, please schedule an appointment with your OWTS inspector.
    • YCEH will review and conditionally approve the Operating Permit application. The permit may have conditions based on the type of OWTS installed.
    • YCEH will complete and sign the Notice on Property Deed form.
  4. Obtain a notarized signature on the Notice on Property Deed form.
    • This can be done at the Building Division, if a notary is available.
  5. Record both documents at the Yolo County Recorder’s Office (625 Court St., Ste B01, Woodland).
    • Obtain a copy of the recorded document from the Recorder’s Office at this time.
  6. Submit a copy of the recorded documents to YCEH for the file.

My annual Operating Permit is about to expire. What do I do?

An operating permit is valid for only one year. Close to expiration, you will receive a YCEH invoice with a reminder of your permit conditions, to include a Service Provider Report. Prior to the expiration date of the Operating Permit, YCEH will need the following:

  • Payment for Operating Permit
  • Service Provider Report - YCEH will review for compliance.
    • If the report shows that the OWTS is not functioning as designed, and not meeting the conditions of the permit and/or the YCEH Manual, immediate corrections will be required.

Once a satisfactory Service Provider Report is received, and the annual fee has been submitted, an annual Operating Permit will be issued and mailed to you.

YCEH is responsible for reporting OWTS program data to the California Regional Water Quality Control Board (RWQCB) annually to verify the continued protection of groundwater in Yolo County. The OM&M reporting results are included in this data. Please see the figure below to understand the relationship between the parties involved in the OM&M program:




Additional Septic Information from other sources:


OM&M Pictures:   

Registered Septic Tank Pumper pumping a septic tank.

Cleaning septic tank effluent filter.
To be done at least 2 times a year.

cleaning filters
Service Provider cleaning media sheets of a supplemental
treatment proprietary unit.

Service Provider checking and cleaning a large
effluent filter.