Septic Systems

Sewage disposal is required for any home or structure inhabited by people. Onsite sewage disposal systems (OWTS) provide sewage disposal for homes/structures located in areas that do not have community sewer systems.

Incorrectly installed OWTS can harm water quality and put people at risk.  

The location and construction of OWTS must be approved and permitted by the County of Marin EHS. Therefore, prior to building a home or structure dependent on an OWTS, EHS approval and an OWTS permit is required prior to the issuance of a building permit. The permit process includes a site review and percolation tests documented by EHS. An EHS OWTS permit is also required for any repairs, modifications, or replacements to a system.

The information below contains specific information related to site review and various OWTS permits. If you have questions or need further information, please call (415) 473-6907 or come by our office for assistance.

Applications

• Application for site review, construct and operate an OWTS (or repair; replace), construct an alternative system, tank abandonment, minor modification, office/field consultation.

Procedures for Abandonment of Septic Tank after Issuance of Permit

• Procedures for Abandonment of Septic Tank after Issuance of Permit

Fees

• EHS Septic Program Fee Schedule

Marin County Regulations

• Standard Septic Systems Regulations Adopted May 2008 
• Alternative Septic Systems Regulations Adopted May 2008 
• Marin County Regulations Code Chapter (Titles) 18.06 and Chapter 18.07

State of California Regulations

AB885 – Water Quality Control Policy for Siting, Design, Operation, and Maintenance of Onsite Wastewater Treatment Systems

• AB885 Regulations and Environmental Impact Report on State wide regulations
• AB885 FAQs August 2013

To determine if a property is within 600 feet of a 303(d) federal listed impaired water body, the address can be entered at OWTS Map. The map is a helpful tool to determine proximity to a water body. A more precise measurement may be required to verify the actual distance to the water body.

On September 27, 2000, Governor Gray Davis signed into law, Assembly Bill 885 that required the State Water Resources Control Board (SWRCB) to adopt standards or regulations for the permitting and operation of onsite waste water systems (OWTS). On June 19, 2012, the State Water Resources Control Board (SWRCB) approved Resolution No. 2012-0032, adopting the Water Quality Control Policy for Siting, Design, Operation, and Maintenance of Onsite Wastewater Treatment Systems (OWTS Policy). This Policy establishes a statewide, risk-based, tiered approach for the regulation and management of OWTS installations, repairs, replacements, and modifications, and sets the level of performance and protection expected from OWTS.

If the current OWTS (septic system) is functioning properly and wastewater is not surfacing, there are no immediate impacts to property owner. Even if the OWTS is malfunctioning, the Policy may not affect the property owners. Only properties that are within 600 feet of a federally-listed impaired water body (303d) will have different requirements (Tier 3) for repairs, replacement, modifications, or new OWTS. (See Tier 3 described in #9.) Properties within the county and not within 600ft to an impaired water body will only be subject to current county regulations and policies.

Policies

• Septic System Residential Improvement Policy - This policy provides guidance for property owners who wish to improve, remodel, or add on to residences which are served by onsite wastewater systems.

Performance Evaluation Guidelines

The guidelines purpose of a performance evaluation is to determine whether an existing septic system is functional and meets minimum standards of performance established by the San Francisco Regional Water Quality Control Board (RWQCB) and the County of Marin, Environmental Health Services (EHS). Please review the Performance Evaluation Guidelines which describe information on conducting a hydraulic load and dye test.

The current Residential Operating Permit program requires all alternative systems be monitored at a specified frequency by a qualified professional or County staff. A report documenting the inspection and applicable maintenance performed is submitted. EHS staff is required by the Bay Area Regional Water Quality Control Board (RWQCB) to submit an annual report based on information received in the professionals’ reports.

The operating permit fee charged by EHS, accounts for staff time administering the program; managing records and files; inspecting of a number of alternative systems throughout the year; reviewing the monitoring reports; compiling data and entering it into a database; authoring the annual report for the RWQCB; notifying owners of overdue reports; pursuing compliance; alerting owners to needed corrective action when problems arise with their system; answering owners questions by phone and email; interacting on a regular basis with septic professionals; updating property owner information; and sending out billing notices.

Monitoring

• Self-Monitoring Form for Alternative Septic Systems
• Self-Monitoring Form Instructions
• Professional's Monitoring Form 
• Operating Permit Responsibilities:
  1. Understanding your options
  2. Interpreting your operating Permit
  3. When are reports due?
  4. How my system can qualify for biennial inspections?
• Homeowner's General Information and Preventative Maintenance Tips
• Homeowner's Trouble-Shooting Guide for Alternative Systems 

Fees

EHS Septic Program Fee Schedule - A technology fee surcharge of $10 will be assessed on most permits separately from the permit fee in order to offset County costs associated with the permit tracking system.

• Remodel and Additions Policy - This policy provides guidance for property owners who wish to improve, remodel, or add on to residences which are served by onsite wastewater systems.

If you distribute chemical toilets, or haul and dispose of solid waste from septic tanks and portable toilets, you must be registered by EHS, and renew your license each year.

To apply for a registration complete the application and submit to EHS with the current fee.

• Pumper Truck / Chemical Toilet Application

Fees

EHS Septic Program Fee Schedule - A technology fee surcharge of $10 will be assessed on most permits separate from the permit fee in order to offset County costs associated with the permit tracking system.

Proper maintenance of an OWTS is important to keep your system running smoothly and to potentially save money on repairs. The National Environmental Services Center provides a booklet as a guideline for homeowners and includes maintenance tips, do’s and don’t’s, and a brief explanation as to how an OTWS works.

• Landscaping and Plant Selection Tips
• Homeowner’s General Information and Preventative Maintenance Tips
• Homeowner’s Trouble Shooting Guide for Alternative Septic Systems 
• Septic Tanks and Mosquito Brochure This brochure provides important information regarding septic tank screening to help prevent mosquito breeding. (This information is provided by the Marin / Sonoma Mosquito & Vector Control District. For more information call 1-800-231-3236.)
• Stinson Beach County Water District If you live in Stinson Beach, contact Stinson Beach County Water District 415-868-1333 for information regarding septic permits. They also have do's and don'ts for septic systems and consumer information.

Click on a question to see the answer, or Open All Questions.

• I am looking at buying a piece of raw land. What do I need to do and what is my first step?

  It is recommended that you have a private septic system consultant review the site to determine feasibility of installing a septic system. Qualified companies and individuals who can perform this service can be found by checking local telephone directories or the Internet. Marin County EHS also maintains a list of local consultants and contractors. The consultant you select should be familiar with Marin County codes and requirements.

  When you are ready to proceed, a consultant can help you apply to Marin County for a site review and percolation tests.

• I am developing a raw piece of land. Can I get my septic permit before my building permit? Can I get my septic permit and my building permit at the same time?

  Yes, you may obtain a septic system construction permit prior to the issuance of a building permit. However, the septic system permit will not become valid until the building permit is issued.

  Yes, it is possible to get septic and building permits at the same time, but you need to get the septic permit before the building permit can be issued.

• I am thinking of buying a house that is on septic but there are no septic records. What do I do? Can I remodel?

  Generally speaking, a recently installed septic system which complies with all current Code requirements will be a Class I system.

  Sometimes, due to site conditions, soil depths, setback problems and other reasons it may not be possible to comply with all the regulations in one or more respects. If every effort was made to comply with current Code the system would be classified as a Class II or a system which complies with the Class II Repair standards.

  A Class III system is one which was given a permit by the County under prior Marin County Code (prior to 1984). Note that most, if not all, of these do not meet current septic system regulations.

  Class IV covers two categories of septic system; cesspools - (these are no longer permitted), or other existing septic systems for which no documented records are available.

• How long does it take to get a septic system permit?

  The time frame depends on the complexity of your project and our staff’s current workload. Summer and Fall are the busiest times of the year. Once a design is submitted to us with all fees paid, we try to respond in no more than 2 weeks. Contact EHS staff for a current time estimate.

• How long are perc tests good for?

  Perc tests performed under current regulations and witnessed and documented by EHS may be used until the current percolation regulations are changed, or modified.

• If the property percs OK will I be guaranteed it can be permitted?

  Not necessarily. Due to other factors such as site conditions, soil types and depths, setbacks and other reasons it may not be possible to comply with the Code and allow the issuance of a septic permit.

• My system is a Class III and has a redwood tank and I want to do some remodeling. Will I have to replace the tank? If I have to replace the tank, should I have the system evaluated first?

  A septic evaluation and hydraulic test would be required for any remodel. A redwood tank must be replaced with an approved septic tank under permit. It must be constructed of approved materials, either concrete or fiberglass. Please check the fees for tank replacement.

• How do I calculate the percentage of remodel I am doing when doing an interior remodeling only and not adding any square footage? For example, I want to remodel my bathroom and will only be moving the shower and tub, putting in a new vanity and cabinets.

  Any area that is being remodeled will be computed and divided by the existing square footage. Measure existing permitted habitable space including closets and bathrooms. The measurements should be taken wall-to-wall. Check County Building for further information.

• If I am not adding square footage, or a bedroom, why does it matter to EHS that I am doing interior remodeling?

  County Code requires that EHS approve building permits prior to it being issued. EHS must ensure that the septic system of the house is functioning properly. Onsite systems must be properly operated and maintained to protect groundwater and other drinking water sources, as well as the health of family and neighbors.

• What kinds of remodeling can I do to my house that will not require a septic evaluation?

  Each building permit application received may potentially require a septic evaluation.

  Remodeling projects that do not require a building permit will not require a septic evaluation.

• I had an evaluation of my septic system done by a REHS or Civil Engineer when I purchased the property over a year ago. Will it still be valid?

  We accept septic evaluations conducted within a year prepared by a qualified professional, a Registered Environmental Specialist or Civil Engineer. All others will not be considered.

• Who can conduct an inspection of my septic system for a minor remodel?

  An inspection can be conducted by a County approved Septic System Inspector, a State Licensed Contractor (C-42), a Registered Environmental Specialist, or a Registered Civil Engineer, or a Registered Geologist.

• Can my house be condemned if I cannot repair my system to meet current code?

  EHS staff makes every effort to accommodate septic system repairs. The repairs are tailored to the specific lot and residence. Because of the many factors involved, it is recommended that an EHS Land Use inspector be contacted to discuss your particular situation.

• I am looking at a subdivision that was approved in the past. Will I have to do more percolation tests for that lot?

  Perhaps. The past regulations allowed subdivisions to be approved with a minimum of one soil profile hole and three percolation tests on each lot. Current code requires a total of two profile holes and six percolation tests per lot for a septic permit. Additional percolation tests and/or soil profile holes may be required if the testing was not adequate for the particular lot.

• Does Environmental Health Services inspect the septic system before I purchase the property?

  No. It is recommended that the individual buyer have the septic system evaluated by a qualified professional, either a Registered Environmental Health Specialist, or Registered Civil Engineer, or Registered Geologist.

• Can I renew my permit?

  Yes. Marin County Code Chapter 18.06.080 provides for a two year permit to construct and operate an individual sewage disposal system. This permit is renewable for one additional year only. After that a new application, plans and fees will be required.

• What is an Alternative System?

  An alternative system is generally required for sites where the conditions are not suitable for a standard septic tank and gravity drain field system. Most alternative systems require a pump which distributes the wastewater under pressure.

  For example, if ground water or percolation rates are unsuitable, it may be possible to install a "mound" system. In a mound system, suitable soil is placed above grade to supplement the native soil. The distribution system is installed in the mound. There are limitations and additional requirements for this type of design as well as other approved alternative systems.