Well & On-site Sewage Disposal Program
The Well & Septic System Program:
Sewage disposal and a safe, plentiful drinking water supply are often taken for granted. Yet the presence of contamination in drinking water, an insufficient water supply, or improperly disposed sewage can have a significant impact upon our health and quality of life. The well and septic system program goals are to protect surface and groundwater from contamination so that a safe, plentiful supply of drinking water can be obtained and maintained; and to assure that sewage can be, and is, disposed of in such a manner so as not to create a public health hazard, or pollute the environment.
Wells and On-Site Sewage Disposal Program
The Environmental Health Division conducts or oversees evaluations of the site and soil to determine the best design for the septic system to assure proper disposal of sewage. Site evaluations, plan reviews, permit issuance, and construction and destruction inspections are also conducted for on-site sewage disposal systems and wells pursuant to the California Well Standards and Solano County Code Chapter 13.10 and 6.4.
Information available at the County Division of Environmental Health on the construction and maintenance of wells and septic systems:

Sewage Disposal

Professional Resources
Wells and on-site sewage disposal systems may be installed, repaired, or modified by a properly licensed contractor. Homeowners may also install their own sewage disposal systems provided they are familiar with pertinent County regulations.

The following lists of licensed professionals are available from Environmental Health Division:
Alternative Systems
Alternative sewage disposal systems are specifically designed to accommodate sites with limiting conditions that preclude the installation of standard disposal fields. These systems require design by a properly licensed engineer, Certified Engineering Geologist, or Registered Environmental Health Specialist. A list of licensed professionals with experience in designing alternative systems within Solano County is available at Registered Septic Design Consultants. Properly licensed professionals may also be found by consulting the yellow pages. 

Graywater Systems
Graywater is defined as untreated wastewater that has not been contaminated by any toilet discharge, has not been affected by infectious contaminated or unhealthy bodily wastes, and does not present a threat from contamination by unhealthful processing, manufacturing, or operating wastes. Graywater includes waste water from bathtubs, showers, bathroom washbasins, clothes washing machines, laundry tubs, but does not include wastewater from kitchen sinks, or dishwashers. The regulations concerning graywater can be found at Graywater Regulations.

California graywater systems are separated into three categories, each with different permitting requirements:

  1. Single Fixture or Clothes Washer-- No Permit required if no cutting of existing plumbing
  2. Simple System --Discharge capacity is 250 gallons per day or less
  3. Complex System--From Multifamily or multidwelling unit with discharge capacity greater than 250 gallons per day

Requirements for construction permits:

  • Applies to all Simple and Complex Systems within the unincorporated portions of the Solano County. For residents within city limits contact the applicable City Building Department. 
  • Design shall be based on the location, discharge capacity, soil type, and groundwater level
  • The discharge area must be on the same parcel as the source, unless lawfully exempt
  • No construction shall occur until plan is approved by Building and Environmental Health Divisions
  • All applications shall include plot plan of the site including existing grading, existing equipment, areas of landscaping, septic system including disposal field and reserve area, existing water supply (well) including water lines.
  • Application shall include diagram of location of  proposed graywater systems including tanks, and disposal areas
  • Equipment list including cut sheets all equipment and specifications for installation
  • Cross -Connection Devices (for systems with pumps/ pressurized)
  • Internal backflow devices
  • All components must be water tight
  • Label graywater disstrbution piping up stream of connection to an irrigation or disposal field as CAUTION: NON POTABLE WATER DO NOT DRINK. These marking shall be at intervals not to exceed five feet.
  • Preparing and maintaining an Operation and Maintenance Manual for life of the graywater system that is transferred with change in occupancy to the new owner/tenant. 
  • Must be inspected by Building and/or Environmental Health Division.  See Environmental Health Division Graywater Fee at Environmental Health Fees

All graywater systems have the following prohibitions:

  • No connection to a potable water system
  • No diaper wash water or contact with any fecal material
  • The discharge point must be covered by 2 inches of material such as mulch, rock, soil) or solid shield covers.
  • No use of graywater for spray irrigation
  • No run off from desired discharge location
  • No discharge to storm sewer
  • No discharge to surface body of water
  • No ponding of graywater
  • No use of graywater for irrigation of root crops or edible portions of plants touching soil.
  • Minimize contact with humans and pets
  • No discharge of hazardous materials including but not limited to, oily rags, wastewater from home photo developing, cleaning of car parts, soiled or infectious garments, woodworking, or home occupational activities


These links are provided for information only and shall not be considered as endorsements or recommendations of Solano County.