Frequently Asked Questions
A septic system is an on-site wastewater treatment system that is needed to treat and discharge household wastewater on properties that do not have access to a centralized collection system and municipal treatment plant. A septic system consists of a septic tank for settlement of solids, floating of grease and oil, to separate a clear effluent to be directed to a soil based disposal field. There are many different types of disposal fields in use in California. The septic tank effluent can be directed to a seepage pit, leach lines, pressurized leach lines, above ground beds, pressurized drip fields, or other approved disposal method. Some systems incorporate supplemental treatment units to further treat the septic tank effluent before discharging to the disposal field. The disposal field relies upon the native soils to receive the wastewater and provide final treatment and filtration.
The County where you reside will typically have an environmental health division of their permitting agency that handles review and permitting of on-site wastewater treatment systems. They will have records of permit for the septic system permitted for your home. These records should show the location and size of your septic tank and the location, size, and depth of your disposal field.
If the County does not have any records for your system you can engage a septic pumping service or septic contractor to locate your septic tank and disposal field. It is a good idea to document the location of the system components to keep from damaging the system components. You can have the pumper or contractor install risers for the access ports to the septic tank to make it easier to locate and maintain.
A septic system will commonly function for thirty years or more. Many factors will influence the longevity of your system. Proper maintenance, including pumping the septic tank every four to six years, will help prolong the system life. The disposal field relies on the native soil conditions for absorption and filtering of the septic tank effluent, so the disposal system needs to be sized properly for the soil conditions. If a disposal field is undersized for the soil conditions the system life span will be shortened. It is also important to be conscious about water use in the household. Excessive water use in the house can overwhelm the system and cause early failure.
Septic systems can malfunction for a variety of reasons. Over time, pipes may deteriorate and collapse, get crushed, become inundated with roots, or clogged with solids and cause backup of the wastewater in the lines back to the house. These conditions can often be corrected by contacting a pumping service or septic contractor to locate the cause of the backup. In many cases the clog or breakage can be cleared or deteriorated piping replaced and the system returned to proper function. If it is determined that the disposal field is no longer able to handle the wastewater load it may be time to get a permit for a new system. If the disposal field begins to show signs of saturation or surfacing of effluent it may be caused by excessive water use, a plumbing leak, or the disposal field may have reached the end of its useful life. If a plumbing leak is found or water use is curbed and the disposal field dries the system may continue to function, but it may be time to consider preparations for a disposal field replacement. Any surfacing of wastewater is a health code violation and corrective action must be taken.
The process for justifying a property for an on-site wastewater treatment system is documented in the policies of the permitting agency in your County. The County is required to meet minimum standards for septic system development mandated by State Law and agreements with their Regional Water Quality Control Board. The specific site and soil conditions on your property will need to be evaluated and documented to the County agency for consideration. The review will identify setback requirements, soil depth and permeability, and possible impacts of shallow ground water. Most Counties require the owner to have a consultant review these conditions and meet with County staff to obtain approval for a disposal system site. The site approval may require percolation testing or ground water testing in order to establish site suitability and appropriate system type and sizing. In some jurisdictions the property owner engages a contractor to excavate test pits and the site review is conducted by County staff.