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Septic systems allow people in rural areas to dispose of their household sewage in a manner that protects human health and the health of the environment. A system that works properly will deliver wastewater to the soil to be cleaned by natural soil organisms before it is returned to the groundwater table.


The drains of your sinks, showers, toilets, and washing machine all feed into the SEPTIC TANK, which is generally located just a few feet outside of the house. The septic tank has a series of baffles that retain solids and grease but allow clarified water to flow into the LEACHFIELD.

The leachfield is the most important and the most sensitive part of your septic system. It is also the most expensive to repair. The leachfield consists of a perforated pipe set into a gravel-filled trench that is usually about two feet wide and two to ten feet deep. Wastewater is distributed through the trench and is absorbed by the soil. As the water percolates downward through the soil it is filtered and cleansed.

If your leachfield was installed or repaired within the last ten years you may have INSPECTION RISERS at the end of each leaching trench. Inspection risers are three inch diameter pipes that extend from the bottom of the trench to the surface of the ground.

Inspection risers are very useful because, by looking into the riser, you can see the level of the wastewater in your leachfield and how well the leachfield is working. The water level in the riser may rise and fall as water is used in the house, flows through the septic tank into the leachfield, and percolates through the soil. When your leachfield is full (saturated), the level of wastewater in your inspection riser is at or close to ground level and a failure may be occurring.


The best way to take care of your septic tank is to conserve water, pump the tank regularly to remove grease and solids, monitor the inspection risers if you have them, and don't put extra solids or harmful materials (such as paints, solvents, or grease) into the system.


The accumulated solids in the bottom of the septic tank should be pumped out every three to seven years to prolong the life of your system. Septic systems must be maintained regularly to stay working.

Neglect or abuse of your septic system can cause it to fail. Failing septic systems can:

  • cause a serious health threat to your family and neighbors
  • be very expensive to repair
  • degrade the environment, especially lakes, streams and watershed
  • put thousands of water groundwater supply users at risk if you live in a public water supply
  • reduce the value of your property


  • sewage surfacing over the drainfield
  • lush, green growth over the drainfield (especially after storms)
  • sewage back-ups in the house
  • slow draining toilets or drains
  • sewage odors


  • DO have your tank pumped out and system inspected every 3 to 7 years by a licensed septic contractor (listed in the yellow pages )
  • DO keep a record of pumping, inspections, and other maintenance
  • DO practice water conservation. Repair dripping faucets and leaking toilets, run washing machines and dishwashers throughout the week rather than doing it all in one day, avoid long showers, discontinue use of garbage disposals, put kitchen wastes in the garbage instead of down the sink, use water-saving features in faucets, shower heads and toilets
  • DO learn the location of your septic system and drainfield. Keep a sketch of if handy for service visits. If your system has a flow diversion valve, learn its location, and turn it once a year. Flow diverters can add many years to the life of your system.
  • DO divert drains and surface water from driveways and hillsides away from the septic system. Keep sump pumps and house footing drains away from the septic system as well.
  • DO take leftover hazardous household chemicals to your approved hazardous waste collection center for disposal. Use bleach, disinfectants, and drain and toilet bowl cleaners sparingly and in accordance with product labels.
  • DO monitor leachfield inspection risers before and after a heavy rain
  • DON'T allow anyone to drive or park over any part of the system. The area over the drainfield should be left undisturbed with only a mowed grass cover. Roots from nearby trees or shrubs may clog and damage your drain lines
  • DON'T make or allow repairs to your septic system without obtaining the required health department permit and advice. Use professional licensed septic contractors when needed.
  • DON'T use commercial septic tank additives. These products usually do not help and some may hurt your system in the long run.
  • DON'T use your toilet as a trash can by dumping nondegradables down your toilet drains. Also don't poison your septic system and the groundwater by pouring harmful chemicals down the drain. They can kill the beneficial bacteria that treat your wastewater. Keep the following materials out of your septic system:

grease, disposal diapers,
plastics, etc.

gasoline, oil, point thinner,
pesticides, antifreeze, etc.


On the inside of your house, you may notice drains or the toilet operating sluggishly or backing up. You may notice gurgling noises coming from the plumbing vents. On the outside of the house you may find a damp spot on the ground or puddling or ponding of water, and/or a distinct septic smell. Lush plant growth in a leachfield area that is not irrigated may also be a sign of a problem. If you have inspection risers, the water level may be at or near the ground surface.

When groundwater levels rise after a period of heavy rains, or if you have heavy clay soils, the leachfield may become saturated and cause wastewater to backup into the septic tank (causing sluggish or noisy drains) or rise to the surface of the ground (creating a damp spot or puddle). Some of these symptoms may occur intermittently, usually after a heavy rain, and close attention to water use and inspection risers is needed in order to identify a problem.

If the level stays high for more than a few days, the leachfield may be saturated and on the verge of failing. Pump the tank to prevent surfacing effluent and talk with a septic pumper or contractor to determine if the leachfield should be repaired.


Have the septic tank inspected and pumped by a septic tank pumping service. If the outlet from the septic tank to the leachfield is covered by effluent, or if effluent flows from the leachfield back into the tank when the tank is pumped, the leachfield is either blocked or saturated. A saturated leachfield will need to be abandoned and replaced (repaired) by a new leachfield in a different location on your property.

To reduce loading on the system until it can be repaired, be sure there are no leaky fixtures in the house and keep all water use to an absolute minimum. Check all toilets with dye for leaks and turn them off immediately if one is found. Discontinue use of the washing machine (unless you have a separate greywater sump) and keep showers brief.

If there is a puddle of sewage on the ground, it is a health hazard and children and pets should be kept away from the area. Have the tank pumped as necessary to prevent surfacing effluent.

If you system appears to be functioning properly but you suspect that the leachfield's ability to absorb wastewater may be hampered by either clay soils or high groundwater, a GREYWATER SUMP may be installed to reduce loading on the septic system.


A greywater sump is sometimes used in conjunction with a standard septic system to help extend the life of the leachfield. A sump may be useful in households that wash five or more loads of laundry per week.

A greywater sump is a simple leaching pit that receives wastewater from the washing machine, shower, and/or bathroom sink. Toilet wastes MUST be disposed of in a septic tank and wastes from the kitchen sink have too many solids and grease to be processed effectively by a sump.

Greywater sumps must be at least 120 cubic feet in volume (the size will vary depending on the amount of wastewater it will be receiving), filled with drain rock, and covered with roofing paper and a layer of soil. A brochure describing greywater sumps and the necessary steps to obtaining a permit can be obtained from the County Department of Environmental Health. A permit is required to ensure that the sump is properly located and installed.


If you think your system needs a repair, contact our office (454-2022) between 8:00 and 9:30 a.m. and speak to your district Environmental Health Specialist. The district specialist will discuss repair standards such as setbacks, leachfield size, and other information that may aid you in evaluating and selecting contractor bids. The specialist will also tell you how to get started on the permit process. A permit is needed for ANY septic system repair except for minor plumbing.

Our office has a list of licensed septic contractors, most of which can also be found in the yellow pages of the phone book. It is a good idea to have your septic permit approved prior to getting bids so they are based on an approved design. Otherwise, changes in the design during the permit process may alter the bid. It is important that the repair be done properly in order to protect public health and give you good long-term service.


A system that is properly designed and maintained will contribute clear water, nitrate, and very small amounts of salts to the groundwater supply. Nitrate migrates with groundwater to nearby streams and the river and may encourage algae to grow, which can be both good and bad. Small invertebrates that are the main food source for fish and other wildlife need algae for food and habitat but too much algae may be unsightly and adversely affect swimming areas. Decomposing algae may also impart a moldy taste to the water. When the water is used to supply drinking water needs, as is the case with the San Lorenzo River, it must be treated to reduce odor before distribution.

Nitrate in very high concentrations is also toxic to humans and can render a water source unfit for human use. Current septic system repair and new system standards are designed to ensure that nitrate in groundwater and surface water never reach dangerous levels.

A failing septic system will allow large amounts of viruses and bacteria to contaminate the surface of the ground and any nearby surface waters. People and animals contacting the contaminated area are susceptible to infection from the viruses and bacteria. Children, the elderly, and people with depressed immune systems are much more likely to experience problems than healthy adults.

Allowing greywater to flow onto the surface of the ground is also hazardous even if biodegradable soaps are used. Viruses and bacteria are present and the pH and absorptive capacity of the soil can be damaged. In dry years the problems can become worse because of the lack of flushing action from rains.

All wastewater, including greywater, must be disposed of under the surface of the ground in a approved disposal system. Discharging wastewater to the surface of the ground, or to surface waters, creates a public health hazard and is a violation of the California Health and Safety Code.

Greywater irrigation (particularly above ground irrigation) is a risky way to conserve water. For example, if a small adult were to press the palm of her hand into grass that had been irrigated with greywater, she would pick up roughly 30 viruses on her hand and have a 30% chance of being infected. Children, the elderly, and people with depressed immune systems are even more likely to experience health problems from contact with greywater.


There are approximately 22,000 septic systems in the rural areas of Santa Cruz County. Successful use of these systems requires that they be properly maintained to protect public health and prevent water pollution. In order to promote better septic system management and maintenance in these areas, County Service Area 12 (CSA 12) was established in 1989 by the County Board of Supervisors. A small fee is collected with each property tax bill in CSA 12.

The funds raised from CSA 12 are used to pay for permanent facilities for the disposal of septic tank sludge at the City of Santa Cruz Sewage Treatment Plant. Regular pumping of accumulated solids in septic tanks is a very important part of maintenance and is dependent upon a suitable location for disposal.

The funds are also used for monitoring water quality impacts of septic systems, public education about septic system maintenance and maintaining a computerized record keeping system of pumping, inspections, and repairs.

The San Lorenzo River watershed area has an even greater need for proper septic system management than the rest of the county. The area has a very high density of septic systems and any pollution from septic failures will impact the San Lorenzo River, which is used for water supply and recreation. Because of these conditions, the State has directed that the County and residents closely manage septic systems in the Watershed.

The County has implemented a comprehensive wastewater management program for the San Lorenzo Watershed to address these concerns. This program provides for regular water quality testing, inspection and evaluation of all septic systems approximately once every six years, and special public education efforts. The program is funded through a special zone, CSA 12A. An additional service charge is billed to developed parcels in this zone. The inspection and public education programs will result in a general upgrading of septic systems in many areas of the San Lorenzo Valley, as well as enhanced management by homeowners.

For more information contact the Environmental Health Service at 454-2022.