Most septic systems are conventional systems that use gravity to distribute the effluent from the tank. When site conditions are not appropriate for a conventional system, other types of systems, such as low pressure distribution or mound systems are sometimes used. For more information on these systems see the Virginia Cooperative Extension publications in this series.

Septic systems cannot dispose of all the material that enters the system. Solids that are not broken down by bacteria begin to accumulate in the septic tank and eventually need to be removed. The most common reason for system failure is not having these solids removed on a regular basis. When the holding tank is not pumped out frequently enough, the solids can enter the pipes leading to and from the tank. This can cause sewage to back up into the house or cause the drainage system to fail as the pipes and soil become congested. These problems are often costly to fix, pose a danger to public health, and are a significant source of water pollution. Seepage from inadequate or failing septic systems can contaminate both ground and surface waters. Malfunctioning septic systems are currently the leading cause of groundwater pollution in Virginia.

Wastewater contains several undesirable pollutants. Pathogens such as viruses or bacteria can enter drinking water supplies creating a potential health hazard. Nutrients and organic matter entering waterways can lead to tremendous growth in the quantity of aquatic microorganisms. Metabolic activity of these microbes can reduce oxygen levels in the water causing aquatic life to suffocate.

Maintenance of an Individually Owned Conventional Septic System

The Commonwealth of Virginia advises homeowners to routinely have their septic tanks pumped out every three to five years. However, the frequency with which your tank needs to be pumped may vary depending on the size of the tank and number of people in the household:

Suggested Pumping Frequency (Years)

Tank Size	Household Size (No. of People)
(gal.)	1	2	3	4	5	6	7	8
500	5.8	2.6	1.5	1.0	0.7	0.4	0.3	0.2
750	9.1	4.2	2.6	1.8	1.3	1.0	0.7	0.6
1000	12.4	5.9	3.7	2.6	2.0	1.5	1.2	1.0
1250	15.6	7.5	4.8	3.4	2.6	2.0	1.7	1.4
1500	18.9	9.1	5.9	4.2	3.3	2.6	2.1	1.8
1750	22.1	10.7	6.9	5.0	3.9	3.1	2.6	2.2
2000	25.4	12.4	8.0	5.9	4.5	3.7	3.1	2.6
2250	28.6	14.0	9.1	6.7	5.2	4.2	3.5	3.0
2500	31.9	15.6	10.2	7.5	5.9	4.8	4.0	4.0

Use a Licensed Pumper and Hauler

Use of Additives

Other Ways to Prolong the Life of Your System

Reduce Household Water Use

• Use water-saving shower heads and faucet aerators.
• Install low-flow toilets.
• Repair leaking toilets (place a few drops of food coloring into the toilet tank to detect water leakage into the bowl).
• Make sure sump pumps and roof drains are not connected to the sewage system.
• Use front load washers and space out the time between washings.

Watch What Goes Down the Drain

• Never dispose of toxic or hazardous chemicals by dumping them down the drain as they have the potential to contaminate groundwater.
• Refrain from putting any plastic, cloth, or unnecessary paper products into the sewage system.
• Avoid using garbage disposals as they accelerate the accumulation of solids in the holding tank. Especially avoid putting any grease or oil in the disposal or drain. These can clog pipes and drain field soil and damage your system.

Protect Your Drain Field

• Never park vehicles or place other large objects on the drain field, as this will compact the soil and reduce its ability to treat wastewater. It also may damage the network of drain pipes within the field, causing them to need to be replaced.

• Avoid planting water-loving shrubs with deep root systems or trees near the drain field, as roots could damage the pipes, or they could change moisture levels within the soil causing it to be less effective.

• Effluent from sump pumps and roof drains should not be discharged in the vicinity of the drain field, as this could keep the soil too wet, reducing its capacity to absorb the waste water and causing it to puddle on the surface, creating an environmental and health hazard.

• Check for depressions in the drain field where surface water can collect. The drain field should be level with the surrounding soil to discourage puddling. If the drain field is on a sloping site, surface water diversion may need to be considered.

It is helpful to draw a diagram of the septic system which shows the location of the house, the septic tank and its manholes, and the drain field. This diagram will make it easier for a qualified maintenance worker to check and maintain the system. Sketch a diagram showing the location of your septic tank and drain field in relation to your house. Measure exact distances from at least two referencepoints (such as the corner of the house and a tree) if possible. This need only be a sketch, although the more accurate the drawing, the more helpful it will be in the future, so include measurements of distance wherever possible.

Maintenance Records

Funding for this project was provided, in part, by Extension Service, USDA, under grant number 91-EWQI-1-9034 "Residential Watershed Management" and by the Virginia Department of Conservation and Recreation under grant number 94-0612-10 "Residential Water Quality Management."