Home Owners Guide to Septic Systems
Your Septic System is your responsibility! How does it work?
Top Four Things You Can Do to Protect Your Septic System
1. Regularly inspect your system and pump your tank as necessary.
2. Use water efficiently.
3. Don’t dispose of household hazardous wastes in sinks or toilets.
4. Care for your drainfield.
Typical septic system:
All of your household wastewater exits your home through a pipe to the septic tank.
The septic tank is a buried, watertight container typically made of concrete, fiberglass, or polyethylene. It holds the wastewater long enough to allow solids to settle out (forming
sludge) and oil and grease to float to the surface (as scum). It also allows partial decomposition of the solid materials. Compartments and a T-shaped outlet in the septic tank prevent the sludge and scum from leaving the tank and traveling into the drainfield area. Screens are also recommended to keep solids from entering the drainfield. Newer tanks generally have risers with lids at the ground surface to allow easy location, inspection, and pumping of the tank.
Septic system aliases:
• On-lot system
• Onsite system
• Individual sewage disposal system
• Onsite sewage disposal system
• Onsite wastewater treatment system
To prevent buildup, sludge and floating scum need to be removed through periodic pumping of the septic tank. Regular inspections and pumping are the best and cheapest way to keep your septic
system in good working order.
Typical single-compartment septic tank with ground-level inspection risers and screen
The wastewater exits the septic tank and is discharged into the drainfield for further treatment by the soil. The partially treated wastewater is pushed along into the drainfield for further treatment every time new wastewater enters the tank. If the drainfield is overloaded with too much liquid, it will flood, causing sewage to flow to the ground surface or create backups in plumbing fixtures
and prevent treatment of all wastewater. A reserve drainfield, required by many states, is an area on your property suitable for a new drainfield system if your current drainfield fails. Treat
this area with the same care as your septic system.
Septic tank wastewater flows to the drainfield, where it percolates into the
soil, which provides final treatment by removing harmful bacteria, viruses,
and nutrients. Suitable soil is necessary for successful wastewater treatment.
Because many areas don’t have soils suitable for typical septic systems, you might have or need an alternative system. You might also have or need an alternative system if there are too many typical septic systems in one area or the systems are too close to groundwater or surface waters.
Finding Your System
Your septic tank, drainfield, and reserve drainfield should be clearly designated on the “as-built” drawing for your home. (An “as-built” drawing is a line drawing that accurately portrays the buildings on your property and is usually filed in your local land records.) You might also see lids or
manhole covers for your septic tank. Older tanks are often hard to find because there
are no visible parts. An inspector/pumper can help you locate your septic system if
your septic tank has no risers.
Some Septic Systems use new technology to improve treatment processes and might need
special care and maintenance. Some alternative systems use sand, peat, or plastic media instead of soil to promote wastewater treatment. Other systems might use wetlands, lagoons, aerators, or disinfection devices. Float switches, pumps, and other electrical or mechanical components are often used in alternative systems. Alternative systems should be inspected annually. Check with your local health department or installer for more information on operation and maintenance needs if you have or need an alternative system.
When septic systems are properly designed, constructed, and maintained, they effectively reduce or eliminate most human health or environmental threats posed by pollutants in household wastewater. However, they require regular maintenance or they can fail. Septic systems need to be monitored to
ensure that they work properly throughout their service lives.
A key reason to maintain your septic system is to save money! Failing septic systems are expensive to repair or replace, and poor maintenance is often the culprit. Having your septic system inspected regularly is a bargain when you consider the cost of replacing the entire system. Your system will need
pumping depending on how many people live in the house and the size of the system. An unusable septic system or one in disrepair will lower your property value and could pose a legal liability.
Protecting health and the environment
Other good reasons for safe treatment of sewage include preventing the spread of infection and disease and protecting water resources. Typical pollutants in household wastewater are nitrogen, phosphorus, and disease causing bacteria and viruses. If a septic system is working properly, it will
effectively remove most of these pollutants.
Why should I maintain my septic system?
With one-fourth of U.S. homes using septic systems, more than 4 billion gallons of wastewater per day is dispersed below the ground’s surface.
Inadequately treated sewage from septic systems can be a cause of groundwater contamination. It poses a significant threat to drinking water and human health because it can contaminate drinking water wells and cause diseases and infections in people and animals. Improperly treated sewage
that contaminates nearby surface waters also increases the chance of swimmers contracting a variety of infectious diseases. These range from eye and ear infections to acute gastrointestinal illness and diseases like hepatitis.
Inspect and pump frequently
You should have a typical septic system inspected at least every 3 years by a professional and your tank pumped as recommended by the inspector (generally every 3 to 5 years). Alternative systems with electrical float switches, pumps, or mechanical components need to be inspected
more often, generally once a year. Your service provider should inspect for leaks and look at the scum and sludge layers in your septic tank. If the bottom of the scum layer is within 6 inches of the bottom of the outlet tee or the top of the sludge layer is within 12 inches of the outlet tee, your tank needs to be pumped. Remember to note the sludge and scum levels determined by your service provider in
your operation and maintenance records. This information will help you decide how often pumping is necessary.
How do I maintain my septic system?
What Does an Inspection Include?
• Locating the system.
• Uncovering access holes.
• Flushing the toilets.
• Checking for signs of back up.
• Measuring scum and sludge layers.
• Identifying any leaks.
• Inspecting mechanical components.
• Pumping the tank if necessary.
Four major factors influence the frequency of pumping:
The number of people in your household, the amount of wastewater generated (based on the number of people in the household and the amount of water used), the volume of solids in the wastewater (for example, using a garbage disposal increases the amount of solids), and septic tank size.
Some makers of septic tank additives claim that their products break down the sludge in septic tanks so the tanks never need to be pumped. Not everyone agrees on the effectiveness of additives. In fact, septic tanks already contain the microbes they need for effective treatment. Periodic
pumping is a much better way to ensure that septic systems work properly and provide many years of service. Regardless, every septic tank requires periodic pumping.
In the service report, the pumper should note any repairs completed and whether the tank is in good condition. If the pumper recommends additional repairs he or she can’t perform, hire someone to make the repairs as soon as possible.
Use water efficiently
Average indoor water use in the typical single-family home is almost 70 gallons per person per day. Leaky toilets can waste as much as 200 gallons each day. The more water a household conserves, the less water enters the septic system. Efficient water use can improve the operation of
the septic system and reduce the risk of failure.
Toilet use accounts for 25 to 30 percent of household water use. Do you know how many gallons of water your toilet uses to empty the bowl? Most older homes have toilets with 3.5- to 5-gallon reservoirs, while newer high-efficiency toilets use 1.6 gallons of water or less per flush. If you have
problems with your septic system being flooded with household water, consider reducing the volume of water in the toilet tank if you don’t have a high-efficiency model or replacing your existing toilets with high-efficiency models.
Faucet aerators and high efficiency shower heads Faucet aerators help reduce water use
and the volume of water entering your septic system. High-efficiency showerheads
or shower flow restrictors also reduce water use. Water fixtures Check to make sure your toilet’s reservoir isn’t leaking into the bowl. Add five drops of liquid food coloring to the reservoir before bed. If the dye is in the bowl the next morning, the reservoir is leaking and repairs are needed.
A small drip from a faucet adds many gallons of unnecessary water to your system every day. To see how much a leak adds to your water usage, place a cup under the drip for 10 minutes. Multiply the amount of water in the cup by 144 (the number of minutes in 24 hours, divided by 10). This is the
total amount of clean water traveling to your septic system each day from that little leak.
Use Water Efficiently!
• Install high-efficiency shower heads
• Fill the bathtub with only as much water as you need
• Turn off faucets while shaving or brushing your teeth
• Run the dishwasher and clothes washer only when they’re full
• Use toilets to flush sanitary waste only (not kitty litter, diapers, or other trash)
• Make sure all faucets are completely turned off when not in use
• Maintain your plumbing to eliminate leaks
• Install aerators in the faucets in your kitchen and bathroom
• Replace old dishwashers, toilets, and clothes washers with new, high efficiency models.
For more information on water conservation, please visit www.epa.gov/owm/water-efficiency/index.htm
Watch your drains
What goes down the drain can have a major impact on how well your septic system works.
What shouldn’t you flush down your toilet? Dental floss, feminine hygiene products, condoms, diapers, cotton swabs, cigarette butts, coffee grounds, cat litter, paper towels, and other kitchen and athroom items that can clog and potentially damage septic system components if they become trapped. Flushing household chemicals, gasoline, oil, pesticides, antifreeze, and paint can stress or destroy the biological treatment taking place in the system or might contaminate surface waters and groundwater. If your septic tank pumper is concerned about quickly accumulating scum layers, reduce the flow of floatable materials like fats, oils, and grease into your tank or be prepared to pay for more frequent inspections and pumping.
By selecting the proper load size, you’ll reduce water waste. Washing small loads
of laundry on the large-load cycle wastes precious water and energy. If you can’t
select load size, run only full loads of laundry. Doing all the household laundry in one day
might seem like a time-saver, but it could be harmful to your septic system. Doing load after load does not allow your septic tank time to adequately treat wastes. You could be flooding your
drainfield without allowing sufficient recovery time. Try to spread water usage throughout the week. A new Energy Star clothes washer uses 35 percent less energy and 50 percent less water than a standard model.
Care for your drainfield
Your drainfield is an important part of your septic system. Here are a few things you should do to maintain it:
• Plant only grass over and near your septic system. Roots from nearby trees or shrubs might clog and damage the drainfield.
• Don’t drive or park vehicles on any part of your septic system. Doing so can compact the soil in your drainfield or damage the pipes, tank, or other septic system components.
• Keep roof drains, basement sump pump drains, and other rainwater or surface water drainage systems away from the drainfield. Flooding the drainfield with excessive water slows down or stops treatment processes and can cause plumbing fixtures to back up. If the amount of wastewater entering the system is more than the system can handle, the wastewater backs up into the house or yard and creates a health hazard.
You can suspect a system failure not only when a foul odor is emitted but also when partially treated wastewater flows up to the ground surface. By the time you can smell or see a problem, however, the damage might already be done. By limiting your water use, you can reduce the amount of wastewater your system must treat. When you have your system inspected and pumped as needed, you reduce the chance of system failure. A system installed in unsuitable soils can also fail. Other failure risks
include tanks that are inaccessible for maintenance, drainfields that are paved or parked on, and tree roots or defective components that interfere with the treatment process.
What can make my system fail?
The most obvious septic system failures are easy to spot. Check for pooling water or muddy soil around your septic system or in your basement. Notice whether your toilet or sink backs up when you flush or do laundry. You might also notice strips of bright green grass over the drainfield. Septic
systems also fail when partially treated wastewater comes into contact with groundwater. This type of failure is not easy to detect, but it can result in the pollution of wells, nearby streams, or other
bodies of water. Check with a septic system professional and the local health department if you suspect such a failure.
Does someone in your house use the utility sink to clean out paint rollers or flush toxic cleaners? Oil-based paints, solvents, and large volumes of toxic cleaners should not enter your septic system. Even latex paint cleanup waste should be minimized. Squeeze all excess paint and stain from
brushes and rollers on several layers of newspaper before rinsing. Leftover paints and wood stains should be taken to your local household hazardous waste collection center. Remember that your septic system contains a living collection of organisms that digest and treat waste.
Household cleaners For the most part, your septic system’s bacteria should recover quickly
after small amounts of household cleaning products have entered the system. Of course, some cleaning products are less toxic to your system than others. Labels can help key you into the potential
toxicity of various products. The word “Danger” or “Poison” on a label indicates that the product is highly hazardous. “Warning” tells you the product is moderately hazardous. “Caution” means the
product is slightly hazardous. (“Nontoxic” and “Septic Safe” Stop, look, and smell! are terms created by advertisers to sell products.) Regardless of the type of product, use it only in the amounts shown on the label instructions and minimize the amount discharged into your septic system.
Hot tubs are a great way to relax. Unfortunately, your septic system was not designed to handle large quantities of water from your hot tub. Emptying hot tub water into your septic system stirs the solids in the tank and pushes them out into the drainfield, causing it to clog and fail. Draining your hot tub
into a septic system or over the drainfield can overload the system. Instead, drain cooled hot tub water onto turf or landscaped areas well away from the septic tank and drainfield, and in accordance with local regulations. Use the same caution when draining your swimming pool.
Water Purification Systems
Some freshwater purification systems, including water softeners, unnecessarily pump water into the septic system. This can contribute hundreds of gallons of water to the septic tank, causing agitation of solids and excess flow to the drainfield. Check with your licensed plumbing professional
about alternative routing for such freshwater treatment systems.
Eliminating the use of a garbage disposal can reduce the amount of grease and solids entering the septic tank and possibly clogging the drainfield. A garbage disposal grinds up kitchen scraps, suspends
them in water, and sends the mixture to the septic tank. Once in the septic tank, some of the materials are broken down by bacterial action, but most of the grindings have to be pumped out of
the tank. Using a garbage disposal frequently can significantly increase the accumulation of sludge and scum in your septic tank, resulting in the need for more frequent pumping.
Improper design or installation
Some soils provide excellent wastewater treatment; others don’t. For this reason, the design of the drainfield of a septic system is based on the results of soil analysis. Homeowners and system designers sometimes underestimate the significance of good soils or believe soils can handle any volume of wastewater applied to them. Many failures can be attributed to having an undersized drainfield or high seasonal groundwater table. Undersized septic tanks—another design failure—allow solids to clog the drainfield and result in system failure.
If a septic tank isn’t watertight, water can leak into and out of the system. Usually, water from the environment leaking into the system causes hydraulic overloading, taxing the system beyond its capabilities and causing inadequate treatment and sometimes sewage to flow up to the ground surface. Water leaking out of the septic tank is a significant health hazard because the leaking
wastewater has not yet been treated. Even when systems are properly designed, failures due to poor installation practices can occur. If the drainfield is not properly leveled, wastewater can
overload the system. Heavy equipment can damage the drainfield during installation which can lead to soil compaction and reduce the wastewater infiltration rate. And if surface drainage isn’t diverted away from the field, it can flow into and saturate the drainfield.
Local Health Department
EPA Onsite/Decentralized Management Homepage www.epa.gov/owm/septic
EPA developed this Web site to provide tools for communities investigating and implementing onsite/decentralized management programs. The Web site contains fact sheets, program summaries, case studies, links to design and other manuals, and a list of state health department contacts that can put you in touch with your local health department.
National Small Flows Clearinghouse www.nesc.wvu.edu Funded by grants from EPA, the NSFC helps America’s small communities and individuals solve their wastewater problems. Its activities include
a Web site, online discussion groups, a toll-free assistance line (800- 624-8301), informative publications, and a free quarterly newsletter and magazine.
Rural Community Assistance Program
www.rcap.org RCAP is a resource for community leaders and others looking for technical assistance services and training related to rural drinking water supply and wastewater treatment needs, rural solid waste programs, housing, economic development, comprehensive community assessment and planning, and environmental regulations.
National Onsite Wastewater Recycling Association, Inc.
www.nowra.org NOWRA is a national professional organization to advance and promote the onsite wastewater industry. The association promotes the need for regular service and educates the public on the need for properly designed and maintained septic systems. For more information 14 A Homeowner’s Guide to Septic Systems Septic Yellow Pages www.septicyellowpages.com
The Septic Yellow Pages provides listings by state for professional septic pumpers, installers, inspectors, and tank manufacturers throughout the United States. This Web site is designed to answer simple septic system questions and put homeowners in contact with local septic system
professionals. National Association of Wastewater Transporters www.nawt.org NAWT offers a forum for the wastewater industry to exchange ideas and concerns. The NAWT Web site lists state associations and local inspectors and pumpers. EPA-832-B-02-005 December 2002 Revised March 2005
Additional copies can be obtained from: U.S. EPA Publications Clearinghouse
P.O. Box 42419
Cincinnati, OH 45241
Office of Water U.S. Environmental Protection Agency
This document has been reviewed in accordance with U.S. Environmental Protection Agency policy and approved for publication. Mention of profit-making organizations, trade names, or commercial products does not constitute endorsement or recommendation for use. Recycled/Recyclable Printed with vegetable-based ink on paper that contains a minimum of 50% post-consumer fiber content rocessed chlorine-free.
Septic System Dos and Don’ts (adapted from National Small Flows Clearinghouse)
• Check with the local regulatory agency or inspector/pumper if you have a garbage disposal unit
to make sure that your septic system can handle this additional waste.
• Check with your local health department before using additives. Commercial septic tank additives do not eliminate the need for periodic pumping and can be harmful to the system.
• Use water efficiently to avoid overloading the septic system. Be sure to repair leaky faucets or
toilets. Use high-efficiency fixtures.
• Use commercial bathroom cleaners and laundry detergents in moderation. Many people prefer
to clean their toilets, sinks, showers, and tubs with a mild detergent or baking soda.
• Check with your local regulatory agency or inspector/pumper before allowing water softener
backwash to enter your septic tank.
• Keep records of repairs, pumpings, inspections, permits issued, and other system maintenance
• Learn the location of your septic system. Keep a sketch of it with your maintenance record for
• Have your septic system inspected and pumped as necessary by a licensed inspector/contractor.
• Plant only grass over and near your septic system. Roots from nearby trees or shrubs might
clog and damage the drainfield.
• Your septic system is not a trash can. Don’t put dental floss, feminine hygiene products,
condoms, diapers, cotton swabs, cigarette butts, coffee grounds, cat litter, paper towels, latex
paint, pesticides, or other hazardous chemicals into your system.
• Don’t use caustic drain openers for a clogged drain. Instead, use boiling water or a drain snake
to open clogs.
• Don’t drive or park vehicles on any part of your septic system. Doing so can compact the soil
in your drainfield or damage the pipes, tank, or other septic system components.