Septic

A

Systems

to

Guide

Homeowner’s
What’s Inside

Your septic system is your responsibilty . . . . . 1

How does it work? . . . . . . . . . . . . . . 1

Why should I maintain my septic system? . . . . 4

How do I maintain my septic system? . . . . . . 5

What can make my system fail? . . . . . . . . . 9

For more information . . . . . . . . . . . . . 13
A Homeowner’s Guide to Septic Systems 1

Did you know that as a homeowner you’re responsible 

for maintaining your septic system? Did you know that 

maintaining your septic system protects your investment 

in your home? Did you know that you should periodically 

inspect your system and pump out your septic tank?

If properly designed, constructed and maintained, your 

septic system can provide long-term, effective treatment of 

household wastewater. If your septic system isn’t maintained, 

you might need to replace it, costing you thousands of dollars. A malfunctioning system can contaminate groundwater 

that might be a source of drinking water. And if you sell your 

home, your septic system must be in good working order.

This guide will help you care for your septic system. It will help you understand how your system works and what steps you can take as a homeowner 

to ensure your system will work properly. To help you learn more, consult 

the resources listed at the back of this booklet. A helpful checklist is also 

included at the end of the booklet to help you keep track of your septic 

system maintenance. 

Components

A typical septic system has four main components: 

a pipe from the home, a septic tank, a drainfi eld, 

and the soil. Microbes in the soil digest or remove 

most contaminants from wastewater before it eventually reaches groundwater. 

Your Septic System is your responsibility!

Howdoes it work?

1. Inspect your system 

(every 3 years) and pump 

your tank as necessary 

(generally every 3 to 5 

years).

2. Use water efficiently.

3. Don’t dispose of 

household hazardous 

wastes in sinks or toilets.

4. Care for your drainfield.

Top Four Things You Can Do 

to Protect Your Septic System

Typical onsite wastewater treatment system
2 A Homeowner’s Guide to Septic Systems

Pipe from the home

All of your household wastewater exits your home 

through a pipe to the septic tank. 

Septic tank

The septic tank is a buried, watertight container typically 

made of concrete, fi berglass, or polyethylene. It holds the 

wastewater long enough to allow solids to settle out (forming sludge) and oil and grease to fl oat 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 drainfi eld area. Screens are also recommended to keep solids from 

entering the drainfi eld.

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

Tip To prevent buildup, sludge and floating scum need to be removed 

through periodic pumping of the septic tank. Regular inspections and 

pumping as necessary (generally every 3 to 5 years) 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
A Homeowner’s Guide to Septic Systems 3

Drainfi eld

The wastewater exits the septic tank and is discharged into the drainfi eld 

for further treatment by the soil. The partially treated wastewater is pushed 

along into the drainfi eld for further treatment every time new wastewater 

enters the tank. 

If the drainfi eld is overloaded with too much liquid, it will fl ood, causing 

sewage to fl ow to the ground surface or create backups in plumbing fi xtures 

and prevent treatment of all wastewater.

A reserve drainfi eld, required by many states, is an area on your property 

suitable for a new drainfi eld system if your current drainfi eld fails. Treat 

this area with the same care as your septic system. 

Soil

Septic tank wastewater fl ows to the drainfi eld, where it percolates into the 

soil, which provides fi nal treatment by removing harmful bacteria, viruses, 

and nutrients. Suitable soil is necessary for successful wastewater treatment. 

Alternative systems

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. Alternative septic 

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. 
4 A Homeowner’s Guide to Septic Systems

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. 

Saving money

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 (at least every 

3 years) is a bargain when you consider the cost of replacing the entire 

system. Your system will need pumping (generally every 3 to 5 years), 

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 diseaseWhyshould I maintain my septic system?
A Homeowner’s Guide to Septic Systems 5

causing bacteria and viruses. If a septic system is working properly, it will 

effectively remove most of these pollutants. 

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 signifi cant 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 your 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). Systems with electrical fl oat switches, pumps, 

or mechanical components need to be inspected more 

often. 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. (See the checklist 

included at the end of the booklet.)

Howdo I maintain my septic system?

What Does an 

Inspection Include?

• Locating the system.

• Uncovering access holes.

• Flushing the toilets.

• Checking for signs of 

backup.

• Measuring scum and 

sludge layers.

• Identifying any leaks.

•Inspecting mechanical 

components.

• Pumping the tank if 

necessary.
6 A Homeowner’s Guide to Septic Systems

Four major factors infl uence 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. Effi cient water use can improve the operation of 

the septic system and reduce the risk of failure.

High-effi ciency toilets

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-effi ciency toilets use 1.6 gallons of water or less per fl ush. If you have 

problems with your septic system being fl ooded with household water, 

consider reducing the volume of water in the toilet tank if you don’t have 

a high-effi ciency model. Plastic containers (such as 1⁄2-gallon plastic milk 

jugs) can be fi lled with small rocks and placed in a toilet tank to reduce the 
A Homeowner’s Guide to Septic Systems 7

amount of water used per fl ush. (Be 

sure that the plastic containers do not 

interfere with the fl ushing mechanisms 

or the fl ow of water.) You’ll save about 

1⁄2 gallon of water per fl ush! You might 

also consider replacing your existing 

toilet with a high-effi ciency model to 

achieve even more water savings.

Faucet aerators and higheffi ciency showerheads

Faucet aerators help reduce water use 

and the volume of water entering your 

septic system. High-effi ciency showerheads or shower fl ow restrictors also 

reduce water use.

Water fi xtures

Check to make sure your toilet’s 

reservoir isn’t leaking into the bowl. 

Add fi ve 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 showerheads

• 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
8 A Homeowner’s Guide to Septic Systems

Watch your drains

What goes down the drain can have a major impact on how well your 

septic system works.

Waste disposal

What shouldn’t you fl ush down your toilet? Dental fl oss, feminine hygiene 

products, condoms, diapers, cotton swabs, cigarette butts, coffee grounds, 

cat litter, paper towels, and other kitchen and bathroom 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 

fl ow of fl oatable materials like fats, oils, and grease into your tank or be 

prepared to pay for more frequent inspections and pumping.

Washing machines

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 fl ooding 

your drainfi eld without allowing suffi cient 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.
A Homeowner’s Guide to Septic Systems 9

Care for your drainfield

Your drainfi eld 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 drainfi eld.

• Don’t drive or park vehicles on any part of your septic system. Doing 

so can compact the soil in your drainfi eld 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 drainfi eld. Flooding the 

drainfi eld with excessive water slows down or stops treatment processes 

and can cause plumbing fi xtures 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 fl ows 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, drainfi elds that are 

paved or parked on, and tree roots or defective components that interfere 

with the treatment process. 

What can make my system fail?
10 A Homeowner’s Guide to Septic Systems

Failure symptoms

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 fl ush or do laundry. You 

might also notice strips of bright green grass over the drainfi eld. 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, and remember to have your septic 

system inspected by a professional at 

least every 3 years.

Failure causes

Household toxics

Does someone in your house use the utility sink to clean out paint rollers 

or fl ush 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!
A Homeowner’s Guide to Septic Systems 11

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

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 

drainfi eld, causing it to clog and fail. Draining your hot tub 

into a septic system or over the drainfi eld can overload the system. Instead, 

drain cooled hot tub water onto turf or landscaped areas well away from 

the septic tank and drainfi eld, and in accordance with local regulations. 

Use the same caution when draining your swimming pool.

Water Purifi cation Systems

Some freshwater purifi cation 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 

fl ow to the drainfi eld. Check with your licensed plumbing professional 

about alternative routing for such freshwater treatment systems.

Garbage disposals

Eliminating the use of a garbage disposal can reduce the amount of 

grease and solids entering the septic tank and possibly clogging the 

drainfi eld. 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 signifi cantly 

increase the accumulation of sludge and scum in your septic tank, 

resulting in the need for more frequent pumping. 
12 A Homeowner’s Guide to Septic Systems

Improper design or installation

Some soils provide excellent wastewater treatment; others don’t. For this 

reason, the design of the drainfi eld of a septic system is based on the results 

of soil analysis. Homeowners and system designers sometimes underestimate the signifi cance of good soils or believe soils can handle any volume 

of wastewater applied to them. Many failures can be attributed to having 

an undersized drainfi eld or high seasonal groundwater table. Undersized 

septic tanks—another design failure—allow solids to clog the drainfi eld 

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 fl ow up to the ground surface. Water 

leaking out of the septic tank is a signifi cant 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 drainfi eld is not properly leveled, wastewater can 

overload the system. Heavy equipment can damage the drainfi eld during 

installation which can lead to soil compaction and reduce the wastewater 

infi ltration rate. And if surface drainage isn’t diverted away from the fi eld, 

it can fl ow into and saturate the drainfi eld.
A Homeowner’s Guide to Septic Systems 13

Local Health Department

EPA Onsite/Decentralized Management Homepage

www.epa.gov/owm/onsite

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. 

For more information
14 A Homeowner’s Guide to Septic Systems

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.

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

Additional copies can be obtained from:

U.S. EPA Publications Clearinghouse

P.O. Box 42419

Cincinnati, OH 45241

Telephone: 800-490-9198 • Fax: 513-489-8695

Offi ce of Water

U.S. Environmental Protection Agency

Notice

This document has been reviewed in accordance with U.S. Environmental Protection Agency policy 

and approved for publication. Mention of profi t-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 fi ber 

content processed chlorine-free.
A Homeowner’s Guide to Septic Systems 15

Septic System Dos and Don’ts

(adapted from National Small Flows Clearinghouse)

Dos

• 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 effi ciently to avoid overloading the septic system. Be sure to repair leaky faucets or 

toilets. Use high-effi ciency fi xtures.

• 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 

activities.

• Learn the location of your septic system. Keep a sketch of it with your maintenance record for 

service visits.

• Have your septic system inspected at least every 3 years and pumped periodically (generally 

every 3 to 5 years) 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 drainfi eld.

Don’ts

• Your septic system is not a trash can. Don’t put dental fl oss, 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 drainfi eld or damage the pipes, tank, or other septic system components.

EPA-832-B-02-005

December 2002