How a Septic System works

Your Septic System is your responsibility!


Howdoes it work?

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.

Top Four Things You Can Do
to Protect Your Septic System

Typical septic 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, 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

Tip 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

A Homeowner’s Guide to Septic Systems 3

Drainfield

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.

Soil

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.

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 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-