How Your Septic System
Works
A septic system has two
major components: a septic tank and a drainfield.
Septic
Tank: Waste water
flows from the house to the septic tank. The tank is
designed to retain waste water and allow heavy solids to
settle to the bottom. These solids are partially
decomposed by bacteria to form sludge. Grease and light
particles float, forming a layer of scum on top of the
waste water. Baffles installed at the inlet and outlet
of the tank to help prevent scum and solids from
escaping. [See Figure 1.] Newer septic tanks can have a
partial concrete dividing wall in the center, thus
making two compartments. This helps ensure the sludge
does not get forced out of the baffle into the
drainfield. Newer tanks can also have two manhole
covers, one above each baffle.
Possible Signs of
Trouble
The
septic tank has not been pumped out in the past five
years. Even if the system appears to be working well,
sludge may have built up to the point where waste water
is released without sufficient time in the tank for
treatment and settling of particles. This situation may
result in pollution of groundwater or cause eventual
clogging of the drainfield.
A wet area or standing
water occurs above the drainfield. This situation can
develop when sludge particles clog the drainfield, when
tree roots or broken pipes keep the waste water from
dispersing through the entire drainfield, or when water
use in the house regularly exceeds the design capacity
of the system. When these conditions occur, waste water
does not move through the soil as it should, and instead
rises to the surface creating a serious health risk and
odor problems.
Toilets run slowly or
backup: in the worst cases, the basement is flooded with
sewage. This can be the result of plugged sewer lines to
the tank, a plugged inlet or outlet pipe, a full septic
tank, or a failed drainfield.
Septic odors occur in
the house, above the tank and drainfield, or escape from
the vent pipe. If the system is operating properly,
there should be no odors. If there are odors, it can be
an early warning sign that the system is failing.
Maintenance Tips
· Conserve
water. Fix leaks and drips. If you replace old fixtures,
install new "low flow" types.
·
Do not
overload the system -- this is the primary cause of
system failures. Early morning and bedtime are peak
water use times in the bathroom. Run dishwashers and
washing machines at other times of the day. Don't do all
the family laundry in one day.
·
Do not use a garbage
disposal or dump coffee grounds in the sink. Increasing
the load of solids into the tank decreases the capacity
and shortens the interval between pumpings.
·
Do
not pour fats and oils down the drain. They can build up
and clog the septic tank pipes.
· Put
paper towels, tissue, cigarette butts, disposable
diapers, sanitary napkins, tampons and other material in
a trash can, not the toilet.
· Use
normal amounts of detergents, bleaches, drain cleaners,
household cleaners and other products. Avoid dumping
solvents like dry cleaning fluid, pesticides,
photographic chemicals, paint thinner, or auto products
down the drain.
You do NOT need to add
any commercial products or yeast to your system.
Additives do not improve how well your system works.
There are always plenty of natural bacteria available to
do the job. (They come from YOUR digestive system.) In
fact, additives can damage your system by breaking up
the sludge and scum layers, causing them to flush out of
the tank and clog the infiltration bed. Additives that
say "Never worry about pumping your septic tank again"
are the worst!
· Direct
down spouts and runoff away from the septic field to
avoid saturating the area with excess water.
· Dense
grass cover and other shallow rooted plants are
beneficial over a septic field. However, do not plant
trees because large plant roots can clog or break the
pipes.
·
Avoid compacting the soil over the
infiltration area. Do not drive or park vehicles over
the area and don't build a shed or driveway in this
area. These activities can also crack pipes or cause the
distribution box to settle unevenly, meaning that
effluent will only flow into part of the drain field.
· Tanks
need to be pumped every two to five years, depending on
use. If the tank gets too full, particles of scum or
sludge will flush out of the tank. This material will
clog the drain tiles and cause the septic system to
fail.
·
Hire a
licensed professional (listed under "septic tank
cleaners") to pump the waste out of your tank. The tank
should be pumped out through the manhole, not the
smaller inspection ports. The tank should be cleaned
completely, leaving nothing in the tank. Make sure the
baffles are inspected and that the tank is checked for
leaks.
