SEPTIC TANK SYSTEM USERS GUIDE
OPERATING AND MAINTAINING YOUR SYSTEM
If you own a septic tank system you are an operator of a highly efficient wastewater treatment system! A properly designed, constructed and operated septic tank system treats your wastewater more completely than a conventional municipal treatment plant and returns it safely to the ground water resource. Your system represents a significant investment that you will want to protect. Proper operation and regular maintenance will increase its life and effectiveness. Use this guide to understand how to properly care for your onsite wastewater treatment system.
An
onsite wastewater treatment system typically consists of a septic tank and subsurface
infiltration field or “drainfield”.
It is designed to treat both “black water” (toilet wastes) and “gray water”
(wastewater from sinks, baths, laundry and water softener brines) so that they
may be safely discharged to the soil for recharge to the ground water.
When
wastewater is discharged from your home, it enters the septic tank. This tank provides partial treatment of the
wastewater. It is a water-tight tank
that holds the wastewater for up to a day or more. During this time, solid particles suspended in the wastewater are
removed. Heavier solids settle to the
bottom of the tank to form a sludge
layer. Buoyant solids such as greases
and oils float to the top to form a scum
layer. It not removed, these solids
could clog the infiltration field.
The
sludge and scum are stored in the tank and undergo digestion or reduction in volume by facultative and anaerobic microorganisms
that can thrive without oxygen.
In
the process, methane, carbon dioxide,
hydrogen sulfide and other gases are released that are vented from the tank
through the plumbing stack vent on your house roof. Only about 40% of the sludge and scum volume can be reduced
through digestion so the contents of the tank must be pumped periodically and
disposed of at a treatment plant or licensed land spreading site.
The
subsurface infiltration field absorbs the septic tank effluent and completes
the treatment as the liquid percolates through the soil to the ground
water. The field typically consists of
a series of trenches or a bed. They are
excavations in permeable soil that have been partially filled with large
gravel. A perforated pipe is buried in
the gravel to distribute the septic tank effluent onto the infiltrative surface
of the soil. The gravel is covered with
natural soil.
Other
subsurface infiltration fields may be used for different site
characteristics. At-grades and mounds are
similar infiltration fields except that they are built on or above the natural
soil surface. They provide additional
soil materials where there is insufficient depth of unsaturated soil to insure
satisfactory treatment.
The
infiltration system provides excellent treatment. The soil acts as a biological filter that removes nearly all
harmful parasites, bacterial and viruses.
It is also very effective in removing toxic organics that may be in the
wastewater from household cleaning products.
It will not remove nitrate nitrogen, however. Elevated nitrates in the ground water can raise health concerns
if found in wells used for drinking water supplies. However, agricultural practices are usually the source of the
nitrates rather than properly silted onsite treatment systems.
TAKING CARE OF YOUR SYSTEM
Proper
care and regular maintenance will increase the effectiveness and life of your
system. The two most important things you
can do are to use water wisely and regularly pump your septic tank. Some helpful suggestions are provided below.
Conserve Water
The
less water you use, the less wastewater your system must treat.
q Repair leaking faucets and toilets immediately.
q Wash only full loads of laundry and wash throughout
the week rather than on one day.
q Use low volume flush toilets and water conserving
showerheads.
q Limit your automatic water softener regeneration cycle
frequency.
Eliminate Clear
Water
Clear water is rain water, snow melt or other “clean” water that doesn’t belong in your system.
q Pump foundation drains into the yard, not into your
septic tank.
q Direct gutter downspouts away from your system.
q Grade your yard so surface runoff is directed away
from your system.
Minimize Waste
q Don’t put anything down the drain that could be
disposed of some other way.
q Do not flush disposal diapers, sanitary napkins,
tampons, condoms, paper towels, cigarettes or other non-degradable products
into your system.
q Avoid pouring grease, sauces, gravies, etc. down the
drain.
q Limit the use of your garbage grinder.
q Do not dispose of oils, paints, paint thinners, brush
cleaners or other harmful chemicals into your system.
q Septic tank additives such as enzymes, bacterial
preparations, degreasers, etc. are not necessary for a well functioning system.
Pump and Inspect
Septic Tank
The
more you put into your tank, the more frequently it will need to be
pumped. Under normal use, pumping
frequencies range from 2 to 3 years.
q Hire a licensed pumper to inspect and pump your tank
every three years.
q Have your tank inspected for leaks, cracks and broken
baffles when it is pumped.
q Do not enter the septic tank because the gases in the
tank are dangerous and potentially lethal.
Protect
the Drain Field
Protect
your drain field from damage because if it fails, it may have to be
replaced.
q Prevent driving over the field, building over it or
compacting the soil in any way.
q Plant only grass over the field.
q Check inspection pipes monthly for standing water.
Keep Accurate Records
q Records of your system are important for scheduling
timely maintenance and trouble shooting problems.
q Keep a drawing of your system showing exact locations
of tanks and infiltration field.
q Record of septage pumping.
q Description of problems and repairs.
WHAT TO DO WHEN THERE IS A PROBLEM
If
your toilet does not seem to flush properly, your drains are backing up or you
notice wastewater on the ground surface you have symptoms of a hydraulic
failure. When you first notice any of
these, do the following:
q Eliminate all unnecessary water use immediately.
q Call a licensed pumper to pump the tank and empty the infiltration field if possible.
q Hire a professional to advise you of appropriate corrective measures.