WHAT IS A SEPTIC
tank is a watertight vessel that receives wastewater. The tank is designed to separate water from solids. Heavy materials sink to the
bottom while lighter substances float. Accumulated solids have to be
pumped out periodically. Some biological degradation occurs in the tank.
The clarified water leaving the septic tank goes into the leach field.
tank traps solid materials. Some of it sinks to the sludge layer and
some of it floats. Anaerobic bacterial decomposition occurs in the tank
to reduce solids to gasses, water, and more bacteria. Clear effluent
leaves the tank, reaches the distribution box, and is evenly spread over
the leach field. More bacterial decomposition takes place in the leach
field. In theory, the top 4-5 feet of soil polish the effluent so it
will not contribute to ground water contamination the way a cesspool
will. The Hawaii State Department of Health required homes in rural areas after 1992
to be built
with septics instead of cesspools. The only exception on Maui is around
Keokea, where it was deemed that there were no potential drinking water
resources to pollute.
A typical leach field or absorption bed consists of a series of shallow
trenches that are filled with gravel and have a perforated pipe, or an
"infiltrator" chamber system that distributes the clarified wastewater. Bacteria, or "biomass" grows and consumes the
nutrients left from the septic tank. It is this action that prevents
degradation of groundwater beneath septic systems, and it is this action
which does not occur in cesspools that led the state to require septic
systems to be installed instead of cesspools.
average cost of a septic system varies. Some soils,
like Haiku, have a lot of clay. It takes a long time for water to seep
down through the clay, so more leach lines are required. The more leach
lines the system requires, the more it costs. The opposite is true in
Hana. The soil mixed with cinders there allows water to run right
The cost to
pump a septic tank is approximately $330.
system is individually engineered for your lot. The number of bedrooms, the size and configuration of the lot, and perk rate are all
used to determine final system design. The perk rate represents how fast
the water can seep through your soil, it is higher with more seepage.
state will only allow one Individual Wastewater System (IWS) per 10,000
square foot lot. And, there can be only five bedrooms per IWS. The state
determines wastewater flows based on the number of bedrooms in a
dwelling. You can build on an existing lot that has less than 10,000 sf
so long as it was in existence before state IWS rules became law in
September of 1991. If you want more than five bedrooms, you must have
20,000 sf or more land. You would be required to install two septic
systems. The state requires floor plans to be submitted for their
review. An examination is made to determine that a "den, study,
rumpus room, etc" cannot be readily converted into a bedroom.
permit applications, in areas where a septic system is required, must be
submitted with engineered septic systems attached. There is usually a
backlog of applications both at the engineers office and at the State
Department of Health. A month should be allowed to have approved septic
plans to submit with the building permit application.
lots of time. The State does change the rules. Check before you start to
make sure you are playing by today's rules.