A home's septic
system consists of two main parts, the septic tank and the soil
absorption area, also called a leach field. The absorption area
shouldn't be relegated to an afterthought because many septic system
failures originate in the field. Gain an understanding of how your
septic drainage system works with regards to the soil absorption area
to better be able to safeguard it.
Septic Soil
Absorption Area Basics
The septic tank
collects the organic matter and other floatables that the household
flushes into the system. It holds onto the water long enough for
solids to settle to the bottom. The result is three layers inside the
tank - the settled solids, water, and a layer of sludge on the top
made of grease and oil.
The tank then
discharges the effluent, or the remaining liquid in the tank, into
the soil absorption area. A system of perforated pipes or other
release units slowly let the effluent leach into the soil. The soil
further removes pathogens and impurities from the effluent through
the process of percolation. The water is then pure enough to enter
the water table.
Never flush
chemicals such as paint thinner or varnish because they can
contaminate the soil and even leach into the groundwater.
Septic Soil
Absorption Area Size and Placement
The size of your
household will determine the size of the tank, which will determine
the size of the soil absorption area. A factor that goes into sizing
the leach field is the soil's rate of percolation. A good rate might
be three minutes for one inch, while a bad rate might require a full
hour. Septic experts are the best at these determinations.
Naturally, the
leach filed area must be near the septic tank. What's more, the
septic system works primarily via gravity. Therefore, the field
should be at a lower elevation than the tank, which ideally is at a
lower elevation than the house. If such a location isn't feasible,
homeowners have to invest in a lift station or pump to move the water
from the tank to the absorption area.
Divert runoff
water, such as from roofs and patios, to avoid soaking the leach
field. Soaked soil offers a lower percolation rate.
Signs of a
Failed Soil Absorption Area
A septic system
relies heavily on the soil in the absorption area percolating the
effluent. When the system handles primarily bathroom waste, the soil
has no problem with percolation. Unfortunately, grease and oil
floating on top of the water flow into the field. When they enter the
soil, they settle and bind the particles to make clay, which reduces
percolation rates.
An early
harbinger of a failing field is the presence of suddenly lush, green
grass, which indicates the lawn is receiving more nutrients from the
waste below. Spongy grass or muddy soil indicates water from the
drains is backing up. Strong odors around the septic system area are
the biggest hint the soil absorption field is failing.
Safeguarding Tip:
Avoid pouring grease and oil into your sink.
Location of
Your Soil Absorption Area
If you have your
house custom-built, you may be involved in the process of locating
the septic system. However, many people buy homes with an existing
system. You'll want to know where your system to watch for signs of
failure.
The realtor or
selling homeowner can usually show you where the soil absorption area
is located. You may also have a "record drawing" or "as
built" diagram available to you through your local county
office. If you don't have such road maps, look at the areas lower
than the house for manholes or shallow, parallel depressions, a
likely sign of the leach field trenches.
Avoid driving
onto the absorption field or building structures on top. The weight
will compact the soil, which inhibits its ability to percolate
effluent.
Once you have the
basics of how the soil absorption area works within your septic
system, sign up for a maintenance plan to keep the entirety in
working order. Pete's
Outflow Technicians
offer a variety of septic tank cleaning
services.
