What is a Soil Test?
A soil test is performed to determine the size, location and
type (conventional or mound) of wastewater treatment system that will be
installed at your home. After viewing the property and discussing the
homeowner’s needs, the soil tester typically digs three to five holes with a
backhoe to view and handle the soils to determine the soil’s drainage
capability, the average high groundwater mark and signs of bedrock.
will look for and describe the layers of soil or horizons. The texture and
structure of the soil is examined to determine how well the soil will drain. If
the soil is impermeable you will create a pond of sewage in your yard. Loose
soils do not allow adequate time for treatment to take place. He will also look
for irregular orange, yellow and gray spots or mottles which are the result of
chemical reactions in the soil as the seasonal water table rises and falls. The
highest point at which mottling is observed is the estimated high groundwater
The bottom of your septic system must be at least three feet above your
sites limiting factor. If this cannot be achieved with an inground system then a
mound system is installed. A mound system artificially creates the proper soil
conditions above ground.
These soil conditions, as well as features of your lot (such
as slope and home placement) determine the type and location of your system.
After analyzing the soils, the soil tester will prepare a Soil and Site
Evaluation Report. This report includes a detailed description of the soils as
well as a site plan.
The site plan is a drawing of the property showing the
location of the borings, the residence or proposed residence and any other
relevant feature such as the location of the well. The original copy of this
report is submitted to the agency which regulates septic systems in the county
in which the property is located. The information on this report is used by the
septic system installer to design the system and to pull the necessary permits.