Understanding your system is essential to proper operation
and maintenance. The University of Minnesota publishes a "Know your Septic System Guide" and has information for septic system owners.
How it works:
The Septic Tank receives the wastewater from the
household plumbing. In the tank, the solids are separated
from the liquid. Here, naturally occurring bacteria decomposes
food particles and human waste and the remaining
solids settle to the bottom until they are pumped out on a
regular basis. The tank will have an inspection pipe for
monitoring of the tank and a manhole for access when
pumped. The size of the tank is based on the home’s
potential water use and types of appliances installed.
When the capacity of the tank is reached the excess liquid
flows, or is pumped, over into the drainfield.
The Soil Treatment System (drainfield), which is typically
a network of perforated pipes surrounded by small
rock and soil. The liquid, which contains pathogens (disease-
causing organisms), nutrients such as phosphorus,
and fine solids, is cleansed naturally by bacteria as it
percolates down through the soil. The design of the treatment
system (trench, mound, etc.) is based on the soil
conditions on your property, which must allow for at least
three feet of unsaturated soil for the wastewater to percolate
through for proper treatment. The correct type of
system needed for your property will be determined by a
state-licensed septic designer. Where gravity flow is not
enough to move the liquids from the tank to the soil
treatment system, pumps or lift stations are common—
this is typical with mound systems.
Who regulates?
The design, inspection, and installation of
septic systems are regulated by your county and must be
done by professionals licensed by the state. Lists of
licensed professionals and permits for septic system installation
can be obtained from the Planning & Zoning Office.
What records are required? A septic system must have a
“Certificate of Compliance” indicating it meets the county’s
SSTS and Wastewater Ordinance, sometimes referred to
as being “up-to-code.” A Certificate is good for five years
from the date of original installation and it must be
renewed every three years thereafter.
When are inspections required?
If you are applying for a
building permit for new construction, a compliant septic
system is required. A building permit for any addition to
current buildings, including a deck or garage—attached or
non-attached, requires a current Certificate of Compliance
for the septic system. If one is not on record or it is not
current, an inspection of the septic system will be required
and, if the system is found to be noncompliant, modification
or replacement of the system may be necessary
before a building permit is issued.
