There are three main sections on the report. The first
section contain the name and mailing address of the property owner, as well as
the legal description of the property location.
The second section describes the recommended system for
your property. In residential construction, the system is sized based on the number
of bedrooms in the home. The code derived daily flow is calculated
based on 75 gallons per day per person. It is assumed that there are 2 people
per bedroom in the home. The recommended design loading rate is based
on the texture and structure of your soil. Loading rates range from .2 to .8.
The higher the loading rate for your soil the smaller the system you will
need. Soils which contain large amounts of sand and gravel generally have the
highest loading rates. The absorption area required is the size of the
septic field. It is calculated based on the daily flow and the loading rate.
The maximum design loading rate is the highest loading rate allowed by
state code. In most cases the recommended and maximum loading rates are the
same. The recommended infiltration elevation is the depth at which the
system is installed. Recommendations for specific feature in your system are
listed in additional design considerations. The parent material
is either glacial outwash, a more course soil, or glacial till, a finer soil.
For properties within the 100 year flood plain the flood plain elevation
is included. The last portion of this section contains the six options for
disposal of your waste water. A box is marked indicating whether your soil is
suitable for each type of system. You, as the property owner, along with your
septic system installer and the county inspector can determine which of the
suitable systems best meets your needs.
The third section contains a detailed description of the
soils found at each boring location. Each layer of soil is a horizon.
The depth in inches refers to the thickness of the layer of soil. The dominant
color Munsell is the soil color based on the Munsell color chart. Mottles
are colors in soil caused by the presence of water. The quantity, size,
contrast and color of the mottles give an indication of how often and how long
water is present. The texture describes the mixture of sand, loam, clay
and silt found in the soil. The structure of soil determines how the
soil sticks together. The texture and the structure are the key elements in
determining the size of your system. Consistence describes how loose or
compacted the soil is. The boundary is the transition area between the
horizons. The quantity and size roots are also indicated. The GPD/ft2
is the loading rate for that horizon. Also indicated in this section is the ground
elevation at that boring site and the depth to limiting factor. A
limiting factor could be high ground water or bedrock. Your system must be
installed at least three feet above this point.
This sample test was performed for Joe Homebuilder who is
currently living at 123 Main Street in Anytown. The property where the test
was performed was located on lot #5, CSM# 4015 in the town of Erin. Joe
Homebuilder is planning to build a new home with four bedrooms. Based on two
people per bedroom each producing 75 gallons of waste water per day, the
Homebuilder’s gpd is calculated to be 600 (2x4x75). The soil tester has
recommended an infiltration surface elevation of 94ft. At that depth Joe Homebuilder’s soils have a loading rate of 0.7 for beds or 0.8 for trenches.
Based on these loading rates, he will need an absorption area of 857sq ft if a
bed is installed or 750 sq ft if trenches are used. Mr. Homebuilder and the
septic system installer will choose the best system design for his property
from the options designated as suitable on his soil report. In this case he
could install a conventional, mound, in-ground pressure or at-grade system.
In the first boring dug on Joe Homebuilder’s property the
first layer of soil was 10 inches deep. The soil color is located on page 10YR
in Munsell color book. The color chip is 3/3. There were no mottles present in
the soil. The texture is loam. The structure is moderate, fine, subangular
blocky. The consistence is moist, very friable. The boundary is clear, smooth.
The roots are moderate, fine. The loading rate for this horizon is 0.5 for
beds or 0.6 for trenches.