Soil Report & Testing Requirements for Fragic & Mine Soils
After site investigations, soil studies, and reevaluation of soil testing requirements, it was determined that the Daviess County Health Department needed to change soil testing requirements for potentially fragic soils as well as mine soils. The Department now requires a minimum of two soil test pits per proposed on-site sewage system soil absorption field location on mine-spoil and any soil that may have fragic characteristics (including, but not limited to, the list of soils provided below and areas immediately adjacent to them). This requirement includes set-aside locations. All inspection pits for a single soil absorption field location must be described to the same depth. Borings should be used along with the minimum number of pits to verify the consistency of soil conditions across a site.
The pits must fall within opposing corners of a possible absorption field, and there should be a minimum of one pit per 50 feet of field. If there is a great deal of variation between the preliminary pits then additional pits, or at minimum multiple borings, should be done in the area to determine how the soil structure varies across the proposed absorption area. Each sampling location must be described to the same maximum depth in order for all of the\ descriptions to be useable in designing the minimum specs of an on-site sewage system. If samples are not described to the same depth, and conditions at one sample location require a system to go deeper than the other descriptions provide, then on-site sewage system specs cannot be properly developed for that site. This can lead to the Health Department requiring additional tests at that site. Soils immediately adjacent to a Soil Series that is known for having fragic characteristics must be investigated with pits as well because weakly developed fragic properties can extend out past where soil maps indicate by a few hundred feet at times.
On mine-spoil sites, all pits must be done to the same maximum depth for on-site sewage system specs to be issued and a design to be approved. The maximum depth of the test pits must be a minimum of 48 inches below the proposed absorptive surface in accordance with ISDH guidelines. If you find a layer of undisturbed soil under the shale, it must be described to a minimum depth of 30 inches. If the undisturbed soil found is a limiting layer, such as one with a firm, massive structure, then that location is likely to be unusable.
Soil Series Requiring Test Pits In Daviess County
- Strip Mines