ORIGINALLY WRITTEN ALMUS R. GANTZ, RETIRED SOIL CONSERVATIONIST – MARION
Recent editorials in the Marion County Record have contained erroneous statements about the information and data in the Marion County Soil Survey publication. The soil survey is an inventory of the soils, made in the field, acre by acre. It is not a soil fertility test.
The texture of the soils are checked to determine if they are sand, silt or clay. Soil augers, a hydraulic soil probe mounted on a pickup that can bring up a core sample from a depth of six feet, and a spade are used to get a complete sample from the surface to the rock layers below.
The depth of soil and changes in soil texture are determined for the topsoil, subsoil, and at the depth where the soil meets the parent material or rock. Density of the soil is recorded, providing information concerning how well the soil absorbs water.
Slope of the land is measured to see if the area is flat, sloping or steep. Is it upland soil subject to erosion, or bottom land soil subject to flooding? Soils of the same characteristics are grouped together and named.
When making the survey, the soil scientist locates on an aerial photograph the boundaries where different soils join. This is done until the entire area is mapped and the soils identified.
This soil information, once determined, does not change any more than the rock below it changes.
From the soil survey information, it can be determined if the soil is suitable for many different uses. This can be found in the data pages of the soil survey. Page 97 contains data concerning the use of various soils for a sanitary landfill.
Clime, a major soil found at the site of the old landfill southwest of Marion, is also one of the major soils at the Hett quarry. The other clay soils there are very similar. When dry, they will not pack as a seal for trash in a landfill. When wet and then dry out, they crack and allow the next rain to seep on through the trash and the cracks in the rock of the quarry. The whole area is subject to contamination. With the volume of trash expected for a regional landfill, the problems of the old landfill would be mild compared to the quarry site.
The spring at the golf course and the one in the park could be affected by leachate coming through the limestone formations. Drainage would have a few hundred feet to travel to get into Clear Creek and on downstream.
The soil survey indicates the soils at the quarry are poor for use as a cover for trash and the rock allows a lot of cracks for seepage water to follow. See the map, Page 36, land section 12, for quarry site soil survey in the Soil Survey book.