GEOLOGIC MAPPING USING GIS TECHNOLOGY ASSISTS IN THE SITING OF ANIMAL CONFINEMENT OPERATIONS AND MANURE APPLICATION AREAS
D. J. Quade, E. A. Bettis III, and J. D. Giglierano
Proper siting of animal confinement operations (ACOs) and areas for manure application is essential to insure that these activities do not adversely affect the quality of water resources. Geologic deposits and related soils vary in their ability to react with potential contaminants and to contain or transmit contaminants to groundwater, surface water, and drinking water resources. Existing information provides generalized models of the sequence of sediments and hydrogeologic conditions expected beneath the landscape. These models are the basis for generating maps that show the distribution of geologic materials to specified depths across an area. In the past, large areas of the Late Wisconsin Des Moines Lobe (DML) in Iowa were predominantly mapped using morphostratigraphic concepts. However, for the most recent DML STATEMAP project we have opted to apply landform sediment assemblage (LSA) mapping concepts to glaciated terrains; a mapping concept we have previously employed to map large valleys. Geographic information system (GIS) analysis of the LSA maps and soil survey data provide preliminary contamination susceptibility assessments that are useful for siting ACOs and manure application areas. A GIS analysis of geologic and soil information from Hancock County, located in the DML region of north-central Iowa, shows that groundwater susceptibility to contamination from point and nonpoint sources varies across the county. Susceptibility assessed at the county-wide scale provides up-front information that local governments, state regulators, and producers can use to make siting ACOs and manure application areas more efficient and effective.