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University of Nebraska–Lincoln

UNL Extension in Lancaster County

Natural Resources

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GIS In The Biosolids Program

by David Smith, UNL Extension Assistant

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At University of Nebraska-Lincoln Extension in Lancaster County, GIS (Geographic Information System) has been used to make the Biosolids Program more robust and easily managed. The many aspects of the program, which are mainly geographic in nature, are handled more efficiently by the use of GIS.

Crop Fields and Sites

Until the implementation of the GIS, fields that were involved in the program were recorded by using paper maps, usually drawn by the farmer, with corresponding information attached to the maps. The boundaries of the fields were somewhat subjective, and the information, such as total acres, was an approximation that was not completely accurate. Further, storage sites of biosolid materials were drawn on the map as the best approximation, and soil test sites could not be accurately recorded. Although these methods are adequate and do not violate any regulations, we wanted to make a more accurate and efficient database of this information, and this is being accomplished by using GIS and GPS. Using GPS, fields, storage sites, and soil test sites can be recorded with a very high degree of accuracy, and these GPS files can be easily converted into a GIS format for incorporation into our GIS.

These field sites are then attributed with pertinent information such as application rate, legal description, cooperator, crop, total acres, etc. which takes the place of the former paper records that accompanied the maps. This "fields" database has all the information for all fields as a complete GIS coverage that can be easily displayed, manipulated, and analyzed from the computer.

Base Maps

The fields are just one part of the entire Biosolids GIS. Many other pieces are being drawn together to make a complete picture of the landscape which will help in analysis and use of the GIS. We are using DOQQs (Digital Orthophoto Quarter Quadrangles) provided by the Nebraska Department of Natural Resources, as a base map to the entire GIS. These georeferenced aerial photos allow a user to orient themselves to known features on the ground and allow us to overlay the other databases in the GIS as successive levels of information.

Other Data Sources

The Biosolids Application Program has certain regulations that have to be met both at the federal and local level. These include a certain application distance from critical features in the landscape. For example, biosolids can not be applied within 200 feet of water(lakes, streams), wells, or public drinking supplies. Determining the locations of these features can be made more easy and efficient by using GIS. Databases of existing water and wells is being incorporated into the GIS to be used as a fast way to analyze a field in regards to these regulations. For instance, databases of water features (e.g. wells, lakes, streams, water supplies) can be overlayed on the coverages of the crop fields that will potentially have sludge applied to them. These water features can then be analyzed and a distance buffer constructed around them to determine the areas off-limits to biosolids. The analysis would determine if the field is acceptable for biosolids application and the output would be a map of the field which shows the sections of the field where sludge could be applied.

We are in the process of using GIS in other scenarios in the Biosolids Program, and see the benefits of faster analysis time, accuracy of records, and the ability to perform extensive analysis that GIS provides.

Equipment and Software

We use IBM compatible PCs at the University of Nebraska Cooperative Extension in Lancaster County for hardware needs. GIS software is ArcView 3.0 and PC Arc/Info 3.5.1, both products of ESRI, Earth Systems Research Institute, Inc., Redlands, CA.

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PHOTO Credit: Vicki Jedlicka

Lincoln's biosolids recycling program is a joint collaboration between the City of Lincoln, Public Works and Utilities Department and University of Nebraska-Lincoln Extension in Lancaster County with assistance from the University of Nebraska Agronomy Department, Lincoln/Lancaster County Health Department and the Natural Resources Conservation Service.

Contact Information

University of Nebraska-Lincoln in Lancaster County
Barb Ogg or David Smith
Web site:
444 Cherrycreek Road, Suite A, Lincoln, NE 68528 | 402-441-7180