Marine and Land Electrical Resistivity Survey for Assessing Water Quality Issues in Carter Lake, Iowa & Nebraska

A geophysical site characterization was completed by and consisted of a land and water borne resistivity survey. Carter Lake (the Site), is located adjacent to the Omaha International Airport, and is bisected by the Nebraska-Iowa state line. The geophysical survey was designed to assist in the characterization of the local hydrogeologic framework which affects the water quality of Carter Lake. The objective of the geophysical survey was to assist in identifying lithologic units with high hydraulic conductivities (sands and gravels), aquitards (silts and clays) peripheral and within Carter Lake. Differentiation and delineation of site lithology, with respect to, electrical resistivity data provided additional information for understanding potential water seepage in delineated site areas. The data presented herein in conjunction with known hydrogeologic parameters was used to contribute to the development of a preliminary design for the watershed and in-lake treatment alternatives identified in the area Management Plan to assist in improving the overall water quality of Carter Lake. This paper presents a summary of the collection methodology, interpretation, and findings of the resistivity data collected for this study. The resistivity data was collected from two Site areas: land data collected from, the southern perimeter areas; and water borne resistivity data collected from the in-lake areas.