Dye Tracing Animal Waste Effluent in the North Fork Basin, Southern Missouri

An investigation of a local karst system in Howell County, Missouri was conducted using fluorescent dye tracing techniques. This investigation was initiated after several local residents complained of "contaminated" water supply wells. It was determined that suspected contaminants may originate from a local dairy that periodically discharged large quantities of animal waste effluent into a losing stream. Howell County is located in the southern Missouri Ozarks, an area typified by extensive karst development. Relatively deep solution weathering of the bedrock results in rapid migration of surface water to the subsurface. Development of this system has resulted in the occurrence of springs, sinkholes, losing streams and other karst features of interest to this study. Prior to this investigation, hydrogeologic data in this area consisted of an analysis of the hydrologic characteristics of the basin and the major springs within. However data available for the area of the basin of interested was limited to a single dye trace and regional potentiometric surface mapping. Field reconnaissance revealed important information on geology, hydrogeology and geomorphology. Several springs with flow greater than 250 l/sec were identified as possible groundwater discharge points receiving recharge from the area of the dairy lagoon. The field reconnaissance coupled with the existing data allowed the formulation of a reasonable hydrogeologic model. The resulting information from this study established the existence of hydrologic connections from the dye injection site to two regional springs.