An Overview of the Effects of a Two-Stage Earthen Manure Storage Lagoon on Groundwater Quality in North Central Iowa-Impact and Assessment to Local Public Health and Safety.

Kirkwood Community College, located in central Iowa, currently uses a two-stage anaerobic lagoon system for treating agricultural swine wastes. These wastes are the result of an intensified hog production facility located on the campus. The production buildings act both as a classroom and as a research facility for swine development. The material in this report focuses on the environmental impact of the two lagoons located on the college's property and adjacent to the hog production facilities. The lagoon site has five shallow aquifer monitoring wells and three additional "geoprobe" monitoring wells installed for measuring aquifer quality. Planning and final construction of the lagoons was supervised by the Iowa Department of Natural Resources (IDNR) and finished prior to October, 1993. The initial water quality sampling program began in late October, 1993. The sampling results of each monitoring well are presented and discussed. The implications of the lagoons on the surrounding environment and human health are also considered in this report. Based on the data presented here, the lagoons do not adversely affect the quality of local groundwater resources, but they do potentially cause eutrophication in the adjoining stream. However, additional aquifer monitoring and research needs to be performed at the hog production site. In addition to the chemicals monitored by the Iowa Department of Natural Resources, new constituents should also be monitored in the local aquifer and surface water resources to protect the environment and public health. Chemicals such as organic and synthetic feed additives and amendments are used in swine production with relatively little scientific evidence on their corresponding fate and transport characteristics. The effect of these presently unmonitored chemicals on local water quality will not be discussed in this paper.