Landspreading: An Alternative for Sludge Disposal

Abstract

One characteristic of the 1970s is an increased awareness of the finiteness of our natural resources and their ability to assimilate the by-products of an industrial society. A result of this increased awareness has been the passage of the Federal Water Pollution Control Act Amendments of 1972 (P.L. 92-500, 18 Oct. 1972) with the expressed goal that the national waterways will receive zero discharge of pollutants by 1985. One source of such pollutants has been the discharge of effluent from municipal wastewater treatment plants. As municipalities improve the environment quality of their effluent they are faced with another problem: how to dispose of sludge which is produced from providing cleaner effluent in an environmentally acceptable manner. In 1970, four million tons of sludge were produced, with a projected production of eight million tons by 1985 (Council for Agr. Sci. and Tech.). Spreading sludge on cropland has received renewed emphasis not only as a low cost disposal method but also as a source of fertilizer nutrients. The objectives of this study are to (a) develop a model which optimally allocates treated sewage sludge to cropland and (b) apply the model to several communities in order to analyze the benefits and costs of using sewage sludge as a fertilizer resource under a variety of settings.