Silvicultural Use of Wastewater Sludge
Generation of wastewater sludge in the United States has become a problem of increasing proportion, with annual production at 4 million tons in 1970 (Walsh 1976) and 7 million tons currently(Maness 1987). While population and industrial growth have contributed to this problem, legislation requiring higher standards of treatment for wastewater processed in the 15,378 wastewater treatment plants nationwide has been primarily responsible for the increased production of sludge (U.S. Environmental Protection Agency 1985). The Federal Water Pollution Control Act Amendments (P.L.92. 500) of 1972 cited land application of sludge as a major alternative for eliminating nutrient-rich discharges into surface waters (Morris and Jewel1 19ii). and early studies identified it as an, innovative, cost-effective, and environmentally sound recycling technology (Forster et al.1977).