ABSTRACT
Rapid infiltration systems are designed for high rates of infiltration with the primary objective being efficient wastewater treatment. In an overland flow process, wastewater is applied across the upper reaches of sloped terraces and allowed to flow across vegetated surfaces to runoff collection channels. The continuing sludge-on-land research and risk assessment analyses have been driven by the need to dispose of increasingly large volumes of biosolids, due to population growth and improved wastewater treatment, in an environmentally acceptable manner. The appropriate rates of application of biosolids to agricultural lands are limited by three loading rate components: the agronomic rate, the annual pollutant loading rate, and the cumulative load. Land application emphasizes relatively low-rate applications of stabilized sewage sludge to agricultural, forested, or reclaimed lands. A stabilized sludge is one that has been processed from a raw state in order to reduce pathogen content and the potential for offensive odors.
