1. A spray dispersal system distributes the treated effluent on top of the soil surface. The effluent must be disinfected and meet secondary treatment standards. A spray system consists of a pump chamber and spray field. The spray field is constructed similarly to a lawn irrigation system. The area must have vegetation and be landscaped to minimize runoff and have adequate setbacks. Sprinkler heads should be low trajectory to minimize aerosol production. The application rate will vary with climatic conditions and soil type. Effluent applied to the land surface undergoes evaporation, transpiration by plants, and absorption into the soil.