Impact of Long-Term Application of Wastewater

Environmental regulatory agencies are applying more stringent guidelines to the discharge of wastewater effluents while also promoting the reuse of treated wastewater. Therefore, we can expect slow-rate land application to become an integral part of more treatment systems in the future, especially for the arid and semiarid southwest region of the United States. Yet, as common as land application systems are in the United States, design of these systems is still less than optimum. Much of the problem is the lack of communication between the design engineers and the agriculturalists involved with the systems. Often the agriculturalists forget that the purpose of the land application site is treating wastewater and not maximizing profits from the crop being produced. On the other hand, engineers forget that "good agricultural practices" are necessary for a long-term, effective land treatment system. When a land application system for secondary treated municipal wastewater is properly designed, both from the standpoint of good engineering principles and good agricultural practices, the system can be operated successfully for many years without posing a threat to the environment.