Strict discharge requirements for a nearby stream may be one compelling reason to consider irrigation. Meeting discharge limits may require a complex treatment process, high electrical or chemical costs, or careful and specialized plant operation. A community may choose wastewater reuse through irrigation during the most critical times of the year, or even forego discharge altogether, rather than construct or upgrade a treatment plant to meet strict discharge requirements. Irrigation of treated wastewater may be more affordable than extensive wastewater treatment.
Wastewater for irrigation requires lower levels of treatment than for stream discharge, which yields another benefit--less sludge. Lagoon systems are often used to renovate wastewater before reuse. Lagoon systems have low labor requirements and no routine sludge handling requirements.
Being a long distance from a receiving stream may motivate a community to consider irrigation. Because excavating and laying long sewer lines can be the most expensive aspect of a wastewater treatment system, irrigating wastewater on nearby land may be more affordable.
Water and nutrients are needed in and around communities. When tied to irrigation, the nitrogen and phosphorus present in wastewater are considered valuable nutrients rather than contaminants. Because treated wastewater can be irrigated on turf, timber, and field crops, a number of irrigation sites can be considered, such as golf courses, parks, plant nurseries, and farm fields. Large communities can benefit from reusing even a portion of their wastewater both through savings in potable water demand for irrigation and reduced wastewater treatment costs.