The federal Part 503 rule establishes requirements for land applying sewage sludge to ensure protection of public health and the environment when sewage sludge is used for its soil conditioning or fertilizing properties. This chapter highlights key aspects of the Part 503 rule as they pertain to land application of sewage sludge, including general requirements, pollutant limits, management practices, pathogen and vector attraction reduction, frequency of monitoring, recordkeeping, and reporting. All sewage sludge applied to land must meet Part 503 ceiling concentration limits for the 10 regulated pollutants. Ceiling concentration limits are the maximum allowable concentration of a pollutant in sewage sludge to be land applied. A cumulative pollutant loading rate is the maximum amount of a pollutant that can be applied to a site by all bulk sewage sludge applications made after July 20, 1993. Monitoring is intended to ensure that the land-applied sewage sludge meets applicable criteria after its quality has been initially demonstrated.