The ERS consists of bureaucrats, scientists, and a large number of field workers, with branches located on every Earthclan colony world. ERS professionals are well-paid and held in high regard in Terragens society; many high-ranking Terragens officials served in the ERS. Non-professionals consist of students, Probationers, drifters, and Workfare recipients, who receive only meager pay but are eligible for other benefits. Field workers and scientists on planets such as Garth may be organized into teams for certain projects, and may perform their duties at ecological management stations. ERS workers are also considered part of Earthclan's military reserves.
Duties performed by ERS workers include planting trees, cleaning up old landfills and strip mines, and managing the relocation of existing wildlife, as well as the introduction of Earth species which may benefit the planetary ecosystem.