How is the population determined in order to categorize systems into the schedules? Are all the populations of the systems in a combined distribution system added together or is the schedule based on the single largest system in the combined distribution system?

If you are a consecutive or wholesale system (i.e., sell or buy finished water to or from another water system), your schedule is based on the population served by the largest system in your combined distribution system. If you are not a consecutive or wholesale system, your schedule is based on the population served by your individual system.

For additional guidance on the Stage 2 Disinfectants and Disinfection Byproducts rule please visit http://water.epa.gov/lawsregs/rulesregs/sdwa/stage2/regulations.cfm.