Systems serving 100,000 or more users or a wholesale system connected to a system of that size are Schedule 1. Systems serving 50,000-99,999 users or a wholesale system connected to a system of that size are Schedule 2; and systems serving 10,000-49,999 users or a wholesale system connected to a system of that size are Schedule 3. Any system serving fewer than 10,000 users is on Schedule 4.
For additional guidance on the Long Term 2 Enhanced Surface Water Treatment Rule please visit http://water.epa.gov/lawsregs/rulesregs/sdwa/lt2/index.cfm.