Title 42 › Chapter CHAPTER 6A— - PUBLIC HEALTH SERVICE › Subchapter SUBCHAPTER XII— - SAFETY OF PUBLIC WATER SYSTEMS › Part Part B— - Public Water Systems › § 300g–4
States or the EPA can allow public water systems to meet drinking water rules in a different way when the system cannot meet a contaminant limit because of the source water. A state with primary enforcement power may give a variance if the system installs the best available technology or treatment the EPA has identified (the EPA may set different technologies for different system sizes). The state must find the variance will not create an unreasonable health risk, set an enforceable schedule for meeting the rule and for any extra controls, give public notice and a hearing, and tell the EPA why the variance is needed. If a state does not have enforcement power, the EPA has the same authority. Any person can ask the EPA for a variance when an alternative treatment works at least as well as the required technique. Special rules apply to small systems. Variances may be given to systems serving 3,300 or fewer people, and to systems serving more than 3,300 but fewer than 10,000 people with EPA approval. The system must use an EPA-identified “variance technology,” operate it properly, and meet affordability and health-protection tests. Compliance must occur within 3 years, with up to 2 extra years in limited cases. The EPA must review variances on set schedules (initial reviews and periodic reviews; see exact deadlines in the law), may object or revoke variances after notice and hearing, and may enforce schedules like drinking water rules. The law also sets dates for EPA rulemaking and excludes some older or microbial rules from these variances.
Full Legal Text
The Public Health and Welfare — Source: USLM XML via OLRC
Legislative History
Reference
Citation
42 U.S.C. § 300g–4
Title 42 — The Public Health and Welfare
Last Updated
Apr 6, 2026
Release point: 119-73