{"data":{"id":"us/40-cfr-141.501","jurisdiction":"us","citation":"40 CFR 141.501","heading":"Who is subject to the requirements of subpart T?","body":"You are subject to these requirements if your system:\n(a) Is a public water system;\n(b) Uses surface water or GWUDI as a source; and\n(c) Serves fewer than 10,000 persons.","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER D—WATER PROGRAMS","PART 141—NATIONAL PRIMARY DRINKING WATER REGULATIONS","Subpart T—Enhanced Filtration and Disinfection—Systems Serving Fewer Than 10,000 People"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-40.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:04Z","sha256":"4af188cd1e3ea62ca98c678e4fe26d572aa154734432e828c54f37cfe6a39a49","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-141.500","next":"us/40-cfr-141.502"},"notice":"GroundRules: Original legal text. Not legal advice."}