---identifier: "/us/cfr/t40/s191.22"source: "ecfr"legal_status: "authoritative_unofficial"title: "40 CFR § 191.22 - Definitions."title_number: 40title_name: "Protection of Environment"section_number: "191.22"section_name: "Definitions."chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"subchapter_number: "F"subchapter_name: "RADIATION PROTECTION PROGRAMS"part_number: "191"part_name: "ENVIRONMENTAL RADIATION PROTECTION STANDARDS FOR MANAGEMENT AND DISPOSAL OF SPENT NUCLEAR FUEL, HIGH-LEVEL AND TRANSURANIC RADIOACTIVE WASTES"positive_law: falsecurrency: "2026-03-24"last_updated: "2026-03-24"format_version: "1.1.0"generator: "[email protected]"authority: "The Atomic Energy Act of 1954, as amended, 42 U.S.C. 2011-2296; Reorganization Plan No. 3 of 1970, 5 U.S.C. app. 1; the Nuclear Waste Policy Act of 1982, as amended, 42 U.S.C. 10101-10270; and the Waste Isolation Pilot Plant Land Withdrawal Act, Pub. L. 102-579, 106 Stat. 4777."regulatory_source: "50 FR 38084, Sept. 19, 1985, unless otherwise noted."cfr_part: "191"---
Identifier
/us/cfr/t40/s191.22
Currency
2026-03-24
Positive Law
No
Updated
2026-03-24
Chapter
Environmental Protection Agency
Authority
The Atomic Energy Act of 1954, as amended, 42 U.S.C. 2011-2296; Reorganization Plan No. 3 of 1970, 5 U.S.C. app. 1; the Nuclear Waste Policy Act of 1982, as amended, 42 U.S.C. 10101-10270; and the Was... The Atomic Energy Act of 1954, as amended, 42 U.S.C. 2011-2296; Reorganization Plan No. 3 of 1970, 5 U.S.C. app. 1; the Nuclear Waste Policy Act of 1982, as amended, 42 U.S.C. 10101-10270; and the Waste Isolation Pilot Plant Land Withdrawal Act, Pub. L. 102-579, 106 Stat. 4777.
# 191.22 Definitions.Unless otherwise indicated in this subpart, all terms have the same meaning as in subparts A and B of this part.*Public water system* means a system for the provision to the public of piped water for human consumption, if such system has at least fifteen service connections or regularly serves at least twenty-five individuals. Such term includes:(1) Any collection, treatment, storage, and distribution facilities under control of the operator of such system and used primarily in connection with such system; and(2) Any collection or pretreatment storage facilities not under such control which are used primarily in connection with such system.*Total dissolved solids* means the total dissolved (filterable) solids in water as determined by use of the method specified in 40 CFR part 136.*Underground source of drinking water* means an aquifer or its portion which:(1) Supplies any public water system; or(2) Contains a sufficient quantity of ground water to supply a public water system; and(i) Currently supplies drinking water for human consumption; or(ii) Contains fewer than 10,000 milligrams of total dissolved solids per liter.