{"data":{"id":"us/40-cfr-141.171","jurisdiction":"us","citation":"40 CFR 141.171","heading":"Criteria for avoiding filtration.","body":"In addition to the requirements of § 141.71, a public water system subject to the requirements of this subpart that does not provide filtration must meet all of the conditions of paragraphs (a) and (b) of this section.\n(a) Site-specific conditions. In addition to site-specific conditions in § 141.71(b), systems must maintain the watershed control program under § 141.71(b)(2) to minimize the potential for contamination by Cryptosporidium oocysts in the source water. The watershed control program must, for Cryptosporidium:\n(1) Identify watershed characteristics and activities which may have an adverse effect on source water quality; and\n(2) Monitor the occurrence of activities which may have an adverse effect on source water quality.\n(b) During the onsite inspection conducted under the provisions of § 141.71(b)(3), the State must determine whether the watershed control program established under § 141.71(b)(2) is adequate to limit potential contamination by Cryptosporidium oocysts. The adequacy of the program must be based on the comprehensiveness of the watershed review; the effectiveness of the system's program to monitor and control detrimental activities occurring in the watershed; and the extent to which the water system has maximized land ownership and/or controlled land use within the watershed.","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER D—WATER PROGRAMS","PART 141—NATIONAL PRIMARY DRINKING WATER REGULATIONS","Subpart P—Enhanced Filtration and Disinfection—Systems Serving 10,000 or More 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":"bd755122d19735b9a6c70543c3ff32ba373db82c32ce92339e83338ea3a1b978","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-141.170","next":"us/40-cfr-141.172"},"notice":"GroundRules: Original legal text. Not legal advice."}