40 CFR 141.173 - Filtration.

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There is 1 rule appearing in the Federal Register for 40 CFR 141. View below or at eCFR (GPOAccess)
§ 141.173 Filtration.
A public water system subject to the requirements of this subpart that does not meet all of the criteria in this subpart and subpart H of this part for avoiding filtration must provide treatment consisting of both disinfection, as specified in § 141.72(b), and filtration treatment which complies with the requirements of paragraph (a) or (b) of this section or § 141.73 (b) or (c) by December 31, 2001.
(a) Conventional filtration treatment or direct filtration.
(1) For systems using conventional filtration or direct filtration, the turbidity level of representative samples of a system's filtered water must be less than or equal to 0.3 NTU in at least 95 percent of the measurements taken each month, measured as specified in § 141.74(a) and (c).
(2) The turbidity level of representative samples of a system's filtered water must at no time exceed 1 NTU, measured as specified in § 141.74(a) and (c).
(3) A system that uses lime softening may acidify representative samples prior to analysis using a protocol approved by the State.
(b) Filtration technologies other than conventional filtration treatment, direct filtration, slow sand filtration, or diatomaceous earth filtration. A public water system may use a filtration technology not listed in paragraph (a) of this section or in § 141.73(b) or (c) if it demonstrates to the State, using pilot plant studies or other means, that the alternative filtration technology, in combination with disinfection treatment that meets the requirements of § 141.72(b), consistently achieves 99.9 percent removal and/or inactivation of Giardia lamblia cysts and 99.99 percent removal and/or inactivation of viruses, and 99 percent removal of Cryptosporidium oocysts, and the State approves the use of the filtration technology. For each approval, the State will set turbidity performance requirements that the system must meet at least 95 percent of the time and that the system may not exceed at any time at a level that consistently achieves 99.9 percent removal and/or inactivation of Giardia lamblia cysts, 99.99 percent removal and/or inactivation of viruses, and 99 percent removal of Cryptosporidium oocysts.
[63 FR 69516, Dec. 16, 1998, as amended at 65 FR 20313, Apr. 14, 2000; 66 FR 3779, Jan. 16, 2001]

Title 40 published on 2013-07-01

The following are only the Rules published in the Federal Register after the published date of Title 40.

For a complete list of all Rules, Proposed Rules, and Notices view the Rulemaking tab.

  • 2014-02-26; vol. 79 # 38 - Wednesday, February 26, 2014
    1. 79 FR 10665 - National Primary Drinking Water Regulations: Minor Corrections to the Revisions to the Total Coliform Rule
      GPO FDSys XML | Text
      ENVIRONMENTAL PROTECTION AGENCY
      Direct final rule.
      This rule is effective on April 28, 2014 without further notice, unless EPA receives adverse comment by March 28, 2014. If EPA receives adverse comment, we will publish a timely withdrawal in the Federal Register informing the public that the rule will not take effect. The incorporation by reference of certain material listed in the rule was approved by the Director of the Federal Register as of April 15, 2013.
      40 CFR Parts 141 and 142

Title 40 published on 2013-07-01

The following are ALL rules, proposed rules, and notices (chronologically) published in the Federal Register relating to 40 CFR 141 after this date.

  • 2014-02-26; vol. 79 # 38 - Wednesday, February 26, 2014
    1. 79 FR 10665 - National Primary Drinking Water Regulations: Minor Corrections to the Revisions to the Total Coliform Rule
      GPO FDSys XML | Text
      ENVIRONMENTAL PROTECTION AGENCY
      Direct final rule.
      This rule is effective on April 28, 2014 without further notice, unless EPA receives adverse comment by March 28, 2014. If EPA receives adverse comment, we will publish a timely withdrawal in the Federal Register informing the public that the rule will not take effect. The incorporation by reference of certain material listed in the rule was approved by the Director of the Federal Register as of April 15, 2013.
      40 CFR Parts 141 and 142