40 CFR 141.717 - Pre-filtration treatment toolbox components.

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There is 1 rule appearing in the Federal Register for 40 CFR 141. View below or at eCFR (GPOAccess)
§ 141.717 Pre-filtration treatment toolbox components.
(a) Presedimentation. Systems receive 0.5-log Cryptosporidium treatment credit for a presedimentation basin during any month the process meets the criteria in this paragraph.
(1) The presedimentation basin must be in continuous operation and must treat the entire plant flow taken from a surface water or GWUDI source.
(2) The system must continuously add a coagulant to the presedimentation basin.
(3) The presedimentation basin must achieve the performance criteria in paragraph (3)(i) or (ii) of this section.
(i) Demonstrates at least 0.5-log mean reduction of influent turbidity. This reduction must be determined using daily turbidity measurements in the presedimentation process influent and effluent and must be calculated as follows: log10(monthly mean of daily influent turbidity)−log10(monthly mean of daily effluent turbidity).
(ii) Complies with State-approved performance criteria that demonstrate at least 0.5-log mean removal of micron-sized particulate material through the presedimentation process.
(b) Two-stage lime softening. Systems receive an additional 0.5-log Cryptosporidium treatment credit for a two-stage lime softening plant if chemical addition and hardness precipitation occur in two separate and sequential softening stages prior to filtration. Both softening stages must treat the entire plant flow taken from a surface water or GWUDI source.
(c) Bank filtration. Systems receive Cryptosporidium treatment credit for bank filtration that serves as pretreatment to a filtration plant by meeting the criteria in this paragraph. Systems using bank filtration when they begin source water monitoring under § 141.701(a) must collect samples as described in § 141.703(d) and are not eligible for this credit.
(1) Wells with a ground water flow path of at least 25 feet receive 0.5-log treatment credit; wells with a ground water flow path of at least 50 feet receive 1.0-log treatment credit. The ground water flow path must be determined as specified in paragraph (c)(4) of this section.
(2) Only wells in granular aquifers are eligible for treatment credit. Granular aquifers are those comprised of sand, clay, silt, rock fragments, pebbles or larger particles, and minor cement. A system must characterize the aquifer at the well site to determine aquifer properties. Systems must extract a core from the aquifer and demonstrate that in at least 90 percent of the core length, grains less than 1.0 mm in diameter constitute at least 10 percent of the core material.
(3) Only horizontal and vertical wells are eligible for treatment credit.
(4) For vertical wells, the ground water flow path is the measured distance from the edge of the surface water body under high flow conditions (determined by the 100 year floodplain elevation boundary or by the floodway, as defined in Federal Emergency Management Agency flood hazard maps) to the well screen. For horizontal wells, the ground water flow path is the measured distance from the bed of the river under normal flow conditions to the closest horizontal well lateral screen.
(5) Systems must monitor each wellhead for turbidity at least once every four hours while the bank filtration process is in operation. If monthly average turbidity levels, based on daily maximum values in the well, exceed 1 NTU, the system must report this result to the State and conduct an assessment within 30 days to determine the cause of the high turbidity levels in the well. If the State determines that microbial removal has been compromised, the State may revoke treatment credit until the system implements corrective actions approved by the State to remediate the problem.
(6) Springs and infiltration galleries are not eligible for treatment credit under this section, but are eligible for credit under § 141.718(c).
(7) Bank filtration demonstration of performance. The State may approve Cryptosporidium treatment credit for bank filtration based on a demonstration of performance study that meets the criteria in this paragraph. This treatment credit may be greater than 1.0-log and may be awarded to bank filtration that does not meet the criteria in paragraphs (c)(1)-(5) of this section.
(i) The study must follow a State-approved protocol and must involve the collection of data on the removal of Cryptosporidium or a surrogate for Cryptosporidium and related hydrogeologic and water quality parameters during the full range of operating conditions.
(ii) The study must include sampling both from the production well(s) and from monitoring wells that are screened and located along the shortest flow path between the surface water source and the production well(s).

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