40 CFR Part 265, Appendix IV to Part 265 - Tests for Significance

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There is 1 rule appearing in the Federal Register for 40 CFR 265. View below or at eCFR (GPOAccess)
View PDF at GPO Pt. 265, App. IV
Appendix IV to Part 265—Tests for Significance
As required in § 265.93(b) the owner or operator must use the Student's t-test to determine statistically significant changes in the concentration or value of an indicator parameter in periodic ground-water samples when compared to the initial background concentration or value of that indicator -parameter. The comparison must consider individually each of the wells in the monitoring system. For three of the indicator parameters (specific conductance, total organic carbon, and total organic halogen) a single-tailed Student's t-test must be used to test at the 0.01 level of significance for significant increases over background. The difference test for pH must be a two-tailed Student's t-test at the overall 0.01 level of significance.
The student's t-test involves calculation of the value of a t-statistic for each comparison of the mean (average) concentration or value (based on a minimum of four replicate measurements) of an indicator parameter with its initial background concentration or value. The calculated value of the t-statistic must then be compared to the value of the t-statistic found in a table for t-test of significance at the specified level of significance. A calculated value of t which exceeds the value of t found in the table indicates a statistically significant change in the concentration or value of the indicator parameter.
Formulae for calculation of the t-statistic and tables for t-test of significance can be found in most introductory statistics texts.

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.

  • 2014-02-07; vol. 79 # 26 - Friday, February 7, 2014
    1. 79 FR 7518 - Hazardous Waste Management System; Modification of the Hazardous Waste Manifest System; Electronic Manifests
      GPO FDSys XML | Text
      ENVIRONMENTAL PROTECTION AGENCY
      Final rule.
      This final rule is effective as a final agency action on August 6, 2014. However, the implementation and compliance date for these regulations will be delayed until such time as the e-Manifest system is shown to be ready for operation and the schedule of fees for manifest related services has been announced. EPA will publish a further document subsequent to this rule's effective date to announce the user fee schedule for manifest related activities. This document will also announce the date upon which compliance with this regulation will be required and upon which EPA will be ready to receive electronic manifests through the national e-Manifest system, in accordance with 40 CFR 3.2(a)(2).
      40 CFR Parts 260, 262, 263, 264, 265, and 271

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 265 after this date.

  • 2014-02-07; vol. 79 # 26 - Friday, February 7, 2014
    1. 79 FR 7518 - Hazardous Waste Management System; Modification of the Hazardous Waste Manifest System; Electronic Manifests
      GPO FDSys XML | Text
      ENVIRONMENTAL PROTECTION AGENCY
      Final rule.
      This final rule is effective as a final agency action on August 6, 2014. However, the implementation and compliance date for these regulations will be delayed until such time as the e-Manifest system is shown to be ready for operation and the schedule of fees for manifest related services has been announced. EPA will publish a further document subsequent to this rule's effective date to announce the user fee schedule for manifest related activities. This document will also announce the date upon which compliance with this regulation will be required and upon which EPA will be ready to receive electronic manifests through the national e-Manifest system, in accordance with 40 CFR 3.2(a)(2).
      40 CFR Parts 260, 262, 263, 264, 265, and 271