Part 141 — National Primary Drinking Water Regulations
Current through Aug 22, 2025
Authority: 42 U.S.C. 300f, 300g-1, 300g-2, 300g-3, 300g-4, 300g-5, 300g-6, 300j-4, 300j-9, and 300j-11.
Source: 40 FR 59570, Dec. 24, 1975, unless otherwise noted.
Editorial Note: Nomenclature changes to part 141 appear at 69 FR 18803, Apr. 9, 2004.
Note: For community water systems serving 75,000 or more persons, monitoring must begin 1 year following promulgation and the effective date of the MCL is 2 years following promulgation. For community water systems serving 10,000 to 75,000 persons, monitoring must begin within 3 years from the date of promulgation and the effective date of the MCL is 4 years from the date of promulgation. Effective immediately, systems that plan to make significant modifications to their treatment processes for the purpose of complying with the TTHM MCL are required to seek and obtain State approval of their treatment modification plans. This note affects §§ 141.2, 141.6, 141.12, 141.24 and 141.30. For additional information see 44 FR 68641, Nov. 29, 1979.
Sections
- § 141.1 Applicability.
- § 141.2 Definitions.
- § 141.3 Coverage.
- § 141.4 Variances and exemptions.
- § 141.5 Siting requirements.
- § 141.6 Effective dates.
- § 141.11 Maximum contaminant levels for inorganic chemicals.
- § 141.12 [Reserved]
- § 141.13 Maximum contaminant levels for turbidity.
- § 141.21 Coliform sampling.
- § 141.22 Turbidity sampling and analytical requirements.
- § 141.23 Inorganic chemical sampling and analytical requirements.
- § 141.24 Organic chemicals, sampling and analytical requirements.
- § 141.25 Analytical methods for radioactivity.
- § 141.26 Monitoring frequency and compliance requirements for radionuclides in community water systems.
- § 141.27 Alternate analytical techniques.
- § 141.28 Certified laboratories.
- § 141.29 Monitoring of consecutive public water systems.
- Appendix A to Subpart C of Part 141—Alternative Testing Methods Approved for Analyses Under the Safe Drinking Water Act
- § 141.31 Reporting requirements.
- § 141.32 [Reserved]
- § 141.33 Record maintenance.
- § 141.34 [Reserved]
- § 141.35 Reporting for unregulated contaminant monitoring results.
- § 141.40 Monitoring requirements for unregulated contaminants.
- § 141.41 Special monitoring for sodium.
- § 141.42 Special monitoring for corrosivity characteristics.
- § 141.50 Maximum contaminant level goals for organic contaminants.
- § 141.51 Maximum contaminant level goals for inorganic contaminants.
- § 141.52 Maximum contaminant level goals for microbiological contaminants.
- § 141.53 Maximum contaminant level goals for disinfection byproducts.
- § 141.54 Maximum residual disinfectant level goals for disinfectants.
- § 141.55 Maximum contaminant level goals for radionuclides.
- § 141.60 Effective dates.
- § 141.61 Maximum contaminant levels for organic contaminants.
- § 141.62 Maximum contaminant levels for inorganic contaminants.
- § 141.63 Maximum contaminant levels (MCLs) for microbiological contaminants.
- § 141.64 Maximum contaminant levels for disinfection byproducts.
- § 141.65 Maximum residual disinfectant levels.
- § 141.66 Maximum contaminant levels for radionuclides.
- § 141.70 General requirements.
- § 141.71 Criteria for avoiding filtration.
- § 141.72 Disinfection.
- § 141.73 Filtration.
- § 141.74 Analytical and monitoring requirements.
- § 141.75 Reporting and recordkeeping requirements.
- § 141.76 Recycle provisions.
- § 141.80 General requirements and action level.
- § 141.81 Applicability of corrosion control treatment steps to small, medium, and large water systems.
- § 141.82 Description of corrosion control treatment requirements.
- § 141.83 Source water treatment requirements.
- § 141.84 Service line inventory and replacement requirements.
- § 141.85 Public education and supplemental monitoring and mitigation requirements.
- § 141.86 Monitoring requirements for lead and copper in tap water.
- § 141.87 Monitoring requirements for water quality parameters.
- § 141.88 Monitoring requirements for lead and copper in source water.
- § 141.89 Analytical methods.
- § 141.90 Reporting requirements.
- § 141.91 Recordkeeping requirements.
- § 141.92 Monitoring for lead in schools and child care facilities.
- § 141.93 Small water system compliance flexibility.
- § 141.100 Criteria and procedures for public water systems using point-of-entry devices.
- § 141.101 Use of bottled water.
- § 141.110 General requirements.
- § 141.111 Treatment techniques for acrylamide and epichlorohydrin.
- § 141.130 General requirements.
- § 141.131 Analytical requirements.
- § 141.132 Monitoring requirements.
- § 141.133 Compliance requirements.
- § 141.134 Reporting and recordkeeping requirements.
- § 141.135 Treatment technique for control of disinfection byproduct (DBP) precursors.
- § 141.151 Purpose and applicability of this subpart.
- § 141.152 Compliance dates.
- § 141.153 Content of the reports.
- § 141.154 Required additional health information.
- § 141.155 Report delivery, reporting, and recordkeeping.
- § 141.156 Summary of report contents.
- § 141.170 General requirements.
- § 141.171 Criteria for avoiding filtration.
- § 141.172 Disinfection profiling and benchmarking.
- § 141.173 Filtration.
- § 141.174 Filtration sampling requirements.
- § 141.175 Reporting and recordkeeping requirements.
- § 141.201 General public notification requirements.
- § 141.202 Tier 1 Public Notice—Form, manner, and frequency of notice.
- § 141.203 Tier 2 Public Notice—Form, manner, and frequency of notice.
- § 141.204 Tier 3 Public Notice—Form, manner, and frequency of notice.
- § 141.205 Content of the public notice.
- § 141.206 Notice to new billing units or new customers.
- § 141.207 Special notice of the availability of unregulated contaminant monitoring results.
- § 141.208 Special notice for exceedance of the SMCL for fluoride.
- § 141.209 Special notice for nitrate exceedances above MCL by non-community water systems (NCWS), where granted permission by the primacy agency under § 141.11(d).
- § 141.210 Notice by primacy agency on behalf of the public water system.
- § 141.211 Special notice for repeated failure to conduct monitoring of the source water for Cryptosporidium and for failure to determine bin classification or mean Cryptosporidium level.
- Appendix B to Subpart Q of Part 141—Standard Health Effects Language for Public Notification
- Appendix C to Subpart Q of Part 141—List of Acronyms Used in Public Notification Regulation
- § 141.400 General requirements and applicability.
- § 141.401 Sanitary surveys for ground water systems.
- § 141.402 Ground water source microbial monitoring and analytical methods.
- § 141.403 Treatment technique requirements for ground water systems.
- § 141.404 Treatment technique violations for ground water systems.
- § 141.405 Reporting and recordkeeping for ground water systems.
- § 141.500 General requirements.
- § 141.501 Who is subject to the requirements of subpart T?
- § 141.502 When must my system comply with these requirements?
- § 141.503 What does subpart T require?
- § 141.510 Is my system subject to the new finished water reservoir requirements?
- § 141.511 What is required of new finished water reservoirs?
- § 141.520 Is my system subject to the updated watershed control requirements?
- § 141.521 What updated watershed control requirements must my unfiltered system implement to continue to avoid filtration?
- § 141.522 How does the State determine whether my system's watershed control requirements are adequate?
- § 141.530 What is a disinfection profile and who must develop one?
- § 141.531 What criteria must a State use to determine that a profile is unnecessary?
- § 141.532 How does my system develop a disinfection profile and when must it begin?
- § 141.533 What data must my system collect to calculate a disinfection profile?
- § 141.534 How does my system use this data to calculate an inactivation ratio?
- § 141.535 What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?
- § 141.536 My system has developed an inactivation ratio; what must we do now?
- § 141.540 Who has to develop a disinfection benchmark?
- § 141.541 What are significant changes to disinfection practice?
- § 141.542 What must my system do if we are considering a significant change to disinfection practices?
- § 141.543 How is the disinfection benchmark calculated?
- § 141.544 What if my system uses chloramines, ozone, or chlorine dioxide for primary disinfection?
- § 141.550 Is my system required to meet subpart T combined filter effluent turbidity limits?
- § 141.551 What strengthened combined filter effluent turbidity limits must my system meet?
- § 141.552 My system consists of “alternative filtration” and is required to conduct a demonstration—what is required of my system and how does the State establish my turbidity limits?
- § 141.553 My system practices lime softening—is there any special provision regarding my combined filter effluent?
- § 141.560 Is my system subject to individual filter turbidity requirements?
- § 141.561 What happens if my system's turbidity monitoring equipment fails?
- § 141.562 My system only has two or fewer filters—is there any special provision regarding individual filter turbidity monitoring?
- § 141.563 What follow-up action is my system required to take based on continuous turbidity monitoring?
- § 141.564 My system practices lime softening—is there any special provision regarding my individual filter turbidity monitoring?
- § 141.570 What does subpart T require that my system report to the State?
- § 141.571 What records does subpart T require my system to keep?
- § 141.600 General requirements.
- § 141.601 Standard monitoring.
- § 141.602 System specific studies.
- § 141.603 40/30 certification.
- § 141.604 Very small system waivers.
- § 141.605 Subpart V compliance monitoring location recommendations.
- § 141.620 General requirements.
- § 141.621 Routine monitoring.
- § 141.622 Subpart V monitoring plan.
- § 141.623 Reduced monitoring.
- § 141.624 Additional requirements for consecutive systems.
- § 141.625 Conditions requiring increased monitoring.
- § 141.626 Operational evaluation levels.
- § 141.627 Requirements for remaining on reduced TTHM and HAA5 monitoring based on subpart L results.
- § 141.628 Requirements for remaining on increased TTHM and HAA5 monitoring based on subpart L results.
- § 141.629 Reporting and recordkeeping requirements.
- § 141.700 General requirements.
- § 141.701 Source water monitoring.
- § 141.702 Sampling schedules.
- § 141.703 Sampling locations.
- § 141.704 Analytical methods.
- § 141.705 Approved laboratories.
- § 141.706 Reporting source water monitoring results.
- § 141.707 Grandfathering previously collected data.
- § 141.708 Requirements when making a significant change in disinfection practice.
- § 141.709 Developing the disinfection profile and benchmark.
- § 141.710 Bin classification for filtered systems.
- § 141.711 Filtered system additional Cryptosporidium treatment requirements.
- § 141.712 Unfiltered system Cryptosporidium treatment requirements.
- § 141.713 Schedule for compliance with Cryptosporidium treatment requirements.
- § 141.714 Requirements for uncovered finished water storage facilities.
- § 141.715 Microbial toolbox options for meeting Cryptosporidium treatment requirements.
- § 141.716 Source toolbox components.
- § 141.717 Pre-filtration treatment toolbox components.
- § 141.718 Treatment performance toolbox components.
- § 141.719 Additional filtration toolbox components.
- § 141.720 Inactivation toolbox components.
- § 141.721 Reporting requirements.
- § 141.722 Recordkeeping requirements.
- § 141.723 Requirements to respond to significant deficiencies identified in sanitary surveys performed by EPA.
- § 141.800 Applicability and compliance date.
- § 141.801 Definitions.
- § 141.802 Coliform sampling plan.
- § 141.803 Coliform sampling.
- § 141.804 Aircraft water system operations and maintenance plan.
- § 141.805 Notification to passengers and crew.
- § 141.806 Reporting requirements.
- § 141.807 Recordkeeping requirements.
- § 141.808 Audits and inspections.
- § 141.809 Supplemental treatment.
- § 141.810 Violations.
- § 141.851 General.
- § 141.852 Analytical methods and laboratory certification.
- § 141.853 General monitoring requirements for all public water systems.
- § 141.854 Routine monitoring requirements for non-community water systems serving 1,000 or fewer people using only ground water.
- § 141.855 Routine monitoring requirements for community water systems serving 1,000 or fewer people using only ground water.
- § 141.856 Routine monitoring requirements for subpart H public water systems serving 1,000 or fewer people.
- § 141.857 Routine monitoring requirements for public water systems serving more than 1,000 people.
- § 141.858 Repeat monitoring and E. coli requirements.
- § 141.859 Coliform treatment technique triggers and assessment requirements for protection against potential fecal contamination.
- § 141.860 Violations.
- § 141.861 Reporting and recordkeeping.
- § 141.900 General requirements.
- § 141.901 Analytical requirements.
- § 141.902 Monitoring requirements.
- § 141.903 Compliance requirements.
- § 141.904 Reporting and recordkeeping requirements.
- § 141.905 Violations.