Regulations last checked for updates: Nov 23, 2024

Title 40 - Protection of Environment last revised: Nov 21, 2024
§ 141.151 - Purpose and applicability of this subpart.

(a) This subpart establishes the minimum requirements for the content of reports that community water systems must deliver to their customers. These reports must contain information on the quality of the water delivered by the systems and characterize the risks (if any) from exposure to contaminants detected in the drinking water in an accurate and understandable manner. This subpart also includes requirements for systems serving more than 100,000 persons to develop and annually update a plan for providing assistance to consumers with limited English proficiency.

(b) Notwithstanding the provisions of § 141.3, this subpart applies only to community water systems.

(c) For the purpose of this subpart, customers are defined as billing units or service connections to which water is delivered by a community water system. For the purposes of this subpart, consumers are defined as people served by the water system, including customers, and people that do not receive a bill.

(d) For the purpose of this subpart, detected means: at or above the levels prescribed by § 141.23(a)(4) for inorganic contaminants, at or above the levels prescribed by § 141.24(f)(7) for the contaminants listed in § 141.61(a), at or above the levels prescribed by § 141.24(h)(18) for the contaminants listed in § 141.61(c) (except PFAS), at or above the levels prescribed by § 141.131(b)(2)(iv) for the contaminants or contaminant groups listed in § 141.64, at or above the levels prescribed by § 141.25(c) for radioactive contaminants, and at or above the levels prescribed in § 141.902(a)(5) for PFAS listed in § 141.61(c).

(e) A State that has primary enforcement responsibility may adopt by rule, after notice and comment, alternative requirements for the form and content of the reports. The alternative requirements must provide the same type and amount of information as required by §§ 141.153 and 141.154, and must be designed to achieve an equivalent level of public information and education as would be achieved under this subpart.

(f) For purpose of this subpart, the term “primacy agency” refers to the State or Tribal government entity that has jurisdiction over, and primary enforcement responsibility for, public water systems, even if that government does not have interim or final primary enforcement responsibility for this part. Where the State or tribe does not have primary enforcement responsibility for public water systems, the term “primacy agency” refers to the appropriate EPA regional office.

[63 FR 44526, Aug. 19, 1998, as amended at 71 FR 483, Jan. 4, 2006; 89 FR 46008, May 24, 2024; 89 FR 32746, Apr. 26, 2024]
§ 141.152 - Compliance dates.
Link to an amendment published at 89 FR 86662, Oct. 30, 2024.

(a) Between June 24, 2024, and December 31, 2026, community water systems must comply with §§ 141.151 through 141.155, as codified in 40 CFR part 141, subpart O, on July 1, 2023. Beginning January 1, 2027, community water systems must comply with §§ 141.151 through 141.156.

(b) Each existing community water system must deliver reports according to § 141.155 by July 1 each year. Each report delivered by July 1 must contain data collected during the previous calendar year, or the most recent calendar year before the previous calendar year.

(c) A new community water system must deliver its first report by July 1 of the year after its first full calendar year in operation.

(d) A community water system that sells water to another community water system must deliver the applicable information required in § 141.153 to the buyer system:

(1) By April 1, 2027, and annually thereafter; or

(2) On a date mutually agreed upon by the seller and the purchaser, and specifically included in a contract between the parties; and

(3) A community water system that sells water to another community water system that is required to provide reports biannually according to § 141.155(i) must provide the applicable information required in § 141.155(j) by October 1, 2027, to the buyer system, and annually thereafter, or a date mutually agreed upon by the seller and the purchaser, included in a contract between the parties.

[63 FR 44526, Aug. 19, 1998, as amended at 89 FR 46008, May 24, 2024]
§ 141.153 - Content of the reports.
Link to an amendment published at 89 FR 86662, Oct. 30, 2024.

(a) Each community water system must provide to its customers a report(s) that contains the information specified in this section, § 141.154, and include a summary as specified in § 141.156.

(b) Information on the source of the water delivered:

(1) Each report must identify the source(s) of the water delivered by the community water system by providing information on:

(i) The type of the water: e.g., surface water, ground water; and

(ii) The commonly used name (if any) and location of the body (or bodies) of water.

(2) If a source water assessment has been completed, the report must notify consumers of the availability of this information, the year it was completed or most recently updated, and the means to obtain it. In addition, systems are encouraged to highlight in the report significant sources of contamination in the source water area if they have readily available information. Where a system has received a source water assessment from the primacy agency, the report must include a brief summary of the system's susceptibility to potential sources of contamination, using language provided by the primacy agency or written by the operator.

(c) Definitions. (1) Each report must include the following definitions:

(i) Maximum Contaminant Level Goal or MCLG: The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety.

(ii) Maximum Contaminant Level or MCL: The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to the MCLGs as feasible using the best available treatment technology.

(iii) Contaminant: Any physical, chemical, biological, or radiological substance or matter in water.

(2) A report for a community water system operating under a variance or an exemption issued under § 1415 or 1416 of SDWA must include the following definition: Variances and Exemptions: State or EPA permission not to meet an MCL or a treatment technique under certain conditions.

(3) A report that contains data on contaminants that EPA regulates using any of the following terms must include the applicable definitions:

(i) Treatment Technique: A required process intended to reduce the level of a contaminant in drinking water.

(ii) Action Level: The concentration of a contaminant which, if exceeded, triggers treatment or other requirements which a water system must follow.

(iii) Maximum residual disinfectant level goal or MRDLG: The level of a drinking water disinfectant below which there is no known or expected risk to health. MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contaminants.

(iv) Maximum residual disinfectant level or MRDL: The highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants.

(v) Hazard Index or HI. The Hazard Index is an approach that determines the health concerns associated with mixtures of certain PFAS in finished drinking water. Low levels of multiple PFAS that individually would not likely result in adverse health effects may pose health concerns when combined in a mixture. The Hazard Index MCL represents the maximum level for mixtures of PFHxS, PFNA, HFPO-DA, and/or PFBS allowed in water delivered by a public water system. A Hazard Index greater than 1 requires a system to take action.

(4) A report that contains information regarding a Level 1 or Level 2 Assessment required under Subpart Y of this part must include the applicable definitions:

(i) Level 1 Assessment: A Level 1 assessment is a study of the water system to identify potential problems and determine (if possible) why total coliform bacteria have been found in our water system.

(ii) Level 2 Assessment: A Level 2 assessment is a very detailed study of the water system to identify potential problems and determine (if possible) why an E. coli MCL violation has occurred and/or why total coliform bacteria have been found in our water system on multiple occasions.

(5) Systems must use the following definitions for the terms listed below if the terms are used in the report unless the system obtains written approval from the state to use an alternate definition:

(i) Pesticide: Generally, any substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest.

(ii) Herbicide: Any chemical(s) used to control undesirable vegetation.

(d) Information on detected contaminants. (1) This sub-section specifies the requirements for information to be included in each report for contaminants subject to mandatory monitoring (except Cryptosporidium). It applies to:

(i) Contaminants subject to a MCL, action level, maximum residual disinfectant level, or treatment technique (regulated contaminants); and

(ii) Contaminants for which monitoring is required by § 141.40 (unregulated contaminants).

(2) The data relating to these contaminants must be presented in the reports in a manner that is clear and understandable for consumers. For example, the data may be displayed in one table or in several adjacent tables. Any additional monitoring results which a community water system chooses to include in its report must be displayed separately.

(3) The data must be derived from data collected to comply with EPA and State monitoring and analytical requirements during the previous calendar year, or the most recent calendar year before the previous calendar year except that:

(i) Where a system is allowed to monitor for regulated contaminants less often than once a year, the contaminant data section must include the date and results of the most recent sampling and the report must include a brief statement indicating that the data presented in the report are from the most recent testing done in accordance with the regulations. No data older than 5 years need be included.

(ii) [Reserved]

(4) For each detected regulated contaminant (listed in appendix A to this subpart), the contaminant data section(s) must contain:

(i) The MCL for that contaminant expressed as a number equal to or greater than 1.0 (as provided in appendix A to this subpart);

(ii) The MCLG for that contaminant expressed in the same units as the MCL;

(iii) If there is no MCL for a detected contaminant, the contaminant data section(s) must indicate that there is a treatment technique, or specify the action level, applicable to that contaminant, and the report must include the definitions for treatment technique and/or action level, as appropriate, specified in paragraph (c)(3) of this section;

(iv) For contaminants subject to an MCL, except turbidity and E. coli, the contaminant data section(s) must contain the highest contaminant level used to determine compliance with an NPDWR and the range of detected levels, as follows:

(A) When compliance with the MCL is determined annually or less frequently: The highest detected level at any sampling point and the range of detected levels expressed in the same units as the MCL.

(B) When compliance with the MCL is determined by calculating a running annual average of all samples taken at a monitoring location: the highest average of any of the monitoring locations and the range of individual sample results for all monitoring locations expressed in the same units as the MCL. For the MCLs for TTHM and HAA5 in § 141.64(b)(2), systems must include the highest locational running annual average for TTHM and HAA5 and the range of individual sample results for all monitoring locations expressed in the same units as the MCL. If more than one location exceeds the TTHM or HAA5 MCL, the system must include the locational running annual averages for all locations that exceed the MCL.

Note to paragraph (d)(4)(iv):

When rounding of results to determine compliance with the MCL is allowed by the regulations, rounding should be done prior to multiplying the results by the factor listed in appendix A of this subpart.

(v) For turbidity.

(A) When it is reported pursuant to § 141.13: The highest average monthly value.

(B) When it is reported pursuant to the requirements of § 141.71: the highest monthly value. The report should include an explanation of the reasons for measuring turbidity.

(C) When it is reported pursuant to § 141.73 or § 141.173 or § 141.551: the highest single measurement and the lowest monthly percentage of samples meeting the turbidity limits specified in § 141.73 or § 141.173, or § 141.551 for the filtration technology being used. The report should include an explanation of the reasons for measuring turbidity;

(vi) For lead and copper: the 90th percentile concentration of the most recent round(s) of sampling, the number of sampling sites exceeding the action level, and the range of tap sampling results;

(vii)-(viii) [Reserved]

(ix) The likely source(s) of detected contaminants to the best of the operator's knowledge. Specific information regarding contaminants may be available in sanitary surveys and source water assessments, and should be used when available to the operator. If the operator lacks specific information on the likely source, the report must include one or more of the typical sources for that contaminant listed in appendix A to this subpart that is most applicable to the system; and

(x) For E. coli analytical results under subpart Y: The total number of E. coli positive samples;

(5) If a community water system distributes water to its customers from multiple hydraulically independent distribution systems that are fed by different raw water sources, the contaminant data section(s) should differentiate contaminant data for each service area and the report should identify each separate distribution system. For example, if displayed in a table, it should contain a separate column for each service area. Alternatively, systems could produce separate reports tailored to include data for each service area.

(6) The detected contaminant data section(s) must clearly identify any data indicating violations of MCLs, MRDLs, or treatment techniques, and the report must contain a clear and readily understandable explanation of the violation including: the length of the violation, the potential adverse health effects, and actions taken by the system to address the violation. To describe the potential health effects, the system must use the relevant language of appendix A to this subpart.

(7) For detected unregulated contaminants for which monitoring is required, the reports must present the average and range at which the contaminant was detected. The report must include a brief explanation of the reasons for monitoring for unregulated contaminants such as:

(i) Unregulated contaminant monitoring helps EPA to determine where certain contaminants occur and whether the Agency should consider regulating those contaminants in the future.

(ii) May use an alternative educational statement in the CCR if approved by the Primacy Agency.

(8) For systems that exceeded the lead action level in § 141.80(c), the detected contaminant data section must clearly identify the exceedance if any corrective action has been required by the Administrator or the State during the monitoring period covered by the report. The report must include a clear and readily understandable explanation of the exceedance, the steps consumers can take to reduce their exposure to lead in drinking water, and a description of any corrective actions the system has or will take to address the exceedance.

(e) Information on Cryptosporidium, radon, and other contaminants:

(1) If the system has performed any monitoring for Cryptosporidium which indicates that Cryptosporidium may be present in the source water or the finished water, the report must include:

(i) A summary of the results of the monitoring; and

(ii) An explanation of the significance of the results.

(2) If the system has performed any monitoring for radon which indicates that radon may be present in the finished water, the report must include:

(i) The results of the monitoring; and

(ii) An explanation of the significance of the results.

(3) If the system has performed additional monitoring which indicates the presence of other contaminants in the finished water, EPA strongly encourages systems to report any results which may indicate a health concern. To determine if results may indicate a health concern, EPA recommends that systems find out if EPA has proposed an NPDWR or issued a health advisory for that contaminant by contacting the Agency by calling the Safe Drinking Water Hotline (800-426-4791) or an alternative method identified on the website epa.gov/safewater. EPA considers detects above a proposed MCL or health advisory level to indicate possible health concerns. For such contaminants, EPA recommends that the report include:

(i) The results of the monitoring; and

(ii) An explanation of the significance of the results noting the existence of a health advisory or a proposed regulation.

(f) Compliance with NPDWR. In addition to the requirements of paragraph (d)(6) of this section, the report must note any violation that occurred during the period covered by the report of a requirement listed below, and include a clear and readily understandable explanation of the violation, any potential adverse health effects, and the steps the system has taken to correct the violation.

(1) Monitoring and reporting of compliance data;

(2) Filtration and disinfection prescribed by subpart H of this part. For systems which have failed to install adequate filtration or disinfection equipment or processes, or have had a failure of such equipment or processes which constitutes a violation, the report must include the following language as part of the explanation of potential adverse health effects: Inadequately treated water may contain disease-causing organisms. These organisms include bacteria, viruses, and parasites which can cause symptoms such as nausea, cramps, diarrhea, and associated headaches.

(3) Lead and copper control requirements prescribed by subpart I of this part. For systems that fail to take one or more actions prescribed by §§ 141.80(d), 141.81, 141.82, 141.83, 141.84, or 141.93, the report must include the applicable language of appendix A to this subpart for lead, copper, or both.

(4) Treatment techniques for Acrylamide and Epichlorohydrin prescribed by subpart K of this part. For systems that violate the requirements of subpart K of this part, the report must include the relevant language from appendix A to this subpart.

(5) Recordkeeping of compliance data.

(6) Special monitoring requirements prescribed by §§ 141.40 and 141.41; and

(7) Violation of the terms of a variance, an exemption, or an administrative or judicial order.

(g) Variances and Exemptions. If a system is operating under the terms of a variance or an exemption issued under § 1415 or 1416 of SDWA, the report must contain:

(1) An explanation of the reasons for the variance or exemption;

(2) The date on which the variance or exemption was issued;

(3) A brief status report on the steps the system is taking to install treatment, find alternative sources of water, or otherwise comply with the terms and schedules of the variance or exemption; and

(4) A notice of any opportunity for public input in the review, or renewal, of the variance or exemption.

(h) Additional information:

(1) The report must contain a brief explanation regarding contaminants which may reasonably be expected to be found in drinking water including bottled water. This explanation may include the language of paragraphs (h)(1)(i) through (iii) of this section or systems may use their own comparable language. The report also must include the language of paragraph (h)(1)(iv) of this section.

(i) Both tap water and bottled water come from rivers, lakes, streams, ponds, reservoirs, springs, and wells. As water travels over the surface of the land or through the ground, it dissolves naturally occurring minerals and, in some cases, radioactive material. The water can also pick up and transport substances resulting from the presence of animals or from human activity. These substances are also called contaminants.

(ii) Contaminants are any physical, chemical, biological, or radiological substance or matter in water. Contaminants that may be present in source water include:

(A) Microbial contaminants, such as viruses and bacteria, which may come from sewage treatment plants, septic systems, agricultural livestock operations, and wildlife.

(B) Inorganic contaminants, such as salts and metals, which can occur naturally in the soil or groundwater or may result from urban stormwater runoff, industrial or domestic wastewater discharges, oil and gas production, mining, or farming.

(C) Pesticides and herbicides, which may come from a variety of sources such as agriculture, urban stormwater runoff, and residential uses.

(D) Organic chemical contaminants, including synthetic and volatile organic chemicals, which are by-products of industrial processes and petroleum production, and can also come from gas stations, urban stormwater runoff, and septic systems.

(E) Radioactive contaminants, which can occur naturally or be the result of oil and gas production and mining activities.

(iii) To protect public health, the Environmental Protection Agency prescribes regulations which limit the amount of certain contaminants in tap water provided by public water systems. The Food and Drug Administration regulations establish limits for contaminants in bottled water which must provide the same protection for public health.

(iv) Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily mean that water poses a health risk. More information about contaminants and potential health effects can be obtained by contacting the Environmental Protection Agency by calling the Safe Drinking Water Hotline (800-426-4791) or visiting the website epa.gov/safewater.

(2) The report must include the telephone number of the owner, operator, or designee of the community water system as a source of additional information concerning the report. If a system uses a website or social media to share additional information, EPA recommends including information about how to access such media platforms in the report.

(3) In communities with a large proportion of consumers with limited English proficiency, as determined by the Primacy Agency, the report must contain information in the appropriate language(s) regarding the importance of the report and either contain information where such consumers may obtain a translated copy of the report, or assistance in the appropriate language(s), or the report must be in the appropriate language(s).

(4) The report must include information (e.g., time and place of regularly scheduled board meetings) about opportunities for public participation in decisions that may affect the quality of the water.

(5) The systems may include such additional information as they deem necessary for public education consistent with, and not detracting from, the purpose of the report.

(6) Systems required to comply with subpart S of this part.

(i) Any ground water system that receives notice from the State of a significant deficiency or notice from a laboratory of a fecal indicator-positive ground water source sample that is not invalidated by the State under § 141.402(d) must inform its customers of any significant deficiency that is uncorrected at the time of the next reporting period or of any fecal indicator-positive ground water source sample in the next report or 6-month update according to § 141.155. The system must continue to inform the public annually until the State determines that particular significant deficiency is corrected or the fecal contamination in the ground water source is addressed under § 141.403(a). Each report must include the following elements:

(A) The nature of the particular significant deficiency or the source of the fecal contamination (if the source is known) and the date the significant deficiency was identified by the State or the dates of the fecal indicator-positive ground water source samples;

(B) If the fecal contamination in the ground water source has been addressed under § 141.403(a) and the date of such action;

(C) For each significant deficiency or fecal contamination in the ground water source that has not been addressed under § 141.403(a), the State-approved plan and schedule for correction, including interim measures, progress to date, and any interim measures completed; and

(D) If the system receives notice of a fecal indicator-positive ground water source sample that is not invalidated by the State under § 141.402(d), the potential health effects using the health effects language of appendix A to this subpart.

(ii) If directed by the State, a system with significant deficiencies that have been corrected before the next report is issued must inform its customers of the significant deficiency, how the deficiency was corrected, and the date of correction under paragraph (h)(6)(i) of this section.

(7) Systems required to comply with subpart Y of this part.

(i) Any system required to comply with the Level 1 assessment requirement or a Level 2 assessment requirement that is not due to an E. coli MCL violation must include in the report the text found in paragraphs (h)(7)(i)(A) through (C) of this section as appropriate, filling in the blanks accordingly and the text found in paragraphs (h)(7)(i)(D)(1) and (2) of this section if appropriate. Systems may use an alternative statement with equivalent information for paragraphs (h)(7)(i)(B) and (C) of this section if approved by the primacy agency.

(A) Coliforms are bacteria that occur naturally in the environment and are used as an indicator that other, potentially harmful, waterborne organisms may be present or that a potential pathway exists through which contamination may enter the drinking water distribution system. We found coliforms indicating the need to look for potential problems in water treatment or distribution. When this occurs, we are required to conduct assessment(s) to identify problems and to correct any problems that were found during these assessments.

(B) Because we found coliforms during sampling, we were required to conduct [INSERT NUMBER OF LEVEL 1 ASSESSMENTS] assessment(s) of the system, also known as a Level 1 assessment, to identify possible sources of contamination. [INSERT NUMBER OF LEVEL 1 ASSESSMENTS] Level 1 assessment(s) were completed. In addition, we were required to take [INSERT NUMBER OF CORRECTIVE ACTIONS] corrective actions and we completed [INSERT NUMBER OF CORRECTIVE ACTIONS] of these actions.

(C) Because we found coliforms during sampling, we were required to conduct [INSERT NUMBER OF LEVEL 2 ASSESSMENTS] detailed assessments, also known as a Level 2 assessment, to identify possible sources of contamination. [INSERT NUMBER OF LEVEL 2 ASSESSMENTS] Level 2 assessments were completed. In addition, we were required to take [INSERT NUMBER OF CORRECTIVE ACTIONS] corrective actions and we completed [INSERT NUMBER OF CORRECTIVE ACTIONS] of these actions.

(D) Any system that has failed to complete all the required assessments or correct all identified sanitary defects, is in violation of the treatment technique requirement and must also include one or both of the following statements, as appropriate:

(1) During the past year we failed to conduct all the required assessment(s).

(2) During the past year we failed to correct all identified defects that were found during the assessment.

(ii) Any system required to conduct a Level 2 assessment due to an E. coli MCL violation must include in the report the text found in paragraphs (h)(7)(ii)(A) and (B) of this section, and health effects language in appendix A to this subpart, filling in the blanks accordingly and the text found in paragraphs (h)(7)(ii)(C)(1) and (2) of this section, if appropriate. Systems may use an alternative statement with equivalent information for paragraphs (h)(7)(ii)(A) through (C) of this section, if approved by the primacy agency.

(A) We found E. coli bacteria, indicating the need to look for potential problems in water treatment or distribution. When this occurs, we are required to conduct assessment(s), also known as a Level 2 assessment, to identify problems and to correct any problems that were found during these assessments.

(B) We were required to complete a detailed assessment of our water system, also known as a Level 2 assessment, because we found E. coli in our water system. In addition, we were required to take [INSERT NUMBER OF CORRECTIVE ACTIONS] corrective actions and we completed [INSERT NUMBER OF CORRECTIVE ACTIONS] of these actions.

(C) Any system that has failed to complete the required assessment or correct all identified sanitary defects, is in violation of the treatment technique requirement and must also include one or both of the following statements, as appropriate:

(1) We failed to conduct the required assessment.

(2) We failed to correct all defects that were identified during the assessment that we conducted.

(iii) If a system detects E. coli and has violated the E. coli MCL, in addition to completing the table as required in paragraph (d)(4) of this section, the system must include one or more of the following statements to describe any noncompliance, as applicable:

(A) We had an E. coli-positive repeat sample following a total coliform-positive routine sample.

(B) We had a total coliform-positive repeat sample following an E. coli-positive routine sample.

(C) We failed to take all required repeat samples following an E. coli-positive routine sample.

(D) We failed to test for E. coli when any repeat sample tested positive for total coliform.

(iv) If a system detects E. coli and has not violated the E. coli MCL, in addition to completing the table as required in paragraph (d)(4) of this section, the system may include a statement that explains that although they have detected E. coli, they are not in violation of the E. coli MCL.

(8) Systems required to comply with subpart I of this part.

(i) The report must notify consumers that complete lead tap sampling data are available for review and must include information on how to access the data.

(ii) The report must include a statement that a service line inventory (including inventories consisting only of a statement that there are no lead, galvanized requiring replacement, or lead status unknown service lines) has been prepared and include instructions to access the publicly available service line inventory. If the service line inventory is available online, the report must include the direct link to the inventory.

(iii) The report must contain a plainly worded explanation of the corrosion control efforts the system is taking in accordance with subpart I of this part. Corrosion control efforts consist of treatment (e.g., pH adjustment, alkalinity adjustment, or corrosion inhibitor addition) and other efforts contributing to the control of the corrosivity of water, e.g., monitoring to assess the corrosivity of water. The system may use one of the following templates or use their own explanation that includes equivalent information.

(A) For systems with state or EPA-designated Optimal Corrosion Control Treatment:

(1) Corrosion of pipes, plumbing fittings and fixtures may cause lead and copper to enter drinking water. To assess corrosion of lead and copper, [name of system] conducts tap sampling for lead and copper at selected sites [insert frequency at which system conducts tap sampling]. [Name of system] treats water using [identify treatment method] to control corrosion, which was designated as the optimal corrosion control treatment by [the state or EPA, as applicable]. To ensure the treatment is operating effectively, [name of system] monitors water quality parameters set by the [state or EPA, as applicable] [insert frequency at which system conducts water quality parameter monitoring].

(2) If applicable add: [Name of system] is currently conducting a study of corrosion control to determine if any changes to treatment methods are needed to minimize the corrosivity of the water.

(B) For systems without state or EPA designated Optimal Corrosion Control Treatment:

(1) Corrosion of pipes, plumbing fittings and fixtures may cause metals, including lead and copper, to enter drinking water. To assess corrosion of lead and copper, [name of system] conducts tap sampling for lead and copper at selected sites [insert frequency at which system conducts tap sampling].

(2) If applicable, add: [Name of system] treats water using [identify treatment method] to control corrosion.

(3) If applicable add: [Name of system] is currently conducting a study of corrosion control to determine if any changes to treatment methods are needed to minimize the corrosivity of the water.

[63 FR 44526, Aug. 19, 1998, as amended at 63 FR 69516, Dec. 16, 1998; 64 FR 34733, June 29, 1999; 65 FR 26022, May 4, 2000; 67 FR 1836, Jan. 14, 2002; 71 FR 483, Jan. 4, 2006; 71 FR 65651, Nov. 8, 2006; 78 FR 10348, Feb. 13, 2013; 86 FR 4309, Jan. 15, 2021; 89 FR 32746, Apr. 26, 2024; 89 FR 46008, May 24, 2024]
§ 141.154 - Required additional health information.
Link to an amendment published at 89 FR 86662, Oct. 30, 2024.

(a) All reports must prominently display the following language: Some people may be more vulnerable to contaminants in drinking water than the general population. Immuno-compromised persons such as persons with cancer undergoing chemotherapy, persons who have undergone organ transplants, people with HIV/AIDS or other immune system disorders, some elderly, and infants can be particularly at risk from infections. These people should seek advice about drinking water from their health care providers. EPA/CDC guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contaminants are available from the Safe Drinking Water Hotline (800-426-4791) or on EPA's website epa.gov/safewater.

(b) A system that detects arsenic above 0.005 mg/L and up to and including 0.010 mg/L:

(1) Must include in its report a short informational statement about arsenic, using language such as: Arsenic is known to cause cancer in humans. Arsenic also may cause other health effects such as skin damage and circulatory problems. [NAME OF UTILITY] meets the EPA arsenic drinking water standard, also known as a Maximum Contaminant Level (MCL). However, you should know that EPA's MCL for arsenic balances the scientific community's understanding of arsenic-related health effects and the cost of removing arsenic from drinking water. The highest concentration of arsenic found in [YEAR] was [INSERT MAX ARSENIC LEVEL per § 141.153(d)(4)(iv)] ppb.

(2) May use an alternative educational statement in the CCR if approved by the Primacy Agency.

(c) A system which detects nitrate at levels above 5 mg/l, but below the MCL:

(1) Must include a short informational statement about the impacts of nitrate on children using language such as: Even though [NAME OF UTILITY] meets the EPA nitrate drinking water standard, also known as a Maximum Contaminant Level (MCL), if you are caring for an infant and using tap water to prepare formula, you may want to use alternate sources of water or ask for advice from your health care provider. Nitrate levels above 10 ppm pose a particularly high health concern for infants under 6 months of age and can interfere with the capacity of the infant's blood to carry oxygen, resulting in a serious illness. Symptoms of serious illness include shortness of breath and blueness of the skin, known as “blue baby syndrome.” Nitrate levels in drinking water can increase for short periods of time due to high levels of rainfall or agricultural activity, therefore we test for nitrate [INSERT APPLICABLE SAMPLING FREQUENCY]. The highest level for nitrate found during [YEAR] was [INSERT MAX NITRATE LEVEL per § 141.153(d)(4)(iv)] ppm.

(2) May use an alternative educational statement in the CCR if approved by the Primacy Agency.

(d) Every report must include the following lead-specific information:

(1) A short informational statement about lead in drinking water and its effects on children. The statement must include the following information:

Lead can cause serious health problems, especially for pregnant women and young children. Lead in drinking water is primarily from materials and components associated with service lines and home plumbing. [NAME OF UTILITY] is responsible for providing high quality drinking water and removing lead pipes, but cannot control the variety of materials used in plumbing components in your home. You share the responsibility for protecting yourself and your family from the lead in your home plumbing. You can take responsibility by identifying and removing lead materials within your home plumbing and taking steps to reduce your family's risk. Before drinking tap water, flush your pipes for several minutes by running your tap, taking a shower, doing laundry or a load of dishes. You can also use a filter certified by an American National Standards Institute accredited certifier to reduce lead in drinking water. If you are concerned about lead in your water and wish to have your water tested, contact [NAME OF UTILITY and CONTACT INFORMATION]. Information on lead in drinking water, testing methods, and steps you can take to minimize exposure is available at http://www.epa.gov/safewater/lead.

(2) May use an alternative educational statement in the CCR if approved by the Primacy Agency.

[63 FR 44526, Aug. 19, 1998, as amended at 63 FR 69475, Dec. 16, 1998; 64 FR 34733, June 29, 1999; 65 FR 26023, May 4, 2000; 66 FR 7064, Jan. 22, 2001; 68 FR 14506, Mar. 25, 2003; 72 FR 57820, Oct. 10, 2007; 86 FR 4309, Jan. 15, 2021; 89 FR 46011, May 24, 2024]
§ 141.155 - Report delivery, reporting, and recordkeeping.

(a) Except as provided in paragraph (g) of this section, each community water system must directly deliver a copy of the report to each customer.

(1) Systems must use at a minimum, one of the following forms of delivery:

(i) Mail or hand deliver a paper copy of the report;

(ii) Mail a notification that the report is available on a website via a direct link;

(iii) Email a direct link or electronic version of the report; or

(iv) Another direct delivery method approved in writing by the primacy agency.

(2) Systems using electronic delivery methods in paragraph (a)(1)(ii), (iii), or (iv) of this section must provide a paper copy of the report to any customer upon request. The notification method must prominently display directions for requesting such copy.

(3) For systems that choose to electronically deliver the reports by posting the report to a website and providing a notification either by mail or email:

(i) The report must be publicly available on the website at time notification is made;

(ii) Notifications must prominently display the link and include an explanation of the nature of the link; and

(iii) Systems may use a web page to convey the information required in §§ 141.153, 141.154, and 141.156.

(4) Systems that use a publicly available website to provide reports must maintain public access to the report for no less than 3 years.

(b) The system must make a good faith effort to reach consumers who do not get water bills, using means recommended by the primacy agency. EPA expects that an adequate good faith effort will be tailored to the consumers who are served by the system but are not bill-paying customers, such as renters or workers. A good faith effort to reach consumers includes a mix of methods to reach the broadest possible range of persons served by the water system such as, but not limited to: Posting the reports on the internet; mailing reports or postcards with links to the reports to all service addresses and/or postal customers; using an opt in notification system to send emails and/or texts with links to the reports to interested consumers; advertising the availability of the report in the news media and on social media; publication in a local newspaper or newsletter; posting a copy of the report or notice of availability with links (or equivalent, such as Quick Response (QR) codes) in public places such as cafeterias or lunch rooms of public buildings; delivery of multiple copies for distribution by single-biller customers such as apartment buildings or large private employers; delivery to community organizations; holding a public meeting to educate consumers on the reports.

(i) Where a system is aware that it serves a substantial number of non-bill paying consumers, the system is encouraged to directly deliver the reports or notices of availability of the reports to service addresses.

(ii) Where a system is aware of a substantial number of bill-paying consumers without access to electronic forms of the report, the system should use at least one non-electronic form of delivery.

(c) No later than 10 days after the date the system is required to distribute the report to its customers, each community water system must provide a copy of the report to the primacy agency and a certification that the report(s) has/have been distributed to customers, and that the information is correct and consistent with the compliance monitoring data previously submitted to the primacy agency.

(d) No later than the date the system is required to distribute the report to its customers, each community water system must deliver the report to any other agency or clearinghouse identified by the primacy agency.

(e) Each community water system must make its reports available to the public upon request. Systems should make a reasonable effort to provide the reports in an accessible format to anyone who requests an accommodation.

(f) Each community water system serving 50,000 or more persons must post its current year's report to a publicly-accessible site on the internet.

(g) The Governor of a State or their designee, or the Tribal Leader where the Tribe has met the eligibility requirements contained in § 142.72 for the purposes of waiving the mailing requirement, can waive the requirement of paragraph (a) of this section for community water systems serving fewer than 10,000 persons. In consultation with the tribal government, the Regional Administrator may waive the requirement of § 141.155(a) in areas in Indian country where no tribe has been deemed eligible.

(1) Such systems must:

(i) Publish the reports in one or more local newspapers or on one or more local online news sites serving the area in which the system is located;

(ii) Inform the customers that the reports will not be mailed, either in the newspapers in which the reports are published or by other means approved by the State; and

(iii) Make the reports available to the public upon request.

(2) Systems serving 500 or fewer persons may forego the requirements of paragraphs (g)(1)(i) and (ii) of this section if they provide notice that the report is available upon request at least once per year to their customers by mail, door-to-door delivery or by posting in one or more locations where persons served by the system can reasonably be expected to see it.

(h) Any system subject to this subpart must retain copies of its Consumer Confidence Report for no less than 3 years.

(i) Systems serving 100,000 or more persons, must develop a plan for providing assistance to consumers with limited English proficiency. The system must evaluate the languages spoken by persons with limited English proficiency served by the water system, and the system's anticipated approach to address translation needs. The first plan must be provided to the state with the first report in 2027. Plans must be evaluated annually and updated as necessary and reported with the certification required in paragraph (c) of this section.

(j) Delivery timing and biannual delivery:

(1) Each community water system must distribute reports by July 1 each year. Each report distributed by July 1 must use data collected during, or prior to, the previous calendar year using methods described in paragraph (a) of this section.

(2) Each community water system serving 10,000 or more persons must distribute the report biannually, or twice per calendar year, by December 31 using methods described in paragraph (a) of this section.

(3) Systems required to comply with paragraph (j)(2) of this section, with a violation or action level exceedance that occurred between January 1 and June 30 of the current year, or have received monitoring results from required monitoring under the Unregulated Contaminant Monitoring Rule in § 141.40, must include a 6-month update with the second report with the following:

(i) A short description of the nature of the 6-month update and the biannual delivery.

(ii) If a system receives an MCL, MRDL, or treatment technique violation, the 6-month update must include the applicable contaminant section information in § 141.153(d)(4), and a readily understandable explanation of the violation including: the length of the violation, the potential adverse health effects, actions taken by the system to address the violation, and timeframe the system expects to complete those actions. To describe the potential health effects, the system must use the relevant language of appendix A to this subpart.

(iii) If a system receives any other violation, the 6-month update must include the information in § 141.153(f).

(iv) If a system exceeded the lead action level following monitoring conducted between January 1 and June 30 of the current year, the system must include information identified in § 141.153(d)(4)(vi) and (d)(8).

(v) For systems monitoring under § 141.40 that become aware of results for samples collected during the reporting year but were not included in the reports distributed by July 1, the system must include information as required by § 141.153(d)(7).

(i) Systems serving 100,000 or more persons, must develop a plan for providing assistance to consumers with limited English proficiency. The system must evaluate the languages spoken by persons with limited English proficiency served by the water system, and the system's anticipated approach to address translation needs. The first plan must be provided to the state with the first report in 2027. Plans must be evaluated annually and updated as necessary and reported with the certification required in paragraph (c) of this section.

(j) Delivery timing and biannual delivery:

(1) Each community water system must distribute reports by July 1 each year. Each report distributed by July 1 must use data collected during, or prior to, the previous calendar year using methods described in paragraph (a) of this section.

(2) Each community water system serving 10,000 or more persons must distribute the report biannually, or twice per calendar year, by December 31 using methods described in paragraph (a) of this section.

(3) Systems required to comply with paragraph (j)(2) of this section, with a violation or action level exceedance that occurred between January 1 and June 30 of the current year, or have received monitoring results from required monitoring under the Unregulated Contaminant Monitoring Rule in § 141.40, must include a 6-month update with the second report with the following:

(i) A short description of the nature of the 6-month update and the biannual delivery.

(ii) If a system receives an MCL, MRDL, or treatment technique violation, the 6-month update must include the applicable contaminant section information in § 141.153(d)(4), and a readily understandable explanation of the violation including: the length of the violation, the potential adverse health effects, actions taken by the system to address the violation, and timeframe the system expects to complete those actions. To describe the potential health effects, the system must use the relevant language of appendix A to this subpart.

(iii) If a system receives any other violation, the 6-month update must include the information in § 141.153(f).

(iv) If a system exceeded the lead action level following monitoring conducted between January 1 and June 30 of the current year, the system must include information identified in § 141.153(d)(4)(vi) and (d)(8).

(v) For systems monitoring under § 141.40 that become aware of results for samples collected during the reporting year but were not included in the reports distributed by July 1, the system must include information as required by § 141.153(d)(7).

[63 FR 44526, Aug. 19, 1998, as amended at 65 FR 26023, May 4, 2000; 89 FR 46012, May 24, 2024]
§ 141.156 - Summary of report contents.

(a) Each report must include a summary displayed prominently at the beginning of the report, including a brief description of the nature of the report.

(b) Systems must include, at a minimum, the following information in the summary:

(1) Summary of violations and compliance information included in the report required by § 141.153(d)(6) and (8), (f), and (h)(6) and (7).

(2) Contact information for owner, operator, or designee of the community water system as a source of additional information concerning the report, per § 141.153(h)(2).

(c) If applicable, systems must include the following in the summary:

(1) For systems using delivery methods in § 141.155(a)(1)(ii), (iii), or (iv), the summary must include directions for consumers to request a paper copy of the report, as described in § 141.155(a)(2).

(2) For systems subject to § 141.153(h)(3) because they serve a large proportion of consumers with limited English proficiency, the summary must include information where consumers may obtain a translated copy of the report, or get assistance in the appropriate language(s).

(3) For systems using the report to also meet the public notification requirements of subpart Q of this part, the summary must specify that it is also serving to provide public notification of one or more violations or situations, provide a brief statement about the nature of the notice(s), and a brief description of how to locate the notice(s) in the report.

(d) The summary should be written in plain language and may use infographics.

(e) For those systems required to include a 6-month update with the second report under § 141.155(j)(2), the summary should include a brief description of the nature of the report and update, noting the availability of new information for the current year (between January and June).

(f) The report summary must include the following standard language to encourage the distribution of the report to all persons served:

Please share this information with anyone who drinks this water (or their guardians), especially those who may not have received this report directly (for example, people in apartments, nursing homes, schools, and businesses). You can do this by posting this report in a public place or distributing copies by hand, mail, email, or another method.

[89 FR 46013, May 24, 2024]
Appendix Appendix A - Appendix A to Subpart O of Part 141—Regulated Contaminants
Link to an amendment published at 89 FR 86663, Oct. 30, 2024.
Contaminant (units) Traditional MCL in mg/L To convert for CCR, multiply by MCL in CCR units MCLG Major sources in drinking water Health effects language
Microbiological contaminants:
Total Coliform BacteriaTTTTN/AUse language found in § 141.153(h)(7)(i)(A).
E. coliRoutine and repeat samples are total coliform-positive and either is E. coli-positive or system fails to take repeat samples following E. coli-positive routine sample or system fails to analyze total coliform-positive repeat sample for E. coliRoutine and repeat samples are total coliform-positive and either is E. coli-positive or system fails to take repeat samples following E. coli-positive routine sample or system fails to analyze total coliform-positive repeat sample for E. coli0Human and animal fecal wasteE. coli are bacteria whose presence indicates that the water may be contaminated with human or animal wastes. Human pathogens in these wastes can cause short-term effects, such as diarrhea, cramps, nausea, headaches, or other symptoms. They may pose a greater health risk for infants, young children, the elderly, and people with severely-compromised immune systems.
Fecal Indicators (enterococci or coliphage)TTTTN/AHuman and animal fecal wasteFecal indicators are microbes whose presence indicates that the water may be contaminated with human or animal wastes. Microbes in these wastes can cause short-term health effects, such as diarrhea, cramps, nausea, headaches, or other symptoms. They may pose a special health risk for infants, young children, some of the elderly, and people with severely compromised immune systems.
Total organic carbon (ppm)TTTTN/ANaturally present in the environmentTotal organic carbon (TOC) has no health effects. However, total organic carbon provides a medium for the formation of disinfection by products. These byproducts include trihalomethanes (THMs) and haloacetic acids (HAAs). Drinking water containing these byproducts in excess of the MCL may lead to adverse health effects, liver or kidney problems, or nervous system effects, and may lead to an increased risk of getting cancer.
Turbidity (NTU)TTTTN/ASoil runoffTurbidity has no health effects. However, turbidity can interfere with disinfection and provide a medium for microbial growth. Turbidity may indicate the presence of disease-causing organisms. These organisms include bacteria, viruses, and parasites that can cause symptoms such as nausea, cramps, diarrhea and associated headaches.
Radioactive contaminants:
Beta/photon emitters (mrem/yr)4 mrem/yr40Decay of natural and man-made depositsCertain minerals are radioactive and may emit forms of radiation known as photons and beta radiation. Some people who drink water containing beta particle and photon radioactivity in excess of the MCL over many years may have an increased risk of getting cancer.
Alpha emitters (pCi/L)15 pCi/L150Erosion of natural depositsCertain minerals are radioactive and may emit a form of radiation known as alpha radiation. Some people who drink water containing alpha emitters in excess of the MCL over many years may have an increased risk of getting cancer.
Combined radium (pCi/L)5 pCi/L50Erosion of natural depositsSome people who drink water containing radium-226 or -228 in excess of the MCL over many years may have an increased risk of getting cancer.
Uranium (pCi/L)30 µg/L300Erosion of natural depositsSome people who drink water containing uranium in excess of the MCL over many years may have an increased risk of getting cancer and kidney toxicity.
Inorganic contaminants:
Antimony (ppb).006100066Discharge from petroleum refineries; fire retardants; ceramics; electronics; solderSome people who drink water containing antimony well in excess of the MCL over many years could experience increases in blood cholesterol and decreases in blood sugar.
Arsenic (ppb)0.0101000100Erosion of natural deposits; Runoff from orchards; Runoff from glass and electronics production wastesSome people who drink water containing arsenic in excess of the MCL over many years could experience skin damage or problems with their circulatory system, and may have an increased risk of getting cancer.
Asbestos (MFL)7 MFL77Decay of asbestos cement water mains; Erosion of natural depositsSome people who drink water containing asbestos in excess of the MCL over many years may have an increased risk of developing benign intestinal polyps.
Barium (ppm)222Discharge of drilling wastes; Discharge from metal refineries; Erosion of natural depositsSome people who drink water containing barium in excess of the MCL over many years could experience an increase in their blood pressure.
Beryllium (ppb).004100044Discharge from metal refineries and coal-burning factories; Discharge from electrical, aerospace, and defense industriesSome people who drink water containing beryllium well in excess of the MCL over many years could develop intestinal lesions
Bromate (ppb).0101000100By-product of drinking water disinfectionSome people who drink water of containing bromate in excess of the MCL over many years may have an increased risk of getting cancer.
Cadmium (ppb).005100055Corrosion of galvanized pipes; Erosion of natural deposits; Discharge from metal refineries; Runoff from waste batteries and paintsSome people who drink water containing cadmium in excess of the MCL over many years could experience kidney damage.
Chloramines (ppm)MRDL = 4MRDL = 4MRDLG = 4Water additive used to control microbesSome people who use water containing chloramines well in excess of the MRDL could experience irritating effects to their eyes and nose. Some people who drink water containing chloramines well in excess of the MRDL could experience stomach discomfort or anemia.
Chlorine (ppm)MRDL = 4MRDL = 4MRDLG = 4Water additive used to control microbesSome people who use water containing chlorine well in excess of the MRDL could experience irritating effects to their eyes and nose. Some people who drink water containing chlorine well in excess of the MRDL could experience stomach discomfort.
Chlorine dioxide (ppb)MRDL = .81000MRDL = 800MRDLG = 800Water additive used to control microbesSome infants and young children who drink water chlorine dioxide in excess of the MRDL could experience nervous system effects. Similar effects may occur in fetuses of pregnant women who drink water containing chlorine dioxide in excess of the MRDL. Some people may experience anemia.
Chlorite (ppm)110.8By-product of drinking water disinfectionSome infants and young children who drink water containing chlorite in excess of the MCL could experience nervous system effects. Similar effects may occur in fetuses of pregnant women who drink water containing chlorite in excess of the MCL. Some people may experience anemia.
Chromium (ppb).11000100100Discharge from steel and pulp mills; Erosion of natural depositsSome people who use water containing chromium well in excess of the MCL over many years could experience allergic dermatitis.
Copper (ppm)AL = 1.3AL = 1.31.3Corrosion of household plumbing systems; Erosion of natural depositsCopper is an essential nutrient, but some people who drink water containing copper in excess of the action level over a relatively short amount of time could experience gastrointestinal distress. Some people who drink water containing copper in excess of the action level over many years could suffer liver or kidney damage. People with Wilson's disease should consult their personal doctor.
Cyanide (ppb).21000200200Discharge from steel/metal factories; Discharge from plastic and fertilizer factoriesSome people who drink water containing cyanide well in excess of the MCL over many years could experience nerve damage or problems with their thyroid.
Fluoride (ppm)444Erosion of natural deposits; Water additive which promotes strong teeth; Discharge from fertilizer and aluminum factoriesSome people who drink water containing fluoride in excess of the MCL over many years could get bone disease, including pain and tenderness of the bones. Fluoride in drinking water at half the MCL or more may cause mottling of children's teeth, usually in children less than nine years old. Mottling, also known as dental fluorosis, may include brown staining and/or pitting of the teeth, and occurs only in developing teeth before they erupt from the gums.
LeadAL = .0151000AL = 150Corrosion of household plumbing systems, Erosion of natural deposits.Exposure to lead in drinking water can cause serious health effects in all age groups. Infants and children can have decreases in IQ and attention span. Lead exposure can lead to new learning and behavior problems or exacerbate existing learning and behavior problems. The children of women who are exposed to lead before or during pregnancy can have increased risk of these adverse health effects. Adults can have increased risks of heart disease, high blood pressure, kidney or nervous system problems.
Mercury [inorganic] (ppb).002100022Erosion of natural deposits; Dis charge from refineries and factories; Runoff from landfills; Runoff from croplandSome people who drink water containing inorganic mercury well in excess of the MCL over many years could experience kidney damage.
Nitrate (ppm)101010Runoff from fertilizer use; Leaching from septic tanks, sew age; Erosion of natural depositsInfants below the age of six months who drink water containing nitrate in excess of the MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue baby syndrome.
Nitrite (ppm)111Runoff from fertilizer use; Leaching from septic tanks, sew age; Erosion of natural depositsInfants below the age of six months who drink water containing nitrite in excess of the MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue baby syndrome.
Selenium (ppb).0510005050Discharge from petroleum and metal refineries; Erosion of natural deposits; Discharge from minesSelenium is an essential nutrient. However, some people who drink water containing selenium in excess of the MCL over many years could experience hair or fingernail losses, numbness in fingers or toes, or problems with their circulation.
Thallium (ppb).002100020.5Leaching from ore-processing sites; Discharge from electronics, glass, and drug factoriesSome people who drink water containing thallium in excess of the MCL over many years could experience hair loss, changes in their blood, or problems with their kidneys, intestines, or liver.
Synthetic organic contaminants including pesticides and herbicides:
2,4-D (ppb).0710007070Runoff from herbicide used on row cropsSome people who drink water containing the weed killer 2,4-D well in excess of the MCL over many years could experience problems with their kidneys, liver, or adrenal glands.
2,4,5-TP [Silvex](ppb).0510005050Residue of banned herbicideSome people who drink water containing silvex in excess of the MCL over many years could experience liver problems.
AcrylamideTTTT0Added to water during sewage/wastewater treatmentSome people who drink water containing high levels of acrylamide over a long period of time could have problems with their nervous system or blood, and may have an increased risk of getting cancer.
Alachlor (ppb).002100020Runoff from herbicide used on row cropsSome people who drink water containing alachlor in excess of the MCL over many years could have problems with their eyes, liver, kidneys, or spleen, or experience anemia, and may have an increased risk of getting cancer.
Atrazine (ppb).003100033Runoff from herbicide used on row cropsSome people who drink water containing atrazine well in excess of the MCL over many years could experience problems with their cardiovascular system or reproductive difficulties.
Benzo(a)pyrene [PAH] (nanograms/l).00021,000,0002000Leaching from linings of water storage tanks and distribution linesSome people who drink water containing benzo(a)pyrene in excess of the MCL over many years may experience reproductive difficulties and may have an increased risk of getting cancer.
Carbofuran (ppb).0410004040Leaching of soil fumigant used on rice and alfalfaSome people who drink water containing carbofuran in excess of the MCL over many years could experience problems with their blood, or nervous or reproductive systems.
Chlordane (ppb).002100020Residue of banned termiticideSome people who drink water containing chlordane in excess of the MCL over many years could experience problems with their liver or nervous system, and may have an increased risk of getting cancer.
Dalapon (ppb).21000200200Runoff from herbicide used on rights of waySome people who drink water containing dalapon well in excess of the MCL over many years could experience minor kidney changes.
Di(2-ethylhexyl) adipate (ppb).41000400400Discharge from chemical factoriesSome people who drink water containing di(2-ethylhexyl) adipate well in excess of the MCL over many years could experience toxic effects such as weight loss, liver enlargement or possible reproductive difficulties.
Di(2-ethylhexyl) phthalate (ppb).006100060Discharge from rubber and chemical factoriesSome people who drink water containing di(2-ethylhexyl) phthalate well in excess of the MCL over many years may have problems with their liver, or experience reproductive difficulties, and may have an increased risk of getting cancer.
Dibromochloropropane (ppt).00021,000,0002000Runoff/leaching from soil fumigant used on soybeans, cotton, pineapples, and orchardsSome people who drink water containing DBCP in excess of the MCL over many years could experience reproductive problems and may have an increased risk of getting cancer.
Dinoseb (ppb).007100077Runoff from herbicide used on soybeans and vegetablesSome people who drink water containing dinoseb well in excess of the MCL over many years could experience reproductive difficulties.
Diquat (ppb).0210002020Runoff from herbicide useSome people who drink water containing diquat in excess of the MCL over many years could get cataracts.
Dioxin [2,3,7,8-TCDD] (ppq).000000031,000,000, 000300Emissions from waste incineration and other combustion; Discharge from chemical factoriesSome people who drink water containing dioxin in excess of the MCL over many years could experience reproductive difficulties and may have an increased risk of getting cancer.
Endothall (ppb).11000100100Runoff from herbicide useSome people who drink water containing endothall in excess of the MCL over many years could experience problems with their stomach or intestines.
Endrin (ppb).002100022Residue of banned insecticideSome people who drink water containing endrin in excess of the MCL over many years could experience liver problems.
EpichlorohydrinTTTT0Discharge from industrial chemical factories; An impurity of some water treatment chemicalsSome people who drink water containing high levels of epichlorohydrin over a long period of time could experience stomach problems, and may have an increased risk of getting cancer.
Ethylene dibromide (ppt).000051,000,000500Discharge from petroleum refineriesSome people who drink water containing ethylene dibromide in excess of the MCL over many years could experience problems with their liver, stomach, reproductive system, or kidneys, and may have an increased risk of getting cancer.
Glyphosate (ppb).71000700700Runoff from herbicide useSome people who drink water containing glyphosate in excess of the MCL over many years could experience problems with their kidneys or reproductive difficulties.
Hazard Index PFAS (HFPO-DA, PFBS, PFHxS, and PFNA) (unitless)1 (unitless)11Discharge from manufacturing and industrial chemical facilities, use of certain consumer products, occupational exposures, and certain firefighting activitiesPer- and polyfluoroalkyl substances (PFAS) can persist in the human body and exposure may lead to increased risk of adverse health effects. Low levels of multiple PFAS that individually would not likely result in increased risk of adverse health effects may result in adverse health effects when combined in a mixture. Some people who consume drinking water containing mixtures of PFAS in excess of the Hazard Index (HI) MCL may have increased health risks such as liver, immune, and thyroid effects following exposure over many years and developmental and thyroid effects following repeated exposure during pregnancy and/or childhood.
Heptachlor (ppt).00041,000,0004000Residue of banned pesticideSome people who drink water containing heptachlor in excess of the MCL over many years could experience liver damage and may have an increased risk of getting cancer.
Heptachlor epoxide (ppt).00021,000,0002000Breakdown of heptachlorSome people who drink water containing heptachlor epoxide in excess of the MCL over many years could experience liver damage, and may have an increased risk of getting cancer.
Hexachlorobenzene (ppb).001100010Discharge from metal refineries and agricultural chemical factoriesSome people who drink water containing hexachlorobenzene in excess of the MCL over many years could experience problems with their liver or kidneys, or adverse reproductive effects, and may have an increased risk of getting cancer.
Hexachlorocyclopentadiene (ppb).0510005050Discharge from chemical factoriesSome people who drink water containing hexachlorocyclopentadiene well in excess of the MCL over many years could experience problems with their kidneys or stomach.
HFPO-DA (ng/l)0.000011,000,0001010Discharge from manufacturing and industrial chemical facilities, use of certain consumer products, occupational exposures, and certain firefighting activitiesSome people who drink water containing HFPO-DA in excess of the MCL over many years may have increased health risks such as immune, liver, and kidney effects. There is also a potential concern for cancer associated with HFPO-DA exposure. In addition, there may be increased risks of developmental effects for people who drink water containing HFPO-DA in excess of the MCL following repeated exposure during pregnancy and/or childhood.
Lindane (ppt).00021,000,000200200Runoff/leaching from insecticide used on cattle, lumber, gardensSome people who drink water containing lindane in excess of the MCL over many years could experience problems with their kidneys or liver.
Methoxychlor (ppb).0410004040Runoff/leaching from insecticide used on fruits, vegetables, alfalfa, livestockSome people who drink water containing methoxychlor in excess of the MCL over many years could experience reproductive difficulties.
Oxamyl [Vydate] (ppb).21000200200Runoff/leaching from insecticide used on apples, potatoes and tomatoesSome people who drink water containing oxamyl in excess of the MCL over many years could experience slight nervous system effects.
PCBs [Polychlorinated biphenyls] (ppt).00051,000,0005000Runoff from landfills; Discharge of waste chemicalsSome people who drink water containing PCBs in excess of the MCL over many years could experience changes in their skin, problems with their thymus gland, immune deficiencies, or reproductive or nervous system difficulties, and may have an increased risk of getting cancer.
Pentachlorophenol (ppb).001100010Discharge from wood preserving factoriesSome people who drink water containing pentachlorophenol in excess of the MCL over many years could experience problems with their liver or kidneys, and may have an increased risk of getting cancer.
PFHxS (ng/l)0.000011,000,0001010Discharge from manufacturing and industrial chemical facilities, use of certain consumer products, occupational exposures, and certain firefighting activitiesSome people who drink water containing PFHxS in excess of the MCL over many years may have increased health risks such as immune, thyroid, and liver effects. In addition, there may be increased risks of developmental effects for people who drink water containing PFHxS in excess of the MCL following repeated exposure during pregnancy and/or childhood.
PFNA (ng/l)0.000011,000,0001010Discharge from manufacturing and industrial chemical facilities, use of certain consumer products, occupational exposures, and certain firefighting activitiesSome people who drink water containing PFNA in excess of the MCL over many years may have increased health risks such as elevated cholesterol levels, immune effects, and liver effects. In addition, there may be increased risks of developmental effects for people who drink water containing PFNA in excess of the MCL following repeated exposure during pregnancy and/or childhood.
PFOA (ng/l)0.00000401,000,0004.00Discharge from manufacturing and industrial chemical facilities, use of certain consumer products, occupational exposures, and certain firefighting activitiesSome people who drink water containing PFOA in excess of the MCL over many years may have increased health risks such as cardiovascular, immune, and liver effects, as well as increased incidence of certain types of cancers including kidney and testicular cancer. In addition, there may be increased risks of developmental and immune effects for people who drink water containing PFOA in excess of the MCL following repeated exposure during pregnancy and/or childhood.
PFOS (ng/l)0.00000401,000,0004.00Discharge from manufacturing and industrial chemical facilities, use of certain consumer products, occupational exposures, and certain firefighting activitiesSome people who drink water containing PFOS in excess of the MCL over many years may have increased health risks such as cardiovascular, immune, and liver effects, as well as increased incidence of certain types of cancers including liver cancer. In addition, there may be increased risks of developmental and immune effects for people who drink water containing PFOS in excess of the MCL following repeated exposure during pregnancy and/or childhood.
Picloram (ppb).51000500500Herbicide runoffSome people who drink water containing picloram in excess of the MCL over many years could experience problems with their liver.
Simazine (ppb).004100044Herbicide runoffSome people who drink water containing simazine in excess of the MCL over many years could experience problems with their blood.
Toxaphene (ppb).003100030Runoff/leaching from insecticide used on cotton and cattleSome people who drink water containing toxaphene in excess of the MCL over many years could have problems with their kidneys, liver, or thyroid, and may have an increased risk of getting cancer.
Volatile organic contaminants:
Benzene (ppb).005100050Discharge from factories; Leaching from gas storage tanks and landfillsSome people who drink water containing benzene in excess of the MCL over many years could experience anemia or a decrease in blood platelets, and may have an increased risk of getting cancer.
Carbon tetrachloride (ppb).005100050Discharge from chemical plants and other industrial activitiesSome people who drink water containing carbon tetrachloride in excess of the MCL over many years could experience problems with their liver and may have an increased risk of getting cancer.
Chlorobenzene (ppb).11000100100Discharge from chemical and agricultural chemical factoriesSome people who drink water containing chlorobenzene in excess of the MCL over many years could experience problems with their liver or kidneys.
o-Dichlorobenzene (ppb).61000600600Discharge from industrial chemical factoriesSome people who drink water containing o-dichlorobenzene well in excess of the MCL over many years could experience problems with their liver, kidneys, or circulatory systems.
p-Dichlorobenzene (ppb).07510007575Discharge from industrial chemical factoriesSome people who drink water containing p-dichlorobenzene in excess of the MCL over many years could experience anemia, damage to their liver, kidneys, or spleen, or changes in their blood.
1,2-Dichloroethane (ppb).005100050Discharge from industrial chemical factoriesSome people who drink water containing 1,2-dichloroethane in excess of the MCL over many years may have an increased risk of getting cancer.
1,1-Dichloroethylene (ppb).007100077Discharge from industrial chemical factoriesSome people who drink water containing 1,1-dichloroethylene in excess of the MCL over many years could experience problems with their liver.
cis-1,2-Dichloroethylene (ppb).0710007070Discharge from industrial chemical factoriesSome people who drink water containing cis-1,2-dichloroethylene in excess of the MCL over many years could experience problems with their liver.
trans-1,2-Dichloroethylene (ppb).11000100100Discharge from industrial chemical factoriesSome people who drink water containing trans-1,2-dichloroethylene well in excess of the MCL over many years could experience problems with their liver.
Dichloromethane (ppb).005100050Discharge from pharmaceutical and chemical factoriesSome people who drink water containing dichloromethane in excess of the MCL over many years could have liver problems and may have an increased risk of getting cancer.
1,2-Dichloropropane (ppb).005100050Discharge from industrial chemical factoriesSome people who drink water containing 1,2-dichloropropane in excess of the MCL over many years may have an increased risk of getting cancer.
Ethylbenzene (ppb).71000700700Discharge from petroleum refineriesSome people who drink water containing ethylbenzene well in excess of the MCL over many years could experience problems with their liver or kidneys.
Haloacetic Acids (HAA) (ppb).060100060N/ABy-product of drinking water disinfectionSome people who drink water containing haloacetic acids in excess of the MCL over many years may have an increased risk of getting cancer.
Styrene (ppb).11000100100Discharge from rubber and plastic factories; Leaching from landfillsSome people who drink water containing styrene well in excess of the MCL over many years could have problems with their liver, kidneys, or circulatory system.
Tetrachloroethylene (ppb).005100050Discharge from factories and dry cleanersSome people who drink water containing tetrachloroethylene in excess of the MCL over many years could have problems with their liver, and may have an increased risk of getting cancer.
1,2,4-Trichlorobenzene (ppb).0710007070Discharge from textile-finishing factoriesSome people who drink water containing 1,2,4-trichlorobenzene well in excess of the MCL over many years could experience changes in their adrenal glands.
1,1,1-Trichloroethane (ppb).21000200200Discharge from metal degreasing sites and other factoriesSome people who drink water containing 1,1,1-trichloroethane in excess of the MCL over many years could experience problems with their liver, nervous system, or circulatory system.
1,1,2-Trichloroethane (ppb).005100053Discharge from industrial chemical factoriesSome people who drink water containing 1,1,2-trichloroethane well in excess of the MCL over many years could have problems with their liver, kidneys, or immune systems.
Trichloroethylene (ppb).005100050Discharge from metal degreasing sites and other factoriesSome people who drink water containing trichloroethylene in excess of the MCL over many years could experience problems with their liver and may have an increased risk of getting cancer.
TTHMs [Total trihalomethanes] (ppb)0.10/.0801000100/80N/ABy-product of drinking water disinfectionSome people who drink water containing trihalomethanes in excess of the MCL over many years may experience problems with their liver, kidneys, or central nervous systems, and may have an increased risk of getting cancer.
Toluene (ppm)111Discharge from petroleum factoriesSome people who drink water containing toluene well in excess of the MCL over many years could have problems with their nervous system, kidneys, or liver.
Vinyl Chloride (ppb).002100020Leaching from PVC piping; Discharge from plastics factoriesSome people who drink water containing vinyl chloride in excess of the MCL over many years may have an increased risk of getting cancer.
Xylenes (ppm)101010Discharge from petroleum factories; Discharge from chemical factoriesSome people who drink water containing xylenes in excess of the MCL over many years could experience damage to their nervous system.

Key:

AL = Action Level

MCL = Maximum Contaminant Level

MCLG = Maximum Contaminant Level Goal

MFL = million fibers per liter

MRDL = Maximum Residual Disinfectant Level

MRDLG = Maximum Residual Disinfectant Level Goal

mrem/year = millirems per year (a measure of radiation absorbed by the body)

N/A = Not Applicable

NTU = Nephelometric Turbidity Units (a measure of water clarity)

pCi/l = picocuries per liter (a measure of radioactivity)

ppm = parts per million, or milligrams per liter (mg/l)

ppb = parts per billion, or micrograms per liter (µg/l)

ppt = parts per trillion, or nanograms per liter

ppq = parts per quadrillion, or picograms per liter

TT = Treatment Technique

[65 FR 26024, May 4, 2000, as amended at 65 FR 76749, Dec. 7, 2000; 66 FR 7064, Jan. 22, 2001; 67 FR 70855, Nov. 27, 2002; 67 FR 73011, Dec. 9, 2002; 68 FR 14506, Mar. 25, 2003; 71 FR 65652, Nov. 8, 2006; 78 FR 10349, Feb. 13, 2013; 86 FR 4309, Jan. 15, 2021; 89 FR 32746, Apr. 26, 2024]
source: 40 FR 59570, Dec. 24, 1975, unless otherwise noted.
cite as: 40 CFR 141.154