Safe Drinking Water Act, United States

April 13, 2011, 7:03 pm
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The Safe Drinking Water Act (SDWA), Title XIV of the Public Health Service Act, is the key federal law for protecting public water supplies from harmful contaminants. First enacted in 1974 and substantively amended in 1986 and 1996, the act is administered through programs that establish standards and treatment requirements for public water supplies, control underground injection of wastes, finance infrastructure projects, and protect sources of drinking water. The 1974 law established the current federal-state arrangement in which states may be delegated primary implementation and enforcement authority for the drinking water program. The stateadministered Public Water Supply Supervision (PWSS) Program remains the basic program for regulating the nation’s public water systems, and 49 states have assumed this authority. SDWA appropriations were authorized through FY2003.


Table 1. Safe Drinking Water Act and Amendments
(codified generally at 42 U.S.C. 300f-300j-25)
Year Act Public Law Number
1974    Safe Drinking Water Act of 1974 P.L. 93-523
1977    Safe Drinking Water Act Amendments of 1977 P.L. 95-190
1979    Safe Drinking Water Act Amendments P.L. 96-63
1980    Safe Drinking Water Act Amendments P.L. 96-502
1986    Safe Drinking Water Act Amendments of 1986 P.L. 99-339
1988    Lead Contamination Control Act of 1988 P.L. 100-572
1996    Safe Drinking Water Act Amendments of 1996 P.L. 104-182
2002    Public Health Security and Bioterrorism Preparedness and Response Act of 2002 P.L. 107-188


As indicated in Table 1, the Safe Drinking Water Act has been amended several times since enactment of the Safe Drinking Water Act of 1974 (P.L. 93-523). Congress enacted P.L. 93-523 after nationwide studies of community water systems revealed widespread water quality problems and health risks resulting from poor operating procedures, inadequate facilities, and poor management of public water supplies in communities of all sizes. The 1974 law gave the Environmental Protection Agency (EPA) substantial discretionary authority to regulate drinking water contaminants and gave states the lead role in implementation and enforcement.

The first major amendments (P.L. 99-339), enacted in 1986, were largely intended to increase the pace at which EPA regulated contaminants. From 1974 until 1986, EPA had regulated just one additional contaminant beyond the 22 standards previously developed by the Public Health Service. The 1986 amendments required EPA to (1) issue regulations for 83 specified contaminants by June 1989 and for 25 more contaminants every three years thereafter, (2) promulgate requirements for disinfection and filtration of public water supplies, (3) ban the use of lead pipes and lead solder in new drinking water systems, (4) establish an elective wellhead protection program around public wells, (5) establish a demonstration grant program for state and local authorities having designated sole-source aquifers to develop groundwater protection programs, and (6) issue rules for monitoring injection wells that inject wastes below a drinking water source. The amendments also increased EPA’s enforcement authority.

The Lead Contamination Control Act of 1988 (P.L. 100-572) added a new Part F to the SDWA. These provisions were intended to reduce exposure to lead in drinking water by requiring the recall of lead-lined water coolers, and requiring EPA to issue a guidance document and testing protocol for states to help schools and day care centers identify and correct lead contamination in school drinking water.

After the regulatory schedule mandated in the 1986 amendments proved to be unworkable for EPA, states and public water systems, the 104th Congress made sweeping changes to the act with the SDWA Amendments of 1996 (P.L. 104-182). As over-arching themes, these amendments aimed to target resources to address the greatest health risks, add some regulatory flexibility, provide funding for federal drinking water mandates, and improve water systems’ compliance capacity. The amendments revoked the requirement that EPA regulate 25 new contaminants every three years, and provided a risk-based approach for selecting contaminants for regulation. Among other changes, Congress added some flexibility to the standard-setting process, required EPA to conduct health risk reduction and cost analyses for most new standards, authorized a state revolving loan fund (SRF) program to help public water systems finance projects needed to meet SDWA requirements, added programs to improve small system compliance, expanded consumer information requirements, increased the act’s focus on pollution prevention through a voluntary source water protection program, and streamlined the act’s enforcement provisions. P.L. 104-182 extended authorizations for appropriations under the act through FY2003.

In June 2002, drinking water security provisions were added to the SDWA through the Public Heath Security and Bioterrorism Preparedness and Response Act of 2002 (P.L. 107-188). Key provisions of the act include requirements for community water systems serving more than 3,300 individuals to conduct vulnerability assessments and prepare emergency preparedness and response plans and requirements for EPA to conduct research on preventing and responding to terrorist or other attacks.

National Drinking Water Regulations

A key component of the SDWA is the requirement that EPA promulgate national primary drinking water regulations for contaminants that may pose health risks and that are likely to be present in public water supplies. Section 1412 instructs EPA on how to select contaminants for regulation and specifies how EPA must establish regulations once a contaminant has been selected. The regulations apply to the roughly 168,000 privately and publicly owned water systems that provide piped water for human consumption to at least 15 service connections or that regularly serve at least 25 people. EPA has issued regulations for roughly 90 contaminants.

Contaminant Selection and Regulatory Schedules

Section 1412, as amended in 1996, directs EPA to select contaminants for regulatory consideration based on occurrence, health effects, and meaningful opportunity for health risk reduction. Starting in 1998, and every five years thereafter, EPA must publish a list of contaminants that may warrant regulation. Starting in 2001, and every five years thereafter, EPA must determine whether or not to regulate at least five of the listed contaminants. The act requires EPA to evaluate contaminants that present the greatest health concern and to regulate contaminants that occur at concentration levels and frequencies of public health concern. The amendments also included schedules for EPA to complete regulations for specific contaminants (i.e., radon, arsenic, disinfectants and disinfection byproducts, and Cryptosproridium).

Standard Setting

For each contaminant that EPA determines requires regulation, EPA must set a non-enforceable maximum contaminant level goal (MCLG) at a level at which no known or anticipated adverse health effects occur and which allows an adequate margin of safety. EPA must then set an enforceable standard, a maximum contaminant level (MCL), as close to the MCLG as is “feasible” using best technology, treatment techniques, or other means available (taking costs into consideration). EPA generally sets standards based on technologies that are affordable for large communities; however, under P.L. 104-182, EPA is now required, when issuing a regulation for a contaminant, to list any technologies or other means that comply with the MCL and that are affordable for three categories of small public water systems (serving populations of 10,000 or fewer). If EPA does not identify technologies that are affordable for small systems, then EPA must identify small system “variance” technologies or other means that may not achieve the MCL but are protective of public health.

Another provision added in 1996 requires EPA, when proposing a regulation, to publish a determination as to whether or not the benefits of the standard justify the costs. If EPA determines that the benefits do not justify the costs, EPA may, with certain exceptions, promulgate a standard that maximizes health risk reduction benefits at a cost that is justified by the benefits. New SDWA regulations generally become effective three years after promulgation. Up to two additional years may be allowed if EPA (or a state in the case of an individual system) determines the time is needed for capital improvements. Section 1448 outlines procedures for judicial review of EPA actions involving the establishment of SDWA regulations and other final EPA actions.

Risk Assessment

The 1996 amendments also added risk assessment and risk communication provisions to SDWA. When developing regulations, EPA is required to (1) use the best available, peer-reviewed science and supporting studies and data; and (2) make publicly available a risk assessment document that discusses estimated risks, uncertainties, and studies used in the assessment. When proposing drinking water regulations, EPA must publish a health risk reduction and cost analysis (HRRCA). EPA may promulgate an interim standard without first preparing this benefit-cost analysis or making a determination as to whether the benefits of a regulation would justify the costs if EPA determines that a contaminant presents an urgent threat to public health.

Variances and Exemptions

In anticipation that some systems, particularly smaller ones, could have difficulty complying with every regulation, Congress included in the SDWA provisions for variances and exemptions. Section 1415 authorizes a state to grant a public water system a variance from a standard if raw water quality prevents the standard from being met despite application of best technology, and the variance does not result in an unreasonable risk to health. A 1996 provision (Subsection 1415(e)) authorizes variances specifically for small systems based on application of best affordable technology.

When developing a regulation, if EPA cannot identify a technology that meets the standard and is affordable for small systems, EPA must identify variance technologies that are affordable but do not necessarily meet the standard. In cases where EPA has identified variance technologies, states may grant small system variances to systems serving 3,300 or fewer persons if the system cannot afford to comply with a standard (through treatment, an alternative water source, or restructuring) and the variance ensures adequate protection of public health. States also may grant these variances to systems serving between 3,301 and 10,000 persons with EPA approval. To receive a small system variance, the system must install a variance technology.

Section 1416 authorizes states to grant public water systems temporary exemptions from standards or treatment techniques if a system cannot comply for other compelling reasons (including costs). An exemption is intended to give a water system more time to comply with a regulation and can be issued only if it will not result in an unreasonable health risk. A qualified system may receive an exemption for up to three years beyond the compliance deadline. Systems serving 3,300 or fewer persons may receive a maximum of three additional two-year extensions, for a total exemption duration of nine years.

State Primacy

Section 1413 authorizes states to assume primary oversight and enforcement responsibility (primacy) for public water systems. To assume primacy, states must adopt regulations at least as stringent as national requirements, develop adequate procedures for enforcement, adopt authority for administrative penalties, maintain records, and develop a plan for providing emergency water supplies. Currently, 55 of 57 states and territories have primacy authority. The act authorizes $100 million annually for EPA to make grants to states to administer the Public Water System Supervision Program. States may also use part of their SRF grant for this purpose.

Enforcement, Consumer Information, and Citizen Suits

The Safe Drinking Water Act requires public water systems to monitor their water supplies to ensure compliance with drinking water standards and to report monitoring results to the states. States review monitoring data submitted by public water systems, or conduct their own monitoring, to determine system compliance with drinking water regulations. EPA monitors public water system compliance primarily by reviewing the violation data submitted by the states. Section 1414 requires that, whenever EPA finds that a public water system in a state with primary enforcement authority does not comply with regulations, the agency must notify the state and the system and provide assistance to bring the system into compliance. If the state fails to commence enforcement action within 30 days after the notification, EPA is authorized to issue an administrative order or commence a civil action. In a non-primacy state, EPA must notify an elected local official (if any has jurisdiction over the water system) before commencing an enforcement action against the system.

The 1996 amendments strengthened enforcement authorities, streamlined the process for issuing federal administrative orders, increased administrative penalty amounts, made more sections of the act clearly subject to EPA enforcement, and required states (as a condition of primacy) to have administrative penalty authority. The amendments also provided that no enforcement action may be taken against a public water system that has a plan to consolidate with another system.

Consumer Information and Reports

Enforcement provisions also require public water systems to notify customers of violations of drinking water standards or other requirements, such as monitoring and reporting. Systems must notify customers within 24 hours of any violations that have the potential to cause serious health effects as a result of short-term exposure (e.g., violations of microbial standards). The amendments also require community water systems to mail to all customers an annual “ consumer confidence report” on contaminants detected in their drinking water. States must prepare annual reports on the compliance of public water systems and make summaries available to EPA and the public, and EPA must prepare annual national compliance reports.

Citizen Suits

Section 1449 provides for citizens’ civil actions. Citizen suits may be brought against any person or agency allegedly in violation of provisions of the act, or against the Administrator for alleged failure to perform any action or duty that is not discretionary.

Compliance Improvement Programs

The 1996 amendments added two state-administered programs aimed at improving public water system compliance with drinking water regulations: the operator certification program and the capacity development program. Section 1419 required states to adopt programs for training and certifying operators of community and non-transient non-community systems (e.g., schools and workplaces that have their own wells). In 1999, EPA issued guidelines specifying minimum certification standards. EPA is required to withhold 20% of a state’s revolving fund (SRF) annual grant unless the state has adopted and is implementing an operator certification program. Section 1420 required states to establish capacity development programs, also based on EPA guidance. These programs must include (1) legal authority to ensure that new systems have the technical, financial, and managerial capacity to meet SDWA requirements; and (2) a strategy to assist existing systems that are experiencing difficulties to come into compliance. EPA is required to withhold a portion of SRF grants from states that do not have capacity development strategies.

Ground Water Protection Programs

Most small water systems rely on ground water as a source of drinking water, and Part C of the act focuses on ground water protection. Section 1421 authorized the establishment of state underground injection control (UIC) programs to protect underground sources of drinking water.

In 1977, EPA issued mandated regulations containing minimum requirements for the underground injection of wastes into five classes of disposal wells and requiring states to prohibit any underground injection not authorized by state permit. The law specified that the regulations could not interfere with the underground injection of brine from oil and gas production or recovery of oil unless underground sources of drinking water would be affected. Section 1422 authorized affected states to submit plans to EPA for implementing UIC programs and, if approved, to assume primary enforcement responsibility. EPA is required to implement the program if a state’s plan has not been approved or the state has chosen not to assume program responsibility (Section 1423). For oil and gas injection operations only, states with UIC programs are delegated primary enforcement authority without meeting EPA regulations (Section 1425).

Section 1424(e) authorizes EPA to make determinations, on EPA’s initiative or upon petition, that an aquifer is the sole or principal drinking water source for an area. In areas that overlie a designated sole-source aquifer, no federal funding may be committed for projects that EPA determines may contaminate such an aquifer. Any person may petition for sole source aquifer designation.

The act contains three additional state programs aimed specifically at protecting ground water. Added in 1986, Section 1427 established procedures for demonstration programs to develop, implement, and assess critical aquifer protection areas already designated by the Administrator as sole source aquifers. Section 1428, also added in 1986, established an elective state program for protecting wellhead areas around public water system wells. If a state established a wellhead protection program by 1989, and EPA approved the state’s program, then EPA may award grants covering between 50% and 90% of the costs of implementing the program. Section 1429, added in 1996, authorizes EPA to make 50% grants to states to develop programs to ensure coordinated and comprehensive protection of ground water within the states. Appropriations for these three programs and for UIC state program grants were authorized through FY2003.

Source Water Assessment and Protection Programs

In 1996, Congress broadened the act’s pollution prevention focus to embrace surface water, in addition to ground water, protection. Section 1453 required EPA to publish guidance for states to implement source water assessment programs that delineate boundaries of areas from which systems receive their water, and identify the origins of contaminants in delineated areas to determine systems’ susceptibility to contamination. States with approved assessment programs may adopt alternative monitoring requirements to provide systems with monitoring relief provided under Section 1418.

Section 1454 authorized a source water petition program based on voluntary partnerships between state and local governments. States may establish a program under which a community water system or local government may submit a petition to the state requesting assistance in developing a voluntary source water quality protection partnership to (1) reduce the presence of contaminants in drinking water; (2) receive financial or technical assistance; and (3) develop a long-term source water protection strategy. This section authorized, through FY2003, $5 million each year for grants to states to support petition programs. States also may use 10% of their annual SRF grant to support various source water protection activities including the petition program.

State Revolving Funds

In 1996, Congress authorized a drinking water state revolving loan fund (DWSRF) program to help systems finance improvements needed to comply with SDWA regulations (Section 1452). EPA is authorized to make grants to states to capitalize DWSRFs, which states then may use to make loans to public water systems. States must match 20% of the federal grant, and grants are allotted among the states based on the results of the latest quadrennial needs survey. Each state and the District of Columbia must receive at least 1% of the appropriated funds. A state may transfer up to 33% of the grant to the Clean Water Act (CWA) SRF, or an equivalent amount from the CWA SRF to the DWSRF through FY2002. This authority has been extended in subsequent appropriations acts.

DWSRFs may be used to provide loans for expenditures EPA has determined will facilitate compliance or significantly further the act’s health protection objectives. States must make available 15% of their annual allotment for loan assistance to systems that serve 10,000 or fewer persons, to the extent that funds can be obligated for eligible projects. States may use up to 30% of their DWSRF grant to provide loan subsidies (including forgiveness of principal) to help economically disadvantaged communities. Also, states may use a portion of funds for technical assistance, source water protection and capacity development programs, and for operator certification. The law authorized appropriations of $599 million for FY1994 and $1 billion per year for FY1995 through FY2003 for the DWSRF program.

Drinking Water Security

The 107th Congress passed the Public Health Security and Bioterrorism Preparedness and Response Act of 2002 (P.L. 107-188). Title IV of the Bioterrorism Act amended the SDWA to address threats to drinking water security. Key provisions are summarized below.

Vulnerability Assessments

Section 1433 was added to SDWA, requiring each community water system serving more than 3,300 individuals to conduct an assessment of the system’s vulnerability to terrorist attacks or other intentional acts to disrupt the provision of a safe and reliable drinking water supply. This provision established deadlines, based on system size, for community water systems to certify to EPA that they had conducted a vulnerability assessment and to submit to EPA a copy of the assessment. The law required all these systems to complete vulnerability assessments by June 30, 2004, or earlier. Section 1433 exempts the contents of the vulnerability assessments from disclosure under the Freedom of Information Act (except for information contained in the certification identifying the system and the date of the certification), and provides for civil and criminal penalties for inappropriate disclosure of information by government officials.

In addition, Section 1433 required each community water system serving more than 3,300 individuals to prepare or revise an emergency response plan incorporating the results of the vulnerability assessment. EPA was required to provide guidance to smaller systems on how to conduct vulnerability assessments, prepare emergency response plans, and address threats.

The act authorized $160 million for FY2002, and such sums as may be necessary for FY2003 through FY2005, to provide financial assistance to community water systems to conduct vulnerability assessments, to prepare response plans, and to address basic security enhancements and significant threats.

The Bioterrorism Act also added new SDWA Sections 1434 and 1435 directing the EPA Administrator to review methods by which terrorists or others could disrupt the provision of safe water supplies. EPA was required to review methods for preventing, detecting, and responding to such disruptions, and methods for providing alternative drinking water supplies if a water system was destroyed or impaired. The act authorized $15 million for FY2002, and such sums as may be necessary for FY2003 through FY2005 to carry out these sections.

Emergency Powers

Under Section 1431, the Administrator has emergency powers to issue orders and commence civil action if (1) a contaminant likely to enter a public water supply system poses a substantial threat to public health, and (2) state or local officials have not taken adequate action. The Bioterrorism Act amended this section to specify that EPA’s emergency powers include the authority to act when there is a threatened or potential terrorist attack or other intentional act to disrupt the provision of safe drinking water or to impact the safety of a community’s water supply.

Tampering with Public Water Systems

Section 1432 provides for civil and criminal penalties against any person who tampers, attempts to tamper, or makes a threat to tamper with a public water system. Amendments made by the Bioterrorism Act increased criminal and civil penalties for tampering, attempting to tamper, or making threats to tamper with public water supplies. The maximum prison sentence for tampering was increased from 5 to 20 years. The maximum prison sentence for attempting to tamper, or making threats to tamper, was increased from 3 to 10 years. The maximum fine that may be imposed for tampering was increased from $50,000 to $1 million. The maximum fine for attempting to tamper, or threatening to tamper, was increased from $20,000 to $100,000.

Emergency Assistance

SDWA Subsection 1442(b) authorizes EPA to provide technical assistance and to make grants to states and public water systems to assist in responding to and alleviating emergency situations. The Bioterrorism Act amended Subsection 1442(d) to authorize appropriations for such emergency assistance of not more than $35 million for FY2002, and such sums as may be necessary for each fiscal year thereafter.

Other Selected Provisions

Section 1417 prohibits the use of pipe, solder, or flux that is not “lead free” (as defined by the SDWA) in the installation or repair of public water systems or plumbing in residential or other facilities providing drinking water. It prohibits the sale of pipes and plumbing fixtures that are not lead free, and the sale of solder or flux that is not lead free (unless it is properly labeled), with the exception of pipes used in manufacturing or industrial processing. (For purposes of Section 1417, the term “lead free” refers to solders and flux containing not more than 0.2% lead, and refers to pipes and pipe fittings containing not more than 8.0% lead.) The 1996 Amendments also required limits to be set on the amount of lead that may leach from new plumbing fixtures.

Section 1442 authorizes EPA to conduct research on the causes, treatment, control, and prevention of diseases resulting from contaminants in water. Section 1442(b) authorizes EPA to make grants and provide technical assistance to states or public water systems to assist them in responding to emergency situations; $35 million are authorized to be appropriated each year for this purpose. Section 1442(e) authorized $15 million for each year, through FY2003, for EPA to provide technical assistance to small public water systems and Indian Tribes to help them comply with SDWA regulations. Section 1458 directed EPA to conduct studies regarding subpopulations at greater risk, biological mechanisms, and waterborne disease occurrences.

Section 1447 provides that any federal agency having jurisdiction over federally owned and maintained public water systems must comply with all federal, state and local drinking water requirements as well as any underground injection control programs. The President may exempt a facility from compliance with a requirement if he determines it to be in the paramount interest of the country to do so. Exemptions last one year, but additional exemptions may be granted. Under Section 1457, EPA may use the estrogenic substances screening program created in the Food Quality Protection Act of 1996 (P.L. 104-170) to provide for testing of substances that may be found in drinking water, if the Administrator determines that a substantial population may be exposed to such substances.

Further Reading


Disclaimer: This article is taken wholly from, or contains information that was originally published by, the Congressional Research Service. Topic editors and authors for the Encyclopedia of Earth may have edited its content or added new information. The use of information from the Congressional Research Service should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.

Notes: The first version of this article was drawn from  the Congressional Research Service Report RL30798, Environmental Laws: Summaries of Major Statutes Administered by the Environmental Protection Agency by David M. Bearden, Claudia Copeland, Linda Luther, James E. McCarthy, Linda-Jo Schierow, and Mary Tiemann (October 8, 2010).



(2011). Safe Drinking Water Act, United States. Retrieved from


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