42 U.S.C. § 300g–1 — National drinking water regulations

(a) National primary drinking water regulations; maximum contaminant level goals Any interim or revised drinking water rule the EPA had already issued before June 19, 1986, automatically counted as an official national primary drinking water regulation. Those older rules didn't have to meet the newer cost-benefit standards described later in this section unless the EPA later changed the contaminant limit. Any "recommended maximum contaminant level" published before June 19, 1986, became a "maximum contaminant level goal" instead. From then on, whenever the EPA proposes or finalizes a legal limit for a contaminant, it must propose or publish the health goal for that same contaminant at the same time. That double-publishing rule does not apply to the older recommended levels published before June 19, 1986. (b) Standards This is the core of the section. It covers how the EPA picks contaminants, sets goals and limits, and follows special rules for certain substances. Identifying contaminants to regulate. The EPA must set a health goal and a legal limit for a contaminant if three things are true: it may harm people's health; it occurs, or is substantially likely to occur, in public water systems at levels of public health concern; and regulating it would, in the EPA's own judgment, meaningfully reduce health risk. Every five years, starting within 18 months after August 6, 1996, the EPA must publish a list of unregulated contaminants that might need regulation, after consulting scientists (including its Science Advisory Board), taking public comment, and considering its occurrence database. The list must include, but is not limited to, hazardous substances covered by the federal cleanup law and pesticides registered under federal pesticide law. The EPA's choice of which contaminants to put on this list cannot be challenged in court. Every five years, the EPA must decide whether to regulate at least five contaminants from that list, based on the same three-part test above and the best available public health information, including its occurrence database. The EPA may also decide to regulate a contaminant not on the list, as long as it meets that same test. A decision NOT to regulate a contaminant counts as a final government action and can be challenged in court. Each of these regulate-or-not decisions is published for public comment when it is made. When picking which unregulated contaminants to study first, the EPA must pick the ones that raise the biggest public health concerns, including extra harm to groups like infants, children, pregnant women, the elderly, and people with serious illness, who may be at greater risk than the general public. For an urgent public health threat, the EPA may issue a temporary ("interim") rule for a contaminant right away, without first completing the normal regulate-or-not determination or the cost-benefit analysis described below, but only after consulting the Secretary of Health and Human Services (through the CDC or the National Institutes of Health) and responding in writing to their comments. Within three years of that emergency rule, the EPA must complete the missing determination and analysis, and it must reissue or update the rule within five years. Once the EPA decides to regulate a contaminant, it must propose the health goal and legal limit within 24 months of that decision (it may publish the proposal at the same time as the decision to regulate). The final health goal and legal limit must follow within 18 months after the proposal. The EPA can push that final deadline back by up to nine months if it announces the extension in the Federal Register. For contaminants the EPA isn't regulating, it may still publish health advisories (which are not binding rules) or take other appropriate action. Schedules for older, already-listed contaminants. For contaminants already listed in the EPA's 1982 and 1983 proposed-rule notices, the EPA had to publish health goals and legal limits for at least 9 of them within one year of June 19, 1986, at least 40 more within two years, and the rest within three years. If the EPA finds a different contaminant whose regulation would better protect public health than one of those originally listed, it may regulate that substitute instead — up to seven substitutions are allowed — following the same schedule as the contaminant it replaces. The EPA also had to issue, on a set 1994 schedule, four specific rules on disinfectants and disinfection byproducts (an Interim and a Final Enhanced Surface Water Treatment Rule, and a Stage I and Stage II Disinfectants and Disinfection Byproducts Rule); if any one is delayed, the remaining rules must still be finished as quickly as practicable, without slipping further behind that schedule. Using science responsibly. Whenever a rule under this section relies on science, the EPA must use the best available peer-reviewed science and data collected by accepted or best-available methods, where the data's reliability and the nature of the decision justify using it. When explaining a rule to the public, the EPA must, as far as practical, clearly describe: which groups of people were covered by any health-effects estimate; the expected or "central" risk estimate for those groups; the high-end and low-end risk estimates; any major uncertainty in the assessment and what further study could resolve it; and peer-reviewed studies that support, are directly relevant to, or contradict the estimate, explaining how conflicting data were reconciled. Weighing health risks against costs. Before proposing a numeric legal limit for a contaminant, the EPA must publish, and take public comment on, an analysis covering: (I) health benefits it can show, with a factual basis in the record, are likely from treatment to meet the limit; (II) extra health benefits likely from cutting related, "co-occurring" contaminants — but not benefits from complying with other rules; (III) costs likely from meeting the limit, including monitoring and treatment costs — again excluding costs from complying with other rules; (IV) the added costs and benefits of each alternative limit considered; (V) the effect on vulnerable groups such as infants, children, pregnant women, the elderly, and the chronically ill; (VI) any new health risk that compliance itself might create, including from co-occurring contaminants; and (VII) other relevant factors, such as the quality of the data and the uncertainty in the analysis. If the EPA instead requires a treatment technique rather than a numeric limit, it must publish and take comment on a similar cost-and-benefit analysis for that technique and any alternatives considered. The EPA may develop valid methods for measuring these benefits, including how much people are willing to pay to reduce health risk from contaminants. Congress authorized $35,000,000 a year from 1996 through 2003 for the EPA's Office of Ground Water and Drinking Water to fund studies supporting this kind of analysis. Setting the goals and limits. A health goal (maximum contaminant level goal) must be set at the level where science shows no known or expected harm to health, with an adequate margin of safety — cost is not a factor here. The legal limit (maximum contaminant level) must then be set as close to that health goal as is "feasible," except where the special rules described in the next two paragraphs apply. When the EPA proposes a legal limit, it must publish a determination on whether the benefits justify the costs, based on the cost-benefit analysis described above. "Feasible" means achievable using the best technology, treatment technique, or other means the EPA finds actually available in the field — not just in a laboratory — taking cost into account. For synthetic organic chemicals specifically, granular activated carbon always counts as feasible, and any other technology used for those chemicals must control them at least as well as granular activated carbon does. Listing the technology that works. Every rule that sets a legal limit must list the technologies, treatment techniques, or other means the EPA has found feasible for meeting it — but the rule cannot force a water system to use one specific listed method. The list must include options the EPA finds affordable, in consultation with the states, for small systems in three size categories: those serving more than 3,300 but not more than 10,000 people; more than 500 but not more than 3,300; and more than 25 but not more than 500 — including packaged, modular, point-of-entry, and point-of-use treatment units. Any point-of-entry or point-of-use unit must be owned, controlled, and maintained by the water system (or someone under contract to it), so proper operation is assured, and must have mechanical warnings that automatically alert customers to problems. The EPA cannot list any point-of-use technology to meet a limit or treatment-technique requirement for a microbial contaminant or its indicator. If a national standards organization has certified a type of point-of-entry or point-of-use unit, individual units of that type qualify only if independently certified to that standard. In listing technologies this way, the EPA must consider the quality of the source water being treated. Within two years of August 6, 1996, and after consulting the states, the EPA had to issue a list of technologies achieving compliance, for each of the three small-system size categories, for every rule promulgated before June 19, 1986. The EPA may add newly available or innovative technologies to the list at any time for those small-system categories. Within one year of August 6, 1996, the EPA also had to list technologies meeting the Surface Water Treatment Rule for those same three size categories. Adjusting for other health risks. Even though the "feasible" limit is normally required, the EPA may set a different limit if the technology needed to reach the feasible level would itself increase overall health risk from drinking water — for example, by raising the concentration of other contaminants, or by interfering with treatment used to comply with other national rules. If the EPA does this, the limit (or required treatment technique) must be set to minimize overall health risk by balancing the risk from the contaminant against the risk from other affected contaminants, and the combination required still cannot be stricter than what's feasible. Adjusting for cost-justification. If, based on the cost-benefit analysis described above, the EPA determines that a "feasible" limit's costs would not be justified by its benefits, the EPA may instead, after notice and public comment, promulgate a limit that maximizes health-risk-reduction benefits at a cost that IS justified by those benefits. But the EPA cannot use this option if the benefits to (i) people served by large water systems, plus (ii) people unlikely — based on state-provided information — to get a small-system variance, would themselves already justify the costs of the standard "feasible" rule; that exception to the exception doesn't apply if the contaminant is found almost only in small systems eligible for a small-system variance. This cost-justification option cannot be used to set limits in the Stage I or Stage II disinfectant/disinfection-byproduct rules, or to set any limit or treatment-technique requirement for cryptosporidium; it may, however, be used for the ground-water disinfection rules required later in this section. A court reviewing the EPA's cost-benefit determination can only do so as part of reviewing the final rule that was based on it, and can overturn the determination only if it finds it "arbitrary and capricious." Treatment techniques instead of numeric limits. If the EPA finds it is not economically or technologically feasible to measure a contaminant's exact level, it may require a treatment technique instead of setting a numeric limit, identifying the technique(s) that would prevent harm to health as much as feasible; the EPA may grant a variance from a specified technique under the variance rules elsewhere in this subchapter. Any deadline that applies to a numeric-limit rule applies the same way to a treatment-technique rule. Within 18 months of June 19, 1986, the EPA had to propose and finalize rules setting criteria for when public water systems supplied by surface water must filter (including coagulation and sedimentation), considering source-water quality, watershed protection, disinfection, storage time, and other health-related factors. Instead of the normal variance process, the EPA sets procedures for states to decide which of their surface-water systems must filter; states may require systems to supply supporting studies or information, must give notice and a public hearing before deciding, and — if filtration is required — must set a compliance schedule requiring the system to comply within 18 months of that determination. States with primary enforcement responsibility had 18 months, after the EPA set the filtration criteria and procedures, to adopt matching state regulations, and then 12 more months to decide about filtration for every surface-water system in the state. If a state lacks primary enforcement responsibility, the EPA makes these filtration decisions itself, and any resulting filtration requirement or schedule is treated as if it were part of a national primary drinking water regulation. As a further alternative, a state with primary enforcement responsibility may, case by case and after notice and public comment, let a system with an uninhabited, undeveloped, single-owner watershed it fully controls access to use non-filtration treatment requirements instead of filtering, if the state (and the EPA) determine that approach removes or inactivates disease-causing organisms at least as well as filtration combined with chlorine disinfection would. Disinfection. Starting three years after August 6, 1996, but no later than when the EPA finalizes the Stage II disinfectant/disinfection-byproduct rule, the EPA must also promulgate a national rule requiring disinfection as a treatment technique for all public water systems, including surface-water systems and, as needed, ground-water systems. After consulting the states, the EPA must, as part of that rule, set criteria that it (or a state with primary enforcement responsibility) uses to decide whether a particular ground-water system must disinfect. The EPA must simultaneously issue criteria for granting variances from that disinfection requirement. When carrying out related technical-assistance provisions, the EPA or the delegated state should give special consideration to helping small public water systems comply. Review and revision. The EPA must review, and revise as appropriate, every national primary drinking water regulation at least once every six years. Any revision must go through the same process as the original rule, except that a revision can only maintain or strengthen health protection — it can never weaken it. Effective date. A new or amended national primary drinking water regulation takes effect three years after the EPA promulgates it, unless the EPA decides an earlier date is practicable — except that the EPA, or a state (for an individual system), may allow up to two additional years if extra time is genuinely needed for capital improvements. No unrelated additives. No national primary drinking water regulation may require adding any substance for general preventive-health-care purposes that is unrelated to contamination of the drinking water itself. Arsenic. Despite the general deadlines above, the EPA had to follow a specific arsenic schedule: develop, within 180 days of August 6, 1996, a comprehensive study plan to reduce uncertainty about health risks from low-level arsenic exposure, consulting the National Academy of Sciences, other federal agencies, and interested public and private groups; it could use cooperative agreements with other agencies and governments to carry out that study; it had to propose an arsenic rule no later than January 1, 2000, and finalize it, after notice and public comment, no later than January 1, 2001. Congress authorized $2,500,000 per year from 1997 through 2000 for these arsenic studies. Sulfate. Before promulgating a sulfate rule, the EPA and the Director of the CDC had to jointly conduct an additional study to establish a reliable dose-response relationship for sulfate's health effects, including on groups like infants and travelers who may face greater risk, using the best available peer-reviewed science, in consultation with interested states, and completed no later than 30 months after August 6, 1996. Sulfate had to be included among the five-or-more contaminants for which the EPA makes a regulate-or-not determination within five years of August 6, 1996. Despite the normal scheduling deadlines, the EPA may, under this section's authority and after notice and public comment, promulgate a final sulfate rule that includes requirements for public notification and options for alternative water supplies for at-risk populations, as a way of complying instead of requiring the best available treatment technology. Radon in drinking water. The EPA had to withdraw any radon rule it had proposed before August 6, 1996, and instead propose and promulgate a new radon regulation under this amended section. Before proposing that new rule, the EPA had to arrange for the National Academy of Sciences to prepare a peer-reviewed risk assessment for radon in drinking water, using the best available science, considering every risk from radon exposure through drinking water and studies on health effects at levels likely from residential exposure. The EPA also had to arrange for the Academy to assess the health-risk-reduction benefits of various measures to reduce radon in indoor air (which could be combined with the risk assessment) and to use that assessment in preparing guidance and approving state programs described below; if the Academy declined, the EPA had to contract with another independent scientific organization instead. Within 30 months of August 6, 1996, the EPA had to publish, and take public comment on, a health-risk-reduction-and-cost analysis (meeting the same requirements described above) for potential radon limits, and had to respond to significant public comments in the preamble of the proposed rule. Within 36 months of August 6, 1996, the EPA had to propose a health goal and legal limit for radon; within 12 months after that proposal, it had to finalize both, based on the risk assessment and the cost analysis, and taking into account the costs and benefits of other programs that address radon from sources other than drinking water. If the final radon limit turns out stricter than necessary to bring the drinking-water contribution to indoor radon down to a level equal to the national average concentration of radon in outdoor air, the EPA must, at the same time, promulgate a less-strict "alternative" limit matching that outdoor-air benchmark, and — after notice, public comment, and consultation with the states — publish guidelines for state multimedia radon programs, including criteria for combining several mitigation strategies, drawing on data from existing radon programs and the Academy's assessment. A state may submit a multimedia program to reduce indoor radon from various sources for EPA approval; if approved after notice and public comment, water systems in that state may follow the easier alternative limit instead of the standard limit set under the final rule. These state programs may use public education, testing, training, technical assistance, grants, loans, incentives, or other regulatory or non-regulatory measures, and the EPA evaluates their effectiveness using the Academy's assessment and the EPA's own guidelines. The EPA must approve a state program if its expected health-risk-reduction benefits equal or exceed what full compliance with the standard limit would achieve, must approve or disapprove within 180 days of receiving it (no decision within that time counts as approval), and a disapproved program may be revised and resubmitted. The EPA must review each approved program at least every five years and may withdraw approval — after written notice to the state and a chance to fix any problem — if the program no longer qualifies. If a state's governor commits, within 90 days after the alternative limit is promulgated, to developing such a program, the EPA must extend that state's compliance deadline for the radon rule by 18 months. If a state chooses not to submit a program, or its program is disapproved, an individual public water system in that state may submit its own program for EPA approval under the same criteria and process that would apply to a state program. Recycling of filter backwash water. The EPA must promulgate a regulation governing how a public water system recycles the water used to backwash its filters back into the treatment process, no later than four years after August 6, 1996, unless the EPA's separate Enhanced Surface Water Treatment Rule already addresses this by that date. Variance technologies. Whenever the EPA promulgates a new legal limit, it must, at the same time, issue guidance or regulations identifying the best treatment technologies, treatment techniques, or other means ("variance technology") that it finds — after examining field, not just laboratory, performance — are available and affordable, in consultation with the states, for the same three small-system size categories described above, when no size-appropriate technology is already listed for meeting the limit, considering the source water's quality. A variance technology does not have to fully achieve the legal limit, but must achieve the maximum reduction or inactivation that is affordable given the system's size and source-water quality; guidance cannot require a technology from a specific manufacturer or brand. The EPA may not identify a variance technology unless it has determined — considering source-water quality and the technology's expected useful life — that it protects public health. In the guidance, the EPA must disclose the assumptions supporting that public-health determination, disclose the assumptions used to determine affordability (considering how many people the system serves), and provide as much reliable information as practical on performance, effectiveness, limitations, cost, and other relevant factors, including whether the technology works on both surface and underground source water. Within two years of August 6, 1996, and after consulting the states, the EPA had to issue this guidance for every rule promulgated before that date for which a small-system variance is available under this subchapter; the EPA may add newly available or innovative variance technologies at any time, must review the identified variance technologies at least every seven years (or sooner, given a well-supported petition), and must issue revised guidance when a new technology becomes available that achieves an equal or greater reduction than the ones already listed. A water system already using a listed variance technology does not have to replace it during its useful life just because a more efficient variance technology gets listed later. (c) Secondary regulations; publication of proposed regulations; promulgation; amendments The EPA had to publish proposed national secondary drinking water regulations — rules addressing things like taste, odor, and appearance rather than direct health effects — within 270 days of December 16, 1974, and had to finalize them, with whatever modifications it found appropriate, within 90 days after publishing the proposal. These secondary regulations may be amended over time. (d) Regulations; public hearings; administrative consultations Regulations under this section must follow the normal federal rulemaking process, except that the EPA must also offer an opportunity for a public hearing before finalizing them. While proposing and finalizing these regulations, the EPA must consult with the Secretary of Health and Human Services and with the National Drinking Water Advisory Council. (e) Science Advisory Board comments Before proposing a health goal and legal limit for a contaminant, the EPA must ask its Science Advisory Board for comments. The Board should respond, as it sees fit, within whatever time period applies to finalizing that particular rule. Under no circumstances may this review step be used to delay final promulgation of a national primary drinking water standard.