Environmental Policy & Guidance

Safe Drinking Water Act

Purpose and Organization

In 1974 Congress enacted the Safe Drinking Water Act (SDWA) to manage potential contamination threats to ground water. The act instructed EPA to establish a national program to prevent underground injections of contaminated fluids that would endanger drinking water sources. Primary drinking water standards promulgated under the SDWA apply to drinking water "at the tap" as delivered by public water supply systems. As such, the standards apply directly to those DOE facilities that meet the definition of a public water supply system (e.g., the DOE Oak Ridge Reservation is a public water supply system because it provides water to the City of Oak Ridge).

Of equal significance to DOE is that the drinking water standards are used to determine ground water protection regulations under a number of other statutes (e.g., RCRA). Therefore, many of the SDWA requirements apply to DOE activities, especially cleanup of contaminated sites and storage and disposal of materials containing radionuclides, inorganic chemicals, organic chemicals, and hazardous wastes.

Section 1447 of the SDWA states that each federal agency having jurisdiction over a federally owned or maintained public water system must comply with all federal, state, and local requirements; administrative authorities; and processes and sanctions regarding the provision of safe drinking water. Sections 1412, 1414, and 1445(a) of the SDWA authorize drinking water regulations and specific operating procedures for public water systems.

Public water systems, as defined in 40 CFR Part 141.2, provide piped water for human consumption and have at least 15 connections or regularly serve at least 25 people. Public water systems are either:

• community water systems: public water systems that serve at least 15 connections used by year-round residents or regularly serve at least 25 year-round residents;
• non-transient non-community water systems: public water systems that are not community water systems but that regularly serve at least the same 25 people for six months per year (e.g., workplaces and hospitals); or
• non-community water systems: all other water systems (e.g., campgrounds and gas stations).

National Primary Drinking Water Regulations

The SDWA requires EPA to establish National Primary Drinking Water Regulations (NPDWRs) for contaminants that may cause adverse public health effects. The regulations include both mandatory levels [Maximum Contaminant Levels (MCLs)] and nonenforceable health goals [Maximum Contaminant Level Goals (MCLGs)] for each included contaminant. MCLGs have extra significance because they can be used under Superfund as Applicable or Relevant and Appropriate Requirements (ARARs) in NPL cleanups.

The 1986 SDWA amendments required EPA to apply future NPDWRs to both community and non-transient non-community water systems when it evaluated and revised current regulations. The first case in which this was applied was the final rule on July 8, 1987 (52 FR 25690). At that time NPDWRs were promulgated for certain synthetic volatile organic compounds (VOCs) and applied to non-transient non-community water systems as well as community water systems. This rulemaking also clarified that non-transient non-community water systems were not subject to MCLs that were promulgated before July 8, 1987.

Future NPDWR standards will apply to non-transient non-community water systems because of concern for the long-term exposure of a stable population. It is important to note that EPA's decision to apply future NPDWRs to non-transient non-community water systems may have a significant impact on those DOE facilities that operate their own drinking water systems.

Underground Injection Control

Another provision of the SDWA established programs to prevent contamination of underground sources of drinking water by underground injection of contaminated fluids. Prohibitions mandated by the Hazardous and Solid Waste Amendments (HSWA) to the Resource Conservation and Recovery Act (RCRA) on the underground injection of hazardous wastes were promulgated on July 26, 1988 (53 FR 28118). This rule amended existing Underground Injection Control (UIC) regulations as they pertained to hazardous waste injection. It also codified at 40 CFR Part 148 the applicable sections of 40 CFR Part 268, EPA's regulatory framework for implementing the land disposal restrictions. The direct impact of UIC regulations on DOE has diminished with the cessation of the hydrofracture project in Oak Ridge, but the requirements are still important in governing the plugging and abandonment of wells used in some past practices.

States have primary enforcement authority for the SDWA, although if states do not properly enforce SDWA requirements, EPA will assume the authority to do so. The federal government provides funds to assist in state enforcement of the Act. In certain circumstances states may consider cost, benefits, alternatives, public interest, and the protection of human health and the environment in granting variances and exemptions from the national regulation. For example, many of the regulations affecting ground water provide for exemptions, variances, or alternate concentration limits. Thus, if DOE believes that direct application of a drinking water standard for ground water protection is not justified on the basis of expected risk to the public at a specific site, DOE may request an exemption, variance, or alternate concentration limit.

SDWA Reauthorization

The SDWA amendments were signed into law by President Clinton on August 6, 1996 (Pub. L. 104-182). A brief summary of these amendments will be provided as soon as the new amendments have been reviewed to assess their impact on DOE. To obtain a copy of the new law, please go to Thomas, Legislative Information on the Internet, select "List of Public Laws" under "Browse" and go to the appropriate public law number.

Regulations implementing the SDWA are found in Title 40 of the CFR, Chapter I, Subchapter D. Parts 124 and 141 through 148 of Subchapter D contain regulations important to DOE.