Regulations

Safe Drinking Water Act (SDWA)

Congress passed the Safe Drinking Water Act (SDWA) in 1974. Its intent is to protect public health by regulating our nation's public drinking water supply. The SDWA established national enforceable standards for drinking water quality and requires water suppliers to monitor their water to ensure it meets national standards.

The act was amended in 1986 and again in 1996. The 1996 amendments changed the emphasis of the law from drinking water treatment to contaminant prevention through source water protection and enhanced water system management. These amendments also allowed for flexibility of regulations and monitoring for small systems, and required EPA to conduct cost/benefit analyses of new regulations and analyze the likely effect of the regulation on the viability of public water systems.

SDWA regulatory provisions related to public water system operations are:

• National Primary Drinking Water Regulations (NPDWR) – Designed to protect drinking water quality by limiting the levels of specific contaminants, this provision established Maximum Contaminant Level Goals and two types of numeric standards: Maximum Contaminant Levels (enforceable) and Maximum Contaminant Level Goals (non-enforceable).
• National Secondary Drinking Water Regulations – These standards are non-enforceable guidelines for controlling contaminants in drinking water for aesthetic considerations, such as taste, color, and odor.
• Contaminant Candidate List (CCL) – This is a published list of contaminants that are not regulated by any NPDWR provisions, are anticipated or known to occur in public water systems, and may later require regulation under the SDWA. The CCL is used to determine contaminants for priority drinking water research, occurrence monitoring, and guidance development (e.g., health advisories).

Violations of the SDWA by drinking water systems fall into three major categories:

• Maximum contaminant level (MCL) – Established by the SDWA, MCLs are designed to protect drinking water quality by limiting, in our drinking water, the levels of specific contaminants that can adversely affect public health. A violation occurs when the level of a contaminant in treated water is above EPA or the state's legal limit.
• Treatment technique (TT) – A treatment technique is a required process intended to reduce the level of a contaminant in drinking water. These techniques may include disinfection, filtration, and aeration. A violation occurs when a water system fails to treat its water in the way EPA prescribes.
• Monitoring or reporting (M/R) – These are record-keeping requirements. A violation occurs when a system fails to test its water for certain contaminants or fails to report test results on time.

A breakdown of violations by small systems shows that, by far, most violations (86 percent) are breaches in M/R requirements, followed by MCL violations (8 percent), and TT violations (1.5 percent).

Furthermore, very small systems (those serving 25 to 500 people) have the largest number of violations (mostly M/R violations), and they experience one MCL violation for every 80 people served—this is the highest ratio of all system service population categories. By comparison, very large systems (those serving more than 100,000 people) experience about one MCL violation for every 200,000 people served.

The application of remote monitoring and control equipment to operate, monitor, and control small systems from a central location is believed to be one mechanism that can reduce MCL and M/R violations.

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Other Rules

Ground Water Rule – This rule affects small systems that use groundwater as a water source. The rule calls for periodic sanitary surveys, which would uncover deficiencies that need to be corrected and identify systems that may be prone to fecal contamination or need to implement a particular treatment. The rule also developed risk-based rule requirements that minimize the time and financial burden on small systems.

Surface Water Treatment Rule – The regulations governing this rule are meant to improve control of microbial contaminants and prevent increases in microbial risk while systems implement control for disinfection by-products (DBPs).

Stage 1 and Stage 2 Disinfection By-Products Rules – A DBP is a compound formed by the reaction of a disinfectant (such as chlorine) with naturally occurring organic material in the water supply. Many DBPs are suspected of causing cancer, reproductive, and developmental problems in humans. The DBP rules require reduced levels of disinfectants and DPBs in drinking water supplies.

Source Water Assessments

Our drinking water comes from source water—rivers, lakes, aquifers, etc. Source water is surface and groundwater in its natural state, prior to any treatment for drinking. Surface water is vulnerable to contamination from surface runoff and groundwater infiltration. Ground water is vulnerable to contamination through infiltration from the surface, incursion of contaminants from underground storage tanks, septic systems, injection wells, and by naturally occurring substances in the soil or rock through which the water flows.

Prior to treatment, source water may contain:

• Microbial contaminants – viruses and bacteria primarily from human and animal wastes
• Inorganic contaminants – salts and metals
• Pesticides and herbicides
• Organic contaminants, including synthetic and volatile organic chemicals
• Radioactive contaminants

Source water that's contaminated can be very costly to a community and state. In the long term, it is more economical to protect source water from contamination than it is to treat contaminated water or find a new source. Source water protection is the first line of defense in preventing waterborne illnesses.

The SDWA requires each state to develop and implement a source water assessment program. These assessments identify the area of land that most directly contributes the raw water used for drinking water and identifies the major potential sources of contamination to drinking water supplies. The information gathered can then be used to determine how susceptible the water system is to contamination.

Wellhead Protection – Wellhead protection is simply protection of all or part of the area surrounding a well from which groundwater is drawn. The 1986 amendments to the SDWA require each state to develop and implement a wellhead protection plan to address such areas as the risk associated with contaminant sources within each wellhead area; management approaches; and contingency plans.

Despite the obvious need for source water protection, just 28 percent of the smallest systems and only 50 percent of systems serving 10,000 or more persons participate in some form of source water or wellhead protection program. Some small systems are less likely to adopt wellhead protection or source water protection programs because of the lack of technical and financial resources to implement and manage such programs.

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Variances and Exemptions

Public water systems can request variances or exemptions, which allow systems to be relieved of their obligation to meet a specific drinking water standard while continuing to protect public health to the maximum extent possible.

States exercising primary enforcement responsibility may grant a small system variance without EPA approval to public water systems serving 3,300 or fewer people. However, EPA approval must be obtained for variances for systems serving more than 3,300 people but fewer than 10,000 people. A small system variance is not available for microbial contaminants or for contaminants regulated prior to 1986. In order to obtain a small system variance, it must be determined that the system cannot afford to comply with the NPDWR.

Exemptions are intended to provide compliance flexibility. States or EPA may grant temporary exemptions from a standard if, due to certain compelling factors (including cost), a system cannot comply on time. To grant an exemption, the state or EPA must determine whether management or restructuring changes or both would improve water quality or achieve compliance.