Contact Us

Regulations and Rules for Small Water Systems

Safe Drinking Water Act (SDWA)

Safe Drinking Water Act (SDWA)
The SDWA established national standards for drinking water quality. Its purpose is to protect public health. Later 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. It requires EPA to conduct cost/benefit analyses of new regulations and analyze the effect of the regulation on the capability of public water systems.
SDWA requirements related to public water system operations are:

  • National Primary Drinking Water Regulations (NPDWR): is designed to protect drinking water quality by limiting the levels of specific contaminants.
  • National Secondary Drinking Water Regulations: are non-enforceable guidelines for controlling contaminants that affect taste, color, and odor.
  • Contaminant Candidate List (CCL): is a published prioritized list that EPA is studying to decide whether regulations are needed. The contaminants are known or expected to occur in public water systems. They are currently unregulated.

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

  • Maximum Contaminant Level (MCL): are designed to protect drinking water quality by limiting 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): 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): 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 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). 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) have about one MCL violation for every 200,000 people served.

Top of page

Other Rules

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

Surface Water Treatment Rule –This rule improves drinking water quality and provides additional protection from disease-causing microorganisms and contaminants that can form during drinking water treatment.

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. These byproducts, if consumed in excess of EPA's standard over many years, may lead to increased health risks. The DBP rules require reduced levels of disinfectants and DPBs in drinking water supplies.

Wellhead Protection –Wellhead protection safeguards all or part of the area surrounding a well from which groundwater is drawn. The SDWA requires each state to develop and implement a wellhead protection plan. Despite the need for source water protection, just 28 percent of the smallest systems participate in source water or wellhead protection program. Some small systems lack technical and financial resources to develop and manage such programs.

Top of page

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. States exercise primary enforcement responsibility. States may grant a small system variance without EPA approval to public water systems serving 3,300 or fewer people. EPA approval must be obtained for variances for systems serving more than 3,300 people but fewer than 10,000 people.

In order to obtain a small system variance, it must be determined that the public water 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.

Top of page

Jump to main content.