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EPA's Role in Safe Drinking Water on Tribal Lands


SDWA Compliance by Tribal Public Water Systems

National Primary Drinking Water Regulations

National Primary Drinking Water Regulations (NPDWRs) are legally enforceable standards and requirements. NPDWRs protect public health by limiting the levels of contaminants in drinking water. These regulations apply to all public water systems (PWSs).

It is the responsibility of tribal governments and tribal utilities to maintain and operate the system in compliance with EPA’s NPDWRs and other program requirements.

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Compiling and Analyzing Drinking Water Compliance Data

Under the Tribal Public Water System Supervision (PWSS) program EPA collects drinking water compliance data. The data is analyzed to determine compliance with SWDA in Indian country.

EPA stores this information in the Safe Drinking Water Information System (SDWIS). SDWIS contains information about public water systems and their violations of EPA's drinking water regulations. EPA gauges compliance with the National Primary Drinking Water Regulations through a metric that tracks the percentage of the CWSs that have met all applicable health-based drinking water standards in the preceding year.

Submission Year # of Violations # of Systems in Violation Total Pop Served in Violation # of Systems Total Pop Served System %
2018 219 92 114,208 708 1,0056,674 87.5

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Conducting Sanitary Surveys and Source Water Assessments

EPA performs Sanitary Surveys to assess a PWSs ability to provide safe drinking water to the community. A sanitary survey is an on-site review of a public water system’s source, facilities, equipment, operation and maintenance. Surveys identify sanitary deficiencies and technical needs; assess a system’s capacity and structural integrity.

The following eight areas are evaluated for compliance:

  1. Water sources
  2. Treatment
  3. Distribution systems
  4. Finished water storage
  5. Pumps, pump facilities and controls
  6. Monitoring, reporting and data verification
  7. Water system management and operations
  8. Operator compliance with EPA requirements

There is a federal mandate to perform sanitary surveys for all public drinking water systems. EPA performs the surveys on tribal lands where EPA is the primacy agency. Most importantly, these surveys provide an opportunity for EPA to work with the system to lower the risk of contamination and waterborne disease.

Source water assessments are another integral part of ensuring that a water system is providing safe drinking water to the community. These assessments are different for each system. They analyze existing and potential threats to the quality of the PWS and identify protection measures to address these them.

EPA may perform an assessment or help establish Source Water Assessment Programs (SWAPs) for a tribal PWS.

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