Region 8

Tribal Drinking Water Program

View the Region 8 Tribal Annual Compliance Report for Calendar Year 2013.

Administration of the Drinking Water Program on Tribal Lands

No Tribal Government in Region 8 has received "primacy"; i.e., the authority to administer and enforce their own drinking water programs, from the Environmental Protection Agency.

Therefore, EPA Region 8 directly implements the Safe Drinking Water Act within Tribal lands in Region 8. This covers any public water system with 15 or more service connections or that serves 25 or more persons for more than 60 days per year.

As of January 1, 2013, there are 134 active Tribal public water supply systems. Twenty-five percent get their water from surface water sources, while seventy-five percent get their water from ground water (wells). Sixty-eight percent of the systems serve populations of less than 500. Only one system serves a population of greater than 10,000. Each public water system is classified into one of three categories:

  • community public water system, i.e., towns, cities, mobile home parks, private subdivisions, etc., that have 15 or more service connections or serve 25 or more persons year round;
  • transient non-community public water systems, i.e., campgrounds, restaurants, highway rest areas, motels, hotels etc., that serve 25 or more different persons more than 60 days per year; and
  • non-transient non-community public water systems i.e., mining and industrial operations, schools, churches, etc., that serve the same 25 persons more than 60 days per year.

Approximately eighty-four percent of the Tribal systems are community systems, fewer than seven percent serve transient non-community systems, and the remaining ten percent serve non-transient non-community systems.

EPA works with various Federal agencies to coordinate activities to ensure that consumers are served safe drinking water. The Indian Health Service and the Bureau of Reclamation provide technical assistance as it pertains to the construction and the operation and maintenance of Tribal public water supply systems.

EPA also hires contractors to help provide training and technical assistance to operators of Tribal public water systems.

Public Water Supply System Operations

The National Primary Drinking Water Regulations require operators to routinely monitor for a variety of contaminants using approved sampling and analysis methods. The number of samples and the frequency at which samples must be collected depend on a variety of factors, including:

  • whether the drinking water source is surface or ground water,
  • the population served by the water system,
  • the classification of the water system,
  • prior compliance data, and
  • whether the system has received a monitoring waiver or exemption.


Violations occur when public water systems fail to monitor for the required contaminants or when the level of a contaminant detected in a sample exceeds the Drinking Water Standards and Regulations, or maximum contaminant level (MCL). Additional monitoring may also be required if a contaminant is detected above a threshold level that is below the MCL.