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Drinking Water Regulations Guidance for Systems in Wyoming and on Tribal Lands in EPA Region 8

National Primary Drinking Water Regulations are found in the US Code of Federal Regulations - Title 40 Part 141 . These regulations, or rules, spell out the requirements that systems must follow when in operation. If your system fails to comply with one or more regulations, it is considered to be in violation of that regulation(s). USEPA will usually notify you regarding violations of the drinking water regulations. That notification will describe the instance of violation and what you must do to return to compliance. We recommend that you consult with the Region 8 Office regarding actions to return to compliance and how best to provide information that will document your return to compliance. Your system may be held accountable to fines and criminal penalties.

The National Primary Drinking Water Regulations include standards for the maximum contaminant levels for microbiological and chemical maximum contaminant levels (MCLs), standards for treatment techniques (TTs), and for public notification and reporting to consumers and/or to the USEPA Region 8. You may read about each of these rules in more detail at the EPA Drinking Water Regulations webpage. Additional information is also available on the Safe Drinking Water Act webpage.

In certain cases, Region 8 provides variances or exemptions to certain drinking water rules. If your system has received a variance or exemption, you should find a letter from USEPA Region 8 providing the conditions of the variance or exemption. Please consult our EPA Region 8 Drinking Water Program Contact List and contact the appropriate rule manager should you have any questions.

Variances allow eligible systems to provide drinking water that does not comply with a National Primary Drinking Water Regulation (NPDWR) on the condition that a system installs a certain technology and the quality of the drinking water is still protective of public health. Region 8 sets forth the amount of time and the conditions of the variance in a letter to the system. General variances may be given to systems that are not able to comply with a NPDWR due to their source water quality. Small system waivers may be given to systems serving 3,300 persons or fewer if the system shows it cannot afford to comply with the NPDWR.

Exemptions do not release a water system from complying with a NPDWR, but does give the system additional time to do so. Initial exemptions cannot be for more than three years. If your system has received a small system variance, it is not also eligible for an exemption. If your system has received an exemption, it is usually not eligible for a variance.

For more information, please consult US EPA's Variances and Exceptions: A Quick Reference Guide.