An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

New and Revised Drinking Water Rules in Wyoming and Tribal Lands in EPA Region 8

The Environmental Protection Agency issues new rules or revises existing rules as new data are obtained regarding the risk from microbial or chemical contaminants in drinking water sources or due to treatment processes performed by drinking water systems. New rules or rule changes may pertain to information gathering, additional monitoring and reporting, or to drinking water maximum contaminant levels or treatment techniques.

A good explanation of this regulation revision process can be found on the Get Involved with EPA Regulations webpage. The public is provided an opportunity to comment during the time period posted in a proposed rule notice. contains Federal Register notices, support documents, and public comments for regulations the Agency publishes and various non-regulatory activities. You may search, download and print the documents, as well as submit comments online. Since this website covers public notices from all agencies, you may wish to limit your search to "drinking water".

You will find information on this page regarding EPA Region 8 plans for implementing new drinking water rules in Wyoming and on Tribal lands as they become available. You may also check the What's New page for recent activities in this regard.

There are several rules that are, or will be shortly, affecting public water supply system operations. Provided below is general information about these rules. Your system will be notified individually by EPA Region 8 regarding any specific actions, if any, you will need to take as a result of these new or revised rules.

Revised Total Coliform Rule (RTCR)

The Revised Total Coliform Rule (RTCR) became effective April 1, 2016 and its requirements now apply to all public water systems. The RTCR aims to increase public health protection through the reduction of potential pathways for fecal contamination in the distribution system of a public water system (PWS). Be sure to visit the RTCR Overview page for more details on any changes to monitoring frequency, system requirements after positive results and start-up procedures for seasonal systems.

Lead-Free Act - What Does It Mean For You?

The SDWA Section 1417 Prohibition on Use and Introduction into Commerce of Lead, Solder and Flux was amended January 4, 2011.
- The amendments are effective 3 years later or January 4, 2014.
- The current lead free requirements are in 40 CFR 141.43. EPA’s plans to revise 141.43 are tied to the Lead and Copper Long-Term Revisions, however the regulatory revisions will not be promulgated prior to the January 2014 effective date. Interim guidance is being discussed.

New products - existing stock cannot be used starting 1/4/14:
Any back inventory that does not meet the 0.25% lead free calculation (performed by manufacturers or third party) cannot be installed beginning January 4, 2014. This stock can only be used for nonpotable uses.
Also products that do not meet the 0.25% lead free calculation cannot be introduced into commerce after January 4, 2014 for potable uses.

Repair and returning products to service - potential approaches yet to be resolved:
1417(a)(1)(A) Prohibits the use of items that are not lead free “in the installation or repair” of any PWS or any plumbing in a residential or non-residential facility providing water for human consumption.
Potential approaches:
- entire unit would need to meet the 0.25% lead content
- only components being replaced would need to meet the 0.24% lead content.

For additional information, please see Use of Lead Free Pipes, Fittings, Fixtures, Solder and Flux for Drinking Water.

Stage 2 Disinfection Byproducts (Total TTHM and HAA5s) - IDSE Requirements

The Stage 2 DBP Rule requirements apply to community and nontransient noncommunity water systems that add and/or deliver water that is treated with a primary or residual chemical disinfectant other than ultraviolet light. Our office has contacted each system covered by this rule regarding any actions needed.

Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR or LT2)

The purpose of the Long Term 2 Enhanced Surface Water Treatment Rule is to reduce disease incidence associated with Cryptosporidium and other pathogenic microorganisms in your drinking water. The rule applies to all public water systems that use surface water or ground water that is under the direct influence of surface water, and the rule may require source water monitoring. Our office has contacted each system covered by this rule regarding actions required by the rule.

Ground Water Rule

The Ground Water Rule will apply to public water systems that serve ground water. The rule also applies to any system that mixes surface and ground water if the ground water is added directly to the distribution system and provided to consumers without treatment. The purpose of the rule is to provide for increased protection against microbial pathogens in public water systems that use ground water sources. EPA is particularly concerned about ground water systems that are susceptible to fecal contamination since disease-causing pathogens may be found in fecal contamination. Our office will be contacting public water supply systems affected by this rule in the future specifying whether or not (and when) your system needs to take any action.