Jun 06, 2017

Setting the Limits

State MCLs bring attention to federally regulated & unregulated contaminants

WQA held its annual DC Fly-In Day and partnered with the National Ground Water Assn. and the Irrigation Assn. to host the Water Resources Congressional Conference. On Capitol Hill, WQA members urged Congress to reach out when reviewing legislation for drinking water and contact the association whenever there is a water issue in their states.

Traditionally, the U.S. Environmental Protection Agency (EPA) selects unregulated contaminants and sends them through a process to determine how they should be regulated. EPA requires all public water systems to have adequate treatment and testing procedures for contaminants with a maximum contaminant level (MCL) or treatment technique. If a contaminant is detected above the MCL, it triggers further action, including public notification. Establishing an MCL takes years of data gathering and research.

States can amend federal MCLs to make them more stringent or adopt their own MCLs for unregulated contaminants. These are enforceable limits for all public water systems within the state. For example, California set a state MCL for total chromium in 1977 of 50 µg/L. Afterward, EPA adopted the same MCL; however, in 1991 the federal MCL was raised to 100 µg/L. California did not amend the state level to reflect EPA’s change. Additionally, EPA has not created a federal MCL for chromium-6, but in 2014 the California Department of Health Services developed a chromium-6 state MCL of 10 µg/L.

Amending MCLs

This year, heightened attention to lead and unregulated contaminants like perfluorinated compounds encouraged multiple states to develop their own MCLs.

The federal maximum contaminant level goal (MCLG) for lead is zero. These goals only take human health into consideration. The enforceable MCL—15 ppb for lead—looks at treatment and economic feasibility. This year, Michigan and Virginia introduced legislation to address lead in drinking water. Michigan Senate Bill 63 and Virginia House Bill 2384 propose to lower the MCL to 10 ppb on Dec. 31, 2017, and to 5 ppb on Jan. 1, 2021. These limits would only be enforceable in those states.

Addressing Federally Unregulated Contaminants

New York and Pennsylvania are pursuing MCLs for perfluorinated compounds, which remain unregulated by EPA. In 2016, EPA released a lifetime health advisory for them, but not an enforceable limit. New York Senate Bill 4386 proposes the state Commission of Health examine perfluoroalkyl carboxylic acids and perfluoroalkyl sulfonic acids to establish an MCL for drinking water. Pennsylvania House Bill 705 sets MCLs for perfluorooctane and perflourooctanoic acid at 5 ppt. New York Senate Bills 2683 and 4381 also request the state Commission of Health to examine and set MCLs for 1,4-dioxane and chromium-6.

State MCLs call public attention to contaminants when they surpass the action level. However, deciding on MCLs at the state level can cause inconsistencies if states decide upon different levels for the same contaminant. This is confusing for consumers and state regulators looking to other states’ legislation when trying to set their own regulations.

Federal Updates

In the current legislative session, Congress has two bills on MCLs. House Resolution 147 encourages state and local governments to set reasonable standards for chromium-6 in drinking water. Senate Bill 519 gives EPA two years to publish an MCLG and a national drinking water regulation for 1,4-dioxane, perchlorate and perfluorinated compounds, perfluorooctanoic acid and perfluorooctane sulfonic acid. 

About the author

Kathleen Fultz is regulatory and government affairs coordinator for the Water Quality Assn. Fultz can be reached at [email protected] or 630.505.0160.