In the wake of the drinking water crises in Flint, Michigan and elsewhere, the U.S. Environmental Protection Agency (EPA) proposed a rule on Oct. 10, 2019, that would impose new lead requirements on drinking water systems. If finalized, the new rule would mark the first change to the lead and copper rule (LCR) since 1991.

Drinking water systems throughout the country still rely on lead service lines to connect treatment plants to consumers. Water treatment chemicals can cause lead to leach from service lines. In 1991, the EPA adopted a rule under the Safe Drinking Water Act (SDWA), requiring drinking water systems to implement corrosion control measures when the lead level is above the “action level” of 15 parts per billion (ppb). Tap water samples must be collected, and if more than 10 percent of tap water samples exceed the lead action level of 15 ppb, then water systems are required to take actions. This method allows some percentage of the customer taps to exceed the action level, without the water system having to act.

The proposed rule retains the 15-ppb action level, but requires a more comprehensive response. For example, water systems must replace the portion of the lead service line they own whenever a customer replaces her portion of the line. The proposed rule also introduces a trigger level of 10 ppb that requires more proactive planning in communities with lead service lines. In addition, the proposed rule will require development of lead service line inventory and more robust sampling and risk communication.

Curiously, however, the proposal would decrease the annual percentage of lead service lines a water system must replace when its tap water exceeds the 15-ppb action level: the existing rule requires utilities to replace seven percent of their lead service lines annually, while the proposed rule would reduce that percentage to three.

While the EPA argues that the new requirements, along with the 10-ppb trigger, will reduce the levels of lead in drinking water, critics charge that the changes do not go far enough, and that reducing the annual replacement rate is wrong.

The public will have 60 days from the date of the proposed rule’s publication in the Federal Register to submit comments (in Docket No. EPA-HQ-OW-2017-0300).