The head of the Indiana Department of Environmental Management will step down and take a leadership position in the U.S. Environmental Protection Agency’s water division.

Bruno Pigott, who was appointed IDEM commissioner by Gov. Eric Holcomb in 2017, will step down Dec. 3 and become the deputy assistant administrator in the EPA’s Office of Water.

“I’m grateful that I was able to serve under a governor who has a strong commitment to protect human health and the environment,” Pigott said in a statement. “I was honored to work alongside my IDEM colleagues who have dedicated their livelihoods to protect our environment and because of them and the support of Gov. Holcomb, IDEM was able to make significant improvements.”

Pigott joined IDEM’s Office of Water Quality in 2000 and became the division’s assistant commissioner in 2005. He served in the role until 2015, when he became IDEM’s chief of staff.

“Bruno Pigott’s lifelong passion is to make Indiana and our country a better place to live,” said Holcomb. “For more than 20 years, there’s been no one more dedicated to balancing environment and business than Commissioner Pigott. With his guidance, the agency has streamlined processes, eliminated backlogs and cleaned up contaminated properties.”

Pigott will join the EPA’s Office of Water at a critical juncture that could help improve and maintain the health of Indiana’s waterways.

The Biden administration is currently working on crafting a rule that will provide a new definition of which waterways fall under the protection of the Clean Water Act.

The Clean Water Act regulates the discharge of pollutants into what the law specifies as “waters of the United States.”

The ambiguity of that phrase has fueled a decades-long battle over which waterways constitute “waters of the United States” that are protected by federal law.

Between 1986 and 2015, seven broad categories of waterways were recognized as “waters of the United States.” Several court cases refined the definition.

The Obama administration wrote a new definition that included more waterways, including isolated wetlands and temporary streams, known as ephemeral streams. Indiana and other states sued to stop the rule from being implemented.

The Trump administration wrote its own rule, the Navigable Waters Protection Rule, that limited the WOTUS definition to four strict categories. The rule was struck down by a federal judge in August, and the federal WOTUS definition returned to the 1986 version.

The Biden administration said it will draft a new version that takes into account the opinions of states, tribes, local governments, scientists and non-governmental organizations.

Pigott could play a prominent role in the drafting of the new WOTUS definition, which, in turn, could have important repercussions on Indiana’s waterways and decisions faced by next IDEM commissioner.

The governor’s office said it would name a new commissioner at a later date.