Protecting Our Drinking Water Keeps Him Up at Night

DC was under a drought watch for almost a year before conditions improved earlier this summer. That might not have made a huge impression on most residents, but for Michael Nardolilli it was a big deal. He’s executive director of the Interstate Commission on the Potomac River Basin, created by Congress in 1940 to help manage and protect the river—and, therefore, the city’s water supply. If drought conditions had persisted to the point where there wasn’t enough water for drinking, showers, fire suppression, or sustaining the river’s aquatic life, it would have been his responsibility to deal with it. The Garbage song “Only Happy When It Rains” should be his personal anthem, he likes to joke.

In the worst-case scenario, Nardolilli would be the one to make the decision to tap our emergency water reserves, asking the US Army Corps of Engineers, which manages the Washington Aqueduct, to release the water. Millions of gallons would be let loose from Jennings Randolph Lake, about 170 miles from the city. Then we would wait: Water from this reservoir takes nine days to travel down the Potomac before residents can use it.

Thankfully, that’s a call Nardolilli has never had to make. But it’s one of many operational decisions that he and the ICPRB have to plan for. Arlington, Falls Church, and DC are the most vulnerable jurisdictions in the country because they have only one source of water. That means if the Potomac were to become fouled by accidental or intentional contamination, the river as a means of water conveyance could be shot. Droughts are especially complicated; if Nardolilli decided to release the backup supply and the weather changed to rain, the effort could be for nothing. “These are the issues that keep me up at night,” he says.

Nardolilli, who grew up in Jersey City, spent 20 years as a corporate lawyer in DC. He decided to change direction after one of his kids asked what he did for a living and he realized his job was mostly about money. Thinking about the pro bono work he’d done related to ecological conservation sparked an epiphany: “I could flip this and make environmental work primary for the second half of my life,” he recalls. That led to almost three decades in leadership jobs at places like the Northern Virginia Conservation Trust, the C&O Canal Trust, the Montgomery Parks Foundation, and the Northern Virginia Regional Park Authority. Since 2019, Nardolilli has overseen the Rockville-based ICPRB.

Moving forward, his job will only get harder as climate change makes conditions more variable and less predictable. Low-flow toilets and showerheads are helping, Nardolilli notes, and the Army Corps of Engineers is studying options for greater local water resiliency, such as acquiring a quarry for additional water storage. But a major drought that threatens our supply is due at some point. “I’m an optimistic guy,” he says, “but I’m concerned.”

This article appears in the August 2025 issue of Washingtonian.

Sue Eisenfeld