By using the outflow from Howard County's Little Patuxent Water Reclamation Plant, the NSA leaves the ground water alone and reduces the amount of treated water the county sends to the Chesapeake Bay.

"The people who work here at NSA are the same people who live next door to you and me," Davis said. "We've got boats. We want the bay to be clean. We want our drinking water to be good. So we all look at it, both from an organizational perspective and a personal perspective, that we're part of the community, to make sure we do things that are right for the ecosystem."

Gerwin called it a "a big green project."

"Across the industry, the effluent out of wastewater plants is of such high quality nowadays that it's actually a marketable commodity," he said. "Not so much on the East Coast, where we have a lot of water. But out West, it's a big deal. And we're beginning to do that now.

"It's a resource that we used to dump into rivers and let it go. But it gets cleaner and cleaner and cleaner."

Ulman said the NSA is the first of several potential customers for county wastewater. He said the county also is in talks with Dreyer's Ice Cream, which operates a plant in Laurel.

"Data centers are big users," he said. "Places that have a lot of air conditioning needs. Dreyer's Ice Cream happens to have a freezer the size of a football field. You look around the port of Baltimore, cold storage facilities, power plants. … This is a really underutilized resource in the state."

Ulman is seeking the Democratic nomination for lieutenant governor in 2014. "Frankly, this is something that I'm really looking forward to driving statewide," he said.

NSA critics would prefer Howard County peddle its water elsewhere. The OffNow coalition, which includes Buttar's group, has developed model state legislation that would prohibit local governments from providing "material support" to the agency.

A state senator in Arizona has said she will introduce a bill there. Michael Maharrey, a spokesman for the Florida-based Tenth Amendment Center, said the coalition also has commitments from lawmakers in Utah, California and Washington state.

He says Maryland, where the NSA is based and Fort Meade is the state's largest workplace, "will probably be a tougher sell."

"But clearly our goal is to get this type of legislation introduced across the country," Maharrey said.

Davis has read about the coalition's efforts.

"You know, everybody's entitled to their opinion," he said. "But that's the political process."