The environmental challenge that weighs heaviest on the minds of the American public, polls show, also happens to be one over which every branch of government is arguably the most deeply divided: How to protect clean water.

On one side of the ideological gap are environmental and conservation groups that want U.S. EPA to take the lead by implementing strong, sweeping regulation. On the other side are the agriculture, homebuilding and mining industries that want EPA’s power curtailed so that states can regulate most waters as they see fit.

The two sides share no common ground on the key issue: where federal jurisdiction over water starts and stops.

But common ground is exactly what Sen. Ben Cardin (D-Md.) hopes to find.

Cardin, chairman of the Senate Environment and Public Works Committee’s subpanel on water and wildlife, could be called the Senate’s “King of Water.” He is the committee’s point man on water issues, shepherding bills through the deeply partisan committee aimed at tackling storm water runoff, supporting the Obama administration’s controversial Chesapeake Bay cleanup program and restoring the nation’s other great water bodies.

His greatest test could be in striking a bipartisan compromise on legislation that would end the dispute over which waters, streams and wetlands deserve federal protection. Asked recently if there was a possibility that the two sides could come together on a bill that has so far eluded Congress, Cardin spoke of the difficult political climate but did not rule out the possibility.

“There could be,” the 67-year-old lawmaker said. “That’s an area where it really does require us to get together. It’s going to be difficult. We’re not going to give up on trying.”

Difficult, indeed, considering how many recent, previous efforts have failed. Ever since the Supreme Court split over the question of Clean Water Act jurisdiction in 2006, the last time it ruled on the matter, the high court has declined eight requests to take up the issue again. EPA has likewise neglected to write new, clarifying regulation. Although EPA signaled that efforts would begin soon, many observers remain skeptical given the political risks that writing major new regulation could carry as the 2012 election draws closer.

In Congress, the urge to bridge the gap on water policy distinguishes Cardin from colleagues on both sides of the aisle. Most have either stubbornly and repeatedly floated highly partisan measures to either reword the Clean Water Act to their side’s liking or otherwise disarm EPA by stripping funding or regulatory authority (Greenwire, June 22).

This year in particular, a pattern has begun to emerge: EPA takes action under the Clean Water Act, usually as the result of a court order or a lawsuit filed by environmental or conservation groups. Opponents in Congress respond by filing legislation that either seeks to strip EPA of the necessary funding or authority.

Most experts now agree that only legislative action from Congress will end the impasse.

Ben Grumbles, EPA water chief during the George W. Bush administration, predicted that recent EPA efforts to simply reinterpret the Clean Water Act in place of engaging in the deliberative and admittedly difficult process of regulation writing would only fall short.

“We need a more durable, bipartisan legislative solution that keeps America on track toward gaining wetlands and improving watershed health,” Grumbles said.

Rather than work to draw up legislation that could address the jurisdictional questions raised but hardly solved in the two most recent Supreme Court decisions — Solid Waste Agency of Northern Cook County v. United States Army Corps of Engineers in 2001 and Rapanos v. United States in 2006 — Congress seems content to engage in trench warfare.

“Our preference would be to try to work with members of Congress to try to look for solutions to remedy those Supreme Court decisions,” said Scott Sutherland, director of the governmental affairs office for the conservation group Ducks Unlimited, which supports strengthening water and wetlands regulation. “There doesn’t seem to be a lot of interest in doing that right now.”

Weighing environmental and economic concerns

That is contrary to what Americans want, according to a March 28 Gallup poll that found Americans worry most about threats to clean water among nine major environmental issues. Clean water concerns outranked those of air pollution, species extinction and global warming, the poll found.

But Americans also want the economy turned around, and a slate of major industries — agriculture, homebuilding and mining — have convinced their powerful allies in Congress that tightened regulations will have direct impacts on their ability to hire workers and do business.

“What we are experiencing at least in the Appalachian region is an overreach by EPA,” said Rep. Nick Rahall, the top Democrat on the House Transportation and Infrastructure Committee from West Virginia, where federal regulators have come down hard on mountaintop mining operations.

Cardin, who has spent 45 years as a legislator, first in the Maryland General Assembly where he rose to speaker of the House, then in the U.S. House and for the past four-and-a-half years in the Senate, has shown a penchant for compromise — so much so that he has been attacked for it from the left. Last year, when Cardin partnered with conservative EPW Committee ranking member James Inhofe (R-Okla.) on an amendment to Cardin’s Chesapeake Bay legislation, some liberal environmentalists fumed that the bill had lost its teeth.

“He stepped over to the wrong side of the line,” wrote Rena Steinzor, law professor at the University of Maryland and president of the Center for Progressive Reform (E&ENews PM, July 6, 2010).

But EPA officials defended the bill, which never received a floor vote, as a step in the right direction, even in its weakened form (Greenwire, Aug. 25, 2010).

Environmental groups see Cardin as a chief ally in the fight over clean water. “There is no greater champion of Americans’ right to clean water than Senator Cardin,” said Josh Saks, senior legislative representative for water resources campaigns with the National Wildlife Federation. “He is the lead voice for clean water and the restoration of America’s great waters in Congress and if he continues, he’ll go down as one of our best champions of safe drinking water and clean clear rivers and streams.”

Cardin, who has already reached out to Inhofe to resume talks on a resurrected Chesapeake Bay bill, has said negotiations could always turn to a bill that might clarify federal powers under the Clean Water Act. That would put Cardin’s legislative skills to a tough test.

Recent failed bills to strengthen and clarify the Clean Water Act, which explicitly protects all “navigable” waters, have tried to strike that adjective. The word derives from the commerce clause of the U.S. Constitution and is seen by some as a strict limit on which waters fall under federal, versus state, protection. Inhofe recently said any effort to delete the word would be a nonstarter.

“So long as the effort is to take the word ‘navigable’ out, I don’t know what you can do to reach common ground,” Inhofe said.

But would compromise be possible if the word stayed put?

“Sure,” Inhofe said. “Because that’s the main issue.”