If only. In the ensuing debate - sure to continue through a public comment period through Oct. 20 - some cannot even agree on what the rule says, let alone whether it's good.
It would restore historic protections to feeder creeks, wetlands, and even some intermittent streams, according to the EPA. For instance, federal permits would be required for dredging, filling, or discharging into them.
Builders warn of higher costs and limits on development. Farmers worry they will be restricted in how they use their land, though the EPA insists that agricultural exemptions will protect farmers.
Nancy Stoner, the EPA's acting assistant administrator for water, was in the Philadelphia region recently stumping for the rule, calling it a tweak, "not a sea change."
Basically, she said, "you have to protect headwaters to protect downstream waters."
Science is clear on that necessity, said Bernard Sweeney, director of the Avondale-based Stroud Water Research Center, which has studied the workings of freshwater streams for four decades.
"It starts from the groundwater outflow that forms wetlands, which coalesce to form smaller streams . . . then the river," he said. "It's all one physical, chemical, and biological continuum."
Sweeney likened river systems to the human circulatory system. Focusing only on larger waterways "is almost like saying the only important blood vessels . . . are the arteries, not the capillaries." But in the latter is "where the important work is going on."
More than 85 percent of the nation's stream miles "you can jump across," he said. One in three Americans, the EPA says, depends on them at least in part for drinking water.
Those waterways also "produce the fish that we eat, the water to grow food, energy generation, manufacturing," Stoner said. "You really can't have a strong economy unless you have well-protected water resources."
But if science is clear, regulatory authority isn't.
The rule's critics say it takes the concept of the Clean Water Act too far. They contend that only navigable waters should be covered, not every seepage.
Congressional Republicans have launched efforts to prevent the EPA and the corps from finalizing or implementing the rule. The two agencies "want to have jurisdiction over all land, wet or dry, and this is a way for them to get it," said Rep. Bill Shuster (R., Pa.) in a state Farm Bureau video highlighting the rule's shortcomings. "For anyone to make the argument that this is just tweaking the rule . . . is wrong."
The fields on Mark Scheetz's 22-acre family farm in West Rockhill Township, Bucks County, have ditches, which prevent soil erosion during heavy rains. Ninety percent of the time, they're dry. But what if the EPA came in and said he couldn't farm within 150 feet? He'd still have to maintain land he couldn't use and pay taxes on it.
"The real concern here is that farmers won't find out which wet spot, which pond, which gully, which ditch is considered to be a water of the U.S. until the EPA or an environmental group brings a legal action against the farmer," said John Bell, government affairs counsel for the Pennsylvania Farm Bureau. "Farmers deserve a lot more clarity than that."
When Wesley Horner, senior adviser for water resources at the Brandywine Conservancy, thinks about the Brandywine - "a watershed under stress" - he sees the rule as a way both to improve water quality and to accommodate more development in appropriate places.
The smaller streams "are doing yeoman's work for us," he said. "We really have to try to keep them as intact as possible."
Environmental groups are dispatching their volunteers and summer interns to drum up support. Environment New Jersey alone is sending out 50 a day to knock on doors, aiming to generate 15,000 comments by the end of this month, "and we're already halfway," said its director, Doug O'Malley.
"We shouldn't be protecting waterways based solely on whether you can put a boat on it," he said.
Adam Garber, field director for Environment Pennsylvania, said that lack of clarity had meant "more pollution" because the EPA simply backed off some waterways. That has left nearly 60 percent of Pennsylvania waters in bureaucratic limbo, said Brooks Mountcastle, eastern Pennsylvania director for Clean Water Action, a national advocacy group.
Other supporters include hunters and anglers - and at least one major industry.
At a recent EPA event by the Brandywine Creek in Downingtown, one of those who spoke on the bill's behalf was Bill Covaleski, president of nearby Victory Brewing Co.
"Cleaner, better water," he said, "is great for a brewery."