U.S. Sen. Ben Cardin of Maryland has a vision for restoring the Chesapeake Bay.

His vision is simple and elegant. In it, scientists calculate the maximum amount of nutrient and sediment pollution that the Bay and its tributaries can sustain and still meet water quality standards. Based on the best available science, the EPA allocates pollution loads by state, each according to its contribution. State policy makers create the necessary policies to ensure the allocations are achieved. Citizens reap the benefits of clean water.

Cardin isn't the first person who has had this vision for improving water quality in the Bay. But, as we surely know, it has gone nowhere. The result has been dead zones, fish kills, algal blooms, consumption advisories and beach closures that threaten our health and hurt local economies.

Vision is an essential quality, but it doesn't get the job done by itself.

The difference between Cardin and others who have shared his vision is that he is a U.S. senator. He has therefore introduced his vision as a bill-Chesapeake Clean Water and Ecosystem Restoration Act-to amend the section of the federal Clean Water Act that applies to the Chesapeake and the rivers that feed it. If his bill passes Congress and is signed into law by President Barack Obama, the six watershed states and the District of Columbia will have to submit plans to the EPA detailing how they will achieve their share of the pollution reductions that scientists say are needed.

If the states don't put the policies in place and achieve measurable, incremental pollution reductions within specified time frames, they will face consequences, including the loss of hundreds of millions of dollars in federal funds authorized by the Clean Water Act.

It is amazing to me how long the United States has been waiting for someone like Cardin to step forward to improve the Clean Water Act. Thirty seven years ago, Congress overwhelmingly overrode President Richard Nixon's veto to create the Clean Water Act as we know it. Its single greatest omission was its failure to require the states to adequately address nonpoint pollution-a flaw that looms much larger as we come to understand just how damaging nonpoint sources of pollution can be. Congress overrode President Reagan's veto in 1987 to improve the Act, but not nearly enough. Nothing substantial has happened since then.

Finally, getting nonpoint pollution under control, as Cardin's bill would do, would be the dawn of a new day for the Chesapeake Bay. And although his bill would only apply to the Bay watershed, it provides a model for how to dramatically improve the Clean Water Act nationally.

As Cardin introduced his bill on Oct. 19, Sen. Barbara Mikulski of Maryland and Sens. Tom Carper and Ted Kaufman of Delaware stepped up to join him. On the House side, Maryland Congressman Elijah Cummings and 10 others introduced a nearly identical bill on the same day.

Quietly encouraging House members is Minnesota Congressman Jim Oberstar, who was deeply involved in the Clean Water Act efforts in the 1970s and 1980s. Oberstar chairs the committee that will consider Cummings' bill.

Not everyone wants to see Cardin's bill pass, of course. Some still believe that existing policies and programs will get the job done, but the history is sobering. There is no reason to believe that the Bay cleanup will happen without this legislation.

In the new day for the Bay, I might have to make some changes to help get nonpoint runoff under control. You might, too. Certainly, the people creating far more than their share will have to make changes. But for them, there is a lot of money in the bill to help, complementing the hundreds of millions in federal funds already available. From a societal point of view, the real cost of not getting the problem fixed is enormous.

Eleanor Roosevelt is said to have written that the future belongs to those who believe in the beauty of their dreams. Cardin, Cummings and the other members of Congress standing with them deserve our admiration for not just dreaming, but for acting decisively to save the Bay for our children and grandchildren.