In the press and in legislative chambers across the watershed, the same question echoes: Can we reach the ambitious goals of restoring water quality in the Chesapeake and its tidal rivers by 2010?

Computer simulations tell us that over the last 20 years we have pared the nitrogen pollution load by an estimated 71 million pounds. We need more than 90 million pounds more.

A few will argue that we can still make that goal, while most partners agree that the deadline is now beyond reach. How can it be in 2007 that we are so far from our pollution reduction targets? Like so much that is associated with the Chesapeake Bay Program, the answer lies at the confluence of science and political initiative.

The original 1983 Chesapeake Bay Agreement brought the principal players together for the first time. They pledged to restore the Chesapeake, but it was a general promise and had little operational impact.

The right political moment for the Chesapeake Bay came in 1987. The restoration effort had garnered a mention in President Reagan’s State of the Union Address in 1984, and at the urging of regional leaders, Speaker of the House Tip O’Neill took a well-publicized tour of the Bay and came back pledging action.

A hard-fought, multiyear battle over the reauthorization of the Clean Water Act was under way. The Chesapeake Bay restoration effort became a separate section of the legislation. The bill passed with overwhelming majorities, overriding President Reagan’s veto. In February 1987, 20 years ago this month, it became Public Law 100-4.

That federal action would not have been enough, however. The real impetus was the 1987 Chesapeake Bay Agreement, signed in December. Virginia Gov. Gerald Baliles, who was chair of the Chesapeake Executive Council, recognized the need to turn the promise of the 1983 agreement into a real program with specific goals. The 1987 Bay agreement famously called for reducing the main pollutants that foul the Bay by 40 percent and to do so by 2000.

This was an audacious move. Scientists had only recently identified nutrients as the main culprits in the Bay’s decline. To call for a specific reduction target, based on an incomplete but growing body of scientific knowledge, was unprecedented. To link it to a specific deadline was revolutionary. But Governor Baliles knew that the only way to get the restoration effort in high gear was to set a goal and a deadline.

The ink was barely dry on the 1987 agreement when managers and policy makers started trying to figure out what that 40 percent goal meant. They eliminated from consideration the un-quantified pollution coming from Delaware, New York and West Virginia, reasoning that these states weren’t formal partners. Although we all know that “what goes up must come down,” back then scientists couldn’t quantify the significant portion of the Bay’s pollution load was coming from air pollution, and consequently didn’t include that load either.

Using 1985 as their baseline, they totaled up 185 million pounds of “controllable” nitrogen pollution from in-state point and non-point pollution sources. Simple multiplication yields a 40 percent goal: 74 million pounds.

Over the next 13 years, the Bay Program partners worked away at this goal. As we neared 2000, computer simulations suggested that we were nearing this target. Yet the Chesapeake Bay’s health was only marginally better.

During the 1990s, Bay scientists came to better understand that the amount of nitrogen flowing into the Bay annually was much greater than the “controllable” load calculated in 1987.

The contribution from headwater states was important. Even more important, air pollution turned out to be huge, about 30 percent of the entire nitrogen load. Clearly, a new accounting was needed.

The Chesapeake 2000 agreement was a worthy political successor to the 1987 document. It has revolutionized how large-scale ecosystem restoration is understood and managed. Importantly, the 2000 agreement approached pollution reduction targets from the perspective of the Bay’s living resources. By 2003, the scientific community had reached consensus on the new goal: The Bay’s creatures could only thrive when the nitrogen pollution load is 175 million pounds annually or less. “Controllable” or not, the cap has to be 175.

Instead of the “controllable” 40 percent goal of 74 million pounds, we now realize that to get down to the 175-million-pound nitrogen cap, the total estimated reduction needs to be almost 163 million pounds, more than twice the original estimate.

The partners continue to make gradual progress, even in the face of rapid population growth and the even more rapid loss of resource lands, especially forests.

Computer simulations of the pollution reduction actions taken by all the partners, including those in the headwater states, totaled more than 71 million pounds of nitrogen by the end of 2005. Based on recent rates, the partnership probably met the old “40 percent goal” of 74 million pounds of nitrogen reductions during 2006 (the data won’t be collected and analyzed until later this year).

But in reality, we are a long way from a restored Bay because that target was too low. We have about 92 million pounds to go.

What will it take to reach these much more ambitious targets?

On the farm, we will need to achieve a true nutrient balance. This means accelerating on-the-ground implementation of comprehensive nutrient management plans. Particular attention needs to be paid to the hotspots in the Conestoga watershed in Pennsylvania and the Delmarva Peninsula.

We need regional planning with real muscle that adopts the medical profession’s motto: Primum Non Nocere, “Above all, do no harm.” That means offsetting any additional loads caused by the watershed’s rapidly increasing population. Environmental site design and low impact development techniques must become part of every city and town’s building ordinances. In concert with these efforts, we need a major emphasis on forest conservation and riparian forest plantings.

We have a good plan in place to control pollution coming from wastewater treatment plants. We need to stick with that plan and press for its quick implementation, along with the strict enforcement of new pollution limits.

Federal air pollution control efforts and the host of additional actions being proposed and instituted by our states will help to slash air pollution. Again, rapid implementation and rigorous enforcement will be essential.

In addition, we need to do a better job of controlling ammonia emissions from agricultural lands.

When the political leaders of the Chesapeake Bay set that heady goal for themselves in 2000, they didn’t know that the undertaking would be so massive. But the scientific community has provided the ever-changing set of Bay elected officials with sobering numbers for five years.

In bursts of energy, our partners have been responding to that challenge, but the data tell us that we aren’t on track to meet the 2010 goals. A radical acceleration in our rate of progress is needed.

Government actions rarely happen without a political consensus. Citizens have to decide that a restored Chesapeake is worth changing our habits, ranging from housing to transportation to energy and water consumption.

So are we going to meet the 2010 deadlines? The real answer lies in ourselves as much as it does in our leaders. Both need to make some profound changes, and time is not on our side.