There is a new acronym in the air, and I don't want to sound like a curmudgeon, but I don't think it's anywhere near the guaranteed panacea some folks seem to think it is. So far, it has been dangerously underanalyzed and shamelessly oversold. Other than that, it's a great idea.

I am referring to something called TMDLs, which stands for "total maximum daily loads." It is a concept and a requirement hidden deep in the details of the Clean Water Act, where it remained essentially undisturbed for more than a quarter century. Oh, there were experts on water law who knew it was there, but when you mentioned it as a potentially powerful tool, you mostly got snickers and mutterings of disbelief that anyone would ever take it seriously.

Well, it is being taken seriously, among others by environmental groups, who have brought dozens of lawsuits against states for not complying with it. Enough of these cases have now been won by the plaintiffs that the EPA and the states are working to settle as many of the remaining suits on as favorable terms as possible.

As a result, one can expect a TMDL allocation to be completed in the next 10 or so years for each pollutant exceeding the water quality requirements in each stretch of river of each state. This adds up to thousands nationwide, and hundreds in a number of states.

So what is a TMDL? It is essentially a plan which identifies all of the sources of the given pollutant and then allocates the necessary loading reductions to each source to bring that stretch of river into compliance with the requirements for that particular pollutant.

Does this sound familiar to those of you active in the cleanup of the Chesapeake? It should, because what we are doing with nitrogen and phosphorous in our tributary strategies is very similar to a TMDL. It is actually a total maximum annual (as opposed to daily) load, or TMAL. With nutrients, the annual approach makes more sense because of the way they act over time downstream. We have taken the loadings to the Bay, divided them among the tributaries and developed individual strategies to reach our 40 percent reduction goal. The difference is that our tributary strategies are cooperative voluntary efforts, while TMDLs are sometimes used to make enforceable reduction goals.

So when you start out, the TMDL looks a lot like what we've been doing. First calculate the loadings from all the permitted and other point sources. Then estimate the origins and loadings of nonpoint sources, and even look at the air as a source. But at this point things get more fuzzy, because there is no general authority to regulate nonpoint sources under the Clean Water Act. And no one has yet figured out how to use the Clean Air Act to regulate a facility emitting a pollutant which is causing water pollution, sometimes to a body of water lying at a considerable distance.

So the tendency is to return to the same old point sources and seek further reductions. The problem is that we know that in a lot of places these point sources simply can't reduce enough to offset the air and nonpoint sources. So what happens now?

This is the inherent flaw of the TMDL process, and the reason it was left in hibernation all these years. Those who have pushed TMDLs on states seem to think that this outcome will lead through some sort of back door to new Clean Water Act authorities to regulate nonpoint sources. I don't think so. A far more likely outcome is that after years of effort, the process will lead in a circle right back to the point sources and frustration.

This need not be the case. There are plenty of ways to deal with nonpoint sources short of federally enforceable requirements. The problem is that the "Clean Water Act culture" insists that every state decision be reviewable and reversible by EPA employees in order to pass some test of purity. This is nonsense; there are plenty of federal statutes that rely on states to use their own laws as authorities and provide broad federal oversight to monitor compliance without authority to intervene. The Coastal Zone Management Act is one very successful example. The work of the Bay Program provides another. There are a number of ways that states can deal with nonpoint source pollution short of permits and regulation of every instance. The Virginia "bad actor" laws for forestry and agriculture, and the Pennsylvania nutrient management law are good examples of such selective oversight.

If the TMDL process takes this more flexible approach to the nonpoint source issue, it can succeed, just as the tributary strategies continue to have support. And if the EPA can focus less on case-by-case compliance and more on solving some of its own internal problems, such as how to make the Clean Air Act permits responsive to remote water quality needs, then some real progress can be made.

But I fear that this is too much of a cultural change for the agency and its environmental prodders. It is too easy to insist that the answer is more command and control. It is too hard to really make the Clean Air and Clean Water Acts work together to achieve the best overall environmental results. And it is too messy to deal with nonpoint sources by letting the states find their ways.

Back in the early '70s, there was another part of the Clean Water Act which held a lot of promise; it was section 208, and it set out a comprehensive regional planning process to determine where to invest in wastewater treatment. But it wasn't figured out in advance how this planning process would withstand the tremendous pressures from public works departments and developers wanting to get hold of the federal funds. In the end it couldn't, and the funding commitments were unhitched from the plan requirements, making years of planning meaningless and unleashing the forces of sprawl with the full support of the EPA's billions in sewer subsidies.

The lesson is that it is worth the effort to figure out now just where the TMDL process is taking us. How will the EPA and the states deal with the nonpoint sources? Will case-by-case oversight be required? If not, what is acceptable instead? Can incentives be provided? Will the air permit issues be thought through? What if the air source is located in a different state? How can we find and sell the more workable solutions-nutrient management, forest buffers, bad actor laws?

If we do these things, a strong and broadly supported process can evolve that can get environmental results. If we do not, TMDLs could be another investment of years, with a payout only in frustration and recrimination, and no improvement to our streams and rivers. Let's think it through and do it the right way.