Potomac's limits ignored

On The Bay

Restoration: Despite decades of cleanup efforts, prospects for returning the river, and by extension the Chesapeake, to 1950s quality levels aren't good.


WHILE researching the Internet for the latest on "nutrients," like nitrogen and phosphorus, that are the principal pollutants of the Potomac River, I accidentally pulled up a piece on "nutrition" -- obesity and dieting among Americans.

It made me recall the time I did a huge computer search on marine mammals, only to net everything I never wanted to know about the Miami Dolphins football team.

But with my nutrient-nutrition glitch, something clicked.

People in this country are worldbeaters, it turns out, in gaining weight and in losing it. We are both obese and dieters at unprecedented levels.

It seems a simple equation -- calories in must equal calories spent to maintain a given weight. But awash with every delicacy and hyper-bountiful with food, why talk limits? How boring.

There's more money in publishing enough diet books to fill Harvard's libraries. Who can resist picking up the supermarket tabloid featuring the "Dolly Parton all-you-can-eat fried chicken diet"?

This brings me to nutrients in the Potomac, the "nation's river," and the Chesapeake Bay's second largest tributary. Its problems are the bay's problems.

My research was for a talk on the prospects of restoring the river, and by implication the bay, to levels of water quality and aquatic habitat not enjoyed since the 1950s.

Looking back over a couple of decades of serious restoration work, I concluded the prospects aren't bright.

I don't mean to discount the substantial money, science, blood, sweat and tears that have gone into the cleanup effort from government, private citizens and environmental groups.

Without that, the Potomac and Chesapeake would be cesspools today. The last decade has seen its share of victories, from the comeback of eagles and rockfish, to the return of good bass fishing within the District of Columbia.

But I'm not talking winning battles here. I'm talking about how the war's going to end.

The literal bottom line in the broad, lower Potomac where it merges with the bay is not much improved since systematic environmental monitoring began in 1985.

Then and now, a huge volume of deeper waters every summer loses its oxygen for weeks and months -- the result of too many nutrients -- and grows too much algae, which decomposes and sucks up vital oxygen in the process.

Then and now, thousands of acres of once lush underwater habitat in the form of submerged vegetation is mostly gone. Too many nutrients grow too much algae, shading light needed by the grasses.

The upper tidal Potomac, from Quantico to the District, has by contrast made a dramatic comeback, the result of sharp reductions in phosphorus coming from the sewage treatment plants that dominate water quality in the tidal Potomac.

At the cost of a billion dollars or more the sewage plants have removed more than 97 percent of the phosphorus from their discharge.

So even as more millions of metro D.C. residents have swelled absolute flows of sewage discharges to the Potomac, pollution has gone down.

It almost seems like having your cake and eating it too.

Almost. Population continues to swell. The region is losing trees to development at the rate of 60 acres a day, depriving the river of a buffer from polluted storm water runoff and airborne nutrients.

Sewage treatment plants are virtually at the limit of technology in removing phosphorus, which has edged upward slightly in the past few years.

This is mostly from runoff as a result of large rainstorms during the 1990s. But a more permanent upturn is forecast in the next decade purely from more people and more sewage flow.

The lower river's condition might get better in the next decade. While phosphorus causes the problems in the fresh water upstream, nitrogen is the culprit in the lower, saltier waters.

The river's sewage plants are doing a good deal to reduce nitrogen, just as they did phosphorus earlier.

But then what? More people, more sewage, limits of technology, more loss of natural pollution controls like trees.

So are we saving the river, saving the bay? In the short term, perhaps yes. But we are not even discussing the root issues, like population growth, that threaten to reverse all that technology has done.

It is not so unlike the binger-dieter who is losing weight -- this month -- but does not want to talk about a more moderate style of consumption.

Sewage is one example of how we are "saving" our environment.

Another is making cleaner cars, which reduces nutrients going into the air (a major source of bay pollution) -- until the ever-increasing miles we drive each year turn the pollution curve back upward.

With cars, the real issues -- how many miles, how many more roads, alternatives to cars from bikes to subways to building walkable communities -- get short shrift.

How much is enough? Can there ever be enough? Whether we're striving for healthy bodies or healthy rivers, talking nutrition or nutrients, these are the real questions.

They have no simple or easy answers. But the future of our environment demands we at least recognize they are the right questions.

Pub Date: 4/23/99

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