Complications foil bay cleanup Runoff: Even with farmers ,, using less fertilizer, other pollutants and a natural phenomenon have negated improvements.

On The Bay

May 08, 1998|By Tom Horton | Tom Horton,SUN STAFF

A DECADE ago, the Chesapeake Bay restoration effort was gearing up for a formidable task -- reducing polluted runoff from fertilizer and manure by 40 percent on tens of millions of farmland acres draining to the bay.

The goal was to do it by 2000, and possibly no one familiar with the scope of the problem thought it would all be done by then.

But hopes were higher in a few "targeted watersheds," small subsets of the vast, 64,000-square-mile Chesapeake watershed. There, intensive planning, monitoring and restoration would showcase what could be done ideally.

One of those singled out for attention was a little stream called German Branch, which collects water from 20 square miles on its 10-mile meander through Queen Anne's County toward the Choptank River.

More than two-thirds of its watershed was used in agriculture, and a 1985 water-quality survey there had documented excessive levels of the "nutrients" nitrogen and phosphorus. Scientists figure these pollutants must be reduced 40 percent to have any chance of restoring healthy oxygen levels and vast sea grass habitats throughout the bay.

Starting in 1989, countless hours and perhaps a million dollars have been spent on German Branch. State, local and federal agricultural and environmental agencies, and scientists from the Smithsonian Institution, have collaborated to reduce nutrients running into the watershed.

Equally critical, farmers throughout the stream valley have, by all accounts, been cooperative.

They have voluntarily, at some expense to themselves, adopted "best management plans" to conserve soil, reduce fertilizer use and otherwise improve water quality on almost 100 percent of German Branch's cropland.

Even with all this, no one expected miracles. But everyone expected something.

What they got is best expressed by the most recent report from the Maryland Department of Natural Resources on the targeted watershed effort in German Branch:

"It is difficult to identify any positive water quality results obtained from BMP [best management practices] implementation in the watershed.

"The project has shown that what have been assumed to be adequate and accurate [management plans] are not living up to their estimations and expectations."

That report covers 1990 through 1995, but there is no reason to think much has changed in the past few years, according to John L. McCoy, one of the project leaders at DNR.

Nitrogen since 1990 has risen in the water of German Branch. This alone is not so troubling, researchers say.

That is because nitrogen gets into streams primarily through ground water, which seeps through the soil so slowly that fertilizer put on a field in, say, 1988, may just be emerging into German Branch.

This lag time, not well understood when the study began in 1990, at least partly explains the lack of improvement.

More perplexing are estimates that as much nitrogen -- and more phosphorus -- are being applied to land in the German Branch as when the project to reduce them began.

This means that even if all agriculture on German Branch ceased today, excessive nitrogen would be seeping out until 2008 or later.

As for phosphorus, it sticks to soil and doesn't travel through ground water. But the continuing upward trend raises concern that the soil in German Branch can't hold it all, meaning it could enter the stream in higher levels in coming years.

The German Branch results are sobering, even depressing. But the report overall doesn't seem as much an indictment as an insight into the unexpected complexity of managing pollution from the land.

For example, driving through the bucolic German Branch watershed, one might think it a timeless, rural scene. But the changes since the study began have been huge, and largely impossible to predict: Shifts in federal subsidies and world grain prices dramatically shifted crops from corn to wheat, and increased the number of crops grown. All this offset farmers' hard-won reductions in nitrogen in other areas.

Poultry expanded and dairy farming dwindled. Dairy recycles and contains nutrients in manure more efficiently than poultry operation.

An ornamental plant nursery expanded dramatically, releasing far more phosphorus than traditional agriculture. (Grain farmers in German Branch have made significant reductions in their use of phosphorus.)

Such nurseries fall between the cracks, "not agriculture, not industry," said Queen Anne's farm extension agent Paul Gunther. Attempts to work with the nursery, which has changed managers four times, have been frustrating.

Much more sewage sludge was spread on German Branch farms in recent years. Soil scientists say that sludge, though higher in phosphorus than chicken manure, tightly binds the chemical. But Gunther and others suspect it has contributed to harmful runoff.

Another factor is that best management practices range from genuinely effective pollution controls to what a farmer is willing or able to do. Researchers had no way to check the quality of what farmers did.

I wondered how German Branch would be treated by the state-of-the-art computer model that simulates the effects of cleanup strategies for the whole bay watershed.

Given all the paper progress made there, "Undoubtedly the model would have given them credit for cleanup," said Lewis Linker of the Chesapeake Bay Program in Annapolis.

It would have done it instantly too, because the model doesn't incorporate the lag times for nitrogen in ground water.

Linker said that across the whole bay watershed, the model averages agriculture impacts pretty well.

But results from other targeted watersheds in Maryland and Virginia indicate German Branch is more typical than not.

The stricter nutrient law just enacted in Maryland to prevent Pfiesteria will help places like German Branch clean up.

But deadlines for action stretch to 2005. And the law does not apply to Virginia or Pennsylvania's huge parts of the watershed.

Pub Date: 5/08/98

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