Algae by the Bay; Nutrients From Sewage Plants, Farmland Blamed for Rise in Chesapeake Pollution

ANNAPOLIS -- Researchers say they have identified the villain in the decay of the Chesapeake Bay and not surprisingly, it is us.

Scientists wrapping up a six-year federal study say nutrients--mostly phosphorus from man's urban sewage treatment plants and nitrogen washing off his rural farming land--have overenriched the bay, spawning algae blooms.

When a similar problem existed in the Potomac River almost two decades ago, the solution--upgrading Washington-area treatment plants to remove phosphorus from the effluent-- was expensive: billion. It was undertaken anyway and today the algae problem is largely under control. The river in Washington is again widely used for recreation and fishing and many river problems have been reversed.

Now come algae blooms in the Chesapeake, though not yet as noxious as the Potomac's, and concurrent steep declines in rooted aquatic plants, oxygen levels in the water and populations of desirable fish and shellfish. There is, according to Eugene Cronin of the Chesapeake Research Consortium, "a general sense that the bay is growing murkier and dirtier."

In the sewage treatment vocabulary, nutrients are those chemicals that support the growth of algae and other undesirable forms of marine life. They are unaffected by the sewage treatment process because by law the principal function of those facilities is to remove disease-carrying bacteria. Nutrient removal, an expensive add-on, particularly for nitrogen, is one of the goals of advanced waste water treatment and is not common nor required by law.

The cost of cleaning the bay, a body of water hundreds of times larger and far more complicated than the Potomac, also will be immense. States bordering the Chesapeake are on the brink of a major cleanup investment that could, if Maryland gets its way, rival the cost of upgrading the Potomac.