Last week, appearing before the Eastern Shore delegation, the then acting secretary of the Maryland Department of Environment (MDE), Ben Grumbles, clarified a controversy that has raged the past few years ever since Maryland established Total Maximum Daily Loads (TMDLs) to meet federal guidelines for the water quality of the Chesapeake Bay.
While acknowledging that the sediment trapped behind the Conowingo Dam in northeast Maryland and deposited in the Bay during heavy storms is a concern, Mr. Grumbles said it is not the only one.
And I would say not the most serious one facing the fragile state of the Bay’s health.
Mr. Grumbles simply said this: many different sources, point and non-point, inject nitrogen and phosphorous within Maryland and require close attention, unpolluted by the noise produced by some that Conowingo Dam is the main culprit behind the Bay’s poor water quality.
Since the Conowingo Dam sediment became a rallying call for claims it was the principal cause of Bay pollution, I always thought this opinion was flawed, if not rather simplistic. I wondered how other sources of damaging particles could be ignored, or at least considered secondary.
Mr. Grumbles, now confirmed as MDE secretary, provided a large dose of common sense.
A study called the Lower Susquehanna River Watershed Assessment (LSRWA) produced in November 2014 in large part by the U.S. Army Corps of Engineers, found that the sediment behind the dam is not causing most of the Bay’s pollution. It’s the nutrients attached to the sediment particles that pose the most severe challenge.
Science-based facts gathered independently speak loudly and convincingly.
While the Susquehanna Dam has reduced ability to trap sediment—and that is concerning—the bulk of sediment and nutrient pollution to the Chesapeake Bay from the Susquehanna River, even during hurricane conditions, emanates from several upstream sources, according to an official with the Corps of Engineers. These sources include agriculture, urban and suburban run-off, floodplains and erosion caused by uncontrolled stormwater runoff.
While the Conowingo Dam has become a touchstone for animated debate, all of us who love the Bay should take a deep breath and follow the science. The Bay’s health depends on rational research and rational actions.
That’s what Ben Grumbles said in so many words. My take: don’t be distracted by a controversy that detracts from a diagnosis that demands analysis of the nutrients and phosphorus entering our Bay from many sources.
A two-year study already undertaken by Horn Point Lab in Cambridge will build on the Corps of Engineers’ investigation of the impact of the Lower Susquehanna River Watershed. It is designed to help policymakers select best management options to reduce the onslaught of sediment and nutrients during heavy storms
.
According to Horn Point Lab, part of the University of Maryland Center for Environmental Science, “research will measure how much phosphorous and nitrogen is attached to sediment particles that go over the dams and determine the fate of these sediments and associated nutrients in the Chesapeake Bay.”
The results will be telling.
Jim Franke says
Egads! Use facts to make decisions?