Search for Conowingo Dam solutions continues

Managing Editor

CHESTERTOWN, Md. (Nov. 4, 2014) — Two alternatives to restoring the health of the Chesapeake Bay — one often mentioned but not acted on and another much more obscure option — were the topics of a forum last week hosted by the Maryland Public Policy Institute.
The often-mentioned option, dredging behind the Conowingo Dam, was the focus of a recently-released report from the institute by economist James Simpson.
Simpson said focusing on the nutrient-laden sediment behind the dam is a less costly and more efficient way to improve the Bay’s water quality. 
“Dredging the dam to reduce that sediment would be costly, but it would go much further toward addressing Bay pollution than any of policy actions currently being implemented in Maryland and expected in other states,” Simpson wrote in the report.
Maryland’s cost estimate to meet targets for nutrient and sediment reductions by 2025 is $14.4 billion but that only addresses a small part of the nutrients entering the Bay, he said.
Citing Chesapeake Bay Program and U.S. Geological Survey data, Simpson told the crowd at Washington College that the annual nitrogen load in Maryland is less than a third of the nitrogen coming from the Susquehanna River.
Across the Bay watershed, Simpson estimated states will spend $39.3 billion to achieve reductions of 34,000 tons of nitrogen, 2,000 tons of phosphorus and 667,000 tons of sediment.
But, he added, that would all be wasted if another storm event to the magnitude of Tropical Storm Lee passes through the region.
In September 2011, Lee dumped 15 inches of rain over five days forcing 42,000 tons of nitrogen, 10,600 tons of phosphorus and 19 million tons of sediment through the Conowingo Dam and into the Bay.
“So we’re going to spend $40 billion for nothing,” Simpson said. “For nothing.”
From the audience, Isabel Junkin, Chester riverkeeper argued that much of the money in Maryland is spent on restoration efforts in the rivers and creeks that feed into the Bay and wouldn’t be wasted because the sediment plume caused by such a storm wouldn’t enter those tributaries.
Simpson estimates the cost of dredging the 174 million tons of sediment in the dam’s reservoir to be $4.2 billion, not including disposal, extrapolating from the cost of the two million tons that is removed annually.
“Even at twice the cost, dredging the Conowingo would be a bargain in nutrient and sediment removal, given the $14.4 billion the state intends to spend to remove only 3.4 percent of the Bay’s nitrogen,” Simpson said.
Not so fast, said George Frigon, an Easton, Md.-based water treatment expert who joined the panel in place of Robert Summers, Maryland Department of Environment secretary who was scheduled to appear at the forum but cancelled the day before the event.
Frigon said the amount of sediment behind the dam is enough to cover 10,000 acres 10 feet deep.
“Where the heck are you going to put it?” he asked.
He offered the option of putting it in abandoned mines in West Virginia but the transport could quadruple the cost. Barging it to the Atlantic Ocean and dumping it is another option but “good luck getting a permit for that,” Frigon said.
“It’s a lot more complicated than just dredging,” he said. “We need to sit down and look at the science and do the studies and try to understand what’s happening before we rush to judgment.
“Politicians want soundbite solutions and unfortunately nature is much more complicated than a soundbite.”
Simpson’s report, “A Better Way to Restore the Chesapeake Bay,” is available at
As for the more obscure option, David Schnare, senior fellow of energy and the environment at the Thomas Jefferson Institute of Public Policy, pointed to fostering the growth of “good algae” known as diatomes over blue-green algae which is “like a weed. It’s not on any food chain, it’s useless.”
Diatoms are part of the food chain for fish in the Bay, Schnare said, so “if you grow diatoms and don’t grow blue green algae you’re going to solve a lot of problems. Essentially what I say is ‘let’s just feed the fish.’”
Both algaes need phosphors and nitrogen to thrive but diatoms also need silicon at the same level of nitrogen and iron.
Schnare cited decades old research that offered silicon as a missing link in improving the Bay.
“This is not backyard nonsense,” he said. “This is mainline science that hasn’t been pursued.”
The most logical place to add silicon, Schnare said, is to treated wastewater as it goes into the Bay from treatment plants.
He said resuming the research would be relatively inexpensive but would need scientists to pursue it and regulators who won’t hold up the progress.
“It’s not throwing sand in the water, we’re talking high-tech well-machined micronutrients and it’s being done in India of all places and lots of other places. So why not do that if you can get a regulator to admit that this is a better way to deal with the problem?”