Current plans to restore Chesapeake won’t work without Conowingo cleanup, report says

Current plans to restore Chesapeake won’t work without Conowingo cleanup, report says

View of the Conowingo Dam on the Susquehanna River in the aftermath of Tropical Storm Lee taken Sept. 12, 2011. Discharge at time of the photo was 220,000 cubic feet per second. Peak discharge for the flood was 778,000 cubic feet per second at 4 a.m.on Sept. 9, 2011. (Wendy McPherson/U.S. Geological Survey)

ABOVE: View of the Conowingo Dam on the Susquehanna River in the aftermath of Tropical Storm Lee taken Sept. 12, 2011. Photo by Wendy McPherson, U.S. Geological Survey.

By Dan Menefee


A new report from the Maryland Public Policy Institute warns that Maryland’s $14.4 billion plan to clean up the Chesapeake Bay will not satisfy an EPA mandate—because the plan ignores the Conowingo Dam as the single largest source of sediment and nutrient pollution in the Bay.

The report laments that the lion’s share of the $14.4 billion burden, $13.5 billion, is disproportionately targeted to mitigate nitrogen pollution from sewage plants, stormwater, and septic systems, which only account for 7% of all the pollution into the Bay–and will only reduce nitrogen by a negligible 2% by 2025. The mandate was established in 2010 to meet Clean Water Act standards by 2025.

“The EPA, Maryland Department of the Environment and the Chesapeake Bay Foundation got together and decided we needed to get rid of nitrogen, that nitrogen was the villain,” said James Simpson, who presented “A Better Way To Restore the Chesapeake Bay” at a forum at Washington College Tuesday. The event was sponsored by the Maryland Public Policy Institute and the Thomas Jefferson Institute for Public Policy, free-market think tanks.

“I’m not enough of an expert to know if nitrogen is that devastating, but it’s irrelevant [because] they’ve chosen to focus most of their efforts on wastewater, stormwater and septics, which as you can see are a miniscule portion of nitrogen load to the Bay,” Simpson said. “If you decide that nitrogen is the bad guy, wouldn’t you want to get rid of nitrogen in the most cost effective way, why would you want to focus on only 7% of Maryland’s [nitrogen] source.”

For an opposing point of view see Tom Horton’s commentary: ‘Don’t mess with Conowingo until you’ve cleaned up you’re act’

Chart 1 Nitrogen loads to chesapeake

Simpson admits he’s not an expert in the science of the cleanup plan and bases his argument solely on the science Maryland officials have relied on to meet the EPA mandate. His experience as an economist and budget analyst for the White House Office of Management and Budget drives his argument that most of the $14.4 billion has been steered to the least effective strategies. He worked at the White House office during the administrations of Presidents Ronald Reagan and George H.W. Bush.

Simpson’s report claims dredging the sediment trapped behind the Conowingo is a more cost-effective method to reduce pollutants in the Bay.

MDE Secretary did not attend event

Maryland Department of the Environment Secretary Robert Summers was scheduled to appear at the event but cancelled suddenly. Simpson characterized Summers’ absence as “conveniently taking a powder.”

MDE Communications Director Jay Apperson said Summers cancelled his appearance for “personal reasons.” Christopher Summers, president of the Maryland Public Policy Institute, said the department could not offer a replacement for Summers.

Major costs for minimal nitrogen impact

The plan estimates a cost of $3.7 billion, or $3,217 per pound, to reduce nitrogen from septic systems–and yields only a 0.3% reduction of nitrogen through 2025. Mitigating nitrogen loads from stormwater runoff and sewage plants will cost $3,442 and $620 per pound respectively—contributing just 1.7% in nitrogen reduction.

pic 2

The total amount of nitrogen reduction in Maryland through 2025 comes to 5,389 tons, just 359 tons annually, yet the annual nitrogen discharge from the Susquehanna through the dam is 71,000 tons–if no storm events occur.

“[Conowingo] provides more [nitrogen] in a year than we’re going to focus $14.4 billion on from now until 2025 to get rid of,” Simpson said. He said Tropical Storm Lee in 2011 alone dumped 42,000 tons of nitrogen into the Bay.

Simpson said the states in the Bay watershed will collectively spend $40 billion to reduce a total 34,000 tons by 2025, which is less than half the amount that flows through the Conowingo annually.

“So I would ask the Maryland Department of the Environment, the governor and a lot of the legislators why they’re willing to spend $40 billion, and in our case $14.4 billion, for an effort that will accomplish zero,” Simpson said.

Dam discharges increased

The discharges from Conowingo have increased as the dam has gradually lost its ability to trap sediment and nutrients since its construction in 1928. Currently there is an estimated 174 million tons of sediment behind the dam with 3 million more added each year, which Simpson says has been largely ignored in the EPA mandate.

Conowingo hemorrhaged 19 million tons of sediment during Tropical Storm Lee in 2011 and amounted to 40% of the total discharge from 2002 to 2011, according to a report from the U.S. Geological Survey in 2012 on Lee that Simpson cites in his report. The report warned that sediment discharges could increase by 250% once the dam loses the ability to trap sediment.

Robert M. Hirsch, the author of the report on Lee, told Maryland Reporter that the 2010 EPA mandate overestimated the remaining storage capacity of the dam.

“The [2010 mandate went] on the assumption that Conowingo had a considerable ability to trap sediment and phosphorus, so they’re going to have to be redone at some point,” Hirsch said.

Simpson said the devastation to the oyster population in the northern part of the Bay is largely attributed to millions of tons of sediment from the Conowingo from regular discharge and storm events since the 1970s.

Oyster harvest pic 3

“The sediment covers the whole upper bay in inches and prevents oysters from reproducing,” he said, and pointed to a chart that showed a massive decline in the oyster harvest in the upper Bay since Hurricane Agnes in 1972. He said with each major event that oyster population never rebounds and sinks further into decline.

“Right now we are at 183 bushels a year in the upper part of the Bay,” Simpson said. “That is essentially a dead oyster harvest, a dead oyster fishery.”

pic 4Dredging dam would reduce nutrient-laden sediment discharge

Simpson’s report claims the cost of dredging the dam would run $48 million a year to remove two million tons of nutrient laden sediment and the additional disposal costs could be defrayed by using the sediment to produce “lightweight aggregate,” a commonly used building material. Dredging could also eliminate or reduce the $43 million Maryland Port Administration spends each year to dredge the shipping channels.

“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% of the Bay’s nitrogen,” the report said.

Hirsch said vacant quarries near the dam could be safely used to dispose of the sediment.

“The good news is there’s all these empty quarries within a few miles of the dam,” Hirsch said. “These are places where it could safely be disposed of, it’s actually very fortuitous that you have all the quarries.”

Here’s a 17-minute video of Simpson’s presentation.

Riverkeeper: current plan helps local rivers and streams

Simpson’s report was challenged from the audience by Chester Riverkeeper Isabel Junkin who said the $14.4 billion was aimed at cleaning local waterways where local problems exist.

“When we talk about spending that money it’s to impact our local rivers and streams,” she said. She said the sediment plumes from storm events are not impacting local streams or rivers.

“The water quality in our local rivers is actually being impacted by our local problems,” she said.

Simpson responded that “a lot of what is being spent for septic in a lot of areas is just not necessary.”

Simpson pointed out that the EPA mandate can be challenged by states and counties.

“In most places people just don’t know the law,” Simpson said. “You can challenge this [but] you have to go to EPA and demand it, they have to sit down and negotiate, and that’s one of the things we should be doing to stop this madness.”

About Maryland’s cleanup plan:

The 2010 EPA mandate was the result of a lawsuit won by Chesapeake Bay Foundation that legally bound the EPA to enforce the 1972 Clean Water Act.  Under a consent decree, states in the Chesapeake Watershed, from New York to Virginia, were required to adopt Water Implementation Plans that reduced the Total Maximum Daily Load of sediment, nitrogen and phosphorus into the Bay.

Maryland drafted its plan by requiring local governments to enact local WIPs–on the idea that runoff into the Bay from local streams and tributaries should be the responsibility of local governments to mitigate through regulations and taxing authority.

About The Author

Dan Menefee

Daniel is a Reporter, If you have additional questions or comments contact Daniel at:


  1. Ralph Comegna

    mr Simpson can you please help me to understand how we can get ahead of this problem if we can only dredge 2 million tons per year but the fill rate is 3 million tons per year. I realize that getting rid of 2 is better than adding the 3 with no progress but what could be done to say remove higher tonnage per year? Is it even possible?

  2. USVoter

    The facts in the report come from a variety of sources and are pretty clearly showing the need for doing something with Conowingo. Read it – the sediment coming through that dam annually is 7x what the entire Agriculture sector is doing, and nearly 10x what wastewater treatment plants add.
    I was particularly struck by the note that Conowingo was 120 feet deep when it was built in 1928 – it is 20 feet deep now because the rest is filled in with sediment. If that does not tell you they need a dredging and disposal program then nothing will.
    We would be a lot better off spending money up there – clean water flowing into the top of the bay can’t do anything but help it.

    • bradknopf

      Sediment is filling our creeks and rivers, upstream of the bay, in rivers like the Magothy, the Severn, the Patuxent, the Potomac. It is coming from exposed soil. It is not coming from wastewater treatment plants to any extent. The Conowingo dam has nothing to do with this. Nobody is saying we should do nothing about the dam, but too many charlatans are saying we should not fix the real problems, we should instead blame it on the dam.

      • USVoter

        Oh I am not saying that there are not other sources of pollution feeding the bay, but it would seem prudent to tackle one big obvious source of sediment right off. Lets face it – we are not going to dam every Maryland creek and stream feeding the bay, and if you have sediment numbers from other rivers feeding the bay, I’d love to see them.
        One thing I do know is that the bay has been getting progressively worse from north to south – treating the susquehanna sediment as a big priority to get grasses (and may even oysters) back in the middle and northern areas of the bay doesn’t seem to be a bad idea. I’m not saying that money doesn’t need to be spent in other areas as well. What I am saying is that from the numbers in that report (so far unrefuted) – Conowingo would seem to be an obvious choice as a project for some of the dollars we are paying to clean up the bay.

        • bradknopf

          Damming is not the answer, it’s best to combat runoff of chemicals, sediment and nutrients at the source-suburbia. Actually the bay is getting worse from the middle, not the top. Suburban and Urban runoff off is by far the most damaging. There are no algae blooms in mid or upper bay. There are no chemical impairments north of Baltimore. Check out any of the many impairment maps-none of them list the Susquehanna flats as critical. On the contrary, the flats are thriving with SAV and native fish.The problem with the “fix the dam” movement is that it is an either/or proposition. Proponents are pushing it as an excuse to ignore the real problem by blaming it on other states, thereby stalling the entire process. It is a smokescreen, plain and simple.

  3. bradknopf

    This is a seriously flawed and biased article from a right wing think tank. The name Maryland Public Policy Institute alone is ridiculously misleading. They are neither public nor nonpartisan. Check them out. One particularly galling smoke screen is the oyster decline graph. They show a tiny fragment, as if the historic decimation began in 1970? He only missed by one hundred years. Tom Horton’s article referenced at the end as an opposing viewpoint is a good read

    • James Simpson

      No, actually it is an article I wrote way before MPPI picked it up. It takes all of its statistics directly from the MD WIP, MD legislature, the EPA and the Chesapeake Bay Program. Tell me where it is flawed and biased. The only flaws and bias are built into the state policy, which imposes extreme costs on rural counties for a speck of pollution cleanup in return. You seriously need to check yourself and your facts.

      • bradknopf

        As I stated, the fragment of the oyster decimation timeline you portray is purposefully deceptive, implying that a storm in the 70s caused their demise. Your nitrogen chart shows a number of sources that do not add up to the total. None of your arguments account for all the damage UPSTREAM in every Maryland river that leads to the Bay. I suppose Pennsylvania caused all that? Apparently it never occurred to you that the density of population and proliferation of CAFOs is astronomically higher on our side of the dam. You repeated assure us that you’re no expert in this field, let’s leave it at that.

        • James Simpson

          Deliberately deceptive? Why on earth would anyone do that? Maybe you do, I don’t. What would be the point? Leftists are always accusing others of what they do. Leave it at that.

          I left off the rest of the 20th century because the average annual take going back to about 1925 was 2.5 million bushels, varying by about a million up or down over time but with an essentially flat trend. I did the math. You didn’t. I saw no purpose in going back that far but could have. See “Oyster Harvests and the Repletion Program.” Further back into the 1800s it was much higher but declined due to overfishing. Don’t accuse me of being deliberately deceptive. I am not so. There is no point. You may be ignorant, not sure if that is deliberate or not. The pollution in streams certainly needs to be addressed, but does not require $3.2 billion, nor does it require BAT. It requires the appropriate T, which I have been told is not being used. And that focused on those streams that need it. Not the entire state. There is an entirely separate agenda re septics that the governor is pursuing. I have seen his interoffice memos that prove it. You haven’t, unless you’re one of his trolls out here to spread disinformation. Knock it off. If you want to have a genuine discussion, then start with facts and dispense with the ad hominem.

          • bradknopf

            Average twentieth century oyster take was flat? I’m not even going to continue discussing this with you. You are not just mistaken, you are purposely deceiving.

          • James Simpson

            Of course you won’t. I cited the source. Quit with the false accusations. The only one being purposefully deceitful is you.

          • bradknopf

            Now that the election is over, actual scientists and the media have publicly dismissed your ilk’s lies about Conowingo being the primary problem with the Bay’s water quality. Just what we needed, a steaming pile of lobbyist fertilizer.

          • James Simpson

            Follow the money. None here. $Millions or even $billions to be had from the “scientific” establishment catering to the corrupt soon-to-be ex governor. But you won’t because you are the troll. Who pays you??

  4. bob gallagher

    The “report” reads like the work of a recycled climate change denier.

    • James Simpson

      Then you obviously didn’t read it.

  5. Michael

    I’m no expert (either) but…

    What about the dynamic equilibrium I have heard about at the dam? That wasn’t even mentioned??

    • John Mann

      The loss of trapping capacity is referenced a few times. It’s the same thing.

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