Opinions Still Differ on Conowingo Role in Bay Cleanup

As Maryland Continues to grapple with ambitious, but expensive, plans to effect its cleanup goals for the Chesapeake Bay, opinions still differ on the priorities and steps ahead. Among the most debated matters is the relative importance and priority of the Conowingo Dam (and its pending federal relicensing) as part of the Bay effort. Two items on the MarylandReporter.com website refresh this debate.

An October 30 MarylandReporter.com article discussed an October 10 Maryland Public Policy Institute report which concludes that Chesapeake Bay pollution reduction efforts will fail unless the sediment and nutrient reduction caused by the Conowingo Dam is addressed.  The report, “A Better Way To Restore The Chesapeake Bay”, was authored by James Simpson. From the article:

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 [a United States Environmental Protection Agency (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 following chart from the report illustrates the nitrogen produced by different sources:

Chart 1 Nitrogen loads to chesapeake

The article also discussed the costs associated with reducing nitrogen generated by the different source and how sediment and nutrient discharges from the Dam have been increasing as the Dam appears to be reaching its capacity to trap sediment and nutrients.  The article also focused on the report’s conclusion that dredging the Dam would be cost effective in eliminating a majority of the Bay’s nitrogen and sediment pollution:

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.

Report – “A Better Way To Restore The Chesapeake Bay”

Focusing on the Conowingo Dam has been disputed by a number of environmental advocates.  An October 30 MarylandReporter.com commentary by Bay activist Tom Horton offers a counterpoint to the conclusions of the Maryland Public Policy Institute report, arguing that focusing on the Conowingo does nothing to address local pollution sources (including chicken manure), loss of forestlands, or population growth.  From the commentary:

If I could amend the federal Clean Water Act, I’d include triple penalties for polluters who spend more energy pointing to other polluters than on cleaning up their own mess.

This “we won’t act till they do” dereliction has colossally delayed action to clean up the Chesapeake, and dodging the real issues has become a prime focus of conservative politicians and rural governments in Maryland.

Until someone musters billions of dollars to dredge centuries of sediment from Pennsylvania trapped behind the giant Conowingo Dam, they whine, it makes no sense for them to spend money on their pollution.

Scientifically, this doesn’t hold water. Most of the pollution in Maryland (and Virginia) rivers comes from local sources, not the Susquehanna River; and the polluting sediment that does wash downstream from behind Conowingo in big storms, while significant, is not the bulk of the river’s environmental impact.