EASTON — The Chesapeake Bay’s ecosystem is starting to respond to protection and restoration efforts following a significant drop in the amount of nutrient and sediment pollution between 2014 and 2015, according to data from the Chesapeake Bay Program and the U.S. Geological Survey.
The pollution reductions are largely credited to dry weather and below-normal river flow, but experts noted local efforts to reduce pollution — like best management practices, lowering vehicle and power plant emissions and reducing runoff from farmland — also play a role.
Excess nitrogen, phosphorus and sediment are recognized at top contributors to the Bay’s poor health.
According to the Chesapeake Bay Program, excess nutrients, like phosphorus and nitrogen, in the Bay’s water can fuel the growth of algae blooms that lead to long-duration, low-oxygen “dead zones” in deep water and short-duration “mortality moments” in shallow water. Sediment can block sunlight from reaching underwater grasses and suffocate shellfish.
Each year, as per the Chesapeake Bay Watershed agreement between Maryland, Delaware, Virginia, West Virginia, Pennsylvania, New York and the District of Columbia, jurisdictions involved in the Bay pollution reduction efforts report the best management practices — a type of on-land water pollution control — they had implemented that year, said Nick DiPasquale, director of the Chesapeake Bay Program.
The Chesapeake Bay Program then estimates how the best management practices, “whether it’s wastewater, stormwater, agriculture runoff and septic systems,” translate into pollution reduction, DiPasquale said.
The Chesapeake Bay Program found the estimated nitrogen, phosphorus and sediment loads to the Bay were below the long-term average in 2015.
Between 2014 and 2015, nitrogen loads fell an estimated 25 percent, phosphorus loads fell 44 percent and sediment loads fell 59 percent.
Water quality is measured in three parameters — the amount of dissolved oxygen in the water, water clarity or underwater grass abundance, and algae growth. According to the Chesapeake Bay Program, an estimated 37 percent of the tidal Chesapeake met water quality standards between 2013 and 2015, which marks about a 10 percent improvement from the previous assessment period.
According to the Chesapeake Bay Program, the reduction in pollution is largely attributed to favorable weather. More rain will increase river flow and push pollution into the Bay. River flow was below normal in 2015, but it was not a drought year, according to the Chesapake Bay Program.
“In the past, what we’ve seen is improvement in a lot of these indicators following several years of drought conditions,” DiPasquale said. “The University of Maryland analyzed the data and clearly indicates what we’re seeing now is significant improvement in a number of indicators following a period of time with normal or just below normal rainfall, and to them that ... is a departure from what we’ve seen in the past, and it is a very positive result.”
Long-term declines in pollution loads can be attributed to on-the-ground pollution-reduction practices, according to the Chesapeake Bay Program.
But, Scott Phillips, U.S. Geological Survey’s Chesapeake Bay coordinator, said continued improvement in water quality will take time, mainly due to the lag between the implementation of a conservation practice and the visible effect of that practice on a particular waterway, particularly when the conservation practices target ground water that could take years or decades to get to the Bay or its tributaries.
The U.S. Geological Survey monitors pollution loads from nine rivers in the Bay watershed, and has found varied results for nitrogen, phosphorus and sediment, Phillips said.
He said some factors that positively impacted the results are upgrades to wastewater treatment plants, efforts to reduce agriculture fertilizer runoff and from nitrogen air emission reductions efforts.
But, two main factors of worsening conditions are impacts from development and excess manure on agricultural lands. Maryland is currently undergoing a large effort to reduce excess phosphorus pollution from Eastern Shore chicken farms with the gradual implementation of the state’s Phosphorus Management Tool.
This past summer, the U.S. Environmental Protection Agency released two-year milestone assessments for the jurisdictions involved in Bay cleanup, and found that, in total, all the jurisdictions are 31 percent of the way toward the ultimate pollution reduction goal for nitrogen, 81 percent for phosphorus and 48 percent for sediment.
Practices to reduce pollution by 100 percent of the goal are required to be implemented by the jurisdictions by 2025, although Phillips said it would take time for those results to come through, due to the lag time associated with implementing pollution reduction practices.
In response to the water quality news released Wednesday, Sept. 21, by the Chesapeake Bay Program and U.S. Geological Survey, the Chesapeake Bay Foundation’s Vice President Kim Coble said it’s encouraging that as pollution drops, the Bay responds, pointing to increases in Bay grasses and better water clarity as crucial components of Bay restoration.
“We applaud the efforts the states, farmers, local governments, and citizens have taken to reduce pollution,” Coble said.
However, Coble noted that weather played a key role in that pollution reduction, “and that is something we can’t county on every year.”
“Efforts to meet the 2017 goals are mixed. Maryland and Virginia are largely on track to meet their commitments, but Pennsylvania is far behind,” Coble said. “The U.S. Department of Agriculture and the (Pennsylvania Gov. Tom) Wolf administration must significantly increase investments in five, south-central Pennsylvania counties as the most efficient, and cost-effective ways of jumpstarting the lagging clean-up efforts.”
“When the Bay Program’s Executive Council meets next month, all eyes will be watching to see what they do to help Pennsylvania get back on track,” she said.