The EPA Chesapeake Bay Program Thursday announced estimated water quality in the tidal Chesapeake Bay has reached a near-record high.
According to preliminary data, almost 40 percent of the Chesapeake Bay and its tidal tributaries met clean water standards for clarity, oxygen and algae growth between 2014 and 2016.
This two percent increase from the previous assessment period is due in large part to a rise in dissolved oxygen in the deep channel of the Bay.
While this positive sign of resiliency in the nation’s largest estuary indicates our ecosystem has recovered from the damages sustained during Hurricane Irene and Tropical Storm Lee, water quality must improve in 60 percent of the Chesapeake Bay and its tidal tributaries if the estuary is to function as a healthy ecosystem.
Local efforts to reduce nutrient and sediment pollution have shown some success under the Chesapeake Bay’s “pollution diet,” but the challenge of putting enough conservation practices on the ground to further reduce agricultural runoff and urban runoff to local waterways remains.
The Chesapeake Bay Program partnership uses several environmental indicators to track pollution and assess aquatic health.
A suite of computer simulations called the Watershed Model is used to estimate the impact that local conservation and best management practices have had on nutrient and sediment loads.
Monitoring data collected from stations on the nine largest rivers in the watershed provide the foundation for experts to estimate the total nitrogen, phosphorus and sediment entering the Chesapeake Bay and its tidal tributaries each year, while data collected from stations in non-tidal waters allow experts to assess the aquatic response to efforts to reduce agricultural and urban runoff.
Monitoring data is also collected from a comprehensive network of hundreds of stations in tidal waters to assess changes in water quality.
Computer simulations show that best management practices are currently in place to achieve 33 percent of the nitrogen reductions, 81 percent of the phosphorus reductions and 57 percent of the sediment reductions necessary to achieve the pollution-reducing commitments of the Chesapeake Bay Watershed Agreement.
In 2016, Chesapeake Bay Program partners surpassed their phosphorus- and sediment-reducing goals.
Nitrogen reductions, however, fell short of the target for the fourth year in a row, due in large part to a gap in reported and implemented agricultural best management practices in Pennsylvania.
At the 2016 meeting of the Chesapeake Executive Council, the U.S. Department of Agriculture and U.S. Environmental Protection Agency announced their intent to increase funding, technical assistance and direction for Pennsylvania in order to increase the implementation of nitrogen controls in the Commonwealth.
Findings based primarily on monitoring data collected at nine River Input Monitoring (RIM) stations reveal inconsistent trends in pollution loads.
-- In the District of Columbia, the Potomac RIM station has experienced improving ten-year trends in nitrogen but degrading ten-year trends in phosphorus.
-- In Maryland, one station—in the Patuxent—has experienced improving ten-year trends in nitrogen and phosphorus. The Susquehanna station has experienced degrading ten-year trends in nitrogen and phosphorus; the Patuxent station has experienced degrading ten-year trends in sediment; and the Choptank station has experienced degrading ten-year trends in nitrogen, phosphorus and sediment.
-- In Virginia, both the James and the Rappahannock stations have experienced improving ten-year trends in nitrogen. The Mattaponi station has experienced degrading ten-year trends in nitrogen and phosphorus; the Pamunkey station has experienced degrading ten-year trends in nitrogen and sediment; and the Appomattox station has experienced degrading ten-year trends in nitrogen, phosphorus and sediment.
Monitoring data collected from non-tidal stations throughout the watershed show that half of the stations analyzed for nitrogen, 38 percent of the stations analyzed for phosphorus and 20 percent of the stations analyzed for sediment have experienced improving ten-year trends.
Thirty-one percent of the non-tidal stations analyzed for nitrogen, 26 percent of those analyzed for phosphorus and 37 percent of those analyzed for sediment have experienced degrading ten-year trends.
While data also show that pollution loads in 2016 remained below the long-term average, these loads did increase: between 2015 and 2016, nitrogen loads increased 12 percent to 241 million pounds, phosphorus loads increased 35 percent to 13.6 million pounds and sediment loads increased 56 percent to 2.5 million tons.
Experts attribute this rise to an increase in river flow, which itself is affected by rainfall.
Improvements in water quality will take time, and there are often lags between the implementation of best management practices and the visible effects of those practices on a particular waterway.
In January, the Chesapeake Bay Program will release the 2016-17 Bay Barometer: Health and Restoration in the Chesapeake Bay Watershed, which will explore how the entire Chesapeake Bay ecosystem and its watershed are responding to the partnership’s collective protection and restoration efforts.
For a description of activities in Pennsylvania to meet Chesapeake Bay cleanup commitments, visit DEP’s Pennsylvania’s Chesapeake Bay Plan webpage.
Reaction
Beth McGee, Chesapeake Bay Foundation Director of Science and Agricultural Policy, issued this statement: "The new findings from the CBP provide both good and bad news. It’s clear the Clean Water Blueprint is working. Our water is getting cleaner, leading to smaller dead zones and more Bay grasses and oysters. This is a testament to the strong monitoring and science that supports the Blueprint.
“But water quality still has to improve in 60 percent of the Bay, meaning that we can’t take our foot off the gas pedal. We need increased efforts from both the states and federal government. The Bay Program must be fully funded and all the Bay jurisdictions must continue to reduce pollution from agriculture and urban and suburban runoff."
For more on Chesapeake Bay-related issues in Pennsylvania, visit the Chesapeake Bay Foundation-PA webpage. Click Here to sign up for Pennsylvania updates (bottom of left column). Click Here to support their work.
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