The U.S. Environmental Protection Agency (EPA) established a comprehensive “pollution diet” that they imposed on Virginia and the other Bay states to restore clean water in the Chesapeake Bay and the region’s streams, creeks and rivers. We have now reached the mid-point in the program and our targets and actions are being revised to ensure we meet the goal of a healthy Chesapeake Bay.
This month James Davis-Martin of the Virginia Department of Environmental Quality (DEQ) spoke to the Conservation District Directors at our annual meeting to update us on what’s coming down the road in the EPA mandated pollution diet to.
First the good news. For the past 5 years EPA has worked with DEQ and the other states to improve the model used to manage and measure progress in meeting our pollution diet goals. The EPA has improved the model and resolved more than 100 issues that were identified by the states. We are now moving to Phase 6 of the model which has a resolution of 1 meter in land use cover. The newest version of the model also has integrated the municipality land use data collected over the last 8 years, updated the BMP (best management practices for agriculture) list and effectiveness. This has resulted in the highest correlation of measured water quality data with the model output.
The improved model and the data collected have resulted in a revision of the Bay assimilative capacity, increasing slightly the amount of nitrogen and phosphorus that the Bay can tolerate. That simply means that the ability of the Chesapeake Bay to dilute and absorb pollutants without harmful effects like dead zones and toxic algae is a little higher than the EPA initially thought. These in turn change the Virginia targets for nitrogen, phosphorus and sediment goals for the final Phase III of the Watershed Implementation Plans (WIPs). By the end of this month DEQ will have the final pollution target goals for development of the Phase III WIP which is due to EPA in 2018.
That is the end of the good news. Even with that adjustment we still have to meet more stringent goals. Going forward the states will have to account for population and economic growth in developing their Phase III WIPs. Because all the states are forecasting growth they will have to achieve their 2025 target nutrient and sediment numbers with more people, roads and economic activity
In addition, the Phase III WIPs from all the states must account for the additional loads delivered to the Chesapeake Bay due to the Conowingo infill. When the EPA allocated the nitrogen, phosphorus and sediment reductions among the Chesapeake Bay states, the EPA believed that the Conowingo Dam would continue to trap polluted sediment for an additional quarter of a century. Subsequent studies by the U.S. Geological Survey (USGS) and the Army Corps of Engineers found that the Conowingo Dam is already 95% full and will be full and cease protecting the bay from sediment within the next year or two. Without the Conowingo removing sediments containing nitrogen and phosphorus before the waters reach the Chesapeake Bay that contamination load will increase and must be accounted for or removed by other action.
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| The 2017 current load plus the additions must be reduced to the 2025 level goal |
Finally, the states will now have to account for the impacts of climate change and sea level rise in developing their Phase III WIPs. The models for climate change are forecasting more rain in the region due to climate change. We will not run out of water; however, more rain brings additional stormwater flows that can increase runoff. All these additions must be accounted for in the Phase III of the WIPs and Virginia and the other states much reduce their loads to the 2025 Assimilative Capacity as seen above.
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