The state-federal Chesapeake Bay Program partnership recently updated its nutrient reduction goals for 2025 based on improved information, new science and updated computer modeling.
The figures in this table — Chesapeake Bay Nutrient Trends and Goals — show, in pounds, computer-estimated nutrient “loads” reaching the Chesapeake from each major “sector” in each state.
The figures reflect 1985 levels, which were around the time when nutrient control efforts began; 2009, which is the baseline for measuring efforts since the Chesapeake Bay Total Maximum Daily Load; estimated progress at the end of 2017; and the 2025 cleanup goal for each state. Load changes between 1985, 2009 and 2017 reflect the estimated impact of new urban and agricultural runoff control practices, upgrades to treatment plants, and land use changes.
Nutrients are divided into the major sectors that generate nitrogen and phosphorus. They include:
- Agriculture, which covers all forms of farming, including large concentrated animal feeding operations, croplands and low-intensity pastures.
- Urban Runoff, which reflects stormwater from all urbanized lands, including those covered under stormwater permits, as well as development outside areas covered by permits where runoff is unregulated.
- Wastewater, which includes discharges from treatment plants and combined sewer overflows, as well as any industries that discharge nutrients.
- Septic, which includes septic systems and other small on-site treatment devices.
- Natural, which includes forests (including harvested forest lands), wetlands, streambanks and other largely natural areas. Many of the “natural” nutrient sources are largely uncontrollable.
As states develop new watershed implementation plans in the coming months, they will set new sector goals for 2025, which will be used by the EPA to help track progress toward overall goals, as well as more local targets.
These figures do not include additional nutrient reductions that will be needed to offset the impacts of anticipated growth, climate change and increased nutrients that result from the filling of the reservoir behind the Conowingo Dam on the Susquehanna River.