NEW INSIGHTS IN RESTORING THE NATION’S LARGEST ESTUARY: SCIENCE-BASED EVIDENCE FOR WATER-QUALITY IMPROVEMENTS, CHALLENGES, AND OPPORTUNITIES IN THE CHESAPEAKE BAY ECOSYSTEM

Reducing nutrient pollution has been a primary goal of the Chesapeake Bay Program since it was established in 1983. The Program is comprised of watershed states and the District of Columbia, the U.S. Environmental Protection Agency, and the Chesapeake Bay Commission and has embraced voluntary, regulatory and management initiatives to analyze and reduce pollution delivered to the Bay. However, insufficient progress and continued water quality impairments led EPA to establish the Chesapeake Bay Total Maximum Daily Load in 2010. The Bay TMDL set limits on the amount of pollutants that the nation’s largest estuary can receive and meet water quality standards.

The presentation will provide insights about water-quality response to BMPs based on synthesis of results from 40 different case studies within the Chesapeake Bay watershed to improve water quality. Three themes emerged from this research: 1) several practices are proven effective; 2) certain challenges can impede progress; and 3) practices that target the impacts of intensified agriculture and rapid population growth are needed to improve water quality outcomes. Three major BMPs are demonstrably effective in improving water quality: 1) upgrades to wastewater treatment plants (WWTPs); 2) decreases in atmospheric nitrogen deposition; and 3) agricultural nutrient input reductions. Two major challenges have impeded progress despite the implementation of BMPs: 1) delays between BMP implementation and observable water quality improvements; and 2) counteracting influences. Continuing suburbanization and intensified agriculture are driving forces of declining water quality in the Chesapeake Bay Watershed. Increased use of fertilizers, higher livestock densities, and greater impervious surface area and stormwater are major factors that can reduce BMP impact. Based on these challenges, we need to be diligent about how and where we use both proven and innovative practices to reduce pollution, and in monitoring how well they work.