DGS staff member A. Scott Andres made a presentation “Results of selected UD nutrient monitoring projects in the Nanticoke River watershed” at the inter-agency meeting Chesapeake basin water quality data, trends, and interpretations held August 11, 2016 at the Delaware Department of Agriculture in Dover. Over 30 participants from multiple Delaware and federal agencies and the Nanticoke Watershed Alliance gathered to hear seven talks that detailed improvements in water quality and habitat in Chesapeake Bay and results of watershed studies that identified challenges to improving environmental quality in several tributary watersheds.
The DGS presentation, co-authored by CEOE faculty member Bill Ullman and current and former post-doctoral researchers Yoana Voynova and Chris Main, summarized results of two projects and linked DGS efforts in groundwater modeling to observations in the Nanticoke. The first project is summarized in DGS Open File Report No. 46 “Storm-Water and Base-Flow Sampling and Analysis in the Nanticoke River Watershed: Preliminary Report of Findings 2002-2004,” and the second is “Nanticoke at Bridgeville Project,” which was conducted between 2012 and 2015. These projects found that nitrate-nitrogen is being delivered to streams almost exclusively in dissolved form by baseflow groundwater discharge and that phosphorus in the River is largely transported during storms and in association with mineral and organic sediment. Results from DGS Report of Investigations No. 49 “Simulation of Groundwater Flow and Contaminant Transport in Eastern Sussex County, Delaware with Emphasis on Impacts of Spray Irrigation of Treated Wastewater” were compared to long-term water quality monitoring in the Nanticoke River to illustrate the relationships between long-term build up and long-term decay of a nitrate reservoir in groundwater.
The meeting included a wrap-up discussion to summarize key lessons learned as well as remaining challenges to understanding and controlling pollutant inputs. One key challenge that will require extensive continuing effort is to find effective means of communicating the long-time scales that will be needed to see the full impacts of the billions of dollars that have been spent on improving wastewater treatment, stormwater management, and agricultural practices.