This report presents a conceptual model of groundwater flow and the effects of nitrate (NO3-) loading and transport on shallow groundwater quality in a portion of the Indian River watershed, eastern Sussex County, Delaware. Three-dimensional, numerical simulations of groundwater flow, particle tracking, and contaminant transport were constructed and tested against data collected in previous hydrogeological and water-quality studies.
Delaware, Maryland and Virginia have each partnered with the Bureau of Ocean Energy Management to find new sand sources using existing mapping data. As part of the federal Disaster Relief Appropriations Act of 2013, which allocated $13.6 million to the bureau, all three states will each receive $200,000 for the two-year project.
Scott Andres of the Delaware Geological Survey and Holly Michael, assistant professor of geological sciences, participated in 2011 National Ground Water Association (NGWA) Groundwater Summit and were co-organizers of the session titled "Submarine Discharge of Groundwater and Nutrients into Estuaries and Oceans," May 3, Baltimore.
The goal of this project is to develop a three-dimensional (3D) numerical groundwater flow model to evaluate the potential impacts to surface- and groundwater resulting from the disposal of treated wastewater in a portion of the Inland Bays drainage basin.
By developing a sub-regional, fresh, groundwater flow model and analyzing results, several issues will be addressed that are related to state policy, regulation revision, and proposed projects associated with land-based wastewater disposal (LBWD) in Sussex County.
Delawareâs Inland Bays in southeastern Sussex County are valuable natural resources that have been experiencing environmental degradation since the late 1960s. Stresses on the water resource include land use practices, modifications of surface drainage, ground-water pumping, and wastewater disposal. One of the primary environmental problems in the Inland Bays is nutrient over-enrichment. Nitrogen and phosphorous loads are delivered to the bays by ground water, surface water, and air.
Digital watershed and bay polygons for use in geographic information systems were created for Rehoboth Bay, Indian River, and Indian River Bay in southeastern Delaware. Polygons were created using a hierarchical classification scheme and a consistent, documented methodology that enables unambiguous calculations of watershed and bay surface areas within a geographic information system. The watershed boundaries were delineated on 1:24,000-scale topographic maps. The resultant polygons represent the entire watersheds for these water bodies, with four hierarchical levels based on surface area.
Agricultural fertilizer application, animal (poultry) waste, and wastewater disposal practices of the past 40 years have resulted in widespread nitrate contamination of ground water in coastal Sussex County, Delaware. Discharge of contaminated ground water to Rehoboth and Indian River bays is suspected of being a significant contributor to elevated nutrient concentrations in these surface water bodies, resulting in excessive phytoplankton growth and other related problems.