In the United States more than 3.5 billion tons of solid waste are generated annually. Of this, more than 2 billion tons are agricultural waste, such as manure and crop waste. Almost 300 million tons are generated by commercial and industrial activities and municipalities, and another 1.1 billion tons are attributed to various mining operations (Vaughan, 1969). Increasing amounts of solid waste have had detrimental effects on environmental quality. It has become necessary to reprocess and reuse some, and to provide safe and environmentally acceptable ways of disposing of the remaining waste in properly constructed landfills. Pollution brought about by improperly constructed landfills may be very severe. For example, the contaminants generated by the waste at the old, abandoned Army Creek Landfill, New Castle County, Delaware, were so widespread that the situation received national attention. General and sincere concern expressed by many citizens of our State has prompted the Delaware Geological Survey to prepare this report. The report explains the functioning of a landfill, problems improperly constructed landfills may cause, and the geologic and hydrologic aspects that have to be considered in selecting a suitable disposal site for solid waste. The report does not contain discussions of other important factors, such as social impact, transportation, and specific health hazards, that must also be considered.

This report provides initial research results of a storm-water and base-flow sampling and analysis project conducted by the University of Delaware College of Marine Studies (CMS) and the Delaware Geological Survey (DGS). Base-flow samples were collected from six tributary watersheds of Delaware’s Inland Bays on 29 occasions from October 1998 to May 2000. Water samples were filtered in the field to separate dissolved nutrients for subsequent analysis, and a separate sample was collected and returned to the laboratory for particulate nutrient determinations. On each sampling date, temperature, conductivity, pH, and dissolved oxygen concentrations were determined at each sampling station. Stream discharge measurements at each of these sites were made by the U.S. Geological Survey (USGS) under a joint-funded agreement with the Delaware Department of Natural Resources and Environmental Control (DNREC) and the DGS. Together, the nutrient and discharge data were used to determine the total and unit (normalized to watershed area) nutrient loading from base flow to the Inland Bays from each of these watersheds on a quarterly and annual basis. At the same six stations, storm water was collected during eight storms from May 1999 to April 2000. Storm-water loadings of nutrients from each watershed were calculated from the concentrations of nutrients in water samples collected at fixed time intervals from the beginning of the storm-water discharge period until recession to base flow. These data provide DNREC with a more complete picture of the seasonal dependence of nutrient loading to the Bays from which to establish goals for total maximum daily loads in the Inland Bays watershed.

Southern New Castle County has a land area of 190 square miles in north-central Delaware. It is predominantly a rural area with a population of about 9,000 people who are engaged chiefly in agriculture. By and large, the residents are dependent upon ground water as a source of potable water. This investigation was made to provide knowledge of the availability and quality of the ground-water supply to aid future development. The climate, surface features, and geology of the area are favorable for the occurrence of ground water. Temperatures are generally mild and precipitation is normally abundant and fairly evenly distributed throughout the year. The topography of the area is relatively flat and, hence, the streams have low gradients. The surface is underlain to a considerable depth by highly permeable unconsolidated sediments that range in age from Early Cretaceous to Recent.