Delaware Geological Survey is installing two new research and monitoring wells for northern Kent County and southern New Castle County. The project, which will take about two years, calls for eight new wells, including Smyrna, the Woodland Beach, Middletown and Townsend areas, two sites in Blackbird State Forest, Cedar Swamp and a location near Odessa National Country Club.
Delaware Geological Survey improving groundwater monitoring efforts with new wells, sampling. Scientists are digging for answers about the amount and quality of water available underground in central Delaware, where ongoing development will put increasing demands on water supplies in the coming decade.
The Delaware Geological Survey (DGS) is installing 7,700 feet of wells at eight sites in southern New Castle and northern Kent counties to improve groundwater-monitoring efforts, supported by a $600,000 grant from the Delaware Department of Natural Resources and Environmental Control (DNREC). Groundwater is the primary source of drinking water south of the Chesapeake and Delaware Canal, and populations there are projected to continue expanding.
To understand the effects of projected increased demands on groundwater for water supply, a finite-difference, steady-state, groundwater flow model was used to simulate groundwater flow in the Coastal Plain sediments of southern New Castle County, Delaware. The model simulated flow in the Columbia (water table), Rancocas, Mt. Laurel, combined Magothy/Potomac A, Potomac B, and Potomac C aquifers, and intervening confining beds.
An explanation is suggested for the origin of thin, laterally persistent pebble beds commonly found in the Columbia Formation of Delaware. The pebbles in the thin beds are usually less than 16 mm in diameter, well rounded, spherical, and composed mainly of resistant material: chert, vein quartz, and quartzite. The process thought to be responsible for the origin of these beds is a combination of erosion and transport of sand and pebbles in suspension by highly turbulent streams resulting in selective deposition of pebbles in thin, laterally persistent layers.
Columbia sediments in the Middletown-Odessa area are composed of boulders, gravels, sands, silts and clays. These sediments are exposed in four gravel pits where their structures and textures were studied. Subsurface geology was interpreted on the basis of the well-log data from 40 holes drilled in the area of study. Columbia sediments were laid upon a surface made up of the greensands of the Rancocas Formation (Paleocene â Eocene age). The contact between the Rancocas and Columbia Formations is an erosional unconformity.
Geology and hydrology of the Middletown-Odessa Area, Delaware.
This map shows the surficial geology of New Castle County, Delaware at a scale of 1:100,000. Maps at this scale are useful for viewing the general geologic framework on a county-wide basis, determining the geology of watersheds, and recognizing the relationship of geology to regional or county-wide environmental or land-use issues. This map, when combined with the subsurface geologic information, provides a basis for locating water supplies, mapping ground-water recharge areas, and protecting ground and surface water.
Geology map showing the sub-surface geology of the Middletown-Odessa Area, Delaware.