USGS Science⌕ Search

Geology topics

L. M. Voronin

Publications and source records attributed to L. M. Voronin.

6 recordsLinked to original sources
USGS1996

Evaluation of saltwater intrusion and travel time in the Atlantic City 800-foot sand, Cape May County, New Jersey, 1992, by use of a coupled-model approach and flow-path analysis

Regional and subregional ground-water-flow models were coupled, and the output was analyzed by a particle-tracking method. The results were then used to assess the effects of ground-water withdrawals on the flow of saltwater in the Atlantic City 800-foot sand in Cape May County, New Jersey, and to estimate the travel time from areas in which the chloride concentration of the ground water exceeds 250 milligrams per liter to the county's nearest public supply wells. First, a quasi-three-dimensional finite-difference computer model of freshwater and saltwater flow that simulated regional ground-water flow through the unconsolidated materials underlying the New Jersey Coastal Plain was used to estimate flow at the boundaries of the subregional study area. The results of the regional simulation were used as input to a second quasi-three-dimensional finite-difference model that was used to simulate flow in the subregion, the Atlantic City 800-foot sand in Cape May County. The results of the simulation of flow in the subregion were analyzed by a semianalytical particle-tracking method to estimate ground-water flow paths and travel time of ground water from areas in which chloride concentrations exceed 250 milligrams per liter to public supply wells located at Stone Harbor, New Jersey. Ground-water withdrawals from the Atlantic City 800-foot sand were assumed to be equal to those reported for 1991. Results of the analysis indicate that the time required for saltwater to reach the public supply wells is on the order of hundreds of years. These results, however, are based on the assumptions that the aquifer is homogeneous. The presence of zones of high permeability in the aquifer could reduce the predicted travel times of the saltwater from its present location to the supply wells. Travel times also could be reduced if ground-water withdrawals increase.

New Jersey↗
USGS1996

Hydrogeology and simulation of ground-water flow, Picatinny Arsenal and vicinity, Morris County, New Jersey

Ground-water flow in glacial sediments and bedrock at Picatinny Arsenal, N.J., was simulated by use of a three-dimensional finite-difference ground- water-flow model. The modeled area includes a 4.3-square-mile area that extends from Picatinny Lake to the Rockaway River. Most of the study area is bounded by the natural hydrologic boundaries of the ground-water system. eophysical logs, lithologic logs, particle-size data, and core data from selected wells and surface geophysical data were analyzed to define the hydrogeologic framework. Hydrogeologic sections and thickness maps define six permeable and three low-permeability layers that are represented in the model as aquifers and confining units, respectively. Hydrologic data incorporated in the model include a rate of recharge from precipitation of 22 inches per year, estimated from long-term precipitation records and estimates of evapotranspiration. Additional recharge from infiltration along valleys was estimated from measured discharge of springs along the adjacent valley walls and from estimates of runoff from upland drainage that flows to the valley floor. Horizontal and vertical hydraulic conductivities of permeable and low-permeability layers were estimated from examination of aquifer-test data, gamma-ray logs, borehole cuttings, and previously published data. Horizontal hydraulic conductivities in glacial sediments range from 10 to 380 feet per day. Vertical hydraulic conductivities of the low-permeability layers range from 0.01 to 0.7 feet per day. The model was calibrated by simulating steady-state conditions during 1989-93 and by closely matching simulated and measured ground-water levels, vertical ground-water-head differences, and streamflow gain and loss. Simulated steady-state potentiometric- surface maps produced for the six permeable layers indicate that ground water in the unconfined material within Picatinny Arsenal flows predominantly toward the center of the valley, where it discharges to Green Pond Brook. Beneath the upper confining unit, ground water flows southwestward, down the valley. Between First Street and Farley Avenue, the upper confining unit pinches out near the valley walls, resulting in a major input of water to, and causing a local potentiometric high in, the underlying aquifer layers. Ground-water-flow directions southwest of the southern arsenal boundary are predominantly to the Rockaway River.

New Jersey↗
USGS1987

Ground-water-withdrawal and water-level data used to simulate regional flow in the major coastal plain aquifers of New Jersey

The report documents groundwater withdrawal and level data for the major aquifers of the New Jersey Coastal Plain. These data have been used in the Regional Aquifer System Analysis flow model of 10 major aquifers in the New Jersey Coastal Plain. Groundwater withdrawal data from more than 1,400 wells are tabulated by year for 1956 through 1980. Total yearly withdrawals for 171 public supply and industrial purveyors for 1918 through 1955 are documented. Best estimates are given for percentages of total withdrawals by aquifer for the 1918 through 1955 data. Groundwater withdrawal data is also tabulated yearly from 1918 through 1980 by county for each aquifer. Long-term hydrographs for 89 Coastal Plain wells provide information on water level fluctuations over time. Potentiometric maps showing earliest recorded water levels in Coastal Plain aquifers delineate prepumping conditions. Groundwater withdrawals from the Coastal Plain have increased from less than 50 million gal/day in 1918 to more than 350 million gal/day in 1980. In response to these increased withdrawals, groundwater levels have been steadily declining. In some areas where wells once flowed freely, water levels are now 100 to 200 ft below land surface. (USGS)

Water-Resources Investigations Report↗
USGS1984

Water-quality data for aquifers in east-central New Jersey, 1981-82

Data are presented in tables for 238 wells representing nine aquifers underlying the New Jersey Coastal Plain. Approximately two-thirds of these wells are screened in the unconfined Kirkwood-Cohansey aquifer system, the principal source of groundwater in the study area. In addition, seven local streams were sampled in their headwaters under base flow conditions. Field measurements include water temperature, specific conductance, pH, and alkalinity; laboratory determinations include common inorganic ions, nutrients, trace metals, dissolved organic carbon, and volatile organic compounds. Other tables include lithology and hydrologic characteristics of geologic units, well-construction data, and median and extreme values of constituents in water of the Kirkwood-Cohansey aquifer system. A plate shows all sampling sites and presents three hydrogeologic sections delineating subsurface relationships. (USGS)

Open-File Report↗