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G. G. Patterson

Publications and source records attributed to G. G. Patterson.

10 recordsLinked to original sources
USGS2000

Contaminants and drinking-water sources in 2001: Recent findings of the U. S. Geological Survey

As the Nation's principal earth-science agency, the U.S. Geological Survey (USGS) studies numerous issues related to contamination of drinking-water sources. The work includes monitoring to determine the spatial and temporal distribution of contaminants; research to determine sources, transport, transformations, and fate of contaminants, and assessments of vulnerability. Much of the work is conducted in cooperation with the U.S. Environmental Protection Agency and other Federal, State, Tribal, and local governments, to help provide a scientific basis for resource management and regulation. Examples of recent results are presented for two broad categories of drinking-water projects: occurrence studies, and source-water assessments.

Open-File Report↗
USGS1996

Sediment transport and deposition in Lakes Marion and Moultrie, South Carolina, 1942-85

Lakes Marion and Moultrie, two large reservoirs in the South Carolina Coastal Plain, receive large inflows of sediment from the Santee River. The average rate of sediment deposition for both lakes during the period 1942-85 was about 0.06 inch per year, or about 800 acre-feet per year. The rate during 1983-85 was about 0.037 inch per year, or about 490 acre-feet per year, reflecting the decreasing trend in sediment inflow. This is a reversal of a trend toward increasing suspended- sediment concentrations in streams that were caused by farming practices in the southern Piedmont from about 1800 to about 1920. Only a small part of the eroded sediment has been carried out of the Piedmont, but the remaining sediment is becoming less available for transport. Sediment deposition is concentrated in several areas of upper Lake Marion where the velocity of the incoming water decreases significantly. Beds of aquatic macrophytes appear to encourage deposition which, in turn, creates favorable habitat for the plants. The rate of sediment accumulation in Lakes Marion and Moultrie averaged 650,000 tons per year during 1983-85, reflecting a trap efficiency of 79 percent of the total sediment inflow of 825,000 tons per year. Thickness of post-impoundment sediment varies from about 11 feet near the mouth of the Santee River in Lake Marion to 0 feet in Lake Moultrie near Bonneau. Sediments in Lake Marion tend to have finer texture and higher contents of organic matter, nutrients, and trace metals than those in Lake Moultrie.

North Carolina, South Carolina↗
USGS1995

Retention time and flow patterns in Lake Marion, South Carolina, 1984

In 1984, six dye tracer tests were made on Lake Marion to determine flow patterns and retention times under conditions of high and low flow. During the high-flow tests, with an average inflow of about 29,000 cubic feet per second, the approximate travel time through the lake for the peak tracer concentration was 14 days. The retention time was about 20 days. During the low-flow tests, with an average inflow of about 9,000 cubic feet per second, the approximate travel time was 41 days, and the retention time was about 60 days. The primary factors controlling movement of water in the lake are lake inflow and outflow. The tracer cloud moved consistently downstream, slowing as the lake widened. Flow patterns in most of the coves, and in some areas along the northeastern shore, are influenced more by tributary inflow than by factors attributable to water from the main body of the lake.

South Carolina↗
USGS1987

Regional ground-water discharge to large streams in the upper coastal plain of South Carolina and parts of North Carolina and Georgia

Base flow was computed to estimate discharge from regional aquifers for six large streams in the upper Coastal Plain of South Carolina and parts of North Carolina and Georgia. Aquifers that sustain the base flow of both large and small streams are stratified into shallow and deep flow systems. Base-flow during dry conditions on main stems of large streams was assumed to be the discharge from the deep groundwater flow system. Six streams were analyzed: the Savannah, South and North Fork Edisto, Lynches, Pee Dee, and the Luber Rivers. Stream reaches in the Upper Coastal Plain were studied because of the relatively large aquifer discharge in these areas in comparison to the lower Coastal Plain. Estimates of discharge from the deep groundwater flow system to the six large streams averaged 1.8 cu ft/sec/mi of stream and 0.11 cu ft/sec/sq mi of surface drainage area. The estimates were made by subtracting all tributary inflows from the discharge gain between two gaging stations on a large stream during an extreme low-flow period. These estimates pertain only to flow in the deep groundwater flow system. Shallow flow systems and total base flow are > flow in the deep system. (USGS)

Georgia, North Carolina, South Carolina↗
USGS1986

Retention time and flow patterns in Lake Moultrie, South Carolina

A liquid dye tracer was injected into the inflow to Lake Moultrie, South Carolina, during high-flow conditions and again during low-flow conditions. Tracer concentrations were monitored at a network of fixed sampling stations in the lake to determine dispersion and transport characteristics in and through the lake. Wind-generated currents were the major factor in dispersing the tracer and controlling the flow patterns, with the advective flow of water through the lake a secondary contributing factor. During the high-flow test, most of the tracer was flushed through the lake in 12 days, which did not allow time for the tracer to fully disperse throughout the lake. During the low-flow test, most of the tracer remained in the lake for more than a of a month. After 16 days it was dispersed throughout the lake. Concentrations of tracer decreased by a factor of about 500 as the dye clouds passed through the lake. (USGS)

South Carolina↗
USGS1984

Quality of water from bedrock aquifers in the South Carolina Piedmont

The geographic distributions of 12 common water-quality parameters of ground water from bedrock aquifers in the Piedmont physiographic province of South Carolina are presented in a series of maps. The maps are based on analyses by the South Carolina Department of Health and Environmental Control of water samples taken during the period 1972 to 1982 from 442 public and private wells developed in the Piedmont. In general, alkalinity, hardness, and concentrations of sodium, magnesium, and chloride were higher in the Carolina Slate Belt than they were in the other geologic belts of the Piedmont. (USGS)

South Carolina↗
USGS1983

Effect of the proposed Cooper River rediversion on sedimentation in Charleston Harbor, South Carolina

The rates of sedimentation and of resultant maintenance dredging in Charleston Harbor increased dramatically in the 1940s, following two major modifications to the harbor. One modification, the Santee-Cooper diversion project, caused a twentyfold increase in freshwater inflow to the harbor. The other modification was deepening of the navigation channels in the harbor from 30 to 35 feet below mean low water. After field and model studies indicated that the diversion was the major cause of the increase in the sedimentation rate, plans were made to redivert most of the Santee River water back to its former channel. This report documents a review of existing data and literature that was made to evaluate rediversion as a means of reducing the rate of maintenance dredging. The postrediversion decrease in the rate of maintenance dredging can be estimated only within broad limits because some important questions lack reliable answers. Analysis of available information indicates that rediversion will eventually reduce the rate of maintenance dredging by about 40 to 75 percent. The reduction in the rate of maintenance dredging may be delayed for a decade or more by the gradual removal of accumulated sediment and may be partially offset by the effects of future channel deepening.

South Carolina↗