Publications

Concern exists about the occurrence of agricultural chemicals, primarily nitrate and pesticides, in shallow ground water. In response to this concern, the focus of the Iowa ground-water-quality-monitoring program has shifted to emphasize nonpoint contaminants. The program, which began in 1982, is operated by the U.S. Geological Survey in cooperation with the University of Iowa Hygienic...

Tensas River National Wildlife Refuge, Madison Parish, Louisiana, consists of bottomland hardwood swamps interspersed with small lakes and bayous supporting a diverse assemblage of waterfowl, fish, and assorted species of game and nongame wildlife. Fish collected in the refuge in 1984–85 from areas receiving direct inflow from agricultural runoff contained from 5 to 10 μg/g total DDT...

The Grove Creek basin includes an area of about 42 square miles in Duplin County, southeastern North Carolina. This report evaluates sediment transport and sediment-accretion rates in the lowermost 9-mile reach of Grove Creek by using hydrologic, dendrologic, and radioisotopic data collected at seven sites along the study reach. Hydrologic data indicate two discharge frequencies. In the...

No abstract available.

Closed-system microcosms were used to study factors affecting the fate of selenium (Se) in aquatic systems. Distribution and bioaccumulation of Se varied among sediment types and Se species. A mixture of dissolved 75Se species (selenate, selenite and selenomethionine) was sorbed more rapidly to fine-textured, highly organic pond sediments than to sandy riverine sediments. Sulfate did not...

An important factor contributing to the deterioration of wetland forests in Louisiana is increasing water levels resulting from eustatic sea-level rise and subsidence. Analyses of long-term water level records from the Barataria and Verret watersheds in southeastern Louisiana indicate an apparent sea level rise of about 1-m per century, mainly the result of subsidence. Permanent study...

No abstract available.

The Edwards aquifer is the principle source of freshwater for municipal, domestic, and industrial users in the Georgetown area. Other sources of freshwater are the streams draining the San Gabriel River basin and Lake Georgetown. Lake Georgetown, located on the North Fork San Gabriel River west of Georgetown, is a freshwater supply for some municipalities in the area, water in the San...

The hydrogeologic framework of the North Carolina Coastal Plain aquifer system consists of ten aquifers separated by nine confining units. From top to bottom the aquifers are: the surficial aquifer, Yorktown aquifer, Pungo River aquifer, Castle Hayne aquifer, Beaufort aquifer, Peedee aquifer, Black Creek aquifer, upper Cape Fear aquifer, lower Cape Fear aquifer, and the Lower Cretaceous...

Continuous and periodic measurements in 54 key wells and water-level measurements emplaced in Coastal Plain aquifers across North Carolina in 193 supplemental wells are presented in this report. Hydrographs of selected wells show changes in ground-water storage in the State. The water table in the shallow aquifers was higher throughout most of the State in 1987 than in 1986, indicating...

A water treatment system and procedure are described that are designed for preparing large quantities of reconstituted water with specific chemical and physical characteristics for use in chronic toxicity studies with fish and invertebrates. Water treatment units produce high-purity water in large quantities for storage in high-density cross-linked polyethylene tanks, where it is...

Water resources data for the 1988 water year for Iowa consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; ground water levels and water quality of ground-water wells. This report contains records of water discharge for 117 stream-gaging stations; stage or contents for 7 lakes and reservoirs; water quality for 9...