Publications

Water level measurements were made in 95 wells open to the Black Creek aquifer at the end of 1986 to determine the configuration of its potentiometric surface over an area of about 4,900 sq mi in the central Coastal Plain of North Carolina. The altitude of the potentiometric surface of the Black Creek ranges between 80 and 100 ft above sea level along the western limit of the aquifer. From there t

Precipitation, streamflow, and base-flow data were analyzed for December 1974 through March 1977 as a part of the Edwards-Trinity Regional Aquifer-System Analysis in west-central Texas. The period of record analyzed corresponds to the calibrating period of a digital groundwater-flow model of the aquifer system currently (1988) being developed. Precipitation at individual stations ranged from 6 to

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 Gabriel Rive

This report shows the altitudes of water levels in the Chicot and Evangeline aquifers in the Houston metropolitan area, Texas. Of the 425 wells measured, 307 were used to construct the maps of potentiometric surface. The Chicot and Evangeline aquifers are composed of several sand layers, each with a separate potentiometric surface. These maps, however, show a single potentiometric surface which re

This report presents data on water-level changes in the Chinot and Evangeline aquifers during 1977-89 and 1988-89 and data on measured compaction during 1973-89. Measurements of water level in 307 wells were used to construct the maps showing water-level changes. Compaction data were obtained from 12 wells equipped with compaction monitors at 11 sites.

Physical and chemical water-quality data and nitrogen and phosphorus yields for 29 sites sampled in two synoptic surveys of streams within the Lewisville Lake watershed are presented in this report. The two synoptic surveys were conducted in March 1984 and March 1985, as a reconnaissance and assessment of water quality and nitrogen and phosphorus yields throughout the watershed. This work was coop

The chemical quality of the ground water in the Floridan aquifer system is determined primarily by mineral-water interaction. However, some changes in water quality have been imposed by development, particularly near coastal pumping centers. A total of 601 chemical analyses, all from different wells, most completed in the upper part of the aquifer system, were used to describe the variations in wa

Tiered testing for the effects of chemicals on aquatic ecosystems has begun to include tests at the ecosystem level as a component in pesticide regristration. Because such tests are expensive, regulators and industry need to know what additional information they can gain from such tests relative to the costs of the simpler single-species toxicity bioassays. Requirements for ecosystem-level testing

No abstract available.

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 (primarily DD

No abstract available.

As of January 1, 1989, the surface-water data-collection network in Texas included 373 continuous-streamflow, 75 continuous or daily reservoir-content, 37 gage-height, 15 crest-stage partial-record, 200 data collection platform, 7 periodic discharge through range, 27 flood-hydrograph partial-record, 27 low-flow partial-record, 43 daily chemical-quality, 17 continuous-recording water quality, 87 pe