Publications

The U.S. Geological Survey, in cooperation with the City of Fort Madison, conducted a study of the potential sources and possible processes that might produce ammonia in ground water from the Mississippi River alluvium near Fort Madison, Iowa. High ammonia concentrations of 3.0 to 6.4 milligrams per liter were detected in water produced from municipal well Fort Madison #4 from 1992 through 1996. T

Nitrate (NO3) and other nutrients discharged by the Mississippi River combined with seasonal stratification of the water column are known to cause a zone of depleted dissolved oxygen (hypoxic zone) in the Gulf of Mexico each summer. About 120 water and suspended sediment samples collected in 1997 and 1998 from 24 locations in the Mississippi River Basin were analyzed for the isotope ratios δ15N an

To protect and manage rivers and streams (hereafter, collectively referred to as streams) in the United States, the U.S. Environmental Protection Agency (USEPA) is establishing regionally based nutrient criteria that reflect the natural variability in water quality. As a basic approach to establish these criteria, the USEPA has divided the country into nutrient ecoregions (delineated on the basis

Improving water quality of Cheney Reservoir in south-central Kansas is an important objective of State and local water managers. The reservoir serves as a water supply for about 350,00 people in the Wichita area and an important recreational resource for the area. In 1992, a task force was formed to study and prepare a plan to identify and mitigate potential sources of stream contamination in the

Since the construction of Dillon Reservoir, in Summit County, Colorado, in 1963, its drainage area has been the site of rapid urban development and the continued influence of historical mining. In an effort to assess changes in water quality within the drainage area, sediment cores were collected from Dillon Reservoir in 1997. The sediment cores were analyzed for pesticides, polychlorinated biphen

A statewide study was conducted to develop two methods for estimating the magnitude and frequency of floods in rural ungaged basins in North Carolina. Flood-frequency estimates for gaged sites in North Carolina were computed by fitting the annual peak flows for each site to a log-Pearson Type III distribution. As part of the computation of flood-frequency estimates for gaged sites, new values for

A benchmark irrigation monitoring network of farms located in a 32-county area in southwestern Georgia was established in 1995 to improve estimates of irrigation water use. A stratified random sample of 500 permitted irrigators was selected from a data base--maintained by the Georgia Department of Natural Resources, Georgia Environmental Protection Division, Water Resources Management Branch--to o

The North Fork Pheasant Branch Basin in Dane County, Wisconsin is expected to undergo development. There are concerns that development will adversely affect water resources with increased flood peaks, increased runoff volumes, and increased pollutant loads. To provide a scientific basis for evaluating the hydrologic system response to development the Precipitation Runoff Modeling System (PRMS) was

The vegetated stormwater-detention basin at a small residential development in Monroe County, N.Y. has been shown to be effective in reducing loads of certain chemical constituents to receiving waters. Loads of suspended solids, nitrogen, and phosphorus have been reduced by an average of 14 to 62 percent. The basin has little effect on the temperature of runoff between the inflow and the outflow;

During 1996?98, rainfall and runoff were monitored on a 49,680-acre agricultural watershed in Kleberg and Nueces Counties in South Texas. Nineteen rainfall samples were analyzed for selected nutrients, and runoff samples from 29 storms were analyzed for major ions, nutrients, and pesticides. Loads of nutrients in rainfall and loads of nutrients and pesticides in runoff were computed. For a

IntroductionSaltwater contamination is restricting the development of ground-water supply in coastal Georgia and adjacent parts of South Carolina and Florida. The principal source of water in the coastal area is the Upper Floridan aquifer—an extremely permeable and high-yielding aquifer—which was first developed in the late 1800s. Pumping from the aquifer has resulted in substantial ground-water-l

Over 250 benthic invertebrate taxa were identified from snags and woody debris in streams and rivers of the Wapsipinicon, Cedar, Iowa, and Skunk River Basins in the Eastern Iowa Basins (EIWA) study unit of the U.S. Geological Survey National Water-Quality Assessment Program. The composition, distribution, and abundance of 74 predominant taxa were related to environmental conditions in the study un