Skip to main content
U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Results

46733 results.

Alternate formats: RIS file of the first 3000 search results  |  Download all results as CSV | TSV | Excel  |  RSS feed based on this search  |  JSON version of this page of results

Page 1380, results 34476 - 34500

Show results on a map

Publication Extents

Not all publications have extents, not all extents are completely accurate
Hydrogeologic, water-quality, and land-use data for the reconnaissance of herbicides and nitrate in near-surface aquifers of the Midcontinental United States, 1991
D.W. Kolpin, M. R. Burkart, E.M. Thurman
1993, Open-File Report 93-114
Water samples were collected during the spring and summer of 1991 from 303 wells penetrating near-surface unconsolidated and bedrock aquifers of the midcontinental United States. Samples were analyzed for 11 herbicides, 2 dealkylated atrazine metabolites, and 4 nutrients. Specific conductance, pH, and dissolved-oxygen concentrations of the ground water were measured...
Report of the U.S. Geological Survey's evaluation program for standard reference samples distributed in April 1993; T-123 (trace constituents), T-125 (trace constituents), M-126 (major constituents, N-38 (nutrients), N-39 (nutrients), P-20 (low ionic strength, and Hg-16 (mercury)
H.K. Long, J.W. Farrar
1993, Open-File Report 93-436
This report presents the results of the U.S. Geological Survey's analytical evaluation program for seven standard reference samples--T-123 (trace constituents), T-125 (trace constituents), M-126 (major constituents), N-38 (nutrients), N-39 (Nutrients), P-20 (precipitation-low ionic strength), and Hg-16 (mercury)--that were distributed in April 1993 to 175 laboratories registered in the U.S. Geological...
Water-resources investigations in Wisconsin, 1993
D. E. Maertz
1993, Open-File Report 93-129
PROBLEM: Surface-water information is needed for surveillance, planning, design, hazard warning, operation, and management in water-related fields such as water supply, hydroelectric power, flood control, irrigation, bridge and culvert design, wildlife management, pollution abatement, flood-plain management, and water-resources development. An appropriate data base is necessary to provide this information. OBJECTIVE: The...
Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory-Determination of chromium in water by graphite furnace atomic absorption spectrophotometry
B.J. McLain
1993, Open-File Report 93-449
Graphite furnace atomic absorption spectrophotometry is a sensitive, precise, and accurate method for the determination of chromium in natural water samples. The detection limit for this analytical method is 0.4 microg/L with a working linear limit of 25.0 microg/L. The precision at the detection limit ranges from 20 to 57...
Hydrogeology and water quality of the Galena-Platteville aquifer at the Parson's Casket Hardware Superfund site, Belvidere, Illinois, 1991-92
P. C. Mills
1993, Open-File Report 93-404
The purpose of this letter is to describe the results of the final phase (phase 3) of the U.S. Geological Survey's (USGS) ground-water investigation at the Parson's Casket Hardware site, Belvidere, Ill. (figs. 1 and 2), for the U.S. Environmental Protection Agency (USEPA). Included in this letter are brief descriptions...
Vertical distribution of hydraulic characteristics and water quality in three boreholes in the Galena-Platteville Aquifer at the Parson's Casket Hardware Superfund site, Belvidere, Illinois, 1990
P. C. Mills
1993, Open-File Report 93-402
The U.S. Geological Survey investigated contaminant migration in the Galena-Platteville aquifer at the Parson's Casket Hardware site in Belvidere, Ill. This report presents the results of the first phase of the investigation, from August through December 1990. A packer assembly was used to isolate various depth intervals in three 150-foot-deep boreholes...
Well-construction, water-level, and ground-water-quality data for Prince William County, Virginia, 1992
D.L. Nelms, A. R. Brockman
1993, Open-File Report 93-443
Well-construction, water-level, and ground-water- quality data were collected by the U.S. Geological Survey during 1989-92 in Prince William County, Virginia. The data are presented on a map, in tables, and in hydrographs to record ambient ground-water quality. Well construction data include descriptions of 182 well sites. Water-level data include measurements...
Ground-water-quality assessment of the Central Oklahoma Aquifer, Oklahoma: Geochemical and geohydrologic investigations
David L. Parkhurst, Scott C. Christenson, George N. Breit
1993, Open-File Report 92-642
The National Water-Quality Assessment pilot project for the Central Oklahoma aquifer examined the chemical and isotopic composition of ground water, the abundances and textures of minerals in core samples, and water levels and hydraulic properties in the flow system to identify geochemical reactions occurring in the aquifer and rates and...
Observations and modeling of seismic background noise
Jon R. Peterson
1993, Open-File Report 93-322
The preparation of this report had two purposes. One was to present a catalog of seismic background noise spectra obtained from a worldwide network of seismograph stations. The other purpose was to refine and document models of seismic background noise that have been in use for several years. The second...