Data

In this dataset we present two maps that estimate the location and population served by domestic wells in the contiguous United States. The first methodology, called the Block Group Method or BGM, builds upon the original block-group data from the 1990 census (the last time the U.S. Census queried the population regarding their source of water) by incorporating higher resolution census block data.

Replicate water-quality samples are collected and prepared in the field and analyzed in the laboratory in identical ways so that they are considered to be the same in composition and analysis (Mueller and others, 2015). This data set includes one table of duplicate National Water-Quality Assessment Project (NAWQA) surface water and groundwater samples collected between October 1, 2012 and Septembe

Groundwater samples were collected from domestic and public-supply wells in the Eagle Ford study area in 201516, in the Fayetteville study area in 2015, and in the Haynesville study area in 201415. One sample of produced water was collected from a gas well in the Haynesville  Shale in Rusk County, Texas in 2010, and 5 samples of produced water were collected from oil and condensate wells in the Ea

Dissolved pesticides were measured in weekly water samples from 100 freshwater streams across eleven states in the Midwestern U.S. during May-August, 2013. A total of 182 pesticide compounds (94 pesticides and 88 degradates) were detected, with a median of 25 compounds detected per sample and 54 detected per site. Potential aquatic toxicity was evaluated using the Pesticide Toxicity Index and by c

Defining the oxic-suboxic interface is often critical for determining pathways for nitrate transport in groundwater and to streams at the local scale. Defining this interface on a regional scale is complicated by the spatial variability of reaction rates. The probability of oxic groundwater in the Chesapeake Bay watershed was predicted by relating dissolved O2 concentrations in groundwater samples

This Data Release makes available measurements of phytoplankton species composition, abundance and cell size made on samples collected in San Francisco Bay (CA) from April 1992 through March 2014. Phytoplankton samples were collected at 31 stations along a 145-km transect where the variability of salinity, temperature, turbidity and nutrient concentrations reflected a broad range of environmental

The ascii grids associated with this data release are model inputs representing the Central Valley aquifer, California, and predicted nitrate concentrations (as NO3-N, mg/L) at two depth zones associated with private and public drinking water supply wells, respectively, . The model input and prediction grids are bound by the alluvial bed boundary that defines the Central Valley. The prediction gri

The National Water-Quality Assessment (NAWQA) Program and National Stream Quality Accounting Network (NASQAN) are U.S. Geological Survey (USGS) monitoring programs that measure pesticide concentrations in the Nations streams and rivers, herein collectively referred to as streams. The NAWQA Program began monitoring pesticides in 1992 and the NASQAN Program began monitoring pesticides in 1995. The p

The U.S. Geological Survey (USGS) National Water Quality Program (NWQP) provides an understanding of water-quality conditions; whether conditions are getting better or worse over time; and how natural features and human activities affect those conditions. The Surface Water Trends (SWT) project of NWQP evaluates the directions, periods, and statistical significance of trends in water quality in str

This data set presents the results of conducting Mercury Intrusion Porosimetry on core samples of the mudstone underlying the Naval Air Warfare Center, West Trenton, NJ. The core samples were selected from the continuous core collected from boreholes 83BR-89BR.

This data set presents the lithologic interpretation of rock cores from boreholes 83BR-89BR collected from the mudstone aquifer underlying the Naval Air Warfare Center (NAWC), West Trenton, NJ. Continuous core from these boreholes was collected and visually interpreted to identify characteristics of the depositional environment of the mudstone. Three types of mudstone were identified: a black-fis

In a crude-oil-contaminated sandy aquifer at the Bemidji site in northern Minnesota, biodegradation of petroleum hydrocarbons has resulted in release of naturally occurring As to groundwater under Fe-reducing conditions. This data set was collected for a study that used chemical extractions of aquifer sediments collected in 1993 and 2011-2014 to evaluate the relationship between Fe and As in diffe