Skip to main content
Advanced Search

Filters: Tags: quality control (X)

15 results (9ms)   

View Results as: JSON ATOM CSV
thumbnail
Field spikes were prepared at 207 stream and river sites as part of the U.S. Geological Survey (USGS) National Water Quality Assessment (NAWQA) project between December, 2012, and September, 2015. At the field site, a depth-and width-integrated environmental sample was collected, and one subsample of the environmental sample was spiked with a known amount of a spike mixture. Both the spiked subsample ("spike sample") and another subsample ("environmental sample") of the original water sample were analyzed for pesticides at the USGS National Water Quality Laboratory (NWQL) by direct injection liquid chromatography with tandem mass spectrometry (LC-MS/MS), and were used to calculate the spike recovery of each analyte....
thumbnail
This data set includes sample information and results for third-party performance assessment samples analyzed for hormones and pharmaceuticals during the same general time period as environmental samples collected by the National Water-Quality Assessment (NAWQA) Project for a study of groundwater resources used for drinking-water supply across the United States, 2013 through 2015. Hormone and pharmaceutical results are provided for spiked and unspiked samples submitted by the Quality Systems Branch (QSB) Organic Blind Sample Project (OBSP), providing information regarding analyte recovery and occurrence of false positive and false negative results. Included in this data release are the following data tables: Table...
thumbnail
This data release presents results of chemical analyses of groundwater sampled during summer and autumn of 2019 and spring of 2020 from 23 wells in the Great Miami buried-valley aquifer (GM-BVA) of southwestern Ohio. Groundwater and quality-control samples were analyzed to determine concentrations of selected per- and polyfluoroalkyl substances (PFAS). Groundwater and related quality-control samples were collected from 22 of 23 wells and analyzed for 24 different PFAS by two different laboratories that used slightly different proprietary isotope-dilution based adaptations of U.S. Environmental Protection Agency (USEPA) method 537.1, referred to as method 1 and method 2. Results from PFAS analysis of groundwater...
This data release contains two tables-one table of field spike recovery data and one table of lab reagent spike recovery data-for pesticides and pesticide degradates analyzed by the USGS National Water Quality Laboratory (NWQL) schedule 2437, and associated metadata. The table of field spike recovery data includes results from paired environmental and spike samples collected by the National Water Quality Program, National Water-Quality Assessment (NAWQA) Project in surface water. The table of lab reagent spike data contains quality-control sample information stored in the NWQL database. Both tables include fields for data-quality indicators that are described in the data processing steps of the metadata file....
thumbnail
This dataset contains data tables of laboratory quality-control data associated with environmental samples analyzed for microbiological constituents at the Ohio Water Microbiology Laboratory of the U.S. Geological Survey (USGS). The environmental samples were collected across the United States by USGS National Projects and projects in Water Science Centers. These quality-control data can be used to assess the quality of microbiological data for the associated environmental samples.
thumbnail
This data release includes tables and plots of results for pesticide compounds (pesticides and degradates) analyzed in groundwater samples collected by the USGS National Water-Quality Assessment Project during water years 2013-18 and in associated quality-control samples that are used to assess the quality of the reported pesticide results. All samples were analyzed by the USGS National Water Quality Laboratory (NWQL) using laboratory schedule 2437. The table of groundwater data includes pesticide results as reported by the laboratory, along with results that represent the application of censoring levels at the 90-percent upper confidence limit of the 95th percentile of laboratory blank concentrations determined...
thumbnail
Groundwater samples have been collected in California as part of statewide investigations of groundwater quality conducted by the U.S. Geological Survey for the Groundwater Ambient Monitoring and Assessment (GAMA) Priority Basin Project (PBP). Quality-control samples are routinely collected as part of the GAMA-PBP quality assurance plan. Olsen and others (2010) and Davis and others (2014) previously determined study reporting levels (SRLs) for trace-element results based primarily on field blanks collected in California from May 2004 through March 2013. SRLs are raised reporting levels used to reduce the likelihood of reporting false detections attributable to contamination bias. Davis and others (2014) reevaluated...
thumbnail
This data release includes tables and time-series plots of results for volatile organic compounds (VOCs) analyzed in samples of groundwater used for public supply that were collected by the USGS National Water-Quality Assessment (NAWQA) Project and the California State Water Resources Control Board’s Groundwater Ambient Monitoring and Assessment Program Priority Basin Project (GAMA-PBP) during 2013-19; results for associated quality-control samples also are included. All samples were analyzed by the USGS National Water Quality Laboratory (NWQL) using laboratory schedules 4436 and 4437. The table of groundwater data includes VOC results as reported by the laboratory, along with results that represent the application...
thumbnail
The U.S. Geological Survey collected samples from 50 public supply wells during two distinct sampling episodes (2004-2005 and 2014) on the North-Central California coast. During each sampling episode, the samples were analyzed for 160 water-quality constituents, including water-quality indicators, nutrients, major and minor ions, trace elements, volatile organic compounds, and pesticide compounds. The paired-sample results were submitted to an evaluation method to determine whether or not step trends had occurred in the concentrations of each constituent. Quality-control samples were collected at a subset of the wells. The datasets presented here consist of a list and description of the 160 constituents, an Excel...
thumbnail
The U.S. Geological Survey (USGS) National Water Quality Network - Rivers and Streams (NWQN) comprises 117 surface-water monitoring sites designed to track ambient water-quality conditions across the nation. This dataset includes field quality-control results (field blank and field replicate concentrations), along with the water-quality result of each associated surface-water sample, of water samples collected from October 2012 through September 2017 at NWQN sites. This dataset includes 2 tables and 6 files of plots of the data. Tables are in Comma Separated Value, CSV, format and plotfiles are in Portable Document Format, PDF, format. The plotfiles are intended to provide a succinct view of the data. Table1.NWQNFieldBlanksC3.csv...
Analytical recovery is the concentration of an analyte measured in a water-quality sample expressed as a percentage of the known concentration added to the sample (Mueller and others, 2015). Analytical recovery (hereafter referred to as “recovery”) can be used to understand method bias and variability and to assess the temporal changes in a method over time (Martin and others, 2009). This data set includes two tables: one table of field spike recovery data and one table of lab reagent spike recovery data. The table of field spike recovery data includes results from paired environmental and spike samples collected by the National Water Quality Program, National Water-Quality Assessment (NAWQA) Project in surface...
thumbnail
This data release includes all pesticide results from selected batches of water samples analyzed by the U.S Geological Survey National Water Quality Laboratory (NWQL). Samples were analyzed using gas chromatography/mass spectrometry (GCMS) or liquid chromatography/mass spectrometry (LCMS) methods. Eight datasets are included in this data release; 1) all environmental and field quality control (QC) results for 11 pesticide compounds from 70 selected batches of GCMS data from schedules 2001, 2003, 2032, and 2033 (Sandstrom and others, 2001; Zaugg and others, 1995) from May 2001-June 2015, 2) all environmental and field QC results for 10 pesticide compounds from 43 selected batches of LCMS data from schedule 2060 (Furlong...
thumbnail
From October 2017 through September 2022, the National Water Quality Network (NWQN) monitored 110 surface-water river and stream sites and more than 1,800 groundwater wells for a large number of water-quality analytes, for which associated quality-control data and corresponding statistical summaries are included in this data release. The quality-control data—for samples that were collected in the field (at all 110 surface-water sites, 350 groundwater wells, and 16 quality-control-only sites), prepared in the laboratory, or prepared by a third party—can be used to assess the quality of environmental data collected by the NWQN through the estimation of bias and variability in reported results. The general analyte...
thumbnail
This data record contains questions and responses to a USGS-wide survey conducted to identify issues and needs associated with quality assurance and quality control (QA/QC) of USGS timeseries data streams. This research was funded by the USGS Community for Data Integration as part of a project titled “From reactive- to condition-based maintenance: Artificial intelligence for anomaly predictions and operational decision-making”. The poll targeted monitoring network managers and technicians and asked questions about operational data streams and timeseries data collection in order to identity opportunities to streamline data access, expedite the response to data quality issues, improve QA/QC procedures, reduce operations...


    map background search result map search result map Data sets for: Variations on a method for evaluating decadal-scale changes in the groundwater quality of two GAMA coastal study units 2004-2014, California GAMA Priority Basin Project Pesticide datasets from the National Water Quality Laboratory, 2001-2016 Third-party performance assessment data encompassing the time period of analysis of groundwater samples collected for hormones and pharmaceuticals by the National Water-Quality Assessment Project in 2013-15 Blank results for trace-element data collected for the California Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project, October 2009–October 2018 Laboratory quality-control data associated with samples analyzed for microbiological constituents at the USGS Ohio Water Microbiology Laboratory Field, laboratory, and third-party data for assessment of the quality of pesticide results reported by the National Water Quality Laboratory for groundwater samples collected by the National Water-Quality Assessment Project, 2013-18 Field blank and field replicate datasets for inorganic and organic compounds collected for the National Water Quality Network, water years 2013-17 Per- and polyfluoroalkyl substance concentrations, age estimates, redox categories, and related data for groundwater from the Great Miami buried-valley aquifer, southwestern Ohio, 2019–20 Results from geochemical and mineralogical characterization of Boquillas Shale geochemical reference material ShBOQ-1 Data for volatile organic compounds in groundwater used for public supply across the United States, 2013-19, and data for associated quality-control samples Questions and responses to USGS-wide poll on quality assurance practices for timeseries data, 2021 Field, laboratory, and third-party quality-control data associated with sites and analytes monitored by the USGS National Water Quality Network, October 2017 through September 2022 Results from geochemical and mineralogical characterization of Boquillas Shale geochemical reference material ShBOQ-1 Per- and polyfluoroalkyl substance concentrations, age estimates, redox categories, and related data for groundwater from the Great Miami buried-valley aquifer, southwestern Ohio, 2019–20 Data sets for: Variations on a method for evaluating decadal-scale changes in the groundwater quality of two GAMA coastal study units 2004-2014, California GAMA Priority Basin Project Blank results for trace-element data collected for the California Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project, October 2009–October 2018 Pesticide datasets from the National Water Quality Laboratory, 2001-2016 Laboratory quality-control data associated with samples analyzed for microbiological constituents at the USGS Ohio Water Microbiology Laboratory Field, laboratory, and third-party data for assessment of the quality of pesticide results reported by the National Water Quality Laboratory for groundwater samples collected by the National Water-Quality Assessment Project, 2013-18 Data for volatile organic compounds in groundwater used for public supply across the United States, 2013-19, and data for associated quality-control samples Field blank and field replicate datasets for inorganic and organic compounds collected for the National Water Quality Network, water years 2013-17 Third-party performance assessment data encompassing the time period of analysis of groundwater samples collected for hormones and pharmaceuticals by the National Water-Quality Assessment Project in 2013-15 Questions and responses to USGS-wide poll on quality assurance practices for timeseries data, 2021 Field, laboratory, and third-party quality-control data associated with sites and analytes monitored by the USGS National Water Quality Network, October 2017 through September 2022