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Megan (Shoda) Saksa


Ohio-Kentucky-Indiana Water Science Center

Office Phone: 317-600-2725
Fax: 317-290-3313
ORCID: 0000-0002-5343-9717

5957 Lakeside Blvd.
Indianapolis , IN 46278-1996

Supervisor: Jeffrey W Frey
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....
The U.S. Geological Survey (USGS) National Water Quality Network - Rivers and Streams (NWQN) is comprised of 110 surface-water monitoring sites designed to track ambient water-quality conditions across the nation. Although numerous constituents, including pesticides, have been collected at many of these sites since 1991, glyphosate and its metabolite aminomethylphosphonic acid (AMPA) were not routinely measured in NWQN water samples prior to 2014. Because of the widespread use of glyphosate for agricultural and nonagricultural applications, in 2014, these two compounds were added to the NWQN. This dataset includes concentrations of glyphosate and AMPA from water samples collected from 2015 through 2017 at 70 NWQN...
This data set contains U.S. Geological Survey (USGS) streamgage matching results in tabular format for water-quality sites retrieved from the Water Quality Portal for the Delaware River Basin. The table contains a list of water-quality sites joined to USGS streamgages where the water-quality site and USGS streamgage are located on the same stream, as represented by the National Hydrography Dataset Plus (NHDPlus) "LevelPathID" attribute. The file represents a one-to-many relationship: each water-quality site, as represented by the unique identifier, "MonitoringLocationIdentifier", is joined to anywhere from zero streamgages (not on same stream as any gage; the gage info columns are NA) to one or more streamgages...
Jointly managed by multiple states and the federal government, there are many ongoing efforts to characterize and understand water quality in the Delaware River Basin (DRB). Many State, Federal and non-profit organizations have collected surface-water-quality samples across the DRB for decades and many of these data are available through the National Water Quality Monitoring Council's Water Quality Portal (WQP). For this data release, WQP data in the DRB were harmonized, meaning that they were processed to create a clean and readily usable dataset. The harmonization process included the synthesis of parameter names and fractions, the condensation of remarks and other data qualifiers, the resolution of duplicate...
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...
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