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Christopher Churchill

Ecological Sciences Branch Chief

Upper Midwest Environmental Sciences Center

Office Phone: 608-781-6338
Fax: 608-783-0110
ORCID: 0000-0002-3227-3551

UMESC - Laboratory/Office - #1
2630 Fanta Reed Road
La Crosse , WI 54603

Supervisor: Mark P Gaikowski
In cooperation with Dallas Water Utilities (DWU), the U.S. Geological Survey (USGS) measures nutrient and major-ion concentrations in selected reservoirs in north Texas. This data release documents water-quality data obtained from Ray Hubbard Lake, Grapevine Lake, Ray Roberts Lake, and Lake Lewisville during water years 2016-20. In addition to nutrient and major-ion concentrations, water-quality field properties and other selected constituents measured in the water-quality samples collected from these reservoirs are documented. The study began in water year 2016 (WY16) with monthly sampling of Ray Hubbard Lake. A water year is defined as the 12-month period from October 1 through September 30 and is designated...
Dispersal, establishment, and spread of aquatic invasive species such as the zebra mussel (Dreissena polymorpha) can be influenced by riverine velocities and volumetric flows in invaded lake-stream ecosystems. Zebra mussels, which have a planktonic larval form (veliger), disperse rapidly downstream from a source population. Concentrations, dispersal, and body conditions of zebra mussel veligers were studied under different volumetric flow, or discharge, conditions in a coupled lake-stream ecosystem in northern Texas, USA. Veliger densities in lotic environments were strongly related to population dynamics in upstream lentic source populations. A strong exponential decrease in veliger density was observed through...
This U.S. Geological Survey (USGS) Data Release provides phytoplankton data collected from 18 Texas reservoirs during August through October, 2016. All data are reported as raw calculated values and are not rounded to USGS significant figures. This data release was produced in compliance with the open data requirements as a way to make scientific products associated with USGS research efforts and publications available to the public. The dataset includes all routine and quality assurance/quality control samples collected at each of the sites. Phytoplankton were identified to the lowest possible taxonomic level and abundance (density reported as both natural units and cells) and biovolume are reported.
Categories: Data, Data Release - Revised; Tags: Algae, Benbrook Lake, Site CC near Fort Worth, TX, Braunig Lake, Site CC near Elmendorf, TX, Caruth Lake, Site CC near Rockwall, TX, Class, All tags...
This data release documents water-quality data obtained as part of an assessment of compounds of emerging concern (CECs) measured in samples collected at potable water and wastewater treatment plants in Dallas and downstream from Dallas in the Trinity River from August 2009 to December 2013 by the U.S. Geological Survey in cooperation with the City of Dallas, Dallas Water Utilities. Targeted CECs (120 total) included human-health pharmaceuticals (prescription and non-prescription), antibiotics, steroidal hormones, stanols, sterols, detergents, personal-use products (flavors and fragrances), pesticides and repellents, industrial wastewater compounds, disinfection compounds, PAHs, flame retardants, and plasticizers....
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