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Kurt D Carpenter
Kurt joined the USGS Oregon Water Science Center in 1992 to work as a biologist for the National Water Quality Assessment (NAWQA) Program. For his graduate work in limnology at Portland State University, Kurt investigated phytoplankton-nutrient interactions in lakes within the Mount St. Helens blast zone to track their recovery since the 1980 eruption. Since then, Kurt's research focus has been on the effects of nutrient enrichment (eutrophication) and impacts on drinking water quality and aquatic food webs in the Clackamas, Tualatin, Molalla, North Santiam, North Umpqua, and Yakima Rivers. In 2008, Kurt completed a drinking water study on the Clackamas River with a particular emphasis on pesticides. More recently, Kurt examined sources of organic carbon that contribute to disinfection by-products in treated drinking water from the Clackamas River, and investigated the dynamics of algal populations and bloom crashes in the Tualatin River. Kurt is currently conducting a study of current-use pesticides in urban streams and stormwater outfalls in Clackamas County.
Science and Products
Reconnaissance of mixed organic and inorganic chemicals in private and public supply tapwaters at selected residential and workplace sites in the United States
Safe drinking water at the point-of-use (tapwater, TW) is a United States public health priority. Multiple lines of evidence were used to evaluate potential human health concerns of 482 organics and 19 inorganics in TW from 13 (7 public supply, 6 private well self-supply) home and 12 (public supply) workplace locations in 11 states. Only uranium (...Bradley, Paul M.; Kolpin, Dana W.; Romanok, Kristin M.; Smalling, Kelly L.; Focazio, Michael J.; Brown, Juliane B.; Cardon, Mary C.; Carpenter, Kurt; Corsi, Steven R.; DeCicco, Laura A.; Dietze, Julie E.; Evans, Nicola; Furlong, Edward T.; Givens, Carrie E.; Gray, James; Griffin, Dale W.; Higgins, Christopher P.; Hladik, Michelle L.; Iwanowicz, Luke R. ; Journey, Celeste A.; Kuivila, Kathryn ; Masoner, Jason R.; McDonough, Carrie A.; Meyer, Michael T.; Orlando, James L.; Strynar, Mark J.; Weis, Christopher P.; Wilson, Vickie S.
A river-scale Lagrangian experiment examining controls on phytoplankton dynamics in the presence and absence of treated wastewater effluent high in ammonium
Phytoplankton are critical component of the food web in most large rivers and estuaries, and thus identifying dominant controls on phytoplankton abundance and species composition is important to scientists, managers, and policymakers. Recent studies from a variety of systems indicate that ammonium ( NH+4) in treated wastewater effluent decreases...Kraus, Tamara E. C.; Carpenter, Kurt; Bergamaschi, Brian; Parker, Alexander; Stumpner, Elizabeth; Downing, Bryan D.; Travis, Nicole; Wilkerson, Frances; Kendall, Carol; Mussen, Timothy
Storm-event-transport of urban-use pesticides to streams likely impairs invertebrate assemblages
Insecticide use in urban areas results in the detection of these compounds in streams following stormwater runoff at concentrations likely to cause toxicity for stream invertebrates. In this 2013 study, stormwater runoff and streambed sediments were analyzed for 91 pesticides dissolved in water and 118 pesticides on sediment. Detections included...Carpenter, Kurt; Kuivila, Kathryn ; Hladik, Michelle; Haluska, Tana L.; Michael B. Cole
Water quality and algal conditions in the North Umpqua River, Oregon, 1995-2007, and their response to Diamond Lake restoration
The Wild and Scenic North Umpqua River is one of the highest-quality waters in the State of Oregon, supporting runs of wild salmon, steelhead, and trout. For many years, blooms of potentially toxic blue-green algae in Diamond and Lemolo Lakes have threatened water quality, fisheries, and public health. The blooms consist primarily of Anabaena, a...Carpenter, Kurt D.; Anderson, Chauncey W.; Jones, Mikeal E.
Plankton communities and summertime declines in algal abundance associated with low dissolved oxygen in the Tualatin River, Oregon
Phytoplankton populations in the Tualatin River in northwestern Oregon are an important component of the dissolved oxygen (DO) budget of the river and are critical for maintaining DO levels in summer. During the low-flow summer period, sufficient nutrients and a long residence time typically combine with ample sunshine and warm water to fuel...Carpenter, Kurt D.; Rounds, Stewart A.
Sources and characteristics of organic matter in the Clackamas River, Oregon, related to the formation of disinfection by-products in treated drinking water
This study characterized the amount and quality of organic matter in the Clackamas River, Oregon, to gain an understanding of sources that contribute to the formation of chlorinated and brominated disinfection by-products (DBPs), focusing on regulated DBPs in treated drinking water from two direct-filtration treatment plants that together serve...Carpenter, Kurt D.; Kraus, Tamara E.C.; Goldman, Jami H.; Saraceno, John Franco; Downing, Bryan D.; Bergamaschi, Brian A.; McGhee, Gordon; Triplett, Tracy
Geomorphic setting, aquatic habitat, and water-quality conditions of the Molalla River, Oregon, 2009-10
This report presents results from a 2009-10 assessment of the lower half of the Molalla River. The report describes the geomorphic setting and processes governing the physical layout of the river channel and evaluates changes in river geometry over the past several decades using analyses of aerial imagery and other quantitative techniques.Carpenter, Kurt D.; Czuba, Christiana R.; Magiri, Christopher S.; Marineau, Mathieu D.; Sobieszczyk, Steve; Czuba, Jonathan A.; Keith, Mackenzie K.
The Effects of Urbanization and Other Environmental Gradients on Algal Assemblages in Nine Metropolitan Areas across the United States
The U.S. Geological Survey conducted studies from 2000 to 2004 to determine the effects of urbanization on stream ecosystems in nine major metropolitan study areas across the United States. Biological, chemical, and physical components of streams were assessed at 28 to 30 sites in each study area. Benthic algae were sampled to compare the degree...Coles, James F.; Bell, Amanda H.; Scudder, Barbara C.; Carpenter, Kurt D.
Assessment of Eutrophication in the Lower Yakima River Basin, Washington, 2004-07
In response to concerns that excessive plant growth in the lower Yakima River in south-central Washington was degrading water quality and affecting recreational use, the U.S. Geological Survey and the South Yakima Conservation District conducted an assessment of eutrophication in the lower 116 miles of the river during the 2004-07 irrigation...Wise, Daniel R.; Zuroske, Marie L.; Carpenter, Kurt D.; Kiesling, Richard L.
Hydrologic and Water-Quality Conditions During Restoration of the Wood River Wetland, Upper Klamath River Basin, Oregon, 2003-05
Restoring previously drained wetlands is a strategy currently being used to improve water quality and decrease nutrient loading into Upper Klamath Lake, Oregon. In this 2003-05 study, ground- and surface-water quality and hydrologic conditions were characterized in the Wood River Wetland. Nitrogen and phosphorus levels, primarily as dissolved...Carpenter, Kurt D.; Snyder, Daniel T.; Duff, John H.; Triska, Frank J.; Lee, Karl K.; Avanzino, Ronald J.; Sobieszczyk, Steven
Organic Compounds in Clackamas River Water Used for Public Supply near Portland, Oregon, 2003-05
Organic compounds studied in this U.S. Geological Survey (USGS) assessment generally are man-made, including pesticides, gasoline hydrocarbons, solvents, personal care and domestic-use products, disinfection by-products, and manufacturing additives. In all, 56 compounds were detected in samples collected approximately monthly during 2003-05 at the...Carpenter, Kurt D.; McGhee, Gordon
Pesticide Occurrence and Distribution in the Lower Clackamas River Basin, Oregon, 2000-2005
Pesticide occurrence and distribution in the lower Clackamas River basin was evaluated in 2000?2005, when 119 water samples were analyzed for a suite of 86?198 dissolved pesticides. Sampling included the lower-basin tributaries and the Clackamas River mainstem, along with paired samples of pre- and post-treatment drinking water (source and...Carpenter, Kurt D.; Sobieszczyk, Steven; Arnsberg, Andrew J.; Rinella, Frank A.