Emeritus Scientist
Email:
rlsmith@usgs.gov
Office Phone:
303-541-3032
ORCID:
0000-0002-3829-0125
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This data release presents results from a laboratory study designed to measure the effect of temperature on denitrification rates in sediments collected from 5- to 30-cm depth below the lake bottom, at a location where groundwater discharges to the lake. Sediment cores were collected June 25, 2014 from the West site (Fishermans Cove) in Ashumet Pond, Cape Cod, MA then shipped to Boulder, CO for laboratory experiments. Groundwater used for these experiments was collected from a well just upgradient of the sediment collection site. Denitrification rates were determined on sediment plus groundwater slurries maintained under anaerobic conditions and employing the acetylene block method. Nitrous oxide concentrations...
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The U.S. Geological Survey Toxic Substances Hydrology Program at Cape Cod has been investigating the fate and transport of a treated-wastewater, groundwater contaminant plume. A portion of the contaminated groundwater discharges into Ashumet Pond, a kettle hole, freshwater lake. A study was conducted from June 2013 to June 2015 to document transport, transformation, and discharge of dissolved inorganic nitrogen species (DIN; nitrate, nitrite, and nitrous oxide) from the contaminant plume to the lake, across the groundwater-surface water interface. As part of that study, in October 2014, two natural gradient tracer tests were conducted within the lake bed sediments using nitrite as a reactive tracer and bromide as...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Ashumet Pond,
Denitrification,
Environmental Health,
Geochemistry,
Groundwater-surface water interaction, All tags...
Hydrogeology,
Lakes,
Nitrate,
USGS Science Data Catalog (SDC),
Water Quality, Fewer tags
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To study the mechanisms, pathways, and rates of transformation of carbon and nitrogen compounds (natural and contaminant) mediated by microorganisms in aquatic habitats and identify factors controlling these transformations and to examine the effect that these transformations have upon other biogeochemical processes.
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High latitude, boreal watersheds are nitrogen-limited ecosystems that export large amounts of organic carbon. Key controls on carbon cycling in these environments are the biogeochemical processes affecting the nitrogen cycle. This data release presents results of a 3-year field study from 2008-2011 to document the relation between seasonal and transport-associated changes in carbon and nitrogen pools within Nome Creek, an upland headwater tributary of the Yukon River, Alaska, and two first order tributaries to Nome Creek, West Twin Creek and East Twin Creek. Stream-water geochemistry was characterized using: a) biweekly sampling at fixed sampling stations to assess changes through the course of a summer season;...
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The data presented here was collected at Prado Wetlands in Riverside County, CA, USA. Physical water column parameters were collected using a multprobe sonde and includes date and time of sample collection, location (inlet, outlet), temperature (degrees Celsius), pH, specific conductivity (mircoSiemens per centimeter), and dissolved oxygen (milligrams per liter). An ISCO autosampler was utilized to remotely collect diel water samples at the inlet and outlet of the wetland. These samples were analyzed for dissolved metals (aluminum, arsenic, boron, barium, beryllium, bismuth, bromine, calcium, cadmium, cerium, cobalt, chromium, copper, dysprosium, erbium, europium, iron, gallium, gadolinium, holmium, potassium, lanthanum,...
Categories: Data;
Tags: Prado Wetlands,
Riverside County,
Southern California,
USGS Science Data Catalog (SDC),
Water Quality, All tags...
diel cycling,
dissolved metals,
engineered wetlands,
environment,
nitrogen,
porewater,
water quality, Fewer tags
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