Thomas Chapin
Science and Products
Lake Koocanusa Water Quality
Lake Koocanusa is a transboundary reservoir located in southeastern British Columbia and northwestern Montana. The reservoir was officially impounded in 1972 after construction of Libby Dam, which began in 1966. The dam was constructed as part of a treaty between the United States and Canada to cooperatively develop the water resources of the Columbia River drainage basin. The reservoir has a...
Assessing uranium and select trace elements associated with breccia pipe uranium deposits in the Colorado River and main tributaries in Grand Canyon, USA
Assessing chemical loading from streams in remote, difficult-to-access watersheds is challenging. The Grand Canyon area in northern Arizona, an international tourist destination and sacred place for many Native Americans, is characterized by broad plateaus divided by canyons as much as two-thousand meters deep and hosts some of the highest-grade...
Tillman, Fred; Anderson, Jessica; Unema, Joel; Chapin, Thomas New perspectives on a 140-year legacy of mining and abandoned mine cleanup in the San Juan Mountains, Colorado
The Gold King mine water release that occurred on 5 August 2015 near the historical mining community of Silverton, Colorado, highlights the environmental legacy that abandoned mines have on the environment. During reclamation efforts, a breach of collapsed workings at the Gold King mine sent 3 million gallons of acidic and metal-rich mine water...
Yager, Douglas B.; Fey, David L.; Chapin, Thomas; Johnson, Raymond H. High-frequency, long-duration water sampling in acid mine drainage studies: a short review of current methods and recent advances in automated water samplers
Hand-collected grab samples are the most common water sampling method but using grab sampling to monitor temporally variable aquatic processes such as diel metal cycling or episodic events is rarely feasible or cost-effective. Currently available automated samplers are a proven, widely used technology and typically collect up to 24 samples during...
Chapin, Thomas Robust, low-cost data loggers for stream temperature, flow intermittency, and relative conductivity monitoring
Water temperature and streamflow intermittency are critical parameters influencing aquatic ecosystem health. Low-cost temperature loggers have made continuous water temperature monitoring relatively simple but determining streamflow timing and intermittency using temperature data alone requires significant and subjective data interpretation....
Chapin, Thomas; Todd, Andrew S.; Zeigler, Matthew P. High nutrient pulses, tidal mixing and biological response in a small California estuary: Variability in nutrient concentrations from decadal to hourly time scales
Elkhorn Slough is a small estuary in Central California, where nutrient inputs are dominated by runoff from agricultural row crops, a golf course, and residential development. We examined the variability in nutrient concentrations from decadal to hourly time scales in Elkhorn Slough to compare forcing by physical and biological factors. Hourly...
Caffrey, J.M.; Chapin, T.P.; Jannasch, H.W.; Haskins, J.C. Development of a solenoid pumped in situ zinc analyzer for environmental monitoring
A battery powered submersible chemical analyzer, the Zn-DigiScan (Zn Digital Submersible Chemical Analyzer), has been developed for near real-time, in situ monitoring of zinc in aquatic systems. Microprocessor controlled solenoid pumps propel sample and carrier through an anion exchange column to separate zinc from...
Chapin, T.P.; Wanty, R. B. Nitrate sources and sinks in Elkhorn Slough, California: Results from long-term continuous in situ nitrate analyzers
Nitrate and water quality parameters (temperature, salinity, dissolved oxygen, turbidity, and depth) were measured continuously with in situ NO3 analyzers and water quality sondes at two sites in Elkhorn Slough in Central California. The Main Channel site near the mouth of Elkhorn Slough was sampled from February to September 2001. Azevedo...
Chapin, T.P.; Caffrey, J.M.; Jannasch, H.W.; Coletti, L.J.; Haskins, J.C.; Johnson, K.S. In situ osmotic analyzer for the year-long continuous determination of Fe in hydrothermal systems
A submersible osmotically pumped analyzer (Fe-OsmoAnalyzer) has been adapted for the long-term continuous high resolution monitoring of iron(II) and (III) in deep-sea hydrothermal vents. Ferrozine is used as the colorimetric reagent. The detection limit for our analyzer is 0.1??M for a 0.7cm pathlength with a linear response up to 50??M. The Fe-...
Chapin, T.P.; Jannasch, H.W.; Johnson, K.S.