Environmental Chemistry and Water Quality Studies
CEO Doug Craft has extensive experience performing multidisciplinary enviromental and water quality studies. These investigations have ranged from one time collection of samples to multi-year investigations involving assessment of comtaminant sources and transport at the watershed and basin scale. We can help you plan your study to optimize budgets, or we can help you analyze and interpret data already collected by your staff or others. We know how to interpret water quality data with respect to regulatory concentrations for fishery health, aquatic life, drinking water, human fish consumption, or other beneficial uses. And we have analyzed and interpreted large and complex data sets including chemical, biological, geological, and hydrological processes and interactions that combine to produce water quality. The following are examples of our experience performing environmental studies:
Reservoir and Lake Chemistry |
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To the left is Ridgway Reservoir, Colorado, first filled in 1983. The watershed for this oligotrophic lake includes heavily mined uplands with significant trace metal sources. We performed sediment-water microcosm simulation of the reservoir bottom before first filling. These predictive data were then compared with a 15-year record of chemical data from water quality monitoring of the 2 rivers that fill the reservoir and chemistry measured in the reservoir and sediments.
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Mercury and Methylmercury in Water and Biota |
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To the right is Leslie Gulch on Lake Owyhee, Oregon. This eutrophic reservoir receives mercury pollution from a watershed containing historical mine wastes and naturally occuring mercury in the volcanic geology. This study involved a 4-year sampling program on the reservoir and used ultra clean sampling protocols to collect water and sediment samples for very low detection limit mercury analyses. |
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To the left is the Carson River at Fort Churchill in Nevada. This valley and the Carson Sink received significant mercury pollution from historical mining of the Comstock Lode in Virginia City and Dayton. It is one of the the most heaviliy mercury-contaminated sites in the world. This study performed a detailed literature survey and summarized mercury data from water, streams, and biota in a comprehensive survey report. |
Mine Tailings and Snowmelt Runoff |
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Mine wastes in tailings piles are a common sight in the western US, a leftover from late 19th century gold and silver mining. Toxic trace elements are often flushed from tailings during early spring snowmelt. A study was performed on snowmelt mobilization of trace elements from tailing piles above California Gulch near Leadville, Colorado as part of a remediation investigation for the EPA's California Gulch Superfund Site. |
 Above are tailings piles near Virginia City, Nevada, the site of the Comstock Lode silver strike in the late 1800's. To the left is the Uncompahgre River near the confluence of Red Mountain Creek. The orange-brown cast to the water is from oxidized iron from acid mine drainage. |
Water Quality at the Tracy Fish Collection Facility. Tracy, Ca |
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 Above is the automated YSI multiprobe sonde that measured water quality variables in the channel at Tracy. This probe was maintained and calibrated on a bi-weekly schedule throughout the 7 year study. To the right a graph from a recent Tracy Report showing 7 years of conductivity data (EC) along with streamflow runoff, precipitation, and agricultural export pumping used to help interpret and assess the sonde data. |
The Tracy Fish Collection Facility is a fish salvage operation at the intake of the Delta Mendota Canal, an irrigation canal in the Central Valley of California. Doug planned and conducted a water quality monitoring program from 1999 - 2007 that involved measurement of pH, conductivity, dissolved oxygen , and turbidity every 30 minutes in the intake channel.
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 To the left is the Infiltrex automated sampling pump used to collect monthly composite samples during 1999 for herbicides and pesticides. This Tracy study used solid phase extraction and was able to obtain detection limits in the tens of picograms per liter concentration range. Highly sensitive gas chromatography - mass spectrometry methods were used by Axys Analytical, Ltd, Sidney, British Columbia to analyze the composite samples. |
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 To the right is a total ion chromatogram from the June 1999 composite sample filter extract analyzed using the open scan GC-MS . |
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