Homepage for description of the National Stream Quality Network (NASQAN), a long-term program monitoring the concentrations and flux of sediment and chemicals in the Nation's largest rivers (Mississippi, Columbia, Colorado, Rio Grande, and Yukon).
Project to assess the grizzly bear population size, trend, and survival in the Northern Continental Divide Ecosystem (NCDE) in Montana to improve the long-term survival for this threatened species. With description, DNA identification means and photos.
Results (*.pdf) of a 1998 targeted reconnaissance survey on the sources of radium, polonium, and lead radionuclides, data collection and laboratory methods, existing occurrences in drinking water, risk assessments, and compliance monitoring.
In all, 56 compounds were detected in samples collected approximately monthly during 2003-05 at the intake for the Clackamas River Water plant. On the basis of this screening-level assessment, adverse effects to human health are assumed to be negligible.
We identified six compounds at concentrations less than human-health benchmarks, but within a factor of 10 of those limits. Those compounds might warrant further study to understand their transport and fate within the watershed.
Measured concentrations of many compounds in water people use. Some compounds are regulated as health hazards; a few of these were over the benchmark limits. Others may become issues of concern, so studies such as this give us helpful background levels.