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.
The 258 organic compounds in this assessment are man-made: pesticides, solvents, gasoline hydrocarbons, personal-care and domestic-use products, pavement and combustion-derived compounds. None were found in concentrations deemed dangerous at this time.
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.
Explains why phosphorus is important, how it moves through the terrestrial water system, how we measure it, and what this means for people who need to manage or monitor human activities that produce it.