Assessments of the quality of individual measurements are included in the data as ancillary attributes; the report refers to these as "qualifier fields."
"0" in a concentration field means that the constituent was analyzed and found to have a concentration below the detection limit for the method utilized.(Zeros are different, therefore, from blank fields, which show that the constituent was not measured). Other remarks in the quality-control fields provide comments relating to the data that may be helpful in interpreting or further evaluating the data.
Environmental issues include linking the chemical data to bulk sediment toxicity criteria, searching for possible contaminant sources, and identifying transport and geochemical processes. The in-depth inventory and assessment was only possible with the help of many partners and cooperators.