Methods for Quality-Assurance Review of Water-Quality Data in New Jersey;Open File rept

摘要

This report is an instructional and reference manual for USGS personnel who conduct quality-assurance reviews of water-quality data. The methods used in the USGS, New Jersey District, to ensure that the results of analyses of surface-water and ground-water samples are internally consistent and are reasonable within the historical context for a particular sampling site are explained. The use of a statistical-analysis computer program is described. The interpretation of the programs three output files is described in detail, and criteria are presented to help the data reviewer determine whether to investigate questionable data values. The use of regression analysis as a tool to evaluate the validity of questionable data values also is described. Although examples in the report are specific to New Jersey, many suggestions are offered that are applicable to the review of the results of analyses of water samples collected at any location. Services offered by the USGS National Water Quality Laboratory and instructions for obtaining these services are included.