Evaluation of quality assurance/quality control data collected by the US Geological Survey for water-quality activities at the Idaho National Engineering Laboratory, Idaho, 1989 through 1993

Hundreds of water samples were collected by the US Geological Survey (USGS) from 177 monitoring sites for the water quality monitoring program at the Idaho National Engineering Laboratory from 1989 through 1993. Concurrently, replicate pairs of samples and various types of blank samples were collected as part of the quality assurance/quality control program. Analyses were performed to determine the concentrations of major ions, nutrients, trace elements, gross radioactivity and radionuclides, organic compounds, and total organic carbon in the samples. To evaluate the precision of field and laboratory methods, analytical results of the replicate pairs of samples were compared statistically for equivalence on the basis of the precision associated with each result. Ninety percent or more of the analytical results for each constituent were equivalent, except for ammonia plus organic nitrogen, orthophosphate, iron, manganese, radium-226, total organic carbon, and total phenols. Blank-sample analytical results indicated that the inorganic-free blank water from the USGS Quality of Water Service Unit and the deionized water from the USGS Idaho Falls Field Office were suitable source solutions for blanks. Waters from other sources were found to be unsatisfactory as blank source solutions. Results of the analyses of several equipment blanks were evaluated to determine if a bias had been introduced and the possible sources of the bias. All of the equipment blank analytical results indicated that ammonia concentrations were greater than the reporting level. None of the equipment blanks had measurable concentrations of radioactivity. Eight percent of the analyses for inorganic constituents showed measurable concentrations were present in the blanks, nine percent for radioactive constituents, and less than one percent for organic constituents