The Eastern Lake Survey, Phase II was designed primarily to assess seasonal variability in regional surface water chemistry. The report describes and evaluates the quality assurance program employed during the survey. The operations component included quality assurance and quality control procedures to ensure that all samples were collected and analyzed consistently and to estimate the accuracy and precision of the reported values with a known degree of confidence. The data management component established a means to store and track data; to identify and correct entry, reporting, and analytical errors; and to keep a record of such changes. The survey design identified 24 physical and chemical characteristics of lake water for measurement. Data quality objectives for detectability, accuracy, precision, representativeness, completeness, and comparability of ELS-II were based on previous related surveys. During data verification and validation activities, several issues (concentrated primarily on the data from the chloride, nitrate, sulfate, and alkalinity analyses) prompted a Special Data Assessment. The process produced a list of recommendations and justifications for changes to be made to the official verified data base.

"EPA/600/4-89/029." "July 1989." " ... contract no. 68-03-3249 to Lockheed Engineering Sciences Company ..."--Title page verso. " ... cooperative agreement no. 812189-03 to the Environmental Research Center of the University of Nevada at Las Vegas."--Title page verso. Includes bibliographical references (pages 68-69).