At head of title: Project Summary. "May 1989." "EPA/600-S4-88-040."

This report is a discussion of decision rules relating to the monitoring of ground water at hazardous waste sites that are subject to regulation under the Resource Conservation and Recovery Act of 1976 (RCRA). The final rule for RCRA regulations 40CFR part 264 was published October 11, 1988 (53FR39720). Understanding the complexity of the monitoring problem and the diversity of RCRA sites, the final rule wisely allows the owner/operator to choose, conditioned on EPA approval, a site-specific "statistical procedure." Analysis-of-variance, tolerance intervals, prediction intervals, and control charts are included as acceptable methods for "statistical procedures." These methods are discussed to facilitate the choice of decision rules. A nested random-effects model for ground-water quality parameter measurement is suggested and decision procedures are developed in terms of that model. Particular attention is paid to the possible application of industrial quality control strategies to the ground-water monitoring problem. A decision procedure that changes over time as more information about well and aquifer characteristics accumulate is proposed. This procedure involves the use of outlier tests and of Shewhart-CUSUM quality control strategies.