This report discusses soil and ground-water sampling methods and procedures used to evaluate the long-term performance of permeable reactive barriers (PRBs) at two sites, Elizabeth City, NC, and the Denver Federal Center near Lakewood, CO. Both PRBs were installed in 1996 and have been monitored and studied since installation to determine their continued effectiveness for removing contaminants from ground water. An effective monitoring program requires appropriate soil and ground-water sampling techniques. For ground-water sampling, water quality indicator parameters must be monitored to determine when formation water has been accessed. Geochemical parameters include oxidation-reduction potential (ORP), pH, specific conductance, dissolved oxygen (DO), and turbidity. Field analytical methods are discussed along with interferences and issues which may arise when using certain electrodes or instruments in the field. Detailed field analytical procedures for hexavalent chromium, ferrous iron, alkalinity, hydrogen sulfide, and dissolved oxygen are described. Also included are laboratory methods for sample analyses for organics, cations, anions, and carbon. Sample collection methods, sample containers, preservation methods, and sample storage techniques are also discussed.

"August 2003." Includes bibliographical references (p. 47-48.). "EPA/600/R-03/045b."