Permeable reactive barriers have evolved since their inception in the 1980’s into a technique that is increasing applied to treat contaminated ground waters. Since the reactive media, typically granular iron is quite expensive, installation techniques that ensure the minimum plan width of the barrier, without undue waste, are favored. For installations in most soil types, with depths in the range of 3 to 30 meters, slurry trench techniques usually provide the most cost-effective construction method. In addition, trench installations provide continuity across the contaminate plume that is superior to other installation methods. The most common permeable reactive barrier (PRB) is the continuous wall. Usually a trench 0.6 to 3 meters wide is excavated while supported by bio-polymer slurry and backfilled with reactive media. Bio-polymer (BP) slurry techniques have been combined with methods borrowed from concrete diaphragm slurry wall construction to control backfill placement and minimize contamination of the media. Funnel and gates can also be installed using slurry wall techniques. Impermeable funnel sections can be created by constructing impermeable slurry walls that are connected to the reactive media installed by the bio-polymer-installed gate sections. This paper relates the experience of the authors in constructing over one-half of the nearly two dozen permeable reactive barriers installed by slurry trench methods and the success of certain construction methods. A case study is included.