Granular activated carbon (GAC) pressure contactors from WesTech Engineering are an effective means for removal of various molecular-weight contaminants from aqueous solutions. They are suited for the removal of dissolved organic compounds responsible for poor taste and odor in drinking water, as well as removal of a variety of contaminants that can be found in industrial and municipal waters. The contactors can be supplied in an open-top gravity system or in pressure vessels. They are typically designed with a conical underdrain for convenient GAC replacement. They are sized according to the contact time required for contaminant removal and desired media replacement frequency. Filter piping and valving for multiple units can be arranged to easily change flow paths between parallel flow, series (lead/lag or daisy chain) flow, or single-unit flow patterns. They are typically backwashed once upon new media installation, and the media usage front is then monitored via sample taps to allow for anticipation of media replacement. 801/265-1000; www.westech-inc.com.