The GEO-flow HDPE pipe-leaching system from Advanced Drainage Systems promotes an oxygen-rich environment for increased biomat activity. It is composed of a 10-inch-diameter, single-wall high-density polyethylene corrugated pipe surrounded in a polypropylene grid, both encased in geotextile fabric. This design creates equal distribution and enhances the biological reduction of wastewater before it leaves this gravelless pipe system. According to the manufacturer, it has a test-proven treatment capability that supports the system sizing reductions of many state health departments. 419/424-8275; www.ads-pipe.com.