for a total of 21,600 linear feet of pipe. "We used HP Storm pipe, and it is essentially the largest French drain we ever designed. The three 60-inch diameter pipes are side-by-side in a 26-foot-wide trench, and the bottom of the pipe is about 10 feet below grade so there's approximately four feet on top," Wiggins continued. "The pipe is perforated all around with 3/8-inch holes. Before, the steel pipe didn't have any pre-drilled perforations - the only perforations were the broken joints." The HP Storm pipe from Advanced Drainage Systems Inc. is high-performance polypropylene (PP) pipe for gravity-flow storm drainage applications. The ADS design couples ad- vanced polypropylene resin technology with a dual-wall profile design for greater stiffness and durability. The pipe is corrosion resistant and is unaffected by salts, chemicals and hot soils. It also meets or exceeds ASTM F2881 and AASHTO M330. From a federal perspective, polypropylene pipe is approved by the Army Corps of Engineers for storm drainage applications under Section 33 40 00 (Unified Facilities Guide Specifications). The Federal Aviation Authority (FAA) permits polypropylene pipe under airfield pavements per Item D-701, Pipe for Storm Drains and Culverts in AC 150/537010G (Standards for Specifying Construction of Airports). "It's also a particularly strong More than 21,000 linear feet of 60-inch-diameter pipe was placed in the 26-foot wide trench to create a French drain to provide drainage between two active U. S. Air Force runways at Sheppard Air Force Base. Tough Drilling Demands HDD DRILL PIPE ALL MAKES & MODELS www.tuffrod.com | 844-586-9354 UConOnline.com | OCTOBER 2018 23http://www.tuffrod.com http://www.UConOnline.com