Styrofoam back-filled pipe is the latest golf drainage concept. A salesman recently gave me a three-foot sample of 4” HDPE drain pipe covered with six inches of Styrofoam popcorn and wrapped with a black mesh fabric.
I’ve installed golf course drainage since high school and my preferred methods have evolved from crushed stone to coarse sand back-fill.
I had a callback when I installed my first sand back-filled drainage system. It was a minor design problem and the engineer paid us to dig up a complex intersection where a new pipe intersected two older pipes that still carried water. While performing the repair, I had to put my face in the ditch, a few inches from the back-fill sand I had installed a few months before. I examined the back-fill sand and found that it blocked all of the fines at the trench wall and beginning of the sand. I kept a section of back-filled pipe intact and looked inside with a flashlight. Plenty of water was flowing past this sand silt layer into the pipe.
Styrofoam back-fill seems to bring golf drainage back to the crushed stone era; a time when fines slid past big gaps in the stone and clogged perforated pipe making it useless. Before using this material, I’d also consider the potential for Styrofoam back-filled pipe floating out of the ground, especially when installed in a bunker.