Toilet paper biggest problem for commercial drainlines
The Plumbing Efficiency Research Coalition (PERC) has announced that its second report, The Drainline Transport of Solid Waste in Buildings – Phase 2.0, has been released and is now available on the PERC website:
The study builds on the findings of the Phase 1 report of the same title and provides new and important insights into the performance of building drains as water flows are incrementally reduced as a result of water efficiency related regulations.
The PERC Phase 2.0 report addresses several important areas of study that were not included in the Phase 1 effort. Importantly, the study evaluates the potential for a sanitary pipe size reduction to improve drainline transport characteristics and help to facilitate further flow reductions in plumbing fixtures. As with the Phase 1 report, the study applies to commercial building drains, as they present the greatest risk for chronic blockages resulting from water flow reductions.
The PERC Phase 1 study was both informative and influential. In 2013, the U.S. Environmental Protection Agency cited the report’s findings that high efficiency toilets (HETs) flushing at a maximum of 1.28 gallons per flush provided satisfactory drainline transport as justification to move forward with a WaterSense specification for commercial HETs and flushometer valves.
Phase 2.0 provides insights regarding conditions that can trigger a tipping point where incremental flow reductions are increasingly likely to result in chronic drain blockages in commercial buildings. The findings also detail the surprising significance of toilet paper in drainline transport, relative to other variable factors such as drainline slope, pipe diameter, and toilet flush volume levels.
PERC feels that the Phase 2.0 report will provide new and valuable insights to the engineering community, plumbing trades, facility managers, and regulators regarding the continued efficacy of sanitary building drains as we seek to make our plumbing systems as efficient as possible while maintaining health and safety.