Phase 2 of Drainline Transport Study set to go

The Plumbing Efficiency Research Coalition (PERC) has announced the publication of the Work Plan Proposal for Phase 2 Drain Line Transport Study. Phase 2 builds upon the results of its Drainline Transport of Solid Waste in Buildings report, which was released in November 2012. The original study raised new questions, providing an opportunity for further research. Phase 2 will be focused on the following research areas: pipe size reduction, additional flush volume levels, toilet discharge and toilet paper characteristics. PERC is now seeking information from individuals on their experiences with commercial building drainline blockages that have been attributed directly to the installation or retrofit of high efficiency toilets (1.28 gallons per flush or lower).

PERC was formed in January 2009 through a Memorandum of Understanding (MOU) to develop research projects that support the development of water efficiency and sustainable plumbing products, systems and practices. Organizations in the Coalition are: Alliance for Water Efficiency (AWE); American Society of Plumbing Engineers (ASPE); International Association of Plumbing and Mechanical Officials (IAPMO); International Code Council (ICC); Plumbing- Heating-Cooling Contractors National Association (PHCC); and Plumbing Manufacturers International (PMI).

“It’s critically important that we gain a better understanding of how building drains perform as flows from plumbing fixtures, appliances and commercial equipment are reduced and toilet fixtures become increasingly stressed to singularly transport solid waste to sewers. This study identifies the controllable variables in the building drain system, such as slope, flush volume, toilet paper selection and toilet discharge attributes, and examines their relative significance on performance.” said Pete DeMarco, who acted as the technical director for the original study.

The Energy Policy Act of 1992 requires that all water closets (toilets) manufactured in or imported into the United States flush using no more than a maximum average of 1.6 U.S. gallons (6.0 Liters). This change was made without assessing the impact on drainline transport. After this law went into effect on January 1, 1994, new models were introduced, with a significant number of consumers reporting poor flush performance. Initial research focused on flush efficacy, not the transport of that waste through drainline systems built using common designs and materials. Toilet manufacturers have since made improvements in flushing performance for 1.6 gallons per flush (gpf), 1.28 gpf, 1.0 gpf and 0.8 gpf products. In light of changes to further reduce water consumption, the coalition felt there was a need to better understand the function of drainlines, how these systems perform, and which controllable variables impact performance.