AWWA WQTC69454

This powerpoint presentation begins by providing a brief overview of green construction and bacterial growth. The University of North Carolina (UNC) Problem Identification in New Construction includes: taste and odor complaints after occupancy of two buildings; first draw samples had undetectable disinfectant levels; and, testing to evaluate disinfectant issue. Suspected factors contributing to chloramine loss included: excess residence time; high water temperatures (18-30ºC); and, new copper pipe. Remediation efforts included: increased water turnover to raise chloramine residual on a case-by-case basis; automated flushing system (accounts for < 1% of total water use); and, replaced water fountains with integral chiller units to reduce water temperature. Presentation conclusions indicate the following: construction practices that incorporate water conservation in plumbing can cause aesthetic problems if design is not changed to control residence time; rapid chloramine decay in new plumbing and warmer temperatures can cause high bacterial growth; and, more research is needed on effects of materials and on plumbing design and re-growth to avoid problems. Includes figures.