Shift to remote learning degrades water quality in buildings

Commercial and institutional buildings now experience weeks and even months with below-normal occupancy due to remote work/learning, which results in reduced water use and has the potential to adversely impact water quality. This study monitored the variations in water quality in multiple university buildings during several months of below-normal occupancy followed by several months of normal occupancy. The levels of free chlorine, copper, and cellular ATP in water varied within buildings and between buildings. Using Wi-Fi activity as a surrogate for building occupancy, the free chlorine concentration in water increased as Wi-Fi counts increased. The copper concentration in building water was higher when the occupancy was below-normal compared with normal occupancy, and the copper concentration decreased as Wi-Fi counts increased. Throughout the study, flushing a fixture at the time of use decreased the concentrations of copper and cellular ATP and increased the concentration of free chlorine.