Understanding the Impacts of Building Design and Use on Potable Water Quality Through Enhanced Monitoring

The intent of this dissertation was to advance the knowledge of the impacts of building design and use on the quality of the potable water. Fluctuations in water use by occupants and equipment can cause stagnant conditions that causes water quality decay such as loss of chlorine disinfectant, an increase in microorganism and pathogen growth, an increase in metals concentrations, and an increase in disinfection byproducts. The United States Environmental Protection Agency has drinking water standards for distribution systems, but these standards stop at the meter with exception of the Lead and Copper Rule. There are also building codes to ensure proper plumbing materials are used that come in contact with potable water. However, neither standards nor codes require building water quality monitoring. Therefore, monitoring the building potable water system is an important aspect of building water quality that is not done on a large scale.Chapter 2 investigated how water quality evolved in a “green”, multi-story, institutional building during the first 6 months of building life. The results indicated that Wi-Fi logins could be used to correlate occupancy activity and copper (Cu) concentrations in water. As occupancy activity increased, Cu concentrations decreased. However, chlorine (Cl2) residual (or free chlorine) was only measurable twice at two kitchen sinks via grab sampling during the duration of the 6-month study regardless of occupancy activity. Chapter 3 provided improved understanding of how to carry out effective building water sampling (e.g., grab samples vs real time) and which water quality parameters were most influenced by the building water system during the first year of occupancy in relation to municipal water quality. The results showed the temperature (T), pH, UVA254, a surrogate for organic matter, cellular adenosine triphosphate (cATP), trihalomethanes (THMs), and Cu were always greater inside the building than at building entry while free Cl2 was always lower inside the building than at the building entry. Chapter 4 investigated a remedial flushing program for three schools. Overall, the study showed the quality of water does change after a flushing event. Free Cl2 was reestablished, and metals concentrations decreased. However, equipment flushing, such as hot water heaters, may be necessary to fully remediate Legionella. Lastly, one-time flushing is most likely a temporary solution. A more routine approach to building flushing and monitoring may be necessary until normal or sustained occupancy resumes.