Fig 1.
The building water system, including service line, based on drawings and experience.
Fire systems, irrigation systems (rainwater), and toilets (rainwater/separate piping system) are not included. Pipes should only be considered vertical when they cross a floor line (i.e., horizontal physical space is necessarily using a vertical schematic representation here). On-demand water heaters are used, so cold water lines provide water almost all the way to sinks.
Table 1.
Locations sampled, with numbers corresponding to sample order and other figures.
Table 2.
Timeline of the study sampling.
Fig 2.
Usage frequency at each location throughout the study.
Week 2 (starting 1/20/2020) included a government holiday on Monday. Sampling took place over the weekends following weeks 2, 3, and 4. A* is a sink with the same bathroom as Location 3, which was never sampled. B* is a sink in a bathroom next to Location 7, which was never sampled. Location 1 was the point of entry and is not shown because there is no use at this point. More location descriptions can be found in Table 1.
Fig 3.
(a) Total cell count (TCC) concentration, (b) chlorine residual concentration, and (c) Legionella spp. concentration detected at each location (locations 1–12, grouped by floor) on the six days of sampling. Fridays (black) and the following Mondays (white) are presented in order. The first bar is sampling event 1 (black), then 2 (white), and so on. Riser and floor information is provided for each location and further location descriptions can be found in Table 1, and sample events are described in Table 2.
Table 3.
Range of copper and lead concentrations at each fixture on Friday and Monday sampling events, with all Friday and Monday samples grouped (n = 3).
Fig 4.
(a) Location 4 flushing event, copper, total chlorine and total cell count (TCC) concentrations and (b) subsequent six-hour stagnation period where copper, total chlorine and TCC concentrations were monitored each hour. Note that graphs in a and b have different scales, and that graph a has a non-linear time scale.