Trace Element Analysis, Model-Based Clustering and Flushing to Prevent Drinking Water Contamination in Public Schools

Abstract

Drinking water samples taken from cafeteria sinks and water fountains in each of the 76 schools in the Winston-Salem/Forsyth County Schools (WSFCS) district (North Carolina, United States) were analyzed by inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) to determine As, Cd, Cr, Cu, Pb, Sb, Se and Tl. All samples from currently active schools tested below the maximum contaminant level (MCL) set for each element. Model-based clustering was employed to identify schools more prone to drinking water contamination. This multivariate approach may be used in a prevention program that can be tailored to specific school districts, with each school tested at a frequency compatible with its contamination risk level. Water flow stagnation during the summer break results in higher elemental concentrations in school drinking water, but a simple 5-60 min flushing procedure significantly reduces the contamination levels.

Survey of Lead in Drinking Water from Schools and Child Care Centers Operating as Public Water Suppliers in North Carolina, USA: Implications for Future Legislation

“…In this context, lawmakers have introduced two different bills to the North Carolina House of Representatives to regulate Pb testing in school and child care drinking water, and the EPA has proposed revisions to the LCR requiring Pb testing in schools and child care centers that are not public water suppliers. − NC House Bill 1074 mandates public elementary schools and child care centers built before 1987 to test drinking water for Pb, and NC House Bill 386 includes all public schools and child care facilities built before 1991 as Pb testing targets . In anticipation of these bills, several school districts and child care centers within NC have implemented voluntary water testing, which included selected taps and involved partnerships with local research organizations or hired contractors. − As observed in previous surveys, the studies carried out in Guilford County Schools and Charlotte Mecklenberg Schools, for example, identified several samples with Pb concentration above the LCR action level (15 μg/L). , …”

Physical, Chemical, and Microbiological Water Quality Variation between City and Building and within Multistory Building

“…The building water system may be comprised of treatment equipment, instruments, valves, pumps, piping, and fixtures . While many studies exist on transient water quality in the city pipe network and private homes, − and influence of premise plumbing on critical water quality parameters (e.g., lead), there is much less information available on large commercial and institutional buildings (e.g., office buildings, hospitals, hotels). Water use patterns within the building and premise plumbing configurations can vary across different types of buildings.…”

Shift to remote learning degrades water quality in buildings

“…As buildings fluctuate between periods of below‐normal and normal occupancy, water quality studies are needed to understand how building water systems are behaving. Previous studies have monitored water quality in homes (Casteloes et al, 2015; Ragain et al, 2019; Salehi et al, 2018, 2020), schools (Aw et al, 2022; Carter et al, 2019; Doré et al, 2018; Ra et al, 2020; Rhoads et al, 2015; Richard & Boyer, 2021; Ye et al, 2022), and commercial and institutional buildings (Doré et al, 2018; Dowdell et al, 2022; Montagnino et al, 2022; Oliver et al, 2021; Proctor et al, 2020; Rhoads et al, 2015; Richard et al, 2020) considering factors such as occupancy, flushing, and plumbing materials. However, there is a gap in the literature extending the observations from one home or building to multiple buildings served by the same water system.…”

“…However, there is a gap in the literature extending the observations from one home or building to multiple buildings served by the same water system. For example, only four papers (Carter et al, 2019; Logan‐Jackson & Rose, 2022; Oliver et al, 2021; Richard & Boyer, 2021) have studied more than one building, however, it was not clear if the buildings were supplied by the same city distribution system. Studying water quality in multiple buildings is needed to formulate more generalizable conclusions about building water systems and guidelines to manage the systems.…”

“…Although flushing can be used as a short‐term solution for degraded water quality, many fixtures are not flushed regularly, and the amount of time needed to fully flush a single fixture can be hours (Nguyen et al, 2011). There is also a lack of guidance on how frequent and how long flushing should be conducted with only a few studies published on the topic (Carter et al, 2019; Casteloes et al, 2015; Ragain et al, 2019).…”