Four buildings and a flush: Lessons from degraded water quality and recommendations on building water management

Kyungyeon Ra; Caitlin Proctor; Christian Ley; Danielle Angert; Yoorae Noh; Tolulope Odimayomi; Andrew J Whelton

doi:10.1016/j.ese.2023.100314

Four buildings and a flush: Lessons from degraded water quality and recommendations on building water management

Environ Sci Ecotechnol. 2023 Sep 20:18:100314. doi: 10.1016/j.ese.2023.100314. eCollection 2024 Mar.

Authors

Kyungyeon Ra¹, Caitlin Proctor², Christian Ley^{3

4}, Danielle Angert^{3

5}, Yoorae Noh¹, Tolulope Odimayomi^{3

6}, Andrew J Whelton⁷

Affiliations

¹ Lyles School of Civil Engineering, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN, 47907, USA.
² Agricultural and Biological Engineering, Division of Environmental and Ecological Engineering, Purdue University, West Lafayette, IN, 47907, USA.
³ Division of Environmental and Ecological Engineering, Purdue University, West Lafayette, IN, 47907, USA.
⁴ Civil and Environmental Engineering, University of Colorado, 1111 Engineering Drive, Boulder, CO, 80309, USA.
⁵ Civil, Architectural and Environmental Engineering, University of Texas, 301E E Dean Keeton Street, Austin, TX, 78712, USA.
⁶ Civil and Environmental Engineering, Virginia Tech, 750 Drillfield Drive, Blacksburg, VA, 24061, USA.
⁷ Lyles School of Civil Engineering, Division of Environmental and Ecological Engineering, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN, 47907, USA.

Abstract

A reduction in building occupancy can lead to stagnant water in plumbing, and the potential consequences for water quality have gained increasing attention. To investigate this, a study was conducted during the COVID-19 pandemic, focusing on water quality in four institutional buildings. Two of these buildings were old (>58 years) and large (>19,000 m²), while the other two were new (>13 years) and small (<11,000 m²). The study revealed significant decreases in water usage in the small buildings, whereas usage remained unchanged in the large buildings. Initial analysis found that residual chlorine was rarely detectable in cold/drinking water samples. Furthermore, the pH, dissolved oxygen, total organic carbon, and total cell count levels in the first draw of cold water samples were similar across all buildings. However, the ranges of heavy metal concentrations in large buildings were greater than observed in small buildings. Copper (Cu), lead (Pb), and manganese (Mn) sporadically exceeded drinking water limits at cold water fixtures, with maximum concentrations of 2.7 mg Cu L^-1, 45.4 μg Pb L^-1, 1.9 mg Mn L^-1. Flushing the plumbing for 5 min resulted in detectable residual at fixtures in three buildings, but even after 125 min of flushing in largest and oldest building, no residual chlorine was detected at the fixture closest to the building's point of entry. During the pandemic, the building owner conducted fixture flushing, where one to a few fixtures were operated per visit in buildings with hundreds of fixtures and multiple floors. However, further research is needed to understand the fundamental processes that control faucet water quality from the service line to the faucet. In the absence of this knowledge, building owners should create and use as-built drawings to develop flushing plans and conduct periodic water testing.

Keywords: COVID-19 pandemic; Drinking water quality; Flushing; Stagnation.

Grants and funding

R836890/EPA/EPA/United States