Using the Lead and Copper Rule Revisions Five-Sample Approach to Identify Schools with Increased Lead in Drinking Water Risks

Abstract

Despite public concern, the risk of lead exposure from schools remains poorly understood. The Lead and Copper Rule Revisions (LCRR) include, for the first time, a five-sample lead testing requirement for all elementary schools. However, the United States Environmental Protection Agency does not define school-wide lead risk or provide clear guidance on how results should be interpreted. Using the Massachusetts Lead in School Drinking Water Database, we explored the application of the LCRR sampling approach and provide insight into the magnitude and distribution of lead in water in Massachusetts public schools. We observed that 12% of fixtures had first draw lead >15 ppb and 3% after a 30 s flushing. Approximately 90% of fixtures with lead >15 ppb were clustered in 34% of schools. We determined a school-wide 90th percentile of 10 ppb closely approximated this clustering of problem fixtures and were able to identify schools with problem fixtures using the five-sample results with a confidence >90%. Fixtures releasing lead >1 ppb occurred in >90% of schools and represented 58% of first draws and 33% of 30-s flushed samples. Overall, our study provides an approach to classify a school's lead risk, which could help water utilities and schools prioritizing testing and remediation efforts.

Improved Decision Making for Water Lead Testing in U.S. Child Care Facilities Using Machine-Learned Bayesian Networks

“…The most conservative measure of building-wide risk is, therefore, whether any tap within the building exceeds the chosen risk level. Another alternative to the average that better captures potential outliers and has been proposed as a useful benchmark for identifying facilities where high-risk taps are clustered is the building-wide 90th percentile value . Thus, we created binary exceedance variables based on whether the maximum or the 90th percentile first-draw lead concentration for each facility exceeded various levels.…”

“…Another alternative to the average that better captures potential outliers and has been proposed as a useful benchmark for identifying facilities where high-risk taps are clustered is the building-wide 90th percentile value. 30 Thus, we created binary exceedance variables based on whether the maximum or the 90th percentile first-draw lead concentration for each facility exceeded various levels. The spatial variability in maximum water lead concentrations across the state can be seen in Figure 1.…”

“…Previous studies have used the average lead level in a building to determine risk, 11,28 but average levels could mask the overall risk to children and students in a building from clusters of outlier taps or even single taps. Indeed, extremely high variability from tap to tap should be expected within schools 6 and child care facilities. 7,8 The assumption that the average lead level represents actual exposure to children because of equal consumption across all taps within a building, as previously posited, 11 is also not supported by lead exposure assessments.…”

“…To best protect public health, facilities with the greatest need and highest risk must be prioritized for lead testing, risk communication, and mitigation. Research has shown, however, that lead occurrence in drinking water in schools and child care settings can be highly variable from one tap or building to the next, − thus making it notoriously difficult to predict. Water lead risk is commonly determined according to simple binary heuristics or risk factors such as building age despite evidence that lead occurrence in drinking water is a complex function of infrastructural, operational, chemical, historical, socioeconomic, and demographic factors that influence both the presence of lead in premise plumbing components and corrosion risk. ,− To optimize resources and protect children’s health, public health practitioners, policy makers, educators, and community water system managers need improved methods for predicting water lead risk in schools and child care settings that balance this complexity with the ease of implementation that simple heuristics provide.…”

Water lead levels in Massachusetts schools and early education and childcare facilities

“…While in Massachusetts, PWSs are now required to sample from two schools during each round of sampling (MassDEP DWP, 2023), federal legislation has not required monitoring for lead at schools (Lambrinidou et al, 2010), but prior school studies show it is not uncommon for schools to have fixtures with WLLs >15 ppb (Boyd et al, 2008; Bryant, 2004; Carter et al, 2020; Latham & Jennings, 2022; Massey & Steele, 2012). Other recent studies in Massachusetts have used the Massachusetts Environmental & Energy Affairs (EEA) Lead and Copper Drinking Water Results in Schools/Childcare (2021) database (Lobo et al, 2022; Ram, 2019; Rome et al, 2022) or Massachusetts LCR data (Lu et al, 2022) as sources of WLL data. As monitoring in schools continues to grow with the implementation of the LCRR, we present the current conditions in Massachusetts and future considerations for monitoring and action to add to recent studies of WLLs in schools nationwide (Carter et al, 2020; Cradock et al, 2022; Latham & Jennings, 2022; Lobo et al, 2022; Olson & Pakenham, 2021; Redmon et al, 2020; Spiegel et al, 2022; Stanbrough et al, 2022).…”