Tracking reduction of water lead levels in two homes during the Flint Federal Emergency

Understanding Failure Modes of NSF/ANSI 53 Lead-Certified Point-of-Use Pitcher and Faucet Filters

“…The highest influent lead levels in the Flint, MI, and Newark, NJ, field studies were 4080 and 1680 μg/L, respectively, and virtually none of this lead was soluble. ,, Samples with >1000 μg/L lead inevitably become a focal point of media attention and filter performance testing. ,,,, In this testing phase, the POUs were exposed to the Particulate water and two newly created particulate challenge waters (Table S2). The “High-Particulate” water had 1000 μg/L of suspended lead phosphate (>99.9% particulate), with a pH of 8.5 and an alkalinity of 100 mg/L as CaCO 3 .…”

Impact of service line replacement on lead, cadmium, and other drinking water quality parameters in Flint, Michigan

“…Indeed, presence of lead in distribution system samples taken at the tap has been attributed to the capture of lingering lead sources in premise plumbing as water is drawn from system water mains through the service line and premise plumbing. 3,20 Water lead levels in the first liter, premise plumbing, and hot water samples before service line replacement were not significantly different from two (Wilcoxon signed rank test, p-value = 0.94, 0.59, and 0.79, respectively) or five weeks after service line replacement (Wilcoxon signed rank test, p-value = 1, 0.94, and 0.094, respectively), as shown in Fig. 1b and S4.…”

“…52 Our work indicates that short-term reductions in water lead levels following LSL replacement may not be observed in regions where extensive seeding of lead in in-home plumbing has occurred; however, the beneficial removal of lead sources in the long term is evident from this work as well as from other recent work. 20 These findings must be carefully weighed by utilities and regulators in determining what is best for a community to recover and provide a reliable, safe source of drinking water.…”

“…The primary aims of these studies, however, were not focused on the short-term impact of LSL replacement, but rather on the benefits of sequential sampling methods 19 and remediation strategies. 20 An improved understanding of the impact of LSL replacement on water lead levels, particularly in the wake of a corrosion event, would aid in elucidating the benefits of conducting service line replacements. Additionally, this research would inform residents living through a corrosion event of the timeframe during which they can expect to realize benefits of full service line replacement and safely resume using distributed water.…”

Full Lead Service Line Replacement: A Case Study of Equity in Environmental Remediation

“…Water treatmentbased measures to control corrosion have played a vital role in reducing lead release into drinking water across the U.S. for decades. Nonetheless, research and experience have shown that LSLs can leach soluble lead into drinking water and unpredictably release lead particulates even in systems with corrosion control, especially when service lines are disturbed or water treatment is disrupted [11,12]. Although recent empirical work indicates that water main replacements do not increase lead levels in drinking water under all circumstances [13], water main work cannot be ruled out as a risk alongside other physical disturbances such as road repairs, building construction, and hydraulic shocks such as sudden flow changes [10,11,14].…”