Investigating dissolved lead at the tap using various sampling protocols

Abstract

The authors investigated factors influencing the occurrence of dissolved lead in tap water using different sampling protocols. The principal factor affecting the concentration of dissolved lead at the distribution system taps was the length of lead service lines (LSLs). However, dissolved lead levels in first‐litre samples were also associated with lead particles being trapped in the aerator. Collecting the first‐litre sample after 30 min of stagnation provided a good estimate of lead concentration in premise plumbing and LSLs, even though it could sometimes underestimate peak lead concentrations in the LSLs. Also it gives mean exposure estimates close to that obtained using random daytime sampling. Lead levels remained relatively high in flushed samples despite short (26‐s) contact time between the water and lead pipe, illustrating high rates of mass transfer.

Distribution system water age can create premise plumbing corrosion hotspots

“…In the past, selection of Bworst case^sites has focused exclusively on identifying homes with the highest propensity to leach lead from plumbing based on a tier system of age and lead-bearing materials that are present in homes (Ferguson et al 1996;Broo et al 1997;Edwards et al 2001a, b;Rajaratnam et al 2002;Schock and Sandvig 2009;Turek et al 2011;Grace et al 2012). It has recently been acknowledged that other risk factors in homes can be of equal or greater importance including the length of lead service lines (Kuch and Wagner 1983;Cardew 2006;Cartier et al 2011), whether the service line has been disrupted by a partial replacement or other activities (Boyd et al 2004;Sandvig et al 2008;Triantafyllidou and Edwards 2011;Cartier et al 2012;Del Toral et al 2013), and even water use rates in the home Del Toral et al 2013). This research unambiguously demonstrates that the location of a home in a given water distribution system can also influence lead leaching, creating hotspots of corrosion that are associated with a greater incidence of childhood lead poisoning and even fetal death (Stith et al 2006;Renner 2006;Gronberg 2007;Edwards et al 2009;HDR 2011;Wang et al 2014a, b;Edwards 2014).…”

Lead (Pb) quantification in potable water samples: implications for regulatory compliance and assessment of human exposure

“…There is no current accepted protocol for collection and preparation/pre-treatment of tap water samples for Pb monitoring that is universally followed (Cartier et al 2011). The interpretation of results when using different protocols for monitoring, coupled with the inherent variability of Pb in water, remain big challenges (Schock and Lemieux 2010;Schock 1990).…”

Systematic evaluation of dissolved lead sorption losses to particulate syringe filter materials

“…Many different filter materials have been used. For example, Cartier et al (2011) and Deshommes et al (2010) used 33-mm-diameter 0.45-μm polyvinylidene fluoride (PVDF) cartridge filters to distinguish between particulate and soluble lead in tap water samples. Wang et al (2012) used 0.22 polyethersulfone (PES) syringe filters to separate dissolved lead in lead(IV) oxide formation studies.…”