Rapid and simple lead service line detection screening protocol using water sampling

Abstract

Many water systems are challenged with uncertainty regarding service line material type. This work investigated using a simple drinking water flushed sampling approach and a more complicated and invasive sequential profile sampling approach to predict whether homes had an existing lead service line (LSL). Homes that never had an LSL (control groups) and homes with LSLs (study groups) in two communities having different degrees of corrosion control were sampled. Using control groups' results, community-specific "threshold" lead levels were determined and compared to results from study groups.The flushed sampling maximum lead concentration (FMC) of lead accurately predicted 100% and 60% of LSL sites for the community with poor and good corrosion control, respectively. The weighted average sequential profile lead concentration (WASLC) increased the 40% not identified as LSL sites by fully flushed samples to 100%. The WASLC closely followed by the maximum sequential profile lead concentration were most reliable in identifying LSLs.

Utility considerations in developing a galvanized iron water pipe management plan

“…GIP can be a major cause of tap water discoloration due to mobilization of Fe particles from pipe scale (Clark et al, 2015; Clark & Edwards, 2016; Masters & Edwards, 2015; McGuire & Pearthree, 2018; Pieper et al, 2017; Tang, Nystrom, et al, 2018) (Figure 2). However, there are other sources of water discoloration including Fe and manganese from source water passing through the treatment facility (Schock & Giani, 2004; Tobiason et al, 2016), mobilization of legacy deposits in the distribution system (Brandhuber, 2013), and corrosion of unlined cast Fe distribution mains (McNeill & Edwards, 2001) which need to be considered when evaluating causes of discolored water. Prior research has highlighted links between high Fe and high Pb release to drinking water from GIP (Masters & Edwards, 2015; McFadden et al, 2011; Trueman et al, 2016) if there are upstream Pb pipes that have “coated” the GIP scale with Pb over decades of use (McFadden et al, 2011) and that mechanism seems to be more important than residual Pb associated with the original sacrificial zinc coating (Clark et al, 2015).…”

“…However, GIPs being one of the most unpredictable materials do not always cause Pb issues. Fresno, CA, did not have LSLs, and Pb release from GIP was usually not a problem even though discolored water was. Treatment Changes: Efforts to reduce disinfection by‐products caused discolored water and elevated Pb in water associated with GIP in Washington, D.C., when a switch was made from chlorine to chloramine disinfectant (Edwards et al, 2009; Edwards & Dudi, 2004; Edwards & Triantafyllidou, 2007; Schock & Giani, 2004; Triantafyllidou & Edwards, 2012). Conversely, in a different water quality and situation, use of chloramine was shown to dramatically reduce Fe and zinc (and Pb) release from relatively new GIP in comparison to free chlorine (Zhang et al, 2010).…”

Capture and Extraction of Particulate Lead from Point-of-Use Filters

“…Assessment of risk for lead exposure from tap water requires effective protocols for sampling lead in tap water. ,− Current sampling protocols fall into three general categories based on their objectives: lead regulatory compliance, lead source identification, and lead exposure assessment . Sampling for lead exposure assessment can be conducted at both the community- and household levels.…”