Date
Monday, July 28, 2025
Time
1:30 PM - 2:00 PM
Location Name
Room 301C
Name
A Selection Framework for Effective Lead Sampling in Drinking Water: Methods and Comparisons
Track
Distribution
Description
Water utilities have numerous reasons to sample drinking water for lead, including regulatory compliance with the U.S. Environmental Protection Agency's (EPA) Lead and Copper Rule (LCR) and its improvements (LCRI), customer requests, water quality parameter (WQP) monitoring, post-lead service line (LSL) replacement sampling, sampling in schools and childcare facilities, post-disturbance sampling, and service line identification and verification sampling. The needs are complex, and selecting the most appropriate approach can be overwhelming for utilities. In some cases, sampling methods are clearly stated, whereas in most cases, sampling methods are left to the discretion of the water utility. This flexibility allows for the selection of the best sampling method that most accurately and scientifically defensibly answers the desired lead question while considering costs, flexibility, customer challenges, and messaging. Given the many reasons to sample for lead, it is essential to connect the sampling goal with the appropriate sampling approach, of which there are many. Therefore, the objective of this presentation is to review the various reasons a water utility would need to sample drinking water for lead and match the need with the best sampling approach to achieve the desired goal. There are various lead drinking water sampling options available. The fixed volume 1st (and soon to be added 5th liter) samples are the regulatory requirement of the LCR and LCRI. The industry's familiarity with regulatory sampling has led many to use it to answer all lead-related drinking water questions. However, the fixed-volume sample has challenges and limitations. For example, regulatory sampling is often misapplied to assess lead exposure, resulting in improper estimates of lead exposure and public safety messaging confusion. Sequential profile (SP) sampling can identify the type of plumbing material and the location of LSL in a home plumbing and service line network. Fully flushed (FF) samples have been used to identify the presence of LSLs in plumbing networks and reflect the lowest lead level expected in the home. Manual composite (MC) and passive sampling devices (PSD) have been used to estimate lead exposure over 1-3 days to months, respectively. Furthermore, random daytime (RDT) sampling reflects community-wide lead exposure and forms the regulatory framework in several European countries. This presentation will provide an overview of the various reasons a water utility needs to sample water for lead in drinking water. It will describe lead water sampling methods, including a review of their protocols. Sampling methods will be appropriately matched with the questions to be addressed, and explanations will be provided. Comparisons and analyses of differences in lead levels between some sampling approaches in two communities—with and without effective corrosion control, and in homes with and without lead service lines—will be made to illustrate key points. Lastly, experiences regarding the ease of sampling and resident compliance will be shared. The sampling framework described in the presentation will expand the industry’s knowledge and perspective on water sampling for lead and serve as a foundation for future work.