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Rapid and Simple Lead Service Line Detection Screening Protocol Using Water Sampling
Citation:
Schock, M., D. Lytle, R. James, V. Lal, AND M. Tang. Rapid and Simple Lead Service Line Detection Screening Protocol Using Water Sampling. AWWA Water Science. John Wiley & Sons, Inc., Hoboken, NJ, 3(5):e1255, (2021). https://doi.org/10.1002/aws2.1255
Impact/Purpose:
The primary objective of this work was to investigate the feasibility of using simple drinking water fully-flush sample collected at low-high flow rates to predict whether a given site had an existing LSL. Secondarily, the use of more complicated and invasive but potentially more accurate sequential profile water sampling approach was explored, to identify the presence of LSLs not captured by the flush sampling methodology.
Description:
Lead service lines (LSLs), when present, represent the largest lead mass source in drinking water. Therefore, to reduce lead exposure risks from drinking water, many communities that have knowledge of LSLs in their distribution system have initiated removal programs. A major challenge with such programs is that a large amount of uncertainty regarding service line material type often exists because of poor records and other factors. Therefore, a very great need to identify a relatively simple, quick, and effective approach to aid drinking water systems in accurately identifying service line material is needed. Such an approach will help drinking water systems develop LSL inventories, prioritize LSL removal programs, and ultimately protect public health. The primary objective of this work was to investigate the feasibility of using simple drinking water fully-flush sample collected at low-high flow rates to predict whether a given site had an existing LSL. Secondarily, the use of more complicated and invasive but potentially more accurate sequential profile water sampling approach was explored, to identify the presence of LSLs not captured by the flush sampling methodology. Fully-flushed and sequential profile sampling was performed in homes that never had a LSL (control groups), and homes with LSLs pre- and post-LSL removal in two communities having different degrees of corrosion control effectiveness. Using sampling results from the control groups, community specific “threshold” lead levels with and without multiplier safety factors were determined and compared to results from homes with LSLs. The results showed that simple fully-flushed sampling accurately predicted 100% and 60% of LSL sites for the community with poor and good corrosion control, respectively. Comparison of sequential profile parameters increased the 40% not identified as LSL sites by full-flushed samples to 100%. A weighted average lead concentration parameter closely followed by the maximum lead concentration from the sequential profiles were most reliable in identifying LSLs. Applying increasing safety factors decreased accuracy but, in practice, would decrease the likelihood of false positive results.
URLs/Downloads:
DOI: Rapid and Simple Lead Service Line Detection Screening Protocol Using Water Sampling
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