Publisher's Synopsis
Implementation of the Lead and Copper Rule (LCR) has resulted in significant reductions in first liter standing lead levels measured at the tap in the United States. However, there are still utilities that have implemented optimal treatment but may still experience lead levels at or near the action level for lead, or those that would like to go a step further in reducing lead levels measured in their system by proactively replacing lead source materials. For these utilities, and water works and regulatory communities as a whole, an understanding of the contributions that various lead based materials may have on lead levels measured at the tap would be useful.
The objective of this research project was to evaluate the contribution of lead service lines and utility and customer-owned plumbing components to Lead and Copper Rule (LCR) compliance issues. The results of this project also address the broader long-term goals of moving the industry towards a new "lead free" future and providing information that can be directly applied to future regulatory reviews of the LCR. This project utilized information from historical literature, conducted a national survey of lead source characteristics, completed case studies of lead source removal and corrosion treatment effectiveness, and completed field and pilot study activities designed to estimate the contributions of various lead sources to lead levels measured at the tap. This information was used to evaluate the relative contribution of various lead sources to lead levels at the tap and how these contributions might affect compliance with the LCR. In addition, an assessment of the impact of pipe cutting tools was completed to provide guidance on the best methods for removing lead service lines. The composition of scales built up on lead source materials was evaluated to expand the knowledge base related to identification of compounds that form on leaded materials in drinking water systems and correlations between these scales and distributed water quality conditions.
