Mineralogical Evidence of Galvanic Corrosion in Drinking Water Lead Pipe Joints

The importance of galvanic corrosion as a mechanism of toxic lead release into drinking water has been under scientific debate in the U.S. for over 30 years. Visual and mineralogical analysis of 28 lead pipe joints, excavated after 60+ years by 8 U.S water utilities, provided the first direct view of galvanic corrosion presence/extent in practice. Three patterns were observed: (1) no galvanic corrosion; (2) galvanic corrosion with lead pipe cathodic relative to anodic copper/brass; (3) galvanic corrosion with lead pipe anodic relative to cathodic copper/brass. Pattern 3 is consistent with the order of increasing nobility found in empirical galvanic series (lead, brass, copper). Pattern 2 is consistent with galvanic battery reversion, possibly depending on certain water quality and/or flow conditions. A variety of copper-sulfate minerals (Pattern 2), and lead-sulfate and lead -chloride minerals (Pattern 3) were identified to form in the galvanic zones, with geochemical modeling confirming the required pH drop from the bulk water level to pH 3.0-4.0 (Pattern 2) and pH<5.5 (Pattern 3), as well as the migration of chloride and sulfate ions toward the sacrificial anode. Despite joints being over 60 years old, galvanic zones in Pattern 3 were active and possibly posed an important source of lead to drinking water. This dataset is not publicly accessible because: Overall, due to the nature of this observational research, no additional datasets would be useful to provide to the public. Most raw datasets in this research effort are not meaningful in x-y format and are not even readable by the public unless they own specialized software licenses, know how to use all of the software, and can interpret the data in its various formats as they relate to the project. The remainder of the information is photographs and tables with the raw data already included. It can be accessed through the following means: The data are generally very specific to the research topics explored, but could be shared with other researchers if requested. Interested parties who own and know how to use the specialized software involved in this research effort, may request the datasets by contacting the authors (our approved SDMP explains where all these records are located). Format: There is no single dataset and dataset format. The information is comprised of different files and electronic formats, mostly associated with specialized proprietary software that cannot be converted to x-y datasets in any meaningful way. The remainder of the information is photographs and tables with the raw data already included, so no additional raw data are needed for those. Our approved SDMP explains the data format for all figures and tables in this research effort. 

This dataset is associated with the following publication:
DeSantis, M., S. Triantafyllidou, M. Schock, and D. Lytle. Mineralogical Evidence of Galvanic Corrosion in Drinking Water Lead Pipe Joints.   ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, USA, 52(6): 3365-3374, (2018).

Tags: brass, copper, drinking-water, galvanic-corrosion, geochemical-modeling, lead, mineralogy
Organization: U.S. Environmental Protection Agency