Water Supply (Dec 2023)
Harvested versus conditioned new test pieces in drinking water lead or copper corrosion testing
Abstract
Corrosion monitoring apparatuses are important tools in drinking water distribution systems for empirically assessing effectiveness of corrosion treatment before application to the entire water system. They are also important for tracking lead or copper release in the distribution system before, during, and after a treatment strategy is in place. A major debate is whether to use test pieces of pipe harvested from the distribution system or to use conditioned new metal surfaces. Harvested and conditioned new test pieces were studied in multiple types of water systems using analysis of chemical scales, biofilms, and metals release data. It was found that both methods of testing are equally valid if procedures follow certain conditions: (1) apparatus configuration and operation are consistent, (2) properties of distribution system pipe wall accumulations are known, (3) dissolved and particulate metal fractions are determined, and (4) apparatus metal release data are correlated with residential data. The use of conditioned new test pieces, obtainable with relative ease, lowers corrosion control study costs, providing a tool for water systems of all sizes to select the most effective corrosion control strategy and to pro-actively track lead and copper release trends in the distribution system. HIGHLIGHTS This research demonstrates that data from conditioned new metal test pieces and harvested metal test pieces are equally representative of actual lead and copper release in a drinking water distribution system and equally valid when considering and choosing chemical treatments.; With either harvested test pieces or conditioned new test pieces, the testing or monitoring program should (1) maintain consistency of apparatus configuration and operation, (2) determine the properties of distribution system pipe wall accumulations, (3) identify metal fractions of the total metal concentration, and (4) place apparatus data in context with residential sampling.;
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