铅和铜规则（LCR）要求公用事业公司保持最佳腐蚀控制，以防止铅和铜溶解到饮用水中，同时不影响其他与健康相关的水质目标。随着具有竞争性水质目标的新法规生效，维持最佳腐蚀控制处理（CCT）变得越来越困难。随着公用事业公司实施变革以实现这些新目标，它们越来越有可能危及对现有要求和水质目标的遵守，尤其是在CCT和LCR合规方面。当改变水源、处理或分配操作以满足新的水质目标时，重要的是评估对腐蚀的潜在影响，并在必要时重新优化CCT。最直接影响铅和铜腐蚀的水质因素是pH值、碱度和正磷酸盐浓度（使用缓蚀剂时）。 影响这些参数的变化最有可能影响铅和铜的溶解度，需要重新优化CCT。然而，还有其他参数（例如，总溶解固体、氯化物与硫酸盐的质量比和二次消毒剂）也会影响铅和铜的腐蚀。因此，评估任何变化的潜在腐蚀影响并在必要时重新建立最佳CCT始终是一种良好的做法。在实施变更之前，公用事业公司可能不可避免地会采取所有必要的预防措施，但仍会经历负面的意外后果。在这种情况下，可以使用历史数据审查、扩大基线监测和其他工具来帮助确定意外后果的原因。增加监测或使用其他工具（如收集的管道回路研究）来监测变更对CCT有效性的影响也是一种良好做法。在实施任何变更之前，应联系州或首要机构，以确认与腐蚀控制相关的公用设施要求，并防止项目延误。 包括25个参考文献、表格和图表。

The Lead and Copper Rule (LCR) requires utilities to maintain optimal corrosion control to prevent the dissolution of lead and copper into drinking water without compromising other health-related water quality goals. Maintaining optimal corrosion control treatment (CCT) has become increasingly difficult as new regulations with competing water quality objectives become effective. As utilities implement changes to meet these new objectives, they are increasingly at risk of jeopardizing compliance with existing requirements and water quality goals, particularly in the areas of CCT and LCR compliance. When making a change in source, treatment, or distribution operations to meet a new water quality objective, it is important to assess the potential impact on corrosion and, when necessary, re-optimize CCT. The water quality factors that most directly impact lead and copper corrosion are pH, alkalinity, and orthophosphate concentration (when a corrosion inhibitor is used). Changes that impact these parameters are most likely to impact lead and copper solubility, and require re-optimization of CCT. However, there are other parameters (e.g., total dissolved solids, chloride-to-sulfate mass ratio, and secondary disinfectant) that can also impact lead and copper corrosion. As such, it is always good practice to assess the potential corrosion impacts of any change and re-establish optimal CCT, if necessary. It is perhaps inevitable that utilities will take all of the necessary precautions prior to implementing a change and still experience negative unintended consequences. In such cases, a review of historical data, expanded baseline monitoring, and other tools are available to help identify the cause of the unintended consequence. It is also good practice to increase monitoring or use other tools, such as harvested pipe loop studies, to monitor the impacts of a change on CCT effectiveness. The State or primacy agency should be contacted prior to implementing any change to confirm utility requirements related to corrosion control and prevent project delays. Includes 25 references, tables, figures.