康科德市制定并实施了一项创新的全面修复计划，以改善其配水系统的水质。目标是:讨论分阶段了解和改进铅和二次消毒问题水质分配系统的方法，即全面基线监测、数据和化学饲料评估、全面实施、持续监测和流程改进；讨论基线监测结果，描述如何评估和分析数据（DIC、缓冲强度等），以及如何识别问题；讨论用于铅控制和二次消毒控制的化学进料系统；并介绍和讨论该计划的结果和建议的未来行动计划。 建议的纠正方案是使用二氧化碳（CO2）和氢氧化钠（或烧碱，NaOH）增加溶解无机碳酸盐（DIC）。这种方法增加了DIC和缓冲强度，并稳定了整个分配系统的pH值。为了达到所需的pH值和DIC水平，对几种化学进料系统进行了评估。推荐并实施了NaOH和CO2化学进料系统。

The City of Concord developed and implemented an innovative full-scale remediation plan for improving its distribution system water quality. The objectives were: to discuss the phased approach to understanding and improving water quality distribution systems for lead and secondary disinfection problems, i.e. comprehensive baseline monitoring, data and chemical feed evaluation, full-scale implementation and on-going monitoring and process improvements; to discuss the baseline monitoring results, describe how the data was evaluated and analyzed (DIC, buffer intensity, etc.), and how the problems were identified; to discuss the chemical feed systems utilized for the lead control and secondary disinfection control; and, to present and discuss the results of the program and the recommended plan for future action. The recommended corrective program was to increase the dissolved inorganic carbonate (DIC) using carbon dioxide (CO2) and sodium hydroxide (or caustic soda, NaOH). This approach increased the DIC and buffering intensity, and stabilized pH throughout the distribution system. To achieve the desired pH and DIC levels, several chemical feed systems were evaluated. A NaOH and CO2 chemical feed system was recommended and implemented.