拟议的消毒剂/消毒副产品（D/DBP）规则要求通过强化混凝去除20%至50%的总有机碳（TOC），具体取决于水源水的TOC和碱度。此外，TTHM和HAA5的建议最大污染物水平（MCL）分别为80和60 ug/L，必须在规则的第一阶段得到满足。在D/DBP规则的第2阶段，TTHM和HAA5的建议MCL分别为40和30 ug/L。对于许多公用事业公司来说，单靠强化混凝可能无法实现这些建议的MCL。为了获得关于颗粒活性炭（GAC）和膜对各种水的可处理性的信息，信息收集要求（ICR）规则将要求许多公用事业公司使用GAC或膜进行台架或中试规模的处理研究。进行强化混凝和GAC处理研究所需的公用事业公司可能有兴趣在强化混凝后检查GAC的性能。 通过强化混凝进行预处理可以显著提高GAC去除天然有机物（NOM）和DBP前体的性能，因为吸附器上的TOC负荷较低，因为NOM混合物的吸附容量随着TOC的降低而增加。因此，在GAC吸附能力耗尽之前，可以处理更多的水。此外，由于NOM在较低的pH值下不易溶解，因此具有更好的吸附性，如果通过吸附器维持强化混凝所需的较低pH水平，GAC的性能可能会得到改善。活化循环之间GAC床寿命延长所带来的成本节约可能会抵消在高混凝剂剂量和较低pH值下运行所带来的化学成本和材料成本增加。成本分析的结果已经给出。

The proposed Disinfectants/Disinfection Byproducts (D/DBP) Rule requires 20 to 50% removal of total organic carbon (TOC) by enhanced coagulation, depending on source water TOC and alkalinity. In addition, the proposed maximum contaminant levels (MCLs) of 80 and 60 ug/L for TTHM and HAA5, respectively, must be met in Stage 1 of the rule. In Stage 2 of the D/DBP Rule, the proposed MCLs for TTHM and HAA5 are 40 and 30 ug/L, respectively. For many utilities, enhanced coagulation alone may not achieve these proposed MCLs. To obtain information on the treatability of a wide range of waters by granular activated carbon (GAC) and membranes, the Information Collection Requirement (ICR) Rule will require many utilities to perform bench or pilot-scale treatment studies with GAC or membranes. Utilities required to perform both enhanced coagulation and GAC treatment studies may be interested in examining GAC performance following enhanced coagulation. Pretreatment by enhanced coagulation may significantly improve the performance of the GAC for the removal of natural organic matter (NOM) and DBP precursors due to lower TOC loading on the adsorber, since the adsorption capacity of an NOM mixture increases with decreasing TOC. Thus, more water can be treated before GAC adsorption capacity is exhausted. Furthermore, since NOM is less soluble at lower pH values and therefore better adsorbed, GAC performance may be improved if the lower pH levels required for enhanced coagulation are maintained through the adsorber. The cost savings due to increased bed life of the GAC between activation cycles may offset the increased chemical costs and material costs due to operation at high coagulant doses and at lower pH. The results of a cost analysis have been presented.