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s Individual dlsch;raer Tr:,--,t mo,:idual is benefitUnq at the evriense of all e>,isting and I otential use, ; of the affected water resource, and he/she is not entitled to the same Status or considerations, described above, for a water supplier who has total control of, the water within its distribution system. Under the law, a discharger of waste does not have permission, absent waste discharge requirements, to add chemicals to a body of water that he/she does not own or totally control, especially when such chemicals provide no benefit to the water resource nor to the subsequent users of that water. The chloroform was not placed in the ground water in the process of eliminating pathogens and does not belong in ground water for any other reason. The users of the water resource derive no benefit from the existence of the chloroform in the water nor from the process which caused the contaminant to enter the water. Additionally, if a discharger is permitted to place THMs in the water supply up to the TTHM standard and if that rave water must be disinfected prior to use as domestic supply, the chlorination process could cause the TTHM concentration at the tap to exceed the TTHM standard. Because the contaminant entered the water resource as the result of improper waste discharge to land, the requirements of Article 5 of Subchapter 15 may be applied. 52558, Corrective Action Program, requires that a discharger who has caused degradation of surface or ground water must engage in a remedial action program to restore the quality of the water resource to the "water quality protection standards". Water quality protection standards are defined in 52552(b) as "background concentrations ... before wastes are discharged". There are other instances where water quality criteria more stringent than MCLs are applied to protect the beneficial uses of a water resource. It is common practice to require compliance with aquatic life criteria for heavy metal contaminants in surface waters that are often lower than MCLS for the same contaminants. In summary, the appropriate water quality goal for application to the protection of an ambient source of domestic supply from chloroform is the 10-6 cancer risk level. This is consistent with the use of such criteria for other VOCs, like TCE. The use of the TTHM MCL in contaminated site cleanups does not protect the beneficial use of the water resource. The TTHM MCL should only be applied to drinking water as it is delivered to the consumer afte,rdisfnfectfon. MCLs in general are not designed to protect ambient water quality and are not necessarily intended for use as goals of cleanup efforts. The precedent for applying criteria more stringent than h1CLs to protect