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Review of OU-1 FS Report -2- 7 August 1992 DDRW, Tracy Other more economical methods of disposal that benefit the ground water resource should be available for the disposal of the treated ground water. Several disposal alternatives will probably need to be developed to dispose of all of the treated ground water. More investigation will be needed to adequately design a disposal system that can handle the large flows and that will maximize the benefits to the ground water resource. My specific comments on the Draft OU-1 FS Report are discussed below. MAJOR CONCERN As proposed in the Draft OU-1 FS Report, all of the treated ground water would be disposed of by reinjection into the three horizons in the Upper Tulare Formation. The Draft OU-1 FS Report addressed our concern expressed in our 5 July 1991 letter regarding an evaluation of different disposal alternatives. However, our concern regarding the use of a parallel or backup disposal alternative apparently has not been adequately addressed and reuse of the treated ground water did not appear to have been pursued as a viable disposable alternative. The preferred method of disposal of the treated ground water is either through reuse or reinjection. These methods of disposal are favored by the Board because of the inherent benefits to the resource. Disposal to land through ponding, spray irrigation, spreading basin or other means is usually favored over discharge to surface waters. Because of the high flows (930 gpm) estimated to be needed for the final ground water remedial action, multiple disposal alternatives must be considered to assure a reliable disposal system. A reevaluation of the disposal of a portion of the treated ground water by 1) reuse, such as providing treated ground water to nearby industry; 2) for irrigation; and 3) surface water discharge in a nearby irrigation supply canal , should be included in the Draft Final FS Report for OU-1. Significant investigation may be needed in order to design a disposal system that will adequately manage the flows estimated to be needed to cleanup the aquifer. In addition, regardless of whether the treated ground water is discharged to surface water or to land by either reinjection or reuse, the salt content will need to be determined. Tracy needs to collect both influent and effluent samples from the IRM when full scale operations begin again next month. Samples should be analyzed for all general minerals as a complete minerals analysis is not required for ongoing monitoring by Waste Discharge Requirements (WDRs) No. 90-275. Evaluation of Disposal Alternatives Based on the evaluation of disposal alternatives in Sections 2.4.2.5 and 2.4.3.4 and in Table 2.4-2, I have the following specific comments. 1 . Discharge to nearby industrial facilities, such as All Pure Chemical , Triple E Produce or Georgia Pacific should be considered as potential reuse alternatives for the treated ground water. Tracy needs to survey the immediate area of the base to determine if there are potential industrial users for the treated water. 2. Discharge of treated or untreated ground water to a POTW is generally discouraged. This is considered a waste of a valuable resource.