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Ben Hall -3- 14 December 2006 Musco Family Olive Company Regional Water Board staff's review of the Pilot Study Report raised the following concerns'. 1. Section 3.2 of the Pilot Study Report states that "[I]evels of fats, oils, and greases (FOG) also varied in the influent batches, from less than 90 mg/1 to over 400 mg/f' and that "[t]he influent FOG levels did not appear to impair the MBR function." Regional Water Board staff's experience is that elevated oil and grease concentrations, such as those given in the Pilot Study.Report, commonly result in disruption of flow in systems much less sensitive to clogging than a 0.04-micron membrane (e.g., sewage collection systems). It appears that oil and grease separation, a technology commonly employed in the restaurant and other industries, was not considered or attempted as a means to reduce the membrane fouling described above. While oil and grease may not be the sole cause of membrane fouling, consideration should be given to (a) various means of separating oil - " and"grease from the various-waste streams and (b) potential impacts of elevated,, concentrations on individual units within the treatment train. 2. Section 6 of the Pilot Study Report states that "[o]perating a biological process is complex and requires a fairly sophisticated level of operator attention and training." Regional Water Board staff concur and are concerned that the lack of a trained operator may have unnecessarily impaired the pilot study results. 3. Appendix A to the Pilot Study Report was prepared by ZENON Environmental Inc. (ZENON) and consists of ZENON's Treatability Study of Process Wastewater for Musco ' (Treatability Study). Section 6.3 (Analytical_ Results) of the Treatability Study documented the following areas of concern: a. Reliability of.Analytical Results i. . "In addition to'variations among batches, several labs were used throughout the study and this may have further contributed to the variations." ii. "The lab(s) that were used during the first half of the study reported ZeeWeed® Permeate 80D results that were extremelyhigh,.typically in the 900,- 200 mg/L range. Most of the results in the second half of the study were reported as non'- detectable, with a few exceptions. The detection limit seemed to vary greatly with each test (ranging from <5 to <500 mg/L).". iii. "The lab results show extremely variable TSS concentrations in the ZW permeate, ranging from non-detectable to over 400 mg/L. It was suspected that these results were inaccurate due to the fact that solids were not visible in the samples before they were sent out to the lab. in addition, the wide range of effluent results is not indicative of a membrane based system (i.e. it is unlikely that there would be several hundred parts per million of TSS in the effluent one day, and non-detectable the next day, from the same filter). "it is also possible that the tests"were not performed on the samples in a timely manner, allowing biogrowth or post-precipitation to occur.. However, it is