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Michael Kith [EH] From: Abby Racco <abby@logelodi.com> Sent: Wednesday, March 06, 2019 4:13 PM To: Michael Kith [EH]; Linda Turkatte [EH]; Steven Shih [EH]; Dave Welch; Manjinder Jhamat Subject: Re: Revised NLS for Jhamat Michael, Dave and I were on the phone with Rodney and Steven on or about January 6, 2017, at which time they requested we stop using the evapotranspiration method as it was underestimating recharge in the Tracy area. It is true that they did not specify 75% (I apologize if we implied that in the addendum), but they did indicate after a discussion of options that a reduction of total rainfall would be acceptable. After some discussion we eventually settled on 60% (based on the average of the three sites referenced in the H&F paper) and used that value for a few reports. We later modified the value to to 75% because that value was used in Chico by H&F; the other two sites were coastal and not similar to our geology here. I do have copies of our report discussed in the Jan. 6 phone call before and after modification which support this statement. The revised report was approved by EHD. By my quick tally, we have submitted 31 reports since January 2017 which use 75% (or 60% for the first few) of rainfall. The fact that all these reports have been approved is evidence that the method was acceptable to EHD at that time. During the same time period, other consultants have used 100% of rainfall and been approved. We have tentatively scheduled a meeting with Linda at your office on Monday where we can sit down and hopefully come to some agreement about this. In the meantime, I have been updating reports that did not include our full explanation so that you and the customers would have all the information at your disposal. The completion of the Jhamat addendum was in preparation for our planned meeting. By reviewing Table 2 of the Jhamat addendum, you can see the substantial difference between the value obtained by the evapotranspiration method versus the regional recharge value (derived from ESJ Water Resources Model, hftp://www.esigroundwater.org/Portals/0/ESJWRM%20Report 1.0f) , whereas there is good correlation between the 75%value and the regional value. We feel that this provides local justification for the selection of the 75%value. You can also see on page 3 of the addendum (second to last paragraph), that it appears H&F did not use an evapotranspiration consideration to derive their recharge value for Chico, as that would have resulted in significantly less recharge. We look forward to further discussion of this topic on Monday. Abby Abby Racco Live Oak GeoEnvironmental (209) 369-0375 (209) 365-3222 cell www.logelodi.com On 3/6/19 1:26 PM, Michael Kith [EH] wrote: It is the same as what you submitted before. The 75% recharge rate is based on your personal communication with EHD staff. You told me via phone conversation that Steven gave you that 75%