SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

KLE/NFELDER BrvgMhaple.Nlght Solutlms. • This indicates that Potter Creek may, at times, be a significant source of the water in the shallow perched groundwater zone. Given the rerouting of Potter Creek to the north following Location S-4, a significant amount of water in the shallow perched groundwater zone would exist in the Barbagelata orchard to the west of Norman's Nursery and Escalon Bellota Road. 8. Groundwater gradient in the shallow perched zone in the vicinity of the northwest corner of Norman's Nursery was not able to be calculated for the monitoring period due to the lack of groundwater elevation data from the wells located in the Barbagelata orchard. Many of the previous gradients in the shallow perched zone in the northwest corner of the nursery have appeared to be towards the south, although many variations have been noted. 9. During the first and second quarter 2012, the concentration of nitrate as N in the shallow groundwater monitoring wells (MW-2 and MW-5) exceeded the California Maximum Contaminant Level (MCL) of 10 mg/I in drinking water as expressed in • Section 64431 of Title 22 of the California Code of Regulations §64431 22CCR. 10. At the request of the RWQCB, sampling was conducted of available ground and surface water monitoring locations for a detailed suite of chemical analysis. The sampling was conducted on October 3 and 4, 2000. The results of the analyses appear to indicate similar water chemistry for the surface water sample locations and the deep aquifer monitoring wells. Based on the chemistry, it appeared that the surface water samples are generally of a better water quality, similar to the deep aquifer (with the exception of the Duarte run-off), and unlike the shallow perched water. There is distinctly different water chemistry for the water samples obtained from shallow perched groundwater zone monitoring wells MW-5 and MW-7 through MW-9. The water chemistry of monitoring well MW2 is markedly different from all samples. That difference further supports the position of a lack of continuity between the shallow perched groundwater at MW-2 and MW- 5/MW7/MW-8/MW-9. Based on the chemical analysis conducted, it is Kleinfelder's opinion that the water present in wells MW-5, MW-7, MW-8, and MW-9 is from a different source than the other water samples analyzed. Also, it appears that the shallow perched groundwater zone does not originate from Basin B on the • 117226.E02/ST012R0696 Page 37 of 43 September 14, 2012 Copyright 2012 Kleinfelder