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KLE/N FELOER 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 fourth quarter 2012, the concentration of nitrate as N in the shallow groundwater monitoring well 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 MW-2 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, MW-7, MW-8 , and 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 nursery. This opinion is supported by the consistent lack of water in MW-4s and MW-4d during historical monitoring , and the consistency of the historical shallow perched groundwater gradients coming primarily from Potter Creek in the northwest corner of the nursery. 11 . In late November 1999, three deep groundwater monitoring wells were installed within the nursery property. The purpose of the wells was to evaluate groundwater quality of the first aquifer beneath the site at a depth of approximately 150 feet below grade. The reason for evaluating the deeper groundwater was to assess the potential for the nursery to be impacting the drinking water wells on the nearby Dodge and Eason properties north of the nursery. The monitoring wells have been sampled on a quarterly basis since 117226.E02/ST013R0176 Page 35 of 40 January 31 , 2013 Copyright 2013 Kleinfelder