SITE INFORMATION AND CORRESPONDENCE

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DER Bright�R, h.people, Right solutions, 7. Soil samples collected during the advancement of the 6 soil borings advanced in December 1997 revealed low concentrations of nitrate-nitrogen in the near-surface soil throughout the site. A soil sample with an elevated nitrate-nitrogen concentration was obtained adjacent to the north side of Basin B (B-4/MW4 location ) . However, the elevated concentration detected in the sample obtained from a depth of 5 feet had attenuated to a non- detectable concentration by a depth of 25 feet in the boring . 8. Extensive surface water flow appears to pass through the intermittent stream and other drainages on the east side of Norman's Nursery towards Potter Creek. Additionally, flow from other sources in the area enters Potter Creek. Those sources may also include the draining of the near-surface perched water. 9 . The production area of the nursery exists at an elevation ranging from approximately 118 to 148 feet above msl . According to the U. S. G . S. topographic map for the area, an intermittent stream and numerous drainages appear to flow across the Norman's Nursery site. According to the topographic survey, three main drainages enter the nursery and flow towards the drainage basin south of the office complex. 10 . Review of the nursery's water use (Chart 1A) and the level in the nursery's tail water pond (Basin B , see Chart 2) shows that while water use is consistent with that of last year's irrigation season , tailwater volumes have apparently dropped off. Additionally, according to Ms . Beverly Burdick of the nursery, production has increased . Given these three factors, it appears that the nursery's BMPs and efforts to reduce water use and tailwater have been successful . Norman's Nursery is making significant efforts beyond those required by the RWQCB to implement BMPs to further limit irrigation water and fertilizer use (when the irrigation season begins) , limit irrigation tailwater volumes and concentrations of nitrates, and limit potential impact of fertilizers in the irrigation water on surface and ground water quality. 11 . As shown in Table 8 , nitrate-nitrogen was detected in the groundwater samples from MW-2 and MW-5 at concentrations of 58. 9 mg/I and 49.7 mg/l , respectively. Well MW-2 is located at approximately the southeast corner of the nursery property. Both concentrations are in excess of the State of California Maximum Contaminant Level [MCL] for nitrate-nitrogen of 10 mg/I in drinking water as expressed in §64431 of Title 22 of the California Code of Regulations [CCR] . These results are significant for two reasons . First, because this is the third of four groundwater monitoring events that revealed nitrate-nitrogen in the monitoring well upslope (upgradient) of the nursery above the MCL. Secondly, the concentration of the nitrate-nitrogen in this upgradient well (MW-2) is significantly higher than the concentration in the downgradient well (MW-5) . 117226.E02/STO13R0176 Page 9 of 40 January 31 , 2013 _ Copyright 2013 Kleinfelder