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7.1.A. - Page 35 <br /> Groundwater -There is no groundwater withdrawal associated with the project, nor would the project <br /> affect groundwater levels. Groundwater may be present at shallow depths in certain portions of the <br /> project area. Construction activities may impact shallow groundwater at these sites by affecting flow or <br /> by introduction of possible contaminants. Excess water in excavations would be controlled using <br /> standard dewatering measures. Water quality would be screened using laboratory analyses as needed, <br /> and extracted groundwater would be disposed of appropriately. <br /> SBSA's recycled water quality specifications are based on Title 22 requirements and the RWQCB's Water <br /> Reuse Order 96-011. Numerical values for these requirements are presented in Table 2 on the following <br /> page, along with actual values from SBSA's recycled water. Although drinking water standards are not <br /> applicable to the proposed reuse of recycled water under this project, standards for select constituents <br /> have been included for comparison purposes. <br /> The purpose for including this table is that if recycled water were applied at rates that exceeded <br /> irrigation requirements, there is a slight chance that constituents in recycled water could filter into <br /> groundwater,thereby reducing its quality.There are several reasons that this is not expected to happen. <br /> First, the RWQCB requires that irrigation practices be controlled to prevent over-irrigation. With <br /> appropriate irrigation practices, there is only a moderate potential for infiltration to occur. In addition, <br /> most constituents, such as nitrate, are naturally absorbed by both plants and soils. As shown in the <br /> table,TDS levels are above potable water standards (as is typical of recycled water), but case histories of <br /> other water recycling projects have typically not shown accumulation in groundwater of salts or other <br /> recycled water constituents with long-term use. Elevated nitrate levels in groundwater are typically due <br /> to fertilizer applications; fertilizers contain more nutrients and trace elements than does typical recycled <br /> wastewater. Therefore, the potential impact of surface application of recycled water contaminating <br /> groundwater is not significant. In addition, the City does not rely on groundwater as part of its potable <br /> water supply. <br /> 21 <br />