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diagram plots of well water chemistry will also be evaluated to identify water quality <br />changes or degradation trends. <br />Spring Flows and Quality. Spring flows and quality changes at spring monitoring sites <br />will be compared to ranges developed from multiple-year baseline monitoring data. <br />Significant flow or quality deviations from the multiple-year ranges not explainable by <br />climatic fluctuations will be considered to suggest impacts from mining. <br />Surface Water Monitoring Plan <br />Introduction. Determinations of the probable hydrologic consequences (PHC) of mining have <br />been made by including detailed analyses of historical surface water quality data (see Tab <br />17, Probable Hydrologic Consequences). Table 1N-1 presents the surface water sites used <br />to substantiate the significance findings presented in the PHC analysis and for measuring <br />potential future mining impacts. The following section summarizes how future mining <br />impacts on both surface water quality and quantity will be evaluated using monitoring data <br />collected at surface water sites at Seneca 11-W. <br />Surface V7a ter Quality. The significance of surface water quality impacts will be <br />evaluated by analyzing for prominent trends of changing chemical concentrations over time. <br />Consistently increasing concentrations of chemical parameters will be considered to <br />suggest mining impacts. Data collected at sites located above mining (i .e., FG2, SG7, <br />FG3, and FGS, see Tab 15, Hydrologic Monitoring Program) will be used for investigating <br />whether any future observed trends at downgradient surface water monitors are natural or <br />result from mining. <br />Surface Water Quantity. Trending analysis, as mentioned in the previous section, will be <br />used to evaluate mining impacts on surface rva ter quantity. Consistent increases or <br />decreases in flow over time at surface water rnonito ring sites will both suggest mining <br />impacts. Should trending analysis of flow data suggest negative impacts from mining <br />(decreasing flow trends), Peabody will consider more frequent flow monitoring and further <br />investigation to define whether trends reflect natural or non-mini ng causes (irrigation) <br />as opposed to mining impacts. <br /> <br />6 <br />