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0 For downstream Site HGSD3, no standards were exceeded. <br />Review of the TDS regression plots indicates that NPDESIH exhibits a <br />decreasing TDS trend. There is not enough TDS data for NPDES2H to <br />indicate a trend. Upstream Site HGSD1 displays a recently decreasing TDS <br />trend. Likewise, downstream Site HGSD3 indicates a recently decreasing <br />TDS trend. <br />Ground Water <br />Ground water quality reports for this year are presented in Appendix B. <br />Data provided includes a water quality report for this year, sampling <br />remarks and a listing of a regression plot of historic TDS data. A <br />review of the TDS regression plots indicates decreasing trends at both <br />wells. <br />This year's ground water quality was compared against CDPHE ground water <br />agricultural use standards (CDPHE, Reg. 41, 2008). Results of those <br />comparisons are presented in Table 4. This table indicates that the <br />downstream Well HGDAL3 exceeded the boron standard (750 ug/1) in <br />September with a value of 900 ug/1. Both wells exceeded the manganese <br />standard (0.2 mg/1) in both May and September. <br />According to the CDPHE, the 750 ug/l boron standard is set for sensitive <br />crops (CDPHE, Reg. 41, 2008), and that the limit otherwise is 5000 ug/l. <br />None of these sensitive plant species are grown commercially in this <br />area. <br />It should also be noted that, while the CDPHE uses a manganese standard <br />of 0.2 mg/l, the EPA states that this standard is used to protect crops <br />grown in soils with a pH value lower than 6.0. In January 2008, CDPHE <br />revised their ground water agricultural standard to reflect this pH <br />qualifier. In soils with a higher pH (as are found in the HGT region), a <br />more appropriate standard would be 10 mg/l (EPA. 1976. "Quality Criteria <br />for Water"). This year, neither of the Loadout wells displayed a <br />manganese value higher than 5.27 mg/l. <br />3