Laserfiche WebLink
' CMC—Henderson Operations <br /> 5-Quarter Water Quality Data and Baseline Parameters Report <br /> May 2014 <br /> ' 3.3.2 Baseline Parameters Data Assessment <br /> MLGW-17 monitoring data is summarized in Table C — MLGW-17 Monitoring Data. All results were <br /> observed to be below the agricultural standards specified in Table 3 (refer to Appendix B) of the CBSG <br /> with the exception of pH. pH deviated from the CBSG Table 3 range of 6.5 — 8.5 standard units on <br /> 6/14/2013 with a measured value of 6.4 standard units. Additionally,a value of 6.6 was measured on both <br /> ' 2/26/2013 and 8/14/2013, only slightly above the 6.5 minimum. A graph summarizing pH values at <br /> MLGW-17 is presented in Figure 2. As mentioned, no other baseline monitoring parameter results <br /> ' exceeded applicable CBSG standards nor were there any other apparent trends that were a cause for <br /> concern. <br /> The baseline water quality assessment did not result in the identification of any additional parameters that <br /> warranted consideration for inclusion in the established indicator parameter list for future monitoring at <br /> ' MLGW-15. The rationale used in selecting the original set of indicator parameters summarized in Section <br /> 4.1 of the GWMP, including consideration for trace elemental cations, anionic species, oxyanions and <br /> field data, appears to continue to be an appropriate approach for this well. As such, Henderson proposes <br /> to establish long term monitoring for the seven indicator parameters listed in GWMP Table 4-1: iron, <br /> manganese,selenium,zinc,conductivity,pH and sulfate. <br /> 3.3.3 NPL Assessment <br /> Consistent with Section 5.1 of the GWMP, Henderson proposes that NPLs for MLGW-17 be established <br /> ' using the agricultural use standards specified in CBSG Table 3 (refer to Appendix B) for dissolved iron, <br /> dissolved selenium and dissolved zinc. Data for conductivity and sulfate will be "report" only, as NPLs <br /> are not applicable for these parameters. The NPL range for pH was developed using ambient data as <br /> discussed in Section 3.4 below. The NPL for dissolved manganese was developed in accordance with <br /> ' Establishing Background Threshold Values (BTV)for Manganese (Gateway Enterprises, 2012), included <br /> as Appendix H to the GWMP.Proposed NPLs for MLGW-17 are summarized in Table 3-3 below. <br /> Page 6 of 9 <br />