2018-05-11_REVISION - M1977493 (2)

Home Browse Search

Water Quality Monitoring Plan Climax Molybdenum Company Version. R4 Permit No. M-1977-493 4.0 MONITORING PARAMETERS AND MONITORING SCHEDULE The monitoring program provides data to demonstrate that EPP requirements are being met as well as to detect potential changes in water quality that may be related to mining and milling operations at the site. This Section describes the monitoring parameters and frequency of monitoring. Sections 5 and 6 describe the evaluation processes for compliance with Numeric Protection Levels (NPLs) and for determining when changes may be occurring so that appropriate actions can be taken. 4.1 Monitoring Parameters The list of monitoring parameters was originally developed in TR-18, in consultation with DRMS, based on a review of available baseline data from the existing monitoring network, monitoring data from other collected mine water sources throughout the site, general process knowledge, an evaluation of the monitoring requirements under Climax's existing CDPS permit, and a review of the applicable groundwater quality standards in the Interim Narrative Standard (CBSG Section 41.5(C)(6)(b)(i)). TR-18 set forth a baseline monitoring list that corresponded to those parameters that could potentially be adversely affected by Climax Operations. TR-18 also set forth shorter indicator parameter lists for groundwater and surface water monitoring locations proposed for use in demonstrating compliance with applicable groundwater standards. The analytes on the indicator parameter lists were also monitored throughout the full baseline monitoring period. Monitoring data using the expanded baseline parameter list were collected over a period of time necessary to provide the minimum of 5 successive quarterly samples required by TR-18. However, as described in TR-24, monitoring under the expanded baseline parameter list continued with analyses being performed through 2017. These data provide a baseline monitoring data set for use in comparing data collected in subsequent years. The full baseline data set through 2017 was reviewed to determine if parameters should be added or removed from the indicator parameter lists for continued routine monitoring and establishment of NPLs. This review of baseline monitoring data has validated the selection of indicator parameters, that 1) are associated with mining related sources; and 2) have a reasonable potential to exceed groundwater quality standards. The following sections of this WQMP describe the evaluation of the baseline data and sets forth the indicator parameters used to establish NPLs and the expanded baseline parameter list for continued monitoring and reporting. 4.1.1 Groundwater Monitoring All of the identified groundwater monitoring sites have been subject to the same monitoring program during the baseline monitoring period established in TR-18. The analytical parameter list for baseline monitoring in TR-18 included the EPA metals Target Analyte List(TAL) for dissolved metals, plus the addition of total and WAD cyanide, fluoride, chloride, sulfate (SO4), bicarbonate (HCO3), Nitrate (NO3) + Nitrite (NO2), total organic carbon, hardness, and total alkalinity. This analytical parameter list for groundwater monitoring is presented below as Table 4-1. Climax also developed an initial indicator parameter list in TR-18 for long- term, post baseline, monitoring and establishment of NPLs. Analytes included in the original indicator parameter list for long-term groundwater monitoring are also presented below in Table 4-1. EPP—Appendix C May 2018 12