2021-02-05_PERMIT FILE - M2021007

Home Browse Search

Knight Piesold CONSULTING Creek Consultants, 2014). The exceedances noted below in red do not indicate that the waste piles sampled are contributing to the impaired water quality in Clear Creek, only that there is a potential for the piles to be source materials. As the GTM Project envisions removing these piles as part of Project development, this removal would benefit the stream reach below the project area by removing a potential source of metal loading. Table 3 SPLP Results Hardness TVs TVs TVs TVs Sample ID pH CaCO3 Cadmium Cadmium Cadmium Copper Copper Copper Cd Chronic Acute Chronic Acute Units pH Units mg/L m /L m /L m /L mg/L mg/L mg/L SGLLC W-1 26.9 O.Ou!_ 0.0003 0.0005 0.100 0.004 0.127 SGLLC C-1 1 93.3 0.0030 0.0007 0.0017 0.084 0.011 OA09 SGLLC E-1 28.9 0.0028 0.0003 0.0006 025 0,004 0.136 TVs TVs TVs TVs Sample ID Lead Lead Lead Manganese Manganese Manganese Chronic Acute Chronic Acute Units mg/L mg/L mg/L mg/L mg/L mg/L SGLLC W-1 0.020 0.0006 0.015 0.599 1.065 1.928 SGLLC C-1 0.064 0.0023 0.060 1.86 1.612 2.917 SGLLC E-1 0.050 0.0006 0.016 ' 43 1.091 1.975 TVs TVs TVs TVs Sample ID Nickel Nickel Nickel Zinc Zinc Zinc Acute Chronic Acute Chronic Units mg/L mg/L mg/L mg/L mg/L mg/L SGLLC W-1 0.012 0.017 0.154 u.198 0.099 0.114 SGLLC C-1 0.025 0.049 0.442 0.331 0.290 0.329 SGLLC E-1 ', 0.018 0.164 0.322 0.107 0.121 NOTE: Red text indicates the constituent exceeds the chronic standard. Bold red text indicates the constituent exceeds both the chronic and acute standards. 4.0 DISCUSSION Based on the testing performed to characterize the materials at the GTM site, none of the materials tested can be classified as PAG in the long term due to the very low sulfide concentrations. The TCLP testing indicates the materials are also not classified as hazardous waste; therefore, they can be utilized and disposed and/or stored without special handling. Although the SPLP testing did indicate some metal leachability from the materials that exceed the Colorado WQCC instream water quality standards, these materials will be removed as part of project development; therefore, they will no longer represent a source to water quality degradation in Clear Creek. If any additional material will be handled as part of the GTM Project, it is advised that these materials also be subjected to waste characterization prior to bringing the materials to the Project area for temporary storage to confirm proper disposal practices are followed during operations. January 14,2021 DV-21-0024 5 of 6