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BLACK 1508 Ridge Road <br /> FOX Nederland,CO 80466 <br /> Phone(315)414-6986 <br /> MININGwww.blackfoxmining.com <br /> L L C <br /> April 28,2022 <br /> Permits and Enforcement Section <br /> Water Quality Control Division <br /> CPDHE <br /> 4300 Cherry Creek Dr.South <br /> Denver,CO 80246-1530 <br /> Subject: Special Report Attachment <br /> Discharge Monitoring Report for March 2022 <br /> Cross Gold Mine C00032751 <br /> To whom it may concern, <br /> During the month of March 2022 there were no exceedances for the 1st half of monthly sampling at Outfall- <br /> 001.These samples were taken on 3/15/2022.All of the analytes came back with expected results that have <br /> been trending well below the discharge limits since the pilot water treatment plant began running 24/7 on <br /> 1/10/2022.The 2nd half of the monthly sampling,taken on 3/25/2022,provided extremely odd and an <br /> outliner result.This report will go into the specifics of the operations,compliance results,quality <br /> assurance/quality control methods,test results since 3/25/2022,completed/future improvements and <br /> conclusion of the findings that potentially led to the outlying results. <br /> Background/Operations <br /> Grand Island Resources,LLC(GIR)implemented a pilot water treatment system back in November 2021.This <br /> system was run periodically over the last few weeks in November and throughout December 2021.Once the <br /> system was optimized and results were taken in December,they showed promising results.Beginning in <br /> January of 2022,the system was fully automated and began running 24/7.This allowed all water onsite to be <br /> treated to within the discharge limits set by the permit. <br /> The system contains an influent submersible pump that is located in Pond 1 where both the Cross and <br /> Caribou source waters drain for treatment.This water is pumped to a filtration bank of four bag canister <br /> filters.The bag filters are run in parallel to remove any suspended particulate prior to active treatment.5- <br /> mircon filters were used based on a filtration study completed in conjunction with GIR,Graver and <br /> Environmental Site Solutions.The study showcased that 5-mircon sufficed to remove the primary shows of <br /> contamination leaving the polishing step to remove the remaining metal concentrations that remained.After <br /> the filtration process,the water is fed into a pressure vessel loaded with MetSorb media.This granular media <br /> strips the water of the metals of concern:Zinc,Cadmium and Lead. <br /> From January loth,2022,when the system began running 24/7,the operations process has been consistent. <br /> Additional improvements to documentation,training of personnel,automation,sampling program and <br /> mechanical equipment have been introduced to optimize the efficiency of water treatment at the site. <br /> PAGE 1 OF 29 <br />