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COLORADO LEGACY LAND
<br /> On the slide titled"Surface Runoff',the operator states Ralston Creek flows vary from 2.1 cfs(baseflow)to The flow range has been updated(<1 to 80 CFS)with flow data collected by CLL and reported to DRMS and project stakeholders
<br /> 32.4 cfs(May)just upstream of Ralston Reservoir".Please revise this information to reflect recent data,if in the quarterly sampling memos.
<br /> 28f needed.This slide also states"Some uncertainty as to whether RC is gaining or losing in the mine area".
<br /> Please clarify whether this information is still unknown. Has the operator collected any additional data Due to the dewatered nature of the mine pool,sumps,and by-pass pipeline it is not possible for CLL to assess if Ralston Creek is a
<br /> since 2018 that might shed some light on this matter?If so,please update this slide accordingly. naturally gaining or losing creek within the permit boundary.These engineering controls have been in place since before 2018,
<br /> when CLL took ownership of the site.
<br /> On the slide titled"Water Treatment Plant",please update this slide to reflect current conditions with only Slide 21 of the Ensero CSM PowerPoint discuss sumps and reflects the current conditions with one master sump in operations.
<br /> 28g one sump in operation.Additionally,please describe how the brine is"amended"prior to being injected
<br /> into the deep mine workings. Slide 16 has been revised to state that the brine is amended with barium chloride prior to being injected back into the mine.
<br /> On the slide titled"Reverse Osmosis and Brine Injection",please provide an estimated volume of brine Brine production is typically-30%;clean discharge water is-70%of the total volume of water removed from the mine. This
<br /> generated from the WTP on an annual basis.Additionally,this slide refers to"density stratification"in the slide has been updated to include the estimated annual volumes of each. The text on this slide 17 has been revise to state,"The
<br /> 28h mine pool,while in Appendix 2-Tracer Test,the operator describes the mine pool as being"sufficiently brine remains isolated in the deep workings because of inward hydraulic gradients."
<br /> mixed". Please explain this contradictory language.When referring to the mine pool as mixed,is the
<br /> operator referring to only the upper portion of the minepool?
<br /> Slide titled"Clean Water Management"includes"Conditioning and/or polishing before discharge".Please Water from the RO is at times routed through the IX vessels prior to discharge for conditioning/polishing prior to discharging.
<br /> 28i describe the type(s) of conditioning and/or polishing that is done prior to discharge.Additionally,please While it is not necessary,it provides redundancy to the uranium removal performed by the RO process.
<br /> explain what e s of"beneficial use"for the WTP discharge are being contemplated.
<br /> Please update the first slide titled"Water Capture and Diversion"to reflect that only one sump remains on Revised as requested-this information is presented on slide 21,titled"Sumps". The groundwater monitoring network shall be
<br /> 28j site.Does the operator have any plans to install additional sumps in the valley once the excavation project used for monitoring once the sumps are removed.Once all the source areas are removed,continued use of sumps to collect
<br /> concludes and clean fill has been placed,in order to monitor any potential impacts to the alluvial groundwater is not necessary since the alluvium has been largely removed and bedrock groundwater is being captured by the
<br /> groundwater system from site facilities e. .,waste rock piles,mine pool,water treatment plant)? mine.
<br /> 28k Please update the third slide titled"Water Capture and Diversion"to reflect that only one sump remains on Revised as requested-this information is presented on slide 21,titled"Sumps".
<br /> site.
<br /> Please update the slide titled"Alluvial Groundwater Flow"to reflect that alluvial water is currently only Slide 21 (titled: Sumps) describes the sump installation and operation at the site. After precipitation events,the sumps do not
<br /> being intercepted by one sump.Please describe how the operation is managing stormwater/runoff that collect or hold water,the water is pumped back up to the WTP and then routed underground for disposal. CLL does maintain a
<br /> 281 comes into contact with any exposed contaminated alluvial soils temporarily stockpiled on site during the "trash pump"at the site that has been used to pump water collected from excavation pits back up to the WTP where it is disposed
<br /> valley excavation project.Is any water retained in the valley for more than 72 hours pumped to the water of back in the mine.
<br /> treatment plant for treatment prior to discharge?
<br /> The first slide titled"Bedrock Groundwater Flow"includes"...potential connections to RC via This slide summarizes the results of previous studies and data are presented in the Section 8 Groundwater of the EPP(Technical
<br /> 28m joints/fractures"and"Illinois Fault System".Has the operator performed any studies to better characterize Revision 23,Attachment B Schwartzwalder Mine Environmental Protection Plan [Whetstone Associates Inc.,2016]).
<br /> the hydrogeology in the area,particularly with regard to bedrock groundwater flow through
<br /> joints fractures,pegmatites and/or major faults stems that intersect the mine workings
<br /> The second slide titled"Bedrock Groundwater Flow"includes"Historical observed uranium concentrations Slide 26 and 27,titled"Bedrock Groundwater Flow"has been revised for clarity and consistency with the EPP(Technical
<br /> suggest a hydraulic connection from the mine pool to Ralston Creek"and"Timing suggests flow from the Revision 23,Attachment B Schwartzwalder Mine Environmental Protection Plan [Whetstone Associates Inc.,2016]).
<br /> mine pool to RC correlates to increases in mine pool elevation".These statements appear to contradict the
<br /> 28n Environmental Protection Plan(EPP;last revised in2017 through TR-23 approval),which states"Ralston
<br /> Creek does not appear to be in strong hydraulic connection with the Schwartzwalder Mine based on stream
<br /> flow rates,mine pumping rates,and isotopic comparison of mine water and surface water". Please provide
<br /> additional clarification on these statements.
<br /> On the first slide titled"GW Inflow to the Mine",the second figure labeled"Mine Water level During The CSM has been revised by Ensero to present data from 2018 to 2021,when CLL was the operator. Slide 16 (titled:Water
<br /> Intermittent WTP Operation"includes data for an approximate 2 month period in 2017-2018 when the Treatment Plant) has been updated to include additional operational data,which are also presented in the text of AM-06,and
<br /> mine pool was pumped down to an elevation of approximately 6,424 feet msl,then allowed to refill to an which demonstrate successful seasonal operation of the WTP.
<br /> elevation of approximately 6,447 feet msl prior to reinitiating pumping(elevation difference of
<br /> 28o approximately 23 feet).Please explain how this figure demonstrates"efficient seasonal drawdown for WTP
<br /> operation".Does the operator have any recent data collected since 2018 to support this concept?If so,
<br /> please update this information accordingly.Lastly,please describe the shortest amount of time it would
<br /> take to safely lower the mine pool from completely flooded conditions to the regulatory limit of 150 feet
<br /> below Steve Level.
<br /> The second slide titled"GW Inflow to the Mine"includes a cross section showing the mine workings,faults, This figure is from the EPP (Technical Revision 23,Attachment B Schwartzwalder Mine Environmental Protection Plan
<br /> 28p and underground water sample locations.Please explain the"underground water quality sample locations" [Whetstone Associates Inc.,2016]). The underground water quality sample locations on this figure are discussed in the EPP:
<br /> shown on this figure.When were these samples obtained,and for what purpose?Additionally,it appears
<br /> the CV Glory Hole depicted on this figure in which contaminated alluvial soils have been placed),connects " iv .3 Water Quaft Data for Seepage into the Upper Mine Levels
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