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Ms. Patricia Nelson <br />' Due• sL:~o3 <br /> Page Two <br />' Exceedance of appliable permit effluent limitations resulted from: <br />' Pf Dixharge from snowmelt runoff occurring within 48 hours after runoff inflows <br />to [he <br />ond(s) have sto <br />ed <br /> pp <br />p <br />' O Dixharge from rainfall runoff occurring within 48 hours after measunble <br />reci <br />itation hu sto <br />ed <br /> p <br />pp <br />p <br /> Documentation of predpitation and snowmelt occurrence and snowmelt inflows to the ponds <br />' is retained at the minesite and is available for inspection by authoriud agency representatives. <br /> Copies of relevant temperature/precipi[ation data are attached for reference. <br />' All sedimentation ponds are designed to contain the full design runoff volume resulting from <br /> a 10 year, 24 hour storm event. Stormwater storage apacity is in addition to design sediment <br /> storage and any permanen[ storage apaaty. Kerr inspects all sedimentation ponds on a <br />' quarterly buffs. Inspections include evaluation of accumulated sediment levels relative to design <br /> sediment storage capacity to verify that design Stormwater storage apacity is maintained at all <br /> times. If inspections indiate that sediment accumulations ue at or near the design sediment <br /> level, Kerr removes accumulated sediment from the pond(s) a•i[hin a reuonable period (typically <br /> 30 to 60 days) following the inspection. Both pond inspection reports and documentation of <br /> pond cleanout are retained at [he minesite and are available for inspection by authoriud agenry <br />' representatives. Baxd on direct observation of pond storage levels at the time dixharge <br /> occurred, the dixharge resulted from: <br />' !i~ Rainfall or snowmelt runoff volumes less than or equal to the design 10 yeu, 24 <br /> hour storage volume <br /> D Rainfall or snowmelt runoff volumes greater than the design 10 year, 24 hour <br />' storage volume <br /> Based on [he preceding information, Kerr respectfully requests that the Water Quality Control <br />' Division approve a Stormwater exemption for exceedance of effluent limitations consistent with <br /> exemption and usociated burden of proof provisions u outlined in Permit COG850021. It is <br />' understood that this exemption applies orsly to the specified moni[oring period(s), the subject <br />win <br />effluent <br />arameters: <br />and th <br />f <br />ll <br />f <br />ll( <br />) <br /> g <br />p <br />a <br />s <br />, <br />e <br />o <br />o <br />ou[ <br /> l~ TSS <br />' <br /> O Settleable Solids <br />' ~ Other /ate <br /> <br /> <br />1 <br />