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} <br />ENVIRONMENT,'INC. PAGE -2 ± <br />JANUARY 29, 2015 <br />•Responses to Mr. Hay's memo <br />,West Section - Section A -A - City of Thornton Reservoir <br />1. The Division attempted to duplicate the Applicant's cross section for verification, however due to <br />limitations of the Galena `software the two slurry walls with the existing City of Thornton Reservoir <br />embankment could not be duplicated 'by the Division. The Division will accept the A�palicant's . <br />slope stability analysis for the West Section due to the high factor of safety produed by the <br />Applicant (15) and the Applicants commitment to not mining within 200 feet of -th reservoir., <br />Thank you. <br />South Section - Section B -B =- 88th Ave <br />2. " The Applicant's cross-section was duplicated for verification. The safety factor pr duced by <br />Galena is significantly lower (1.19) than the safety factor produced by the Applica t`s model (13). <br />= Therefore, this slope configuration is unacceptable for the South Section cross -s ction: <br />I asked °Dee're,and Ault.to- revise their analysis to calculate the factor of safety at a point <br />5 feet inside the permit /•affected lands line. - It shows that -when the propos d setbacks <br />gnd_slo a mining `method:is'used at thisJmine then the safe factor at Secti n.B =6.is 1.44 <br />t p g et , <br />and this is above the.1lfhe Division requires. - <br />- , A-copy'of the Galena model is attached. The Division will require -the Applicant to obtain structure <br />- -agreements for-411 property, including easement holders, and structure ownerswi hin two hundred. <br />g- feet of the affected land for this cross - section. Alternatively, the Applicant may revise - :the model , <br />perimeters to inc�ease`fhe factor of safety to 1-:3 or greater. <br />' We understand the limitations that are placed on the Division by,the, progra _used - - -to <br />x verify the number! the applicants, -experts +have - provided. Our-numbers are separated by <br />less then 10% -and the endpoint of the' failure radii shown on the "Divisions a" alysis are well = <br />= within the permit boundary..`This is,verif cation that if ther-ewas a slope fai•ure when the -_ - <br />setback and - sloping plan".as, proposed is being -used; there will, be- no effect`on -any struc= <br />Lures off the .mine' permit urea. ,The.Applicants.reyised -model is attached. <br />-3. The "Deere &Ault stab'ility;analysis model reversed the cross - section positions of o erbiarden and <br />:. sand & �graveiand labeled the slurry wall as "Sand &Gravel ". Please review the alysis model <br />arid.re! viseahe _model as`needetl. <br />' - The legends on the figures have been corrected and cppies.attached for the file:- This did <br />not have any of -feet on the results of- the, analysis. <br />�� East-Section -- Section D -D Monaco Street <br />4. The Applicant's cross section was duplicated ,for ,verification. The safety factor pro ucedby <br />Galena: is significantly lower`,(1.19) than the safety factor "produced4 the,Applicant�s4model {1:3). <br />hr, Therefore, this,slope confguratioiY is "-unacceptable for the'East Section cross -sec io i:_A +copy'of <br />the Galana yodel is attached The Division will require ttie,Applicant:to obtain stre cttire agree= <br />ments.fo'r all property, including easeriient holders, and structure_ owners `within `hundredifeet <br />