6.3. SR 02-16-2010 - Laserfiche WebLink

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gage Z of 3 NSarch 1 S, 2005 The modecations included as part of the .~fSE Cerr ~ 7 Construction .Pans and S eci cations are .~ ~ as follows; ~., Cep 7 ~asegrades:.A,s approved in a letter dated January l6, 2003, Cell ~ 7 will be constructed at the same elevations as the base grades in Cell l ~, This volume addition was included in the ~R.L's current pez~nit, S~wp74, dated October g, 2003. 2, Southern erns Canstr~ctiou: The southern berm of Cell 17 has been modified such that it will now be constructed with an inbound slope ranging from 2:1 to 4.5:1 horizontal: vertical}. The initial construction, as spawn on the plan sheets ~Sheet~ 3 and ~ would be for a bean that is approximately 4.5 feet high. The initial berm. will be constructed very similar to the phase separation berms typically placed between each cell. A.s the ~Iling of Cell ~ 7 progresses, this berm wi11 be extended up in 7~5 foot vertical increments. The berm will continue to be extended until the Southern nevelapment Area is permitted ar closure grades are reached. The phased construction of this berm is detailed on the attached ~'Iguxe .. 3~ west erm~ Constructfan; The west berm is currently permitted with an outside slope to be constz~ucted at approximately ~ .5.1 ~horizontai; vertical} in an effort to preserve trees located in the setpback area, During a recent field survey it was noted that there were few trees located in close proximity to the proposed outside tae of the slope, and none of the gees ~. close proximity of the berm. were of significant size, Therefore, the ~~L ro ores to pp construct the outside slaps ofthe Cell l7 west berm at a 2;~1 slope, The 2:1 slope will be easier to construct and easier to maintain than the currrently per~uitted x..5:1 slope, This modified bens. is shown an Sheet 3 and associated details. 4. ternative Liner esign:.A,.s recently discussed an the phone, the ERL would also like the aptiaxi to substitute a layer of Geosynthetic Clay Liner (GCL fvr the upper i2-inches of . compacted clay. The technical specifications fox the GCL and installation of the GCL are included iii tae enclosed CeZI .~ 7 ~'onst~uction Plans acid Specif~ica~ions. The ~RL is requesting to keep the base of the clay linear at the carne elevation as wauld.be used ~. the currently approved 2~foot clay layer design, and therefore an additional ~ Mfoot of air space would be gained, see ~'zgure ~, C~p~~on A., Zf approval far the Option ~. base liner ~nodz~icatian is obtainable by the ~staxt of canst~ruuction, the reserve capacity already permitted is sufficient to acconuuodate this m.adi~.catian. The Option A, modi~.cation will increase the perrn~tted capacity by appraxiin.ately 6,700 cubic yards. however, as previously stated, the ~~L is anticipating the initiation. of Cell ~ 7 construction in .~pril and cannot postpone or delay this construction timepfiarne, ,~.s a result, the ~~.I, has. also sub~.i.tted an additional liner detail ~~igure ~, Option }that will maintain the currently perzni.tted base of waste elevations, and therefore substituting GCL fox the l~faot of clay; will raise the base of the clay liner by l foot, Ultimately, the decision as to whether or not GCL will be used~in place of lfoot of clay will be dependent an the costs associated with clay layer placement and GCL material and placement at the ~~L, S~ Sand. rainage layer: Lastly, as a paint of clarif~catian, the ET~.-'s permit requires a l2~ inch sand drainage layer meeting the necessary penueability requi:re:~.ents. The enclosed