Fort Walton Beach Council agenda — 02-26-13--regular — reading text

LGms(ana arsnchea rwmeny Dalta Tesfin9 8 mmecmn, me and permeability rates are representative of subsurface conditions at the designated locations and or depths. It is our understanding a dry retention pond will be constructed near the northern comer ofthe proposed site. The retention pond will have an area of approximately 3700 square feet and a bottom elevation of + 15 Feet. Based upon the existing topographic information we were provided, the existing elevations within the stornrwater pond are approximately + 18 Feet; therefore, the bottom of the retention pond will be approximately 3 feet below the existing ground surface. Laboratory permeability tests were performed to estimate the permeability rates near the bottom of the proposed pond. Because permeability is not only a function of soil type but also density, the permeability tests were performed at a medium dense state. The Table below summarizes the results of laboratory permeability tests. It should also be noted the permeability rates are unfactored and should be used with an appropriate factor of safety. TABLE I: Laboratory Dry Laboratory Test Depth of USCS Density of;Soils: Permeability Location: Sample: Classification: Qbs /ft) iNhr) iL4 -1 3 ft. SP 104. 1 7. 6 TheThe permeabilitypermeability raterate statedstated aboveabove shouldshould notnot bebe consideredconsidered thethe drawdowndrawdown raterate ofof thethe pond.pond. TheThe drawdowndrawdown raterate isis aa complexcomplex 3-3- dimensionaldimensional phenomenonphenomenon dependentdependent uponupon numerous numerous factorsfactors includingincluding pond/pond/ systemsystem geometry,geometry, verticalvertical andand horizontalhorizontal infiltrationinfiltration rates,rates, groundwatergroundwater mounding,mounding, etc.etc. TheThe predictionprediction ofof thethe drawdowndrawdown raterate isis mademade moremore difficultdifficult byby varyingvarying soil/soil/ groundwatergroundwater conditions.conditions. GENERALGENERAL COMMENTS:COMMENTS: ProfessionalProfessional judgmentsjudgments onon designdesign criteriacriteria areare presentedpresented inin thisthis letter.letter. TheseThese areare basedbased partlypartly onon ourour evaluationsevaluations ofof technicaltechnical informationinformation provided,provided, partlypartly onon ourour understanding understanding ofof thethe characteristics characteristics ofof thethe projectproject beingbeing planned,planned, andand partlypartly onon ourour generalgeneral experience experience withwith subsurface subsurface conditions conditions inin thethe area.area. WeWe dodo notnot guaranteeguarantee performance performance ofof thethe projectproject inin anyany respect,respect, onlyonly thatthat ourour judgmentsjudgments meetmeet thethe standardstandard ofof carecare ofof ourour profession.profession. ThisThis information information isis exclusivelyexclusively forfor thethe useuse andand benefitbenefit ofof thethe addressee(addressee( s)s) identifiedidentified onon thethe firstfirst pagepage ofof thisthis reportreport andand isis notnot forfor thethe useuse oror benefitbenefit of,of, nornor maymay itit bebe reliedrelied uponupon byby anyany otherother personperson oror entity.entity. TheThe contentscontents ofof thisthis letterletter maymay notnot bebe quotedquoted inin wholewhole oror inin partpart oror distributeddistributed toto anyany personperson oror entityentity otherother thanthan thethe addressee(addressee( s)s) hereofhereof without,without, inin eacheach case,case, thethe advanceadvance writtenwritten consentconsent ofof thethe undersigned.undersigned. RRTRRT lQVINENMlQVINENM ERRNERRN SCIENCES,SCIENCES, INC.INC. M, leld U01S! A1pgnS yeuipaW : L6IZ) u0191nipgnS 4euipapy - Mid luewa6euepy 131" w' 01S 7uewgaelly m a N— OMOMMMOMM vYun 0' Garver, LLC Page 3 This report has been prepared in order to aid in the evaluation of this property and to assist the engineers in stormwater design. It is intended for use with regard to the specific project discussed herein, and any changes in pond locations, or assumed ( or reported) grades shall be brought to our attention immediately so that we may determine how such changes may effect our conclusions and recommendations. Our report does not address environmental issues which may be associated with the subject property. While the boring performed for this project is representative of subsurface soil conditions at their respective locations and for their respective vertical reaches, local variations of the subsurface materials are anticipated and may be encountered. The boring logs and related information are based on the driller' s logs and visual examination of selected samples in the laboratory. Delineation between soil types shown on the boring logs is approximate, and soil descriptions represent our interpretation of subsurface conditions at the designated boring location on the particular date drilled. We appreciate the opportunity to assist you. If you have any questions or if we may be of further assistance, please call at your convenience. Yours Very Truly, SOUTHERN EARTH SCIENCES, INC. Brian Walter Bloomfield, P. E. Eng. Reg. No. 65580 3 State of Florida No. 85580 BWB/ bb STATE OF ,' Enclosures Rt DV' 0 fsn SOIRNENN lN/ ITN XIENCEf, INC. d leld uoISIAIp9eS 4eulpaW L61,Z) uoISIAlpqnS 4eulpaW 4e1d lu0w96eueW lalemwiolS auew4eellV o m a d d I I I WT 2 I I I aY i I I I I I_ I I I DRAWN BY: BWB PROJECT NO. FIGURE I P13 -0014 CHECKED BY'. BWB som SCIENCES, INC. DATE: 1l22I13 TEST LOCATION mw FM MWMO u1oNSU9MM, SrncM, RaNOA SCALE: 1" = 60' PLAN  leld uolslAlP4nS 4eu! POW : L61,Z) uoISIAIPQnS 4eu' POW - ueld luou a6euelq JalemuuolS : 1uaw4ae11V d Page tof a LOG OF BORING HA -1 METHOD: Hand Auger Y u PROJECT: Madinah Subdivision DRILLER: Shane George li LOCATION: Fort Walton Beach, Florida PROJECT NO.: P13 -0014 ENGR I GEOL: Brian W. Bloomfield DATE: 01/ 11/ 13 SURFACE ELEVATION: + 18 It N Value ATTEReeRG LOCATION ( blows/ fl) uuns( xt w 20 40 SO Soil SYmbols Atterberg Llmtts sK Elevation l S ampler Symbols