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1lJN ~ <br />:14 AM MARION CTY PURCHASIKG <br />ASSUMP'J'IONS <br />FAX Na, 91503734379 P, 6 <br />The following agsumptions wetc used in thc preparation of ttus scope and cost estimate. <br />1) Soil or groundwatet wntamination will not be encountered during construction of <br />tk~e test well, observation wells, or durung t~,e pump test. It sk~ould be noteci that <br />this scopc of work does not include Qrovisions to manage or dispose o~ <br />petroleum-contaminated soil or groundwater that may be sncountered during <br />drilting or pump testi.ag. <br />2} Century West Bngineering Coiporation (CWEC) will arrange for a~1 pe~ti4s <br />associated with the disposal of ~rater p,toduced du~g the pump test. In tlus <br />regatd, we ~ave assuz~ed that a~l wate~ pu~ped ~rom the test well wiU be dis~osed <br />iu~to tk~e c~osest practical i~et to the existing storm sewet system. <br />SCO~E OF WO~ <br />Our scope of wotk is based on our diswssions with NI'ike Hayford with CWEC, project i;n£oxmation <br />provided by CWEC, and our expet~ience with s~milar projects in~ tt~e area. Ttus scope of work includes tlae <br />tasks outlined below: <br />Taak 1. Construction of Teat Well aad Two Observation Wells <br />A test .~reli and two observat~on wells wiil be co~structed near one corner of the Courthouse Square <br />block. The test well will be tottstructed by Westerberg Drilling, Inc. (Westerberg) o£ Mola~l~ dregon, <br />actit~g as a subcontractor to GRI. The observation wells will be constn,cted by Ceo-Te~h Exploratio~s of <br />1laafatin, Qregoq using holtow-stem auger drilli~g methods. Westerberg and Geo-Tech E~cpiorat~oz~s are <br />Oregon-licensed well corrtractors. A cable-tool dril~ rig will be used to co~nsttuct the test well. <br />Xnstallation of the test weil and observation weils will be ol~secti•ed a~~d docume»ted by a geo~og°ast from <br />G~tI. The test well wi11 be 8 in, it~ diameter, a~d w°iU be d~i~~ed to a depth of about 60 ft. The casing will <br />be perforated below a depth of about 20 ft using a down-hole hydraulic perForator. The observatiot~ wells <br />will consist of a 1-in. PVC slotte~ ~ipe installe~ to a depth of about 35 to 40 #}. Each well will be <br />complete~ w~it~- a Qush-mount well monument at the ground surface. We anticipate the test wef~ can be <br />incorporated into the design of th~ dewatering system. <br />Task 2. Pump Test <br />A 24-hr, constant-rate pump test will be made to evaluate tl~e pote~tial yi~ead of the test well. The test will <br />be made by Westerbearg, usittg a subt~e~tsable wel~ port~p capable of pumpusg at least 300 gpm from a deptk~ <br />of 60 ft. Flaw measvremer~ts wi1.1. be made with an in--line tnechanical flow meter. Water levels in t~e wel~ <br />will be measured and recorded during and after the test using a~ elect~c water level indicatore Watex <br />-2- <br />