25E - AGMT - ON-CALL ENGINEERING SRVS

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initial well redevelopment by swabbing end airlifting Is an extremely Important component of the well redevelopment process. GEOSCIENCE anticipates that at least 60 hours of redevelopment by swabbing and oiriifttng will be necessaryto property remove and neutralize tha.chemicals Introduced In Task 6.5, and to redevelop the filter pack and near well zone, GEOSCIENCE will provide part-time Inspection during the airlift development process and will closely monitor discharge water turbidity and send content to track the development progress of the well. Qi ,OSGIENcE will carefuily'foflow sand concentrations within the discharge throughout the process and will provide direction to the Contractor should particular areas of the screen require additional work to reduce the sant) to a minimum. e. Final Redevelopment by Pumping and Surging Final redevolopinent by pumpingend surging Es a particularly important Part of the redevelopment process and requires ciose.monitoring of water level and discharge data as well assand content. GEOSCIENCE Will monitor final development on a parttime' basis, Tests for sand content and specifo capacity will be performed frequently tomeasure the advancement of the development process and to ensure thatthe well isfully developed before beginning the aquifer pumping tests. GEOSCIENCE antieipates that a minimum of 40 hours will. be necessary forthorough redevelopment f. Step Drawdowh and Constant Rate Pumping, Tests once final redevelopment is determined to be complete, pumping tests will be performed on the well to determine any changes to well and aquifer characteristics and to document sand readings over time from start of pumping. Recovery measurements should be collected for a minimum of four (4) hours followingthe constant rate pumpingtest. The recommended aquifer pumping tests are as follows: • Step Drawdown Pumpinglasts-to determine specific capacity and well effiolenoy relationships, Typically three to four rates are selected for pumping, beginning at the lowest rate and working up to the highest, • Constant Rate Pumping Test & Recovery Test -time drawdown and recovery measurements will be made to determine aquifer parameters such as transmissivity and storatNity. it is recommended that the constant rate test be conducted for 24 hours with 4 hours of recovery measurements, GEOSCIENCE will provide full-time inspection during the step drawdown test and part-timer inspection during the 24-hour constant rate and recovery test. g post -Redevelopment Downhole Video Survey and Well Disinfection Itis recommended that a dualscan downhole video survey be conducted within the well following, redevelopment and testing to sarve as a record of the post -redevelopment condition of the well casing and screen. GEOSCIENGE will provide full -lime inspection during the video survey. The well should be disinfected aaseon as redevelopment and aquifer pumping tests leave been performed. A strong chlorine solution should be added to the well following removal of there Pump to obtain. a required minimum concentration of 200 mtlligrafns per fiter(mg/L) free chlorine concentration. GEOSGIENCE will provide full tune inspection of well disinfection to ensure that the proper coneentratioris of chlorine are used ardthat the chlorine is proparlyEnjeoted and dispersed within the well. S. Prepare summary letter report At the conclusion of rehabiPtation.actlyides, GEOSCIENCE will prepare a letter report in 100% FINAL format that summarizes the details of the redevelopment and testing process. The report will, at a minimum, include the following: • Pre-radevoloPment. well condition, • Chronology of activities, • Description of methods used during well redevelopment, Well redevelopment results and post -redevelopment well Condition, . Analysis and results of aquifer pumping tests, end • Other pertinent data, analytical results, recommendations and conclusions. Water and Sewer Pipeline Design TASK 1- PROJECT ADMINISTRATION Poor to the start of the project, we will have a kick-off meeting with City Staff and the project team to review the project objeotives, schedule, the scope and approach. At this meeting, We will establish a point of contact for the project and request all available Information related to the project, in addition, the NV5 Project.Manager will coordinate all aspects of the project and manage the schedule and costs to ensure the project's completion to the satisfaction of the City. TASK 2 - RESEARCH EXISTING CONDITIONS Q ltf 25E-512