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Kimley»>Horn Page 2 extraction of the pump did not cause new or further damage to the well casing. JLA compared observations from the 2016 well video with a 2009 well video performed by Aquifer Maintenance and Performance Systems, Inc. (AMPS). The majority of observations made during the recent 2016 video were also present in the 2009 video, but the amount of scaling and growth was more substantial in the recent 2016 video. A comparison of observations made during both the 2016 and 2009 well videos is provided in the attached JLA Memorandum dated December 9, 2016. Due to existing concerns over the S4 casing damage, a review of the 2002 and 2005 CDM IRCU South Wellfield Rehabilitation Phase I &II Reports outlining how the well S4 casing was originally damaged, was conducted. Key differences and similarities between the Phase I & II Reports include to following: • As described in the Phase I Report (2002) the well S4 pump and column pipe (45 feet length) had become lodged in the well and required the use of a vibratory hammer and 100 ton crane for removal. The PVC well casing was separated at 26 feet below pad level (BPL) and was raised up approximately 3-4 inches above the concrete pump pedestal as a result of this effort. • As described in the Phase II Report (2005), repairs were made to the S4 wellhead but not to the cracked well casing. At the time, the cracked well casing was not considered a sanitary hazard because the larger outer 24 inch diameter steel surface casing was assumed to provide a sanitary seal between shallow groundwater and the well production interval. From the current 2016 video, there is clearly infiltration of groundwater into the well casing. • Phase II Report (2005) refers to a plumbness and alignment test (P&A) being performed to determine if the new pump would pass freely to the new pump setting depth of 100 feet BPL. The P&A test descriptions stated there were two locations where the well was not properly aligned and that the pump column pipe became lodged, but "not too tightly" during installation. (Refer to attached 2004 plumbness and alignment test exhibit) SUMMARY AND RECOMMENDATIONS Based on the work completed to date, the following conclusions are provided: • Historically, well pump assemblies have been difficult to extract from well S4 due to an out of plumb PVC well casing. kimley-horn.com 1920 Wekiva Way. Suite 200, West Palm Beach, FL 33411 561 845 0665 P102