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IRCUD Well S-4 Technical Memorandum December 9, 2016 Page 3 of 4 JLA Geosciences, Inc. Selected photographs comparing features from the 2016 and 2009 well videos are included as Attachment A. Geophysical logging performed by AWE included caliper, dual induction, gamma ray, and static and dynamic fluid conductivity and flow Togs. PDF Copies of the geophysical logs are included as Attachment B. Due to existing concerns over the S4 casing damage, JLA reviewed the 2002 and 2005 CDM IRCWUD South Wellfield Rehabilitation Phase I &II Reports which outlined how the well S4 casing was originally damaged. Key points from the Phase I & 11 Reports are summarized below: • As described in the Phase I Report (2002) the well 54 pump and column pipe (45 feet length) had become come stuck in the well and required the use of a vibratory hammer and 100 ton crane for removal. During the pump removal process the S4 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 24 inch diameter steel surface casing provided a sanitary seal between shallow groundwater and the S4 production interval. • Phase II Report (2005) also mentions a plumbness and alignment test (P&A) was performed to determine if the new pump and column pipe 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. SUMMARY AND RECOMMENDATION Based on the work completed to date, the following conclusion and recommendations are being presented for IRCWUD UFA Well S4: • Historically, well pump assemblies have been difficult to extract from well S4 due to an out of plumb PVC well casing. • Pump removal efforts to date have caused visible damage to the S4 PVC well casing at depths between 7 feet and 46 feet BPL. • Damage to the S4 well casing has been present since the pump was removed using a vibratory hammer and crane as reporting in the Phase I report (2002). • Observations from the 2009 and 2016 well videos shows growth on the S4 PVC well casing has increased. jlageosciences.com P108