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Kimley»>Horn December 31, 2016 Arjuna Weragoda, P.E. Capital Projects Manager IRC Department of Utility Services 1801 27th Street Building A Vero Beach, FL 32960 RE: Indian River County Utilities Department South County WTP Floridan Well Rehabilitation Project Production Well S-4 Condition Assessment Contract #2016031 Dear Mr Weragoda, There follows a summary of our findings and observations of the condition of the South Oslo Road production well S-4, and the recommendations to restore and/or replace the well to full service conditions. Well S-4 was intended to be rehabilitated, along with three other wells under contract IRC -2016031, currently being performed by All Webbs Enterprises (AWE), Inc. Well S-4 was selected first to be rehabilitated because of its low capacity and apparent elevated turbidity. Silt Density Indices (SDI) were also elevated and the membrane plant pretreatment filters fouled rapidly when this well was placed into operation with other wells, suggesting suspended material was entering the well or being produced within the well borehole. Elevated suspended material in the raw water is detrimental to membranes and can foul them irreversibly. The first step to rehabilitate the well was to take it out of service and remove the pump from the well casing. The existing pump is a vertical turbine pump with column pipe nearly 100 ft deep. The initial attempts to remove the pump were unsuccessful due to extreme resistance during lifting of the pump column pipe and apparent binding and lodging of the pump within the well casing. The contractor, AWE, then remobilized with a larger capacity 50 ton crane to dislodge the pump and column pipe. Following pump and column pipe removal AWE performed geophysical and video logging of well S4, on October 18, 2016 and October 24, 2016. During the well video, damage to the well casing was observed at depths between 7 feet and 279 feet below pad level (BPL). Casing separations identified in the well video at depths of approximately 27 feet BPL, 46 feet BPL and a casing crack at 38 feet BPL are of particular concern because their size and the scale/growth features at these depths indicate a downward migration of water in the well casing and distinct sanitary seal failure. Given the fact that this well had a history of the well casing damage due to pump extractions, further review of historical videos and reports was conducted to confirm the more recent kimley-horn.com 1920 Wekiva Way, Suite 200, West Palm Beach, FL 33411 561 845 0665 P101