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The portion of the scope of services for Work Authorization # 15 dealing with the rehabilitation and reaming of Well No's. 1, 2, 3, and 5 has been completed. These wells were put back into service. The forced removal of the pump and column assembly of well number 4 was completed. The video survey showed that the well was not obstructed and did not require borehole reaming. From inspection of the well, it was determined that the flanged column piping had wom a depression / groove into the wall of the well casing. This depression / groove would not allow the flanged column piping to move out of the well freely. As a result of this, damage to the well occurred rendering it unusable. The damage to Well No. 4 would require attention through a Change Order to Work Authorization # 15 The current expended dollar amount for Work Authorization 15 is $312,520.00. As stated, during normal operation and testing of well numbers 6 and 3, staff discovered that the drawdown measurements for the proper water column height above the pump impellers was not being maintained. The depths of each of the pumps was 40 feet. On June 19, 2001 the Board of County Commissioners approved Work Authorization 18 with CDM in the amount of $83,500.00, for extension of the pump columns 20 feet further down into wells 6 and 3. In addition, Board approval was given to proceed with similar modifications on the other four wells (1, 2, 4, and 5), as part of this same Work Authorization. The current expended dollar amount for Work Authorization 18 is $65,500.00. ANALYSIS As a result of the depression / groove not allowing the column piping from being removed from Well No. 4, the pump, discharge head, column assembly, and well casing were damaged. This damage has rendered the current system unusable for production. As explained in the December 12, 2000 agenda item, this damage was anticipated. Staff has investigated the two options of either replacing the complete well and pump system, or repairing it. The estimated replacement cost of the well and pump system is $250,000. The estimated repair cost for the system is $145,440. (See attached draft CDM cost estimate). The less expensive repair option entails making repairs to the damaged well casing, replacement of the discharge head, and re -fitting the well with a compatible capacity pump, with smaller physical dimensions. The smaller physical dimensions of the new pump are needed to allow proper fit, and future removal from the repaired well casing. The largest single item of the repair estimate is for the replacement of the pump assembly, estimated at $55,000.00. This item also has the longest manufacture and delivery time of all the required components to put the pump and well system back in service. Staff has instructed CDM to proceed with placing and expediting the order for the pump. The scheduled delivery date for the pump is March 14, 2002. Staff intends to purchase the pump directly from the manufacturer. Since the forced removal of the pump and column assembly of well number 4, well pump number 6 has experienced mechanical failure. These problems resulted in the pump being removed from the well and re -inspected. The inspection found that several of the bolts that hold the impeller bowls together were missing. These missing bolts may have caused the failure of the pump. Staff has instructed CDM to proceed with rebuilding / repairing the pump and expediting its return to service. Additionally, staff has requested CDM provide a written explanation on the pump failure. The estimated cost for repairs and labor required for restoring the pump to service is $36,000.00. Staff will be seeking reimbursement for these costs as a warranty claim. Concurrently, Well No. 3 has experienced water production problems. Test results on the well are indicating production short -fall from the well. This condition has required removal of the well form service, and the well is currently unavailable for production. At this time the cause of these problems are still being determined. Staff is working very closely with CDM to correct these problems and expedite the return of well number 3 to service. February 12, 2002 60 8! 1 06