Project UT1202 Contract 1 Emergency Traveling Screen Repairs - Complete
The Kaw Water Treatment Plant Sand Screen is part of the raw water intake and Low Service Pump Station 2 pumping system at the Kaw WTP. The screen is installed to intercept debris ahead of the raw water pumps. The screen was installed in 1988 and due to the hostile service environment had reached the end of its reliable service life. The equipment was out of service on multiple occasions the summer of 2012 due to drive system failures. During the process of repairs it was found that a number of direct replacement parts for the motor and gearbox system were no longer available. In March 2012 Staff coordinated an inspection of the screen by a representative of the manufacturer Siemens. Based on the inspection an aggressive rehabilitation of the equipment and replacement of worn parts was proposed while maintaining the existing structural frame. The screen rehab was scheduled for Spring 2013 along with the replacement of four (4) each deteriorated 16” to 30” butterfly valves in Low Service Pump Station 2.
Due to long lead times, 8 – 10 weeks, the desire to complete the work by Summer 2013, and the proprietary nature of the parts, in December 2012 the City pre-purchased the parts required for the rehabilitation from the equipment manufacturer Siemens Industry Inc.
The screen rehabilitation and valve replacements were originally bid on January 29, 2013 as part of a larger Kaw WTP Electrical and Mechanical Improvements Contract 1 project. CAS Constructors LLC was the sole bidder with a bid significantly over the estimated cost of the project. Department Staff and representatives from the design engineer Black and Veatch met with CAS Constructors LLC to review the bid and determine the best way to execute the project. Based on these discussions it was recommended to complete the critical traveling screen and valve repairs under separate contract and rebid the remaining electrical and mechanical work during the summer of 2013 and provide a longer construction schedule for these components thus lowering the expected bid costs.
On February 19, 2013 the City Commission authorized the execution of contracts with Siemens for the rehabilitation of the traveling water screen, and CAS Constructors LLC for support activities and the replacement of four (4) each 16” to 30” butterfly valves in Low Service Pump Station 2. Siemens staff mobilized on site on Monday April 1, 2013, and on Tuesday April 2, 2013 began disassembly of the traveling screen. On Wednesday April 3, 2013 during disassembly of the traveling screen additional chain rails and an intermediate frame panel exhibiting excessive corrosion we found. These parts were not accessible during the initial inspection performed by Siemens in March 2012 upon which the originally authorized parts and labor purchases were based. The location of the parts to be replaced required the removal of the traveling screen head unit and intermediate frame sections not included in the previous quotation. The additional parts were purchased by the City, provided and installed by Siemens with only 2 days delay to the overall project schedule.
Siemens completed the rehabilitation and startup of the traveling screen on Monday April 15, 2013 and CAS completed the replacement of the valves and Low Service Pump Station 2 was placed back in service on Tuesday April 23, 2013.
Project Costs
Traveling Screen Rehabilitation
Wet Well Cleaning $10,750.00
Traveling Screen Parts $68,150.26
Siemens Contract for Labor $47,741.00
$126,641.00
In 2011 Siemens quoted replacement of the traveling water screen at $210,900.00.
Valve Replacement and Auxiliary Pumping to Keep the Plant in Service
CAS Contract for Labor $19,756.00
Four (4) Butterfly Valves and Shafts $18,693.00
Auxiliary Raw Water Pump Rental $14,597.00
Auxiliary Pump Fuel $7,344.00
Overtime to Fuel and Check Pump $836.00
$61,226.00
Project Total $187,867.26