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Project: WPCF Chlorination Building Upgrade <br /> Change Order No. 04 <br /> Change Order Effective Date: March 31,2020 <br /> CONTRACTOR <br /> Digdayyllgned by CJ Handforth <br /> CJ Handforth owD� <br /> £chandferth@imcoconstruc6on com, <br /> DN dforth April 1 , 2020 <br /> Date_2020 02D 04 07 10 32 23-07'00' <br /> By Date: <br /> Officer <br /> Exhibit A—Description of Changed Work <br /> Change Order#4 adds one (1) new Item#13,titled—Combined Work Change Directives 37, 38&41 <br /> to the Contract in the agreed to lump sum price of$26,734.56. <br /> Individual work change directives are defined & justified as follows: <br /> Work Change Directive 037: Revise Sodium Hypochlorite Metering Pump Piping. <br /> Increases the Contract Amount by$10,000.86. <br /> Work Change Directive 038:Temporary Repairs at Outfall Manhole. <br /> Increases the Contract Amount by$11,626.70. <br /> Work Change Directive 041: Carrier Water Pumps Piping Revisions. <br /> Increases the Contract Amount by$5,107.00. <br /> JUSTIFICATION: <br /> Work Change Directive 037:The per plan piping layout for the hypochlorite and ammonia metering <br /> pumps did not allow the pressure measurement instrumentation to measure the discharge pressure <br /> of the metering pumps. Measurement of the pump's discharge pressure is required for the proper <br /> control of the metering pumps. WCD 037 revised the piping so the pump's discharge pressure could <br /> be measured. <br /> The per plan piping layout for the hypochlorite metering pumps did not allow one of the two pumps <br /> to be isolated for maintenance, while the other pump remained online, providing disinfection. <br /> Extensive modifications to the inlet and discharge piping were required. <br /> The per plan piping layout for the hypochlorite and ammonia metering pumps did not provide <br /> support for the pressure and flow measurement instrumentation. The instrumentation was held in <br /> place by the process piping only. Without proper support of the instrumentation, the process piping <br /> will develop leaks jeopardizing operations and maintenance personnel, as well as the disinfection <br /> process. WCD 037 added supports for the pressure and flow measurement instrumentation. <br /> Page 3 of 4 <br />