IMCO General Construction Inc. 11/4/2020 Change Order 5

Project: WPCF Chlorination Building Upgrade Change Order No. 05 Change Order Effective Date: September 20, 2020 CONTRACTOR . 114J\41.61 By Date: AlP l f/Lr,�,il c,-<< flicer Presidcn-f'/ C Exhibit A—Description of Changed Work Change Order#5 adds two (2) new Items. Item#14, titled— Emergency Culvert Repairs, and Item #15, titled FEN Outfall Manhole Repairs, are added to the Contract in the amount of$211,119.29. Costs are being tracked by the force account method. Individual items defined & justified as follows: Item No. 14: Emergency Culvert Repairs. Excavate the ends of the existing 24-inch CMP culvert. Install an 18-inch HDPE liner pipe through the culvert. Leave several feet of the liner pipe exposed on the river side of the dike. City forces will install a tide gate at this location. Seal the annular space between the liner pipe and the CMP culvert. Backfill and compact the excavation. Armor the side slopes of the backfill with 4 to 8-inch quarry spalls. Restore the crushed rock trail/road. Spread topsoil along the sides of the trail/road. Place erosion control matting over the topsoil and hand broadcast grass seed. Increases the Contract Amount by$69,359.13. Item No. 15: FEN Outfall Manhole Repairs. Excavate the existing FEN outfall manhole. Clean out the annular space between the 96-inch manhole and the 120-inch manhole. In areas where the annular space cannot be cleaned adequately to place concrete, pressure inject De Neef Cut PURe chemical grout to fill the annular space. Sawcut the 120-inch manhole at approximate elevation 7.5. Dowel #4 reinforcing steel at 10" O.C. into the 120-inch manhole at elevation 7.5 and in the cut-out below the 48-inch effluent pipe. Embedment depth of the dowels shall be a minimum of 4-inches. Epoxy for dowels shall be Hilti NIT- RE V3. Install a reinforcing steel cage consisting of#4 reinforcing steel at 10" centers each way. Install two additional #4 trim bars all the way around the existing 48-inch effluent pipe, where the pipe passes through the reinforcing steel cage. Weld five each, 1/4" angles onto the 48-inch effluent pipe. Angles shall be spaced evenly between 3 o'clock and 9 o'clock over the top half of the pipe. Weld #4 reinforcing steel onto the angles. Extend the#4 reinforcing steel into the reinforcing steel cage, lap splicing bars at least 5-feet. Coat exposed #4 bar pipe restraints with a primer and an asphalt-based topcoat. Place a 144-inch CMP pipe over the reinforcing steel cage, for use as a form. Place 5000 psi concrete into the form and in the annular space between the 96-inch manhole and the 120-inch manhole. Remove the 96-inch manhole cover and replace the asphalt mastic gasket with a new asphalt mastic gasket. Reinstall the manhole cover. Page 3 of 4