Discussion:
On April 21, 2020, City Council awarded the Unbridled Avenue Project CIF-20-014 to Geislinger & Sons, Inc. Since early May, Geislinger & Sons has been busy constructing the roadway, storm sewer, streetscaping, and storm water ponds.
During recent construction and excavation of the large stormwater treatment pond on the west end of the project limits, it was determined that the actual bedrock elevation at the bottom of the pond was higher than the elevation that was estimated during the initial pond design and included in the contract bid items. Although some soil borings were performed in the area of the pond during the preliminary design, the large area of the pond and the uneven and undulating nature of bedrock can make it difficult to predict the exact quantity of bedrock excavation at the time of design.
Blasting and excavation of the extra bedrock has already been completed and the attached Change Order includes the necessary work (see attached revision). A summary of the work as part of this change order includes additional quantity for rock excavation and a reduction in the equal volume of common excavation (granular) material needed to construct the pond.