R2024-344 Resolution Accepting the Bid and Authorizing the Execution of a Contract with Burdick Plumbing and Heating Company, Inc. for the Vulcan Watermine Pipeline, City Project 2022-22

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Bus DE-WATERING CONSIDERATIONS It should be noted that groundwater was encountered near the surface, or at mid-depth, in the test borings. This water is believed to be seepage of precipitation, which was trapped in the upper soils. At several locations, depending upon the encountered sandy soils and the invert elevation of the gas pipeline, some water, which could adversely impact the slopes, may be encountered during excavation. Therefore, water intrusion into the excavations, and any deep structure excavations should be expected and provided for in project budgeting. Most of the water will likely enter through layers and pockets of water bearing soils and sands. In our judgment, most of the water can be controlled by normal sump pumping methods. However, if large water-bearing zones are contacted during the excavation process, more elaborate water control methods may be required. Seepage water will serve to reduce the stability of trench ' excavations. Hence, it may be necessary to provide trench boxes or trench bracing in zones of heavy seepage, for project safety. Furthermore, de-watering can adversely affect nearby structures. ' EXCAVATION SLOPE SAFETY The contractor should be aware that slope height, slope incline, or excavation depths (including ' trench excavations) should, in no case, exceed those specified in local, state, or federal safety regulations (e.g., OSHA Health and Safety Standards for Excavations, 29 CFR Part 1926, or rsuccessor regulations). Such regulations are strictly enforced. If they are not followed, the owner, contractor, and/or earthwork and utility contractors could be liable for substantial ' penalties. As can be seen from the boring logs, most of the pipeline will be in Type "A" or Type "B" soils. However, it should be noted that some Type "C" soils may be encountered anywhere along the pipeline because of the site geology or site use (fill). The contractor needs to be aware that soils to be penetrated by the proposed pipeline excavation may vary significantly from those found during drilling. The soil classifications were determined based upon the soils encountered within the exploratory borings. If different subsurface conditions are encountered at the time of construction, SKS recommends we be contacted immediately to evaluate the conditions found. For excavations extending to a depth of twenty (20) feet more, it is necessary (per OSHA) to have the side slopes designed by a professional engineer, registered in the State of Illinois. Geotechnical Exploration for Sanitary Pipeline New Vulcan Waterline Pipeline, Decatur, Macon County, Illinois SKS Project No. 12-418885 Page 11