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These are well suited for pavement support and are considered non -frost susceptible and are also <br />free draining materials. <br />The origin of the Fill encountered in the borings is unknown but is likely associated with roadway <br />construction and/or any existing underground sanitary sewer, storm sewer or watermain utilities. <br />The Fill was also composed of poorly graded sand and poorly graded sand with silt and is <br />generally well suited for utility and pavement support. <br />Where spot fixes of the utilities will occur, we anticipate that the soils excavated for utility repairs <br />will be reused to the greatest extent possible. The Fill encountered in the borings in our opinion <br />is suitable for reuse. We recommend that any buried topsoil, organic soils and any soft or <br />otherwise unsuitable materials, if encountered, be removed and replaced with suitable compacted <br />engineered fill. <br />Groundwater Ground water was encountered in 5 of the soil borings at depths of about 81/2 to 14 <br />feet below the ground surface. With pipe inverts anticipated to bear about 7 to 10 feet below the <br />ground surface there is the potential that groundwater could be encountered during spot utility <br />repairs and dewatering could be required. <br />4.3 Utility Recommendations <br />Spot utility repairs could be included in this project. The existing utilities are anticipated bear at <br />depths ranging from about 5 to 10 feet below the ground surface. At these depths, the existing <br />pipes likely bear on sandy alluvial soils or compacted engineered fill which in our opinion are <br />suitable for pipe support. We recommend removing all vegetation, topsoil, organic soils and any <br />soft or otherwise unsuitable soils, if any, beneath utilities prior to repair or placement. <br />We assume that open cut excavation techniques will be used for pipe installation. We further <br />assume that typical excavations depths will be on the order of 5 to 10 feet below the ground <br />surface. At typical 1:1 excavation backslopes, the excavation will extend about 5 to 10 feet beyond <br />the edges of the excavation. The excavation may extend into/ onto adjacent properties posing a <br />risk of undermining structures on those properties. In addition, the soils could slough as they are <br />excavated resulting in side slopes flatter than 1:1 further increasing the horizontal limits of the <br />excavation. If site constraints will limit the excavation, trench boxes or temporary shoring may be <br />required. <br />Backfilling New pavements will be constructed over the top of the utility trench(s) and the soil <br />excavated for pipe installation will likely be placed back in the excavations, to the greatest extent <br />possible. As noted above, the Fill encountered in the borings in our opinion is generally suitable <br />for reuse. We recommend that any buried topsoil, organic soils and any soft or otherwise <br />unsuitable materials, if encountered, be removed and replaced with suitable compacted <br />engineered fill. <br />We recommend bedding material be thoroughly compacted around the pipes. We recommend <br />trench backfill above the pipes be compacted to a minimum of 95 percent beneath pavements, the <br />exception being within 3 feet of the proposed pavement subgrade, where 100 percent of standard <br />Proctor density is recommended. In landscaped areas, if any, we recommend a minimum <br />compaction of 90 percent. <br />8 <br />