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Bremer Financial Corporation Project B2008939 November 17, 2020 Page 9 only below foundations and their oversize zones. If this option is chosen, additional soil observations and testing can be performed during site preparation to reduce the risks. Extensive debris, if encountered, can be a challenge for this technique. This approach is further explained in Section C.4. C.1.b. Reuse of On-Site Soils If the soil correction approach is chosen, the existing, non-organic, debris-free, fill and native clays, silty sands, and sands are suitable for reuse as engineered fill below the proposed building pad. Some of the soil borings encountered debris and slightly organic material, and there could be more debris and soils with higher organic content than revealed by the borings. We do not recommend reusing existing fill that contains debris or organic material as structural fill. The on-site clays can be challenging to reuse, as they have a narrow range where moisture contents are suitable for compaction. Clays are more difficult to compact and they can easily become disturbed during construction. The clays may need moisture conditioning to achieve compaction which will require space to spread the soils, time, and favorable weather to dry them. C.1.c. Groundwater We did not observer groundwater in our borings, therefore we believe it is below the anticipated excavation depths for construction. Some of the soils, such as silty sands, clayey sands and clay, will collect water from precipitation or if water drains to the site. We recommend the contractor remove any water that collects in work areas before performing further work. C.1.d. Construction Disturbance The contractor should note the on-site, silty and clayey soils are highly susceptible to disturbance, due to repeated construction traffic. Disturbance of these soils may cause areas that were previously prepared, or that were suitable for pavement or structure support, to become unstable and require moisture conditioning and compaction. Subcutting and replacing the disturbed material with crushed, coarse gravel, free of fines is also an alternative. The contractor should use means and methods to limit disturbance of the soils. C.1.e. Pavement The existing fill consists of a variety of materials and strengths. This vari ability creates the potential for irregular and, in some cases, poor pavement support. The risk of irregular performance exists unless construction includes excavating and removing or recompacting the fill. Due to the cost associated with this approach, owners rarely choose to re-engineer deeper layers of fill. Occasionally, contractors will