1212 GRAND AVE 2016-01-01 MF Import

March 31, 2008 Mr. Paul Tessier L&A Job No. 8A027 Page 7 dense sand ancUor hard silt soils laycr in arcas of the proposed additions to the existing residence and the new garage. The exposed soils after stripping should be compacted to a non-yielding statc with a mechanical compactor. During constcuction, one or multiple lines of interceptor trcnch drains should bc installed along the uphill side of the site and behind the crest of the steep slopc, as rcquircd, to intercept and drain away surface runoff and near-surface groundwater scepage to facilitate grading and foundation construction work. Water collected in such interceptor trench drains should be convcycd into a nearby street side storm inlet. The stortn inlet should bc covered with a filter sock to prevent sediment fmm entering the stortn sewer system. Thc filtcr sock shoulJ be cleancd perioJically to prevent it tiom clogging,and should be removed aRer lhc construction work is completed. The onsite surticial soils contain a high percentage oC fines and are sensitive to moisture. A layer of cican quarry spalls should lx placed, as required, over cxcavated areas and are:u of frequent traffic to protect the subgrade soils from Jisturbance. Silt fences should be erected along the downhill sidc boundaries of the site to prcvent sediment from bcing transported by storm runoft' onto adjoining propertics, thc street or the adjacent sleep slo�:. The bottom of silt fence filter fabric sl�ould bc anchorcd in a trcnch fillcd with gravcl. F,XCAVATION SLOPES Under no circumslance should excavation slopes be grcatc: ihan the limits specitied by local, state and fcderal safery regulations if workers have to pedortn construction work in excavated are:+s. Unsupported tcmporary cuts grcatcr th:ui 4 fect in hcight should be no steeper than 1 H:l V in thc surficial topsoil and weak soils in the root zone, and no steeper than 1l2H:lV in the underlying dcnse sand and/or harJ silt soil layers. The soil units and lhe stability of cut slopes should tx vcrificd by a gcotcchnical enginccr durmg cxcava,�on. LIU & ASSOCIATES, INC.