4708 SEAHURST AVE 2016-01-01 MF Import

Geotechnical Engincering Gv� tion 4708 Seahurst Avenue--Carter September 17, 2006 RMI Filc No. 37I06 Pagc 3 Gcologic Conditions Landfomis within Ihis region comprise a system of gl:�cially sculpturcd fcatures. �vhich ha�c bcen cxposcd by pos�-glacial crosion. I.ocnlly, thc tcrrain of L'iis arca has bccn �laciall�� modificd. Thc soils �acre placed ci�hcr prior to, ur during the lale,� glae..dion of thc Puget Lu�� land arca. Glacinl icc last occupied Ihc rcgion Juring ihe la�c Pleislocene c�;nch. somc 10,000 �o I 1.000 �cars hefixe ihe presen�. 'I hc lalcsl glacial ad��ancc ovcr the ��rca is rcfcrrcd lo as Ihc Vashon tiladc oflhc I`rascr (ilacialinn •hich dcpnsitcd ihc glacial malcrials on silc. Litcraturc Rcvicw Thc Gcologic Mnp of Surficial Dcpositti in ihc ScatUe 30-by GO- minutc Quadranglc by Younl ci al nntcs ihal ihis arca contains U�c Vashon till, Q��t, al highcr cic��ations and ad�ancc ou�wash depmits, Qva. bclo�v in thc ra��incs. Sitc Conditions We ohscrved soil esposures on Ihe site. "I hese obscrvalions confirtned the esistr��c of the Vaslion till. Hydrologic Conditions No wnlcr was obscrvcd un thc surfacc and no ��alcr u, t..iscn•ed on thc slopc. Slopc Stabilit�• 1'hc corc of thc lot comprises glacially cumpacicd dcposits of till undcrlain h3 ad�ancc ouh�ash sands anJ gravcls/cobblcs at depth. \i'c Jid nol obscrvc signs of dccp-scatcd slopc failures and ��ould nol cxpecl a�iy. 7'here wcrc no signs of instahility on ncighboring propertics. It is our opinion thnl there is not a significant potential for deep-seated slope instability. Signs of hackwasting (movement of ncar-surface soiq �hrough exposcd soil erosion processes or local surfacc slides are common lo slccp slopes, particularly wherc eaposed to ��cathcring. such as rain, wind. :md frcc�c-Ihn�+'. '1'hcrc �vcrc no percepiihlc signs of significant backwes(inE. RMI ASSOClATES LtC �,��b