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r <br /> Marcli 1 d. 2010 <br /> /�dJition to Stccvcs Rcsidcncc <br /> L&A .lob No. 10-008 <br /> Pagc (, <br /> excavation on thc 12cf'crence Sitc. 'fhis seeping ground��ater was perching on top ol�the <br /> undcrlyine tine sancly silt deposit which ���as of extremely low permeability. <br /> We expect the groundwater conditions at the subjcct residence site to be similar to those <br /> at thc Rcfcrcncc Sitc. "fhc ncar-surfacc perclicd groundwatcr �vould tluctuatc scasonally. <br /> a�n�„a;�,� �,�, rr«�p��ation, sw�lacc runo�7: vcgctation covcr. sitc utilization. ctc.. It may <br /> dr�� up complctcl�� in thc drycr summcr months and accumulatc and risc in thc wct wintcr <br /> months. 'I�hc perchcd ground�vatcr would Ilo�v down-gradicnt along thc surfacc of the <br /> underlying fine sandy silt deposit. lt is our orinion the shallow perched groundw�ter <br /> should havc miniinal imp�ut on thc stability of thc stccp slope ���ithin and bclow thc sitc. <br /> providcd that ��cgctation covcr on thc stccp slopc bc prescrved and maintaincd and that no <br /> cunccntratcd slorm���atcr bc discharecd uncontrollcd within thc subjcct sitc or onto thc <br /> adjaccnt stccp slopc. <br /> DISCUSSION AND RECOMMENDATIONS <br /> GEOLOGIC HAZARDS AND REMEDIATION <br /> Landslide Hazard <br /> 'fhc sul�jcct resicicncc sitc is most likcl�' manUed by a thin laycr of topsoil undcrlain by a <br /> laycr of dcnsc linc to mcdium sand about 2 to 3 f'cct thick, which is in lurn underlain b� a <br /> hard tinc sand� silt drposiL 'I'hc dcnsc s�ind and hard silt soil laycrs underlying thc <br /> sul�ject residence sitc are of high shcar strengih and have excellent resistance against soil <br /> movr.mcnt and slopc failurc. Although thc stccp slopc bordcring thc �vest t�ingc of thc <br /> cast bench of the sutiject site stands at an inclination ovcr 40 perccnt with a vertical rclicf <br /> LIU & ASSOCIATES, INC. a J J 1 <br /> / _ ` � <br />