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Home My WebLink AboutGeo-Tech Assessment for BLD2003-01256 - BLD Engineering / Geo-tech Reports - 10/6/2003 MASON COUNTY PUBLIC WORKS DIRECTOR/COUNTY ROAD ENGINEER Shelton,Washington 99594 DATE: October 6`h, 2003 INTER-DEPARTMENTAL COMMUNICATIONS TO: Diane Marcus Jones, DCD -Planner FROM: Alan A. Tahja, P/W- Co. Hydr. Engr. WO#PLG-03 SUBJ: Geo-Tech Review NAME: Buchheit SFR 2 681 Greenview Lane BLD2003-01256 Diane, I've reviewed the geotechnical assessment submitted for the proposed Marc &Lydia Buchheit Single Family Residence(SFR)to be located at 681 Greenview Lane, Mason County. The assessment appears to adequately address slope stability issues, but from staff case notes in TideMark, and from the geotechnical assessment, it seems apparent that the proposed building location is approximately 80 feet from a large ravine containing slopes in excess of 100%, and that a geotechnical report is the appropriate level of reporting that applies to this site. I agree with the engineering geologist,that additional geotechnical investigation and reporting seems unnecessary for this location,but Public Works does not have the authority to relieve the applicant from this County requirement. The applicant should be directed to have their geotechnical assessment completed to meet geotechnical reporting requirements. Please feel free to contact me at County extension 461 if you have any questions regarding these comments,or if you feel any features need further discussion or attention. Sic ely, AlAn A. Tahja TO BE KEPT IN THIE PARCEL FILE File: H: \WP\GEO\Undetermined\Buchheit.doc WORK ORDER - PUBLIC WORKS DEPT. (a Date: (E) Work Order PERMIT M ,) Number. LL7-C3 Requested by: Authodzed by: /. Date: Type -Work: ? j„U CHARGE TO: �r NAME AGENCY/COMPANY ' U BILLING ADDRESS PHONE Pub.Mrks Person in Cha e: (c) i Project Time Une: (from - to dates) TO Pro}ed Start date: 0— —Q Estirnat Finish Date: Appr°Amee hmn: ESTIMATED TOTAL VS: 1079 COST ESTIMATE_ _ (D) pill En44oy*4 Ic Rats ours Frinae% TOTAL$ il< StRII BAIL TOTAL f'3 EQUIPMENT USED: MATERIAL USED: ................ ..:vT.-iM";:>:$iCr.S'H.:`.r-y4;;F.^:Y,'"^.�>2>;%:;;;r>•.c�._.v't�:�....y$,f.,..J�};..�w•w::`-:.:;��::':}�....(�... .. /may{��/ rid%:i:S..'i:. 5:.,'c,+,"`c:S.' r^.t�^..'y.�w�wmi;�do:rr'f J�.MKI�II.tVLtM4:�r.��4J.!w.,»�r4tllYJiCKv��..�G(�fMY/.6-}K if!ri -.r::{u�T�.L-il�`�/Jt�'.i' {iF....is�i�.:q�--,•..-a�J ,,,;.pJ�� rXn�4� .w;.; �.�.:�::j..f.�,K:F-.:.i}�.jy< (17 Actual Cost $ BARS: PROJ C. DATE Employee Name �-�� Flours Ednot% TOTAL$ EQUIPMENT USED: �aiq �LItRate TOTAL SS MATERIAL USED: TOTAL ALL (G) BILLED DATE INV 0 PAID DATE RECJ CKx 13��2Uo 3 - 01 2S(o PLANNING Geotechnical Assessment 681 Greenview Lane Mason County, WA Parcel #321352390011 Prepared for Marc & Lydia Buchheit Shelton, WA by Geotechnical Testing Lab Olympia, WA September 27, 2003 GEOTECHNICAL TESTING LABORATORY MARC AND LVDIA BUCHHETT P.O. Box 344 SHELTON, WA 98584 RE: GEOLOGICAL ASSESSMENT 691 GREEwmw LANE PARCEL 321352390011 N470 15.997' W 123°02.053' Purpose ' The objectives of the geological assessment are to assess the surface and MARC & 'TWA subsurface conditions prevalent at the subject site according to Mason County nuceeE►r Ordinance 17.01.100.E4. A single-family residence is proposed at the above referenced site. Geologic Conditions The subject site is an undeveloped lot Iocated off Greenview Lane, one mile north of Bayshore in Mason County, Washington. The lot is located in an area of moderate residential development; see attached vicinity map. Access to the site is from a small gravel driveway_ The lot is gently sloping to the northeast. -A urge ravine curves around the south and east side of the proposed building site. This ravine is no closer than 80 feet from the proposed building site. At the closest point, the top of the drainage is uphill of the building site. In anticipation of construction,the building site and immediate surroundings have been cleared of vegetation. Slope angles on this site range from 5 percent to 20 percent at the building site to over 100 percent along the ravine. The ravine is heavily forested. The site is partially vegetated with blackberry bushes, salal, ferns, cedar trres,fir frees,spruce trees,maple frees,andAder trees. A ditch controls stormwater along the-access driveway; no surface water was observed at the site during the site reconnaissance. Rapid stream incision(other than the ravine)was not discerned at the site. 7s.;. Y � .r+tl.� f��§ pems l� i• 't � l f;•�YY '.fir 1 ' bra; �� ' �i:M ��"1•r s +. tak� �a A"@C�s'' „ r .n View Looking East at Proposed Building Location 10011 Blomberg Street SW, Olympia, WA 98512 1 -Phone#:{360)754-4612 Fax#:{360)754-4848 AGEOTEcnmcAL TESTING LABORATORY The Soil Survey of Mason County, USDA Soil Conservation Service(1960)has mapped the site soils as a Lystair sandy loam, 5 to 15 percent slopes(Le). The report reads,"The Lystair series consists of somewhat excessively drained, brown, sandy soils that occupy hilly kettles and kames and nearby level outwash plains. They have developed from nearby gravel-free, loose, sandy glacial drift deposited mainly by outwash waters. The soils are somewhat excessively drained and are droughty. They have a low capacity for available moisture. All layers of the soiI-are porous." �2 The Coastal Zone Atlas, Volume 9, of Mason County(MA-22) maps the site as Vashon recessional outwash (Qvr). The slope stability is described as"Generally stable in slopes up to the angle of repose." The foundation stability is-described as"Fair to excellent." Seismic_stahility is described as"good." Groundwater Conditions No groundwater seepage was observed at the site. No wetland vegetation was observed at the site. Based on local well logs, depth to groundwater is approximately 88 feet below ground surface. No surface water was observed in the ravine. Depth to Competent Soil Loose sand is expected to extend from 25 to 30 inches beneath the ground surface. Well logs indicate that hardpan-may.be-expected from-3 to 22 feet belowthe ground surface._A local well log is included in this report. Past Slope Instability .► -j JEW Onsite trees were found to be straight and vertical. No indication of past instability was discerned at the site or the , 4-• adjoining parcels during our site reconnaissance. History of Landslide Activity ° The Relative Slope Stability of the Southern Hood Canal ; Area, by R.J. Carson(1977)classifies the site as Class 1 for slope stability. The classification indicates that the site is stable under normal conditions and represents the most stable of the five classes. d . 10011 Blomberg Street SW, Olympia, WA 98512 2 Phone#: (360)754-4612 Fax {360)754-4,848 GEOTECHNICAL TESTING LABORATORY Potential forl andslide Activity This site has no indication or record of old or recent landslide activity. Even though onsite slopes approach 100 percent,the potential for landslide activity is not a concern for the proposed development. Recommendations There isno Evidence of-sod-erosion anywhere on thesite tosuggestihat 1he.siteshould-be included in the Erosion Hazard Area designation. Site conditions for the proposed development do not warrant a more comprehensive Geotechnical Report. We recommend that no further action is needed unless areas of concern are unearthed during construction. If there are any changes in the loads, grades, locations, configurations or types of facilities to be constructed,the conclusions and recommendations presented in this report may not be fully applicable. If such changes are made, we should be.given the opportunity to review Qur recommendations and Provide-written modifications or verifications, as appropriate. Respectfully, GEOTECHNICAL TESTING LAB �0°4A WaBh�' y 7 Harold Parks,L.G., L.E.G. Gnub* y Senior Engineering Geologist 827 C Ggo`o� HAROLD PARKS 10011 Blomberg Street SW, Olympia, WA 98512 3 Phone#:(360)7544612 Fax#: (360)754-4848 __ �� a ��'.�' ��.:a1►-�_ �_i �� 14- INIO