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HomeMy WebLinkAboutGeological Assessment Letter - BLD Engineering / Geo-tech Reports - 10/12/2005 PO Box 44890 Tacoma WA 984" 253-537-94M 253-537-9401 fax E3RA October 12,2005 T06372 Eric Dunaway 12216 59 b Avenue NW Gig Harbor,Washington 98332 (253)405 9833 Subject: Geological Assessment Letter Parcel# 12331100070 251 Jolly Roger Lane NE Belfair,Washington Dear Eric: E3RA is pleased to submit this Geological Assessment Letter for your residential lot at 251 Jolly Roger Lane NE in Belfair, Washington. The purpose of our assessment is to address Title 17 of Mason County Critical Areas Ordinances as they relate to landslide hazards on the site. Plans call the construction of a single-family residence with a daylight basement. Our scope of work is limited to surface observations, geotechnical research, and letter preparation. This report has been prepared for the exclusive use of Eric Dunaway and his consultants, for specific application to this project,in accordance with generally accepted geotechnical practice. PROJECT DESCRIPTION The project site is an irregularly-shaped parcel that measures 75 feet on the north boundary at Jolly Roger Lane NE, 90 feet on the south boundary, and extends 130 to 134 feet south from Jolly Roger Lane NE. It is located in the Lynch Cove area west of Belfair,Washington. Plans call for the construction of a residence with a daylight basement on the site. The high wall of the daylight basement will support an existing cut into soils on the site. SITE CONDITIONS During our reconnaissance of the site and nearby areas on October 11,2006,we observed that a driveway that leads to the neighboring parcel to the west a driveway crosses the northwest corner of the site. We also observed that the site slopes down to the south from the driveway and Jolly Roger Lane, initially at about 30 percent. At a distance of 25 to 30 feet from Jolly Lane, grades increase steeply at a cut, 8 to 9 feet high, that was made into the slope. The cut face is graded at about 1%2H to IV. South of the cut, slopes modify to 20 percent or less and continue sloping gently down offsite to the south. Slopes within 250 feet of the site are similar or gentler than those onsite. October 12, 2005 ORA, Inc. T06372/Dunaway Jolly Roger Landslide Letter Soils onsite exposed in the cut consist of medium dense Vashon recessional glacial outwash comprised of gravelly sand with few fines. Excavations nearby the site are also of this soil type. No groundwater was observed in the cut onsite.No surface expressions of groundwater, such as seeps or springs, were observed onsite or nearby offsite. No streams, streambeds, or other hydrologic features indicating surface flow were observed. We did not observe indications of ancient, recent, or incipient slope instability, such and hummocky terrain,scarps,landslide blocks,tension cracks,or any other features indicating unstable slopes on the site or within 250 feet of the site.. The Coastal Zone Atlas maps slopes on the south two thirds of the site as S, Stable. The same reference maps the north third of the site as either I, Intermediate or as S. Stable. Intermediate slopes are generally steeper than 15 percent, have no known slope failures, and include slopes of sand and gravel.-till,or thin soils over bedrock. Vegetation on the site currently consists of weeds, high grass, scotch broom; several small firs and pines grow on the northeast corner of the site. CONCLUSIONS AND RECONEWENDATIONS Groundwater conditions do not adversely affect slope stability on the site, and groundwater will probably not be encountered during site development. Sufficiently consolidated soils, adequate for foundation support, were, in general, observed at a shallow depth in the cut onsite. In our opinion, the proposed development will not create unstable slope conditions onsite or nearby offsite. In our opinion, no further geologic or geotechnical study is necessary to further evaluate site conditions and the proposed development of the subject property. CLOSURE The conclusions and recommendations presented in this report are based, in part, on our interpretations and assumptions regarding subsurface conditions; therefore, if variations in the site conditions are observed at a later time,we may need to modify this report to reflect those changes. i October 12, 2005 E3RA, Inc. T06372 /Dunaway Jolly Roger Landslide Letter We appreciate the opportunity to be of service on this project. If you have any questions regarding this report or any aspects of the project,please feel free to contact our office. Respectfully submitted, E3RA, Inc. `0 of W a s � bra • �w.�s.obgl�t .co` oe 71.1 used Geo� Fred ErneSt Rennebaum Fred Rennebaum, L.E.G. Senior Geologist, E3RA P.O Box 44890 Tacoma, Washington 98444 (253)537-9400 DEC-04-2006(MON) 18:54 BILLINGS RANCH GOLF GROUP (FAX)541 608 3841 P. 003/003 ti©V,BR-zOfJE 12:45P FROM:F-PENNESAUM 360-405-6378 TQ:12538752418 P.1 PO Box 44890 Tacoma WA 88444 253-537-9400 253-537-9401 fax E3Rq November 28,2006 �, N •4 T06372 ���1:.• , Eric Dunaway and Reed Peru DEC i 12006 12216 5911 Avenue NW Gig(253�405 9$33oashingtat198332 'ASOM MAN Q►J��.�CV�lOP,'i�S Subject: Geological Assessment Letter Update ' Parcel# 123315100070 251 Jolly Roger Lane NE l3cMir,Washington Dear Eric and Reed: E3RA is pleased to submit this Geological Assessment Letter Update for your residential lot at 251 Jolly Roger sane NE in Belfair, Washington. The purpose of our letter is to update the information presented in our Geologic Assessment Letter dated October 12,2005. The site and geologic conditions described in our Geological Assessment Letter, dated October 12, 2005, arc unchanged and the Conclusions and Recommcndations presrntcd in that letter remain the same. We appreciate the opportunity to be of service on this project. If you have any questions regarding this report or any aspects of the project,please feel free to contact our office. Respectfully submitted, e 0 as /0 MRA, Inc. c'B 711 0 7Sed G0�` Fred Rcnncbaum,L.E.G. Fred Ernest Rennebaum Senior Geologist,MA P.O Box 44890 Tacoma, Washington 98444 (253)537-9400 DEC-04-2006(MON) 18:54 BILLINGS RANCH GOLF GROUP (FAX)541 608 3841 P. 002/003 -MIRDevelopment , LLC 183314 75th Ave.East• Puyallup.Washington 98375• (253)875-2418•E-mail:reed@mrdevelopmentllccom Attention: Chuck This is in regards to the conversation with Jennifer Runaway last week. This letter is stating that nothing has cbanged in the last six months at our building lot. If you have any other questions please contact me,Reed Peru, at the above fax number or email address. Thank you. Sincerely, Reed Peru Project Manager