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HomeMy WebLinkAboutGeo-Tech Report Review - BLD Engineering / Geo-tech Reports - 1/4/2002 MASON COUNTY PUBLIC WORKS DIR.ECTOR/COUNTY ROAD ENGINEER Shelton,Washington 98584 DATE: January 4t', 2002 INTER-DEPARTMENTAL COMMUNICATIONS TO: Michael MacSems,DCD - Planner FROM: Alan A. Tahja,P/W- Co. Hydr. Engr. DCD WON 2002-0002 SUBJ: Geo-Tech Report Review NAME: Fincher Class IV FPA nz�.,_A_,o Parcel No. _____ - : ._ Michael, Zj4,'7003 f s -3,;L The geotechnical reconnaissance (report)prepared by CONSOLIDATED ENGINEERING, for the proposed Michael Finch timber harvest/Class IV conversion have been received and reviewed by Public Works. The reconnaissance report generally meets the requirements for a Mason County Geotechnical Assessment, but lacks the necessary detail or information to be entertained as a Geotechnical Report under Mason County's requirements. Though the reconnaissance report indicates timber may be harvested within the limits of landslide hazard area buffers, the report lacks necessary information and details to accept it for reducing the setbacks required in Mason County's Critical Resource Ordinance. Stormwater runoff issues have not been addressed, so this aspect of the proposal still needs to be addressed by the applicant or their engineer. In summary,the reconnaissance report has been reviewed, and appears to support the need for a geotechnical report conforming to County reporting standards to be submitted for review and approval. A Stormwater Site Plan still need to be developed for the proposed activities. 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. Si Cre y, —r�� Man A. Tahja File: H:\WP\GEO\REVIEWS\Fincher.doc 705 P&WT M NtmtbeR' Audwdzed ( !��n M Ode:_ ):1 Z 3 /a I \ Type of Wodc 7 CHARGE TO: NAME (P)n yo,7;.;,c, TJ, 4- AGENCY/COMPANY BILLING ADDRESS PHONE Pub, Works Person In Charge: !NC!"'�. .:.�',:\���t\ \ t. ��. .-_ \YtR?1 % ' ..�'>.-�... .y.t•.,�ai::.::....:.::.:.xv.wat�CM•.f'fMK'p![n!4%RYA:NWIJY!'M^^COUCfv:CU(:�'M'/.w..: act Project Time Une: (from-to dates) TO p� O Pro}ect Start date: — -oz Esdms(6d Fk9sh Date: W - KApprwimaw bs:oo ESTIMATED TOTAL=s: . J C` m COST ESTIMATE 1 4 Eillfgo5'M S RAIg Hows ;vb( ) Frinat TOTAL$ z w 346 so ty a �' I Im IM TOTAL n EQUIPMENT USED: MATERIAL USED: (F) Actual Cost S BARS: PROD P DATE fnpioyea WORKED Hours ;Vb(oW Frinoc% TOTAL$ EQUIPMENT USED: pale SJ314 at TOTAL VS MATERIAL USED: TOTAL ALL (G) SUED DATE INN/ PAID DATE RECI CKX , MASON COUNTY PUBLIC WORKS DIRECTOR/COUNTY ROAD ENGINEER Shelton,Washington 98584 DATE: February 51h, 2002 INTER-DEPARTMENTAL COMMUNICATIONS TO: Michael MacSems, Planning Dept. B Planner FROM: Alan A. Tahja, P/W- Co. Hydr. Engr. 71J!9,�-0 Z- SUBJ: Geo-Tech Report Review NAME: Fincher Class IV FPA Parcel No 3-21 4 2^ nnnPll Michael, 30 35 Zy qQO,3/- 3 Additional information pertaining to the Fincher Class IV FPA provided by Rolla Boughan, P.E., has been received and reviewed by Public Works. Though the report is scant of information, I find it difficult to claim it does not meet the County's minimum requirements for geotechnical reporting as promoted in Mason County's Resource Ordinance (Ord. No. 77-93, revised 8/29/00). The new material dated 1/16/02 is cryptic in Mr. Boughan's typical style, but with the material contained in the addendum material and the original report, I feel Mr. Boughan's report addresses the issues required by the County in a Geotechnical Report. The site plan submitted contains very little useful information. The site plan appears to be drawn to scale, gives an indication of where north lies, and indicates where on the property the top of slope(T.O.S.) is. Mr. Boughan has also drawn a profile through the length of the property, and it might be surmised that a creek lies at the northerly end of the property. It appears that in Mr. Boughan's opinion, the only important development or geological feature on the property is where the top of slope is. Mr. Boughan indicates hand dug holes were opened near the East property line. I must assume Mr. Boughan explored enough to feel confident in describing the soil horizon(s) as he did, and that he felt his description was adequate to cover the entire property. For a slope stability analysis, Mr. Boughan relies on his observation of the trees on the property. I cannot dispute Mr. Boughan's analysis based on his observations and experience. Mr. Boughan indicates that stormwater runoff will not be changed but improved in time.... With the 125' timber harvest setback required from the creek(Sec. 17.01.070), and no other activity being promoted other than the timber harvest, I cannot dispute the claim. File: E:\Prdy-CutOff\Documents\CMP-rec.doc In summary,the materials submitted by Mr. Boughan appear to meet the minimum requirements of the County's Resource Ordinance Section 17.01.100. Future development of the property following the timber removal, should be required to be investigated for potential stability impacts from those proposals as they are developed, as well as potential stormwater runoff impacts. Please feel free to contact me County extension 461 if you have any questions pertaining to these comments, or if you feel additional concerns need further attention. Si c rely, 1. Aldn A. Tahja File: E:\Prdy-Cutoff\Documents\CMP-rec.doc qualified by Mason County. The Geotechnical Report shall be prepared at the discretion of the Director by a licensed civil engineer with specialized knowledge of geotechnical/geological engineering. The Geotechnical Report may also be prepared by a practicing engineering geologist with special knowledge of the local conditions, provided the work is performed under the supervision of a licensed civil engineer who will stamp the report and attest to the competency of the engineering geologist to perform landslide evaluations in accordance with the prevailing standard of practice. 4. Content of the Geological Assessment W&L. Ncv A C S Je PA,%n A Geological Assessment shall include but not be limited to the following: (1) A discussion of geologic conditions in the general vicinity of the project, and specific soil types at the project site. Soil type identifications shall be consistent with terminology used in the Coastal Zone Atlas (Washington Department of Natural Resources, 1980) or in applicable U.S. Geologic Survey maps (e.g. Geological Map of North Central Mason County, by R.J. Carson, 1976, U.S. Geologic Survey OFR 76-2). Use of Soil Conservation Service soil layer terminology is considered inappropriate for this assessment. (2) A discussion of the ground water conditions at the site, including the depth to water and the quantity of surface seepage. (3) The approximate depth to hard or dense competent soil, e.g. glacial till or outwash sand. (4) A discussion of the history of landslide activity in the vicinity, as available in the Coastal Zone Atlas, the map of "Relative Slope Stability of the Southern Hood Canal Area, Washington" by M. Smith and R.J. Carson, 1977; and the landslide records on file with the Mason County Department of Community Development. (5) An opinion on the potential for landslide activity at the site in light of the proposed development. 5. Content of a Geotechnical Report A Geotechnical Report shall include but not be limited to the following: -' (1) A discussion of general geologic conditions, specific soil types, ground water conditions and history of landslide activity in the vicinity as required for the Geologic Assessment described above. (2) A site plan which identifies the important development and geologic features. (3) Locations and logs of exploratory holes or probes. (4) A minimum of one cross section at a scale which adequately depicts the subsurface profile, and which incorporates the details of proposed grade changes. (5) A description and results of slope stability analyses performed for both static and seismic loading conditions. 7 (6) Appropriate restrictions on placement of drainage features, septic drain fields and compacted fills and footings, including recommended setbacks from shoreline bluffs and the tops of other slopes on the property. ? (7) A detailed clearing and grading plan which specifically identifies vegetation to be removed, a schedule for vegetation removal and replanting, and the method of vegetation removal. (8) A detailed temporary erosion control plan which identifies the specific mitigating measures to be implemented during construction to protect the slope from erosion, landslides and harmful construction methods. (9) An analysis of both on-site and off-site impacts of the proposed development. (10) Specifications of final development conditions such as, vegetative management, drainage, erosion control, and buffer widths. 6. Applicable Standards Geological Assessments and Geotechnical Reports shall be prepared using terminology, descriptions, evaluation methods and mitigation approaches that reflect the current standard of care for practitioners in the field of geologic hazards. The standard of care shall be considered to be represented by , but not limited to, Turner, A.K. and Schuster, R.L. (1996; "Landslides, Investigation and Mitigation", Transportation Research Board Special Report 247, National Mason County Resource Ordinance Revised 8129100 48 CONSOLIDATED ENGINEE RING - CIVIL - STRUCTURAL - SOILS - PLANNING - January 16, 2002 MASON COUNTY DEPARTMENT OF COMMUNITY DEVELOPMENT Michael MacSems, Planning Mason County Bldg. I, 411 N. 5th P. 0. Box 279 Shelton, WA 98528 RE: Michael Fincher, Timber Harvest Geo-technical Report Dear Mr. MacSems: Reference is made to Inter-Dept. Communications from Taja. Please note, encl. 1, stating my Geo-technical Hazards Specialist qualifications, enclosed, herein. I am the most experienced Geo-technical Engineer in Washington. REFERENCE MASON COUNTY RESOURCE ORDINANCE, P. 47, AS FOLLOWS: E. GEOTECHNICAL REPORT 1- Applicability a) Slopes are greater than 40% therefor a geo-technical report is required. b) No slides were observed- This is a Geo-technical Report. c) Not applicable d) Not applicable 2- No waiver is requested 3- Qualifications of preparer--See Encl. 1. 5/(1)- See report dated December 26th. (2) Profile sketch added--See Encl. 2 (3) Hand-dug test holes were opened near the East property line of tract. Soil found was 6 in. of forest humous underlain by sandy-silty glacial till. PO, Box 2321 • Bremerton, WA 98310 • (360) 479-5598 • Fax (360) 377-1376 MASON COUNTY DEPARTMENT OF COMMUNITY DEVELOPMENT Michael Mac Sems, Planning Page 2 January 16, 2002 (4) See Encl. 2 (5) The slope stability of this parcel is excellent as deter- mined by vertical tree trunks. (6) , (7) , (8) , (9) , & (10) Not applicable STORMWATER SITE PLAN There will be little change as the removal of trees will improve growing conditions for ground cover and thus further restrict water flow. GEO-TECHNICAL ASSESSMENT (This letter report and the original letter report dated Dec. 26th are GEO-TECHNICAL REPORTS. ) CRANBERRY CREEK The land features and the set-back from the T. 0. S. exceeds 125 ft. from the edge of this creek. Reference is made to Tahja's comments: Stormwater run-off will not be changed but improved in time with addi- tional ground cover developed naturally from the clearing of overhead tree branches. Yours truly, R. B. Boughan, P. E. GEO-TECHNICAL ENGINEER Encls- ROLLA B. BOUGHAN, P. E. - GEO-TECHNICAL HAZARDS SPECIALIST Report Dated December 26th cc: Eric Herd, Michael Fincher (w/ bill for add'l) w/ Encls. • I I ..---.__..._..-•-----r--r• -- -..-. - ------ --._ ._..._ I � , � I 1 , I I - i I i , � II ill I , i I � � t I I I I , I I 1 I � -r I i , , I ! I I I I I I _ I Encl. I I F . CONSOLIDATED ENGINEERING r � ... - CIVIL - STRUCTURAL - SOILS - PLANNING - :......... ROLLA B. BOUGHAN, P. E. - GEO-TECHNICAL HAZARDS SPECIALIST I, -Rolla B. Boughan, am a qualified geo-technical engineer licensed as a civil engineer in the state of Washington with a minimum of twenty years' experience in land slide evaluation. The city of Portland, Oregon, adopted a Landslide Potential Evaluation Form which I, as an experienced geo-technical civil engineer, used in inspecting steep and soil hazardous property for construction. Previously, I had been heavily experienced in designing retaining walls and soils revetments. At Purdue University, where I graduated as a civil engineer, I worked as a student assistant in the soils testing laboratory and took courses in soils and geology. I have performed many geo-technical investigations and written reports on soil hazards for construction in Kitsap, Jefferson and Mason Counties during the past few years. Our firm has worked with other civil engineer geologists on recent projects with excellent coordination and good overall results with references available from these other professionals. As a pile foundation design engineer, I am very experienced and much in demand and have excellent references from jobs recently completed. I am a member of the Pile Foundation Institute. �$l,/^/ y9 co Rolla B. Bougha , P. E. Q 0D.-.913 GEO-TECHNICAL HAZARDS SPECIALIST I1:ALE EXPIRES P.O. Box 2321 • Bremerton, WA 98310 9 (206) 479-5598 • FAX (206) 377-7556 O 1+ S LI DATED GhOEERh I G - CIVIL - STRUCTURAL - SOILS - PLANNING - December 26, 2001 Mason County; P. 0. Box 186 Shelton, WA 98584 RE: GEO-TECHNICAL RECONNAISSANCE OF TIMBERED SLOPE PER LEGAL DESCRIPTION BELOW ATTN: Michael McSins /`1acSQ W15 Dear Mr. McSins; The undersigned Geo-technical Engineer, along with Sam Wilson, Soils. Technician visited the site for a preliminary walk-over soils reconnaissance With Eric Hurd, Logger on December 18th. The site was investigated to determine the stability requirements for the harvesting of timber. The property is covered with evergreen trees, all of which exhibited vertical trunks. The older trees are tall, straight evergreens throughout the tract therefor indicating no soil instability here in the recent past. The tract measures 330 ft. X 1,320 ft. and has recently been surveyed. The upper portion of the land slopes downward toward Cranberry Creek at an angle of 120 to 150 as measured with a Smart Level. There is a distinct break, Top of Slope (T. 0. S.) , some distance from the creek which is estimated at 300 to 506 downward. Timber to be cut should not be closer than 15 ft. from this steep T. 0. S. ; stumps and roots are to be left in place. The literature for a background on geology and slope stability shows no previous instability on the South Side of Cranberry Creek in this vicinity. MA22, Mason County - There are no nearby areas of poor slope stability noted in the Coastal Zone Atlas of Washington. In my professional opinion, timbering off the upper slope should not affect the land stability of this tract. Yours truly, Rolla B. Boughan, P. E. Civil & Geo-technical Engineer LEGAL DESCRIPTION OF TRACT: Section •i5, Township 21 N, Range 3 W. Parce \,# !.3213523. Owner Michael Fincher cc: Eric Hurd, LoggeZ PO, Box 2321 • Bremerton, WA 98310 • (360) 479-5598 • Fax (360) 377- 1376 MASON COUNTY DEPARTMENT OF COMMUNITY DEVELOPMENT Planning Mason County Bldg.1 411 N.5th P.O.Box 279 Shelton,WA 98584 (360) 427-9670 Belfair (360) 275-4467 Elma (360) 482-5269 Seattle (206) 464-6968 Eric Herd Hood Canal Logging P.O. Box 1816 Belfair, WA 98528 January 7, 2002 Dear Mr. Herd, This letter is in response the "Geo-Technical Reconnaissance" submitted by Rolla Boughan (Consolidated Engineering) for the Michael Fincher FPA. This document comes close to being a"Geo-Technical Assessment" as discribed in the Mason County Resource Ordinance, section 17.01.100.E.4 (enclosed), but is no where near meeting the standards for a"Geo-Technical Report" (section 17.01.1OO.E.5), which is what your client needs in order to log west of Green View Lane. I did forward Mr. Boughan's document to the County Engineer, Alan Tahja, for review (at a cost to the applicant of $36.50) and am enclosing his response. If Mr. Fincher wants to proceed with a Class IV General forestry permit, for that portion of his land that lays west of the road, a complete geo-technical report will simply have to be done. There is no way to avoid this under the County regulations. Withdrawing the permit and applying instead for a Class III directly from the DNR is still an option, if Mr. Fincher would prefer. Please call me at ext 571 and advise me as to how your customer wishes to proceed. Sincerely, V Michael MacSems FPA Planner cc: Michael Fincher encl.- Mason County Resource Ordinance, section 17.01.100.E IDC from Alan Tahja, County Engineer Original conditions from SEPA 2001-00097 FOR EST PRACT I CE BAS E MAP TOWNSHIP 21 NORTH , RANGE 03 WEST ( W . M SECTION 35 A P P L I C A I 1 0 N I EB i 0 _ v r ARE 6PN6� /� 3 87 385388 385 6 384ee7 384228 / 2 6 363 383068 83 SCALE 0 I m 2000 0 4000 5000 6000 FEET 1 We (5m y) MAP DATE. November 26, 2001 r CONTOUR INTERVAL : 40 Fee , LEGEND: See Instructions ( NAD 27 DISCLAIMER: See Legend Water/Wetlands including their location and class may be incorrectly displayed or not shown on the Base Map. Applicants are responsible for verificatlon and correction of all streams. wetlands, and possible water courses. SCALE I " = 400 r: 2290030 i Z 2200040 Zoo,i IC41z gO013 , 700, 91, 2172 21 00010 21 00000 sP, 186.5 5 ZZ/o 2290031 S Z��t 51P 22 00000 22 00020 21 00020 22 .00030 L�°c ( Op 23 q D r23000210 2390000 1 �1 5 20/3I SP 2LS�S J� ' 1 3 0 2400030 2400020 2400010 2400000 2390030 i 341.W 23 %ooi/ 2390 1 it 3q G/1rV - - - - - - - SP 1102 N 020 / t\ - 11U - 2390 �239004_O_- : 0 1 0 °� 01% N H 344.51' 1379.OS' 4 32 00000 n 31 00000 i N O N_ n S 8/60 n FOREST PRACTICE BASE _ M AP TOWNSHIP 21 NORTH , RANGE 03 W L S I ( W . 6f I10i� zj A P F l I C A l 1 0 N �� 11 i; OIL ® � CQPNB(t� 3 67 385386 4'1385 /Eil \ 6 — �64L \ 384228 6 !� 383 383068 383 Sul TE 2000 no aooa 5000 6000 _ --.,TTT FEET 1 We (sao nl MAP DATE. November 26, 2001 ' CONTOUR INTERVAL : 40 Feet LEGEND: See Inslfuctions NAD 21 DISCLAIMER: See Legend Water/Wetlands including their location and class may be incorrectly displayed or not shown on the Base Map. Applicants are responsible for verification and correction of all streams. wetlands, and possible water courses.