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Home My WebLink About502151017 Geotech Assessment '" I ~ I I I I I I I I I I I I I I I I I I Subject Property "~\ .,' "f; GEOTECHNICAL REPORT ....~.,.........+.<'v..~_ i ", f' r" d , il 11'\ P d F D d Rh d R Iph )1 : ,. Ii \ repare or aye an on a a , ! / (--'---..----'.-..'.'1: I I March 29, 2004 I! 1\' \ 1 i ! HI U! JUL 26 11M ll~,i, For ~:X~~1~bed as I. Lj[frE~iG' CDU_") ..1 Sections 14,15, Township 25 North, Range 2 West, M~~' OF ~.O;ylv:UN: f '( Cl \CLOFf.!Ef:..:...: Jefferson County, Washington Prepared by NTI Engineering and Surveying 717 S. Peabody Street Port Angeles, Washington 98362 Phone 360-452-8491 Fax 360-452-8498 Web Site www.nti4u.com E-mail info@nti4u.com I I I I I, I. I~ I I I I I I' I I I I I I " It NT' NORTHWESTERN TERRITORIES, INC. A JLS GROUP COMPANY 717 SOUTH PEABODY STREET, PORT ANGELES, WA 98382 Engineers Land Surveyors Geologists Construction Inspection MBterials Testing (360) 452-8491 FAX 452,.8498 www.nti4u.com E-MaH: info@rrti4u.com JI.S GROUP, INC. Geotechnical Report Tax # 502151017 March 29, 2004 Dave and Rhonda Ralph 13510 SE 301 st Street Aubum,WA 98092 Subject: Geotechnical Report for Tax #502151017 located in Sections 14,15, Township, 25 North, Range 2 West, W.M., Jefferson County, WA Dear Mr. AndMrs. Ralph: Background At your request, Bill Payton, Engineering Geologist with NTI Engineering and Surveying (NTI) met with you at the above referenced location on March:17, 2004 to Conduct a bluff stability inspection. The purpose of this inspection was to examine the manne bluff at the subject site by visual means in order to determine the relative stability of the bluff and make recommendations in regards to the proposed future construction of a single family residence, Site Description The subject Waterfront property is located at 372 Rhododendron 'lane at Slack ,Point south of Srinnon. The property overlooks Hood Canal to the east and is bounded on the, north and south by residential property (Figures 1 and 2). ' , ' Existing developments to the property include two homes (Photo 1), a shed, driveway, beach access stairs and other associated improvements. It is'our understanding 'that future plans call for the removaVrelocatiQn of the existing homes and the construction of a new single-tamily residence on the property. The upland portion of the property is mixedwooded and open. Thewoodeclareas consist of young to mature native trees and brush, while the open areas are predominantly grass' (Photo 2). The existing cleared home site area extends to the edge of the bluff. The topography of the upland slopes gently east toward the bluff at about 4 degrees. The bluff atthe property is about 35 feet high with an average slope angle of about 45 degrees, with some areas steeper (Photo 3). The bluff is mostly vegetated with brush and some trees, most of which have been topped. Some of the trees have curved trunks, indicating'that shallow down slope creep of the surface soils is occurring. There is a trail and stalrsthatlead down the bluff to the' beach and soils exposed in cuts along the trail are standing vertical in some areas (Photo 4)~ The toe of the bluff is undercut indicating that periodic high tides or storm waves have ' come in contact with the toe of the bluff; however, no fresh sloughing was noticed (PhotoS), There'are logs on the beach. These beach logs have ,a tendency te; a,ct as energy dissipaters for 1 . I I I I I I I I I I I I I I I I I I I waves and thus are beneficial to the bluff. The beach is covered with large gravel and cobbles, which helps reduce erosion from wave action and long shore currents (Photo 6). Also, the property is situated in a cove, which helps protect the bluff from wave erosion. No springs or seeps were noticed on the bluff face and no ,evidence of recent slides was noticed, although there was eyidence of erosion on the bluff face from inadequate runoff control from the upland. Site Geology The Washington State ,Department of Ecology's Coastal Zone Atlas maps the soils in the area of the subject property asVa~honlodgment till (Qvt1). This soil is described as consisting mostly a compact mixture of boulder to sand ,size particles with some silt 'and clay. The Atlas lists these soils as excellent for foundation stability, good for seismicstability,aod that that they · stand in steep natural and/or cut slopes for long periods. The Atlas ,maps the stability of the bluff as Stable (See Appendix). " The Oepartm~nt of Ecology's "Geology and Ground-Water Resources of Eastern Jefferson County, Washington" maps the soils in the area of the subject property as Lodgmenttill (Qvt): ; boulders, cobbles anci pebbles in a matrix of sand, silt and clay; a compact and unsorted mixture (See Appendix), , , , According to the SoU Survey of Jefferson County Area, Washington (United States Department of Agriculture. 1975), the subject site is in an 'area mapped as the Olete-Hoodsport complex (OpO) or the Hoodsport very gravelly sandy loam (HoC). TheOlete soil formed in weathered' basalt and the Hoodsport soil formed in glacial till and has a seasonal perched water table at a depth of 20" -36" (se~ Appendix). Visual observations made at the site indicate that the bluff is composed of compact glacial till (Photo 4). ' Conclusions and Recommendations While this report cannot guarantee that a slide will not occur at the subject property, the bluff at , the subject property appears to be grossly stable at present with' no evidence of recent slide activity. No springs or seeps were observed on, the bluff, The bluff soils are capable of standing in steep slopes for long periods as mentioned in the Coastal Zone Atlas and observed 'on site~ Occasional storm waves and high tides willcontacUhe lower bluff, causing erosion. PeriQdic slougrnng may'result from the toe of the bluff being undercut and oversteepened by this wave' , erosion. Based upon our investigation, we recommend that the setback distance from the top of the bluff to the proposed house be set at no less than 35 feet. This distance should provide an adequate buffer for at lec:ist an economic life of 1 00 'Years for the house, assuming ,an average rate of bluff recession of 0.2'/year. , ' The following. recommendations should also be considered,with regards to the proposal: 1. It will be necessary to maintain ground cover in order ~o reduce erosion from surface runoff. Any bare areas that develop should be revegetated. Native deep-rooted ' vegetation that re~uires little or no irrigation would be the most beneficial. Please consuJt the enclosed publications for further information. 2. Vegetation on the bluff face provides stabilization to the bluff face soils and helps remove water from the soil. Existing established vegetation should be left in as natural 2 . I I I I I I I I~ , I I I I 1 1 I I, 1 I I state as possible, If a better view is desired, minor thinning and pruning should be done in such a way th~t minimizes disturbance to the soil and root zone and that insures the continued health of the vegetation, 3. Heavy irrigation or other activities that would contribute large quantities of water to the , soil should be avoided. 4. Surface runoff from hard surfaces such as roofs, driveways, walkways and patios should be controlled and routed to a dfainagecontrol device such' that surface water discharge to adjacent properties does not significantly exceed predevelopm~nt conditions~Based on the 2000. Department of Ecology guidelines, as adopted by Jefferson County; itseems that a tight line to the base of the bluff without detention would provide the ~st solution, given the very slow permeabilitY,of the site soils as mentioned by the Soil Survey. ' ' 5. ,Silt fences or other sediment control devices may be needed during construction such , that sedimentation to adjacent properties does not significantlyexeeed predevelopmentconditions, , , , ' , , 6. Drainage control devices should be maintained in good working arOOr and inspected at least ancea year. 7. An engineered drainage and erosion control plan will be required by Jefferson County and should be developed for this property to address items 4, S, and 6 above. NTI can ' perform this task .if requested. 8. Weailticipate that improvements and maintenance to the existing trail down the face of the bluff would, not significantly decrease slope stability. The trail,'should be ' maintained such that erosion of the bluff is not exacerbated. It may be beneficial to consult someone who specializes in this type of construction~ Based on the findings, recommendations and limitations of this report: 1. There should be minimal landslide hazard as suggested ,by a lack of evidence of recent landslide activity in the vicinity in the past. ' 2. Observations of slope stability indicate that the proposal should not be subject to risk of landslide under the current conditions that exist at the,site. 3. The proposal should not increase surface water discharge or sedimentation to adjacent propert~s beyond predevelopment conditions. 4. The proposal should not decrease slope stability on adjacent properties. 5. The proposal should be stable under normal geologic conditions. , . ' For further information please review the three publications (included with the original of this report) publish~by the Washington State Department of Ecology (DOE) entitled: "Slope Stabilization and Erosion Control Using Vegetation", "Vegetation Management: A Guide for Puget Sound Bluff Property Owners" and "Surface Water and Groundwater on Coastal Bluffs". These publications can also be viewed on the DOE website at: htto:llwww.ecv'wa,gov/biblio/sea.html ,under the, 199.3 and t994 year heading, The DOE-website ' 3 . I I' I I I I I I I I I I I I I I I I I also contains additional useful information regarding slope stability and site development; this reference is highly'recommended. Limitations This report has been prepared for your exclusive use in conjunction with the above referenced project. The reporthas not been preparedfpr u~e by others or for other locations. It may be used for other purposes only with the expressed written permission of the Engineer. ' Within the limits of scop~,schedule and budget, this report was prepared in general accordance with accepted professional engineering and geological principles and practices in this or similar localities 'at the time the report was prepared. No other warranty, expressed or implied, is made as to the conclusions and professional advice inCluded in this report. , The observations, conClusions and recommendations presented in'this report were based on our visual observations of the subje~tproperty at the time of our site ,visit; no Jaboratory tests' were performed. Soil and geologic conditions ~n vary significantly between testholes and/or , surface outcrops. If there'is a ,substantial lapse of time, conditions at the site have cha"ged or appear differentthanthose described, in this report, we should be 'contacted and retained to evaluate the changed conditions, and make modifications to our report if necessary. ' , Sincerely, ' NORTHWESTERN TERRITORIES, INC. .~~ RobertA. Leach,P;E., MBA Principal Engineer 1213012OO4 I EXPIRES , //} /- --~ ." /J ; / 1--_ ~ .~/-)' 'l ,'~ t.:;g..'_"L' ,"-, , ~,......~~'.~ - Bill Payton, LE.G. Engineering Geologist Willl.me. PaytonJr~ I ExpireS 11/06104 I G:\Gen\BiU\Reports\RALD0401-01.b1uff stability. 14. 15(2f>.2).Black PoInlBrlnnon.doc 4 I I I I I I I I I I I I I I I I I I I . I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I r I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I .; I fl Seak I ~24.(lO(l . I )'hles '-'.:...-..~._.....JA ~ IJ~ ~~ ~d~ '," "" I ,....... ~.- -, ....~..'...~, ..~..,.;..., "~'!':,""-~ ___...,............' ...... ..-~.... v... _':'.....,..,......;~l_\~_....'foa ,",- _N"'........._"'.~_..___..,._ ..-... ~4.."""'.t.,.._.........,,,...~'V_, =-,,~:'=~~..:=..:::.=.r~ ~ .............,.......,................ I I ~.... 1-,' ".-.... J . ..,~,............ _____ II- - I I I I I I ), I I Coastal Zone Atlas SIoDe Stability MaD I I I I I I I I I @ JEFFERSON COUNTY AREJ N I ~" 1 I .!! % 1; ~ II 8 on i i It. I I I 1 II! i J : I ! j II: it . it l J Iii II I JI I II i 0 N ; . 0 0" . ':" 'i A- . Ii f. ! t i 8 i i I . ::If r~ . - : 0 i J ~ ! - ~i fA' N ! i ~ I l! 8 . .. . .. f~ f') .... '... ;... , c , .. , - .... !... r; i l! :i : J W .. I I~- I I . I I I I I I I I I I I I I : , I I I , / I I / / '/ \,,/UI SECTIONS AND EXPLANATION, SCALE, BASE DATA, AND INDEX MAPS. 1_" 1->.., .::A,. A )k~XI P"\ .,'1: ~' <"'Jp S\.?~..)~"C~t jJ"c:'Jf.l.:.'--h.,. I , i r;"" J;..;..,; .. :'t"" N , STATE OF WASHINGTON DEPARTMENT OF ECOLOGY SCALE l:~ GEOLOGIC MAP OF EASTERN JEFFERSON OOUNT~ WASHINGTON /:~.z .Yot:J Scale: I-: 418,900 (4000 f.er per inch) . T Dote: NOVEMBER 1980 -----~...--_._..._----~_._............ &aJ )- ~ 0::, 0 Ol( CD ~ ~ l&I I LL~! 65xK)8 Yrs. I I I I I I I I I I I I I I I I I I I ~ 4 ~ l&I ~ o au ~ cl (3 Ol( I . I JlI04 Yrs. ~ ~ ~ CD II.l ffi (.) o I- (I) l&I ..J Q. I .. ~. 2X'o4Yts. tu>> f!;, (I) ! m!; ~~(.) &1.-:5 ~~I - 2xlO8 Yn. . / ; . GEOLOGIC EXPLANATION AlatQlaclal 8Id1mentI: Recent stream, Jake,mcII"8IltlWClmP, lagoon, beach,and eolian deposita of grovel, sand, sUt, cloy,and pili'. Unit ,leld. lIIaclll q~tles of water to driven weill; stream..... In hydraulic COIItinultJ . with streamlor In combInGtlon with reIIIonal ......... JiIId moderate to larga quant"'" to ..". diameter ...... Waf... quality prob..... mGJ ocCur because of orgQnIc materials ouocIatecI witlt depNltton ond/or proximity of man related contaminant.. Recessional outWCII'nnd Ice-contact stratified *1ft: deItoa,allwiaI fanI, channel filii, k....~ kame terrOCll,.... and other 1Id1""'" bocIIeI cIepoelted by ...... from ncedlnt ice lobes of tbe flaler 6laciation. Includes ... ablation till. Couilts prllIMIrily of growl witlt 101M 1CIAd, silt, and clay; .....Iy unconsolidated. UnIt,.... _II to kwgequantitiet of ground, water .... it occurs In IUfficIInt tb..... below lObated.... Lodgment till: I;Iou1den, c:obbIeI Gnd pebbles in nialrix of tiand', silt GRd cIoJ; a compact and unsorted mixture. Generally ClJIVeNd by a few fMt of I'ICe8- .ional drift cir HoIocInIlldlmenta. Includ..... Ever8CID gloolamarlne drift. Generall, unit Is Impermeable but ... ...... of .... and ..... which may yield small quantitiel of wat... i ...... _ an aqutc.... and as impermeable borrIIr below perched water. AdVance out....: grove' ond sand with 101M tilt and clay; wll' yield moderate to larQI quemtltles of.......... CJI'CMI and .nd underlie 20M of ICItUrGtion. Undifferentiated glacial, fluvial, glaci0fiuvial, lacuetriM,and tIOcio1ocuatriM ......: Includ" IIdIIMnta resultlno' ..... pre-FraIIr 6tac1otlDftl (Po....ion Drift, Double Bluff Drift), interglllclatJoil. ( WNdbeJ YcnNItion), and achance outwash sancia of the Fraser 81ac1at1on. The............. of the prI:-FJ1IMr ...... are of VGrJIng .....llIl1t' and 0....1 ......... ;cr-~r;i~'7~~mt:~-c. ="~i.--~~"" ..-. - - -- .. -..-.-. SedImentary rocb t undlff....tlotecl: nud.... t siltstone, IGl'lClltofte t congIaIiteratei generall, .lmpermeable and""" liftle or no.... Volcanics, undifferentiated: basalt flows predominate with 101II mud flows (CreIcent Formation); generally Impemeable except bel ~..n flows and along Jointa and fractures i yield IInGII to mocler41e ...... of wat.... I I I I I I I I I I I I I I I I I I I 34 SOIL SURVEY slow to ponded, and the hazard of water erosion is slight or nonexistent. A seasonal water table is at a. depth of 0 to 12 inches. This soil is used mainly for grol\ing pasture and truck crops. Capability unit IIw-2j not assigned to a woodland group. Olete Series The Olete series consists of well-drained, very gravelly soils underlain by basalt bedrock at a depth of 20 to 30 inches. These soils are on rough, broken uplands, Slopes range from 0 to 90 percent. Elevation ranges from slightly above sea level to about 1,000 feet. These soils formed in weathered basalt under Dougla&-fir, western redcedar, red alder, madrone, rhododendron, and salal. Annual precipita- tion is about 28 to 32 inches. The average annual aU: tempera- ture is OOOF. The above an growing season ranges from about 190 to 230 days, and the above 28~ growing season ranges from about 200 to 260 days. These soils are associated. with Ahl, Alderwood, Clallam, Everett, Grove, Hoodsport, and Triton soils. In a representative profile the upper 3 inches of tM soil is dark reddish-brown very gravelly silt loam. Below this, to a depth of 18 inches, is dusky-red very gravelly silt loam. Beneath this, and extending to a depth of 24 inches, is weak-red very stony silt loam that is 80 percent or more coarse basalt gravel and stones. This material is underlain by basalt bedrock, which is. generally fractured. Rounded pebbles and angular basalt stones are scattered t1ll'ougbout these soils. Olete soils are almost entirely wooded, but a few acres are used for rural homesites. Olete very gravelly silt loam, 0 to 30 percent slopes (OeD).-This nearly level to hilly soil is in areas of upland slopes. Most slopes range from 10 to 20 percent. /--- Representative profile 0.5 mile south of Knapp farm and 0,25 mile west of State Highway 9E; on l~~ road 150 yards southwest of basalt rock quarry in SW7.(.NE~SW~ sec. 19, T. 28 N., R. 1 E.: 01-2 inches to 1 inch, Jeav~ needles, and twip. 00-1 inch to 0. dec:oui~ leaves, needles, ana t.wip. B21ir-O to 3 inches, cWk nddiBh-brown (2.6YR 3/4) ywy p-aveUy silt loam, weak red (2.SYR 6/2) dry; moderate, V!'IY fine .ad fine, granular struct.unl; bud, very friable, slightly sUeky, nonplMUci many fine and medium roots; 55 percent augular ~l,es; slightly acid; abrupt, wavy boundary. (2 to 6 inches thick) B22ir-3 to 18 inches, dusky-red (2.5YR 3/2) Vf!IY. ~ftl!y silt loam, pale red (2.6YR 6/2) dzy; massive i hard, friable, sliPtJy sticky, n~!' 'c;.common ~ roots; 65 ~t aoiu1&r .....t"bl~i. : tJy acid; poadual, irregular bouiidary. (10 to 16 ~ches wcti 0-18 to 24 in weak-red (2.SYR 4/2) very atony silt loam, ~e red (2.6 . 6/2) dry; massive; hard, f~ Rli&h!'lY sticky, non~; 80 ~t coarse frapHlllts; slightJy acid; clear, irreaUlar boundary. (2 to 8 inches U1iek) R-24 inches, bualt. beclrocL Depth to basalt bedrock l"8DPl from 20 to 30 inebes. The B horiZODll range from dark nddish brown to dusky red. Graftl and stones' in the B horUon& ranp from 50 to 80 ~" In the C horiaon 1A!xture is silt loam or loun. This borisoD .16 to 90 pereent coarse gravel and stones. Basalt stOIIes and cobbles are in the A and B horizons in plaees. ' Included '\lith this soil in mapping are small areas of Rock outcrop and shallow soils, This soil is well drained. Permeability is moderate. Roots penetrate to a depth of 20 to 30 inches, This soil holds about 2 to 4 inches of water available for plants. Runoff is slow to medium, and the hazard of water erosion is slight to moder- ate. This soil is used mainly for production of trees and/for '\lildlife habitat and recreation areas. Capability unit VIe-I; woodland group 3d2. Olete very INveUy silt loam, 30 to 50 percent slopes (OeE).-This steep soil is on upland slopes in rough, broken country that has basalt outcrops and escarpments present in places. Runoft is rapid, and the hazard of water erosion is severe. This soil is used for production of trees and for wildlife habitat and recreation areas. Capability unit VIe-I; wood- land group 3d2. Olete-A1derwood eompla, 0 to 30 percent slopes (OID).-This 1J)8.pping unit is made up of about 60 percent Olete very gravelly silt loam, 0 to 30 percent slopes, and 40 percent Alderwood gravelly sandy loam, 0 to 15 percent slopes. The Olete soil is rolliDg to hilly, and. the Alderwood soil is undu1a~ to gently rolling. The soils of this complex are used mostly for production of trees and for wildlife habitat and' recreation areas. Small areas of the Aldenvood soil are used as permanent and sum- mer rural homesites and for growing pasture, hay, berries, fruit, and vegetables. Capabilit.y unit VIe-I; woodland group 3d2. Olete-ClaIIam eomplex, 0 to 30 pereent slopes (OmD).-This mapping unit is made up of about 60 percent Olete very gravelly silt loam, 0 to 30 percent slopes, and 40 percent ClalIam gravelly sandy loam, 0 to 15 percent slopes, The Olete soil is rolling to billy, and the Clallam soil is un- dulating to gently rolling. The soils of this complex are used mostly for production of trees and for wildlife habitat and recreation areas. Small areas of the Clallam soils are used for permanent and sum- mer rural homesites and for growing pasture, hay, vegetables, fruit, and berries. Capability unit VIe-I; woodland group 3d2. Olete-Hoodsport eomplex, 0 to 30 percent slopes .... (OpD).-This mapping unit is made up of about eqUal proportions of 01ete very gravelly silt loam, 0 to 30 percent slopes, and Hoodsport. very gravelly sandy loam, 0 to 15 percent slopes. The Oleteaoil is rolling to hilly, and the Hoods- port soil is undulating to gently rolling. The soils of this complex are used mainly for production of trees and for wildlife habitat and recreation areas. Cap- ability unit VIe-I; woodland group 3d2. Olete-Rock outcrop eomp1es, 50 to 90 percent slopes (OrF).-This mapping unit 18 made up of about 50 to 70 percent of an Olete very gravelly silt loam and 30 to 50 percent basalt stones and Rock outcrop. Runoff is very rapid, and the hazard of water erosion is very severe. This complex is used mainly for production of . trees and for "i]dlife habitat and recreation areas, Capability unit VIIs-I; woodland group 3d2. Phelan Series The Phelan series consists of moderately well drained, gravelly soils that have a very slowly permeable cemented. layer at a depth of 10 to 20 inches. The soils formed in glacial till on stream and river valley side slopes in the western Olympic foothill areas. Slopes range from 30 to 80 percent. Elevation ranges f~m about 200 to 1,000 feet. Native vegeta- I I I I I I I I I I I I I I I I I I I 24 SOIL SURVEY All-O to 4 inches, dark reddish-brown (5YR 3/2) gravelly silt loam, reddish gray (6YR 6/2) ~; ~ medimn and coane, gnDuWaVuetUre;8liIhdY liard, friable, slightly stieky, sli&btly plastic; many fiDe. Diedium, and coarae roots; 30 ~ cent rounded ~ inc1~ IlOII1e cobbles; etroDgly acid; clear, wavy bOundary. (3 to 6 mches thick) Al2-4 to 8 mebes, dark ~y (5YR 4./2) craveUy aik loam. light. reddish brown = 6/3) dry; moiIente; fine and medium, .aubangular st.rucmre; hard, friabJe,' 8&icky, ~o; manyfioe,mediWn, and couse roots; 35. pIlI!:l8Ilt rounded ~ includina BOme cobbles; stroDgly acid; clear, wavy boUndary. (3 to I iDChes t.hick) , B21-8 to 12 inches, dark-brown (7.5YR 4/4.) .....vellyaik loam. pink (7.6YR 7/4) dry; OOIIlmon, fine aDd mediUm. diosLinct ,yellowish-nld (oYR 6/6) mottles; moderate, medlum and coarse, subangular blocky aVuctunl. hard, friable, 8&icky plastic; slightly smeary fcie1; maIlY ~ ~ and ~ roots; 36 ~t. rouDded ~ inchxIiDc IIODle eobb1ee; strongly aCid; 1J'lIdual,~boundary. (3 to 6 iDehes thick) B22-12 to 16. inebes, 8 own (7.&Yll 5/6) .....~ silt. loam, reddish ~ (7.6 7/6) dry; maDY, JDediuni and coane, faint dUk-brown (7.5YR 4/4) moUIe8; weak, medium and eoaree, aubangular blocky atructunl; liard friable, sticky, nJutic; s1ightly smeary feel; common fiDe;;;d medimn roots; S5 percent roUnded ~ incluclimr: some cobbles; mediwn acid; 1J'lIduaJ, wavy boaDduy. (3 to f inebee thiek) :823-16 to 22 inches. ~wn (7.5YR 5/8) cn;,.elly silty clay loam, reddish yelloW (7.IYR 8/6) dryi. few, fiDe, faint. darlt-b1'01l'l1 (7.IYR 4/4) mottles; weak, meaium and coene, prismatic and weak, .....,. fiDe and fine, 8Ubucular blocky strueture; bard, friable, sticky, pJaatie; ~. !eel; common fine and medium roots; 30 peramt IOUJIded plbbltII and about 10 ~t smaJJ and medium' cobbles; medium acid; clear, smooth boundary. (I to 7 iDehea thiek) 01-22 to 29 iacbe8; Dal&-browD (IOn 0/3) &f&~1 silty clay Joem, white (Iom 8/2) dry; JDUIift; ftI)' bard. firm, 8t.ick;Y, ~tic; few line roots; 30 percent. rouocled pebbles; medimn acid: JD'8d~ wavy~. (5 to 8 incbes thick) C2sim-2if to 40 m~ ~ (IOn 8/3), weaklyeemeoted paYelly silty,: clay ~ wJme (lOYR 8/2) dryi JIUISlIiye; ex- tremelY hard, ext.nmeJy firm; few fine roots m u~ few inches' 30 ~t rounded ~; medium acid' d.iIfuse, smooth bouDdary. (9 to 1-4 inChes thick) , C3-4O inches, "'!!'Y compaci pave1ly silty eIay loam gJaciaJ till. (Many feet thiCk) The A horizons ani dark reddish-brown 01' dark reddish-p-ay to dark-brown KJ'IlwlJy loam 01' ~ aili Jo.m. The B horiaOoS ani stroDg~ darIt-brcnm , and dark yeDowish-brown .....veIIy silt loam, ....v;,uy Joem, paftlly silty clay loam, or graveDy clay loam. The A and B hOrUonI ani 25 to 35 pereent. gravel and eobbJes throuahoot. Tbe 01 horisoo is licbt. brownish lP'&y ~ pale brown. The C2aim horizon is pale brown to 01= Reaction 1'lUlP8 from W!lY stzoocly acid to medium acid out. the profile. Included with this soll in mapping ale small a:re&8 of somewhat excessively drained soils. This soil is mcxlerately well drained. Penneability is mcxlerate above the cemented layer. Roots penetrate to the cemented layer. This soil holds about 3 to 6 inches of water available for plants. Runoff is slow to medium, and the hazard of water erosion is slight to moderate. A perehed water table is on top of the cemented layer during the rainy season. This soll is used mainly for production of trees and for wildlife habitat, recreation areas, and rural homesites. Capa- bility unit VIe-I; woodland group 3dI. ~oko gnn'elly silt loam, 15 to 30 penent slopes (HKO).-This soil is generally along the mountain foothill toe slopes in close association with Klone soils. On the upper part of the slopes the soil is ~ to 30 inches deep to the cemented layer. On the lower part of the slopes it is 30 to 40 inches deep to this layer. Runoff is medium to rapid, and the basard of water erosion is mcxlerate to severe. This soil is used mainly for production of trees and for wildlife habitat and recreation areas. Capability unit VIe-I; woodland group 3dl, Hoko gravelly silt loam, 30 to SO pereent alopes (HKE).-This soil is on the higher mountain foothills and along the stream. and river valley sidewalls. The steeper areas of these soils are generally 20 to 24 inches deep to the cemented layer. The less steep areas are 24 to S6inches deep to this layer. , Included \\ith this soil in mapping are areas where the surface layer is ftagy silty clay loam. Runofiis rapid, and the huard of water erosion is severe. This soil is used mainly for production of trees and for wild- life habitat. and recreation a:re&8. Capability unit VIe-I; woodland group 3dl. Hoko-Snahopish aseociatlon, hilly (HLE).-Tbis ~ sociation consists of about 65 percent Halto gravelly silt loam, 15 to 30 percent slopes, and about 35 percent 8nahop.isl1 silty clay loam, 0 to 00 percent slopes. The Hoko soil is mostly hilly, and the Snahopish soil is mostly nearly level to gently rolling. . The soils of this association 8I'e used mainly for production of trees and for wildlife habitat and recreation. areu. Capa- bility unit VIe-I; woodJand groUp 3d1. Hoko-Tealwhit auoeiadon, gently J'OlIIq (HMC).- This association conaiats fA about 70 pereent Hoko gravelly silt loam, 0 to 15 percent slopes, and about 30 percent Tealwbit silty clay loam, 0 to 8 ~t slopes. The Hoko BOil is mostly gently rollinI, and the Tealwhit soil is mostly nearly level. This association is used mainly for production of trees and for wildlife habitat and recreation areas. Capability unit VIe-I; woodland group 3d1. Hoko Gravelly Silt Loam, Wet Variant Hoko gravelly Silt loam, wet variant, 0 to 8 percent slopes (HNB) is a nearly level to gently sloping soil of the g1acia1 terraces. The upper 5 to 7 inches of the soil is gravelly silt loam con~ numerous ~~ reddish-brown ~- nese concretions. Beneath this IS a layer 2 to 4 mches thick that has brown and very dark ~yish-brown mottles. This layer is underlain by light grayish-brown cobbly clay loam that has dark reddiah-brown mottles and a few concretioDS. The cemented layer, at a depth of 8 to 24 inches, is mottled and is 40 to '60 pereent gravel and cobbles. All horisons are very strongly acid. This BOll is poorly drained. It holds about 2 to 4 inches of water available for plants. Runofi is slow, and the hazard of water erosion is slight. , This soll is used mainly for production of trees and for l\i1dlife habitat and recreation areas. Capability unit Vlw-l; woodland group 3wl. @oodsport Seri~ The Hoodsport series consists of mcxlerately well drained soils that have a very slowly permeable cemented layer at a depth of 20 to 36 inches. They are on terraces adjacent to 'the steep, rough, broken mountain foothills. Slopes range from 0 to 30 percent. Elevation ranges from slightly above sea level to 500 feet. These soils formed in glacial till under western redcedal', western hemlock, red a1der, wild cherry, madrone, rhododendron, and salal. Annual precipitation ranges from 55 to 65 inches. The average annual air tempera- ~. I ture is about 5OoF. The above 320F growing season ranges from about 150 to 200 days, and the above 280F growing I season ranges from about 200 to 240 days. These soils are associated mainly with Ahl, Grove, Lyst&ir, 01ete, and Triton soils. In a representativ~ profile about 3 inches of needles, I leaves, bark, and humus cover the surface. The upper 17 inches of the soil is reddish-brown very gravelly sandy loam. Below this, to a depth of 28 inches, is dark yellowish-bl'Own gravelly sandy loam. Beneath this is a very dark gray ee- I mented layer. Glacial cobbles and stones are present on the surface and throughout the soil, Nearly all of the B~ soils are wooded. Besides production of trees, another unportant use is for rural wood- I land homesites. ~ Hoodsport verysraYelly sandy loam, 0 to IS pereent slopes (HoC).-Tbis nearly level to rolling soil is on glacial terraces. In most places slopes range from 6 to 12 percent. Representative profile 60 feet west of U.S. Highway 101 and 120 yards south and 120 yards west of SE3-(SW3-( corner sec. 29, T. 25 N., R. 2 W.: OI-2~ inches to 1 inch, needles, leaves. wood, and bark. 02-1 moh to 0, black. (5YR 2/1) ~y decomposed needles, leav~ ~ood, aDd bark; atrongly aeicl; abrupt, smooth bouDd- . Oi to 2 inehes thick) B21::O to 6 inches. reddish-bl'Own (5YR 4/4) very graftlly sandy loam, reddish brown (5YR 5/4) dryj weak, medium and coanse, granular Ilt.nJcture; soft, "Iety friable, noDStieky, non~tic. many roots. 60 pereent gravel; strongly acid' gradUal, ":avy ~ (4 to 8 incheS thick) , B22ir-6 to 17 in~ nldmsh-brown (5YR 4/4.) very gra.,.,tly sandy loam; reddish brown (5YR 5/4) dry; weak. fine ana medium, subanpJar blocky structure; 80ft, very friable, non- sticky, nooJ)lastic; many roow; 60 pereent gravel; strongly acid; gradual, wavy bouDdary. (10 to 18 incheS thick) CI-17 t.o 28 inches, cJark._ye1Jowish-brown (10YR 4/4) very gravelly sandy loam. yelknrillh brown (10YR 5/8) dry; JWI&- siTe; sOft, very friable, DODBtit;ky, nonplastic; many rooWj 70 ~t pvel; atnmpy acid; &bmpt, smooth bOundary. (6 to 12 inches thick) C2sim-28 to 45 incbe8, dvlt-py (SY 4/1) very gravelly sandy loam, gray (5'ft 5/1) ~; 1D8IIlive; extreme1)r hard, eit.nme& finn; stronglY. cemented; 55 percent gravel; atrOngJy aeid; diff~ smooth boundary. (14 to 20 inches thick) C3-45 inches, very compact, wealdy cemented glacial tilL (Many feet thick) The B horizons are darlt Jeddish brown to reddish brown. The B and C horizons AnI, 50 to 70 ~t Jl'&vel and -cobbles. The C2sim horizon is graYl. dark -y, or olive gray and many feet. thick. This soil is medium ae1ij-or 8trooIIY acid throuchoOt the profile. JEFFERSON COUNTY AREA, WASHINGTON 25 The soil is moderately well drained. Permeability is moder- ately rapid above the cemented layer. Roots penetrate to a depth of 20 to 36 inches. This soil holds 2 to 4: inches of water available for plants. RunoB is slow to medium, and the hazard of water erosion is slight to moderate. A perched water table is on top of the cemented layer during the rainy season. . This soil is used mainll for producing trees and for ",ild- life habitat and recreation areas, Capability unit VIe-I; woodland group 3d2. ' Hoodsport very ~vel1y sandy loam, 15 to 30 pereent slopes (HoD).- This hilly soil is on glacial terraces. In the higher areas the soil is generally 20 to 24: inches deep to the cemented layer, a.nd in t.he lower areas it is 24: to 36 inches deep to this layer. Included with this soil in mapping are small areas having large basalt boulders and basalt bedrock outcrops. Runoff is medium, and the hazard of water erosion is moderate. This soil is used mainly for producing trees and for ",ildlife habitat and recreation areas. Capability unit VIe-I; woodland group 3d2. Hoodsport gravelly loam, 0 to IS percent slopes (HpC).-This nearly level to rollinc soil is in small, isolated areas 'on glacial terrace ridgetops. Elevation ranges from 300 to 500 feet. The upper 12 inches or more is dark reddish- brown gravelly loam. Reaction is slightly acid to medium acid. Permeability is moderate above tbe cemented layer. This soil holds about 3 to 5 inches of water available for plants. This soU is used mainly for production of trees for wildlife habitat and recreation areas~ Capability unit IVe-1; woodland group 3<12. Hoodsport-Grove very sraveUy sandy loams, 0 to 30 pereent slopes (HrD).-This mapping unit consists of about equal proportions of Hoodsport very gravelly sandy loam, 0 to 15 percent slopes, and Grove very gravelly loamy sand, 15 to 30 percent slopes. The Hoodsport soU is mostly undulating to gently rolling, and the Grove soil is mostly hilly. This complex is used mainly for production of trees and for \\ildlife habitat and recreation areas. Capability unit VIe-I; woodland group 3d2. Doypus Series The Hoypus series consists of somewhat excessively drained, gravelly soils. These soils formed in glacial out- \\'B8h on terraces. Slopes range from 0 to 50 percent. Eleva- tion ranges from 100 to 500 feet. Native vegetation consists mainly of Douglas-fir, western hemlock, western redcedar, madrone, rhododendron, salal, Oregon grape, huckleberry, and bracken. Annual precipitation ranges from 18 to 30 inches. The average annual air temperature is about OOOF. The above 3n gro\\ing season rangeS from 200 to 260 days, and the above 2gOF growing season ranges from 260 to 300 days. These soils are 8880ciated mainly with Agnew, Alderwood, CaMoIary, Carlsborg, Clallam, Dick, Everett, Kitsap, and Sinclair soils. In a representative profile in a wooded area, about 3 inches of needles, leaves, twigs, and decomposing organic matter cover the surface. The upper 10 inches of the soil is dark-gray and dark-brown gravelly loamy sand. Below this, to a depth of 26 inches, is dark yeIIowish-brown gravelly loamy sand. The underlying material consists of two dark grayish-brown layers. The upper layer, between depths of 26 and 44 inches, is gravelly loamy sand, and the lower layer, between depths of 44 and 60 inches, is very graveny sand. Most of the Hoypus soils are wooded. Besides production of trees, other important uses are limited pasture, home gardens, and homesites. , Hon-us paveU110amy sand, 0 to IS percent slopes (HuC).-This nearly level soU is on rolling glacial moraine terraces. In most places slopes range from 6 to 12 percent. Representative profile on south side of road in SW~E~E3-( see. 16, T. 26 N., R. 1 W.: 01-3 inehes to 1 inch, needle;.,leaves.~and fraamenta of 'II'OOd. 02-1 inch to 0, b1ack (5YR 2/1)" Y. cIecoiRpaIed ol'pllic matter from needles, leaves, and fratpneDts of Wood; atrongly,acid; abmpt, wavy boundary; ~ to 1~ iDches thick) A2-o to 1~ inches, di.rk-pay (tOYR 4/1) gravelly loamy sand, gray (IOYR 6fl) dry; weak, fine, granular stmcture; soft,