SfATIS OF CALIFORNIA~ THE RESOURCES AGENCY

George Deukmejian :IDaDNDx;~ •• Governor

OEPARTMENT Of CONSERVATION

DIVISION OF MINES AND GEOLOGY SAN FRANCISCO DISTRICT OFFICE

AP /l,87 FERRY BUllDING

SAN FRANCISCO, CA 94111

{Phone 41.s-557-0633)

June 13, 1984

County Engineer-Facilities Engineering Geology Section - Room 403-A 550 South Vermont Avenue Los Angeles, CA 90020

Attention: Art Keene

Dear Art:

we are placing on open file .the following reports, reviewed and approved by the County of Los Angeles in compliance with the Alquist-Pdolo Special Studies Zones Act:

Fault study, 5641 Elizabeth Lake Road, Leona Valley, CA; by M,V. Srnith1 July 27, 1979; with update of January 27, 1984 by Buena Engineers~

Geology report, Ta>< Parcel 3052-30-18 (35813 - 38th Street East -- 3746 ET-8), Palmdale, CA; by Buena Engineers, Inc.; May 4, 1984.

EWH:mc

cc: A-P file (2)

Sincerely yours,

Earl W. Hart Office of the State Geologist CEG. 935

ENUINEERING GEOLOGY SECTION 0 0 (213) 738-2161

Review of:

Action:

PLAN CHECK NO. OR DATE OF REPORT(SI

0Grading P.C. No_ IM'IB~ilding p_c_ No. 7hA1 OGeologic Sito Inspection Only P_C_ ~ ~Geologic Report Dated .L'J1LLy ~ flJ'± _ ------i)(lSoils Report Dated ____ __ .. _______ _ __ _

OGeology & Soils Report Dated ___ _

D Plan is geologically approved 0 Plan is not approved for reasons below

(&1Plan approved geologically subject to conditions below DSubrnit plans for recheck

DSec. 309 Code requirements met (not met)

OSec. 308(b) 3c & e code requirements met (not met)

Dist. Office ___ ~---F f¥ NF X SHEET I OF I

DISTRIBUTION: Z.Oi5t Engineer L Geologist _ Soils Engineer /- Geol. Sect. File _ Grading Section

--------·--____ .... __ _

(!) ·-r he.. c...01-1.s-u !fan T.s rcco,..,..,fl'le:.1-1.Jq,-h'on..s /1-'lUS f h~ /o //owed.

(?..)/he.- /oc.al-t'on co--1.d de/11-h of' -lovHda.I-/,,,.., e-X,;-4Va-//,,,..,_s

ff! us I ,be_ a I°/° ro vc:d .6 j ·-1-h e:.- c.o f.-1S' v If,,,..,_ -f..s I° ,., , <,,, Y' ro {1ovr-1'nJ or f/aGt';j,, f' s/-ee_/,

Prepared by

7t;iG30A - PS 12-83

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42326 - 101h STREET WEST • P.O. BOX 2866 • LANCASTER, CALIFORNIA 93534 • PHONE (805) 948-7538

May 4, 1984

Mr. Kar.l Brown 9457 Sandusky Arleta, CA 91331

Attention: Mr. Karl Brown

Subject: GEOLOGY IlliPORT Tax Parcel 3052-30-18 Los Angeles County, California

B-2179-LOl

Presented herewith is our Geology Report performed as authorized for the subject parcel located near PalmdaJ.e, Los Angeles County, California.

Recommendations for general site development with respect to ob­served site geologic conditions are included. The conclusions and recommendations conta.ined herein were based upon the applicable standards of our profession at the time this report was prepared. Copies are furnished only to provide the data which were gathered and which are summarized in the report.

This report completes our scope of services in accordance with our agreement dated April 6, 1984. Additional services which may be required, such as plan review and gradj.ng observation are additional services and will be billed according to the Fee Schedule in affect at the time the services are provided.

ENGINEERING OFFICES~

tlf.:l.D OFFICES:

VENTURA (8QS) S...2-6727

THOUSAND OAKS (805) '195-8484

SANTA BARBA.RA (li06) 96Q-i;J91,.

PALM SPRINGS (/14) 328-9131

LANCASTER (805) 948-7538

SAN LUIS OBISPO {805) 544-6187

I I I I I I I I I I I I I I I I I I I

Please contact the undersigned if there are any questions con­cerning this report or the recommendations included herein,

Respectfully submitted,

BUENA ENGINEERS, INC.

~J. Mark S. Spykerman R.G. #3800 E.G. #1174

MSS/MVS/sam

cc: 6 - Client l - file

#2~ith Vice President/Manager

BUENA ENGINEERS, INC_

I I I I I GEOLOGY REPORT

I TAX PARCEL 3052-30-18

I 35813 38th STREET EAST

I I.OS ANGEI.ES COUNTY, CAI.IFORNIA

I I I I

PREPARED FOR

MR. KARL BROWN

I I I I B-2179-LOl

I MAY 3, 1984

I I BUENA ENGINEERS, INC.

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TABLE OF CONTENTS

PAGE

INTRODUCTION ••••••••••••••••••••••••••••••••••••••••• 1 SITE DESCRIPTION ••••••••••••••••••••••••••••••••••••• 1 FIE:LD E)(!>LORl\.'l'ION •••••••••••••••••••••••••••••••••••• 2 GEOLOGIC SETTING ••••••••••••••••••••••••••••••••••••• 2 SI TE GEOLOGY ••••••••••••••••.•••••••••••••••••••••••• 3

Descriptive Geology ....•......•.............•..••. 3 Pliocene Anaverde Formation, Red Arkose (Tar) ..• 3 Quaternary 01der Alluvium (Qoa) ...........•..••. 4 Holocene Alluvi urn ( Qal) ..................•...••• 4 Residual Soil ( Qrs) .•.................••..•....• 4

Faults •.•••.......•..•.•....................•.•.•• 4 GEOLOGIC HAZARDS ••••••••••••••••.•••••••••••••••••••• 5

Faulting ..••.•..••...•.................•.•..•...•• 5 Ground Shaking ........••......................•••• 5 Liquefaction ....•....••................•.•..•.•••. 6 Other Hazards •......•.•..............•••••.••.••.. 6

CONCLUSIONS •••••••••••••••••••••••••••••••••••••••••• 7 RECOMMENDA1'IONS •••••••••••.•••••••••••••••••••••••••• 8 LIMITATIONS AND UNIFORMITY OF CONDITIONS •••••.••••••• 9 REFERENCES •••••••••.•••..•••••••••••••••••••••••••••• 11 APPENDIX

Vicinity & Regional Fault Map - Plate I Site Plan & Geologic Map - Plate II Site Plan and Buildable Arca - Plate III Logs of Exploration Trenches - Plate IV

BUENA ENGINEERS, INC.

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GEOLOGY REPORT

TAX PARCEL 3052-30-18

35813 38th STREET EAST

LOS ANGEI,ES COUNTY, CAI,IFORNIA

INTRODUCTION

This report presents a surrunary of our geology services for the subject parcel located near Palmdale, Los Angeles County, Cali­fornia. The report was prepared in accordance with authorization by Mr. Karl Brown on April 6, 1984. The purpose of our services was to review the site geologic con<'litions and provide comments and recommendations r,elat.ive Lo the proposed site development and observed geologic hazards.

Tax Parcel 3052-30-18 is an existing lot planned for one single family residence. Minimal site grading is anticipated with planned sewage disposal by on-site septic tank and leachfield.

The site geologic conditions were evaluated in the field and through selected technical publications. Conclusions regarding the site are based on the data collected and form the basis for the recommendations presented.

SITE DESCRIPTION

The+ 1.7 acre lot is located along the cast side of 38th Street East approximately 700 feet south of Avenue T-8, Palmdale, Los Angeles County, California. The lot is described as a portion of the SWl/4, NWl/4, SWl/4, Section 8, 'l'SN, RllW, SBBM. Access to the site is via 38th Street East which is a poorly graded dirt road ...

Topographically, the site consists of gently rolling hills along the west side and relatively flat alluviated area along the east.

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On-site slopes are relatively gentle with the building site being flat and level. Drainage is by sheet flow to moderately defined drainage courses which direct runoff to the east and northeast.

Vegetation consists of typical desert plants including junipers, joshua trees, shrubs and grasses. There are several domestic trees planted on and near the site.

Existing improvements include fence posts around the entire site, and the California Aqueduct along the south boundary. It was a.pparent that a portion of the aqueduct embankment near the southwest property corner was severely eroded and appeared unstable.

FIELD EXPLORATION

The field work for this project was conducted on April 9, 1984, and consisted of a site reconnaissance and excavation of one exploration trench. The trench was approximately 240 feet in length and extended approximately five to six feet below the existing ground surface. The approximate location of the trench is shown on the Site Plan, Plate II.

The trench was excavated with a tractor mounted backhoe and was oriented approximately perpendicular to the general trend of faulting in the area. Portions of the walls and bottom of the trench were cleaned of loose or smeared soil and a graphic log compiled illustrating the approximate locations and orientations of pertinent features observed. The log is included on Plate IV of this report. Previous geologic mapping prepared by Barrows, et al (1976) was also utilized to aid in interpretation of the site geology. In addition, trench data from an adjacent project (B-1967-LOl) was also used.

GEOLOGIC SETTING

'l'he project site is located at the base of the San Gabriel Moun­tains in Southern California. The San Gabriels are a part of the Transverse Ranges which extend in a southeast-northwest directjon across Southern California. Rocks con~osing the Transverse Ranges consist of an extremely complex group of folded and faulted rocks varying from Pre-Cambrian gneisses to modern alluvial deposits. North of the San Gabriel Mountains in a vast area of desert basins and mountain ranges comprising the Mojave Desert where Pre-Cam­brian, Paleozoic, and Mesozoic rocks are encountered along with

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Cenozoic lake and fluvial deposits. Dividing the Transverse Ranges f:rom the Mojave Desert is the San Andreas i:-ift zone.

The San Andreas rift zone, which is up to several miles wide, dominates the landscape in the Palmdale area with classic fault features and geologic structure. The rift zone is an extensive zone of active and potentially active faults that extend from the Gulf of California to Cape Mendocino in Northern California. Right lateral offset of many streams and gullies averaging 10 to 13 feet apparently records the most recent fault movement along this portion of the main trace of the San Andreas fault. Abundant smaller active and potentjally active faults within the San Andreas rift Hone lie north and south of the main trace of the San Andreas fault. These include the Little Rock fault, Cemetery fault, Nadeau fault, and abundant subsidiary faults. Quaternary movement is locally evident along these faults.

SITE GEOLOGY

The subject parcels are located within the San Andreas rift zone and more specifically within the Little Rock fault zone. Differ­ential movement within tl1e zone has resulted In the irregular top­ography and the deformation and faulting of lithologic units with­in the fault zone. Regional lithologic units consist of Cenozoic sediments and sedimentary rocks overlying pi:-e-Tertiary granitic rocks.

Descriptive Geology

On-site lithologlc units encountered on the subject parcels consisted of Holocene alluvial deposits (Qal) and residual soil (Qrs) overlying Quaternary older alluvium (Qoa) and Pliocene Anaverde red arkose (Tar). Descriptions of the units encountei:-ed are as follows:

Pliocene Anaverde Formation, Red Arkose {Tar): The Anaverde Formation consists of continental sediments derived from source areas located to the north. Due to movements within the San Andreas fault zone, members of the Anaverde Formation are typically folded and faulted and contain abundant internal shears. Only the red ai:-kose member (Tar) is exposed in this pai:-cel. This member consists of tan to reddish tan, fine to medium grained arkose which is well bedded, and severely weathered.

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Quaternary Older_!:.J:_l_uvium (Q~~)__:_ The older alluvium consists of reddish tan to brown, fine to coarse sands and sandy gravels. The deposits are variably cemented and range from loose to very dense. The older alluvium is differentiated from younger alluvial de­posits in that the older alluvium is generally dissected and lies topographically above existing drainage courses and areas of active deposition.

Holocene Alluvium (Qal): Holocene alluvial deposits consist of l'nterbedded layers of fluvial sand, silt, and some gravel. The deposits are moderately to poorly bedded and typically loose to medium dense. They are the result of depositi.on of sediments by relatively recent fluvial processes.

Residual Soil (Qrs): Holocene residual soil consists of clayey and silty sand generally derived from the underlying lithologic units. The soil was up to three feet thick where observed in the exploration trenches.

Faults

The project is located within the San Andreas rift zone which in­cludes the San Andreas, Little Rock, Nadeau, and Cemetery fault zones. The subject parcel is within the Little Rock fault zone, which in this area is up to approximately 1,000 feet wide. Addi­tional faults within the general vicinity of the site include, the San Andreas fault 750 feet southwest of the site, the Nadeau fault, 3200 feet south of the site, and the Cemetery fault 4,000 feet north of the site. All referenced distances are approximate.

The active main trace of the San Andreas fault is readily apparent by abundant fault features such as aligned ridges and valleys, sag ponds, and offset drainages. The fault is characterized as a near vertical strike-slip fault with right lateral movement.

Individual faults within the Little Rock fault zone are generally subparallel to the San Andreas fault and vary from steeply dipping strike-slip faults to shallow thrust and normal faults. Ample evidence of fault activity was observed in the exploration trenches excavated on this and adjacent properties, The faults were typically characterized by offset bedding, root lines, shears, and soil infillings. Due to the proximity of the observed faults to the active San Andreas fault, these faults should be considered at least potentially active.

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The Little Rock fault zone is considered subsidiary to the San Andreas fault and movement within the Little Rock fault zone will most lik.ely occur sympathetic to movement along the San Andreas fault. The Nadeau fault located south of the project and the Cemetery fault located north of the subject property are also considered subsidiary faults to the San Andreas, These faults are classified by the State as potentially active with some segments showing evidence of Holocene displacement, possible associated with movement along the San Andreas fault in 1857.

GEOJ,QGIC HAZARDS

Geologic hazards which may affect the proposed land development include potential fault rupture, other earthquake related hazards, and minor flooding and erosion. Due to the relatively moderate topography, lack of steep slopes, and relatively shallow bedrock, hazards due to landslides, seismic settlement, or slippage are considered negligible.

Faulting

Several significant 1ones of faulting were observed to trend across the property. Fault rupture and ground lurching will most likely occur along these previously established faults or fault zones. Construction of· structures over or immediately adjacent to the observed faults, may be subject to potential differential movement <luring a major earthquake occurring along this portion of the San Andreas or Little Rock fault zones. Ground lurching, defined as ground cracking with permanent soil deformation will most likely occur immediately adjacent to active faults.

Ground Shaking

A primary geologic hazard relative to site development is con­sidered to be ground shaking resulting from a major earthquake originating on the San Andreas fault, The last major seismic event felt in the Palmdale area occurred in 1857 during the Fort Tejon Earthquake. The event was estimated to have a Richter Magnitude of 8.25 and was felt throughout much of Central and Southern California. Fault rupture along the San Andreas fault zone occurred near Parkfield, California to Cajon Pass with relative offset across the fault of 10 to 30 feet. Modified Mcrcalli intensities felt during the earthquake in the Palmdale area are estimated to have ranged from approximately VII to VIII.

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Significant earthqua~es have occurred on other faults in Southern California which have been felt in Palmdale. These include the 1872 Owens Valley earthquake (Modified Mercalli intensity at Palmdale of VI), 1952 Arvin-Tehachapi earthquake (VII), and 1971 San Fernando earthquake (VI).

Based on the hypothetical great earthquake similar to the 1857 event (Davis 1982), the Palmdale area could experience Modified Mercal.li Intensities as great as IX., Significant earthquakes originating on faults in Southern or Central Californla other than the San Andreas are expected to have intensities at Palmdale of less that IX.

It should be noted that the level of damage predicted by the Modified Mercalli Scale is based on past experience of a given earthquake on buildings not designed to present building stan­dards. Damage to structures designed to current standards is expected to be less. However, possible structural damage should be anticipated to buildings within this area due to potential severe ground shaking. A description of the damage which is presented on Table I 6f this report.

Using data from Sieh (1978) relating to the recurrence intervals of major seismic events of the San Andreas fault, it is estimated that a major earthquake has occurred along this segment of the San Andreas fault every 100 to 200 years. The average recurrence interval is estimated to be 140 years. As the last major earth­quake on the San Andreas fault in this area occurred in 1857, the occurrence of an earthquake in this area within the estimated lifetime of any new construction in considered likely.

Liquefaction

Liquefaction is the loss of strength of saturated cohesionless soils generally due to seismic shaking. As the material underlying the site consists of medium dense silty and gravelly soils overlying relatively shallow bedrock, the potential for liquefaction is considered negligible.

Other Hazards

Other hazards may include erosion and flooding. from the eroded aqueduct bank near the southwest that further degradation of the embankment could flooding of the site. In addition sheetflooding

BUENA ENGINEERS, INC.

It was apparent property corner, result in serious during intense

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May 3, 1984 Table I B-2119-LOl

Modlfh>d Mercolll lnten•ity Scale of 1931', (1956 version)>

Masonry A, B, C, D. To avoid ambiguity of language, the qualily of masonry, hrir:k or othc.-wisc. is spCcificd by the following leltering.

Mnsonry A. Good workrnanship, mortar, and design: reinfon::cd, cspec..;ially laterally, and bound logelher by usiug steel, t;ur1crete 1 etc.; designed to resist lateral forces.

Masonry B_ Good workmanship and morlar; reinforced, but nol dr.signcd in d~tc.il to resist Jcitci·•:il forces_

Masonry r._ Ordinary workmanship and mortar; nu extreme WP.aknes.scs like failing tu tie in al ·corners. Lul rit:Hhi::r relnfort;t:d nor dcsignt~d against horizontal for­ces.

Mosunry D. Weak materiLlls, such n1cinship; weak huti:r.or~ta11y.

as adobe; i-iuur H1ur!i:lr; low standards of work-

[_ Not fett. Marginal and long-perio.j eff~r;ts of lf.lr~e aertt1quakas, ~-·----~~~~~~~~~

IL l='elt by perwn!lo al rasl. on uppHf noors, or favorably placed_

III. Felt il'ldoors._ Hanging objects swin~. Vibrf.llion like p?..ssing of li!ijht vucks. Ouralion estirrraled. May not be recognii:ed as an ef,lrttiqueke_

IV. Hangtn~ objects. swing. Vibr(!tian like pas~ing of heP..vy truck!i; or sensalion of a jolt Hko e ha:=tvy b,f.111 s.1riki11g n1a w2lls_ Standing motor cars rock_ Windows, di:sh~s, doors rattlfl, Gh'IS-~S clink. Crockary c!P..shes_ In lho uppor (3nge of IV wooden walls and frame creak_

V. !="ell outdoors; direc!ion estimated, Sleepers wakern:id. Liquids disturbed, some spilled. Small un­M11blu Objflcls displaced or upsat 000($ swi(1g, clos.o, open. Stiul!crs, pic!1,ires move. Pendulum clocks $!up, start. c~1a11go rate.

~~~~~~-~~~~~-

VI. Fell by ell. M.fl.ny friQhtened and run uuldoors. i='ers.ori::> W3lk uns:eadily_ Winduws, dishE':!~. gl~sswi."lre b(ok.erL Knickknacks, books, etc .. ott s!ielves. Pictures. off walls. Furniluro n10 ... ed or overl\Hned. Wt=!ftli; p1.£i$ler and ma"t":-onry D cracli;ed. Small bells. ring {church. !;1-Chool)_ T1ees, bushes shaken 'o'isibly, or he::i.rd lo rustle.

_, __ ..,____ ·-····- ·-·-- ··-- --------j VII. D1fficutl to s,IF.ind, Noticed by drivers of motor cars. Hanging objgcls quiver. Furniture broken.

--

Du1naQO to masonry D, iricludirig crilcli:s. Wei:ik chirnnttys. bcok€:1n at (OOf lini:!-_ Fall or plaster. loof.e brick.s. Monos, tiles. co(riices al.so unbr.l'lcerl p::i.rapets and archi!P.ctur~I O(f"ltirnent~. Some cracks in rn<'lsonry C. Waves on pond.s;; W(l.ler turbid with mud, Small slides and caving in akJng sand Of grav(]I banKs, lf'lrge bells ring. Concrete irriga.tiO!'I ditches darn.aged_

Vlll. Steering of motor cars affected. DamR!JB to mAs.onry C; partial c;ollaps.e. Some damage to masonry B; none to masonry A. Fall or stucco end !!Oma m1;:1sonry wells. iwis!ing, f;r.ill of chimneys, factory sleeks, monuments, towers, elt.ivatad tanks.. fr'1rne ~1ou~s t1)0Yed on founde.tions i1 not bolled down; loos-a panel walls: thro11tn out. Decayed piling broken off. Branche!lo bro'ii;en from trees. Changes Jn fl.ow or temperature of spring~ and wells. Crack~ in wet ground end on sle"'p slopes_

IX. General panic_ Masonry 0 deslroyed: rna!'"-Onry C heavily da.mfl~ed. ~metimes with cornplele collapse; ma~nry B seriously damaged. c:'.3enerel damage to foundations. Frame struc;tures, if not bollttd, ~ift~d off foundation:!i. Ftame~ racked. Serious. damage lo reservoir:$. Undorground pipe:s broken. Consplcuous crac~s in ground. In alluviated areas sand and rnud ejecied. earthquake foun­leins, sand crelers.

X. Most mssonry ancf frame -structures destroyed with their foundation~. Some well--built woad~n sfruc~ tures and bridge!3 daslroyed. Sariou!j.. damage to darns. dikes, embank.mont-s. Large landslides, Waler lhrown on benk!i of c;enels, rivers, lakes, ale. Sand and mud shifted horil.onla.lly on be:eL--l'1e:s and flat lend. Ra.113 bent slightly. -·- ------------ ·--------··

XI. Rails bent greatly. Underground pip-0llnes co1npkHoly out of :!lervice. -------------·---·-·- ... -····--·

XII_ Damage nearly total. l erge rock me~.as ells.pl seed. llnu:!li of sight end l1;1vel distorted, Objects thrown lnlo the alt. •

10rigln&I 1931 -wef:!lli'.>ri in Wood, t-1:. 0 .• and Neumaf\n, F., 1931, Modili~d Ml;l'ri;:<'lli in18nsily 9cale of 1931: Seismologic.al SociB-ly or Amlitrir.i/I B~tfftti'I, v. ~.no. 5, fl. 9'19-~a7.

:1195-6 ..-errgion pr~.:ir&d by Chtuli::is F. Rn::hl!!lr, in Elemerllsry Sei.smology, 195S, i;i. 1:37-13.8, W. H. Freeman & Co.

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May 3, 1984 Pilge 7 B-2179-LOl

periods of rilinfall could also result in minor on-site flooding and erosion.

CONCJ.USIONS

Based on the field reconnaissance, 1:renching, and literature re­view, it is our professional opinion that the primary geologic hilzards relative to site development for residential purposes are fault rupture, ground shaking, flooding, a11d erosion. No obvious ground rupture or other evidence of recent ground movement was observed across the delineated "Building Areas". Traces of the Little Rock fault project through the property approximately as shown on the Site Plan. If construction for human habitation is intended outside the areas designated, additional exploration should be required to verify the absence of faulting at the additional building locations.

The site is located within the San Andreas rift zone. Therefore, there is a potential for structural damage to any building in this area due to severe ground shaking. It is our opinion that a sig­nificant seismic event resulting from movement within the San Andl'.eas rift zone may occur in this area in the lifetin1e of any new construction. Ground rupture would most likely occur along previously established zones of weakness; however, there is no guarantee that ground rupture will not occur at other locations. Earthquilke intensities as great as IX bilsed on the Modified Mercalli Intensity Scale should be anticipated during severe seismic activity.

Possible flooding and erosion could occur in the vicinity of the site due to sheet flooding and aqueduct embankment failure. Proper site milnagement and site grading can mitigate the sheet flooding hazard. Appropriate state ilgencies should repair the aqueduct embankment. As the delineated "Buildable Areas" are relatively flat, sewage disposal by leachfield should not ad­versely impilct the slope stability of the property.

Based on the findings summarized in this report, it is our pro­fessional opinion that construction within the "Buildable Area" would not be subject to a geologic hazard from seismic settle­ment, slippage, or landslides.

It is also our opinion that the proposed improvements and antici­pated site grading will not adversely affect the geologic sta­bility of the site or adjacent properties provided the recommenda­tions contained within this report are incorporated into site

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grading. Test findings and statements of professional opinion do not constitute a guarantee or warranty, expressed or implied.

RECOMMENDATIONS

Based on the field reconnaissance, exploration trenches, and other data collected, the followi.ng recommendations are provided.

1. It is recommended that "Restricted Use" areas be delineated and defined as a twenty-five foot offset from the projec­tions of the identified faults. Construction of habitable structures within the "Restricted Use" areas is not recom­mended.

2. Any on-site construction for human occupancy should be con­fined to the designated "Buildable Area" (See Plate III). Additional trenching may be required for construction out­side this area.

3. Construction should allow for all plumbing and utility ser­vices to be connected with flexible connections and/or pro­vided with convenient shutoffs.

4. Diversion and reduction of concentrated runoff should be pro­vided to minimize erosion of on-site slopes and improvements.

S. The aqueduct embankment should be repaired and maintained in order to reduce the potential flood hazard. Appropriate state agencies should be contacted so that repair is done prior to the next rainy season.

6. Grading Plans, if required, should be in accordance with existing building codes. It is recommended that the project engineering geologist or his representative review the grading plans prior to construction and site development during the site grading phase only if a grading permit is issued.

7. The proposed residence location should be checked in the field prior to construction by the consulting geologist so as to verify location within the "Buildable Area". Field review of building locations and site grading, if required, will be at an additional expense and will be billed at current fee sched­uled rates.

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LIMITATIONS AND UNIFORMITY OF CONDITIONS

The conclusions and recommendations submitted in this report are based in part upon the data obtained from two (2) exploration trenches, site reconnaissance, and stereo aerial photo review. The nature and extent of variations from observed conditions may not become evident until construction. If variations then appear evident, it wjll be necessary to reevaluate the recommendations of this report.

A field log of the exploration trenches were prepared by our geologist. The logs contain information concerning the interpre­tation by the geologist related to lithologic description, strati­graphy, and structure. Therefore, the logs contain both factual and interpretive information. It must be emphasized that our conclusions and recommendations are based on the final logs which represent our interpretive information. It must be emphasized that our conclusions and recommendations are based on the f i.nal logs which represent our interpretation of the features observed.

In the event that any changes in the nature or location of the proposed development arc planned, the conclusions and recommen­dations contained in the report shall not be considered valid unless the changes are reviewed and conclusions of this report modified or verified in writing.

This report is issued with the understanding that it is the responsibility of the owner, or of his representative to insure that the information and recommendatjons contained herein are called to the attention of the architect and engineers for the project and incorporated into the plan and that the necessary steps are taken to see that the contractors and subcontractors carry out such recommendations in the field.

It is recommended that the consultant be provided the opportunity for a general review of final design, grading plans (if required) and site grading in order that the earthwork and structural rec­ommendations may be properly interpreted and implemented in the grading and construction phase of the project. (If the consultant is not accorded the priviledge of making this recommended review, ho can assume no responsibility for misinterpretation of his recommendations).

BUENA ENGINEERS, INC.

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May 3, 1984 Pctge 10 B-2179-LOl

The Engineering Geologist has prepared this report for the exclusive use of the Client and authorized agents. This report has been prepared in accordance with generally accepted engi­neering geology practices. No other warranties either expressed or implied are made as to the professional advice provided under the terms of this agreement, and included in the report.

It should be recognized that this report does not guarantee issuance of grading or building permits. Any additional work which may be required after submittal of this report such as footing excavation and rough grading reviews is not included as part of our initial agreement and will be billed at fee schedule rates applicable at the time of the additional work.

We trust this report is sufficient at this time. If you have any questions regarding this information or require additi.onal stud­ies, please contact us.

Respectfully submitted,

BUENA ENGINEERS, INC.

IJJk4 J. J;;~---Mark S, Spykerman R.G. #3800 E.G. #1174

MSS/MVS/REB/sam

Appendix

Michael V. Smith R.G. #3273 E.G. #956

BUENA ENGINEERS, INC.

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May 3, 1984 Page 11 13-2179-r.Ol

REFERENCES

1. Barrows, A.G., Kahle, J.E., and Beeby, D.J., 1976, Geology and Fault Activity of the Palmdale Segment of the San Andreas Fault Zone, Los Angeles County, California, CDMG Open File Report 76-6 LA.

2. Buena Engineers, Inc., 1982, Geology Report, Tentative Tract No. 13435 and Tax Parcel 3052-30-1, File No. B-1967-J.Ol, April 2, 1982.

3. California Division of Mines and Geology, 1969, Geologic Map of California, Los Angeles Sheet.

4. , 1975, California Geologic Data Map Series, Map No. 1, Faults, Volcanoes, Thermal Springs and Wells.

5. , 1977; Fault Hazard Zones in California, S.P. 42, Revised January 1977.

6. , 1977, Active Fault Mapping and Evaluation Program, S.P. 47.

7. , 1979, State of California Special Studies Zone, Palmdale Quadrangle.

8. Davis, James F. et al, 1982, Earthquake Planning Scenario for a Magnitude 8.3 Earthquake on the San Andreas fault in South­ern California, C.D.M.G. Special Publication 40.

9. Dibblee, Thomas W. Jr., 1967 Areal Geology of the Western Mojave Desert, California, U.S. Geological Survey Professional Paper 522.

10. Gates, G.E., 1972, The San Fernando Earthquake of February 9, 1971 and Public Policy, Special Subcommittee of the Joint Committee on Seismic Safety, California Legislature, July 1972,

BUENA ENGINEERS, INC.

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May 3, 1984 Page 12 B-2179-LOl

11. Kahle, J.E., Smith D.P., and Beeby D.J., 1975, Geology of the Leona Valley Segment of the San Andreas fault zone, Los Angeles County, California, C.D.M.G. Open File Report 77-1 LA.

12. Noble, Levi F., 1953, Geology of the Pearland Quadrangle, California, U.S. Geological Survey, Geologic Quadrangle Map of the United States.

13. Sieh, Kerry E., 1978, Earthquake Intervals, San Andreas Fault, Palmdale, California, California Geology, June 1978.

Aerial Photographs:

From: Scale: Date Flown: Frame #' s:.

I.K. Curtis 1:12,000 June, 1971 8171, 8172, 8173

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I May 3, 1984 Page 13 13-2179~L01

I I I I I I

APPENDIX A

I Vicinity & Regional Fault Map - Plate I

I Site Plan & Geologic Map - Plate II

I Site Plan and Buildable Area - Plate III

I Logs of Exploration Trenches - Plate IV

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