county of los angeles .. ap -...

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.. ' COUNTY OF LOS ANGELES DEPARTMENT OF PUBLIC WORKS 660 9. AVENUE LOS ANGELES, CALIFORNIA 90020 TeJ,ptii;in.-; (21!1) 7SB-20ll AP I 841 THOMAS A. TIDEMANSON, Director HIAM BAR MACK, JAMES L. EASTON, Dlrtttor WYNN L SMITH. Orptil)' Dlrrctor ADDRESS ALL CORRESPONDENCE TO: 550 $. Vi!:RMONT AVENUE l..OS ANGf,:LES, (::A.Llt"ORN'IA 90010 P. Mr.Earl Hart California Division Of Mines & Geology Bay Area Regional Office 380 Civic Drive, Suite 100 Pleasant Hill, Calif. 94523-1997 Dear Mr. Hart, IN Rl;Pl,.V PLE:.6.SE AEfER TO Fll.e: 1-8-86 Per your letter,datcd 1-3-86,we are submitting the following review sheets for your use,and to be placed with the reports which you listed. The reports and sub- sequent review sl1eets are intended for open filing under the Alquist-Priolo Special Studies Zone Act. Please accept my apology for the delay in submitting complete materials to you. Clerical personnel changes arot1nd that time was the reason. Thankyou, . z,J /;;-0 ,/ /d&':--- .,/ .. , / Jeffrey A. Weldon Regional Geologist North County Dist.#8.0 Los Angeles County

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Page 1: COUNTY OF LOS ANGELES .. AP - gmw.consrv.ca.govgmw.consrv.ca.gov/SHP/APSI_SiteInvestigationReports_OCR/APSI_001818/... · 06/11/1985  · --o F X NF __ _ ---SHEET 1 OF 1 a/PM '" Tr

.. '

COUNTY OF LOS ANGELES DEPARTMENT OF PUBLIC WORKS

660 9. Vl-~KMONT AVENUE LOS ANGELES, CALIFORNIA 90020

TeJ,ptii;in.-; (21!1) 7SB-20ll

AP I 841

THOMAS A. TIDEMANSON, Director

HIAM BAR MACK, Chl~f ~put}' Dlre~tor

JAMES L. EASTON, Chl~f D~puty Dlrtttor

WYNN L SMITH. Chl~f Orptil)' Dlrrctor

ADDRESS ALL CORRESPONDENCE TO: 550 $. Vi!:RMONT AVENUE

l..OS ANGf,:LES, (::A.Llt"ORN'IA 90010

P.

Mr.Earl Hart California Division Of Mines & Geology Bay Area Regional Office 380 Civic Drive, Suite 100 Pleasant Hill, Calif. 94523-1997

Dear Mr. Hart,

IN Rl;Pl,.V PLE:.6.SE AEfER TO Fll.e:

1-8-86

Per your letter,datcd 1-3-86,we are submitting the following review sheets for your use,and to be placed with the reports which you listed. The reports and sub­sequent review sl1eets are intended for open filing under the Alquist-Priolo Special Studies Zone Act.

Please accept my apology for the delay in submitting complete materials to you. Clerical personnel changes arot1nd that time was the reason.

Thankyou,

Si~~.erly, . z,J /;;-0 ,/ /d&':---

.,/ .. , /

Jeffrey A. Weldon Regional Geologist North County Dist.#8.0 Los Angeles County

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.... ENGINE~FU"-'G GE::OLOGY SECTION Dist. Office • g 0

(~13) 738-2161

Q: --- -F~ ~ '"' ~~ GEOLOGIC REVIEW SHEET

--o F X NF __ _

---SHEET 1 OF 1

'"

a/PM Tr. 14631 Lot 51 Site Address 14348 Aldirwood

COUNTY OF LOS ANGELES OEPARTMENT OF ENGINEER-FACILITIES

ti60 SO. VERMONT AVE., LOS ANGELES, CA 90020 DISTRIBUTION: 2._ Dist. Engineer l. Geologist

Location Lake Eli zab• th _ Soils Engineer / l_ Geol. Sect. File Geologist Geo Plan Ino. Developer/owner Ridgetop Ranch Prop.

Soils Engineer------------- Engineer T. Pendle bury _ Grading Section

Review of:

Action:

PLAN CHECK NO. OR OATE OF REPORT(Sl

0Grading P.C. No.---=-="'=-.-=--...---------------------------~uilding P.c. No. 1024 (Rea.) DGeologic Site Inspection Only P,,_c. No. --oc---=-----=c------..=---=~=~-----------c:JGeologic Report Dated __,,l.,.l"'-"'~'-""'"'g'-5,.,.,_,,G"'e=-o"-'Ji'._l=a,,,n__,,I=n'-=c'-''----'(-=P-=r'-"o'-'.l,_,,.._5,_,o,,_7"''""7...._) __________ _ DSoils Report Dated ---------------------------------0Geology & Soils Report Dated _____________________________ _

DPlan isgeologically approved

::tJ Plan approved geologically subject to conditions below

DSec. 309 Code requirements met (not mot)

DSec. 30B(b) 3c & e code requirements met (not met)

0 Plan is not approved for reason! below

DSubmit plans for recheck

Plan approved provided the consultants recollllllendations are followed. Aleo it ehould be noted that backfilled trench excavation utilized in this investigation an•tfDw llll'.y be subject to Settleme!'lt unleee backfill materials were reoompaoted. Consultant to inspect and approve tooting excavations prior to place­ment or steel and/or concrete.

16GJOA - PS 9·84

.... :;,

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0 • • ..

O". • _ENGINEERING Gl::OL.OGV GROUP GEOLOGIC REVIEW SHEET

.. , '

. '7'. CJ Dist, Office--~---

COUNTY OF LOS ANtlE.LES DEPA~TME:NT OF PUBLIC WO R:KS

F X NF ____ _

OF I / (213) 738·2828

.!li!iO 50. VER:MONi AVC.., LOS ,ANQEL.ES, CA 90020 SHEET

DISTRIBUTION:

LOT(SI -"""'-'/'------'-------~

PLAN Cl-IECI< NO. OR OATE OF FtEPORT(S)

2- Dist. Engineer

Geologist Soils Engineer Geol. Group Fi1......--·· Grading Section

Review of: D Grading P.C. No. .;,..-

.)S"Building P.C. No. /O~i/ (lfk)J D Geologic Site Inspection Only P.C. No. D Geologic Report Dated

\ .

0 Soils Report Dated-----------------------------------'---~ D Geology & Soils Report Dated

Action: O Plan is geologically approved 0 Plan approved geologically subject to conditions below D Sec. 309 Code requirements met

Remarks:

~Plan is not approved for reasons below -""!.Submit plans for recheck

1. W'" A con•ulting .AJ: engineering geology 1 D soils engineering, ..5-report(s) is required

2. )i1 All recommendations of the consulting .M'Qeologist, 0 soils engineer ~must be incorporated in the design or shown as notes on the plans.

3. J<:!. The plan must be specifically approved by the ~consultant geologist, 0 congultant soils engineer by ~etter-report and/or Jlitmanual. original signature(sl with date(s) prior to approval by the Geology Group.

4. D ln..grading inspections must be made by the consulting Ogeologist, Osoils engineer. O Inspection reports must be submitted to the Geology Group for review monthly. Notify Geol0gy Group upon start of grading.

5. O Rough grading must be approved by a O final geology report, D final soils engineering report Prior to approval by th.• Geology Group. D An As·Built Geologic Map must be included in the final geology report.

6, Ji/. Foundation and/or wall excavations must be inspected and approved by the consulting ..(l:;L geologist, 0 soils )~.;.:· 'engineer, prior to the· placing of steel or concrete.

7. ' D The County Enginear'Soils Engineering Section's. D approval is required D requirements attached D conditions of approval are attached D approval ls required (dated )

8. D Show all proposed tentative corrective devices (e.g. buttress, stability fills, subdrains, etc) on the plan. 9. D Add items and , above, as notes to the plan.

1 O. .Ia:'.The geologist tJ (and) the soils engineer .8-must make a finding in accordance with Section 309, L.A. County Building Code.

Prepared by -----,r§~,,·~·~~M~-~&~.,n-"'------76G30 - PS 7·85

Reviewed bv,.,,P"'-"-' ...... r:.'-'-----""Az:~f.L.i!L'·~""-+--- Date

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-STA.TE OF CALIFORNIA-THE RESOUR~ES AGl;NCY

Df;PA!l!TMENT OF CONSERVATIOl'lil

DIVISION OF MINES AND GEOLOGY BAY AREA REGIONAL OFFICE 380 CIVIC OR1Ve, SUllE: l 00 PLEASANT Hill, CA 94.513-1997

PHONf; (<4l.5) 671-.. 920

Art Keene, Room 408

Pn . ,' t.· i!l - \ #'

L.A. county Department of Public Works Engineering Geology and Soils Group 550 South Vermont Avenue Los Angeles, CA 90020

Dear Art:

GEORGE OEUKMEJlAN, G9vcrmor

January 3, 1986

The following reports were received by this office without cover letter or attached review sheets:

Engineering geologic and seismic report, Lot 44, Tract 14631, Alderwood and Dogwood Roads, Lake Eli2abeth District, L.A. county, CA; by Geoplan, Inc.; Nov. 5, 1985.

Engineering geologic report, Lot 51, Tract 14631, Alderwood and cutwood Roads, Lake Elizabeth District, L.A. County, by Geoplan, Inc,; Nov. 6, 1985.

Geotechnical engineering report, Lot 244, Tract 24829, (42640 Montello Dr,), Lake Elizabeth, CA; by Buena Engineers; Oct, 18, 1985.

These reports presumably were submitted to us under the Alquist-Priolo Act, and will be placed on open file. In order to complete our files, please submit the signed review sheets to these reports.

Best wishes for the Holidays,

cc: A-P file (3) v'

sincerely,

Earl w. Hart senior Geologist

and Program Manager

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(

c

..

·.

·' ,•'

SOILS REPORT/GEOLOGY REPORT/DRAINAGE PLAN TRANSMITTAL

-~ - ''

submitted By: .. · I 'HO M"A!:-;,· L \?YXl'Dt .,_.r;'·1 •

CHECK APPROPRIA~E BOX;

Soils Report Review For:

[ ] Tentalive Hap - TR/PH' ~ [ ] [ )

. '

.Revised Hap~ TR/PM iJ ~ ... - '

Final Map - TR/PM 0

[ ] Grading Plan Check -

ci--Ylluilding Plan Check - BPC jJ I 0 -:;;. 'f [ ] Retaining Wall (to be submitted to Building & Safety)

[ ] . Soil Compaction - Rough Grading (to be submitted to "Building & .

[ ]

[ )

[ ]

[ ]

Safety District Offtce)

Site Inspection

Compaction R~ports For Sewer PC (to be submitted to Construction

Division) - --------Compaction Reports For

struction Division) -

Storm Drain PD (to be submitted to Con-·

--------0th er -----------

Geology Report Review For:

[ ) Tentative Hap -'TR/PM jJ

[ ] Revised Map - TR/PM u ( ] final Map - TR/PM 0 [ ] Grading Plan Check - GPC 0 . ,,

[ ] Building Plan Check - BPC U ( ] Rough Grading -( ] Site Inspection ( ] Other

Drainaie Plans, Maps or Calculations For: [ ] Grading Plan Check - GPC c [ ] Building Pla·n ·check - BPC II [ ] Drainage Concept - Ttl/PM /)

[ ] Private Drain /)

( ] Other

.;

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Engineering Geologic Report Lot 51, Tract 14631 Alderwood Road @ cutwood Road Lake Elizabeth District Los Angeles County, California Project 56767 November 6, 1985

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• @~[ID[p~ffi~r ~[i[)®a

consulting engineering geologists 18432 OXNARD STREET TARlANA, CALIF. 91356

John D. Merrill, President

November 6, 1985

Engineering Geologic Report Lot 51, Tract 14631 Alderwood Road @ Cutwood Road Lake Elizabeth District Los Angeles County, California

Ridgetop Ranch Properties 14370 Lake Elizabeth Road P.O. Box 716 Leona Valley, California 93550

Attention: Jerry Horwedel

Gentlemen:

18181881->063

Project 56767

In accordance with your instructions an engineering geologic

• and seismic investiga_tion has been conducted on lot 51 to determine

if the lot is underlain by active faults or earth materials that

may render it unsuitable for future residential development to be

served by a private sewage disposal system, Exploration was con-

ducted utilizing a backhoe to excavate a continuous trench along

the west property line, as shown on Plate 1, a geoloqic sketch map

that utilizes a survey dated 22 Aug 85 by Lloyd Pond, Licensed

Surveyor 3199, Lancaster, California, supplemented by measurements

with tape, compass and hand level. Illustrated log of the trench

and the percolation test pits are appended (Plate 2). Field explo-

ration was supplemented by review of substantial geologic and

seismic data contained in our files, including published reports

and maps (Plates 3, 4, & 5), as well as private research reports .

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• GEOPLAN, Inc.

CONSULTING ENGINEERING G!:0(0GISTS

Project 56767 Page 2 November 5, 1985

Stereographic aerial photographs, dated 8/11/59, at a scale of

1 inch equals 1820± feet, were reviewed. A list of references is

appended.

This report embodies the principles of investigation, analysis

and reporting as customarily practiced in the profession of engi-

neering geology in southern California, with emphasis on the require-

ments of the County Building Ordinance, but with due regard for

Note 49, Guidelines for evaluating the hazard of surface fault

rupture, and Note 44, form and content of geologic and seismic

reports by California Division of Mines and Geology. It was

written to be understood by reasonably well educated persons, but

ti' to avoid misunderstanding of terms and usage the reader is directed

to the Glossary of Geology, 3rd Edition, 1974, and to Webster's New

International Dictionary, unabridged, 1964.

This report is intended to convey geologic data which may be

utilized in preparation of building or grading plans and which may

be submitted to the appropriate reviewing authority. Persons uti­

lizing these data are cautioned that geologic conditions are complex

and bedrock is concealed by surficial earth materials. Because

of these conditions it is possible that latent defects are concealed

and such concealed defects, if present, are beyond the scrutiny and

evaluation of the engineering geologist.

Location and Topogr~phic Expression:

Lot 51 fronts on the south side of Alderwood Road at its inter-

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• GEOPLAN. Inc.

CONSULTING FNGINl:l:RING GEOLOGISTS

Project 56767 Page 3 November 6, 1985

section with Cutwood Road in the southeasterly portion of the Lake

Elizabeth Ranch Club properties. The location of subject property

with respect to principal roads and topographic features is illus-

trated on the accompanying Site Plan (Plate 4). Subject property

is located within Special Studies zone 21467 (Plate 3) associated

with the San Andreas Fault, the principal and most active trace

of which is located about 160 feet south in ~he vicinity of Kiptree

Lane (Plate 4), The fault trace is clearly identifiable by a linear

feature that includes a furrow 6 to 10 .feet wide and about 3 feet

deep, and by a nearly vertical, south-facing scarp that truncates

low hills and ridges and offsets watercourses in a right lateral

tit sense. Moreover, the fault acts as a ground water barrier which

accounts for numerous springs and seeps and the characterizing

linear pattern of high water use vegetation (hydrophytes) that

include grasses, shrubs and trees known as phreatophytes. Although

ground water is at or slightly below the surface in parts of the

rift valley, especially near Kiptree Lane, it is more than 15 feet

beneath the surface at lot 51.

Lot 51 slopes southward almost imperceptibly, but about 50

feet beyond its south boundary the slope steepens abruptly on the

north flank of a low, rounded, west-trending ridge traversed by

Joshua Tree Drive (Plate 1) . South from Alderwood Road the slope

flattens on the floor of the San Andreas rift valley which supports

an ephemeral east-draining stream flowing about 200 gallons per

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GEOPLAN, Inc. CONSULTING ENGINEERING GEOLOGISTS

Project 56767 Page 4 November 6, 1985

minute. At some past time the stream was diverted from a course

through or very near lot 51 to its present location south from

Kiptree Drive through capture by a more actively eroding water-

course that had been accelerated by movement on the San Andreas

fault. Whereas the older watercourse was flat and probably sup-

ported a meandering stream, the present stream is straight and

has been deepened by accelerated erosion in the rea~h shortened by

capture.

Lot 51 is in a depression in which .development should be pro-

tected by raising the pad grade 3 to 4 feet.

Geologic Elements:

Subject property and its immediate environs are underlain by

surficial deposits known as slope wash or older alluvium (map

symbol Qoal) derived by erosion of nearby slopes. Alluvium con­

sists of crudely bedded, clayey to silty sands distinguished by

subtle color and textural differences and topped by a poorly deve-

loped dark brown sandy residual soil darkened by oxidized organic

detritus. Young alluvium representing 5 successive floods masks

the older alluvium throughout lot 51. As shown on the illustrated

log of the backhoe trench (Plate 2), residual soil ranges from 2.0

to 3.0 ft. thick with no significant variation in texture or

cohesion. The basal contact of residual soil and the underlying,

older alluvium is obscure but distinguishable by color difference.

The soil is judged to be sufficiently old to permit its use to

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• GEOPLAN. Inc.

CONSULTING ENGIN£ER1N(i Gi=OLOG.1S'tS

Project 56767 Page 5 November 6, 1985

distinguish fault activity; i.e., faults that do not disrupt the

soil profile are not active.

An· upper unit of older alluvium penetrated in the backhoe trench

consists of very dark brown, moderately cohesive, poorly sorted silty

to pebbly sand. Cohesion of the upper 3 to 5 feet is imparted by

secondary white calcareous cement, but at depth the cohesion is

imparted by stiff, dark brown clay. Despite younger age, the

flood plain deposits that make up the top 2 feet are very cohesive,

with numerous small root tubes in each.unit suggesting that they

respresent successively older, buried residual soil profiles.

Bedrock is concealed by surficial deposits on lot 51, but is

tit well exposed in the roadcuts flanking the cul de sac of Cutwood

Road, about 250 feet north from the property, and at Dogwood Road,

about 400 feet northwest. Rocks exposed in the cul de sac on

Cutwood Road are units of the siltstone member of the Anaverde

formation (map symbol Tas). These strata of upper Miocene to

Pliocene geologic age consist predominately of deeply weathered,

light gray, crudely bedded siltstone and reddish arkosic sandstone

and conglomerate with thin interbeds of dark greenish-gray to

black siltstone.

Rocks exposed in the cut at the north end of Dogwood Road

consist of deeply weathered, dark reddish-brown mottled granitic

rock, probably a hornblende granite. According to Beeby (1979),

this rock is part of a unit known as granite breccia (map symbol

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G~OPL.AN, Inc, CONSULTING ENG!NEEAING GEOLOGISTS

Project 56767 Page 6 November 6, 1985

grbx), a type of deep seated igneous rock that has been subjected

to severe tectonic deformation.

The relationship between granite breccia and the siltstone

member of the Anaverde formation at lot 51 is concealed, but it

is likely that bedrock supporting the lot is granite breccia.

About 50 feet south from lot 51 the slope steepens abruptly on

the north flank of a low, flat-topped ridge traversed by Joshua

Tree Drive. This ridge is comprised of brown to yellow-brown

bouldery older alluvium or older alluvial fan deposits correlative

with units south of the San Andreas fault and exposed along San

Francisquito Canyon Road .

Examination of the sidewalls of the exploratory trench revealed

no evidence of active faulting, or that the alluvial deposits have

been affected by seismically induced ground displacement.

Geoplanning Analysis:

Based on the engineering geologic investigation and analysis,

including subsurface exploration and review of records and stereo-

graphic aerial photographs, it is concluded that lot 51 may be

developed residentially, provided such development is effected

within the framework of applicable elements of the County Building

Ordinance and the recommendations of the project consultants. A

development implemented within this framework will not be affected

by landslide nor will it have any adverse effect on neighboring

property .

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• GEOPLAN. Inc.

CONSULTING ENGIN!:FR1N(j GFOLOGISTS

Project 56767 Page 7 November 6, 1985

Percolation tests conducted as part of this assignment reveal

that earth material exposed in the exploratory trench has only

fair permeability, necessitating a fairly long leach trench system.

Test results are appended.

1) It is recommended that compacted and certified fill be

placed on lot 51 to raise pad grade 2 feet.

2) Roof runoff should be directed away from the building.

3) Surface and subsurface investigation confirmed that subject

property is not underlain by an active fault. Conversely, subject

property is within the boundaries of the Special Studies Zone de-

fined by the San Andreas Fault. Despite the long period of seismic

~ quietude that has existed in the reach between Cajon Pass to the

east and Tejon Pass to the west, there is reasonable expectation

that a moderately severe seismic event may occur during the pro-

jected economic life of a dwelling to be constructed on lot 51. In

this regard, strong ground motion is likely to take place from an

event about 10 miles from the site and having a Richter magnitude

greater than 5, with anticipated maximum ground acceleration of

.35g (Plate 6), of which the horizontal component, estimated at

2/3 of the total would be about 0.2g.

4) Percolation test results are appended and these indicate

that the proposed two bedroom dwelling may be served by a leaching

trench 67 feet long. Efficiency of the system depends on main­

tenance of the septic tank which should be pumped out every 2 to 4

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GEOPLAN. lne. CONSULTING E!NGINE"EFUNG GEOLOGISTS

Project 56767 Page 8 November 6, 1985

years, or as necessary depending on use.

There is no evidence suggesting potential rise of ground water

to the extent that it could affect safe operation of the leaching

system during the projected economic life of the develop!'lent.

Thank you for this opportunity to be of service. Please call

if there are questions regarding

JDM:sh

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GEOPLAN, In< .. CONSULTING ENGl"-IEERINC; GEOLOGISTS

Project 56767 November 6, 1985

REFERENCES

1) Beeby, David J. (1979); Geologic Map of the Lake Hughes Segment,

San Andreas Fault Zone, Los Angeles County, California; California

Division of Mines and Geology, Open File Report 79-2 LA.

2) Kahle, James E. et al. ( 1975) ; Geology of the Leona Valley Seg:men': .

of the San Andreas Fault Zone, Los Angeles County, California;

CDMG, OFR 77-2 LA.

3) Ross, Donald C. (1969); Map Showing Recently Active Breaks

Along the San Andreas Fault Between Tejon Pass and Cajon Pass,

Southern California; U.S. Geological Survey, Misc. Geological

Investigations Map I-553.

4) Dibblee, Thomas W., Jr. (1961); Geologic Map of the Bouquet

Reservoir Quadrangle, Los Angeles County, California; USGS,

Mineral Investigations, Field Studies Map MF-79.

5) Stereographic .Aerial Photographs ($/11/59); AXJ-9W-59 and

AXJ-9W-60; l"=l82Q±•.

6) Special Studies Zone Map FM 21467; CDMG (1974).

7) Schnabel, P.B., & Seed, H.B. (1972); Acceleration in Rock for

Earthquakes in the Western United States; univ. of California,

Berkeley, Report No. 72-2 .

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GtoPLAN, Inc. CONSULTING ENGl,...IOERING GEOLOGISTS

Project'56767 November 6, 1985

REFERENCES

PRIVATE RESEARCH REPORTS

Geoplan, Inc. (16 Jan 84); Engineering Geologic Report, Lot 72,

Tract 14631, Northwest Corner Cutwood Road At Alderwood Road, Lake

Elizabeth District, Los Angeles County, California; Project 36131

------------- (25 Jun 84); Engineering Geologic Report, Lot 73,

Tract 14631, Alderwood Road @ Cutwood Road, Lake Elizabeth District,

Los Angeles County, California; Project 46309.

------------- (5 Nov 85); Engineering Geologic and Seismic Report,

Lot 44, Tract 14631, Alderwood Road @ Dogwood Road, Lake Elizabeth

District, Los Angeles County, California; Project 56843

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PEHCOLATlON TEST PATE

OWNER __ Ridgetoo Ranch Prooerties, Inc.

CONTRACTOR Ridget2_.P_ Ra.nch Properties, Inc.

DATE--'--------·-----·--··-·----·

TEST HOLE A

DEPTH _5 __ Time Inch from

Board

---~·--

' 5 :.4 0 0

5:42 1

___ 5: 4]_ 2

5:53 3

6 : 1 0 4

6:30 5 ,.~-· ..•.. - .... , ··--~······-- L...............~.~··~-~~·,·~~,·--

7 :00 6 - ··~-

Time lnterval 5th to 6th

30 niin. Inch

Comments _, ... "-~-

-

''

·-··-

·-----

TEST HOLE B

DEPTH _5_

Time

":"0

5: 5 i

5:56

6:02

6 : 1 8 -·-

6:32

6:59

Inch from Board

0

1

2

3

4

5

6 T1me Interval 5th to 6th Inch

Page 18: COUNTY OF LOS ANGELES .. AP - gmw.consrv.ca.govgmw.consrv.ca.gov/SHP/APSI_SiteInvestigationReports_OCR/APSI_001818/... · 06/11/1985  · --o F X NF __ _ ---SHEET 1 OF 1 a/PM '" Tr

GWPLAN, Inc. COt'.1$1,.Jl,ljNO ENGINEERING GEOLOGISTS

Project

LEACH TRENCH/FIELD PERCOLATION TEST RESULTS

Test pit locations per appended

. Pit II P- A Pit Ii P- B

Pit depth

Pit depth

I

5 5'

Ti!lle (T) for drop of 5th to 6th inch,3'('.'.) min.

Time (T) for drop of 5th to 6th inch2 7 min.

Coefficient from Ryon's formula= T +2~· 24 • Use slowest rate, from P"'.'A, T--3a ·

Septic tank size "750gal. = ( 3 bedroom dwelling).

Procedure: Ryon's formula (30+2~,,24 ) is multiplied by 1/2 volume of septic tank

to determine leach trench area.

Minimum leach trench area = 'iJ'-·24 x 7~0 • 4 G9 sq. ft. 2.'?

Minimum leach field area= 1.5 X trench area ( ) = sq. ft.

No/.e:-··8y oli1~rJt/ 3rl._frcJve!~--/n--leach -french, eaclrt11'ear -_ : ____ fOof w1/ / comp r-1 s e . 7 Sf·-!"' I., f /,ere !Ore _ .....

4~C1=07/;near /'/.. leach -lrench re7u1red1 +

ct rea For /~s/.ella-h;n D .f skncf6y srslem r / .f needed

Page 19: COUNTY OF LOS ANGELES .. AP - gmw.consrv.ca.govgmw.consrv.ca.gov/SHP/APSI_SiteInvestigationReports_OCR/APSI_001818/... · 06/11/1985  · --o F X NF __ _ ---SHEET 1 OF 1 a/PM '" Tr

NOT£.: ·

,. . ___ __. -

. I

JOSHUA TP.£.£ OR/Vt:. . . ' ·.

. . . ;-: .~:,

•, . ·' ' '.-·~ .. ' ; ' . ; ~-.. •, _.. .· ... ;. .....

. . ·r· .•'

-·. - .. ' '

' ' '

Page 20: COUNTY OF LOS ANGELES .. AP - gmw.consrv.ca.govgmw.consrv.ca.gov/SHP/APSI_SiteInvestigationReports_OCR/APSI_001818/... · 06/11/1985  · --o F X NF __ _ ---SHEET 1 OF 1 a/PM '" Tr

. ' z.s ptpe

• Illusfrale.d l.09 of"' Seism19 lre/!ch Loi 5~ 7?-14631) AlderNood ed ~ Culwod Ed., LR E&%46elh Dlsl-.

/..c; ~ 4n1eles C'oun./y ;",,;o'

./';'// hp /, 5 :_2, o 'rec en .f a//uw~m -red s t'//y :s cl 1e/ C'f /.; b!'n sdo/ s ;;/

. . ' ·. ;/ · -~------~./ ___ j-1,:6"-_-----.--:,; "/'• ;.. ..· . ---~'. .. -~-·-·_ ._-·_·_· :-_~_.:_.:.rSo - _ .::__·: 'P':°,_r:'.f~_.__ "'1_'!x, rf1:___S_!"ft:f,_'C!i1-"'- ~- --:-:--:. ·. : ·. ____ .

.. · · · : · · .· · . · . · · . · · . · . ·. . · ·· · : · · : · · ·.. ·. · • · · · · · -- > Qsw

. ·_·:.: - ·:.. . Q. oaf OoCJ/-t;/cler c;//uv1vm -:~- slope wash · ---· .... f h /.I dt hrn .. st'lly fn-cse __ sd_./ red-brn sJ. renc proT'/1e -

. . , : · 1 1

v/cohes1ve ..-----7 - ... · .. · wer~I~ SZ 9wsfC.

;\/o./-e: No dlsc;ern;b/c /6;u/ls, h-acfures, shears or Asvres 1n Ooe/ o,.. /n so;/ pror;11e

GEOPL-4/V, !!JC : PrPJecl- 56767 8-31-85 _

Page 21: COUNTY OF LOS ANGELES .. AP - gmw.consrv.ca.govgmw.consrv.ca.gov/SHP/APSI_SiteInvestigationReports_OCR/APSI_001818/... · 06/11/1985  · --o F X NF __ _ ---SHEET 1 OF 1 a/PM '" Tr

i ,-

\

PLJJTE 3 ~ ~ ...

Page 22: COUNTY OF LOS ANGELES .. AP - gmw.consrv.ca.govgmw.consrv.ca.gov/SHP/APSI_SiteInvestigationReports_OCR/APSI_001818/... · 06/11/1985  · --o F X NF __ _ ---SHEET 1 OF 1 a/PM '" Tr

lr' ~ •

·~ l

~

('....

~ 'k

-~ ~ -~ ~ \)

ct fl)

~

~ "{ ,. t: • 't

~ c:

~- &g ._

~ \/) I\)

'Ci_ Y-a \l

~~ ~ . .........

IQ

.~ \)

. !;.

ct ~ ~ V r • ~-

Page 23: COUNTY OF LOS ANGELES .. AP - gmw.consrv.ca.govgmw.consrv.ca.gov/SHP/APSI_SiteInvestigationReports_OCR/APSI_001818/... · 06/11/1985  · --o F X NF __ _ ---SHEET 1 OF 1 a/PM '" Tr

0 • -'Sl c,.

111.oe

PLATE 5

~ L,,/ 51 0 0

Q

l J ~ "' I-

&o a so

0 ""-Dll-000 ~ .. ..,

"° M. 8:!• 44.' !•"I!--,o 50 50 so

u ,(7 44 49 50~

0 ~2'.% (io,f.7 ..., . '.., 50 .:

36 0 35 " 34 o~ 2 2 !11

b ., D ""'" "" ..

.Jotl!HUA T~1t£ Dlil.. 0

" 0:,,. .""1 ... .. " ii- '5' ~

17..e~ I 1.71

.,a. .... •

"''""" " I 1-fii.~

N. &:t• '-•,_, .. ~I!.

' T12ACT N 2 14631

...,..llt•H, M i.s:r 4 a11 .. ,, ........ ,5 .., .... 9&"'4"-

1Z

.,o

G£0PLAN, JNC. _ Pr-o/ect 567G 7 8·31·85

This is not a survey of the land, but is compiled for in!'orl!llltion only, nor is it a part of the report or policy to which it may be attached.

Page 24: COUNTY OF LOS ANGELES .. AP - gmw.consrv.ca.govgmw.consrv.ca.gov/SHP/APSI_SiteInvestigationReports_OCR/APSI_001818/... · 06/11/1985  · --o F X NF __ _ ---SHEET 1 OF 1 a/PM '" Tr

.JCHN D. MERRILL. f-JLA It

/1.vL-.1.?dGC- V/.fL~/L-5 Or-,,.L{AX/VL/L/ ./.Jcc.c-LE/2AT/O/../ //.../ ,t?o

f tf::sc/re 1 a~~------.

~· •

~I co. 7 .----..: I

3/

. .

&rereru~e: /.!cc<:"/cr....:;>//on /n rnck r<->r .C-~rrh.-y1.-..:;,k~~ /n rh<:'" W.,.-s.f.:""r/7 Ur7/r.o-nl :5/~rC'.; hy P. r.::.. :5.chr;,...:;;>h~/ ? h'.'6. :5~<="~ /2epnrr .L./o. 7.z-2, C....:;>rrh7-<.-..;;>.l::«3'

_ ,En;:::;;.-h'""c-r/~£:s0C'::.~rch Ccn/c-r, J(/n;v...-rs;ry <:>F C.:j //',t:" nrr: ,,~.,. /? .: r KC' /er, Jun c- • /-:> 7.:Z •