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HomeMy WebLinkAboutCT 79-01; PALOMAR AIRPORT BUSINESS PARK; SOILS REPORT; 1978-10-04l-" • I I GEOTECHNICAL INVESTIGATION FOR ON-SITE DISPOSAL OF SEWAGE EFFLUENT For PALOMAR AIRPORT BUSINESS PARK Carlsbad,· California To PALOMAR AIRPORT BUSINESS PARK 62~ 1 Yarrow Drive, Suite C Carlsbad, California October 1978 PETER A. lENDRUM ASSOCiATES GJG;r~EER;NG DEPARif;'ENT . ,' · .' .... -... : .. ,. · " • • · ~ " '., : ... : -.) .............. '\' ... : .. , . -J . " . , , I I ! it! I' ' l' \ , , , J . ., . l .j .... October 4, 1978 218-12, 23'92 ROBERT PRATER ASSOCIATES Consulling Soil. Foundolion & Geological Engineers Palomar Airport Business Park 6231 Yarrow Drive, Suite C Carlsbod, California 92008 Attention: Mr. Bernard W. Gilmore Re: Geotechnical Investigation for On-Site Disposal of Sewoge Effluent·:-····· Palomar Airport Business Park Carlsbad, California GentJemen: a ln accordonce with your request we have performed a geotechnical investigation of the _Palo~ar Airport Business Park for the purpose of evaluating the suitability of the sub- surface soil, geologic and groundwater conditions for disposing of sewage effluent from septi~ syster:n~ 'utilizing seepage pits. The accompanying repGrt presents the results of our office research, field investigation work, laboratory tests-and engineering analyses. The soil, geologic and groundwater conditions are di"sc::ussed and our conclusions regard- ing the use of seepage pits cit the site are p~esented. If you have any questions conceniing our findings, please call. Very truly yours, ROBERT PRATER ASSOCIATES ~~ 'C:=::-... - Robert Prat~r, C. E. RP:jsr Copies: Addressee (1) Willdan Associates, Attn: Mr. Henry l. Worley (1) California Regional Water Quality Co.ntrol Boord, San Diego Region (12) 10505 Roselle SIreel, San Diego, California 92121 • {714J 453-~ I 6XJ AlIa Visla Drive, Suite 105, Visla, California 9ZJ83 • {714J 758-9144 Letter of Transmittal Title Page Table of Contents INTRODUCTION SCOPE SITE CONDITIONS A. Surface B. Geology C. Groundwater CONCLUSIONS Figure 1 -Site Plan Figure 2 -Vicinity Map TABLE OF CONTENTS Figure 3 -Idealized Geologic Profiles Exploratory Boring Logs 1 and 2 TobIe 1 -Estimated Quantities of Effluent and Evap~tran$piratjon Potential e Table 2 -In-Situ Porosities (n) " ,: Table 3 -Infiltration Test Data Table 4 -" ~Iectrical Resistivity Data APPENDIX A -SEISMIC REFRACTION GEOPHYSICAL SURVEY APPENDIX B -WATER QUALITY DATA Page No. 1 1 2 2 3 3 4 A-1 B-1 INTRODUCTION GEOTECHNICAL INVESTIGATION FOR ON-SITE DISPOSAL OF SEWAGE EFFLUENT FOR PALOMAR AIRPORT BUSINESS PARK CARLSBAD, CALIFORNIA In this report we present the results of our geotechnical investigation of the s\Jbject 330 acre business park located southwest of the intersection of Palomar Airport Rood andEl, . Camino Real in Carlsbad, California. The purpose of this investigation was to evaluate the suitability of the subsurface soil, geologic, -and groundwater conditions at the site for disposing of sewage effluent from septic systems utilizing seepage pits. Our work was directed at supplying the information required by the California Regional Water Quality Control Board in their "Application for Waste Discharge Requirements, Land Disposal. 1\ Our past involvement with the bu~iness park developm~nt has included 1) detailed geo- technical investigations for the existing Phase 1 portion of the business park and for the PT&T improvements along the alignment of Camino Vida Roble within the phase II portion e of the park, 2) earthwork observation and testing services in connection with the initial Phose I mass grading operations and the Phase II PT &T improvements, 3) a detailed geo- technical in.v~stjgation for the phase II portion of the business park, 4) numerous detailed foundation investigations for individu~1 building sites within"-the Phase I portion of the park as well as earthwork observ"ation and testing services in connection with finish grad- ing operations for individual building sites, Gnd 5) the performance of percolation and capacity tests for seepage pit installations on individual lots throughout the phase I area. At this time only a part of the Phase I portion of the park has been devel?ped. Site usage to da~e has been primarily light business/industrial and it is anticipated that the remainder -of the business park will be developed with facilities of similar usage. Based on metered ;""ater usage quantities provided by the Carlsbad Municipal Water District for the-12-month period ending July 1978, it has been estimated that the quant.i~ies of sewage effluent to be disposed of when the park is fully developed will be appro~imately 30,165 and 21,440 gallons per day for Phase I and Phase II, f'espectiv-e-Iy. SCOPE The scope of work performed in this investigation included 1) a gathering and review of all soil, geologic and groundwater information available in our files, 2) a geologic sit,e reconnaissance, 3) the drilling of two deep exploratory borings to establish the depth to e regional groundwater, 4) sampling and water quality" testing of both surface water and - groundwater,S) an electrical resistivity survey, 6) a seismic refraction survey of selected ,! , 218-12 Page 2 areas, 7) a large scale infiltration test on a selected lot, 8) soil ond geological engineer- ing analysis of the data obtained, and 9) the preparation of this report. The data obtained and the analyses performed were for the purpose of pr<?viding more detailed, information on the subsurface soil, geologic and groundwater conditipns with respect to the overall suit- ability of the site for disposal of sewage effluent from septic systems utilizing seepage pits. SITE CONDITIONS A. Surface As indicated on the Vicinity Map, Figure 2, the business park is'located astride the upper portion of Canyon de las Encinas which runs generally from east to west and eventually drains to a marsh about one mile west of the property. The site is irregular in shape with a total plan area of approximately 330 acres. For the most part the topography is moderately rolling with ground surface elevations ranging "from a high of about el.. 320 near the eastern extremity of the site to a low of about el ~ ':.120 near the wE7st end. The northeast portion of the site has been previously graded and several buildings have been constructed on some lots. A low dam and pond which are indicated on the U. S. G. S. Encinitas Quadrangle dated 1968 in the )¥estern portion'lof the site are no longer ,tn existence. The southern abutment of the embankfl!ent has been cpt out, allowing any surface water to flow down the canyon unimpeded. ' At the time of our field investigation there was only a small amount of surface . water in scattered locations on the canyon bottom in the western portion of the site. This tit water resultS from storm run,'off and irrigation on the adjacent hHlsides. Ground surface veS'- etation in the ungraded portions of the site varies frqm a moderate growth of dry grass and weeds in th~ ,higher portions of the site to a very dense growth of brush and trees in the lower-Iying'western portion. In the previously graded Pha~e 'I portion of the park surface vegetation is spar~e on the relatively flat undeveloped lots. However, the slopes have been hydroseeded and numerous trees and shrubs hav~ been planted throughout the developed portion of the area. -' According to "Climates of San Diego County" (obtained from the San Diego County Farm Advisor's office) published by the University of California Agriculture Extension Service dated November 1970 and an insert for page 87 dated April 1977, the evapotranspiration potential for the south coastal, zone, in which the site is located, is 44 . .4 inches per year'! According to Table 8 on page 61 of the same publication, the average yearly precipitation for the nearest reporting station (Vista) is 16.5 inches. Deducting the total prec'ipitatio'~ from the total potential evapotranspiration results in a net pt;tential evapotranspiration rate of 27.9 inches per year. In units of go lions per day per square foot of landscape area, this is an evapotranspiration rate of 0.04765 gallons per day per square foot. Based on this net potential evapotranspiration rate and estimates of the landscape areas for proposed lots provided by Willdan Associates we have computed potential evapotranspiration quantities for the individual lots. The potential evapotranspiration rates thus computed and the ,esti- mated quantity of effluent to'be disposed of on individual lots are presented in Table 1. There are approximately 17 acres of' existing dense brush and trees in the low-lying area west of the proposed Phase I and II developments with an additional evapotranspiration. potential of approximately 36/00~ gallons per day. .J, , ! I '1 I \ I 'I ,I I I i " ,1 I • 218-12 Page 3 As on indication of the existing potential for evapotranspiration in the Phase I area where landscape growth has been established, it is our understanding that an average of 15,000 gallons of water per day was used for landscape irrigation during the year July 1977 to July 1978. ,. According to Department of Water Resources Bulletin 106-2 there are records of 6 wells present within one mile of the park (see Vicinity Map, Figure 2). However, we were un- able to locate the ~ells in the field and it appears that they have been abandoned since the establishment of imported water suppliEfs. There are also no known diversions of surface waters within one mile of the site. . , B. Geology The business pork site is underlain at relatively shallow depths by sandstone af.ld mudstone strata of the Eocene Del Mar Formation which ·exhibit a regional' dip of about 1 to 2 degrees to the southwest. The strata have been m1191y folded with dips locally ranging up to about 20 degrees. The formational materials are generally_-mant-Ied by several feet of fine silty and clayey sands. The upper part of the Del Mar Formation is comprhed predominantly of soft sandstones ranging from 30 to 60 feet in thickness with occasional interfingers of mud- stone. The sandstones consist essentially of interbedded fine grained silty and clayey sands. This sandstone part is underlain by mudstones consisting .of interbedded sandy and clayey silts an.d silty clays which are exposed in the lower portions of the slopes in the higher eastern third of the site. The usually gradational contact between the sandstone and mudstone interval lies at about el. 300 in the northeastern .port of the pr6perty and at about el •. 1.QO in the western extremity of the site. ; 'Porosities for the dominant sandstone upper part of the Del Mar'Formation were determined by means of in-situ density measure'ments at seyeral locations across the site. The results of the tests and computed porosities are summarized in Table 2 and if.ldicate on overage porosi ty of 0.38. . The results. of seepage pit capacity tests which have been performed at the site are sum- marized in Table 3. In addition, in-situ permeabilities were computed for. the typical on-site formational materials utilizing the seepage pit infiltration data. The data indi.- cotes an average permeability of 0.3 feet per day for the dominant sandstone port of the Del Mar formation. 'e:::=or· - c. Groundwater Two deep exploratory borings (B-1 and B-2) were drilled in the lower-lying portions of the site at the approximate locations indicated on the site plan and slotted plastic pipes (piezometers) were installed to establish and monitor the depth to the regional ground- water table. logs of the borings are enclosed following Figure 3. The groundwater depths in the borings were m~asured on July 28 and September 23, 1978 and indicated depths of approximately 24.9 and 24 .4 feet, respectively, in Boring 1, and 20.0 and 21.6 feet in Boring 2. The gradient of the existing ground surface as well as the indicated water table surface between the two borings is approximately 0.014 feet per foot. " .218-12 WPage 4 tin order to more accurately define the subsurfoce soil, geologic, and groundwater con- aitions underlying two"' narroW portions of the canyon, a seismic refraction geophysical, survey was performed. The approximate locations of the seismic refraction traverses are indicated on the site plan. The results of the seismic refraction survey are presented in Appendix B. Utilizing the additional information provided by this work two idealized sections were developed for the narrow portions of the canyon at the locations indicated on the site plan. The idealized sections are presented on Figure 3. As the refraction survey indicates there is 0' fJlegligible thickn~ss of alluvium on the canyon floor which has been carved into the !saft sondstone of the Del Mar Formation. The seismic refraction traverses indicate a relatively flat free groundwdter surface (which is non-conformable with the ground surface configuration) that extends through two distinct seismic wave velocity layers into the hills comprising, th~ sides of the canyon. The flow of groundwater to the west is therefore taking place in a wide band of forma- tional soils and is not confined to a narrow zone 'of alluvial soil in the canyon bottom. Groundwater has been encountered in 10 other borings.drilled at the site. These test holes are numbered 3 through 12 on the site, plan and the corresponding groundwater elevations are denoted next to the boring locations. The groundwater encountered at the higher elevations in the north~rn portion of the Pha'se I area (Lots 2A and 2:B) does not, in our opinion, represent a free gro'undwater condition of large areal extent. The ground- water encountered in the borings is probably indicative of isolated pockets of entrapped _water. This conclusion is based on the fact that groundwater was not encountered in all the borings drilled in this portion of the site and the groundwater elevations varied sub- stantially i.r~ those bOfings wh~re it was encountered. ' The entrapped water encounte~eCJ 'in some of the borings on Lots 2A and 2B raised some concern about the ability of the subsurface soils to dispose of large quantiti,es of effluent. Accordingly, a large scale, infiltration test was 'performed in one of the capacity test holes subsequent to which the level of .water in ,10 surrounding capacity test holes was measured. The locations of the infiltration and 10 observation holes are indicated on the site plan. On July 27 pnd 28, 1978, 210,000 gallons of water were pumped into the infiltration test hole. Me'asurements made in the 10 surrounding holes just before and approximately 60 days after the water had been ~niected showed no difference in the depths to groundwater thereby indicating that all the water had drained from the area. Therefore, it appears that there is no lateral confinement in the subsurface soils to prevent the disposal of large quantities of effluent. .~ ... - CONCLUSIONS Based on the results of this investigation it is o'ur opinion that the site is in general suit- able for the disposal of sewage effluent by septic systems uti tizing seepage pits. More specifically, it appears that the estimated 51,605 gallons per day of effluent for the phase t and Phase II portions of the business park can be suitably disposed of by a com- bination of subsurface seepage and evapotranspiration. However, since our work also "218-12 • Page 5 indicates that there are random isolated areas of relatively impermeable soils across the sit~, the suitability of individual lots for disposing of sewage effluent utilizing seepage pits should be determined on the basis of seepage pit jnfiltratian tests performed on each lot. J - We anticipate that "most, if not all, of the effluent disposed of into the ground will be lost to evapotranspiration. Based on our knowledge of the subsurface conditions, it is anticipated that subsurface seepage will generally follow the bedding-of the subsurface soils resulting in evapotranspiration losses on individual lots from planter areqs and land- scaped stopes~ Any deeper seep?,ge that ~ight pass through the lower-lying portions of the Phase I and II developments "is expected to be lost to evapotranspiration in the heqvily vegetated l7-acre area west of Phase II. Although evapotranspiration rates ore subiect to substantial seasonal fluctuations, the large storage capacity of -the voids within the soil will, in our opinion, handle effluent that is not lost by evapotranspiration during the winter months. Based on our evaluation 6f the properties of the soils-underlying fhe site, we estimate that a lO-foot depth otl:lnsaturated soil above the groundwater table will be capable of storing approximately 6-years of effluent, even with the conservative assumption that all effluent will be retained in the ground and no effluent will be lost by subsurface flow out of t~e area or by evapotranspira~ion. "~ ........ 1: ,J-U! DJ.,,/ (/'. Pt~·-····· e ; q~ -:t l, . ... .,.. ... ...:.' """ : . .,.~ -:1--~ .f;:-/ .f" --." , o't. .• F .. ' : :: ;' . ~''''' • • • # . .,... ., •• ,,_/1. )' -. ,: ,. i " : l 1 . \ r.··lit LEGEND o Indicates approximate recorded • Approximate Scale '"",._. (tholJ}~md5 of feet) F o 1 2 4 well locations within one mile of site. Bose: U. S. G. S. Encinitas and San Luis Rey Quadrangles, 7.5 Minute Series (Topographic). ROBERT PRATER ASSOCIATES Con,v".np SO". fovndor.on t Geo'o~.col fn~.neerl VICINITY MAP PALOMAR AIRPORT BUSINESS PARK Carlsbad; California 218-12 DATE PROJECT NO. Figure 2 October 1978 DRILL RIG Mobile B-61 SURFACE ELEVATION 192.rox) LOGGED BY RJB DEPTH TO GROUNDWATER See Note BORING DIAMETER 8 Inches DATE DRILLED 7-12-78 ZIlJ~ -; W e.~ x DESCRIPTION AND CLASSIFICATION Qut . :rZ e a: ... Z ....... 0:;:-a: ::; ~ _ ~~::;~ DEPTH w oJ «Cf) W z <zo:"-"-wz n. :::n~ !<~ wwo'" za:w ISYM-SOIL (FEET) ::E w-o ~z ~a::l-~ On. a: DESCRIPTION AND REMARKS COLOR CONSIST. < z~....J u::E1- BOL TYPE Cf) ~a:e 0 1->-ZoCf) 0 Cf)m =>0 SILTY SAND (SANDSTONE) brown medium SM :---dense r--to dense r-... f-- f-lO - I I--.. I .. .. I-- I-- 1-. - ·20- CLAYEY SAND (SANDSTOt;.lE): brown medium SC I-- dense f----to dense .. I--. I-- 30 : , I-- 1- SANDY and CLAYEY SILT Igreenish hard ML I-- (SILTSTONE) igr~y : f--- i I--e f-40-; I-- .. : I---. . , . ! ! I-- I-- I-50-: I-- SILTY CLAY (CLAYSTONE) blue hard CH I--.. . green I--. -l- I-60- : I-- f-- I--.. p'_. f----- I-70-, I-- I-- f-- I-- I (continued) I-SQ-. e EXPLORATORY BORING LOG I ROBERT PRATER ASSOCIATES PALOMAR AIRPORT BUSINESS PARK Con''''"np So,I. FOllndolton t. Geolog,col f ng,ne.,1S .. Carlsbad, California .. I PROJECT NO. DATE 218-12 Oc tober 1978 BORING 1 NO. (pg. 1) "'~~-JlI~~~~~ __ ~~ . .. .. ~"'W~~"""'mT>l!llI6:M' ------. Mobile 8-61 192~ DRILL RIG SURFACE ELEVATION LOGGED BY RJB - DEPTH TO GROUNDWATER See Note BORING DIAMETER 8 Inches DATE DRILLED 7-12-78 zw-"': . UJ 0'" DESCRIPTION AND CLASSIFICATION 2 0 1;: . ;i:Z w>::I: ,a: I-Z, a:-a: ::; ~ _ ziijl- '. DEPTH w ~~'" wI--enC1-...l ...z <zo:"-"-wZ"-... :; ~~, <w wwoen za:w lll !SYM-SOil IFEET) ::!: ~lZ ~a: ... ~ o ... a:~ DESCRIPTION AND REMARKS COLOR CONSIST. < z~..J 0 1->-0::!:1- BOl TYPE '" ~a:!!!. z 0'" ' 0 "'[I) :;)0 SILTY CLAY (CLAYSTONE) blue hard CH r--: qreen '- SANDY and CLAYEY SILT dark hard ML I-- (SILTSTONE) gray --. I ~ 90 - I --., I , .. i j I-- I I--, I t-- 1-100- j , t--: 1 ! ~. -i . -. • -0 i ,-- 0 I -- I -110-! .. -: -: ..;. ( , 0 f-: -e l-f _ i r-11o- ; l-" -I : I 1 '-- I • 0 -~ ,--, I I Bottom of Boring = 128 Feet -130 -I , ' . -I l- I 0 o. f-, - Note: Slotted plastic pipe (piez:" -. t- o om'eter) installed in boring I-- after drilling. Depth to I-- groundwater measured on I-- : July 28 and September 23, I ,-- 1978 at approximately 24.9 I-- and 24.4 feet, respectively. ""'.~ i--.., - I-- I-- 0 I--, I-- I--Note; The stcgtificalion lines repre>ent the apP",,!,!,,,,,t. boundary between malerial types and the Iransitian may I--"- i e be "",dual. . EXPLORATORY BORING LOG ROBERT PRATER ASSOCIATES Consuhmg So,l, FoundOhon & Geologlcol Eng,,!eers PALOMAR AIRPORT BUSINESS PARK. Carlsbad, California t-_P_R_O_JE_C_T_N_O_, _+-___ D_AT_E_-'---I BORING 218-12 ()ctober 1978 NO, 1 (pg. 2) , , , I I \ , :~, ~ I ! I . . DRILL RIG Mobile 8-61 !; SURFACE ELEVATION 137 (aFtix) .LOGGED BY RJB DEPTH 10 GROUNDWATER See BORING DIAMETER 8 Inches DAlE DRILLED 7-12-78 z ...... . w If' DESCRIPTION AND CLASSIFICATION ~ut: . :tZ r:c 'a: -D'EPTH .... t-z ...... wI-r:c :; ~ _ :z <:) -' " I~~t DESCRIPTION AND REMARKS CLAYEY SAND SILTY SAND (SANDSTONE) . " Note: Slotted plastic pipe (piez- ometer) installed in boring after drilling. Depth to : groundwater measured on July 28 and September 23, 1978 at approximately 20.0 21 .6 feet, respective Iy. . -. . , " .. , ' (grading gravelly) _.-. -. - .. Bottom of Boring = 67 Feet Note: The stratification lines repre,en! ,he approximate boundary between material types and ,he 'mnsi!"", may be ",aclval. ROBERT PRATER ASSOCIATES Cor-sulflng So", FoundOhon & Geolog.col Engineers COLOR ~~ffow- Ish brown reddish brown I I . -. " , ,light brown . ; -' «II) I-Z <za:lL Q. ::~~ <'" "'woll) SOil (FEET) :l: .... -0 ~~ ~r:cl-~ CONSIST. < z~-' 0 1->-TYPE ." ~a:~ u II)m .~:~~ium ense sc I-- I--- I-- medium SM '-- dense -10 - to dense I-- I-- I-- I-.~ ~20- -... --, I---I-- I-30 - ., r-- I-- ,... - ,.. - f-40 -"- I--. l--.-. I-- ,.. - I-50 - ,.. .... ',' I--. I-- I--, 1-60- I-- I-- I-...; . "" .. -:;;: c-70 - -- -- -- -- -- EXPLORATORY BORING LOG PALOMAR AIRPORT BusiNESS PARK Carfsbad, California t-_P_R_O_J_E_C_T_N_O_._-+ __ ---,DA_T_E __ ~ BORING 218-12 October 1978 NO. 2 wZlL r:c w'" Q.a:~ :l;t- 0'" u • I i I' !, . I l • t j, -j • 218-12 TABLE 1 ESTIMATED QUANTITIES OF EFFLUENT AND EVAPOTRANSPIRATION POTENTIAL AvaiJabre Estimated landsc,ape Evapotranspiration Effluent Area Potentiar Lot No; (gals/day) (ft2) (gals/day) 13 2,855 135,070 6,436 ' 1 1,533 82,927 3,951 2A 4,592 250,148 11,920 2B 2,384 .. 128,562 6,126 4A 1,476 ',' 37,652 1,794 '-.' .. 4B 1,167 62,241 2,966 6 1,672 89,086 4,245 7 1,821 99,48:1 4,740 10 : 1,606 46 644 2,223 , , i ' 12A f 1 098', 165,678 7,895 I ' , 128 Resub - 1 861 44,872 2, 138 I e -2 : 1,234 65,400 3,116 [ -3 545 27,50) 1,310 -4 545 27,501 1,310 I ' :., 5 ; 1 004 52,767 2,514 I , , I -6 861 44,872 2,138 -7 344 16,449 784 I -8 861 " 44,872 2,138 1 I -9 603 30,661 1,461 -10 603 ' 30,661 1,461 -11 373 18,028 859 "-12 373 18,028 ' , ,859 -13 344 16,448 784 14C 1,390 110,015' 5,242, 18 Resub - 1 -643 32,871 1,566 -2 651 ' 33,345 C;:::-..... -1,589 -3 649 33,187 1,581 -4 672 34,450 1,642 -5 826 42,978 2,048 -6 841 43.,767 2,085 -7 781 40,450 1,927 -8 738 38,081 1,815 -9 6'89 35,397 1,687 -10 8M 43,924 2,093 (continued) • • 218-12 TABLE 1 (Cont.) ESTIMATED QUANTITIES OF EFFLUENT AND EVAPOTRANSPIRA TI ON POTENTIAL Available Estimated landscape Evapotranspiration . Effluent Area Potenti':1l Lot No. (gals/day) (ft2) (gals/day) 18 Resub -11 772 39,976 1,905 -12 1,171 61,926 2,951 -13 1,096 57,820 2,755 -14 430 21,·186 1,010 -15 1,254 66,505 ~,169 -16 961 50,398 2,401 -17 947 49,609 2,364 -18 1,406 74,874 i3,568 -19 1,214 64,294 :3 064 . , . 16 Resub - 1 803 41,714 ~ 1,988 -2 522 26,240 : 1,250 J e -3 611 31,134 ·1 484 . , -4 422 20,712 ; 987 -5 511 25,608 1,220 -6 344 16,448 784 -7 344 16,448 784 -8 344 16,448 784 17 ·398 25,290 ... 1,205 (;::;::: ... - ·e Lot 16 Lot 16 Lot 16 Lot 16 Lot 13 Location Future Development Area Future Development Area Future Development Area Lot 18 • TABLE 2 IN-SITU POROSITIES (n) In-Situ Dry Density (pef) 104.9 '. 103.8 108.0 109.3 103.7 104.2 98.3 -'. 98.0'-" . 98.3 In-Situ Moisture Content (%) 9.4 11.7 11.2 8.6 17.3 16.9 13.6 14.6 20.4 218-12 Porosity,n 0.36 0.37 0.35 0.34 0.37 0.37 0.41 0.41 0.41 • 218-12 ' ! I TABLE 3' ~ -~i INFILTRATION TEST DATA Measured Capacity Test Hole I nfil tratj on Rate Per' Pit . Lot No. Depth (Feet) (Minutes/Inch) (Gallons/Day) Lot 2A-A 50 .. 1.5 7,337 " -8 50 ' 5.0 2,270 -C 35 2.1 5,472 -0 44 0.8 14,500 -E 43 0.8 13,748 -G 49 0.5 24,125 -H 50 0.5 24,000 I -J 25.5 1.6_-7,171 I I ' ! -K 46 0.4 28,320 -M 5~ 7.8 1,454 -N 50 0.9 11,904 -0 46.5 0.4 31,632 -P 30 6.8 1,652 e -R 36 0.5 20,592 -S 47 0.6 19,824 -T, 39 0.4 30,912 -V 40 0.8 13,392 Lot 6 ' 57 0.4, 28,000 Lot 7-1 55 ~', " 3.3 3,456 -2 40 2.2 5,04p Lot 8-1 50 21.4 528 -2 50. 78.3 144 -3 54 19.6 5(6 -4 56 5.0 2266' , -5 50 6.7 .l::::;::!. .... -1,690 Lot 12 Resub-H-3 50 3.9 2,906 -H-7 51 3.0 3,758 -H-9 51 0.5 22 344' , , -H-11 55 0.3 41.,952 . Resistivity Line No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17.· • '218-12 TABLE 4 ELECTRICAL RESISTIVITY DATA .' ". location lot 2.4 I lot 28' Lot 2B Lot 2A lot 2A Lot 8 Lot 8 Lot 8'·'> Lot 5 lot 4· ',Lot 12 Resubdivision -Lot 3 , . Lot 12 Resubdivision -Lot 5 ~ .. Lot 12 Resubdivision -Lot 9 Lot 16 lot 18 Lot 18 ; Future Deve topment Are.a Resistivity (ohm-meters) .(::::: .... - . 39,150 12,600 58,000 41,800 47,000 7,220 .4,560 2,720 3,000 4,050. 24,000 2,415 1,710 1,710 27,000 17,000 57,000 . I i • • APPENDIX A SEISMIC REFRACTION GEOPHYSICAL SURVEY • e::::: ...... - I \ , . T. FUNNEKOITER I1EGIS1EREQ GEOLOGIST C£~TlfIED ENGINEERING GEOLOGIST P. O. SOX S7S • ESCONDIDO, CALIF. 92025 7..(6-2793 .-=NGINEERING GEOLOGY Robert Prat~r & Associates 11585 Sorrento Valley Rd Suite 101 San Diego,Calif •. 92121 Attn: Dave Hespeler •. I .. Dear Sir, • SEISMIC INVESTIGATIONS For Suhdivilion Oelign Pipelines • Roods Sehmlc Rippohility Studies August 28,1978 Enclosed is the Subsurface Investigation Report of the Palomar Airport Business Park. A total of 1900 lineal feet of:Seismic line was run on the site. Flagging was placed at all locations at the ends of the lines. Very truly yours, T. Funnekotter t== .... - ... T. FUNNEKOTTER RfGISlERED GEOLOGIST CERTIFIED ENGINEERING GEOlOGIST • O. BOX 575 • ESCONDIDO, CALIF. 92025 7046·2793 E.INEERING GEOLOGY, SUBSURFACE -lNVESTIGATION PALOMAR AIRPORT BUSINESS PARK SAN DIEGO COUNTY;CALIF. AUGUST 28,1978 ~.,.-- .' SEISMIC ,INVESTIGATIONS For Subdiviliol1 Design Pipelines • Roods Sehmlc Rippobility Sludi., , T. FUNNEKOTTER REGI!>TERED -GEOLOGIST C[RllfIED ENGINEERING GEOLOGIST • O. BOX 575 • E!>CONDIDO, CAUF. 92025 e 7"'6·2793 PURPOSE: l~lETHOD: DISCUSSION: E.INEERING GEOLOGY • • SEISMIC INVES-r:IGATIONS For Svbdivision Oe.ign Pipelines • Roods Seismic: Rippobllity Slvcliel 1 • To evaluate subsurface conditions along select l~nes of.a proposed develop~ent in order to provide inro~IDationlas to the velocity, configuration and number of the sedimentary strata within a specific drainage system. Geologic reconriaissance. Refraction Seismography. . .; -.. The site is, 'just s,?uth of Palomar Airport in low rolling hills in a mildly dissected ,sedimentary area •. The compos,ition of the site is principally silty and clayey -sands, siltstones and shales'. Eight Seismic traverses 1.;ere run on the site principp.lly to acquire a-velocity cross section -.1J.ormal to the cree~. bed approximately 500 feet in . both directions. These ,lines are located approximat- ely as shown on the enclosed maps and are labelled lines A thru H. In area 1 are lines A thru D, and H -in area 2 lines E thru G. Line A was run southeasterly from Pizo 1 for 500 ~".- .feet. Four distinct velocity layers were located here, i.e., 1200 to 1400 ft/sec .from 3 to 7 feet deep, 1800 to '200q ft/sec from 20 to 29 feet deep, 3300 to 3600 ft/sec from 35 to 63 feet deep, .. and , . a velocity of 5200 to 5300 ft/sec at ,thi$ lower depth. , q". FUNNEKOTTER RfGISlERED GEOlOGIST CERllFIED ENGINEERING GEOLOGIST O. BOX 575 • ESCONDIDO, CALIF. 92025 e 7.c6·2793 DISCUSSION: E~EERING GEOLOGY • SEISMIC INVESTIGATIONS For Svbdivilion Delign Pipelines -. Roods Se~mlc Rippobility Studies On the north side of the creek four 200 feet runs were made but are not continuous because much of this area is·loose fill material with high soft . I . I embankments .!. the Seismic lines were positioned. to avoid this material. which is extremely absorbent of shock waves. Lin~ B is, for the most part, two velocity zones, . ': ~. ;. ... 1400 ft/sec and 5200 ft/sec -the 1400 ft/sec mat- erial is 26 to 33 f~et deep. Li'ne H is just north of B and has three velocity , zones, i.e., 1700, 3400, and 5200 ft/sec -the first layer is 17 to 28 feet deep, the second layer from 28 to 41 feet deep. Line C is also a,three layer situation 1400 ft/ . sec to 12 feet, 3200 fi/sec from 42 to 45 feet and at this lower depth 5200 rt/sec. Line D -1600 rt/sec to 20 f~et,'3200 ft/sec frOm 44 'to 54 feet, 50QO rt/sec at the lowe~ depths. The end of line D is approximately~OO feet northeast of Pizo 1. Lines E thru G are in area 2 -line Ewas run on the high voltage line access road -here three velo- city zones were measured -1100 ft/sec to 6 feet,- 1500 ft/sec to 22 feet, and 3100 ft/sec to a maximum 'depth of penetration of 49 to 51 feet. This means I , T. FUNNEKOTTER REGI51ERED. GEOLOGIST CERllFIED ENGINEERING GEOLOGIST • O. BOX 575 • E5CONDIDO. CALIF. 92025 7-46·2793 DISCUSSION: CONCLUSION: • INEERING GEOLOGY •• SEISMIC INVESTIGATIONS For Subdivioion Deoign Pipelines • Roods Seiomlc Rippobility Studiel 3 that the lower layer could extend considerably deeper, but this is unknown. Line F is !'lear the creek bed -here was measured , ' I 1100~ft/sec! to 7 feet, 1700 ft/sec to 27-29 feet, and 5000 ft/sec at this lower depth. Line G was run on the north bank of the highviay. Four velocity 'zones were located here -1600 ft/sec to 7 feet, 2100 ft/sec to 27 feet, 3200 ft/sec to 59 feet, and 5000 ft/sec at 59 feet. Three primary velocity'zones were located, i.e., ! 800 to 2100 ft/sec, 3200 to 360~ ft/sec, and 5000 to 5300 ft/sec. The upper layerts) is loose' soil, alluvium, and moderateiy consol~dated silty and ~layey sands. Many, ,runs indicate two velocity bands within this upper group; however since the lines were run over areas of fill, more or less compacted, loose disturbed areas, dirt roads (~ildly compacted) this variation,is expected. The' second layer is a distinct velocity change -it was found on all runs C:;::-c -- except those runs near the creek bed' ( B, and F).' The 5000-5300 ft/sec velocity was measured on all runs except line E • • It is probable that the 5000 rt/sec "layer" is the water table for the following reas<?ns:, it is at a low inclination and non conformable to the . surface, 5000 ft/sec, is typically water velocity, ang, Pi~9 1 encountered groundwater at 33 feet. , T. FUNNEKOTTER 'EG IS 1 E RED -GEOLOGIST CERTifiED ENGINHRING GEOLOGIST p. O. BOX 575 • ESCONDIDO. CAUF. 92025 7.46·2793 CONCLUSION: E.INEERING GEOLOGY SEISMIC INVESTIGATIONS For Subdivision D~llgn Pip~l1ne, • Rood, 5eiomlc Rippobility Sludi", 4 However this does not-preclude the possibility that the 5000 ft/sec "layertt could be a lithologic change. An addit'ion~l conclu~ion can be drawn on the above I water table premise, i.e., that the 3200-3600 ft/sec layer is a porous medium since the 5000 ft/sec v-elo- city was measured within this medium and not on top of it. Additional ~Qrings couid decide this premise with-more certainty. For additional Seismic information, see attached sheets. As a comparison of Uhardness"of sandstone and: granite,rippability bec0mes difficult in granite! at 5000 ft/sec, however in sandstone this upper lim- it is over BOOO ft/sec •. -' Submitted by T. Funnekotter , T. FUNNEKOTIER REGISTERED 'GEOLOGIST CERTIfiED ENGINEERING GEOlOGIST EAINEERING GEOLOGY • • O. BOX 575 • ESCONDIDO, CALIF. 92025 e 7~6·2793 SEISMIC RIPPABILITY INFORMATION SEISMIC I~VESTIGAT'ONS For SubdivisIon o.."gn Pipeline. • Rooc! • SeiJmlt Rippobill~ Siudlu The following points should be considered when evaluating Seismic information: I 1. All velocities, depths, ahd thicknesses are averages and qualified as follows: G good F fair P -poor VP -very poor ? -questionable Grades of G, F, and P should be considered reliable; VP and? should be considered as indications only. 2. Each profile provides information in the immediate area of that profile -extrapolation outward from this line must be considered ,speculative. In other words a velocity cross section is given along a specific line of investi- gation -10 to 20 feet from this line the conditions could vary. In order to avoid any surprises between the Seismic lines additiortal Seismic lines would be in order. 3. As'the velocity of material increases~' ripping becomes progressively more difficult until at some point it is more economical to drill and shoot the material prior to excavation. Rippability also varies with the type of material; however', in general, D-9 Ca't single ripper per- formance, should be ',as follows: rippable to 5000 ft/ sec, marginal from 50qO to 5500 ft/sec, 'and non-rippable over 5500 ft/sec. The changeover from a ripping to a blasting operation usually occurs within the marginal zone~ To determine rippability is essentially an economic decision -whether to continue ripping at higher velocities or to blast at lower velocities'· depends on the type' of job, type of equipment, expertise of the opefato~~, amount of excavation, how the rock is to be disposed of, time factor, etc. For example, in fractured rock a trench type of operation is more .difficult than a hillside job, especially if boulders are present. In a trench manuverability of the heavy equipment is limi~ed and rock disposal is a bigger problem. . . The degree of fracturing is a factor in determining rippability, i.e t • more fracturing, lower velocities, easier ripping. The same velocity could represent either decomposed or fractured rock. · T. FUNNEKOITER E4t'INEERING GEOLOGY SEISMIC 'INVESTIGATIONS For REG ISH RED GEOLOGIST CERTIFIED [NGINHRING GEOLOGIST Svbclivillol'l o".igl'l Pipelines • Roods O. BOX 575 • E!>CONDIDO, CALIF. 92025 7 .. 6·2793 , Seis.m1c Rippchllity Slvdi .. 4. SEISMIC -RIPPABILITY INFORMATION Boulders are identified many boulders (ME), a~d notations can also mean boulders are considered and even possibly to 30 as scattered boulders larg~ boulders (LB). hard angular blocks. tJ be over' 10 feet in feet'in diameter. (SB), These Large diameter 5. For trenching operations, the rippability figures must be adjusted downward, i.e., velocities as low as 3500 ft/sec may indicate difficu~t ripping depending on the degree of fracturing of the rock. Fractured rock and even small boulders can o_e very troublesome in a narrow trench. For example, decomposed-granite is easier to dig than fractured granite even when the velocities are similar. However, in gen'eral, based on a machine com- :parable to a Kohring 505, most materials with velocities' ,of approximately 3800 ft/sec or less should be rippable, over 4300 ft/sec non-rippable, and marginal in between. :In a narrow trench a condition of'many boulders can be :alrnost as troublesome as solid rock so the above figures -should be used with discretion. -- ~ ...... " I I, , I ! , i :1 'I' 1, i i'l j, , . '. '. '. -: " .- . '- " , -.... - • -tF-. .-' ... :-: ~ .' ~ .. 1 • -! t I • APPENDIX B WATER QUALITY DATA • Samples of the existing groundwater at the site were obtained from Borings 1 and 2 in which piezometers were installed. A sample of surface water was obtained in the canyon bottom near Boring 2. The resul.ts of chemical analyses of the water samples are presented on page B-1. Test r~sults nuniber 1 and 2 are for the samples obtained from Borings 1 and 2, respectively:~ Test reSult n.umber 3 is for thesurfoce water sample. Chemical analyses of the imported water source for the Carlsbad Municipal Water Dis- trict were provided by the District and are presented on page B-2. e:::= ......... II· if I' I' . (CLARKSON CHEMICAL LABORATORY) ANALYTICAL AND CONSULTING CHEMISTS :11150 TRDUISDALIt DRIVI: CHULA VISTA, CAUI'ORNIA g:lOID tSTA"LISHtD II'Z. r-Robert Prater Associates 11585 Sorrento Valley Rd. Suite 101 DATI:: August 31, 1978 San Diego, CA 92121 " P.O. # L LABORATORY NO. vl-8704 SAMPLI!:: AS RECEIVED: ThI;ee 'Water Samples, Designated as #1 P ABP P-l Ground water, #2 PABP _P-2 Ground water, #3 PABP I ~. -C kG' d -,'" • _.,': _::_,:.t:.:::'..~.:; ree ~" roun water. ANALYSiS: . {On. Til ter.ea::,Samples) Total Dissolved Solids ~loride Nitrate None Detected less than Iron Manganese Methylene-blue-active substance Boron Odor ; . -.: -;-":, #1:- 950 ppm 195 ppm 73 ppm 15 ppm 185 ppm 62.2% 360 ppm .2, ppm ".2 ppm .29 ppm ~. __ *.1 ppm .28 ppm None 4Ifotal Nitrogen Total Phosphorus None 'Detected less than *None Detected less than '#2 1026 ppm 78 ppm 44 ppm 17 ppm 185 ppm 69.1% 520 ppm .2 ppm 2.0 ppm .2S ppm *.1 ppm .24 ppm None #3 1418 ppm 284 ppm *.1 ppm .07 ppm .8 ppm .18 ppm 90 ppm .2' ppm \ j' 1.1 I ", I, :: ----6"" •• i~ ..... .i~u ... u ..... -rr .. ';.;;. UU .... V tV" • ",-"'-'-;';-(j"f(--a:r'['-l '"C,-t\r Jtni. COHSTITU~HT JUL AUG T OCT ~ DBC ~ rED I MAR Silicn (S 2) 8.4 8.2 .8_._6_ 8.1 __ 8.3 _t·LB_l~oJ_9.J ___ 9 .. 1 APR .I Iron (Fe) I NR I NR I NR I NR I NR IJ-lR._LNR 1 NR 1 NR Cnlcium (Co) I 80 80 .136 I 77 76 Ll_9_LBl LRO 1 R? Mngl1enium (Mg) 1 .. '31 .• _01 30 I 30 129.5J_3.~OJ 30.0 1 30.0110.0110.0 So cli urn (N.) J 103 104 102 1021104 1102 110~ 1103 I' 101 Potassium (K) I 4.5 4.4 4.54.4 ~ __ 4._6_._~.] __ ~.L .. 4.5 4.5 Ca rbona te (CO J) ,I 0 I 0 I 4 I 0 I 0 I 5, I 0 I 0 I 0 Bicarbonate -(HC0 3) 1 156 I 153 I 104 1 148J145 1.142 1 155 1 155 1 160 Sulfa te (SO 4) I 289 I 284 I 281 I 281 I 281. 1 285 __ L29L 1_285_ 1 ?Rb tChlOiide (C1). 'I 89 I·n 193 188 I 90 192 In 88 az. I . , Nitrate" (N0 3) "O~ _QJ_~O O~ 1 0.2 0.40.3 0.3 0.2 Fluoride (F) , O. 25 LJh)~6-'--J)-,_~L~3_'LI~. 34 I O. 34 ~321 0.3 'I 0.29 noron (n) I NR 1 0.14,1 NR I NR ' I NR J:NR INK 1 fh"'121 0.11 Total Dissolved Solids Hard ness as CaCa 3 Total Carbonate Nonca rbona te R _6J3LI 680 I 669 j' 665 U61J 67-7, 1_6_9_6 1_.6i8.L 67a 327 1 323 I 313 I 314 J~J.1J _321 .318 1 __ .1?~ 'I 3?P. _:L~~I ____ ~l_1~LI .. 12J.-'_:L.19 __ 1 ).24 12711271111 _19_LL.llLl1.92.:.--' . J.9J J ____ 19_ 4.1 19 7 201 1 196 1 197 J Alkalinity-Phenolphthalein : '0 0 3 0 0 40 0 Jl ~ I-, Alkalinity-To tal '128 ,125 121 121 119 ,124 127 127. 131 ' Free Carbo~ Dioxide (CO 2) "'. 1 2 l' 2 l' '1 III I Color 1 NR I NR 1 NR 1 NR 1 NR I NR \ NR 1 illI 1 NR 1 I"Turbidity (JTU)' 1,1L·~1,1. ~O.6 : 1.5 : 0.9 '.1.0 ~1,4 '_'O,57~' o.~, Ilyd~ogen Ion-Concentrat:ion-(pB)' I 8.331 .a.13! a.A4Ia.lal ~,-3.Q1.8.2918.351 IL1111 A.11 E1~ctrical Conductivity (ECXlO b @25°C) . 'I 1050 ! 1040 110'L0_1J..D41LL1040_!1050_1-.l070L1.060. 11050 Total Sus.pended Matter t, 697 I 698 \. 692 707 1,685 jNR' 1 714 I 706 '\ 71d J , J /.J IIrAppro",llOately equal to patts per million NI\-No,t [1.epo.l.'ted ~ ---~-- ., . . / . ttl I "?I ,_. . .•. -._----."-'-'------._-_ .... ------.. ,-.•. , ---."----'. . .. --' , .. -:.:-. --~ .. =.;..:::.::..;,;;;-~. ;;;;;;;==~==============