The URL can be used to link to this page

Home My WebLink AboutCD 2017-0003; Kaiser Carlsbad Parking Lot Expansion; PRELIMINARY SOIL INFILTRATION TESTING AND PAVEMENT STRUCTURAL SECTION REPORT; 2017-05-10I ::,";~~ Y RMAGroup Every Proj~cl Matten1jwww.rmocompanies.com May 10, 2017 Hanna Gabriel Wells Architects 1955 Bacon Street San Diego, Ca 92107 Attention: Randy Hanna, AIA Principal RECORD COPY S)Z1t_ /M.gl Initial Date RMA Project No.: 17-0497-01 EC VE Subject: Preliminary Soil Infiltration Testing and Pavement Structural Section Report , ,Y ! G 2017 Kaiser Permanente Carlsbad Parking Lot Expansion 6860 Avenida Encinas Carlsbad, CA LAND DL\ E ._opr\ ~NT -NGI. ~ G Gentlemen: In accordance with your request and authorization, we have completed an infiltration testing and pavement investigation report for the subject site. The report includes the results of four exploratory borings and six soil infiltration tests, along with infiltration system and pavement section design recommendations. Tbe infiltration tests were performed using a Double-Ring Infiltrometer (ASTM Test Method D 3385). This report was completed based upon the requirements of City of Carlsbad BMP Design Manual and Technical Guidelines for Geotechnical Reports. It is our understanding that the project includes tl1e parking lot expansion and installation of two biofiltration basins. According to a Preliminary Parking Layout map, two lined biofiltration basins are planned on the west side of the site and will be connected to an existing storm drain. The basins will range from 1 to 3 feet in depth below design grades. The location of the proposed basins are shown on Figure 1. Site Description and Proposed Usage The site is located at 6860 A venida Encinas in the City of Carlsbad, California. The site is bounded by an auto dealership to the north, Interstate 5 to tl1e east, a residential development to the south and A venida Encinas to the west. The proposed parking lot expansion area and biofiltration basins are currently landscaped witl1 small shrubs, palm trees and a few other trees located west of the existing building. Subsurface Exploration and Earth Materials The four °'l'loratory borings and six infiltration test locations are shown on a site map provided by Hanna Gabriel \Veils Architects and were completed within 50 feet of the proposed BMP's in order to characterize the soil conditions beneath the site (Figure 1). The exploratory borings were extended to a depth of 16.5 feet The infiltration test locations were excavated to depths of 1 foot in the proposed parking lot area and 2 to 3 feet witllin the proposed biofiltration basin locations, corresponding to the depth of the basins in the area of tile tests. Based upon regional mapping by Kennedy, M.P, et al (2007) the site is underlain by late to middle Pleistocene old paralic deposits. The paralic deposits consisted of light brown, brown and gray silty sand and gray sand with silt at depths below 13 feet and were generally moist and medium dense to dense. Logs of the exploratory borings are included in Appendix A. The locations of the borings are shown on Figure 1. 12130 Santa Margarita Court Rancho Cucamonga, CA 91730 IT: 909.989.1751 IF: 909.989.4287 I www.rmacompanies.com - ..J \----z ... • -.. -.. -.. ------... --.. -... .. ,.., -.. ---------.. -.. -.. ~;~~ y'"ifMAGroup Every Proj«t Mattera\www.rmocompanks.com Groundwater Conditions No areas of ponding or standing water were present at the time of our study. Groundwater was not encountered during our subsurface exploration. According to the Geotracker website (http://geotracker.waterboards.ca.gov), groundwater was encountered in a monitoring well located approximately 1 mile northwest of the site was at a depth of 28 feet in 2005. Based upon information on the website, the elevation of the monitoring well is 67 feet above sea level, elevation at the site ranges from 64 to 6 7 feet above sea level. Infiltratlon Test Procedure The infiltrometer equipment consisted of two calibrated plastic cylinders, two alwninum rings, constant level float values, shutoff values, and plastic tubing to connect the cylinders and aluminum rings. Calibrations were marked directly on the plastic cylinders. The cylinders were connected to special supports to prevent tipping and to maintain proper height. The aluminum rings were 12 and 24 inches in diameter and 20 inches high. The float valves were used to maintain a constant water level in the aluminum rings. Infiltration rate of water during the test was determined by monitoring volume changes in the calibrated cylinders. Testing was continued until a relatively uniform infiltration rate was obtained . Infiltration Test Results The testing yielded the following infiltration rates: Table 1 Measured Infiltration Rates Location Infiltration Rate Infiltration Rate (cm/hr) (in/hr) P-1 (Center of nronosed parking lot) 0 0 P-2/South side of orooosed parkiru, lot) 0 0 P-3 /Center of south basin) 2.55 1.00 P-4/North side of south basin) 2.12 0.84 P-5/Center of north basin) 0.85 0.33 P-6/Northeast comer of north basin) 1.27 0.50 Infiltration of water into the paralic soils consisting of dense silty sand at the depths tested ranged from 0.0 to 2.55 cm/hr (0.0 to 1.00 in/hr). Infiltration test result sheets are included in Appendix A. Desiga Considerations Monitoring of actual facility performance has shown that the full-scale infiltration rate is far lower than the rate measured by small-scale testing. The infiltration rate will decline between maintenance cycles as the Best Management Practices (BMP) surface becomes clogged and fine soil particulates accumulate in the basin bottom. Thus an appropriate factor of safety must be applied to the measured infiltration rate and incorporated into facility design. The City of Carlsbad BMP Design Manual specifies a procedure for determining safety factors by using a point system related to the suitability of underlying soils for infiltration and design of infiltration systems. There are four safety factors considerations related to soil conditions (Factor Category A): • Soil assessment methods (e.g., number of borings or test pits) and the measurement method used to determine short-term infiltration rates . • Predominant soil texture and the percent of fines that can influence the potential for clogging. Kaiser Pennanente Ca~sbad Parking Lot Expansion Hanna Gabriel Wells Architects May 10, 2017 RMA Project No.: 17-0497-01 Page2 .. • ----------------------.. -... ----... --.. -- ~;~~ Y'RMAGroup Every Projtcl Mattera! www.rmocompanits.com • Vertical and horizontal soil variability. • Depth to seasonal high groundwater and the presence of relatively impervious layers. Descriptions of each concern are presented in the following table. Factor Category A Suitabilirv Assessment Related Considerations for Infiltration Facilirv Safetv Factors Consideration Hi"h Concern (3) Medium Concern (2) Low Concern (1) Direct measurement of Direct measurement of 2'.: Use of soil survey maps 2 20% of the infiltration 50% of infiltration area with localized Assessment methods or simple texture analysis area with localized measurement methods or to estimate short-term infiltration measurement use of extensive test pit infiltration rates methods (e.g. infiltration measurement infiltrometer) methods Texture Class Silty and clayey soils with Loamy soils Granular to slightly siimificant fines loamv soils Highly variable soils indicated from site Soil borings/test pits Multiple soil borings/test Site soil variability assessment or limited soil indicate moderately pits indicate relatively borings collected during homogeneous soils homogenous soils. site assessment Depth of groundwater or < 5 feet below facility 5-10 feet below facility > 10 feet below facility imnervious laver bottom bottom bottom There are three safety factors considerations related to facility design (Factor Category B): • Level of pretreatment and expected influent sediment loads. • Redundancy of BMP facilities. • Intended or unintended compactions of soils during or after construction. Descriptions of each concern are presented in the following table. Kaiser Permanente Ca~sbad Parking Lot Expansion Hanna Gabriel Wells Architects May 10, 2017 RMA Project No.: 17-0497-01 Page3 .. • -.. .. .. .. ---------.. .. .. --.. .. ---------.. ----- ~:;~#.. Y'iRMAGroup Every Proj«t Mattenlwww.rmocompanies.com Factor Category B Desi= Related Considerations for Infiltration Facilitv Safet Factors Consideration Hie:h Concern (3) Medium Concern (2) Low Concern (1) Pretreatment from gross Good pretreatment with solids removal devices Excellent pretreatment only such as BMP's that mitigate with BMPs that mitigate coarse sediments such as hydrodynamic vegetated swales AND fine sediments such as Level of pretreatment or separators, racks and influent sediment loads bioretention or media screens AND tributary filtration OR expected influent area includes landscaped from the tributary area sedimentation or facility sediment load areas, steep slopes, high are expected to be only treats runoff only traffic areas, or any other relatively low (e.g. low treats runoff from areas expected to traffic, mild slopes, relatively clean surfaces, produce high sediment, disconnected impervious such as rooftops. trash or debris loads. areas, etc.). High redundancy, Medium redundancy, multiple components other BMPs available in capable of operating Redundancy of treatment No redundancy in BMP treatment train to independently and in treatment train. maintain at least 50% of parallel, maintain at least function of facility in 90% of facility event of failure . functionality in event of failure. Heavy equipment Construction of facility actively prohibited from Compaction during on a compacted site or Medium probability of infiltration areas during construction elevated probability of unintended/indirect construction and low unintended/indirect compaction. probability of compaction . unintended/indirect comoaction . The City of Carlsbad BMP Design Manual specifies the following procedure to determine a safety factors for measured infiltration rates: • A level of concern is determined for each consideration in the Factor Category tables above. A corresponding Factor Value (v) is determined for each concern. The Factor Values are 3 for high concerns, 2 for medium concerns, and 1 for low concerns. • Each Factor Value (v) is multiplied by an Assigned Weight (w) to determine a Product Value (p). • The Product Values (p) within each Factor Category (A and B) are summed to obtain a Safety Factor (SA and Ss) for each Factor Category. • The Safety Factors for each Factor Category are multiplied to determine a Combined Safety Factor (S-rm). If the Combined Safety Factor is less than 2, then 2 shall be used as the Safety Factor. • The Measured Infiltration Rate (KM) is divided by the Combined Safety Factor (SrnT) to determine the Design Infiltration Rate (KnESIGN)- Our selected Factor Values (v), Measured Infiltration Rate (KM) and Calculated Safety Factor (SA) are presented in the table below . Kaiser Pennanente Carlsbad Parking Lot Expansion Hanna Gabriel Wells Architects May 10, 2017 RMA Project No.: 17-0497-01 Page4 .. .. -.. -.. ---.. ---------.. -------------.. ---- :,-;<#.. Y'RMAGroup Every ProjtctMatteralwww.rmacompanies.com Factor of Safety and Des;..., Infiltration Rate and Worksheet Assigned Factor Product (p) Factor Category Factor Description Weight (w) Value (v) p=wxv Soil assessment methods 0.25 2 0.5 Predominant soil texture 0.25 2 0.5 A Suitability Site soil variability 0.25 I 0.25 Assessment Depth to groundwater / impervious layer 0.25 I 0.25 Suitabilitv Assessment Safety Factor, SA = L" 1.5 Level of pretreatment/ expected sediment loads 0.25 I 0.25 B Design Redundancy 0.25 3 0.75 Compaction during construction 0.25 3 0.75 Desi= Safetv Factor, Sa -L" 1.75 Combined Safety Factor, Srm·= SA x S8 2.6 Measured Infiltration Rate, inch/hr, KM (corrected for test-specific bias) See Table 2 Design Infiltration Rate, in/hr, KoF.SIGN = KM/S-rcrr See Table 2 We recommend that the lowest measured infiltration rate from each basin and the proposed parking lot be used to determine the design infiltration rate for each area by dividing the measured infiltration rate by the safety factor determined above. The minimum safety factor according to the City of Carlsbad's Design Manual is 2.0. Based upon the above Factor of Safety and Design Infiltration Rate and Worksheet, the calculated Factor of Safety is 2.6. Table 2 below lists the recommended design infiltration rates for the proposed parking lot and both of the proposed biofiltration basins. The design engineer may also specify a higher safety factor at his discretion. T able 2 Recommended Measured and Desian Infiltration Rate Measured Design Location Infiltration Rate Infiltration Rate (in/hr) (in/hr) Proposed na~ lot 0 0 South Basin 0.84 0.32 North Basin 0.33 0.13 It is also recommended that if a basin is proposed the bottom be tipped once design grade is reached to help mitigate unintended compaction of soils that might occur during excavation of the basin. A maintenance plan should also be developed and implemented to restore infiltration properties of soils that may be impacted by sedimentation or other adverse conditions. Infiltration Test Conclusions The City of Carlsbad does not include a minimum infiltration rate in their BMP Design Manual. Some other agencies (the counties of Los Angeles, San Bernardino and Riverside) in southern California apply a minimum corrected infiltration rate of 0.3 in/hr. It is our professional opinion, based upon the infiltration rates obtained in our testing, that the use of permeable pavement in the proposed parking lot is not recommended due to the very low infiltration rate encounter in the tests within the proposed parking lot. Additionally, the proposed biofiltration basins had infiltration rates, when the minimum safety Kaiser Permanente Carlsbad PaI1<ing Lot Expansion Hanna Gabriel Wells Architects May 10, 2017 RMA Project No.: 17-0497-01 Page 5 • " .. "' .. .. .. • .. • .. .. -.. .. -- "" .. .. ----... .. ---.. .. .. -.. -.. -- factor is applied, of 0.32 and 0.13 in/hr and would be considered infeasible in other jurisdictions. Therefore, it is our opinion that based upon the onsite soils very low infiltration rates that the site is not suitable for full stormwater infiltration. Additionally, if permeable pavement is proposed, the City of Carlsbad's BMP Manual indicates that since the infiltration rate is less than 0.5 in/hr an underdrain is required. Additionally, the permeable pavement's design goal is for pollutant control only and not for infiltration . The City of Carlsbad I-8 form is also attached in Appendix B. Based upon the Form 1-8, the site qualifies as a no infiltration site due to the low infiltration rates (infiltration rates below 0.5 in/hr) and existing underground utilities (particularly to electrical and telephone utilities) that service the existing Medical Office Building in the area of the proposed biofiltration basins . Pavement Structural Section Laboratory testing of samples obtained from the site by our representative indicates that subgrade soil bas a Resistance (R) Value of 71. The results of our laboratory tests are attached as Appendix A of this report . Structural sections were designed using the procedures outlined in Chapter 630 of the California Highway Design Manual (Caltrans, 2012). Tbis procedure uses the principle that the pavement structural section must be of adequate thickness to distribute the load from the design traffic index (TI) to the subgrade soils in such a manner that the stresses from the applied loads do not exceed the strength of the soil (R-value). Development of the design traffic indexes on the basis of a traffic study is beyond the scope of this report; however, our experience indicates that traffic indexes of 5 is typical for light auto parking and 7 is typical for fire and delivery truck lanes for the heavier delivery vehicles and drive lanes. We have provided alternate structural sections for each traffic index. Selection of the final pavement structural section should be based on economic considerations which are beyond the scope of this investigation. The recommended structural section is as follows: Light Auto Parking ffi=S.0 R-Value=71): 3.0 inches of asphaltic concrete over 4.0 inches of crushed aggregate base or 4.0 inches of asphalt concrete on 12.0 inches of compacted subgrade soils Fire and deliyezy truck Janes m-1.0 R-Value-71): 4.5 inches of asphalt concrete over 4.5 inches of crushed aggregate base or 5.0 inches of asphalt concrete on 12.0 inches of compacted subgrade soils Portland cement concrete (PCC) pavements for areas which are subject to traffic loads may be designed with a minimum thickness of 6.0 inches of Portland cement concrete on 6.0 inches of crushed aggregate base . The materials and methods used during construction should conform to the latest edition of the Standard Specifications for Public Works Construction (SSPWC). The aggregate base course should conform to the SSPWC Section 200-2.2 for Crushed Aggregate Base. The asphalt surface course should conform to the SSPWC Section 203-6. If the asphalt concrete section is placed in two lifts, the cold joint between lifts should not be designed at the center of the asphaltic-concrete section . Kaiser Permanente Carlsbad Parking Lot Expansion Hanna Gabriel Wells Architects May 10, 2017 RMA Project No.: 17-0497-01 Page6 .. • ------------------.. -------- - • -.. ---- Closure This report is subject to review of the local building official who may request clarification or modifications of the report prior to approval. We appreciate this opportunity to be of continued service to you. If you have any questions regarding this report, please do not hesitate to contact us at your convenience. Respectfully, neth owell, PG, CEG Project Geologist CEG 2470 .. ~r::- President GE2362 Attachments: Kaiser Pennanente Carisbad Parking Lot Expansion Hanna Gabriel Wells Architects May 2, 2017 RMA Project No.: 17-0497-01 Page? -.. ---------------.. .. --- ---- ---.. .. .. .. .. -- ~ 'V RM.A Group Every Proj«t Matteralwww.rmacomponJes.com FIGURE EXISTING TREES TO REMAIN PROTECTED -- IN PLACE, TYP. \~ o !,-r~.,.._-;:-''1.-------..rlUIIT, -~ <13> c • f« 1/ EXISTING\ ,, ,r flii!~--· PARKING . ,,<; , (6)EXISTINGPARKING ~,. ,,.., / m ,,, ',:,,., p~/->"' (7)NEWPARKING ' STAI.LS "'j O STA/..LS.._/'"°' o , , .., / .., .., ~" .., · ~ .., STAI.LS '---"-, (7 ACCE E STAL S !!l! \ _j '--> It¼ ~ ACCESS AISLES 2s ~ ,._,,,__----.,~ ~ \ N ~ ~CURBRAMP ,, --'I-'-""'~ ' m a "' ~ I DELETEmEXJSTING~ARKING I I FtN. ~ ,..,.=.,Mov .. ,~ ol ~~~: m~I . -- -- \§ "'1 a---n,L ) , -.. c---L. ~ ~r::=~ ~ ~~l~ , -~ --Y l ~,. J ~~(~~ ~~~ch tJ~ ~-~~ ) f EXISTING MONUMENT SIGN (11)NEWSHADE TREES ADJACENT TO NEW PARKING STALLS AVENIDA ENCINAS NEW STORM DRAIN POINT CONNECTION PER CML ENGINEER NEW BIORETENTlON BASIN PER CML ENGINEER EXISTING PLANTERS, TYP. [!STING TREES REMAIN PROTEC- IN PLACE, TYP. LEGEND !t -Indicates Approximate Boring Location S:N 0 10' 2<1 M-i 40' !;, ~ ~ ,/'fAMAlOAJUl"ACOl!U ~-.. --------~-....----! ~ CUCA.\IOf«iA.CA917lO IIT'EMI -1 ·· 10.-.n:I ,_~4:~0~1•~=:::M PLAN CHANGES Boring and Infiltration Tesr Location Map !t -Jadicates Approximate Infiltration Test Location P-:'11 BASE MAI' PROVIDED BY: Hanna Gabriel waua Nthl".ects THIS PLA.'l HAS BF.EN PRE.PAR.FD FOR USE AS A GE011;0{N1CAL AND GEOL(XjfCAL MAP _,,....,.,,.,.....,,.,,...,,...,.,,..,.,..n,._, Hanna Gabriel Wells Architects 1955 Bacon Street San Diego, Ca 92107 NORTH Ki.iser Pcrmanentt UrlsMd Parking Lot Expansion 6860 A,.·cnida Encinas Carlsbad, CA iR.\lA.IOBNO~ 11-0'!1'1-0I ilo' I OF I 1 .. ---.. ---------------.. -.. .. .. • .. • .. .. .. .. .. .. .. .. ... ::,:; ... ~ YilMAGroup Every ProjectMattenlwww.rmacompanies.com APPENDIXA FIELD INVESTIGATION AND INFILTRATION TEST RESULTS .., ... .., ------------------.. .. ... .. ... .. .. .. .. .. ... .. .. .. .. • ... :,";~#., YRMAGroup Every Proje<I Matten!www.rmacompanks.com APPENDIXA FIELD INVESTIGATION A-1.00 FIELD EXPWRATION A-1.01 Number of Borings Our subsurface investigation consisted of 4 exploratory borings drilled with a Mini Mole solid flight auger drill rig. A-1.02 Location of Borings A Boring and Infiltration Test Location Map showing the approximate locations of the borings is presented as Figure 1. A-1.03 Boring Logging Logs of borings were prepared by one of our staff and are attached in this appendix. The logs contain factual information and interpretation of subsurface conditions between samples. The strata indicated on these logs represent the approximate boundary between earth units and the transition may be gradual. The logs show subsurface conditions at the dates and locations indicated, and may not be representative of subsurface conditions at other locations and times. Identification of the soils encountered during the subsurface exploration was made using the field identification procedure of the Unified Soils Classification System (ASTM D2488). A legend indicating the symbols and definitions used in this classification system and a legend defining the terms used in describing the relative compaction, consistency or firmness of the soil are attached in this appendix. Bag samples of the major earth units were obtained for laboratory inspection and testing, and the in-place density of the various strata encountered in the exploration was determined A-1.04 Soil Infiltration Testing Six soil infiltration tests were performed using the dual ring infiltrometer test procedure (ASTM Test Method D 3385) described in the City of Carlsbad BMP Design Manual (2016). Results of the testing are attached to this appendix. Locations of the tests are shown on Figure 1 . Kaiser Permanente Carlsbad Parking Lot Expansion Hanna Gabriel Wells Architects May 10, 2017 RMA Project No.: 17-0497-01 PageA1 .. .. .. .. .. .. .. .. .. --.. --.. .. .. .. .. .. .. .. .. • .. .. -... .. ... .. .. .. .. • .. .. _,-;,~ ...iRMAGroup Every Proj«tMatteralwww.rmacompanies.com -" w g 0 • ~ ~ 0 0 I 0 ~ 8 - ~ • : ' " MAJOR DIVISIONS COARSE GRAINED SOILS (-tw,5()%ol .-.illl.AAGER tt-.,l,b.:100- liz•) GRAVELS (MnthlnOO'lllol --· LARGERhnh No.4-..... SANDS CLEAN GRAVELS (lillloormr...) GRAVELS WITHFINES -~---, CLEAN SANDS GROUP SYMBOLS . . . -. GW 0 < GP /ol /1 . . . . . . . . GM GC SP • • • SM TYPICAL NAMES Well i,tldedgrwal, gr......-.l mx1 ....... trttleorno~nes. (/) >- ::. ...J w N (/) w ...J u •. jMn11wl50'llool --· SMAI.LER!hanlhe r,1o.,_.,.) SANDS ~•+.•~•~-+-------------< WITH FINES ;;,' ,/4 ,l >- et: <( 0.. 0 ~ I - ~ ra , >-- ~ ~ " 0 >a • N . FINE GRAINED SOILS (ll<itahn50%ol --~ t.nNo.:100-_, ~-l (~/.; SC ML SILTS AND CLAYS CL (Llql.id lltrit LESS ltGn 50) OL MH SIL TS AND CLAYS (Llql.idmlGREAlERthan50) ~ CH -, , , , , , OH , , , HIGHLY ORGANIC SOILS Pt tnorganlcsib inlVf:f'ffino-. rockft<U eil:yordl!l/fl'lftne.-.:ltorfR/<1i,ib 'Mltl811gl!pla!illdty 1rio.,;ir;ncc:1aysa11owtomed,-,, pla&tidly, ~ ~. &a"laf clayll, .. ~ lean ,.,. lnorgaricsib, rricacecus ordlatamaoaous ftnesa-.ct,or!lilly""'ls,elar;licS1ks Orga,icdayacfmedhmtol-jg,J:(aslldty. orga,icsills. BOUNDARY CLASSIFICATIONS: soils po$$8SSing charadllliltica of tv,o !JOUP' ani designated by corminations of goup IS)"IT'bok. UNIFIED SOIL CLASSIFICATION SYSTEM Kaiser Permanente Ca~sbad Parking Lot Expansion Hanna Gabriel Wells Architects May 10, 2017 RMA Project No.: 17-0497-01 PageA2 -.. ----------------------.. .. -.. ---------- ::r-;~~ Y'RMAGroup Every ProjtctMatteralwww.rmocomponfes.com I. SOIL STRENGTH/DENSITY BASED ON STANDARD PENETRATION TESTS Compactness of sand Consistency of clay Penet.ration Resistance N Compactness Penetration Resistance N Consistency (blows/Ft) (blows/ft) 0-4 Very Loose <2 Very Soft 4-10 Loose 2-4 Soft 10-30 Medium Dense 4-8 Medium Stiff 30-50 Dense 8-15 Stiff >50 Very Dense 15-30 Very Stiff >30 Hard N = Number of blows of 140 lb. weight falling 30 in. to drive 2-in OD sampler 1 ft. BASED ON RELATIVE COMPACTION Compactness of sand % Compaction <75 75-83 83-90 >90 II. SOIL MOISTURE Compactness Loose Medium Dense Dense Very Dense Moisture of sands % Moisture <5% 5-12% >12% Description Dry Moist Very Moist Consistency of clay % Compaction <80 80-85 85-90 >90 Moisture of clays % Moisture <12% 12-20% >20% Consistency Soft Medium Stiff Stiff Very Stiff Description Dry Moist Very Moist, wet Soil Description Legend Kaiser Permanente Carlsbad Parking Lot Expansion Hanna Gabriel Wells Architects May 10, 2017 RMA Project No.: 17-0497-01 Page A3 ------------------.. --------... -------.. -·- Date Drilled: Logged By: 4-20-2017 KRD Exploratory Boring Log Drilling Equipment: Boring I Iole Diameter: Boring No. B-1 Mini Mole 6" Location: See Boring and Infiltration Test Location Map Drive Weights: 140 lbs. 30" Samples .c if ~1= a.e t~ ~-! ~ Q) -U) -~ Q) -"9 E sS-" E » ::;u "'""" ID m U) ma U) - - -0 23 - 5-0 27 - - -0 25 - 10-0 34 - - -0 32 - 15-0 29 - - - - 20- - - - - 25- - - - - Sample Types: {!] -Ring Sample {!] -Tube Sample ~ ~ 'ii' U) ~:s u a. E o-5 U) ~ >, 2:-::, <9 en " SM : .. ' i .. ,·. .. ' .. ' Drop: Material Description This log contains factual infonnation and interpretation of the subsur1ace conditions between the samples. The stratum indicated on this log represent the approximate boundary between earth units and the transition may be gradual. The log show subsurface conditions at the date and location indicated, and may not be representative of subsurface conditions at other locations and limes. Paralic deposits (Qop): Light yellowish-brown silty fine to medium sand, moist, medium dense to dense, thin silty clay lens (about 1" thick) at 1 foot. At 2 feet becomes reddish-brown in color At 7 feet becomes gray in color At 10 feet becomes reddish-brown in color Gray brown fine sand with silt, moist, medium dense to dense r.J -Bulk Sample ~-No Recovery @) -SPT Sample ~ -End of Boring Kaiser Permanente Carlsbad Parking Lot Expansion Hanna Gabriel Wells Architects RMA Project No.: 17-0497-01 PageA-4 .. • .. --------.. ----------- , .. ------------.. .. ·~ ::,-; ... ~ YRMAGroup Every Project Mattera I www,rmocompanies.com Exploratory Boring Log Boring No. B-2 Date Drilled: Logged By: 4-20-2017 KRD Location: See Boring and Infiltration Test Location Map Samples ~ <I) -~:g :g_~ l! f -c "' ! 8. ~t ~~* ai 'U &l o. E <I) -•,e; ~ >-• i~ "SE oo-:::, .2 0 a, ~ ::;o 2, (!)"' co e "' • - I - -0 21 - 5-0 32 SM .. : : : - -·. -0 28 •. : --.. IQ- 0 27 - -,·, -0 35 '·' •. ' - SM-SP 15-0 37 - - - - 20- - - - - 25- - - - - Sample Types: : Drilling Equipment: Boring Hole Diameter: Drive Weights: Drop: Mini Mole 6" 140 lbs. 30" Material Description This log contains factual infonnation and interpretation of the subsur1ace conditions between the samples. The stratum indicated on this log represent the approximate boundary between earth units and the transition may be gradual. The log show subsurface conditions at the date and location indicated, and may not be representative of subsurface conditions at other locations and times . Pamlic deposits (Qop): Light yellowish-brown silty fine to medium sand, moist, medium dense to dense, thin silty clay lens (about 1" thick) at 1 foot. At 2 feet becomes reddish-brown in color At 7 feet becomes gray in color At 10 feet becomes reddish-brown in color Gray brown fine sand with silt, moist, medium dense to dense [!] -Ring Sample E'] -Bulk Sample ~-No Recovery I!] -Tube Sample ~ -SPT Sample ~ -End of Boring Kaiser Permanente Carlsbad Parking Lot Expansion Hanna Gabriel Wells Architects RMA Project No.: 17-0497-01 PageA-5 .. .. -----------.. -------.. -------.. .. .. .. .. .. - ::r;:~ Y' RMA Group Every Project Matters I www.rmacompanies.com Exploratory Boring Log Boring No. B-3 Date Drilled: Logged By: 4-20-2017 KRD Location: See Boring and Infiltration Test Location Map Samples ~ l!g 15.-! 8. " .:!: 0. "s Cl !~ .2! ~ E a, .. co 8-rn - - -0 - 5-0 19 29 I - - -0 38 - 10-0 -41 - -0 36 - 15-0 47 - - - - 20- - - - - 25- - - - - Sample Types: ~ ~c 0 rn ~ " -cc-(J ~§~ " 0 Cl8 rn :::, ~(.) ~ Cl SM SM-SP ~ :8 o. E ~ >-Cl rn ·. : ·. : : '· '· -.. : ' : Drilling Equipment: Boring Hole Diameter: Drive Weights: Drop: Mini Mole 6" 140 lbs. 30" Material Description This log contains factual information and interpretation of the subsurface conditions between the samples. The stratum Indicated on this log represent the approximate boundary between earth units and the transition may be gradual. The log show subsurface condi~ons at the date and location indicated, and may not be representative of subsurface conditions at other locations and times. Paralic deposits (Qop): Light yellowish-brown silty fine to medium sand, moist, medium dense to dense. At 2 feet becomes reddish-brown in color ---- Gray brown fine sand with silt, moist, medium dense to dense [!] -Ring Sample [J -Bulk Sample ~-No Recovery I!] -Tube Sample ~ -SPT Sample .............. -End of Boring Kaiser Permanente Ca~sbad Par1<ing Lot Expansion Hanna Gabriel Wells Architects RMA Project No.: 17-0497-01 PageA-6 .. -.. -.. .. ----... --.. ... -----... --... -------------- :r;:~ Y'ilMAGroup Every Project Matterslwww.rmocomponies.com Date Drilled: Logged By: 4-20-2017 KRD Exploratory Boring Log Drilling Equipment; Boring Hole Diameter: Boring No. B-4 Mini Mole 6" J..ocation: See Boring and Infiltration Test Location Map Drive Weights: 140 lbs. 30" Samples ie if ~ 1: " ~t :, " -0. 8-u,-* " -0 5-Cl E >-"SE ffl f-a:ie, "' ffl ~(.) rn rn -I - -0 23 - 5-0 26 - - -0 31 - 10-0 -44 - -0 39 - 15-0 42 - - - - 20- - - - - 25- - - - - Sample Types: ~ -Ring Sample [!] -Tube Sample ,;, 0 cc- " 0 Cl-!, 2:-Cl rn .!::!Q (.) .c .c "-E rn ~>, :, " rn SM ·. : : ~ : Drop: Material Description This log contains factual infonnation and inte,pratation of the subsurface conditions between the samples. The stratum indicated on this log represent the approximate boundary between earth units and the transition may be gradual. The log show subsurface conditions at the date and locatioo indicated, and may not be representative of subsurface conditions at other locations and times. Paralic deposits (Qop): Light yellowish-brown silty fine to medium sand, moist, medium dense to dense. At 2 feet becomes reddish-brown in color -~r~~--~--------------sM-sP ](~ Grnybcown fines,nd with silt, moist, medium dense to dense r.J -Bulk Sample ~-No Recovery ~ -SIYf Sample ............... -End of Boring Kaiser Pennanente Carlsbad Parking Lot Expansion Hanna Gabriel Wells Architects RMA Project No.: 17-0497-01 PageA-7 .. • .. .. ------.. -----------.. -------.. -.. .. ... --.. - ~ 'VRMA.Group Every Proj«I Mattera\www.rmocompanits.com INFILTRATION TEST RESULTS Project ID 17-0497-01 Constants Test Location P-1 Center of proposed parking lot Inner Ring Tested By 520DKR Anlr. Space Date 4/20/17 Flow Readings s Date Tune Elpd Inner Ring o, Y, h, Tune Rg Flow No. E 2014 (min) (min) (cm3) (cnl) s 4/20 9:00:00 0 50 1 125 E 4120 9:02:00 2 175 s 4/20 9:02:00 5 175 2 25 E 4/20 9:09:00 7 200 s 4/20 9:09:00 5 200 3 50 E 4/20 9:14:00 12 250 s 4/20 9:14:00 5 250 4 0 E 4/20 9:19:00 17 250 s 4/20 9:19:00 5 250 5 0 E 4/20 9:24:00 22 250 s 4/20 9:24:00 10 250 6 0 E 4/20 9:34:00 32 250 s 4/20 9:34:00 10 250 7 0 E 4/20 9:44:00 42 250 s 4/20 9:44:00 10 250 • 0 E 4/20 9:54:00 52 250 s 4/20 9:54:00 10 250 9 0 E 4/20 10:04:00 62 250 Kaiser Permanente Ca~sbad Parking Lot Expansion Hanna Gabriel Wells Architects AnlrSpace R;ng Flow (cm3) (cm3) 1,600 3,700 2,100 3,700 1,000 4,700 4,700 400 5,100 5,100 300 5,400 5,400 300 5,700 5,700 200 5,900 5,900 200 6,100 6,100 200 6,300 6,300 200 6,500 Area Depth ofLiq (cm2) (cm) 707 7.6 2106 7.6 Iner Infil Rate ln, Ank (cm'hr) (cm'hr) 5.30 29.91 0.42 5.70 0.85 2.28 0.00 1.71 0.00 1.71 0.00 0.57 0.00 0.57 0.00 0.57 0.00 0.57 Iner Infil Rate lm Ank (in/hr) (in/hr) Remuks 2.09 0.17 0.33 0.00 0.00 0.00 0.00 0.00 0.00 11.78 2.24 0.90 0.67 0.67 0.22 0.22 0.22 0.22 May 10, 2017 RMA Project No,: 17-0497-01 Page AS .. • .. .. .. .. ------------... ----------------.. -.. :::r-;,~ YilMAGroup Every ProjectMatteralwww.rmocompanies.com INFILTRATION TEST RESULTS Project ID 17-0497-01 Constants Test Location P-2 South side ofproposed parking lot Inner Ring Tested By 520DKR Anlr. Space Date 4/20/17 Flow Readings s Date Tune Elpd Inner Ring o, Y, h, Tune Rg Flow No. E 2014 (min) (min) (cm3) (cnl) s 4/20 10:15:00 0 0 I 25 E 4/20 10:25:00 10 25 s 4/20 10:25:00 10 25 2 25 E 4/20 10:35:00 20 50 s 4/20 10:35:00 10 50 3 10 E 4/20 10:45:00 30 60 s 4/20 10:45:00 10 60 4 0 E 4/20 10:55:00 40 60 s 4/20 10:55:00 10 60 5 0 E 4/20 11:05:00 50 60 s 4/20 11:05:00 10 60 6 0 E 4/20 IUS:00 60 60 Kaiser Pennanente Carlsbad Parking Lot Expansion Hanna Gabriel Wells Architects Anlr Space rung Flow (cni:1) (cnl) 0 250 250 250 100 350 350 100 450 450 100 550 550 50 600 600 50 650 Area Depth ofLiq (cm2) (cm) 707 7.6 2106 7.6 Iner Infil Rate '"' An~ (cm'hr) (cm'hr) 0.21 0.71 0.21 0.28 0.08 0.28 0.00 0.28 0.00 0.14 0.00 0.14 lnerlnfil Rate '"' (in/hr) 0.08 0.08 O.D3 0.00 0.00 0.00 Anlr (in/hr) RenmrlG 0,28 0.11 0.11 0.11 0.06 0.06 May 10, 2017 RMA Project No.: 17-0497-01 Page A9 -.. -.. ---------------------... -... -.. --- • ... ... -- :,-; ... ~ YRMAGroup Every Proj«t Matteralwww.rmacomponles.com INFILTRATION TEST RESULTS Project ID 17-0497-01 Constants Test Location P-3 Center of south basin Inner Ring Tested By 520DKR Anlr. Space Date 4/20/17 Flow Readings s Date Ton, Elpd Inner Ring AnlrSpace o, Ye he Ton, Rg No. E 2014 (min) (min) (cm3) s 4/20 11:30:00 0 100 I E 4/20 11:40:00 10 750 s 4/20 11,40,00 10 750 2 E 4/20 11:50:00 20 1,175 s 4/20 11:50:00 10 1,175 3 E 4/20 12:00:00 30 1,550 s 4/20 12:00:00 10 1,550 4 E 4/20 12:10:00 40 1,850 s 4/20 12:10:00 10 1,850 5 E 4/20 12:20:00 50 2,150 s 4/20 12:20:00 10 2,150 6 E 4/20 12:30:00 60 2,450 Kaiser Permanente Carlsbad Parking Lot Expansion Hanna Gabriel Wells Architects Flow Ring Flow (cm3) (cnl) (cm3) 300 650 2,700 3,000 3,000 425 5,900 2,900 5,900 375 2,200 8,100 8,100 300 2,100 10,200 10,200 300 1,800 12,000 12,000 300 1,800 13,800 Area Depth ofLiq (cm2) (cm) 707 7.6 2106 7.6 Iner Jnfil Rate Im Anlr (cm'hr) (cm'hr) 5.52 7.69 3.61 8.26 3.18 6.27 2.55 5.98 2.55 5.13 2.55 5.13 Iner Infil Rate Im Ank (in/hr) (in/hr) Remuks 2.17 1.42 1.25 1.00 1.00 1.00 3.03 3.25 2.47 2.36 2.02 2.02 May 10, 2017 RMA Project No.: 17-0497-01 Page A10 .. .. -.. -.. -----------.. ---------.. -----.. .. .. -- Project ID 17-0497-01 Constants Test Location P-4 North side of south basin Inner Ring Tested By 520DKR Anlr. Space Date 4/20/17 Flow Readings s Date Time Elpd Inner Ring AnlrSpace o, Y, he Time Rg No. E 2014 (min) (min) (cm3) s 4/20 12:45:00 0 0 1 E 4/20 12:55:00 10 800 s 4/20 12:55:00 10 800 2 E 4/20 13:05:00 20 1,250 s 4/20 13:05:00 10 1,250 3 E 4/20 13:15:00 30 1,600 s 4/20 4 13:15:00 10 1,600 E 4/20 13:25:00 40 1,900 s 4/20 13:25:00 10 1,900 5 E 4/20 13:35:00 50 2,150 s 4/20 13:35:00 10 2,150 6 E 4/20 13:45:00 60 2,400 Kaiser Permanente Ca~sbad Parking Lot Expansion Hanna Gabriel Wells Architects Flow Rmg Flow (cm3) (cm3) (cni:1) 100 800 2,800 2,700 2,800 450 1,900 4,700 4,700 350 2,000 6,700 6,700 300 1,800 8,500 8,500 250 1,600 10,100 250 10,100 1,600 11,700 Area Depth ofLiq (cm2) (cm) 707 7.6 2106 7.6 Inerlnfil Rate In, Anh- (cm'hr) (cm'hr) 6.79 7.69 3.82 5.41 2.97 5.70 2.55 5.13 2.12 4.56 2.12 4.56 Inerlnfil Rate In, Anh- (in/hr) (in/hr) Remarl<s 2.67 3.03 1.50 2.13 1.17 2.24 1.00 2.02 0.84 1.79 0.84 1.79 May 10, 2017 RMA Project No.: 17-0497-01 Page A11 .. .. -.. ---,. -------.. --.. .. .. .. .. • -------.. ------ ::,::: ... ~ YRMAGroup Every ProjectMatte,.lwww.rmocompan~s.com Project ID 17-0497-01 Constants Test Location P-4 Center of north basin Inner Ring Tested By 520DKR Anlr. Space Date 4/20/17 Flow Readings s Date Tim: Elpd Inner Ring Anlr Space o, Y, h, Tim: Rg No. E 2014 (mm) (mm) (cm3) s 4/20 14:00:00 0 0 1 E 4/20 14:10:00 10 250 s 4/20 14:10:00 10 250 2 E 4/20 14:20:00 20 450 s 4/20 14:20:00 10 450 3 E 4/20 14:30:00 30 650 s 4/20 14:30:00 10 650 4 E 4/20 14:40:00 40 800 s 4/20 14:40:00 10 800 5 E 4/20 14:50:00 50 900 s 4/20 14:50:00 10 900 6 E 4/20 15:00:00 60 1,000 Kaiser Pem,anente Carlsbad Parl<ing Lot Expansion Hanna Gabriel Wells Architects Flow Rmg Flow (cm') (cm3) (cm3) 200 250 3,100 3,300 3,300 200 1,700 5,000 5,000 200 1,700 6,700 6,700 150 1,700 8,400 8,400 100 1,500 9,900 9,900 100 1,400 11,300 Area Depth ofLiq (cm2) (cm) 707 7.6 2106 7.6 Iner Infil Rate In, Anrr (cm'hr) (cm'hr) 2.12 8.83 l.70 4.84 1.70 4.84 1.27 4.84 0,85 4.27 0.85 3.99 Inerlnfil Rate In, Anrr (in/hr) (in/hr) Remarks 0.84 3.48 0,67 l.91 0.67 1.91 0.50 1.91 0.33 1.68 0.33 1.57 May 10, 2017 RMA Project No.: 17-0497-01 Page A12 .. • .. -------------.. -.. -------------.. ----.. ::r-;~~ y'ifMAGroup Every Project Matteralwww.rmacompanies.com Project ID 17-0497-01 Test location P-6 Northeast comer of north basin Tested By 520DKR Date 4/20/17 ------- Constants Inner Ring Anlr. Space Flow Readings s Date Tm Elpd Inner Ring o, Y, h, Tm Rg No. E 2014 (mm) (mm) (cm3) s 4/20 15:12:00 0 0 l E 4/20 15:22:00 10 200 s 4/20 15:22:00 10 200 2 E 4120 15:32:00 20 400 s 4120 15:32:00 10 400 3 E 4120 15:42:00 30 550 s 4/20 15:42:00 10 550 4 E 4/20 15:52:00 40 700 s 4/20 15:52:00 10 700 5 E 4/20 16:02:00 50 850 s 4120 16:02:00 10 850 6 E 4/20 16:12:00 60 1,000 Kaiser Permanente Carlsbad Parking Lot Expansion Hanna Gabriel Wells Architects Flow (cm3) 200 200 150 150 150 150 Anlr Space Ring Flow (cm3) (cnl) 100 2,900 3,000 3,000 2,000 5,000 5,000 1,400 6,400 6,400 1,400 7,800 7,800 1,300 9,100 9,100 1,300 10,400 Area Depth ofLiq (cm2) (cm) 707 7.6 2106 7.6 Iner Infil Rate In, Anrr (cm'hr) {cm'hr) 1.70 8.26 1.70 5.70 1.27 3.99 1.27 3.99 1.27 3.70 1.27 3.70 Iner Infil Rate In, Anrr (in/hr) (in/hr) Remarks 0.67 3.25 0.67 2.24 0.50 1.57 0.50 1.57 0.50 1.46 0.50 1.46 May 10, 2017 RMA Project No.: 17-0497-01 Page A13 .. .. -------.. -----------------------.. ---- :=r;~~ YilMAGroup Every Proj«tMattefl/www.nnacompanies.com APPENDIXB LABORATORY TESTS .. .. .. .. -----------... .. "' - --... -- .. ----.. .. "' ... , ... -• :,-;~~ Y'ifMAGroup Every Project Mattera! www.rmocomponie.s.com B-1.00 LABORATORY TESTS B-1.01 Resistance Value (R-Value) Resistance Value tests were performed on representative samples of the major soil types encountered by the test methods outlined in California 301. B-1.02 Test Results Test results for all laboratory tests performed on the subject project are presented in this appendix. Kaiser Permanente Cartsbad Parking Lot Expansion Hanna Gabriel Wells Architects May 10, 2017 RMA Project No.: 17-0497-01 Page B1 ::,-;:~ Y RMAGroup Every Project Mattera I www.rmocompanies.com CTM 301 -Detennination of Resistance "R" Value of Treated and Untreated Bases, Subbases --~ .... Q) 1ii E g ..c ro u5 >, ..c "' "' Q) C: .-"<'. (.) ~ .... Q) > 0 (..) and Basement Soils by Stabilometer Sample No. B-2@ 1-4 feet Specimen No A Moisture Content(%) 11.0 Dry Density (pcf) 123.0 Exudation Pressure (psi) 736 Stabilometer R Value 79 Expansion Pressure Dial 0 Use: Traffic Index= 5.0 Gravel Factor= 1.00 Thickness by Expansion (ft) Thickness by Stabilometer (ft) 0.34 &j uilibrium Thick (ft) &juilibrium Pressure R Value Exudation Pressure R Value @300 psi ,, B 11.9 123.0 253 72 0 0.45 n/a 71 C 11.5 123.0 376 7 1 0 0.46 Use Exudation R Value Expansion Pressures Exudation Pressures 2.00 1.80 1.60 1.40 1.20 1.00 0.80 0.60 0.40 0.20 0.00 L/ ~ ~ ... ./ _..,... ./ ~ ..., ./ 100 Q) 90 :::, 80 ni > 70 -- a::: 60 Q) 50 1ii 40 E g 30 ..c 20 ro u5 10 0 0.00 0.50 1.00 1.50 2.00 0 100 200 300 400 500 600 700 800 Cover Thickness by Expansion Pressure (ft) Exudation Pressure (psi) Expansion Pressure R-Value is based on the following structural section: Thickness of AC (ft)= " 0.50 Gi(ac) = 2.50 W(ac) = " Thickness of Aggregate Base (ft)= " 0.50 Gr(base) = 1.1 0 W(base) =" G,{avg) = 1.80 W(avg) = " 145 130 138 Kaiser Permanente Carlsbad Parking Lot Expansion Hanna Gabriel Wells Architects May 10, 2017 RMA Project No.: 17-0497-01 Page 82 :r;:~ Y'RMAGroup Every Project Mattera I www.rmocompanies.com APPENDIXC CITY OF CARLSBAD 1-8 FORM Categorization of Infiltration Feasibility Condition Form 1-8 Part 1 -Full Infiltration Feasibility Screening Criteria Would infiltration of the full design volume be feasible from a physical perspective without any undesirable consequences that cannot be reasonably mitigated? Criteria 1 Screening Question Is the estimated reliable infiltration rate below proposed facility locations greater than 0.5 inches per hour? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2 and .Appendix D. Provide basis: Yes No X Measured infiltration rates ranged from 0.0 in/hr to 0.84 in/hr. With application of the minimum factor of safety th< design infiltration rates would be 0.0 in/hr to 0.32in/hr. This form is included with site infiltration report prepared b, RMAGroup. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability. 2 Can infiltration greater than 0.5 inches per hour be allowed without increasing risk of geotechnical hazards (slope stability, groundwater mounding, utilities, or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2. Provide basis: X !Not applicable. Measured infiltration rates ranged from 0.0 in/hr to 0.84 in/hr. With application of the minimum factoi bf safety the design infiltration rates would be 0.0 in/hr to 0.32in/hr. Infiltration at the site will not impact slope stability since there are no nearby slopes at the site, the soils onsite are !medium dense to dense silty sand and sand with silt and are not subject to hydrocollapse or consolidation based upon ISPT blow counts, are non-expansive and not subject to liquefaction. Groundwater mounding would not be expected !based on the separation between the bottom of the proposed basins being greater than 10 feet and the slow infiltration trates obtained in our testing. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability. hirm 1-8 Page 2 of 4 Criteria Screening Question 3 Can infiltration greater than 0.5 inches per hour be allowed without increasing risk of groundwater contamination (shallow water table, storm water pollutants or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. Provide basis: Yes N o X !Not applicable. Measured infiltration rates ranged from 0.0 in/hr to 0.84 in/hr. With application of the minimum facto1 lof safety the design infiltration rates would be 0.0 in/hr to 0.32in/hr. !Ground water beneath the site was not encountered in or exploratory borings that extended to a depth of 16.5 feel !below the existing ground surface. !According to the Geotracker website (http://geotracker.waterboards.ca.gov), groundwater was encountered in 2 imonitoring well located approximately 1 mile northwest of the site was at a depth of 28 feet in 2005. !Due to the slow infiltration rate and the separation between the groundwater level and the proposed basin bottom 1Plevation and the proposed use as vehicle parking, an increased risk of groundwater contamination is considered veri ow. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability. 4 Can infiltration greater than 0.5 inches per hour be allowed without causing potential water balance issues such as change of seasonality of ephemeral streams or increased discharge of contaminated groundwater to surface waters? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. Provide basis: X !Not applicable. Measured inftltration rates ranged from 0.0 in/hr to 0.84 in/hr. With application of the minimum facto, lof safety the design infiltration rates would be 0.0 in/hr to 0.32in/hr. !Due to the slow infiltration rate and the separation between the groundwater level and the proposed basin bottorr elevation and the proposed use as vehicle parking, and increase potential water balance issues such as change oJ seasonality of ephemeral streams or increased discharge of contaminated groundwater to surface waters is considered very low. No ephemeral streams are located onsite or nearby and the Geotracker website does not indicate a source oJ known contamination within a mile of the site. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability. Part 1 Result" If all answers to rows 1 -4 are "Yes" a full infiltration design is potentially feasible. The feasibility screening category is Full Infiltration If any answer from row 1-4 is "No", infiltration may be possible to some extent but would not generally be feasible or desirable to achieve a "full infiltration" design. Proceed to Part 2 See Part ~ *To be completed usmg gathered site information and best professional judgment considering the definition ofMEP 1n the MS4 Permit. Additional testing and/ or studies may be required by City Engineer to substantiate findings. Form I-8 Page 3 of 4 Part 2 -Partial Infiltration vs. No Infilttation Feasibility Screening Criteria Would infiltration of water in any appreciable amount be physically feasible without any negative consequences that cannot be reasonably mitigated? Criteria Screening Question 5 Do soil and geologic conditions allow for infiltration in any appreciable rate or volume? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2 and Appendix D. Provide basis: Yes No X Measured infiltration rates ranged from 0.0 in/hr to 0.84 in/hr. With application of the minimum factor of safety the design infiltration rates would be 0.0 in/hr to 0.32in/hr. This form is included with site infiltration report prepared by RMAGroup. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates. 6 Can Infiltration in any appreciable quantity be allowed without increasing risk of geotechnical hazards (slope stability, groundwater mounding, utilities, or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in .Appendix C.2. Provide basis: X Infiltration at the site will not impact slope stability since there are no nearby slopes at the site, the soils onsite ar, medium dense to dense silty sand and sand with silt and are not subject to hydrocollapse or consolidation based upon ~PT blow counts, are non-expansive and not subject to liquefaction. Groundwater mounding would not be expecte<I ~ased on the separation between the bottom of the proposed basins being greater than 10 feet and the slow infiltration ~ates obtained in our testing. Would increase risk to existing underground utilities (particularly to electrical an<I elephone utilities) servicing the existing Medical Office Building. ~ummarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative kliscussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates. Form 1-8 Page 4 of 4 Criteria Screening Question 7 Can Infiltration in any appreciable quantity be allowed without posing significant risk for groundwater related concerns (shallow water table, storm water pollutants or other factors)? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. Provide basis: Yes No X Infiltration at the site will not impact slope stability since there are no nearby slopes at the site, the soils onsite are densf silty sand and sand with silt and are not subject to hydrocollapse or consolidation based upon SPT blow counts, arf ~on-expansive and not subject to liquefaction. Groundwater mounding would not be expected based on the separatior. between the bottom of the proposed basins being greater than 10 feet and the slow infiltration rates obtained in ou1 testing. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates. 8 Can infiltration be allowed without violating downstream water rights? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. Provide basis: X The site is not up gradient from a stream course and is located about ½ mile from the ocean. Also, no known watei wells are located within a ½ from the site. Evaluation of downstream water rights is outside of the purview of geotechnical engineering. Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/ data source applicability and why it was not feasible to mitigate low infiltration rates. Part2 Result* If all answers from row 1-4 are yes then partial infiltration design is potentially feasible. The feasibility screening category is Partial Infiltration. If any answer from row 5-8 is no, then infiltration of any volume is considered to be infeasible within the drainage area. The feasibility screening category is No Infiltration. Infiltration *To be completed using gathered site information and best professional judgment considering the definition of MEP in the MS4 Permit. Additional testing and/or studies may be required by City Engineer to substantiate findings. :r;:~ y7RMAGroup Every Pro}tel Mattera I www.rmacompanies.com APPENDIX D REFERENCES :r-;:~ Y iRMAGroup Every Proj~ct Mattera/ www.rmacompanies.com APPENDIXD REFERENCES 1. City of Carlsbad BMP Design Manual, date February, 2016. 2. City of Carlsbad Technical Guidelines for Geotechnical Reports, date January, 1993. 3. Kennedy, M.P., Tan, S.S., Bovard, KR., Alvarez, RM., Watson, M.J., and Gutierrez, C.I., 2007, Geologic map of the Oceanside 30x60-minute quadrangle, California: California Geological Survey, Regional Geologic Map No. 2, scale 1:100,000. Kaiser Permanente Carlsbad Parking Lot Expansion Hanna Gabriel Wells Architects May 10, 2017 RMA Project No.: 17-0497-01 Page D1