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Home My WebLink AboutCT 03-01-01; LA COSTA RESORT & SPA MSTR PLAN; GEOTECHNICAL INVESTIGATION; 2005-03-31I I GEOTECHNICAL INVESTIGATION PROPOSED RESORT VILLAS LA COSTA RESORT & SPA COSTA DEL MAR ROAD CARLSBAD, CALIFORNIA -Prepared By- Sladden Engineering 39-725 Garand Lane, Suite G Palm Desert, Califomia 92211 (760) 772-3893 \ .^laddpn F.nfrinnnrinP Sladden Engineering 6782 Stanton Ave., Suite A, Buena Park, CA 90621 (714) 523-0952 Fax (714) 523-1369 39-725 Garand Ln., Suite G, Palm Desert, CA 92211 (760) 772-3893 Fax (760) 772-3895 November 11, 2003 Project No. 444-3161 03-10-183 La Costa Resort and Spa KSL Development Corporation 2100 Costa Del Mar Road Carlsbad, Califorma, 92009 Attention: Mr. Chevis Hosea Project: Proposed Resort Villas La Costa Resort & Spa 2100 Costa Del Mar Road Carlsbad, California Subject: Geotechnical Investigation Presented herewith is the report of our Geotechnical Investigation prepared for the new resort villas proposed for the La Costa Resort & Spa complex located at 2100 Costa Del Mar Road in the City of Carlsbad, California. The preliminary plans indicate that the proposed resort viUas will consist of 2 or 3 story structures with subterranean parking levels. This report was prepared in order to provide recommendations for design and construction ofthe proposed building foundations. This report presents the results of our field investigation and laboratory testing along with conclusions and recommendations for design and construction. This report completes our agreed upon scope of services as described in our proposal dated July 30, 2003. We appreciate the opportunity to provide service to you on this project. If you have any questions regarding this report, please contact the undersigned Respectfiolly submitted, SLADDEN ENGINEERING D Brett L. Anderson* w Principal Engineer SER/pc Copies: 6/La Costa Resort and Spa Sladden Engineering GEOTECHNICAL INVESTIGATION PROPOSED RESORT VILLAS LA COSTA RESORT & SPA COSTA DEL MAR ROAD CARLSBAD, CALIFORNIA November 11, 2003 TABLE OF CONTENTS INTRODUCTION 1 SCOPE OF WORK i PROJECT DESCRIPTION 1 REGIONAL SEISMICITY 2 LIQUEFACTION 2 SUBSURFACE CONDITIONS 2 CONCLUSIONS AND RECOMMENDATIONS 3 Foundation Design 4 Settlements 4 Lateral Design 4 Retaining Walls 4 Expansive SoUs 4 Concrete Slabs-on-Grade 5 Soluble Sulfates 5 Tentative Pavement Design 5 Shrinkage and Subsidence 6 General Site Grading 6 1. Clearing and Demohtion 6 2. Preparation of Building and Foundation Areas 6 3. Placement of Compacted FiU 6 4. Preparation of Slab and Pavement Areas 7 5. Testing and Inspection 7 GENERAL 7 APPENDIX A - Site Plan & Boring Logs Field Exploration APPENDIXB- LaboratoryTesting Laboratory Test Results APPENDIX C - 1997 UBC Seismic Design Criteria \ Sladden Engineering November 11, 2003 -1- Project No. 444-3161 03-10-183 INTRODUCTION This report presents the results of a Geotechnical Investigation performed in order to provide recommendations for the design and construction of the proposed resort villas and the various associated site improvements. The La Costa Resort & Spa is located on the northeast corner of El Camino Real and Costa Del Mar Road in the City of Carlsbad, Cahfornia. It is proposed to construct several multi-unit resort/residential buildings within the central portion of the La Costa Resort and Spa complex. It is our txnderstanding that the proposed resort vUlas wiU consist of 2 or 3 story structures with subterranean parking levels. The plans indicate that the project wiU include reconfigured driveways, walkways and parking areas and other related site improvements. A preliminary site plan provided by the KSL Development Corporation was used dviring our investigation. SCOPE OF WORK The purpose of our investigation was to determine certain engineering characteristics of the near surface soils on the site in order to develop recommendations for foundation design and site preparation. Our investigation included field exploration, laboratory testing, Uterature review, engineering analysis and the preparation of this report. Evaluation of hazardous wastes was not within the scope of services provided. Our investigation was performed in accordance with contemporary geotechnical engineering principles and practice. We make no other warranty, either e.xpress or implied. PROJECT DESCRIPTION The La Costa Resort and Spa complex is located on the northeast corner of El Camino Real and Costa Del Mar Road in the City of Carlsbad, CaUfornia. The proposed project wUl include the construction of 11 resort/residential buildings along with various associated site improvements. The associated tmprovements will include reconfigvired walkways, driveways and parking areas, landscaped areas and underground utiUties. It is our understanding that the proposed resort/residential bmldings will be of relatively Ughtweight wood-frame and/or steel frame construction and wiU include subterranean parking levels. The proposed resort/residential buUdings will be supported by conventional shallow spread footings and concrete slabs on grade. Based upon preliminary foundation loading information provided by KSL, we assumed isolated column loads of up to 100 kips and waU loads of up to 5.0 kips per linear foot for the resort villas buildings. We also assumed isolated column loads of up to 50 kips and waU loads of up to 3.0 kips per linear foot for the proposed spa buUding. Grading is assumed to include excavation for the proposed subterranean parking levels along with cutting and filling of the surface soils to construct level building pads and to provide for proper site drainage. The proposed resort villas will be constructed within the central portion of the La Costa Resort and Spa complex in the vicinity of the new spa and ballroom buildings. The majority of the proposed resort villas locations are concentrated within existing landscape areas but some existing structures and improvements wUl be removed to accommodate the new buUdings. The proposed buUding sites and adjacent areas slope gently downward towards the south but some areas include irregular topography related to previous grading and landscaping. There are several existing buUdings in the area including the new ballroom and spa buUdings as weU as several older structures. There are numerous underground utUities servicing the existing buUdings and transecting the new building areas. ^Irt/i/ian Pttnittoorrttrt November 11, 2003 "2- Project No. 444-3161 03-10-183 REGIONAL SEISMICITY A computer program was utUized to compUe data related to earthquake fault zones in the region and related seismic activity that may affect the site. E.Q. Fault Version 3.00 (Blake 2000) provides a compUation of data related to earthquake faults in the region. The program searches avaUable databases and provides both distances to causitive faults and the corresponding accelerations that may be experienced on the site due to earthquake activity along these faults. The attenuation relationship utihzed for this project was based upon Boore (1997) attenuation curves. The output data from this program is included in Appendix C. The mformation generated was utUized in our liquefaction evaluation As indicated on the summary page ofthe E.Q. Fault output data, the Rose Canyon fault is the closest to the site (approximately 8.8 kUometers). The Newport-Inglewood (offshore) faiUt is located approximately 16.8 kilometers west of the site. The maximum site acceleration is estimated to be 0.332g. This acceleration is based upon a maximum event of magiUtude 6.9. LIQUEFACTION Liquefaction occurs with sudden loss of soU strength due to rapid increases in pore press\ires within cohesionless soUs as a result of repeated cychc loading during seismic events. Several conditions must be present for Uquefaction to occur including; the presence of relatively shaUow groundwater, generaUy loose soUs conditions, the susceptibUity of soUs to Uquefaction based upon grain-size characteristics and the generation of sigiuficant and repeated seismicaUy induced ground accelerations. Liquefaction affects primarily loose, uiuform grained cohesionless sands with low relative densities. As previously indicated the soUs underlying the site consist primarily of a thin layer of sUty clays and clayey silts overlying dense sUty sands. Groundwater was encountered at varying depths within several of our borings. The variable groundwater depths suggest that the water encountered perched may be perched groundwater concentrated within more permeable sUty sand and silt layers Based upon the prominence of non-Uquefiable sUts and clays and the dense conditions of the sUty sand layers, it is our opinion that the potential for Uquefaction occurring beneath the site is neghgible. SUBSURFACE CONDITIONS The site soUs consist primarily of a surface layer of silty clays and clay.ey sands overlying native silty sands, sandy sUts, silty clays and clayey silts. Silty clays and clayey sands were encountered within the upper 5 to 10 feet within the majority of our borings. The near siirface sUty clay layers were underlain primarily by dense silty sand, sandy sUt and sUty clay layers. The site soUs appeared fairly consistent in composition but very inconsistent in stratigraphy due to the varying grades across the site. The native soUs underlying the site were found to be firm throughout the depth of each of our borings. The relatively undisturbed samples obtained indicated dry density varymg from 93 to 123 pcf. Sampler penetration resistance indicates that density within the underlying native soUs generally increases with depth. The soUs were found to be moist throughout the depth of our borings but some nearly saturated soils were encountered. Laboratory testing indicates moisture content varying from 1.0 to 37.0 percent. .'Hn/idon Rnoinccrino November 11, 2003 -3- Project No. 444-3161 03-10-183 Laboratory testing indicates that the surface soils consist primarUy of sUty clays that were found to be moderately expansive. Expansion testing indicates an expansion index of 81 for the sUty clays that fails within the "medium" expansion category in accordance with the Uniform BuUding Code classification system. ConsoUdation testing indicates that the majority of the site soUs are susceptible to only minor consoUdation and/or compression related settlements. Groundwater was encountered within several of our borings at depths as shaUow as 9 feet below the existing ground surface. The lack of groundwater within several of our borings suggests that the groundwater encountered was perched groundwater concentrated within more permeable layers. The possible presence of groundwater should be considered in foundation design and may impact construction. CONCLUSIONS AND RECOMMENDATIONS Based upon our field investigation and laboratory testing, it is ovir opinion that the proposed resort residential vUIas are feasible from a soU mechanic's standpoint provided that the recommendations included in this report are considered in building foundation design and site preparation. Due to the somewhat inconsistent condition of the near surface soUs and the possibUity of cut/fiU transitions in some of the proposed buUding areas, remedial grading including overexcavation and recompaction of the primary foundation bearing soils is recommended. It is our opinion that remedial grading within the proposed buUding areas should include the removal and recompaction of any compressible surface soils as weU as the primary foundation bearing soUs. Specific recommendations for site preparation are presented in the Site Grading section of this report. Groundwater was encountered within several of our borings at depths as shaUow as 9 feet below the existing ground surface. Due to the dense condition of the sandy soUs underlying the site, the potential for liquefaction affecting the site is considered to be neghgible. In our opinion, liquefaction related mitigation measures in addition to the site grading and foundation design recommendations included in this report shoiUd not be necessary. The site is located in a seismically active area as is aU of Southern CaUfornia. Design professionals should be aware of the site setting and the potential for earthquake activity during the anticipated life of the structure should be acknowledged. The accelerations that may be experienced on the site (as previously discussed) should be considered in design. Seismic design parameters as outlined in the 1997 UBC are summarized in Appendix C. Caving did not occur within our borings but the potential for caving should be considered within deeper excavations. All excavations should be constructed in accordance with the normal CalOSHA excavation criteria. On the basis of our observations of the materials encountered, we anticipate that the near surface clayey sUts and sUty sands wiU be classified by CalOSHA as Type B and Type C soUs, respectively. SoU conditions should be verified in the field by a "Competent person" employed by the Contractor. The surface soils encountered during our investigation were found to be moderately expansive. Laboratory testing indicated an Expansion Index of 81 for the near surface silty clays and clayey silts which corresponds with the "medium" expansion category in accordance with UBC Standard 18- 2. Special expansive soU design criteria as outUned in the Uniform Building Code should not be the controUing factor in the design of foundations and slabs on grade for this project but should be considered in design. nt M a a vi H n November 11, 2003 -4- ProjectNo. 444-3161 03-10-183 The following recommendations present more detaUed design criteria that have been developed on the basis of our field and laboratory investigation. Foimdation Design: The resiUts of our investigation indicate that either conventional shallow continuous footings or isolated pad footings that are supported upon properiy recompacted soUs, may be expected to provide satisfactory support for the proposed residential structmre foundations. Footings should extend at least 18 inches beneath lowest adjacent grade. Isolated square or rectangular footings at least 2 feet square may be designed using an aUowable bearing pressiire of 2500 pounds per square foot. Continuous footings at least 12 inches wide may be designed using an aUowable bearing value of 2000 pounds per square foot. The aUowable bearing pressures may be increased by 200 psf for each additional one foot of width and 250 psf for each additional 6 inches of depth, tf desired. The maximum aUowable bearing pressure should be 3000 psf. The allowable bearing pressures are for dead and frequently appUed Uve loads and may be increased by 1/3 to resist wind, seismic or other transient loading. Drainage from the building area should be rapid and complete. The recommendations provided in the preceding paragraph are based on the assumption that all footings will be supported upon properly compacted soU. All grading should be performed under the testing and inspection of the SoUs Engineer or his representative. Prior to the placement of concrete, we recommend that the footing excavations be inspected in order to verify that they extend into compacted soU and are free of loose and disturbed materials. Settlements: Settlements resiUting from the anticipated foundation loads and fiU placement are expected to be minimal. We estimate that ultimate settlements should be less than one inch when using the recommended foundation bearing values. As a practical matter, differential settlements between footings can be assumed as one-half of the total settlement. Lateral Design: Resistance to lateral loads can be provided by a combination of friction acting at the base of the slabs or foundations and passive earth pressure along the sides of the foundations. A coefficient of friction of 0.40 between soil and concrete may be used with dead load forces only. A passive earth pressure of 250 pounds per square foot, per foot of depth, may be used for the sides of footings that are poured against properly compacted native soils. Passive earth pressure should be ignored within-the upper 1 foot except where confined (such as beneath a floor slab). Retaining WaUs: Retaining waUs wiU be necessary to accomplish the proposed construction. Lateral pressures for use in cantUever retaining waU design may be estimated using an equivalent flmd weight of 40 pcf for level drained native backfiU conditions. For waUs that are to be restrained at the top (such as the subterranean parking level walls), the equivalent fluid weight should be increased to 60 pcf for level drained native backfUI conditions. Backdrains should be provided for the full height of the walls. The recommended lateral pressures should also be appUcable for use in the design of temporary shoring systems, tf required Expansive SoUs: Due to the presence of "medium" expansion category soUs near the surface throughout the majority of the site, special expansive soU design criteria shoiUd be considered in the design of foundations and concrete slabs-on-grade. Due to the somewhat variable conditions, expansion potential should be reevaluated after grading. \ Sladden Rnmneerinf November 11, 2003 -5- Project No. 444-3161 03-10-183 Concrete Slabs-on-Grade: All siirfaces to receive concrete slabs-on-grade should be underlain by a minimum compacted fill thickness of 12 inches, placed as described tn the Site Grading Section of this report. Where slabs are to receive moisture sensitive floor coverings or where dampness of the floor slab is not desired, we recommend the use of an appropriate vapor barrier or an adequate capiUary break. Vapor barriers should be protected by sand in order to reduce the possibility of puncture and to aid in obtaining uniform concrete curing. Reinforcement of slabs-on-grade in order to resist expansive soil pressures wiU Ukely be necessary. Slab reinforcement wUl also have a beneficial effect in containing cracking due to concrete shrinkage. Temperature and shrinkage related cracking should be anticipated in aU concrete slabs-on-grade. Slab reinforcement and the spacing of control joints should be determined by the Structural Engineer based upon post-grading expansion test results. Soluble Sulfates: The soluble sulfate concentrations of the smface soUs were determined to be 774 and 1832 parts per mUlion (ppm) which is considered potentially corrosive with respect to concrete. The use of Type V cement and speciahzed sulfate resistant concrete mix designs may be necessary. The soluble siUfate content of the smface soils shoiUd be reevaluated after grading and appropriate concrete mix designs should be determined based upon post-grading test results. Tentative Pavement Design: All paving shoiUd be underlain by a minimum compacted fiU thickness of 12 inches (excluding aggregate base). This may be performed as described in the Site Grading Section of this report. Based upon the smface soU conditions observed, an R- Value of approximately 30 is expected. Based upon a design R-Value of 30, a preUminary pavement design section of 3.0 inches of asphalt on 6.0 inches of Class 2 base material is recommended for parking areas and areas Umited to auto and Ught truck traffic (Traffic Index = 5.0). In driveway areas and areas where heavy truck traffic is expected (Traffic Index = 6.5), the pavement section should be increased to 4.0 inches of asphalt on 6.0 inches of base material. Pavement should be confined by cmbs. Subgrade should be compacted to at least 90 percent and base material should be compacted to at least 95 percent of maximum density. Final design for asphalt pavement should be based upon R-Value testing performed after rough grading. Aggregate base should conform to the reqiUrements for Class 2 Aggregate Base in Section 26 of CalTrans Standard Specifications, January, 1992. Asphaltic concrete should conform to Section 39 of the CalTrans Standard Specifications. The recommended sections shoiUd be provided with a uniformly compacted subgrade and precise control of thickness and elevations during placement. Drainage from paved areas should be rapid and complete. It should be noted that the pavement sections recommended above are minimum sections, tf heavily loaded vehicles are expected to cross automobUe parking and driving areas, thicker pavement sections should be considered in these locations. Pavement design sections are tentative and should be confirmed at the completion of site grading when the subgrade soUs are in-place. This wiU include sampUng and testing of the actual subgrade soils and an analysis based upon the specific use. .^Inddet, Pnoineprino November 11, 2003 -6- Project No. 444-3161 03-10-183 Shrinkage and Subsidence: Volumetric shrinkage of the material that is excavated and replaced as controUed compacted fiU should be anticipated. We expect that the shrinkage could vary from 10 to 15 percent. Subsidence of the smfaces that are scarified and compacted should be between 1 and 2 tenths of a foot. This wUl vary depending upon the type of eqmpment used, the moistme content of the soU at the time of grading and the actual degree of compaction attained durtng grading. These values for shrinkage and subsidence are exclusive of losses that wUl occm due to the site clearing, buUding demoUtion and the removal of unsuitable materials. General Site Grading: AU grading should be performed in accordance with the grading ordinance of the City of Carlsbad, Cahfornia. The foUowing recommendations have been developed on the basis of our field and laboratory testing: 1. Clearing and DemoUtion: Proper clearing wUl be very Unportant. AU previous pavements, slabs, foimdations, trees and the associated root systems should be removed from the buUding areas. Underground utUities should also be removed from the buUding areas. SoUs that are distmbed during site clearing and demoUtion operations should be removed and replaced as controUed compacted fUl under the direction of the SoUs Engineer. 2. Preparation of BuUding and Foundation Areas: The remedial grading recommended should include the overexcavation and recompaction of any compressible smface soUs as weU as the primary foundation bearing soils tn order to provide uniform foundation support. Removals within the buUding areas should extend to a minimum depth of 3 feet below existing grade or 3 feet below the bottom of the footings, whichever is deeper. Subsequent to excavation, the exposed soUs should be scarified to a depth of 1-foot, moistme conditioned and recompacted to at least 90 percent relative compaction. Once cleaned of unsmtable material, the excavated soUs may then be replaced as controUed compacted fiU. 3. Placement of Compacted FiU: FUl materials consisting of on-site soUs or approved import soUs should be spread in shallow Ufts at near optunum moisture content and compacted to a minimum of 90 percent relative compaction. Imported fiU material shaU be of equal or greater quaUty than the native surface soUs. The contractor shaU notify the SoUs Engineer at least 48 hours in advance of importing soUs in order to provide sufficient time for the evaluation of proposed import materials. The contractor shaU be responsible for deUverUig material to the site that complies with the project specifications. Approval by the SoUs Engineer wUl be based upon material delivered to the site and not the preUminary evaluation of import sources. Our observations of the material encountered dming om investigation indicate that compaction wUl be most readUy obtained by means of heavy rubber tired grading equipment and sheepsfoot compactors. A untform and near optimum moisture content should be maintained during fiU placement and compaction. C1..JJ. November 11, 2003 -7- Project No. 444-3161 03-10-183 4. Preparation of Slab and Paving Areas: AU surfaces to receive asphalt or concrete paving and exterior concrete slabs-on-grade should be underlain by a minimum compacted fiU thickness of 12 Uiches. This may be accomplished by a combination of overexcavation, scarification and recompaction of the smface soUs, and the placement of the excavated material as compacted engineered fiU. Compaction of the concrete slab sureas should be to a mimmum of 90 percent relative compaction. Compaction within the proposed pavement areas should be to a minimum of 95 percent relative compaction. 5. Testing and Inspection: DmUig grading tests and observations should be performed by the SoUs Engineer or his representative in order to verify that the grading is being performed in accordance with the project specifications. Field density testing shaU be performed in accordance with applicable ASTM test standards. The minimum acceptable degree of compaction shaU be 90 percent of the maximum dry density as obtained by the ASTM D1557-91 test method. Where testing indicates insufficient density, additional compactive effort shall be appUed untU retesting indicates satisfactory compaction. GENERAL The findings and recommendations presented in this report are based upon an interpolation of the soU conditions between boring locations and extrapolation of these conditions throughout the proposed buUding area. Should conditions encountered during grading appear different than those indicated tn this report, this office should be nottfied. This report is considered to be appUcable for use by La Costa Resort and Spa for the specific site and project described herein. The use of this report by other parties or for other projects is not authorized. The recommendations of this report are contingent upon monitoring of the grading operations by a representative of Sladden Engineering. AU recommendations are considered to be tentative pending our review of the grading operations and additional testing, if indicated. If others are employed to perform any soU testing, this office should be notified prior to such testing in order to coordinate any required site visits by om representative and to assure indemnification of Sladden Engineering. We recommend that a pre-job conference be held on the site prior to the initiation of site grading. The purpose of this meeting wiU be to assure a complete understanding of the recommendations presented in this report as they apply to the actual grading performed. APPENDIX A Site Plan Borings Logs \ Sladden Engineering APPENDIX A FIELD EXPLORATION For om field investigation, 11 exploratory borings were excavated on September 3 and 4, 2003, using a truck mounted hoUow stem auger rig (Mobile B61). The approximate boring locations are indicated on the site plan included in this appendix. Continuous logs of the materials encountered were prepared dming drUling by a representative of Sladden Engineering. Boring logs are included in this appendix. Representative undisturbed samples were obtained within om borings by driving a thin-waUed steel penetration sampler (CaUfornia spUt spoon sampler) or a Standard Penetration Test (SPT) sampler with a 140-pound hammer dropping approximately 30 inches (ASTM D1586). The number of blows requtred to drive the samplers 18 inches was recorded in 6-inch increments and blowcounts are indicated on the boring logs. The Cahfornia samplers are 3.0 inches in diameter, carrying brass sample rings having inner diameters of 2.5 inches. The standard penetration samplers are 2.0 inches in diameter with an inner diameter of 1.5 inches. Undistmbed samples were removed fi:om the sampler and placed in moistme sealed containers in order to preserve the natmal soil moistme content. Bulk samples were obtained frnm the excavatton spoUs and samples were then transported to om laboratory for further observations and testing. Samples were then transported to om laboratory for fmther observations and testing. \ Sladden Engineering .i:.- • ^ i-l ; r- > O O 05 H > 5 m > , i< im H > O H > TJ Approximate Boring Locations Boring Location Map La Costa Resort N.E.C. El Camino Real & Costa Del Mar Road Carlsbad, California Sladden Engineering Project Number: 544-3161 Date: 11-10-03 La Costa Resort N.E.C. El Camino Real & Costa Del Mar Road / Carlsbad, California Date: 9-3-03 Boring No. 1 - Lot 10 •Iob No.: 444-3161 a*- c o m DESCRIPTION a. '3 tZ) Q D 3 e .>-2 Pi B ^6 REMARKS Silty Clay: Brown, slightly sandy CL i 10 15 20 25 30 35 40 45 50 55 i- 10/13/19 18/26/37 15/16/21 118 Silty Clay; Brown with interbedded silty clayey sand layers CL 118 Silty Clay: Brown, slightly sandy CL 116 21/35/38 I I I I I Silty Clay: Brown with interbedded silty clayey sand layers CL 105 1/22/25 0/14/20 6/9/13 9/11/16 12/14/15 Clayey Sand: Brown, slightly silty, fine grained SC Silty Clay: Brown with very silty sand layer 4" thick Silty Clay: Brown Silty Clay: Brown, slightly sandy Silty Clay: Brown 11/13/21 CL CL CL CL 82% passing #200 82% passing #200 14 86% passing #200 85% passing #200 23 25 28 21 30 39% passing #200 91% passing #200 3% passing #200 87% passing #200 89% passing #200 95% passing #200 im Recovered Sample I [ I Standard Penetration Sample Note: The stratification lines .represent the approximate bi^undaries between the soil types: the transitions may be gradual. Total Depth = 51.5' No Bedrock No Groundwater La Costa Resort N.E.C. El Camino Real & Costa Del Mar Road / Carlsbad, California Date: 9-3-03 Boring No. 2 - Lot ll Job No.: 444-3161 & o JS E >> c/3 VO O DESCRIPTION a H • 'o Cfl Q 3 3 9J S Si .2 a> CL. REMARKS Clayey Sand: Brown, slightly silty, fine grained SC Z 10 15 20 25 30 35 40 45 50 55 i- 12/17/20 3/40/45 123 Silty Clay: Brown, sandy CL 121 r 21/33/30 Clayey Sand: Brown, slightly silty SC I I 7/20/36 15/27/36 15/22/35 115 103 Sand: Grey brown, fine grained trace silt, trace clay SP 44% passing #200 79% passing #200 38% passing #200 26% passing #200 14% passing #200 16%) passing #200 Recovered Sample I J |.Standard Penetration Sample \ Total Depth = 31.5' No Bedrock No Groundwater Note: The stratification lines represent the approximate boundaries between the soil types; the transitions may be gradual. Date: 9-3-03 La Costa Resort N.E.C. El Camino Real & Costa Del Mar Road / Carlsbad, California Boring No. 3 - Lot 15 Job No.: 444-3161 — 4) c vo Cfl o DESCRIPTION <u 'o >1 Q D 3 3 O a REMARKS Silty Clay: Brown, slightly sandy CL Scattered tree roots 10 15 20 25 30 35 40 45 50 55 n 12/13/17 14/20/27 23/33/37 112 83% passing #200 Silty Clay; Brown, sandy CL I 17/23/24 11/19/26 16/50-5" Clayey Sand: Brown, very clayey, silty, fine grained SC Silty Sand; Grey brown, fine grained SM Sand: Grey brown, fine grained SP 120 86% passing #200 115 46% passing #200 21% passing #200 6% passing #200 [B Recovered Sample Unrecovered Sample Standard Penetration Sample Total Depth = 31.5' No Bedrock No Groundwater Note: The stratification lines represent the approximate boundaries between the soil types; the transitions may be gradual. La Costa Resort N.E.C. El Camino Real & Costa Del Mar Road / Carlsbad, California Date: 9-3-03 Boring No. 4 - Lot 14 Job No.: 444-3161 o ja E Cfl s vo Cfl o s DESCRIPTION a H 'o Ofl a; 3 O B _« S3 S REMARKS Silty Clay; Brown with interbedded silty clayey sand layers CL 5/10/16 112 19 10 15 20 25 30 35 40 45 50 55 9/13/18 Silty Clay; Brown, slightly sandy CL 107 14/20/27 14/24/30 Clayey Silt; Brown, sandy I I Silty Sand; Grey brown, fine grained 15/26/26 7/15/16 Sand; Grey brown, fine grained Silty Sand; Grey brown, fine grained ML 115 15 SM 94 SP SM 12 73% passing #200 84%) passing-#200 78% passing #200 19%) passing #200 6%) passing #200 26% passing #200 m Recovered Sample I Standard Penetration Sample \ Total Depth = 31.5' No Bedrock No Groundwater Note: The stratification lines represent the approximate boundaries between the soil types; the transitions may be gradual. La Costa Resort N.E.C. El Camino Real & Costa Del Mar Road / Carlsbad, California Date: 9-3-03 Boring i\o. 5 - Lot 8 Job No.: 444-3] 61 ~ O) a. •" Qo Cfl e vo CA o 5 DESCRIPTION 1) a '3 Cfl Q J3 3 4; « E REMARKS Clayey Sand: Brown, slightly silty, fine grained SC 10 15 20 25 30 35 40 45 50 Clayey Sand: Brown, fine to coarse grained, silty SC 102 23% passing #200 z 26/50-5" 19/30/37 15/15/15 7/10/13 Sand: Brown, slightly silty, slightly clayey, fine grained SP/SM 102 Sand: Grey brown, fine grained SP IOO I Silty Sand: Grey brown, fine grained SM 102 Silty Clay: Brown CL E I 7/9/9 8/9/8 8/17/19 8/7/17 7/14/19 Silty Clay; Brown with very silty fine grained sand layer 2" thick CL Silty Clay: Brown, stiff CL Silty Clay; Brown with very silty fine grained sand layer 2" thick CL Silty Clay: Brown, stiff CL 11% passing #200 3% passing #200 22 26% passing #200 37 37 91% passing #200 92% passing #200 \7 Groundwater (§ 33' 22 17 22 78% passing #200 93% passing #200 71% passing #200 21 92% passing #200 55 ^1 Recovered Sample [ [ I Standard Penetration Sample Note: The stratification lines represent the approximate boundaries between the soil types; the transitions may be gradual. Total Depth = 51.5' No Bedrock La Costa Resort N.E.C. El Camino Real & Costa Del Mar Road / Carlsbad, California Date: 9-3-03 Boring No. 6 - Lot 12 Job No.: 444-3161 JS « ~ ,0) QO o C >> Cfl vo Cfl o 5 DESCRIPTION 0) a. H '3 Cfl Q D 3 3 REMARKS Silty Clay: Brown, sandy CL r 9/13/23 108 10 15 20 25 30 35 40 45 50 55 9/12/16 Clayey Silt; Brown with thin interbedded silty fine to coarse grained sand layers ML 99 20 6/35/43 Silty Clay; Brown, sandy CL 114 16 i-20/34/50 I I Silty Clay; Brown, stiff CL 115 17 8/13/17 9/16/17 Clayey Silt: Brown with clayey, silty fine grained sand layer 6" thick ML 14 Silty Sand; Grey brown, fine grained SM 82% passing #200 67%) passing #200 85% passing #200 91%) passing #200 51% passing #200 19% passing #200 Recovered Sample I Standard Penetration Sample TotalDepth = 31.5' No Bedrock No Groundwater Note: The stratification lines represent the approximate boundaries between the soil types; the transitions may be gradual. La Costa Resort N.E.C. El Camino Real & Costa Del Mar Road / Carlsbad, California Date: 9-4-03 Boring No. 7 - Lot 16 Job No.: 444-3161 - 4) a"" QO o J2 E Cfl vo Cfl o 5 DESCRIPTION a H 'o Cfl >1 u Q D3 OJ 3 '3 « E REMARKS Clayey Sand: Brown, slightly silty, fine grained SC 10 15 20 25 30 35 40 45 SO 9/10/12 0/15/19 108 10 Clayey Sand; Brown, fine to coarse grained, silty SC 31/50-5' 118 121 10 10 I I 15/18/18 19/25/25 50-4" Sand; Brown, slightly silty, slightly clayey, fine grained SP/SM 107 16 Sand: Brown, slightly silty, slightly clayey, fine to coarse grained with gravel SP/SM 13 22% passing #200 24% passing #200 Groundwater @ 14' \/ 14% passing #200 19%) passing #200 13%) passing #200 Unrecovered sample IIH Recovered Sample UJ Standard Penetration Sample 55 Total Depth = 31.5' No Bedrock Note: The stratification lines represent the approximate boundaries berween the soil types; the transitions may be gradual. La Costa Resort N.E.C. El Camino Real & Costa Del Mar Road / Carlsbad, California Date: 9-4-03 Boring No. 8 - Lot 17 Job No.: 444-3161 JS a 4) q QO o .a £ cn vo Cfl o B DESCRIPTION O) a >> H '3 Cfl .ti a- D 3 3 '4J O. cs! E REMARKS Clayey Silt; Brown ML 16/17/8 100 21 10 15 20 25 30 35 40 45 50 55 11 9/9/12 ^•6/10/11 ^•5/7/8 I I I I 6/11/13 4/6/6 6/10/10 7/8/10 5/6/6 50-2" 85% passing #200 '\7 Groundwater @ 9' Silty Clay; Brown with slightly silty, slightly clayey sand layer layer 6" thick CL 108 71%) passing #200 Silty Clay; Brown, slightly sandy CL 114 16 87% passing #200 Silty Clay; Brown CL 111 17 19 16 21 93%) passing #200 94%) passing #200 91% passing #200 89%) passing #200 94%) passing #200 87% passing #200 Silty Clay: Brown, sandy CL 23 83% passing #200 m Recovered Sample I ^ I Standard Penetration Sample Note: The stratification lines represent the approximate boundaries between the soil types; the transitions may be gradual. Total Depth = 51.5' No Bedrock Date: 9-4-03 a 4) C Q O o X) E Cfl La Costa Resort N.E.C. EI Camino Real & Costa Del Mar Road / Carlsbad, California Boring No. 9 - Lot ll vo O 5 DESCRIPTION 01 o. H '3 Cfl Q fi a 13 3 3 es 41 O. cs! E S5c3 Job No.: 444-3161 REMARKS Silty Clay: Brown, sandy CL 6/9/1: 10 15 20 25 30 35 40 45 50 11 8/12/12 11! Ill 12 r 10/13/15 i Silty Clay: Brown with interbedded silty clayey sand layers 20/50-5" 2 I Clayey Sand; Brown, slightly silty, fine grained 19/24/24 25/50-5" Sand; Grey brown, slightly silty, fine grained CL 105 SC 98 SP/SM Asphalt 3" thick 82% passing #200 80% passing #200 68% passing #200 32%) passing #200 10% passing #200 11% passing #200 55 Recovered Sample [JU Standard Penetration Sample Total Depth = 31.5' No Bedrock No Groundwater Note: The stratification lines represent the approximate boundaries between the soi! types; the transitions may be gradual. La Costa Resort N.E.C. El Camino Real & Costa Del Mar Road / Carlsbad, California Date: 9-4-03 Boring No. 10 - Lot 7 Job No.: 444-3161 JS 4) ^ .4) a Q=§ Cfl vo Cfl o 5 DESCRIPTION a H '3 Cfl Q fi 5i D3 9i U 3 O .51 JS 53 Pi E REMARKS Silty Clay; Dark grey CL ^•6/9/13 115 15 10 15 20 25 30 35 40 45 50 55 r 10/17/26 16/19/29 Silty Clay; Brown, sandy CL 116 Silty Clay; Brown CL 96 25 20/17/21 I I Silty Clay: Dark grey CL 94 26 5/6/8 5/8/8 -Silty Clay: Brown CL 29 29 86% passing #200 75% passing #200 93% passing #200 97% passing #200 95% passing #200 Groundwater @ 27' \7 88% passing #200 ^1 Recovered Sample [JU Standard Penetration Sample \ Total Depth = 31.5' No Bedrock Note: The stratification lines represent the approximate boundaries between the soil types; the transitions may be gradual. La Costa Resort N.E.C. El Camino Real & Costa Del Mar Road / Carlsbad, California Date: 9-4-03 Boring No. 11 - Lot 5 Job No.: 444-3161 O) C Qo o J2 E Cfl z G VO Cfl DESCRIPTION 4) a. >> H '3 Cfl Q .1= o fi y :33 4) — cs '4J Q, C2! E REMARKS Silty Clay: Brown CL r 8/11/15 108 17 10 15 20 25 30 35 40 45 50 55 10/35/30 17/24/30 121/24/30 Sand; Brown, slightly silty, slightly clayey, fine grained SP/SM 119 Sand; Grey brown, slightly silty, fine grained SP/SM 93 1 Sand; Grey brown, fine grained SP 97 7/9/22 7/9/9 Silty Clay; Brown, stiff CL Silty Clay; Brown, sandy CL 29 87%. passing #200 15% passing #200 1% passing #200 4%) passing #200 91% passing #200 Groundwater @ IT 82% passing #200 m Recovered Sample I ^ I Standard Penetration Sample Total Depth = 31.5' No Bedrock Note: The stratification lines represent the approximate boundaries between the soil types; the transitions may be gradual. APPENDIX B Laboratory Testing Laboratory Test Results \ Sladden Engineering APPENDIX B LABORATORY TESTING Representative bulk and relatively undistmbed soU samples were obtained in the field and retmned to om laboratory for additional observations and testing. Laboratory testing was generaUy performed in two phases. The first phase consisted of testing in order to determine the compaction of the existing natmal soU and the general engineering classifications of the soUs underlying the site. This testing was performed in order to estunate the engineering characteristics of the soU and to serve as a basis for selecting samples for the second phase of testing. The second phase consisted of soU mechanics testing. This testing including consoUdation, shear strength and expansion testing was performed in order to provide a means of developing specific design recommendations based on the mechanical properties of the soU. CLASSIFICATION AND COMPACTIONTESTING Unit Weight and Moistme Content Determinations: Each undistmbed sample was weighed and measured in order to determine its unit weight. A small portion of each sample was then subjected to testing in order to determine its moisture content. This was used in order to determine the dry density of the soU in its natural condition. The results of this testUig are shown on the Boring Logs. Maximum Density-Optimum Moistme Detenrunations: Representative soU types .were selected for maximum density determinations. This testUig was performed in accordance with the ASTM Standard D1557-91, Test Method A. The results of this testing are presented graphicaUy in this appendbc. The maximum densities are compared to the field densities of the soU in order to determine the existUig relative compaction to the soU. This is shown on the Boring Logs, and is useful in estimating'the strength and compressibihty ofthe soU. Classification Testing: SoU samples were selected for classification testing. This testing consists of mechanical grain size analyses and Atterberg Limits determinations. These provide information for developing classifications for the soU in accordance with the Unified Classification System. This classification system categorizes the soU into groups having similar engineering characteristics. The results of this testing are very useful Ui detecting variations in the soUs and in selecting samples for fmther testing. SOIL MECHANIC'S TESTING Dkect Shear Testing: Three bulk samples were selected for Direct Shear Testmg. This testing measmes the shear strength of the soU under various normal pressures and is used in developing parameters for foundation design and lateral design. Testing was performed using recompacted test specimens, which were saturated prior to testing. Testing was performed using a strain controUed test apparatus with normal pressmes ranging from 800 to 2300 pounds per square foot. Expansion Testing: Three bulk samples were selected for E.xpansion testing. Expansion testing was performed in accordance with the UBC Standard 18-2. This testing consists of remolding 4-inch diameter by l-inch thick test specimens to a moistme content and dry density corresponding to approximately 50 percent satmation. The samples are subjected to a smcharge of 144 pounds per square foot and allowed to reach equUibrium. At that point the specimens are inundated with distiUed water. The linear expansion is then measmed untU complete. ConsoUdation Testing: Eight relatively undistmbed samples were selected for consoUdation testing. For this testing one-inch thick test specimens are subjected to vertical loads varying from 575 psf to 11520 psf appUed progressively. The consoUdation at each load increment was recorded prior to placement of each subsequent load. The specimens were satmated at the 575 psf or 720 psf load increment. h \ Sladden Ensineerim Max imum Density/Optimum Moisture ASTM D698/D1557 Project Number: 444-3161 Project Name: Lab ID Number: Sample Location: Description: Maximum Density: Optiraum Moisture La Costa Villas Bulk 1 @ 15-20' Sandy Silt with Traces of Clay 123 pcf 9% October 3, 2003 ASTMD-1557 A Rammer Type: Machine Sieve Size % Retained 3/4" 3/8" #4 Moisture Content, %o c ' LJ C- Project Number: Project Name: Lab ID Number: Sample Location: Bulk 3 @, 25-30' Description: Sand Maximum Density: 107 pcf Optimum Moisture 8% Maximum Density/Optimum Moisture ASTM D698/DI557 444-3161 La Costa Villas October 3, 2003 ASTMD-1557 A Rammer Type: Machine Sieve Size % Retained 3/4" 3/8" #4 Maximum Density/Optimum Moisture ASTM D698/D1557 Project Number: 444-3161 Project Name: Lab ID Number: Sample Location: Descnption: Maximum Density: Optimum Moisture La Costa Villas Bulk 7 1-5' Silty Sand with Traces of Clay 116 pcf 12% October 3, 2003 ASTMD-1557 A Rammer Type; Machine Sieve Size % Retained 3/4" 3/8" #4 \ Direct Sliear ASTM D 3080-90 (modified for unconsolidated, undrained conditions) Job Number 444-3161 October 3, 2003 Job Name La Costa Villas Lab ID No. Sample ID Bulk 1 @ 0-5' Classification Sandy Silt with Traces of Clay Sample Type Remolded @ 90% of Maximum Density Initial Dry Density: 112.0 pcf Initial Mosture Content: 9.0 % Peak Friction Angle (0): 34° Cohesion (c): 90 psf Test Results 1 2 3 4 Average Moisture Content, % 16.5 16.5 16.5 16.5 16.5 Saturation, % 88.5 88.5 88.5 88.5 88.5 Nonnal Stress, kips 0.151 0.301 0.603 1.206 Peak Stress, kips 0.135 0.351 0.504 0.891 • Peak Stress Linear (Peak Stress) 1.2 • 1.0 - 1.2 • 1.0 - 4 1.2 • 1.0 - 4 0.8 - 4 0.8 - 4 • Stress o bv 4 • Stress o bv ^— ! 4 CS .c Cfl 0.4 - 1 ] 4 CS .c Cfl 0.4 -1 4 0.2 - 0.0 - < i ! 4 0.2 - 0.0 - 1 4 0.2 - 0.0 - i • 1 4 0.2 - 0.0 - 4 0.0 0.2 0.4 0. r 6 0. '^ormaI Stress 8 1. 0 1. 2 1. 4 Direct Shear ASTM D 3080-90 (modified for unconsolidated, undrained conditions) Job Number 444-3161 October 3, 2003 Job Name La Costa Villas Lab ID No. Sample ID Bulk 3 (§25-30 Classification Sand Sample Type Remolded @ 90% of Ma.ximum Density Initial Dry Density: 95.1 pcf Initial Mosture Content: 8.0 % Peak Friction Angle (0): 37° Cohesion (c): 130 psf Test Results 1 2 3 4 Average Moisture Content, % 26.6 26.6 26.6 26.6 26.6 Saturation, % 93.1 93.1 93.1 93.1 93.1 Normal Stress, kips 0.151 0.301 0.603 1.206 Peak Stress, kips 0.099 0.405 0.765 0.954 • Peak Stress Linear (Peak Stress) 1.2 - 1.0 - 4 1.0 - 4 0 8- 1 4 0 8- 4 Stress 3 < 4 Stress 3 < , 4 Shear 4 Shear 1 --^ 4 0.2 - 4 0.2 - 4 0 0 - —m— 4 0 0 - 4 0.0 0. 2 0. 4 0. r 6 0. *(ormal Stress 8 1. 0 1. 2 1. 4 \ Direct Shear ASTM D 3080-90 (modified for unconsolidated, undrained conditions) Job Number 444-3161 October 3, 2003 Job Name La Costa Villas Lab ID No. Sample ID Bulk 7 @ 0-5' Classification Silty Sand with Traces of Clay Sample Type Remolded @ 90% of Maximum Density Initial Dry Density: 102.3 pcf Liitial Mosture Content: 12.0 % Peak Friction Angle (0): 26° Cohesion (c): 80 psf Test Results 1 2 3 4 Average Moisture Content, % 24.4 24.4 24.4 24.4 24.4 Saturation, % 101.5 101.5 101.5 101.5 101.5 Normal Stress, kips 0.151 0.301 0.603 1.206 Peak Stress, kips 0.162 0.207 0.396 0.675 • Peak Stress Linear (Peak Stress) 1.2 - 1.0 - 0.8 - 1 4 1.0 - 0.8 - 4 1.0 - 0.8 - 4 1.0 - 0.8 - 4 • Stress o bv 4 • Stress o bv 4 cs u J= Cfl 0.4 - 4 cs u J= Cfl 0.4 - 4 0.2 - 4 0.2 - 4 0.0 - 4 0.0 -1 4 0.0 0.2 0. 4 0. r 6 0. 'formal Stress 8 1. 0 1-2 1. 4 One Dimensional Consolidation ASTM D2435 & D5333 Job Number: 444-3161 Job Name: La Costa Villas Sample ID: Boring 1 15' Soil Description: Sandy Silt October 3, 2003 Initial Dry Density, pcf: 114.5 Initial Moisture, %: 14 Initial Void Ratio: 0.456 Specific Gravity: 2.67 % Change in Height vs Normal Presssure Diagram -2 -3 -9 •10 0.0 • Before Saturation • Rebound 1.0 2.0 •After Saturation •Hydro Consolidation 3.0 —1— 4.0 5.0 6.0 7.0 \ One Dimensional Consolidation ASTM D2435 &. D5333 Job Number: 444-3161 Job Name: La Costa Villas Sample ID: Boring 1 @ 20' Soil Description: Silty Sand October 3, 2003 Initial Dry Density, pcf 105.1 Initial Moisture, %: 9 Initial Void Ratio: 0.587 Specific Gravity: 2.67 % Change in Height vs Normal Presssure Diagram • Before Saturation • Rebound •After Saturation •Hydro Consolidation i 1 i 1 1 1 j i—: 1 1 .... i .. i 1 - - _ -—i -9 -10 H 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 \ One Dimensional Consolidation ASTM D2435 & D5333 Job Number: 444-3161 October 3, 2003 Job Name: La Costa Villas Sample ID:' Boring 2 5' Soil Description: Silty Sand Initial Dry Density, pcf 122.8 Initial Moisture, %: 9 Initial Void Ratio: 0.357 Specific Gravity: 2.67 %> Change in Height vs Normal Presssure Diagram •Before Saturation • Rebound • Affer Saturation • Hydro Consolidation : : i i ! 1 • 1 i i i 1 1 •A 1 1 ! n 1 I 1 1 1 i -f3 -J_. 1 i 1 ^ 1 1 [ 1 1 — ! 1 1 1 -3 -9 •10 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 \ One Dimensional Consolidation ASTM D2435 & D5333 Job Number: 444-3161 Job Name: La Costa Villas Sample ID: Boring 2 (§10' Soil Description: Silty Sand October 3, 2003 Initial Dry Density, pcf 116.8 Initial Moisture, %: 11 Initial Void Ratio: 0.427 Specific Gravity: 2.67 % Change in Height vs Normal Presssure Diagram -4 -5 -6 -7 -9 -10 4 — Before Samration -9— Rebound •After Saturation • Hydro Consolidation 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 One Dimensional Consolidation ASTM D2435 & D5333 Job Number: 444-3161 Job Name: La Costa Villas Sample ID: Boring 3 (§15' Soil Description: Silty Sand October 3, 2003 Initial Dry Density, pcf 120.3 Initial Moisture, %: 12 Initial Void Ratio: 0.386 Specific Gravity: 2.67 % Change in Height vs Normal Presssure Diagram 0 -I. -2 -3 -4 -5 -6 -7 • Before Saturation •Rebound -TA:— After Saturation -•—Hydro Consolidation • 10 —I— 2.0 3.0 h 0.0 1.0 4.0 5.0 6.0 7.0 \ One Dimensional Consolidation ASTM D2435 & D5333 Job Number: 444-3161 Job Name: La Costa Villas Sample ID: Boring 3 @ 20' Soil Description: Sandy Silt October 3, 2003 Initial Dry Density, pcf 113.5 Initial Moisture, %: 15 Initial Void Ratio: 0.469 Specific Gravity: 2.67 % Change in Height vs Normal Presssure Diagram Before Saturation -Q— Rebound • After Saturation • Hydro Consolidation i One Dimensional Consolidation ASTM D2435 & D5333 Job Number: 444-3161 Job Name: La Costa Villas Sample ID: Boring 8 @ 15' Soil Description: Silty Sand October 3, 2003 Initial Dry Density, pcf 108.2 Initial Moisture, %: 16 Initial Void Ratio: 0.541 Specific Gravity; 2.67 Vo Change in Height vs Normal Presssure Diagram -1 -3 -6 -7 -9 -10 • Before Saturation. • Rebound •Tir- After Saturation -•—Hydro Consolidation 0.0 0.5 1.0 1.5 2.0 2.5 3.0 5.5 4.0 4.5 5.0 One Dimensional Consolidation ASTM D2435 & D5333 Job Number: 444-3161 Job Name: La Costa VUlas Sample ID: Boring 8 @ 20' Soil Description: Silty Sand October 3, 2003 Initial Dry Density, pcf 110.6 Initial Moisture, %: 18 Initial Void Ratio: 0.507 Specific Gravity: 2.67 % Change in Height vs Normal Presssure Diagram j —0—Before Saturation i O Rebound • After Saturation • Hydro Consolidation 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 One Dimensional Consolidation ASTM D2435 & D5333 Job Number: 444-3161 Job Name: La Costa Villas Sample ID: Boring 10 @ 15' Soil Description: Silty Clay October 3, 2003 Initial Dry Density, pcf 94.3 Initial Moisture, %: 25 Initial Void Ratio: 0.767 Specific Gravity: 2.67 1 T -3 -4 -5 -6 -9 -- •10 -I- 0.0 %> Change in Height vs Normal Presssure Diagram • Before Saturation • Rebound 1.0 2.0 •After Saturation •Hydro Consolidation 3.0 4.0 5.0 6.0 7.0 One Dimensional Consolidation ASTMD2435 &D5333 Job Number: 444-3161 Job Name: La Costa Villas Sample ID: Boring \0@20' Soil Description: Silty Clay October 3,2003 Initial Dry Density, pcf 92.2 Initial Moisture, %: 26 Initial Void Ratio: 0.807 Specific Gravity: 2.67 % Change in Height vs Normal Presssure Diagram -2 -5 -6 -10 0.0 -^Before Saturation Rebound •After Saturation • Hydro Consolidation 1.0 2.0 3.0 4.0 5.0 6.0 7.0 \ O I _ J J T-'.. One Dimensional Consolidation ASTM D2435 & D5333 Job Number: 444-3161 Job Name: La Costa Villas Sample ID: Boring 11 (§ 5' Soil Description: Sandy Silt October 3, 2003 Initial Dry Density, pcf 105.1 Initial Moisture, %: 17 Initial Void Ratio: 0.586 Specific Gravity: 2.67 % Change in Height vs Normal Presssure Diagram • Before Saturadon •Rebound •After Saturation •Hydro Consolidation 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 One Dimensional Consolidation ASTM D2435 & D5333 Job Number: 444-3161 Job Name: La Costa Villas Sample ID: Boring 11 @ 10' Soil Description: Silty Sand October 3, 2003 Initial Dry Density, pcf 118.0 Initial Moisture, %: 7 Initial Void Ratio: 0.412 Specific Gravity: 2.67 % Change in Height vs Normal Presssure Diagram •Before Saturation •Rebound • After Saturation • Hydro Consolidation -10 1 ' r 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 \ Gradation ASTM Cl 17 & C136 Project Number: Project Name: 444-3161 La Costa Villas Sample ID: Bulk 1 @ 15-20' Sieve Sieve Percent Size, in Size, mm Passing 1" 25.4 100 3/4" 19.1 100 1/2" 12.7 100 3/8" . 9.53 100 #4 4.75 100 #8 2.36 100 #16 1.18 100 #30 0.60 100 #50 0.30 97 #100 0.15 84 #200 0.074 58 Gradation ASTMC117&C136 Project Number: Project Name: Sample ID: 444-3161 La Costa VUlas Bulk 3 @ 25-30' Sieve Sieve Percent Size, in Size, mm Passing 1" 25.4 100 3/4" 19.1 100 1/2" 12.7 100 3/8" 9.53 100 #4 4.75 100 #8 2.36 100 #16 1.18 100 #30 0.60 100 #50 0.30 100 #100 0.15 48 #200 0.074 9 100 90 80 70 CJO 60 _c Cfl cfl CCj 50 40 30 20 10 0 • » » 100.0 10.0 i.o 0.1 Sieve Size, mm 0.0 0.0 \ Gradation ASTMC117&C136 Project Number: Project Name: 444-3161 La Costa Villas Sample ID: Bulkl @ 1-5' Sieve Sieve Percent Size, in Size, mm Passing 1" 25.4 100 3/4" 19.1 100 1/2" 12.7 100 3/8" 9.53 100 #4 4.75 97 #8 2.36 96 #16 1.18 . 93 #30 0.60 88 #50 0.30 78 #100 0.15 63 #200 0.074 48 \ Project Number: Project Name: Sample ID: 444-3161 La Costa Villas Boring 1 @5' Gradation ASTM Cl 17 (fe C136 Sieve Sieve Percent Size, in Size, mm Passing 1" 25.4 100 3/4" 19.1 100 1/2" 12.7 100 3/8" 9.53 100 #4 4.75 98 #8 2.36 93 #16 1.18 86 #30 0.60 75 #50 0.30 54 #100 0.15 31 #200 0.074 22 100.0 100 -| r4-> • < 1- 90 - 80 -OV/ 70 - OO Uv c Cfl ^2 ^0 - DH NP 40 - 30 - 90 - 10 -1 \J 0 -1 10.0 1.0 0.1 Sieve Size, mm 0.0 0.0 \ Expansion Index ASTM D 4829/UBC 29-2 Job Number: Job Name: Lab ID: Sample ID: Soil Description: 444-3161 La Costa Villas Date: Tech: 10/3/03 Jake Bulk 1 (§ 0-5' Sandy Silt with Traces of Clay Wt of SoU-ming: 595.0 Weight of Ring: 179.0 Wt of Wet SoU: 416.0 Percent Moisture: 8% Wet Density, pcf: 126.0 Dry Denstiy, pcf 116.7 % Saturation: 48.7 Expansion Rack # Date/Time 10/7/03 11:50 a.m. Initial Reading 0.500 Final Reading 0.581 Expansion Index (Final - Initial) X 1000 81 El \ Sladden Engineering Revised 12/10/02 Expansion Index ASTM D 4829/UBC 29-2 Job Number: Job Name: Lab ID: Sample ID: Soil Description: 444-3161 La Costa Villas Bulk 3 @ 25-30' Sand Date: Tech: 10/3/03 Jake Wt ofSoil + Ring: 620.0 Weight of Ring: 179.0 Wt of Wet SoU: 441.0 Percent Moisture: 6% Wet Density, pcf 133.6 Dry Denstiy, pcf 126.1 % Saturation: 48.1 Expansion Rack # Date/Time 10/6/03 8:00 a.m. Initial Reading 0.500 Final Reading 0.501 Expansion Index (Final - Initial) X 1000 EI \ Sladden Engineerin? Revised 12/10/02 Job Number: Job Name: Lab ID: Sample ID: Soil Descripfion: Expansion Index ASTM D 4829/LJBC 29-2 444-3161 La Costa Villas Date: 10/3/03 Tech: Jake Bulk 7 (al 0-5' Silty Sand with Traces of Clay WtofSoil + Ring: 565.0 Weight of Ring: 179.0 Wt of Wet SoU: 386.0 Percent Moisture: 11% Wet Density, pcf 117.0 Dry Denstiy, pcf 105.4 % Saturation: 49.6 Expansion Rack # Date/Time 10/9/03 7:30 a.m. Initial Reading 0.500 Final Reading 0.542 Expansion Index (Final - Initial) X 1000 42 E! \ Sladden Engineering Revised 12/10/02 ANAHEIM TEST LABORATORY 3008 S. ORANGE AVENUE SANTA ANA. CALIFORNIA 92707 PHONE (714) 549-7267 Ta SLADDEN ENGINEERING: 6 78 2 STANTON AVE, SUITE A BUENA PARK, CA. 90621 ATTN; BRETT/DAVE PROJECT: #444-3161 ANALYTICAL REPORT CORROSION SETIIES SUMMARY OF DATA DATt: 9/22/03 P.O. No. Chain of Custody Shipper No. Loo. No. A-38 IS 1-2 Speciflcation: MotsriQl: SOIL pH SOLUBLE SULFATES SOLUBLE CHLORIDES MIN. RESISTIVITY per CA, 417 per CA. 422 per CA. 643 ppm ppm ohm-cm #1 B-7 § 1'-5' 6.5 774 #2 B-1 @ 15'-20' 6.6 1,832 304 364 600 max 600 max \ APPENDIX C 1997 UBC Seismic Design Criteria \ 1997 UNIFORM BUILDING CODE SEISMIC DESIGN INFORMATION The Intemational Conference of Building Officials 1997 Uniform Building Code contains substantial revisions and additions to the earthquake engineering section in Chapter 16. Concepts contained in the 1997 code that will be relevant to construction of the proposed structures are summarized below. Ground shaking is expected to be the primary hazard most likely to affect the site, based upon proximity to significant faults capable of generating large earthquakes. Major fault zones considered to be most likely to create strong ground shaking at the site are listed below. Fault Zone Approximate Distance From Site Fault Type (1997 UBC) Newport - Inglewood 16.8 km B Rose Canyon Fault 8.8 km B Based on our field observations and understanding of local geologic conditions, the soil proflle type judged applicable to this site is SD, generally described as stiff or dense soil. The site is located within UBC Seismic Zone 4. The following table presents additional coefficients and factors relevant to seismic mitigation for design is accordance with the 1997 code. Near-Source Near-Source Seismic Seismic Seismic Acceleration Velocity Coefficient Coefficient Source Factor, N^ Factor, Ny Ca Cv Newport 1.0 1.0 0.44 Na 0.64 Nv Inglewood Rose Canyon Fault 1.0 1.05 0.44 Na 0.64 Nv - * EQFAULT •* y Version 3 . CG * *• DETERMINISTIC ESTIMATION OF PEAK ACCELERATION FROM DIGITIZED FAULTS JOB NUMBER: 544-2063 DATE: 06-23-2002 JOB NAME: Costa Del Mar Road / Carlsbad CALCULATION N-AME: Test Run Analysis FAULT-DATA-FILE NAME: CDMGFLTE.DAT SITE COORDINATES: SITE LATITUDE: 33.0889 SITE LONGITUDE: 117.2678 SEARCH RADIUS: 100 mi ATTENUATION RELATION: 5) Boore et al. (1997) Horiz. - SOIL (310) UNCERTAINTY (M=Median, S=Sigma): M Number of Sigmas: 0.0 DISTANCE MEASURE: cd_2drp SCOND: 0 Basement Depth: 5.00 km Campbell SSR: Campbell SHR: COMPUTE PEAK HORIZONTAL ACCELERATION FAULT-DATA FILE USED: CDMGFLTE.DAT MINIMUM DEPTH VALUE (km): 0.0 , . \ EQF.^.ULT SUMMARY DETERMINISTIC SITE PARAMETERS Page 1 ESTIMATED MAX. EARTHQUAKE EVENT APPROXIMATE ABBREVIATED DISTANCE MAXIMUM 1 PEAK EST. SITE FAULT NAME mi (km) EARTHQUAKE ! SITE INTENSITY MAG . (Mw) 1 ACCEL, g MOD.MERC. ================================ ===== === ==== == ===== ===== 1 ===== ===== ========= ROSE CANYON 5. 5 ( 8. 8) 6. 9 1 0 • 332 IX NEWPORT-INGLEWOOD (Offshore) 10. 4 ( 16. 8) 6. 9 1 0. 220 IX CORONADO BANK 20 . 6 ( 33. 2) 7 1 0. 173 VIII ELSINORE-TEMECULA 24 . 8 ( 39. 9) 6 . 1 0. 110 VII ELSINORE-JULIAN 24 . 8 ( 39. 9) 7 . 1 1 0. 129 VIII ELSINORE-GLEN IVY 38 . 5 ( 62. 1) 6. 8 1 0. 078 VII EARTHQUAKE VALLEY 40 . 3 { 64 . 8) 6 . 5 1 0. 065 VI PALOS VERDES 41 . 1 ( 65. 1) 7 1 1 0. 087 VII SAN JACINTO-ANZA 47 . 7 ( 76. 7) 7 . 2 1 0. 082 VII SAN JACINTO-SAN JACINTO VALLEY 49. 3 ( 79. 4) 6. 9 1 0. 068 VI SAN JACINTO-COYOTE CREEK 50 . 8 ( 81. 3) 6. 8 1 0. 063 VI NEWPORT-INGLEWOOD (L.A.Basin) 52 . 2 ( 84 . 0) 6. 9 1 0. 065 VI CHINO-CENTRAL AVE. (Elsinore) 52. 8 ( 84 . 9) 6. 7 1 0. 071 VI . ELSINORE-COYOTE MOUNTAIN 53. 1 ( 85. 5) 6 . o 1 0. 061 VI WHITTIER 57 . 0 ( 91. 8) 6 . 8 1 0. 058 VI COMPTON THRUST 61. 8 ( 99. 5 ) 6. 8 1 0. 066 VI SAN JACINTO - BORREGO 62 . 6 ( 100. 8) 6. 6 1 0. 048 1 VI SAN JACINTO-SAN BERNARDINO 64 . 1 ( 103. 2) 6. 7 1 0. 050 1 VI ELYSIAN . PARK THRUST 64 . 5 ( 103. 8) 6. 7 1 0. 061 1 VI SAN ANDREAS - San Bernardino 67 . 4 ( 108 . 4) 7 . 3 1 0. 066 1 VI SAN ANDREAS - Southern 67 . 4 ( 108 . 4) 7 . 4 1 0 070 1 VI SAN JOSE 73. 8 ( 118 . 8) 6. 5 1 0 049 1 VI SAN ANDREAS - Coachella 73. 8 ( 118 . 8) 7 1 . 1 • 0 055 1 VI PINTO MOUNTAIN 74 . 0 ( 119. 1) 7 0 1 0 052 1 VI CUCAMONGA 76. 2 ( 122 . 7) 7 0 1 0 062 1 VI SIERRA MADRE 76. 5 ( 123 . 1) 7 0 1 0 062 1 VI SUPERSTITION MTN. (San Jacinto) 78 . 2 ( 125. 8) 6 6 1 0 041 ! V BURNT MTN. 78 . 5 ( 126. 3) 1 6 4 1 0 037 1 V NORTH FRONTAL FAULT ZONE (West) 79, 5 ( 128 . 0) 1 7 0 1 0 060 1 VI EUREKA PEAK 81. 2 ( 130. 7) 1 6 4 1 0 036 1 V ELMORE RANCH 81. 9 ( 131. 8) 1 6 6 1 0 039 1 V CLEGHORN 81. 9 ( 131. 8) 1 6 5 1 0 037 1 V NORTH FRONTAL FAULT ZONE (East) 82 7 ; 133. i) 1 6 7 1 0 050 1 VI SUPERSTITION HILLS (San Jacinto) 83 0 ( 133 5) 1 6 6 1 0 039 1 V LAGUNA SALADA 84 1 ( 135 3) 1 7 0 1 0 048 1 VI SAN ANDREAS - 1857 Rupture 85 7 ( 138 0) 1 7 8 1 0 071 1 VI SAN ANDREAS - Mojave 1 85 7 { 138 0) 1 7 1 1 0 049 1 VI RAYMOND 1 85 9 { 13S 2) i 5 5 1 0 044 1 VI CLAMSHELL-S.AWPIT 1., 8 5 1 ( 138 5) 1 6 5 1 0 04 4 1 VI VERDUGO 1* 8 8 4 { 142 \ i 5 7 1 0 .047 1 VI \ DETERMINISTIC S PA.RAMETERS Page 2 1 1 ESTIMATED MAX. EARTHQUAKE EVENT 1 APPROX I l-'ATE ABBREVIATED | DISTANCE 1 MAJ<IMUM 1 PEAK 1 EST . SITE FAULT NAME | mi (km) 1 EARTHQUAKE 1 SITE 1 INTENSITY 1 1 MAG.(Mw) 1 ACCEL. g 1 MOD .MERC. LANDERS 1 89 . 1( 143. 4) 1 7.3 1 0.053 VI HOLLYWOOD 1 90.4 ( 1 45. 5) 1 6.4 1 0.040 V HELENDALE - S. LOCKHARDT - 1 91.5 { 147 . 3) 1 7.1 1 0.047 VI BRAWLEY SEISMIC ZONE | 92.1( 148. 2) 1 6.4 1 0.032 V LENWOOD-LOCKHART-OLD WOMAN SPRGS! 94.8 ( 152 . 5) 1 7.3 1 0.051 VI SANTA MONICA 1 95.2( 153. 2) 1 6.6 1 0.043 VI EMERSON So. - COPPER MTN. | 96.8( 155. 8) 1 6.9 1 0,040 V JOHNSON VALLEY (Northern) 1 97.3( 156. 6) 1 6.7 1 0.036 V MALIBU COAST 1 97.9( 157. 6) 1 6.7 1 0.044 VI IMPERIAL 1 99.2( 159. 6) 1 7.0 1 0.042 1 VI * * * + + * -END OF SEARCH- 50 FAULTS FOUND WITHIN THE SPECIFIED SEA RCH RADIUS. THE ROSE CANYON FAULT IS CLOSEST TO THE'SITE. IT IS ABOUT .5.5 MILES (8.8 km) AWAY. LARGEST MAXIMUM-EARTHQUAKE SITE ACCELERATION: 0.3317 g 1100 1000 CALIFORNIA FAULT MAP Costa Del Mar Road / Carlsbad 400 -300 -200 -100 0 100 200 300 400 500 600 \ STRIKE-SLIP FAULTS 5) Boore et al. (1997) Horiz. - SOIL (310) c q '+-> 03 0) CD O O < M=5 M=6 M=7 M=8 1 -= 01 -= ,001 10 100 Distance \a6\s\] (km) DIP-SLIP FAULTS 5) Boore et al. (1997) Horiz. - SOIL (310) M=5 M=6 M=7 M=8 c q '4—' 03 L_ 0) CD O O < .1 -= ,01 ,001 10 100 Distance \a6\si] (km) BLEND-THRUST FAULTS 5) Boore et al. (1997) Horiz. - SOIL (310) c _o "-t-J 03 Q) (D O O < M=5 M=6 M=7 M=8 1 -i:' 01 -= 001 10 100 Distance \a6\si] (km) MAXIMUM EARTHQUAKES Costa Del Mar Road / Carlsbad c o 03 s_ 0) CD O O < 1 -- 1 -= 01 ,001 1 10 Distance (mi) 100 EARTHQUAKE MAGNITUDES & DISTANCES Costa Del Mar Road / Carlsbad 1 10 Distance (mi) 100 HUNSAKER ^ASSOCIATES SAN DIECO, INC. PLANNING ENGINEERINC SURVEYING IRVINE LOS ANGELES RIVERSIDE SAN DIECO STORM WATER MANAGEMENT PLAN for LA COSTA RESORT & SPA PHASE II City of Carlsbad, California Prepared for: KSL Development Corporation 2100 Costa Del Mar Road Carlsbad, CA 92009 w.o. 2503-1 July 19, 2005 DAVE HAMMAR LEX WILLIMAN ALISA VIALPANDO RAN SMITM RAY MARTIN 10179 Huennekens St. San Diego, CA 92121 (858) 558-4500 PH (858)558-1414 FX www.HunsakerSD.com lnfo@HunsakerSD.com Hunsaker & Associates San Diego, Inc. R^yfnond L. Martin, R.C.E. Vice President 1/ 71 DE:kc H:«EPORTS\2503\01\SWMP03.doc w.o. 2503-1 7/19/2005 2;49PM La Costa Resort & Spa Phase il Storm Water Management Plan TABLE OF CONTENTS CHAPTER 1 - Executive Summary 1.1 Introduction 1.2 Summary of Pre-Developed Conditions 1.3 Summary of Proposed Development 1.4 Results and Recommendations 1.5 Conclusion CHAPTER 2 - storm Water Criteria 2.1 Regional Water Quality Control Board Criteria 2.2 City of Carlsbad SUSMP Criteria CHAPTER 3 - Identification of Typical Pollutants 3.1 Anticipated Pollutants from Project Site 3.2 Sediment 3.3 Nutrients 3.4 Trash & Debris 3.5 Oxygen-Demanding Substances 3.6 Oil & Grease 3.7 Metals 3.8 Bacteria & Viruses 3.9 Pesticides CHAPTER 4 - Conditions of Concern 4.1 Receiving Watershed Descriptions 4.2 Pollutants of Concern in Receiving Watersheds CHAPTER 5 - Flow-Based BMPs 5.1 Design Criteria 5.2 Grass-Lined Swales 5.3 Pollutant Removal Efficiency Table 5.4 Maintenance Requirements 5.5 Annual Operations and Maintenance Plan & Costs KT: HAREPORTa2503«)1\SWMP02.doc W.0.2352-107 5/ia/200S9:S5AM La Costa Resort & Spa Phase II Storm Water Management Plan CHAPTER 6 - Source Control BMPs 6.1 Landscaping 6.2 Urban Housekeeping 6.3 Automobile Use 6.4 Site Design BMPs CHAPTER 7 - Treatment Control BMP Design (Grassy Swale) 7.1 BMP Location 7.2 Determination of Treatment Flows 7.3 Grassy Swale Sizing CHAPTER 8 - References List of Tables and Figures Chapter 1 - Watershed Map Chapter 2 - Storm Water Requirements Applicability Checklist Chapter 2 - Site Design and Source Control Storm Water BMP Selection Matrix Chapter 3 - Pollutant Category Table Chapter 4 - San Diego Region Hydrologic Divisions Chapter 4 - Combined 1998 and Draft 2002 Section 303(d) Update Chapter 4 - Beneficial Uses of Inland Surface Waters Chapter 4 - Water Quality Objectives Chapter 5 - Pollutant Removal Efficiency Table (Flow-Based BMPs) Chapter 7 - BMP Location Map Chapter 7 - Design Runoff Determination Summary Table Chapter 7 - Swale Design Spreadsheet Attachments BMP Location Map DE:de H:\REPORTS\2503«l1\SWMP02.doc w.a.2S03-1 S/18/2005 9:55 AM La Costa Resort & Spa Phase II Storm Water Management Plan CHAPTER 1 - EXECUTIVE SUMMARY 1.1 - Introduction The La Costa Resort & Spa Phase II site is located north ofthe intersection of El Camino Real and Costa Del Mar Road in the City of Carlsbad, California (see Vicinity Map on this page). The 3.2-acre site is located within the greater La Costa Resort and Spa development. CITY OF OCEANSIDE CITY OF ENCINITAS ViCINITY MAP NOT TO SCALE J ,-PRCpECT QsL^gATION All runoff from the project site will drain south to the existing 36-inch RCP storm drain within El Camino Real, ultimately draining to San Marcos Creek. Runoff from San Marcos Creek eventually discharges into Batiquitos Lagoon. Perthe City of Carlsbad SUSMP, the La Costa Resort & Spa Phase II project is classified as a Priority Project and subject to the City's Permanent Storm Water BMP Requirements. This Storm Water Management Plan (SWMP) has been prepared pursuant to requirements set forth in the City of Carlsbad's "Standard Urban Storm Water Mitigation Plan (SUSMP)." All calculations are consistent with criteria set forth by the Regional Water Quality Control Board's Order No. 2001-01, and the City of Carlsbad SUSMP. This SWMP recommends the location and sizing of site Best Management Practices (BMPs) which include a grass lined swale. See BMP Location Map in this chapter. DE:de H:\REPORT5\2503\01\SWMP02.doc w.a.2S03-1 5/180005 9:55 AM La Costa Resort & Spa Phase II Storm Water Management Plan Furthermore, this report determines anticipated project pollutants, pollutants of concern in the receiving watershed, peak flow mitigation, recommended source control BMPs, and methodology used forthe design of flow-based BMPs. 1.2 - Summarv of Pre-Developed Conditions Currently a mass graded lot, the project is located within the existing La Costa Resort and Spa development, which is being constructed in multiple phases. Site runoff currently flows overland to the receiving curb and gutter located to the west of the proposed site. A 24-inch storm drain, located to the west ofthe site (adjacent to El Camino Real) discharges mnoff from the Phase 1 portion ofthe La Costa Resort and Spa development to a large, natural open space. Flow is then conveyed south via this grassed natural area to the receiving 36-inch RCP located within the proximity ofthe intersection of El Camino Real and Costa Del Mar Road. Per the "Drainage Study for La Costa Resort and Spa Phases I & II" dated May, 2005 by Hunsaker & Associates, peak flow data from the adjacent Phase 1 ofthe La Costa Resort development attributes 63.4 cfs from a developed area of 21.8 acres to this existing 30-inch storm drain. Priorto exiting the existing 30-inch storm drain, runoff from Phase I ofthe La Costa Resort and Spa development is treated via a CDS unit. However, runoff from the proposed La Costa Resort and Spa Phase II site is not treated within this existing unit The Regional Water Quality Control Board has identified San Marcos Creek as part ofthe Carlsbad Hydrologic Unit, San Marcos Hydrologic Area, and the Batiquitos Hydrologic Subarea (basin number 904.51). 1.3 - Summarv of Proposed Development Development ofthe 3.2-acre area will consist of 38 multi-family residences, foot paths, communal open space, onsite parking and underground utilities with a single entrance from the adjacent Estrella Del Mar Road. Peak flow generated by the proposed La Costa Resort & Spa Phase II development will be conveyed to two (2) points of discharge. The western portion of the development will drain via curb and gutter, entering the proposed extension to the existing 30-inch storm drain located to the west of the project site. The eastern portion of the developed site will drain to the receiving curb and gutter within Costa Del Mar Road. It should be noted that all low flows, inclusive of the 85*^^ percentile treatment flow, is contained within the area drain system for the La Costa Resort & Spa Phase II site and is conveyed to the western storm drain system. DE:de H:\REPORTSV2503W1\SVVMP02.doc W.0.2503-1 5/18/2005 10:31 AM CARLSBAD ENQNITAS WATERSHED MAP FOR LA COSTA RESORT & SPA PHASE 2 CITY OF CARLSBAD. CALIFORNIA La Costa Resort & Spa Phase II Storm Water Management Plan 85**^ percentile mnoff from the proposed La Costa Resort & Spa Phase II and the existing Phase 1 portion of the La Costa Resort and Spa via a grass lined BMP prior to discharge to the existing storm drain system within El Camino Real. Based on County of San Diego criteria, runoff coefficient of 0.82 was assumed for the proposed multi-family residential development. 1.4 - Results and Recommendations Table 1 below summarizes rational method 85*^ percentile calculations for the proposed water quality treatment swale for the La Costa Resort & Spa Phase I the attributing La Costa Resort and Spa Phase I development. Table 1 - Developed Conditions 85*^ Percentile Calculations and BMP Drainage Area (acres) Rainfall Intensity (inches/hour) Runoff Coefficient 85'" Pct. Design Flow (cfs) Grassy Swale 23.3* 0.2 0.82 3.8 'Note: Inclusive of the adjoining La Costa Resort and Spa Phase I Rational Method calculations predicted an 85*^ percentile runoff flow of roughly 3.8 cfs for the area discharging to the existing vegetated open space area adjacent to El Camino Real. Calculations show that this existing natural open space has sufficient treatment capacity in order to treat this developed flow (refer to Chapter 7). It should be noted that this natural swale area is a temporary BMP treatment area. Future phases ofthe La Costa Resort and Spa propose to construct a parking lot where this current natural area exists, continuing the storm drain system within this future development and connecting directly to the existing 36-inch storm drain within El Camino Real. This future development will incorporate a proposed flow based treatment unit (CDS or similar approved, flow based treatment unit) prior to entering the existing 36-inch storm drain. The existing CDS treatment unit currently servicing flow from Phase 1 ofthe La Costa Resort and Spa development will remain, providing additional treatment. 1.5 - Conclusion The combination of proposed construction and permanent BMP's will reduce, to the maximum extent practicable, the expected project pollutants and will not adversely impact the beneficial uses ofthe receiving waters. DE:de H:\REPORTS\2503\01\SWMP02.doc w.0. 2503-1 5/18/2005 9:55 AM HUNSAKER & ASSOCIATES lAH micft INC BO0MC SMDki^aim BMP LOCATION EXHIBIT FOR LA COSTA RESORT & SPA PHASE 2 CIPI' OF CARLSBAD, CALIFORNIA SHEET 1 OF 1 Ri\ll51S\tHyd\615>Ha3-BHP.ilwgC EOB5)M<iy-18-20l)5ilOilll La Costa Resort & Spa Phase II Storm Water Management Plan CHAPTER 2 - STORM WATER CRITERIA 2.1 - Regional Water Qualitv Control Board Criteria All mnoff conveyed in the proposed storm drain systems will be treated in compliance with Regional Water Quality Control Board regulations and NPDES criteria priorto discharging to natural watercourses. California Regional Water Quality Control Board Order No. 2001-01, dated February 21, 2001, sets waste discharge requirements for discharges of urban runoff from municipal storm separate drainage systems draining the watersheds of San Diego County. Perthe RWQCB Order, post-development runoff from a site shall not contain pollutant loads which cause or contribute to an exceedance of receiving water quality objectives or which have not been reduced to the maximum extent practicable. Post-construction Best Management Practices (BMPs), which refer to specific stonn water management techniques that are applied to manage construction and post-construction site mnoff and minimize erosion, include source control - aimed at reducing the amount of sediment and other pollutants - and treatment controls that keep soil and other pollutants onsite once they have been loosened by storm water erosion. Post constmction pollutants are a result ofthe urban development ofthe property and the effects of automobile use. Runoff from paved surfaces can contain both sediment (in the form of silt and sand) as well as a variety of pollutants transported by the sediment. Landscape activities by homeowners are an additional source of sediment. All structural BMPs shall be located to infiltrate, filter, or treat the required runoff volume or flow (based on the 85"^ percentile rainfall) priorto its discharge to any receiving watercourse supporting beneficial uses. 2.2 - Citv of Carlsbad SUSMP Criteria Per the City of Carlsbad SUSMP, the La Costa Resort & Spa Phase II project is classified as a Priority Project and subject to the City's Permanent Storm Water BMP Requirements. These requirements required the preparation ofthis Storm Water Management Plan. The Storm Water Applicability Checklist, which must be included along with Grading Plan applications, is included on the following page. DE:de H:\REPORTS\2503«)HSV™P02.doc w.o. 2503-1 S/18/2005 9:55 AM Storm Water Standards 4/03/03 LyirRESGLTRQES & REF_ERENCES _r ^ _ =^_¥£^ "1 _ = - _ , - ~_- APPENDIXA STORM WATER REQUIREMENTS APPLICABILITY CHECKLIST Complete Sections 1 and 2 of the following checklist to determine your project's permanent and construction storm water best management practices requirements. This form must be completed and submitted with your permit application. Section 1. Permanent Storm Water BMP Requirements: If any answers to Part A are answered "Yes," your project is subject to the "Priority Project Permanent Storm Water BMP Requirements," and "Standard Permanent Stomri Water BMP Requirements" in Section III, "Permanent Storm Water BMP Selection Procedure" in the Stom? Water Standards manual. If all answers to Part A are "No," and any answers to Part B are "Yes," your project is only subject to the "Standard Permanent Storm Water BMP Requirements". If every question in Part A and B is answered "No," your project is exempt from permanent storm water requirements. Part A: Determine Priority Project Permanent Storm Water BMP Requirements Does the project meet the definition of one or more of the priority project categories?* Yes No 1. Detached residential development of 10 or more units 2. Attached residential development of 10 or more units 3. Commercial development greater than 100,000 square feet 4. Automotive repair shop 5. Restaurant 6. Steep hillside development greater than 5,000 square feet y 7. Project discharging to receiving waters within Environmentally Sensitive Areas 8. Parking lots greater than or equal to 5,000 ft'' or with at least 15 parking spaces, and potentially exposed to urban runoff 9. Streets, roads, highways, and freeways which would create a new paved surface that is 5,000 square feet or greater * Refer to the definitions section in the Stomi Water Standards tor expanded definitions ofthe priority project categories. Limited Exclusion: Trenching and resurfacing wori< associated with utility projects are not considered priority projects. Parking lots, buildings and other structures associated with utility projects are priority projects if one or more of the criteria in Part A is met. If all answers to Part A are "No", continue to Part B. 30 storm Water Standards 4/03/03 Does the project propose: Yes No 1. New impervious areas, such as rooftops, roads, parking lots, driveways, paths and sidewalks? 2. New pervious landscape areas and inigation systems? 3. Permanent structures within 100 feet of any natural water body? 4. Trash storage areas? 5. Liquid or solid material loading and unloading areas? 6. Vehicle or equipment fueling, washing, or maintenance areas? 7. Require a General NPDES Pennit for Storm Water Discharges Associated with Industrial Activities (Except construction)?* 8. Commercial or industrial waste handling or storage, excluding typical office or household waste? 9. Any grading or ground disturbance during construction? 10. Any new storm drains, or alteration to existing storm drains? *To find out if your project is required to obtain an individual General NPDES Pennit for Stonn Water Discharges Associated with Industrial Activities, visit the State Water Resources Control Board web site at, www.swrcb.ca.gov/stonnwtr/industrial.html Section 2. Construction Storm Water BMP Requirements: If the answer to question 1 of Part C is answered "Yes," your project is subject to Section IV, "Construction Storm Water BMP Performance Standards," and must prepare a Storm Water Pollution Prevention Plan (SWPPP). If the answer to question 1 is "No," but the answer to any of the remaining questions is "Yes," your project is subject to Section IV, "Construction Storm Water BMP Performance Standards," and must prepare a Water Pollution Control Plan (WPCP). If every question in Part C is answered "No," your project is exempt from any construction storm water BMP requirements. If any of the answers to the questions in Part C are "Yes," compiete the construction site prioritization in Part D, below. Part C: Determine Construction Phase Storm Water Requirements Would the project meet any ofthese criteria during construction? Yes No 1. Is the project subject to California's statewide General NPDES Permit for Storm Water Discharges Associated With Construction Activities? / 2. Does the project propose grading or soil disturbance? 3. Would storm water or urban runoff have the potential to contact any portion of the construction area, including washing and staging areas? 4. Would the project use any construction materials that could negatively affect water quality if discharged from the site (such as, paints, solvents, concrete, and stucco)? / 31 Storm Water Standards 4/03/03 Part D: Determine Construction Site Priority ?'^^°D?fn^® ^'•'^ Municipal Permit, each constmction site with construction storm water BMP requirements must be designated with a priority: high, medium or low the SW^PP oJ W^^^^^^ InTr'fh ""'^ • °" P'^"^' '"^'"ded in-the SWPPP or WPCP. Indicate the project's pnority in one of the check boxes using the criteria below, and existing and surrounding conditions of the project the tvoe of activities necessary to complete the constmction and any other' extenuating ^nSilir h"^^'*^^K '^^y P°s^ 3 .threat to water quality. The City'reserves the righ tto adjust the pnonty of the projects both before and during constmction [Note- The constmction priority does NOT change constmction BMP requirements that applv to projects; all constmction BMP requirements must be identified on a case-by-case basis. The cons mction pnority does affect the frequency of inspections that will be requirements^] "^^'^ "^^^^"^ °" constmction BMP •f A) High Priority 1) Projects where the site is 50 acres or more and grading will occur during the rainy season 2) Projects 5 acres or more. 3) Projects 5 acres or more within or directly adjacent to or discharging directly to a coastal lagoon or other receiving water within an environmentally sensitive area Projects, active or inactive, adjacent or tributary to sensitive water bodies Q B) Medium Priority 1) Capital Improvement Projects where grading occurs, however a Storm Water Pollution Prevention Plan (SWPPP) is not required under the State General Construction Permit (i.e., water and sewer replacement projects, intersection and street re-alignments, widening, comfort stations, etc.) 2) Pennit projects in the public right-of-way where grading occurs, such as installation of sidewalk, substantial retaining walls, curb and gutter for an entire street frontage, etc. , however SWPPPs are not required. 3) Permit projects on private property where grading permits are required however, Notice Of Intents (NOIs) and SWPPPs are not required. • C) Low Priority 1) Capital Projects where minimal to no grading occurs, such as signal light and loop installations, street light installations, etc. 2) Permit projects in the public right-of-way where minimal to no grading occurs such as pedestrian ramps, driveway additions, small retaining walls, etc. 3) Permit projects on private property where grading permits are not required, such as small retaining walls, single-family homes, small tenant improvements, etc. 32 Table 2. Site Design and Souree Control Stonn Water BMP Sefection Matrix Priority Project Category Site Design BMP?' Sotirce Control BMPsF> Requirements Applicable to Individual Priority Project Categories'^' raways & alnlenance Bays ihicle Wash Areas islng Areas ih Areas a> c a. Ivate Roads jsldentlal DrIv jest Parking ]ck Areas alnlenance Bays ihicle Wash Areas jidoor Procea lulpment Wat irking Areas )adways lellng Areas llslde LandsGi a. ceo Q O LU Q. oc U. I • d xi (3 •6 ffl d) f Detached Residential Development R R R R R Attached Residential Deveiopment R R R Commercial Development >100,000 ft* R R R R R R Automotive Repair Shop R R R R R R R Restaurants R R R R Hillside Development >5,000 fl* R R R R Parking Lots R R Streets, Highways & Freeways R R R R = Required; select BMPs as required from the applicable steps In Section Vl.2.a & b, or equivalent as identified in Appendix A. (1) Refer to- Section V1.2.a. (2) Refer to Sedion V1.2.b. (3) Priority projeot categories must apply specific storm water BMP requirements, where appiicable. Projects are subject to the requirements of all priority project categories that apply. (4) Applies if the paved area totals >5,000 square feet or with >15 parking spaces and Is potentially exposed to urban runoff. Page 18 of 51 FINAL MODEL SUSMP Joinlly Developed by SanDiego Co-Permittees 2/14/02, Approved by SDRWQCB 6/12/02 La Costa Resort & Spa Phase II Storm Water Management Plan CHAPTER 3 - IDENTIFICATION OF TYPICAL POLLUTANTS 3.1 - Anticipated Pollutants from Proiect Site The following table details typical anticipated and potential pollutants generated by various land use types. The La Costa Resort & Spa Phase II development will consist of attached multi-family residences. The existing La Costa Resort and Spa Phase I development consists of attached multi-family and commercial development. Thus, the Attached Residential Development & Commercial Development categories have been highlighted to clearly illustrate which general pollutant categories are anticipated from the project area. General Pollutant Categories Priority Project Categories (0 C « E 0) 10 c 0) X S (0 •D C « E O O 00 10 10 c = I o> 5 >> E a ® O Q 10 .o Ui 0 (0 n £ o 96 o9 k ffi « w n .h CQ > «o •o o 10 o Q. Detached Residential Development Automotive Repair Shops X X X Restaurants X X X X Hillside Development >5,000 ft^ X X X X X X Parking Lots p(i) p(1) X X pd) X pd) Streets, Highways & Freeways X pd) X X(4) X p(5) X Retail Gas Outlets X X(4) X X X = anticipated P = potential (1) A potential pollutant if landscaping exists on-site. (2) A potential pollutant if the project inciudes uncovered parking areas. (3) A potential pollutant if iand use involves food or animal waste products. (4) Including petroleum hydrocarbons. (5) Including solvents. D&de H:\REPORTS\2503\01\SWMP02.doc w.o. 2503-1 S/1BQ005 9:55 AM La Costa Resort & Spa Phase II Storm Water Management Plan 3.2 - Sediment Soils or other surface materials eroded and then transported or deposited by the action of wind, water, ice, or gravity. Sediments can increase turbidity, clog fish gills, reduce spawning habitat, smother bottom dwelling organisms, and suppress aquatic vegetative growth. 3.3 - Nutrients Inorganic substances, such as nitrogen and phosphorous, that commonly exist in the form of mineral salts that are either dissolved or suspended in water. Primary sources of nutrients in urban mnoff are fertilizers and eroded soils. Excessive discharge of nutrients to water bodies and streams can cause excessive aquatic algae and plant growth. Such excessive production, referred to as cultural eutrophication, may lead to excessive decay of organic matter in the water body, loss of oxygen in the water, release of toxins in sediment, and the eventual death of aquatic organisms. 3.4 - Trash & Debris Examples include paper, plastic, leaves, grass cuttings, and food waste, which may have a significant impact on the recreational value of a water body and aquatic habitat. Excess organic matter can create a high biochemical oxygen demand in a stream and thereby lower its water quality. In areas where stagnant water is present, the presence of excess organic matter can promote septic conditions resulting In the growth of undesirable organisms and the release of odorous and hazardous compounds such as hydrogen sulfide. 3.5 - Oxvqen-Demandinq Substances Biodegradable organic material as well as chemicals that react with dissolved oxygen in water to form other compounds. Compounds such as ammonia and hydrogen sulfide are examples of oxygen-demanding compounds. The oxygen demand of a substance can lead to depletion of dissolved oxygen in a water body and possibly the development of septic conditions. 3.6 - Oil & Grease Characterized as high high-molecular weight organic compounds. Primary sources of oil and grease are petroleum hydrocarbon products, motor products from leaking vehicles, oils, waxes, and high-molecular weight fatty acids. Elevated oil and grease content can decrease the aesthetic value of the water body, as well as the water quality. DE:Cle H:\REPORTS\2503\01\SVVMP02.<)OC w.0.2503-1 5/1S/2005 9:55 AM La Costa Resort & Spa Phase 11 Storm Water Management Plan 3.7 - Metals Metals are raw material components in non-metal products such as fuels, adhesives, paints and other coatings. Primary sources of metal pollution in storm water are typically commercially available metals and metal products. Metals of concern include cadmium, chromium, copper, lead, mercury and zinc. Lead and chromium have been used as corrosion inhibitors in primer coatings and cooler tower systems. At low concentrations naturally occurring in soil, metals are not toxic. However, at higher concentrations, certain metals can be toxic to aquatic life. Humans can be impacted from contaminated groundwater resources, and bioaccumulation of metals in fish and shellfish. Environmental concerns, regarding the potential for release of metals to the environment, have already led to restricted metal usage in certain applications. 3.8 - Bacteria & Viruses Bacteria and viruses are ubiquitous micro-organisms that thrive under certain environmental conditions. Their proliferation is typically caused by the transport of animal or human fecal wastes from the watershed. Water, containing excessive bacteria and viruses can alter the aquatic habitat and create a harmful environment for humans and aquatic life. Also, the decomposition of excess organic waste causes increased growth of undesirable organisms in the water. 3.9 - Pesticides Pesticides (including herbicides) are chemical compounds commonly used to control nuisance growth or prevalence of organisms. Excessive application of a pesticide may result in runoff containing toxic levels of its active component. DE:lle H:\REPORTS\2503\01\5VVMP02.doc wj>. 2503-1 5/18/2005 9:55 AM La Costa Resort & Spa Phase II Storm Water Management Plan CHAPTER 4 - CONDITIONS OF CONCERN 4.1 - Receiving Watershed Descriptions As shown in the watershed map on the following page, the pre-developed La Costa Resort & Spa Phase II site drains to San Marcos Creek which eventually discharges to the Batiquitos Lagoon within the San Marcos Creek watershed. Development ofthe site will not cause any diversion to or from the existing watershed to the stomri drain system. The Regional Water Quality Control Board has identified San Marcos Creek as part ofthe Carlsbad Hydrologic Unit, San Marcos Creek Watershed, and the Batiquitos Hydrologic Subarea (basin number 904.51). 4.2 - Pollutants of Concern in Receiving Watersheds San Marcos Creek and Batiquitos Lagoon are not listed on the EPA's 303(d) List of endangered waterways (included in this Chapter). Per the "Water Quality Plan for the San Diego Basin", the beneficial uses forthe Batiquitos Lagoon and San Marcos Creek includes agricultural supply, contact water recreation, non-contact recreation, warm freshwater habitat, and wildlife habitat. Table 3-2 from the "Water Quality Plan for the San Diego Basin" (included at the end of this Chapter) lists water quality objectives for a variety of potential pollutants required to sustain the beneficial uses ofthe San Marcos hydrologic area. DE:(le H:\REPORTS\2503V01\SWMP02.(loc W.D. 2503-1 S/18/2005 9:55 AM CARLSBAD WATEHSHED MAP FOH LA COSTA RESORT & SPA PHASE 2 cm/ OF CARLSBAO, CALIFOHNW Table 2-2. BENEFICIAL USES OF INLAND SURFACE WATERS BENEFICIAL U SE 1,2 Inland Surface Waters Hydrologic Unit Basin Number M U N A G R 1 N D P R 0 C G W R F R S H P O W R E C 1 R E C 2 B 1 0 L W A R M C 0 L D W 1 L D R A R E S P W N San Dlego Courity Coaistal Streamis- continued Buena Vlsta Lagoon 4.21 See Coastal Waters- Table 2-3 Buena Vista Creek 4.22 + • • • • • Buena Vista Creek 4.21 -1-• • • • • • • Agua Hedionda 4.31 See Coastal Waters- Table 2-3 Agua Hedionda Creek 4.32 • • • • • • • Buena Creek 4.32 • • • • • • • Agua Hedionda Creek 4.31 • • • • • • • Letterbox canyon 4.31 • • • • • • • Canyon de las Encinas 4.40 + 0 • • • San Marcos Creek Watershed Batiquitos Lagoon 4.51 See Coastal Waters-Table 2-3 San Marcos Creek 4.52 + • • • • unnamed intermittent streams 4.53 + • • • • • San Marcos Creek Watershed San Marcos Creek 4.51 • • • • Encinitas Creek 4.51 + • • • • • • Existing Beneficial Use O Potential Beneficial Use + Excepted From MUN (See Text) 1 Waterbodies are listed multiple times if they cross hydrologic area or sub area boundaries. Beneficial use designations appiy to all tributaries to the indicated waterbody, if not listed separately. Tabla 2-2 BENEFICIAL USES March 12, 1997 2-27 Table 2-3. BENEFICIAL USES OF COASTAL WATERS BENEFICIAL USE Coastal Waters Hydrologic Unit Basin 1 N N A R E R E C .0 B 1 UJ CO w 1 R A M A A Q M 1 S P W A S H Hydrologic Unit Basin D V c C M 0 T L R R U G w R E Number V 1 2 M L D E A R N M L L Pacific Ocean • • • • • • • • • • • • • Dana Point Harbor • • • • • • • • • • Del Mar Boat Basin • • • • • • • • • • • Mission Bay • • • • • • • • • • • Oceanside Harbor • • • • • • • • • • • San Diego Bay ' • • • • • • • • • • Coastal Lagoons ' Tijuana River Estuary ii.ii • • • • • • • • • • Mouth of San Diego River 7.11 • • • • • • • • • • 2 Los Penasquitos Lagoon 6.10 • • • • • • • • • • San Dieguito Lagoon 5.11 • • • • • • • • • Batiquitos. Lagoon 4.51 • • • • • • • • • San Elijo Lagoon 5.61 • • • • • • • • • Aqua Hedionda Lagoon 4.31 • • • • • • • • • • ' Includes the tidal prisms of the Otay and Sweetwater Rivers. 2 Fishing from shore or boat permitted, but other water contact recreational (REC-1) uses are prohibited. # Existing Beneficial Use Table 2-3 BENERCIAL USES 2-47 March 12, 1997 Table 3-2. WATER QUALITY OBJECTIVES Concentrations not to be exceeded more than 10% of tha time during any one ona year pariod. Const tiuent (mg/L or as noted) Inland Surface Waters Hydrologic Unit Basin Number TDS Cl SO, %Na N&P Fe Mn MBAS B ODOR Turb NTU Color Units SAN LUIS REY HYDROLOGIC UNIT 903.00 Lower San Luis HA 3.10 500 250 250 60 a 0.3 0.05 0.5 0.75 none 20 20 1.0 Monserat HA 3.20 500 250 250 60 a 0.3 0.05 0.5 0.75 none 20 20 1.0 Warner Valley HA 3.30 500 250 250 60 a 0.3 0.05 0.5 0.75 none 20 20 1.0 CARLSBAD HYDROLOGIC UNIT 904.00 Loma Alta HA 4.10 ---------none 20 20 1.0 Buena Vista Creek HA 4.20 500 250 250 60 a 0.3 0.06 0.5 0.75 none 20 20 1.0 Agua Hedionda HA 4.30 500 250 250 60 a 0.3 0.05 0.5 0.75 none 20 20 1.0 Encinas HA 4.40 ---------nona 20 20 1.0 San Marcos HA 4.50 500 250 250 60 a 0.3 0.05 0.5 0.75 none 20 20 1.0 Escondido Creek HA 4.60 500 250 250 60 a 0.3 0.05 0.5 0.75 none 20 20 1.0 SAN DIEQUITO HYDROLOGIC UNIT 906.00 Solana Beach HA 5.10 500 250 250 60 a 0.3 0.05 0.5 0.76 none 20 20 1.0 Hodges HA 5.20 500 250 250 60 a 0.3 0.05 0.5 0.75 none 20 20 1.0 San Pasqual HA 5.30 500 250 250 60 a 0.3 0.05 0.5 0.75 none 20 20 1.0 Santa Maria Valley HA 5.40 500 250 250 60 a 0.3 0.06 0.5 0.75 none 20 20 1.0 Santa Ysabel HA 5.50 500 250 250 60 a 0.3 0.05 0.5 0.75 nona 20 20 1.0 PENASQUITOS HYDROLOGIC UNIT 906.00 Miramar Reservoir HA 6.10 500 250 250 60 a 0.3 0.05 0.6 0.75 none 20 20 1.0 Poway HA 6.20 500 250 250 60 a 0.3 0.05 0.5 0.75 none 20 20 1.0 HA - Hydrologic Araa HSA - Hydrologic Sub Area (Lower casa letters indicate endnotes following the table.) Table 3-2 WATER QUALITY OBJECTIVES Page 3-23 Saptamber 8. 1994 2002 CWA SECTION 303(d) LIST OF WATER QUALITY LIIMITED SEGMENT SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD R Agua Hedionda Creek 90431000 mmimmimmmmmmmmm^ E Agua Hedionda Lagoon R Aliso Creek mmmmKmmmKmmammmmmmmxBammmsm 9 E Aliso Creek (mouth) 9 E Buena Vista Lagoon 90431000 90113000 90113000 90421000 Total Dissolved Solids Low Urban Runofl/Storm Sewers Unknown Nonpoint Source Unknown point source Bacteria Indicators Sedimentation/Siltation Nonpoint/Point Source Nonpoint/Point Source Low Low Bacteria Indicators Urban Runoff/Storm Sewers Unknown point source Nonpoint/Point Source Phosphorus ImpairmenI locaied at lower 4 miles. Urban Runofl/Storm Sewers Unknown Nonpoint Source Unknown point source Toxicity Urban Runofl/Storm Sewers Unknown Nonpoint Source Unknown point source Medium Low Low Bacteria Indicators Medium Nonpoint/Point Source Bacteria Indicators Low Nonpoint/Point Source Nutrients Low Eslimaied size of ImpairmenI is 150 acres located in upper portion of lagoon. Nonpoint/Point Source Sedimentation/Siltation Medium Nonpoint/Point Source 7 Miles 6.8 Acres 6.8 Acres 19 Miles 19 Miles 19 Miles 0.29 Acres 202 Acres 202 Acres 202 Acres Page 1 of 16 2002 CWA SECTION 303(d) LIST OF WATER QUALITY LIMITED SEGMENT SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD 9 R Sandia Creek 9 E Santa Margarita Lagoon 9 R Santa Margarita River (Upper) 9 R Segunda Deshecha Creek 90222000 90211000 90222000 90130000 Total Dissolved Solids Low 19 Miles Total Dissolved Solids Eutrophic Phosphorus Phosphorus Turbidity Page 13 of 16 Industrial Point Sources Agriculture-storm runoff Urban Runofl/Storm Sewers Surface Mining Flow Regulation/Modification Natural Sources Golfcourse activities Unknown Nonpoint Source Unknown point source Low Urban Runofl/Storm Sewers Flow Regulation/Modification Natural Sources Unknown Nonpoint Source Unknown point source mmmmummmmiimumimaimmmmm^ smmmamm Low Nonpoint/Point Source L,ow Urban RunofC'Storm Sewers Unknown Nonpoint Source Unknown point source Urban RunoftfStorm Sewers Unknown Nonpoint Source Unknown point source Construction/Land Development Urban Runofl/Storm Sewers Channelization Flow Regulation/Modification Unknown Nonpoint Source Unknown point source Low Low 1.5 Miles mmmmsmmmmsimtmM 28 Acres 18 Miles 0.92 Miles 0.92 Miles La Costa Resort & Spa Phase II Storm Water Management Plan Chapter 5 - FLOW-BASED BMPs 5.1 - Desiqn Criteria Flow-based BMPs shall be designed to mitigate the maximum flowrate of runoff produced from a rainfall intensity of 0.2 inch per hour. Such BMP's utilize either mechanical devices (such as vaults that produce vortex effects) or non-mechanical devices (based on weir hydraulics and specially designed filters) to promote settling and removal of pollutants from the runoff. Per the request of the City of Carlsbad, 85* percentile flow calculations were performed using the Rational Method. The basic Rational Method runoff procedure is as follows: Design flow (Q) = C * I * A Runoff Coefficient C - In accordance with the County of San Diego standards, the weighted njnoff coefficient for all the areas draining to the treatment unit was determined using the areas analyzed in the final engineering hydrology report. The runoff coefficient is based on the following characteristics of the watershed: - Land Use - Multi-Family and Commercial. - Soil Type - Hydrologic soil group D was assumed for all areas. Group D soils have very slow Infiltration rates when thoroughly wetted. Consisting chiefly of clay soils with a high swelling potential, soils with a high permanent water table, soils with clay pan or clay layer at or near the surface, and shallow soils over nearly impervious materials, Group D soils have a very slow rate of water transmission. Rainfall Intensity (I) - Regional Water Quality Control Board regulations and NPDES criteria have established that flow-based BMPs shall be designed to mitigate a rainfall intensity of 0.2 inch per hour. Watershed Area (A) - Corresponds to totai area draining to treatment unit. 5.2 - Grassy Swales Grass-lined swales, herein referred to as grassy swale, is an example of a flow- based BMP. Designed to trap pollutants through filtration, grassy swales have the following basic requirements: • Serves areas with soil groups C or D (A or B with liners) • Maximum maintained side slopes = 4:1 • Water application rate = peak flow rate from water quality design storm DE:ie H:\REPORTSV2503«)1\SWMP02.()oc W.0.2503-1 S/18/2005 9:55 AM La Costa Resort & Spa Phase 11 Storm Water Management Pian Perthe City of Portland, Oregon Stormwater Management Manual (September 2000), the swale width and profile shall be designed to convey the water quality design storm event as follows: • Maximum design depth = 0.33 foot • Maximum design velocity = 0.9 foot per second • Hydraulic residence time > 9 minutes • Minimum longitudinal slope = 1.5 percent • Maximum longitudinal slope = 5 percent • For longitudinal slopes > 5 percent, use check dams • Use Manning "n" value of 0.25 • Minimum swale length = 100 feet A minimum of 1 foot of freeboard above the standard storm design water surface shall be provided for facilities not protected by high-flow diversion devices. Velocity through the facility shall not exceed 3 feet per second during the high-flow events. The swale shall incorporate a flow-spreading device at the inlet. The flow spreader shall provide a uniform flow distribution across the swale bottom. In swales with a bottom width greater than 8 feet, a flow spreader shall be installed at least every 100 feet. To minimize flow channelization, the swale bottom shall be smooth, with uniform longitudinal slope, and with a minimum bottom width of 4 feet. Check dams may need to be installed to reduce flow channelization. Woody or shrubby vegetation shall not be planted in the active treatment area ofthe swale. Grasses shall be established as soon as possible after the swale is completed. Grasses shall be seeded within 2 days. The initial rate of application shall be 5 pounds of see mix per 1,000 square feet, or as approved by the City. All 85'" percentile mnoff from the La Costa Resort & Spa Phase II and neighboring La Costa Resort and Spa Phase I development will be treated via a single grassy swale. 5.3 - Pollutant Removal Efficiencv Table The table on the following page shows the generalized pollutant removal efficiencies for grassy swales. DE:de H:\REPORTS\2503\01VSWMP02.doc W.O.2S03-1 5/16/2005 9:55 AM Table 3. Treatment Conirol BMP Selection Matrix^\ PoButant at Concern Treatment Control BMP Categories Biofilters Detant'on Basins infiltration Basins^* Wet Ponds or Wetlands Drainage Inserts Ritration Hydrodynamic Separator Systems''' Sediment M H H H L H M Nutrients L M M M L • M L Heavy Metals M M M H L H L Organic Compounds U U U U L M L Trash & Debris L H U U M H M Oxygen Demanding Substances L M M M L M L Bactena U U H U L M L Oil & Grease M M U u L H L Pesticides U •U u u L U L (1) Ckjpemiittaes ars 8ru:ouraged to periodically assess the perfonTiance charactarisGcs of many of these BMPs to update this table. (2) Including trenches and porous pavement (3) Also known as hydrodynamic devices and baffle boxes. L: Low removal efficiency M: Medium removeil efficiency H: High removal effidency U: Unknown removal efflciency Sources: Guidanca Specifying Management Measures for Sources of Nonpoint Pollution in Coastal Waters (1993), National Stormwater Best Management Practices Database (2001), and Guide for BMP Selection in Urban Developed Areas (2001). a. Site Design BMPs Priority projects shall be designed so as to minimize, to the maximum extent practicable, the introduction of pollutants and conditions of concem that may result in significant impacts, generated from site runoff to the storm water conveyance system. Priority Projects shall also control post-development peak stonn water runoff discharge rates and velocities to maintain or reduce pre-development downstream erosion and to protect stream habitat. Although nest mandatory, priority projects can address these objectives through the creation of a hydrologically functional project design that attempts to mimic the natural hydrologic regime. Mimicking a site's natural hydrologic regime can be pursued by: » Reducing imperviousness, conserving natural resources and areas, maintaining and using natural drainage courses in the stonn water conveyance system, and minimizing clearing and grading. • Providing runoff storage measures dispersed uniformly throughout a site's landscape with the use of a variety of detention, retention, and runoff practices. • Implementing on-lot hydrologically functional landscape design and management practices. These design prindples offer an innovative approach to urban storm water management, one that does not rely on the conventional end-of-pipe or in-the-pipe Page 19 of 51 HNAL MODEL SUSMP Jointly Developed by San Diego Co-Pennittees 2/14/02, Approved by SDRWQCB 5/12/02 La Costa Resort & Spa Phase II Storm Water Management Plan 5.4 - Maintenance Requirements Maintenance for grassy swales is minimal and aimed at keeping grass cover dense and vigorous. A pest management plan should be developed for vegetated areas specifying how problem insects and weeds will be controlled with minimal use of insecticides and herbicides. Lawn-mowing should be performed routinely throughout the growing season. Grass height should be maintained at two inches above the design water depth. Swales should be inspected at least twice annually to check for erosion and damage to vegetation, debris and litter. Excess sediment should be removed periodically as determined through inspection. 5.5 - Operations and l\/laintenance Plan & Costs Maintenance for grassy swales will consist of: o Trash and Debris Removal o Grass height maintenance (Mowing) o Sediment Removal All costs of maintaining the water quality basin will be the responsibility of the La Costa Resort & Spa Phase II Homeowners Association and also the La Costa Resort and Spa. The following outlines approximate Annual Maintenance costs for the proposed grassy swales: - Cut Vegetation to average height of 6" = $540 - Ensure adequate vegetation = $550 - Inspect for debris and sediment = $1,050 General Maintenance - Inspection = $750 Subtotal = $2890 10% Contingency = $289 Approximate Total Annual Maintenance Costs of Swale = $3200 DE:de H:\RePORTS\2503\01\SWMP02.doc WJl. 2503-1 5/ie«105 9:S5AM Grassy Swale Description: Grassy swales are long narrow grassy depressions used to coUect and convey stormwater runoff, aUowing poUutants to settle and fUter out as the water infiltrates into the ground or flows through the faciHty. In addition to providing poUution reduction, flow rates and volumes can also be managed for smaU projects (<15,000 square feet of impervioxis surface) with grassy swales. Swales should be integrated into the overaU site design and can be used to help fulfUl a site's required landscaping area requirement An approved conveyance and disposal method per Section 1.4 wiU be required at the end of the swale. Design Considerations: When designing grassy swales, slopes and depth should be kept as mUd as possible to avoid safety risks and prevent erosion within the facility. Construction Considerations: Grassy swale areas should be clearly marked before site work begins to avoid soU disturbance during construction. No vehicular traffic, except that specificaUy used to construct the faciUty, should be aUowed within 10 feet of swale areas. Design Requirements: Son Suitability: Grassy swales are appropriate for aU soU types. TopsoU shaU be used within the top 12 inches of the facUity, or the soU shaU be amended per Appendix F to support plant growth. Dimensions and Slopes: FacUity storage depth may vary from 6 to 12 inches. Maximum side slopes are 4 horizontal to 1 vertical. Minimum flat bottom width is 2 feet for private swales, and 4 feet for pubUc swales. Maximum longitudinal slope is 5%, whUe minimum slope is 0.5%. Maximum surrounding ground slopes shaU be 10%. Stormwater Management Manual Adopted JxUy 1,1999; revised September 1,2004 Page 2-70 Grassy Swale Setbacks: Required setback from centerUne of swale to property lines is 5 feet, and 10 feet from buUding foundations unless Hned with impermeable fabric. Sizing: Grassy swales sized with the simpHfied approach shaU be designed to receive less than 15,000 square-fe§t of impervioiis area mnoff. For fhese projects, a simplified approach sizing factor of 0.1 may be used to receive credit for poUution reduction and flow control. A high-flow by-pass mechanism wUl not be required in fhese cases, but a high-flow overflow must be provided at the downstream end of the swale to an approved disposal point, per Section 1.4. In cases when poUution reduction is the only stormwater management goal, or there is more than 15,000 square feet of impervious area to manage, fhe presumptive approach must be used size the swale for poUution reduction, and additional facUities wUl be required to meet flow control requirements, where appHcable. Presumptive Approach Sizing Criteria: Exhibit 2-15 shows swale side slopes of 4:1 and lengthwise slopes of IV2 percent, 3 percent, and 5 percent. These charts are based on the City standards shown below and may be used to easUy determine swale length, given the peak flow rate and the desired swale bottom width. Stormwater Management Manual Page 2-71 Adopted July 1,1999; revised September 1,2004 Grassy Swale 0) a j£ D) C 0) _J (0 180 170 160 150 140 130 120 110 100 90 Exhibit 2-15 (Sheetl) Swaie Length at 1.5% Longitudinal Slope Bottom Width = 6' Bottom Width = 4' ^.-^Bottom Width = 8' Swale Data Side slopes are 4:1 Minimum length is 100' 1 1 Side slopes are 4:1 Minimum length is 100' 1 1 1 1 1 Side slopes are 4:1 Minimum length is 100' 1 1 0.2 0.4 0.6 Flow Rate, Q, cfs 0.8 Stormwater Management Manual Adopted July 1,1999; revised September 1,2004 Page 2-72 Grassy Swale 270 250 230 210 190 170 150 130 110 90 Exhibit 2-15 (Sheet 2) Swale Length at 3.0% Longitudinal Slope Swale Data Side slopes are 4:1 Minimum length is 100" Bottom Wicith = 4' 0.4 0.6 0.8 Flow Rate, Q, cfe 1.2 1.4 1.6 340 290 240 ra c 0) 190 140 90 Exhibit 2-15 (Sheet 3) ; \ Bottom Width = 1 1 6- ; 1 ^^,00-^ Swale Data Side slopes are 4:1 Minimum length is 100' Bottom Width = 4' Swale Data Side slopes are 4:1 Minimum length is 100' ^^^"^ ^^^^ Bottom Width = 8' - 1 1 , ! 1 ^ 1 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 Flow Rate, Q, cfs Stormwater Management Manual Adopted July 1,1999; revised September 1,2004 Page 2-73 Grassy Swale 1) The swale widfh and profile shaU be designed to convey runoff from the poUution reduction design storm intensity (see Section 1.5.2) at • Maximum design depth of 0.33 feet • Maximimi design velocity of 0.9 feet per second. • Minimum hydrauHc residence time (time for Qdesign to pass through the swale) of 9 minutes. • Minimum longitudinal slope of 0.5 percent, maximum slope of 5 percent For slopes greater than 5 percent, check dams shaU be used (one 6-inch high dam every 10 feet). • Designed using a Manning "n" value of 0.25. • 4:1 (or flatter) side slopes in the treatment area. • Minimum length of 100 feet A minimimi of 1 foot of freeboard above the water surface shaU be provided for facilities not protected by high-flow storm diversion devices. Swales without high-flow diversion devices shaU be sized to safely convey the 25-year storm event, analyzed using the Rational Method (peak 25- year, 5 minute intensity = 3.32 inches per hour). Velocity through the faciHty shaU not exceed 3 feet per second (fps) during the high-flow events (i.e., when flows greater than those resulting from the poUution reduction design intensity are not passed around the faciHty). 2) The swale shaU incorporate a flow-spreading device at fhe inlet The flow spreader shaU provide a uniform flow distribution across fhe swale bottom. In swales with a bottom width greater than 6 feet a flow spreader shaU be instaUed at least every 50 feet. 3) To minimize flow channeHzation, the swale bottom shaU be smooth, with uniform longitudinal slope, and with a nunimum bottom widfh of 2 feet for private facUities and 4 feet for pubHc faciHties. Maximum bottom width shaU be 8 feet. 4) Grasses or sod shaU be estabUshed as soon as possible after the swale is completed, and before water is aUowed to enter the faciHty. 5) Unless vegetation is established, biodegradable erosion control matting appropriate for low-velodty flows (approximately 1 foot per second) shaU be instaUed in the flow area of the swale before aUowing water to flow through the swale. Stormwater Management Manual Page 2-74 Adopted July 1,1999; revised September 1, 2004 Grassy Swale 6) Access routes to the swale for maintenance pmrposes must be shown on the plans. PubHc swales wUl need to provide a minimum 8-foot wide access route, not to exceed 10 percent in slope. Stormwater Report Requirements For Presumptive Approach: See Exhibit 2-2. Landscaping: Plantings shaU be designed at the foUowing quantities per 200 square feet of facUity area. FaciHty area is equivalent to the area of the swale calculated from Form SIM. (Note: FaciHties smaUer than 200 square feet shaU have a mirumum of one tree per faciHty.): 1 Evergreen or Deciduous tree: Evergreen trees: Minimum height 6 feet Deciduous trees: Minimum caHper: 1 V2 inches at 6 inches above base. Grass: Seed or sod is required to completely cover the grassy swale bottom and side slopes. (Shrubs are optional) For the swale flow path, approved native grass mixes are preferable and may be substituted for standard swale seed mix. Seed shaU be appHed at fhe rates specified by fhe suppHer. The appHcant shaU have plants established at the time of faciHty completion (at least 3 months after seeding). No runoff shaU be aUowed to flow in the swale until grass is established. Trees and shrubs may be aUowed in the flow path wilhin swales if fhe swale exceeds fhe minimum length and widths specified. Native wUdflowers, grasses, and ground covers used for BES-maintained facUities shaU be designed not to reqtiire mowing. Where mowing cannot be avoided, faciHties shaU be designed to require mowing no more than once or twice annuaUy. Turf and lawn areas are not aUowed for BES-maintained faciHties; any exceptions wiU require BES approval. Environmental zones shaU meet requirements established by Titie 33 for grass in E-zones. *Link to Grassy Swale Recommended Seed Mixes Checklist of minimal information to be shown on the permit drawings: (Additional information may be required on the drawings diuing permit review, depending on individual site conditions.) Stormwater Management Manual Page 2-75 Adopted July 1,1999; revised September 1,2004 Grassy Swale 1) FacUity dimensions and setbacks from property lines and structures 2) Profile view of facUity, including typical cross-sections with dimensions 3) Growing mediiun spedfication 4) FUter fabric specification (if appHcable) 5) AU stormwater piping associated with fhe fadHty, including pipe materials, sizes, slopes, and invert elevations at every bend or connection 6) Landscaping plan Inspection requirements and schedtde: The foUowing table shaU be used to determine which stormwater fadUty components require Qty inspection, and when the inspection shaU be requested: Facility Component Inspection Requirement Swale grading CaU for inspection Piping CaU for inspection FUter fabric (if appHcable) Growing medium Plantings/ seeding/ sod CaU for inspection Operations and Maintenance requirements: See Chapter 3.0. * Link to grassy swale O&M form Additional photos and drawings: Link to grassy swale photos Link to grassy swale drawings Stormwater Management Manual Page 2-76 Adopted July 1,1999; revised September 1,2004 La Costa Resort & Spa Phase II Storm Water Management Plan CHAPTER 6 - SOURCE CONTROL BMPS 6.1 - Landscapinq Manufactured slopes shall be landscaped with suitable ground cover or installed with an erosion control system. Homeowners will be educated as to the proper routine maintenance to landscaped areas including trimming, pruning, weeding, mowing, replacement or substitution of vegetation in ornamental and required landscapes. Per the RWQCB Order, the following landscaping activities are deemed unlawful and are thus prohibited: - Discharges of sediment - Discharges of pet waste - Discharges of vegetative clippings - Discharges of other landscaping or construction-related wastes. 6.2 - Urban Housekeepinq Fertilizer applied by homeowners, in addition to organic matter such as leaves and lawn clippings, all result in nutrients in storm water runoff. Consumer use of excessive herbicide or pesticide contributes toxic chemicals to runoff. Homeowners will be educated as to the proper application of fertilizers and herbicides to lawns and gardens. The average household contains a wide variety of toxins such as oil/grease, antifreeze, paint, household cleaners and solvents. Homeowners will be educated as to the proper use, storage, and disposal ofthese potential storm water runoff contaminants. Per the RWQCB Order, the following housekeeping activities are deemed unlawful and are thus prohibited: Discharges of wash water from the cleaning or hosing of impervious surfaces Including parking lots, streets, sidewalks, driveways, patios, plazas, and outdoor eating and drinking areas (landscape irrigation and lawn watering, as well as non-commercial washing of vehicles in residential zones, is exempt from this restriction) Discharges of pool or fountain water containing chloride, biocides, or other chemicals Discharges or runoff from material storage areas containing chemicals, fuels, grease, oil, or other hazardous materials Discharges of food-related wastes (grease, food processing, trash bin wash water, etc.). DE:(le H:\REPORTS\2503\01\SWMP02.doc W.CI. 2503-1 5/16/2005 9:55 AM La Costa Resort & Spa Phase II Storm Water Management Pian 6.3 - Automobile Use Urban pollutants resulting from automobile use include oil, grease, antifreeze, hydraulic fluids, copper from brakes, and various fuels. Homeowners will be educated as to the proper use, storage, and disposal of these potential storm water contaminants. Per the RWQCB Order, the following automobile use activities are deemed unlawful and are thus prohibited: - Discharges of wash water from the hosing or cleaning of gas stations, auto repair garages, or other types of automotive service facilities. Discharges resulting from the cleaning, repair, or maintenance of any type of equipment, machinery, or facility including motor vehicles, cement- related equipment, port-a-potty servicing, etc. Discharges of wash water from mobile operations such as mobile automobile washing, steam cleaning, power washing, and carpet cleaning. The Homeowners Association will make all homeowners aware of the aforementioned RWQCB regulations through a homeowners' education program. Sample information has been provided at the end of this chapter. 6.4 - Site Desiqn BMPs Priority projects, such as the La Costa Resort & Spa Phase II development, shall be designed to minimize, to the maximum extent practicable the introduction of pollutants and conditions of concern that may result in significant Impact, generated from site runoff to the storm water conveyance system. Site design components can significantly reduce the impact of a project on the environment The following design techniques have been proposed to accomplish this goal. - Implementing on-lot hydrologically functional landscape design and management practices; Additional detail regarding landscaping design is discussed in section 6.1. - Minimizing project's impervious footprint. Methods of accomplishing this goal include constructing streets, sidewalks, and parking lots to the minimum widths necessary without compromising public safety. Another example for minimizing impervious area includes incorporating landscaped areas in the drainage system to encourage infiltration and reduce the amount of directly connected impervious areas. - Minimizing directly connected Impervious Areas. Where landscaping Is proposed, drain rooftops into adjacent landscaping prior to discharging to the storm water conveyance system. DE:tle H:\REPORTS\2503\01\SWMP02.()oc W.O. 2503-1 5/18/2005 9:55 AM A clean environment is important to all of us! Did you know that storm drains are NOT connected to sanitary sewer systems and treatment plants? The primary purpose of storm drains is to carry rainwater away from developed areas to prevent flooding. Untreated storm water and the pollutants it carries, flow directly into creeks, lagoons and the ocean. In recent years, sources of water pollution like industrial waters from factories have been greatly reduced. However now, the majority of water pollution occurs from things like cars leaking oil, fertilizers from farms, lawns and gardens, failing septic tanks, pet waste and residential car washing Into the storm drains and into the ocean and watenways. All these sources add up to a pollution problem! But each of us can do small things to help clean up our water and that adds up to a pollution solution! Motor oil photo Is used courtesy of the Water Quality Consortium, a cooperative venture between the Washington State Department of Ecology, King County and the cities of Bellevue, Seattle and Tacoma. Only Rain in the Storm DrainI City of Carlsbad Storm Water Protection Program City of Carlsbad 1635 Faraday Avenue Carlsbad CA 92008 Storm Water HOTIine: 760-602-2799 Funded by a grant from the California Integrated Waste Management Board Motor Oil Only Rain in the Storm Drain! City of Carlsbad Storm Water Protection Program Storm Water HOTIine: 760-602-2799 ^ \Printed on recycled paper What's the problem with motor oil? How can YOU help keep our environment clean? mi •It! •i Oil does not dissolve in water. It lasts a long time and sticks to everything from beach sand to bird feathers. Oil and other petroleum products are toxic to people, wildlife and plants. One pint of oil can make a slick larger than a football field. Oil that leaks from our cars onto roads and driveways is washed into storm drains, and then usually flows directly to a creek or lagoon and finally to the ocean. Used motor oil is the largest single source of oil pollution in our ocean, creeks and lagoons. Americans spill 180 million gallons of used oil each year Into our waters. This is 16 times the amount spilled by the Exxon Valdez In Alaska. Having a clean environment is of primary importance for our health and economy. Clean waten/vays provide commercial opportunities, recreation, fish habitat and add beauty to our landscape. YOU can help keep our ocean, creeks and lagoons clean by applying the following tips: • Stop drips. Check for oil leaks regulariy and fix them promptly. Keep your car tuned to reduce oil use. • Use ground cloths or drip pans beneath your vehicle if you have leaks or are doing engine work. • Clean up spills immediately. Collect all used oil in containers with tight fitting lids. Do not mix different engine fluids. 4 When you change your oil, dispose of it properly. Never dispose of oil or other engine fluids down the storm drain, on the ground or into a ditch. • Recycle used motor oil. There are several locations in Carisbad that accept used motor oil. For hours and locations, call 760-434-2980. • Buy recycled ("refined") motor oil to use in your car. What you should know before using Concrete and Mortar ... in the City of Carlsbad, storm drains flow directly into local creeks, lagoons and the ocean without treatment. Storm water pollution is a serious problem for our natural environment and for people who live near streams or wetlands. Storm water pollution comes from a variety of sources including oil, fuel, and fluids, from vehicles and heavy equipments, pesticide runoff from landscaping, and from materials such as concrete and mortar from construction activities. The City of Carlsbad is committed to improving water quality and reducing the amount of pollutants that enter our precious waterways. A Clean Environment is Important to All of Usi \othes. '^^Protec'^°'' City of Carlsbad l^&P 1635 Faraday Avenue Carlsbad, CA 92008 Storm Water HOTIine: 760-602-2799 stormwater@ci.carlsbad.ca.us March 2003 nly Rain in the Storm Drain! Pollution Prevention is up to YOU! Did you know that storm drains are NOT connected to sanitary sewer systems or treatment plants? The primary purpose of storm drains is to carry rainwater away from developed areas to prevent flooding. Untreated pollutants such as concrete and mortar flow directly into creeks, lagoons and the ocean and are toxic to fish, wildlife, and the ' aquatic environment Disposing ofthese materials into storm drains causes serious ecological problems—and is PROHIBITED by law. Do the Job Right! This brochure was designed for do-it- yourself remodelers, homeowners, masons and bricklayers, contractors, and anyone else who uses concrete or mortar to complete a construction project Keep storm water protection in mind whenever you or people you hire work on your house or property. STORM WATER HOTLINE 760-602-2799 Best Management Practices Best Management Practices or BMPs are procedures and practices that help to prevent pollutants such as chemicals, concrete, mortar, pesticides, waste, paint, and other hazardous materials from entering our storm drains. All these sources add up to a pollution problem. But each of us can do our part to keep storm water clean. These efforts add up to a pollution solution! What YOU Can Po: • Set up and operate small mixers on tarps or heavy plastic drop cloths. • Don't mix up more fresh concrete or mortar than you will need for a project. • Protect applications of fresh concrete and mortar from rainfall and runoff until the material has dried. • Always store both dry and wet materiais under cover, protected from rainfall and runoff and away from storm drains or waterways. • Protect dry materials from wind. Secure bags of concrete mix and mortar after they are open. Don't allow dry products to blow into driveways, sidewalks, streets, gutters, or storm drains. • Keep all construction debris away from the street, gutter and storm drains. Never dispose of washout into the street, storm drains, landscape drains, drainage ditches, or streams. Empty mixing containers and wash out chutes onto dirt areas that do not flow to streets, drains or waterways, or allow material to dry and dispose of properiy. Never wash excess material from bricklaying, patio, driveway or sidewalk construction into a street or storm drain. Sweep up and dispose of small amounts of excess dry concrete, grout, and mortar in the trash. Wash concrete or brick areas only when the wash water can flow onto a dirt area without further runoff or drain onto a surface which has been bermed so that the water and solids can be pumped off or vacuumed up for proper disposal. Do not place fill material, soil or compost piles on the sidewalk or street. If you or your contractor keep a dumpster at your site, be sure it is securely covered with a lid or tarp when not in use. During cleanup, check the street and gutters for sediment, refuse, or debris. Look around the corner or down the street and clean up any materials that may have already traveled away from your property. {OT connected to sanitary sewer ^:systems and treatment plants? The primary purpose of storm drains is to carry rainwater away from developed areas to prevent flooding. Untreated storm water and the pollutants it carries flow directly into creeks, -lagoons and the ocean. iln recent years, sources of water 5£ -pollution like industrial waters from ^y'factories have been greatly reduced. ^ However, now the majority of water pollution occurs from things like cars leaking oil, fertilizers from farms and •'•gardens, failing septic tanks, pet waste :jt" and residential car washing into the storm drains and into the ocean and :watenways. |vAII these sources add up to a pollution i'jsroblem! But each of us can do our Bart tb help clean up our water and mi pfb'at adds up to a pollution solution! Car washing courtesy of Quality Con cooperative between the|^| State Depart " Ecology, Kin the cities of Seattle and City of CarJ 1635 Farac ^ Carlsbad Storm Wat? 760-602-2: i's no problem with washing your ijSar. It's just how and where you do it. •Mostsoap contains phosphates and other chemicals that harm fish and water quality. The soap, together with 1^*. the dirt, metal and oil washed from your car, flows into nearby storm •drains which run directly into lakes, livers or marine waters. tt^ phosphates from the soap can •Kise excess algae to grow. Algae Bi bad, smell bad, and harm water ;quality. As algae decay, the process uses up oxygen in the water that fish need. How can YOU help keep the environment clean? Having a clean environment is of primary importance for bur health and economy. Clean waten/vays provide commercial opportunities, recreation, fish habitat and add beauty to our '*j!r. landscape. YOU can help *• keep our ocean, creeks and lagoons clean by applying the follovving tips: • Use soap sparingly. <? Use a hose nozzle with a trigger to jsave water. • Pour your bucket of soapy water down the sink when you're done, not -In, the street. • Avoid using engine and wheel fcleaners or degreasers. |B6^' • Take your car to a commercial car ii?" wash, especially ifyou plan to clean the engine or the bottom of your car. Most car washes reuse wash water several times before sending it to the sewer system for treatment. • Hire only mobile detail operators that will capture wash water and chemicals. It is unlawful for commercial vehicle washing operators to allow wash water to enter the storm drain system. A Clean Environment is Important to All of Us! In the City of Carlsbad, storm drains flow directly into local creeks, lagoons and the ocean without treatment. Storm water pollution is a serious problem for our natural environment and for people who live near streams or wetlands. Storm water pollution comes from a variety of sources including oil, fuel, and fluids, from vehicles and heavy equipment, pesticide runoff from landscaping, and from materials such as concrete, mortar and soil from construction activities. The City of Carlsbad is committed to improving water quality and reducing the amount of pollutants that enter our precious waterways. Storm Water Protection Program stormwater@ci.carlsbad.ca.us 760-602-2799 City of Carlsbad 1635 Faraday Avenue Carlsbad, CA 92008 Printed on recycled paper "St.,;;.-' It's All Just Water, Isn't It? Only Rain in the Storm brain! How Do I Get Rid of Chlorine? Pool Filters Although we enjoy the fun and relaxing times in them, the water used in swimming pools and spas can cause problems for our creeks, lagoons and the ocean if not disposed of properly. When you drain your swimming pool, fountain or spa to the street, the high concentrations of chlorine and other chemicals found in the water flows directly to our storm drains. Did you know that these storm drains are NOT connected to sanitary sewer systems and treatment plants? The primary purpose of storm drains is to carry rainwater away from developed areas to prevent flooding. Improperly disposing of swimming pool and spa water into storm drains may be harmful to the environment. Best Management Practices Best Management Practices or B/WPs are procedures that help to prevent pollutants like chlorine and sediment from entering our storm drains. Each of us can do our part to keep storm water clean. Using BMPs adds up to a pollution solution! Pool and spa water may be discharged to thc storm drain if it has been properly dechlorinated and doesn't contain other chemicals. The good news is that chlorine naturally dissipates over time. Monitor and test for chlorine levels in the pool over a period of 3 to 5 days. Drain the water before algae starts to grow. Consider hiring a professional pool service company to clean your pool, fountain, or spa and make sure they dispose of the water and solids properly. For more information about discharging wastewater to the sanitary sewer, please contact the Encina Wastewater Authority at (760) 438- 3941. Before you discharge your swimming pool or spa water to the storm drain, thc water: • Must not contain chlorine, hydrogen peroxide, acid, or any other chemicals. • Can not carry debris or vegetation. • Should have an acceptable pH of 7-8. • Can not contain algae or harmful bacteria (no "green" present). • Flow must be controlled so that it does not cause erosion problems. Clean filters over a lawn or other landscaped area where the discharge can be absorbed. Collect materials on filter cloth and dispose into the trash. Diatomaceous earth cannot be discharged into the street or storm drain systems. Dry it out as much as possible, bag it in plastic and dispose into the trash. Acid Washing Acid cleaning wash water is NOT allowed into the storm drains. Make sure acid washing is done in a proper and safe manner that is not harmful to people or the environment. It may be discharged into the sanitary sewer through a legal sewer connection after the pH has been adjusted to no lower than 5.5 and no higher than 11. Do the Job Rightl • Use the water for irrigation.Try draining de-chlorinated pool water gradually onto a landscaped area. Water discharged to landscape must not cross property lines and must not produce runoff. • Do not use copper-based algaecides. Control algae with chlorine or other alternatives to copper-based pool chemicals. Copper is harmful to the aquatic environment. • During pool construction, contain ALL materials and dispose of properly. Materials such as cement, Gunite, mortar, and sediment must not be discharged into the storm drains. }id you know that storm drains are iNOT connected to sanitary sewer kystems and treatment plants? The primary purpose of storm drains •V IS to carry rainwater away from developed areas to prevent flooding. Untreated storm water and the pollutants it can-ies, flow directly into creeks, lagoons and the ocean. 'In recent years, sources of water p pollution lil<e industrial waters from iactories have been greatly reduced, however now, the majority of water Fpollution occurs from things lil<e cars Idaking oil, fertilizers from farms and >ff-gardens^ failing septic tanks, pet ^.^waste and residential car washing into Slhe storm drains and into the ocean and watenvays. ^•i^ll these sources add up to a pollution Iproblemi But each of us can do small 1 hgs to help clean up our water and iat adds up to a pollution solution! it-.' What's the problem with fertilizers and pesticides? Fertilizer isn't a problem—IF it's used carefully. If you use too much fertilizer or apply it at the wrong time, it can easily wash off your lawn or garden into storm drains and then flow untreated into lakes or streams. Just like in your garden, fertilizer in lagoons and streams makes plants grow. In water bodies, extra fertilizer can mean extra algae and aquatic plant growth. Too much algae harms water quality and makes boating, fishing and swimming unpleasant. As algae decay, they use up oxygen in the water that fish and other wildlife need. Fertilizer photo is used courtesy of the Water Quality Consortium, a cooperative venture between the Washington State Department of Ecology, King County and the cities of Bellevue, Seattle and Tacoma. Storm Water HOTIine: 760-602-2799 stormwater@>cl .carlsbad.ca.us City of Carlsbad 1635 FaradayAvenue Carlsbad CA 92008 www.ci .carl s bad .ca.us £^ ^Printed on recydod paper How can YOU help keep the environment clean? -laving a clean environment is of fpnmary importance for our health and ^conomyi Clean watenn/ays provide jmmercial opportunities, recreation, fish habitat and add beauty to our landscape. YOU can help keep our ^creeks lagoons and ocean clean by Ifpplying the following tips: &h Don't blow or rake leaves and other yard waste into the street or gutter. ft' Recycle yard waste or start your own *^ compost pile. Don't over irrigate. Use drip • irrigation, soaker hoses or micro- fj; spray system and water early in the 5.^ morning. f' • If you have a spray head sprinkler ^•.jssystem, consider adjusting your vatering method to a cycle and I soak Instead of watering for 15 '"^^ minutes straight, break up the session into 5 minute intervals allowing water to soak in before the next application. Keep irrigation systems well- maintained and water only when needed to save money and prevent over-watering. Use fertilizers and pesticides sparingly. Have your soil tested to determine the nutrients needed to maintain a healthy lawn. Consider using organic fertilizers— they release nutrients more slowly. Leave mulched grass clippings on the lawn to act as a natural fertilizer. • Use pesticides only when absolutely necessary. Use the least toxic product intended to target a specific pest, such as insecticidal soaps, boric acid, etc. Always read the label and use only as directed. • Use predatory insects to control hannful pests when possible. • Properly dispose of unwanted pesticides and fertilizers at IHousehold Hazardous Waste collection facilities. For more information on landscape irrigation, piease call 760438-2722. Master Gardeners San Diego County has a Master Gardener program through the University of California Cooperative Extension. Master Gardeners can provide good infonnation about dealing with specific pests and plants. You may call the Master Gardener Hotline at 858-694-2860 or check out their website at www.masterqardenerssandieqo.org. The hotline is staffed Monday—Friday, 9 am—3 pm, by experienced gardeners who are available to answer specific questions. Information from Master Gardeners is free to the public. La Costa Resort & Spa Phase 11 Storm Water Management Plan CHAPTER 7 - TREATMENT CONTROL BMP DESIGN GRASSY SWALE 7.1 - BMP Locations The proposed grassy swale is located within the existing natural open space to the west ofthe proposed La Costa Resort & Spa Phase 11 development, bordering the adjacent El Camino Real (see BMP Location Map on the following page). 7.2 - Determination of Design Treatment Flows The BS*' percentile design flow rates have been calculated using the Rational Method. Required data for the Rational Method treatment flow determination include the following: - Runoff Coefficient (C) = 0.82 for Commercial Development - Rainfall Intensity (I) = 0.20 inches per hour Drainage area to treatment unit (A) The following table summarizes the parameters used for determination of design flows to the grassy swale. DESIGN RUNOFF DETERMINATION SUMMARY TABLE BMP Drainage Area (acres) Rainfall Intensity (inches/hour) Runoff Coefflcient 85*" Pct. Design Flow (cfs) Grassy Swale 23.3* 0.2 0.82 3.8 *Note: Inclusive of the adjoining La Costa Resort and Spa Phase I 7.3 - Grassy Swale Sizinq The grassy swale has been designed with a 20 foot bottom width, a depth of 0.33 ft, a channel slope of 4% and a side slope of 1:3. The required flow length to attain the 9 minute hydraulic residence time is 296.3 linear feet. Based on these parameters, calculations (included at the end of this chapter) show the grassy swale is capable of treating a peak flow of 3.8 cfs (refer to section 5.1 for treatment flow determination and treatment flow determination spreadsheet at the end ofthis chapter). DErde H:tREPORTS\2S03\01\SWMP02.dac W.0.2503-1 5/18/2005 9:55 AM _/4— r-BMP LOCATION EXHIBIT FOR l_A COSTA RESORT & SPA PHASE 2 CITY OF CARLSBAD, CALIFORNIA SHEET 1 OF 1 R\06l5\lHyd\615»H03-BHP*.BC S085>tay-l8-eiXI5.HMI) 85TH PERCENTILE PEAK FLOW AND VOLUME DETERMINATION Modified Rational Method - Effective for Watersheds < 1.0 mi^ Hunsaker & Associates - San Diego Note: Only Enter Values in Boxes - Spreadsheet Will Calculate Remaining Values Project Name La Costa Resort & Spa Phase 2 | Work Order 2503-1 1 Jurisdiction City of Carlsbad | BMP Location {Open Space adjacent to El Camino ReaT Developed Drainage Area = 23.3 Natural Drainage Area = 0.0 Total Drainage Area to BMP = 23.3 Dev. Area Percent Impervious = 85 1 Overall Percent Impervious = 85 Dev. Area Runoff Coefficient = 0.82 Nat. Area Runoff Coefficient = Runoff Coefficient = 0.82 Time of Concentration = 13.8 1 (from Drainage Study) RATIONAL METHOD RESULTS acres acres acres Q = CIA where Q = 85th Percentile Peak Flow (cfs) C = Runoff Coefficient I = Rainfall Intensity (0.2 inch/hour per RWQCB mandate) A = Drainage Area (acres) Using tlie Total Drainage Area: C = 0.82 I = 0.2 inch/hour A= 23.3 acres Q = 3.82 cfs Villas of La Costa Grassy Swaie Grassy Swale Sizing (based on Manning's Equation) Given: Manning's n = 0.25 Bottom Width = 20.0 ft. Side Slope, z = 3.0 Channel Slope = 0.04 ft/ft if Depth = 0.33 ft Hyd. Residence Time = 9.0 min Results then Q = 3.80 cfs Flow Area = 6.927 ft^ Wetted Perimeter = 22.09 ft Top Width = 21.98 ft Velocity = 0.55 fps Swale Length = 296.3 ft La Costa Resort & Spa Phase II Storm Water Management Plan CHAPTER 8 - REFERENCES "Standard Urban Storm Water Mitigation Plan - Storm Water Standards", City of Carisbad, April 2003. "Standards for Design and Construction of Public Works Improvements in the City of Carlsbad", City of Carisbad, California; April 1993. "Master Drainage and Storm Water Quality Management Plan", City of Carisbad, Califomia; March 1994. "Drainage Study for La Costa Resort and Spa - Phases I & IF, Hunsaker & Associates; May, 2005. "Hydrology Manual", County of San Diego Department of Public Worths - Flood Control Division; Updated April 1993. "San Diego County Hydrology Manual", County of San Diego Department of Public Worths - Flood Control Section; June 2003. "Order No. 2001-01, NPDES No. CAS0108758 - Waste Discharge Requirements for Discharges of Urban Runoff from the Municipal Separate Stonv Sewer Systems (MS4s) Draining the Watersheds ofthe County of San Diego, the Incorporated Cities of San Diego County, and San Diego Unified Port District", California Regional Water Quality Control Board - San Diego Region; February 21, 2001. "Water Quality Plan for the San Diego Basin", California Regional Water Quality Control Board - San Diego Region, September 8,1994. DE:de H:\REPORTS\2503\01\SWMP02.dOC w.0.2503-1 5/18/2005 9:55 AM