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HomeMy WebLinkAboutCT 00-20; FOX MILLER PROPERTY; SEWER STUDY; 2004-02-05I I I '~I I I I I' I I I. I I. I I I I -I I SEWER STUDY FOR THE ,IIY O~ \J \r I FOX-MILLER PROJECT fl,/ ~ IN THE CITY OF CARLSBAD February 5, 2004 Prepared by: Dexter Wilson Engineering, Inc. 703 Palomar Airport Road Suite 300 Carlsbad, CA 92009 Job No. 791-001 RECEIVED fEB 05 2004 ENG\NEeR\NG DEPARTMENT I I I I I I I I I I I I I I I I I I I DEXTER WILSON ENGINEERING, INC. February 5, 2004 Ladwig Design Group 703 Palomar Airport Road, Suite 300 Carlsbad, CA 92009 Attention: Bob Ladwig, President DEXTER S. WILSON, P.E. ANDREW M. OVEN, P.E. STEPHEN M. NIELSEN, P;E. MICHAELJ. FILECCIA, P.E. 791-001 Subject: Sewer Study for the Fox-Miller Project in the City of Carlsbad Introduction This report provides an analysis of the offsite sewer system impacts for the Fox-Miller project. The analyses performed verify that sewer capacity is available in the gravity sewer lines'downstream of the connection point for the Fox~Miller project. Project Overview The Fox-Miller project is located south of EI Camino Real and east of College Boulevard. The northeastern property boundary follows along a port;ion of the EI Camino Real right-of-way between College Boulevard and Faraday Avenue. Access to this property will be along the extension of Salk Avenue which will extend thrc:mgh the property and connect to EI Camino Real. Figure 1 at the back of this report shows the general location of this project. 703 PALOMAR AIRPORT ROAD, SUITE 300 • CARLSBAD, CA 92009 • (760) 438-4422 • FAX (760) 438-0173 I I I I I I I I I I I I I I I I I I I Bob Ladwig Februl:\ry 5, 2004 The Fox-Miller project proposes a total of four industrial park lots. A fifth lot is designated as Open Space. Finish grades for the industrial lots within the project range in elevation from a low of 230 feet to a high of 290 feet in elevation. The project . generally slopes to the west toward College Boulevard. Design Criteria Design criteria for the evaluation of the sewer systems for the Fox-Miller project are in accordance with the Carlsbad Standard Sewer System Design Criteria and Standard Drawings & Specifications dated May 11, 1993. The main criteria used for this study are summarized below. Sewage generation is calculated based upon the number of equivalent dwelling units (EDUs). The generation factor for each EDU is 220 gpd average.flow. Peak sewage flow is calculated as 2.5 times the average daily sewage flow. Depth offlow criteria for gravity sewers requires peak sewage flow to be less than half full for 10-inch and smaller lines, and up to three-quarters full for 12-inch and larger lines. Sewage Generation The expected sewage generated by the Fox-Miller project is estimated using a demand factor of220 gallons per day per Equivalent Dwelling Unit. Equivalep.t Dwelling Units were determined based upon the following criteria for Industrial Land Use: Building coverage estimated to be 40% of net pad area; Sixty percent of building estimated to be warehouse space; Forty percent of building estimated to be o#J.ce space; DEXTER WILSON ENGINEERING, INC. PAGE 2 I I I I I I I I I I I I I I I I I I I Bob Ladwig February 5, 2004 For warehouse space, 1 EDU = 5,000 sq. ft. For office space, 1 EDU = 1,800 sq. ft. One EDU = 550 gpd average demand. Table 1 below presents a summary of the methodology for calculating the projected sewage flows from the Fox-Miller project. The average sewage flow is estimated to be 28,204 gpd or 19.6 gpm. 1 3.3 57,499 6.9 12.8 19.7 4,329 2 6.7 116,741 14.0 25.9 40.0 8,789 3 5.1 88,862 10.7 19.7 30.4 6,690 4 6.4 111,514 13.4 24.8 38.2 8,396 Existing Facilities There is one existing gravity sewer line in the vicinity of the Fox-Miller project. To the west of the property, located in Salk Avenue, is an 8-inch gravity sew~r line which runs north on Fermi Court and turns west on El Camino Real. This 8-inch gravity sewer extends west in El Camino Real up to the intersection with Rancho Carlsbad Drive/Jackspar Drive. At this intersection, the 8-inch gravity sewer conne~tsto the 24-inch South Agua Hedionda Interceptor Reach SAHTIG. Sewer flow continues northwest to the Cannon Road area where the sewer system turns west onto Cannon Road. DEXTER WILSON ENGINEERING, INC. PAGE .3 I I I I I I I I I I I I I I I I I I I Bob Ladwig February 5,2004 Figure 1 at the back of this report shows the existing offsite gravity sewer system which is being analyzed for the Fox-Miller project. Overview of Sewer Service The Fox-Miller project is within the South Agua Hedionda sewer draina~e basin and will be paying the sewer benefit area fees for this basin. Ultimately, all the sewerage generated by this project will be conveyed through the South Agua Hedionda Interceptor System to the Encina Water Pollution Control Facility which is "located between Avenida Encinas and the Interstate 5 Freeway south of Palomar Ai~port Road. Based upon the location of the Fox-Miller project, it is located within Sewer Benefit Areas E. The equivalent dwelling units within Sewer Benefit Area E are proposed to connect to the existing 24-inch gravity sewer in EI Camino Real (City designation: Reach SAHTIG of the South Agua Hedionda Sewer Interceptor). Proposed Sewer System All of the Fox-Miller project will sewer to the existing 24-inch South AguaHedionda Interceptor Sewer Reach SAHTIG. This gravity sewer is located in EI Camino Real north of the intersection with Rancho Carlsbad Drive/Jackspar Drive. The connection to the existing 24-inch sewer interceptor will be through the existing 8-inch gravity sewer extending from Fermi Court into EI Camino Real and northwest in EI Camino Real to the 24-inch interceptor. Capacity is available in the 24-inch South Agua Hedionda Interceptor Sewer since all of the EDUs within Sewer Benefit Area E have been accounted for in the City of Carlsbad sewer study titled, "Updated Fee Study Report for Sewer Benefit Areas C, D, E, and F (South Agua Hedionda Interceptor Sewer)." All the ED Us connecting to the 24-inch gravity sewer will be subject to paying 'the Sewer Benefit Area Fee for Zone E. DEXTER WILSON ENGINEERING, INC. PAGE 4 I I I I I I I I I I I I I I I I I I I Bob Ladwig February 5, 2004 Capacity in the existing 8-inch gravity sewer extending from Fermi Court to the 24-inch interceptor is the primary subject of this offsite sewer study. Analysis and Results This report prepared an analysis of the existing 8-inch sewer line from the proposed point of connection by the Fox-Miller project in Salk Avenue to the 8-inch sewer line's connection to the 24-inch South Agua Hedionda Trunk Sewer. This analysis was done to determine if sufficient capacity exists in this gravity sewer line for the additional EDUs generated by the Fox-Miller project, as well as for ultimate buildout of the serVICe area. There are four distinct development areas which generate or will generate sewage flow into the existing 8-inch gravity sewer in Fermi Court and EI Camino Real. These include the following: 1. 2. 3. The proposed Fox-Miller project. The existing industrial development along Salk Avenue and Fermi Oourt. The existing single family dwelling units in the Camino Hills development. 4. The future development of the approximately 10 acres of land west ofEI Camino Real south of Camino Hills Drive. The proposed Fox-Miller project has a buildout projection of 128.2 EDUs. The existing industrial development along Salk Avenue and Fermi Court is conservatively estimated to include 228.1 EDUs. This number of ED Us is based upon a gross acreage of 51 acres. Using this acreage and the factors of 30 percent b1:lilding coverage, and 60 percent warehouse and 40 percent office results in the estimated 228.1 EDUs. DEXTER WILSON ENGINEERING, INC. PAGE 5 I I I I I I I I I I I I I I I I I I I Bob Ladwig February 5, 2004 The Camino Hills single family residential development include 112 EDU s. The empty lot between EI Camino Real and the Camino Hills residential area is shown in the City of Carlsbad General Plan to be low density residential, zero to four dwelling units per " " acre. This results in a maximum expected dwelling units of 40 EDUs. Appendix A presents the results of the computer "model of the existing sewer lip.e including existing flows plus those generated by the Fox-Miller project. Figure 1 at the back of this report shows the computer model input data including the number of buildout EDUs connected to the existing 8-inch gravity sewer. Figure 1 also shows the location at which the buildout EDUs were modeled to enter the existing sewer system. Under existing flows plus Fox-Miller projected flow conditions, all reaches of the 8-inch gravity sewer are flowing less than half full. The mini~um slope in the 8-inch line is 0.4 percent; in these reaches of sewer, with ultimate flow from the three of the four" potential developments, the depth-to-diameter ratio is 0.44. Appendix B presents the results of the analysis where the future potential 40 EDUs from the vacant land along El Camino Real are included in the 8-inch sewer system. Under this scenario, all reaches of the existing 8-inch gravity sewer are flowing less than half full; the maximum depth-to-diameter ratio in any reach is 0.47. Therefore, all reaches of the 8-inch gravity sewer downstream of the Fox-Miller project have sufficient capacity to accommodate anticipated sewer flows from the Fox-Miller project under ultimate sewer flow conditions. Recommendations The following recommendations and conclusions are made based on the sewer system analyses performed for the Fox-Miller project. 1. The Fox-Miller project is within the South Agua Hediqnda Sewer Drainage Basin and will contribute flow to the South Agua Hedionda Interceptor Sewer system. DEXTER WILSON ENGINEERING. INC. PAGE 6 I I I I I I I I I I I I I I I I I I Bob Ladwig February 5, 2004 2. 3. 4. 5. 6. The Fox-Miller project is within Sewer Benefit Area E. The proposed development within the Fox-Miller project will pay the Sewer Benefit Area Fee for Zone E. There is sufficient capacity in the existing 8-inch gravity sewer downstream of the Fox-Miller project and upstream of the 24-inch South Agua Hedionda Trunk Sewer 1 Gin EI Camino Real to accommodate the ultimate projected sewer flows from the service area. Within Sewer Benefit Area E, the exis~ing 24-inch SAHTIG gravity sewer line in EI Camino Real has been sized to accommodate all the EDUs proposed by the" Fox-Miller project. The Fox-Miller project must extend the existing 8-inch gravity sewer in Salk Avenue into the proposed project to provide sewer service to the four proposed industrial park lots. Thank you for the opportunity to prepare this report. If you have any questions on the enclosed information, please do not hesitate to call. AO:ng Appendices DEXTER WILSON ENGINEERING, INC. PAGE 7 I I I I I I I I I, I I I I I I I I I I APPENDIX A SEWER SYSTEM ANALYSIS FOR EXISTING FLOWS PLUS THE FOX-MILLER PROJECT For Access Manhole Number designations, EDU inputs, and for sewer system layout refer to Figure 1 within the report. I I I I I I I I I I I I I I I I I I I· FDx-Hiller D1fsite Sewer Analysis -Initi31 Condition 37 .ID0ij~~0 36 ,~i14i}0~ .., ! b .~12b~0 ,g20~00 ijF"~ i:;';:;j4 .q;.t.i~~~ 7-; .... \/ 3b 7 5 ij :~13 =~13 il.,7 ::U.!. .... i .Sis Diam ,-, o B ---Design CritEria --- ~ .:n !JllJ .b .~ ro!. " • .!. .8 ; .0 .., f .., f 4.9 4.7 ++++++++++++++*+++++++++++++-:-+++ END OF AREA ++++++7++++++++++i-++++-:-·:--++++++++ PAGE i F e.b. S 2-(,H ¥ I ::r,b 1'1/-00/ f/f.e.. 7'frOQ! 13 II SE~ER ANALYSIS UNiTS I I I I I I I I I I I I I I I I I I DISTANCE FEET DIANETER FLuf1 INCHES j~HJD ELEVATiut; iiREA r::'Cf ACRES I I I I I I I I I I I I I I I I I I I ~anhulE .,. I • 't " .' ., f 9~ 1~~ 2/ 5/84 9:11~i5 otGI L:ufitri.huted ;,_: -.:. f~.iH:' Ilfea FID~¥ S[mr!:2 3~~ =~~ ,;}3 ~~~ .\i.l~ ~2 t;;r;. f~€J ;:;r:!: a~U '!,PfJ .i.W .00 ~~:L iiri ;:;~~ :~3 ,iHJ ~t!~ I I I I I I I I I I I I I I I I I I I 7 Hi Diam " () Ca~;;­ ;.:i ti Ii .29 Sl .44 44 44 .;. + + + + + :-+ f + ;. + + ;. T + ;. + -} + ;. ;. + + ;. ;. i-;. + Ef~D DF AREA +;. + + ;-;. ;. + ;. ;. + + + + + + + ;. '+ ;. + ;. ;. ;. + f ;. ;. + _J I I I I I I I I I I I I I I I I I I I APPENDIXB SEWER SYSTEM ANALYSIS FOR ULTIMATE BUILDOUT SEWER FLOWS For Access Manhole Number designations, EDU inputs, and for sewer system layout refer to Figure 1 within the report. I I I I I I I I I I I I I I 1 I- 7:"7i I ~ Blb 7~ 37 36 7:: "';'$.' 3·4 -;-.. ' J.J. 1 J"'to " 9 i1 () 7 -~ , 04~2i~~ ~2~~~0 ~04~1~fi , ~~4J~0 ~~4~~~ ~~~~~~ ;H 52~~ ;-til. ~18S~~t , , , ft6i~t~ 03B4fJ~ , ~i26~Z ~2~~~~: ~-~21~~~ a:~ q~ 37 ... \;:} 3~ ~~ 7;7-... '''': , "' ~ " '1 e ., f ;J " .... 1,2 f'~.b. S, U01 JDh. ril -()()/ (/6-: 71loM U. " .... I I I I I I I I I I I I I I I I I I DIST{;;4CE fii.';':':i""':'i'. iliiiriCiCi\ FEET INCHES FLOW ELEVATION AREA I'lBn FEET ;,.~;.:;: Ht..f\i:~ '-' I I I I I I. I I I I I I I I I I I I I 7 34 PAGE i Contriblite~ Point .H. __ _ Hi't:'~ .:.. I I I I I I I I I I I I I I I I I I I SEWER ANfilVSIS SANITARY LOAD APPLIC:1TIDNS Fo~-Miller Dffslte SewEr Analysis -BuildDUI Cunditiun MH Slope Up Down city =73 57 fii .c.! .11 Ii .ii 3.7 '7 ; · ...... 0 0" ~ .. ' I! 2 .. 1 P;iGE 2 .2B ~22 ,47 .if7 .28 + + + + of-+ 'f T + ;. 4-+ f + + + + + + + T. + + ,. + + ,. + + END DF AREA +,. + + + + {-+ + + + t + + + T + + .f T ;. + + + + + + + + ---- CJII • ~. I\) I ..... G ~ ITI I ~ 0 I c C/J • b »-z ~ ~ C")Zc C")d~ ~ C") ITI CD ITI U>U>ITI Z U> U>-<:::o (j) U> ::r:~ ::r: OITl~ (j) 0 I~ ~ I ITI ITI ITI ~C =< Z c »C/J c U> 3:: "(j) .". ~ ttl <5 ITI ITI=E ITI :::0 z-:::0 Z (j). ~ z SCAL£: I" = 500' --------- /" , .. .. ~ ' .' ---... - '" FIGURE 1 FOX-MILLER PROJECT OFFSITE SEWER ANALYSIS -