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HomeMy WebLinkAbout3190; Rancho Santa Fe Rd Improvements Sewer Report; Rancho Santa Fe Rd Improvements Sewer Report; 1990-10-25 (2)3}f0 SAMITARY SEWER REPORT RANCHO SAMTA FE ROAO IMPROVEMENTS ASSESSMENT DISTRICT 90-01 VALLECITOS WATER DISTRICT CARLSBAD, CALIFORNIA OCTOBER 25, 1990 PREPARED FOR: FIELDSTONE/LA COSTA ASSOCIATES LIMITED PARTNERSHIP PREPARED BY: PROJECT DESIGN CONSULTANTS 1010 SECOND AVENUE, SUITE 500 SAN DIEGO, CALIFORNIA 92101 (619) 235-6471 FOR lot PLAN CHECK SUBMITTAL Brad D. Smith, P.E. RCE 46221 Registration Expires 12/31/90 PREPARED BY: CHECKED BY: T.W.TW TABLE OF CONTENTS Page Title Page 1 Table of Contents 2 Introduction 3 Description of Study Area 3 Existing Sanitary Sewer System 5 Proposed Sanitary Sewer Improvements 5 Analysis and Results 6 Conclusion 7 LIST OF FIGURES AND TABLES Figure 1 - Project Location Map 4 Figure 2 - Exhibit 'B' - Proposed Land Use and 8" Sanitary Sewer Main 9 Figure 3 - Table of Recommended Unit Wastewater Flows - Vallecitos Water District .... 13 Figure 4 - Peak Wet Weather Curve - Vallecitos Water District 14 Figure 5 - Tabular Values of Hydraulic Elements of Pipe (ASCE M&R No. 37/WPCF MOP 9) 15 Figure 6 - Nomograph for Manning Formula for Pipe Flow (ASCE M&R No. 37/WPCF MOP 9) 16 Figure 7 - Hydraulic Elements Graph for Circular Sewers 17 ATTACHMENTS Exhibit 'A' - Proposed Relocation of Existing Utilities INTRODUCTION The intent of this report has two functions: (1) To determine the size of the sanitary sewer main required to be installed in the proposed realignment of Rancho Santa Fe Road within the Vallecitos Water District jurisdiction as per the City of Carlsbad and Vallecitos Water District Standards, and (2) Show the proposed relocation of existing sanitary sewer lines in the area of Melrose Avenue and Rancho Santa Fe Road. The proposed extension and size of municipal sanitary sewer was based on the City of Carlsbad's design manual for Public Works improvements, dated 1987, Vallecitos Water District design criteria for sanitary sewer facilities and the proposed land uses for adjacent property designated in the General Plan Amendment prepared by Project Design Consultants in conjunction with the Rancho Santa Fe Road Environmental Impact Report. Construction of this sanitary sewer system is in conjunction with the construction for the widening and realignment of Rancho Santa Fe Road between La Costa Avenue and Melrose Avenue in the City of Carlsbad and will provide sanitary sewer service for developable property adjacent to the Rancho Santa Fe Road Alignment. DESCRIPTION OF STUDY AREA Rancho Santa Fe Road is generally a north-south road which links San Marcos to Encinitas. The section of Rancho Santa Fe Road designated for improvement originates at the Rancho Santa Fe Road intersection with La Costa Avenue and North to the Melrose Avenue Melrose Drive La Costa Meadows Drive Questhaven Road PROJECT LOCATION MAP FIGURE 1 9 Ptx)ject Design Coitsultants Planning and Engineering lOtO Second At enue. Suite 500, San Diego, CA 92101 6I9 2SS-6471 FAX J.N. 738. 20 intersection, across San Marcos Creek. Refer to Figure 1, page 4. for a project location map. EXISTING SANITARY SEWER SYSTEM An 8-inch municipal sanitary sewer intersects the proposed Rancho Santa Fe Road alignment adjacent to La Costa Meadows Drive. The 8-inch sanitary sewer located in the La Costa Meadows right-of-way drains westerly by gravity across the existing Rancho Santa Fe Road alignment to a manhole intersecting an 8-inch municipal sanitary sewer main draining from, and servicing development to the north. The junction of these lines drains westerly to the Meadowlark Treatment Plant and lift station via a 10-inch gravity sewer. Other sanitary sewer facilities exist in this area and will be relocated as a result of the Rancho Santa Fe Road improvement. Refer to the attached existing utilities Exhibit 'A' at the end of this report for more detailed delineations of existing utilities as determined from available records and the proposed relocation within the realignment of Rancho Santa Fe Road. PROPOSED SANITARY SEWER IMPROVEMENTS Approximately 2,000 lineal feet of proposed 8-inch sanitary sewer will be installed within the right-of-way of the proposed Rancho Santa Fe Road alignment. A connection to the existing sanitary sewer system is proposed at the intersection of La Costa Meadows Drive with the proposed realignment of Rancho Santa Fe Road. Refer to Exhibit 'B* for the location of the proposed 8-inch sanitary sewer main. An existing 8-inch sanitary sewer, 10-inch sanitary sewer force main, 6-inch sanitary sewer force main, and 12-inch sanitary sewer force main will be relocated within the proposed intersection of Melrose Avenue with Rancho Santa Fe Road. The existing 10-inch sanitary sewer force main will be upgraded in this area to an 18-inch size and will have a capacity to handle five (5) million gallons per day (MGD) as requested by Vallecitos Water District. Refer to Exhibit 'A' at the end of this report for the location of the proposed connection to the existing system and the proposed relocation of existing facilities. ANALYSIS AND RESULTS Determination of the size of the proposed sanitary sewer main was based on the City of Carlsbad's Design Manual for Public Works Improvements, dated 1987, Vallecitos Water District criteria and a preliminary land use exhibit for adjacent property prepared by Project Design Consultants. Refer to Exhibit 'B' for a portion of the preliminary land use exhibit prepared by Project Design Consultants. Design Criteria: 1. Vallecitos Water District - Design Requirements a. Design Flow - The design flow used for calculation purposes is peak wet weather flow. (Refer to Figure 4, page 12, graph of Wastewater Wet Weather Peak Factors). b. Capacity of gravity sewers detennined from Manning Formula. c. Pipes are sized to flow one-half full for diameters less than 12" (inches). d. Minimum velocity = 2 feet per second. e. Maximum velocity = 10 feet per second. City of Carlsbad - Design Rec[uirements a. (l-A-8) for diameters 10 inches and smaller, depth of peak flow = 1/2 the diameter. b. (1-D-l) domestic demands - residential areas: 246 gal/dwelling units/day average. c. Maximum flows should be based on ratio of peak to average flow of 2.5 unless otherwise approved by City Engineer. CONCLUSION We can conclude from this study that an 8-inch sanitary sewer main meets the requirements for design standards in the City of Carlsbad and the Vallecitos Water District. The proposed 8-inch sanitary sewer should be installed and connected to the existing sewer system as presented in this report in conjunction with the construction of the realignment of Rancho Santa Fe Road to prevent future demolition of Rancho Santa Fe Road and to provide sanitary sewer service to abutting developable property. We anticipate the proposed sanitary sewer main will remain dry for approximately 5 to 10 years as no Tentative Maps for the associated developable area have been submitted for review at this time. A study was not done to determine the adequacy of the existing 8- inch or 10-inch sewer to the Meadowlark Treatment Plant. The upgrading of this system will be done by developers needing sewer use prior to the Fieldstone/La Costa project. If these lines have not been upgraded prior to Fieldstone filing for a Tentative Map, the study and design may be made a condition of their Final Map approval. The relocation of existing utilities has been designed in accordance to the City of Carlsbad and Vallecitos Water District standards. Refer to Rancho Santa Fe Road improvement plans for the detailed design of these facilities. ••'^ t ' •'. .wt*^/" / ^•»- 'tV 1 frfT^^TTiV-. .. 5 WC^MED 18'' BMj/mT-^EWER ROAD PROPOSED LAND DESIGNATIONS / PROPOSED SANITARY TRUNKfSEWER ( EXIST.'i AND m WI^ECIMIW- T.^mlmreEWER EmBM'A DETAILS EYIdT ^ BIT W - ^-v I • - "^j^'^^^'^^KJw v^;^^^ '^^^ ^ ^ miOOWLARK TREATMENT PLANT \ • •-m 400 1' tllliii'V^/;. 11 l17:g^^AC. x^ .O DU/AC • I III 4iSi^;x,3.2DU/AC.i ±= 144 DU ^ ^ . ^\ PROPOSED S" KC. S/f^l 1 + > A ^-^^ !>i.i,r*;^ipir-^ ff r. J^.2bu/Ac:/; I,. /1,' • ^1' miLECITOS^^S^^ ' WATE^^DISmotK^ =UHi€UeADI/(^'-^^-- ^^^EWER-DI^/CT^j>^r: IMP ..1; •'r">A;.c- • TPf/V/Y Vs '1 yr(F5if/i-( ,y ,saut ^•^'^^''•r:,^^J(p PtvjectDesigJz Consultants - : / "^^v - • I"'" ^""'"l .^' tnue. Suite '.tXI. Sail Oienn mini -.i n • - j ' .. " • • «'9-.?.)S-r-.<r/ M.Y^H-O.HSl •I !);• /> J.N. 738.fi? < << o = =) ooo ie..4 Ac'*» X ^eZQo/Ac. ^ 56•'^i DO'S o,o£57(^ ^6o^ -f-o (f'i^> /v^il/rf, /^'"^y r- • 6/ry c?/^ eA£63^/^p ceirs'e/A i _\0 - <<< OOO 3AU »rAi2Y %vo-^(2. HPviN cesM t pCjK ctlC4# ,007 — 'WV I v7HO*6.<-^ V 7 A/; _ ll - /a^e^/y^a^r? 7^? dif? /0 " Sar/^/a'^Y ^^^^^ -Th^ pw?oee<^ force^^^^in shall he de^i^'yieA Cfrai^/-^y s^rv/^^ /^aufhcf Cide^^uah 5 X 1.55 Cf^/ = 7.7s '^'='5 y^p /4^^ ^ /4^//' I/, ^3^^^ ^ 4-."^%. >^ oi^ 1 L'. .-riL-L'.-'. 1 1 • Fiqu^X 3 TABLE 9-2 RECOMMENDED UNIT WASTEWATER FUCWS Land Use Category RecCTrrmended Unit Water Deniands (gpd/ac) Measured Wastewater Flovre (gpd/ac) Racarmenclod Unit"Wastewater FlCTrfS. (gpd/ac) 1-Hillside Res. 0.25-0.5 du/ac 1,000 _ _ _ 400 "(0.125-1.0 du/ac) ^vOOO • _ _ _ 3-Res. ( 1-2 du/ac) 1,500 - - -400 4-Res. ( 2-4 du/ac) 1,750 800 800 5-Res. ( 4-6 du/ac) 2,000 - - -.:1,250, 6-Res. ( 4-8 du/ac) 2,000 _ _ _ 1,550 7-Res, ( 8-12 du/ac) 2,250 ~ ", ' 1,900 8-Res. ( 12-15 du/ac) 3,750 3,000 3,000 9-Ras. ( 15-20 du/ac) 3,750 - - -3,000 10-Res. (20-30 du/ac) 4,000 - - -3,700 ll-Corm\. 1,500 1,500 " 1,200 12-Light Ind. 1,500 1,200 13-Indust. 2,000 . — -1,800 14-Office Prof. 1,500 - - -1,800 15-Schools & Public Facilities 1,250 - - -820 16-Palomar College 2,250 2,075 17-San Marcos Stat© University 2,250 - - -2,075 18-Parks 1,500 - — — 300 \ I C ^ 3 E- < Hi2 9- «> --- Peak Wet Weather Curve I SS/Ji^ij S';i" •.-: VrV:':^ \ I •! '• liiiillil ;;il|||fii: iiiiiiii ^lliiiilll iiilillit SiSiill \ •;liiiilifl: fiilliiil - .-. OJ 0.6 0.7 0.8 Average Dry Weather Flow 0.9 1.0 1.1 1.2 1.3 I AVEUS . • ; • IIYDRAUr,ICS OF SEWRRS 97 TABLE XVI.—Tabular Values of Hydraulic Elements of Pipes (n constant) 1.000 • 800 600 -t. 500 -r 400 -J- 300 200 - 100 80 60 50 40 - 1= R - 1.0 0.8 0.6 0.5 0.4 .400 ,000 1,000 800 600 500 400 300 200 100 80 60 50 "g o 40 — 20 ~ 10 DO 8 5 6 S 5 - r 2 1.0 0.8 0.6 0.5 0.4 HYDRAULICS OF SEWERS 96 - 84 - 72 • 60 - a 54 •g 4a 9- 33 Q. 30 0 27 u 24 1 21 S 18 12- 10 0.13 0.2 FIGURE 22.: 0 004 -F 0 5 0.005- 0.C06-: 0.007 ^ 0.008 - 0.009- 0.01+ 0.8 ^0.6 - 0.7 0.02- 0.04 - - rO.lO 0.05-1- O.QE 0.05 «-"' -0.04 0 08 0.09 .-0.9 '-- 1.0 0.03" .02 0.0,15.^3 ;0.010 \ '0.008 If- 0.4 0.54 0.6- C.7 0.8 0.9 1.0^- 8 '.'T 9 10 81 0.4 0.3 rO.l r 0.08 0.06 - 0.05 -0.04 0.03 0.02 0.01 0.008 0.0O6 0.005 0.004 0.003 0.002 I!' CO r 0.001 P 0.0008 0.0006 0.0005 0.0004 0.0003 0.0002 0.0001 0.00008 0.00006 0.00005 0.0OOO4 0.00003 0.00001 0.000008 0.000006 ; 0.000005 • 0.000004 -Alignment churl for Manning formula for pipe flow. in which the nomenclaturo is bnsically the same as that used in Equation 13 and C is a coefficient related to roughness. The formula is used widely for pressure-conduit or pipe flow, although it is equally applicable to open-channel conditions. Published values for C have come largely from pipe-flow experiments, while many of the reported n values are from open-channel flow tests. The Hazen-Williams HYDRAULICS OF SEWERS 87 This 'raulic large pion is I D/k I 60-in. ie n = ay be ^ubject Highly 3 pipe Ih con- results does [radius even ircular work lof the annels. ^puting .1 that that effect llefined corn- cover liannels (2). A |nge in other ects of loblems Iful to 24 is a Iniform Com- ly Fair Values of -i- and i I 1.0 1.2 V 1.4 1.6 1.8 2.0 l.i. i.'^ 1 1 1 1 n, / variable with depth 4 — i. J - / > -X—/-—>.—^- n,i constant — -—Independent of n,^ r / / / / U \— 1 — V f- Darcy-W Friction eisbach actor,/ • / i ^ / ; -U. / 'A y / 'I 5 .Discharge, A Q > r. Hydri radiu ulic 5 \ Manr ing's n y • / «" / 4 > \ Velo 1 1 «ity,V.^ 3 '^Ar< a,A • t . •v. :c A ( 1K r _ 17 3.8 0.9 ' _ __x 1.0 ^' 1.1 X 1.2 1. Hydraulic elements ^. ^. '"ST V,' Q," A, FIGURE 24.—H> ilraulic-elemenls graph for circular sewers. et al (22). Graphs for sewers of other than circular cross section may be developed by the same general method. Most of the hydraulic-elements graphs in common use have been pre- pared on the assumption that the Manning n does not change with the depth of flow for the particular conduit shape. Nonetheless, many ex- perimenters have observed a variation of n with depth of flow. The ex- periments of Wilcox (23) and of Yarnell and Woodward (24) show that the value of n for a pipe flowing partly full is greater than for the full pipe; and the average n values for 824 experiments are as indicated by the curve through the points marked by circles in Figure 24. A similar curve for the Darcy-Weisbach fraction factor / also is shown in the same figure. The relation between the two friction coefficients is n,-\R,) \f,) which is similar to Equation 19. The points in Figure 24 marked by triangles and x's were estimated from the measurements made by Johnson (25) in large Louisville, Ky., sewers flowing partly full. Since individual values of //// in the experi- ments of Wilcox and of Yarnell and Woodward varied widely from the average for a particular value of d/D, the reliability of the averages used in Figure 24 may be questioned. Tests by Schmidt (26) on a large 21 -/7 -