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HomeMy WebLinkAbout1988-04 r COUNTY SANITATION DISTRICTS NOS. 6, 7 and 14 OF r ORANGE COUNTY, CALIFORNIA r Revised Project Report for r Joint Sewage Conveyance Facilities to Serve Districts Nos. 6, 7, and 14 r Contract No. 14-1 r r April1988 r Prepared by r Boyle Engineering Corporation P.O. Hex 3030 Newport Bp.aah,CA 92656-902D QROFESS/0N ` �O EOGENp q! ye4���Q sTo �✓ Telex 685561 yF W C-0mg4 p * P. 6130/89 >r r sr CIVIL �Q 9rFOF CAV%0 REVISED PROTECT REPORT SUMMARY Subsequent to issuance of this project report the Districts r have revised the sizing criteria for the gravity trunk sewers of the project to limit the peak flow depth to pipe diameter ratio (D/d) to 0.75 for all sizes greater than 21-inch diameter in response to the Irvine Ranch Water Districts' December 16, 1987 letter request. The effect of this criteria revision is to increase the gravity portion of the Baker-Gisler Interceptor from the Santa Ana River to the terminus of the Baker Street Force Main at the Santa Ana-Delhi Channel from 84- and 78-inch diameter to 90- and 81-inch diameter, respectively. r The result of the pipe size increase of the Baker-Gisler Interceptor is an increase in the estimated construction cost of this facility. The Districts' staff has indicated the additional capacity freeboard should be allocated to District No. 14, the requestor for the criteria revision. Consequently, the average flow capacity determination has been revised in the following manner: r 1. The upsized pipeline's peak flow capacity is calculated at a D/d = 0.92. 2. The pipeline's average flow capacity is calculated from the peak-to-average flow relationship included on page II-1 of the project report using the peak flow capacity from step 1. 3. The average flow is allocated by maintaining the same average flow capacity for Districts Nos. 6 and 7 as r shown on Table 1 of the project report (page II-2) and allocating the remainder to District No. 14. Table 1A on the following page extends Table 1 of the project report to reflect the revised capacity allocation. r Table 8A summarizes the revised estimated construction costs of the conveyance facilities for the upsized Baker-Gisler Interceptor and allocates the construction costs in accordance with the prorated ownership of the participating Districts r shown in Table 1A. The text, tables, or figures of this project report that follows have not been revised to reflect the above. The conclusions of the report remain, except as described above. It should be noted the major revisions to the project report would be to replace the following Tables lA and 8A for Tables 1 and 8 of the report and revise the profile on Sheets 1 through 4 of Figure 4 at the back of the report to reflect the 90- and 81-inch pipe sizes. r r 1 t 1 t [ [ [ I ! ! I [ [ E l l 1 t ! TABLE IA DESIGN PLOW AND CAPACITY ALLOCATION FOR JOINT GUIDE CONVEYANCE FICILTISS To SERVE DISTRICTS NOS. 6, 7, AND 14 ____________________________________________________________________________________________________________________________________________________________________________________ Facility Beach Pipe Projected Average flow egd/(% of total) Design Peak Pipe Capacity (egd) Average Flop Capacity agd/(% of total) _____-----____--- ------------------- Size Slope ----------___-_----------" - Floe (agd) -------(1)(2)------- -----------------"'---------------- from To CSD No. 6 CSD No. 7 CSD go. 14 Total Peak Flow Ave. Flow CSD No. 6 CSD No. 7 CSD No. 14 ----------------- ------------------ ----- ------ ---------- ------------- - ------ ----------- -------- --------- ------------- ------------- ------'-_- BANER-GISLER INTERCEPTOR Reclamation Plant 1 Fairview Road 90' .0004 10.30 (14.6%) 16.88 (23.9%) 43.5 (61.5%) 70.68 89.33 106.7 85.74 10.30 (12.01) 16.88 (19.7%) 58.57 (6B.3%) Fairview Road Neadosa Drive 81' .0005 .68 (1.1%) 16.88 (27.6%) 43.4 (71.2%) 60.96 77.97 90.1 71.34 .68 (0.9%) 16.88 (23.7%) 53.76 (75.4%) Nendoaa Drive S.A.-Delbi Channel 81' .6005 -- 16.88 (20.0%) 43.5 (72.0%) 60.38 77.28 90.1 71.34 -- 16.88 (23.7%) 54.44 (76.3%) BANES STREET FORCE RAIN -- 16.88 (28.0%) 43.5 (72.0%) 60.38 77.28 FAIRVIEN ROAD RELIEF INTERCEPTOR Baker Street Village Nay 9.61 -- -- 9.61 14.25 9.81 -- -- Village Nay fair Drive 6.28 -- -- 6.28 9.63 6.28 -- -- Fair Drive Nilson Street 2.12 -- -- 2.12 3.55 2.12 -- -- --------------------------------------------------------------_----------------------------------"'--------------------------------------------------------------__------ 1) Peak flow capacity based on flow depth to disaster (d/D) ratio = 0.92. 2) Average flop capcity based on relationship Qpeak = 1.84(Qave) raised to the 0.92, Q in cfe. r TABLE 8A COONT➢ SANITATION DISTRICTS NO 6, 7, AND 14 SENAGE CONVEYANCE FACILITIES r PBBLIMINAR➢ CONSTRUCTION COST ESTIMATE ________________________________________________________________________________________________________________________________ r COST ALLOCATION --------------------------------------- it" Description 0uanity gait Suit Price Total Cost CSD 6 CAR 7 CID 14 ----------------------------------------------- ------- ---- -----•-•---- BAEIB-GISLIB INTERCEPTOR 1 90' E.C.P. Sever 13,550 L.P. $710 $9,890,000 $1.190,000 $1,950.000 $6,750,000 2 81' R.C.P. Sever 1,980 L.P. 675 1,340,600 10,090 320,000 1,010,000 (Fairview Rd. to Benicia St.) 3 81' R.C.P. Sever 41890 L.P. 645 3,150,000 750,000 2,400,000 (Boggess St. to Delhi Channel) 4 118' Jacked Casing/Tunnel-Bristol St. 96 L.F. 2,270 220,000 50,000 170,000 5 118' Jacked Casing/Tunnel-Fairview Rd. 120 L.P. 2,270 270,000 60,000 2001000 6 132' Jacked Caeiog/Tunnel-Harbor Blvd. 114 L.F. 21550 290,000 30,000 60,000 200,000 7 Junction Structure-Pairviev and Baker t L.S. 50,000 50,000 10,000 10,000 30,000 8 Siphon-Santa Ana liver 1 L.S. 400,000 40010eo 5D,000 80,000 270,000 9 Siphon-Greenville/Banning Channel 1 L.S. 550,000 550,060 7D,000 110,000 380,000 10 84' Manhole 300 V.P. 700 210,000 3D,000 40,000 140,000 (Treatment Plant No. 1 to Pairviev Rd.) 11 84' Manhole 40 V.F. 700 3D,000 10,000 20.000 (Fairvlev Bd. to Meodoaa St.) 12 84' Manhole 60 V.F. 700 40,000 10,000 30,000 (Retinas St. to Delhi Channel ------------ ----------- --------- ------------' r SUBTOTAL 816,44D,000 $1,390,000 $3,450,000 $11,600.000 BAKER STREET FORCE MAIN I Tvo 42' D.I.P. Sever (Double Barrel) 9,400 L.P. 500 417001000 1,320,000 3,380,000 2 Tvo 66' Jacked Casing/Tunnel-Sain St. 90 L.P. 2,350 210,000 60,000 150,000 3 Tie 66' Jacked Caeing/Tunnel-San Diego Ivy. 250 L.P. 2.350 590,000 170,000 420,000 4 Tvo 66' Jacked Caeing/Tueoel-Delhi Channel 70 L.F. 2,350 180,000 40,000 120,000 5 Junction Structure (Kith Interceptor) I L.S. 20,000 20,000 10,000 10,000 ------------ ----------- --------••- ............. SUBTOTAL $5,600,000 $1,600,000 $4,080,000 r PRISMS ROAD IILISF INTERCEPTOR r 1 33' T.C.P. Saver 000 L.P. 280 220,000 220,000 2 27' T.C.P. Sever 5,30D L.P. 240 1,270,DCO 1,270,000 3 21' T.C.P. Sever 2,700 L.I. 190 510,000 510,000 4 66' Jacked Casing/Tunnel-Baker St. 90 L.P. 1.140 100,00D 100,000 r 5 54' Jacked Caeing/Tuatel-Fair Dr, 75 L.P. 700 50,00D 50,000 6 Manhole 72' 143 V.I. 650 90,000 90,000 7 Whole 90' 78 V.P. 650 WORD 50,000 ------------ ----------- ----------- --•---------- SOBTOTAL $2.290,000 $2,290,000 TOTAL $24,410,000 13,980,010 $5,050,000 $15,680,000 r ................................................................................................................................ r r r r COUNTY SANITATION DISTRICTS NOS. 6, 7, AND 14 r OF ORANGE COUNTY, CALIFORNIA Ir r PROJECT REPORT for r JOINT SEWAGE CONVEYANCE FACILITIES TO SERVE DISTRICTS NOS. 6, 7, AND 14 CONTRACT NO. 14-1 r DoLile r r August 1987 Encyncerinq Cornoration P.O. Sex 3030 Prepared by r BOYLE ENGINEERING CORPORATION Telex 68656, QRGfESS10N O���Q EtlGENf sT2< y4/ C-017714 ^' r W A EXP. 6130/89E. ► r A CIO- 4'FOF Ca1MQe J TABLE OF CONTENTS Section Page r PREFACE AND SUMMARY MATRIX i I INTRODUCTION I-1 ti A. BACKGROUND I-1 B. PURPOSE OF PRELIMINARY ENGINEERING DESIGN I-1 C. PROPOSED PROJECT I-2 J II DESIGN CRITERIA II-1 w A. PROJECTED FLOWS AND OWNERSHIP II-1 1. Design Flows and Ownership II-1 2. Initial and Ultimate Projected Flows II-1 B. GRAVITY TRUNK SEWER DESIGN II-3 J 1. Sizing II-3 2. Pipe Materials II-3 3. Loading II-4 a 4. Manholes and Appurtenances II-4 C. FORCE MAIN II-4 r 1. Sizing II-4 2. Pipe Material II-7 r D. SIPHON DESIGN II-8 1. Number and Size of Barrels II-8 2. Depth Below the Channel Bed II-9 J 3. Access Structures II-9 4. Air Vent II-9 III ROUTE ANALYSIS III-1 A. ROUTE ALTERNATIVES III-1 r 1. Main Street Pump Station to Baker Street and College Avenue III-1 2. Baker Street and College Avenue to J Gisler Avenue and Washington Avenue III-3 3 . Gisler Avenue and Washington Avenue to Reclamation Plant No. 1 III-4 4. Fairview Relief Interceptor - Fairview r Road from Wilson Street to Baker Street III-5 Contents - 1 r TABLE OF CONTENTS - Continued r Section Page r B. COST COMPARISON III-5 C. ANALYSIS AND SELECTION III-6 r 1. Main Street Pump Station to Baker Street and College Avenue III-6 2. Baker Street and College Avenue to Gisler Avenue and Washington Avenue III-8 3. Gisler Avenue and Washington Avenue to Reclamation Plant No. 1 III-10 4. Fairview Road from Wilson Street to r Baker Street III-10 IV ALIGNMENT AND PROFILE ALONG RECOMMENDED ROUTE IV-1 A. ALIGNMENT IV-1 B. PROFILE IV-2 e1 1. Gravity Interceptors IV-2 2. Force Main IV-2 C. COMMUNITY IMPACT IV-4 1. Traffic Control IV-5 2. Schools IV-5 r 3. Commercial IV-6 4. Industrial Areas IV-7 5. Residential Development IV-7 6. Churches IV-8 r 7. Other Segments IV-8 D. SANTA ANA RIVER CROSSING IV-8 r E. RIGHT-OF-WAY IV-8 V REGULATORY AGENCIES V-1 W A. GENERAL V-1 B. CITY OF COSTA MESA V-1 C. ORANGE COUNTY ENVIRONMENTAL MANAGEMENT r AGENCY (EMA) V-2 D. CALTRANS V-2 E. DIVISION OF INDUSTRIAL SAFETY (DIS) V-2 F. REGIONAL WATER QUALITY CONTROL BOARD (RWQCB) V-2 r G. STATE DEPARTMENT OF FISH AND GAME V-3 H. COORDINATION WITH STREET IMPROVEMENTS V-3 VI CONSTRUCTION PROCEDURES VI-1 A. EARTHWORK VI-1 B. REMOVAL AND RESURFACING OF STREET r PAVEMENT AND SURFACES VI-2 Contents - 2 r r TABLE OF CONTENTS - Continued Section Page -- C. UTILITY CROSSINGS VI-2 D. TRAFFIC CONTROL PLAN CONCEPT VI-3 VII PROJECT SCHEDULE VIZ-1 r A. TARGET DATES VII-1 B. CONTRACT LIMITS VIZ-1 1. Baker-Gisler Interceptor VII-1 2. Baker Street Force Main VII-1 3. Fairview Relief Interceptor VII-1 C. PROJECT SCHEDULES VII-2 VIII CONSTRUCTION COST ESTIMATE AND ALLOCATION VIII-1 Table 1 DESIGN FLOW FOR JOINT SEWAGE CONVEYANCE FACILITIES TO SERVE DISTRICTS NOS. 6, 7, AND 14 II-2 2 FORCE MAIN PRESENT WORTH COSTS II-5' 3 FLOW VELOCITIES IN FORCE MAIN II-7 r 4 FLOW VELOCITY IN 66-INCH SIPHON BARREL II-9 5 CONSTRUCTION COST COMPARISON OF ALTERNATIVE ROUTES III-6 6 SUMMARY OF ADVANTAGES/DISADVANTAGES FOR r ALTERNATIVE ROUTES III-12 7 ECONOMIC COMPARISON FORCE MAIN TERMINUS ALTERNATIVES IV-4 r 8 PRELIMINARY CONSTRUCTION COST ESTIMATE VIII-2 Figure Follows Page r 1 FORCE MAIN SIZE-ECONOMIC ANALYSIS II-5 2 AIR JUMPER CONCEPTS II-10 3 ALTERNATIVE ROUTES VIII-2 4 PRELIMINARY PLAN AND PROFILE (BACK POCKET) 5 PROJECT SCHEDULE VII-2 Contents - 3 r r TABLE OF CONTENTS - Continued r Section Page r C. UTILITY CROSSINGS VI-2 D. TRAFFIC CONTROL PLAN CONCEPT VI-3 �.. VII PROJECT SCHEDULE VII-1 A. TARGET DATES VII-1 B. CONTRACT LIMITS VII-1 s 1. Baker-Gisler Interceptor VII-1 2. Baker Street Force Main VII-1 ,d 3. Fairview Relief Interceptor VII-1 C. PROJECT SCHEDULES VII-2 VIII CONSTRUCTION COST ESTIMATE AND ALLOCATION VIII-1 r Table 1 DESIGN FLOW FOR JOINT SEWAGE CONVEYANCE FACILITIES TO SERVE DISTRICTS NOS. 6, 7, AND 14 II-2 2 FORCE MAIN PRESENT WORTH COSTS II-5' 3 FLOW VELOCITIES IN FORCE MAIN II-7 4 FLOW VELOCITY IN 66-INCH SIPHON BARREL II-9 ur 5 CONSTRUCTION COST COMPARISON OF ALTERNATIVE ROUTES III-6 r 6 SUMMARY OF ADVANTAGES/DISADVANTAGES FOR ALTERNATIVE ROUTES III-12 m' 7 ECONOMIC COMPARISON FORCE MAIN TERMINUS ALTERNATIVES IV-4 ,r 8 PRELIMINARY CONSTRUCTION COST ESTIMATE VIII-2 Figure Follows Page 1 FORCE MAIN SIZE-ECONOMIC ANALYSIS II-5 2 AIR JUMPER CONCEPTS II-10 3 ALTERNATIVE ROUTES VIII-2 4 PRELIMINARY PLAN AND PROFILE (BACK POCKET) _ 5 PROJECT SCHEDULE VII-2 Contents - 3 r r PREFACE AND SUMMARY w This project report for County Sanitation Districts of Orange County is the basis for final design of the Joint Sewage • Facilities to serve Districts Nos. 6, 7, and 14. As such, this report establishes the following: the recommended route; the preliminary profile for that alternative; final technical design w. criteria; requirements, such as permitting and right-of-way; project schedule; and preliminary cost estimate. Criteria that have been established include the design flows for each reach of the system, with the corresponding flow contribution of the three participating Districts, sizing criteria, and pipe material selection using the District's standards as the basis. A preliminary alignment, size, and profile for the system are presented in the eight sheets of Figure 4 contained in the pocket at the back of the report. The force main sizing and terminus location determination included 0 economic analyses considering life cycle costs and operational considerations. r A concise summary of the numerous design and construction issues investigated for each alternative route is presented in the matrix at the end of this summary. Table 6 (Page III-11) provides a quick reference for the advantages and disadvantages of each route. The routing analysis investigated three alternative routes in each of three reaches defined by common points between Reclamation Plant No. 1 and the Main Street Pump Station. The alternative routes are illustrated on Figure 3 of the report. Between the Main Street Pump Station and Fairview Road, routes following Baker Street, Paularino Avenue, or a combination of these two streets were found to be the only feasible alternatives. Paularino Avenue is narrower than Baker Street, not continuous, and the portion west of Bear Street travels through a heavily developed residential area and past an elementary school. The Baker Street route is slightly shorter and more direct, not requiring as many direction changes for the large-diameter interceptor. Although an arterial street, Baker Street is wider and able to accommodate construction while maintaining traffic. To minimize delays to traffic on this ,r heavily traveled street, construction activities will be limited during peak traffic hours to provide as much of the street for traffic as possible. r Between Fairview Road and Gisler Avenue, routes following College Street, Cinnamon Avenue, and Labrador Drive and Gibraltar Avenue were investigated. The City indicated Harbor Avenue was not a feasible alternative, in view of the recent street improvements. The College Street alternative was eliminated, since the elevation of the street surface is too low to allow a gravity sewer profile. The Cinnamon Avenue route would require many r i r r bends of the large-diameter interceptor, which would greatly s, increase the construction time along this route, resulting in significant impacts to the surrounding commercial establishments. The addition of a junction/diversion structure with the existing District No. 6 trunk sewers is necessary for this route because +' of profile conflicts. The Labrador Drive/Gibraltar Avenue route is a more direct route and has no profile conflicts with existing utilities. It will result in definite inconveniences to those residences that front the street and it will require that the construction maintain provisions for continuous access to each residence. �+ From Gisler Avenue to Reclamation Plant No. 1, the recommended route runs adjacent to a fairway in the Mesa Verde Country Club golf course, where a slight regrading along the edge of the .. fairway is proposed to provide a minimum cover for the gravity interceptor. The route turns, runs adjacent to the Greenville-Banning Flood Control, and then crosses the Santa Ana River to Plant No. 1. The two alternatives through the r residential development north of Gisler Avenue would result in significant inconveniences to the surrounding residential community, and only that paralleling the existing District No. 6 sewers would provide sufficient cover for a gravity profile. The City of Costa Mesa is the primary permitting agency, having jurisdiction over the public streets throughout most of the r project. Other permitting agencies for specific areas include the Orange County EMA for flood control channel crossings, the U.S. Army Corps of Engineers for the Santa Ana River crossing, .. and Caltrans for the three freeway crossings. The requirements of each, including traffic control and pavement replacement, will be included in the construction plans and specifications. •+� A project schedule has been developed to meet the target of placing the permanent system serving District No. 14 in operation by January 1, 1990, in accordance with the March 13, 1985, agreement with the Irvine Ranch Water District. The schedule calls for construction to begin on the Baker-Gisler Interceptor, the first of three proposed construction contracts, by July 1988. Construction of the Baker Street Force Main must begin by January .� 1989 to meet the target. The Fairview Road Relief Interceptor is shown beginning construction in March 1989. The total construction cost of the three contracts is estimated to be $23.6 million. Allocating the construction costs in proportion to the design average flow contribution, the share of the respective participating Districts is: r District No. 6 = $ 3.9 million District No. 7 = 5.5 million District No. 14 = 14.2 million $23.6 m ion r ii r Summary Matrix of Alternative Route Analysis Issues &Considerations ce C.0 QJ p0 m� V Alternative Route Q0 5 c,° 'C° m Total Cost' A. Baker Street Q Q Q $9.3M T B. Paularino Ave. Q Q • • $10.2M C. Paularino Ave./Baker St. • . $9.41VI D. College Ave. Not Feasible I E. Cinnamon Ave. Q Q • Q $4.7M F. Labrador/Gibraltar Q Q $4.611111 G. Gisler/Golf Course Q $2.2M H. Indiana Would not meet _ �a operational criteria J. Washington/California Q Q • $2.41VI *Cost totals for each route are for comparison only and do not include common items. See Table 8 (follows VIII-1)for the estimated construction cost for the selected route. Legend ❑ Acceptable Q Constraint Clear Disadvantage ❑ Not Feasible Recommended Route-Bold Type Alternative Route-Regular Type SECTION I .e INTRODUCTION "+ A. BACKGROUND The December 1982 Consolidated Master Plan of Trunk Sewer ,e Facilities identified the facilities required to serve District No. 7 and the north half of District No. 6. The May 1985 Engineers Report for the Formation of County Sanitation District No. 14 defined the conveyance facilities to serve District No. 14, which consists of a system integrated with Districts Nos. 6 and 7. This system consists of four trunk sewer facilities, shared in differing proportions with Districts Nos. 6 and 7: the Main Street Trunk Sewer, the Main Street Pump Station, the Baker Street Force Main, and the Fairview-Gisler Trunk Sewer. District No. 14 was formed in 1986 and construction of the conveyance system is proceeding. The Main Street Trunk Sewer (Contract No. 7-2C-4) , the Von Kerman Trunk Sewer (Contract No. 7-8) , and the Main Street Pump Station (Contract No. 7-7) with an interim connection to the Sunflower Interceptor were completed and placed in operation in early 1987. ^ This project report addresses the remaining Master Planned Joint Sewage Conveyance Facilities to serve Districts Nos. 6, 7, and 14. The scope of work for design of these facilities ^ has been divided into two phases: the preliminary engineering phase and the final design phase. This project report documents the preliminary engineering phase. B. PURPOSE OF PRELIMINARY ENGINEERING DESIGN This phase is intended to identify the requirements for the facilities to be designed. The preliminary engineering scope entails: 1. Review of alternatives and selection of the final pipeline routing. ,s 2. Development of the preliminary profile. 3. Establishment of final design criteria relating to sizing, materials, and appurtenances. s 4. Identification of required permits. 5. Identification of right-of-way to be acquired. 6. Development of the project schedule and construction contract limits. I-1 •r r 7. Preparation of preliminary construction cost estimate. e. S. Research of existing underground utilities and improve- ment plans. s 9. Preparation of preliminary condensed plan and profile and traffic control concept sketches. ,e The investigations of this project report will serve as the basis for preparation of the construction plans and specifi- cation in the final design phase. C. PROPOSED PROJECT py The proposed project is intended to serve two primary conveyance purposes: 1. Convey flows generated in Districts Nos. 7 and 14 from the Main Street Pump Station to Reclamation Plant No.l. 2. Provide relief to the trunk sewers serving the north half „s of District No. 6 in conveying their flows by gravity to Reclamation Plant No. 1. The project involves the construction of the following •+ facilities: 1. A force main sewer from the Main Street Pump Station to the gravity intercept system in District No. 6. 2. A gravity interceptor conveying flows from the force main and District No. 6 to Reclamation Plant No. 1. ti 3. A gravity relief interceptor in Fairview Road to provide District No. 6 with the required master plan projected e capacity. • I-2 s� r SECTION II DESIGN CRITERIA A. PROJECTED FLOWS AND OWNERSHIP 1. Design Flows and Ownership .e The Joint Sewage Conveyance Facilities, which are the subject of this project report, receive flow from Districts 6, 7, and 14 and convey it to Reclamation Plant No. 1. Flow from Districts 7 and 14 is pumped from the Main Street Pump Station. District No. 6 flows enter the gravity interceptor first at Mendoza Drive and then at .. Fairview Road. All flows from the Fairview Road Relief Interceptor are generated in District No. 6. Since preparation of the 1982 Consolidated Master Plan of Trunk Sewer Facilities report with addendum, flow projections have been updated. District No. 7 's capacity in the Von Karman Trunk Sewer is continued in these joint conveyance facilities. District No. 14 's capacity requirements are set forth in the March 13, 1987 agreement with the Irvine Ranch Water District (IRWD) . The peak flow was determined using the following CSDOC peak-to-average flow relationship: Qpeak - 1.84 (Qave. ) 0.92 Q in cfs Construction costs of these trunk sewer conveyance ,r facilities is shared on the basis of the proportion of the respective District's capacity in accordance with the March 13, 1985 agreement with the IRWD. The allocation of costs of the new facilities is prorated based upon s average flow capacities. Table 1 lists the design flow contributions by the ,. participating Districts for each facility reach. 2. Initial and Ultimate Projected Flows e" Flow build-up within the tributary service area of these sewage conveyance facilities in addition to the opera- tions of the IRWD Michelson Water Reclamation Plant will affect these facilities with regard to the amount of flow transported to Reclamation Plant No. 1. The addendum report to the 1982 Consolidated Master Plan of Trunk Sewer Facilities contained flow projections by the IRWD staff for the IRWD planning area including their projected seven-month summer period and five-month winter period variation to account for their water reclamation II-1 TABLE 1 DESIGN FLOW FOR JOINT SEWAGE CONVEYANCE FACILITIES TO SERVE DISTRICTS NOS. 6, 7, AND 14 Average Flow Design Peak Facility Reach mgd/(S of Total) Flow ______________ _______________________________________________________ ___________ From To CSD No. 6 CSD No. 7 CSD No. 14 Total (mgd) _________ _________ __________ _____ _____ BAKER-GISLER INTERCEPTOR Reclamation Plant 1 Fairview Road 10.30 (14.6%) 16.88 (23.9%) 43.5 (61.5%) 70.68 89.33 ti Fairview Road Mendoza Drive 0.68 (1.1g) 16.88 (27.6%) 43.4 (71.2%) 61.06 78.09 H i Mendoza Drive S.A.-Delhi -- 16.88 (28.0%) 43.5 (72.0%) 60.38 77.28 N Channel BAKER STREET FORCE MAIN -- -- 16.88 (28.0%) 43.5 (72.0%) 60.38 77.28 FAIRVIEW ROAD RELIEF INTERCEPTOR Baker Street Village Nay 9.61 -- __ 9.61 14.26 Village Way Fair Drive 6.28 -- -- 6.28 9.64 Fair Drive Wilson Street 2.12 __ __ 2.12 3.55 program. Using this summer/winter variation the following initial and ultimate flows have been projected: Winter Flow Summer Flow (mgd) (mgd) Facility Average Peak Average Peak INITIAL (1990) Main Street Pump Station 19.4 27.2 5.9 9.1 Baker-Gisler Interceptor 22.4 31.0 8.9 13.3 To Reclamation Plant No. 1 33.2 44.5 19.7 27.5 ULTIMATE w Main Street Pump Station 60.4 77.3 41.9 55.2 Baker-Gisler Interceptor 70.0 88.5 51.5 66.8 To Reclamation Plant No. 1 82.2 102.6 63.7 81.1 s B. GRAVITY TRUNK SEWER DESIGN s 1. Sizing Flow calculations are based on the Manning formula for ^ open channel flow with a coefficient of friction, n, = 0.013. Pipelines will be sized to limit the peak flow depth to pipe diameter ratio (D/d) to the following: sm Pipe Size (inches) DLd 8 to 18 0.50 21 to 60 0.75 > 60 0.92 s Section IV presents a preliminary profile for the gravity trunk sewer facilities. •' 2. Pipe Materials The Gisler-Baker Trunk will be comprised of 78- and 84-inch-diameter pipe and the Fairview Road Trunk will vary from 24-inch to 33-inch-diameter pipe. Keeping with the District's standards, vitrified clay pipe (V.C.P.) will be specified for sizes of 42-inch-diameter and less. ^' Low head reinforced concrete pipe (R.C.P. ) with poly- vinyl chloride (PVC) plastic liner plate will be speci- fied for sizes greater than 42 inches in diameter. A' w II-3 a r 3. Loading Since the gravity trunks are sized for open channel flow conditions, the piping will be designed to handle the following types of loads under empty conditions: o Permanent Loads: Dead load of earth cover. o Transient Loads: Highway live loads. Transient loads will be considered acting simultaneously with permanent loads. r Marston's theory of loads on underground conduits will be used to predict external loads on pipes in trenches. Load calculations will be based on soil data developed by soil consultants. V.C.P. and R.C.P. will be designed as rigid pipe. W 4. Manholes and Appurtenances Manholes will be spaced as follows: ..' Pipe Diameter Maximum Manhole Spacing < 66" 600 feet > 69" 1,200 feet In addition, manholes will be placed at the following locations: o Change in invert slope. w o Change in alignment. o At the beginning and end of horizontal curves. Pressure manhole covers will be specified where cover over the pipe is less than two feet. C. FORCE MAIN 1. Sizing The Main Street Pump Station is designed with two banks of five pumps each for a total of ten pumps. Each bank �+ has its own wet well and discharge header. The two headers are joined by a valved crossover line, which allows either bank of pumps to pump through the outlet of either discharge header pipe. This maximizes flexibility at the pump station. r II-4 e+' A double-barrel force main is proposed to maintain this maximum flexibility. A double-barrel force main allows use of one barrel only in the early years to keep the velocity as high as possible. The second barrel would be available as a backup in the event of a problem with the first barrel. Two barrels of equal sizes are proposed so that capacity is not sacrificed in the later years when one is out of service. One of the equal sized barrels will provide capacity for a significant portion of each day when design flows are reached. As a result, maximum reliability is maintained for the overall conveyance system. r* Two elements were considered in selecting the force main size; an economic analysis considering construction costs plus energy costs over the service life of the facility and an operational analysis. a. Economic Analysis w The analysis compares the present worth of construction costs plus energy costs over the service .. life of the force main. The optimum pipe size is the one for which present worth costs is a minimum. The calculations for the present worth of energy costs uses a discount rate of 9 percent and a differential r+ rate of inflation relative to the general economy of 2 percent. Inflation of the general economy is not reflected in an economic analysis of this nature. The analysis used a double-barrel force main of equal sizes. The present worth costs are tabulated in Table 2 below. TABLE 2 w FORCE MAIN PRESENT WORTH COSTS Present Worth Costs ($1,000,000) N Diameter inches Pipeline Construction Energy Total 30 2.88 1.85 4.73 r 36 3.34 1.18 4.52 42 3.72 .95 4.67 48 4.19 .86 5.05 54 4.65 .82 5.47 Figure 1 is a plot of the total present worth of costs versus force main diameter of each barrel. The pipe diameters shown are the progressive size increments available for ductile-iron pipe (D.I.P.) . s II-5 �a r 7 J r rn 6 0 U 2 r 0 3 r z w Ul w g a J O . : � . . . . . . . r 4 12 18 24 30 36 42 48 54 60 FORCE MAIN DIAMETER-EACH BARREL ( INCHES) / � COUNTY SANITK"OIDIGTRICT! NO. OJA14 OF ORANGE COUNTY �a IX_ SEWAGE CONVEYANCE FACILITIES L�i�CarjrJOl�dirfor►. FORCE MAIN SIZE-ECONOMIC ANALYSIS LFIG. I r While the cost for the 36-inch-diameter double-barrel .. pipe size is slightly less than the 30-inch or 42-inch diameters, a clear determination is not evident from the economic analysis. b. Operational Considerations Of prime importance in the operation of the force .� main barrels is the flow velocity profile that will result over the life of the facility. Ideally a velocity of between 2.0 and 2.5 feet per second (fps) r at daily peak flow during the initial years is desirable with the maximum velocity at ultimate peak flow limited to approximately 6 fps. The minimum velocity is important to maintain in order to keep �+ solids from settling out in the force main and creating a potential blockage. The maximum velocity is limited in order to minimize the possibility of r, erosion of the pipe material due to suspended solids and grit within the sewage. In addition, a high velocity necessitates a greater hydraulic head and, therefore, a greater energy requirement, a factor .� which is reflected in the above economic analysis. It should be noted that surge pressures resulting from such occurrences as power loss are usually less at lower velocities. These ideal velocity conditions, however, are not attainable for this facility due to the large s projected annual flow variation and the low initial flows. Table 3 lists the velocity in the force main for varying flow and pipe barrel sizes. s II-6 r TABLE 3 FLOW VELOCITIES IN FORCE MAIN velocity in fpa Total Flow Force Main Barrel Diameter Mgd cfs 36" 42" 48" r INITIAL SUMMER (1) average 5.9 9.1 1.3 0.9 0.7 peak 9.1 14.1 2.0 1.5 1.1 r INITIAL WINTER (1) average 19.4 30.0 4.2 3.1 2.4 peak 27.2 42.1 5.9 4.4 3.4 .r ULTIMATE SUMMER (2) average 41.9 64.9 4.6 3.6 2.6 peak 55.2 85.5 6.0 4.4 3.4 ULTIMATE WINTER (2) average 60.4 93.5 6.6 4.9 3.7 peak 77.3 119.6 8.5 6.2 4.7 ,r --------------------- (1) Total flow in one barrel. ^" (2) Total flow divided eq ually between both barrels. Considering results of the economic analysis weighed d against the operational characteristics, the 42-inch- diameter force main barrel size appears to be the best. Both barrels being of equal size are most compatible with the Main Street Pump Station, which is designed for two banks of equally sized pumps, each discharging independently to its force main barrel. This interchangeability allows maximum system flexibility. 2. Pipe Material The 42-inch-diameter pipe barrels will be operating at a maximum internal pressure of approximately 25 pounds per square inch (psi) . Ductile-iron pipe (D.I.P. ) is proposed for the force main. Of the pipe materials able to withstand the internal pressure requirements for this pipeline, D.I.P. is available with a lining to resist internal corrosion and is the most economical in this size range. It has a successful history within the District's systems. It is recommended that the interior be lined with a fusion-bonded polyethylene lining to provide increased resistance to internal corrosion. w II-7 w1 r D. SIPHON DESIGN The profile of the gravity interceptor, which is controlled by the hydraulic grade line (HGL) at the treatment plant headworks, will require two siphons, one beneath the Santa Ana River and one beneath the Greenville-Banning flood control channel. The siphon beneath the Santa Ana River is necessitated by the proposed improvements of the U.S. Army Corps of Engineers, which calls for lowering and widening of the channel-s invert. Current planning calls for lowering the invert s approximately 7 feet and constructing a wider rectangular channel section along this area. The proposed river improvements will also interfere in profile with the existing ,r District No. 6 Air Base Trunk No. 2, which crosses the existing Santa Ana River channel with approximately 3 feet of cover. To provide for this eventuality, flow from the existing Air Base Trunk No. 2 will be intercepted upstream and combined with this project for a single siphon crossing of the river channel. This will provide the additional advantage of increasing the early year flow in the siphon and improving its operation. The Air Base Trunk No. 2 will, therefore, not require relocation in the future when the channel improvements are constructed. ^" The following criteria will be used in the design of the siphons: e. 1. Number and Size of Barrels The District's established maintenance program includes frequent cleaning of all trunk sewer siphons, normally at approximately three-month intervals. Experience in the Districts has shown that siphons with a single barrel operating continuously throughout the day coupled with the above cleaning frequency provide the best operational characteristics. Intermittent use of a barrel results in odors and deposits of grease and solids that lead to blockages. Consequently, the siphons will be designed ^' for a barrel sized to produce as great a velocity in the early years as possible without excessive head loss at ultimate peak flow. Preliminary hydraulic analysis indicated that a 66-inch siphon barrel will keep the head loss within the range necessary to allow the upstream profile to meet the hydraulic commitments of the trunk sewer system. The diurnal flow through the siphon will vary throughout the year as the demand of the IRWD's water reclamation ,r program fluctuates. During the summer months when demand for reclaimed water is high, flow diverted by IRWD to the District's system will decrease with a corresponding reduction in flow through the siphons. The opposite will w II-S 1 L be the case during winter months when the reclamation �.. demand is low. The 66-inch barrel would operate over the range of flow in the manner shown in Table 4 . TABLE 4 r FLAW VELOCITY IN 66-INCH SIPHON BARREL r Flow Velocity (mgd) (fps) INITIAL - Summer Average Flow 19.7 1.3 Peak Flow 27.6 1.8 INITIAL - Winter Average Flow 33.2 2.2 Peak Flow 44.6 2.9 ULTIMATE - Summer Average Flow 63.8 4.2 Peak Flow 81.2 5.3 ULTIMATE - Winter Average Flow 82.2 5.3 r Peak Flow 102.6 6.7 r 2. Depth Below the Channel Bed The siphon barrels will be placed at a level beneath the channel bed that will not subject the pipe to exposure ee from future foreseeable erosion of the streambed and is compatible with the future channel improvements. The barrel will be encased in reinforced concrete and a large size rock riprap apron placed on the downstream side of the encasement for further protection against damage from streambed scour and erosion. 3. Access Structures An inlet and an outlet structure will be located in an area accessible by trucks for maintenance and diversion " operations. The structures will be lined with PVC liner plate to protect against internal corrosion. The upward slope of the downstream leg of the siphon profile into .. the outlet structure will be limited to 15 percent to enable moving solids upward during cleaning by the balling method. 4. Air Vent An air vent will be provided between the inlet and outlet structures to allow the offensive atmosphere of the sewer system, which travels with the sewage flow, to continue across the siphon rather than escape to the atmosphere .w through the manhole covers on the upstream structure. II-9 .r r r Two types of air vents or "jumpers" were considered: (1) an aboveground pipe suspended above the hydraulic grade line (HGL) of the sewer, and (2) a belowground pipe that runs parallel to the siphon. Figure 2 illustrates the alternative concepts at the Santa Ana River Siphon. r In the case of the Santa Ana River Siphon, the aboveground air jumper requires a costly pipe bridge to support the suspended pipe. This structure will require modifications to accommodate future widening of the Santa Ana River. One positive aspect of this alternative is that it requires no energy to maintain air movement. The cost of the pipe bridge in comparison to that of the underground alternative is significantly greater. However, at the Greenville-Banning Channel Siphon, an air ,y jumper above the HGL is not feasible due to the ground surface elevation and the surrounding surface improvements. r The underground air jumper consists of a sloping pipe ending at a pump well structure that will collect condensate and water that may enter the vent pipe. The water can then be removed periodically using a sump pump. Continuous positive air flow is maintained using a fan located in the outlet structure. The fan will be an item requiring maintenance and replacement from time to time. In reviewing this concept with the District staff, it was felt that, since a ventilation system will be installed at the new headworks expansion, just downstream of the Santa Ana River Siphon, enough pressure differential may be created across the Santa Ana River Siphon by installing a fan in the air jumper at only the Greenville-Banning Channel Siphon. r Construction of the underground air jumper can be performed at the same time as the siphon construction. The V.C.P. material proposed is less expensive than the pipe material that would be required for the aboveground alternative and is most resistant to corrosion from the sewer atmosphere. The belowground alternative is, therefore, recommended. r r r1 II-10 r PIPE BRIDGE ABOVE GROUND ALTERNATIVE SS' AIR JUMPER FAN 84' GRAVITY SEWER 78' PIPE \ - SANTA ANA 1 RIVER w/Y SS' VCP PIPE / PUMP WELL SIPHON BELOW GROUND ALTERNATIVE SANTA ANA RIVER SIPHON PROFILE N.T.S. COUNTY SANITATION DISTRICTS NO.E.7&1/ OF ORANGE COUNTY =1 Kw llll�ff X4 SEWAGE CONVEYANCE R\CLfTES m7n• I AR MWER CONCEPTS M 2 SECTION III ROUTE ANALYSIS A. ROUTE ALTERNATIVES The purpose of this trunk sewer is to convey flows from the ,y Main Street Pump Station through the City of Costa Mesa and into the CSDOC's Reclamation Plant No. 1. Several alternatives have been identified and analyzed, including the possibility of paralleling the San Diego Freeway through various existing easements. This alignment, however, is not feasible due to numerous tunnelings required under freeway ramps and overcrossings which make the cost of this route ,r excessive in comparison to other alternatives. The feasible alternatives are described below and shown on Figure 3 at the back of this report. The alternative routes have two intermediate common points--the intersection of Gisler Avenue and Washington Avenue and the intersection of Baker Street and College Avenue. The route analysis is, therefore, divided into the three reaches defined by these common points. 1. Main Street Pump Station to Baker Street and College Avenue r ALTERNATIVE "A" This route commences at the Main Street Pump Station and proceeds in a southwest direction parallel to the northwest property line of the John Wayne Airport through the airport parking lot. It continues in a southwest direction as it tunnels under the San Diego Freeway. It then proceeds west into the Airport Loop Drive cul-de-sac and continues southwest in Airport Loop Drive and southwest in Airway Avenue until it reaches Baker Street East, west in Baker Street East to College Avenue. This alternative is composed of three pipe types and sizes. From the Main Street Pump Station to the intersection of Baker Street and the Santa Ana-Delhi Channel, it is comprised of approximately 10,080 linear feet (L.F. ) of double-barreled 42-inch force main sewer. From the Santa Ana-Delhi Channel to the intersection of Baker and Fairview it is comprised of approximately 6,720 L.F. of 78-inch gravity trunk sewer. From the intersection of Baker and Fairview to the intersection of Baker and College it is comprised of approximately 2,700 L.F. of 84-inch gravity trunk sewer. Baker Street is a major east-west arterial street and carries a relatively high volume of traffic particularly during rush hours. The portion between Bristol Street and Harbor Boulevard appears to be the most heavily III-1 r r traveled. Development along this section of Baker Street is comprised of primarily community commercial types with the residential areas facing interior tracts away from Baker Street. This route passes a parochial school and church east of Mendoza Drive. Although the route also passes a church just west of Fairview Road, this church has access off Loren Lane. r ALTERNATIVE "B" Alternative "B" is identical to Alternative "A" up to the intersection of Air Loop Avenue and Paularino Avenue At this point the alignment changes direction and proceeds northwest in Paularino to Bear Street, and southwest in Bear approximately 750 L.F. It then extends in a northwest direction tunneling under the southbound offramp of the Corona del Mar Freeway for approximately 200 L.F. to the Helena Place cul-de-sac. Following Helena to Helen Place and north in Helena Place to .+ Paularino Avenue, it continues west in Paularino crossing Fairview Road in a west direction the the Donreal Place cul-de-sac. It turns west in Donreal to Loren Lane, and southwest in Loren to Baker Street continuing west in r Baker until it reaches College Street, the common point with the other alternates. This alternative is composed of three pipe types and sizes. From the Main Street Pump Station to the intersection of Paularino and the Santa Ana-Delhi Channel, it is comprised of approximately 9,720 L.F. of double-barreled 42-inch force main sewer. From the intersection of Paularino and the Santa Ana-Delhi Channel to the intersection of Paularino and Fairview it is comprised of approximately 7,350 L.F. of 78-inch gravity trunk sewer. From the intersection of Paularino and Fairview to the intersection of Baker and College it is comprised of approximately 3,300 L.F. of 84-inch trunk sewer. The Paularino Avenue route passes through a predominantly residential area. It passes one elementary school at Coolidge Avenue and a church at Loren Lane and Baker r Street. West of Bear Street, it is a relatively narrow street (one lane in each direction without a striped median) with residences fronting the street. East on Bear Street a striped median has been added. ALTERNATIVE "C" r Alternative "C" is identical to Alternatives "A" and "B" up to the intersection of Air Loop Avenue and Paularino Avenue. At this point the alignment changes direction and proceeds northwest in Paularino to Bear Street, southwest in Bear to the intersection of Bear and Baker Street. From this point on, the alignment is identical to Alternative "A" up to the intersection of Baker and III-2 r d College Avenue. This alternative is composed of three r pipe types and sizes. From the Main Street Pump Station to the intersection of Paularino and the Santa Ana-Delhi Channel, it is comprised of approximately 8,720 L.F. of double-barreled 42-inch force main sewer. From the " intersection of Paularino and to the intersection of Baker and Fairview, the pipe is comprised of approximately 7,260 L.F. of 78-inch gravity trunk sewer. r From the intersection of Baker and Fairview to the intersection of Baker and College, the pipe is comprised of approximately 2,700 L.F. of gravity trunk sewer. 2. Baker Street and College Avenue to Gisler Avenue and Washington Avenue r ALTERNATIVE "D" This route commences at the intersection of Baker Street and College Street, then proceeds north in College, until it reaches Gisler Avenue, west in Gisler to the intersection of Gisler Avenue and Washington Avenue. This alignment is comprised of approximately 7,800 L.F. ,. of 84-inch gravity trunk sewer. There are several storm drain facilities crossing the alignment in the vicinity of Harbor Boulevard; these will require the addition of two short siphons in the profile. r ALTERNATIVE "E" The commencement point of this route is identical to that of Alternative "D" and will proceed west in Baker until it reaches Deodar Avenue, continuing north in Deodar Avenue, Nutmeg Place, Mace Avenue, Caraway Drive, and r Cinnamon Avenue to Gisler Avenue, where it travels west in Gisler to Washington Avenue. This alignment is comprised of approximately 11,550 L.F. of 84-inch gravity .,, trunk sewer. It parallels a 60-inch storm drain between Baker Street and Gisler Avenue and crosses the District's 30-inch trunk sewer just south of Gisler Avenue. ALTERNATIVE "F" Again from the same commencement point as Alternative "D" r, and Alternative "E," this alignment proceeds on a west direction in Baker Avenue, to Labrador Avenue, continuing northwest in Labrador to Gibraltar Avenue. From this point, it continues north in Gibraltar to Gisler Avenue, " and west in Gisler to the intersection of Gisler Avenue and Washington Avenue. This alignment is comprised of approximately 7,920 L.F. of 84-inch gravity trunk sewer. r III-3 r r 3. Gisler Avenue and Washington Avenue to Reclamation Plant No. 1 ALTERNATIVE "G" r This route commences at the intersection of Gisler Avenue and Washington Avenue, then proceeds west in Gisler - approximately 800 feet where the street profile drops significantly. The interceptor would then deflect southerly into the Mesa Verde Country Club golf course, where some regrading adjacent to the north side of one fairway would be required to provide cover over the pipe. A 600-foot siphon beneath the Greenville-Banning Channel from an inlet structure located in the golf course property to the west side of the channel is required. ,r The alignment then parallels the Greenville-Banning Channel in an easement from a parcel of private property between the channel right-of-way and Southern California Edison (SCE) right-of-way to the point where the Santa Ana River syphon begins. ALTERNATIVE "H" r The commencement point of this alternative is identical to that of Alternative "G" but will proceed in a northbound direction in Washington Avenue to the intersection of Illinois Street and Washington Avenue, in Illinois until it reaches the intersection of Indiana Avenue and Illinois Street and in Indiana until it reaches the T-intersection at Iowa Street. At this point, the trunk sewer will siphon underneath an existing residence and the Greenville-Banning Channel in one siphon. From this point, it will proceed in a northwest direction to the point where the Santa Ana River Siphon begins. This alignment is comprised of approximately 2,450 L.F. of 84-inch gravity trunk sewer. It also parallels and crosses existing utilities along the length of the route. ALTERNATIVE "J" r Again the commencement point of the alternative is identical to that of Alternative "G" and proceeds north in Washington Avenue until it reaches the T-intersection of California Street From this point, it proceeds in California until it reaches the end of Nevada Avenue, where it continues through a community park and along SCE's right-of-way to the Santa Ana River Siphon. This alignment is comprised of approximately 3 ,950 L.F. of 84-inch gravity trunk sewer. .r III-4 4. Fairview Relief Interceptor - Fairview Road from Wilson Street to Baker Street This route commences at the intersection of Wilson Street and Fairview Road and continues in the east side of Fairview Road until it reaches the Paularino Channel. Approximately 100 feet north of the channel the alignment traverses across Fairview Road to the west side to Baker r Street and connects to the 84-inch Gisler-Baker Trunk Sewer. Because of the location of service commitments which include relieving the existing trunk sewers at three locations, the route of the proposed trunk sewer is limited to the east side of Fairview Road. After intercepting the three existing sewers, the alignment will cross Fairview from east to west to join the 84-inch trunk sewer at Baker Street. r B. COST COMPARISON r The estimated construction costs of the alternative routes for the respective reaches are summarized in Table 5 for comparison. The costs include only those items which differ between alternates. They do not include common items, such as manholes, structures, and appurtenances. Section VII presents a detailed construction cost estimate of facilities following the selected route. r r r r III-5 r r r TABLE 5 r CONSTRUCTION COST COMPARISON OF ALTERNATIVE ROUTES r' Alternate Length (L.F. ) Estimated Construction Cost 1. Pump Station to Baker Street/College Avenue A 19,500 $ 9,300,000 B 20,250 10,200,000 C 19,700 9,400,000 r 2. Baker Street/College Avenue to Gisler Ave/Washington Ave D 7,800 $E 8, 160 q,700,000 F 7,920 4,600,000 r 3. Gisler Avenue/Washington Avenue to Santa Ana River r G 3,600 $ 2,200,000 R 2,460 2,100,000 (1) J 3,600 2,400, 000 to (1) Includes purchase of existing property on Iowa Street at 150 percent of estimated current price plus tunneling beneath the existing house. The potential recovery of some portion of this cost by resale of the property is not included. r C. ANALYSIS AND SELECTION Analysis of the alternative routes considered construction feasibility, community impact, economics, existing utilities, and future trunk sewer maintenance operations. Table 6 at the end of this section summarizes the advantages and +' disadvantages specific to each alternative. 1. Main Street Pump Station to Baker Street and r College Avenue Of the three alternatives "A, " "B," and "C" in this reach, Alternative "A" was selected for recommendation r for the following reasons: a. Baker Street includes two lanes in each direction r, plus a median, while Paularino Avenue between Bear Street and Bristol Street has only one lane in each direction plus a median, and west of Bear Street it has no median. Even though a higher volume of r III-6 .r r traffic is encountered on Baker Street than on Paularino Avenue, additional width of Baker Street will allow the pipeline construction to occur only on the north half (westbound) of the road, leaving the south half available for traffic. Temporary lane configurations could be designed to minimize traffic delays. For instance, during construction hours, one lane could be open in the west direction and two .. lanes available for eastbound traffic. After construction hours, a second lane on the north side of the street could be returned for westbound traffic. The narrower Paularino Avenue does not have sufficient room to allow this traffic control method and it would probably require closing Paularino Avenue to through traffic west of Bristol Street for safety in view of the construction area required to install an 84-inch pipeline. b. The impacts that would be experienced by the overall community would be greater from construction along Paularino Avenue than along Baker Street. Development along Paularino Avenue between Bear ., Street and Fairview Road is strictly residential with many properties fronting on Paularino Avenue. In addition, the Paularino Elementary school is located on Paularino Avenue at Coolidge Ave. East of Bear Street the residential development surrounding Paularino Avenue faces the interior tracts rather than directly on the street. Although a parochial .. school is located on Baker Street at Mendoza Drive, it has its primary access from Mendoza Drive. Along Baker Street the residential development faces away from the street and in fact between Babb Street and Fairview Road a block wall on the north side of the street will help to serve as a buffer between the .. adjacent properties and the construction activities. Access to residences north of Baker Street can be gained using the local north-south streets to r Paularino Avenue. The narrow width of Paularino Avenue west of Bristol Street and the larger 72-inch pipe would necessitate closing the street to vehicular traffic in phases. This would result in access delays for residents of the surrounding area. Also, inconveniences may be experienced from noise and dust during the actual construction. Along . Baker Street, these types of impacts will be significantly less. The commercial development on Paularino Avenue is centered primarily around Bristol Street and access could easily be gained from Bristol Street. Along r Baker Street the commercial establishments are III-7 r located for the most part on the south side of the street. By maintaining the vehicular traffic on the south side during construction, access will easily be maintained to the adjacent business during construction. Residential condominium projects on the north side of Baker Street between Babb Street and Bristol Street will have continuous access during construction. r It should be noted that continuous unobstructed ingress and egress must be maintained to the fire station on Baker Street at the Corona del Mar Freeway at all times during construction. c. Alternative "A" is shorter in length by 750 L.F. than Alternative "B" and by 200 L.F. than Alternative "C," which translates into a lower overall construction cost. Alternative "B" would also require approximately 200 L.F. of tunnel under the Corona del Mar Freeway offramp near Bear Street, which adds to the construction cost differential. Using the summary in Table 2, the construction cost ,., of Alternative "A" is estimated to be $920,000 less than Alternative "B" and $140,000 less than Alternative "C." d. Utility involvement is essentially the same for the three alternatives. Existing water and sewer mains and a recently installed storm drain on the south .. side of Baker Street require locating the pipeline on the north side of the street. This is also the preferred location with regard to traffic control as previously pointed out. Along Paularino Avenue east of Bristol Street, there are no major utilities, although the local distribution utilities will force the pipeline alignment to the center of the street. r e. From a maintenance standpoint, Alternative "A" or "C" would facilitate cleaning operations of the trunk sewer by virtue of its straighter alignment in the vicinity of Bear Street. The wider Baker Street would allow easier access to manholes for cleaning vehicles without excessive traffic impact. r 2. Baker Street and College Avenue to Gisler Avenue and Washington Avenue Alternatives Routes "D, " "E, " and "F" were analyzed in this reach. Taking into consideration construction feasibility, community impact, economics, existing utilities and future maintenance operation, the recommended alternative for this reach is Alternative "F. " r III-8 r L r A profile for Alternative "D" cannot be developed to maintain gravity flow from the hydraulic control elevation at Reclamation Plant No. 1. The existing surface profile along College Avenue as it approaches Gisler Avenue and along Gisler Avenue itself across Harbor Boulevard is below that necessary to maintain a minimum amount of cover over a gravity sewer profile. As a result, Alternative "D" was eliminated as a choice for r the trunk sewer alignment. Alternatives "E" and "F" continue westerly on Baker Street, crossing Harbor Boulevard. It should be noted that an improvement project on Harbor Boulevard which cannot be delayed is scheduled for this year and will preclude construction along this portion of Harbor Boulevard. Alternative "E" follows a circuitous route along narrow streets between Baker Street and Gisler Avenue. The properties bordering are both commercial and residential. This route follows storm drain for most of the way. Construction of the 84-inch interceptor will be difficult ,r along this route because of (1) the many turns to be negotiated, (2) the necessity to relocate at least the local sewers to make room for the large pipeline, and (3) the necessity to construct a junction/diversion structure where it crosses the existing 30-inch Air Base Trunk No. 2. These streets would require closing to vehicular traffic, which would result in significant inconveniences to the adjacent commercial and residential properties. Alternative "F" continues on Baker Street and follows a more direct route along Labrador Drive and Gibraltar Avenue to Gisler Avenue. It does travel through a strictly residential area of single family houses. The r, primary impact would be inconveniences to the residences fronting on Labrador Drive and Gibraltar Avenue. These would stem from potential delays in vehicular access to their driveways and from the noise and dust generated from the construction activities. Measures to minimize these impacts will be discussed later in this report. It is felt, however, that with mitigating measures to minimize the construction related inconveniences to the residences along Labrador Drive and Gibraltar Avenue, Alternative "F" is least impacting to the overall community. Significant utility relocations are not required for Alternative -IF.'- Alternative "F" is approximately 240 feet shorter than Alternative "E" and, in terms of construction cost, is $150,000 less. r III-9 r r 3. Gisler Avenue and Washington Avenue to r Reclamation Plant No. 1 The profiles of all three alternatives, "G, " "H," and "I," require a siphon beneath the Greenville-Banning Channel. The siphon of Alternative "H" continues beneath an existing house with the upstream end terminating at a depth of only 2 feet below the street surface. This �. shallow upstream depth, however, does not allow sufficient room for the water surface to rise in the manhole during the cleaning operation. The profile of Alternative "H," therefore, is not operationally '+ feasible. Alternative "J" is more costly than Alternative "G" by $200,000 because of the more circuitous route for this large pipe and the necessity to construct junction structures with the two existing District trunk sewers to resolve profile conflicts. In addition, Alternative "J" 'r would present significantly greater impacts to the surrounding community, since it travels through the center of a heavily residential area. r Alternative "G" would present some inconvenience to the Mesa Verde Country Club golf course during construction along one fairway and during the regrading and landscaping construction. However, the use of this fairway should not be interrupted. Construction along the remainder of Alternative "G" should not impact the other community elements significantly. The portion paralleling the Greenville-Banning Channel on the west side is outside the proposed improvements of either the Santa Ana River or Greenville-Banning Channel as shown on the Corps of Engineers' current preliminary plans received in April 1987 and titled "Santa Ana River, California, Phase II General Design Memorandum," Sheets 34 and 44. Consequently, Alternative "G" is recommended. 4. Fairview Road from Wilson Street to Baker Street AI The alignment for this route is best situated in the outermost travel lane on the east or northbound side of Fairview Road. This location for the trunk sewer is dictated by the District's existing trunk sewer which must be relieved at three locations and other utilities on the west or southbound side which includes a storm drain ranging from 30 inches to 60 inches. Also, various existing 8-inch water and sewerlines provide enough longitudinal conflict to force the proposed trunk sewer to the eastside of Fairview Road. By occupying the outermost travel lane, it provides a space and allows a construction zone which minimizes the traffic inconveniences. Because of the wide street configuration III-10 r which includes one bike lane, three travel lanes and a r median, the construction zone will allow one lane open for through traffic during construction hours and two through lanes after construction hours. Thus, the inconvenience to the motoring public will be held to a r minimum. Review of the alignment of the existing Air Base Trunk r No. 2 between Arlington Avenue and Adams Avenue notes the existing trunk is beneath a building of the Costa Mesa High School. It is, therefore, not feasible to follow the easement of this existing trunk sewer. r r r r 1Y 1 r r III-11 r TABLE 6 COUNTY SANITATION DISTRICTS NOS. 6, 7, AND 14 SEWAGE CONVEYANCE FACILITIES ti SUMMARY OF ADVANTAGES/DISADVANTAGES FOR ALTERNATIVE ROUTES ,r ALTERNATIVE SPECIFIC ADVANTAGES SPECIFIC DISADVANTAGES Main Street Pump Station to Baker Street and College Avenue 'A" 1. Minimum inconvenience 1. Heavier arterial to surrounding resi- traffic dential areas. r 2. Shorter by 700 L.F. 3. Lowest construction r cost by $140,000. "B" 1. Less through 1. Longer route than traffic. Alt. "A" by 750 L.F. 2. Requires closure to through vehicular traffic due to narrower streets. 3. Inconvenience to sur- rounding residential areas with many fronting directly on the street. 4. Higher const. cost .. than Alt. "A" by $920,000. 5. Passes one elemen- tary school. 6. Approximately 200 r L.F. of tunneling beneath freeway offramp. m' "C" Since this alternative is a combination of Alt. "A" and Alt. "B" the advantages and disadvantages are similar in description with the exception that Alt. "C" is longer than Alt. 'A" by 200 L.F. and the inconvenience surrounding residential area is less than for Alt. "B. " r III-12 �i TABLE 6 (Continued) COUNTY SANITATION DISTRICTS NOS. 6, 7, AND 14 SEWAGE CONVEYANCE FACILITIES d SUMMARY OF ADVANTAGES/DISADVANTAGES FOR ALTERNATIVE ROUTES ALTERNATIVE SPECIFIC ADVANTAGES SPECIFIC DISADVANTAGES Baker Street and College Avenue to Gisler Avenue and Washington Avenue "D" -- 1. Gravity sewer not feasible due to sur- face profile. M� "E" 1. Minimum inconvenience 1. Inconvenience to com- to through arterial mercial and residen- vehicular traffic. tial areas due to circuitous alignment. 2. Inconvenience re- quires closure to through vehicular '^ traffic due to nar- rower streets. r 3. Longer route than Alt. "F" by 200 L.F. 4. Higher const. cost than Alt. "F" by $140,000. 1. Shorter route than 1. Inconvenience to resi- Alt. "E" by 200 L.F. dences on Labrador Avenue and Gibraltar Avenue which front on the street. 2. Lower construction 2. Inconvenience re- costs than Alt. "E" quires closure to by $140,000. through vehicular traffic due to nar- rower streets. 3. Minimum inconvenience to through arterial vehicular traffic. r III-13 r r TABLE 6 (Continued) r COUNTY SANITATION DISTRICTS NOS. 6, 7, AND 14 SEWAGE CONVEYANCE FACILITIES o SUMMARY OF ADVANTAGES/DISADVANTAGES FOR ALTERNATIVE ROUTES ALTERNATIVE SPECIFIC ADVANTAGES SPECIFIC DISADVANTAGES "G" 1. Minimum inconvenience 1. Longer siphon under to through vehicular Greenville-Banning r traffic. Channel. 2. Golf course route out 2. Easement required. of right-of-way. 3. Lower construction 3. Additional landscape cost than Alt. "J" by cost. $200,000. 4. Inconvenience to golf course. "H" 1. Shorter route than 1. Surface cover shallow Alt's. "G" and "J. " at upstream siphon structure resulting in operationally non- feasible profile. r 2. Inconvenience to resi- dential area due to circuitous route. 3. Inconvenience requires closure to through vehicular traffic due to narrow streets. 4. Siphon under house re- quired plus easement. r 1. Shortest siphon. 1. Inconvenience to resi- dential area due to r circuitous route. 2. Inconvenience requires closure to through r vehicular traffic due to narrow streets. r 3. Higher construction cost than Alt. "G" by $200,000. III-14 _ SECTION IV ALIGNMENT AND PROFILE ALONG RECOMMENDED ROUTE A. ALIGNMENT Utility information and improvement plans have been gathered along the route of the sewage conveyance facilities and a preliminary alignment has been selected within the streets. Figure 4, Sheets 1 through 8 in the pocket at the back of this report, presents a preliminary plan and profile for the entire force main and gravity interceptor system. Existing major utilities which serve to control the location of the pipelines within the street are plotted in both the plan and profile views. A The proposed pipeline alignments have been selected to minimize conflicts or involvement with existing utilities while allowing vehicular traffic to continue past the construction zone with as little delay as possible. The objective is to allow a contractor to develop an efficient train of pipeline construction activities while minimizing „r the impacts to the overall community. Along Baker Street from approximately College Avenue easterly, an alignment was selected on the north side of the 's street for several reasons. The major longitudinal trunk utilities are on the south side along this portion of Baker Street--a 30-inch to 60-inch storm drain, a 16-inch waterline ,., and 8-inch local sewer mains. The north side on the other hand is relatively unencumbered with utilities. The District's 18-inch Air Base Trunk No. 1 may be intercepted at Mendoza Drive, allowing the new trunk to occupy its location. The remaining reaches of the Air Base Trunk No. 2 can then be abandoned downstream. Locating the sewers on the north side will allow room on the south past the construction zone for two eastbound lanes at all times and one westbound during working hours with a second westbound lane added at all other times. Subsection VI, D, of this report further describes the traffic control and phasing plan concept. a West of Harbor Boulevard, an existing 54-inch storm drain, 12-inch water main and 8-inch local sewer forces the alignment to the center of the street. No major utility relocations are foreseen at this time. There may be a few distribution size utility relocations required. IV-1 .d B. PROFILE 1. Gravity Interceptors The following points serve to control the profile of the 'd gravity trunk sewers: o The HGL elevation at the Reclamation Plant No. 1 headworks established by the design of Contract No. P1-20. The point of interface between Contract No. P1-20 and the Baker-Gisler Interceptor is the siphon outlet structure across the Santa Ana River. '^ Following are the controlling data set by the headworks design: Invert Elevations of 78-Inch Outlet = 15.45 Water Surface Elevation at Peak Day Flow of 100 cfs = 19. 04 ed o Interception of the District's Air Base Trunk No. 2 in Fairview Avenue at the Paularino Flood Control Channel. Under Contract No. 6-11, a 21-inch VCP was constructed along the Paularino Flood Control Channel sloping to the west from the existing Air Base Trunk No. 2 to Fairview Road. This dry sewer will be intercepted and manhole modification work done on the east end to activate this line and allow abandonment of the Air Base Trunk No. 2 between the ® Paularino Channel and Baker Street. o The hydraulic commitment to relieve the District's existing Fairview Road Trunk Sewer between Baker �! Street and Wilson Avenue. The depth and profile of the existing Fairview Road Trunk Sewer controls the slope of the Fairview Relief Interceptor. A 27-inch pipe size is required for conformance with the criteria of Section II-B. This results in sufficient excess capacity between Fair Drive and the Paularino Channel to allow abandonment of the •" Air Base Trunk No. 2 south of Salvador Street, which is over 45 years old. Frelimin4 (in pocket at back of report) shows a preliminary profile with pipe sizes and slopes and the major utilities that cross the pipeline route. s 2. Force Main The purpose of the force main is to convey flow from the Main Street Pump Station to the gravity interceptor system serving District No. 6. The westerly most terminus of the force main is, therefore, Fairview Road. This results in a 17,000-foot-long force main. IV-2 r r Review of the gravity system and roadway surface profiles indicated the gravity sewer could be continued easterly, joining the force main at the Santa Ana-Delhi Channel. This would shorten the force main to 9,400 feet in length. - An economic comparison was made of the life cycle costs of these two alternative force main/gravity interceptor r interface locations. The analysis compared the capital (construction) costs plus pumping energy costs over a 50-year service life for the facility. The present worth of these costs in 1987 dollars were compared using a discount rate of 9 percent over the 50-year life for the pumping energy costs. Flow buildup for the determination of energy costs parallels that of the addendum report to the 1982 Consolidated Master Plan of Trunk Sewer Facilities as follows: en Average Flow (mgd) r Tributary Area 1990 2030 Winter Months CSD No. 7 5.5 10.0 IRWD 14.5 45.0 20.5 55.0 w Summer Months CSD No. 7 5.5 10.0 �= IRWD 0.5 25.0 6.0 35.0 The summer months flow reflects the seven-month period when IRWD reclamation demands are greatest and the winter months flow is the remaining five months when reclamation r demand declines. The analysis compares only those elements that differ between alternatives. The appendix includes two tables that itemize on a year-by-year basis the annual pumping energy costs at the Main Street Pump Station. A double. barrel 42-inch force main was used for pumping energy �+ calculations and a 78-inch diameter pipe for the gravity sewer portion. Table 7 summarizes the present worth costs for comparison. r r IV-3 r r TABLE 7 ECONOMIC COMPARISON FORCE MAIN TERMINUS ALTERNATIVES d Present Worth Cost (1987) Force Main Term nus Force Main Terminus Cost Element at Fairview Road at S.A.-Delhi Channel CAPITAL COSTS Force Main $7,395,000 $3,660,000 r Gravity Sewer 0 3,885,000 Subtotal 7,395,000 7,545,000 ANNUAL COSTS Pumping Energy 1, 130,000 1,410, 000 ..i TOTAL $8,525,000 $8,955, 000 w The total present worth costs are slightly more for the shorter force main, although the difference is within the accuracy of this level of estimates. e+ The two alternative force main terminus locations were reviewed for other considerations. In terms of reli- ability, the shorter 9,400-foot-long pressure line would have less exposure to problems than the longer 17,000-foot alternative. In addition, the extension of the gravity system east of Fairview Road allows District No. 6 additional flexibility for future gravity service e� within its service area. As a result, to afford maximum reliability for this backbone conveyance system without sacrificing excessive life cycle costs, the shorter force main terminating in the vicinity of the Santa Ana-Delhi Channel is recommended. w C. COMMUNITY IMPACT Construction of the trunk sewer pipeline in City street right-of-way will necessarily cause some degree of inconvenience to various aspects of the community, i.e. , residents, businesses, industry, schools, churches, and the motoring public. The following identifies those elements of wr the community that may be affected by the construction activities of the proposed trunk sewer. During the final design phase, measures will be developed to mitigate these inconveniences. Possible solutions that will be considered are discussed: IV-4 r 1. Traffic Control The pipeline routing follows two prime arterial streets of the City of Costa Mesa, Baker Street and Fairview Road, which carry vehicular traffic through the e' community. They are crossed by other arterial streets at approximately half-mile to mile intervals. Traffic on the remaining streets is local in nature. A suggested phased construction/traffic control plan will be developed to minimize impact during construction and is conceptually presented in Section VI. The contractor will be responsible for submitting final phased construction/traffic control plans for agency approval. There will be some inconveniences to the motoring public ,e during the construction process; however, these are short lived and minimized by maintaining traffic through the construction zone. We have found in major pipeline construction that stipulating construction zone detouring �+ of traffic from normal patterns in approximate half-mile segments between major cross streets results in an efficient interval for the construction process without ,y creating major delays to the motoring public. Further, by specifying that restoration follow the pipelaying heading closely as it progresses forward, traffic can be returned to normal patterns expeditiously and attendant inconveniences should be minimized. Using this basic approach, a suggested traffic control plan detailing specific requirements will be developed during the final design phase for inclusion into the construction specifications. This plan will be reviewed with the appropriate jurisdictional agencies prior to !' finalizing. The concept which will serve as the basis for the detailed traffic control measures that will be included in the construction contract documents is s, explained further in Section VI of this report. 2. Schools "+ There are seven schools in the proximate area of the proposed trunk sewer: the Mesa Verde, Tewinkle, California, College Park, St. John's Parochial School, Costa Mesa High School, and Orange Coast College. a. The Mesa Verde School at Mesa Verde Drive West and Baker Street near Labrador Avenue has entrances that s border Baker on one side and Mesa Verde Drive West on the other. At the rear of the school, a row of houses border the school's perimeter and shield it from the trunk sewer construction zone. Tewinkle and California Schools at Gisler Avenue and California Street have entrances off of California Street; thus, all three schools will not be directly impacted by s IV-5 r r the construction zone for the proposed trunk sewer. ^, Therefore, inconvenience to the schools is expected to be minimal. Pedestrian traffic along Baker Street, Labrador e' Avenue, Gisler Avenue, and Gibraltar Avenue near the schools will be a major concern, and special care will be provided to defer any danger and to provide w proper safety measures for all children if construction takes place while school is in session. The crosswalk located at the Baker and Labrador intersection will also require special attention, as s it gives access to the children from the south side of Baker Street to the north side. The crosswalk located at Gibraltar Avenue and Gisler Avenue gives access to the children from the west to eastside of Gibraltar and will also require special attention. r b. Costa Mesa High School will front the construction zone. The specifications will stipulate that construction in the vicinity of this school be done r between June 15 and September 1. c. To provide for the safety of school children a+ traveling to and from school, specifications should require that, when school is in session, a guard is placed at all school crossings during normal school r hours while construction is within 500 feet of any school crossing. The final design will investigate the interrelationships of the pipeline location, vehicular traffic, and the school's schedule to er develop specific requirements to mitigate adverse impact to the school as well as the project facilities. ~ d. Orange Coast College, because of its west side location on Fairview, will not be affected directly by the construction zone of the trunk sewer; however, the specifications will stipulate that construction in the vicinity of this school be done between June 15 and September 1. •r 3. Commercial Local businesses, such as shopping centers, retail and .s service businesses, fast food restaurants, medical clinics, and gas stations, are located along the route proposed for the trunk sewer. "Plaza" shopping centers are located at Baker Street and Harbor Boulevard and Baker Street and Fairview Avenue. Each of these plazas has one or more access driveways from the pipeline route; however, major access via one or more driveways is d IV-6 r .d located on the intersecting streets. All of the other ,r businesses (i.e. , gas stations and fast foods) , which total approximately four, are corner establishments with two driveways along the trunk sewer route and two on the r, intersecting street. Approximately three are not corner establishments and will require total access from the trunk sewer route and no driveway of theirs be closed. By requiring that access to at least one of the driveway r entrances from the trunk sewer route to the shopping centers, in addition to all those from the cross streets, be maintained at all times, the inconveniences should be minimal. 4. Industrial Areas w The trunk sewer route in Baker Street east of the Costa Mesa Freeway and in Airway Avenue and Airport Loop Drive travels through industrial areas. By maintaining at least one lane open in each direction on these streets, Baker, Airway, and Airport Loop, access to all traffic, including delivery vehicles, will be provided and thus the inconveniences should be minimal. Since the width of ,., Airway Avenue and Airport Loop Drive cannot accommodate traffic as well as parking and construction, it is proposed that use of the street for parking or stopping be limited during construction. Since the businesses on these streets have off-street parking, this should not create significant hardship. 5. Residential Development Where the trunk sewer travels through residential areas, mostly on Gibraltar Avenue and Labrador Drive and a portion of Baker Street between Labrador Drive and Harbor Boulevard, the majority of the residences front directly on the street. In such cases, maintenance of access will e+ be required at all times. Consideration will be given to restricting work along these two areas to those daytime hours that will minimize disturbances to the residents. On other streets, such as Baker Street and Gisler Avenue, the residences face into the tracts and are sometimes separated from the trunk sewer route by block walls. .. Consequently, these areas should not be affected by the construction. To provide maximum safety for the residents of the surrounding residential developments as well as the general public, the construction specification will provide for the erection of a minimum 7-foot chain link r fence or other means of securement to preclude unauthorized entry to any excavation during all nonworking hours (24-hour basis) including weekends and a holidays. IV-7 r r r 6. Churches R The Districts' standard specifications require the Contractor to maintain maximum access to churches on their sabbath days. R 7. Other Segments R Continuous unobstructed ingress and egress must be maintained to all establishments engaged in work of an emergency nature or directly connected with public safety. The specifications will bring to the + contractor's attention the location of these nearby establishments, such as the fire station at Baker Street and Jeffrey Drive, with regard to this requirement. R D. SANTA ANA RIVER CROSSING + The headworks expansion design of the CSDOC's Reclamation Plant No. 1 has established the HGL elevation. This elevation will necessitate a siphon at the Santa Ana River in r order to cross under the existing channel invert elevation. The siphon will also need to accommodate the Santa Ana River improvement project of the Corps of Engineers, whose preliminary plans show a realignment of the river, along with �+ a lower elevation for the river's invert, and a 246-foot-wide by 21-foot-deep rectangular channel. The existing 39-inch Air Base Trunk No. 2 Sewer crosses + beneath the Santa Ana River with approximately 4 feet of cover at the midpoint of the river. The Corps of Engineers Santa Ana River Improvement Project design will require �+ relocation of this trunk sewer in profile to accommodate the drop in invert elevation of the river. since this conflict would necessitate a future siphoning of the existing 39-inch r trunk beneath the Santa Ana River, it is undoubtedly prudent to route the existing 39-inch trunk sewer to the new 84-inch trunk sewer along the east side of the river combining the flows for a single siphon crossing beneath the proposed .. future Santa Ana River. a E. RIGHT-OF-WAY The streets in which the trunk sewer is located are of sufficient width in which to construct the facilities. Permanent and temporary construction easement will be required at two locations; one in a strip of land between the Santa Ana River, the Greenville-Banning Channel right-of-way, R, and another through the Main Street parking lot of the John Wayne Airport. The easement through the airport parking lot will parallel the northwest property line. Following is a tabulation of dimensions and areas of the proposed easements: s IV-8 r r r Easement Permanent Easement Temporary Easement r Location Length Width Area Width Area SCE Right-of-Way 700' 20' 0.32 so. -- -- East of Santa Ana River 1,400' 20' 0.64 so. 20' 0.64 so. w Mesa Verde Country Club 1,000' 20' 0.46 so. 25' 0.57 ac. Airport Parking r' Lot 500' 20' 0.62 so. 50' 1.55 ac. r r r r r r r r s IV-9 r r r SECTION V r REGULATORY AGENCIES A. GENERAL The regulatory agencies having jurisdiction over various aspects of the project have been contacted as necessary for preliminary coordination. During the final design their requirements will be ascertained for incorporation in the construction specification. The following is a list of the required permits for construction of the sewage conveyance facilities: r Permits Required for Construction of the Sewage Conveyance Facilities Agency Jurisdiction City of Costa Mesa Excavation in public streets ~ Orange County EMA Main Street Crossing (Corps of Engineers) Channel Crossings 1. Airport Storm Channel (F01501) r' 2. Santa Ana-Delhi 3. Greenville-Banning 4. Santa Ana River r Caltrans San Diego Frwy. Crossing Newport Freeway Crossing Corona Del Mar Freeway Crossing Division of Industrial Tunnel Classification Safety r State RWQCB Discharge for Dewatering State Dept. of Fish and Crossing Greenville-Banning Channel, r Game if disturbed ^, B. CITY OF COSTA MESA A construction permit is required for construction of the sewage conveyance facilities within the public right-of-way r of City of Costa Mesa streets. The city's requirements relating to traffic control and pavement replacement will be included in the plans and specifications. r r V-1 r r C. ORANGE COUNTY ENVIRONMENTAL MANAGEMENT AGENCY (ERA) r The Orange County EMA will issue an encroachment permit for construction across several Orange County Flood Control District (OCFCD) channels including Airport storm Channel, Santa Ana-Delhi Channel, Greenville-Banning Channel, and the Santa Ana River. It is anticipated that construction of the trunk sewer beneath the channels can be made by tunneling or „y jacking during the non-storm portion of the year (April 15 to October 15) . This will integrate very well with the proposed time frame of the overall project. The specifications will stipulate this construction within the above dates. r D. CALTRANS r A "Utilities Encroachment Permit" is obtained to construct and maintain facilities across state highway right-of-way. The crossing of the San Diego, Newport, and Corona del Mar Freeways are the only portions affected. Processing is carried out through Caltrans Los Angeles or Orange County offices beginning with submittal of the preliminary plans and an encroachment permit application. Comments from the various divisions of Caltrans will be incorporated into the final plans. It is anticipated an approved traffic control plan can be developed for an open trench installation in r Baker Street beneath the Newport Freeway and Corona Del Mar Freeway. E. DIVISION OF INDUSTRIAL SAFETY (DIS) For all tunneled or jacked casing installations, the r contractor will be required to obtain a permit from DIS to expedite this process, and "underground classification" will be obtained during the final design phase from DIS for each tunnel or jacked casing installation, and included in the specification. r F. REGIONAL WATER QUALITY CONTROL BOARD (RWQCB) The RWQCB requires a permit for the discharge of dewatering effluent from any of the construction activities. CSDOC's blanket permit covering the requirements for such construction activities will be included in the contract specifications. The contractor will be required to comply with the provisions of the permit and furnish the data necessary for the CSDOC to meet the reporting requirements of the permit. r r V-2 r r G. STATE DEPARTMENT OF FISH AND GAME It is anticipated that the Greenville-Banning Channel will be crossed by open trench. An "Agreement for Streambed Alteration" between the District and the State will be r processed, outlining requirements for the construction across the Greenville-Banning Channel. The agreement will be included as a part of the construction specifications. In view of the time frame in which the channels will be constructed, it is felt the requirements should be only the State's standard stipulations. r H. COORDINATION WITH STREET IMPROVEMENTS r Several street improvement projects are proposed by the City of Costa Mesa, and lie within the proposed trunk sewers and force main alignment. The scheduled construction for the street improvements is in the same general time frame as that of the subject sewage conveyance facilities. Schedules for the various city improvement projects are as follows: r Proposed Construction Units Work Period Baker St. - from Airway Avenue to Route 55 Slurry Seal F.Y. 1988-89 r Paularino - from Airway Avenue to Route 55 Slurry Seal F.Y. 1988-89 Baker Street - from Bear Street Bristol Street Rehabilitation F.Y. 1987-88 Baker Street - from Bear Street to Babb Street Rehabilitation F.Y. 1987-88 Fairview Avenue - from Wilson Avenue to Baker r Street Rehabilitation F.Y. 1988-89 Bear Street - from Baker r Street to Route 405 Rehabilitation 1990 Airway Avenue Slurry Seal F.Y. 1988-89 Airport Loop Slurry Seal F.Y. 1988-89 r r V-3 r The construction period for the proposed sewer trunk is tentatively scheduled between July 1988 to December 1989. Since the majority of City projects are also scheduled between this time period, the City might consider the postponement of these projects until the construction of the trunk sewer is completed. In addition to the above, the City has also indicated the following portions of Baker Street are expected to be widened within the next five years: Limits Side of Street r E/o Fairview to Cleveland North E/o Fairview to Milbro South Corona del Mar Freeway to Bristol South .. w/o Bristol North r r V-4 r r SECTION VI r CONSTRUCTION PROCEDURES A. EARTHWORK Excavation for the pipelines will be accomplished by open s, trench except in those specific areas where tunneling or jacking is called out on the plans. The specifications will require that all excavations be performed, protected, and supported as required for safety and in a manner set forth in the operation rules, orders, and regulations prescribed by the CAL/OSHA Construction Safety Orders. For all boring, jacking pits, or open excavations which are 5 feet or deeper, ,r the contractor will be required to obtain a permit from the applicable agency as required by California Labor Code 6424. Also, for all trenches 5 feet or more in depth, the contractor will be required to prepare and submit to the District a detailed plan showing the design of shoring, bracing, and sloping or other provisions to be make for worker protection as required by California Labor Code 6422. The project geotechnical investigation will include soils-related design criteria for use in preparation of and/or reviewing the plan. This will include such information as safe construction slopes, lateral earth pressures for sheeting and shoring design, and the effects of adjacent surcharge loads. Excavation of open trench will be limited to 600 feet or a distance necessary to accommodate pipe installation in a single day. This distance will be collective in length and will include open excavation for pipeline and appurtenances and backfilling which has not been temporarily resurfaced. The contractor will be required to control grading and stockpiling of excavated material in a manner to prevent water from running into excavations. Obstructions of surface drainage will be avoided and means provided for storm waters or surface drains to maintain uninterrupted service. Free access will be provided to all fire hydrants, water meters, and private drives during the course of construction. The. contractor will be required to provide and maintain at all times during construction ample means and devices which will promptly remove and properly dispose of all water from any source entering the excavations or other parts of the work. The contractor will also be required to comply with the provisions of the District's NPDES permit in disposing of water from the work. The geotechnical investigation will identify those areas where groundwater is observed in borings and comment on methods of dewatering which might be employed. The specifications will require that all excavations be backfilled after pipe has been installed, with the relative r VI-1 r r compaction required by the governing agency or a minimum of 90 percent below the street zone and 95 percent in the street zone obtained as determined in accordance with ASTM D 1557 or Test Method No. Calif. 216. Compaction will be obtained by mechanical means, water jetting, hand tamping, or a combina- tion of these methods. r B. REMOVAL AND RESURFACING OF STREET PAVEMENT AND SURFACES Street pavement and surfaces will be removed for installation of the pipe and replaced to the requirements of the agency r having jurisdiction over the right-of-way. All pavement cuts will be neat and straight along both sides of the trench and parallel to the alignment of the pipe to provide and r unfractured and level pavement joint for bonding existing surfacing with pavement replacement. Concrete pavement, including cross gutters, curbs and gutters, sidewalks, driveways, and concrete surface of whatever nature, will be sawcut to a minimum depth of 1-1/2 inches prior to removal, in accordance with the specifications. Replacement shall be in kind and consist of Class A Portland cement concrete. „y Aggregate base and asphalt concrete mixes for pavement replacement shall conform to the standard specifications of the jurisdictional authority. r During the course of construction, all pavement removed for trenching operations shall be replaced with temporary paving after compaction is completed or within three days after the installation of the pipe, whichever comes first. Temporary paving will be maintained and a smooth, traversable surface will be available at all times for vehicular traffic. Effective dust control will also be maintained throughout the r job by the contractor. Use of water or dust palliative will comply with standard specifications. r C. UTILITY CROSSINGS All utilities which cross the pipeline trench will be protected in place, unless otherwise indicated for relocation on the plans. The contractor will be required to notify the utility owner and Underground Service Alert 48 hours in r advance of the construction crossing and coordinate the construction schedule with the utility service requirements. Where indicated on the plans, the contractor will provide reinforced concrete beams, concrete support walls, or other means to support utilities which are not self-supporting and lie within excavated areas. Where utilities are to be temporarily taken out of service and a portion of the facility removed, replacement shall be to the specifications and standards of the utility company. r VI-2 r r The trunk sewer facilities will be located within the street .. to provide clearance with domestic waterlines in accordance with the standards of the State Department of Health Services. r D. TRAFFIC CONTROL PLAN CONCEPT .. The basic construction/traffic control approach as pointed out in Section IV,Cl. , is to stipulate construction zone detouring of traffic from normal patterns in segments that will minimize inconveniences that result in major delays to the motoring public while allowing a contractor sufficient area in which to develop an efficient train of pipeline construction activities. Generally, construction of the r gravity interceptors will start at the downstream ends and work upstream. The force main, on the other hand, would start at the pump station and work downstream. The specifications will identify the limits of each construction zone/traffic detour phase and will stipulate the general direction of the pipeline construction. Restoration r of street improvements, including backfill, compaction, and the first lift of permanent paving will be specified to follow the pipelaying heading closely as it progresses forward so that traffic can be restored to normal patterns in each phase prior to proceeding to the next phase. The construction plans and specifications will require the .. contractor to develop detailed traffic detouring and signing plans for each phase for submittal to the City of Costa Mesa for approval prior to detouring traffic. The criteria upon which this plan is based and traffic control plans which are intended to illustrate the concept of the traffic control requirements will also be included in the plans and specifications for bidding purposes. They are intended to r serve as a guideline only and will not relieve the contractor of his responsibility for reparation and adequacy of the actual traffic control plan utilized. 'r Following is a listing of the construction/traffic control zone phasing limits with the conceptual vehicular traffic control criteria requirements proposed for each phase. r Parking will be restricted on each street where necessary. BAKER-GISLER INTERCEPTOR Gisler Avenue; Washington Avenue to Gibraltar Avenue One eastbound and one westbound lane will be maintained on the south side of the street at all times. r VI-3 r r Gibraltar Avenue; Gisler Avenue to Sumatra Place Gibraltar Avenue; Sumatra Place to Labrador Drive Street will be closed to through traffic. One lane on the east side of the street and controlled by a flagman during working hours will be maintained for access to the adjacent residences. .. Baker Street: General During the final design, detailed analysis of traffic volumes and turning movements will be made to determine final suggested lane configurations at various time intervals. Following are conceptual traffic lane requirements for the anticipated construction zone phasing along Baker Street. .. They are subject to revision should the analysis point to a more efficient use of the roadway. r Baker Street; Labrador Drive to College Street West of Harbor Boulevard one lane will be maintained for each direction of traffic. At Harbor Boulevard one left-turn lane .+ will be added on both the east and west sides of the intersection. r Baker Street; College Street to Loren Lane Two eastbound lanes will be maintained on the south side of the street at all times. Two westbound lanes will be .. maintained on the north side of the street during all non-working hours. During non-peak traffic periods the westbound lane closest to the center of the street will be closed and utilized for constructing activities. It will be returned for traffic during peak traffic periods and all non-working hours. .+ Baker Street; Loren Lane to Coolidge Avenue On the south side of the street two eastbound lanes plus one left-turn lane at Fairview Road will be maintained at all r times. In the center of the street two westbound lanes plus one left-turn lane at Fairview Road will be ' maintained during all non-working hours. During non-peak traffic periods the westbound lane adjacent to the pipeline will be closed and utilized for construction activities. It will be returned for traffic during peak traffic periods and all r non-working hours. Baker Street; Coolidge Avenue to Babb Street Baker Street; Corona del Mar Freeway to Bristol Street r The same concept of two eastbound lanes and at least one westbound lane at all times with a second westbound lane .r VI-4 r being added at peak traffic periods and non-working hours is ,. proposed in this phase as in the previous phase. Baker Street; Babb Street to the Corona del Mar Freeway Two lanes for each direction of traffic will be maintained at all times on the south side of the street while construction is taking place on the north side. BASER STREET FORCE MAIN Baker Street; Bristol Street to Red Hill Avenue r Two lanes for each direction of traffic will be maintained at all times on the south side of the street while construction is taking place on the north side. Airway Avenue Airport Loop Drive One lane will be maintained for each direction of traffic on the west and north sides of the street, respectively, while ,r the construction activities are confined to the other side of the street. FAIRVIEW RELIEF INTERCEPTOR Fairview Road; Baker Street to Paularino Channel Northbound traffic will remain in its normal patterns, including the two left-turn lanes at Baker Street. Two southbound lanes will be maintained during peak traffic periods and non-working hours, reducing one southbound lane during non-peak working hours only. Fairview Road; ;air Channel to Fair Drive Fairy ew Road; Fair Drive to Wilson street Southbound traffic will remain in its normal patterns on the west side of the median. Two northbound lanes will be maintained during peak traffic periods and non-working hours. During non-peak working hours the easterly northbound lane will be closed and utilized for construction, being returned for peak traffic periods and non-working hours. During the final design stage the City's hourly traffic counts will be reviewed to identify the hours of the peak traffic periods of each phase. In addition, the traffic flow at each intersection will be reviewed for specific requirements to be incorporated in the traffic control plan. r Construction signing used for the handling of traffic for Public convenience shall conform to the latest edition of the "Work Area Traffic Control Handbook" (WATCH) published by VI-5 r Building News, Inc. and the Caltrans "Manual of Warning Signs, Lights, and Devices for Use in the Performance of Work upon Highways, " which will be included in the specifications. In addition, the signing, barricading, and diverting of traffic shall be subject to the approval of the authority with jurisdiction over the street (City of Costa Mesa) . The contractor will be required to maintain a 24-hour emergency service to remove, install, relocate, and maintain warning devices. r 4I YI r VI-6 r SECTION VII PROJECT SCHEDULE A. TARGET DATES The March 13, 1985 agreement between CSD Nos. 1, 2, 3, 5, 6, 7, 11, and 13 and the IRWD sets forth the time frame by which District No. 14 will provide permanent trunk sewer facilities for transportation of its wastewater to Reclamation Plant No. 1. This serves as the controlling target date, calling for a permanent operational system by January 1, 1990. B. CONTRACT LIMITS An implementation plan was developed to enable the project facilities to be constructed within the time frame discussed above while maintaining a competitive bidding atmosphere. Construction contracts were established that would provide sufficient construction headings to meet schedule require- ments and provide contract sizes in terms of cost that will fall within the bonding capacity of many local contractors. Type of construction activities, such as gravity sewer versus force main, also entered in the analysis. Recognizing the administration responsibilities of the District, the number of contracts were, of course, kept to a minimum. Three construction contracts are proposed to implement the sewage ,r conveyance system. These contracts are: 1. Baker-Gisler Interceptor Districts Nos. 6, 7, and 14 includes construction of the gravity interceptor from Reclamation Plant No. 1 to the terminus of the force main from the Main Street Pump r, Station. 2. Baker Street Force Main Districts Nos. 7 and 14 includes construction of the force main from the Main Street Pump Station. 3. Fairview Relief Interceptor District No. 6 includes construction of the gravity trunk sewer in Fairview Road from Baker Street to Wilson Avenue. The amount of time allotted for construction of the contracts are based on the following assumptions: One and one-half months from award of contract to delivery of first pipe. r VII-1 r - Pipelaying rate would be 80 feet per day and no weekend construction. - Appurtenant features (manholes, siphon, and structures) would be installed concurrently. - one and one-half months allotted for pipeline testing and cleanup. C. PROJECT SCHEDULES Figure 5 sets forth the schedule for the three construction contracts proposed for the sewage conveyance facilities. The schedule shows the minimum practical duration for the design, bidding, and construction phases and does not allow for unexpected delays or unusually long permit processing or review periods by the various jurisdictional authorities. The City of Costa Mesa has indicated that no construction will be permitted along Baker Street from Thanksgiving until after New Year's. This provision should be included in the specifications for construction of the Baker-Gisler Interceptor. In addition, stipulating that construction of the 78-inch interceptor from Fairview Road easterly be done first (between July 1988 and Thanksgiving) would minimize �+ delay of the City's Baker Street rehabilitation project between Babb Street and Bristol Street. r u r r r VII-2