TO:
Honorable Mayor and Members of the City Council
THROUGH:
Bruce Moe, City Manager
FROM:
Erick Lee, Public Works Director
Katherine Doherty, City Engineer
Gilbert Gamboa, Senior Civil Engineer
SUBJECT:Title
Consideration of a Resolution Approving a Professional Services Agreement with PACE, Inc. for Final Design Services for the Voorhees Avenue and the Pacific Avenue Sewer Lift Station Projects at a Cost Not-to-Exceed $576,603 (Public Works Director Lee).
ADOPT RESOLUTION NO. 22-0077
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Recommended Action
RECOMMENDATION:
Staff recommends that City Council adopt Resolution No. 22-0077
1. Approving the Professional Services Agreement with Pacific Advanced Civil Engineering, Inc. (PACE) for final design services and preparation of construction bid documents for the Voorhees Avenue and the Pacific Avenue Sewer Lift Station Replacement Projects at a Cost Not-to-Exceed $576,603; and
2. Receiving the Basis of Design Reports (BODR) for the Voorhees Avenue, Pacific Avenue, and Poinsettia Avenue Sewer Lift Stations; and
3. Approving the removal of the Pacific Avenue Sewer Lift Station and proceeding with a gravity pipeline replacement design.
Body
EXECUTIVE SUMMARY:
The preliminary engineering studies prepared by PACE, Inc. for the Voorhees Avenue, Pacific Avenue, and Poinsettia Avenue Sewer Lift Stations identify improvements needed to provide greater emergency storage capacities, pumping capacities, and other enhancements for these three sites.
The recommended rehabilitation of the Voorhees station will require the construction of a new adequate emergency storage wet well, reintegration of the existing station’s dry vault structure, and installation of new mechanical and electrical equipment. An additional force main pipeline will be installed to provide system redundancy. This specific project is estimated to cost $4.3 million.
The recommended alternative for the Pacific station is a removal of the existing sewer lift station from service and replacing its function with a gravity pipeline. A present value analysis of this project was performed to determine its cost-effectiveness (Attachment). This analysis shows that the replacement of the pump station is cost-effective over the life span of the facilities, as the City will avoid costs of nearly $15 million over the next 100 years. The direct benefits of this alternative relate to a significant reduction in maintenance efforts, energy usage, and liabilities associated with the risk of sewer spill from operating a sewer lift station. The indirect benefits relate to eliminating the need for staff to continually maintain a sewer lift station in a residential neighborhood. This specific project is estimated to cost $5.4 million.
The recommended improvement for the Poinsettia station is a complete replacement with a new pump station. Poinsettia station will require constructing a new adequate emergency storage wet well and dry vault concrete structure and installing new mechanical and electrical equipment. An additional force main pipeline will be installed to provide system redundancy. This specific project is estimated to cost $3.5 million.
Approving the recommended agreement with PACE for final design services will allow this firm to prepare the final design and construction documents necessary to address the two most critical sewer lift stations, Voorhees Avenue and Pacific Avenue. The final design and preparation of construction bid documents for the Poinsettia Avenue sewer lift station will be developed at a later time under a separate engagement.
FISCAL IMPLICATIONS:
The design and replacement/upgrade of three Lift Station Improvement Projects (Voorhees Avenue, Pacific Avenue, and Poinsettia Avenue) are included as part of the proposed Five Year Capital Improvement Program (CIP) update for Fiscal Year 2022-2023 through Fiscal Year 2026-2027 with $12,556,669 budgeted in the Wastewater Fund. Previously, a preliminary design agreement for all three lift stations was executed with PACE, Inc. for a total not to exceed $490,725. The agreement under consideration with PACE, Inc. will cover the final design engineering necessary to construct the Voorhees and Pacific Avenue sewer lift stations for a total not to exceed $576,603. Sufficient funds are available within the budget for each project, as shown in the Budget and Expenditures summary table (Attachment). Final design engineering services for the Poinsettia Avenue sewer lift station will be awarded at a future date. Any fund balance remaining after design will be utilized for project construction.
BACKGROUND:
The City currently operates and maintains an extensive sanitary sewer system. The City’s existing wastewater collection system is comprised of a network of gravity sewer pipelines, lift (pump) stations, and force mains. The gravity system consists of approximately 81.6 miles (430,784 linear feet) of pipe and 2,086 manholes and cleanouts. The wastewater system also includes eight pump stations and 5,114 linear feet of associated force mains to lift and convey wastewater from the lower elevation areas to the gravity system. The City’s local sewer system connects to the Los Angeles County Sanitation District (LACSD) system, which provides regional wastewater conveyance and treatment services to the City and neighboring agencies.
Sanitary sewer lift (pump) stations are complex facilities with auxiliary systems designed to move wastewater from lower to higher elevations through a force main pipe. Pump stations must be monitored and maintained regularly to ensure a reliable operating condition. Key elements of lift stations include a wastewater receiving well (wet-well), often equipped with a screen to remove coarse materials; pumps and piping with associated valves; motors; a power supply system; an equipment control and alarm system; and an odor control system and ventilation system. Lift station equipment and systems are often installed in enclosed concrete underground structures. Underground sewer pump station concrete structures typically last 50 to 100 years, with internal mechanical and electrical equipment lasting 15 to 20 years.
In 1997, the City completed the rehabilitation of five sewer lift stations, including the Pacific Avenue, Palm Avenue, Meadows Avenue, Voorhees Avenue, and Bell Avenue stations. The project included the replacement of pumps and motors at each station and the installation of diesel-fueled emergency generator sets. The project also upgraded the ventilation and control systems.
In 2010, the City adopted a Wastewater Master Plan that analyzed various facilities and operations of the City’s existing wastewater collection system. The Wastewater Master Plan included a list of capital improvement projects that will enhance the system to meet established criteria, properly maintain the system assets, and replace the facilities that have reached the end of their useful lives. The 2010 Wastewater Master Plan identified six sewer lift stations requiring major rehabilitation. Among those, staff identified the Voorhees Avenue, Pacific Avenue, and Poinsettia Avenue stations as priorities.
The Voorhees Avenue, Pacific Avenue, and Poinsettia Avenue Sewer Lift Station structures were initially constructed in the early 1950s and have reached the end of their useful lives at nearly 70 years old. Mechanical and electrical upgrades were implemented approximately 25 years ago, around the late 1990s. Once their useful lives are exceeded, these facilities become less reliable, expensive to maintain, and are subject to failure.
DISCUSSION:
In October 2019, the City issued a Request for Proposals (RFP) for design services to upgrade and enhance three sewer lift stations, force mains, and associated appurtenances, including (Attachment):
• Voorhees Avenue
• Pacific Avenue
• Poinsettia Avenue
The RFP phased the project approach and delivery in two phases:
1. Preliminary design development of a Basis of Design Report (BODR) for each sewer lift station.
2. Final design and preparation of construction bid contract documents.
In April 2020, City Council awarded a contract to PACE, Inc. for the Phase 1 preliminary design development work to determine the preferred alternatives to upgrade and enhance the sewer lift stations listed above. PACE submitted the most responsive and comprehensive proposal. The firm’s assigned staff has highly relevant experience, and its proposal demonstrated a significant understanding of the critical project tasks and constraints. PACE has an in-depth knowledge of pumping applications, proposed improvement strategies for sizing new equipment to meet operational conditions, and has extensive pump station renovation experience for coastal cities, having prepared previous designs for the City of Redondo Beach and City of San Clemente.
Phase 1 of this project, the preliminary engineering design work, is now complete. PACE’s findings are detailed in the final draft Basis of Design Reports (BODR) for each sewer lift station (Attachment). The BODR is the first primary deliverable for the project design. It identifies improvements needed to provide greater emergency storage capacities, pumping capacities, and other enhancements for three of the existing sewer lift stations sites. Specifically, for the Pacific Avenue site, PACE was able to identify a viable alternative to remove the current station from service by constructing a gravity sewer main connection to an existing Los Angeles County trunk sewer gravity system, thereby significantly reducing the risk of sewer spill and the City’s operating and future capital replacement costs. The purpose of the respective BODR is to help the City identify and consider a practical and cost-effective upgrade option for each project site in following order of priority:
1. Voorhees Avenue Station (1360 Voorhees Avenue)
2. Pacific Avenue Station (2803 Pacific Avenue)
3. Poinsettia Avenue Station (1100 N Poinsettia Avenue)
At this time, staff recommends awarding Phase 2 for final design and preparation of construction bid documents for the two most critical sewer lift stations at Voorhees Avenue and Pacific Avenue. The original agreement with PACE, Inc. for the Phase 1 preliminary design scope expired on December 31, 2021, requiring a new agreement. The design fees for Phase 2 are based on the design concepts outlined in the BODRs to rehabilitate the Voorhees station in kind and removing the Pacific Avenue station from service and replacing its function with a gravity pipeline, further described below.
Some of the critical services that will be provided in Phase 2 include:
• Complete oversight of the project scope and administration, including progress and community meetings, project cost accounting, quality control, and adherence to the project schedule.
• Environmental compliance with CEQA exemptions and permitting.
• Construction plans, specifications, and estimates (PS&E).
• Construction engineering support, including bidding, review of requests for information (RFI), submittals, associated meetings, and record drawings.
Upon completing Phase 2 for Voorhees and Pacific Avenue sewer lift stations, the project team will present the final design to City Council for approval and direction to proceed with advertising and bidding. Staff will then revisit the Phase 2 final design and preparation of construction bid documents scope of work for the Poinsettia Avenue sewer lift station.
Voorhees Ave Sewer Lift Station Rehabilitation
Voorhees Ave Sewer Lift Station is a combined wet well and dry vault rectangular reinforced concrete box type underground facility located at the southeast corner of Voorhees Avenue and Rowell Avenue adjacent to residential and local school district properties. The pump station was originally constructed in 1953 and retrofitted in 1997. The Voorhees station serves a 103-acre tributary area consisting of low and high-density residential, general commercial, and public land uses (253 parcels). Due to the topography of the City and the invert elevations of nearby sanitary sewer infrastructure, conveying the wastewater flow by gravity is not feasible.
The recommended rehabilitation of the Voorhees station will require the construction of a new adequate emergency storage wet well, reintegration of the existing station dry vault structure, and installation of new mechanical and electrical equipment. The Voorhees station pumps wastewater through a force main pipeline a distance of approximately 1,300 feet to the intersection of Peck Avenue and Gates Avenue. An additional force main pipeline will be installed to provide system redundancy. The new force main pipeline would run north along Rowell Avenue from the pump station to 2nd Street and discharge into an existing gravity sewer. The old force main would remain available if the primary force main were taken out of service for maintenance or repair.
The new sewer lift station will provide added reliability and increase emergency storage for more response time. During construction, the existing sewer lift station needs to be operational for the most extended amount of time possible to avoid a costly temporary bypass.
Pacific Avenue Sewer Lift Station Alternatives
Pacific Avenue Sewer Lift Station is a combined wet well and dry vault rectangular reinforced concrete box type underground facility located in the westerly sidewalk area at 2803 Pacific Avenue between 27th and 31st Streets. The entrance to the underground station is located next to the driveway of the adjacent residential property. The pump station was originally constructed in 1953 and retrofitted in 1997. The Pacific Avenue station serves a 103-acre tributary area with low-density residential and general commercial land uses (884 parcels). The sewer flows generated in the north half of the tributary area are first transported by the Palm Avenue Sewer Lift Station before flowing by gravity to the Pacific Avenue station.
Due to the topography of the City and the invert elevations of nearby Los Angeles County sanitary sewer infrastructure constructed in 2000, conveying the wastewater flow by gravity is a viable alternative and can be implemented to eliminate the requirement for the complete rehabilitation of the station.
The recommended alternative is removing the existing sewer lift station from service and replacing its function with a gravity pipeline. PACE conducted design development meetings with the City’s engineering and operations staff and the County’s engineering staff on a preliminary gravity line concept plan. The alternative gravity pipeline option will require approximately 800 feet of micro-tunneling construction south along Pacific Avenue from the current station’s location to connect directly to the existing LA County trunk sewer pipeline located along Marine Avenue. The connection will be made by constructing a new 70-foot deep manhole structure on Ardmore Avenue adjacent to the Veterans Parkway (Attachment). After reviewing the concept plans, the County provided conditional acceptance of the proposed connection. As part of their acceptance, the County specified that it would not be assuming ownership, operation, nor maintenance of the new manhole and connection once completed and that the County would treat the connection as a “Trunk Sewer Connection,” meaning the City will have full ownership and responsibility of the new connection and appurtenance structure. The installation of the gravity line allows for the demolition and abandonment of the existing station. Replacing the current sewer lift station with a gravity pipeline would significantly decrease the risk of sewer spill and reduce the City’s operating and future capital replacement costs.
The other alternative available to the City, which staff does not recommend, would necessitate the rehabilitation of the existing sewer lift station. Rehabilitation of the Pacific station would require the construction of a new adequate emergency storage wet well, reintegration of the current station dry vault structure, and installing new mechanical and electrical equipment. The Pacific station pumps wastewater through a force main pipeline a distance of approximately 1,225 feet to the intersection of Ardmore Avenue and Poinsettia Avenue. An additional force main pipeline would be installed to provide system redundancy. The new force main pipeline would run parallel from the pump station to Ardmore Avenue and discharge into an existing gravity sewer. The old force main would remain available if the primary force main were taken out of service for maintenance or repair. The new sewer lift station would provide added reliability and increase emergency storage for more response time. During construction, the existing sewer lift station would need to be operational for the most extended amount of time possible to avoid a costly temporary bypass.
Poinsettia Avenue Sewer Lift Station Replacement
Poinsettia Avenue Sewer Lift Station is a circular combined wet well and dry vault type underground facility located in the easterly sidewalk area at 1100 Poinsettia Avenue south of Manhattan Beach Blvd. The entrance to the underground station is located in the driveway of the First Lutheran Church and school. The pump station was originally constructed in 1949 and retrofitted in 1995. The Poinsettia station serves a 25-acre tributary area with only low-density residential land use (152 parcels). Due to the topography of the City and the invert elevations of nearby sanitary sewer infrastructure, conveying the wastewater flow by gravity is not feasible.
The recommended improvement for the Poinsettia station is a complete replacement with a new pump station adjacent to and north of the existing station in the sidewalk parkway area. Poinsettia station will require constructing a new adequate emergency storage wet well and dry vault concrete structure and installing new mechanical and electrical equipment. The Poinsettia station pumps wastewater through a force main pipeline approximately 165 feet to Manhattan Beach Blvd. A new parallel force main pipeline will be installed to provide system redundancy. The old force main would remain available if the primary force main were taken out of service for maintenance or repair. The new sewer lift station will provide added reliability and increase emergency storage for more response time. During construction, the existing sewer lift station needs to be operational for the most extended amount of time possible to avoid a costly temporary bypass.
Planning Level Cost Estimates
The capital cost associated with the new sewer lift station facilities involves many factors, including:
• Wastewater quality, quantity, and projections
• Zoning and land use
• Alternatives for standby power sources
• Operation and maintenance needs and support
• Soil properties and underground conditions
• Required lift to the receiving (discharge) sewer line
• The need for an odor control system
• The severity of the impact of accidental sewage spill upon the local area
• Construction phasing and complexity
The most important factors influencing costs are the design lift station capacity and the installed pump power. The planning level cost estimates in the BODR were prepared in accordance with the Class 4 AACE International Cost Estimate Classification System, which has an expected accuracy range of -30% to +50%. The construction cost estimates have included a 15% contingency. Manhattan Beach is primarily occupied, and there are many existing underground utilities to consider. Therefore, the costs of replacing complex sewer facilities will be generally higher than in an undeveloped area with no construction complications. While these rates seem high, they are not uncommon for a project of this magnitude.
Lift Station Improvement Construction Cost Total Project Delivery
Voorhees Avenue Station $3.4 million $4.3 million
Pacific Avenue Station $4.7 million $5.4 million
Poinsettia Avenue Station $2.6 million $3.5 million
TOTAL $10.7 million $13.2 million
The planning level cost estimates for the Voorhees Avenue and Poinsettia Avenue stations are generally based on replacing the existing sewer lift station, new mechanical and electrical upgrades, and construction of a new force main pipeline. The planning level cost estimate for the Pacific Avenue station is based on removing the station from service altogether. The total project delivery costs include all capital and soft costs (i.e. construction, design, construction management, inspection, etc.) associated with the complete delivery of the project, including allowances for site restorations. It’s important to note that the total project delivery cost estimates for these three projects exceed the current budget of $12,556,669 by approximately $650,000. This gap in funding will be addressed in a future fiscal year after PACE, Inc. completes the Phase 2 work and provides updated, more refined costs estimates for the Voorhees Avenue and Pacific Avenue Lift Stations.
Removing Pacific Avenue Station from Service
The Pacific Avenue Sewer Lift Station can be removed from service with the micro-tunneling construction of an 800-foot 12-inch diameter gravity sewer pipeline that discharges to the County’s 36-inch trunk sewer at the Ardmore Avenue and Pacific Avenue intersection adjacent to the Veterans Parkway (Attachment). The estimated capital cost to construct the gravity sewer to remove the station from service is $4.7 million, with a total project delivery budget estimate of $5.4 million. A present value analysis of this project was done to determine the cost-effectiveness (Attachment). This analysis assumed that the useful life span of the proposed gravity and force main pipelines is approximately 100 years, and the useful life span of a sewer lift station is 33 years. Based on these assumptions, the station's 100-year present value for continuous operation is approximately $20 million. The 100-year present value for removing the sewer lift station is about $5 million based on the same assumptions. This analysis shows that the replacement of the pump station is cost-effective over the life span of the facilities.
It is important to note that while the difference in capital costs between the Pacific Avenue gravity pipe replacement alternative versus a lift station improvement is approximately $1.5 million, the useful life of a gravity sewer main is at least three or more times of a sewer lift station. Direct benefits to the City are a significant reduction in maintenance efforts, energy usage, and liabilities associated with the risk of sewer spill from operating a sewer lift station. The indirect benefit will eliminate the Pacific station in a residential neighborhood.
Construction Considerations
The project team is anticipating the following general impacts requiring coordination and mitigation during construction:
• Maintaining existing operation or temporary bypass provisions
• Construction Phasing
• Construction Staging
• Traffic Control for vehicles and pedestrians
• Coordination with special events, as required
Provisions for construction coordination and mitigation measures will be implemented in the final construction bid documents accordingly. The regular access and activities along the Veterans Parkway can continue while the project is being constructed. Construction activities can be curtailed during certain special events to minimize any disruptions.
Project Timeline
Following approval of the final design agreement, the anticipated schedule milestones for the project are as follows:
• Voorhees Station - Complete Final Design 2023
• Voorhees Station - Begin Construction 2024
• Pacific Station - Complete Final Design 2024
• Pacific Station - Begin Construction 2025
• Poinsettia Station - Complete Final Design 2025
• Poinsettia Station - Begin Construction 2026
PUBLIC OUTREACH:
No public outreach was conducted regarding this design services award. However, the project team will conduct community information meetings and send notices to residences adjacent to the work once the project progresses into the final design phase.
Furthermore, once the project progresses to the construction phase, public outreach will include construction update notices, special event coordination, electronic message boards, media coordination, traffic alerts, and updates on the City website.
ENVIRONMENTAL REVIEW:
The Phase 1 preliminary engineering BODR includes initial determinations for each site through a pre-screening Initial Study prepared to disclose and evaluate short-term construction-related and long-term operational impacts. Based on the Pre-Screening Initial Study analysis, no potentially significant impacts would occur from the operation of the proposed sewer pump stations.
The City will continue to review the proposed project for compliance with the California Environmental Quality Act (CEQA). The City anticipates that the appropriate CEQA environmental document for the project will be a Categorical Exemption pursuant to Section 15302 Class 2 of the State CEQA Guidelines for replacement or reconstruction of existing facilities within the same footprint, with the same proposed usage, and with the same capacity.
LEGAL REVIEW:
The City Attorney has reviewed this report and determined that no additional legal analysis is necessary.
ATTACHMENTS:
1. Resolution No. 22-0077
2. Agreement - PACE, Inc. (2022)
3. Agreement - PACE, Inc. (2020)
4. Location Map
5. Design Reports (Web-Links Provided)
6. Budget and Expenditures Summary
7. Pacific Avenue Gravity Pipeline Rendering
8. Present Avenue Present Value Analysis Summary