Master Plan
2023 Wastewater Collection System Master Plan Update
District’s 2023 Wastewater Collection System Master Plan was completed in December 2023 by V. W. Housen & Associates and accepted by the District Board on December 13, 2023. This updated Master Plan evaluated the District’s current wastewater collections system and 11 pump stations since last update in 2013. The Wastewater Collection System Master Plan will recommend short term and long-term capital improvement projects that will improve resiliency, functionality, and flexibility of District’s infrastructures, will reduce Inflow and Infiltration (I&I), reduces sanitary sewer overflows (SSO), and reduces required future maintenance. The Capital Improvement Program (CIP) identified in the Master Plan will have a budget of approximately $10M/year for the next 10 years to improve the District’s Wastewater Collection System. The Master Plan also covers Recycled Water System. A preliminary recycled water market assessment was conducted as part of the 2014 Market Survey, and in 2019 it was further refined to consider additional potential customers. The potential recycled water customers service were categorized into four service regions which will be designed and constructed in 3 Phases. Phase 1 (Bayfront Project) will construct an influent pump station and approximately 4,900-LF of influent pipeline and produce a maximum daily flow of 0.6 MGD with an allocated budget of $66.7M. Phase 2 would involve construction of a booster pump station at the intersection of Terminal Ave. and Del Norte Ave. with an allocated budget of $16.3M. Phase 3 will cover customers surrounding Downtown Menlo Park and east along Middlefield Road and Willow Road with an allocated budget of $31M. Phase 1 project is anticipated to take 3 years and completed in late 2026, with Phase 2 project to take approximately 10 years, and the Phase 3 project to occur farther along into the future as the District completes additional sewer improvements.
In 2011/12, the District completed a second flow monitoring program to document any flow reductions resulting from the Haven Avenue and other District projects. The hydraulic model was then recalibrated and results re-evaluated to determine whether Master Plan recommendations should be adjusted based on the updated information.
This Technical Memorandum (TM) discusses the 2011/12 flow monitoring data and how this information affected hydraulic model results. This TM also discusses a revised approach to the management and accommodation of wet weather flows, and includes the following sections:
• 2011/12 Flow Monitoring Program and Recalibration of Basin 2B
• Recalibration Results for District Service Area
• Revised Approach to Wet Weather Flow Management
• Updated Capital Improvement Program
• Next Steps
The primary purpose of this sewer collection system master plan (Master Plan) is to evaluate the District’s gravity sewer collection system under a specific design storm, using a computerized hydraulic model.
This Master Plan is comprised of eleven chapters, including a sample Capital Improvement Program which is updated and budgeted for annually. The Master Plan also recommends a schedule for maintenance-related replacements of the pipeline and pump station facilities.
The Master Plan was developed to meet the following objectives:
• Evaluate system wide flow characteristics to identify areas contributing to high inflow and infiltration (I&I);
• Assess the existing hydraulic capacity of the collection system, including pipelines and pump stations;
• Evaluate pipeline and pump station condition and replacement needs; and
• Develop a prioritized capital improvement program (CIP) and funding approach to provide an affordable and sustainable level of service to the District’s ratepayers.