Item 13 — original pdf

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Walnut Creek WASTEWATER TREATMENT PLANT Renewal and Expansion Capital Improvements Water & Wastewater Commission May 8, 2024 Charles Celauro, PE Assistant Director, Engineering Services 1 Agenda 1. Project History: Walnut Creek Wastewater Treatment Plant 2. Construction Manager at Risk (CMAR) Projects • Expansion and Enhancements • Primary Clarifier and Flow Equalization Basin Rehab 2 Project History 3 Project History WALNUT CREEK WWTP Treatment Capacity 1977 – 18 MGD 4 Project History WALNUT CREEK WWTP Treatment Capacity 1977 – 18 MGD 1987 – 40 MGD 5 5 Project History WALNUT CREEK WWTP Treatment Capacity 1977 – 18 MGD 1987 – 40 MGD 1990 – 60 MGD 6 6 Project History WALNUT CREEK WWTP Treatment Capacity 1977 – 18 MGD 1987 – 40 MGD 1990 – 60 MGD 2005 – 75 MGD 7 7 Project History WALNUT CREEK WWTP Treatment Capacity 1977 – 18 MGD 1987 – 40 MGD 1990 – 60 MGD 2005 – 75 MGD 2019 – Optimization and Facility Master Plan 8 8 Project History WALNUT CREEK WWTP Rehabilitation and Renewal Projects 2000 – Reclaimed Water 2002 – Headworks #2 2009 – Electrical Distribution 2013 – Reclaimed Water 2017 – Tertiary Filter 2019 – Secondary Treatment 2020 – Sludge Thickener 2020 – Pump Replacements 2021 – Plant Control & Network 2022 – Gas Scrubber 9 Current Projects WALNUT CREEK WWTP Primary & FEB Clarifiers Headworks #1 Influent Lift Station Expansion to 100 MGD 10 Construction Manager at Risk (CMAR) Projects 11 Collaborative Delivery Design → Bid → Build Construction Manager at Risk (CMAR) Owner Owner Engineer Design 100% Engineer Design 60-90% Contractor Competitive Low Bid Contractor Qualifications & Cost 12 12 Primary Clarifier & Flow Equalization Basin 13 Primary Clarifier and Flow Equalization Basin  CMAR Project Development Findings  Constructability Challenges  Project duration increased from 2 years to 5 years  Temporary wet weather bypass for continuous plant operation  Temporary and permanent heating, ventilation & cooling (confined space)  Rising costs for key electrical and mechanical equipment  Grout replacement  Structural crack repair  Increased Scope to Advance Expansion Project  Meter vault for plant continuous operation  Headworks #2 slide gates to isolate treatment trains and complexes  Odor control demolition for coordination with other plant improvements 14 Primary Clarifier and Flow Equalization Basin Requests for Council Action RCA CIP Project RCA Scope RCA Amount Walnut Creek WWTP Primary Clarifier and Flow Equalization Basin Rehab An amendment to Black & Veatch consulting engineering contract $17,000,000 Walnut Creek WWTP Primary Clarifier and Flow Equalization Basin Rehab An amendment to MGC Contractors CMAR construction contract $127,300,000 1 2 15 Expansion to 100 MGD and Enhancement  Renewal Projects  Headworks #1 renewal  Influent lift station  Expansion Projects  New 25 MGD with nutrient removal  Influent pipe  Outfall pipe  Treatment Conversion  75 MGD with nutrient removal  UV disinfection  Protection of Plant  Wet weather treatment facility  Flood wall Expansion to 100 MGD and Enhancement Requests for Council Action RCA CIP Project RCA Scope RCA Amount Walnut Creek WWTP Headworks Improvements An amendment to Carollo consulting engineering contract $9,000,000 Walnut Creek WWTP Influent Lift Station An amendment to CDM Smith consulting engineering contract $2,850,000 Walnut Creek WWTP 100MGD Expansion and Enhancement An amendment to AECOM consulting engineering contract $71,000,000 Walnut Creek WWTP 100MGD Expansion and Enhancement Selection of MWH Contractors to be the CMAR Contractor $900,000,000 1 2 3 4 17 Questions?