Central Contra Costa Sanitary District
Designed a phased charging infrastructure roadmap to keep a wastewater utility's electric fleet charged & emergency ready
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Summary
Central Contra Costa Sanitary District (Central San) collects and treats wastewater each year for nearly 500,000 residents and 15,000 businesses across central Contra Costa County. Keeping its 1,500-mile sewer system and Martinez Treatment Plant running depends on a fleet of more than 100 vehicles, many of which must be ready to respond to emergencies at any hour. Facing California’s Advanced Clean Fleets (ACF) regulation and its own Net Zero commitments, the District selected Optony to develop a 15-year Fleet Electrification Strategic Plan that moves the fleet to zero emissions without compromising emergency response. Optony has since stayed on as the District's on-call electrification advisor.
The Challenge
Wastewater utilities face a particularly demanding version of the fleet electrification challenge. Much of Central San’s fleet is specialized medium- and heavy-duty vehicles, such as vacuum, dump, and bucket trucks, with limited or no zero-emission replacements on the market. Vehicles are spread across the Collection System Operations (CSO) Division, the Martinez Treatment Plant, and remote pumping stations, each with different duty cycles and electrical capacity. And because crews respond to sewer overflows and other emergencies around the clock, any charging strategy has to guarantee that critical vehicles are charged and ready when the call comes.
At the same time, ACF requires 50% of the District’s new medium- and heavy-duty vehicle purchases to be zero-emission, rising to 100% in 2030. Central San needed to understand which compliance pathway made the most sense, which vehicles qualified for exemptions, and what electrification would actually cost. Staff also needed a clear way to navigate a crowded landscape of utility programs, incentives, and procurement models, and to bring the Board, employees, and peer agencies along, many of whom had real concerns about EV range, charging availability, and whether electric vehicles could do the same work as the existing fleet.
Our Approach
Optony’s multidisciplinary team of energy program managers, EV and energy systems analysts, and electrical engineers tailored to the operational realities of a wastewater utility that never stops running.
The team evaluated EV suitability for over 100 studied fleet vehicles, modeled total cost of ownership and lifecycle greenhouse gas emissions, and built a 2025–2040 replacement timeline aligned with ACF requirements and exemptions. Using its proprietary Load Profile Builder tool, Optony modeled charging demand by vehicle category and duty cycle to right-size charger quantities and power levels at each site. A two-day on-site electrical assessment then informed preliminary site designs for the CSO Division, the Martinez Treatment Plant, and four key pumping stations.
100+
fleet vehicles analyzed for electrification
67
charging ports planned across six sites
83%
projected reduction in fleet GHG emissions by 2040
15-year
phased roadmap to a zero-emission fleet
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Solutions Delivered
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Fleet Electrification Planning
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Charging Infrastructure Planning & Site Design
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Advanced Clean Fleets Compliance
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Total Cost of Ownership
& GHG Analysis -
Funding & Incentive Strategy
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Utility Program & Procurement Support
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DER & Microgrid Evalutation
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Stakeholder Engagement
The Solution
The resulting Fleet Electrification Strategic Plan gives Central San a phased path to a zero-emission fleet that complies with ACF, supports the District’s Net Zero Initiative, and keeps costs in check. The Plan sequences vehicle replacements from 2025 through 2040, defers EV acquisitions until the first phase of chargers is in place, so no new vehicle arrives without somewhere to charge. It calls for 67 charging ports across six sites at a range of power levels, with dedicated chargers for emergency response vehicles and charging management software to keep peak demand and utility costs down. Optony also delivered a customizable Fleet Electrification Pro Forma app that lets staff adjust construction phasing, fuel price escalation, and inflation assumptions as the EV market evolves.
"Working with Optony on our fleet electrification strategy was a seamless experience. Their team is highly responsive, customer-focused, and easy to collaborate with. They took the time to understand our unique needs and delivered a tailored plan that is set up for success."
Rita Cheng, P.E. I Senior Engineer
Central Contra Costa Sanitary District
01
A fleet electrification roadmap and ACF compliance strategy for all 104 vehicles studied,
including evaluations of EV suitability, a 2025–2040 replacement timeline,
applicable ACF exemptions, and a recommended path to meeting Zero-Emission Vehicles (ZEV) purchase requirements.
Cost modeling projected approximately $200,000 in savings by 2040 and 83% reduction in fleet greenhouse gas emissions through electrifications.
02
A phased charging infrastructure plan with 67 charging ports at the CSO Division, the Martinez
Treatment Plant, and four key pumping stations. The Plan included preliminary site designs,
dedicated chargers for emergency response vehicles, and recommendations for charging management software to reduce peak demand and utility costs.
03
Continued on-call, trusted advisory and technical support, including a Charging-as-a-Service versus direct purchase evaluation, a hydrogen fuel cell vehicle assessment, a public and employee charging feasibility study, solar and battery storage microgrid evaluations for the Central Sanitation District (CSO) Division and Martinez Treatment Plant, and a maintenance facility and workforce readiness review.
Results & Impact
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