427 

 

 

Utilization of energy conserving operational methods (e.g., optimization of primary 
sedimentation to reduce utilization of pure oxygen) 

Energy management program established at Sacramento Regional Wastewater Treatment Plant 
(SRWTP) in 2005 to improve/reduce energy usage. Electric meters installed on key systems to gather 
usage info that was used to optimize use and forecast energy budgets.  

Comprehensive 3-, 5-, 7-year plant energy-usage audits: Identified energy streams at SRWTP by 
functional systems.  Accurate forecasting relies on multi-year trends of not only energy but also 
respective process variables (i.e. temperature, diversions, rainfall, and incoming flows).  

Energy Optimization and Budget Forecasting last reported to Board in 2012. Savings at that time was 
$400,000/year. Forecasted 20-year savings was $11.3 million.  

Energy-optimization improvements include: Energy-use monitoring, trending, and analysis; audits to 
identify energy-saving projects; BMPs developed for repair and replacement of inefficient equipment 
and systems; new control strategies and SOPs for energy-efficient operation under various 
seasonal/weather/ system maintenance conditions.  

Performance Measures & Results 

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Monthly/annual target, usage, and cost detail analysis Able to monitor fluctuations in energy 
usage. Any abnormal spikes researched and rectified.  

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5-year Energy Savings: Trends Anticipates $400,000/year savings due to efficiencies.   

   

ENERGY GENERATION & RECOVERY 

 

Indication of management commitment (e.g., standard operating procedures; board/executive 
management renewable energy conversion policy, including quantitative goals developed and 
shared with stakeholders)   

 

Internal energy sources evaluated (e.g., biogas, hydropower, heat in wastewater), and/or 
renewable energy sources evaluated on an ongoing basis (e.g., solar, wind, co-digestion)  

 

Recovery of digester gas in a combined heat and power (CHP) system, and boilers in place (for 
process and building heating)   

 

Conversion of digester biogas to electricity and heat, and/or transportation fuel Yes   

 

Solar panels, wind turbines, heat recovery, in conduit hydro, and/or hydroelectric power 
generation systems installed  

Capture nearly all biogas and recycle via a long-term commodities agreement with Sacramento 
Municipal Utilities District (SMUD) for use at Carson Ice-Gen Project. Buy back recycled energy as steam 
that is used instead of natural gas to heat digesters.   

Fats, Oils & Gas (FOG) enhancement fed directly to digesters to increase biogas production.  

Approximately 4 MW power-purchase agreement under negotiation with solar company that will cover 
8% annual energy used and mitigates CEQA greenhouse gas emission for EchoWater treatment plant 
upgrade project.   

Continued review of renewable-energy sources such as fuel cells, wind turbines, and green-energy 
vehicles.