139 

 

ENERGY EFFICIENCY  

 

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

 

Energy audit/benchmarking conducted to identify priorities for energy efficiency improvements  

 

‘Energy teams’ established and individuals empowered within the utility for energy efficiency 
activities (e.g., an “energy advocate” or “energy champion”)   

 

Energy management-related training provided to plant staff 

 

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

Began in March 2012, the WRRF Energy Efficiency Project aimed to upgrade aging and inefficient 
systems to improve energy and operational efficiency and to avoid future capital costs, upgrade / 
replace the existing cogeneration system to utilize available bio-gas produced onsite and to maximize 
cost savings, upgrade existing Supervisory Control And Data Acquisition (SCADA) controls to maximize 
energy and operational efficiency for the entire facility, and procure the maximum available electricity 
and natural gas utility incentives. The City implemented seven major upgrades:  

1) Cogeneration System Upgrade,  
2) Headworks Replacement,  
3) Solids De-Watering System Upgrades,  
4) Variable Flow RAS Pumping and Controls Integration,  
5) Filter Tower Media and Controls Upgrades,  
6) Exterior Lighting Upgrades, and  
7) SCADA Systems Upgrade.  

Performance Measures & Results 

-

 

Approximate cost savings through energy efficiency savings and reduction in operation and 
maintenance costs (in 2013 dollars) $325,000/year $11,087,492 over 25-year equipment life  

-

 

Current investment in energy efficiency projects or activities, and anticipated savings $10 million 
investment  

-

 

Estimated return on investment 14%  

-

 

Estimated avoided emissions 1,000,000 lbs of CO2  

-

 

Estimated percent of the WRRF’s current electrical power demand covered by on-site 
cogeneration implemented through the WRRF Energy Efficiency Project  25%  

 

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)