339 

 

MMSD contracted with CH2M in 2010 to conduct a greenhouse gas (GHG) inventory that included the 
District’s water reclamation facilities, conveyance system, and other related District-owned and 
controlled facilities and programs. The inventory was undertaken in support of MMSD’s commitment to 
consider the depletion rate of nonrenewable resources and use those resources in the most productive 
and beneficial way possible to forestall or avoid complete exhaustion of those resources. The GHG 
inventory provides the District with information to develop future strategies for efficiently managing 
those resources that produce GHG emissions and will be able to be updated once the data management 
tool mentioned in the prior box entry is launched. 

A project is underway to improve the efficiency of the lighting system at the Jones Island and South 
Shore Water Reclamation Facilities. All existing indoor and outdoor lighting will be evaluated for possible 
upgrade if the upgrade will positively impact energy savings, maintenance, and labor productivity.  

JIWRF Aeration System Upgrade Capital Project replaced 5500 horsepower (hp) 40 year old process air 
compressors with a new 4500 hp Siemens high efficiency STC-SO SF014.0 single stage compressor.  The 
new compressor has operated most of the time since early 2015.  The new Siemens compressor 
installation includes a Siemens 4500 hp variable frequency drive, which allows the compressor to 
operate at high efficiencies over an output range of 55,000 scfm to 103,000 scfm. 

Performance Measures & Results 

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Decrease in energy demand with installation of new, energy efficient Process Air Compressors 
(PAC): Tracking of energy savings: old PAC used 31 Kw/scfm; new PAC uses 26 kw/scfm; 
KW/month for old Vs new PAC 3 MW to 2.5 MW; MW Plant Electric Load (Dry Weather) Old PAC 
11 MW, new PAC 10 MW. 

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Impact on fuel savings from use of  alternative fuel vehicles  and “eco-driving” training for field 
staff: First year of these combined programs saved MMSD $4000.  

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Reduction of greenhouse gas (GHG) emissions: Recommendations from the energy calculation 
and GHG scenario planning tools will be considered and implemented as warranted and data 
collected to track the subsequent reduction of GHG. 

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Continue feasibility studies for 19 prioritized recommendations/actions detailed in Energy Plan 
to meet 2035 Vision: The Energy Integration Team will continue to meet every six weeks for 
progress reports on prioritized recommendations and to detail next steps.  

 

 

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