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by about 1/3.  Efficiency efforts continue, with full-scale testing planned to implement a BNR 
configuration with potential to further reduce process energy demands. 

Energy generation is the next way to move towards energy sustainability.  Biogas has traditionally been 
used to provide process heat for the digestion process, with excess gas simply flared off as a waste.  The 
first step in optimizing this resource was to begin receiving compatible high-strength waste and co-
digesting it with sewage sludge to boost gas production.  Higher volumes of gas created better 
opportunities for more efficient larger CHP technologies that generate electricity and process heat for 
the anaerobic digesters.  A CHP facility has since been installed at the plant, including gas cleaning 
equipment and an engine-driven generator with engine cooling system heat recovery used to heat the 
anaerobic digesters.  With this installation, 70% of the existing energy used at the plant comes from 
biogas.  A second CHP unit is currently under design, with the goal of operating with no utility electricity 
during normal flow periods.  Other potential future projects include upgrading emergency backup 
generation with improved air emissions equipment, in order to meet wet weather energy demands. 

Watershed Stewardship 

The regulatory environment made a dramatic change about 15 years ago, when the TMDL program 
began replacing the historic use of technology-based effluent standards that had dictated POTW 
discharge limitations.  The badly underfunded and data-deficient program attempting to identify 
appropriate pollutant load allocations for the receiving stream watershed was fortunately designed to 
engage watershed stakeholders, who joined in a consortium to implement an adaptive management 
program to meet the stream use goals identified in the law.   

The District played a key role in identifying this need, and became a founding member of the DuPage 
River Salt Creek Work Group (DRSCW), with staff involvement on the executive level of the work group 
since its inception.  The District currently keeps a part time position dedicated primarily for coordinating 
DRSCW activities.  The DRSCW’s membership consists of POTW and MS4 owners as the core and 
principal funding source, with associate membership from activist groups, consultants, and other 
interested stakeholders.  The geographic area includes a roughly 360 square mile drainage area of 
urbanized headwater streams that are part of the Mississippi River Drainage Basin, 19 major POTW 
owners and 57 MS4 owners.  Stream uses of concern include aquatic life, primary contact, and aesthetic 
quality. 

The DRSCW conducts the key steps in adaptive management, including comprehensive routine 
monitoring and assessment, identification of stressors causing non-attainment, development and 
prioritization of restoration projects and activities with the best opportunities for moving towards 
stream use goals, and continuous evaluation of project and program effectiveness with monitoring 
results. 

The DRSCW has been successful in developing a $10 million stream restoration funding program for its 
POTW members that is incorporated into the NPDES permits of its POTW members.  In exchange for 
extended compliance schedules for accepting phosphorus limits needed to meet the State’s strategy to 
address nutrient losses to the MARB, POTWs will pool a significant portion of the delayed P-removal 
operating costs to address higher-priority stressors affecting the local watershed.  Project commitments 
include dam removal and habitat restoration projects that are expected to ‘move the needle’ towards 
meeting aquatic life goals in the watershed, as has been demonstrated with similar recent projects.