Aerobic Granular Sludge Project, Phase 1, Capital Project No. 2207 IEPA Project No. L17-6127

Four Rivers Sanitation Authority (FRSA) covers approximately 100 square miles of Winnebago County in northern Illinois.  FRSA serves over 290,000 people in the communities of Rockford, Loves Park, Machesney Park, Roscoe, Cherry Valley, New Milford, Winnebago, a portion of Rockton, and several unincorporated areas within Winnebago County.  FRSA owns and maintains a 1,126-mile network of gravity sanitary sewer lines that transport wastewater from residences, industrial sites, and other businesses to a wastewater treatment plant located at 3333 Kishwaukee Street, Rockford, IL. 

Project Description

Nutrient Removal Facility Improvements (Phase 2); Aerobic Granular Sludge-Phase I:  The implementation of 10 mgd of aerobic granular sludge (AGS) treatment facilities (secondary treatment), operating in parallel with existing secondary treatment facilities, to provide enhanced nutrient treatment. The facilities are part of the FRSA’s overall facility improvements plan for implementation of facilities to meet future effluent phosphorous limits as dictated by Special Condition 20 of its NPDES permit. The facilities include new concrete AGS reactors (four) and adjacent pipe gallery, AGS blower facilities for the AGS process, pumping facilities for waste flows from the AGS process, related site piping connections to upstream and downstream facilities, and all electrical, mechanical and instrumentation/control facilities supporting the facilities for a complete, operable system; and all necessary site work and restoration to make the project complete and operational together with any land or rights in land or other services necessary, useful or advisable to the contract and installation of the above (the “Project”). All in accordance with the plans and specifications prepared by engineers of FRSA; which Project has a useful life of 25 years or more.

Community Benefits

This project will supplement the existing activate sludge system and enhance nutrient removal. FRSA is making the improvements to help the Wastewater Treatment Plant run more efficiently and meet future NPDES limits. 

Funding for this project was provided by a low interest loan from the Illinois Environmental Protection Agency’s Water Pollution Control Loan Program (WPCLP).  The WPCLP is funded by both state and federal sources. 

For more information, please contact the FRSA Engineering Department at (815) 387-7660, visiting, 3501 Kishwaukee Street, Rockford, IL 61109.