How Aurora Protects Waterways

The Clean Water Act amendments of 1972 authorized the National Pollutant Discharge Elimination System (NPDES). Under the NPDES program, the Environmental Protection Agency (EPA) controls water pollution by regulating the discharge of pollutants from point sources -- individual discharge points, such as pipes or man-made ditches. The City of Aurora has two NPDES permits: one permit for its combined sewer overflows (CSOs); and one permit for the municipal separate storm sewer system (MS4).

CSO Permit

  • Aurora developed its EPA-mandated CSO Long-Term Control Plan (Volume 1, Volume 2, Revised Schedule 2011-04-25) and is working aggressively to implement the Plan. The City’s strategies for controlling CSOs include: modifying the overflow structures, constructing new storm sewers to reduce the amount of stormwater in combined sewers, installing green infrastructure to reduce the volume of runoff, and constructing additional storage and treatment facilities. Implementing the plan has cost the City $48.1 million so far and is expected to cost the City another $103.5 million (in 2019 dollars) by the time the scheduled projects are completed in 2030.
    • Projects already completed
      • River Street Sewer Separation (2009-2010)
      • Spring Street Sewer Separation (2010)
      • East Side Rain Gardens (2012)
      • Northeast Sewer Separation (2014)
      • Galena and New York Sewer Separation (2015)
      • Galena and Downer Sewer Separation (2016-2018)
    • Planned projects
      • CSO 01 Treatment and Storage
      • CSO 04 Pumping Station and Force Mains
  • Every six months, the City submits Progress Reports on the implementation of the Long-Term Control Plan to the IEPA with and Water Quality Monitoring Data.
  • The City and the Fox Metro Water Reclamation District work together to operate and maintain the combined sewer system in Aurora. In order to reduce the magnitude, frequency, and duration of CSOs, theRain Garden Captures Runoff City and the District established operational, maintenance, and inspection procedures for the combined sewer system, which are documented in the CSO Operational and Maintenance Plan and certified by this checklist. Together, the City and the District implement a range of best management practices (BMPs) designed to reduce the volume of pollutants entering the combined sewer system and also the number of CSOs that occur. These BMPs are described in the CSO Pollution Prevention Plan and certified by this checklist.  In order to inform the public of the location and occurrences of CSOs, the City and the District are working together to implement this CSO Public Notification Program. The annual public meeting summaries can be found here:
  • Use of the City’s sewer system, and connection to it, are regulated by Section 48-103 and Sections 48-131 through 48-142 of the Municipal Code.
  • The City submits monthly Discharge Monitoring Reports (DMRs) to the EPA. DMRs identify the location and date of recorded CSOs with an estimate of the duration of each CSO. They also present the results of water quality sampling performed at CSO 027.
  • The City is working to prevent basement back-ups and sanitary sewer overflows.  This CMOM Plan documents the resources and procedures used by the City to manage, operate, and maintain its wastewater collection system.
  • The City periodically evaluates the locations of its CSO discharges in order to determine which CSOs discharge to a sensitive area, using criteria established by the EPA.  This Sensitive Area Analysis documents the latest findings.
  • The Fox River Study Group is a diverse coalition of stakeholders dedicated to a cleaner, safer, and more beautiful Fox River.  The Fox River Implementation Plan (FRIP) provides a road map for addressing water quality impairments throughout the watershed and an Annual Report of the Study Group's progress is submitted to the IEPA each year.  The City of Aurora is a contributing member of the Study Group and is represented on the Board of Directors.  One specific recommendation of the FRIP for municipalities is to reduce the amount of phosphorus in stormwater runoff.  This worksheet estimates the total annual phosphorus load removed in the City by detention basins and street sweeping.

MS4 Permit

  • The MS4 permit requires the City to reduce stormwater pollution to the maximum extent practicable through six specific initiatives: (1) public education and outreach; (2) public involvement and participation; (3) illicit discharge detection and elimination; (4) construction site runoff control; (5) post-construction runoff control; and (6) pollution prevention for municipal operations.  The Stormwater Management Program describes what the City is doing to reduce stormwater pollution and how the City is monitoring water quality in its waterways.
  • At the beginning of each permit cycle, the City submits a Notice of Intent(NOI) to comply with the permit requirements. The NOI commits the City to meeting specific goals within the term of the permit. Each year the City submits an Annual Report describing the City’s progress toward meeting its goals.
  • Discharges and connections to the City’s storm sewer system are regulated by Section 48-103 and Sections 48-131 through 48-142 of the Municipal Code.