Combined Sewer System

combined sewer_thumb.jpg What is a Combined Sewer?

A Combined Sewer is a type of sewer system that collects both sanitary sewage and stormwater runoff in a single pipe system. Combined Sewer Systems can cause serious water pollution problems due to combined sewer overflows, which are caused by large variations in flow between dry and wet weather conditions. This type of sewer design is no longer used in new construction, but many of the older areas still utilize this type of system. The Village of Lemont has dedicated itself to going into some of the more historic areas and separating the combined systems into separate, sanitary and storm systems.

Monthly CSO Readings

CSO Notices

IEPA Notice of Intent Construction Discharge Permit
MS4 Co-Permittee with DuPage
DuPage County Notice of Intent
DuPage County and Village of Lemont NPDES Intergovernmental Agreement
Lemont Combined Sewer Overflow (CSO) Public Information Handout
Soil Erosion and Sediment Control Public Information Handout
DuPage County Storm Water Management Plan

EPA Website

Illinois EPA Website
MWRDGC Combined Sewer Overflow Reporting

DuPage County Storm Water Management

Illinois EPA Division of Water Pollution Control
Annual Facility Inspection Reports

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National Pollutant Discharge Elimination System Permit IL0039551
National Pollutant Discharge Elimination System Permit ILR400497

DuPage County Annual Permit
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