National Pollutant Discharge Elimination System (NPDES)

The National Pollutant Discharge Elimination System (NPDES) is a federally mandated program established under Section 402 of the Clean Water Act. It is the goal of the NPDES Phase II program to preserve, protect and improve the Nation's water resources by controlling polluted storm water runoff, specifically with respect to small Municipal Separate Storm Sewer Systems (MS4s) and construction sites that ultimately discharge into local waterways without treatment.

Cook County Department of Transportation and Highways (CCDOTH) is classified as an operator of a MS4 under Phase II regulations and is required to develop a storm water management program. In accordance with NPDES requirements, the program is comprised of Best Management Practices (BMP) which address the following six minimum control measures:

Public Education and Outreach
Public Participation/Involvement
Illicit Discharge Detection and Elimination
Construction Site Runoff Control
Post-Construction Runoff Control
Pollution Prevention/Good Housekeeping

A general overview of MS4 permit requirements is as follows:

Develop and Submit a Storm Water Management Program (SWMP) comprised of BMPs and Measurable goals for the Minimum Control Measures
Submit a Notice of Intent (NOI) as a new MS4 Operator or as an existing permittee to be covered under current ILR40 permit
Changes to the SWMP must be included in the Annual Inspection Report along with program assessment and BMP assessment

CCDOTH NPDES MS4 Permit Documents

CCDOTH Notice of Intent (NOI) for Coverage under ILR40

General NPDES Permit ILR40

CCDOTH Storm Water Management Program

CCDOTH NPDES MS4 Annual Report: 2023-2024

CCDOTH NPDES MS4 Annual Report: 2022-2023

CCDOTH NPDES MS4 Annual Report: 2021-2022

CCDOTH NPDES MS4 Annual Report: 2020-2021

CCDOTH NPDES MS4 Annual Report: 2019-2020

CCDOTH NPDES MS4 Annual Report: 2018-2019

Public Education and Outreach Resources

MWRD Environmental and Water Resources Educational Brochures