Illinois State Overview

The state of Illinois recognizes the regulations of section 402 of the Clean Water Act (CWA); which outlines the National Pollutant Discharge Elimination System (NPDES) permitting program. The Illinois Environmental Protection Agency (IEPA) mandates permit authorization to any permittee engaging in discharges of stormwater associated with industrial activity from construction sites that result in the disturbance of one (1) or more acres of total land area, or less than one (1) acre of total land but part of a larger common plan of development or sale. In addition, this permit authorizes discharges from construction sites recognized as having the potential to violate water quality standards by contributing a significant amount of pollutants to water bodies of the state.

            *Note: This permit may only authorize stormwater discharge associated with industrial activity from a construction site that is mixed with a stormwater discharge from an industrial source other than construction, where:

            (a) The industrial source is located at the same site as the construction activity.

            (b) Stormwater discharges associated with industrial activity from the areas of the site where constuction activity is occurring are in compliance with the standards of this permit.

            (c) Stormwater discharges from industrial activity occurring in locations other than where the construction activity is occurring are covered by a separate NPDES or individual discharging permit.

The Illinois NPDES General Permit does not authorize coverage of discharges from construction sites where stormwater runoff related to industrial activity originate from the construction site post project completion and once final stabilization has been achieved. Additionally, stormwater discharges associated with industrial activity that are subject to an existing individual NPDES permit are not authorized to receive coverage under this general permit.