National Pollutant Discharge Elimination System Permits
The National Pollutant Discharge Elimination System (NPDES) permit regulates wastewater. There are two types of wastewater discharge controlled by NPDES permits - process and storm water. An NPDES permit may be required at one business for either type of wastewater or for both. You should determine whether you need an NPDES permit either for process wastewater or for storm water. You are required to obtain these permits prior to any discharge. The requirements for each one are discussed separately in the Steps below.
Step 1: Does my business discharge a wastewater requiring an NPDES permit?
Wastewater: almost any discharge of water that is generated from any process industry, manufacturing, trade, or business. The definition also includes any solid, liquid or gaseous waste; and all other substances whose discharge would cause water pollution or a violation of the effluent or water quality standards of the State. Toilet and hand washing waste is also defined as a wastewater.
If your business does not have a wastewater discharge as described above, you are not required to obtain an NPDES permit.
If your business does have a wastewater discharge as described above, you should proceed to Step 2.
Step 2: Is a permit required if my business has ONLY toilet and hand washing wastewater?
If the only wastewater your business discharges is toilet and hand washing wastewater and the discharge of toilet and hand washing wastewater is less than 1500 gallons per day, you are not required to obtain an NPDES permit. However, the Illinois Department of Public Health does regulate these discharges.
If the discharge from your business of toilet and hand washing wastewater is greater than 1500 gallons per day, you are required to obtain an NPDES permit.
Step 3: Does my business have a storm water discharge that requires an NPDES permit?
You need to go through Steps 4 and 5 to determine whether your business needs an NPDES permit for its storm water discharge. You will usually need to know the Standard Industrial Classification (SIC) code for your business to do this.
Step 4: Does my business have a SIC code for which NPDES storm water permits are required?
Storm water may also be considered a wastewater depending on the type of business in which you are engaged. The Standard Industrial Classification (SIC) Code or type of operation your business is engaged in will determine whether or not the storm water that discharges from your property will be considered a wastewater.
A listing of categories for which storm water permits may be required is contained in
- If your business has a SIC Code that is listed in Appendix 1, then you are required to obtain an NPDES permit. An NPDES permit is required if material handling equipment or activities, raw materials, intermediate products, final products, waste materials, by-products, or industry machinery are exposed to storm water. If you do not have these objects at your business exposed to storm water you are not required to obtain an NPDES permit, but you must submit a
No Exposure certification form.
- If your business has a SIC Code or operation that is not listed in
Appendix 1, then you are not required to obtain an NPDES storm water permit, unless you are violating water quality standards of the State.
Step 5: If my business has wastewater, does my business discharge it to the surface of the earth or to water on the surface of the earth?
This provision is very broad so that you can assume that any discharge that goes to surface water or the ground on your property, or that leaves your property, is included. However, wastewater that is applied to agricultural land for crop or soil benefit is not regulated by the NPDES program. The permits required for this type of activity are discussed later in this document.
Important Additional Information Concerning NPDES Permits
- You should be aware that a general NPDES storm water permit is available from the Bureau of Water’s Permit Section if you meet the criteria described in the general permit. A general permit is a standardized permit with pre-determined conditions for similar discharges. You can review a general permit and decide ahead of time whether to apply for it rather than for an individualized permit. A one-page application is available for most general storm water NPDES permits. The simplified permit is usually issued within 30 days of receipt of the application.
- If you are required to obtain an Individual NPDES permit from the Bureau of Water, you are required to make a timely application 180 days prior to a new discharge or expiration of the existing NPDES permit if you wish to renew the permit.
Step 6: Does my business need a Construction Site Storm Water Activity Permit if I'm constructing any building or related activity?
A general NPDES Permit for Storm Water Discharges from Construction Site Activities is required for any construction site that will result in the disturbance of soil of one or more acres total land area.
Disturbance of soil includes clearing, grading and excavation activities of 1 acre or more. Construction activities less than 1 acre must also obtain coverage if they are part of a larger common plan of development.
A Construction Site Permit must remain active until the construction site has been completely stabilized. "Stabilized" means that all soil disturbing activities at the site have been completed and a uniform perennial vegetative cover has been established on all unpaved areas; or equivalent permanent stabilization measures have been employed.
State Construction Permits
A water pollution control construction permit is required by state law for businesses with the potential to cause water pollution. This construction permit is required prior to constructing or modifying a facility. You can determine whether you need to obtain a construction permit by going through Steps 1 and 2 below.
Step 1: Will there be construction at my facility?
State construction permits are required if your business is constructing or modifying anything within one of the four categories listed below.
Construction is defined as the commencement of on-site fabrication, erection, or installation. The definition of modification is rather long and can be found in
Appendix 2. You should look carefully at this definition because it includes such things as an increase in the amount of wastewater discharge even if the increase is not due to any other physical change in the facility.
If you are planning on constructing or modifying at your business, you should determine whether what you intend to construct or modify falls within one of the four categories listed below.
- If what you intend to construct or modify falls within one of the four categories listed below, you are required to obtain a construction permit from the Bureau of Water prior to the construction or modification.
- If what you intend to construct or modify does not fall within one of the four categories listed below, you are not required to obtain a construction permit from the Bureau of Water.
Category 1: Treatment Works
A treatment works is a device used for collecting, pumping, treating, or disposing of wastewaters, or for the recovery of byproducts from such wastewater.
A treatment works usually discharges wastewater to the surface of the earth or to water on the surface of the earth. However, a treatment works may also recycle wastewater for other uses and not have a discharge.
Category 2: Pretreatment Works
A pretreatment works is a device used for collecting, pumping treating or disposing of wastewater, or for the recovery of byproducts from such wastewater, before the wastewater in discharged into a publicly owned sanitary sewer system. The sanitary sewer system conveys the wastewater to a publicly owned treatment plant for further treatment.
In addition to the exemption listed in Question 2 of this section, pretreatment works have an additional exemption which is fairly complicated and may require interpretation. This additional exemption is listed in
Appendix 3. If you need assistance interpreting or understanding this exemption, you can obtain assistance from the Bureau of Water’s Permit Section at (217) 782-0610 or you may obtain assistance from an environmental professional of your choice.
Category 3: Wastewater Source
Wastewater source is any discharge of wastewater, usually to a publicly-owned sanitary sewer system. Wastewater discharges to agricultural land for crop or soil benefit are also considered wastewater sources. Some examples of wastewater sources would be:
- A new business in an existing building with existing sewers that connect to a publicly-owned sanitary sewer. Your new business will be generating a wastewater which you will discharge through the existing sewer. This discharge would be considered a wastewater source.
- Land application and/or spray irrigation of wastewater (including wastewater sludges) to agricultural lands.
Category 4: Sewer
A sewer is defined as a stationary means of transport intended to transport wastewater from your business to a publicly-owned sanitary sewer system.
The portion of the sewer which requires a construction permit is that portion which runs from the boundary of your building to the point of connection to the publicly-owned sanitary sewer system.
Step 2: Do you fall under the exemption for treatment works, pretreatment works, sewers, and wastewater sources?
This exemption can apply only to businesses that generate toilet and hand washing waste.
If you generate any wastewater that is not toilet and hand washing waste, this exemption does not apply to your business, and you must obtain a permit.
The exemption is as follows:
Construction permits are not required for any treatment works, pretreatment works, sewer or wastewater source designed and intended to serve a single building and eventually treat or discharge less than 1500 gallons per day of strictly toilet and hand washing waste (otherwise known as domestic waste).
If you fit under this exemption, then you are not required to obtain a state construction permit from the Bureau of Water.
State Operating Water Permits
State operating permits are required for the use or operation of most treatment works, pretreatment works, sewers or wastewater sources for which a construction permit is required. You should go through the two questions below to determine whether you need a state operating permit from the Bureau of Water.
Step 1: Does my business need a state operating permit?
In the section called State Construction Permits, you determined if your business required a state construction permit.
If you were required to obtain a state construction permit (other than for a sewer), you will be required to obtain a state operating permit, unless you fit under the exemptions listed in Question 2 below. Operating permits for sewers are generally issued with the construction permit.
If you have existing treatment works, pretreatment works, or wastewater sources, you are required to have a state operating permit unless you fall under one of the exemptions listed in Question 2 below.
If you do not need a state construction permit for your business, you do not need a state operating permit for your business unless you intend to use land application and/or spray irrigation of wastewater (including wastewater sludges) on agricultural land.
Important Additional Information
- An operating permit issued by the Bureau of Water has a maximum life of 5 years.
- If you are required to obtain an operating permit from the Bureau of Water, you are required to renew that permit by its expiration date for continued operation of the permitted facility.
- If you meet the criteria for needing an operating permit, you are required to obtain the operating permit even if you did not obtain a construction permit.
Step 2: Is my business exempt from the requirement for a state operating permit?
A state operating permit is not required for the following even if a state construction permit was required.
- A treatment works whose discharge is covered by an NPDES permit; or
- A pretreatment works or wastewater source whose discharge to the publicly-owned treatment plant (usually owned by a municipality) has been authorized by a receiving publicly-owned treatment plant that has an approved pretreatment program.
You should identify the publicly-owned treatment plant to which the discharge from your business flows. Once this is done, you should contact the Bureau of Water’s Permit Section at (217) 782-0610 to identify publicly-owned treatment plants that have approved pretreatment programs. This will tell you if the publicly-owned treatment plant to which your discharge flows has an approved pretreatment program.
If the wastewater discharge from your business flows to a publicly-owned treatment plant with an approved pretreatment program, then a state operating permit is not required.
If the wastewater discharge from your business does not flow to a publicly-owned treatment plant with an approved pretreatment program, then a state operating permit is required.*
* For certain pretreatment works or wastewater sources, there are some additional, somewhat technical, exemptions. The rule containing these exemptions is in
Appendix 3 to this document. If you need assistance interpreting or understanding this exemption, you can obtain assistance from the Bureau of Water’s Permit Section at (217) 782-0610 or you may obtain assistance from an environmental professional of your choice.
Industries Which Require an NPDES Permit for their Storm Water Discharge
General Storm Water NPDES Permit for Industrial Activity
Definition of Modification
- Any physical change in a treatment works or pretreatment works which involves different or additional processes or equipment or which increases or decreases the capacity or efficiency of the treatment works or pretreatment works; or
- change in the number or location of points where effluent in discharged; or
- Any change in any components of a sewer system which alters the quantity of wastewater capable of being conveyed; or
- Any increase in quantity or strength of a discharge from any wastewater source, unless such increase does not exceed an upper limit specifically allowed by an existing permit granted by the Agency and does not involve any additional contaminants.
(This is taken from the definition in water regulations. See 35 Ill. Adm. Code 301.315 for the complete definition.)
Additional Permit Exemptions
Construction or operating permits are not required for those pretreatment works, and operating permits are not required for wastewater sources, discharging to a sewer tributary to a publicly owned treatment plant which will not:
- Discharge toxic pollutants, as defined in Section 502(13) of the CWA, or pollutants which may interfere with the treatment process into the receiving treatment plant or be subject to regulations promulgated under Section 307 of the CWA; or
- Discharge 15 percent or more of the total hydraulic flow received by the treatment plant; or
- Discharge 15 percent or more of the total biological loading received by the treatment plant as measured by the 5-day biochemical oxygen demand.
(This is taken from the definition in water regulations. See 35 Ill. Adm. Code 309.202(c) and 309.204(d) for the complete definition.)
You may obtain additional copies of this document, by contacting Illinois Department of Commerce and Economic Opportunity (DCEO) Small Business Environmental Assistance Program or the Office of Small Business at the Illinois EPA or by contacting the appropriate permit section:
DCEO Small Business Environmental Assistance Program
Illinois EPA Bureau of Air Permit Section
Illinois EPA Bureau of Land Permit Section
Illinois EPA Bureau of Water Permit Section
You may also obtain information or assistance from these sections by calling the above numbers.