What is Industrial Stormwater? 

Any stormwater (rain, flood waters, etc.) which comes into contact with materials or equipment used in, or produced from, industrial activities before leaving the industrial site is considered industrial stormwater. 

Any industrial facility which meets these criteria are subject to State and Federal regulations to maintain water quality by monitoring and managing potential pollutants through Best Management Practices (BMPs). Such pollutants may include heavy metals, oils, salts, or other chemicals. 

Simply put, industrial stormwater is ensuring good house-keeping practices on industrials sites to keep our waters safe and clean. 

Do You Need a Permit? 

Stormwater discharges associated with industrial activity are required to be covered under an NPDES permit. Any facility which primarily engages in activities designated by specific Standard Industrial Classification (SIC) codes or narrative activities defined in SC Reg 61-9 Section 122.26(b)(14), must apply for coverage under the Industrial Stormwater General Permit (IGP) or certify for a No Exposure Certification (NEC). These designated codes and activities are defined in 11 unique categories.  

You can view a description of Stormwater discharges associated with Industrial Activities to see if your facility requires a permit below. The Department may also designate other facilities as requiring a permit, particularly where there is a potential for stormwater contamination.  

Primary SIC Code and Narrative Activities 

Generally, the first step to determine permit eligibility is to determine your site’s primary SIC code. A facility’s SIC code(s) can be found on federal tax forms for the industrial facility. The federal forms which typically contain the SIC code(s) are the Schedule C or C-EZ, Form 1065, Form 1120, or Form 1120-S. Other locations to locate your SIC code are local business licenses, other permits issued by this agency, business registrations such as Dunn and Bradstreet, the Secretary of State’s Office, or through the Department of Commerce. Another code system called North American Industry Classification System (NAICS) is also commonly used, a site’s NAICS can help in determining it’s SIC code. 

You may use the following links to:​ 

Find your SIC code​ 

Convert NAICS code to a corresponding SIC code​ 

29 Sectors of Industrial Activities 

Narrative Activities 

If your facility has one of the narrative activities defined by Category i., you must apply for permit coverage regardless of facility primary SIC code. See below for an inclusive list of narrative activities: 

• Discharges resulting from spray down or intentional wetting of logs at wet deck storage areas
• Runoff from phosphate fertilizer manufacturing facilities that comes into contact with any raw materials, finished product, byproducts or waste products (SIC 2874)
• Runoff from asphalt emulsion facilities
• Runoff from material storage piles at cement manufacturing facilities
• Runoff from hazardous waste and non-hazardous waste landfills
• Runoff from coal storage piles at steam electric generating facilities
• Runoff containing urea from airfield pavement deicing at existing and new primary airports with 1,000 or more annual non-propeller aircraft departures  

Non-Regulated Activities 

The following activities are either not authorized to discharge, not eligible for coverage, or not required to seek coverage under the IGP. 

• Wastewater discharges or stormwater discharges comingled with wastewater from industrial sites are not considered stormwater discharges and require a separate NPDES permit.​
• Activities defined in category iii. and designated Sector J: Non-metallic Mineral Mining and Dressing are covered exclusively by the NPDES General Permit for Discharges Associated with Nonmetal Mineral Mining, SCG730000.
• Activities designed Sector H: Coal Mines and Coal Mining-Related Facilities and Sector I: Oil and Gas Extraction are excluded from coverage. After consultation with the Department’s Bureau of Land and Waste Management, it has been determined that it is highly unlikely for activities covered under these Sectors to be located in the state.
• Construction Activities defined in Category x. are covered under the CGP (NPDES general permit SCR100000).
• Wastewater NPDES permits which already cover the entirety of a site’s eligible industrial stormwater discharges waives the requirement to apply for a separate industrial stormwater permit.
• In addition, if your facility does not perform an activity associated with an applicable SIC code or defined narrative activity, no industrial stormwater permit is required, unless otherwise directed by the Department (Sector AD) 

Certify No Exposure 

If any and all industrial materials are located within a storm-resistant shelter and are protected from rain, snow, snowmelt, and/or runoff then a facility may certify for no exposure. These materials may include, but are not limited to: material handling equipment and activities, raw materials, intermediate products, by-products, final products, or waste products. Certifying as no exposure negates the need for coverage under the IGP, however a No Exposure Certification form and fee must be submitted every five years in place of the permit. Failure to maintain this certification or no exposure conditions constitutes noncompliance with the IGP, State, and Federal regulation. Certifying for No Exposure exempts your site from the following permit requirements:​ 

• creating and maintaining a stormwater pollution prevention plan​
• paying annual fees​
• submitting annual reports​
• monitoring​ 

Guidance Manual for Conditional Exclusion from Stormwater Permitting Based on ""No Exposure"" of Industrial Activities to Stormwater 

Assess for Pollutants 

All facilities are responsible for determining if their site contains any of the following significant materials or industrial activities as possible sources of pollutants. They must also determine if rain, snow, snow melt, or runoff ever come in contact with any of these materials. If so, the facility must obtain an Industrial Stormwater NPDES permit under the IGP. The facility may not certify for no exposure. 

Create a SWPPP 

A Stormwater Pollution Prevention Plan (SWPPP) must be developed prior to applying for permit coverage and placing an industrial facility into service. This SWPPP acts as a living document which can be updated to match facility conditions and serves as a guideline for maintaining compliance with the IGP, State, and Federal regulations. Each SWPPP must include the following information: 

• Stormwater Pollution Prevention Team
• Site Description​
• Summary of Potential Pollutants Sources
• Sampling Data
• Description of Control Measures
• Schedules and Procedures (including employee training, inspection schedules, and sampling schedules) 

Industrial Stormwater SWPPP Template  

Choose BMPs 

BMPs are best management practices used to prevent illicit discharges from facilities to ensure compliance with State and Federal regulations. Some of the most effective types of BMPs are simply good housekeeping and moving materials indoors in storm-protected facilities to prevent exposure to stormwaters. These can be considered non-structural BMPs. Other BMPs may be structural and installed outdoors where materials are exposed to stormwaters to prevent pollutant runoff. It is important to consider whether materials can be stored indoors or what BMPs may be appropriate if this solution is not feasible.  

Wherever possible, limiting exposure to stormwater is the most cost effective and reliable method of management. Non-structural BMPs must be implemented prior to applying for permit coverage, while structural BMPs may be installed within the first year after applying for permit coverage. 

Apply For, Modify, or Terminate Your Permit 

If your facility requires an industrial stormwater permit, you will need to complete and submit a NOI form. The 2022 Industrial General Permit (IGP) requires all permittees to submit NOI applications electronically. All electronic applications must be submitted through ePermitting for stormwater coverage. Previous versions or “.pdf” versions of the NOI form will not be accepted starting July 1, 2022. You must have an ePermitting account and have an original Certifier Agreement on file with SCDES to submit the request electronically. If you have not set up an account and submitted an original Certifier Agreement, please do so now. An ePermitting account is necessary before submittal of the Certifier Agreement. Your ePermitting account must be linked to your site to access the electronic forms.   

Permit applications and certifications are required to be conducted electronically, as per recent EPA ruling. Our state uses ePermitting for all Industrial Stormwater permitting.​ 

• ePermitting​
• Industrial ePermitting Instructions 

In order to submit these applications, facility owners and operators must also become certified to sign documents electronically by hand-signing and mailing an original copy of the Certifier Agreement to our office to keep on file. Only once the agreement is received will applicants be able to sign and submit documents electronically.​ 

Meet Requirements 

Once permit coverage is obtained for an industrial facility, it is the responsibility of the owner and operators to ensure that additional permit requirements are being met and recorded appropriately in their SWPPP. The following are additional requirements of industrial facilities: 

Employee Training 

Training should be sufficient enough to inform employees of safety procedures, BMP operation and maintenance, spill management, how to prevent contamination, discharge sampling and monitoring procedures, and emergency response to environmental hazards. 

Training should be conducted annually for any employee who play a role in the implementation of the SWPPP, who install, maintain, or inspect BMPs, who conduct discharge monitoring, or who work in any industrial activities covered by the permit. 

Employee training must be documented in the SWPPP by recording the name of the instructor and all attending employees and the date the instruction was given.  

Monthly Inspections 

At least one inspection of industrial sites must be conducted each month with more frequent inspections occurring for larger sites or sites with multiple significant materials or industrial activities. In addition, at least one inspection must be conducted for each runoff event that occurs on the site. 

Inspectors should consider: 

• Does the SWPPP match the current site conditions? (I.e. Are all materials located where they should be? Are all structural BMPs in place where they should be? Are all of the outfalls properly identified?)
• Have new significant materials or activities been added to the site that need to be recorded in the SWPPP and reported?
• Are the BMPs effective at controlling material and activity exposure and stormwater runoff?
• Are any visible contaminants seen in any stormwater during runoff events? 

Impaired Waters Assessment 

It is the responsibility of all industrial facilities to determine if their site discharges to any impaired waterbody. Each year, the facility must confirm the current status of their receiving waters by checking the list of impaired waterbodies for the State. If it is determined that a receiving waterbody has been listed on the most current 303(d) or TMDL list, the facility must begin monitoring for the corresponding pollutant of concern within 180 days following the listing of the waterbody.  

• current 303(d) and TMDL lists
• Assess Your Site for Impaired Waters 

Monitoring and Reporting 

Sampling and/or monitoring is required of all industrial sites to ensure that illicit discharges are not occurring from the site during runoff events. The type and frequency of sampling events may vary depending on the sector for which the facility is classified under. A minimum of one sample must be taken within 30 minutes, or as soon as practicable, of a measurable storm event leading to runoff from an outfall.  

There are four types of required monitoring which may apply to an industrial facility: 

• Quarterly benchmark monitoring
• Annual effluent limitations guidelines monitoring
• Impaired waters monitoring
• Other required monitoring as required 

All monitoring data collected must be submitted in an approved format. Only numeric effluent limitations data must be reported on a Discharge Monitoring Report (DMR) once per year. Benchmark monitoring results only need to be reported when specifically required. 

Numeric Effluent Limitations Based on Effluent Limitations Guidelines 

What Forms Will be Required?