Three Types of Discharge, Three Different Regulatory Requirements
If you operate an industrial facility in Georgia, the water leaving your property can fall into three distinct categories: stormwater, wastewater, and treated wastewater. Each one is regulated differently, permitted separately, and has its own monitoring and compliance requirements.
Confusing them — or assuming one permit covers everything — is one of the most common compliance mistakes we see. Here is a clear breakdown of what each one means and how to know which applies to your facility.
Stormwater: Rain That Touches Your Operation
A stormwater permit regulates rainwater that falls on your facility and picks up pollutants as it flows across the site. This is not water you generate — it is precipitation that becomes contaminated through contact with your industrial activities, such as material storage areas, loading docks, vehicle maintenance areas, exposed raw materials, and paved or unpaved surfaces.
In Georgia, most industrial facilities are covered under the NPDES Industrial Stormwater General Permit (GAR050000). This permit requires a Stormwater Pollution Prevention Plan (SWPPP), routine facility inspections, quarterly visual assessments, annual benchmark sampling for parameters like TSS, pH, COD, and Oil & Grease, and quarterly Discharge Monitoring Reports (DMRs).
The approach with stormwater is prevention — you use Best Management Practices (BMPs) to keep pollutants from reaching the stormwater in the first place.
Wastewater: Process Water Your Facility Generates
Wastewater is water your facility creates and contaminates through its industrial operations. This includes truck washout and equipment cleaning water, cooling water, rinse water from parts cleaning or surface finishing, and any other process water that has been used in your operations.
Untreated wastewater cannot be legally discharged to surface waters. It must either be collected and hauled to an approved disposal facility, discharged to a publicly owned treatment works (POTW) under a pretreatment agreement, or treated on-site before being discharged — which is the third category.
The key distinction from stormwater: wastewater is water you use and contaminate through your process. Stormwater is rain that picks up contamination on its own as it moves across your site.
Treated Wastewater: Process Water That Has Been Treated for Discharge
Treated wastewater is industrial process water that has passed through an on-site treatment system to reduce pollutant concentrations before being discharged to surface waters through a permitted outfall.
Common treatment systems at industrial facilities include multi-stage settling basins, recycled water storage ponds, filtration systems, pH adjustment systems (CO2 injection or acid dosing), and oil-water separators. At a ready-mix concrete plant, for example, truck wash water and mixer cleaning water flow through settling basins to remove solids and a pH adjustment system to bring alkalinity into range before the treated water is discharged.
Discharging treated wastewater requires an Individual NPDES Wastewater Permit or coverage under an applicable NPDES General Permit (such as GAG300000 for certain facility types). These permits include specific numeric discharge limits for pollutants like TSS, pH, Oil & Grease, and potentially nutrients, regular sampling and laboratory analysis, DMR submissions to Georgia EPD, and requirements for treatment system operation, maintenance, and recordkeeping.
The approach with treated wastewater is treatment and monitoring — you must treat the water to meet specific permit limits and prove it through regular sampling and reporting.
Side-by-Side Comparison
Stormwater
- Source: Rainfall contaminated by contact with industrial activities
- Permit: NPDES General Permit GAR050000 (industrial stormwater)
- Approach: Prevention through BMPs
- Monitoring: Quarterly visual assessments, annual benchmark sampling
- Key document: Stormwater Pollution Prevention Plan (SWPPP)
Wastewater (untreated)
- Source: Process water generated by facility operations
- Permit: Cannot be discharged untreated — must be hauled, sent to a POTW, or treated on-site
- Approach: Containment, disposal, or treatment before discharge
- Monitoring: N/A until treated and permitted for discharge
- Key document: Disposal records or pretreatment agreement
Treated Wastewater
- Source: Process water that has been treated through an on-site system
- Permit: Individual NPDES Permit or General Permit (e.g., GAG300000)
- Approach: Treatment to meet specific numeric discharge limits
- Monitoring: Regular sampling and lab analysis at permit-defined frequencies
- Key document: Permit-specific monitoring schedule and DMRs
Why This Matters for Your Facility
The most common problem we see is facilities discharging process water — treated or untreated — under a stormwater-only permit. A stormwater permit does not authorize discharge of industrial process water. If wash water, treatment system overflow, or any other process water reaches surface waters without the proper wastewater permit, that is an unpermitted discharge, and Georgia EPD treats it as a violation.
The reverse is also true. Having a wastewater permit for your treated process discharge does not cover your stormwater. Industrial stormwater that contacts your operations is regulated separately.
Can a Facility Need Multiple Permits?
Yes — and many do. A ready-mix concrete plant is a good example. It may need an industrial stormwater permit (GAR050000) for rainfall runoff across the yard, and an NPDES wastewater permit for treated wash water discharged from its settling basins. These are two separate permits with different monitoring, reporting, and compliance obligations.
BES works with facilities that need one, two, or all three situations addressed. We help you figure out which permits apply, prepare the applications, set up monitoring and recordkeeping, and keep you in compliance.
Not Sure What Applies to Your Facility?
If you are not sure whether your discharge is stormwater, untreated wastewater, or treated wastewater — or which permits you need — that is a common and valid question. The answer depends on where the water comes from, how it becomes contaminated, whether it is treated before discharge, and where it goes. BES can evaluate your site and give you a clear answer.
Phone: 770-359-9271
Email: info@bowenenvironmental.com
