Industrial process wastewater is wastewater generated during commercial or industrial activity, such as washdown or process clean-up, that becomes contaminated with regulated pollutants before it is discharged as a wastewater.

Stormwater contamination occurs during precipitation events at industrial facilities where the run-off picks up contamination that can adversely affect water quality.

The most important water contaminants created by human activities are microbial pathogens, nutrients, oxygen-consuming materials, heavy metals and persistent organic matter, as well as suspended sediments, nutrients, pesticides and oxygen-consuming substances, much of it from non-point sources, according to the World Water Assessment Program.

Industry creates more pressure on water resources from the impacts of wastewater discharges and their pollution potential than by the quantity used in production.

Mercury and lead from industrial activities, commercial and artisanal mining and landfill leachates threaten human and ecosystem health in some areas, with emissions from coal-fired power plants being a major source of the mercury accumulating in the tissues of fish at the top of fish trophic levels.

Options for industrial wastewater discharge include:

• Discharge to a municipal sewer system
• Direct discharge to surface water

Additional option for sanitary wastewater discharge:

• Discharge to a septic system

Regulatory Requirements

The Clean Water Act (CWA) requires facilities discharging to surface water to obtain a National Pollutant Discharge Elimination System (NPDES) Permit.
Local Sewer Use Ordinances regulate discharges to municipal sewer systems—pretreatment may be required.
The Safe Drinking Water Act (SDWA) regulates water discharged from municipal sewer systems.
Septic system discharges are governed most directly by the SDWA and regulated by local health departments.

Industrial Process Wastewater

Industrial process wastewater is any wastewater generated during a commercial or industrial activity that is likely to become contaminated with regulated pollutants before it is discharged.

Possible Sources of Industrial Process Wastewater

• Washdown operations
• Process clean-up
• Boiler/compressor blowdown
• Cooling tower water
• Water treatment system discharge
• Boiler water backflow
• Industrial Wastewater Discharges

Many facilities discharge wastewater to a municipal sewer, or Publicly-Owned Treatment Works (POTW).

Options for Discharging to a Municipal Sewer System (or POTW)

• POTW may allow discharges with no pretreatment
• When it is low volume with few pollutants
• Has good treatment system allowing for easy treatment of waste stream
• POTW may require pretreatment and/or applies a surcharge
• POTW must comply with their discharge permit
• May require hard-to-treat contaminants to be removed
• May offer to perform expensive treatments for a surcharge

Common prohibited discharges include:

• Fire or explosion hazards
• Wastewater outside an acceptable pH range
• Solids that could cause obstruction
• Discharges that could cause upsets at the POTW
• Extreme heat
• Toxic fumes or vapors
• Trucked or hauled pollutants, unless approved

Plants making discharges to municipal systems will be required to maintain certain records as well as meet certain reporting requirements. These reporting and recordkeeping requirements can be found either in the facility permits or the POTW ordinance. Some typical reporting requirements include test results and compliance certifications.

Other notifications include increased flow; changes in the system design or operation; or the existence of slugs, or bypasses. Be sure to check your plant permit and POTW ordinance for your plant’s specific reporting and recordkeeping requirements.

Under the Clean Water Act, discharging directly to surface water requires the need to obtain a National Pollutant Discharge Elimination System (NPDES) permit. Any facility that discharges industrial process wastewater directly to surface water is required to obtain an NPDES permit and to comply with all its conditions.

Conditions may include pretreatment systems, testing and reporting requirements, water quality requirements, and flow restrictions.

All manufacturing facilities need a Storm Water Permit unless:

• They are not one of the regulated SIC Code categories.
• All storm water runoff from industrial areas is contained on-site.
• All storm water runoff goes into a public sanitary sewer system which goes to a POTW.
• All storm water runoff goes to an already permitted discharge.
• There is no storm water runoff from industrial areas in which case you must apply for a “No Exposure Certification”.

The Storm Water Pollution Prevention Plan must identify the members of a Pollution Prevention Team. The team’s responsibilities must be clearly identified in the plan. These responsibilities include developing the Storm Water Pollution Prevention Plan and assisting with the implementation, maintenance, and revision of the Storm Water Pollution Prevention Plan.

The Storm Water Pollution Prevention Plan must also include a topographic and site layout map. The topographic map should include the location of the facility, surface water bodies, wells, seepage pits, and filtration ponds.

The site layout map should include storm water conveyance and discharge structures, an outline of storm water drainage areas for each outfall, paved areas and buildings, material storage, handling, and disposal areas exposed to storm water, and the locations of major spills and leaks that have occurred within the last three years. If you have a major spill after your Storm Water Pollution Prevention Plan is completed and that spill could affect storm water runoff, you’ll need to amend your plan to describe that spill. The topographic and site maps may be combined as long as all of the required elements are included.