Wastewater FAQs

1. What is industrial wastewater?

Industrial wastewater is defined as all wastewater from any manufacturing, processing, institutional, commercial, or agricultural operation, or any operation where the wastewater discharged includes significant quantities of waste of non-human origin. If your business only discharges waste from bathrooms, lunchroom sinks, showers, and other sanitary use, you do not need an industrial wastewater discharge permit.

2. Does my facility need an industrial wastewater discharge permit?

Generally, any business that generates industrial wastewater is required to apply for a permit from the local sanitation district or sewer authority before discharging to the sewer. Businesses that generate industrial wastewater that is discharged to a river, lake, ocean, or underground injection well require a separate permit under the National Pollutant Discharge Elimination System (NPDES), administered by the Environmental Protection Agency (EPA) and the state they operate in.

3. Are there any wastewaters from non-human sources that can be discharged without a permit?

Most sewer districts will allow businesses to discharge mop water, water from floor scrubbers,  vehicle wash water (except from commercial car washes), and condensate from air compressors without a permit, although written authorization is often required. Contact your local sewer authority to find out their requirements for these types of wastewater.

4. How do a apply for a permit?

Contact your local sewer authority to obtain the permit application forms, which are often available online. In addition to completing the forms, you can expect to gather and provide these additional documents for your application:

  • Copies of the last 12 months of water bills for each metered water supply at your place of business (including fire system, irrigation, and other water service meters).
  • If your business uses water from an on-site well, meter reading records that document the volume of water used at your facility
  • Plot plans showing the layout of your facility, location of process tanks and equipment, sewer lines, connection point to the sanitary sewer, and the sampling point)
  • Process descriptions and process flow diagrams to show how wastewater is generated at your facility
  • Water use calculations, showing how much water is discharged to the sewer after deducting sanitary flow, evaporation, boiler loss calculations, water carried out with your products, water used for irrigation, and other deductions that you can document
  • Laboratory analysis of a representative sample of your wastewater
  • Safety Data Sheets (SDS) for chemicals used in the processes that generate wastewater
  • If your facility is in one of EPA’s 
5. What a Baseline Monitoring Report (BMR), and how is that different from a normal permit application?

EPA has established effluent limitations for 35 industrial categories (as of now – this list can change), which are based on the type of production activity at your site. Specific regulations and effluent limitations are set for each industrial category. A BMR is a specific type of permit application that is submitted to your local sewer district that is designed to meet the federal permitting requirements.

The industrial categories that are currently regulated by EPA include:

  1. Aluminum Forming (40 CFR 467): EPA defines aluminum forming as "the deformation of aluminum or aluminum alloys into specific shapes by hot or cold working such as rolling, extrusion, forging, and drawing." Surface treatment and heat treatment of aluminum parts that are formed at the same plant site are subject to the Aluminum Forming Regulations and are not covered by the Electroplating and Metal Finishing regulations (40 CFR 413 & 433). Casting of aluminum that is subsequently formed at the same plant site is also subject to the Aluminum Forming Regulations. Discharge from the forming operation is not required to be subject to this regulation.
  2. Battery Manufacturing (40 CFR 461): Battery manufacturing encompasses the production of modular electric power sources where all or part of the fuel is contained within the unit and electric power is generated directly from a chemical reaction rather than indirectly through a heat cycle engine.
  3. Carbon Black Manufacturing (40 CFR 458): This category consists of facilities which manufacture carbon black by the furnace, thermal, channel or lamp processes. Only facilities which have been constructed or significantly modified since May 18, 1976, are regulated.
  4. Centralized Waste Treatment (40 CFR 437): This category consists of facilities that receive wastes from off-site for treatment.
  5. Coil Coating (40 CFR 465): EPA regulations state that "Coil coating consists of that sequence or combination of steps or operations which clean, surface or conversion coat, and apply an organic (paint) coating to a long thin strip or coil of metal."
  6. Can Making (40 CFR 465): This classification is a subcategory of coil coating and has been defined to be "the process or processes used to manufacture a can from a base metal, including aluminum and steel." This category applies to seamless cans only.
  7. Concentrated Animal Feeding Operations (40 CFR 412): This category regulates discharge from feed lots for cattle, dairy cattle, swine, sheep, turkeys, chickens, ducks, and horses.
  8. Copper Forming (40 CFR 468): This category regulates discharges resulting from the manufacture of formed copper and copper alloy products. The forming operations covered are hot rolling, cold rolling, drawing, extrusion, and forging. Ancillary operations which include surface treatment (pickling, tumbling, burnishing, alkaline cleaning, and surface milling), heat treatment, hydrotesting, sawing, and surface coating with molten metal are also covered by this regulation. Discharge from the forming operation is not required to be subject to this regulation.
  9. Electrical and Electronic Components (40 CFR 469): This category consists of all operations associated with the manufacturing of semiconductors, electronic crystals, cathode ray tubes, and luminescent materials except for sputtering, electroplating, and vapor plating operations.
  10. Electroplating (40 CFR 413): This category consists of electroplating, anodizing, conversion coating, electroless plating, chemical etching and milling, and the manufacturing of printed circuit boards. This category applies to existing job shops only.
  11. Fertilizer Manufacturing (40 CFR 418): This category applies to discharges from the manufacture of sulfuric acid, nitric acid (in concentrations up to 68%), ammonium sulfate by the synthetic process or by coke oven byproduct recovery, and mixed and blend fertilizers. It is only applicable to sulfuric and nitric acid manufacturing processes that have been constructed or significantly modified since December 7, 1973, and ammonium sulfate and mixed and blend fertilizer manufacturing processes that have been constructed or significantly modified since October 7, 1974.
  12. Glass Manufacturing (40 CFR 426): This category consists of manufacturers of glass containers, television picture tubes, incandescent lamp envelopes, and hand pressed and blown glass. Only facilities which have been constructed or significantly modified since August 21, 1974, are regulated.
  13. Grain Mills (40 CFR 406): This category applies to facilities that process corn, wheat, rice, or other grains into various products.
  14. Ink Formulating (40 CFR 447): This category applies to discharges resulting from the formulation of oil-base ink where the tank washing system uses solvents. It is only applicable to processes that have been constructed or significantly modified since February 26, 1975.
  15. Inorganic Chemicals Manufacturing (40 CFR 415): This category includes facilities involved in the manufacture of basic inorganic chemicals including alkalies and chlorine, industrial gases, and inorganic pigments.
  16. Iron and Steel (40 CFR 420): This category covers steel works, blast furnaces (including coke ovens), rolling mills, electrometallurgical products, steel wire drawing and facilities which produce steel nails and spikes, and steel pipes and tubes. This category does not include coil coating operations.
  17. Leather Tanning and Finishing (40 CFR 425): This category consists of the tanning, currying, and finishing of hides and skins into leather.
  18. Metal Finishing (40 CFR 433): This category consists of electroplating, anodizing, conversion coating, electroless plating, chemical etching and milling, and the manufacturing of printed circuit boards. This category applies to captive shops (owns 50 percent or more of the surface area finished), and all new source electroplating and metal finishing operations (those which began construction after August 31, 1982).
  19. Metal Molding and Casting (40 CFR 464): This category consists of the pouring or injection of molten metal into a mold with the cavity of the mold representing, within close tolerances, the dimensions the final product. This category includes aluminum, copper, ferrous, and zinc casting.
  20. Nonferrous Metals Forming (40 CFR 471): This category consists of the deformation of a metal (other than iron) or metal alloy (other than iron as the major component by weight) into specific shapes by hot or cold working, drawing, cladding and tube reducing.
  21. Nonferrous Metals Manufacturing (40 CFR 421): This category consists of plants that process nonferrous ore concentrates (primary) and scrap metals (secondary) to recover and increase the metal purity contained in these materials.
  22. Organic Chemicals, Plastics, and Synthetic Fibers (40 CFR 414): This category consists of facilities which manufacture organic chemicals, plastics, or synthetic fibers. Companies which simply formulate or package these materials are excluded.
  23. Paint Formulating (40 CFR 446): This category applies to discharges resulting from the formulation of oil- base paint where the tank cleaning is performed using solvents. It is only applicable to processes that have been constructed or significantly modified since February 26, 1975.
  24. Paving and Roofing Materials (40 CFR 443): This category consists of producers of asphalt paving and roofing emulsions, asphalt concrete, asphalt roofing materials, and linoleum and asphalt felt floor coverings. It is only applicable to facilities that have been constructed or significantly modified since January 10, 1975.
  25. Pesticide Chemicals (40 CFR 455): This category includes the manufacturing, formulating, packaging, and repackaging of pesticides.
  26. Petroleum Refining (40 CFR 419): This category includes operations which produce gasoline, kerosene, distillate fuel oils, residual fuel oils and lubricants, through fractionation or straight distillation of crude oil, redistillation of unfinished petroleum derivatives, cracking or other processes.
  27. Pharmaceutical Manufacturing (40 CFR 439): This category includes pharmaceutical manufacturing facilities which may use fermentation, extraction, chemical synthesis, mixing/compounding and formulation, or may conduct research.
  28. Porcelain Enameling (40 CFR 466): EPA defines porcelain enameling as "that sequence or combination of steps or operations which prepare the metal surface and apply a porcelain or fused silicate coating to the metal basis material."
  29. Pulp, Paper, and Paperboard and the Builders' Paper and Board Mills (40 CFR 430): This category includes pulp mills, paper mills, paperboard mills, and building paper and building board mills.
  30. Rubber Manufacturing (40 CFR 428): This category consists of manufacturers that reclaim rubber or mold, extrude, or fabricate rubber products, including latex products. It is only applicable to facilities that have been constructed or significantly modified since August 23, 1974.
  31. Soap and Detergent Manufacturing (40 CFR 417): This category consists of facilities which blend or package liquid detergents or manufacture dry detergents by spray drying, drum drying, or dry blending. Only facilities which have been constructed or significantly modified since December 26, 1973, are regulated.
  32. Steam Electric Power Generation (40 CFR 423): This category is composed of facilities that are engaged in the generation of electricity for distribution and sale, and use either fossil-type fuel (coal, oil, or gas) or nuclear fuel in conjunction with a thermal cycle that has a steam/water thermodynamic medium.
  33. Textile Mills (40 CFR 410): This category applies to the fiber preparation and manufacturing/process of the textile industry.
  34. Timber Products (40 CFR 429): This category consists of a diverse group of manufacturing plants whose primary raw material is wood and whose products range from finished products to hardboard and preserved wood.
  35. Transportation Equipment Cleaning (40 CFR 442): This category applies to facilities cleaning the interior of tank trucks and intermodal containers that transport chemical and/or petroleum cargos.
6. What is a FOG Permit?

FOG is a common term for the excess animal fats and vegetable oils that are generated during cooking and many food preparation steps. FOG enters the plumbing system through kitchen sinks and floor drains in food preparation areas. Over time, FOG sticking to the interior of pipes can lead to reduced hydraulic capacity or even a complete sewer blockage. When that occurs, the result will ultimately trigger a sewage spill.


Some sewer authorities have established separate permitting requirements for restaurants, food service establishments, and facilities that store, process, and use animal fats and vegetable oils. Contact your local sewer authority to see if this type of permit applies to your business.

7. What is a Slug Discharge Control Plan?

A “Slug Discharge” is a release to the sewer of any non-routine material, typically caused by an accidental spill or a non-customary batch discharge, which has a reasonable potential to cause interference, pass-through, or in any other way cause a violation of the owner’s discharge permit, local rules, or state and federal regulations. Businesses that have an industrial wastewater discharge permit are required to prepare a Slug Discharge Control Plan that describes the preventive measures in place to prevent a Slug Discharge, emergency procedures to implement in the event of a situation that could possibly result in a discharge to the sewer, and emergency notification to the sewer authority in the case of a Slug Discharge.

8. What are the monitoring requirements for my industrial wastewater?

Typically, industrial wastewater permits require the permittee to take samples of their wastewater and submit Self-Monitoring Reports (SMRs) to document the concentration of pollutants of concern in their discharge. These samples are usually 24-hour composite samples, but may be grab samples, depending on the parameter(s) and your facility’s specific permit requirements. A flow-rate measurement, based on meter readings, is included in the SMR. The frequency of monitoring can vary depending on the type of industry you are in, the volume of wastewater your business discharges, and your facility’s record of compliance with the discharge limits in your permit. Most businesses will submit an SMR on a weekly, monthly, or quarterly basis.

9. How do I submit SMRs?

It depends on the sewer authority that has issued your permit. Most sewer districts in California will provide you with SMR forms that are submitted either by fax or mail, although some have on-line reporting capability.

10. Are there fees for discharging industrial wastewater?

Nothing is free! You will be charged a capacity fee based on the volume of water your facility discharges each year, plus additional surcharges for other parameters that usually include Total Suspended Solids (TSS), Biological Oxygen Demand (BOD), and Chemical Oxygen Demand (COD). Usually, your annual fee for sewer discharges is based on the prior year’s discharge volume and the annualized surcharge for the other parameters, with quarterly payments due for the current year. At the end of the 12-month cycle, you may receive a credit or additional balance due if your wastewater volume and surcharge parameters are greater or smaller than the prior year, and the reconciled amount will be used to set your fees for the following year.

Some sewer districts calculate the annual reconciliation for you automatically, but others require the business to prepare an annual surcharge statement and submit it to the sewer authority (example, Los Angeles County Sanitation requires an Annual Surcharge Statement by August 15th each year for businesses that discharge more than 1 million gallons of water during the previous year).

11. How long is my permit good for?

Most industrial wastewater discharge permits are good for five years, although some districts require new permits every two years. Check with your local sewer district.

12. If I make changes at my facility, do I have to notify the sewer authority?

Generally, any changes to your processes that could affect the type of pollutants, volume of wastewater discharge, or that falls within one of EPA’s 35 industrial categories will require a new permit application. Also, if the volume of wastewater your facility routinely discharges varies by more than 25% (higher or lower) than the average daily permitted discharge amount, you will generally need to apply for a new permit.

13. What happens if I exceed my permit limits?

Expect to receive a written Notice of Violation! Some sewer districts may issue a Notice of Significant Non-Compliance (SNC), and publish your company’s name with other businesses with SNC violations in a public notice in the local newspaper.

14. Other than my own sampling, does the sewer district monitor my discharge?

Yes, you can count on it! Your company will be required to have a legal sampling point on the outside of your facility that is accessible by the sewer authority at anytime they choose to come and take a sample. Typically, they will mail you copies of their own sampling results, so you have records of when and how often they show up.

Sewer districts also routinely take samples from various locations in public roadways, particularly near industrial parks, to monitoring for pollutants from the general area. If excessive concentrations of pollutants are detected in these area samples, they will take progressive samples upstream until they determine the source and determine if one or more businesses is illegally discharging without a permit.