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Industrial Wastewater Discharge Permit

Industrial Wastewater is broadly stated to be any water carrying material and wastes that result from a business activity or from the development or recovery of a natural resource.

Wastewater Discharge Permit is part of a system designed to protect the sanitary sewer system and its workers, to prevent poor quality sludge and to protect the waters receiving the treated wastewater. Permits are issued at three levels:

  • Category 1—Primarily for significant volume users, users who discharge wastewater containing certain pollutants/users subject to specific federal discharge laws
  • Category 3—For users who discharge otherwise safe wastewater, such as restaurants
  • Category 6—For small volume dischargers of wastewater containing heavy metals or other pollutants

No business can discharge industrial wastewater to the sanitary sewer without a permit. Baltimore County Code requires industrial users to file an application for a Wastewater Discharge Permit. The permit year runs from August 1 through July 31. Renewal notices are sent in May. 

Permit Requirements

If you use water in the making of the product you sell, or in the service you provide, you probably will need a wastewater discharge permit if you put wastewater into the sewer. Water disposed of in other ways may be subject to other state and federal laws. Some types of businesses that are required to have a permit are obvious, such as industrial manufacturers, restaurants and laundries. For others, the requirement is not so clear, such as dry cleaners, doctor's offices and machine shops to name a few.

The basic factors considered in deciding whether a permit is required or not are:

  • Is water used in the business for other than domestic (sanitary) purposes?
  • Is the water disposed of to the sanitary sewer?

If you answered yes to both questions a permit is most likely required.


The annual permit fees are:

  • Category 1—$466
  • Category 3—$202
  • Category 6—$101

All companies classified as Significant Industrial Users pay the Significant User Fee that is computed based on the volume of wastewater discharged, but can be no more than $3,597, and is in addition to the basic permit fee.

Food Service Surcharges

Food service operations are subject to a food service surcharge, which is set at the following rates and effective dates:

  • January 1, 2017 = $1.5145
  • January 1, 2018 = $1.5599
  • January 1, 2019 = $1.6066
  • January 1, 2020 = $1.6547

These surcharges are per 100 cubic feet of consumption. A cubic foot of water is equal to 748 gallons.

About Significant Industrial Users

Significant Industrial Users are companies that:

  • Discharge at least 25,000 gallons of wastewater per average work day.
  • Are classified as a categorical user and have the ability to discharge toxic pollutants.
  • Discharge an annual average daily flow greater than five percent of the total annual average daily flow of wastewater received at the treatment plant.
  • Are found by the County, state or Environmental Protection Agency (EPA) to have a significant impact on the treatment plant, the quality of the sludge, the treatment plant's effluent, or emission quality, either alone or in combination with other contributing users.

Pollutant Limits

The following list identifies pollutants with specific limits set by the treatment plant. These and other pollutants may be further limited on a case-by-case basis or be set by the EPA based on industry category. If you are discharging or wish to discharge an unlisted pollutant to the sanitary sewer as part of the wastewater generated at your business, call 410-887-5348.

Cadmium0.21 mg/L
Chromium6.89 mg/L
Copper6.59 mg/L
Cyanide1.9 mg/L
Lead6.81 mg/L
Mercury0.01 mg/L
Nickel2.82 mg/L
Silver1.2 mg/L
Zinc17.85 mg/L
Fat or Oils100.0 mg/L
Total Toxic Organics2.13 mg/L
pH Range6.0 to 10.0 pH units

Fees for Exceeding Limits

If you discharge wastewater that exceeds the following test values you may be subject to Industrial Wastewater Surcharge:

  • Biochemical Oxygen Demand (BOD) greater than 300 mg/L
  • Total Suspended Solids (TSS) greater than 300 mg/L
  • Total Phosphorus (P) greater than 12 mg/L
  • Total Kjeldahl Nitrogen (TKN) greater than 30 mg/L

Contact Information

For additional information, call 410-887-5348.

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