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NPDES Industrial & General Surface Water Discharge Permits

Individual Surface Water Discharge Permits

The industrial surface water discharge permit is a combined state and federal permit under the National Pollutant Discharge Elimination System (NPDES). This permit is issued for industrial facilities that discharge to State surface waters. The permit is designed to meet federal effluent guidelines when applicable and also ensure the discharge satisfies State water quality sta​ndards.

All industrial, commercial or institutional facilities that discharge wastewater (or stormwater from certain facilities) to surface waters of Maryland may need this permit. Alternatively, an industrial discharge to the municipal wastewater collection system may require a pretreatment permit.

Wastewater Permits Interactive Search Portal

The Wastewater Permits Program maintains an interactive search portal which allows the general public to search for permits by facility name, location, permit number, and/or permit type.  Once the desired permit entry is located, users have the opportunity to click the "More Info" button to display a list of available documents for download including permit applications, final permits and fact sheets, draft permits up for public comment, and general permit registration letters.  

Electronic Reporting Rule

Per 40 CFR 127.16, all National Pollution Discharge Elimination System (NPDES) regulated entities must submit Discharge Monitoring Reports (DMRs) electronically via NetDMR.  Before you can submit official DMRs online using NetDMR, you must attend a training webinar, successfully complete account set-up, and submit example monitoring results electronically.

Industrial Individual Surface Water Discharge Permit Forms

Certification of Workers' Compensation Insurance Coverage

Pursuant to Section 1-202 of the Environment Article, before MDE may issue a license or permit to a business that might employ a covered employee, the business shall submit to MDE a valid workers' compensation insurance policy or binder. Businesses that are exempt from having to provide workers' compensation insurance under applicable provisions of the Labor & Employment Article may need to submit a Certificate of Compliance.  General permit NOIs contain a section for reporting of required information, but applicants for individual NPDES permit should use the following form as part of their application package: MDE/WMA/PER.069


Industrial General Discharge Permits

A general permit is developed and issued by the Maryland Department of the Environment to cover multiple facilities within a specific category. General permits offer a cost-effective and expeditious option for permittees to obtain coverage under NPDES and State discharge permits because a large number of facilities can be covered under a single permit. According to 40 CFR §122.28, general permits may be written to cover categories of point sources having common elements, such as: industrial storm water; facilities that involve the same or substantially similar types of operations; facilities that discharge the same types of wastewater; facilities that require the same effluent limitations or operating conditions; facilities that require the same monitoring where tiered conditions may be used for minor differences within class (e.g., size or seasonal activity); and facilities that are more appropriately regulated by a general permit.

The use of general permits allows the Department of the Environment to allocate resources in a more efficient manner and to provide more timely permit coverage. For example, a large number of facilities that have certain elements in common may be covered under a general permit without expending the time and money necessary to issue an individual permit to each of these facilities. In addition, the use of a general permit ensures consistency of permit conditions for similar facilities.


General Discharge Permits

Maryland's Industrial Permitting Program authorizes the following General Discharge Permits: 

  • Industrial Sources that Discharge Storm Water Only (MDE/WMA/PER.004) - This permit covers discharges of storm water from industrial facilities.
  • Discharges of Stormwater from Construction Activities​ - This permit covers discharges of stormwater and some other associated waters with construction activities.  It is required for all construction activities which have a land disturbance of 1 acre or greater.
  • Hydrostatic Testing of Tanks, Pipes and Other Non-Oil Containment Structures (MDE/WMA/PER.011) - This permit covers the following discharges: treated tank bottom wastewater from petroleum storage tanks to surface waters; wastewater from the disinfection or hydrostatic testing of pipes, pipelines or tanks; wastewater from draining or flushing of fire control systems; discharges from potable water systems resulting from the overflow, flushing, disinfection, hydrostatic testing, mechanical cleaning, or dewaters in of vessels or structure used to store or convey potable water; untreated "water" in excess of 10,000 gallons per day as a monthly average from water storage or distribution systems; and storm water discharges from petroleum storage tank containment structures.
  • Seafood Processing Facilities (MDE/WMA/PER.010) -  This permit covers wastewater from seafood processing operations including crabs, oysters and fish; auxiliary discharges limited to non-contact cooling water, ice machine drainage, steam or cooling coil condensate and inside crab shedding tray overflow; and storm water runoff associated with seafood processing facilities.
  • Surface Coal Mining and Related Facilities (MDE/WMA/PER.007) - This permit covers discharges of storm water runoff and ground water seepage to surface waters from surface coal mines, including active mining areas, access roads, coal reclamation areas and associated coal storage and loading areas (tipples).  This permit also covers storm water from independent tipples and coal preparation plants.
  • Discharges from Swimming Pools and Spas (MDE/WMA/PER.070 and MDE/WMA/PER.072)  This permit covers discharges to surface or ground waters of overflow, drainage (drawdown), filter backwash, and cleaning water from any public or private pool or spa including baptismal fonts.
  • Mineral Mines, Quarries, Borrow Pits, and Concrete and Asphalt Plants (MDE/WMA/PER.009) - This permit covers mineral mines, quarries, borrow pits, ready-mix concrete plants having wastewater discharges, and storm water from asphalt plants.
  • Discharges from Marinas including Boat Yards and Yacht Basins (MDE/WMA/PER.008) - This permit covers the following discharges from a Marina, including Boat Yard and Yacht Basin: storm water runoff from establishments involved in boat maintenance; wastewater from washing of boats and engines; non-contact cooling water and condensate discharge from ice machines, refrigeration units and other machinery; and bilge water collected and treated for discharge to waters of the state.
  • Discharges from the Application of Pesticides (17-PE)  - This permit covers operators located in Maryland involved in the application of a pesticide that results in an eligible discharge to waters of the state.  Eligible discharges include application of (1) biological pesticides or (2) chemical pesticides that leave a residue, when the pesticide application is for one of the following pesticide use patterns: Mosquito & Other Flying Insect Pest Control; Weed, Algae, and Pathogen Control; Nuisance Animal Control; and Forest Canopy Pest Control.

Additional General Permit Forms

Contact Information

Please contact the Department at (410) 537-3323 for more information.

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