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The City of New Orleans

Mayor Mitchell J. Landrieu

Municipal Separate Storm Sewer System (MS4) Program

Polluted stormwater runoff is commonly transported through Municipal Separate Storm Sewer Systems (MS4s), from which it is often discharged untreated into local waterbodies. To prevent harmful pollutants from being washed or dumped into an MS4, operators must obtain a NPDES permit and develop a stormwater management program

In conjunction with the  Sewerage & Water Board, Port of New Orleans, Orleans Levee District, Jefferson Parish and Louisiana Department of Transportation, the City of New Orleans is a co-permittee for this area’s MS4 permit. This Office acts as a coordination office  for the various City Departments that each play a role in  the City’s stormwater management program:

  • Mayor’s Office of Coastal & Environmental Affairs
  • City Planning Commission
  • Department of Safety & Permits
  • Department of Code Enforcement
  • Department of Sanitation
  • Department of Public Works
  • Department of Capital Projects
  • Department of Parks & Parkways
  • Mosquito, Termite & Rodent Control Board
  • Mayor’s Office of Neighborhood Engagement

Construction Site Compliance Requirements

  • If your demolition/ construction site is over 5 acres you will need to submit a Notice of Intent (NOI) – (form CSW-G) with the State.
  • If your demolition/construction site is  between 1 and 5 acres you will need a LA DEQ Stormwater General Permit  (LAR 200000)
  • If your demolition/construction site is between 1 and 5 acres you will also need to prepare and implement a Stormwater Pollution Prevention Plan (SWPPP). SWPPP must be completed and available for inspection on site prior to excavation.
  • For all other demolition/construction sites under 1 acre you will need to install and maintain Best Management Practices (BMP’s) in accordance with City Ordinance SECTION 103.17 CONSTRUCTION OR DEMOLITION PRIVILEGES and SECTION 103.18 DEMOLITION REQUIREMENTS. 

For all questions  regarding State permitting requirements please contact the Southeast Region Office of La. Department of Environmental Quality (LaDEQ) located in Harahan. 504.736.7739

The Environmental Affairs Division of the Sewerage & Water Board conducts free monthly training sessions for contractors on New Orleans Stormwater compliance. 504.942.3857

To report an issue or violation please call

311 to be connected with a City Department
52-WATER for Sewerage & Water Board 



  • BMP: Best Management Practice
  • BOD: Biological/Biochemical Oxygen Demand
  • CWA: Clean Water Act
  • DO: Dissolved Oxygen
  • DOT: Department of Transportation
  • IDDE: Illicit Discharge Detection and Elimination
  • LA = Load Allocation to NPS or to natural background sources
  • LPDES: Louisiana Pollutant Discharge Elimination System
  • MOS = Margin Of Safety
  • MS4: Municipal Separate Storm Sewer Systems
  • NOI: Notice of Intent
  • NPS: Nonpoint Source
  • O&M: Operation & Maintenance
  • PHF: Pesticides, Herbicides, and Fertilizers
  • POTW: Publicly Owned Treatment Works
  • SWMP: StormwaterManagement Plan
  • SWPPP: StormwaterPollution Prevention Plan
  • TMDL: Total Maximum Daily Load
  • WLA =Waste Load Allocation to point sources
  • WQC: Water Quality Certification
  • WWTP: Wastewater Treatment Plan


Best Management Practices (BMPs)

Schedules of activities, prohibitions of practices, maintenance procedures, and other management practices to prevent or reduce the discharge of pollutants to waters of the United States. BMPs also include treatment requirements, operating procedures, and practice to control plant site runoff, spillage or leaks, sludge or waste disposal, or drainage from raw material storage.

Hazardous Substance

Any substance, other than oil, which, when discharged in any quantities into waters of the U.S., presents an imminent and substantial danger to the public health or welfare, including but not limited to fish, shellfish, wildlife, shorelines and beaches (Section 311 of the CWA); identified by EPA as the pollutants listed under 40 CFR Part 116. Any substance, other than oil, which, when discharged in any quantities into waters of the U.S., presents an imminent and substantial danger to the public health or welfare, including but not limited to fish, shellfish, wildlife, shorelines and beaches (Section 311 of the CWA); identified by EPA as the pollutants listed under 40 CFR Part 116.

Municipal Separate Storm Sewer System (MS4)

A conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, or storm drains):

  • Owned and operated by a state, city, town, borough, county, parish, district, association, or other public body (created by or pursuant to state law) having jurisdiction over disposal of sewage, industrial wastes, stormwater, or other wastes, including special districts under state law such as a sewer district, flood control district or drainage district, or similar entity, or an Indian tribe or an authorized Indian tribal organization, or a designated and approved management agency under section 208 of the Clean Water Act (CWA) that discharges to waters of the United States;
  • Designed or used for collecting or conveying stormwater;
  • Which is not a combined sewer; and
  • Which is not part of a publicly owned treatment works (POTW).
    [40 CFR 122.26(b)(8)].

National Pollutant Discharge Elimination System (NPDES)

A national program under Section 402 of the Clean Water Act for regulation of discharges of pollutants from point sources to waters of the United States. Discharges are illegal unless authorized by an NPDES permit.


Dredged spoil, solid waste, incinerator residue, filter backwash, sewage, garbage, sewage sludge, munitions, chemical wastes, biological materials, radioactive materials (except those regulated under the Atomic Energy Act of 1954, as amended (42 U.S.C. 2011 et seq.)), heat, wrecked or discarded equipment, rock, sand, cellar dirt, and industrial, municipal, and agricultural waste discharged into water [40 CFR 122.2].

Pollutant, Conservative

Pollutants that do not readily degrade in the environment, and which are mitigated primarily by natural stream dilution after entering receiving bodies of waters. Included are pollutants such as metals.

Pollutant, Non-Conservative

Pollutants that are mitigated by natural biodegradation or other environmental decay or removal processes in the receiving stream after in-stream mixing and dilution have occurred.


Stormwater runoff, snow melt runoff, and surface runoff and drainage [40 CFR 122.26(b)(13)].

Stormwater Discharge-Related Activities

Activities that cause, contribute to, or result in stormwater point source pollutant discharges, including excavation, site development, grading, and other surface disturbance activities; and measures to control stormwater, including the siting, construction, and operation of BMPs to control, reduce, or prevent stormwater pollution.

Toxic Pollutant

Pollutants or combinations of pollutants, including disease-causing agents, which after discharge and upon exposure, ingestion, inhalation or assimilation into any organism, either directly from the environment or indirectly by ingestion through food chains, will, on the basis of information available to the Administrator of EPA, cause death, disease, behavioral abnormalities, cancer, genetic mutations, physiological malfunctions, (including malfunctions in reproduction) or physical deformations, in such organisms or their offspring. Toxic pollutants also include those pollutants listed by the Administrator under CWA Section 307(a)(1) or any pollutant listed under Section 405(d) which relates to sludge management.


Areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas.

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Last updated: 8/30/2016 10:20:23 AM

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