Definitions

Note: all definitions taken directly from the CASQA BMP Handbooks
  • 303(d) Listed: Water bodies listed as impaired as per Section 303(d) of the 1972 Clean Water Act.
  • Best Management Practices (BMPs): Includes schedules of activities, prohibitions of practices, maintenance procedures, and other management practices to prevent, eliminate, or reduce the pollution of waters of the receiving waters. BMPs also include treatment requirements, operating procedures, and practices to control plant site runoff spillage or leaks, sludge or waste disposal, or drainage from raw material storage.
  • Catch Basin (Also known as Inlet): Box-like underground concrete structure with openings in curbs and gutters designed to collect runoff from streets and pavement.
  • Clean Water Act (CWA): (33 U.S.C. 1251 et seq.) requirements of the NPDES program are defined under Sections 307, 402, 318 and 405 of the CWA.
  • Construction Activity: Includes clearing, grading, excavation, and contractor activities that result in soil disturbance.
  • Construction General Permit: A National Pollutant Discharge Elimination System (NPDES) permit issued by the State Water Resources Control Board for the discharge of stormwater associated with construction activity from soil disturbance of five acres or more. Threshold lowered to 1 acre beginning October 10, 2003. Construction General Permit No.CAS000002.
  • Denuded: Land stripped of vegetation or land that has had its vegetation worn down due to the impacts from the elements or humans.
  • Detention: The capture and subsequent release of stormwater runoff from the site at a slower rate than it is collected, the difference being held in temporary storage.
  • Discharge: A release or flow of stormwater or other substance from a conveyance system or storage container. Broader - includes release to storm drains, etc.
  • Effluent Limits: Limitations on amounts of pollutants that may be contained in a discharge. Can be expressed in a number of ways including as a concentration, as a concentration over a time period (e.g., 30-day average must be less than 20 mg/l), or as a total mass per time unit, or as a narrative limit.
  • Erosion: The wearing away of land surface by wind or water. Erosion occurs naturally from weather or runoff but can be intensified by land-clearing practices related to farming, new development, redevelopment, road building, or timber cutting.
  • Facility: Is a collection of industrial processes discharging stormwater associated with industrial activity within the property boundary or operational unit.
  • Grading: The cutting or filling of the land surface to a desired slope or elevation.
  • Hazardous Waste: A waste or combination of wastes that, because of its quantity, concentration, or physical, chemical or infectious characteristics, may either cause or significantly contribute to an increase in mortality or an increase in serious irreversible illness - or pose a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported, disposed of or otherwise managed. Possesses at least 1 of 4 characteristics (ignitability, corrosivity, reactivity, or toxicity) or appears on special EPA or state lists. Regulated under the federal Resource Conservation and Recovery Act and the California Health and Safety Code.
  • Illicit Discharges: Any discharge to a municipal separate storm sewer that is not in compliance with applicable laws and regulations as discussed in this document.
  • Industrial General Permit: A National Pollutant Discharge Elimination System (NPDES) Permit (No. CAS000001) issued by the State Water Resources Control Board for discharge of stormwater associated with industrial activity. Board Order 97-03-DWQ.
  • Inlet: An entrance into a ditch, storm drain, or other waterway.
  • Integrated Pest Management (IPM): An ecosystem-based strategy that focuses on long term prevention of pests or their damage through a combination of techniques such as biological control, habitat manipulation, modification of cultural practices, and use of resistant varieties. Pesticides are used only after monitoring indicates they are needed according to established guidelines, and treatments are made with the goal of removing only the target organism.
  • 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), designed or used for collecting or conveying storm water:
    • Which is not a combined sewer
    • Which is not part of a Publicly Owned Treatment Works (POTW) as defined at Title 40 of the Code of Federal Regulations (CFR) 122.2.
    • A “Small MS4” is defined as an MS4 that is not a permitted MS4 under the Phase I regulations. This definition of a Small MS4 applies to MS4 operated within cities and counties as well as governmental facilities that have a system of storm sewers.
  • Non-Stormwater Discharge: Any discharge to municipal separate storm sewer that is not composed entirely of stormwater.
  • Nonpoint Source Pollution: Pollution that does not come from a point source. Nonpoint source pollution originates from aerial diffuse sources that are mostly related to land use.
  • Notice of Intent (NOI): A formal notice to SWRCB submitted by the owner of an industrial site or construction site that said owner seeks coverage under a General Permit for discharges associated with industrial and construction activities. The NOI provides information on the owner, location, type of project, and certifies that the owner will comply with the conditions of the construction General Permit.
  • Notice of Termination (NOT): Formal notice to SWRCB submitted by owner/ developer that a construction project is complete.
  • NPDES Permit: NPDES is an acronym for National Pollutant Discharge Elimination System. NPDES is the national program for administering and regulating Sections 307, 318, 402, and 405 of the Clean Water Act (CWA). In California, the State Water Resources Control Board (SWRCB) has issued a General Permit for stormwater discharges associated with industrial activities (see Appendix A).
  • Outfall: The end point where storm drains discharge water into a waterway.
  • Point Source: Any discernible, confined, and discrete conveyance from which pollutants are or may be discharged. This term does not include return flows from irrigated agriculture or agricultural stormwater runoff.
  • Pollutant: Generally, any substance introduced into the environment that adversely affects the usefulness of a resource.
  • Pollution Prevention (P2): Practices and actions that reduce or eliminate the generation of pollutants.
  • Precipitation: Any form of rain or snow.
  • Pretreatment: Treatment of waste stream before it is discharged to a collection system.
  • Reclaim (water reclamation): Planned use of treated effluent that would otherwise be discharged without being put to direct use.
  • Retention: The storage of stormwater to prevent it from leaving the development site.
  • Reuse (water reuse): (see Reclaim)
  • Runoff: Water originating from rainfall, melted snow, and other sources (e.g., sprinkler irrigation) that flows over the land surface to drainage facilities, rivers, streams, springs, seeps, ponds, lakes, and wetlands.
  • Run-on: Off site stormwater surface flow or other surface flow which enters your site.
  • Scour: The erosive and digging action in a watercourse caused by flowing water.
  • Secondary Containment: Structures, usually dikes or berms, surrounding tanks or other storage containers, designed to catch spilled materials from the storage containers.
  • Sedimentation: The process of depositing soil particles, clays, sands, or other sediments that were picked up by runoff.
  • Sediments: Soil, sand, and minerals washed from land into water, usually after rain, that collect in reservoirs, rivers, and harbors, destroying fish nesting areas and clouding the water, thus preventing sunlight from reaching aquatic plants. Farming, mining, and building activities without proper implementation of BMPs will expose sediment materials, allowing them to be washed off the land after rainfalls.
  • Significant Materials: Materials with the potential to be released with stormwater discharges, including but not limited to:
    • Any chemical the facility is required to report pursuant to Section 313 of Title III of SARA
    • Fertilizers
    • Finished materials such as metallic products
    • Fuels
    • Hazardous substances designed under Section 101(14) of CERLCA
    • Materials such as solvents, detergents, and plastic pellets
    • Pesticides
    • Raw materials
    • Raw materials used in food processing or production
    • Waste products such as ashes, slag, and sludge that have the potential to be released with stormwater discharges.
  • Significant Quantities: The volume, concentrations, or mass of a pollutant in stormwater discharge that can cause or threaten to cause pollution, contamination, or nuisance that adversely impact human health or the environment and cause or contribute to a violation of any applicable water quality standards for receiving water.
  • Source Control BMPs: Operational practices that reduce potential pollutants at the source.
  • Source Reduction (also source control): The technique of stopping and/ or reducing pollutants at their point of generation so that they do not come into contact with stormwater.
  • Storm Drains: Above- and below-ground structures for transporting stormwater to streams or outfalls for flood control purposes.
  • Stormwater: Defined as urban runoff and snowmelt runoff consisting only of those discharges, which originate from precipitation events. Stormwater is that portion of precipitation that flows across a surface to the storm drain system or receiving waters.
  • Stormwater Discharge Associated with Industrial Activity: Discharge from any conveyance which is used for collecting and conveying stormwater from an area that is directly related to manufacturing, processing, or raw materials storage activities at an industrial plant.
  • Stormwater Pollution Control Plan (SWPCP): A less formal plan than the SWPPP that addresses the implementation of BMPs at facilities / businesses not covered by a general permit but that have the potential to discharge pollutants.
  • Stormwater Pollution Prevention Plan (SWPPP): A written plan that documents the series of phases and activities that, first, characterizes your site, and then prompts you to select and carry out actions which prevent the pollution of stormwater discharges.
  • Treatment Control BMPs: Treatment methods to remove pollutants from stormwater.
  • Toxicity: Adverse responses of organisms to chemicals or physical agents ranging from mortality to physiological responses such as impaired reproduction or growth anomalies.