Resource Center
Erosion Control & Stormwater Glossary
Plain-language definitions of the terms that show up in SWPPPs, NPDES permits, and BMP plan sheets across Central Florida construction sites.
- NOI (Notice of Intent)
- The application filed with FDEP to obtain coverage under the NPDES Construction Generic Permit (CGP) for a construction site disturbing one or more acres. Filing an NOI certifies that a SWPPP already exists for the site.
- NOT (Notice of Termination)
- The filing that closes out NPDES Construction Generic Permit coverage once a site no longer needs it — generally once the site has reached final stabilization.
- MS4 (Municipal Separate Storm Sewer System)
- A municipal stormwater conveyance system regulated under its own NPDES permit. Counties and municipalities often administer MS4 permit conditions on top of the state NPDES Construction Generic Permit.
- CGP (Construction Generic Permit)
- Florida's NPDES Construction Generic Permit, administered by FDEP, which covers stormwater discharges from construction sites disturbing one or more acres.
- NPDES (National Pollutant Discharge Elimination System)
- The federal permitting framework under the Clean Water Act that requires construction sites disturbing one or more acres to obtain permit coverage and implement a SWPPP with appropriate BMPs.
- SWPPP (Stormwater Pollution Prevention Plan)
- The working reference document for a construction site's erosion and sediment control plan — site description, planned BMPs, a site map, and inspection/maintenance procedures. Field BMPs are judged against what the SWPPP specifies, not a generic standard.
- BMP (Best Management Practice)
- A structural or procedural control used to prevent or reduce sediment and pollutant discharge from a construction site — silt fence, inlet protection, sediment basins, construction entrances, and similar measures.
- Turbidity
- A measure of water cloudiness caused by suspended particles like sediment. Elevated turbidity in a receiving water is often the visible sign of an upstream sediment control failure.
- Riprap
- Graded stone placed over a filter fabric layer to armor surfaces against erosion from concentrated water flow or wave action — commonly used at drainage outfalls, channel linings, and pond banks.
- Silt Fence
- A temporary perimeter sediment barrier made of geotextile fabric, trenched and staked along the down-slope contour of disturbed soil to filter sediment from sheet-flow runoff.
- Inlet Protection
- A device — such as a fabric drop-in barrier or gravel filter ring — installed at a storm drain inlet to prevent sediment-laden runoff from entering the storm drain system directly.
- Sediment Control
- BMPs that capture soil already eroded and in motion — sediment basins, traps, check dams, and silt fence — as distinct from erosion control, which addresses the soil surface itself.
- Erosion Control
- Methods that prevent soil from eroding in the first place — mulch, erosion control blankets, seeding, and sod — as distinct from sediment control, which captures soil that has already eroded.
- AHJ (Authority Having Jurisdiction)
- The regulatory body — county, municipal, state, or federal — responsible for reviewing and enforcing permitting requirements on a given site. Final compliance determinations always rest with the AHJ, not a contractor or reference tool.
Need BMP support on an active site?
Send us the site location, photos, plans, or SWPPP and we'll respond with scope and next steps — typically within one business day.
Need erosion control, silt fence, BMP maintenance, or post-rain inspection support? Call 407-502-6476 or request a BMP proposal from Local Environmental Services.