| BMP | Best Management Practices - practices that are used to reduce pollutants typically present in stormwater runoff, prior to the runoff entering streams and rivers. |
| CCR | Certified Construction Reviewer |
| DNREC | Delaware Department of Natural resources and Environmental Control |
| Dry Weather Condition | The period following at least 72-hours after the most recent precipitation event measuring at least 0.10 inches or more. |
| EPA | Environmental Protection Agency |
| Filtration Devices | Devices that remove particulates and associated pollutants such as heavy metals and phosphorous. (see BMPs) |
| Flow Control Devices | Devices that control the flow of runoff including detention/retention ponds, constructed wetlands, dams and check dams and rain barrels. (see BMPs) |
| Groundwater | Groundwater is the water beneath the surface that can be collected with wells, tunnels, or drainage galleries, or that flows naturally to the earth's surface via seeps or springs. Groundwater is the water that is pumped by wells and flows out through springs. |
| Hydrodynamic Devices | Special structures that concentrate and remove sediment, litter and other floatable solids, and oil. (see BMPs) |
| Infiltration Devices | Devices that allow stormwater to return to the ground, rather than simply run off impervious surfaces. (see BMPs) |
| Inlet | Where the water enters the storm sewer/drainage system. |
| MS4 | Municipal Separate Storm Sewer System |
| National Pollutant Discharge Elimination System (NPDES) | A permit program that controls water pollution by regulating point sources that discharge pollutants into waters of the United States. |
| NOI | Notice of Intent |
| Outlet or Outfall | Where the stormwater exits the storm sewer/drainage system. |
| Point Sources | The outfalls from conveyances such as pipes or man-made ditches |
| Recharge | A recharge area is an area that allows water to enter the aquifer. The area is particularly vulnerable to any pollutants that could be in the water. If pavement is constructed over this area, less water can enter the aquifer. This could mean a water shortage to those people using the groundwater from the aquifer. |
| Riparian Buffer | Riparian buffers are transition areas between water and land. They link terrestrial upland ecosystems to stream, river, lake, or wetland ecosystems. Buffers can be strips of grassy land leading to the water's edge or thickly forested streamside areas. Their functions include: protecting and improving water quality, improving wildlife habitat and biodiversity, and protecting against erosion and preserving stream characteristics, and providing recreational and aesthetic value. |
| Runoff | Precipitation that hits the ground and starts to flow over land. |
| Sediment | Soils or other surficial materials transported and/or deposited by the action of wind, water, ice or gravity as a product of erosion. |
| S & S | Sediment and Stormwater |
| Stormwater Drainage System | A route of drainage for precipitation (rain or snow) |
| Waterbody | A body of water including ponds, lakes, stream, rivers, etc. |
| Wetland | A lowland area, such as a marsh or swamp, that is saturated with moisture, especially when regarded as the natural habitat of wildlife |
| Wet Weather Sampling | The collection of stormwater samples following a dry weather condition, commencing within 20 minutes of the start of precipitation and continuing with continued precipitation for 3.0 hours. |