Erosion and Sediment Pollution Control Program Manual.pdf

Bedrock----- The more or less solid rock in place either on the surface or under the soil layers. It may
be soft, medium or hard and have a smooth or irregular surface.
Bench -----A constructed break in a cut slope or fill slope for the purpose of conveying runoff to one or
both sides.
Bench Mark -----Point of known elevation for a survey. It may be in relation to National Geodetic
Vertical Datum (NGVD) or assumed for a given project.
Benthic Zone -----The bottom zone of a lake, where oxygen levels are low.
Bentonite -----A volcanic clay material that exhibits extremely large volume changes with moisture
content changes, filling gaps and sealing itself against adjacent materials. It is commonly used
to seal abandoned wells or leaking spillways in sediment basins and traps.
Berm -----1. A compacted mound or wall of earth used to direct runoff (e.g. dike) or impound it
(e.g. embankment of a sediment basin or trap). 2. A nearly horizontal part of a beach or
backshore formed at the high water line by waves depositing material. Some beaches have no
berms, others have one or several.
Best Management Practice (BMP) ----- Activities, facilities, measures, planning or procedures used to
minimize accelerated erosion and sedimentation and manage stormwater to protect, maintain,
reclaim, and restore the quality of waters and the existing and designated uses of waters within
this Commonwealth before, during, and after earth disturbance activities.
Beveled End -----A type of endwall with a cut that is inclined to the horizontal.
Biennial Plant -----A plant that requires 2 years to complete its life cycle.
Bifurcation Ratio -----The average number of streams feeding into the next order waterway. The
usual range is 2 to 4.
Binder -----1. A natural or synthetic additive that causes an otherwise non-cohesive material to become
bound into a cohesive matrix; 2. emulsion or tackifier.
Biochemical Oxygen Demand (BOD) -----The quantity of oxygen needed by microorganisms in a
body of water to decompose the organic matter present. An index of water pollution.
Biodegradable -----Able to decompose when exposed to biological agents and/or soil chemicals.
Bioengineering -----1. Use of woody vegetative growth to stabilize stream banks and other slopes.
2. Combination of vegetative and structural practices to stabilize stream banks and/or slopes.
Biofiltration -----The simultaneous process of filtration, infiltration, adsorption, and biological uptake of
pollutants in stormwater that takes place when runoff flows over and through vegetated areas.
Blanket -----Material placed on exposed soil to hold it in place until a vegetative cover can be
established.
Bloom -----A phenomenon whereby excessive nutrients within a body of water results in an explosion
of plant life, resulting in a depletion of oxygen and fish kill, usually caused by runoff containing
fertilizers.
Bluff -----A high, steep bank or cliff.
BMPs -----Best management practices
BMP Fingerprinting -----A series of techniques for locating BMPs, especially basins, within a
development site so as to minimize their impacts to wetlands, forest, and sensitive stream
reaches.
BMP Sequence -----See Construction Sequence
Body of Water -----Any natural or artificial lake, pond, reservoir, swamp, marsh or wetland.
Bog -----A type of wetland characterized by spongy, acidic peat deposits; a growth of evergreen trees
and shrubs; and a carpet of sphagnum moss. Their only water source is rainwater and nutrient
levels are very low. They often form in old glacial lakes.
Boil -----An upward disturbance in the surface layer of soil caused by water escaping under pressure
from behind or under a water-retaining structure such as a dam or levee. The boil may be
accompanied by deposition of soil particles, usually silt, in the form of a ring around the area
where the water escapes.
Borehole Log -----A physical description of the various soil and/or rock types encountered while drilling
a hole and the relative depths at which changes in soil or rock types occurred. If water is
encountered during the drilling, the elevation(s) where this occurred are also noted.
Boring -----A hole advanced into the ground by means of a drilling rig.
Boring, Test -----Soil analysis taken by boring holes into the ground to remove samples.
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