CPESC flashcards
CPESC · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- USLE equation
- A = R × K × LS × C × P estimates average annual soil loss from sheet and rill erosion; each factor represents rainfall, soil, slope, cover, and support practice effects.
- Raindrop impact erosion
- Raindrop impact detaches soil particles and seals surface pores; protecting the surface with mulch, blankets, or vegetation reduces both detachment and runoff.
- LS factor
- The LS factor combines slope length and steepness in USLE/RUSLE; longer or steeper slopes increase erosion because runoff gains velocity and transport capacity.
- Critical shear stress
- Critical shear stress is the boundary stress at which soil or a lining begins to erode; comparing it with applied shear γRS determines stability.
- Silt fence limitation
- Silt fence treats sheet flow along a perimeter and fails when used to convey concentrated flow; it must be keyed, on contour, and maintained.
- Sediment basin settling
- Sediment basins remove particles by gravity settling; surface area, residence time, and a slow-release outlet control trap efficiency.
- Check dam spacing
- Check dams reduce channel velocity and grade; they are spaced so the downstream dam crest is near the toe of the upstream dam.
- Polyacrylamide flocculant
- Anionic polyacrylamide binds suspended clay into larger flocs that settle faster; dosing must match site soil and water chemistry.
- Rational method
- Q = CiA estimates peak runoff for small catchments, where C is runoff coefficient, i is design intensity, and A is drainage area.
- Manning equation
- V = (1.486/n)R^(2/3)S^(1/2) in English units predicts open-channel velocity from roughness, hydraulic radius, and energy slope.
- Froude number
- Fr = V/√(gD) classifies open-channel flow as subcritical below 1, critical at 1, and supercritical above 1; supercritical flow can form hydraulic jumps.
- Curve number runoff
- NRCS curve number method estimates runoff depth from rainfall and a curve number representing soil, land use, and antecedent moisture.
- Soil texture triangle
- The USDA texture triangle classifies soil by percentages of sand, silt, and clay; texture controls infiltration, erodibility, and water holding capacity.
- Cation exchange capacity
- CEC is the soil's capacity to hold exchangeable cations; it is high in clay and organic matter and affects nutrient and contaminant retention.
- Sodic soil dispersion
- High sodium relative to calcium causes clay dispersion, surface sealing, and low infiltration; gypsum can supply calcium to improve structure.
- Hydrologic soil group
- Hydrologic soil groups A through D rate soils from high to low infiltration; group D soils generate the most runoff for a given storm.
- NPDES Section 402
- Clean Water Act Section 402 authorizes NPDES permits controlling stormwater discharges from construction sites and other point sources.
- Section 404 permit
- Clean Water Act Section 404 regulates discharge of dredged or fill material into waters of the United States, including wetlands.
- Notice of Intent
- A NOI is submitted to obtain construction stormwater permit coverage before discharging; it identifies the operator, site, and SWPPP.
- Notice of Termination
- A NOT ends NPDES construction stormwater coverage after final stabilization and removal of temporary controls, as allowed by the permit.
- SWPPP purpose
- A SWPPP identifies construction pollutant sources and specifies BMPs, inspections, maintenance, and recordkeeping to prevent stormwater pollution.
- Pollution prevention hierarchy
- Prevent exposure first, then control runoff, then trap sediment, and finally treat discharge; source controls are preferred over end-of-pipe treatment.
- Concrete washout
- Concrete washout must be a lined, contained area away from storm drains; washwater is highly alkaline and cannot be discharged to stormwater.
- Final stabilization
- Final stabilization means permanent uniform cover, such as established vegetation or equivalent, that will prevent erosion after construction ends.
- Silt fence installation
- Install silt fence on contour with a compacted keyed trench and posts on the downhill side so runoff ponds and deposits sediment.
- Blanket anchoring
- Erosion control blankets need a terminal anchor trench, specified overlaps, and staples that hold fabric tightly against soil.
- Basin cleanout
- Remove accumulated sediment from a basin when it reaches the cleanout mark or about half the design storage volume.
- Inspection documentation
- Record date, time, weather, inspector, BMP conditions, deficiencies, corrective actions, and photographs to create a defensible inspection trail.
- Contemporaneous records
- Field records should be made at the time of observation, with factual entries, dates, signatures, and corrections that preserve the original data.
- Conflict of interest
- A conflict exists when personal, financial, or other interests could impair professional judgment; it must be disclosed and managed.
- Chain of custody
- A chain-of-custody form tracks sample possession from collection through analysis, supporting defensibility of monitoring results.
- Falsification prohibition
- Never fabricate, alter, or backdate environmental data; false records violate professional ethics and permit requirements and can lead to enforcement.