CPESC FINAL PAPER 2025/2026 QUESTIONS WITH
ANSWERS GRADED A+
✔✔first regulations of stormwater - ✔✔Nov 16, 1990, stormwater application rule
April 1992, stormwater implementation rule
✔✔what are NPDES exempt - ✔✔agricultural return flows and runoff from silviculture
oil and gas operations
✔✔NPDES Phase 1 - ✔✔5 acres of more
disturbance includes clearing, grading and excavation
smaller parcels part of larger plan that affects at least 5 acres
✔✔Waste Load Allocations (WLA) - ✔✔once TMDL determined, regulatory agency
allocates a portion to each source of that pollutant within a particular watershed
✔✔Administrative Order - ✔✔EPA can impose fines and penalties without court action
Maximum is 11,000 per day with a maximum of 32,500 for CLass 1 offenses, 16,000
per day and max of 177,000 for class II offenses...
✔✔Hazards associated with urban developments - ✔✔soil exposed to erosion from
wind and water
increased water runoff, soil movement and sediment accumulation from: removal of
plant cover, construction of impervious areas, changes in drainage areas caused by
grading, changes in volume and duration of flows caused by altering steepness,
distance and surface roughness, soil compaction by heavy equipment, ...
✔✔Factors that influence erosion - ✔✔Soil erodibility
Vegetative Cover
Topography
Climate
Season
✔✔Soil Erodibility - ✔✔vulnerability of a soil to different erosion processes. Soil
structure, texture and percentage of organic matter influence erodibility.
The presence of clay or organic matter tends to decrease soil erodibility. Clays are
cohesive and tend to bind soil particles together, organic matter helps to maintain stable
soil structure
✔✔Vegetative Cover - ✔✔top growth shields the surface from raindrop impact while the
root mass holds soil particles in place. Filter strips filter sediment from runoff, grasses
slow velocity and maintain infiltration
,✔✔What are the most important factors in minimizing erosion during development -
✔✔Establishment and maintenance of vegetation
✔✔Topography - ✔✔Slope length and steepness influence volume and velocity of
surface runoff. Long slopes deliver more runoff to the base of the slopes and steep
slopes increase runoff velocity. Both enhance potential for erosion
✔✔Climate - ✔✔As frequency of rainfall increases, water has less chance to drain
through the soils. Soil remains saturated and runoff volume may increase.
✔✔Season - ✔✔seasonal variation in temperature and rainfall defines periods of high
erosion potential during the year
✔✔Recommenced Erosion and sediment control scales - ✔✔1 in = 20 ft
1 in = 30 ft
1 in = 40 ft
1 in = 50 ft
contour intervals should be 2 feet or less
✔✔Steps in Construction Sequencing - ✔✔Pre Construction : mark sensitive areas
Construction Access: construction entrances, etc
Sediment Barriers and Traps: install basin after site assessed
Runoff control: diversions, outlet protection
Runoff Conveyance
Land Clearing and Grading
Surface Stabilization
Building Construction
Landscaping and Final Stabilizaiton
✔✔4 steps in planning process - ✔✔Design SWPP to match project
Determine limits of clearing
Divide site into natural drainage areas
Design erosion and sediment control practices
✔✔Major variables that affect soil erosion by water - ✔✔susceptibility of soil to erosion
potential erosivity of rainfall and runoff
soil protection by plant cover
✔✔S - ✔✔Slope steepness factor
ratio of soil loss from the field slop gradient to soil loss from a 9% slope under otherwise
identical conditions
✔✔L - ✔✔Slope length factor
, ration of soil loss from the field slope length to soil loss from a 72.6 ft length under
identical conditions
✔✔K - ✔✔soil erodibility factor
the soil - loss rate per erosion index unit for a specific soil
✔✔P - ✔✔Erosion Control Practice Factor
ratio of soil loss with certain conservation practice to that of no practice
✔✔C - ✔✔Cover management factor
ratio of soil loss from an area with specified cover and management to soil loss from an
identical area in a bare condition
✔✔USLE
Universal Soil Loss Equation - ✔✔quantifies six factors: rainfall and runoff erosiveness,
soil erodibility, slope length, slope steepness, cover management practices and support
conservation practices
✔✔What is the major soil conversation planning tool - ✔✔USLE
✔✔Sediment yield - ✔✔the amount of eroded soil that is delivered to a point in the
watershed that is remote from the original of the detached soil particles
✔✔RUSLE - ✔✔A = R x K x LS x C x P
erosion model designed to predict the longtime average annual soil loss (A) carried by
runoff from specific slope s in specified management conditions
✔✔A - ✔✔computed spacial average soil loss and temporal average soil loss per unit of
acres expressed in the units selected for K and for the period selected for R.
Typically selected in tons per acre per year
✔✔R - ✔✔Rainfall-runoff erosivity factor
Rainfall erosion index plus a factor for any significant runoff from snowmelt
✔✔What does RUSLE not apply to? - ✔✔Don't use RUSLE for disturbed forested
conditions
✔✔RUSLE - ✔✔users need to be aware that A (in addition to being longtime average
annual soil loss) is the AVERAGE loss over a slope and that the losses at various parts
of the slope may differ greatly from one another.
ANSWERS GRADED A+
✔✔first regulations of stormwater - ✔✔Nov 16, 1990, stormwater application rule
April 1992, stormwater implementation rule
✔✔what are NPDES exempt - ✔✔agricultural return flows and runoff from silviculture
oil and gas operations
✔✔NPDES Phase 1 - ✔✔5 acres of more
disturbance includes clearing, grading and excavation
smaller parcels part of larger plan that affects at least 5 acres
✔✔Waste Load Allocations (WLA) - ✔✔once TMDL determined, regulatory agency
allocates a portion to each source of that pollutant within a particular watershed
✔✔Administrative Order - ✔✔EPA can impose fines and penalties without court action
Maximum is 11,000 per day with a maximum of 32,500 for CLass 1 offenses, 16,000
per day and max of 177,000 for class II offenses...
✔✔Hazards associated with urban developments - ✔✔soil exposed to erosion from
wind and water
increased water runoff, soil movement and sediment accumulation from: removal of
plant cover, construction of impervious areas, changes in drainage areas caused by
grading, changes in volume and duration of flows caused by altering steepness,
distance and surface roughness, soil compaction by heavy equipment, ...
✔✔Factors that influence erosion - ✔✔Soil erodibility
Vegetative Cover
Topography
Climate
Season
✔✔Soil Erodibility - ✔✔vulnerability of a soil to different erosion processes. Soil
structure, texture and percentage of organic matter influence erodibility.
The presence of clay or organic matter tends to decrease soil erodibility. Clays are
cohesive and tend to bind soil particles together, organic matter helps to maintain stable
soil structure
✔✔Vegetative Cover - ✔✔top growth shields the surface from raindrop impact while the
root mass holds soil particles in place. Filter strips filter sediment from runoff, grasses
slow velocity and maintain infiltration
,✔✔What are the most important factors in minimizing erosion during development -
✔✔Establishment and maintenance of vegetation
✔✔Topography - ✔✔Slope length and steepness influence volume and velocity of
surface runoff. Long slopes deliver more runoff to the base of the slopes and steep
slopes increase runoff velocity. Both enhance potential for erosion
✔✔Climate - ✔✔As frequency of rainfall increases, water has less chance to drain
through the soils. Soil remains saturated and runoff volume may increase.
✔✔Season - ✔✔seasonal variation in temperature and rainfall defines periods of high
erosion potential during the year
✔✔Recommenced Erosion and sediment control scales - ✔✔1 in = 20 ft
1 in = 30 ft
1 in = 40 ft
1 in = 50 ft
contour intervals should be 2 feet or less
✔✔Steps in Construction Sequencing - ✔✔Pre Construction : mark sensitive areas
Construction Access: construction entrances, etc
Sediment Barriers and Traps: install basin after site assessed
Runoff control: diversions, outlet protection
Runoff Conveyance
Land Clearing and Grading
Surface Stabilization
Building Construction
Landscaping and Final Stabilizaiton
✔✔4 steps in planning process - ✔✔Design SWPP to match project
Determine limits of clearing
Divide site into natural drainage areas
Design erosion and sediment control practices
✔✔Major variables that affect soil erosion by water - ✔✔susceptibility of soil to erosion
potential erosivity of rainfall and runoff
soil protection by plant cover
✔✔S - ✔✔Slope steepness factor
ratio of soil loss from the field slop gradient to soil loss from a 9% slope under otherwise
identical conditions
✔✔L - ✔✔Slope length factor
, ration of soil loss from the field slope length to soil loss from a 72.6 ft length under
identical conditions
✔✔K - ✔✔soil erodibility factor
the soil - loss rate per erosion index unit for a specific soil
✔✔P - ✔✔Erosion Control Practice Factor
ratio of soil loss with certain conservation practice to that of no practice
✔✔C - ✔✔Cover management factor
ratio of soil loss from an area with specified cover and management to soil loss from an
identical area in a bare condition
✔✔USLE
Universal Soil Loss Equation - ✔✔quantifies six factors: rainfall and runoff erosiveness,
soil erodibility, slope length, slope steepness, cover management practices and support
conservation practices
✔✔What is the major soil conversation planning tool - ✔✔USLE
✔✔Sediment yield - ✔✔the amount of eroded soil that is delivered to a point in the
watershed that is remote from the original of the detached soil particles
✔✔RUSLE - ✔✔A = R x K x LS x C x P
erosion model designed to predict the longtime average annual soil loss (A) carried by
runoff from specific slope s in specified management conditions
✔✔A - ✔✔computed spacial average soil loss and temporal average soil loss per unit of
acres expressed in the units selected for K and for the period selected for R.
Typically selected in tons per acre per year
✔✔R - ✔✔Rainfall-runoff erosivity factor
Rainfall erosion index plus a factor for any significant runoff from snowmelt
✔✔What does RUSLE not apply to? - ✔✔Don't use RUSLE for disturbed forested
conditions
✔✔RUSLE - ✔✔users need to be aware that A (in addition to being longtime average
annual soil loss) is the AVERAGE loss over a slope and that the losses at various parts
of the slope may differ greatly from one another.
