Page 1 of 74
NEW CPESC PRACTICE EXAM QUESTIONS
AND ANSWERS TESTED AND APPROVED
GRADED A+
What would have to be updated as construction progressed on the SWPPP? --
ANSWER--Installation and removal dates, changes in plan designs, and
changes in BMPs
When are outlet protectors used? Examples? -- ANSWER--To control runoff;
wattles, check dams (energy dissipaters) or thick/matted veg, riprap (ground
cover)
What is the RUSLE equation? -- ANSWER--A = R K L S C P
What are the units for A in RUSLE? -- ANSWER--Ton/ha/year
What kind of erosion does RUSLE cover? -- ANSWER--Sheet and rill erosion
only
What influences soil erodibility? -- ANSWER--Soil texture, structure and % of
OM
1
, Page 2 of 74
How does vegetative cover influence erodibility? -- ANSWER--Top growth
reduces raindrop impact, filters sediment and slows down runoff velocity; roots
hold mass particles together
How can you decrease erodibility in relation to topography? -- ANSWER-
Increase slope roughness
What climate characteristics affect erodibility? -- ANSWER--Rainfall intensity,
duration and frequency
BMP considerations for clearing and grubbing? -- ANSWER--Preserve existing
vegetation; clear only what is required for immediate construction activity
BMP considerations for mass grading? -- ANSWER--Create principle basins,
traps, barriers, diversions and channels; temporary stabilization; manage
concentrated runon and runoff (water bars)
BMP considerations for site access & off-hauling? -- ANSWER--Stabilize with
gravel and temporary vegetation; limit ingress and egress points
2
, Page 3 of 74
What are the 3 stages of inlet construction? -- ANSWER--Pipe installation, inlet
construction, inlet backfill
BMP considerations of channel construction? -- ANSWER--Monitor weather,
install grade controls, stabilize streambanks early; consider time of year
(weather) to start construction (phasing)
BMP considerations of final stabilization? -- ANSWER--Immediately apply
temp or permanent stabilization of disturbed areas; don't allow surface area to
dry out for a few days before seeding (affects germination)
BMP considerations of vertical construction? -- ANSWER--Protect inlets;
modify plan to show new conditions and updated measures
Why does frequent rainfall increase erodibility? -- ANSWER--The soil becomes
saturated and no more water can infiltrate which increases runoff volume
Why is erosion potential high in the spring if it rains? -- ANSWER--Water can't
infiltrate the frozen subsoil which increases runoff volume
What are some ways urban development impacts erosion hazards? --
3
, Page 4 of 74
ANSWER--Changes hydrology (GW flow, drainage), disturbs large amounts of
soil, removes plant cover
What are the 5 factors that influence erosion? -- ANSWER--Soil erodibility,
topography, vegetative cover, season, climate (rainfall)
Define soil erodibility -- ANSWER--The ease with which soil is detached by
splash during rainfall
Why is sediment yield different from erosion rate? -- ANSWER--Sediment yield
is the amount of eroded soil that is delivered to a certain point whereas erosion
rate is the rate of soil wearing away from an area
What is the formula for MUSLE? -- ANSWER--T=11.8(V.Qp)^0.56 K LS C P
What is V and Qp in MUSLE? -- ANSWER--V = volume of storm runoff in
mm3
Qp = Peak flow for storm in m3/s
4
NEW CPESC PRACTICE EXAM QUESTIONS
AND ANSWERS TESTED AND APPROVED
GRADED A+
What would have to be updated as construction progressed on the SWPPP? --
ANSWER--Installation and removal dates, changes in plan designs, and
changes in BMPs
When are outlet protectors used? Examples? -- ANSWER--To control runoff;
wattles, check dams (energy dissipaters) or thick/matted veg, riprap (ground
cover)
What is the RUSLE equation? -- ANSWER--A = R K L S C P
What are the units for A in RUSLE? -- ANSWER--Ton/ha/year
What kind of erosion does RUSLE cover? -- ANSWER--Sheet and rill erosion
only
What influences soil erodibility? -- ANSWER--Soil texture, structure and % of
OM
1
, Page 2 of 74
How does vegetative cover influence erodibility? -- ANSWER--Top growth
reduces raindrop impact, filters sediment and slows down runoff velocity; roots
hold mass particles together
How can you decrease erodibility in relation to topography? -- ANSWER-
Increase slope roughness
What climate characteristics affect erodibility? -- ANSWER--Rainfall intensity,
duration and frequency
BMP considerations for clearing and grubbing? -- ANSWER--Preserve existing
vegetation; clear only what is required for immediate construction activity
BMP considerations for mass grading? -- ANSWER--Create principle basins,
traps, barriers, diversions and channels; temporary stabilization; manage
concentrated runon and runoff (water bars)
BMP considerations for site access & off-hauling? -- ANSWER--Stabilize with
gravel and temporary vegetation; limit ingress and egress points
2
, Page 3 of 74
What are the 3 stages of inlet construction? -- ANSWER--Pipe installation, inlet
construction, inlet backfill
BMP considerations of channel construction? -- ANSWER--Monitor weather,
install grade controls, stabilize streambanks early; consider time of year
(weather) to start construction (phasing)
BMP considerations of final stabilization? -- ANSWER--Immediately apply
temp or permanent stabilization of disturbed areas; don't allow surface area to
dry out for a few days before seeding (affects germination)
BMP considerations of vertical construction? -- ANSWER--Protect inlets;
modify plan to show new conditions and updated measures
Why does frequent rainfall increase erodibility? -- ANSWER--The soil becomes
saturated and no more water can infiltrate which increases runoff volume
Why is erosion potential high in the spring if it rains? -- ANSWER--Water can't
infiltrate the frozen subsoil which increases runoff volume
What are some ways urban development impacts erosion hazards? --
3
, Page 4 of 74
ANSWER--Changes hydrology (GW flow, drainage), disturbs large amounts of
soil, removes plant cover
What are the 5 factors that influence erosion? -- ANSWER--Soil erodibility,
topography, vegetative cover, season, climate (rainfall)
Define soil erodibility -- ANSWER--The ease with which soil is detached by
splash during rainfall
Why is sediment yield different from erosion rate? -- ANSWER--Sediment yield
is the amount of eroded soil that is delivered to a certain point whereas erosion
rate is the rate of soil wearing away from an area
What is the formula for MUSLE? -- ANSWER--T=11.8(V.Qp)^0.56 K LS C P
What is V and Qp in MUSLE? -- ANSWER--V = volume of storm runoff in
mm3
Qp = Peak flow for storm in m3/s
4
