FSESCI Chapter 5: Dewatering UPDATED
ACTUAL Exam Questions and CORRECT
Answers
Dewatering operations - CORRECT ANSWER -Practices that manage the discharge of
pollutants when water (other than stormwater) must be removed from the work location so that
construction may be carried out.
Key considerations for choosing a specific dewatering control method - CORRECT
ANSWER -Sediment particle size
Limitation for receiving water (turbidity, nutrients, pollutants)
Discharge rate
Area available for control technique
Comparison of dewatering technologies - CORRECT ANSWER -See PowerPoint
4 types of dewatering control technologies - CORRECT ANSWER -Sediment traps
Weir tanks
Filters
Chemical treatment
Typical pumping methods - CORRECT ANSWER -Rim Ditch (Sump)
, Sock System (Horizontal well)
Well point system (Vertical well)
Rim Ditch Systems - CORRECT ANSWER -Poorest water quality (high turbidity, NTUs)
Discharge does not meet WQ standards
Often results in compliance action by agencies
Initially cheapest for contractor
Most expensive to cleanup
Sock Systems - CORRECT ANSWER -Generally produces clean discharge water
Requires some sandy soils to function (does not work well in clay soils)
Placed along perimeter of project
Can be expensive to install
Well Point Systems - CORRECT ANSWER -Makes cleanest water
Needs some sandy soils to function
Usually placed along excavation in terrace fashion (can also be linear)
ACTUAL Exam Questions and CORRECT
Answers
Dewatering operations - CORRECT ANSWER -Practices that manage the discharge of
pollutants when water (other than stormwater) must be removed from the work location so that
construction may be carried out.
Key considerations for choosing a specific dewatering control method - CORRECT
ANSWER -Sediment particle size
Limitation for receiving water (turbidity, nutrients, pollutants)
Discharge rate
Area available for control technique
Comparison of dewatering technologies - CORRECT ANSWER -See PowerPoint
4 types of dewatering control technologies - CORRECT ANSWER -Sediment traps
Weir tanks
Filters
Chemical treatment
Typical pumping methods - CORRECT ANSWER -Rim Ditch (Sump)
, Sock System (Horizontal well)
Well point system (Vertical well)
Rim Ditch Systems - CORRECT ANSWER -Poorest water quality (high turbidity, NTUs)
Discharge does not meet WQ standards
Often results in compliance action by agencies
Initially cheapest for contractor
Most expensive to cleanup
Sock Systems - CORRECT ANSWER -Generally produces clean discharge water
Requires some sandy soils to function (does not work well in clay soils)
Placed along perimeter of project
Can be expensive to install
Well Point Systems - CORRECT ANSWER -Makes cleanest water
Needs some sandy soils to function
Usually placed along excavation in terrace fashion (can also be linear)
