CEPSCI Water Quality Monitoring and Testing 1

Question 1

Which water quality parameter is most commonly used to assess the effectiveness of sediment controls at a construction site discharge point?

Accepted Answer

Turbidity

Answer

Turbidity measures the cloudiness of water caused by suspended sediment particles, making it the primary indicator of sediment control effectiveness at construction discharges.

Question 2

What unit of measurement is most commonly used to express turbidity in stormwater monitoring?

Accepted Answer

NTU

Answer

Nephelometric Turbidity Units (NTU) is the standard unit used to measure turbidity in water quality monitoring programs.

Question 3

Under the EPA's Construction General Permit (CGP), operators must conduct water quality monitoring when a project discharges to a water body that is impaired for which of the following?

Accepted Answer

Sediment or turbidity

Answer

The CGP requires enhanced monitoring when construction sites discharge to 303(d)-listed impaired water bodies for sediment or turbidity.

Question 4

A grab sample collected for turbidity monitoring at a construction site should ideally be taken:

Accepted Answer

During a storm event when discharge is actively occurring

Answer

Grab samples for turbidity should be collected during active storm discharge to capture representative water quality conditions at the point of discharge.

Question 5

What is the typical acceptable turbidity benchmark for construction site discharges under many state NPDES permits before further action is required?

Accepted Answer

250 NTU

Answer

Many state NPDES permits and the EPA CGP use a benchmark of 250 NTU as a threshold that triggers corrective action requirements.

CEPSCI - Certified Erosion Prevention and Sediment Control Inspector Practice Test

CEPSCI - Certified Erosion Prevention and Sediment Control Inspector Practice Test

CEPSCI Water Quality Monitoring and Testing 1