CPESC Water Quality Standards 3

Question 1

Under EPA's Construction General Permit (CGP), what is the typical turbidity benchmark value that triggers additional BMP evaluation?

Accepted Answer

100 NTU

Answer

EPA's CGP establishes a turbidity benchmark of 280 NTU for most receiving waters, but many state permits set lower benchmarks such as 50 or 100 NTU.

Question 2

Which Clean Water Act section requires states to develop water quality standards and submit them to EPA for approval?

Accepted Answer

Section 303

Answer

Section 303 of the Clean Water Act requires states to establish water quality standards and submit them to EPA for review and approval.

Question 3

What distinguishes a 'narrative criterion' from a 'numeric criterion' in water quality standards?

Accepted Answer

Narrative criteria describe qualitative conditions; numeric criteria specify measurable concentrations or values

Answer

Narrative criteria describe qualitative conditions (e.g., 'no visible sheen') while numeric criteria specify measurable limits for specific pollutants.

Question 4

A construction project near an Outstanding National Resource Water (ONRW) is proposed. Which statement is most accurate regarding water quality protection?

Accepted Answer

No new or increased discharges that cause degradation are allowed

Answer

ONRWs receive the highest level of protection under antidegradation policy — no new or increased discharges that would degrade water quality are permitted.

Question 5

Which pollutant from construction sites is most directly regulated by the TMDL process when a water body is listed as impaired?

Accepted Answer

Sediment/turbidity

Answer

Sediment and turbidity are among the most common reasons water bodies appear on 303(d) impaired waters lists, and TMDLs are developed to address these impairments.

(CPESC) Certified Professional in Erosion and Sediment Control Practice Test

(CPESC) Certified Professional in Erosion and Sediment Control Practice Test

CPESC Water Quality Standards 3