CPESC Water Quality Standards 2 — Questions and Answers
Question 1: Under the Clean Water Act, which section specifically establishes the NPDES permit program for point source discharges?
- Section 303
- Section 401
- Section 402 (Correct answer)
- Section 404
Correct answer: Section 402
Section 402 of the Clean Water Act establishes the National Pollutant Discharge Elimination System (NPDES) permit program regulating point source discharges.
Question 2: What term describes the maximum amount of a pollutant a water body can receive while still meeting water quality standards?
- Effluent Limitation Guideline
- Total Maximum Daily Load (TMDL) (Correct answer)
- Numeric Effluent Limit
- Waste Load Allocation
Correct answer: Total Maximum Daily Load (TMDL)
A Total Maximum Daily Load (TMDL) is the calculated maximum amount of a pollutant that a waterbody can receive daily while still meeting water quality standards.
Question 3: Which parameter is most commonly used to assess the oxygen demand of organic matter in stormwater runoff?
- Total Suspended Solids (TSS)
- Biochemical Oxygen Demand (BOD) (Correct answer)
- Nitrate concentration
- pH level
Correct answer: Biochemical Oxygen Demand (BOD)
Biochemical Oxygen Demand (BOD) measures the amount of oxygen consumed by biological processes breaking down organic matter, indicating organic pollution levels.
Question 4: A construction site discharges sediment-laden water with a turbidity of 500 NTU into a receiving stream. The in-stream standard is 50 NTU. Which regulatory action is most likely?
- Issuance of a variance
- Notice of Violation and required corrective action (Correct answer)
- Automatic permit termination
- Suspension of water quality standards
Correct answer: Notice of Violation and required corrective action
Exceeding in-stream turbidity standards typically results in a Notice of Violation requiring immediate corrective action to bring discharge into compliance.
Question 5: What is the primary purpose of antidegradation policy in water quality standards?
- To set numeric criteria for toxic pollutants
- To protect existing water quality and uses from further deterioration (Correct answer)
- To establish effluent limits for industrial facilities
- To define the 303(d) listing process
Correct answer: To protect existing water quality and uses from further deterioration
Antidegradation policy protects existing water quality and designated uses, preventing degradation of waters that already meet standards.
Question 6: Which of the following best defines 'designated uses' in the context of water quality standards?
- The current actual use of a water body
- The intended goals established by states for protecting and using water bodies (Correct answer)
- Uses permitted under NPDES general permits
- Federally mandated uses for all navigable waters
Correct answer: The intended goals established by states for protecting and using water bodies
Designated uses are the intended purposes (e.g., aquatic life support, recreation, drinking water) that states establish to guide water quality standards development.
Question 7: Phosphorus loading from construction site runoff primarily contributes to which water quality problem in receiving water bodies?
- Acidification
- Eutrophication and algal blooms (Correct answer)
- Heavy metal contamination
- Increased turbidity only
Correct answer: Eutrophication and algal blooms
Phosphorus is a key nutrient that drives eutrophication — excessive algal growth that depletes dissolved oxygen and harms aquatic ecosystems.
CPESC Water Quality Standards 2
Under the Clean Water Act, which section specifically establishes the NPDES permit program for point source discharges?