CPESC Water Quality Standards 4 — Questions and Answers
Question 1: Which federal law provides the primary framework for regulating wetland fill activities that could impact water quality near construction sites?
- Clean Water Act Section 402
- Clean Water Act Section 404 (Correct answer)
- Resource Conservation and Recovery Act
- National Environmental Policy Act
Correct answer: Clean Water Act Section 404
Section 404 of the Clean Water Act regulates the discharge of dredged or fill material into waters of the US, including wetlands, and is administered jointly by the Army Corps of Engineers and EPA.
Question 2: A stream receiving construction runoff shows a dissolved oxygen (DO) level of 3 mg/L. Most state standards require a minimum DO of 5 mg/L for warm-water fisheries. What impact is most likely?
- Increased algal productivity only
- Fish kills and loss of sensitive aquatic species (Correct answer)
- Improved water clarity due to reduced turbidity
- No significant ecological impact below 4 mg/L
Correct answer: Fish kills and loss of sensitive aquatic species
DO levels below 5 mg/L stress fish and other aquatic life; levels near 3 mg/L can cause fish kills and eliminate sensitive species from the system.
Question 3: What does the term 'use attainability analysis' (UAA) allow states to do regarding designated uses?
- Override federal water quality criteria for specific pollutants
- Demonstrate that attaining a designated use is not feasible and potentially revise it downward (Correct answer)
- Establish higher protective uses than federally required
- Exempt construction sites from water quality monitoring
Correct answer: Demonstrate that attaining a designated use is not feasible and potentially revise it downward
A Use Attainability Analysis (UAA) allows states to demonstrate that certain designated uses cannot be achieved and to downgrade uses if specific physical, chemical, or economic factors make attainment infeasible.
Question 4: Under the construction general permit framework, what is the significance of a water body's 303(d) listing for a permitted construction site?
- The site is automatically exempt from permit requirements
- Additional or more stringent permit conditions may apply to protect the impaired water body (Correct answer)
- Construction must cease until the TMDL is approved
- Only visual monitoring is required near 303(d) listed waters
Correct answer: Additional or more stringent permit conditions may apply to protect the impaired water body
Construction sites discharging to 303(d)-listed impaired waters often face additional permit conditions, more stringent effluent limits, or enhanced BMP requirements.
Question 5: Which parameter best indicates the presence of hydrocarbon contamination (fuel/oil) in stormwater runoff from construction equipment areas?
- Total Dissolved Solids (TDS)
- Oil and grease (O&G) concentration (Correct answer)
- Biochemical oxygen demand (BOD5)
- Nitrate-nitrogen levels
Correct answer: Oil and grease (O&G) concentration
Oil and grease (O&G) monitoring detects petroleum hydrocarbons from fuels, lubricants, and hydraulic fluids commonly associated with construction equipment staging areas.
Question 6: What is the primary role of a stormwater pollution prevention plan (SWPPP) in meeting water quality standards?
- To replace the need for an NPDES permit
- To document BMPs and procedures that prevent pollutants from reaching water bodies (Correct answer)
- To establish site-specific numeric effluent limits
- To certify that no discharges will occur during construction
Correct answer: To document BMPs and procedures that prevent pollutants from reaching water bodies
A SWPPP documents the BMPs, controls, and procedures a site operator will implement to prevent stormwater pollution and achieve compliance with permit conditions protecting water quality.
Question 7: Which chemical characteristic of cement-impacted stormwater runoff poses the greatest threat to aquatic life in receiving streams?
- High turbidity
- Elevated pH (alkalinity) (Correct answer)
- Increased hardness
- Low dissolved oxygen
Correct answer: Elevated pH (alkalinity)
Cement washout and concrete runoff are highly alkaline (pH 11–13), and elevated pH is acutely toxic to fish and aquatic invertebrates sensitive to pH changes.
CPESC Water Quality Standards 4
Which federal law provides the primary framework for regulating wetland fill activities that could impact water quality near construction sites?