CEA Water Quality & Waste Management 2 — Questions and Answers
Question 1: Under the Clean Water Act Section 402, which permit program governs point source discharges of pollutants into navigable waters?
- RCRA
- NPDES (Correct answer)
- CERCLA
- TSCA
Correct answer: NPDES
The National Pollutant Discharge Elimination System (NPDES) under CWA Section 402 regulates point source discharges to navigable waters.
Question 2: A facility discharges wastewater with a biochemical oxygen demand (BOD) of 250 mg/L. What is the primary environmental concern of high BOD in receiving waters?
- Increased turbidity blocking sunlight
- Depletion of dissolved oxygen harming aquatic life (Correct answer)
- Elevated pH causing corrosion
- Increased total dissolved solids
Correct answer: Depletion of dissolved oxygen harming aquatic life
High BOD causes microbial decomposition that consumes dissolved oxygen, creating hypoxic conditions that kill fish and other aquatic organisms.
Question 3: Which RCRA solid waste classification requires the most stringent management standards, including permitted treatment, storage, and disposal facilities?
- Universal waste
- Hazardous waste (Correct answer)
- Special waste
- Non-hazardous industrial waste
Correct answer: Hazardous waste
RCRA Subtitle C hazardous waste requires the most stringent controls, including generator standards, manifest tracking, and permitted TSDFs.
Question 4: An environmental auditor reviewing a municipal solid waste landfill should verify the presence of which federally required component under 40 CFR Part 258?
- Double-liner system with leachate collection
- Composite liner with leachate collection and detection system (Correct answer)
- Clay liner with groundwater monitoring wells only
- Synthetic liner with gas venting system only
Correct answer: Composite liner with leachate collection and detection system
40 CFR Part 258 (Subtitle D) requires municipal solid waste landfills to have a composite liner system and leachate collection and removal system.
Question 5: Which parameter is used to characterize the acidity or alkalinity of wastewater and must be maintained within a specific range for effective biological treatment?
- Total suspended solids (TSS)
- Chemical oxygen demand (COD)
- pH (Correct answer)
- Total kjeldahl nitrogen (TKN)
Correct answer: pH
pH must typically be maintained between 6.5–8.5 for effective biological wastewater treatment, as extreme values inhibit microbial activity.
Question 6: A hazardous waste generator produces 950 kg of hazardous waste per month. Under RCRA, which generator category applies?
- Very Small Quantity Generator (VSQG)
- Small Quantity Generator (SQG) (Correct answer)
- Large Quantity Generator (LQG)
- Conditionally exempt generator
Correct answer: Small Quantity Generator (SQG)
Small Quantity Generators (SQGs) generate between 100 kg and 1,000 kg of hazardous waste per month under RCRA regulations.
Question 7: During a water quality audit, an auditor finds elevated nitrate concentrations (18 mg/L as N) in a public water supply. What is the primary health concern associated with this finding?
- Liver damage in adults
- Methemoglobinemia in infants (Correct answer)
- Increased cancer risk in elderly populations
- Kidney disease in children
Correct answer: Methemoglobinemia in infants
Nitrate above the MCL of 10 mg/L as N can cause methemoglobinemia (blue baby syndrome) in infants by reducing the blood's oxygen-carrying capacity.
CEA Water Quality & Waste Management 2
Under the Clean Water Act Section 402, which permit program governs point source discharges of pollutants into navigable waters?