Environmental Compliance Inspector Environmental Compliance Inspector Water Quality Compliance Questions and Answers 2 — Questions and Answers
Question 1: Under the Clean Water Act, what is the primary purpose of a National Pollutant Discharge Elimination System (NPDES) permit?
- To regulate point source discharges of pollutants into waters of the United States (Correct answer)
- To set drinking water standards for public water systems
- To authorize the filling of wetlands for commercial development
- To exempt industrial facilities from stormwater monitoring
Correct answer: To regulate point source discharges of pollutants into waters of the United States
NPDES permits regulate point source discharges into U.S. waters under Section 402 of the Clean Water Act.
Question 2: What does the term 'mixing zone' refer to in water quality compliance?
- A designated area where treated effluent is blended before discharge
- An area near a discharge point where water quality standards may be exceeded (Correct answer)
- A laboratory procedure for combining water samples
- A section of a treatment plant where chemicals are added
Correct answer: An area near a discharge point where water quality standards may be exceeded
A mixing zone is a limited area near a discharge point where dilution occurs and numeric water quality criteria may be exceeded.
Question 3: Which parameter is most commonly used to measure the oxygen-demanding strength of wastewater?
- Total Dissolved Solids (TDS)
- Chemical Oxygen Demand (COD)
- Biochemical Oxygen Demand (BOD) (Correct answer)
- Turbidity (NTU)
Correct answer: Biochemical Oxygen Demand (BOD)
BOD measures the amount of dissolved oxygen consumed by microorganisms to decompose organic matter in wastewater over a standard five-day period.
Question 4: During a compliance inspection, an inspector discovers a facility is discharging above its permitted daily maximum limit for total suspended solids. What is this classified as?
- A minor administrative deficiency
- An effluent limit exceedance (Correct answer)
- A best management practice deviation
- A pretreatment program violation
Correct answer: An effluent limit exceedance
Exceeding a permitted daily maximum for any parameter constitutes an effluent limit exceedance, which is a direct permit violation.
Question 5: What is the purpose of a Discharge Monitoring Report (DMR) submitted by a permitted facility?
- To request modifications to existing permit conditions
- To document self-monitored effluent data and demonstrate compliance with permit limits (Correct answer)
- To report workplace safety incidents at the treatment facility
- To apply for renewal of an expiring NPDES permit
Correct answer: To document self-monitored effluent data and demonstrate compliance with permit limits
DMRs are periodic reports where permittees document their self-monitoring results to demonstrate compliance with NPDES permit effluent limits.
Question 6: Which of the following best describes a Total Maximum Daily Load (TMDL)?
- The maximum volume of water a treatment plant can process in 24 hours
- A calculation of the maximum amount of a pollutant a water body can receive and still meet water quality standards (Correct answer)
- The total weight of sludge a facility may dispose of per day
- A federal limit on the number of discharge permits issued per watershed
Correct answer: A calculation of the maximum amount of a pollutant a water body can receive and still meet water quality standards
A TMDL establishes the maximum amount of a specific pollutant that a water body can assimilate while still meeting applicable water quality standards.
Environmental Compliance Inspector Environmental Compliance Inspector Water Quality Compliance Questions and Answers 2
Under the Clean Water Act, what is the primary purpose of a National Pollutant Discharge Elimination System (NPDES) permit?