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Water & Wastewater Operator (WPI/ABC Class I) — Practice Exam

WW effluent: practice questions

Our Water/Wastewater Operator bank has 6 questions on this topic. Here are 5 of them with answers; the full mock exam draws from every topic, like the real one.

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Question 1 · Wastewater Treatment Class I

What effluent pH range do secondary treatment standards require?

  1. 4.0 to 10.0
  2. 5.0 to 7.0
  3. 6.0 to 9.0
  4. 7.0 to 8.0
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C. 6.0 to 9.0 — 40 CFR 133.102(c).

Question 2 · Wastewater Treatment Class I

Under federal secondary treatment standards, what is the 30-day average limit for BOD₅?

  1. 10 mg/L
  2. 30 mg/L
  3. 45 mg/L
  4. 85 mg/L
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B. 30 mg/L — 40 CFR 133.102; the 7-day average is 45 mg/L.

Question 3 · Wastewater Treatment Class I

What minimum 30-day average removal of BOD₅ and TSS do secondary treatment standards require?

  1. 50%
  2. 65%
  3. 85%
  4. 95%
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C. 85% — 40 CFR 133.102.

Question 4 · Wastewater Treatment Class I

What is a rapid infiltration basin (RIB)?

  1. A digester
  2. A grit chamber that removes sand quickly at the headworks of the plant
  3. An aerated lagoon
  4. A basin where treated effluent soaks into the ground
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D. A basin where treated effluent soaks into the ground — Effluent disposal options include surface water and land.

Question 5 · Wastewater Treatment Class I

What permit authorizes a wastewater plant to discharge to surface water?

  1. A building permit
  2. An NPDES permit
  3. A drinking water permit
  4. An air permit
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B. An NPDES permit — Under the Clean Water Act.

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