New Jersey Water Treatment Operator T1 Exam 2026 |
100 Practice Questions with Verified Answers –
NJDEP T1 Certification Study Guide | instant pdf
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Introduction
This comprehensive study guide contains 100 practice questions for the New Jersey Water
Treatment Operator T1 (Entry-Level) Certification Exam, based on the NJDEP Water
Supply Division regulations and the New Jersey Administrative Code (NJAC) 7:10 . The T1
exam covers source water protection, coagulation/flocculation, sedimentation, filtration,
disinfection, water quality monitoring, laboratory procedures, regulatory compliance, safety
protocols, and basic water math . All answers are presented in bold italics with detailed
rationales following each response.
Domain 1: Regulations and Standards (Questions 1-15)
Q1. Under NJDEP regulations, the maximum contaminant level (MCL) for arsenic in
drinking water is:
A) 5 ppb
B) 10 ppb
C) 15 ppb
D) 50 ppb
Answer: B – 10 ppb
Explanation The MCL for arsenic is 10 ppb (0.010 mg/L) to reduce cancer risk from long-
term exposure .
Q2. The action level for lead at the consumer's tap under the Lead and Copper Rule
is:
A) 5 ppb
B) 10 ppb
C) 15 ppb
D) 50 ppb
,Answer: C – 15 ppb
Explanation The action level for lead is 15 ppb; exceeding this level requires corrosion
control treatment and public education .
Q3. The action level for copper under the Lead and Copper Rule is:
A) 0.5 ppm
B) 1.0 ppm
C) 1.3 ppm
D) 2.0 ppm
Answer: C – 1.3 ppm
Explanation The action level for copper is 1.3 ppm. Exceeding this level triggers corrosion
control requirements .
Q4. Under NJDEP regulations, the MCL for nitrate (as nitrogen) in drinking water is:
A) 5 mg/L
B) 10 mg/L
C) 15 mg/L
D) 20 mg/L
Answer: B – 10 mg/L
Explanation The MCL for nitrate (as N) is 10 mg/L to prevent methemoglobinemia ("blue
baby syndrome") in infants .
Q5. Which of the following is a secondary MCL (esthetic standard) for drinking
water?
A) Arsenic 10 ppb
B) Iron 0.3 ppm
C) Nitrate 10 ppm
D) Barium 2 ppm
Answer: B – Iron 0.3 ppm
Explanation Secondary MCLs address esthetic concerns (taste, odor, color). Iron (0.3 ppm)
and manganese (0.05 ppm) are secondary standards. Arsenic, nitrate, and barium are
primary MCLs .
, Q6. Under NJAC 7:10, what is the minimum free chlorine residual required at the
point where treated water enters the distribution system?
A) 0.05 mg/L
B) 0.2 mg/L
C) 1.0 mg/L
D) 2.0 mg/L
Answer: B – 0.2 mg/L
Explanation Regulations require at least 0.2 mg/L free chlorine residual at the entry point to
ensure adequate protection throughout the distribution system .
Q7. The Safe Drinking Water Act (SDWA) is primarily administered in New Jersey by
which agency?
A) US EPA
B) NJ Department of Environmental Protection (NJDEP) – Water Supply Division
C) NJ Department of Health
D) NJ Board of Public Utilities
Answer: B – NJDEP Water Supply Division
Explanation The NJDEP Water Supply Division administers the SDWA in New Jersey
through NJAC 7:10, which establishes state-specific primary and secondary drinking water
standards .
Q8. Under the Revised Total Coliform Rule, a water sample that tests positive for total
coliform must be:
A) Immediately shock-chlorinated
B) Tested specifically for E. coli
C) Disregarded if chlorine residual is above 1.0 mg/L
D) Flushed and retested within 24 hours
Answer: B – Tested specifically for E. coli
Explanation When a sample tests positive for total coliform, follow-up testing for E. coli is
required. The presence of E. coli indicates recent fecal contamination and requires
immediate action .
Q9. Two coliform-positive samples within 30 days trigger what action under NJAC
7:10?
100 Practice Questions with Verified Answers –
NJDEP T1 Certification Study Guide | instant pdf
download
Introduction
This comprehensive study guide contains 100 practice questions for the New Jersey Water
Treatment Operator T1 (Entry-Level) Certification Exam, based on the NJDEP Water
Supply Division regulations and the New Jersey Administrative Code (NJAC) 7:10 . The T1
exam covers source water protection, coagulation/flocculation, sedimentation, filtration,
disinfection, water quality monitoring, laboratory procedures, regulatory compliance, safety
protocols, and basic water math . All answers are presented in bold italics with detailed
rationales following each response.
Domain 1: Regulations and Standards (Questions 1-15)
Q1. Under NJDEP regulations, the maximum contaminant level (MCL) for arsenic in
drinking water is:
A) 5 ppb
B) 10 ppb
C) 15 ppb
D) 50 ppb
Answer: B – 10 ppb
Explanation The MCL for arsenic is 10 ppb (0.010 mg/L) to reduce cancer risk from long-
term exposure .
Q2. The action level for lead at the consumer's tap under the Lead and Copper Rule
is:
A) 5 ppb
B) 10 ppb
C) 15 ppb
D) 50 ppb
,Answer: C – 15 ppb
Explanation The action level for lead is 15 ppb; exceeding this level requires corrosion
control treatment and public education .
Q3. The action level for copper under the Lead and Copper Rule is:
A) 0.5 ppm
B) 1.0 ppm
C) 1.3 ppm
D) 2.0 ppm
Answer: C – 1.3 ppm
Explanation The action level for copper is 1.3 ppm. Exceeding this level triggers corrosion
control requirements .
Q4. Under NJDEP regulations, the MCL for nitrate (as nitrogen) in drinking water is:
A) 5 mg/L
B) 10 mg/L
C) 15 mg/L
D) 20 mg/L
Answer: B – 10 mg/L
Explanation The MCL for nitrate (as N) is 10 mg/L to prevent methemoglobinemia ("blue
baby syndrome") in infants .
Q5. Which of the following is a secondary MCL (esthetic standard) for drinking
water?
A) Arsenic 10 ppb
B) Iron 0.3 ppm
C) Nitrate 10 ppm
D) Barium 2 ppm
Answer: B – Iron 0.3 ppm
Explanation Secondary MCLs address esthetic concerns (taste, odor, color). Iron (0.3 ppm)
and manganese (0.05 ppm) are secondary standards. Arsenic, nitrate, and barium are
primary MCLs .
, Q6. Under NJAC 7:10, what is the minimum free chlorine residual required at the
point where treated water enters the distribution system?
A) 0.05 mg/L
B) 0.2 mg/L
C) 1.0 mg/L
D) 2.0 mg/L
Answer: B – 0.2 mg/L
Explanation Regulations require at least 0.2 mg/L free chlorine residual at the entry point to
ensure adequate protection throughout the distribution system .
Q7. The Safe Drinking Water Act (SDWA) is primarily administered in New Jersey by
which agency?
A) US EPA
B) NJ Department of Environmental Protection (NJDEP) – Water Supply Division
C) NJ Department of Health
D) NJ Board of Public Utilities
Answer: B – NJDEP Water Supply Division
Explanation The NJDEP Water Supply Division administers the SDWA in New Jersey
through NJAC 7:10, which establishes state-specific primary and secondary drinking water
standards .
Q8. Under the Revised Total Coliform Rule, a water sample that tests positive for total
coliform must be:
A) Immediately shock-chlorinated
B) Tested specifically for E. coli
C) Disregarded if chlorine residual is above 1.0 mg/L
D) Flushed and retested within 24 hours
Answer: B – Tested specifically for E. coli
Explanation When a sample tests positive for total coliform, follow-up testing for E. coli is
required. The presence of E. coli indicates recent fecal contamination and requires
immediate action .
Q9. Two coliform-positive samples within 30 days trigger what action under NJAC
7:10?
