MASSACHUSETTS WASTEWATER
OPERATOR GRADE 1 EXAM
QUESTIONS AND
VERIFIED ANSWERS
WITH RATIONALES
JUST RELEASED
EXAM SPECIFICATIONS
Time Allocation: 2 Hours
Total Questions: 100 Questions
Question Format: Multiple Choice with Math Problems
Minimum Competency: 70% Required to Pass
Core Focus: Basic Treatment, Collection, Safety, Math, Regulations
MA Wastewater Operator Grade 1 Exam Just Released Page 1
, Exam Overview & Content Outline
EXAM PURPOSE
Massachusetts Wastewater Operator Grade 1 Exam covers basic wastewater treatment operations,
collection systems, safety, and fundamental calculations per Massachusetts DEP 257 CMR 2.00.
Entry-level certification for municipal wastewater treatment plant operators.
CONTENT DISTRIBUTION
• Basic Treatment Processes (30%) — Primary treatment, secondary treatment, disinfection,
preliminary treatment
• Collection Systems (25%) — Gravity sewers, manholes, lift stations, I&I;, maintenance, safety
• Safety & Regulations (25%) — OSHA confined space, lockout/tagout, PPE, MA DEP regulations,
NPDES basics
• Mathematics & Operations (20%) — Flow, detention time, surface loading, weir overflow, basic
calculations
QUESTION FORMAT & SCORING
Each item presents four options. Correct answers are highlighted in green with checkmark (✓).
Every question includes detailed rationale with MA DEP references. Requires 70% to pass.
STUDY STRATEGY
Master basic treatment: screening, grit removal, primary clarification, activated sludge basics,
chlorination. Know collection system components and maintenance. Understand confined space
entry procedures. Study MA DEP 257 CMR 2.00 and 314 CMR. Practice basic math: area, volume,
flow, detention time, pounds formula.
CURRICULUM ALIGNMENT
Questions reflect current standards: Massachusetts DEP 257 CMR 2.00 (Operator Certification), 314
CMR (Water Pollution Control), OSHA 29 CFR 1910, and basic wastewater treatment principles.
MA Wastewater Operator Grade 1 Exam Just Released Page 2
, SECTION I: Basic Treatment Processes
1. Primary treatment removes:
A. Dissolved organics
✓ B. Settleable solids and floatables
C. Nitrogen
D. Phosphorus
Rationale: Primary treatment: Physical process removing settleable solids and floatables. Includes
screening, grit removal, primary clarification. Removes 25-40% BOD, 50-70% TSS. Detention time 1.5-2.5
hours. Surface overflow rate 800-1200 gpd/sf. Does NOT remove dissolved constituents. Secondary
treatment removes dissolved organics via biological process.
2. Secondary treatment process uses:
A. Chlorine only
✓ B. Microorganisms to consume organic matter
C. Sand filters only
D. UV light only
Rationale: Secondary treatment: Biological process. Microorganisms (bacteria, protozoa) consume
dissolved organic matter (BOD). Types: Activated sludge, trickling filters, RBCs, lagoons. Requires oxygen
(aerobic). Removes 85-95% BOD and TSS. Produces secondary sludge. MA Grade 1 must understand
basic biology of treatment.
3. Disinfection with chlorine requires:
A. No contact time
✓ B. Contact time 15-30 minutes, residual 0.5-1.0 mg/L
C. 1 minute contact
D. No residual
Rationale: Chlorination: Contact time 15-30 minutes at peak flow for fecal coliform kill. Residual 0.5-1.0 mg/L
after contact. CT = Concentration × Time. Dechlorination required before discharge if chlorine toxic to
receiving water. Alternatives: UV, ozone. MA NPDES permits specify fecal coliform limits 200 cfu/100mL.
4. Grit removal purpose:
A. Remove BOD
✓ B. Remove sand, gravel, cinders to protect equipment
C. Remove nitrogen
D. Disinfection
Rationale: Grit: Sand, gravel, cinders, eggshells - inorganic, heavy. Removed in grit chambers (velocity 1
ft/sec) or aerated grit. Prevents wear on pumps, pipes, reduces volume in digesters. Not biodegradable.
Disposed to landfill. If not removed: accumulates in primary clarifiers, reduces capacity, damages
equipment.
5. Bar screen purpose:
MA Wastewater Operator Grade 1 Exam Just Released Page 3
OPERATOR GRADE 1 EXAM
QUESTIONS AND
VERIFIED ANSWERS
WITH RATIONALES
JUST RELEASED
EXAM SPECIFICATIONS
Time Allocation: 2 Hours
Total Questions: 100 Questions
Question Format: Multiple Choice with Math Problems
Minimum Competency: 70% Required to Pass
Core Focus: Basic Treatment, Collection, Safety, Math, Regulations
MA Wastewater Operator Grade 1 Exam Just Released Page 1
, Exam Overview & Content Outline
EXAM PURPOSE
Massachusetts Wastewater Operator Grade 1 Exam covers basic wastewater treatment operations,
collection systems, safety, and fundamental calculations per Massachusetts DEP 257 CMR 2.00.
Entry-level certification for municipal wastewater treatment plant operators.
CONTENT DISTRIBUTION
• Basic Treatment Processes (30%) — Primary treatment, secondary treatment, disinfection,
preliminary treatment
• Collection Systems (25%) — Gravity sewers, manholes, lift stations, I&I;, maintenance, safety
• Safety & Regulations (25%) — OSHA confined space, lockout/tagout, PPE, MA DEP regulations,
NPDES basics
• Mathematics & Operations (20%) — Flow, detention time, surface loading, weir overflow, basic
calculations
QUESTION FORMAT & SCORING
Each item presents four options. Correct answers are highlighted in green with checkmark (✓).
Every question includes detailed rationale with MA DEP references. Requires 70% to pass.
STUDY STRATEGY
Master basic treatment: screening, grit removal, primary clarification, activated sludge basics,
chlorination. Know collection system components and maintenance. Understand confined space
entry procedures. Study MA DEP 257 CMR 2.00 and 314 CMR. Practice basic math: area, volume,
flow, detention time, pounds formula.
CURRICULUM ALIGNMENT
Questions reflect current standards: Massachusetts DEP 257 CMR 2.00 (Operator Certification), 314
CMR (Water Pollution Control), OSHA 29 CFR 1910, and basic wastewater treatment principles.
MA Wastewater Operator Grade 1 Exam Just Released Page 2
, SECTION I: Basic Treatment Processes
1. Primary treatment removes:
A. Dissolved organics
✓ B. Settleable solids and floatables
C. Nitrogen
D. Phosphorus
Rationale: Primary treatment: Physical process removing settleable solids and floatables. Includes
screening, grit removal, primary clarification. Removes 25-40% BOD, 50-70% TSS. Detention time 1.5-2.5
hours. Surface overflow rate 800-1200 gpd/sf. Does NOT remove dissolved constituents. Secondary
treatment removes dissolved organics via biological process.
2. Secondary treatment process uses:
A. Chlorine only
✓ B. Microorganisms to consume organic matter
C. Sand filters only
D. UV light only
Rationale: Secondary treatment: Biological process. Microorganisms (bacteria, protozoa) consume
dissolved organic matter (BOD). Types: Activated sludge, trickling filters, RBCs, lagoons. Requires oxygen
(aerobic). Removes 85-95% BOD and TSS. Produces secondary sludge. MA Grade 1 must understand
basic biology of treatment.
3. Disinfection with chlorine requires:
A. No contact time
✓ B. Contact time 15-30 minutes, residual 0.5-1.0 mg/L
C. 1 minute contact
D. No residual
Rationale: Chlorination: Contact time 15-30 minutes at peak flow for fecal coliform kill. Residual 0.5-1.0 mg/L
after contact. CT = Concentration × Time. Dechlorination required before discharge if chlorine toxic to
receiving water. Alternatives: UV, ozone. MA NPDES permits specify fecal coliform limits 200 cfu/100mL.
4. Grit removal purpose:
A. Remove BOD
✓ B. Remove sand, gravel, cinders to protect equipment
C. Remove nitrogen
D. Disinfection
Rationale: Grit: Sand, gravel, cinders, eggshells - inorganic, heavy. Removed in grit chambers (velocity 1
ft/sec) or aerated grit. Prevents wear on pumps, pipes, reduces volume in digesters. Not biodegradable.
Disposed to landfill. If not removed: accumulates in primary clarifiers, reduces capacity, damages
equipment.
5. Bar screen purpose:
MA Wastewater Operator Grade 1 Exam Just Released Page 3
