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Coagulation and sedimentation basins at a drinking-water treatment plant

Pennsylvania · Water Treatment · Class E

Pennsylvania Grade 1 Water Treatment Operator Exam

The Pennsylvania Grade 1 water treatment certification is designated Class E and issued by Pennsylvania Department of Environmental Protection (PA DEP). Entry-level certification for operators at small systems or working under direct supervision.

Photo: U.S. EPA (public domain)

Applied math is a significant part of the Pennsylvania Class E exam.

Practicing calculations like dosage, detention time, and loading before test day is one of the most effective ways to prepare, alongside reviewing your state’s official exam content outline.

Exam facts

Exam facts
Grade levelClass E
Questions100
Time limit120 minutes
Passing score70%
DifficultyEntry
Exam administered byAssociation of Boards of Certification (ABC)

Prerequisites for Class E

  • High school diploma or GED
  • 0–1 year of operating experience (varies by state)

Confirm exact requirements with Pennsylvania Department of Environmental Protection (PA DEP).

What's on the exam

  • Coagulation and flocculation
  • Sedimentation and clarification
  • Filtration (conventional, direct, membrane)
  • Disinfection and disinfection byproducts
  • Corrosion control and stabilization
  • Source water and watershed protection
  • Basic operations and monitoring
  • Recordkeeping and reporting

The math on the Water Treatment exam

These calculations are commonly included in water treatment operator exam preparation and may appear on your exam depending on your certification level and state. Practicing them is one of the most effective ways to prepare.

  • Chemical dosage (mg/L to lbs/day)
  • Chlorine demand and CT calculations
  • Detention time
  • Filter loading and backwash rate
  • Flow rate and velocity
  • Percent strength of solutions

Free Class E practice questions

Sample questions with full explanations at this level.

Take the practice quiz →

Frequently asked questions

What is the Pennsylvania Grade 1 water treatment certification called?
In Pennsylvania, the Grade 1 water treatment certification is designated Class E, issued by Pennsylvania Department of Environmental Protection (PA DEP).
How many questions are on the exam and what score do I need?
The exam has about 100 questions with a 120-minute time limit, and you need 70% to pass. It is administered by Association of Boards of Certification (ABC).
What are the prerequisites for Class E in Pennsylvania?
Typical prerequisites: High school diploma or GED; 0–1 year of operating experience (varies by state). Exact requirements are set by Pennsylvania Department of Environmental Protection (PA DEP).