T2 Water Treatment Practice Test (California)

Administered by State Water Resources Control Board (SWRCB) — Division of Drinking Water

Same category weights as T1; the difference is 45 additional objectives. Passing the T3 exam also qualifies for T2 certification.

California's certificate for running a drinking water treatment plant.

Start studying T2

Official formula sheet

T2 eligibility

To sit the T2 exam

To be certified at T2

How the T2 exam is weighted

Content areaquestions of 100
Source Water25
Water Treatment Processes25
Operation / Maintenance20
Laboratory Procedures15
Regulations / Administrative Duties15

T2 exam format

T2 pass rate

61% of examinees passed (814 of 1,344) from July 1, 2025 to June 30, 2026. Source: SWRCB Drinking Water Operator Certification Program, Water Treatment Exam Results (through 6/30/2026). The agency updates these tables every six months.

T2 sample question

Chemical feed: pounds formula · an original practice item written only from publicly available sources, not a real exam question

A plant treats 1.5 million gallons per day (MGD) and needs a chlorine dose of 3.2 mg/L. How many pounds of chlorine per day is that?

  1. 4.80 lb/day
  2. 17.8 lb/day
  3. 26.7 lb/day
  4. 40.0 lb/day
Answer and working

D. 40.0 lb/day

Pounds per day = flow (MGD) × dose (mg/L) × 8.34 lb/gal = 1.5 × 3.2 × 8.34 = 40.0 lb/day. 4.80 drops the 8.34 conversion factor, 17.8 divides by the flow instead of multiplying (3.2 × 8.34 ÷ 1.5), and 26.7 leaves the flow out altogether (3.2 × 8.34).

T2 questions answered

What do I need to sit the T2 treatment exam?
High school diploma or GED. One specialized course covering the fundamentals of drinking water treatment. The high school diploma or GED requirement can also be met by completing the State Water Board Basic Small Water Systems Operations course, or by one year operating a facility that required an understanding of chemical feeds, hydraulics and pumps (treatment) or piping, pumps, valves and storage tanks (distribution).
How is the T2 exam weighted?
Source Water: 25; Water Treatment Processes: 25; Operation / Maintenance: 20; Laboratory Procedures: 15; Regulations / Administrative Duties: 15 (of 100 questions).
What is the recent T2 pass rate?
61%: 814 of 1,344 examinees passed from July 1, 2025 to June 30, 2026, summed from the agency's two half-year results tables.

What this exam covers

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Other grades in this track

Grade T1 — Entry level · Grade T3 · Grade T4 · Grade T5 — Chief operator · All Water Treatment grades

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Sources

Topic coverage follows Expected Range of Knowledge for Drinking Water Treatment Exam (SWRCB Division of Drinking Water, rev. 4/2020). Practice questions are written only from publicly available sources (that outline and the regulations and references it cites); they are not real exam questions, which are confidential. Check current application requirements, fees and exam dates on the certifying body's own page: official certification page.

Questions, flashcards, and explanations are AI-written from publicly available sources only: the exam content outlines and candidate materials each certifying body publishes without restriction, and the regulations and technical references they cite. No confidential material is used, including actual exam questions, recollections of any exam sat by the author, or any handbook or document released under a confidentiality agreement. Content is then put through repeated review — regulatory values checked against primary sources, every calculation recomputed, and errors corrected — plus spot checks by the author, who holds California water operator certifications and a California civil engineering licence. Those spot checks are sampling, not a professional review: nothing here is stamped, sealed, or offered as engineering advice, and not every item has been individually verified, so mistakes can still slip through.