Water distribution math practice, solved step by step
Free math practice for water distribution: the volume of pipes and storage, pressure and head, disinfection dosage, and flow conversions. Work each one on paper, then watch it solved one small step at a time, with a plain-words explanation under every step.
Distribution math topics
Pipe and main volume
A pipe is a long round tank: 0.785 times across times across, times the length, times 7.48.
Practice itPressure and head
Turn feet of elevation into psi with 0.433, and psi back into feet with 2.31.
Practice itMain disinfection dosage
Pounds of chlorine to dose water: flow in MGD times dose in mg/L times 8.34.
Practice itFlow conversions
Move between GPM, GPD, and MGD, the units you read off pumps and meters.
Practice itEvery distribution problem
Work it on paper, then watch it solved one small step at a time.
- How many gallons are in 1,000 feet of 6 inch main?Try it, then watch
- How many gallons are in 800 feet of 12 inch main?Try it, then watch
- How many gallons are in 2,000 feet of 8 inch main?Try it, then watch
- How many gallons are in 500 feet of 24 inch main?Try it, then watch
- How many pounds of chlorine to disinfect a 12,000 gallon main?Try it, then watch
- What percent of the water is lost if 500,000 is pumped and 450,000 delivered?Try it, then watch
- How many gallons are in a 30 foot round tank?Try it, then watch
- How many gallons are in a 12 foot round tank, 10 feet deep?Try it, then watch
- How much pressure does 92 feet of water make?Try it, then watch
- How much pressure does 150 feet of water make?Try it, then watch
- How many feet of head is 50 psi?Try it, then watch
- How much pressure is at the bottom of a 40 foot tank?Try it, then watch
- How many pounds of chlorine for 2 MGD at 3 mg/L?Try it, then watch
- How many pounds of chlorine for 0.5 MGD at 2 mg/L?Try it, then watch
- How do you turn 350 GPM into gallons per day?Try it, then watch
- How many GPM is 1.44 MGD?Try it, then watch
Keep practicing
Common questions
- What math is on a water distribution exam?
- Distribution math is mostly volume of pipes and storage, pressure and head, chlorine dosage for mains, and flow conversions. It uses the same constants as the rest of operator math: 7.48, 8.34, 0.785, 0.433, and 2.31.
- How do you find the gallons in a length of pipe?
- Treat the pipe as a long round tank. Change the diameter from inches to feet, find the circle end with 0.785 times across times across, multiply by the length for cubic feet, then multiply by 7.48 for gallons.
- Are these real exam questions?
- No. Every problem is original teaching material written to practice the same math the job uses. Nothing here predicts your official score.
- Is the practice free?
- Yes. Every worked problem is free, with the full step-by-step walkthrough and a plain-words explanation.
Preparing for the whole exam?
The full Texas Class D prep, when you are ready
These worked problems are free. When you want the full picture, the reviewed question bank covers every Class D subject, with a guided study path, drills, and a timed practice exam.
- Reviewed questions for every Class D subject
- A guided study path that tells you what to do next
- A timed practice exam that mirrors the real format
- Operator math worked step by step, with calculators
$49 a month, cancel anytime, or $129 once for 90 days with no renewal.