Cross-Connection and Backflow Questions

Cross-connection and backflow devices are part of Distribution System Design on the California D exams and of Distribution System Components on WPI’s distribution exams.

Take the California D2 practice exam

100 questions in the official content counts, with a score for every area and an explanation for every option.

Or try the free backflow drill
  • 14 original backflow questions, every option explained
  • Tested on 10 of our 25 practice exams
Free sample · Question 1 of 3Backflow

An RP assembly is discharging water from its relief port. What does this indicate?

Choose the best answer

What our backflow questions cover

  • Cross-connections, backsiphonage and backpressure
  • Air gaps, RP assemblies, double checks, PVBs and atmospheric vacuum breakers
  • Matching protection to the hazard
  • Testing, records and the supplier’s program
  • Texas customer service inspections
Line drawing of a reduced pressure backflow assembly with two check bodies, a relief port, two shutoff valves and test cocks, beside a hose bib with a vacuum breaker

This list is our own summary, written for practice. The exam owners publish their outlines: California’s Expected Range of Knowledge, TCEQ’s Need-to-Know Criteria and WPI’s Need-to-Know Criteria.

Drill backflow, then sit a full practice exam

Take the California D2 practice exam

100 questions in the official content counts, with a score for every area and an explanation for every option.

Or try the free backflow drill

Ideas the questions test most

  1. An approved air gap is the most reliable protection.
  2. Air gap: twice the supply diameter, at least one inch.
  3. RP assemblies protect high hazards under backpressure.
  4. Test assemblies at least once a year.

Start the free backflow drill · California D2 practice test · California D1 practice test · California D3 practice test · California D4 practice test · TCEQ Class D Water practice test · TCEQ Class C Distribution practice test

Common questions

What is the difference between backsiphonage and backpressure?

Backsiphonage is reverse flow caused by low or negative pressure in the supply; backpressure is reverse flow caused by downstream pressure higher than the supply, such as from a pump or boiler.

Which device protects a high hazard?

An approved air gap or a reduced pressure principle assembly. Double check assemblies are for lower hazards.

Take the California D2 practice exam

100 questions in the official content counts, with a score for every area and an explanation for every option.

Or try the free backflow drill

More operator topics

Outlines used for these questions: Expected Range of Knowledge, Drinking Water Treatment Exam (rev. 4/2020, PDF) · Expected Range of Knowledge, Drinking Water Distribution Exam (rev. 4/2020, PDF) · TCEQ: Need-to-Know Criteria for public water system operators · TCEQ: What applicants for wastewater licenses need to know · WPI: 2025 Need-to-Know Criteria.

Game Assessment Prep is an independent practice site, not affiliated with or endorsed by Water Professionals International (WPI, formerly ABC), the California State Water Resources Control Board or the Texas Commission on Environmental Quality. Every question is original; none is taken from a certification exam, an official study guide or another prep provider.