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State Example Questions

C-55 Water Conditioning Contractor

NOTE: All questions are written and reviewed by licensed contractors who are actively working in the field.

The following questions are typical of the kind of items that are on the examination.

The correct answer is highlighted.


  1. Which of the following components should a contractor use to attach the drain line from a reverse osmosis unit to the drain system?

    • a. p-trap
    • b. Saddle valve
    • c. Angle stop
    • d. Air gap

  2. When installing hard copper piping underground, what types of piping should a contractor use?

    • a. L and M
    • b. K and M
    • c. K and L
    • d. M and DWV

  3. What is the function of a cation exchange unit?

    • a Remove calcium and magnesium
    • b. Oxidize iron from the water
    • c. Reduce dissolved solids
    • d. Increase pH