Question 97General Subjects - 1st Asst/Chief

70% to pass

What is used to prevent contamination of a potable water system supplying a plumbing fixture such as a galley sink from a backup of sewage sanitary drains?

ALocation of the potable water spigots below the rim of the galley sink.
BCheck valves in the potable water supply lines delivering water to the galley sink.
CA "P" trap in the drain line draining sewage waste from the galley sink.
DLocation of the potable water spigots above the rim of the galley sink.
AI Explanation

The correct answer is D) Location of the potable water spigots above the rim of the galley sink. This is the correct answer because having the potable water spigots located above the rim of the galley sink prevents the possibility of contamination from a backup of sewage or sanitary drains. By positioning the water supply above the sink, there is no risk of the water flowing back into the potable water system, even if there is a drain clog or backflow in the sink's drain line. The other options are incorrect because they do not effectively prevent contamination. Check valves can fail, a "P" trap only prevents backflow from the drain line itself, and locating the spigots below the sink rim still leaves the potential for backflow into the potable water system.

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