Ablutions

 is a side quest in the Fallout 4 add-on Far Harbor.

Synopsis
Sister Mai is working on restoring the decontamination arches at the Nucleus entrance to act as a tool for ablutions: Spraying the faithful with heavily irradiated water and bring them the Glow. However, she's missing a pump regulator to make it work...

Walkthrough

 * 1) Head to the Vim! Pop factory. Enter the factory proper, killing mutants as you go.
 * 2) Find the pump regulator on a table in the upper office overlooking the mixing vats in the southern hall.
 * 3) Return to Sister Mai. She will request that you install it.
 * 4) Optional: With persuasion, convince Mai to pay you, starting at 150 caps and going up to 350.
 * 5) Head down to the bay. The decontamination pump is by the sub's tail, at the bottom.
 * 6) Install the pump regulator. With Intelligence 7 or more, you can remove Mai's alterations, hide them, and repair the decontamination arches completely, allowing you to have a free source of decontamination.
 * 7) Return upstairs and press the button to complete the quest.