How to Be a Mikveh Attendant:

What is the precise halachic role of a mikveh attendant? I have been asked this a number of times, and here I  share some general thoughts.

Truth be told, it is very limited, there is but one obligation. In the words of the Shuchan Aruch:

"When a woman immerses, there needs to stand next to her an adult Jewess, who is at least 12 years and 1 day old, who can observe if any hair of her head is floating above the water..." (Yoreh De'ah 198.40)
In other words, a mikveh attendant's role is to make sure that the woman's hair is completely submerged in the water.  Everything else, from checking for dirt under the nails to sifting through loose hairs and the like, are extraneous customs grounded in any number of the following: local tradition, piety, ignorance, or a desire to keep the mikvah clean. In the view if the Shulchan Aruch, a woman is trusted to check her own body without assistance and she is trusted to immerse the entire body completely, with the sole, exceptional, concern of the hair. In fact, were it the case that a mikvah attendant could not be found (and one's husband is not available), the Shulchan Aruch goes on to state as follows:

"If there is no one to stand next to her, or in the (darkness) of night [whereby it is difficult to see floating hair], she should wrap her head using hair-thread that does not impede, or wool thread, or (use) a strap upon her head, so long as it be loose or the coils of thread are mesh-like. Alternatively, she may put a loose cloth over her head." (YD 198.40)

The latter is echoed by the Aruch HaShulchan and Rav Obadiah Yosef. (A.H. YD 198.87; Taharat HaBayith Vol III:45 #172) Similarly, Rav Yitzchak Abadi recommends that a hairnet be used when no attendant can be found. (Or Yitzchak Vol. I #29 Page 304)

Not to put to fine a point on it, the Maharshak rules 'that if a woman is fastidious and does not fear the water, she can grasp her hair with her hand (to keep it down), immerse to a good depth, and then let go of her hair underneath the water.'  (Tifereth Shmuel -Commentary on Rosh's Hilchot Mikvaoth #28) The latter is cited approvingly by the Aruch Hashulchan among other authorities. (A.H. YD 198.87; Pischei Teshuva YD 198.43; Taharat HaBayith ibid; Otzer Meforshim YD 198:40-- in Shulchan Aruch HaBahir)

Although it is not recommended by this author or anyone else to do this without proper consultation, nevertheless, by appeal to unusual circumstance, the general point is made abundantly clear. The halachic obligation of a mikveh attendant, though quite important, it is rather limited in scope. In light of this, perhaps it is time to reframe the emphasis of the conversation. The question is not 'what are the halachic obligations of the mikvah attendant?' rather the question ought to be 'what are her human obligations?'

A few suggestions:
To be respectful and warm, to offer help when it is asked for, to shy away from criticism of any kind, not to touch unless prompted, to keep the confidences of others, to embody the Ahavat Yisrael esteemed by our matriarchs of old....