No direct experience here but ...

No direct experience here but this is what I would look out for….

In anaerobic/anoxic stages of treatment, it may not be a problem (other reactions aside) as it’s a reducer.  However, then it may be concerning for any oxidative stages.

I reread a paper on dechlorination (one of the common uses of sodium bisulphite) that says look out for decreased DO where 4 parts sulfite reacts with 1 part oxygen and lower PH.  

If this is an anticipated effluent, not yet in your loading then I would say it’s worth it to start an ORP monitoring protocol through the various zones. This will give you a baseline of comparison when the chemical loading comes in.  A lot can be learnt from ORP readings through the various biological processes’.   See https://www.ysi.com/ysi-blog/water-blogged-blog/2013/08/orp-management-in-wastewater-as-an-indicator-of-process-efficiency

I would assume there are no disinfecting properties left as its applied at effluent producers point as part of their process or treatment at discharge.  Would be interesting to find out why the industry is using it and see if there are alternatives or better accuracy of dosing if they are off setting an oxidant.   On the discharger side or your side an oxidant as mentioned by Ian could balance the reduction but with variable loading this would be a challenge.    I work with Electro Oxidation systems where I would use direct anodic oxidation technology linked to an ORP control to adjust current/reaction and achieve balance of the influent.