If they are private washing machines and dryers then the owners of those appliances can’t put them on common property without the permission of the OC. So strictly speaking the OC could remove them – although based on what Harmony has said it might be difficult to get a resolution for removal.
However, I suggest you use that as a starting point – if those owners want to put their machines on common property they need the permission of the OC, and that should come with conditions, i.e. that the owners pay for the electricity use. Why don’t you speak to an electrician about the options available to work out the electricity usage.
5 dryers in a building of 8 units is a hell of a lot of dryers, what a waste of electricity when you could use a clothesline!