Looks like they are using to much detergent and using the water lance at a very high pressure, which can also damage vehicles
Planning permission for a car wash has been granted on that land, if their operating their business with significant disregard to the PP. The council should act.
The detergents/cleaning agents being used need to be suitable for discharge to the sewerage system, Often they are sold in containers with just some codes. So hard to tell.
I am sure they have a trade effluent consent agreement with the sewerage undertaker its a legal document.
It's mentioned the tarmac surface is delaminating, the problem there is debris will be washed into the drainage system but should not be a problem if the correct silt trap/intersceptor is fitted.
Hope you get it sorted out, good luck
