It's abit over the top. But, I'm in the business, and was responding to anincident one time. It was an urban creek and a sunny Saturday and there were three charity car washes on it, all draining to the same creek. The suds were about 4' high by the time the creek hit the chuck. Didn't matter as much in the 60s and 70s because all the creeks were dead anyways. But due to more concern by local people for the environment, the creeks are all supporting life again.
That said, the suds are probably more of an inconvenience for the life in the creek than anything. Same with latex paint (another recurring issue is people washing their paint supplies in the storm sewers and turning creeks the colour of milk).
Car wash business is easy enough to fix--just drain to a buffer area like grass or gravel and use easily biodegradable soap.