Is there a way to raise water level in w/c bowl . Regular plumber plumber we use at shop says no I say no knew supervisor's has his buddy in here doing work he is telling him to have me raise toilet bowl level because of problem we have, occasionlly when we dump from our waste treatment room (treated water from metal finish process) a few w/c get foam backed up in bowl or just bubbling, I believe there is obstuction in drain, prob after where toilets are tied in and with that in-rush of treated water it backs up in w/c bowl. His buddy supposably ran a snake in drain. I still believe obstuction

is there a way to raise water level in w/c bowl . Regular plumber plumber we use at shop says no I say no knew supervisor's has his buddy in here doing work he is telling him to have me raise toilet bowl level because of problem we have, occasionlly when we dump from our waste treatment room (treated water from metal finish process) a few w/c get foam backed up in bowl or just bubbling, I believe there is obstuction in drain, prob after where toilets are tied in and with that in-rush of treated water it backs up in w/c bowl. His buddy supposably ran a snake in drain. I still believe obstuction

The bowl level is controlled by the small tube that runs from the top of the ballcock to the white overflow tube, The higher the tank level the more water goes into the bowl. But that's not your problem. You already analized it yourself with
I believe there is obstuction in drain, prob after where toilets are tied in and with that in-rush of treated water it backs up in w/c bowl.
You were SPOT ON!! (Fire the plumber and take his place).
You have a partial blockage downstream from the toilet and unless the plumbers buddy pulled the toilet bowl and snaked from there or went up on the roof and snaked the lavatory roof vent he didn't snake jack!
You sound more qualified to do the job then either one of them so I'll give you the directions. As I stated, this can be snaked from either the toilet opening or the lavatory roof vent.
Rent a sewer machine, (see image) from your local Rent-All. If you don't wish to snake from the roof then pull the toilet and send 20 feet of cable down the opening. If you go up on the roof put out enough cable to reach the base and 20 feet more. Good luck, Tom

Thanks speedball1 for the reenforcement,checked all tanks, levels are 1/2"-1" below top of fill tube I believe that is proper adjustment


Sorry
"overflow tube"