My taken is the system is dead. The ammonia has killed everything and quants should not be allowed to be used and they would need a special permission from any city to use them. The city would not allow them to be discharged in the sewer system and they would be required to have a holding tank. A pumper will probably not pump the system either as he will have no place to dump the load and if he tries could get in a lot of trouble. If he is successful and they monitor what is going in he will definitely tell them where they got it from and you will have the state or local government bodies at the facility they vane from shutting it down and issuing fines. If the pumper discharges and it gets into the city plant it will ruin the process and they will investigate everyone who dumped force the parties pay for the damage or sue for it. Unless it’s a small town even then they would flip out. Someone did something similar here and Texas wildlife got involved do to the discharge going into a water way, Texas rangers got involved it wasn’t good. We have a population of 7000 and they lost it over someone dumping a hot load.