Diffusion systems/Dump Tanks/Emer Control Box

Hi All,
I'd like to know if anybody still has a diffusion system that dumps to the sewer?
Has it ever been used?
Do you have any headaches from the sanitation district?
If you have a dump tank has it ever been used?
We have systems that dump to a dry tank.
We have systems that dump to a wet tank.
We have systems that dump to the sewer.
None of them have ever been used (thank goodness) and I don't really see a reason why you would use one but the code(s) required them.
Currently we are battling with the sanitation district because they want the ones that connect to the sewer to be disconnected.
The City won't let us disconnect unless we upgrade to current code (but they are fine leaving them in place).
We don't want to spend money on something that has no pay back and provides no discernible increase in safety.
The sanitation district is demanding they be removed because they pose a safety hazard to their employees who might be working in a man-hole at the same time that we are forced to use the diffusion system. Even though it has never happened in fifty+ years (not just us but anybody that has a diffusion system).
Anyhow, I'd appreciate knowing if anybody has one or more elsewhere.

Thanks,

Peter

These systems stem from the San Francisco earthquake where manual relief valves could not be opened and systems failed. I have installed and worked on hundreds of these systems over the years. I tell all my clients they are a dumb idea, take at least 10 hours to dump the charge, stupid to dump to sewers, and they should rely upon the modern engineered relief valve systems they have installed. These are a holdover from another bygone era when they were a good idea.