at the hazmat locations they usually don't want anything mixed
they want everything labeled and separate ..
im glad i don' t live in CO the last thing i want in my rain is
nasty photochemistry ...

where i live things are quite strict, they don't want anything down the drain
photo chems are not the nicest things for the water, i don't blame the people
for not wanting to have it mixed in ...

if it was me, i'd just contact a waste hauler and have them deal with the stuff that isn't fixer.
i'd save my spent fixer and wash water
put the silver through a silver magnet to get the silver down to about 50, then with the wash water
into a trickle tank to get it below 5 and then into the 15 or 50 gallon drum for the waste hauler.
then when the magnet is full of silver i send it in to be refined, and i get a check for 800-900$
and it pays for everything, the magnet ( and its replacement cathode ) the trickle tank, and the waste hauler ..

that way there is a paper trail if the powers that be get nosey ...
and yes, that is exactly what i currently do, so if they want to get nosey i have records for the last 13 years that
say i did what was expected ..

good luck with your situation, i hope it gets easy for you, cause it sounds like a PITA ..


ps thanks matt !