i have a local waste hauler set me up with a 3o gallon tank. all my chemicals go in there - developer, fix and fix remover. my wash water i save in a large bin, and send through a "trickle tank" which gets me to my legal limit here where i live which is 1 pt / million. he takes the tank 1ce or 2wice a year depending on how much i print, and i get a check for 30-40$ for the silver he gets processed so it costs me maybe 10-20$ a "haul".
i know lots of people dilute and dump ( actually lots of places suggest you just mix everything but the fixer together, so it neutralizes - since it is only the ph they worry about with non-fixer b&w photo-chemicals), but i'd rather my kids not play in a yard covered with develper/fixer &C, or have it end up in my vegtable garden, never mind my water supply.
good luck sorting through all this stuff, i am sure you will get a lot of different suggestions