Originally Posted by Wheatfield 
For a small user, there isn't going to be enough silver in the waste to be an issue. If you have an automatic dishwasher you are dumping far worse things than a little bit of silver sulphate down the drain.
It's not just the silver, of which there isn't much. DON'T dump chemicals down the drain. You could leave the container open, evaporate the water then dispose of the crystals that are left in the garbage. Better still, have a lab do those 2 lousy rolls.