Can you put eggshells in a septic system?

No you shouldn't put egg shells in quantity in your septic tank. I work for a plumber and we pump 20 tanks a day and you can actually see the eggs shells in the tank. They tend to make everything really hard and alot hatder to pump the tank, that in turn makes the cost to pump the tank a little higher. Some think that egg shells sharpen the blades on the disposal.While a disposal and a septic tank don't do to good together because for some reason the ground food doesn't break down it just sits on top. Try ice instead of egg shells in youe disposal. That will sharpen your blades {ever so slightly}/