I am not sure what you mean with “new ones” and if you mean re-using the same fresh fruit or changing the type of offering. the most important thing if you work with Egeria intensely is to always have fresh water: do NOT let the water go stale for days because she gets quite offended by that. I think offering a fresh fruit every day is a bit over the top, so what I would do is make sure to change the water every day (you can use the old water for the plants it tends to be very good for them) and then offer a fruit once a week or so. Don’t offer up the same fruit again and again.
As per disposal: the idea would be to leave them by a crossroad and/or into the woods or a park and/or by a river. Showing them into the trash should really be a last resort but in case you need to do that, make sure to say a simple formula like “Egeria and all the spirits that are nourished through you, you have taken what you needed from this offering and now I am disposing of its material remains”. I know that going to a park can be a hassle but if you don’t have to do it every day it should be more feasible.