Proper disposal or replenishment of gold toner

I'v exhausted my first batch of Bostick and Sullivan's gold toner. Is it safe to toss it down the drain or store it for proper disposal? Or can I just replenish it like selenium toner?

I'm a newbie myself but found this:
(there was a url link here which no longer exists)
RalphLambrecht: I use one 5-gallon container for all exhausted darkroom chemicals, which I take to haz waste when full.THey never coomplainned or even questioned me but ,I always have to watch to get my container back.

Thanks tnp651. I just bought The Book of Alternative Photographic Processes By Christopher James. The book says I could replenish it by adding 50ml of .2% gold chloride and 50 ml of .2% ammonium thiocyanate per used liter of exhausted gold toner. He also recommends filtering the used solution with a coffee filter to strain out particulates. I've replenished selenium toner and it works well.