Yes, it's safe for well-maintained septic systems. Chowsing Cat Litter is made from naturally Biodegradable soy with fast clumping making litter easy to scoop. This mulch able and flushable litter breaks down when immersed in liquid, so it's safe to flush, even with septic tanks. However, some customers like to compost it instead. One customer even said her grass is coming back! In order not to cause any possible damage to the septic tank，please remember *Flush only 1-2 clumps of Chowsing Tofu Cat Litter at a time in the toilet.