Name: Susanne
Message: Hi Paula, Thanks for all the information on your site. Do you know if fiber reactive dye is bad for a septic system?

I have heard from dye artists who use quite a lot of fiber reactive dye and yet have had no difficulties with their septic systems, even after many years of dyeing. I believe that that the dye itself is not a problem for the septic system. (The situation may be different with large scale industrial use; I am referring to home use by professional hand dyers.)

Far more harmful to the septic system is any strong acid or base. It would be wise to be careful to neutralize any large quantities of soda ash solutions with an acid such as vinegar, before pouring them down the drain. Use pH paper to judge when you have added a sufficient quantity of acid to neutralize the base; you want a pH near 7 (where 1 is a very strong acid, and 14 is a very strong base). One source of pH paper is Dharma Trading Company.

It is also possible that large amounts of salt could cause problems to the septic system, but the amounts of salt added to water by a water softener are probably more significant, and it is common to use a water softening system in combination with aseptic system.