[Bionic]

I am trying my hand at dyeing for the first time.
I have 300 grams of wool in 3 hanks which have been mordanted with alum and cream of tartar and now I intend to dye them with madder extract. I will probably do it one at a time so that I get 3 variations of colour.
How do I dispose of the dye once I have finished?
With the mordant I never even gave it a thought and just tipped it down the drain (I have a septic tank).
thanks
Sally

[jaykay]

The things you are using aren't very toxic so the soil thing below is probably fine. If you ever used tin or chrome for a mordant, then the recycling centre is probably the way to go.

1. For toxic things - does your local tip/recycling centre have a bit for old paint cans? I think that would be the safest.

2. For less toxic things - you could dig a pit and tip it into the soil but you'll end up with a bit of soil that won't grow anything much and of course, it needs to be well away from any watercourse.

[Fleecewife]

As jaykay says.  I avoid tin and particularly chrome altogether - chrome makes for lovely clear colours, but at what expense to the environment (and the user too)?  Definitely not worth it.
If you use chemical acid dyes then the whole lot is taken up by the fibre (quite magically when you see the previously deeply coloured dye solution turn back to clear water  ) so any left over water can be tipped onto the soil in an out-of-the-way corner.
If you are going to do the digging a hole option, filling it with fine gravel helps, making a tiny soakaway.
For your alum mordant, try to use the right amount for the weight of wool/fabric, so there is a minimal amount left over.  The madder is fine so can be tipped anywhere, as can other dyestuffs from plants.
 
Don't forget to post us a pic of the finished item.  I love dyeing but for one reason and another I haven't done any for a couple of years.  It is such fun and so creative 

[Bionic]

Thanks both. I am really looking forward to getting some colour into my mordanted wool.  I would like the weather to improve a bit though so that I can hang it outside to dry.
Sally

[Fleecewife]

Most natural dyes degrade in sunlight, including madder - which is why 'redcoats' tended to become a bit pink, and Turkish rugs using natural dyes have pink instead of red after a while.  So best to dry it indoors - so no excuse not to get going 

[Bionic]

Yes, I am glad you put that little whistling emoticon on that one 
Actually if I wait for the sun I could well be waiting until next year
Sally