Is it Okay to Wash Acrylics Down the Drain?

One of my beginner students today asked me about the risks of washing paint down the drain:

It’s for all those reasons that I never wash acrylics down the sink!

If you have a greywater system, or treatment plant (bio system) it will clog the pump and you’ll have to replace it.

If you are on mains water, pouring acrylic (plastic) down a drain where it will end up in creeks and rivers and kill plants, fish, birds and animals is definitely not good!

At our studio we wash the brushes in a big bucket of water, then rinse in a second bucket. Then we tip the buckets out in our garden so the soil and gravel filters it and grabs it.

In our new classroom we’re building, we have designed a second set of sinks that don’t go down the drain, but instead go through a big (cleanable) pipe to a metre wide gravel pit we dug on our property. After 10 years when that pit fills with paint we’ll dig another pit, fill it with gravel, and move the pipe into it.

Not everyone has the opportunity to do this fancy solution. But if you paint in acrylics a lot, there’s another method.

I would find a big plastic water container with a little plastic tap on it. Sit it up on a shelf or table with a bucket below the tap.

Leave enough room above the bucket so you can wash brushes with brush soap under the running water.

You just need to keep refilling the top water reservoir when it empties.

When the slops bucket below is full, you can switch another bucket in. Let the full one sit undisturbed for a few weeks, so the paint settles to the bottom.

Then carefully tip the cleaner water off the top into the garden. The solid mass of thick paint at the bottom can go into the rubbish (perhaps a newspaper filled garbage bag). Then wipe out The bucket ready for the next swap over.