How to dispose of urine from composting toilet

If you’ve recently purchased a composting toilet or are thinking of buying one, you will no doubt have several questions about waste management, how to handle it and what you can use it on and for. One question we get asked a lot is how to dispose of or how to use urine from a composting toilet.

Before we get into the uses and best practice of disposing of urine, it’s important to note there are various styles of composting toilets that deal with urine differently.

Most composting toilets will have urine going directly into the waste pile and the urine (along with moisture from solid waste) will be evaporated by an exhaust fan system that helps to reduce the overall amount of moisture in your composting toilet.

If you have a toilet with an exhaust fan set up, you won’t need to actually dispose of urine as the moisture will make its way back into the atmosphere by being evaporated. If however, you have a urine-diverting composting toilet, you will need to dispose of urine that’s caught in a separate container.

So, what’s actually in urine?

Like so many things in our current western, material world, we’ve somewhat lost touch with things that in the past, used to be recycled and used to benefit not only ourselves but the environment around us. Urine is a prime example of this.

For centuries, urine was utilised for a wide variety of uses from creating gunpowder and tanning animal hides through to making soap to whitening teeth (Ewww).

Whilst urine is made up mostly of water, it does have some interesting elements that can be utilised. Here’s what makes up urine most of the time:-

  • Urea
  • Chloride
  • Sodium
  • Potassium
  • Creatinine
  • Ammonia
  • Sulphate
  • Phosphate
  • Other compounds like proteins, hormones and metabolites

Ways to dispose of urine from your composting toilet

We all do it. Some of us sit, some of us stand but no matter who you are, where you’re from or the size of your bladder, we all need to wee.

Most of the country will pee in a flush toilet, which uses perfectly good drinking water to wash away urine into drains and pipes which then ends up at a processing plant. What many people don’t realise is that urine is an interesting chemical cocktail that can be utilised in many different ways.

#1 Just get rid of it

If you’re on the road using a composting toilet in your caravan or RV etc, it’s likely you’re probably wanting to simply dispose of any excess urine that’s been captured in your composting toilet. If you’re on the road you can simply dispose of urine in a public toilet or down a drain or sewer.

#2 Make a plant feed solution

If you look at the chemical makeup of fertilisers, you will notice that many of the compounds and ingredients in manufactured fertilisers are identical to those in urine. Fertiliser is mostly made up of Nitrogen, Phosphorus and Potassium (obviously with lots of different variations and chemicals depending on the producer and what it’s being made for).

Since urine closely resembles fertiliser in chemical makeup, you can actually make a plant feed solution which is particularly useful in the growth stage. Dilute one part urine to 10-15 parts water for plants in the ground and 30-50 parts water for pot plants as they’re usually a little more sensitive.

#3 Assist plants in their fruit-bearing stage

Plants that require lots of nitrogen like corn, squash, tomatoes, cucumbers, capsicum and beans during their fruit-bearing stage can be helped along with a dose of nitrogen from the above plant feed solution. It’s worth noting that there are dangers in applying too much so apply the solution intermittently and watch out for signs of excess nitrogen which includes curled leaves.

#4 Remedy nitrogen deficiencies in plants

If your plants have pale yellow or pale green leaves (when they should be vibrant and healthy) this can be a sign of nitrogen deficiency. Applying the plant feed solution listed above can help solve this problem.

#5 Use it as a compost additive

Because it’s so high in nitrogen, urine is a great addition to your garden compost pile. If you’re going to add it to your compost, you will also need to add carbon-rich materials like dry leaves, sawdust, straw, etc. In general, organic material that’s green and moist are high in nitrogen and those that are brown and dry are high in carbon. So if you’re going to add lawn clipping, spread them out first and let them dry before adding them, along with urine to your compost pile.

Above are five different ways you can use, reuse or dispose of urine from your composting toilet. The more we educate ourselves about ways to help our environment and recycle the things around us (including our own waste) the better the world will become!