The Privy 500 by Separett is a great place to start if you’re looking to build your own low-cost urine-separating, waterless compost toilet.
The Separett Privy 500 is a waterless, urine-separating seat/bowl that enables you to construct a composting toilet to suit your individual needs, situation and budget.
The Separett Privy 500 comprises the following:
- A urine-separating bowl, made from polypropylene – easy to clean and durable
- 2.5 metre urine hose – reinforced
- An insulated seat, made from cellular plastic – warm in winter!
- A seat lid with hole to attach string so it doesn’t blow-away or get lost
The main cause of odours in compost toilets is the mixing of liquids and solids, which creates a slurry. Copious amount of cover/soak material, such as sawdust can help alleviate this, but you end up with very large compost heaps due to the quantity of materials being generated, plus the need to empty the container on a regular basis. By separating liquids from solids and dealing with each separately, you have a) a much more manageable solution and b) much less odour.
The Separett Privy 500 is a urine-separating design, so by keeping solids ‘dry’ and either adding a cover material or by venting the area, odours will be reduced to a minimum and the solids container will need emptying much less frequently (every 3-6 weeks as opposed to every 3-5 days), making management much easier.
Better design than other plastic separators?
The Privy 500 has been developed in Sweden after many years research into urine-separating designs. With experience borrowed from the Villa series, the Privy 500 is a simple and elegant design that simply works. Little touches like a baffle on the urine exit stops items dropping down the pipe, and the drip ring around the solids opening means if someone has an accident, urine will not run down the underside of the separator and create a nasty smell (and a nasty clean up job too). Unlike other ‘cheap’ plastic separators on the market, it’s not brittle and the top fitting, all-round design makes for a neater finished product.
Your personal design
To construct your toilet using the Privy 500, you’ll need to consider the following: 1) where will the urine go?, and 2) how will you control odours?
Urine – this can be captured in a suitable container and disposed of (in an appropriate place) when full. Using a container is particularly appropriate for people on boats etc. The easiest way of dealing with urine is to dig a soakaway pit and run the urine directly into it (where it will slowly dissipate into the ground). The final option is ideal if you have existing waste/drain pipes for sinks etc. – simply connect the urine pipe into your existing grey water drains.
Odour control – there are broadly 2 ways to deal with odours. The first is to smother ‘solids’ using a ‘cover material’, the most effective being sawdust or fine wood shavings (often sold as pet bedding). This acts as a barrier over the solids and will stop smells leaking out, additionally, it holds air in the solids bucket which will promote subsequent aerobic composting. To use, simply put a handful of sawdust/shavings over your ‘deposit’! The other way is to actively remove the smells using a small fan (such as a 12 volt computer fan). This, when properly placed, will draw air over the solids and ‘suck’ the odours through the fan, where it can vented outside.
The best way for you will depend on your situation, resources, money and expectations. Cover materials tend to be cheap (sometimes free), although they add an extra stage in using the toilet and will add bulk to the solids container, meaning you’ll need a larger compost bin. Using a fan means people don’t have to do anything else, but it will mean having some power available (perhaps 12v from a solar panel/battery), so it’s more complicated to install in the first instance.
Once you’ve decided on the best way of dealing with urine and odours, you’ll need to think about constructing a base for the Privy 500, which will also need to include some form of ‘solids’ bucket/container.
Specifications for the Separett Privy 500
Bowl: Polypropylene, recyclable.
Seat: Recyclable cellular plastic
Hose: 2.5 metres, 32mm diameter (ribbed exterior for strength and durability)
Weight: 1.25kg approx.