Waste handling for a urine-diverting toilet

In a urine-diverting dry toilet, urine and faeces are separated from each other to make waste handling easier, more hygienic and more odour-free. In the Separett Villa toilet, separation takes place directly in the seat, keeping the urine clean while only around 20% of the total waste ends up in the solid waste container.

Odours are prevented already through the separation process, and any odours from the waste container are led outdoors by the toilet’s internal fan. Separett Villa is a globally used and reliable urine-diverting dry toilet, with more than 125 000 installations in different types of locations.

Waste

In a urine-diverting toilet, waste is directed into separate containers and handled separately.

Faeces

Human faeces have a relatively low nutrient content, but may contain harmful bacteria. For this reason, clear regulations apply to the handling of faecal waste.

Handling faecal waste

There are two common and approved options for handling the waste collected in the rear container.

1. Changing the container, ageing and composting or burying in soil

1. Place the lid on the rear container and lift the container out of the toilet.
2. Leave the lid slightly ajar and add a thin layer of soil on top of the waste.
3. Store the container outdoors in a cool and shaded place for approximately 12 months.
4. During this time, soil bacteria and possible freezing reduce the amount of harmful bacteria.
5. After ageing, the waste can be composted or buried in soil in accordance with local regulations.

Please note that the bio bags are designed to withstand toilet conditions, so they may still be partially undecomposed after the ageing period.

2. Composting in a toilet waste composter

1. Lift the container out of the toilet and remove the bag.
2. Empty the contents of the bag into a toilet waste composter.
3. It can take up to 24 months for faecal waste to turn into soil.
4. According to Finnish regulations, toilet waste must age for at least 12 months before being buried in soil.

Urine

Separated urine is the most nutrient-rich waste produced by humans and contains especially nitrogen, phosphorus and potassium. Urine contains approximately 10% nitrogen (N), 1% phosphorus (P) and 2% potassium (K), making it a valuable natural fertiliser.

Using urine as fertiliser

Urine can be used as fertiliser for lawns, flower beds and most edible plants. During the growing season, however, urine is not recommended for direct use on lettuce or root vegetables that are eaten fresh.

Urine should be diluted with water before use. Diluted urine is safe and effective for plants, especially on nutrient-poor mineral soils. Fertilising is best done in the evening or when it is raining to minimise odour.

In winter, urine should be collected in a separate container and used as fertiliser in spring. Storage improves urine’s suitability as fertiliser.

Urine in greywater treatment

Separated urine can also be treated together with greywater. Since urine is nutrient-rich, this should be taken into account already when dimensioning the greywater system.

Regulations regarding the handling of toilet waste and urine vary between municipalities, so the guidelines and regulations of your own municipality should always be checked.