Starting with the least effective in terms of water-use reduction, the options are as follows:
How it works: Simply place a Save-a-Flush( sachet in the toilet cistern. The contents of the sachet will absorb water, thereby reducing the amount needed to refill the cistern.
Water saved: One litre with every flush.
Limitations: Although cheap, Save-a-Flush( saves much less water than some of the other options.
Cost: At just £1.41 per unit (or provided free by some water companies), possibly the cheapest water-saving device available.
Find out more: www.save-a-flush.co.uk
How it works: Like a bucket. As the cistern fills
up the Hippo, in effect a box open at the top, fills
with water. When you flush, the water stays in the
Hippo, reducing the amount being flushed away.
Water saved: Up to three litres with every flush.
Limitations: Hippos work better in older nine- to 12-litre cisterns, but can also be installed in toilets that have a lower flush volume.
Cost: A pack of Hippos should last a lifetime, and costs about £5.99. If they are working effectively, the payback period is estimated at eight to 12 weeks. After that they potentially offer a regular cost saving of up to £20 per year on metered water bills.
Find out more:
How it works: A kit that fits on top of your WC cistern and connects to the front-mounted flush handle. Only flushes when the handle is held down: releasing the handle stops the flush.
Water saved: You only use enough water to clear the toilet pan.
Limitations: Cannot be used on toilets with a valve flush.
Cost: Around £25.
Find out more: www.interflush.co.uk
COMPOSTING (OR DRY) TOILETS
How they work: By providing an enclosed environment for the natural process of aerobic decomposition. Contrary to popular belief, composting loos are no longer pits in the ground, and many
can be installed indoors in the bathroom like normal toilets. They can be extremely basic or state-of-the-art, depending on how much time and money you have. Over the last 40 years many different
composting loos have been developed, the most advanced featuring anything from fans to electronic controls. They also allow you to recycle your waste for use around the garden as plant fertiliser.
Water saved: They use little or no water and are not connected to sewerage systems.
Limitations: They are expensive compared to the simple devices mentioned above, but much cheaper than installing a whole new sewerage system and septic tank.
Cost: Around £1,000-plus.
Composting toilets typically fall into one of two systems:
A) Batch systems
Consist of between one and four containers, which are replaced on a rotational basis when full. After a full cycle is complete the first container is ready to be emptied and used as compost.
B) Continual process systems
Vary from basic two-chamber systems to full-flush systems that automatically deposit waste into a composting chamber. All are designed to be in a constant state of composting and provide
useable compost within six to 12 months.
Find out more: www.compostingtoilet.org
This article first appeared in the Ecologist April 2005
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