Page 258 - The City and Guilds Textbook: Plumbing Book 1 for the Level 3 Apprenticeship (9189), Level 2 Technical Certificate (8202) and Level 2 Diploma (6035)

The City & Guilds Textbook: Plumbing Book 1

Under the provisions laid down by the Water Act 2003, the UK Government
introduced two documents that regulate how plumbers install, commission and
maintain water supplies within domestic buildings. These are:
1 the Water Supply (Water Fittings) Regulations 1999
2 the Private Water Supplies Regulations 2016.

These will be discussed later in the chapter.

Sources of recycled, unwholesome water supply in
domestic dwellings
Over the past 20 years, demand for water has increased dramatically in the UK.
Each of us now uses an average of 150 litres of water every day for washing,
flushing the WC, drinking, cooking, gardening and other household tasks. With
the climate changing and frequent periods of drought becoming a possibility,
the need to save water is becoming more apparent.

There are many ways in which water usage can be reduced in a dwelling, from
simple rainwater collection in water butts for garden use, to more complex
systems for clothes washing and WC flushing. We will look at these here. It
must be remembered that this type of water is not fit for human consumption
and must be marked as such. Any installation in a dwelling must not
cross-connect with the mains cold water supply.

There are three types of unwholesome water:
1 grey water
2 rainwater harvesting
3 black water.

Grey water
Waste water from baths, showers, washing machines, dishwashers and sinks is
often referred to as grey water.
About a third of all water used in the average household is used for WC
flushing. The water used for bathing from baths, showers and washbasins can be
collected, cleaned and reused for this purpose.
Grey water is usually clean enough for use in WCs with only minimal
disinfection or micro-biological treatment. Problems can arise when the warm
grey water deteriorates when stored, as the bacteria it contains rapidly multiply,
making the water smell. This can be overcome by filtration and treatment with
chemicals. There must also be a means of protecting the mains water against
contamination by backflow from a grey water system, in order to comply with
the Water Supply (Water Fittings) Regulations 1999.

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