Assignment 3 – Unit 4
Zuhaib mahadi
Foul and Surface water drainage
Drainage systems inside buildings are made in order to remove foul and surface
water from toilet facilities and kitchen sinks. Rainwater is also removed through
drainage pipes which are located on the roof and carries rainwater through these
systems and drained into a local river. A modern-day drainage system must be
built according to the building regulations Approved Document H, the
requirements include:
• The falls required for drainage, so it flows directly
• Foul water drainage
• Rainwater drainage
• Building over drains
The image shows two different drainage systems, the combined drain system
carries the waste and surface run off in one pipe. In the separate drain system,
the waste and surface runoff are carried in different pipes.
,Combined Drainage
In a combined drainage system, a pipe is designed to carry both foul and surface
water. This system is the most cost effective and is easy to install. This type of
system works well in areas with low rainfall throughout the year.
Chudley. Building Construction Handbook.2019. Butterworth
Pearson. UK
In the image it shows the layout of a combined drainage system, the waste from
toilets, bathrooms, and kitchens inside the home is called domestic sewage. This
travels into the same system as rainfall from collected from storms that cause
surface runoff. The waste can be treated and put into the sea.
, The advantages of using a combined drainage system is that they can be easily
cleaned, and maintenance costs are very low, because combined drainage
systems are
Disadvantages of using a combined drainage system are that if the area were to
have a day of high rainfall, the area might flood and untreated waste might be
dumped in the sea, which causes environmental issues. Since the location of
development is in a area of high rainfall this wouldn’t be a good option.
Separate Drainage system
In a separate drainage system, the foul water and waste is carried separately to
be treated at a sewage treatment plant and rainwater is carried to a nearby river.
The advantage of having a separate system is that rainwater is not polluted
because it is in a separate pipe from foul water so it can be drained into a local
river. Less work is given to the treatment plant because rainwater is carried
separately it is not polluted. This also is good for the environment as less energy is
being used at the treatment plant. Rainwater can also be utilized in many ways
such as gardening, or washing your car.
There are multiple drawbacks of using a separate drainage system such as its
construction process which is bad because it can cause large amounts of noise
pollution in urban areas. Noise pollution has been said to cause high blood
pressure, stress and sleep disturbance and affects all age groups. Another
disadvantage of is that it can cause traffic congestions throughout the nearby
area, this might cause people to be late to work and which results in lower
productivity for companies on a bigger scale this will results in a loss of
