Do you worry about the taste or smell of your
drinking water?
Some people are very sensitive to smell and taste. If
you are, then you may notice smells or tastes in your
drinking water.
What if my water smells or tastes?
We would like to put your mind at ease. Drinking water
in Scotland is of a very high quality but you may sometimes
notice a slight taste or smell, particularly of chlorine.
If you do there is no cause to worry. BUT, if you notice a
particularly bad or strong smell or taste which means you
cannot drink the water, or you notice a smell or taste for
the first time, you should contact Scottish Water
immediately.
Enquiry and emergency numbers are listed under WATER in
your telephone directory.
Why does water smell or taste?
Any one of the following could cause people to notice a
slight smell or a taste or a change in the smell or taste
of their drinking water:
- The use of chlorine as a disinfectant
- Seasonal changes
- A change in your water supply
- Moving from one area to another
- Your plumbing
What is Chlorine?
Chlorine has to be used carefully, but it is harmless
when used in very small amounts as a disinfectant to treat
drinking water. It is also commonly used in various brands
of sterilisers for baby feeding bottles and equipment. It
is also used in higher concentrations to disinfect water in
swimming pools.
Why use chlorine?
It is absolutely essential that drinking water should be
safe to drink and contain no harmful bacteria capable of
causing diseases. Chlorine is a very effective
disinfectant. It has been used for 100 years. The addition
of chlorine in small amounts at water treatment works gives
maximum disinfection action before water reaches your
tap.
Why can I taste or smell chlorine in my water?
To be absolutely sure that disinfection is maintained
throughout the water mains, small amounts of chlorine are
allowed to stay in the water supplied to your tap. This may
result in an occasional slight smell of chlorine when you
turn your tap on or a slight taste of chlorine in the
water. A good, safe way to overcome this smell or taste is
to place a covered jug of water in the fridge before
drinking - cool water always tastes better, but throw away
any unused water after 24 hours.
Are these low amounts of residual chlorine
harmful?
No. The small amounts of chlorine in your water prevent
harmful bacteria growing in the water mains or your pipes.
You can rest assured that the usual amount of chlorine in
water leaving treatment works is safe and well within the
World Health Organisation guidelines.
What about seasonal changes?
Much of our drinking water is obtained by treating
waters taken from rivers and reservoirs. In summer, these
waters sometimes have a musty or earthy smell or taste
before they are treated. Treatment removes most of these
smells and tastes. But at times, especially during hot, dry
summer months, the drinking water may have a slight musty
or earthy smell or taste.
Are these smells or tastes harmful?
No. The slight smell or taste is harmless.
What if my water supply changes or if I move
house?
The content of water is complex and varies from area to
area, often because of the different rocks and soils
through which it passes. Treated waters from different
areas have different tastes. Hard water from a chalky area
will have a very different taste from soft water from a
reservoir in the hills. In some parts of the country,
Scottish Water can supply treated water from different
sources. If Scottish Water needs to change supplies, for
example because of increased use of water in the summer,
you may notice a change in the taste. Similarly, if you
move to another area you may notice that the water tastes
different.
What about lead?
Lead in the environment comes from a variety of sources
and may be present in air, food or water. Lead can have a
slight effect on the mental development of children and may
also be a factor in behavioural problems. In drinking water
it comes mostly from lead pipes that may be in people's
houses. Where necessary, Scottish Water treat water to
prevent it picking up lead from pipe work. New and more
stringent standards have been set for lead. An interim
standard has to be met by 31 December 2003, and a final
standard by 2013. Scottish Water are now working towards
meeting these tighter standards.
What about iron?
Iron can discolour water and this discolouration is
often a source of consumer complaints. Iron occurs
naturally in many water sources, but may also be derived
from the corrosion of iron mains. Any discolouration of
water by iron is unlikely to be harmful to health.
What causes discoloured water?
There are many possible causes, but the most usual
reason is the disturbance of any deposits present in the
water mains. This can happen when there is a change in the
direction or speed of flow of the water. Changes in flow
can occur for a number of reasons, for example, a burst on
a water main, the opening or closing of valves, bringing a
mains back in to use after repairs, Scottish Water having
to move water from one area to another to cope with changes
in demand and use of water for fire fighting. Very
occasionally it may be caused by the condition of your
service pipe connecting your house to the water main or the
condition of the internal plumbing within your house. These
problems can turn the water orange, brown or grey. It may
also be white as a result of chalk deposits or excess air.
White water caused by excess air clears from the bottom up
on standing freshly poured water in a glass and is not
something to worry about.
Why are there deposits in the mains?
There are two basic reasons.
- Many of the water mains in Scotland are cast iron.
The older ones are unlined and they have corroded,
especially in areas where the water is soft. The iron
corrosion particles (rust) become loose and can be
picked up by the water.
- In some areas, iron and manganese are present in
the source water. Inadequate treatment in the past may
have resulted in iron, manganese and other deposits
forming in the mains. Chalk can also be deposited in
the mains if softening plant is not working
effectively.
Are these deposits harmful?
If the water is discoloured you should not assume that
it is safe to drink until you have sought advice from
Scottish Water. If the discolouration is due to mains
deposits, these are mostly iron and manganese as such are
not likely to be harmful to your health. However you may
not wish to drink the water, or give it to your family,
because it looks or tastes unpleasant.
Is lead harmful?
Lead is commonly found in the environment. It comes from
a variety of sources including vehicle exhausts and old
paint work and may be present in air, food, soil or
water.
Lead can build up in the body and it can be harmful. It
is sensible to avoid excessive exposure from any
source.
The Government has taken action to reduce exposure to
lead from petrol, paint and drinking water.
Nevertheless some infants and children may still be at
risk. Studies have shown that lead can have a small effect
on the mental development of children. It may also be a
factor in behavioural problems.
It is best therefore to keep lead levels in water as low
as possible.
How does lead get into drinking water?
Water does not contain lead when it leaves the treatment
works.
For a long time, generally up to 1970, lead was used for
some water pipes. Part or all of the service pipe
connecting the water main in the street to your kitchen tap
may be made of lead.
Some types of water, particularly soft water from upland
areas, can pick up lead from pipes. Water is treated to
reduce this where needed. In addition, deposits containing
lead can build up in pipes and may occasionally be
dislodged.
For these reasons, the amount of lead in drinking water
can sometimes be above the standard.
How can I find out if there is lead in my
drinking water?
If your home has lead pipes, your drinking water may
sometimes contain high levels of lead. Scottish Water will
tell you how likely this is. It regularly takes samples of
the water supplied to individual properties in your area
and tests them for lead. It will take a sample from your
home if necessary, and will tell you the results.
What can I do to reduce lead levels?
If lead pipes are causing high lead levels in your
drinking water, you can take some simple short-term
precautions:
Do not drink water that has been standing in the pipes
for long periods, for example, overnight, or if no one has
been in for several hours.
In these circumstances, draw off a washing-up bowlful of
water from the kitchen tap to clear the water which has
been standing in the pipes. This need not be wasted but can
be used on the garden or for something other than drinking
or cooking. If the length of lead pipes exceeds 40 metres,
more than a bowlful of water will need to be drawn off.
You can then use the water from the kitchen tap as
usual.
If you have any lead pipework between the stop valve
outside your home and your kitchen tap,
the best solution is to replace it with
copper or plastic pipework.
If you do that, you can ask Scottish Water to replace
its part of the service pipe between the water main in the
street and the stop valve. It can be required to do this
free of charge.
Make sure that removing lead water pipes does not reduce
electrical safety by removing earthing. Ask your
electricity supplier if in doubt.
Where Can I Get Further Advice?
- From Scottish Water
- From your Local Authority Environmental Health
Officer
- From a Qualified Plumber such as one registered
with the Scotland and Northern Ireland Plumbers
Employers Federation (SNIPEF)