Water quality
When the tap water looks or tastes wrong
Edinburgh tap water that turns brown, cloudy or tastes of chlorine is usually temporary and harmless, says Scottish Water, but small black specks in an older flat can point to lead pipes.
By the Pipes Up the Stair site team · how pages are checked · Updated
Scottish Water says sudden discolouration is normally only temporary. The trick is telling the harmless kind, such as air or a stirred-up main, from the one sign that deserves a closer look in an older flat: dark specks that may come from lead.
Everything below follows Scottish Water's own answers to these questions.
Why is the water brown or yellow?
Usually because something has disturbed the main. Scottish Water says sudden discolouration is often caused by mains work, a flow reversal or a burst, and that it is normally only temporary and will disappear after a short interval. Its discoloured water page adds that it is usually not harmful and can be cleared by running the first incoming cold tap, usually in the kitchen, at a trickle.
After supply work, Scottish Water says not to use the washing machine or dishwasher, or flush toilets, until the kitchen tap runs clear.
Why is it white or cloudy?
That's air. Scottish Water says milky water clears from the bottom of the glass upwards, is still safe to drink, and will generally improve within 24 hours. Pour a glass and watch: if it clears from the bottom up, it is air.
Why does it taste of chlorine?
Because chlorine is the usual disinfectant, and some homes are closer to where it's added. Scottish Water says you may notice it more near a new main, a service reservoir with secondary chlorination, or a treatment works. Some areas use chloramination instead. To soften the taste, it suggests filling a jug, covering it with a clean cloth and leaving it in the fridge for a couple of hours, then using it within 24 hours.
Why might it smell earthy or musty?
Scottish Water gives two causes: by-products of algae, and long lengths of pipework within large buildings. A tall tenement with old internal plumbing is exactly the kind of building where water sits in long pipe runs.
What do black specks in the water mean?
They can mean lead. Scottish Water says small dark grey or black particles can occasionally be caused by lead pipework, most likely in homes built before 1970. Don't ignore them: read lead pipes in Edinburgh, use the kitchen cold tap for drinking, and ask Scottish Water about a test.
Is Edinburgh's water hard or soft?
Scottish Water can tell you for your exact area. Its hardness factsheet says there is no regulatory limit for water hardness, that most Scottish water comes from surface sources and tends to be soft to slightly hard, and that it can give the hardness for any supply zone through its helpline. Its website also has a postcode water quality lookup.
The factsheet's bands, as calcium carbonate, are: soft under 50 mg/l, moderately soft 50 to 100, slightly hard 100 to 150, moderately hard 150 to 200, hard 200 to 300, and very hard over 300.
- under 50Soft
- 50 to 100Moderately soft
- 100 to 150Slightly hard
- 150 to 200Moderately hard
- 200 to 300Hard
Where does the water come from?
Some of it has a long history. Scottish Water says water from Talla Reservoir, completed in 1905, travels by aqueduct to Glencorse Water Treatment Works in Penicuik, completed in 2012.
| What you see | Usual cause | What to do |
|---|---|---|
| Brown or yellow | Mains work, flow reversal or a burst | Run the kitchen cold tap at a trickle |
| White or milky | Air | Leave a glass to stand; clears within 24 hours |
| Chlorine taste | Close to a new main, reservoir or works | Covered jug in the fridge |
| Earthy or musty | Algae, or long pipe runs | Ask Scottish Water if it persists |
| Black specks | Possibly lead pipework | Kitchen cold tap only; ask for a test |
24 hours
for cloudy water to generally clear
Source: Scottish Water
50 mg/l
upper limit of the soft band
Source: Scottish Water
Asked on the stair
Is cloudy water safe to drink?
Scottish Water says white or milky water caused by air is still safe to drink and generally improves within 24 hours.
Can you check water quality for your own street?
Scottish Water's website offers a postcode lookup for water quality in your area.
Should you run the water after coming back from holiday?
After water has stood, Scottish Water's lead advice is to run the kitchen cold tap until it feels colder before drinking it, which is a sensible habit in any older flat.
Does a water softener make sense in Edinburgh?
There is no legal limit on hardness, so it's a personal choice. Ask Scottish Water for your supply zone's hardness first.
Where this comes from
- Water quality FAQs — Scottish Water (archived copy of its page): discolouration, white water, chlorine
- Discoloured water FAQs — Scottish Water (archived copy of its page): clearing, black particles
- Taste and odour FAQs — Scottish Water (archived copy of its page): earthy and musty smells
- Water supply FAQs — Scottish Water (archived copy of its page): appliances after supply work
- Factsheet 12: water hardness — Scottish Water (archived copy of its page): no limit, bands
- Talla Reservoir at 120 — Scottish Water (archived copy of its page): Talla and Glencorse
- Water quality — Scottish Water (archived copy of its page): chlorine and chloramination