What does it mean if the drinking water from your private supply looks, smells or tastes bad? These guidelines for drinking water quality will help you determine whether there’s an issue with your private water supply and how to get wholesome, great-tasting water.
Drinking water quality – an overview
In Scotland, our drinking water comes from rain – which we have in abundance!
Rainwater fills burns (streams), rivers, lochs and reservoirs. The water that cannot penetrate rock forms pools or groundwater.
Scotland’s groundwater is extremely pure because it has undergone a natural filtering process as rain seeps through the ground. These pools or groundwater provide a natural source of safe drinking water for all of Scotland and is the reason water quality standards are so high.
It makes you appreciate all that rainfall! In Scotland you’ll either be serviced from the mains supply by Scottish Water or have a private supply.
3% of households in Scotland use a private water supply. Many of these households are in rural areas like the Highlands & Islands and also include commercial premises like Airbnbs and hotels.
It’s the drinking water standards of private supplies that we’ll provide guidance on in this post.
Drinking Water Quality Regulator
The Drinking Water Quality Regulator (DWQR) was formed in Scotland in 2002.
It “exists to ensure that drinking water in Scotland is safe to drink” and works to standards set by the government. DWQR works closely with Citizens Advice Scotland to address consumers’ concerns about the taste and quality of their water.
Private water supplies are regulated by local authorities. However, the DWQR has a duty to oversee this process in the interest of public health. It also collects and interprets data on private supplies.
The DWQR no longer keeps a map of private supply locations as the accuracy of the data isn’t sufficient. However, all private supplies must be registered with the local authority.
The management of a private supply and drinking water safety is up to the person who owns it.
For guidance on what to do if you’re unhappy with the quality of your private drinking water please visit DWQR’s website.
The DWQR is a different organisation from the drinking water inspectorate in England and Wales.
Private Water Supplies in Scotland
If you’ve holidayed in rural Scotland you might have encountered a private supply. Over 200,000 people in Scotland drink from a private supply as part and parcel of everyday rural living.
Private water supplies (PWS) need careful management and can be categorised into two types:
- Larger PWS: for commercial activities
- Smaller PWS: for domestic properties
Different rules apply to commercial and domestic properties.
Water quality standards are generally high in Scotland. Yet the quality of a private supply can vary. If adequately treated and maintained, safe drinking water from a private source is possible.
However, drinking water safety can be seriously compromised with poor management of private supplies.
If you own or use a private supply it’s important to know the warning signs of contamination and the risks involved in drinking from a private source.
You might also be bound by law to test your water quality if you operate a commercial property. This includes holiday homes and Airbnbs.
You can find more information about private water supplies and water quality compliance at the Scottish Government website.
How often should private water supplies be tested?
You must test your water quality annually if you:
- supply 50 or more people, or more than 10m3 of water a day
- form part of a commercial or public activity
- are used in a commercial or public activity (for example at village halls, in restaurants and hotels, or on campsites)
Under the Scottish Government’s new regulations, privately rented properties, Airbnbs and holiday lets are considered commercial premises.
If the local council deems a water source unpredictable they might test as often as every 3 months. The more people a private supply serves the more frequently it needs to be tested.
A local water company or your council can help you create a water management plan to keep you supply free from contamination.
Homeowners are under no legal obligation to test their private supply, although they do have a duty of care to those using their private supply.
What does it mean if my drinking water looks dirty or discoloured?
Discoloured, dirty looking water could be caused by contamination from:
- corroded pipework leaving iron deposits in water
- naturally occurring magnese
If you suspect corroded pipes are to blame you should replace old lead pipes with safer, modern pipework. Don’t forget to check the condition of your storage tank too. You can obtain a grant of up to £800 from the Scottish Government.
It’s important to upgrade lead pipes due to serious health impacts from heavy metals, particularly in young children and babies. Our blog on lead pipe health risks details the acceptable amount of lead in water and when to take action.
Manganese is naturally occurring mineral found in some parts of Scotland. It can cause dark brown discolourations in drinking water. Scottish Water are held accountable by the DWQR for removing manganese from the public supply.
In some parts of Scotland, manganese is naturally present in the supply and if it is not removed by the treatment process it can cause black or dark brown discolouration to supplies. DWQR expects Scottish Water to work to ensure all supplies at risk from manganese have adequate treatment to remove it.
For owners of a private supply, try running your taps and flushing toilets. Wait an hour then check if the water colour has cleared. It’s still black or dark brown, contact your local council or water hygiene company immediately.
If you’ve moved to rural Scotland from a city or big town, you might notice changes to the quality of your water.
Contaminants like soil or algae can enter your supply after heavy rainfall. Both these substances can contain bugs that are harmful to humans. The environmental protection
agency tries to keep Scotland’s water healthy, however water needs to be treated for public health. In the case of a private supply, you’ll need to organise treatment techniques yourself.
What about cloudy water?
Cloudy water isn’t normally a cause for concern. Fill a glass of water from the tap and wait for the water to settle. If the bottom of the glass clears first then the cloudiness is simply a result of trapped air bubbles.
Is discoloured water dangerous to drink?
In mains water supplies, discoloured drinking water usually poses an aesthetic issue rather than a health concern.
For private supplies that aren’t regularly treated and monitored by Scottish Water, its essential that you get your water checked. Any unusual tastes or smells, or a sudden change in water appearance should be immediately checked.
Why does my water taste and smell bad?
Water with an unpleasant taste or odour isn’t normal and should be investigated for potential contaminants.
Disinfection byproducts, like chlorine, are a generally harmless part of water treatment.
Tap water that tastes like petrol or smells like gas or turpentine is cause for concern. A leaky underground storage tank may be at fault, in which case stop using your supply immediately and contact your local water company.
Other unpleasant tastes and smells in water can include fish, mould and a sulphuric smell akin to rotten eggs.
Hydrogen sulfide is usually the culprit if your water tastes or smells like sulphur. Drains, water heaters, wells and pipes can harbour bacteria which, when broken down, release hydrogen sulfide.
Sometimes the element in your water heater is corroded, which can cause a rotten egg smell when you run the tap. Contact a plumber to fix this issue.
Decaying organic matter in water system or water sources can cause a mouldy or fishy smell. Try cleaning the drain of matter to see if the problems clears up. If the unplesant smell or taste persist then the issue could be your water source, in which case it’s best to hire a professional to check your water supply.
Salty water is usually harmless. It could be that you live in an area with naturally high levels of sodium, magnesium or potassium in the water.
How to fix unpleasant tastes, odours and appearance of drinking water
If you decide to keep using your supply while it’s being tested always boil the water before using it. However, is recommended to use bottled water until you receive your test results.
Your local authority or private water company can help test your water.
Here’s a handy list of contact details for all council authorities in Scotland:
- Glasgow City
- City of Edinburgh
- North Lanarkshire
- South Lanarkshire
- Aberdeenshire Council
- Aberdeen City
- West Lothian City
- Falkirk Council
- Perth & Kinross Council
- Dumfries & Galloway
- Dundee City Council
- North Ayrshire
- East Ayrshire
- Scottish Borders
- South Ayrshire
- East Dumbartonshire
- East Lothian
- East Renfrewshire
- West Dunbartonshire
- Argyll & Bute
- Na h-Eileanan Siar (Western Isles)
Alternatively, you can contact a local water hygiene company to test your water.
An added benefit of choosing a private water company that they can perform a water risk assessment to check for Legionella, E.coli and other harmful bacteria that may be contaminating your supply. They’ll also be able to offer ongoing support.
PHX Water we help consumers with regular maintenance plans to ensure their business is legally compliant. Consumers receive a regular report on their water health and are billed in one simple, affordable monthly package. For full contact details visit our contact page.
Because drinking water quality in Scotland is high it’s often taken for granted. Don’t gamble with your health or anyone else’s. Get your private water supply checked at the first sign of unpleasant tastes, colours or odours.