It’s easy to take drinking water for granted in the UK as it comesstraight out of our taps every day, and we expect it to be clean and safe. Buthave you ever thought ‘wheredoes tap water come from?’ The answer’s not as simple as you mightexpect. Our tap water has to go on a journey that may be well over a hundredmiles from our homes. It also undergoes a treatment process that makes it safeto drink. In this article we explain the whole process that brings you waterwhenever you turn on your tap.
Where exactlydoes tap water come from?
The water that comes out of our taps in the UK starts off as rain. That raineither flows into rivers and streams, is collected in reservoirs or is filteredunderground. The water companies in England, Wales and Scotland supply over16.5 billion litres of water a day to a population of over 65 million.
Surface water
Most of the UK’s tapwater comes from surface water. This is water from natural rivers andlakes as well as human-made reservoirs. Technically, surface water means anybody of water above ground.
There are currently 474 sources of surface water in England and Walesand 339 sources in Scotland. 64% of England’s drinking water comes from surfacewater, compared to nearly 93% of Wales’ water.
Groundwater
Groundwater is found in the fractures and spaces between geologicalformations of rocks, sand and soil underground. These formations are calledaquifers. Groundwater is stored in aquifers or moves slowly through them,thereby effectively filtering it.
There are currently 2,259 underground sources of tap water in Englandand Wales and 86 in Scotland. Although there are more underground sources inEngland and Wales, more of their tap water comes from surface water. 30% ofEngland’s tap watercomes from groundwater, compared to only 6% of Wales’ tap water.
Mixed sources
According to the latestreport from the Drinking water Inspectorate (DWI), 6% of England’sdrinking water (and just under 1% of Wales’) comes from ‘mixed sources’. TheDWI does not specify what these sources are.
Some countries recycle their wastewater. These‘toilet-to-tap’ solutions are seen as a solution to increased water shortages,where climate change adversely affects water treatment plants’ ability tocollect, reserve and recycle enough water for a growing population.
Thames Water are planning to implement a wastewaterrecycling scheme by 2025 , and the UK’s Environment Agency hassaid toiletwater could be pumped into rivers near treatment plants so it can be collectedand processed as drinking water by 2030.
However, we arealready effectively drinking recycled wastewater as water treatment plantsregularly flush diluted wastewater into our rivers when their systems cannotcope with large amounts of rainfall. The Environment Agency itself has said that water companies in Englandlegally dumped raw sewage into rivers over 400,000 times in 2020 as ‘a necessary part of the existingsewerage system’. In2022, the Environmental Audit Committee said untreated wastewater was regularlybeing illegally dumped .
Find out more about why water companies pumpsewage into our rivers and seas, here.
Why does tap water come from different sources?
Water is sourced differently depending on theparticular needs of the local area and the water resources available. If demandgoes up, the usual source of where water comes from might change to ensure water supplyremains constant. Having alternative sources means that water remains availableon tap in every home.
How does water get from source to tap?
Knowing wheretap water comes from is one thing, but knowing and understanding how itgets from source to tap is another question. Untreated water from rivers,lakes, reservoirs and underground sources is pumped to water treatment plantsaround the UK. Currently, there are 1297 different water treatment works acrossEngland, Wales and Scotland responsible for providing properties with drinkingwater. As the quality of the water they treat varies according to where they’vesourced it from, so their types of treatment will vary.
Removing large contaminants from water
Larger water treatment works will store water in reservoirs. This isso they have a larger supply of untreated water available if it doesn’t rainfor a long period. While all waterworks will screen collected water to removeitems such as branches and leaves, larger, heavier contaminants in untreatedwater will fall to the bottom of reservoirs, saving the need for treatmentplants to manually remove them. Some waterworks use a process calledflocculation. This is where a chemical coagulant is added to water which causessmall particles to bond together, making them easier to remove.
Water filtration processes
Smaller particles are removed by passing the water through a rapidgravity filter. This is a tank of coarse sand which traps some contaminants.Water is then filtered through large beds of fine sand. These slow sand filtersremove even smaller particles. Some treatment works create chemical reactionsin water to remove microscopic and dissolved particles, via processes such asozone, carbon and ion exchange.
Chlorination
The final treatment that drinking water undergoes before it’s pumpedto our properties is chlorination. Chlorine is added to the water to disinfectit of organisms and bacteria. This keeps the water safe from reinfection whileit’s stored in covered reservoirs before being sent through a network of pipesand pumping stations on its way to our taps.
Read more about the chlorinein our tap water, here.
Is tap water actually good for you?
Understanding ‘wheredoes tap water come from’ and the processes that go on behind gettingyour water from source to tap, will allow you to know whether it is safe todrink or not. The UK water authorities, on the whole, provide safe tap waterfor us all to drink. Drinking plenty of water is essential to maintaining ournatural levels of hydration. Around two thirds of our bodies are made up ofwater, so it makes sense that we should replace all the fluid we naturally losethroughout the day to stay in fit and healthy working order. When we get dehydrated,as well as feeling thirsty, we may start to feel tired, groggy, irritable andwe may experience headaches or a reduced ability to concentrate and focus.
Read more about the adverse effectsof dehydration.
How much should we drink and where shouldwe drink it from?
The UK government’s EatwellGuide suggests we drink around six to eight glasses of water a dayto maintain our body’s water balance. But some people can be put off by thetaste of their tap water. Knowing where your tap water comes from and the filter processing isvital to make a correct decision about how much you should be drinking, andwhere you should be drinking it from.
Those living near water treatment plants may have more chlorine intheir tap water than those who live further away, as chlorine evaporates aftera while. The DWIrecommends we filter our tap water ourselves to removethe chlorine.
The DWI also suggests we only drink freshly drawn water from the cold water tapdirectly off the water mains, usually the cold tap in our kitchen. They say notto drink or use the water from our bathroom taps for cooking as it usuallycomes from a storage tank in the loft so won’t be as fresh as from our kitchentap. But if you haven’t run any water for several hours, fill a washing up bowlbefore drinking any tap water. The DWI recommends that we don’t drink waterwhich may have been standing for a long time in our pipes.
If you’re concerned about your tap water, read moreabout the different contaminants here.
Why is tap water hard in some places?
Depending on where your tap water comes from, some peoplemay find that their water tastes slightly off and contains lots of tiny whiteflakes. This may be due to hard water. Hard water is when our water supply isdrawn from groundwaterthat’s been filtered through porous underground rocks like chalk and limestone,so there’ll be more minerals floating around in it. While water rich inmaterials can be healthy, limescale can form when calcium and magnesium bond.As well as affecting the taste of your water, this can cause significant damageto your home appliances.
Read more about hard waterand where it is mostly found in the UK
In this article we’vediscussed exactly wheretap water comes from in the UK and all the different types of treatmentit undergoes by the local water authorities to make it safe for us to drink.Drinking water is essential to our everyday health. If you don’t like the tasteor smell of your tap water, and you don’t like the presence of chlorine orlimescale, you can always purify your tap water yourself at home. The VirginPure Home Water System removes unwanted contaminants from your tapwater while leaving in the essential healthy minerals you’d expect to find inbottled water.
Find out about the benefitsof a home water purifier.
