UK Tapwater Quality Map

What is the map for?
The UK Tapwater Quality Map is designed to show fishkeepers what the water is like in their local area. Aquarium test kits only give a rough indication of certain parameters, while others such as chlorine and chloramine levels, aren't easily measured. It's of use in selecting the appropriate products for treating tapwater (standard dechlorinators don't work properly on dechloraminated water) and in determining whether you need to purify the water before use.

Where does the data come from?
The data plotted on the UK Tapwater Quality Map is contributed by readers of Practical Fishkeeping using the freely available Schedule Four Drinking Water Quality Reports, which are available from your local water authority.

How accurate are these data?
The water test results in the Schedule Four Drinking Water Quality Reports need to be very accurate to meet the standards set by the Drinking Water Inspectorate. However, the results shown are the averages taken over a number of samples, consequently some values may be slightly higher or lower than those shown at certain times.

What reports have you plotted so far?
So far we have mapped 99 zone-specific Water Quality Reports from readers in 44 counties across the United Kingdom:

Aberdeenshire
Whitehillocks
Mannofield East
Fraserburgh

Anglesey
North Anglesey

Bedfordshire
Ampthill

Buckinghamshire
Milton Keynes City South East

Cambridgeshire
Peterborough City West
Peterborough Stanground
March
Cambridge North
Coton
Cambridge South
Heydon
Linton
Croydon
Ely

Ceredigion
Aberystwyth
Llechryd

Conwy
Llandudno and Colwyn
Dolwyddelan
Llyn Conwy
Capel Curig

County Down
Lisbane, Northern Ireland

Cumbria
Castle Carrock
Barrow Town
Ennerdale South

Denbighshire
Prestatyn
Abergele and Rhyl
Denbigh

Derbyshire
Chesterfield and Dronfield
Oakwood and Chaddesden

Devon
Plymouth City One

Dunbartonshire
Milngavie

Essex
Harold Hill
Southend West
Maldon

Flintshire
Connahs Quay
Holywell and Mold

Gwynedd
Bangor and Caenarfon
Nant Peris
Lleyn
Bala
Dolgellau
Cilfor
Brycrug
Llwyngwril
Blaenau Ffestiniog
Pennal and Corris
Abergynolwen

Hampshire
Rownhams
Overton

Hertfordshire
Bushey/Borehamwood

Kent
Bough Beech
Dry Hill

Lanarkshire
Daer-Camps

Lancashire
Worsthorne Burnley

Leicestershire
Leicester City Centre and North Evington

Lincolnshire
Boston
Market Deeping

London
Wanstead
South Tottenham

Merseyside
Maghull
Southport North

Mid Glamorgan
Bryncoch

Middlesex
Uxbridge/Heathrow
Uxbridge/Heathrow

Norfolk
Kings Lynn
Heigham

North Yorkshire
Skipton - Craven
Scarborough

Northamptonshire
Northampton West

Northumberland
Bishop Auckland

Nottinghamshire
North City, Redhill and Basford
West Bridgford, Meadows and Rylands

Oxfordshire
Thame

Somerset
Maundown East

South Yorkshire
Sheffield - Loxley

Staffordshire
Butterhill

Suffolk
Ipswich South
Newmarket

Surrey
Alderstead
Burgh Heath
Caterham
Dorking
Warlingham
Tillingdown
Outwood
Surrey Hill
West Surbiton
Godalming

Tyne and Wear
Middlesborough Central
Warkworth

West Lothian
Balmore F, Livingston

West Midlands
Northfield - South Birmingham
Stonleigh, Kirby and Stivicall
Kingstanding

West Yorkshire
Leeds LL Bramhope/Holbeck
Leeds South Middleton Fanley

Wiltshire
Allington

Worcestershire
Sheriffs Lench

Who has provided reports so far?
We are very grateful to the following PFK readers for taking the time to send us their Water Quality Reports:

• Jeremy Gay
• Matt Clarke
• Paul Cole
• Alex Stewart
• Rupert Collins
• May Brown
• Craig Mason
• Paul Tagg
• Stuart Halliday
• David Webb
• Dave Bates
• Gavin Campbell
• Debi Roe
• Colin Dunlop
• Keith Llewellyn
• Stuart Morse
• Paul Rowntree
• Adrian Ellingford
• Keith Jackson
• Chris Lock
• John Dixon
• Ian Corbett
• M Burningham
• Clair Read
• Norman Kelsey
• Phillip Allen
• Dr Martin Griffiths
• David Priestley
• Eddie Richardson
• Dr Stuart Findlow
• Lawrie Milne
• Julie Marland
• Bobby Palmer
• Steve Bent
• Paul Seels
• Niall Canavan
• Julia Todd
• Cathie Jenkins
• Andrew Masson
• Peter Bradley
• Mats Petersson
• Helen Ablitt
• Kedar Pithwa

My tests show that the pH of my tapwater is 7.9, but the map says 7.56. Which is correct?
There are two things to remember here. Firstly, the results displayed on the map are the mean results for the hundreds of tests taken each year by the water authority. They might have measured pH levels ranging from 7.2 to 8.4, but the average for the year was 7.56.

Secondly, aquarium test kits are far from reliable for anything other than a basic indication of the water chemistry. Our in-depth laboratory comparisons of phosphate, nitrite and nitrate test kits have shown that aquarium kits often give misleading or inaccurate results. By contrast, the water authority use much more sophisticated analytical methods for testing.

How can I tell if there's chloramine in my water?
At the current time the water authorities do not need to state on these reports whether the water is dosed with chloramine. Where this information has been available it has been added. You can get an indication of the quantity of chloramine in the water by subtracting the level of free chlorine from the level of total chlorine.

How much chlorine should there be?
There's no legal limit or recommended level for chlorine at the moment.

My nitrate looks high.
The water authority is supposed to provide water with a nitrate level of less than 50 mg/l. I've yet to see an authority who has breached this limit, although the water in some parts of Cambridgeshire at 40-45 mg/l comes fairly close. If you have a high nitrate level consider purchasing a nitrate removing tapwater purifier or an RO unit. It wouldn't be advisable to use water this polluted with sensitive fishes or marines.

What about phosphates?
The Schedule Four reports don't typically contain data on the levels of phosphorous in tapwater so we have not been able to plot this data.

Why do lots of areas seem to have water with a high pH but a very low hardness?
It appears that some water authorities may be manipulating the natural pH of their water to make it less acidic, while not adjusting the hardness. Parts of Scotland in particular often have water of a high pH (8.3-8.5) but a very low hardness of just 2-3 °GH. Such water has a low buffering capacity and the pH of the water is liable to plummet in the aquarium. The standard is to keep the water at a pH level of 6.5 - 9.5.

How do I get the report?
You may be able to obtain the report from your local water authority website, alternatively, you can obtain it by writing to, emailing or calling them. It is very important that you tell the authority (and us) the postcode that the report is for as these reports are specific to small areas of a water authority's catchment.

I've been sent a glossy-looking annual report. Is this the one you need?
Probably not. The annual report does not include individual test results. We need the results of the lab tests that are specific to your postcode or water supply zone. This is normally called a Schedule Four report, although some authorities have a different name for it. If you ask to speak to someone in the technical department and explain your needs they will be able to send the right one.

Where should I send the report?
Please email the report PDF or link to matt.clarke@emap.com, or post it to: UK Tapwater Quality Map, Practical Fishkeeping, Bretton Court, Bretton, Peterborough, PE3 8DZ. You'll get an acknowledgement on the map and the details page for providing the data.