Water companies test the grid. We test at your tap.
WaterGraph is an independent water testing service for UK homes. Our postal lab tests show you what's in your tap water, with a Water Health Score and a personalised Care Plan that explains what to do about it.
Nothing over UK health limits. No readings need attention.
Your tap's water on 3 September 2026. Nothing to watch closely, and some wellness factors to know.
Home monitored
Guard
Your next kit posts in March. We are watching your water network and will email you the moment anything changes.
Your water, on one page
Every test ends in a report built around your home: what we found at your tap, what it means, and what to do about it.
Every reading, explainedHow to fix issues, in orderYour home, monitored
WaterGraph was built with researchers at Imperial College London.
We don’t sell water filters, and any recommendations we make are independent.
How it works
1
Order a test · Fill two bottles · Post them back
Your kit arrives in one working day with a returnable prepaid box. Simply fill the bottles with the first water out of your tap and post it back free of charge.
2
Results in 3 working days
A plain English verdict and Care Plan, guiding you through what to fix and how to fix it.
3
Guard keeps watch
A second test in six months, and we send you alerts if your area has unsafe water network issues.
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Our customers
Know what your children are drinking
We check what matters most to them – lead from old pipes, nitrates, too much copper or iron – and tell you plainly if anything needs fixing, and how to fix it.
David, 38 years old, London
“I’d never thought about it until now… they’re always drinking from the kitchen tap, and before you guys I had no idea what was coming out of it… especially for the baby’s bottle.”
8 parameters tested Every reading in plain English.
A personal Care Plan Exactly how to improve your water’s health, based on what you’re interested in, and what not to waste money on.
Water working for your body
Hardness, copper, iron, and pH all shape how water reacts with your skin, hair and gut.
Sarah, 29 years old, London
“Before I got the right filter, the only relief for my skin and hair was going to another country! Never knew that knowing what was in the water could help me make the right decision to get my confidence back.”
Your actual tap Results for what’s really coming out of it, not the area average, and your options to alleviate any issues.
The right filter Find out what makes sense for you, or if yours is working as intended.
Your missing health metric
You track your sleep, exercise, and diet. But the two litres you drink every day have never been tracked – no longer.
Kate, 44 years old, Hampshire
“I want to live a healthy and mobile life until I’m 95. I’ve started tracking my key metrics, but this was totally missing.”
Water Health Score One 0–100 number, built from 8 key indicators.
More than one tap Test several taps in one order, and watch the numbers move as you fix things.
WaterGraph is a water screening service. We work hard to provide accurate results that help you make informed decisions about your health and wellness.
We regularly perform control tests to ensure that our accuracy remains high. Our processes have been built with researchers at Imperial College London. We don’t certify water as safe for drinking, and we don’t offer a UKAS-accredited laboratory service.
How we recommend solutions and calculate the Water Health Score
The foundation of our company is to provide you with the truth. Your Care Plan is built on your readings and the evidence for what works, and nothing else decides what goes in it.
These recommendations are based on your test results, personal wellness goals, the proven efficacy of available solutions (free and paid), customer service ratings of paid solutions, cost, and effort.
Our team
Prof Adrian ButlerAdvisorProfessor of Subsurface Hydrology, Imperial College London
Professor of Subsurface Hydrology at Imperial College London, specialising in subsurface water flow and contaminant transport – including the Chalk aquifers of Southern England. He works closely with the British Geological Survey and is Principal Investigator on the NERC-funded CAMELLIA project.
Dr Tom RowanAdvisorAssistant Professor, Imperial College London
Nearly seven years advancing simulation tools and field instrumentation for water systems, combining low-cost sensor design with AI to tackle pollution and water security. His early-warning sensor research was highlighted by the American Geophysical Union. PhD in Fluid Mechanics at Durham, with postdoctoral research at Durham and Imperial.
Dr Ralph St Clair WadeCOO & Chief Research Officer
Leads on research and operations at WaterGraph’s parent, Cambridge Lakehouse. Formerly Managing Partner of CambridgeCultura, a Cambridge research and insights spinout accredited by the Crown Commercial Service, and a Cambridge-funded visiting specialist at UNESCO. He took the top result in his year at St John’s College, Cambridge, where he held two doctoral scholarships. He is an Affiliated Lecturer at the University of Cambridge.
WaterGraph is an independent water testing service for UK homes. Our postal lab tests show you what's in your tap water, with a Water Health Score and a personalised Care Plan that explains what to do about it. We test your sample in our lab in London.
How much does WaterGraph cost?
WaterGraph Test is £49. WaterGraph Guard is £59 a year for two tests six months apart, plus alerts all year. WaterGraph Premium is £399 and adds a lab test for PFAS (forever chemicals), then renews as Guard at £59 a year.
David, 38 years old, London
Sarah, 29 years old, London
Kate, 44 years old, Hampshire
