Watermark your home.
We are building the longitudinal map of UK household water exposure, one home at a time.
WaterGraph is a family-owned UK water quality company. We test tap water in person, deliver a personalised report after every visit, and contribute the anonymised reading to a public picture of what is actually flowing through the country’s pipes. This page explains who we are, what we stand for, and where we are heading.
Why we exist.
Most people in the UK know that something is wrong with water. They have read about sewage in rivers, lead in old pipes, and water companies failing on compliance. What they do not have is a way to translate that abstract concern into the question that actually matters to them. What is in my water, and what does it mean for my family?
Water companies test at the treatment works, not at the tap. The Drinking Water Inspectorate confirms that the supply leaving the reservoir is compliant. By the time the water reaches your glass it has travelled through miles of shared mains, the local distribution pipes under your street, and your home’s own plumbing. Each of those layers can add lead, sediment, bacteria, or treatment chemicals that the reservoir test cannot see.
WaterGraph closes that gap. We come to your home, sample the water at your kitchen tap, and turn the readings into a clear personalised report. Then we do it again six months later. We give you a longitudinal picture rather than a snapshot, because water exposure changes with the seasons, with the weather, and with whatever is happening upstream of your house.
What “Watermark your home” actually means.
A Watermark is a £29 in-home water quality certification. Two visits, six months apart. Every visit is carried out in person by a trained WaterGraph engineer, often co-founder Hugh Fraser himself. We sample your kitchen tap on the spot, test nine specific drinking-water parameters, and deliver the results in plain English on the same day.
We chose two visits rather than one because a single reading is a snapshot. Water exposure varies through the year, and the picture you get from a single visit will not tell you whether something is stable, drifting, or seasonal. Six months apart gives us enough separation to see a trend without asking you to commit to anything longer.
We chose in-person rather than postal because an operator sees what a posted sample bottle cannot. The condition of your fittings, the smell at the tap, the presence of an unmaintained filter, the position of the cold-feed kitchen tap relative to the rising main. Postal kits collect water, but they miss the context that turns a reading into a useful report.
Family-owned, on purpose.
WaterGraph is run by Hugh Fraser and his father Benjie. Hugh runs operations and tests alongside our engineers most weeks. Benjie chairs the company and shapes the long-term direction. Between them they bring the operating discipline of two careers in finance and the patience that lets a small company build something properly rather than scaling something that does not yet work.
Every Watermark is delivered in person by a WaterGraph engineer, all trained in the same Cambridge-developed HWES methodology. The methodology itself is overseen by the Cambridge Lakehouse science team, so the readings stay rigorous as the engineering team grows. We have engineers available across the New Forest within 48 hours of booking.
We chose family ownership because the alternative shapes the product in ways we did not want. A venture-backed water company has to scale a postal kit, sell filters at the back end, or chase the next funding round before it has proven the science. We would rather stay small enough to keep the recommendations independent of what we sell, and let the geography deepen one watershed at a time.
Hugh Fraser
Co-Founder & CEO · Tests alongside our engineers
Benjie Fraser
Co-Founder & Chairman · Shapes the long-term direction
Cambridge methodology, independent governance.
The Home Water Exposure Score is owned by Dr Ralph St Clair Wade at the University of Cambridge. Ralph leads the methodology, the parameter weights, and the threshold logic that turn nine readings into a single zero to one hundred score. The methodology is versioned and reproducible from raw inputs. Research partnerships at Imperial College London add deeper expertise on hydrology and contaminant transport.
Academic governance is the reason WaterGraph readings can be referenced rather than just consumed. It is also why we describe ourselves as a Cambridge Lakehouse company. Meet the research team and read the full methodology story.
Three principles, applied without exception.
We do not sell filters.
WaterGraph makes money from tests and subscriptions. We take no commission, no affiliate revenue, and no sponsorship from filter brands, plumbing companies, or water-treatment retailers. When we recommend a product, the recommendation is independent. When we recommend doing nothing, the recommendation is just as independent.
We test in person.
An operator at your kitchen tap sees the whole picture. Fittings, sediment, smell, the layout of the cold feed, the state of any existing filter. A postal kit collects water but it does not see the context that turns a reading into a useful report. We test in person and we always will.
Your test builds the map.
Every household that joins makes the picture more complete. The anonymised readings combine into Area Water Exposure Scores that anyone can see for free on the WaterGraph Map. The more homes that test, the more accurately we can answer the question that every council, journalist, and insurer is starting to ask. What is actually in the water across this neighbourhood?
Seed-funded, grant-supported, New Forest-anchored.
Cambridge Lakehouse Ltd is a privately-held company incorporated on 1 October 2025. Companies House number 16305286. We are seed-funded, with research and pilot work supported by grant programmes across the UK water sector, including the Ofwat Water Discovery Challenge.
We are operating our Stage 1 pilot in the New Forest, where Hugh lives and where the combination of chalk geology, ageing rural infrastructure, and active community engagement makes for a representative test bed. Stage 2 expands across wider Hampshire from late 2026, then onwards by ecological similarity rather than arbitrary geography.
Talk to us.
For a Watermark booking, the fastest path is the calendar at the top of this page. For anything else, write to hugh@watergraph.co.uk or call +447786965763. Hugh answers both.
For privacy and data protection enquiries, the dedicated contact is on the privacy page.
Watermark your home.
£29 for two tests, six months apart. Personalised advice after each one. New Forest properties only.
Book Your Water Test · £29※ Pay only when you receive your results.
※ If your Watermark feels wrong, we’ll re-test for free.
↗ Or check your local water map