Tap water quality in Oxford
Oxford has hard water (258 mg/L CaCO₃), and all tested parameters are within UK drinking water limits.
Supplied by Thames Water · Oxford Central · Based on DWI laboratory analysis
Nitrates
21.40mg/L
Chlorine
0.55mg/L
Lead
1.30µg/L
Fluoride
0.12mg/L
Water hardness
258 mg/L CaCO₃
Hard
Your area has hard water. This can affect skin conditions and cause limescale buildup.
All tested parameters are within safe drinking water limits
For the analytes shown, reported values are within UK drinking water standards. This does not replace your supplier's formal water quality report.
How readings compare to limits
Nitrates
21.40 mg/L
PCV / limit: 50 mg/L
Chlorine
0.55 mg/L
No UK limit · WHO guideline 5 mg/L
Fluoride
0.12 mg/L
PCV / limit: 1.5 mg/L
Lead
1.30 µg/L
PCV / limit: 10 µg/L
Hardness (as CaCO₃)
258 mg/L CaCO₃
Hard
What these readings mean
UK drinking water is regulated under the Water Supply (Water Quality) Regulations 2016, which set a prescribed concentration value (PCV) for each substance. Thames Water must sample against these and report the results to the Drinking Water Inspectorate.
Nitrates in Oxford
21.40 mg/L·UK limit 50 mg/L
Nitrates come mainly from agricultural fertiliser and sewage reaching groundwater. Healthy adults process them without difficulty; the limit exists principally to protect bottle-fed infants under six months.
Lead in Oxford
1.30 µg/L·UK limit 10 µg/L
Water leaves the treatment works lead-free. Any lead is picked up from the pipework between the main and your tap, so the reading depends heavily on your own property — pre-1970 homes are the ones worth checking.
Fluoride in Oxford
0.12 mg/L·UK limit 1.5 mg/L
Occurs naturally in some groundwater and is deliberately added in a minority of UK supply areas. Around 10% of England receives a fluoridated supply.
Chlorine in Oxford
0.55 mg/L·UK limit no statutory limit
Added as a disinfectant and required to remain present through the network to keep water safe in transit. Typically 0.2–0.5 mg/L at the tap. A noticeable taste is usually harmless and fades if water stands in a covered jug.
Living with hard water in Oxford
At 258 mg/L CaCO₃, Oxford sits firmly in the hard water band. Hardness is dissolved calcium and magnesium picked up as water passes through chalk and limestone. It is not a health risk — the minerals are the same ones found in food — but it has practical consequences.
- Limescale. Kettles, showerheads and heating elements scale up faster. Descaling every few months keeps appliances efficient.
- Skin. Some people with eczema find hard water aggravates symptoms, though the evidence on softeners as a treatment is mixed rather than settled.
- Soap and detergent. Hard water needs more of both to lather, which is why dishwasher salt exists.
Common questions about Oxford tap water
Is Oxford tap water safe to drink?
Yes. Oxford tap water is supplied by Thames Water and every parameter we hold (nitrates 21.40 mg/L, lead 1.30 µg/L, fluoride 0.12 mg/L and chlorine 0.55 mg/L) falls within UK drinking water standards set by the Drinking Water Inspectorate. Readings vary by supply zone, so check your exact postcode for local results.
Is Oxford hard or soft water?
Oxford has hard water. Lab results put hardness at 258 mg/L CaCO₃, which is classed as hard on the UK scale.
What is the water hardness in Oxford?
Water hardness in Oxford is hard (258 mg/L CaCO₃). Above roughly 200 mg/L you can expect limescale in kettles and appliances, and some people find hard water aggravates dry skin.
Who supplies the tap water in Oxford?
Tap water in Oxford is supplied by Thames Water. They are responsible for treatment, distribution and the laboratory testing reported to the Drinking Water Inspectorate.
Sewage spills in Oxford
Official Environment Agency storm overflow data near the town centre.
Check your postcode
Look up any UK address for lab results and nearby overflows.