Water quality, hardness and compliance in Cambridge
According to TapWater.uk's analysis, Cambridge Water scores 9.1/10 for drinking water quality across 4 monitored postcode districts in 2026. The company reports 99.96% compliance with UK drinking water standards, and the average hardness across its monitored districts is 330 mg/L CaCO₃.
9.1/10
Average score
Excellent
CB2
Lowest scored area
9/10
CB5
Highest scored area
9.1/10
4
Contaminants flagged
across all areas
Scores sorted by lowest first — worst quality at the top.
Measured per district; 100% of monitored districts read hard or very hard, averaging 330 mg/L CaCO₃.
Hard water is safe to drink but drives limescale in kettles, boilers, and appliances. Check your exact postcode or read our water softener guide if scale is a daily battle in your home.
Reported compliance with UK drinking water standards.
99.96%
Compliance above 99.9% is the norm across the UK industry, which is why a compliance figure alone says little about how your water actually tastes, scales, or reads locally. The per-district scores and flagged contaminants above are where Cambridge Water's supply differs from the national picture.
All postcode districts within Cambridge Water's supply network.
Yes. Across 4 monitored postcode districts, Cambridge Water's average water quality score is 9.1/10. The lowest-scoring district we monitor is CB2 (9/10) and the highest is CB5 (9.1/10).
Across 4 monitored districts in Cambridge Water's area, the average hardness is 330 mg/L CaCO₃ and 100% of districts read hard or very hard. Expect limescale: descaling, and in many homes a water softener, are worth considering.
Cambridge Water reported a 99.96% compliance rate against UK drinking water standards. Compliance above 99.9% is the industry norm, which is exactly why we also publish per-district environmental scores and flagged contaminant counts: legal compliance and local water character are different questions.
Cambridge Water supplies 0.35 million customers across Cambridge. The postcode districts we monitor in its area: CB2, CB3, CB4, CB5.
Active incidents affecting Cambridge Water appear at the top of this page as soon as our monitoring picks them up, alongside the affected postcodes. For supply emergencies always check Cambridge Water's own website, which carries the operational updates.