Water quality, hardness and compliance in Scotland
According to TapWater.uk's analysis, Scottish Water scores -1/10 for drinking water quality across 9 monitored postcode districts in 2026. The company reports 99.91% compliance with UK drinking water standards, and the average hardness across its monitored districts is 23 mg/L CaCO₃.
Scores sorted by lowest first — worst quality at the top.
| Postcode | Area | Score | Status |
|---|---|---|---|
| EH1 | City of Edinburgh | -1/10 | Very Poor |
| EH3 | City of Edinburgh | -1/10 | Very Poor |
| EH7 | City of Edinburgh | -1/10 | Very Poor |
| G1 | Glasgow City | -1/10 | Very Poor |
| G2 | Glasgow City | -1/10 | Very Poor |
| G3 | Glasgow City | -1/10 | Very Poor |
| G12 | Glasgow City | -1/10 | Very Poor |
| AB10 | Aberdeen City | -1/10 | Very Poor |
| AB11 | Aberdeen City | -1/10 | Very Poor |
Measured per district; 0% of monitored districts read hard or very hard, averaging 23 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.
99.91%
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 Scottish Water's supply differs from the national picture.
All postcode districts within Scottish Water's supply network.
Scottish Water's water meets legal standards, but the average score across 9 monitored districts is -1/10, with 0 contaminant readings flagged above recommended levels. Check your own district in the table on this page.
Across 9 monitored districts in Scottish Water's area, the average hardness is 23 mg/L CaCO₃ and 0% of districts read hard or very hard. Limescale pressure is moderate to low for most of this supply area.
Scottish Water reported a 99.91% 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.
Scottish Water supplies 5.4 million customers across Scotland. The postcode districts we monitor in its area: EH1, EH3, EH7, G1, G2, G3, G12, AB10, AB11.
Active incidents affecting Scottish 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 Scottish Water's own website, which carries the operational updates.