According to TapWater.uk's analysis, Portsmouth scores 8.5/10 for drinking water quality in 2026. Water is supplied by Portsmouth Water and has been tested for 21 contaminants across 6 postcode districts.
8.5 / 10
6 areas tested · 4 flagged · UK average 9.0
Yes, Portsmouth tap water is safe to drink. Based on 6 areas tested, Portsmouth has an average water quality score of 8.5/10 (below the UK average of 9.0/10). 4 contaminants were flagged above recommended levels across all areas. Water is supplied by Portsmouth Water. Portsmouth Water draws from chalk springs and boreholes in the Hampshire Downs, one of the UK's smallest water companies.
Contaminants flagged most often across the city.
All postcode districts in Portsmouth, ranked by water quality score.
Main water supplier: Portsmouth Water (6 postcodes)
None of the 4 rivers and waters that Portsmouth drains into is rated good by the Environment Agency. All of them fail the chemical test, as every river in England does, because of long-lasting pollutants such as mercury and PFOS. This describes the rivers, not your tap water.
| River or water | Ecological health | Postcode districts |
|---|---|---|
| Portsmouth Harbour | Moderate | PO1, PO2 |
| Solent | Moderate | PO4, PO5 |
| Langstone Harbour | Moderate | PO3 |
| Potwell Trib | Moderate | PO6 |
Environment Agency classification, 2025. River health across England
Taste, chlorine and hardness bother people even where the water passes its tests. These are the three fixes our readers pick most: a jug for drinking water, a shower filter, and a reverse osmosis unit that needs no plumbing. Check your own postcode above to see which one your water needs.
The jug for cleaner drinking water
ZeroWater 12-Cup Ready-Pour
Jug Filter · NSF/ANSI 53, NSF/ANSI 401
Typical price
£40approx.
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For dry skin and hair after a shower
Jolie Filtered Showerhead
Shower Filter
Typical price
£85approx.
Affiliate link: we may earn a commission at no extra cost to you.
Reverse osmosis without a plumber
Osmio Zero 2.0 Countertop RO
Reverse Osmosis
Typical price
£495approx.
Affiliate link: we may earn a commission at no extra cost to you.
Affiliate link: we may earn a commission at no extra cost to you. How recommendations are funded
Yes, Portsmouth tap water is generally safe to drink. Across 6 areas tested, the average water quality score is 8.5/10. Portsmouth Water draws from chalk springs and boreholes in the Hampshire Downs, one of the UK's smallest water companies.
Yes, you can drink tap water in Portsmouth. It is regulated to UK drinking water standards, and across 6 tested areas the average water quality score is 8.5/10. Enter your postcode for the readings in your exact area.
The most commonly flagged contaminants across Portsmouth are Nitrite (flagged in 4 areas). No PFAS were detected.
Hardness data is not yet available for Portsmouth. Enter your postcode for detailed water quality data.
The areas with the best water quality in Portsmouth are PO2 (8.7/10), PO6 (8.5/10), PO1 (8.4/10).
Water in Portsmouth is supplied by Portsmouth Water. Portsmouth Water draws from chalk springs and boreholes in the Hampshire Downs, one of the UK's smallest water companies.
No PFAS (forever chemicals) have been detected in any of the 6 areas tested in Portsmouth.
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<script src="https://www.tapwater.uk/widget.js" async></script>Get a detailed water quality report for your exact area in Portsmouth.
Based on water quality data from 6 postcode districts in Portsmouth. Data from your water company via the Stream Water Data Portal and the Environment Agency. See our methodology for how scores are calculated.