UK Water Quality Report • 2026 Data

Water Hardness in EN9

Water supply analysis across 3 postcode sectors in EN9 (Thames Water).

Outcode Avg Hardness280 PPMHard Water
Regional Quality Overview

Water Supply Analysis: Outcode EN9

Analyzing water quality disclosures across all 3 postcode sectors in outcode EN9 reveals an average water hardness of 280 PPM (Hard Water). Public water supply across this area is managed by Thames Water, responsible for treating and delivering water to residential households.

Water chemistry can fluctuate across supply zones in EN9. The lowest mineral concentration is recorded in sector EN9 1 at 275 PPM, whereas sector EN9 2 experiences higher mineral levels reaching 290 PPM.

Due to the hard water (280 PPM) in EN9, limescale build-up can occur on heating elements, shower heads, and boilers. Setting your dishwasher water softener to the correct level (e.g. Bosch setting H04) is strongly recommended to prevent cloudy glassware and internal scale accumulation. Review the individual postcode sectors below to get precise dishwasher salt settings and limescale recommendations.

Softest Sector in EN9

Lowest mineral concentration

Softest
Sector EN9 1243 Postcodes • Hard
275 PPM19.3 °Clark

Hardest Sector in EN9

Highest mineral concentration

Highest Hardness
Sector EN9 2172 Postcodes • Hard
290 PPM20.3 °Clark

All Postcode Sectors in EN9

Select a postcode sector below to view exact water softener salt settings, limescale protection guides, and appliance recommendations.