UK Water Quality Report • 2026 Data

Water Hardness in CR9

Water supply analysis across 10 postcode sectors in CR9 (Thames Water).

Outcode Avg Hardness275 PPMHard Water
Regional Quality Overview

Water Supply Analysis: Outcode CR9

Looking for water hardness metrics in CR9? Water supplied by Thames Water in this outcode registers a baseline average of 275 PPM across 10 distinct postcode sectors.

Water chemistry can fluctuate across supply zones in CR9. The lowest mineral concentration is recorded in sector CR9 0 at 275 PPM, whereas sector CR9 9 experiences higher mineral levels reaching 275 PPM.

Due to the hard water (275 PPM) in CR9, 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 CR9

Lowest mineral concentration

Softest
Sector CR9 04 Postcodes • Hard
275 PPM19.3 °Clark

Hardest Sector in CR9

Highest mineral concentration

Highest Hardness
Sector CR9 91 Postcodes • Hard
275 PPM19.3 °Clark

All Postcode Sectors in CR9

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