UK Water Quality Report • 2026 Data

Water Hardness in SO40

Water supply analysis across 7 postcode sectors in SO40 (Southern Water).

Outcode Avg Hardness280 PPMHard Water
Regional Quality Overview

Water Supply Analysis: Outcode SO40

For residents and businesses in outcode SO40, understanding local water chemistry is essential for appliance longevity and limescale prevention. Our environmental data shows that SO40 averages 280 PPM in mineral content, falling into the Hard Water classification.

Water chemistry can fluctuate across supply zones in SO40. The lowest mineral concentration is recorded in sector SO40 0 at 280 PPM, whereas sector SO40 9 experiences higher mineral levels reaching 280 PPM.

Due to the hard water (280 PPM) in SO40, 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 SO40

Lowest mineral concentration

Softest
Sector SO40 058 Postcodes • Hard
280 PPM19.6 °Clark

Hardest Sector in SO40

Highest mineral concentration

Highest Hardness
Sector SO40 9168 Postcodes • Hard
280 PPM19.6 °Clark

All Postcode Sectors in SO40

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