Back in March I had a water report done through Brewuk and Murphy & Son's performed the water test.
The numbers I received back from my kitchen tap in south west London:
pH 7.19
Nitrate 33.50
Total Hardness (as CaCO3) 263
Calcium 93.08
Magnesium 93.08
Chloride 46.04
Sulphate 49.39...