Water hardness

Why some water is hard

If your water comes from underground limestone or chalk rocks, or contains a proportion of groundwater, then the chances are that it is hard. The hardness is caused by the presence of minerals dissolved from the ground and rocks by the water.

If your water is hard you will notice that your kettle and other water heating appliances become furred up with a white scale. You may also find this scale in your bath, sink and shower. It isn't harmful but can be a bit of a nuisance. Hard water can also affect appliances like washing machines, dishwashers and steam irons. Please find below PDFs of water hardness for the Essex & Suffolk Water area, along with the measurement of hardness in degrees Clarke, for use with dishwashers and washing machines.

Water hardness by treatment area

This document gives you information on our water hardness broken down by zones, each zone takes its name from the major area supplied. Water hardness does not vary very much, it is relatively constant, the information below is from samples taken in  2010.

Hardness value table - (hardness is measured in mg/l and degrees Clarke)

Description	Clarke	Ca	CaCO3
Soft	0 to 3.5	up to 20	up to 50
Moderately soft	3.6 to 7	21 to 40	51 to 100
Medium / Slightly hard	7.1 to 10	41 to 60	101 to 150
Moderately hard	10.1 to 14	61 to 80	151 to 200
Hard	14.1 to 21	81 to 120	201 to 300
Very hard	over 21	over 120	over 300

Essex - water hardness zones

Document	PDF
Essex - water hardness zones

Suffolk - water hardness zones

Document	PDF
Suffolk - water hardness zones

One way of dealing with the problems caused by hard water is to consider fitting a water softener. There are various regulations concerning these, both their installation and use, so you must check with us if you are seriously considering a water softener and certainly before you buy one. 

Contact us to find out more or view our water quality webpage for further information.