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.
Below is a table 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(Hardness is measured in mg/l and degrees Clarke)
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.
Hardness value table
| 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 |
Water hardness zones (Essex)
| Name | Zone Ref | Major towns | mg/l as Calcium (Ca) | mg/l as Calcium Carbonate (CaCO3) | Degrees Clarke | Description |
|---|---|---|---|---|---|---|
| range | range | range | ||||
| Basildon East | Z201 | Basildon/Pitsea | 110 - 140 | 275 - 350 | 19 - 24 | Hard/Very hard |
| Basildon West | Z202 | Basildon/Laindon | 100 - 130 | 250 - 325 | 17 - 23 | Hard/Very hard |
| Benfleet | Z203 | Benfleet/Canvey Island | 100 - 130 | 250 - 325 | 17 - 23 | Hard/Very hard |
| Billericay | Z204 | Billericay | 100 - 140 | 250 - 350 | 17 - 24 | Hard/Very hard |
| Brentwood | Z205 | Brentwood | 110 - 130 | 275 - 325 | 19 - 23 | Hard/Very hard |
| Chelmsford Central | Z206 | Chelmsford | 93 - 130 | 232 - 325 | 23 - 32 | Hard/Very hard |
| Chelmsford North | Z207 | Chelmsford | 100 - 130 | 250 - 325 | 17 - 23 | Hard/Very hard |
| Chelmsford South | Z208 | Chelmsford/Rettendon | 96 - 140 | 240 - 350 | 17 - 24 | Hard/Very hard |
| Criers Wood | Z209 | Witham | 97 - 140 | 242 - 350 | 17 - 24 | Hard/Very hard |
| Dengie | Z210 | Southminster/Burnham on Crouch | 100 - 130 | 250 - 325 | 17 - 23 | Hard |
| Grays | Z211 | Grays/South Ockendon | 100 - 130 | 250 - 325 | 17 - 23 | Hard/Very hard |
| Harold Hill | Z212 | Harold Hill | 100 - 130 | 250 - 325 | 17 - 23 | Hard/Very hard |
| Hockley | Z213 | Hockley | 100 - 120 | 250 - 300 | 17 - 21 | Hard |
| Hornchurch | Z214 | Hornchurch | 110 - 130 | 275 - 325 | 19 - 23 | Hard/Very hard |
| Hullbridge | Z215 | Hockley | 100 - 120 | 250 - 300 | 17 - 21 | Hard |
| Ilford | Z216 | Ilford | 100 - 130 | 250 - 325 | 17 - 23 | Hard/Very hard |
| Maldon | Z217 | Maldon | 100 - 120 | 250 - 300 | 17 - 21 | Hard/Very hard |
| Margaretting | Z218 | Margaretting/Ingatestone | 100 - 140 | 250 - 350 | 17 - 24 | Hard |
| Ockendon | Z219 | South Ockendon | 110 - 130 | 275 - 325 | 19 - 23 | Hard |
| Rayleigh | Z220 | Rayleigh | 100 - 130 | 250 - 325 | 17 - 23 | Hard |
| Rochford | Z221 | Rochford | 98 - 120 | 245 - 300 | 17 - 21 | Hard |
| Romford East | Z222 | Romford/Hornchurch | 100 - 140 | 250 - 350 | 17 - 24 | Hard/Very hard |
| Romford West | Z223 | Romford/Dagenham | 110 - 130 | 275 - 325 | 19 - 23 | Hard/Very hard |
| Seven Kings | Z224 | Ilford/Dagenham | 110 - 130 | 275 - 325 | 19 - 23 | Hard/Very hard |
| Silver End | Z225 | Silver End | 130 - 150 | 325 - 375 | 23 - 26 | Very hard |
| South Woodham | Z226 | South Woodham | 99 - 120 | 247 - 300 | 17 - 21 | Hard/Very hard |
| Southend East | Z227 | Southend | 99 - 120 | 247 - 300 | 17 - 21 | Hard/Very hard |
| Southend West | Z228 | Leigh on Sea/Westcliff | 100 - 120 | 250 - 300 | 17 - 21 | Hard |
| Stanford Le Hope | Z229 | Stanford Le Hope | 100 - 130 | 250 - 325 | 17 - 23 | Hard/Very hard |
| Thames | Z230 | Barking/Dagenham/ Rainham | 100 - 130 | 250 - 325 | 17 - 23 | Hard/Very hard |
| Tilbury | Z231 | Tilbury/Grays | 100 - 140 | 250 - 350 | 17 - 24 | Hard/Very hard |
| Upminster | Z232 | Upminster/Hornchurch | 110 - 130 | 275 - 325 | 19 - 23 | Hard/Very hard |
| Wickford | Z233 | Wickford | 110 - 130 | 275 - 325 | 19 - 23 | Hard/Very hard |
| Woodham Walter | Z234 | Maldon | 100 - 130 | 250 - 325 | 17 - 23 | Hard |
| Barkingside | Z235 | Barkingside/Ilford | 84 - 130 | 210 - 325 | 15 - 23 | Hard |
Water hardness zones (Suffolk)
| Name | Zone Ref | Major towns | mg/l as Calcium (Ca) | mg/l as Calcium Carbonate (CaCO3) | Degrees Clarke | Description |
|---|---|---|---|---|---|---|
| range | range | range | ||||
| Barsham | Z101 | Lowestoft/Beccles/Ilketshall | 140 - 190 | 350 - 474 | 24 - 33 | Very hard |
| Broome | Z102 | Bungay/Rumburgh/ South Elmham | 130 - 180 | 325 - 449 | 23 - 31 | Very hard |
| Coldfair Green | Z103 | Leiston/Aldeburgh/Knodishall | 170 - 190 | 424 - 474 | 30 - 33 | Very hard |
| Eye | Z104 | Eye | 160 - 190 | 400 - 474 | 28 - 33 | Very hard |
| Great Yarmouth | Z105 | Great Yarmouth/Gorleston/ Ormesby | 100 - 130 | 250 - 325 | 17 - 23 | Hard/Very hard |
| Hacheston | Z106 | Hacheston | 180 - 190 | 449 - 474 | 31 - 33 | Very hard |
| Halesworth | Z107 | Halesworth | 150 - 160 | 375 - 400 | 26 - 28 | Very hard |
| Lowestoft | Z108 | Lowestoft/Gorleston | 100 - 190 | 250 - 474 | 17 - 33 | Hard/Very hard |
| Parham | Z109 | Glenham/Hacheston/ Parham/Stratford St Andrew | 160 - 180 | 400 - 449 | 28 - 31 | Very hard |
| Redgrave | Z110 | Thorndon/Wortham/Palgrave/ Wetheringsett/Redgrave | 130 - 170 | 325 - 424 | 23 - 30 | Very hard |
| Rickinghall | Z111 | Mendlesham/Rickinghall/ Redgrave/Gislingham | 130 - 190 | 325 - 474 | 23 - 33 | Very hard |
| Saxmundham | Z112 | Saxmundham/Leiston | 170 - 190 | 424 - 474 | 30 - 33 | Very hard |
| Shadingfield | Z113 | Worlingham/Wrentham/ Kessingland/ Gisleham/Holton | 130 - 190 | 325 - 474 | 23 - 33 | Very hard |
| Southwold | Z114 | Southwold | 160 - 200 | 400 - 499 | 28 - 35 | Very hard |
| Syleham | Z115 | Stradbroke/Fressingfield/ Weybread/Wingfield/ Laxfield/Worlingworth | 160 - 180 | 400 - 449 | 28 - 31 | Very hard |
| Walpole | Z116 | Halesworth/Framlingham/ Yoxford/Rendham | 190 - 220 | 474 - 549 | 33 - 38 | Very hard |
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.