Water Hardness in London

Greater London, London • 171 postcode districts

Hard

The average water hardness in London is 277 ppm, classified as hard. London is served by Thames Water and Severn Trent Water and Affinity Water and Yorkshire Water, covering 171 postcode districts across Greater London in the London region.

Hardness varies across the area — see the table below for a breakdown by postcode district.

Water Hardness by Postcode in London

Postcode	Water Company	Hardness	PPM	Level
E7	Thames Water	350 ppm	350 ppm	Very Hard
E6	Thames Water	349 ppm	349 ppm	Very Hard
E5	Thames Water	348 ppm	348 ppm	Very Hard
E4	Thames Water	347 ppm	347 ppm	Very Hard
E3	Thames Water	346 ppm	346 ppm	Very Hard
N9	Thames Water	346 ppm	346 ppm	Very Hard
E2	Thames Water	345 ppm	345 ppm	Very Hard
N8	Thames Water	345 ppm	345 ppm	Very Hard
E1	Thames Water	344 ppm	344 ppm	Very Hard
N7	Thames Water	344 ppm	344 ppm	Very Hard
N6	Thames Water	343 ppm	343 ppm	Very Hard
N5	Thames Water	342 ppm	342 ppm	Very Hard
N4	Thames Water	341 ppm	341 ppm	Very Hard
N3	Thames Water	340 ppm	340 ppm	Very Hard
W9	Thames Water	340 ppm	340 ppm	Very Hard
N2	Thames Water	339 ppm	339 ppm	Very Hard
W8	Thames Water	339 ppm	339 ppm	Very Hard
N1	Thames Water	338 ppm	338 ppm	Very Hard
W7	Thames Water	338 ppm	338 ppm	Very Hard
W6	Thames Water	337 ppm	337 ppm	Very Hard
W5	Thames Water	336 ppm	336 ppm	Very Hard
W4	Thames Water	335 ppm	335 ppm	Very Hard
W3	Thames Water	334 ppm	334 ppm	Very Hard
W2	Thames Water	333 ppm	333 ppm	Very Hard
SE9	Thames Water	327 ppm	327 ppm	Very Hard
SE28	Thames Water	326 ppm	326 ppm	Very Hard
SE8	Thames Water	326 ppm	326 ppm	Very Hard
SW20	Thames Water	326 ppm	326 ppm	Very Hard
SE27	Thames Water	325 ppm	325 ppm	Very Hard
SE7	Thames Water	325 ppm	325 ppm	Very Hard
NW9	Thames Water	324 ppm	324 ppm	Very Hard
SE26	Thames Water	324 ppm	324 ppm	Very Hard
SE6	Thames Water	324 ppm	324 ppm	Very Hard
NW8	Thames Water	323 ppm	323 ppm	Very Hard
SE25	Thames Water	323 ppm	323 ppm	Very Hard
SE5	Thames Water	323 ppm	323 ppm	Very Hard
NW7	Thames Water	322 ppm	322 ppm	Very Hard
SE24	Thames Water	322 ppm	322 ppm	Very Hard
SE4	Thames Water	322 ppm	322 ppm	Very Hard
NW6	Thames Water	321 ppm	321 ppm	Very Hard
SE23	Thames Water	321 ppm	321 ppm	Very Hard
SE3	Thames Water	321 ppm	321 ppm	Very Hard
NW5	Thames Water	320 ppm	320 ppm	Very Hard
SE2	Thames Water	320 ppm	320 ppm	Very Hard
SE22	Thames Water	320 ppm	320 ppm	Very Hard
NW4	Thames Water	319 ppm	319 ppm	Very Hard
SE1	Thames Water	319 ppm	319 ppm	Very Hard
SE21	Thames Water	319 ppm	319 ppm	Very Hard
NW3	Thames Water	318 ppm	318 ppm	Very Hard
SE20	Thames Water	318 ppm	318 ppm	Very Hard
NW2	Thames Water	317 ppm	317 ppm	Very Hard
NW1	Thames Water	316 ppm	316 ppm	Very Hard
SW9	Thames Water	315 ppm	315 ppm	Very Hard
SW8	Thames Water	314 ppm	314 ppm	Very Hard
SW7	Thames Water	313 ppm	313 ppm	Very Hard
SW6	Thames Water	312 ppm	312 ppm	Very Hard
SW5	Thames Water	311 ppm	311 ppm	Very Hard
SW4	Thames Water	310 ppm	310 ppm	Very Hard
SW3	Thames Water	309 ppm	309 ppm	Very Hard
N22	Thames Water	308 ppm	308 ppm	Very Hard
SW2	Thames Water	308 ppm	308 ppm	Very Hard
N21	Thames Water	307 ppm	307 ppm	Very Hard
N20	Thames Water	306 ppm	306 ppm	Very Hard
E20	Thames Water	302 ppm	302 ppm	Very Hard
SW19	Thames Water	302 ppm	302 ppm	Very Hard
SW18	Thames Water	301 ppm	301 ppm	Very Hard
SW17	Thames Water	300 ppm	300 ppm	Hard
EC1R	Severn Trent Water	299 ppm	299 ppm	Hard
SW16	Thames Water	299 ppm	299 ppm	Hard
W1H	Severn Trent Water	299 ppm	299 ppm	Hard
SW15	Thames Water	298 ppm	298 ppm	Hard
W1G	Severn Trent Water	298 ppm	298 ppm	Hard
WC2B	Severn Trent Water	298 ppm	298 ppm	Hard
SW14	Thames Water	297 ppm	297 ppm	Hard
W1F	Yorkshire Water	297 ppm	297 ppm	Hard
WC2A	Severn Trent Water	297 ppm	297 ppm	Hard
SW13	Thames Water	296 ppm	296 ppm	Hard
W1C	Thames Water	296 ppm	296 ppm	Hard
EC1N	Severn Trent Water	295 ppm	295 ppm	Hard
SW12	Thames Water	295 ppm	295 ppm	Hard
EC1M	Severn Trent Water	294 ppm	294 ppm	Hard
SE19	Thames Water	294 ppm	294 ppm	Hard
SW11	Thames Water	294 ppm	294 ppm	Hard
SE18	Thames Water	293 ppm	293 ppm	Hard
SW10	Thames Water	293 ppm	293 ppm	Hard
W1B	Severn Trent Water	293 ppm	293 ppm	Hard
SE17	Thames Water	292 ppm	292 ppm	Hard
SE16	Thames Water	291 ppm	291 ppm	Hard
SE15	Thames Water	290 ppm	290 ppm	Hard
SE14	Thames Water	289 ppm	289 ppm	Hard
NW11	Thames Water	288 ppm	288 ppm	Hard
SE13	Thames Water	288 ppm	288 ppm	Hard
NW10	Thames Water	287 ppm	287 ppm	Hard
SE12	Thames Water	287 ppm	287 ppm	Hard
WC1X	Severn Trent Water	287 ppm	287 ppm	Hard
SE11	Thames Water	286 ppm	286 ppm	Hard
SE10	Thames Water	285 ppm	285 ppm	Hard
WC1V	Severn Trent Water	285 ppm	285 ppm	Hard
EC1A	Severn Trent Water	282 ppm	282 ppm	Hard
N19	Thames Water	282 ppm	282 ppm	Hard
N18	Thames Water	281 ppm	281 ppm	Hard
W14	Thames Water	281 ppm	281 ppm	Hard
WC1R	Severn Trent Water	281 ppm	281 ppm	Hard
N17	Thames Water	280 ppm	280 ppm	Hard
W13	Thames Water	280 ppm	280 ppm	Hard
N16	Thames Water	279 ppm	279 ppm	Hard
W12	Thames Water	279 ppm	279 ppm	Hard
N15	Thames Water	278 ppm	278 ppm	Hard
W11	Thames Water	278 ppm	278 ppm	Hard
E18	Thames Water	277 ppm	277 ppm	Hard
N14	Thames Water	277 ppm	277 ppm	Hard
W10	Thames Water	277 ppm	277 ppm	Hard
WC1N	Severn Trent Water	277 ppm	277 ppm	Hard
E17	Thames Water	276 ppm	276 ppm	Hard
N13	Thames Water	276 ppm	276 ppm	Hard
E16	Thames Water	275 ppm	275 ppm	Hard
N12	Thames Water	275 ppm	275 ppm	Hard
E15	Thames Water	274 ppm	274 ppm	Hard
N11	Thames Water	274 ppm	274 ppm	Hard
E14	Thames Water	273 ppm	273 ppm	Hard
N10	Thames Water	273 ppm	273 ppm	Hard
E13	Thames Water	272 ppm	272 ppm	Hard
E12	Thames Water	271 ppm	271 ppm	Hard
WC1H	Severn Trent Water	271 ppm	271 ppm	Hard
E11	Thames Water	270 ppm	270 ppm	Hard
E10	Thames Water	269 ppm	269 ppm	Hard
W1D	Affinity Water	269 ppm	269 ppm	Hard
WC1E	Severn Trent Water	268 ppm	268 ppm	Hard
WC1B	Severn Trent Water	265 ppm	265 ppm	Hard
WC1A	Severn Trent Water	264 ppm	264 ppm	Hard
EC4Y	Severn Trent Water	254 ppm	254 ppm	Hard
E9	Thames Water	251 ppm	251 ppm	Hard
EC4V	Severn Trent Water	251 ppm	251 ppm	Hard
E8	Thames Water	250 ppm	250 ppm	Hard
EC4R	Severn Trent Water	247 ppm	247 ppm	Hard
EC4N	Severn Trent Water	243 ppm	243 ppm	Hard
EC4M	Severn Trent Water	242 ppm	242 ppm	Hard
EC4A	Severn Trent Water	230 ppm	230 ppm	Hard
EC3V	Severn Trent Water	218 ppm	218 ppm	Hard
EC3R	Severn Trent Water	214 ppm	214 ppm	Hard
EC3N	Severn Trent Water	210 ppm	210 ppm	Hard
EC3M	Severn Trent Water	209 ppm	209 ppm	Hard
EC3A	Severn Trent Water	197 ppm	197 ppm	Hard
E1W	Severn Trent Water	191 ppm	191 ppm	Hard
EC2Y	Severn Trent Water	188 ppm	188 ppm	Hard
EC2V	Severn Trent Water	185 ppm	185 ppm	Hard
EC2R	Severn Trent Water	181 ppm	181 ppm	Hard
EC2N	Severn Trent Water	177 ppm	177 ppm	Moderately Hard
SW1Y	Severn Trent Water	177 ppm	177 ppm	Moderately Hard
EC2M	Severn Trent Water	176 ppm	176 ppm	Moderately Hard
SW1X	Severn Trent Water	176 ppm	176 ppm	Moderately Hard
SW1W	Severn Trent Water	175 ppm	175 ppm	Moderately Hard
SW1V	Severn Trent Water	174 ppm	174 ppm	Moderately Hard
SW1P	Severn Trent Water	168 ppm	168 ppm	Moderately Hard
EC2A	Severn Trent Water	164 ppm	164 ppm	Moderately Hard
W1W	Severn Trent Water	163 ppm	163 ppm	Moderately Hard
WC2R	Severn Trent Water	163 ppm	163 ppm	Moderately Hard
W1U	Severn Trent Water	161 ppm	161 ppm	Moderately Hard
SW1H	Severn Trent Water	160 ppm	160 ppm	Moderately Hard
W1T	Severn Trent Water	160 ppm	160 ppm	Moderately Hard
W1S	Severn Trent Water	159 ppm	159 ppm	Moderately Hard
WC2N	Severn Trent Water	159 ppm	159 ppm	Moderately Hard
N1C	Severn Trent Water	157 ppm	157 ppm	Moderately Hard
SW1E	Severn Trent Water	157 ppm	157 ppm	Moderately Hard
EC1Y	Severn Trent Water	155 ppm	155 ppm	Moderately Hard
SW1A	Severn Trent Water	153 ppm	153 ppm	Moderately Hard
WC2H	Severn Trent Water	153 ppm	153 ppm	Moderately Hard
EC1V	Severn Trent Water	152 ppm	152 ppm	Moderately Hard
W1K	Severn Trent Water	151 ppm	151 ppm	Moderately Hard
W1J	Severn Trent Water	150 ppm	150 ppm	Moderately Hard
WC2E	Severn Trent Water	150 ppm	150 ppm	Moderately Hard

Water Companies Serving London

Thames Water

Average hardness: 302 ppm (Very Hard) • 354 postcodes served

Severn Trent Water

Average hardness: 221 ppm (Hard) • 401 postcodes served

Affinity Water

Average hardness: 268 ppm (Hard) • 33 postcodes served

Yorkshire Water

Average hardness: 215 ppm (Hard) • 218 postcodes served

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