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Regulator record

CO11 tap water: what's in it?

Affinity Water: at least 20 tests failed UK drinking-water standards in 2025 (DWI, company-wide).

Some published DWI figures don't reconcile or identify a company, so we've left them out; the true number may be higher. England overall: 99.97% of tests met standards.

CO11 tap water quality report · 2026

  • Hardness

    Very hard

    Details

    Underground 2 Zone (supply zone) · read on 28 September 2026

  • Hosepipe ban

    In force in part of Affinity Water's area

    Details

    A ban has been reported, but the notice doesn't confirm which parts of the supply area it covers. Check with your water company before using a hosepipe. Checked 11 October 2026 at 02:34

    Environment Agency ↗

  • Storm overflows

    17 overflows within 10 km of CO11 centre

    Details

    74 spills in 2025

  • Lead pipes

    45% built before 1973

    Details

    Estimate, not a test. Homes in the parts of CO11 we can match to council-tax records (100% of its postcodes) whose build period is known; the share with no recorded build period isn't published for these areas. Allowing for suppressed counts: 44–45%. England and Wales: 61% (2026).

    Ask Affinity Water for a free lead test

    Lead test kits

Who supplies water in CO11

Boundary or unplaced: 11 postcodes

Drinking-water test record

Affinity Water: 462 of 576 postcodes

Affinity Water

Affinity Water, company-wide

Regulator
DWI
Report year
2025
Failed tests
Not shown
Tests
189,963

The regulator's published total and its company rows disagree, so we don't show a count.

Failed tests by parameter
E. coli (confirmed)Failed tests: 4
Enterococci (confirmed)Failed tests: 2
IronFailed tests: 1
LeadFailed tests: 6
NickelFailed tests: 3
Total coliforms (confirmed)Failed tests: 4

Source: DWI england 2025, Annex B — dated 6 July 2026, read 13 October 2026

Source: DWI england 2025, Annex A — dated 6 July 2026, read 13 October 2026

England: 99.97% of tests met standards in 2025 (DWI).

Source: DWI england 2025, national compliance — dated 6 July 2026, read 13 October 2026

Anglian Water: 103 of 576 postcodes

Anglian Water

Anglian Water group, includes Anglian Water

Regulator
DWI
Report year
2025
Failed tests
Not shown
Tests
384,536

The regulator's published total and its company rows disagree, so we don't show a count.

Failed tests by parameter
CopperFailed tests: 1
E. coli (confirmed)Failed tests: 1
IronFailed tests: 6
LeadFailed tests: 2
NickelFailed tests: 3
Total coliforms (confirmed)Failed tests: 10
Turbidity – indicatorFailed tests: 2

Source: DWI england 2025, Annex B — dated 6 July 2026, read 13 October 2026

Source: DWI england 2025, Annex A — dated 6 July 2026, read 13 October 2026

England: 99.97% of tests met standards in 2025 (DWI).

Source: DWI england 2025, national compliance — dated 6 July 2026, read 13 October 2026

How hard is the water in CO11?

79% of CO11's postcodes are in the Underground 2 Zone supply zone (Affinity Water): 312 mg/l, very hard.

Underground 2 Zone · Affinity Water (456 of 576 postcodes)

312 mg/l · 21.9 °Clark · 17.5 °dH · 31.2 °fH

Very hard

From the company's postcode lookup.

Underground 2 Zone (supply zone) · read on 28 September 2026

Source: Affinity Water — read 28 September 2026

3 identified supply zones in CO11

Underground 2 Zone · Affinity Water (456 of 576 postcodes)

312 mg/l · 21.9 °Clark · 17.5 °dH · 31.2 °fH

Very hard

From the company's postcode lookup.

Underground 2 Zone (supply zone) · read on 28 September 2026

Source: Affinity Water — read 28 September 2026

Raydon/Alton PWSZ · Anglian Water (103 of 576 postcodes)

at least 357 mg/l · at least 25.0 °Clark · at least 20.0 °dH · at least 35.7 °fH

At least very hard

Zone average. At least 357 mg/l (very hard or harder); total hardness is higher.

Raydon/Alton PWSZ (supply zone) · January 2025 to December 2025

Source: Anglian Water — dated January 2025 to December 2025, read 28 September 2026

Surface Zone · Affinity Water (1 of 576 postcodes)

227 mg/l · 15.9 °Clark · 12.7 °dH · 22.7 °fH

Hard

From the company's postcode lookup.

Surface Zone (supply zone) · read on 28 September 2026

Source: Affinity Water — read 28 September 2026

5 postcodes without an identified supply zone

Affinity Water (5 of 576 postcodes)

We do not have a verified hardness figure for this area. Ask your water company for its water quality report.

Ask your water company

Storm overflows nearby

17 overflows within 10 km of CO11 centre · 74 spills in 2025

CO11 (district) · 2025

Source: Environment Agency EDM annual return 2025 — dated 20 August 2026, read 13 October 2026

Overflows here are run by Anglian Water.

9 of these were monitored for only part of 2025.

Nearest 5 shown

  1. MISTLEY SCHOOL LANE MH9602 LM

    Into River Stour · 0.4 km from the centre of CO11

    7 spills · 1.1 hours · Monitored 78.3% of 2025

  2. MANNINGTREE(LAWFORD) STW

    Into Wignall Brook Stour Estuary · 1.9 km from the centre of CO11

    5 spills · 11.1 hours · Monitored 99.9% of 2025

  3. BRANTHAM - FACTORY LANE (B) TPS

    Into Trib River Stour · 1.9 km from the centre of CO11

    0 spills · 0 hours · Monitored 92.3% of 2025

  4. BRANTHAM - FACTORY LANE (B) TPS

    Into Trib River Stour · 2 km from the centre of CO11

    2 spills · 0.5 hours · Monitored 100% of 2025

  5. WIGNALL STREET PS

    Into Trib Wignall Brook · 2.8 km from the centre of CO11

    2 spills · 5 hours · Monitored 99.9% of 2025

Annual 2025 figures from monitored overflows. Not live, and not a bathing-water or tap-water verdict.

  • 57 England outfalls in the 2025 return had no usable location and aren't counted.
  • Northern Ireland isn't covered: No licensed annual per-outfall source in the approved source list; BT postcode coordinates require an LPS licence.

Older homes and lead pipes

45% built before 1973

45% of homes here were built before 1973 — estimate, not a test.

Homes in the parts of CO11 we can match to council-tax records (100% of its postcodes) whose build period is known; the share with no recorded build period isn't published for these areas. Allowing for suppressed counts: 44–45%. England and Wales: 61% (2026).

Older homes are more likely to have lead pipes. Only a test tells you whether yours does.

CO11 (district) · 2026

Source: Valuation Office Agency, Council Tax: stock of properties — dated 31 March 2026, read 24 September 2026

Fluoride

We cannot confirm whether this area is part of a water fluoridation scheme. Ask your water supplier using your postcode.

About fluoride in UK water

Around one in ten people in England receive drinking water supplied by a fluoridation scheme.

England · 2026 health monitoring report

Source: UKHSA and DHSC — dated 30 March 2026, read 13 October 2026

Fluoride in UK tap water

Hosepipe bans

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What you can do

As an Amazon Associate we earn from qualifying purchases. Links go to amazon.com; Amazon's Earn Globally service can localise them to amazon.co.uk. Check the model and UK delivery before buying.

Water filter jugs

  • LifeStraw

    LSH7GLSPK21

    Performance certification:

    Certified by WQA to NSF/ANSI 42 for Aesthetic Chlorine and Taste and Odor; Certified by WQA to NSF/ANSI 53 for Lead and Mercury; Certified by WQA to NSF/ANSI 401 for Microplastics (a US/international standard; it is not UK approval)

    reduces chlorine taste and odour in drinking water.

    A UK retailer lists this model. Amazon UK stock and delivery are unverified; this Amazon link may not ship to the UK. Check the exact model and UK delivery before you pay.

    UK availability evidence checked 14 October 2026.

    View Details

Shower filters

  • Weddell Water

    WD-100BL

    Performance certification:

    Certified by NSF to NSF/ANSI 177 for Free Available Chlorine Reduction (a US/international standard; it is not UK approval)

    reduces chlorine in shower water; does not soften water.

    A UK retailer lists this model. Amazon UK stock and delivery are unverified; this Amazon link may not ship to the UK. Check the exact model and UK delivery before you pay.

    Check it fits your shower fitting before buying; a US fitting may need an adaptor.

    UK availability evidence checked 14 October 2026.

    View Details

We haven't verified a water softener for UK buyers yet.

What a pick has to pass:

  • An exact-model listing from NSF, WQA or IAPMO for the model sold in the UK
  • Listed to NSF/ANSI 44, the water softener standard
  • The manufacturer's documented feed connection and water-pressure range, so a plumber can check them against UK pipework
  • UK availability evidenced by Amazon UK, the manufacturer or a UK retailer, checked in the last 90 days

Until we can recommend one, see what a softener costs to buy, fit and run in the UK. Water softener cost

We haven't verified a lead test kit for UK buyers yet.

What a pick has to pass:

  • A lead result reported by a laboratory accredited for that test (UKAS, ISO/IEC 17025), named on the kit's listing
  • UK availability evidenced by Amazon UK, the manufacturer or a UK retailer, checked in the last 90 days

Start with your water company: if you think you have lead pipes, you can ask it to test the water at your kitchen tap. Which water test you need

Common water problems

Questions about tap water in CO11

Is the water in CO11 hard or soft?
Affinity Water: very hard, 312 mg/l, 21.9 °Clark, 17.5 °dH, 31.2 °fH (Underground 2 Zone (supply zone), read on 28 September 2026). From the company's postcode lookup. Anglian Water: at least very hard, at least 357 mg/l, at least 25.0 °Clark, at least 20.0 °dH, at least 35.7 °fH (Raydon/Alton PWSZ (supply zone), January 2025 to December 2025). Zone average. At least 357 mg/l (very hard or harder); total hardness is higher. Affinity Water: We do not have a verified hardness figure for this area. Ask your water company for its water quality report. Affinity Water: hard, 227 mg/l, 15.9 °Clark, 12.7 °dH, 22.7 °fH (Surface Zone (supply zone), read on 28 September 2026). From the company's postcode lookup.
What does the drinking water regulator's record show for CO11?
Affinity Water: at least 20 tests failed UK drinking-water standards in 2025 (DWI, company-wide). Some published DWI figures don't reconcile or identify a company, so we've left them out; the true number may be higher. England overall: 99.97% of tests met standards.
Could homes in CO11 have lead pipes?
45% of homes here were built before 1973 — estimate, not a test. Homes in the parts of CO11 we can match to council-tax records (100% of its postcodes) whose build period is known; the share with no recorded build period isn't published for these areas. Allowing for suppressed counts: 44–45%. England and Wales: 61% (2026). Older homes are more likely to have lead pipes. Only a test tells you whether yours does.
Is the water in CO11 fluoridated?
We cannot confirm whether this area is part of a water fluoridation scheme. Ask your water supplier using your postcode. Around one in ten people in England receive drinking water supplied by a fluoridation scheme.
Sources and method

Anglian Water contact page, Affinity Water, Affinity Water: Database right, used under the publisher's terms.

Water company boundaries © Water UK, licensed under CC BY 4.0Contains public sector information licensed under the Open Government Licence v3.0All content is available under the Open Government Licence v3.0, except where otherwise stated © Crown copyright

Data generation uk-2026-10-16-derive6

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By TapWaterData Editorial

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