CO9 tap water: what's in it?
Anglian Water group (figures include Anglian Water): at least 25 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.
CO9 tap water quality report · 2026
Hardness
At least very hard
Halstead Urban PWSZ (supply zone) · January 2025 to December 2025
Details
Halstead Urban PWSZ (supply zone) · January 2025 to December 2025
Hosepipe ban
Hosepipe ban in force
Anglian Water (Environment Agency, 11 October 2026). Checked 11 October 2026 at 02:34
Details
Anglian Water (Environment Agency, 11 October 2026). Checked 11 October 2026 at 02:34
Storm overflows
17 overflows within 10 km of CO9 centre
130 spills in 2025
Details
130 spills in 2025
Lead pipes
57% built before 1973
Estimate, not a test. Homes in the parts of CO9 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: 56–58%. England and Wales: 61% (2026).
Details
Estimate, not a test. Homes in the parts of CO9 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: 56–58%. England and Wales: 61% (2026).
Who supplies water in CO9
Part of Anglian Water
Supplies 928 of 928 postcodes (100%)
We can't confirm your sewerage company from official data for this area.
Drinking-water test record
Anglian Water: 928 of 928 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.
| Parameter | Failed tests |
|---|---|
| Copper | Failed tests: 1 |
| E. coli (confirmed) | Failed tests: 1 |
| Iron | Failed tests: 6 |
| Lead | Failed tests: 2 |
| Nickel | Failed tests: 3 |
| Total coliforms (confirmed) | Failed tests: 10 |
| Turbidity – indicator | Failed 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 CO9?
Anglian Water (711 of 928 postcodes)
at least 393 mg/l · at least 27.6 °Clark · at least 22.0 °dH · at least 39.3 °fH
Zone average. At least 393 mg/l (very hard or harder); total hardness is higher.
Halstead Urban PWSZ (supply zone) · January 2025 to December 2025
Source: Anglian Water — dated January 2025 to December 2025, read 28 September 2026
Anglian Water (162 of 928 postcodes)
at least 313 mg/l · at least 21.9 °Clark · at least 17.5 °dH · at least 31.3 °fH
Zone average. At least 313 mg/l (very hard or harder); total hardness is higher.
Halstead Rural PWSZ (supply zone) · January 2025 to December 2025
Source: Anglian Water — dated January 2025 to December 2025, read 28 September 2026
Anglian Water (44 of 928 postcodes)
We do not have a verified hardness figure for this area. Ask your water company for its water quality report.
Anglian Water (10 of 928 postcodes)
at least 461 mg/l · at least 32.3 °Clark · at least 25.8 °dH · at least 46.1 °fH
Zone average. At least 461 mg/l (very hard or harder); total hardness is higher.
Braintree North PWSZ (supply zone) · January 2025 to December 2025
Source: Anglian Water — dated January 2025 to December 2025, read 28 September 2026
Anglian Water (1 of 928 postcodes)
at least 501 mg/l · at least 35.2 °Clark · at least 28.1 °dH · at least 50.1 °fH
Zone average. At least 501 mg/l (very hard or harder); total hardness is higher.
Haverhill PWSZ (supply zone) · January 2025 to December 2025
Source: Anglian Water — dated January 2025 to December 2025, read 28 September 2026
Storm overflows nearby
17 overflows within 10 km of CO9 centre · 130 spills in 2025
CO9 (district) · 2025
Source: Environment Agency EDM annual return 2025 — dated 20 August 2026, read 13 October 2026
Overflows here are run by Anglian Water.
14 of these were monitored for only part of 2025.
Nearest 5 shown
SIBLE HEDINGHAM STW
Into RIVER COLNE · 0.3 km from the centre of CO9
12 spills · 38 hours · Monitored 100% of 2025
SIBLE HEDINGHAM - ALDERFORD ST CSO
Into RIVER COLNE · 1 km from the centre of CO9
1 spill · 0.3 hours · Monitored 99.2% of 2025
CASTLE HEDINGHAM - QUEEN ST CSO
Into RIVER COLNE · 2.3 km from the centre of CO9
2 spills · 3.8 hours · Monitored 100% of 2025
WATER SUPPLY BOREHOLES AT PARSONAGE
Into RIVER COLNE · 3.8 km from the centre of CO9
7 spills · 10.3 hours · Monitored 97.3% of 2025
GOSFIELD STW
Into Bourne Brook River Colne NT · 4.4 km from the centre of CO9
3 spills · 20.4 hours · Monitored 100% 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
57% built before 1973
57% of homes here were built before 1973 — estimate, not a test.
Homes in the parts of CO9 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: 56–58%. England and Wales: 61% (2026).
Older homes are more likely to have lead pipes. Only a test tells you whether yours does.
CO9 (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.
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
Hosepipe bans
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)
View Detailsreduces 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.
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)
View Detailsreduces 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.
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
How much does a water softener cost in the UK?
Water softener cost UK 2026: price by home size
Why is my tap water cloudy or white?
Why is my tap water cloudy or white? (UK)
Brown tap water: causes and what to do (UK)
Why does my tap water taste metallic?
Tap water tastes metallic? Causes and fixes (UK)
Questions about tap water in CO9
- Is the water in CO9 hard or soft?
- Anglian Water: at least very hard, at least 393 mg/l, at least 27.6 °Clark, at least 22.0 °dH, at least 39.3 °fH (Halstead Urban PWSZ (supply zone), January 2025 to December 2025). Zone average. At least 393 mg/l (very hard or harder); total hardness is higher. Anglian Water: at least very hard, at least 313 mg/l, at least 21.9 °Clark, at least 17.5 °dH, at least 31.3 °fH (Halstead Rural PWSZ (supply zone), January 2025 to December 2025). Zone average. At least 313 mg/l (very hard or harder); total hardness is higher. Anglian Water: We do not have a verified hardness figure for this area. Ask your water company for its water quality report. Anglian Water: at least very hard, at least 461 mg/l, at least 32.3 °Clark, at least 25.8 °dH, at least 46.1 °fH (Braintree North PWSZ (supply zone), January 2025 to December 2025). Zone average. At least 461 mg/l (very hard or harder); total hardness is higher. Anglian Water: at least very hard, at least 501 mg/l, at least 35.2 °Clark, at least 28.1 °dH, at least 50.1 °fH (Haverhill PWSZ (supply zone), January 2025 to December 2025). Zone average. At least 501 mg/l (very hard or harder); total hardness is higher.
- What does the drinking water regulator's record show for CO9?
- Anglian Water group (figures include Anglian Water): at least 25 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 CO9 have lead pipes?
- 57% of homes here were built before 1973 — estimate, not a test. Homes in the parts of CO9 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: 56–58%. 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 CO9 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
- Water Company Boundaries (UC2) ↗ · 19 September 2026 · read 20 September 2026
- Anglian Water contact page ↗ · 13 October 2026 · read 13 October 2026
- DWI england 2025, Annex B ↗ · 2025 · read 13 October 2026
- DWI england 2025, national compliance ↗ · 2025 · read 13 October 2026
- Anglian Water ↗ · January 2025 to December 2025 · read 28 September 2026
- Environment Agency EDM annual return 2025 ↗ · 2025 · read 13 October 2026
- Valuation Office Agency, Council Tax: stock of properties ↗ · 2026 · read 24 September 2026
- UKHSA and DHSC ↗ · 2026 health monitoring report · read 13 October 2026
- Environment Agency ↗ · 11 October 2026 · read 11 October 2026
Anglian Water contact page: 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