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Crofton Park Water Hardness & Quality Report (2026)

Water Hardness

316mg/L
Very Hard

22.2°Clark31.6°fH17.7°dH

Source

mixed

pH Level

8.5

neutral = 7.0

Lead

0.005 mg/L

✓ Below action level

TDS

915.6 mg/L

Est. Daily Cost

£0.72

energy & soap waste

Source: DWI Data Portal · Updated 2026

316mg/L as CaCO₃Very Hard

0–60

mg/L

Soft

61–120

mg/L

Moderately Hard

121–180

mg/L

Hard

180+

mg/L

Very Hard

Appliance Damage Report

In Crofton Park, your appliances are currently losing 42% efficiency due to mineral buildup.

ApplianceIn Crofton ParkSoft Water CityEfficiency Loss
Kettle
1.5 yrs
8.5 yrs-82%
Washing Machine
3 yrs
12 yrs-75%
Water Heater
5 yrs
15 yrs-67%

Regional Water Comparison

How Crofton Park compares to its nearest neighbours

CityHardnessClark°RiskSource
Crofton Park, Greater London316 mg/L22.2°🔴 Very Hardmixed
Forest Hill, Greater London327 mg/L22.9°🔴 Very Hardmixed
Brockley, Greater London315.5 mg/L22.1°🔴 Very Hardmixed
Ladywell, Greater London316.5 mg/L22.2°🔴 Very Hardmixed
Catford, Greater London280 mg/L19.6°🔴 Very Hardmixed

National Benchmark

How Crofton Park compares to the United Kingdom average

BenchmarkHardnessAppliance Risk
Crofton Park316 mg/L🔴 High
United Kingdom National Avg183 mg/L🔴 High
Livingston Top Rated8.5 mg/L🟢 None

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What Makes Crofton Park's Water Unique?

Local geology and source profile

Source: MixedTDS: 915.6 mg/LpH: 8.5

Thames Water supplies Crofton Park in the London Borough of Lewisham in south-east London near Forest Hill and Honor Oak, via the Thames Water south London ring main drawing from Bough Beech Reservoir in Kent and the River Thames at Walton. At 316 mg/L (22.2°Clark) and a TDS of 915.6 mg/L, Crofton Park's water is extremely hard — among the very hardest supplies anywhere in Greater London — driven by an exceptionally high chalk mineral fraction in the distribution blend reaching this part of the south-east London Lewisham supply zone.

The Bough Beech Reservoir receives water from the highly mineralised North Downs Chalk streams of the Eden Valley in west Kent, treated at Bough Beech works. In the Crofton Park and Forest Hill distribution zone, the Thames Water south London ring main blend appears to incorporate a remarkably high proportion of this deeply chalk-mineralised supply — producing 316 mg/L hardness with TDS 915.6 mg/L, comparable to the most extreme confined chalk aquifer zones in the entire UK dataset and dramatically exceeding the hardness recorded in neighbouring Lewisham zones like New Cross (194.5 mg/L) and Perry Vale (269 mg/L). This exceptional mineralisation suggests a specific supply routing through the south London network that delivers the most concentrated chalk fraction to the Crofton Park distribution sub-zone.

At 316 mg/L, limescale is an extreme household challenge in Crofton Park. Kettles must be descaled weekly to prevent rapid element failure. The combi-boiler faces very high risk of premature breakdown without a properly fitted, annually replaced scale inhibitor and frequent professional servicing. Washing-up liquid barely lathers without generous quantities of product. Taps, shower heads, and all basin fittings develop heavy chalk encrustation within days to one week; at minimum a weekly descaling with white vinegar or a proprietary product is essential. A whole-house water softener is very strongly recommended for all Crofton Park households.

Geology & Source: Supplied by Thames Water from the River Thames and Bough Beech Reservoir with a high chalk mineralisation fraction in the south-east London distribution — treated at Bough Beech Water Treatment Works — produces extremely hard water at 316 mg/L (22.2°Clark).

Other Greater London Water Reports

Frequently Asked Questions

Is Crofton Park's water safe to drink?
Yes. Crofton Park's water meets all federal safety standards. The hardness is 316 mg/L (Very Hard), which is safe to drink. High hardness affects appliances and taste, but poses no health risk.
Do I need a water softener in Crofton Park?
At 316 mg/L (Very Hard), Crofton Park's water will cause significant limescale on kettles, washing machines, and water heaters. A water softener or descaler is strongly recommended to extend appliance lifespan and reduce energy bills by up to 42%.
How does Crofton Park compare to the United Kingdom average?
The United Kingdom national average is 183 mg/L. Crofton Park at 316 mg/L is 133 mg/L above the national average. The softest major city is Livingston at just 8.5 mg/L.