What is chloramine, and is it in my tap water?
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Part of our tap water guide
The word turns up on water company pages and in fish-keeping groups. What is it, and does it come out of your tap? You can check the chlorine side at your own tap with a 20-in-1 test strip.
Short answer: Chloramine is chlorine combined with a little ammonia to form monochloramine, a long-lasting disinfectant that Scottish Water says reaches more than 25% of its customers (one million people). Welsh Water says none of its treatment works add it. Which applies to your tap depends on your water company.
By Andrew Tomlinson, WaterKit · Last reviewed 29 October 2026
What is chloramine?
It is a disinfectant formed when ammonia is added to chlorine. The Drinking Water Quality Regulator for Scotland (DWQR) says a small quantity of ammonia is added after the disinfection process to make monochloramine, which persists longer through the pipework. It adds that chloramination reduces the formation of some regulated by-products called trihalomethanes.
Does my tap water have chloramine?
It depends on your water company, and only some say so on their own pages. This is what we found.
| Company | What it says |
|---|---|
| Scottish Water | The company says it introduced chloramination where untreated water is highly coloured by peat and where water travels long distances, and that more than 25% of customers (one million people) receive it. The DWQR names Edinburgh, Aberdeen and Inverness as places it has been used for many years |
| Welsh Water | Its water quality page says none of its water treatment works add chloramine |
| Thames Water | The Thames Water home page, the only page of its site we read, does not say |
We have not built a full list, and a company missing from the table has not been checked rather than ruled out. Ask yours. The Drinking Water Inspectorate (DWI) says your company will give you a free water quality report on request.
On taste, the DWQR says the chlorine taste of chloraminated water is usually less noticeable, and Scottish Water says chloramines have no significant taste or odour.
What one reader found
A home brewer in south-east London researched chlorine and chloramines in brewing water and wrote to Thames Water. In a September 2012 post they said Thames told them it uses chloramines to keep water pure at the tap after chlorine treatment at the works. They reported that their area's report dated 10 April 2012 showed a residual disinfectant level of 0.42 mg/l, the mean of 94 samples taken in 2011, and that the peak in the inspectorate data was 0.92 mg/l. They also wrote that "Boiling will not remove chloramines either."
This is one person's account from 2012, which we have not checked with Thames Water. Our London tap water guide covers the capital more broadly. Shared on Jim's Beer Kit Home Brew Forum.
Why might the chloramine at my tap differ from the area picture?
The area figure is an average. The DWI says a property near the treatment works may get a little more chlorine than one several miles away, and that levels can be higher for a while during maintenance. Welsh Water says its zone reports summarise all samples in each zone over a year and are not property specific.
“The area figure is only an average, so I would not assume it describes your own tap, which sits at the end of its own run of pipe and may well differ. Checking the tap you actually drink from is a sensible way to see what is really coming out of it.”
Inside the home, the DWI says a strong or TCP-like taste can point to home plumbing, such as appliance hoses.
A private supply is a different case, because no company manages it. The DWI's manual for small supplies says that chlorinating water that contains ammonia produces chloramines, which are less potent disinfectants than chlorine and can cause taste and odour complaints. Our well and borehole guide covers those supplies.
Can you remove chloramine from tap water?
In the sources we read, the answer is a conditioner or filtration product made for the purpose. Scottish Water says water conditioning agents and filtration systems are available. The DWQR says fishkeepers need a slightly different product for chloraminated water from the one used for chlorine, and Scottish Water says adjustments to equipment for kidney dialysis may be needed. Our fish tank and pond guide covers tank water.
The DWI's simple fixes, a jug of tap water in the fridge or an activated carbon jug filter, are described for chlorine. We read nothing in the sources saying they work on chloramine. Before choosing a treatment, a WaterKit strip can indicate whether your tap carries a chlorine residual at or above the first 0.5 mg/l step.
How can I check my own tap for chlorine and chloramine?
In our reading of the chart, a total chlorine pad that reads higher than the free chlorine pad may point to combined chlorine, the group chloramine belongs to. The DWI describes the residual as free or combined chlorine, and our results portal describes the total pad as free and combined chlorine together. We have not tested how either pad responds to chloramine, so we make no claim about that, and the strip gives no chloramine concentration. The table is our reading of the chart steps.
| Free pad | Total pad | WaterKit's reading |
|---|---|---|
| 0 | 0 | Both below the first 0.5 mg/l step, so no gap to read |
| 0 | 0.5 or more | May point to combined chlorine, a group that includes chloramine |
| 0.5 or more | A step or more higher | Indicates free and combined chlorine together |
Both pads read 0, 0.5, 1, 3, 5, 10 and 20 mg/l. Fill a clean glass from the cold kitchen tap, dip one strip, wait 30 to 60 seconds and match the pads to the chart, or enter the colours in the free results checker (scan the QR code on the chart, no app or account needed). A gap smaller than one step will not show. The DWI says water companies in England and Wales typically keep residual disinfectant to 0.5 mg/l or less, at or below the first step, so a low residual may read 0 on both pads. A strip result is not a legal sample. Our home water testing guide covers the full strip.
The area figure is an average, and your own tap may differ, because the DWI says a property near the treatment works may get a little more chlorine than one several miles away and Welsh Water says its zone reports are not property specific. The free chlorine and total chlorine pads are the ones that matter here. A total pad a step or more above the free pad may point to combined chlorine at your tap, and a change in either pad between a morning draw after water has stood and a later reading would indicate that the residual at your tap is moving. Best pack: 20 strips, enough to check the tap in the morning after water has stood and again later in the day, £5.99 (or £10.99 with a bacteria test), with free 2nd Class delivery on every order. See the kit
Your chloramine questions
What is chloramine? What is a chloramine?
Chlorine combined with ammonia, used by some water companies as a longer-lasting disinfectant, according to the DWQR and Scottish Water.
Does Thames Water use chloramine?
The Thames Water home page, the only page of its site we read, does not say. Ask Thames Water which applies to your address.
How to remove chloramine from water? How to remove chloramine from tap water? How to get rid of chloramine in water? How to remove chloramine from water naturally?
In the sources we read, the only methods named are conditioning agents and filtration systems, and we found no natural method described.
Does ascorbic acid neutralize chloramine? Does acetic acid neutralize chloramine? Does acetic acid remove chloramine? Does acetic acid remove chloramine from water? Does citric acid remove chloramine?
The sources we read do not mention ascorbic, acetic or citric acid.
Does boiling water remove chloramine?
The DWI, DWQR and water company pages we read do not say.
Does catalytic carbon remove chloramine?
The sources we read do not mention catalytic carbon.
What is chloramine gas? What does chloramine gas smell like?
The sources we read do not cover chloramine gas or its smell.
Sources
- Drinking Water Quality Regulator for Scotland, Chloramination (monochloramine, longer persistence, trihalomethanes, Edinburgh, Aberdeen and Inverness, taste less noticeable, fishkeepers; undated page; read 29 October 2026).
- Scottish Water, Chloramination FAQs (peat-coloured water, long distances, no significant taste or odour, more than 25% of customers, fish and dialysis; undated page; read 29 October 2026).
- Dŵr Cymru Welsh Water, Water quality in the home (none of its treatment works add chloramine; zone reports are annual summaries and not property specific; undated page; read 29 October 2026).
- Thames Water, home page, thameswater.co.uk (no statement on chloramine on the page we read; undated; read 29 October 2026). Not linked, in line with our linking rules for this company.
- Drinking Water Inspectorate, Chlorine (free or combined chlorine typically 0.5 mg/l or less, variation with distance from the works, loft tanks, plumbing tastes, free water quality report; undated page; read 29 October 2026).
- Drinking Water Inspectorate, Manual on treatment for small water supply systems (section 2.4.2 on ammonia and chloramines; adapted from a 2001 report; undated page; read 29 October 2026).
- Home brewing forum post, Removing chlorine & chloramines from London brewing water (Jim's Beer Kit Home Brew Forum, posted 21 September 2012; one customer's account, not checked by us; read 29 October 2026).
- WaterKit, Water Test Kit (20-in-1 strip, 30 to 60 second read, optional rapid coliform test) and results portal. The strip-chart table is WaterKit's own reading of the colour chart steps.
Contains public sector information licensed under the Open Government Licence v3.0.