England's own count of private water supplies — each one a borehole, a spring, a watercourse or an onward distribution of the mains measures 36,335 sites of private water supply, as its local authorities reported them for the 2025 reporting year, per Drinking Water Inspectorate — Drinking Water 2025 — Private water supplies in England, Introduction (read 21 September 2026).
Source: Drinking Water Inspectorate — Drinking Water 2025 — Private water supplies in England, Introduction — read 21 September 2026
Drinking Water Inspectorate (DWI) enforces the UK drinking water quality regulations in England and Wales. Figures it classifies or regulates on this page cover England and Wales only.
Why this page is organised by nation
A property that takes its water from its own source is not connected to a water company, so there is no company to hold a record of it and no company whose compliance figures answer a question about it. The duty sits somewhere else, and where it sits depends on which nation the property is in.
That is why every statement below is filed under a nation, printed in the words of a body that publishes for that nation, and linked to the regulations that nation made. Nothing on this page is offered as an answer for the country as a whole, because for this subject the country as a whole does not have one.
Why two bodies with the same name are not the same body
One of the names below belongs to two different organisations, in two different nations, with different duties. In one pair of nations it advises the bodies that regulate; in another it holds the register and runs the sampling itself. Reading a sentence about one as though it described the other would reverse who is responsible for a supply.
So each nation's section names the body it means and prints the passage that names it directly underneath, with the document and the day it was read. Where a description here and a quotation there disagree, the quotation is the one that was published.
Why there is no advice on this page
Everything inside quotation marks was transcribed from a page or a regulation that this site opened on a stated day, and the body it was transcribed from is committed alongside the code so each sentence can be checked against it without trusting anybody. Some of those passages tell a reader to do something; they are the publisher's instructions, printed whole and attributed, not shortened and not restated.
Everything outside quotation marks is either a figure with its own source beside it, or a sentence about how the page was put together. There is nothing here about what to buy, nobody to call, and no step to take that a regulator has not published in its own words.
Why some of the sections below say what is missing
A page can be wrong by stating something false, and it can be wrong by leaving a reader to assume something it never checked. The second is harder to see, so where this site looked for a thing and did not find it, the search itself is written down: what was sought, where it was sought, and what the source said instead.
One of those searches ended in a document that had been amended. A figure that was once set in law had been removed from it, and the version still linked from elsewhere carries the old text. It is recorded here rather than repeated, because a withdrawn figure restated as a number reads exactly like a current one.
Who is responsible, nation by nation
The rules below were read from documents about England, Wales, Scotland and Northern Ireland, and each nation is answered only from documents about that nation.
England
Who regulates a private supply here: Local authorities, with the Drinking Water Inspectorate as their technical adviser.
The law that applies here is The Private Water Supplies (England) Regulations 2016.
A private water supply (PWS) is any water supply which is supplied to a property and does not originate from a mains supply or licensed water supplier.
Source: Drinking Water Inspectorate — Private Water Supplies — consumer guidance — read 21 September 2026
LAs act as the regulators for PWS and have statutory duties under the PWS Regulations, and as such should be your first point of contact for testing and identified risks.
Source: Drinking Water Inspectorate — Private Water Supplies — consumer guidance — read 21 September 2026
The DWI has a statutory role to act as technical advisors to LAs in relation to the implementation of the PWS Regulations.
Source: Drinking Water Inspectorate — Private Water Supplies — consumer guidance — read 21 September 2026
Most of these supplies are situated in remote, rural parts of the country and can originate from a range of sources including: boreholes, natural springs, and watercourses.
Source: Drinking Water Inspectorate — Private Water Supplies — consumer guidance — read 21 September 2026
The standards and principles of regulation are the same for both public and private water supplies: to protect public health equitably regardless of the source of the water supply.
Source: Drinking Water Inspectorate — Drinking Water 2025 — Private water supplies in England, Introduction — read 21 September 2026
Around 1.5% of the population in England uses a private water supply, although this is significantly under-reported due to the lack of mandatory registration and local authorities not meeting their statutory reporting duties.
Source: Drinking Water Inspectorate — Drinking Water 2025 — Private water supplies in England, Introduction — read 21 September 2026
local authorities are still not fully delivering their statutory duties, which aim to protect public health.
Source: Drinking Water Inspectorate — Drinking Water 2025 — Private water supplies in England, Introduction — read 21 September 2026
A local authority may charge a fee, payable on invoice, for the activities in the following Table, and the fee is the reasonable cost of providing the service
Source: legislation.gov.uk — The Private Water Supplies (England) Regulations 2016, SCHEDULE 5 (Fees), as amended — read 21 September 2026
Words in Sch. 5 para. 1 omitted (11.7.2018) by virtue of The Private Water Supplies (England) (Amendment) Regulations 2018
Source: legislation.gov.uk — The Private Water Supplies (England) Regulations 2016, SCHEDULE 5 (Fees), as amended — read 21 September 2026
Sites reported for 2025: 36,335 sites
Source: Drinking Water Inspectorate — Drinking Water 2025 — Private water supplies in England, Introduction — read 21 September 2026
Reported population for 2025: 866,230 people
Source: Drinking Water Inspectorate — Drinking Water 2025 — Private water supplies in England, Introduction — read 21 September 2026
Local authorities that reported for 2025: 223 local authorities
Source: Drinking Water Inspectorate — Drinking Water 2025 — Private water supplies in England, Introduction — read 21 September 2026
Wales
Who regulates a private supply here: Local authorities, with the Drinking Water Inspectorate as their technical adviser.
The law that applies here is The Private Water Supplies (Wales) Regulations 2017.
A private water supply (PWS) is any water supply which is supplied to a property and does not originate from a mains supply or licensed water supplier.
Source: Drinking Water Inspectorate — Private Water Supplies — consumer guidance — read 21 September 2026
LAs act as the regulators for PWS and have statutory duties under the PWS Regulations, and as such should be your first point of contact for testing and identified risks.
Source: Drinking Water Inspectorate — Private Water Supplies — consumer guidance — read 21 September 2026
The DWI has a statutory role to act as technical advisors to LAs in relation to the implementation of the PWS Regulations.
Source: Drinking Water Inspectorate — Private Water Supplies — consumer guidance — read 21 September 2026
3.27% of the population in Wales use a private water supply, although this is believed to be significantly under-reported due to the lack of mandatory registration and local authorities not meeting their statutory reporting duties.
Source: Drinking Water Inspectorate — Drinking Water 2025 — Private water supplies in Wales, Introduction — read 21 September 2026
While the number of supplies has remained stable in the last few years, it is estimated that there are a further 41,764 supplies (Welsh Government, 2021) which are not registered with local authorities.
Source: Drinking Water Inspectorate — Drinking Water 2025 — Private water supplies in Wales, Introduction — read 21 September 2026
Sites reported for 2025: 14,902 sites
Source: Drinking Water Inspectorate — Drinking Water 2025 — Private water supplies in Wales, Introduction — read 21 September 2026
Reported population for 2025: 104,431 people
Source: Drinking Water Inspectorate — Drinking Water 2025 — Private water supplies in Wales, Introduction — read 21 September 2026
Local authorities that reported for 2025: 22 local authorities
Source: Drinking Water Inspectorate — Drinking Water 2025 — Private water supplies in Wales, Introduction — read 21 September 2026
Scotland
Who regulates a private supply here: Local authorities.
The law that applies here is The Water Intended for Human Consumption (Private Supplies) (Scotland) Regulations 2017.
In Scotland, private water supplies are defined as those that are not provided by Scottish Water.
Source: Drinking Water Quality Regulator for Scotland — Private Water Supplies — read 21 September 2026
Approximately 3% of the Scottish population uses a private water supply for drinking water.
Source: Drinking Water Quality Regulator for Scotland — Private Water Supplies — read 21 September 2026
There are two types of private water supply (PWS), and the legislation relating to each is different.
Source: Drinking Water Quality Regulator for Scotland — Private Water Supplies — read 21 September 2026
Larger PWS or those with a commercial activity are defined as Regulated supplies.
Source: Drinking Water Quality Regulator for Scotland — Private Water Supplies — read 21 September 2026
Smaller PWS that only serve domestic properties are classified as Exempt supplies.
Source: Drinking Water Quality Regulator for Scotland — Private Water Supplies — read 21 September 2026
Private water supplies are regulated by local authorities.
Source: Drinking Water Quality Regulator for Scotland — Owners and Users of Private Water Supplies — read 21 September 2026
It is your responsibility to manage your supply and keep it safe.
Source: Drinking Water Quality Regulator for Scotland — Owners and Users of Private Water Supplies — read 21 September 2026
The Private Water Supply grant is also administered by local authorities, on behalf of the Scottish Government.
Source: Drinking Water Quality Regulator for Scotland — Owners and Users of Private Water Supplies — read 21 September 2026
You may be able to get a grant of up to £800 to help with the costs of improving a private supply.
Source: Scottish Government — Owning or using a private water supply — dated 2 May 2025, read 21 September 2026
This page holds no count of private water supplies for Scotland: nothing it has read from this nation publishes one.
Northern Ireland
Who regulates a private supply here: The Drinking Water Inspectorate at the Department of Agriculture, Environment and Rural Affairs.
The law that applies here is The Private Water Supplies Regulations (Northern Ireland) 2017.
Private water supplies are any supplies of water not provided by the public water supplier.
Source: Department of Agriculture, Environment and Rural Affairs — Private Water Supplies — read 21 September 2026
In Northern Ireland less than one per cent of water comes from private water supplies.
Source: Department of Agriculture, Environment and Rural Affairs — Private Water Supplies — read 21 September 2026
The DWI monitors private water supplies to ensure they meet standards set within the regulations.
Source: Department of Agriculture, Environment and Rural Affairs — Private Water Supplies — read 21 September 2026
The DWI holds a register of all known private water supplies in Northern Ireland that come under the Private Water Supplies Regulations.
Source: Department of Agriculture, Environment and Rural Affairs — Private Water Supplies — read 21 September 2026
An annual monitoring programme is in place to check the quality of each registered supply.
Source: Department of Agriculture, Environment and Rural Affairs — Private Water Supplies — read 21 September 2026
The frequency of the sample collection and the range of parameters (microbiological, chemical, or radioactivity) tested for are determined by the type of private water supply and the volume of water used or the size of the population served.
Source: Department of Agriculture, Environment and Rural Affairs — Private Water Supplies — read 21 September 2026
If your private water supply is to a single private dwelling it is not required to be monitored by the Drinking Water Inspectorate.
Source: Department of Agriculture, Environment and Rural Affairs — Private Water Supplies — read 21 September 2026
Owners/users of private water supplies have responsibility under the private water supplies regulations to supply water that is wholesome and safe to drink.
Source: Department of Agriculture, Environment and Rural Affairs — Private Water Supplies — read 21 September 2026
This page holds no count of private water supplies for Northern Ireland: nothing it has read from this nation publishes one.
What this site has measured itself
Nothing on this page is our own measurement. Every figure and every quotation above was published by one of the named bodies, and no sample behind them was taken by us. A reader who wants their own supply tested can find a certified laboratory at our testing directory.
What this page does not tell you
Why there is no record of any particular supply on this page
What was looked for: a result for one named private water supply — a determinand, a value and the date the sample was taken. Where: the four nations' own private-supply publications: the Inspectorate's annual reports for England and for Wales, the Regulator's guidance for Scotland, and the Department's article for Northern Ireland.
What it says instead: “Around 1.5% of the population in England uses a private water supply, although this is significantly under-reported due to the lack of mandatory registration and local authorities not meeting their statutory reporting duties.”
What would change this: a per-supply register that is both national and complete. Northern Ireland is the only nation here whose publications describe one, and it covers the supplies its own regulations reach rather than every supply that exists. Until a nation publishes per-supply results in bulk, this page states the law and the counts and no result of its own.
Source: Drinking Water Inspectorate — Drinking Water 2025 — Private water supplies in England, Introduction — read 21 September 2026
Why there is no price on this page
What was looked for: what a private water supply costs the person responsible for it — a charge for a risk assessment, a sampling visit or an analysis. Where: the fee schedule of the England regulations, in the consolidated text rather than the version as originally made.
What it says instead: “A local authority may charge a fee, payable on invoice, for the activities in the following Table, and the fee is the reasonable cost of providing the service”
What would change this: each local authority's own published fee schedule, which is set council by council. The maximum amounts this schedule carried when it was made were removed from it in 2018, so there is no longer a national ceiling to quote, and the withdrawn amounts are not restated here as figures.
Source: legislation.gov.uk — The Private Water Supplies (England) Regulations 2016, SCHEDULE 5 (Fees), as amended — read 21 September 2026
Why there is no single answer to how often a supply is sampled
What was looked for: one statement of how often a private water supply is sampled that is true across the United Kingdom. Where: each nation's own regulator page, all four of which were read on the same day.
What it says instead: “The frequency of the sample collection and the range of parameters (microbiological, chemical, or radioactivity) tested for are determined by the type of private water supply and the volume of water used or the size of the population served.”
What would change this: the four nations' regulations, which set monitoring separately and are linked under each nation below. The sentence above is one nation's rule, and it is printed under that nation rather than as a United Kingdom answer.
Source: Department of Agriculture, Environment and Rural Affairs — Private Water Supplies — read 21 September 2026