Company lists · Data refreshed September 2026

Top 25 Water treatment companies based in the United Kingdom

Name: Water treatment companies based in the United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 7, 2026 387 companies tracked

RevenueBase identified 387 water treatment companies headquartered in the United Kingdom as of September 2026 and tracks 5,421 professional contacts across them, including 2,292 with verified work emails and 291 with mobile numbers. London is the largest hub.

This list covers water treatment companies headquartered in the United Kingdom, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 7, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 7, 2026 86% judged on-target in blind review

387Companies

5,421Contacts tracked

2,292Verified emails

291Mobile numbers

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The 25 largest water treatment companies based in the United Kingdom

Ranked by team size

Top 25 of 387 water treatment companies based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 7, 2026. RevenueBase Smart Search rates how each company's information relates to water treatment companies: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	RSE	Partial evidence	Inverness Highlands, United KingdomHQ checked Sep 7, 2026	501-1,000	498 contacts →
	“RSE is a trusted clean water technology company, developing market leading products and solutions for purifying drinking water, recycling wastewater and cleaning water in…” Source: company website · checked Sep 7, 2026
2	Selwood LTD	Strong evidence	Eastleigh, United KingdomHQ checked Sep 7, 2026	501-1,000	477 contacts →
	“Selwood is your trusted partner in mission-critical water handling, storage, and treatment solutions across the UK.” Source: company website · checked Sep 7, 2026
3	Culligan UK	Partial evidence	Dereham, United KingdomHQ checked Sep 7, 2026	501-1,000	231 contacts →
	“Culligan UK delivers innovative, high-quality water solutions to homes and businesses across the United Kingdom.” Source: company website · checked Sep 7, 2026
4	Biwater	Partial evidence	Surrey, United KingdomHQ checked Sep 7, 2026	501-1,000	178 contacts →
	“Biwater is a world leader in treated water, providing large-scale water and wastewater solutions for clients across the world.” Source: company website · checked Sep 7, 2026
5	Severn Trent Services	Indirect evidence	Coventry, United KingdomHQ checked Sep 7, 2026	1,001-5,000	137 contacts →
	“Severn Trent Services offer a range of services to municipal and industrial clients, including the Ministry of Defence and the Coal Authority, for design, build and operation of…” Source: company website · checked Sep 7, 2026
6	Enpure	Strong evidence	Birmingham, United KingdomHQ checked Sep 7, 2026	51-200	113 contacts →
	“Enpure is a process engineering company specializing in water, wastewater and sludge treatment as well as waste-to-energy solutions with a global presence.” Source: company website · checked Sep 7, 2026
7	Salt Separation Services Limited	Strong evidence	Rochdale, United KingdomHQ checked Sep 7, 2026	51-200	80 contacts →
	“Salt Separation Services Limited is an independent water treatment company specialising in the design, manufacture, installation and commissioning of water treatment systems.” Source: company website · checked Sep 7, 2026
8	Feedwater Limited	Strong evidence	Moreton, United KingdomHQ checked Sep 7, 2026	51-200	79 contacts →
	“Feedwater Ltd is a UK Water Treatment Company, established in 1976 specifically to supply products and services for the treatment of water for steam boilers, cooling towers…” Source: company website · checked Sep 7, 2026
9	Nijhuis Saur Industries UK And Ireland	Partial evidence	United Kingdom & Ireland, United KingdomHQ checked Sep 7, 2026	201-500	76 contacts →
	“At Nijhuis Saur Industries UK & Ireland our aim is to help our customers realise the value of their water and wastewater.” Source: company website · checked Sep 7, 2026
10	Envirogen Group	Strong evidence	Alfreton, United KingdomHQ checked Sep 7, 2026	201-500	75 contacts →
	“Envirogen Group is a global leader in industrial water treatment and process filtration solutions.” Source: company website · checked Sep 7, 2026
11	Siltbuster LTD	Strong evidence	Monmouth, United KingdomHQ checked Sep 7, 2026	51-200	75 contacts →
	“At Siltbuster Ltd, we operate the UK’s largest rental fleet of water treatment systems, setting the industry benchmark for rapid, reliable, and cost-effective solutions.” Source: company website · checked Sep 7, 2026
12	Richard Alan	Indirect evidence	Dewsbury, United KingdomHQ checked Sep 7, 2026	51-200	74 contacts →
	“Established in 1970, the West Yorkshire-based Richard Alan Group is a portfolio of businesses providing high-quality Engineering Design, Manufacture, Installation and Servicing to…” Source: company website · checked Sep 7, 2026
13	Jacopa Limited	Indirect evidence	West Bromwich, United KingdomHQ checked Sep 7, 2026	51-200	73 contacts →
	“Many of the best known, most respected and reliable brand names in the wastewater industry are part of Jacopa's heritage.” Source: company website · checked Sep 7, 2026
14	Sayvol Environmental And Building Services Limited	Strong evidence	Kettering, United KingdomHQ checked Sep 7, 2026	51-200	57 contacts →
	“Independent Water Treatment & Water/Air Hygiene company with National coverage.” Source: company website · checked Sep 7, 2026
15	Fileder Filter Systems	Indirect evidence	Maidstone, United KingdomHQ checked Sep 7, 2026	51-200	53 contacts →
	“In short, we’re 'easy to deal with'.” Source: company website · checked Sep 7, 2026
16	Advanced Water Technologies	Strong evidence	Warrington, United KingdomHQ checked Sep 7, 2026	51-200	52 contacts →
	“Welcome to Advanced Water Technologies: A dedicated water treatment & hygiene specialists focused on providing optimum solutions across a vast array of services, chemicals…” Source: company website · checked Sep 7, 2026
17	Guardian Water Treatment Marlowe Environmental Services	Strong evidence	Basildon, United KingdomHQ checked Sep 7, 2026	51-200	50 contacts →
	“Guardian part of Marlowe Environmental Services, delivers a range of water treatment and air quality services, allowing the systems that rely on these elements to work effectively…” Source: company website · checked Sep 7, 2026
18	Hydrotec Water Treatment Specialists	Strong evidence	High Wycombe, United KingdomHQ checked Sep 7, 2026	51-200	50 contacts →
	“Hydrotec is the UK’s leading company in the design and manufacture of water treatment products for the building services industry.” Source: company website · checked Sep 7, 2026
19	T-T Pumps LTD	Indirect evidence	Woore, United KingdomHQ checked Sep 7, 2026	51-200	49 contacts →
	“Established in 1959, T-T started out as a general engineering company before growing to consist of 6 divisions – T-T Pumps, T-T Controls and Automation, T-T Flow Valves, T-T…” Source: company website · checked Sep 7, 2026
20	Atac Solutions LTD	Indirect evidence	Maidstone, United KingdomHQ checked Sep 7, 2026	11-50	44 contacts →
	“ATAC Solutions Ltd is a leading UK environmental services company specialising in wastewater services and wastewater equipment on a capital purchase or hire basis.” Source: company website · checked Sep 7, 2026
21	Bluewater BIO	Strong evidence	London, United KingdomHQ checked Sep 7, 2026	51-200	43 contacts →
	“Bluewater Bio is an award winning global leader in sustainable water and wastewater treatment.” Source: company website · checked Sep 7, 2026
22	Billi UK	Partial evidence	Wolverhampton, United KingdomHQ checked Sep 7, 2026	51-200	40 contacts →
	“At Billi, we design and manufacture a range of energy efficient filtered water systems that offer our customers the very best in innovation, superior performance and reliability.” Source: company website · checked Sep 7, 2026
23	Hydro Industries Limited	Partial evidence	London, United KingdomHQ checked Sep 7, 2026	51-200	40 contacts →
	“Hydro Industries.generating clean water Clean Water is a limited natural resource essential for life and economic growth.” Source: company website · checked Sep 7, 2026
24	Water Treatment Products LTD	Strong evidence	Blaenavon, United KingdomHQ checked Sep 7, 2026	51-200	40 contacts →
	“Water Treatment Products Ltd, established in formulate and manufacture speciality chemicals for a wide range of water treatment companies and applications.” Source: company website · checked Sep 7, 2026
25	BWA Water Additives	Partial evidence	M32 0tb, United KingdomHQ checked Sep 7, 2026	51-200	38 contacts →
	“BWA is a technology-led specialty chemicals company who provides sustainable water management solutions to increase our customers’ competitive advantage.” Source: company website · checked Sep 7, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: water treatment companies. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names water treatment companies.
Partial evidence: Its own public description names part of water treatment companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name water treatment companies. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 25 of 387 water treatment companies based in the United Kingdom

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Water treatment companies based in the United Kingdom at a glance

As of Sep 7, 2026

42.3%Verified-email coverage

5.4%Mobile-number coverage

14.0Average contacts per company

11-50Median size (employees)

4.7%Largest-city concentration · London

Sep 7, 2026Page data refreshed

Companies by employee count

1-10

185

11-50

130

51-200

201-500

501-1,000

1,001-5,000

10001+

Freshness & accuracy

How recently the business emails on this list were verified

Email last verified

2,0500–30

23831–60

161–90

190–180

2180+

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among water treatment companies, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies: Companies headquartered in the United Kingdom whose own description of what they do matches “water treatment companies”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search: RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names water treatment companies), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude: Companies whose own description does not clearly place them among water treatment companies, and records with no verified work email. Companies headquartered outside United Kingdom are excluded even when they keep an office there.
Match quality: In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking: Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification: Every listed company carries at least one verified work email, 2,292 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh: This page's figures were pulled from the company graph on September 7, 2026. Lists refresh periodically as the graph is re-checked.
Corrections: Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names water treatment companies, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many water treatment companies are there based in the United Kingdom?

RevenueBase identified 387 water treatment companies headquartered in the United Kingdom as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

RSE, headquartered in Inverness Highlands, tops this list with the largest team on record.

Which city has the most water treatment companies?

London leads with 18 headquartered companies, followed by Warrington (6) and Bristol (5).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 2,292 verified decision-maker contacts tracked across these 387 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 7, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.