Company lists · Data refreshed September 2026
Top 25 Wastewater treatment companies based in the United Kingdom
RevenueBase identified 310 wastewater treatment companies headquartered in the United Kingdom as of September 2026 and tracks 11,229 professional contacts across them, including 5,136 with verified work emails. London is the largest hub.
This list covers wastewater 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 16, 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.
The 25 largest wastewater treatment companies based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 5,563 contacts → | ||||
Indirect evidence “Water is wonderful.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 2 | 879 contacts → | ||||
Partial evidence “MWH Treatment is a leading Design and Build non-infrastructure solution provider in the UK water sector, with a water sector heritage dating back to 1820.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 3 | 498 contacts → | ||||
Partial evidence “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: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 4 | 178 contacts → | ||||
Indirect evidence “Originally established in 1977, OnSite is a South Staffordshire Group owned company that has grown through strategic acquisition and organic expansion to become one of the UK's…” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 5 | 178 contacts → | ||||
Partial evidence “Biwater is a world leader in treated water, providing large-scale water and wastewater solutions for clients across the world.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 6 | 137 contacts → | ||||
Indirect evidence “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: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 7 | 113 contacts → | ||||
Strong evidence “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: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 8 | 112 contacts → | ||||
Indirect evidence “AWMS, part of Alumasc Group, is the first joined-up brand in integrated water management.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 9 | 76 contacts → | ||||
Partial evidence “At Nijhuis Saur Industries UK & Ireland our aim is to help our customers realise the value of their water and wastewater.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 10 | 75 contacts → | ||||
Partial evidence “Envirogen Group is a global leader in industrial water treatment and process filtration solutions.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 11 | 75 contacts → | ||||
Partial evidence “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: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 12 | 74 contacts → | ||||
Indirect evidence “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: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 13 | 73 contacts → | ||||
Partial evidence “Many of the best known, most respected and reliable brand names in the wastewater industry are part of Jacopa's heritage.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 14 | 58 contacts → | ||||
Partial evidence “How we manage water and wastewater systems now will be critical for our communities and ecosystems for many generations to come.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 15 | 52 contacts → | ||||
Partial evidence “Welcome to Advanced Water Technologies: A dedicated water treatment & hygiene specialists focused on providing optimum solutions across a vast array of services, chemicals…” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 16 | 51 contacts → | ||||
Indirect evidence “water2business is a leading retailer of water and waste water management solutions to businesses and organisations across England and Scotland.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 17 | 49 contacts → | ||||
Partial evidence “Castle Environmental is a leading supplier of specialist waste treatment, disposal and recycling services.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 18 | 49 contacts → | ||||
Indirect evidence “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: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 19 | 48 contacts → | ||||
Indirect evidence “HUBER Technology was incorporated in the UK in 1993 as a wholly owned subsidiary of Huber SE- Huber UK & Ireland Limited, the manufacturers of the ROTAMAT range of waste water…” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 20 | 47 contacts → | ||||
Partial evidence “Alpheus is one of the UK’s leading wastewater management and environmental solutions providers.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 21 | 45 contacts → | ||||
Indirect evidence “Hydro International, a CRH Company, provides advanced products, services and expertise to help municipal, industrial and construction customers to improve their water management…” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 22 | 44 contacts → | ||||
Partial evidence “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: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 23 | 43 contacts → | ||||
Strong evidence “Bluewater Bio is an award winning global leader in sustainable water and wastewater treatment.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 24 | 40 contacts → | ||||
Indirect evidence “Hydro Industries.generating clean water Clean Water is a limited natural resource essential for life and economic growth.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
| 25 | 40 contacts → | ||||
Partial evidence “Water Treatment Products Ltd, established in formulate and manufacture speciality chemicals for a wide range of water treatment companies and applications.” Source: RevenueBase Database · checked Sep 16, 2026Thanks. The Data Team will review it. | |||||
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: wastewater 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 wastewater treatment companies.
- Partial evidence
- Its own public description names part of wastewater treatment companies, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name wastewater 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 310 wastewater treatment companies based in the United Kingdom
See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 5,136 reachable decision-makers.
Free signup · no credit card
Wastewater treatment companies based in the United Kingdom at a glance
As of Sep 16, 2026Companies by employee count
Email recency for this list is measured worldwide rather than for United Kingdom, so it is reported there. Company counts and contact totals on this page are exact for United Kingdom, over 310 companies.
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 wastewater 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 “wastewater 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 wastewater 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 wastewater 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, 5,136 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 16, 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 wastewater 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 wastewater treatment companies are there based in the United Kingdom?
RevenueBase identified 310 wastewater 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?
Severn Trent, headquartered in Coventry, tops this list with the largest team on record.
Which city has the most wastewater treatment companies?
London leads with 10 headquartered companies, followed by Coventry (6) and Belfast (4).
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 5,136 verified decision-maker contacts tracked across these 310 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 16, 2026.
Ready to reach these companies? Verified emails and direct dials for all 310 wastewater treatment companies based in the United Kingdom. Start with a free account, no credit card.
Download this list →Related lists
Wastewater treatment companies by geography
- Wastewater treatment companies based in Ahmedabad, India
- Wastewater treatment companies based in Chennai, India
- Wastewater treatment companies based in Mumbai, India
- Wastewater treatment companies based in New Delhi, India
- Wastewater treatment companies based in Pune, India
- Wastewater treatment companies based in Argentina
- Wastewater treatment companies based in Australia
- Wastewater treatment companies based in Austria
- Wastewater treatment companies based in Belgium
- Wastewater treatment companies based in Brazil
- Wastewater treatment companies based in Canada
- Wastewater treatment companies based in Chile
Browse the directory
Browse: Companies home · All United Kingdom lists · All Wastewater treatment companies lists · New lists
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.
More company lists
- All company lists
- Lists by location
- Lists A-Z
- New lists
- Wastewater treatment companies based in Ahmedabad, India
- Wastewater treatment companies based in Chennai, India
- Wastewater treatment companies based in Mumbai, India
- Wastewater treatment companies based in New Delhi, India
- Wastewater treatment companies based in Pune, India
- Wastewater treatment companies based in Argentina