Company lists · Data refreshed September 2026

Top 25 Wastewater treatment plant builders based in the United Kingdom

Name: Wastewater treatment plant builders based in the United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 22, 2026 189 companies tracked

RevenueBase identified 189 wastewater treatment plant builders headquartered in the United Kingdom as of September 2026 and tracks 4,167 professional contacts across them, including 1,684 with verified work emails. Coventry is the largest hub.

This list covers wastewater treatment plant builders 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 22, 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 22, 2026 86% judged on-target in blind review

189Companies

4,167Contacts tracked

1,684Verified emails

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The 25 largest wastewater treatment plant builders based in the United Kingdom

Ranked by team size

Top 25 of 189 wastewater treatment plant builders based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 22, 2026. RevenueBase Smart Search rates how each company's information relates to wastewater treatment plant builders: 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	MWH Treatment	Partial evidence	Stockport, United KingdomHQ checked Sep 22, 2026	1,001-5,000	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 22, 2026
2	Onsite Central Limited	Indirect evidence	Worcester, United KingdomHQ checked Sep 22, 2026	201-500	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 22, 2026
3	Biwater	Partial evidence	Surrey, United KingdomHQ checked Sep 22, 2026	501-1,000	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 22, 2026
4	Severn Trent Services	Indirect evidence	Coventry, United KingdomHQ checked Sep 22, 2026	1,001-5,000	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 22, 2026
5	TES Group	Indirect evidence	Cookstown, United KingdomHQ checked Sep 22, 2026	51-200	116 contacts →
	Indirect evidence “TES are Mechanical & Electrical Specialists, working to the highest standard of engineering excellence.” Source: RevenueBase Database · checked Sep 22, 2026
6	Enpure	Strong evidence	Birmingham, United KingdomHQ checked Sep 22, 2026	51-200	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 22, 2026
7	Siltbuster LTD	Partial evidence	Monmouth, United KingdomHQ checked Sep 22, 2026	51-200	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 22, 2026
8	Richard Alan	Indirect evidence	Dewsbury, United KingdomHQ checked Sep 22, 2026	51-200	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 22, 2026
9	Jacopa Limited	Partial evidence	West Bromwich, United KingdomHQ checked Sep 22, 2026	51-200	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 22, 2026
10	GEL Engineering	Indirect evidence	Enfield, United KingdomHQ checked Sep 22, 2026	51-200	70 contacts →
	Indirect evidence “Welcome to Gel Engineering.” Source: RevenueBase Database · checked Sep 22, 2026
11	ESD Joint Venture	Partial evidence	Stepps, United KingdomHQ checked Sep 22, 2026	201-500	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 22, 2026
12	Hydrotec Water Treatment Specialists	Partial evidence	High Wycombe, United KingdomHQ checked Sep 22, 2026	51-200	50 contacts →
	Partial evidence “Hydrotec is the UK’s leading company in the design and manufacture of water treatment products for the building services industry.” Source: RevenueBase Database · checked Sep 22, 2026
13	BSG	Partial evidence	Maghera, United KingdomHQ checked Sep 22, 2026	51-200	49 contacts →
	Partial evidence “With over 40 year’s industry experience, we are a leading engineering contractor with specialist expertise in the water and wastewater sector.” Source: RevenueBase Database · checked Sep 22, 2026
14	T-T Pumps LTD	Indirect evidence	Woore, United KingdomHQ checked Sep 22, 2026	51-200	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 22, 2026
15	Huber Technology UK & Ireland	Indirect evidence	Chippenham, United KingdomHQ checked Sep 22, 2026	51-200	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 22, 2026
16	Colloide	Partial evidence	Tyrone, United KingdomHQ checked Sep 22, 2026	51-200	46 contacts →
	Partial evidence “Colloide Engineering Systems are a process engineering company, delivering tailored solutions for clients across many industries including Water and Wastewater, Food & Drink…” Source: RevenueBase Database · checked Sep 22, 2026
17	Hydro International UK Wastewater Services	Indirect evidence	Portland, United KingdomHQ checked Sep 22, 2026	201-500	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 22, 2026
18	Atac Solutions LTD	Partial evidence	Maidstone, United KingdomHQ checked Sep 22, 2026	11-50	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 22, 2026
19	Marsh Industries LTD	Strong evidence	Northamptonshire, United KingdomHQ checked Sep 22, 2026	51-200	33 contacts →
	Strong evidence “Marsh Industries delivers world-class water/wastewater treatment products and solutions to the domestic, commercial, agricultural and leisure sectors from its UK manufacturing…” Source: RevenueBase Database · checked Sep 22, 2026
20	Wcsee Wastewater Marlowe Environmental Services	Partial evidence	Gloucester, United KingdomHQ checked Sep 22, 2026	11-50	32 contacts →
	Partial evidence “At WCSEE we collaborate closely with our clients to design and deliver reliable, robust, and future-proofed wastewater systems tailored to site specific requirements.” Source: RevenueBase Database · checked Sep 22, 2026
21	Rhames	Indirect evidence	Nottingham, United KingdomHQ checked Sep 22, 2026	51-200	29 contacts →
	Indirect evidence “rhames are innovators within the Manufacturing & Engineering Services sector specialising in Pharmaceutical, Petrochemical and Utilities industries with key representations within…” Source: RevenueBase Database · checked Sep 22, 2026
22	Retroflo	Indirect evidence	Seaham, United KingdomHQ checked Sep 22, 2026	11-50	25 contacts →
	Indirect evidence “Based in the North East of England, Retroflo Ltd are an Electrical and Mechanical contractor whose main activities are focused in the water industry.” Source: RevenueBase Database · checked Sep 22, 2026
23	Smoothflow Water Treatment & Commissioning	Partial evidence	Rickmansworth, United KingdomHQ checked Sep 22, 2026	51-200	23 contacts →
	Partial evidence “Smoothflow have been setting benchmark standards since our inception in 1992 and has grown into one of the most highly regarded providers of water treatment, commissioning &…” Source: RevenueBase Database · checked Sep 22, 2026
24	Acwa Services Limited	Strong evidence	Skipton, United KingdomHQ checked Sep 22, 2026	11-50	22 contacts →
	Strong evidence “ACWA Services Limited is a Municipal and Industrial Water and Wastewater Treatment company located in Skipton, United Kingdom.” Source: RevenueBase Database · checked Sep 22, 2026
25	KEE	Strong evidence	Aylesbury, United KingdomHQ checked Sep 22, 2026	51-200	21 contacts →
	Strong evidence “KEE KEE is a globally recognised brand operating within in the industrial, commercial and domestic wastewater treatment industries.” Source: RevenueBase Database · checked Sep 22, 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: wastewater treatment plant builders. 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 plant builders.
Partial evidence: Its own public description names part of wastewater treatment plant builders, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name wastewater treatment plant builders. 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 189 wastewater treatment plant builders based in the United Kingdom

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Wastewater treatment plant builders based in the United Kingdom at a glance

As of Sep 22, 2026

40.4%Verified-email coverage

22.0Average contacts per company

11-50Median size (employees)

3.2%Largest-city concentration · Coventry

Sep 22, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

201-500

501-1,000

1,001-5,000

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 189 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 plant builders, 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 plant builders”. 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 plant builders), 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 plant builders, 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, 1,684 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 22, 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 plant builders, 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 plant builders are there based in the United Kingdom?

RevenueBase identified 189 wastewater treatment plant builders 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?

MWH Treatment, headquartered in Stockport, tops this list with the largest team on record.

Which city has the most wastewater treatment plant builders?

Coventry leads with 6 headquartered companies, followed by London (6) and Newry (6).

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 1,684 verified decision-maker contacts tracked across these 189 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 22, 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.