Company lists · Data refreshed September 2026

Top 25 Wastewater treatment plant construction companies based in the United Kingdom

RevenueBase identified 224 wastewater treatment plant construction companies headquartered in the United Kingdom as of September 2026 and tracks 4,875 professional contacts across them, including 1,929 with verified work emails. London is the largest hub.

This list covers wastewater treatment plant construction 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 19, 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 19, 2026 86% judged on-target in blind review
224Companies
4,875Contacts tracked
1,929Verified emails
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The 25 largest wastewater treatment plant construction companies based in the United Kingdom

Ranked by team size
Top 25 of 224 wastewater treatment plant construction companies based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 19, 2026. RevenueBase Smart Search rates how each company's information relates to wastewater treatment plant construction 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.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Partial evidenceStockport, United KingdomHQ checked Sep 19, 20261,001-5,000879 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 19, 2026
2Strong evidencePreston, United KingdomHQ checked Sep 19, 2026201-500193 contacts →

Strong evidence

“Eric Wright Water Ltd (part of the Eric Wright Group) is a multi-disciplinary engineering and construction company working in the water and wastewater industry.”

Source: RevenueBase Database · checked Sep 19, 2026
3Indirect evidenceWorcester, United KingdomHQ checked Sep 19, 2026201-500178 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 19, 2026
4Partial evidenceSurrey, United KingdomHQ checked Sep 19, 2026501-1,000178 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 19, 2026
5Indirect evidenceCoventry, United KingdomHQ checked Sep 19, 20261,001-5,000137 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 19, 2026
6Strong evidenceBirmingham, United KingdomHQ checked Sep 19, 202651-200113 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 19, 2026
7Indirect evidenceHorsham, United KingdomHQ checked Sep 19, 202651-20088 contacts →

Indirect evidence

“ERG is a specialist environmental engineering contractor.”

Source: RevenueBase Database · checked Sep 19, 2026
8Partial evidenceUnited Kingdom & Ireland, United KingdomHQ checked Sep 19, 2026201-50076 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 19, 2026
9Partial evidenceAlfreton, United KingdomHQ checked Sep 19, 2026201-50075 contacts →

Partial evidence

“Envirogen Group is a global leader in industrial water treatment and process filtration solutions.”

Source: RevenueBase Database · checked Sep 19, 2026
10Partial evidenceMonmouth, United KingdomHQ checked Sep 19, 202651-20075 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 19, 2026
11Indirect evidenceDewsbury, United KingdomHQ checked Sep 19, 202651-20074 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 19, 2026
12Partial evidenceWest Bromwich, United KingdomHQ checked Sep 19, 202651-20073 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 19, 2026
13Indirect evidenceEnfield, United KingdomHQ checked Sep 19, 202651-20070 contacts →

Indirect evidence

“Welcome to Gel Engineering.”

Source: RevenueBase Database · checked Sep 19, 2026
14Partial evidenceStepps, United KingdomHQ checked Sep 19, 2026201-50058 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 19, 2026
15Partial evidenceMaghera, United KingdomHQ checked Sep 19, 202651-20049 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 19, 2026
16Indirect evidenceWoore, United KingdomHQ checked Sep 19, 202651-20049 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 19, 2026
17Indirect evidenceChippenham, United KingdomHQ checked Sep 19, 202651-20048 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 19, 2026
18Partial evidenceHuntingdon, United KingdomHQ checked Sep 19, 202651-20047 contacts →

Partial evidence

“Alpheus is one of the UK’s leading wastewater management and environmental solutions providers.”

Source: RevenueBase Database · checked Sep 19, 2026
19Partial evidencePortland, United KingdomHQ checked Sep 19, 2026201-50045 contacts →

Partial 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 19, 2026
20Partial evidenceMaidstone, United KingdomHQ checked Sep 19, 202611-5044 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 19, 2026
21Strong evidenceNorthamptonshire, United KingdomHQ checked Sep 19, 202651-20033 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 19, 2026
22Partial evidenceGloucester, United KingdomHQ checked Sep 19, 202611-5032 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 19, 2026
23Partial evidenceRuncorn, United KingdomHQ checked Sep 19, 202611-5032 contacts →

Partial evidence

“Tertiary water treatment specialist.”

Source: RevenueBase Database · checked Sep 19, 2026
24Indirect evidenceBromsgrove, United KingdomHQ checked Sep 19, 202651-20031 contacts →

Indirect evidence

“Watertight Management has established itself as a leader in the provision of Clean and Waste water management services.”

Source: RevenueBase Database · checked Sep 19, 2026
25Indirect evidenceNottingham, United KingdomHQ checked Sep 19, 202651-20029 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 19, 2026

Showing 25 of 224 wastewater treatment plant construction companies based in the United Kingdom

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Wastewater treatment plant construction companies based in the United Kingdom at a glance

As of Sep 19, 2026
39.6%Verified-email coverage
21.8Average contacts per company
11-50Median size (employees)
4.0%Largest-city concentration · London
Sep 19, 2026Page data refreshed

Companies by employee count

1-10
89
11-50
89
51-200
29
201-500
7
501-1,000
4
1,001-5,000
3

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 224 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 construction 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 plant construction 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 plant construction 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 plant construction 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, 1,929 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 19, 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 construction 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 plant construction companies are there based in the United Kingdom?

RevenueBase identified 224 wastewater treatment plant construction 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?

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

Which city has the most wastewater treatment plant construction companies?

London leads with 9 headquartered companies, followed by Newry (6) and Coventry (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 1,929 verified decision-maker contacts tracked across these 224 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 19, 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.