Steel Fabrication for the Water and Wastewater Treatment Sector
Water industry fabrication is more tightly regulated than most sectors. The rules are strict, the documentation requirements are extensive and the consequences of non-compliance are direct: work that does not conform to the relevant water authority’s regulations gets rejected. Correction is at the fabricator’s cost.
We have fabricated stainless steel and galvanised steelwork for wastewater treatment works, pumping stations and maintenance platforms for over a decade. End clients include Severn Trent, Yorkshire Water and United Utilities. We work as a fabrication subcontractor to main contractors, handling design, fabrication, full material traceability and quality documentation. Installation is handled by the main contractor on site.
Everything we produce for the water sector is designed and fabricated under BS EN 1090 EXC2, the structural steel standard that’s a non-negotiable requirement for water authority structural work and to the specific regulations of the relevant authority before we start, not after.
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What We Fabricate
- Weir plates
- Baffle curtains, including large modular assemblies designed for assembly inside the tank on site
- Cat ladders and access ladders, including tall installations with rest platforms
- Rest platforms and access platforms
- Handrail systems, including bespoke configurations for restricted access
- Flooring and walkway sections
- Structural steelwork for treatment works
- Pipework supports
Why Water Authority Regulations Matter and Why Getting Them First Is Not Optional
Every major water authority in the UK runs to its own set of standards and approved components lists. Severn Trent, Yorkshire Water, United Utilities and Thames Water each specify what materials are acceptable, what connections and fixings are approved, and what documentation is required. The differences are specific and sometimes surprising.
“One authority will accept a connector and another one won’t, even something as simple as handrail connectors.”
A fabrication that is technically sound but uses a component not on the relevant authority’s approved list can be rejected outright. The correction is the fabricator’s responsibility and cost.
“If the work we do does not conform to that authority’s regulations, the work can be rejected and we will have to correct at our own cost.”
The only way to avoid that outcome is to obtain the relevant authority’s regulations before design begins and build them into the specification from the start.
“We always ensure we get the regulations that the water authority states before we start the job and build it into the design.”
This is not an unusual standard of care. It is the minimum required to work reliably in this sector. We have seen what happens when it is not done.
Material Selection, 316 Stainless Steel and Galvanised Steel
Material choice in water industry fabrication is determined by environment, not preference. The rule is straightforward.
“A lot of the stainless steel products we do is actually in the flow of the water or the wastewater. The galvanised is above ground, doesn’t need the same level of protection.”
Components in direct contact with water or wastewater, such as weir plates, baffle curtains, submerged ladders and platforms, are fabricated in 316 stainless steel. Grade 316 provides the corrosion resistance required for constant exposure to wastewater and its chemical environment. Above-ground structures such as pumping station platforms, where the environment is less aggressive, are fabricated in galvanised steel.
Full Material Traceability, What It Means in Practice
BS EN 1090 EXC2 requires complete material traceability on all structural steelwork. In the water sector, where work is subject to client audit and authority inspection, that traceability has to be real and complete, not a summary or a generalisation.
“We can show them the quote from the material supplier, the purchase order, the delivery note and the material cert.”
For every job, we retain the full chain of custody: supplier quote, purchase order, delivery note, material test certificate, welder identification, welding machine records and consumables records. If any part of the job is audited, during delivery, on site or retrospectively, we can evidence every piece of steel and every weld.
BS EN 1090 EXC2 is a mandatory requirement for structural steelwork on water authority sites. A fabricator without this accreditation cannot legally supply structural steelwork to the water sector. The accreditation is verifiable, ask for the certificate number. |
How We Got Here and Why the Accreditation Was Not Optional
We obtained BS EN 1090 EXC2 after losing work to a competitor because we did not hold it. A design engineer we worked with regularly had a water sector job that required it, the site mandated it. He had to use a different fabricator. The work was ours to lose and we lost it.
“We lost work ten years ago from not having BS EN 1090 EXC2. A design engineer I used had work for us but the site needed it and he had to use a rival company. That’s when we decided to get it.”
Obtaining BS EN 1090 EXC2 is not a quick process. It requires certified welding procedures, coded welders, calibrated equipment, approved supplier lists and a documented quality management system, all independently assessed. It took over a year. We committed to it because the sector is better policed than most.
“It’s better policed and the rules and regulations you have to work to are more strict.”
We hold the accreditation. It covers our full fabrication process and applies to every water sector job we produce.
How It Works
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Main contractor approaches us with a project requirement, typically with a site survey capturing dimensions and site-specific conditions.
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We obtain the specific regulations for the relevant water authority (Severn Trent, Yorkshire Water, United Utilities, or others). Each authority has different standards and approved components lists.
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Design is produced in full compliance with the water authority’s regulations and BS EN 1090 EXC2. Nothing is assumed or carried over from a previous authority’s job.
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Design submitted to the contractor and end client for formal approval. Fabrication does not begin until approval is confirmed.
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Materials ordered from approved suppliers. Material certificates obtained and logged at point of order.
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Fabrication carried out with full material traceability: steel cert, purchase order, delivery note, welder ID, welding machine, consumables all recorded per job.
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Quality checks carried out against specification before despatch.
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Components delivered to the main contractor for installation on site. Full traceability documentation accompanies the delivery.
What Makes Advantage Engineering Different
BS EN 1090 EXC2, held and evidenced
A non-negotiable requirement for water sector structural steelwork. We invested over a year obtaining this accreditation. The certificate number is available on request. Not all fabricators hold it.
Water authority regulations built in from the start
We obtain the specific regulations for the relevant authority before design begins, not during or after. What is approved by Severn Trent may not be approved by Yorkshire Water. We work to the right rulebook for each job.
Design approval before fabrication
Nothing gets cut until the contractor and end client have formally signed off the design. Changes at fabrication stage cost everyone time and money.
Complete material traceability
Supplier quote, purchase order, delivery note, material cert, welder ID, machine records, consumables records, all retained per job. If audited, we can evidence every piece of steel and every weld.
Modular design for restricted site access
Large assemblies are designed in sections from the outset, sized to transport through access constraints and bolt together on site. The design problem is solved before fabrication, not on site.
Proven track record with major authorities
Work completed for Severn Trent, Yorkshire Water, and United Utilities. Each has different standards. We have worked to all three.
Project Examples
12-Metre Cat Ladder with Rest Platform, United Utilities
Scope: 12-metre stainless steel cat ladder with integrated rest platform
Challenge: Curved chamber wall, standard flat fixing not possible. Pop-up handrail required for manhole cover clearance.
Material: 316 stainless steel throughout
Standard: United Utilities regulations and BS EN 1090 EXC2
A 12-metre cat ladder for a United Utilities chamber presented two non-standard problems that could not be resolved with off-the-shelf components.
The chamber wall was curved. A standard flat fixing frame would not make consistent contact with the wall surface. We designed a framework of rolled box section bars, shaped to follow the curve of the wall and bolted through it, providing a stable rail to which the platform was then fixed. The rolling of the box section was designed and specified before fabrication began, not discovered on site.
The second problem was the manhole cover. The handrail at the top of the ladder had to pass through the cover on entry and exit. A permanent upstand would prevent the cover from closing. We designed a pop-up handrail system: raised and locked in position on entry by one person, retracted flush below the cover on exit.
“The handrail can all be operated by one person.”
Everything fabricated in 316 stainless steel to United Utilities’ standards and BS EN 1090 EXC2. Full material traceability documentation provided.
18m x 6.5m Modular Baffle Curtain, Wastewater Treatment Works
Dimensions: 18 metres wide x 6.5 metres deep
Construction: Stainless steel flat plates supported on stainless steel channels, fully bolted
Method: Fabricated in modular sections, transported to site, assembled inside the tank
An 18-metre by 6.5-metre baffle curtain is not a component that can be fabricated as a single unit and transported to site. The logistics alone make it impossible. The solution is modular design, sections fabricated in the workshop to fit through the access constraints of the site, then assembled inside the tank.
We fabricated the curtain in stainless steel flat plates supported on stainless steel channels. Every section was designed to fit together precisely. Every bolt hole was in the right place. On site, the sections were assembled inside the tank in sequence.
“It went together like a jigsaw.”
That outcome, a large, complex structure assembling cleanly on site without adjustment, is the result of the design work done in the workshop before fabrication begins, not something that happens by chance.
Capabilities
Primary material, submerged |
316 stainless steel (in-flow and submerged components) |
Primary material, above ground |
Galvanised steel (pumping station platforms and above-ground structures) |
Components fabricated |
Weir plates, baffle curtains, cat ladders, rest platforms, access platforms, handrail systems, flooring, structural steelwork, pipework supports |
Large-format capability |
18m x 6.5m modular assemblies; 12m height cat ladders with rest platforms |
Modular construction |
Large items designed for modular assembly on site, sections bolt together; sized to transport through restricted access |
Accreditation |
BS EN 1090 EXC2 (Cert No: 20203, Exc Class 2), mandatory for water sector structural steelwork |
Material traceability |
Full chain of custody: supplier quote, purchase order, delivery note, material cert, welder ID, machine records, consumables records, retained per job |
Water authorities worked with |
Severn Trent, Yorkshire Water, United Utilities |
Role on projects |
Fabrication subcontractor to main contractors. Main contractors handle site installation. |
Design approval |
All designs formally approved by contractor and end client before fabrication commences |
FAQ’s
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Yes, Cert No: 20203, Exc Class 2. This accreditation is a mandatory requirement for structural steelwork on water authority sites. It covers our certified welding procedures, coded welders, calibrated equipment, approved supplier lists, and full material traceability system. The certificate is available on request.
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Yes. We work to the regulations of the relevant water authority for each project, whether that is Severn Trent, Yorkshire Water, United Utilities, or others. We obtain those regulations before design begins, not after. The difference between what one authority will accept and another will not can be as specific as individual handrail connector types.
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316 stainless steel for anything in contact with water or wastewater, it provides the corrosion resistance required for constant exposure in that environment. Galvanised steel for above-ground structures such as pumping station platforms where the environment is less aggressive. Material selection is confirmed at design stage and documented through material certificates.
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No, we are a fabrication subcontractor. Our main contractor clients handle installation. We provide complete fabricated components with full material traceability documentation, designed and detailed to make site installation straightforward.
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Yes. Our largest completed water sector project to date is an 18m x 6.5m modular baffle curtain system. We have also completed a 12-metre cat ladder with curved wall fixings, integrated rest platform, and a pop-up flush manhole handrail. Complex details are designed in the workshop, the goal is that nothing is a surprise on site.
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For every job: supplier quote, purchase order, delivery note, material test certificate, welder identification, welding machine records, and consumables records. If the job is audited at any point, we can evidence every piece of steel and every weld back to its source.