Northpoint has secured Drinking Water Inspectorate (DWI) approval for submersion coating applications, giving AMP8 delivery teams another verified option for protecting permanently immersed potable water assets.
DWI approval in this case covers coatings applied to assets that remain permanently submerged in the drinking water network. These systems must maintain compliance and performance under continuous immersion, meeting requirements for corrosion protection and water quality.
For asset owners and specifying engineers, submerged applications present a greater challenge than coatings used in environments where exposure conditions change over time, and performance depends on more than material selection alone.
The suitability of the system, the application process and the controls used during application all influence long-term reliability, especially where assets will operate for extended periods with limited access for inspection or maintenance.
Why submerged drinking water assets are difficult to coat
Permanent immersion creates a more challenging coating environment because the system must maintain adhesion, corrosion protection, and compliance while continuously exposed to treated water. With limited opportunity for inspection or repair once an asset is in service, coating selection and application quality become critical.
Corrosion prevention depends heavily on the quality of the coating barrier and the integrity of the bond between the coating and substrate. This makes surface preparation a critical stage, with factors such as contamination control, surface profile, and application conditions influencing final performance.
Once an underwater asset is commissioned, access for inspection, repair or recoating can be difficult and disruptive. For these reasons, selecting a coating system and application process that are appropriate for the operating conditions is key to whole-life asset planning.
Fusion-bonded epoxy (FBE) is widely used for applications requiring durable corrosion protection. The process uses heat to melt and bond epoxy powder directly to prepared metal surfaces, creating a continuous protective layer. Performance depends on correct specification, process controls, and quality assurance throughout the process.
What the DWI approval covers
Northpoint’s DWI approval covers the application of its fusion-bonded epoxy (FBE) coating system to assets that remain permanently submerged within the drinking water network. It confirms the coating application has been assessed for this specific potable water environment, rather than for general corrosion protection alone.
For engineers assessing coating partners, the approval provides an additional point of verification alongside project-specific requirements and asset operating conditions.
For specifiers reviewing DWI-approved coatings, it is important to confirm that the approval scope matches the intended application. Approval status should be considered alongside factors including coating system design, preparation requirements, application controls, and inspection procedures.
What it means for AMP8 delivery
The AMP8 water industry investment programme is expected to place greater emphasis on specifying proven coating systems for submerged drinking water assets. Between 2025 and 2030, utilities will deliver a significant programme of asset renewal. With an estimated £88–104 billion of investment across the sector, coating specification is likely to receive increased scrutiny alongside wider requirements for quality, compliance, and whole-life asset performance.
For engineers and procurement teams, selecting a potable water coating is only part of the process. Verifying that the approval scope matches the intended application, and that the applicator can demonstrate consistent preparation, application, and quality assurance, can help reduce specification risk before installation begins.
As programmes move from design into delivery, early confirmation of coating requirements may also help avoid delays during procurement and construction. This is particularly relevant for permanently submerged assets, where remedial work after commissioning can be costly and operationally disruptive.
Northpoint’s recently announced approval adds another application capability available to utilities and contractors specifying submerged potable water assets for AMP8 water infrastructure projects.
How specifiers should check a coating partner’s approval
DWI approval should be assessed against the intended application rather than treated as a general indication of suitability. Specifiers should confirm what the approval covers, the conditions under which it applies, and whether the approved coating system matches the project’s operating environment.
Approval status is only one part of the assessment. Coating performance also depends on correct surface preparation, controlled application, inspection, and quality assurance throughout the process.
Procurement teams should also consider an applicator’s facilities, experience with comparable assets, and ability to demonstrate consistent processes. Reviewing approval scope alongside application controls and quality management helps ensure the selected coating system is appropriate for the asset’s long-term operating conditions.
Northpoint applies deep fluid bed fusion-bonded epoxy (FBE) coatings from its Dukinfield facility and has operated since 1976. The company recently secured Drinking Water Inspectorate approval for submersion applications, adding to the range of approved coating services available for permanently immersed potable water assets.
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