Colloide’s Advance Delivery Model for 154 Dosing Rigs
Scaling Up Chemical Dosing Delivery for Severn Trent Water
Colloide’s work with Severn Trent was not simply a large chemical dosing order. It was a demonstration of what happens when a utility, its supply chain and an engineering partner stop treating every dosing project as a one-off and start building for programme delivery instead.
The project started with an advance order for 115 chemical dosing rigs and grew to 154 units, making it one of the UK’s largest single order for dosing rigs. More importantly, it proved that standardisation, offsite manufacture and advance procurement can give utilities and contractors something the sector increasingly needs: speed, flexibility and delivery certainty without sacrificing engineering quality.
That is where this programme stands out.
A Standardised Approach to Chemical Dosing
Working with Severn Trent, Colloide helped shift chemical dosing away from a bottom-up, site-specific design model toward a standardised suite of rigs designed to suit the vast majority of applications. The target was to meet over 80% of site requirements without modification. In practice, that ambition was exceeded, with only 6% of sites requiring design changes to accommodate specific constraints. That is a strong result in any framework, but especially in one delivered at this scale.
The engineering advantage was clear. Standardisation did not remove flexibility; it created it. The rigs were developed as modular, pre-engineered systems, allowing adaptation around pump configurations, control software and site arrangements while still maintaining a repeatable manufacturing model. The three main modular elements; tanks, dosing kiosks and fill point kiosks, could be connected in different configurations on site, helping contractors and utilities avoid unnecessary redesign while preserving installation practicality.
Delivery Speed and Commercial Value
The delivery benefits were even more significant.
By advance building and holding stock, Colloide cut turnaround time from order to site by 60%. Units could be deployed in as little as two to three weeks, compared with the three to six months often associated with more traditional dosing projects. That speed helped Severn Trent accelerate 80% of its Water Framework Directive programme by year three rather than year five. It also delivered immediate financial value, with the first six projects alone generating more than £1 million in efficiency savings.
The commercial impact was substantial. The programme, valued at £15 million, enabled Severn Trent to lock in pricing and avoid the cost escalation that would have come with piecemeal procurement. Severn Trent put the saving at £2.25 million, all achieved while maintaining flexibility in asset mix and delivery timing despite major AMP7 supply-chain pressures.
Supporting Tier 1 Contractors Through Delivery
For Tier 1 contractors, that kind of programme model changes the job. It means fewer moving parts in the supply chain, shorter lead times for key components, clearer installation windows and less exposure to site delays caused by redesign or unavailable stock. It also means working with a partner that stays engaged past manufacture.
That was another strength of Colloide’s role on this project. Even after novation to delivery partners, Colloide remained involved across the full project lifecycle: site-specific design packs, surveys, delivery, installation, testing, commissioning and O&M documentation. The company coordinated across 14 Tier 1 and Tier 2 partners, adapting to different site policies and contractor requirements while keeping delivery moving. That is more than product supply. It is a delivery model built around collaboration and accountability.
Performance at Scale
The operational performance backed that up. All rigs were manufactured offsite and fully tested before delivery. The programme achieved 100% delivery to agreed cost, 100% compliance with Severn Trent specifications, 100% installation within agreed timescales and no defects affecting completed operation of the final product. During the most intense phase of delivery, 112 of the 154 rigs were delivered in 2024, with 94 of those shipped in just five months from May to October. That level of output is only possible when engineering, manufacturing and programme management are aligned from the start.
154 Advance Dosing Rig Order Recap
Engineering Benefits Delivered
We manufactured all 154 rigs ahead of schedule and stored them free of charge until needed, reducing lead times from six months to two weeks.
Bulk advance procurement locked in prices and avoided AMP7 inflation, producing direct savings for Severn Trent.
Modular design covers both Duty/Duty and Duty/Standby pump configurations, with adaptable controls software, and modification possible onsite when required.
Stock readiness enabled Severn Trent to meet regulatory and investment milestones early, including 80% programme completion by year 3.
All units operated as intended with no defects, streamlining commissioning and ensuring reliability.
The entire project was delivered within budget, with more than £1 million in efficiency savings recorded in the first six sites alone.
Our dedicated 11-acre facility holds up to 300 rigs at any time, ensuring rapid programme agility and eliminating risk and cost of just-in-time logistics.
Designs developed for Severn Trent have now been successfully reused for other projects, laying the foundation for utilities to adapt without duplication of effort.
Delivery Approach and Lessons Learned
Phased Manufacturing: The project ran over four years, with two years of offsite manufacture and testing, followed by two years of on-site installation. This phased approach enabled accelerated timelines and maintained quality standards across all units.
Collaborative Management: Colloide’s proactive engagement across supply chains, contractors, and stakeholders kept delivery on track. During AMP6 and AMP7, we delivered more than 246 chemical dosing rigs to Severn Trent, showing the repeat efficacy of our strategies beyond this single project.
Strategic Standardisation: By moving from bespoke designs to standardised products, we ensured 94% of sites could take a ready-made unit. This cut logistics complexity and simplified installation for contractors.
Efficient Use of Resources: Our modular philosophy enables utilities and contractors to commission additional units or adapt dosing configurations quickly, protecting future investments from stranded asset risk.
Contingency and Prioritisation: Standardisation removes bottlenecks so large volumes can be produced and delivered flexibly according to utility needs.
A Scalable Model for AMP Planning
The Severn Trent programme was not a one-off success. The same standard product philosophy has since been adapted for other major utilities including Welsh Water, Southern Water, Thames Water, Scottish Water and United Utilities. This underlines that this was not simply a project solution, but the basis of a scalable product strategy.
That matters for AMP planning. Utilities do not just need suppliers who can meet a specification. They need engineering partners who can help shape delivery strategies that reduce programme risk, protect budgets and keep options open when priorities change. Contractors need delivery models that can absorb site realities without derailing timelines. Engineers need systems that are proven, adaptable and easier to integrate on live sites.
Colloide’s Severn Trent programme shows what that looks like in practice: standardised where it should be, flexible where it must be, manufactured offsite, deployed quickly and supported through design, installation and commissioning.
Beyond Phosphorus Removal Dosing and The AMP8 Opportunity
And that is only part of the picture. The same thinking can be applied beyond phosphorus removal dosing. Colloide’s wider water capability spans alkalinity dosing, septicity dosing, orthophosphoric acid systems, refurbishment of existing assets, filtration, sludge-related solutions and digital integration, all underpinned by the same focus on engineered standardisation, delivery efficiency and long-term operability.
As the sector moves deeper into AMP8 planning, the lesson is clear, the future of chemical dosing is not slower bespoke delivery dressed up as flexibility. It is smarter programme-led delivery that combines repeatability, speed and technical assurance. Colloide helped prove that with Severn Trent. The next step is helping more utilities, engineers and Tier 1 contractors do the same.
Get in Touch
For utilities, contractors and engineering teams planning the next phase of delivery, Colloide offers a proven model built on standardisation, speed and technical assurance. The team are ready to support projects at scale. Contact Colloide today.
