The water industry is on the brink of a significant transformation as expenditure to reduce nutrients in UK rivers is set to double during the 2025-2030 investment period. With plans for around 900 phosphorus removal projects in England and Wales, the urgency for effective solutions is palpable. Duncan Wildgoose, business development manager and head of wastewater at Xylem UK, highlights that while there have been substantial reductions in sewage effluent phosphorus loads over the last quarter-century due to wastewater treatment upgrades, the landscape is changing.
Tightening consents driven by legislative frameworks like the Water Industry National Environment Programme (WINEP), the Environment Act 21, and Water Environment Regulations are pushing utilities to seek innovative technologies capable of achieving unprecedented phosphorus removal levels. As the next asset management period (AMP8) looms, consents of under 0.4 mg/l TP are becoming the norm. This shift, coupled with the pressing need for net-zero emissions, means that delivery teams face a daunting challenge, especially amidst expected financial constraints.
However, there’s a silver lining. Proven technologies are already making waves in the industry, with ballasted clarification emerging as a game-changer. This technique, developed in North America and introduced to the UK about five years ago, is proving to be not only sustainable but also cost-effective. Ballasted clarification employs dense materials, like magnetite, to enhance biological or chemical flocs, thereby improving the settling of suspended solids in wastewater. The result? A process that can handle wastewater ten times faster than traditional clarifiers, all while operating on a smaller footprint.
This technology is gaining traction among water companies, particularly for medium to large treatment sites where cost efficiency is critical. During AMP7, Xylem collaborated with four UK utilities to install 14 ballasted clarification systems, including the largest application of this technology globally at a major facility serving a large city. Collectively, these installations can treat up to one-and-a-half billion cubic meters of wastewater daily, achieving phosphorus levels as low as 0.15 mg/l. This is a monumental step towards healthier rivers and ecosystems.
Moreover, the ability to reuse existing assets—like repurposed rapid gravity filters—adds another layer of sustainability. For water company planners eyeing phosphorus removal solutions for AMP8, now is the opportune moment to engage with suppliers about technology availability and cost implications. Exploring options that integrate into existing infrastructure can significantly reduce expenses and environmental footprints.
As the sector seeks to lessen its reliance on chemicals like ferric for phosphorus removal, ballasted clarification shines even brighter. It can potentially reduce ferric use by 20-30%, all while minimizing operator intervention and manual cleaning. This not only translates to environmental benefits but also substantial financial savings over a 20-year lifespan.
Looking ahead, Xylem envisions a future where investment in phosphorus recovery technologies becomes commonplace. Cities like Dublin and Madrid, along with successful initiatives in the U.S., demonstrate the potential of converting phosphorus into sustainable fertilizers. Yet, in the UK, the adoption of phosphorus recovery has lagged, often dismissed as non-viable or cost-ineffective. This presents a unique opportunity for UK water companies to lead the charge towards a circular economy in phosphorus management, setting a precedent for sustainable practices that could redefine the industry.
As we stand at this crossroads, the decisions made today will shape the future of water management, making it imperative for stakeholders to embrace innovation and collaboration. The time for action is now; the health of our rivers and ecosystems depends on it.
