– How Glanua is shaping the future of bio-resources and water infrastructure
With an international order book outperforming forecasts and staff headcount heading towards 1,000, Glanua’s trajectory is exceeding all initial targets. ROBBIE COUSINS catches up with Group Managing Director Karl Zimmerer to discuss how the company is bridging the engineering skills gap, expanding into mainland Europe and the USA, and redefining sustainable water and wastewater management.
Karl Zimmerer
When I last interviewed Karl Zimmerer in 2024, we discussed Glanua’s growth trajectory, having established a strong and respected foothold in the water, wastewater and industrial services sectors. Reassessing the landscape nearly two years on, the pace of momentum has not merely been sustained; it has accelerated significantly. Driven by a combination of strategic acquisitions, an international recruitment network, bespoke leadership development and an unwavering commitment to treating sustainability as a primary commercial advantage, Glanua is rapidly scaling its operations across Ireland, the United Kingdom, and continental Europe, with a new office location opening soon in the USA.
In a sector undergoing intense development and transformation – shaped by tightening environmental directives, rising infrastructure demands and pressing net-zero targets – Glanua has positioned itself in that market at the forefront of modern environmental solutions. By expanding its operational footprint and pioneering advanced capabilities in sustainable bio-resource management, the company is proving that sustainable engineering can serve as a catalyst for long-term commercial growth.
Redefining scale and strategic growth
Glanua’s expansion strategy has evolved dynamically to keep pace with fast-moving market demands across both municipal and industrial sectors. Supported by a robust strategic financing partnership with Rabobank, the group has enhanced its original organic growth plans through targeted, high-impact acquisitions in key high-growth regions and specialised sectors.
Karl Zimmerer opens by saying, “Our strategy internally has always been very well-defined, with an enduring focus on being an enhanced, total end-to-end solutions provider for water, wastewater and broader environmental needs,” he explains. “Previously, we had set out a clear organic growth plan targeting approximately €400m over its lifecycle. What has changed is that we have enhanced that organic trajectory by integrating strategic acquisitions in high-growth sectors and regions where immediate opportunities present themselves.”
This multi-faceted growth model has enabled Glanua to deepen its longstanding relationships with major municipal entities, including Uisce Éireann in Ireland, alongside Thames Water, Yorkshire Water and United Utilities in the UK. Simultaneously, the company has aggressively expanded its industrial portfolio, delivering complex engineering and process solutions for leading global brands in the food, beverage, dairy, life sciences and pharmaceutical sectors.
“Supported by our strong strategic financing partnership with Rabobank, we’ve been able to tweak and optimise our approach,” Zimmerer notes. “We are leveraging deep-seated relationships with major municipal entities while simultaneously expanding across the food, beverage, dairy and life science sectors in the UK, Ireland, and now in other European countries.”
The result of this strategic integration is an order book that has expanded well beyond original forecasts, backed by long-term multi-year framework contracts that ensure sustained commercial visibility.
“With the acquisitions we’ve made and the building blocks now in place, our growth trajectory is set well in excess of that original €400m target,” Zimmerer emphasises. “We have secured an extremely healthy multi-sector international order book for the coming years, underpinned by multi-year framework programmes. Now, the operational focus is firmly on scaling, execution and delivering efficiently across every project in our pipeline.”
The bio-resource imperative and the circular economy
A major catalyst in Glanua’s recent evolution is its expanded focus on bioresource management. This has been driven by the strategic acquisitions of Marches Biogas, strengthening the group’s anaerobic digestion and biomethane capabilities and Aqua Operations, enhancing its operations and maintenance expertise. Together, these acquisitions have enabled Glanua to build a fully integrated, end-to-end capability spanning the design, delivery, operation and regulatory management of water, wastewater and bio-resource infrastructure.
As environmental policy across Ireland, the UK and Europe increasingly prioritises the diversion of brown-bin food waste, organic sludges and agricultural feedstocks away from landfills, advanced anaerobic digestion (AD) systems have moved to the centre of modern environmental infrastructure.
“To understand bio-resource management, you have to look at the traditional end-products of wastewater treatment,” Karl Zimmerer says. “In the municipal sector, for instance, a primary byproduct is sewage sludge. Historically in Ireland, much of this went to landfill, with agricultural reuse only occurring under specific treatment conditions.”
Modern AD transforms what was once considered a costly waste burden into a high-value energy resource. By upgrading raw biogas into grid-quality biomethane, facilities can generate clean energy to offset internal power requirements or export biomethane directly into national gas grids.
“A highly effective treatment method for municipal and industrial sludge is anaerobic digestion,” Zimmerer continues. “A major byproduct of the AD process is biogas, which can be upgraded to biomethane. This biomethane can either power the treatment facility directly or be injected into the national gas grid, yielding a significant return on investment when managed correctly.”
Beyond renewable energy production, Glanua’s bio-resource management framework emphasises full resource recovery, including the capture and purification of industrial co-products, such as green CO2 for use in commercial food and beverage manufacturing.
“Through our acquisition of Marches Biogas nearly 12 months ago, alongside our broader operations business over the past two years, we have brought comprehensive operational, maintenance and regulatory oversight capabilities under our roof,” Zimmerer notes. “Furthermore, the environmental landscape is shifting. Diverting brown-bin food waste and agricultural feedstocks away from landfills and into AD plants is a major policy driver in Ireland and the UK.
“We are using sustainability as a genuine competitive advantage,” Zimmerer stresses. “It has to be more than just words or standard accreditations on a wall. We can treat generated biomethane to an exceptionally high standard for grid injection, while capturing co-products like green CO2 for reuse in industrial food production. Whether providing sustainable energy back to heavy industry or supporting data centres seeking alternative power and cooling water solutions, bioresource management seamlessly bridges our core water treatment expertise with circular economy demands.”
Bridging the talent gap
While project pipelines and market opportunities continue to expand, the engineering and construction sectors across Europe face persistent, systemic labour shortages. For Glanua, supporting this growth means investing in people at every stage of their careers, from graduates and apprentices through to future leaders, while selectively recruiting internationally where specialist experience is in short supply. The root causes of today’s engineering skills shortage in Ireland trace back to the severe economic downturn of 2008–2009. During that period, university intake for civil, mechanical and environmental engineering plummeted as career guidance trends shifted students away from the built environment.
“In Ireland, we are still feeling the structural hangover of the 2008–2009 economic crash,” Zimmerer explains. “Back then, guidance counsellors routinely steered school-leavers away from engineering and construction. To put that in perspective, certain local universities that graduated 120 engineers in 2008 saw that figure plunge to just seven by 2014.
“This historic drop in university graduates created a pronounced demographic deficit in today’s labour market, specifically affecting the availability of mid-career professionals with 10 to 15 years of practical industry experience. “Fast forward to today: when the industry desperately needs professionals with around 10 years of experience – the contract managers and senior project leaders who run complex infrastructure projects – that mid-tier demographic simply isn’t there in standard market volumes,” Zimmerer observes. “It is undoubtedly one of our greatest day-to-day challenges, but Glanua is tackling it proactively through internal development and structured international recruitment.”
To solve this challenge, Glanua has established dual pathways: accelerating early-career talent through structured internal advancement while tapping into international markets to recruit. “We invest heavily in our workforce from the time they join us. Alongside a robust graduate programme, we co-developed a structured Future Leaders Programme with an industry-leading external consultancy. We recently completed our first rotation, and the outcomes have been phenomenal.”
To complement its internal leadership pipeline, Glanua looked internationally, undertaking a dedicated recruitment initiative in the Philippines three years ago that successfully integrated 34 engineering professionals into its workforce. Building on that success, the company is currently carrying out a second international recruitment phase to add another 40 engineers to its operations.
“Three years ago, we brought over 34 highly qualified engineering professionals from the Philippines, which proved to be a resounding success across every discipline,” Zimmerer reflects. “We are currently in the middle of a second round, welcoming approximately 40 more professionals in the coming months.”
For Glanua, international recruitment is about much more than filling job roles. The company has developed a comprehensive relocation and integration programme, supporting employees and their families with accommodation, practical relocation assistance and settling into their new communities.
These combined workforce initiatives have laid the groundwork for rapid headcount growth, driving Glanua toward major organisational scale.
“When people choose to move halfway across the world, we have a responsibility to support them. We help them find accommodation and settle into their local communities. We’re incredibly proud of the diverse workforce we’ve built. We have colleagues from over 20 different nationalities, and it really adds to the company culture. Our workforce currently stands at around 650 people, and we expect that to reach 750 by the end of this year, eventually climbing past 1,000 over the next couple of years,” Zimmerer highlights. “Maintaining a strong, cohesive culture as we scale is essential, and our senior executive team remains heavily focused on this.
“One of the things I’m most proud of is seeing people join us early in their careers and grow into leadership roles. Creating those opportunities, while building an inclusive culture where people feel supported and valued, is every bit as important as winning new projects.”
Lisbon engineering hub and European delivery ecosystem
To maintain high technical standards and ensure agility across its European contracts, Glanua established a dedicated engineering hub in Lisbon, Portugal. The centre provides specialised design, BIM process engineering and digital delivery support across all group divisions. Selecting Lisbon was a deliberate move, driven by Portugal’s strong technical education system, high concentration of skilled engineering graduates and close cultural alignment with Irish business practices.
“The Lisbon office is a prime example of solving resource constraints while tapping into exceptional technical talent,” explains Karl Zimmerer. “Glanua has long held deep ties with Portuguese educational institutions and engineering professionals. There is a natural cultural alignment between Irish and Portuguese working styles; the workforce there is mobile, highly qualified, and possesses top-tier technical capabilities.”
Starting as a strategic support office, the Lisbon engineering hub has rapidly expanded into a vital delivery engine for complex multi-disciplinary projects across Europe.
“We currently have over 20 senior engineering professionals across various disciplines operating out of our Lisbon hub, with plans to add another 15 by the end of the year,” Zimmerer notes. “Rather than operating as a localised island, the Lisbon team works as an integrated design and delivery engine for complex projects across Ireland, the UK and mainland Europe.”
The hub’s cross-border scope encompasses diverse, high-value engineering contracts across multiple European markets:
– Pharmaceutical wastewater treatment: High-spec effluent treatment systems designed for complex pharmaceutical manufacturing facilities in Ireland and Europe.
– Industrial food and beverage infrastructure: Advanced process water and biological wastewater management plants in the Netherlands, Germany and Denmark.
– Data centre water solutions: Sustainable, high-capacity cooling water and process treatment solutions tailored for energy-intensive data centres.
– Municipal framework support: Technical engineering and digital modelling supporting major utility investments across Ireland and the UK.
“Right now, they are actively supporting major pharmaceutical wastewater projects, industrial food manufacturing plants in the Netherlands, Germany and Denmark, as well as high-tech water solutions for data centre applications,” Zimmerer adds.
Sustainability as a commercial advantage in an era of changing regulation
As environmental standards tighten across Europe, commercial and industrial enterprises face growing pressure from regulators and consumers. Issues such as emerging chemical contaminants, microplastics removal and carbon neutrality mandates are reshaping how organisations approach water and wastewater management.
Rather than viewing these evolving standards as operational burdens, Glanua positions technical compliance as a central commercial driver that protects clients against future regulatory risks.
“Clients are coming to us asking not just ‘How do we treat this wastewater?’ but ‘How do we meet upcoming 2030 and 2050 environmental mandates while reducing our operational energy spend?’” Zimmerer states. “Industrial clients – whether a dairy processor, a pharmaceutical giant or a municipal utility – are facing unprecedented regulatory shifts. Beyond standard effluent limits, there is a looming wave of strict legislation surrounding microplastics, forever chemicals like PFAS and tight carbon accounting metrics.”
To address these challenges, Glanua incorporates advanced treatment technologies into its designs, including on-site peroxide generation, high-efficiency anaerobic digestion and closed-loop water reuse systems, enabling facilities to significantly lower their environmental footprint while optimising energy consumption.
“By integrating innovative technologies, such as advanced on-site peroxide generation, high-efficiency anaerobic digestion and circular water-reuse systems, we enable clients to solve immediate compliance obligations while de-risking their operations against future regulatory changes,” Zimmerer explains. “Whether we are converting industrial process waste into grid-ready biomethane or delivering closed-loop cooling systems for energy-intensive facilities, our goal remains the same: providing total, future-proofed environmental solutions.”
Looking ahead
Glanua’s ongoing transition from a regional engineering specialist to an international total-solutions provider highlights the impact of clear, disciplined strategy combined with technical innovation. With strong financial backing from Rabobank, a growing workforce targeting 1,000 employees and an expanded operational presence spanning Ireland, the UK, and, more recently, mainland Europe and the USA, the company is well prepared for its next phase of growth.
As industrial sectors and municipal utilities adapt to stricter climate frameworks and resource demands, Karl Zimmerer’s vision ensures Glanua remains a trusted partner in building sustainable, circular infrastructure for the future.