Netherlands' most sustainable cast iron drinking water transport pipeline laid in Zevenhuizen

In the Swanladriehoek development area (Zevenhuizen, municipality of Zuidplas), Dunea replaced an existing water transport pipeline with a new one made of ductile iron. In cooperation with Saint-Gobain PAM, a package of measures was chosen that reduces the environmental impact across the entire chain: from production with 100% secondary material and green energy to HVO transport and digital traceability.

The replacement of the transport pipeline is part of the Swanladriehoek area development, where approximately 200 homes and sports facilities are being built. Because the old pipeline would cross the new route, it was decided to replace it over a length of more than 800 meters. By doing so, Dunea links the necessary relocation to a proactive replacement policy; a choice that prevents disruption and duplication of work in the future.

Work started in March; the first section is now in use. The design expressly took account of the environment: 63 of the 67 trees along the route could be preserved and a phased approach was used for the temporary closure of a bicycle path in order to keep detours to a minimum. Trial trenches were dug with an electric excavator.

Material and production: 100% secondary, 60% less CO₂

At the core of the pilot is the use of cast iron pipes (ductile iron) DN500 manufactured in an electric furnace from 100% secondary raw materials (including approximately 40% of recycled scrap and residues from previous casting processes). Combined with a Power Purchasing Agreement (PPA) for electricity and Biogas Purchasing Agreement (BPA) for thermal treatment, total production emissions decrease by approximately 60% compared to conventional blast furnace production (and ~20% versus cupola). For the project, this amounts to avoided emissions of about 140 tons of CO2 in the production phase.

"We are demonstrating here that cast iron and sustainability go together extremely well," says Marloes Meer, Managing Director of Saint-Gobain PAM Netherlands. "Choosing 100 percent secondary material and green energy results in a big CO2 gain, without compromising on quality, service life or the hygienic requirements for drinking water."

Logistics and execution

The pipes were delivered from the Pont-à-Mousson (FR) plant by HVO biofuel truck. This step - part of PAM's Blueway transport concept - reduces logistical CO2 emissions by approximately 83% versus conventional diesel transport. Clear phasing and short closures were chosen on the construction site, coordinated with the surrounding area (including a local sports club), to ensure accessibility and safety.

All pipes delivered are traceable via PAM Track: a QR or data matrix code links physical pipes to digital project data (location, batch, specifications). During transport, storage and installation, pipes are scanned with a smartphone; Dunea gets lifetime access to the project database, including GPS positions.

"For grid operators, this is gold," says Meer. "You already lay the foundation for asset management and faster maintenance at the time of construction. Moreover, it increases installation security: you can see exactly what is where."

CSR: policy embedded in on-site choices
For Saint-Gobain PAM, the pilot is a CSR case in practice. The choices for circular raw materials, renewable energy, low-emission transport and data-driven management align with the broader strategy around Corporate Social Responsibility: reducing environmental impact, working safely and healthily, and fair, transparent chain cooperation.

More: "Our mission of 'Making the world a better home' means we want to reduce impact across the entire life cycle: design for circularity, smarter manufacturing, cleaner transportation and tools that make operations sustainable. This project shows that such an integrated approach works - and is scalable."

Validation: LCA and certification

The environmental benefits have been substantiated with a Life Cycle Assessment (LCA) in accordance with ISO 14040/44 and EN 15804+A2/PCR 2019:14. Bureau Veritas certified litigation, material sourcing and EN 545 compliance; in addition, energy certificates (PPA/BPA) and a Blueway report for transport emissions are available. Transparency and third-party verification are crucial to make claims comparable and testable.

The pilot in Zevenhuizen serves as a proof-of-concept for a broader, modular "low-carbon" offering from PAM in Europe. At the same time, the parent company is working on further electrification of smelting processes, with the aim of structurally reducing direct emissions.

"Our ambition is clear," concludes Meer. "Cast iron drinking water pipes remain the backbone of safe, reliable grids. By linking technology and chain cooperation to our CSR goals, we are making that backbone measurably more sustainable."