As the demand for data storage and compute power surges, so does the environmental impact of the global data center industry. One of the most pressing concerns is water consumption, especially in large-scale cooling systems. In 2025, NTT Global Data Centers has taken a pioneering step by deploying an advanced reverse osmosis (RO) water treatment system at one of its flagship UK data centers—marking a pivotal shift in how operators approach sustainability.
This blog explores how NTT’s reverse osmosis deployment works, why it matters for the industry, and how it positions NTT at the forefront of green innovation in data infrastructure. We’ll examine the technical specifics, the environmental ROI, regulatory context, and broader implications for hyperscale sustainability.
Why Water Efficiency Matters in Data Centers
Data centers are resource-intensive by nature, with water playing a critical role in cooling high-density IT environments. Traditional data center cooling systems often rely on:
- Evaporative cooling towers
- Chilled water loops
- Air-cooled chillers
In many facilities, this can translate to thousands of liters of water per day. According to the Uptime Institute, water usage effectiveness (WUE) can vary widely, with some hyperscale centers consuming over 1.5 million gallons annually. As climate change intensifies and water becomes scarcer, operators are under pressure to mitigate their environmental footprint.
NTT’s reverse osmosis system is a direct response to this challenge.
What Is Reverse Osmosis and How Does It Work?
Reverse osmosis is a water purification process that removes contaminants by using pressure to force water through a semipermeable membrane. In a data center context, this allows for:
- Recycling greywater or captured rainwater for reuse in cooling systems
- Minimizing scale and sediment buildup, increasing equipment longevity
- Reducing reliance on municipal or potable water supplies
NTT’s deployment includes:
- Multi-stage filtration units
- Energy recovery pumps
- IoT-integrated monitoring for flow rate and purity tracking
The system can recover up to 85% of input water, significantly lowering waste.
Inside NTT’s UK Facility: Specs and Goals
The UK facility, located in Dagenham, East London, is part of NTT’s expanding European portfolio. It includes:
- 64MW of IT load capacity
- 100% renewable power sourcing
- Modular design with water-side economizers
- WUE target of under 0.5 L/kWh by Q4 2025
The reverse osmosis system supports:
- Secondary loop recirculation for chilled water
- Automated TDS (total dissolved solids) control
- Integration with AI-based DCIM tools to adjust usage dynamically
This setup not only enhances efficiency—it acts as a blueprint for scalable, sustainable data center design.
Environmental Impact: Measuring the ROI
The environmental returns from NTT’s RO system are significant:
- Water savings of over 20 million liters annually per facility
- Reduction in chemical treatment usage for cooling systems
- Lower carbon emissions from decreased reliance on freshwater transport and treatment
It also supports local water stewardship goals, critical in drought-prone or water-stressed regions. By recycling and treating non-potable water, NTT lessens competition with residential and agricultural water needs.
Additionally, the company plans to publish annual sustainability reports aligned with GRI and CDP frameworks, quantifying:
- Total water withdrawal and discharge
- Percent of recycled water used
- Impact on local watershed health
Regulatory Compliance and Anticipation
NTT’s investment is not just voluntary—it’s proactive. In the UK and EU:
- The EU Taxonomy for Sustainable Activities includes water reuse and efficiency metrics
- UK regulators are considering mandatory WUE disclosures for high-impact facilities
- Water abstraction licenses and discharge permits are tightening
By staying ahead of regulation, NTT reduces compliance risk while gaining reputational and ESG advantages. Investors increasingly favor companies demonstrating climate resilience and transparent reporting.
Technology Integration and Innovation
NTT’s approach integrates reverse osmosis with broader data center automation systems:
- DCIM (Data Center Infrastructure Management) platforms use AI to balance water use with thermal demand
- IoT sensors monitor TDS, flow rates, pressure levels, and membrane health
- Predictive analytics optimize RO maintenance schedules, reducing downtime and chemical use
The facility can dynamically switch between municipal supply, recycled water, or greywater inputs based on demand, weather patterns, and water pricing signals.
NTT is also experimenting with:
- Solar-powered water treatment modules
- Membrane tech co-developed with academic partners to improve rejection rates
- Blockchain-based water sourcing audits for third-party validation
Implications for the Industry
NTT’s move sets a precedent for other operators, especially in Europe where:
- Water-intensive facilities are increasingly scrutinized by governments and NGOs
- Public trust hinges on environmental transparency
- New data center construction permits increasingly require water impact assessments
We expect other major providers like Google, Equinix, and AWS to expand similar efforts. Already:
- Microsoft has pledged water positive operations by 2030
- Google reports site-specific WUE and water sourcing in its ESG filings
- Facebook is piloting closed-loop cooling in desert-based facilities
NTT’s reverse osmosis system shows that green design isn’t only about power—it’s about holistic resource stewardship.
Economic and Competitive Advantages
Beyond compliance and ESG, water efficiency delivers tangible business benefits:
- Lower operating costs: Reduced water purchase and discharge fees
- Extended equipment life: Cleaner cooling water = fewer maintenance issues
- Marketing and sales differentiation: Sustainability can influence colocation buyers and enterprise clients
As green infrastructure becomes a buyer priority, NTT’s approach provides a competitive edge in securing:
- Enterprise workloads with ESG mandates
- Government contracts requiring sustainability benchmarks
- Hyperscaler partnerships looking for environmentally aligned sites
Challenges and Lessons Learned
Implementing reverse osmosis at scale isn’t without hurdles:
- High upfront CapEx: RO systems can be expensive, requiring ROI models over years
- Membrane fouling risks: Without proper pre-treatment, system performance drops
- Skilled labor: RO operation and integration with DCIM requires trained personnel
NTT addressed these via:
- Lifecycle modeling tools during planning
- Vendor partnerships for membrane maintenance and monitoring
- Upskilling local staff through training programs in collaboration with local colleges
Looking Ahead: Scaling Across Regions
NTT has stated that the UK deployment is a pilot for global rollouts, with planned RO deployments in:
- Germany and the Netherlands (where water regulation is strict)
- Singapore and Tokyo (urban areas with limited water availability)
- U.S. West Coast (high demand + water-stressed zones)
In future versions, NTT may explore:
- AI-driven rainwater harvesting systems
- Modular RO containers deployable to colocation sites
- Onsite wastewater treatment for circular reuse
The long-term vision is net-zero water data centers, mirroring net-zero energy efforts already underway.
NTT’s reverse osmosis system in its UK data center isn’t just a technical upgrade—it’s a blueprint for the next generation of sustainable infrastructure. As water scarcity, regulatory oversight, and ESG pressure intensify, operators must innovate beyond traditional cooling.
Reverse osmosis offers a scalable, intelligent, and environmentally responsible solution to one of the data center industry’s most urgent challenges. NTT’s leadership sets a new standard, proving that green infrastructure isn’t just good ethics—it’s good business.
For data center operators, investors, and enterprise clients alike, water management will be as critical as energy in defining digital sustainability in the years to come.
