Water & Chemical FAQ: Hildebran Data Center
Digi Power X filings describe 200 MW of North Carolina power as anticipated for future development by 2028, subject to approvals, infrastructure development, and other conditions.
No project-specific cooling design, chemical inventory, water-demand plan, or wastewater plan has yet been publicly documented.
The public should not have to rely on general descriptions such as “closed-loop” or “standard industry practice.” The specific cooling design, heat-rejection method, chemical inventory, discharge plan, and emergency procedures determine the actual risks.
What type of cooling system will this facility use?
The developer should publicly identify the exact cooling technology planned for the site.
“Closed-loop” can describe several different systems, including:
- Chilled-water loops with dry coolers
- Hybrid systems with adiabatic assist
- Direct-to-chip liquid cooling
- Immersion cooling
- Systems using water-glycol mixtures or dielectric fluids
Different technologies create different water, chemical, spill, and maintenance risks.
How much water will it use?
The phrase “closed-loop” does not by itself establish how much water a facility will consume.
A sealed cooling loop connected to dry coolers may require relatively little process water during normal operation. A closed building loop that transfers heat to cooling towers, adiabatic equipment, or other evaporative systems may still require substantial makeup water.
Water may also be needed for:
- Evaporative or adiabatic heat rejection
- Humidity control
- Equipment cleaning
- Initial filling and commissioning
- Periodic draining, flushing, and refilling
- Water-treatment processes
- Maintenance and leak replacement
The developer should disclose:
- Average daily water demand
- Maximum daily water demand
- Estimated annual consumption
- Water use during extreme heat
- Water use during drought restrictions
- Full-buildout assumptions for every proposed phase
- Amount of water discharged as blowdown or maintenance waste
What chemicals will be in the closed loop?
Closed-loop cooling systems may require chemical treatment to prevent corrosion, scaling, and biological growth.
The developer should disclose the full chemical inventory, including:
- Product names
- CAS numbers
- Safety Data Sheets
- Expected annual usage volumes
- Storage locations
- Disposal procedures
- Spill response plans
Possible treatment categories may include:
- Corrosion inhibitors
- Biocides
- Oxygen scavengers
- pH buffers
- Glycol, if freeze protection is used
The community should not accept vague language such as “standard industry treatment” in place of a full chemical disclosure.
Will fluorinated coolants or PFAS-containing fluids be used?
Liquid cooling or immersion cooling does not automatically mean that PFAS-containing fluids will be used.
However, fluorinated dielectric heat-transfer fluids have been used in some electronics and specialized cooling applications. The only reliable way to determine the risk is to identify the exact products proposed for this facility.
The developer should disclose:
- Product and manufacturer names
- Chemical names and CAS numbers
- Safety Data Sheets
- Whether the manufacturer identifies the product as containing PFAS
- Total volume stored or circulated on site
- Expected replacement and disposal schedule
- Secondary containment design
- Leak-detection systems
- Spill response and notification procedures
- Approved disposal or recycling method
The community should not assume that fluorinated fluids will be used, but it should require a clear written statement confirming whether they are or are not part of the proposed design.
Where does wastewater go?
Closed-loop does not automatically mean zero discharge.
The system may produce wastewater from:
- Periodic flushing and draining
- Loop maintenance
- Water-treatment reject streams
- Leaks and blow-off
- Cleaning and equipment maintenance
The developer should identify the receiving entity and disposal pathway:
- Municipal wastewater system
- Industrial pretreatment program
- NPDES discharge
- Trucked off-site disposal
- Dedicated containment and treatment
The receiving treatment system must be able to handle the chemical profile and peak discharge volume, including a possible loop drain-down event.
What about Legionella and other pathogens?
Legionella risk depends on the actual equipment used.
Cooling towers and other systems that store warm water and generate aerosols can allow Legionella to grow and spread. This includes the open evaporative portion of some closed-circuit cooling-tower systems.
A sealed hydronic loop connected only to dry coolers presents a different exposure pathway and should not be treated as equivalent to an evaporative cooling tower.
The developer should disclose whether the facility will use:
- Open or closed-circuit cooling towers
- Adiabatic spray or mist systems
- Evaporative condensers
- Humidification equipment
- Water storage or recirculation basins
- Any equipment capable of producing water aerosols
Where applicable, the developer should provide a water-management program addressing:
- Biofilm and microbial-growth control
- Water-treatment procedures
- Routine inspection and testing
- Shutdown and restart procedures
- Maintenance activities that may create aerosols
- Corrective actions when control limits are exceeded
How will heat be rejected?
Every cooling system must ultimately release heat, but that does not necessarily mean heated water will be discharged.
The developer should disclose whether heat will be rejected through:
- Dry coolers
- Cooling towers
- Adiabatic or evaporative equipment
- Chillers
- Wastewater discharge
- Surface-water discharge
- Another heat-recovery or heat-rejection system
If heated water will be discharged, the developer should disclose:
- Receiving water or wastewater system
- Maximum discharge temperature
- Maximum discharge volume
- Applicable permit limits
- Effects during maximum facility load
- Effects during hot and low-flow conditions
- Required temperature and water-quality monitoring
What monitoring and reporting should be public?
Monitoring requirements should be based on the actual cooling design, chemicals, discharge pathway, and applicable permits.
Public reporting should include, where relevant:
- Metered monthly and annual water consumption
- Maximum daily water demand
- Wastewater and blowdown volumes
- Current chemical inventory and Safety Data Sheets
- Permit-required sampling results
- Spill, leak, and reportable-incident notices
- PFAS testing when fluorinated fluids or another credible PFAS source is identified
- Baseline and follow-up groundwater testing when a plausible groundwater pathway exists
- Independent compliance or chemical-management audits
What happens if there is a catastrophic leak?
A major cooling-system failure could release chemically treated water or cooling fluid quickly.
The developer should disclose:
- Secondary containment capacity
- Floor drain destinations
- Whether drains lead to sanitary sewer, stormwater, or containment sumps
- Spill shutoff procedures
- Town, county, and state notification protocol
- Emergency response responsibilities
- Environmental remediation funding
Who pays if something goes wrong?
The community should require financial guarantees before approval.
Minimum protections should include:
- Parent-company guarantee for environmental liabilities
- Environmental remediation bond
- Developer-funded well testing within a defined radius
- Pre-construction baseline testing
- During-construction monitoring
- Post-construction testing
- Clear responsibility for cleanup costs
The Core Question
Before any approval, Hildebran should require a complete, independent accounting of:
- What cooling system will be used
- What chemicals will be stored and circulated
- How wastewater will be handled
- What happens during leaks or drain-down events
- Who pays for cleanup if something goes wrong