Understanding Wastewater Source Options for Data Centers

Not all wastewater is equal for cooling applications. Three primary source categories offer distinct advantages and implementation considerations for water reuse data centers:

Municipal wastewater: Treated effluent from municipal wastewater treatment plants represents the most scalable option. These facilities produce consistent volumes with relatively predictable quality characteristics. Municipal sources work best for data centers located within 5-10 miles of treatment plants, minimizing conveyance infrastructure costs.

The City of Phoenix operates a dedicated recycled water distribution system serving multiple data centers. Facilities receive tertiary-treated municipal wastewater that meets stringent quality standards for cooling applications. This infrastructure model is expanding to other water-stressed markets.

Industrial wastewater: Manufacturing facilities, refineries, and power plants generate significant wastewater volumes. On-site treatment or collaborative treatment arrangements can convert these streams into cooling water supplies. Industrial wastewater partnerships work particularly well for data centers co-located near industrial parks or manufacturing zones.

Quality varies significantly based on source operations. Food and beverage industry wastewater contains high organic loads requiring biological treatment. Semiconductor manufacturing wastewater may contain specific contaminants but typically features lower total dissolved solids than municipal sources.

On-site wastewater: Data centers generate wastewater from cooling tower blowdown, reverse osmosis reject streams, and facility processes. Advanced data center water treatment systems can recover 70-90% of this water for reuse in cooling systems. Cooling tower water reuse eliminates supply chain dependencies and reduces discharge volumes.

One hyperscale facility in Texas implemented on-site treatment to recover cooling tower blowdown. The system processes 2.5 million gallons monthly, reducing municipal water consumption by 35% while eliminating blowdown discharge fees.

Data Center Water Treatment Requirements for Cooling Applications

Cooling systems impose specific water quality requirements to prevent scaling, corrosion, biological growth, and fouling. Data center water treatment design must address both source water characteristics and end-use specifications.

Key water quality parameters for cooling applications include:

Total dissolved solids (TDS): Target range of 500-1,500 mg/L for most cooling tower systems. Higher TDS concentrations increase scaling potential and corrosion rates. Municipal wastewater typically ranges from 600-1,200 mg/L TDS after secondary treatment.

Hardness: Calcium and magnesium concentrations should remain below 200-400 mg/L as CaCO₃ to minimize scale formation. Softening or scale inhibitor programs manage hardness in source water exceeding these levels.

Suspended solids: Cooling water specifications typically limit suspended solids to 10-25 mg/L. Particulates cause fouling in heat exchangers and promote microbial growth in cooling towers.

Biological content: Total coliform and heterotrophic bacteria counts must be controlled to prevent biofilm formation. While absolute sterility isn’t required, bacterial counts should remain below 10,000 CFU/mL through continuous disinfection.

pH and alkalinity: Optimal pH ranges from 6.5-8.5 for most cooling systems. Alkalinity between 50-200 mg/L as CaCO₃ provides buffering capacity while limiting scale potential.

Genesis Water Technologies Treatment Solutions

Genesis Water Technologies has developed specialized data center water treatment solutions addressing the unique requirements of wastewater reuse for data center cooling applications. These systems integrate proven GWT technologies with advanced monitoring and control to deliver reliable, cost-effective water quality.

GWT Self-Cleaning Spiral Filtration Systems

Genesis self-cleaning spiral filtration technology provides continuous solids removal without backwash interruptions or chemical cleaning requirements. The system employs a unique spiral design that creates centrifugal forces, continuously moving captured solids to a central collection point for automated purging.

Key advantages for wastewater pretreatment:

• Continuous operation without backwash cycles maximizes system availability
• No backwash water generation reduces waste stream volumes by 95% compared to conventional media filters
• Effective removal of suspended solids down to 10 microns
• Minimal maintenance requirements with self-cleaning mechanism
• Compact vertical design minimizes floor space requirements
• Suitable for variable source water quality applications

Self-cleaning spiral filtration proves particularly valuable for pretreating municipal or industrial wastewater ahead of membrane systems. The technology removes particulates that would otherwise foul ultrafiltration or reverse osmosis membranes, extending membrane life and reducing cleaning frequency.

One 7-MW facility treating variable-quality industrial wastewater deployed Genesis spiral filtration as primary pretreatment. The system handles suspended solids spikes from upstream manufacturing operations without performance degradation, protecting downstream UF membranes and maintaining consistent cooling water quality.

GWT Ultrafiltration and Nanofiltration Systems

Genesis Water Technologies offers customized membrane filtration systems specifically configured for wastewater reuse applications. These systems employ hollow fiber ultrafiltration (UF) membranes that provide absolute barriers against bacteria, viruses, and particulates while maintaining high flux rates and chemical cleaning tolerance necessary for wastewater applications.

The UF systems feature:

• High-efficiency membranes achieving 99.99% pathogen removal without chemical disinfection
• Advanced backwash sequences optimized for wastewater feed streams
• Integrated cleaning-in-place (CIP) systems with automated chemical dosing
• Real-time membrane integrity monitoring ensuring consistent barrier performance

For applications requiring additional dissolved solids reduction, Genesis nanofiltration (NF) systems provide selective hardness removal and partial TDS reduction. NF technology operates at lower pressure than reverse osmosis, reducing energy consumption by 30-40% while achieving targeted removal of calcium, magnesium, and multivalent ions that cause scaling.

A 10-MW facility treating industrial wastewater from an adjacent manufacturing complex deployed Genesis UF/NF treatment. The system processes 150 GPM of source water containing variable suspended solids and hardness levels. UF membranes eliminate particulates and microorganisms, while NF reduces hardness from 350 mg/L to 120 mg/L, meeting cooling tower specifications without conventional softening equipment.

GWT GCAT Catalytic Activation Treatment

Genesis GCAT (Catalytic Activation Treatment) technology represents an innovative approach to organic contaminant removal and water quality enhancement. This catalytic activation system employs proprietary catalyst bead media that accelerate oxidation reactions, neutralize charged contaminants and improve overall water quality.

GCAT technology advantages for data center wastewater applications:

• Effective remediation of complex organic compounds resistant to conventional biological treatment
• Compact footprint suitable for space-constrained data center sites
• Minimizes chemical consumption reducing operational complexity
• Effective pretreatment ahead of membrane systems

For on-site wastewater treatment applications, GCAT technology integrates effectively with Zeoturb liquid bio-organic flocculant clarification. This flexibility allows a tailored treatment approach matching specific source water characteristics.

GWT Reverse Osmosis Systems

When source water TDS exceeds cooling system tolerances or facilities require high-purity makeup water, Genesis reverse osmosis (RO) systems deliver comprehensive dissolved solids removal. These systems incorporate advanced membrane elements and intelligent controls optimized for wastewater treatment applications.

Genesis RO systems feature:

• Multi-stage design maximizing water recovery while minimizing concentrate volume
• Antiscalant dosing and pretreatment integration preventing membrane fouling
• Variable frequency drives optimizing energy consumption across flow ranges
• Concentrate management options including further treatment or discharge conditioning

Critical for data centers in water-stressed regions, Genesis Water Tech RO systems can be used for tertiary concentrate recovery. This approach reduces concentrate wastewater discharge, enabling facilities to secure permits in watersheds with stringent discharge limitations.

A hyperscale operator requested Genesis RO technology for treating municipal wastewater for cooling makeup across multiple facilities. The primary/secondary RO system configuration achieves 88% overall water recovery, producing 98% TDS reduction while concentrating reject streams to reduce discharge requirements.

GWT Specialized Electrocoagulation Technology

This specialized electrocoagulation technique is designed to remove suspended solids, colloids, oils, and heavy metals from municipal and industrial wastewater sources with elevated conductivity for data center cooling water usage.

This technology operates with minimal chemical usage in post clarification, reducing operating costs and eliminating sludge handling associated with conventional clarification.

Important application requirement: Genesis EC technology requires source water conductivity or TDS levels exceeding 1,000 ppm to function effectively. This makes this technology particularly well-suited for high-TDS industrial wastewater, concentrated cooling tower blowdown, or municipal wastewater in regions with naturally elevated dissolved solids. For lower-TDS source waters, alternative GWT pretreatment technologies such as self-cleaning spiral filtration along with Zeoturb and GCAT catalytic activation treatment are recommended.

GWT Genclean-S Tablet Technology

Genclean-S tablet technology represents an innovative solid-phase water treatment solution utilizing a proprietary zinc-silver ionic combination that addresses multiple cooling water challenges simultaneously.

Unlike conventional chemical biocides, Genclean-S tablets provide comprehensive water conditioning through controlled release of zinc and silver ions in compliance with NSF and EPA regulations.

Multi-functional water treatment benefits:

Microbiological control: The zinc-silver ionic combination delivers broad-spectrum antimicrobial activity controlling bacteria, algae, and fungi without harsh oxidizing chemicals. Silver ions disrupt cellular respiration and DNA replication, preventing microbial reproduction. This mechanism provides effective Legionella control and biofilm prevention in cooling tower systems utilizing treated wastewater.

Scale inhibition: Zinc ions interfere with crystal formation and growth, preventing calcium carbonate, calcium sulfate, and silica scale deposition on heat transfer surfaces. This capability proves particularly valuable when treating wastewater sources with elevated hardness or alkalinity that would typically require aggressive chemical scale inhibitor programs.

Corrosion mitigation: The zinc component provides cathodic protection to metal surfaces, forming protective zinc oxide films that resist corrosion from chlorides, sulfates, and other aggressive ions commonly present in treated wastewater. This reduces metal release into cooling water and extends equipment service life.

Key advantages for cooling tower water reuse:

• Simplified treatment program addressing biological control, scaling, and corrosion with single product
• No hazardous chemical storage or handling requirements compared to liquid biocides or inhibitors
• Consistent, controlled ion release over extended periods (typically 30-90 days per tablet)
• Reduced operator intervention and chemical feed complexity
• Compatibility with treated wastewater sources including variable-quality municipal and industrial streams
• Enhanced safety profile eliminating liquid chlorine, hypochlorite, or aggressive acid handling
• Lower total cost of ownership for small to mid-sized facilities
• Regulatory compliance support for Legionella management programs per ASHRAE Standard 188

Application considerations:

Genclean-S tablets install directly in cooling tower sumps, recirculation piping, or dedicated dosing chambers. Tablet quantity and replacement frequency depend on system volume, water quality, and cycles of concentration. The technology proves particularly effective for facilities operating at higher cycles of concentration enabled by treated wastewater, where conventional chemical programs become increasingly complex and costly.

The absence of oxidizing biocides eliminates concerns about disinfection byproduct formation or accelerated corrosion from chlorine or bromine compounds.

This characteristic makes Genclean-S particularly suitable for systems utilizing alternative water sources where source water variability might interact unpredictably with conventional chemical treatments.

A 2-MW edge data center utilized Genclean-S tablets as the primary water treatment program in a cooling tower system utilizing treated municipal wastewater. The installation eliminated chemical feed pumps, storage tanks, and complex inhibitor programs while maintaining heterotrophic plate counts below 1,000 CFU/mL, preventing scale formation, and achieving corrosion rates below 2 mils per year.

The facility achieved full Legionella risk management compliance with quarterly testing demonstrating non-detectable Legionella levels.

Integrated GWT Treatment Solutions

Most data center applications require integrated treatment trains combining multiple Genesis Water Technologies solutions. GWT engineers design customized systems prioritizing the most effective technology combinations for specific source water characteristics, cooling system requirements, site constraints, and operational preferences.

For municipal wastewater with TDS exceeding 1,000 ppm:

1. GWT self-cleaning spiral filtration for continuous solids removal without backwash
2. GWT EWS electrocoagulation removing fine suspended solids and reducing membrane fouling potential (when conductivity requirements are met)
3. GWT ultrafiltration membranes providing absolute barrier against pathogens and particulates
4. Partial GWT RO treatment for hardness control (treating 30-50% of flow)
5. GWT Genclean-AOP for final disinfection and organic removal
6. GWT Genclean-S tablets for comprehensive cooling tower water conditioning

For lower-TDS municipal wastewater below 1,000 ppm:

1. GWT self-cleaning spiral filtration for primary solids removal
2. GWT GCAT catalytic activation treatment for organic contaminant destruction and water quality enhancement
3. GWT ultrafiltration membranes for pathogen and particulate removal
4. Selective GWT nanofiltration or RO as needed for dissolved solids control
5. GWT Genclean-AOP for final disinfection
6. GWT Genclean-S tablets for cooling tower biological control and water conditioning

For industrial wastewater with complex organic content:

1. GWT self-cleaning spiral filtration for suspended solids removal
2. GWT GCAT catalytic activation treatment breaking down recalcitrant organics
3. GWT Zeoturb biological treatment for biodegradable organic and nutrient removal
4. GWT ultrafiltration for membrane bioreactor (MBR) configuration or standalone pathogen barrier
5. GWT RO for dissolved solids control as needed
6. GWT Genclean-AOP for final polishing
7. GWT Genclean-S tablets for cooling tower water management

For on-site cooling tower water reuse:

1. GWT GCAT catalytic activation treatment for organic breakdown in high-TDS blowdown
2. GWT Zeoturb for biological treatment of organics and nutrients
3. GWT ultrafiltration for particulate and pathogen removal
4. GWT RO for dissolved solids control enabling high recovery rates
5. Concentrate management through evaporation or crystallization
6. GWT Genclean-S tablets for simplified water conditioning in recirculating system

These integrated GWT treatment trains achieve comprehensive treatment while optimizing capital costs and operating expenses. The modular design allows scaling from small edge facilities to hyperscale campuses, with each technology component selected for optimal performance matching source water characteristics and treatment objectives.

Regulatory Framework and Permitting

Alternative water source implementation requires navigation of federal, state, and local regulations governing water reuse, discharge, and cooling system operation.

Key regulatory considerations:

Water reuse permits: Most states require permits for non-potable water reuse applications. California’s Title 22 regulations establish treatment and quality standards for recycled water used in cooling towers. Other states reference EPA guidelines or maintain state-specific programs.

Permit applications typically require demonstration of adequate treatment, monitoring protocols, cross-connection prevention, and operational safeguards. Genesis Water Technologies assists clients with regulatory compliance documentation, pilot testing data, and treatment validation studies supporting permit applications. Approval timelines range from 6-18 months depending on jurisdiction and project complexity.

Discharge permits: On-site treatment systems generating concentrate or blowdown require National Pollutant Discharge Elimination System (NPDES) permits for surface water discharge or pretreatment permits for sanitary sewer discharge. Permit limits address conventional parameters (BOD, TSS, pH) and may include specific limitations for metals, nutrients, or other constituents.

Zero liquid discharge (ZLD) systems eliminate wastewater discharge, avoiding permit requirements but increasing capital and operating costs. Genesis ZLD solutions integrate membrane concentration with thermal treatment, producing solid residuals for disposal while recovering maximum water for reuse. Some facilities pursue ZLD to secure permits in water bodies with limited assimilative capacity or stringent water quality standards.

Cross-connection control: Regulations strictly prohibit physical connections between potable and non-potable water systems. Implementation requires separate piping (typically color-coded purple), backflow prevention, and signage identifying non-potable water. Many jurisdictions mandate reduced-pressure backflow preventers at all potable water connections.

Working with Genesis Water Technologies’ technical team and early engagement with regulatory agencies streamlines permitting and ensures compliance with applicable requirements.

Risk Management and Operational Considerations

Transitioning to treated wastewater requires robust operational protocols addressing supply reliability, water quality variability, and system integration. Genesis Water Technologies designs data center water treatment systems with monitoring and control capabilities that mitigate operational risks.

Supply security: Unlike potable water backed by redundant sources and storage, alternative water sources data centers may face availability constraints during source maintenance, treatment system outages, or source water quality upsets.

These treatment systems can be designed to incorporate risk mitigation features:

• Dual-source capability maintaining potable water as a backup supply with switching capabilities
• On-site storage integrated with treatment systems providing 2-7 days cooling water inventory
• Water quality monitoring with automated shutdown when parameters exceed specifications
• Remote monitoring and diagnostics enabling rapid troubleshooting and support

Water quality monitoring: Genesis Water Tech treatment systems can include continuous monitoring instrumentation to ensure cooling water meets specifications and enables rapid response to quality excursions.

Data center cooling water quality monitoring configurations include:

• Source water monitoring for TDS, conductivity, turbidity, pH, temperature, and flow
• Intermediate monitoring verifying individual treatment process performance
• Final water quality monitoring confirming specifications compliance
• Cooling system monitoring tracking cycles of concentration, zinc and silver ion levels (for Genclean-S systems), and biological activity

This visibility enables proactive maintenance and optimization without constant on-site presence.

Legionella management: Cooling towers provide favorable conditions for Legionella growth regardless of water source. ASHRAE Standard 188 requires water management programs addressing Legionella risk through temperature control, biocide application, and routine monitoring.

Genesis treatment systems incorporating Genclean-S tablets provide multi-barrier approaches that significantly reduce Legionella risk.

Genclean-S zinc-silver ionic control provides continuous antimicrobial activity in the cooling system, preventing biofilm formation and Legionella colonization without creating disinfection byproducts or chemical residuals requiring removal.

Corrosion and scaling control: Alternative water sources may require adjusted chemical treatment programs compared to potable water.

Elevated chlorides or sulfates in some wastewater sources increase corrosion potential. Higher hardness or alkalinity increases scaling tendency.

Genesis Water Technologies conducts water quality assessments and pilot testing using actual source water to develop optimized process treatment programs.

Genclean-S tablets provide integrated scale and corrosion control, simplifying water management for facilities utilizing treated wastewater with challenging chemistry.

This approach validates treatment effectiveness and cooling system compatibility before full-scale implementation. Corrosion coupon monitoring and scale tendency calculations validate program effectiveness during operations.