Five decisions that connect utility planning with commissioning and reliable cooling
Water supply and wastewater acceptance can affect when a data center is built, commissioned, and expanded. Developers and project teams need to understand what the utility can provide, what the cooling system requires, and how temporary construction and commissioning flows will be managed. When those answers come late, they become schedule risk: capacity that was never reserved, a utility condition that must be met before construction, or a cooling loop that cannot be flushed because no discharge route is approved.
These questions are easier to resolve while site, equipment, and schedule decisions can still change.
Industry resource
AWWA’s Cooling the Cloud report
The American Water Works Association (AWWA) has released its October 2026 report, Cooling the Cloud: Considerations for Water Utilities Evaluating Data Center Development, developed in collaboration with Carollo Engineers.
Apex’s perspective
For Apex Water + Process, the practical implication is to connect utility planning with cooling-system requirements early. Cooling designs that minimize routine water consumption still need a plan for fluid quality, system preparation, waste handling, and ongoing operation.
The five decisions below reflect Apex’s independent perspective on turning early planning into commissioning readiness and reliable operation.
Confirm Utility Service Conditions and Infrastructure Dependencies
Engage both the water provider and wastewater utility during site due diligence. Confirm available service, the assumptions behind capacity estimates, and what must happen before a commitment becomes effective. Do not assume a will-serve letter guarantees capacity; clarify its conditions, duration, and reservation terms.
Discuss each campus phase, potential off-site improvements, cost responsibility, and the timing of approvals and construction. Where backup supply or curtailment could affect operation, define the required arrangements. Include these dependencies in the project schedule and budget.
Check local cooling restrictions before equipment selection. For example, since August 31, 2023, the Las Vegas Valley Water District has prohibited approval of new permits for commercial and industrial buildings in its service area that plan to use evaporative cooling. That is a specific local requirement, not a nationwide rule; where similar rules apply, confirm whether adiabatic or hybrid assist is treated the same way.
The useful outcome is a documented set of service assumptions and outstanding decisions that the owner, design team, and utility can review as the project develops.
Build Demand Estimates Around the Actual Cooling Design
Prepare a project-specific water balance for each development phase. Account for expected IT load, cooling mode, local weather, treatment recovery, and operating sequence. Show average and peak demand, seasonal variation, temporary commissioning needs, and expected wastewater flows. Distinguish water withdrawn from water consumed, and identify each source. A generic water-use benchmark cannot describe all of these project conditions.
Confirm the utility’s submission requirements and applicable professional licensure or certification requirements.
Keep heat rejection separate from how heat is collected at the IT equipment. The following comparison addresses the final heat-rejection arrangement.
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| Heat rejection | Routine on-site water use | What to confirm |
|---|---|---|
| Evaporative towers | Makeup replaces evaporation, blowdown, and drift losses. | Peak supply, source quality, treatment and microbial control, concentration limits, and blowdown management. |
| Dry coolers | No evaporative water use in purely dry operation. | Design-day capacity, required fluid temperatures, equipment footprint, and any supplemental cooling. |
| Adiabatic-assisted equipment | Water use depends on weather and when assist operates. | Peak assist flow, manufacturer-specific water quality, controls, and drain or waste streams. |
| Air-cooled chillers | No evaporative water use at a dry condenser. | Electrical demand, performance at high ambient temperatures, and circulating-fluid requirements. |
Direct-to-chip and immersion cooling collect heat at the IT equipment and connect to a facility cooling arrangement. They do not, by themselves, determine campus water demand. Map the technology and facility loops separately, with the appropriate fluid, material-compatibility, and equipment requirements for each.
Match Source Quality and Treatment to the Application
Available water must also be suitable for its intended use. Characterize the proposed source and its expected variability, then compare the results with the requirements of the cooling equipment, fluid supplier, and treatment program. Relevant parameters may include hardness, silica, chlorides, suspended solids, and microbial conditions.
For evaporative systems, achievable cycles of concentration depend on makeup-water quality and treatment. Increasing concentration can reduce makeup and blowdown volumes while increasing dissolved-solids concentrations. Evaluate the cooling and wastewater implications together.
Evaluate reclaimed water using its actual quality, availability, and treatment needs. Confirm seasonal limitations, backup arrangements, and what happens during a supply interruption. Select treatment for the constituents that limit the intended use; ordinary particle filtration does not address dissolved salts.
Before a source change or future reuse conversion, review material compatibility, treatment settings, monitoring, and startup procedures. That review helps the project team understand what must change before the new source is introduced.
Plan Commissioning Water and Wastewater Together
Filling, hydrostatic testing, flushing, cleaning, and disinfection can create temporary demands and waste streams that differ from routine operation. Plan those activities while the mechanical sequence and contractor scopes are being developed. Public Open Compute Project guidance for preparing technology cooling system row manifolds also addresses water supply, wastewater capture, and disposal planning.
Before mobilization, align the design, mechanical, commissioning, and water-treatment teams on four practical items:
- Water supply and quality, including expected volumes, peak flow, delivery method, and storage.
- Preparation chemistry and safety data sheets, with expected waste characteristics and sampling needs.
- An authorized disposal route, including any required treatment, controlled release, temporary containment, or off-site hauling.
- Responsibility for temporary equipment, testing, release decisions, and changes to the sequence.
Do not assume that flushing water or spent cooling fluid can enter the sewer. Confirm the receiving utility’s acceptance conditions and applicable limits. Startup sampling can help verify predicted wastewater characteristics; subsequent routine discharge remains subject to those conditions.
The same planning applies when zero liquid discharge is intended during normal operation. Establish an approved route for commissioning, maintenance, and upset-condition wastes. Depending on the project, this may involve authorized sewer discharge, containment and treatment, or off-site hauling.
Put these arrangements on the commissioning schedule. A mechanically complete loop can still face commissioning delays if filling, flushing, or waste-handling arrangements are unresolved. The team needs a workable method to prepare and verify the system, together with the temporary services and waste-handling arrangements needed to carry it out.
Assign Responsibilities and Keep Requirements Current
Use the following as a starting point for coordination. Final responsibilities should follow contract scopes, permit conditions, the delivery model, and owner requirements.
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| Project role | Responsibilities to assign and confirm | Delivery risk to address |
|---|---|---|
| Owner and developer | Utility relationships, capacity conditions, phased demand, infrastructure costs, and service agreements. | Unresolved service or funding conditions. |
| EPC and design lead | Water balance, cooling basis of design, fluid and treatment requirements, and infrastructure interfaces. | Incompatible assumptions or late redesign. |
| General contractor | Temporary water service, construction water and dewatering, site discharge authorizations, and coordination with off-site utility work. | Temporary services not in place when needed. |
| Mechanical contractor | Approved filling, flushing, and cleaning sequence, including passivation or disinfection where specified; chemical submittals and safety data sheets; temporary containment; and use of the approved disposal route. | Loop cannot be flushed or drained; commissioning slips. |
| Commissioning team | Test methods, sampling, acceptance evidence, corrective actions, and turnover coordination. | Incomplete verification or delayed acceptance. |
| Owner’s operations team | Operating baseline, monitoring, ongoing water management, and response to changing conditions. | Unclear ownership after turnover. |
Define a review path for changes that materially affect demand, fluid requirements, discharge characteristics, or approved service assumptions. A change in cooling equipment, source water, or treatment chemistry may need input from the owner, engineer, equipment supplier, and utility before implementation.
At turnover, provide approved fluid information, baseline test results, sampling locations, operating settings, corrective-action records, and ongoing service responsibilities. The operating team should be able to use these records to evaluate later changes.
Summary
Before Major Design and Schedule Commitments
- Confirm utility capacity assumptions, service conditions, infrastructure dependencies, and cost responsibility.
- Align the phased water balance with the proposed cooling design and operating conditions.
- Define source-water, treatment, and cooling-fluid requirements.
- Plan temporary commissioning water, preparation chemistry, and authorized waste handling.
- Assign testing, acceptance, and turnover responsibilities; establish change review and ongoing monitoring requirements.
Frequently Asked Questions About Data Center Water Readiness
What is data center water readiness?
Data center water readiness means confirming that water supply, water quality, cooling-fluid requirements, and waste-handling arrangements support the proposed project. Before finalizing design, define utility service conditions, phased demand, treatment needs, temporary commissioning flows, disposal routes, acceptance responsibilities, and ongoing monitoring. These decisions should inform the project schedule and budget.
Does a utility will-serve letter guarantee water capacity?
A will-serve letter should not be treated as an unconditional capacity guarantee. Project teams should confirm the utility’s conditions, reservation terms, duration, infrastructure dependencies, and requirements before service becomes effective. Review water supply and wastewater acceptance with the respective utilities for each planned development phase.
Does liquid cooling mean a data center will use more water?
Liquid cooling at the IT equipment does not, by itself, determine a data center’s water consumption. Direct-to-chip and immersion systems collect heat, while the facility’s heat-rejection arrangement influences routine water use. Evaporative towers, dry coolers, adiabatic-assisted equipment, and air-cooled chillers have different requirements. Fluid preparation and commissioning waste still need planning.
What should a data center water balance include?
A data center water balance should identify each water source and distinguish water withdrawn from water consumed. It should account for development phases, expected IT load, cooling mode, weather, treatment recovery, operating sequence, average and peak demand, seasonal variation, temporary commissioning needs, and expected wastewater flows. Confirm the utility’s submission requirements.
Can data center flushing water or spent coolant go to the sewer?
Do not assume sewer discharge is allowed. Confirm the receiving utility’s acceptance conditions, applicable limits, expected waste characteristics, and sampling needs before work begins. Establish an approved route, which may include authorized sewer discharge, treatment and containment, or off-site hauling. Projects targeting zero liquid discharge during normal operation still need a plan for commissioning and maintenance wastes.
Can data centers use reclaimed water for cooling?
Reclaimed water may be suitable when its quality, availability, and treatment requirements match the intended application. Evaluate seasonal limits, supply interruptions, backup arrangements, equipment and material compatibility, and monitoring needs. Treatment should address the constituents that limit use; ordinary particle filtration does not remove dissolved salts. Reassess requirements before a source change or reuse conversion.
Who is responsible for data center water and cooling-fluid readiness?
Water and cooling-fluid readiness requires coordination among the owner, design/EPC team, general contractor, mechanical contractor, commissioning team, and operations team. Assign responsibilities according to contract scopes, permit conditions, the delivery model, and owner requirements. Document who manages temporary services, preparation, disposal, testing, acceptance, corrective actions, and turnover so responsibilities remain clear as the project develops.
How does Apex support data center water readiness?
Through Fluid-to-Facilityâ„¢, Apex Water + Process supports source-water evaluation, treatment and cooling-fluid requirements, laboratory testing, commissioning technical support, and ongoing monitoring. Apex helps project teams define and verify the water and fluid conditions needed for reliable cooling and connect early planning decisions with startup, turnover, and long-term operation.
Connect Utility Planning With Cooling Reliability
These decisions influence one another. Cooling architecture affects demand. Source quality affects treatment and fluid preparation. Commissioning establishes the starting conditions and records that operations will rely on.
Through Fluid-to-Facilityâ„¢, Apex Water + Process helps project teams connect source-water evaluation, treatment and cooling-fluid requirements, laboratory testing, commissioning technical support, and ongoing monitoring. Our role is to help teams define and verify the water and fluid conditions needed for reliable cooling throughout the facility lifecycle.
Planning a new data center or campus expansion? Use Apex’s Data Center Water & Cooling Fluid Risk and Readiness Checklist to identify decisions that need attention before design is finalized.
This article presents Apex’s independent perspective and has not been reviewed or endorsed by AWWA or any utility referenced.
Brett Robison
Director of Corporate Accounts
Brett works with data center operators, project delivery teams, cooling manufacturers, and technology partners on liquid cooling and thermal management. His business development work connects cooling infrastructure decisions with reliable operation and future growth.