Reclaimed Water Tank For Data Center: Municipal Supply And Recycle Integration
Created on Today
Reclaimed Water Tank For Data Center: Municipal Supply And Recycle Integration
A reclaimed water tank for a data center receives treated municipal effluent through a dedicated non-potable mains, stores it as a separate reserve, and blends it with on-site recycled streams for cooling-tower makeup and other non-potable uses. The defining feature is the dual-pipe intake: reclaimed water never shares a main with potable supply, and continuous quality monitoring protects the cooling system from conductivity, nutrient or microbial excursions. Sizing follows the reclaimed supply contract and the site's non-potable demand, not the chilled-water loop, and the internal finish must tolerate a variable, often higher-conductivity influent.
Many water-stressed jurisdictions now deliver reclaimed (tertiary-treated municipal) water as a utility service, and data centers are among the largest eligible off-takers because most of their demand is cooling, not human consumption. A reclaimed supply can cut a campus's potable draw sharply, but only if the intake, storage and blending are engineered so a variable municipal effluent never harms the cooling towers or cross-contaminates potable infrastructure. The failures are predictable: a single blended main, a tank sized to the wrong demand, or no monitoring at the inlet to catch a quality excursion.
This guide works the reclaimed water tank for a data center from municipal intake through monitoring to blend, and sets out the material and sizing choices that keep the reserve safe, separated and dependable.
Dual-Pipe Intake: Keeping Reclaimed Separate From Potable
Reclaimed water arrives through its own dedicated non-potable main, and that separation is the single non-negotiable rule of the system. A dual-pipe arrangement is what lets a campus buy reclaimed water at scale without creating a cross-connection hazard.
1. Dedicated reclaimed service. A separate metered mains from the utility, colour-coded purple by convention, delivering tertiary-treated effluent to the site boundary.
2. Physically isolated on-site ring. The reclaimed distribution shares no tee, valve or fitting with the potable ring; air-gap or backflow-protected break-tank separation is used wherever the two systems come near each other.
3. No direct potable interface. Any potable top-up enters through an air gap, never by a hard pipe, so a pressure reversal cannot drive reclaimed water into the drinking supply.
The tank is the first on-site asset the reclaimed main fills, so its specification and labelling set the tone for the whole non-potable system.
Quality Monitoring: Protecting The Cooling System
Reclaimed municipal effluent varies by utility and season, so inlet monitoring is what lets you use it safely in cooling towers. Cooling towers concentrate dissolved solids; a high-conductivity reclaimed feed accelerates scaling and corrosion unless blowdown and dosing are tuned to it.
· Conductivity and TDS. Continuous measurement gates the feed and triggers blending or blowdown adjustment when the reclaimed stream drifts high.
· Oxidisable nitrogen and nutrients. Tertiary treatment targets these, but spot monitoring confirms the tower biology stays controlled.
· Microbial screening. Periodic checks limit legionella and biofilm risk, especially where the reclaimed water is stored warm or for extended periods.
· Turbidity and colour. A rapid indicator of an upstream treatment upset that should isolate the tank from the cooling loop.
Monitoring turns a variable external supply into a controllable internal reserve; without it, the tower is exposed to whatever the utility sends.
Parameter | Why it matters | Typical action on excursion |
Conductivity / TDS | Drives scaling and blowdown rate | Increase blowdown, blend with lower-TDS source |
Oxidisable N / nutrients | Tower biology and algae growth | Verify dosing, limit feed rate |
Microbial count | Legionella and biofilm risk | Disinfect, isolate from aerosolising reuse |
Turbidity | Upstream treatment upset signal | Hold tank, alert utility |
Blending With On-Site Recycle
The reclaimed tank is the blend point where municipal reclaimed water meets on-site recycled streams before cooling-tower makeup. Blending smooths supply variability and makes the best use of both sources.
· Reclaimed plus harvested or greywater recycle. On-site recycled volumes top up the reclaimed reserve during high cooling demand or when the municipal supply is constrained.
· Conductivity-weighted blend. The blend ratio is set so the combined feed stays within the tower's acceptable concentration limits, computed from each stream's TDS.
· Makeup pump set. The cooling-tower makeup pumps draw from the blended reserve, not directly from the reclaimed mains, so an interruption in municipal supply does not immediately starve the towers.
The tank therefore acts as both a buffer and a mixer: it absorbs supply swings and delivers a consistent, monitored feed to the cooling system.
Storage: Material, Finish And Variable Influent
Reclaimed water often carries higher and more variable dissolved solids than potable, so the tank lining must tolerate that chemistry without degradation. Bolted steel with a certified inert lining is the standard choice.
· GFS (glass-fused-to-steel). Enamel fired at 820–930 °C gives a smooth, chemically resistant internal skin (Ra < 0.8 µm) that withstands variable pH and conductivity and is easy to inspect.
· FBE (fusion-bonded epoxy). A documented lining for sites that require a specified coating standard and a defined chemical tolerance.
· Sealed, monitored enclosure. A secure roof, level and overflow controls, and access for cleaning keep the reserve stable between deliveries.
NSF/ANSI 61 and WRAS listings confirm the lining is acceptable for contact with water intended for non-potable reuse, which is the relevant certification for reclaimed storage even though the end use is cooling, not drinking.
Material | Internal finish | Tolerance to variable TDS | Coating documentation |
GFS bolted | Enamel, Ra < 0.8 µm | High (inert, smooth) | ISO 28765, spark test 1,500 V DC |
FBE bolted | Epoxy lining | High (rated pH range) | AWWA C550-style lining spec |
Galvanized (limited) | Zinc | Moderate | Zinc coating cert |
Sizing To Supply Contract And Demand
The reclaimed tank is sized from the utility supply agreement and the site's non-potable demand, with a band for delivery interruption. Three inputs set the volume.
4. Contractual supply rate and reliability. The maximum and typical delivery rate from the municipal reclaimed main, including any interruption history.
5. Peak non-potable demand. The combined cooling-makeup, flushing and irrigation demand over the design window.
6. Interruption buffer. The volume that carries the site through a supply stoppage or quality hold without dropping below the low-level alarm.
The resulting tank lets a variable municipal service feed a steady cooling demand, and it provides the headroom to blend on-site recycle when the reclaimed supply is short.
Project Case
A dedicated data-center reclaimed-water reference is not yet part of the delivered portfolio, so this article is written as engineering guidance rather than a project citation. The company's capability to supply large bolted non-potable and process-water reservoirs is demonstrated in adjacent sectors: overseas fire-protection programs have delivered GFS tanks up to 12,261 m³ (India, 3 tanks, 2024-06) and 1,666 m³ (Singapore, 2 tanks, 2026-01), built to the same bolted-tank standards a reclaimed water tank is engineered to. Those references evidence large-volume bolted-tank supply and QA; they are fire-protection projects, not data-center reclaimed-water installations, and are cited here only as capability context.
Center Enamel Engineering Capability
Center Enamel (Shijiazhuang Zhengzhong Technology Co., Ltd) has designed and fabricated bolted storage tanks since 2008. As the first glass-fused-to-steel (GFS) tank manufacturer in China, the company holds close to 200 enamel-related patents, produces roughly 300,000 enamel-coated steel plates a year, has completed more than 30,000 installed projects and supplies its tanks to over 100 countries. The new 150,000 m² production base was added to raise output capacity, and single tanks are supplied up to 60,000 m³. Manufacturing runs under ISO 9001 and ISO 45001, with product certification including NSF/ANSI 61, WRAS, FDA, LFGB, CE (EN 1090), ISO 28765, FM, BSCI and EUROCODE, and design referenced to AWWA D103-09, AWWA C550, NSF/ANSI 61 and WRAS where the application requires it.
For reclaimed and non-potable duty the company supplies GFS and FBE bolted tanks with sealed roofs, level and overflow controls, and access specified for variable-influent storage, and provides the coating and spark-test documentation needed for water-contact review.
Frequently Asked Questions
Q1: What is the difference between reclaimed and greywater?
A1: Reclaimed water is tertiary-treated municipal effluent delivered by a utility through a dedicated main; greywater is on-site building discharge treated at the campus. A reclaimed tank intakes the former, often blended with the latter.
Q2: Why is a dual-pipe system required?
A2: Reclaimed water must never share a main with potable supply. A dedicated, isolated non-potable ring with air-gap or backflow-protected separation prevents cross-connection and protects drinking water.
Q3: How is reclaimed water made safe for cooling towers?
A3: Through continuous inlet monitoring (conductivity, nutrients, microbial, turbidity) and blending so the combined feed stays within the tower's concentration limits; blowdown and dosing are tuned to the higher TDS feed.
Q4: How is the tank sized?
A4: By the utility supply agreement (rate and reliability) and the site's peak non-potable demand, plus an interruption buffer — not by the chilled-water or fire systems.
Q5: Why GFS for reclaimed storage?
A5: The enamel skin (Ra < 0.8 µm, fired at 820–930 °C) resists a variable, often higher-conductivity influent and is easy to inspect, suiting chemically variable stored water.
Q6: Which certification matters for reclaimed storage?
A6: NSF/ANSI 61 and WRAS listings confirm the lining is acceptable for contact with water intended for non-potable reuse; coating and spark-test records are supplied for review.
Q7: Can the tank blend with on-site recycle?
A7: Yes. The reclaimed tank is the blend point where municipal reclaimed water meets harvested or greywater recycle before cooling-tower makeup, smoothing supply and making best use of both sources.
A reclaimed water tank for a data center converts a municipal tertiary effluent service into a reliable, separated non-potable reserve — but only when the dual-pipe intake, inlet monitoring and blend logic are designed together. Keep reclaimed separate from potable by physical isolation, monitor conductivity and biology at the inlet, blend with on-site recycle to smooth supply, and size the tank to the supply contract and demand rather than to the cooling loop. Done that way, the reserve cuts potable draw without ever risking the cooling system or the drinking supply.
Talk to an Engineer
For a reclaimed water tank for a data center, send us the municipal reclaimed supply agreement (rate and reliability), the non-potable demands you want to serve, your on-site recycle streams available for blending, and any potable interface points. We will return a supply-and-demand balance with tank size, a recommended GFS or FBE tank specification with sealed roof and controls, and a backflow-protected dual-pipe layout with coating and spark-test documentation.
WhatsApp