Why Shiraz is a water-stressed data-center site in 2026
Industry analyses cited by IDE Tech point to the mid-2020s as a turning point, when water availability, treatment capacity, and regulatory scrutiny will directly influence where data centers can be built and how they operate, and water demand across the sector is expected to intensify into 2026 and beyond (IDE Tech, 2026). For a 100 MW facility this translates into total water demand of up to 2 million liters per day, comparable to the daily use of thousands of households (IDE Tech, 2026).
In Fars Province, the Kor River basin has been under recurring drought stress, and any hyperscale operator drawing millions of liters per day from municipal or surface intakes is already in direct competition with agriculture, households and other industrial users. The Iran Department of Environment regulates industrial effluent, so even a well-run site cannot assume unlimited discharge capacity. The defensible starting point for any Shiraz build is therefore to design for blowdown reuse from day one and to confirm the actual intake source (Kor River, qanat well, or blended municipal supply), local effluent limits, and the Khak-e-Sefid or other applicable discharge constraints with the operator's environmental consultant before any membrane or thermal stage is specified.
A second framing point comes from the ITIF review of data-center cooling technology, which observes that wet-recirculating cooling is still the dominant thermal-management architecture for high-density AI loads and that wet towers evaporate 3–5% of circulating flow (ITIF, July 2026). Closed-loop direct-to-chip liquid cooling, which Microsoft has demonstrated at zero direct cooling-water consumption, and warmer liquid loops paired with external dry coolers are technically proven (ITIF, July 2026), but they are not the baseline for a retrofit on an existing wet-tower campus. For most greenfield Shiraz builds relying on evaporative cooling, blowdown handling is non-negotiable.
The two wastewater streams a Shiraz data center actually has to treat
Most scoping errors on hyperscale sites start with treating only cooling-tower blowdown and forgetting the domestic side. A Shiraz data center typically generates two clearly separate wastewater streams that have to be designed for in parallel.
Stream 1 — cooling-tower blowdown (CTBD). Brackish, enriched with silica, calcium, magnesium and alkalinity, and loaded with treatment-chemical residues from biocides, corrosion and scale inhibitors. Genesis Water Technologies reports that suspended solids in blowdown typically range from 10–50 mg/L, made up of corrosion products, biofilm fragments and airborne particulates, and that CTBD is dominated by elevated total dissolved solids (TDS) at 4–8× makeup water, ranging from 1,200 to 6,000 mg/L depending on cycles of concentration and source water quality (Genesis Water Technologies, 2025). At 4 cycles of concentration, the same source notes that a typical data-center cooling tower loses roughly 25–30% of makeup water to blowdown, so a site using 10 million gallons per month discharges 2.5–3 million gallons (Genesis Water Technologies, 2025).
Stream 2 — domestic and process wastewater. Canteen, restrooms, dormitories, humidification bleed-off, and any on-site laboratory or generator wash water. These are BOD-, COD- and pathogen-dominated, and they are regulated under the same Iran Department of Environment discharge framework as CTBD. Because total site water demand at hyperscale can reach 2 million liters per day (IDE Tech, 2026), even a small sanitary bleed-off generates a meaningful stream that the design must accommodate. Most Iranian sites therefore run a separate MBR train for the domestic-side stream alongside a dedicated RO/MVC train for CTBD, both discharging or reusing to a common outfall under the 2026 industrial effluent discharge guidelines.
Cooling-tower blowdown chemistry in Fars Province — what the design has to handle
The design baseline for the cooling-side train is the chemistry of the blowdown stream at the point it leaves the cooling tower basin. Genesis Water Technologies reports blowdown TDS of 1,200–6,000 mg/L, scaling minerals (calcium, magnesium, silica and alkalinity), and treatment-chemical residues that include legacy chromates and high-phosphate chemistries in older systems (Genesis Water Technologies, 2025). Suspended solids typically run 10–50 mg/L, and these must be polished below 10–15 microns before any RO or NF membrane (Genesis Water Technologies, 2025). At 4 cycles of concentration, a 10 million gallon/month site discharges 2.5–3 million gallons of blowdown per month (Genesis Water Technologies, 2025), which is the volumetric baseline for sizing the recovery train. IDE Tech adds that conventional brackish-water RO (BWRO) is usually limited to 75–80% recovery before scaling becomes unmanageable, and that pushing recovery higher with traditional designs usually requires additional stages, booster pumps and recirculation loops (IDE Tech, 2026).
For a Shiraz site, the additional local condition is that intake water from the Kor River basin is generally hard surface water, blended in many cases with qanat well supply. The design must request the operator's actual intake analysis (Ca, Mg, SiO₂, alkalinity, Cl, SO₄) before any final sizing decision; assuming a "typical" Fars profile without that analysis is a common cause of membrane fouling and thermal-stage undersizing.
| Parameter | Typical blowdown envelope (Genesis Water Technologies, 2025; IDE Tech, 2026) | Design implication |
|---|---|---|
| TDS | 1,200–6,000 mg/L (4–8× makeup) | Sets RO feed pressure and concentrate disposal volume |
| Suspended solids | 10–50 mg/L | Must be polished to <10–15 µm before RO/NF |
| Cycles of concentration | 3–6 typical, 4 baseline | Blowdown ~25–30% of makeup at 4 cycles |
| Dominant scalants | Silica, CaCO₃, CaSO₄ | Caps conventional BWRO at 75–80% recovery |
| Treatment chemicals | Biocides, inhibitors, legacy chromate/phosphate | Drives pretreatment chemistry and biocide-neutralization step |
Reference treatment train for a Shiraz hyperscale site in 2026
The following train can be copied directly into a P&ID. It is a conservative, chemistry-aware stack sized for a CTBD-dominated site with a parallel domestic-side train.
- Stage 1 — Intake screening and multi-media filtration. A multi-media filter for raw-water intake with automatic backwash brings turbidity and Silt Density Index down to RO-protection levels (Genesis Water Technologies, 2025).
- Stage 2 — Side-stream or dedicated UF pretreatment. A UF pretreatment ahead of RO at 0.01–0.1 µm cuts suspended solids, bacteria and colloidal fouling precursors. UF operates at 10–30 psi with 90–95% recovery and permeate SDI consistently below 3 (Genesis Water Technologies, 2025).
- Stage 3 — Antiscalant-dosed reverse osmosis. An industrial RO system for cooling-tower blowdown at 150–400 psi and 50–85% recovery, with feed pre-filtered to <10–15 µm and pH-adjusted, produces permeate of 10–50 mg/L TDS suitable for blending back as cooling-tower makeup (Genesis Water Technologies, 2025). Automatic antiscalant and biocide dosing protects the membranes from CaCO₃, CaSO₄ and silica scaling; legacy chromate and high-phosphate cooling-water regimes should be phased out before the recovery train is started (Genesis Water Technologies, 2025).
- Stage 4 — Optional NF brine polishing. Where hardness rather than total TDS is the limiting reuse parameter, an NF stage at 75–150 psi and 70–85% recovery produces permeate TDS at 30–50% of feed and selectively removes divalent ions (Genesis Water Technologies, 2025).
- Stage 5 — Concentrate management. Either direct disposal under DOE permit, or MVC evaporation at 95–98% recovery producing distillate <10 mg/L TDS (Genesis Water Technologies, 2025).
- Decision point — ZLD or partial ZLD. If the site is targeting near-zero liquid discharge, add a crystallizer after MVC to convert the 20–30% TDS brine into a manageable solid cake (Genesis Water Technologies, 2025).
- Domestic-side parallel train. An MBR train for the domestic-side stream (or an A/O package plant) handles BOD/COD and pathogen reduction before blending with any cooling-tower-side treated stream or separate disposal.
Reuse, discharge compliance or zero liquid discharge — the 2026 decision matrix
The engineering choice collapses into a business-and-regulatory decision once the train is on paper. Genesis Water Technologies frames three primary strategies with very different economics (Genesis Water Technologies, 2025): cooling-tower makeup reuse, which typically achieves 60–85% recovery and directly reduces freshwater intake and discharge volumes; discharge compliance, where the economic justification is avoided discharge fees of $5–15 per 1,000 gallons and where some jurisdictions have implemented TDS limits below 1,500 mg/L that effectively prohibit discharge of concentrated blowdown without treatment; and zero liquid discharge, which combines membrane concentration, thermal evaporation and crystallization to achieve 95–99% overall water recovery with solid waste under 1% of original blowdown volume, at CAPEX of $3–8 million and OPEX of $5–15 per 1,000 gallons (Genesis Water Technologies, 2025).
For a typical Shiraz hyperscale site, the practical middle ground is partial ZLD — concentrating blowdown to reduce discharge volume by 80–90% via RO + MVC, with the remaining concentrated brine sent to deep well injection, hauling to an approved disposal facility, or periodic discharge under special permit (Genesis Water Technologies, 2025). Closed-loop direct-to-chip liquid cooling, which Microsoft has demonstrated at zero direct cooling-water consumption (ITIF, July 2026), is worth modeling as an alternative at greenfield sites even though it is not the baseline for a retrofit on an existing wet-tower campus.
| Strategy | Water recovery | CAPEX (Genesis Water Technologies, 2025) | OPEX (per 1,000 gal) | Fits when… |
|---|---|---|---|---|
| Cooling-tower makeup reuse (RO) | 60–85% | $250,000–500,000 for a 50,000 GPD RO system | $1.50–3.00 | Freshwater cost or discharge fees are meaningful; reuse water has a clear demand |
| Discharge compliance (TDS polishing) | Set by permit | Side-stream filtration $50,000–200,000 at 1–5% of circulation | Driven by avoided discharge fees of $5–15 per 1,000 gal | Local TDS limit <1,500 mg/L; reuse demand is limited |
| Partial ZLD (RO + MVC, brine haul-off) | 80–90% volume reduction | MVC $1–3 million for 10,000–30,000 GPD | Between reuse and full ZLD | Severe water stress; brine can be hauled or deep-well injected |
| Full ZLD (RO + MVC + crystallizer) | 95–99% | $3–8 million | $5–15 | Discharge is not permitted under any circumstances |
| Closed-loop direct-to-chip | ~100% (no evaporation) | Site-specific; not a "retrofittable" treatment train | Driven by chip and rack design | Greenfield AI builds; not the baseline for wet-tower retrofits (ITIF, July 2026) |
Parameter and cost table set for a 2026 Shiraz data-center build
The numeric backbone of the design is concentrated below. All values are taken from Genesis Water Technologies (2025); Iran-specific import duty, port-handling at Bandar Abbas, and inland transport to Shiraz must be added on top of the US-benchmark figures by the procurement team, since these are not captured in the source data.
| Stage | Operating window (Genesis Water Technologies, 2025) | CAPEX band | OPEX band |
|---|---|---|---|
| CTBD envelope | TDS 1,200–6,000 mg/L; SS 10–50 mg/L; 3–6 cycles | — | — |
| Side-stream filtration | 1–5% of circulation flow | $50,000–200,000 | Solids disposal only |
| UF | 10–30 psi; 0.01–0.1 µm; 90–95% recovery | Per train size | Cleaning every 1–3 months |
| RO (on blowdown, 50,000 GPD) | 150–400 psi; 50–85% recovery; permeate 10–50 mg/L TDS | $250,000–500,000 installed | $1.50–3.00 per 1,000 gal |
| NF (brine polishing) | 75–150 psi; 70–85% recovery; permeate TDS 30–50% of feed | Per train size | Lower than RO |
| MVC (10,000–30,000 GPD) | 95–98% recovery; distillate <10 mg/L TDS; 15–25 kWh per 1,000 US gal | $1–3 million | Energy-dominated |
| Full ZLD | 95–99% overall recovery; solid waste <1% of blowdown | $3–8 million | $5–15 per 1,000 gal |
RO and UF membrane replacement elements and automatic antiscalant and biocide dosing are recurring spend items that should be sized for at least 12 months of operation before the first shutdown.
Procurement, compliance and commissioning checklist for Shiraz
The engineering is only half the FID package. The project manager needs a defensible compliance and logistics path, and the source data only supports the technical half of that picture — Iran-specific fees, duties, and lead times must be confirmed with the operator's local agent.
- Compliance pathway. Confirm the applicable Iran Department of Environment effluent limits with the operator's environmental consultant and design the discharge envelope around the strictest expected limit (typically expressed as TDS, BOD, COD, total phosphorus and residual chlorine). Cross-check against the 2026 industrial effluent discharge guidelines.
- Sourcing pathway. Confirm skid delivery terms (typically FOB Shanghai or Ningbo with containerized shipment to Bandar Abbas and road transport to Shiraz), pre-commissioning at the supplier's workshop, and on-site commissioning by supplier engineers — these terms materially affect schedule and CAPEX, and the Iran-specific uplift must be requested from the freight forwarder, not assumed.
- Chemical compatibility. Blowdown-recovery chemistry must be matched to the cooling-water treatment program. Legacy chromate and high-phosphate regimes can foul membranes and should be phased out before the recovery train is started (Genesis Water Technologies, 2025).
- Spare-parts plan. Stock RO and UF membrane replacement elements, antiscalant, cleaning chemicals and critical dosing pumps for at least 12 months of operation, sourced through the original supplier or a compatible-element vendor. Water-treatment parts, valves and media should be specified in the same procurement lot to avoid a second customs clearance.
- Monitoring. Specify online conductivity, pH, ORP and turbidity on the RO feed and permeate, plus monthly silica and hardness checks on blowdown to catch scaling risk early. A UV sterilizer on the reuse line is a low-cost insurance policy for any stream returned to the cooling tower.
Frequently Asked Questions
What CAPEX envelope should a 2026 Shiraz data-center blowdown-recovery train be budgeted at?
For a 50,000 GPD RO skid on blowdown, Genesis Water Technologies reports an installed CAPEX of $250,000–500,000 with OPEX of $1.50–3.00 per 1,000 gallons; an MVC stage sized at 10,000–30,000 GPD adds $1–3 million, and a full ZLD package of RO + MVC + crystallizer lands at $3–8 million (Genesis Water Technologies, 2025). The buyer should request an Iran-specific uplift covering import duty, Bandar Abbas port handling, inland transport to Shiraz, and supplier commissioning, since these are not captured in the US-benchmark figures.
What is the practical compliance risk for a hyperscale site discharging treated blowdown in Fars Province?
Some jurisdictions have implemented TDS limits below 1,500 mg/L that effectively prohibit discharge of concentrated blowdown without treatment, and direct discharge fees in water-stressed regions now exceed $5–15 per 1,000 gallons (Genesis Water Technologies, 2025). The buyer should request the operator's environmental consultant to confirm the specific Iran Department of Environment effluent envelope for the discharge point and design the RO or RO + MVC train around the strictest expected limit rather than a generic guideline.
What lead time and logistics terms should be specified for a treatment skid shipped to Shiraz?
Source data does not publish a lead-time figure for Iran-bound skids. The buyer should request written confirmation from the supplier of FOB Shanghai or FOB Ningbo terms, containerized shipment to Bandar Abbas, road transport to Shiraz, workshop pre-commissioning, and on-site commissioning by supplier engineers, and should write those terms into the purchase contract because they materially affect both schedule and the final CAPEX number.
How does a Shiraz blowdown train compare to a Vietnam or Serbia hyperscale design?
The core chemistry envelope (1,200–6,000 mg/L TDS, 50–85% RO recovery, 95–98% MVC recovery) is common across hyperscale sites, but the discharge regime and water-stress weighting differ by jurisdiction. For regional comparisons, see the Bien Hoa data-center blowdown guide, the Da Nang data-center blowdown guide, and the Belgrade data-center blowdown guide.
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