What a Faridabad data center actually discharges every day
A 5 MW NCR site running 4 cycles of concentration can expect roughly 125–240 m³/day of cooling-tower blowdown from a ~500–800 m³/day makeup stream, with peak instantaneous flows above 20 L/s during May–June high-ambient days (Arup, 2024; Genesis Water Tech, 2024). The blowdown quality sits in the TDS 1,200–6,000 mg/L band, with suspended solids 10–50 mg/L, concentrated calcium, magnesium and silica, plus accumulated biocide, corrosion-inhibitor and scale-inhibitor residues (Genesis Water Tech, 2024). Each component matters downstream: silica and calcium carbonate set the scaling ceiling for any reverse-osmosis stage, suspended solids determine pretreatment loading, and the organic treatment chemistry determines whether a membrane will foul in weeks or run a clean CIP cycle.
Faridabad sits on the Yamuna floodplain where groundwater is over-drafted, and the Municipal Corporation of Faridabad treated-sewage network is the most realistic large alternative source for a hyperscaler. That combination pushes the design conversation away from "discharge to drain" and toward "polish and reuse as cooling-tower makeup" as the baseline pathway, with HSPCB-compliant discharge or full ZLD reserved for sites where reuse is constrained.
| Parameter | Typical range at 4 cycles | Source |
|---|---|---|
| Daily blowdown volume (5 MW NCR site) | ~125–240 m³/day | Genesis Water Tech, 2024 |
| Peak instantaneous blowdown | > 20 L/s in May–June | Arup, 2024 |
| TDS | 1,200–6,000 mg/L | Genesis Water Tech, 2024 |
| Suspended solids | 10–50 mg/L | Genesis Water Tech, 2024 |
| Key scaling species | Silica, CaCO₃, CaSO₄ | IDE Tech, 2025 |
| Treatment chemistry residues | Biocides, inhibitors, dispersants | Genesis Water Tech, 2024 |
Why Faridabad is a water-stress site, not a generic India site
India holds about 4% of global freshwater for 18% of population, and around 75% of India's data-centre capacity sits in states already classified as high or extremely high water-stress (Schneider Electric, 2026-09-29, citing the World Bank, 2026-03-19, and ETV Bharat, 2026-08-07). Haryana's NCR block, including Faridabad's industrial belt in Sector 25 and IMT Faridabad, is treated as over-exploited in Central Ground Water Board assessments; the site hydrogeologist must confirm local well yield and depth-to-water before any borewell-based makeup is committed. The 2025 Indian bulk-user rules require any site consuming more than 5,000 L/day to increase wastewater treatment and reuse, and the 2023 Bureau of Energy Efficiency District Cooling Guidelines explicitly encourage treated wastewater for cooling-tower makeup where feasible (Schneider Electric, 2026-09-29, citing AEEE and India Water Portal).
AWS has announced plans to use treated sewage water at future India data-centre sites in Mumbai and Hyderabad, a signal that hyperscalers operating in or near NCR will face the same sourcing pressure (BusinessToday, 2026-08-08, cited in Schneider Electric, 2026-09-29). State policy is moving in the same direction: Rajasthan's 2025 data-centre policy already incorporates wastewater recycling, ZLD and rainwater harvesting, and Haryana's consent officers will read a Faridabad CTBD design against that benchmark even if state text lags by a quarter or two (Schneider Electric, 2026-09-29, citing the Rajasthan sewerage policy, 2025).
The treatment train: side-stream filtration, UF, RO, and when to add MVC or ZLD
A practical CTBD train for Faridabad runs in five steps, and the first three carry the design whether the site is reusing, discharging or building toward ZLD.
Step 1 — Side-stream filtration. Sized at 1–5% of circulation flow, with installed cost in the US$50,000–200,000 band for typical data-centre installations, this stage cuts suspended solids in the blowdown to a level a downstream membrane can accept (Genesis Water Tech, 2024). A self-cleaning screen ahead of the basin prevents debris accumulation without backwash downtime.
Step 2 — Ultrafiltration. A PVDF ultrafiltration system at 0.01–0.1 μm pore size, operating at 10–30 psi with 90–95% recovery and chemical cleaning every 1–3 months, is the robust pretreatment ahead of RO (Genesis Water Tech, 2024). Spec the UF on the blowdown stream, not the full circulation loop, to control membrane capex; turbidity handling up to 300 ppm with automatic backwash and air scour is the operating window to verify with the vendor.
Step 3 — Brackish-water reverse osmosis. An industrial reverse osmosis system sized at a conservative 75–80% local recovery, because beyond that, silica, calcium carbonate and calcium sulfate scaling become unmanageable on a conventional BWRO (IDE Tech, 2025). Permeate TDS lands at 10–50 mg/L — directly reusable as cooling-tower makeup — and OpEx for a 50,000 GPD train is in the US$1.50–3.00 per 1,000 gal band, with installed cost US$250,000–500,000 (Genesis Water Tech, 2024).
Step 4 — Push recovery higher with controlled precipitation or MVC. When cycles of concentration must climb above ~6, the right step is either IDE Tech's MAXH₂O-style fluidized-bed reactor, which removes silica, CaCO₃ and other scaling salts as dense pellets and runs a real industrial reference at ~95% recovery with permeate silica ~1 mg/L (IDE Tech, 2025), or a mechanical vapor compression evaporator producing distillate below 10 mg/L TDS at 95–98% recovery and 15–25 kWh per 1,000 gallons (Genesis Water Tech, 2024).
Step 5 — Full ZLD only when discharge is prohibited. Combine RO/MVC with a crystallizer to reach 95–99% overall recovery, at US$3–8M CapEx and US$5–15 per 1,000 gal OpEx (Genesis Water Tech, 2024). Treat this as a "design to the direction of policy" choice rather than a baseline — for a Faridabad hyperscaler in 2026 it is a hedge, not a default.
| Stage | Function | Operating window | CapEx band (US$) | Source |
|---|---|---|---|---|
| Side-stream filtration | Cut SS, enable higher cycles | 1–5% of circulation flow | 50,000–200,000 | Genesis Water Tech, 2024 |
| UF (PVDF) | RO pretreatment | 10–30 psi, 90–95% recovery | Vendor quote required | Genesis Water Tech, 2024 |
| BWRO | Dissolved solids removal | 75–80% recovery, 150–400 psi | 250,000–500,000 (50,000 GPD) | Genesis Water Tech, 2024 |
| Controlled precipitation / MVC | Push recovery past 80% | ~95% recovery, distillate <10 mg/L TDS | 1,000,000–3,000,000 (10–30 k GPD) | Genesis Water Tech, 2024; IDE Tech, 2025 |
| Full ZLD (RO + MVC + crystallizer) | No liquid discharge | 95–99% overall recovery | 3,000,000–8,000,000 | Genesis Water Tech, 2024 |
Reuse, discharge or ZLD: a decision matrix for a Faridabad site
Pick a pathway from local facts, not from a generic data-centre article. Reuse as cooling-tower makeup is the highest-value option where makeup water is expensive or restricted, where discharge fees apply, and where cycles of concentration are constrained by silica and hardness — typical 60–85% recovery on this duty (Genesis Water Tech, 2024). For most Faridabad sites, where groundwater on the Yamuna floodplain is over-drafted and treated sewage supply from MC Faridabad is becoming available, reuse is the default.
Discharge compliance is the right answer only where the receiving sewer or drain under the Haryana State Pollution Control Board consent accepts the volume and TDS, and where a robust side-stream filtration plus softening train can meet consent limits without an RO. ZLD or partial ZLD (80–90% volume reduction) is justified when discharge is effectively prohibited, when the site sits inside a notified over-exploited groundwater block, or when hyperscaler water-positive targets require near-closed loops.
When the site has access to Municipal Corporation of Faridabad treated sewage — the same model AWS has announced for Mumbai and Hyderabad (BusinessToday, 2026-08-08) — the right design often pairs an MBR membrane bioreactor on the sewage side with a UF+RO train on the blowdown side; the two streams share polishing but have different upstream biology and different CIP chemistry.
| Pathway | Trigger condition (Faridabad) | Treatment core | Typical recovery |
|---|---|---|---|
| Reuse as CT makeup | Makeup restricted, discharge fees, silica/hardness cap on cycles | UF + BWRO (+ optional MVC) | 60–85% |
| Discharge to HSPCB consent | Sewer/drain accepts TDS and volume, softening sufficient | Side-stream filtration + softening | Site-specific |
| ZLD / partial ZLD | Discharge prohibited, over-exploited block, water-positive target | BWRO + MVC + crystallizer | 95–99% |
Sizing a real Faridabad train: a worked example for a 5 MW NCR site
Assume 5 MW IT load, 500–800 m³/day makeup (confirm with the chiller OEM, since IT load alone does not set this), 4 cycles of concentration, which puts blowdown at 125–240 m³/day with peak flows above 20 L/s in the May–June window (Arup, 2024; Genesis Water Tech, 2024). The side-stream filter is sized at 1–5% of circulation flow — derive the circulation rate from chiller heat-rejection duty — and the UF is sized on the blowdown stream only, not the full loop, to keep membrane capex proportional to the stream that actually needs polishing.
Size the BWRO at 75–80% local recovery as a conservative baseline (IDE Tech, 2025). If cycles of concentration must climb to 6 or more to ease freshwater draw, reserve plot area and power for an MVC evaporator on the RO concentrate from day one, even if it ships in phase 2. Reserve footprint for chemical dosing skids, an RO CIP loop, a brine/concentrate storage tank sized for at least 24 hours of operation, and a sludge dewatering bay — a plate and frame filter press is the standard spec for the clarifier underflow, paired with an automatic chemical dosing skid for coagulant and polymer.
What it costs in India, and the inputs you must send to a supplier
Use the Genesis Water Tech (2024) US-dollar bands as the engineering anchor, then re-quote in INR with an Indian EPC rather than assuming a $/₹ conversion. For reference, side-stream filtration sits in the US$50,000–200,000 band, a 50,000 GPD BWRO is US$250,000–500,000 installed, MVC sits in the US$1,000,000–3,000,000 band for 10,000–30,000 GPD, and full ZLD runs US$3–8M CapEx with US$5–15 per 1,000 gal OpEx (Genesis Water Tech, 2024). Indian EPC pricing depends on civil works for a packaged skid on a Faridabad site with a high water-table, HSPCB consent fees, and the cost of treated-sewage offtake if that pathway is chosen — none of which the US benchmarks capture.
The inputs the EPC will need before sizing a quote: makeup water analysis (TDS, hardness, silica, chloride), blowdown chemistry across at least one summer and one monsoon quarter, target cycles of concentration, the HSPCB consent conditions, peak ambient wet-bulb temperature, and the operator's reuse-versus-discharge-versus-ZLD preference. On the consumables side, verify membrane element supply for the RO and UF membrane elements and pretreatment media for the multi-media filter through Indian channel partners, not on US lead times.
The highest-ROI operational lever in India is matching the cooling-water treatment program — biocide, scale inhibitor, dispersant — to a membrane-compatible chemistry so that blowdown can be polished, not just dumped. A program that lets a chromate-era or high-phosphate legacy chemistry reach the RO will multiply cleaning frequency and shorten membrane life, regardless of how well the skid is built.
| Line item | US$ benchmark (Genesis 2024) | INR note for Faridabad |
|---|---|---|
| Side-stream filtration | 50,000–200,000 | Re-quote in INR; civil works on high water-table site add to landed cost |
| UF (PVDF) system | Vendor quote required | Re-quote; verify turbidity and CIP duty with vendor |
| BWRO, 50,000 GPD | 250,000–500,000 installed | Re-quote; imported membrane element FX exposure |
| MVC, 10–30 k GPD | 1,000,000–3,000,000 | Re-quote; power cost dominates OpEx in NCR |
| Full ZLD (RO + MVC + crystallizer) | 3,000,000–8,000,000 CapEx; 5–15 per 1,000 gal OpEx | Re-quote; treat as a directional hedge, not a default |
Frequently Asked Questions
How much does a data center blowdown RO system cost in India?
A 50,000 GPD brackish-water RO train treating cooling-tower blowdown is in the US$250,000–500,000 installed band as a US benchmark, with OpEx at US$1.50–3.00 per 1,000 gallons (Genesis Water Tech, 2024). Indian EPC pricing for a Faridabad site depends on civil works for the packaged skid on a high water-table plot, HSPCB consent fees, and the treated-sewage offtake cost if that pathway is chosen — none of which the US figure captures. The right action is to send the inputs listed in the sizing section to two or three Indian EPCs and compare landed quotes, rather than assume a $/₹ conversion.
Is ZLD mandatory for a data center in Faridabad in 2026?
No. The 2025 Indian bulk-user rules require sites consuming more than 5,000 L/day to increase wastewater treatment and reuse, and the 2023 BEE District Cooling Guidelines encourage treated wastewater for cooling-tower makeup, but neither instrument mandates full ZLD today (Schneider Electric, 2026-09-29, citing AEEE and India Water Portal). Full ZLD is a "design to the direction of policy" choice that becomes justified when discharge is effectively prohibited, when the site sits inside a notified over-exploited block, or when hyperscaler water-positive targets require near-closed loops — otherwise reuse as cooling-tower makeup is the higher-value baseline.
Can cooling-tower blowdown in Faridabad be reused as cooling-tower makeup?
Yes, and it is the highest-value pathway on most Faridabad sites. A UF + BWRO train typically achieves 60–85% recovery on this duty, with permeate at 10–50 mg/L TDS that can be blended back into the cooling loop (Genesis Water Tech, 2024). The limiting chemistry is silica and hardness, not biology — biology is handled by the UF stage and a compatible cooling-water treatment program.
What flow rate of blowdown does a 5 MW NCR data center generate?
A 5 MW NCR site on 4 cycles of concentration and ~500–800 m³/day makeup generates roughly 125–240 m³/day of blowdown, with peak instantaneous flows above 20 L/s during May–June high-ambient days (Arup, 2024; Genesis Water Tech, 2024). Confirm the makeup number with the chiller OEM, since IT load alone does not set the cooling duty, and the actual figure will move with ambient wet-bulb and PUE.
Which HydropureWater products are typically specified for a CTBD train?
The typical bill of material for a Faridabad CTBD reuse train is a PVDF ultrafiltration system as RO pretreatment, an industrial reverse osmosis system as the dissolved-solids removal step, a multi-media filter ahead of the UF for turbidity and sediment, an automatic chemical dosing skid for antiscalant and CIP chemistry, a plate and frame filter press for clarifier underflow, and — if MC Faridabad treated sewage is brought in — an MBR membrane bioreactor on the sewage side. Each plays a defined process role; none is a standalone answer.
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