Determine the wastewater streams before choosing equipment
A data center in Anyang-si should separate cooling-tower blowdown, cooling condensate, sanitary sewage, softener or reverse-osmosis backwash, membrane or filter backwash, and equipment-cleaning wastewater before selecting a treatment train. RSP Engineers identifies cooling blowdown as the usual principal process-wastewater stream, with sanitary waste typically minor by comparison. The engineering decision is not simply which equipment to buy: each stream needs a measured flow, chemistry characterization, temperature assessment and confirmed destination. Condensate should not be combined with blowdown until its chemistry, temperature, variability and local receiving rules are confirmed. For each candidate stream, record suspended solids, oil and grease, temperature, pH, dissolved solids, conductivity and the chemicals used in cooling or cleaning. The DAF pretreatment for cooling blowdown should be evaluated only after that data identifies a flotation duty.
| Stream | Initial characterization | Decision gate |
|---|---|---|
| Cooling-tower blowdown | Flow, temperature, suspended solids, oil and grease, pH, dissolved solids, conductivity, cooling chemicals | Confirm sewer permit, reuse target or other receiving route |
| Cooling condensate | Flow variability, temperature, pH, conductivity and treatment-chemical carryover | Confirm whether combination with another stream is permitted and technically suitable |
| Sanitary sewage | Measured flow and local connection or pretreatment requirements | Keep on the applicable sanitary-sewer route |
| Softener, RO, membrane or filter backwash | Flow, salinity, chemicals, temperature and backwash frequency | Confirm segregation, treatment and disposal route |
| Equipment-cleaning wastewater | Flow, pH, oil and grease, suspended solids, detergents and cleaning chemicals | Do not combine with sanitary or cooling streams without confirmation |
Build a measured water balance for Anyang-si
The design flow for blowdown must come from the site’s measured water balance, not a generic percentage or another facility’s operating profile. Rasheed Ahmad’s March/April 2024 Civil Engineering article describes the ASCE method: assess freshwater and alternative supplies, the cooling system, reclaimed water, and treatment or discharge options together. The same source cites a relationship in which blowdown is 25% of makeup-water volume at four cycles of concentration and 20% at six cycles. That is a five-percentage-point, or 20%, reduction in blowdown volume—not a 50% reduction. The relationship is a design relationship for the assumed operating condition, not a substitute for metering.
Collect average and peak makeup flow, measured blowdown flow, evaporation, cycles of concentration, flowmeter records, chemical additions, operating schedules, seasonal profiles, treatment recovery and future expansion. Ahmad also reports that an American Southeast facility was initially designed around 20%–30% of total water supplied and installed a flowmeter because actual discharge was difficult to predict. That example demonstrates why a generic estimate can diverge from measured discharge. It does not establish an Anyang-si flow. A keyword-derived flow, another city’s data center or a modular equipment range cannot become the Anyang-si design basis. The data-center cooling blowdown treatment methodology provides a useful comparison, but local measurements must still control the equipment sizing.
| Water-balance input | Use in the Anyang-si basis of design | Acceptable evidence |
|---|---|---|
| Makeup water | Average, peak, source and operating schedule | Site meter records |
| Blowdown | Measured average and peak discharge | Calibrated flowmeter data |
| Evaporation | Reconciles water entering and leaving the cooling system | Site calculation and operating data |
| Cycles of concentration | Sets the chemical concentration basis | Cooling operating record |
| Treatment recovery | Determines reuse output and concentrate quantity | Pilot or supplier guarantee supported by site chemistry |
Choose the discharge route before selecting a treatment train
The enforceable treatment requirement follows the receiving route, so the receiving point must be confirmed with Anyang-si and the relevant sewer authority before equipment is ordered. For a sewer route, obtain the applicable industrial-user discharge permit and submit the expected cooling chemistry for review; final limits and discharge points cannot be inferred from a general treatment list. South Korea’s Water Quality Conservation Act is administered by the Ministry of Environment with regional enforcement, while direct coastal discharge may also engage the Marine Environment Management Act, according to the 2026 HydropureWater Ansan guide. A direct coastal route therefore needs a separate legal and receiving-condition review.
Temperature is a separate design issue because hot blowdown can affect receiving biological treatment. Cooling or holding tanks are possible responses, but they are justified only after the confirmed temperature envelope and sewer operating conditions are known. Sewer compliance also does not establish suitability for cooling makeup: corrosion, scaling, microbial control and monitoring remain separate reuse requirements. Conversely, reusable water that bypasses the sewer still needs controlled handling and monitoring. The plate-and-frame filter press should be considered only if the selected process generates sludge that requires dewatering and a confirmed disposal route.
| Route | Authority or receiving-system action | Treatment consequence |
|---|---|---|
| Municipal sewer | Obtain industrial-user discharge permit; submit expected chemistry | Define pretreatment and monitoring against authority-confirmed limits |
| Cooling-water reuse | Define the internal reuse quality and handling plan | Establish the required pretreatment and advanced-treatment sequence |
| Direct coastal discharge | Confirm applicable marine requirements and receiving conditions | Develop a route-specific permit and treatment basis |
Match pretreatment to the contaminants and receiving limits
Pretreatment should be selected from measured contaminants and the receiving requirement, not from a catalogue of available technologies. Media filtration or dissolved air flotation may be evaluated for suspended solids, colloids, oil and grease, and floating material when influent data supports the duty. A DAF unit is appropriate only if the influent supports flotation and the clarified water meets the next process or permit requirement. HydropureWater’s catalog range is 4–300 m³/h across 13 standard models; these are feasibility references, not an Anyang-si sizing result. When flotation is justified, the DAF pretreatment for cooling blowdown should be compared with filtration using the same measured feed and required outlet quality.
Do not install a cooling tank merely because it appears in a generic pretreatment list. Use one only if the confirmed temperature envelope and sewer operating conditions justify it. Automatic chemical dosing may be needed for pH adjustment, coagulation, flocculation or another defined chemical-control duty; the automatic chemical-dosing system should be selected against confirmed chemistry and chemical inventory. Oil-and-grease, suspended-solids and colloid removal should precede advanced reuse equipment. If the process generates sludge, include dewatering, handling and disposal rather than transferring the problem downstream. The plate-and-frame filter press is a candidate only when residual sludge characteristics and the disposal route support it.
| Measured problem | Potential pretreatment | Selection condition |
|---|---|---|
| Suspended solids, colloids or floating material | Media filtration or DAF | Influent data supports the duty and clarified water meets the next requirement |
| Oil and grease | DAF or another confirmed oil-removal process | Measured loading and required effluent quality justify the method |
| Temperature above the confirmed receiving envelope | Cooling or holding arrangement | Authority or sewer operating conditions require heat management |
| pH or coagulation demand | Automatic chemical dosing | Influent chemistry and chemical-control objective are confirmed |
| Separable treatment sludge | Dewatering | Sludge quantity, characteristics and disposal destination are known |
Build a separate treatment path for sewage and reuse
Sanitary sewage should remain on the applicable local sewer path after the connection and any required pretreatment conditions are confirmed. Equipment-cleaning wastewater, backwash streams and condensate should remain segregated until their chemistry and permitted destinations are established. This separation avoids treating sanitary flow as industrial blowdown or sending concentrated cooling chemicals into a biological route that was never assessed for them.
For a fully bundled wastewater and reuse project, an MBR may be considered where the required effluent standard and site footprint justify a membrane bioreactor. HydropureWater’s MBR catalog covers 10–2,000 m³/day, while the WSZ underground integrated sewage-treatment option covers 1–80 m³/h; both ranges remain catalogue capabilities rather than Anyang-si design flows. The WSZ underground integrated sewage treatment system is relevant where decentralized sanitary treatment is required and measured duty supports it. The MBR integrated wastewater treatment system should be compared using the confirmed effluent objective and footprint. Operators must regularly sample treated wastewater, use certified-laboratory analysis and submit results to the permitting authority, as stated in the 2026 HydropureWater Ansan guide.
Use UF and RO only for confirmed cooling-water reuse
UF should precede RO when treated blowdown will become cooling makeup: UF provides the particulate barrier, and industrial RO removes dissolved solids. This sequence is also specified in the referenced 2026 guide; it should not be reversed. Sewer compliance does not prove that effluent is suitable for reuse, and reuse does not remove the need for controlled handling and monitoring. The UF pretreatment for cooling-water reuse must be selected against the confirmed source chemistry and the downstream RO feed requirement.
HydropureWater’s hollow-fiber UF systems cover 2,000–40,000 L/h, use 0.03 μm PVDF membranes, accept turbidity up to 300 ppm, and provide automatic backwash and air scour. These are catalogue limits, not an Anyang-si sizing result. HydropureWater’s industrial RO systems state permeate recovery of up to 95%, but project recovery must be verified against source chemistry, concentrate handling and reuse demand. Before selecting either capacity, define the required cooling-makeup quality, treatment recovery, redundancy, monitoring and future expansion. The industrial RO blowdown-reuse system should be priced and guaranteed against those project inputs.
| Reuse stage | Primary function | Design basis required |
|---|---|---|
| Confirmed pretreatment | Remove oil and grease, suspended solids and colloids | Measured influent, required outlet quality and sludge route |
| UF | Provide a particulate barrier before RO | Flow, feed turbidity, recovery, backwash and redundancy |
| Industrial RO | Remove dissolved solids | Source chemistry, target cooling-makeup quality and concentrate handling |
| Reuse controls | Protect cooling system and confirm quality | Monitoring, chemical control, operating response and expansion plan |
Convert the strategy into a procurement and approval scope
Issue the equipment package only after the basis of design identifies source-water chemistry, the cooling programme, average and peak flows, measured blowdown, evaporation, cycles of concentration, treatment recovery, redundancy and expansion needs. Require each bidder to state its design flow, influent limits, treated-water guarantee, recovery, chemical consumption, sludge generation, controls, monitoring and utility requirements separately. A nominal catalogue capacity is not an offer unless it is tied to those project inputs.
Price the complete system: pretreatment, pumps, tanks, justified heat management, instrumentation, chemical storage, sludge handling, controls, commissioning and ongoing certified-laboratory sampling. Compare alternatives against the same confirmed discharge or reuse duty and receiving requirements, not against headline capacity. Use the permit application, sampling plan and authority correspondence as procurement milestones because receiving-route confirmation can change the treatment train. The treatment-system parts and ancillary-equipment scope should identify valves, filter media and related items against those guaranteed process and monitoring requirements.
| Procurement milestone | Required decision or document | Release condition |
|---|---|---|
| Stream inventory | Measured stream list and initial chemistry | No uncharacterized stream enters the combined design |
| Water balance | Average and peak flows, evaporation, cycles and expansion basis | Equipment sizing is tied to measured site demand |
| Route confirmation | Authority correspondence and applicable permit | Final limits and discharge point are known |
| Treatment selection | Process comparison and solids balance | Each unit has a defined contaminant-removal duty |
| Supplier offer | Guarantees, consumables, controls, utilities and monitoring | All bidders use the same basis of design |
| Commissioning | Acceptance tests and certified-laboratory sampling plan | Permit and operating obligations are incorporated |
Frequently Asked Questions
How much should an Anyang-si data center budget for cooling-blowdown treatment?
No defensible price can be calculated from catalogue capacity or a generic blowdown percentage. The request for quotation should include measured average and peak flows, source and blowdown chemistry, temperature, cooling programme, discharge or reuse route, treatment recovery, sludge route, monitoring and future expansion. Without those inputs, any budget is only an equipment allowance, not an installed-treatment estimate.
Should a data center in Anyang-si choose DAF, UF or RO first?
Start with the discharge objective. DAF is a potential solids and oil-and-grease pretreatment option where influent data supports flotation; UF followed by RO is the relevant sequence for confirmed blowdown reuse. For a reuse decision, request site-specific recovery, feed-quality limits, concentrate handling and a comparison of site-specific cooling blowdown treatment requirements against the Anyang-si basis of design.
Can sewer-compliant cooling blowdown be reused as cooling makeup?
No conclusion follows from sewer compliance alone. The owner must define the cooling-makeup target and assess scaling, corrosion, microbial control and monitoring separately from the sewer permit. A reuse trial or validated water-balance model should confirm whether the proposed pretreatment and UF-RO sequence can meet that target.
What data should be submitted to the relevant authorities, and how should suppliers be sized?
Submit measured average and peak flows, source-water and blowdown chemistry, temperature, chemical additions, cycles of concentration, the proposed discharge or reuse route, and monitoring and compliance arrangements. Require every bidder to use that same measured duty, chemistry, treated-water objective, recovery, redundancy and expansion basis; then compare guarantees, utilities, chemicals, sludge and life-cycle requirements. Obtain authority confirmation before releasing final equipment commitments.
