Southeast Asia · Case study

Westports, Port Klang, Wastewater Treatment and Stormwater Drainage

Pulau Indah, Port Klang, Selangor, MalaysiaFY2024 to FY2025 reporting; drainage assessment published 2026

Westports Holdings Berhad operates container and conventional cargo terminals at Port Klang. In its FY2024 sustainability report, Westports said monthly laboratory analyses were performed at five sewage treatment plants and 25 discharge points, monitoring biochemical oxygen demand (BOD), total suspended solids (TSS), oil and grease, and nitrogen. The same report described annual water sampling at outlets to the sea and oil-and-grease traps at maintenance facilities. (Westports Holdings Berhad, 2025, p. 42.)

Westports’ FY2025 sustainability report states that effluent is channelled through oil interceptors and treatment systems to meet Department of Environment discharge requirements. Its performance data record 461,580 m³ of treated effluent in FY2025 and report effluent analyses for BOD, TSS, chemical oxygen demand (COD), oil and grease, ammoniacal nitrogen, nitrate and phosphorus. (Westports Holdings Berhad, 2026, pp. 25, 62-63.)

A 2026 climate physical-risk assessment describes the stormwater drainage network as combining surface and subsurface drainage, including French drains, slotted drains, sumps, reinforced-concrete pipe culverts and outfalls to the sea or harbour. It maps the network across container terminals CT1 to CT9 and reports culvert discharge capacity of up to approximately 3.10 m³/s. The assessment also identifies potential tidal backflow and submerged-outfall constraints, and recommends measures such as flap gates or duckbill valves. These are recommendations in the assessment; the report does not establish that they have been installed. (Westports Malaysia Sdn Bhd, 2026, pp. 68-69.)

Transferability

For other ports, the case illustrates the value of combining wastewater treatment and effluent monitoring with a mapped stormwater network and an explicit review of discharge capacity and tidal backflow risks.

The published evidence supports the monitoring and drainage-system descriptions above; it does not establish that every recommended adaptation measure has been implemented.

Sources

All information used for this case study was based on publicly available resources.