The AA’s "triple water system" helps reduce the airport’s freshwater demand by over 50% each year.

Hong Kong International Airport (HKIA) is well equipped with large-scale water-saving facilities, and the airport implements a number of measures to minimise daily water usage.

Our Story

Total water management

HKIA adopts a "triple water system" to improve the efficiency of our three major water sources: freshwater, seawater and treated wastewater.

Seawater is used for flushing toilets, and is also used as the cooling medium in the air-conditioning systems of major airport buildings. Seawater is an infinitely renewable resource and it substantially reduces our use of potable water.

We recover wastewater from terminal building kitchens, washroom sinks, and aircraft catering and cleaning activities, then we treat it for use in landscape irrigation.

Since 2006 our wastewater treatment plant has treated over 10 million cubic metres of wastewater, meeting the irrigation needs of all of the landscaped area on the airport island. This "triple water system" helps us reduce our freshwater demand by over 50% each year.

Preventing marine pollution

Preventing marine pollution

HKIA’s measures to manage sewage and storm water discharges include:

  • Deploying extensive petrol / oil interceptors in areas where a pollution risk exists, including apron areas and carparks;
  • Installing spill traps at storm water outfalls; and
  • Discharging storm water away from the potentially sensitive southern sea channel.

The Airport Authority regularly monitors HKIA's impact on the marine environment caused by sewage and storm water discharges. Results indicate that cooling water and storm drain discharges from the airport do not have an adverse impact on local water quality.

Clean potable water

Clean, potable water

HKIA is committed to ensuring that all drinking water meets World Health Organisation standards, as well as local standards set by the Department of Health. To ensure compliance, we manage comprehensive, ongoing maintenance and cleaning efforts covering all drinking fountains in the terminals.

Quick Facts


The AA’s “Triple water system” has served HKIA since 1998.


Over 50% of freshwater demand has been reduced through the adoption of the “triple water system”.


Over 10,000 cubic meters of wastewater is treated by the AA each year.

25%-50% savings

Using seawater for flushing requires just 25-50% of the energy required if the same amount of freshwater were used.

HKD$19.5m savings

Savings related to the “triple water system” and the wastewater treatment plant, as a result of reduced purchase of potable water and a lower waste effluent surcharge, are approximately HKD$19.5 million.


Total volume of wastewater recycled / reused (m3) 178,867 204,475 364,000 242,043 160,254
Estimated volume of seawater used for flushing (m3) 3.0 million 3.5 million 7.5 million 7.1 million 6.3 million
Volume of seawater used for cooling (m3) 112 million 116 million 86 million 82 million 75 million