International Dredging Review

International Dredging Review

The Hong Kong International Airport’s “Invitation to Tender Three Runway System (3RS) Project” has closed. Known as Contract 3206 – Main Reclamation Works the tenders for this contract were due for submission to the Airport Authority not later than 16:30 (Hong Kong time) on Wednesday August 24. 

The Airport Authority Hong Kong has been considering the expansion of its two runway system at Hong Kong International Airport since 2010. In June 2011 after three years of studies conducted by multiple consulting groups the Airport Authority released the Hong Kong International Airport Master Plan 2030 a 20-year blueprint for the airport’s development. The main focus of the report was to improve the overall capacity and aircraft handling ability of the airport. After considering different alternatives the choice was made for a three-runway system referred to by the authorities in short-hand as 3RS. 3RS entails creating a new land reclamation upon which a third runway will be constructed. This runway will be situated on the northern side of Chek Lap Kok the existing island upon which Hong Kong International Airport is built.  


The 3RS is the single largest development planned for the airport since its opening almost 20 years ago and the scale of the work is quite similar to the original airport project. The project requires reclamation of approximately 650 hectares (more than 1600 acres) of land on the north side of the airport. The contract includes the construction of the main reclamation works bounded by approximately 13.4 kilometers (8.4 miles) of seawalls to be built around them ground improvement works supplying fill mate-rials laying sand blankets marine filling land-based filling surcharge and associated infrastructure and environmental protection works. 

Some of the key construction activities associated with the land formation works are:

• modification of the existing seawall for which the existing rock armour from the seawall will be removed and retained as far as practicable for reuse in the construction of the new seawall;

• ground improvement including the deep cement mixing (DCM) method within the extensive contaminated mud pit areas as well as DCM and other methods such as stone columns steel cells sand compaction piles vertical sand drains and prefabricated vertical drains for areas outside of the contaminated mud pit areas; 

• laying a sand blanket on the seabed to contain and minimize the release of marine sediment during these activities prior to the start of ground improvement activities;

• seawall construction in which the majority of the seawalls will be rock sloping seawalls with the exception of some localized areas (such as at the sea rescue landing points and marine loading points) where vertical seawalls are required; beyond the toe of the seawall scour (stone) aprons will be laid to protect the seawall toe against erosion; 


Diagram showing the 650 hectares (1600 acres) of the proposed reclamation area on the northern side of the present airport.

• filling works that require supplying a variety of fill materials including rock fill public fill sand fill rock armor and graded filter layer which will be used to form the land and seawalls; seawalls will be made of rock fill as the seawall core except where steel cells are used and rock armor and graded filter layer to form the protective layers and sand fill or a mix of sand fill and public fill will provide the marine filling mate-rial while a combination of sand fill and public fill will be used for land filling activities;

• placement of a temporary surcharge (an additional load to speed up consolidation of the new land) which will primarily be made of marine sand or public fill; during each stage of land formation the surcharge removed from a completed works area will be reused as far as practicable as fill material or surcharge in other active works areas.

The reclamation is estimated to need 100 million cubic meters (130 million cubic yards) of sand fill about five million cubic meters (6.5 million cubic yards) of rock fill and rock armor for the seawall and some 28 million cubic meters (36.5 million cubic yards) of public fill. Marine sand will be sourced from nearby quarries in the southern part of Mainland China. 

The challenges especially environmental challenges are quite extensive and quite different from the original airport land reclamation. The Environmental Impact Assessment (EIA) Report and the Environmental Monitoring and Audit (EM&A) have been extensive resulting in a number of clear-cut environmental measures. 

One difference with the original airport land reclamation is the result of the growth in ship-ping traffic and industry. Another is the presence of contaminated mud pits in the reclamation footprint area of Hong Kong’s waters. The mud is soft and cannot be removed and must be stabilized. The solution has been found in implementing extensive ground improvement techniques. These include a non-dredging method known as deep cement mixing (DCM) that immobilizes the contaminated sediment. This contamination also means that the sand must come from elsewhere in China outside of Hong Kong’s own waters. 

According to the Environmental Protection Department Hong Kong SAR Government since the 1990s many marine parks have been built and require protection and environmental awareness is far greater than twenty years ago. Consequently environmental measures are greatly improved. Among those to be implemented are the deployment of silt curtains a coral translocation plan a marine mammal watching plan and dolphin exclusion zone as a precautionary measures for the protection of the Chinese White Dolphin as well as an egretry survey of the nesting sites of egrets and herons and their seasonal breeding patterns. 

In addition the approved EIA Report recommended a proposal to establish a new marine park which would include an area of approximately 2400 hectares (more than 5900 acres) as compensation for the loss of seabed habitat and open waters habitat associated with the land formation for the 3RS project. Other environmental aspects include enhancement of habitats for marine ecology and fishery re-sources; the promotion of a sustainable fisheries industry; encouragement of scientific research and studies; and the promotion of environmental education and eco-tourism.

An effective Emergency Preparedness and Response Plan to spillage incidents during the 3RS project construction phase for implementation by all contractors is also required. These plans must include spill prevention measures spill response training and spill response equipment and emergency teams. Further details of the procurement method for the environmental protection works for monitoring including equipment and observing specialists are all stipulated in the contract award criteria in the tender documents and in the permitting documents issued by the government. The procurement of the project is covered by the Agreement on Government Procurement of the World Trade Organization.

The present airport with two runways and two terminals was opened in 1998 after a massive land reclamation project which involved almost all of the major dredging companies in the world. At the time the removal of mud and its disposal plus the transportation of mountains of sand brought in from borrow areas required the deployment of half the world’s trailing suction hopper dredges to Hong Kong. 

Dredging companies from Europe Japan and elsewhere sent their largest most modern equipment to dredge and reclaim sand from the adjoining seas to build the airport platform. In record time they united the island of Chek Lap Kok with the smaller Lam Chau. The islands were leveled and merged by creating a land reclamation using clean sand brought from distant borrow areas to be used as fill. The result was a 12.48 square kilometer (4.82 square mile) area upon which the current Hong Kong International Airport was constructed. 

Chek Lap Kok nicknamed the “airport in the water” as it is located in the Pearl River estuary part of the South China Sea is far from the mountains and increasingly large sky-scrapers that obstructed old Kai Tak Airport which was famously or infamously located in the center of Hong Kong. The new airport is an impressive and efficient example of modern airport technology. As an economic driver the airport has proven its worth to Hong Kong and the region. Recent statistics show that in 2014 some 63 million passengers and 4.5 million tons of cargo passed through the airport. But after 20 years growing the economy depends on also growing the airport. 

After the 3RS reclamation and preparation of the area associated facilities the runway and taxiway connection to the terminals airfield and apron facilities will be built in phases. The eight-year construction of 3RS is expected to be completed in 2024 with the commissioning of the new runway in 2022. Upon full-fledged commissioning the Third Runway System will be able to handle an additional 30 million passengers annually providing Hong Kong Inter-national Airport with the capacity to handle around 100 million passengers and nine million tons of cargo annually by 2030.