The Tamar project is generating a lot of heated debate these days. But will it generate air pollution during its construction and operation? Some critics have suggested so, but I believe their fears are based on misconceptions and unfounded allegations.
The Tamar project mainly involves the creation of a two-hectare open space and the construction of a Central Government Complex and a Legislative Council Complex.
It was not subject to an Environmental Impact Assessment (EIA) because it is not a designated project under the EIA Ordinance. The ordinance requires projects such as 20 hectares in area or involving a population of more than 100,000 to conduct EIAs. Tamar will cover just 4.2 hectares, and its offices will accommodate about 3,600 people (including civil servants and LegCo secretariat staff).
Although an EIA was not carried out for the Tamar project, there was an EIA conducted for the Central Reclamation Phase III (CRIII), which includes the Tamar site. The EIA report went through the statutory public consultation under the EIA Ordinance and has been posted on the EIA Ordinance website since 2001.
It concluded that "the air quality at all existing and future air sensitive receivers subject to vehicular emissions will comply with the Air Quality Objectives". "Air sensitive receivers" are buildings or uses, including the Tamar project, that are susceptible to air pollution.
Assessment reliable
Some critics of Tamar have questioned the EIA's air quality assessment. Contrary to what they suggested, the assessment was conducted in accordance with established practice both internationally and in Hong Kong. It used CALINE4 (California Line Source Dispersion Model Version 4), a reliable and proven assessment model that has been widely applied overseas to model the air quality of densely built urban areas.
The assessment took into account the effects on the predicted air quality of existing, committed and planned developments in CRIII. It adopted a prudent, conservative approach, making use of the best available information and data.
Inputs to the air quality model included the cumulative impact of vehicle emissions from existing and proposed road networks within the assessment area; peak-hour traffic flows projected to 2027; conservative vehicle emission estimates; and worst-case weather conditions.
Some concern groups have argued that the EIA underestimated future levels of nitrogen dioxide and respirable suspended particulates. Their argument is based on the fact that the future estimates, up to 2027, are lower than the historical data recorded by roadside air monitoring stations.
In fact, thanks to measures implemented in recent years, roadside air quality in Hong Kong has been improving. Between 1999 and 2005, levels of roadside respirable suspended particulates were reduced by 14% and nitrogen [di]oxide by 17%. During the same period, the number of smoky vehicles was cut dramatically, by about 80 per cent.
Canyon effect
The Advisory Council on the Environment responsible for advising the Government on how to combat pollution and protect the environment studied the issue this past April, and concluded that there were insufficient grounds to revisit the EIA report on CRIII.
The council also concluded that there was not sufficient justification to suggest that the project would create a "street canyon effect", a phenomenon in which vehicle emissions are trapped between uninterrupted walls of tall buildings on both sides of a street.
Concerns about the "street canyon effect" were primarily based on a two-dimensional model that assumed no space between buildings. The Tamar development, on the other hand, will feature 2 hectares of open space as well as large gaps between buildings of different heights. Air will be able to circulate freely, negating any possible "canyon effect".
The impact of additional traffic on air quality at Tamar would also be insignificant. We expect the Tamar development to attract no more than 581 additional "passenger car units" during the morning peak and 406 passenger car units during the afternoon peak. In traffic analysis, a passenger car or taxi is equivalent to one passenger car unit; a bus or lorry equals two. These figures also include mini-buses and delivery vehicles.
On some unfounded allegations that Tamar ground soil might contain highly concentrated dioxins, any expert in the field could tell that only incineration of waste containing certain types of plastics (e.g. polyvinyl chloride) or similar materials with incomplete combustion would lead to chances of producing large amount of dioxins. There is no reason to believe that such incineration has ever taken place at the Tamar site, which is at the city centre of Central.
Environmental impact considered
Some people have muddled up the Tamar site with the circumstances pertaining to the former Cheoy Lee Shipyard. The normal operation of dockyards does not involve mass burning of certain types of plastic materials. The case of former Cheoy Lee Shipyard was exceptional in that dioxin-contaminated soil was found from some incineration pits and waste pits at the shipyard, and the contamination was related to activities involving mass combustion of certain types of plastic materials
The environmental impact of the Tamar project has been thoroughly considered and studied. The impact would be insignificant. And what little impact exists can be properly dealt with by standard pollution-control measures used these days in all major developments.
The Government is strongly committed to tackling the air pollution problem in Hong Kong. We will continue to implement vigorous measures on all fronts. Reducing local emissions, such as those from vehicles and power plants, will remain our priority.
On the review of the Air Quality Objectives, we have been in close liaison with international experts and organisations on the development of air quality standards objectives. We will take into account the review findings in the United States, European Union and World Health Organisation, as well as local studies, when considering the need for introducing new standards.
This was Acting Director of Environmental Protection Dr Michael Chiu's article published in a local newspaper on June 12.
