The first shot was fired last week by green groups, which warned both the Airport Authority and environmental officials that they are closely watching how an environmental impact assessment for the third runway is to be carried out.
The law governing such assessment requires the authority to produce a project profile, upon which the director of environmental protection will base a study brief for the assessment.
The project profile should lay out the key issues and impacts of the proposed runway.
The law gives the public only 14 days to comment on the project profile. For the runway profile, the deadline for feedback was June 11, but the green groups issued their detailed concerns a few days before that.
By doing so, the groups expected to spur officials to demand a better project profile. And this week, officials announced that they were requesting some additional information from the authority.
So, what is lacking, according to the green groups? On air quality, they said the profile was unclear about the pollutants to be measured. It omitted specific mention of harmful nitrogen dioxide, ozone, and coarse and fine particulate, which will be generated by the runway project.
Moreover, the emissions expected from the government's proposed waste incinerator had not been included in assessing Hong Kong's overall pollution.
People living in Tung Chung should be particularly concerned. In the first two months of this year, fine particulate levels were among the highest recorded at the government's 11 general monitoring stations.
Those levels even exceeded readings from two of the three roadside monitoring stations.
Furthermore, ozone concentrations in Tung Chung exceeded Hong Kong's very lax air quality objectives 39 times last year, the highest number of all 14 monitoring stations.
The third runway will undoubtedly exacerbate Tung Chung residents' health risks without proper mitigation measures.
Aircraft noise is of particular concern to residents of Ma Wan, Tuen Mun and Castle Peak. The project profile made no mention of measuring, projecting and monitoring the noise at these sites.
The green groups say that unless noise around these areas and other communities close to potential air paths are covered, the impact on public health and well-being cannot be adequately assessed.
On marine ecology, the profile omitted the most recent information on the declining population trends of the Chinese white dolphin, even though the law calls for the most updated information on impact on the natural environment. Equally surprising is the omission of the Chek Lap Kok marine exclusion zone from a list of vulnerable sites on which any impact should be assessed in detail.
Air quality and the runway project pose an early challenge to the new administration taking power on July 1.
Green groups have little trust in environmental officials, so they worry that the director of environmental protection will issue a study brief that gives the Airport Authority an easy ride.
The good news is a new project profile must now be put together. Vigilance pays.
Christine Loh Kung-wai is chief executive of the think tank Civic Exchange. email@example.com