Air quality readings at a proposed reclamation site in Tuen Mun indicate it is "not that bad" for housing despite being surrounded by polluting industries, the government says.
Preliminary data from a monitoring station set up by CLP Power - operator of two nearby power stations - indicates the air at Lung Kwu Tan meets both present and future quality targets, the Civil Engineering and Development Department said.
"The existing air quality is not that bad as it meets the government's objectives," department director Hon Chi-keung said.
The department cited the data as it sought public support for reclamation to provide more land.
Lung Kwu Tan is among five potential sites listed by the government last month and one of two said to be suitable for residential use. The other one is Ma Liu Shui in Sha Tin.
But the suitability of Lung Kwu Tan has been questioned by the public and green groups as it is close to more than 10 of the city's most polluting facilities, including a landfill, power stations, aviation fuel storage and a cement plant.
Civil Engineering Office deputy head Robin Lee Kui-biu said data from CLP Power indicated that the air "does not only meet the existing objectives but also the future ones".
According to the 2011 findings, the annual mean concentration of nitrogen dioxide was 30 micrograms a cubic metre, well below the 80 micrograms specified in the existing objectives and 40 micrograms for the more stringent objective due to take effect next year.
Lee said sulphur dioxide concentration also met the two objectives but did not give figures.
"They are only the preliminary baseline data," he said.
"The actual quality will have to be examined when specific projects are decided for the reclaimed site."
Lee said the readings were collected from a monitoring station set up by the power company.
But the station is about three kilometres away from the natural gas power plant at Black Point and it is also some distance from the coal power plant at Castle Peak to the south.
The government plans to add eco-friendly features such as mangroves and an artificial reef to the future man-made coastline and seabed.
Hon said it would also like to seek green groups' views on ways to assess the impact on Chinese white dolphins, frequently seen in Lung Kwu Tan waters.
Friends of the Earth director for general affairs Edwin Lau Che-feng said meeting the new air quality objectives did not mean a healthy life for future residents as they were the lowest benchmark set by the World Health Organisation.
He urged the government to also look at the cumulative impact on the reclaimed area generated by various "not-in-my-backyard" facilities.
Dolphin Conservation Society chairman Samuel Hung Ka-yiu said Lung Kwu Tan and Siu Ho Wan on Lantau Island - another of the proposed reclamation sites - should be no-go areas for reclamation as they were important habitats for the dolphins.
He also said there had been a drastic fall in the number of dolphins sighted in Hong Kong waters because of public works including the Hong KongZhuhai-Macau Bridge.
He said the number had been halved from 158 in 2003 to 78 in 2011 and "the figure is expected to drop further".
The other proposed reclamation sites are Sunny Bay on Lantau and southwest Tsing Yi.