Developers of projects near sensitive areas such as nature reserves and others with significant biodiversity, marine or coastal stretches, or those with potential transboundary impact, are subjected to greater scrutiny, National Development Minister Desmond Lee told Parliament yesterday.

These developers are required to engage in an in-depth consultation process with multiple public agencies to review the project's potential impact not only on the environment, but also on traffic, public health and heritage.

Depending on the scope of the project and the potential impact on the environment, detailed studies may be required. These can include an environmental baseline study or a more detailed environmental impact study, which sets out the environmental baseline, expected impact and mitigation measures.

"The studies enable agencies to better assess the possible environmental impact of the development plans and the adequacy of the proposed mitigation measures, to guide the planning and potential development of the site," said Mr Lee.

He gave an overview of the different roles played by various agencies in this process, in his response to parliamentary questions filed by 15 MPs from both sides of the House on the erroneous clearing of a patch of woodland in Kranji, and related issues.

The National Environment Agency assesses the potential for noise, water or air pollution.

The Maritime and Port Authority of Singapore assesses impact on navigation, while the Singapore Food Agency is in charge of sea-based farms.

The National Parks Board (NParks) handles the assessment of impact on terrestrial and marine biodiversity.

Giving the example of a site clearance project involving the felling of trees, Mr Lee said NParks would require a tree survey to assess the potential impact of the plan.

"If NParks assesses that conducting a further environmental baseline or other forms of study is not required, it may allow some types of work to begin. However, NParks may require mitigation measures, such as the installation of hoarding or an environmental monitoring and management programme to be in place," said Mr Lee.

"For past incidents of tree felling without prior approval, NParks had conducted investigations and issued penalties. The environmental impact of such incidents varies depending on the site context and the extent of works undertaken."

The minister said planning permission for a project to go ahead is granted only after it has met the requirements imposed by the various regulatory agencies.

These include completing detailed technical studies, such as environmental and traffic impact assessments, as well as putting in place mitigation measures.

Mr Lee also said his ministry is studying whether it would be better to centralise the management of environmental impact assessment consultants instead of having individual developers or agencies manage their own.

Several MPs had supplementary questions for Mr Lee.

Mr Alex Yam (Marsiling-Yew Tee GRC) asked how many instances of unauthorised tree clearance had happened last year, to which Mr Lee responded that there were no incidents where NParks had to take action. He added that the last such case NParks pursued was in 2019.

Mr Dennis Tan (Hougang) and Mr Louis Ng (Nee Soon GRC) both raised the question of whether an environmental assessment framework should be codified in law.

Mr Lee said there are already laws that augment the framework in place and are among the tools that the Government uses to ensure the framework is holistic, rigorous and comprehensive.

He cited how the Planning Act empowers the Urban Redevelopment Authority to act as a gatekeeper and screen development plans before they are implemented.

Under the Parks and Trees Act and the recently passed Wildlife Act, there is legislative power for agencies to impose the requisite studies, measures and penalties. There are also laws governing the pollution of water bodies, Mr Lee said.