Conservation groups used to fight for environmental impact assessments or EIAs to be carried out before big government development projects.

Today, that fight has been partly won with government agencies commissioning such assessments to scope out the environmental impact of big projects, such as the 50km Cross Island Line that may tunnel under the Central Catchment Nature Reserve, and plans to develop five wildlife parks in Mandai.

But the larger battle to protect Singapore's remaining wild spaces continues, and one battlefront is over EIA conclusions, with the Nature Society (Singapore) (NSS) openly disputing the findings on the Mandai project and calling the conclusion of the EIA commissioned by Mandai Park Holdings "highly questionable".

What underpins EIAs is the principle of looking before you leap. EIAs are done before a new development is built and include detailed studies on how going ahead would affect the environment and surrounding areas, and suggestions for measures to mitigate these effects.

EIAs are a tool used around the world to inform decisions on how to modify development activity to reduce environmental impact.

If not properly used, though, EIAs can raise more questions than answers.

In the case of Singapore, which is fairly new to their use, three key issues need to be addressed: First, when is an EIA required? Second, does the process need to be standardised? Third, how transparent should developers be with the EIA results?

Checks and balances

Singapore lacks a law on EIAs which would, among other things, set out when such studies are mandatory.

It is also unique in that the development of each plot of land is usually done by the Government.

That is unlike other countries in South-east Asia where developments are usually done by the private sector or a public-private partnership, says ecology consultant Ong Say Lin, who works on projects in the region.

In the latter case, these projects - where funding may be from international banks - have the obligation to adhere to strict international standards that can serve as a "check and balance" on top of local government approval, he says.

In Singapore, there is no such check and the Government maintains that it is not necessary to enact stand-alone legislation for EIAs as the current planning evaluation process "has worked well".

"Under this process, all projects that could have potential impact on the environment are screened," said a spokesman from the Ministry of National Development(MND). "Projects that are likely to have significant environmental impact are subject to detailed EIA studies... (which) comprehensively assess the potential impact on areas such as biodiversity, hydrology, water quality, air and noise pollution, vibration, recreation, sediment transport, navigation and trans-boundary impacts, depending on the project's context."

Examples of projects that have been identified for detailed EIA studies include the Cross Island Line, the Tuas Port development and the Mandai project, the MND said. Yet, it remains unclear how the ministry goes about deciding when a project is likely to have significant environmental impact. The three examples cited differ from one another in that the first is inside a nature reserve, the second is at sea and the third is outside a nature reserve.

In comparison, Hong Kong's Environmental Impact Assessment Ordinance sets out when EIAs are mandatory, such as when a project covers more than 20ha or involves a population of more than 100,000 people. It also requires EIAs to be done for very specific projects, such as when a transport depot is to be built less than 200m from the nearest boundary of an existing or planned residential area or place of worship; or if reclamation work of more than 1ha in size is to be done less than 500m from an existing or planned conservation area.

Standards needed

Without an EIA law, the consultant is also free to interpret the scope of such an assessment. Currently, studies here tend to be done so as to meet the requirements in the tender, says Ms Natalia Huang, principal ecologist at environmental consultancy firm Ecology Matters.

She worries that different interpretations can result in one consultant proposing a one-day walk through the site, with another suggesting intensive surveys for every animal and plant group over several months.

"Without local standards to meet, consultants with the lower quote may be chosen, whether or not their studies are appropriate to understand the environment sufficiently for an EIA," says Ms Huang.

Then there is also the issue of a lack of clarity in the terms used by EIA consultants. The high-profile cases of the Mandai and Cross Island Line projects underscore this. On the Mandai project, the NSS said in a position paper in September that some of the impact assessments in the EIA had been underplayed. An example was the EIA's assessment of the magnitude of the environmental impact of clearing 28.5ha of natural habitat in Mandai.

The EIA on Mandai was carried out by the consultancy Environmental Resources Management, which also did the Cross Island Line EIA. It determined that in the case of Mandai, the impact could be reduced from "medium" to "small" if mitigation measures, such as forest restoration and avoiding work in certain areas, were enforced.

But the NSS said the report did not provide information on what percentage of the existing habitat this amounted to, and questioned how the impact magnitude was obtained, considering the project site's strategic location just outside the nature reserve.

It recalls a time earlier this year when the Land Transport Authority (LTA) revealed the results of the first phase of the EIA for the Cross Island Line, which had looked at the impact of tests to determine the soil and rock profile under the reserve. EIA had put the impact of soil works as "moderate" if mitigating measures were strictly enforced. But members of the public were left scratching their heads as to what "moderate" meant.

It prompted Non-Constituency MP Leon Perera to ask in Parliament how the consultants arrived at the conclusion. In response, Senior Minister of State for National Development Desmond Lee produced a matrix showing that the nature reserve, comprising primary rainforests, was a "highly sensitive" habitat but that the magnitude of impact of the investigation works would be "small" as the Government would put in place mitigating measures. The final impact was thus judged "moderate".

Some ecologists, however, found the assessment highly subjective. They would like to see some standards established, with Ms Huang, for one, suggesting that the assessor be an experienced biologist familiar with the local environment, and that the terms be based on scientific evidence and expert judgement. In that way, they would be "reasonably robust", she says.

Public access to findings

Hong Kong and Australia require developers to be transparent with the EIA results. Singapore government agencies are, however, not bound by any such requirement.

Associate Professor Lye Lin-Heng, director of the National University of Singapore's (NUS) Asia-Pacific Centre for Environmental Law, says transparency is important "as the Government is not the sole repository of information about the habitats". Dialogue with scientists, nature groups and members of the public would help the authorities make more informed decisions about whether to proceed with a development and how to do so, she adds.

Both Mandai Park Holdings and the LTA have made their EIAs available online but the LTA did so only after members of the public complained about limited access to the 1,000-page document. The LTA first gazetted the report on Feb 5, but people could look at the report only after the Chinese New Year break on Feb 10, and then only by appointment at the LTA's Hampshire Road premises.

Developer Mandai Park Holdings did better in this aspect. It consulted nature groups and government agencies on the approach, methodology and results of the EIA several times and this consultation process was initiated in 2012, well before the EIA process began in late 2014.

Mandai Park Holdings also engaged an environmental advisory panel to provide counsel and oversight on the implementation of mitigation measures set out in the EIA.

Given that Singapore is fairly new to the EIA process, it should be no surprise that there is room for improvement.

In considering how best to move forward, it is useful to return to the intent of EIAs, which is to assess potential harm and take steps to minimise irreversible damage.

To realise that, the EIA process here needs to be made more robust.

Dr Nanthinee Jevanandam, a sustainability specialist from Earthys Sustainability Consulting, sums it up well.

She says: "It is better to avoid a problem than to create it, then try and find a fix which may or may not be effective. If you consider this question on a global level, climate change would not have been an issue if we had considered environmental impact in becoming more industrialised."