It is heartening to know that the National Parks Board granted approval for soil investigation works to take place in the Central Catchment Nature Reserve (CCNR) only after extensive public consultations and discussions on mitigation measures ("Additional mitigation measures for train works after discussions with nature groups: LTA", ST Online, June 8; and "10 new measures to keep forest safe during train tunnel tests", June 9).

However, there remains many questions. How was the public involved and who had a say in the decision-making process? What standards were the decision based on?

One of the most important objectives of an environmental impact assessment (EIA) is to facilitate informed decision-making.

In the case of Phase 1 of the EIA, the EIA should not be conducted with the end goal of mitigating effects of soil investigation works.

Rather, it should guide the decision-making process on whether soil investigation works should even occur in the CCNR.

However, discussions appear largely centred on measures to minimise the impact of works in the CCNR. Was there due consideration given to the possibility of not conducting works?

Today, soil investigation works, deemed by Phase 1 of the EIA to have a "moderate" impact on the CCNR, will be allowed to take place.

We can only expect Phase 2, assessing the impact of construction and operations, to show similar, if not greater, impact.

Where do we draw the line? What level of impact on our nature spaces will we consider acceptable?

The debate on this issue is not just about developments on the Cross Island Line and the CCNR. It is also about our values and baselines regarding the protection of our natural spaces and future development needs.

We should not be satisfied with a one-time victory for development or conservation.

It is imperative to take lessons from this experience to improve the EIA process. This will go a long way in Singapore's road towards balancing both development and conservation needs.

Angela Chan An Qi (Miss)