Preparation for a new residential precinct in Kallang kicked off yesterday with a tender to treat the soil on the site of a gasworks plant that once powered the entire nation.

The Singapore Land Authority (SLA) called for a tender yesterday to conduct remediation works on the former site of Kallang Gasworks, in the first such exercise of its kind. The plant was constructed in 1862 to manufacture gas using coal, and ceased operations in 1998.

On the Kallang site, the plant occupied 3.14ha, around the size of three football fields and almost 20 per cent of the made-over Kampong Bugis district. The precinct will be redeveloped into a car-lite waterfront district with about 4,000 new private homes and is expected to be ready in the next decade.

To achieve this, the SLA also acquired a parcel of private land from Singapore-Johore Express, a transport company that ventured into property, at market value yesterday.

The 914 sq m plot currently sites the company's showroom for its freehold Kallang Riverside condominium, which sits on the edge of the precinct, facing the Singapore River. The showroom must make way by April 30 next year.

In a joint statement, the SLA and Urban Redevelopment Authority said environmental site assessments found chemicals in the soil typical of those in land used for gas production.

The remediation, which will treat the soil using thermal methods and soil washing, will ensure that the quality of the soil will be suitable for its intended use, the agencies said.

Nanyang Technological University engineering expert Fang Ming-liang said that, left untreated, the chemicals can contaminate ground water.

The remediation works would require all the soil to be dug up and put in a reagent - "almost like a detergent"- so that the oil elements can be removed, Assistant Professor Fang said.

The site will be enclosed so that vapours do not seep out and rain does not wash the contaminated soil to the river, he added.

"People don't need to be worried because the remediation plans are quite comprehensive and meet international standards for health and safety," Prof Fang said.

Similar works have been successfully carried out at former gasworks elsewhere, including an upscale retail district in Brisbane, Australia, and a luxury mixed-use space in King's Cross, London.

Preliminary works should start in November and be completed by 2022. But the tender for a master developer for the entire precinct will be out only in a year or two, The Straits Times understands.

Kampong Bugis is one of three rejuvenated districts that the authorities unveiled last year. The other two are Holland Plain in Bukit Timah and Bayshore in East Coast.

The futuristic towns, with their emphasis on fewer cars and more open public spaces, will bring a total of 19,000 new homes.