As a shelter for rescued wildlife, it was meant to be clean, safe and ecologically sound.
Instead, part of the site ended up as a stinking, contaminated wasteland after a contractor filled the soil with woodchips that rotted.
Now, animal welfare group Acres - which first took legal action in 2008 - has been awarded $26.5 million in damages.
"After five long years, there has been some closure finally," its director Louis Ng told The Straits Times yesterday. "Justice has been served, and we hope to get final closure by pursuing payments from the defendants."
Acres - known in full as the Animal Concerns Research and Education Society - hired ANA Contractors to level a site the size of two football fields back in 2006.
It then built the $650,000 shelter to house creatures such as turtles, snakes and monkeys that were rescued from the illegal wildlife trade.
But 1.5ha of the Choa Chu Kang sanctuary had to be demolished after the contractor filled the earth with material believed to contain toxic hydrocarbon and other chemicals.
Foul-smelling brackish water leaked from the soil, and the National Environment Agency declared it a pollution threat to the nearby Kranji Reservoir.
Hiring a licensed toxic waste collector to clean it up will cost about $23 million, according to court documents.
And to stop the discharge from entering the reservoir, Acres had to install a special tank.
So far, this has set the group back by about $62,000.
In 2011, a court found ANA Contractors and site supervisor and director Tan Boon Kwee liable for the damage. Mr Tan was made a bankrupt last July, dragging out the court proceedings.
High Court assistant registrar James Lee has now set the sum of damages at $26.5 million.
It is believed to be the first case where a civic action group has successfully sued for environmental damage that is linked to the high degree of care needed to dispose of contaminated earth. Each tonne of soil that had to be removed cost between $400 and $600, court documents showed.
Other claims included the amount of wasted rent paid to the Singapore Land Authority for the use of the contaminated land.
Acres has sheltered about 2,700 animals at the site since September 2009, Mr Ng told The Straits Times yesterday.
After being rescued and kept in the sanctuary, the animals are released in Singapore or abroad.
Lawyers Muralli Rajaram and Suresh Nair, who are representing Acres, said that whatever legal costs they recover from the other party will be donated to the animal welfare group.