How does Singapore keep its toxic industrial waste from entering its waterways?

SINGAPORE: As Singapore’s toxic industrial waste volume grows, the need to treat it properly before it is released into the nation’s waterways has come under the spotlight.
Singapore typically generates about 500,000 tonnes of hazardous waste every year.
However, this has been increasing by about 10 per cent year on year for more than two decades, according to one firm that handles hazardous by-products from various industries such as oil and gas, pharmaceuticals, and electronics.
Waste management company Environmental Solutions Group Holdings processes about 100 types of toxic industrial waste – including mercury, hydrochloric and sulphuric acids – and even poisons like cyanides, said the firm’s executive director Lawrence Law. 
The waste is first analysed in a laboratory, then heavily treated so it is safe enough to be released into the nation’s sewers. It will then be purified to produce reclaimed water, also known as NEWater.
The consequences of discharging untreated industrial waste indiscriminately can have several undesirable effects, said Mr Law. 
Citing the example of black sulphuric acid, which is released by petrochemical plants, he said: “It will pollute our waterways and it will start to kill our aquatic plants (and animals).” 
He added that carcinogens in these substances would also be harmful to people, and that the public sewer system is not designed to convey hazardous waste, which may corrode pipes in the system.
The importance of treating toxic industrial waste came under the spotlight on Monday (Nov 11) in parliament, where higher penalties for the illegal discharge of harmful waste into sewers were passed into law.
For instance, a company that discharges hazardous substances without national water agency PUB’s approval, causing injury to workers and damage to sewers, will face a new minimum fine of S$40,000 (US$29,900).
The maximum penalty will also be doubled to S$400,000.
Between 2017 and 2023, PUB prosecuted 90 offenders for 295 effluent-related offences, said Senior Minister of State for Sustainability and the Environment Amy Khor. About 70 per cent of those prosecuted each year were repeat offenders, she added. 
To prevent themselves from falling afoul of the law, many firms have turned to waste management solutions like the ones Mr Law’s firm provides. 
Building their own treatment facilities can be relatively expensive without economies of scale, and it can also be tough to keep up with the regulatory needs, said Mr Law.
“In order for you to treat waste, you need additional licences so it means additional effort as well,” he noted.
However, one company that has opted to build its own treatment facility is semiconductor manufacturing firm Applied Materials. 
The water it uses for testing in its manufacturing process cannot be directly discharged into public sewers as it does not meet PUB’s pH level standards, said facilities manager Karl Ian Tuazon.
Having an onsite treatment plant also allows the firm to use treated water for the building’s cooling system, he added.
To keep Singapore’s waterways safe, PUB has also increased its frequency of inspections at construction sites to ensure measures have been deployed to prevent silty discharge ahead of the north-east monsoon season from December to March.
Such discharge is a result of rainwater mixing with exposed earth and soil at construction sites.
 
If silt accumulates in drains, it can obstruct rainwater drainage, leading to flash floods.
Maximum penalties for repeat offenders who carry out works that could cause silt to be discharged into drains and canals have also been doubled, to S$100,000.
One contractor that has put in effort to ensure such incidents do not take place is China Communications Construction Company-Sinohydro Joint Venture.
The firm, which treats its silty water before discharging it into public drains, has put in place extra safeguards, like a holding pond that filters soil sediments. 
It has also implemented an automated system that will automatically shut down the system to prevent the discharge of silty water from the work site.