Local food manufacturer Whye Kee Foodstuff was fined $17,700 for illegal discharge of trade effluent, or liquid waste created by businesses, into public sewers on multiple occasions.
National water agency PUB discovered the offences during site inspections of Whye Kee's premises in Tai Seng Avenue between September and October last year.
The liquid waste sample collected during one of the inspections was found to have exceeded allowable limits by more than 120 times.
Investigations showed the company, which manufactures rice products, had failed to put measures in place to prevent excessive food waste generated from its manufacturing processes from going into the sewers.
It was fined last month for the illegal discharge after having been fined $14,400 for similar offences in May last year.
PUB said yesterday in response to queries from The Straits Times: "Whye Kee could have put in strainers to remove the scum from the food manufacturing activities... or collected the food waste separately for disposal by general waste collectors."
The firm also did not pre-treat its waste to meet discharge limits.
PUB added that it has from May 4 this year revoked approval for Whye Kee to discharge its liquid waste into sewers, and the company has to engage waste collectors to collect its waste water for off-site disposal.
The agency said excessive levels of these substances in the sewage can upset water treatment processes at water reclamation plants and disrupt Newater production.
This is because high concentrations of these substances are toxic to micro-organisms which reclamation plants rely on to treat used water.
PUB said it took enforcement action against 30 companies last year for illegal discharge of liquid waste into public sewers.
Most of the offenders were manufacturing companies from the packaging, chemical and electronics sector.
Those who illegally discharge liquid waste containing chemical substances exceeding allowable limits can be fined between $5,000 and $15,000 for each offence.
Director of PUB's water reclamation network Maurice Neo said the agency will not hesitate to prosecute companies which disregard these regulations, and will step up the frequency of inspections at the premises of repeat offenders.