The Fire Services Department today said the white foam found in a water pond in Tseung Kwan O last night was firefighting foam that had inadvertently gone into the stormwater drainage system, and follow-up work is ongoing.

Responding to media enquiries, the FSD said it received a report last night about the discovery of white foam in a Siu Chik Sha water pond.

The FSD explained that it conducted a test of “biodegradable fluorine-free firefighting foam” yesterday at the Fire & Ambulance Services Academy (FASA) close to the pond's location.

The department suspects that some of the firefighting foam did not divert into the pipes of the foam treatment system during the test, and inadvertently went into the stormwater drainage system.

The FSD immediately cleaned the FASA stormwater drainage system and took on-site samples for further testing by the Government Laboratory.

It also arranged for a contractor to inspect the foam treatment system, which also completed the cleaning work at nearby channels late this afternoon.

The FSD said it will closely monitor the situation of the nearby channels in these few days and take appropriate follow-up action if any more foam is found.

Additionally, the FASA has suspended all drills involving firefighting foam until the cleaning work and inspection of the foam treatment system are completed.

The FSD will continue to co-operate with various departments on the matter.

It emphasised that the foam concentrate used in the test is a fluorine-free firefighting foam that is biodegradable and does not remain in the environment as a persistent organic pollutant.