Two companies that slashed their water bills by being efficient, a school whose students teach their peers to test water quality, and a teacher dedicated to environment education have won PUB's latest Watermark Awards.

Water agency PUB is giving out these awards for the seventh year to role models who conserve, protect and educate others about water.

This year's winners were semiconductor manufacturer Systems on Silicon Manufacturing Company, LED maker Philips Lumileds, Compassvale Secondary School in Sengkang, and mathematics teacher Ms Lim Bin, 35, of Woodgrove Secondary School in Woodlands, who advises the school's green club.

They will receive their awards at a ceremony on Sept 24. In the past, the award has gone to schools, companies, and organisations like the SCORE laundry service at Changi Prison and the Singapore Civil Defence Force for their water conservation efforts.