SHENZHEN is redoubling its efforts to reduce air and river pollution in a bid to keep the title as a national green model city, which will be put to the test at an inspection by the national environmental watchdog next year.

The inspection by the State Environment Protection Administration (SEPA) was originally slated for 2004, but has been delayed after a request by the city to postpone it to the first half of next year, the city's environmental bureau announced Wednesday.

The city requested a postponement as it was not ready, the bureau said.

Shenzhen, which won the title of "Model City for Environmental Protection" in 1997, would lose the title if it did not pass the inspection.

SEPA inspects the title holders every few years to see if they remain eligible. Shenzhen passed an inspection in 1999.

The municipal environmental protection bureau requested the postponement of the inspection after realizing that SEPA had raised its inspection standards. In 1997 and 1999, SEPA inspected just the four districts within the special economic zone, but in its next inspection will cover all districts in Shenzhen.

SEPA also requires the city to treat at least 70 percent of its sewage, up from 45 percent in 1997.

Water pollution is the biggest environmental problem for Shenzhen, according to the bureau. The city has spent a total of 4.47 billion yuan (US$551 million) on water treatment in the past three years. The monitoring of major rivers in October showed that the water quality in Xinzhou, Dasha and Futian rivers has improved greatly.

Editor: Wing