Zhao Feng collecting swill from a restaurant in Suzhou. Zhao and his father Zhao Jinghua can earn a combined 10,000 yuan a month by collecting gutter oil and waste from 100 restaurants in the city every day. All the waste oil they collect is transported to Jiangsu Clean to be processed into biodiesel. Xie Yu / China Daily

A lack of raw materials

Despite its legal status, Jiangsu Clean is finding it difficult to gain access to the raw materials. Song told China Daily that his company reclaims "50 percent" of the gutter oil produced in the city every day.

However, according to Lu Fengchao, who drives an oil tanker for Jiangsu Clean in Suzhou, the company can only reclaim 20 percent of the city's daily output of gutter oil. "The rest is seized by illegal collectors. They've got a network. Almost every day, we have confrontations with them, you know, to fight for the gutter oil. But they can gather a group of thugs with one phone call and we have no choice but leave the oil to them," he said.

Moreover, even though Jiangsu Clean is the only collector approved by the Suzhou government, some restaurant owners simply ignore the regulations. "The owners, especially the canteen managers in big factories and companies, mostly State-owned, simply refuse to provide us with the used oil because we don't have to pay them. Instead, they sell it to illegal collectors for about 4,000 yuan a ton," Lu said.

New strategy

In a bid to prevent restaurants from selling waste oil to illegal collectors, the authorities in Shanghai have drawn up a new strategy allowing oil-processing companies to collect the raw materials directly.

"Under the plan, the number of intermediate links are reduced, thus cutting out some of the collectors who sell the waste oil to illegal companies," said Gu Zhenhua, deputy director of the Shanghai Food Safety Office.

The plan is part of the city's latest move to crack down on the recycling of gutter oil and prevent it from returning to the city's dining tables. "The oil processing companies are responsible for the whole chain of collecting, transporting and processing the waste oil," said Gu.

Under the new regulation, all restaurants in the city are required to install machinery designed to prevent the waste oil from entering the city sewers. This equipment eradicates the possibility of underground gangs collecting the oil at source by separating the oil and grease from the waste water before it enters the sewerage system. The installation of the new machinery is scheduled to be completed by the end of 2012.

However, while the cities are cleaning up their acts, Zhao Feng plans to carry on working as long as he can. For him, gutter oil means survival: "It's smelly work and it's tiring, but it makes me a lot of money and does a lot of good for the city".

Write to reporters at [email protected] and [email protected]