The Qingpu district government has been taking measures for at least a year to improve a local garbage processing plant that remains the target of complaints from residents in neighboring Kunshan, Jiangsu Province, district officials said at a press conference Wednesday.

Kunshan residents have been complaining for years about a foul odor coming from the plant, which sits just across the river in Qingpu, according to a news report Sunday on China National Radio.

The smell has irked residents several kilometers away in two neighboring towns in Jiangsu Province, a county official told China National Radio. One resident said that the smell gets so bad at times that residents dare not open their windows.

A Qingpu district official acknowledged that there was an odor at the plant, but denied Wednesday that it could be the cause of so many complaints.

The foul odor must be coming from somewhere else, said Yu Xufeng, vice director of the Qingpu District People's Government.

The Qingpu District Domestic Waste Comprehensive Processing Plant, located at 4429 Qingzhao Road, opened in January 2010. The plant composts organic waste and processes it into fertilizer.

Yu did acknowledge problems at the plant, but emphasized that the district government has taken steps to solve them.

For example, the plant used to bury leftover waste from the processing at four landfills at the site, which was the cause of much of the odor emanating from the plant, said Chen Yu, director of the Qingpu District Afforestation and City Appearance and Environmental Sanitation Administration.

In November, the plant stopped burying leftover waste at the site, Chen said. It covered the landfills with 80 centimeters of soil and plans to plant trees there next March.

Last month, the plant reduced the amount of garbage it processed to 459 tons a day on average, Chen said. Last year, the plant was processing an average of 700 tons of garbage each day, exceeding its daily capacity of 500 tons.

Today, about 150 tons of leftover waste and 200 tons of garbage are transferred to the Laogang Waste Disposal Center in Pudong New Area.

Poor management at the plant, which is owned by Shanghai Guoqing Bio-technology Co Ltd, has also contributed to the problem, Yu said. Workers sometimes turned off machines that served to reduce the odor. Managers also used to ignore government orders.

In May, the company changed the plant's management team at the request of the district government.

The Qingpu District Environmental Protection Bureau has been monitoring the water, gas and residua released from the plant once a week since March, finding that the release generally meets environmental standards, said Zhao Honglin, the bureau's director.