A group of swimmers, braving chilly conditions, jumped into the Donghe River in Rui'an, Zhejiang province, on Monday.

Their reason for making a splash? Not to show their athleticism but rather to make an environmental point.

The 50 or so swimmers own and run rubber-shoe factories in Xianjiang township that have been blamed in the past for polluting the environment.

Yang Yuguang, chairman of Zhejiang Anbang Shoes, said the quality of the river is better than he had imagined.

"The water is clear and is much better than before," he said. "We swam for more than 600 meters, and it felt good."

The 42-year-old said he thought it had been more than 20 years since people swam in the river.

"Everyone blamed our factories for causing the pollution. I cannot deny that in the past decade we harmed the environment. However, I also would like people to witness the changes we have made," he said.

Rui'an has the biggest cluster of rubber-shoe-making factories in the country with more than 1,000 factories accounting for almost 60 percent of the domestic market share.

Ye Mingzhe, general manager of Rui'an Fuyimei Shoe Industry Co, said there was a time when nobody cared about environmental protection.

"Five years ago, the river was a total mess, with blackish water. It was smelly, with all types of rubbish floating on it," Ye said.

The problem was not taken seriously until an entrepreneur posted a notice in social media.

Last February, Jin Zengmin, chairman of Hangzhou's Maoyuanchang Eyeglass Co, offered 200,000 yuan ($32,000) to any local environmental protection official in Rui'an willing to swim in a filthy local river for more than 20 minutes.

Jin's post aroused national attention. "Inviting environmental-protection officials to swim in local rivers" became a popular catchphrase for Chinese people.

Last year alone, the township spent more than 20 million yuan on environmental protection, most of the money coming from local entrepreneurs.

Ye said as local residents they had an obligation to make their hometown a better place.

"In the past, we lacked awareness and a thorough governmental plan. Now we have both."

Ye's company contributed more than 200,000 yuan last year to helping the local government clean rivers.

Chen Xue, deputy Party chief of the township, told Wenzhou Daily that 18 rivers have been cleaned in the last year or so.

"The quality of the water is tested once a quarter, and the standards will be maintained," Chen was quoted as saying.

Xia Baolong, Party chief of the province, said during a provincial economic meeting on Dec 27 that one of the key missions of the province in the coming years is to eliminate water pollution.

The province will spend 68 billion yuan in managing polluted waterways, starting from this year, Xia said.

yanyiqi@chinadaily.com.cn