Tackling pollution at one of China's most famous lakes
Environmental scientist Kong Hainan walks by Erhai Lake in Dali, Yunnan Province.
Kong (second from right) and other researchers
Shanghai office worker Lindsay Ling was among 1.7 million visitors to the southwestern prefecture of Dali in Yunnan Province during the recent National Day golden week holiday.
Like many, she vacationed by famous Erhai Lake, which she described as a romantic escape from the hustle and bustle of urban life.
“I wish I could live by the crystal-clear waters for months,” she said. “It reminded me of somewhere else, like Santorini in Greece.”
Yet like many who found Erhai an ideal escape, she didn’t know its dirty little secret. The lake water is not nearly as clean as it was decades ago.
Dense blue-green algae started to plague the lake in the 1990s. The once pristine water became unsafe to drink and even poisonous to livestock. A pungent odor lingered in the air, giving local people headaches and dizziness.
To the rescue came environmental scientist Kong Hainan from the School of Environmental Science and Engineering at Shanghai Jiao Tong University.
After visiting Erhai Lake about 15 years ago, Kong decided to lend his expertise to returning the lake to its former glory.
“The water there was once super clear that I could see the bottom about 15 meters down,” Kong said. “Submerged plants stretched to the surface. The flourishing underwater forest extended more than 10 kilometers.”
The 70-year-old professor has been spending most of his time the past 15 years living by the lake. He has walked extensively over the area, which sits at an altitude of nearly 2,000 meters.
For a man suffering atrial fibrillation and hypertension, his undertaking was a bit risky. As the lake began to get some of its sparkle back, Kong was losing his grip on his own health.
He fainted twice during work, and his heart became weaker. He started to experience frequent relapses, from several times a year to once a week. Finally, he suspended work in September 2012. After flying back to Shanghai, he underwent two major heart surgeries.
“I have no regrets about my decision to defend Erhai’s ecosystem,” he said “It’s my job and responsibility.”
Now he’s savoring the bittersweet pleasure of “no pain, no gain.”
Large blooms of algae have disappeared. Last year, for seven months, the lake waters were certified as drinkable. In winter, people can clearly view 4 meters into the lake’s depth.
According to Kong, it’s a good start but not a perfect outcome.
“It will take at least another 25 years to restore the lake’s natural beauty and aquatic ecosystem,” he said. “There’s still much work waiting to be done. Striking a balance between environmental protection and economic progress is always a headache.”
Kong in the lab
Nowadays, Kong flies to Dali about 150 times a year, continuing to work with his students on the Erhai project.
Over years of research, Kong has found that the lake’s pollution started from agricultural runoff from the area’s once ubiquitous garlic farms and century-old cattle farms.
“Problems of water were caused by problems on land,” he said.
Dali’s purple-skinned garlic is one of the best garlic varieties in China because it contains more than five times as much garlic oil as other varieties. Much prized by foreigners, especially the Japanese, Dali garlic's prices soared 10-fold and more farmers turned to garlic cultivation. Garlic farms quickly occupied more than 90 percent of the crop acreage in Dali.
“One year of garlic revenue could be used to build a house,” Kong said. “I fully understand why local people wanted to plant garlic. However, few of them realized that the more they earned, the more severe the pollution they were causing. Excess fertilizers and pesticides flowed directly into Erhai. There were no sewage treatment facilities. As a result, the water because overly enriched with minerals and nutrients conducive to algae growth.”
Kong’s team introduced an advanced water treatment system that can handle 250 tons of sewage every day. The team worked with the local government in encouraging farmers to plant more non-polluting but high-profit crops, such as blueberries, grapes, apples, cherries and traditional Chinese medicinal herbs.
As old problems were solved, new ones appeared.
“In recent years, the No. 1 pollution culprit has turned from garlic farming to tourism,” Kong said. “Local officials thought tourism was a green industry and a perfect replacement for farming. However, that, too, bred pollution.”
The more people who visited the lake, the more people who wanted to live there. The area’s population has burgeoned to nearly 1 million, and that doesn’t include visitors.
Kong (center) and his fellow researchers on the way to a field study
Kong estimates the population capacity of the lake area is about a quarter of a million people.
Many of new residents are urban dwellers who have invested in hostels around the lake.
“Both Chinese and foreigners love Erhai, especially as urban areas have become plagued by air pollution,” said Kong. “We could say that every year there are 80,000 ‘migrants.’”
Under advice from Kong and other experts, the local government has drawn up a series of initiatives, including relocating businesses near the lake, suspending new construction projects and further regulating local farming.
“To deal with pollution is not just a matter of technologies,” Kong said. “It’s a matter of dealing with people.”
The problems suffered by Erhai Lake are not uncommon in Chinese waterways, especially in the rapidly developing Yangtze River Delta region, according to Kong. He has also been involved in cleanup efforts at Taihu Lake near Suzhou, West Lake in Hangzhou, Suzhou Creek in Shanghai and the Three Gorges in the upstream Yangtze River.
For him, anyone who could resolve the pollution of Taihu is qualified to be awarded the Nobel Prize.
“Algae bloom has started to appear in Taihu every May,” Kong said. “In summer, the lake stinks because dead algae emit a poisonous gas. It’s a smell you can never forget. Cows will die after drinking the polluted water.”
Given the circumstances, it’s almost an insolvable problem.
“Taihu is surrounded by a high-density populated area filled with textile mills, dye factories and other industrial sites,” he said. “If those factories were to be removed, it would deal a devastating blow to the local economy.”
Kong said one reason for optimism about the future is the awareness of the young generation about environmental protection. Last year, he started a foundation with 2 million yuan (US$294,117) of his own money to encourage students and young academics to continue his work.
