As a result of industrialization in China, some water sources in the country have fallen victim to contamination, as the number of sudden chemical leakages have increased in recent years.
While some cities are still figuring out how to deal with emergency water crises, others have been looking to create backup water sources to effectively cope with such accidents. It has not been easy.
In recent years the number of annual water pollution accidents in the country has risen to more than 1,700, according to statistics from the Ministry of Supervision.
In the second half of last year, at least three major water pollution incidents took place. Among them, the water source for Mianyang, Sichuan Province, was contaminated by waste chemicals from a manganese plant, and 500,000 residents' drinking water was affected.
In another recent incident, excessive cadmium levels were detected in the Hechi section of the Longjiang River in Liuzhou, Guangxi Zhuang Autonomous Region on January 15, with two companies suspected of discharging pollutants into the river.
Though city authorities took proper control of the situation by publishing real-time water sample test results via local media, the incident sparked days of panic buying of bottled water in Liuzhou.
This panic was the obvious result in cities that have a single water supply source when it is polluted, said Mu Jianxin, a senior engineer with the department of irrigation and drainage at the China Institute of Water Resources and Hydropower Research.
"For such cities, the only effective measure local authorities can take is to immediately cut off the polluted source and purify the water, which leaves people with only one other option," she told the Global Times.
Mu said that many Chinese cities have only a single source of water, which has always troubled local governments which, when trying to effectively ease the panic. They have to resort to ensuring the supply of bottled water and controlling prices.
Having learned lessons from harsh experiences, some cities have set about exploring the option of multiple water sources to handle possible emergency pollution accidents.
In 2007, industrial pollution caused an algae outbreak in China's third-largest freshwater lake, Taihu, which contaminated drinking water and forced millions of residents in Wuxi, Zhejiang Province to abandon tap water and sparked a panicked shopping spree for bottled water for more than a week.
In 2008, the completion of the Yangtze River's diversion project ended many cities' single water supply problem, including that of Wuxi.
Ye Jianhong, general manager of Mianyang Water Group, told the Economic Information Daily that frequent water pollution incidents have pushed them to quicken steps to build the second water supply source in Mianyang, and the location of the source has been fixed.
Experts affirm the effectiveness of the measure in alleviating any crisis, but have concerns about the necessary conditions needed to explore a multi-source supply solution.
The cost of drilling a well for a backup water source is about 700,000 yuan ($111,160), and after adding daily maintenance expenses, the annual fee is about 1 million yuan, the Economic Information Daily reported.
"With such a high cost, it is definitely worth taking other options into consideration," Liu Shukun, a professor at the China Institute of Water Resources and Hydropower Research, told the Global Times.
In some places, water is usually collected in a reservoir set aside for emergency use, and the water stored there is not allowed to be used for any other reason, he said.
As early as the 1950s, the need for backup water sources was taken into consideration when building a city's water system, said Liu.
"However, these backups were designed to solve water crises caused by wars, terrorist incidents or natural disasters, not man-made contamination," Liu said.
"Our attempts to explore alternative water sources pale in comparison to the number of man-made contamination incidents, which could have been avoided," he said.
He believes that with strict government supervision, incidents of plants discharging unsafe pollutants, and vehicles and vessels spilling chemical materials, can be prevented.
Mu suggested that cities should not rely on backup water sources as their only solution to the issue.
She said that ground subsidence has frequently happened in North China because of the over-exploitation of underground water supplies.
Liu Chunzhen, a researcher at the Hydrological Forecasting and Water Control Center, said that due to the fast development of industries, more and more pollutants are discharged into rivers.
"The convenience in using water becomes a main reason for plants to select locations near rivers or lakes, threatening the drinking water safety in the surroundings and downstream areas," she told the Global Times.
"The government needs to strengthen the supervision of chemical plants and seriously punish those violating regulations. Enterprises should also improve their sense of responsibility to reduce water pollution accidents," said Liu Shukun.
A notice about implementing stricter water resource regulations released by the State Council was publicized last week, and said it will take "the strictest measures" to ensure local water safety.