6 Water Contamination and Water Scarcity
6 Water Contamination and Water Scarcity
- Daniel K. Gardner
What Is Contaminating China’s Water Resources?
Viewed in the context of the skyrocketing industrialization, urbanization, and population growth of the past 30 years, the widespread contamination of the water supply that now plagues China would seem almost inevitable. Yet, because the country’s water has been far less monitored than its air, and the data available to us are spotty and not very reliable, our present understanding of China’s water situation is still quite limited. The good news is that in recent years investigation into China’s water quality has become a high priority for the government—though critics maintain it has often been slow to release the information it collects.
China rates water quality using a five-point scale. Grades I through III are fit for fish habitat and drinking (with some degree of treatment). Grade IV is fit for industrial use and recreational activity in which there is no human contact with the water. Grade V is fit for agricultural and landscape use only. (Yes, this means—strangely—that water unfit for human touch and industrial use can nonetheless be used to grow crops that people eat.) A grade V+ is sometimes used to refer to water that is entirely unusable for either industry or agriculture.
p. 76↵To understand just how dire the condition of China’s water supply is, consider the following:
60% of the country’s groundwater is grade IV or V/V+ (unfit for drinking and human contact).
70% of the groundwater in the densely populated North China plain is grade IV or V/V+.
50% of the country’s shallow groundwater is grade IV or V/V+.
50% of water from rivers, lakes, and waterways is grade IV or V/V+.
90% of river water in urban areas is polluted.
More than 70% of 641 drinking wells tested by China’s Ministry of Environmental Protection in 2009 were classified grade IV or V/V+.
300 million people (about 25% of the population) have no access to drinking water.
The Danjiangkou Reservoir, which supplies Beijing with much of its drinking water, was found to have levels of lead 20 times higher than WHO standards in 2007–2010.
While air pollution in China has tended to receive more attention than water pollution—perhaps simply because sooty smog is much harder to ignore—the figures here help to explain why many are coming to view the contamination of the country’s water supply as an equal, perhaps even graver, environmental threat.
Contamination of the country’s water resources is owing mostly to industrial pollution, agricultural runoff, and human sewage. Industry and agriculture are the two largest water polluters nationwide, agricultural being the dominant polluter in the countryside, industry in the cities.
For decades, paper mills, chemical factories, steel plants, drug manufacturers, fertilizer and pesticide producers, textile plants, and tanneries have discharged waste and dumped chemicals directly into the country’s waterways (Figure 6.1). p. 77↵Lax laws and even laxer enforcement—which we will consider in Chapter 11—have encouraged water degradation. With little risk of being found in violation of environmental regulations, industries have opted to pollute rather than to incur the costs of proper waste treatment and disposal.
An equally large share of water pollutants comes from the agricultural sector. Pesticides and fertilizers used for crop production are carried by rain, snowmelt, and irrigation into rivers, lakes, wetlands, coastal waters, and underground aquifers. (Phosphorous and nitrogen from fertilizer runoff, for example, make for the spectacular blue–green algal blooms in China’s streams, lakes, and coastal areas.) In 1967 China’s eutrophic lakes covered 52 square miles; in 2007 they had expanded to 3,360 square miles. In that year, 70% of Lake Tai, the country’s third largest freshwater lake, was blanketed in a sheet of algal bloom nine inches thick.
Fecal waste from livestock production also makes its way into the country’s water supply, either through direct excretion or through runoff carried by rain, melting snow, and irrigation. p. 78↵In recent decades the livestock population in China has grown considerably (due to population growth and changes in diet). And before the turn of the 21st century, most livestock were produced by small farmers raising 2 to 20 animals annually, while today, factory farms (concentrated animal feeding operations) that produce thousands of hogs every year have become more usual. Human waste is also a significant pollutant, and not only in the countryside as one might imagine. In one study, 80% of 278 cities were found to lack sewage treatment facilities. With no sewage treatment plants, there are few places for the waste to go. It is estimated that roughly 90% of all household sewage in China is released into rivers and lakes without being treated.1 As the urbanizing trend grows, domestic sewage discharge is increasing at a faster pace than industrial discharge.
One final source of water pollution should be noted: industrial accidents. This should not surprise us given the number of factories located along the country’s rivers and lakes. Ten thousand petrochemical factories alone sit alongside the Yangtze River and 4,000 on the Yellow River. When accidents in factories on the water occur, as they inevitably do, water supplies in the surrounding region can be profoundly compromised:
In July 2010 two oil pipelines in the northern port city of Dalian exploded, sending 1,500 metric tons of crude oil into the bay off Dalian’s coast, resulting in a 165-square-mile slick.
In December 2012, 39 tons of toxic anilines leaked from a ruptured drainage pipe belonging to the Tianji Coal Chemical Industry Group into the Zhuozhang River, severely contaminating the source of the drinking water for Changzhi, a city in Shanxi province. It then traveled farther downstream, through 28 more villages and cities, before reaching Handan in Hebei province.
In November 2013, an oil pipeline belonging to Sinopec, one of the country’s largest oil companies, exploded in the eastern port city of Qingdao in Shandong province, p. 79↵killing at least 62 people; oil spilled into the rainwater drainage pipeline and contaminated the nearby seawater in Jiaozhou Bay.
In April 2014, a toxic oil leak in a Lanzhou Petrochemical pipeline released high levels (20 times the national safety standard) of the carcinogen benzene into the local water supply in Lanzhou, a city of 2.5 million in China’s northwest. Residents were ordered not to drink the tap water; panic buying of bottled water ensued and the price per bottle shot up from $1 to $6.
What Are the General Consequences of Polluted Water?
The context here is crucial. China already has a scarcity of water: it has 21% of the world’s population but just 6% to 7% of the world’s freshwater resources. When rivers and lakes are contaminated with industrial pollutants and agricultural runoff, the country’s water supply is significantly reduced, thereby worsening an already very bad situation.
Given the scarcity of water, many people have little choice but to drink water that is classified as unfit to drink or even touch. Various studies, including one in 2009 by the World Bank, concluded that 300 million people in China do not have access to safe drinking water. And this number assumes that the piped water in urban areas is regularly treated, which some observers doubt.2
Every year 190 million people in China—roughly 14.5% of the country’s population—fall ill from drinking contaminated water. Diarrhea is by far the most prevalent of water-related diseases in China. According to a WHO report, in 2008 there were more than 487 million cases, resulting in almost 67,000 deaths. Children, because their intestinal systems are not as well developed, were hit hardest, accounting for 83% of all cases and 97% of the deaths.3
Even simple physical contact with contaminated water—when farming, swimming, bathing, and so forth—puts people p. 80↵at risk of infection from parasites, which in larval form can penetrate the skin. Children, because of their play habits and hygiene, are especially vulnerable to parasitic infection. It is estimated that today 865,000 Chinese people are infected with schistosomiasis, an intestinal disease caused by contact with fresh water infested with snails carrying the parasitic flatworms called schistosomes, and 30 million people living in tropical and subtropical zones are at risk of infection.4 Scientists fear that as water temperatures rise with global warming, the transmission of schistosomiasis is likely to expand.
According to China’s water-quality grading system, water that is unfit to drink is not necessarily unfit for agricultural use. Water that is too polluted for drinking or for use in industry can, as we have seen, be used to irrigate fields. Eating crops grown in these fields exposes people to some of the same health problems that drinking untreated water might—as well as other problems. Many farmers, according to media reports, are hesitant to eat the very food they have grown. As Hu Kanping of the Chinese Ecological Civilization and Research and Promotion Association said, “Farmers won’t eat what they produce. They have fields for themselves and fields for the market.”5 In short, water contamination poses a real threat to the safety and security of China’s food supply.
Today cancer is the leading cause of death in China. Lung cancer is the form that takes the most lives; next come the various digestive cancers—stomach, liver, and esophageal—which account for 1 million deaths every year. The high incidence of digestive cancers has given rise to hundreds of “cancer villages” along the rivers in China’s countryside. Although hard scientific research analyzing the precise relationship between digestive cancer and contaminated water is still limited, one recent, quite rigorous study estimated that deterioration of water quality by a single grade leads to a 9.3% increase in the incidence of digestive cancer.6
Fish and marine mammals also suffer from contaminated water. Contamination, of course, is only one of the factors p. 81↵accounting for the reduction of freshwater wildlife in China’s waterways (along with overfishing, loss of habitat, and river traffic), but it is a key factor. Indeed, it is often given as one explanation for the disappearance of the famous baiji, the Yangtze River dolphin, which was declared “functionally extinct” after a 45-day expedition in 2006 failed to detect any surviving specimen. At present, the Yangtze finless porpoise is “endangered” and on the verge of extinction, owing to much the same causes that made for the baiji’s demise.
Isn’t Water Scarcity a Bigger Long-Term Problem Than Water Contamination?
More than two-thirds of China’s 600-plus cities suffer from water shortages, but it is the per capita figures that really indicate just how grim China’s water situation is. The annual global per capita availability of fresh water is roughly 6,000 m3; China’s is one-third of that, at 2,000 m3. (The United States, by comparison, has 9,000 m3 per capita per year.)
This is not the whole story, however, because there is a wide discrepancy in regional precipitation patterns: northern China receives 20% of the country’s rainfall and snowmelt against southern China’s 80%. The north, as a result, is far more arid. In Beijing, for instance, the annual per capita water availability is 100 to 150 m3, not even 1/40th the world’s average, and well below the UN’s threshold of “absolute scarcity” (500 m3) (Figure 6.2).
According to the government, agriculture and coal consume most of the country’s available water. It is estimated that 65% to 70% of the water resources are used in the agricultural sector and 20% in the coal industry (to extract, wash, and combust coal), with little remaining for other uses. Cultivating one bowl of rice requires one bathtub full of water (70 gallons); processing one ton of coal requires somewhere between 800 and 3,000 gallons of water. Unfortunately, the agricultural and coal industries are largely concentrated in the north, where water p. 82↵and precipitation are extremely limited. (Two-thirds of the country’s cropland and most of the country’s coal industry are in the north.) The heaviest demand on China’s water resources, thus, is precisely in the region of the country where they are least plentiful.
With precipitation and river runoff insufficient to meet the country’s needs, especially in the north, China has drawn more and more on its groundwater. But experts worry that the groundwater is being withdrawn much too quickly, well beyond its recharging capacity. In many parts of the north, the water table has fallen to 328 to 984 feet (100–300 meters) below the ground, mostly within the past two decades.
p. 83↵Climate change is expected to make matters worse. If, as forecast, temperatures rise, evaporation is likely to increase, further stressing water resources. Climate experts also predict that, with the warming air, precipitation patterns will change; the south, they say, will get more moisture and today’s dry north will get still less. Already, droughts in the Hai, Yellow, and Huai River areas have caused billions of dollars in losses. If the Himalayan glaciers in the west continue to melt and recede (having already shrunk by one-third over the past century), as all scientific studies suggest, the ice melt they provide to the east-flowing Yellow and Yangtze Rivers will decline by as much as 25% by 2050. This could be catastrophic for agriculture—and the people—along these rivers.
In the north and northwest, the shortage of precipitation, combined with overextraction of water, overlogging, and overgrazing, has already produced an ecological nightmare. Over 1 million square miles of China’s land has become desert—that is, 27% of all of China’s land. Four hundred million people have been affected by this massive desertification. Some of them have had little choice but to become ecological migrants, fleeing their homes in search of land that can sustain them. In 1978, in an attempt to fend off the desert’s expansion, the Chinese people launched the world’s largest tree-planting project ever. Since then they have planted 66 billion trees along the edges of the country’s northern deserts. Like the Great Wall, this “great green wall” is intended to be a defensive structure, though this time the enemy is desertification, not nomadic invaders. When the project is completed, in 2050 or so, the wall of trees is expected to stretch more than 2,800 miles. Whether, ultimately, it will be any more successful than the Great Wall in keeping the enemy at bay is open to much debate.
Water scarcity on occasion can lead to conflict between villages, as it has, for example, along the Zhang River, a tributary of the Hai River that flows between Henan and Hebei provinces. In the 1950s, with the population p. 84↵growing, villagers in the region became increasingly intent on protecting the water needed for their agriculture. In the 1970s, villages along the Zhang even established militias to defend their water allocations. Occasional violence would erupt and, in 1976, one of the local militia chiefs was shot to death. By the 1990s, violence had escalated and the exchange of mortar fire between villages was not uncommon. On Chinese New Year in 1999, two of the villages took to bombing each other, injuring nearly 100 people and doing $1 million worth of damage to homes and water facilities in the area.7
A variety of measures to alleviate the country’s water stress have been proposed. Those that have attracted the most interest include the following:
Increasing the price of water, which now costs $0.46 per m3 (vs. the global average of $2.03 per m3)
Implementing some sort of tiered pricing system for water
Improving irrigation efficiency
Charging farms based on the actual amount of irrigation water they use (volumetric pricing) rather than by acreage of land, as is still the case in many places
Developing cost-effective desalination technology and plants
Building a 100-mile-long canal from Tianjin to Beijing to carry potable, desalinated water from the Bohai Gulf
Strengthening management of the country’s water resources
Increasing the country’s food imports in order to conserve on agricultural water
How Have Groundwater Levels Become So Dangerously Low?
An increase in industrialization, urbanization, and population beginning in the mid- to late 20th century has resulted p. 85↵in the increasing depletion—and pollution—of China’s surface waters. In recent years, a decrease in precipitation has further diminished its water resources. Consequently, China has turned more and more to its groundwater supply. Between 1949 and 2004 water use across the country increased, leading to an inevitable drop in groundwater levels.8 China Water Risk estimates that today over 400 of the 655 cities in China rely on groundwater as their primary source of drinking water.9 The north has been especially affected, as municipalities, industry, and agriculture there have all become dependent on groundwater for a significant share of their water needs—65%, 50%, and 33% respectively. As a result, in the north, groundwater levels have been dropping 3.3 feet (1 meter) every year.
Most aquifers are rechargeable (i.e., replenishable) through rainfall, although fossil aquifers are not. But China is drawing from the groundwater at too fast a rate for it to recharge adequately.
A related problem is the country’s rapid development and urbanization. Land that was once permeable and allowed rainwater and water runoff to seep into the ground is now covered with impermeable surfaces like asphalt and concrete, meaning that the recharging rate has slowed substantially in the past couple of decades.
So now the groundwater itself is being depleted, a cause for deep concern. As recently as 2008, workers in Beijing could drill a couple of hundred feet and hit groundwater, but in 2010, they had to drill over 1,000 feet (305 meters) to reach it. The World Bank reports that some wells in Beijing must be drilled a half-mile (0.8 km) deep before hitting water. Villages throughout Hebei province, which surrounds Beijing, now have to dig 650 feet (198 meters) to find clean water, when just a few years ago it could be found at just over 65 feet (20 meters).
At 650 feet or 1,000 feet, accessing water is a challenge, and it is expensive. At these depths, tube wells are required. In a tube well, a metal tube or pipe is bored into the underground aquifer; equipped with a pump and filter, the tube then brings p. 86↵the groundwater to the surface. In 1965, there were about 150,000 of these wells throughout the country; by 2003 there were 4.7 million. This expansion represents a huge increase in the cost of accessing the water supply.
There are serious secondary consequences to groundwater depletion. One is subsidence, the sinking of land that results from the extraction of groundwater. Groundwater produces an upward pressure on the layers of soil above it; as the amount of pressure is reduced, through depletion, there is less support for that soil and so it begins to settle or sink, sometimes even collapsing in on itself. Subsidence can do real harm: it can damage buildings; rupture water, gas, and electric lines; buckle highways and rail systems; and increase the risk of flooding. More than 50 Chinese cities are experiencing subsidence. The city of Tianjin has been especially hard hit: in 2008, an area of 43,090 square miles (111,602 km2) was found to have sunk 10.5 feet. Shanghai, the country’s most populous city, has sunk more than 8 feet (2.4 meters). And one recent study concluded that Beijing is sinking by more than 4 inches (10.2 cm) annually.10
Another serious consequence is saltwater intrusion. This occurs when groundwater near the ocean is overextracted and the water table declines, allowing salt water to flow in and fill up the empty space in the aquifer. The intruding salt water can result in the contamination of the aquifer and soil salinization. Looking down the road, if China continues to overextract its groundwater, and if, as climate scientists predict, sea levels rise from global warming in the coming decades, the incidence of saltwater intrusion in China’s aquifers—and the problems associated with it—could escalate steeply.
Why Are Some of the Rivers, Even Major Ones like the Yellow River, Drying Up?
Rivers all over China are drying up, even disappearing. History had never recorded a “no-flow” day for the mighty p. 87↵Yellow River until 1972: for 15 days that year, the water ran so low that the river failed to reached its outlet in the Bohai Sea. From 1972 to the mid-1990s there were intermittent recurrences of this sort of dry-up. Then, in 1996, “Mother River,” as the Chinese people have long called it, failed to make it to the sea for a full 133 days. The next year was worse: the river ceased flowing for 236 days.
The Haihe or Hai River flows through Beijing and Tianjin before emptying into the Bohai Sea. The volume of water in the Hai River has declined drastically in recent years as many of the smaller tributaries that feed it, and some of the major ones as well, have become dry river beds (about 2,500 miles [4,023 km] in total) for most of the year. In 2001, Xinhua news reported that the wetlands area along the Hai River had shrunk by 80% over the past 50 years, from 1,465 square miles (3,794 km2) to 207 square miles (536 km2).
In 2005 China’s Ministry of Water Resources reported that of the 541 rivers it had surveyed, 60 had run dry in 2000. And in 2013, according to China’s “First National Census of Water,” of the 50,000 rivers with a flow area of 60 square miles (155 km2) or more that were recorded in 1950, only 22,909 were found by surveyors; the other 27,000 could not be found.11 Poor water-management programs and excessive withdrawal for irrigation are thought to be the likely causes (though some Chinese officials have argued that the 1950 figure of 50,000 was based on inaccurate estimates by cartographers using poor mapping techniques). Whatever the precise number, the trend is clear: China’s waterways are drying up.
A number of factors, mostly already familiar to us, explain the trend. First is population growth. The jump from 541 million people at the founding of the People’s Republic to 1.38 billion today has necessarily resulted in far greater extraction of natural resources like water. A significant share of river water is siphoned off for irrigation use, especially in the north, where water-intensive crops like wheat are grown and rainfall is slight. Industrialization, which has been the driver p. 88↵of the Chinese economy over the past 30 years, has brought a high demand for energy, especially coal, and, as we have seen, coal extraction, washing, and processing place a huge stress on water resources. China is attempting to turn from coal to other sources of energy in order to decarbonize, yet some of these sources—gas, nuclear, and hydropower—also require a great deal of water. Another factor explaining the “dry-up epidemic” is water diversion: water from rivers is increasingly being diverted to dams (built to control flooding and to generate hydroelectricity), reservoirs, and cities to supply the water needs of the increasingly urban Chinese population, roughly 700 million people.
Climatic changes factor in too. Scientists have calculated that from the 1950s to the 1990s years there was a 2.30°F (1.28°C) rise in air temperature in the Yellow River basin.12 The warmer air has resulted in increased evaporation of the surface water and increased evapotranspiration by plants, which then require more watering. This century has also seen an increase in droughts, in both the north and the south. A March 2009 drought in China’s southwest provinces reduced precipitation there by 90%; in 2011 a drought in the Yangtze River basin left more than 3 million people without sufficient water. In both cases, when the rains returned, they caused damaging flooding.
Finally, Chinese industry’s inefficient use of water is a factor in the widespread river dry-up. It is estimated that Chinese industry uses somewhere between 4 and 10 times more water per unit of production than the average among developed countries.13 Further, according to the World Bank, Chinese industry recycles only 40% of its water, compared to 75% to 85% in developed countries.14
What Is the South-North Water Diversion Project?
In a country where 80% of the relatively scarce water resources are in the south and just 20% in the north, where the population p. 89↵is split roughly evenly between the two regions (53% in the south, 47% in the north), and where 66% of the agriculture is in the north, the question of how the country’s water resources might be more equitably distributed arises naturally. In the 1950s, Chairman Mao, during an inspection tour of the south, observed, “The south has plenty of water, but the north is dry. If we could borrow some, everything would be okay.”
That is what the South-North Water Diversion Project, which broke ground in 2002, aims to do. The three channels (an eastern channel, a central channel, and a western channel) will move water from the wet south to the water-deprived north. Together the three channels will run more than 2,000 miles (3,219 km).Considered by many the biggest engineering project in history, it will move 45 billion m3 of fresh water every year from the Yangtze River to the arid north.15
The eastern and central channels have been completed. As Figure 6.3 shows, the eastern channel originates in the lower Yangtze and threads its way north to the metropolis of Tianjin; the central channel begins at the Danjiangkou Reservoir and carries southern waters northward to Beijing (Edward Wong of the New York Times wrote that this was “like channeling the Mississippi River to meet the drinking needs of Boston”16). The western channel, connecting the headwaters of the Yangtze River to the headwaters of the Yellow River, is the shortest but technically the most difficult, as it will move water from the Yangtze across the eastern Himalayas; it is still in the planning stages and is not scheduled for completion until 2050. The cost of the transfer project thus far is $80 billion.
As desperate as the north may be for water, the South-North Water Diversion Project has raised many concerns. The eastern channel was constructed largely by linking up existing canals, rivers, and lakes, but much of the water in these waterways is polluted. Will the eastern channel simply be moving polluted water north? More than 400 wastewater treatment plants have been built along the channel (which come at a cost and require energy to run), but how effective will they be in treating the p. 90↵water arriving in the north? For the moment, officials in the city of Tianjin say they still prefer to desalinate water—an expensive process—rather than drinking water pumped from the south through the eastern channel.
Cities and provinces along the channels have argued that they are being robbed of water in order to supply Beijing. For instance, officials in Hebei province say that in recent years the amount of available water in Hebei and its capital city of Shijiazhuang has declined by 50% as a result of the diversion project.
Estimates of the amount of runoff that will be diverted from the Yangtze vary. Most experts suggest roughly 5%, but some add that it could increase to as much as 20%, depending on the season and the weather. Whatever the amount, there is worry that the Yangtze and the cities and villages it serves will pay a price. In the last four decades, the amount of water entering the Yangtze from Tibetan glaciers has decreased 15%; p. 91↵as the glaciers melt and recede over the course of this century this figure is expected to escalate. Thus, diverting even 5% of the Yangtze’s annual runoff would be significant. Experts in Hubei’s capital, Wuhan, a city of 8.3 million, contend that diverting water away from the Yangtze, the source of the city’s entire water supply, especially during periods of lower runoff, puts Wuhan at grave risk. They wonder why supplying north China with water should be a higher priority to the state than maintaining a healthy water supply in their city. Meanwhile, Sichuan province has submitted an official complaint to the central government about the likely effects that the still-unbuilt western pipeline would have there: not only are water levels already dropping, but water pollution is a widespread problem.17 The question that many critics of the project have is simply this: Will supplying the north lead to scarcity in the south?
There is also concern about the transmission of waterborne diseases from south to north. For instance, schistosomiasis, the chronic parasitic snail-borne disease mentioned above, has so far been limited largely to the lower reaches of the Yangtze River. However, some scientists believe that as water is diverted north from the Yangtze, the possibility of the disease spreading northward is very real.
Diverting water from the Yangtze poses risks to the health of the river itself. A decline in water level increases the likelihood that salt water will intrude into its estuaries. And a lower volume of water (and thus a slower flow) weakens the river’s “environmental capacity” (its ability to clean itself of pollutants introduced into its waters). Today, roughly 40% of the country’s wastewater is dumped into the Yangtze River, and diverting the water means there will be less water in the river to dilute the pollution.18
Finally, building the canals has required a massive relocation. More than 330,000 people have been forced to move from their homes to make way for the construction of the central channel and the expansion of the Danjiangkou Reservoir that feeds it.