**5. Aquifers and water resources: hydrofracking's threat to water quantity and water resources**

In terms of aquifers, hydrofracking presents two threats: it uses too much water, and the water it uses becomes polluted and unfit for any other use. This section will address the threat hydrofracking poses to water resources due to imposing a new demand on already stretched water resources. Hydraulic fracturing as a technology is well known as a water hog. The volume of water used per well depends on the length of the horizontal borehole and the formation, but it is not unheard of for a single well to use 20 million liters. This is a consumptive use of water, in that once the hydrofracking chemicals are added and the water is injected into the subsurface, it cannot be reused. For perspective, consider that 20 million liters of sufficient water to meet the basic needs and few health concerns arise for approximately 200,000–400,000 people, according to the World Health Organization [7]. And, that is just the water used for a single well!

As with the most water resource problems, the geographic distribution of available water resource and water need may not align. A look at the hydrofracking experience in the USA is illustrative. Some shale gas formations underlie areas of abundant water, such as the Marcellus shale and Utica shale in the Northeastern USA. This area is well supplied with rivers, lakes, and abundant groundwater. The area is humid and receives on the order of 100 cm of precipitation annually. In contrast the Uinta-Piceance Province in Colorado, located in the Western USA,

The technological revolution that has transformed the oil and gas proven reserve and production story in the USA is beginning to affect production worldwide. The US Energy Information Administration has found that tight shale gas and tight shale oil resources are distributed

**Figure 1.** Natural gas production in the USA in billion cubic feet per day (2000–2015) [5]. Conventional gas shown in

around the world (**Figure 2**).

**Figure 2.** Basins with assessed shale oil and shale gas formations [6].

dark shading and shale gas shown in light shading.

36 Aquifers - Matrix and Fluids

is located mainly in an area of high desert. The waters of the Colorado River are already over allocated, yet energy companies have secured over a million acre-feet (1.25 billion cubic meters) of water rights. Many of the shale gas formations poised to make a significant contribution to the world's natural gas production are also found in areas already experiencing water stress.

Some of China's potential shale gas fields underlie areas already experiencing water stress. The statement of [12] indicates that fracking in the Sichuan Basin will compete with domestic water needs in an area that is already water stressed, but the specter of additional desertification and diversion of water for hydrofracking has not deterred multinational oil and gas companies. Chinese energy companies Sinochem, Sinopec, and CNOOC have invested in US shale gas operations such as Chesapeake Energy partly to gain access to hydrofracking experience. Major western energy companies including ExxonMobil and Chevron have initiated joint ventures in Chinese shale gas. The US shale gas boom in formations such as the Bakken in Texas and the Marcellus in Pennsylvania has taken place in nearly horizontal, relatively shallow formations. Many of China's most promising formations are deeper and in more complex geology, indicat-

Effect of Hydrofracking on Aquifers http://dx.doi.org/10.5772/intechopen.72327 39

ing that it will take even more water per well to successfully frack the formations [13].

areas will continue to be at least as water short as they are presently.

**Figure 3.** China's annual water resources per capita (m<sup>3</sup>

**Figures 3** and **4** show current water scarcity in China and shale gas plays in China, respectively. Development of shale gas basins in the northern area in particular will compete with other uses for scarce water. Both the Bohai Bay Basin and the Ordos Basin are found in areas already classified as under extreme water scarcity. Population will grow, industry will expand, and agriculture will struggle to keep up with growing food demand; each of these

) by province (2003–2010 average) [15].

The World Resources Institute reports that China, India, Pakistan, Mexico, and South Africa are among the top 20 countries in the world in terms of shale gas potential, but each may have insufficient unallocated water to develop this resource [8]. Currently, farmers in China, India, and Pakistan use tube wells and electric pumps to pull 400 billion cubic meters of groundwater out of aquifers annually. This volume exceeds recharge by an estimated 170 billion cubic meters per year [9]. The three countries combined are responsible for more than half of the world's agricultural use of groundwater. Water is in such short supply near major cities in parts of Asia that untreated sewage is used to irrigate crops. It is estimated that a quarter of all of Pakistan's vegetables are irrigated with sewage. These are not countries with excess water waiting to be used for hydrofracking! **Table 2** lists 20 countries with the largest technically recoverable shale gas resources by average exposure to baseline water stress over shale play area.

If a significant shale gas resource exists in a water short area, the problem is likely not that there will be insufficient water to develop the lucrative natural gas resource. The problem is more likely that the water for hydrofracking will be diverted from some of the use. There will be winners and losers.

One country to consider is China. It is estimated that China has twice the shale gas resource of the USA, over 1100 trillion cubic feet. This is enough to be a significant factor in China's transition toward a cleaner energy future. China currently uses coal to provide 62% of its total energy output [10]. It has been said that shale gas on its worst day is better than coal on its best day; so to any extent possibility, a transition from coal to shale gas could be a positive development. Shale gas, photovoltaics, and wind power will likely all be part of the mix used to wean China away from coal as it strives to meet its obligations under the Paris agreement.

China is the world's most populous country. In his book *When the Rivers Run Dry*, Fred Pearce states that "If northern China were a separate country it would be one of the most waterstressed in the world." The World Bank estimates that China has already lost 14 billion dollars in industrial production due to water shortages. More than a quarter of China's landmass is already a desert. The Gobi, the fastest-expanding desert on earth, grows toward Beijing at a rate of 2 miles per year. It has been estimated that the country lost more than 6% of its farmland to desertification between 1997 and 2008 [11].


**Table 2.** Baseline water stress over shale play area.

Some of China's potential shale gas fields underlie areas already experiencing water stress. The statement of [12] indicates that fracking in the Sichuan Basin will compete with domestic water needs in an area that is already water stressed, but the specter of additional desertification and diversion of water for hydrofracking has not deterred multinational oil and gas companies. Chinese energy companies Sinochem, Sinopec, and CNOOC have invested in US shale gas operations such as Chesapeake Energy partly to gain access to hydrofracking experience. Major western energy companies including ExxonMobil and Chevron have initiated joint ventures in Chinese shale gas. The US shale gas boom in formations such as the Bakken in Texas and the Marcellus in Pennsylvania has taken place in nearly horizontal, relatively shallow formations. Many of China's most promising formations are deeper and in more complex geology, indicating that it will take even more water per well to successfully frack the formations [13].

is located mainly in an area of high desert. The waters of the Colorado River are already over allocated, yet energy companies have secured over a million acre-feet (1.25 billion cubic meters) of water rights. Many of the shale gas formations poised to make a significant contribution to the world's natural gas production are also found in areas already experiencing water stress. The World Resources Institute reports that China, India, Pakistan, Mexico, and South Africa are among the top 20 countries in the world in terms of shale gas potential, but each may have insufficient unallocated water to develop this resource [8]. Currently, farmers in China, India, and Pakistan use tube wells and electric pumps to pull 400 billion cubic meters of groundwater out of aquifers annually. This volume exceeds recharge by an estimated 170 billion cubic meters per year [9]. The three countries combined are responsible for more than half of the world's agricultural use of groundwater. Water is in such short supply near major cities in parts of Asia that untreated sewage is used to irrigate crops. It is estimated that a quarter of all of Pakistan's vegetables are irrigated with sewage. These are not countries with excess water waiting to be used for hydrofracking! **Table 2** lists 20 countries with the largest technically recoverable shale

gas resources by average exposure to baseline water stress over shale play area.

be winners and losers.

38 Aquifers - Matrix and Fluids

land to desertification between 1997 and 2008 [11].

Estimated shale gas in trillion cubic feet in brackets. Data source: [8].

**Table 2.** Baseline water stress over shale play area.

**Extremely high High Medium to high Medium to low Low**

Pakistan (105) China (1115) USA (567) Argentina (802) Australia (437)

Mexico (545) Paraguay (75) Canada (573) Russia (287) S. Africa (390) Poland (148) Brazil (245) India (96) France (137) Venezuela (167)

Ukraine (128) Columbia (55)

If a significant shale gas resource exists in a water short area, the problem is likely not that there will be insufficient water to develop the lucrative natural gas resource. The problem is more likely that the water for hydrofracking will be diverted from some of the use. There will

One country to consider is China. It is estimated that China has twice the shale gas resource of the USA, over 1100 trillion cubic feet. This is enough to be a significant factor in China's transition toward a cleaner energy future. China currently uses coal to provide 62% of its total energy output [10]. It has been said that shale gas on its worst day is better than coal on its best day; so to any extent possibility, a transition from coal to shale gas could be a positive development. Shale gas, photovoltaics, and wind power will likely all be part of the mix used to wean China away from coal as it strives to meet its obligations under the Paris agreement. China is the world's most populous country. In his book *When the Rivers Run Dry*, Fred Pearce states that "If northern China were a separate country it would be one of the most waterstressed in the world." The World Bank estimates that China has already lost 14 billion dollars in industrial production due to water shortages. More than a quarter of China's landmass is already a desert. The Gobi, the fastest-expanding desert on earth, grows toward Beijing at a rate of 2 miles per year. It has been estimated that the country lost more than 6% of its farm**Figures 3** and **4** show current water scarcity in China and shale gas plays in China, respectively. Development of shale gas basins in the northern area in particular will compete with other uses for scarce water. Both the Bohai Bay Basin and the Ordos Basin are found in areas already classified as under extreme water scarcity. Population will grow, industry will expand, and agriculture will struggle to keep up with growing food demand; each of these areas will continue to be at least as water short as they are presently.

**Figure 3.** China's annual water resources per capita (m<sup>3</sup> ) by province (2003–2010 average) [15].

**Figure 4.** China's shale gas distribution [16].

A rather extreme case of competition between current water demand and the coming demand from hydrofracking is illustrated by Algeria. Algeria is estimated to have the third largest reserve of technically recoverable shale gas in the world, after China and Argentina. Its two significant shale gas formations are the Frasnian Shale and the Tannezuft Shale. These are found in multiple basins throughout the southern portion of the country [14]. Algeria is dependent on domestic gas production for energy. More than 60% of Algeria's energy needs are currently met with domestic production of conventional gas, but the output has been declining. Algeria will not be able to leave the shale gas in the ground.

**Figure 5.** Annual precipitation in Algeria [17].

Effect of Hydrofracking on Aquifers http://dx.doi.org/10.5772/intechopen.72327 41

**Figure 6.** Location of shale gas basins in Algeria [14].

Few countries on earth are as dry as Algeria. Over 80% of the country is located within the Sahara desert. Only the northern coastal portion of the country is temperate, but it becomes hotter and dryer away from the coast and the coastal mountains. The majority of the country located above the shale gas formations receives little to no rainfall. Annual precipitation is less than 10 cm per year for the majority of the country. Except for the coastal area, all surface water is ephemeral, with wadis draining to sebhkas—closed internal basins with high evaporation [17].

**Figure 5** shows annual precipitation in Algeria. **Figure 6**, showing the location of shale gas basins in Algeria, indicates that all of the resource exists in areas of the country that receive less than 10 cm of precipitation annually. The population away from the coastal areas is entirely dependent on water pumped from deep aquifers. In that there is no recharge, they are essentially mining their non-renewable groundwater from aquifers below the Sahara. The aquifers used for water supply include moderate to high permeability unconsolidated material, sedimentary rock layers, and karst rock layers.

**Figure 5.** Annual precipitation in Algeria [17].

A rather extreme case of competition between current water demand and the coming demand from hydrofracking is illustrated by Algeria. Algeria is estimated to have the third largest reserve of technically recoverable shale gas in the world, after China and Argentina. Its two significant shale gas formations are the Frasnian Shale and the Tannezuft Shale. These are found in multiple basins throughout the southern portion of the country [14]. Algeria is dependent on domestic gas production for energy. More than 60% of Algeria's energy needs are currently met with domestic production of conventional gas, but the output has been declining. Algeria will not be able to leave the shale

Few countries on earth are as dry as Algeria. Over 80% of the country is located within the Sahara desert. Only the northern coastal portion of the country is temperate, but it becomes hotter and dryer away from the coast and the coastal mountains. The majority of the country located above the shale gas formations receives little to no rainfall. Annual precipitation is less than 10 cm per year for the majority of the country. Except for the coastal area, all surface water is ephemeral,

**Figure 5** shows annual precipitation in Algeria. **Figure 6**, showing the location of shale gas basins in Algeria, indicates that all of the resource exists in areas of the country that receive less than 10 cm of precipitation annually. The population away from the coastal areas is entirely dependent on water pumped from deep aquifers. In that there is no recharge, they are essentially mining their non-renewable groundwater from aquifers below the Sahara. The aquifers used for water supply include moderate to high permeability unconsolidated material, sedi-

with wadis draining to sebhkas—closed internal basins with high evaporation [17].

gas in the ground.

40 Aquifers - Matrix and Fluids

**Figure 4.** China's shale gas distribution [16].

mentary rock layers, and karst rock layers.

**Figure 6.** Location of shale gas basins in Algeria [14].

Algerians concerned for their water resources have already staged demonstrations and sitins. Their concerns range from water availability to pollution from fracking. Algerians living in areas above shale gas reserves rely on sole source aquifers, that is, aquifers that are their only source of drinking water, so their fears are well justified.

Another country where concerns over water availability (**Figure 7**) for hydrofracking are real and justified is Mexico. Mexico is the eleventh most populous country on earth, with over nearly 125 million people. Mexico has the second largest economy in Latin America after Argentina. Petroleum was discovered in Mexico in the nineteenth century, and production and export began in the 1890s. Petroleum has played a major part in the economy since at least 1980 and currently contributes about 35% of the country's GDP (CIA). It is estimated that Mexico has nearly 600 trillion cubic feet of shale gas, the sixth largest in the world.

Mexico is an arid country with large and growing water shortage issues. The Sonoran Desert and the Chihuahuan Desert are both found in the northern part of the country. The water shortage in 2012 led to failure of pasture land and the starvation of some 350,000 heads of cattle in the northern state of Chihuahua [18].

In some areas development of Mexico's shale gas resource (**Figure 8**) could be limited by water availability, or water already allocated to irrigation and human needs could be in danger of being diverted. Mexico's shale gas is found in the Burgos Basin and Sabinas Basin in the relatively dry north and in the Tampico and Veracruz basins along the Gulf of Mexico (shaded in orange) (**Figure 8**). The Burgos is an extension of the Eagle Ford Formation that has been so successfully developed in Texas (**Figure 8**). The western portion is the La Casita area shown on straddles the Chihuahuan desert.

The Burgos and Sabinas lie below the watershed of the Rio Grande, a river system that drains one-tenth of the US territory and 40% of Mexico. The flow of the Rio Grande is used entirely for irrigation and dries entirely during the summer months [9]. Agriculture in the area is increasingly dependent on groundwater pumping, and fields are being abandoned due to salt buildup. Less than 500 cubic meters of water per person per year is available in the Rio Grande watershed. Clearly, supplying millions of liters of water for each hydrofracked well

Effect of Hydrofracking on Aquifers http://dx.doi.org/10.5772/intechopen.72327 43

South Africa, located on the southern tip of the continent, is the 26th largest country in the world and the 25th most populous one. It is a developing country, with a GDP per capita near the world median [20]. Petroleum production has played little to no role in the county's economy to date. It has been estimated that the Karoo Basin hold as much as 13 trillion cubic feet of shale gas [21]. South Africa is a relatively dry country, with more than half of the country classified as hot desert, cold desert, hot semiarid, or cold semiarid. Demand exceeds reliable yield in 11 of

will have dire water resource consequences.

**Figure 8.** Location of shale gas basins in Mexico [14].

**Figure 7.** Annual precipitation in Mexico [19].

**Figure 8.** Location of shale gas basins in Mexico [14].

Algerians concerned for their water resources have already staged demonstrations and sitins. Their concerns range from water availability to pollution from fracking. Algerians living in areas above shale gas reserves rely on sole source aquifers, that is, aquifers that are their

Another country where concerns over water availability (**Figure 7**) for hydrofracking are real and justified is Mexico. Mexico is the eleventh most populous country on earth, with over nearly 125 million people. Mexico has the second largest economy in Latin America after Argentina. Petroleum was discovered in Mexico in the nineteenth century, and production and export began in the 1890s. Petroleum has played a major part in the economy since at least 1980 and currently contributes about 35% of the country's GDP (CIA). It is estimated that

Mexico is an arid country with large and growing water shortage issues. The Sonoran Desert and the Chihuahuan Desert are both found in the northern part of the country. The water shortage in 2012 led to failure of pasture land and the starvation of some 350,000 heads of

In some areas development of Mexico's shale gas resource (**Figure 8**) could be limited by water availability, or water already allocated to irrigation and human needs could be in danger of being diverted. Mexico's shale gas is found in the Burgos Basin and Sabinas Basin in the relatively dry north and in the Tampico and Veracruz basins along the Gulf of Mexico (shaded in orange) (**Figure 8**). The Burgos is an extension of the Eagle Ford Formation that has been so successfully developed in Texas (**Figure 8**). The western portion is the La Casita area shown on

Mexico has nearly 600 trillion cubic feet of shale gas, the sixth largest in the world.

only source of drinking water, so their fears are well justified.

cattle in the northern state of Chihuahua [18].

straddles the Chihuahuan desert.

42 Aquifers - Matrix and Fluids

**Figure 7.** Annual precipitation in Mexico [19].

The Burgos and Sabinas lie below the watershed of the Rio Grande, a river system that drains one-tenth of the US territory and 40% of Mexico. The flow of the Rio Grande is used entirely for irrigation and dries entirely during the summer months [9]. Agriculture in the area is increasingly dependent on groundwater pumping, and fields are being abandoned due to salt buildup. Less than 500 cubic meters of water per person per year is available in the Rio Grande watershed. Clearly, supplying millions of liters of water for each hydrofracked well will have dire water resource consequences.

South Africa, located on the southern tip of the continent, is the 26th largest country in the world and the 25th most populous one. It is a developing country, with a GDP per capita near the world median [20]. Petroleum production has played little to no role in the county's economy to date. It has been estimated that the Karoo Basin hold as much as 13 trillion cubic feet of shale gas [21].

South Africa is a relatively dry country, with more than half of the country classified as hot desert, cold desert, hot semiarid, or cold semiarid. Demand exceeds reliable yield in 11 of

the country's 19 water management areas. The Orange and Limpopo watersheds cover the areas of potentially recoverable shale gas. These watersheds can supply only 500 to 1000 cubic meters of water per person on an annual basis. Nearly all groundwater in the shale gas areas is already under license for use. The proximity of the shale gas areas to low precipitation

Effect of Hydrofracking on Aquifers http://dx.doi.org/10.5772/intechopen.72327 45

South Africa already struggles to supply water to agriculture, domestic use, and industry. Growing population and an increase in standard of living will continue to increase the growth in demand. Much of the population in areas overlying South Africa's shale gas resources is

Hydraulic fracturing may seem like a simple and straightforward process until one becomes aware of the complex chemistry of the fracking fluid and the necessary complexity based on the number of problems that must be overcome. One way to understand the chemical additives is to consider the problems that must be overcome to fracture thousands of feet of source

The main challenge of hydraulic fracturing is to create deep fractures in solid rock that is confined by the pressure associated with great depth. To accomplish this water is forced at high pressure through perforations in the well pipe. Pressures can be as high as 15,000 psi. In a horizontal well that is thousands of meters long, the fracking process is accomplished in

This process uses vast quantities of water. In the USA it has been found that some wells use as little as 10,000 liters, but more typically wells are using in the range of 1 to 10 million liters, with some wells using more than 35 million liters. More important than the water use itself is the fact that the water use is consumptive, in that most of the water used to hydrofrack a well is lost within the fracked formation. The water that does return to the surface through the

The water is only able to fracture rock if it is delivered at extremely high pressures. Pumps at the surface must not only pressurize the water but also deliver that pressure vertically and then horizontally through thousands of feet of pipe to the portion of the formation being fractured. This involves overcoming the frictional resistance to flow. This could not be accomplished without chemical friction reducers. Currently, organic polymers are most often used,

Hydrofracking generally is used on deep targets, usually at least a kilometer below the ground surface. If hydrofracking was done with water alone, the newly created fractures would

but historically petroleum distillates were the friction reducer of choice.

**6. Aquifers and water resources: hydrofracking's threat to water** 

regions of South Africa can be seen in **Figures 9** and **10**.

fully dependent on groundwater.

rock located thousands of feet underground.

production well is too contaminated to be reused.

**6.2. Problem 2: keeping the fractures open**

**6.1. Problem 1: fracturing the rock**

multiple shorter sections.

**quality**

**Figure 9.** Annual precipitation in South Africa [22].

**Figure 10.** Location of shale gas basins in South Africa [14].

the country's 19 water management areas. The Orange and Limpopo watersheds cover the areas of potentially recoverable shale gas. These watersheds can supply only 500 to 1000 cubic meters of water per person on an annual basis. Nearly all groundwater in the shale gas areas is already under license for use. The proximity of the shale gas areas to low precipitation regions of South Africa can be seen in **Figures 9** and **10**.

South Africa already struggles to supply water to agriculture, domestic use, and industry. Growing population and an increase in standard of living will continue to increase the growth in demand. Much of the population in areas overlying South Africa's shale gas resources is fully dependent on groundwater.
