Because the U.S. has relatively abundant water resources, most people don't associate extracting natural gas and power generation with water use. However, the energy industry relies heavily on water to extract natural gas from shale formations and to cool power plants. For example, fracking a single natural gas well in Texas generally takes 3-4 million gallons of water. In very tight shale formations in Texas, 13 million gallons of water, enough to supply the cooking, washing and drinking needs of 240 adults for an entire year, are required.
Extremes temperatures this past summer in Texas serve to remind us of these fa<?xml:namespace prefix = st1 />cts. Call it the effects of global warming or whatever you like, but it has been hot and we have seen all sorts of extreme weather in the U.S. Texas is a good example of this.
Texas just experienced the warmest summer (June-August) on record of any state and its driest summer and 12-month period on record. One critical result has been the decline of water reservoirs, which in the Dallas-Ft. Worth area (home to the Barnett Shale) has led to restrictions on water use for hydraulic fracturing that is used to extract natural gas from the shale. The use of water to extract the natural gas is called fracking.
Cities in this area have the power to declare water-use restrictions, although all have agreed on three stage levels at 75%, 60% and 45% of normal. Recently, Grand Prairie officials declared a stage 2 (60%) restriction, which limits water use in industrial and construction operations and prohibits use of water for gas-well operations (this does not include recycled fracking water).
Apache Corporation a natural gas company curtailed some fracking operations because of the lack of fresh water. There are variances, or exemptions, however, and several of these have been granted.
- Stage 1, when reservoir levels fall to 75% of normal, requires limitations on outdoor water use (watering lawns; hosing sidewalks, driveways or structures; and washing cars); this is the restriction that now applies in Arlington, Texas.
- Stage 3 (45% of normal) requires that all industrial-construction water usage be cut on a pro rata basis (no variance). Officials said that 50%-60% of all water is used for outdoor water usage, while natural gas drilling and fracturing accounts for 1%.
We're not talking just a trickle of water here either according to a cited source by Bloomberg News:
"The Eagle Ford’s peculiar geology means it takes three to four times as much water to fracture as the Barnett Shale near Fort Worth, said Mace, of the state water board. Fracking a single Eagle Ford well requires as much as 13 million gallons of water, enough to supply the cooking, washing and drinking needs of 240 adults for an entire year, he said. "
Read the Bloomberg article on fracking.
Factoids on Water Use in the Energy Sector
Water has been termed the archilles heel of the nuclear power industry because without massive amounts of water to cool the reactors the plants have to throttle their output down. The same can be said of other fossil fuel power plants.
- Overall the U.S withdraws approximately 410 billion gallons of water per day (fresh and saline) from surface and groundwater sources.
- The thermoelectric generating industry is the largest withdrawal user. That includes coal-fired, natural gas- fired and nuclear power plants.
- 70 % of the thermoelectric withdrawal use is from fresh surface water sources and the remaining 30% is almost all from saline water sources.
- Droughts can restrict fossil fuel and nuclear power plant operations. For example, lower reservoir and river levels can reduce the water necessary to nuclear power plants and in some cases limits their operations. France has embraced nuclear power. However 37 out of France's 58 nukes are situated on rivers and the country has realized just how vulnerable those plants are under drought conditions. The same goes for the U.S. In 2008 a drought in the Southeastern U.S. started to adversely affect nuclear power opearatios as lake and river levels deciined.