Diminishing water baseline levels and increased demand from not only agriculture but also the energy sector has meant that water resources have become constrained. Little data is collected on the availability and consumption of water resources. The U.S. lacks planning in the area of water management and urgent measures need to be taken to appropriately distribute and preserve this valuable natural resource.
Synapse has recently released a report on the water constraints caused by energy production. It explains that thermo-electric power production is the most water-intensive process and is the largest consumer of water in the U.S.
Figure 1: Freshwater withdrawals in the United States
Water consumption in energy sectors
Power plants end up withdrawing between approximately 141 billion to 200 billion gallons of water per day for the purpose of cooling and emissions removal. “On an average day, water withdrawals across the nation amount to an estimated 85 billion gallons for coal plants, 45 billion gallons for nuclear plants, and 7 billion gallons for natural gas plants. Significant amounts of water are also required for fossil fuel extraction, refining and processing, and transportation. Coal mining consumes between 70 million and 260 million gallons of water per day, and natural gas fracking requires between 2 and 6 million gallons of water per well for injection purposes,” reports Synapse.
While these demands on the limited resources continue to grow with the growth in population, the pool of fresh water sources grows smaller. Much of the water withdrawn for power production is returned after being used for cooling purposes but about 3 percent is consumed or evaporates in the process. Furthermore, the water returned to the reservoirs may be contaminated or it may be heated to a temperature where it is dangerous to marine life.
Among the different sources of thermoelectric power, coal and nuclear are the largest consumers of water. Coal withdraws 60 percent while nuclear takes 32 percent of total water withdrawals for thermo-electric use.
Figure 2: Estimated water withdrawals for electricity generation in the United States
Coal and nuclear require more water at the power production phase but natural gas production involves a fracking process that involves intensive use of water. The process of hydraulic fracking is relatively new and is exempt from all water-related laws, says Frank Ackerman, one of the authors of the report. He says that approximately 0.6 to 1.8 gallons of water per mmbtu is used for the process of fracking while the estimated water consumed in the drilling and fracking process ranges between 2 million to 5.6 million gallons per well. Furthermore, chemicals used in the process can contaminate the water which is discharged into reservoirs after use.
Melissa Whited, co-author of the report released by Synapse, explained that infrastructural upgrades are required to make the energy production process cleaner and to return sanitary and safe water to reservoirs after is has been used by energy companies. Most energy and public utility companies enjoy economic and political influence and can easily dodge water usage and reporting laws.
Increase in demand of energy and resources
‘The large proportion of water used by power plants is increasingly problematic, considering that the national population is expected to grow rapidly over the coming decades, rising by more than 100 million by 2060. Electricity demand will continue to increase, driven by a combination of a growing population, larger incomes, and migration to warmer regions with higher cooling requirements,’ says Synapse.
Thus, it is important to install an effective water management system and allocate budget for water research. The energy sector must be forced to comply with state and federal regulations regarding water withdrawal, use and discharge so as to ensure availability of safe water for population.