Approved by the Energy, Environment, and Water Policy Committee on February 20, 2025
Approved by the Public Policy and Practice Committee on May 21, 2025
Adopted by the Board of Direction on July 10, 2025
Policy
The American Society of Civil Engineers (ASCE) recognizes that desalination of saline or brackish waters and seawater can be an alternative source for potable water, especially in areas lacking sufficient and reliable fresh water supplies. In particular, ASCE supports:
- Evaluating the technical, economic, and environmental considerations for desalination consistent with other water supply options.
- Streamlining the permitting process for desalination facilities to condense the overall timeframe and lower the cost of brining desalination plants from concept to operation.
- Promoting research and advancements in desalination technology to optimize process efficiency and energy consumption to provide for the environmentally safe disposal of concentrate (brine), to improve intake systems that better protect marine life, and to effectively incorporate energy recovery devices (ERDs).
- Educating the general public, legislators, and regulators on desalination applications, costs, and benefits.
Issue
The world faces a 40% shortage of fresh water supplies by 2030 (Global Committee on the Economics of Water). With this decline in available fresh water already in evidence, the use of desalination has been increasing throughout the world to produce potable fresh water for domestic, agricultural, and industrial purposes. Currently there are over 16,000 operational desalination plants located in 177 different countries producing 25 billion gallons of fresh water on a daily basis. However, the United States is only home to just over one percent of those installations.
With the growth in global water demand and with shortages already appearing, current fresh water supply sources will become more stressed. Although traditionally more expensive and more energy intensive than conventional water treatment processes, advances in desalination membrane efficiency, optimized pumps, the application of ERDs, and improved back pressure regulation have reduced the energy required for desalination by approximately 40%. Consequently, desalination processes are becoming more economically favorable based upon lifecycle analysis with sustainability principles (such as the use of renewable energy as a power source), it may be more cost effective and attractive to desalinate saline or brackish waters in some areas than to develop or import new supplies of fresh water.
A major concern with any desalination system remains brine disposal, and that has frequently hindered the viability of desalination technology. Regulatory and environmental considerations often preclude the use of common brine disposal options such as surface water discharge, deep well injection, evaporation ponds, and land application. But continuing advancements in Zero Liquid Discharge (ZLD) techniques, both membrane-based and thermal-based, are opening new possibilities for acceptable brine disposal.
Rationale
One of ASCE's ongoing objectives is to promote new methods and technologies that sustain or improve the quality of life. Civil engineers engage in this by developing and implementing effective treatment processes such as desalination. The world's water resources are being depleted by increasing demands. Desalination technologies, including more efficient processes and environmentally responsible brine management, have the potential to enable certain areas to meet growing water demands.
This policy has worldwide application
ASCE Policy Statement 407
First Approved in 1993