Industries use water in a number of ways. Beverage and food industries use water as a raw material. Factories use water to clean and wash metal surfaces .Heavy mechanical complexes , oil refineries and nuclear reactors use water for cooling purposes.
Research shows that industrial water consumption is a major drain on the world's limited water supply. How do industries stack up in their water usage habits and which are doing the most for conservation?
By 2030, water demand is expected to exceed current supply by 40 percent, according to the Water Resources Group, an arm of the World Bank.
"In many parts of the world, water scarcity is increasing and rates of growth in agricultural production have been slowing," United Nations Secretary-General Ban Ki-moon said in an address to mark World Water Day last month. "At the same time, climate change is exacerbating risk and unpredictability for farmers, especially for poor farmers in low-income countries...These interlinked challenges are increasing competition between communities and countries for scarce water resources, aggravating old security dilemmas, creating new ones and hampering the achievement of the fundamental human rights to food, water and sanitation."
Experts say water shortages aren't solely about a planetary climate that is becoming warmer and drier. Much of the blame can also be laid on the mismanagement of existing water resources.
Many industrial processes use a staggering amount of water from start to finish. It takes about 270 gallons of water to produce $1 worth of sugar; 200 gallons of water to make $1 worth of pet food; and 140 gallons of water to make $1 worth of milk.
A 2010 report titled Direct and Indirect Water Withdrawals for U.S. Industrial Sectors, conducted by civil engineers at Carnegie Mellon University, handily broke down water usage by industry sector, taking into consideration both direct water usage -- which means bringing water into a manufacturing facility for your industrial process -- and indirect water usage -- when a manufacturing facility is buying items from the supply chain that were manufactured by someone else using water, then incorporating those materials into the finished product.
So which industries use the most water? In terms of direct water usage, nobody beats the agriculture and power-generation industries, which together are responsible for 90 percent of direct water withdrawals. Yet a majority of water usage (about 60 percent) is indirect: about 96 percent of industry sectors use more water indirectly than directly in their supply chains.
Fruit & Vegetable Farming
According to the Carnegie Mellon report, while meat farming is often targeted as an energy- and carbon-intensive sector, it shows up lower on the list in terms of water use per dollar of economic output than fruit, grain and vegetable farming. Notoriously thirsty cash crops like wheat, corn, rice, cotton and sugarcane lead the pack in water usage. (A single 5 lb. bag of refined white sugar uses about 88 gallons of water, most of it from the farming of sugar cane and sugar beets.) Better technology and irrigation management would go a long way toward solving some of these problems.
Many farms are investing in technologies for water management, according to a New York Times report last year. These hardware- and software-based solutions use remote sensing data and satellite images to measure factors such as evaporation and yield, identifying areas where water is being used productively and areas where it's being wasted.