Water Consumption: The Next Big Industrial Cost

North Americans are the largest users of water, sending about 1,800 gallons per person per day down the drain. This figure represents not only personal use but the water required to manufacture products and food. Agricultural and industry use about 50 percent of the water consumed in the U.S., with the five most water-intensive non-agricultural or non-power generation industries being forest products, steel, petroleum, chemicals, and food processing.

As the Earth’s population continues to climb, along with demand for consumer products and energy, so too does water use. According to a UN report, fresh water withdrawals have tripled over the last 50 years, and demand for fresh water is increasing by 64 billion cubic meters a year. By some reckoning, it may be nearly impossible to provide enough water to a world population forecast to reach nine billion by 2050.

As manufacturers consume more water to produce more goods and services, their overhead for water usage also rises. Some nations and even individual U.S. states facing chronic water shortages are ensuring that manufacturing organizations are paying steeply for both the fresh water they use and the spent water they discharge. In addition, new environmental effluent standards and regulations are driving up water costs.

In short, many companies are finding that it’s simply no longer feasible to waste water. National and regional governments are metering water more closely, and many have begun to provide incentives for more efficient water use, which is leading some companies to add water conservation to their sustainability programs.

Water is used in a number of ways during manufacturing processes, much of it to cool down machinery and equipment, as well as cleaning and rinsing, steam generation, and heating and facilities maintenance. Water conservation groups say there is room in every step of the manufacturing process for improvement, whether by changing or modifying machinery to use less water, switching to waterless processes, or treating and reusing water. It’s a daunting prospect, and should begin with a comprehensive review and planning strategy.

Keep track of water usage. Many manufacturers today don’t track their water consumption, which should be the first step of reducing its use. Companies can begin by implementing a water auditing system that reviews the life cycle of water in the plant from intake to discharge. An audit should track not only primary uses, but also secondary uses, such as wash water, irrigation water for landscaping, and water used in restroom facilities. It should include where the water is used, what quality it needs to be, and where savings opportunities might exist. This can be accomplished by sub-metering of water, or breaking out each water-using process and measuring precisely how much is used.

Build a water management strategy. Once a company knows how much water it uses, it can begin to set specific targets for reduction and plan how to achieve them. This strategy should be reviewed at least once a year to ensure that it accommodates changing business needs.

Determine the areas where waste water can be recaptured and reused. Chances are, not every water-based process requires fresh water: so-called “gray water” will do just as well for the purposes of cooling, rinsing, boiling, or flushing. There are benefits to such a switch beyond cutting water use. By reducing water discharge, companies may be able to minimize regulatory and discharge fees.

Recover waste heat instead of dousing it with water. One of the most common uses of water in manufacturing is for cooling hot machinery. Conversely, one of the easiest ways to reduce energy consumption is to recover waste heat and use it to heat the facility. Moving to a waste heat capture (or “cogeneration”) system can reduce both water usage and energy costs.

Invest in on-site water treatment. Rather than discharging used water and pulling fresh water from municipal systems, many companies have turned to treating wastewater on site to prepare it for re-use, in some cases using relatively inexpensive carbon filtration.

Recover water from steam boilers. Another common use of water in manufacturing is for boilers to generate steam. There is great potential for water loss here as the water turns to vapor and escapes the system. Many eco-minded companies are recapturing steam in heat exchangers designed to collect the condensate and return the water to the boiler.

Water management is not just about conservation. It’s about company image, too. Facilities in water-scarce areas that use too much water will see their reputations suffer, and if the outcry is loud enough – particularly in the case of foreign companies operating in developing regions – overuse of water may tempt local officials to shut off the tap or tack on outrageous surcharges. Whatever the motivation for water conservation, it’s clear that it’s time for manufacturers to begin to sip instead of gulp.