Commercial brewers use, on average, 5.1 barrels of water to produce one barrel of beer. This amount does not include the water required to irrigate the hops and grains or to clean the brew kettles.

I acquired this knowledge last month when I attended the Green Manufacturing Summit sponsored by Bradley Corp. in Milwaukee. “With beer being 98% water, brewers were paying attention to how much they use before the green movement started,” said keynoter Kim Marotta of MillerCoors. She called the scarcity of water one of the biggest threats facing the food-and-beverage industry.

MillerCoors uses 4.1 barrels of water to brew a barrel (1 hectoliter) of beer, Marotta said. The United Nations Environment Program’s benchmark is a 5:1 water-to-beer ratio.

An offshore brewer has achieved the industry’s best ratio of 3.2:1. Anheuser-Busch's ratio, she noted, is 5.5:1. As vice president, corporate social responsibility, Marotta’s primary interest is drunk driving. Next comes the environment, where she focuses on reducing MillerCoors’ water footprint, using water more efficiently and overseeing wastewater management.

While plumbing and mechanical engineers undoubtedly play an important role in MillerCoors’ conservation efforts, the glimpse inside the brewing industry reminded me of how many of us look at only a portion of what is a very large problem. The work to reduce water usage in plumbing products, for example, is essential although pursued in isolation from water conservation efforts in other industries.

A similar point occurred to me a couple weeks earlier when I attended a meeting of IAPMO’s Green Technical Committee in Chicago. A committee member expressed frustration over how a homeowner one day might have to install a shower with a single low-flow showerhead in the same house with a fountain in the driveway and swimming pool in the backyard.

The committee is developing a supplement to the current codes that will provide guidance to IAPMO members on matters related to sustainable construction. In the meetings I’ve attended, no subject has sparked more controversy than whether multi-head showers should be included in IAPMO’s green supplement.

Another member responded to his colleague’s frustration by saying the committee must concentrate on what it can do to save water inside the building. “We cannot concentrate on what other people can do to save water,” he said.

True enough, although cooperation, awareness and communication couldn’t hurt. Back in Milwaukee, a breakout session on manufacturing in a lean and green economy followed the beer keynote. Speaker Joe Jacobsen, an associate dean of environmental studies at Milwaukee Area Technical College, ended with this plea:

“We must move toward a system of cooperation of users of resources – people in the same industries and in different industries using the same resources, and people in different nations using the same resources.” We usually talk about the problem of wasting water in the big picture in terms of billions of gallons. We must keep the big picture in mind for solutions, too.