March 2008

Lessons in Efficiency

Of the many efforts conducted throughout the US to create “greener” schools, water efficiency is one of the pivotal factors.

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By Carol Brzozowski

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Water usage at the dozen of educational facilities studied ranged from two million gallons to more than 17 million. “We were seeing savings in many of these places in the several to 10 percent range from the audits we were doing,” says Estes-Smargiassi. “We were looking for system-wide gross savings.”

The ICI program also includes a classroom-based educational component. “Our approach is that, in order to have us talk to a class, the school needed to get our material and do work ahead of time. We did teacher training and developed course curriculum, structured around the kind of educational objectives the schools needed to do in order to meet their state certifications,” Estes-Smargiassi says.

“For the younger kids, they were focused on more social problems and some math. For the high school kids, there was science, math, and some environmental lessons. We would train teachers, and do guest lectures in places where teachers had been trained to push the agenda along. But, the core is really getting the educational curriculum out to teachers and equipping them, so that every day when we aren’t there, they might still be using this in all of their classes. We continue that to this day.”

The program serves a dual purpose, he points out. “You get the students from both sides: They save water whether they know it or not, because we’ve got the school district to improve the facility, and then they save water at home, because they tell their parents about it.”

In the infant stages of the ICI program, one of the most inefficient uses of water Estes-Smargiassi saw in the school systems were the multiple showers operated by a single valve. “You’d go into a boys’ locker room and there would be a single valve that would control a dozen showers on a daisy chain around a wall,” he says. “If one kid took a shower, all 12 showers were on, and if the kid didn’t turn off the shower, all 12 continued to run.”

Another water-waster he noted was in high school labs. “In order to get a little bit of suction to run some piece of scientific apparatus, they would have a continuous flow of water and that was hugely wasteful,” he says. “You’d go in some of these schools that were built in 1920 and had 1920 vintage toilets that used nine gallons of water per flush apiece.”

Water inefficiencies in school cafeterias had been rampant as well. “Many of them had been built years earlier, and there were six- to eight-gallon-per-minute spray washes that were set up to be turned on, and left on,” says Estes-Smargiassi. “They did not have a hand control, and weren’t designed with a high pressure head, so you needed six to eight gallons to be flowing in order to be effective.”

Addressing that, merely entailed $25 to $50 retrofits with the spray heads, which saved money within weeks, Estes-Smargiassi says. Part of the challenge in establishing water efficiency measures in schools is that no one had really contemplated water costs, he says. “When you found something in one school, you found it in 10 others. You just had to get someone’s attention at the right level to tell them. In the late 1980s and early 1990s, there was some low-hanging fruit,” he says. “I’m hoping there’s not so much low-hanging fruit anymore.”

Schools Reduce Water Usage
Meanwhile, there are a number of measures schools can take to reduce water use. Tampa’s water department and MWRA recommend a list of measures that educate schools on water-efficient practices. Since domestic water use accounts for some 28% of water use in most schools, leak repair should be a priority in schools. More than 50 gallons of water per day is wasted through a leaking toilet; a dripping faucet or showerhead can waste up to 1,000 gallons per week. Toilet tank water displacement devices such as toilet dams, bags, or weighted bottle helps reduce water use in toilets. Tankless toilets can be retrofitted with diaphragms that save one gallon per flush. Older toilets can be replaced with those that use only 1.6 gallons per flush, realizing an average savings of about 14% of total water use in schools. If replacing a limited number of toilets, start with those located in high-traffic areas.

The options go beyond mere toilet replacement. For example, water-saving aerators or spring-loaded valves can be placed on faucets. In addition, dated gymnasium showerheads can be replaced by models using just two gallons of water per minute. Low-volume faucet aerators can be installed when the entire faucet does not need replacing. 

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Heating and cooling also offer conservation opportunities. A school’s heating and cooling system is the second-largest use of water in schools, accounting for 14% of water consumption. As many cooling towers operate below suggested levels of Total Dissolved Solids (TDS), the boiler and cooling tower blow-down rate can be adjusted to maintain TDS levels at manufacturers’ specifications. Automatic controls and conductivity meters can be installed. Water used in cooling equipment—such as compressors—can be minimized, in accordance with manufacturer's recommendations. Switches and timers can be utilized to match cooling water to the equipment’s duty cycle. 

Ozone is a recommended cooling tower treatment to reduce water used for make-up. Water-cooled air-conditioning units can be shut off when not needed, or replaced with air-cooled units. Metering of make-up water and blow-down can be regularly recorded to address anomalous usage patterns indicating leaks or other system problems. Ensuring that the return of steam condensate to a boiler for reuse also saves water, as well as retrofitting once-through water-cooled refrigeration and air conditioning units, incorporating them into recirculating cooling loops wherever possible. Next Page >

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