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Over the past several years, growing demand for water-saving technology has produced a wave of advances in plumbing fixtures. While these products have created water-saving opportunities, they also have made the specification process more challenging for maintenance and engineering managers to determine which ones offer the best efficiency.
Due to rising utility costs, managers with Stanford University in Stanford, Cal., have made water conservation a top priority in the last six years, focusing on fixtures that not only save water but also meet the needs of occupants.
Their progress has been impressive. In 2001, the university used about 2.7 million gallons of domestic water daily. In 2006, its average daily use had dropped to about 2.2 million gallons a day. A significant amount of that reduction resulted from more than $2 million worth of retrofits, including the installation of low-flow fixtures throughout the campus’ 670 major buildings, which incorporate about 13 million square feet.
Some of the biggest efforts have been in the student housing facilities. Retrofits in these facilities: replaced more than 2,300 shower heads delivering 5 gallons per minute (gpm) with 2 gpm models; replaced 2,200 toilets used 3-4 gallons per flush (gpf) with 1.6 gpf models; and installed 4,500 sink aerators that cut water flow to 1.5 gpm.
The key to success for the university’s efforts has been rigorous testing of numerous plumbing technologies in different areas, says Marty Laporte, the university’s manager of water resources and environmental quality.
“Doing pilots of technologies and getting students to help with those pilots I think is a good piece of advice,” says Alicia Restrepo, Stanford’s assistant director for planned and sustainability programs in student housing.
Trial and Error
With so many technologies available, managers might want to focus their initial research on one type of plumbing fixture. For example, last year Laporte started a demonstration program in the campus’ utility department that focused on high-efficiency toilets that use an average of 1.28 gpf or less.
“High-efficiency toilets have been around for a number of years, and there have been studies about toilet efficiency and how well they work,” Laporte says. “So I thought, no problem. We’ll just buy a couple of toilets and recommend them to our housing staff. I found out that not all high-efficiency toilets are created equal, and there are still a lot of user problems.”
For example, the instructions for dual-flush models confused some users, she says. On some models, a user needs to move the handle up for a low-flow flush. If the units have a non-standard type of handle and the instructions were unclear, many users didn’t know how to properly flush it. As a result, the units weren’t producing the water savings managers wanted.
“Furthermore, some of these toilets really don’t work,” she says, adding that users felt the need to flush the unit three times to dispose of all waste. “It is completely counterproductive.
“Once I started testing them, I couldn’t believe the difference between different toilets. Even the ones that were highly recommended on various web sites weren’t necessarily as user friendly and as efficient as people might think.” Laporte’s department evaluated about a dozen toilets and used the results to help create a guide to water-efficiency goals for new buildings and retrofits.
Fitting the Application
Using guidelines for plumbing fixtures’ water use and performance gives managers important data to use in choosing the most appropriate fixtures for specific applications.
“I think people really need to test out technology to make sure it fits their application,” Laporte says. “The product could get the most raving reviews from third parties. But if you have different groups of users, you might discover that one type of technology might not fit all of those uses.”
Adds Restrepo, “We might end up with different models in the academic buildings than in residence halls.” Restrooms in some of the academic buildings often are used less than those in dorms. So it is important to test fixtures for the different uses before making final plans for the project. The performance of waterless urinals in university buildings also was affected by the level of traffic.
”We tried waterless urinals at two different locations,” Laporte says. “In one location they’re working perfectly. In that location, they have very low use, and a local maintenance person maintains close supervision of the restrooms.”
The university also installed four waterless units in a facility with higher traffic levels — about 100 people every day. In that building, odor problems arose, and the waterless urinals became a maintenance headache, Laporte says.
“They had to be maintained constantly. So we decided a better solution was to have urinals in that area that flushed and used an eighth of a gallon of water.
“I would consider waterless urinals again, but not on a large scale. The technology has got to get better.” Laporte also learned that pressure-assisted toilets can create too much noise for some office areas.
“This technology might be okay in some offices, but we tried them in a small building with thin walls and cubicles, and it didn’t work well for us at all,” she says. People in adjacent offices could hear every flush.
“We tried a whole host of pressure-assist units made by various manufacturers, and they were just too loud and too disruptive, and everybody complained,” she says. Guidelines for specifying fixtures also are important because technology is evolving rapidly. Laporte says her high-efficiency-toilet test program will continue as manufacturers unveil new models.
“I’m waiting on some new technology for (manual) flushometer toilets that will allow a high-efficiency flush of less than 1.28 gpf,” she says. “That technology is not yet out on the market but should be available at least for testing this summer from several manufacturers.”
Roadblocks to Efficiency
Stanford’s testing also has revealed performance problems with some low-flow fixtures.
“We’re seeing an increase in the incidents of sewer lines plugging,” says Larry Hoffman, manager of building renewal and utilities.
With less water flowing through pipes, it is more likely that waste will get stuck in the smaller branch lines, he says. Eliminating the use of liquid soaps might prevent some blockages.
“They accumulate and sit in the pipes, where they get hard like concrete and can block the pipes,” Restrepo says. “We’re seeing more reports on a daily basis of clogged drains, and we’re seeing (liquid soap) as a potential cause of the problem. So we’re considering switching to foam soaps because you use a lot less soap, and it goes down the drain better.”
In general, occupant behavior might be the biggest challenge managers face in implementing water-saving plumbing technology that deliver long-term results.
“A lot of people like to think that they’re sustainability minded, but it is very difficult to modify people’s behavior for the long term,” Laporte says. “People tend to be very sympathetic to water conservation during droughts and emergencies, but to sustain conservation and water efficiency for the long run can be difficult.”
Dual-flush toilets, which leave the water-use decision up to the user, also can present challenges for organizations looking to reduce water use. Some users might always push the handle down and flush 1.6 gpf, which is a standard flush, rather than push it up to flush using 1.28 gpf or 1.1 gpf.
Successful water conservation doesn’t end with the installation of new fixtures. It requires constant re-evaluation and monitoring of products and their use to determine whether they’re delivering benefits.
“We track our monthly average daily use,” Laporte says. “We have about 1,600 meters, and it takes three days to read all of the meters by several people. Some of our meters are on automatic radio read, which means workers can walk by with a wand, and the meter reading registers in a computer. But some meters are manual, so somebody has to look at it and enter in the data.” Laporte emphasizes the importance of watching for and addressing any sudden changes in water use.
“If water consumption in a particular building goes up, my question is, ‘What has changed in that building?’” she says. “Many things could have changed, such as the type of research occupants are conducting in that building.
“To track down all of this information is very difficult. You really need to have a network of people who understand the facilities and are willing to pay attention.”