University of Washington, Seattle
OP-26: Water Use

UW employs water recovery and reuse system as follows: - Merrill Hall Center for Urban Horticulture’s rainwater cistern captures roof runoff water that is used for landscape irrigation - Gould Hall’s rainwater cistern captures roof runoff water that is used to irrigate a moving green wall. The system includes freeze protection for winter operation, and a fertilizer injection system to support mostly hydroponically grown plants. This was installed by a student-sponsored Campus Sustainability Fund project. - Molecular Engineering roof runoff water is used to irrigate planted cells at grade - Community Design Center’s roof runoff water is used to irrigate planted cells at grade - Husky Union Building parking lot runoff water is used to irrigate a planted cell that also filters impurities - Mercer Hall’s rainwater cistern captures roof runoff water that is used for student laundry washing machines - BB-Tower’s reverse osmosis/deionized (RODI) reject water is captured for reuse as cooling tower makeup water. This was installed by a student-sponsored Campus Sustainability Fund project.

UW employs water metering and management systems as follows: - New and existing central-campus buildings have building-level water meters installed at 27 buildings. All non-central campus buildings supplied directly by the public water utility are installed with building-level main water meters (47 buildings) - Deduct submeters are installed on many irrigation systems, with new replacement deduct meters being installed to comply with updated water utility company requirements - Deduct submeters are installed on cooling towers at the Central Utility Plant. New deduct submeters are being installed at larger building cooling towers during this biennium - On closed loop systems, building meters are installed on all buildings supplied with Central Cooling Water. Main building meters are installed on some research or self-sustaining buildings supplied with steam. Central Cooling Water building meter data is automatically collected at a central database. Steam condensate meter data is automatically collected at a central database for some research buildings, or manually recorded at self-sustaining buildings. The Central Utility Plant's meter maintenance shop periodically calibrate steam condensate meters.

UW employs water-efficient building retrofit practices as follows: - most water closets have been replaced with 1.6 gallon-per-flush fixtures. Some 1.28 gpf fixtures and dual-flush fixtures have been installed during recent building renovations. - most urinals have been replaced with 0.5 gpf or 0.125 gpf fixtures - some lavatory faucets and lab sink faucets have been retrofit with low-flow restrictors - some showers have been retrofit with low-flow showers in residence halls and the Intramural Activities building - sterilizers have been retrofit with Water Mizers to eliminate tempered water consumption during non-sterilizing stages

UW employs water-efficient policies or programs as follows: - Building Utility Renewal program retrofit all central utility plant built-up cooling towers with improved fill material and better drift eliminators that save water - Building Utility Renewal program replaced some factory-assembled cooling towers with new towers that save water through improved heat transfer, accurate water level controllers, better spray nozzles, improved drift eliminators, and calibrated conductivity controllers, - Building Utility Renewal program is installing networked conductivity controllers on some building cooling towers to optimize the towers' cycles of concentration to save water and reduce corrosion - Building Utility Renewal program has replaced many single-pass city-water cooled condensing systems for air conditioning, vacuum or compressed air service with replacement air-cooled or water-cooled systems. - Building Utility Renewal program has replaced most electric or steam pure water stills with reverse osmosis/deionized water (RODI) systems that save water by not needing to temper product water

UW encourages native, drought tolerant, and naturalized plantings. However, even with such plant selection, the local Mediterranean climate typically requires some supplemental irrigation in the summer months and the UW has found this is most efficiently provided via networked, underground, high efficiency, weather informed, automatic irrigation and well-trained staff. Furthermore, UW encourages other cultural practices to minimize supplemental irrigation such as aeration, soil protection during construction, proper soils, soil amendments and soil preparation, mulching, hydrozoning plants with similar water requirements, matching plants with compatible microclimates, annual commissioning and continuous maintenance of irrigation systems for proper function and efficiency, and ongoing upgrades to improve existing irrigation systems and provide new irrigation systems to replace obsolete systems or for areas that were previously manually irrigated. Xeriscaping is often characterized by relatively wide and limited plant spacing, bare gravel and soil buffers in between plants, and point source plant-specific irrigation, often typical in more arid climates. However, in the northwest, design practices include plant spacing at maturity to cover fertile soils to minimize weeds, and accordingly, full irrigation coverage via sprinklers with head-to-head spacing or gridded subsurface drip irrigation is needed to provide efficient irrigation for such mass planting root zones. Nevertheless, the UW champions a local variation of xeriscaping to start new trees. To improve survival and the healthy establishment of new trees, the UW encourages the installation of dedicated point source, tree specific irrigation zones which are operated for two to three years then retired from service. Similarly, as an alternative to plumbed irrigation, short term tree specific irrigation is provided via installing incrementally spaced tubes around new tree root balls and filling them with time release water suspended in a microbe activated cellulose gel. UW has the added challenge of managing some non-native or non-drought tolerant plant and tree specimens to provide a diverse collection in support of several academic and research programs as well as a public tree tour.

UW utilizes a network campus central control system with an integrated weather station to adjust irrigation programs for season changes. Some controllers also utilize standalone rain sensors. In addition to weather sensors, UW also utilizes irrigation submeters and master valves to enhance irrigation monitoring and control, installs high efficiency irrigation such as multi-trajectory, rotating stream sprays, subsurface drip irrigation and pressure regulating automatic control valves. The UW employs a dedicated highly trained irrigation shop and leverages teamwork from other end user stakeholders such as gardeners, plumbers, electricians, information technology specialists, and athletic field groundskeepers. Additionally, the irrigation shop utilizes irrigation record drawings, an irrigation water conservation plan, and is developing GIS supported irrigation asset management. Last, in addition to providing irrigation system lifecycle maintenance, irrigation shop personnel collaborate with construction management, architects, engineers, and contractors to provide existing conditions, design guidelines, and construction support for capital, student, and in-house construction.

UW employs other water conservation and efficiency strategies as follows: - Vehicle washing has been curtailed at Motor Pool - Power washing of buildings and surfaces has been reduced to remove graffiti and slippery material only - Space temperature setpoints adjusted higher in summer have reduced water use by chilled water system cooling towers, and space temperature setpoints adjusted lower in winter have reduced water use by steam heating system - Regular maintenance and innovative repairs on the campus' two swimming pools have solved or averted major water leaks, and closure of a third campus swimming pool has also saved water - Custodians save water using microfiber wet mops in lieu of common string mops, and automatic floor scrubbers are low-water-use - To encourage and champion water conservation, several campus departments communicate green practicies, projects, and achievements to the campus community, including the Environmental Stewardship & Sustainability office and Facilities Services

Additional information about conservation measures can be found here: http://www.washington.edu/facilities/conserve/measures http://f2.washington.edu/ess/