Conserving Water for a Thirsty Planet

Conserving water by using low-flow fixtures and low-impact stormwater design requires system thinking and integrative design.

Celeste Allen Novak AIA, LEED AP

The planet is getting thirsty as fresh water resources are being used by an ever-growing population. According to the EPA, the water deficit is currently estimated at about 3,700 billion gallons. In fact, we are using more water than nature is providing through rain and snow and condensation. The hydrologic cycle is elemental to human life, however, most diagrams of this cycle don't really show the impact on water quality from buildings, homes and impervious surfaces. In the United States alone, approximately 340 billion gallons of fresh water is withdrawn per day¹ to support residential, commercial, industrial, agricultural and recreational activities.

Domestic water use in the U.S. is approximately 43 billion gallons per day, drawn from both public and private systems. As fresh water becomes waste water, it is discharged back into the ecosystem, often without treatment, or with diminished water quality. Increased use of water for agriculture and irrigation systems adds to the water deficit. Humans are now drawing deeply into the aquifers of natural water storage systems. Gunnar Baldwin, water specialist for TOTO USA, dreams of a future that takes the "waste stream and turns it into a resource." Energy from methane - waste nutrients for fertilizer and water - filtered for re-use, may be the answer for the planet's fresh water crisis.

Water is one of many building systems requiring design integration. From outdoor irrigation to indoor water use, stormwater to wastewater, new construction to the rehabilitation of existing buildings, designers who understand the impact of water use on site sustainability, can reduce potable water use significantly. According to Mike Baron of The Toro Company, when you don't pay attention to all of the factors in low-impact design strategies for irrigation, "your site can produce unnecessary run-off which carries nitrates, pesticides and waste residue into municipal storm drain systems causing harmful pollution." In addition to water saving equipment outside and inside buildings, moisture proofing is another way to manage water flow.

 Design integration which includes water saving equipment, and low impact design practices can mitigate the impact of buildings on water use and water quality. There are two main goals a designer can consider to integrate water as a design system. The first is to decrease the demand for water and the second is to find ways to re-use water in both internal and external applications.

Construction crew installs new reinforced liner and containment chambers under forecourt of Monterey House. Photo courtesy of BTL Liners, Inc.

 

University of Washington

University of Washington retrofitted their plumbing to save water, conserve energy and be "green." Photo courtesy of Zurn Engineered Water Solutions Environmentally conscious University of Washington is located on a fresh water lake in Seattle that had problems with alge bloom from residential sewage run-off.  The city of Seattle, like many cities with overburdened treatment centers, encouraged the University to reduce water use on campus. As an incentive, the city offered a rebate of $120 per water fixture that the university replace with new water saving equipment.  The bathroom retrofit project started with a focus on urinals.  The University utilized a multi-story dormitory on campus as a laboratory for testing purposes and installed different systems including waterless urinals. They installed sensors in the wall to calculate the water use at each fixtue and the life expectancy of cartridges in waterless systems.  After six months, they decided that an engineered 1/8th-gallon system was the fixture that met their needs and installed these urinals throughout the University to replace the 3.5 gallons per flush urinals. In partnership with the manufacturer, a urinal was designed that both worked within small installation areas and had a pressure compensating valve so that it could be fit onto existing plumbing lines.  This flush valve is controlled by a solenoid to deliver a precise amount of water no matter how much water pressure is in the older system.  By smart engineering, the University saved both water and the potential cost of costly asbestos abatement as they retrofitted their older buildings. According to Bryan Murdach, a manufacturer's representative from Mechanical Agents, Inc., "This small urinal enabled the university to easily retrofit the older fixtures without disturbing the waste line, the water inlet, or most importantly, the wall itself."

DECREASE THE DEMAND

According to the American Water Works Association, average daily water use in a single family home is approximately 69.3 gallons. Americans use water through a variety of home appliances and fixtures and lose a surprisingly 13.7 percent of water from leaks.²

Sean Martin, VP of Marketing and Sales for Zurn Engineered Water Solutions, stated that when beginning a water management program, "Designers need to understand who is going to occupy a building and what their needs are in order to benchmark technologies and decide which technology fit the occupants the best." He recommends that in most commercial settings and renovations, it is best to educate the users through smaller modifications which then can become standard retrofits as users accept new equipment such as high efficiency toilets, faucets and urinals.

STORMWATER, IRRIGATION AND WASTE WATER

Highly efficient sprinklers have an effective application rate and provide uniform coverage to maintain this turf grass while minimizing water waste. Photo courtesy of The Toro Company

 

Businesses, industry and agriculture draw from water resources both from public and private sources. Irrigation accounts for a large portion of water use by businesses, and often is billed as waste water, when it is supplied by a public facility. Wasting water is expensive and costly to the preservation of this important resource. Both at home and work, water management begins with by educating the users and setting water budget that targets water management goals, both inside and outside.

Water management also includes the control of water infiltration and storage for re-use. New geotech fabrics provide linings for pools, waste treatment and irrigation systems. Environmentally friendly crystalline chemicals are available to protect concrete foundations and increase the durability of water containment systems.

Ground conditions and water access varies by region. In some cases, water use is carefully metered and high infrastructure fees are attached to new construction and new tap-ins to water and sewage systems. The price of water runs from the pennies per gallon from a municipal water supply to over $5 per gallon when buying water by the case. Most communities capture the cost of the infrastructure required for water management development fees by charging for new attachments to the municipal water and waste supply systems. These costs have escalated in the past years as aging infrastructure demands that cities put more tax dollars into water treatment systems. In some cases, the rivers, lakes and streams have reached capacity for treatment and new technology is required to meet the development pressures.

Crystalline coatings can be applied to repair water damage on concrete water containment systems. Photo courtesy of Xypex Chemical Corporation

 

Water that comes from a public water supply is metered. Private systems or wells which supply water appear to have an unlimited supply of this resource until the well runs dry and requires deeper drilling into new aquifer supplies. When designing a large commercial water system, designers can provide separate meters for irrigation and cooling tower water. This water does not return to the waste stream. In fact, some professionals have been able to negotiate with a municipality for reduces fees for this water as it does not return to the municipal treatement systems. Separating irrigation water from building water is one method of system design to save water.

Low-impact designers know the importance of effective water management. In many parts of the country, outdoor irrigation water use accounts for a large portion of the water budget for buildings. Today, advanced technology has produced a full line of irrigation products that can assist the designer in reducing outdoor water use by 50 percent, conserving water through lower flow, higher efficiency sprinklers and sub-surface drip irrigation systems.

There are two main factors that determine sprinkler efficiency. Whether watering turf grass or landscape, the irrigation system should deliver water at a low but effective application rate - a measure of how fast water is applied - as well as with a high uniformity of distribution -how evenly the water is applied. Combined with correct irrigation scheduling, these low application rate, high uniformity systems prevent run-off while applying enough water to maintain the landscaping while minimizing water waste.

Dripline or in-line tubing is flexible, polyethylene tubing with pre-installed, pressure compensating emitters featuring specific flow rates (1/2 GPH or 1 GPH) and specific spacing between the emitters (12", 18" or 24"). It is available in 1/4", 1/2" and 5/8" diameters, and is ideal for narrow planting areas less than 8 feet in width. This is because dripline tubing delivers water at or near the root zone of the plant material, virtually eliminating unwanted evaporation and overspray typical of conventional spray systems. In addition, the soil type determines which spacing or flow rate is best for a specific application.

Dripline irrigation systems can achieve an 85 to 95 percent water-use efficiency compared to about 50 percent efficiency for conventional spray head systems. Some dripline systems are even designed for sub-surface installation because they provide protection against root intrusion. By irrigating underground, there is no water lost to evaporation. Design professionals who wish to reduce outdoor irrigation water use by as much as 50 percent can use high−efficiency sprinklers and dripline irrigation systems to achieve their goals.

Subsurface irrigation systems are installed to reduce evaporation and can be integrated into active turf lawn areas. Image courtesy of The Toro Company

 

Waste water is sent to municipal treatment centers or is processed through individual or group septic systems. Some designers have experimented with building "living machines" initially developed by bioligist, Dr. John Todd. These ecological systems provide an organic purification system for buildings. At the Adam Joseph Lewis Center for Environmental Studies, watewater is sfiltered in a greenhouse and tested by students to verify that the system meets effluent standards. Examples like this are beginning to change the concept of waste water discharge in buildings.

Primarily in the West, irrigation water is drawn from municipal sewage water that is treated to an appropriate level for plants, but not necessarily for drinking water. This provides water to irrigate golf courses and recreation complexes.

Pronghorn Club Resort in Bend, Oregon

View from the 13th hole of Pronghorn Lake after and during construction. Photos courtesy of BTL Liners, Inc. In 2003, the Pronghorn Club Resort in the city of Bend, Oregon installed a manmade lake lined with a reinforced heat welded geomembrane used to contain the cities overflow waste water. This decorative lake was designed to contain treated wastewater which was then used for irrigation on the resorts two golf courses. An alternate method of water storage and use, these environmental liners and geo tech fabrics are substitutes for concrete, steel and bentonite liners used in infiltration, storage systems and cisterns. According to Ron MacKenzie at BTL Liners, Inc., "The world is starting to get smarter in its use and re-use of water."

 

NEW TECHNOLOGIES FOR OLD PLUMBING FIXTURES

In 1992, the EPA launched the ENERGY STAR program to help consumers identify energy efficient equipment. WaterSense is an EPA partnership program providing education, resources and case studies of plumbing fixtures and equipment. The EPA WaterSense label means that the products have been tested and certified by an independent third- party to meet EPA criteria for water efficiency and performance.

WaterSense also is an organization that develops new standards for water efficient products. Most current standards are based on the Energy Policy Act (EPAct) of 1992 that mandated the use of new plumbing fixtures and fittings to reduce water use in buildings.

The maintenance of water equipment and the training of occupants to use water wisely is an important piece of any water system. According to the EPA, leaky faucets that drip at the rate of one drip per second can waste more than 3,000 gallons of water each year,³ leaking toilets account for even larger amounts of waste. There are many water calculators on the Internet which provide instructions as to how to choose efficient water fixtures and detect leaks to calculate and measure water use.

Gunnar Baldwin, LEED AP, Water Efficiency Specialist at TOTO USA, consults as a member of one of the U.S. Green Building Council's technical advising committees and is a director for the new organization, The Alliance for Water Efficiency.⁴ This organization is a voice and a platform for water efficiency which hosts a web clearinghouse on water conservation research and regulations.The Watersmart Guidebook, published by the East Bay Municipal Utility District,⁵ is an example of the many documents collected on this inclusive website. In the early seventies, Baldwin said that he was part of the "lunatic fringe," but today his vision of the 1.6 gallon flush toilet is now the EPA standard and he is now "swimming mid- stream with the flow."

High-Efficiency Toilets

Waste water accounts for the largest water use in homes, and engineers have focused on how to make toilets and urinals use less water.

High-end bathrooms can have high-efficiency toilets, faucets and showers. Photo courtesy of TOTO USA

 

The first water closets, or toilets, were patented by Alexander Cummings in 1775 with an "S" trap that is still used today. The first public toilets were exhibited at the Crystal Palace in 1851. This world exhibition showcased the future and indoor plumbing was a promise quickly embraced by growing industrial nations. Low consumption toilets were already in use on trains and yachts as early as 1968. By the 1970's, the new environmental movements in Europe and the United States challenged inventors to find new means to reduce the flushing mechanism of toilets. It was not the lack of water driving this innovation, but the excess of water in the waste stream, as there had been systematic failures of septic systems, as well as municipal sewage treatment failures in large cities such as Boston. Most flush toilets used between 5 and 8 gallons of drinking water per flush before new standards were enacted.

In 1992, The Energy Policy Act (EPACT) required manufacturers to apply a 1.6 gpf standard to all new toilets as predicted by Gunnar Baldwin. As the new toilets were installed into older buildings, some problems began to surface. Plumbers found they needed to calculate the slope of the existing plumbing lines and in some cases, the size of the waste line. The first versions of these toilets were often manufactured or tested by two entities and in many cases the flush mechanism did not work well within the fixture design.

According to Gunnar Baldwin, the first real breakthrough, since the toilet was invented, occurred in the 1990's when "the first bowls were designed by computer modeling, which optimized the hydraulic capacity." Some of the new technologies included new trapways, an increased flow rate from the tank to the bowl and an understanding of the frictional coefficient of the walls of the bowls. In addition, new certification testing was required by WaterSense and the EPA.

Building rating systems soon required even higher water performance from waste fixtures. For example, LEED® the USGBC rating system for Homes requires that all toilets exceed the EPACT baseline by 20 percent or more. A major tool for the reduction of potable water, HET's or High-efficiency Toilets should:

• Flush at 1.28 gpf or less.
• Meet the EPA WaterSense Label
• Certified by a third party testing agency
• Require minimal cleaning with enironmentally unfriendly detergents
• Flush quietly
• Meet universal design standards

The Maximum Performance (MaP) Testing program was developed in Canada to provide a standard for toilet performance. This test reviews the grade of the toilet flap as well as the combination of fixture to flushing mechanism as a whole system. MaP tests also involve the use of real fecal waste and are the standard for good toilet performance.

This high-efficiency toilet flushes at 1.28 gallons per flush (gpf). Photo courtesy of TOTO USA

 

There are composting toilets, and dual-flush toilets. Water specialists are quick to remind professionals that volume is measured as a multiple of rate X time. Toilets can still save water by reducing the length of time the water flushes at a larger volume. The advantage of a dual flush toilet is that it allows the user to select a lower flush volume for liquids versus a larger flush volume for waste. In the future, toilets may flush using a vaccum to go below one gallon per flush, however, plumbers may need to design periodic flush rinses to clear lines. New pressure assisted toilets also use less water, but are currently a noisy option. Another new water saving water closet has been designed primarily for use in assisted living facilities. This unit reduces the use of toilet paper as well as water, combining a full seat wash with a drying element using electronic components. Some new fixtures have advanced glazes which provide micro-bacterial resistance and increase the removal of effluent with less water wash.

Gunnar Baldwin notes, too, that "recycling toilets are already occuring in China, Northern Europe and India that will separate solids from liquids, and store the liquids long enough so that they become sterile for agriculture as fertilizer."

Urinals

This new urinal is engineered to use only 16 ounces of water per flush and is designed with pressure-compensating valves, making it ideal for retrofits. Photo courtesy of Zurn Engineered Water Solutions

At the University of Nebraska, College of Architecture, the Hinsdale urinal is celebrated in a yearly ceremony at Halloween time. Patented by Winfield E. Hinsdale on November 1, 1901, these urinals were installed in the 1890's and relocated in 1985 when the Architecture School was renovated. According to AIAS students, these urinals, decorated with inscriptions are some of the largest urinals west of the Mississippi.⁶ Early urinals like the Hinsdale were not water savers.

Sean Martin believes that the "silver bullet" to eliminating a large amount of water waste, particularly in a commercial setting, is low flow urinals- specifically the latest 1-pint per flush consumption urinals. These low consumption urinals provide 88 percent water reduction per flush vs. the EPA baseline of 1.0 gpf. A lot of attention has been paid to urinal design. Many professionals initially embraced the waterless urinal technology to meet LEED® standards, only to find that there have been problems with consumer acceptance and maintenance. The EPA is currently developing a new low flow urinal standard expected release later this year.

According to the EPA, nearly 80 percent of the urinals in use today, approximately 9.6 million fixtures, currently exceed the maximum allowable flush volume set by federal standards. Replacing these fixtures can save between 1 and 4.5 gallons per flush (gpf). New high-efficiency flushing urinals fixtures and flushometer valves bearing the WaterSense label will use no more than 0.5 gpf at least 50 percent less water than standard flushing urinals.⁷

The new standard is expected to test for trap seal restoration, flush effectiveness and will replace the current standard of 1.5 gpf of most urinals. Some of the problems with low flush or waterless urinals such as line calcification may need to be resolved by allowing for periodic flush rinses or trap exchanges. Although a common maintenance practice, it is not necessarily a good environmental option to use an acid wash to clear low flow or waterless urinals of bacteria.

 

Faucets and Showers

Cut-away of a faucet that uses a water turbine. Photo courtesy of TOTO USA

Medical professionals and mothers agree, hand washing is the best way to avoid illness. New water faucets make good hygiene easier and some energy efficient faucets appear to supply an endless supply of water for washing while limiting water waste. Water faucets which do not supply enough power to rinse soap are not a good choice for water saving. Studies show that if a low flow fixture does not deliver enough water to the consumer, then it is often tampered with, aerators are removed or the water use is increased as the consumer attempts to accommodate the lack of rinse capability.

The LEED 2009 V3 utilizes the EPA's 1992 regulations as baseline for faucet aerators in private applications (hotel or motel guest rooms, hospital patient rooms) at 2.2 gallons per minute (gpm) at 60 psi. All other applications will use a baseline 0.5 (gpm) at 60 psi. "The baseline for metering faucets is 0.25 gallons per cycle. Water conserving 0.5 gpm aerators squeeze water into a pressurized spray," says Sean Martin, "so that users cannot tell a significant difference in water consumption." Touchless faucet sensors can be operated by electric eyes, infrared sensors, proximity detectors or motion sensors and their batteries can be powered by solar cells. The latest smart technology uses the water itself as a source of power. This water turbine regenerates the battery as the faucet is used providing almost energy free battery power to the units.

Residential consumers often are not happy with slower rates of water, particularly when washing dishes. For now, kitchen faucets may need to be at the higher flow rate of 2.5 gpm, and to compensate, new sensors will regulate water flow as needed.

"Showering represents approximately 17 percent of residential indoor water use in the United States - more than 1.2 trillion gallons of water consumed each year."⁸  WaterSense key performance indicators for a good shower are pressure compensation, spray pattern, and effectiveness of the showerhead force. Although water experts say that there is little difference betweekn a 1.5 and 1.75 gpm shower, often the consumer resists lower flow shower aerators. Today consumers spend more and more time in the bathroom and typical residential bathroom are more like spa settings with whole body showers, large tubs, and multiple sinks.

Zurn's Sean Martin believes that consumer behavior modification will be an important part of managing the new flow fixtures. Particularly in dormitories there is a resistance to low flow showerheads. Education programs will help, but another solution may be new sensors which meter the amount of time a shower flows. Some new sensors can even regulate the timing of hot water to start when the occupant enters the showers.

ENERGY STAR - Hot Water Equipment

Laundry accounts for over 21 percent of water usage in the home. An average family runs approximately 400 loads of laundry per year. The EPA says that replacing pre-1999 washers can save the consumer over $145 per year. New washing machines can cut water and energy by over 40 percent. These new machines have no central agitator. They provide high-speed spin cycles, which have the added bonus of saving energy by requiring less drying time.⁹ ENERGY STAR steam washing machines can use as much as 77 percent less water and 81 percent less energy than the older models.

Other types of residential equipment that can save water are new dishwashers, which both conserve energy as well as water. ENERGY STAR-qualified dishwashers use at least 41 percent less energy than the federal minimum standard fcor energy consumption. Consumers should always run the dishwater with a full load and use an air-dry option for drying. Most of the energy used by the dishwasher is from heating water and hot water is a critical piece of the water and energy saving equation. Booster heaters which raise water temperature to the 140 degrees recommended for dish washing are sometimes automatic or require manual selection. Booster heaters allow the homeowner to save money by dialing down the thermostat on the main water heater.

Heating and distributing hot water is expensive in both commercial and residential applications. Hot water heating accounts for approximately 18 percent of the household energy budget. The basic principals for design of an efficient hot water system include:

• Providing the heat source near the point of demand
• Use convection and heat exchanges to re-use and recycle hot water

New water heating technology can provide the following savings:

High efficiency water heaters have better insulation, more efficient burners and vents and are designed to save energy. New tankless hot water heaters can often be located near the source of water demand, removing long plumbing runs to distant bathrooms in homes and offices.

Hot water solar systems reduce heating but require sites which are:

• Receive direct sunlight between the hours of 10 am and 4 pm year round
• Face within 15 degrees of south
• Designed to integrate within the roof structural system
• Have freeze protection in some climates

Waiting for hot water to reach the faucet is one of many ways that water is wasted. Cross linked polyethelyne tubing has been used since the 1960's for hot and cold distribution and for radiant heating. These systems run individual smaller, hot and cold supply lines throughout a system with "breakers" close to the demand source shortening the time for hot water to be supplied to the faucet.

Recirculating water and using heat exchange systems is another way to save water and energy. Buildings can be designed to use the heat storage properties of water to save energy.

WATER RE-USE

Gray water is the recapture of water which has been lightly used in domestic or commercial equipment. Wash water, liquid waste and shower water can be recaptured, treated and re-used in irrigation, and in some cases, highly treated to be re-used in the domestic water supply. Managing stormwater is a design opportunity that can be openly celebrated and embraced, as in the unique stormwater art projects by Herbert Dreiseitl. Conversely, stormwater, wastewater and groundwater can cause damage to foundations, concrete basins, pools and slabs, creating a maintenance burden for facilities managers.

When water causes damage, repair mortor can be used for the patching and resurfacing of deteriorated concrete. Crystalline waterproofing mortars are formulated to produce, low shrinkage, chemical durability and strength when aplied to concrete surfaces. Some products are mixed with a cementitious slurry coat to above or below-grade concrete and applied on sealing strips at construction joints to repair cracks. Water damage at foundations can be repaired to resist extreme hydrostatic pressure. Crystalline coatings do not require a dry surface, and can be applied to the positive or the negative side of a concrete surface providing an integral part of a substrate in a water containment system.

As a preventative application, a crystalline dry shake application can be applied to horizontal concrete surfaces. The active chemicals of this dry powder react to the moisture of fresh concrete causing a catalysic reactin which generates a non-soluble formation within the pores and capillary tracts of the concrete. This application is recommended for sewage and water treatment plants, foundation slabs, bridge decks, below-grade parking and water reservoirs and can seal hairline cradks up to 0.4 mm. Some of the advantages of this application is that the concrete will have a greater resistance from extreme hydrostatic pressure from either positive or negative surfaces of the concrete slab and will be highly resistance to aggressive chemicals.

Crystelline concentrate applied to the foundation wall of the corporate headquarters of Hektor S.A. Photo courtesy of Xypex Chemical Corporation

 

GLOBAL ISSUES

Entrepreneurs like T. Boone Pickens are betting that water may be the new oil¹⁰ and they are investing in private pipelines and buying up water rights. With an eight year drought in Western United States, a 280-mile pipeline which stretches from Lake Havesue to Tucson, there is no doubt that water use and conservation is serious. Data shows that across the world, water is a precious resource. As the annual rainfall in the United States has dropped, the population has increased. In the U.S. alone, water regulations both encourage water conservation and restrict water use in order to preserve our drinking water.

The conservation of water is among the greatest challenges of the future as this thirsty planet grows in population. Design professionals must continue to design buildings that are part of the water cycle and through an integrative design practice, restore water quality and conserve water resources.

The Monterey Bay Idea House

Designed to showcase numerous sustainable design features, the Monterey House is an example of integrated water design including a constructed water conservation system under this entry forecourt. Photo courtesy of BTL Liners, Inc. Thirsty California has numerous water regulations and incentives to encourage designers to save water. The Monterey Bay Idea House, was designed and built to showcase sustainable design. Harvesting rainwater allowed the designers to increase the building footprint and add bathrooms. On this tight site, stormwater detention was accomplished through the installation of a gray water source used for toilets and irrigation. A 49-foot long x 39-foot wide and 6-foot deep excavation was installed with an impervious reinforced liner and 65 recycled containment chambers providing water storage. This system was covered with granular fill, stormwater drains and a pavement cap that is the parking area for the home. All runoff from the roofs and pathways is directed into this system through a filter into pump basins that can be directed for re-use as irrigation water

 

EndNotes 1  http://www.epa.gov/owm/water-efficiency/water/save/use.htm 2  http://www.drinktap.org/consumerdnn/Default.aspx?tabid=85 3  http://www.epa.gov/watersense/water/simple.htm#fix 4  http://www.allianceforwaterefficiency.org 5   http://www.cuwcc.org/uploadedFiles/News/Articles_Resources/2009/Watersmart-Guidebook-Dec08.pdf 6   http://www.dailynebraskan.com/news/architecture-students-celebrate-legendary-urinals-1.1030225 7   http://www.epa.gov/watersense/pp/urinals.htm 8   http://epa.gov/watersense/pp/showerheads.htm 9   http://www.energystar.gov/index.cfm?c=clotheswash.pr_clothes_washers 10   http://www.businessweek.com/magazine/content/08_25/b4089040017753.htm

 

Celeste Allen Novak AIA, LEED AP, principal at RizzoloBrown & Novak Architects in Ann Arbor, Michigan, teaches sustainable design at Lawrence Technological University and is the author of articles focusing on sustainable building materials.