WHAT BUILDING TEAMS CAN DO 1. Design buildings to reduce cooling load. One of the most cost-effective ways to save water in new commercial, institutional, and industrial buildings is to design them to reduce the HVAC load as much as possible. This means paying strict attention to site orientation, building envelope tightness, daylighting, ventilation—that is, using all the powers of susta...
1. Design buildings to reduce cooling load. One of the most cost-effective ways to save water in new commercial, institutional, and industrial buildings is to design them to reduce the HVAC load as much as possible. This means paying strict attention to site orientation, building envelope tightness, daylighting, ventilation—that is, using all the powers of sustainable design you can muster to slim down those cooling towers, which are the biggest consumer of water in CII building projects.
2. Take advantage of cooling tower management technology. The use of conductivity meters and automatic controls to conserve cooling tower water is becoming fairly routine for many Building Teams. Every effort should be made to maximize blowdown water usage, with a minimum target of 5-6 cycles of concentration for blowdown use. Single-pass systems should be anathema. Where available, purple-pipe water should be used for condensate replenishment. “A well-run tower will only return 15% of the water to the sewer,” says H.W. (Bill) Hoffman, a highly respected water consultant.
3. Consider alternatives to cooling towers. Groundwater systems, underfloor air distribution, and so-called dry systems like variable refrigeration volume systems are options that should be considered for every project. First-cost issues must be evaluated, but these systems may prove cost-effective over the long term, especially for owner-occupied buildings. Groundwater systems in particular are becoming increasingly popular with smart-thinking building owners and developers.
4. Design water and drain lines for optimal performance. In new construction, drain lines that are not properly sloped, have too many elbows, or are not properly sized can result in drain line clogging, especially as plumbing fixtures use less and less water. This is important in spread-out projects like malls and suburban office campuses, and in one-story single-family homes, where there is less verticality to the pipes.
Hot water lines should be designed for efficient transport of hot water from the heating source to the sink or shower. This is especially true in new home construction, where plumbing design is often an afterthought.
In retrofits of high-efficiency fixtures, especially toilets, make sure existing drain lines can function properly with the reduced volume of wastewater flow.
5. Get the landscape architect involved early in the job. Landscape architects are more than just “plant people.” They can enhance the water performance of your project through the innovative design of rainwater harvesting systems, stormwater retention, rain gardens, vegetated roofs, bioswales, pervious pavement, structural soils, turf reduction, even so-called “green streets” (a requirement in Portland, Ore.) Don’t wait to bring in the landscape architect as an “add-on” after the basic form of the building has been set. The landscape architect should be a charter member of the Building Team, charged with optimizing the performance of the site —especially its water performance—within the overall program of the building.
6. Become the expert on water rebates and incentives. AEC firms and home builders should make themselves the knowledge source regarding rebates, incentives, and grants for water conservation on behalf of their clients. Example: Rain Bird, a maker of high-efficiency sprinkler systems, has a link to a dozen state incentive programs for water-related rebates (http://www.rainbird.com/iuow/resources/watersavingsrebates.htm).
Here’s how it can work: A few years back, HDR Architecture was able to convince client Banner Bank to install a massive storage tank for rainwater harvesting, thanks largely to a 60% grant from the EPA. HDR’s David Gibney found out about the grant program through a Google search. The rainwater system contributed to the Boise, Idaho, project achieving LEED Platinum.
7. Engage in water management planning. Water management planning involves taking a comprehensive look at how water is used in buildings, especially for large corporate complexes, military bases, university campuses, hospital complexes, and the like. The basic idea, according to consultant Kate McMordie, is to compare the amount of incoming water supply with the projected actual use for each building, based on such factors as the number and kinds of toilets, urinals, sinks, and cooling towers, as well as landscape irrigation requirements.
There can be a substantial difference between the theoretical use and the actual amount of supply to a large campus—a 10-20% difference is not unusual, although McMordie has found one as great as 50%. Owners whose buildings are using substantially more water than the theoretical amount should go to the next step.
8. Conduct water audits. Water audits can yield detailed information about problems with mechanical and plumbing systems that can save money fairly quickly. As in the case of building commissioning, a water audit can reveal anything from a minor problem—a loose connection in a pipe system—to major flaws in, say, the building’s cooling towers. A water audit for a 10-story office building would run about $5,000, according to consultant Bill Hoffman. In some localities, a WASCO, or water service company, may perform the audit at a lower cost and get compensated based on the savings it produces, much as an ESCO does for an energy audit.
9. Harmonize plumbing codes for water reuse. This is a biggie. In most jurisdictions, plumbing and building codes make it difficult to impossible to use innovative rainwater harvesting and graywater reuse, especially for indoor use. NSF International is conducting research on the health, safety, and public welfare of reused water, and IAPMO’s new green supplement offers language for states and cities to use if they choose to permit this technology.
What is needed are case studies, data, and research to demonstrate the feasibility—and value—of graywater reuse in large commercial buildings and rainwater harvesting in both homes and commercial buildings. It’s too inefficient for Building Teams and home builders to be trying to implement graywater and rainwater reuse in their projects on a case-by-case basis. However, local and state governments could encourage carefully supervised pilot projects to experiment with different systems or designs. The plumbing industry and government need to nail down the science and clinical aspects, see what really works, and then overlay the technical design and construction details onto building and plumbing codes to make this “next big thing” happen.
10. Consider water-use labeling on sale or transfer. Water-use labeling is a system whereby property owners would be required to have their buildings or homes audited for water performance at the time of sale, transfer, rental, or lease. Such a system has been in use for energy labeling in the U.K. and Europe for a number of years, and ASHRAE has recommended the use of energy labeling in the U.S.¹
Water-use labeling would give prospective purchasers, renters, and lessees information that could be used to determine the sales or rental value of the property. Presumably, a highly efficient building or home with up-to-date plumbing and irrigation systems would bring more in the market than one with out-of-date equipment or poor water performance.
However—and this is important—with water-use labeling, the seller would not be required to make upgrades; that would become part of the sale or lease negotiation. This factor makes water-use labeling different from a “replacement on transfer” requirement, versions of which are already in effect in several cities in California (including Los Angeles, San Diego, and San Francisco) and which is being proposed for statewide adoption in California. Under proposed SB 407, starting in 2014 homeowners and apartment building owners making improvements to their properties would have to replace all noncompliant plumbing fixtures; multifamily and commercial properties up for sale would have to replace noncompliant fixtures before a final permit would be granted.
The gravity of the situation in California may give “replacement on transfer” some validity, but we think it advisable for other states and localities to start with market-based mechanisms like water-use labeling. If the jurisdiction finds that the more “voluntary” approach doesn’t work, it could move up the scale to stricter regulation.
However, public officials should heed the warning of water consultant John Koeller, who has cautioned that mandating high-efficiency fixtures in retrofits without careful evaluation of the ability of plumbing and drain lines to function with less water in the system could lead to major problems, especially in older buildings and homes.
11. Use IAPMO’s green plumbing supplement as a guide. The IAPMO Green Plumbing and Mechanical Code Supplement provides a consensus-based vehicle for states and local jurisdictions to resolve several of the most nettlesome conflicts between sustainable design and existing building, plumbing, and health codes. The document: 1) provides guidance to state and local officials on reusing water (notably graywater, rainwater harvesting, and purple pipe) to supplement the potable water supply; 2) describes best practices for avoiding problems like drain line clogging; 3) supplies language and standards for the use of high-efficiency plumbing and mechanical products; 4) shows how to achieve optimal results in hot water systems, thereby saving both water and energy; and 5) provides practical advice on the water-performance aspects of cooling systems in commercial, industrial, and institutional buildings.
The IAPMO code supplement will be available in February 2010. State and local plumbing and building officials should give it priority consideration.
12. Address the infrastructure problem. If you laid the water pipes that are more than 80 years old in this country end to end, you could circle the planet nearly three times. Because much of this ancient pipe is falling apart, at least 10-20% of the nation’s potable water (and more in older cities) simply never makes it to its intended point of use. And as we have noted, considerable energy is also wasted pumping water that leaks from the system.
The American Water Works Association says an investment of $250 billion over 30 years is needed to repair or replace worn-out water pipes, valves, fittings, and so on. To meet these costs, AWWA recommends that the federal government do two things: 1) increase funding to the State Revolving Fund programs, which provide low-interest loans to local utilities for such improvements, and 2) create a “Federal Water Infrastructure Bank.” The FWIB would provide financial assistance for large water infrastructure projects of national or regional importance ($75 million or more) with loans at the U.S. Treasury bond rate. In addition, the FWIB would purchase or guarantee State Revolving Fund bonds, thereby lowering the interest rates on these bonds.
Whether such a water infrastructure bank is merited is somewhat beyond our brief in this White Paper. Regrettably, the most likely scenario is that our ever-decaying water infrastructure will not get its due until some cataclysmic event grabs the headlines. Until then, the nation’s 54,000 water utilities will have to plug along with business as usual.
13. Be more creative in pricing water. Water is cheap—too cheap, in the view of many experts in the field, especially for potable water that is not used for drinking, washing, or other direct human use. Because water is relatively so cheap, it’s hard to get property owners to reduce their use, especially for landscape irrigation (and, to some extent, for cooling towers in commercial buildings). Moreover, homeowners and building owners are used to water rates being subsidized. There’s the further complication that most utilities charge based on volume, so reducing water use may be seen as not in their best interests.
For these reasons, a tiered system—a basic service fee for a pre-established floor of indoor water consumption per occupant, followed by higher fees for use above the base—may be the best pricing mechanism to encourage water conservation.
Nine years ago, Greensboro, N.C., established a four-tiered price system, coupled with a billing and availability fee for fixed costs. Households that saved water were rewarded with a lower rate and lower bills; others paid the price for water gluttony. Over the first seven years of the program, household consumption fell 22%.²
Tiered pricing should also be linked to wastewater treatment fees, so that buildings and homes that saved water and thereby sent less wastewater back to the treatment plant should also reap the benefit of lower sewage treatment bills.
14. Provide incentives for water audits. Water utilities rely on volume to stay afloat, so it may seem against their best interests to encourage water audits, which would result in less water usage. However, with the prospect of drought or water scarcity throughout most of the U.S. in coming years (not to mention the stressful impact of climate change and population growth on water resources), utilities need to offer these incentives to building owners and homeowners before a crisis hits.
15. Implement metering innovations. One of the problems with water is that a lot of it seems to disappear, and nobody knows how or why. Metering and submetering commercial and institutional buildings, apartments/condos, and single-family homes can help alleviate this problem by influencing end-user behavior and overcoming the “out of sight, out of mind” problem.
And it works. Austin, Texas, has found that submetered apartments use 15.3% less water than master-metered multifamily properties. In 2008, it required submetering in all multifamily buildings.³
Another technology, automated meter reading, uses radio-frequency technology to read water meters from the street. The advantage of AMR is that it can pick up anomalies—for example, a home with minimal landscaping and an unusually high water bill might have an undetected leak. Both New York City and the District of Columbia Water and Sewer Authority have implemented AMR systems, with good results.
16. Support research on water performance issues. Plumbing fixture makers have played a valuable role in partnership with EPA WaterSense and other organizations in the development of high-efficiency faucets and showerheads. The industry has set up the Plumbing Efficiency Research Coalition to study the drain line transport problem. It is in the best interests of groups like the Plumbing Manufacturers Institute, the plumbing trade unions, and related associations to support research that will remove roadblocks to innovation and progress in sustainable design and construction.
17. Support the growth of green plumbing jobs. GreenPlumbers USA is making headway in its efforts to retrain 40,000 plumbers to make more efficient and effective sustainable plumbing systems in homes and buildings. Plumbers’ unions and the United Association of Plumbers and Pipe Fitters should be in the forefront of the water performance movement, not only out of self-interest but as a demonstration of their leadership and public service. Manufacturers can play an important role in providing technical expertise, product samples, demonstration sites, and financial support for local, state, and national green plumbing training programs.
18. Create a “pre-apprentice water auditor” certification program. Last year, we recommended the creation of an associate’s degree in building commissioning as a way to enable more buildings to be commissioned.
So that more water audits can be performed, we support the proposal put forth by Steve Lehtonen of GreenPlumbers USA for community colleges to create a curriculum for “pre-apprentice water auditors.” Graduates would be trained to assist professional water auditors, thus “stretching” the workforce and possibly reducing the cost of water audits. This certification will become even more valuable when the WaterSense New Homes program goes into effect.
If we can have Certified Energy Managers, LEED Accredited Professionals, and, now, Green Globes Assessors and Professionals, why not pre-apprentice water auditors and other water-related professional certifications? Here’s another excellent opportunity to create interesting and well-paid green jobs.
19. Use less turfgrass, more native landscaping. This will require a major shift in the aesthetic mindset of the majority of American homeowners and commercial-institutional property owners. The well-groomed lawn has taken on a symbolic image that will be hard to erase from the American psyche. Nonetheless, efforts like the prairie restoration movement in the Midwest and various forms of native and Xeriscape landscaping have shown that the use of indigenous plants can be both beautiful and ecologically sound, especially with regard to water use.
20. Irrigate sensibly. If irrigation is still required, homeowners and property managers need to consider the use of high-efficiency irrigation systems that are based on the regional climate, local weather and soil conditions, the types of plantings, and so on. These systems can prevent the most egregious errors, such as watering during a rain storm.
21. Understand the energy cost of water. The public needs to appreciate more fully the energy cost of transporting and treating water and wastewater, and the resultant impact on greenhouse gas emissions and climate change.
With climate change adding to water scarcity and drought, the coming decade will demand our attention to water performance. “Water restrictions, mandates, rationing—Australia, Israel, and other parts of the world have already faced these issues,” says Sean McGuire, staff liaison with the Mechanical Contractors Association of America. Their experience is “a preview of what may happen here in five or 10 years.” The time for action is now.