by Chris Hodges, P.E., CFM, LEED AP, IFMA Fellow, FRICS — Facility managers are faced with a number of challenges in making their buildings perform better. For some time now, we have been asked to reduce consumption of energy and water, reduce consumables and waste, and make our buildings healthier and more comfortable. The primary driver of these initiatives to improve performance has been economic — improvement is often beneficial to the bottom line. Because of the emphasis on the economic improvement, a number of conservation issues have been lagging. Water often falls into that category.
Just about everyone can quote the current price for a gallon or liter of gasoline, but when was the last time you checked on the price of water? Water is widely known to be undervalued. It’s still a relatively inexpensive and plentiful natural resource in most developed areas of the world where we operate large buildings. Water scarcity in most well developed economies is a regional issue. Few governments have national water-use policies, and there is not a lot of emphasis on water use in buildings. However, that’s where our workforce tends to use a lot of water in daily life.
Green building programs have brought water use issues in buildings to the forefront. However, the lack of economic drivers to conserve has led to a focus on the “low hanging fruit” of water conservation — the reduction in the amount of water delivered at the fixture level. There’s a lot more we can do.
Facility managers are taught to think strategically. The job of the FM is filled with competing priorities that often result in more demands than there is time to fulfill them. There’s not a lot of time to think strategically, but the most success comes to those that can think ahead, plan, and anticipate future needs. Now is probably a good time to think about water use strategically. The positive news is that there are a number of countries and regions of the world that have had to deal with water as a scarce resource for quite some time, so there is an experience base from which we can learn. There have been a number of studies on water use in buildings that can benefit the facility management community.
It is sometimes helpful to look at building water use in terms of inputs, uses, and outputs. On the input side, we have either a municipal source, or an on-site source. Other inputs may include purchased water, particularly for domestic drinking water use. While this may not account for a large part of an organization’s water budget, the unit price of bottled water is quite high compared to water purchased for other uses. Water use in buildings falls into three categories:
- Domestic water
- Process water
- Irrigation
For buildings, domestic water includes that which we use for washing, bathing, cleaning, waste removal, and in food service functions. Consumption of domestic water is controlled by the fixtures in the building. Process water includes water that we use in heating and cooling, and irrigation water is used in landscaping. Water outputs in a building include wastewater, evaporation, and leaks. Evaporation can account for a significant water loss in building systems that rely on evaporative cooling towers. Leaks can also account for a significant quantity of water use if they are not detected and corrected in a timely manner. In taking a strategic approach to improving water performance, all inputs, uses, and outputs should be considered.
Water performance of buildings is defined as the overall water consumption. If we were to start thinking about water use in buildings on a more strategic level, there are three approaches to water performance in buildings that are worth considering.
Key Fixtures Approach — The key fixtures approach uses the premise that a building is water efficient if the fixtures within the building are efficient. Water efficient toilets, urinals, lavatories, showers, and food service equipment are targeted and designed (or replaced in existing buildings) for the highest level of water savings. By setting water efficiency requirements at the fixture level, we can take advantage of current water savings technologies and feel comfortable that our major water uses in buildings have been economized. The advantage of this approach is that it is simple to implement, and there are a number of labeling programs that guide us to the most efficient fixtures. A major disadvantage is that it does not take other water conservation strategies into account and the “whole building” approach to water management is ignored. The other potential disadvantage of the key fixtures approach is that once we have upgraded our fixtures, there may not be any more incentive for improvement until the next round of technology hits the fixtures market.
Global Water Consumption Approach — This approach considers the overall water consumption of the building, including the consumption of the fixtures. It uses a net-water use metric for determining total water use. Using the overall consumption approach gives “credit” for water reduction strategies such as rainwater harvesting and gray water use. In this approach, the water consumption of a comparable standard building is determined as a reference value. A standard building would be one that uses standard or non-water-saving fixtures. The water consumption of a building is then compared to the standard building with non-water-saving fixtures. Credit can be given for buildings that consume less than a standard building. This methodology is the basis for the water rating category of several green building rating systems such as BREEAM and LEED. The standard water metric for a typical building is expressed in a “per person” or “per area” metric. For example, according to the Watermark program in the UK, the standard benchmark for water use in buildings is 9.3 cubic meters (2456 gallons) of water per person per year. The Watermark program establishes the “best practice” level of water performance at 6.4 cubic meters (1690 gallons) per person per year. To understand the overall water consumption of a building, it is necessary to measure and monitor water use. Baseline use is determined by taking an inventory of fixtures and flow rates, and establishing a standard number of uses for each fixture per building occupant (usually derived from the plumbing codes). Reduction targets are determined and strategies such as fixture replacement, rainwater harvesting, gray water use, food service strategies, and irrigation strategies are put in place. Water use metrics are then monitored for improvement.
An advantage of the global water consumption approach is that allows the facility manager to benchmark water performance against others. A disadvantage is that the benchmark is often established against non-water saving buildings (i.e.: old plumbing codes). Once the market improves water performance of buildings and new codes are in place over the next few years, a new benchmark is required. This will require a fresh look at how to continue to improve water conservation.
Water Management Plan (WMP) Approach — this approach is more strategic in nature. It incorporates the fixtures approach and the global water consumption approach in order to reduce consumption. The primary concept is to meter and target. As with energy, measurement and monitoring of water consumption is critical in establishing the baseline use that will allow the facility manager to establish reduction targets that make sense for the facility. Reduction strategies such as fixture replacement, gray water use, leak prevention and monitoring, and use of technologies to reduce cooling water loss in open loop cooling systems can be implemented once consumption is properly measured at the system level. The reduction targets are set by the facility manager based on actual consumption data.
Of all three of these approaches, the water management plan (WMP) approach offers the facility manager the greatest opportunity for continuous improvement. Consumption data is based on real data, not theoretical fixture and use rates, and it allows for the incorporation of the greatest number and variety of reduction strategies.
The other major advantage of the water management plan approach is that it allows facility managers to look at their water management strategy from the viewpoint of where it fits with other sustainable facility management initiatives. All sustainable facility management initiatives require coordination and integration with others. Managing water use in buildings is not merely an issue of reducing consumption. For example, the use of bottled water in facilities is both a water use issue and a waste issue. Changing policies toward one may cause an unintended change in the other. The facility manager is in the unique position to understand the organizational strategies, drivers, and incentives for sustainability initiatives.
Above all, an effective strategy for water management in buildings depends on the facility manager’s ability to measure, monitor and report water consumption. The ability to measure is dependent on an adequate and accurate metering plan. The ability to improve performance is dependent on how well the metering plan is sub-divided to account for water use at a system level. The greatest level of improvement will happen when the facility manager has adequate data on consumption, access to the technological improvements needed to reduce consumption at the fixture level, thoughtful strategies for process and irrigation water uses, and an eye toward reducing waste.
Water is not likely to be the facility manager’s most costly resource, but reduction strategies put in place now, and diligence in keeping an eye on the environment will put our organizations in a far better position when scarcity becomes the norm, and water becomes the costly resource many expect will become in the coming years.
Chris is a Principal with Facility Engineering Associates (FEA) of Fairfax, Virginia and currently serves as Chair of IFMA’s Sustainability Committee. FEA specializes in helping clients achieve high-performance in the operation of their facilities and achieving excellence in the delivery of facility management services.