Government Buildings and Public Facilities Introduction
There are numerous water saving measures and retrofits available for government facilities. The water use profile often leads to short payback periods, and the facilities are usually a significant portion of a utility’s institutional sector water use. The greatest impediment to achieving water savings in this sector is the fiscal budgets. Even if the recommended measures are cost-effective, the facility manager usually has to submit a budget request that can only be approved for the following fiscal year. Water saving potential is enormous, but success implementation requires a cooperative effort from everyone involved, and patience for financing to become available.
Government agencies are usually very enthusiastic about water conservation measures because they want to set a good example to the public they serve. Many water utilities use government facilities as demonstration projects to promote water conservation and showcase water-efficient products and technologies. The facilities often offer easy access for the public to see and use. Unlike businesses, government entities are often willing to include and promote water conservation measures that are relatively new and unfamiliar. These projects also lend themselves to photo opportunities with civic leaders to endorse and promote the project.
Some utilities provide water to government facilities, free of charge. In many such cases, water meters were never installed. This was a common practice where municipally owned water utilities delivered water to municipal buildings, parks, sports facilities, etc. As we have now learned, this leads to enormous water waste. There is no incentive to fix leaks and improve water efficiency when the water is free. At the very least, meters should be installed and read regularly to monitor water use in order to detect significant leaks and equipment malfunctions. Facility managers should be held accountable for excessive water use. The facility manager needs to monitor monthly water use and be alerted when water consumption suddenly increases without explanation.
In many ways, most conservation measures in government facilities are similar to other facilities in the commercial and institutional sectors (offices, hospitals, housing, schools, etc), depending on the function of the facility. The most common water conserving opportunities are as follows.
Water savings can be achieved by replacing older model toilets using 3.5 gpf (13.2 lpf) or greater with new ULFTs (1.6 gpf (6.1 lpf)) and HETs (1.28 gpf (4.84 lpf) or dual flush toilets using 1.6 gpf for solid waste and up to 1.0 gpf (3.78) for liquid waste). The frequency of toilet flushes per toilet is often greater in offices than in homes, although the frequency is highly variable from facility to facility. It is reasonable to assume an average of 2 to 4 flushes per person per 8 hour shift. Depending on the type of facility, visitors might also incur additional flushing activity. When conducting benefit/cost analyses, it is important to separate the calculations for women’s toilets versus men’s toilets for two reasons: (1) the ratio of men’s room toilets per male worker is usually different than the ratio of women’s room toilets per female worker; (2) men will most often use urinals (when available) rather than toilets. Every facility is unique in its flushing frequency. While it is reasonable to use average toilet usage estimates for program planning; performing toilet retrofit projections on individual facilities requires calculations based on unique site data. A sample calculation might be:
Data: 260 work days per year
300 male workers, 200 female workers
10 male toilets, 15 urinals
25 female toilets
Male Toilet Flush Quantities:
260 days X 300 males X 0.5 toilet flushes/day = 39,000 toilet flushes/year
39,000 flushes / 10 toilets = 3,900 flushes/year/male toilet
Male Urinal Flush Quantities:
260 days X 300 males X 2.5 urinal flushes/day = 195,000 urinal flushes/year
195,000 flushes / 15 urinals = 13,000 flushes/year/urinal
Female Toilet Flush Quantities:
260 days X 200 females X 3 toilet flushes/day = 156,000 toilet flushes/year
156,000 flushes / 25 toilets = 6,240 flushes/year/female toilet
Conclusion: This example shows replacing female toilets will garner nearly 35% more water savings compared to male toilets.
The predominate type of toilet in government office buildings is flush-o-meter toilets, though gravity toilets are found occasionally. Both the bowl and the flush valve of the flush-o-meter toilets must be replaced to assure water savings and adequate flushing performance. The cost to replace a flush-o-meter type toilet usually ranges from $250 to $400, depending on the type of toilet required. Wall-mounted toilets are usually the most expensive to replace, and toilet models suitable for such retrofits are limited.
As with all toilets in the commercial sector, there are a few extras items to consider:
- Building maintenance staff must be trained to only use the proper parts when servicing the flush valves, or all water savings will be negated. Unfortunately, 3.5 gpf (13.25 lpf) parts often fit the new 1.6 gpf (6.1 lpf) flush valves.
- Replacement options include the 1.6 gpf (6.1 lpf) toilets, and there are now 1.28 gpf (4.8 lpf) models and dual flush models available. While there are many gravity type toilets suitable for light commercial applications, flush-o-meter types or pressure assist models preferable in most commercial buildings.
- Sensor flush mechanisms often result in more frequent toilet flushing than manual flush valves. There is no evidence the sensors valves save water.
- If installing dual flush toilets, it is wise to post instructions for the toilet users.
- Disposable seat covers and paper towels are the most common causes of clogged toilets. Consider alternate methods of hygiene (sanitizers, continuous roll seat cover dispensers, hot air dryers, etc.), or select new toilets models that exceed 500 grams in MaP Testing.
- Flushing performance is very important for success. Refer to the MaP testing results before selecting new toilets.
The benefit of replacing urinals is highly dependant on frequency of use and the proposed replacement. Frequency of use is determined by calculating the quantity of male 8-hour shifts, the average urinal flush per man per 8-hour shift (usually 2 to 4), and the quantity of urinals. Similar to toilets, visitors to the government facility might affect additional urinal flushes.
There are many options now for urinal replacements; from simply replacing the flush valve to reduced flows, to replacing the entire urinal to non-water use models. All options vary in the costs and benefits. In many cases, minimal water savings can be achieved by simply altering the urinal flush valve to a lower GPF diaphragm on flush-o-meter urinals, though some older urinals will not properly function at these reduced flows. Unfortunately, this type of valve-only retrofit can be easily and mistakenly reverted back to the higher flush volume during routine maintenance. Much consideration is needed to determine the best retrofit or replacement for any given office building. To assure water savings are maintained over time, the best strategy is to replace the entire urinal and flush valve with a 0.125 gpf (.47 lpf) or 0.25 gpf (.94 lpf) model, or a non-water urinal.
As with all urinals in the commercial sector, there are a few extras items to consider:
- Building maintenance staff must be trained to only use the proper parts when servicing the flush valves, or all water savings will be negated. Unfortunately, 3.5 gpf (13.25 lpf) parts often fit the new 1.0 gpf (3.78 lpf) flush valves.
- Sensor flush mechanisms often result in more frequent urinal flushing than manual flush valves. There is no evidence the sensors valves save water.
- Non water urinals are considered compliant by most plumbing code authorities. The Uniform Plumbing Code and the International Plumbing code allow the urinals, but some local cities and counties have not yet approved the devices.
Flow rates for wash basin faucets in lavatories can reasonably be reduced to 0.5 gpm (1.8 lpm) or lower. (The current national standard and all of the major model plumbing codes in the U.S. call for a maximum flow rate in non-residential lavatory faucet installations of 0.5-gpm(1.8 lpm).) Projected savings are usually based on usage frequencies similar to toilet and urinal use. Flow durations are often estimated to be 5 to 30 seconds per use. Retrofitting aerators on the faucets is the most common and least expensive strategy. The water savings are small when compared to replacing toilets, but the cost of retrofit is minor, usually less than $1.00 per faucet.
Some wash basins are fitted with mechanical metering valves (automatically shut-off after a preset time span) or negative shut-off valves (user must continue to exert pressure on valve handle to maintain water flow). These types of valves are required to save water and deter flooding the lavatories. The valves are often adjustable for the duration of the flow. The flow should not exceed 5 seconds per activation.
There is no scientific evidence that sensor-activated faucets save water. To the contrary, recent studies have provided valid evidence that sensor faucets use much greater water than manually activated valves. Sensor activated valves provide user convenience, but are now known to be wasters of water.
Government facilities might also provide opportunities to conserve water used to irrigate surrounding landscape, especially office complexes with extensive common area landscaping. These landscapes are notoriously over watered because: (1) the landscape is maintained by a contractor that does not pay the water fees; and, (2) the landscape is usually irregularly shaped without zone separation between turf and lower water use plants. The greatest difficulty in achieving irrigation savings is coercing the facility manager to make the landscape maintenance contractor responsible for water use and waste.
Demonstration gardens are an excellent way to allow the public to see regionally appropriate landscape (referred to as Xeriscape) vegetation, techniques and equipment. Much of the public still have the misconception that a water efficient landscape is only sand, rocks, and cacti. Promoting drip irrigation and other efficient irrigation equipment is more effective when the public has an opportunity to see, touch and experience the measures promoted. Government facilities that have open and convenient public access are excellent venues for installing water efficient demonstration gardens.
Most large government buildings (more than 10,000 square feet (929.03 square meters) employ the use of a cooling tower in the HVAC system to cool the building. Cooling towers use the cooling effect of evaporating water to remove heat from water circulating through the HVAC equipment and chillers. There are numerous ways for the system to waste water when the system is not properly maintained. Depending on the climate zone and the cooling system, the water wasted can be greater than all the sanitary fixtures combined. Appropriate retrofits usually require a conductivity controller be installed and properly maintained to achieve water efficiency. Conductivity controller retrofits, usually cost less than $1,500 per cooling tower, can save more than $800 per year for a typical office building.
Cooling tower retrofits and maintenance should be part of every water conservation program targeting office buildings. There are ample technologies available to greatly improve the water efficiencies of most cooling tower systems. Technology provides the tools for water savings, but does not guarantee water efficiency. Controller installations and retrofits must be part of an overall customer maintenance and education program to be effective.
Where the local wastewater treatment agency provides reclaimed water (wastewater treated to drinking water standards, though deemed non-potable), government facilities provide an opportunity to supplant potable water use with reclaimed water use. Landscape irrigation is the most obvious opportunity to use this water. Reclaimed water can also be used to supply water to toilets and urinals. Depending on the water quality requirements, many cooling towers can also use reclaimed water rather than potable water.
In all applications, the reclaimed water must be strictly separated from potable water sources and end-uses. This requires a clear separation of pipes supplying water to the end use (irrigation system, toilets, urinals, cooling tower, etc) from pipes supplying potable water to faucets, drinking fountains, etc. Irrigation systems are usually on separate meters and water supplies; thus, this is the most common application for reclaimed water use.
The water supply pipes for toilets and urinals are often interconnected with faucets and drinking water fountains; requiring extensive plumbing system retrofits if reclaimed water is to be used. Retrofitting a pre-existing plumbing system inside an office building is usually too costly to justify the use of reclaimed water to flush sanitary fixtures.
When constructing a new facility, the cost to separate the water supply pipes for sanitary fixtures is marginal. Many water agencies are now requiring new office buildings to be dual plumbed to separate the plumbing so reclaimed water can be used to flush sanitary fixtures, even if reclaimed water is not immediately available. Plumbing contractors report this usually adds less than 15% to the total cost of the plumbing system.
Storm Water Collection and Use
Collecting the storm water or rainwater on the building site (roof, parking lot, hardscape, landscape, etc.) is one of the fastest growing strategies in the water conservation industry and the “green” building efforts. There are three distinct advantages to this strategy:
- The collected water can be stored then used to irrigate the landscape during dryer months.
- The water collected is prevented from entering the storm water system, which is often overtaxed in urban areas causing flash floods.
- The pollutants from the building site (fertilizers, herbicides, pesticides, animal waste, automobile fluids, etc) are prevented from being carried by storm water to streams, rivers, and other aquatic ecosystems.
Some government facilities prepare and serve food; and this presents excellent opportunities to conserve water in the areas of food preperation and dish washing. Food is often heated in steamers using a central boiler; connectionless steamers are alternative equipment that saves thousands of gallons of water per year.
Pre-rinse spray valves, using 4 gpm (15.1 lpm) are used to rinse dishes before placed in the dishwasher; new efficient spray valves use only 1.6 GPM (6.1 LPM) and save hundreds of gallons per day (depending on volume and type of meals served).
Ice machines are commonly found in food service facilities; and this equipment can use surprisingly excessive amounts of water. Depending on the model and the settings, ice machines use 2 to 18 pounds (.91 kg to 8.16 kg) of water for every pound (.45 kg) of ice produced.
The water efficiency of commercial dishwashers also varies greatly. The high cost of these machines often impairs the benefit-cost ratio of early replacement; but as older dishwashers fail, high efficiency models should be installed as replacements.
Hardscapes (sidewalks, decks, walkways, etc) are often sprayed with water from a hose and nozzle as part of a cleaning regimen, especially outside of food service facilities and sporting venues. While dry sweeping the surfaces with a broom is preferred, health and sanitation regulations might require the food be rinsed off the hardscape with water. The traditional hose and nozzle uses more than 5 gallons per minute (18.9 lpm), while water brooms use less than 1 gallon per minute (3.78 lpm). Water brooms use an array of high velocity, low water volume nozzles to scour the surfaces. The majority of users also attest the water broom cleans the surfaces faster and cleaner than the traditional hose nozzle method.
Some specialized government facilities are featured in other areas of this web site. The following are links to specialized facilities that might also be part of government facilities:
Universities and Colleges
Large Landscapes (parks and golf courses)
GE Water (2007) Solutions for Sustainable Water Savings - A Guide to Water Efficiency