3.6: CII Water Use

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What do a car mechanic and an aerospace engineer have in common? They both work in the Commercial, Industrial, and Institutional (CII) section, which is very diverse in terms of water use. Using water for cleaning as a car mechanic or water for manufacture of aerospace parts are very different uses. As we study CII customers, you’ll be able to bring together what you’ve learned about indoor and outdoor conservation and apply it to the workplace.

Learning Objectives

In this section, you will:

Classify customers according to type
Identify challenges in the CII sector
Analyze the consumption history of CII customers

For CII customers considering conservation, financial incentives are typically a useful conservation tool as well as providing information on the return on investment (ROI). One particular challenge in the CII sector is that a master meter typically provides water for both indoor and outdoor use. Sometimes an entire strip mall of diverse businesses (e.g., nail salon, microlender, lawn mower repair) will be behind the same meter. This makes it very difficult to account for individual commercial water use and to offer appropriate rebates and incentives. With the challenges in the CII sector understood, we will spend some time looking at each type of business within the CII sector.

Commercial, Industrial and Institutional Customers

Within the commercial, industrial and institutional (CII) sector, water use varies by type of customer. The EPA provides this bar graph of typical water use within different types of commercial and institutional organizations:

End Uses of Water in Various Types of Commericial and Institutional Facilities by the EPA is in the public domain — Figure $\PageIndex{1}$

There are a few key observations you can make, most of which are intuitive:

Most customers have a sizable proportion of domestic or restroom water use. This suggests that a program that rebates toilets, urinals, and aerators might be useful to many types of customers.

Schools, offices and hospitality (hotels) use a significant amount of water for landscaping. This suggests that a rebate program for smart irrigation controllers, sprinkler nozzles, landscape audits or checkups or for turf grass removal might be useful.
Some types of customers, such as hospitals or offices, have sizable amounts of water used for heating and cooling (including cooling towers, which can recirculate water).
Kitchens and hotels (hospitality) use a significant amount of water in the kitchen.

Commercial Customers

Restaurant water use is typically about 50% used in the kitchen, primarily for dishwashing. This suggests that a dishwasher rebate for a water-efficient dishwasher might be in order. And, of course, there is typically a third of total water used for restrooms, which suggests a toilet and urinal rebate program might be well received and needed.

End Uses of Water in Restaurants by the EPA is in the public domain — Figure $\PageIndex{2}$

Restaurants have other uses of water in the kitchen, including woks and dipper wells, both of which may have continuous flows of water. The next time you are in an Asian restaurant, if the restaurant has an open kitchen, check out the wok. Many restaurants have a continuous flow of water in a faucet behind the wok to use while cooking and to cool the wok. Similarly, dipper wells in ice cream parlors may also have a continuous flow of water to keep the ice cream scoop clean. For kitchen clean-up, pre-rinse spray valves, which are used to pre-clean dishes before going in the dishwasher, can also be upgraded to less gallons per minute, and are a common rebate program.

The EPA features a case study in conservation in a restaurant in Chicago, Illinois. The restaurant is called Uncommon Grounds and it conducted three stages of upgrades:

Aerators on prep sinks, more efficient pre-rinse spray valves and water only served on request
Dishwasher and ice machine upgrades to ENERGY STAR qualified models
Rooftop garden with a drip irrigation system that uses a rainwater collection system

This case study illustrates that there are a wealth of possibilities for upgrades, but that for restaurants focusing on the kitchen first often makes the most sense.

Hotels are another common customer type in the commercial sector. Their water use often encompasses a restaurant, but also restrooms, landscape, and laundry uses.

End Uses of Water in Hotels by the EPA is in the public domain — Figure $\PageIndex{3}$

Hotels may have more flexibility for implementing changes for water conservation if they are small and privately-owned or if they have sustainability as part of their mission, such as Kimpton Hotels. Small behavioral changes may be successful for hotels, such as instituting linens/towels re-use options for customers, particularly if customers have to “opt-in” for fresh daily towels or linens.

The EPA has a case study in water conservation in a hotel in a Holiday Inn in San Antonio Texas. The water utility spent $100,000 in a retrofit of guest bathrooms upgrading as shown below:

Fixture	Original Efficiency	Retrofit Efficient	Number of Units
Toilets	3.5 gpf	1.1 gpf	297
Toilets	5.0 gpf	1.1 gpf	100
Aerators	2.2 gpf	1.5 gpm	397
Showerheads	2.5 gpm	1.75 gpm	397

The hotel achieved an average of 35% savings per upgraded room and $68,000 in water and sewer costs per year.

Industrial Customers

The Mid-Continent Ecology Division Laboratory (MED) of the Environmental Protection Agency (EPA) can also be studied as a case study for water conservation. Located in Duluth, Minnesota, the MED is 50 labs, administrative offices, a library, and 7 constant temperature rooms. As with many scientific laboratories, there was a good deal of water used for cooling of scientific instruments. In particular, single-pass cooling occurred not only in the cooling system for the building but for many elements of the research equipment. Because the facility is adjacent to Lake Superior, the facility was able to use waters from the lake for cooling rather than potable water, which reduced its total potable use by 90 percent. Additionally, the water can be returned to Lake Superior after it is used to cool the building or equipment.

This use of lake water for cooling is innovative. In California, lakes are much more sporadically occurring than in Minnesota and this would be more of a challenge both in finding a lake to use and in not having detrimental environmental effects. Also, aquatic species tend to like water within a temperature range so any water that is returned to the lake would need to be similar in temperature to the lake water.

Institutional Customers

Although decreasing water use by 90% in the case of the MED or 35% for the Holiday Inn seems extreme, the types of processes and analyses that occurred at the MED are the sorts of processes that would need to occur are typical of ways to save with other industrial customers as well as institutional customers. Institutional customers are typically schools and universities, hospitals, houses of worship, and city and county agencies. These are typically the sorts of customers who may have many people visiting their facilities for a short period of time. They may also have a variety of different types of use in one building, such as a church that also has a school during the weekdays and group counseling or AA meetings in the weekday evenings.

Stanford University is useful as a case study because of the wide-ranging uses of the facility ranging from scientific research to residential housing. At Stanford University, conservation staff met with each department to attempt to quantify water use and potential reductions. Important to this effort was the involvement of stakeholders in the process, which include professors and research staff, but also building and grounds staff who understand how the buildings function, particularly the cooling systems.

In the end, a variety of conservation measures were chosen from removal of unnecessary turf grass and installation of weather-based irrigation controllers as outdoor measures to upgrading most bathrooms on campus and replacing one-pass sterilizing equipment, to real-time metering to provide feedback on water use, and especially on leaks.

In the same vein as Stanford University, a case study from the EPA found a wide range of possible upgrades for a hospital in Olympia, Washington, to decrease water use. These water conservation measures concentrated on:

Upgrading sterilizer equipment
Recovering condensate from the sterilizer for re-use (non-potable use)
Upgrading water-using equipment with non-water using equipment

This process resulted in a savings of 5.9 million gallons once the retrofits were completed and a cost savings of $140,000 per year. So while it may seem like the CII sector is technical, case studies such as this one illustrate that by identifying the high-water using appliances and equipment and researching upgrades, there is a significant potential for water savings.

Try It!

Where is most water used in a restaurant? Where is most water used in a school?
College of the Canyons is considered an “institutional customer.” Where might the greatest water savings lie?