Data Centers Move to Cut Water Waste

coolingtower-googleAs data centers get larger, they are getting thirstier as well. The enormous volume of water required to cool high-density cloud computing server farms is making water management a growing priority for data center operators. A 15-megawatt data center can use up to 360,000 gallons of water a day, according to James Hamilton, a data center designer and researcher at

“Water is tomorrow’s big problem,” Hamilton said. “No one talks about water. The water consumption (in data centers) is super embarrassing. It just doesn’t feel responsible. We need designs that stop using water.”

Some large data centers, like Switch Communications’ SuperNAP in Las Vegas, have implemented direct expansion cooling systems designed to use lower amounts of water. Microsoft and Google are trying new approaches that use recycled water and nearby rivers and canals to cool their massive data centers, which is influencing where these facilities are located.

Microsoft says it picked San Antonio for one of its new data centers because the local water company could provide large amounts of recycled water, meaning the project would have less impact on the city’s drinking water supply. Google’s new data center in Belgium is located next to an industrial canal for cooling, while other providers are incorporating wells and captured rain water into their cooling systems.

Role of Cooling Towers
Why worry so much about water? The move to cloud computing is concentrating enormous computing power in mega-data centers containing hundreds of thousands of servers. All the heat from those servers is managed through cooling towers, where hot waste water from the data center is cooled, with the heat being removed through evaporation. Most of the water that remains is returned to the data center cooling system, while some is drained out of the system to remove any sediment, a process known as blowdown.

When this process is played out at mega-data center scale, the amount of water required for cooling can be enormous, sometimes exceeding the capacity of local utilities.

Impact on Local Water Systems
Last year the city of Northlake, Ill. expanded its water capacity to support Microsoft’s massive new data center in town. In August 2008, the neighboring city of Franklin Park agreed to sell up to 2 million gallons of water capacity to Northlake in an intergovernmental agreement. The cost of the deal, as well as Northlake’s $8 million investment in pumps and a generator, will be paid for by water sales to Microsoft, which has not yet completed construction on the facility. 

These cooling systems don’t require potable water, which was a key point in Microsoft’s San Antonio facility. “One of the unique features of the San Antonio area is their great recycled water systems,” said Debra Chrapaty, Microsoft’s corporate vice president for Global Foundation Services. “As part of our commitment to the environment, we’re using approximately 8 million gallons of water (per month) from this system for our data center cooling needs.”

Recycled or “grey” water isn’t fresh or drinkable but is not contaminated by any toxic substances or toilet wastes. Grey water is considered environmentally friendly because it reduces demands for fresh water and doesn’t consume the energy required to purify it at waste water treatment sites. The San Antonio Water System has been offering recycled water to its industrial customers since 1996.

Another strategy to lessen the impact of data centers on local water utilities is to  your own water supply, either by tapping nearby bodies of water or collecting rainwater.  

Google’s Belgium Project
Google is using water from a nearby industrial canal to cool its data center in Ghislain, Belgium. The company has built a 20,000 square foot water treatment plant to prepare the canal water for use in its nearby data center. 

Google’s approach may not work for everyone, according to Ramzi Namek of Fortress International Group, who gave a presentation on water conservation at last fall’s Data Center World conference. Namek noted that using surface water from canals, lakes or rivers often requires negotiations with local jurisdictions and the EPA, particularly if hot waste water is being returned to the environment. Permitting and negotiations in these scenarios often move slowly, which may affect the project timetable.

“Look at creating a basin next to your facility that you can use,” to collect water,” Namek said. “In some cases, you can use concrete basin tanks, or install large tanks under the parking lot and can collect water from the lot.”

Wells, New Equipment Also Help
Or you can drill a well. That’s the path chosen by credit data service Experian, which dug a 1,200 foot deep well to secure a water supply for its Dallas-area data center. The well lessens the facility’s reliance on the local water utility, but was driven by self-interest as much as conservation. The move was prompted by an incident in which its main water line broke, forcing the company to use deliveries from water trucks to keep its data center online. 

Some companies use a blowdown reclamation system to recycle water from their cooling tower. Investing in new cooling towers can save conserve water and money, Namek said.  “If you have a cooling tower that 30 years old, a new tower is better,” he said. “Invest in a water treatment and filtration system to take solids out of the blow down. You can use a managed magnetic pulse inside the cooling tower to dissolve solids and filter them out.” See Building Green for more information on methods to keep cooling towers free from deposits that can reduce itheir efficiency.

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About the Author

Rich Miller is the founder and editor at large of Data Center Knowledge, and has been reporting on the data center sector since 2000. He has tracked the growing impact of high-density computing on the power and cooling of data centers, and the resulting push for improved energy efficiency in these facilities.

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  1. Rich, This is an excellent point regarding water consumption and data centers. One thing to keep in mind as the data center world moves more toward air side economization is that evaporative cooling systems when properly designed and applied actually have a smaller hydro footprint when the off site water usage is taken into consideration. If you would like some hard data feel free to send me an email and I can get that to you. It might make for a helpful educational piece for your readers. Thank you for your excellent work on your blog. Harold Simmons

  2. These people should look at the Deep Lake Water Cooling System used in Toronto. Basically, a private-public consortium built a system where they interface with heat-exchangers on the incoming city water supply and it's used as the heat-dumping system for many buildings downtown, including 151 Front Street, the centre of telecommunications in Canada. (The usual systems use evaporation of water to dump heat, a home a/c system just uses the outside air to dump heat) So, it's a district cooling system that has the nice side effect of not warming up the lake, but rather warming up the city water by a slight amount. This water usage problem for air conditioning applies to most large buildings, it really isn't data-centre specific. But the nice thing is that some of the proposed systems are more electrically efficient and therefore don't require as large a generator buildout, so the savings can be magnified.

  3. Thank you very much for your honest and informative article regarding the role new and old data centers play in the use of water in our country today!

  4. Mark

    We have a system that can increase the cycles in a cooling tower and uses the atmosphere to do it. In any exisitng facility with a cooling tower, our inexpesnive system plugs in sidestream cnd continually manufactures hydrogen peroxide. The mixture is then hit with a UV light to keep the scaling ions and bio-growth in check. The elevated calcium levels prevent corrosion as well. Additionaly, when the system blows down the hydrogen peroxide will return to Water and Oxygen over time. This system has the ability to reduce the need for make-up water and limits blowdown to a very high degree. It can reduce system consumption dramatically. If you are interested, please email me at mskarulis [at] yahoo [dot] com Thanks, Mark

  5. Thanks for bringing this up again. I have recently been giving presentations on this very subject, including weighing the benefits of the local areas and municipalities. What seems to be missing is mention of zero-blowdown technologies that are becoming more and more viable as they become more efficient and reliable (and not decay equipment).

  6. I know this isn't exactly related but what has been done to protect cooling towers from damage (tornado)? Any thoughts or suggestions would be appreciated.

  7. Roy Carroll

    I'm working with a local municipality to develop a data center park that borders 2 mile of river frontage. Does anyone have knowledge of using river water in conjunction with a heat exchanger to reduce water consumption?

  8. Great. We manufacture cooling towers. Regularly we are using water. This recycle method of Data Centers move to cut water waste is really use full for our clients. Here after we will introduce our client about the data centers to avoid water waste while using cooling towers

  9. Potemkine!

    MW of thermal energy are dissipated with cooling towers, one could say lost by cooling towers. There should be a better way to use this energy.

  10. To Whom it May Concern, I am an artist currently working on a series about some of the youtube videos posted in regards to the catastrophic Japanese tsunami of 2011. I greatly appreciate the conversations in this thread and I would like to pose a question very specific to what I am trying to accomplish in hopes that someone here might have some insight: Approximately how much water is required to cool a server playing one youtube video (approximately 50 mb) just once? I know that this is a ridiculous question in some sense because no server houses only one 50mb video and the amount of water used to cool this would be diminutive. Perhaps it would be more logical to ask how much water it might take to cool a day's worth of plays (let's say about 1000) and then go from there. Once again, thanks in advance for your thought. I am very interested in showing the difference between controlled and uncontrolled water, between human resistance and fatalism, between representation and physicality and would therefore be extremely grateful if someone could help me out in my research on this issue. Thank you immensely.

  11. This is great IT news for us. Let's be environmentally sustainable.