The city of Quincy, Washington is spending millions of dollars to build a system to supply recycled water for huge data centers operated by Microsoft Corp., Yahoo, Intuit and Sabey Corp. The system will allow Quincy to shift the data centers' water requirements to a separate "gray water" system rather than depleting the city's potable water supply.
The water recycling program is similar to one implemented in San Antonio, which Microsoft cited as a key factor in its choice of the city for a $500 million data center. It reflects a trend in which municipalities and data center operators are working to minimize the impact of these facilities on local water systems.
The Quincy project, which will treat up to 5 million gallons of water a day, will cost $9 million. The first phase is being built with a $4.5 million grant from the state, according to the Wenatchee World, which said the city has appealed to federal lawmakers for the rest of the money.
"Data centers use water to cool down," Mayor Jim Hemberry told the paper. "What we’ve decided to do is create this water-recycling facility that will take water from our domestic sewer ... capture that and reuse it."
Hemberry said Quincy saw its sales tax revenues jump from about $800,000 a year in 2006 to more than $4 million in both 2007 and 2008 during the data center construction boom. Microsoft and the other data center companies were attracted to Quincy by the low cost of hydroelectric power from the Columbia River.
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.