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Data Centers and Water Use in Pennsylvania

Data centers are increasing in number and size across Pennsylvania placing increasing demands on the state's water resources.

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Updated:

October 20, 2025

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The proposed site for a 700 acre data center campus in Cumberland County.

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What is a data center?

A data center is a place where networked computers, called servers, and their associated information technology equipment, are located. Many organizations maintain onsite "enterprise" data centers (DCs) to meet their business needs.DCs gradually moved offsite throughout the 2000s and 2010s to meet growing demands for data services created by the spread of the internet, the expansion of e-commerce, and the adoption of cloud-based computing.¹Data centers are now growing dramatically in both number and size as businesses rush to develop artificial intelligence applications.²

How many data centers are there in Pennsylvania?

Although no public agency currently tracks the number of DCs in Pennsylvania, several private firms maintain online listings of commercial facilities that lease server space. Their information indicates Pennsylvania had between 57 and 97 of these DCs as of October 2025.³ These numbers do not include enterprise-scale data centers, which may number in the thousands, but are relatively small and have traditionally used air to cool their servers instead of water; or the hyperscale DCs, which are over 500,000 square feet in size and contain at least 5,000 servers.⁴ According to a website called "Pennsylvania Data Center Proposal Map and Data," there were 21 hyperscale DCs in the planning stages based on published news, press releases, and company websites as of late October 2025.⁵

How do data centers use water?

It's not obvious, but DCs can use significant amounts of water compared to other common water use activities in Pennsylvania. Water use happens both directly and indirectly. The main direct water use happens when DCs use evaporative cooling equipment to remove the heat that is generated by their computer processing chips which operate poorly when they get too warm. The main indirect water use – which is not always reported when DCs release information about their energy and water use – happens when power plants supply DCs with electricity.⁶ Except for renewable power providers, most power plants that use fossil or nuclear fuel to heat water for thermoelectric generation rely at least partially on evaporative cooling.

DCs use water in other ways that are frequently overlooked. In dry climates, probably including Pennsylvania during the cold winter months, DCs directly use water to humidify their server rooms to prevent the buildup of static electricity.⁷ Additional indirect water use can be attributed to the energy it takes to supply DCs with clean cooling water and to later remove mineral buildup in this water at a wastewater treatment facility after it has gone through several cooling cycles.⁸ Finally, it takes substantial water to manufacture computer chips, but this manufacturing process does not directly impact Pennsylvania's water supply since it happens outside the state.⁹

How much water do data centers use?

Information on how much water individual DCs use is hard to come by for several reasons, including: DC are typically not required to report this information; energy providers do not readily share customer data on electricity use which could be used to estimate water use; water use can differ significantly between data centers due to a wide variety of factors, such as geographic location (DCs in temperate or cool climate like Pennsylvania may require relatively less energy and water for cooling) or energy source (renewable energy can lowers water use); and if water use numbers are provided they often leave out indirect water use.

Google’s annual environmental report includes onsite water use information for the large DCs they operate.¹⁰ Table 1, reproduced from the report, shows water use information for several of the DCs located near Pennsylvania.

Table 1. Direct water use by several large Google data centers near Pennsylvania
Data Center Name & Location*	Year 2024 Water Withdrawal (gallons per year)	Year 2024 Water Consumed (gallons per year)	Year 2024 Water Discharged (gallons per year)
Ashburn, VA	59,500,000	56,000,000	3,500,000
Bristow, VA	105,700,000	84,400,000	21,300,000
Sterling, VA	201,200,000	158,200,000	43,000,000
New Albany, OH	405,300,000	352,700,000	52,600,000

*Google does not release size data for all its DCs but does reveal their facility in New Albany, Ohio is 275,000 square feet.

In Table 1, the term water withdrawal refers to the water extracted from surface or groundwater resources. Water consumed refers to the portion of this water that is lost to the atmosphere due to the evaporation that occurs in liquid cooling units and humidification of the DC. Water discharged refers to water that is released into local waterways after treatment to remove natural minerals that commonly become concentrated in water that has recirculated multiple times through evaporative cooling loops.

The water withdrawal numbers in Table 1 only account for the direct component of a DC's water footprint. They leave out the indirect components — primarily linked to power generation — which may be significantly larger, depending on the energy source.¹¹

What is Water Use Effectiveness?

Water use effectiveness (WUE) is the ratio between a DC's water consumption and the amount of energy they use over a given time period.¹² The calculation is:

WUE= Onsite water consumption (liters)/Energy used by data equipment (kilowatt hours)

WUE is useful for comparing water use efficiencies between DCs and also provides a benchmark that DCs can monitor to identify problems with their cooling systems. DCs can strive to lower their WUE number, but this approach has tradeoffs. Using air cooling in a DC, for example, may seem to be a good idea because it could reduce the facility's need for water cooling, which would lower its WUE. But air cooling requires additional electricity because it's less efficient at heat removal than evaporative water cooling. By increasing electrical demand, the DC may also increase its indirect water use if it gets power from utilities that use evaporative cooling.¹³ Utilities that deliver power to DCs can also use WUE to monitor their water efficiency, and DCs should consider selecting utilities with low WUE ratios to reduce their indirect water consumption. An industry website reports that 1.8 L/kWh is the average WUE for DCs in the United States, although the research behind this number is not clear.¹⁴ Microsoft reports WUEs of 0.18 in 2024 for the DCs they operate in Virginia.¹⁵ The company Equinix reports 1.63 for its DCs that use evaporative cooling. It is not clear if Microsoft or Equinix are measuring WUE the same way.¹⁶

Where do data centers get their water?

DCs get most of their direct cooling water from municipal water suppliers, which are the same water utilities that also provide water to residential customers. Other sources may occasionally include groundwater, reclaimed wastewater, and captured rainwater.¹⁷

How does data center water use compare to other water use activities in Pennsylvania?

The evaporative water loss for the four data centers listed in Table 1 is 446,000 gallons per day, which is approximately equal to the amount of water 5,439 Americans use on a daily basis based on numbers from EPA.¹⁸ Some resources indicate future AI-driven hyperscale data centers in Pennsylvania could use as much as 5 million gallons per day, which would be equal to the daily water consumption of 61,000 people, a population roughly the size of the City of Harrisburg and surrounding townships.¹⁹

Table 2 presents water use statistics for what are currently the major water use sectors in the state. While it's unclear if future data centers in Pennsylvania will withdrawal 5 million gallons of water per day (Equal to 1.8 billion gallons per year), and how much water state DCs currently use, it is increasingly clear that DCs may rapidly become one of the state's largest water use sectors.

Table 2. Major water use withdrawals in Pennsylvania in 2020.
Major Water Using Sectors	Total Withdrawal in gallons per day (gpd)	Total Withdrawal in gallons per year (gpy)	Percentage
Thermoelectric Power Generation	3,190,425,225	1,164,505,207,125	61%
Public Water Supply	1,330,820,296	485,749,408,040	25%
Industrial Manufacturing	508,627,063	185,648,877,995	10%
Livestock and Aquaculture	105,802,351	38,617,858,115	2%
Mining	53,340,787	19,469,387,255	1%
Wastewater Collection and Treatment	13,836,877	5,050,460,105	>1%
Oil and Gas	10,187,450	3,718,419,250	>1%
Commercial and Institutional	8,488,037	3,098,133,505	>1%
Irrigation	5,708,687	2,083,670,755	>1%
Total	5,227,236,773	1,907,941,422,145	100%