Data centers use large amounts of water to cool computers and servers. In Virginia, most are permitted to send discharge water to municipal wastewater systems, but at least one Amazon data center in Louisa County is allowed to discharge directly into Northeast Creek, and another has applied to discharge into nearby Sedges Creek, which feeds Lake Anna.
State regulators require pretreatment and set limits for certain metals, pH, chlorine, and temperature. Virginia does not require data centers to test discharge water for per- and polyfluoroalkyl substances, known as PFAS, and neither does the U.S. Environmental Protection Agency. As a result, it is unclear whether PFAS are present in data center discharge.
Amazon said its Louisa County facilities use outside air cooling about 96% of the year and water-based cooling about 4% of the year.
Amazon said the water in its evaporative system is “non-contact cooling water” that does not touch equipment. The company said it dechlorinates the water and manages pH before discharge.
The permit for Amazon’s Northeast Tech Campus allows discharges of up to 460,000 gallons a day into Northeast Creek. Operators must test monthly, and in some cases daily, for residual chlorine, aluminum, cadmium, copper, zinc, hardness, and pH. Water temperature must remain below 90 degrees Fahrenheit.
A draft permit for Amazon’s Lake Anna Tech Park would allow up to 280,000 gallons a day into Sedges Creek under similar standards. According to the Department of Environmental Quality, the permit could be reopened to add PFAS-related requirements.
In response to questions about the Sedges Creek application, the agency listed chemicals used in treatment, including sodium hydroxide, sulfuric acid, sodium bisulfite, polyaluminum chloride, polymer, sulfide-functional polymer, and calcium chloride, and said they are removed during treatment.
