Water and Sewer Utilities

Data centers generate massive amounts of heat. As a result they need millions of gallons of water annually for cooling. Depending on the type of cooling system, some of this water may be recirculated, some evaporates, and some is eventually discharged offsite. If your data center is not using very much water, ask what it is using for cooling instead; it might be relying on more power for fans (i.e. more electricity) or chemical coolants.

As a result, these facilities often need permits to withdraw water for use, discharge it into waterbodies or wastewater treatment systems, manage stormwater from roads, buildings, and other impervious surfaces, and for any impacts to wetlands. The federal and state environmental laws that apply to these permits often require review processes that developers can’t skip. Most water issues are addressed at regional, state, or local levels.

In the arid western US, data centers need to purchase water rights in order to draw surface or groundwater. As long-term drought takes hold in the west, the oldest water rights have, in theory, top priority, making them an attractive target for data center water purchases. This could include tribes, farmers, or municipal users. You can keep an eye on this by finding out who has senior water rights in your watershed and keeping tabs on who is buying and selling or “renting.”

Data centers generally prefer to draw water from a water treatment facility and negotiating the amount can be a powerful leverage point for communities. Even if water is available, new or expanded infrastructure may be needed to get it to the facility. Water discharged from data centers generally requires a state permit that is based on federal discharge standards, which are not designed for pollution coming from data center sites. In addition, water discharged during construction, which might include runoff from the site and system “flushing,” is not always covered by operating permits and could be a significant short-term source of chemicals and suspended solids.

Water discharged from data centers can have high concentrations of pollutants like biocides (which are very commonly used to prevent algae from growing in the cooling system), corrosion inhibitors, and dissolved solids (which build up from repeated evaporation). The water can also be warm or hot (thermal pollution), elevating stream water temperatures beyond their threshold for their native species. Traditional water treatment plants are not designed to treat large volumes of water with these types of contaminants, so the pollution easily moves through the treatment plant and is discharged into the environment where it can pose risks for wildlife and downstream water users. Managing additions of warm water and biocides can also add costs and time to the water treatment process, because it often relies on biological communities of “bugs” that work best within a specific temperature range and that may be vulnerable themselves to biocides.

Construction of roads and buildings and surface runoff from parking lots can impair or destroy wetlands, triggering the need for permits to mitigate the impacts. Sometimes this habitat loss impacts threatened or endangered species, requiring additional reviews and permits.

Environmental reviews for water use, water discharge, wetland impacts, and endangered species habitats create public participation opportunities. Agencies must respond to substantive comments, and weak environmental analysis can be challenged through appeals and lawsuits. Threats to locally important resources can generate strong opposition.

This gateway matters because developers want quick approvals with minimal conditions and limited public disclosure. Since each site has unique power availability, timeline, and site-specific conditions, developers may not know the actual water needs and likely pollution levels until fairly late in the design process. Communities can raise concerns about the amount of water used, understanding how much and what happens to it, how it’s chemically and thermally changed within the facility, the costs of treating and discharging it, the impacts of discharges, and habitat and species loss. Communities can also highlight how developers’ stories about water needs change and are therefore potentially unreliable. These messages can be shared in public meetings, through written comments on proposed permits, and by getting the message out through traditional and social media channels. Partners may include scientists, hydrologists, engineers, farmers, recreational water users, environmental justice and community groups, hunting and fishing organizations, birdwatchers, and habitat conservationists.

When state environmental agencies and water and sewer authorities see organized community opposition backed by scientific evidence, they’re normally forced to take a harder look.