WaterMark
Data Center Water Impact Assessment Tool

Press Brief · Prince George's County, Maryland · May 2026

The water figure missing from the Brightseat data center debate

The proposed 820 MW data center at the former Landover Mall site would use about 17.7 million gallons of water a day. Public discussion has cited only half of that. Every number below links to a primary source.

The one-sentence version

Corporate water disclosures count only the water a data center evaporates for cooling. They leave out the water used to generate its electricity, which on the PJM grid is nearly as large again. For the proposed Brightseat Tech Park project, that omission is the difference between 9.4 and 17.7 million gallons per day.

Direct (cooling) is 9.4 MGD. Indirect (power generation) is 8.3 MGD. The indirect figure is excluded from every corporate "water positive" claim. Counted together, one facility draws about 5.5% of WSSC Water's entire system capacity.

The numbers (820 MW, evaporative cooling, Scope 1 + Scope 2)

MetricValueBasis / source
Total water footprint 17.7 million gal/day Direct + indirect, see below
Direct cooling water (Scope 1) 9.4 million gal/day Evaporative rate, LBNL 2021
Indirect power-generation water (Scope 2) 8.3 million gal/day PJM grid water intensity, EIA-923 + PJM
Share of WSSC system capacity 5.5% Of 170 MGD system, WSSC Water
Household equivalent ~62,000 households At 150 gal/household/day, USGS
Annual electricity demand 7.2 million MWh/yr 820 MW continuous, EIA
Estimated residential rate impact +$12 to $22/month Per PJM household, planning-level estimate

Figures are planning-level estimates for the largest proposed configuration. Change the size, cooling type, or toggle the grid water on and off in the live tool. Full derivation on the methodology page.

Cumulative context

Brightseat is not the only proposal in the watershed. The Interstate Commission on the Potomac River Basin found in March 2026 that data centers already account for 9 to 12% of Potomac summer-peak consumptive use, with demand projected to keep climbing. The single-facility figures above stack on top of existing draw.

Source: ICPRB, Data Centers and Water Use in the Potomac River Basin (March 2026).

What WaterMark is

WaterMark is a free, independent water-impact assessment tool. It estimates direct and indirect water use for proposed data centers at the county level, with an inline primary-source citation on every number. It is a project of Standard Water Corp and is not affiliated with any data center developer, utility, or community group, and takes no position on individual projects. The point is not to oppose data centers. It is to make the full water number visible so siting decisions hold up to scrutiny.

Standard Water Corp
Press and methodology questions: ravi@standardwater.co
Tool: watermark.standardwater.co