We issue air quality permits to data centers to limit air pollution that comes from diesel-powered backup generators. We also keep track of the combined diesel emissions from these generators.
Data centers, sometimes called server farms, house the servers that manage email, store data, and run computer applications. If you shop on the web or bank online, your information is stored at a data center.
Many of Washington's data centers are located in Quincy because the area offers dependable, lower cost electricity.
Quincy diesel pollution monitoring
In 2012, the Pollution Control Hearings Board (PCHB) ordered Microsoft and other data centers to assess the health risks of all sources of diesel particle pollution in Quincy.
The goal of this assessment was to:
- Determine the community locations with the highest exposure to diesel engine emissions.
- Estimate the health risks associated with that exposure.
- Determine the sources that contribute to those risks.
The PCHB also ordered Ecology to review the assessment and use the results to improve future air quality permitting decisions.
In August 2018, the data centers submitted a final health risk assessment using an approved method. However, we identified some technical issues that led to inaccurate results. In our August 2020 report (Español), we:
- Conducted a follow-up analysis.
- Assessed nitrogen dioxide pollution.
- Analyzed recently-available monitoring data.
- Recommended follow-up actions.
Air pollution from data centers
Each data center has many diesel-powered generators that are tested regularly. The air pollution from these generators that is most likely to affect health is diesel exhaust particles and nitrogen dioxide (NO2).
Diesel exhaust is a toxic air pollutant, containing fine particles that can cause health problems for people who are exposed frequently and at high enough levels. These tiny particles are too small for noses and upper respiratory systems to filter out of the air. The particles go deep into the lungs, where they can cause damage and chemical changes.
Nitrogen dioxide (NO2) is another toxic air pollutant that can cause breathing problems when you're exposed for a short time, from 30 minutes to 24 hours. Nitrogen dioxide can make breathing harder for people who already have lung problems, such as asthma. It contributes to acid rain and smog.
When required, a data center must prepare a health impact assessment of their toxic air pollution (diesel exhaust and nitrogen dioxide). Ecology must review each data center's health impact assessment before issuing a notice of construction permit. This permit must be issued before a data center can be built or expanded.
Data centers regulated by Ecology (listed by city)
For information about other data centers in Washington, contact the local clean air agency for that county.