This is a critical public health issue and there needs to be real time publicly accessible air quality monitoring to. According to CARB  “Diesel particulate matter (PM) emissions from an average industrial diesel generator (~800 hp), operating at an average load of ~300 kW for 1 hour, is equivalent to driving nearly 660 miles in an average heavy duty diesel truck.” We are talking about 300 diesel generators per data center operating as a stationary source. This could be thousands of diesel generators operating for extended periods of time. DEQ is only asking the Data Center operators notify the DEQ when they are operating their  generators under the order’s provisions and to calculate the air pollution emitted by those generators during those times. The pollution should be measured in real time at the very least and the public notified of an air quality emergency.

Health effects can result from both short-term and long-term exposure to particulate pollution. People most sensitive to particulate pollution include infants and children, the elderly, and people with existing heart and lung disease. The smallest particles can penetrate deepest, causing the greatest harm. Researchers are still trying to identify which types and sources of particles are most hazardous to human health. Particles created from combustion soot tend to be fine particles with diameters smaller than 2.5 microns (PM 2.5) which are the most dangerous because it lodges in the lungs.

The U.S. Environmental Protection Agency, EPA, requires states to monitor air pollution to assess air quality and ensure that they meet minimum air quality standards. The US EPA has established both annual and 24-hour PM2.5 air quality standards (as well as standards for other pollutants). The annual standard established in 2012 is 12 µg/m³ (an AQI of 39). The 24-hr standard remained at 35 µg/m³ (an AQI of 99) and will remain unchanged.

Exceeding the 24 hour standard could cause acute health impacts especially since these data centers are often adjacent to residential communities. There are other air quality rules that might come into play here specifically the Clean Air Non-Road Diesel Rule of 2004.