When operating under the variance states that data centers would be required to calculate and report to DEQ the air pollution emitted by those generators. Generators powered by natural gas or propane produce lower levels of said air pollution. Modern generators are equipped with advanced emissions control systems, such as diesel particulate filters and selective catalytic reduction (SCR) technology that can significantly reduce their emissions of pollutants such as nitrogen oxides (NOx), particulate matter (PM) and carbon monoxide (CO). Data center backup generators will protect residential customers from outages and ensure the integrity of the internet.