It causes me great concern that DEQ is considering allowing widespread use of large-scale diesel back-up generators by relaxing the definition of "sudden and reasonably unforeseeable events." Northern Virginia has hundreds of data center complexes, many of them located near  residential communities and schools. The rule change would permit use of highly polluting diesel generators in very foreseeable and plannable circumstances. Data centers have been and continue to be approved without coordinated planning for provision of electric power. This proposal would allow them to pollute the air in neighborhoods, playing fields, playgrounds and other areas where many children and health-vulnerable people live and congregate, hurting lung capacity, exacerbating asthma and resulting in long-term health impacts. 

Nor should data center operators be let off the hook from requirements to upgrade to the least polluting generators available. Air pollution permits should require use of Tier IV or higher generators. Poor planning by our state and local governments should not be our health emergency.