Dear VA DEQ,

Thank you for this public comment opportunity. While there are many concerns around a proposal for allowing local variances in air quality, here are three significant issues that warrant much greater investigation prior to VA DEQ considering local air quality variances:

The first issue is the lack of sufficient historical and current air quality data upon which to base an informed decision. For example, if you review the “Virginia Ambient Air Monitoring 2021 Annual Report” (accessed at https://www.deq.virginia.gov/air/air-quality-monitoring-assessments/air-quality-reports) it provides data on nine different criteria pollutants – but this data is reported only for a handful of sites within your statewide monitoring network. The available data is too sparse and insufficient to establish a reliable baseline of local-level air quality in the neighborhoods, schools, parks and other locations adjacent to/nearby data centers.  Even 3^rd-party air quality mapping sites such as https://aqicn.org/city/usa/virginia/ do not provide the data resolution needed by Virginia residents to fully understand their current air quality.

The second issue concerns the breadth of potential air quality impacts across Loudoun, Prince William and Fairfax Counties given the number of data centers located in these counties.  (e.g., see https://www.datacentermap.com/usa/virginia/map.html)  If the local air quality variances are granted and applied to all of the data centers in these three counties:

1. How many data centers are under consideration?
2. How many and what type/size of emergency diesel generators will be operated?
3. What is the predicted air quality impact of the emissions from these emergency diesel generators if they’re allowed to operate 24/7 for up to 5 months?
4. Given the low resolution of Virginia’s existing air quality network, will the VA DEQ be expanding its air quality network to actively monitor local-level locations subjected to these additional emissions?
5. If the local variances are granted, will VA DEQ also establish an upper limit for the different criteria pollutants, such that, if the pollutant limit is breached then the responsible data center(s) will lose their qualification for further emergency diesel generator operation until such time that the generator(s) emissions are remediated and again within allowable limits?

The third issue concerns noise pollution.  Although VA DEQ has historically viewed noise pollution as an issue for local jurisdictions, as the state agency authorizing emergency diesel generator operation through local air quality variances, then VA DEQ should also monitor and be ready to address all potential negative impacts resulting from their decisions.  Local jurisdictions aren’t resourced for the likely wide-scale, deleterious noise impacts resulting from 24/7 emergency diesel generator operations.  The VA DEQ needs to develop and implement a noise control plan in conjunction with any local air quality variances that it authorizes.

Thank you!