Dear Mr. Faggert,
Currently, Virginia regulations allow data centers to use older diesel generators (Tier II) only during “sudden and reasonably unforeseeable” emergencies. The new guidance proposed by DEQ (Dec 2025/Jan 2026) seeks to redefine “emergency” to include "planned outages" or grid stress events. Essentially, this would allow data centers to fire up thousands of diesel generators simultaneously during heatwaves or peak load times to relieve pressure on the grid, without being required to install the modern pollution controls (Tier IV) usually required for non-emergency power generation.
To the public, redefining an “emergency” sounds bureaucratic. Biologically and physically, it represents a significant shift in exposure risk. By classifying grid capacity issues as "emergencies," facilities can bypass Best Available Control Technology (BACT) standards which poses a significant contaminant threat. Tier II generators release significantly higher levels of Nitrogen Oxides (NOx) and Diesel Particulate Matter (DPM) than Tier IV units. Excess grid stress usually occurs during hot, stagnant summer days. Releasing high volumes of NOx during these specific windows acts as a catalyst for ground-level ozone formation, creating air quality events exactly when populations are most vulnerable to heat stress. Combined with the associated industrial-scale noise and land impacts, many experts have designated data centers to be “incompatible” with residential use (JLARC r. 598).
The December 2024 JLARC report outlined how unregulated data center growth will increase energy demand beyond commercial enterprise. To maintain grid reliability, infrastructure costs would drive up residential energy bills upwards of $37 a month ($444 annually), and place a disproportionate economic burden on low-income Virginia families. JLARC’s report mostly considers projections of data center growth from 2024, which have already been exceeded in 2026 by +16% 10-year growth rate; +90% Dominion contracted capacity; +1,038% capacity market price; and +170-220% residential bill impact (PJM 2026, Dominion IRP 2025, SCC-PUR-2024-00144).
We recommend that the Governor’s Office lead DEQ to reject the loosened definition of “emergency” in APG-576. If data centers are to be used as a part of the grid’s reliability strategy (demand response), they would essentially become power plants, and therefore be regulated under mandate Tier-4 controls and real-time monitoring. This would ensure that any generator used for “planned outages” must use selective catalytic reduction (SCR) to remove NOx emission, plan 2-hour battery buffered infrastructure, and establish fenceline air sensors at facilities to alert municipalities when PM2.5 levels spike (PMID: 37584085).
As the Department of Environmental Quality evaluates the revision of DEQ Guidance Memo APG-576/578, it is instructive to consider how other states are pioneering alternative regulatory frameworks to manage the unprecedented resource demands of data centers. Across the country, state legislatures and utility commissions are actively working to protect residential ratepayers from absorbing the massive infrastructure costs and environmental burdens associated with this industry. For example, California recently advanced SB 57 and SB 886 to establish special tariffs and explicitly prevent data centers from shifting infrastructure and transmission costs onto residents and small businesses. Similarly, Indiana (HB 1007) and Ohio (PUCO 2025) now require large-load AI data centers to cover 80% to 85% of the upfront costs for new, dedicated energy infrastructure and projected electricity usage. Furthermore, Minnesota (HF 16) is tackling physical resource consumption by establishing a distinct utility customer subclass for facilities consuming over 100 million gallons of water annually, highlighting a growing national consensus on the need for targeted, data-center-specific regulations.
This national momentum is strongly reflected here in Virginia, where the General Assembly is currently weighing nearly 60 bills, like HBs 897 related to data centers—nearly double the volume of the previous session. Key legislation mirrors these nationwide efforts to balance economic growth with grid stability and environmental protection. For instance, HB 897 directly ties state tax exemptions to stringent sustainability standards, explicitly requiring operators to transition away from diesel backup generators to non-carbon-emitting power sources. Additionally, HB 284 mandates comprehensive transparency regarding energy, water usage, and emissions. Integrating these legislative priorities—particularly the shift away from diesel generation and enhanced emissions transparency, which V-SCI wholeheartedly endorses—directly into the framework of the DEQ Guidance Memo APG-576/578 Revision will be critical for ensuring Virginia maintains strong environmental stewardship while managing this rapid industrial expansion.
Respectfully,
The Virginia Scientist-Community Interface (V-SCI)