More Thoughts on the Budget Item 366 #2c

Item 366 #2c also directs DEQ to study groundwater conditions in western Loudoun and Fauquier Counties and report back by December 31, 2026. The key parts are that DEQ must evaluate groundwater levels and quality, assess current and future withdrawals, consider whether a Groundwater Management Area is needed, and recommend any statutory or regulatory changes needed to protect existing residents and commercial users. In plain English, the amendment asks DEQ to decide whether groundwater in those areas is under enough stress to justify stronger state oversight.

The problem is that the language is written around county boundaries, not around the actual groundwater system. The Culpeper Basin does not stop at the Loudoun–Fauquier line. It extends into Prince William County, and the same fractured-rock formations, recharge areas, streams, and groundwater pathways can cross political borders. By naming only Loudoun and Fauquier, Item 366 #2c leaves out a major part of the same hydrogeologic system.

Prince William was left out because the amendment was drafted around political advocacy, not groundwater science. The Loudoun and Fauquier delegations succeeded in getting their counties named, but the Prince William delegation failed to insist that Prince William be included even though the same Culpeper Basin extends into the county. That omission matters. It shows that the delegations involved did not fully understand—or did not adequately account for—the nature of groundwater as a connected, hidden, slow-moving system that crosses county lines.

That political failure creates a serious scientific problem. It will be very difficult to evaluate only the Loudoun and Fauquier portions of the Culpeper Basin while excluding Prince William, because groundwater does not flow according to county lines. In fractured-rock systems, water moves through connected cracks, faults, bedding planes, and weathered zones. One area may serve as a recharge zone, another as a discharge zone, and pumping in one jurisdiction may affect water levels or stream baseflow in another. If Prince William is outside the study area, DEQ may be forced to analyze only part of the system while leaving out a connected portion that could influence the results.

Separating the Culpeper Basin into county-sized pieces is especially difficult because fractured-rock groundwater is already hard to map. Unlike a surface reservoir, the water is hidden underground and moves unevenly through geologic pathways that may not be obvious from the surface. A well in Loudoun or Fauquier may respond differently from a nearby well in Prince William, not because the aquifer is separate, but because the fractures connecting them are complex. Without a basin-wide monitoring network, it is hard to know whether water-level changes are local, regional, seasonal, or caused by withdrawals elsewhere.

The practical consequence is that Item 366 #2c may identify risks in Loudoun and Fauquier while missing or underestimating risks in Prince William. It may also make it harder to determine whether groundwater stress is coming from within the studied counties or from connected development and pumping outside the study boundary. For that reason, the study should be expanded to include the Prince William portion of the Culpeper Basin, or at minimum require DEQ to evaluate the basin as one connected groundwater system rather than three separate political jurisdictions.