Horizontal wells have been used in the remediation industry for several decades now and present many advantages over vertical wells, either regarding plume containment or SVE applications. They have not, however, been utilized very often for groundwater replenishment, even though doing so would present many of the same advantages over other forms of groundwater replenishment. The primary benefit of a horizontal injection well (or percolation well, if screened in the vadose zone) is that the screen length is limited by the lateral extent of the receiving hydrostratigraphic unit rather than by the thickness. Horizontal well screens can be several hundreds or even thousands of feet long, providing the option for designed recharge in circumstances that might not be feasible for surface infiltration or vertical applications. Maintaining the well screen in a single unit means the well screen design will more likely be suited for its entire length, as opposed to intersecting multiple units vertically that may exacerbate fines-intrusion ad clogging. The small surface footprint and directional drilling technology means that horizontal wells generally have fewer access issues and more flexibility with the design, allow for a better fit with local geology or optimal replenishment.