GROUNDWATER RESIDENCE TIMES IN THE BRYCE CANYON AREA, GARFIELD COUNTY, UTAH
Our results indicate that groundwater in the Bryce Canyon area aquifers is a mixture of modern (recharged since 1950) and old (recharged several thousand years ago) components. The region has three primary aquifers: a shallow valley-fill aquifer, the limestone of the Eocene Claron Formation, and a Cretaceous sandstone aquifer. Water from the valley-fill aquifer, including the BCNP well field, as well as water from the four springs sampled, which all discharge from the Claron, consists of modern groundwater recharged since or just prior to 1950. By contrast, water from wells completed in the Cretaceous aquifer consists of old groundwater, recharged at least several thousand years ago. Groundwater from the valley fill and Claron Formation generally has lower total-dissolved-solids concentrations than groundwater from the Cretaceous aquifer. The presence of modern groundwater in most wells and springs suggests these aquifers are actively recharged and thus sensitive to climate change, as well as susceptible to surface-based contamination sources. Careful land-use planning and resource management is warranted to preserve groundwater resources in the Bryce Canyon area.