DWCZ - CO - Coal Creek - Soil Collection ICP - (DWCZ-MEF-CC-SoilSample-Transect-AWinkler) - (2022-2023)

Locations: Coal Creek, which serves as the drinking water source for the town of Crested Butte, CO, receives both acid mine and acid rock drainage as a result of legacy mining and fractured porphyry networks, respectively. It has a Koppen climate class of Dfc, aka continental subarctic. Local ecology of the creek varies from site to site, with some parts being far more vegetative than others.

Abstract: Acid mine drainage (AMD) and acid rock drainage (ARD) result in acidic, metal-laden solutions that seep into surface and groundwater systems. The hyporheic zone, where surface and groundwater meet, serves as a natural filtration system, where biogeochemical reactions occur that influence metal retention and transformation. By analyzing changes in metal concentrations and phases throughout time and space, valuable information can be gained in regards to the mechanisms at work within the hyporheic zone. Hyporheic sediment and sediment from planted control soil columns were sampled on a seasonal basis along Coal Creek, an area affected by both AMD and ARD. Samples were analyzed for phase changes via XRD and SEM and sequential extractions created using the samples were analyzed via ICP-OES for elemental fraction concentrations. Preliminary results show the retention and release of metals via redox chemistry. These changes are seasonally dynamic and vary from site to site along the creek, illustrating the capacity of the hyporheic zone to act as a filter for AMD at different points throughout the year.