In 2021, a synoptic study conducted by the USGS and NPS identified wastewater related contaminants of emerging concern (CECs) in springs downstream of the South Rim wastewater treatment plant. This included several pharmaceuticals and per- and poly-fluoroalkyl substances (PFAS), commonly referred to as "forever chemicals".

This new study proposes to build on the 2021 study with an expanded design that will confirm the occurrence and quantify the magnitude of CECs, characterize the surface-water hydrology in relation to spring water quality, and analyze the potential influence both spatially and temporally within the spring aquatic ecosystem. This includes determining if PFAS is bioaccumulating in aquatic macroinvertebrates.

Grand Canyon National Park (GRCA) is in the planning phase of the new wastewater treatment plant and the information gained through this study will be necessary for management decisions about treatment and discharge locations that will best protect the health of visitors and sensitive aquatic ecosystems.

Project Publications

• Utilizing anthropogenic compounds and geochemical tracers to identify preferential structurally controlled groundwater pathways influencing springs in Grand Canyon National Park, Arizona, USA