By John T. M. Lyles
Edgewood Caverns is a densely jointed cave in Santa Fe County that has a single 38 m deep entrance shaft, drilled and cased with a 0.5 m diameter steel pipe. The cave is in Pennsylvanian limestone and was phreatic in development with solution-enlarged joints. It is a substantial cave, having been mapped ~8.3 km (5.2 mi) as of 2019, and has barometric-driven winds at the entrance cap. A detailed talk on the history of the cave was given in the Conservation session at the 2018 NSS Convention. The Estancia basin in New Mexico is geologically known to source CO2, measured in water wells and in the cave. Levels as high as 2% have been measured in the deepest passages during low-pressure weather events. The author, who owns the land overlying the entrance, has developed a system using a commercial CO2 sensor that will be placed in the cave. It will use an adjacent abandoned water well for cables to bring the signals to the surface and also to power the sensor with a solar-charged battery. A commercial sensor gateway will be incorporated on the surface to upload regular updates to a server via LTE (cellular data service). With knowledge of the cave CO2 conditions before descending the entrance shaft, and carrying portable gas meters, exploration of the cave will safely continue in the future.