Summary of basic hydrologic data collected at Coso Hot Springs, Inyo County, California

More than 200 wells and springs were visited within a 20-mile radius of Coso Hot Springs, Calif. Hydrologic and geothermal data were collected for each well or spring site. The data includes depth, chemical quality, temperature and specific conductance of water, quantity of flow, well construction, and well logs. These data show that the normal temperature gradient in the ground is about 1.1 degrees Celsius (2 degrees Fahrenheit) per 100 feet. The temperature gradient in the thermal areas is as high as 24.4 degrees Celsius (44 degrees Fahrenheit) per 100 feet. The highest temperature measured for all the wells and springs was 142.2 degrees Celsius (288 degrees Fahrenheit). The chemical quality of water in the study area is generally good except in areas where water evaporates from land surface at Owens Valley playa or where steam escapes into the atmosphere from land surface. Computerized hydrologic and geothermal data are being stored for future use at the U.S. Geological Survey office, Laguna Niguel, Calif. (Woodard-USGS)