On July 7, 2021, the Great Basin Unified Air Pollution Control District issued an Owens Lake Contingency PM10 Control order for a 34-acre area located immediately north of existing dust control area (DCA) T1A-4. LADWP is now required to implement Best Available Control Measures in the 34-acre area within three years of the order date. LADWP is exploring the need to implement dust mitigation measures in areas adjacent to existing dust control areas T1A-4 (120 acres including the ordered area) and T10-3a (26 acres). These areas (designated as T1A-4 Addition and T10-3a Addition) may be contributing to sand deposition in existing control areas resulting in increased maintenance. In order to ensure the quality of the design, a geotechnical field investigation with borings is necessary to collect subsurface data that will identify the soil types in the DCAs. A total of 8 geotechnical exploratory boreholes are proposed at T1A-4, and a total of 4 boreholes at T10-3a Addition. The depth of each borehole will be a maximum of 15 feet, and the diameter of each borehole will be a maximum of 8 inches (typically 4 inches). It is estimated to take 2 to 4 days to complete the field investigation work. A geotechnical engineer or geologist will be on site to work with the drilling crew and observe and log the soils extracted from the boreholes. The area has been recently surveyed for avoidance of any potentially sensitive biological and cultural resources, and a tribal monitor and archaeological monitor will be present during the field activities.