To determine aquifer characteristics, pneumatic slug tests were performed on selected zones and aquifers at a monitoring site near the North and South Belridge oil fields in the Southern San Joaquin Valley in Kern County. On November 19th and 20th, 2018, pneumatic slug tests were performed at five monitoring wells located at the multiple-well groundwater-monitoring site BWSD (28S/21E-08M1 through –M5) near Lost Hills, CA in the Southern San Joaquin Valley. Data were collected using In-Situ LevelTROLL 500 30psig pressure transducers set to record the depth to water level below land surface at one second intervals. Computations were performed using Aqtesolv software and analyzed using the KGS Model package for overdamped and Butler-Zhan for underdamped slug tests performed in fully and partially penetrating wells in a confined aquifer (Hyder, 1994). Data presented in this data release include well construction information, well development information, observed water levels during the tests, parameters used for analysis, and test results.