A meta-analysis of historic groundwater chlorinated hydrocarbon plume data from approximately 17,000 monitoring wells across California, represented in the state’s publically-accessible Groundwater Monitoring and Assessment (GAMA) database, was conducted with the assistance of a machine learning approach, density (DBSCAN), that divided the data into individual sites and plumes. The python 2.7 script used to extract and process the data can be found at https://github.com/NumericalEnvironmental/VOC_Plume_Meta-analysis_with_Python.