Approaches to Analyzing the Vulnerability of Community Water Systems to Groundwater Contamination in Los Angeles County

Groundwater resources are increasingly drawn on as means to buffer surface water shortages during droughts as well as to improve the Los Angeles region’s reliance on local, rather than imported, water sources. However, the Los Angeles region is home to a legacy of contamination that threatens the quality and safety of groundwater as a drinking water resource. As utilities and other water management entities in the Los Angeles region look to increase their reliance on groundwater resources, a comprehensive understanding of which community water systems may be vulnerable to contamination can help planners, policy makers and regulators support these communities. This paper details the objectives, process and lessons learned from a workshop-based research project that examined the spatial extent of groundwater contamination in Los Angeles County’s groundwater basins. Our team of researchers cleaned and processed multiple geospatial datasets and utilized logistic regression and machine learning methods to predict which community drinking water systems are particularly vulnerable to groundwater contamination.