Both! This is a complex international problem that has been going on for decades. Internationally-owned factories operating in Mexico, many of which are U.S.-based, are contributing to the industrial contamination that crosses the border, and the U.S.-managed International Treatment Plant in San Diego County—meant to protect U.S. residents—has faced years of deferred maintenance due to neglect and lack of funding by the U.S. government. Mexico is almost finished repairing its wastewater treatment plant, and the U.S. has just broken ground on repairs here that are expected to take at least five years to complete. Greater prioritization is needed from both federal governments to address this issue as one of the most egregious public health emergencies in the United States.