In alignment with the United Nations’ Sixth Sustainable Development Goal, Clean Water and Sanitation, the goal of this system is to help ensure a world where everyone has access to clean and sanitary water. Legionella spp., obstacles to this goal, are waterborne opportunistic pathogens that contaminate drinking water, multiplying in stagnant conditions. This is dangerous because certain Legionella spp. cause a deadly form of pneumonia known as Legionnaires’ disease, as well as Pontiac Fever. To reduce the threat of outbreaks, we have genetically engineered Escherichia coli to have Legionella’s quorum sensing system (LQS), which can detect Legionella by sensing Legionella’s signaling molecule LAI-1. Our system reports with GFP, with luminescence indicating Legionella spp. have been detected in the water. We will transform our E. coli with an engineered plasmid containing GFP and LQS genes—which include auto-inducer synthase (LqsA) and GFP under one promoter, with a sensor kinase (LqsS or LqsT) and a quorum sensing response regulator under another promoter. Then, we will place the E. coli in water with varying concentrations of LAI-1 to simulate Legionella contaminated water.