Red River-Green River

GOOD Magazine has a story about a really innovative method for environmental monitoring. The story describes the River Glow project. Architectural firm The Living and Eric Forman (not Eric from That 70's Show).

River Glow is a network of lights floating on the East River that provides quick visual feedback regarding the environmental health of the river. A pH sensor, powered by solar panels, monitors the acidity of the water, causing the lights to glow green when the river is healthy (low acidity) and red when the water is unhealthy (high acidity).