Purple pipe dreams: How SF’s revolutionary recycled water plan dried up
Thirty-one years ago, supervisors in San Francisco passed a landmark piece of legislation as a signal of the city’s commitment to the environment and conserving water. Any new buildings that were bigger than 40,000 square feet and located in designated zones on the city’s west and east sides would be required to have “purple pipes.” These pipes, which are literally required to be the color purple, would be installed to transport waste to a recycled water plant. … Over the last three decades, San Francisco has seen more than 70 structures go up with dual-plumbing systems that separate potable from recycled water. … But there’s just one problem. … San Francisco never built a recycled water treatment plant for these buildings.