"The utility is also hoping to eventually sell access to its sewer system, so buildings can reroute air flow to use the sewer's natural heat and lower heating and cooling costs. Crews are already installing a test system during a renovation of the American Geophysical Union building on Florida Avenue in Northwest. It's part of the design to create the first net zero energy building in the District." NBC Washington https://www.nbcwashington.com/news/local/DC-Water-Tries-to-Lower-Customers-Bills-by-Marketing-Inventions-466865913.html
