This project was the first, new construction, rainwater harvesting system in the City of Knoxville approved for indoor-potable use.
The home is located on top of a ridge in the Fort Loudon Lake watershed and receives an average annual rainfall of 50 inches. Rainwater Resources™ worked with the home owner and architect to integrate a system design specific for the application and site topography.
The homeowner had three primary goals: One, improved water quality; he wanted soft water and was very attracted to the idea of having it without the maintenance requirements of adding salt. Two, improved water pressure; due to his location on top of a hill municipal water pressure was quite low upon reaching his house. And three, the ability to have a future independent water supply which would allow him to operate off the grid.
The system consists of three 1,700 gallon, below ground, storage tanks. The 4,000 square foot roof of the two-story brick home will supply about 112,000 gallons of water per year.
Conveyance was routed, underground, from each downspout and joined together prior to entering the Wisy™ vortex filter for first-flush and pre-storage filtration. The rainwater is introduced into the main tank through a smoothing inlet. Water is stored in the three, 1,700 gallon underground Snyder tanks.
Water is pressurized to the house using a Gould submersible pump. Immediately after the water enters the home it is sent through high quality sediment and carbon filtration before entering the Ultra Violet (UV) disinfecting system. The UV system includes a lamp-out solenoid which will automatically shut off the water should a lamp outage, or other error, occur on the disinfecting system.
The system includes a liquid level indicator, installed in the kitchen, to relay tank water level information to the homeowner. The job was also engineered with an automated municipal water crossover controlled by a float switch inside the tank. Should a dry period continue, and the tanks empty, the system will automatically, and seamlessly, switch to the municipal water to supply the household distribution system.