Recycled Water ~ Storage Solution
By the early 1980s, recycled water production exceeded its use in the 100-million-gallon Fountain Lake. As the population increased, additional recycled water was produced. Vacant land on the south and west sides of the community were over-seeded with desert grass, which was irrigated with the excess recycled water. By the mid-1990s, land used for temporary irrigation was being removed from service and developed as housing subdivisions. The Fountain Hills Sanitary District (District) needed a solution for its increasing excess water and shrinking available land.
After examining the options, it was decided to construct multiple aquifer storage and recovery (ASR) wells. This allows the District to seasonally store excess water in the ground during the winter, for use by the golf courses and parks in the summer, when the recycled water demand far exceeds the supply. In order to safely store water below ground and not impact the local groundwater aquifer, the District first constructed the Advanced Water Treatment Facility to provide further treatment of the water before recharge and storage. These facilities began operation in February of 2001.
Aquifer Storage & Recovery Wells
The District’s biggest challenge is managing the seasonal differences between recycled water SUPPLY and DEMAND. Recycled water demand far exceeds the supply in the summer months, while supply far exceeds the demand in the winter months. The solution: Treat the recycled water and store the excess underground. The District has constructed and operates five Aquifer Storage and Recovery (ASR) Wells as the means by which to store and recover the excess water, with three of these located in Fountain Park. Currently, the wells store up to 300 million gallons of highly treated recycled water in the winter for irrigation use in the summer at local parks and golf courses.
The wells have been successfully operating for 23 years, which may be the longest of any ASR well operating in Arizona. The longevity of the wells is attributed to first filtering the water by the membrane system, removing all particulate matter, prior to injecting below ground for storage.