City of Phoenix's Aquifer Storage and Recovery (ASR) Well Program: From Concept To Operations

Gin, Gary M.

The capacity of Phoenix’s groundwater supply infrastructure has declined due to the disconnection and/or abandonment of wells related to water quality issues and aging equipment. Currently, the City’s well system has capacity to meet 5 to 10 percent of peak day demand. The City has identified the need to rebuild and enhance its well system to provide drought redundancy, operating flexibility, emergency capacity; and to manage the variable nature of its surface water supplies. It is anticipated that the short-term groundwater needs for operating flexibility and system emergencies are more compelling than the longer term needs to offset drought and climate change impacts. The City’s objectives are to expand well capacity to meet 15-20% water demands, manage its aquifers to ensure the future availability of good quality groundwater, and to reduce the risks of land subsidence and other adverse environmental impacts. To meet these objectives, the City is developing an ASR well program. Phoenix has identified three critical elements to define sustainability for its ASR well system; 1) cost-effective and efficient, 2) operator and manager friendly; and 3) commitment from all levels of the Water Services department to successfully implement this program. To meet these objectives, we had to demonstrate economic benefits to upper management and concurrently time train/educate operators on how an ASR well system works within the existing potable distribution system. Through the course of design and construction of the first ASR well system, we realized that innovative technology would provide the necessary success from both an economic and operations perspective. Sophisticated programming logic control at the ASR well allowed us to accomplish the following:

Simplify the operator functions and data collection;
Successfully unclog the well with the permanent pump after successive recharge seasons;
Reduce labor force in operating the well system; and
Access real-time performance data so that decisions can be made quickly.