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Last week contractors began pushing dirt to start construction on a Sanitary District project to upgrade two of its aquifer storage and recharge wells at Fountain Park, and at the same time build two new public restrooms for the park.

The discussion of this project may also raise the question as to what, exactly, are recharge storage wells.

In earlier years Fountain Hills had something of a “love/hate” relationship with the reuse and disposal of its treated wastewater. There tended to be too much in the winter and too little in the summer, when it was needed for irrigation.

There was a time when, on a cold winter morning, icicles would hang from vegetation in remote areas where the district was discharging effluent using sprinklers. As the town continued to grow there became a situation where more effluent was being created, but the discharge fields were shrinking due to development.

At one point state officials threatened a building moratorium on the town unless it could find a more balanced way to manage the effluent.

That is where the recharge wells come into play. There are five of them; three in Fountain Park including the two about to be upgraded, one is adjacent to the district’s advanced wastewater treatment plant off Kiwanis Drive and the fifth is at the rear of the Community Center in the civic complex.

Sanitary District Manager Dana Trompke explains the situation rather simply. The homes within the district generate more waste water to treat during the winter months when there are more people here, but the cooler and wetter conditions of the season mean there is less need for irrigation water.

During the summer months, when there is less water going into the system, there is a greater need for water for golf course and park irrigation.

The solution is the system that allows the surplus treated wastewater generated during the winter to be stored underground to be drawn back out for use in the summer months.

There is an aquifer that lies 700 to 900 feet below Fountain Park and the downtown that allows for the storage of a “bubble” of up to 720 million gallons of water (that is more than seven times the water in Fountain Lake).

The recharge wells pump water into the ground during winter when there is less demand for it, and it is pumped back out when it is needed in summer.

There is little to no impact to the ground water aquifer in the vicinity, Trompke said.

To safely store water below ground, the Sanitary District constructed its sophisticated membrane filtration facility to provide further treatment (the advanced wastewater treatment plant).

The water pumped into the ground is treated to the state’s highest designation for reclaimed water, Class A+. When it is pulled out there is almost no difference in the water from when it was pumped in, according to Trompke. It is somewhat more alkaline, but that is absorbed from the desert soil.

The wells and treatment facilities have been operating successfully since 2001.