Polk officials today approved a cooperative funding agreement with the Southwest Florida Water Management District to conduct a pilot study of the technical and financial feasibility of using highly treated sewage as a future source of drinking water.

Polk Utilities Director Tamara Richardson said the pilot study will be completed within two years. She said if the study concludes the conversion is feasible, the source could be tapped within eight to 10 years.

This is among the alternative water sources that may be available to meet expected demand that will outstrip the current use of the Upper Floridan Aquifer.

County and city officials are also studying a plan to tap the lower-quality water in the Lower Floridan Aquifer. That approach will require building something akin to a desalination plant to bring that water to drinking water standards. It will also require the installation of a countywide pipeline system to deliver the treated water to local utilities.

One question the study will answer is whether treating sewage to drinking water standards is cheaper than the well projects, which involve not only well and treatment plant construction and the pipeline, but construction of an even deeper well to get rid of the treatment plant’s brine residue.

The project approved Tuesday would involve water at the county’s Northwest Regional Plant in the Lakeland suburbs. Richardson said the plant produces about 1 million gallons of treated wastewater a day and at the moment is simply discharged rather than being reused to some way to offset the region’s water demand.

Winter Haven officials recently agreed to participate in a similar study partly financed by Swiftmud. The city discharges its treated sewage into the Peace Creek Drainage Canal.