Featured Innovation: Finding Water, Saving Energy

The North Alamo Water Supply Corporation serves 180,000 residents in the Rio Grande Valley.

To keep up with demand that’s expected to more than double over the next 50 years, NAWSC sought to increase the amount of potable water produced through its brackish groundwater desalination plants while also reducing costs.

A Freese and Nichols study of energy-efficient alternatives for removing salt from brackish groundwater found that NAWSC could achieve its goals — and still produce safe drinking water — by replacing reverse osmosis membranes with nanofiltration membranes.

An indepth evaluation of two of NAWSC’s desalination plants showed potential energy savings of 50% in the desalination process. Retrofitting and expanding four existing desalination plants using nanofiltration is projected to save $81 per acre-foot across the life cycle, a 16% cost reduction.

The project, funded in part by the U.S. Bureau of Reclamation and Freese and Nichols’ Research and Development fund, helps advance consideration of brackish groundwater to supplement water supplies.

See more innovative projects in our latest Innovation Report.