Orange County agencies set to launch hunt for new source of tap water

The water, which is slightly red, seeps into the aquifer naturally, so getting to it probably won’t require any construction or energy-intensive pumping. Also, brackish water already is segregated within the aquifer through a series of liquid barriers known as “injection wells.”

What’s more, its primary contaminant – salt – is already removed from at least some of the county’s drinking water supply. The process of doing that is based on pressurization; essentially squeezing the salt out of the water.

So, when it comes to the brackish water, the basic question comes down to how much salt it has. Removing a lot of it would require a lot of pressure and, as a result of that, a lot of energy. Less salt would mean less of everything else.

“It’s probably more energy intensive than pumping out groundwater,” said Andrew Wiesner, an engineer for Mesa Water. “But compared with seawater, it’s significantly less energy intensive.”

Salinity is one of dozens of questions to be determined during the study – known as the local groundwater Supply Improvement Project (Local SIP) — which now is slated to begin in August.

Mesa officials said the technical side of the idea will be looked at by geologists and water experts and engineers. Other experts will look at long-term cost projections and the area’s potential need for water.

When the first phase of Local SIP is finished, probably in April of next year, Shoenberger said the group will have three options.

“We could do nothing. We could choose to (extend) the study. Or we could go whole hog and get started.”

Issues such as cost, long-term financing and pricing are not yet known, Shoenberger said.

Future need also isn’t clear. The county’s population currently is a bit over 3.2 million. By 2050, according to a projection from the Orange County Water District, the county’s population will grow to about 3.3 million.

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