(from http://news.pollutiononline.com/case-studies/cs060597.html):

Chandler, a city in the Sonoran desert averages seven inches of annual rainfall and relies on groundwater for more than 50 percent of its potable water. The state of its water resources almost cost it the opportunity to attract the Intel Fab 12 microelectronics manufacturing plant, one of the largest microchip-processing facilities in the world. Chandler's predicament was that Microchip manufacturing is a water-intensive process and the city couldn't overdraft precious groundwater.

Also problematic was the overburden the plant would put on the wastewater-treatment infrastructure. Chandler's only option for attracting and serving Intel Fab 12 was to build the IPWTF, a 2.3-MGD, city-operated centerpiece. The IPWTF purifies wastewater from Fab 12, then injects it into the groundwater supply, recharging up to 90 percent of Fab 12's usage.

The IPWTF is one of the first facilities in the U.S. to use reverse osmosis (RO) to reclaim industrial process water, treating it to potable standards. (RO has been successfully used for treating drinking water but has not been widely used in industrial reclamation, particularly on a large scale.) Fab 12's wastewater is segregated in two process streams with different membrane types used for each. The first process stream,"RO100," is high in fluoride and uses conventional, high-pressure thin-film composite membranes. The membranes reduce the wastewater feed fluoride concentration from in excess of 15 mg/L to much less than the 4.0 mg/L required by SDWA regulations. The second system, "RO200," is equipped with nanofiltration membranes and uses significantly lower operating pressures, keeping energy costs low.