Water technology companies, spurred by the growing demand for water in California and other drought-afflicted states, are developing innovative tools for conserving and purifying water. CNN recently featured the following three water technology startups, all in Minnesota, developing such new technologies:

Creative Water Solutions uses a type of moss that has anti-bacterial properties to purify water. The moss is used in both residential and commercial settings. In swimming pools and spas, it is packaged into a sleeve near the filter, where its cleaning properties reduce the need for chemicals, remove the chlorine smell out of the water and extend the life of the filtration equipment. In commercial facilities, the moss is lowered in crates into industrial pools, where its cleansing properties allow the water to be reused several times before it has to be disposed of, reducing water usage by an estimated 40 percent. Sales at Creative Water Solutions are growing 30 to 40 percent annually, according to the company’s CEO, and the technology is now used in hundreds of industrial facilities and thousands of residential pools around the country.

Advanced Water Recovery is working to provide a way around the expense of traditional desalination methods. (Cost has historically been the biggest deterrent to drought-ridden regions building desalination plants.) The company’s “dielectric desalination” process uses chemicals to remove the salt from water, then uses a proprietary method of filtering the chemicals back out. The process results in dramatically lower (the company estimates estimates 70 percent lower) operating and capital costs than current desalination technologies.

And Nanostone uses manufactured stone to cleanse water of salt or other pollutants. The special kind of stone that the company uses substitutes for the plastic membranes in traditional water purification technologies. It is much more durable and, because of the distinctive design and special materials used by Nanostone, it is far less expensive than ceramic that has been used before.

These Minnesota companies represent just a few of the thousands of businesses seeking to meet the growing demand for clean water not just in drought-stricken areas like California, but in other regions in which usable water needs are no longer met by natural sources such as rivers, lakes, reservoirs, and underground wells. Receding water tables and groundwater pollution mean that more and more, brackish water, wastewater, seawater, and municipal waste water must be purified in order to meet growing potable water needs. Technologies like the ones we’ve written about here are critical. As the USA Today recently reported, “From nanotech to biotech, a range of companies is leveraging scientific leaps to profit from the preservation of what is unarguably the planet’s most precious resource.”