A Superfund cleanup site near Sacramento, California, is using solar power to fuel water treatment equipment, and this method has been so successful that the Environmental Protection Agency (EPA) has made the process into a case study. Parts of the 5,900 acre property owned by defense company Aerojet had been designated a Superfund site in 1983 due to pesticides and chemicals seeping into the groundwater. In order to reuse the land, Aerojet partnered with the Sacramento Municipal Utility District (SMUD) and Solar, Inc. to construct a system that would extract the water from the soil and remove toxins before returning it to the ground.

The idea to use solar power came from the fact that Aerojet was attempting to minimize its carbon footprint during the cleanup process, and some of the land adjacent to areas needed to be clean was a large, flat expanse ideal for installing large numbers of solar panels. In exchange for having access to excess power created by the solar panels, SMUD agreed to finance $13 million, over half of the project’s costs.

The solar power for the water pumps and treatment plant occupy 40 acres, and generate six megawatts of electricity. Thus far, the power system has removed and treated 102 billion gallons of water, and the EPA notes that setting up solar panels to power these types of cleanups is less expensive and can be done much more quickly than by installing non-renewable energy plants to accomplish the same task. The EPA has also identified another 14 million acres of land throughout the United States, which could be used for solar energy to assist in cleaning up other Superfund sites.

Even after the process of removing toxins from the Aerojet land is complete, these solar panels will still be useful to the company and to nearby cities, since the panels are fully integrated into the SMUD electrical grid.

Thus far, the EPA has estimated that this solar farm has saved 4,000 tons of carbon dioxide, and three tons each of hazardous nitrogen oxide and sulfur dioxide, which would have been released using a conventional power plant to provide electricity for the cleaning effort.