The EPA recently finalized its $111-million plan for containing and remediating contaminated ground water beneath the western side of the Aerojet Superfund site outside of Folsom, Calif.

Nine water supply wells have been lost to ground water contamination emanating from the Aerojet Site, and an estimated 13 additional public water supply wells could be lost over the next 25 years if the contaminated ground water is not contained and remediated. The ground water is contaminated with several compounds, including very high levels of perchlorate, a suspected human carcinogen and known developmental toxin.

The EPA evaluated 10 options for addressing the contaminated ground water before deciding on the current plan. The EPA selected its preferred alternative over the next best proposal because it will restore the aquifer in 240 years as opposed to 348 years.

Aerojet-General Corp. says it has been working with the EPA on the plan to clean up ground water contamination from its rocket fuel manufacturing process. Rosemary Younts, senior vice president, public affairs of Aerojet, says the company has expressed concern that EPA's estimate of a 240-year clean up is misleading and inaccurate. A major treatment plant utilizing biological technology for the treatment of perchlorate, as well as ultraviolet technology to remove the chemical NDMA, was constructed by Aerojet in 1998 and has been in 24-hour operation to treat ground water at a rate of 4,000 gpm. About 4 billion gallons of water have been treated by this facility to date. "Assurance that our communities have safe, clean drinking water has and continues to be the priority concern of the company throughout this process," Younts says. "The company has willingly replaced lost wells, secured additional water supplies and offered long-term water supply solutions."