Northrop to clean up Calif. water at Superfund site

*Northrop to build water cleanup system
*Cleanup costs for San Gabriel Valley now top $70 mln
By Gina Keating
LOS ANGELES, Aug 28 (Reuters) - Northrop Grumman Corp (NOC.N) on Thursday reached a settlement with U.S. environmental regulators that requires the aerospace giant to spend about $21 million to clean up groundwater pollution dating from World War II manufacturing through the 1980s.
Northrop operated three of 62 "source properties" that the U.S. Environmental Protection Agency (EPA) found had discharged contaminants into groundwater at a Superfund site in the San Gabriel Valley, northeast of downtown Los Angeles.
The EPA announced the settlment on Thursday in a statement.
The Northrop sites were not the largest source of pollution, said Dustin Minor, EPA's acting branch chief in EPA's Office of Regional Counsel. "They just really stepped up to the plate and worked with the other parties," which will help pay for the clean-up, he said.
A Northrop spokesman had no immediate comment on the settlement, which requires it to build a groundwater cleanup system that will pump out the contaminated water and remove "volatile organic compounds" from degreasers and metal cleaners used in area factories, EPA said.
The treated water will be used for drinking, water reclamation projects or discharged to surface water, EPA said.
The project is aimed at stopping the spread of a pollution plume that stretches six miles in length by one to two miles in width in underground aquifers that provide most drinking water to the valley's one million or so residents, Minor said.
The Superfund site is one of four areas of contaminated groundwater listed by EPA in the San Gabriel Valley in 1984.
The EPA plans to operate the groundwater cleanup system for about a decade while it formulates a plan to remove the contaminants from the aquifers, Minor said.
Northrop has already spent more than $10 million on remediation efforts under a 2002 EPA order, and total cleanup costs in the area so far have topped $70 million, the agency said. (Reporting by Gina Keating; editing by Carol Bishopric)