Oil company Conoco-Phillips has agreed to clean up a 2003 oil spill in Nipomo Creek near the Dana Adobe.
The cleanup is expected to take place next summer, or the summer of 2012 at the latest, according to officials with the Regional Water Quality Control Board in San Luis Obispo.
The oil came from a leaky crude oil pipeline, which has since been repaired. The leak resulted in a 300-foot, roughly circular area of contamination running beneath the creek.
The oil does not appear to be contaminating the creek because of a clay layer beneath the creek bed, water board staff members say. However, contaminated soil could be present as little as 2 to 3 feet beneath the creek and has contaminated the groundwater.
Under the cleanup agreement, 300 feet of creek channel will be excavated to a depth of 4 feet. An impermeable lining will be installed to prevent any recontamination.
The excavated area will be backfilled with clean dirt and any removed vegetation will be replaced with native plants and trees. The banks of the creek will also be contoured to prevent erosion.
The pipeline was originally owned and operated by Unocal. It has since been taken over by ConocoPhillips, which operates a refinery on the Nipomo Mesa.
The final cleanup agreement was signed last month.
Reach David Sneed at 781-7930.