ALTON, Ill., April 17, 2012 /PRNewswire/ -- The Simmons Firm, a national litigation firm known for handling complex, toxic exposure cases, filed suit today on behalf of private property owners in Roxana, Ill., against Shell Oil Company, ConocoPhillips, and WRB Refining LP. The Roxana property owners allege that carcinogenic chemicals, including benzene, released from the Wood River Oil Refinery have contaminated their properties. They seek compensation for that damage and other relief. This newest filing, on behalf of private residents, follows in the wake of a lawsuit the firm filed March 20 on behalf of the Village of Roxana, itself. The earlier suit was filed in conjunction with the Roxana Village Attorney. Both suits allege claims including trespass, public and private nuisance, and unjust enrichment. "Shell's own testing and reports show that benzene from the Refinery has migrated onto the property of dozens of homeowners in the residential portion of Roxana. This creates a risk of vapor intrusion, particularly in structures with basements and other sub-slab construction," said Simmons Firm shareholder Derek Brandt, who leads the firm's efforts on behalf of the property owners. Benzene contamination throughout the affected properties measured, in some places, as high as 2.6 million percent of the allowable limits set by the Illinois Pollution Control Board, according to testing done by Shell's contractor URS Corporation. The contamination extends over several blocks of the Village's residential area. The fugitive emissions are attributed to broken pipelines and the refinery itself, according to the complaint. Much of the contamination is underground, resulting in the pollution of groundwater, soil and the soil-gas vapors under Roxana. Test results were positive for benzene contamination in the alleys from East Second to East Eighth streets. Excessive levels were detected at many locations, but contamination was the highest in the Village's Public Works Yard, where it registered some 26,000 times (or 2.6 million percent of) the allowed limit at certain depths.