After an industrial gas leak at the Hovensa oil refinery in the U.S. Virgin Islands, officials are urging St. Croix residents to avoid drinking cistern water, reports the Associated Press. Health Commissioner Julia Sheen says Hovensa officials reported a low-concentration leak of light vacuum gas oil and hydrogen sulfide that lasted for 20 minutes Sunday before being contained. Environmental officials found no trace of the chemicals in the air, but Sheen urged people not to drink cistern water from rooftops as a precaution. The cause of the leak was not clear. Hovensa is owned by New York-based Hess Corp. and Petroleos de Venezuela SA, Venezuela''s state oil company. It has a processing capacity of 500,000 barrels per day.