The Hovensa refinery sprayed a vapor cloud of oil into the atmosphere early Sunday morning when a small line in a desulfurizing unit burst, according to the company.
Hovensa activated its alarm to alert nearby residents and shut down the leaking unit. The V.I. Police Department closed the road immediately north of the refinery and a small part of the Melvin Evans Highway. The highway was reopened after being inspected, according to Hovensa.
Health Commissioner Julia Sheen and Robert Mathes, commissioner of Planning and Natural Resources, issued a joint advisory Sunday afternoon cautioning nearby residents to avoid drinking cistern water.
Hovensa officials reported to DPNR that a low concentration of the released gas, which listed ingredients as light vacuum gas oil and hydrogen sulfide, began at 6:02 a.m. Sunday and was contained within 20 minutes. The company also completed field air monitoring of down-wind communities and advised local government officials that no “detectable concentrations” were found.
Hovensa said, however, that residents in Estates Barren Spot, Ginger Thomas, Sunny Acres, and Strawberry may find spots of light oil on their property, but said these spots are harmless and can be safely removed with soap and water.
Health and DPNR are urging residents in those areas to avoid drinking cistern or barrel water collected from rooftops.
Hydrogen sulfide gas is also known as “sewer gas” because it is often produced by the breakdown of waste material. At low levels, hydrogen sulfide gas has a strong odor similar to rotten eggs.
Sheen and Mathes said their agencies will alert the public as more information becomes available.
Residents who have questions or need assistance can contact a hotline set up by Hovensa in the wake of the gas release at (340) 692-3999.
There have been several similar oil-spray events over the years. In fall of 2008, Clifton Hill and Profit homes were sprayed and Hovensa subsequently cleaned the roofs, gutters and cisterns of affected homes.
In 2006, water mixed with crude oil triggered a pressure-release valve, spraying out more than 100 gallons of oil in a fine mist. The contamination from that incident was confined within the boundaries of Hovensa. In 2005, water mixed with hot oil also resulted in an airborne oily mist. Roads were closed briefly and monitoring stations set up, but there was no report of contamination outside the plant.
In 2002, spray from a pressure-release valve led to warnings to Clifton Hill and Profit residents not to use their cistern water, but subsequent tests contracted by Hovensa showed no effect on area water supplies.