OGJ Senior Staff Writer
HOUSTON, May 20 -- The US Environmental Protection Agency issued a directive on May 20 requiring BP PLC to identify and use a less-toxic and more-effective dispersant from a list of EPA-authorized dispersants for use on the oil spill in the Gulf of Mexico.
The directive applies to dispersants used both at the seabed and on the water’s surface. Chemical dispersants break the oil into smaller droplets so they degrade faster. EPA has not identified any significant effects on aquatic life, it said in a news release.
BP and government scientists have been monitoring water samples to determine the level of dispersants, and that information has been posted online by EPA.
On May 15, EPA and the US Coast Guard authorized BP to use dispersants at the wellhead on Mississippi Canyon Block 252 following the use of subsea dispersants in three tests. Dispersants have been used on the surface for weeks.
“The directive requires BP to identify a less-toxic alternative to be used both on the surface and under the water at the source of the oil leak within 24 hr and to begin using the less-toxic dispersant within 72 hr of submitting the alternative,” a May 20 EPA news release said.
If BP is unable to identify available alternate dispersants, then BP must provide EPA and USCG with a detailed description of the alternate dispersants that it considered. BP also must provide reasons why products are unacceptable under required standards.
Some 640,000 gal of dispersants had been deployed on the spill as of May 18 with 53,000 gal applied at the seabed using coiled tubing to deliver it. Airplanes applied the rest on the surface.
The dispersants BP used already on are EPA’s approved list, but this oil spill response is the first time dispersants have been used at the seabed. Dispersants also are being used in unprecedented volumes, EPA Administrator Lisa Jackson said.
“Because of its use in unprecedented volumes and because much is unknown about the underwater use of dispersants, EPA wants to ensure BP is using the least-toxic product authorized for use,” the agency said May 20. “We reserve the right to discontinue the use of this dispersant method if any negative impacts on the environment outweigh the benefits.”
Previously, USCG Rear Adm. Mary Landry told reporters that subsea application of dispersants mean fewer dispersants can be used than the volume of dispersants that are needed to work on the surface.
BP has used a chemical dispersant called Corexit made by Nalco Co. During recent congressional hearings in Washington, DC, BP America Chairman Lamar McKay said federal spill response officials were involved along with BP in selecting Corexit.
McKay said availability of large volumes of two formulations of Corexit was part of the reason for selecting that particular chemical.
The EPA directive came a day after lawmakers expressed concerns during a House committee hearing in Washington about the brand of chemical dispersants being used in the Deepwater Horizon accident.
Rep. Jerrold Nadler (D-NY) questioned the selection of Corexit instead of using other dispersants on EPA’s list that he believes might be safer. Nalco’s board includes a former executive from BP and also a former executive of ExxonMobil Corp.
“Why would you use something that is much more toxic and much less effective, other than you have a corporate relationship with the manufacturer,” Nadler said.
Doug Suttles, chief operating office of BP Exploration & Production, said May 19 that subsea delivery of dispersants appears to be very effective.
‘Our efforts…clearly are making a difference,” in the amount of oil being seen on the gulf surface, he said during a news conference from Robert, La.
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