River sediment, dredging eyed as possible sources of Gulf pollution

The following is the text of a press release issued by the U.S. Coast Guard:
(NEW ORLEANS) — The Coast Guard continues to respond to reports of pollution in the Gulf of Mexico, Sunday. Saturday, watchstanders at Coast Guard Sector New Orleans received notifications of possible pollution that varied in size and location.
The largest sighting was described as a dark substance floating on and beneath the surface of the water stretching 100 miles out into the Gulf of Mexico south of Grand Isle. The Coast Guard Cutter Pompano was deployed and gathered samples, which have been analyzed and have been found to contain only trace amounts of petroleum hydrocarbons, oil and grease.
They were analyzed using the Louisiana Department of Enviromental Quality’s standard for clean, which is less than 64.9 mg/L (65 ppm) for petroleum hydrocarbons and 9,988 mg/L (10,000 ppm) for oil and grease. The first sample collected showed 8 mg/L for total petroleum hydrocarbons and 86 mg/L for oil and grease. The second sample collected showed 5 mg/L for total petroleum hydrocarbons and 15 mg/L of oil and grease. At this point, the dark substance is believed to be caused by a tremendous amount of sediment being carried down the Mississippi River due to high water, possibly further agitated by dredging operations.

Also, the Coast Guard was notified Sunday that an oily substance was washing ashore on Elmer Isle, Fourchon Beach and Grand Isle. Coast Guard investigators are on scene and assessing the situation. Currently, the west end of Grand Isle, the east and west end of Elmer Island, and intermittent areas of Fourchon Beach have been impacted. Reports of sheen in Timbalier Bay were also reported, but there is no confirmation of Timbalier Island being impacted. Oil spill response assets have been mobilized, and as part of the Coast Guard’s response plan, have begun pre-staging boom in order to prevent oil from impacting various bays and other environmentally sensitive areas.

Samples have been taken from the shoreline impacts for testing, but the oily substance is not, at this time, suspected to be residual oil from the Deepwater Horizon oil spill.

“We have 10,000 feet of hard boom and 9,000 feet of five-inch sorbent boom ordered into the area. We have 5,000 feet of each boom already delivered and staged in Grand Isle,†said Capt. Jonathan Burton, commanding officer Coast Guard Marine Safety Unit Morgan City and Federal on Scene Coordinator for the response.

ES&H has been hired to begin cleaning up the impacted shorelines.

“To avoid delays in resource availability and delivery, we have taken a forward leaning approach and authorized ES&H to procure whatever additional boom and resources they need,†said Burton.

The separate incidents are under investigation and more information will be released as it becomes available.

By Professional Mariner Staff