Environmental Response Policy

5/25/2017: IOSC Recap #4-Tank Barge APEX 3508: Best practices for detection and recovery of sunken oil

Fourth in our IOSC series is a recap of a presentation by Cmdr. Mark Sawyer, commanding officer of Marine Safety Unit Paducah, Kentucky, titled “T/B APEX 3508 Case Study: Best Practices for Detection and Recovery of Sunken Oil.” APEX 3508 released an estimated 120,500 gallons of slurry oil into the Mississippi River after two tugboats collided near Columbus, Kentucky in September 2015.

 The majority of the oil sank to the riverbed and Sawyer shared with conference attendees some of the challenges responders faced when recovering sunken oil, lessons learned, and recommendations for future incidents. The presentation was part of the “Case Studies” From the Past to the Future,” moderated by Cmdr. Lushan Hannah.

The vicinity where the APEX 3508 case occurred was unique because the collision occurred at the confluence of five major waterways transited annually by 8,500 towboats and carrying goods worth $45 billion to the U.S. economy. Additionally, this area intersects four states, three Environmental Protection Agency regions, and four Army Corps of Engineers districts.

“There’s a lot of coordination required, because it becomes complicated, jurisdictionally, depending on the incident and its location,” Cmdr. Mark Sawyer, the incident commander, said.

Other incident challenges included unreliable connectivity, a lack of logistics support, and an incident command post that had to be established about an hour away from the incident location. Additionally, the water itself was 20 meters deep and was the home to two freshwater mussel habitats.

Initially, Sawyer said the unified command was unsure if the oil had drifted downriver and surfaced, or was suspended in the water column. A 16-mile section of the river was closed to ship traffic over concerns about migration of oil and passing vessels being oiled as well.

“You can imagine shutting down this economically vital river for a couple of days,” Sawyer said. “There is a lot of pressure to locate and evaluate the risk of the oil on the environment and the impact to vessels wishing to transit the area so the waterway can be reopened to commerce as soon as possible.”

Overflights revealed very little oil sheen in the area. Using side scan sonar, provided by a member of the local fire department, and a salvage diver, responders discovered the oil was on the bottom of the riverbed. The decision was made to use an environmental clamshell, which is designed to reduce the amount of water recovered and hold the maximum amount of product. During the 23-day operation, 120 personnel recovered between 50-70 percent of the product.

“This case has received a lot of attention in both government and private entities because it’s one of the largest sunken oil spills and largest recovery rates in recent times,” Sawyer said during his presentation. “It’s also generated a lot of discussion because, over the last several years, we’ve been debating about the best ways to approach sunken oil to increase our preparedness efforts.”

Sawyer summarized the lessons responders learned from the APEX 3508 spill:

  • The use of a professional salvage team increased capabilities and resulted in higher product recovery rate.
  • Maintain awareness of the state and municipal assets available. The side scan sonar used to detect the oil was provided by a local responder, which meant clean up operations could begin more quickly
  • The unified command established a Maritime Transportation Recovery Unit (MTSRU) and a senior vice president from a local tow boat company was assigned to run it, with Coast Guard support, and he was able to clear over 80 vessels waiting to transit in a 48-hour period.
  • The unified command took full advantage of external resources and specialized teams, including bringing in a NOAA scientific support coordinator and the use of the Environmental Response Management Application (ERMA).
  • Local partners established a Great Rivers Spill Coordination Group to address the nuances of the jurisdictional overlap in the area and ensure both tactical and coordination response plans were incorporated.
  • The American Petroleum Institute’s Submerged Oil Detection and Recovery Field Operations Guide is a valuable tool for determining optimal detection and recovery methods given the product and the environment.


Since APEX 3508, the Coast Guard Office of Marine Environmental Response Policy established non-floating oil classifications to allow oil spill response organizations and salvage companies with those capabilities to apply. View MSIB 07-16, MSIB 13-16 or the Maritime Commons post on the subject for more information. To read more about the APEX 3508 response, visit NOAA’s Incident News website.

Want to read more from the Coast Guard at the International Oil Spill Conference? Check out our previous Maritime Commons posts:

6/5/2017: IOSC Recap #5 – USCG Sector Delaware Bay: Response to rail incidents planning project
5/25/2017: IOSC Recap #4-Tank Barge APEX 3508: Best practices for detection and recovery of sunken oil

5/25/2017: IOSC Recap #3-Tank Barge Argo: A case study on the employment of NCP special teams

5/23/2017: IOSC 2017 Recap #2-In a hostile environment? Skills needed for success

5/23/2017: IOSC 2017 Recap #1- Time for a refresh in the pre-spill planning consultation process

5/16/17: IOSC 2017 – Opening plenary session – Prevent, Prepare, Respond & Restore

This blog is not a replacement or substitute for the formal posting of regulations and updates or existing processes for receiving formal feedback of the same. Links provided on this blog will direct the reader to official source documents, such as the Federal Register, Homeport and the Code of Federal Regulations. These documents remain the official source for regulatory information published by the Coast Guard.

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