Slick Solution for Oil Spills

In the midst of increasing oil tanker traffic along U.S. coasts, Texas is using new technology to protect beaches, wildlife and marine resources.

by / August 31, 1996
In the midst of
increasing oil tanker
traffic along U.S.
coasts, Texas is
using new technology
to protect beaches,
wildlife and marine
resources against
oil spills.

On March 18, a barge carrying 17,000 barrels of oil buckled in heavy weather off the coast of Texas, spilling an estimated 5,000 barrels of fuel oil into Galveston Bay. To prevent the barge from breaking up further, the tow captain grounded it on nearby Bolivar Peninsula until the remaining cargo could be safely transferred to another vessel. The slick from the ruptured barge separated into two sections. North winds pushed the larger one out into the Gulf. The other came ashore at a nature preserve.

In Galveston, the Oil-Spill Response Division of the Texas General Land Office (TGLO) immediately mobilized a joint effort with the United States Coast Guard, the city of Galveston and Buffalo Marine Services Inc. (the responsible party) to begin cleanup operations. Within an hour of the spill, crews and equipment were removing oil-soaked sand from the beaches and setting thousands of feet of protective booms to minimize further impact on environmentally sensitive areas, marinas and yacht basins.

At the same time, computers at Texas A&M University's Geochemical and Environmental Research Group (GERG) began querying the new Texas Automated Buoy System (TABS) via cellular phone for surface-current data in the general area of the slick. The data was processed into ASCII and PostScript files and sent to the
TABS home page on the Web , a site that also receives wind and weather data every two hours from the National Oceanic and Atmospheric Administration (NOAA).

In Austin, TGLO computers downloaded the data from GERG and NOAA into a workstation running a continuous oil-spill modeling program. Within two hours of the spill, response planners had an accurate simulated trajectory of the offshore slick and a picture of the path it would take over the next 12 hours. After confirming the trajectory with Coast Guard overflights, TGLO directed skimming vessels and other resources directly to the slick. In less than a week, round-the-clock cleanup operations had reduced it to scattered tar balls, later collected by smaller inshore skimmers.

As U.S. oil imports continue to rise, tanker traffic on the Gulf is increasing, and with it the potential for oil spills. According to GERG Research Scientist Frank Kelly, most of the oil coming into the United States now crosses the Gulf of Mexico. "The volume is huge. In 1995, 275 million barrels of oil -- equivalent to several hundred Exxon Valdez loads -- passed west of the Mississippi Delta. This year, it is expected to be 300 million."

With 370 miles of coastline -- much of it pristine beaches and nature preserves -- the state puts a high priority on spill-response capability. TGLO Scientific Support Coordinator Dr. Robert "Buzz" Martin explained how that priority is funded. "The Texas Legislature created the Coastal Protection Fund, which is supported by a two-cent-per-barrel fee on all crude-oil products moving through Texas ports. The fund is used to ensure that a cleanup operation will proceed in the event the spiller is unable to cover the cost, or the responsible party cannot be located. The fund is capped at $25 million, which means the per-barrel fee is suspended once the $25 million limit is achieved. If the fund falls below $14 million, the per-barrel fee is reinstated."

From the Coastal Protection Fund, the Legislature earmarks $1.25 million annually for TGLO oil-spill R&D. One of the most recent developments of the program is TABS. Designed and managed for TGLO by GERG, TABS is a network of six oceanographic monitoring buoys, positioned along shipping lanes and near oil platform clusters, 10 to 25 miles offshore. The buoys are designed to monitor and store data
on a range of oceanographic conditions, the most important being the force and direction of surface currents. Each buoy in the half-million-dollar system is interrogated once every six hours from computers at GERG.

TABS grew out of a specific request by TGLO for a system that could provide realtime current data, essential elements for running accurate spill-trajectory models. With accurate trajectories, planners can put response resources in place ahead of an offshore slick, and eliminate or significantly diminish it before it comes ashore. When a spill alarm goes off, planners can load in realtime data and have an accurate trajectory model in under 90 minutes. If TGLO requires data more frequently, GERG computers can be instructed to call the buoys
more frequently.

"We were able to tell scientists at GERG exactly what we needed," said Martin. "As a result, the TABS R&D project yielded a deliverable that is both cutting edge and practical. It is absolutely critical to our ability to predict where oil will go in waters along the coast. There are not many tools we can use to do that, but oil-spill trajectory modeling is one.

"The trajectory model, Spillsim, generates simple black-and-white maps -- shorelines and the position of the oil, but not data layers." Martin explained. "If we want to see data layers of other resources at risk, we transfer the trajectory to an ArcInfo GIS. Shorelines match up because we used existing hydrography layers from our GIS to provide Spillsim with a geographic reference."

Martin pointed out that with realtime wind and surface-current data, planners can actually see changes in the trajectory as the slick moves. "Into the third day of the Buffalo Marine spill, for example, the trajectory showed the slick heading northward with a possible impact in the Sabine-Port Arthur area, so we started looking there for resources we might need -- skimming vessels, protective booming and so forth. The next day, TABS showed the current had started to reverse, so even without sending out an overflight for confirmation, we knew we could stand down the Port Arthur alert and position resources where TABS showed the current was coming around to -- farther down the coast toward the Barrier Islands, San Jose and Los Padres."

Patricia Clark, GLO maritime affairs coordinator, added that GLO planners ran the trajectory model as a cooperative effort with the NOAA trajectory team. "We shared data and results, and acted as a check for each other. Whenever we compared the two trajectories, they were very close."

According to Martin, TABS began as the sole effort of TGLO, but welcomes participation of the private sector. "Both Aramco Services Co. and the Marine Spill Response Corp. (MSRC) have provided support for TABS. MSRC has been donating ship time for deployment and maintenance of the TABS buoys," explained Martin. "Aramco provided the forum for the first public TABS meeting, and has given Texas A&M GERG a $30,000 grant to help in the maintenance of the system. Industry involvement is critical to maintaining the operational focus of the TABS project, so we are seeking more involvement there."

GERG has a pending proposal with Louisiana State University to the Minerals Management Service, U.S. Department of the Interior, that is expected to provide an additional $100,000 per year over two years for TABS research. Right now, available funding is the limiting factor in expanding the system. A buoy and anchor cost $30,000. The annual funding level of the present system is $280,000. "We are still in a development mode and seeking funding to expand the system," Kelly said. "Obviously, with a larger system, the operating cost per buoy would be less." He emphasized that no new technologies were developed for TABS; the system was designed using proven, off-the-shelf equipment.

Besides additional
sensors for meteorological and oceanographic data, Kelly would like to see the system eventually expanded to 12 buoys. "You don't need a huge quantity of these things, just enough so that you can begin to guess fairly accurately what is going on between them. One of our R&D tasks is to take the surface current information and the sea-level data, and put them all together into an interpolation "now-cast" of the current. If you have a now-cast, then with the model you can forecast. What we want to do is now-cast the currents offshore. With these buoys, we can begin to do that."

In the face of rising oil imports and increasing tanker traffic along U.S. coasts, states like Texas are looking for more effective ways to protect beaches, wildlife and marine resources from the ravages of oil spills. Technologies like TABS may hold some of the answers to eventually eliminating spills before they come ashore. If the cost of achieving that goal seems high, it is insignificant compared to the price of an Exxon Valdez.

Bill McGarigle is a freelance writer specializing in GIS, GPS, and marine-related topics. E-mail: .