Florida Panhandle and Alabama Beaches Welcome Spring Break: Free of Tar Balls at Last Ping Wang, James H. Kirby III, and Jun Cheng Coastal Research Laboratory, Department of Geology, University of South Florida, Tampa, Florida, 33620 From April 20 th to July 15 th, 2010, crude oil from the explosion and sinking of the DV Deepwater Horizon platform servicing the British Petroleum (BP) Macondo 252 oil well leaked crude oil into the Gulf of Mexico. By mid May, the crude oil spewing from the MC252 well was washing onshore and depositing on over 300 km of sandy barrier-island beaches along the northeast Gulf of Mexico coasts of Alabama and Florida. The ongoing environmental and economic impacts of this unprecedented oil spill to the low-lying, microtidal barrier-island beaches are immense. Intensive manual and mechanical beach cleanup was conducted over the past nine months and is still ongoing at some locations. After the eighth trip (February 19 th through 21 st ) to the Alabama and Florida panhandle beaches since the spill, we are pleased to report that the beaches appear to have little to no visible tar balls on the surface, below the surface, or in the swash zone. Our field investigation extended from Panama City Beach, Florida westward to Dauphin Island, Alabama. The sugar sand beaches along the Florida Panhandle and Alabama coasts are ready for the 2011 Spring Break! In this report, we highlight some of the major beach oiling events, progress of beach cleanup, and compare present beach conditions with those during the spill and contamination. This study is funded solely by the National Science Foundation. Initial Beach Oiling Early June, 2010 Nineteen days after the Deepwater Horizon Drilling Vessel accident on April 20 th, 2010, tar balls started to wash onshore at Dauphin Island, Alabama. More oil product washed onshore along Alabama and Florida panhandle beaches at the beginning of June, 2010. The initial beach oiling was mostly in the form of sporadic tar balls distributed mainly along Alabama beaches (Figure 1). Buried tar balls were found at several of the study sites (Figure 2), largely confined to the zone between the active berm crest and maximum wave runup limit (Figure 1). Controlled by the calm weather, tar balls were typically buried to a shallow depth of less than 10 cm (0.3 ft). This initial beach oiling was mostly cleaned by manually picking up the tar balls.
Figure 1. Initial beach oiling along Alabama beaches early June, 2010. Note that most of the oil is distributed between the active berm and the maximum wave runup, Dauphin Island, Alabama. Photo was taken on June 7 th, 2010. Figure 2. Buried and subsequently exposed oil within the active berm. Scale along the right side of the ruler equals 2.54 cm (1 inch). Photo was taken on June 7 th, 2010.
A Major Beach Oiling at the End of June, 2010 A major beach oiling event occurred at the end of June 2010, highlighted by the landfall of oil sheets along Pensacola Beach, Florida (Figure 3). Due to the calm weather conditions, the beached oil distributed in a relatively narrow zone, of typically less than 5 m (16 ft) wide across the beach. The beached oil became buried quickly within one to three tidal cycles to a depth of up to 15 cm (0.5 ft) (Figure 4). The intensive beach oiling and the large amount of buried oil made manual cleanup inefficient and less effective. It became apparent that mechanical cleanup was necessary. Figure 3. Landfall of an oil sheet along Pensacola Beach, Florida. Photo was taken on June 24 th, 2010. Figure 4. Buried oil sheet along Pensacola Beach, Florida. Photo was taken on June 24 th, 2010.
Severe Beach Oiling Induced by the Distal Passage of Hurricane Alex at the Beginning of July, 2010 The first Hurricane in 2010, Alex, although made landfall some 800 km away at the border of Texas and Mexico, washed tremendous amount of oil onto the Alabama and Florida panhandle beaches. All forms of oil contamination, including tar balls (<10 cm (4 inches) in diameter), tar patties (>10 cm (4 inches) in diameter), tar cakes (>3 cm (1.2 inches) in thickness), oil sheets (>5 m (16 ft) in length or width), and oil stains, were found along nearly 200 km (120 miles) of Alabama and Florida panhandle beaches. The high wave energy distributed the oil contamination over a much wider zone, up to 40 m (130 ft), across the beach as compared to the previous oiling events. The active sediment transport associated with the high waves also resulted in deep burial of the beached oil of up to 60 cm (2 ft) below the surface (Figure 6). Figure 5. Beach oiling induced by the distal passage of Hurricane Alex. Note the wide distribution of oil across the beach and the different forms of contamination in the different beach zones. Oil stains from individual wave runup is observed from the foreshore to the berm. Inset: A continuous oil sheet occurs along the maximum high-tide runup landward of the backbeach trough. Photo taken July 1, 2010 after the distal (over 800 km) passage of Hurricane Alex.
Figure 6. Thick buried layers of oil contamination. Oil layers of up to 15 cm (0.5 ft) thick (lower photo) were buried to 50 cm (1.6 ft) (upper photo) below the beach surface. The red arrows begin at the location of the excavated trench (the middle photo) and terminate at what lies beneath the surface, which is buried oil. Photo was taken July 26 th, 2010.
Due to the massive beach oiling induced by the high waves associated with the distal passage of Hurricane Alex, manual cleanup simply could not handle the quantity. Aggressive mechanical cleanup was initiated. The initial mechanical cleanup has left tens of km of beaches covered with pulverized tar balls of about 1 cm (0.4 inch) in diameter (Figure 7), while the buried oil was largely un-touched (Figure 6). Figure 7. Initial mechanical cleanup has left numerous tar balls on the beach. Photo was taken on July 26, 2010 at the same location of Figure 5. Continued Mechanical Cleanup during the Winter of 2010 Following the capping of the leaking well, more aggressive mechanical cleanup involving extensive digging and sieving was conducted during the winter of 2010. This was called dig-siftrefill by local residents. We investigated the results of the winter-2010 cleanup from 19-21 February, 2011. Similar locations as studied earlier (discussed above) were visited. We found that most of the small surface residual tar balls on the beach, as shown in Figure 7, were removed or further pulverized to sizes that cannot be identified with untrained eyes. The beaches appear to be in similar condition as before the spill, except the massive temporary tire/tilling tracks (Figure 8). In addition, the buried visible oil we identified earlier has all been removed or pulverized to sizes that cannot be identified without the use of ultraviolet light. Figure 9 shows a
trench that was dug at similar location as that of Figure 6. Although the sand still glows orange under UV light, no visible oil contaminations, e.g., tar balls or stained light brown sand, can be identified, which contrasted significantly with the contamination observed in Figure 6. It is worth noting that the example given here from Gulf Shores, Alabama represents one of the most severely contaminated beaches observed by our study. All the other locations from Panama City Beach, Florida to Dauphin Island, Alabama investigated by this study demonstrated similar cleanup conditions, except the initial contamination was to a lesser degree than illustrated here. Figure 8. Clean beach at Gulf Shores, Alabama after the 2010-winter cleanup. Photo was taken on February 21, 2011 at the same location of Figure 5 and Figure 7. Note that almost all the small surface residual tar balls were removed. In addition to investigating surface and buried oil on the beach, the potential tar ball distribution in the swash zone near the shoreline was also examined. The swash zone is where many beach visitors, particularly young children, tend to play (Figure 9). Since the weathered tar balls with sand grains have become heavier than sea water, our concern was that tar balls may concentrate in the swash zone and impose some risk to swimmers. One of our initial concerns about buried oil was that it may be eroded by high waves and be overwashed into the backbarrier environment (e.g., wetland or bay) or become concentrated in the swash zone along the shoreline. During the 3-day field investigation, very few small tar balls in the swash zone along the Alabama and Florida panhandle beaches were found. This is attributable to the relatively calm 2010 summer and winter seasons. Based on qualitative field observations, the beaches
seem to have been fairly stable during this period of time and a limited amount of buried oil was eroded and redistributed by wave action. This allowed the intensive cleanup efforts to effectively remove or pulverize the surface and buried oil. Figure 9. No visible oil contamination was identified in this 90-cm (3-ft) trench, excavated at similar location as those in Figure 6. Photo was taken on February 21, 2011. Figure 10. Negligible amounts of tar balls were found in the swash zone, a favorite place for children to play, during the February 19-21 field investigation. Photo was taken on February 21, 2011.
Summary A 3-day field investigation from 19-21 February, 2011 was conducted along the Alabama and Florida panhandle beaches, extending from Panama City Beach, Florida to Dauphin Island, Alabama. This is the eighth field study by the Coastal Research Laboratory at the University of South Florida, funded by the National Science Foundation, since the Deepwater Horizon drill rig accidence on April 20 th, 2010. This report briefly documents the beach oiling events since the beginning of June 2010 and the progress of manual and mechanical cleanup. The focus of this eighth field investigation was to examine the beach conditions after intensive mechanical beach cleanup during the winter of 2010. Overall, negligible amount of oil contamination, mostly in the form of small tar balls (less than 1 cm (0.4 inch) in diameter) was found on the beach, below the beach surface, and in the swash zone along the shoreline during this field investigation. We are particularly pleased with the findings, as the sugar sand beaches along Alabama and Florida panhandle coast prepare for the 2011 Spring Break.