Oil Spill Clean-up Nears End

In the last two weeks an additional 1700-2000 gallons of used oil that spilled into the canal near the George Town Landfill during Hurricane Ivan have been recovered by the Department of Environmental Health with help from Texas A & M University’s National Spill Control School (NSCS) and local agencies. The operation was carried out without the use of chemicals and brings the total oil recovered to over 10,000 gallons.

A team from the school arrived on Grand Cayman on 3 March to assist with the actual clean-up phase of the oil spill located at the north-western end of the George Town Sanitary Landfill.

“Consultants from the NSCS have been invaluable in assisting the DEH in this phase of our recovery operation,” said Chief Environmental Health Officer Roydell Carter.

During Hurricane Ivan, a five foot-plus surge swept through the landfill from the North Sound, dislodging drums containing used oil. The drums had been stored at the landfill’s recycling area awaiting shipment to a recycling operation overseas.

Roy Coons and David Jensen of NSCS had previously visited the island on 1-4 February 2005 to carry out a preliminary assessment of the landfill cleanup operation at the request of the DEH and submitted a proposal with their recommendations for the remainder of the operation. On their recent visit, the two experts were accompanied by colleague Carl Christiansen who has over 25 years of experience in the field of oil spill cleanup and has conducted training exercises with the Department of Environment (DEH) in the past.

“After the consultants reviewed the work site on their first day here, the team commenced operations the next day, based on the work plan previously accepted by the DEH. On Friday the equipment was set-up and debris removed and by that afternoon free oil was being collected from the canal closest to the Esterly Tibbetts Highway and North Sound dyke road junction,” said Mr. Carter.

Oil skimmed

DEH Laboratory Senior Research Officer Antoinette Johnson explained, “The team’s approach was to wash the oil towards the earthen berm barriers that, along with oil spill booms, had been placed to contain the spilled oil and to prevent pollution. This allowed the free oil to pool in a layer thick enough to collect easily with skimmers. At the same time, the vegetation was washed and oil flushed from behind the rocks at the side of the canal.”

The large amount of debris in the canal complicated the skimming process, so a DEH team removed the leaves and other detritus by hand to prevent clogging the skimmer. Oil and water collected was pumped into collection tanks and allowed to settle, at which point the water was drained back into the canal to repeat the cycle.

Oil soaked debris

Marl and mulch were laid to firm the dyke road surface and soak up oil to prevent further runoff into the canals. Oil-soaked debris that had trapped oil in pockets was also removed. The team preserved as much live vegetation as possible and rinsed the tree roots of accumulated oil removing any dead vegetation that was trapping the oil.

“This recent phase of the project resulted in an estimated 1700 – 2000 gallons of free oil being recovered from both sections of the canals. Monitoring of the site will be ongoing and any small remnants of oil that may accumulate will be removed. All of these procedures deliberately avoided the use of chemicals or other harsh methods in an attempt to minimize the damage to the surrounding mangroves,” said Mr. Carter.

Ms Johnson said that monitoring of the site will continue in the medium to long term, with samples to be collected for analysis next week and in 3-4 months time. “By isolating the contamination, removing the bulk of the spilled product and washing the vegetation, natural bio-remediation of any residue can now proceed,” she said. NSCS estimates that within 4–6 months the majority of residual staining and clearing of residue of tree roots and canals should be completed. Therefore, there should be no permanent damage caused by this oil spill.

“Several agencies have given their assistance to this project including lending equipment and expertise. These include the DOE, MRCU, Petroleum Inspectorate, Water Authority and CIRO,” Mr. Carter said. The Ministry of Planning, Communications, District Administration and Information Technology lauds the cooperative efforts of everyone involved: “It is testament not only to the local expertise and resources available in Cayman, but also to our long-standing relationships with overseas consultants who we are able to rely on in such situations.”

Oil spill recovery

In just under two months the DEH team, assisted by the NSCS consultants and in collaboration with the DOE and the MRCU has:

• Contained the spill to landfill property, minimizing impact to the North Sound and surrounding mangroves.
• Removed, by mid-January, approximately 350 drums, either full or partially filled with used oil from the dyke roads and canals. Another 450 empty drums were collected and crushed for disposal.
• Pumped approximately 8,500 gallons of oil from those drums recovered which contained oil. Many of these drums contained a mixture of oil and water.
• Recovered an additional 1700 – 2000 gallons of free product from the waterways using the work plan.
• Removed oil-soaked debris from the canal and washed vegetation.
• Provided practical training to DEH personnel in oil spill response. Five DEH personnel received recertification in Hazardous Waste Operations and Emergency Response (HAZWOPER) as a result of working on this project.
• Started work on the improvements for the waste oil recycling programme to minimize the likelihood of a similar occurrence in the future.
• Improved the normal waste oil storage and handling area.