Why Isn't the MV Arca in the Gulf?

The MV Arca, a dedicated Dutch oil skimming vessel which I had the good fortune to tour in Brest, France in 2002, is the most advanced oil spill response vessel in the world. The vessel, which was built in 1998, operates using two sweeping arms, one on each side of the vessel, which allow oil on the water's surface to be corralled and skimmed on board, where the water in the oil/water mixture will be separated out before being discharged back into the ocean.

The MV Arca has a storage capacity of 1080 m3; that translates into 6792 barrels of oil. When storage capacity is reached, the oil can easily and quickly be transferred to another vessel for eventual disposal and/or recycling onshore. The sweeping arms can recover 240 m3/hr, or 1509 barrels/hr, and can be operated when the waves are six feet high or more. In order to operate effectively, the MV Arca requires aerial guidance to direct it into areas where the oil is of a certain thickness- the MV Arca works best when the oil is thicker. Thus, effective operation of the MV Arca requires oil of a certain thickness, plus good logistical coordination between spotter planes, the MV Arca and other 'receiving' vessels.

The ability of the vessel to separate the water from the oil is a key feature of the MV Arca, since typically the oil/water mixture that is recovered at sea after an incident consists mainly of water. In other words, if you can separate the oil from the water at sea, and just store the oil on board, then you can significantly increase the amount of oil recovered in any given day, and save a lot of time, effort and money in the process. Otherwise, the voluminous oil/water mixture has to be transferred to a shore-based facility where separation can occur. But for the system to really work effectively, the quality of the 'effluent' has to be good enough such that it can be discharged back into the sea. Even Kevin Costner's now famous centrifugal oil spill separation system has only been able to get the oil content in the treated oil/water mixture down to 80 ppm, which is well below the international Marpol standard of 15 ppm. Until such time as the lower figure is achieved, Costner's oil and water will both have to be stored on board, which kind of defeats the purpose of separating the water out of it at sea.

But if the MV Arca is so efficient and effective, then why isn't she in the Gulf? Well, it's absence cannot, apparently, be explained by the infamous US Jones Act, which bars foreign commercial vessels from transporting merchandise between American ports. There is, in fact, an exemption from this requirement for foreign oil spill response vessels, and fifteen other foreign oil spill vessels are said to be operating in the Gulf as we speak as a result of this waiver. So, if it's not the Jones Act holding the MV Arca back, what is? Two possible explanations have been advanced. First, I am told by Sjon Huisman, a Dutch oil spill response expert with the Dutch Ministry of Transport, Public Works and Water Management, that the current practice of mixing the escaping Deepwater Horizon oil with dispersants at a depth of five miles makes mechanical recovery of oil on the surface very difficult, because the oil that eventually does surface from the seabed forms a very thin layer. Second, as with Kevin Costner's centrifugal system, a British colleague of mine claims that the oily water that the MV Arca discharges back into the sea apparently fails to meet the international Marpol standard of 15 ppm of oil as well.

It should be pointed out that while the MV Arca has not been deployed to the Gulf, the US has accepted a Dutch offer of six pairs of the same type of sweeping arms that are employed on the MV Arca. These are being used close to shore, mounted on hopper dredgers, tankers or any other vessels with large storage capacity, according to another Dutch colleague intimately familiar with the MV Arca.

But are the two reasons given above for the MV Arca's absence from the Gulf really plausible? For one thing, if it were deployed to the region, perhaps those vast quantities of controversial subsea dispersants would no longer be used on the spill. And as for the claim that the quality of the oily water discharged by the MV Arca fails to meet international Marpol standards, this appears to be somewhat of a red herring. For, as Mr. Huisman explains, the 'decanted' water is pumped overboard well in front of the sweep, so that if there is oil in it, it can be recovered in a second sweep. Moreover, if the quality of water the MV Arca water discharges is good enough for Europe, the home base of the vessel, then why isn't it good enough for the Gulf?

It's all rather hard to take, really. Just imagine how much oil this super-modern vessel could have recovered from the Gulf if it had been working there for the past fifty days or so in the immediate vicinity of the Deepwater Horizon incident site. Put another way, just think how much oil could have been prevented from spreading and emulsifying, some of it eventually ending up on shore, if the American authorities had done a Net Environmental Benefit Analysis, and concluded that overall the effect of the MV Arca's operations on the marine environment would be overwhelmingly positive, as most certainly seems to be the case.

It's a shame, really, and it puts paid to the claim that both BP and the US authorities are pulling out all the stops to contain the spill and mitigate the damage from it. If that were true, wouldn't they have commissioned the MV Arca long ago? In short, this looks like just another instance of ineptitude on the part of Deepwater Horizon Unified Command, which includes the US Coast Guard, BP, NOAA and the EPA.