The amount of decontamination will depend on the type of oil, the weather as well as how people and equipment were used during the operation.
In the case on the left after years of explaining the stupidity of working inside a boom people continue to do so.
Here we have a vessel with 2 outboard engines usually gasoline and never intrinsically safe therefore with fresh oil we have 2 points of ignition. The gases coming from the evaporation phase of the oil are a health hazard to the personnel aboard.
Now from a decontamination point of the vessel is much more contaminated that it would have been if had been it the right place outside the boom with the skimmer getting oiley.
Personnel will get covered in oil usually up to the armpits and will need to have changes of PPE available to keep the operation working.
On the left we have a response vessel during the Erika spill 1999 off France.
The oil was a heavy fuel oil and stuck to everything including the deck and sides of the vessels involved in this incident.
A cleaning station was set up in a port where all the vessels involved were decontaminated before returning to the countries of origin.
From a safety point of view working on oiley deck without a safety rope is asking for someone to fall overboard.
This is an important part of the response and requires everyone to be disciplined for it to work correctly and reduce the effect of secondary pollution. During and at the end of a cleanup there will be a need to clea equipment ready for reuse or repair.
This has to be donewith safety of personnel in mind as well as not causing more contamination to the environment. Lay down areas have to be prepared using existing concrete or other types of temporary impermeable surfaces.
The positioning of decontamination areas depends on the type of incident and geographical location.
Long beaches will require a number of points as people in general are lazy when it comes to having to walk kilometers to the decon point. In many cases people will leave at the nearest exit get into a hire car and return to the hotel.
Over the years many vehicles and kilometers of hotel carpets have had to be paid for. This is where discipline and management has to be paramount.
On the left is a small area for people during a small spill here on the right is a larger version for people and equipment.
In remote areas there is a need for small systems for personnel on the left is a system in a carry bag.
On the rightare 3 6 inch deep paddling pools on level ground covered in plastic sheets stuck together with duck tape.
The tape will unglue with any detergent used, with level ground any contaminated liquid will pool and not run to a seperator if there is one.
This was during the Deepwater Horizon cleanup where more money was spent than any other cleanup so it is even more impressive that such a cheap none efficien system was used.
Decontamination points are not only designed to clean people and equipment they are also where checks of stock levels are done i.e. how much PPE will be required, equipment needs maintenance.
PPE; dependent on the oil type and the terrain involved, gloves, boots whether leather or plastic will have different life spans they may last days or even weeks. White, blue or yellow tyvek suits are common and are worn over the normal cotton overalls. Tyvek suits come in small, medium and large sizes, to me there is no need to buy anything other than large as if they are to small when you bend over the split up the back from the crotch rendering them useless. If the suit is too big for someone it can always be duck taped to fit.
Every incident is different and so may require different decontamination operations.
The location of the incident, the type of oil involved, the weather, the temperature, the number of people and equipment to be decontaminated, and the number of trained personnel available are factors which dictate the method, size, and type of the decontamination operation that will be required.
All response personnel should be briefed on decontamination procedures before entering the Hot Zone. The Decontamination zone should always be kept clean and organised. This will ensure efficient and safe decontamination operations for all personnel involved.
This diagram is based on the OSR idea.
Below is a list to assist with the construction of a decontamination area:
Over the years various manufactures have produced boom washing machines with a view to speeding up the process, here are two many, unfortunately to date there is not one that works well in every situation.
This is because of the different designs of boom, some are inflatable others have permenant floatation so things have to be modified which takes more time than just washing booms with pressure washers.
There is also the fact of the many different viscocities of the oils involved and how long the boom has been waiting to be cleaned. Fresh heavy oil can be very difficult to clean so weathered heavy oil becomes even more difficult.
If used these machines have to be placed in an area where any run off can be collected and processed as they all leak.
One thing that is useful with these machine is they come with pressure washers which can be use on their own for booms and other
equipment. Care should be taken not to cut the material with high pressure hot or cold water, a wafting action is required not pointing at one point.
If your booms have been in oil they will never return to the same colour as when they were deployed. Oil stains them darker.
Practice of Personal Hygiene at Work – Workers should be instructed on the dangers of ingesting hydrocarbons and chemicals through contact with contaminated equipment or clothing, such as gloves coming into contact with the mouth or nose. Facilities for removing protective clothing and bathing, before eating or smoking, should be provided.
Draining the Decontamination Area – The decontamination area where clothing and personal equipment are cleaned should be arranged in such a way that the contaminated water and contaminants are drained into tanks. All due care should be taken to ensure that contaminated waste is not discharged into the normal drainage system, or into the soil under the decontamination area.
Disposal of Contaminated Clothing – Clothing that cannot be cleaned completely or has traces of contaminants needs to be stored safely. Such clothing can bear traces of Special or Hazardous Waste. If there are no incineration facilities, the clothing may need to be handed over to the Local Authority or a company contracted for the treatment of Special Waste.
Medical Assistance – It is essential that adequate medical cover be provided in the event of incidents during the cleanup operations. The cover can take the form of First Aid, Paramedics or a Doctor. The level of medical assistance provided will depend on the assessed risk. During decontamination, it is probable that skin problems or eye injuries or ingestion will occur. Medical Assistance must be available to deal with these problems.