Methods of Fuel Tank Decommissioning

Methods of Fuel Tank Decommissioning

Abandoning tanks in-situ

Any tank to be abandoned in place should be rendered safe by one of the following methods:

  • by filling with cement slurry using the following procedure:
    1. drain back all pipelines associated with the tank and remove all residual petrol
    2. the tank must then be bottomed out which involves the removal of that quantity of petrol and deposits which remain below the pump suction pipeline, using a hand pump or a flame-proof electrical pump. This procedure should be performed by a specialist contractor
    3. the atmosphere in the tank must inerted by means of nitrogen, nitrogen foam or carbon dioxide (see guidance on these inerting methods in HSE Guidance Note CS 15)
    4. disconnect all pipework entering the tank via the tank lid. Flush through and cap at each end all pipelines previously connected to the tank or compartment
    5. remove the tank lid. (It should be remembered that this can be a hazardous exercise unless great is care taken.) In the case of old tanks without tank lids the suction pipe should be unscrewed leaving a hole approximately 75mm through which slurry of a thin consistency can be poured
    6. the area surrounding the tank as far as boundaries permit should normally be classed as a hazardous area whilst filling the tank is taking place and all necessary precautions should be taken to prevent any source of ignition
    7. fill the tank with 20 to 1 mix of concrete slurry. Wherever possible the slurry should be assisted to the extremities of the tanks by means of a vibrating device. (It is important to remember the previous point). It is essential that a Petroleum Officer of the Trading Standards Service is in attendance when the slurry fill takes place. Only when the slurry filing has been completed to the satisfaction of the Petroleum Officer is the manhole chamber to be filled with concrete

Removal of tanks

Before excavation work starts, any tank to be removed from the ground should be rendered safe.

For a tank without leaks the following initial procedure should be followed:

  1. drain all pipelines associated with the tank and remove all residual petrol
  2. the tank must then be bottomed out which involves the removal of that quantity of petrol and deposits which remain below the pump suction pipeline, using a hand pump or a flame-proof electrical pump. This procedure should be performed by a specialist contractor
  3. fill the tank or compartment with water to ensure a liquid seal
  4. disconnect all pipelines (except vent pipes) and add water to the tank or compartment until clear water appears at the vent pipe opening
  5. cap or blank off all openings to the tank or compartment
  6. flush through and cap at each end all pipelines previously connected to the tank or compartment

Excavation work should be carried out with the tank in the filled condition and with suitable precautions to avoid sparks. When the tank is ready for lifting, any water used should be emptied and all openings immediately closed. Water should be disposed of by a hazardous waste disposal contractor.

Alternatively, the tank may be rendered gas free by the internal application of an inert gas by a competent person and the following procedure applies:

  1. tests by a competent person should be carried out to determine if the tank is free of flammable vapours. If so, a gas free certificate should be issued
  2. if a tank is certified as being gas free of flammable vapours it may be taken out of the ground within 24 hours of the issue of the certificate

Drain back all pipelines associated with the tank and remove all residual petrol.

The tank must then be ‘bottomed out’ which involves the removal of that quantity of petrol and deposits which remain below the pump suction pipeline, using a hand pump or a flame-proof electrical pump. This procedure should be performed by a specialist contractor.

For a tank with leaks, all residual petrol should be removed, and the tank bottomed out and the atmosphere in the tank inerted by means of carbon dioxide, nitrogen or nitrogen foam. (See guidance on these inerting methods in HSE Guidance Notes CS 15).

Inerting should be maintained during the excavation process any fault in the tank shell should be sealed as soon as it is exposed and the atmosphere in the excavation should be monitored throughout the process in case of leakage of inert gas or of the presence of a flammable atmosphere arising from petrol leakage.

Any excavated tank should be indelibly marked on two sides with the words PETROL – HIGHLY FLAMMABLE in letters not less than 50mm high and should be water filled or remain inerted, as appropriate, pending disposal.

Disposal of tanks

Any tank which has been removed from its excavation should be disposed of safety as soon as possible. Preparation for and removal by road should be in accordance with the provisions of the current legislation in force at the time.

The person responsible for removal of a tank from a filling station should ensure that the recipient of the tank is made aware of the tank’s previous use and of the need to take adequate precautions against fires and explosions when dealing with it.

Cleaning or demolition of any tank on site should not take place without the agreement of the appropriate authority.

The location of any abandoned tank should be recorded in the site register and brought to the attention of any person who subsequently becomes responsible for the site.

Further the Trading Standards Service should be made aware of the final destination of any tank which has been removed from the ground.

Alternative use of tanks

The tank may be used for the storage of diesel or gas oil providing the petrol tank has had all residual of petrol removed from it, and been bottomed out (which involves the removal of that quantity of petrol and deposits which remain below the pump suction pipeline, using a hand pump or a flame-proof electrical pump.) This procedure should be performed by a specialist contractor.

The tank must be filled totally in order to dispel any petroleum vapour. It is important to remember to drain down the pump and pipelines thereby removing all petrol before introducing an alternative fuel

Notification to the licensing authority

The Petroleum Officer of the Trading Standards Service must be advised on which course of action it is proposed to take to render a decommissioned tank safe and can be in attendance when tanks are filled.

The Importance of Maintaining Commercial fuel tanks

The Importance of Maintaining Commercial fuel tanks

There are a wide range of uses by companies for commercial fuel storage tanks. Companies may have a commercial fuel-oil or gas tanks on premises that are used to power equipment and vehicles, or heat offices and various other buildings.

Storing large amounts of fuel on premises is of course not without its risks. Fire is the main and immediate concern due to fuels’ highly combustible nature. Potentially a devastating accident waiting to happen, by law measures must be taken to prevent any such incident occurring.

Commercial fuel tanks can prove to be an environmental hazard if they start to leak and the fuel spills out and seeps into the ground, possibly contaminating water supplies and putting the owner at risk of costly legal action and clean-up costs.

Over time without regular maintenance tanks will become polluted with water, bacteria, and particles such as dirt and sludge. This will clog-up filters and contaminate further supplies of fuel. This dirty fuel will pose risks to where it will be used: either in heating systems, standby generators or vehicles, causing damage that could be expensive to repair, and cause detrimental down-time.

So, to eliminate these risks and to keep use of commercial fuel tanks and their contents efficient it makes sense to schedule regular maintenance. It will also help keep companies in line with regulations concerning the use of commercial fuel tanks.

It’s possible to clean fuel tanks and the fuel they contain, whilst they are still in use using filtration and various other methods. Meaning there is no risk of disruption to the use of your fuel tanks for your company; so it can be business as usual.

In addition, firms stand to also gain from tank maintenance because regular work and any repairs that are required will extend the life of their tanks, negating the need to replace them prematurely with expensive new ones.

Fuel stored in large quantities are hazardous elements, but if properly looked after and maintained, fuel storage tanks will provide years of efficient use and service; preventing environmental or even human casualties and helping your firm to get the most out of its heavy investment in the fuel necessary to keep it running.

DP FTS helps revamp a Victorian villa

DP FTS helps revamp a Victorian villa

When Martin Clowes needed to refurbish and extend a Victorian villa in Epsom, Surrey, he decided to call in the experts to remove a redundant 3,000ltr heating oil tank in the shape of DP Fuel Tank Services  (DP FTS).

Says former building services engineer Martin Clowes: “The removal was going to be tricky and have a number of associated risks, so I knew it was going to require a specialist company.

“DP FTS was very easy to find on Google and its web site had all the information I needed. A web enquiry resulted in someone coming back to me within 24 hours, the job was started in just three days and concluded it in the time specified.

“I was very impressed with the way the operatives carried out the work, their safety procedures were very good and I felt they could be left to get on with their job.”

The tank had been installed in the old coal house in such a way that there was no room around it, so it had to be cut up into manageable sections to remove it from the house. DP FTS first cold cut an access hole into the tank so residual fuel could be removed and the inside thoroughly cleaned to remove all traces of flammable liquid, so the rest of the tank could be hot cut into sections.

DP Fuel Tank Services are proud to have sponsored Ashley & Jennifer Scott

DP Fuel Tank Services are proud to have sponsored Ashley & Jennifer Scott

DP Fuel Tank Services are proud to have sponsored Ashley & Jennifer Scott on their mammoth expedition from London to Mongolia! Quite an undertaking for any professionally-equipped adventurer in a Land Rover; but Ashley & Jennifer have traversed over 6,500 miles to reach the Capital, Ulaanbaatar, in their clapped-out £500 Nissan Micra! They endured sandstorms and forded rivers with their car breaking down at every opportunity! Along the way, they replaced tyres, engine hoses, patched the radiator and used old rubber found by the side of the road to reinforce the rear suspension springs! All they had available were some basic Halfords tools and a lot of elbow grease! Well Done guys!

They have raised nearly £3,000 for the Great Ormand Street Hospital and Plant Earth charities.

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Christmas 2015

Christmas 2015

For the first few years David Plumb & Co Ltd was run from a semi-detached house in Coulsdon. Then, in 1971, he and his family took over the tenancy of a service station in Lower Kingswood, Surrey. While continuing to run the forecourt as a going concern, hosting a car sales and repair operation, and even selling second hand furniture, its large amount of land and out-buildings provided room for the tank cleaning vehicles and equipment.   In 1987 David’s daughter Kathy joined the business followed by her brother Nigel in 1991. When David retired, these siblings took over as directors, along with long-time employee John Moore.

Cleaning and lining the tank below the car park

Cleaning and lining the tank below the car park

Says Nigel Plumb:

“Over the years, the size of the tanks we work on has expanded. We have used the skills we gained working on service areas to clean and/or remove tanks up to 5,000,000 litres, carrying out work for power companies and the MOD in locations as far away as the Falklands.” At the other end of the spectrum, DP FTS has expanded into cleaning, removing and installing domestic and commercial heating oil tanks. One of its diversifications is the offering of ultrasound testing, which detects if tanks are thinning in a particular spot, which is likely to lead to a leak in the future. Where leaks have occurred it can deal with decontamination and tank relining, or even site decommissioning and demolition.   Says Nigel Plumb: “As you can see, we have, over the years diversified into numerous areas, but these have always been a natural evolution from our roots as a tank cleaning company. Evolution, of course, never stops, and now we are looking at ways of adapting our services still further to meet the constantly changing needs of the industry. “While we will always work on forecourts, our next evolution, over the next 50 years, will be dictated by what the market needs.  Our skills have already taken us into areas that no one would not have dreamed of back in 1966. Today, if someone says, ‘Can you do it?’, the answer is usually, ‘Yes we can’.”

SNV36607 web

Reducing Lorry Queues on M20

DP Fuel Tank Services (DP FTS) has been helping Ashford International Truckstop (AIT) to do its part to help alleviate some of the problems caused by recent channel crossing delays, resulting in lorries having to park on the M20 under Operation Stack.   Fuel tank specialist DP FTS was called in by the truck stop to clean seven underground storage tanks on the 25-year-old site, just off junction 10, to create 64 new parking spaces.   The full task involved five 53,000 ltr tanks, one 39,000 ltr and one 13,000 ltr tank. All had to be thoroughly cleaned and water sealed, which means they can be safely left in the ground.   Before any cleaning could be done, 5000ltr of diesel and gasoil had to be pumped into tankers and DP FTS’s strategic partner TVP had to disconnect all pipework to give DP FTS safe access to the tanks.

DP FTS helps reduce lorry queues

DP FTS helps reduce lorry queues

DP Fuel Tank Services (DPFTS) has been helping Ashford International Truckstop (AIT) to do its part to help alleviate some of the problems caused by recent channel crossing delays, resulting in lorries having to park on the M20 under Operation Stack.

Fuel tank specialist DP FTS was called in by the truck stop to clean seven underground storage tanks on the 25-year-old site, just off junction 10, to create 64SNV36607 web new parking spaces.

The full task involved five 53,000 ltr tanks, one 39,000 ltr and one 13,000 ltr tank. All had to be thoroughly cleaned water sealed, which means they can be left in the ground but are in all ways safe.

Before any cleaning could be done, 5000ltr of diesel and gasoil had to be pumped into tankers and DP FTS’s strategic partner TVP had to disconnect all pipework to give DP FTS safe access to the tanks.

Says DP FTS site supervisor Gary Reeve: “Unfortunately we chose the wrong days, as there was torrential rain throughout, resulting in groundwater coming into the access chambers, which we had to pump out through the site’s ground water interceptor. It was so bad that we had to keep the pumps going constantly throughout and install a water seal to keep the tanks dry once we had finished.”

Adds Darren Smith, general manager of AIT: “We had been using another company to deal with our fuel site issues, but we were not satisfied, so we put the job out to tender. DP FTS came across well, its methods suited us and the price was a good one. The previous company took three weeks to clean the tanks, DPFTS did the whole thing in three days.

“We had had a string of problems with the old fuel site, “continues Darren Smith, “and to bring it up to scratch would have needed considerable investment.

“There was lots of competition in the area from service stations so we were making very little profit on fuel, it didn’t really even pay the wages. So we decided to decommission.

“There was also a call by the Government and Kent County Council for more lorry parking, following the problems with Operation Stack and we like to help where we can. Decommissioning meant we could add a further 64 parking spaces, which easily brought in more income.”

When the work is finished, the site will have a total of 325 parking spaces and a few bedrooms for change-over drivers. AIT also has a 24-hour bar/restaurant, a gym and is five star rated for security and facilities.