Guidance on Tank Cleaning for Tanks Containing Red Diesel

1. BACKGROUND

The Finance Bill 2021 and subsequent secondary legislation restricts the entitlement to use red diesel (Gas Oil) and rebated biofuels from 1 April 2022 to only the following:

For vehicles and machineryused in agriculture, horticulture,fish farming and forestry. Thisincludes allowing vehicles used foragriculture to be used for cuttingverges and hedges, snow clearanceand gritting roads

To propel passenger, freight ormaintenance vehicles designed torun on rail tracksfor heating and electricitygeneration in non-commercialpremises - this includes the heatingof homes and buildings suchas places of worship, hospitalsand townhalls; off-grid powergeneration; and non-propulsionuses on permanently- mooredhouseboats

For maintaining community amateur sports clubs as well as golf courses(including activities such as ground maintenance, and the heating and lighting of clubhouses, changing rooms etc.)

As fuel for all marine craft refuellingand operating in the UK (includingfishing and water freight industries),except for propelling privatepleasure craft in Northern Ireland

For powering the machinery(including caravans) of travellingfairs and circuses

Registered fuel suppliers that switch a fuel tank from red to white diesel will need to flush out the tank and supply lines until no trace of marked rebated fuel remains. This will help to ensure compliance and minimise the risk that white diesel that has had the full duty rate paid on it is contaminated with the red diesel marker.

(https://www.gov.uk/government/ publications/reform-of-red-dieselentitlements/reform-of-red-dieseland-other-rebated-fuels-entitlement)

Please note that this is NOT the end of red diesel, however its use is severely restricted from 1 April 2022.

This will mean that some end users and suppliers will need to cease use of red diesel and prepare their tanks to hold other fuels. It is essential to ensure that any evidence of the dye used as a marker in red diesel is removed. This will not be achieved without cleaning the tank and aggressively flushing the fill and delivery lines.

This guidance should ensure this can be done safely, with minimal risk of a fuel spillage and ensures that any waste (fuel and washings) is disposed of safely and in accordance with relevant legislation.

However, it is the duty of each tank owner to assess and manage the risks of the work being done, select appropriate, and qualified contractors and ensure that the work is conducted safely on their site and that waste is removed and disposed of in accordance with national and regional regulations.

2. PREPARATION

A. FUEL LEVELS

This work should be planned to ensure to fuel levels are decreased to minimise waste and that competent specialist contractors are booked and have time to plan and complete the work prior to the 1 April deadline.

Fuel levels should be reduced to 10% of tank contents. This should ensure any suction lines remain beneath the residual fuel level but importantly leave any sludge deposits within the tank. The sludges may contain bacteria, rust and other debris that builds up over time between cleaning intervals. Leaving it in the tanks prevent exporting potential fuel issues to a tanker, another tank or to a customer.

On the day of the work the contractor should have access to the tank lid, fill lines, delivery lines and vent lines as they will need to isolate the fill and delivery line.

With the tank content run down this is an ideal time to have any maintenance on this tank completed.

B. ACCESS TO THE TANK LID FOR ABOVE GROUND TANKS

If red diesel is held in an above ground tank, access to the tank lid should be managed to ensure it is safe as this will involve working from height. If there is no permanent access, such as a stairway with handrails, permanent ladder access to a platform with handrails around the tank lid, scaffolding may be required to be erected by an accredited scaffolding supplier. Prior to use any temporary scaffold should have a SCAFFTAG certificate attached to it issued by a competent scaffolding inspector.

NOTE: Manned entry should only be through a minimum 600mm diameter opening with breathing apparatus and trained personnel

C. MANAGE THE AREA OF WORK

Work on the tank may take several hours and possibly up to one day. It will release fuel vapours and involve the movement of liquid under low levels of pressure or vacuum. Barrier protection should therefore be available to segregate the work area to that of general site staff.

D. BRIEFING OF CONTRACTORS

The contractor’s work will involvethe transfer of fuel products andmovement of liquid under pressure orvacuum. Only Competent contractorsshould assess the risk of all plannedwork and produce method statementsand Risk Assessments (RAMS) todemonstrate how their staff willmanage the risks. These should beavailable to the tank owner for theirapproval prior to work commencing.Their trained and competent staffshould take due care but accidentscan happen. The tank owner shouldconduct a site induction to ensurethat the location of site drains,interceptors and spill kits arehighlighted as well as the availabilityof first aid kits, first aid trained staffand welfare facilities. This inductionshould enable the contractor toexplain how the work will be done.

3. TANK CLEANING

A. CLEANLINESS IS ESSENTIAL

The dye in red diesel is persistent and can be hard to remove from any tank that has stored red diesel for any length of time. To comply with legislation cleaning must be effective to prevent red dye being transferred to the next delivery of fuel put into the tank.

Before any works start an explosimeter test must be taken by an independent contractor/company to ensure the tank is Gas free (below 10% LEL) and a certificate issued which lasts for 24hours.

An ADR vacuum tanker with jet wash unit and hoses is generally sufficient to undertake the tank cleaning. However, all sludge in the tanks must be removed and all surfaces of the tank must be cleaned, which includes the roof. In larger tanks, particularly in old, pitted steel tanks and those with internal bracing, scrubbing with brushes and pressure hoses will be required.

In general, tanks over 20,000 litre capacity, where high pressure from a tanker jet wash unit may not reach each the end of the tank or the tank roof with sufficient pressure to remove the dye, then manned entry tank cleaning may be necessary. This will require a confined space man entry and can only be undertaken by specialist contractors who have the safe system of work to ensure this

high-risk work is safely conducted by trained technicians using Breathing Apparatus with the correct escape equipment in place.

In smaller tanks the operation will generally require two persons to complete safely, particularly when cleaning above ground tanks when the operative has to climb up a scaffold, stairway or ladder and work some distance from the tanker.

B. THE TANK CLEANING OPERATION

Using a vacuum tanker

i. Once the tank lid has been removed and a Gas free Certificate has been issued the contents of the tank should be checked to ensure fuel level and the fuel is that expected. At some point the tank may have been used to store other products which are more volatile and require specialist equipment and contractors to handle.

ii. Any fuel in the tank and the sludge in the base of the tank should be removed using vacuum suction hoses placed into the tank. Some lubrication using water from the jet wash unit is usually necessary. This needs to be continued until all of the sludge has been removed. Where there are persistent clumps of sludge these may need to be loosened using higher pressure jets of water.

iii. Once all of the tank base and ends of the tank are clearly visible the cleaning may commence. Using the jet wash unit to spray water in a systematic pattern along the length of the tank, including the roof, to wash the tank allowing water to collect in the base of the tank. Remove all liquid using suction hoses and repeat the process. It is important that all of the tank surface is washed several times to remove the residue of the dye.

iv. The operator should ensure that all water is removed. The tank owner should inspect the tank before the tanker leaves site to ensure all dye, sludge and water has been removed as water may contaminate subsequent deliveries of fuel into the tank.

C. USING A BUTTERWORTH OR ROTATING TANK CLEANING DEVICE

i. Some contractors may use a rotary tank cleaning device to undertake the cleaning of cylindrical tanks as the rotary head should ensure that all areas of a tank is washed.

ii. A rotary head is used in conjunction with a vacuum tanker and its suction hoses will remove the liquid used to undertake the clean and removal of the sludge on the base of the tank.

iii. Once rotary head cleaning has been completed it is important that all residual sludge and any liquid is removed.

iv. The tank owner should inspect the tank before the tanker leaves site to ensure all sludge and dye has been removed from the tank. He should ask the contractor for a Tank Cleaning Certificate.

D. FLUSHING OF FUEL DELIVERY LINE AND FUEL PUMP.

i. The fuel delivery line is hard to clean as it is difficult to remove water from them if that is used as the sole cleaning medium.

ii. Once the fuel line has been isolated from the tank, and the pump or end connection.

A vacuum tanker to flush the line with water until it runs clear of any dye.

iii. To remove any residual water in the line, flush with diesel until the fuel at the pump end of the line is clear and when left standing shows no presence of water in the fuel line.

iv. pump. Reconnect the fuel line to the

v. With the line still disconnected from the tank flush the pump through with diesel until the fuel from the pump start to clear.

vi. Change all pump filters and continue to flush the fuel line until all fuel delivered by the pump shows no red dye in the fuel.

vii. When this is the case reconnect the fuel line to the pump having changed any gaskets or seals.

E. FLUSHING OF FUEL FILL LINES

Repeat the above process for the fuel delivery line less the parts involving the pump.

Change any gaskets or seals on the fill line.

F. TEST THE INTEGRITY OF THE TANK, ITS FILL AND DELIVERY LINES

Once the tank, fill and delivery lines have been cleaned and are reconnected a pressure test of the tank, the fuel and delivery line should be conducted to check the integrity of the reassembled lines and tank prior to receiving a delivery of fuel. A certificate of integrity should be received from the company conducting the test.

G. WASTE DISPOSAL

Whichever method of tank cleaning is used, the disposal of waste is a critical part of the process.

All waste removed will include fuel, sludge and washings which must be treated as hazardous waste under Duty if Care paperwork and

be disposed of at a Licensed waste facility. It is the tank owner’s legal responsibility to ensure this, and the tanker company must be registered as waste carrier.

The tank owner should receive a hazardous waste consignment note from the carrier that states the volume and type of waste (identified in writing and with a waste code) removed from their site, the waste carrier and their registration number and the licensed waste facility where it is to be taken. In due course, the tank owner should receive notification from the waste site or the carrier that that the waste has been disposed of by the waste site.

4. REFILLING THE TANK WITH FUEL

Once the tank owner has confirmed the integrity of the tank then it is possible to organise the re-filling so that it may return to use.

The tank should be filled in the usual way.

However, it is likely that the pump will need to be primed and any air in the pump will need to be removed before it can commence delivery. This may need the pump specialist to attend to undertake this. (Note they may have been involved in the pump aspects of the tank cleaning operation)

If this is the case this is an ideal opportunity to check the calibration of the pump to ensure it is delivery correctly. If this is undertaken, then a calibration certificate will be issued.

5. DOCUMENTATION

As the work done is a requirement of an Act of Parliament the tank owner should retain documentation issued by the specialist contractors involved in this operation:

Tank Cleaning Certificate

Certificate of Integrity following testing at the completion of the tank clean and flushing of fill and delivery lines.

Hazardous Waste Consignment Note for all fuel, sludge and washings removed from site including proof of disposal.

Calibration Certificate (if fuel pump is recalibrated as part of this operation)

Gas free Certificate

RAMS