Fuel Polishing Services
CSG provides fuel polishing services for commercial and industrial organisations that rely on stored diesel, biodiesel and heating oil to keep critical equipment operating reliably. By removing suitable contaminants and improving fuel cleanliness, fuel polishing can help reduce the risk of breakdowns, costly repairs and unexpected downtime.
Stored fuel doesn't stay in perfect condition forever. Over time, contamination can build up inside fuel tanks, including water, sludge, sediment and microbial growth, all of which can affect fuel quality and increase the risk of equipment problems when the fuel is eventually used.
We help organisations protect stored fuel quality and reduce the risk of contamination-related equipment failures.
90+
Years
supporting industrial facilities and critical infrastructure
How Does Our Fuel Polishing System Work?
Tell us about the fuel or oil, storage tank, approximate volume and any signs of contamination. We review your requirements and agree any sampling or testing needed to assess whether polishing is suitable.
We then confirm the treatment method, access arrangements and project scope before scheduling attendance. Where suitable, fuel is circulated through filtration and water-removal equipment on site.
Any tank cleaning, waste removal and checks on treated fuel are agreed as part of the project scope, together with advice on managing future contamination.
Fuel Sampling & Testing
Identifying contamination issues before they start affecting equipment performance
Fuel Polishing
Removal of contaminants including water, sediment and sludge to help restore fuel quality
Diesel Bug Assessment
Investigation of microbial contamination within stored diesel and biodiesel systems
Compliant Waste Removal
Waste materials can be managed through compliant treatment, recovery or disposal routes where required
What You Can Expect From Our Fuel Polishing Service
Fuel polishing can improve the cleanliness of suitable stored fuels by removing water, sediment and fine particles. Where the fuel remains suitable for its intended use, this can help reduce unnecessary disposal, replacement costs and operational disruption.
Our service supports commercial and industrial fuel storage systems, with specialist industrial oils considered following assessment. The recommended approach depends on the material, contamination, tank condition and intended use.
- Support for diesel, biodiesel, heating oil and specialist industrial oils
- Compact towable rig designed to minimise disruption on site
- Advice on fuel storage best practice and contamination prevention
- Water, sediment and fine particle removal, with filtration possible down to 1 micron
Polishing may need to be combined with tank cleaning, sludge removal or other corrective work. We assess these requirements before agreeing the scope.
OUR CREDENTIALS
Built On Recognised Standards
Quality, environmental, and safety credentials supporting our fuel polishing and associated waste management services.
DNV-Certified
Quality, Environmental & Health and Safety
SAFE Contractor
SSIP Accredited
Achilles UVDB
Category B2 Assessment
CHAS
Accredited
JOSCAR
Registered Supplier
CIWM
Affiliated Member
Who We Support
Our fuel polishing services support organisations across a wide range of sectors, including:
Manufacturing & Industrial
Protecting standby generators, operational equipment and critical infrastructure
Healthcare & Critical Infrastructure
Supporting sites where reliable backup power systems are essential
Data Centres
Helping maintain fuel quality for emergency power generation systems
Transport, Logistics & Fleet
Supporting organisations managing larger fuel storage systems
We’ll help you assess your stored fuel and identify suitable polishing or other treatment options. Speak with our team
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Frequently Asked Questions About Fuel Polishing
What fuels can you polish?
We can support a range of stored fuels and oils, subject to assessment, including:
- Â Diesel
- Biodiesel
- heating oil
- generator fuel stocks
- other commercial or industrial oil storage systems.
Specialist industrial oils may also be suitable for polishing where contamination involves water, sediment or fine particles. Suitability depends on the material, its condition, the equipment requirements and its intended use.
How do I know if my fuel is contaminated?
Fuel contamination isn’t always obvious, particularly in the early stages.
Common signs can include:
- Water present in the tank
- Increased filter changes
- Poor equipment performance
- Blocked fuel lines
- Dark or stringy material within the fuel
- Unusual sediment build-up
Sampling and testing can often identify issues before visible signs develop.
What are the benefits of fuel polishing?
Fuel polishing can help improve fuel quality by removing contaminants such as water, sediment and fine particles. Where the fuel or oil is recoverable, it may help reduce waste, avoid unnecessary disposal and replacement costs, protect equipment and minimise operational disruption.
How often should fuel polishing be carried out?
The right frequency depends on factors such as fuel age, storage conditions, tank design and operational requirements.
Sites relying on critical backup systems often choose to include fuel testing and polishing as part of a planned maintenance programme.
What is the diesel bug and how can I tell if my fuel is contaminated?
The Diesel bug is a term used to describe microbial contamination that develops in stored fuel systems.
Microorganisms can grow where water is present within the tank, forming sludge and biofilm that can block filters, fuel lines and equipment components.
What causes the diesel bug in storage tanks?
The diesel bug typically develops when water enters a fuel storage system.
The water creates an environment where microorganisms can grow and multiply, particularly in tanks where fuel remains stored for extended periods.
How does fuel polishing help reduce the risk of the diesel bug?
Fuel polishing can remove water and suspended contamination that contribute to microbial problems in stored fuel.
However, polishing alone may not remove deposits or biofilm attached to tank surfaces, or resolve the source of water ingress. Depending on the findings, tank cleaning, specialist microbial treatment and improvements to storage conditions may also be required.
Do you need to drain the storage tank for fuel to be polished?
Not necessarily.
The most appropriate approach depends on the condition of the fuel or oil, the tank configuration, access requirements and the level of contamination present. Our team can assess the system and recommend the most suitable next steps, which may include polishing, dewatering, tank cleaning or removal of contaminated material.
How often should I check my fuel storage tank for contamination?
The frequency will depend on the importance of the fuel system, storage conditions and how long the fuel is typically stored.
For critical systems such as standby generators, periodic testing can help identify issues before they affect performance.
How do you treat or manage the diesel bug once detected?
The most appropriate solution depends on the extent of the contamination and the condition of the fuel system.
This may involve fuel polishing, removal of contaminated material, tank cleaning or other corrective measures depending on the findings of the assessment.
Is this service suitable for domestic fuel tanks?
This service is for commercial and industrial fuel storage systems. It does not cover domestic heating-oil tank polishing.
For a commercial or industrial enquiry, please provide the fuel type, approximate volume, tank details and any known contamination so we can assess suitability.
Can fuel polishing remove water from oil or fuel?
Yes, where the material and treatment method are suitable. We assess the type and extent of water contamination before recommending a process.
Free water, emulsified water and dissolved water can require different treatment approaches. We confirm what the proposed process can achieve rather than assuming that polishing will remove all water contamination.
How fine is the filtration process?
Filtration down to 1 micron may be available, depending on the fuel or oil, contamination and agreed requirements.
The filtration rating alone does not confirm that fuel is suitable for use. Any required testing and acceptance criteria are agreed as part of the project scope.
Is fuel polishing the same as tank cleaning?
Fuel polishing treats the stored fuel by removing suitable contaminants through filtration and water removal. Tank cleaning addresses accumulated residues and deposits inside the tank.
Some projects require both, particularly where sludge or contamination remains on tank surfaces. We assess the fuel and storage system before recommending the appropriate scope.
Can all contaminated fuel be made suitable for reuse?
No. Suitability depends on the fuel’s condition, the contamination present and the requirements of the equipment it will supply.
Polishing can remove suitable physical contaminants, but it should not be assumed to resolve every fuel-quality problem. Assessment and appropriate testing help determine whether polishing is suitable or whether another treatment or disposal route is needed.
Get a Free Waste Management Audit
The easiest way to start improving your waste management is with a Free Waste Management Audit from CSG. Our team will assess your current waste streams, identify opportunities to reduce costs and make practical recommendations to improve how you manage your waste.
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Discuss Your Fuel Polishing Requirements
Tell us about your commercial or industrial fuel storage system, the postcode of your site and any contamination or equipment concerns. Include the fuel type, approximate volume and any available test results, where known. Our team will assess whether polishing is suitable and discuss any tank cleaning or further treatment required.
For urgent enquiries, call 0800 011 6600.