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On-Farm Diesel Storage: Tanks, Compliance and Harvest-Season Planning
A farm burns most of its diesel in a few busy weeks and stores it for the rest of the year. The tank has to cover the first and survive the second.
- Sizing
- Tank Type
- Siting
- Fuel Quality
On-farm diesel storage should be sized for the busiest stretch of the season, usually harvest or seeding, not for an average week. Work out how much the whole fleet burns per day at the peak, multiply it by the days a delivery can take to arrive at that time of year, then add a margin and the volume the pump cannot draw. The tank type follows from where it sits. A single skin tank needs separate bunding around it, while a self-bunded tank carries its own containment. Between seasons, the same fuel can sit for months, so filtration, water control and testing matter as much as capacity. Storage of diesel is addressed by AS 1940 alongside state and local requirements, and what applies depends on the quantity and the site.
Running out of diesel in the middle of harvest is the most expensive way a farm can buy fuel. The header stops, the trucks queue, and the delivery you ring for is competing with every other property in the district doing exactly the same thing. On-farm storage is the answer to that, but only if it was sized for that week and kept in condition for the months before it.
This guide covers how to size a farm tank from the season rather than the average, how to choose between single skin, self-bunded and mobile storage, where to put it, and how to keep diesel usable through the quiet months.
Peak week The number that sizes a farm tank. The annual average hides the harvest spike
4,500 to 28,000L The A-FLO Farm Refueller range, in six capacities for properties of every size
10 micron Filtration with water separation, standard across the Farm Refueller range
Why Farm Fuel Is a Seasonal Storage Problem
A transport depot uses roughly the same amount of diesel every week. A cropping farm does not. Seeding and harvest pull more fuel through the tank in a few weeks than the rest of the year combined, then demand drops to a trickle of ute, pump and spraying work.
That pattern creates two problems that pull in opposite directions. In the peak, the tank has to be big enough that the machinery never waits for fuel. Out of the peak, a tank that is big enough for harvest holds fuel that may sit for months, collecting water and ageing, until the next busy period draws it all at once.
| What changes |
In the peak |
Between seasons |
| Fuel use |
Headers, tractors, chaser bins and trucks running long days |
Light use by utes, pumps and occasional plant |
| Main risk |
Running dry while a delivery is days away |
Fuel sitting for months, collecting water and sediment |
| Delivery |
Slower, because every property wants fuel at once |
Easier to schedule, and a chance to buy well |
| What matters most |
Capacity, flow rate and refill access |
Filtration, water control, monitoring and testing |
Sizing the Tank for the Season
The common mistake is to size from annual consumption divided by the number of deliveries a year. That number is fine for a depot. On a farm it produces a tank that is comfortable in winter and empty halfway through harvest.
List the machinery that runs in the peak
Headers, tractors, chaser bins, trucks, loaders and pumps. Include contractors' machines if they refuel from your tank, because they usually do.
Work out the daily burn at the peak
Last season's fuel dockets and meter records are the best source. If the tank has no meter, the delivery history across the busiest month is the next best thing. Use real figures for your machines rather than a rule of thumb.
Find the delivery lead time in that season
Ask your fuel supplier how long a delivery takes to arrive at harvest, not in an ordinary week. Remote properties and wet roads lengthen it further.
Multiply, then add what the pump cannot reach
Daily burn multiplied by lead time is the usable fuel you need on hand. The draw point sits above the floor of the tank to stay clear of water and sediment, so the volume below it does not count.
Add a margin and round up
A breakdown, a late delivery or a run of perfect harvesting weather all use fuel faster than planned. Round up to the next tank size rather than the one that only just covers the arithmetic.
A worked example
Suppose the fleet burns 1,500 litres a day at the height of harvest, and the supplier needs five days to deliver in that season. That is 7,500 litres of usable fuel. Allowing for the volume below the draw point and a margin for a slow delivery takes the requirement towards 9,000 litres, which points to a tank in that class rather than a smaller one that runs dry on day four. The figures are assumptions for the example. Use your own records.
Single Skin, Self-Bunded or Mobile
Once the size is known, the choice of tank comes down to where it will sit and what it has to do. A-FLO's farm and agricultural diesel tanks cover all three situations.
Fixed, with a bund
Single skin steel
The Farm Refueller range is heavy-duty single skin steel from 4,500 to 28,000 litres. A single skin tank in a fixed installation needs compliant external bunding, which A-FLO can advise on.
Fixed, no bund
Self-bunded
A double-walled tank carries its secondary containment with it, so there is no bund to build. Fuelcube steel tanks and self-bunded Poly Refueller tanks suit a site where building one is impractical.
Lighter duty
Poly tanks
Single skin Poly Refueller tanks run from 3,000 to 10,000 litres, with self-bunded versions at 5,000 and 10,000. Lighter than steel and simple to place.
In the paddock
Fuel trailers
When machinery works far from the shed, fuel trailers and mobile refuelling take the diesel to it, so the header is not driven back to fill up.
Single skin versus self-bunded is mostly a question of whether a compliant bund already exists. Where it does, a single skin tank inside it is a straightforward choice. Where it does not, a self-bunded tank removes the question and the earthworks. Self-bunded vs poly diesel tanks compares the materials in more detail, and moving fuel by road is covered in diesel fuel trailers and how much diesel you can legally transport.
Where to Put the Tank
The best farm tank sites share a few practical features. None of them replaces the requirements that apply to your property, but each one makes the tank easier and safer to live with.
- Tanker access in all weather. The delivery truck has to reach the fill point at harvest, and after rain. A site that is only reachable on a dry day is the wrong site.
- Machinery access without congestion. Headers and trucks should be able to pull up, fill and leave without reversing round each other or the tank.
- Away from drains, dams and waterways. A spill should stay where it can be cleaned up, not run downhill into a creek.
- Protected from impact. Machinery, trucks and livestock all hit things eventually. Bollards or a fence around the tank are cheap insurance.
- Firm, level and shaded where possible. A stable base keeps the tank sound, and shade reduces the daily temperature swing that drives condensation.
Keeping Diesel Clean Between Seasons
A tank sized for harvest spends much of the year holding fuel it does not need yet. That is when water gets in and sediment settles, and the first long run of the next season is when it all gets drawn into the machines. A-FLO's guides on how long you can store diesel, water in diesel and diesel bug explain the chemistry. On a farm the practical answer is a handful of habits.
- Filter on the way out. The Farm Refueller range comes with 10 micron filtration and water separation, so what reaches the injectors has been cleaned first. Fuel filtration explained covers what the ratings mean.
- Drain the water. Water settles at the bottom of the tank. Check for it and drain it on a schedule, rather than waiting for a filter to block.
- Manage the level in the off season. Buy for the season ahead rather than leaving a large volume sitting for months, and keep the tank sealed so it breathes in less moist air.
- Test before the peak. A fuel test before seeding or harvest tells you whether the diesel that has been sitting is fit to use, at the one time of year you cannot afford to find out the hard way.
- Clean on a schedule. Diesel tank cleaning and maintenance sets out what an inspection and clean involves, and A-FLO's service and maintenance team offers tank cleaning and fuel testing.
The quiet months are the time to service
Filters, water drains, tank cleaning and calibration are all easier when the tank is low and nobody needs fuel. Book them for the weeks after harvest, not the week before it.
Knowing What Is in the Tank
Farm tanks are often a long way from the house, and nobody wants to climb one with a dipstick in the middle of a harvest day. Tank level monitoring reports the level remotely, and automatic tank gauging with a high-level alarm helps prevent both run-outs and overfills. The larger Farm Refueller installations are offered with both.
Metering matters too. The Farm Refueller range is offered with digital and mechanical flow meters, and a fuel management system goes further by recording who drew fuel, into which machine and when. On a property with contractors and several operators, that record is often the only way to know where the fuel went.
Compliance
Diesel is a combustible liquid, and its storage is addressed in Australia by AS 1940, alongside state and territory work health and safety and environmental requirements and local council conditions. What applies to a farm depends on how much is stored, how it is contained and where the tank sits. This article does not state quantity thresholds, separation distances or bunding specifications, because they depend on the property and the jurisdiction, and they change.
A-FLO's plain English guide to AS 1940, EPA and council approvals and the article on council or EPA approval for an above-ground diesel tank set out where to start. Confirm the position for your own property before the tank is ordered.
What Goes Wrong
- Sizing from the annual average. It produces a tank that is fine in winter and empty mid-harvest.
- Using an ordinary week's delivery time. At harvest, every property in the district is ringing the same supplier.
- Forgetting the contractors. If they fill from your tank, they are part of the daily burn.
- A single skin tank with no bund. The tank is only half of a compliant fixed installation.
- Filling up in autumn and leaving it. A full tank of fuel nobody needs for months is a water and sediment problem in waiting.
- No meter and no monitoring. Leaks, theft and plain miscounting all go unnoticed until the tank is empty.
- A site the tanker cannot reach after rain. The fuel is in the truck, the truck is on the road, and the header is still waiting.
Frequently Asked Questions
What size diesel tank do I need on a farm?
Size it from the busiest period of the year, usually harvest or seeding. Multiply the whole fleet's daily diesel use at that peak by the number of days a delivery can take to arrive in that season, then add the volume below the draw point and a margin. Round up to the next tank size.
Does a farm diesel tank need to be bunded?
Diesel storage needs secondary containment, and what applies depends on the quantity and the site under AS 1940 and state and local requirements. A single skin tank in a fixed installation needs a separate bund around it. A self-bunded tank carries its containment in a second skin, so no bund has to be built.
Should I choose a single skin or a self-bunded farm tank?
If a compliant bund already exists where the tank will sit, a single skin tank inside it is a straightforward choice. If it does not, a self-bunded tank avoids building one. Mobile work away from the shed is better served by a fuel trailer.
How long can diesel be stored on a farm?
It depends on temperature, water, the air space in the tank and the fuel itself. Diesel that sits between seasons should be filtered on the way out, checked for water on a schedule and tested before the next busy period, rather than assumed to be fine because it looks clear.
Where should a farm fuel tank be located?
Somewhere a tanker can reach in all weather, machinery can fill without congestion, spills cannot run into drains, dams or waterways, and the tank is protected from impact. The requirements that apply to your property sit on top of that, so confirm them before the tank is placed.
How do I stop water getting into my farm diesel tank?
Keep the tank sealed, avoid leaving a large volume sitting for months, and site it in shade where possible to reduce condensation. Water that does get in settles at the bottom, so check for it and drain it on a schedule, and filter with water separation on the way to the machines.
What sizes does the Farm Refueller come in?
The Farm Refueller range runs from 4,500 to 28,000 litres in six capacities. The tanks are single skin steel with 10 micron filtration and water separation, and are offered with 240V pump packages, flow meters, automatic tank gauges and high-level alarms.
Do I need council approval for a diesel tank on my property?
It depends on the quantity, the tank and the jurisdiction. Diesel storage is addressed by AS 1940 alongside state and territory requirements and local council conditions. Check with your council and state regulator before the tank is ordered.