All stock must be kept out of landfill sites used to dispose of household and other food waste. Food waste containing or contaminated by animal matter (‘swill’) could spread an emergency animal diseases if it is eaten by certain kinds of livestock.
Many landfill sites are being converted to transfer stations, which usually satisfies animal security requirements if the stations are properly maintained. Where this is not possible, secure fencing is the preferred alternative to prevent stock accessing food waste.
Laws against feeding swill
Swill is food or food waste that contains:
- meat products
- milk or milk products not of Australian origin
- anything that has been in contact with the above items.
Feeding swill is illegal in Queensland and steps should be taken to prevent animals accessing swill contained in landfills or transfer stations.
Landfill and transfer station risk assessment
A risk-assessment process has been developed to classify landfills in relation to their potential for exposing animals to a possible exotic disease. Following a risk assessment, landfills and transfer stations are classified as high, medium or low risk.
The risk assessment considers:
- the potential for waste material in a landfill to contain contaminated material
- the potential for animals to be exposed to or get access to this material
- the influence of other factors (e.g landfill site management) on the overall risk.
The potential for food scraps contaminated with diseases such as foot-and-mouth disease increases where there is a higher probability of:
- the presence of illegal imports
- tourist-related food waste
- food from multiple origins waste (e.g. waste from schools, colleges, TAFE colleges, universities, restaurants and delicatessens).
Risk also increases when:
- waste is frequently left uncovered (rather than buried)
- a landfill is not staffed
- machinery used at a landfill site is also used near stock.
The risk of disease being transferred from a landfill increases when feral pigs are present in the area. Cattle, sheep and goats accessing landfills are also a high risk. Feral cats, dogs and birds are a lesser risk but can also transfer pathogens.
Machinery used at landfill sites
Machinery used in landfills receiving high-risk material should not be moved off site, especially not to properties running susceptible livestock, unless it has been adequately cleaned.
Changing a medium or high-risk landfill into a transfer station will, under normal circumstances, immediately decrease the risk to low. Well managed transfer stations markedly reduce the possibility of animals accessing swill. If it is not possible to convert a landfill to a transfer station, the next most effective exclusion technique is fencing the landfill.
Fencing the landfill
Fencing may be a better option if:
- the landfill is a long way from services or in a site that is difficult to access
- it is too expensive to change the site into a transfer station and collect rubbish.
The aim of the fencing is to exclude all animals, including feral pigs, from the site.
Eradicating feral pigs from the area would still be necessary to eliminate pigs that have a taste for the waste. If a reasonable fence already exists but is not feral-pig-proof, it can be upgraded using various elements from the recommended fence design. The preferred construction uses 8/80/15-type wire and a high -tensile barb near the bottom of the fence.
If a fence already exists that will keep out all stock except feral pigs, then, as a temporary measure, this fence may be able to be combined with a culling and monitoring program until a more permanent solution can be instituted.
A grid is needed at the entrance because a gate on a public landfill is likely to be left open.
Councils may elect to erect a fence with higher specifications than the one described below. One such fence is the chain wire type, of 1.8-2.4 m high, which may be used to exclude people and animals.
Recommended pig and cattle fence
A scientifically designed trial of 8 fence designs, with and without electric wires, was conducted to test their ability to stop feral pigs. The fence design shown below, with and without an electric offset wire, was the only design to completely stop pigs under trial conditions. The trial was conducted by Jim Hone and Bill Atkinson of the New South Wales Department of Agriculture. The information below relates to the brand, Waratah, and the comments on the durability are from a Waratah representative; however, there is no suggestion that this brand of wire has to be used.
Often landfill sites are unfenced or have an inadequate fence and so may require a new fence. This fence can have a dual role: excluding all livestock and feral pigs from the landfill as well as containing litter to the site. The presence of goats requires further assessment. Steel is recommended in preference to timber because of the high fire risk around landfills.
The recommended fence design to secure landfill sites from animals
- Steel strainer assembly: For permanent fences, concrete the strainer assembly in place
- Star posts at 5m spacing: 1.8m star posts at 5m centres are recommended. In some situations, Downs-type country where the soil is heavy, you may need to use wooden posts.
- In-line steel pipe/RHS posts: For permanent fences, a 2m steel pipe about 80nb or RHS of similar size should be concreted in the fence every 100 m. In Downs country you need the in-line steel pipe/RHS posts to be closer together. For temporary fences, wooden posts may be used instead of the pipe/RHS.
- 8:80:15 stocktite: Eight line wires and 15cm picket wire spacings make this a very strong fence. 2.8mm high-tensile wires at the top and bottom add strength where it is needed most. Long-life coating has up to 300% higher resistance to corrosion.
- 1.80mm high-tensile long-life barbwire: 1.80mm high-tensile barb as a bottom support wire adds strength but more importantly is a deterrent to pigs that try to get their snout under the bottom wire and lift it. Two high-tensile long-life barbs at the top add height and strength.
- 2.8mm high-tensile long-life support wire: 2.8mm high-tensile long-life support wire about 30cm from the ground adds extra strength. Extra strength is often needed here, as this is usually where the pig will try to break the fence once it has given up trying to lift the bottom wire.If an offset electric wire is run the need for this wire is diminished.
- Grid: A double-width grid (2m x 4.2m) is recommended at the site entrance as people fail to shut gates. Construct grids so pigs can't get between the strainer post and the grid. Any gates in the fence should have a concrete strip under them to prevent pigs entering.
- Galvanised star posts and galvanised steel pipe/RHS posts are recommended in wet areas.
Estimated fencing materials for a facility with 1 km perimeter
|180 cm star posts||190|
|1.8 mm high-tensile barb long-life||6|
|2.8 mm high-tensile wire long-life||1|
|117 cm droppers (45/bundle)||5|
|Star post clips (1500/bucket)||1|
|Steel strainer assembly||6|
Contact your preferred fencing contractor for cost.
Some large landfills cap the horizontal surface of the recently deposited waste daily but do not cap the face. Capping the face would help to exclude feral pigs and other livestock.
A pit with vertical sides may be one way of preventing access. Combine this with a firebreak around the pit, which will allow you to confirm whether pigs or other livestock have entered the area by finding tracks. Construction and operation need to conform to relevant workplace health and safety guidelines. Two potential problems mhere are:
- the risk of someone falling into the pit and not being able to get out
- the risk of pit walls caving in and burying someone alive.
Culling and monitoring animals
Culling and monitoring animal access is the least favourable option. This is because there is still a risk of stock, especially feral pigs, gaining access. There is also a significant labour component and so the possibility exists that monitoring will not continue at the landfill.
However, it may be the appropriate short-term option because of the lack of funds, intention to change to a transfer station within a short period, intention to fence the landfill in the near future or an intention to close the landfill. In instances where a culling program seems best, it is necessary to also conduct a monitoring program. A culling and monitoring plan and an auditable record of culling and inspections undertaken for feral pigs would be necessary at high-risk landfills.
This option concentrates on the control of feral pigs and would be used where feral pigs present a problem but where no other animals can get access or are prevented access. To initiate this option it is advisable to get advice from your local stock inspector. Biosecurity Queensland land protection officers can also provide assistance with formulating plans.
- The landfill operator should engage the services of a feral pig 'trapper/dogger' in order to determine whether pigs are on the site and to quantify the problem by using dogs. This should be conducted two to three times, randomly during nightfall, e.g. Tuesday 9 pm, Thursday 1 am, Sunday 11 pm. By using working dogs and spotlights, this consultant will obtain instant knowledge of whether pigs are harbouring in the area. The operator would have to be fully conversant withlegislation and codes of practice regarding use of dogs, traps etc.
- The code of practice states: The use of dogs to attack and bring down feral pigs is unacceptable. The use of dogs should be in the detection of animals and not be used to attack animals found.
- The Animal Care and Protection Act 2001 prohibits animal cruelty under:
- Section 18 (1) - A person must not be cruel to an animal.
- Section 18 (2) - Without limiting subsection (1), a A person is taken to be cruel to an animal if the person does any of the following to the animal:
- causes it pain that, in the circumstances, is unjustifiable, unnecessary or unreasonable
- abuses, terrifies, torments or worries it
- overdrives, overrides or overworks it
- unjustifiably, unnecessarily or unreasonably-
- injures or wounds it.
- Section 37 (1) - A person in control of an animal (the first animal) must not allow it to injure or kill another animal (the second animal).
- Use a dozer or loader to construct smooth pads approximately 4 m x 4 m at sites along the site's boundary. Set up pads at sites of pig movement to monitor feral pig activity.
- Keep the pads relatively smooth and soft and check regularly to identify any pig activity.
- Regardless of pig activity these pads should have some form of free feed material (e.g. grain or molasses) applied twice monthly. Apply the material to all pads. Monitor the pads regularly to see if feral pigs are consuming the bait material.
- If sites show some feeding, use feral pig traps with free feed until the animal is caught.
- Consult a professional trapper on the best bait material and trapping techniques.
- If no sign of feral pig activity occurs within the first two months of monitoring, this program could be reduced to one program per month (taking around two days to complete).
- Monitoring pads could be continued indefinitely as they are a good sign of pig presence. This will determine the need for and nature of further management.
- If pig numbers build up, notify the district's land protection officer to obtain further advice on possible control methods.
- Spotlight monitoring and the use of dogs could continue randomly during quiet periods to determine feral pig presence and behaviour.