What Is a Weed and Seed Declaration?
A weed and seed declaration is a biosecurity document that confirms your vehicles, plant, and equipment are free from soil, plant material, seeds, and other biological contaminants before entering or leaving a site.
Why It Exists
Invasive weeds cost Australian agriculture billions of dollars every year. Construction and civil works are one of the biggest vectors for spreading them.
When your excavator moves from one region to another, any soil or plant material stuck to the tracks, undercarriage, or bucket can carry weed seeds, pathogens, and pest insects into a new area.
The core purpose is simple: prevent the spread of weeds and contaminants between sites. You inspect and certify that your gear is clean before it moves.
The Legal Basis
Weed and seed declarations aren't just pushed by overzealous site managers. They're backed by real legislation.
- Biosecurity Act 2015 (Commonwealth) - establishes the national framework for managing biosecurity risks, including movement of potential carriers
- General Biosecurity Obligation (GBO) - if you know, or ought to know, your activities could pose a biosecurity risk, you must take reasonable steps to prevent it. Moving dirty equipment is a clear breach.
- Land Protection (Pest and Stock Route Management) Act 2002 (QLD) - specifically targets management of declared pest plants
- State Biosecurity Acts - each state has its own legislation imposing obligations on people moving vehicles and equipment
Ignorance isn't a defence. If your gear introduces an invasive species to a new area and you didn't take reasonable steps to prevent it, you're liable.
When Do You Need One?
You'll typically need a weed and seed declaration in these situations:
- Moving vehicles or plant between sites - especially across regions or between properties with different land uses
- Entering mining, gas, or resource sites - almost always mandatory. They won't let your gear through the gate without one.
- Council and government contracts - frequently specified in contract conditions
- Regional and rural work - any work near agricultural land, waterways, or national parks
- Agricultural or pastoral land - protecting crops and livestock from invasive species is taken very seriously
- Any site with a biosecurity management plan - the plan specifies requirements, and you must comply
If you're in civil, earthworks, mining, or utilities, you'll encounter these regularly. Even general construction in regional areas is starting to require them.
AHCBIO203 Certification
On many sites, particularly mining and resource sites, the person completing the inspection needs an AHCBIO203 certificate (Inspect and Clean Machinery and Equipment to Remove Weed Material).
What the Course Covers
- Identifying declared weeds
- Understanding the inspection process
- Applying correct cleaning methods
- Completing documentation properly
Without it, your declaration may not be accepted. You could be turned away at the gate.
If you regularly work on sites requiring declarations, get at least one person on your crew certified. Some sites accept self-declarations from non-certified personnel, but the trend is moving toward requiring the formal qualification.
What to Inspect
A proper weed and seed inspection is thorough. You're not doing a quick walk-around. Check every area where soil, seeds, or plant material can accumulate.
Tyres, Tracks, and Wheels
- Tyres - mud packed into tread patterns, grass and seeds lodged between treads, soil on sidewalls
- Tracks (tracked machines) - soil between track pads, plant material in track links, mud behind sprockets and idlers
- Wheel arches - a major accumulation point. Mud and plant material build up and stay for months if not cleaned
Undercarriage
- Chassis rails and cross-members - caked soil and mud on every flat surface
- Axles, differentials, and driveline components - soil wraps around these and hardens
- Guards and splash shields - trap soil and debris behind them
Engine Bay and Radiator
- Radiator and condenser - seeds, chaff, and fine plant material get sucked into radiator fins by the cooling fan. Commonly missed.
- Air intakes and filters - seeds accumulate in air intake ducting
Trays, Toolboxes, and Load Areas
- Tray floors and sides - loose soil, gravel contaminated with seeds
- Toolboxes - soil tracked in from gloves and tools
- Tie-down points and channels - small amounts of debris accumulate in recesses
Cabin Interior
- Floor mats and footwells - soil from boots, grass and seeds tracked in
- Pedals and foot areas - mud from boots
- Behind and under seats - loose soil and plant material
- Door seals and channels - seeds lodge in rubber seals
Footwear and Personal Gear
- Boots - mud on soles and in tread, seeds caught in laces
- Clothing and personal mats - burrs, seeds, and soil carried on work gear
Recording the Previous Site
An often overlooked part of the declaration is recording where the vehicle or equipment came from.
The risk profile changes depending on whether your gear was last working on agricultural land, a known weed-infested area, near waterways, or on a clean urban site. Receivers use this to assess biosecurity risk.
Be honest about this. If your excavator spent the last two weeks on a rural property, say so. Lying doesn't protect you - it exposes you to greater liability if a problem emerges later.
Cleaning Methods
If your gear needs cleaning before it can pass, three methods are standard:
- High-pressure wash - the primary method for removing caked soil, mud, and wet material. Focus on the undercarriage, wheel arches, tracks, and recessed areas. Use a designated washdown bay where possible.
- Air blow-down - compressed air for dry conditions. Effective for blowing seeds, chaff, and dry plant material out of crevices, radiator fins, and cabin areas. Often used as a follow-up to pressure washing.
- Manual clean - scraping, brushing, and hand-removal for stubborn material in hard-to-reach areas. Important for material packed into track links, behind guards, and in chassis recesses.
Always inspect again after cleaning. A clean that looks good from a distance might still have seeds in track links or soil behind brackets. Get close and check properly.
What Counts as Contamination
To be clear about what you're looking for:
- Soil and mud - any soil attached to the vehicle, regardless of whether it visibly contains seeds
- Seeds and seed heads - including grass seeds, declared weed seeds, and unidentified seed material
- Plant material - leaves, stems, root fragments, bark, grass clippings
- Organic debris - decomposing plant matter, mulch, straw
- Insects - some sites require checking for pest insects in areas with active management programs
If you find any of these, it must be removed before the declaration can be completed as a pass.
Pass, Conditional, and Fail Outcomes
A declaration results in one of three outcomes:
Pass
The vehicle, plant, or equipment is clean. No soil, seeds, plant material, insects, or organic debris found. Clear to enter the site.
Conditional Pass
Minor contamination found that can be cleaned on the spot. Examples:
- Small amount of dry soil that can be brushed off
- A few grass seeds on floor mats
- Minor dust in the radiator that can be blown out
The item passes once contamination is removed and confirmed clean.
Fail
Significant contamination that cannot be adequately cleaned on site. Examples:
- Wet soil packed into tracks
- Heavy mud on the undercarriage
- Large amounts of plant material
- Identified declared weed species present
The vehicle must be taken to a washdown facility, cleaned thoroughly, and re-inspected before it can enter the site.
A fail means your gear isn't going through the gate today. That's downtime, transport costs, and a washdown fee - all avoidable by cleaning before you left the previous site.
Supplier vs Receiver Responsibilities
Both parties have obligations:
The supplier (you, sending the equipment) is responsible for ensuring vehicles and equipment are clean before they leave your site. Complete your own washdown and inspection during demobilisation.
The receiver (the site you're entering) is responsible for verifying equipment meets their biosecurity requirements before granting access.
Best practice: clean as you leave each site, not as you arrive at the next one. Make washdown part of your demobilisation routine and you'll never be the crew standing at the gate waiting for a pressure washer.
Consequences of Getting It Wrong
Skipping or faking a declaration isn't just a paperwork issue.
- Biosecurity fines - under state and Commonwealth legislation, penalties can reach tens of thousands of dollars for individuals and significantly more for businesses
- Site access denied - you and your gear get turned away. Your crew stands around while you find a washdown facility.
- Contract penalties - many contracts include specific penalty clauses for biosecurity non-compliance. Repeated failures can result in termination.
- Environmental damage liability - if your gear introduces an invasive species, remediation can cost hundreds of thousands of dollars, and you may be liable
- Reputation damage - word travels fast in regional areas. If you're the contractor who brought Parthenium weed onto a cattle property, you won't be called back.
Make It Part of Your Process
Keep a checklist in each vehicle. Run through it every time you move between sites. It takes 10 minutes to inspect and 30 minutes to clean - a lot less time than being turned away.
Burgy includes digital weed and seed declarations with guided checklists, photo evidence capture, previous site recording, and auto-calculated pass, conditional, or fail outcomes.
You know the result before you get to the gate. Every declaration is stored with the vehicle's history automatically.