Erosion and sediment from your business activities can harm human health and the environment. It's important to find ways to eliminate, reduce and control erosion and sediment.
Business activities that expose soil or take place on exposed soil increase the risk of erosion and sediment. This includes:
- building and maintaining roads, rail, bridges, utilities, drainage, embankments and clay dams
- excavating, stockpiling, handling and transferring material
- managing catchments
- rehabilitating land.
Industries that need to manage erosion and sediment include:
- agriculture and forestry
- bulk material suppliers
- construction, infrastructure and land development
- earthworks
- landscaping
- mining and quarrying
- water suppliers.
Manage risks from erosion and sediment
To meet the general environmental duty, you must eliminate or reduce risks from erosion and sediment so far as reasonably practicable.
Follow a risk management process to identify hazards, assess risk, and implement and monitor controls.
You're responsible for the activities of tradespeople or contractors you hire.
Control erosion and sediment
Before you put controls in place, consider your approach to site planning and management.
The controls you put in place depend on your business activities and the kinds of erosion and sediment they cause.
Preventing erosion and sediment is the best approach. If you cannot prevent it, minimise and manage erosion and sediment.
Controls to reduce risk from erosion and sediment include:
- covering exposed construction surfaces with geotextiles
- managing soil disturbance
- managing stockpiles
- managing truck and other vehicle movement
- managing how you work within or adjacent to waterways
- managing offsite flows – for example:
- directing water around or away from exposed soil areas, stockpiles, embankments or sensitive receivers
- using downslope water diversions
- perimeter structures – for example:
- silt fences or barriers
- check dams
- coir logs
- earth contour banks
- protecting existing drainage systems – for example, using:
- coir logs
- culvert gravel filters or rock logs
- engineered drainage systems with flow-slowing or load-management measures
- slowing wind or water flow rates – for example, using:
- baffling systems
- erosion matting
- rock armouring
- shelter belts
- wind fences.
You can use a treatment train to combine multiple controls. Some controls can only deal with coarse or fine sediment.
You may also need to control dust from your business.
You can use other controls not listed here. You must show us you've eliminated or reduced the risk of harm as far as reasonably practicable.
You may need advice from a qualified consultant, such as an environmental consultant.
For more information about controls, visit International Erosion Control Association Australasia.
Report an erosion or sediment incident
If your business has caused an incident that harms or threatens to harm human health or the environment, you must report it to us as soon as you become aware of it.
If you hold a permission, you must notify us immediately if you breach any condition of your permission. This includes notifying us about any incident that harms or threatens to harm human health or the environment.
Respond to erosion and sediment complaints
To respond to erosion and sediment complaints about your business:
- identify the source of the erosion or sediment
- investigate the cause
- check your controls and continually apply your risk management process
- keep people who made the complaint informed, where you can.
Keep a record of the complaint details to help you identify the cause and improve your controls. Records can include:
- the name, address and contact number of the person who made the complaint
- wind direction and speed
- rainfall
- temperature
- time of day
- water quality monitoring data
- what you were doing at the time
- what you've done to fix the problem.
Examples: how to manage erosion and sediment
These examples show how you can apply a risk management process to manage erosion and sediment. Use them as a guide only. Your business may need more or different controls – for example, dust controls – depending on your site.
Construction projects
Ahmed works for a construction company that operates in busy areas with heavy vehicle and foot traffic. His role involves site planning. He knows it’s important to understand how construction activities can harm people and the environment.
Know the source of the sediment
Ahmed knows that water flowing across disturbed ground on a site can move sediment. This is a hazard because:
- sediment can enter stormwater drains and waterways
- sediment can impact the health of people, plants and aquatic life downstream, especially if it contains contaminants.
Assess risks from sediment
Before any job starts, Ahmed assesses the drainage across the site. He considers:
- the amount of rainfall
- proximity to local waterways and stormwater drains
- the likelihood of flooding.
Ahmed also assesses the nature of the site surface, including:
- soil types
- potentially contaminated soils
- surface slopes
- vegetation cover
- depth to groundwater.
Control and manage risks from sediment
Ahmed then identifies controls to prevent erosion and the transport of sediment. Ahmed decides to use swales to divert rainwater away from exposed soil onsite.
For more complex site conditions, Ahmed calls on the expertise of an environmental consultant.
Monitor and review controls
Ahmed regularly checks each control is working as intended. As conditions on the site change, Ahmed reassesses:
- what hazards he has identified
- the controls he has in place.
Quarrying
Leah is an environmental officer with a quarrying company.
Know the source of erosion and sediment
Leah knows that rainwater and water from dewatering and other sources can cause surface run-off and erosion off site. Water can collect sediment, nutrients and other contaminants as it travels across a site. It can enter the drainage system and waterways. From there, it can impact the health of people, plants and aquatic life downstream.
Control and manage erosion and sediment
Leah plans the site layout so that stockpiles are located away from waterways and floodplains.
Leah designs the site's water management requirements to separate dirty water from non-dirty water. This minimises water coming into contact with mining activities.
Leah identifies other controls, including:
- contouring and minimising the length and steepness of stockpile slopes
- installing bunding at wash-down facilities to capture wastewater
- managing road drainage
- replanting disturbed areas
- seeding or mulching soil stockpiles
- staging vegetation clearing and earthworks to minimise the surface area of exposed land.
She also includes controls based on rainfall and water flows.
Monitor and review controls
Leah's company routinely inspects and de-silts their drainage system and their erosion and sediment control structures.
Before a high-rainfall event, they:
- increase inspections
- monitor water discharge against their licence requirements.
This helps them understand if their controls are effective or if they need to modify them.
Leah is confident they are removing or reducing risk well, because they follow regulatory requirements and relevant guidance.
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