Closed landfills were once used for waste disposal. Today, these sites in Redland City are closed, filled, and capped to prepare them for community use. This capping helps to contain any remaining waste and minimise environmental impacts, ensuring safe repurposing of the land for community activities.
Twenty-eight closed landfills on Redlands Coast are now sports fields, parks, BBQ areas, or public bushland. Using these sites for recreation is a positive and valuable use of land. For a list of closed landfill sites and current works please click here.
Contact with waste can pose risks. The key to minimising contact with buried waste is to protect the capping material, a responsibility that Council takes very seriously. Council ensures any potential environmental and health issues are addressed before these areas are opened for public use.
History and development of landfill sites
Before the 1980s, landfill sites were selected based on availability and convenience, often using quarries, wetlands, and vacant land. These sites did not meet environmental and engineering standards.
Today, landfill sites are carefully planned with consideration of geology, groundwater, and their surroundings. Engineers design them with liners to keep contaminants contained. Older sites lacked these features, so Council now works actively to prevent potential impacts.
(Diagram above: cross section of a closed landfill).
Benefits of a closed landfill
- Closed landfill sites can become places for sports fields, parks, BBQ spots, and nature areas that everyone can enjoy.
- Reusing this land means we don’t have to develop new areas, helping to preserve natural habitats and open spaces in our communities.
Challenges of closed landfill
Sometimes, older landfill caps can pose challenges because they weren't built with modern standards. This can lead to issues like:
- increased chance of water carrying contaminants (leachate) getting through.
- gases like methane can leak out if caps aren't sealed well, which can be unsafe.
- old caps can wear down overtime, causing the land to sink or become unstable.
To tackle these issues, Council monitor's landfill sites and make upgrades when needed to meet today's environmental standards. This helps keep our community safe and our environment healthy.
What is leachate
Leachate is water that has passed through landfill waste, picking up contaminants.
The risk from leachate varies with the type of waste. Council tests and controls leachate based on risk, using strategies like diverting stormwater, compacting waste, and capping landfills to reduce rainfall impact.
Old landfill sites pose more challenges due to inadequate historical practices. Council mitigates these risks with fences, warning signs, regular inspections, and prompt cleanup and repairs. This proactive approach ensures ongoing monitoring and maintenance to protect public health and the environment.
Closed landfill management
Council carefully monitors and improves closed landfill sites to protect the environment and keep our community safe.
Key measures include:
- implementing strategies to reduce leachate and environmental impacts by diverting stormwater, compacting waste, and capping landfills.
- monitoring landfill gas emissions, such as methane and carbon dioxide, to prevent fires, toxic exposure, and greenhouse gas emissions.
- managing waste decomposition to prevent land instability.
- safely containing hazardous substances to protect public health and the environment.
- using engineered materials to cap landfills properly, making them safe for community use like parks and playgrounds.
Monitoring, inspections, and reporting
Council monitors closed landfill sites in Redland City to ensure environmental safety through regular testing, immediate response to concerns, and comprehensive documentation of all activities. This includes:
- regular monitoring of closed landfill sites to ensure environmental safety.
- expert testing checks landfill gases, groundwater, and surface water in selected sites across Redland City.
- monitoring frequency varies based on the type of historical waste to manage risks effectively.
- immediate action is taken for any concerns like environmental issues or health risks.
- barricading is being put in place to protect the community from a known incident until it can be rectified by Council.
- a landfill remediation charge from Council rates funds essential tasks such as capping and managing gases.
- additional site inspections are conducted based on monitoring results, site activities, complaints, or changes in risks.
- all actions are documented, and significant incidents are reported promptly to the Environmental Regulatory Authority.
Legislative requirements
- Closed landfill sites are governed by the Environmental Protection Act 1994 (EP Act), State Government legislation that protects the environment in Queensland.
- All Council's closed landfill sites are listed on the Environmental Management Register (EMR).
- Four sites have an environmental authority, an approval to operate, as required by the EP Act.
- Compliance with the General Environmental Duty, licence conditions and producing site management plans where required.
Incidents and emergencies
If you notice any of the following incidents or activities at one of Council’s closed landfill sites, please don’t go near it and contact Council on 07 3829 8999 to report it and we will investigate:
- a spill or unauthorised discharge of a liquid, e.g. oil, petrol, diesel, sewage, paint, solvents, liquid waste or pesticides into a creek, waterway, wetland, drain or on a road or land
- potential environmental harm, e.g. dead fish in a waterway or unhealthy and dying plants
- evidence of contamination, e.g. an unusual colour, odour, temperature or floating matter
- potential for contamination, e.g. illegally dumped waste or spills
- evidence of air pollution, e.g. chemicals, unusual odours or sewage odours
- fire
- illegal dumping of solid or liquid waste, e.g. a waste tanker discharging into drains or creeks or dumping potentially contaminated soil.
Glossary of terms
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Leachate is water that has passed through waste material and picked up contaminants on the way.
To control leachate and reduce the chances of it occurring, Council has different mitigation strategies, such as diverting stormwater away from landfill sites, compacting waste material and capping landfills to reduce the effects of rainfall.
Old landfill sites have a greater risk of leachate from water travelling through the landfill, due to a historically poor understanding of the need for capping and drainage.
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Landfill gas, primarily composed of methane, carbon dioxide, and hydrogen sulphide, is a by-product of waste decomposition. While natural venting might not always be harmful, it is crucial to monitor gas emissions closely. Council ensures the safety of the community by diligently monitoring these emissions and installing gas vents. This proactive approach helps mitigate risks associated with landfill gas.
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Surface subsidence occurs when waste decomposes and reduces in volume, creating underground voids.
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A cap is a cover put over a landfill site to prevent people using it from being exposed to contaminants and to minimise water infiltration to reduce leachate generation.
Capped landfills can be used for community use, such as parks or playgrounds. Capping materials are generally compressed clay and topsoil.
Properly-engineered capping is used to minimise infiltration to prevent leachate and includes special liners and drainage material in addition to clay and topsoil.
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Batters are the sloped sides of a landfill.
