Effective Treatment Strategies for Acid Sulfate Soils in Western Australia: What Works and Why
Effective management of acid sulfate soils (ASS) is crucial to prevent environmental degradation, water contamination and structural damage. These issues can cause delays to your project, create compliance problems and may even require costly remediation works.
Implementing appropriate treatment strategies can mitigate these risks and promote sustainable land use. Importantly, they will also ensure that your operation falls in line with regulations set by the Department of Water and Environmental Regulation (DWER).
This article outlines the strategies we find to be the most successful for acid sulfate soil treatment and monitoring.
If you would prefer to speak directly with one of our environmental consultants, you can contact West Soil & Water at sam@westsoilandwater.com.au or on 0424 021 26.
1. Avoid Disturbing ASS
The most effective and economical strategy is to avoid disturbing ASS altogether. When left undisturbed in anaerobic conditions, ASS remains inert and poses no threat. Planning developments to steer clear of ASS-rich areas eliminates the need for further intervention.
2. Neutralise with Alkaline Materials
When disturbance is unavoidable, neutralising the acidity through the application of alkaline substances, such as agricultural lime, is a common practice. This treatment raises the soil pH, reducing acidity and preventing the mobilisation of harmful metals. The effectiveness of this method depends on accurate soil acidity assessments and precise application rates.
3. Strategic Reburial
Strategic reburial involves relocating disturbed ASS back into an anaerobic environment, effectively halting the oxidation process. This method requires careful planning to ensure that the reburied soil remains waterlogged and deprived of oxygen, thereby preventing further acid production.
4. Hydraulic Separation
Hydraulic separation techniques aim to remove sulfide minerals from the soil using water-based processes. By separating these minerals, the potential for acid generation upon soil disturbance is significantly reduced. This method is particularly useful in scenarios where soil excavation is necessary.
5. Controlled Dewatering and Drainage
Managing groundwater levels through controlled dewatering and drainage can prevent the exposure of ASS to oxygen, thereby reducing the risk of acidification. Implementing such measures requires careful design and monitoring to maintain appropriate water table levels and prevent unintended environmental impacts.
6. Ongoing Monitoring and Maintenance
Regular monitoring of soil and water conditions is essential to detect any changes in acidity levels promptly. Continuous assessment allows for timely interventions, ensuring that treatment strategies remain effective over time. This proactive approach is crucial for the long-term management of ASS.
West Soil & Water: Comprehensive Soil Monitoring in Perth
Implementing these treatment strategies requires a thorough understanding of site-specific conditions and potential risks. Engaging experienced environmental consultants, such as West Soil & Water, ensures that appropriate measures are tailored to each unique situation, promoting sustainable development and environmental protection. Our ASS services include:
Baseline Investigations: WSW carries out investigations to determine the presence, extent and severity of ASS on your site. This information is used as a foundation for future planning and monitoring.
Acid Sulfate Soil Management Plans (ASSMPs): We develop and implement ASSMPs to ensure potential risks are identified and managed proactively. These plans outline strategies for soil handling, treatment and monitoring throughout the lifecycle of a project.
Treatment and Monitoring: We tailor treatment solutions to the needs of your site and conduct ongoing monitoring to ensure their efficacy.
If you would like to speak with a member of our team about an acid sulfate soil occurence on your site, please contact WSW at sam@westsoilandwater.com.au or on 0424 021 26.
