Effective monitoring and reporting are critical components in the management of acid sulfate soils (ASS). ASS are naturally occurring soils rich in iron sulfides, typically formed in the waterlogged, anaerobic conditions found in Western Australia’s coastal regions and wetlands.
Undisturbed, ASS pose little to no threat. However, if they are exposed and able to oxidise, they will form sulfuric acid. This can cause significant damage to natural ecosystems and manmade structures.
In Western Australia, the Department of Water and Environmental Regulation (DWER) provides specific guidelines to manage ASS disturbances.
The surest way to comply with their regulations is to create an acid sulfate soil management plan (ASSMP) to assess risks, implement strategies and carry out ongoing monitoring.
This article will help you understand what the DWER requires and how an ASSMP can assist you.
If you would prefer to speak directly with an environmental consultant, please do not hesitate to contact West Soil & Water at sam@westsoilandwater.com.au or on 0424 021 264.
According to DWER, a development with potential ASS occurrence must implement an ASSMP if it involves:
Dewatering
Drainage
Excavation exceeding 100 cubic metres.
The ASSMP should detail strategies for monitoring and mitigating ASS disturbances that these activities may cause. Regular reports demonstrating compliance with your ASSMP should be submitted to DWER.
It is important to create a thorough, site-specific ASSMP, as an insufficient soil management plan will not help you prove compliance and will only result in penalties. You can read our article about common mistakes we find in ASSMPs.
DWER has also published several documents to assist you in maintaining your compliance. They are:
Identification and Investigation of Acid Sulfate Soils and Acidic Landscapes
Treatment and Management of Soils and Water in Acid Sulfate Soil Landscapes
Adhering to these guidelines is essential to keep up compliance and environmental protection in areas affected by ASS.
A robust, compliant ASSMP will include the following:
Baseline Assessment: Details of site investigations to establish pre-disturbance conditions of soil and groundwater. This includes sampling and laboratory analysis to identify existing acidity levels and the presence of sulfide minerals.
Ongoing Monitoring: Guidelines for a schedule to regularly monitor soil and water quality throughout the project’s duration. Parameters such as pH, redox potential and concentrations of dissolved metals should be measured to detect any changes promptly.
Data Recording and Reporting: A database of detailed records of all monitoring activities and results. Regular reports should be submitted to DWER, demonstrating compliance with the ASSMP and highlighting any deviations or incidents.
Contingency Planning: Procedures to address unexpected ASS disturbances or management failures. This ensures that appropriate actions can be taken swiftly to mitigate adverse effects.
You can read more about how WSW creates ASSMPs here.
It is critical to comply with DWER’s acid sulfate soils regulations to the best of your ability. This avoids unplanned fines and expenses, whilst ensuring project success and environmental stewardship.
Whilst you can create an ASSMP yourself, experienced environmental consultants such as WSW provide the expertise needed to develop and implement effective soil management plans.
We understand the unique environment of Western Australia and the intricacies of the regulations that protect it. Because of this, we are able to create effective strategies at a fair and reasonable price.
Aside from ASSMPs, our services include baseline investigations, treatment and monitoring. If you would like to speak to one of our environmental consultants about any of these services, you can contact us at sam@westsoilandwater.com.au or on 0424 021 264.
