Acid Sulfate Soil Assessments and Management Plans (NSW)

If your project involves excavation, dewatering, drainage works or construction on low-lying coastal or floodplain land, acid sulfate soils can quickly become a cost, compliance and program risk. Poorly understood acid sulfate soils can trigger approval conditions, spoil handling restrictions, environmental harm and expensive remediation.

Confluence Environmental provides practical, regulator-ready acid sulfate soil assessments and management plans across Sydney, Newcastle, the Central Coast and regional NSW. Our focus is on giving you clear, defensible advice that aligns with real construction works, not theoretical reporting.

If you need advice quickly, you can request a fast quote here: fast-quote or contact us directly at contact-us.

When an Acid Sulfate Soil Assessment Is Needed

We are commonly engaged when a council identifies potential acid sulfate soil risk, when excavation or drainage works are proposed in low-lying or estuarine environments, or when a project requires an Acid Sulfate Soil Management Plan to support development approval or construction.

This commonly applies to subdivisions, infrastructure works, trenching, service installation, dewatering, piling, or any activity that disturbs natural ground below the water table. Where acid sulfate soil risk overlaps with contaminated land requirements, further investigation such as a Preliminary Site Investigation may be required, see preliminary-site-investigation, or a Detailed Site Investigation, see detailed-site-investigation.

Acid Sulfate Soil Risk Assessment

We design investigations specific to your project conditions and proposed earthworks. This typically includes desktop assessment of environmental setting and disturbance triggers, targeted soil sampling aligned with excavation depth, field screening and soil profile interpretation, laboratory testing suited to decision-making, and clear conclusions on risk relative to construction activities.

Where required, results are used to develop a Conceptual Site Model and determine practical management requirements. For related terms see acid-sulfate-soils and conceptual-site-model.

Acid Sulfate Soil Management Plans

A well-prepared Acid Sulfate Soil Management Plan must be practical and aligned with construction sequencing. Our management plans typically include excavation staging, soil handling and segregation, stockpile controls, neutralisation and lime dosing methodology, groundwater and drainage considerations, inspection and hold points, contingency procedures and validation requirements.

Where broader environmental controls are required, acid sulfate soil measures can be integrated into an Environmental Management Plan, see environmental-management-plans.

Construction Support and Verification

For higher-risk projects we provide site support to ensure management measures are implemented correctly. This may include pre-start guidance, verification during excavation, monitoring where acid drainage risk exists and preparation of documentation for council, certifier or regulatory review.

Where groundwater or water quality monitoring is required, this can be coordinated as part of the overall management approach, see ground-and-surface-water-monitoring.

Why Clients Engage Confluence Environmental

Our work is focused on risk control and practical outcomes. We understand how acid sulfate soils interact with contaminated land, excavation, spoil handling and regulatory frameworks. Our assessments are clear, decision-focused and aligned with real project delivery, not generic templates.

Where excavation material reuse or waste classification is relevant, we can align acid sulfate soil management with broader soil classification and disposal pathways, see excavated-natural-material and waste-classification.

Who We Work With

We support developers, civil contractors, infrastructure projects, builders, planners and consultants requiring practical, regulator-ready acid sulfate soil assessment and management.

If you need a technical overview of environmental management approaches more broadly, see environmental-management-plans-nsw or remediation-and-validation-contaminated-land-nsw.

Service Area

We provide acid sulfate soil assessments and management plans across Sydney, Newcastle, the Central Coast, the Hunter Valley and regional New South Wales.

Speak With a Consultant

If your project involves excavation, drainage or development in an acid sulfate soil risk area, early assessment can prevent delays and unnecessary cost. To discuss your project or obtain a quote, visit fast-quote or contact contact-us.