Expert Soil Testing & Management Plans for DA Approvals in Coastal NSW

Confluence Environmental provides acid sulfate soil (ASS) assessments and management plans across Newcastle, Lake Macquarie, and the Hunter Coast. If you're developing near estuarine areas, low-lying floodplains, or reclaimed land, your DA may require an ASS investigation as part of council or NSW planning approvals.

We help identify risk early, test your site, and develop fast, compliant solutions that keep your project on track.

Do You Need an Acid Sulfate Soil Assessment?

If your site falls within an ASS risk zone (Class 1–5) on the NSW Acid Sulfate Soil Planning Maps, your local council will likely require:

• A preliminary desktop assessment, and

• If risk is confirmed, an Acid Sulfate Soil Management Plan (ASSMP)

This is especially important for:

• Subdivisions, earthworks, or excavation

• In-ground infrastructure installation (stormwater, pipes, footings)

• Marine or waterfront developments

• Excavation below 1m AHD or near wetlands or creeks

We work with developers, planners, architects, and builders to ensure that site risks are clearly understood and that your DA or EPA requirements are met.

Our Newcastle & Lake Macquarie ASS Services

Desktop Risk Screening
– Review of planning maps, elevation models, and geology
– Assessment of disturbance depth and triggers

Soil Sampling & Field Testing
– In-situ sampling, pH and pH-KCl screening
– Chromium Suite laboratory analysis (TAA, SCr, ANC, Net Acidity)

ASS Management Plans (ASSMPs)
– Site-specific risk analysis and oxidation potential
– Management strategies aligned with NSW Acid Sulfate Soil Manual
– Controls for excavation, dewatering, lime dosing, and disposal

Council-Ready Reporting
– Comprehensive documentation accepted by Newcastle City Council, Lake Macquarie Council, and NSW Planning bodies

Remediation Oversight
– On-site support during excavation
– Validation sampling and post-management verification

Why Acid Sulfate Soils Are a Risk in Newcastle & Lake Macquarie

Coastal developments across Newcastle, Belmont, Warners Bay, and Swansea often encounter naturally occurring acid sulfate soils. When disturbed and exposed to oxygen, these soils generate sulfuric acid, leading to:

• Structural damage to concrete and steel

• Pollution of groundwater and waterways

• Harm to aquatic ecosystems

• Increased remediation costs if not identified early

We help you detect, manage, and prevent these impacts with fast, scientifically robust reporting and hands-on remediation advice.

Our 5-Step ASS Assessment Process

1. Map Review & Desktop Risk Assessment

2. Field Sampling and pH Screening

3. Chromium Suite Laboratory Analysis

4. ASS Management Plan Preparation

5. Validation & Council Submission

Where We Work

We service all areas in Newcastle and Lake Macquarie including:

• Newcastle CBD, Carrington, Mayfield, and Wickham

• Lake Macquarie LGA: Warners Bay, Cardiff, Belmont, Toronto, Swansea

• Surrounding coastal and estuarine suburbs with mapped ASS risk

Why Choose Confluence Environmental?

• Deep understanding of NSW coastal planning regulations

• Fast turnaround with council-ready documentation

• Field and lab experts in Chromium Suite analysis and pH management

• Trusted by developers, surveyors, planners, and local government