By: Duane Pretorius, Environmental Manager – Sedgwick Australia

Incident summary

Sedgwick responded to a third-party contamination claim resulting from an insured trailer collision that caused an 800-liter diesel spill. The spill impacted a 912 m² tar road, two drain inlets, and a 130-meter stormwater drain line. Quick responses from the local fire department (Fire Rescue Victoria) and city council mitigated immediate risks.

Containment and cleanup

The city council blocked drains with sand to prevent diesel migration into nearby wetlands. The insured authorised a waste and spill management service for the initial cleanup. Vacuum vehicles removed 198 tonnes of contaminated water from stormwater pits and disposed of it at an Environment Protection Agency (EPA)-approved facility.

Environmental consultation

External environmental consultants engaged by Sedgwick conducted stormwater and surface water sampling, which revealed elevated diesel concentrations that needed to be cleaned again. The relevant state environmental authorities issued strict notices to the insured, which activated legal obligations under the Environment Protection Act 2017, the general environmental duty (GED) as well as the EPA’s publication 1991 (responding to harm caused by pollution). Sedgwick initiated a comprehensive and phased approach in line with regulatory requirements. It included:

• Phase 1: Containment measures and initial cleanup, including the removal of contaminated water.
• Phase 2: Sampling drains and outlets, removing additional contaminated water, and reporting to the EPA, including requesting discharge consent to dispose of contaminated water down a sewer system.
• Phase 3: Implementing trade waste permit, filtration and water treatment in the stormwater drain. Containing and removing sand berm with a vacuum truck and disposing of it at an accredited facility. Lastly, ensuring the drain was clean and free of contamination by performing a ‘flush and wash.’
• Phase 4: Project completion, final inspection, reporting and closeout.

Alternate solutions

Upon identifying light non-aqueous phase liquid (LNAPL) remnants, Sedgwick explored alternative disposal options to remove the estimated 120,000 litres contained in the stormwater drain pipeline. A certified environmental practitioner facilitated communications with environmental authorities and the wastewater treatment facility and secured consent for sewer discharge. Strict requirements led to the engagement of a specialist water treatment company to execute the filtration and containment of the sediment to ensure a safe discharge.

Savings and contributions

Investigating alternatives and obtaining a trade waste discharge permit reduced costs by $170,000. Originally quoted at $280,000, the disposal of additional contaminated water was successfully executed at $110,000. Sedgwick’s involvement demonstrated efficient process management by minimising high-cost disposal and exploring alternative treatment options, resulting in significant cost savings.

Conclusion

Sedgwick successfully challenged conventional disposal methods and offered a viable, legal and cost-effective alternative. The treatment approach of the additional 120,000 litres of contaminated water prioritised lower
carbon emissions. This case underscores the importance of proactive stakeholder engagement and informed emergency response in ensuring favourable outcomes are reached in hazardous substance incidents.