Innovative and cost-effective soil investigation, Sydney NSW

Innovative, cost‑effective soil investigation for inner Sydney parks

In early 2019 iEnvi completed preliminary site and shallow soil investigations at multiple recreational parks in inner Sydney prior to playground upgrades and installations. Historical review and initial soil sampling identified potential exposure of soils to contaminants within the last 50 years, and hydrocarbons were confirmed in shallow soils at two parks.

What we did

Our Environmental Scientists completed targeted shallow soil testing to assess contamination presence. Rather than immediately pursuing lengthy remediation or detailed environmental management planning, we designed a further targeted investigation to determine contaminant mobility and the actual risk to park users and construction workers.

Technical approach — leachate testing to assess mobility

We commissioned laboratory leachability testing on representative soil samples to determine whether the hydrocarbons were readily mobile under expected site conditions. The leachate testing indicated the hydrocarbons were effectively immobile in the tested soils, supporting the conclusion that the likelihood of contaminant migration to groundwater or exposure pathways for park users was negligible under prevailing conditions.

Outcome and commercial benefit

Because the leachate results demonstrated low mobility and low risk, the client was able to proceed with playground upgrades and installations at the affected parks without further remediation or an environmental management plan. This approach reduced program delays, avoided potentially significant remediation costs, and minimised construction complexity and on‑going compliance requirements.

Practical takeaways for councils and developers

• Early targeted testing and a clear objective (presence versus mobility) can save time and cost compared with defaulting to remediation.
• Leachability or mobility testing can be decisive where shallow contamination is detected but migration risk is uncertain.
• Risk outcomes depend on site‑specific factors (soil type, depth of contamination, groundwater depth and receptors); investigations should be tailored accordingly.
• Documented laboratory results and a concise risk assessment support defensible decisions for construction and approvals.

If this sounds like your project

For multi‑site council property risk assessments, playground upgrade projects or developer due diligence, contact iEnvi to discuss a pragmatic testing and risk pathway that can reduce time and cost while maintaining protection of park users and workers. Call us on 13000 43684 or visit /contact/ to request a confidential enquiry.