iEnvironmental Principal Environmental Scientist provided environmental consulting services including removal, validation, and replacement underground petroleum storage systems (UPSS) including underground storage tanks (USTs). They used risk assessment, monitored natural attenuation and other strategies at several Council Depots in Central NSW, and remediated any associated contamination using a practical, safe and cost-effective approach.
Detailed assessment and remedial options assessment were provided more recently at one of the depots, to remediate and soil associated with a leaking UPSS. iEnvironmental selected a significantly less expensive approach that had not been put forward by competitors, including weekly manual bailing of the product by trained Council staff, which removed approximately 10% of the estimated product on groundwater in 1.5 years (more successfully than some alternative more expensive extraction methods).
Simple and Innovative Remediation, Risk Assessment, Vapour Assessment, Fate and Transport Modelling, Monitored Natural Attenuation
iEnvironmental conducted a risk assessment, aquifer pump test, and detailed geological assessment, indicating that dissolved hydrocarbons were reducing in lateral extent and concentration over time due to biodegradation to levels below the most sensitive potential future beneficial uses. Vapour risk was mitigated due to lithology at the site.
The multiple lines of evidence approach indicated through fate and transport modelling, that there were negligible current human health and environmental risks, and that future risks would be controlled through natural biodegradation of hydrocarbons and monitored natural attenuation, and an environmental management plan for the site, saving the client hundreds of thousands of dollars in remediation cost and management.