Technical Guidance 39: Risk-based management and remediation guidance for benzo(a)pyrene

Mar 30, 2026

This report provides guidance on the risk-based management and remediation of benzo(a)pyrene (B(a)P)-contaminated sites. It provides information and a framework that will assist practitioners, regulators and site owners in effectively managing and remediating...

Technical Guidance 40: Weathered Petroleum Hydrocarbons (Silica Gel Clean-up)

Mar 30, 2026

This technical report has been prepared to review the available information on the presence of polar metabolite compounds in samples collected from weathered petroleum hydrocarbon–impacted soil and groundwater. The aim is to identify an appropriate silica gel clean up...

Technical Guidance 44: Technical measurement guidance for LNAPL natural source zone depletion

Mar 30, 2026

Natural source zone depletion (NSZD) is a term used to extend the traditional understanding of natural attenuation to the light non-aqueous phase liquid (LNAPL) source zone.

Technical Guidance 46: The role of natural source zone depletion in the management of light non-aqueous phase liquid contaminated sites

Mar 30, 2026

This report discusses a growing body of research showing that NSZD is ubiquitous at LNAPL sites. NSZD processes occur at all LNAPL sites to some degree and understanding, quantifying and evaluating their effectiveness is therefore an important part of a sustainable...

Technical Guidance 47: Australian case studies of light non-aqueous phase liquid (LNAPL) natural source zone depletion rates compared with conventional active recovery efforts

Mar 30, 2026

Natural rates of mass loss and biodegradation of light non-aqueous phase liquid (LNAPL) fuels and oils in soil and groundwater is termed natural source zone depletion (NSZD).