Senversa Pty Ltd
Ground Floor, 51 Clarke Street, Southbank Vic 3006
ABN 89 132 231 380 www.senversa.com.au
S11345_003_LTR_Rev0_Summary 25 February 2016
Page 1 of 1 Commercial in Confidence
25 February 2016
Ms Joanna Lamb
NSW Environment Protection Authority
Level 13, 10 Valentine Avenue
Parramatta NSW 2124
Dear Joanna,
Re: Brief Overview of Results for Orica Mercury Independent Review: Stage 3
Environmental Health Risk Assessment
Senversa Pty Ltd was engaged by the NSW Environment Protection Authority (EPA) to conduct Stage
3 of the Orica Mercury Independent Review. The Stage 3 works comprised an Environmental Health
Risk Assessment (EHRA) of potential community exposure to mercury originating from Orica’s former
Chlor Alkali Plant (FCAP) at Matraville during its operation from 1945 until 2002.
The EHRA1 reviewed the information and data collected during Stages 1 and 2 of the Review, and
considered potential health risks to receptors within approximately 1.5 km of the FCAP, including
nearby residents and users of the Penrhyn Estuary. The EHRA was undertaken as a Tier 1, or
screening level, risk assessment. This involved comparison of measured mercury concentrations in
environmental media (soil, sediment, air and fish) to appropriate risk-based screening criteria
published by Australian and international regulatory agencies.
Key findings and conclusions of the EHRA were the following:
 The quantity and quality of data collected during Stages 1 and 2 of the independent review were
considered adequate to characterise levels of mercury in the environment to which the community
may be exposed, and therefore adequate to undertake the EHRA.
 Mercury was detected in all environmental media investigated, however at concentrations below
adopted risk-based screening criteria.
 Measured concentrations in environmental media were consistent with those reported due to
background urban sources (e.g. fossil fuel combustion, waste incineration and industrial
emissions) in cities within Australia and internationally.
 Health risks to the community due to mercury contamination from the FCAP and/or from other
background sources of mercury were classified as acceptable in accordance with Australian and
international regulatory guidance, and are not discernibly higher than expected for the general
public in urban areas of NSW.
The full EHRA report should be referenced for further details, assumptions and limitations.
Yours sincerely,
Victoria Lazenby Kristi Hanson
Senior Associate Environmental Health Scientist Principal Risk Assessor
KH/VL/JC
1 Senversa, 2016. Tier 1 Environmental Health Risk Assessment, Orica Botany Independent Review – Stage 3. 24 February 2016.
https://www.epa.nsw.gov.au/working-together/community-engagement/community-news/orica-botany-bay-incident/orica-botany/independent-review-orica-botany/independent-review-stage-three