Assessment of public health risk from the remediation of the former Fruitgrowers Chemical Company site, Mapua: challenges and lessons learned Wasteminz Conference October 2010 Dr Jill Sherwood Nelson Marlborough DHB Public Health Service
Feb 22, 2016
Assessment of public health risk from the remediation of the former Fruitgrowers
Chemical Company site, Mapua:challenges and lessons learned
Wasteminz Conference October 2010
Dr Jill SherwoodNelson Marlborough DHB Public Health Service
Outline of Presentation
Background and context of the investigation
What we found
Conclusions
Challenges
Lessons learned
Background
Site activities Pesticides factory,
mineral processing plant, private landfill
1932 – 1988 Site left “orphaned” Historic
contamination Environmental and
public health risk assessed in 1990s
Remediation planned
Location of Mapua Site
Protected disclosure
Mapua Site remediation commenced 2004Concerns raised about remediation process 2006Agencies involved in investigation
Parliamentary Commissioner for the Environment, Ministry of Health, Department of Labour
Public Health Service involvement Requested to undertake investigation for MoH
Public Health Brief
Investigate the possibility of risk to public health
Risk of exposure to any emissions and discharges
Risk to health of the population From the start of the remediation
Approach
Information gathering Identify possible hazards Resource consent conditions for protection of public
health and review of monitoring results Community concerns
Risk assessment of hazards of concern Chemicals included in the total hazard index other hazards if health impact appeared possible
Hazards
In the soil or groundwater Testing prior to remediation Baseline sampling early in the remediation Unexpected finds during the remediation
Resulting from the remediation process By-products formed in soil dryer By-products formed in MCD reactor
Other Dust Noise and/or vibration Odour
Exposure Potential
Summary as how hazards might leave the Site Stack emissions Fugitive emissions Groundwater discharges
Site activities during remediation (early 2007)
Treated “fines”
Issues re Exposure Information
Monitoring not all contaminants of concern monitored PM10 not monitored PUF filters not suitable to measure TSP Tahi Street monitoring station location No background monitoring station
Modelling OCPs – poor correlation Dioxins – uncertainty due to assumptions in
model
Conclusions
Risk if Site left unremediated OCP exposure - soil and marine environment
OCPs reduced to acceptable levels in soilPublic health risk resulting from remediation
Low – negligible for a few chemicals during remediation Low and manageable for a few chemicals post
remediation Unknown for a few chemicals – expert advice
recommended on further environmental/biological testing
Noise and vibration – nuisance/irritation
Public Health Risk During Remediation
Contaminant Exposure Health RiskPM10 (Likely) numerous (Likely) low-medium
Ammonia (Likely) low (Likely) very low
Dioxins(period of concern Nov 04-March 06)
Probable Unknown
PCBs (non-dioxin like) Possible Unknown
Benzene Possible Unknown
OCPs, arsenic Low (north and west of Site)
Possible (south of Site)
NegligibleUnknown
OCPs groundwater Drinking water – UnlikelyIrrigation - Possible
NegligibleUnknown
OCPs shellfish Unlikely (notices in place) Negligible(notices in place)
Public Health Risk Post Remediation
Contaminant Exposure Health Risk
Ammonia in soil on Site Unlikely Site tests show very low levels
OCPs in soil on Site Possible for DDX (await testing)
Uncertain (await testing)
OCPs groundwater Drinking water – UnlikelyIrrigation - Possible
NegligibleUnknown
OCPs shellfish Unlikely if advisory notices in place
Negligible if notices in place
Challenges
Complexity of the science
Missing historical data
Lack of / poor quality monitoring data
Incomplete temperature records for dryer
Community concern - keeping them informed
Range of agencies involved in investigation
Lessons learned for future similar projects
Have flexible approach – recognise may need to adaptShould have Peer Review Panel to oversee project with appropriate range of skills for the projectMedical Officer of Health or representative should be on panelBe aware of potential and risk from fugitive emissions when remediation site is in residential areaRobust Proof of Performance testing under normal operating and site conditionsA statutory review condition in all consents that includes:
“Reviewing monitoring requirements”
Acknowledgements
• My colleagues at Nelson Marlborough DHB Public Health Service: Dr Ed Kiddle and Geoff Cameron
• Dr Deborah Read, Ministry of Health