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

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 2004 Concerns raised about remediation process 2006 Agencies 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 soil Public 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 ContaminantExposureHealth Risk PM 10 (Likely) numerous(Likely) low-medium Ammonia(Likely) low(Likely) very low Dioxins (period of concern Nov 04-March 06) ProbableUnknown PCBs (non-dioxin like)PossibleUnknown BenzenePossibleUnknown OCPs, arsenicLow (north and west of Site) Possible (south of Site) Negligible Unknown OCPs groundwaterDrinking water – Unlikely Irrigation - Possible Negligible Unknown OCPs shellfishUnlikely (notices in place) Negligible (notices in place)

Public Health Risk Post Remediation ContaminantExposureHealth Risk Ammonia in soil on SiteUnlikelySite tests show very low levels OCPs in soil on SitePossible for DDX (await testing) Uncertain (await testing) OCPs groundwaterDrinking water – Unlikely Irrigation - Possible Negligible Unknown OCPs shellfishUnlikely 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 adapt Should have Peer Review Panel to oversee project with appropriate range of skills for the project Medical Officer of Health or representative should be on panel Be aware of potential and risk from fugitive emissions when remediation site is in residential area Robust Proof of Performance testing under normal operating and site conditions A 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