Cleanup of the Former FCC Pesticide Factory Site, Mapua: The End in Sight

Andrew Fenemor1, Jenny Easton1, Tony Cussins2

1 District Council, Private Bag 4, Richmond, Nelson (Andrew Fenemor is now with Landcare Research Ltd, Nelson, but retains a project management role) 2 Tonkin & Taylor Ltd PO Box 5271, Wellesley Street, Newmarket 1036

1. INTRODUCTION

The Fruitgrowers Chemical Company (FCC) site at Mapua has been described as New Zealand’s worst contaminated site. Council, with a Government funding contribution, has contracted Thiess Services/EDL to remediate the pesticide- contaminated soils and estuarine sediments over the next two years.

This case study summarises the history and status of the FCC site. We then identify the key communication tools used to obtain support for the project to this stage, and the risk communication challenges for the coming clean-up.

2. BACKGROUND

The FCC site occupies some 3.8ha of prime coastal land in the heart of Mapua village, between Richmond and . The Fruitgrowers Chemical Company pesticide factory operated from 1932 to 1988. FCC formulated over 100 different pesticides, including persistent organochlorines such as DDT and dieldrin which have contaminated the site and environs, the underlying groundwater and adjacent estuary. Since the plant began, the surrounding land has gradually been developed for residential land uses.

To undertake effective clean-up and avoid lengthy legal proceedings, Council negotiated to take over ownership of the whole site. This was completed in July 1996 after two years negotiations with Ceres Pacific and Mintech, who also contributed funding for site clearance and clean-up.

Site concentrations of contaminants, as sampled to date, far exceed levels considered acceptable for residential use and needed to protect the estuarine environment. Maximum (worst case) concentrations found on site are as follows:

Total Aldrin+ DDX dieldrin Maximum concentration (mg/kg) 11,560 200 Residential Soil Acceptance Criteria to 0.5m deep (mg/kg) 5 3 *DDX = total DDT, DDD and DDE.

In addition, soil contamination on Tahi St properties bordering the site slightly exceeds residential criteria. Exposures to DDT and dieldrin are possible from the ingestion of the contaminants by the direct eating of soil by young children, and from food grown on the garden.

Present impacts on the estuarine environment of the Waimea inlet include: the exceedance of the New Zealand Food Regulations for the eating of sediment-feeding shellfish in the estuarine mudflats next to the site, and the bio-accumulation of contaminants through the foodchain by fish and birds that eat the contaminated shellfish.

3. TENDERS FOR CLEANUP

Tenders were sought in February 2001 from three companies whose treatment technologies had been proven in earlier trials for this project.

Tenders were sought for soil clean up to: • residential standards over the whole site (requires no caveats on titles) • a combination of residential and commercial/open space standards across the site (commercial and open space clean-up criteria are the same) • commercial/open space standards for the whole site.

It is important to note that all three clean-up standards protect the off-site environment from rainfall runoff and further leaching of contaminants to groundwater. See Table 2 Section 6.2. The Council has awarded the tender to Thiess Services Pty of Australia, a highly experienced contaminated site remediation contractor, for a clean-up to the second standard listed above (“Scenario B”). The expected project cost is $6.5 million. Government funding is in place for proceeding with Stages I and II of a four stage process of remediation. The separate stages are:

Stage I: final characterisation of the site to obtain reliable data on contaminant distribution; Stage II: resource consents are obtained for the proposed works; Stage III: physical remediation of the site in accordance with the approved remedial action plan, including auditing that the site meets the target criteria; Stage IV: any ongoing monitoring and aftercare

4. CONTAMINATION LEVELS

During 1992-96, detailed reports were obtained on contamination in soils, groundwater, tidal water, estuary sediments and shellfish.

In 1998, clean-up targets for the site were derived using risk based acceptance criteria for human and environmental health (these acceptance criteria are discussed in detail below). Technical information and costs were obtained for suitable clean-up methods, and a cost- benefit analysis undertaken.

Two-thirds of the site is contaminated above residential standards, mainly up to 2.0 metres deep. Contaminated soils and chemical wastes buried on-site are the major sources of contaminated groundwater and stormwater that has, and continues to, contaminate adjacent areas of the Waimea Inlet.

Historically, wastes from plant operations were disposed of indiscriminately to a low lying area on the East side (known locally as Lake Tas), and to a reclamation of the Waimea Inlet on the western boundary, now referred to as the FCC landfill.

Further site investigations were undertaken in September-October 2001 to characterise in more detail the nature and extent on soil and groundwater contamination on the FCC site, and provide information for Thiess to undertake revised volume analysis based on Clean- Up Scenario B (refer Table 1).

5. REMEDIATION WORKS

5.1 Scale of Cleanup The cleanup will involve the excavation, treatment and reinstatement of approximately 21,000 cubic metres of organochlorine contaminated soil and marine sediments at the site.

Table 1 - Estimated Volumes of Contaminated Material requiring remediation (m3) West and FCC Landfill Marine Neighbouring Totals East FCC Sediments Properties Sites 9,950 9,300 1,000 1,200 21,450 Source: Thiess RAP (April 2002)

5.2 Mechano-Chemical Destruction (MCD) A number of alternative treatment technologies were considered to be potentially applicable from a technical and commercial standpoint, including thermal desorption (either direct or indirect) and ex-situ bioremediation. Thiess selected the MCD process which involves the dechlorination of organic compounds by the input of mechanical energy as impact forces in the presence of proprietary additives as electron and hydrogen donors.

The MCD process comprises the following elements: • Soil pretreatment and preparation, including screening and predrying. • Material feed system where additives are metered and mixed. • A reactor where contaminants are dechlorinated in the presence of electron and hydrogen donors using impact forces from tonnes of ball bearings. • Treated soil handling and reconditioning.

During the process the contaminated material is crushed to a fine particle size by the aggressive addition of mechanical energy as impact forces (and not by friction). The plant is fully enclosed and has a comprehensive dust filtering system, such that dust emissions are not predicted to be an issue for the process. Preliminary trialling of the MCD plant has been completed, and further trials are proposed later in 2002. The recently completed field trial of the commercial scale plant included associated materials handling and emission control equipment. Throughput of the commercial scale MCD plant ranges from 3 to 15 tonne/hour.

6. RISK ASSESSMENT

6.1 Potential Human Health and Environmental Effects Risks on the FCC site do not just relate to the existing contamination. The works to be undertaken for cleaning up the site bring their own risks. Obtaining resource consents during Stage II of the project will respond to local residents’ concerns about those risks. Based on our experience already in demolishing the FCC buildings in 1996, and excavating soil for treatment trials in 2000, the obvious risks to neighbours are from dust, odour and noise.

Less obvious risks are to the estuary from runoff of contaminated stormwater, the dangers of excavating and handling unidentified potentially toxic wastes, and the contractual risks of possible budget blow-out or contractor default.

Quantitative risk assessment methodologies were applied in two key areas of the Mapua site remediation. These are risk based site acceptance criteria and risk assessment of environmental affects.

6.2 Risk-Based Site Acceptance Criteria The Mapua site, once remediated, may be used for a variety of purposes including residential, recreational, and commercial. Therefore site specific risk-based soil and sediment acceptance criteria (SAC) were developed by Egis Consulting Ltd, Australia for the various landuse scenarios. SAC for key organochlorine contaminants of concern are presented in Table 2. The purpose of developing the criteria was to provide a basis for planning remediation and management works at the Site.

The methodology used by Egis in the development of the acceptance criteria was as follows:

• A screening level assessment of current contamination on and offsite (in order to support the selection of the contaminants of potential concern and to assist in understanding the relationship between contaminant concentration in various environmental media);

• Development of a conceptual model for the site and its environs, i.e. residential habitation and interactions between environmental compartments and biota, both on

and offsite, and the development of a generic food chain to assist in understanding the possible impact of sediment contamination.

• The contaminants of potential concern were determined to be DDT and dieldrin, and these contaminants formed the focus of the risk assessment.

• Exposure assessment involving a range of receptors and exposure pathways was undertaken. These included: residential land use (for typical and reasonable worst case exposure); maintenance workers (who may have to repair or install underground services); and Landfill maintenance workers (for the case where contaminated soils are disposed in Landfill).

• Human health risk-based acceptance criteria were developed for these various exposure scenarios by establishing the desired risk level and considering the exposure scenario and contaminant concentrations that correspond to the desired risk level.

• The environmental acceptance criteria were derived by considering the concentrations of contaminants found in the estuarine muds close to the Site, and the concentrations measured in soil at the Site.

• the relevant acceptance criteria are summarised in Table 2. These criteria can be applied to develop acceptance criteria for residential, commercial and open space or recreational land use options.

Table 2 - Soil/Sediment Acceptance Criteria (Source: Egis Consulting, 2001)

DDX Aldrin + Dieldrin Depth (total DDT, DDD, Land Use + 10% Lindane (m) DDE) (mg/kg) (mg/kg) Residential All 51 31 Commercial 0–0.5 51 31 Below 0.5 2002 602 Recreation/ open space 0–0.5 51 31 Below 0.5 2002 602 Marine sediment All 0.01 0.01 Notes: 1. Based on protection of the off-site environment through rainfall run off. This will also be protective of human health and groundwater. 2. Based on protection of groundwater.

Additional SAC have been adopted from Health-Based Soil Investigation Levels (HBSILs) presented in NEHF (1998). Thiess propose that other OCPs will be assessed against acceptance criteria as provided within the NSW EPA Guidelines for the NSW

Site Auditor Scheme for the relevant landuse scenario, and supplemented by the NEHF (1998) “Health Based Soil Investigation Levels.

6.3 Risk Assessment for Assessment of Environmental Effects Stage II includes the resource consent application for the full clean up. As part of development of assessment of environmental effects (AEE) documentation, human health and environmental risk assessments were undertaken to evaluate the potential for effects of exposure to contaminants (including from the MCD treatment plant) the health of neighbours and the environment during the remediation works.

This included assessing the environmental effects of the process and identifying ways of mitigating (reducing) any adverse effects. The assessment included: • Human health effects • Effects on Air quality • Noise from the equipment; and how to control it; • Dust control; • Vibration effects • Effects on the Coastal Environment • Stormwater and groundwater control; • Effects on the estuary • Visual effect • Effect on traffic.

To assess the potential for adverse human health or environmental effects due to exposure to soil contaminants during the remediation works, T&T completed risk assessments for organochlorine compounds in air, soil and water. These assessment were undertaken using risk-based acceptance criteria developed by the World Health Organisation and employing accepted international risk assessment methodologies, including ASTM (1998) and NEPC (1999).

Mitigation methods proposed for the site to reduce effects to an acceptable level include scheduling of works excavation work to minimise effects; the installation of fixed and movable visual and noise barriers, and extensive dust control measures (both fixed and mobile).

7. COMMUNICATING RISK

7.1 Introduction One of the main objectives in the early stages of the project was to quantify the extent of the contamination, then to persuade the Council and the Minister for the Environment to pay for a clean-up.

To achieve this has required a broad level of support from local residents, TDC staff and councillors, Ministry for the Environment and environmental groups.

As the Council’s $2 million contribution to the project will come from all its ratepayers, it has also required the absence of strong opposition from any TDC ratepayer group. This (hopefully) reflects the credibility and continuity of the staff and consultants running the project.

7.2 Risk Communication Challenges The human health and environmental risks posed by the organochlorine contaminants at this site have been quantified but are complex. The effects of exposure are not immediate, and the contaminants are not currently visible on the site. The ecotoxicity of DDX and dieldrin is much higher than the threshold concentrations for direct human health effect, which has led some to argue that the clean-up is being driven by ‘greenies’. This debate has at its extremes the ‘chemophiles’ unfazed by toxic chemicals and the ‘chemophobes’ worried about homeopathic levels of synthetic chemicals in the environment.

A second challenge was to harness the community energy which led to the factory closure, to ensure that the derelict site is now cleaned up. The community, particularly neighbouring property owners, is somewhat split because a clean-up will lead to development of what is currently an open area of fenced off land. We have taken particular care to defer debate until now about the future uses of the site, in case those arguments derailed agreement on the need for a clean-up itself.

A third challenge is to convince all parties that an affordable level of clean-up will still meet minimum environmental standards for the estuary and site after work is completed. One environmental group is worried that the soil acceptance criteria adopted for the site may be insufficient to protect the estuary and underlying groundwaters; they have argued for a full residential standard of clean-up, not just for the surficial soils. They also want to evaluate the full tendered details of the chosen clean-up method to convince themselves that the risks of failure are low. These details will be made available by Thiess prior to applying for resource consents for the works.

7.3 Our Risk Communication Tools The FCC Clean-up has taken over 12 years (which is 4 x 3year election cycles) to get to the point where works are about to begin. During this period we have used a variety of risk communication tools.

Mapua Task Force Community support is vital for whatever happens on the FCC site. In recognition of this, the Council invited three community representatives to join a group of councillors and staff in forming the Mapua Task Force. Their job has been to drive the project from a political and community perspective. They act as a sounding board and prompt for action, and were responsible for recommending to Council which company should be appointed to clean up the site.

The Mapua Task Force numbers 11 people and has met every 3-4 months to review progress and provide community input into the project. The Mayor and four councillors

are members of the Task Force and comprise a sub-committee of the Council when formal recommendations such as the preferred tenderer need to be made to Council. The Task Force has been a useful link between us as project managers and the community.

In retrospect the Task Force could have been given a stronger role by meeting more regularly and having a better defined link with the Mapua & Ruby Bay Ratepayers and Residents’ Association, representing residents’ views.

‘Question & Answer’ Leaflets Keeping the Mapua community informed of progress is important. The lengthy duration of the investigations and land transfer phases has led to scepticism that anything would ever be cleaned up on the site.

One highly successful tool for providing background on progress and intentions for clean-up was a ‘Question and Answer’ leaflet first produced in 1999 for a letterbox drop. The leaflet answered common questions like Where are the dead birds and people? and Why don’t the people who made the mess have to pay? It also explained what methods could be used to clean it up, and when that would be happening (although mentioning target dates has backfired as these dates slip!). The Q&A leaflet was professionally laid out and printed in two colour format by Council’s PR consultants, which enhanced the credibility of its message. The Q&A leaflet was on the Council’s website and generated some inquiries from as far away as Germany, and also locally.

As the Q&A leaflet was so successful first time around, Thiess/EDL updated it in full colour for the first phase of their public consultation.

‘Worst Contaminated Site in New Zealand’ The drive to clean up the site was certainly increased by having the FCC site referred to by the Ministry for the Environment, and in the media, as New Zealand’s worst contaminated site.

In terms of volume of contaminants and the size of the affected area, this is probably incorrect. But the persistence of the pesticide contaminants and the difficulties of cleaning up such a site in a residential and tourist area probably justify the label ‘Worst in NZ’.

The label and the associated public pressure undoubtedly helped persuade Government that this site should be the first to benefit from funding from the newly created Orphan Sites Remediation Fund administered by the Minister for the Environment.

Information Board and Fenced, Derelict Appearance Raising the profile of the site for visitors to Mapua has helped the drive for a clean-up. The FCC site is located next to the Mapua Wharf, an increasingly busy tourist and boat launching area. The Smokehouse Restaurant, which has been voted best café in Nelson, adjoins the site and diners eat outdoors five metres from the perimeter fence.

Visitors to the wharf drive past the FCC site and cannot help but notice the fencing and the overgrown appearance on both sides of Tahi Street. What they cannot see is the contamination. So in 1998 we decided to erect an information board on the fence on the Tahi St corner and one facing the inlet channel.

The information board summarises the contamination on the site, the works carried out so far, and future clean-up plans. It includes a rather provocative 1983 photo showing the chemical rubbish and other debris in the FCC landfill before it was covered over. The board also identified local contacts on the Mapua Task Force and provided safety information for collection of shellfish and for swimming. Surprisingly, the neighbours to the FCC site, including the Smokehouse, supported the placement of the noticeboard. They, like many in Mapua, saw the benefits of increased publicity and public pressure for a clean-up.

The Bad News of the Site and Good News of the Clean-up Related to political profile is the need to tell the bad news about the contamination on the site to gain support for the clean-up. However, local tourist operators have complained whenever there are headlines about the contaminated FCC site, that the bad news of the site affects tourism and especially visitor numbers wanting to stay in Mapua.

Equally, now that there is a commitment to the clean-up there are people visiting Mapua to see what the ‘infamous’ site looks like. On balance, we believe the long term need to clean up the site justified the occasional bad press it was given.

Having a Team Member Living Locally Co-author Jenny Easton lived near the factory when it was operating and has returned to live in Mapua. She contributes local knowledge about the attitudes to the site, its closure, clean up and some of the personalities involved. The site also has a landlady to keep an eye on the integrity of the fence and kick out errant skateboarders.

Attending Local Public Meetings The team, or members of it, have appeared regularly at the local Resident and Ratepayers monthly meetings, so people can put faces to names and built up trust with those responsible for this long term project

Encouraging School Projects and Public Interest There was conflict for a number of years, over whether the site should be remediated and who should pay, and annually ten or more Secondary school Geography students based their social conflict projects on the FCC site. The local interviews and surveys they carried out raised the level of debate in the district. Some primary, intermediate and tertiary students have also done projects on different aspects, and by providing all these students (and parents and friends!) with information we have stimulated the debate.

8 CONCLUSIONS

The lengthy project to clean up this “worst contaminated site in NZ” has gone through many different stages of contaminant and technical information requirements, risk assessment, funding negotiations and RMA processes. Throughout these stages it has been important to keep the local community, public and Council personnel in the knowledge feedback loop. Managing a contaminated site means dealing with the emotional component as well as the recognisable hazard, and we have used Risk Management principles and tools to do this. We are now preparing for the actual clean up phase and the risks associated with that.

REFERENCES

ASTM (1998): Standard Provisional Guide for Risk-Based Corrective Action. PS 104-98. Egis (2001): Former Pesticide Plant, Mapua New Zealand: Derivation of Risk- based acceptance criteria for Human health and the Environment Revised report Egis Consulting Ltd, 2001. NEPC (1999): National Environmental Protection Measure 7B – Exposure Scenarios and Exposure Settings. NEHF (1998): Health-Based Soil Investigation Levels. National Environmental Health Forum, 1998. NSW EPA (1998) Guidelines for the NSW Site Auditor Scheme. Thiess Services (2002): Remediation Action Plan – Fruitgrowers Chemical Company (FCC) Site, Mapua, April 2002.