IMPLEMENTATION OF NEW ZEALAND S CONTAMINATED LAND MANAGEMENT GUIDELINES BY ENVIRONMENT CANTERBURY

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1 IMPLEMENTATION OF NEW ZEALAND S CONTAMINATED LAND MANAGEMENT GUIDELINES BY ENVIRONMENT CANTERBURY Davies H.M 1. Coakley J 2. Proffitt G.T. 3 and Lucy R. 3 1 Environment Canterbury, PO Box 345, Christchurch. Telephone: , helen.davies@ecan.govt.nz 2 Ministry for the Environment, PO Box 10362, Wellington. 3 Pattle Delamore Partners Limited, PO Box 6136, Wellington. INTRODUCTION New Zealand has a range of activities that have the potential to contaminate land. As well as industrial activities associated with urban areas, some rural activities are important contributors to site contamination. These include timber treatment, sheep dipping, and intensive pest control associated with orcharding and pest destruction depots. Environment Canterbury is a regional authority with statutory responsibilities for managing natural resources in the Canterbury region of New Zealand. These include the prevention or mitigation of any adverse effects of the storage, use, disposal, or transportation of hazardous substances (s30(1)(v) Resource Management Act (RMA) 1991). Management of adverse effects on natural resources caused by contaminated land is covered within this, although there are no specific provisions in the RMA relating to, and no other legislation dealing with, contaminated land. This means there is a lack of clear policy and legislation on matters specific to management of contaminated land. Gaps in the current policy and regulatory framework include retrospective liability for historic activities causing contamination, management of sites where the polluting party no longer exists or is unable to pay, and legal responsibility for contamination that occurred prior to enactment of the RMA in Environment Canterbury has sought to maximise its ability to manage effects from contaminated land in all situations within the limitations of the legislation. The Ministry for the Environment (MfE), in association with regional councils and unitary authorities in New Zealand, has recently been developing a series of guidelines on management of contaminated land. These attempt to encourage greater national consistency, to promote awareness of the impact of contaminated sites on the environment and to provide necessary guidance. The guidelines have been adopted by Environment Canterbury in its proposed Natural Resources Regional Plan. This Plan, and associated Contaminated Land Management Strategy (ECan 2004a) define Environment Canterbury s activities associated with management of contaminated land in the region. This paper details implementation of the MfE contaminated site guidelines by Environment Canterbury. CONTAMINATED LAND MANAGEMENT GUIDELINES The Ministry for the Environment is working in partnership with regional councils and unitary authorities to develop a national approach to the management of contaminated land in 1

2 New Zealand. This work should provide consistency in contaminated site assessment and management throughout the country. A series of Contaminated Land Management Guidelines (CLMGs) is being produced by the Ministry for the Environment in collaboration with contaminated land practitioners from regional councils and unitary authorities. Industry representatives and environmental consultancies are also being consulted and have helped in the preparation of the guidelines. So far four guidelines have been published: CLMG 1 Reporting on contaminated sites in New Zealand (MfE 2003a) This guideline details the type and amount of information required in a contaminated site report. Its aim is to ensure consistency in the reporting on contaminated sites. It includes checklists for reporting requirements for contaminated sites and for the removal of petroleum underground storage tanks. CLMG 2 Hierarchy and Application in New Zealand of Environmental Guideline Values (MfE 2003b) This guideline has been developed to ensure the consistent selection and application of environmental guideline values. An Environmental Guideline Value (EGV) database (available on CD ROM) accompanies this guideline. It is designed to assist environmental consultants and landowners undertaking contaminated site investigations, and council staff involved in reviewing contaminated site assessment reports. CLMG 3 Risk screening system (MfE 2004b) This guideline describes the Risk Screening System (RSS). The system aims to provide a nationally consistent means of ranking sites that are, or are suspected of being, contaminated. The purpose of ranking a site is usually so that it may be prioritised for further investigation. CLMG 5 Site Investigation and Analysis of Soils (MfE 2004d) This guideline provides best practice for the sampling and analysis of soils on sites where hazardous substances are present or suspected in soils, and guidance on the principles governing the interpretation of the data obtained. A further guideline has been prepared and is currently open to public consultation: CLMG 4 Classification and information management protocols (MfE 2004c) This guideline suggests a nationally consistent way of classifying, managing and releasing contaminated site information held on council registers or databases. Local government is encouraged to adopt the systems and classifications so that a nationally consistent system will enable all practitioners involved in contaminated land to talk the same language. The Ministry has also published industry guidelines for the assessment and management of contaminated gasworks sites (MfE 1997b), petroleum industry sites (MfE 1999), and sites contaminated with timber treatment chemicals (MfE/MoH 1997). The Ministry is currently working with local government, the agricultural industry and other stakeholders to develop guidelines for the management of disused sheep-dip sites and horticultural areas. 2

3 NATURAL RESOURCES REGIONAL PLAN Environment Canterbury s Proposed Canterbury Natural Resources Regional Plan (NRRP) was publicly notified in July It sets out how Environment Canterbury proposes to manage Canterbury s land, water and air resources. The plan identifies the resource management issues to be addressed, the environmental outcomes to be achieved, and the policies and methods for making it happen. The Plan is made up of eight chapters with contaminated land management covered in the fourth chapter (Water Quality). This part of the Plan was written at a time when the Ministry for the Environment was finalising several of its contaminated land guidelines. The contaminated land policy and methods in the proposed Plan are consistent with Ministry guidance at the time, and endeavour to assist with the contaminated land management as indicated in Figure 1. Environment Canterbury already had existing active work programmes in many of activities indicated in Figure 1. However, the Ministry guidance documents formalise and build upon these programmes and provide clear goals and national consistency. Figure 1. Contaminated land management at Environment Canterbury. Desk-top identification of sites in Canterbury with activities listed on the HAIL 1 Registration of these sites on the Listed Land Use Register Prioritisation of these sites Field investigations of high risk sites Remediation or management of sites, as required Information Management Advocacy Regional investigations Liaison with TAs and other stakeholders Regulatory methods (rules, consent conditions, enforcement) 1 HAIL: The Ministry for the Environment s Hazardous Activities and Industries List (see below) Timeframes associated with the work themes in Figure 1 were based on those specified in MfE s (2002) New Zealand Waste Strategy. Additionally, investigation and excavation on contaminated land will now require certain conditions to be met via rules in the Plan. These rules have been introduced in an effort to ensure that site investigations, management and reporting are all conducted in accordance with MfE contaminated land management guidelines, and that these reports are forwarded to Environment Canterbury. 3

4 COLLECTION OF INFORMATION Effective management of adverse effects on the environment from contaminated sites requires that their locations be identified. Once the locations and nature of activities is known, policy and legislative provisions can be used where possible, to manage any contamination that may be present. The Ministry for the Environment has produced a Hazardous Activities and Industries List (HAIL) (MfE 2004a) to assist in identification of all sites that have the potential to be contaminated because of past or present land use. Use of the HAIL is anticipated to identify most situations in New Zealand where hazardous substances could cause, and in many cases have caused, land contamination. Environment Canterbury has established a work programme to identify all sites in the region indicated as having a past or present land use listed on HAIL within the next 10 years. The programme will start in the 2005/06 financial year and will be undertaken on a district by district basis. To assist with the above approach, there is also an on-going programme to conduct regional investigations of certain perceived high risk activities in Canterbury to gain further information on the locations of these sites, and the contamination issues associated with them. Land uses for which regional investigations have already been conducted are timber treatment sites, clay target clubs and sheep dips. Future guidance is required for other land uses, for example horticultural land converted to residential use and for management issues such as background concentrations of contaminants in soils. This guidance will be provided centrally through MfE s guidelines, or by Environment Canterbury through regional investigations. MANAGEMENT OF INFORMATION When information has been obtained about sites suggesting they have an activity listed on the HAIL, this information needs to be verified through site visits, inspection of aerial (and other) photographs, interviews, and investigation reports. Environment Canterbury has been collecting and verifying information about sites for over five years. Holding large amounts of sensitive information raises a number of information management issues, not least of which is the legal liability that might arise through improper or inadvertent release, particularly if it has not been verified as correct. To assist with these challenges Environment Canterbury developed the Contaminated Sites Information Management Strategy (ECan 1999) and a database (the Listed Land Use Register). The Strategy will soon be updated using site classification and information management protocols developed by MfE (MfE 2004c consultation draft). The MfE guideline covers: Information management protocols, Site owner notification process, Site classification system, Information release protocols, 4

5 Database security. RISK SCREENING OF SITES FOR PRIORITISATION A Risk Screening System (RSS), published as CLMG 3, has been developed as a simple tool to determine a site s risk as a desktop exercise, with the intent being to use the resultant risk rankings across many sites to prioritise the site for further investigation. The RSS uses readily available information to define a relatively small number of input parameters, with the aim being that the same ranking would be obtained for two sites of the same type and similar setting regardless of who carried out the assessment. The RSS is a simplified version of an earlier Rapid Hazard Assessment System (MfE, 1993), which proved to be unnecessarily complex for rapid screening and could produce inconsistent results, depending on user interpretation. The simplified system deliberately results in a coarse ranking, only identifying a site as having a low, medium or high risk, rather than a numerical rating. It recognises the reality that missing information was often replaced with default, or even guessed, parameter values to avoid having to embark on an information gathering exercise. Such information gathering defeated the rapid assessment intent and diverted scarce resources. The RSS is based on evaluating the risk equation made up of a Hazard (the contaminant), the Exposure Pathway (via direct contact, including vapours, surface water or groundwater) and the Receptor (people or an ecosystem). The RSS is multiplicative, which reflects that the presence of all three components of the risk equation will indicate some level of risk, while the absence, or near absence, of any of the components means no or minimal risk. The Hazard and Exposure Pathway components of the risk equation are defined in the RSS by a small number of parameters that are assigned values to reflect the degree to which the hazard exists and the exposure pathway is complete, and the sensitivity of the Receptor, hence: Risk = Hazard x Exposure Pathway x Receptor Where: Hazard = Toxicity x Quantity x Mobility Exposure Pathway = Containment x Pathway Barrier 1 x Pathway Barrier 2 Receptor = a single value as a measure of sensitivity of site use or receiving water use, or whether there is a sensitive ecosystem This is similar to the original MfE system except a much smaller number of contaminant, site and receptor characteristics are evaluated, with only those characteristics considered to be the greatest contributors to the risk being included. Three exposure pathways are independently analysed; surface water exposure, groundwater exposure and direct contact with soil, with a site s risk-ranking being the pathway giving the worst case (highest score). Exposure pathway barriers and the receptor sensitivity are different for each of the three pathways, whereas toxicity, mobility and quantity are, with some important provisos, the same for each pathway. The user identifies the different substances that could exist in the environment at the time of the evaluation, either from 5

6 historic activities or the current site use and values are assigned for these. To enable rapid analyses the RSS is performed on the RSS Template, either by hand or in a spreadsheet. The RSS is not intended to provide fine distinctions between sites and, in fact, sites of a similar type in a similar setting should return the same score. It is therefore a mistake when using the system to spend too much time trying to refine a particular parameter because the extra effort is not rewarded in a more accurate score the system is intentionally a coarse tool. This is a direct result of the multiplicative nature of the system, with no one parameter able to influence the result greatly. Environment Canterbury, in implementing its contaminated site management strategy, recognised further streamlining of the RSS can be achieved by using common input parameter values for similar types of sites. To take an obvious example, service stations have a similar configuration and have the same hazardous substances wherever they might be located, allowing all but the quite specifically site-determined pathway barrier or site sensitivity parameters to be pre-set for all such sites. Any variation in risk ranking from one service station to another is then totally due to their relationship to the wider environment, rather than the fixed site parameters. Thus, for all service stations, assumptions can be made about the toxicity, mobility and quantity of the various petroleum hydrocarbons normally present. While in reality there will be variations from site to site, the coarse nature of the RSS allows such variations to be ignored, while still remaining a useful prioritising tool. Setting some of the pathway barrier parameters as constants for particular types of sites is more difficult than for the substance parameters, because these parameters are inevitably sitespecific to a greater or lesser extent. But again, for many site types there is sufficient commonality in site configuration, site practices and site settings that, within the limits of the coarse nature of the RSS, it is possible to pre-set some of the values. The danger is that an unthinking paint-by-numbers approach might be taken when evaluating a site. To guard against this the assessor needs to be an experienced practitioner with sufficient local knowledge that they can spot when a particular site or site setting does not suit the generic approach. Environment Canterbury engaged Pattle Delamore Partners to work through the approximately 50 site categories on the HAIL, taking into account each of the likely contaminant and determining generic values for as many of the RSS parameters as possible. In total, 1350 generic parameter values were determined, and presented in tabulated form. This allows an assessor to quickly look up and insert the generic values for a particular site, greatly speeding up the process of evaluation. An internal procedure document was written to provide guidance on the use of the generic parameters and to provide additional guidance on the other parameters to that available in the RSS document (MfE, 2004b). INVESTIGATION AND MANAGEMENT OF HIGH RISK SITES Once high-risk sites have been identified, further investigation is required. In some situations, information held about a site may be very limited, and further investigation by preliminary inspection may reveal that all risks are managed. In other situations, development of land, or changes in activities on land will require site assessments to be conducted as part of statutory 6

7 planning and consenting requirements (e.g. provisions in the Natural Resources Regional Plan or in territorial authority plans). When Environment Canterbury receives site investigation reports from the site owner or territorial authorities, they are assessed to determine whether they accurately describe the risk presented to the environment and human health by any contaminants identified on the site, and to determine a category to be assigned to them in the Listed Land Use Register. Standard templates are used for this purpose, and these draw upon the guidance given in the MfE contaminated land management guideline series, as well as their industry based guidelines (MfE/MoH 1997, MfE 1997 and MfE 1999). However, many of the sites identified as high risk by the Risk Screening System will have no impending development work, or other activity (such as property sale) that would encourage investigative or remedial works to take place through regulatory or other mechanisms. Problems arise when the polluting party no longer exists, or the current owner is not aware of the contamination. Alternatively, the current owner may be aware of the problem, but unable or unwilling to finance any work in the absence of regulatory requirements. Furthermore, the cost of remedial work may outweigh any increase in the value of the land. This is a common problem where the pressure for land is not great and such sites may be left in a contaminated state indefinitely. If the risk is determined as unacceptable, Environment Canterbury will consider an application to MfE s Contaminated Sites Remediation Fund. CONTAMINATED SITES REMEDIATION FUND The government has agreed for funding to be made available from the Contaminated Sites Remediation Fund (CSRF) to assist regional councils to encourage investigation and remediation of contaminated sites that pose a known or potential risk to human health and the environment within their regions (MfE 2004e). Contaminated sites that are posing or likely to pose a high risk to human health; are located in environmentally or culturally sensitive areas; or where the landowners do not have sufficient financial resources to undertake the work required themselves but want to do something about the problem are prime candidates for the CSRF. This Fund is consistent with the Government's principles and approaches for sustainable development for New Zealand (DPMC 2003). The Government has approved an annual appropriation of $2 million to the CSRF. The Government has agreed that a three year trial from July 2003 to June 2006 be conducted in which a proportion of the CSRF be employed to assist local authorities to remediate historically contaminated sites for which they have accepted some responsibility. Up to $1 million per year will be made available to regional councils for investigation and remediation of contaminated land on a contestable basis. The remainder of the funds will be made available to continue to assist with the clean up of two of New Zealand s worst contaminated sites; the ex-fruitgrowers Chemical Company site at Mapua and the abandoned Tui mine on the western side of Mount Te Aroha. The Mapua and Tui Mine sites were selected due to the very high risk posed by these sites. In both cases, remediation is urgent because contaminants from the Mapua site are leaching into the nearby 7

8 estuary, and contaminants from the Tui mine site are leaching into local streams and present a risk to the Waihou River. The CSRF is underpinned by the following principles: 1. A partnership between the Government, local government and landowners (note that private landowners are not eligible for assistance at this time. Regional councils may choose to work in partnership with a district or city council, an individual site owner or previous polluter of a specific site of concern) to investigate and remediate a contaminated site. 2. Where remediation of a site results in significant betterment, and this betterment is realised through the sale of the property, the increase in the value of the site attributable to the remediation is to be shared between the funding parties in the same ratio as their respective funding shares. 3. No liability for any site is presumed by the Government through the provision, or application, of the CSRF. Since introduction of the CSRF in July 2003, Environment Canterbury has received funding for three contaminated sites projects: 1. Remedial planning for an area of harbour sediment contaminated by historic boat maintenance activities at a dry dock; 2. Preliminary investigation of soil at a major disused agrichemical contractor site; 3. Preliminary investigation of soil at approximately 84 residential properties located on a closed landfill in the Christchurch urban area. ADVOCACY As well as conducting the activities to identify, risk screen and investigate sites, as outlined above, Environment Canterbury will continue to advocate appropriate management of contaminated sites through a variety of methods: 1. Liaison with the Ministry for the Environment to formalise the roles and responsibilities of the various agencies and landowners and occupiers for managing contaminated sites, and to develop a national policy on the management of contaminated land; 2. The use of national guidelines published or endorsed by the Ministry for the Environment, when assessing and reporting on contaminated land; 3. Education of site owners, property consultants, financial institutions, territorial authorities, public health and other agencies to: be aware of contaminated land issues; adopt appropriate management methods for contaminated land; and provide information to Environment Canterbury about contaminated and potentially contaminated land. 4. Encourage owners of, or parties with liability for, land, where any of the land uses identified in the HAIL are likely to have occurred, to undertake an assessment of contamination and carry out mitigation measures necessary to address risks prior to the subdivision or redevelopment of the land. 8

9 CONCLUSIONS The Ministry for the Environment has recently embarked upon a programme to produce a suite of contaminated land management guidelines to assist contaminated land management practitioners in New Zealand. Environment Canterbury has used these to guide the content of contaminated land rules and policy in its Natural Resources Regional Plan, and associated Contaminated Land Management Strategy. The number of sites in Canterbury with the potential to be contaminated is currently unknown. Environment Canterbury has set itself a 10 year work programme to identify these sites using the MfE s Hazardous Activities and Industries List (MfE 2004a) as a guide to the relevant past or present land uses. Information will be managed in accordance with MfE protocols (MfE 2004c). Regional investigations on specific land uses will be conducted to complement this process and provide technical guidance. The Risk Screening System (MfE 2004b) will be used to prioritise sites requiring further investigation. Conditions in rules in the Natural Resources Regional Plan and in District Council Plans will require investigations in some situations, and Environment Canterbury will apply to the MfE s Contaminated Sites Remediation Fund to facilitate investigative and remedial work at a small number of other sites that pose a high risk to human health or the environment. Environment Canterbury expects all investigations to be conducted, and results interpreted and reported in accordance with the MfE guidelines. Environment Canterbury recognises deficiencies in current legislation and will advocate that the Ministry for the Environment formalise the roles and responsibilities of the various agencies and landowners and occupiers for managing contaminated sites, and to develop a national policy on the management of contaminated land. ACKNOWLEDGEMENTS Guy Knoyle is thanked for his editorial review of this manuscript. Raymond Ford and Barry Loe are acknowledged for managing the development of the Natural Resources Regional Plan, Chapter Four. Dave Clancey is acknowledged for his input into Environment Canterbury s draft contaminated land management strategy. Representatives from regional councils and unitary authorities are acknowledged for their input into the Ministry for the Environment s contaminated land management guidelines. REFERENCES Department of Prime Minister and Cabinet (DPMC) Sustainable Development for New Zealand Programme of Action. Department of Prime Minister and Cabinet, Wellington, New Zealand. Environment Canterbury (2004a). Draft Contaminated Land Management Strategy. Environment Canterbury, Christchurch, New Zealand. 9

10 Environment Canterbury (2004b). Natural Resources Regional Plan, Chapter 4, Water Quality. Policy WQL11 Management of Contaminated Land. Environment Canterbury, Christchurch, New Zealand. Ministry for the Environment (1993). National Rapid Hazard Assessment System for Potentially Contaminated Sites (Draft). Ministry for the Environment, Wellington, New Zealand. Ministry for the Environment/Ministry of Health (1997). Health and Environmental Guidelines for Selected Timber Treatment Chemicals. Ministry for the Environment, Wellington, New Zealand. Ministry for the Environment (1997). Guidelines for Assessing and Managing Contaminated Gasworks Sites in New Zealand. Ministry for the Environment, Wellington, New Zealand. Ministry for the Environment (1999). Guidelines for Assessing and Managing Petroleum Hydrocarbon Contaminated Sites in New Zealand. Ministry for the Environment, Wellington, New Zealand. Ministry for the Environment (2002). The New Zealand Waste Strategy. Towards Zero Waste and a Sustainable New Zealand. Ministry for the Environment, Wellington, New Zealand. Ministry for the Environment (2003a). Contaminated Land Management Guidelines No. 1: Reporting on contaminated sites in New Zealand. Ministry for the Environment, Wellington, New Zealand. Ministry for the Environment (2003b). Contaminated Land Management Guidelines No. 2: Hierarchy and Application in New Zealand of Environmental Guideline Values. Ministry for the Environment, Wellington, New Zealand. Ministry for the Environment (2004a). Contaminated Land Management Guidelines Schedule A: Hazardous Activities and Industries List (HAIL). Ministry for the Environment, Wellington, New Zealand. Ministry for the Environment (2004b). Contaminated Land Management Guidelines No. 3: Risk Screening System. Ministry for the Environment, Wellington, New Zealand. Ministry for the Environment (2004c). Contaminated Land Management Guidelines No. 4: Classification and Information Management Protocols. Consultation draft. Ministry for the Environment, Wellington, New Zealand. Ministry for the Environment (2004d). Contaminated Land Management Guidelines No. 5: Site Investigation and Analysis of Soils. Ministry for the Environment, Wellington, New Zealand. Ministry for the Environment (2004e). The Contaminated Sites Remediation Fund: Guide to Regional Council Applicants. Ministry for the Environment, Wellington, New Zealand. 10