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Managing Persistent Organic Pollutants and Intractable Agrichemicals in the Waikato Region

Report: TR 2007/43
Author: William Gauntlett, Michelle Begbie, Bruce Willoughby



As technology and knowledge about pests and diseases improves, more and more agrichemicals become obsolete and excess to requirement in New Zealand. Unwanted agrichemicals pose risks to the environment and human health when stored on rural properties, but safe disposal of these chemicals is costly and difficult. New Zealand has an obligation under the Stockholm Convention to ensure that persistent organic pollutants (many of these having been used as agrichemicals) are correctly managed and their release minimised. As a result, the Ministry for the Environment has worked with Regional and Unitary authorities since 1992 to provide free collection and disposal services to landowners and managers.

This report provides an overview of unwanted agrichemical collections held in the Waikato region since 1992, and also explores the issue of agrichemical collections nation-wide. While collections in the Waikato region have been successful, results show that significant volumes are recovered in areas which have already been subject to a collection, and that typical response rates are in the order of 45-60%, indicating that >40% of individuals do not have their unwanted agrichemicals quantified or qualified during each collection. These factors reduce the accuracy of volume estimations for unwanted agrichemicals remaining in each region, and also restrict our ability to produce better estimates. The Waikato experience has also shown that the dominant land use of an area affects the proportion of persistent organic pollutants (POPs) to non-POPs, that telephone contact with individuals increases response rates four-fold and that the population of volumes recovered are highly skewed, indicating small incidences of very large volumes recovered. These outliers can severely impact the cost of collection, as they are difficult to predict. A survey undertaken in the Waikato area indicates that many individuals are unaware of their legal obligations to store and dispose of POPs, and this shows a need for more education and promotion. The cost of collections undertaken in the Waikato has been on the rise, with a growing proportion of chemicals classed as 'intractable' leading to higher disposal costs offshore.

The Waikato experience concludes that passive collections using drop off points are less effective than on-farm collections which, while more expensive, provide invaluable assurance as to safe handling and transport of hazardous substances. Because passive collections using drop-off points are less effective, this report concludes that on-farm collections are required in order to significantly reduce the volume of unwanted agrichemicals stored in rural areas. However, drop-off points are still valuable for those individuals who cannot wait to dispose of their unwanted agrichemicals. In the past, the drop-off points have typically been transfer stations. There is currently a shortfall between the level of resources required to safely handle unwanted agrichemicals, and the level commonly experienced at transfer stations. Rising costs are beginning to make the continuation of 'free' agrichemical collections look uncertain.

The Ministry for the Environment currently propose to end their share of funding for the unwanted agrichemical collections at 30th June 2009. A national product stewardship scheme is proposed, in order to provide a clear life cycle for agrichemicals which are manufactured in the future. There are a number of gaps between this model and the current mechanism of collecting unwanted agrichemicals. While identifying these gaps, this report identifies the key challenges to bridging them, and provides recommendations that may begin to address these issues. This report recommends that the way forward is to develop a strategy that will provide a smooth transition to a product stewardship scheme while still providing a mechanism for the collection of old unwanted agrichemicals which have become a hazardous legacy.


Managing Persistent Organic Pollutants and Intractable Agrichemicals in the Waikato Region
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Table of contents

  Acknowledgements i
  Executive summary v
  Project background v
  History of collections v
  Predicting and defining volumes to be collected vi
  Conclusions vi
  The wayforward viii
1 Introduction 1
1.1 Project background 1
1.2 Purpose 2
1.3 Legislative context 3
1.4 Scale of the problem 4
1.5 Report structure 5
2 Active agrichemical collections in the Waikato region 5
2.1 Collections undertaken 6
2.1.1 Roto-O-Rangi trial (1992) 8
2.1.2 Waikato regional collection (1992-1994) 8
2.1.3 Tokoroa, Naike/Te Akau and Pokeno trials (2004-2005) 8
2.1.4 Waitomo and Otorohanga collections (2006-2007) 9
2.2 Discussion 9
2.3 Participation and response 10
2.3.1 Type of promotion 11
2.3.2 Type of collection 13
2.4 Distribution of agrichemical 14
2.4.1 Uneven distribution of risk 14
2.4.2 Inappropriate use of the mean 15
3 Passive agrichemical collections in the Waikato region 16
3.1 Standards and quality 17
3.2 Promotion 18
3.3 Quantities collected 18
4 Disposal designation classification 19
5 Predicting remaining volumes of unwanted agrichemicals 21
5.1 Importance of robust estimates 21
5.2 Ministry for the Environment estimates 21
5.3 ENVIRONMENT WAIKATO estimates 22
5.4 Limitations of the estimates 23
5.5 Questionnaire to assist estimates 24
6 Proposed strategy 25
6.1 Introduction 25
6.2 Desired outcomes of the proposed strategy 25
6.3 Overview of the proposed strategy 26
6.4 Next steps for the Waikato region 27
6.5 Product stewardship 28
6.6 Key issues and actions 29
6.6.1 Review estimates 29
6.6.2 Feasibility of proposed collection method 30
6.6.3 Review designation-list 30
6.6.4 Secure funding 30
6.6.5 Review collection contract 30
6.6.6 Setup agrichemical collections 31
6.6.7 Provide agrichemical information 31
6.6.8 Undertake agrichemical collections 32
6.6.9 Product stewardship programme 32
6.6.10 Audit system 33
6.6.11 National extension 33
6.6.12 Targets and monitoring 33
7 Conclusion 34
  Glossary 36
  References 39
Appendix 1 Methodology for estimating volumes of unwanted agrichemicals 41
  Preparing farmer/grower numbers for projections 41
Method 1 Estimation by simple linear model 42
Method 2 Preparation (accounting for unknown land use) 43
  Apportioning agrichemicals from properties with unknown land use 43
Method 2 Estimation by extrapolation 44
Appendix 2 Example questionnaire 49
Appendix 3 Summary report post-questionnaire trial 52