Alternatives Needed for Agrichemical Container Disposal
New Zealand uses around 1000 tonnes of plastic agrichemical containers each year ? all of which require disposal. How can this be done in an environmentally acceptable manner? Dan Bloomer discusses the issue.
Unlike many countries, New Zealand does not have a system in place to gather detailed statistics on pesticide use, making a full assessment of agrichemical container use virtually impossible. However, estimated volumes are presented in MAF Policy Technical Paper 99/11. It shows over 3,600 tonnes of active ingredients were applied in 1998, with almost two-thirds being herbicides.
High density polyethylene (HDPE) is commonly used as a material for agrichemical container manufacture. Agrichemical manufacturers estimate approximately 1,000 tonnes of HDPE agrichemical containers were produced nationally in 1998. A sample of 20-litre agrichemical containers weighed a little over 1.36kg each, so the equivalent of some 735,000 20-litre agrichemical containers require disposal each year. Interestingly, a sample of 10-litre containers weighed 340g each, quarter of the material for half the volume of chemical, so the smaller package is twice as material efficient!
A Canterbury estimate suggests 200 tonnes of used HDPE agrichemical containers were generated in central Canterbury in the 1998/99 year, which equates to about 150,000 20-litre container equivalents. Based on tonnes of pesticides, a similar number could be generated in Hawkes Bay, equivalent to 31 containers for every rural property.
The amount of HDPE containers requiring disposal may now be significantly less. In pipfruit production there has been a large shift toward cardboard containers and water soluble bags, especially for horticultural chemicals (insecticides and fungicides). In cropping and pastoral farming some evidence suggests a move to large returnable containers for herbicides. In forestry, a very large user of herbicides, there has been increased use of dry formulations in paper packaging. In January 2001, industry sources estimated that Hawkes Bay generated 120,000 20-litre containers, equivalent to 25 containers per year per rural property, and over 160 tonnes of plastic.
A position paper by the Methven Farmers Arable Landcare Group outlines a range of integrated management options for used containers including both on and off-farm disposal. Discussing disposal options from a farmer?s perspective they note:
- many district councils will not accept containers at land fills;
- many councils require consents for on-farm landfills; and
- a number of regional councils have a ban on burning plastic containers.
The above paper discusses the reduce, re-use, recycle, recover, and dispose hierarchy, and suggests that re-use could potentially deal with about 10 percent of the problem and recycling 40 percent, if a suitable system, such as that used by the US Agricultural Container Research Council (www.acrecycle.org), were established. Energy recovery through incineration is possible, although high temperatures are required to meet emission standards and the cost of returning containers to a suitable facility may be prohibitive.
British studies show that an on-farm incinerator burning triple rinsed five-litre HDPE containers in cardboard boxes can produce smoke which is the equivalent of burning wood. A trial using the incinerator design in New Zealand used 20-litre HDPE containers but found the temperatures needed for clean incineration were not achieved sufficiently. It is understood that some regional councils may be allowing this method of disposal but others have rejected the proposition.
Various studies have shown that proper triple rinsing removes all detectable (at 1 ppb) residues. Recycling companies in Hawkes Bay and Auckland suggest there is a ready market for recycled product that has been properly triple rinsed. However, the cost of collecting the materials makes this a commercially non-viable proposition unless some form of subsidy is available. It is believed that if containers were returned to central depots, a truck-based grinder could economically prepare material for the recycling industry. Apart from collection costs, the main issue is guaranteeing the containers are correctly triple rinsed, so a formal checking system would be necessary.
The most desirable situation is reducing the number of containers, through either reduced agrichemical volumes, increased use of re-usable containers, or adoption of alternatives. It would appear from current agricultural practices and technologies that HDPE containers will remain a component of primary production for some time. Therefore a full economic analysis is recommended to establish the costs and benefits of recycling options. The role of deposit payments on containers should be part of this analysis.
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Dan Bloomer Sustainable Land Management Group Hawkes Bay Regional Council Napier, New Zealand Dan joined Hawkes Bay Regional Council in 1998 after a polytechnic career that included several years as chair of the Primary Industries Polytechnic Tutors? Association, and chair of the New Zealand Qualifications Authority National Advisory Group on Environment, Conservation and Resource Management. Prior to that he was a kiwifruit orchardist and worked as a technical representative for an irrigation company. Dan has been instrumental in the establishment of LandWISE, a voluntary land management group focused on sustainable cropping technologies. He is an executive member of the New Zealand No-Tillage Association, and represents regional councils on the New Zealand Agrichemical Education Trust. He has just completed a thesis on the adoption of sustainable cropping practices for an MSc (Tech) in innovation management. |
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Amber Duncalfe
Editor - RM Update
Ministry of Agriculture and Forestry
PO Box 2526
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NEW ZEALAND
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