Historic agrichemical use and residential development

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IN THIS SECTION
	Consultation
	Read the discussion documents
	Background information

With the development of housing on Hastings District’s agricultural and horticultural land, people need to be aware of the possible presence of Historical persistent chemical residues (formerly agrichemical residues) in former agricultural, horticultural or glasshouse soils. Hastings District Council is aware of a study undertaken by the Auckland Regional Council in 2002, and has been monitoring the response of other authorities such as Hawke's Bay Regional Council and Ministry for the Environment. In 2003, Council commissioned Pattle Delamore Partners (PDP) Limited to investigate this issue and advise on the most appropriate response to address residential land development.

The report was finalised in November 2004 and adopted by Council at the 7 December 2004 meeting (read the documents below). In addition, Council gave approval for Officers to undertake consultation based on the report of Pattle Delamore Partners Ltd before reporting back with preferred options in managing historic agrichemical use in relation to residential development.

Consultation

Council asked the public to make a submission on this issue during January and February 2005 as well as invite people to a public meeting. Read the summary of submissions/responses (PDF, 20 KB).

View the presentations made by Consultant Graeme Proffitt and Environmental Planner, Nia Belcher at the public meeting:

• Redevelopment of Former orchard land for residential use, Consultant (PDF, 133 KB)
• Historic Agrichemical Use and Residential Development, Council Environmental Planners (PDF, 315 KB)

Proposed Plan Change

Read about Proposed Plan Change 28 - Historic Agrichemical Use and Residential Development.

Read the discussion documents

The following documents will provide you with a background on the issue:

View and print the documents below in PDF format. View or print PDF files using Adobe Acrobat Reader (download or update for free).

• Consultation Document – includes Options for Discussion (74 KB)
• An example of possible changes to the Hastings District Plan (29 KB)
• PDP Ltd full report; “Agrichemical Use and Residential Development” November 2004 (364 KB) - Gives a brief summary of the investigations and the purpose of the report

Background

A wide variety of agrichemicals have been used in New Zealand over the last 100 years. NZ studies have shown that only some agrichemicals components such as arsenic, lead, copper, zinc and DDT remain in the soil as contaminant residues.

In Hastings District, testing has shown the contaminant residues are mainly arsenic, lead, copper and DDT because these agrichemicals were used extensively under government registration to control agricultural pests and diseases on horticultural land, and in glasshouses, until they were withdrawn from sale about 1975. (Some tobacco growers continued to use DDT until about 1985).

These are persistent agrichemicals that tend to bind tightly to the soil, most often in the top 10cm, and may be present in the soil as contaminant residues long after they have been applied. The more soluble arsenic may leach slowly into the groundwater. These contaminant residues may also remain in the soil near old spray sheds and in farm dumps.

Generally, commercial crops grown on this soil comply with the level of residues permitted in the Food Standards Code, because these particular contaminant residues are not taken up by most plants. The concern is that this contaminated soil may pose a human health risk when the land changes from agriculture/horticulture/glasshouses to domestic housing because then people, especially children, may be exposed to the contaminant residues through eating dirt either intentionally or unintentionally after handling or playing in dirt. Dairy and organic farming may also be restricted on this soil.

Modern agrichemicals are less persistent – they generally break down in days and weeks, therefore broad scale residues are not of concern, although modern pesticides may be of concern in “hotspot” areas created by spills or where agrichemicals are stored (spray sheds).

Contact

For more information contact Environmental Planners (Policy) Nia Belcher on niab@hdc.govt.nz or Philip McKay on philipm@hdc.govt.nz or phone both Planners on 06 878 0500.