1. Introduction
This study is part of a consortium approach to quantify the relative significance of key pathogen transmission routes from farm animals to water. This report, which covers the work to date in the groundwater objectives in the Consortium study, focuses on the quantification of pathogen contamination of groundwater in a border-strip irrigation farming system. Other objectives are looking at animal behaviour and the direct deposition of faecal material to water bodies and the transport of pathogens by surface runoff, and artificial drainage.
The groundwater study is being undertaken in the Waikakahi catchment, which is a largely dairying catchment in South Canterbury characterised by border strip irrigation. Fonterra Research Institute is currently funding a large study in the catchment to assess surface water quality (NIWA), and farm management practices (AgResearch). Environment Canterbury (ECAN) is providing farmer liaison and carrying out sample collection for this groundwater study. Preliminary investigations in 2002 within an Environment Canterbury funded study indicated that groundwater contamination in this type of environment might be substantial (Close 2002).
In the first year of the study (2002/03) pathogen contamination of groundwater was quantified under dairy land subject to border-strip irrigation. Information on stocking and irrigation practices was collected from the well owners, and climatic data was collated. The focus in this study is limited to Campylobacter, E. coli and total coliforms to ensure the collection of sufficient and informative data. The first year results indicated E.coli and pathogen bacteria, Campylobacter, were detected in the groundwater, with higher levels of E.coli as expected. The selection of the wells to avoid septic tank contamination and wellhead protection issues meant that the microbial contamination would be coming from dairying combined with border strip irrigation.
In this the second year of the study the impact of timing of stocking, irrigation and climatic factors on pathogen contamination of groundwater in border-strip and spray irrigation farming systems has been preliminarily assessed. Additional intensive (weekly) groundwater sampling and continued collection of stocking and irrigation data is planned for October-December 2004. Information gained from this investigation will enable effective land management guidelines to be proposed in the third year (2005) final report, particularly with respect to the timing of stocking, such that groundwater contamination is minimised.
Contact for Enquiries
MAF Information Services
Pastoral House
25 The Terrace
PO Box 2526
Wellington, NEW ZEALAND
Fax: +64 4 894 0721
Contact this person
