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| Pesticide Monitoring in Water CatchmentsASCHEM Pesticide Water Monitoring Program
Program Structure
Pesticides Monitored
Sampling Locations
>>> Monitoring ResultsFurther Information
The ASCHEM Pesticide Water Monitoring program is designed to indicate the nature and extent of any water contamination and to inform the community and Government to allow for a more informed policy debate. The program is not designed to provide early warning events in particular locations and it cannot do that because there is often a considerable time lapse between sampling and finalisation of water analysis.
From 2005 up until August 2011, 55 sites were monitored quarterly for 19 pesticides of which a subset of four included flood sampling on the Duck, George, Esperance and Little Swanport Rivers.
To ensure the program remains as efficient and effective as possible, modifications to program methodology have now been made. Part of this included making it more risk based and targeted. Monitoring for pesticides is inherently expensive by nature and therefore needs to be geared towards those regions where there is a risk of chemical detections or where values to be protected are high.
Information from this program informs the Department’s Spray and Information Referral Unit (SIRU) as to regions of possible concern that may then be subject to further intensive monitoring. The SIRU also conducts sampling in public rivers and waterways in the course of investigations into chemical spraying incidents.
Modifications to the program commenced in September 2011. A total of 47 sites are now being monitored on a bi-monthly basis for 18 priority pesticides. A report detailing all the modifications is available in PDF format below.
This is a Portable Document Format (PDF) file and requires the use of Adobe Acrobat Reader. The Reader is easy to download and is free of charge.
The program is structured into three components. These are as follows:
The routine surface water monitoring network provides the backbone to the monitoring of pesticides in Tasmania. This network directly informs the SIRU as to regions of possible concern that may then be subject to further intensive monitoring. The network is designed to be flexible as to both its temporal and spatial monitoring; undergoing periodic review to ensure the validity of monitoring on a site specific scale.
A total of 47 sites are monitored on a bi-monthly basis for 18 priority pesticides. These sites have been chosen because they are: - sites that have recorded detections above Method Detections limits (MDL) in the last five (5) years;
- sites based on catchments and locations within catchments that present a high chemical detection risk, both in terms of crops and pesticides used and values being protected (i.e. public drinking water).
The purpose of targeted studies is to provide short term intensive surveys as a means to assess the extent and nature of chemical contamination on a sub-catchment scale. These studies are to be based on information received either through the routine monitoring program, chemical audits, and investigations that warrants a greater focus on monitoring. The inclusion of this type of monitoring affords the ASCHEM program greater flexibility in achieving its key objectives on an intensive catchment scale.
This component is scheduled to commence in 2012 with a targeted study in the Duck River catchment.
Annual sampling of groundwater sourced for drinking water purposes by water authorities will occur on an annual basis at seven (7) sites. A further four (4) sites that returned positive detections for various pesticides during a 2009 groundwater survey pilot study will also be sampled annually.
Pesticides monitored are based on some of the following characteristics: - Being representative of a group of widely used pesticides in Tasmanian agriculture and/or forestry.
- Propensity to be mobile.
- Common usage on various crops.
- Combinations of persistence and toxicology.
The list of pesticides being monitored has developed since the start of the program and will continue to do so, depending on the availability of laboratory standards and the commissioning of new laboratory instrumentation. The current list includes:
The following files detail site localities and are available for download in PDF and Google Earth format:
A complete list of results from the program for the baseline monitoring program and the flood monitoring program, is presented below in two print-friendly PDF documents:
Pesticide Monitoring Results - Routine Monitoring Program
Pesticide Monitoring Results - Flood Monitoring Program (Esperance, Little Swanport, George and Duck Rivers)
Sampling during flood monitoring usually consists of 12 samples being automatically taken by the monitoring equipment. When posting these results on the website, all positive readings are posted, however, when multiple ND (nil detection) results occur on any day, only one result is posted on the website for that day.
Pesticide Monitoring Results - Targeted Monitoring Program
Pesticide Monitoring Results - Investigations and Follow-up Testing by SIRU
Pesticide Monitoring Results - Ground Water Monitoring Project
Table Interpretation Notes
Units
Shown in the results table as micrograms of pesticide per litre of water (ug/L). A microgram is 1 millionth of a gram or 10-6 grams (also referred to as parts per billion).
Method Reporting Limit (MRL)
The lowest concentration of an analyte that can be determined with an acceptable level of uncertainty. When pesticides are identified at or above the MRL the identity of the pesticide and concentration level will be shown on the respective tables.
Method Detection Limit (MDL)
The smallest amount or concentration that can be readily distinguished from zero and be positively identified according to predetermined criteria and/or confidence levels.
When pesticides are identified at or above the MDL but below the MRL, only the identity of the pesticide but not the concentration level is confidently known.
The identity of the pesticide will appear on the respective table and be recorded as TD (trace detected). Recording of trace detections has only commenced within tables since the start of 2009. Prior to this, detections below minimum reporting limits would not have been recorded.
‘ND’
Not detected. Reported where a pesticide was not found at a level equal to or above the method detection limit (MDL). Prior to 2009 this applied to pesticides found at or below the minimum reporting limit (MRL).
Blank space
A blank space entry in a table indicates that the laboratory did not test for a particular analyte.
Guideline Value
These levels are based on the analytical limit of determination (the level at which the pesticide can be reliably detected using practicable, readily available and validated analytical methods). These values are not health-based values in terms of potential for toxic effects. In terms of drinking water, exceeding the guideline value indicates that undesirable contamination has occurred and they indicate the levels at which steps should be taken to determine the source and to stop further contamination. It does not necessarily indicate a hazard to public health.
Health Value
The level published in the Australian Drinking Water Guidelines for use by health authorities in managing the health risks associated with inadvertent exposure, such as a spill or misuse of a pesticide. The values are set at about 10% of the acceptable daily intake (ADI) for an adult of 70 kg consuming 2 litres of water per day. The values are very conservative and include a range of safety factors.
Contact: Registrar of Chemical ProductsStuart Bowman
165 Westbury Road PROSPECT TAS 7250 TAS
Phone: 03 6336 5462
Fax: 03 6336 5374
Email: Stuart.Bowman@dpipwe.tas.gov.au
Department switchboard: 1300 368 550 (local call cost within Australia)
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