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Aquatic buffer zones in the UK - the potential to extend the existing LERAP scheme for boom sprayers - PS2011

Description
This project sets out to examine ways in which the existing Local Environmental Risk Assessment for Pesticides (LERAP) scheme could be extended to accommodate wider buffer zones that would be applicable when using conventional nozzles on a standard sprayer to apply products at the full dose. It is proposed that a user could then consult an official document to determine the extent to which the buffer zone could be reduced depending upon application factors to be defined in the project work. It has been noted that the existing LERAP scheme for boom sprayers was introduced to eliminate the risk of direct overspray of surface waters and the contamination due to drift relatively close to the end of the boom. The existing scheme is therefore now based on a 5.0 metre buffer zone measured from the end of the boom to the top of the bank giving an effective buffer zone width of 6.0 m. It is possible to reduce the width of the buffer zone in the existing scheme depending upon the dose applied, the characteristics of the water course and the drift reducing abilities of the application system. A LERAP Low Drift Star rating system has been devised that relates the drift from a given application system to that of a reference system with the option of reducing the width of the buffer zone depending upon the star rating of the application system. However, there may be situations when a 5.0 m wide buffer zone with a conventional application system applying a pesticide at full dose will lead to concentrations of pesticide in surface waters that will exceed maximum allowable levels. The project will seek to address this situation by exploring the use of larger buffer zones and associated specifications for the situations when they can be reduced. Buffer zone widths and the strategies that will allow the widths to be reduced will be identified following a review of the available literature and calculations relating to different buffer zone features including width and the presence of vegetation in the zone. Particular attention will be paid to parameters that have been included in the existing scheme (applied dose, characteristics of the water body and drift reducing characteristics of the application system) but will not be confined to these. Emphasis will also be placed on identifying situations where reductions in drift can be realistically achieved in typical commercial circumstances allowing the increased widths of buffer zones to be reduced when and where appropriate. The report of the work will set out proposals and options for implementing an extended buffer zone scheme.
The potential for using wider buffer zones as part of the product approval process with the use of drift reducing nozzles being specified as part of the statutory conditions of use and with a smaller width of buffer zone will also be investigated. This will use data from the main literature review but will only consider reducing buffer zone widths based on the drift reducing characteristics of the application system.

Some European states (e.g. Germany and Belgium) define a category of drift reducing application systems able to deliver greater than 90% drift reductions when compared with the reference system. The largest drift reduction in the existing LERAP scheme is 75% corresponding to a three star rating. The feasibilty of defining a 90% drift reduction category will be investigated together with the implications that such a category would have for implementing an extended classification scheme.
Objective
1. To examine the potential for extending the existing Local Environmental Risk Assessment for Pesticides (LERAP) scheme to accommodate wider buffer zones and an increased range of application situations and, if appropriate, propose ways in which this could be achieved.

2. To examine and report the potential for using wider buffer zone specifications as part of the product approval process with the use of drift reducing nozzles being specified as part of the statutory conditions of use and with a smaller width of buffer zone also being specified.

3. To evaluate the option of using a new category for drift reducing nozzles that could, for example, achieve drift reductions of greater than 90% when compared with the reference standard system.
Project Documents
• Final Report : Aquatic buffer zones in the UK - the potential to extend the existing LERAP scheme for boom sprayers   (307k)
Time-Scale and Cost
From: 2006

To: 2007

Cost: £9,965
Contractor / Funded Organisations
Silsoe Spray Application Unit
Keywords
Agricultural Land              
Application              
Biodiversity              
Crops              
Decision Making              
Environmental Impact              
Environmental Protection              
Farming              
Land              
Pesticide use              
Water              
Water Quality and Use              
Fields of Study
Pesticide Safety