Project Appreciation and Objectives
Sixteen water companies have 78 separate undertakings from DWI for metaldehyde and are either carrying out catchment investigations or working actively with farmers to reduce metaldehyde concentrations in potable water supplies.
Following several years with low pest levels, the cool, wet weather during 2012 has provided the ideal environment for slugs and, consequently, concentrations of metaldehyde have increased significantly in rivers and reservoirs across much of England, although with some local exceptions. This suggests that voluntary measures alone may be inadequate to ensure drinking water compliance during adverse weather conditions and water companies are now questioning their strategies for tackling metaldehyde.
Companies are required to report to DWI in March 2015 and are currently developing business plans for catchment management schemes in AMP6. Yet to date there has been no formal or systematic national evaluation of the successes and limitations of different catchment-based approaches for identifying and mitigating metaldehyde risks. This study will undertake a detailed comparative evaluation of the effectiveness of current approaches, the data from 2012 provides an ideal data set, and use this to produce an evidence-based assessment of the role catchment management can play in controlling metaldehyde.
Business Benefits to Clients
- Reduced risk of non-compliance through more effective catchment management strategies.
- Cost savings through better informed investment and operational decisions.
- A stronger position for negotiating further mitigation strategies with agrochemical companies and regulators.
- Review metaldehyde sources, pathways and risk factors.
- Document the mitigation measures and delivery mechanisms currently employed to manage metaldehyde.
- Analyse patterns and recent trends in metaldehyde exceedances to assess the relative influence of weather, cropping patterns, pesticide usage, catchment characteristics and management activities.
- Critically evaluate the effectiveness of water company initiatives in case study catchments.
- Examine the strengths and weaknesses of additional mitigation measures and alternative mechanisms for controlling metaldehyde.
Project Output and Implementation
- A comprehensive technical report evaluating the effectiveness of current voluntary approaches and presenting options for optimising future mitigation strategies.
- A dissemination workshop for catchment and drinking water quality managers to review how the findings can be used to further develop catchment management plans and treatment strategies, and their implications for PR14 and beyond.
Related WRc Work
- Pesticide trend analysis for the Catchment Sensitive Farming water quality monitoring programme (Environment Agency, 2010).
- Treatment for new and emerging pesticides (UKWIR, 2010-11).