Groundwater Vulnerability Assessment of Plant Protection Products: A Review

Plant protection products (PPPs) pose a serious dilemma; although their application contributes to the fight against poverty and diseases, at the same time these agrochemicals represent a significant public health threat. As part of Ireland's commitment to the Water Framework Directive (WFD), the country's groundwater sources and resources have to be properly monitored and specific standards in groundwater quality need to be met. Vulnerability assessment is a methodology that evaluates the likelihood of an adverse event occurring and this information can be useful for pollution prevention and decision-making purposes. The objective of this article is to review and compare the most important vulnerability assessment methods and tools that have been used in catchment/regional scale studies. While the approach used is largely dependent on available data, user requirements, and local conditions, the evaluation showed that the COP and PI index-based methods and the MACRO and PRZM process-based methods represent the most advanced tools currently available for large-scale applications. Also discussed is the importance of statistical methods for uncertainty analysis and their usefulness in reducing the data requirements of the index and process-based methods.