Methodology for the location of a subsurface permeable reactive barrier for the remediation of point source pollution on an Irish farm

Abstract

Nutrient loss from agricultural sources to water continues to be a national challenge. Diffuse pollution from agricultural sources is considered to be the primary cause of slight-to-moderate water pollution in Ireland, but agricultural point sources, such as farmyards, are often not considered due to their scattered spatial distribution and small areal extent. Agricultural point sources tend to be small and localised hot spots of nutrients and, therefore, can be efficiently treated using environmental technologies developed for wastewater and contaminated land treatment. A small area associated with soiled water irrigation, on a 4.27 ha case study site at Teagasc, Johnstown Environmental Research Centre, Ireland, was identified, where groundwater nitrate-nitrogen (NO3-N) concentration exceeds the maximum admissible drinking water concentration of 11.3 mg N L-1. A continuous, shallow permeable reactive barrier may be suitable to remediate point source pollution at this site. A methodology, based on site and groundwater characterisation, successfully located a site for a permeable reactive barrier.